bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pars distalis vasculature: Discovery shuttle STS‐29 rats compared to ground‐based antiorthostatic rats
Authors: Pattison Amy , Pattison Tim , Schechter Joel 
Published: February 2005

AbstractThe anterior pituitary glands of male, adult Long Evans rats carried 5 days in the Space Shuttle Discovery (STS‐29) have been compared with two groups of ground‐based controls. All of the animals were part of a study (SE82‐08) into the effects of gravity versus a microgravity environment on fracture healing. All had sustained a right, mid‐shaft fibular osteotomy. The duration of the study was 10 days, and animals in all groups were weight bearing for the 5 days prior to shuttle lift off. The three experimental groups consisted of four rats each: flight (F) and two ground‐based control groups, weight bearing (WB) and suspended (S). The suspension group was in a Holton/Sweeney head‐down suspension apparatus (antiorthostatic) for the final 5 days of the study. The anterior pituitary glands of F and WB rats were essentially identical. The vasculature and parenchymal cells appeared unaffected in both instances. However, the anterior pituitary glands of S rats were dramatically altered. The vasculature was widely expanded with proteinaceous deposition covering the lumenal endothelial surfaces, and entrapping numerous platelets and aggregates of red blood cells. Parenchymal cells were highly vacuolated, occasionally with membranous vacuoles, but most often revealing large, clear cytoplasmic zones unlined by any membranes. Whereas profiles of exocytosis were numerous in F rats, and present in WB rats, they were essentialy absent in S rats. These results indicate that weightlessness over a 5‐day flight period does not influence the structural integrity of the anterior pituitary gland and may in fact promote secretory granule release. However, the head‐down tilt model, frequently used to study fracture repair under conditions that mimic weightlessness, has a profound impact on the vasculature of the anterior pituitary gland which then affects the structural and functional characteristics of the parenchymal cells.
Formation of secretory granules in the Golgi apparatus of prolactin cells in the rat pituitary gland: A stereoscopic study
Authors: Rambourg A. , Clermont Y. , Chrétien M. , Olivier L. 
Published: February 2005

AbstractThe mode of secretory granule formation in prolactin cells was analyzed in thin or thick sections of pituitary glands from non‐lactating or lactating female as well as from male rats. In all these animals, the Golgi apparatus of prolacting cells consists of a continuous twisted ribbon‐like structure that branches and anastomoses to form a hollow sphere located in the juxtanuclear area. The early signs of secretory granule formation are observed along the trans‐aspect of the Golgi ribbon where progranules appear as focal distensions simultaneously occurring anywhere in the last trans thiamine pyrophosphatase (TPPase)‐containing Golgi element. In the transmost Golgi saccule, such dilatations usually contain several nodular masses of electron opaque material which are separated from each other and from the saccular membrane by a less intensely stained material. While this transmost saccule becomes more fenestrated, its focal polynodular distensions seemingly yield polynodular tubular progranules which are initially closely apposed and usually parallel to the trans face of the Golgi ribbon. Subsequently, these progranules, which frequently show small membranous tubules or tubular networks attached to them, are seen some distance from the Golgi stacks and progresively transform into the more compact polymorphous granules characteristic of prolactin cells. These observations suggest that the polynodular tubular progranules arise by fragmentation of portions of the trans‐Golgi elements rather than by fusion of small uninodular granules budding from the edges of a trans‐Golgi saccule. Once the progranules have been liberated, the rest of the transmost Golgi element appears to break down into small residual networks, tubules, and vesicles. Thus, in prolactin cells as in other glandular cells, the whole transmost Golgi element would fragment during formation of prosecretory granules.
Glomerular number and size in relation to age, kidney weight, and body surface in normal man
Authors: Nyengaard J. R. , Bendtsen T. F. 
Published: February 2005

AbstractThe number and size of glomeruli in normal, mature human kidneys were estimated by a direct and unbiased stereological method, the fractionator. The number was 617,000 on average, and the mean size 6.0 M μm3. Both glomerular number and size showed significant negative correlation to age and significant positive correlation to kidney weight. Apparently, humans loose glomeruli with age.Body surface area correlated positively to kidney weight and total glomerular volume but not to number of glomeruli. Body surface area correlates significantly with metabolic rate (Robertson and Reid, Lancet, 1: 940–943, 1952). Thus, intraspecies adaptation of kidney filtration capacity to the metabolic demand is performed by changing the size of glomeruli, i. e., the number of glomeruli in individuals of a given species is independent of the metabolic rate.
Identifying and counting epithelial cell types in the “corpus” of the mouse stomach
Authors: Karam Sherif M. , Leblond Charles Philippe 
Published: February 2005

AbstractThe epithelial cells lining the oxyntic mucosa in the stomach “corpus” were identified, localized, and counted in 2‐month‐old male C57BL‐6 mice, using glutaraldehyde‐formaldehyde fixation and osmium tetroxide postfixation for studies in the light microscope (LM) while adding tannic acid to the fixative and postfixing in ferrocyanide‐osmium for studies in the electron microscope (EM).The cells form a single epithelium, which invaginates into blind tubular units. Each unit is divided into four successive regions: pit, isthmus, neck, and base. On the average, a unit contains 194.2 cells. The cells have been classified into three groups totaling 11 types, listed with their mean number per unit. The first group is composed of three well‐characterized cell types, each restricted to a region: (1) 37.0 surface mucous cells, hereafter called pit cells, in the “pit” region, (2) 12.6 mucous neck cells, simply called neck cells, in the “neck” region, and (3) 67.4 zymogenic cells in the “base” region.The second group is also composed of three well‐characterized cell types, distributed over the four regions: (1) 26.0 parietal cells, (2) 13.2 entero‐endocrine cells, and (3) 0.6 caveolated cell.The third group consists of five cell types, which have been little or not characterized in the past. Four are located in the “isthmus” region and show EM features indicative of immaturity, that is, a nucleus with mainly diffuse chromatin and large reticulated nucleoli, and a scanty cytoplasm rich in free ribosomes: (1) 17.2 cells are the least differentiated in the epithelium; they are devoid of secretory granules and accordingly named granule‐free cells, (2) 10.0 cells contain a few dense secretory granules smaller than, but otherwise similar to, those in pit cells; they are referred to as pre‐pit cells, (3) 1.8 cells possess a few marbled secretory granules that often exhibit a pale core and are smaller than, but otherwise similar to, those in neck cells; they are called pre‐neck cells, (4) 0.6 cells display long microvilli and/or small canaliculi similar to those in parietal cells; they are named pre‐parietal cells, and (5) 5.6 cells restricted to the base region are characterized by secretory granules with features intermediate between those of neck and zymogenic cells; they are named pre‐zymogenic cells.The observations suggest the following hypothesis on cell filiation. The granulefree cells would function as stem cells and give rise to pre‐pit, pre‐neck, and preparietal cells, which would, respectively develop into pit, neck, and parietal cells; neck cells would then transform into pre‐zymogenic cells, which would finally become zymogenic cells. Entero‐endocrine and caveolated cells would come directly from the postulated stem cell.
The morphological basis of folded‐wing posture in the American Kesrel, Falco sparverius
Authors: Meyers Ron A. 
Published: February 2005

AbstractGross dissection and histochemical analysis of the shoulder musculature of the American kestrel, Falco sparverius, revealed that four muscles are specialized for slow contraction and may function in the postural control of the folded wing. Mm. latissimus dorsi pars cranialis, scapulohumeralis cranialis, and brachialis were found to contain > 95% tonic fibers, whereas M. deltoideus minor was found to possess a relatively even mix of fast‐twitch and tonic muscle fibers. M. latissimus dorsi pars cranialis, M. scapulohumeralis cranialis, and M. brachialis crosses the elbow joint on the ventral surface of the forearm. This paper suggests postural muscles have largely been ignored in studies of avian musculature, and the need to consider a variety of possible muscle functions when analyzing locomotor muscle functions.
Macrophage development: II. Early ontogeny of macrophage populations in brain, liver, and lungs of rat embryos as revealed by a lectin marker
Authors: Sorokin Sergei P. , Hoyt Richard F. , Blunt Dana G. , McNelly Nancy A. 
Published: February 2005

AbstractEarliest origins of macrophage populations in the central nervous system, the liver, and the lungs were studied in rat embryos aged between 10.5–11 days and 14 days of gestation, based on light and electron microscopic identification of macrophages using peroxidase‐coupled isolectin B4 of Griffonia simplicifolia (GSA I‐B4), which recognizes alpha‐D‐galactose groups on the cell membrane. During embryonic life macrophages and their precursors are GSA I‐B4‐positive and generally bereft of peroxidase‐positive granules. At 10.5 days the yolk sac and embryonic circulations have just become joined, the brain has five vesicles but nerve cells are little differentiated, the liver exists as a diverticulum of the gut with fingerlike extensions of hepatocytes, and the lungs as a laryngotracheal groove. Macrophages and/or their precursors occurred in small numbers in embryonic mesenchyme and blood vessels but showed no special affinity for either liver or lung rudiments. The developing brain was the first organ to be colonized, beginning on prenatal day 12. The liver followed between days 12 and 13 and was succeeded by the lungs, beginning between days 13 and 14. Dividing macrophages were present in these organs at the outset of colonization and throughout the duration of the embryo series, indicating that from the beginning, replication of resident cells contributes to growth of the local population. Granulocyte precursors were first apparent in the liver around day 13; they are also GSA‐positive but are distinguished from macrophages by their content of peroxidase‐positive granules. Organ cultures of 13‐day liver and lungs, and 14‐day brain tissue, indicate that whereas isolated liver fragments support the formation of both granulocytes and macrophages, only the latter develop in brain or lung cultures. A resident population of macrophages evidently is set up very early in these organs, well before white cells colonize the spleen, bone marrow, and other future blood forming regions. The events outlined are seen as stages in an embryo‐wide process that leads to establishment of macrophage populations in various organs.
Differentiation of bursal secretory‐dendritic cells studied with anti‐vimentin monoclonal antibody
Authors: Olah Imre , Kendall Cyndy , Glick Bruce 
Published: February 2005

AbstractEmbryonic and posthatched differentiation of bursal secretory dendritic cells, which express vimentin intermediate filaments, were studied with anti‐vimentin (clone 3B4) and anti‐cytokeratin (clone Lu5) monoclonal antibodies. Anti‐cytokeratin staining revealed that medullary reticular epithelial cells formed a continuous network at every age, whereas the vimentin positive cells were single and showed dendritic appearance. On the basis of location, number, shape, polarized appearance, and Ia staining, the vimentin‐positive cells and secretory dendritic cells appeared to be the same cell.Secretory dendritic cell precursors entered the bursal epithelium between 11 and 13 days of embryogenesis. The first vimentin positive cell appeared in the bud of 14‐day embryos. Bud formation preceded the appearance of vimentin‐positive cells. These observations suggested that the secretory dendritic cell precursor did not express vimentin when it entered the epithelium. Between 15 days of embryogenesis and 2 weeks of posthatch development, the changes in vimentin staining pattern revealed a cytological differentiation of the vimentin‐positive cell. During rapid bursal growth, the number of secretory dendritic cells (vimentin‐positive cells) increased about 18 times possibly by proliferation of vimentin‐negative precursors in the epithelial arches of the corticomedullary border. © 1992 Wiley‐Liss, Inc.
The neuroepithelial cells of the fish gill filament: Indolamine‐immunocytochemistry and innervation
Authors: Bailly Y. , Dunel‐Erb S. , Laurent P. 
Published: February 2005

AbstractThe neuroepithelial cells (NECs) of the fish gill filament share several morphofunctional features with the cells of the neuroepithelial bodies in the lungs of air‐breathing vertebrates. In the present study, a detailed indolamineimmunocytochemical analysis of the branchial neuroepithelial cells and nerves was undertaken in non‐teleost and teleost species, with particular emphasis on the latter. In the rainbow trout, Oncorhynchus mykiss, the chemical degeneration of either catecholaminergic (by 5‐ and 6‐hydroxydopamines) or indolaminergic (by 5,6‐dihydroxy‐tryptamine) innervations associated with the NECs was studied using electron microscopy.In teleosts, the NECs are located primarily on the distal half of the filament. In the trout particularly, these cells are innervated mainly by non‐indolaminergic nerves taking up sympathetic neurotoxins. The proximal half of the filament contains isolated NECs innervated additionally by intrinsic indolaminergic neurons.Serotonin‐like immunoreactivity of the NECs is evident in the granular vesicles packed within the basal soma and processes which surround non‐vascular and vascular smooth muscles in the filament. Apical processes from the neuroepithelial cells occasionally contact the water on the surface of the filament epithelium. The secretory function of the NECs is discussed with reference to the probable involvement of serotonin in the modulation of fish gill function. In addition, their connections with both central and branchial nervous system suggest a possible chemoreceptor role. © 1992 Wiley‐Liss, Inc.
The micocirculation of bone and marrow in the diaphysis of the rat hemopoietic long bones
Authors: De Saint‐Georges L. , Miller S. C. 
Published: February 2005

AbstractThe nature of the microcirculation of the diaphyseal portion of long bones and the adjacent bone marrow is poorly understood. The purpose of this study was to describe the blood supply in the diaphyseal cortex and the relationship of the bone vascular circulation to that of the bone marrow in the growing rat. India ink‐gelatin was infused in the arterial system of 3‐month‐old rats and the vascularization was determined from histological sections. In some studies the periosteal circulation was blocked but the nutrient and metaphyseal arteriole systems were left intact. In the growing rat, most of the vascular flow appears to be centripetally through the diaphyseal cortex and this appears to be the primary blood supply for the adjacent bone marrow. The India ink traversed the cortex and entered the marrow through osteal canals at the endocortical surface. At the marrow‐endocortical bone surface interface, ink exiting from the osteal canals filled the adjacent marrow sinusoids in what appeared as “bush‐like” structures. From the bone marrow the ink appeared to drain into the central vein. Some arterioles from the nutrient system were found to penetrate the inner two thirds of the cortical bone and then re‐enter the bone marrow. The centripetal flow of blood and the importance of the cortical flow for perfusion of the hemopoietic tissue was further documented when periosteal flow was obstructed. In this situation, the cortical bone and adjacent bone marrow were not perfused while the nutrient system and central vein were filled with ink. These results show that in the growing rat, the diaphyseal circulation is almost entirely centripetal and the adjacent hemopoietic tissues are perfused mostly with blood that must first traverse the cortical bone. © 1992 Wiley‐Liss, Inc.
Skeletal malformations in hatchery reared Rana perezi tadpoles
Authors: Martínez Irene , Álvarez Rafael , Herráez Inmaculada , Herráez Paz 
Published: February 2005

AbstractSkeletal malformations at metamorphosis in Rana perezi tadpoles reared in culture have been studied. Tadpoles were fed ten artificially compounded and fresh diets and kept at two different temperatures. Animals were maintained in fiberglass tanks. Bone damages are related to the nourishment with compound diets. Tadpoles fed such diets showed variable percentages of scoliosis, kyphosis, luxations, and subluxations in the hind limbs, aplasia in phalanges, and wide failures of ossification. The data suggest the origin of the lesions is a deficiency in some compounded diets that could alter collagen metabolism during skeletal adjustments at metamorphosis. © 1992 Wiley‐Liss, Inc.
The surface lamina of the articular cartilage of human zygapophyseal joints
Authors: Giles L. G. F. 
Published: February 2005

AbstractLiterature referring to the conflicting results of investigations into the possible existence and composition of the lamina splendens is reviewed. Two hundred micrometer thick histological sections from 80 human cadaveric lower lumbar zygapophyseal joint articular cartilages were examined by ordinary light and darkfield microscopy. The findings illustrate what appears to be an acellular surface lamina on the opposing cartilaginous surfaces. No speculation is made regarding the possible physiological significance of the lamina based on this anatomical study. © 1992 Wiley‐Liss, Inc.
Insulin improves survival but does not maintain function of cultured chick wing bud apical ectodermal ridge
Authors: Boutin Eugenie L. , Fallon John F. 
Published: February 2005

AbstractPreviously we demonstrated that high levels of insulin (5 μg/ml) permit the survival of isolated chick apical ectodermal ridge in culture (Boutin and Fallon, Dev. Biol., 104:111–116, 1984). Here we address whether lower levels of insulin or insulin‐like growth factors (IGFs) can also improve the survival of cultured apical ectodermal ridge and whether ridge function is maintained along with ridge survival. Neither IGF I nor IGF II (100 ng/ml) decreased ridge cell death; however, cell death was significantly decreased with 50 ng/ml insulin. No further improvement was obtained in the presence of both IGF I and insulin. These data suggest that insulin improved the survival of the isolated apical ectodermal ridge by binding its own receptor. To test for the maintenance of function, stage 20 ridges were cultured for 0, 6, 12, 18, or 24 hr with or without insulin (5 μg/ml or 5 ng/ml) and used to make recombinant limbs. Isolated ridges cultured for 12 hr or more produced fewer outgrowths and these were rarely distally complete. The medium in which the ridges had been cultured did not influence ridge activity, despite the major differences in cell survival. Recombinants made with ridges cultured with limb mesoderm for 18 hr did not yield outgrowths as often as those with freshly isolated ridges, but most of the limbs that did form were distally complete. These results suggest that the decline in function of cultured, isolated apical ectodermal ridge was not due merely to ridge cell death but rather, at least in part, to its separation from limb mesoderm. © 1992 Wiley‐Liss, Inc.
Chondroclasts and endothelial cells collaborate in the process of cartilage resorption
Authors: Lewinson Dina , Silbermann Michael 
Published: February 2005

AbstractThe condylar cartilage of the young rat is a major growth center of the craniofacial complex. Differences between the mechanism that results in bone formation from growth centers in the epiphyseal plates of long bones are dictated primarily by the different character of the mineralization of the cartilage. In this ultrastructural study we demonstrate that the terminal hypertrophic chondrocytes undergo apoptosis and disintegration while simultaneously chondroclasts dissolve gaps in the calcified cartilage that engulfs them. The latter are also phagocytizing debris of the chondrocytes. The chondroclasts are intimately followed by tube‐forming endothelial cells that most probably coalesce to create extensions of the invading capillaries into the evacuated lacunae. The chondroclasts have ultrastructural features similar to osteoclasts. They are multinucleate, are rich in mitochondria and vacuoles, form clear zones that adhere to the spicules of the calcified cartilage, and also form a sort of ruffled border. The latter is not as elaborate and orderly arranged as is known from osteoclasts. The capillaries that follow orient the stroma cells to the evacuated lacunae and, together with the calcified cartilaginous scaffold, supply the adequate environmental conditions for the stroma cells to differentiate into osteoblasts and to build up trabecular bone. © 1992 Wiley‐Liss, Inc.
Reinitiation of gonocyte mitosis and movement of gonocytes to the basement membrane in testes of newborn rats in vivo and in vitro
Authors: McGuinness Michael P. , Orth Joanne M. 
Published: February 2005

AbstractMovement of postnatal gonocytes to the periphery of the seminiferous cord, where they contact the basement membrane, and resumption of mitosis by these previously quiescent cells are likely to be critically important in establishing spermatogenesis in neonatal rats. We used several approaches both in vivo and in vitro to determine precisely when each of these two events begins, to study their temporal relationship to each other, to determine whether gonocyte division is a prerequisite for relocation or vice versa, and to probe the source of factors initiating and/or regulating these events. Both light and electron microscopy were used to determine that the first gonocytes make contact with the basement membrane on postnatal day 4, while quantitative autoradiography following 3H‐thymidine administration in vivo indicated that the first gonocytes to re‐initiate cell division do so one day earlier, on day 3, and that the percentage of gonocytes dividing remains at a stable level through day 5. Moreover, we organ‐cultured neonatal testes from birth onwards in the presence of defined, serum‐ and hormone‐free medium and determined that both proliferation and relocation of gonocytes begin and continue in vitro as in vivo. This observation argues against involvement of extratesticular factors in stimulating gonocyte relocation and division, and points to the testis itself as the most likely source of agent(s) regulating postnatal maturation of these cells. In other, similar incubations we included 3H‐thymidine for varying periods of time to label either those gonocytes that are the first to divide or all gonocytes that divide during the first 48 hr of culture. From these studies, we confirmed that the first gonocytes to divide do so while separated from the basement membrane and found that, although some cells divide before moving peripherally, others do not. © 1992 Wiley‐Liss, Inc.