Energetics of amino acid transport into brain slices: effects of glucose depletion and substitution of Krebs' cycle intermediates.

Amino acid uptake by slices of brain is greatly diminished by incubation of the slices in glucose-free media. Uptake can be restored by the addition of a number of substrates, e.g., lactate, citrate, or oxaloacetate. The mixture of succinate, malate, and pyruvate (SMP, 20, 5, and mM) restored amino acid uptake better than glucose after brain slices were incubated in glucose-free media to deplete endogenous energy stores. The degree of restoration of uptake was different with the various amino acid transport classes and was independent of the restoration of ATP levels in the tissue. After restoration of uptake with SMP the amino acid uptake was resistant to NaF, but was markedly more sensitive to arsenite and oligomycin. The results indicate the coupling of mitochondrial energy transducing systems to transport.


Maintenance of neurons isolated in bulk from rat brain: incorporation of radiolabeled substrates.

Neurons isolated in bulk from 10- to 15-day-old rat brain can be maintained for 18--24 h. Phase microscopy shows that the cells remain morphologically intact during this time. As a criterion of viability, the incorporation of radiolabeled amino acids and uridine into trichloroacetic acid-insoluble material was selected. The cells are capable of the incorporation both after isolation and after maintenance. The uptake is constant with time, is proportional to substrate concentration, and is inhibited by puromycin and cycloheximide, but not by chloramphenicol. Thus the cells remain viable during this maintenance period. This system may provide a model for the study of the synthesis of specific neuronal components.


Phasic gain control of reflexes from the dorsum of the paw during spinal locomotion.

In chronic spinal cats walking with their hindlimbs on a treadmill belt, tactile stimuli were applied to the dorsum of the paw during various phases of the step cycle. A stimulation during the swing phase evoked a flexion response with a concomitant crossed extension, whereas in stance it induced an increased ipsilateral extension. EMG-recordings show short latency reflex responses in flexors and extensors, respectively. The responses are organized such that latencies of knee muscles are shorter than those of ankle and hip muscles. The movements induced by the stimulations appear to be very meaningful during normal conditions in compensating for any unpredicted obstacle disturbing the movement of the paw during locomotion. Responses during forward flexion and during the support phase are well adapted to the ongoing locomotor activity and do not influence the interlimb coordination whereas a stimulation when the foot approaches the ground after the end of flexion disturbs the regular alternating pattern. Different possible mechanisms underlying this phase-dependent reflex reversal are discussed.


Denervation in the primary olfactory pathway of mice. IV. Biochemical and morphological evidence for neuronal replacement following nerve section.

Unilateral olfactory nerve section was performed in the mouse. Three biochemical markers of the olfactory chemoreceptor neurons: carnosine, carnosine synthetase activity and the olfactory marker protein, were measured in the olfactory bulb and epithelium. Parallel observations were made by light microscopy as well as at the ultrastructural level. The specific biochemical markers decrease rapidly in both bulb and epithelium and reach a minimum by the end of the first week after surgery. They then slowly return to 80% of control values by one month. Carnosinase activity in epithelium was essentially unaffected. These biochemical observations coincide temporally with the onset of degenerative changes seen morphologically, in both the bulb and epithelium. The degenerative changes persist for up to two weeks in the bulb and for about one week in the epithelium. At this time basal cell division and differentiation begins in the epithelium with subsequent regrowth of olfactory axons into the glomerular layer of the olfactory bulb with ther reappearance of olfactory axon terminals. The temporal coincidence of these biochemical and morphological observations suggests they are manifestations of the same process, and is consistent with the idea that the olfactory chemoreceptor neurons are perhaps unique in being able to be replaced from undifferentiated stem cells.


A new major projection from locus coeruleus: the main source of noradrenergic nerve terminals in the ventral and dorsal columns of the spinal cord.

Almost all catecholamine (CA)-containing nerve terminals in the ventral column, intermediate grey and ventral half of the dorsal column disappeared after bilateral stereotaxic lesions of nucleus locus coeruleus, as revealed by fluorescence histochemistry. Some of the CA nerve terminals in the dorsal half of the column seemed to be unaffected by the lesions, as well as the CA terminals innervating the thoracic sympathetic lateral column and the band of nerve terminals crossing the midline and innervating the central grey. This coeruleo-spinal pathway in the rat is located in the anterior funiculus and the ventral parts of the lateral funiculus. A schematic map of the different CA projections to the spinal cord is presented. It was concluded that locus coeruleus innervates almost all parts of the central nervous system.


An autoradiographic study of the formation of the lateral motor column in the chick embryo.

An autoradiographic determination of the time of origin of the lateral motor columns (LMC) of the chick embryo has been made. The first motor neurons of the brachial LMC are born at stage 15; the earliest birthdates of lumbar LMC neurons are at stage 17. At least 95% of the motor neurons of both brachial and lumbar columns are produced by stage 23 (4 days). The remaining 5% of the motor neurons are produced during the next two days. A clear rostrocaudal gradient of motor neuron production is seen beoth between the brachial and lumbar LMCs and within the LMCs themselves. The LMCs are assembled in a mediolateral sequence: the early-born motor neurons settle medially, the later-born motor neurons settle more laterally. Observations were made of other large early-born neurons which remain permanently in the dorsal gray of the spinal cord.


A fluorescent histochemical study of changes in noradrenergic neurons following experimental cerebral infarction in the rat.

Following surgical ligation of the middle cerebral artery in the rat, central catecholamine containing neurons were studied using the glyoxylic acid histochemical technique. By 5 days after the ischemic lesion, the density of fluorescent varicosities decreased in both uninjured cerebral cortex and the cerebellar cortex and the intensity of fluorescence of somata in the ipsilateral and contralateral locus coeruleus decreased as compared with controls. At 20 days afer lesioning, catecholamine containing neurons looked normal under fluorescence microscopic examination, except fine varicose fluorescent axons were present for the first time among the cellular debris of the lesion and appeared to have sprouted into the lesion site. However, by 40 days after surgery, there was a marked increase in the density of fluorescent varicosities in the uninjured ipsilateral cerebral cortex, in the contralateral cerebral cortex, and in the cerebellum. These observations confirm the view that an ischemic cortical lesion can lead to profound changes in cetecholamine containing neurons in distant areas of the brain which are uninjured by the local infarction.


The effects of neonatal androgenization on the in vivo transport of alpha-aminoisobutyric acid into specific regions of the rat brain.

The purpose of the present study was to determine if the administration of testosterone propionate (TP) to neonatal rats is followed in vivo by alterations in the transport of the non-metabolizable amino acid, alpha-aminoisobutyric acid  (AIB), into specific regions of the brain. Forty-eigh hours after birth, male and female rats were injected s.c. with either 1,25 mg TP or an equivalent volume of vehicle. Five, 10 and 17 days after birth, control and TP-treated rats were decapitated at intervals of 2, 5, 60 and 300 min after the i.p. injection of 0.25 muCi [1-14C]alpha-aminoisobutyric acid/g body weight. Twelve brain regions, i.e., amygdala, cerebellum, corpora quadrigemina, frontal cortex, hypothalamus, medulla, occipital cortex, olfactory bulbs, olfactory tubercles, parietal cortex, pons, pyriform cortex and samples of serum were analyzed in terms of disint./min/mg tissue and as tissue/serum (T/S) ratios. At the end of 300 min there was a significant increase in the active transport of AIB in all brain regions of the 5-days-old TP-treated rats. Similarly, by 300 min, the active transport of AIB was significantly increased in all brain regions sxcept cerebellum and pons of the 10-day-old TP-treated rats. The administration of TP to neonatal rats did not alter the accumulation and/or active transport of AIB in brain regions of the 17-day-old rat at any of the tested intervals. These data indicate that (1) neonatally administered TP enhanced (either directly or indirectly) the transport and/or accumuation of AIB in specific brain regions of 5- and 10-day-old rats and (2) the effectiveness of the steroid decreased with the age of the rat.


Usefulness of an animal behavioral model in studying the duration of action of LSD and the onset and duration of tolerance to LSD in the cat.

LSD elicits a number of emergent behaviors in the cat, including limb flicking, abortive grooming, investigatory and hallucinatory-like behaviors, which we have proposed as an animal behavior model for studying the actions of LSD and related hallucinogens. These emergent behaviors were used in the present study to investigate the duration of action of LSD, as well as the onset and duration of tolerance. A dose of 10 microgram/kg of LSD produced significant behavioral changes for up to 4h, while a dose or 50 microgram/kg produced changes lasting for at least 8 h. Tolerance to a test dose of 50 microgram/kg of LSD is virtually complete one day after a single 50 microgram/kg dose, and lasts for approximately 5 days. Tolerance to a test dose of 50 microgram/kh of LSD one day after a single dose of 10 microgram/kg is quite marked, and lasts for approximately 3 days. A significant tolerance to a test dose of 50 microgram/kg of LSD occurs within 2 h after a single injection of 10 microgram/kg. The limb flick was found to be the most sensitive index in all tests: it showed the longest time-course, as well as the most rapid and longest-lasting tolerance. These studies demonstrate that the LSD-induced behavioral syndrome in the cat parallels important parameters of the action of LSD in humans, and thus enhances the usefulness of the model.


The substrate attached material synthesized by clonal cell lines of nerve, glia, and muscle.

A large number of clonal cell lines were examined for the deposition of proteins (substrate attached material, SAM) on the substratum of culture dishes. Of the many cell types examined, only nerve, muscle, and glia synthesized SAM containing a predominant species of protein with a apparent molecular weight of 55,000. This 55,000 molecular weight protein is distinguishable from actin, tubulin, and collagen.


A retino-pulvinar projection in the cat.

Injections of tritiated amino acids were made in one eye of Siamese and common cats including young kittens. After survival periods of 1--7 days axoplasmically transported label accumulated in a portion of the pulvinar nucleus as well as in the other known sites of termination of the retinofugal pathway. The retino-pulvinar projection is present at birth; it is bilateral and approximately symmetrical in common cats but the ipsilateral component is markedly reduced in Siamese animals. Labeled terminal ramifications of the retinal fibers in the pulvinar take the form of a thin, interrupted sheet oriented dorsoventrally and lying at the extreme lateral edge of the pulvinar nucleus. It appears to be continuous caudally with the medial interlaminar nucleus of the lateral geniculate complex, but the cells about which the grains cluster are clearly different from those of the medial interlaminar nucleus.


Spontaneous elimination of nerve terminals from the endplates of developing skeletal myofibers.

The development of the motor innervation of a skeletal muscle was examined in the soleus muscles of young rats. At 11 days after birth, nearly three-quarters of the endplates of individual myofibers were innervated by more than one silver stained axon. Four days later, only about 9% of the endplates remained innervated by two or more terminals. The dramatic reduction in the number of axon terminals appeared to result in large measure from the retraction of all but one of the multiple terminals. An axon interpreted as undergoing retraction was characterized by a terminal oval enlargement believed to be the site of disassembly of the fiber.


The latent period of the Limulus lateral eye receptor potential: action of chlorobutanol.

Excised lateral eye retinular cells of Limulus polyphemus exposed to chlorobutanol were examined using microelectrode techniques. The effects observed were: (1) a marked shortening of the receptor potential latent period; (2) a decrease in the effective input resistance of retinular cells to hyperpolariziog currents; and (3) a reduction in magnitude of retinular cell receptor and membrane potential. The magnitude of the changes were concentration dependent and reversible and were only produced by chlorobutanol and closely related compounds. Chlorobutanol does not alter the sodium permeability of the receptor cell membrane but it may increase the rate of the process or processes occurring during the latent period of the receptor potential.


A new view of the structural relationship between LSD and mescaline.

An examination of the effects of S-(-) and R-(+) 2-amino-1,2,3,4-tetrahydronaphthalene (2-AT) on mouse spontaneous activity and rabbit EEG has shown that the S-(-) enantiomer shows selective central effects similar to those of hallucinogens like mescaline. A stereochemical analysis of these results indicates that the structural relationship between mescaline, or other phenethylamine type hallucinogens, may involve correspondence between the aromatic ring of the phenethylamines and the pyrrole portion of the indole nucleus in LSD.


Hypothalamic self-stimulation and operant activity in the mottled mutant mouse.

Some behavioural effects of the mottled mutation were studied in the variegated heterozygote female. In mutants, compared to normals, operant activity was increased, whereas hypothalamic self-stimulation was always decreased. These results are discussed relative to the excepted central catecholaminergic disturbances resulting from the mutant gene.


Disruption of the conditioned emotional response by caudate nucleus stimulation.

The effectiveness of two forms of caudate nuclear stimulation in disrupting the development of a conditioned emotional response (CER) in rats was investigated. When a 5-sec train of 2/sec light flashes was used as a conditioned stimulus (CS), single pulse caudate stimulation delivered 100 msec after each light flash effectively retarded acquisition of the CER. Posttrial caudate stimulation (delivered after the CS--US pairing) was less effective. The differential effectiveness of these two forms of stimulation in disrupting acquisition processes was most clearly seen during extinction of the CER. The group which received caudate stimulation during the CS extinguished faster than the group receiving caudate stimulation after the CS--US pairing. A nonstimulated control group was the fastest to acquire, and the slowest to extinguish the CER.


delta9-tetrahydrocannabinol and the hippocampus: effects on CA1 field potentials in rats.

The effects of delta9-tetrahydrocannabinol (THC) on ortho- and antidromically elicited CA1 field potentials were observed in locally anesthetized rats and in anesthetized with urethane. THC augmented amplitudes of population EPSP's as well as orthodromic and antidromic population spikes from pyramidal cells in locally anesthetized animals. Latencies to peak amplitude of these response were increased. Conditioning-test shock experiments revealed taht THC also depressed recurrent inhibition probably mediated by basket cells. In animals under urethane anesthesia THC enhanced test responses, but failed to augment population response to the conditioning stimulus. It was concluded that THC enhanced postsynaptic excitatory processes but attenuated recurrent inhibition. Urethane anesthesia completely blocked the postsynaptic excitatory effect of THC but had little apparent influence on THC's disinhibitory action.


Locus coeruleus-to-dorsal raphe input examined by electrophysiological and morphological methods.

In order to examine the hypothesis that the locus coeruleus (LC) projects directly to the nucleus raphe dorsalis (DR), electrical stimulation was applied to the LC of rats while recording from single neurons in the region of the DR. Slow firing units of the DR were not influenced by the stimulation, although faster firing units in the nearby substantia grisea centralis (SGC) were. These latter cells become oscillatory in their firing rates during LC stimulation. In parallel studies a retrograde transport technique was imployed to obtain morphological evidence regarding projections to DR. Placements of horseradish peroxidase precisely in the DR resulted in very sparse labeling in the LC, although positive transport occurred to other areas. The results indicate that the LC does not project directly to slow firing DR neurons, but does influence faster firing celles in the region of the SGC, probably by complex routes. Suggestions are made for the integration of these findings with earlier fluorescence studies.


Changes in polymorphic gene frequencies in strains of chickens selected for resistance to Marek's disease.

Resistance to Marek's disease (MD) was selected over five generations in three strains and their four substrains. 2. MD mortality decreased consistently on natural exposure, but in birds artificially inoculated the mortality increased again in later generations. 3. Changes of gene frequencies at five polymorphic loci--blood group A, B and D, plasma esterase and alkaline phosphatase loci--were examined. 4. The frequencies of blood group A6 and B8 alleles showed a consistent trend of increase and the B11 allele gradually decreased in most strains. The Akp allele of alkaline phosphatase increased significantly in two of seven strains. 5. Comparisons of homozygotes and heterozygotes revealed a significant difference only at the A locus.


Effects of obesity induced by overfeeding on body temperature, the testis and plasma testosterone of the male Japanese quail.

Male Japanese quail, force-fed for 4 weeks, showed a marked increase in weight resulting mainly from the deposition of fat. 2. Obesity, induced by forced feeding, was accompanied by increases in colonic temperature (about 0-3 degrees C), peripheral leg temperature (about 3 degrees C) and by a decrease of the mid-scapular skin temperature (about 0-6 degrees C). 3. Testicular weight decreased by 30% during the period of overfeeding and the spermatozoa concentration in the testis and ducti deferentes decreased by 50%. There was also a small increase in the cholesterol concentration of the testis; testicular cholesterol concentration was negatively correlated with testicular weight. 4. A marked decrease in the concentration of the plasma testosterone was accompanied by regression of the tail and by a reduction in the volume of cloacal foam secreted.


Biochemical, physiological and production indices related to fat metabolism in the laying fowl at various stages of physiological development.

The significance of fat accumulation during physiological development of layers was studied using White Leghorn X Australorp pullets from 12 weeks of age. 2. Liver fat, carcass fat, liver weight and body weight increased markedly at the onset of sexual maturity. 3. Within the liver, the protein to DNA ratio did not alter significantly during development; glycogen was not consistently depleted by egg production. 4. Liver fat content was significantly correlated with carcass fat, liver weight and DNA concentration, and plasma total lipid and cholesterol, independent of stage of development; with body weight, liver protein, moisture, and protein to DNA ratio, excluding the period prior to commencement of sexual maturation; and with plasma phospholipid during lay. 5. Obesity was a feature of faster growing fowls which matured earlier, consumed more, utilised food less efficiently for egg production and produced fewer saleable eggs.


Ultrastructure of fibroblasts from the comb of the cockerel.

Fibroblasts in the intermediate layer of comb dermis of intact single combed White Leghorn cocks and testosterone-injected capons, all 82 days of age, were divided into three types, namely A, B and C, according to the ultrastructure of these cells. All the fibroblasts in the same tissue from capons were type C. 2. The Golgi complex and the rough endoplasmic reticulum were well developed in type A and type B fibroblasts. The latter organelle in type A fibroblasts was in the form of long parallel cisternae spaced a uniform distance apart, while that in type B fibroblasts was extremely distended, branched and anastomosed, containing flocculent material in the cisternae. In type C fibroblasts, both the Golgi complex and the rough endoplasmic reticulum were poor.


Studies on the avian shell gland during egg formation: aqueous and electrolytic composition of the mucosa.

The intracellular composition of the avian shell gland mucosa was studied at six stages of egg formation. 2. Total water content of the mucosa before shell calcification was 4-8 kg/kg dry weight (dw) and rose to 6-6 kg/kg dw during shell formation; 60% of the increase was intracellular and 40% extracellular. 3. The potassium concentration of the mucosa remained constant during egg formation. 4. Chloride was removed constantly from the mucosal cells during egg formation. 5. A model was constructed for the glandular cells which depicts them as primarily NaHCO3-secreting cells towards the luminal side and HCl-secreting cells towards the serosal side, their main function being to provide CO2/3- for shell formation. In this model, the columnar mucosal cells are responsible for the calcium used in shell formation.


The in vivo estimation of body fat content in laying hens.

A comparison was made between the determined water space of 16 laying hens weighing between 1-1 and 3-5 kg and that predicted from tritiated water space, with the object of estimating body fat content. 2. The predicted water space over-estimated the determined water space by 15%, but body fat content in living hens with fat levels representing 8-6 and 39% of carcass weight could be predicted with a coefficient of variation of 14%.


The activity of avian rhodanese.

A survey of rhodanese activity (thiosulphate: cyanide sulphur transferase) in the tissues of the domestic fowl revealed that the highest activity occurred in the kidney, approximately twice that in the liver, 316 and 141 mumol SCN formed/min g protein, respectively. 2. In sparrows, pigeons and ducks, liver and kidney activities tended to be similar and increased with body size. 3. Relationships were found between enzyme activity and body weight to a fractional power, indicating relatively higher activity in smaller birds.


The relative importance of light and temperature as phase setting signals for oviposition in the fowl.

Under continuous lighting, time of oviposition was controlled by a temperature cycle (12 h at 30 degrees C and 12 h at 20 degrees C). The peak of egg laying occurred 15 h after the beginning of the cool period, which is the same interval as the interval observed between lights-out and peak egg laying under a 12L:12D lighting schedule. 2. When the temperature cycle was set 12 h out of phase with a light-dark cycle (12L:12D; temperature reduced when the lights came on), oviposition was entrained by the light-dark cycle. 3. When a temperature cycle was set 6 h in advance or 6 h in arrears of a 12L:12D cycle there was a difference of 1-4 h in mean time of lay between the two treatments, indicating that temperature can have a significant, though subsidiary, effect on oviposition time in the presence of a clear light-dark signal. 4. When the light-dark signal was reduced to 22L:2D, oviposition time was controlled by the temperature cycle. With 20L:4D oviposition time was determined principally by the photoperiod, but with a subsidiary effect due to temperature.


Possible route of antigen uptake by the Harderian gland of the domestic fowl.

India ink and colloidal gold dropped on to the eyeball of chickens travelled up the secretory duct to reach the Harderian gland. 2. It is suggested that this is the route by which exogenous antigens reach the gland.


A comparison of the energy and nitrogen metabolism of broilers selected for increased growth rate, food consumption and conversion of food to gain.

Calorimetric measurements were made on 5-week-old male chickens sampled from the third generation of three lines selected for either increased live-weight gain (W), food consumption (F), or food conversion efficiency (E). A control line (C) was also measured. 2. Food intake and food conversion ratio were greater (P less than 0-05) in the F line than in the E anc C lines. 3. Metabolisability of the diet was 0-8% higher in the E line than in the other lines. 4. Metabolisable energy (ME) intake and heat production were greater (P less than 0-05) in the F line than in the E and C lines, and energy balance was greater (P less than 0-05) in the F than in the W and E lines. 5. During starvation, excreta energy and heat production were greater (P less than 0-05) in the F than the other lines. 6. Availability of ME (net energy) was the same (85%) for all lines but calculated daily maintenance energy requirements (kJ ME/kgW) were W, 860; F, 937; E, 796 and C, 810. 7. By 9 weeks the F line contained more fat and less water than lines E and C.


Involvement of molybdenum in feather growth.

A poor hatchability syndrome, characterised by a high incidence of weak chickens, with clubbed down and long ginger hairs, in commercial broiler breeding stock was investigated. 2. If the weak chick were given a single oral treatment of ammonium molybdate (40 microgram Mo/chick at 1 d), there was a reduction in subsequent mortality in both sexes and an increase in the growth rate of feathers in males, but not in females.


The relative growth of internal organs in light and heavy breeds.

The relative weights of the gastro-intestinal segments and of some other internal organs from light and heavy breed chicks from hatching to 21 days of age were compared. 2. The relative weight of the duodenum and jejunum was higher in the light breed than in the heavy one, the reverse relationship was found for the ileum and caecum.  3. The relative growth of the pancreas, heart, cerebrum and cerebellum was greater in the light breed.


Prevalence of Eimeria acervulina, Eimeria necatrix, Eimeria brunetti and Eimeria tenella in Georgia (USA) as demonstrated by immunity challenge techniques.

Eimeria acervulina, E. necatrix, E. brunetti and E. tenella were found to be widely distributed in north-east Georgia. 2. Using immunity challenge techniques 17 flocks from 12 to 72 weeks of age showed significantly lower lesion scores for the first three species compared with susceptible control flocks similarly challenged. Only one flock was found to be susceptible to E. tenella. No mortality occurred in the field flocks after challenge while 20 to 60% mortality occurred in the susceptible controls. 3. Partial immunity occurred more frequently in field flocks aged 28 weeks of age or less (62%) than in older flocks (30%). Lesion scores ranged from 0-1 to 2-2 with the former and 0-1 to 0-6 with the latter group. 4. A modification of the immunity challenge method was developed using lesion scores as the major criterion determining immunity. The method permits testing of four species infecting different parts of the digestive tract in one group of birds.


Bone water.

A short review is given of the water in bone. Various analyses of bone water content are discussed, and its possible location is considered in relation to the behaviour of water in isolated components of bone. Some of the difficulties encountered in examining such microscopic phenomena as water structure in a heterogeneous system such as bone are also discussed.


Changes in amino-acid composition of developing rat incisor enamel.

The amino-acid composition and total "protein" content of enamel particles dissected serially from the developing enamel of rat incisors have been determined. Changes in protein content and amino-acid composition occurred throughout all stages of development. The most obvious alterations occurred in the vicinity of a white opaque band. Here, protein was lost most rapidly and considerable changes in amino-acid composition occurred.


Proteins of the periodontium. Characterization of the insoluble collagens of bovine dental cementum.

Cyanogen bromide (CNBr) peptides were prepared of the insoluble collagen of bovine dental cementum. Following chromatographic separation, the peptides were identified by their amino-acid composition. Type I collagen ([alpha1(I)]2alpha2) accounted for more than 90% of the organic matrix, while Type III collagen ([alpha1(III)]3) was present at a level of approximately 5%. Amino-acid analyses revealed that the CNBr peptides from alpha1(I) and alpha2 chains of cementum closely resembled the corresponding peptides from calf skin. The only systematic difference was a higher level of hydroxylation of prolyl and lysyl residues of the cementum peptides.


The presence and distribution of glycogen particles in chondrogenic cells of the tibiotarsal anlage of developing chick embryos.

The distribution and localization of glycogen particles in mesenchymal cells, chondroblasts and in young, hypertrophic and degenerating chondrocytes of the tibiotarsal anlage of developing chick embryos were examined ultrastructurally using the periodic acid--thiocarbohydrazide--silver proteinate. The distribution of glycogen particles increased with the degree of differentiation and maturation of the chondrogenic cells. Mesenchymal cells showed minimal content of glycogen particles which gradually increased in the chondroblasts. The young chondrocytes further showed increased glycogen particle content compared to chondroblasts. This content reached a maximum level in hypertrophic chondrocytes. This level subsided in degenerating chondrocytes which showed a much reduced distribution of glycogen particles compared to hypertrophic chondrocytes. The morphological nature of glycogen particles depended on the degree of cellular differentiation. Both mesenchymal cells and chondroblasts contained single particles, while the glycogen particles of chondrocytes aggregated and formed a series of interconnected particles.


Calcium deficiency, pregnancy, and lactation in rats. Microscopic and microradiographic observations on bones.

Adult female rats were subjected to a calcium-depriving regimen (calcium-deficient diet containing oxalate + pregnancy + lactation) to obtain maximum bone mineral mobilization in as short a time as possible. The femur and tibia were investigated by histological, microradiographic and fluorescent microscopic methods. The regimen caused osteoporosis, which varied in severity with the degree of calcium deprivation. Most of the bone tissue removed was taken from the metaphyseal trabeculae and from the endosteal surface of the diaphysis. The remaining bone tissue seemed unchanged. The cells responsible for the bone removal did not seem to be multinucleated osteoclasts, but mononuclear, hypertrophied, elongated cells, possibly derived from the "resting" osteoblasts normally lining the bony surfaces. No signs of osteocytic osteolysis were observed. Bone formation was reduced, but present even in the most calcium-deprived animals. No increase in the amount of osteoid was observed.


Absorption spectra of bone.

Absorption spectra of human bone and its two major constituents (collagen and apatite) were obtained in the wavelength region extending from 2000 to 12,000 A. In the last two cases a minimum transmission (maximum absorption) was uniformly observed in the ultraviolet region. The two samples after exposure to ultraviolet radiations show a shift in the peak positions. Absorption peaks in the total bone spectra are not reproducible in its two constituents. After exposure to UV radiations the position of maximum absorption is displaced. A possible interpretation of the observed results is presented.


Movement of 125I albumin and 125I polyvinylpyrrolidone through bone tissue fluid.

The passage of tissue fluid through cortical bone has been investigated using radioactively labelled macromolecules as markers. The results suggest that in the cortex of young rabbit femur the movement of tissue fluid is in the same net direction as blood, mainly from the endosteal to the periosteal surface. Some albumin is incorporated from extravascular tissue fluid into calcified matrix at sites of bone formation. Polyvinylpyrrolidone, average molecular weight 35,000, is able to pass through extravascular tissue fluid in bone but is not incorporated into calcified matrix. In rabbits made vitamin D deficient, much less alblmin is retained in regions of bone formation than is the case with controls. Albumin adsorbs to the surface of calcium phosphate precipitates and it is suggested that this mechanism may be mainly responsible for its incorporation into bone.


Biosynthesis of matrix vesicles in epiphyseal cartilage. I. In vivo incorporation of 32P orthophosphate into phospholipids of chondroxyte, membrane, and matrix vesicle fractions.

The in vivo metabolism of 32P orthophosphate into phospholipids of chondroxyte, matrix vesicle, and membrane fractions of chicken epiphyseal cartilage has been studied. Incorporation of radioactive phosphate into the total phospholipid fraction of matrix vesicles was rapid, the labeling of phosphatidylcholine and lysophosphatidylserine being even more rapid in matrix vesicles than in chondrocytes. These findings indicate that matrix vesicles are formed by a rapid, metabolically active process, and are not remnants of dead cells, as had previously been postulated by some workers. The rate of incorporation of 32P orthophosphate into phosphatidylserine and sphingomyelin of matrix vesicles was significantly slower than that of phosphatidylcholine and certain other vesicle phospholipids. These findings are paradoxical because, compared with chondrocytes, matrix vesicles were enriched in phosphatidylserine and sphingomyelin and depleted in phosphatidylcholine. These results indicate that in vesicle formation the rates of degradation of the various phospholipid classes must be markedly different: phosphatidylcholine must be degraded much more rapidly than either phosphatidylserine or sphingomyelin. Support for this comes from previous data which revealed that substantial phospholipase activity is present in epiphyseal cartilage, especially in the zone of hypertrophy where matrix vesicle formation appears to be particularly active.


The measurement of blood flow in mouse femur and its correlation with 239Pu deposition.

The concentration of 18F was measured in three parts of the femur and in the blood of 36 mice killed at intervals of from 1 min to 2 h after intravenous injection. Blood supply to the bone sections, calculated by dividing the increase in 18F concentration in bone by the integral of 18F concentration in blood between selected time intervals, was shown to be unaffected by the return of 18F from bone to blood at times earlier than 90 min following injection. The supply of blood per unit mass of bone was greatest in distal end of the femur, less in proximal end and least in shaft. In whole femur average blood flow was 230 mm3 per gram fresh bone per min. The deposition of 239Pu in three parts of the mouse femur was shown to be linearly related to blood flow and the nature of the relationship is discussed.


A preliminary characterization of human cementum collagen.

Human teeth were used to obtain cementum. Collagen could not be significantly solubilized from the cementum by salt and acetic acid extraction or by pepsin digestion. CNBr digestion (86%) of cementum and subsequent carboxymethyl cellulose chromatography suggests that human cementum consists of type I collagen only as identified by amino acid and hexose analyses.


The effects of various diphosphonates on a rat model of cardiac calciphylaxis.

Seven diphosphonate analogs were treated for their effects on myocardial and cardiovascular degeneration and calcification in an experimental model of cardiac calciphylaxis. A single oral dose of dihydrotachysterol (DHT) administered to rats induced myocardial and vascular degeneration, focal myocarditis and vasculitis, and myocardial and vascular mineralization. The results demonstrated a considerable variation among the various diphosphonates in their ability to block the pathological changes observed in this model. Ethane-1-hydroxy-1,1-diphosphonate (EHDP) was the most effective diphosphonate in reducing myocardial and vascular degeneration and calcification, whereas diphosphonates such as ethane-1-amino-1,1-diphosphonate (EADP) and hydroxymethylene diphosphonate (HMDP) had little or no effect compared to saline controls. For those diphosphonates which were effective, e.g., EHDP, the tissue-protective effects were observed whether the rats were treated with drug prior to the administration of DHT, or whether drug treatment commenced after DHT administration. The results are discussed in terms of the known biological properties of the diphosphonate drugs.


The reversibility of disuse osteoporosis. Studies of bone density, bone formation, and cell proliferation in bone tissue.

One hind leg of 80 adult rats of the Sprague-Dawley strain was made osteoporotic by immobilization for 9 weeks. Osteoporosis was noted in both the femur and the tibia when the hydrated gross bone density and the bone surface areas were measured. No signs of reversibility were observed during 10 weeks after the period of immobilization. Tetracycline and DCAF labelling failed to show significant signs of increased bone formation during the 10 weeks after remobilization. At the moment of remobilization and for some weeks thereafter, there were signs of depressed mitotic activity in the bone cells when expressed as the 3H-thymidine/DNA ratio. The conclusion was that neither the cell-proliferation rate nor the cellular activity increases sufficiently for restitution of the disuse osteoporosis.


Reduction of hypoxic pulmonary vasoconstriction by diethyl ether in the isolated perfused cat lung: the effect of acidosis and alkalosis.

Hypoxic pulmonary vasoconstriction is a protective mechanism diverting pulmonary blood flow away from hypoxic areas toward more optimally oxygenated lung units. Venous admixture is reduced and arterial oxygenation improved. Hypoxic pulmonary vasoconstriction was demonstrated during acidosis, alkalosis and normal pH in the isolated perfused cat lung under conditions of constant flow and constant left atrial and airway pressures. Two per cent diethyl ether markedly reduced hypoxic vasoconstriction under all acid-base conditions, the hypoxic pressor response returning after wash-out of diethyl ether. Modification of hypoxic pulmonary vasoconstriction during acid-base disturbances and possible implications of concurrent anaesthetic administration are discussed.


The direct effects of circulating lidocaine on uterine blood flow and foetal well-being in the pregnant ewe.

We infused lidocaine intravenously into 13 pregnant ewes at a rate sufficient to maintain plasma levels between 2-4 mugm/ml, which are those commonly seen with regional anaesthesia. These levels did not change maternal blood pressure, pulse rate, cardiac output, stroke volume, total peripheral resistance, uterine blood flow or intra-amniotic pressure. Foetal blood pressure and pulse rate remained stable as did both maternal and foetal blood gases and acid-base values.


Meperidine-halothane interaction in dogs.

We studied the interaction of meperidine and halothane in 24 unmedicated, spontaneously breathing dogs. Intramuscular (i.m.) injections of meperidine, 2.75 mg/kg, 5.5 mg/kg and 11.0 mg/kg reduced the minimal alveolar concentration (MAC) of halothane required for anaesthesia. The magnitude and duration of MAC depression were dose related. Plasma meperidine concentrations following an i.m. injection of 2.75 mg/kg were lower in the awake, unsedated dogs than in the dogs anaesthetized with halothane.


Focal contracture following injection of succinylcholine in patients with peripheral nerve injury.

Focal muscle contracture in the limb following sytemic administration of depolarizing neuromuscular blocking agents have been demonstrated experimentally with transection or crush injury of the nerve, but has rarely been observed clinically in patients with partial peripheral nerve injury. Three cases of spastic response in the hand and wrist are described in patients with subclinical chronic, subacute, and acute nerve injury, to document the occurrence of this phenomenon under various circumstances.


Simple deep hypothermia for open heart surgery in infancy.

Results of open cardiac surgery under deep simple hypothermia in 121 infants with body weight of less than 10 kg are reported. Deep ether anaesthesia combined with large quantities of ganglion blocking agents (triflupromazine 3 mg/kg) constitutes the anaesthetic management of choice for deep surface-induced hypothermia. The mean lowest oesophageal temperature was 20.8 degrees C, and 18.9 degrees C rectally. The mean circulatory arrest time was 40 minutes. Seventeen infants (14.0 per cent) died post-operatively. There were no operative deaths attributable to failure of cardiac resuscitation. This technique widens the scope of open heart surgery in small infants. Most of the surgically correctable malformations should be operable by this method. More than the potential hazards of hypothermia, which we believe are solved by our technique, the major problem posed by surgery in these small infants is the trans and post-operative respiratory management.


The effects of propanidid on arterial pressure, pulse rate, preganglionic sympathetic activity and barostatic reflexes in the cat.

We have studied the effects of propanidid on preganglionic cervical sympathetic nervous activity, arterial pressure, pulse rate and barostatic reflexes of the cat. Normal, hypertensive, baroreceptor denervated and decerebrate animals with sectioned vagal nerves were studied. On the basis of our findings it is concluded that propanidid exerts its depressant action on the cardiovascular system directly. Central circulatory control mechanisms are essentially unaffected. The depression of arterial pressure caused by propanidid is moderated by two compensatory mechanisms: normal barostatic reflexes causing an increased sympathetic tone in response to hypotension and a vagolytic action of propanidid.


Malignant hyperthermia and althesin.

General anaesthesia with Althesin was administered on two occasions to a patient who was identified as susceptible to malignant hyperthermia, in whom there was identified familial subclinical myopathy and once in another patient suffering from arthrogryposis multiplex congenita with a history of fever associated with two previous anaesthetics. In the first patient halothane was administered by accident in association with the Althesin, but no hyperpyrexia occurred. In the second instance nitrous oxide-oxygen and halothane were associated purposely with Althesin. In none of these cases was there any rise in temperature, muscle rigor or elevation of the serum CPK level. This experience corroborates the experimental evidence of Hall, et al.10 and Harrison, who reported that Althesin prevented the onset of hyperthermia, and the clinical reports of Page and Judelman. Althesin can be assumed to be an effective anaesthetic for malignant hyperthermia susceptible patients.


A kinetic analysis of the processive enzyme Lactobacillus plantarum exoribonuclease.

Oligonucleotide chains consisting of adenosine residues and ranging from 1 to 70 residues in length have been tested as substrates or inhibitors with Lactobacillus plantarum exoribonuclease (EC3.1.4.20). The kinetic constants V, Km, and Ki are all chain-length dependent. Ki decreases with increasing chain length to a minimum for oligonucleotides seven residues in length and then begins to increase slightly. Kinetic plots indicate that the oligonucleotides are almost all competitive inhibitors of poly A hydrolysis. However, the oligonucleotide (Ap)3A greater than p probably leads to mixed inhibition. The enzyme is unable to retain its processivity when it hydrolyzes short oligonucleotides such as (Ap)2A and (Ap)3A. It is proposed that L. plantarum exoribonuclease possesses seven binding sites for the polynucleotide. When the enzyme is bound to a long-chain-length substrate the complex is stabilized by a binding energy of about 8 Kcal/mol. After cleavage of the terminal nucleotide the remaining binding energy is still sufficient to maintain an enzyme-substrate complex. The shortened nucleotide chain is moved relative to the enzyme to re-form the seven-bond association by a gradient of energy of about 1.7 Kcal/mol for the change from six to seven bonds.


The biosynthesis of isopimpinellin.

Bergapten and xanthotoxin, labelling in the methyl group wich carbon-14 or tritiated at three skeletal carbons, were administered to leaves of Heracleum lanatum and to cell cultures of Ruta graveolens. In all experiments xanthotoxin was the more efficient precursor of isopimpinellin, although bergapten was always incorporated to a measurable extent. Double-labelling experiments showed that both precursors, especially bergapten, underwent considerable demethylation (and presumably remethylation) before conversion to isopimpinellin. 5-Hydroxyxanthotoxin and 8-hydroxybergapten were both O-methylated by cell-free extracts of Ruta cells to isopimpinellin, in reactions mediated by discrete O-methyltransferases. 8-Hydroxy[Me-14C]bergapten was converted with a high degree of incorporation to isopimpinellin by Ruta cells in vivo, and it is suggested that the preference for the pathway via xanthotoxin may be due to more rapid hydroxylation of this substrate.


Comparative study of rye and thymus histones: amino acid analysis and tryptic fingerprinting.

Amino acid composition and tryptic fingerprints of rye (Secal cereale) H1, H2B (PH1), and H2A(PHII) histones indicate the presence of major differences between these and the corresponding calf or rabbit fractions. In addition to variations for other amino acids, fraction H1 from rye contains twice as much arginine as the corresponding animal fraction; the plant H2B (PHI) and H2A (PHII) histones show lysine to arginine ratios greater than those of their animal counterparts. The tryptic maps of the same proteins appear to differ between plants and animals by the number and the general pattern of the peptides, as well as by the quantity and distribution of the arginine-containing peptides. Such results suggest the presence of differences in the primary structure of the calf and rye lysine-rich and moderately lysine-rich histones. Furthermore, the possibility is ruled out that each of these plant histones consists of an animal-like protein with an additional segment of 20--30 amino acid residues. On the other hand, the rye and calf arginine-rich fractions H3 and H4 show similar amino acid compositions and tryptic peptides maps.


A thermal denaturation study of chromatin and nuclease-produced chromatin fragments.

Calf thymus chromatin and nuclease-produced chromatin fragments have been examined by thermal denaturation measurements. Native chromatin gave a series of distinct melting transitions at 64, 73,79, and 85 degrees C in 0.25 mM EDTA pH8. Treatments such as dialysis, mechanical shearing, or sulfhydryl oxidation of histone H3 carried out on native chromatin significantly altered the derivative melting profiles by blurring the distinct transitions and shifting the highest melting transition to a lower temperature. Derivative melting profiles for electrophoretically purified chromatin fragments, monomer through hexamer, all resembled that obtained from dialyzed chromatin. These results suggest that higher order structures exist in chromatin that are easily disrupted. Since the products of micrococcal nuclease (EC3.1.4.7) digestion of the altered chromatins did not exhibit any major electrophoretic differences from those obtained from nuclei, than most likely the primary arrangements of histones along the DNA are the main determinant for cleavage sites.


Human pituitary thyrotropin. The primary structure of the alpha and beta subunits.

The amino acid sequence of the alpha and beta subunits of human pituitary thyrotropin has been proposed based on the data derived from the tryptic and chymotryptic peptides. The alpha subunit consists of 89 amino acid residues with two carbohydrate moieties, presumably linked to asparagines in position 49 and 75, and its amino acid sequence is identical to that of lutropin alpha. The beta subunit has 112 residues with a single carbohydrate moiety attached to asparagine at position 23. Comparison of the primary structure of human thyrotropin beta with that of the bovine hormone reveals that only 11 residue positions have been found to be different.


The effect of some phenylethanolamine N-methyltransferase inhibitors on the adrenaline content in the domestic fowl diencephalon.

The concentration of adrenaline in the domestic fowl diencephalon was determined by a mass spectrometric or fluorimetric method. The values obtained were 701 and 803 ng/g, respectively. The administration of phenylethanolamine N-methyltransferase (PNMT) (EC 2.1.1.28) inhibitors (SK&F 7698 or SK&F 64139)  to the domestic fowl produced a marked reduction in the diencephalic noradrenaline methylation (from 25% in the controls ot 7--8% in the PNMT-inhibitor-treated animals); the large decrease in adrenaline concentration (to 14--18% of controls) was accompanied by a moderate decrease in noradrenaline concentration (to 63--84% of controls). Reserpine, in contrast, produced a marked reduction of both adrenaline and noradrenaline (to 12 and 17% of controls, respectively) but did not affect the percentage of methylation. It would seem a reasonable assumption that in the domestic fowl diencephalon, adrenaline is formed by N-methylation of noradrenaline and functions there as a transmitter in some specific adrenergic neuronal pathways.


Evidence for 16beta-hydroxylation of estrogens by guinea pig liver slices.

In an earlier communication, we conclusively proved that estrone-3-sulfate could be hydroxylated in the 16alpha position by guinea pig liver slices. Disulfates of 16alpha-hydroxyestrone and estriol were identified. Suggestive evidence for 6-hydroxylated metabolites was also mentioned. A careful reinvestigation has now shown that the steroid disulfate fraction is composed of 16alpha- and 16beta-hydroxylated steroids. 16beta-Hydroxyestrone in particular is an important quantitative metabolite of estradiol-17 beta. It is concluded that no firm evidence is available for the formation of 6-hydroxysteroids in the tissue system under consideration.


Competitive inhibition of catechol O-methyltransferase by RO-4-4602.

RO-4-4602, a peripheral L-DOPA decarboxylase (EC 4.1.1.28) inhibitor was shown to also inhibit the activity of catechol O-methyltransferase (COMT) (EC 2.1.1.6). Kinetic study indicated that the inhibition is of a competitive nature. The apparent Ki values of 7 X 10(6), 5.3 X 10(-6, and 9 X 10-6) M calculated from Lineweaver-Burke plots when dopamine, norepinephrine, and epinephrine, respectively, were used as substrate, showed that this drug is the most potent inhibitor of COMT yet known.


A method for the simultaneous estimation of free and ketosidically bound sialic acids.

Various methods for the estimation of free and ketosidically bound sialic acid were investigated for accuracy and specificity. It was found that oxidation with 0.025 M sodium metaperiodate in pH 7.0 phosphate buffer at room temperature for 20 min provided a simple, rapid, sensitive method whereby both the free and the ketosidically bound acid present in a mixture could be quantitatively analyzed. On completion of the oxidation step, the bound sialic acid is estimated with resorcinol reagent and the free sialic acid with thiobarbituric acid reagent. Oxidation under these conditions permitted a facile analysis of mixtures of bovine submaxillary mucin and free N-acetylneuraminic acid, whereas the Warren thiobarbituric acid procedure gave an erroneous value for free sialic acid.


Metabolism of monoamines and diamines in hyperthyroid and hypothyroid rats.

The in vivo rates of catabolism of 14C-labelled pentylamine, ethylamine, putrescine, and cadaverine were studied in thyroidectomized rats and others made hyperthyroid by the daily administration of 0.2 mg of L-thyroxine per kilogram for 20--21 days. Hyperthyroid rats metabolized the monoamines at an accelerated rate; thyroidectomized animals oxidized pentylamine at a reduced rate. There was no effect of hypophysectomy on the rate of pentylamine oxidation. The in vitro monoamine oxidase (MAO) activity of liver was reduced in hyperthyroid rats and unchanged in those thyroidectomized; MAO activity in skeletal muscle was increased in the hyperthyroid rats and decreased in the hypothyroid rats. Because of the large mass of skeletal muscle compared with liver, it is considered that the changes in muscle MAO could play an important role in determining the rate of oxidation of pentylamine in vivo. The oxidation of the two diamines tested was not significantly affected by thyroidectomy; the rates were increased in the hyperthyroid rats, but the increase was significant only for cadaverine.


Circular dichroism of turnip peroxidases.

Circular dichroic (CD) spectra of two turnip isoperoxidases, P1 and P7, and of their derivatives were measured over the wavelength range of 200 to 650 nm. For the two isoenzymes, it was observed that although the visible and Soret bands are located at similar wavelengths, their ellipticities are different. These results suggest that the active sites are similar but that differences do exist. The results are compared with those reported for Japanese radish peroxidase a and horseradish peroxidase. It appears that a common property of plant peroxidases is the presence of negative CD Soret bands for the reduced forms and their inversion upon cyanide binding. The CD spectra in the far UV region indicate an appreciable helical content for both native enzymes and their various derivatives. The calculated contents of unordered structure are very high (greater than 50% for either P1 or P7), in agreement with other studies on glycoproteins.


Wheat embryo ribonucleates. VIII. The presence of 7-methylguanosine 'cap structures' in the RNA of imbibing wheat embryos.

1. By imbibing wheat embryos in media that contain methyl-labelled methionine, it is possible to label both terminal and nonterminal 7-methylguanosine constituents in NaCl-insoluble (2.5 M, 0 degrees C) RNA (iRNA). 2. Most of the 7-[Me-14C]methylguanosine in wheat embryo i[Me-14C]RNA is present in nonterminal positions of polynucleotide chains, probably in ribosomal RNA. 3. By passage through a column of oligo-dT-cellulose, it is possible, to show that most of the 7-[Me-3H]methylguanosine in a 'bound' fraction of i[Me-3]RNA from imbibing wheat embryos is present in terminal 'cap' structures, probably in messenger RNA. 4. Although most of the 7-[Me-3H]methylguanosine in the 'unbound' (to oligo-dT-cellulose) fraction of i[Me-3H]RNA was present in nonterminal positions, there was also a highly significant fraction of 7-[Me-3H]methylguanosine in terminal 'cap' structures. Although it will be a subject of continued investigation, possible reasons why a large fraction of the total 7-[Me-3H]-methylguanosine was present in the 'unbound' fraction, in this present study, are a subject of discussion. 5. Careful analysis failed to reveal the presence of any N6,O2'-di[Me-3H]methyladenosine in the 'unbound' fraction of i[Me-3H]RNA. 6. Factors that might influence the binding of 'cap' oligonucleotides to DEAE-cellulose are the subject of a brief discussion.


The diguanosine nucleotides: do they exist in aquatic fungi?

The aquatic fungi Achlya ambisexualis and Blastocladiella emersonii were grown in the presence of 32Pi and the 32P-labeled acid-soluble nucleotide fractions were analyzed by ion-exchange chromatography on DEAE-cellulose. Selected column fractions containing diguanosine tri- and tetra-phosphates (Gp3G and Gp4G) added as chromatographic  markers were analyzed further for 32P by chromatography and (or) enzyme hydrolysis. The results of these experiments clearly indicate that neither Gp4G nor Gp3G is synthesized during vegetative growth of these organisms and cast doubt on the hypothesis that diguanosine nucleotides are important metabolic regulators in fungi.


Identification of specific phosphoproteins in nuclease-digested chromatin subunits.

Rat liver chromatin subunits (nucleosomes), which were isolated from nuclease-digested chromatin either treated or not treated with 0.5% sodium deoxycholate and 5% Triton X-100, were found to be similar with regard to sedimentation at 11 S and appeared as spherical particles with a diameter of about 100 A (1 A = 0.1 nm) in electron micrographs. The ratio of histone to nonhistone chromatin proteins (NHCP) in these subunits was 1:0.1 in the absence of detergents and 1:0.25 in the presence of detergents. After ultracentrifugation of the nuclease-digested chromatin in a 5--30% sucrose density gradient two groups of phenol-soluble NHCP were identified, one being released in the top of the gradient (fA) and the other still bound to the chromatin subunits after the nuclease digestion (fB). Two specific phosphoproteins were found in fA, one (A4) with molecular weight (MW) 39 000, pI 5.3--6.0, and the other (A5) with MW 31 000, pI 5.1--5.8. These proteins were not present in fB. Another protein in fB (B2) was highly phosphorylated, with MW 68 000, PI 6.5--8.2, and this was not found in fA. These phosphoproteins were further characterized and found to contain phosphoserine. The presence of specific phosphorylated protein(s) in fB suggests that the interaction of phosphoproteins with DNA in the eukaryotic genome is more than a random process.


Altered amounts of hemoglobin synthesis in livers of dystrophic hamsters.

In liver supernatants similar amounts of leucine are incorporated into proteins of normal and dystrophic hamsters. However, using a dual labeling technique, a protein fraction is detected which shows different levels of leucine incorporation between normal and dystrophic animals in an age-dependent fashion. The major protein in this fraction comigrates with hemoglobin or its subunits under various conditions of polyacrylamide gel electrophoresis. In animals younger than 3 days there is more synthesis of this protein fraction in dystrophic animals, while at 6 days there is considerably less synthesis of this protein. These changes are paralleled by differences in the number of erythroid foci in histological sections of the livers. There is no evidence for structurally altered hemoglobin in dystrophic hamsters. The significance of this finding and its possible relation to the dystrophy process are not known at present.


The isolation of polyribosomes from plant material using magnesium precipitation in the presence of heparin.

A procedure is described for the isolation of polyribosomes from crude tissue homogenates of germinated pea seeds using Mg2+ precipitation in the presence of the ribonuclease inhibitor heparin. Collection of the polyribosomal pellet does not require the use of an ultracentrifuge. The method has a potentially wide application for polyribosome and messenger ribonucleoprotein isolation and might also be useful where conventional techniques have failed.


Phosphonolipids. XXVII. Synthesis of phosphonic acid analogs of saturated and unsaturated L-alpha-lecithins.

A procedure for the synthesis of saturated and unsaturated phosphonolecithin from the cadmium chloride complex of sn-glycerol-3-(2-trimethylammoniumethyl)-phosphonate is reported. The phosphonolecithins are obtained by acylating sn-glycerol-3(2-trimethylammoniumethyl)-phosphonate-cadmium chloride complex with fatty acid chloride and pyridine at low temperature. The preparation of the disteraroyl, dipalmitoyl, dimyristoly, and dioleoyl phosphonolecithins by this procedure is described.


Induction of mutations by chemicals and gamma rays in mutants of yeast refractory to UV-mutagenesis.

Radiation-sensitive mutants of Schizosaccharomyces pombe, known to be refractory to UV-mutagenesis, were tested for mutability caused by treatments with chemicals and gamma rays. One such mutant (rad3) was studied over a wide range of UV doses to compare the kinetics of its mutational response to that of the wild type. All such comparisons were carried out using a forward mutation system. Data show that, unlike UV, the chemical mutagens as well as gamma rays produced mutations (although at reduced frequency), in the strains of S. pombe tested, indicating the existence of an additional mechanism(s) for chemical and gamma ray induced mutations. These observations are discussed as these relate to the pathways for repair of mutational damage in yeast.


Epiblepharon in Labrador.

We describe the characteristic configuration of normal Inuit (Eskimo) eyelids. Exaggeration of some normal features of the lower lid can result in epiblepharon inferior. We have seen in Labrador seven patients with epiblepharon of a degree sufficient to require surgical intervention. All were Inuit or had distant Eskimo ancestry. We outline their clinical features and the technique of operation which has been evolved. The results were good. We stress the importance of making the distinction between entropion and epiblepharn because the operative treatments of the two conditions are different. The recommended surgical methods include, for some cases, excision of bulky orbicularis muscle as well as skin.


Epi-macular holes: a cause of decreased vision in the elderly.

The development of epi-macular holes in the elderly represent a maculopathy which resembles senile macular hole and surface wrinkling retinopathy. Clinically it is most likely a sub-type of surface wrinkling retinopathy in which a hole forms in the epi-macular membranes. The findings in 11 patients with this condition are described.


Clindamycin in the treatment of human ocular toxoplasmosis.

Clindamycin was used systemically and periocularly to treat six patients with ocular toxoplasmosis who had a total of eight attacks. Although it appeared to quiet the attack promptly, several side effects were noted. Transient diplopia occured after large periocular doses and papillitis resulted from retrobulbar administration. Despite its efficacy, the results do not seem to warrant high systemic doses for prolonged periods in view of its systemic toxicity. Clindamycin may be most useful as a periocular injection in moderate dosage. A controlled double-blind study is needed.


The investigation of epiphora.

The investigation and management of a patient with a tearing problem demands evaluation of the lacrimal passages by syringing and intubation macrodacryocystography with subtraction prints. Data regarding function can be provided by a nuclear lacrimal scan and computer assisted scintillography. We describe our experience with 163 patients.


The use of the "lateral canthal sling" in ectropion repair.

We describe the use of the "lateral canthal sling" in the treatment of non-cicatrical "senile" ectropion of the lower lid. Combined with a resection of the lower retractors and the hypertrophied palpebral conjunctiva we consider it the treatment of choice for repairing non-cicatrical "marginal" ectropion. We offer a theory of the pathogenesis of the latter.


A Goldmann perimeter with high luminance chromatic targets.

We have modified the original Goldmann perimeter by replacing the source and shutter by a Xenon arc source with maximum target luminance of 3183 cdm-2, and a quartz iodine lamp yielding maximum background luminance of 150 cdm-2, both measured at the bowl. Colorimetric and spectrophotometric specifications of the new colour targets are comparable to the original, but give luminance intensities equivalent to 318 cdm-2: levels only realized for the white target in the original system. Chromatic profiles are comparable to previous profiles for achromatic targets and the close correspondence between the retinal threshold gradients produced by the two methods simplifies comparison of data obtained with out instrument with those obtained from routine static perimetry. Under high luminance conditions we do not find the relative foveal scotoma for blue targets observed by other researchers. The use of photometrically equated targets well withi; the photopic levels is an improvement on present methods of colour perimetry.


Tensile strength of fascia lata sutures following gamma radiation.

Gamma radiation (Co-60) is used to sterilize biological sutures. We wished to compare the effect of gamma-radiation in doses of 2.7 and 4.0 Mrads on the tensile strength of human fascia lata sutures obtained from the same cadaver. Five variables of tensile strength viz. Breaking Elongation, Breaking Load, Yield Point Load, Work of Rupture and Elastic Stiffness were determined for each suture. For Breaking Elongation the mean strength for the 4.0 Mrad dose was 3% less than for 2.7 Mrad dose (P less than 0.05); for Breaking Load 11% less (P less than 0.01); for Yield Point Load 9% less (P less than 0.02); for Work of Rupture 14% less (P less than 0.01); and for Elastic Stiffness 8% less (P less than 0.02). Irradiation with 4.0 Mrads, does not greatly change the tensile strength characteristics of fascia lata sutures.


Ultimate tensile strength of gamma irradiated human scleral sutures.

Scleral sutures were prepared by hand from the equatorial region of 53 paired donor eyes. The weakening produced by two doses of gamma Co-60 radiation (2.7 and 4.0 Mrads) was compared using measurements of tensile strength; the strength of unirradiated scleral sutures was also measured, for comparison. The three variables of tensile strength, viz. Breaking Elongation, Breaking Load, and Work of Rupture was determined for each suture. As compared to unirradiated sutures, Breaking Elongation decreased on irradiation (P less than 0.01), but the two doses of irradiation were not statistically significant (P greater than 0.05); Breaking Load increased on irradiation (P less than 0.01), but the two doses of irradiation were again not significant (P greater than 0.05). Only 4.0 Mrads irradiated scleral sutures, as compared to unirradiated ones, showed a statistically significant reduction (P less than 0.01) for Work of Rupture. No definite relationships were found by regression analysis among the tensile strength variables and the independent variables of sex and various storage times for the 4.0 Mrad data. Work of Rupture showed a negative relationship to the age of donors, though the change with age was small.


Computed tomography of choroidal melanoma and scleral buckle.

In the investigation of a patient with choroidal melanoma in one eye and repaired rhegmatogenous retinal detachment in the other, a C.T. scan demonstrated the tumour in the right globe and the encircling silastic sponge around the left globe. These radiologic findings were confirmed on histological examination of the right eye. We believe C.T. scanning may be a valuable technique for investigating bulbar and para-bulbar soft tissue abnormalities.


Uveal melanoma presenting as post-traumatic choroidal hemorrhage and panophthalmitis.

A 63-year-old Caucasian man presented with loss of vision in one eye. The loss of vision was considered to be due to a post-traumatic intraocular hemorrhage. He developed panophthalmitis 3 months later and necrosis in a malignant melanoma was diagnosed. The diagnosis of melanoma in patients with blind eyes and opaque ocular media is discussed.


Ultrasonography and 32P test in the diagnosis of choroidal melanoma with massive vitreous hemorrhage.

A malignant melanoma of the choroid presented with a massive vitreous hemorrhage which prevented any view of the posterior pole. The diagnosis was confirmed by the results of a radioactive phosphorus test and ultrasonography. In eyes with opaque media, these tests will ofter prevent delays in diagnosis.


IgE in limbal conjunctiva in Mooren's ulcer.

A patient with a severe, progressive Mooren's ulcer was unsuccessfully treated by limbal conjunctival resection and cryotherapy. The excised conjunctiva demonstrated a band of IgE along the basement membrane.


Recent advances the investigation of proptosis.

Clincal assessment of the patient presenting with proptosis determines the investigations required to make the diagnosis.


Effects of certain cations on the formation and infectivity of Phytophthora zoospores. 2. Effects of copper, boron, cobalt, manganese, molybdenum, and zinc ions.

The effects of copper, boron, cobalt, manganese, molybdenum, and zinc on the production of zoosporangia by P. cinnamomi and P. drechsleri in the presence of favourable concentrations of calcium, magnesium, potassium, and iron were investigated. Copper ions were the most effective in reducing the numbers of zoosporangia formed by both fungal species. Molybdenum was also slightly inhibitory. Total inhibition of mycelial growth occurred between 1 and 5 X 10(-5) M Cu2+ whereas total inhibition of sporangial formation occurred between 1 and 5 X 10(-7) M Cu2+. At copper concentrations between 10(-5) M and 5 X 10(-7) M, many P. drechsleri zoosporangia were abnormal in appearance and nonviable. Infection of eucalypt cotyledons by P. drechsleri zoospores was inhibited by 10(-6) M Cu2+ but this inhibition was reversed by EDTA (10(-4) M). There was no evidence for interaction between Cu2+ and Ca2+, Mg2+, K+, or Fe2+ present in the solutions used in the axenic production of zoospores. Preliminary pot trials indicated that CuSO4 had a protective action for safflower seedlings to infection by P. drechsleri when CuSO4 was applied as a dilute solution over the infection period.


Synchronous sporulation during idiophase development in surface cultures of Rhizopus arrhizus (Fischer).

A method to obtain synchronous sporulation during idiophase development in liquid surface cultures of Rhizopus arrhizus Fischer in described and evaluated for use in studying metabolism associated with asexual sporulation. In this system growth and sporulation are effectively separated. The respiratory pattern indicates three metabolic phases. The first is associated with spore germination; the second, trophophase, with growth; and the third, idiophase, with sporulation. Synchronous sporulation and the occurrence of distinct metabolic phases are taken as indications of fairly uniform cell development in the surface cultures. A photographic method of estimating large numbers of fruiting structures on semisolid medium is also described.


Symbiotic effectiveness of antibiotic-resistant mutants of fast- and slow-growing strains of Rhizobium nodulating Lotus species.

Mutants resistant ot 16 individual antibiotics were isolated from two fast-growing and two slow-growing strains of Lotus rhizobia and their symbiotic effectiveness on Lotus pedunculatus evaluated. Resistance to streptomycin, spectinomycin, chloramphenicol, and tetracycline (inhibitors of protein synthesis) was associated with little or no loss of effectiveness with all four strains but resistance to nalidixic acid and rifampicin (inhibitors of nucleic acid synthesis), and to D-cycloserine, novobiocin, and penicillin (inhibitors of cell wall-cell membrane synthesis) was associated with significant loss of effectiveness in 20-100% of the mutants. Resistance to viomycin, neomycin, kanamycin, and vibramycin was associated with loss of effectiveness with mutants of the two fast-growing strains but not with mutants of the two slow-growing strains. When tested on four alternate host legumes individual mutants of a slow-growing strain showed significantly different levels of effectiveness. The results suggest that both the inherent characteristics of the bacterium and of the host plant will influence the symbiotic effectiveness of antibiotic-resistant mutants of Rhizobium.


Cryopreservation of aster yellows agent in whole leafhoppers.

Aster yellows agent was preserved in an infectious state in leafhoppers (Macrosteles fascifrons) that had been fed on infected asters and then frozen and stored as whole insects at -64 degrees C for up to 2 years. No difference in infectivity was observed between extracts prepared from insects stored at -28 and -64 degrees C for up to 21 weeks. Three solutions (glycine + magnesium chloride, glycine + magnesium chloride + sodium sulphate, and phosphate-buffered saline) were found to be equally suitable in preparing extracts from frozen leafhoppers.


Staphylococcus aureus and the microbial ecology of atopic dermatitis.

Two surveys were conducted to ascertain the effect which Staphylococcus aureus has on resident flora and on skin of patients with eczema. Forty paired sites, normal and lesions, were sampled from 32 patients with chronic lichenified atopic dermatitis, and 162 sites covering the entire body of a patient with an acute flare of chronic atopic dermatitis were examined. In the first study, 34 lesions (85%) carried S. aureus, and 85% of these positive samples supported greater than 10(4) colony-forming units (CFU) of total aerobic bacteria/cm2. About 55% of normal sites carried S. aureus with 18% of such samples supporting greater than 10(4) CFU/cm2 total aerobic bacteria. Normal sites carried fewer but more diverse flora than lesions. The composition of flora on lesion sites was mainly S. aureus or S. epidermidis biotype 1, or both. At densities greater than 10(7) CFU/cm2, S. aureus constituted almost 100% of the total aerobic bacterial flora. The total body survey of the single eczema patient yielded similar results. Evidence supports the hypotheses that (1) S. aureus is able to exploit the environment of eczematous lesions and to influence the composition of cohabiting aerobic skin bacteria, and (2) its inhabitation of normal appearing sites is transitory.


The sporulation process in Thermomonospora fusca as revealed by scanning and transmission electron microscopy.

The sporulation process in the thermophilic actinomycete Thermomonospora fusca was observed by scanning and transmission electron microscopy. As shown by scanning electron microscopy, spores were produced primarily on aerial hyphae and first appeared as bud-like enlargements at the tips of short multibranched sporophores. Young spores were oval to spherical in shape with a smooth surface. As they matured spores enlarged and developed a rough and globular covering, which was quite fragile and easily detached from the spore. This outer layer, as observed by transmission electron microscopy, was thought equivalent to the sheath of other Thermomonospora species. In cross section, mature spores exhibited a thick spore coat underneath the outer globular layer. This spore coat was usually observed as a single layer, but some spores produced a bilayered coat. No multilayered spore coat or spore cortex was observed in the heat-sensitive spores of T. fusca. They were, therefore, shown to be aleuriospores (microcondia), and not endospores.


The intracellular reserve polysaccharide of Clostridium pasteurianum.

An amylopectinlike polysaccharide (granulose) was the only glucan produced in significant quantities by six wild-type strains of Clostridium pasteurianum grown in glucose minimal medium. The intracellular polysaccharide granules laid down before sporulation contained only this amylopectin. No intracellular dextran was discovered in these wild-type strains, nor in a granulose-negative mutant strain of C. pasteurianum possessing an ADP glucose pyrophosphorylase (EC2.7.7.27) but lacking a granulose synthase (i.e. ADP glucose-alpha-1,4-glucan glucosyl transferase, EC2.4.1.21). Furthermore, methylation analysis demonstrated that (1 leads to 6) linked alpha-D-glucose units accounted for less than 2% of the entire glucose content of these organisms.


Deoxyribonucleic acid relationships among marine vibrios pathogenic to fish.

Polynucleotide sequence relationships among 19 strains of marine vibrios, 15 of which were pathogenic to fish, were assessed by analysis of DNA-DNA homo-and hetero-duplexes with the endonuclease S1. DNA base compositions (mole% guanine-cytosine (GC) of selected vibro strains were determined by thermal denaturation. Pathogenic strains from the Pacific Northwest had identical mole% GC but could be divided into two discrete, yet related, DNA-homology groups. One highly related group was typical of Vibro anguillarium and showed greater than 70% within-group polynucleotide sequence homology. Second group (designated V1669) showed greater than 83% within-group homology but only about 60% relatedness to V. anguillarum. Neither group showed a significant degree of relatedness to V. parahaemolyticus (biotypes parahaemolyticus or alginolyticus) or to representative strains of any of the other previously described homology groups which we tested.


Effects of certain cations on the formation and infectivity of Phytophthora zoospores. 1. Effects of calcium, magnesium, potassium, and iron ions.

The effects of four cations, Ca2+, Mg2+, K+, and Fe3+, upon the production of zoosporangia by isolates of four species of Phytophthora in axenic culture have been investigated. A response surface design was used to examine main effects and possible interactions. Responses to Ca2+ and Fe3+ were strongly quadratic with the higher concentrations inhibiting sporangial production in P. cinnamomi and P. drechsleri isolates. Responses to Mg2+ and K+ were weaker and, in the case of magnesium, were linear rather than quadratic. There was no significant interaction between cations except in the case of P. cambivora where the interaction between Mg2+ and K+ was significant at the 5% level. For each cation, the optimum concentration for zoosporangial production was calculated. The processes of zoospore release and infection of plant material by P. drechsleri showed a strong linear and weak quadratic response to Ca2+, higher concentrations of Ca2+ favouring these processes. A strong quadratic response was obtained to Mg2+, K+, and Fe3+. Interaction between  Ca2+ and Mg2+ was evident for all three host materials used; Mg2+ and K+ showed an interaction when Pinus radiata was used as the host material. The implications and limitations of these results are discussed.


Fundamental nature of human infant's brain asymmetry.

Morphological speech zone asymmetry in man cannot be due to environmental or developmental factors after birth. The functional implication of such a finding is not yet clear. Morphological asymmetry of the human brain is paralleled by electrophysiological evidence of cerebral hemispheric asymmetries. The results of our analysis of 50 infants suggest that clear occipital-temporal coherency asymmetry similar, but not identical to the adult pattern, also exists at or near birth. These asymmetries are generated by stimuli with no verbal content and in infants who presumably have no or an undeveloped capability for language. It is suggested that language is only a part of much more fundamental asymmetries which include the processing of auditory and visual information. Our results, and those of other, are consistent with the assumption that the left hemisphere is more able to relate stimuli to past experience, either short or long-term, while the right hemisphere is more able to process, stimuli which are not easily identifiable or referable. These capabilities would not be based on language, and hence would be expected to develop independently and possibly before speech. The demonstration that reversing electrophysiological asymmetries can be generated with non-speech stimuli in the visual and auditory modalities, and in neonates, supports such an assumption.


A non-permanent tonic pupil in rheumatoid arteritis.

A 76-year-old male with a severely deforming rheumatoid arthritis, eosinophilia, polymyositis, and episcleritis developed a transient tonic pupil. The episcleritis, and a muscle biopsy revealing an occlusive arteritis with eosinophilia, suggest that a wide-spread rheumatoid arteritis caused a reversible ischemic insult to the ciliary ganglion and thus created a transient denervation of the pupil.


Giant cell tumor of the sphenoid bone.

The clinical and histological features of two cases of giant cell tumor of the sphenoid bone are described. Both presented with similar symptoms and signs, comparable to previously described cases. The problems in histological differential diagnosis are discussed and radiotherapy as the treatment of choice is suggested.


[Anal fissure].

The etiology of anal fissure remains controversial and the multiplicity of theories suggests a number of different causes. Histologic and manometric studies have shown abnormalities of the internal anal sphincter in this condition. The clinical features are described briefly. Generally accepted principles of medical management have been arrived at by common sense rather than through well-controlled studies. Surgical treatment in its various forms consists in producing a laceration of the internal sphincter. Lateral sphincterotomy gives the best results from the point of view of recurrence or incontinence; posterior sphincterotomy, which leads to a key-hole deformity, appears to produce the highest incidence of incontinence. It is not possible to determine from published reports the respective advantages of complete versus partial posterior sphincterotomy.


[Rectal fistula].

It is now possible to define with precision the pathogenesis of anal fistulous abscesses. Common as well as rarer types of fistulas can be classified according to the anatomy of the anal canal. Identification and proper treatment of these conditions need a thorough systematic approach; knowledge of their symptomatology, anatomy and pathology is of paramount importance, and successful treatment is based on accepted surgical principles. A detailed description of the management of these fistulas is presented. Factors explaining recurrences are also mentioned.


Prophylactic node dissection for malignant melanoma.

The value of prophylactic node dissection was studied in 147 patients with nonsuperficial malignant melanoma of cutaneous origin; all had clinical stage I disease. Seventy-three patients had prophylactic node dissection and 74 did not. Survival rates were calculated by the actuarial method and were age and sex adjusted. Five-year crude survival rates for these two groups were 62 and 29%, respectively, and the adjusted rates were 70 and 33%, respectively. These significant differences (P less than 0.001) were  maintained at 10 years. The difference in survival in the two groups cannot be explained on the basis of age, sex, year of operation, size or location of the primary tumour, or previous incisional biopsy. It is concluded that prophylactic node dissection contributed appreciably to increased survival in this study.


Wound infection after gastroduodenal operations: a 10-year review.

A review of 444 gastric operations performed over a 10-year period revealed striking differences in wound infection rates when the operations were categorized according to the major indication for surgery. On this basis, low-intermediate- and high-risk groups were recognized. A subsequent prospective randomized study confirmed the predictive value of this categorization and showed that the administration perioperatively of prophylactic systemic antibiotics in high-risk patients will protect them from postoperative wound infection.


Hemobilia associated with a traumatic arteriovenous fistula.

Although there have been many reports of hemobilia, its association with an arteriovenous fistula within the liver is extremely rare, only two cases having been reported in the world literature. The authors describe a third case in which a gunshot injury to the liver of a 19-year-old man resulted in the development of hemobilia demonstrated radiologically to be associated with an arteriovenous fistula. The condition was successfully managed by ligation of the proximal hepatic artery.


Leiomyosarcoma of the rectum and prostate.

A 47-year-old man with leiomyosarcoma involving the rectum and prostate was treated by radical abdominoperineal resection. This case appears to be unique in that leiomyosarcoma was present in both the rectum and the prostate. The literature is reviewed, highlighting some interesting clinical features of this condition. The prognosis for leiomyosarcoma of both rectum and prostate is poor.


Role of aspiration breast biopsy.

Review of the results of 100 consecutive aspiration breast biopsies disclosed that this technique failed to identify 11 of the 33 breast cancers in the series; however, it identified 3 breast cancers that were not recognized by clinical examination. In one patient who had a fibroadenoma, suspicious cells were seen in the material sent for cytologic examination. It is concluded that a negative aspiration biopsy does not contraindicate tissue biopsy when the clinical findings suggest cancer. Aspiration biopsy can uncover clinically unsuspected cancers. When the lesion appears to be malignant on a clinical basis, aspiration biopsy can obviate formal biopsy. In this way time is saved for all those involved and the fashioning of the mastectomy flaps is facilitated.


The relation between ileal resection and vitamin B12 absorption.

Over 15 years, 33 patients, who had had 36 ileal resections that included the terminal ileum, had Schilling tests to measure the absorption of vitamin B12. In 11 patients who had 60 cm or more of ileum removed, only one test was normal, while in 25 patients with less than 60 cm resected, 17 tests were normal. Seven of the patients with over 60 cm of ileum resected had stool-fat estimations and none were normal. Eight of 10 patients who had less than 60 cm of ileum resected had normal stool-fat estimations. Results of the Schilling test, but not of the stool-fat estimations, are proportional to the length of ileal resection, up to 60 cm. Retention of terminal ileum tends to preserve vitamin B12 absorption capacity. Thus, if more than 60 cm of terminal ileum is removed, fat and B12 malabsorption are likely. The Schilling test is an indicator of the degree of terminal ileal dysfunction.


Postoperative flexion contracture of the knee: a simple technique for its treatment.

Flexion contracture is not a common problem following knee surgery, but it can be severe enough to jeopardize the success of the operation. With the Beath technique a stove-pipe cast is windowed anteriorly and the cast is padded behind the leg, which is then gently wedged into extension. In this way many flexion contractures can be gently and easily overcome. In addition, the need for serial casting or forcible manipulation is obviated and the overall rehabilitation program is unimpeded. In this paper the authors report two illustrative cases, and discuss the advantages and applications of the Beath technique.


Evaluation of the Canadian Home Fitness Test in middle-aged men.

The Canadian Home Fitness Test (CHFT) and the Bruce treadmill test were performed by 230 men aged 45 to 69 years. Because of inaccuracies in the counting of heart rates, less was known about the fitness of the men after testing than before. In addition, inaccuracies in the test record and design were uncovered. A more accurate estimate of fitness could be obtained when the subjects' own rating of exertional intensity was substituted for heart rate counting. The CHFT is a marketing tool of Health and Welfare Canada that may be useful in selling fitness, but as a measure of fitness in Canadian homes it is likely to be misleading.


Management of hepatic injury.

Liver injuries may be due to either blunt or penetrating trauma to the thorax or abdomen. Specific treatment depends on the site and extent of hepatic injury. Following resuscitation with intravenous fluids and blood as needed, surgical therapy is directed to provide hemostasis, remove necrotic liver tissue and promote adequate external drainage in the postoperative period. While local measures are usually sufficient, complex hepatic wounds may require extensive resection and vascular ligature or repair.


Early diagnosis of salt-losing congenital adrenal hyperplasia in a newborn boy.

Assays of serum 17-hydroxyprogesterone concentration may be relied upon to establish a diagnosis of congenital adrenal hyperplasia within a few hours of birth. In a male infant the concentration of 17-hydroxyprogesterone was increased in cord serum and remained elevated until glucocorticoid therapy was started on the 5th day of life. Plasma renin activity was increased only slightly in the first few days, but a striking increase on day 5, along with a gradual increase in the serum potassium concentration, confirmed that the infant had the salt-losing form of congenital adrenal hyperplasia. It was not possible to demonstrate an increased concentration of 17-hydroxyprogesterone, in amniotic fluid obtained at 30 weeks' gestation, presumably because of interference in this assay by cross-reacting steroids. Studies of the mother's serum concentration of 17-hydroxyprogesterone and cortisol during delivery did not disclose any deviation from normal.


Acute poisoning: an update.

Treatment of the patient who has taken an overdose of a harmful substance includes support of vital functions and toxicologic analysis. Early recognition of signs and symptoms indicating poisoning by a specific agent or group of related chemicals is essential since specific antidotes may be lifesaving. Activated charcoal is an effective gastrointestinal decontaminant that adsorbs many common drugs. Administration of weak acids as an antidote to alkali ingestion is to be condemned; the only treatment should be dilution with water. The use of physostigmine as a specific antidote for the anticholinergic syndrome has been very successful; the incidence of this syndrome as a result of poisoning by tricyclic antidepressants is increasing. Effective therapy for acetaminophen overdose is still being investigated, but activated charcoal and methionine, if given early enough, seem to be effective.


The new psychotherapies: the courage to be.

The past decade has seen the emergence of popular "new psychotherapies" such as Gestalt Therapy, Transactional Analysis, and Primal Therapy, each with substantial followings. This paper puts forward a hypothesis about what these divergent systems may possess in common. Certain aspects of these therapy systems, in particular the induction of new patients and trainees, are examined in terms of Paul Tillich's concepts of the universal necessity of a rationale for courage. The significance of Tillich's analysis of courage for various historical movements is reviewed. In each system an element of unconditional commitment to a particular world  view is required, as evidenced in the writings of the proponents of these systems, for the patient to be accepted into the particular system. These theoretically divergent systems possess, in common, a factor of an initial commitment to and induction into a collective belief system comparable to what Tillich describes as "the courage to be as a part".


The new androgyny: therapy of "liberated" couples.

Under the impact of women's liberation, many couples are seeking to develop relationships in which roles are less sex-linked and more androgynous. To help such couples and their families, therapists must re-examine and modify their own sexist preconceptions. However to be effective even the most "liberated" therapist and couple must distinguish between problems arising from sexism and from each member's personal history and psychodynamics.


Alcoholism and gun control.

The recurring dilemma of having to deal with an intoxicated person in possession of a gun uttering homicidal or suicidal threats along with the current debate on gun control prompted this controlled survey of the characteristics of individuals with problems arising from the joint abuse of alcohol and possession of a gun. A comparison of the data point to violence as being the most significant differentiating variable involved. This violent potential was reflected by the presence among the alcoholics involved of more past and present antisocial traits, a higher rating on the Nicol's scale of violence, more offences committed against the person and homicidal behaviour. The availability of a gun was a significant factor. No correlation was found between the severity of the drinking problem and the risk of dangerous handling of a gun. The need for more stringent gun controls is supported but their implications to the physician and especially the psychiatrist as a potential guarantor for a licence application ought to be further explored by the professional bodies involved.


Treatment of acute nonlymphocytic leukemia in elderly patients: a prospective study of intensive chemotherapy.

Twenty-seven patients over 60 years of age with acute nonlymphocytic leukemia (ANLL) were prospectively treated with one of three intensive chemotherapeutic regimens. Complete remissions were achieved in eight patients (30%). Remissions were obtained in seven of 14 patients (50%) age 61 to 70 years, but in only one of 13 patients (8%) 71 years and older. The most effective regimen in patients 61 to 70 years consisted of a combination of daunorubicin and cytosine arabinoside. The median duration of remission for all eight responders is 9+ months and their median survival is 14+ months. Intensive therapy is indicated in the elderly patient 61 to 70 years of age with ANLL.


Ultrastructure of the mesothelioma of the atrioventricular node.

In order to determine the histogenesis of tumors of the atrioventricular node, so-called conduction tumors, two such tumors were serially blocked for electron microscopy. Ultrastructurally these tumors were composed of nests of cells arranged in small channels and tubules set in a connective tissue stroma. The cells lining the tubules were flattened or low cuboidal and had abundant microvilli over the lumen surface. The cells were joined by specialized junctions along their lateral adjacent borders, especially at the luminal surfaces, and intercellular spaces delineated by specialized junctions were frequent. Microvilli, intercellular spaces bounded by tight junctions, and complex intercellular junctions are features of mesothelial cells, and especially of benign mesothelioma of the genital tract. These results strongly suggest that the cardiac conduction tumor is derived from mesothelial cells and is in fact a mesothelioma of the atrioventricular node.


Ultrastructure of elastofibroma.

An elastofibroma from a 69-year-old white man was studied by light and electron microscopy. The lesion was comprised of abundant collagen fibers and numerous randomly disposed masses of amorphous elastinophilic material. Ultrastructurally, this material appeared to be derived from a markedly dense, finely fibrillar precursor secreted by fibroblasts and manifested a striking resemblance to young elastic tissue. Central cores of mature elastic tissue were recognized within some of these elastinophilic masses. This study demonstrates unequivocally that the abnormal elastic material in elastofibroma is derived from excessive production of young elastic tissue and not from elastotic degeneration of collagen, as suggested in some of the previous studies. This young elastic tissue manifests a marked retardation of maturation, the cause of which however is not clear. Another interesting finding in this case was the presence of prominent fibrous laminae within the nuclei of most of the fibroblasts. The significance othis finding is briefly discussed.


Acinic cell carcinoma: long-term survival after pulmonary metastases: light and electron microscopic study.

Metastatic pulmonary nodules discovered 6 years after superficial parotidectomy for an acinic cell carcinoma in a 61-year-old man were studied by light and electron microscopy. The lesions were composed of clear cells and darker, gland-forming cells with granular cytoplasm, which by electron microscopy demonstrated features of ductal and acinar serous cells, respectively. Cytologic evidence of malignancy, such as extensive necrosis, nuclear pleomorphism, significant mitotic activity, incomplete encapsulation, and perineural invasion was present. The patient is free of tumor 5 years after resection of the pulmonary lesions. In view of the indolent growth characteristics of this tumor, a more aggressive surgical approach to metastatic tumor foci is recommended.


Amylase-producing lung cancer: ultrastructural and biochemical studies.

A case of lung cancer with elevated amylase activity in serum, urine, and tumor tissue was studied electron microscopically and biochemically. Ultrastructurally, there were numerous electron-dense granules in the cytoplasm of most tumor cells. These granules were located in the apical region of tumor cells and had a single limiting membrane, associated with a clear zone just beneath it. Furthermore, circular, lamellar and annulate structures, which closely resembled those observed within zymogen granules of the salivary glands in postnatal mice and rats, were sometimes recognized within these granules. These observations suggested that these granules were identical to a postnatal or immature form of zymogen granules in salivary glands. Biochemical analysis confirmed that the amylases obtained from the tumor tissue were composed of the sialic acid-containing glycoprotein, which was not found in normal amylases. A possible histogenesis of the amylase-producing lung cancer was briefly discussed.