bluuebunny/crossref_metadata_2025_split huggingface dataset:
Epithelial fusion during early semicircular canal formation in the embryonic zebrafish, Brachydanio rerio
Authors: Waterman Robert Earle , Bell Danny H. 
Published: February 2005

AbstractThe developing inner ear of the teleost, Brachydanio rerio, provides an opportunity for observing an epithelial fusion between the apical surfaces of apposed epithelia in a vertebrate embryo in vivo. The developing otocyst was filmed for periods up to 4 days in unanesthetized embryos, and specimens were fixed at intervals and processed for light microscopy, TEM and SEM. The semicircular canals are formed as a consequence of the union between the tips of three cylindrical projections from the wall of the otocyst, which grow toward corresponding bulges of a projection from the lateral wall. The epithelial cells covering the projections contain extensive rough endopasmic reticulum, exhibit apical junctional complexes, and are not underlain by a basal lamina. The core of each projection contains large amounts of flocculent and fibrillar extracellular material. After a period of growth and elongation, the tip of each projection contacts, and adheres to, the appropriate bulge to create a circular, flattened, bilayered, epithelial plate. Small, focal junctions form between the apposed apical cell surfaces within the plate during this period, but they are not numerous. Junctional complexes do develop, however, between apposed cells at the periphery of the plate. After 1–2 hours, the basal surfaces of the plate exhibit considerable alteration in contour. Adjacent cells within the plate then separate to allow continuity of the connective tissue components of the two structures. The observations of this study indicate that following an initial period of contact and adhesion, cellular reorientation and changes in junctional contacts between adjacent cells within the epithelial plate, rather than cell degeneration, are responsible for perforation of the plate.
A comparison of rat and hamster preovulatory follicles: An examination of differences in morphology and enzyme activity using qualitative and quantitative analyses
Authors: Zoller Lawrence C. 
Published: February 2005

AbstractThe structure and enzymatic content of rat and hamster preovulatory follicles were examined using morphologic, qualitative, and quantitative cytochemical techniques. Interfollicular structure in both types was similar but lipid droplet distribution differed. The rat theca contained many more droplets than the hamster, while the hamster membrana granulosa contained more droplets than the rat. δ5‐3β‐hydroxysteroid dehydrogenase (3βOHD) activity and glucose‐6‐phosphate dehydrogenase (G‐6‐PD) Types IH and IIH generation were measured using quantitative cytochemistry. Rat theca and granulosa contained more 3βOHD activity than found in comparable regions in hamster. G‐6‐PD Type IH and Type IIH generation were the same in comparable regions of rat and hamster, but in rat there was more Type IIH than IH, while the converse existed in hamster. These differences and their relationship to follicular steroid production are discussed.
Diameter and length changes in cerebral collaterals after middle cerebral artery occlusion in the young rat
Authors: Coyle Peter 
Published: February 2005

AbstractRapid occlusion of the middle cerebral artery (MCA) in the 36‐day‐old normal Wistar rat results in change of the dorsal collaterals joining branches of the anterior and middle cerebral arteries. As compared to similarly positioned vessels on the opposite hemisphere and arterioles in unoperated rats of 56 days, of age, there were significantly (P < 0.001) more large (60–120 μm)diameter collaterals on the occluded side 20 days after MCA occlusion. There were fewer small (0‐59μm) diameter collaterals on the occluded side as compared to unoperated rats. The data suggest small diameter arterioles existing at occlusion became large diameter collaterals. The mean number of collaterals per hemisphere was not significantly different (P > 0.05) between occluded and unoperated rats. There was no evidence that new vessels were added during the 20‐day ligation period. The mean collateral tortuosity value was significantly (P < 0.01) greater for large diameter vessels on the right occluded side as compared to vessels on the left hemisphere or vessels in unoperated age‐matched control rats. The greater tortuosity values of vessels on the occluded side were evidence that collateral vessel length was increased by 24–29% after MCA occlusion. Speculation was made about possible mechanisms responsible for these vascular changes.
The radioscapholunate ligament: A gross and histologic description
Authors: Berger Richard A. , Blair William F. 
Published: February 2005

AbstractThe anatomic relationships of the carpal radioscapholunate ligament to its contiguous structures were analyzed by studying (1) 12 grossly dissected fresh adult wrists, and (2) multiple histologic sections from six adult wrists. Observations indicate that the radioscapholunate ligament originates from the prominence between the scaphoid and lunate articular facets on the distal articular surface of the radius, and from the palmar margin of the distal radius, deep and medial to the origin of the radiotriquetral and radiocapitate ligaments. The primary insertion of the radioscapholunate ligament is the medial margin of the proximal pole of the scaphoid. The ligament secondarily inserts into the lateral margin of the lunate and significantly contributes to the proximal portion of the scapholunate interosseous ligament. The radioscapholunate ligament is distinguished morphologically from the other palmar radiocarpal ligaments by its loosely organized collagen fibers and relatively high degree of vascularity. The radiotriquetral and radiocapitate ligaments are composed of densely fasciculated collagen fibers surrounded by perpendicularly oriented perifascicular and epiligamentous fibers. A fibrous capsular layer covers the most superficial aspect of each carpal ligament. On the deep surfaces of these ligaments, a condensation of epiligamentous fibers forms a synovial capsular layer. The palmar radiocarpal ligaments are truly intracapsular structures, as they are interposed between the fibrous and synovial capsular layers. No histologic evidence of elastin is present within the substance of these ligaments.
The mononuclear phagocyte system of the mouse defined by immunohistochemical localisation of antigen F4/80: Macrophages associated with epithelia
Authors: Hume David A. , Perry V. Hugh , Gordon Siamon 
Published: February 2005

AbstractThe tissue distribution of the murine macrophage‐specific antigen F4/80 has been analysed using an immunohistochemical technique. The antigen is observed on all known macrophage populations (including Kupffer cells and bronchoalveolar macrophages) and is absent from any cell types that are definitely not mononuclear phagocytes. Microglial cells from brain express F4/80. F4/80+ macrophages observed associated with epithelia can be divided into two categories, intraepithelial and periepithelial. The former includes epidermal Langerhans cells and cells with similar morphology in other stratified squamous epithelia (cervix, oesophagus), pseudostratified epithelium (trachea), transitional epithelium of urinary bladder, and simple epithelia lining various ducts (salivary gland, common bile duct, tracheobronchial gland). Periepithelial F4/80+ cells, apparently spread immediately below the basal lamina, are associated with simple epithelia throughout the gastrointestinal, respiratory, and male and female reproductive tract as well as the brain ependyma. A major class of periepithelial F4/80+ cells is associated with capillaries throughout the microcirulation. The role of these macrophage populations in control of epithelial function is discussed.
The effects of pelvic neurectomy on collagen in the cervix of the pseudopregnant rat
Authors: Burden Hubert W. , Leonard Marilyn , Smith Carlton P. , Louis Thomas M. , Lawrence Irvin E. 
Published: February 2005

AbstractBilateral section of the pelvic parasympathetic nerves (pelvicneurectomy) on day 5 of pseudopregnancy had no effect on the wet weight of ovaries, uteri, and/or cervices, but at day 9 serum progesterone was reduced to approximately half that of sham‐operated animals. Collagen in the cervix was visualized with picrosirius red staining under polarization microscopy. Pelvic neurectomy decreased the birefringence of Type 1 collagen in the cervix to less than half that of sham operated animals. The decreased birefringence, an index of the organization of collagen fibers, is believed to be attributable to reduced progesterone levels. Alternatively, the pelvic nerve may directly influence mucopolysaccharides or collagenolytic enzymes in the cervix.
Immunohistological demonstration of S‐100 protein in the cutaneous nervous system
Authors: Hachisuka Hiroshi , Mori Osamu , Sakamoto Fumino , Sasai Yoichiro , Nomura Hirofumi 
Published: February 2005

AbstractS‐100 protein, isolated from mammalian brain, has widely been used for immunohistochemical marker of the glia cells and the cells derived from the neural crest. In the present study, we made anti S‐100 protein antibody and studied the immunoreactive distribution of S‐100 protein in the cutaneous nervous system. Albino rabbits were immunized with S‐100 protein and complete Freund adjuvant, and antiserum was purified by ion‐exchange chromatography. Formalin‐fixed normal human skin and sciatic nerve of rat were examined by the PAP method. S‐100 protein was detected in Schwann cells of sciatic nerve of rat and cutaneous nerve bundles of human skin specimens. Meissner corpuscles and inner core cells of Pacinian corpuscles of human skin were S‐100 protein positive. These findings suggest that the staining of S‐100 protein with PAP method is a simple and reliable method to demonstrate the cutaneous nervous system. Also, lamellar cells of Meissner corpuscles and inner core cells of Pacinian corpuscles are indicated to be Schwann cell origin.
Intranuclear inclusions in rat piriform cortex: Increase with age and preferential location within superficial layer II
Authors: Curcio Christine A. , McNelly Nancy A. , Hinds James W. 
Published: February 2005

AbstractIntranuclear inclusions have been observed in layer II neurons of rat piriform cortex. These inclusions have the form of a filamentous lattice and resemble those described by others previously. The frequency of lattice‐containing nuclei shows a significant fourfold increase over a period of 3–33 months of age, with the largest increase occurring after 18 months. The incidence of these inclusions is highest in the superficial third of layer II and is significantly greater than what would be expected from the distribution of all neuronal nuclei in layer II. The presence of intranuclear lattices may be related to the high level of electrical activity in piriform cortex, and their increase with age may reflect a long‐term cumulative effect of this activity.
The effect of adriamycin on rat incisor one day after administration
Authors: Karim A. C. 
Published: February 2005

AbstractThe effect of adriamycin on rat incisor was investigated 1 day after administration. Rats were injected intravenously with adriamycin at a dose of 5 mg/kg body weight and sacrificed by perfusion with a 2.5% phosphate buffered glutaraldehyde solution. The principal effect of the drug on the incisor was the production of cell degeneration. This was extensive in the apical region, being present along the entire periphery of the dental papilla. In sections examined more incisally, cell degeneration gradually disappeared from the labial portion of the incisor but was present in the lingual portion. This degeneration of cells was not present at the site where mature odontoblasts had differentiated on the lingual surface of the pulp chamber. It appears that the affected cells were early preodontoblasts and the precursors of preodontoblasts. However, as these cells became more differentiated they apparently became more resistant to the drug's effect.
A practical method for staging metamorphosis in the tiger salamander Ambystoma tigrinum
Authors: Norman Mark F. 
Published: February 2005

AbstractThe aim of this study was to develop a set of practical metamorphic stages for the tiger salamander Ambystoma tigrinum that would (1) provide an early and quantifiable marker of the onset of metamorphosis and (2) not be dependent on knowledge of maximal values of gill length or tail height. Twenty morphological parameters were obtained from Ambystoma tigrinum larvae as they progressed through laboratory‐induced metamorphosis (21°C, continuous light). These parameters included measures of body weight, gill length, and tail height. Initiation or duration of metamorphosis could not be predicted when parameters were expressed relative to the number of days larvae were held in laboratory conditions.Early phases of metamorphosis were characterized by regression of the lower tail fin. Selected morphological parameters were expressed relative to the day on which each subject exhibited complete regression of the lower fin. This technique made it possible to order these parameters into a progressive series of metamorphic phases. Seven stages of metamorphosis were derived from this series, ranging from larvae (stage I) to complete regression of the gills (stage VII). Application of these stages does not require prior knowledge of maximal (initial) values of gill length or tail height.
The cellular distribution of calcium in freeze‐dried rabbit vas deferens using em autoradiography
Authors: McGuffee Linda J. , Wheeler‐Clark Ellyn S. , Skipper Betty J. , Little Sally A. 
Published: February 2005

AbstractThe role of calcium in initiating smooth muscle contraction is widely accepted. The sources of this calcium are thought to be located both intracellularly and extracellularly. We have recently developed a method by which the cellular localization of calcium in smooth muscle can be determined. This method involves exposing the tissue to 45Ca, rapidly freezing and vacuum dehydrating the tissue, and preparing the tissue for electron microscopic autoradiography (EM ARG). In the present study the distribution of calcium in control and potassium‐contracted tissue of the rabbit vas deferens was compared. No significant differences in distribution were observed in the two treatments. This finding provides morphological support for the hypothesis that the calcium used in potassium‐induced contraction is primarily of extracellular origin. In addition, significant sequestration by intracellular organelles does not occur during a potassium contraction. In other experiments, the effect of rinsing tissue in cold calcium prior to freezing was investigated. From these data is appears that calcium is removed from the cytoplasmic matrix, plasma membrane, and organelles in a nonuniform manner. Further investigation into these findings should enable us to characterize more precisely the intracellular redistribution of calcium that occurs as a result of a variety of physiological manipulations.
Scanning electron microscopic observations of casts of human dentinal tubules along the interface between primary and secondary dentine
Authors: Wang Yien Nan , Ashrafi Shahid H. , Weber Dennis F. 
Published: February 2005

AbstractA scanning electron microscope cast technique was used to examine the interface between primary and secondary dentine in young and old human teeth. In addition, more traditional methods were used to examine this interface with light microscopy, identical regions being viewed before and after demineralization. No continuity was seen between the tubules in primary dentine and those in irregular secondary dentine in the scanning electron microscope preparations. These preparations did show the tubules to be continuous between primary dentine and regular secondary dentine in young and old teeth. Both the scanning electron microscopic and light microscopic observations suggested that regular secondary dentine becomes highly sclerosed in old teeth.
Pit cells in extrahepatic organs of the rat
Authors: Kaneda Kenji , Wake Kenjiro 
Published: February 2005

AbstractElectron microscopic examination of the extrahepatic distribution of pit cells, a cell type found in the liver, revealed their existence in several other organs of the rat. They were (1) relatively frequent in lungs, spleen (red pulp), small intestine, epididymis, trachea, and peripheral blood; (2) much fewer in bone marrow and thymus (medulla); and (3) nonexistent in lymph nodes, spleen (white pulp), and thymus (cortex). The pit cells in these organs, as well as in the liver, contained characteristic dense granules and rod‐cored vesicles in the cytoplasm. Our observations suggest that pit cells circulating in the peripheral blood adhere to the endothelium of capillaries in the various organs and migrate into the tissue, where they have some special immunological function.
Matrix compartments in the growth plate of the proximal tibia of rats
Authors: Eggli Peter S. , Herrmann Wolfgang , Hunziker Ernst B. , Schenk Robert K. 
Published: February 2005

AbstractThe cartilaginous matrix in the growth plate of the proximal tibia of rats is subdivided into various compartments according to criteria established by electron microscopic examination. In conventionally fixed specimens, the arrangement of collagen fibrils was analyzed by transmission and scanning electron microscopy. Distribution of proteoglycans and relations between matrix and cells were studied after fixation in media containing cationic dyes. Matrix compartments are best characterized by the density and arrangement of their collagen fibrils. On the other hand, proteoglycans are distributed almost homogenously all over the matrix. Each chondrocyte is surrounded by a thin envelope of proteoglycans, the pericellular matrix. Adjacent to this is a layer dominated by the content and order of its collagen fibrils, the territorial matrix. Its inner part covers the pericellular matrix with a thin net of intersecting fibrils. The outer part unites the cells of each column by a sheath of tightly packed longitudinal fibrils. This distinction is only possible in the longitudinal parts of the territorial matrix, whereas in the transverse septa both layers fuse into a common network. The interterritorial matrix is interposed between the columnar units and thus represents the central part of the longitudinal septa. Mineralization is restricted to the interterritorial matrix and matrix vesicles are coincidentally found in the same compartment. During growth, this structural organization undergoes a permanent and relatively fast remodeling, a process that is discussed in view of possible cell matrix interactions.
Progenitor cell populations in the periodontal ligament of mice
Authors: McCulloch C. A. G. 
Published: February 2005

AbstractStem cells in a variety of renewal tissues exhibit a slow rate of cell proliferation (Potten et al., 1979). The periodontal ligament of mouse molars was examined for the presence of slowly cycling progenitor cells to provide evidence for the existence of stem cells in this tissue. A pulse injection of 3H‐thymidine was administered and mice were sacrificed between 1 hour and 14 days after injection. Analysis of radioautographs using percentage of labeled cells and grain counts demonstrated that a population of label‐retaining cells within 10 μm of blood vessels traversed the cell cycle more slowly than proliferating cells located greater than 10 μm from blood vessels. These data suggest that there is a slowly dividing population of progenitor cells in paravascular sites in mouse molar periodontal ligament which may be stem cells.
Constant position of the superficial cerebral veins of the rat: A quantitative analysis
Authors: Bardosi Attila , Ambach Georg 
Published: February 2005

AbstractThe normal anatomical position of the point of junction of the superficial cerebral veins with the superior sagittal and transverse sinuses of the rat was studied with an analytical mathematical method. There were eight fixed veins, each characterized by a constant point of juncture having minimal variance. The findings indicate that the points of juncture between large veins and sinuses are developmentally fixed and that there is a definite order in the number and the territories of the large veins.
Fiber type composition of monkey forearm muscle
Authors: McIntosh Joan S. , Ringqvist Margareta , Schmidt Edward M. 
Published: February 2005

AbstractHistochemical staining methods were applied to selected superficial forearm muscles of Macaca mulatta monkeys. The muscles were analyzed with regard to relative percentage distribution of different fiber types. In extensor carpi radialis brevis, extensor carpi radialis longus, and palmaris longus there was an even dispersion of each fiber type from the superficial to the deep part of the muscle. Extensor digiti communis showed a slightly higher percentage of type I fibers and correspondingly lower percentage of type II fibers in its central as compared to its superficial area. Three muscles, bracioradialis, extensor carpi ulnaris, and flexor carpi radialis, displayed marked differences between their superficial and deep areas. All of them contained a higher proportion of type I fibers (and correspondingly lower percentage of type II fibers) in their deep parts than in their superficial areas.Flexor carpi ulnaris (FCU) differed from the other muscles studied in that it showed distinctly different fiber proportions on either side of a central tendon. While the ulnar head of FCU was dominated by type II fibers (71% compared to 27% type I fibers), the humeral head contained a larger proportion of type I fibers (58% vs. 40% type II fibers). This difference in fiber type distribution suggests different functional demands for the two heads of FCU, with the possibility of more sustained activity in the humeral head.
Diabetes‐associated alterations in uterine structure in the C57BL/KsJ Mouse: Relationship to changes in estradiol accumulation, circulating ovarian steroid levels, and age
Authors: Garris David R. 
Published: February 2005

AbstractThe effects of the diabetes (D) mutation on utero‐ovarian structure and function were examined in match‐paired D and control (C) C57BL/KsJ mice between 2 and 16 weeks of age. Between 4 and 8 weeks of age, the uterine epithelium of D mice exhibited a remarkable increase in the amount of cytoplasmic lipid stores as compared with that of C animals. Associated with progressive hyperglycemia between 8 and 16 weeks of age, uterine atrophy and continued lipid accumulation occurred. Both serum progesterone and estradiol levels were lower in D than C mice between 8 and 16 weeks of age. In addition, the uteri of D mice failed to accumulate as much 3H‐estradiol as C uteri at 16 weeks of age. These data demonstrate that changes in uterine structure that are attributable to depressed ovarian activity in diabetics underlie the reproductive failure in these animals. The temporal association between the onset of reproductive tract involution and the expressed hyperglycemic condition suggests a causal association between these events in the genetically diabetic C57BL/KsJ mouse.