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Biomedical subjects

S Nakano

Publications and source records attributed to S Nakano.

At least 307 records · Page 17Linked to original sources
PubMed1996

Recurrent left atrial myxoma in a patient with a twin fetus pregnancy.

We experienced a case of a recurrent left atrial myxoma in a pregnant woman with twin fetuses. Normal healthy twins weighing 1430 and 1190 gm were delivered by cesarean section performed under epidural anesthesia at 32 weeks gestation. Neither cardiac failure nor embolisms were observed during pregnancy or delivery. The left atrial myxoma was removed surgically one week after delivery. The infants and mother remain in good health. According to previous reports and our present observations, the decision for cardiac surgery during pregnancy should be based on the maternal and fetal status.

Adult↗
PubMed1996

Hyperglycemia decreases dehydroepiandrosterone in Japanese male with impaired glucose tolerance and low insulin response.

Recent studies indicate that experimentally induced hyperinsulinemia may reduce serum dehydroepiandrosterone (DHEA) and dehydroepiandrosterone-sulfate (DHEA-S). Serum DHEA and DHEA-S decrease in diabetic patients, but the mechanism by which hyperglycemia decreases DHEA and DHEA-S is unknown. In this study, we investigated the effect of hyperglycemia on DHEA and DHEA-S in impaired glucose tolerance (IGT) by means of the 75g-oral glucose tolerance test (OGTT). We selected 30 male IGT patients receiving diet therapy only, whose insulinogenic Index was under 0.3. Oral glucose challenge significantly reduced DHEA (P = 0.0001) and DHEA-S (P < 0.05) at 60 and 120 min after OGTT. Setting the value of DHEA and DHEA-S at time zero as 100%, we calculated the DHEA and DHEA-S values at 60 and 120 min after OGTT as %DHEA(-S) 60 min and %DHEA(-S) 120 min, respectively. DHEA and DHEA-S at time zero showed no correlation with BMI, HbA1c, the sum of insulin values (sigma IRI) or the area under the curve of plasma glucose (AUC). We found decreases in %DHEA 60 min (r = -0.411, P < 0.05), %DHEA-S 60 min (r = -0.508, P < 0.01) and %DHEA-S 120 min (r = -0.393, P < 0.05) as AUC increased, but sigma IRI showed no correlation with %DHEA(-S) 60 min or %DHEA(-S)120 min. We conclude that the depression of DHEA and DHEA-S after OGTT is attributable to hyperglycemia in male Japanese IGT with low insulin response.

Dehydroepiandrosterone↗
PubMed1996

Depression of dehydroepiandrosterone in Japanese diabetic men--comparison between non-insulin-dependent diabetes mellitus and impaired glucose tolerance.

Hyperglycemia is known to reduce dehydroepiandrosterone (DHEA) circulating levels; however, the mechanism by which hyperglycemia decreases DHEA is not elucidated. In this study, serum DHEA and DHEA sulfate (DHEA-S) levels were compared in 50 men with non-insulin-dependent diabetes mellitus (NIDDM) and 50 age-matched men with impaired glucose tolerance (IGT) receiving only diet therapy. Serum concentrations of DHEA and DHEA-S in the NIDDM group were significantly lower than in the IGT group (7.8 and 9.7 nmol/l vs 3.4 and 4.9 mumol/l, respectively; p < 0.01) but there was no significant difference in immunoreactive insulin between the two groups. When the results from both groups were combined, HbA1C was significantly inversely related to DHEA (r = -0.243, p < 0.01) and DHEA-S (r = -0.305, p < 0.01). Immunoreactive insulin showed no correlation with DHEA and DHEA-S. Multiple regression analysis showed that HbA1C was independently negatively related to both DHEA and DHEA-S. We conclude that hyperglycemia may decrease serum DHEA and DHEA-S in Japanese men with NIDDM, but the depression of DHEA(-S) is independent of serum insulin level.

Dehydroepiandrosterone↗
PubMed1996

Modulation of transforming growth factor-beta secretion from malignant glioma cells by interleukin-1 beta.

Malignant glioma cells secrete transforming growth factor-beta (TGF-beta) which has potent immunosuppressive properties. We investigated the effect of interleukin-1 beta (IL-1 beta) on TGF-beta secretion from malignant glioma cells in vitro. T98G glioblastoma cells were treated with various doses of IL-1 beta and the TGF-beta activity in the supernatant was determined using a specific bioassay. Six other human malignant glioma cell lines were also treated with 1000 U/ml of IL-1 beta, and the TGF-beta activity in the supernatants was determined. The effect of IL-1 beta on the growth of tumor cells was also assessed by a bioassay using crystal violet which reflects the actual cell number in the plate wells. IL-1 beta treatment resulted in inhibition of TGF-beta secretion in two malignant glioma cell lines. TGF-beta secretion from T98G cells was suppressed by IL-1 beta in a dose-related manner. However, IL-1 beta treatment resulted in an obvious increase (> 20%) of TGF-beta secretion in two tumor lines, and a slight increase (< 20%) in three tumor lines. IL-1 beta did not affect the growth of four malignant glioma cell lines, and only slightly affected the growth of the other three cell lines. IL-1 beta modulates TGF-beta secretion from malignant glioma cells, but not in a consistent way.

Cell Division↗
PubMed1996

Transforming growth factor-beta inhibits interferon-gamma secretion by lymphokine-activated killer cells stimulated with tumor cells.

The effect of transforming growth factor-beta (TGF-beta) secreted by glioblastoma (T98G) cells on the secretion of interferon-gamma (IFN-gamma) by lymphokine-activated killer (LAK) cells stimulated with tumor cells was investigated in cocultures of LAK and Daudi cells supplemented with T98G culture supernatant, T98G culture supernatant preincubated with anti-TGF-beta 1 and anti-TGF-beta 2 neutralizing antibodies, anti-TGF-beta 1 and anti-TGF-beta 2 antibodies, or natural human TGF-beta 1 or recombinant human TGF-beta 2. LAK cells were incubated with anti-TGF-beta 1 and anti-TGF-beta 2 antibodies, and with T98G cells of which the supernatant contained both active and latent forms of TGF-beta 1 and TGF-beta 2, with or without neutralizing antibodies. Addition of the supernatant from T98G cells to LAK/Daudi culture caused inhibition of IFN-gamma secretion by LAK cells. The inhibition was abolished by pretreatment of the supernatants with anti-TGF-beta antibodies. Addition of TGF-beta 1 and TGF-beta 2 to the LAK/Daudi culture inhibited IFN-gamma secretion by LAK cells in a dose-dependent manner. Addition of anti-TGF-beta antibodies to the LAK culture resulted in increased IFN-gamma secretion. T98G cells failed to stimulate LAK cells to secrete more IFN-gamma. Addition of anti-TGF-beta antibodies to the LAK-T98G culture resulted in increased IFN-gamma secretion by LAK cells. These results suggest that most malignant glioma cells which secrete high levels of TGF-beta can inhibit IFN-gamma secretion by LAK cells even after tumor cell stimulation.

Brain Neoplasms↗
PubMed1996

Surface contamination of titanium by abrading treatment.

This study investigated the contamination of abraded Ti surfaces. Using a polishing machine, specimens were abraded with waterproof SiC grit papers under water cooling. The abraded surfaces were examined using element analysis, X-ray diffraction, and hardness tests. Contaminant deposits with dimensions reaching about 30 microns were observed throughout the surface. In these deposits, Ti was apparently reduced by about 10% and replaced by Si and O. The chemical bond state of the Si was similar to that of SiC or a titanium silicide. The O was solute in Ti, which increased the surface hardness. The contaminant deposits were amorphous or very thin. The contamination of Ti, the extent of which was related to hardness, resulted from a reaction with abrasives.

Dental Polishing↗
PubMed1996

Possible segregation caused by centrifugal titanium casting.

The possibility of the segregation under solidification process using a centrifugal casting machine was investigated using an electron probe microanalyzer with elemental distribution map, line analysis and quantitative analysis. When a very small quantity of platinum was added to local molten titanium during the casting process, macroscopic segregation was observed under conditions of density difference of 0.1 g/cm3 at the most, confirming that the centrifugal force of the casting machine is extremely strong. When a Ti-6Al-4V alloy was cast, however, no macroscopic segregation was observed. The centrifugal force of the casting machine examined in the present study hardly results in the body-force segregation in this titanium alloy.

Alloys↗
PubMed1996

[The clinical evaluation of hepatic arterial infusion chemotherapy in patients with liver metastases from colorectal cancer employing an implanted port system].

Between 1986 and 1994, 66 patients with unresectable liver metastases from colorectal cancer were treated by repeated hepatic arterial infusion chemotherapy employing an implantable port system. In this study, 44 patients who received intermittent hepatic arterial infusion of high dose 5-FU (1000mg/m2) were analysed according to a response rate, survival rates, developments of extrahepatic lesions, periods of hepatic arterial infusion, and the rates at home. Two cases (4.5%) achieved a complete response (CR) and 27 cases (61.4%) a partial response (PR). The overall one-year and two-year survival rates were 56.7% and 37.8% respectively. The 50% survival time for all patients was 17.2 months. During the course of observation, extrahepatic lesions developed in 16 of the 39 patients (41.0%) and many responders died due to deterioration of extrahepatic lesions. The over all rates at home were more than 85%. Hepatic arterial infusion of the 5-FU at 1000mg/m2 every week showed a high response rate in colorectal cancer patients with hepatic metastases, and the responders showed a low rate of death due to the hepatic metastases. However, in many patients the prognosis-determining-factor was extrahepatic lesions. Thus, countermeasures were necessary for extrahepatic lesions.

Aged↗
PubMed1996

Effect of daily administration period of natural alpha-interferon in patients with chronic hepatitis C.

OBJECTIVE: A randomized, controlled trial was performed to study the effect of the period of daily administration of interferon therapy in patients with chronic hepatitis C. PATIENTS AND METHODS: Sixty-three patients were administered a total dose of 480 MU of natural alpha-interferon, 6 MU each day. In 32 cases, interferon was given daily for 2 wk, followed by intermittent administration (three times a week) for 22 wk. The other 31 patients received daily administration for 8 wk, followed by intermittent administration (twice a week) for 12 wk. The responses were based on the normalization of ALT and the clearance of hepatitis C virus. RESULTS: Although ALT normalized in 37 patients during the administration of interferon, it relapsed after the end of interferon therapy in 20 patients. The other 17 patients achieved sustained normalization of ALT and clearance of hepatitis C virus RNA. Responses did not differ according to the administration period of interferon. CONCLUSIONS: Prolonged daily administration did not improve the responses to interferon therapy when the total dose was the same.

Alanine Transaminase↗
PubMed1996

[Portal embolization using lipiodol-gelatin sponge].

Gelatin sponge moistened with lipiodol was prepared for use in portal embolization to improve percutaneous transhepatic portal embolization as preoperative management of patients undergoing extensive liver resection. For one sheet of gelatin sponge (20 x 60 x 7mm)0.5ml of lipiodol was used. Five sheets cut to 2mm square pieces and mixed with physiological saline solution were injected into the right portal vein. This embolic material proved safer and more reliable than gelatin sponge mixed with water-soluble contrast medium, because it provided sufficient opacification to grasp the extent of embolization and prevented back flow.

Embolization, Therapeutic↗
PubMed1996

[Giant isolated extracadiac unruptured aneurysm of the right coronary sinus of valsalva--a case report].

A giant isolated extracardiac unruptured aneurysm of the right coronary sinus of Valsalva was detected incidentally in a 24-year-old man with clinical findings of Ehlers-Danlos syndrome. The right coronary artery was occluded at its ostial resion. Surgical correction was performed by obliterating the orifice of the aneurysm with a Dacron patch. Microscopic examination of the diseased aortic wall revealed absence of medial elastic fibers. Collective review of 19 reported similar cases revealed that reports concerning unruptured, isolated giant sinus of Valsalva aneurysm were rare, especially in young patients, and that the aneurysm of this patient was the largest.

Adult↗
PubMed1996

[Radiologic-pathologic correlation between tumor edge and surrounding inherent structures in peripheral lung cancer].

PURPOSE: To evaluate the radiologic-pathologic relationship between the tumor edge of peripheral lung cancers and surrounding normal structures. MATERIALS AND METHODS: Tissue samples from 16 lung cancers with diameters less than 2 cm were examined: 7 adenocarcinomas, 5 squamous cell carcinomas, 2 small cell carcinomas, 1 large cell carcinoma, and 1 that had metastasized to the lung. Inflation-fixed lung specimens containing tumor tissue were sliced to a thickness of 2 mm: The tumor edge of each section was traced under a stereomicroscope and its relationship to marginal structure, including bronchi, pulmonary arteries, and pulmonary veins containing interlobular septa, was analyzed. The tumor edge and marginal structures were classified into four types: Type 1, clear margin formed by marginal structures; Type 2, tumor involving the marginal structures; Types 3 and 4, marginal structures penetrating the tumor with and without a notch, respectively. RESULTS: Type 1 was found in 23 of 47 pulmonary arteries (49%), 23 of 49 bronchi (47%), and 12 of 31 pulmonary veins or interlobular septa (39%). Type 2 was found in 11% (14/127), Type 3 in 15% (19/127) and Type 4 in 28% (36/127) of marginal structures. Type 1 was common in all histological types of carcinomas studied. CONCLUSION: In small peripheral lung cancers, the tumor edge sometimes has a clear margin formed by surrounding structures such as interlobular septa. This can make it difficult to differentiate benign from malignant lesions.

Adenocarcinoma↗
PubMed1996

Susceptibility-weighted MR for evaluation of vasodilatory capacity with acetazolamide challenge.

PURPOSE: To investigate cerebral vasodilatory capacity by acetazolamide challenge in healthy subjects and in patients with chronic occlusive cerebrovascular disease by using susceptibility-weighted gradient-echo MR imaging. METHODS: Eight patients with chronic occlusive cerebrovascular disease and four healthy volunteers were studied with susceptibility-weighted MR imaging before and after intravenous administration of 1000 mg of acetazolamide. Signal intensities were measured as a function of time in several regions of interest defined on anatomic images. In all patients with chronic occlusive cerebrovascular disease, acetazolamide challenge and resting regional cerebral blood flow were also evaluated with single-photon emission CT (SPECT). RESULTS: In healthy volunteers, signal intensities began to increase 3 to 4 minutes after acetazolamide administration, with a continuous increase during the subsequent 10 minutes. The effect lasted for approximately 45 minutes after administration. In patients with chronic occlusive cerebrovascular disease, signal changes on susceptibility-weighted MR images of occluded areas with normal vasodilatory capacity on SPECT images did not differ from signal changes of nonocclusive areas. In those patients with changes that reflected diminished vasodilatory capacity, the MR images showed a lower percentage of signal changes after acetazolamide administration than those in normally perfused areas. CONCLUSION: Susceptibility-weighted MR imaging offers an alternative method for estimating vasodilatory capacity.

Acetazolamide↗
PubMed1996

Ophthalmic artery flow velocity after physical exercise in healthy men.

This study was conducted to evaluate the effects of physical exercise on blood flow velocity in the ophthalmic artery of healthy men. Color Doppler imaging, which permits rapid noninvasive imaging of the ophthalmic artery, was performed in 11 healthy male adult volunteers to compare pre- and post-exercise measurements of blood flow velocity. After submaximal physical exercise, systolic blood flow velocity (Vmax) and time-averaged blood flow velocity (Vmean) increased significantly, but returned to pre-exercise levels 5-10 minutes after the completion of physical exercise. There were no significant changes in minimum end-diastolic blood flow velocity (Vmin), resistance index (RI) or pulsatility index (PI). The RI and PI parameters are considered to reflect vascular resistance. Our results indicate that submaximal physical exercise increased the blood flow velocity, but did not alter the resistance index of the ophthalmic artery.

Adult↗
PubMed1996

[Comparative trial of granisetron alone and granisetron plus methylprednisolone for prevention of nausea and vomiting during cancer chemotherapy].

A crossover clinical trial between granisetron alone and granisetron combined with methylprednisolone (MPL) was undertaken for the prevention of nausea and vomiting during chemotherapy, including cisplatin, in 12 patients with advanced primary and metastatic lung cancer. The antiemetic effect was obtained in 91.7% (11/12 cases) of patients receiving granisetron alone compared to 100% (12/12 cases) of patients receiving the combination of granisetron plus MPL. Complete control of anorexia was achieved in 91.6% (11/12 cases) of patients receiving the combination compared to 58.3% (7/12 cases) of patients receiving granisetron alone. Moreover there was a significant improvement of delayed clinical symptoms including nausea, vomiting, and anorexia in the patients receiving the combination of granisetron plus MPL. Our data suggest that the antiemetic effect of the combination of granisetron plus MPL is superior to granisetron alone in patients receiving cancer chemotherapy.

Adult↗
PubMed1996

[Comparison between high-resolution computed tomography and 99mTc-technegas SPECT pulmonary emphysema].

Scintigraphy with 99mTc-technegas was recently introduced for clinical imaging of lung ventilation. This method has been found to be useful in emergencies, to be more suitable for single photon emission computed tomography (SPECT) than other agents used in ventilation scintigraphy, and could reveal abnormalities in ventilation more easily than high resolusion computed tomography (HRCT) in pulmonary emphysema. We compared 99mTc-technegas SPECT with HRCT in six regions: the right upper, middle, and lower lobes, the left upper lobe, the lingula, and the left lower lobe, in 15 patients with pulmonary emphysema. Patients with centrilobular emphysema tended to show stronger changes in upper lobes than in lower lobes on both 99mTc-technegas SPECT and HRCT. Some regions showed no change on HRCT but various changes on 99mTc-SPECT. Patients with panlobular emphysema showed severe changes on 99mTc-SPECT in lower lung fields in which well-demarcated areas of low attenuation were not seen on HRCT. We conclude that 99mTc-SPECT is useful for detecting early changes and panlobular changes in pulmonary emphysema.

Adult↗
PubMed1996

Altered circadian blood pressure rhythm and progression of diabetic nephropathy in non-insulin dependent diabetes mellitus subjects: an average three year follow-up study.

BACKGROUND: In addition to autonomic dysfunction, diabetic nephropathy has been identified as another factor inducing a reversed circadian blood pressure (BP) rhythm in diabetic subjects. This study was carried out to assess the relationship between alterations in circadian BP rhythm and progression of diabetic nephropathy in subjects with non-insulin dependent diabetes mellitus (NIDDM). METHODS: Ambulatory 24-hour BP, 24-hour urinary albumin excretion rate (UAE), and plasma hormonal factors were measured during an average 3-year follow-up in 16 hospitalized subjects with NIDDM. Twelve age-matched control subjects were also studied. RESULTS: During an average 3-year follow-up, diabetic subjects had no significant progression of severe nephropathy and/or somatic neuropathy and showed no transition from a normal to a reversed mean blood pressure (mBP) pattern. However, mBP during whole day or nighttime, but not daytime, at baseline in diabetic subjects was high as compared with control subjects exhibiting an increased night/day mBP ratio and a decreased night/day mBP difference. The mBPs during various time periods (whole day, daytime, and nighttime) at follow-up in diabetic subjects were more elevated than those at baseline, showing a more increased night/day mBP ratio and a more decreased night/day mBP difference. In diabetic subjects, UAE during follow-up was increased, and UAE increments were well correlated with changes in mBP during whole day and nighttime. Plasma renin activity (PRA) and plasma aldosterone (PA) were decreased, while plasma alpha-atrial natriuretic peptide (ANP) was increased at follow-up, compared with at baseline. The mBP increments during various time periods were well correlated with changes in these hormonal factors, and UAE increments were well correlated with changes in PA and plasma ANP. CONCLUSIONS: The altered circadian BP rhythm observed in diabetic subjects may occur at the early stage of diabetic nephropathy with opposite changes in plasma renin-aldosterone and plasma ANP.

Blood Pressure↗