bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of HCG on pinocytosis within the canine inter‐sertoli cell tight junction. A preliminary report
Authors: Connell Carolyn J. 
Published: February 2005

AbstractThe role of tight junctions in permeability barriers is now well established. Other roles for this junction have been postulated, but have not been demonstrated. In both adult and prepubertal dogs, stimulation with human chorionic gonadotropin (hCG) results in an increased number of pinocytotic vesicles on the membrane faces enclosed by tight junctions within the inter‐Sertoli cell junctions of the testis. It is suggested that these membranous regions, protected from the normal flow of intercellular fluids, may act as regions of selective intercellular exchange.
A retropharyngeal approach to the avian brain stem
Authors: Vielvoye G. J. , Freedman S. L. , Voogd J. 
Published: February 2005

AbstractThe surgical steps used to expose the ventral surface of the chicken's rhombencephalon are detailed. Both acute and chronic experimental preparations can be obtained with this technique. Text material and illustrations provide information on the morphological relationships of the brain stem, skull and other significant structures encountered during the operative procedure.
The assessment of prenatal age from the crown‐rump length determined ultrasonically
Authors: Drumm J. E. , O'Rahilly R. 
Published: February 2005

AbstractCrown‐rump lengths determined ultrasonically in vivo and in utero in cases of known postovulatory age (33–86 days) agree well with those in length/age tables in current embryological usage. Within the embryonic period proper, however, for a given age, the ultrasonic lengths are usually 1 to 5 mm longer than those of fixed specimens. The probable reasons for this are discussed.
A histochemical study of aldehyde fuchsin‐positive material and “high‐esterase cells” in the pineal gland of the Mongolian gerbil
Authors: Japha Joan L. , Eder Thomas J. , Goldsmith Eli D. 
Published: February 2005

AbstractThe pineal gland of the Mongolian gerbil consists of a superficial gland, stalk and deep pineal. The deep pineal differentiates postnatally.Histochemical studies of the superficial pineal gland indicate that it may be involved in the secretion of protein. Presumptive secretory material visualized by aldehyde fuchsin (AF) and chrome hematoxylin was observed along the course of blood vessels and among the pinealocytes. The distribution and texture of the AF‐positive material was distinctive. It did not correspond to the pattern and texture of material stained with PAS, Sudan Black or acid orcein. Staining with AF was markedly reduced after incubation with trypsin, indicating that the AF‐positive material is at least partially protein. The amount of stainable material increased with age.The AF‐positive material was observed in what appeared to be interstitial or glial cells and processes, and in the processes of perivascular cells.Cells and fibrous processes with high non‐specific esterase activity (“highesterase cells”) were observed among the pinealocytes and along the course of blood vessels. The distribution of the “high‐esterase cells” and the morphology and texture of their esterase‐containing processes were remarkably similar to the morphology and distribution of the material that stained with AF. It may be that the “high‐esterase cells” contain AF‐positive material. The “high‐esterase cells” hydrolyzed both alpha‐naphthyl acetate and alpha‐naphthyl butyrate. The pinealocytes hydrolyzed only alpha‐naphthyl acetate. The “high‐esterase cells” appear to form a distinct class of cells within the superficial pineal gland. They are tentatively identified as a type of glial cell.
Light and electron microscopic observations on noradrenergic nerves and striated muscle cells of the guinea pig urethra
Authors: Dixon J. S. , Gosling J. A. 
Published: February 2005

AbstractNeurohistochemical and electron microscopic techniques have been used to determine the arragement and distribution of noradrenergic nerves and striated muscle in the wall of the guinea pig urethra Fluorescent, catecholamine ‐ containing nerves were observed among striated muscle cells only in the junctional zone between an inner layer of smooth muscle and an outer layer of striated cells. In this region considerable intermixing of the two types of muscle cell occurred Electron microscopy has shown that noradrenergic terminal regions containing characteristic small dense‐cored vesicles were invariable associated with smooth muscle cells; such nerves were never observed forming neuroeffector relationships with striated cells. These findings indicate that noradrenergic ‘sympathetic’ fibers are not directly involved in the functional control of urethral striated muscle.
Observations on the morphological heterogeneity of WI‐38 cells
Authors: Wolosewick John J. , Porter Keith R. 
Published: February 2005

AbstractWI‐38 cells of intermediate and late‐passage cultures were examined by light microscopy, scanning, conventional transmission and high voltage electron microscopy for evidence of heterogeneity among the cells within a single culture. Two morphologically distinct cell sizes and shapes were noted in all passages, (1) a typical fibroblastic type, and (2) a much larger, non‐fusiform type. The larger cells generally had a nucleus that was positioned to one side of the bulk of the cytoplasm. The smaller was consistently fusiform with a centrally placed nucleus. The surfaces of intermediate‐passage cells were uniform in showing small microvilli and cortical pits but were otherwise smooth and without distinctive features. The late‐passage cells, on the other hand, were consistent in showing numerous blebs and marginal ruffling. The internal structure of these cells in all passages studied was complicated by many age‐related changes. The observations indicate that there is in WI‐38 cells a high degree of intraculture heterogeneity. An awareness of this is important in studies which characterize the biochemical properties of this cell strain.
Age‐related variations in hepatic regeneration and erythropoietin production in the rat
Authors: Naughton Brian A. , Piliero Joseph A. , Kruger Richard E. , Birnbach David J. , Roy Martin , Piliero Sam J. , Gordon Albert S. 
Published: February 2005

AbstractErythropoietin (Ep) is produced mainly by the liver and spleen during fetal and neonatal periods and by the kidney during adolescent and adult life. The liver is also an important extrarenal producer of Ep in the hypoxic, anephric adult animal. Subtotal hepatectomy results in a substantial elevation in serum Ep levels at 30‐72 hours after hepatectomy in rats subsequently nephrectomized and rendered hypoxic. Ep production is related to the mass of regenerating liver with peak Ep production occurring during times of greatest tissue proliferation. Regenerative and erythropoietic responses to hepatectomy decline with advancing age. Rats undergoing repeated hepatectomies do not recover full liver mass but the initial rate of regeneration increases following each successive hepatectomy. Ep levels decline in anephric hypoxic rats undergoing multiple hepatectomies when compared to sham‐operated controls.
Specializations of the ependyma in the third ventricle of the developing hamster
Authors: Hannah R. S. , Geber W. 
Published: February 2005

AbstractEpendymal cells in the region of the hypothalamic sulcus, hypothalamus, infundibular recess and supraoptic recess exhibit large apical protrusions between day 12 and day 14 post coitus. The ependyma was examined using light microscopy and transmission and scanning electron microscopy. The protrusions contain ribosomes and cytoplasmic matrix. Occasionally other cytoplasmic organelles were found within the protrusions. The protrusions range in shape from a rounded elevation of the apical surface of the ependymal cell to spherical bodies attached to cell surface by a slender stalk. The unique transitory specialization of the ependyma may represent either a neurosecretory or mechanical folding mechanism.
Correlative fluorescence‐immunocytochemical technique for the localization of monoamines and neurophysin (NP)
Authors: McNeill Thomas H. , Hoffman Donald L. , Kozlowski Gerald P. 
Published: February 2005

AbstractA correlative fluorescence‐immnucytochemical technique for the localization of monoamines and neurophysin on sections of freezedried tissues is described. An extensive network of monoamine‐containing perikarya and terminals was found throughout the hypothalamus and median eminence. Immunocytochemical localization of antisera for neurophysin was found in the supraoptic and paraventricular nuclei of the hypothalamus and in both the zona interna and zona externa of the median eminence. This correlative demonstration of both catecholamines and neuropeptides within the same tissue provides a new approach to the study of neurotransmitters and neurohormones and their role in the regulation of the peripheral endocrine system.
Adult monkey coronoid process after resection of trigeminal nerve motor root
Authors: Sarnat Bernard G. , Feigenbaum Joel A. , Krogman Wilton M. 
Published: February 2005

AbstractA smaller or absent coronoid process has been reported, by some investigators but not by others, in growing animals following resection of the temporalis muscle. The trauma of resection, altered function, hemorrhage, scar tissue, and changes in vascularity may have influenced the results. The purpose of this experiment was to observe in adult Macaca mulatta the fully grown coronoid process after decreasing or eliminating neurofunctional activity of the temporalis muscle unilaterally without the trauma of local resection. In two males and three females the motor root of the trigeminal nerve which innervates the temporalis muscle was resected intracranially. In three control animals of both sexes the same surgical procedure was performed except for resection of the nerve. At postmortem, one year later, the temporalis muscle mass was atrophic on the resected side. There were no significant morphological differences, however, between the right and left sides of the mandible, including the coronoid process, regardless of which motor root of the fifth nerve had been resected, which side had been sham‐operated, or sex. An extensive deposit of calculus on the buccal surfaces of the teeth on the operated nerve side was a consistent, conspicuous finding.
A morphometric examination of type II alveolar epithelial cells in normal and isolated‐perfused dog lungs
Authors: DeFouw David O. , Berendsen Peter B. 
Published: February 2005

AbstractThe volume densities of type II alveolar cell cytoplasmic organelles and alveolar surface densities were estimated by established stereologic procedures. The morphometric measurements were obtained from normal dog lungs (in situ) and isolated dog lungs perfused for 30‐minute, 1‐hour, and 2‐hour periods. The type II cell lamellar body volume densities and the alveolar surface densities progressively decreased as the times of perfusion were increased. The volume densities of the granular and agranular endoplasmic reticulum progressively increased during the periods of perfusion. These morphometric parameters from lungs in situ and isolated lungs suggest that changes occur in pulmonary surfactant synthesis and activity during perfusion. It is further postulated that progressive increases in the rates of surfactant removal and/or inactivation during perfusion may contribute to spontaneous edema in lungs isolated for periods exceeding two hours. The morphologic and physiologic integrity of isolated perfused lung preparations, widely used as models of lungs in vivo, in situ requires further evaluation.
Age related differences in binding of Concanavalin a to plasma membranes of isolated neurons
Authors: Bennett Kimberly D. , Bondareff William 
Published: February 2005

AbstractNeurons isolated from the lateral vestibular nucleus of young adult and senescent Fischer‐344 rats were incubated with fluorescamine‐labelled Concanavalin A (fl‐Con A) alone, or following incubation in trypsin or Vibrio cholerae neuraminidase. They were then observed and photographed. Microdensitometric analysis of fluorescence micrographs showed that senescent rat neurons were significantly more fluorescent than those from young adult rats. Additionally, either patches or caps of fl‐Con A were seen on the surface of neurons from senescent rats, while most young adult rat neurons bound fl‐Con A uniformly.Pretreatment with trypsin or neuraminidase had no effect on the amount of fluorescence on the surface of senescent rat neurons, and only a slight effect on the surface distribution. Trypsin and neuraminidase treatments caused a significant increase in fluorescence on the neuronal plasma membranes of young adult rats and a rearrangement of the binding pattern in the majority of neurons observed.
A study by light and scanning electron microscopy of the lining epithelium of the guinea pig bladder following artificial ulceration
Authors: Wong Y. C. , Martin B. F. 
Published: February 2005

AbstractFollowing artificial ulceration of the guinea pig bladder epithelium, study by light microscopy showed that mitotic activity occurs within 24 hours in the basal layer of the remaining epithelium, which leads to thickening, disorganization and cell shedding. At the ulcer margin, the epithelium forms a rolled edge, from the extremity of which a two‐layered sheet of flat cells grows over the edematous ulcer bed, and the ulcer site is protected during dilation of the bladder by localized muscle spasm. Healing is effected within about one week, as the mitotic activity declines. Organization of the new epithelium commences at the periphery and the cells acquire glycogen and alkaline phosphatase. Study by SEM, which included normal bladders, confirmed that new epithelium spreads from a rolled epithelial edge, and also showed that cells undergoing rejection have globular profiles with surface microvilli. The immature epithelial cells are markedly distorted from mutual pressure during migration and their surfaces show only short microvilli. Ulcers heal after four to seven days, depending on size, and the new cells rapidly assume the pentagonal and hexagonal outlines and the reticular pattern of surface ridges, characteristic of mature surface cells. The ridges apparently develop by fusion of rows of microvilli. By the tenth day it is difficult to identify the original ulcer site.
Ultrastructural characterization of the manchette microtubules in the seminiferous epithelium of the mouse
Authors: Wolosewick John J. , Bryan John H. D. 
Published: February 2005

AbstractIn the mouse seminiferous epithelium four sites of formed microtubules (MTS) are axonemes and manchettes of spermatids, Sertoli‐cell cytoplasm, and spindles of dividing cells. Various experimental treatments indicate that the manchette MTS are different from other formed MTS. Fixation in 1% osmium tetroxide yields good preservation of axonemal MTS, varying degrees of preservation of manchette MTS, but no preservation of spindle or Sertoli‐cell MTS. Cell‐suspension, and intact‐tubule cultures subjected to 0–4°C or 50°C exhibit a breakdown of spindle and Sertoli‐cell MTS while manchette and axonemal MTS remain intact. Cell suspensions exposed to Colcemid or colchicine show no MTS in Sertoli and dividing cells; axonemal MTS are unaffected while in the manchette there is an increase in cross‐bridging between MTS. Cell suspensions treated for 120 minutes with vinblastine sulfate do not show MTS in the Sertoli cells, but crystals presumed to be microtubule protein are present after 15 minutes of exposure. Spindle MTS are dismantled but vinblastine‐induced crystals are not present even after 120 minutes of exposure. The manchette MTS are dismantled by vinblastine in a proximal direction from their distal limits. This is accompanied by the formation of crystals of microtubule protein in the spermatid cytoplasm, while axonemal MTS are unaffected. Vinblastine and Colcemid used in combination cause the disruption of Sertoli‐cell MTS after 15 minutes, spindle MTS after 30 minutes and formation of crystals after 60 minutes of exposure. The manchette MTS are disassembled, the pattern is disrupted and increased numbers of cross‐bridges are seen. These findings indicate that the manchette MTS might be intermediate‐type microtubules since they exhibit the reactions of both cytoplasmic and flagellar‐type MTS.
Variations in intrafusal fiber size within histochemically identified types of intrafusal fibers in the pigeon
Authors: Maier Alfred 
Published: February 2005

AbstractThe myofibrillar adenosine triphosphatase reaction with acid preincubation allowed the identification of three types of intrafusal fibers in pigeon flexor carpi ulnaris muscle spindles. Measurements of cross‐sectional areas at the polar region showed much overlap in fiber size among populations of each type.
Electron microscopy of the connective tissues between longitudinal and circular muscle of small intestine of cat
Authors: Taylor A. B. , Kreulen David , Prosser C. L. 
Published: February 2005

AbstractElectrotonic spread of applied potentials was observed between longitudinal and circular muscle layers of the small intestine with no rectification. Nexal junctions were demonstrated between muscle fibers of each layer. Connective tissue cells bridged between the two muscle layers. These showed structural characteristics of fibrocytes and of interstitial cells. Some nexuses were seen between connective tissue cells and between these cells and muscle fibers of each layer but in most junctions the membranes were 10–18 nm apart. Since connective tissue can serve for electrical conduction between cultured heart cells and since electrical properties of intestinal muscle permit transmission with low degrees of coupling, it is suggested that interstitial cells and fibrocytes may electrically couple longitudinal and circular muscle layers of cat intestine.
Relative volume of sertoli cells in monkey seminiferous epithelium: A stereological analysis
Authors: Cavicchia Juan Carlos , Dym Martin 
Published: February 2005

AbstractTechniques of quantitative stereology have been utilized to determine the relative volume occupied by the Sertoli cells and germ cells in two particular stages (I and VII) of the cycle of the seminiferous epithelium. Sertoli cell volume ranged from 24% in stage I of the cycle to 32% in stage VII. Early germ cells occupied 3.4% in stage I (spermatogonia) and 8.7% in stage VII (spermatogonia and preleptotene spermatocytes). Pachytene spermatocytes occupied 15% (stage I) and 24% (stage VII) of the total volume of the seminiferous epithelium. In stage I the two generations of spermatids comprised 58% of the total epithelium by volume, whereas in stage VII, after spermiation, the acrosome phase spermatids occupied 35% of the total seminiferous epithelial volume.
A light and scanning electron microscopic study of the basilar papilla in the salamander, Ambystoma tigrinum
Authors: White James S. 
Published: February 2005

AbstractThe basilar papilla and basilar recess of Ambystoma tigrinum have been investigated by light and scanning electron microscopy. The recess is an evagination of the lagena, and is invested externally by dense periotic connective tissue, except over a thin area of one wall abutting against a periotic diverticulum communicating with the periotic sac. The surface and histological features of the non‐sensory lining epithelium are described. The basilar papilla occupies both slopes of an elevation adjacent to the thin wall of the recess, and consists of 40 to 80 sensory cells interposed between sustentacular cells. The sensory cells are innervated by 30 to 40 nerve fibers exhibiting two ranges of diameter, and they are capped by typical ciliary bundles that are taller at the center of the receptor than at its periphery. Bundles in the proximal and distal halves of the papilla are polarized, respectively, toward the saccule and toward the thin wall in contact with the periotic diverticulum; this divergent pattern of polarization has not been reported previously in the basilar papilla of other vertebrates. A tectorial body overlies only the bundles in the distal half of the receptor, and is attached to both the neuroepithelium and the opposite wall of the recess. Functional considerations are discussed, and comparisons are made with conditions reported in frogs and toads. The findings suggest that the basilar papilla and recess in caudate and anuran amphibians arose from common precursors and probably function in a similar manner.
Effect of vitamin A and methylprednisolone on canine prostate in organ culture
Authors: Fischer Theodore V. , Kahn Raymond H. , Burkel William E. , Vinter David W. , Herwig Karl R. 
Published: February 2005

AbstractOrgan explants from the canine prostate with and without methylprednisolone pretreatment were cultivated for ten days in Trowell's T‐8 medium or medium supplemented with testosterone and/or vitamin A. Upon termination of the experiments, explants were fixed and examined histologically. All glands from the most central section of each explant were graded according to epithelial type, and from these grades the proportion of acini with maintained columnar cells was calculated for each explant. Stromal cellular maintenance was also estimated. While a small proportion of explants from the vitamin‐treated and methylprednisolone‐pretreated groups showed epithelial maintenance, a combination of these treatments significantly increased such maintenance. Stromal maintenance was enhanced with methylprednisolone pretreatment but not by vitamin A. These results are in accord with the hypothesis that methylprednisolone acts to stabilize the lysosomal membrane, thus protecting tissue against the effects of ischemic shock. In protected explants vitamin A is able to maintain a columnar glandular epithelium. In a subsequent experiment a series of linoleic acid dosages was tested in the presence or absence of vitamin A. In neither case was this fatty acid of value in improving epithelial or stromal maintenance.
Synthesis and migration of glycoproteins in cells of the rat thymus, as shown by radioautography after 3H‐fucose injection
Authors: Bennett Gary 
Published: February 2005

AbstractYoung male rats received a single intravenous injection of 3H‐fucose and were killed after various time‐intervals. Light‐ and electron‐microscopic radioautographic studies of the thymus in animals killed shortly after injection showed that all of the different cell types present incorporated 3H‐fucose label. The heaviest uptake occurred in macrophages and in hypertrophic epithelial cells located near the cortico‐medullary border. Somewhat lighter incorporation was observed in medullary and cortical stellate epithelial cells and in cells designated as special cells, while the lightest reaction appeared over lymphocytes.In all cells the label was localized initially to the Golgi apparatus, where, presumably, it was incorporated into glycoproteins. With time, some of the labeled putative glycoproteins in all cell types migrated to the plasma membrane. In macrophages, much of the label migrated to lysosomal bodies, while in the special cells the label migrated to dense bodies which may also be of lysosomal nature. In stellate and hypertrophic epithelial cells much of the label migrated to characteristic vacuoles. The possible relationship between the observed glycoprotein synthesis in these cells and hormone production is discussed.