bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies on the histomorphology and histochemistry of the saccus vasculosus of Cyprinion macrostomus
Authors: Bhatnagar A.N. , Al-Noori S.A. , Gorgees N.S.
Published: February 2009

The saccus vasculosus of Cyprinion macrostomus is made up of coronet and supporting cells. Neurones are not observed. The luminal surface of the coronet cells exhibits hairlike protrusions. The saccus vasculosus is mainly concerned with a secretory function. Plenty of secretory material is seen in the lumen. PAS and alcian blue tests are positive for the secretory material in the lumen and the apical protrusions of the coronet cells. Some cells also exhibit small PAS- and alcian blue-positive granules. The possibility of the elaboration of glycogen by the coronet cells is ruled out. The toluidine blue test is also positive for the secretory material in the lumen and the apical protrusions. Small metachromatic granules are also seen in some of the coronet cells. The acetone-Sudan black B and Sudan black B tests point to a lipid moiety of the coronet cells, the apical protrusions and the secretory material in the lumen. The acrolein-Schiff and ninhydrin-Schiff tests point to a protein moiety of the coronet cells and the secretory material in the lumen. The performic acid-alcian blue test showed cystine to be present in small amount.
Activity of phosphatases and succinic dehydrogenase in the trigeminal ganglion of the corticosteroid-treated mouse
Authors: Silbermann Michael , Finkelbrand Sara
Published: February 2009

Immature mice were treated for 21 days with daily doses of triamcinolone diacetate. The trigeminal ganglion was studied enzymatically for the activity of alkaline phosphatase, acid phosphatase, ATPase and succinic dehydrogenase. It became apparent that the prolonged treatment with a potent corticosteroid hormone did not affect significantly the in vivo activity of the above enzymes. Some enzymes even appeared to have increased their intracellular activity. The heterogeneous effect of corticosteroid upon their peripheral target organs is discussed.
Localization of radioactively labelled serotonin in the nucleus of adrenal medulla cells
Authors: Csaba G. , Sudár F.
Published: February 2009

After treatment of rats with 3H-5-hydroxytryptophan, grains indicating the presence of serotonin could be demonstrated in the adrenal medulla. In the beginning, the label is mainly found in the cytoplasm, later, more and more it appears in the nucleus, primarily above the heterochromatin.
An electron microscope study of the effects of acute ischaemia in the brain
Authors: Fernando D.A. , Lau J.K.H.
Published: February 2009

The structural changes in the CNS of cats subjected to periods of 10 and 20 min of ischaemia have been studied. After 10 min of ischaemia the neurons show loss of granular endoplasmic reticulum and vacuolation of the persisting endoplasmic reticulum. After 20 min of ischaemia there is neuronal cell death, some synaptic degeneration. Glial foot processes swell and occlude the lumen of vessels. The significance of these changes is discussed.
Human coronary arteries
Authors: Velican Doina , Velican C.
Published: February 2009

A study on 22 pairs, including subjects of similar age, sex and cause of death but with different branching anatomical patterns, shows, that the amount and structural organization of elastic and muscular tissue of the thickened intima are strongly influenced by (a) the size, length, mode of ramification of the parent vessels of the coronary tree; (b) the number of branch orifices in a given arterial segment, and (c) the collateral or terminal character of certain daughter branches.
An analysis of molar tooth form
Authors: Lavelle C.L.B.
Published: February 2009

The maxillary first permanent molars of different human population samples were compared by multivariate analysis of two-dimensional coordinates of datum points defining the occlusal surface and periphery of the crown. This technique proved that discrimination was possible between teeth which could not be discriminated visually or by analysis of the mesio-distal or buccolingual diameters.
Observations on the ultrastructure of ganglion cells in the circumvallate papilla of rat and mouse
Authors: Graziadei P.PC. , Graziadei Monti
Published: February 2009

Ganglion cells in the circumvallate papilla of adult rodents are described as typical autonomic neurons. Some neurons are aggregated to form a discrete structure in the base of the papilla; others are scattered through the core, along the nerve bundles, and particularly near the dome. The term ‘circumvallate ganglion’ is applied to the entire population. Satellite cells completely ensheathe each neuron. Preganglionic fibers, containing clear vesicles, synapse on the soma and stumpy dendrites of the neurons. Axons, containing dense-cored vesicles, are observed in close proximity to the neurons. However, these fibers do not establish true morphological synaptic contacts with the neurons. We have not observed serial or reciprocal synapses on or in the vicinity of the ganglion cells. The hypothesis that the axons of the circumvallate ganglion neurons act as parasympathetic vasodilators is indicated by the proximity of the two structures and by nerve terminations on the arteriole muscle cells. Direct modulation of taste transduction by these neurons is ruled out.
Adrenergic innervation of the coronary arteries and the myocardium
Authors: Doležel S. , Gerová M. , Gero J. , Sládek T. , Vašku J.
Published: February 2009

The monoaminergic innervation of the coronary vessels and myocardium in the dog was studied by means of the histochemical fluorescence method. The distribution of monoaminergic terminals in the arterial wall depends on the diameter of the artery. In large arteries, the terminals are regularly distributed around the entire circumference, the fibres being situated between the elastic lamellae of the adventitia. The terminals within the media could not be detected. In small arteries, the sympathetic ground plexus aggregates in two parallel strands, the artery being between them. In arterioles, two thick fibres only accompany the vessel. The myocardium is innervated by means of a three-dimensional sympathetic ground plexus distributed between the myocardial cells independently of vessels. No difference in density of innervation was found between the right and left heart. The point-counting method, on the other hand, has revealed that the density of innervation in the left auricle is nearly twice as dense as in the left ventricle. The terminals innervating the myocardium are markedly thinner than the fibres innervating the arteries. Two-dimensional plexuses innervate the epicardium, endocardium and valves.
Arterial supply to the human rectum
Authors: Ayoub Soliman F.
Published: February 2009

The arterial supply to the human rectum was studied in 42 autopsy specimens. 32 were fixed in formalin and dissected. Five were radiographed after filling their arterial bed with a radio-opaque substance. The remaining five specimens were used to prepare plastic casts of the arterial bed. The superior rectal artery is the chief rectal artery. It forms a recto-sigmoid branch, an upper rectal branch and then divides into right and left terminal branches. Terminal branches extend downwards and forwards around the lower two thirds of the rectum to the level of the levator ani. The middle rectal artery, of appreciable diameter, on one or both sides of the rectum, is found supplying a limited part of the rectum in 12% of the specimens. Its presence can be anticipated by observing the diameter of the superior rectal artery and its two terminal branches. The inferior rectal artery supplies the anal canal below the levator ani. Rectal twigs of other pelvic arteries terminate at the pararectal tissues occasionally reaching the wall of the rectum. Extramural anastomoses were not observed between the main rectal arteries, but intramural ones were present, mainly between the superior and the inferior rectal arteries.
The effects of DNA administration on the growth of X-irradiated Xenopus tadpoles
Authors: Ahmad Mahmood , Niaz G.R. , Billett F.S.
Published: February 2009

An easy method for the harmless measurement of the length of tadpoles is described. The results indicate that tadpoles exposed to 3,000 r showed increase in length 20 days following irradiation. The animals exposed to the same or other X-ray doses and administered high molecular homologous and heterologous DNA showed a better rate of growth than the animals exposed to a dose of 3,000 r and not given DNA.
Nerves and nerve endings in the skin of tropical cattle
Authors: Amakiri S.F. , Ozoya S.E. , Ogunnaike P.O.
Published: February 2009

The nerves and nerve endings in the skin of tropical cattle were studied using histological and histochemical techniques. Many nerve trunks and fibres were present in the reticular and papillary dermis in both hairy and non-hairy skin sites. In non-hairy skin locations such as the muzzle and lower lip, encapsulated endings akin to Krause and Ruffini end bulbs, which arise from myelinated nerve trunks situated lower down the dermis were observed at the upper papillary layer level. Some fibre trunks seen at this level extended upwards to terminate within dermal papillae as bulb-shaped longitudinally lamellated Pacinian-type endings, while other onion-shaped lamellated nerve structures were located either within dermal papillae or near the dermo-epidermal area. Intraepidermal free-ending nerve fibres, appearing non-myelinated were observed in areas with thick epidermis. On hairy skin sites, however, organized nerve endings or intraepidermal nerve endings were not readily identifiable.
Development of the omasum in sheep
Authors: Lubis D. , O’Shea J.D.
Published: February 2009

Data are presented on the histogenesis of the omasal mucosa in sheep from the 2.5 cm crown-rump (c:r) length fetus to the adult. 11 stages of fetal development, and 4 post-natal stages, were studied. The distribution of glycogen in the omasal epithelium was also studied. During fetal life the omasal epithelium was initially stratified cuboidal in type, but the superficial layers of cells became flattened in later stages of gestation. This epithelium became extremely thick by the late stages of fetal life, reaching a maximum of 358 µm, and consisting of > 20 layers of cells, in the 45 cm c-r fetus (approximatelay 140 days). After birth the epithelium became markedly reduced in thickness, being ≈ 77 µm in the adult, and had differentiated into a cornified stratified squamous epithelium of the adult type by 12 weeks after birth. Glycogen was extremely abundant in the omasal epithelium of the 2.5 cm fetus, and declined gradually thereafter to be almost completely absent in post-natal specimens. 4 orders of laminae were present in the adult omasum, distributed in the sequence 1–4–3–4–2–4–3–4–1. The 1st order was already present in fetuses of 2.5 cm c-r length, with the 2nd, 3rd and 4th appearing by the 3.5, 5.5 and 11.0 cm stages, respectively. Initial stages in the development of conical papillae were first seen in 15.0 cm fetuses, but the development of these papillae was not completed until after birth.
A comparative morphometric study of synaptic vesicles and other organelles in mossy fiber endings of the pigeon and the rat
Authors: Paula-Barbosa M.M. , Sobrinho-Simões M.A. , Faria R.
Published: February 2009

The mossy fiber ending organelles of 4 rats and 4 pigeons were studied using ultra-structural morphometric methods. The number of agranular vesicles per square micrometer of synaptic surface, as well as the number of agranular vesicles per synapse, were found to be greater in the rat than in the pigeon, while no significant differences were found in coated and dense core vesicles. A highly positive correlation was found, in both species, between the synaptic surface and the number of agranular vesicles per unit volume of mossy fiber endings, while no correlation was found between the synaptic surface and numerical densities of coated and dense core vesicles.
An electron microscopical study of epididymal epithelium of rats treated with gonadotropic hormone
Authors: Erkoçak Aliye
Published: February 2009

The ultrastructural modifications of the epithelial cells of rat corpus epididymis stimulated with gonadotropic hormone were studied. The structural variety of the cells depending on functional conditions becomes more prominent 6 h after the injection of gonadotropic hormone. Light large cells have one or often two nucleus-containing big nucleoli, in their cytoplasm there are numerous vesicles, a well-developed Golgi apparatus, other organelles and lysosomal bodies. Some other cells are filled with many large vacuoles of different density, dense bodies and vesicles. Cells of another type which are in the majority show an unusually active structure reflecting the function of synthesis. The more prominent nucleolus is associated to clumps of chromatin. Their apical cytoplasm is filled by a structure related to absorption. The whole remaining part of their cytoplasm is covered with a very extensive Golgi apparatus and a very well developed granular endoplasmic reticulum. The extremely enlarged cisternae of this reticulum were found to be very closely applied to the basal cell membrane. There is a flocculent material inside the cisternae. Similar material is observed in the extracellular medium under the basal membrane. The epithelium seems normal 10 h after the injection of hormone, but large light cells make up the majority of them.
Comparative study of Gartner’s duct in the camel
Authors: Shehata Ramzy
Published: February 2009

Gartner’s duct is fairly constant in the camel, especially in young animals. It contains fluid secretion, yellowish translucent and viscid in character. Secondary coagulation of the secretion occurs on standing, and so becomes gelatinous. The ducts were histologically studied and glandular acini were found opening in them. An explanation of the manner of formation of Gartner’s duct cyst is suggested. Gartner’s duct may be a functioning accessory gland of the female sexual apparatus in the camel.
Ultrastructure of the capsule of the rabbit adrenal gland
Authors: Rossouw D.J. , Chase C.C.
Published: February 2009

The capsule of the normal rabbit adrenal gland was examined with the electron microscope, and three layers are described. The outermost layer consists of collagen and elastic fibrillae, with cytoplasmic processes of fibroblasts in between. Myofibroblasts with parallel cytoplasmic filaments, dense bodies at the inner surface of the plasma membrane and an irregular nuclear outline were seen in the middle layer. The presence of unmyelinated nerves and an axon terminal near to the myofibroblasts of the middle layer raised the possibility of innervation of these cells which could have a contractile function. The basal lamina of the fenestrated capillaries in the inner vascular layer is occasionally fused with that of the outer zona glomerulosa, suggesting a probable route for blood supply and secretion.
Energetische Verquellung und Lyse der Mitochondrien
Authors: Faller A.
Published: February 2009

Bt avitaminosis presents a typical example of energetic mitochondrial degeneration. The alterations – swelling and lysis of mitochondria – are accompanied by dilatation with formation of megamitochondria, by appearance of blebs and tearings of the mitochondrial membranes, by progressive fading of the matrix, by swelling of the mitochondrial membranes with lysis of the cristae advancing from centre towards periphery, by vacuolar transformation of the cell and by development of onionoid bodies (corpora cepiformia).
Ultrastructure of the liver cells in Salamandra salamandra (L.) in the end of Winter
Authors: Mişcalencu Dumitru , Iordăchel Mari Caloianu , Mailat Florica , Mihăescu Grigore , Untu Constanţa
Published: February 2009

Following hibernation, most salamander liver cells undergo alterations. The liver cells containing the structure of their active period present a normal nucleus, glycogen granules disseminated throughout the entire cytoplasm and granular mitochondria with several peripheral cristae. Most cells, however, possess altered mitochondria, transformed into electron-dense masses, or clear vesicles with the possibility of digesting the ambient organelles. Other cells have clear vacuoles with similar digestive possibilities. The endoplasmic reticulum is poorly represented in the liver cells that have suffered advanced alteration. The nucleus of these cells is homogeneously granular. The cytoplasm is populated by electron-dense bodies and lipid vacuoles. The nucleolemma and plasmalemma are thickened. The pigmented cells, altered concomitantly with the liver cells, contain granular aggregates. Some of the pigmented cells exhibit electron-clear formations similar to the reflecting platelets of the iridocytes of the integument of lower vertebrates.
Influence of extrinsic factors on the development of the articular system
Authors: Ruano-Gil D. , Nardi-Vilardaga J. , Tejedo-Mateu A.
Published: February 2009

In the present study, the results obtained after embryonic movements were paralyzed are described. Paralysis was produced by succinylcholine administered to chicken embryos during Hamburger-Hamilton’s stages 25–29. The study of microscopic sections across all the articulations emphasize the absence of articular cavity formation. The cavities were replaced by a non-differentiated mass of mes-enchymatous tissue. Regression of articular cavities and para-articular structures was noted in already formed embryos. Contrary to the opinion sustained by some authors, modifications on the articular surfaces were not produced. All of these data, reveal the importance of embryonic movements in articulation formation and conservation.
The cephalic arterial system in carnivores, with special reference to the systematic classification
Authors: Bugge J.
Published: February 2009

The cephalic arterial pattern in 53 fissipeds, representing all the classical families, is described on the basis of corrosion casts prepared by means of a special plastic injection and corrosion technique. The results are discussed on an ontogenetic and phylogenetic basis and related to current theories on the systematic classification of fissipeds at a higher taxonomic level (infraorders or superfamilies). In this respect, especially the systematic position of the canids and hyaenids in relation to the felids is discussed, the greatest importance being attached to the contribution of the external carotid artery system to the intracranial circulation. Also the very specific cephalic arterial pattern in the herpestines, one of the two viverrid subfamilies studied, is emphasized.
A quantitative histological study of the aortic nerve and the aortic body in the buffalo (Bubalus bubalis)
Authors: Prakash Prem , Rao G.S.
Published: February 2009

In the buffalo, the left aortic nerve ramifies in the periarterial connective tissue between the ventral surface of the aortic arch and the truncus pulmonalis. The right aortic nerve ramifies over the dorsal and right aspects of the aorta ascendens near its origin. The histograms of myelinated fibres of both left and right aortic nerve are distinctly unimodal with a peak around 4–6 μm (64.2–67.8%). The left aortic body is situated in the periarterial connective tissue between the ventral surface of the aortic arch and the truncus pulmonalis, while the right aortic body is located in the tunica adventitia of the dorsal and right aspects of the aorta ascendens near its origin. The greatest sagittal section area of the left aortic body is 0.102 ± 0.009 mm2 and that of the right aortic body is 0.041 ± 0.002 mm2. The organ is highly vascular. The mean size of the glomus cells from the left aortic body is 7.68 ± 0.9 μm × 9.37 ± 0.13 μm (short diameter × long diameter), whereas thecorrespondingvaluefor the right aortic body is 7.84 ± 0.14 μm × 9.86 ± 0.21 μm; and their density values are (11,417 ± 301.7 )/mm2 and (9,839 ± 213.3)/mm2 respectively.
Effects of zinc deficiency on the chick embryo blastoderm
Authors: Iñiguez Carlos , Casas Jesús , Carreres José
Published: February 2009

A technique which permits the in vitro study of zinc deficiency in early embryos of Gallus domesticus is described using dithizone as a chelating agent. Zinc deficiency produces specific and constant lesions which are more severe as the embryo is cultivated in more early stages. The most serious alterations affect growth in general and the differentiation of the nervous system and mesoderm.
Some observations on the morphology of the newt liver at different stages of inanition
Authors: Hightower J.A. , Haar J.L.
Published: February 2009

It was the primary objective of this investigation to observe morphological changes in the hepatic parenchyma or perihepatic subcapsular region which occurred as a result of inanition and to determine when these changes took place. We also wanted to study the effect of starvation on the peripheral blood cells. We were particularly interested in obtaining this information because a relatively large percentage of animals that we obtain from the wild or commercial suppliers do not eat well for 2 weeks or longer after arrival in the laboratory; therefore, we were interested in determining whether food deprivation had any effects on liver morphology and blood cell populations which would prevent us from carrying out studies which were not initiated immediately after the animals had been captured. In order to accomplish these objectives, animals were weighed at various time intervals of starvation and morphometric analyses were performed on light and electron micrographs of hepatic tissue from newts which were starved from 2 to 16 weeks before being sacrificed. Analyses of the results revealed that (1) during the first 2 weeks of starvation of the newt a 17% loss of body weight occurred, but that rate of weight loss diminished as the time of starvation increased, and (2) starvation induced the fragmentation of liver cells thus depleting the lipid, glycogen and mitochondrial content of the liver and creating larger and larger sinusoids as starvation progressed; glycogen granules were quickly and inexorably lost from hepatocyte cytoplasm, but the rate of lipid and mitochondrial loss was much slower. A comparison of the number of mitochondria per unit volume of hepatocyte cytoplasm in control and starved newts suggested that those mitochondria that were present at the 8-week time interval increased in size until the largest were lysed between 8 and 16 weeks of starvation. The substantial changes that occur in the hepatic parenchyma during the first weeks of starvation strongly indicate that newts which are not feeding well in the laboratory should be identified and eliminated from studies involving the liver and its metabolism.
A mechanism for passive mandibular depression
Authors: Roberts David
Published: February 2009

Retention of a retromandibular space has necessitated developing a system of mandibular protrusion in hominid species. It is possible that mandibular protrusion can be effected by a single muscle – the lateral pterygoid – and the motion controlled by the excentrically placed mandibular suspensory ligaments. The elasticity of the ligaments produces an integrity maintenance force between the articular condyle and eminence which is normally of minimal size. Excessive craniofacial flexion, or the retention of a juvenile configuration of the mandible, could result in increasing this integrity maintenance force and cause crepitation and clicking. Adjustment of the ligaments could reduce these pathological manifestations.
Die Vaskularisation des Plexus submucosus externus (Schabadasch) und des Plexus submucosus internus (Meissner) im Dünndarm von Schwein und Katze
Authors: Stach Werner
Published: February 2009

Each ganglion of the plexus Schabadasch is supplied by a specific periganglionic capillary network. Within the plexus Meissner, several ganglia are connected to circulation areas. The communicating branches of the plexus Schabadasch have their own capillary system; as to the plexus Meissner, this is valid for the cat only. The results allow to conclude that the centres of the intramural nervous system of the intestinal wall are equipped with a preferred and self-acting vascularization.
Regeneration of ankylosed teeth in the adult frog premaxilla
Authors: Howes Robert I.
Published: February 2009

The relationship between the ankylosed amphibian tooth and regeneration of a jaw segment was studied. A section of the premaxilla was removed in 95 young leopard frogs. Subsequent wound healing was observed at intervals of 0–180 days. The dental lamina formed new teeth and by 90 days, teeth in varying stages of development could be seen extending across the wound segment. Teeth within the wound grew to normal size and shape and were replaced by their successors without support of underlying jaw bone which grew in later and often was incomplete.
Comparative morphometric analysis of vermilion border epithelium and lip epidermis
Authors: Lanfranchi H.E. , de Rey B.M.
Published: February 2009

A comparative morphometric study of lip epithelia in cattle, rats, and humans was undertaken using stereological techniques. Vermilion border and skin specimens of cattle, rats and humans were processed under standardized conditions for light microscopic observation. Stereological techniques were employed to obtain volumetric densities of each epithelial layer. The results obtained show that although the absolute volume of each epithelial stratum of the vermilion border and of the skin varies markedly in the different species studied, the relative volume of these strata in relation to the entire epithelium is similar in all epithelia.
Premature death of Purkinje cells following low-level X-ray irradiation during embryonic development
Authors: Das Gopal D.
Published: February 2009

Rat embryos were exposed to 170 r of X-ray irradiation on day 15 or 18 of gestation, and sacrificed when they reached the postnatal age of 30 days. In the cerebella of these animals, normal-looking and atrophied Purkinje cells were studied and compared with those observed in the cerebellum of the normal animals. The normal animals did not show presence of any atrophied Purkinje cells, but the X-ray-irradiated animals showed a lesser number of Purkinje cells and many atrophied Purkinje cells. In the cerebellum of animals that were X-ray-irradiated on day 15 of gestation, the number of Purkinje cells was only 32% of those in the normal cerebellum, and in those that received X-ray irradiation on day 18 of embryogenesis there were about 95.5% as many Purkinje cells as in the normal cerebellum. But, in the cerebella of animals in the latter group there were two to three times more atrophied Purkinje cells than in the cerebella of animals in the former group. These findings are discussed in terms of lasting effects of low-level X-ray irradiation in the form of premature atrophy and death of the Purkinje cells.
Ultrastructural morphometric study on developing acinar cells of the rat pancreas and parotid gland
Authors: Ferraz de Carvalho Claudio A. , Laurindo Francisco R.M. , Taga Romio , Sesso Antonio
Published: February 2009

The fraction of cellular volume occupied by the cytoplasm has been assessed by point-counting volumetry in 0.5-μm araldite sections. Measurement of the transection radius of the nuclei of acinar cells allowed the assessment of the mean nuclear volume according to the method of Bach. With these data, the cytoplasm volume was calculated in cubic micrometers. Ultrastructural morphometric data were obtained by means of superimposing on the electron photomicrographies (× 21,000 or × 28,500) a test system of 84 evenly spaced segments according to Weibel et al. The analysis of the values obtained for the pancreas and parotid gland allowed for the supposition that the process of maturation in the rat, either for the pancreas or the parotid gland, occurs simultaneously with the mitotic process, this last being held as the predominating one in the first 3–4 postnatal weeks. The cytodifferentiation process becomes more marked in the last phases studied and on the 40th day it already shows parameters held as similar to those of the adult animal.
Embryonic development of the pineal gland of the chicken (Gallus gallus)
Authors: Calvo J. , Boya J.
Published: February 2009

A study of the embryonic development of the pineal gland of the chicken was performed with the optical microscope. The time of apparition of the first outline, as a derivative of the roof of the third ventricle, was fixed at 3 days. The major portion of the pineal parenchyma is derived from the frontal wall of the outline. All the vesicles and follicles were formed by solid mammilliform projections which subsequently presented a central lumen. In no case was a communication of the follicular cavities with the pineal recess observed. Three categories of vesicles or follicles can be distinguished according to their origin.
Seasonal histological changes in the gonads, thyroid and adrenal of the Canada goose (Branta canadensis interior)
Authors: Mori John G. , George J.C.
Published: February 2009

Cyclic histological changes in the testis, ovary, thyroid and adrenal of the North American eastern prairie population of Canada geese (Branta canadensis interior) breeding in Ft. Churchill (Manitoba, Canada) and wintering in the Swan Lake refuge in Missouri (USA) were studied. The investigation was carried out during the following six periods of the yearly life cycle. Phase 1: pre-spring migration at Swan Lake (early March); phase 2: post-spring migration at Ft. Churchill (early May); phase 3: breeding (early June); phase 4: moult (early August); phase 5: pre-fall migration (early September); phase 6: post-fall migration at Swan Lake (mid-October). The development of the testis and the initiation of spermatogenesis up to the formation of secondary spermatocytes was begun in phase 1. All stages of spermatogenesis, including the formation of spermatids and spermatozoa, were reached by the end of phase 2 and remained so through most part of phase 3. The weight of testis recorded was highest in phases 2 and 3. Testicular regression characterized by progressive loss in weight, reduction of spermatogonia in the tubules and appearance of sudanophilic material in the intersititium commenced in phase 4 and lasted through phases 5 and 6. Though the initiation of ovarian development probably started in phase 1, the ovary weighed the highest in phase 2. At this time, the ovary contained numerous maturing ova in different stages of development and lipoidal atresia. Lipoidal atresia was more prominent among young small ova. The larger maturing ova were characterized by a more distinct granulosa layer around the oocyte. Numerous sudanophilic interstitial cells were present scattered throughout the ovarian stroma. Atretic follicles and scars from discharged follicles were found in all the phases. The thyroid showed a significant increase in weight during moult (phase 4). No marked histological changes were discernible in all the phases. The increase in weight during moult is
Cerebral asymmetry in Old World monkeys
Authors: Folk Dean
Published: February 2009

A photogrammetric computer analysis of 88 endocasts, representing 8 genera of Old World monkeys, reveals cortical asymmetry in lengths of the Sylvian fissure, superior temporal sulcus, lateral edge of the orbit and distance separating rectus and arcuate sulci. Hypothetical expansion of left prefrontal and parietal integration cortices explains these asymmetries.
Contribution to the knowledge of the brain in the newborn
Authors: Hadžiselimović H. , Čuš M. , Dilberović F.
Published: February 2009

On 50 brains of newborns of either sex, the exterior and interior morphology was studied. The exterior morphology ofthe brain was conformable to the configuration ofthe skull. The insula is relatively large, but extremely inadequately grooved. The subcortical masses are well pronounced but there is in general a very slight difference between the white and gray matter of the brain. The convolutions and grooves of the cerebellum are very distinctly marked, the nucleus dentatus is large and white matter is prevalent. The brain stem is rather well formed, distinctly plastic, this being particularly true for the region of the rhomboid fossa and medulla oblongata.
Pre-natal innervation of the human female genital tract
Authors: Olfat Ahmed , Rahman SawsanAbdel
Published: February 2009

In the human fetus of 14 weeks, ganglia on either sides of the Müllerian utero-vaginal canal contained two types of cells. In the 16th week, axons invaded the basal zone of the stratified squamous epithelium at the sides of the upper vagina. In the 20th week, vesicular nuclei typified the large neurons in the midportion of the cervico-vaginal ganglion. During the 22nd week, capsulated ganglia invaded the wall of the upper vagina forming three concentrically disposed strata. Non-capsulated clusters invaded its lamina propria. At the 24th week, axons were shaded after reaching the superficial zone of the stratified vaginal epithelium. In the 28th week, satellites surrounded the mature neurons and sheath cells enveloped the axons. Ganglia invaded the splitted muscle layer of the upper vagina at 30 weeks. Intraepithelial fibres invaded the whole thickness of the endometrium, the columnar epithelium of the cervix and uterine tube at 40 weeks. Nerve cells were detected among the basal epithelial cells of the lower vagina and its subepithelial plexus.
Origin and function of ‘rod-like structures’ in mitochondria
Authors: Heine H. , Schaeg G.
Published: February 2009

Both organ culture (chorioallantoic membrane) of striped muscle from mouse diapharagm and freeze-drying of myocardial cells presented very characteristic structures in mitochondria. The organ culture evidence ‘rod-like structures’ in the intracristal spaces of the cristae mitochondriales. It is believed that these structures are the central apparatus responsible for mitochondrial division. On the other hand, the freeze-dried mitochondria presented neither intracristal spaces nor a space in the outer mitochondrial membrane. Because these spaces appeared only after fixation and dehydration, it is discussed if they are really artifacts. The mitochondrial cristae appearing as united structures after the freeze-drying process have been compared to the rod-like structures appearing intracristally after organ culture and conventional preparation techniques.
Topography of the dopamine neurons in the arcuate nucleus of the mouse hypothalamus
Authors: Nishizuka Masako
Published: February 2009

The distribution of the dopamine (DA) cell bodies was elucidated within the mouse arcuate nucleus by fluorescence histochemistry. The arcuate nucleus was divided into five regions; heterogeneity in distribution and different amounts of DA among the regional areas were demonstrated. The DA cell bodies containing a large amount of DA, observable even in the arcuate nucleus of the intact mice, distributed in the medial areas of the anterior-central and the middle-central regions and in the dorsal area of the posterior-central region. On the other hand, those containing probably a small amount of DA distributed in the medial area of the rostral region and in the ventral areas of the anterior-central and middle-central regions. They were not observed in the intact mice, but found in the mice treated with nialamide plus α-methyldopa. No DA cells were found in the caudal region.
Comparative light- and electron-microscopical study of the normal adenohypophysis in the human
Authors: Ciocca Daniel R. , Rodriguez Esteban M. , Cuello Carlos A.
Published: February 2009

The pars distalis of 1 girl and of 3 sexually mature women was studied. The glands were dissected out and fixed within a period of 30 min following death; in the aldehyde fixative, each gland was systematically divided into ten pieces. Before fixation in osmium tetroxide, each piece was again divided into several blocks. At least 60 blocks were obtained from each gland. Semi-thin sections obtained from all the blocks were stained and studied under the light microscope. Ultrathin sections were obtained from selected blocks. Under the light microscope, 6 types of secretory cells and 2 types of non-secretory cells were characterized. At the ultrastructural level, 7 types of granulated cells and 2 types of non-granulated cells were distinguished. The range of the granule size for each type of secretory cell was determined by applying a mathematical model and a computer program that corrected the size distribution curve in such a way that only the diameter of the equatorial sections of the granules, that is the real granule sizes, was recorded. By comparing the observations made in the ultrastructural study with those performed in adjacent semi-thin sections it was possible to correlate the cell types characterized ultra-structurally with those distinguished under the light microscope. In addition, the study of the semi-thin sections made it possible to quantitatively analyze the different cell types, while the ultrastructural characteristics suggested the probable functional role of each of these cell types.
Ultrastructure of the nerve cells and fibres in the urinary bladder wall of the cat
Authors: Fehér Erzsébet , Csány K. , Vajda J.
Published: February 2009

The nerve elements in the urinary bladder of the cat were studied by electron microscopy. According to their ultrastructure, nerve cell somata can be classified into three types: the large cells with a cytoplasm rich in organelles, several processes and numerous synaptic contacts on their surface; the cytoplasm contained 80- to 120-nm granulated vesicles. The second type is poor in cytoplasmic organelles and has very few processes and virtually no synaptic contacts on the soma. The third type contains numerous large 160- to 220-nm ‘neurosecretory’ vesicles in the cytoplasm. According to the morphology of the vesicle population, four types of nerve processes could be distinguished: Type a, with a dominant population of small (40–60 nm) agranular vesicles. These are thought to be sacral parasympathetic fibres. Type b, with small (40–60 nm) granular vesicles, which may be the noradrenergic sympathetic fibres. Type c, with 80- to 120-nm granulated vesicles, probably of local origin. Type d, with large 160- to 220-nm ‘neurosecretory’ vesicles also of local origin. Different types of nerve fibres are converging on the local nerve cells. This suggests that the local circuits can play an important role in coordinating the function of the bladder. Therefore, ganglia may be considered as an elementary functional unit.
Stress and wound healing
Authors: Cohen Irene
Published: February 2009

An experiment was performed to compare the effects of stressors – cold, heat and noise – on primary wound activity (i.e., wound closure in the first 24 h after wound infliction) and on rate of healing in mice. A significant correlation was found between reduced primary wound activity and a faster rate of healing. Conversely, a correlation was found between relatively greater primary wound activity and a slower rate of healing. A possible explanation of this correlation is a compensatory mechanism inherent to the skin healing process. This mechanism is visualized as (1) stress exposure affecting the skin by (a) causing it to become thinner and tauter and (b) causing it to have less elastic recoil; therefore, (2) when a square wound is produced in stressed skin, (a) the wound does not recoil readily or gapes soon after cutting and (b) a longer wound perimeter results. Because there is evidence that rate of healing is governed by cells on the wound perimeter, the greater the perimeter, the greater the number of cells that will undergo rapid mitosis and the faster will be the rate of healing. Therefore, stressed skin will heal at a faster rate, compensating for the loss of elasticity and cellular depletion caused by stress. This study is of interest to anthropology because it deals with dynamic adaptation, trying to grasp the meaning of the elusive endocrine interface between environmental stimulation and a measurable physical entity like healing. This work may have revealed a functional complex that is common to the healing of all mammalian skin, whereby retarding effects of stress on the healing process are obviated.
Strain and sex differences in the rat brain
Authors: Yanai Joseph
Published: February 2009

The brains of female and male Wistar (W) rats were larger than the brains of Long-Evans (LE) rats at all ages and males had larger brains than females (p < 0.001). These differences did not correlate with differences in body weight. Brains of female and male LE and W rats aged 60 days (n = 48) were perfused with 10% neutral formalin and cut and stained with hematoxylin and eosin. Matching sagittal sections were selected for the study of the cerebellum, hippocampus and the olfactory bulbs. Brains from a similar group of 48 animals were prepared according to the Golgi-Cox method and were used for the study of Purkinje cells. Males had a 5.7% larger cerebellar area than females (p < 0.001). This difference was mostly due to a 6.1 % difference in the area of the molecular layer and a 6.2% difference in the granule cell layer (p < 0.001). Males also had more granule cells (8.1%), p < 0.05) and Purkinje cells (7.2%, p < 0.05) than females. The strains were similar in the area of the cerebellum, but LE had more Purkinje cells (9.6%, p < 0.01), packed more densely (11.1%, p < 0.01) than W cells. The results of the Golgi preparation suggest that the dendritic tree of the Purkinje cells was larger in the LE strain (10.5%, p < 0.05). There were no sex differences for the hippocampus and the olfactory bulbs. The area of the hippocampus did not differ between strains but W had a longer and thus thinner granule cell layer (15.2%, p < 0.001). The hippocampal granule cells were packed more densely in W strain (8.9%), p < 0.05). The olfactory bulb granule cell layer of W rats was larger than that of LE rats (14.9%o, p < 0.05). Such anatomical differences may be correlated in subsequent studies with behavioral differences. Indeed, there are indications that the strain LE which possesses a greater number and larger Purkinje cells also perform better in motor tasks.
Cytological changes in the testes of vitamin-A-deficient rats
Authors: Mitranond Viroj , Sobhon Prasert , Tosukhowong Pichit , Chindaduangrat Wanna
Published: February 2009

Vitamin A deficiency was induced in young adult male rats by feeding them with a synthetic vitamin-A-deficient diet. The histology of their testes was examined periodically from 1 to 20 days following the point where the animals ceased to gain weight. The earliest sign of histological change in the seminiferious tubules, which occurred at day 3, was the sloughing of spermatids and spermatocytes into the lumina of the seminiferous tubules. Pyknotic cells were seen throughout the epithelium in a significant number beginning at day 4 or 5. Most of them were dead spermatocytes and early spermatids. Abnormal multinucleate giant cells appeared during days 6 and 8, and were thought to be abnormal spermatids which failed to complete cytoplasmic division and further differentiation into spermatozoa; eventually they degenerated. Quantitation of germinal cells in the tubules revealed that the number of spermatids decreased sharply between days 2 and 8, and reached zero level at day 10 after the animals ceased to grow. The number of spermatocytes decreased rapidly between days 5 and 12, and the rate of their decrease was relatively slow during the periods preceding and following this interval. Few spermatocytes remained in the tubules at day 20. In comparison, the decrease of spermatogonia was more gradual. At the end of the experiment, the number of spermatogonia in each tubule was about one fourth of that detected at the time when the animals ceased to grow. It was thought that the sloughing and the disintegration of the spermatocytes and spermatids were major factors responsible for their rapid disappearance from the tubules, and that fast dividing and differentiating cells like spermatocytes and spermatids were more vulnerable to vitamin A deficiency than spermatogonia.
Spinous leafy nerve endings in the feline stomach wall
Authors: Rodrigo José , Hernández Carlos J. , De Felipe Javier , Pérez Antón J.A. , Espinosa F.
Published: February 2009

The Champy-Maillet ZIO technique has been applied to the study of the muscular tunic of the stomach..In the corpus and antrum pyloricum some nerve fibres end in non-capsulated expansions owning thorn-like protrusions. Their morphology is studied and a possibly functional sensory significance is proposed, on the basis of previous experimental results.
Die Wirkung einer Unterbrechung der Dottersackzirkulation auf die Ultrastruktur des Dottersacks und die Entwicklung des Fetus bei der Ratte
Authors: Franke H.
Published: February 2009

The effect of an interruption of the yolk sac circulation on the rat visceral yolk sac and the development of the fetoplacental unit was examined in the last third of pregnancy. The yolk sac ischaemia was induced by ligating the blood vessels of the yolk sac stalk which connect the vitelline circulation with that of the fetus. A 3-hour ligature caused an extensive swelling of most cell organelles in the epithelial cells and in the capillary endothelia of the yolk sac. Other structural changes were indicative of a cessation of pinocytosis. A 6-hour ligature resulted in a common ncrease of cell swelling and in a beginning disintegration of the endothelial cells lining the vitelline capillaries. A 15-hour ligature caused severe ultrastructural cell lesions and macroscopical alterations suggestive of a progressive necrosis of the entire yolk sac tissue. Of special significance was the regular finding of a nearly complete loss of the amniotic fluid and the death of the fetus, although the maternal blood flow appeared to be still intact in the placenta.
Effect of cyproterone acetate on the reproductive system of the female rat
Authors: Arya Manjula , Gupta Somnath , Dixit V.P.
Published: February 2009

Effects of cyproterone acetate, a synthetic steroidal compound, on the reproductive organs of female rats have been investigated. This agent caused reduction of ovarian weights indicative of suppression of pituitary gonadotrophins. Oestrogenic nature of cyproterone acetate was investigated in intact and ovariectomized rats taking uterine weight and vaginal keratinization as an index of oestrogenicity. Cyproterone acetate in ovariectomized animals induced vaginal keratinization and increased the uterine weights. These effects were parallel to the effect of oestradiol dipropionate in ovariectomized animals, thus indicating oestrogenic activity of cyproterone acetate. We may conclude that the above compound caused antifertility effects due to its oestrogenic nature at the dose level of 2 mg/alternate day in rats when the compound was administered subcutaneously.
Changes in laser-irradiated retina in the first 24 h after irradiation
Authors: Yew David T. , Wong C.L. , Chan Yau-wa
Published: February 2009

Retinas of laser-irradiated mice were studied in the first 24 h after irradiation. Decrease in Na+ and K+ concentrations and in phagosome number and increase in pyknotic cells were observed several hours after irradiation.
Histochemical study on the innervation of the heart of Pteropus giganteus
Authors: Mathur R. , Gupta R.B. , Mathur A.
Published: February 2009

Histochemical study of the innervation of the heart of the Indian flying fox Pteropus giganteus has been made using Coupland and Holmes’ technique for chohnesterase. Distribution of nerve plexuses in the heart wall has been described. Nerve cells, nerve endings and various types of synapses have been reported. Specialized muscle fibres are found to contain less nerve fibres and conduction of the impulse of contraction is reported to take place through muscle fibres.