bluuebunny/crossref_metadata_2025_split huggingface dataset:
Epithelial reorganization and irregular growth following carbendazim‐induced injury of the efferent ductules of the rat testis
Authors: Nakai Masaaki , Moore Billy J. , Hess Rex A. 
Published: February 2005

AbstractOcclusions of the rat efferent ductules were induced by an oral gavage of carbendazim and the capacity for regeneration or recanalization of the ductules was histologically evaluated between 2 and 70 days post‐treatment. At 2 days post‐treatment, the efferent ductules were occluded by sloughed materials and showed various degrees of inflammation. Severely damaged epithelium showed few regenerative features at later intervals. On the other hand, epithelia with medium inflammation often exhibited irregular epithelial growth along the luminal contents or the formation of multiple abnormal ductules. These abnormal ductules were formed by migrated and original epithelia at the periphery of the occluded lumen at 16 days post‐treatment, indicating attempted recanalization. At later time periods, 32 and 70 days post‐treatment, the occluded original lumen was filled in by fibrotic connective tissue and surrounded by a series of abnormal ductules. These abnormal ductules were characterized by cuboidal epithelia, a small luminal diameter, fewer cilitated cells than normal, less developed organelles in the epithelial cells, and basal laminae of irregular thickness. However, there was no evidence that occluded ductules formed patent re‐connections via abnormal ductules. The results suggest that occluded efferent ductules have the ability to initiate epithelial regrowth and to form new ductules, but the newly formed ductules are abnormal and are not adequate to recover from azoospermia at least at 70 days post‐treatment. © 1993 Wiley‐Liss, Inc.
Cellular proliferation in the anterior pituitary gland of normal adult rats: Influences of sex, estrous cycle, and circadian change
Authors: Oishi Yuji , Okuda Minoru , Takahashi Hideki , Fujii Toshiyuki , Morii Sotokichi 
Published: February 2005

AbstractProliferative activity of the anterior pituitary gland in 10 week‐old male and female rats under normal conditions was investigated by counting mitotic figures and using single and double immunostaining of 5‐bromo‐2′‐deoxyuridine (BrdU), proliferating cell nuclear antigen (PCNA), and six pituitary hormones. To determine which proliferative changes depend on the estrous cycle and circadian changes, respectively, six groups of female and two groups of male rats were studied at various times of day. Additionally, BrdU‐incorporated cells were further classified by the six types of hormones they contained, or as immunonegative cells. Cell proliferative activity in the females fluctuated drastically with the highest activity in estrus and the lowest in diestrus. In the males, proliferative activity was at a relatively low level, and was similar to that in females in proestrus or early estrus, with the greater activity at night. Identified by their pituitary hormones, the distribution of the proliferating cells was almost the same in each sex, with prolactin (PRL) cells accounting for the highest proportion, followed by growth hormone (GH) cells, and adrenocorticotropic hormone (ACTH), luteinizing hormone (LH), follicle stimulating hormone (FSH), and thyroid stimulating hormone (TSH) cells. These percentages agreed well with previously reported levels of cell types among all pituitary cells of the rat. It is therefore suggested that the life span and cycle of rat pituitary cells does not differ among cell types. In another test, male and female rats were given BrdU continuously via an osmotic pump for 8 days to compare cell proliferative activity between sexes, exclusive of the influence of estrous cycle and circadian changes. In this way, we were able to demonstrate that the cumulative incorporation of BrdU in females was consistently twice as high as in males over a constant period of time, and to conclude that cell renewal occurs at a doubled rate in the pituitary of female rat. © Wiley‐Lis, Inc.
Development of the liver in the chicken embryo. II. Erythropoietic and granulopoietic cells
Authors: Wong Gene K. , Cavey Michael J. 
Published: February 2005

AbstractHepatic hemopoiesis is apparent in the chicken embryo on day 7 of incubation (Hamburger and Hamilton Stage 30), and a peak in hemopoietic activity occurs on day 14 (Stage 40). During this period, the differentiation of hemopoietic cells was examined by light microscopy and by transmission and scanning electron microscopy. Glycol methacrylate sections were used in lieu of smears to study hemopoietic cells, thus minimizing the problems of cell shrinkage and rupture. The sections were superior to smears for close examination of nuclear and cytoplasmic morphologies and for precise localization of hemopoietic cells to intravascular and extravascular sites. The avian liver is involved directly with erythropoiesis and granulopoiesis only. Erythropoietic cells, occurring in intravascular and extravascular locations, appear throughout the time frame examined. Blood islands with granulopoietic cells were not observed until days 8–9 (Stage 35). Granulopoiesis in the liver produces only eosinophilic leukocytes. Individual granulopoietic cells appear first in the connective tissue sheaths of hepatic vessels, and these cells subsequently congregate into blood islands. Endothelial cells of the sinusoidal linings, through asymmetric divisions, frequently release daughter cells into the circulation, and Kupffer cells are actively engaged in phagocytosis of erythrocytes. From a comparative standpoint the elements deemed critical to hemopoiesis in the mammalian liver–prehepatocyte population, hepatic vasculature, and compartments for stem cell differentiation–may not hold the same importance in the bird, owing to an inordinate reliance on intravascular hemopoiesis in this vertebrate class. © 1993 Wiley‐Liss, Inc.
Possible nonlinear effects of exercise on bone in male subjects over age 60 years
Authors: Vico Laurence , Bourrin Sandrine , Chatard Jean‐Claude , Palle Sabine , Very Jean‐Michel , Lacour Jean‐Rene , Alexandre Christian 
Published: February 2005

AbstractWe investigated the relationships among bone mass, bone cell activities, and exercise level in 20 healthy 61–77 year old male volunteers divided into three groups according to the time they physically trained per week: nine subjects training less than 3 hr/week, five subjects between 3 and 6 hr/week and six subjects more than 6 hr/week. Physical performance was evaluated by Vo2 max (ml min−1 kg−1). After tetracyline double labeling, iliac crest biopsy was obtained from each subject. The longer the physical activity, the higher the Vo2 max. Subjects exercising between 3 and 6 hr/week revealed higher adjusted appositional and bone formation rates than all the others; mass and structural parameters also showed higher (nonsignificant) values. For the whole population V̇o2 max appeared negatively related to cortical thickness, cancellous bone volume, and trabecular thickness. These alterations were accompanied by increased cancellous bone turnover; this was evidenced by an increase in activation frequency and in resorption and formation rates as V̇o2 max increased. The bone remodeling periods tended to decrease also. Whatever the bone turnover rate, subjects were in steady state as far as their bone balance was concerned. Relationships between V̇o2 max and mineral apposition rate on the one hand and V̇o2 max and resorption surface on the other hand were best fitted by a quadratic model, suggesting a possible nonlinear effect of physical training on bone mass. We hypothesize that there is a threshold (6 hr/week) determining different effects. Adjustment of bone mass and trabecular arrangement were completed at time of biopsy and reflected probably past and transient bone imbalance. Other studies are needed to corroborate this assumption. © 1993 Wiley‐Liss, Inc.
Effects of androgen deprivation and estrogen treatment on the structure and protein expression of the rat coagulating gland
Authors: Holterhus P. M. , Zhao G. Q. , Aumüller G. 
Published: February 2005

AbstractThe effects of androgen deprivation and estrogen stimulation on rat coagulating gland were determined by immunohistochemistry and morphometric quantification of different tissue compartments. In castrated or estrogen‐treated or estrogen‐treated castrated animals, the reduction of the glandular lumen is the most obvious morphological alteration, which is accompanied by an increase in stromal tissue, especially within the lamina propria. Regressive changes occur most rapidly in castrated animals (already by the end of the first week), slower in estrogen‐treated castrated animals, and still slower in estrogen‐treated normal animals. In castrated animals, epithelium shows a reduction of rough endoplasmic reticulum, loss of secretory blebs, and a decrease of cell size and immunoreactivity for secretory transglutaminase. The reduction of glandular lumen results from an impressive increase in connective tissue of the lamina propria. Smooth muscle cells become atrophic in castrated animals, less so in estrogen‐treated animals and in castrated estrogen‐treated animals. A relative increase in thickness of the smooth muscle cell layer occurs in all experimental groups and is most obvious in estrogen‐treated normal animals. The proportion of myofilament and intermediate filament proteins (smooth muscle‐specific actin and desmin immunoreactivities) remains nearly unaltered in these cells after hormonal challenge. A redistribution of intermediate filaments occurs forming thicker bundles within the cells. No indication for increased mitotic activity of estrogenized smooth muscle cells has been found. After castration, and after estrogen treatment, the fibroblasts and the smooth muscle cells, respectively, appear responsible for the architectural changes within the coagulating gland. Reactions of the stroma are differentially regulated after estrogen treatment and androgen deprivation. No indication for increased biosynthetic activities of smooth muscle cells has been observed in any of the experimental conditions. © 1993 Wiley‐Liss, Inc.
Dendritic cell/lymphocyte clustering: Morphologic analysis by transmission electron microscopy and distribution of gold‐labeled MHC class II antigens by high‐resolution scanning electron microscopy
Authors: Setum Cindy M. , Serie Janet R. , Hegre Orion D. 
Published: February 2005

AbstractDendritic cells (DCs) are potent antigen‐presenting cells for a variety of immune responses; however, their mechanism of action has not been established. It is known that DCs can cluster with one another and with other cell types during in vitro immune responses, and clustering may be essential for the activation of resting lymphocytes. In this study, ultrastructural examination of clusters that form during extended culture of enriched rat splenic DCs (approximately 70% DCs) is reported. DCs were readily distinguished from other cell types, which inclued lymphocytes and macrophages. DCs displayed characteristic veils and/or dendritic processes that intertwined with processes of other cells within the cluster, or extended from the cluster periphery. Occasional DCs contained large vacuoles lined with small vesicles. A paramount feature of DCs is their constitutive expression of high levels of surface major histocompatibility complex class II antigens. The surface distribution of class II antigens on clustering DCs was examined using 10 nm immunogold labeling techniques and high‐resolution scanning electon microscopy. DCs were readily distinguished by morphologic criteria, and examination of various surface membrane regions revealed a differential distribution of class II antigens. Gold label was frequently distributed in linear arrays and clusters, suggesting a cytoskeletal role in the recycling/redistribution of Class II antigens. These morphologic findings further an understanding of basic DC biology and their mechanism of action as antigen presenting cells. © 1993 Wiley‐Liss, Inc.
Morphometric changes in growth of the rat pelvis after papain administration
Authors: Dixon Andrew D. , Gakunga Peter T. 
Published: February 2005

AbstractThe proteolytic enzyme, papain, was given systematically to evaluate the short‐ and long‐term effects of inhibition of endochondral bone formation on pelvic growth, with emphasis on the innominate bone. Ninety‐eight Lewis‐strain male rats, used concurrently for craniofacial growth studies, were divided into two groups. Thirty rats from Group I (n = 48) received 2% crude papain i.p. daily from 25–40 days‐of‐age and were euthanized at 40, 54, and 70 days‐of‐age. Thirty‐five rats from Group II (n = 50) were given papain at the same dose from 25–70 days‐of‐age and were euthanized at 26, 40, 54, 70, and 120 days. The remaining animals in both groups were the controls. Standardized dorsoventral pelvic radiographs were taken of all 98 animals. Ten linear dimensions were measured on each and the data evaluated statistically. A reduction both in size and rate of growth of the bony pelvis was found. All the anteroposterior and most of the transverse pelvic dimensions were significantly shorter, to a greater extent in the prolonged papain group. Bi‐ischial width was increased, perhaps to compensate for pelvic shortening and to accommodate the pelvic contents. The findings may contribute to our better understanding of abnormal endochondral bone growth in the pelvis. © 1993 Wiley‐Liss, Inc.
Promotion of muscle regeneration in the toad (Bufo viridis) gastrocnemius muscle by low‐energy laser irradiation
Authors: Bibikova Anna , Oron Uri 
Published: February 2005

AbstractThe effect of low‐energy laser (He‐Ne) irradiation on the process of skeletal muscle regeneration after cold injury to the gastrocnemius muscle of the toad (Bufo viridis) was studied using quantitative histological and morphometric methods. The injured zones in the experimental toads were subjected to five direct He‐Ne laser (632.8 nm wavelength) irradiations (6.0 mW for 2.3 min) every alternate day starting on the fourth day postinjury. Muscles that were injured as above, and subjected to redlight irradiation, served as a control group. Morphometric analysis was performed on histological sections of injured areas at 9, 14, and 30 days postinjury. At 9 days postinjury, mononucleated cells populated 69.3% ± 16.8% of the total area of injury. Thereafter, their volume fraction (percent of total injured zone) decreased gradually but more rapidly in the laserirradiated muscle than in the control. The volume fraction of the myotubes in the laser‐irradiated muscles at 9 days of muscle regeneration was significantly higher (7.0% ± 2.2%) than in the control muscle (1.2% ± 0.4%). Young myofibers in the laser‐irradiated muscles populated 15.5% ± 7.9% and 65.0% ± 9.5% of the injured area at 9 and 14 days of muscle regeneration, respectively, while in control muscles these structures were not evident at 9 days and made up only 5.3% ± 2.9% of the traumatized area at 14 days postinjury. The volume fraction of the young myofibers further increased by 30 days of muscle regeneration making up 75.7% ± 13.2% of the traumatized area, while in the laser‐irradiated muscles most of the injured zone was filled with mature muscle fibers. It is concluded that He‐Ne laser irradiation during the regeneration process markedly promotes muscle maturation in the injured zone following cold injury to the toad gastrocnemius muscle. © 1993 Wiley‐Liss, Inc.
The physiological cross‐sectional area of motor units in the cat tibialis anterior
Authors: Eldred E. , Garfinkel A. , Hsu E. S. , Ounjian M. , Roy R. R. , Edgerton V. R. 
Published: February 2005

AbstractThe physiological cross‐sectional area (CSA) of a motor unit (MU), taken as the sum of fiber areas measured on a single section through the approximate midlength of the MU, has been compared with the physiological CSA more strictly defined as the sum of the maximal areas to be found anywhere along the length of each of the MU fibers. The CSA at intervals along the fiber length was measured in fibers selected from four glycogen‐depleted, isolated MUs in the cat tibialis anterior (TA), and profiles of the summed areas made. In one MU, measurements were also taken on all the MU's fibers at less frequent intervals. The profiles demonstrate that the summed CSA based on each fiber's maximum CSA may exceed that derived from observation on any single section by as much as 20%. As a consequence, values that have been reported for specific tension (force per unit area) of MUs in the TA and probably other muscles may have been overestimated, especially for those MUs of fast type. Estimates were also made of the share of the MU's total force transmitted directly to the tendons of origin and insertion via endings of the blunt musculotendinous type as distinct from tapering intrafascicular endings acting through in‐series connective tissue and non‐MU fibers. In two MUs of slow type in which most fibers ran from tendon to tendon, “partial tapering” extending over 1 cm of the fiber length accounted for a third of the total physiological CSA, and indicated yet another mode for relay of the MU's force to the tendon. © 1993 Wiley‐Liss, Inc.
Development of the coronary arteries and cardiac veins in the dogfish (Scyliorhinus canicula)
Authors: De Andrés A. V. , Muñoz‐Chápuli R. , Sans‐Coma V. 
Published: February 2005

AbstractThe development of the coronary system in the Dogfish was studied using light microscopy. The sample examined consisted of 44 embryos and four newborns. The chronology of events occurring during the process was referred to the total length (TL) of the specimens. The nourishment of the developing myocardium first takes place by means of intertrabecular sinusoids. This system is later switched to a circulation through coronary vessels. The cardiac veins develop earlier than the coronary arteries. The earliest evidence of development of heart vessels in the present sample was the appearance of a diverticulum from the sinus venosus in three embryos of 31 mm TL. This diverticulum outlined the future coronary sinus. Both the atrioventricular and conoventricular venous rings were completely developed in an embryo of 36 mm TL. Coronary artery vessels appeared for the first time in embryos of 40 mm TL. In these specimens, two arteries arose from the midventral hypobranchial artery and divide to give rise to the four coronary artery conal trunks. In a 51‐mm TL embryo it was already possible to follow the course of the coronary arteries, from the hypobranchial artery to the conoventricular groove. All main coronary vessels were fully developed in embryos of more than 58 mm TL. However, the arteries supplying the atrium were firstly recorded in a newborn of 77 mm TL. Birth usually occurs when the shark reaches about 72–76 mm TL. © 1993 Wiley‐Liss, Inc.
Blood‐urine barrier formation in mouse urinary bladder development
Authors: Jezernik Kristijan , Pipan Nada 
Published: February 2005

AbstractFormation of the blood‐urine permeability barrier in differentiating mouse transitional urothelium was studied. It was established that the development of superficial cell barrier is a two‐phase process: beginning with formation of the tight junctions, followed by formation of fusiform vesicles and asymmetric apical plasma membranes. Fusiform vesicles differentiate during days 15 and 17 of gestation and fuse with the apical plasmalemma. Thus a thick membrane is formed before the excretion of hypertonic urine into the embryonic bladder. Through some degenerative superficial cells slough between fetal day 17 and the day of birth, the bladder epithelium in mice does not lack an effective permeability barrier. © 1993 Wiley‐Liss, Inc.
Immunohistochemistry of the human ductus epididymis
Authors: Palacios José , Regadera Javier , Paniagua Ricardo , Gamallo Carlos , Nistal Manuel 
Published: February 2005

AbstractOur objective was to characterize epithelial cells, lamina propria, and sites of estrogen coupling in the caput, corpus, and cauda regions of the human epididymis using antibodies to cytokeratin types; epithelial membrane antigen; laminin; type IV collagen; vimentin; desmin‐, and estradiol‐receptor‐related protein; and immuno‐histochemical techniques. Principal cells immunostain by both AE1/AE3 antibodies (keratins 1–8, 10, 13–15, and 19) and anti‐pan‐keratin antibodies (keratin 5, 6, and 8). Immunoreactions to both anti‐keratin antibodies increase from the caput to the cauda epididymis. The principal cells only immunostained by antikeratin 19 antibodies in the cauda and showed no reaction to keratins 10 and 11. Basal cells and apical cells immunoreact to anti‐AE1/AE3, antipan‐keratin, and antikeratin 19 antibodies, but not to antikeratin 10 and 11 antibodies, in all three epididymal regions. The principal cells immunoreact with epithelial membrane antigen antibodies in the stereocilia and subjacent cytoplasm. This immunostaining decreased from the caput to the cauda. Antivimentin antibodies stained the apical cytoplasm of principal cells and limited areas of both principal cells and basal cells. This immunoreaction decreased from the caput to cauda. Apical cells immunostained in the three regions. Immunoreaction to ER‐D5 was moderate in the principal cells, basal cells, apical cells, and muscular coat cells in the cauda. The apical cells immunostained in the three regions. Antilaminin antibodies stained the epithelial basement membrane in the three regions. Type IV collagen was detected in the basement membrane as well as around the muscular coat cells in the three regions. Immunoreaction to desmin was intense in the muscular coat cells in the three regions. Thickness of the immunostained area for both type IV collagen and desmin increases from the caput to the cauda. The differences in immunostain pattern along the epididymis length seem to be related to regional differences in function. © 1993 Wiley‐Liss, Inc.
Pulmonary neuroendocrine cells in species at high altitude
Authors: Gosney John Roy 
Published: February 2005

AbstractEver since pulmonary neuroendocrine cells were first described, a chemoreceptor function has been attributed to them. This hypothesis proposes that the innervated clusters of these cells, which are known to degranulate when the oxygen tension around them is reduced, respond to hypoxia to initiate activity in a reflex arc and ultimately adjust some aspect of pulmonary function. If this were true, one might expect to see changes in the pulmonary neuroendocrine system in species exposed to the unremitting hypoxia at natural high altitude. Whilst evidence from some studies suggests that such changes do occur, others have been unable to demonstrate any effect. To some extent this may be attributable to species variability, but might also reflect whether the organism is genetically adapted or merely acclimatized to life in an oxygen‐poor environment. © 1993 Wiley‐Liss, Inc.