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Biomedical subjects

I Suzuki

Publications and source records attributed to I Suzuki.

At least 91 records · Page 5Linked to original sources

Effect of guarana on exercise in normal and epinephrine-induced glycogenolytic mice.

The tonic action of water Guarana extract, (Paullinia cupana MART.), was investigated in normal, exercised, and epinephrine-induced glycogenolytic mice. A water extract of Guarana (GW) (500 mg/kg) increased the blood glucose level (p < 0.001) and decreased the liver glycogen contents of mice 60 min after oral maltose administration (p < 0.05). GW also significantly suppressed exercise-induced hypoglycemia (60 min: p < 0.05). However, GW did not affect the blood glucose in epinephrine-induced glycogenolytic and exercise mice. These findings indicate that the suppressive mechanism of hypoglycemia might be due to the promotion of glycogen resolution.

Animals↗

Reliability and validity of a questionnaire for assessment of energy expenditure and physical activity in epidemiological studies.

A self-administered physical activity questionnaire (PA-questionnaire) was developed to assess daily energy expenditure and weekly physical activity in epidemiological studies. The Calorie Counter method (CC-method) was administered to 49 male and 32 female volunteers aged 18-64 years, on 7 consecutive days; after the measurement, the subjects were asked to complete the PA-questionnaire (validation study). The PA-questionnaire was completed by 95 males and 119 females (aged 35-73 years) twice with one-year interval (reliability study). The validation study showed that the mean daily energy expenditure estimated by the PA-questionnaire was slightly and significantly (4.5%) lower than that determined by the CC-method for males (p < 0.05); while no significant difference was observed for females (p > 0.05), mean weekly physical activities were similar between the PA-questionnaire and CC-method in males and females. Daily energy expenditures by the two methods strongly correlated with each other: r = 0.56 (p < 0.001) in males and r = 0.67 (p < 0.001) in females. Weekly physical activities by the two methods also strongly correlated with each other: r = 0.68 (p < 0.001) in males and r = 0.69 (p < 0.001) in females. The reliability study indicated that the Pearson's correlation coefficients between two assessments of daily energy expenditure and weekly physical activity over one-year ranged from 0.37 to 0.62 (p < 0.001). These data indicate that the PA-questionnaire has adequate levels of validity and test-retest reliability in assessment of daily energy expenditure and weekly physical activity in epidemiological studies.

Adult↗

Production of gamma-aminobutyric acid by cheese starters during cheese ripening.

Nine mixed-strain starters were examined for their abilities to produce gamma-aminobutyric acid. Six commercial starters were found to produce gamma-aminobutyric acid in a skim milk culture. The bacterium that produced gamma-aminobutyric acid was isolated from the mixed-strain starters, identified as citrate-utilizing Lactococcus lactis ssp. lactis (formerly L. lactis ssp. lactis biovar diacetylactis) and designated as strain 01-7. A cell extract showed glutamate decarboxylase activity, for which the optimum pH was 4.7. In pH-controlled cultivation, gamma-aminobutyric acid was generated at pH 5.0 but not above pH 5.5. Cheeses were prepared experimentally using strain 01-7 to determine the relationship between the pH values and the production of gamma-aminobutyric acid during cheese ripening. gamma-Aminobutyric acid increased linearly in the experimental cheeses as the pH of the cheese decreased. Based on these results, gamma-aminobutyric acid was concluded to be produced by the cheese starters during ripening.

Cheese↗

Diminished reproduction, failure to thrive, and altered immunologic function in a colony of T-cell receptor transgenic mice: possible role of Citrobacter rodentium.

Citrobacter rodentium from an undetermined source was detected in a breeding colony of T-cell receptor transgenic mice housed in a conventional mouse facility in which murine hepatitis virus had been endemic and Helicobacter spp. had been detected. Citrobacter rodentium, isolated from blood, spleen, and colon, correlated with a significant increase in mortality and morbidity in this breeding colony. Transgenic mice of all ages were affected by chronic debilitation, loss in reproductive efficiency, rectal prolapse, and acute death, resulting in the near loss of these noncommercially available strains. Several alterations in immunologic parameters were observed, including outgrowth of an unusual population of cells in the spleen and blood, reduction in ascites production, loss of the capacity of peritoneal exudate cells to serve as feeders for the cloning of long-term T-cell lines, and inhibition of antigen-specific cytotoxic T-cell activity. These altered immune functions also were apparent in commercially-derived nontransgenic mice cohoused with the infected colony and in overtly healthy transgenic and nontransgenic littermates. Citrobacter rodentium and murine hepatitis virus were eliminated ultimately on rederivation of the affected strains by embryo transfer. However, the rapid decrease in the health of the colony necessitated more immediate action. To reduce mortality and allow breeding to continue during rederivation of the transgenic lines, animals were treated with enrofloxacin and moved to a barrier facility. Antibiotic therapy significantly reduced morbidity and mortality, markedly increased litter size and frequency, and resulted in the normalization of many of the immunologic assays. The involvement of C. rodentium in altering viability of the colony and perturbing immunologic assays is suggested by correlation of the onset of the syndrome with the appearance of Citrobacter sp. and its resolution with the elimination of Citrobacter sp. from the colony. Whether infection with Citrobacter alone is causative or whether superinfection of murine hepatitis virus- and Helicobacter-infected mice is required remains to be determined.

Animals↗

[Neonatal intracranial tumor highly suspected of teratoma in the lateral ventricle consisting of multiple cysts: case report].

Neonatal intracranial teratoma is rare and early attempts at surgical treatment are not usually successful. We describe an exceptionally rare case of neonatal intracranial tumor in the lateral ventricle composed of multiple cysts with little mass content which was highly suspected of teratoma and treated successfully by microsurgery. A 55-day-old male was admitted to our hospital with complaints of convulsive seizure. Examination found no obvious neurological deficit except mild enlargement and bulging of anterior fontanel. There were no abnormal laboratory findings. Computerized tomography with contrast medium revealed an 8 cm multicystic lesion with little mass content in the right lateral ventricle and hydrocephalus. Magnetic resonance imaging showed the cystic content as slightly higher in intensity than CSF on the T1-weighted image and of higher intensity than CSF on the T2-weighted image. The cyst wall was enhanced on T1-weighted image with gadolinium. The aqueduct was obstructed by compression due to the intraventricular cyst. A right occipitoparietal craniotomy was performed, which disclosed a hair in the cyst wall, two huge cysts, and independence of the intracystic lesion from the lateral ventricle. The tumor was removed except for a small part adjacent to the pineal region, from which the tumor had presumably originated. Mature teratoma was highly suspected on the basis of the hair in the cyst wall and histological examination of the specimen, which revealed hamartomatous tissues derived from two germ cell layers. After surgery, his hydrocephalus was improved and convulsive seizures were reduced remarkably. He was discharged ten days later and is being followed up. Reoperation will be performed if regrowth of the residual tumor occurs.

Cerebral Ventricle Neoplasms↗

Endothelin-1 is a paracrine growth factor that modulates melanogenesis of human melanocytes and participates in their responses to ultraviolet radiation.

Endothelin (ET)-1, alpha-melanocyte stimulating hormone (alpha-melanotropin; alpha-MSH), and basic fibroblast growth factor (bFGF) are keratinocyte-derived factors that interact synergistically to stimulate human melanocyte proliferation. ET-1 has a dose-dependent mitogenic effect on human melanocytes and a biphasic effect on melanogenesis: a stimulatory effect at subnanomolar concentrations, and an inhibitory effect at concentrations equal to or higher than 1 nM. Human melanocytes express ET B receptors. Brief treatment of melanocytes with ET-1 caused up-regulation of alpha-MSH receptor mRNA but did not alter ET B receptor mRNA level. ET-1 modulates the response of human melanocytes to UV rays (UVRs). Treatment of melanocytes with 10 nM ET-1 immediately after exposure to UVRs enabled them to overcome the G1 growth arrest. However, ET-1 did not inhibit p53 accumulation or p21(Waf-1/SDI-1/Cip-1) overexpression, nor did it reverse the hypophosphorylated state of pRb or the reduction in Bcl2 level in irradiated melanocytes. These results substantiate the role of ET-1 as a paracrine regulator that modulates the response of human melanocytes to UVRs.

Cell Division↗

[Clinical experience of autologous blood transfusion and fibrin glue in neurosurgery].

Clinical experience of autologous blood preservation on 83 patients and transfusion on 43 patients were reported. When drawing blood, 14 patients whose hemoglobin level was below 13 g/dl (body weight < 70 kg) or 14 g/dl (body weight > 70 kg) received subcutaneous recombinant human erythropoietin injection (s.c.) to facilitate erythropoiesis, according to the internal standard protocol. Hemoglobin levels of all the patients recovered to more than 10 g/dl by the time they were admitted to the hospital, which value would not interfere with general neurosurgical procedures. The injection of erythropoietin did not cause any side effects. Autologous blood transfusion was performed in 43 patients but, in 3 patients, additional homologous transfusion was required because of excessive bleeding. Except in cases with meningioma, postoperative hemoglobin values were identical with preoperative values, indicating that autologous blood transfusion was enough to replace intraoperative blood loss. Autologous fibrin glue was applied in 74 patients. In 70 cases including 55 with skull base surgery, the glue was applied to ensure dural closure. The incidence of cerebrospinal fluid leakage was 16.4% (5 patients) in skull base surgery. This incidence was identical to or less than that in previous reports. The glue was also effective in transposing and fixing offending vessels in 4 cases which received microvascular decompression. As a conclusion, procedures for autologous blood preservation and transfusion were safely performed in neurosurgical cases. Review of the literature was also presented to discuss the advantages and problems to be solved in the future.

Adolescent↗

[A study of neuroleptic malignant syndrome in the presenium and senium].

Recently, with the increase in elderly population, we have had more opportunities to administer neuroleptics to elderly patients for hallucinatory delusional state, delirium, psychomotor excitement, wandering etc. However, little is known about the characteristics of the neuroleptic malignant syndrome (NMS) in elderly patients, which is the most serious side effect of neuroleptics. In this paper, we present the clinical course of five NMS patients in the presenium and senium. Case 1 was 72-year-old male who was diagnosed as having dementia of Alzheimer's type (with late onset). He showed nocturnal wandering, insomnia, and irritability. Tiapride 60 mg per day had been administered previously. Just after the addition of oxypertine 10 mg per day, NMS occurred, and he died of pneumonia a week later. Case 2 was 75-year-old male who was diagnosed as having vascular dementia. He showed insomnia, hyperactivity and wandering. He had been given levomepromazine (LPZ) 10 mg per day over a long period of time. At first, he had daily episodic fever, however, serum CPK levels did not increase at that time. A month later, all the symptoms of NMS appeared and then the patient's condition suddenly deteriorated and he died three days later. Case 3 was a 64-year-old male who was diagnosed as having dementia of Alzheimer's type (with early onset). He showed insomnia, irritability and violence. Tiapride 50-125 mg per day was administered along with oxypertine 50-115 mg per day. Almost two months later, NMS occurred. He had daily episodic fever at first, extrapyramidal symptoms and autonomic instabilities gradually increased. Soon after symptoms of NMS were completed. In this case, NMS seemed to be induced by bacterial pneumonia after long term administration of LPZ 5 mg per day. Case 4 was a 75-year-old female who was diagnosed as having dementia of Alzheimer's type (with late onset). She showed hallucinatory delusional state. Although she had autonomic instabilities just after adminstration of haloperidol 1-2 mg per day, NMS itself occurred after discontinuing the neuroleptic. Case 5 was a 61-year-old female who was diagnosed as having schizophrenia at the age of forty. She was given various neuroleptics over a period of time. The neuroimaging in SPECT showed her cerebral cortex was generally hypoactive. She had a tendency to have autonomic instabilities after the administration of relatively high potential neuroleptics. Risperidone 3-6 mg per day was administered, and almost a month later, autonomic instabilities increased and she was diagnosed as having NMS. All the patients would be able to have brain dysfunction, which suggested that such patients may be liable to NMS. In our patients, NMS occurred after the additional administration of oxypertine 10 mg per day or after long time administration of LPZ 5 mg per day. It was suggested that NMS could occur after the administration of low dose and relatively low potential neuroleptics in elderly patients. Our 3 of 5 patients showed the delayed type of NMS, which might be relatively more frequent in senior and presenior patients than in younger patients. In case 3, NMS was induced by the somatic disease (bacterial pneumonia), however in other cases, NMS was not always induced by somatic disease. Our 4 of 5 patients experienced some of the symptoms of NMS--episodic fever, extrapyramidal symptoms and autonomic instabilities--before the onset of NMS. Such symptoms may be "pre-steps" to NMS. Once NMS occurred, the patient's systemic condition tended to deteriorate acutely. Due to the fact that our 2 of 5 patients died, it was suggested that the prognosis of the NMS patients in presenium and senium tends to be much worse. It is important to find the "pre-steps" to NMS and treat them as soon as possible for better prognosis.

Aged↗

Cardiovascular fitness, physical activity and selected coronary heart disease risk factors in adults.

BACKGROUND: The aim was to investigate the associations between cardiovascular fitness and physical activity, and their relationship to selected coronary heart disease (CHD) risk factors. METHODS: This was a cross-sectional study for one week. All participants were Japanese living in the City of Toyota, Japan. Two hundred and twenty-two healthy Japanese (104 men and 118 women), with ages between 20 and 62 years old. Cardiovascular fitness (VO2max) was measured by a progressive submaximal bicycle ergometry test. Physical activity was estimated by an accelerometers attached to the subject's waist for one week, CHD risk factors included blood pressure, fasting levels of blood lipids, and apolipoprotein concentrations. RESULTS: Cardiovascular fitness and physical activity were positively related (r = 0.41 in men and 0.65 in women). For both genders, Pearson coefficients as well as age-adjusted partial correlations indicated that fitness was more closely linked to CHD risk factors than activity was. Also, CHD risk factors were analyzed by three groups of fitness and activity levels in both genders, which indicates that subjects who are physically fitter and/or more active tend to have better CHD risk profiles. CONCLUSIONS: As favorable CHD risk profile was related to cardiovascular fitness, but not to physical activity in both genders, it can be concluded that fitness may be a more important independent predictor for CHD risk factors than activity measured by accelerometer over one week.

Adult↗

Inhibitory effects of oleic and docosahexaenoic acids on lung metastasis by colon-carcinoma-26 cells are associated with reduced matrix metalloproteinase-2 and -9 activities.

In order to determine the effects of single unsaturated fatty acids (UFAs) or combinations on establishment of lung metastatic colonies, UFAs were administered orally to CDF1 mice bearing s.c. implants of the highly metastatic colon carcinoma 26. Oleic acid (OA), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) demonstrated significant inhibition. In the case of DHA, this inhibitory potential was markedly reduced by co-administration of linoleic acid (LA) or EPA. Furthermore, while tumor cells treated with DHA showed a very low potential for lung colony formation when injected i.v., this again being partially reversed by co-administration of EPA. UFAs were found to be well absorbed into tumor tissues after oral administration, causing marked changes in relative levels, the arachidonic acid (AA) content, in particular, being markedly decreased by treatment with DHA or EPA, but not with DHA plus EPA or with DHA plus LA. Investigation of the gelatinolytic activity of the 57-kDa and 92-kDa isoforms of type-IV collagenase (MMP-2 and MMP-9, respectively) showed a clear reduction in the former by treatment with OA, while DHA, but not DHA plus LA or EPA, caused a decrease in the 92-kDa isoform, which was well correlated with AA content in tumor tissues (r = 0.900, p < 0.001). These results suggest that inhibition of metastasis due to treatment with OA and DHA might be due to depressed type-IV collagenase activity.

Animals↗

The N-terminal sequence of Lactococcus lactis phosphoglucose isomerase purified by affinity chromatography differs from the other species.

A specific monoclonal antibody, M3A, was produced to rapidly purify Lactococcus lactis phosphoglucose isomerase (PGI) for amino acid sequence analysis. M3A recognized the Lac. lactis PGI specifically and sensitively with both enzyme-linked immunosorbent assay and Western blot analysis. The enzyme was rapidly purified to a specific activity of 21.8 U/mg with a yield of 20% by a three-step procedure, including M3A-bound Sepharose chromatography. The specific activity of PGI was increased about 64.1-fold from the cell lysate. The molecular mass of Lac. lactis PGI was estimated to be about 50 kDa by SDS-PAGE. The N-terminal amino acid sequence of Lac. lactis PGI exhibited no significant similarity to other PGIs, except for a 52.6% identity to Bacillus stearothermophilus PGI A and PGI B. These results suggest that there might be some molecular types of PGI.

Amino Acid Sequence↗

Nucleotide sequence of a nicking site of the Streptomyces plasmid pSN22 replicating by the rolling circle mechanism.

A putative nicking site in the double strand origin (DSO) of the Streptomyces plasmid pSN22 was identified by comparing the nucleotide sequence of the DSO region with those of two other Streptomyces plasmids, pIJ101 and pJVI. A 7-bp sequence of this putative nicking site, 5'-CTTGGGA-3', was similar to the consensus sequence of the nicking site of the pC194 group of plasmids. When several point mutations were introduced into this 7-bp sequence, the transformation abilities of the mutant plasmid molecules for Streptomyces lividans were either reduced or lost. Southern hybridization analysis indicated that these mutant plasmids could not replicate in S. lividans, but were integrated into the chromosomal DNA.

Base Sequence↗

Three single-strand origins located on both strands of the Streptomyces rolling circle plasmid pSN22.

pSN22 is an 11-kbp, high-copy-number Streptomyces plasmid which replicates via a single-stranded intermediate by the rolling circle replication (RCR) mechanism. We identified an unidirectional single-strand origin (SSO) of pSN22, sso1, where the initiation of second-strand synthesis takes place, located between the spdA and traR genes in a noncoding region which is functional in its natural orientation. The nucleotide sequence of sso1 is similar over 170 bp to the SSOs of the Streptomyces plasmids pIJ101 and pJV1. A previous report described that a 548-bp BglII-SmaI fragment has an SSO activity (ori2; Kataoka et al., Mol. Gen. Genet. 242, 130-136, 1994). To our surprise, we discovered that on pSN22, the SSO in the BglII-SmaI fragment is in the wrong, inactive, orientation and thus cannot be involved in the conversion of the single-stranded pSN22 replication intermediate to the double-stranded form of the plasmid. We revealed that this BglII-SmaI fragment contains two SSO fragments. Secondary structure analysis of these two SSOs showed similarity to the consensus TAGCGT which is conserved in SSOs of RCR plasmids from Staphylococcus and the other several Gram-positive bacteria. Deletion of these hexanucleotide sequences caused loss of SSO activities. Our result shows that two types of SSOs, Streptomyces type and Staphylococcus-like type, can function in Streptomyces lividans.

Base Sequence↗

A localized fibrous tumor (mesothelioma) in the mediastinum: report of a case.

We report herein the rare case of a 51-year-old Japanese woman who underwent thoracotomy for a mass in the mediastinum which was found to be a benign localized fibrous tumor, otherwise known as a mesothelioma. The clinical behavior of this tumor is thought to be unpredictable, and therefore we emphasize that long-term follow-up of patients with localized fibrous tumors is necessary, even if the histological features are benign.

Female↗

Markedly induced asialoGM1+CD8+ T cell production and enhancement of antimetastatic activity by interferon beta with folic or folinic acid.

Either folic or folinic acid enhanced the antimetastatic activity of recombinant murine interferon beta (rMulFN beta) toward highly metastatic colon carcinoma 26 (Co 26Lu). Folinic acid administered with rMuIFN beta markedly increased asialoGM1+CD4+ and asialoGM1+CD8+ T cell production in the peritoneal cavity but not in the thymus and spleen. Peritoneal cells expressed killing activity toward Co 26Lu cells in vitro. In athymic nude mice, the above combination produced many asialoGM1+CD4+ and few asialoGM1+CD8+ T cells in the peritoneal cavity, but did not decrease lung metastatic colonies. AsialoGM1+CD4+ T cells would thus appear to have no or only very weak killing activity toward these tumor cells. The antimetastatic activity of folinic acid with rMuIFN beta was significantly decreased with anti-asialoGM1 and anti-CD8 antibodies. Inactivated CD8+ and asialoGM1+ cells cease to have killing activity toward Co 26Lu cells as shown by Winn's assay. AsialoGM1+CD8+ cell production was markedly induced in the peritoneal cavity by treatment with rMuIFN beta and folinic acid. AsialoGM1+CD8+ T cells may be inhibiting lung metastasis of Co 26Lu. Folinic acid and interferon are used in combination therapy with 5-fluorouracil for biochemical modulation. Folinic acid with interferon, as adjuvant therapy, may promote the induction of CD8+ T cell production with consequent prevention of metastasis.

Animals↗

Agouti signaling protein inhibits melanogenesis and the response of human melanocytes to alpha-melanotropin.

In mouse follicular melanocytes, the switch between eumelanin and pheomelanin synthesis is regulated by the extension locus, which encodes the melanocortin-1 receptor (MC1R) and the agouti locus, which encodes a novel paracrine-signaling molecule that inhibits binding of melanocortins to the MC1R. Human melanocytes express the MC1R and respond to melanotropins with increased proliferation and eumelanogenesis, but a potential role for the human homolog of agouti-signaling protein, ASIP, in human pigmentation has not been investigated. Here we report that ASIP blocked the binding of alpha-melanocyte-stimulating hormone (alpha-MSH) to the MC1R and inhibited the effects of alpha-MSH on human melanocytes. Treatment of human melanocytes with 1 nM-10 nM recombinant mouse or human ASIP blocked the stimulatory effects of alpha-MSH on cAMP accumulation, tyrosinase activity, and cell proliferation. In the absence of exogenous alpha-MSH, ASIP inhibited basal levels of tyrosinase activity and cell proliferation and reduced the level of immunoreactive tyrosinase-related protein-1 (TRP-1) without significantly altering the level of immunoreactive tyrosinase. In addition, ASIP blocked the stimulatory effects of forskolin or dibutyryl cAMP, agents that act downstream from the MC1R, on tyrosinase activity and cell proliferation. These results demonstrate that the functional relationship between the agouti and MC1R gene products is similar in mice and humans and suggest a potential physiologic role for ASIP in regulation of human pigmentation.

Agouti Signaling Protein↗

Cell Hydrophobicity and Sulfur Adhesion of Thiobacillus thiooxidans.

Thiobacillus thiooxidans cells became more hydrophobic but less adhesive to elemental sulfur in the presence of increasing potassium phosphate concentrations. At a fixed concentration of potassium phosphate, however, there was a peak of both cell hydrophobicity and adhesion to sulfur at around pH 5. Oxidation of sulfur by the cells was affected in a complex manner by the phosphate concentration and pH, although it was inhibited by a high concentration of potassium phosphate.

Journal Article↗

Identification and nitrogen regulation of the cyanase gene from the cyanobacteria Synechocystis sp. strain PCC 6803 and Synechococcus sp. strain PCC 7942.

An open reading frame (slr0899) on the genome of Synechocystis sp. strain PCC 6803 encodes a polypeptide of 149 amino acid residues, the sequence of which is 40% identical to that of cyanase from Escherichia coli. Introduction into a cyanase-deficient E. coli strain of a plasmid-borne slr0899 resulted in expression of low but significant activity of cyanase. Targeted interruption of a homolog of slr0899 from Synechococcus sp. strain PCC 7942, encoding a protein 77% identical to that encoded by slr0899, resulted in loss of cellular cyanase activity. These results indicated that slr0899 and its homolog in the strain PCC 7942 represent the cyanobacterial cyanase gene (designated cynS). While cynS of strain PCC 6803 is tightly clustered with the four putative molybdenum cofactor biosynthesis genes located downstream, cynS of strain PCC 7942 was found to be tightly clustered with the two genes located upstream, which encode proteins similar to the subunits of the cyanobacterial nitrate-nitrite transporter. In both strains, cynS was transcribed as a part of a large transcription unit and the transcription was negatively regulated by ammonium. Cyanase activity was low in ammonium-grown cells and was induced 7- to 13-fold by inhibition of ammonium fixation or by transfer of the cells to ammonium-free media. These findings indicated that cyanase is an ammonium-repressible enzyme in cyanobacteria, the expression of which is regulated at the level of transcription. Similar to other ammonium-repressible genes in cyanobacteria, expression of cynS required NtcA, a global nitrogen regulator of cyanobacteria.

Amino Acid Sequence↗