bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reproduction of the canyon bat, Pipistrellus hesperus, in Southwestern United States
Authors: Krutzsch Philip H. 
Published: February 2005

AbstractThe reproductive biology of the bat Pipistrellus hesperus was investigated histologically using animals obtained from nature at monthly intervals throughout the year.The female shows proestrous morphological changes in late summer and autumn, which continue until early spring. Insemination is probably effected several times during proestrous, since both sexes are intermittently active throughout this period (August‐April). Permanent arousal from torpor and return to normal metabolism in the spring results in ovulation. Both ovaries are functional and both uterine horns may be utilized. P. hesperus is monestrous; two young per bat is usual.The male spermatogenic cycle is initiated in late June and the first sperm are available for ejaculation in September. Some sperm remain in the seminiferous tubules until early March. The epididymides also serve in sperm storage with the caput emptied by late February and the cauda in April. Leydig cells are largely nonsecretory from March through July, a few are secretory in August and most are secretory in September and October. Active cells gradually decline in number until few are secretory in late March.Accessory sex glands are functionally cyclic: they are small from April through August, hypertrophy in September, and gradually involute to the resting stage through March, to achieve total involution in April.The penis, similar in structure to that of other vespertilionids, is thought specialized to insure effective insemination.
Quantitative morphology and carbohydrate histochemistry of the mouse submandibular gland following prepubertal castration
Authors: Smith Richard J. , Frommer Jack 
Published: February 2005

AbstractThe endocrinologic basis for morphological and biochemical sex differences in the mouse submandibular gland have not been clarified. Previous studies have emphasized the maintenance of glandular differences in adult animals, rather than considering the factors responsible for their developmental etiology. Male CD‐1 mice were castrated at intervals between 10 and 50 days of age and killed at 100 days. The quantitative development of granular tubules and the carbohydrate histochemistry of the submandibular glands were compared to untreated males and females. The area of granular tubules increased with age at castration. Nested analysis of variance indicated significant differences among treatments and among sections within individual glands. No group of castrated males had a greater development of tubules than untreated females. Carbohydrate histochemistry demonstrated an increase in carboxylated mucosubstances in the acinar cells and granular tubule cells of castrated animals.
Estrogen and antagonist‐induced structural changes in the cervico‐vaginal epithelium of immature rats
Authors: Anderson Winston A. , Kang Yuan H. 
Published: February 2005

AbstractEstrogen enhances proliferation and keratin formation in the cervico‐vaginal epithelium of immature rats, whereas the estrogen antagonist, CI‐628 (Parke‐Davis), represses mitosis and induces mucinogenesis. Combinations of antagonist and estrogen allow differentiation of an epithelium composed of both keratin‐forming and mucous cells. Both estrogen and antagonist induce synthesis of a cervico‐vaginal endogenous peroxidase in the intermediate and superficial layers of the epithelium. The secreted vaginal mucus of antagonisttreated animals stains intensely for exogenous peroxidase.
Macrophage‐lymphocyte clusters in lymph nodes: A possible substrate for cellular interactions in the immune response
Authors: Farr Andrew G. , De Bruyn Peter P. H. 
Published: February 2005

AbstractThe lumens of the lymphatic sinuses in lymph nodes are traversed by fibrocellular trabeculae. Joined to these trabeculae were macrophages, which formed cell clusters with lymphocytes. It is proposed, based on structural similarities, that these cell clusters are the equivalent in vivo to those seen during primary and secondary immune responses in vitro. These intraluminal macrophages were located in the path of lymph‐borne antigen, as well as in the path of newly formed and recirculating lymphocytes in sinuses. This would facilitate the possible interaction between macrophage‐associated antigen and antigenreactive lymphoid cells. The attachment of numerous lymphocytes to the surfaces of macrophages and the resulting cell clusters aslo afford increased opportunities for lymphocyte‐lymphocyte contact.
Vinblastine‐induced microtubular paracrystals in prolactin cells of anterior pituitary gland of lactating rats
Authors: Shiino Mastaka , Rennels Edward G. 
Published: February 2005

AbstractVinblastine sulfate in physiological saline was injected directly into the pituitary glands of lactating rats. Injections were made through the ear canal using a syringe equipped with a 24‐gauge needle. The animals were killed at 2, 4, or 6 hours after the injections. When the anterior pituitary glands were examined by electron microscopy, many microtubular paracrystalline deposits were seen in the prolactin and growth hormone cells. The usual cytoplasmic microtubules and microfilaments were not seen in the cytoplasm of these cells. Granular extrusion (exocytosis) was markedly depressed, and an accumulation of secretory granules was definitely observed in the prolactin cells after the administration of vinblastine.
Presence of multiple centrioles in a rhesus macaque oocyte matured in vitro
Authors: Zamboni Luciano 
Published: February 2005

AbstractThis report demonstrates for the first time the presence of centrioles in a rhesus macaque oocyte which had attained meiotic maturation in culture. The exceptional presence of centrioles in this oocyte was associated with anomalous patterns of chromosomal and spindle organization.
Age‐dependent sensitivity of basal cells in mouse vaginal epithelium towards the differentiating action of estrogen
Authors: Galand Paul , Rognoni Jean‐Baptiste 
Published: February 2005

AbstractFollowing ovariectomy, the vaginal epithelium of the mouse is reduced to two layers of cells, the basal layer that constitutes the germinative compartment and a surface layer. Under estrogenic influence, this tissue undergoes keratinization at the expense of basal cells only. The initially superficial cells are progressively sloughed, without taking part in the cornification process. We have shown previously that within the first 12 hours after estrogen administration (that is, before any change in mitotic activity is detected) an intermediate layer of cells is formed. Thus, a migratory process is induced, which leads to a very rapid redistribution of basal cells into two layers. The purpose of the present work was to test whether the sensitivity of basal cells towards this initial differentiating influence of estrogen depends on cellular age. Therefore, ovariectomized animals were injected with 3H‐thymidine, treated with a single injection of 17‐β‐estradiol benzoate (1 μg/animal) at time intervals of 10, 22, 34, 48 or 60 hours, and finally killed 12 hours thereafter. Autoradiography was used to measure the degree of participation of the labeled cells in the formation of the intermediate layer (at 12 hours) as a function of their age at the moment of estradiol injection, as measured by the delay between labeling and estrogen administration. The results indicate that the susceptibility of basal cells to estrogen‐induced migration behavior (at 12 hours) increases more or less exponentially with cellular age.
Establishment of a TSH‐releasing‐hormone‐secreting cell line from the area cerebrovasculosa of an anencephalic foetus
Authors: Ishikawa Hiroshi , Nagayama Takahisa , Kato Chieko , Niizuma Katsuhiko 
Published: February 2005

AbstractA cell line was established from the area cerebrovasculosa of an anencephalic foetus, five types of cells were identified in this cell line, and medium conditioned by this cell line caused strong TSH‐secreting activity in cultured human pituitary cells.
Postnatal differentiation of leydig cells in the rabbit testis
Authors: Gondos Bernard , Renston Richard H. , Goldstein David A. 
Published: February 2005

AbstractAfter the gradual disappearance of fetal Leydig cells in the first week after birth, the interstitial tissue of the rabbit testis is composed principally of undifferentiated mesenchymal cells between one and five weeks of age. Also present during this time are scattered partially differentiated cells with ovalshaped nuclei, prominent nucleoli and abundant cytoplasm. These cells exhibit some of the cytoplasmic features of steroid‐secreting cells, but extensive development of smooth endoplasmic reticulum and the grouped perivascular arrangement characteristic of fully differentiated Leydig cells are not present. The latter features appear at five weeks of age, indicating the formation of mature Leydig cells at that time. By seven weeks, the bulk of the interstitial tissue consists of Leydig cell aggregates, typical of the appearance in adult testis. Since spermatogonial mitoses first appear at seven to eight weeks of age, the findings indicate that Leydig cell differentiation precedes the onset of spermatogenesis.
The onset of testicular differentiation in the rat: An ultrastructural study
Authors: Merchant‐Larios Horacio 
Published: February 2005

AbstractThe structure of developing rat testes was studied by light and electron microscopy. Ultrastructural differentiation of Sertoli and Leydig cells was followed from 14 days of gestation through birth. Specialized morphology in Sertoli cells was first seen at 16 days of gestation. In these cells the rough endoplasmic reticulum increased and became organized as numerous short cisternae loaded with a homogenous material. Typical Leydig cells were found among the stromal cells, around day 17 of gestation.There is good correlation between the time of appearance of ultrastructural specialization and published data on secretory capacity of the fetal testes, in respect to the inhibition and differentiation of the Müllerian and Wolffian ducts.
The effect of frozen ovarian autografts on compensatory ovulation and steroid production in unilaterally ovariectomized rats
Authors: Chihal H. J. Weems , Stone S. C. , Peppler R. D. 
Published: February 2005

AbstractIn the present study rats were unilaterally ovariectomized (ULO) and the surgically removed ovary was frozen for 13 days. After allowing the remaining ovary to compensate with respect to number of ova shed, the frozen graft was thawed and transplanted subcutaneously to determine the effect on ovulation number, cycle length, uterine weight, ovarian weight and plasma levels of estradiol‐17 β (E2) and progesterone.Rats ULO at 45 days of age, which received an autograft 13 days later, had a decrease in the number of eggs shed as compared to control ULO rats (6.4 ± 0.8 vs. 11.1 ± 0.9 eggs, respectively) and a decrease in plasma E2 (14.5 ± 1.7 vs. 21.0 ± 1.5 pg/ml, respectively). No differences were observed in progesterone concentration, uterine weight, ovarian weight or cycle length. In contrast, rats ULO at 31 days of age, which received an autograft 13 days later, showed no differences in comparison to control ULO rats. Castrates which received ovarian autografts developed cycling vaginal smears and had increased E2 (31.9 ± 4.3 pg/ml) and decreased progesterone (18.3 ± 1.9 ng/ml) levels.Since ULO animals with autografts shed fewer ova, the present study demonstrates that the amount of ovarian tissue influences ovulation number either by utilization of gonadotropins or by an, as yet, undefined mechanism.
A comparative morphometric analysis of the effects of thyroxine and acth on the zona fasciculata of rat adrenal cortex
Authors: Moore N. A. , Boler R. Keith 
Published: February 2005

AbstractThe effects of thyroxine and ACTH on the ultrastructure of cells of the adrenal zona fasciculata were studied by morphometric analysis and compared by two‐way analysis of variance. The results indicate that the effects of thyroxine and ACTH are different and independent. The statistically significant differences in effect of thyroxine and ACTH are: thyroxine causes an increase in the volume fraction of mitochondria and a decrease in the volume fraction of endoplasmic reticulum independent of ACTH; thyroxine causes a decrease in surface density of mitochondria and endoplasmic reticulum in the absence of ACTH, but in the presence of ACTH this effect is moderated by an interaction of thyroxine and ACTH. There were no statistically significant effects of either thyroxine or ACTH on volume fraction or surface density of liposomes.
Prenatal development of the eye in the golden hamster
Authors: Jackson Caroline Goode 
Published: February 2005

AbstractPrenatal development of the eye in golden hamsters is described at the light microscopic level as twelve periods based on salient morphological features. Period one includes shallow and deepened optic sulci in the cephalic neural plate and closing prosencephalon. Period two shows V‐shaped prosencephalic evaginations, and Period three, bulbous vesicles. Contact of the retinal disc and lens placode at Period four precedes presumptive retinal invagination and lens pit formation during Period five. During Period six an open lens vesicle, precociously expanded dorsal and lateral optic cup regions and widespread optic fissure margins are evident. A spherical lens lumen, deepened optic cup and narrow optic fissure characterize Period seven. At Period eight posterior lens fibers are elongated, the optic cup is expanded ventrally, and optic fissure margins are juxtaposed or fusing. By Period nine the lens lumen is nearly or completely occluded, the optic fissure is essentially fused and axonal fibers are exiting from the globe. During Period ten corneal components are associated, axonal processes extend to the diencephalon, and lid folds cover more than half of the cornea. By Period eleven eyelids are fused. Anteriorly the pigmented epithelium is thickened and densely pigmented; outer and inner neuroblastic retinal layers are clearly distinguishable. Period twelve is marked by conspicuous anterior folds of pigmented epithelium; a relatively anuclear zone virtually separates outer and inner neuroblastic layers of the retina.
Proximal tubule tendrils: Fact or artefact
Authors: Bulger Ruth Ellen , Siegel Frances Lea , Pendergrass Robert 
Published: February 2005

AbstractTendrils have been reported to radiate from luminal surfaces of proximal tubules in rat kidneys by Andrews and Porter ('74) using scanning microscopy, but they were not seen by Bulger et al. ('74). In this study, the perfusion procedure of Andrews and Porter was re‐investigated. Tendrils were found only in regions which had characteristics of poor fixation. They were especially prominent if the perfusion pressure was purposely allowed to fall and subsequently increased to re‐expand the tubules. The tendrils could then be seen in all portions of the proximal convoluted tubule and not exclusively in the initial portion as previously reported.
Hydronephrosis in the mouse: The effects of the short‐ear gene, sex and ureteral vascular system
Authors: Wallace Margaret E. 
Published: February 2005

AbstractThe short‐ear gene in the mouse, se, affects a number of soft tissues; skeletal effects result in reduced body cavities. A high incidence of hydronephrosis in short‐ear genotypes has been ascribed to pressure on the lower ureter resulting from crowding of organs in the body cavity. This study concerns the ureteral vascular system as observed in 861 autopsies of mice of varying age, of the three short‐ear genotypes, drawn from ten stocks. Incidence and expression of hydronephrosis is greater in short‐ear males than in females, and the ratio between the two varies from one stock to another. This study seeks an explanation. Short‐ear genotypes have an abnormally high incidence of unusual ureteral veins, hydronephrosis being strongly associated with the more posterior ones. Ureteral veins most closely associated with hydronephrosis involve the renal, gonadal and iliac veins. The spermatic vein's more posterior position, compared with the ovarian, is strongly correlated with the sex difference in posterior ureteral venation and thus with the sex difference in incidence of hydronephrosis. Stocks are compared according to the amount of selection for fitness of shortear genotypes; there is a reduced incidence of hydronephrosis with selection, accompanied by fewer posterior ureteral veins. Age also affects hydronephrosis; its expression increases slightly with age, and the male sese progeny of young mothers appear to be particularly prone to hydronephrosis. Three skeletal mutants segregate; of these fidget, fi, causes a type of hydronephrosis differing some what from that caused by se..
Surface view of an injected human lung shortly before the fetus becomes viable
Authors: Boyden Edward A. 
Published: February 2005

AbstractThese figures of a silicon‐rubber‐injected fetal human lung illustrate the precocious development of filaments (future alveolar ducts) of the pulmonary acini. In contrast, there is a long delay in the differentiation of respiratory bronchioles. The former are the first to sustain respiration.
Specific response of ovarian and uterine veins of mice to sex hormones
Authors: Forbes Thomas R. , Kapadia Shanta E. 
Published: February 2005

AbstractPellets of glass (control), progesterone (P), testosterone (T), and estradiol‐17β (E) were placed on the mesentery or subcutaneously in the flank in ovariectomized (O) and ovariectomized‐hysterectomized (OH) mice, insuring that all or most of the hormone would pass through the superior mesenteric or circumflex iliac veins. After 21 days the diameters of these and of the ovarian, uterine, and femoral veins and inferior vena cava were measured at autopsy. T and E caused significant enlargement of the uteri; E was also responsible for bladder distention. The ovarian and uterine veins enlarged significantly in mice treated with T and E as compared to the controls. All other veins failed to respond to P, T, and E. The evidence demonstrates a specific response of ovarian and uterine veins in O and OH mice to T and E.
Sertoli‐Sertoli junctions and Sertoli‐spermatid junctions after efferent ductule ligation and lanthanum treatment
Authors: Ross Michael H. 
Published: February 2005

AbstractSeminiferous tubules, partially dilated by ligation of the efferent ductules, were examined after treatment with lanthanum. Lanthanum penetrated the intercellular spaces of the seminiferous epithelium, but only to the level of the Sertoli‐Sertoli junctions. Further penetration from the interstitial surface of the tubule was restricted by membrane fusions (tight junctions) at the junctional complex. Lanthanum also penetrated the epithelium from the luminal surface permeating the adluminal intercellular spaces, including the site of the Sertoli‐spermatid junction. The lanthanum occupying the Sertoli‐spermatid junctional site appeared as a slightly narrower electron‐opaque zone than that found in the non‐specialized intercellular areas. The findings clearly reveal that only the Sertoli‐Sertoli junctional site forms a restrictive barrier. In contrast to the specializations of plasma membrane which form the tight junction, the associated filaments and cisterna of endoplasmic reticulum may be components more directly related to maintaining and regulating cell adhesion.
Nigro‐amygdaloid fiber connections in the cat
Authors: Kaelber William W. , Afifi Adel K. 
Published: February 2005

AbstractRelatively discrete unilateral lesions were made in the lateral portion of the substantia nigra of eight cats and in the medial substantia nigra of two. After a 10‐day survival period the animals were killed, brains were stored in buffered 10% formalin, and frozen sections were stained for degenerating axons and terminals, or by Weil and cresyl violet methods. Electrodes passed through the medial suprasylvian gyrus, pulvinar and/or posterolateral thalamic nucleus and the medial geniculate body. The stria terminalis and hippocampus were undamaged. Degeneration from the lesion followed two paths. One projected through the reticular nucleus into the internal capsule and then ventrolaterally below the putamen to enter the lateral and central amygdaloid nuclei, with degenerated terminals. The second path ran dorsolaterally in the internal capsule to enter the external capsule where some of the fibers spread into the lateral amygdaloid nucleus. It appears that some of the terminals in the lateral amygdaloid nucleus are from the external capsule. Perhaps these connections link the extrapyramidal system to the amygdaloid body.
The neurohypophyseal capillary bed. I. Anatomy and arterial supply
Authors: Page Robert B. , Bergland Richard M. 
Published: February 2005

AbstractVascular casts of the pituitary‐median eminence complex of mice, rats, dogs, sheep and monkeys were examined with the scanning electron microscope. Microfil‐injected specimens of the rabbit and monkey pituitary‐median eminence complex were examined by light microscopy after intracranial internal carotid artery occlusion. In each species a common neuropophyseal capillary network was found uniting infundibulum (median eminence), infundibular stem and infundibular process. This capillary bed is supplied from above by superior hypophyseal arteries and from below by inferior hypophyseal arteries. An artery to the infundibular stem was found in some species.With occlusion of the intracranial internal carotid arteries, flow through superior hypophyseal arteries did not occur. Yet the entire neurohypophyseal capillary bed filled upon injection with Microfil.These observations suggest the concept of a restricted arterial supply to the median eminence with drainage to the underlying adenohypophysis on one hand and to the infundibular process with drainage to the systemic circulation on the other must be modified and that blood flow within the neurohypophyseal capillary bed (between infundibular process and median eminence) occurs.
Ultrastructure of traumatic cataractogenesis in the frog: A comparison with mouse and human lens
Authors: Rafferty Nancy S. , Goossens William 
Published: February 2005

AbstractNormal and needle‐punctured lenses of Rana pipiens were examined with the electron microscope in order to characterize the sequence of ultrastructural changes that follow the injury over a 5‐month period. Results were compared with those obtained previously in experimentally injured mouse and accidentally injured human lenses. The normal adult frog lens was found to have a morphology similar to that of mammalian lenses. As in the human, frog lens epithelial cells contained scattered microfilaments and were connected by desmosomes and gap junctions. They differed from mouse cells, which had been shown to lack desmosomes and to have microfilaments organized into dense bundles. These differences are postulated to be related to the degree of accommodative deformation of the lens displayed by these species.After injury, cellular debris and fibrin, accumulated in the wound, were phagocytized by extrinsic cells derived from the blood and ocular tissues. Leucocytes, pigmented cells and fibroblasts remained in the wound for eight weeks, along with epithelial cells which proliferated and migrated from the wound margins. Epithelial cells showed an increase in those organelles associated with protein synthesis and transport, and in microfilaments. In cataractous lenses, epithelial cells showed changes in matrix, and lens fibers became organized into smaller, denser compressed units. At five months, considerable healing had taken place, but localized opacities persisted in many frog lenses.