bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immunohiostochemical localization of two types of fatty acid‐binding proteins in rat ovaries during postnatal development and in immature rat ovaries treated with gonadotropins
Authors: Iseki Shoichi , Amano Osamu , Fujii Hiroshi , Kanda Tatsuo , Ono Teruo 
Published: February 2005

AbstractBackground: The ovary of adult rats expresses two types of cytoplasmic fatty acid binding proteins (FABP), i.e., Heart FABP (H‐FABP) and intestinal 15 kDa proteins (I‐15p). We studied immunohistochemically the cellular localizations of these FABPs in the ovaries of rts at various postnatal ages and in the ovaries of immature (3‐week‐old)rats treated with pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (HCG).Methods: The cryosections of ovaries were incubated with polyclonal antibodies aganist H‐FABP and I‐15P, and the immunoreactions were visualized at both light and electron microscpic levels.Results: The immunorectivity for H‐FABP occurred temporarilly in tthe follicular epithelian (granulosa) cells from 3 days to 2 weeks post partum, and then was localized exclusively to the theca/interstitial gland cells from 2 weeks to adulthood. In contrast, the immunoreactivity for I‐15P appeared temporarily in a small subsct of theca/intersitial gland cells from 2 to 3 weeks, disappeared at 4 weeks, and was localized exclusively to the corpus luteum cells after the onset of ovulation in the animal around 5 weeks. In the immature rat ovaries induced to ovulate by treatment with gonadotropins, I‐15P‐immunocreative cells were first recognized in the luteinized granulosa layer of large preovulatory follicles, and increased in number progressively in the developing corpora lutea after the ovulation.Conclusions: Two type of FABPs are expressed in ditinct steroid‐producing cell types of rat ovary, and their expressions seem to be regulated in results suggest that FABPs play specifie roles in the ovarian hormone synthesis. © 1995 Wiley‐Liss, Inc.
Immunohistochemical studies on the development of the hypothalamo‐hyophysial system in Xenopus laevis
Authors: Ogawa Kazushige , Suziku Eiko , Taniguchi Kazuyuki 
Published: February 2005

AbstractBackground: Few attempts have bee made to clarify the relational development of the hypothalamo‐adenohypophysial and neurohypophysial systems in species higher than amphibians.Methods: The appearance and Topographical distribution of endocrine and neuroendocrine cells and fibers in these systems were immunohistochemically examined in the larvae of Xenopus laevis: from immediately before hatching (stage 32, Nieuwkoop and Faber's classification) to the end of metamorphosis (stage 66).Results:(1) Each endocrine cell differentiated until the middle premetamorphic period. MSH cells intially appeared in the posterior half of the pituitary anlage at stage 35/36, followed by the fidderentiation of GH cells at stage 39 in the middle part, PRL cells at stage 46 in the anterior half of the pituitary anlage, and LH cells at stage 50 in the posterior two thirds of the pares distalis. With the progression of development, the cells which differentiated at early stages shifted from their intial positions; MSH cells, to the pars intermedia; and GH cells, to the posterior half of the pars distails. 2) oxytocin and vasopression fibers were observed at stage 47/48 in the median eminence, and converged to the pars nervosa at later stages. 3) Neruoenmorphic to prometamorphic peripd: SOM fibes, at stage 45: CRH, 47/48; GRH, 48; dopamine, 58; and LHRH, 60. The cells containing these hormones were observed in the (presumptive) preoptic and/or infundibular nucleei.Conclusion: These results suggest the floowing three chronological steps in the development of hypothalamo‐hypophysial systems and their target organs: independent development of target organs at early developmental stages; appearance of hypophysial hormones to control the development of target organs at middle developmental stages; appearances of hypothalamoic hormones to control the function of maturation of the hypophysis at late developmental stages. © 1995 Wiley‐Liss, Inc.
Bilateral asymmetry in bone weight at various skeletal sites of the rat
Authors: Fox Kathleen M. , Kimura Sumiko , Plato Chris C. , Kitagawa Tadashi 
Published: February 2005

AbstractBackground: Morphological and funtional asymmery in the limbs has generally been regarded as a human characteristic that is of genetic or of the geneic and environmental origin. The aim of this study was to determine the presence of lateral dominance in bone weight of the forelimb of the rat.Methods: Wistar rats (77) were used, 45 Controls and 32 experimental animals, implanted with a steel weight subcutaneously under the light forelimb. Bones exmined for bilateral asymmetry in bone weight were the mandibula, the bones of fore‐ and hindlimbs, calcaneus, and talus of the tarsus. The Weight of eact dr done was measured to the nearest milligram.Results: Significant bilateral asymmetry in the forelimb was evident in male and female rats, with the left sidehaving more bone mass than the right. Bilaterial difference were more pronounced in the females than the male rats. Greater asymmetr was evident in the experimental group compared to the control rats.Conclusions: These findings demonstrate that asymmetry is present not only in humans, but also in lower animals such as rats. Greater asymmery in the experiemntal rat group is indicative of the influence of environmental factors or physical stress on asymmetry. We conclude that genetics might control the development of asymmetr, but physical stress may alter the functional expression of the asymmetry. © 1995 Wiley‐Liss, Inc.
Identification of vascular sphincters at the junction between alveolar capillaries and pulmonary venules of the mouse lung
Authors: Peáto Mário N. D. , Águas Artur P. , De SÁ Carlos M. , Grande Nuno Rodrigues 
Published: February 2005

AbstractBackground: A peculiar feature of lung circulation in the lung is the pronounced variations in blood volume observed in alveolar capillaries that occur because of the changes in the conformation of the alveolar wall that are associated with the respiratory movements. This phenomenon has led to the postulate that mechanisms of postcapillary control of blood flow are to be present in the lung vessels. In the present study we searched for microanatomical evidence of vascular sphincters in the deep lung tissue of mice, namely in alveolar capillaries and pulmonary veins.Methods: We have used scanning electron microscopy (SEM) to examine two types of samples of normal lung tissue of CD‐1 mice: 1) vascular corrosion casts made by vascular perfusion with Mercox® resin, and 2) routinely made gold/platinum‐coated replicas of sectioned lung tissue.Results: Careful scrutiny of the vessels of the deep lung tissue led to the identification of sphincters in alveolar capillaries. These sphincters were located at the junction between capillary and pulmonary veins. They corresponded to areas to the vascular wall showing circular swellings where a radial organization was observed, since they were made up of alternating grooves and bulges. Transmission electron microscopy showed that smooth muscle cells participated in the formation of the sphincters.Conclusions: Our data reveal a new location for vascular sphincters in pulmonary vessels and, because these novel sphincters are located at the capillary‐vein junction, they offer a structural setting for the existence of postcapillary control of blood flow in the pulmonary circulation of mice. © 1995 Wiley‐Liss, Inc.
Ultrastructure of developing muscle in the upper limbs of the human embryo and fetus
Authors: Tanaka Osamu , Shinohara Haruo , Oguni Masami , Yoshioka Takafumi 
Published: February 2005

AbstractBackground: The ultrastructure of the myogenesis, which proceeds along with the appearance of muscle‐specific proteins and isozymes, has not been fully described in the upper limb of staged human embryos.Methods: Eight human embryos (Carnegie stage 14–22) and two fetuses (11 and 12 weeks of gestation) were fixed with 5% glutaraldehyde, 4% paraformaldehyde, and 0.2% picric acid in 0.1 M phosphate buffer, pH 7.2. The upper limbs were dissected out and processed for transmission electron microscopy, and sections of the biceps brachii muscle were cut and examined.Results: At stage 14, the myoblasts were loosely scattered in the ventral proximal region of the upper limb bud and had a small amount of cytoplasm with a few intracellular organelles. At stage 16, the myoblasts were spindle shaped and oriented parallel to the axis of the upper limb bud. These cells had irregularly shaped nuclei with prominent nucleoli, rough endoplasmic reticulum (ER), and mitochondria, but no myofilaments were observed. At stages 17–19, rough ER, free ribosomes, and mitochondria increased in number and thick and thin filaments with faint Z‐lines appeared in the peripheral cytoplasm of the myotube. The plasma membranes of some neighboring myotubes were continuous, suggesting that these cells were in the initial stages of the fusion process. At stage 22, the striated pattern of the myofilaments became evident and tubular structures appeared around them and near the plasma membrane. In the fetus at the 11th week, the basal lamina began to surround the myotubes, and T‐tubules with sarcoplasmic reticulum were observed. Dyads and triads were observed in the myotube of the 12th week fetus.Conclusion: These findings suggest that rapid myogenesis occurs during the late embryonic period in human upper limbs and that the ultrastructural characteristics of mature myotubes are established during the early fetal period. © 1995 Wiley‐Liss, Inc.
Basement membrane composition of cartilage canals during development and ossification of the epiphysis
Authors: Ganey Timothy M. , Ogden John A. , Sasse Joachim , Neame Peter J. , Hilbelink Don R. 
Published: February 2005

AbstractBackground: Cartilage canals are perichondral invaginations of blood vessels and connective tissue that are found within the epiphyses of most mammalian long bones. Functionally, they provide a means of transport of nutrients to the hyaline cartilage, a mechanism for removal of metabolic wastes, and a conduit for stem cells that are capable of initiating and sustaining ossification of the chondroepiphysis. Morphological and biomolecular changes of the chondroepiphyses appear to potentiate vascular invasion and enable regional formation of secondary centers of ossification within the chondroepiphyses of developing bones.Methods: As both cell migration and vascular invasion are anchorage dependent processes, antibodies to laminin and Type IV collagen were used to assess compositional changes in the basement membrane of cartilage canals accompanying epiphyseal ossification.Results: Differences in chronological appearance, as well as, in distribution between the two components were noted in the chondroepiphysis. Laminin was distributed throughout the connective tissue of cartilage canal at all stages of developement, and not limited to an association with the vascular lumen. Type IV collagen was not Present during the initial perichondral invagination. Although staining for Type IV collagen was later acquired, its distribution was restricted to a discontinuous rimming of the periphery of the canal, and a diffuse presence within the intra‐canalicular mesenchyme.Conclusions: Concurrent with chondrocyte hypertrophy and mineralization of the hyaline matrix, rapid changes in both the morphology of the vessel and distribution of the antibodies were detected. In addition to the presence of laminin at the interface of the endothelium and the hyaline matrix, a wide distribution within the connective tissue components of the newly ossifying matrix of epiphyseal bone could be detected. Type IV collagen remained closely associated with the lumens of the intra‐canalicular vessels throughout the transition. Following ossification of the secondary center, staining for Type IV collagen could then be detected in the boneforming regions of transforming matrix as well, clearly delineating the individual vessels within the newly formed marrow spaces. This suggests that bone formation is intimately related to vessel staining for collagen type IV, and that acquired vessel competence is a facet of endochondral bone formation that results from provisional matrix changes. Furthermore, the data suggests that during bone formation under tension, basement membrane deposition can be demonstrated without an intermediary hyaline matrix hypertrophic chondrocyte phase. This data was interpreted to suggest that chondrocyte hypertrophy at the growth plate may be a reaction to vascular invasion, that in turn, stimulates adjacent chondrocyte proliferation. © 1995 Wiley‐Liss, Inc.
Culture of marmoset blastocysts on matrigel: A model of differentiation during the implantation period
Authors: Lopata Alex , Kohlman D. J. , Bowes L. G. , Watkins W. B. 
Published: February 2005

AbstractBackground: The objective was to develop an experimental model for studying the differentiation of trophoblast and inner cell mass (ICM) during the early stages of implantation in primates.Methods: Marmoset monkey blastocysts were used in these studies. Ovulation was timed by plasma progesterone assays in ovarian cycles initiated by administering a luteolytic agent to mating marmosets. Embryos were recovered from the uterus usually àt the eight‐cell stage and cultured in minimum essential medium containing fetal calf serum, insulin, and transferrin. The embryos that formed hatched hatched blastocysts by about day 11 after ovulation were transferred for further development in Matrigel‐coated culture chambers. After 2, 4, and 6 days of development, two blastocysts were processed at each interval and serially sectioned for light and electron microscopy.Results: All blastocysts adhered to the Matrigel at their embryonic pole within 24 hours. Adherent polar cytotrophoblast was differentiating to syncytiotrophoblast at all time intervals, but syncytium was not detected in mural trophoblast until day 4 after attachment. By day 2 syncytial microvilli and processes had penetrated the Matrigel surface, whereas by days 4 and 6 cytotrophoblast that was differentiating to syncytiotrophoblast had invaded the matrix. Since all blastocysts maintained their structural integrity progressive differentiation of the ICM, endoderm and presumptive mesoderm was observed. A small amniotic cavity was observed at 2 days and by 6 days a distinct cavity separated polarized epiblast and amnion cells. Visceral and parietal endoderm were present at 2 days, and a completed primary yolk sac was observed by 4 days after attachment. In all blastocysts a basal lamina lined the inner surface of mural and polar trophoblast and the basal surface of the differentiating ICM.Conclusions: The developmental time sequence of the cultured blastocysts closely resembled the time frame reported for marmoset embryos implanting in utero. An effective model for studying trophoblast invasion and differentiation of embryonic germ cell layers has been established. © 1995 Wiley‐Liss, Inc.
Ultrastructure and protein transport of M cells in the rabbit cecal patch
Authors: Gebert Andreas , Bartels Helmut 
Published: February 2005

AbstractBackground: The gut‐associated lymphoid tissue of the rabbit cecum includes a single lymphoid patch located close to the ileocecal orifice. Vimentin immunoreactivity, which can now be regarded as a marker for M cells in rabbits, has identified a subpopulation of epithelial cells as M cells in the domes of this patch. The aim of the present study was to demonstrate that these M cells are capable of antigen transport and to characterize their ultrastructure.Methods: M cells of the rabbit cecal lymphoid patch were studied by scanning, thin section, and freeze‐fracture electron microscopy. The transcytosis across these M cells was investigated using horseradish peroxidase as a soluble tracer protein.Results: The M cells were concentrated at the flanks of the domes and had long, thick, branched microvilli, a well‐developed terminal web, and a deep invagination of their apical membrane. Numerous small vesicles lay beneath the terminal web in close vicinity to the base of the invagination. These vesicles transported the luminally applied horseradish peroxidase through the M cells. In contrast to adjacent enterocytes, the glycocalyx of M cells was thin, stub‐like, and had very few glycocalyceal bodies. Bacteria adhered to the surface of M cells and were also found in the apical invagination.Conclusions: The M cells of the rabbit cecal lymphoid patch differ from those of Peyer's patches of the small intestine in their ultrastructure and route of antigen transport. These differences might be related to the situations resulting from differences in the microbial populations at these locations. © 1995 Wiley‐Liss, Inc.
Developmental expression of connexins in the chick embryo myocardium and other tissues
Authors: Wiens Darrell , Jensen Lisa , Jasper Jill , Becker Jennifer 
Published: February 2005

AbstractBackground: Connexins are cell surface proteins that form specialized regions of cell‐cell communication called gap junctions. These allow impulse conduction in involuntary muscle tissue such as the heart, but also allow the formation of communities of like cells during development of organs.Methods: We used an antipeptide antibody to connexin 43 in immunolocalization studies and an anti‐peptide antibody to an external loop domain common to most connexins in Western blotting of total heart protein to measure the accumulation of connexins in the heart as it develops from 33 hours to 21 days (hatching), and in the adult.Results: Immunolocalization revealed that connexin 43 is widely distributed in the earliest organ rudiments. It is especially prominent in the neural tube and its derivatives, in the lens and nasal placodes, in the foregut and its derivatives, in the somites, in the mesonephric tubules, and in the heart and major arteries. Heart tissue staining grew more intense with development through day 8. However, at day 11 and day 15, and in the adult, heart staining diminished. Endocardium and valve tissue did not stain. Western blotting of heart homogenates with the antibody directed against the external loop domain peptide showed 26, 32, 43, 45, and 56 kilodalton connexins, which changed in relative abundance, displaying unique patterns during development.Conclusions: Our results show patterns of connexin immunolocalization in early germ layers and organ rudiments that are similar to those known in the mouse, but with certain differences. Our results show a distinctive pattern of multiple connexin gene expression in the developing heart from days 2–21. © 1995 Wiley‐Liss, Inc.
Effect of adriamycin on the RPC C2A cloned cell line from rat incisor pulp
Authors: Karim A. C. 
Published: February 2005

AbstractBackground and Methods: RPC C2A cells, cloned from Wistar rat incisor pulp, were grown in culture 2–7 days after exposure to adriamycin at a concentration of 0.1 mg/L for 2 hours. Morphological changes, labelled proline incorporation and alkaline phosphatase activity were studied in response to this treatment.Results: At the light microscopic level, colonies of enlarged cells appeared 2 days after adriamycin treatment. The size of these colonies increased during the course of this study. The control samples showed no apparent changes. At the electron microscopic level, the small cells in the adriamycin‐treated cultures showed fewer vesicles than the controls, but more prominent rough endoplasmic reticulum. However, the enlarged cells contained an abundance of vesicles, and few profiles of rough endoplasmic reticulum. Radiolabelled proline incorporation in the control group was significantly higher than the experimental after 2 days in culture, but showed no significant difference after 7 days. Histological staining for alkaline phosphatase showed that there was a slightly higher intensity in the control samples than in the experimental cultures at this time.Conclusions: This study has shown that the RPC C2A cells will respond to adriamycin treatment in vitro, where the acute effects were quite different from the protracted effects with respect to labelled proline incorporation and alkaline phosphatase activity. © 1995 Wiley‐Liss, Inc.
Hyperthermia induces ultrastructural changes in mouse pial microvessels
Authors: Fahim Mohamed A. , El‐Sabban Farouk 
Published: February 2005

AbstractBackground: Pial microvessels' responses to local hyperthermia revealed the development of in vivo spontaneous thrombosis. The cellular and subcellular changes which contribute to such events remained unexplored. Therefore, the effect of regional hyperthermia (43°C) on mouse pial microvessels was studied at the ultrastructural level.Methods: A simple cranial window assembly, including an artificial cerebrospinal fluid delivery and heating system to ensure a precise brain regional temperature, was used. The animal core body temperature was maintained at 37°C. Topical and transvessel bimodal fixation of microvessels was done with a phosphate buffered mixture of glutaraldehyde and paraformaldehyde, followed by a standard electron microscopy procedure.Results: When the pial microvessels of control (37°C) animals were examined, no evidence of cellular damage was discerned. Endothelial. cells including luminal membrane were unchanged. Degranulated platelets or platelet aggregates were not seen. However, numerous platelets in association with scattered red blood cells and occasional white blood cells could be observed in a close proximity, but not adhered, to the endothelial wall of hyperthermic (43°C) brains. Platelets displayed a variety of forms consistent with the onset of platelet activation. Discoid platelets containing granules and spheroid degranulated platelets and those with large pseudopodia were recognized. The venular endothelial surface revealed conspicuous endothelial change, with the presence of endothelial denudation. The site of platelet aggregation in both venules and arterioles was accompanied by focal endothelial lucency and denudation vacuole formation, luminal membrane rupture, and swelling of the nuclear envelope.Conclusions: These findings demonstrate the extent of damage to the pial microvasculature in response to a local hyperthermic exposure. The results emphasize that changes in the endothelium may represent the earliest signs of oncoming vascular pathology. © 1995 Wiley‐Liss, Inc.