bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lifelong moderate running training increases the incidence and severity of osteoarthritis in the knee joint of C57BL mice
Authors: Lapveteläinen T. , Nevalainen T. , Parkkinen J. J. , Arokoski J. , Kiraly K. , Hyttinen M. , Halonen P. , Helminen H. J. 
Published: February 2005

AbstractBackground: Inbred C57BL made mice express a high incidence of spontaneous osteoarthritis of the knee joint at the age of 18 months. We used this strain of mice to find out the effects of life‐long, moderate running exercise on the health of articular cartilage and the incidence of osteoarthritis.Methods: Male mice (294) were divided into controls and runners. The runners were trained daily between 2 and 18 months of age. The speed was 13.3 m/min and the distance on a flatbelt treadmill was 1,000 m/day. The mice were sacrificed at the ages of 2, 6, 10, 14, and 18 months. The Knee joints were sectioned in frontal direction and the osteoarthritic changes were graded using a conventional light microscope. The reproducibility of the grading method was tested by calculating extended k‐coefficient for the results of six researchers.Results: The incidence of osteoarthritis at the age of 18 months increased from 72% in controls to 88% in runners in the medial tibial condyles (P<0.05), and from 80 to 96% in the lateral tibial condyles (P < 0.001). The incidence of the most severe osteoarthritic changes rose from 16% in controls to 38% in runners in the medial tibial condyles, and from 4 to 36% in the lateral tibial condyles.Conclusion: According to our results, the moderate, long‐lasting running exercise accelerates the development of osteoarthritis in the knee joints of C57BL mice. © 1995 Wiley‐Liss, Inc.
Regeneration pattern of cardiac and skeletal muscle after transplantation into a skeletal muscle bed in rats
Authors: Gulati Adarsh K. 
Published: February 2005

AbstractBackground: The ability of skeletal muscle to regenerate after injury is well established. In contrast, cardiac muscle is incapable of regeneration and recovery after injury. The aim of the present study was to evaluate and compare the regeneration pattern of cardiac and skeletal muscle after transplantation into a skeletal muscle bed in rats.Methods: The following group of transplants were performed at the site prepared by removing the host extensor digitorum longus (EDL) muscle. The first group consisted of cardiac muscle transplanted as one piece or after mincing into 1‐mm pieces. The second group included cotransplants of cardiac and skeletal muscle minces that were intermixed. Entire EDL muscle or minced EDL muscle were also transplanted for comparison. Rats were sacrificed 3–30 days after transplantation for morphological analysis.Results: The results demonstrated that skeletal muscle transplants underwent rapid regeneration, and by 30 days the entire muscle was filled with regenerated myofibers. In transplants of cardiac muscle significant inflammation, myocardial degeneration and necrosis were observed. In spite of the necrosis and fibrosis, the presence of a few regenerated myotubes in the outer region was observed. In cardiac and skeletal muscle cotransplants, the inflammation was restricted to cardiac tissue; however, by 30 days the entire contransplant was filled with regenerated myotubes and myofibers.Conclusions: These results show that skeletal muscle is capable of growth, regeneration, and integration with the cardiac muscle after cotransplantation. Combination of skeletal and cardiac muscle may prove useful in defining the cellular processes necessary for enhancing cardiac repair after injury. © 1995 Wiley‐Liss, Inc.
Medullary projections to the vagus nerve and posterolateral hypothalamus
Authors: Hardy S. G. Patrick 
Published: February 2005

AbstractBackground: Vagal visceromotor reflexes are dependent upon reciprocal neural connections existing between the medulla and the hypothalamus. Medullohypothalamic neurons may provide feedback cues to the hypothalamus regarding the activity of vagal motor neurons. As yet, however, studies investigating the spatial relationships between medullohypothalamic neurons and vagal motor neurons have not been performed.Methods: A variety of retrogradely transported tracers were used for the purpose of mapping the relative locations of medullovagal and medullohypothalamic neurons. Tracers were injected into the cervical vagus nerve and/or the posterolateral hypothalamus, and subsequently the retrogradely labeled medullary neurons were plotted.Results: Labeling of the two neuronal populations was primarily observed within the ventrolateral and dorsomedial medulla. Within the ventrolateral medulla, medullovagal neurons were found within the retrofacial nucleus and nucleus retroambiguus, whereas medullohypothalamic neurons were located subjacent to these nuclei. Within the dorsomedial medulla, labeling of the two neuronal populations was primarily limited to the vagal‐solitary complex. At this location medullovagal neurons were found within the dorsal vagal nucleus, whereas medullohypothalamic neurons were largely confined to the caudal aspect of the solitary nucleus.Conclusions: Because of the spatial proximity existing between medullovagal and medullohypothalamic neurons, it is suggested that functional interrelationships may exist between these two neuronal populations. Specifically, it is suggested that the medullohypothalamic neurons identified in this study may support vagal‐related functions by providing feedback cues to the posterolateral hypothalamus. © 1995 Wiley‐Liss, Inc.
Metamorphic shortening of the alimentary tract in anuran larvae (Rana catesbeiana)
Authors: Pretty Robert , Naitoh Tomio , Wassersug Richard J. 
Published: February 2005

AbstractBackground: The premetamorphic alimentary tract in anurans can be more than 10 times a tadpole's body length but then dramatically shortens to a third or less of that length by the end of metamorphosis. Although there have been many studies on histological changes in the anuran gut with metamorphosis, the broader question of where the major shortening occurs has not been previously addressed. This topic is investigated here.Methods: We began our study by labeling intestinal coils in situ in preserved Rana catesbeiana tadpoles and then uncoiling their intestines, locating, and measuring the labeled points. This allowed us to map the coiled gut of the tadpole, such that the distance along the oral‐anal axis could be determined by simply counting coils. We next implanted markers into the intestinal coils of live R. catesbeiana tadpoles at five known locations along the oral‐anal axis, established from the prior mapping. The tadpoles were then induced to metamorphose by immersion in thyroid hormone. After the gut had shortened to a third of its premetamorphic length, the positions of the implanted markers were determined through dissection.Results: Relative distances between the marked points did not change when the gut shortened.Conclusions: The results indicate that during metamorphosis the intestine shortens uniformly along its length and not preferentially from one region or another. Although metamorphosis was artificially induced, the shortening that we observed matches that occurring during natural metamorphosis. © 1995 Wiley‐Liss, Inc.
Differences in distribution of myofiber types between the supraspinatus and infraspinatus muscles of sheep
Authors: Suzuki Atsushi 
Published: February 2005

AbstractBackground: The m. supraspinatus stabilizes the shoulder joint to bear the body weight, and the m. infraspinatus assists in extension and flexion of the joint in sheep. Postural muscles have many SO myofibers, whereas locomotory muscles have numerous fast‐twitch myofibers. In sheep the distribution of myofiber types within the two muscles, necessary for a better understanding of postural function, remains to be clarified.Methods: Muscle samples were removed from the whole transverse sections of the dorsal, middle, and ventral compartments of the m. supraspinatus and m. infraspinatus of sheep. Myofibers were classified into FG, FOG, SO‐1, and SO‐2 myofibers by histochemical methods.Results: The distribution of SO myofibers changed more greatly in the m. supraspinatus (15.0–99.1%) than in the m. infraspinatus (24.5–62.3%). SO myofibers were concentrated markedly in the caudal and deep regions near the spine and fossa of the scapula in the m. supraspinatus and distributed more in the medial part than in the lateral part in the m. infraspinatus. Such changes were caused by increases in percentage of SO‐2 myofibers and not SO‐1 myofibers. The craniolateral regions of the m. supraspinatus and the caudolateral regions of the m. infraspinatus had many fast‐twitch (FOG plus FG) myofibers suited for rapid extension and flexion of the shoulder joint.Conclusions: The m. supraspinatus has the compartmentalized, deep, and caudal regions occupied by SO myofibers, which seem to be specialized for maintenance of the joint extension. The medial region of the m. infraspinatus may assist in the joint stabilization. © 1995 Wiley‐Liss, Inc.
Sources of subcortical afferents to the macaque's dorsal lateral geniculate nucleus
Authors: Wilson James R. , Hendrickson Anita E. , Sherk Helen , Tigges Johannes 
Published: February 2005

AbstractBackground: The dorsal lateral geniculate nucleus (dLGN) is the thalamic region responsible for transmitting retina signals to cortex. Brainstem pathways to this nucleus have been described in several species and are believed to control the retinocortical pathway depending on the state of the animal (awake, asleep, drowsy, etc.). The purpose of this study was to determine all of the subcortical sources of afferents to the dLGN in a higher primate, the macaque monkey, whose visual system is similar to that of humans.Methods: Injections of horseradish peroxidase (HRP), with or without conjugation to wheat germ agglutinin, were made into the dLGNs of seven macaque monkeys, followed by perfusion, brain sectioning, and analyses of neurons in the brainstem, thalamus, and hypothalamus that contained the retrogradely transported marker.Results: The reticular nucleus of the thalamus, pedunculopontine nucleus, parabigeminal nucleus, pretectal nucleus of the optic tract, superior colliculus, dorsal raphe nucleus, and tuberomammillary region of the hypothalamus contained many retrogradely labeled neurons ipsilateral to the injections. In the contralateral brainstem, HRP‐labeled cells were found only in the pedunculopontine nucleus, nucleus of the optic tract, and dorsal raphe nucleus. The number of labeled neurons on the contralateral side was about one‐half of that in corresponding ipsilateral nuclei. The locus coeruleus contained no labeled neurons in four of the macaques that had injections limited to the dLGN.Conclusion: There are seven subcortical regions that send afferents to the dLGNs of macaque monkeys. Except for the locus coeruleus, these are the same as observed for other species, such as the cat and rat, and indicate the possible sources of subcortical control over the dLGNs of humans. © 1995 Wiley‐Liss, Inc.
Development and degeneration of the arterial system in the mesonephros and metanephros of chicken embryos
Authors: Carretero Ana , Ditrich Hans , Pérez‐Aparicio F. Javier , Splechtna Heinz , Ruberte Jesus 
Published: February 2005

AbstractBackground: The general morphology of the mesonephric and metanephric arteries in chicken embryos has already been described previously. Moreover, the general basis of glomerulogenesis has also been established. However, the degeneration of the mesonephric vascular system, and especially glomerular degeneration, have not been well established yet. Also the morpology of the metanephric angiogenic buds has not been studied yet.Methods: Scanning electron microscopy of vascular corrosion casts and critical point dried specimens as well as light microscopy of serially sectioned material has been used in this study. Mesonephric degeneration coincides in time with metanephros growth and maturation in the developmental stages of chicken embryos chosen for this investigation (7.5, 9, 11, and 14 days of incubation).Results: The arterial system of the mesonephros in embryonic chicken is similar to that of the anuran kidney, as described in the literature. The morphology of the degenerating mesonephric glomeruli shows that the glomerular capillaries are more thick, tortuous, and numerous than those in normal glomeruli. The podocytes also show degeneration. The arterial system of the metanephros grows directly from the aorta and from the mesonephric arterial system. During these stages of rapid growth, the metanephros shows angiogenic buds. These angiogenic buds can be either pointed or round blind endings.Conclusions: The distribution and topography of the mesonephric and metanephric arteries is in general accordance with the literature. The process of glomerular degeneration in the mesonephros seems similar to glomerular senescence in man but is different from that of the aged rat glomeruli. The round angiogenic buds observed in the metanephros resemble tumoral angiogenic buds in some aspects. However, both angiogenesis and the degenerative phenomena are part of the normal developmental process. Consequently, the involved mechanisms are probably under sole genetic control. The system studied here offers therefore the possibility to study vascular growth and degeneration on the same model in physiological conditions without application of vasoactive or pathological agents. © 1995 Wiley‐Liss, Inc.
Morphological evidence of exocrine function in coagulating gland renin of mouse strain C57BL/6
Authors: Kon Yasuhiro , Endoh Daiji , Murakami Kazuo , Yamashita Tadashi , Watanabe Tomomasa , Hashimoto Yoshiharu 
Published: February 2005

AbstractBackground: Renin is classically secreted from juxtaglomerular cells of the kidney by endocrine or paracrine mechanisms. In a previous report, intense renin immunoreactivity was observed in the coagulating gland (CG), a new source for renin in mice. In the present study, immunoelectron microscopical analysis for renin was carried out to clarify the secretory site of CGs.Methods: Five adult male C57BL/6 mice were used in this study. The CGs were fixed with an ice‐cold 2% glutaraldehyde and 2% paraformaldehyde mixture and embedded in Lowicryl K4M. Ultrathin sections were treated with antimouse renin antiserum and colloidal gold (15 nm)‐labeled protein A complex.Results: In immunoelectron microscopical observation, renin was first detected at the Golgi vacuoles just budding from the lamellae, although it was not demonstrated in all Golgi vacuoles. In the production series of exocrine granules, renin immunoreactivity was observed in some granules that were distributed in the supranuclear region. Both renin‐positive and negative exocrine granules were secreted from the apical cell membrane by exocytosis. The lysosomal granules also showed stronger renin immunoreactivity and contained homogeneous or heterogeneous materials. In the supranuclear region, it was observed that exocrine granules were fused with irregular lysosomal granules. At the apical region, such lysosomal granules were closely associated with cell membrane. At the basolateral region, immunoreactivity for renin was localized in electron dense granules.Conclusions: These results suggest that part of the renin in the CGs is released by exocrine secretion into the genital tract. © 1995 Wiley‐Liss, Inc.
Atrioventricular valves of the mouse: III. Collagenous skeleton and myotendinous junction
Authors: Icardo José M. , Colvee Elvira 
Published: February 2005

AbstractBackground: The leaflet tissue of the mouse atrioventricular (AV) valves contains a system of wavy collagen bundles that organize like tendons, orientate along lines of tension, and constitute an essential component of the valve tissue. The organization of these bundles is different in the two AV valves, reflecting differences in the anatomy of the entire valvular complex. Further insights into this kind of organization are needed to gain a complete understanding of the functional anatomy of the mouse AV valves.Methods: The endocardial covering of the mouse AV valves (from 21 days to 1 year of age) was eliminated by the sonication or the maceration method. This allowed us to study in situ the organization of the collagenous valve skeleton, as well as the structure of the myotendinous junction.Results: The leaflets of the two AV valves are formed by a fibrous layer (on the ventricular side) and a spongy layer (on the atrial side). The fibrosa is formed by undulating collagen bundles that organize and orientate differently on the right and left sides. The spongiosa is formed, on both sides, by a loose network of thin collagen fibers with no apparent orientation. Myocardial cells in the papillary muscles of the tricuspid valve are elongated and show cone‐shaped tips. Collagen fibers attach to the myocyte surface. Collagen struts and thin septa can also be recognized. On the other hand, the collagenous components of the mitral leaflets attach tangentially to the mitral papillary muscles. On the two sides, the myocytes appear to be ensheathed in a layer of collagenous tissue. The sheaths are formed by circularly arranged fibers and appear to be tightly interconnected.Conclusions: The differences in the collagenous organization between the two AV valves reflect differences in the gross anatomy of the valves. The attachment of collagen to the papillary myocytes in the tricuspid valve resembles that of a typical myotendinous junction. However, the collagenmuscle junction in the mitral valve is more similar to the structure of a pennate muscle.The collagen matrix of the heart has been divided into endomysial, perimysial, and epimysial components. The presence of sheaths housing individual myocytes and capillaries, struts, and thin septa, corresponds to the endomysium. The absence of perimysial septa, which aggregate myocytes into groups, is striking, but this may just be a species difference. The appropriateness of the term epimysium, as applied to the heart, is discussed. © 1995 Wiley‐Liss, Inc.
Dendritic cells in the bursal follicles and germinal centers of the chicken's caecal tonsil express vimentin but not desmin
Authors: Oláh I. , Glick B. 
Published: February 2005

AbstractBackground: Immunohistochemical studies with anti‐vimentin and anti‐desmin monoclonal antibodies were designed to determine the origin of bursal secretory dendritic cells (SDC) and follicular dendritic cells.Methods: The binding sites of anti‐vimentin, anti‐desmin, and antichicken‐IgG specific monoclonal antibodies were visualized with a biotinylated anti‐mouse‐IgG, ABC Elite kit, and 4‐chloronaphthol. Cells were double stained (anti‐vimentin and rabbit anti‐chicken‐IgG Fc) to determine if the vimentin positive cells possessed surface IgG.Results: Vimentin positive cells were observed in the cortex and medulla of the bursa and germinal center and lymphoepithelial compartment of the caecal tonsil. The mesenchymal reticular cell, the basic supporting cell of the germinal center, was stained prominently by anti‐vimentin and anti‐desmin. Both antibodies stained the bursal cortex but only anti‐vimentin bound the bursal secretory dendritic cell of the medulla. In addition to being vimentin positive and desmin negative, the bursal secretory dendritic cell possessed and the follicular dendritic cell appeared to possess IgG on their surfaces. In all the observations, B‐cells were vimentin negative.Conclusion: These studies suggest that follicular dendritic cells and mesenchymal reticular cells in the caecal tonsil's germinal centers may be functionally different cell populations while the bursal secretory dendritic cell and follicular dendritic cell of the caecal tonsil may have a common origin. © 1995 Wiley‐Liss, Inc.
The effects of high dose of parathyroid hormone on fetal osteoclasts and their precursors in vivo: An ultrastructural‐cytochemical study
Authors: Isaki Hisayuki , Hanaoka Hideya 
Published: February 2005

AbstractBackground: It is not well known how the immediate precursors of osteoclast develop into osteoclasts in the fetus. This ultrastructural‐cytochemical study was designed to clarify the formation process of the osteoclasts and their increased activities in the fetal mouse limb buds after administration of high dose parathyroid hormone (PTH).Methods: Twenty‐four or forty‐eight hours after the high doses of PTH were injected into amniotic fluid of the pregnant C3H mice, the femoral limb buds of embryos were dissected out. Tartrate‐resistant acid phosphatase (TRAP) reactions were performed while preparing specimens for electron microscopy.Results: Both control and PTH‐given preosteoclasts and osteoclasts exhibited TRAP‐positivities in dense bodies and vesicles. As effects of PTH, a binucleated preosteoclast of tandem fashion was observed. More osteoclastic hyperactivities were observed in the diaphyseal bone marrow. An osteoclast with a large cytoplasm exhibited two sets of clear zones and ruffled borders. Some osteoclasts demonstrated prominent amoeboid figures, while other osteoclasts developed large cytoplasmic vacuoles, which contained pieces of calcified chondroid bars.Conclusions: Our results revealed the progression of maturation from young preosteoclasts to osteoclasts. An existence of a peculiar binucleated preosteoclasts suggested one of the processes for multinucleation of the osteoclast. Quite remarkable osteoclastic hyperactivities were obviously the effects of high dose PTH. Our results also indicated the endophagocytic ability of the osteoclast. How PTH affected the osteoclasts and their precursors in the diaphyseal bone marrow can be speculated. © 1995 Wiley‐Liss, Inc.
Morphological changes in the normal pattern of ventricular myoarchitecture in the developing human heart
Authors: Sanchez‐Quintana Damian , Garcia‐Martinez Virginio , Climent Vicente , Hurle Juan M. 
Published: February 2005

AbstractBackground: The aim of the present study was to describe the morphological changes in the normal pattern of ventricular myoarchitecture in the prenatal and adult human heart, to understand the three‐dimensional organization of the muscle fibers and their active functional role in valvular dynamics.Methods: We used dissection and histological techniques in 56 human hearts from fetuses and adults of both sexes.Results: In all hearts, the ventricular wall was arranged in three different layers: superficial (subepicardial), middle, and deep (subendocardial) myocardium. The superficial and deep layer are present in both ventricles, whereas the middle layer is found only in the left ventricle. Age‐related differences were noted in the pattern of myoarchitecture of the superficial layer, mainly in the fetal period, and especially in the right ventricle; however, the middle layer always shows a circumferential pattern, which is specially evident in elderly hearts. The ventricular fibers in the superficial and deep layers are anchored in the ventricular orifices.Conclusions: Our findings reveal that muscle fiber architecture showed age‐but not sex‐related differences. These variations may reflect a mechanism of adaptation of the heart to functional demands throughout life. © 1995 Wiley‐Liss, Inc.