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Biomedical subjects

S Naito

Publications and source records attributed to S Naito.

At least 55 records · Page 3Linked to original sources
PubMed2001

Resection of an L-shaped kidney with renal cell carcinoma using a microwave tissue coagulator.

An L-shaped kidney is a type of crossed fused renal ectopia and consists of two moieties which were originally two kidneys. It is an uncommon condition and cases of malignant tumors in such anomalies are exceedingly rare. A case of an L-shaped kidney with renal cell carcinoma is herein reported, in which a separation of both moieties was done in situ in order to perform a tumor resection. A literature review of this topic is also reported and the findings are discussed.

Carcinoma, Renal Cell↗
PubMed2001

Hand-assisted laparoscopic live donor nephrectomy using newly produced LAP DISC: initial three cases.

BACKGROUND: A new abdominal sealing device, called the LAP DISC, was used for the first time in hand-assisted laparoscopic live donor nephrectomy (HALDN) on three donors. The LAP DISC is made of three layers of rings connected by a rubber membrane, which covers the peritoneum and abdominal wall. The upper ring can adjust to the surgeon's hand size for insertion. METHODS: The LAP DISC was seated through an approximately 7-cm midline incision under the xiphoid process. The laparoscopic port was inserted through the LAP DISC, and thereafter, pneumoperitoneum was established. Three trocars were then placed under direct vision. The surgeon's left arm was inserted into the LAP DISC and used for manual retraction, dissection, and hemostasis. In the three operations, the kidneys were removed through the LAP DISC. RESULTS: The total warm ischemic times of the kidney were 15, 8, and 4 minutes, and the total operative times were 323, 195, and 240 minutes, respectively. After the subsequent transplantation into the recipient, the kidneys produced clear urine immediately on reperfusion. The recipient creatinine fell to 4.2, 5.6, and 3.9 mg/mL on postoperative day 1. All three donors resumed consistent oral intake within 24 hours after surgery and returned to normal, nonstrenuous activity by postoperative day 6. CONCLUSION: The LAP DISC device is excellent for HALDN and may increase the number of surgeons and donors who select HALDN.

Adult↗
PubMed2001

X-ray analyses of DNA dodecamers containing 2'-deoxy-5-formyluridine.

It is known that formylation of thymine base induces purine transition in DNA replication. In order to establish the structural basis for such mutagenesis, crystal structures of two kinds of DNA dodecamers d(CGCGRATf5UCGCG) with f5U = 2'-deoxy-5-formyluridine and R = A or G have been determined. The f5U residues form a Watson-Crick-type pair with A and two types of pairs (wobble and reversed wobble) with G, the latter being the first example. Structural modeling suggests that the DNA polymerase can accept the reversed wobble pair with G, as well as the Watson-Crick pair with A.

Base Pairing↗
PubMed2001

The first exon coding region of cystathionine gamma-synthase gene is necessary and sufficient for downregulation of its own mRNA accumulation in transgenic Arabidopsis thaliana.

Expression of the gene for cystathionine gamma-synthase (CGS), which catalyzes the key step of methionine biosynthesis, is feedback regulated at the level of mRNA stability. The first exon polypeptide of CGS is suggested to be involved in this regulation and amino acid sequence alterations caused by mto1 mutations in that region lead to an overaccumulation of CGS mRNA [Chiba et al. (1999) Science 286: 1371-1374]. Transgenic Arabidopsis thaliana harboring chimeric constructs in which wild-type or mto1 mutant CGS exon 1 are fused in-frame to reporter genes and driven by the cauliflower mosaic virus 35S RNA promoter were constructed. Studies with these transgenic lines demonstrated that the coding region of CGS exon 1 is necessary and sufficient for downregulation of its own mRNA accumulation in response to methionine application and that this region acts in cis in this process.

Arabidopsis↗
PubMed2001

Suppression of experimental membranous glomerulonephritis in rats by an anti-MHC class II antibody.

BACKGROUND: We previously reported that idiopathic membranous nephropathy (IMN) strongly correlated with HLA-DRB1*1501-DRB5*0101-DQAI*0102-DQB1* 0602, a specific haplotype of human major histocompatibility complex (MHC), in Japanese patients. To investigate the role of MHC in the development of rat Heymann nephritis (HN), an animal model of membranous nephropathy, a monoclonal antibody (mAb) specific to rat MHC class II antigen (RT1B) was administered, and its effectiveness in inhibiting HN was assessed. METHODS: Active HN was induced in HN-sensitive Lewis rats by administering brush border proteins of rat proximal uriniferous tubules (FX1A). Rats were divided into four groups: rats treated with 1,000 micorg anti-rat MHC class II mAb, rats treated with 100 microg anti-rat MHC class II mAb, rats treated with murine myeloma IgG, and rats that did not receive either FX1A or any other mAb. We examined the differences in 24-hour urinary protein excretion and serum alloantibody titers against FX1A between groups at different time intervals, and the histologic features of kidneys at the end of the study. RESULTS: HN was induced in Lewis rats by inoculation with FX1A antigen. Administration of anti-MHC class II mAb successfully lowered urinary proteins, production of anti-FX1A alloantibodies, and the development of glomerular lesions in a dose-dependent manner. CONCLUSION: The present results demonstrated that the MHC class II molecule itself is directly involved in the pathogenesis of HN, and suggest that this therapy would be any better (or less toxic) than nonselective immunosuppressants in the treatment of IMN.

Animals↗
PubMed2001

Fat-soluble vitamin status is not affected by diacylglycerol consumption.

OBJECTIVE: The objective of this study was to examine the effect of dietary diacylglycerol (DAG) on the bioavailability of fat-soluble vitamins in comparison with triacylglycerol (TAG). METHODS: We conducted a long-term administration test of DAG and TAG in 27 healthy men aged 27-47 years. After measuring baseline values, subjects were randomized into two groups, one group (n = 15) was given DAG and the other (n = 12) was given TAG. Subjects ingested 20 g of DAG or TAG either in mayonnaise or an emulsion drink of their own choice at meals once a day for 12 weeks. At 4, 8 and 12 weeks, fasting blood samples were drawn and serum levels of vitamin A, E, and D were measured. RESULTS: There were no significant changes in vitamin A levels throughout the study period. Compared to the initial values (using a Student's t test for paired values), significant differences of vitamin E and D were seen at some points during the experiment. According to a two-way repeated measures analysis of variance, however, DAG and TAG (lipid) and time had no effect on fat-soluble vitamin levels. CONCLUSIONS: Our results indicate that DAG does not affect the absorption of the fat-soluble vitamins in diets.

Adult↗
PubMed2001

Enantioselective uptake of BOF-4272, a xanthine oxidase inhibitor with a chiral sulfoxide, by isolated rat hepatocytes.

The transport mechanisms of the enantiomers of BOF-4272, a new drug for the treatment of hyperuricemia, were studied using freshly prepared rat hepatocytes. BOF-4272 consists of S(-) and R(+) enantiomers due to a chiral center in the sulfoxide moiety. The uptake of these BOF-4272 enantiomers by hepatocytes was found to be temperature and dose dependent. The temperature-dependent uptake of the S(-) and R(+) enantiomers showed saturation kinetics. The Km values for the S(-) and R(+) enantiomers were 59.3 and 25.7 microM, respectively, which was a significant difference (p < 0.05). However, the maximal uptake rate was comparable for both enantiomers. Metabolic inhibitors such as antimycin, oligomycin, rotenone, carbonylcyanide m-chlorophenyl hydrazone, and carbonyl cyanide-p-(trifluromethoxy)-phenylhydrazone significantly inhibited uptake of the R(+) enantiomer, but had little effect on uptake of the S(-) enantiomer. Ouabain (an inhibitor of Na+/K(+)-ATPase) and p-nitrobenzylthioinosine (NBMPR, a nucleoside transporter inhibitor) showed no significant effects on the uptake of either enantiomer. Organic anions such as taurocholate and cholate reduced the uptake of both enantiomers. These results suggest that the hepatic uptake of both BOF-4272 enantiomers is not due to simple diffusion but also involves carrier-mediated uptake. We suggest that the carrier-mediated uptake of BOF-4272 enantiomers includes both NBMPR-insensitive facilitated diffusion and an active transport system in liver plasma membrane, and that the enantioselective uptake of BOF-4272 is due to differences in affinity for the active transporter.

Animals↗
PubMed2001

Electrocardiographic ST-segment elevation and changes in the regional work of the left ventricle during coronary angioplasty.

This study evaluated the reduction in regional work of the left ventricle caused by acute myocardial ischemia during coronary angioplasty, and correlated it with ST-segment elevation. Regional work of the left ventricular myocardium, which is derived from a stress-strain loop, is a useful index of the function of a diseased heart. However, the effects of transient ischemia on the regional work of the myocardium have not been fully elucidated. The subjects consisted of 25 patients who had proximal left anterior descending artery stenosis with normal wall motion and without collateral circulation. The patients were classified as showing ST-segment elevation > or = 0.2 mV (group A, 10 patients), or ST-segment elevation < 0.2mV (group B, 15 patients) during coronary angioplasty. Group A showed a greater reduction in the regional work of the interventricular septum than group B. Regional work recovered to the baseline level 30 s after balloon deflation in group B, but took 40 s in group A. A greater ST elevation during balloon inflation was associated with a greater, prolonged reduction of work performance in the ischemic region and a greater concomitant increase in the opposite nonischemic region.

Acute Disease↗
PubMed2001

Short-term physical training improves ventilatory response to exercise after coronary arterial bypass surgery.

The issue of whether exercise training improves exercise hyperpnea in patients after coronary arterial bypass graft (CABG) surgery has not been fully explored. Effects of short-term physical training on ventilatory response and cardiac output during exercise in patients following coronary arterial bypass grafting surgery is studied. Thirty-four patients underwent exercise training for 2 weeks after the second postoperative week (Ex group); 23 stayed sedentary (Sed group). Ventilatory and cardiac output response during the cardiopulmonary exercise test was measured before and after the training period. The minute ventilation-carbon dioxide output (VE-VCO2) slope decreased from 38.9+/-8.1 to 35.1+/-6.7 (p<0.05) in the Ex group, but failed to decrease in the Sed group (39.7+/-11.1 to 41.5+/-11.4). Cardiac output during exercise at 20W and at peak exercise, and peak oxygen pulse (VO2/HR) increased significantly only in the Ex group after training. There was a correlation between improvement of the VE-VCO2 slope and peak cardiac output during the training interval (r=-0.47) in the Ex group. Short-term physical training after CABG improves ventilatory response to exercise and increases cardiac output during exercise. Improvement of cardiac output is correlated with a decreased value of the VE-VCO2 slope.

Aged↗
PubMed2001

Left ventricular epicardial outflow tract tachycardia: a new distinct subgroup of outflow tract tachycardia.

The present study investigated the incidence and ECG characteristics of ventricular tachycardias (VTs) originating from the left ventricular (LV) epicardium. Thirty-one consecutive patients with VT or premature ventricular contraction originating from the outflow tract (OT-VT) underwent catheter ablation. Twenty-one OT-VTs were ablated from the endocardium in the right ventricular (RV) OT and 3 were ablated from the endocardium in the LVOT. In the remaining 7 patients, 4 (13%) OT-VTs were LV epicardial in origin, and 1 of these was ablated from the left sinus of Valsalva. The ECG characteristics of OT-VT of epicardial origin included prominent tall R-waves in the inferior leads, an R-wave in V1 and an S-wave in V2, precordial R-wave transition in V2-4, a deep QS-wave in aVL, and no S-wave in V6. In addition, there was an atypical left bundle branch block morphology with an inferior axis. These findings were observed during pacing from several sites in the LV epicardium. Furthermore, pacing from the left sinus of Valsalva caused a relatively tall R in V1, deep S-wave in V2 and a tall R-wave with a shallow S-wave in V3, as well as tall R-waves in the inferior leads, which represented intermediate characteristics between RV endocardial OT-VT and LV endocardial OT-VT. In conclusion, OT-VT originating from the LV epicardium is not uncommon and has characteristic ECG findings. Some of them can be ablated from the left sinus of Valsalva.

Adult↗
PubMed2001

[Outcome of patients with significant coronary stenosis but without ischemic evidence on exercise myocardial perfusion scintigraphy].

OBJECTIVES: The rates of cardiac events and coronary revascularization were evaluated in patients with significant coronary stenosis of more than 75% by the American Heart Association (AHA) classification but no ischemic evidence by exercise myocardial perfusion scintigraphy. METHODS: Subjects were 171 patients (113 males, 58 females, mean age 66 +/- 9 years) undergoing coronary angiography and without scintigraphic evidence of myocardial ischemia. They were divided into two groups according to the severity of coronary artery stenosis based on AHA classification. Group A was composed of 139 patients with more than 75% stenosis (101 patients with 75% stenosis and 38 patients with more than 90% stenosis), and Group B was composed of 32 patients with 50% stenosis. Cardiac events including angina pectoris (n = 63), myocardial infarction (n = 1), heart failure (n = 2) and cardiac death (n = 0), coronary revascularization and predictive factors were evaluated during follow-up of 34 +/- 21 months. Furthermore, the interval between coronary revascularization and exercise myocardial perfusion scintigraphy was estimated. RESULTS: The rates of cardiac events (45%) and coronary revascularization (29%) in Group A were significantly higher than the rate of cardiac events (9%, p < 0.05) and coronary revascularization (6%, p < 0.05) in Group B. Only percentage stenosis and the number of diseased vessels affected the rates of cardiac event and coronary revascularization. CONCLUSIONS: Patients with significant coronary stenosis, but without ischemic evidence by exercise myocardial perfusion scintigraphy, have a relatively high rate of cardiac event and coronary revascularization, especially in patients with severe stenosis or multivessel disease. However, coronary revascularization should not be performed in all patients with significant coronary stenosis.

Aged↗
PubMed2001

[Clinical effects of a 3-month formulation LH-RH agonist (Zoladex LA 10.8 mg depot) in patients with prostate cancer].

Pharmacodynamics (PD), anti-tumor effects, safety and pharmacokinetics of a 3-month formulation of goserelin (Zoladex LA 10.8 mg depot: "10.8 mg depot") were investigated in a collaborative multicenter study. Study participants were 40 Japanese patients with prostate cancer comprising 20 untreated patients and 20 switch patients who had been receiving Zoladex 3.6 mg depot for 3 months or longer. Serum testosterone levels, serum LH levels, prostate-specific antigen (PSA) levels and drug concentrations were measured until 12 weeks after a single subcutaneous dose of 10.8 mg depot. Anti-tumor effects were evaluated by means of changes in the tumor lesions and the PSA levels at 12 weeks. After administration to the untreated patients, 10.8 mg depot reduced serum testosterone to the castrate range within 4 weeks and the reduction was maintained for up to 12 weeks. In the switch patients, serum testosterone suppression that had been produced by previous treatment with Zoladex 3.6 mg depot was maintained for up to 12 weeks following 10.8 mg depot administration. The anti-tumor effect at 12 weeks was 90.0% including partial response cases. The ratio of PSA normalization at 12 weeks was 75.0%. Fifty-seven adverse reactions were observed in 27 of the 40 patients (67.5%), but none were clinically significant. Although a disease flare presented as urinary retention in 1 of the untreated patients, all patients completed the study. Serum goserelin was detected up to 12 weeks after the administration of 10.8 mg depot. In conclusion a single dose of 10.8 mg depot showed a satisfactory PD-effect and brought about clinical efficacy persisting for at least 12 weeks and was well tolerated in patients with prostate cancer.

Adenocarcinoma↗
PubMed2001

High expression of the Cap43 gene in infiltrating macrophages of human renal cell carcinomas.

We used suppression subtractive hybridization to identify highly expressed genes in the cancerous region of human renal cell carcinoma (RCC) compared with noncancerous tissue. Nine genes were identified to show increased expression in the cancerous region compared with the noncancerous region. The nine genes included thymosin beta4, secreted protein acidic and rich in cysteine (SPARC), Cap43, ceruloplasmin, serum amyloid A, osteopontin, heat shock protein 90 (HSP90), LOT1, and casein kinase I. Of these 9 genes, in situ hybridization with 10 clinical samples consistently showed a strong expression of Cap43 mRNA in infiltrating macrophages in RCCs, but not in cancer cells proliferating in an alveolar pattern. However, Cap43 mRNA was also apparently detected in epithelial cells of the renal proximal tubuli in noncancerous tissue. The higher expression of the Cap43 gene in the cancerous region of RCCs appears to depend on macrophage infiltration. Moreover, treatment with phorbol ester resulted in enhanced expression of the Cap43 gene in human monocytic cells in vitro. The expression of the Cap43 gene in infiltrating macrophages is discussed in association with the differentiated or activated status of monocyte/macrophage.

Adult↗
PubMed2001

The accumulation of angiostatin-like fragments in human prostate carcinoma.

PURPOSE: Angiostatin, a potent inhibitor of angiogenesis and, hence, the growth of tumor cell metastasis, is generated by a proteolytic enzyme from plasminogen. However, its localization and specific enzymes have yet to be ascertained in human tissue. EXPERIMENTAL DESIGN: To elucidate the generation and the localization of angiostatin in prostate carcinoma, we examined angiostatin generation in a panel of human prostate cancer cell lines and performed immunohistochemistry with the antibodies to angiostatin and prostate-specific antigen (PSA), a potent proteolytic enzyme of angiostatin in 55 cases of prostate carcinoma. RESULTS: We demonstrated that the lysates of human prostate carcinoma cell lines could generate angiostatin-like fragments from purified human plasminogen but could not generate angiostatin in the absence of exogenous plasminogen. The fragmented proteins were reacted with the monoclonal antibody specific for plasminogen lysine-binding site 1 (LBS-1). Immunohistochemically, the intracytoplasmic immunostaining of LBS-1 was positive in 87.3% (48 of 55) of prostate carcinoma cases, and the immunostaining of miniplasminogen was negative in all cases. There was a significant relationship between the positive immunostaining of LBS-1 and Gleason score (P = 0.0007). The intracytoplasmic immunostaining of PSA was positive in 37.0% (20 of 54) of prostate carcinoma cases, but there was no significant relationship between the expression of PSA and Gleason score, or between the positive immunostaining of LBS-1 and PSA. CONCLUSIONS: These findings suggest that angiostatin is generated by prostate carcinoma cells and is accumulated within the cytoplasm. In addition, the generation of angiostatin-like fragments was correlated with tumor grade; however, PSA may not be the only enzyme for angiostatin generation in human prostate carcinoma.

Aged↗