bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cytoplasmic granules in luteal cells of pregnant and non‐pregnant guinea pigs. A cytochemical study
Authors: Paavola Laurie G. , Boyd Charles O. 
Published: February 2005

AbstractSecretory granules, which are released by exocytosis and are speculated to contain progesterone, have been described in luteal cells of sheep and other large domestic animals. These granules are small and densely staining. Gemmell and Stacy ('79) suggested that luteal cells of guinea pigs also contain secretory granules, although they could not document exocytosis of granule content at the fine structural level. For the present study, quantitative methods were used to reexamine the possibility that luteal cells of guinea pigs possess secretory granules. Ovaries of guinea pigs were fixed in situ by vascular perfusion at the time of maximum progesterone secretion, when such granules would be most abundant, as well as at other stages. Two types of granules that might be confused with secretory granules are microperoxisomes and lysosomes. Therefore, slices of perfusion‐fixed corpora lutea were incubated for the fine structural localization of a peroximomal enzyme, catalase, or for the lysosomal enzymes, acid phosphatase (ACPase) and arylsulfatase. Other tissue was prepared for conventional electron microscopy. Granule types were classified on the basis of size, morphology, and enzyme content. Quantitation of granule types was carried out on both cytochemically reacted and conventionally prepared luteal tissue. More than 5500 microperoxisomes, 2800 lysosomes, and 1100 multivesicular bodies (MVBs) were tabulated. The results indicate that luteal cells of guinea pigs have three main types of granules: (1) Microperoxisomes, about 0.2μm in diameter and containing catalase; (2) lysosomes, about 0.5μm in diameter and positive for ACPase and arylsulfatase; and (3) MVBs, about 0.4μm in diameter and containing small vesicles. At the time of peak steroid secretion during pregnancy and the estrous cycle, the granule population in luteal cells of guinea pigs consists of 73–80% microperoxisomes, 13–17% lysosomes, and 7–l9% MVBs. These proportions are similar in tissue reacted for cytochemistry and tissue prepared by conventional means. Greater than 99% of the small 0.2–0.3μm diameter granules in guinea pig luteal cells are catalase reactive. This finding eliminates from further consideration most of the prime candidates for secretory granules in these cells. Finally, neither a sequential appearance of granules nor exocytosis of secretory product was detected. Our data thus argue against the suggestion that luteal cells of guinea pigs have secretory granules of the type observed in corpora lutea of large domestic animals.
The effect of buffer molarity on axonal exposure and axoaxonal apposition in the rat molar pulp
Authors: Holland G. R. 
Published: February 2005

AbstractAxons in the rat molar pulp have been examined morphometrically to determine axonal size and the degree of axonal exposure and axoaxonal apposition in tissue fixed by perfusion using 2% glutaraldehyde in cacodylate buffers ranging in molarity from 0.025 M to 0.4 M. Between 31.2% and 45.0% of the axons were incompletely ensheathed. This proportion of axons exposed was linearly related to the buffer molarity (P < 0.05) and was approximately double that found in more central axons. Between 32.3% and 45.0% of the axons were in contact with other axons. This proportion was not linearly related to buffer molarity but was at least ten times higher than that observed in more centrally positioned nerve fibers in the inferior alveolar nerves. Increasing buffer molarity reduced the size of the axons, a relationship not found in the more central axons. It is suggested that axonal exposure and axoaxonal apposition are constant, significant features of pulpal nerve fibers that may be related to the onset and spread of nociceptive activity. The permeability properties of pulpal axons may differ from those of more centrally placed axons.
Membrane specialization in the rat epididymis. II. The clear cell
Authors: Brown Dennis , Montesano Roberto 
Published: February 2005

AbstractThe clear cell is a characteristic cell type, particularly frequent in the epididymal tail, which has many small vesicles and larger vacuoles in the apical cytoplasm. In freeze‐fracture replicas of adult rat epididymis, we found that the limiting membrane (P‐face) of these vesicles and vacuoles, as well as the luminal plasma membrane (but not the basolateral membrane) contain a high density of prominent intramembrane particles. In contrast, the apical vesicles of the most common cell type, the principal cell, have a much lower density of particles, which are also of smaller size. The unique organization of these membranes in clear cells suggests that this cell type has a special role in epididymal function.
Studies on zonation in the epididymis of the guinea pig. I. Ultrastructural and biochemical analysis of the zone rich in large lipid droplets (zone II)
Authors: Hoffer Anita P. , Karnovsky Manfred L. 
Published: February 2005

AbstractIn the epididymis of the guinea pig, zone II exhibits striking histological features that distinguish it readily from the other six regions of the epididymis. At the light microscope level, the pseudostratified epithelium of zone II is characterized by tall principal cells that are densely packed with large, intensely staining granules or droplets ranging up to 8μ in diameter. At the electron microscope level, the principal cells exhibit numerous large lipid droplets and abundant agranular endoplasmic reticulum, which is frequently arranged in concentric whorls around one or more of the droplets. Quantitative biochemical studies comparing zone II with zones I and III show that zone II contains 2.5–3‐fold more cholesterol and a significantly greater amount of cholesterol ester than the other two zones. These data indicate that the epididymal duct of the guinea pig includes a clearly defined region of epithelial cells possessing ultrastructural and biochemical characteristics consistent with steroidogenic activity. The potential significance of these observations to the epididymal physiology of the guinea pig and epididymal physiology in general is discussed.
Trophic effect of the sympathetic nervous system on the early development of the rat parotid gland: A quantitative ultrastructural study
Authors: Bloom Gunnar D. , Carlsöö Bengt , Danielsson Åke , Hellström Sten , Henriksson Roger 
Published: February 2005

AbstractRats were sympathetically denervated on one side by avulsion of the superior cervical ganglion either immediately after birth (within 4 hr) or when the salivary glands were fully developed. Nine weeks after ganglionectomy the parotid glands were subjected to microscopical studies. As shown by the lack of specific fluorescence, sympathetic denervation caused an almost total depletion of catecholamines in the acini. This was further substantiated at the electron microscopic level using KMnO4 as fixative. No alterations in either gland weight or in acinar cell size were noticeable after adult sympathectomy. On the other hand, neonatal denervation caused a decrease in gland weight as well as acinar cell hypotrophy. The mean volume of individual acinar cells was reduced by roughly 25% and the granule volume density by about 50%. Also the mean volume of individual granules was decreased. These findings indicate an important role for the sympathetic nerve system in the maturation of the rat parotid gland.
Ultrastructural changes during stimulation of amphibian oxyntic cells viewed by scanning and transmission electron microscopy
Authors: Logsdon Craig D. , Machen Terry E. 
Published: February 2005

AbstractAmphibian oxyntic cells exposed by cryofracture were examined by field emission scanning electron microscopy. Comparisons were made between the structure thus revealed and those seen in thin‐sectioned material from the same mucosas examined by transmission electron microscopy. Resting oxyntic cells had apical surfaces which were relatively smooth with some short microvilli. Apical cytoplasm was filled with smooth membrane tubules (so‐called vesicotubules). Stimulation with a combination of histamine, dibutyryl cyclic AMP, and isobutylmethylxanthine (a phosphodiesterase inhibitor) led to a dramatic elaboration (i.e., increased membrane surface area) and a decrease in number of vesicotubules in the apical cytoplasm. The surface morphology of the stimulated oxyntic cell was much different from that reported for the mammalian parietal cell. Two types of surface elaboration were observed. Most commonly the surface was formed of flattened microplicae or lingulae. An irregular surface formed by the swelling of enlarged spaces near the apical surface was also observed. These new data have been used to evaluate the models which have been proposed to explain the nature of the transition from resting to stimulated morphology. A new model, which incorporates fusion of intracellular vesicotubules with each other and also with apical membrane, is proposed. The proposed fusion process may cause an increase in membrane area open to the extracellular (luminal) solution within the cell (rather than the eversion of membranes into the gastric lumen). Expansion of spaces between the microplicae may be caused by hydroosmotic pressures developed during active HCl secretion.
Organ distribution and fate of newly formed splenic lymphocytes in the pig
Authors: Pabst R. , Nowara E. 
Published: February 2005

AbstractThe production of lymphoid cells in the pig spleen was studied autoradiographically after selective labeling of the spleen using an extracorporeal perfusion circuit. Tritiated thymidine was added as a DNA precursor. One to 4 days after local labeling of the spleen the relative and absolute number of spleenderived lymphocytes were determined in the following organs: mesenteric, cervical and inguinal lymph nodes, thymus, bone marrow, Peyer's patches, tonsils, three different parts of the gut, lung, liver, and blood. The labeled lymphocytes which migrated to these organs were all small lymphocytes, except for some large cells in the lamina propria. In the bone marrow, however, a considerable number of the spleen‐derived immigrants were transformed into plasma cells. The total number of labeled lymphocytes decreased dramatically from Day 1 to Day 4 after labeling, indicating a high percentage of short‐lived cells. Within the spleen, plasma cells had the highest labeling index of about 30% at Day 1 but this dropped to only 1.5% on Day 3. The organ distribution of the splenic emigrants changed from Day 1 to Day 4 with a relative increase in lymphocytes found in lymph nodes and a decrease in the lung and the intestinal wall. The newly formed splenic lymphocytes migrated to T‐ and B‐cell areas in lymph nodes, Peyer's patches, and tonsils. In the intestinal wall labeled lymphocytes were found in the lamina propria and also as intraepithelial lymphocytes. There was no obvious redistribution between organ compartments with time after labeling of the spleen. The spleen produces large numbers of lymphocytes, which show typical organ distribution and homing to areas in lymphoid and nonlymphoid organs.
Axoglial synaptoid contacts in the neural lobe of the human fetus
Authors: Okado Nobuo , Yokota Norio 
Published: February 2005

AbstractAxoglial synaptoid contacts as well as junctional specializations were examined in the neural lobe of five human fetuses ranging from 7.5 to 19 weeks of ovulation age. Because synapselike contacts (SLC), which have both presynaptic and postsynaptic densities, were observed only in the youngest fetus (7.5 weeks), they may be transient structures. Axoglial SLC were also found in older fetuses, but their structural characteristics were different from those found in a 7.5‐week fetus in that the cytoplasmic membrane density was found only on the presynaptic side and its extent was decreased.In the youngest fetus observed here (7.5 weeks), puncta adherentia were observed. In the fetuses older than 11 weeks, gap junctions, long adherentia‐type junctions with thick filamentous structures, and mixed junctions with both types of contact were found between pituicytes.
The ability to predict weight gain, individual organ weight, and corresponding food intake in the rat by the four‐parameter model for physiological responses
Authors: Schweisthal Michael R. , Cole Thomas B. , Mercer L. Preston 
Published: February 2005

AbstractThe applicability of the four‐parameter model for physiological responses to the prediction of food intake and corresponding weight gain and individual organ weight gain was studied further in 40‐day postpartum male rats. Seven groups of animals were maintained on diets in which protein content ranged from 0 to 23.54% casein. Food intake and weight gain were recorded every other day for each animal for 21 days. At the termination of the experiment the following organs were removed and weighed: liver, heart, lungs, spleen, kidneys, adrenals, and testes. When these weight values are fitted by use of the four‐parameter model, food intake and total animal and organ weight gains can be predicted in relation to the amount of protein in the diet. It was found that liver, heart, lungs, spleen, and whole animal had similar K(0.5) values. However, it was also shown that there is variation in response of organs when relating organ weight as a percentage of body weight. For example, heart, lungs, and testes show an increased ratio on low protein diet while liver, kidneys, and adrenals maintain a fairly constant ratio and the spleen shows a decreased ratio. Additionally, it was noted that the animals on low protein diet consumed more food per gram body weight but did so at a slower rate. Possible future applications of the four‐parameter model for physiological reponses are discussed.
Correlation between growth rate and cytochemistry in morris hepatomas
Authors: Kang Yuan‐Hsu , Morris Harold P. , Criss Wayne E. 
Published: February 2005

AbstractThe correlation between the cytochemistry (glycoprotein, glycogen, glucose‐6‐phosphatase, catalase, alkaline phosphatase) and the growth rate of the fast‐growing Morris hepatoma 3924A and the slow‐growing Morris hepatoma 9618A was studied by utracytochemical techniques.By the chromic acid‐phosphotungstic acid technique, acid glycoprotein is stained in glycocalyx, Golgi saccules and vesicles, and secretory granules of the tumor cells of both hepatomas. However, the hepatoma 3924A cells contain thicker glycocalyx and more numerous glycoprotein‐rich granules than hepatoma 9618A cells. Abundant alpha and beta glycogen particles are present in the hepatoma 9618A cells, whereas extremely few beta particles are found in hepatoma 3924A. Moderate glucose‐6‐phosphatase activity is observed in the cisternae of endoplasmic reticulum and nuclear envelope of hepatoma 9618A, but it is totally absent in hepatoma 3924A. High catalase activity is present in numerous peroxisomes of hepatoma 9618A. Hepatoma 3924A contains only a few catalase‐positive microperoxisomes. Weak to moderate alkaline phosphatase is present in the plasma membrane and nuclear envelope of hepatoma 9618A cells, while hepatoma 3924A shows no activity of the enzyme. All the cytochemical parameters except glycoprotein show an inverse relationship with the growth rate of the hepatomas. The higher intracellular glycoprotein content of hepatoma 3924A may be related to differences in cell coat secretion (composition and activity) from the slower‐growing hepatoma 9618A.
Sperm autoantigens and fertilization. III. Ultrastructural localization of guinea pig autoantigens
Authors: Tung Kenneth S. K. , Yanagimachi Hiroko , Yanagimachi Ryuzo 
Published: February 2005

AbstractGuinea pig sperm autoantigens have been localized by direct and indirect immunoferritin techniques in (1) plasma membrane over the entire sperm head, (2) acrosomal contents, (3) fibrous sheath and outer dense fibers of the tail filament, and (4) the inner acrosomal membrane of 50% of acrosome reacted spermatozoa. These cellular structures are known to be involved in guinea pig sperm rouleaux formation, acrosome reaction, interaction of acrosome‐reacted sperm with zona pellucida and with the vitellus of guinea pig ova. Since IgG and Fab of autoantiserum to guinea pig spermatozoa have been shown to interfere with these cellular reactions, this study provides further evidence, albeit indirect, that sperm autoantigens are involved in these cellular events.
Parabiosed rabbit ears: An innovation for experimental subcutaneous implantation
Authors: Grimes L. Nichols 
Published: February 2005

AbstractA new technique is described for the experimental implantation of material subcutaneously into the rabbit ear's auricula without having to cut the skin at the surface of the site. This technique is important because the integument's vascular suppy to the implantation site is not severed as it is with other implantation techniques. The techique consists of resecting all the tissue except one integument from a circular site on each of the rabbit's auriculae. Then the two auriculae are parabiosed at these sites with the implant inserted between them.
Acid and alkaline phosphatase activity in migrating primordial germ cells of the early chick embryo
Authors: Swartz William J. 
Published: February 2005

AbstractLittle information is available concerning enzyme activity in primordial germ cells (PGCs) of the early chick embryo. The present study is designed to examine the disposition of alkaline and acid phosphatase activity in the PGCs during their migration into the developing gonads of the early chick embryo. White Leghorn chick embryos were sacrificed at daily intervals from 1 to 6 days of incubation. Following sacrifice the embryos were fixed, dehydrated, and embedded in glycol methacrylate (GMA). Alkaline and acid phosphatases were demonstrated by the simultaneous diazo‐coupling method. The embryonic tissues at the different ages were examined for PGCs and the histochemical reactions for alkaline and acid phosphatases in these cells evaluated. Acid phosphatase activity did not appear within PGCs until 3 days of incubation, and then in only a few PGCs in the active phase of their migration in the dorsal mesentery, suggesting that there is no large wave of degeneration of these cells during migration. Alkaline phosphatase activity was observed as early as 2 days of incubation in PGCs during the passive phase of their migration in extraembryonic blood vessels. Alkaline phosphatase‐positive PGCs in the active phase of migration were also found in the dorsal mesentery; however, the cellular localization of this enzyme differed from that observed in the passively migrating PGCs, indicating that there are alterations in the metabolic activities of these cells during the active and passive phases of migration.
Cell specialization in collecting tubules of the guinea pig kidney: Carbonic anhydrase activity and glycosaminoglycan production in different cells
Authors: Sato Akira , Spicer Samuel S. 
Published: February 2005

AbstractThe distribution of complex carbohydrates has been investigated cytochemically at the light and electron microscope levels in collecting ducts of the guinea pig kidney. The dialyzed iron method demonstrated acidic complex carbohydrate ultrastructurally on the outer surface of the apical and the basolateral plasmalemma of the principal cells and in their maturing Golgi cisternae and secretory granules. Glycoconjugate in these sites stained for sulfate esters with the high iron diamine method but lacked reactivity toward the periodic acid‐thiocarbohydrazide‐silver proteinate (PA‐T‐SP) sequence for visualizing vicglycol‐containing glycoprotein. Lability to testicular hyaluronidase and resistance to sialidase identified the Glycosaminoglycan (GAG) in principal cell granules and the plasmalemmae as a chondroitin sulfate. In contrast, intercalated cells of the collecting ducts failed to stain with the cationic reagents, but showed light PA‐T‐SP reactivity demonstrative of neutral glycoprotein in the glycocalyx of the apical plasmalemma. Immunostaining with the immunoglobulin‐enzyme bridge procedure localized carbonic anhydrase selectively to the intercalated cells. The ultrastructural and cytochemical observations on the guinea pig collecting ducts implicate intercalated cells in fluid and electrolyte transport and principal cells in secretion of a chondroitin sulfate to the tubule lumen and intercellular space.
Ultrastructural localization of alkaline and acid phosphatases in the human fallopian tube epithelium during the menstrual cycle
Authors: Lindenbaum Ella S. , Beach Dvorah , Peretz Bezalel A. 
Published: February 2005

AbstractUltrastructural and cytochemical methods were utilized to study the human Fallopian tube fimbrial epithelium during the different stages of the menstrual cycle.Alkaline phosphatase reaction product was located along the apical and lateral plasma membranes of the secretory cells only, regardless of the stage of the cycle. The ciliated cells were almost devoid of any reaction product at all stages of the cycle.Acid phosphatase reaction product depicted the lysosomes. These appeared as electron‐dense bodies, of almost equal numbers in the ciliated and the secretory cells at all stages of the cycle. Thus the number of lysosomes did not vary appreciably during the different stages of the menstrual cycle. Many lipid droplets were found in both cells; these were rimmed by acid phosphatase reaction product, and some were partially enveloped by electron‐dense bodies containing acid phosphatase deposits. Acid phosphatase deposits were also found on the inner face of Golgi vesicles.
Morphometric changes in the lungs of rats following adrenalectomy supplemented by desiccated thyroid
Authors: Adkisson V. T. , Callas G. 
Published: February 2005

AbstractStudies were conducted to assess the effects of thyrotoxicosis on the lung of the adult adrenalectomized rat. The animals were divided into four groups of seven animals each: Adrenalectomized animals receiving desiccated thyroid in their food for 8 weeks, adrenalectomized animals, and sham‐operated animals receiving regular laboratory chow. Unoperated animals were used as controls. There were no differences in the pressure‐volume curves or morphometric parameters between unoperated‐control and sham‐operated animals; therefore they will be collectively reported as control animals. Lung volume in the thyroid‐treated animals showed an increase of 19% in pressure‐volume studies when compared with the other groups. Lung volume determined morphometrically demonstrated a 19% increase in volume when adrenalectomized thyroid‐treated rats were compared with control amimals, and a 29% increase compared with adrenalectomized animals. The thyroid‐treated animals also showed an alveolar surface density (Sva) increase of 58% over control and 28% over adrenalectomized animals. In addition, alveolar surface area (Sa) of the treated animals was 89% greater than control and 65% greater than adrenalectomized animals. The marked difference in the surface‐to‐volume ratio indicates that alveoli were smaller and more numerous in the lungs from the thyroid‐treated animals. These results are readily apparent in examination of light microscopic sections of the lung specimens from the four groups of animals. These findings indicate that chronic thyroid administration results in a significant increase in lung volume, which we attribute to increased alveolar partitioning.