Effects of size and storage temperature on meiotic competence of domestic cat oocytes.
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Animals↗
Biomedical subjects
M Murakami
Publications and source records attributed to M Murakami.
2-Alkynyl-8-aryl-9-methyladenines as novel adenosine receptor antagonists: their synthesis and structure-activity relationships toward hepatic glucose production induced via agonism of the A(2B) receptor.
Novel adenosine antagonists, 2-alkynyl-8-aryl-9-methyladenine derivatives, were synthesized as candidate hypoglycemic agents. These analogues were evaluated for inhibitory activity on N-ethylcarboxamidoadenosine (NECA)-induced glucose production in primary cultured rat hepatocytes. In general, aromatic moieties at the 8-position and alkynyl groups at the 2-position had significantly increased activity compared to unsubstituted compounds. The preferred substituents at the 8-position of adenine were the 2-furyl and 3-fluorophenyl groups. In modifying the alkynyl side chain, change of the ring size, cleavage of the ring, and removal of the hydroxyl group were well tolerated. The order of the stimulatory effects of adenosine agonists on rat hepatocytes was NECA > CPA > CGS21680, which is consistent with involvement of the A(2B) receptor. In Chinese hamster ovary cells stably transfected with human A(2B) receptor cDNA, one of the compounds potent in hepatocytes, 15o (IC(50) = 0.42 microM), antagonized NECA-induced stimulation of cyclic AMP production (IC(50) = 0.063 microM). This inhibitory effect was much more potent than those of FK453, KF17837, and L249313 which have been reported to be respectively A(1), A(2A), and A(3) selective antagonists. These findings agree very well with the result that, compared to 15o, these selective antagonists for each receptor subtype showed only marginal effects in rat hepatocytes. These results suggest that adenosine agonist-induced glucose production in rat hepatocytes is mediated through the A(2B) receptor. Furthermore, 15o showed hypoglycemic activity in an animal model of noninsulin-dependent diabetes mellitus, the KK-A(y) mice. It is possible that inhibition of hepatic glucose production via the A(2B) receptor could be at least one of the mechanisms by which 15o exerts its in vivo effects. Further elaboration of this group of compounds may afford novel antidiabetic agents.
Adenine↗
Reciprocal subsidies: dynamic interdependence between terrestrial and aquatic food webs.
Mutual trophic interactions between contiguous habitats have remained poorly understood despite their potential significance for community maintenance in ecological landscapes. In a deciduous forest and stream ecotone, aquatic insect emergence peaked around spring, when terrestrial invertebrate biomass was low. In contrast, terrestrial invertebrate input to the stream occurred primarily during summer, when aquatic invertebrate biomass was nearly at its lowest. Such reciprocal, across-habitat prey flux alternately subsidized both forest birds and stream fishes, accounting for 25.6% and 44.0% of the annual total energy budget of the bird and fish assemblages, respectively. Seasonal contrasts between allochthonous prey supply and in situ prey biomass determine the importance of reciprocal subsidies.
Animals↗
Effect of methylprednisolone on the kinetics of cytokines and liver function of regenerating liver in rats.
The participation of cytokines in the early stage mechanism of hepatocyte proliferation has already attracted attention. We investigated the effect of methylprednisolone (MDS), which inhibits the inflammatory response, given before and after a 70% partial hepatectomy in rats on the kinetics of tumor necrosis factor-alpha and Interleukin-6, liver cell function and the rate of liver regeneration. Serum Interleukin-6 levels of the MDS groups were significantly lower than those of the control group. Serum alanine aminotransferase, aspartate aminotransferase and hyaluronic acid levels were also significantly decreased, however, the serum albumin level showed high values in the MDS groups. In the MDS groups, MIB-5 labeling indices, a novel antibody reactive with the equivalent Ki-67 protein, which detects immunohistochemically all active parts of the cell cycle in the rat liver, were more pronounced than in the control group at an earlier time. However, in regard to 5-bromo-2-deoxyuridine (BrdU), there were no significant differences among the three groups. There were no differences in residual liver weight/body weight between the three groups after 336 h. In our study, MDS administration before or after a 70% partial hepatectomy decreased serum Interleukin-6 levels, and inhibited hepatic dysfunction. Therefore, we considered that beneficial effects of physiological doses of MDS in the peri-operative period should be confirmed in humans.
Journal Article↗
Characterization of EBV-infected epithelial cell lines from gastric cancer-bearing tissues.
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Animals↗
Lethal adenovirus infection in a patient who had undergone nonmyeloablative stem cell transplantation.
We present a case of adenovirus (ADV) infection in a patient who had undergone nonmyeloablative stem cell transplantation (NST). A 50-year-old man with chronic myelogenous leukemia in the second chronic phase underwent NST from an HLA 2-loci-mismatched sibling. ADV hemorrhagic cystitis developed and progressed to lethal pneumonia. ADV was isolated from urine, bronchoalveolar lavage fluid, and postmortem specimens of kidney and liver. Because there are few reports of lethal pneumonia associated with ADV in Japan, we present the case and discuss the cause of and therapy for the infection.
Adenoviridae Infections↗
Acute up-regulation of brain-derived neurotrophic factor expression resulting from experimentally induced injury in the rat spinal cord.
Brain-derived neurotrophic factor (BDNF), a member of the nerve growth factor family of trophic factors, has multiple functions including a role in the promotion of neuronal survival and nerve fiber elongation in both the central and the peripheral nervous systems. We assessed the expression of endogenous BDNF following an experimentally induced compression injury to the spinal cord. Expression of BDNF mRNA was increased following the spinal cord injury; reaching maximum levels 24 h after the injury. Expression of BDNF mRNA returned to the levels observed in sham-operated control animals within 3 days of the injury. Using the in situ hybridization technique, we observed a wide distribution of BDNF expression among the different cell types in the spinal cord, including motor and sensory neurons, and in glia cells, including astrocytes. We also observed expression of BDNF in putative macrophages and/or microglia; however, this effect was not observed until day 7 following spinal cord injury. These results suggest that BDNF is synthesized in both neurons and astrocytes during the acute response to injury to the spinal cord, functioning in a mainly neuroprotective role. This is followed by a later phase of expression in which BDNF is produced by macrophages and/or microglia, apparently functioning in a restorative capacity.
Animals↗
Anti-transforming growth factor-beta1 antibody transiently enhances DNA synthesis during liver regeneration after partial hepatectomy in rats.
The regulation of liver regeneration after partial hepatectomy (PHx) is complex and involves many different cytokines. We investigated the role of one of these, transforming growth factor-beta1 (TGF-beta1), an inhibitor of liver regeneration, in a Wistar male rat model, in which anti-TGF-beta1 antibody was injected immediately or 24 h after 70% PHx. Livers from treated animals contained an increased number of cells in S phase, according to 5-bromo-2'-deoxyuridine (BrdU) labeling 36 h after PHx. Antibody administration 24 h after PHx resulted in the highest peak of proliferation; moreover, peak MIB-5 labeling was also observed at that time. However, neither residual liver-weight-to-body-weight ratios nor regeneration rates differed significantly between any of the animals. Therefore, we also measured levels of serum TGF-beta1 and hepatocyte growth factor (HGF; an activator). With antibody administration at 0 or 24 h, TGF-beta1 levels were diminished at 24 or 36 h as compared with levels in control rats, but then rebounded, reaching a delayed peak at 48 or 72 h after PHx, respectively. Interestingly, there were also similar trends in HGF levels. These results indicate that TGF-beta1 may inhibit the G1 checkpoint, and serum TGF-beta1 concentration may influence HGF to regulate liver regeneration and to maintain homeostasis of proliferation after PHx.
Analysis of Variance↗
Power spectral analysis of the electroencephalogram during induced total spinal block.
PURPOSE: To evaluate the effects of total spinal block (TSB) on brain function, TSB-induced changes in cortical electrical activities were analyzed using power spectral analysis of an electroencephalogram (EEG). METHODS: Six patients suffering from chronic pain who were undergoing TSB therapy were studied. TSB was established with intrathecal 1% lidocaine (0.3 ml.kg(-1)) injected through the C1-2 lateral intervertebral space. Mechanical ventilation was continued via a laryngeal mask until the recovery of respiration. The EEG recording was started before TSB induction and continued until 10 min after extubation. The following processed EEG parameters were monitored: spectral edge frequency-90% (SEF90), spectral median frequency (SMF), and relative power in the frequency bands of delta, theta, alpha, beta, and the delta ratio [(alpha + beta)/delta]. RESULTS: TSB induced an unconscious state more than 40 min in all patients. During TSB, 12-13 Hz in SEF90 and 6-7 Hz in SMF were observed. These values are consistent with the previously reported prearousal threshold from general anesthesia. The other EEG descriptors did not change during the TSB-induced unconscious state. CONCLUSION: The dissociation of cortical electrical activities and the clinical coma-like condition may be characteristic of the TSB-induced unconscious state.
Journal Article↗
Relationship between cervical curvature index (Ishihara) and cervical spine angle (C2--7).
The purpose of this study was to determine the relationship between the cervical curvature index (Ishihara) and the cervical spine angle (C2--7) from both cervical lateral radiographs and a geometrical model. The cervical lateral radiographs of 295 outpatients with no cervical symptoms were reviewed to measure the cervical curvature index (Ishihara) and the cervical spine angle (C2--7). The average cervical curvature index (Ishihara) was 10.9 (SD, 15.3) and the average cervical spine angle (C2--7) was 20.3 (SD, 14.3). A highly significant correlation (0.95; 95% confidence interval [CI], 0.94--0.96) was found between the cervical curvature index (Ishihara) and the cervical spine angle (C2--7). Their linear correlation was also validated in the geometrical model. Their correlation diminished, however, in subjects with an S-shaped cervical spine. The cervical curvature index (Ishihara) and the cervical spine angle (C2--7) were interchangeable, but this interchangeability was lost in the S-shaped cervical spines.
Adolescent↗
Diversity and regulatory functions of mammalian secretory phospholipase A2s.
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Animals↗
Chitosan accelerates the production of osteopontin from polymorphonuclear leukocytes.
Chitosan is a copolymer of beta(1 --> 4) glucosamine and N-acetyl-D-glucosamine, which accelerates the infiltration of polymorphonuclear leukocytes (PMN) in the early phase of wound healing. In the granulation tissue treated with chitosan in canine experimental wound, osteopontin (OPN) was strongly positive in PMN immunohistochemically. OPN is a glycosylated phosphoprotein and promotes the attachment or spread of a variety of cell types. In addition, OPN may play a role in granulomatous inflammation. Production of OPN in PMN was therefore investigated in vitro using human PMN in this study. PMN stimulated with granulocyte-colony stimulating factor (G-CSF) and chitosan accumulated OPN mRNA, and released OPN into their culture supernatants. These findings suggest that OPN is synthesized by migrating PMN which plays the novel role of regulating the evolution of wound healing with chitosan treatment at the early phase of healing.
Animals↗
Evaluation effects of chitosan for the extracellular matrix production by fibroblasts and the growth factors production by macrophages.
Chitosan is reported as an accelerator of wound healing. Histological findings of previous reports indicate that chitosan accelerates the reformation of connective tissue, however the details of the mechanism are not clear. In this study, firstly L929 mouse fibroblasts were cultured with chitosan and the production of extracellular matrix (ECM) was evaluated in vitro. Type I and III collagens and fibronectin were secreted by L929 with or without chitosan; however there was no significant difference in the amount of ECM between the control and the chitosan groups. Secondly, macrophages were stimulated with chitosan, and then transforming growth factor-beta 1 (TGF-beta1) and platelet-derived growth factor (PDGF) messenger ribonucleic acid (mRNA) expressions and production of their proteins were assayed in vitro. As a result, chitosan promoted the production of TGF-beta1 and PDGF. These results indicate that chitosan does not directly accelerate ECM production by fibroblast and the ECM production may increase by the growth factors.
Animals↗
Rate of health insurance reimbursement and adherence to anti-hypertensive treatment among Japanese patients.
BACKGROUND: Although several studies have reported the effects of free medical care on compliance in patients with hypertension, no study has reported the effects of an economic incentive, such as subsidized medical costs, on compliance with medication protocol, in patients with hypertension. The unique characteristics of the Japanese health insurance system provide for a 10% decrease in the subsidy for medication immediately on retirement (approximately 60 years of age) for insured patients, and a 100% subsidy for insured patients who are 70 years of age or older. We examined the association between level of health insurance coverage and follow-up rate of medical treatment among Japanese patients with hypertension. METHODS: The subjects, from throughout Japan, were patients with hypertension (n=1236). The study was conducted in 1991. The odds of completing a 1-year treatment in relation to the rate of health insurance reimbursement were calculated using multiple logistic regression analysis. RESULTS: We found the following. (1) Compared with the base group, the odds of completing a 1-year treatment increased to 2.62 or 2.51 in the group whose reimbursement rate was 100%. (2) Compared with the base group, the odds of completing a 1-year treatment was no larger than 1 in the group whose reimbursement rate had been 100% for more than 6 years ('76-'). (3) Compared with the base level, the odds of completing a 1-year treatment increased to 1-1.81 in the group whose liability decreased to 80%. CONCLUSION: Although the results imply that even a small economic incentive might be effective in securing a patient's compliance with anti-hypertensive medical treatment, the effect appear limited in both duration and magnitude.
Aged↗
DAF-7/TGF-beta expression required for the normal larval development in C. elegans is controlled by a presumed guanylyl cyclase DAF-11.
In C. elegans development, unfavorable growth conditions lead a larva to an arrested and enduring form called a dauer. To elucidate components upstream of DAF-7/TGF-beta in this control pathway, we isolated a mutant that was defective in daf-7 promoter::gfp reporter expression and showed an arrested (dauer-constitutive) phenotype. It has a new mutation in the daf-11 gene encoding a transmembrane guanylyl cyclase. We show that daf-11 gene and a related gene daf-21 act upstream of daf-7, and cilium-related genes che-2 and che-3 are placed between daf-11 and daf-7, in the genetic pathway controlling dauer formation. Expression of daf-11 cDNA by cell specific promoters suggests that daf-11 acts cell autonomously in ASI chemosensory neurons for daf-7 expression.
Alleles↗
Iantherans A and B, unique dimeric polybrominated benzofurans as Na,K-ATPase inhibitors from a marine sponge, Ianthella sp.
Two novel tetrabrominated benzofuran derivatives, named iantherans A and B, were isolated from an Australian marine sponge of the genus lanthella. The unique structures comprised of 2,3-bis(sulfooxy)-1,3-butadiene and two brominated benzofuran moieties were determined by spectroscopic and chemical methods. Iantheran A has a (Z,Z)-1,3-butadiene moiety, whereas iantheran B is the geometric isomer possessing a (Z,E)-1,3-butadiene moiety. The inhibitory activities of the iantherans and their derivatives against Na,K-ATPase as well as the efficacy of iantheran A against other several enzymes were evaluated.
Animals↗
2-Alkynyl-8-aryladenines possessing an amide moiety: their synthesis and structure-activity relationships of effects on hepatic glucose production induced via agonism of the A(2B) adenosine receptor.
A series of 2-alkynyl-8-aryladenine derivatives bearing an amide moiety at the 9-position of adenine was synthesized. These analogues were evaluated for inhibitory activity on N-ethylcarboxamidoadenosine (NECA)-induced glucose production in primary cultured rat hepatocytes. The m-primary benzamide derivative 15f was the most potent compound (IC(50)=0.017 microM), being 15-fold more active than the corresponding 9-methyl derivative (1). Compound 15f showed 72- and 5.2-fold selectivity for human A(2B) receptor versus human A(1) and A(2A) receptors, respectively. Structure-activity relationship (SAR) studies of the synthesized compounds indicated that a three-carbon linker, fixed in the form of a benzene ring, between the adenine core and the amide moiety is important for both A(2B) antagonistic activity and selectivity. The IC(50) values in rat hepatocyte glucose assay correlated well with the IC(50) values in cAMP assay using Chinese hamster ovary cells stably transfected with human A(2B) receptors (r(2)=0.94). The A(1) and A(2A) affinities showed no correlation with the potency to inhibit NECA-induced glucose production. These results strongly support our previous conclusion that adenosine agonist-induced hepatic glucose production in rat hepatocytes is mediated through the A(2B) receptor.
Adenine↗
Spontaneous reduction in Epstein-Barr virus (EBV) DNA copy number in EBV-infected epithelial cell lines.
We found that spontaneous and 12-0-tetradecanoylphorbol-13-acetate-induced Epstein-Barr virus (EBV) reactivation occurred in short-term (ST)-cultured EBV-infected epithelial cell lines GT38 and GT39 after their establishment; however, it diminished in the long-term (LT)-cultured cells passaged for more than 2 years from ST-cultured cells. We hypothesized that the EBV reactivation may be related to the EBV DNA copy number in the cells. A higher level of EBV DNA content was detected in ST-cultured cells than in LT-cultured cells by Southern hybridization using an EBV DNA XhoI probe. Fluorescence in situ hybridization using EBV DNA BamHI W fragments showed that ST-cultured cells contained a higher EBV DNA copy number than that of LT-cultured cells. EBV DNA-negative cells were detected in small proportions in LT-cultured cells, but were undetected in ST-cultured cells. These results demonstrate that EBV genomes are not maintained stably in the cell lines, and some of them are lost in continuous passages of the cells. We discuss the mechanisms of reduction of EBV reactivation and EBV DNA in the cell lines.
Animals↗