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Biomedical subjects

T Takano

Publications and source records attributed to T Takano.

At least 397 records · Page 22Linked to original sources
PubMed1993

Pathophysiological characteristics of cutaneous microcirculation in patients with liver cirrhosis: relationships to cardiovascular hemodynamics and plasma neurohormonal factors.

To elucidate pathophysiological characteristics of the peripheral circulation in liver cirrhosis, cutaneous microcirculation was analyzed at the finger, palm, toe, and arch of the foot using laser Doppler spectroscopy in 19 patients with liver cirrhosis, and the results were correlated with cardiovascular hemodynamics (n = 10) and plasma neurohormonal factors (n = 8). Cutaneous blood flow at each area was all significantly reduced (P < 0.001, < 0.05, < 0.01, < 0.001, respectively) in patients with liver cirrhosis compared to those in normals (n = 20). Cutaneous blood mass was also significantly reduced (P < 0.05, < 0.01, < 0.001, respectively) except at the arch of foot in patients with liver cirrhosis. There were significant correlations between finger cutaneous blood flow and systemic vascular resistance (r = -0.73, P < 0.05), plasma norepinephrine level (r = -0.84, P < 0.01), plasma renin activity (r = -0.77, P < 0.01), plasma concentrations of aldosterone (r = -0.76, P < 0.05) and angiotensin II (r = -0.76, P < 0.05), between palm blood flow and plasma vasoactive intestinal polypeptide concentration (r = 0.83, P < 0.05). From these results and our previous data demonstrating increased forearm muscular blood flow in patients with liver cirrhosis, increases in arteriovenous anastomotic flow and the contribution of neurohormonal factors will represent pathophysiological mechanisms for these changes.

Adult↗
PubMed1993

Early ependymal changes in experimental hydrocephalus after mumps virus inoculation in hamsters.

To elucidate the pathogenesis of early ventricular dilatation in hydrocephalus, we examined early morphological changes in ependymal layers at the lateral ventricles in suckling hamsters without aqueductal stenosis 5 days after the intracerebral inoculation of mumps virus. Mumps virus antigen was detectable in all ependymal cells. The ependymal cilia had almost disappeared and only the microvilli remained. A number of supraependymal cells were also observed on the surface of the lateral ventricles. Transmission electron microscopy revealed intracytoplasmic viral-like inclusions in the infected ependymal cells. These results suggest that functional and morphological disturbances in infected ependymal cells may cause early ventricular dilatation before aqueductal stenosis occurs.

Animals↗
PubMed1993

Assignment of human beta-galactosidase-A gene to 3p21.33 by fluorescence in situ hybridization.

GM1 gangliosidosis and Morquio syndrome type B (MPS IVB) are inherited lyosomal storage disorders associated with deficiency of beta-galactosidase-A (beta GALA) activity. A recombinant plasmid containing a biotinylated cDNA (2.4-kb insert) encoding human beta GALA was used to localize the enzyme locus by fluorescence in situ hybridization (FISH). The human beta GALA gene was assigned to 3p21.33 by FISH.

Bisbenzimidazole↗
PubMed1993

Changes in immunohistochemical distribution of cytochrome MC-P-448 in the rat liver during acclimation to cold.

Immunohistochemical localization of cytochrome MC-P-448 (form of cytochrome P-450 induced by methylcholanthrene) in rat hepatic lobule and the changes in their distribution pattern in response to cold exposure at 4 degrees C were investigated. The distribution of hepatocytes expressing immunoreactivity to cytochrome MC-P-448 was demonstrated with rabbit anti-MC-P-448 serum using a microphotomeasurment system P1 (Nikon). A duration of cold exposure for 1, 2, 3 or 4 weeks at 4 degrees C was applied to study the effect of cold adaptation of cytochrome MC-P-448. In control rats housed at 24 degrees C, hepatocytes showing high immunoreactivity to cytochrome MC-P-448 were located in the centrilobular areas of the hepatic lobules, whereas they disappeared markedly in the 4-week cold-exposed rats. In 1-week and 2-week cold-exposed rats, only a slight decrease in the expression of MC-P-448 positive hepatocytes was observed. These changes were clearly seen by visual inspection of the distribution topography as determined by a microphotomeasurement technique. In conclusion, cytochrome MC-P-448 forms which were predominantly located in centrilobular areas in the hepatic lobule decreased in 4-week cold-exposed rats. This was in contrast to our early report which showed an increasing tendency of cytochrome PB-P-450 forms in 4-week cold-exposed rats.

Acclimatization↗
PubMed1993

Abnormal cutaneous vasomotion and reduced cutaneous blood mass remain in congestive heart failure even with normalized cardiovascular hemodynamics.

To elucidate the pathophysiologic role of cutaneous microcirculation in congestive heart failure, finger cutaneous microcirculation was analyzed in 17 patients with acute heart failure (AHF) and 12 patients with hemodynamically compensated heart failure (c-HF) by using laser Doppler spectroscopy; the results were correlated with simultaneously obtained cardiovascular hemodynamics. Mean finger cutaneous blood flow in AHF was significantly lower compared with c-HF (p < 0.01) and control (n = 20, p < 0.001). Mean finger cutaneous blood mass was significantly reduced in both AHF (p < 0.01) and c-HF (p < 0.01) compared with control. Frequency of characteristic giant concave waves indicating sudden occurrence of flow reduction (B wave) was significantly higher in AHF (p < 0.01) and c-HF (p < 0.05) than that in control. Frequency of B waves correlated significantly with pulmonary capillary wedge pressure (PCWP) (r = 0.73, p < 0.01) and pulmonary artery systolic pressure (r = 0.54, p < 0.05). When changes after medical treatments were compared there were significant correlations between changes in B-wave frequency and changes in PCWP (r = 0.89, p < 0.01) and changes in finger cutaneous blood flow and changes in total systemic peripheral resistance (r = -0.75, p < 0.05). Cutaneous microcirculation in AHF was characterized by decreased finger cutaneous blood flow and finger cutaneous blood mass and prominent B waves, which reflected abnormal vasomotion activity. B-wave prominence and reduced finger cutaneous blood mass remained in c-HF even with normalized cardiovascular hemodynamics.

Adult↗
PubMed1993

Characterization of vasopressin-mediated GSH efflux from Hep G2 cells: significance of protein kinase C.

Vasopressin stimulated GSH efflux from Hep G2 cells. The maximal effect was observed at 10nM. Pretreatment with pertussis toxin or cholera toxin for 18 hr increased GSH efflux. Vasopressin-mediated GSH efflux was observed even in the cells pretreated with those compounds. Dibutyryl-cAMP or dibutyryl-cGMP enhanced GSH efflux although an additive effect of vasopressin was not observed. Glucagon and a phorbol ester independently increased GSH efflux while both compounds decreased the effect of vasopressin. Staurosporine, an inhibitor of protein kinase C, inhibited vasopressin-mediated GSH efflux. The effect of vasopressin was observed even in the absence of extracellular Ca2+. Vasopressin stimulates GSH efflux from Hep G2 cells and protein kinase C-dependent pathway may play a significant role in vasopressin-mediated GSH efflux.

Alkaloids↗
PubMed1993

Escape from in vitro aging in SV40 large T antigen-transformed human diploid cells: a key event responsible for immortalization occurs during crisis.

A human diploid fibroblast strain MRC-5 was transfected with a replication origin-defective early region of SV40 containing the gene of large T antigen, and 48 clones of T antigen-transformed MRC-5 were isolated. Although T antigen prolonged the lifespan of MRC-5, all the transformed clones were still mortal. From two of the transformed MRC-5 clones, eight independent immortalized clones were obtained in triple experiments of immortalization. The transformed phenotypes of immortalized clones were widely varied and did not always retain those of the parental pre-immortalized clones. The immortalization occurred at the frequency of about 1-3 x 10(-7)/cell. From cell number and population doubling time of the immortalized clones, the immortalization was estimated to occur in or just before the crisis of parental mortal cells. The decreases of modal chromosome numbers and the loss of chromosomes 5 and 10 were found to be common in three independent immortalized clones examined. Thus, the escape from the cellular aging process seemed to be caused by certain genetic events including the loss of chromosomes at the end of lifespan in T antigen-transformed human diploid cells.

Aneuploidy↗
PubMed1993

Expression of the rat calmodulin gene II in the central nervous system: a 294-base promoter and 68-base leader segment mediates neuron-specific gene expression in transgenic mice.

Deletion analysis of the rat CaMII promoter demonstrated that the segment from -294 to +68 bases of CaMII was efficient as a promoter in NIH3T3 by transient assay. We developed transgenic mice carrying a fusion gene of this promoter segment and a beta-galactosidase reporter gene. This short CaMII promoter mediated the transgene expression in pyramidal cells of the cerebral neocortex, the pyriformcortex and the hippocampal regions CA1 to CA3, in granule cells of the dentate gyrus, in Purkinje cells of the cerebellum, and in neurons of the lateral vestibular nucleus of pons and the spinal cord of adult transgenic mice. The expression of endogenous CaMII was precisely analyzed by in situ hybridization in the nervous tissues. The localization of transgene expression was consistent with those of the endogenous CaMII in the adult transgenic mice. In the embryos at 13.5-15.5 days of gestation, the transgene was expressed in various neurons similarly to the endogenous CaMII but certain subtle differences were observed in the localization of expression. This short promoter of rat CaMII carried two sequence stretches highly conserved in the mouse, dog, chicken and Xenopus CaMII promoters. These conserved stretches may be involved in the observed neuron-specific expression of rat CaMII gene.

Animals↗
PubMed1993

Characterization of a unique scrambled peptide derived from the CD4 CDR3-related region which shows substantial activity for blocking HIV-1 infection.

We have previously identified CD4 peptides that exhibited blocking activity on human immunodeficiency virus type 1 (HIV-1) infection, i.e. CD4(68-130) and CD4(66-92) which include the region corresponding to the third complementarity-determining region of IgG. Here we describe a unique peptide derived from CD4(66-92), altered in amino acid sequence but not in composition, which was found to have increased anti-HIV-1 activity. The acidic amino acid residues in this scrambled peptide, S1, localized at the N-terminus, while in the native peptide they clustered at the C-terminus. On the other hand, a second scrambled peptide, S2, in which the acidic amino acid residues were fully dispersed, did not show any anti-HIV-1 activity. However, we could not identify any correlation between CD4(66-92) and S1 peptides by their hydrophobic or circular dichroism spectrum analyses. The results provide insight into the mechanisms of HIV-1 gp120 and CD4 interaction and may be useful as a new approach to AIDS therapy.

Amino Acid Sequence↗
PubMed1993

Purification and specificity of a cell-wall-associated proteinase from Lactobacillus helveticus CP790.

A cell-wall-associated proteinase from Lactobacillus helveticus CP790, grown in skim milk, was purified to homogeneity by DEAE ion exchange chromatography in the presence of EDTA. Its molecular weight was estimated to be 45,000 by SDS-PAGE and also by the recovery of proteinase activity only from this fraction of SDS-PAGE gel slices of crude extract. It had maximum activity at pH 6.5 and 42 degrees C. Since the activity was completely inhibited by phenylmethanesulfonyl fluoride (PMSF), it was suggested to be a serine-type proteinase. It preferentially hydrolyzed alpha- and beta-casein but did not hydrolyze kappa-casein by the purified enzyme. The 10 main peptides liberated from alpha-casein, and the 15 peptides liberated from beta-casein, were isolated by reversed phase HPLC. These peptides were hydrolyzed by HCl and their amino acid compositions were analyzed and identified. Many of peptides were located in the C-terminal parts of alpha- and beta-casein. Peptide bonds cleaved by the proteinase had no clear specificity but Leu-X, Phe-X, Ser-X, Lys-X, Glu-X, and Gln-X sequences frequently appeared.

Amino Acid Sequence↗
PubMed1993

11q trisomy detected by fluorescence in situ hybridization.

A patient with psychomotor developmental delay, multiple minor anomalies, congenital heart disease and left inguinal hernia is reported. His karyotype was 45,X/46,X,+mar (3:37 cells), and the marker chromosome was identified as t(Y;11)(q12;q14?) using fluorescence in situ hybridization and fluorescent chromosome painting. He was diagnosed as mosaic for de novo 11q trisomy.

Abnormalities, Multiple↗
PubMed1993

A long-term suppression by alpha-interferon of Philadelphia chromosome in children with chronic myelogenous leukemia.

An 8 year old girl with adult type Philadelphia (Ph1)-positive chronic myelogenous leukemia received natural alpha-interferon therapy in the chronic phase. Complete suppression of the Ph1 clone of bone marrow cells was achieved after 1 month of therapy, which was determined by disappearance of rearranged breakpoint cluster region (BCR) gene in Southern blot analysis. Complete hematological remission was also attained following 2 months of therapy. Both the suppression and the hematological remission have been sustained for 24 months with alpha-interferon, in spite of the detection of the chimeric BCR/ABL mRNA in her bone marrow by polymerase chain reaction assay 12 months after therapy.

Amino Acid Sequence↗
PubMed1993

[Interaction of trichloroethylene and isopropyl alcohol in the perfused rat liver].

The interaction of trichloroethylene (TCEL) and isopropyl alcohol (IPA) was studied in the perfused rat liver. Experiments consisted of four parts; TCEL administration with or without IPA, chloral hydrate (CH) administration with or without IPA, IPA administration with or without CH, IPA administration with or without trichloroethanol (TCE). The chemicals were administered into the perfusate of Krebs-Henseleit buffer saturated with 95%O2/5%CO2 in a non-recirculating circuit. Concentrations of the following three metabolites in the effluent were continuously measured by gas chromatograph and chemical methods: TCE and trichloroacetate (TCA) (metabolites of TCEL and CH), and acetone (a metabolite of IPA). Fluorescence from intracellular reduced pyridine nucleotides (NADH, NADPH) was monitored by surface fluorometry. The results showed that IPA changed the TCA/TCE ratio in the TCEL metabolism because of an increase in NADH production, and IPA oxidation was suppressed by CH because of an inhibitory effect of TCE on alcohol dehydrogenase. It was concluded that IPA and TCEL, both ubiquitous agents, interacted with each other in their metabolic pathways in the perfused rat liver, suggesting a new feature of a combined effect of these chemicals when they coexist.

1-Propanol↗
PubMed1993

A case of postpartum hypopituitarism associated with empty sella: possible relation to postpartum autoimmune hypophysitis.

A fifty-year-old woman was admitted to our hospital because of generalized edema, progressive symptoms of fatigue and weakness of ten years' duration. After an uneventful third delivery, 24 years before admission, she could not lactate and developed oligomenorrhea and then amenorrhea. Laboratory evaluation revealed panhypopituitarism and pituitary cell antibodies were positive. Both CT scans and MR images showed empty sella. This case is postpartum hypopituitarism without a preceding history of excessive bleeding and may be autoimmune hypophysitis.

Autoimmune Diseases↗
PubMed1993

The social cost of alcohol abuse in Japan.

In recent years, alcohol-related health and social problems have become a serious concern in Japan because of the marked increase in per capita alcohol consumption. To facilitate forming a well-balanced policy on alcohol, the economic burden of alcohol abuse on Japanese society was estimated and has been presented in this study. In 1987, the alcohol attributable costs of medical care were estimated at 1,095.7 yen billion, representing 6.9% of the total national medical expenditure. The present amount of lifetime economic value based on age and sex for the Japanese population was calculated using the human capital method to estimate the alcohol attributable mortality costs. In 1987 this cost was estimated at 923 yen billion. By applying a 21% reduction rate, reduced productivity related to alcohol abuse was estimated at 4,257.3 yen billion. Summing up the costs of each component of the overall cost to society, the total cost of alcohol abuse was estimated at 6,637.5 yen billion, representing 1.9% of the gross national product in 1987, which was three times that of the national revenue from taxes on alcohol beverages. Along with the increase in city living, the economic burden of alcohol abuse on our society is expected to rise considerably. Public health intervention urgently needs to be administered in order to reduce the number of alcohol-related health and social problems.

Adolescent↗
PubMed1993

Effects of 24-hour shift work with nighttime napping on circadian rhythm characteristics in ambulance personnel.

Forty-two ambulance personnel engaged in a 24-h shift system participated in a chronobiological field study to study the effects of 24-h shift work on circadian rhythm characteristics. Autorhythmometry of circadian rhythms of oral temperature, right and left grip strengths, and heart rate plus subjective assessment of drowsiness, fatigue, and attention was performed every approximately 4 h except during sleep for 7 days. Cosinor and power spectral analyses were applied to the longitudinal data of each individual. Changes in circadian period different from 24 h of oral temperature, grip strengths, and heart rate plus subjective drowsiness, fatigue, and attention were observed in ambulance personnel. The incidence of circadian periodicity different from 24 h in oral temperature and right and left grip strength was 28.6%, 35.7%, and 47.6%, respectively. The incidence was relatively lower than that of shift workers engaged in a discontinuous 8-h shift system we reported on previously. Working conditions allowing ambulance personnel to nap when not called for emergency (for > 4 h) might contribute to a stabilization of circadian rhythms. Furthermore, long nighttime ambulance service amounting to > 100 min was significantly associated with a high incidence of at least one prominent circadian period among oral temperature and right and left grip strength rhythms different from 24 h. In conclusion, 24-h shift work altered the characteristics of circadian rhythms of ambulance personnel; nighttime naps seemed to have a favorable effect on averting changes in circadian rhythms.

Adult↗