Biomedical subjects

Takeshi Usami

Publications and source records attributed to Takeshi Usami.

26 records · Page 2Linked to original sources

PubMed2003

Cardiac failure caused by severe pre-eclampsia with placental abruption, and its treatment with anti-hypertensive drugs.

Pre-eclampsia is the abnormality of blood circulation in late pregnancy, often caused by renal failure, hemolysis, elevated liver enzyme, low platelet syndrome, and eclampsia. We present a case of severe pre-eclampsia with placental abruption in a 24-year-old woman, pregnant for the first time. The patient was diagnosed with congestive heart failure, which came as a result of pre-eclampsia. Anti-hypertensive drugs were used for its treatment.

Abruptio Placentae↗

PubMed2003

Maps of end-stage renal disease and amounts of angiotensin-converting enzyme inhibitors prescribed in Japan.

BACKGROUND: We recently found regional differences in the incidence of end-stage renal disease (ESRD) in Japan, which is generally ethnically homogeneous, suggesting that factors other than genetic may contribute to the difference. Here, we examined regional differences in the amounts of expenses spent on antihypertensives, especially angiotensin-converting enzyme (ACE) inhibitors, in our search for an explanation. METHODS: Annually, the Japanese Society for Dialysis Therapy reports the numbers of patients entering maintenance dialysis in each prefecture of Japan since 1982. We used the findings for 1995 to 2000 to calculate the annual incidence of ESRD in each of the 11 regions of Japan. In addition, regional differences in annual amounts paid for antihypertensive drugs, presumably corresponding to the amounts used, during the same 6 years, corrected for population, were estimated. RESULTS: As in our 1982 to 1998 study, the incidence of ESRD was high in Okinawa, Kyushu, and Shikoku, while low in Hokuriku, Koshinetsu, and Tohoku (P < 0.0001) [one-way repeated measures analysis of variance (ANOVA)]. We found regional differences in the corrected sum paid for total antihypertensive drugs, ACE inhibitors and calcium antagonists. Only ACE inhibitors were negatively correlated with the incidence of ESRD by linear and multiple regression analyses. CONCLUSION: The renal protective effects of ACE inhibitors have been established by results with animal models of progressive nephropathy and large-scale clinical trials. Our epidemiologic results for Japan as a whole show the same protective effects still more convincingly from a different approach.

Angiotensin-Converting Enzyme Inhibitors↗

PubMed2003

Construction of a cDNA microarray derived from the ascidian Ciona intestinalis.

A cDNA microarray was constructed from a basal chordate, the ascidian Ciona intestinalis. The draft genome of Ciona has been read and inferred to contain approximately 16,000 protein-coding genes, and cDNAs for transcripts of 13,464 genes have been characterized and compiled as the "Ciona intestinalis Gene Collection Release I". In the present study, we constructed a cDNA microarray of these 13,464 Ciona genes. A preliminary experiment with Cy3- and Cy5-labeled probes showed extensive differential gene expression between fertilized eggs and larvae. In addition, there was a good correlation between results obtained by the present microarray analysis and those from previous EST analyses. This first microarray of a large collection of Ciona intestinalis cDNA clones should facilitate the analysis of global gene expression and gene networks during the embryogenesis of basal chordates.

Animals↗

PubMed2002

Nd:YAG-pumped periodically poled LiNbO3 optical parametric generator seeded with the narrowband output of a 532-nm pumped optical parametric generator.

We present a simple scheme to generate a continuously tunable pulsed narrow-bandwidth infrared wave. An Nd:YAG-pumped periodically poled lithium niobate optical parametric generator (OPG) is seeded with the output of another OPG pumped by the second harmonic (0.532 microm) of the Nd:YAG laser. A tunable idler wave from the 0.532-microm pumped OPG, operated away from the degenerate point, provides a narrow linewidth seed source for the 1.064-microm pumped broadband OPG. Seeding forces the second OPG to operate in a narrowband operation comparable with that of the seed source. Linewidth of the YAG-pumped OPG is 5-25 nm, in the tuning range of 1.61-1.83 microm (signal), narrowed to 1.48-1.05 nm. Methods of further reduction of linewidth also have been discussed.

Journal Article↗

PubMed2002

Evaluating mental fatigue in patients with obstructive sleep apnea syndrome by the Maastricht Questionnaire.

Mental fatigue in patients with obstructive sleep apnea syndrome (OSAS) was investigated and compared with subjects without OSAS. The study series comprised 189 habitual snoring patients and 75 controls. To measure subjective mental fatigue and somnolence, subjects were asked to complete the Maastricht Questionnaire (MQ) and the Epworth Sleepiness Scale (ESS), respectively, and patients also underwent diagnostic polysomnography. According to the apnea and hypopnea index, patients were classified into the following groups: primary snorers, or having mild, moderate, or severe OSAS. The lowest MQ and highest ESS scores were found in those patients with severe OSAS. It is proposed that the lowest MQ score is due to mental fatigue impairing awareness in patients with severe OSAS, probably because of attention loss.

Female↗

PubMed2002

Efficacy of methylcobalamin on lowering total homocysteine plasma concentrations in haemodialysis patients receiving high-dose folic acid supplementation.

BACKGROUND: Hyperhomocysteinaemia, which is considered to be induced by impairment of the remethylation pathway in patients with chronic renal failure (CRF), cannot be cured solely by folic acid therapy. In the present study, we investigated the additional benefit of administration of methylcobalamin, which is a co-enzyme in the remethylation pathway, on lowering total homocysteine (tHcy) plasma concentrations in haemodialysis (HD) patients receiving high-dose folic acid supplementation. METHODS: In order to assess the efficacy on lowering plasma tHcy levels (fasting concentration), 21 HD patients, were randomly assigned and provided folic acid supplementation: 15 mg/day orally (group I, n=7); methylcobalamin 500 mg intravenously after each HD, in addition to folic acid (group II, n=7); or vitamin B(6) (B(6)), 60 mg/day orally, in addition to folic acid and methylcobalamin (group III, n=7). All patients were treated for 3 weeks. A methionine-loading test was conducted before and after supplementation. The following measurements were also made before and after supplementation for each group: serum folic acid, B(6), and vitamin B(12) (B(12)) concentrations (including measurement of proportion of methylcobalamin fraction). Twelve HD patients receiving methylcobalamin alone served as the HD control group and seven healthy volunteers served as the normal control group for this study. RESULTS: In our randomized HD patients the proportions of methylcobalamin fraction (48.3+/-7.5%) and plasma vitamin B(6) concentration (2.9+/-1.1 ng/ml) were significantly lower than in the normal controls (methylcobalamin 58.7+/-2.2%, P<0.01; B(6) 20.1+/-10.8 ng/ml, P<0.01), while folic acid and vitamin B(12) were not significantly different from the normal controls. Mean percentage reduction in fasting tHcy was 17.3+/-8.4% in group I, 57.4+/-13.3% in group II, 59.9+/-5.6% in group III, and 18.7+/-7.5% in HD controls. The power of the test to detect a reduction of tHcy level was 99.6% in group II and 99.9% in group III when type I error level was set at 0.05. Groups II and III had normal results for the methionine-loading test after treatment. Treatment resulted in normalization of fasting tHcy levels (<12 ng/ml) in all 14 patients treated by the combined administration of methylcobalamin and supplementation of folic acid regardless of whether there was supplementation of vitamin B(6). CONCLUSION: The benefit of methylcobalamin administration on lowering plasma tHcy levels in HD patients was remarkable. Our study suggested that both supplementations of high-dose folic acid and methylcobalamin are required for the remethylation pathway to regain its normal activity. This method could be a therapeutic strategy to combat the risk associated with atherosclerosis and cardiovascular disease in patients with chronic renal failure.

Adult↗

PubMed2002

Regional variation in end-stage renal disease.

Regional variations in end-stage renal disease have been found within a country, even within a race. Since diabetic nephropathy is the leading cause of end-stage renal disease in developed countries, first of all, regional differences in diabetic nephropathy must be considered. Although the incidence of end-stage renal disease due to diabetic nephropathy has been found to differ among different areas within a country, there are no data on regional variations in the incidence of type II diabetes or diabetic nephropathy without renal failure. Such regional variations could hardly be explained by local differences in gene pools alone, which suggests an important role of environmental factors. It is not clear at present how regional variations in the incidence of end-stage renal disease are generated. If we can identify the factors that contribute to the regional differences, we can take these into account in future treatment strategies for renal disease. Thus, much effort is required in further analysis of regional differences in end-stage renal disease dynamics.

Diabetic Nephropathies↗

PubMedDate not supplied

A cDNA microarray technique applied for analysis of global gene expression profiles in tributyltin-exposed ascidians.

To analyze global gene expressions, we constructed a cDNA microarray from a basal chordate, the ascidian Ciona intestinalis. Ciona is a cosmopolitan species and a genomic analysis of Ciona revealed that ascidians had approximately 15,500 protein-coding genes. Our "Ciona intestinalis cDNA chip version 1 (Ci cDNA chip ver. 1)" has arrayed 13,400 unique Ciona cDNAs. To establish a detection system for gene expression profiles in wild ascidians using a cDNA microarray, we analyzed gene expressions in the whole body of Ciona adults after exposure to 100 nM tributyltin (TBT) for 24 h. In our preliminary array data using Ci cDNA chip ver. 1, we found more than 200 genes that showed strong differential expressions. These genes encoded proteins that were concerned with stress response, detoxification, oxidoreduction reaction, biosynthesis, and catabolism. This, the first large cDNA microarray of this animal, should facilitate analyses of global gene expressions following exposure to TBT.

Animals↗