bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interactions between rat epididymal epithelium and spermatozoa
Authors: Fornés Miguel W. , De Rosas Juan C. 
Published: May 2005

AbstractWe studied in the rat epididymis the presence of membrane‐bounded vesicles in the stereociliar areas of the epithelial cells. The intimate contact between principal cell stereocilia and luminal spermatozoa was also explored.The epididymidis of adult male albino rats were fixed with Mollenhauer's fixative via the thoracic aorta; they were removed and the caput and the cauda were separated and fixed for 4 additional hours at 4°C. After fixation, the samples were processed with routine techniques for transmission and scanning electron microscopy.The study showed membrane‐bounded vesicles in the lumen of the caput and cauda epididymidis. They are present between stereocilia, in the most peripheral regions of the epididymal lumen, and in a stereocilia‐free zone in the apical plasma membrane of the principal cells. The smaller vesicles are located near the apical surface of the latter, and the larger ones are located near the tips of the stereocilia. Their contents are electron lucent in some images and electron dense in others. In several thin sections some of the vesicles are observed to have a stalk. This suggests that the possible mode of production may be an exocytotic process. Some membrane‐bounded vesicles were found to be in contact with the head or the tail of maturating spermatozoa.Moreover, an intimate contact was found to exist in the epididymidis between the plasma membranes of the spermatozoa and the stereocilia.These observations seem to suggest two possible mechanisms for sperm‐epididymal cell relations: 1) release of a secretion product via the membrane‐bounded vesicles and 2) direct contact between stereocilia and spermatozoa.
Sectional anatomy of the pelvis in the male rat with ultrasound correlations
Authors: Suzuki Takanori , Takezawa Yutaka , Tamura Yoshimi , Mashimo Tooru , Imai Kyoichi , Yamanaka Hidetoshi , Suzuki Keiji 
Published: May 2005

AbstractTen‐week‐old male Wistar rats were used for sectional anatomy and ultrasonic diagnosis of the pelvis. The prostate and the urinary bladder were identified easily on longitudinal section by ultrasound examination. The prostate (ventral, lateral, and dorsal lobes) was located in the midline of the pelvis cavity on transverse sections and the caudal side of the urinary bladder on longitudinal sections. The urinary bladder was positioned at the cranial side of the prostate on longitudinal sections and in the midline of the pelvis cavity on transverse sections. The seminal vesicles were located at right and left positions of the urinary bladder.Ultrasonic diagnosis was estimated to be useful for experimental studies and we hope that ultrasound techniques may reduce the number of rats used for the treatment of prostate and urinary bladder cancers.
Inflated, dried whole lung specimens
Authors: Oldham Michael J. , Phalen Robert F. 
Published: May 2005

AbstractA method is described for preparing fully‐inflated whole lung specimens that are suitable for instruction or research purposes. Undamaged lungs are removed from the body and then tracheally cannulated and lavaged with tap water more than 250 times. The treatment also includes rinsing blood from vessels with water. A final filling of the lung with alcohol is optional. The multiply rinsed lung is drained and inflated to 30 cm of H2O pressure with dehumidified air and held at that pressure until the tissue is completely dry. The resulting specimens are light in color and appear to be permanent if stored properly.
Quantitative morphology of the nervous system: Expanding horizons
Authors: Bolender R. P. , Charleston J. , Mottet K. , McCabe J. T. 
Published: May 2005

AbstractIn this review, we show how some of the recent developments in quantitative morphology (QM) are creating exciting new opportunities for studying the structure of the nervous system. We begin with a brief overview of QM, focusing on the problems neurobiologists are likely to encounter when collecting and interpreting data from tissue sections. Many of these problems, which range from selecting a sampling method to learning the latest methods, are being solved by creating a new generation of research tools. We describe several of these new tools and show how they can be used to assemble new quantitative methods for in situ hybridization, immunocytochemistry, and camera lucida drawings. The review includes examples of how QM is being used to study the brain and concludes with a brief discussion of diagnostic pathology and its need for new quantitative approaches.
A morphometric and computer‐assisted three‐dimensional reconstruction study of neural tube formation in chick embryos
Authors: Nagele Robert G. , Bush Kevin T. , Lynch Francis J. , Lee Hsin‐Yi 
Published: May 2005

AbstractThe origin of the driving forces for neural tube formation remains uncertain but is currently thought to involve the participation of microfilament bundles situated in the apical ends of neuroepithelial cells. In the work presented here, we show how morphometric measurements that map local variations in the apical geometry of neuroepithelial cells (especially apical constriction) can provide information on the distribution of motive forces within the neuroepithelium during neural tube formation. When used in combination with computer‐assisted, three‐dimensional reconstruction, it becomes possible to analyze the morphometric data from a dynamic, three‐dimensional perspective. As an example application of this method, we have used morphometry to evaluate the effects of ionomycin on the developing neuroepithelium. Treatment of early (stages 6‐8) chick embryos with 5 μM ionomycin was found to cause rapid bending of the neuroepithelium within 1 min of exposure and a dramatic acceleration of the normal sequence of neural tube formation. Electron microscopy and morphometry revealed that this acceleration was coincident with a marked increase in the local degree of apical constriction of neuroepithelial cells, presumably a consequence of enhanced contractile activity of apical microfilament bundles. This work shows that transient elevation of free calcium levels can accelerate the usualal sequential phases of NT formation. The rapidity of the response (hours of normal development reduced to minutes), increased prominence of apical microfilament bundles, and the enhanced degree of apical constriction strongly support a direct causal role for apical microfilament bundles and apical constriction of neuroepithelial cells in bending of the neuroepithelium.
Hypothalamic dopaminergic neurons in transgenic dwarf mice: Histofluorescence, immunocytochemical, and in situ hybridization studies
Authors: Phelps Carol J. , Carlson Susan , Hurley David L. 
Published: May 2005

AbstractSpontaneous dwarf mice, in which both growth hormone (GH) and prolactin (PRL) are undetectable, are severely deficient in the PRL‐inhibiting catecholamine dopamine (DA), as well as its synthetic enzyme, tyrosine hydroxy‐lase (TH), in the basal hypothalamus (Phelps et al., Cell Tissue Res., 240:19–25, 1985; Phelps, Brain Res., 416:354–358, 1987). In contrast, transgenically constructed dwarf mice (Behringer et al., Genes Dev., 2:453–461, 1988) show complete ablation of pituitary GH cells, but PRL cells are retained at a level of ≈ 10% of normal. In order to determine the feedback effect of this reduced, rather than absent, PRL on hypothalamic DA neurons, brains of transgenic dwarf mice were examined for catecholamine transmitters by histofluorescence, for the synthetic enzyme TH by immunocytochemistry, and for TH mRNA expression by in situ hybridization. DA histofluorescence in transgenic dwarfs was comparable to that of normal littermate mice in nonpituitary regulating areas (perikarya of zona incerta [A13] of hypothalamus and in midbrain substantia nigra areas [A9]). Arcuate nucleus (A12) DA neurons that inhibit PRL secretion, however, showed dim to absent fluorescence in perikarya and in external median eminence terminals in dwarfs. There were reduced (P < 0.05) numbers of A12 TH‐immunoreactive neurons in transgenic dwarfs, to approximately 60% of those in normal mice. In contrast, TH‐positive neurons in other hypothalamic areas (A13, A14) had average populations equivalent to those in normal mice. Quantification of TH mRNA abundance by in situ hybridization using both image analysis of hybridization over the arcuate nucleus, and grain counts per individual A12 cell in this nucleus, indicated that relative mRNA levels were the same in normal and transgenic dwarfs. The observations indicate that reduction in pituitary PRL is accompanied by defective expression in hypothalamic tuberoinfundibular neurons, which is severe at the DA neurotransmitter level, significant regarding observable TH immunoreactivity, and undetectable with regard to TH mRNA expression. Collectively, the findings suggest that posttranscriptional processes are involved with the mediation of PRL feedback upon hypothalamic neurons. Technically and quantitatively, the report presents the feasibility of simultaneous evaluation of transmitter histofluorescence, synthetic enzyme immunocytochemistry, and mRNA expression in individual animals.
Application of confocal laser scanning microscopy to the deep pineal gland and other neural tissues
Authors: Welsh Marcia G. , Ding Jian Ming , Buggy James , Terracio Louis 
Published: May 2005

AbstractThe study of the deep pineal gland of the Mongolian gerbil and other neuronal tissue from the rat by means of confocal laser scanning microscopy (CLSM) is described. Opical serial sectioning was performed on thick (100–200 μm) sections of the deep pineal gland of the Mongolian gerbil stained immunohis‐tochemically using antisera to S‐antigen and tyrosine hydroxylase (TH). Both dual‐stained and single‐stained material was examined using the fluorochromes fluorescein isothiocyanate (FITC) and Texas Red. High resolution images were obtained showing that pinealocytes have 1–3 processes that extend primarily to other pinealocytes or presumptive pinealocytes. Pinealocytes are located within the deep pineal gland as well as adjacent to the posterior aspect of the medial habenular nuclei. Pinealocyte processes were not seen extending into the habenular nuclei, but rather ended within the deep pineal gland a significant distance from their perikarya. The TH‐immunopositive fibers were distributed throughout the deep pineal gland, often forming “baskets” of fibers around pinealocytes rather than being associated primarily with blood vessels. Other uses of the confocal microscope are demonstrated on rat neural tissue reacted with peroxidase/diaminobenzidine (DAB) immunohistochemistry and FITC fluorescence immunohistochemistry (paraventricular nucleus) as well as Golgi‐stained neuronal tissue (cerebral cortex). The HRP/DAB and Golgi‐stained images were visualized using the reflected image mode of the confocal system. A summary of the advantages of CLSM include the following: (1) the optical sectioning capabilities allow for true three‐dimensional imaging thus aiding in the determination of the three‐dimensional structure of a cell plus cell‐cell associations, (2) intact tissue as well as thick sections can be used without mechanical sectioning artifacts, (3) higher resolution can be obtained due to elimination of out‐of‐focus fluorescence, (4) CLSM requires significantly less time than other three‐dimensional reconstruction techniques, and (5) once computerized, the data can be analyzed or processed in a variety of ways.
Unbiased stereological estimation of the total number of neurons in the subdivisions of the rat hippocampus using the optical fractionator
Authors: West M. J. , Slomianka L. , Gundersen H. J. G. 
Published: May 2005

AbstractA stereological method for obtaining estimates of the total number of neurons in five major subdivisions of the rat hippocampus is described. The new method, the optical fractionator, combines two recent developments in stereology: a three‐dimensional probe for counting neuronal nuclei, the optical disector, and a systematic uniform sampling scheme, the fractionator. The optical disector results in unbiased estimates of neuron number, i.e., estimates that are free of assumptions about neuron size and shape, are unaffected by lost caps and over‐projection, and approach the true number of neurons in an unlimited manner as the number of samples is increased. The fractionator involves sampling a known fraction of a structural component. In the case of neuron number, a zero dimensional quantity, it provides estimates that are unaffected by shrinkage before, during, and after processing of the tissue. Because the fractionator involves systematic sampling, it also results in highly efficient estimates. Typically only 100–200 neurons must be counted in an animal to obtain a precision that is compatible with experimental studies. The methodology is compared with those used in earlier works involving estimates of neuron number in the rat hippocampus and a number of new stereological methods that have particular relevance to the quantitative study of the structure of the nervous system are briefly described in an appendix.
Ipsilaterally projecting rubrospinal neurons in adult and developing opossums
Authors: Xu Xiao Ming , Martin G. F. 
Published: May 2005

AbstractWe have combined injections of Fast Blue with lesions of the rubrospinal tract rostral and contralateral to them to determine if an ipsilateral rubrospinal projection exists in adult or developing opossums and, if so, to characterize the neurons giving rise to it. Although the results indicate that some rubral neurons project ipsilaterally, they are very few in number. Using quantitative and image analysis techniques, we have shown that 0.6% of the rubral neurons that project to the lumbar cord in adult opossums do so ipsilaterally and that such neurons are comparable in location and size to those that project contralaterally. Similar results were obtained in developing opossums. Our results are discussed in light of rubrospinal development and ongoing experiments related to rubrospinal plasticity.
Heterogeneous distribution of dopamine D2 receptor mRNA in the rat striatum: A quantitative analysis with in situ hybridization histochemistry
Authors: Szele Francis G. , Artymyshyn Roman , Molinoff Perry B. , Chesselet Marie‐Francoise 
Published: May 2005

AbstractDopamine D2 receptor mRNAs have recently been cloned and their gross distribution in the central nervous system described. Quantitative in situ hybridization histochemistry with a cRNA probe complementary to the mRNAs encoding approximately 70% of the third intracellular loop of the rat D2 receptor was performed on sections of rat brain to determine whether differences previously observed in the density of ligand binding sites in subregions of the striatum were related to differences in mRNA levels. Film autoradiographic analysis demonstrated 30% more hybridization signal in the lateral compared to the medial caudate‐putamen, a distribution parallel to that of binding of ligands specific for the D2 receptor. Inspection at the cellular level using emulsion autoradiography also indicated a differential distribution of the D2 receptor mRNA. Fewer positively labelled cells, as well as fewer silver grains per cell, were seen in the medial compared to the lateral half of the striatum. This suggests that the gradient seen in autoradiographic studies of the distribution of D2 receptors is related both to regional differences in D2 mRNA levels and to the density of cells expressing the receptor. In addition, the distribution of cells expressing D2 receptor mRNA in the extrastriosomal matrix was compared to that in striosomes identified by the presence of a high density of 3H‐naloxone binding sites. Labelled cells were mainly found in the matrix (3H‐naloxone binding‐poor) but were also seen in striosomes (3H‐naloxone binding‐rich). The results suggest that differences in levels of D2 binding sites in subregions of the striatum are related to differences in the level of expression of this receptor in intrinsic striatal neurons, suggesting differential regulation of dopamine D2 receptor gene expression in topographically distinct striatal neurons.
Periarterial lymphoid sheath in the rat spleen: A light, transmission, and scanning electron microscopic study
Authors: Sasou Shunichi , Sugai Tamotsu 
Published: May 2005

AbstractThe periarterial lymphoid sheath (PALS) in the rat spleen was studied by light, transmission, and scanning electron microscopy. The PALS was divided into three regions: the central region, peripheral region, and marginal zone bridging channel. In the central region, lymphocytes were easily washed away by perfusion. Large spaces were found between flat reticular cells or in large meshworks of stellate reticular cells; these may be deep lymphatic vessels. True lymphatic vessels were found in the central region near the hilus. In the marginal zone bridging channel, flat reticular cells surrounded the central artery in a circumferential pattern and formed channel‐like spaces between the flat reticular cells. These spaces were connected with the meshwork of the red pulp reticular cells and may be a route for lymphocytes between the deep lymphatic vessels and the red pulp. In the peripheral region of the PALS, it was usually difficult to wash away free cells by perfusion, and free cells were found among the reticular cells. In places in the peripheral region, however, free cells were washed away. It is suggested that the lymph flow may start from the region surrounding the PALS, and that the peripheral region of the PALS may also be another route for lymphocyte migration.
Three‐dimensional structure of cytidine monophosphatase reactive trans‐Golgi elements in spinal ganglion cells of the rat
Authors: Rambourg Alain , Clermont Yves 
Published: May 2005

AbstractIn order to analyse, at the electron microscope level, the three‐dimensional configuration of the trans compartment of the Golgi apparatus rat dorsal root ganglia were treated to demonstrate cytidine monophosphatase (CMPase) activity. The localization of enzymatic activity in the Golgi apparatus varied according to cell types. In type A and C cell, CMPase was exclusively located in the transmost sacculotubular element, whereas in type B cells all the saccules of the stacks forming the Golgi ribbon and the trans‐Golgi networks were impregnated. Numerous dense bodies seen at proximity were also CMPase positive. In 3 μm thick sections of type A cells examined at low magnification, the impregnated element was scattered throughout the cytoplasm and never formed a continuous structure. In type B cells, the strongly reactive trans‐Golgi networks did not follow the entire length of the impregnated Golgi ribbon but were preferentially located in the concavity of its arched portions. At higher magnification and in all cell types some tubular portions of the trans‐Golgi networks took the apperance of spheroidal cage‐like structures, the CMPase positive anastomotic tubules forming the bars of the cage. Anastomotic tubules separated from the trans‐Golgi networks formed fenestrated spheres, while nearby CMPase‐reactive dense bodies exhibited a paler hilus. These observations were taken to indicate that in ganglion cells, some CMPase positive dense bodies, presumably lysosomes, formed by fragmentation of the trans‐Golgi networks.
Influence of retinol on human chondrocytes in agarose culture
Authors: Aulthouse Amy Lynn , Carubelli Cecilia M. , Dow Tod M. , Ziegelmayer Christine , Beck Michael 
Published: May 2005

AbstractVitamin A and its congeners, collectively called retinoids, are known to have teratogenic potential and have induced craniofacial and limb malformations in numerous animal species. More importantly, retinoids are recognized as teratogenic to fetuses of pregnant women who have taken such preparations for dermatologic disorders. Information gathered from the study of animal models suggests that retinoids interfere with cartilage differentiation. If chondrogenesis in limb development is disturbed it may contribute to limb reductions and malformations. In vitro studies using various animal systems have shown that cartilage matrix macromolecules are altered to resemble those secreted by mesenchymal cells. The response of human chondrocytes to retinoids in vitro is not known. Culture of human chondrocytes in agarose maintains the cartilage phenotype and therefore serves as a model system to evaluate the influence of retinoids directly on human chondrogenesis. The studies presented in this paper were done to determine if the expression of specific matrix macromolecules of human chondrocytes in agarose culture is altered by retinol treatment. Immunocytochemistry demonstrated enhanced labeling of type I collagen while type II collagen labeling was reduced in cultures treated with retinol. In addition, morphometric analyses indicated a decrease in the size and number of chondrogenic clusters and that individual cells synthesized less alcian blue matrix when compared to parallel control cultures. The size of the proteoglycan monomers, glycosaminoglycan side chains as well as the disaccharide composition were not affected. However, there was a reduction in the quantity of proteoglycan monomers produced.
Localization of the Ca2+‐dependent proteinases and their inhibitor in normal, fasted, and denervated rat skeletal muscle
Authors: Kumamoto Toshihide , Kleese William C. , Cong Jinyang , Goll Darrel E. , Pierce Paul R. , Allen Ronald E. 
Published: May 2005

AbstractImmunofluorescence and immunogold localization studies show that the two Ca2+‐dependent proteinases (μ‐calpain for the micromolar Ca2+‐requiring proteinase and m‐calpain for the millimolar Ca2+‐requiring proteinase) and their protein inhibitor (calpastatin) are located exclusively intracellularly in normal rat soleus muscle. Quantitative immunogold studies indicate that binding of antibodies to both calpains and to calpastatin is approximately two times greater at the Z‐disk of myofibrils than it is at the I‐band or A‐band regions. Mitochondria and nuclei in muscle cells contain both calpains and calpastatin at concentrations approximately one‐tenth and one‐fifth, respectively, of the concentration at the Z‐disk, as estimated by antibody binding. Very little calpain or calpastatin was seen in the cytoplasmic intermyofibrillar spaces, and most of the calpain and calpastatin in muscle cells is associated with intracellular structures. Immunofluorescence results suggest that concentration of m‐calpain but not μ‐calpain or calpastatin is, in some instances, slightly higher near the intracellular surface of the plasma membrane than elsewhere in the muscle cell. Most m‐calpain, however, is distributed throughout the interior of mature rat skeletal muscle cells. Denervation, or fasting and refeeding increases the concentration of the calpains and calpastatin in the muscle cell but does not change their distribution. Some μ‐and m‐calpain and calpastatin is found extracellularly in denervated soleus muscle or soleus muscle from fasting rats, but the extracellular calparns and calpastatin seem to originate from “leakage” of these proteins out of the cell because serum creatine kinase levels are much higher than normal in denervated or fasting rats.