The respiration of brain mitochondria and its regulation by monovalent cation transport.

The Na+ and K+ permeability properties of rat brain mitochondria were determined to explain the influences of these cations upon respiration. A new procedure for isolating exceptionally intact mitochondria with minimal contamination by synaptosomes was developed for this purpose. Respiration was uncoupled by Na+ and less so by K+. Uncoupling was maximal in the presence of EDTA plus Pi and was decreased by Mg2+. Maximal uncoupler-stimulated respiration rates were inhibited by Na+ but largely unaffected by K+. The inhibition by Na+ was relatively insensitive to Mg2+. Membrane Na+ and K+ conductances as well as neutral exchanges (Na+/H+ and K+/H+ antiport activities) were determined by swelling measurements and correlated with metabolic effects of the cations. Cation conductance, i.e. electrophoretic Na+ or K+ permeation, was increased by EDTA (Na+ greater than K+) and decreased by Mg2+. Magnesium preferentially suppressed Na+ conductance so as to reverse the cation selectivity (K+ greater than Na+). Neutral cation/H+ exchange rates (Na+ greater than K+) were not influenced by chelator or Mg2+. The extent of cation-dependent uncoupling of respiration correlated best with the inner membrane conductance of the ion according to an empirical relationship derived with the model K+ conductor valinomycin. The metabolic influences of Na+ and K+ can be explained in terms of coupled flow of these ions with protons and their effect upon the H+ electrochemical gradient although alternative possibilities are discussed. These in vitro studies are compared to previous observations in situ to assess their physiological significance.


Anaerobic hydrogenase activity in Anacystis nidulans. H2-dependent photoreduction and related reactions.

1. Anaerobic hydrogenase activity in whole cells and cell-free preparations of H2-induced Anacystis was studied both manometrically and spectrophotometrically in presence of physiological and artificial electron acceptors. 2. Up to 90% of the activity measured in crude extracts were recovered in the chlorophyll-containing membrane fraction after centrifugation (144 000 X g, 3 h). 3. Reduction of methyl viologen, diquat, ferredoxin, nitrite and NADP by the membranes was light dependent while oxidants of more positive redox potential were reduced also in the dark. 4. Evolution of H2 by the membranes was obtained with dithionite and with reduced methyl viologen; the reaction was stimulated by detergents. 5. Both uptake and evolution of H2 were sensitive to O2, CO, and thiolblocking agents. The H2-dependent reductions were inhibited also by the plastoquinone antagonist dibromothymoquinone, while the ferredoxin inhibitor disalicylidenepropanediamine affected the photoreduction of nitrite and NADP only. 3-(3,4-Dichlorophenyl)-1,1-dimethylurea did not inhibit any one of the H2-dependent reactions. 6. The results present evidence for a membrane-bound 'photoreduction' hydrogenase in H2-induced Anacystis. The enzyme apparently initiates a light-driven electron flow from H2 to various low-potential acceptors including endogenous ferredoxin.


Aerobic hydrogenase activity in Anacystis nidulans. The oxyhydrogen reaction.

1. The oxyhydrogen reaction of Anacystis nidulans was studied manometrically and polarographically in whole cells and in cell-free preparations; the activity was found to be associated with the particulate fraction. 2. Besides O2, the isolated membranes reduced artificial electron acceptors of positive redox potential; the reactions were unaffected by O2 levels less than 10--15%; aerobically the artificial acceptors were reduced simultaneously with O2. 3. H2-supported O2 uptake was inhibited by CO, KCN and 2-n-heptyl-8-hydroxyquinoline-N-oxide. Inhibition by CO was partly reversed by strong light. Uncouplers stimulated the oxyhydrogen reaction. 4. The kinetic properties of O2 uptake by isolated membranes were the same in presence of H2 and of other respiratory substrates. 5. Low rates of H2 evolution by the membrane preparations were found in presence of dithionite; methyl viologen stimulated the reaction. 6. The results indicate that under certain growth conditions Anacystis synthesizes a membrane-bound hydrogenase which appears to be involved in phosphorylative electron flow from H2 to O2 through the respiratory chain.


Two regimens of electrogenic cyclic redox chain operation in chromatophores of non-sulfur purple bacteria. A study using antimycin A.

Antimycin A causes a biphasic suppression of the light-induced membrane potential generation in Rhodospirillum rubrum and Rhodopseudomonas sphaeroides chromatophores incubated anerobically. The first phase is observed at low antibiotic concentrations and is apparently due to its action as a cyclic electron transfer inhibitor. The second phase is manifested at concentrations which are greater than 1--2 muM and is due to uncoupling that may be connected with an antibiotic-induced dissipation of the electrochemical H+ gradient across the chromatophore membrane. The inhibitory effect of antimycin added at low concentrations under aerobic conditions is removed by succinate to a large extent. It is expected that the electrogenic cyclic redox chain in the bacterial chromatophores incubed under conditions of continuous illumination may function at two regimes: (1) as a complete chain involving all the redox components, and (2) as a shortened chain involving only the P-870 photoreaction center, ubiquinone and cytochrome c2.


Short-lived delayed luminescence of photosynthetic organisms. I. Nanosecond afterglows in purple bacteria at low redox potentials.

A combined study of emissions of purple bacteria Rhodospirillum rubrum, Ectothiorhodospira shaposhnikovii and Thiocapsa roseopersicina was performed under conditions of low potential. It has been shown that a considerable part of the emission represents a delayed luminescence with a lifetime of about 5 ns and an activation energy delta E = 0.05 +/- 0.03 eV. Intensity of this delayed luminescence is approximately equal to that of prompt fluorescence. It diminishes as temperature decreases and also as the intermediate acceptor I becomes reduced after prolonged illumination under low potential conditions. This luminescence represents a radiative decay of the intermediate state, PF, and the luminescence activation energy, delta E, reflects the energy barrier between P*-890 and PF. The value of this barrier determined in the present work is much lower than those obtained previously [3,4,26] for the free-energy release during the primary act of charge separation, basing on redox potential techniques. The reason for this discrepancy is discussed. Delayed luminescence in the picosecond time range is predicted to exist under conditions of active photosynthesis as a result of a small (approx. 0.05 eV) energy barrier between PF and the excited singlet state of reaction center bacteriochlorophyll.


The ability of the mitochondrial Ca2+-binding glycoprotein to restore Ca2+ transport in glycoprotein-depleted rat liver mitochondria.

Rat liver mitochondria may be subfractionated in sediment and supernatant fractions by swelling in the presence of EDTA and oxaloacetate. The sediment is largely depleted of the Ca2+-binding glycoprotein and its Ca2+-transporting activity may be as low as 10--20% of the starting value. Both the rate of Ca2+ uptake and the capacity to maintain a high Ca2+ concentration gradient across the membrane are depressed. Addition of an osmotic supernatant to the assay mixture may partially restore the original Ca2+-transporting ability. The active component in the supernatant is the Ca2+-binding glycoprotein. This is shown by the following facts: (a) the effect is enhanced by the addition of the purified glycoprotein to the supernatant; (b) precipitation of the glycoprotein from the supernatant by affinity chromatography-purified antibodies abolishes the stimulatory effect, and (c) in the presence of 130 microM Mg2+, the glycoprotein alone may restore fully the Ca2+-transporting ability of the particles. The maximal velocity is already reached at 0.1 microgram glycoprotein/mg mitochondrial protein.


Studies on polyamine biosynthesis in Euglena gracilis.

Euglene gracilis (strain Z) was found to contain five polyamines which could be separated by high-pressure cation-exchange chromatography. 1,3-Diaminopropane, putrescine, norspermidine (N-(3-aminopropyl)-1,3-diaminopropane), spermidine and norspermine (N,N'-bis(aminopropyl)-1,3-diaminopropane) were identified. Biosynthesis of putrescine in E. gracilis proceeds through decarboxylation of L-ornithine, no arginine decarboxylase (EC 4.1.1.19) activity could be detected. The properties of the enzymes ornithine decarboxylase (EC 4.1.1.17) and S-adenosylmethionine decarboxylase (EC 4.1.1.50) in this alga were found to be similar to those of the enzymes isolated from animal tissues or yeast cells. A bioxynthetic scheme is proposed which relates the different polyamines occurring in E. gracilis.


The effects of platinum complexes on seven enzymes.

The effects of K2PtCl4, cis-Pt(NH3)2Cl2, and trans-Pt(NH3)2Cl2 on the activities of glyceraldehyde-3-phosphate dehydrogenase, glucose-6-phosphate dehydrogenase, dihydrofolate reductase, fructose-1,6-bisphosphate aldolase, catalase, tyrosinase, and peroxidase have been investigated. All of the enzymes which are thought to have essential sulfhydryl groups (glyceraldehyde-3-phosphate dehydrogenase, aldolase, and glucose-6-phosphate dehydrogenase) were significantly inhibited by K2PtCl4. The other four enzymes studied are not known to have essential sulfhydryl groups, and were not significantly affected by the Pt compounds under the conditions employed. Glyceraldehyde-3-phosphate dehydrogenase was the only enzyme inhibited by all three Pt compounds tested, with K2PtCl4 being the most effective and cis-Pt(NH3)2Cl2 the least effective inhibitor. Semilogarithmic plots of residual activity versus inhibition time indicated that the inhibition reactions were not simple first-order processes, except for the inhibition of glucose-6-phosphate dehydrogenase by K2PtCl4 which appeared to be first-order with respect to enzyme concentration.


Effect of growth rate on lipid and lipoteichoic acid composition in Streptococcus faecium.

The lipid composition of Streptococcus faecium (S. faecalis ATCC 9790) was analyzed at various growth rates. Diphosphatidylglycerol and the non-ionic lipid fraction containing diacylglycerols and neutral glycolipids appeared to accumulate relative to cellular mass as the culture mass doubling time increased from 30 to 80 min. Within the same range of doubling times the non-ionic lipid fraction appeared to become substantially enriched with diacylglycerols. All lipid species and cellular lipoteichoic acid accumulated relative to the cellular mass at doubling times exceeding 80 min, although diacylglycerol accumulation exceeded that of all other compounds studied.


Electrophoretic cell separation by means of microspheres.

The electrophoretic mobility of fixed human erythrocytes immunologically labeled with poly(vinylpyridine) or poly(glutaraldehyde) microspheres was reduced by approximately 40%. This observation was utilized in preparative scale electrophoretic separations of fixed human and turkey erythrocytes, the mobilities of which under normal physiological conditions do not differ sufficiently to allow their separation by continuous flow electrophoresis. We suggest that resolution in the electrophoretic separation of cell subpopulations, currently limited by finite and often overlapping mobility distributions, may be significantly enhanced by immunospecific labeling of target populations using microspheres.


The role of 5'-methylthioadenosine phosphorylase in 5'-methylthioadenosine-mediated inhibition of lymphocyte transformation.

To determine if increased 5'-methylthioadenosine phosphorylase activity in activated lymphocytes may be responsible for the decreased inhibitory effect noted when 5'-methylthioadenosine is added after stimulation, the activity of this enzyme was monitored during lymphocyte transformation. A direct correlation existed between the transformation process and 5'-methylthioadenosine phosphorylase activity; the longer the stimulation process progressed, the phosphorylase activity; the longer the stimulation process progressed, the greater the enzyme activity. The 7-deaza analog of 5'-methylthioadenosine, 5'-methylthiotubercidin, was utilized to explore further the role that the phosphorylase may play in the reversal process. 5'-Methylthiotubercidin acted as a potent inhibitor, but not a substrate, of the 5'-methylthioadenosine phosphorylase, and was an even more potent inhibitor of lymphocyte transformation than 5'-methylthioadenosine. However, in direct contrast to the 5'-methylthioadenosine effect, inhibition by 5'-methylthiotubercidin could not be completely reversed. These data suggest the 5'-methylthioadenosine phosphorylase plays an important role in reversing 5'-methylthioadenosine-mediated inhibition and that the potent, nonreversible inhibitory effects of 5'-methylthiotubercidin are due to its resistance to 5'-methylthioadenosine phosphorylase degradation.


A mathematical model of the optokinetic reflex.

The role of the optokinetic reflex (OKR) is that of cooperating with the vestibulo-ocular reflex (VOR) in the task of image stabilization on the retina during head rotations in a stationary visual surround. Since the dynamics of VOR was already well established, it has been possible to make a broad estimation of what the dynamics of OKR should be in order to obtain the performances observed in normal subjects. A mathematical model of OKR has been presented, and the experimental results obtained by Raphan et al. (1977) in the monkey and by Collins et al. (1970) in man were used to validate the model and to obtain a precise estimation of its parameters.


[Coordinate regulation of riboflavin permease and alpha-glucosidase synthesis in the yeast Pichia guilliermondii].

Riboflavin permease of the yeast Pichia guilliermondii appear to be inducible transport system. Its synthesis is induced by sucrose, maltose, alpha-methyl-D-glocoside, melizitose and raffinose, but not by D-glucose, trehalose or cellobiose. The synthesis of riboflavin permease in the presence of sucrose of maltose is depressed by cycloheximide, actinomycin D and 8-hydroxyquinoline. These results suggest that the synthesis of riboflavin permease is regulated on the transcription level. The inducers of riboflavin permease are also able to induce the synthesis of alpha-glucosidase. The mutants have been selected in which the synthesis of riboflavin permease occurs constitutively; the synthesis of alpha-glucosidase in the mutants is also constitutive. Growing of the yeast in a medium with high content of glucose results in a parallel decrease of the riboflavin permease and alpha -- glucosidase activities. These data are indicative of corrdinate regulation of riboflavin permease and alpha -- glucosidase in P. guilliermondii. Suboptimal or excessive content of vitamin B2 in the medium does not affect the level of riboflavin permease in this yeast species.


Inhibition of mammary carcinogenesis of dimethylbenzanthracene treated rats with a brominated triphenylethylene.

Daily administration of a brominated triphenylethylene (TBP), to rats which received 20 mg of DMBA p. o. inhibits mammary carcinogenesis. The effect appears even with very small doses (i ppm in the diet) and seems to be dose related. With one exception (an adenofibroma) the tumours in control and treated animals were malignant. Administration of TBP prevents the appearance of corporea lutea in the ovaries but not the usual necrosis of the adrenal cortex.


Altered arachidonate metabolism by platelets in patients with myeloproliferative disorders.

Platelet lipoxygenase and cyclo-oxygenase pathways were investigated by the incubation of 1(-14) C-arachidonic acid with washed platelets in 33 patients with myeloproliferative disorders, including 14 patients with chronic myeloid leukemia (CML), 12 with polycythemia vera (PV), 4 with essential thrombocythemia (ET), and 3 with myelofibrosis (MF). In patients with MF and CML, mean activities of the lipoxygenase pathway were significantly lower when compared with normal controls (p less than 0.001 and p less than 0.01, respectively). When a normal range of the activity was defined as mean +/- 2 SD, all patients with MF, 8 with CML, 6 with PV, and 1 with ET showed decreased lipoxygenase activities, while activities of the cyclo-oxygenase pathway were decreased in one of each patient with CML, PV, and ET. In 4 of 10 patients with a selective lipoxygenase deficiency, platelets were aggregated by lower concentrations of arachidonic acid than those necessary to induce normal platelet aggregation. It is suggested that the lipoxygenase activity could modulate platelet functions through its effect on arachidonate metabolism by the cyclo-oxygenase pathway and that a selective lipoxygenase deficiency could offer a mechanism for hyperfunction of the platelet, which may lead to a thrombotic tendency, one of the common features of myeloproliferative disorders.


Enzymes of the purine interconversion system in chronic lymphatic leukemia: decreased purine nucleoside phosphorylase and adenosine deaminase activity.

Activities of adenosine deaminase (ADA), adenosine kinase (AK), adenine phosphoribosyltransferase (APRT), hypoxanthine guanine phosphoribosyltransferase (HGPRT), and purine nucleoside phosphorylase (PNP), all enzymes of the purine interconversion system, were determined in lymphocytes of 25 patients with chronic lymphatic leukemia (CLL) and in 23 controls. A statistically significant decrease of PNP activities and a reduction of ADA activities at borderline levels were found in the patients, whereas for the other enzymes assayed no deviation from normal values was observed.


Vasoactive material present in the glomerula caudalia of the Vervet monkey.

Complex encapsulated neurovascular structures, glomus organs, occur in superficial and deep positions in many species. No direct evidence for their function exists. In skin they may serve thermoregulation by the reason for their structural complexity remains obscure. The concept of a local humoral circulatory control mechanism postulated on the basis of a very high acetylcholine content reported for human glomera coccygia has been investigated in homologous caudal glomus organs in monkey. No acetylcholine was detected. The organs contained 3-4 times the concentration of catecholamine (mainly noradrenaline) found in nearby vessels. Neither structure nor content of vasoactive component gives any support for an endocrine function.


Sexual disturbances in temporal lobe epilepsy:a controlled study.

Seventy cases each of temporal lobe epilepsy and grand mal epilepsy were studied for their sexual functioning. The two groups were similar as regards age, sex, duration of illness, frequency of seizures and menstrual and marital history. A significantly greater number of temporal lobe epileptics were found to be hyposexual. They had a global loss of performance and interest in the sexual sphere and showed no concern over it. One case in the group of temporal lobe eiplepsy, as against none in the other group, was hypersexual. There were no cases of sexual deviations in either of the groups. The findings of the study are discussed in the light of the relevant literature.


Fine needle catheter jejunostomy--an assessment of a new method of nutritional support after major gastrointestinal surgery.

The results of our experience with the technique of fine needle catheter jejunostomy and early postoperative feeding through the catheter over a 12-month period are presented. Of the 43 patiening with an elemental diet without complications, 3 (7 per cent) were not fed for different reasons and 13 (30 per cent) developed complications that led to temporary or permanent cessation of the feeding. One patient in this group died of inhalation pneumonia. The voluntary food intake of 12 of the patients who were fed by jejunostomy after major colorectal surgery was assessed daily for 2 weeks after operation and compared with that of 12 control patients who did not have nutritional support. No significant difference in voluntary food intake was found between the two groups. The changes in body composition and plasma proteins and the clinical outcome of 20 of the patients fed by jejunostomy after major colorectal surgery were also compared with those of 20 matched controls. Body weight and lean body mass (as assessed by total body potassium and arm muscle circumference) and plasma prealbumin fell significantly in the control patients but not in those fed by jejunostomy. However, plasma transferrin decreased in both groups and there was no significant difference in clinical outcome in terms of complication rate or duration of postoperative hospital stay. The study would suggest that this technique of jejunostomy feeding should be reserved for selected cases where it may prove to be of real value, rather than being used routinely.


Multi-element analysis of the living body by neutron activation analysis-application to critically ill patients receiving intravenous nutrition.

Neutron activation analysis has been used to determine the total content in the body of N, K, Na, Cl, P and Ca in 25 critically ill surgical patients before and after a 14-day course of intravenous nutrition. Muscle elemental composition was also determined in these patients at the same time as the total body analysis. Over the 14-day period of intravenous feeding the total body contents of all the measured elements increased (2-9.7 per cent) but only the increase in K was statistically significant. Muscle chemistry suggested an intracellular K depletion which was corrected over the study period. The results of the total body multi-element analysis were interpreted to show a mean gain of 1.25 l of extracellular fluid and 0.51 l of intracellular fluid and direct measurement of total body water suggested that this interpretation was probably valid. The first application of the technique to patients with nutritional and metabolic problems has quantified the weight gained by two body compartments during a 2-week period of intravenous nutrition. Its further application should help to solve a number of nutritional and metabolic problems in clinical surgery.


Failure of iron to promote attachment of gonococci to human spermatozoa under physiological conditions.

The effect of iron on the attachment of gonococci to human spermatozoa was investigated using the three iron salts, ferric chloride, ferric nitrate, and ammonium ferric citrate (AFC). Ferric chloride and ferric nitrate were found to be unsuitable for such studies because they were insoluble at physiological pH values, produced a marked decrease in the pH of unbuffered medium (Ringer's solution), and agglutinated spermatozoa. AFC, in contrast, was soluble at physiological pH, did not affect the pH value of Ringer's solution, and did not agglunate spermatozoa. When gonococci and spermatozoa were mixed together in media with and without AFC, the proportion of spermatozoa with adherent gonococci was approximately the same in each case. Thus, in contrast to previous report, we have found that the addition of iron does not increase the attachment of gonococci to human spermatozoa.


Frequency of simultaneous carriage of Neisseria gonorrhoeae and Neisseria meningitidis.

Gonococci were found by culture in 112 of 442 patients suspected of having gonorrhoea. Meningococci were cultured from the pharynx more than twice as often in patients harbouring gonococci (26%) than in patients from whom gonococci could not be cultured (11%). These results could indicate an individual susceptibility to Neisseria organisms or they could be caused by a difference in the behaviour of patients with and without gonorrhoea, the conduct of the former making them not only more likely to be infected with Neisseria gonorrhoeae but possibly more exposed to Neisseria meningitidis as well.


Meningococcal colonisation misdiagnosed as gonococcal pharyngeal infection.

Three cases of pharyngeal gonorrhoea were misdiagnosed in patients harbouring meningococci which failed to utilise maltose in CTA medium. The microbiological identity of the isolates was established by other means. Although meningococci giving atypical reactions to carbohydrate utilisation tests occur only rarely, the possibility of a misdiagnosis of gonorrhea, and its social and legal repercussions, should be considered.


Single-dose minocycline in the treatment of gonococcal urethritis. Clinical efficacy in relation to bacterial resistance and its effects on associated Chlamydia trachomatis infections.

Seventy-two men with gonococcal urethritis were given a single 300-mg dose of minocycline. The failure rate was 13% and the trial was terminated at an early stage. Failure was correlated with increased resistance of Neisseria gonorrhoeae to minocycline. The activity of penicillin, spectinomycin, erythromycin, tetracycline, sulphamethoxazole, cefuroxime, cefotaxime, rosamicin, thiamphenicol, and piperacillin against N. gonorrhoeae were examined in vitro. With the exception of spectinomycin, parallel patterns of resistance to the other antibiotics and minocycline were found. Resistance to spectinomycin was not found, confirming the usefulness of this antibiotic in the treatment of gonorrhoea. The incidence of PGU was significantly lower after a single dose of minocycline than in previous studies.


Staphylococcus saprophyticus in the aetiology of nongonococcal urethritis.

The occurrence of Staphylococcus saprophyticus, Chlamydia trachomatis, and Neisseria gonorrhoeae in urethral specimens of 252 men attending a venereal disease clinic was studied. When using a selective broth medium containing novobiocin and nalidixic acid, Staph. saprophyticus was isolated from 20.8% of 178 men with symptoms of urethritis and from 14.9% of 74 men without such symptoms. Staph. saprophyticus was found significantly less often in controls (7.1% of 56) than in the men with symptoms of urethritis. In the 35 men from whom Staph. saprophyticus was recovered more than 10 leucocytes per high power field in urethral smears occurred more often than in those from whom this organism, or either of the other two agents, were not isolated. No differences were found in the symptoms reported by the men harbouring Staph. saprophyticus or C. trachomatis or those with negative cultures. The results of the present study tend to suggest that Staph. saprophyticus is the aetiological agent of some cases of nongonococcal urethritis.


Mapping of local cerebral functional activity by measurement of local cerebral glucose utilization with [14C]deoxyglucose.

A method has been developed to measure the rates of glucose utilization in the individual structural and functional components of the central nervous system. It can be applied to conscious as well as anaesthetized animals. The method is based on the use of [14C]deoxyglucose as a tracer for glucose consumption. [14C]Deoxyglucose-6-phosphate accumulates in the tissue in a mathematically definable relationship to the rate of the tissue's glucose utilization. The [14C]deoxyglucose-6-phosphate concentrations in the various tissues of the nervous system are measured by a quantitative autoradiographic technique. The autoradiographs themselves are pictorial representations of the relative rates of glucose consumption in these tissues. Application of this method to rats and monkeys in various states of altered function demonstrates a clear and close relationship between the local levels of functional activity and energy metabolism. The method appears to be useful for mapping functional neural pathways on the basis of evoked metabolic responses (Plum, Gjedde and Samson, 1976).


Memory disorder in Korsakoff's psychosis: a neuropathological and neuropsychological investigation of two cases.

Neuropathological findings in the brains of two alcoholic patients with Korsakoff's psychosis are reported. Their memory defects had been studied in detail quantitatively over a period of nine years in one case and three years in the other, relevant details of which are presented. Both patients had had a relatively pure long-term memory impairment in the absence of other cognitive deficits and in the absence of a short-term memory impairment. Their retrograde amnesia for public events and famous faces had been measured and found to have extended backwards over at least twenty-five years. There was severe impairment in anterograde recognition memory for both verbal and non-verbal material. On a newly prepared memory quotient battery both patients had scored well below the bottom of the normal scale (less than 60, where 100 is the mean with a standard deviation of +/- 15). Both patients had also shown the characteristic differential improvement in retention when tested by cued recall and also the characteristic 'prior learning effect', i.e. normal retention of one list of words when tested by cued recall but impaired retention of a second list sharing the same cues as the first list. There had been a slight but significant deterioration in intelligence in one of the patients in the two years prior to his death, although his IQ still fell within the normal range. The other patient remained undeteriorated until his death, and his IQ also was close to an estimated measure of his premorbid IQ. In the brains of both patients there was marked gliosis, shrinkage and discolouration bilaterally in the medial nuclei of the mammillary bodies. In addition there was a thin band of gliosis bilaterally between the wall of the third ventricle and the medial dorsal nucleus, the rostral limit lying anterior to the medial dorsal nucleus. In the patient with no intellectual deterioration these were the only pathological changes that were seen. In neither patient was there evident local loss of nerve cells, gliosis or any other qualitative evidence of abnormality in the hippocampi, the white matter of the temporal lobes or the greater part of the medial dorsal nuclei, although it is difficult to be certain whether there was any overlap between the band of gliosis and the most medial region of the medial dorsal nueleus and other adjacent thalamic nuclei. In the other patient there was also a small zone of softening in the cerebellum and an increase in astrocytes in other regions of the cerebral hemispheres, including the basal ganglia, amygdala, and brain-stem, but without noticeable loss of cells. The question of the minimal lesion for the alcoholic Korsakoff amnesic state, and some aspects of the related anatomy, is discussed in the context of other reports in the literature which are, however, difficult to assess in the absence of details of the specificity, severity and character of the memory disorders.


Plasticity in speech organization following commissurotomy.

For three-and-a-half years we have been studying the cognitive and conscious mechanisms in a remarkable 18-year-old man: Case P.S. This unique individual had his corpus callosum divided in order to control intractable epilepsy. Although for some time after the operation he appeared like other split-brain patients, unable to describe verbally stimuli directed to his mute right hemisphere, he behaved as if he was capable of comprehending a wide range of language-related stimuli directed to that hemisphere. Spelling by choosing the appropriate letters with his left hand, he could process nouns, verbs, rhymes, antonyms, and superordinate concepts. When asked about tachistoscopic presentations delivered to his left visual field, he either said he had seen nothing, or only a flash of light. He was also unable to identify verbally tactile 'sterognostic' inputs to his left hand. In the last year P.S. has begun to speak about stimuli directed to his right hemisphere. This series of experiments suggests that this speech is not interhemispheric transfer within the visual modality. Further, plotting the relative increased proficiency of verbal description of inputs directed to the right hemisphere, this speech system seems to be in a process of continuing development.


Visual areas in the temporal cortex of the macaque.

Visual receptive fields and responsiveness of neurons to somesthetic and auditory stimuli were studied in the inferior temporal cortex and adjacent regions of immobilized macaques. Neurons throughout cytoarchitectonic area TE were responsive only to visual stimuli and had large receptive fields that almost always included the center of gaze and usually extended into both visual half-fields. There was no indication of any visuotopic organization within area TE. Neurons in an anterior and in a dorsal portion of TE tended to have larger receptive fields. By contrast, dorsal, ventral and anterior to area TE, units often responded to somesthetic and auditory as well as to visual stimuli. In these regions visual receptive fields were even larger than in TE and often included the entire visual field. Posterior to TE the neurons were exclusively visual and had much smaller receptive fields that were confined to the contralateral visual field and were topographically organized.


Effects of interruption of the nigrostriatal pathway and of dopaminergic agents on the spontaneous activity of globus pallidus neurons in the awake monkey.

Interruption of the nigrostriatal pathway has been shown to change parameters of striatal activity. These changes are often difficult to explain because the functional structure of the striatum is not understood sufficiently. The function of the globus pallidus appears to be simpler. It transmits the output of the striatum to the thalamus and to the midbrain. Yet the effects of interruption of the nigrostriatal pathway on the activity of pallidal neurons are unknown. To study these effects the spontaneous activity of globus pallidus neurons was recorded in intact monkeys and in monkeys with lesions of the ventromedial midbrain tegmentum. The two groups of animals were studied with and without administration of dopaminergic agents. In intact monkeys medial pallidal neurons discharge uninterruptedly at high firing rates, while the discharge of most lateral pallidal neurons is interrupted by relatively long periods of silence. Lesions involving the nigrostriatal pathway change the firing patterns but not the mean firing rates of pallidal neurons. In lesioned monkeys pallidal neurons fire in bursts continuously: during movement, rest and sleepiness. Two lines of evidence strongly suggest that the bursting pallidal activities are a consequence of the interruption of the nigrostriatal dopaminergic pathway: (1) the percentage of bursting pallidal neurons is proportional to the amount of degeneration in the pars compacta of the ipsilateral substantia nigra; (2) chronic administration of dopamine antagonists, haloperidol and reserpine, reproduces in intact monkeys the bursting activities observed in lesioned animals. On the other hand, single injections of dopamine agonists, apomorphine and piribedil, silence the medial pallidum and concomittantly abolish the signs of parkinsonism displayed by lesioned monkeys.


Laminar origins and terminations of cortical connections of the occipital lobe in the rhesus monkey.

Cortical connections within the occipital lobe (areas 17, 18 and 19) of the rhesus monkey are investigated with the autoradiographic and horseradish peroxidase procedures. Two efferent systems, each with a specific laminar organization, are observed. (1) Rostrally directed connections, from area 17 to 18, area 18 to 19 and area 19 to the inferotemporal region (area TE), originate from neurons in layer IIIc (and, in area 19, from a small complement of neurons in layer Va), and terminate in and around layer IV. (2) In contrast, connections in the reverse direction ('caudally directed' connections), from area TE to 19, area 19 to 18, and area 18 to 17, originate from neurons in layers Vb, VI and, to a lesser extent, IIIa, and terminate mainly in layer I. In addition, the laminar organization of several intrinsic and callosal connections are observed. In trinsic connections within areas 18 and 19 originate from neurons in layers IIIc and, to a lesser extent, Va, and terminate in vertical bands in layers I to IV. Callosal connections from areas 18, 19, and the caudal inferotemporal region originate from neurons mainly in layer IIIc. From areas 18 and 19, these callosal connections terminate in vertical bands in layers I through IV. Thus, different cortical projection systems are characterized by specific laminar distributions of efferent terminations as well as of their neurons of origin.


Use of a spectrophotometer for radiographic photodensitometry of bone.

A conventional spectrophotometer was used to do radiographic photodensitometry of bone mass. An experiment to produce osteoporosis in guinea pigs required quantification of changes in bone mass. Lack of a densitometer necessitated finding another method for quantification. The method developed involved using industrial film in a closed X-ray system. Optical density of X-rays was then read in a spectrophotometer at nine femur locations. Highly significant correlations between optical density and femur calcium content and femur dry weight per millimeter were obtained. Histological sections from an animal with low optical density measurements confirmed bone loss by showing decreased cortical width and loss of trabecular bone. In addition to using readily available equipment, this method offers the advantage of being able to detect bone loss in specific areas of the bones. In addition, bones are left intact and can be used for other purposes.


Precipitation of calcium phosphates from electrolyte solutions. V. The influence of citrate ions.

The influence of citrate ions on the precipitation of crystalline apatitic precipitates with low Ca/P molar ratios [octacalcium phosphate (OCP) and calcium-deficient apatites (DA) (system A)] and of the intercrystalline mixtures of calcium hydrogen phosphate dihydrate (DCPD) and DA (system B) was investigated. Samples were prepared by direct mixing of calcium chloride solutions (A, 6.10(-3) mol dm-3; B, 1.10(-1) mol dm-3) and sodium phosphate solutions (A, 6.10(-3) mol dm-3; B, 2.10(-2) mol dm-3) containing citrate (0-2.10(-3) mol dm-3) and preadjusted to pH 7.4. In the presence of citrate ions: (a) crystal growth of OCP and DA was slowed down; (b) habit modification of DCPD crystals occurred; and (c) equilibration in intercrystalline mixtures of DCPD and DA's was slowed down. All phenomena were caused by surface adsorption of negatively charged ions, most probably CaC6H5O7-, which is the prevalent calcium citrate species under the given experimental conditions. Habit modification of DCPD was induced by preferential adsorption at the (001) crystal plane.


Giant cell carcinoma of the liver: occurrence in a patient with ileal carcinoid, medullary breast carcinoma and pulmonary aspergillosis.

Pure giant cell carcinoma of the liver is a rare tumor that is usually associated with cirrhosis. Its occurrence in a young woman without evidence of cirrhosis, and in association with two other uncommon tumors, is described in this report.


Rabbit cranial sutures in vitro: a new experimental model for studying the response of fibrous joints to mechanical stress.

An organ culture system has been developed whereby mechanical stress can be applied to cranial sutures under controlled experimental conditions. The application of a continuous tensile mechanical stress (30 g) to cranial sutures from newborn rabbits (1--2 days) was accompanied by a significant increase in the incorporation of 3H-leucine and 3H-proline into suture protein. The specific activities of 3H-hydroxyproline indicated that mechanical stress produced a two-fold increase in the incorporation of 3H-proline into collagen. However, the proportion of the total radioactivity recoverable in collagen (45.63 +/- 2.33% for nonstressed; 40.58 +/- 2.17% for stressed sutures) was not significantly different. These data suggest that the increase in collagen synthesis occurs as part of a general stimulation of protein synthesis, and do not support the view that mechanical stress is the principal mechanism regulating the turnover of collagen in fibrous joints. These initial studies demonstrate that an in vitro experimental model has considerable potential for investigating the morphological and metabolic response of fibrous joints to mechanical deformation.


Bone morphology in epileptics.

In 31 epileptics, most of whom had been on anticonvulsive drugs for decades, the amount of osteoid--active and inactive--and the osteoclast activity were measured in iliac crest biopsies and compared with the same variables from a control group. Although falling within normal limits, the amount of osteoid, in particular the inactive osteoid, was significantly increased in the epileptics. The osteoclast activity was also significantly increased in the epileptics.


Bone mineral content in epileptics.

The bone mineral content in the forearms was measured in 71 epileptics, admitted to an institution for epileptics. The mineral content was decreased in epileptics as compared with age-matched normal controls. The decrease was in the order of 10--15% except in the distal end of the forearm in women. Also, the strength of the hand and forearm was decreased by 1/3 and since there is a known relationship between strength and bone mineral content, the loss of bone mineral may be secondary to the loss of strength. Therefore, inactivity could be an important contributory factor to the bone mineral loss in these epileptics.


Differences in intracortical bone remodeling in three aboriginal American populations: possible dietary factors.

Cross sections of intracortical bone revealed differences among three early American populations--Eskimo, Arikara, and Pueblo--in the frequency of a form of remodeling called, here, type II. This remodeling appears to occur exclusively within the walls of haversian canals of well-mineralized osteons. The populations are known to have differed in their nutrition. The Eskimo, with a high-protein diet, exhibited the most frequent type II remodeling, whereas the Pueblo, with a low-protein diet, showed the least. Type II remodeling probably reflects the physiological state of the group. Variation in frequency of classic intracortical bone remodeling was not apparent.


Composition of apatites in human urinary calculi.

Calcium-deficient carbonate apatites in urinary calculi from 17 patients have been studied. Magnesium ions in each case were detected as a component of apatite. In most of the cases, CO23- ions were included in the apatitic lattice. Using a calcination procedure, we have determined the most probable average value for the CO23- content, degree of deficiency, x, and the Mg/Ca ratio in each sample.


EDTA soluble protein of human mature normal enamel.

Pure human mature enamel was prepared using a careful microdissection technique. After EDTA dissolution, the soluble proteins were recovered representing a concentration of 0.035% in the initial enamel. When the samples were analyzed with polyacrylamide gel electrophoresis, Coomassie Brilliant Blue staining revealed only one sharp fast migrating band, whereas o-toluidine blue, methylene blue, Amido Black 10B, and pyronine red G showed a thin double band at the same migration distance. Ultracentrifugation studies suggested that the proteins were of low molecular weight or of weak density. Absorption spectra showed a strong absorbance at 260 nm. After hydrolysis, amino acid analyses yielded a composition of 25% Gly, 13.5% Glu, 11% Ser, and 11% Pro. Cysteine measured as cysteic acid was present at 2%, and 2% hydroxyproline was found. A carbohydrate content of 15% was estimated by the anthrone method. Glucose, galactose, mannose, and fucose, identified through gas chromatography, were in a molar ratio of 9:4:3:1. Thus the organic matrix of adult human enamel consists of one or possibly two acidic glycoproteins.


Acute effects of Solanum malacoxylon on bone formation rates in growing rats.

The plant Solanum malacoxylon is responsible for a syndrome of hypercalcemia, soft tissue mineralization, and progressive wasting in South American cattle known as enteque seco or espichamento. There is evidence that a glycoside of 1,25-dihydroxycholecalciferol is the active principle in the plant. The basis for the hyperostosis seen in the disease is unclear. To study the acute effects on bone formation rates, 8-week-old rats were given an aqueous extract equivalent to 250 or 1000 mg of Solanum daily per os for 7 days. Bones were labeled by injection of fluochrome 2 days before the start of treatment and 2 days prior to sacrifice. Morphometric evaluation of undecalcified sections of caudal vertebrae revealed an increased amount of trabecular bone in both Solanum treated groups with no difference due to dose level. This was associated with an increase in the bone apposition rate on trabecular surfaces. No differences were found in the amount of osteoid seam width. Periosteal apposition rate and endochondral bone formation were also measured and no significant differences found. The findings indicate that acute stimulation of cell level bone formation on trabecular surfaces may play a role in the hyperostosis seen in the naturally occurring condition.


Detection of collagen degradation products from subcutaneously implanted organic bone matrix.

Demineralized bovine bone powder was reduced with NaB3H4 to label the collagen crosslinks with tritium. The powder was enclosed in small nylon mesh pouches and implanted subcutaneously into rats for 3 weeks. Histological examinations revealed that multinuclear giant cells accumulated around the bone matrix, some in Howship's lacunae. Collagenous peptides containing intermolecular crosslinks were detected in the urea-soluble fraction extracted from the implant. Two crosslink-containing peptides were isolated from a dialyzable fraction: one contained dihydroxylysinonorleucine and the other hydroxylysinonorleucine. Both peptides had molecular weights of approximately 1000 estimated from the elution positions of gel filtration chromatography; and both had similar quantitative compositions of amino acids. There were no homologous peptides detected in a control experiment of the reduced bone matrix which was incubated in vitro with buffered saline for 1 week at 37 degrees C.


Influence of magnesium depletion on matrix-induced endochondral bone formation.

The effect of magnesium deficiency on bone cell differentiation and bone formation was investigated using in vivo matrix-induced endochondral ossification as a test system. Demineralized bone matrix was implanted subcutaneously in young (35-day-old) male Long-Evans rats that had been fed a semisynthetic Mg-deficient diet (50 ppm Mg) for 7 days. Plasma Mg levels were reduced to 25-30% of control values at that time. Control rats were paired the same diet, supplemented to contain 1000 ppm Mg. The implants were harvested 7, 9, 11, 15, and 20 days after implantation and analyzed for Mg and Ca content, 45Ca incorporation, and alkaline phosphatase levels. At each stage, plaques (implants) removed from Mg-deficient rats showed retardation in cartilage and bone differentiation and matrix calcification. Magnesium content was markedly reduced when compared to the control plaques. Histological appearance of the matrix-induced plaques confirmed the retardation in bone development and mineralization suggested by the chemical indicators. Most marked was the virtual absence of bone marrow in 20-day-old plaques in Mg-depleted rats. These data show that bone cell differentiation can occur in a severely Mg-depleted environment, although the onset of mineralization and bone remodeling was delayed and bone marrow differentiation was impaired.


Bone mineralization and metabolism of 3H-25-hydroxyvitamin D3 in thyroparathyroidectomized rats treated with parathyroid extract.

Thyroparathyroidectomized rats fed a diet containing 1.2% calcium, 0.55% phosphorus maintain normal serum levels of these ions. Treatment of such rats with parathyroid extract (PTE; 20 U/100 g twice daily; 10 days) has no statistically significant effect on rates of bone formation, matrix apposition, or osteoid maturation. Significant decreases in osteoid width and mineralizing front width, as well as a 60% increase in the rate of initial mineralization were observed in the PTE-treated group. Conversion of 3H-25-hydroxyvitamin D3 to 3H-1,25-dihydroxyvitamin D3 was 4-fold higher in the PTE-treated group than in the untreated animals. Increased formation of 1,25-dihydroxyvitamin D3 in response to treatment with PTE may play a major role in correcting the mineralizing defect resulting from thyroparathyroidectomy.


Enzymatic properties of the Ca2+-binding glycoprotein isolated from preosseous cartilage.

The Ca2+-binding glycoprotein isolated from preosseous cartilage shows also alkaline phosphatase activity. The purification procedure indicates that the enzyme is inhibited in crude extract and conceivably in the intact tissue; the activity may be controlled by the proteoglycans present in the matrix. Other substrates are hydrolyzed by the purified enzyme in addition to p-nitrophenylphosphate; the highest specific activity was measured with ATP and pyrophosphate (PPi) at pH 7.5 and 9.0 Mg2+ induces an activation of ATP and PPi hydrolysis; Ca2+ activates hydrolysis of ATP but inhibits that of PPi. The glycoprotein shows also transphosphorylase activity, L-serine being the best phosphate acceptor. The release or transfer of Pi catalyzed by the glycoprotein can be an important step in calcium phosphate precipitation.


Incorporation of serum albumin into the developing dentine and enamel matrix in the rabbit incisor.

Rabbit serum albumin labeled with 125I was injected into rabbits (650-870 g). The incorporation pattern of the labeled albumin into the developing dentine and enamel matrix was studied 1 h, 6 h, and 3 days after the injection using autoradiography. Silver grains were observed over the predentine 1 h after the injection. They were found over the dentine matrix adjacent to the predentine-dentine junction at 6 h. The silver grain band was concentrated over the internal dentine matrix at 3 days. However, no appreciable amount of the silver grains could be seen over the enamel matrix at any time after the injection. It is possible that there might be some physiological barrier between the extravascular fluid and the enamel matrix. The role of the albumin in dentine is discussed.


Enamel structure in some therapsids and mesozoic mammals.

The distribution of enamel tubules, the shapes and arrangements of prisms, and the orientation of crystals in ground sections from several therapsids and mesozoic mammals have been investigated by conventional and polarizing microscopy. Along each of three separate phylogenetic lines which evolved occluding teeth, there was a progressive increase in the numbers of enamel tubules. In the investigation, the arcade-shaped prisms typical of recent mammals were first seen in material from the Cretaceous period. All the enamels investigated from the Triassic contained columns of crystals, which were deduced as hexagonal. The inner ends of the crystals within each column deviated towards the center of the column. It is concluded that the existence of an interprismatic region provides the most important distinction between prismatic enamels and the hexagonal columns of crystals in the Triassic material.


Vaterite, a constituent of the eggshells of the nonparasitic cuckoos, Guira guira and Crotophagi ani.

The crystalline spherules occurring in patches on the outer surface of the eggshells of Guira guira and the bloom on the entire outer surface of those of Crotophagi ani were shown by X-ray diffraction analysis to be vaterite.


A bone-fixing trephine for large-diameter iliac biopsies in dogs.

For experimental studies of bone in dogs it may be necessary to collect from the iliac crest biopsies of a larger diameter than is usually obtainable. A disadvantage of using a trephine with a large bore is that the biopsy may be pulled out of the trephine by the forces exerted by tendons inserted in the medial cortex of the ilium. To overcome this difficulty we developed a trephine with an internal bore of 10 mm combined with a biopsy-fixing attachment.


Potassium, sodium, and the intracellular fluid space of cells from bone.

Cells enzymatically dispersed from fetal rat calvaria were analyzed for sodium and potassium content and intracellular fluid space (ICF). Even when obtained in comparatively high yield, the cells are damaged by the isolation procedure as evidenced by high sodium and low potassium content immediately after isolation. During a post-incubation period potassium is accumulated and sodium extruded to steady-state levels. Although electrolyte content of cells after recovery did not vary as a function of cell yield, ICF was increased in cells obtained in lower yield, suggesting cell swelling as a result of membrane damage. The weighted mean values obtained for the best cell preparations were 117 mM K+ and 27 mM Na+. Based on DNA assay of isolated cells and the whole tissue, 20- to 21-day calvaria were found to have an average of 8.1 x 10(6) cells/calvarium. Combining cell data with analysis of total tissue sodium, potassium, and water, it was concluded that the tissue extracellular sodium is in equilibrium with blood but that the potassium concentraiton is approximately 5-fold higher than blood levels.


Lattice parameters and cation distribution of solid solutions of calcium and strontium hydroxyapatite.

Solid solutions of strontium and calcium hydroxyapatite were synthesized by solid-state reaction. Lattice parameters of these compounds were determined using two types of Guinier cameras. They vary linearly with the molar percentage of strontium hydroxyapatite. The distribution of Ca and Sr ions over the fourfold and sixfold positions in the apatite structure was determined by comparing experimental and calculated values for the intensity ratios of suitable reflections. A slight, although significant, preference of Sr for the sixfold position was found. An ideal behavior is predicted for these solid solutions.


Experimental alveolar bone loss in the monkey evaluated by 125I absorptiometry.

An 125I absorptiometry technique is described which has sufficient precision to detect the alveolar bone loss associated with ligature-related periodontitis in the monkey. Six monkeys had significant drops in alveolar bone mass 14 days after the the application of a silk ligature around the gingival margin of an adjacent tooth. Variation in the magnitude of bone loss was observed. These may represent variations in the pathogenicity of the microflora produced in response to a ligature and/or variation in host response to the insult produced by specific dental plaque organisms. The lack of bone loss post-ligature plus antibiotic therapy supports the theory that the bacterial-host interaction, not simply irritation from the ligature alone, is responsible for the bone loss. The potential for bone regeneration after ligature-induced bone loss is demonstrated.


Regulation of intestinal calcium-binding protein in rats: role of parathyroid hormone.

Intestinal calcium-binding protein (CaBP) levels of rats fed a high (1.5%) Ca diet were the same whether the animals were parathyroidectomized (PTX), sham-operated controls pair-fed with the PTX animals, or sham-operated controls fed ad libitum. Consequently, a given base level of CaBP seems to be parathyroid hormone independent and not closely related to feed intake. On the other hand, whereas the ad libitum fed controls more than doubled their intestinal CaBP in response to a 2-day low-calcium (0.02%) regimen, neither the parathyroidectomized animals nor the pair-fed sham-operated controls were able to do so. Since the latter two groups consumed less feed and therefore less vitamin D than the ad libitum fed animals, the inability to increase CaBP in response to a low-calcium diet may have been caused by a restricted vitamin D intake rather than by the absence of parathyroid hormone.


Regulation of calcium transport in isolated periosteal cells, effects of hormones and metabolic inhibitors.

Calcium transport was studied in cells isolated from cultured periostea of 18-day-old chick embryos. Net calcium uptake was stimulated by iodoacetate (IAA) and inhibited by dinitrophenol (DNP). Calcium efflux from the intracellular compartment was inhibited by IAA. Changes in the extra- or intracellular sodium concentration had only minor effects on calcium transport. This indicates that calcium efflux from periosteal cells is probably directly dependent on ATP hydrolysis, whereas calcium-sodium exchange is of less importance. The cation ionophore A23187 stimulated calcium uptake during short incubations but was inhibitory in long incubations. The possible involvement of the mitochondria in this effect is discussed. Parathyroid hormone (PTH) and calcitonin (CT) stimulated the net uptake of calcium in relatively low doses (both 0.01 U/ml or higher). The effects of the hormones on net calcium uptake were not additive. Calcium efflux was not changed in the presence of PTH or CT.


Aspartic acid-rich proteins: major components of the soluble organic matrix of mollusk shells.

DEAE-cellulose ion-exchange chromatography separates soluble organic matrix components of three mollusk shells, each from a different taxonomic class, into analogous subfractions. The proteins of all subfractions are enriched in acidic and polar amino acids. In each chromatogram, however, the subfraction which contains the major portion of total protein also contains the highest concentration of aspartic acid. Thus the major components of the soluble organic matrix are aspartic acid-rich proteins. The identification of these proteins in mollusks, together with the known occurrence of aspartic acid and phosphoserine-rich proteins in vertebrate tooth dentin, emphasizes the fundamental importance of such acidic proteins in the processes of mineralization.


The occurrence of chondroitin-6-sulphate in adult human compact bone tissue.

Compact bone tissue chondroitin sulphate, previously considered to be pure chondroitin-4-sulphate, was isolated from three adult human femoral diaphyses and digested with chondroitinase ABC. Assaying these digests by means of high performance liquid chromatography we could demonstrate that 12 to 14% of the disaccharide residues were 6-sulphated. The 4/6-ratios were also studied in chondroitin sulphate fractions of different molecular size. Slightly increasing amounts of 6-sulphated disaccharides were found with increasing size of the chondroitin sulphates.


Infrared absorption bands from NCO- and NCN2- in heated carbonate-containing apatites prepared in the presence of NH4+ ions.

Infrared bands at about 2200 and 2010 cm-1 in the spectra of heated synthetic and biological CO3Aps are assigned to cyanate and cyanamide ions respectively. The formation of these ions is associated with the presence of nitrogenous species in the unheated materials.


Change in response with age of human articular cartilage to plasma somatomedin activity.

Normal male articular cartilage (34 specimens, age range 1--30 years) has been examined in vitro for response to somatomedin (SM) activity. Basal 3H-thymidine and 35S-sulfate incorporation both decreased with increasing age of the cartilage donor. However, enhancement of isotope incorporation which was attained on addition of 10% normal plasma (containing IU SM/ml) was greatest in cartilage from adolescents in the age range 12--17 years. The mean enhancement of 3H-thymidine incorporation (expressed as % basal) was as follows: age 1--10 years = 184 +/- 28 (SE), N = 9; 12--17 years = 436 +/- 101 (11); 18--30 years = 231 +/- 49 (8); and for 35S-sulfate incorporation was 1--10 years = 389 +/- 100 (8); 12--17 years = 824 +/- 273 (11); and 18--30 years = 572 +/- 56 (8). The increased response of cartilage in the 12--17 year group suggests that a greater sensitivity to the somatomedins may contribute to the increased skeletal growth during adolesence.


Therapeutic implications of patterns of recurrence in cancer of the uterine cervix.

Five hundred twenty-six patients with invasive cervical cancer, treated at the University of Kentucky from 1964 to 1976, were followed 2--12 years after therapy. One hundred and sixty patients (31%) developed tumor recurrence. Recurrent cancer was noted with 1 year after therapy in 58% of patients and within 2 years of treatment in 76% of patients. Only 6% of patients with recurrent cervical cancer survived 3 or more years. Stage of disease, cell type, lesion size, and the presence of lymph vascular space invasion by tumor cells were all shown to be prognostically significant. The addition of extrafascial hysterectomy to radiation therapy significantly decreased the incidence of recurrence in stage IB cervical tumors 5 cm or more in diameter. Analysis of this data suggests that radical hysterectomy and pelvic lymphadenectomy is as effective as irradiation only in the treatment of large cell squamous carcinomas 2 cm or less in diameter.


Sialic acid metabolism in rats undergoing chemically-induced mammary gland carcinogenesis in specific dietary states.

The enzymes responsible for the activation, transfer and hydrolysis of sialic acids were investigated in female rats with mammary adenocarcinomas induced by administration of a single oral dose (10 mg) of 7,12-dimethylbenz[alpha]anthracene. The carcinogenic process was modulated by the levels and degree of unsaturation of the dietary lipids. Tumor incidence was highest in rats fed a diet containing 20% corn oil, intermediate with 18% coconut oil plus 2% linoleic acid, and lowest in the group receiving a diet with 2% linoleic acid. Sialyltransferase and CMP-N-acetylneuraminic acid synthetase activities were higher in tumors than in control mammary glands. Neuraminidase activity, on the other hand, was higher in control tissue than in tumors. In addition to these tumor-related effects, comparison of the enzyme levels in mammary tissues from control animals of the 3 dietary groups revealed the presence of diet-related effects on sialic acid metabolism. In the livers of tumor-bearing rats, only minor changes of enzyme activities were detected.


Reduction in the formation of carcinogen-induced transformed foci by pencillin G sodium in the C3H/10T1/2 CL8 cell lines.

The C3H/10T1/2 CL8 cell line is being widely used to study mechanisms of malignant transformation in vitro. As currently employed, the standard assay system uses a combination of penicillin (100 I.U./ml) and streptomycin (50 micrograms/ml) to reduce the occurrence of bacterial contamination. The penicillin component of this mixture has been discovered to cause a reduction in the number of transformed foci which develop after exposure of cells to MCA, DMBA and X-rays. This reduction is dose dependent; 500 I.U./ml virtually eliminates transformation, while 100 I.U./ml causes an approximate 50% decrease in the number of foci. This effect does not appear to be due to overt toxicity and is largely reversible on removal of the antibiotic. Gentamicin (25 micrograms/ml) causes no reduction in the formation of transformed foci when compared to cultures maintained in antibiotic-free medium and offers the advantages of chemical stability, a wider spectrum of antibacterial activity in comparison with penicillin/streptomycin and, in addition, is active against many mycoplasma. It is suggested that future studies with this cell line should ideally be performed without antibiotics or should employ Gentamicin for antibacterial protection.


Sporogenesis of a myxosporidan with motile spores.

Three types of cells comprise each Fabespora vermicola sporoblast: valvogenic (VAV), capsulogenic (CAP), and germinative (GEM). Walls, polar caps, and sutures are the main assemblages produced by the VAV cells. The unique polar cap organelle extends over the aperture region of the polar capsule component of the CAP cell. The VAV cell also assembles a wall located on the cytoplasmic side of the plasma membrane facing the sporoblast exterior. Bundles of 7 nm microfilaments develop within the extracellular space between the VAV and interior cells of the sporoblast. These microfilaments assemble late in sporogenesis when the spore acquires the capacity for locomotion. Polar filament construction takes place exclusively within the polar capsule primordium (PCP) by apparent self-assembly prior to the PCP being enveloped by membranes. The CAP and GEM cells accumulate considerable glycogen during sporogenesis. The first identifiable GEM cell is single, but has two unpaired nuclei. These GEM cell nuclei later form a paired structure which is sustained into the spore stage.


Fine structure of the monkey epididymis: a correlated thin-section and freeze-cleave study.

The epithelium of the monkey epididymis was studied by means of freeze-fracture techniques and conventional electron microscopy. For the study of transepithelial permeability lanthanum hydroxide was used as an intercellular tracer. The epididymal epithelium consists mainly of tall columnar cells. The long stereocilia at the apical surface, similarly to microvilli, exhibit after freeze-fracture, two distinct faces: the E face, concave and with fewer membrane-associated particles, and the complementary convex P face. In the lumen unusual groups of smooth-surfaced vacuoles are present. A tight junctional network, which shows some permeability to the lanthanum tracer, is located at the apical end of the cells. Supranuclear cross-fractures clearly show the well developed Golgi cisternae and numerous vacuole profiles. The highly infolded, centrally located nucleus exhibits, after freeze-fracture, an even distribution of nuclear pores. In the perinuclear region the rough endoplasmic reticulum, which also presents pores, displays a sheet-like organization. The basal cytoplasm is filled by numerous globular profiles of membrane-bounded granules. Freeze-cleave exposes large cytoplasmic areas where the types and amount of organelles indicate an intense metabolic activity.


Fine structure of isolated fibrils from the cuticle of Lumbricus sp.

A method has been developed to isolate and purify cuticular fibrils of Lumbricus. Polarizing microscopy confirms the collagenous nature of the isolated fibrils. Study in the electron microscope of isolated fibrils, negatively or positively stained, shows that they are cylindrical, unbranching and without periodic structure. Enzymatic treatment of cuticles with alpha-amylase and trypsin results in a more or less complete dissociation of the fibrils which appear clearly to be made up of helically wound bundles of filaments (30-40 A). The biophysical data and compared to the ultrastructural organization of other periodically cross-banded fibrils.


Photooxidation products of 7,12-dimethylbenz[a]anthracene.

The principal products of the photooxidation of 7,12-dimethylbenz[a]-anthracene (DMBA) in aqueous solutions by photooxidation induced by laboratory lighting have been characterized by high performance liquid chromatograms (HPLC), ultraviolet and mass spectrograms and by comparisons with authentic samples. The products identified were the 7,12-epidioxy-7,12-dihydro-7-12-dimethyl-, 7,12-dione, 7-hydroxymethyl-12-methyl-, 12-hydroxymethyl-7-methyl-, 7-formyl-12-methyl-, 12-formyl-7-methyl-, and 12-hydroxy-12-methyl-7-one derivatives of benz[a]-anthracene. The HPLC profile of products is similar to that obtained from oxidation of DMBA by 'one-electron' reagents, singlet oxygen, or liver microsomal metabolism. The first points of attack are the 7- and 12- positions. The mechanism of photooxidation appears to be generation of singlet oxygen by photodynamic effect of DMBA. None of the products is photosensitizing, however.


Evaluation of a nephelometric assay for haptoglobin and its clinical usefulness.

Serum haptoglobin has been advocated as an indicator of intravascular hemolysis. We have evaluated a nephelometric determination of serum haptoglobin. The assay is sensitive and exhibits within-run precision in the range of 2.5-7.4% coefficient of variation (CV) and between-run precision of 7.0% (CV). In addition, when haptoglobin values determined with the nephelometric assay were compared with hemoglobin-binding capacity determined by electrophoresis, the correlation coefficient was 0.968. The assay is essentially independent of phenotype and free of significant interference by hemolysis. The clinical correlation of haptoglobin values obtained for 100 selected patients with the nephelometric technique correlated well, if less than 250 mg/L, with the presence of hemolytic disease.


Neuraminidase in mucolipidoses: normal activity in frozen autopsy tissues from three patients with I-cell disease and adult beta-galactosidase deficiency.

Neuraminidase was assayed in the frozen autopsy tissues from three patients with I-cell disease and an adult patient with cherry-red spots, myoclonus, cerebellar ataxia and beta-galactosidase deficiency. Both diseases showed normal neuraminidase activity toward neuramine lactose and fetuin in cerebral gray matter, liver and kidney. These results suggest that the neuraminidase deficiency is limited only to some tissues and that this biochemical abnormality is not caused by a primary genetic mutation in these diseases.


Membrane-bound antibodies to bloodstream Trypanosoma cruzi in mice: strain differences in susceptibility to complement-mediated lysis.

The Y, CL and other strains of Trypanosoma cruzi display different morphological and immunological characteristics. Such observations are here extended to the interaction of bloodstream forms of different strains of T. cruzi with components of the complement system. We demonstrate that the bloodstream forms of the Y and B strains, but not those of the CL strain, are lysed by normal human serum. Lysis is mediated by combined activities of the alternative and classical complement pathways. These activities are triggered by antibodies on the surface of the parasites as shown by: (a) binding of fluorescein or radiolabelled anti-mouse immunoglobulin to the parasite's membrane and (b) the finding that bloodstream forms from lethally irradiated mice can be sensitized and rendered susceptible to complement-mediated lysis by incubation with sera from acutely infected animals. Bloodstream forms of the CL strain also bear surface immunoglobulin and sensitizing antibodies are present in the sera of mice infected with this strain. However, CL trypomastigotes from acutely infected mice fail to be lysed by human or mouse complement unless the parasites are pre-incubated with sera from chronically infected animals. The basis of the different interactions between CL and Y trypomastigotes with antibodies and the complement system, and their biological significance are discussed.


Suppressive effect of IgA soluble immune complexes on neutrophil chemotaxis.

The effect of IgA and IgG soluble immune complexes (SIC) on neutrophil chemotaxis was investigated. Six types of SIC were prepared from kappa-type IgA and IgG myeloma proteins: IgA-anti-kappa chain antibody SIC in IgA excess, IgA-anti-kappa chain antibody in SIC in anti-kappa chain antibody excess, IgA-anti-alpha chain antibody SIC in IgA excess, IgG-anti-kappa chain antibody SIC in IgG excess, IgG-anti-kappa chain antibody SIC in anti-kappa chain antibody excess, and IgG-anti-gamma chain antibody SIC in IgG excess. Three types of IgA SIC had a marked suppressive effect on neutrophil chemotaxis, while IgG SIC, free IgA, free anti-kappa chain antibody, and free anti-gamma chain antibody showed no inhibitory activity. This suppressive effect on neutrophil chemotaxis caused specifically by polymerized IgA was a cell-directed one and was expressed in a concentration dependent manner.


MICC cytotoxic effector function of human T lymphocyte subpopulations bearing Fc-receptors for IgG and IgM.

Purified subpopulations of human T lymphocytes bearing Fc-IgG and Fc-IgM receptors were studied for their ability to mediate mitogen (PHA) induced cellular cytotoxicity (MICC) to chicken erythrocyte (CRBC) and DBA/Mastocytoma P815Y tumour cell targets. There were marked differences in the ability of the Fc-IgG receptor-bearing T cell (T gamma) and the Fc-IgM (T mu) to mediating MICC to CRBC and P815Y target cells. T gamma cells were very efficient killers of CRBC and T mu cells had no cytotoxic activity to CRBC. On the other hand, both the T gamma and T mu subpopulations were able to mediate MICC to P815Y tumour cell targets.


Autoantibody specific for the glomerular mesangium and Bowman's capsule in man.

Investigation of serum from a nominally healthy subject revealed an unusual autoantibody with specificity for the glomerular mesangium and Bowman's capsule. Immunofluorescence studies on rodent kidney sections revealed typical mesangial fluorescence and intense linear staining of Bowman's capsule. The antibody was organ, but not species, specific and did not correspond to any previously described antibody with anti-mesangial activity (e.g. anti-actomyosin or anti-fibronectin). Intravenous injection in mice resulted in heavy mesangial deposition of antibody within one hour, the antibody disappeared within 2--4 weeks, and no urinary abnormalities were seen. Retrospective analysis of clinical data revealed a history of chronic hepatitis and possible drug abuse, but no evidence for impaired renal function at any timepoint. To our knowledge this is the first report of specific anti-mesangial antibody in man, the pathogenetic relevance remains unclear.


Finger print deposits of the kidney in pure monoclonal IgG kappa cryoglobulinemia.

In a male patient with pure monoclonal IgG kappa cryoglobulin associated with the nephrotic syndrome, finger print deposits were observed in the subendothelial space and mesangial matrix of the kidney by electron microscopy. The structure was similar to a unique tubular crystal structure of IgGl kappa cryoglobulin which was reported by Bogaars et al. [1973] in the serum of a patient with multiple myeloma. It was therefore supposed that the finger print deposits in the kidney of this patient were the precipitation of the monoclonal IgG kappa cryoglobulin in serum.


Pre-infarction angina secondary to calcific aortic stenosis with Bernheim's effect.

Pre-infarction angina, in the absence of coronary artery disease, was found in a 62 year-old man with severe calcific aortic stenosis. After application of intraaortic balloon pump counter-pulsation, the condition was stabilized, and coronary arteriograms were safely carried out. Interestingly, an elevated right atrial and right ventricular end-diastolic pressure with an associated Bernheim's effect was demonstrated by cardiac catheterization. The hemodynamics of the right heart returned to normal after surgical correction of the aortic stenosis. The clinical indications for intra-aortic balloon pump counterpulsation in this setting are discussed.


Non-parenteral combined afterload and preload reduction therapy in congestive heart failure.

It has been shown that hydralazine is beneficial in chronic heart failure by virtue of its afterload reducing effect. Nitroglycerin paste results in venodilation and fall in left ventricular filling pressure (LVFP). Thirteen patients with chronic heart failure were given a combination of oral hydralazine and nitroglycerin paste. With oral hydralazine (75 to 100 mg every 8 h), left ventricular stroke work increased and LVFP slightly fell. Following addition of 2% nitroglycerin paste, an additional decline in mean pulmonary artery and LVFP was observed without significant changes in heart rate and arterial pressure. There were no untoward side effects from either therapy. Eight patients followed for three to eight months (mean five months) reported subjective improvement in shortness of breath and other symptoms related to ventricular dysfunction. This study shows that in certain patients with chronic heart failure, hydralazine and nitroglycerin paste combination produces salutary clinical effects on long term probably through afterload and preload reduction, respectively.


Fractures of the fibula at the distal tibiofibular syndesmosis.

Two basic fracture types are found at the level of the syndesmosis, supination-external rotation (SE) and pronation-abduction (PA), reflecting the mechanism of injury. The SE-type fracture of the fibula extends from the anterior edge in a posterosuperior direction, and the PA-type fracture extends from the medial surface either transversely or obliquely in a laterosuperior direction, and are often comminuted. The SE-types exist in 2 locations above and below the anterior fibular tubercle. All 3 types exist also in atypical forms. Treatment of the initial stages is by cast immobilization, and advanced lesions are treated by open reduction and internal fixation of the medial and lateral lesions of the ankle. The most common type of Wagstaffe fracture was type 2 which represents fractured anterior spike of the proximal fragment of the fibula.


Therapy of the spondyloarthropathies.

The key to successful therapy for patients with ankylosing spondylitis is a lifelong, carefully devised, and well-instructed exercise program. This program is designed to maintain maximum range of motion within the spine, and the costovertebral and girdle joints, thereby preventing the tendency to flexion contractures and loss of height. The exercise program frequency requires long-term concomitant therapy with nonsteroidal anti-inflammatory drugs, partly to relieve the painful perispinal muscle spasm which frequently inhibits the exercise movements. The drugs are not known to alter the natural history of the inflammatory lesion. Local measures directed at ocular, urethral, and mucocutaneous inflammation may be symptomatically beneficial. These simple therapeutic principles ensure a good functional prognosis in the vast majority of patients with spondylitis.


Treatment of rhesus monkeys (Macaca mulatta) with intravaginal rings impregnated with either progesterone or norethisterone.

The effects of both progesterone- and norethisterone-loaded intravaginal rings were investigated in twenty-five rhesus monkeys for 52 weeks. The intravaginal rings were designed to provide a sustained release of either the human dosage level of the hormone or ten times this level. Untreated placebo rings were used for control purposes. The devices were well retained. With the exception of increased plasma fibrinogen levels in animals treated with norethisterone, no marked differences in either local or systemic toxicity between the progesterone and norethisterone intravaginal rings were apparent. Following insertion of the hormone-treated intravaginal rings, a dose-related decrease in vaginal bleeding was recorded. The vaginal microbial flora were assessed qualitatively and semiquantitatively and all groups including the placebo controls showed a changes in mcirobial populations. Terminal studies indicated that at high dose levels, ovulation was suppressed and widespread atrophy of the uterine mucosal and glandular endometrial epithelium had occurred. An increase in cervical mucus was observed within the lumen of the endocervical canal in a proportion of hormone-treated animals. In the vagina, a dose-related focal or diffuse atrophy of the mucosal epithelium was found.


Calcium measurements in serum and plasma--total and ionized.

This article will review the methods currently employed for measuring the concentrations of total and ionized calcium in serum or plasma. As far as total calcium is concerned, various techniques such as atomic absorption spectrometry, spectrophotometry, fluorometry, complexometric titration, and flame photometry will be described and compared. Particular emphasis will be given to the accuracy and precision of each technique. Possible sources of error and interfering agents will be identified and the various procedures for the taking and handling of blood samples evaluated. Inter-laboratory variation in the measurement of calcium will be studied. An assessment will be made of a new reference method for measuring total calcium in serum using isotope-dilution mass spectrometry. The usefulness of the total calcium measurement in clinical medicine will be briefly discussed. Within the last decade the refinement of spectrophotometric techniques and the improvements in ion-selective electrode technology have revolutionized the measurement of ionized calcium in serum, such that it may now be possible to replace total calcium measurements with ionized calcium measurements on a routine basis. The various techniques currently in use for measuring ionized calcium will be described and evaluated. Particular attention will be paid to the preparation of standards, the procedures for taking blood samples, and the handling of the samples prior to and during measurement. An assessment of the relative value of measuring total and ionized calcium will be presented.


Protein and caloric or macronutrient metabolic management of the critically ill patient.

Aggressive and early use of nutritional support therapies in critically ill patients represents a major advance in critical care medicine. The net protein catabolism and erosion of protein stores which is characteristic of the metabolic response to injury results in significant added morbidity and mortality in critical care units. The early administration of appropriate protein and energy in support of enhanced demands will maintain host defense and preserve organ function, thus, allowing time for stabilization of clinical status while life support strategies are implemented. In all circumstances, protein, vitamins, minerals, and nonprotein calories must be provided within fluid and electrolyte restrictions and in conjunction with optimal hemodynamic and pulmonary support.


The use of immobilized enzymes in the food industry: a review.

The production of high fructose corn syrups was greatly facilitated by the use of immobilized glucose isomerase. Similarly, in Japan, the fermentation industry proved its processing efficiency for amino acids through the use of immobilized amino acid acylase. This article discusses the use of soluble enzymes in the food industry followed by a section on the various available methods to immobilize enzymes. Once enzymes are immobilized, many of their operational parameters could be altered. Rationale for the determination of the effects of immobilization is provided. A relatively new concept is the use of a single matrix for immobilizing more than one enzyme. Immobilized multi-enzyme systems offer many attractive advantages; however, such a process also raises some interesting questions about kinetics. These questions and their suggested answers are discussed in the penultimate section. The major emphasis of this article is on the use of immobilized enzymes in the food industry. Two systems--amino acylase and glucose isomerase--have been demonstrated to be techno-economically feasible. Immobilization of other enzymes, such as glucoamylase, lactase, protease, and flavor modifying enzymes, has received some attention. The potential of these new systems are also discussed.


Chromosomal evolution in Malagasy lemurs. IV. Chromosome banding studies in the genuses Phaner, Varecia, Lemur, Microcebus, and Cheirogaleus.

The karotypes of five species of Malagasy lemurs are described and compared with those of 12 previously studied species or subspecies. Based on these studies, phylogenetic relationships among nearly all the species of Cheirogaleidae and Lemuridae are proposed. The karyotype of the common ancestor is identical or very similar to that of Microcebus. Nearly 60 chromosomal changes, including five intrachromosomal rearrangements of the X chromosome, have been detected during the evolution of these two families. The possible evolutionary role of the different chromosomal rearrangements is discussed.


Chromosomal unit fibers in Drosophila.

Chromosomal unit fibers consisting of long, regular fibers of about 0.40 micron diameter were obtained from disintegrated, isolated chromosomes of two Drosophila melanogaster cell lines. In one cell line with an essentially normal karyotype, three clearly defined size classes of 15,13, and 11 micron length were observed corresponding to the three larger chromosomes of Drosophila. In a cell line carrying an additional translocation between the two largest chromosomes a 19 micron fiber derived from the translocation chromosome was observed. Direct determinations of the DNA content per micron length of Drosophila unit fibers show that DNA is contracted by a factor of about 1400x  in agreement with calculations based on the length of the unit fibers and the known DNA content of the individual Drosophila chromosomes. These findings support our previously proposed model for the unit fiber sub-structure of chromosomes as being derived by a hierarchy of coiling with the corresponding contraction ratios being 7 (100 A string of nucleosomes), 5 to 6 (250-300 A thick nucleohistone fiber), and about 40 (unit fiber), resulting in a total contraction of DNA in unit fibers in the order of 1400x.


The occurrence of long transcription units among the X and Y ribosomal genes of Drosophila melanogaster: transcription of insertion sequences.

Most of the ribosomal transcription units (rTUs) in Drosophila melanogaster observed by electron microscopy measure about 8 kb; a length which corresponds to the size of the 38S precursor to ribosomal RNA in D. melanogaster. However, interspersed among these rTUs are transcription units that are much longer (up to 14.6 kb) than the 8 kb expected for rTUs. Some of these larger length estimates can be attributed to stretching but an important fraction is significantly larger and has up to 60 more fibers per gene.--The following evidence suggests that these larger transcription units are ribosomal genes consisting of insertion sequences. The long transcription units are within the sizes expected for rTUs containing insertion sequences as reported by other workers. Their RNP fibers cross-react with antibodies raised against ribosomal proteins in a manner similar to that observed for ribosomal RNP. They are interspersed among rTUs in the X chromosome.--These putative ribosomal genes carrying insertions are present both in the X and, although to a lesser extent, in the Y ribosomal chromatin as is indicated by their existence in nurse cells of both Oregon R females and females of the genotype sc4sc8/sc4sc8/y+ Y. Analysis of the fiber patterns of "long TUs" supports the hypothesis that the insertion region is being transcribed.--"Long TUs" are found in tandem with non-transcribed spacer regions which are heterogeneous in length with a mean of 1.53+/-0.61 micrometers (or 8.5+/-3.4 kb).


3H-uridine incorporation in the puff 93D and in chromocentric heterochromatin of heat shocked salivary glands of Drosophila melanogaster.

The autoradiographic patterns of 3H-uridine labelling of the major temperature shock puff sites and the chromocentric (beta-)heterochromatin in heat shocked (37 degrees C) salivary glands of Drosophila melanogaster have been studied. It is seen that in response to the heat shock treatment, four of the major temperature shock puffs (63BC, 87A, 87C and 95D) show a correlated level of 3H-uridine incorporation in a given nucleus. However, although the mean grain density on 93D puff is maximum in the heat shocked preparations, in individual nuclei this puff is labelled to a widely varying level and this variation in its labelling is statistically not correlated to the labelling of the other four temperature shock puffs in a nucleus. The chromocentric beta-heterochromatin, which has been shown in several earlier studies to hybridize with temperature shock RNA fractions, is seen to be totally inactive in transcription after the heat shock.


Genetic instability in Drosophila melanogaster: tandem duplications as monitors of intrastrand exchange.

Two tandem duplications of the X chromosome associated with the white eye color locus are described. In heterozygous females both revert to a nonduplicated chromosome without detectable meiotic recombination. Clustering of revertants suggests the reversion event occurs in the germ line prior to meiosis. Similarly in males one duplication also reverts with clustering implying a premeiotic event. Revertant X chromosomes derived from males are either nonduplicated or deleted. Intrastrand exchange can account for some but not all revertants recovered.


Hypocalcemia, hypomagnesemia, and transient hypoparathyroidism during therapy with potassium phosphate in diabetic ketoacidosis.

The effects of intravenous administration of potassium phosphate in the treatment of diabetic ketoacidosis were studied in nine children, ages 9 9/12 to 17 10/12 yr. During phosphate infusion (20--40 meq/L of fluid), all children maintained normal serum concentrations of phosphorus. Transient hypocalcemia occurred in six and transient hypomagnesemia in five patients. One child developed carpopedal spasms refractory to intravenous infusion of calcium gluconate but responsive to intramuscular injection of magnesium sulfate. In three patients, serum levels of intact parathyroid hormone were low at the time of hypocalcemia, an observation that suggests transient hypoparathyroidism. This study indicates that the use of potassium phosphate as the sole source of potassium replacement might potentiate ketoacidosis-induced hypocalcemia through multiple mechanisms.


Pathogenesis of diabetic ketoacidosis: a reappraisal.

This study reviews the pathogenic hormonal abnormalities (insulin deficiency and stress hormone excess) in diabetic ketoacidosis. The data both supporting and negating a primary role for insulin deficiency in the pathogenesis of diabetic ketoacidosis are examined. Evidence implicating excess stress hormone secretion as a necessary event in the development of severe metabolic decompensation is discussed. The data suggest that diabetic ketoacidosis may be prevented by correcting either the relative deficiency of insulin or the excess secreation of one or a combination of the stress hormones. Studies supporting a primary role for insulin deficiency in the pathogenesis of diabetic ketoacidosis include the beneficial therapeutic response to insulin administration in ketoacidosis, development of ketoacidosis; and (3) stress hormone excess is necessary for fulminant ketoacidosis to be manifested.s following insulin withdrawal from diabetic man and animals, and hypoglycemic and hypoketonemic effects of insulin. Studies negating a primary role for insulin deficiency in ketoacidosis include the "normal" plasma insulin concentration in the majority of ketoacidotic cases, delayed onset of ketoacidosis after insulin withdrawal from diabetic man, and lack of hypolipolytic and hypoketonemic effect of insulin without prior stress hormone adipocyte and hepatocyte stimulation. Evidence that stress hormones (glucagon, catecholamines, cortisol, and growth hormone) contribute to the metabolic decompensation of ketoacidosis includes: (1) in all cases of ketoacidosis, at least one stress hormone is always elevated; (2) pharmacologic blockade of each of the stress hormones reduces the rate and/or frequency of metabolic decompensation in diabetic man; (3) removal of the pituitary and/or the adrenal gland in diabetic animals completely prevents the development of ketoacidosis after insulin withdrawal; and (4) administration of each of the four stress hormones under appropriate conditions induces metabolic decompensation in diabetic man with "normal" circulating levels of plasma insulin concentration. From these studies, the following conclusions are supported: (1) absolute insulin deficiency is an unusual cause of ketoacidosis; (2) the presence of relative insulin deficiency is necessary for the development of ketoacidosis; and (3) stress hormone excess is necessary for fulminant ketoacidosis to be manifested.


Evidence for a rapid in vivo effect on estradiol-17 beta on prolactin secretion in ovariectomized rats.

Repeated intraarterial injections of synthetic thryrotropin releasing hormone (TRH, 1 microgram/rat) increased plasma prolactin levels 4 hours after a single subcutaneous injection of 10 micrograms estradiol-17 beta (E2-17 beta) in rats ovariectomized 1, 2 or 4 weeks and at 2 hours after E2-17 beta injection in rats ovariectomized for 6 weeks. The effect of TRH was still present at 24 but not 48 hours after estradiol treatment. TRH-induced increases in plasma prolactin were similar in groups of rats treated with 10 micrograms E2-17 beta (s.c.) or implanted with 0.5 cm Silastic capsules of crystalline E2-17 beta (s.c.) whereas smaller, yet significant, TRH-induced increases in plasma prolactin were observed in rats injected s.c. with 1.0 microgram E2-17 beta. Single intraarterial injections of TRH at 4 or 8 hours after E2-17 beta treatment induced increases in plasma prolactin similar in magnitude to those observed at the same times after E2-17 beta in rats given repeated TRH injections. No effect of TRH was observed in ovariectomized rats given sesame oil and E2-17 beta treatment did not influence plasma prolactin in rats given saline instead of TRH. Intraarterial administration of serotonin creatinine sulfate (5-HT, 10 mg/kg body weight) induced marked increases in plasma prolactin in rats ovariectomized for 4 weeks which were potentiated at 2 and 6 hours after E2-17 beta (10 micrograms) treatment. The data show that estradiol has a fairly rapid stimulatory effect on plasma levels of prolactin induced by two different secretagogues but the exact site and mechanism of action remain unresolved.


Effect of nutritional counseling on the blood glucose and nutritional knowledge of diabetic subjects.

The nutritional knowledge and control of diabetes was assessed in 43 nonketosis-prone diabetic subjects. Patients were semiliterate or illiterate. They were exposed to a 1-h nutritional counseling program in groups of three to five. The nutritional counseling program was highly simplified and emphasized only a few important aspects of diabetic diet. Patients' nutritional knowledge improved significantly after nutritional counseling. The control of diabetes also improved significantly in those patients in whom control had been inadequate.


In vivo patterns of circulating steroids in adult male rats III. Effect of total parenteral nutrition on the diurnal variation of testosterone.

The in vivo pattern of circulating testosterone (T) during a 24 hr period was investigated in stock-fed and total parenterally nourished (TPN) rats. A diurnal rhythm of T was observed in control rats with highest concentrations occurring during the dark period. The loss of this rhythm in rats maintained on TPN shows that nutritional regimen affects circulating T and overrides the synchronizing effect of the light/dark cycle.


Comparison of the effect of TRH on plasma TSH level in young and adult rats.

Since it is known that TRH degrading system in plasma is inactive during suckling period in the rat, it was of interest to see whether this might prolong the effect of TRH on plasma TSH. Time course of plasma TSH after s. c. administration of 2 ng TRH g-1 was studied in 7, 48 and 120 day-old rats. The highest basal TSH level (448 +/- 72 microU ml-1) was found in 48 day-old males, while it was the lowest (82 +/- 22.8 microU ml-1) in 7 day-old animals. Time course was essentially the same in all three age groups. If the increase of plasma TSH was compared to the level of saline treated controls at the same time, 8.2 and 10.1 fold increase was found 10 and 30 min after TRH injection, respectively, in 7 day-old pups. However, the increase was only 2.3 and 3.4 fold in older animals at the same time intervals. The highest absolute level obtained during TRH stimulation was found in 48 day-old animals (1055 +/- 121.6 microU ml-1). These results show that the effect of TRH on plasma TSH was not prolonged in neonatal rats thus suggesting that extravascular TRH degradation may be of some importance in TSH regulation.


Perinatal period and pregnancy: intervals of high risk for chemical carcinogens.

Experiments in rodents indicate that during the post-embryonic period of prenatal development, the fetus is more sensitive than the adult to certain carcinogens, by several decimal orders of magnitude. Most such agents are direct-acting and independent of metabolism. To other substances, often those which require enzyme-mediated metabolic conversion to a chemically reactive derivative in order to effect carcinogenesis, the fetus may be less vulnerable than the adult. The neonate is also more susceptible than adults to some carcinogens, and may be more susceptible than the fetus to certain agents. Both rodent and primate studies indicate that gravid females are also at elevated risk for carcinogenesis, in part because of the presence in the placenta of trophoblastic tissue which may become malignant. The contributions of rapid growth rate, changing metabolic competence, and tissue differentiation to elevated perinatal susceptibility to carcinogens in rodents and primates are discussed, together with the implications of these findings for human beings subjected to industrial or environmental exposures to such chemicals.


A phylogenetic study on vertebrate mitochondrial DNA polymerase.

We have started a phylogenetic survey for the mitochondrial DNA polymerase and present in this study the results obtained for all the different classes for the vertebrates. The operating conditions include the purification of mitochondria, the analysis of the DNA polymerase activity in the extract and the determination of the sedimentation coefficient on sucrose gradients. The utilization of digitonin for removing the external membrane of the organelle and contaminating proteins has been generalized since this detergent shows no effect on the activities of either DNA polymerases alpha or gamma. The results obtained for the mitochondria of different classes of vertebrates show that the activity responding to the specific assay of DNA polymerase gamma tended invariably to increase during purification while that of DNA polymerase alpha tended to decrease. Furthermore in almost all the cases the gamma-polymerase represented the only DNA polymerase activity found in the mitochondria after digitonin treatment. The analysis of the sedimentation patterns of the mitochondrial DNA polymerase strongly suggests the presence of a single type of DNA polymerase showing the typical properties of the gamma-polymerase. It is concluded that the vertebrate mitochondria contain a well-defined and unique form of DNA polymerase which corresponds to the DNA polymerase gamma.