bluuebunny/crossref_metadata_2025_split huggingface dataset:
An immunofluorescent analysis of lectin binding to normal and regenerating skeletal muscle of rat
Authors: Gulati Adarsh K. , Zalewski Andrew A. 
Published: February 2005

AbstractTen different fluorescein‐conjugated lectins of various known sugar specificities were used to study cell surface glycoconjugates of normal and regenerating rat skeletal muscle. In normal muscle, Canavalia ensiformis agglutinin, Triticum vulgaris agglutinin (wheat germ agglutinin, WGA), Ricinus communis agglutinin‐I, and Maclura pomifera agglutinin bound strongly to the endomysial region of the myofibers. No binding was observed in the cytoplasm of the myofibers. Other lectins (Dolichos biflorus agglutinin, Griffonia simplifolia agglutinin I and II, Ulex europaeus agglutinin, Arachis hypogaea agglutinin, Glycine max agglutinin) bound very poorly or not at all in the normal muscle. Skeletal muscle degeneration and regeneration was induced by autotransplantation of the extensor digitorum longus muscle. In the transplanted muscles, the endomysial lectin binding of the degenerating myofibers became weak and lacked continuity, indicating a breakdown of the endomysium. Of all the lectins tested, only WGA revealed intense binding in the myogenic zone of regenerating muscle. As the regeneration progressed, this WGA binding became restricted to the new endomysium. In completely regenerated muscle, binding of all lectins was similar to that seen in normal muscle. The specific binding of WGA to the myogenic zone may be important in identifying factors or glycoconjugates, which constitute a favorable environmnt for skeletal muscle regeneration.
The renin‐angiotensin system in the rat anterior pituitary: Colocalization of renin and angiotensin II in gonadotrophs
Authors: McKenzie James C. , Naruse Kiyoko , Inagami Tadashi 
Published: February 2005

AbstractDiscovery of components of the renin‐angiotensin system (RAS) in the adenohypophysis of several species has prompted speculation concerning the location and possible function of a pituitary RAS. Although both renin and angiotensin II have been localized within the rat adenohypophysis, their colocalization has not been previously demonstrated within the same cells. In the present study, immunohistochemical staining by the avidin‐biotin‐peroxidase complex technique was used to demonstrate the coexistence of renin and angiotensin II in adenohypophyseal cells identified morphologically and immunocytochemically as gonadotrophs. These results support the existence of an adenohypophyseal RAS, at least part of which is under intracellular control. The influence of this system on control of fluid balance, blood pressure, and the secretion of other hypophyseal hormones is discussed.
Supplemental clinical dissections for freshman gross anatomy
Authors: Cahill Donald R. , Cramichael Stephen W. 
Published: February 2005

AbstractThis paper describes a series of nine short clinically oriented dissection exercises as supplements for freshman gross anatomy courses. These procedures heighten and focus student interest, and they do not extensively lengthen the time required to accomplish the regular dissection assignments. The exercises are: (1) lumbar puncture, (2) anterior approach for shoulder arthroplasty, (3) acromioclavicu‐lar dislocation, (4) fenestration of the diaphragm, (5) appendectomy, (6) cholecystectomy, (7) display of the facial nerve as in parotidectomy, (8) posterior approach for hip arthroplasty, and (9) injuries to the knee ligaments and meniscectomy.
Filipin‐sterol complexes in the plasma membrane of zebrafish spermatozoa
Authors: Kessel R. G. , Tung H. N. , Roberts R. 
Published: February 2005

AbstractThe presence and distribution of filipin‐sterol complexes in the plasma membrane of zebrafish (Brachydanio rerio) sperm was investigated. The zebrafish sperm plasma membrane, treated with freeze‐fracture techniques, is seen to contain a multitude of intramembranous particles that, in a specific region of the posterior part of the sperm head, are organized into unusual particle arrays that appear as simple hexagons or parallelograms. The polyene antibiotic filipin forms complexes with 3‐β‐OH sterols to produce characteristic protrusions and pits in membranes that are readily observable in freeze‐fracture replicas. Numerous filipin‐sterol complexes were found to populate the sperm plasma membrane, and the complexes exhibited variability in their distribution in different sperm. This appears to be the first illustrated example of an acrosomeless sperm that exhibits a high concentration of filipin‐sterol complexes. In contrast, the unique grating formed by the intramembranous particles as well as variable amounts of membrane surrounding the unusual particle arrays were always free of the filipin‐sterol complexes. Thus, while cholesterol appears to be present in the plasma membrane of the zebrafish sperm, it is not apparent in the highly differentiated region of the membrane based on the observed distribution of the filipin‐sterol complexes.
Immunohistochemical observation on substance P in regenerating taste buds of the rat
Authors: Nishimoto Tatsuya , Ichikawa Hiroyuki , Wakisaka Satoshi , Matsuo Saburo , Yamamoto Katsuhiko , Nakata Terukuzu , Akai Michio 
Published: February 2005

AbstractThe present study was performed to investigate the relationship between substance P‐positive (SP‐positive) nerve fibers and regeneration of taste buds in the foliate papillae of the rat by means of immunohistochemistry. It was confirmed by neurotomy that taste buds in the foliate papillae of the rat were innervated mostly (90%) by the glossopharyngeal (IXth) nerve and partly (10%) by the chorda tympani. In this experiment, the IXth nerve was sectioned distal to the petrosal ganglion. The rats were sacrificed at various intervals from 20 days to 80 days after the operation. In the course of denegeration and disappearance of taste buds, both SP‐positive fibers and taste buds disappeared completely from the posterior folds of the foliate papillae 7 days after the operation. Within 22 days, regenerated SP‐positive fibers began to appear in the lamina propria, and following the penetration of the fibers into the epithelium, taste bud anlagen reappeared at the bottom of the trench, and in the posterior folds at 24 days. The process of new taste bud formation extended toward the apex of the trench and to the anterior folds, which seemed to follow the regeneration in the nerve trunk. Quantitative data showed a gradual increase in the number of taste buds and taste buds containing SP‐positive fibers. These findings indicate that SP might have a role in regeneration of taste buds.
Rapid formation of gap‐junction‐like structures induced by glycerol
Authors: Kachar Bechara , Reese Thomas S. 
Published: February 2005

AbstractIntercellular junctions, in identified in freeze‐fracture by narrowing of the intercellular gap and codistribution of P‐face membrane particles, proliferate during incubation of excised rat prostate tissue in 30% glycerol solution. These junctions fulfill the criteria used to identify gap junctions in freeze‐fracture replicas with respect to the size and uniformity of their component particles, the codistribution of the particle aggregates on P‐faces of adjacent membranes, and the narrowing of the extracellular cleft at the junction. These gap‐junction‐like structures form on the lateral surfaces of epithelial cells, where they are normally scarce, within minutes after exposure to glycerol. Glycerol‐induced junction formation is not blocked by DNP, a metabolic uncoupler, or by cycloheximide, a protein synthesis inhibitor. Newly formed junctions occur initially in clusters and the number per cluster decreases as individual junctions become larger with longer periods of incubation, suggesting that the clusters coalesce. The structural changes that precede and accompany the formation of these junctions at early times of incubation are comparable to the changes reported to precede the formation of gap junctions accompanying hormonal treatment, development, and other means of natural induction.
Immunofluorescent localization of an androgen‐dependent isoenzyme of prostatic acid phosphatase in rat ventral prostate
Authors: Terracio Louis , Rule Allyn , Salvato John , Douglas William H. J. 
Published: February 2005

AbstractIsoenzymes of rat ventral prostate (RVP) acid phosphatase were isolated and partially purified by ultracentrifugation, Sephadex G‐100 column chromatography, and isoelectric focusing. Antisera were raised to the isoenzymes of prostatic acid phosphatase by immunization of New Zealand white rabbits. Rabbit antisera reacting specifically to homologous but not heterologous isoenzymes of acid phosphatase were then reacted with a variety of tissues using indirect immunofluorescence. The tissues included prostate, spleen, bone marrow, liver, kidney, salivary gland complex, small intestine, and adrenal glands. An antiserum against a RVP acid phosphatase isoenzyme with a pI of 4.5 (A‐PAP) localized acid phosphatase only in the supranuclear region of rat ventral prostate epithelial cells, and did not react with acid phosphatase in any of the other organs tested. A‐PAP did not localize acid phosphatase in the ventral prostate from rats 14 days after castration. A‐PAP did localize acid phsophatase in the ventral prostate from castrated animals that were treated with testosterone. These results indicate the A‐PAP localized an androgendependent isoenzyme of acid phosphatase in RVP epithelial cells that may be secretory in nature. This antiserum should prove to be an ideal marker for studies involving hormonal regulation of prostatic epithelial function in vivo and in vitro.
A functional and structural heterogeneity is formed among fetal rat hepatocytes during culture
Authors: Asada‐Kubota Mari 
Published: February 2005

AbstractFetal rat hepatocytes (22‐day‐old, full‐term) in vivo were homogeneous in ultrastructure and glucose 6‐phosphatase (G6Pase) distribution throughout the liver acinus. These cells were isolated and cultured for 17 days in Williams medium E containing 10% fetal calf serum, dexamethasone, insulin, and glucagon. Heterogeneity among hepatocytes appeared progressively during culture. There were variations in numbers of binucleated cells, cytoplasmic ultrastructure (e.g., in the distribution of glycogen and the quantity of ultrastructure (e.g., in the distribution of glycogen and the quantity of mitochondria), and intensity of histochemical reactivity for G6Pase. The cells could be classified generally into two types: type I cells had some characteristics of periportal hepatocytes and type II cells those of centrolobular hepatocytes in in vivo adult liver. The results show that a functional and structural heterogeneity can be formed among fetal hepatocytes in monolayer culture without differences in supply of oxygen, nutrients, and hormones. A hidden heterogeneity might already exist among hepatocytes in full‐term fetuses even though it cannot be detected ultrastructurally or cytochemically.
Partial denervation of the ovaries by transection of the suspensory ligament does not inhibit ovulation in rats treated with pregnant mare serum gonadotropin
Authors: Selstam Gunnar , Norjavaara Ensio , Tegenfelt Tomas , Lundberg Sven , Sandström Christina , Persson Sven‐ÅKe 
Published: February 2005

AbstractAdrenergic nerves reach the ovary via two routes: along the arteries to the ovary and via the suspensory ligament. Results from earlier investigations suggest that denervation of the nerves along the arteries does not influence the ovulatory process. In the present study we have examined whether denervation by transection of the ovarian suspensory ligament influences the ovulatory process.Partial denervation of the ovary by transection of the ovarian suspensory ligament, sham operation, or only anesthesia were performed on immature 25‐day‐old rats. To induce ovulation, pregnant mare serum gonadotropin (PMSG) was injected in the morning (0800‐0930), when the rats were 26 days old. This PMSG treatment normally induces ovulation around 0200 in the early morning of day 29 with subsequent formation of corpora lutea. Rats were killed 5–8 hr, 3 days, and 5 days after this ovulation time.Ovarian interstitial norepinephrine levels were markedly decreased after transection of the suspensory ligament. Ovulations had occurred in all denervated, as well as sham‐operated, and control rats. The various groups did not differ in the number of ovulations per rat. Thus, the adrenergic nerves in the suspensory ligament appear not to be necessary for ovulation. Whether catecholamines themselves play a role in the ovulatory process cannot be elucidated from this experiment, since the norepinephrine content in the ovary was not totally depleted. It seems unlikely that adrenergic nerves reach the corpus luteum via the suspensory ligament, since transection of this structure did not change the luteal content of norepinphrine.
Small‐granule APUD cells in relation to airway branching and growth: A quantitative, cartographic study in syrian golden hamsters
Authors: Sarikas Stephen N. , Hoyt Richard F. , Sorokin Sergei P. 
Published: February 2005

AbstractSmall‐granule APUD cell clusters and their clear‐cell precursors were mapped in serial 2‐μm glycol methacrylate‐embedded, periodic acid‐Schiff(PAS)‐lead hematoxylin‐stained sections of 13‐, 14‐, and 15‐day fetal hamster lungs. Every sixth section was drawn from a camera lucida projection on tracing paper. Each tracing included the profiles of nonalveolated air passages and the locations of smallgranule cell clusters and solitary clear cells. Airways containing ciliated cells and those surrounded by condensed mesoderm were also labeled. Single clear cells were rare in fetal hamster lung. Of 2,368 endocrine cell loci identified in the three fetal age groups examined, only 14 were single clear cells. A preliminary survey of the entire left and right lungs showed that the pattern of airway and small‐granule cell development in the infracardiac lobe was similar to that occurring in the remainder of the lung; this lobe was accordingly considered a model for the whole lung, and the ontogeny of its small‐granule cell population was quantitated and compared with results of similar quantitative mapping of this lobe in an adult animal (Hoyt et al., 1982a,b). Along the lobar bronchus of the 13‐day infracardiac lobe and proximal portions of its main branches, small‐granule cell clusters occurred most often near airway intersections. As the number and density increased in subsequent fetal stages, small‐granule cell clusters became conspicuous along internodal bronchial segments. In distributing bronchioles, the population density of small‐granule cell clusters decreased between 13 and 14 days but more than doubled by day 15. Unlike human lungs, where centrifugally developing small‐granule cell clusters are firmly established in terminal bronchioles well before birth, most peripheral bronchioles in fetal hamster were devoid of small‐granule cell clusters, even at 15 days, one day before birth. Comparison of numerical population densities in this lobe of fetal and adult lungs indicates that small‐granule cell clusters continue to form past day 15 and suggests that they are considerably more numerous in adult than fetal lung.
Development of hamster tracheal epithelium: II. Cell proliferation in the fetus
Authors: McDowell Elizabeth M. , Newkirk Carnell , Coleman Bill 
Published: February 2005

AbstractProliferation of epithelial cells in the fetal trachea was studied in hamsters, beginning on the 10th gestational day and ending on the 16th day, shortly after birth. The mean mitotic index (MI) was highest on day 10, with no statistical confirmation of a change between days 10 and 11. The MI fell to about 2% on days 12 and 13, and declined thereafter to about 0.3% on day 16. The MIs for dorsal and ventral surfaces were compared and values were similar except on day 10, when ventral exceeded dorsal, and on day 12, when dorsal exceeded ventral, 2.56% and 1.3%, respectively. On days 10, 11, and 12 the epithelium was simple, composed of poorly differentiated columnar cells that proliferated. On day 13 the epithelium was pseudostratified owing to the presence of a few short cells that did not reach to the lumen. Throughout the fetal period, proliferation of columnar cells predominated but division of short (basal) cells increased from 8% to 40% of the total mitotic activity between day 13 and day 15. Proliferation of basal cells then declined, so that on day 16, 84% of all cells in mitosis were columnar. If basal cells divide to make more of themselves they must proliferate rapidly between day 13 and day 15, because they were virtually absent on day 12 but accounted for about 36% of the ventral and 23% of the dorsal epithelial cells on day 16. Based on the results, a hypothetical model is proposed for the formation of pseudostratified mucociliary epithelium. The model proposes that small granule (endocrine) cells, basal cells, secretory cells, and ciliated cells are established from poorly differentiated columnar cells by day 13. Thereafter short basal cells replicate to produce only basal cells, whereas columnar secretory cells replicate to produce secretory cells and ciliated cells. This model will be tested in future studies.
Teratogenic effects of the organophosphate insecticide dicrotophos (Bidrin): Histological characterization of defects
Authors: Garrison James C. , Wyttenbach Charles R. 
Published: February 2005

AbstractWhite Leghorn chicken eggs, specific pathogen free, were treated with the organophosphate insecticide dicrotophos and the early defects thus induced were characterized histologically. Eggs were incubated for 24, 48, 72, or 96 hr, injected with doses of dicrotophos ranging from 250 μg to 2.0 mg per egg, and observed after an additional 48 hr of incubation. Treated embryos displayed general developmental retardation as well as unilateral retardation of the cranial sense organs, the youngest embryos being most severely affected. Many embryos injected with insecticide at 24 hr, and all but one injected at 48 or 72 hr, displayed notochordal folding, usually restricted to the cervical region; most of these also showed deformities of the adjacent spinal cord. Other defects, seen on a less consistent basis, included branching of the neural canal in the lumbar region, bifurcation of the neural epiphysis, deformation of the lens vesicle, and distention of the major blood vessels. The incidence and severity of epiphyseal, lens, and vascular defects were greatest among embryos treated at 24 hr, whereas notochordal and both types of neural defects were greatest among those treated at 48 hr. The incidence and severity of the abnormalities diminished with increasing age such that by 96 hr the only defect noted was a weak notochordal folding in one embryo. To a lesser extent, incidence and severity were dose‐related also. Histological similarities between embryos displaying vascular distention and recently dead treated embryos suggested that this abnormality is a precursor to death. All defects were associated with the presence of the insecticide at the time the affected structures were undergoing initial or early morphogenesis or else the deposition of a supportive sheath, suggesting these activities as targets of the teratogen.
Cytochemical and biochemical glucose 6‐phosphatase activity in skeletal muscle cells of mice
Authors: Watanabe Jun , Kanamura Shinsuke , Kanal Kazuo , Shugyo Yoshihiko 
Published: February 2005

AbstractCytochemical and biochemical glucose 6‐phosphatase (G6Pase) activity and fiber type composition were studied in soleus (SOL) and gastrocnemius (GC) muscles of mice. The SOL is a red muscle which contains numerous type I fibers (60%) and relatively few type II fibers (40%). The GC is a white muscle which contains numerous type II fibers (90–100%) and very few type I fibers (0–10%). In the SOL and GC, cytochemical G6Pase activity was localized in the sarcoplasmic reticulum, lateral elements of triads, myonuclear envelope, and in the endoplasmic reticulum and nuclear envelope of endothelial cells. Differential centrifugation showed that G6Pase activity was recovered in the 105,000g pellet (microsomal fraction). Histochemical enzyme activity in type II fibers was slightly higher than that in type I fibers. Biochemical G6Pase activity in the GC was significantly higher than that in the SOL. The possible functional significance of G6Pase in skeletal muscles was discussed.
Intraventricular blood vessels of the hypothalamus of Salmo gairdneri and Gambusia affinis
Authors: García José M. , Alvarez‐Uría Manuel 
Published: February 2005

AbstractThe ultrastructure of the hypothalamic intraventricular blood vessels is studied in two fish: Salmo gairdneri, a primitive teleost and Gambusia affinis, a modern teleost. Morphological differences found between vessels belonging to the lateral and medial recesses in Salmo are described as well as contrasted with those of Gambusia.The endothelial cells are joined by elaborate tight junctions in both teleosts and also by desmosomes in Gambusia.These vessels are continuous capillaries with pericytes which lack junctional complexes. The perivascular cells of the larger vessels display morphological characteristics of myoid cells.
Cytoplasmic surface ultrastructures of cardiac gap junctions as revealed by quick‐freeze, deep‐etch replicas
Authors: Shibata Yosaburo , Yamamoto Torao 
Published: February 2005

AbstractRapid‐freeze, deep‐etch, rotary‐shadow replica studies were performed to examine the cytoplasmic surface membrane of the cardiac gap junctions of rats, mice, and guinea pigs. In quick‐frozen fresh cardiac muscles, while the nonjunctional cytoplasmic surfaces were covered with filamentous materials, the cytoplasmic surface membrane continuous with freeze‐fractured gap junction plaques were relatively free of such filaments and revealed particulate patterns. After brief rinsing in high K buffer, gap junction membranes showed granular substructures resembling a tiled surface made of round tiles of various sizes. After prolonged rinsing for more than 20 min, however, cytoplasmic surfaces of gap junctions became less particulate but rather smooth. The particulate substructures observed in the rapid‐freeze deep‐etch replicas may correspond to the fuzzy cytoplasmic layer in thin sections and serine protease sensitive peptide moiety in sodium dodecyl sulfate‐polyacrylamide gel electrophoresis reported in isolated cardiac gap junction pellets. These cytoplasmic components, which are absent in liver gap junctions, seem to be specific in cardiac and neural gap junctions and may be related to the large electrical current passed by these junctions.
Ultrastructure and cytochemistry of thyroid lysosomes following subtotal thyroidectomy
Authors: Krupp Patricia P. , Lee Kathleen P. 
Published: February 2005

AbstractFollowing subtotal thyroidectomy, the amount of circulating thyroid hormone decreases and causes an increase in the secretion of thyrotropin (TSH) by the anterior pituitary gland. Serum levels of circulating TSH remain elevated until thyroid secretion returns to normal. In this study we have analyzed the effects of such chronic stimulation of thyroid cells by TSH, with particular emphasis on ultrastructural and cytochemical changes in the lysosomes. Weanling Sprague‐Dawley rats underwent subtotal thyroidectomy and 6 weeks later the residual thyroid tissue was removed and processed for ultrastructural and cytochemical analysis. There were obvious ultrastructural signs of hyperactivity. The cells were hypertrophied and there were colloid droplets in the cells as well as extremely abundant oddly shaped lysosomes. The lysosomes reacted positively for acid phosphatase and for glycoproteins, suggesting that they are secondary lysosomes, ones which have complexed with thyroglobulin prior to release of thyroid hormones from the cells. This tremendous increase in the number of these structures in the cells is similar to that observed under normal conditions during the aging process and suggests a slowdown in the proteolytic degradation of thyroglobulin during long periods of chronic stimulation by TSH.