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Biomedical subjects

H Sano

Publications and source records attributed to H Sano.

At least 415 records · Page 23Linked to original sources
PubMed1994

Local secretion of corticotropin-releasing hormone by enterochromaffin cells in human colon.

BACKGROUND/AIMS: Corticotropin-releasing hormone (CRH) is a regulator of the hypothalamic-pituitary-adrenal axis and a coordinator of the gastrointestinal response to stress. In addition to its central effects, CRH has peripheral effects on the immune system. CRH is present in several human tissues, such as the brain, spinal cord, adrenal medulla, lung, liver, peripheral blood leukocytes, as well as the gastrointestinal tract. The current study examined the local production of CRH in the normal human colon. METHODS: Normal human colonic tissues obtained by endoscopic biopsy were immunostained with anti-CRH and anti-5-hydroxytryptamine antibody and analyzed for CRH messenger (m)RNA by a reverse-transcribed polymerase chain reaction method and by in situ hybridization. RESULTS: Immunoreactive CRH and CRH mRNA were detected in the colonic mucosal cells in the neighborhood of the base of the crypts. The mucosal cells that expressed CRH mRNA also immunostained with anti-5-hydroxytryptamine antibody. CONCLUSIONS: Normal human colonic mucosal enterochromaffin cells produce CRH. CRH in the colonic mucosa may play a role in the modulation of the intestinal immune system and/or other gastrointestinal functions basally during stressful conditions.

Adolescent↗
PubMed1994

Relationship between surface area for adhesion and tensile bond strength--evaluation of a micro-tensile bond test.

OBJECTIVES: The purpose of this study was to test the null hypothesis that there is no relationship between the bonded surface area of dentin and the tensile strength of adhesive materials. METHODS: The enamel was removed from the occlusal surface of extracted human third molars, and the entire flat surface was covered with resin composite bonded to the dentin to form a flat resin composite crown. Twenty-four hours later, the bonded specimens were sectioned parallel to the long axis of the tooth into 10-20 thin sections whose upper part was composed of resin composite with the lower half being dentin. These small sections were trimmed using a high speed diamond bur into an hourglass shape with the narrowest portion at the bonded interface. Surface area was varied by altering the specimen thickness and width. Tensile bond strength was measured using custom-made grips in a universal testing machine. RESULTS: Tensile bond strength was inversely related to bonded surface area. At surface areas below 0.4 mm2, the tensile bond strengths were about 55 MPa for Clearfil Liner Bond 2 (Kuraray Co., Ltd.), 38 MPa for Scotchbond MP (3M Dental Products), and 20 MPa for Vitremer (3M Dental Products). At these small surface areas all of the bond failures were adhesive in nature. SIGNIFICANCE: This new method permits measurement of high bond strengths without cohesive failure of dentin. It also permits multiple measurements to be made within a single tooth.

Composite Resins↗
PubMed1994

Recombinant human granulocyte colony-stimulating factor augments cytotoxicity of OK-432-induced polymorphonuclear leukocytes.

Polymorphonuclear leukocytes (PMNs) recovered from the peritoneal cavity of mice treated with the streptococcal preparation OK-432, exhibited strong cytotoxicity after the in vitro addition of Nocardia rubra cell wall skeleton (N-CWS). In this study, we investigated whether recombinant human granulocyte colony-stimulating factor (rhG-CSF) could augment the cytotoxicity of OK-432-induced PMNs after the addition of N-CWS in vitro. PMNs recovered from the peritoneal cavity of 8- to 10-week-old, male C3H/He mice induced by intraperitoneal (i.p.) injection of 50 KE/kg (1 KE = 0.1 mg) of OK-432 were used in a 51Cr release assay against MM46 mammary carcinoma cells. While addition of rhG-CSF in vitro did not augment the cytotoxicity of OK-432-induced PMNs, marked augmentation of the cytotoxicity of OK-432-induced PMNs was observed following a single subcutaneous (s.c.) or i.p. injection of 125 micrograms/kg of rhG-CSF. The effect of in vivo administered rhG-CSF was dependent on the timing of the injection with respect to OK-432 administration and differed from s.c. or i.p. injections. Interestingly, the cytotoxicity of OK-432-induced PMNs was rather weak following consecutive s.c. or i.p. administration of rhG-CSF for 7-14 days. H2O2 is likely involved in mediating the cytotoxicity of OK-432-induced PMNs since activity was significantly reduced by the in vitro addition of low concentration of catalase. Generation of H2O2 by the PMNs correlated with cytotoxicity. These results suggest that in vivo administration of rhG-CSF augments the cytotoxicity of OK-432-induced PMNs in a time dependent fashion and that H2O2 plays an important role in mediating their cytotoxicity.

Animals↗
PubMed1994

Circadian variations in plasma monoamine metabolites level in alcoholic patients: a possible predictor of alcohol withdrawal delirium.

1. Alcohol withdrawal symptoms in 17 alcoholics were classified into two groups according to the severity of their symptoms, and circadian variations in their plasma 5-hydroxyindoleacetic acid (5HIAA) and homovanillic acid (HVA) levels during the alcohol withdrawal and the abstention periods were compared with those in normal controls by two-way ANOVA. 2. Circadian variations in plasma 5HIAA level in alcoholic patients manifested severe alcohol withdrawal symptoms and exhibited phase advances in both the withdrawal and the abstention periods and significantly higher levels in the abstention period. 3. Circadian variation in plasma HVA in the abstention period in alcoholics showed severe withdrawal symptoms demonstrating significantly higher levels compared with normal controls. 4. These findings suggest that the serotonergic and dopaminergic activity may vary depending on the severity of alcohol withdrawal symptoms and the measurement of circadian variations in plasma 5HIAA and HVA levels could possibly be used as a predictor of hardly predictable alcohol withdrawal delirium.

Adult↗
PubMed1994

Cloning and nucleotide sequencing of a 15 kb region of the Bacillus subtilis genome containing the iol operon.

Within the framework of an international project on the sequencing of the whole Bacillus subtilis genome, a 15 kb chromosome segment, which contains the iol operon involved in inositol utilization, has been cloned and sequenced. This region (14,974 bp) contains 12 complete open reading frames (ORFs; genes) and two partial ones; the seventh gene (E83G) is the idh gene encoding inositol dehydrogenase. All the genes identified are transcribed in the same direction as that of the movement of the replication fork. A homology search for their products deduced from the 12 complete ORFs revealed that eight of them exhibit significant homology to known proteins such as fructokinase, acetolactate synthase, fructose-1,6-bisphosphate aldolase (B. subtilis), and PhoB and FtsE proteins (Escherichia coli). It also implied that two genes (B65D and B65E) might encode a set of two-component regulatory proteins and that the B65F gene might encode a protein belonging to the ATP-binding cassette (ABC) family. Based on the features of the nucleotide sequence determined and the results of the homology search, the primary structure of the iol operon is predicted.

Amino Acid Sequence↗
PubMed1994

The middle-aged generation is at high risk for suicide in Japan. A comparison between the 1950s and the 1980s.

The suicide rate in Japan was the highest in the world the 10 years after World War II. There were many suicides among young and aged people. Now, Japan has many suicides among middle-aged people, and suicides among elderly people are still remarkable. These findings suggest that middle-aged people in 1980s have a high risk of suicide and that suicide among elderly people will increase in 10-20 years.

Adolescent↗
PubMed1994

Circadian and estrous cycle-dependent variations in blood pressure and heart rate in female rats.

To determine whether cardiovascular functions are controlled by the endogenous circadian system and whether they change with the estrous cycle in female rats, we measured mean arterial pressure (MAP), heart rate (HR), and spontaneous activity (ACT) of female rats using an implantable radiotelemetry device and a computerized data-collecting system. Under a 12:12-h light-dark (LD) cycle, these parameters exhibited daily rhythms that were entrained to the photic cycle. The patterns of the daily rhythms varied with estrous cycles, and variations were particularly marked in the proestrous stage. During the dark period of this stage, ACT levels were significantly higher, but HR was significantly lower than in other stages. Although the peak MAP occurred within 2 h after the onset of the dark phase in three of the estrous stages, it occurred around midnight in the proestrous stage. Such estrous cycle-dependent variations were eliminated by ovariectomy. The implantation of 17 beta-estradiol produced a gradual increase in MAP and an abrupt decrease in HR. During constant darkness, all three parameters were free running, maintaining the same internal phase relationships with each other as during LD cycles. These results indicate that daily variations in these parameters were controlled by the endogenous circadian oscillating system, that they vary with the estrous cycle in female rats, and that estrogen may be responsible for these estrous cycle-dependent variations.

Analysis of Variance↗
PubMed1994

Cyclooxygenase-1 and -2 expression in rheumatoid synovial tissues. Effects of interleukin-1 beta, phorbol ester, and corticosteroids.

High levels of immunoreactive cyclooxygenase (Cox; prostaglandin H synthase) are present in synovia from patients with rheumatoid arthritis (RA). We now show that the recently identified inducible isoform of Cox, Cox-2, is expressed in synovia from patients with RA. To further explore modulation of the Cox isoforms in RA synovial tissues, we examined the expression and modulation of Cox-1 and -2 in rheumatoid synovial explant cultures and cultured rheumatoid synovial fibroblast-like cells (synoviocytes). Immunoprecipitation of in vitro labeled proteins and Western blot analysis demonstrated the presence of both Cox-1 and -2 under basal conditions in freshly explanted rheumatoid synovial tissues. De novo synthesis of Cox-2 polypeptide was enhanced by IL-1 beta or PMA, and dramatically suppressed by dexamethasone (dex). Cox-1 expression, under the same conditions, showed only minor variation. Since mRNA for Cox-2 is highly unstable, we examined the regulation of Cox-2 transcripts in cultured rheumatoid synoviocytes. Under basal conditions both Cox-1 and -2 mRNAs were present at low levels, but Cox-2 mRNA was markedly increased by treatment with IL-1 beta or PMA. dex markedly suppressed the induction of Cox-2 mRNA. In sharp contrast, Cox-1 transcripts were not modulated by IL-1 beta or dex. These data suggest that modulation of Cox-2 expression by IL-1 beta and corticosteroids may be an important component of the inflammatory process in synovial tissues from patients with RA.

Adrenal Cortex Hormones↗
PubMed1994

Tensile properties of mineralized and demineralized human and bovine dentin.

The relative contribution of the matrix of dentin to the physical properties of dentin is unknown but thought to be small. The objective of this study was to test the hypothesis that the demineralized matrix of dentin contributes little to the strength of dentin by measuring and comparing the ultimate tensile strength and modulus of elasticity of mineralized and demineralized dentin. Small slabs (4 x 0.5 x 0.5 mm) of bovine and human dentin were tested in a microtensile testing device in vitro. Human coronal mineralized dentin gave a mean ultimate tensile strength (UTS) of 104 MPa. Bovine incisor coronal dentin exhibited a UTS of 91 MPa, and bovine root dentin failed at 129 MPa. The modulus of elasticity of mineralized bovine and human dentin varied from 13 to 15 MPa. When dentin specimens were demineralized in EDTA, the UTS and modulus of elasticity fell to 26-32 MPa and 0.25 GPa, respectively, depending on dentin species. The results indicate that collagen contributes about 30% of the UTS of mineralized dentin, which is higher than was expected.

Animals↗
PubMed1994

Possible functional groups responsible for inhibition of in vivo angiogenesis by herbimycin A.

Six herbimycin A (HBM) derivatives were examined for their anti-angiogenic effects in a bioassay system involving chorioallantoic membranes (CAMs) of growing chick embryos on the basis of our previous observation that HBM is a potent angiogenesis inhibitor. 17-Cyclopropylamino-HBM dose-dependently inhibited embryonic angiogenesis. The ID50 value was 0.1 microgram (160 pmol) per egg and thereby lower than that of the parent compound HBM (ID50 = 0.15 micrograms (260 pmol) per egg). In contrast, 19-dimethylamino-, N-acetyl-, 2,3,4,5-tetrahydro- and 7-decarbamoyl-HBM at doses of 0.01-10 micrograms/egg failed to affect angiogenesis in CAMs. These results strongly suggest as follows: (1) C-19 position, amino group between positions C-1 and C-20 and carbamoyl group in C-7 are essential for the anti-angiogenic action of HBM; (2) HBM needs certain fixed conformation for expression of angiogenesis inhibition; (3) it is expected that the modification of C-17 with a suitable functional group results in increased anti-angiogenic potency of HBM--that is, a more potent angiogenesis inhibitor than the parent compound would be developed.

Allantois↗
PubMed1994

Investigation of pure-tone hearing levels at a single frequency in sudden deafness.

Hearing levels in patients with sudden deafness are commonly discussed in terms of average thresholds at 3 or 5 frequencies, but an investigation of hearing levels at a single frequency is also important. In this paper, pure tone thresholds at 500 Hz and 4,000 Hz were investigated in patients with sudden deafness who came to our clinic within 4 days of onset. Particular attention was paid to the relationship between audiometric types according to the contour of the initial loss and degree of hearing recovery at each frequency. In the group of patients whose initial hearing level at 500 Hz was between 55 and 70 dB, the hearing recovery at 500 Hz in the upward slope type was significantly greater than that in the downward slope type, but in other groups no significant differences in hearing recovery were observed among the different types of initial audiograms. We considered that the hearing recovery at a single frequency was not related to the audiometric type except in the patients with the upward slope type with moderate hearing loss.

Adolescent↗
PubMed1994

Sudden deafness accompanied by asymptomatic mumps.

In this study we investigated asymptomatic mumps as a possible cause of sudden deafness. We studied 131 sudden deafness patients by measuring their serum mumps antibody values. Positive IgM antibody results, which strongly suggest recent mumps infection, were revealed in 9 of the 130 patients tested (6.9%). Asymptomatic mumps infections are apparently closely related to sudden deafness. Further studies will provide more definite diagnoses of mumps deafness and might be applicable to the treatment of such hearing loss.

Adolescent↗
PubMed1994

Study on the distribution of hearing levels in idiopathic bilateral sensorineural hearing loss.

The pattern of aggravation in hearing was investigated in 105 patients who were diagnosed as having idiopathic bilateral sensorineural hearing loss at the Hearing Loss Clinic, Department of Otolaryngology, Kitasato University Hospital. Audiograms were taken 1,069 times from the 105 cases over more than 3 years, and were used to obtain the distribution of hearing levels at each test frequency. The clinical course of idiopathic bilateral sensorineural hearing loss was divided into three stages: Stages I, II and III, based on the pattern of aggravation. The pattern of distribution of hearing levels at different stages was compared with each other with reference to peaks or clustering points. Similar peaks were noted at Stage II and Stage III as aggravation proceeded from Stage I. Another peak was noted in the zone of scale-out.

Adolescent↗
PubMed1994

Transient deafness with iopamidol following angiography.

A case of transient, severe sensorineural hearing loss with iopamidol following angiography is reported. The 26-year-old woman had previously been diagnosed with Arnold-Chiari malformation, and underwent vertebral angiography by a retrograde transfemoral catheterization. Immediately following the second injection of iopamidol she did not react on the nurse's call. An ABR revealed no response in either ear even when the click intensity was 105 dB. The patient was immediately treated with steroid and OHP. Fortunately, 24 h after the angiography she was able to communicate at a normal conversation level. Transient severe sensorineural hearing loss is thought to result from bilateral anoxia of the cochlea due to hypoplasia of the basilo-vertebral artery systems. Cochlea anoxia lasts 10-20 min after which the hearing loss is recovered.

Adult↗
PubMed1994

Absorption mechanism of polaprezinc (zinc L-carnosine complex) by an everted sac method.

1. The absorption mechanism of polaprezinc (zinc-carnosine chelate compound) was studied in rat by an everted gut sac method. The rates of transport and accumulation of 14C-L-carnosine were proportional to the mucosal concentration of L-carnosine, whereas the rates of transport and accumulation of 65ZnCl2 had become saturated. The Michaelis-Menten constant (Km) = 4.41 mM and maximal rate (Vmax) = 71.83 nmol/min/g for zinc transport and, similarly, Km = 6.21 mM and Vmax = 92.51 mumol/30 min/g for accumulation. 2. The addition of ouabain, 2,4-dinitrophenol (2,4-DNP) and low temperatures reduced the rate of zinc uptake, indicating that zinc transport was considered to be a carrier-mediated process based on Na+,K(+)-ATPase-dependent mechanisms. 3. The concentration of zinc in the gut of the non-fasted rat was greater than that of the fasted rat, suggesting different rates of transport and accumulation. It is suggested that zinc intestinal uptake in rat is regulated by zinc content in the gut. 4. A pharmacokinetic model for transport and accumulation of zinc saturation from the lumen side to the gut was designed, and the calculated values obtained by simultaneous multiline fitting of transport and accumulation of zinc data were in good agreement with the observed values.

Animals↗
PubMed1994

Carrier-mediated active transport of histamine H2 receptor antagonists, cimetidine and nizatidine, into isolated rat hepatocytes: contribution of type I system.

The uptake rates of [3H]cimetidine and [14C]nizatidine into isolated rat hepatocytes were studied in order to identify the transport mechanism of histamine H2 receptor antagonists into the liver. In addition, the contributions of the uptake clearance to hepatic clearance for both drugs also were estimated. The uptakes of cimetidine and nizatidine achieved equilibrium in 5 min with cell-to-medium concentration ratios of 12.0 and 3.5, respectively. The uptake systems of both histamine H2 antagonists consisted of a saturable component and a nonsaturable component. The contributions of the carrier-mediated transport system for cimetidine and nizatidine at therapeutic concentrations (3 microM) were 86 and 70%, respectively. The uptakes of both drugs showed temperature dependency and were decreased significantly by various metabolic inhibitors and a sulfhydryl group modifying reagent. Only a slight effect was seen in the replacement of sodium with lithium on both uptakes. The uptake of cimetidine was reduced markedly in parallel with the reduction in the cellular ATP level and was inhibited by other histamine H2 antagonists and various organic cations. Furthermore, both nizatidine and quinidine competitively inhibited cimetidine's uptake. These results demonstrate that cimetidine and nizatidine are taken up into hepatocytes by a common Na(+)-independent transport system, namely the type I organic cation uptake system. By comparing the in vitro hepatic uptake clearance obtained from this study and the in vivo hepatic clearance from pharmacokinetic data, it is suggested that the rate-limiting step in hepatic clearance for cimetidine is drug metabolism, whereas for nizatidine, it is the uptake process.

Adenosine Triphosphate↗