Outbreaks of enterohaemorrhagic Escherichia coli O157:H7 infection by two different genotype strains in Japan, 1996.
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Child↗
Biomedical subjects
H Watanabe
Publications and source records attributed to H Watanabe.
Inhibition of agonist-induced Ca2+ entry in endothelial cells by myosin light-chain kinase inhibitor.
Identification of the signal which links the depletion of Ca2+ stores to a Ca2+ entry pathway in the plasma membrane remains to be determined. In the present study, effects of ML-9 and wortmannin, inhibitors of myosin light-chain kinase (MLCK), on agonist-stimulated Ca2+ response were investigated in porcine aortic endothelial cells loaded with the Ca(2+)-sensitive dye fura-2. Bradykinin (BK) caused a rapid increase in [Ca2+]i, followed by a sustained increase due to the influx of Ca2+ from the extracellular space. ML-9 almost completely abolished the sustained increase in [Ca2+]i in BK-stimulated cells, while it did not affect the mobilization of Ca2+ from intracellular stores. ML-9 also abolished the sustained increase in [Ca2+]i caused by thapsigargin. Wortmannin mimicked the effect of ML-9 on the thapsigargin-stimulated Ca2+ response. These findings document for the first time the involvement of MLCK inhibitor in Ca2+ signaling in endothelial cells.
Androstadienes↗
Kinetics of vacancy diffusion on Si(111) surfaces studied by scanning reflection electron microscopy.
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Journal Article↗
c-kit+ stem cells and thymocyte precursors in the livers of adult mice.
Livers of the adult mice contain c-kit+ stem cells that can reconstitute thymocytes, multiple lineage cells, and bone marrow (BM) stem cells. Transfer of 1 x 10(7) hepatic mononuclear cells (MNC) and 5 x 10(4) hepatic c-kit+ cells of BALB/c mice induced DP thymocytes within a week in four Gy-irradiated CB17/-SCID mice, but 2 wk were required for BM cells or BM c-kit+ cells to produce DP thymocytes. Moreover, B cell-depleted BM cells or liver MNC of SCID mice that had been rescued by hepatic MNC of BALB/c mice again reconstituted thymus and B cells of other irradiated SCID mice. CD3- IL-2R beta- populations of both BM cells and hepatic MNC of C57BL/6 (B6) mice could generate T cells with intermediate TCR (mostly NK1.1-) in the liver of irradiated B6 SCID mice before thymic reconstitution (extrathymic T cells). Furthermore, transfer of liver c-kit+ cells of B6-Ly 5.1 mice into irradiated B6 SCID (Ly5.2) mice revealed that liver c-kit+ cells can reconstitute myeloid and erythroid lineage cells. These results strongly suggest that the liver contains pluripotent stem cells and serves an important hematopoietic organ even into adulthood.
Animals↗
NMDA-but not AMPA-receptor antagonists augment scopolamine-induced spatial cognitive deficit of rats in a radial maze task.
The effect of NMDA and AMPA receptor antagonists on a scopolamine-induced spatial cognitive deficit was investigated in rats using an 8-arm radial maze. The NMDA antagonists, MK801 and CGS19755, robustly augmented scopolamine-induced deficits but had no effect on spatial cognition when administered alone. In contrast, augmentation of the scopolamine-induced deficits was not observed when the selective AMPA antagonist, YM90K, was administered with scopolamine. These results suggest that the NMDA but not AMPA subtypes of the ionotropic glutamate receptors play important roles in regulation of the central cholinergic function related to the spatial learning and memory processes.
Animals↗
Tumor cell autocrine motility factor is the neuroleukin/phosphohexose isomerase polypeptide.
To date, the structure of the autocrine motility factor (AMF), a tumor-secreted cytokine which stimulates cell migration in vitro and metastasis in vivo, is unknown. Here, AMF secreted by Gc-4 PF murine fibrosarcoma into a protein-free conditioned media was isolated, purified, and microsequenced. The results demonstrate that AMF is the previously cloned cytokine and enzyme designated as neuroleukin, and phosphohexose isomerase (PHI), which has been independently implicated in cell motility, and to be a cancer progression marker. PHI catalyzes isomerization of glucose 6-phosphate to fructose 6-phosphate and is specific for both sugars. Murine AMF exhibits the enzymatic properties of PHI and rabbit heart PHI-stimulated mouse fibrosarcoma cells' motility similar to those of the endogenous AMF. Specific PHI inhibitors (carbohydrate phosphates) inhibited enzymatic activity and AMF-induced cell motility.
Amino Acid Sequence↗
Sequence analysis of the L-lactate dehydrogenase-encoding gene of Deinococcus radiodurans, a suitable mesophilic counterpart for Thermus.
A gene encoding L-lactate dehydrogenase (LDH; EC 1.1.1.27) from Deinococcus radiodurans (Dr) was cloned and sequenced. The deduced amino acid (aa) sequence was compared to those of the Thermus aquaticus (Ta) and T. caldophilus (Tc) LDH. The similarity of the G + C contents between the Dr and Thermus genes permits the comparison of the aa sequences of LDH without considering the difference in the G + C contents. Compared to the mesophilic Dr LDH, increased numbers of hydrophobic aa, together with hydrophilic Arg, were found in the LDH from Ta and Tc, suggesting that these features would contribute to protein thermostability in part via hydrophobic and electrostatic interactions in the protein globule. Deinococcus would be a suitable mesophilic counterpart for Thermus to investigate the thermostability of proteins.
Amino Acid Sequence↗
A comparison of proliferative response to IL-7 and expression of IL-7 receptors in intermediate TCR cells of the liver, spleen, and thymus.
It is well established that IL-7 supports the earliest differentiation of both T and B cells in fetal and adult life. On the other hand, mature lymphocyte subsets tend to decrease the response to IL-7 in case of T and B cells. In a recent study, NK1.1+ T cells in the thymus are also found to efficiently respond to IL-7 and express IL-7 receptors (IL-7R). This population is generated through an alternative intrathymic pathway. A similar population, namely, T cells with intermediate levels of TCR (i.e., int TCR cells) are known to be generated through extrathymic pathways. In this respect, the proliferative response to IL-7 and the expression of IL-7R in int TCR cells of various organs were compared. Whole liver MNC and isolated int TCR cells from the liver were found to proliferate in response to IL-7. Moreover, a considerable population of int TCR cells in both the liver and thymus were found to carry a higher density of IL-7R on the surfaces than high TCR cells. More precisely, the intensity of IL-7R on int TCR cells in the thymus was the highest but those on int TCR cells in other organs were slightly lower (i.e., int TCR cells in the thymus greater than int TCR cells in the liver greater than high TCR cells). Taken together with the result of expression of IL-7 mRNA by hepatocytes and thymic tissues, it is concluded that IL-7 is one of the most important growth factors for int TCR cells both in the liver and thymus.
Animals↗
Ciliary neurotrophic factor attenuates spatial cognition impairment, cortical infarction and thalamic degeneration in spontaneously hypertensive rats with focal cerebral ischemia.
Ciliary neurotrophic factor (CNTF) has been shown to exhibit potent neurotrophic activity on peripheral and central neurons in vitro and in vivo. However, it remains to be determined whether or not CNTF rescues neuronal loss due to focal cerebral ischemia and prevents ischemia-induced disability of space navigation in rats. In the present in vivo study, we infused CNTF continuously for 4 weeks into the lateral ventricle, starting just after permanent occlusion of the left middle cerebral artery (MCA) of stroke-prone spontaneous hypertensive rats. CNTF infusion prevented the occurrence of ischemia-induced learning disability in a dose-dependent manner in rats subjected to the Morris water maze task. Subsequent histological examinations showed that cortical infarction and retrograde degeneration of the ipsilateral thalamic neurons in ischemic rats infused with CNTF were significantly less severe than those in ischemic rats infused with vehicle alone. These findings suggest that postischemic CNTF treatment prevents the occurrence of spatial learning disability in rats with permanent MCA occlusion, possibly by reducing neuronal damage within the cerebral cortex and secondary retrograde degeneration of the thalamus.
Analysis of Variance↗
Neurosteroidal modulation of social isolation-induced decrease in pentobarbital sleep in mice.
Stressful manipulations are known to change the level of neurosteroids capable of interacting with GABAA receptor in the brain. To clarify the involvement of these neurosteroids in social isolation stress-induced decrease in pentobarbital sleep in mice, we examined the effects of 3 beta-hydroxy-5-pregnen-20-one-3-sulfate (pregnenolone sulfate, PS), a steroidal GABAA antagonist, and 3 alpha,21-dihydroxy-5 alpha-pregnan-20-one (allo-THDOC) and 3 alpha,21-dihydroxy-5 beta-pregnan-20-one (THDOC), positive allosteric modulators of the GABAA receptor, on the hypnotic activity of pentobarbital in socially isolated mice. Pentobarbital (50 mg/kg, i.p.)-induced sleep was significantly shorter in isolated mice than in group-housed mice and adrenalectomy had no effect on the decrease of pentobarbital sleep following social isolation. PS (5-10 mg/kg, i.p. or 12-24 nmol, i.c.v.) decreased pentobarbital sleep in group-housed mice in a dose-dependent manner without affecting the sleep in socially isolated mice. In contrast, allo-THDOC (14.9-37.4 nmol, i.c.v.) and THDOC (5-12.5 mg/kg, i.p. or 14.9-37.4 nmol, i.c.v.) reversed the pentobarbital sleep decreased by social isolation to the level in group-housed mice. These steroids had no effect on the pentobarbital sleep in group-housed mice. Such a reversing effect of THDOC in isolated mice was significantly blocked by PS (24 nmol, i.c.v.). Moreover, i.c.v. injection of yohimbine (30 nmol), methoxamine (200 nmol) and CRF (2.1 nmol) significantly decreased pentobarbital sleep in group-housed mice but not that in isolated mice. The effects of these drugs on pentobarbital sleep in group-housed mice were significantly attenuated by THDOC (12.5 mg/kg, i.p.). These results suggest that changes in the level of neurosteroids with ability to modulate GABAA receptor function are involved in social isolation-induced decrease in the hypnotic activity of pentobarbital in mice.
Adrenalectomy↗
Evolution of transcriptional regulation system through promiscuous coupling of regulatory proteins with operons; suggestion from protein sequence similarities in Escherichia coli.
As an advanced molecular study of the problems of the evolution of organisms, the transcriptional regulation system is studied by investigating the amino acid sequence similarities between the proteins in the regulation system of Escherichia coli in which the data of sequenced proteins as well as of regulator-regulon relationships are accumulated. The similarities between the proteins are calculated by the FASTA algorithm and their homology is also evaluated in terms of statistical significance with the use of the RDF2 program. This investigation reveals that the similarity between the regulatory protein and the regulated protein is hardly found, but many similarities are found between regulatory proteins and between regulated proteins. These similarity relations are compared with the regulator-regulon relationships ascertained experimentally. From this comparison, it is found that similar regulatory proteins rarely regulate the transcription of similar protein genes. As most of the highly similar proteins are considered to have diverged from a common ancestral protein, this finding strongly suggests the possibility that descendant regulatory proteins have been promiscuously coupled with descendant operons, independently of their ancestral regulator-regulon relationship, and that some of the couplings have been fixed by selection to form the present system of transcriptional regulation. The compatibility of such promiscuous coupling with regulatory organization is illustrated in the carbohydrate transport systems and the succeeding metabolic pathways, whose organization is comprehensive in sending nutritious substances to the central path of glycolysis under different environmental conditions. The benefit of flexibility in regulator-regulon relationships in evolutionary processes is also discussed in connection with the punctuational divergence of species in macroevolution and the cell differentiation in multicellular organisms.
Amino Acid Sequence↗
Corneal endothelial cell loss after excimer laser keratectomy, associated with tranquilizers.
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Benzodiazepines↗
Recurrent esophageal carcinoma after esophagectomy with three-field lymph node dissection.
To evaluate the effect of the extended lymphadenectomy for thoracic esophageal carcinoma, the pattern of recurrence in the 50 patients with pT3 tumors who underwent esophagectomy with cervical, mediastinal, and abdominal lymph node dissection (3-F) (group A) was compared with that of 100 patients at pT3 who underwent esophagectomy without upper mediastinal and cervical lymphadenectomy (2-F) (group B). The cumulative 5-year survival rate for 115 patients who underwent 3-F was 50.9%. Cumulative 5-year survival rates for patients in groups A and B were 36.8% and 22.0%, respectively. The survival curve for group A was significantly better than group B (P = 0.02332). Lymphatic recurrence was noted less frequently in group A (8/23) than in group B (31/49) (chi 2 = 5.1149), whereas the rate of hematogenous recurrence was similar. Extension of the field of lymph node dissection reduced the lymph node recurrence in patients with thoracic esophageal carcinoma, which may have positively affected patient survival.
Aged↗
Tumor bed implant brachytherapy for residual carcinoma after palliative esophagectomy.
Twenty-six patients with esophageal carcinoma at stage pT4 underwent esophagectomy with lymph node dissection leaving part of the tumor in adjacent organs. Several plastic catheters were fixed to the tumor bed and led to the outside of the thorax for postoperative brachytherapy. Using these catheters, the patients underwent brachytherapy followed by external beam irradiation. The operative mortality rate was 11.5%. No serious complications resulting directly from the brachytherapy occurred. Recurrent disease was found in 17 patients, among whom only six had local recurrence. The median survival of the patients was 314 days, and the 5-year survival rate was 16.2%. Of the 10 patients at stage pT4N0, three survived more than three years after surgery. Tumor bed implant brachytherapy for residual tumor after esophagectomy is a safe and useful treatment strategy for patients with pT4 tumor, especially those without lymph node metastasis.
Aged↗
Bactericidal effect of erbium YAG laser on periodontopathic bacteria.
BACKGROUND AND OBJECTIVE: Recently Erbium (Er) YAG laser has been developed for dentistry. It may be suitable for periodontal therapy. This study examined the bactericidal effect of the Er: YAG laser on periodontopathic bacteria in vitro. STUDY DESIGN/MATERIALS AND METHODS: After spreading the bacterial suspension of Porphyromonas gingivalis or Actinobacillus actinomycetemcomitans on agar plates, a single pulse laser was applied to the agar plates at the energy density of 0.04-2.6 J/cm2. The growth of the bacterial colonies on the lased agar plates was examined after anaerobic culture. P. gingivalis colonies were also individually exposed to the single pulse laser at the energy of 1.8-10.6 J/cm2. The colony forming units of the irradiated colonies were counted. RESULTS: Growth inhibitory zones were found at the irradiated sites at the energy of about 0.3 J/cm2 and higher. The survival ratios of the viable bacteria in the lased P. gingivalis colonies decreased significantly at the energy of 7.1 and 10.6 J/cm2, as compared with that of the control. CONCLUSION: These findings suggest that the Er:YAG laser has a high bactericidal potential at a low energy level.
Aggregatibacter actinomycetemcomitans↗
Prenatal diagnosis of succinyl-coenzyme A:3-ketoacid coenzyme A transferase deficiency.
Succinyl-CoA:3-ketoacid CoA transferase (SCOT) deficiency is a rare disorder of ketone body catabolism. In the present study, we prenatally diagnosed SCOT deficiency in a fetus in a family of which the proband was the first patient with SCOT deficiency identified in Japan, by analysis of enzyme activity levels in samples of chorionic villi and cultured amniocytes. In the fetus of the family, SCOT activity was not detected in either chorionic villi or cultured amniocytes. Since the levels of SCOT activity in control chorionic villi were close to our minimal detectable level and were much lower than those in control cultured amniocytes, enzyme assay in cultured amniocytes was more feasible than that in chorionic villi for prenatal diagnosis of SCOT deficiency. No elevated accumulation of 3-hydroxybutyrate or acetoacetate was detected in the amniotic fluid of the fetus. To our knowledge, this report is the first of prenatal diagnosis of SCOT deficiency.
3-Hydroxybutyric Acid↗
Possible use of ultrasonically-estimated bladder weight in patients with neurogenic bladder dysfunction.
In 25 patients with detrusor areflexia, ultrasonically-estimated bladder weight (UEBW) was compared with bladder capacity and compliance obtained by cystometry, and UEBW was also compared with grade of bladder deformity as evaluated by cystography. UEBW correlated significantly with compliance (P < 0.01) and degree of bladder deformity (P < 0.01). Taking a cutoff value of 40 g, UEBW revealed diagnostic accuracy as high as 96% and 80% for low-compliance (< 10 ml/cm H2O) and high-grade deformity (grade II/III), respectively. UEBW could be a new urodynamic parameter capable of evaluating functional as well as morphological changes of the bladder.
Adult↗
Existence of a small population of IL-2R beta hi TCRint cells in SCG and MRL-lpr/lpr mice which produce normal Fas mRNA and Fas molecules from the lpr gene.
Mice carrying the lpr gene, SCG and MRL-lpr/lpr mice, were used to characterize the phenotype and lpr gene of abnormally proliferating T cells in these mice. A major population which expanded in these mice were T cells expressing intermediate (int) levels of T cell receptor (TCR) (and CD3) and the phenotype of interleukin-2 receptor (IL-2R) beta lo alpha- (possibly abnormal TCRint cells). The levels of TCRhi cells of thymic origin (generated through the mainstream of T cell differentiation in the thymus) profoundly decreased after the onset of disease. However, a small population of normal TCRint cells (i.e. IL-2R beta hi alpha-) were also found to exist in all tested organs. For example, the majority of abnormal IL-2R beta lo TCRint cells were CD4-8- CD2-, while normal IL-2R beta hi TCRint cells were a mixture of single-positive cells (mainly CD8+), CD4-8- cells and CD2+ cells. Moreover, normal TCRint cells preferentially produced normal Fas mRNA and Fas molecules from the lpr gene. This phenomenon explains the leaky appearance of normal Fas mRNA and Fas molecules in mice carrying the lpr gene. It is suggested that a small population of IL-2R beta hi TCRint cells are resistant to the lpr genetic abnormality.
Animals↗