bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immunohistochemical localization of luteinizing hormone‐releasing hormone (LHRH) in the hypothalamus of adult female hamsters treated neonatally with monosodium glutamate or hypertonic saline
Authors: Lamperti Albert A. , Pickard Gary E. 
Published: February 2005

AbstractThe immunohistochemical localization of luteinizing hormone‐releasing hormone (LHRH) was studied in paraffin and vibratome‐sectioned tissue from adult female hamsters that were treated neonatally with monosodium glutamate (MSG) or hypertonic saline. There appeared to be a reduction in LHRH‐positive fibers in the median eminence of animals with an MSG‐induced lesion of the arcuate nucleus in paraffin‐embedded tissue. However, when unembedded tissue was cut on a vibratome, the distribution of LHRH‐positive fibers and perikarya was similar in both groups of animals. Fibers were seen coursing through the periventricular area and lateral hypo‐thalamus to the median eminence. In addition, LHRH‐positive fibers were seen in the organum vasculosum of the lamina terminalis, subfornical organ, septal and preoptic areas, fasciculus retroflexus, habenular complex, and several regions in the basal forebrain. Animals that were pretreated with colchicine had LHRH‐positive perikarya in the medial habenular nucleus, diagonal band of Broca, and the medial olfactory tract.
Embryonic length and cerebral landmarks in staged human embryos
Authors: O'Rahilly Ronan , Müller Fabiola 
Published: February 2005

AbstractThe greatest length (GL) and the crown‐rump (C‐R) length were compared in 43 staged human embryos. It was found that point C, which overlies the middle of the midbrain, was sometimes difficult to locate and that point R is not precise. These disadvantages render the C‐R measurement unsatisfactory. At 4 weeks (stage 13) the GL comes to exceed the C‐R and continues to do so until about 7 weeks (stages 17–19). The maximum difference is approximately 1.5 mm. Thereafter, the two lengths are basically equal and coincide from about stages 18 and 19 onward. In a series of 100 embryos of stages 19–23, female embryos at stages 21 and 22 were found to be shorter (by a mean of 1 mm) than male embryos, but not at stages 19, 20, and 23. The greatest length, which is independent of fixed points, is much simpler to measure than the C‐R length, and it is recommended that it be used instead. It is pointed out that Streeter had already made that substitution. The greatest length has the further advantage of being a practicable measurement from two postovulatory weeks (stage 6) throughout the remainder of the embryonic and also in the fetal period. The lower limbs are excluded from measurement.
Innervation of human bone periosteum by peptidergic nerves
Authors: Grönblad Mats , Liesi Päivi , Korkala Olli , Karaharju Erkki , Polak Julia 
Published: February 2005

AbstractNerves exhibiting substance P‐like immunoreactivity were demonstrated in the human periosteum. A network of nerves showing substance P‐like immunoreactivity was seen in the periosteum, while finer strands of immunoreactive nerve fibers were present immediately beneath the surface of the periosteum. Enkephalin‐like immunoreactivity was also studied but could not be demonstrated.Substance P has previously been suggested to be involved in the mediation of the sensation of pain. The clinically observable marked pain sensitivity of periosteal tissue might be explained by the peptidergic nerves described in this paper.
Development of agranular reticulum in Sertoli cells of the testis of the dogfish Squalus acanthias during spermatogenesis
Authors: Pudney Jeffrey , Callard Gloria V. 
Published: February 2005

AbstractBiochemical analyses of Squalus testis indicates that key enzymes involved with androgen production increase progressively from immature regions containing spermatogonia to mature regions in the late spermatid stage of maturation (Canick et al., 1983). In an effort to identify cells possessing the cytological characteristics of steroid production and to determine the structural correlates of the observed functional changes, we have carried out an electron microscopic study of Squalus testis. This report demonstrates that Sertoli cells contain a well‐developed agranular reticulum, mitochondria with tubulovesicular cristae, and numerous lipid droplets. Moreover, as germ cells mature, there is an increase in abundance of agranular reticulum in the adjacent Sertoli cells. By the time of spermatid elongation, this has reached dramatic proportions and fills the Sertoli cell as a mass of tubules. These results lead us to conclude that the Sertoli cell is responsible for secretion of the increasing amounts of androgen during the spermatogenetic cycle in Squalus.
Pulmonary type II cell lamellar body ultrastructure preserved by rapid freezing and freeze drying
Authors: McAteer James A. , Terracio Louis 
Published: February 2005

AbstractLamellar body ultrastructure was examined in cultured type II alveolar epithelial cells processed by a method of rapid freezing and freeze drying in the absence of both chemical fixation and solvent dehydration. This method of specimen preparation was chosen to optimize the retention of soluble substances within the type II cell. The use of cultured cell aggregates in which type II cells line the free surface facilitated the effectiveness of rapid freezing for the preservation of lamellar body fine structure.Lamellar bodies preserved by rapid freezing/freeze drying to optimize the in situ retention of intracellular components possess closely adherent concentric membranous lamellae. This supports the contention that the widely appreciated lamellar pattern of the pulmonary lamellar body represents the in vivo molecular organization of intracellular surfactant phospholipids.Lamellar bodies of frozen/frozen dried type II cells showed none of the often profound lipid extraction artifact produced by conventional processing. Instead they exhibited a substructure with noteworthy characteristics in common with lamellar bodies processed by resin dehydration lipid retention methods (Stratton, 1976). Importantly, the lamellae of frozen/frozen dried lamellar bodies were contiguous, with no interlamellar space, as is commonly observed in solvent‐processed (extracted) specimens. The dimensions of lamellar components in frozen/frozen dried lamellar bodies were, however, different from published values for resin‐dehydrated lipid‐retained specimens. Lamellar width and the widths of component phospholipid head and fatty acid tail regions in frozen/frozen dried lamellar bodies were approximately 35% smaller than values reported for resin‐dehydrated lamellar bodies. This difference was attributed to shrinkage of lamellar components as water was removed from the unfixed tissue during the freeze‐drying process.
Immunoelectron microscopic localization of relaxin in endometrial gland cells of the pregnant guinea pig
Authors: Pardo Rube J. , Larkin Lynn H. , Renegar Randall H. 
Published: February 2005

AbstractEndometrial gland cells in uteri from late‐pregnant guinea pigs (day 60 to parturition) resembled typical protein‐secreting cells. Extensive rough endoplasmic reticulum and well‐developed Golgi complexes were evident. The most striking features of endometrial gland cells were accumulations of large (≈ 0.5 μm in diameter), dense, membrane‐bounded granules. The granules were located in the supranuclear region of the cell and frequently occurred in close proximity to the plasma membrane adjacent to the lumen of the gland. Thin sections of endometrial gland cells treated with relaxin antiserum and either colloidal gold‐protein A or colloidal gold‐goat antirabbit IgG demonstrated that the granules contained relaxin. These studies provide additional evidence that the uterus of the guinea pig produces relaxin and support the hypothesis that uterin relaxin may play an important role in pregnancy and parturition in the guinea pig.
An electron microscopic study of two types of muscle fibers in the pharyngeal pad of crussian carp, Carassius carassius
Authors: Nakao Taisuke , Ishizawa Akimitsu , Suzuki Satoru , Saito Mitsuo 
Published: February 2005

AbstractIn the pharyngeal pad on the roof of the anterior pharynx of Carassius carassius two types of thin striated muscle fibers (1.5‐10 μm in diameter) were found. No pattern was discerned in the orientation of muscle fibers which form a loose tissue as a whole. One of them (Z fiber) is characterized by position of triads at the level of Z lines, and in the other type (A‐I fiber) they were seen at the junction of the A and I bands.Three types of intermyofibrous junction are noted between muscle fibers of the same type or between those of different types. The first type possesses ultrastructural features such as a uniform intercellular space about 90 nm which contains the basal lamina, a dense mat of the filamentous material on the sarcoplasmic aspect of the cell membrane, and a connection of myofibrils with the dense layer by thin I band filaments. The second type resembles the previous type but is distinguished from it by the lack of myofibrillar association. The third type is the nexus or gap junction. Intermyofibrous junctions of the second type are most frequently encountered (82%). Those of the first type are less frequently seen (15%), whereas the third type junctions are far less frequently seen (3%).Nerve endings at the neuromuscular junction of both types of muscle fiber contain numerous small clear vesicles suggesting their cholinergic nature.
Ultrastructural immunocytochemical localization of lysozyme in the mucociliary epithelium of the rabbit endocervix in different hormonal states
Authors: Nicosia Santo V. , Sowinski Janice M. , Chilton Beverly S. , Streibel Ellen J. 
Published: February 2005

AbstractThe distribution of lysozyme in the endocervix of estrous, pseudopregnant, and ovariectomized rabbits was studied using two different immunocytochemical techniques—the unlabeled antibody enzyme method of Sternberger et al. (1970) and the peroxidase‐labeled antibody method of Taylor and Burns (1974). With both procedures, a fine immunostaining precipitate was seen over the entire area of basal mucous granules, while immunodeposits were coarser and mostly located in the outer zone of central and apical granules. A nonspecific staining was noted when tissues were reacted with peroxidase‐antiperoxidase complex alone. This troublesome artifact was abolished by preincubating tissues with human IgA. This step did not affect the specific immunostaining for lysozyme yet nonspecific staining was absent from specificity and method controls carried out for both immunocytochemical procedures. The presence of high levels of lysozyme in the endocervical epithelium of estrous rabbits was also confirmed in enzymatically isolated endocervical epithelia using the lysoplate method of Osserman and Lawlor (1966). Mucous granules and immunostainable intracellular lysozyme were abundant during estrus, decreased during early pseudopregnancy, and were absent after longterm ovariectomy. However, they were restored by the administration of estradiol (5 μ/12 hours/10 days) to ovariectomized animals. These data indicate a common hormonal regulation and secretory mechanism for endocervical mucous glycoproteins and lysozyme.
An ultrastructural morphometric comparison of the peripheral with the hilar air‐blood barrier of dog lung
Authors: Berendsen Peter B. , Ritter Arthur B. , DeFouw David O. 
Published: February 2005

AbstractExcised and isolated perfused lungs are frequently used as models for studies of fluid flow and membrane transport.Regional variations of the air and blood vascular compartments of the lung have been recognized to result from gravitational effects. This ultrastructural morphometric study considered the components of the air‐blood barriers of the peripheral and hilar regions of excised dog lungs. The lungs of three mongrel dogs were fixed by endotracheal instillation of glutaraldehyde and immersion in fixative. Stratified random sampling, point counting volumetry, and line intercept counts were used to determine the thicknesses of the air‐blood barrier and the epithelial, interstitial, and endothelial compartments. Point counting volumetry also established the volume density of the alveolar spaces. The morphometric values for structures within the periphery were statistically compared to those within the hilar region by Student's t‐test. Endotracheal and immersion fixation as used in this study, combined with stratified random sampling, equalized regional differences in the alveolar lumen volume and airblood barrier thickness. With these conditions no significant differences in the volume densities of the epithelial and endothelial cells and the interstitium of the air‐blood barrier were identified when those of the hilum were compared to those of the periphery.
Effects of two glycosaminoglycans on seeding of cardiac cushion tissue cells into a collagen‐lattice culture system
Authors: Bernanke David H. , Markwald Roger R. 
Published: February 2005

AbstractA collagen‐lattice culture model of developing heart valves was utilized to test two glycosaminoglycans, normally found in the cardiac jelly matrix of developing heart valve primordia, for their effects on the capability of mesenchymal derivatives of cardiac cushion endothelial cells to enter the substrate from the surface. Treatment with hyaluronate increased the rate of cell seeding to 2.04 times that of untreated control cultures and 1.82 times that of chondroitin sulfate‐treated cultures. Scanning electron microscopic studies suggested that the increased rate was due to an enhanced disruption of intercellular junctions, influenced by hyaluronate, permitting disengagement of cells from the surface population and migration as mesenchymal cells into the collagen matrix. The results of this study correlate well with the presence of high hyaluronate concentrations in the cardiac jelly matrix beneath the cushion endothelium at periods of active seeding of cushion tissue cells.
Histochemical localization of ouabain‐sensitive, K+‐dependent p‐nitrophenylphosphatase (Na+‐K+‐ATPase) activity in the submandibular gland of the mouse: Effect of androgen, thyroid hormone, or postnatal age
Authors: Sims‐Sampson Graciella , Gresik Edward W. , Barka Tibor 
Published: February 2005

AbstractOuabain‐sensitive Na+‐K+‐ATPase activity was localized histochemically in the submandibular gland of the mouse under various conditions using p‐nitrophenylphosphate as substrate at pH 9. In untreated adult males and females, intense staining was seen in the basally striated portions of the epithelial cells lining the excretory and striated ducts. The region of the lateral cell membranes, but not of the apical plasmalemma, also stained. In granular convoluted tubules (GCTs), strong staining was seen only in a narrow band of the basalmost region of the cells; in males this stained region was thinner than in females, and frequently was absent. The baso‐lateral margins of acinar and intercalated duct cells gave a very weak reaction.In untreated males, or in females that were treated with dihydrotestosterone, overall staining for the enzyme was always less than in untreated females, due to the diminished reactivity of androgen‐stimulated GCT cells and the decreased number of striated ducts. However, in females treated with triiodothyronine, enhanced activity of Na+‐K+‐ATPase was indicated by stronger staining in all cell types, including the hypertrophied GCT cells. Na+‐K+‐ATPase activity was undetected in the submandibular glands at birth, but moderate staining was seen in the larger excretory and striated ducts by 5 days of age. From 10 days of age onward, intense staining was seen in the excretory and striated portions of the ramifying duct system. Developing GCT cells could not be distinguished from their precursor cells in the striated ducts until 25 days of age. These data indicate that the salt‐handling capacity of the submandibular gland of the mouse varies with both endocrine status and age.
Morphology of presumptive slowly adapting receptors in dog trachea
Authors: Krauhs Jane M. 
Published: February 2005

AbstractThe three‐dimensional branching pattern and ultrastructure of afferent myelinated fibers and their terminals located in the trachealis muscle of the dog are described. The afferent endings are believed to be those of the slowly adapting stretch receptors of the trachea. They have structural features typical of mechanoreceptors: distal to the loss of myelin, their shape becomes more irregular and the cytoplasm is filled with mitochondria, glycogen, and osmiophilic bodies. In some places the cell membrane is attached directly to basal lamina without interposition of a Schwann cell. A bundle of unmyelinated fibers accompanies each myelinated fiber and continues for an undetermined distance beyond (luminal to) terminations of the myelinated fiber. The unmyelinated fibers contain many round, clear vesicles and a few dense‐cored vesicles and are also attached directly to basal lamina in places. Three‐dimensional reconstruction of three receptors revealed three quite different branching patterns, but all included apparent rings as part of more or less contorted terminal regions (some neurons apparently having more than one terminal region). No obvious structural basis for the activation of receptors by transverse but not longitudinal stretch was found.
Development of morphologic heterogeneity of hepatocyte mitochondria in the mouse
Authors: Kanamura Shinsuke , Kanai Kazuo , Oka Motoko , Watanabe Jun , Asada‐Kubota Mari 
Published: February 2005

AbstractThe ultrastructure of mitochondria in perioportal and perihepatic hepatocytes from newborn, 5‐, 10‐, and 20‐day‐old, and adult male ddY mice was analyzed by quantitative electron microscopy. In newborn and 5‐ and 10‐day‐old animals, the axial ratio (length per diameter), surface to volume ratio (area of the outer membrane per unit mitochondrial volume), and volume density were not significantly different between periportal and periphepatic cells. In 20‐day‐old and adult animals, the surface to volume ratio was greater in perihepatic cells than periportal cells, and the volume density was greater in periportal cells than perihepatic cells. The axial ratio became greater in perihepatic cells than periportal cells in adult animals. However, there were no differences in the surface density of the outer membrane, and of the inner membrane and cristae between the cells of both zones in all age groups examined. When the data were expressed as volume and area per cell, the patterns of subacinar distribution and age‐related changes differed from the patterns seen in the volume and surface density data mainly in adult animals. This difference was generally caused by the marked increase in hepatocyte volume between 20 days of age and adulthood, especially in perihepatic cells.The results show that differences between mitochondria in periportal cells and those in perihepatic cells in the shape (the axial and surface to volume ratios), volume density, and area of the outer membrane per cell, evident in adult animals, are not present in newborn animals but arise during postnatal development.
The effects of simulated increases in body weight for 30 and 60 days on bone robusticity of limb bones in rats
Authors: Simon Mark R. , Holmes Kenneth R. , Olsen Aart M. 
Published: February 2005

AbstractThe purpose of this study was to subject groups of weanling male rats each to a specific 10% simulated increase in body weight, ranging from 1.1G–2.0G, using constant centrifugation. (In this paper, “G” is the acceleration due to gravity.) After 30 and 60 days, rats were killed and perfused with 10% buffered neutral formalin (B.N.F.). The humerus, radius, ulna, femur, and tibia were removed, cleared of all soft tissues, weighed, and the total length measured. Bone robusticity was calculated using the ponderal index: bone length/\documentclass{article}\pagestyle{empty}\begin{document}$ \sqrt[3]{{{\rm bone}\,{\rm weight}}} $\end{document}. Tukey's Multiple Range Test was used. The data suggest that the specific limb bone, G, and duration of centrifugation are each factors in the response of limb bones to simulated increases in body weight.
The effects of simulated increases in body weight from birth on bone robusticity of limb bones of rats
Authors: Simon Mark R. , Holmes Kenneth R. , Olsen Aart M. 
Published: February 2005

AbstractGroups of newborn rats were each subjected to a specific 10% simulated increase in body weight, ranging from 1.1G to 2.0G, to study changes in bone robusticity. (In this paper, “G” is the acceleration due to gravity.) Constant centrifugation was used. At 90 days of age, the rats were killed and the humerus, radius, ulna, femur, and tibia were removed, weighed, and measured. Bone robusticity was calculated using the ponderal index: bone length/\documentclass{article}\pagestyle{empty}\begin{document}$ \sqrt[3]{{{\rm bone}\,{\rm weight}}} $\end{document}. Tukey's Multiple Range Test was used. The data suggest that, for both males and females, bone robusticity is increased with simulated increases in body weight.
Prevention by pinealectomy of short‐photoperiod‐induced ultrastructural changes in the hamster harderian gland
Authors: Diioria Dennis P. , Nadakavukaren Mathew J. 
Published: February 2005

AbstractHarderian gland ultrastructure was examined at biweeky intervals for 16 weeks after either pinealectomy or sham‐operation of male and female hamsters kept in 1L:23D and 14L:10D photoperiods. Female characteristics such as membrane formations and extensive smooth endoplasmic reticulum appeared in the males kept under short photoperiod conditions. Similarly, male characteristics such as the tubular clusters appeared in the glands of females kept in the short photoperiod. When male and female hamsters were pinealectomized and exposed to the short photoperiod, the glands in each sex retained the characteristics typical of that sex. Atrophy of the testes and uteri was also observed in the sham‐operated hamsters maintained under short photoperiods, but not in the pinealectomized animals. The changes observed in the Harderian glands and reproductive organs of hamsters kept in the short photoperiod were not observed in the hamsters maintained in the long photoperiod. The photoperiod‐induced ultrastructural changes in the hamster Harderian glands are most likely due to changes in hormonal levels brought about by the regression of reproductive organs and can be prevented by pinealectomy.
Effects of progressive hyperglycemia on ovarian structure and function in the spontaneously diabetic Chinese hamster
Authors: Garris David R. 
Published: February 2005

AbstractThe effect of the progressive hyperglycemic condition on ovarian follicular maturation was studied in control, moderate (160–350 mg/d1 blood glucose), and overt (≥ 350 mg/d1 blood glucose), spontaneously diabetic Chinese hamsters. Match‐paired (age, sex, and weight) control and diabetic animals were sacrificed at specific intervals during the development of the diabetic condition; the ovaries were collected and morphometrically analyzed for changes in ovarian follicular growth relative to blood glucose levels. Follicles were classified according to size, number, and condition. The total number of primary (100–200 μm diameter) and secondary (200–350 μm diameter) follicles was reduced in both moderate and overt diabetic females as compared with controls. The percentage of viable (i.e., nonatretic) follicles was greatly reduced in the secondary follicle class of overt diabetic animals as compared with controls. No significant differences were observed in the numbers of viable tertiary (i.e., ≥ 350 μm diameter) follicles in any of the diabetic animals as compared with controls. The percentage of atretic, secondary follicles was greatly increased in the overt diabetic group as compared with controls. These data indicate that the progressive hyperglycemia associated with diabetes in the Chinese hamster induces a severe depression of normal follicular recruitment resulting in an impaired reproductive performance in this species.