bluuebunny/crossref_metadata_2025_split huggingface dataset:
Whole population cell kinetics and postnatal development of the mouse intestinal epithelium
Authors: Cheng Hazel , Bjerknes Matthew 
Published: February 2005

AbstractMeasurements of whole population cell kinetics of mouse intestinal epithelium during postnatal development are reported. Swiss albino mice aged 1, 2, 3, 4, 6, 8, 10, 12, 16, 19, 24, and 28 weeks were studied. Isolated epithelial preparations of jejunum and colon were used. Most kinetic parameters studied either increased or decreased with age to reach a steady level sometime after weaning. For example, before weaning about 30% of crypts were observed to be branching, while after weaning, the population of crypts that were branching decreased to adult levels of 5–10% in jejunum and 1–2% in colon. Thus, there was very active crypt formation before weaning, which likely continued into adult life but at a lower level. Villus formation appeared to be occurring in animals before weaning (i.e., 1–3 weeks), while it stopped with weaning, and thus the mean villus height increased to a plateau, which was constant with age after 4 weeks. In contrast, the mean villus width increased steadily with age. As the width of villi increased with age, the number of crypts assoiated with a villus also increased (presumably as a result of net crypt production in the adult). These measurements and many others (proportion of cells in S phase, number of cells/cm2, number of cells/villus, number of cells/crypt, etc.) are described.
Formation and perforation of closing plates in the chick embryo
Authors: Earle Waterman Robert 
Published: February 2005

AbstractThe morphology of the closing plates between adjacent pharyngeal arches was examined in chick embryos between stages 11 and 21 (HamburgerHamilton). Each closing plate is formed by apposition between the basal surfaces of portions of the pharyngeal pouch endoderm and the ectoderm of the overlying pharyngeal cleft. Initial contact between ectoderm and endoderm occurs at several small points which are separated by regions containing mesenchymal cells and extracellular material. Contact between the opposed epithelia is made by extension of cellular processes through the intervening basal laminae and extracellular space. Endodermal and ectodermal cells then interdigitate to create a cellular layer which rapidly thins. The interposed extracellular material is sequestered into small pools as cellular interdigitation proceeds. Perforations form through certain regions of closing plates 1–3 and persist during the stages studied. Small slit‐like depressions appear between cells of the closing plate just prior to perforation. The initial perforations enlarge until they are separated only by thin cellular strands. These strands presumably rupture, leaving small cellular accumulations which persist for a short time marking the junction between ectoderm and endoderm along the walls of adjacent pharyngeal arches. Clear evidence of cell degeneration is rare. These results suggest that cellular reorganization, rather than cell death, is a major mechanism of initial perforation.
Superior cervical ganglionectomy results in the loss of pineal concretions in the adult male gerbil (meriones unguiculatus)
Authors: Champney Thomas H. , Joshi Bhaskar N. , Vaughan Mary K. , Reiter Russell J. 
Published: February 2005

AbstractTwelve weeks after bilateral superior cervical ganglionectomy, the number of pineal concretions in adult male gerbils was drastically decreased irrespective of photoperiodic treatment. These findings present further evidence that pineal concretions may be related to the metabolic activity of the gland. It is suggested that the pineal concretions of the gerbil are associated, in a yet unknown way, to the metabolism of the gland and that an active pineal is essential to maintain the large number of concretions seen in the normal state.
Number and size of rat thyroid C cells: No effect of pinealectomy
Authors: McMillan P. J. , Heidbüchel U. , Vollrath L. 
Published: February 2005

AbstractA method for the estimation of the size and total number of calcitonin‐containing cells (C cells) in the rat thyroid gland has been devised. The total area, the number of C cells per unit area, and the areal fraction of C cells were determined for the C cell region using step serial sections. From these data it was estimated that from 0.3 × 106 to 1.0 × 106 C cells were evenly divided between the two thyroid lobes. Approximately 150 μm3 of cytoplasm were associated with each of these cells. In comparison with sham‐operated rats, pinealectomy had little effect on the number of C cells. In an experiment terminated in the summer, there was a statistically insignificant decrease 6 weeks postsurgery; no effect was seen at 12 weeks. On the other hand, a slight increase in the number of C cells was seen in January, 12 weeks postsurgery. The volume of cytoplasm per cell was not altered by pinealectomy.
Migration of macrophages from the marginal zone to germinal centers in the spleen of mice
Authors: Kotani Masahiko , Matsuno Kenjiro , Miyakawa Kazuhisa , Ezaki Taichi , Hayama Takeshi , Ekino Shigeo 
Published: February 2005

AbstractHistological observations of the mouse spleen were carried out at different times after intravenous carbon injection. Large carbon‐laden macrophages appeared in great numbers in the marginal zone soon after injection. They came together favorably around the germinal centers. Possible migration of these cells toward the germinal centers diffusely from the periphery of the white pulp or through the periarterial lymphoid sheath was suggested. These macrophages entered the germinal centers on a large scale and clustered for a long period–at least 180 days. Since the same type of macrophages were observed persistently in the marginal zone, it was thought that some of them might arise from the blood stream. Possible migration of these cells from the marginal zone toward the germinal centers was also persistently observed.A second type of much smaller carbon‐laden macrophages was seen in the white pulp. However, they never showed any favorable localization in the germinal centers as did large carbon‐laden macrophages.
Reduced number of brain cells in so‐called neural overgrowth
Authors: Desmond Mary E. 
Published: February 2005

AbstractPatten described as neural overgrowth a folding of brain tissue into the ventricles in abnormal human embryos. Intubation of chick embryo brains releases cerebrospinal fluid pressure resulting in a similar folding. These folded brains have 2.5 times less tissue volume than control embryos of identical stage. This study shows, with total DNA measurements, that brain cell number is 50% less in folded brains (intubated embryos) as compared to control brain of identical staged embryos.
Benzo(a)pyrene inhibits ovulation in C57BL/6N mice
Authors: Swartz William J. , Mattison Donald R. 
Published: February 2005

AbstractSuccessful female reproductive function requires follicle growth, ovulation, and formation of the corpus luteum. Treatment of C57BL/6N mice with a single intraperitoneal injection of benzo(a)pyrene in doses ranging from 1 to 500 mg/kg produced a dose‐ and time‐dependent decreaśe in the number of corpora lutea. This effect on the number of corpora lutea is most pronounced at 1 week after treatment, with a threshold of about 1 mg/kg, and an ED50 of 1.6 mg/kg. By 2 weeks after treatment partial recovery of follicle growth and ovulation occurred, as indicated by an increase in the ED50 to 20 mg/kg. Complete recovery of normal corpora lutea number occurs in mice treated with less than 100 mg/kg by 3 weeks after treatment, with little change in the ED50 noted between 3 and 4 weeks posttreatment, 78 mg/kg at both times. Mice treated with 100 or 500 mg/kg did not recover normal corpora lutea number over the course of this experiment. These data indicate that acute exposure to benzo(a)pyrene, and perhaps other polycyclic aromatic hydrocarbons, may have a transient adverse effect on follicle growth, ovulation, or formation of corpora lutea. A consequence of this effect, transient infertility, has been observed previously when exploring the effect of polycyclic aromatic hydrocarbons on murine reproduction.
The superficial sylvian vein in humans: With special reference to its termination
Authors: Bisaria Krishna Kumar 
Published: February 2005

AbstractA study of the termination of the superficial middle cerebral vein in 140 human specimens revealed that in 80 cranial cavities (51.1%) the vein drained into both the sphenoparietal sinuses, in nine cranial cavities (6.4%) into the sphenoparietal and cavernous sinuses, and in 19 cranial cavities (13.6%) into the sphenoparietal sinuses and middle meningeal veins. In 20 cranial cavities (14.3%) the vein drained into the cavernous sinuses alone and in eight cranial cavities (5.7%) it drained into the cavernous sinuses and middle meningeal veins. In one cranial cavity (0.71%) it drained into the vein in the foramen lacerum and the sphenoparietal sinus, in one cranial cavity (0.71%) into the sphenoparietal sinus and the superior petrosal sinus, in one cranial cavity (0.71%) into the middle meningeal veins on either side, and in another cranial cavity (0.71%) into the superior sagittal sinus, a finding which has not been reported in the past. The presence of an uncal vein draining the medial surface of the temporal lobe was observed occasionally (5.7%) in this study. A part of the superficial middle cerebral vein and sphenoparietal sinus in the form of a vein running a short course between the two layers of the lateral wall of the cavernous sinus is an observation previously not reported. This should be of value to neurosurgeons in the approach to the internal carotid artery through Parkinson's triangle.
Canalicular communication in the cortices of human long bones
Authors: Curtis Todd A. , Ashrafi Shahid H. , Weber Dennis F. 
Published: February 2005

AbstractA scanning electron microscopic (SEM) cast method that has been utilized to examine the internal structure of dentine was modified to examine canalicular communications in the cortices of a human femur and ulna. Although some preparations in which all of the matrix was removed were examined, etched preparations were found to be the most informative. Casts of lacunae and canaliculi along with the underlying matrix could be visualized in these preparations. In the femur, whose cortex exhibited a typical lamellar pattern, canalicular communication was seen between first and second generation osteons and occasionally between osteons and interstitial regions. The interstitial regions in the ulna appeared to be primarily woven rather than lamellar bone. Extensive communication between the outermost lacunae of osteons and interstitial regions was observed in the ulna.
Postnatal enlargement of human tracheobronchial airways and implications for particle deposition
Authors: Phalen Robert F. , Oldham Michael J. , Beaucage Christine B. , Crocker T. Timothy , Mortensen Jd 
Published: February 2005

AbstractIn support of predictions for inhaled particle deposition, morphometric measurements were taken on 20 replica airway casts of people aged 11 days to 21 years. Measurements of right upper lobe airway lengths, diameters, and branching angles were made such that a growth model suitable as input to predictive equations for particle deposition efficiency was obtained. The tracheobronchial airways growth was describable by linear regressions on body length. The length‐to‐diameter ratio of growing airways did not change in any simple way as a function of airway generation. Airflow rates for a given state of physical activity for various ages were found from previously published data to be describable by linear regressions on body mass. Three states of physical exertion–low activity, light exertion, and heavy exertion–were used for modeling purposes. The computed particle deposition efficiencies indicate that under most circumstances smaller (younger) people will have greater tracheobronchial deposition efficiencies than larger (older) people. For example, tracheobronchial dose on a per kilogram body mass basis for 5‐μmdiameter particles may be more than 6 times higher in the resting newborn than in the resting adult assuming equivalent deposition efficiencies above the larynx.
Structure of the sinus‐lining cells in the popliteal lymph node of the rabbit
Authors: Compton Carolyn C. , Raviola Elio 
Published: February 2005

AbstractThe structure of the sinus walls in the popliteal lymph node of the rabbit was studied with the electron microscope. In the marginal sinus, the endothelial cells are connected by gap junctions, puncta adherentia, and surface specializations characterized by focal approximation of the adjoining membranes without fusion. They possess large numbers of simple and compound uncoated invaginations of the plasma membrane that are closed by a diaphragm with a central thickening. The tissue strands that straddle the lumen of the sinus consist of a fibrous core containing both collagen and elastic fibers, surrounded by endothelial cell identical to those composing the outer sinus wall. Cortical sinuses that run independently of the trabeculae were identified by exploiting the fact that their endothelial cells accumulate lymph‐borne ferritin, and their lumen is outlined by horseradish perox‐idase administered intravenously. They are lined by a flattened, continuous endothelium and lack luminal strands. The walls of the medullary sinuses consist of endothelial cells and macrophages. The endothelial cells are interconnected by specialized junctions and contain fewer plasmalemmal vesicles than in the cortex; furthermore, dense granules are present in their cytoplasm. Macrophages adhere to the surface of the endothelial cells; typically, none of the junctional specializations that characterize the interface between endothelial cells connect endothelial cells to macrophages. However, at points along the contact region with the endothelium, the plasmalemma of the macrophage is decorated by an attachment plaque of fluffy cytoplasmic material. Sinus endothelial cells slowly accumulate lymph‐borne ferritin like vascular endothelial cells elsewhere in the body, whereas macrophages contain both ferritin and engulfed erythrocytes.
The presence of lymphatic stomata in the ovarian bursa of the golden hamster
Authors: Shinohara Harumichi , Nakatani Toshio , Matsuda Takeshi 
Published: February 2005

AbstractThe histology and function of the lymphatic system in the ovarian bursa of the golden hamster were examined at each day of the estrous cycle. The lymphatic passage from the ovarian bursa to a para‐aortic lymph node was stained black by india ink injected into the bursal cavity. This suggests that bursal fluid drains from the cavity via lymphatic vessels. Lymphatic stomata connecting the bursal cavity with the lymphatic lumen were consistently present throughout the cycle. However, the stomata were more frequently observed in the bursae on day 1 than on day 4 of the cycle. Also, they were more frequently observed in the bursae injected with 5 μl of chick erythrocytes than in the contralateral (not injected) bursa in hamsters on day 4 of the cycle. These results suggest that the stomata are openings the patency of which varies in response to changes in the bursal cavity. There were regions where the lymphatic lumen was separated from the bursal cavity only by lymphatic lumen was separated from the bursal cavity only by lymphatic endothelial cells. These regions were present throughout the estrous cycle. They may be patent stomata; dehiscence of junctions between the endothelial cells may give rise to stomata or widen the stomata orifices that are already present.
Cellular and subcellular colocalization of nerve growth factor and epidermal growth factor in mouse submandibular glands
Authors: Watson Ann Y. , Anderson Jacqueline K. , Siminoski Kerry , Mole John E. , Murphy Richard A. 
Published: February 2005

AbstractImmunocytochemical methods have been used to compare the cellular and subcellular distribution of nerve growth factor (NGF) and epidermal growth factor (EGF) in mouse submandibular glands. Rabbit antisera raised against purified proteins were characterized by immunoblot methods and were used to stain sections of salivary glands embedded in plastic. For light microscopy, antibodies were visualized by indirect immunofluorescence. For electron microscopy, thin sections were treated simultaneously with IgG against NGF and EGF coupled to colloidal gold particles of different size. Data indicate that NGF and EGF are present in all granular convoluted tubule cells and in no other cell type within the salivary gland. Ultrastructural analyses indicate that NGF and EGF are evenly distributed together within mature secretory granules, although a population of small granules was identified that is not immunoreactive for either protein. Taken together, the data suggest that granular convoluted tubule cells are homogeneous in the production and storage of NGF and EGF.
Immunochemical localization of vitamin D‐dependent calcium‐binding protein in mouse placenta and yolk sac
Authors: Bruns M. Elizabeth H. , Kleeman Ellen , Mills Stacey E. , Bruns David E. , Herr John C. 
Published: February 2005

AbstractA 10,000‐dalton calcium‐binding protein (10‐kd CaBP) has been described in the placentae and yolk sacs of rats and mice. This protein is similar or identical to vitamin D‐dependent intestinal CaBP and these proteins have been implicated in the molecular mechanisms of intestinal calcium absorption and transplacental calcium transport. Using an antiserum to the purified 10‐kd rat intestinal CaBP, the localization of CaBP in the 16–17‐day mouse yolk sac and placenta was studied immunocytochemically with peroxidase‐antiperoxidase labelling and quantified by radial immunodifussion. A high concentration of immunolabelling was observed in the endodermal cells of the intraplacental yolk sac lining the sinuses of Duval. The columnar endodermal cells lining one side of the endodermal sinuses adjacent to fetal vessels contained most of the immunoreactive label. Quantitation by radial immunodiffusion demonstrated a 5.5‐fold higher concentration of CaBP in the portion of the placenta containing most of the intraplacental yolk sac than in the maternal half of the placenta. This demonstration of a 10‐kd CaBP within the intraplacental yolk sac suggests this protein functions to facilitate placental calcium transport and is the first study which directly supports the hypothesis of a functional role for the sinuses of Duval in calcium transport.
Mitochondrial morphometrics of histochemically identified human extraocular muscle fibers
Authors: Carry Michael R. , Ringel Steven P. , Starcevich Jill M. 
Published: February 2005

AbstractThree fiber types—coarse, granular, and fine—were readily identified in histochemical cryostat sections of human extraocular muscle (EOM). The cryostat retrieval method was utilized to identify these three fiber types in serial electron microscopic thin sections. Using morphometric techniques, five mitochondrial variables (mitochondrial volume fraction, mitochondrial profile size, mitochondrial profile density, and clusters of two or of three or more mitochondrial profiles) were determined for a total of 162 histochemically identified fibers from two regions (orbital and global zones) from six EOMs. Coarse fibers had numerous large‐sized mitochondrial profiles, often occurring in clusters. Granular fibers had fewer and smaller‐sized profiles scattered across the fiber. Fine fibers had the most numerous, but smallest‐sized mitochondrial profiles. Despite significant differences in group (fiber types) means for the mitochondrial variables, no single variable was sufficient for separating fiber types into distinct populations. Although a scattergram plot of two variables was sufficient to separate orbital zone fibers, a computer‐generated, multivariate discriminant analysis was needed to separate the global zone fibers into distinct populations. These results will aid future studies on normal and pathological human EOM by providing a morphometric basis for identifying fiber types in the orbital and global zones.
Incorporation of 3H‐fucose and the secretion of glycoproteins in the coagulating gland of the mouse
Authors: Samuel Lynn H. , Flickinger Charles J. 
Published: February 2005

AbstractThe coagulating gland of rodents, which is part of the prostatic complex, secretes components of semen. Although possessing some ultrastructural features of other exocrine glands, the mechanism of secretion by these cells has been problematic. In the present study the pathway, kinetics, and mode of secretion in the coagulating gland of the mouse were studied by light and electron microscope autoradiography at intervals between 10 minutes and 3 hours after injection of 3H‐fucose. The majority of silver grains overlay the Golgi apparatus at the initial interval, but in addition, more than a third of the grains were associated with extremely distended cisternae of the rough endoplasmic reticulum. At later intervals, radioactivity of the Golgi apparatus and the endoplasmic reticulum declined, while labeling of secretory granules increased greatly. Luminal contents became labeled 1 hour after administration of precursor. The results indicate that the pathway for secretion of glycoproteins proceeds through the Golgi apparatus to secretory granules and the glandular lumen, as in many other cells. In particular, heavy labeling of secretory granules at later intervals indicates that merocrine secretion is the most likely mechanism in the coagulating gland. However, the unusual observation that a significant proportion of grains overlay the rough endoplasmic reticulum at the initial interval raises the possibility that some fucose is incorporated into glycoproteins in the endoplasmic reticulum, as has been reported for other cell types with similarly configured endoplasmic reticulum.
Concomitant analysis of osteoblastlike cell migration and proliferation on a serum‐enriched growth surface
Authors: Zuk Anna , Wezeman Frederick H. 
Published: February 2005

AbstractOsteoblastlike cell migration and accompanying proliferation on a growth surface precoated with fetal calf serum (FCS) was quantified using a modification of the chemotactic model of Alessandri et al. (1983) and autoradiography. Culture dishes were precoated with 1%, 10%, or 100% FCS and were overlaid with agar. Three‐millimeter‐diameter wells were cut and first‐passage osteoblastlike cells in serum‐free medium were seeded into the wells. At 12 and 48 hours, outward migration was quantified by measuring (1) the distance osteoblastlike cells had migrated peripheral to the well margin, and (2) the number of osteoblast‐like cells peripheral to the well margin. The data indicated that the migration of osteoblast‐like cells was related to time and FCS concentration. More cells migrated a further distance at 48 hours than at 12 hours. In addition, with greater FCS concentrations, osteoblastlike cell migration increased; 3H‐thymidine pulse labelling showed no incorporation of label into osteoblastlike cells at 12 hours. However, pulse labelling after 48 hours demonstrated that a small number of nuclei peripheral to the well margin were labelled. The data suggest that proliferation contributes negligibly to the population of osteoblastlike cells peripheral to the well margin. The appearance of osteoblastlike cells peripheral to the well margin is due primarily to migration.