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Biomedical subjects

M Wada

Publications and source records attributed to M Wada.

At least 145 records · Page 8Linked to original sources

A novel specific bioassay for serum human growth hormone.

Human GH receptor (hGHR) was recently expressed on a Ba/F3 cell line, which is a mouse pro-B cell lymphoma that has been induced to become a cloned cell line (Ba/F3-hGHR). Using a Ba/F3-hGHR cell line, we have established a bioassay for serum hGH. hGH stimulated cell proliferation in a dose-dependent manner in concentrations ranging from 1 ng to 100 ng/mL. Cell proliferation was not influenced by other hormones or growth factors in the bioassay, with the exception of insulin-like growth factor I (IGF-I) and GH binding protein. Free IGF-I significantly stimulated the proliferation of Ba/F3-hGHR cells at concentrations over 25.85 ng/mL in this bioassay system, but serum IGF-I did not stimulate cell proliferation because the sensitivity of cell proliferation was insufficient for free IGF-I in serum. GH binding protein, however, did suppress cell proliferation at the highest concentration (100 ng/mL), but did not at the average concentration (20 ng/mL). Human serum stimulated cell proliferation, which was completely suppressed by anti-GH antibody. The GH bioactivity of serum samples from normal children and patients with non-GH deficient short stature correlated strongly with the serum hGH concentration determined by immunoradiometric assay (IRMA) (r = 0.967, r = 0.924, P < 0.0001, respectively). The ratio of bioactivity/IRMA was 1.01+/-0.26 in sera from normal children and 1.18+/-0.24 and 1.00+/-0.29 at basal values and peak values in GH stimulation tests, respectively, in sera from patients with non-GH deficient short stature. The bioactivity/IRMA ratio for the serum GH bioactivity of a patient who had biologically inactive GH caused by an amino acid substitution was 0.333+/-0.056 (mean +/- SD). In conclusion, we established a new sensitive bioassay for hGH that is specific for hGH somatogenic action and is useful for screening of patients with short stature caused by biologically inactive hGH.

Antibodies↗

Effect of iron(III) chitosan intake on the reduction of serum phosphorus in rats.

Because of the widespread use of aluminium- and calcium-containing phosphate binders for the control of hyperphosphataemia in patients with end-stage renal failure, an iron(III) chitosan complex was synthesised and fed to rats to measure its effect on serum phosphorus and calcium, intestinal phosphate binding and phosphate absorption. Thirty-six Wistar rats were randomly selected and distributed into a baseline group (n = 6), a control group (n = 8 (days 0-15), n = 8 (days 16-30)) and a treatment group (n = 8 (days 0-15), n = 8 (days 16-30)). The control groups ingested AIN-76 diet mix with a 1% w/w fibre content; however, the treatment groups had the fibre content completely substituted with iron(III) chitosan. The mean weights of the treated rats were slightly lower from 15 days (not significant); but overall, rat growth was not stunted in the treatment groups. The serum phosphorus levels of the treated group (n = 8) were significantly reduced after 15 days (P = 0.004; control: 5.7+/-0.9 mg dL(-1); treatment: 4.4+/-0.5 mg dL(-1); 95% CI of difference: 0.5-2.2) and 30 days (P = 0.002; control: 5.5+/-0.9 mg dL(-1); treatment = 4.1+/-06 mg dL(-1); 95% CI of difference: 0.6-2.3) as compared with the respective control group. The serum calcium-phosphorus product was 62.0+/-12.1 mg2 dL(-2) for the control and 45.1+/-6.6 mg2 dL(-2) for the treatment group after 30 days (P = 0.004). The serum iron concentration of the treatment group did not differ from the baseline value after 15 and 30 days, but the treatment group was significantly higher than the control group (P<0.05) after 30 days. The faeces phosphorus levels (mg day(-1)) were higher (P<0.01) and its iron content was much higher (P<0.01) for the treated group. The urine phosphorus (mg kg(-1)) was not significantly reduced for the treated group, but the mean was consistently less. The kidney and liver weights of both groups were similar, but the phosphorus content of the kidney (mg (g kidney)(-1)) was higher for the treated group after 30 days (P = 0.041; control, 4.2+/-1.2 mg g(-1) vs treatment, 5.6+/-1.4 mg g(-1). Because iron(III) chitosan had a high phosphorus-binding capacity of 308 (mg P) per gram of Fe3+ for both the in-vitro (pH 7.5) and in-vivo studies, which is greater than nearly all commonly used phosphate binders, and a small net phosphorus absorption difference of 3.7 mg day(-1), it is an efficient phosphate binder for lowering serum phosphate levels without increasing serum calcium levels.

Animals↗

Super-high-definition image systems for telemedicine.

Super-high-definition (SHD) images are those with more than 2048 pixels x 2048 lines. They are of interest in the medical field because of their very high quality. We have developed a new SHD system for still pictures which is based on an SHD card that can be installed in a PC. We think that certain telemedicine applications will be facilitated by the use of SHD images.

Diagnostic Imaging↗

Molecular cloning and overexpression of the gene encoding an NADPH-dependent carbonyl reductase from Candida magnoliae, involved in stereoselective reduction of ethyl 4-chloro-3-oxobutanoate.

An NADPH-dependent carbonyl reductase (S1) isolated from Candida magnoliae catalyzed the reduction of ethyl 4-chloro-3-oxobutanoate (COBE) to ethyl (S)-4-chloro-3-hydroxybutanoate (CHBE), with a 100% enantiomeric excess, which is a useful chiral building block for the synthesis of pharmaceuticals. The gene encoding the enzyme was cloned and sequenced. The S1 gene comprises 849 bp and encodes a polypeptide of 30,420 Da. The deduced amino acid sequence showed a high degree of similarity to those of the other members of the short-chain alcohol dehydrogenase superfamily. The S1 gene was overexpressed in Escherichia coli under the control of the lac promoter. The enzyme expressed in E. coli was purified to homogeneity and had the same catalytic properties as the enzyme from C. magnoliae did. An E. coli transformant reduced COBE to 125 g/l of (S)-CHBE, with an optical purity of 100% enantiomeric excess, in an organic solvent two-phase system.

Acetoacetates↗

Triterpene phytoalexins from strawberry fruit.

Strawberry cv. Houkouwase is resistant to infection by Colletotrichum fragariae. The formation of antifungal compounds was observed in unripe fruit which had been wounded and inoculated with conidia of C. musae. Three antifungal compounds were isolated and identified as euscaphic acid, tormentic acid and myrianthic acid. Myrianthic acid inhibited the growth of C. musae at 3 microg, and euscaphic and tormentic acids showed inhibitory effects at 100 microg. A quantitative analysis of their contents showed that the triterpenes increased in wounded fruit, and in wounded and inoculated fruit, but not in non-treated fruit. These findings indicate that unripe fruit of Houkouwase produced the triterpenes as phytoalexins. The triterpene phytoalexins seem to be involved in the resistance of strawberry to the fungus.

Anti-Infective Agents↗

Effect of cobalamin on the allergic response in mice.

Cyanocobalamin, deoxyadenosylcobalamin and methylcobalamin were separately administered to mice sensitized with the ovalbumin antigen to investigate the allergic response. The serum IgE and pulmonary histamine concentrations were significantly lower in all cobalamin (Cbl)-administered groups. The production of interleukin (IL)-2 and IL-4 in splenocytes was also lower in all Cbl-administered groups. These results show that Cbls were effective in mitigating allergic reactions and IL-2 production. CD3+ CD28+ (CD28 is an accessory molecule related to IL-2 production) and CD4+ CD28+ in splenocytes were higher in all the Cbl-administered groups. However, CD3+ CD28-, CD4+ CD28- and CD5+ CD25- (CD25: IL-2 R alpha/p55) were lower in the Cbl-administered groups. In addition, Cbl specifically inhibited the cellular phosphorylation of tyrosine induced by ovalbumin sensitization. These results indicate that the signal in a cell by CD 28 was restrained by Cbl. We infer that Cbl administration significantly reduced the IL-2 concentration, and secondarily the IL-4, IgE and histamine concentrations.

Animals↗

Successful removal of a stone and an expandable metallic stent from the biliary tract of a patient with acute occlusive pyogenic cholangitis.

We removed a biliary stone and the metallic stent placed two years previously in a patient with benign biliary strictures. An 80-year-old woman who had been inplanted with an expandable metallic stent (EMS) to prevent obstruction by a large common bile duct stone about two years before as an emergency measure in another hospital, was afficted with acute occlusive pyogenic cholangitis (AOPC) and hospitalized in our hospital. After treating the AOPC, we successfully removed the EMS with a cholangioscope and normal biopsy forceps through the percutaneous transhepatic channel under fluoroscopy. The type of the EMS was Accufulex stent. To remove it was easier than expected. Once it started to unravel, it was removed from the common bile duct within a few minutes.

Acute Disease↗

Depressive mood and suicide among middle-aged workers: findings from a prospective cohort study in Nagoya, Japan.

BACKGROUND: In Japan, mortality from suicide has peaked around 50 years old among men, with increasing trend after 65 years old, and this peak became more apparent in recent years. Beside this, "psychological autopsy" has revealed depression as one of the most important risk factors for suicide. There is, however, no cohort study which examined the relationship between depressive mood measured by simple method and suicide in middle-aged general population. METHODS: In 1989, baseline information was collected by a self-administered questionnaire, and 18,450 workers were followed up to March 31, 1995. All deaths observed during active service were identified, and when retired, its date was recorded. Among 5,352 male workers aged between 40 to 54, 11 committed suicide during follow-up period of 5 years. Analysis were carried out by Cox's proportional hazard model, controlling for age. RESULTS: Those who slept 9 hours or more per night demonstrated 12.14-fold risk of suicide compared with those who slept less than 9 hours. Smokers were more likely to commit suicide than non-smokers. Those who answered affirmatively to more than 7 out of 12 questions, which were derived from Zung self-rating depression scale, experienced an increased risk of suicide (RR 9.95; 95%CI: 1.89-52.44), even after adjusting for other confounding factors. CONCLUSION: We found an association between depressive mood and subsequent suicide in a middle-aged workers. Detailed observation and follow-up of those with depressive mood should be systematically organized with due attention and caution.

Adult↗

Factors influencing the visual acuity of primary school pupils.

To investigate the factors influencing the visual acuity of primary school pupils, an epidemiological study of 480 pupils in the 6th grade (11-12 years of age) was conducted in 8 primary schools in Sapporo City, Japan. Questionnaires were used to inquire into their current and past visual acuity and related factors. Dividing the subjects into those whose visual acuity of both eyes was 0.7 or more and those whose visual acuity of at least one eye was less than 0.7, odds ratios of various factors were calculated. Lifestyle and dietary factors showed no significant odds ratios. Parental myopia and age of parents at the birth of subjects showed significant odds ratios. Visual acuity of the pupils whose parents were myopic or older than 30 years when they were born tended to have worse visual acuity as they got older. Till the ages 11 or 12, hereditary factors seem much more contributory to visual acuity than environmental ones.

Chi-Square Distribution↗

Delineation of the frequently deleted region on chromosome arm 13q in B-cell non-Hodgkin's lymphoma.

The loss of a specific chromosomal region provides a clue to the elucidation of the putative tumor suppressor gene implicated in the pathogenesis and progression of tumors. To delineate the specific region(s) involved in lymphomagenesis, we performed a survey of loss of heterozygosity for 11 polymorphic microsatellite loci scattered on variable chromosome arms. We examined 20 primary lymphoma samples, including both indolent and aggressive B-cell non-Hodgkin's lymphoma (B-NHL) and Hodgkin's disease (HD), and found a significant number of B-NHLs with loss of genetic material on chromosome arm 13q at the RB1 locus (50%; 4 of 8 informative cases for the RB1 locus). To specify the 13q deletion and to narrow the critical deleted region, we examined the same 20 lymphomas by intensive microsatellite mapping analysis using 12 microsatellite markers, mapping from 13q12.3 to 13q14. We confirmed the frequent 13q14 deletion to be in the vicinity of the RB1 locus (50% of the informative NHLs for at least 1 of 12 microsatellite loci; 5 of 10 aggressive NHLs and 2 of 4 indolent NHLs, but none of 6 HDs) and determined a subchromosomal region deleted in lymphoma on 13q14 defined by D13S164-D13S273, which is an overlapped region frequently lost in chronic lymphocytic leukemia. Taken together, our data indicate that the 13q alterations are present in a wide variety of NHLs including both indolent and aggressive B-NHLs, suggesting that loss of genetic material at chromosome band 13q14 may play an important role in the formation or development of a wide variety of mature lymphoid malignancies.

Adult↗

Effective resolution of chiral 1,1':5',1"-ternaphthalene-2,2',6',2"-tetrol through camphorsulfonylation, recrystallization and reductive desulfonylation

Optical resolution of the title compound, TERNOL (1), having bis-bidentate sites of axial chiralities was succesful. A racemic mixture of 1 was converted to the tetracamphorsulfonate 2 in high yield, and a single recrystallization of 2 under kinetic conditions effectively separated the diastereomers. The crystal part obtained in 44% yield consisted of (S,S)-2 of 96% diastereomer excess (de), and the solution part (50% yield) contained (R,R)-2 of 96% de. An additional recrystallization of the each part resulted in diastereomerically pure 2 in high yield. Hydride reduction of the ketones in the camphorsulfonyl groups of 2 caused smooth intramolecular transesterification, and enantiomerically pure (R,R)-1 and (S,S)-1 were obtained in good yields.

Journal Article↗

[Treatment of peripheral aneurysms of the posterior circulation].

Peripherally located aneurysms of the posterior circulation are extremely rare. The outcome of patients with peripherally located aneurysms has been poor, and the treatment of such aneurysms has been surgically challenging. We report a consecutive series of peripherally located ruptured aneurysms in the posterior circulation, and discuss in this article the optimal treatment strategy for such lesions. Clinical presentation, neuroradiological findings, treatment method, and the outcome were reviewed retrospectively. Two cases with distal posterior cerebral artery aneurysm, two with distal posterior inferior cerebellar artery aneurysm, two with anterior inferior cerebellar aneurysm, and one with superior cerebellar artery aneurysm were included in this study (mean age, 59.3 +/- 16.0, M:F = 1:6). Three patients with good neurological status on admission who underwent clipping of the aneurysmal neck via craniotomy showed a favorable outcome. In contrast, four patients with poor neurological status on admission who underwent endovascular proximal occlusion of the parent artery showed an unfavorable outcome. Although the outcome of patients who underwent endovascular surgery was poor, endovascular proximal occlusion was effective in preventing re-rupture of the aneurysms. Proximal occlusion of the parent artery has several shortcomings such as cerebral infarction, but proximal occlusion at the very distal area of the parent arteries would not be critical because of good collateral circulation. Thus, endovascular proximal occlusion may provide us another option in the treatment of peripherally located aneurysms especially in patients with poor neurological status. Further data is needed to discover the optimal treatment for patients with peripherally located cerebral aneurysms.

Adult↗

Achiral and chiral quantification of methamphetamine and amphetamine in human urine by semi-micro column high-performance liquid chromatography and fluorescence detection.

In this paper, miniaturized achiral and chiral high-performance liquid chromatographic procedures for the determination of methamphetamine and amphetamine in human urine are described. After a simple pretreatment of human urine (i.e., 10 microL of urine or diluted urine were acidified and dried-up under N2 at room temperature) and fluorescence derivatization with 4-(4,5-diphenyl-1H-imidazol-2-yl)-benzoyl chloride under mild conditions (pH 9.0, 10 min at room temperature), the derivatives were isocratically separated on a semi-micro ODS column with Tris-HCl buffer (0.1 M, pH 7.0): acetonitrile (45 + 55 v/v) at a flow rate of 0.2 mL/min or their enantiomers were separated on a semi-micro OD-RH column with sodium hexafluorophosphate (0.3 M aq.): acetonitrile (44 + 56 v/v) at a flow rate of 0.1 mL/min as the mobile phase. Wide-ranged calibration curves were obtained with detection limits for the achiral and chiral analyses in the atto and femtomol levels, respectively, per injected volume. Satisfactory within- and between-day reproducibility data were obtained with both the methods with the highest relative standard deviation being 9.6%. The methods were applied to the determination of methamphetamine and amphetamine in human urine samples and the concentrations determined by the two methods were well correlated (r = 0.994).

Amphetamine↗

Reconstruction of a double nail deformity: a case report.

We report the successful reconstruction of a double nail deformity after fingertip injury. Double nail growth is rather rare. In our case it was not of congenital origin. Double nail deformity results from implantation of the nail matrix associated with damage to the finger tip. We excised the second nail and reconstructed the remaining nail bed using a part of the excised one. The vertical growth of the first nail was also corrected. Four months later, successful regeneration of the nail was observed.

Finger Injuries↗

Tranexamic acid: a "diuretic" for the peritoneal membrane?

The aim of the study was to use an animal model to investigate the mechanisms by which tranexamic acid (TNA) increases ultrafiltration (UF) volume. Thirty Sprague-Dawley rats were studied in three groups (n = 10, each group). Group 1 was dialyzed with conventional dialysis solution, group 2 with conventional fluid plus low-dose TNA (300 mg/L), and group 3 with conventional fluid plus high-dose TNA (3000 mg/L). A PD catheter was inserted into each animal, and 25 mL of the designated dialysis fluid was injected twice daily for two weeks, starting seven days after surgery. Peritoneal transport properties (PTP) were measured by modified peritoneal equilibration test (PET), and transcapillary ultrafiltration (TCUF) and lymphatic absorption (LA) were determined by using dextran 70 weekly. Histological examinations of the peritoneum were performed at the end of the experiment. Drained dialysate volume (DDV) decreased in all groups; however, a lower reduction in DDV was seen in the TNA groups. PTP increased and TCUF decreased in all groups. LA increased in Group 1, but was unchanged in the other groups. No significant histological changes of the peritoneum were observed in any group. This study confirmed that, in rats, TNA maintained UF volume by reducing LA without serious adverse effects. We may safely use TNA as a "diuretic" for the peritoneal membrane.

Absorption↗

[The effectiveness of pyrazinamide-containing six-month short course chemotherapy].

Incidence of tuberculosis worldwide will increase progressively unless the effective program is implemented immediately. In Japan, the decreasing of tuberculosis incidence has been very slow since 1977 and this trend has not been improved till now. Six-month regimens for the treatment of tuberculosis were recommended by IUATLD, ATS, CDC, and WHO and have been adopted in most developed countries since late 1980s, but not adopted in Japan till April, 1996. We studied effectiveness of 6-month regimen including pyrazinamide (2HRZS or E/4HRE) on newly diagnosed pulmonary tuberculosis who started the treatment in the Fukujuji Hospital, Japan Anti-Tuberculosis Association (JATA). From January 1991 to December 1997, 726 newly diagnosed pulmonary tuberculosis patients started treatment with 6-month regimen. Bacillary negative conversion rate among 424 patients whose bacilli were susceptible to both isoniazid and rifampicin, was 92.9% after 2 months of treatment and who completed treatment without change of treatment regimen. Among 726 cases, 593 (81.7%) succeeded, 48 (6.6%) defaulted, 53 (7.3%) were referred to other doctors, and 32 (4.4%) died. The relapse rate after completion of the treatment was 3.2 percent among 345 patients whose bacilli were susceptible to both isoniazid and rifampicin and who completed the treatment without change of regimen. The relapse rate among the patients complicated with diabetes mellitus (DM) was higher than that among non-DM patients (6.31/100 person-years vs 0.90/100 person-years) (P < 0.001). When drug-induced hepatitis was defined as the elevation of serum liver enzyme levels with the clinical symptoms of hepatitis or their elevation over 5 times of normal upper limit, the incidence of drug-induced hepatitis among the patients treated with pyrazinamide-containing 6-month regimen was not higher than that among the patients treated with 9-month regimen without pyrazinamide (6HRS or E/3HR) (7.9% vs 7.3%). The risk factors for drug-induced hepatitis included elderly, history of gastrectomy, hypoalbuminemia, the higher dose of isoniazid over than 7.5 mg/kg, higher than 30 mg/kg of pyrazinamide and positive HCV antibody. The effectiveness of 6-month regimen on the patients whose organisms were resistant to isoniazid and susceptible to rifampicin was studied. The average duration of the treatment for the patients started 6-month regimen was 3.2 months shorter than for the patients started 9-month regimen (10.2 months vs 13.4 months). I concluded that 6-month regimen containing-pyrazinamide was effective for the patients with isoniazid-rifampicin susceptible tuberculosis patients except the patients complicated with diabetes mellitus. But the frequency of drug-induced hepatitis was higher than that of previous reports, and further studies are needed to elucidate the cause of high frequency of hepatitis among Japanese patients.

Adult↗