Measurements of prolactin and growth hormone synthesis and secretion by rat pituitary cells in culture.

A specific and sensitive immunoprecipitation method for measurements of biosynthesized radioactive prolactin and growth hormone is described. Antisera to rat prolactin and growth hormone were developed in the rabbit and monkey, respectively. The specificity of the immune sera was assessed by polyacylamide gel electrophoresis of the dissolved immunoprecipitates. The two antisera showed cross-reactions with the nonhomologous hormone of less than 1%. Separation of tritium-labelled prolactin and growth hormone by immunoprecipitation, followed by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate was shown to be 95-57% complete. When both hormones were measured in the same microsample by sequential immunoprecipitation, the reaction was 97% complete for determination of intra- and extracellular prolactin and extracellular growth hormone, but 85% complete for determination of intracellular growth hormone. This method has been used to characterize the basal synthesis and secretion of prolactin and growth hormone in three different but related, pituitary cell strains. Radioactive prolactin and growth hormone was obtained from monolayer cultures when the cells were grown in the presence of [3H]L-leucine. The rate of prolactin synthesis and extracellular accumulation was higher than that of growth hormone in a cell strain which produced both hormones. In these cells prolactin synthesis represents 1-5%, and growth hormone 0.1-0.6% of total protein synthesis.


Effects of parathormone and calcitonin on citrate and hyaluronate metabolism in cultured bone.

Two metabolic correlates of parathormone-induced bone resorption are increased synthesis of hyaluronate and decreased production of CO2 from citrate. We have examined these phenomena simultaneously with calcium release in cultured mouse calvaria and fetal rat radii and ulnae treated with parathormone and calcitonin, separately or in combination. In both types of tissue the parathormone dose-response curves for inhibition of citrate decarboxylation, enhanced hyaluronate synthesis, and increased release of calcium were identical when measured 48 h after treatement. In each case a minimum response occurred at approximately 0.01 mug parathormone per ml and a maximum response at about 0.1 mug per ml. The time courses of these responses to parathromone were different. Hyaluronate synthesis increased within 1 h after treatment and peaked at 6 h; decarboxylation of citrate declined after 3 h; demineralization of the bone was not detected until 24 h. When parathormone-treated bones were placed in parathormone-free medium, citrate decarboxylation returned to control levels within 24 h, but increased synthesis of hyaluronate and demineralization persisted for at least 24 h more. When calcitonin was added to bones which were treated with parathormone, the parathormone-induced inhibition of citrate metabolism did not change, but both hyaluronate synthesis and demineralization rapidly declined. Subsequently the rate of hyaluronate synthesis increased, and this was followed several hours later by an increase in demineralization. These data suggest that citrate and hyaluronate metabolism are involved in the overall response of bone to parathormone but are only loosely coupled to one another. Synthesis of hyaluronate appears to be more closely related to subsequent calcium release than is citrate metabolism.


A detailed characterization of the proestrous luteinizing hormone surge.

Four-day cycling rats were kept in a room with the light on from 0500-1900 h. Plasma LH concentrations in blood withdrawn through atrial cannulas at hourly intervals from 1400-2000 h on proestrus were very similar to serum LH concentrations in blood collected from uncannulated rats by decapitation at these times. Additional cannulated rats were bled (0.1 ml) at 5 min intervals from 1400-1600, 1600-1800, or 1800-2000 h. After each bleeding, 0.1 ml of heparinized saline was injected through the cannula. Following a rise (rate unknown) to detectable levels of about 200 ng/ml, plasma LH displayed a rapid linear increase to 1538 +/- 118 ng/ml, starting between 1445 and 1650 h and lasting 20 to 50 min. Over the next 110 min plasma LH at first rose erratically by about another 200 ng/ml and then fluctuated around an apparent plateu. It then dropped rapidly but the declines were commonly interrupted by one or more rapid increases in plasma LH. A generalized pattern of the proestrous LH surge has been constructed from the data.


Preparation and characterization of the active derivative bovine trypsin-kallikrein inhibitor (Kunitz) with the reactive site lysine-15 -- alanine-16 hydrolyzed.

The derivative of the trypsin-kallikrein inhibitor (Kunitz), TKI+, was prepared with the reactive-site peptide bond Lys-15-Ala-16 hydrolyzed. This was achieved by selective borohydride reduction of the Cys-14-Cys-38 disulfide bond, followed by tryptic cleavage of the reactive-site peptide bond, air reoxidation of the half-cystine residues, and purification by ion-exchange chromatography. The derivative corresponds to the hypothetical 'modified' inhibitor TKI+, which so far could not be obtained from virgin inhibitor by a direct modification reaction (partial proteolysis). The derivative isolated was homogeneous as revealed by amino acid analysis, disc electrophoresis, inactivation by carboxypeptidase B, and inactivation by sodium borohydride reduction. The inhibitory activity of the sodium-borohydride-reduced inhibitor was fully recovered after air reoxidation. The site of cleavage in the inhibitor was confirmed by performic acid oxidation and subsequent isolation of the two corresponding peptides containing residues 1-15 and 16-58 of the entire polypeptide chain. From several aminopeptidases tested only aminopeptidase K rapidly cleaved Ala-16 and Arg-17 from the modified inhibitor and at a reduced rate Ile-18. Des-(Ala16,Arg17)-inhibitor and des-Ala16-inhibitor are both lacking a strong inhibitory activity against bovine trypsin. This indicates a decrease in the association constant by factor of at least 10(8)-10(10). The reactive-site-modified inhibitor is not subject to further enzymic breakdown and therefore is a permanent inhibitor of trypsin. However, the modified inhibitor forms the inactive complex much slower than virgin inhibitor. In the modified inhibitor the hydrolyzed peptide bone was resynthesized to yield virgin inhibitor by forming the complex with trypsin and subjecting the complex to kinetic control dissociation. This proves that the bond Lys-15--Ala-16 is at the reactive site of this inhibitor. Preparation of a modified and still active inhibitor (Kunitz) is in agreement with the general model proposed for the interaction of proteinase-inhibitor--proteinase interactions. This presents new evidence that this model is generally applicable.


The mechanism of enzymatic cellulose degradation. Purification and some properties of two different 1,4beta-glucan glucanohydrolases from Trichoderma viride.

1. A low-molecular-weight and a high-molecular-weight 1,4beta-glucan glucanohydrolase (Cx enzyme) have been isolated from a commercial cellulase preparation derived from culture filtrates of the fungus Trichoderma viride. 2. The purification method for the isolation of the low-molecular-weight enzyme is a three-step procedure including chromatography on Bio-Gel P-10, chromatography on a dipolar adsorbent (arginine-Sepharose 6 B) and isoelectric focusing. 3. The starting material for the isolation of the high-molecular-weight enzyme was pre-fractionated by chromatography on Bio-Gel P-10, by DEAE-Sephadex chromatography and by SE-Sephadex chromatography as described previously by us. Further fractionation of this material was achieved by affinity chromatography and repeated isoelectric focusing. 4. Free zone electrophoresis of the low-molecular-weight enzyme indicated a homogeneous protein. The high-molecular-weight enzyme was homogenous in sedimentation equilibrium analysis. 5. The molecular weights of the enzymes were 12 500 and 50 000 +/- 2000 respectively. The former value was determined by chromatography on a calibrated column of Bio-Gel P-100 and the latter value by sedimentation equilibrium analysis. 6. The low-molecular-weight enzyme was isoelectric at pH 4.60 (10 degrees C) and contained 21% carbohydrate. The corresponding values for the high-molecular-weight enzyme were pH 3.39 and 12%. 7. Both enzymes were active in releasing free fibers from filter-paper. The low-molecular-weight enzyme was estimated to be about twice as effective as the high-molecular-weight enzyme in this regard.


Formation of uridine diphosphate 2-deoxy-D-glucose and guanosine diphosphate 2-deoxy-D-glucose in vitro using animal enzymes.

The enzymic formation of guanosine diphosphate 2-deoxy-D-glucose and uridine diphosphate 2-deoxy-D-glucose from synthetically prepared 2-deoxy-D-glucose 1-phosphate is described. Incubation of 2-deoxy-D-glucose 1-phosphate with an enzyme preparation from bovine mammary glands and either GTP or UTP gives rise to the corresponding nucleoside-diphosphate derivative of 2-deoxy-D-glucose. Uridine diphosphate 2-deoxy-D-glucose could also be obtained by incubation of 2-deoxy-D-glucose 1-phosphate with UTP and UDP glucose pyrophosphorylase from beef liver.


Cerebrospinal fluid pressure studies in normal pressure hydrocephalus and cerebral atrophy.

The surgical results obtained with a cerebrospinal fluid (CSF) shunt operation in 13 patients considered to be suffering from normal pressure hydrocephalus have been correlated with the findings of the constant manometric infusion test (IT) and of prolonged intracranial pressure recordings. A positive IT, high amplitude CSF pulse pressure and large transitory increases of CSF pressure during sleep seem to be useful criteria for the surgical prognosis. Ten more patients affected by primary cerebral atrophy have also been studied. The data obtained in both groups of patients have been utilized for a possible pathogenetic interpretation of the syndrome.


Effect of pulverized implantation materials (plastic and glass ceramic) on growth and metabolism of mammalian cell cultures.

The effect of pulverized plastic and glass-ceramic materials (methylmetacrylate, MNA), which are used as implantation materials in surgical medicine, on cell growth, DNA synthesis rate (adjudged by incorporation of 3H-thymidine into DNA), glucose consumption and lactate production (glycolytic rate) was studied in asynchronous monolayer cultures of rather fast proliferating Ehrlich ascites tumor cells and rather slowly proliferating diploid human fibroblasts. Exposure of Ehrlich ascites cells to high concentrations (2 mg/ml; 10 ml medium per culture) of ceramic or plastic material resulted in a gradual inhibition of cell growth and DNA synthesis rate. Protein synthesis, as measured by the incorporation of 3H-leucine, was somewhat less affected than DNA synthesis. Also, the glycolytic rate of Ehrlich ascites cells was slightly but significantly decreased in the presence of 2 mg/ml ceramics or MMA. Exposure of Ehrlich ascites cells to 0.2 or 0.02 mg/ml over a period of 46 h revealed none or only slight inhibitory effects on growth, DNA synthesis or glycolytic rate. On the other side, growth, DNA synthesis and glycolytic rates of human fibroblasts were nearly not affected by the presence of the same concentrations (up to 2 mg/ml, incubation period: 92 h) of pulverized ceramic or plastic material (MMA). It is suggested that this differential cellular sensitivity might be related to differences in the binding (to the cell surface) or uptake of these substances and possibly to differential intracellular lysosomal activation.


Non-specific supersensitivity of striatal dopamine receptors after 6-hydroxydopamine lesion of the nigrostriatal pathway.

6-Hydroxydopamine (6-OHDA) was injected unilaterally into the area of the ascending dopamine pathways in the lateral hypothalamus. Rats immediately developed spontaneous ipsilateral circling which was enhanced by d-amphetamine (0.63-2.5 mg/kg i.p.) and reversed to a contralateral response by apomorphine (0.015-0.5 mg/kg s.c.). These effects were maximal by the 8th postoperative day. At a time when circling responses were established and biochemical determinations showed striatal dopamine levels to be reduced by at least 80% (limbic dopamine depleted by 60%, telencephalic noradrenaline by 35% but no reductions in 5-hydroxytryptamine), the injection of dopamine (50, 100 mug) and apomorphine (12.5, 25 mug) into the striatum ipsilateral to the 6-OHDA lesion induced contralateral circling/asymmetries. These effects were of lower intensity or absent in non-lesioned rats but a consistent increase in potency of dopamine after 6-OHDA could not be demonstrated. However, similar injections of 5-hydroxytryptamine and noradrenaline, which are completely inactive in normal rats, caused more marked contralateral asymmetries/circling at lower intrastriatal doses than dopamine (5-hydroxytryptamine 25-100 mug, noradrenaline 6.25-100 mug). Dyskinesias of the contralateral forelimb were induced by unilateral intrastriatal dopamine (100 mug) in a small proportion of non-lesioned rats: the effects were enhanced when dopamine (50-100 mug) was injected into the striatum ipsilateral to a 6-OHDA lesion. Both potency and intensity of effect were enhanced. Noradrenaline (25-100 mug) also induced contralateral dyskinesias in the 6-OHDA-lesioned rats although similar injections were inactive in non-lesioned rats. 5-Hydroxytryptamine was inactive in this effect in both groups of rats. It is suggested that after 6-OHDA lesion of the nigrostriatal pathway striatal dopamine receptors may change both their sensitivity and specificity.


Morphine suppression of ethanol withdrawal in mice.

The acute administration of morphine, alcohol or dopamine results in a pronounced suppression of the convulsions produced by alcohol in mice. The suppressive action of morphine on alcohol withdrawal in the mouse apparently is not a product of morphine intoxication, but rather to some other specific interaction between alcohol and morphine in the central nervous system. The conclusion suggest that dopamine may play a significant role as a modulator in convulsions produced during alcohol withdrawal.


Incorporation of tritiated uridine during pachytene and diplotene stages in the oocytes of the Japanese quail (Coturnix coturnix japonica).

Incorporation of 3H-uridine was studied during pachytene and diplotene stages of quail oocytes. No labelling could be detected during early pachytene. During advanced and late pachytene, labelling simultaneously appeared on the macrochromosomes and on certain michromosomes in the zone where they emerge from the chromocentric surface periphery. The latter localization corresponds to the region of ribosomal RNA synthesis. At diplotene the same localizations were labelled with a considerably increased intensity.


Intraovarian pressure changes during ovulation in rabbits.

Contractile elements are found in the ovaries of many species, but it has not been possible to ascertain whether these elements are of importance in the process of ovulation. In this report, we describe changes in intraovarian pressure recorded continuously in vivo in unanesthetized rabbits under normal conditions and under the influence of intravenously injected human chorionic gonadotropin (hCG), as well as following the ovulatory stimulus of normal copulation. The recordings were made by means of small latex balloons (0.02- to 0.04-ml volume) attached to indwelling catheters, inserted into the ovarian stroma, and secured with 6-0 nylon sutures. All 24 rabbits studied showed changes in intraovarian pressure indicative of ovarian contractile activity. The intraovarian pressure changes followed a characteristic pattern which was different from the changes in intratubal pressure, recorded simultaneously from the lumen of the ipsilateral fallopian tube, indicating that the contractions of both organs occurred independently. In normal animals, before an ovulatory stimulus was applied, the ovarian contractility pattern consisted of a series of rapid contractions (average amplitude, 6 mm Hg; average frequency; 8 per minute) occurring with intervals of quiescence lasting from 11 to 36 minutes. The base line tonus was frequently elevated during these series of contractions. Mating or an injection of hCG had no immediate effect on intraovarian pressure but, 6 to 8 hours after the stimulus was applied, ovarian contractile activity increased significantly in all rabbits. This enhanced activity persisted for several hours before returning to initial levels approximately 15 to 18 hours after mating or the hCG injection. This demonstration of increased contractile activity about the time of ovulation suggests that ovarian contractions participate in the process of follicular rupture and the extrusion of ova at ovulation. Prostaglandin F2alpha, norepinephrine, and oxytocin were effective in inducing ovarian contractions.


Provocation of postural hypotension by insulin in diabetic autonomic neuropathy.

The effect of insulin administration on blood pressure has been investigated in eight diabetes with autonomic neuropathy. Systolic and diastolic pressures fell considerably after insulin in all of them. This effect was aggravated by tilting to the vertical position. Five patients fainted when upright with systolic blood pressures less than 50 mm. Hg. This hypotensive effect of insulin occurs whether it is administered intravenously, intramuscularly, or subcutaneously. The onset of the effect is almost immediate after intravenous insulin, is progressive, and may last for several hours. It coincides with a falling blood glucose level and occurs before hypoglycemic levels are reached, and it may be present when the blood glucose level is still elevated. Diurnal variations of postural hypotension have been recorded in some patients, the standing blood pressure falling with the onset of insulin action and rising again as the latter declines. Some of our patients were unable to differentiate between symptoms of hypoglycemia and hypotension. Postural hypotension may account for some episodes of sudden loss of consciousness without warning, usually attributed to hypoglycemia.


Effect of dopamine on the esophageal smooth muscle in vivo.

Intravenous administration of dopamine caused a dose-dependent reduction in the lower esophageal sphincter pressure and contractions in the lowermost part of the body of the esophagus in the opossum. A dose of 5 mug per kg produced maximal response. The onset of contractions in the body occurred around 20 sec after the onset of the sphincter response. The effect of dopamine was different from isoproterenol, which caused no contractions in the body and caused reduction in sphincter pressure, and from phenylephrine, which also caused no contractions in the body but caused contraction of the sphincter. Moreover, the effect of 5 mug per kg of dopamine was blocked by haloperidol but not by phentolamine, propranolol, bilateral cervical vagotomy, or tetrodotoxin. These studies suggested the presence of selective dopamine receptors which mediated contraction of the esophageal body and relaxation of the sphincter muscle. Since vagal stimulation also causes contraction in the body and relaxation of the sphincter, it was possible that vagal effect on the esophagus was mediated by dopamine receptors. However, haloperidol did not block the effect of electrical stimulation of vagus nerve on body of the esophagus or the lower esophageal sphincter.


[Clinical relevance of prolactin. Results of a round-table (author's transl)].

1. The physiological regulation of prolactinsecretion and the causes of hyperprolactinemia are described. 2. Main symptomes of hyperprolactinemia are disturbances of the menstrual cycle and galactorrhea. 3. Treatment of hyperprolactinemia without pituitary tumor is possible using CB 154. 4. In patients showing an enlarged sella turcica a selective hypophysectomy or treatment with CB 154 have to be considered carefully. 5. Suppression of postpartal lactation is achieved very effectively with CB 154.


Poly(A)-containing RNA in embryonic chick tissues.

Cytoplasmic and nuclear RNA is prepared from chick embryo skin, muscle and brain at 13 days of incubation. The concentration and labelling of RNA is measured after oligo(dT) chromatography. Skin, muscle and brain contain respectively 4.8, 3.6 and 5.6% cytoplasmic RNA with a poly(A) segment. The corresponding figures for nuclear poly(A)-containing RNA are 13, 16 and 9.4%. In skin, incorporation of [3H]uridine in RNA lacking poly(A) exceeds the rate of incorporation into muscle and brain RNA by about 2.5- and 5-fold, respectively. By contrast, no such large differences in rates of incorporation between the tissues are observed with poly(A)-containing RNA.


The conformational protential of porcine proinsulin C-peptide.

Statistical analysis of protein sequences lends itself to the identification of regions with a definite inclination to adopt specific main-chain conformations. Application of the model of Chou and Fasman[1,2] to porcine proinsulin C-peptide localizes the tendency to form a helix in the segments (38 to 44) and (51 to 58). A tendency to beta turn formation is predicted for the segment (45 to 50). The realization of this conformational potential under native and various other conditions was examined by CD spectroscopy. Synthetic C-peptide as well as the synthetic fragments (33 - 40), (41 - 52), (41 - 61), (46 - 52), (46 - 61), and (53 - 61) were included in the study. These fragments provide breaks in the amino acid sequence in each of the potentially ordered regions. The strong helical tendency in the (51 - 58) segment can be activated in the fragments (41 - 61) and (46 - 61) by 1 per cent sodium dodecylsulfate, although the spectrum is not indicative of a classical alpha-helix. However, the conformation in the (51 to 58) segment should also be non-random in native C-peptide, since cleavage of the (46 - 61) fragment into the subfragments (46 - 52) and (53 - 61) causes considerable spectral effects. Cleavage of the other potentially helical region (38 to 44) between residues 40 and 41, on the other hand, is without spectral consequences. Therefore, this segment is unlikely to be helical in native C-peptide. In the coherent C-peptide, the helix formation which can be induced by sodium dodecylsulfate in the C-terminal part is apparently inhibited by interaction with the N-terminal half of the molecule. This interaction implies that the chain is folded back on itself, which is consistent with a high probability of bets turn formation in the segment (45 to 50). The CD spectra of the fragments (41 - 52) and (46 - 52), in which the beta turn could occur, are characterized by positive ellipticity about 213 nm. The correlation of the beta turn with this type of spectrum as well as its definite location are discussed, but cannot be proved solely on CD spectroscopic grounds.


Satellite-association frequency and rDNA content of a double-satellited chromosome.

A correlation between the amount of rDNA and the frequency of participation in satellite associations is observed in a double-satellited human acrocentric chromosome.


Preparation of large numbers of uniform tracheal organ cultures for long term studies. I. Effects of serum on establishment in culture.

Rat tracheas were each sectioned into fourteen rings of equal size with a slicing device which holds evenly spaced razor blades in register. The razor blades were positioned to minimize shearing of tissues during sectioning so that there was no gross tissue disruption or cell death distant from cut edges. Hundreds of these fragments can be conveniently prepared for studies requiring replicate samples. The cultures can be established in McCoy's 5a (modified) medium with or without calf serum. Cultures grown in the presence of calf serum were compared with those grown in serum-free medium, using vital phase microscopy, transmission and scanning electron microscopy, and light microscopic autoradiography of thymidine incorporation. When there is calf serum in the medium, epithelization of the entire surface of the ring occurs rapidly with the cells flattening and migrating as a sheet of closely apposed cells. Until migration is complete, mitoses are limited to the original mucosa near the cut edge. Without calf serum, migration is slow. The cells do not flatten or become closely apposed. Mitoses appear later but are present on all areas of the surface before migration is complete. In both serum-containing and serum-free media, ciliated cells are included in the migrating population and differentiation into pseudostratified epithelium occurs on newly epithelialized surfaces. The differing pattern of mitotic activity makes culture in serum-containing media more suitable for studies of wound healing and culture in serum-free medium more useful for some cytotoxicity and carcinogenicity studies.


Comparison of diphtheria intoxication in human and nonhuman cell lines and their resistant variants.

Differences in sensitivity to diphtheria toxin of several toxin-sensitive and toxin-resistant human and non-human cell lines were compared. A method is described whereby it is possible to compare the sensitivity of one cell line with another and obtain meaningful quantitative results. Based on the concentration of toxin required to produce 50% inhibition of protein synthesis after 24 h of exposure the ID50 (24) value toxin-resistant cells were found to be 105 to 106 times more resistant to toxin than toxin-sensitive cells. There was little variation in the ID50 (24) values for cells in each of the two groups. The toxin-resistant cells used in this study, naturally resistant as well as selected variants, possess elongation factor 2 which is susceptible to inactivation by toxin. It is suggested that they are capable of activation of toxin but either cannot bind toxin or are unable to transport toxin across the plasma membrane. Protein synthesis is inhibited when these resistant cells are exposed to high concentrations of toxin. Under these conditions it is likely that enough toxin is able to bypass the block in toxin-specific entry and reach the cytosol by a second, less efficient, nonspecific mechanism to catalyze the inactivation of elongation factor 2 and inhibit protein synthesis.


Tumour-associated lymphocyte cytotoxicity superimposed on "spontaneous" cytotoxicity in melanoma patients.

Lymphocytes from 16 stage I, 6 stage II and 31 stage III melanoma patients (MP) and 51 healthy donors (HD) were tested as far as possible in parallel on a melanoma cell line (NKI-4), a bladder carcinoma cell line (T 24) and 18 different short-term melanoma cultures. Lymphocytes from MP and HD showed cytotoxic effects towards all three types of target cells. Lymphocytes from HD showed the strongest "spontaneous" cytotoxic effects on NKI-4 cells whereas, in general, weak cytotoxic effects were seen on short-term cultured melanoma cells. Within the different lymphocyte donor groups an enormous variation in cytotoxic effects was observed. However, the overall cytotoxic effects of stage I and II MP were significantly higher than those of the HD-group. Stage I MP showed significantly stronger cytotoxic effects on NKI-4 cells than on T 24 cells, indicating that tumour-associated lymphocyte cytotoxicity was superimposed on spontaneous cytotoxicity.


The effects from combining urea and an alcohol on the heat-induced reversible denaturation of ribonuclease.

The effects of a combination of an alcohol and urea on the transition temperature of bovine ribonuclease were investigated. The combined effects on the transition temperature of ribonuclease of a polyvalent alcohol and urea are about equal to the algebraic sum of the effects of each individual additive. The effects of a monovalent alcohol and urea are not cummulative, especially not at low temperatures (30 degrees C). The presence of urea decreases the hydrophobic effect of a monovalent alcohol, strongly at low temperatures, to a lesser degree at high temperatures (60 degrees C). Consequently, urea hinders the interhydrophobic interactions by affecting the water molecules.


In vivo motility of the unobstructed fallopian tube.

Current methods of recording the fallopian tube motility in vivo essentially measure the intraluminal pressure. Diametral change is another parameter which can provide additional useful information related to tubal function. A method for in vivo monitoring of diametral change without obstructing the lumen and based on the impedance measurement technique has been proposed. An in vitro comparison of wall displacement with transtubal electrical impedance change shows that the impedance changes reflect diametral changes. Another in vitro experiment in which the autorhythmicity of contractions was maintained by means of a perfusion bath indicates that the impedance changes are primarily due to the contraction of the circular muscles of the fallopian tube. These studies were followed up with long-term chronic implantations with dual probes on the isthmic and ampullar regions of the tube in female rabbits. Inpedance changes over periods as long as 6 mo could be readily obtained. Histological observations as well as fertility studies support the conclusion that the tube is minimally affected by the placement of the probes.


Growth and physical training with reference to heredity.

Identical male twins (four sets aged 10 yr, four sets aged 13 yr, and four sets aged 16 yr) were divided so that one twin underwent strenuos endurance training for 10 wk, while his brother served as a control without training. Intrapair comparisons of the training-period changes in aerobic, anaerobic, and cardiorespiratory responses to maximum work on a bicycle ergometer disclosed that 1) 10-yr-old trained twins improved more than untrained twins did in VO2max,2) 16-yr-old trained twins increased their VO2max, O2 pulse, blood lactate, ventilation, and respiratory rate and decreased their maximal heart rates more than their untrained counterparts did, and 3) the trained and the untrained 13-yr-old twins changed commensurately. Further, interage comparisons of the intrapair differences showed that both the 10- and 16-yr olds improved their VO2max more than did the 13-yr olds. In view of this evidence, the old hypothesis that more may be gained by introducing extra exercise at the time when the rate of growth is greatest is not tenable.


A simple electrolytic method for cutting small-diameter stainless steel tubing.

An electrolytic approach to cutting small-diameter stainless steel tubing is described. The method is superior to abrasion or manual methods because it produces a clear lumen in the smallest diameter tubing available. The method is simple, quick, and inexpensive and has been found valuable for making small injection needles, small tissue punches, and for repairing broken or occluded microliter syringes.


Determination of methyl mercury in fish by flameless atomic absorption spectroscopy and comparison with an acid digestion method for total mercury.

A method for the concurrent determination of methyl mercury and inorganic mercury by flameless atomic absorption spectroscopy (AAS) is described. Fifty-seven samples of juvenile black marlin fish were analyzed for inorganic and methyl mercury, and total mercury was calculated by addition of the 2 values. The sensitivity of the method was estimated to be 0.029 mug for inorganic mercury and 0.033 mug for methyl mercury. The detection limit of the method was about 0.02 mug inorganic mercury or methyl mercury and the error of the method was found not to exceed 10% for samples giving about 10% deflection on the absorbance scale. Samples from the same fish were analyzed by a commonly accepted flameless AAS method for the determination of total mercury. When the results for total mercury from the 2 methods were statistically compared, using a paired t-test, the difference between the results obtained by the 2 methods was found to be insignificant at the 95% confidence level.


Stimulation of prostaglandin biosynthesis by vasoactive substances in methylcholanthrene-transformed mouse BALB/3T3.

Prostaglandins E2 and F2alpha are present in the culture medium of methylcholanthrene-transformed mouse BALB/3T3 cells. The production of these prostaglandins is stimulated when the cells are incubated in the presence of serum, arachidonic acid, thrombin, and bradykinin, or if they are mechanically manipulated. Whereas the appearance of prostaglandins resulting from the latter four treatments is complete in several minutes, in the presence of serum the prostaglandin levels are still increasing ever after 2 hours. Stimulation by all of these treatments is additive. Indomethacin inhibits these stimulations, suggesting that the production of prostaglandins results from de novo biosynthesis.


Preparation and characterization of a dextran-trypsin conjugate.

Bovine pancreatic trypsin was coupled to dextran after activation of the polysaccharide by cyanogen bromide. The soluble dextran-trypsin conjugated was purified by molecular sieve chromatography. After coupling, 53% of the esterase activity of trypsin remained, but the conjugate had only 7% of the caseinolytic activity of the native enzyme. The modified trypsin showed greater resistance than the native enzyme to inactivation by heat treatment, autodigestion, or denaturing agents, and was also more resistant to inhibition by trypsin inhibitors, particularly ovomucoid. Treatment with dextranase partly removed the improved stability properties and resistance to inhibition of the trypsin-dextran conjugate. The conjugated enzyme preparation consists of a heterogenous mixture of macromolecular aggregates, each containing many trypsin and many dextran molecules linked together. Intramolecular cross-linking of enzyme molecules by polysaccharide chains is considered to be responsible for stabilization of the tertiary structure of the enzyme molecules in the conjugate.


Salivary epithelial cells in primary culture: characterization of their growth and functional properties.

Mouse submandibular salivary gland cells were grown in primary explant culture. After an initial period of degeneration within the explant, surviving epithelial cells proliferated rapidly and duct-like structures recolonized the explant. Autoradiographic studies showed that a peak of DNA synthesis occurred after 4 days in vitro and that proliferation was enhanced by insulin and hydrocortisone. These cells retained specialized secretory function (protease activity) for at least 2 weeks in vitro. This enzyme is a differentiated product of granular tubule cells in vivo. Between 6 and 10 days, explants attached to the substrate. An outgrowth developed, consisting largely of ultrastructurally identifiable epithelial cells which formed pseudoglandular structures in the monolayer. Epithelium survived for over 6 months in primary culture but could not be serially transferred. Secondary cultures were rapidly overgrown by mesenchymal cells.


Two ultrastructurally distinct tubulin paracrystals induced in sea-urchin eggs by vinblastine sulphate.

Two types of ultrastructurally distinct tubulin paracrystals have been induced in sea-urchin eggs with vinblastine sulphate (VLB) under different sets of conditions. One type of paracrystal appears to consist of hexagonally-close packed microtubules and closely resembles paracrystals present in mammalian cells treated with vinblastine or vincristine sulphate, but not previously reported in sea-urchin eggs. The other type is also made up of tubulin subunits, but these do not seem to have polymerized into microtubules. Both types of paracrystal are induced in sea-urchin eggs in the presence of VLB at a time when tubulin subunits would not normally polymerize. Possible mechanisms for tubulin activation and the induction of paracrystal formation are discussed in respect to the available information on the binding sites of the tubulin subunits.


The effects of mitotic inhibitors on the structure of vinblastine-induced tubulin paracrystals from sea-urchin eggs.

Vinblastine sulphate (VLB) is known to induce in vivo formation of tubulin paracrystals in sea-urchin eggs. Corresponding paracrystals have been prepared in the presence of both vinblastine sulphate and other mitoclasic agents. Careful standardization of conditions was required to restrict the formation of alternative forms of the paracrystals induced by vinblastine alone. Comparisons were made between preparations in terms of paracrystal shape, size, proportion of eggs containing paracrystals, number per egg and their relative times of first appearance. A correlation between such properties were established. Comparison of paracrystals at the ultrastructural level showed them all to be similar regardless of the drugs present during their formation. The implications of tubulin polymerization in the presence of mitoclasic agents are discussed and mechanisms for paracrystal enhancement by combinations of such drugs are suggested. Some similarities of paracrystal and microtubule seeding are discussed together with the activation of tubulin in the pool.


Comparative properties of the Charcot-Leyden crystal protein and the major basic protein from human eosinophils.

Guinea pig eosinophil granules contain a protein, the major basic protein (MBP), which accounts for more than half of the total granule protein, has a high content of arginine, and displays a remarkable tendency to form disulfide-linked aggregates. In this study we have purified a similar protein from human eosinophil granules and have compared the human MBP to the protein comprising the Charcot-Leyden crystal (CLC). Eosinophils from patients with various diseases were purified and disrupted, and the granule fraction was obtained. Examination of the granule fraction by transmission electron microscopy showed numerous typical eosinophil granules. Analyses of granule lysates by gel filtration and by polyacrylamide gel electrophoresis revealed the presence of peroxidase and MBP with properties similar to that previously found in guinea pig eosinophil granules. The human MBP had a molecular weight of 9,200, contained less than 1% carbohydrate, was rich in arginine, and readily formed disulfide-bonded aggregates. CLC were prepared from eosinophil-rich cell suspensions by homogenization in hypotonic saline. The supernates following centrifugation of cell debris spontaneously formed CLC. Analysis of CLC revealed the presence of a protein with a molecular weight of 13,000 containing 1.2% carbohydrate. The protein displayed a remarkable tendency to aggregate even in the presence of 0.2 M acetic acid. Human MBP and CLC protein differed in their molecular weights, carbohydrate compositions, and amino acid analyses. Mixtures of the MBP and the CLC protein yielded two bands in polyacrylamide gel electrophoresis. Neither eosinophil protein increased vascular permeability in the guinea pig skin or contracted the guinea pig ileum. The results indicate that the human MBP and the CLC are distinct substances with properties such that one cannot be derived from the other.


Heart-rate responses to snakes among behaviorally avoidant and nonavoidant college students.

The study assessed the extent to which heart-rate responsivity in the presence of a snake is correlated with behavioral avoidance of a snake. College students described, by a commonly used method, as either snake-avoidant or nonavoidant were exposed to a snake and to a neutral stimulus while their heart rates were monitored. Those Ss who were not behaviorally avoidant responded to the snake and to the neutral stimulus in essentially the same way. Those who were behaviorally avoidant showed less heart-rate responsivity to the neutral stimulus than to the snake. However, this difference was marginal and of insufficient magnitude to argue that snake-avoidant volunteer Ss are meaningful surrogates for clinically phobic patients. The results indict the value of dozens of previous experiments.


A comparison of hypothalamically induced biting attack with natural predatory behavior in the cat.

A comparison of biting attack induced by electrical stimulation of the cat hypothalamus with natural feline predatory attack revealed a high degree of similarity between the two behaviors. All major components of natural attack could be elicited by hypothalamic stimulation in cats not showing spontaneous attack, including stalking approach to prey, holding and pinning of the prey with forepaws, biting directed to the head and neck, prey kicking, prey carrying, and prey eating. Differences between natural and elicited attack appeared to be related to the range of completenes of elicited attack, the greater intensity of elicited attack, and the presence of unrelated responses induced by hypothalamic stimulation. Results support the view that hypothalamic stimulation facilitates sensorimotor mechanisms for separate response components, which are highly sensitive to specific stimulus features of the environment and potential goal objects.


Fermentation tubes for in vitro digestion of forages.

During in vitro digestion of forages by rumen microorganisms in polycarbonate centrifuge tubes, forage particles formed dense mats which were raised above the level of media by entrapped gas. This did not occur with polyethylene centrifuge tubes. In vitro organic matter digestion was higher in polyethylene than in poly-carbonate tubes. Vacuum infiltration of water into samples prior to inoculation increased in vitro digestion with both types of tubes but to a greater extent with samples of high than of low digestion. Regression analysis of in vivo digestibility on in vitro digestion showed that the lowest residual standard deviation was with polyethylene tubes and vacuum infiltration, but omission of vacuum infiltration gave satisfactory results.


Lactational efficiency complex of rats: provisional model for interpretation of energy balance data.

In experiments to determine maintenance requirements and partial efficiencies of conversion of diet and body tissue to milk, correlations between independent variables interfered with multiple regression procedures usually used in analyzing nutritional energetic data. Therefore, an alternative of a largely deterministic model of energy transformations in lactating rats was developed. Food intake, initial and final body weights, and diet composition were inputs to the model. These inputs were partitioned among the several metabolic functions of lactating rats within the model, and estimates of milk energy, heat increment of production, energy used for maintenance, and heat increment of maintenance were computed. The model was validated with rats and diets not used in model development. Inferences were: (a) average efficiency of body energy conversion to milk is 83%; (b) average gross and net efficiencies of milk production on balanced rations are 57 and 80%; and, (c) maintenance requirements vary as a function of food intake. A logistic function relating maintenance to food intake was developed based on the postulate that changes in intake of food cause changes in weights of several vital organs changing the maintenance requirement. This postulate explains, in part, changes in maintenance requirements during long food restriction and during gestation and lactation.


Effect of processing soybeans on their use by calves.

Full-fat soybeans processed by grinding, roasting, or heating by microwave were used to supply the protein in rations fed Holstein calves. Nitrogen digestibilities of the rations were not significantly different. Nitrogen retention for the roasted soybean ration was higher than that of raw or microwave-heated soybean rations. Nitrogen solubility of the roasted soybeans was lower than that of the other soybeans. Protein hydrolysis, as measured by a new in vitro technique, was higher for the roasted soybeans than for the raw or microwave-heated beans. There were no significant differences in the digestibilities of dry matter, ether extract, or nitrogen free extract among the three rations. Digestibility of crude fiber was lower for the roasted ration than for the other rations.


Egg substitutes: chemical and biologic evaluations.

The total lipid, cholesterol, phospholipid, and fatty acid content of dried whole egg (DWE), a refrigerated liquid egg substitute, a powdered egg substitute, and a commercial egg yolk replacer (EYR) were compared. All substitutes contained less total lipid, cholesterol, and phospholipid than DWE. The powdered substitute contained only half the total lipid content reported by the producers and only a fifth of the cholesterol of DWE, while the percentage distribution of fatty acids was similar to that of DWE. The liquid substitute and EYR had fatty acid distributions similar to soybean oil. Rat growth and lipid response were compared for diets containing either DWE or a mixture of EYR and egg white. Both diets were fed with and without vitamin and mineral supplements. Rat growth response was greatest on the DWE diets, either with or without the supplements, was intermediate on the supplemented EYR diets, and was least on the unsupplemented EYR diets. The consumption of DWE-containing diets, when compared with the EYR-containing diets, caused greater liver weight, greater liver total lipid and total cholesterol content, and slightly higher serum cholesterol.


Changes in frying fats with batters containing egg.

The effect of whole egg and egg yolk phospholipids in a fritter-type batter on changes in color, phosphorus content, percentage of free fatty acids, and NUAF fatty acid esters of a corn oil and a hydrogenated vegetable shortening used for approximately 7 hr. of frying was studied. A highly significant (P less than 0.01) increase in the percentage of free fatty acids, phosphorus content, and darkening of color in the frying fats was associated with the presence of egg or egg yolk phospholipids in the batters. NUAF fatty acid esters in the frying fats were not significantly affected by the batters being fried. These data support the suggestion that diffusion into the frying fat of phospholipids from fried batters containing egg yolk contributes to an increase in free fatty acids and a darkening of color in the frying fat.


Immunochemical study of incomplete platelet autoantibodies by the anti-globulin consumption test (AGCT) with specific anti-immunoglobulin sera.

The indirect anti-globulin consumption test (AGCT) with specific immunoglobulin antisera (anti-IgG and anti-IgM) has been applied to the immunochemical characterization of incomplete platelet auto-antibodies in 33 patients with idiophatic thrombocytopenic purpura (ITP), systemic lupus erythematosus (SLE) and autoimmune hemolytic anemia (AHA). In these cases indirect AGCT on platelets was positive with polyvalent gamma antiserum. The test with anti-IgG was positive in all cases except two, while always negative with anti-IgM, with no relation to the presence of complete platelet antibodies, the type of disease and the immunochemical type of erythrocyte autoantibodies in AHA patients. These results indicate that the incomplete platelets auto-antibodies were of the IgG class.


A prospective study of children "at risk" for deafness.

A prospective survey of 738 children with high risk factors was carried out in the north-east of Scotland. High risk factors used in previous surveys were reviewed and considered inadequate. New and stringent standards are described. Results are compared with the national incidence of sensori-neural deafness and with other surveys.


Leukemia in AKR mice. I. Effects of leukemic cells on antibody-forming potential of syngeneic and allogeneic normal cells.

Cells from the spleen, thymus, lymph node, and liver of leukemic AKR mice suppress in vitro antibody responses of normal syngeneic and semiallogeneic cells. This suppression can be mediated by irradiated leukemic cells, requires cell contact between leukemic and normal cells, and may occur at any time during the in vitro culture period. Leukemic AKR cells do not suppress antibody responses of allogeneic cells, even when allogeneic cells have H-2 or background genes homologous with AKR. Leukemic cells do, however, suppress cells that are unable to respond allogeneically to leukemic AKR cells, such as cells of the F1s of AKR. Suppression of normal AKR antibody responses by leukemic AKR cells may be overcome by addition of irradiated allogeneic cells. The fact that leukemic AKR cells are able to suppress normal lymphocyte responses may be of significance in pathogenesis of leukemia in these mice.


Adoptive suppression of granuloma formation.

Anti-egg granulomas formed in mice with chronic S. mansoni infection are smaller than those formed early (8 wk) after infection. Passive transfer of serum from mice with chronic infections to recipient mice with developing (6 wk) infections did not affect hepatic granuloma size at 8 wk of infection. In contrast, either spleen cells or lymph node cells from mice with chronic infections strongly suppressed the granulomatous process in recipient mice. Spleen cells, but not lymph node cells, of early-(7 wk) infected mice exhibited some ability to diminish granuloma formation in recipients. It appeared that the use of two sequential, weekly passive transfers of spleen or lymph node cells from chronic mice was even more effective in this suppressive capacity than a single transfer.


Residual splenic function in the presence of thorotrast-associated hepatic tumor: case report.

A 50-year-old man had received intravenous colloidal thorium dioxide (thorotrast) 27 years previously. Scintiscans with both 99mTc-sulfur colloid and 131I-rose bengal revealed an extensive intrahepatic defect. At operation, the lesion proved to be an infiltrating hemangiosarcoma. The spleen was small but the chronic internal radiation of the spleen had not completely destroyed the function of radiocolloid uptake. Review of the literature disclosed other cases in which the spleen was still capable of accumulating radiocolloid some years after thorotrast administration. In at least one other instance, radiocolloid uptake was not accompanied by splenic ability to clear Howell-Jolly bodies: a disassociation of splenic functions. The effects of the internal radiation dose to the spleen from thorotrast are discussed and compared with the effects of external radiation. The discrepancy between the effects of the two doses may be related to the high relative biologic effectiveness of the alpha rays from thorotrast compared with  gamma-radiation, to nonuniformity of distribution, and to the effects of reticuloendothelial blockade.


Cellular retinol-binding protein and retinoic acid-binding protein in rat testes: effect of retinol depletion.

Testes of rats contain two cellular binding proteins of interest in vitamin A metabolism. One protein binds retinoic acid with high specificity; the other binds retinol with high specificity. When the cellular retinol-binding protein was partially purified from rat testes, it exhibited fluorescence excitation and emission spectra similar to that of all-trans-retinol in hexane. Exposure of this preparation to UV light destroyed this fluorescence but spectra identical to the original were obtained after addition of retinol. Hexane extracts of the binding protein had fluorescence spectra identical to all-trans-retinol, suggesting that this compound is bound to the protein in vivo. Extracts of testes from retinol depleted rats were submitted to gel filtration but failed to show a retinol-like fluorescence at the elution position of retinol binding protein. This fluorescence was observed in the preparations from pair fed control animals. However, after addition of all-trans-retinol to the extracts from the depleted rats, fluorescence at that elution position was observed. This indicates that in testes of retinol depleted rats the cellular retinol binding protein is present but without bound retinol, in contrast to the non-depleted rats where 30-43% of the binding protein had bound retinol. The amounts of cellular retinol binding protein and retinoic acid binding protein in testes, as determined by sucrose gradient centrifugation, were found to be similar for retinol depleted and pair fed control rats.


Nitrogen retention in men fed varying levels of amino acids from soy protein with or without added L-methionine.

A metabolic study was undertaken to determine methionine requirements of six young men fed soy protein isolate (SB) for 9-day periods. Formula diets contained 9 g of nitrogen from intact proteins with glycine and alanine added. Nitrogen derived from intact protein was g per day: reference eggwhite (EW), 3.0, 4.5, and 6.0; and SB, 3.0, 4.5, 6.0, and 7.5. SB diets were fed with and without addition of L-methionine to raise the total amount of sulfur amino acids (SAA) to 900 mg. Mean nitrogen balance was positive with diets containing at least 4.5 g EW, 6.0 g SB, and 4.5 gSB with methionine added. Individual requirements for SAA were: for one man between 320 and 480 mg; for three, between 480 and 640 mg; for one man, between 640 and 800 mg; and for the sixth man, between 640 and 900 mg. Thus 900 mg, stipulated by the 1973 FAO/WHO Committee as being necessary for the 70 kg reference man, was sufficient for all participants. Nitrogen balance was equally improved by increasing the SB nitrogen level by 1.5 g or adding methionine at each level of SB fed.


Studies of the digestibility and retention of nitrogen and amino acids in rats fed raw or heated soy flour.

Apparent digestibility and absorption of nitrogen and amino acids from raw and heated soy flour were studied in rats. The apparent digestibility of all the amino acids from raw soybean was lower than from the heated flour. The net absorption was also significantly lower in the group fed raw soy flour for most of the amino acids, with the exception of cystine and methionine. The pattern of the amino acids along the digestive tract showed that while the levels of amino acids from heated soy flour started to decline in the jejunum and continued to decline in the ileum, in the group fed raw soy flour, the decline in levels of the amino acids did not begin until the ileum. The delay in the absorption might affect the overall absorption and utilization of the amino acids, and might explain the lower percentage retention of total nitrogen and amino acids in the carcasses of rats fed raw soy flour as compared with those fed heated soy flour. Possible reasons for the markedly lower cystine retention (relative to other amino acids) in the carcasses of the raw-soybean-fed rats are discussed.


Enzymic activities in the pancreas, digestive tract and feces of rats fed raw or heated soy flour.

Trypsin, chymotrypsin and amylase levels were determined in the pancreas, all along the intestinal tract, and in the feces of rats fed raw or heated soy flour diets. The levels of all enzymes measured in the pancreas in the non-fasted state were lower in the raw than in the heated soy flour-fed rats. Fasting equalized these levels. Trypsin and amylase tended to be lower, and chymotrypsin was significantly higher in the intestinal tracts of raw soy flour-fed rats than in the group fed heated soy flour; the greatest differences were found in the ileum. Trypsin and chymotrypsin levels in the feces were higher in the group fed raw soy flour than in the group fed heated soy flour. Amylase in the feces of the raw soy flour-fed rats was higher at the beginning of the experiment and dropped sharply to be even lower than in the heated soy flour-fed rats at days 13 to 14 of the experiment. It was concluded that measuring the enzymic levels in the feces is a very sensitive method for determining whether a test diet induces hypersecretion of digestive enzymes in rats. This method can be used from the start of feeding the experimental diet. As the animal need not be killed, the effect of the test diet upon enzymic secretion can be studied as a function of time, and it might be suitable to studies with large animals.


Anthelmintic 1-cinnamamido-2,4-imidazolidinediones.

A series of 1-(substituted cinnamamido)-2,4-imidazolidinediones has been prepared from the corresponding cinnamoyl chlorides and 1-amino-2,4-imidazolidinedione hydrochloride in pyridine. These compounds possess a significant degree of anthelmintic activity against the mouse pinworm Syphacia obvelata. The most active compounds are those substituted with halogen or cyano groups.


Cytochemical localization of endogenous peroxidase activity in renal medullary collecting tubules and papillary mucosa of the rat.

Endogenous peroxidase activity, as demonstrated by the technique of Graham and Karnovsky (Graham RC Jr, Karnovsky MJ: J Histochem Cytochem 14:291, 1966), was identified in medullary collecting tubule cells and in the cells of renal papillary mucosa of the rat. Peroxidase reactive sites were observed in the perinuclear cisterna, endoplasmic reticulum, and cytoplasmic vesicles of such cells. The specificity of the peroxidase reaction was verified by means of chemical inhibitors (NaN3, KCN, aminotriazole), denaturation of the enzyme by heat, exclusion or prior oxidation of substrate (diamino-benzidine), and high concentration of H2O2. Prolonged fixation (glutaraldehyde) improved cellular detail but diminished or abolished the peroxidase staining. When exogenous H2O2 was excluded from the incubating medium, a positive reaction was obtained suggesting that H2O2 can be endogenously generated. This observation was confirmed by degradation of tissue-formed H2O2 with beef liver catalase and by blocking endogenous generation of H2O2 with sodium pyruvate. These studies indicate that the reaction product is the result of an enzymatic reaction and that the enzyme is most likely a peroxidase. A similar staining reaction was not observed in other tubule segments, including cortical collecting tubules. The significance of this peroxidase activity is discussed in relation to the cellular localization and biosynthesis of renal medullary prostaglandins.


Paecilomyces varioti endocarditis on a prosthetic aortic valve.

Fungal endocarditis following prosthetic valve surgery has assumed increased importance as a cause of postoperative death. We present, to our knowledge, the first case of the fungus Paecilomyces varioti producing endocarditis on a prosthetic aortic valve. This seems to be an extremely indolent organism which exhibits an apparent response to antibiotic therapyl. In vitro evidence suggests that this fungus is sensitive to attainable serum levels of both 5-fluorocytosine and amphotericin B. However, after viewing the extracted valve and the devastating embolic phenomenon in our patient, we believe that medical therapy alone would not suffice. Thus we suggest that prompt valve replacement be performed in future cases.


Immunological aspects of uveitis in Bantu-speaking Negroes of South Africa.

Immunological studies in Bantu-speaking Negroes with uveitis consisted of a search of humoral antiuveal antibodies and immunologically competent cells. Using a tanned red cell hemagglutinating technique, no humoral antiuveal antibodies were detected in the blood of 87 patients nor in the aqueous of 6 patients. Lymphocyte blast transformation was negative in 80% of the patients tested and leukocyte migration inhibition positive in 75% of the patients tested. A discussion of these findings is presented.


The use of the macrophage electrophoretic mobility test for the diagnosis of eye diseases.

The MEM test by FIELD and CASPARY has been investigated for its importance in analyzing the cell-mediated immunity in ophthalmology. Sensitized lymphocytes of patients are incubated in vitro either with basic encephalitogenic protein for investigating malignoma or with various eye antigens for investigating chronic ocular diseases. The eye antigens have been fractionated by gel chromatography and identified by various immune sera. The sensitized lymphocytes are released in vitro by incubation with antigen a factor which reduces the electrophoretic mobility of guinea pig macrophages.


X-ray-induced recessive lethal mutations in the mouse.

A test of X-ray-induced recessive lethal mutations in mouse spermatogonia (500 rad) was carried out. The test was based on familial analysis, which allowed division on the P pairs into those with lethal heterozygous members and in others assumed to be lethal-free. The F1 males from the latter group, in back-crosses to their daughters, gave an excessive rate of intra-uterine death in comparison with lethal-free males. The excessive death is assumed to reflect the rate of new (induced + spontaneous) recessive lethals or rather lethal equivalents. Three ways of estimating the rate of new recessive lethal mutations gave a mean of 5.5% per genome. From the previous tests we can assume that 1% are spontaneous mutations. Thus the data indicate that the mutation rate per rad per gamete is 9 X 10(-5). This value is identical with a previous estimate. The results are discussed in relation to population tests performed in the early 60's. It is concluded that the lack of observable deterioration in the populations after several consecutive generations of exposure is in accord with the estimates in the present analysis which are more than an order of magnitude lower than assumed at the start of the population tests. It is also stressed that species with different DNA contents show similarities in point estimates of doubling dosages.


Lack of effect of sodium fluoride on a maternal repair system in Drosophila oocytes.

Three-day-old females were fed with sodium fluoride, then mated for 24 h to ring-X males that had been irradiated with 2000 R of X-rays. The effect of NaF on the recovery of sex-chromosome loss and autosomal translocations, both induced in the paternal genome, was studied. In contrast with actinomycin-D and caffeine, treatment of females with NaF produced no consistent or significant alteration in the frequency of sex-chromosome loss and translocations recovered from irradiated males. Although there was a tendency for the translocation frequency to be slightly lower in the NaF series, the difference did not reach statistical significance. The present results concerning NaF cannot support the expectation that NaF might act as an inhibitor of maternal repair in Drosophila oocytes.


Reversal of advanced digoxin intoxication with Fab fragments of digoxin-specific antibodies.

Purified Fab fragments of ovine digoxin-specific antibodies reversed severe digoxin intoxication in a patient who had taken 22.5 mg of the drug with suicidal intent. Atrioventricular block with extreme bradycardia was temporarily managed by pacing, but progressive, intractable hyperkalemia (serum potassium of 8.7 meq per liter) with increasing pacing threshold and progressive intraventricular conduction delay was controlled only after infusion of 1100 mg of Fab. Sinus rhythm returned 10 minutes after completion of Fab infusion. Within five hours, the serum potassium concentration fell to 4.0 meq per liter. Free digoxin concentrations in serum fell sharply to undetectable levels, whereas total serum digoxin concentration concomitantly increased 12-fold. Renal excretion of digoxin bound to Fab was documented. Reversal of toxicity was not accompanied by hemodynamic instability, and antibodies to sheep Fab fragments were not detected in the patient's serum after treatment. Thus, purified digoxin-specific Fab fragments are capable of rapid reversal of advanced digoxin toxicity.


Vitamin A transport in human vitamin A toxicity.

The plasma retinol transport system was studied in three patients with chronic hypervitaminosis A. The toxic state in each was associated with increased plasma concentrations of total vitamin A, and particularly of retinyl esters. The concentrations of plasma retinol-binding protein and prealbumin were, in contrast, non to retinol-binding protein. These limited clinical data support conclusions from detailed studies with hypervitaminotic rats, which suggest that vitamin A toxicity occurs when excessive amounts of vitamin A are presented to cell membranes in association with plasma lipoproteins, rather than specifically bound to retinol-binding protein. Retinol-binding protein may not only regulate the supply of retinol to tissues but also protect tissues from the surface-active properties of the vitamin.


Multiple sclerosis and childhood infections.

There is evidence that some event in childhood may determine risk of multiple sclerosis: Elevated titers to measles and other childhood infections suggest a childhood infection. Therefore, childhood infections reported by 30 patients with multiple sclerosis and matched controls were compared. Patients reported a childhood infection between 5 and 9 years (not simply exposure to an infection) more often than controls. The mean age of measles peaked somewhat later (age 7) in patients than in controls (age 4); this differnce approached statistical significance (p less than 0.1). Evidence that host response to measles is age-dependent was reviewed. It was proposed that age of measles (rather than the fact of injection) may influence the risk of developing multiple sclerosis.


"Painless" spinal epidural hematoma during anticoagulant therapy.

Severe back or radicular pain has previously been considered as the earliest and most prominent symptom in spinal epidural hematoma. In the patient described here, a "painless" spinal epidural hematoma developed during anticoagulant therapy. The absence of pain delayed recognition of the lesion and institution of therapy. The absence of pain is distinctively rare, but should not delay appropriate diagnostic procedures when other signs suggest the presence of a spinal epidural hematoma.


Horner's syndrome in childhood.

During a 36-month period, seven cases of Horner's syndrome were encountered in a general pediatric hospital. The most common site of involvement was the ipsilateral sympathetic chain, although multiple sites were involved. Several causes of Horner's syndrome in childhood that have received little previous attention are reported-internal carotid artery thrombosis, subclavian artery aneurysm, and nasopharyngeal tumor. Suggestions for routine evaluation are given. Angiography and x-rays of the temporal and sphenoid bones are valuable in the diagnosis of intracranial lesions causing Horner's syndrome. Horner's syndrome is not rare in childhood and is associated with serious underlying disease.


Calcification of the basal ganglia as a cause of levodopa-resistant parkinsonism.

We present a patient with levodopa-resistant parkinsonism due to basal ganglia calcification related to surgically-induced hypoparathyroidism. The calcification was seen on computerized axial tomography but not on skull x-rays. Such calcification should be looked for in all cases of levodopa-resistant parkinsonism, since it is possible that treatment of hypoparathyroidism may halt progression of the disease. This case with similar ones from the literature suggest that striatal disease itself can cause parkingonism and that the parkinsonism in such patients tends to be less responsive or nonresponsive to levodopa.


Localization of speech parameters by brain scan.

Speech was studied in 18 patients who had a positive radioisotope brain scan within the left hemisphere and a history of a single stroke. Seventeen patients had definite language impariment. In most cases of either fluent or nonfluent aphasia, the center of the scan was behind the central sulcus. Patients with perisylvian involvement were much more likely to have severe comprehension deficit than those without such involvement. Those patients with the most severely decreased fluency were significantly more likely than those more fluent to have markedly decreased comprehension. In an occasional patient, involvement of fluency and comprehension was divergent, suggesting that these processes may be differentially affected.


Myofibrillar incorporation of 3H (G) L-leucine in pgrogressive muscular dystrophy and motor neuron disease.

A study of the incorporation of hydrogen 3 (3H) leucine into skeletal muscle in patients with human muscular dystrophy and motor neuron disease showed uptake in cytoplasm and myofibrils. The techniques used were light and electron microscopy and autoradiography before and after glycerination (Szent-Gyorgyi). The results indicated an increase of 3H leucine uptake into cytoplasm of the dystrophic muscle and a marked drop in incorporation into structural protein. In the patients with motor neuron disease, the normal incorporation into cytoplasm was seen, with reduced uptake into structural protein. These results showed a different protein synthesis pattern in dystrophic and denervated muscle.


Prolonged and monosymptomatic dysphasic status epilepticus.

Dysphasic seizures are an infrequent form of epilepsy, and their serial appearance as a partial status epilepticus is quite exceptional. The young patient reported here had a partial dysphasic status epilepticus of 3 weeks' duration without other temporal lobe seizures. Simultaneous serial electroencephalograms, tape recordings of the seizures, and repeated neuropsychologic ictal examinations permitted studies of increased impairment of neuropsychologic function on testing and the appearance of new irritative discharges on encephalography.


Thalamic neuroaxonal dystrophy and dementia in Hodgkin's disease.

The brain of a patient with Hodgkin's disease and dementia showed numerous dystrophic axons in the thalamus. In absence of lymphomatous cellular infiltration, necrosis, hemorrhage, demyelination, neuronal loss, or infection by opportunistic organisms, the axonal dystrophy in this patient appeared to be directly related to the Hodgkin's disease itself. Moreover, dementia as a nonmetastatic complication of Hodgkin's disease may have been the result of the thalamic axonal dystrophy.


Sex-linked sudanophilic leukodystrophy with adrenocortical atrophy (so-called Schilder's disease). Report of a case and review of the literature.

We report the clinical and pathologic features of a case of sex-linked sudanophilic leukodystrophy in an 8-year-old boy. Our survey of the pertinent literature on this disease supports the current view that it is not limited to the central nervous system, but is a generalized process, probably caused by an unknown metabolic defect, with a definitive genetic pattern and varying expressions. Although the disease was originally described by Schilder as a single entity, cases like ours show that the term "sudanophilic leukodystrophy" represents a better classification than the usually misinterpreted eponym, "encephalitis periaxialis diffusa."


Pseudohypertrophic myopathy in cysticerosis.

A patient with diffuse involvement of the central nervous system and pseudohypertrophic muscular changes induced by cysticerci is described. Electromyographic and pathologic changes are reported for the first time. Electromyographic examination demonstrated numerous short-duration, low-amplitude motor unit potentials in proximal muscles. Biopsy showed swelling of muscle fibers, fiber atrophy with fibrosis, and cellular infiltration separate from inflammatory exudate surrounding numerous cysts.


Meningeal carcinomatosis. Case report and review of the literature.

Untreated meningeal carcinomatosis is a uniformly fatal type of metastatic disease presenting with many protean signs and symptoms. We achieved significant palliation and long-term survival in our patient, using combined chemotherapy and radiotherapy; responses to both intrathecal methotrexate and experimental oral CCNU were observed.


Subacute proximal diabetic neuropathy.

The results of clinical, electrophysiologic, and histologic studies in three patients with a type of diabetic peripheral neuropathy, subacute proximal diabetic neuropathy (diabetic amyotrophy), are presented. On the basis of our findings, we suggest that diabetic amyotrophy is a clinical and pathologic entity separate from mononeuritis multiplex. These patients have a generalized neuropathy, and it is postulated that disordered neuron-axonal metabolism forms the basis for the pathologic and clinical changes. Histochemical changes in the muscle biopsy showed type 1 predominance. We suggest that this phenomenon represents a conversion of surviving fibers of whatever type, to a type 1 oxidative metabolism because of the change in use of these fibers.


Parasellar and orbital apex syndrome caused by aspergillosis.

Patients with orbital aspergillosis commonly present with unilateral proptosis and associated sinus disease. However, neither of these manifestations was observed in a 62-year-old woman who had an orbital apex syndrome with visual loss, complete ophthalmoplegia, and corneal hypoesthesia. Pathologic examination of specimen from a granulomalike mass removed at left frontotemporal craniotomy showed branching hyphae with the characteristic appearance of Aspergillus.


Amitriptyline in the prophylaxis of migraine. Effectiveness and relationship of antimigraine and antidepressant effects.

Amitriptyline was evaluated as a prophylactic antimigraine agent in 110 patients with severe migraine. This agent improved the migraine more than 50 percent in 72 percent of patients and more than 80 percent in 57 percent of patients. Most of the 31 patients with less than 50 percent improvement had virtually no response. Depression, measured with the Zung Self-Rating Depression Scale, was absent in 40 patients, borderline in 53, and moderate to severe in 17. Overall, depression ratings improved minimally with therapy. There was a weak relationship between improvement in depression and improvement in migraine. Subgroups with a stronger correlation of these could not be found. This work suggests that amitriptyline is effective in migraine prophylaxis and that it has a primary effect on migraine that is relatively independent of its antidepressant action.


Paramesencephalic arachnoid cysts.

The term "paramesencephalic" is proposed to describe the location of a general class of arachnoid cysts observed in four patients. These cysts, which appear to arise within the subarachnoid space, are characterized by a lack of communication with the ventricular system. Usually, the arachnoid tissue is normal, and the cyst fluid resembles cerebrospinal fluid both macroscopically and microscopically. Hydrocephalus is variably accompanied by localizing signs. Problems may be encountered in the diagnosis of suprasellar (case 4), parapineal (case 3), incisural (case 1), and interpeduncular (cases 2 and 4) arachnoid cysts. Early surgical exploration is strongly recommended.


Abnormal lumbar isotope cisternography in an unusual case of spontaneous hypoliquorrheic headache.

The unusual case of spontaneous hypoliquorrheic headache reported here was clinically identical to that originally described by Schaltenbrand. This is the first case to be studied by radioisotope cisternography, which showed that the cerebrospinal fluid flow was essentially normal. However, the radioactivity counts percent decreased rapidly, with simultaneous appearance of high isotope concentration in the urinary bladder. Scan images did not show cerebrospinal fluid (CSF) leakage at the puncture sites. Our data suggest that this postural headache syndrome is not caused by decreased CSF production, but by a very rapid absorption or unusual CSF leakage.


Depressed ventilatory response in oculocraniosomatic neuromuscular disease.

Four patients with ptosis, external ophthalmoplegia, and ragged-red fibers on muscle biopsy were found to have decreased ventilatory responses to hypoxia and hypercapnia. Respiratory muscle weakness was not responsible for these findings since these responses were normal in muscle disease control patients. An altered metabolic state also can cause diminished ventilatory response, but overall oxygen consumption data in the ragged-red fiber patients were normal. The decreased ventilatory responses may be clinically significant because two of the ragged-red fiber patients had episodes suspicious of hypoventilation with poor response to hypoxia.


Reduplicative paramnesia.

A striking behavioral abnormality is described in three individuals who had severe head trauma. At a point when general mnestic capabilities had returned to a near normal level, the patients persistently relocated the hospital at another geographical site, even in the face of compelling counter-evidence. The strong parallels in the etiology and course of the three cases justify the positing of a syndrome, here termed reduplicative paramnesia. A neuropsychologic analysis of the disorder stresses the cognitive operations entailed in geographical localization and confabulation. Clinical-pathologic considerations underline the role of right hemisphere and frontal lobe structures in the syndrome.


Lateralization and language representation.

The hypothesis is advanced that cerebral dominance includes two elements, interhemispheric specification for language (lateralization) and intrahemispheric language, specification (localization). Consequently, each type of aphasia is determined by the degree of dominance establishment (i.e., lateralization and localization) existing at the moment of brain damage. Evidence for this concept is presented through a comparison of aphasia in left-handers and "anomalous" dextrals with aphasia in childhood.


Cinephotomicrography of dog spinal vessels during cord-damaging decompression sickness.

Thirty-three dogs were anesthetized, laminectomized in the lower thoracic, upper lumbar region, and exposed to simulated 220 ft air dives of 5 to 60 minutes. Cinephotomicrography of the epidural vertebral venous system and dorsal pial vessels was done predive and postdive. The epidural vertebral venous system became blocked by bubbles in 24 animals. Eighteen animals evaluated for clinical and/or pathologic signs of cord damage all manifested positive signs. In 10 dives made by eight dogs, epidural vertebral venous system obstruction did not occur, and signs of cord damage were absent after nine of these dives. After one dive, a dog manifested cervical cord damage remote to the region of epidural vertebral venous system under observation. Acute pulmonary hypertension and central venous congestion were not essential prerequisites for epidural vertebral venous system occlusion to occur. These experiments permit further analysis of the pathogenesis of spinal cord damage in decompression sickness.


Biochemical and histochemical studies of biogenic amines in spinal cord trauma.

Highly sensitive enzymatic assays, microdissection techniques, and histochemical methods were used to investigate the effects of blunt trauma on rabbit spinal cord serotonin, norepinephrine, and dopamine concentrations. Within 5 minutes after trauma, norepinephrine and serotonin in gray matter decreased considerably at the lesion center. In white matter, norepinephrine decreased or was unchanged, but at the lesion edges serotonin increased. No changes in dopamine concentration were detected. Substantial changes in monoamines do occur after spinal cord trauma and serotonin may play a role in injury development.


Effect of a long-acting contraceptive progestogen on lactation.

A prospective study was made on the duration of lactation in 406 mothers injected postpartum for contraception with medroxyprogesterone acetate (DMPA), 150 or 250-300 mg, IM, at 3- or 6-month intervals. Breast feedings up to 2 per day were recorded, and findings compared with those from 173 nontreated controls. Eighty percent of the DMPA group were nursing successfully at the sixth month and 42% at the 12th month postpartum. These figures are significant and compare favorably with the control group. No advantage was found in the administration of DMPA earlier than the second or third month after delivery. Amenorrhea persisted during lactation. No pathologic breast conditions were observed. The eventual mechanism of DMPA in galactopoiesis has yet to be clarified.


Effect of particle size on time course of transport of surrogate ova through the rabbit oviduct.

The time-course of transport of plastic microspheres of 100, 200, 400, 800, and 1000 mu diameter through the rabbit oviduct was studied under various hormonal conditions. During estrus, the rabbit oviduct rapidly transports particles of 200 mu diameter to the uterus. After ovulation, the passage of these particles is delayed, first at the ampullary-isthmic junction, and then along the isthmus, perhaps influenced by a second site of resistance at the uterotubal junction. Particles of 100 mu diameter are not subject to these delays but pass rapidly to the uterus. Our data support the idea that the rapid passage of 100-mu spheres reflects a size-related inability of the resisting "gates" to limit their passage. Pharmacologic doses of estrogen act to prolong or increase the resistance to particle passage at the ampullary-isthmic junction and apparently also accelerate transport through the isthmus. Progesterone presumably increases the efficiency of the "gate" at the ampullary-isthmic junction, hastens transport through the isthmus, and seems to "open the gate" at the utero-tubal junction. Further experiments are required to prove or negate these inferences.


Stress Urinary Incontinence.

Stress urinary incontinence (SUI) was studied in 125 women who were subjected to simultaneous urodynamic and radiologic evaluation. This included cystometry, urethral pressure profiles, measurement of effective urethral length, estimation of urethral mobility, and alterations in the urethrovesical angles during stress. The most common abnormality was a hypermobility of the proximal urethra with loss of its intraabdominal position during stress, associated with changes in the urethrovesical angle. Fixation of the posterior urethra, loss of effective urethral length, low resting urethral pressure, and true neurovesical dysfunction were also found in some of the patients. Uninhibited bladder contractions were found in 22% of cases, but in most instances they were the result of SUI and ceased after surgical repair.


Clostridium perfringens infection complicating chemotherapy for choriocarcinoma.

A case of Clostridium perfringens sepsis and gas gangrene complicating chemotherapy for gestational choriocarcinoma is reported. The infection was eradicated using antibiotics, surgery, and hyperbaric oxygen therapy. The pathophysiology, diagnosis, and treatment of this unusual but often lethal complication are reviewed.


[Laser trabeculopuncture. II. Screen electron mascroscopic findings].

Laser trabeculopuncture was performed on preparations of human anterior chamber angle obtained from cadaver eyes. It was possible repeatedly to make about 50 mum large openings leading from anterior chamber to Schlemm canal. It was necessary to use short exposure times of maximum 200 msec and laser efficiency of at least 1,500 mW at the origin. The results were studied with a scanning electron microscope.


Fibrin clots in the choriocapillaris and serous detachment of the retina.

Clot formation occurs preferentially in the choriocapillaris. With intraocular inflammation this clotting begins along the inner surface of the choriocapillaris suggesting that dilatation of the vessels and opening of the endothelial fenestra have initiated the process. With the systemic coagulopathy of thrombotic thrombocytopenia (TTP) and disseminated intravascular coagulopathy (DIC) clotting occurs preferentially in the submacular choriocapillaris, sometimes associated with choroidal hemorrhage and detachment of the retina. These complications are illustrated in the present paper by a patient with TTP showing relatively chronic coagulopathy and by three patients with DIC showing variations of acute coagulopathy.


[Endocardial fibroelastosis (E.F.) and its differential diagnosis].

The endocardial fibroelastosis (EFE) is the most frequent cardiomyopathy. This disease is characterised by endocardial hyperplasia due to proliferation of elastic and collagenous fibres. There are primary and secondary forms. Within the primary form, the infantile form is the most frequent and of greatest importance to the pediatrician. This form is more a syndrom than a distinct disease. It is a reaction of the endocard due to several noxes. Lately a possible viral etiology is being discussed e.g. Parotitis, Coxsackie or other viruses. Clinical criteria for diagnosis are: cardiomegaly, left ventricular hypertrophy seen in 97% in the ECG, the absence of a murmur (or a soft apical mumur) absence of cyanosis and absence of systemic disease. Differential diagnosis is mainly between fibroplastic parietal endocarditis (FPE), cardiovascular collagenosis (CC) and endomyocard fibrosis (EMF). In FPE thrombosis is frequent and typically there is eosinophilia. CC is found in South Africa and is characterised by edema and fibrinoid necrosis. MEF is present mainly in Uganda, Nigeria and South India, characterised by endocardial fibrosis, valve involvement and eosinophilia. The obstructive hypertrophic cardiomyopathy is characterised by a pronounced cardiomegaly, insufficient weight gain as well as dyspnea and cyanosis. Catheterization shows a gradient across one or both of the outflow tracts due to hypertrophic subaortic or subpulmonic stenosis. Therapy of EFE consists in treating the cardiac decompensation and according to the severity of the disease, in steroids.


[Relationship between cord blood insulin and prenatal dystrophy (author's transl)].

Cord blood Insulin of 82 newborns with different degree of prenatal dystropy was measured by radioimmunoassay. An inverse proportion of Insulin level to the degree of prenatal dystrophy was found. These data may point to a lack in stimulation of Insulin secretion caused by intrauterine malnutrition.


Experimental analysis of developing hemopoiesis in fetal bone marrow.

1. We have used fetal rats to study the following aspects of the development of hemopoiesis: (a) content of hemopoietic stem cells in fetal bone marrow, liver, and peripheral blood and (b) origin of hemopietic cells in the developing mammalian bone marrow. 2. In the studies we utilized the diffusion chamber technique to study the content of stem cells committed to granulopoiesis. The number of myelopoietic stem cells in liver peripheral blood and in "bone marrow" of 18-day-old rats is nearly identical. Since in "bone marrow" a considerable number of peripheral blood cells are present in the vessels at that time, whereas extravascular cells consist only of mesenchymal cells, one might assume that these peripheral blood cells give rise to granulocytic precursors in the cultures. Morphologically these cells are "blast" cells and lymphocytes. 3. Based on cell labeling indices of radioautograms, derived from continuous infusion of pregnant rats with [3H]thymidine, it could be shown that in the perichondral area mesenchymal cells of the fetus and newborn have a slow rate of DNA turnover whereas "bone marrow" cells are in an active state of profileration. 4. In further support of this it was also shown that injections of hydroxyurea (an agent which destroys cells in DNA synthesis) has vitrually no effect on perichondral mesenchymal cells whereas "bone marrow" cells were completely blocked in their ability to support myelopoietic differentiation in the diffusion chamber implants. 5. The conclusions would therefore be that (a) local perichondral cells, i.e., mesenchymal cells, do not contribute to marrow hemopoiesis, (b) matrix cells of the developing bone marrow cannot reconstitute hemopoiesis, and (c) hemopoietic bone marrow cells develop from migrating peripheral "stem cells", one of the sources being the liver.


Role of sodium and urea in the renal concentrating mechanism in Psammomys obesus.

Micropunctures were performed at the tip of Henle's loops and vasa recta accessible at the extrarenal surface of the papilla in a desert rodent (Psammomys obesus) studied under mild NaCl ((NaCl 4%, 0.0375 ml/min) and mild urea (urea  4%, 0.0375 ml/min) loading conditions. In Nacl loaded animals, it was confirmed that solute addition (mainly sodium) contributes in a large proportion to the concentrating process along the thin descending limb. Comparison of sodium and urea concentrations in the loops with those in vasa recta at the same level of the papilla demonstrated that 1. the transepithelial sodium gradient was compatible with a diffusion transport of this ion from the interstitium to the thin descending limb; 2. the sodium concentration higher in interstitium than in the loop fluid was not compatible with the existence of a purely passive concentrating process in inner medulla as was recently proposed [8], 3. the transepithelial urea gradient was very limited which indicates that this solute does not play an important part in the concentrating process. In urea loaded psammomys, solute addition (mainly urea) to the thin descending limb fluid was still present but water abstraction was enhanced as compared to salt loaded animals, probably on account to the higher interstitial urea concentration. It is, thus, brought to evidence that the relative contribution of water abstraction and solute addition to the concentrating process along the thin descending limb can vary in a given species as a function of the physiological state.


Taste qualities elicited by electric stimulation of single human tongue papillae.

Single human taste papillae in 5 young test subjects were electrically stimulated 84 times each with a silver wire (0.4 mm tip diameter) versus a 5 x 3.5 cm2 reference electrode on the left wrist of the subject. The electrical pulses were positive (54 papillae) or negative (45 papillae) of 0.5 msec duration and had a frequency of 50, 100, 200, 400, 600 or 800 Hertz. For control 45 papillae were merely touched by the electrode without current stimulation. Significant gustatory and tactile results (x2-test, P less than or equal to 0.05) signaled by the subjects were: a) on anodic stimulation 50 +/- 5% of the touched papillae gave overall taste responses, namely 22.2% sour, 3.8% bitter and 1.8% salty; the rest were mixed sensations. Sweet  was not reported in these final experiments; b) on cathodic stimulation 42.2 +/- 5% of the papillae responded with taste, which again were reported as 22.2% sour, 2.2% salty, the rest mixed; c) on mere touching there were hardly any gustatory sensations reported. - These results indicate only a relative specifity for each single human taste papilla and its taste fibres.


Specificity of innervation of iris musculature by sympathetic nerve fibres in tissue culture.

Irides from 3-5 day old rats have been grown 1-3 mm from superior cervical or lumbar paravertebral sympathetic ganglia in modified Rose chambers. The two muscles of the iris received distinctly different innervation patterns in vitro, and these were similar to those seen in vivo. Varicose, adrenergic fibres were consistently associated with the dilator pupillae rather than with the sphincter pupillae while excitatory, cholinergic junctions developed between the nerve fibres and the muscle cells of the spincter but not the dilator. There was a lack of specificity shown by the sympathetic neurons during this innervation. Fibres from lumbar ganglia formed plexuses within the dilator similar to those formed by superior cervical fibres, and sympathetic, cholinergic fibres were able to substitute for the normal parasympathetic, cholinergic fibres in the sphincter.


Voltage dependence of agonist responses at voltage-clamped frog endplates.

The conductance increment produced at voltage clamped frog endplates by various agonists, applied either iontophoretically or in the bath, increases exponentially with membrane hyperpolarisation, an e-fold change being obtained with shifts of the order of 100 mV. The voltage dependency of this increase is the same for different, but low, agonist concentrations. However, conductance changes evoked by decamethonium increased less with hyperpolarisation than did conductance changes evoked by carbachol or tetramethylammonium. Hyperpolarisation slowed iontophoretic responses to carbachol or decamethonium, and enhanced and prolonged inhibition of carbachol by a brief pulse of decamethonium.


Sodium chloride preference in hypertensive (H) and normotensive (N) rats.

Salt consumption was compared in two strains of rats, selected for their disparate proneness (strain "H") or resistance (strain "N") to Doca-salt hypertension. NaCl intake was similar in "H" and "N" rats prior to an following administration of Doca, while their respective blood pressures at the end of this experiment was 178 +/- 5mm Hg vs. 134 +/- 3 mm Hg. Thus, disparate responses of the blood pressure to Doca in the two strains cannot be ascribed to differences in salt intake. In another study, salt preference was tested in "H" and "N" rats by two-bottle self-selecting technique. Before Doca, saline preference in "H" rats averaged 60.3 +/- 5.8% of total daily fluid consumption, vs 18 +/- 4.2% in "N" rats. Following Doca treatment for 3 weeks the respective values were 96 +/- 1.7% vs 67 +/- 6.6%. Thus Doca treatment enhanced salt appetite in both strains, but salt preference remained significantly higher in the "H" rats. The increased susceptibility to hypertension and enhanced salt appetite in the "H" rat, corroborates similar reports in the Okamoto "SH" rat. In the Brookhaven "S" rat, however, susceptibility to hypertension is associated with salt avoidance. The conflicting data do not support a unified concept of a genetically determined link between salt appetite and proneness to hypertension.


Miniature end-plate potentials and sensitivity to acetylcholine in the fast and slow limb muscles of hibernating golden hamsters.

During hibernation reduction of frequency of the miniature end-plate potential (m.e.p.p.) was observed. This parameter was reduced in the extensor digitorum longus (EDL) muscle to 16% and in the soleus muscle to 7% of values found in awake animals. The ACh-sensitive area of the individual muscle fibres in both types of muscle increased about three times during hibernation.


Enzyme activity patterns of energy supplying metabolism in the quadriceps femoris muscle (vastus lateralis): sedentary men and physically active men of different performance levels.

1. In 3 groups of men, differing as to the amount and intensity of physical training loads, increasing in the order "sedentary": "sporting": "athletic", enzyme activities were estimated in biopsy samples of m. quadriceps femoris (vastus lateralis). The enzymes were: Hexokinase (HK), NAD: glycerol-3-phosphate dehydrogenase (GPDH), triosephosphate dehydrogenase (TPDH), lactate dehydrogenase (LDH), citrate synthase (CS), NAD: malate dehydrogenase (MDH), and 3-hydroxyacyl-CoA dehydrogenase (HOADH). Indicators of laboratory performance and whole-body metabolic capacities (maximal oxygen consumption etc.) were estimated in the "sporting" and "athletic" groups. 2. In the 2 latter groups, distinguished by greater physical activity, the atypical enzyme activity pattern, remarkable by a low activity of LDH and high relative activities of GPDH and HK, as reported earlier in a sedentary group (Bass et al., 1975a), disappeared. The possibility of the atypical low LDH enzyme activity pattern as resulting from lack of bodily exertion is discussed. 3. The moderately trained "sporting" group distinguishes itself from the "sedentary" one mainly by a higher activity of LDH and by lower activities of GPDH and MDH. In the intensively trained "athletic" group, enzymes connected to aerobic oxidation (MDH, CS, HOADH) and GPDH also show higher activities than in the "sporting" group. The difference between the two more active groups is further borne out by a higher maximum oxygen uptake and carbon dioxide release of the well-trained "athletic" group. This difference of enzyme activity pattern may not be confined to the quadriceps femoris muscle.


Nutritive and non-nutritive blood flow in canine skeletal muscle after partial microembolization.

Partial microembolization of the previously dilated gastrocnemius muscle of the dog was performed by intra-arterial injection of latex microspheres (max. diameter 50 mum). No particles larger than 10 mum were recovered from the venous blood. Blood to tissue clearance of 4-amino-antipyrine was found to decrease after microembolization, and capillary transport coefficients were disproportionately lowered in comparison with the observed decrease of total blood flow. Venous oxygen saturation increased despite decreasing total blood flow in the working muscle after microembolization. The data indicate a shift of blood flow from nutritive to functionally non-nutritive channels.


Method for simultaneous determination of red cell and plasma flow velocity in vitro and in vivo.

A method is described which can be used to simultaneously determine the flow velocity of plasma and of red blood cells in small glass tubes in vitro or in living microvessels of the microcirculation. The principle of dual slit photometry is applied to the measurement of plasma flow by determining the passage time of a dye bolus across two photodetectors separated by a variable distance. Measurements performed both in vitro and in vivo indicate a significant difference (up to 85%) between cellular and plasmatic flow velocity.


The mechanism of coronary hyperemia induced by increased cardiac work.

The interrelation between coronary flow, heart work, coronary venous pO2, and tissue contents of energy-rich phosphates were studied in isolated guinea pig hearts performing external work. Within the range studied, energy-rich phosphates were dependent on left ventricular output, but not on arterial pO2. At constant arterial pO2, changes in coronary flow were associated with changes in energy-rich phosphates, but not systematically with changes in coronary venous pO2. Simultaneous increases in ventricular output and arterial pO2 resulted in increased coronary flow even though coronary venous pO2 rose. It is concluded that work-induced coronary dilation may occur independently on a decrease in coronary venous pO2. The possibility that energy-rich phosphates might be linked with a non-hypoxic dilation mechanism is discussed.