bluuebunny/crossref_metadata_2025 huggingface dataset:
Subperiosteal lmplantation of octacalcium phosphate (OCP) stimulates both chondrogenesis and osteogenesis in the tibia, but only osteogenesis in the parietal bone of a rat
Authors: Sasano Yasuyuki , Kamakura Shinji , Nakamura Masanori , Suzuki Osamu , Mizoguchi Itaru , Akita Hirotoshi , Kagayama Manabu
Published: February 2005

Background: It is not known whether long bones and calvaria have distinct biological characteristics. Octacalcium phosphate (OCP), which is a precursor phase of the hydroxyapatite, has been reported to stimulate bone formation if implanted in the subperiosteal region of mouse calvaria. The present study was designed to investigate how the long bone and the calvarium respond to OCP implantation and to compare their biological characteristics.

Methods: The synthetic OCP was implanted into the subperiosteal region of rat tibiae and parietal bones being mixed with bovine type I collagen treated by pepsin (Atelocollagen). The biological response was examined histologically and immunohistochemically for collagen matrix phenotypes of types I and II to identify bone and cartilage formation.

Results: Both chondrogenesis and osteogenesis were initiated in the tibia 1 week after implantation of OCP and most of the cartilage was replaced by bone at week 2. However, the parietal bone did not show osteogenesis responding to OCP implantation until week 3, and no cartilage formation was associated with the osteogenesis.

Conclusions: The present study demonstrated the distinct characteristics of biological response to OCP implantation between the long bone and the calvarium in terms of whether or not cartilage formation is involved in the stimulated osteogenesis by OCP, and in terms of timing of the stimulated chondrogenesis and/or osteogenesis, i.e., the parietal bone takes more time to respond to OCP implantation than the tibia. © 1995 Wiley‐Liss, Inc.
Vascular anatomy of the rabbit ureter
Authors: Douglas Glenn C. , Hossler Fred E.
Published: February 2005

Background: The success of kidney transplant surgery and ureteral reconstruction requires the preservation of the ureteral blood supply. Because of its potential vulnerability to surgical trauma during trans plant and reconstructive surgery, the ureteral vasculature merits a full anatomical description.

Methods: The microvascular anatomy of the ureter was studied in male New Zealand white rabbits by light microscopy and transmission electron microscopy and scanning electron microscopy of vascular corrosion casts and alkali digested tissue.

Results: The rabbit ureter is supplied predominantly by a branch of the renal artery proximally (cranial ureteral artery) and by a branch of the vesicular artery distally (caudal ureteral artery). Minor vascular continuities are also present between the capillary beds of the ureter and those of the renal pelvis cranially and the bladder wall caudally. There are no external vascular connections to the middle ureter with the exception of a single, small vein which drains into the inferior vena cava. A single group of longitudinal arteries and veins runs the full length of the ureter within the adventitia. Branches of these longitudinal vessels pass tangentially through the muscularis to supply a vascular complex within the lamina propria. This complex in turn supports a rich, mucosal capillary plexus located at the junction between the transitional epithelium and the lamina propria. In the fixed ureter the capillary plexus lies in grooves formed by displacement of the basal layers of the overlying transitional epithelium. The capillaries are continuous or fenestrated, are often invested with pericytes, and are distributed uniformly around the entire circumference of the ureter.

Conclusions: The ureteral vasculature exhibits several unique features related to its function in urine conduction and its ability to accommodate expansion and contraction. The combination of techniques used provides a clear three‐dimensional view of this vasculature. Our findings also confirm that, because of its limited blood supply, the ureter may be very susceptible to injury during renal transplantation or other abdominal surgery. © 1995 Wiley‐Liss, Inc.
Origin of subepicardial cells in rat embryos
Authors: van den Eijnde Stefan Maarten , Wenink Arnold Christiaan Gerard , Vermeij‐Keers Christl
Published: February 2005

Background: The role of the villi and vesicles of the epicardium primordium in the formation of the epicardium has been extensively studied over the last decades. With regard to the cellular contents of the villi and vesicles of the epicardium primordium, in quail the presence of mesenchymal cells in the villi recently has been described. In the present study, we have determined whether the villi and vesicles of the epicardium primordium in rat embryos contain mesenchymal cells that originate from the transverse septum and if so, whether these cells will become part of the subepicardium.

Methods: Mesenchymal cells in the transverse septum of rat embryos were labelled by a method consisting of in vitro whole embryo culture and labelling of the ectoderm and its daughter cells, using wheat germ agglutinin‐gold (WGA‐Au) as a marker.

Results: In concordance with our observations in the standard noncultured rat embryos, labelled cells were present in the transverse septum, extending from the umbilical ring, i.e., the transition of amniotic epithelium to ectoderm, up to the villi, in the villi and vesicles, and subepicardially.

Conclusions: These observations suggest that the epicardium primordium contains mesenchymal cells derived from the transverse septum. These cells reach the subepicardium, using the villi and vesicles of the epicardium primordium as their vehicle. © 1995 Wiley‐Liss, Inc.
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

Background: 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

Background: 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

Background: 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

Background: 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

Background: 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

Background: 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

Background: 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

Background: 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

Background: 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

Background: 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

Background: 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

Background: 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.
Sperm nuclei entering parthenogenetically activated mouse oocytes before the first mitosis transform into pronuclei an ultrastructural study
Authors: Maleszewski Marek
Published: February 2005

Background: This report is an extension of previous observations (Maleszewski 1992. Mol. Reprod. Dev., 33:215–221) on the behavior of mouse sperm nuclei incorporated into parthenogenetically activated mouse oocytes prior to the first cleavage division and undergoing transformation during mitosis.

Method: Artificially activated mouse oocytes were inseminated in vitro and an ultrastructural analysis was performed of sperm‐derived nuclei present in two parthenogenetic two‐cell embryos.

Results: Both chromatin and nuclear envelope of sperm derived‐nuclei are structurally identical with those of oocyte‐derived nuclei and of the nuclei of blastomeres of normal two‐cell embryos.

Conclusions: Cytoplasm of the parthenogenote during the first mitotic division has the ability to transform sperm nucleus into a male pronucleus just like the cytoplasm of a metaphase II oocyte. © 1995 Wiley‐Liss, Inc.
Effect of bacoside A on membrane‐bound ATPases in the brain of rats exposed to cigarette smoke
Authors: Anbarasi K. , Vani G. , Balakrishna K. , Devi C. S. Shyamala
Published: February 2005

Membrane‐bound enzymes play a vital role in neuronal function through maintenance of membrane potential and impulse propagation. We have evaluated the harmful effects of chronic cigarette smoking on membrane‐bound ATPases and the protective effect of Bacoside A in rat brain. Adult male albino rats were exposed to cigarette smoke for a period of 12 weeks and simultaneously administered with Bacoside A (the active principle isolated from Bacopa monniera) at a dosage of 10 mg/kg b.w/day, p.o. The levels of lipid peroxides as marker for evaluating the extent of membrane damage, the activities of Na+/K+‐ATPase, Ca2+‐ATPase and Mg2+‐ATPase, and associated cations sodium (Na+), potassium (K+), calcium (Ca2+), and magnesium (Mg2+) were investigated in the brain. Neuronal membrane damage was evident from the elevated levels of lipid peroxides and decreased activities of membrane‐bound enzymes. Disturbances in the electrolyte balance with accumulation of Na+ and Ca2+ and depletion of K+and Mg2+ were also observed. Administration of Bacoside A inhibited lipid peroxidation, improved the activities of ATPases, and maintained the ionic equilibrium. The results of our study indicate that Bacoside A protects the brain from cigarette smoking induced membrane damage. © 2005 Wiley Periodicals, Inc. J Biochem Mol Toxicol 19:59–65, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20050
Visual responses in crayfish. III. Further studies on transmission through the brain
Authors: Camougis George , Kasprzak Hedwig
Published: February 2005

Responses to illumination of the eyes of the crayfish were studied by gross recording from one of the circumesophageal connectives. Two‐thirds of the spontaneous activity at this level of the CNS consists of ascending activity, which is eliminated by cutting a connective posterior to the recording electrode. An average of about eight fibers in a connective responded to 1 sec illumination of the homolateral eye. The fibers were of four types: pure‐on units, on‐sustained units, on‐and‐off units and pure‐off units. The average latency was 74 msec for the on‐response and 26 msec for the off‐response. The latency of responses to 10 μsec flashes of increasing intensity shortened from 72 to 52 msec. This was demonstrated to be mainly a peripheral effect since ERG latency showed a parallel reduction while the ERG‐connective response interval remained more nearly constant at 40–50 msec. ERG amplitude, frequency, and usually the duration of the connective spike discharge increased at greater stimulus intensities, yet the average number of responding fibers was greatest at intermediate intensities. The results indicate minimal processing of response patterns by the brain.
The effects of modified ringer's solutions on the membrane potentials of innervated and denervated frog sartorius muscle fibers
Authors: Levine Leonard
Published: February 2005

Comparison has been made between innervated and chronically denervated frog sartorius muscle fibers for resting potentials and a number of features of the action potential. Muscles were obtained from force‐fed frogs maintained at room temperature for periods up to one year, and were studied with intracellular microelectrodes. Denervated muscles increased in sensitivity to acetylcholine by 100–400‐fold. Studies were made in normal Ringer's solution, and in media in which concentrations of K+, Na+, Ca++, and Cl− were altered. The only significant differences noted between the denervated and the innervated fibers were a reduction in the maximum rate of fall of the action potential (ca. 20%) and an increase in the fall time of the active membrane potential (ca. 25%). These differences were present in normal Ringer's solution and remained when the bathing medium was modified. The resting membrane potential of denervated and innervated muscles varied with log [K+]o in exactly the same manner, and followed the theoretical relation proposed by Hodgkin (Proc. Roy. Soc., B, 148: 1–37, ′58), with the term representing the ratio of the sodium to potassium permeabilities assigned a value of 0.01. The results suggest that (a) the resting sodium and potassium permeabilities are reduced proportionately after denervation, since it is known that denervated frog muscle has a smaller potassium permeability, and (b) the mechanism controlling the increase in potassium conductance during the action potential is less available after denervation. Data indicate that the system controlling the sodium permeability is capable of activation to the same extent as in innervated muscles. Muslces which had been allowed to reinnervate did not show the differences presented by the denervated muscles. Innervated and denervated muscles did not show any significant changes in maximum rates of rise or fall of the action potential, nor of the active membrane potential amplitude over a 30 mV range of resting membrane potentials, indicating that the sodium and potassium permeability systems are fully available in frog muscle at membrane potentials larger than −80 mV.
Separation of rabbit red cells by density in a bovine serum albumin gradient and correlation of red cell density with cell age after in vivo labeling with 59Fe
Authors: Bishop Charles , Prentice Theodore C.
Published: February 2005

Rabbit red cells are separated by centrifuging them for one hour at 33,000 G in density gradient tubes of bovine serum albumin. The separation represented an equilibrium situation since rebanding experiments showed that the cells from a layer would again seek that density layer when recentrifuged in a new gradient tube. When rabbits were injected with 59Fe, the radioactive red cells at one day were nearly all light, but these labeled cells moved into the more dense layers over the next few days. This not only shows that the separation by density is discriminating but that some red cells became dense very quickly. Bearing in mind the problems of interpreting radioactive iron data because of the possibility of reutilization, it is tentatively concluded that dense red cells are not necessarily senescent red cells since these dense cells appear to persist for the normal life span of the rabbit red cell.
The effect of serum albumin on the efflux of K42 from frog sartorius muscle
Authors: Armstrong William McD. , Knoebel Suzanne B.
Published: February 2005

The effect of serum albumin on the washout of K42 from isolated frog sartorius muscles, previously labeled in vitro with this isotope, has been investigated. Incorporation of 1% serum albumin in the washout fluid has been found to cause a significant reduction in the rate constant for K42 loss from the muscle fibers. A similar reduction in the rat constant for K42 efflux was observed when the medium, though not containing protein, was exhaustively dialyzed before use against a solution containing serum albumin. Addition of 10−6 M HgCl2 to “dialyzed” Ringer increased the rate of loss of K42 from the fibers. Effects similar to those obtained with serum albumin were observed when 10−4 M cysteine was incorporated in the washout fluid. 3‐mercapto‐propanol gave rise to transient reductions in the rate of K42 efflux, but, following prolonged exposure to this agent, the efflux rate was increased. 2′3‐dimercapto‐propanol (BAL) increased the rate of K42 loss from the fibers. It is suggested that this effect of serum albumin is due to its sequestering action on toxic substances (tentatively identified as heavy metals) normally present in trace amounts in Ringer's solutions.
RNA synthesis and cell division in cold‐synchronized cells of Tetrahymena pyriformis
Authors: Moner J. G. , Berger R. O.
Published: February 2005

Cells of Tetrahymena pyriformis have been cold‐synchronized using a repetitive cycle of six, two‐hour cold shocks (9.5°C) alternating with decreasing periods (60–30 minutes) at 28°C. This system gives a maximum division index of 70–80% occurring at 90 minutes from the end of the last synchronizing cold‐treatment (EC). Examination of the division sensitivity of these cells to actinomycin D applied continuously at ten‐minute intervals from EC reveals that division is essentially blocked until approximately 40 minutes past EC, after which a rapid decrease is sensitivity to the inhibitor occurs. Coinciding with this period of high sensitivity is the occurrence of a peak of C14 uridine incorporation at 40 minutes past EC. Inhibition of this peak is correlated with an inhibition of division, whereas strong inhibition of RNA synthesis beyond 60 minutes past EC has little effect on division activity. The similarity of these findings with those of the heat‐synchronized system is discussed with the suggestion that both heat‐ and cold‐synchronizing treatments result in the synchronous resynthesis of a division‐associated fraction of RNA.
The effect of hematoporphyrin and light on human platelets. II. Uptake of hematoporphyrin
Authors: Solomon Harvey M. , Zieve Philip D. , Krevans Julius R.
Published: February 2005

A linear relationship was demonstrated between the reciprocals of the concentration of free hematoporphyrin and the moles of hematoporphyrin taken up by the platelet in the dark. radiated platelets took up more hematoporphyrin than did controls; this increase in uptake was accounted for by the movement of the dye across the damaged membrane of the cell. platelets irradiated at 4°c remained impermeable to hematoporphyrin until warmed to 37°c. during the initial three to four minutes of exposure to light at 37°c, there was no additional uptake of hematoporphyrin by platelets in comparison to controls. between six to ten minutes irradiation, the uptake of hematoporphyrin increased linearly with the log time of irradiation. thereafter, no further uptake occurred. a further increase in uptake of dye was demonstrated by both control and irradiated platelets at a reduced ph. this study enables a correlation to be made between the effects of hematoporphyrin on the platelet and the uptake of this agent by the platelet.
Respiratory activity of avian blood cells
Authors: Besch Emerson L.
Published: February 2005

The respiratory activity of avian blood cells was determined with samples of whole blood from individual male and female chickens. this oxygen consumption represents only that of the cells since no measurable activity was found in the plasma samples. the precision of determining respiratory activity was examined statistically and found to be approximately that obtained with a blood cell count but much less precise than the packed cell volume determination. the variability of cell count and mean corpuscular volume indicates that neither is a good means for expressing oxygen consumption – the most meaningful basis is oxygen consumption per milliliter of cells. the relationship between blood cell respiration and temperature is described.
Anti‐mitotic effects of colchicine and hydrostatic pressure; synergistic action on the cleaving eggs of Lytechinus variegatus
Authors: Marsland Douglas
Published: February 2005

Low concentrations (below 0.00005 m) of colchicine and low intensities (below 2,800 psi) of pressure, applied separately to early prophase eggs (lytechinus variegatus) produced no measurable inhibition of the first cleavage division (at 20°c). in combination, however, these subliminal treatments produced marked inhibition. complete blockage, in fact, was observed: at 2,300 psi for eggs in 0.00004 m colchicine; at 2,500 psi for eggs in 0.00003 m; and at 2,800 psi for eggs in 0.00002 m solutions.

The curves obtained by plotting percentage inhibition as a function of pressure for each of the colchicine concentrations specified above were approximately parallel to one another; but each decrement in the colchicine concentration shifted the curve about 300 psi higher along the (pressure) abscissa.

In short, a distinct synergism was found in reference to the anti‐mitotic effects of colchicine and pressure. This result is quite opposite to that reported previously in regard to the actions of heavy water and high pressure.

As to basic mechanism, the evidence indicates that both colchicine and pressure exert their effects by inhibiting polymerization of the subunits of a fibrous protein which constitutes an important structural component of the mitotic apparatus or by depolymerizing the mitotic protein, if it already has been formed at the time of treatment.
Movements of myelin sheath particles in a weak electric field
Authors: Wiener Henry , Wolman Moshe
Published: February 2005

When a weak electric field is applied to longitudinal sections of myelinated nerve, myelin material migrates out of the tissue edges towards both poles. the materials migrating from the anodal and cathodal edges seem to be chemically similar but differ in physical properties. at the anodal edge the bimolecular lipid layers rearrange into spherical micelles forming an “oil in water” emulsion, and at the cathodal edge into micelles forming a “water in oil” emulsion. the latter is unstable in water and is rapidly transformed into an “oil in water” emulsion. these findings have physiological and structural implications for the study of biological membranes.
Effect of CO2 on the growth of a bleached Euglena
Authors: Tremmel R. D. , Levedahl B. H.
Published: February 2005

The addition of CO2 in gaseous form to the growth medium of Euglena gracilis var bacillaris (streptomycin bleached) results in a marked increase in the peak populations reached by the organism. when 20 mm succinate is used as the carbon source, the increase in peak population is proportional to the percentage CO2 enrichment of an air wash up to at least 10% CO2. when acetate is used as a carbon source for growth, some increase is seen in the peak population reached by euglena but the increase is not dependent upon the percentage enrichment of CO2 between 2 and 10% CO2. this extended growth is dependent up the presence of gaseous CO2; bicarbonate ion actually inhibiting growth. thiamin is not required for the CO2 effect, in fact no thiamin requirement can be demonstrated for this organism under the conditions of this experiment.
Ion and water shifts produced by ammonium chloride in high K and low K red cells
Authors: Salminen Simo , Manninen Vesa
Published: February 2005

The effect of ammonium chloride on the cellular Na+, K+ and water has been examined in human and horse (high K), cow (medium K) and cat (low K) red cells. It was found that high K red cells, especially those of the horse, gained water an Na+, whereas the net movement of K+ was negligible. There was a correlation between the increase of cellular Na+ concentration and of the packed red cell volume. In contrast, the packed cell volume of low K red cells increased slightly or not at all, and Na+ ions leaked out from the cells. The high K cells had a lower Cl− concentration and higher buffer capacity than the low K cells. The results obtained with the medium K (cow) cells usually lay between those of the other two cell types. In all the cases both the plasma and cell pH decreased resulting from the addition of ammonium chloride. The mechanism of movements of water and Na+ ions in high K cells remained unsolved, but the response of low K cells to ammonium chloride was near that of a cation exchange resin.
Energy requirement for the incorporation of amino acids into protein of isolated mouse‐liver mitochondria
Authors: Delaney Patrick F. , Girardot Norman J.
Published: February 2005

Mitochondria isolated from mouse liver can incorporate amino acids into mitochondrial protein. Studies with oligomycin and antihistamine drugs indicate that this incorporation may not be an ATP requiring process.
The effect of hematoporphyrin and light on human platelets. III. Release of potassium and acid phosphatase
Authors: Zieve Philip D. , Solomon Harvey M.
Published: February 2005

Human platelets, exposed to hematoporphyrin and light, were depleted of potassium and acid phosphatase. A linear relationship was demonstrated between the per cent depletion of potassium from irradiated platelets and the log dose of hematoporphyrin. The initial release of potassium and acid phosphatase from irradiated platelets was first order. Rate constants demonstrated that potassium was released five times faster than acid phosphatase. At 4°C, release of both potassium and acid phosphatase was the same as at 37°C. These results are compared to previous data on the release of serotonin from irradiated platelets.
Enzyme distribution in “naturally‐decapitated” bull spermatozoa: Acetylcholinesterase, adenylpyrophosphatase and adenosinetriphosphatase
Authors: Nelson Leonard
Published: February 2005

Naturally‐decapitated spermatozoa were separated into motile flagella and head and immotile flagella by differential and density gradient centrifugation. In preparations microscopically free of cross‐contamination after repeated centrifugation, the heads appeared to be enzymatically inert, while there was virtually no change in the specific activity of the immotile flagella which had been subjected to as much manipulation as the heads. The non‐motile flagella had almost twice the acetylcholinesterase and about one‐third the apyrase activity of the motile flagella. The flagella appear to contain a structurally‐bound adenosinetriphosphatase which may be identical with the “spermosin” extracted from bull sperm.