bluuebunny/crossref_metadata_2025_split huggingface dataset:
AN ELECTRON MICROSCOPIC STUDY OF HASHIMOTO THYROIDITIS
Authors: Irvine W. J. , Muir A. R. 
Published: December 2014

An electron microscopic study has been made of thyroid tissue obtained from four patients with Hashimoto thyroiditis. Contrary to what has been inferred from earlier light microscopy studies, the basement membrane in Hashimoto thyroiditis is remarkably continuous, taking the form of a single lamina some 50 mµ thick. It differs from that of the normal adult human thyroid in that there is no re‐duplication of the membrane. In Hashimoto thyroiditis, temporary gaps in the basement membrane occur which are just sufficient to allow the passage of leucocytes in and out of the thyroid follicles. Small breaks in the basement membrane may occur in necrotic thyroid follicles, and cytoplasmic debris of the epithelial cells then escapes into the stroma.A mutual activity between invading lymphocytes and the epithelial cells of the thyroid follicles is inferred from the observation that tenuous processes of the epithelial cells embrace the invading lymphocytes and that bulbous lymphocytic processes abut against or invaginate the epithelial cells. It is conceivable that this intimate contact allows antibody bound to the lymphocyte to be directly transferred to the cells of the thyroid epithelium.
DISTRIBUTION AND EXCRETION OF RADIOMANGANESE ADMINISTERED TO THE MOUSE
Authors: Kato Mikita 
Published: December 2014

In order to elucidate the physiological meaning of trace elements in living organism, studies on radiomanganese were carried out in the mouse with special reference to its distribution and excretion. After the nuclear reaction 52Cr(d, 2n)52Mn by the cyclotron, 52Mn was separated by the radiocolloid method. Carrier‐free 52MnC12 was dissolved in 0·9 per cent NaCl solution (F‐solution), and purified MnCl2 was added as carrier to the above solution (C‐solution). Each solution was injected into a tail vein of an adult male mouse.In both experiments with F ‐ and C‐solution, the amount of radiomanganese found in the various tissues after 24 hr. was in decreasing order as follows: kidney, pancreas, liver, intestine, skin, muscle, brain and blood. As the carrier manganese included in C‐solution increased, the amount of radiomanganese in tissues was generally lowered. Such a carrier‐effect was dependent on the concentration of administered carrier. In bone the carrier‐effect was not apparent.The amount of radiomanganese in all the tissues appeared to attain its maximum within 2 hr. after administration in all experiments. However, in the experiment with F‐solution, the elimination of radiomanganese from the tissues proceeded more rapidly.The excretion of radiomanganese mainly proceeded through the feces, and the rate of excretion reached its peak about 10 hr. after administration. Such a rapid excretion probably takes place through a pathway from the intestinal epithelium into the alimentary canal. The amount of excretion for 7 days was 93 and 60 per cent of administered radiomanganese for the experiments with F ‐ and C‐solution, respectively.
AUTORADIOGRAPHIC OBSERVATIONS OF MANGANESE IN ADULT AND EMBRYO MICE
Authors: Kato Mikita , Hara Tomiyuki , Koshida Yutaka 
Published: December 2014

In connection with the previous work, autoradiographic studies on the distribution of radiomanganese in the mouse tissues were carried out on the adult and the embryo.Results from the adult are summarized as follows. In the kidney, 52Mn is accumulated more abundantly in the cortex than in the medulla. On precise examinations, 52Mn is detected remarkably within the epithelial cells of renal tubules but scarcely in the lumen. In the intestinal villi, 52Mn is found conspicuously in the epithelium and in the mucus cohering to its free surface, which fact may offer a reasonable ground for manganese excretion through intestinal epithelium. 52Mn is retained in the exocrine portion of the pancreas but not in the islets of Langerhans, and in the liver it is uniformly distributed over the tissues except the lumens of blood vessels. 52Mn‐retention in the blood is extremely small.In the early embryos, 52Mn‐concentration is less than in the placental tissues. In the late embryos, 52Mn‐accumulation in the bone proceeds in parallel with the progress of ossification and 52Mn‐concentration in the kidney is less than in the liver, conversely in the case of the adult.From the present autoradiographic observations, the physiological meaning of manganese found in tissues has been discussed with reference to the previous work.
THE VASCULAR RESPONSES OF MALE AND FEMALE RATS TO VASOPRESSIN AND OXYTOCIN FOLLOWING A SINGLE DOSE OF TESTOSTERONE PROPIONATE
Authors: Honoré L. H. 
Published: December 2014

The vascular responses of male and female rats to the posterior lobe hormones were studied following a single dose of testosterone propionate given 24 hr. previously (1 mg.). All normal females, when treated with testosterone, became less sensitive to vasopressin; after oophorectomy testosterone had no further desensitizing effect during the period of reduced responsiveness, after which marked desensitization was shown. Most of the normal males became less sensitive to vasopressin after testosterone, but a few were more sensitive; testosterone prevented the appearance of both qualitative and quantitative changes in the vascular reactivity of orchidectomized male rats.After testosterone oxytocin became a pressor substance in the majority of both males and females. Occasionally an initial depressor phase was obtained in testosterone‐treated animals of both sexes following vasopressin and oxytocin; it was always suppressed by the administration of dihydroergotamine.These results are discussed in relation to the previously reported effects of castration, œstrogen pretreatment and sympathetic blockade.
RENAL FUNCTION IN SHEEP WITH AN EXTERIORIZED URETER
Authors: Stacy B. D. , Brook A. H. 
Published: December 2014

Studies of bilateral renal function have been made in four sheep with chronic unilateral ureteral fistulæ. From a comparison of PAH and creatinine excretion it was concluded that renal hæmodynamics and tubular secretory capacity for PAH were similar in the two kidneys. Also there was no gross difference between the kidneys in the rate of urine formation, the excretion of potassium and urea, and the ability to concentrate and acidify urine. When tested several months after transplantation, comparable bilateral excretion of sodium was seen in two of the experimental animals; in the other two sheep slightly more sodium was excreted by the kidney with the diverted ureter.It is concluded that cutaneous ureterostomy in the sheep does not impair renal function. This surgical preparation is therefore a valuable one for studying the function of the kidney in undisturbed sheep.
THYROID AUTO‐IMMUNITY AS A DISORDER OF IMMUNOLOGICAL TOLERANCE
Authors: Irvine W. J. 
Published: December 2014

The immunological response to thyroid damage has been studied in the 101. thyrotoxic patients treated with radioactive iodine (131I). Patients who had positive titres of thyroid complement‐fixing (CF) antibody in the sera before treatment invariably showed a rise in titre of this antibody commencing approximately 6 weeks after treatment but always falling to pre‐treatment or lower levels after some months. Only in exceptional cases was there any formation of the thyroid CF antibody in patients who had negative thyroid CF tests before treatment; this was so even when the 131I treatment was repeated on two, three or four occasions. In general, the change in thyroid CF titre was more pronounced than the change in titre of antibody to thyroglobulin.Although the epithelial cells of the human fectal thyroid are rich in thyroid cytoplasmic antigen, the basement membrane is even more delicate than that noted in Hashimoto thyroiditis affecting the adult gland.A preliminary study has been made of the thymus in Hashimoto thyroiditis. Numerous germinal centres were observed in a thymic biopsy in one case and the radiological appearances of an enlarged thymus were noted in two others.These several findings are considered in terms of the possible meclhanisms of auto‐immunity and the view is taken that formation of thyroid auto‐antibodies is a result of a genetically determined disorder of immunological tolerance.
ULTRASTRUCTURE OF VASCULAR ENDOTHELIUM IN THE FROG
Authors: Stehbens W. E. 
Published: December 2014

An electron microscopic investigation of the endothelium of capillaries and venules of the frog (Hyla cœrulea) revealed, as well as the usual cytoplasmic constituents, several new features.In the endothelial cells three types of vesicle were encountered, each of which could be highly selective in the transport of materials across the vessel wall. The well‐recognized micropinocytotic vesicles of light density were most numerous. Less frequently seen, and hitherto unobserved in endothelium, were the dense‐walled micropinocytotic vesicles which at other sites are associated with protein uptake. Large vesicular spaces similar to the macropinocytotic vesicles described by Fawcett [1963] were readily observed.Fenestrated endothelium occurred in attenuated segments of endothelial cells in the tongue as well as in the gut. Fenestrae were seen in the walls of macropinocytotic vesicles and along the cytoplasmic processes projecting into the lumen or along those which overlapped adjacent cells.At intercellular clefts, tight junctions predominated. Occasional intermediate junctions were found but no desmosomes.Thick basement membranes, the result of the coalescence of a thin endothelial basement membrane and thick convoluted laminae related to pericytes and adventitial cells, were found about vessels particularly in the tongue.Microtubules and microtubular bodies of unknown significance were observed.
JUNCTIONAL COMPLEXES OF THE HAMSTER VAGINA, UNDER NORMAL AND EXPERIMENTAL CONDITIONS
Authors: Vargas‐Linares Clara E. Roigde , Burgos Mario H. 
Published: December 2014

The ultrastructure of the different junctional complexes of the stratified epithelium of the hamster vagina at late metestrus has been studied both under normal conditions and after perfusion with EDTA. Four types of junctions are described through which the vaginal cells adhere both to each other and to the basement membrane. These junctions are: the typical desmosome; the tight junction; the adhering band, and the basal junction.After the calcium depletion due to EDTA, the desmosomes open up and there is a disappearance of the central laminar density. This causes the extension of the intercellular spaces. The other junctions, with the exception of the adhering bands in the vicinity of the desmosomes, appear to be resistent to EDTA.These EDTA‐induced changes are similar to those produced by leucocyte invasion of the vaginal epithelium in metestrus.
THE EFFECTS OF SODIUM DEPLETION AND POTASSIUM SUPPLEMENTS UPON ELECTRICAL POTENTIALS IN THE RUMEN OF THE SHEEP
Authors: Scott D. 
Published: December 2014

Measurements were made of the electrical potential gradient between the blood and the rumen contents of sheep made sodium deficient by the withdrawal of parotid saliva.Loss of saliva resulted in an increase in the concentration of potassium and a fall in the concentration of sodium in the rumen fluid, and these changes were associated with an increase in the rumen potential. The results suggest that a potential arising from the passive diffusion of potassium into the blood may contribute significantly to the total potential which is generated across the rumen wall. The change in rumen composition appears to be due to a change in the relative amounts of sodium and potassium entering the rumen. This results from both the loss of saliva and a change in the composition of saliva entering the rumen, since the ratio of Na: K in the parotid saliva falls in response to sodium deficit through the secretion of adrenal hormones.There is, so far, no indication that adrenal hormones exert any independent influence on the rumen potential other than through a change in the composition of the saliva and rumen fluid.
BONE STRENGTH AND CALCIUM RETENTION OF RATS IN HYPERVITAMINOSIS‐A
Authors: Khogali A. 
Published: December 2014

Newly‐weaned male albino rats were fed by gavage excessive doses of vitamin A for 4 weeks either alone or with one of the thyroid hormones: L‐triiodothyronine and D‐triiodothyronine. Some rats were given the thyroid hormones alone. It was found that:1. The rats fed 6000 i.u. and 12,000 i.u. vitamin A per day gained weight normally and did not sustain spontaneous fractures.2. A dose of 24,000 i.u. vitamin A per day retarded the growth of the rats and spontaneous fractures of the long bones (mainly tibiæ) occurred.3. The bones of the animals suffering from hypervitaminosis‐A were abnormally thin and their bending moment at breaking was significantly reduced. The breaking stress (quality) of the bones was also reduced but this can be explained by a change in texture of the bones and is not due to altered quality of the bony material. The stiffness (E) of the bones was not affected.4. The percentage mineral content of the bones from hypervitaminotic rats was normal, but the total calcium retention of the animals was reduced.5. L‐triiodothyronine and D‐triiodothyronine in doses of 5 µg. per day aggravated the skeletal changes in hypervitaminosis‐A.6. The thyroid hormones alone did not produce any significant changes in the physical properties of the femora of rats.It is suggested that, in hypervitaminosis‐A, the quantity and distribution of the bony material is disturbed but its quality is probably unaltered.
RÔLE OF ADRENERGIC FACTORS IN THE PRODUCTION AND PERPETUATION OF ATRIAL FLUTTER IN THE DOG
Authors: Sharma P. L. 
Published: December 2014

The rôle of adrenergic factors in the production and perpetuation of atrial flutter has been studied in dogs under pentobarbitone sodium anaesthesia. The adrenergic influence was (a) increased by sympathetic stimulation or by intravenous injection of adrenaline and noradrenaline and (b) decreased by depletion of cardiac stores of catecholamines by previous treatment of the animals with reserpine.Sympathetic stimulation, as well as adrenaline and noradrenaline increased the atrial rate in aconitine‐induced and post‐stimulatory atrial flutter, and in some cases the flutter was converted into fibrillation. Atropine sulphate only partially blocked the increase in flutter rate, but atrial fibrillation never occurred after atropine administration.In some cases of aconitine‐induced atrial flutter, as the peak effect of adrenaline was passing off the atrial rate fell below that of sinus rhythm for a few seconds, and then gradually increased to the control level. No such response was seen after noradrenaline administration.When cardiac stores of catecholamines were depleted by previous treatment of the animals with reserpine, aconitine produced long‐lasting atrial fibrillation in all the experiments. Atropine injection converted atrial fibrillation into slow rate atrial flutter. In such animals, electrical stimulation produced transient atrial fibrillation, the rhythm returning to normal sinus rhythm, a few seconds to a few minutes after the stimulation ceased. It was not possible to induce stable atrial flutter despite repeated attempts, and even after the administration of atropine.The mechanism of these findings is discussed.
THE EFFECTS OF BOTULINUM TOXIN ON THE PATTERN OF INNERVATION OF SKELETAL MUSCLE IN THE MOUSE
Authors: Duchen L. W. , Strich Sabina J. 
Published: December 2014

Sublethal quantities of botulinum toxin were injected into the gastrocnemius and hamstring muscles of one leg in mice. Local paralysis and atrophy occurred and persisted for a few weeks. Histological examination showed no degeneration of nerve fibres or of motor nerve endings. Silver impregnations showed that during the period of muscle paralysis there was growth of motor nerve fibres from the terminal arborizations. Nerve fibre overgrowth was accompanied by elongation and abnormal configuration of sites of cholinesterase activity. As muscle function recovered the nerve fibre overgrowth receded and well‐formed though still abnormally shaped subneural apparatuses were seen. Nine months after the injection of the toxin, the pattern of innervation of the muscle was still abnormal.The growth of motor nerve fibres after the injection of botulinum toxin appears to be a response to the failure of neuromuscular transmission and is not analogous to regeneration of nerve fibres after trauma.
RESPIRATORY AND CARDIOVASCULAR CHANGES DURING ASPHYXIA AND RESUSCITATION OF FŒTAL AND NEWBORN RABBITS
Authors: Godfrey S. 
Published: December 2014

A study has been made of the respiratory and circulatory responses to asphyxia and resuscitation of fœtal and newborn rabbits. Fœtuses were both delivered and maintained under isotonic saline, while newborn animals were asphyxiated in an atmosphere of N2 after light ether anæsthesia. Both groups were resuscitated by intermittent positive pressure ventilation with 02, begun after the last spontaneous gasp of asphyxia.The response to asphyxia was very similar in the two groups. There was a short initial period of (primary) apnœa, accompanied by a sudden fall in heart rate and blood pressure. This hypotension and bradycardia during the early part of asphyxia was reduced by vagotomy. Following primary apnœa, the animals gasped for some 15–20 min. and then again became apnœic (secondary apnœa). The heart rate and blood pressure fell further and, in the absence of external interference, the animals died. Resuscitation was successful, provided the blood pressure was above 5 mm. Hg at the start of I.P.P. ventilation. The heart rate and blood pressure invariably rose before the return of respiration in the successful cases. The Hering‐Breuer and paradoxical reflexes were fully active in the newborn rabbit, but were abolished by asphyxia due to a central nervous block. They did not return for several minutes after resuscitation.
MECHANICAL AND CHEMICAL CONTROL OF BREATH HOLDING
Authors: Godfrey S. , Campbell E. J. M. 
Published: December 2014

A method is described for the study of breath holding in which the breath holds are separated by rebreathing to enable accurate control of pCO2; its theoretical basis is discussed.At the end of a breath hold, rebreathing a mixture such that the pCO2 continues to rise, nevertheless permits the breath hold to be resumed. The number of breaths during the rebreathing is unimportant and a single breath permits as long a resumed breath hold as five breaths.Healthy adult males held their breath at residual volume. The relationship between breath holding time and pCO2 at the start or end of a breath hold was found to be linear; the higher the pCO2 the shorter the breath holding time. The relationship was unaffected by ten minutes of isocapnic hyperventilation.These findings imply that the duration of breath holding is directly related to pCO2 but is unaffected by the previous mechanical pattern of breathing.
INNERVATION OF THE OVARY OF THE DOMESTIC HEN
Authors: Gilbert A. B. 
Published: December 2014

The intrinsic innervation of the domestic hen's ovary consists of nerves running to the follicles and blood vessels. Both adrenergic and cholinergic components were identified.The extrinsic supply was a complex network of ganglia and nerves; the ovarian and adrenal plexuses were particularly extensive. Nerves were traced from both left and right sympathetic chains. No positive identification of a parasympathetic supply was made but, in view of the cholinergic fibres that were found within the ovary, it is probable that such a supply was present.The possible role of the innervation is discussed in relation to reproductive activity.
THE FINE STRUCTURE OF THE INFUNDIBULUM AND MAGNUM OF THE OVIDUCT OF GALLUS DOMESTICUS
Authors: Wyburn G. M. , Johnston H. S. , Draper M. H. , Davidson Maida F. 
Published: December 2014

The mucous membrane of the infundibulum and magnum of the hen's oviduct is modified for the receipt and fertilization of the yolk and the elaboration of the bulk of the solid material making up the white of the egg. The secreting surface is arranged in a series of ridges which are particularly elaborate in the neck region of the infundibulum. The surface is lined with columnar epithelial cells and there is a sub‐epithelial layer of tubular glands. There are two types of epithelial cell; ciliated, with little evidence of secretory activity; and granular, with the intracellular structure of a glycoprotein secreting cell. In the infundibulum the granular cells have electron dense granules and the tubular glands arise as invaginations from the epithelium of the deep crypts between the mucosal folds. The gland cells are structurally similar to the epithelial granular cells and have a characteristically large infranuclear granular endoplasmic reticular (GER) space filled with homogeneous material of low electron density, probably representing storage of synthesized protein. In the magnum the granules of the epithelial cells are of low electron density and fill the whole of the distended granular cell in the lower magnum, compressing the neighbouring ciliated cells.Three types of tubular gland cell are described in the magnum: Type A, filled with electron dense granules; Type B, filled with large masses of homogeneous material of low electron density; and Type C, occupied by GER cisternae together with a large and prominent Golgi area. The C cells, which are found in the magnum immediately after the passage of the egg, are regarded as the recovery phase of A cells which have discharged their granules on the passage of the egg. There is evidence that the dense granules of the A cells represent ovalbumin, the commonest protein of the egg white. The fibrous glycoprotein, ovomucin, with its large carbohydrate component, is probably produced by the granular cells of the magnum epithelium. There is a partial discharge of the secretion of the cells of the mucous membrane in response to the presence of the yolk. The nature of the secretion and the origin of some other components are discussed.
RESPONSE OF SINGLE VAGAL AFFERENT FIBRES TO MECHANICAL AND CHEMICAL STIMULATION OF THE GASTRIC AND DUODENAL MUCOSA IN CATS
Authors: Davison J. S. 
Published: December 2014

Single afferent fibres were dissected from the cervical vagus of adult cats and their response to mechanical and chemical stimulation of the gastroduodenal mucosa studied. All the units responded to light phasic mechanical stimulation of the mucosa but two different types of unit could be distinguished on the basis of their response to chemical stimulation. One type of unit responded to acidification of the mucosa while the other responded to application of high pH solutions to the mucosa. Each unit responded to one or other of these two forms of stimulation but not to both. Nor did any unit respond to any other form of chemical stimulation.Other functional characteristics, the location of the mucosal endings and the pathways of the units between the abdomen and neck are described. The possible role of these afferent units is discussed.