bluuebunny/crossref_metadata_2025_split huggingface dataset:
“Cholinergic” postsynaptic membranes of bullfrog sympathetic ganglia: Electron microscopy of thin sections and freeze‐fracture replicas
Authors: Watanabe Hiroshi , Washioka Hiroshi , Tonosaki Akira 
Published: February 2005

Abstract“Cholinergic” synapses of the bullfrog sympathetic ganglion cells were investigated with thin sectioning, complementary freeze‐fracturing, and deepetching methods after glutaraldehyde fixation. The protoplasmic (‐fracture) face (PF) of the postsynaptic membrane was characterized by intramembranous particles (IMPs), 3,500/μm 2 in density, consisting of larger particles, 10–12 nm in diameter, and smaller ones, 8–9 nm; the complementary exoplasmic (‐fracture) face (EF) contained larger and smaller IMPs, 750/μm 2 in density, and numbers of pits.By close inspection of the sections and freeze‐fracture replicas at high magnification and with deep‐etching in particular, it was concluded that aggregated IMPs might represent transmembranous components and that the particulate entities existing in the postsynaptic active zones might be larger in number than those exposed to view and counted here in the “cholinergic” synapses. An individual IMP often appeared to consist of five or six subunits arranged in a rosette with a central pit.These findings suggest that the aggregated IMPs, particularly the larger ones, may be closely related to the structure of the nicotinic ACh receptor‐ion channel complex.
Microanatomy of the renicule of Balaena mysticetus
Authors: Henk William G. , Abdelbaki Yahya Z. , Haldiman Jerrold T. , Albert Thomas F. 
Published: February 2005

AbstractRenicules from twelve bowhead whales (Balaena mysticetus) were examined utilizing light, scanning electron, and transmission electron microscopes. The basic organization of the renicule into capsule, cortex, sporta perimedullaris, medulla, and calyx is described. Despite less than perfect preservation resulting from environmental and logistical conditions at the collecting sites, it has been possible to document the basic microstructure of most components of the renicule of this endangered species. Several unusual features were observed. The absence of smooth muscle fibers (other than in vessel walls) from the capsule, sporta perimedullaris, and calyx wall is a departure from what is reported in other cetaceans as is the consistent presence of arcuate arteries in the substance of the sporta perimedullaris. Large subcapsular veins are present but do not appear to represent connecting elements in an alternative venous return through capsular and interrenicular veins. Elastic fibers are seen only in the sporta perimedullaris and the calyx wall, whereas reticular fibers are most abundant in the medullary stroma. Finally, enlarged cells with clear cytoplasm are seen in the tunica media of the glomerular afferent arterioles extending a variable, but always considerable, distance toward the interlobular arteriole. These cells are presumed to represent an extended array of the epithelioid cells common in the afferent arterioles of the juxtaglomerular apparatus of other mammalian kidneys.
Reversibility of the structural effects of pressure overload hypertrophy of cat right ventricular myocardium
Authors: Marino Thomas A. , Brody Eric , Lauva Ines K. , Kent Robert L. , Cooper George 
Published: February 2005

AbstractThe purpose of the present quantitative structural study was to determine whether the histological alterations seen in pressure overloaded myocardium return to normal, as in vitro contractile function does, upon removal of the pressure overload stimulus. Three experimental groups of four cats each were studied: a group with pulmonary artery banding to create a pressure overload, a group that had been subjected to an equivalent duration of pressure overload and then had that pressure overload removed, and a group of sham‐operated controls. Seven to 10 weeks after each operative procedure, the right ventricular pressure was elevated only in the pulmonary artery‐banded group. The right ventricle/body weight ratio was significantly increased in the pressure overloaded group only. The body weight at sacrifice, the left ventricle/body weight ratio, and the right ventricular end‐diastolic pressure did not differ significantly in the three groups. The striking histological changes in the right ventricular myocardium hypertrophying in response to a pressure overload were the decrease in the volume density of cardiocytes and the increase in connective tissue in papillary muscles. These were reversed when the pressure overload was removed. This study demonstrates that when a pressure overload is removed, myocardial structure returns to normal as the function returns to normal. Given the critical importance of the proportion of cardiocytes and connective tissue components to both systolic and diastolic cardiac function, these data support the hypothesis that the abnormal proportions of these structures provide a potential morphological basis for at least some of the functional abnormalities observed in pressure overload hypertrophy of the cat right ventricle.
Subcellular distribution of the nonspecific esterase in the mouse epididymis with special reference to regional differences
Authors: Fain‐Maurel Marcelle‐Anne , Abou‐Haïla Aïuda 
Published: February 2005

AbstractThe subcellular distribution of esterases was studied in mouse epididymis by using 5‐bromo‐indoxyl‐acetate as a substrate. In all the cells of the duct, a low level of esterase activity was detected except in one of the five segments of the head–segment IV; in one of the three types of apical cells–the “prominent cells”; and in the “clear cells” scattered in the middle and distal parts. In these cells, the intensity of the reaction was high.The reaction product was consistently found in the endoplasmic reticulum and was more abundant in cells showing a high level of activity than in others. In cells with low esterase activity, the reaction was mainly restricted to this organelle. In highly active cells, the spectrum of subcellular locations was selectively enlarged and esterase was demonstrated in almost all cell compartments, including the cell membrane, nuclear envelope, mitochondria, lytic structures, and, more rarely in the Golgi apparatus or microvilli. These locations were dependent on cell type. A weak enzyme activity also appeared on mature spermatozoa.
Testicular descent in the rat and a comparison of this process in the rat with that in the pig
Authors: Wensing C. J. G. 
Published: February 2005

AbstractTesticular descent in mammals with a saclike cremaster muscle and in those with a striplike cremaster muscle differs morphologically as well as topographically. In spite of this, functional interpretations are sometimes extrapolated from species to species without defining precisely the different structures involved in this process. This has resulted in several unnecessary conflicting opinions on the mechanism of testicular descent.In this study the anatomical changes of the structures involved in the process of testicular descent in the rat are described and these data are compared with similar data on the pig. It appears that the major changes in the process in both species are (1) the outgrowth of gubernacular mesenchyme, (2) subsequent regression of this mesenchyme, and (3) development and growth of the cremaster muscle. If the structures involved are properly defined the homology of the changes in both species becomes evident.
Dividing type II cell in rabbit taste bud
Authors: Toyoshima Kuniaki , Tandler Bernard 
Published: February 2005

AbstractExamination of rabbit foliate papillae by electron microscopy revealed for the first time the existence of a dividing cell within a taste bud. The ultrastructure of this cell was in keeping with that of type II cells of the sort located in the center of taste buds. Whether this cell is capable of differentiating into other cell types is still unclear.
Development of hamster tracheal epithelium: IV. Cell proliferation and cytodifferentiation in the neonate
Authors: Otani Elaine M. , Newkirk Carnell , McDowell Elizabeth M. 
Published: February 2005

AbstractThe development of the tracheal epithelium was studied in neonatal hamsters beginning on the day of birth (day 1) and ending on day 8. Morphological changes were characterized and the proportions of cells (basal, secretory, ciliated) and mitotic indices were quantified along dorsal and ventral epithelial surfaces. Cellular proportions were stable throughout the week but the makeup of the dorsal and ventral epithelia was different. The ventral epithelium was composed of about 59% secretory cells, 39% basal cells, and 2% ciliated cells, whereas the dorsal epithelium was composed of about 52% secretory cells, 32% basal cells, and 16% ciliated cells. Mitotic indices were generally less than 1% and mitotic activity in secretory cells predominated proportionate to the ratios of secretory cells and basal cells in dorsal and ventral epithelia. During the first postnatal week changes occurred that were related to the maturation of basal cells and secretory cells. Glycogen was rapidly lost from both cell types during the first part of the week and the lateral cell membranes became increasingly complex. Apical microvilli had formed in the secretory cells by day 2 and hemidesmosomes were well developed in the basal cells. Rough and smooth endoplasmic reticulum membranes developed rapidly in the secretory cells, and mucous granules were abundant in some cells on days 4—8, especially in the ventral epithelium between the cartilage rings.The study shows that shifts in the proportions of basal, secretory, and ciliated cells do not occur in dorsal or ventral tracheal epithelium during the first postnatal week but the basal cells and secretory cells undergo rapid cytodifferentiation and functional maturation at this time.
Mechanoreceptors in the human anterior cruciate ligament
Authors: Zimny Marilyn L. , Schutte Michael , Dabezies Eugene 
Published: February 2005

AbstractThis study was undertaken to identify and quantitate mechanoreceptors in the human anterior cruciate ligament (ACL). Ligaments from six human subjects were obtained at autopsy, cut into cross‐sectional segments 1.0–1.5 cm thick, and kept oriented as to the femoral and tibial attachments. The segments were stained in bulk by using a modified gold chloride method, frozen, and sectioned on a sliding microtome at 100 μm. The sections were floated in alcoholic gelatin, mounted on slides, dehydrated, and coverslipped. Serial sections were studied with the light microscope and receptors were photographed. Cross‐sectional maps of every tenth section were made outlining the periphery of the ACL and the receptors within that section. With these maps, a computerized, morphometric analysis of the ACL was done, thus obtaining the percentage of receptors in each section and in each ACL. In addition to free nerve endings, two morphologically distinct mechanoreceptors were identified: (1) Ruffini end organs and (2) Pacinian corpuscles. Preliminary morphometric analyses show that populations of mechanoreceptors are greater at the femoral and tibial ends of the ligament and constitute approximately 2.5% of the ligament. Based on these findings the human ACL has the anatomic basis for a discriminating afferent outflow to the central nervous system.
A new approach to quantification of sertoli cells that avoids problems associated with the irregular nuclear surface
Authors: Johnson Larry 
Published: February 2005

AbstractA new approach to quantification of Sertoli cells is described. The number of Sertoli cells per testis was calculated from the number of spermatids per testis, the number of spermatids per Sertoli cell apex, and the correction for the lifespan of spermatids enumerated per testis. To evaluate this method under different physiological conditions, testes from 28 adult (4–20‐year) stallions obtained in the nonbreeding season (December–January) and from 28 adult stallions in the breeding season (June–July) were compared. Number of Sertoli cells per gram parenchyma was similar between seasons. However, the number of Sertoli cells per testis was significantly greater in the breeding season. In verification of this method, the number of spermatids per Sertoli cell apex was similar to that calculated as the ratio of spermatids to Sertoli cell in the same stallions. Likewise, absolute values similar to those of other approaches further verify the validity of this approach.
Effects of denervation and delayed amputation on forelimb regeneration in Xenopus laevis froglets
Authors: McLaughlin Danielle S. , Liversage Richard A. 
Published: February 2005

AbstractLeft forelimbs of postmetamorphic Xenopus laevis froglets were repeatedly denervated prior to and following amputation. Amputations were performed 14, 21, 28, or 42 days after the original denervation. A tissue‐regenerative response resulting in the formation of a spike‐shaped, heteromorphic outgrowth was found in the sham‐denervated and control animals, but dedifferentiation of the stump tissues was not apparent. Tissue‐regenerative outgrowths were not observed in the denervated cases; instead, dermal wound healing and stump and scar formation occurred. In both control and experimental cases, however, a periosteal proliferative response to amputation injury led to the development of a greatly thickened periosteum the length of the amputated radius‐ulna as well as a cap of cartilage at the distal end of these bones. We conclude from these results that forelimbs of postmetamorphic froglets are incapable of adjusting to a prolonged nerveless state sufficient to allow the normal tissue‐regenerative response of spike outgrowth formation.
Neuropeptide tyrosine (NPY)‐like immunoreactivity in adrenal chromaffin cells and intraadrenal nerve fibers of rats
Authors: Kuramoto Hirofumi , Kondo Hisatake , Fujita Tsuneo 
Published: February 2005

AbstractThe present peroxidase‐antiperoxidase immunohistochemical study demonstrated that approximately 50% of the total chromaffin cells of the rat adrenal medulla exhibited NPY‐like immunoreactivity. The immunoreactive material was localized in the core of the chromaffin granules as well as diffusely in the cytoplasm. By combination of immunohistochemistry with noradrenaline‐fluorescence microscopy, all NPY‐immunoreactive chromaffin cells are nonfluorescent, indicating that all NPY‐chromaffin cells co‐store adrenaline. A comparison of two consecutive sections, each of which was processed for the immunostaining with anti‐NPY and anti‐Met‐Enk‐Arg‐Gly‐Leu antisera, respectively, indicated that NPY and preproenke‐phalin A and its derivatives coexist in approximately one‐fifth of the total NPY‐immunoreactive cells.In addition to the NPY‐immunoreactive cells, a plexus of NPY‐immunoreactive nerve fibers with varicosities was found in the subcapsular regions of the adrenal gland. The nerve fibers were often associated with small blood vessels and extended into the zona glomerulosa. Single NPY‐immunoreactive fibers were sparsely distributed in the deeper regions of the cortex and in the medulla. Ganglion cells in the adrenal gland were not seen exhibiting intensely positive NPY‐like immunoreactivity. The NPY‐immunoreactive nerve fibers contained abundant small clear vesicles mixed with a few small and large granular vesicles. The immunoreactive material appeared on the granular cores as well as in the axoplasm. The NPY fibers were closely apposed to smooth muscle cells and pericytes of small blood vessels in the cortex. They were sometimes seen in close apposition to the fenestrated endothelial cells with a common basal lamina intervening. The NPY fibers also made synaptic contacts with both cortical and chromaffin cells.
Immunohistochemical localization of the MHS‐5 antigen in principal cells of human seminal vesicle epithelium
Authors: Evans Robert J. , Herr John C. 
Published: February 2005

AbstractThe location of the antigen recognized by monoclonal antibody MHS‐5 in the human reproductive tract was examined by means of enzyme‐linked immunosorbant assay (ELISA) and indirect immunohistochemistry employing the strepavidin‐biotin‐complex method. Homogenates of male reproductive tract tissues and other human organs assayed by ELISA demonstrated immunoreactivity of the MHS‐5 monoclonal antibody specifically with human seminal vesicle extracts. Varying ratios of seminal protein and monoclonal antibody ascites were tested to determine the amount of antigen necessary to completely absorb the antibody in the ELISA assay. This ratio was subsequently used to obtain the absorbed negative control for histochemical localization studies. By light microscope examination of seminal vesicle tissue in paraffin section, the MHS‐5 antigen was localized in principal cells of the seminal vesicle epithelium. Epididymal sperm, obtained from patients at orchiectomy and vasovasostomy were found to lack the MHS‐5 antigen. Following incubation with seminal protein or fluid obtained from the lumen of the human seminal vesicle, epididymal sperm reacted with the MHS‐5 antibody on ELISA. These findings indicate that the MHS‐5 antigen, a novel protein previously shown to be a unique marker for human semen, is a secretory product of the human seminal vesicle epithelium and may be reconstituted on the surface of epididymal spermatozoa.
A morphometric comparison of the nasopharyngeal airway of laboratory animals and humans
Authors: Patra A. L. , Gooya A. , Ménache M. G. 
Published: February 2005

AbstractSolid silicone rubber casts of the nasopharyngeal and laryngeal regions of a human cadaver (child, 3 years old) and a laboratory primate (baboon, 10 years old) were made, and cross‐sectional areas were measured in detail. Cross‐sectional areas of other species reported in the published literature were used for comparison. In the child's nose cast, the frontal nasal duct (frontonasal duct), which enters the anterior part of the middle meatus, and the sphenoidal recess were almost absent. The ethmoidal turbinates (superior and middle concha) and the maxillary turbinates (inferior concha) were present but were not fully developed. In the baboon nose, the different turbinates were well defined and smooth but of a less complex nature than the child's nose. Of the species compared, the baboon's upper airways had the greatest similarity to the human child's. The present study shows that for the species investigated and for those from the literature, the cross‐sectional area increases from the external nares to the maxilloturbinate region (inferior concha). There is a relatively sudden drop in cross‐sectional area about halfway through the nose. The present study suggests a functional relationship between nasal structure and cross‐sectional area across species.
Colocalization of luteinizing hormone and serotonin in secretory granules of mammalian gonadotrophs
Authors: Payette Robert F. , Gershon Michael D. , Nunez Eladio A. 
Published: February 2005

AbstractPrevious studies have demonstrated the uptake of exogenous and storage of endogenous 5‐hydroxytryptamine (5‐HT) in parenchymal cells of the anterior pituitary. The present experiments were undertaken to test the hypothesis that the endogenous 5‐HT of the anterior lobe of the pituitary is costored with β‐luteinizing hormone (β‐LH) within the same secretory granules of gonadotrophs. Electron microscope immunocytochemistry was used to detect 5‐HT and β‐LH immunoreactivities in the anterior pituitary glands of mice and bats. Primary antisera generated in different species of animals to these two antigens were localized with appropriate species‐specific secondary antisera coupled to colloidal gold particles of different sizes. This enabled 5‐HT and β‐LH immunoreactivities to be demonstrated simultaneously on ultrathin sections of fixed anterior lobe tissue mounted on electron microscope (EM) grids. In both bats and mice 5‐HT immunoreactivity, identified by immunostaining of β‐LH, was found in gonadotrophs, and in no other cell type. Within gonadotrophs about 25% of the secretory granules were labeled by antisera to both 5‐HT and β‐LH, although 100% of granules reacted with the antiserum to B‐LH. No secretory granules were found that were immunostained only by the antiserum to 5‐HT. It is concluded that endogenous 5‐HT may be a normal constituent of mammalian gonadotrophs and that it is colocalized with β‐LH in at least a subset of the secretory granules of these cells. It cannot yet be concluded that gonadotrophs synthesize 5‐HT as well as taking it up from the ambient medium. The function of 5‐HT in the pituitary remains unknown; however, the costorage of 5‐HT and β‐LH in the same secretory granules would seem to be a mechanism to ensure the simultaneous release of the two substances by exocytosis.
A microcomputer‐based graphical reconstruction technique for serial sectioned objects, with hidden line removal
Authors: Berghe W. Vanden , Aerts Peter , Claeys H. , Verraes W. 
Published: February 2005

AbstractThe presented software package fulfills the need for processing serial sections with a microcomputer configuration, enabling three‐dimensional reconstruction with hidden line removal. The language used is an interpreted BASIC‐dialect (HPL). The input is performed via an interactive program. The object can be rotated in space. The Hidden Line algorithm does not depend upon a raster technique. Points of intersection of successive contours are calculated and inserted, thus providing drawings of high resolution and quality. The handling time can be said to be short, especially when considering the capacities of the microcomputer configuration used.
Integration of clinical problems in teaching gross anatomy: Living anatomy, X‐ray anatomy, patient presentations, and films depicting clinical problems
Authors: Pabst Reinhard , Westermann Jürgen , Lippert Herbert 
Published: February 2005

AbstractIn addition to lectures and the dissection course, four supplements are described to stimulate first‐year medical students to learn gross anatomy. All topics are coordinated with the dissection course. The additional options are living anatomy, X‐ray anatomy by a roentgenologist, presentation of patients by clinicians, and films on clinical problems. This integrated curriculum of basic and applied anatomy generates a high level of student interest in gross anatomy.
Immunocytochemical study on fibrous sheath formation in mouse spermiogenesis using a monoclonal antibody
Authors: Sakai Yasuhiro , Koyama Yoh‐Ichi , Fujimoto Hirokazu , Nakamoto Tadashi , Yamashina Shohei 
Published: February 2005

AbstractOne of the components of the fibrous sheath was localized in the spermatids by the immunocytochemical method using the monoclonal antibody, K32, against the fibrous sheath of mouse mature epididymal sperm. The K32 immunoreaction was first detected in the cytoplasm of spermatids at stage 14 and appeared to increase in intensity at stage 15. At this stage, the framework structure of the fibrous sheath was formed completely in the tail, but the positive reaction in the fibrous sheath was observed only in the proximal portion of the principal piece. This change in the antigenicity of the fibrous sheath proceeded in a proximal to distal direction, which was opposite to the mode of formation of the framework structure in the fibrous sheath. Finally, the entire fibrous sheath strongly reacted to the K32 antibody at stage 16, while the reaction in the cytoplasm ceased to occur.These observations indicate that the fibrous sheath matures with immunologically detectable changes in its components following formation of the framework structure. In consideration of the retrograde progression of the cytoplasmic reaction, the fibrous sheath components may possibly be transported from the spermatid cytoplasm into the principal piece.