bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functional combination of tapering profiles and overlapping arrangements in nonspanning skeletal muscle fibers terminating intrafascicularly
Authors: Hijikata Takao , Wakisaka Hitoshi , Niida Shumpei 
Published: February 2005

AbstractUsing digital image analysis and several anatomical methods, morphometric analysis of nonspanning fibers which had tapering profiles at their intrafascicular termination sites and represented overlapping arrangements within the fiber fascicles was performed in the rat rectus abdominis. Special emphasis was focused on dimensional relationships occurring between overlapping portions and tapering segments and sarcomere lengths in non‐ and overlapping portions. Nonspanning fibers were found to overlap each other for more than 40% of their length. In length, their overlapping portions generally corresponded to their tapering segments, which were also greater than 40% of the fiber length. In addition, despite the presence of overlapping linkages, nonspanning fibers maintained a fairly uniform length irrespective of their overlapping and non‐overlapping portions. Overlapping linkages in fibers without tapering profiles have a larger cross‐sectional area in the overlapping portion than in the non‐overlapping one, resulting in a phenomenon which will cause different sarcomere lengths between the two portions during fiber stretching. The present results suggest that tapering profiles in the overlapping portion ensure uniform sarcomere lengths within nonspanning fibers, thereby providing mechanical stability in each fiber. © 1993 Wiley‐Liss, Inc.
Stage‐specific detection of mRNA for the sperm antigen SP‐10 in human testes
Authors: Kurth Barbara E. , Wright Richard M. , Flickinger Charles J. , Herr John C. 
Published: February 2005

AbstractSP‐10 is a sperm‐specific, intra‐acrosomal protein that is considered to be a vaccine candidate for immunocontraception. In the present study, in situ hybridization with biotin and 35S labeled riboprobes was used to determine the pattern of SP‐10 mRNA expression in human testes. Both methods demonstrated SP‐10 mRNA primarily in round spermatids found in stages I, II, and III of the seminiferous cycle. Morphometric analysis of silver grains with the 35S‐labeled probe showed less SP‐10 mRNA in spermatids at stages IV, V, and VI than in previous stages, and rarely was label found in spermatogonia or spermatocytes. The expression of SP‐10 mRNA first appeared at stage I coincident with the appearance of the protein, which was shown previously to persist in the acrosomal matrix throughout spermiogenesis. The decrease in SP‐10 mRNA occurred when spermatids underwent polarization, nuclear condensation, and elongation. The appearance of SP‐10 mRNA in round spermatids suggest that increases in SP‐10 transcription or SP‐10 mRNA stability or both occur as spermatids develop from the Golgi phase to the cap phase. The subsequent decline of SP‐10 mRNA, despite the persistence of the SP‐10 protein in all spermatids, suggests that a decrease in SP‐10 transcription or an increase in mRNA degradation occurs when spermatids elongate. © 1993 Wiley‐Liss, Inc.
Localization of insulin‐like growth factor‐I‐like immunoreactivity in the reproductive tract of the vitellogenic female American alligator, Alligator mississippiensis
Authors: Cox Cathy , Guillette Louis J. 
Published: February 2005

AbstractInsulin‐like growth factor I (IGF‐I) is a 70 amino acid, mitogenic polypeptide, which, in mammals, acts through an endocrine, paracrine, and/or autocrine pathway to regulate growth and development. The primary goal of this study was to determine whether or not IGF‐I‐like immunoreactivity is present in the oviduct of the vitellogenic American alligator, Alligator mississippiensis, and if immunoreactivity patterns vary among the three functional oviducal regions: the albumen‐secreting tube region, the anterior, fiber‐secreting uterus, and the posterior, calcium‐secreting uterus. Immunolocalization of IGF‐I‐like immunoreactivity was accomplished using a polyclonal antihuman rabbit antiserum with an immunoperoxidase staining system. IGF‐I‐like immunoreactivity was detected in all three oviducal regions of the vitellogenic alligator. The presence of IGF‐I‐like immunoreactivity in the oviduct suggests this hormone could function in the growth and proliferation of the alligator oviduct. Furthermore, the presence of IGF‐I‐like immunoreactivity in the tubal glands, which secrete components of the egg white, suggests that growth factors such as IGF‐I may be synthesized by these glands and incorporated into the albumen during egg formation. © 1993 Wiley‐Liss, Inc.
Development of the ventriculoarterial segment of the human embryonic heart: A morphometrics study
Authors: Thurkow Erik W. , Wenink Arnold C. G. 
Published: February 2005

AbstractIn the literature, discussions continue on the question whether the distal portion of the cardiac outlet segment (ventriculoarterial portion, outflow tract of the embryonic heart) is subject to a shortening (absorption, retraction) during development. In 28 human embryos ranging from 4–42 mm crown‐rump length, stereological estimates of volume fractions and surface densities were used to calculate the diameter and the length of the distal outlet segment and their changes during development. A significant increase was found in the wall thickness of this segment, whereas its length remained about the same. An actual shortening was not found. It is concluded that the relative change in proportions is the cause of the disagreements. It is further concluded that there is still a mechanical role for the aorticopulmonary septum in maintaining the length of the outlet segment during growth of this region. © 1993 Wiley‐Liss, Inc.
Microinjection of antifibronectin antibodies in the chicken blastoderm: Inhibition of mesoblast cell migration but not of cell ingression at the primitive streak
Authors: Harrisson Fernand , Van Nassauw Luc , Van Hoof Johan , Foidart Jean‐Michel 
Published: February 2005

AbstractThe involvement of fibronectin in adhesion and migration of individual mesoblast cells during chicken gastrulation was examined after microinjection of functional and nonfunctional antifibronectin antibodies in the blastoderm during the period of rapid migration of mesoblast cells. The injection of affinity‐purified polyclonal antihuman fibronectin antibody (total IgG or Fab fragment) or of monoclonal antichicken cellular fibronectin caused a thickening of the primitive streak, which was composed of loosely connected cells. This effect was most evident at the level of Hensen's node, and very few mesoblast cells were observed migrating in the space between upper layer and deep layer. The obvious explanation of this effect was that the de‐epithelialization of upper layer cells persisted in the presence of antibodies, but ingressed cells failed to emigrate from the primitive streak. Immunostaining of microinjected antibodies showed binding to the basement membrane, to the cell surface of mesoblast cells that had migrated before microinjection occurred, and to the cell surface of deep layer cells. Cells that ingressed and detached in the course of reincubation of the embryo possessed little immunolabelling along their cell surface. The results suggest that the failure of ingressed cells to emigrate from the primitive streak and to form mesoblast was due (1) to alterations in adhesion between newly ingressed primitive streak cells, which had the ability to detach but possessed relatively little fibronecting along their cell surfaces and a small number of cell protrusions, and (2) probably to a lack of adhesion of detached cells to the basement membrane, which was blocked by the presence of antifibronectin antibodies. We conclude that the presence of fibronectin in the basement membrane is required for emigration of ingressed cells and migration of mesoblast cells to occur. Once migration has commenced, fibronectin is also deposited along the cell surface of migrating cells, a factor that may increase their mutual adhesion. © 1993 Wiley‐Liss, Inc.
Scanning and transmission electron microscopy and high resolution intravital video‐microscopy of capillaries in the mouse exocrine pancreas, with special emphasis on endothelial cells
Authors: Aharinejad S. , MacDonald I. C. , Schmidt E. E. , Böck P. , Hagen D. , Groom A. C. 
Published: February 2005

AbstractCapillaries in the mouse exocrine pancreas were studied by scanning electron microscopy of microvascular corrosion casts, transmission electron microscopy of tissue sections, and high resolution intravital video‐microscopy. Two types of capillaries were discerned by corrosion casting. The first type was rather straight, had a constant diameter of 5–6 μm, and its surface showed multiple circumferential furrows. The frequency of such constrictions was less in the second type, which was more undulated and had a diameter of 7–9 μm. In the second type, these constrictions defined bulged areas of the capillary cast. Corresponding tissue sections also showed two types of capillaries, fenestrated and non‐fenestrated capillaries. Microtubules were abundant in all capillary endothelial cells, whereas bundles of microfilaments were scarce. Microtubules were arranged along the long axis of endothelial cells as well as parallel to endothelial cell border regions. Endothelial cells were joined by intermediate junctions along cell borders running both circumferentially and longitudinally. Flow reversal in capillaries and spontaneous endothelial contractions were documented in vivo. Endothelial cells bulged into the lumen, either at their nuclear region or distant from it. Spontaneous contraction of pericytes was not observed. These results suggest that contraction of capillaries is carried out by endothelial cells, representing an autonomous flow regulatory device. Capillary contraction in exocrine pancreas may be influenced by blood‐borne agents, probably by those released in Langerhans islets. © 1993 Wiley‐Liss Inc.
Ultrastructural changes in the efferent duct and epididymis of men with obstructive infertility
Authors: Rajalakshmi M. , Ratna Kumar B. V. , Kapur M. M. , Pal P. C. 
Published: February 2005

AbstractUltrastructural changes in the efferent duct and in different regions of the epididymis in men with obstructive azoospermia were compared with corresponding tissues collected from men of proven fertility who underwent castration due to malignancy of the prostate. Major degenerative changes were seen in the efferent duct and the caput epididymidis of men with obstruction at the caput epididymidis which may have been induced by fluid pressure due to defective absorption of testicular fluid in the caput epididymidis. These degenerative changes included decrease in tubular and lumen diameter of the caput and the cauda epididymides, decrease in height of the stereocilia, reduction in‐rough endoplasmic reticulum and Golgi material, and presence of lipofuscin and osmiophilic dense bodies. The degenerative changes were less when the site of obstruction was in the cauda epididymidis since fluid reabsorption would continue to take place normally in the caput epididymidis. In men who had undergone vasoepididymostomy (VEA), the ejaculated spermatozoa showed a high percentage of morphological abnormalities which may have occurred due to adverse effects of long‐term obstruction on spermatogenesis. © 1993 Wiley‐Liss Inc.
Development of the adult endocrine pancreas during metamorphosis in the sea lamprey, Petromyzon marinus L. II. Electron microscopy and immunocytochemistry
Authors: Elliott W. M. , Youson J. H. 
Published: February 2005

AbstractThe development of the adult endocrine pancreas was followed throughout metamorphosis in the sea lamprey using electron microscopy and immunocytochemistry. It was discovered that the caudal pancreas develops from the larval extrahepatic common bile duct through the process of transdifferentiation (dedifferentiation/redifferentiation). Early in metamorphosis the bile duct epithelial cells possess large vacuoles, resembling autophagic vacuoles, containing recognizable cell material. There is a loss of the large bundles of intermediate filaments characteristic of the larval bile duct epithelium. These same cells are then seen to contain granules immunoreactive for insulin. Pancreatic islets develop within the base of the bile duct epithelium from these transdifferentiated cells and migrate into the surrounding connective tissue to form the caudal pancreas. The cranial pancreas was found to develop from the epithelia lining the developing adult diverticulum and anterior intestine in a similar fashion as those in the larva. The second cell type to appear in either portion of the developing pancreas is similar to the third cell type of the adult: cells immunoreactive for somatostatin do not appear until late in metamorphosis in either region. © 1993 Wiley‐Liss Inc.
Age changes in neuromuscular junctions of masseter muscle
Authors: Elkerdany M. K. , Fahim M. A. 
Published: February 2005

AbstractThere is little information regarding the relationship between aging and ensuing morphological changes in the neuromuscular junction (NMJ) of the masticatory muscle. The masseter of C57BL/6J male mice at three different ages (young adult, 6 months; mature adult, 12 months; and old, 30 months) was studied. Morphological measurements were taken from zinc iodide osmium stained NMJ. Camera lucida drawings were superimposed on a computer monitor via a video camera and traced using a digitizer. The data were treated statistically using multivariate analysis of variance (MANOVA). No difference was found between 6 and 12 months of age, but a significant decrease in morphological parameters in NMJ from 30‐month‐old animals was found when compared with mature adult animals. Nerve terminal areas, perimeters, longitudinal extent lengths, and fiber diameters were reduced by 24%, 21%, 15.5% and 23%, respectively. Nerve terminal branches and incidence of sprouts were significantly increased in older animals. Age changes in the NMJ morphology are probably associated with altered balance between degeneration and regeneration of nerve terminals. This view is supported by increased terminal sprouting in old mice which is indicative of the plasticity or remodelling of NMJ during aging. © 1993 Wiley‐Liss Inc.
Experimental study of the development of the truncus arteriosus of the chick embryo heart. I. Time of appearance
Authors: Garcia‐Peláez Isabel , Arteaga Manuel 
Published: February 2005

AbstractThe time of appearance of the truncus arteriosus was studied in the chick embryo using an in ovo labeling technique. Three hundred embryos at stages 13–18 of Hamburger and Hamilton were selectively labeled at the distal end of the heart tube, using gelatine‐india ink label; 122 of these embryos were reincubated and 111 of them reached stages 25–28. In these stages the final location of the label was determined. Only 95 of these embryos showed both a normal heart and a label located in it. The remaining embryos were discarded due to abnormal cardiac morphology or because the label was not found. Embryos labeled at stages 13–14 had label in the conus in 42.8% of the cases and in the boundary between the conus and the truncus arteriosus in 57.1% of the cases. Label placed at stages 15–16 was located in the conus in 6.1% of the cases, in the boundary between the conus and the truncus arteriosus in 44.8% of the cases, and in the truncus arteriosus in 48.9% of the cases. Finally, label placed at stages 17–18 was located in the boundary between the conus and the truncus arteriosus in 18.7% of the cases and in the truncus arteriosus in 81.2% of the cases. Our results permit us to conclude that the truncus arteriosus appears in the chick embryo as early as stages 15–16 of Hamburger and Hamilton (50–56 hours of incubation). © 1993 Wiley‐Liss, Inc.
Gross anatomy: An outdated subject or an essential part of a modern medical curriculum? Results of a questionnaire circulated to final‐year medical students
Authors: Pabst Reinhard 
Published: February 2005

AbstractFinal‐year undergraduate medical students were given a questionnaire on the gross anatomy curriculum they had experienced in their first year at medical school 5 years earlier. They were asked to evaluate the relevance of the dissection course, lectures and seminars in gross anatomy for clinical courses, clerkships, and everyday practical work on the ward. About two‐thirds of the students found the time spent on 10 different regions in anatomy to be adequate, and a considerable number of students would have liked even more details. The vast majority expressed a wish to repeat topographical anatomy during their clinical teaching. Furthermore, ∼75% of the students showed interest in short, specialized dissection courses during the clinical curriculum. Medical students just before graduation ranked gross anatomy with the dissection course and integrated clinical topics as a keystone for their clinical courses. The results of such surveys should be taken into consideration when discussing modification to teaching gross anatomy or arguing about a balanced dissection course. © 1993 Wiley‐Liss, Inc.
Isolated pancreatic islets of the rat: An immunohistochemical and morphometric study
Authors: El‐Naggar Mostafa M. , Elayat Ahmed A. , Ardawi M. Salleh M. , Tahir Mohammad 
Published: February 2005

AbstractAlthough there is a recent increase in the use of the isolated pancreatic islets of the rat in the transplantation and functional studies, there has been no detailed quantitative assessment on the size and cellular constituents of islets after the isolation procedure. The present work was undertaken to study the size classes of the isolated islets and the morphometry of their cellular populations.Islets of the rat pancreas were isolated by using the intraductal collagenase digestion technique, the most commonly used procedure for the isolation of pancreatic islets. Different endocrine cells of the isolated islets were stained by immunoperoxidase staining techniques. The distribution of the cellular constituents of the isolated islets was similar to that of the intact islets of the normal pancreas; A, D, and PP cells were peripherally arranged around the centrally located B cells. However, morphometric quantitative study showed that the percent volume and percent number of A, D, and PP cells of the isolated islets were lower than those of the corresponding intact ones. Further, the mean true diameter of the isolated islets was lower than that of the intact ones. These data indicate loss of islet cells during the process of isolation. Most of the lost cells were from the periphery of islets. This may provide an explanation for the incomplete metabolic control and recurrence of hyperglycemia encountered after isolated islet transplantation in the treatment of diabetes mellitus. It seems that further refinements of the isolation techniques are necessary to obtain islet tissue with total cellular integrity, before a complete success in transplantation could be achieved. © 1993 Wiley‐Liss, Inc.
Role of mesenchymal cells in the neovascularization of the rabbit phallus
Authors: Hara Kazuo , Doi Yoshiaki , Nagata Naoki , Furukawa Hiroshi , Sagara Tetsuya , Yamamoto Koji , Yokoyama Mitsuru , Yoshizuka Mitsuaki , Fujimoto Sunao 
Published: February 2005

AbstractThe neovascularization of the rabbit phallus at ages between prenatal days 15 and 21 was investigated by light‐ and electron microscopy, computer‐aided light microscopic reconstruction, and immunocytochemistry. The phalli are embedded by an abundance of mesenchymal cells, which are in contact with the neighboring ones or with the endothelial lining of growing capillaires. They often form solid cell cords that eventually make contact with the growing capillaries. The computer‐aided reconstruction of the serial light micrographs reveals that these cell cords are involved in connecting the adjacent capillaries. The incorporation of such mesenchymal cell projections into the endothelial lining, occasionally conjugated with simple attachement devices, is frequently observed by transmission and scanning electron microscopy. The contact areas between the mesenchymal and endothelial cells show immunoreactions of fibronectin.These results indicate the successive transformation of mesenchymal cells to endothelial cells of the growing capillaries. As endothelial cells of the growing capillaries show mitotic proliferation, such vasoformative mesenchymal cells seem to be involved in the acceleration of the neocapillarization of the rabbit phallus. Fibronectin actively produced in the mesenchymal cells may participate in their migration and the mechanical linkage with the endothelial cells. © 1994 Wiley‐Liss, Inc.
Intramembranous bone matrix is osteoinductive
Authors: Scott Caroline Kelly , Bain Steven Douglas , Hightower James Anderson 
Published: February 2005

AbstractAll known bone‐derived osteoinductive factors have been isolated from endochondral (EC) bones and all initiate bone induction via EC ossification. However, to date no attempt has been made to isolate comparable factors from bones which form initially and completely via intramembranous (IM) ossification. The purpose of this work was to isolate osteoinductive proteins from IM bones. To accomplish this, we extracted proteins from bovine frontal bone matrix (intramembranous origin) using methods previously described for endochondral (EC) bone matrix (i.e., femur). Bone powder (<1 mm) was decalcified and proteins extracted with 4 M guanidine hydrochloride. Ultrafiltration was used to isolate and concentrate a 10–100 kilodalton (kDa) fraction, upon which heparin‐Sepharose (HS) affinity chromatography was performed. HS‐binding (HS‐B) and non‐binding proteins (HS‐NB) were lyophilized with bovine type I collagen (Vitrogen) to form pellets which were implanted subcutaneously in rats. Radiology as well as brightfield, fluorescent, and polarizing microscopy were used to assess the formation of ectopic bone at the site of pellet implantation. In this report we demonstrate that a heparin‐Sepharose binding, osteoinductive factor can be extracted and partially purified from bovine intramembranous bone matrix. This factor has a different sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE) banding pattern than a comparable osteoinductive/chondroinductive factor isolated from EC bone. © 1994 Wiley‐Liss, Inc.
Stereological analysis of collagen and elastic fibers in the normal human dermis: Variability with age, sex, and body region
Authors: Vitellaro‐Zuccarello Laura , Cappelletti Silvia , Rossi Vera Dal Pozzo , Sari‐Gorla Mirella 
Published: February 2005

AbstractNormal human dermis has been analyzed using sterological methods to estimate the quantitative modifications of collagen and elastic fibers in relation to age, sex, and body region. Forty‐five skin biopsies from the trunk or the limbs of 26 males and 19 females of different age were fixed in glutaraldehyde and osmium tetroxide and embedded in epoxy resin. The relative volumes of collagen and elastic fibers were calculated by the point counting method on 1 μm semithin sections. Photographic sampling was performed on four consecutive dermis layers: the papillary layer and three consecutive layers of reticular dermis. The data were subjected to analysis of variance which showed that all the factors studied exert a significant influence on the relative amounts of collagen and elastic fibers. The fractional volume of collagen fibers is constant throughout all dermis layers analyzed and is always higher in females than in males, except for the second and third decades of life. Collagen fiber density increases with age in both sexes up to 30–40 years, when it starts decreasing. Both the relative volumes and the diameters of elastic fibers increase from papillary to deep reticular dermis. In reticular dermis of both sexes there is an increment of elastic fiber density in the first decade of life, followed by a drop particularly marked in males. After 20 years, the relative volume of elastic fibers displays a decreasing trend in females, whereas it increases in males, attaining the highest values beyond the 40s. © 1994 Wiley‐Liss, Inc.