bluuebunny/crossref_metadata_2025_split huggingface dataset:
Muscle cell membranes from early degeneration muscle cell fibers in Solenopsis are leaky to lanthanum: Electron microscopy and X‐ray analysis
Authors: Jones Ruth Gwendolyn , Davis Walter L. 
Published: February 2005

AbstractLanthanum infusion techniques, transmission electron microscopy, and X‐ray microanalysis were utilized to compare the permeability of muscle cell membranes from normal and degenerating muscle fibers of Solenopsis spp. In normal fibers, the electron‐dense tracer was limited to components of the sarcotubular system. However, the insemination‐induced degeneration of muscle fibers was characterized by the presence of an electron‐dense precipitate within the myofibrils and mitochondria as well as in the extramyofibrillar spaces. The electron‐dense material was subsequently identified by elemental analysis to be lanthanum. Such data indicate that one of the earliest stages of muscle degeneration involves an alteration in cell membrane permeability.
Globule leukocytes in the respiratory epithelium of human upper airways: An ultrastructural study
Authors: Baert Johan , Frederix Maria 
Published: February 2005

AbstractThe ultrastructure of globule leukocytes is described in the nasal and tracheal respiratory epithelium of three boys suffering from chronic airway infections. The globule leukocytes lie free in the intercellular spaces and appear to be migratory cells. They are characterized by intracytoplasmic membrane‐bound globules, variable in number, size, shape, and internal structure. The globules may apparently release their content between the neighboring epithelial cells. Human globule leukocytes are also characterized by the presence of intracytoplasmic rod‐shaped bodies, the significance of which is not known. They usually display an extended juxta‐nuclear Golgi apparatus, presumably involved in the formation of the globules. Comparison of the fine structure of the globules in the globule leukocytes with that of the granules found in the subepithelial mast cells does not support a mast cell origin for human globule leukocytes. On morphological grounds, natural killer cells are postulated as a possible source for globule leukocytes. The function of globule leukocytes is briefly discussed. We presume that the globule leukocytes belong to the group of migrating and secreting cells involved in the defense of the organism against foreign material.
Interruption of the middle cerebral artery in 10‐day‐old rat alters normal development of distal collaterals
Authors: Coyle Peter 
Published: February 2005

AbstractPial surface arterioles join rami of the anterior and middle cerebral arteries (MCA) in 10‐day‐old normal Wistar rats. Normally, the anastomosing branches differentiate into small‐diameter vessels with significantly greater tortuosity (length) by 56 days of age. After interruption of the MCA in 10‐day‐old rats, large‐diameter, relatively straight collaterals were observed 46 or 90–110 days later. Evidently altered hemodynamic factors, as the result of MCA interruption, prevent the development of a normal pattern of arterioles and augment the development of an anomalous pattern of collaterals in young Wistar rats.
Dose‐dependent movement of cationic molecules across the glomerular wall
Authors: Andrews Peter M. , Bates Sally B. 
Published: February 2005

AbstractDifferent concentrations of the polycation polyethyleneimine (PEI) were administered by single intravenous injections or by constant vascular perfusion to the kidneys of Sprague‐Dawley rats. At a fixed time interval after administration of PEI, the kidneys were fixed and the distribution of PEI in the glomerular wall was evaluated by electron microscopy. At the lower concentrations (e.g., 0.005%), PEI bound only to the glomerular endothelial glycocalyx and preferentially to microvillous projections on this endothelium. At higher concentrations (e.g., 0.05%), PEI also bound to discrete anionic sites in the lamina rara interna (LRI) but was rarely seen in the lamina rara externa (LRE). As the concentration of PEI was further increased (e.g., 0.5%), PEI moved deeper into the glomerular basement membrane (GBM) and bound extensively to discrete anionic sites in the lamina rara externa. Although anionic sites in the LRI and LRE appeared nearly saturated following infusion of 0.5% PEI, this cationic molecule was rarely seen to cross filtration slits and pass into the urinary space. At still higher concentrations (e.g., 2%), however, PEI moved freely across the filtration slits, bound extensively to the glomerular epithelial glycocalyx, and induced a narrowing of the filtration slits. When PEI was mechanically perfused through the kidney vasculature for 3 minutes, PEI binding to the epithelial glycocalyx caused very extensive adherence of adjacent podocyte processes and the narrowing and loss of filtration slits. Also in these latter samples, discrete anionic sites in the LRE were no longer apparent and a dense band of PEI was seen under the foot processes. Addition of PEI to culture media containing intact glomeruli revealed that even in the absence of hemodynamic driving forces, the PEI used in the above studies will gradually move across the glomerular basement membrane and bind to anionic sites throughout the glomerular wall. The above observations suggest that anionic sites in the glomerular wall may trap cationic molecules and thereby prevent low concentrations of these molecules from passing deeper into the glomerular wall and gaining entrance to the urinary space.
Effects of L‐azetidine‐2‐carboxylic acid on matrix secretion and Golgi structure in fibroblasts and osteoblasts of the mouse
Authors: Cho Moon‐Il , Garant Philias R. 
Published: February 2005

AbstractThe effect of a proline analogue, L‐azetidine‐2‐carboxylic acid (LACA), on collagenous matrix secretion by periodontal ligament fibroblasts and alveolar bone osteoblasts was studied by light and electron microscopic radioautography after injection of 3H‐glycine; 3H‐glycine labeled material accumulated in the cisternae of the rough endoplasmic reticulum and was not secreted for over 4 hours.The Golgi complex of both fibroblasts and osteoblasts showed a marked alteration of its composition after LACA administration. All Golgi saccules and collagen secretion granules disappeared within 2 hours. Flattened Golgi cisternae were still present and appeared to be unaffected by the administration of LACA.These observations indicate that Golgi saccules in collagen‐secreting cells are the initial staging areas for the formation of collagen secretory granules and that there is a close correlation between form and function in the Golgi apparatus of collagensecreting cells.
Ultracytochemical and biochemical evidence for guanylate cyclase in guinea pig testis
Authors: Pascolini Rita , Spreca Antonio , Lorvik Sergio , Fagioli Oliviero , Fanó Giorgio 
Published: February 2005

AbstractGuanylate cyclase activity has been studied biochemically and cytochemically in guinea pig testis. The results of the biochemical assays indicate an equal distribution of this enzyme between the soluble and particulate fractions, which have a different sensitivity to adenosine triphosphate. The cytochemical results demonstrate that the reaction product of guanylate cyclase is detectable in the interstitial capillary endothelial cells and, in the seminiferous epithelium, mainly at the level of the adjacent surfaces of Sertoli and germ cells of the intermediate and adluminal compartments. Guanylate cyclase activity appears at the level of pachytene spermatocytes and persists throughout subsequent stages of development. The distribution in the seminiferous epithelium seems to indicate that guanylate cyclase is involved in the interrelationships between Sertoli and germ cells during gamete differentiation.
Lectin binding sites on human sperm and spermatogenic cells
Authors: Lee Mao‐Chi , Damjanov Ivan 
Published: February 2005

AbstractTestes of sexually mature men were studied histochemically with 20 fluorescein isothiocyanate‐labeled lectins. Based on their pattern of reactivity with intratesticular spermatogenic cells, lectins were divided into five groups: (1) lectins reacting with all spermatogenic cells (Suc. ConA, WGA, LCA, PHA‐E, PHAL, STA, MPA, and RCA‐II); (2) lectin reacting with spermatocytes, spermatids, and spermatozoa, but not with spermatogonia (RCA‐I); (3) lectins reacting with spermatids and spermatozoa only (BPA, PNA, SBA, and VVA); (4) lectins reacting only with spermatozoa (HPA, GSA‐I, UEA‐II, and GSA‐II); and (5) lectins with no distinct staining of spermatogenic cells (DBA, LBA, and UEA‐I). All lectins from groups 1–4 were reactive with ejaculated spermatozoa. On the basis of the staining patterns of the head region of ejaculated spermatozoa, four lectin reactivity groups were defined: (1) lectins reacting with the plasma membrane of the whole head (BPA, WGA, LCA, STA, RCA‐II, PHA‐E, PHA‐L, RCA‐I, UEA‐II, and GSA‐II); (2) lectin reacting with the acrosomal cap and postacrosomal region of the plasma membrane (Suc. ConA); (3) lectin reacting with the acrosomal cap region of the plasma membrane (PNA); and (4) lectins reacting with the midregion of the sperm head in a bandlike manner (HPA, VVA, SBA, GSA‐I, and MPA). These data provide a map of lectin binding sites on human testicular spermatogenic cells and ejaculated spermatozoa and show that the distribution of glycoconjugate domains of spermatogenic cell changes during differentiation and maturation.
Morphological changes in atretic graafian follicles during induced atresia in the hamster
Authors: Hubbard C. J. , Greenwald G. S. 
Published: February 2005

AbstractHypophysectomized female hamsters primed with 30 i.u. pregnant mare serum gonadotropin (PMSG) were injected with anti‐PMSG serum 72 h later to induce atresia in Graafian follicles. The earliest histological evidence of atresia was seen in the cumulus oophorus at 4 h with a significant increase in pyknotic nuclei. The mural granulosa cells, however, did not show pyknoses until 12 h following anti‐PMSG serum. The highest number of pyknotic nuclei in the cumulus oophorus was seen at 24 h, when pseudomaturation of the oocyte occurred. Breakdown of the mural granulosa cells was greatest by 48 h. Morphometric measurements of the follicles showed a significant decline in the thickness and area by the granulosa layer at 48 h following injection of anti‐PMSG serum.The thecal compartment showed a decline in number of mitoses at 4 h and 12 h and in area at 48 h. However, no pyknotic thecal cells were observed during the 72 h following injection of anti‐PMSG serum. The results support previous work using this model, which showed major biochemical changes in the granulosa cells at 12 and 48 h. The theca, however, was comparatively unaffected during atresia. The various studies using this model shew changes in atretic follicles similar to those seen in other models and in the intact animal. The major advantage of this medel is that it produces a large synchronous population of follicles that rapidly becomes atretic.
Functional gap junctions in mouse small intestinal crypts
Authors: Bjerknes Matthew , Cheng Hazel , Erlandsen Stanley 
Published: February 2005

AbstractWe demonstrate intercellular transfer of Lucifer yellow and the existence of gap junctions in isolated mouse small intestinal crypts. The pattern of dye transfer approximates the normal pattern of cell proliferation and differentiation in the intestinal epithelium. These findings indicate that the cells of normal crypts form an effective intercellular continuum. This intercellular route may function in the establishment of chemical, ionic, or electrical fields, which in turn may play a role in the control of cell proliferation, differentiation, and secretion in the crypt.
Macrophage‐like cells in the muscularis externa of mouse small intestine
Authors: Mikkelsen H. B. , Thuneberg L. , Rumessen J. J. , Thorball N. 
Published: February 2005

AbstractIn muscularis externa of mouse small intestine, cells with ultrastructural features of macrophages were invariably observed in three layers: in the subserosal layer, between the circular and longitudinal muscle layers, and in association with the deep circular plexus. These macrophage‐like cells (MLC) had a single indented nucleus, perinuclear Golgi complex, smooth and rough endoplasmic reticulum, many pits (coated and uncoated) in the plasma membrane, coated vesicles, light vesicles, and primary lysosomes, but rather few heterogeneous lysosomal vacuoles. MLC were partially enveloped by processes of interstitial cells of Cajal.FITC‐dextran used in combined fluorescence stereo microscopy, fluorescence microscopy, and electron microscopy was employed as a tracer to study the endocytic qualities of the MLC. The mice were killed 5, 15, 30, and 60 min, 1 day, and 4 days after dextran administration. By fluorescence microscopy after 1 or 4 days MLC were observed as a constant cellular population with a strikingly regular distribution. By electron microscopy dextran‐containing vacuoles were conspicuous after 1 h or more. MLC of the subserosal layer and between the circular and longitudinal muscle layers could be distinguished with respect to general appearance, pattern formation, and apparent dextran contents.
Movements at the carpometacarpal and metacarpophalangeal joints of the hand and their effect on the dimensions of the articular ends of the metacarpal bones
Authors: Batmanabane Mounissamy , Malathi Srivatsan 
Published: February 2005

AbstractA detailed study was undertaken to quantify the range of various movements at the carpometacarpal and metacarpophalangeal joints of the hand in cadavers and compare the values so obtained with those in the living, measured with the help of skiagrams. Longitudinal sections of hand were also prepared to bring out the nature of articulations at the carpometacarpal joints. Based on the data available, metacarpal mobility formulae of 1 > 5 > 4 > 2 > 3 for the carpometacarpal, and 5 > 4 > 3 > 2 > 1 and 5 > 2 > 4 > 3 > 1 for metacarpophalangeal joints are being proposed with the hope that these formulae will find their application in the clinical practice to assess the extent of functional damage to these joints as well as to evaluate the rate of progress or deterioration, in course of time. As an extension of our earlier study (Batmanabane, 1982), osteometric analysis of the metacarpus was also carried out and it is confirmed that it is the mobility which determines the osteometric features of the articular ends of these miniature long bones.
Functional units in rainbow trout (Salmo gairdneri) liver: I. Arrangement and histochemical properties of hepatocytes
Authors: Hampton James A. , McCuskey Patricia A. , McCuskey Robert S. , Hinton David E. 
Published: February 2005

AbstractThe architectural arrangement and selected histochemical properties of hepatocytes in the rainbow trout (Salmo gairdneri Richardson) were examined. Light and transmission electron microscopic (TEM) examination following fixation by portal venous perfusion revealed a tubular arrangement of hepatocytes. Lobules, as defined in the adult mammal, were absent. Billary epithelial cells associated with bile preductules and ductules were a prominent feature of trout liver. Patterns and location of reaction products for glucose‐6‐phosphatase (G‐6‐Pase), glucose‐6‐phosphate dehydrogenase (G‐6‐PDH), and magnesium‐dependent adenosine triphosphatase (ATPase), enzymes preferentially distributed in mammalian liver, were demonstrated in trout liver. A slightly heavier staining pattern for G‐6‐Pase was seen around presumptive portal venules but all other enzyme reaction patterns were uniform throughout the liver parenchyma. Following ATPase localization, four sizes of biliary passageways (canaliculi, bile preductules, ductules, and ducts) were visualized. Maximum glycogen retention was achieved with freezedrying and glycolmethacrylate embedding and with this method intense, uniform glycogen staining was observed in all areas of the liver. Companion TEM examinations revealed large depots of glycogen within hepatocytes. The results are important for interpretation and description of the effects of toxic/carcinogenic alteration on trout liver.
The bat pituitary cleft: Phasic production and release of secretory granules by microvillous cells
Authors: Nunez Eladio A. , Payette Robert , Gershon Michael D. 
Published: February 2005

AbstractThe ultrastructure of the two types of cells, ciliated and microvillous, lining the wall of the bat pituitary cleft was examined at different periods during the annual life cycle. Ciliated lining cells remained unchanged in structure throughout the yearly activity cycle. In contrast, microvillous lining cells exhibited striking cyclic morphological changes. Throughout the active phase of the life cycle and during most of the hibernating period, the structure of microvillous cells is unchanged. However, toward the end of hibernation, the cells produce and store large numbers of round to ovoid dense secretory granules. Just prior to arousal, the microvillous cells are packed with secretory granules. At arousal, the cells undergo marked degranulation; the granules appear to be discharged into the lumen of the cleft. Degranulation is followed by a period of proliferation of rough endoplasmic reticulum, the cavity of which is often filled with large paracrystalline inclusions. Within 1 month, microvillous cells return to a resting state and are devoid of secretory granules.
Equine bone marrow: A quantitative analysis of erythroid maturation
Authors: Tablin Fern , Weiss Leon 
Published: February 2005

AbstractThe equine bone marrow responds to blood loss by increased erythropoiesis, only releasing reticulocytes into the peripheral circulation in severe chronic anemia. We have used morphometric analysis based on electron microscopy of the equine marrow to examine the maturation and release of reticulocytes. Developing red cells in the bone marrows of normal and chronically anemic horses were divided into four stages: early, intermediate, late‐stage erythroblasts, and reticulocytes. Morphometric analysis of each stage included volume density of mitochondria per μm3 of cytoplasm, surface area of the outer mitochondrial membrane per unit volume of mitochondria, and the number of ribosomes per unit volume of cytoplasm (total, clustered, single). Matched t tests between normal and anemic animals showed significant differences (P ⩽.001) for volume density of mitochondria and numbers of ribosomes only at the reticulocyte stage. The large reticulocyte produced and released in chronic anemia may be best explained by a skipped mitotic division.
Volumetric changes in the developing rabbit calvarium
Authors: Alberius Per , Selvik GÖRan 
Published: February 2005

AbstractTantalum bone markers were implanted in the frontal, parietal, and temporal bones, at least two in each bone segment, in seven male New Zealand white rabbits. Roentgen stereophotogrammetric analyses were performed for regular intervals between ages 30 to 142 days. With the exception of a few implants in the temporal bone, bone markers remained stable during the observation period. Volumetric and longitudinal growth data were compared. Calvarial polyhedron volumes increased linearly. Growth at the actual neurocranial sutures demonstrated an individually fluctuating pace. No obvious correlation between volumetric and longitudinal growth was noted. This might be explained by sagittal and temporal suture growth in periods being close to the methodological error and failure to document bone rotations. Previous observations on the linearity in cerebral weight increase during corresponding periods of time points to the decisive role of neural mass growth in calvarial development in rabbits. Suture growth characteristics are discussed.
The initiation of osteodentin formation in the rat incisor after adriamycin administration
Authors: Karim A. C. 
Published: February 2005

AbstractIn order to study the initiation of osteodentin formation in rat incisors, animals were injected intravenously with adriamycin (5 mg/kg body weight), and killed from 2 to 7 days after injection by perfusion with a 2.5% buffered glutaraldehyde solution. Control animals, injected with only physiological saline, were treated in the same manner.Three days after adriamycin injection aggregations of mesenchymal cells were observed along the mesial and lateral walls of the pulp chamber. Between 3 days and 7 days osteodentin production was observed at the sites where the mesenchymal aggregations were previously observed. Electron microscopic observations revealed that the cells involved in the aggregates were larger and contained more profiles of rough endoplasmic reticulum and secretion granules than the unaffected pulp cells. The osteodentin matrix first appeared as a scant deposition of collagen fibers between the cells. As more collagen fibers were deposited the matrix became much denser. Some cells that initially formed the mesenchymal aggregates were completely enclosed by the increased deposition of the matrix.It therefore appears that osteodentin formation, as observed in the rat incisor pulp after adriamycin administration, is the result of an abnormal differentiation of pulp mesenchymal cells.
Mast cell heterogeneity in dog skin
Authors: Becker Allan B. , Chung K. Fan , McDonald Donald M. , Lazarus Stephen C. , Frick Oscar L. , Gold Warren M. 
Published: February 2005

AbstractThe degree of metachromasia of mast cell granules is known to vary with the type of tissue fixation and among different tissues and species. The present study sought to determine whether mast cells in dog skin are heterogeneous with respect to fixation and staining properties. We performed skin biopsies in six anesthetized, atopic dogs and one mongrel dog. One biopsy was fixed in formalin and a second, from a parallel abdominal site, was fixed in basic lead acetate (Mota's solution). Adjacent sections from each biopsy were stained with alcian blue (1%, pH 0.5) or for chloroacetate esterase activity. In alcian blue‐stained sections, one‐third fewer mast cells were detected in skin fixed in formalin (1,836 ± 454 mast cells/mm3, mean ± SEM) than in skin fixed in basic lead acetate (2,684 ± 527 mast cells/mm3) (P < 0.05). The chloroacetate esterase reaction detected the larger number of mast cells regardless of the fixative used. We conclude that mast cell heterogeneity, as demonstrated by metachromatic staining following different types of tissue fixation, exists in dog skin. “Typical” mast cells stain with alcian blue regardless of fixation; however, “atypical” mast cells exhibit metachromasia only after fixation in basic lead acetate. Both the typical and atypical types of mast cells have chloroacetate esterase activity.
Ultrastructural visualization of intracellular porphyrin in the rat Harderian gland
Authors: Carriere R. 
Published: February 2005

AbstractThe Harderian glands of male Albino rats 1–24 months of age were studied by electron microscopy. In most glands, a few acinar cells contained straight and curved trilaminar profiles identical in form to the material in the luminal masses of porphyrin pigment. They resembled the structures which several investigators have identified as crystals of protoporphyrin IX in porphyric human and mouse hepatocytes. Protoporphyrin IX is the predominant form synthesized by rat Harderian cells in vitro. The trilaminar profiles were within the cytoplasm but not within the lipid secretory vacuoles.A large number of the acinar cells had finely tubular endoplasmic reticulum (ER). However, cells containing the trilaminar forms consistently had dilated ER vesicles. This change may have been a prelude to cell death, for some pigment‐containing cells attached to the acinar basal lamina also displayed fragmented organelles and a loss of density of the cytoplasmic matrix. In some acinar lumina there was abundant cell debris along with the trilaminar profiles. It is concluded that in the rat, some of the Harderian free porphyrins can be released through cell death.