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Biomedical subjects

S Nakata

Publications and source records attributed to S Nakata.

At least 127 records · Page 7Linked to original sources

Angiotensin converting enzyme gene polymorphism and its enzyme activity in serum in young Japanese females.

To assess the potential association between the angiotensin converting enzyme (ACE) gene polymorphism and the activity of the renin-angiotensin system in a Japanese population, we determined the ACE genotype and its enzyme activity in serum in 108 young Japanese females. Genomic DNA was extracted from blood samples and amplified by polymerase chain reaction (PCR). PCR primers flanked the polymorphic region in intron 16 of the ACE gene. The distribution of the DD, ID and II ACE genotypes was 10, 55 and 35%, respectively. The estimated allele frequencies of the deletion and the insertion were 0.375 and 0.625, respectively. The mean serum ACE activity in DD subjects was about 1.4 times that of II subjects (p < 0.01), with ID subjects having intermediate levels (p < 0.05), whereas the renin profile were not statistically different among the three groups. These results indicate a significant association between ACE gene polymorphism and serum ACE activity levels, suggesting a mechanism by which genotype might have a hearing on the physiology of the renin-angiotensin system axis.

Adolescent↗

Effective treatment with low-dose methotrexate pulses of a child of mixed connective tissue disease with severe myositis refractory to corticosteroid.

A 13-year-old girl with mixed connective tissue disease (MCTD) was described. She visited our hospital with recurrent parotid gland swelling, arthritis, and myositis. Sclerodactyly and Raynaud's phenomenon were also defined, and the laboratory findings of high titers of antinuclear antibody (speckled type), positive anti-RNP antibody, positive rheumatoid factor, and hypergammaglobulinemia suggested the diagnosis of MCTD associated with Sjögren syndrome. The muscle weakness and the increased levels of CK prompted us to examine the muscle biopsy and to perform the electromyography, both of which suggested severe muscle inflammation. The siarography and lip biopsy indicated definitively the association of Sjögren syndrome. Corticosteroid therapy including methyl-prednisolone pulses was started, but the effects were limited. The addition of low-dose methotrexate effectively lowered the levels of CK, and gradually improved the muscle strength. Thus, low-dose methotrexate therapy is recommended to the patients with MCTD who have severe myositis refractory to corticosteroid.

Adolescent↗

[Prostate cancer associated with long-term intake of patent medicine containing methyltestosterone: a case report].

An 81-year-old man, admitted with lumbago and pollakisuria, was diagnosed to have stage D2 prostate cancer (T3N2M1). Although the serum level of prostate specific antigen (PSA) was 3,560 ng/ml, serum testosterone (55.6 ng/dl) and luteinizing hormone (LH, 0.8 mIU/ml) levels were very low. Detailed inquiry of the patient revealed a daily intake of patent medicine containing 6-9 mg methyltestosterone for the past 30 years. He was treated by surgical castration and oral chlormadinone acetate. We advised him not to take such androgenic drugs. The disease has been well controlled for 7 months. We stress the importance of checking medication habits of patients with prostate cancer, especially androgen-containing drugs which can be purchased without a physician's prescription. A low serum LH level may be an important finding indicating the intake of androgenic drugs.

Aged↗

Chemisorption of proteins and their thiol derivatives onto gold surfaces: characterization based on electrochemical nonlinearity.

This study was conducted to monitor the electrochemical responses of two proteins (bovine serum albumin (BSA) and gelatin) and their thiol derivatives adsorbed onto gold (Au) electrodes, which were analyzed by a "nonlinear" impedance method. A sinusoidal voltage is applied to a protein-containing aqueous solution and the waveform of the output current is analyzed by fast Fourier transformation (FFT). The intensities of the higher harmonics in the FFT varied with the species of protein and their thiol derivatives, and with time. From the higher harmonics, voltage-dependent capacitance and conductance were quantitatively evaluated to differentiate the state of adsorbed protein. Adsorption and desorption characteristics of BSA and its thiol derivative on the Au surface were continuously measured by a quartz crystal microbalance (QCM) in situ. The microscopic state of thiol-derivatized BSA adsorbed onto the Au surface was imaged by atomic force microscopy (AFM). In general, thiol-derivatized proteins were tightly adsorbed on the Au surface and showed no desorption. The present electrochemical measurements clearly differentiated adsorption characteristics of physically adsorbed (physisorbed) and chemically adsorbed (chemisorbed) proteins on Au surfaces.

Journal Article↗

The epidemiology of human calicivirus/Sapporo/82/Japan.

Based on genome analysis of the RNA-dependent RNA polymerase region, it has been proposed that human caliciviruses (HuCV) can be classified into at least three genogroups: genogroup I is represented by Norwalk virus (NV), genogroup II by Snow Mountain agent (SMA) and genogroup III by HuCV/Sapporo/82/Japan (HuCV/Sa/82/J) virus. HuCV/Sa/82/J strain is genetically unique and more closely related to animal caliciviruses than are other known HuCVs, such as NV and SMA. HuCV/Sa/82/J strain was detected in four outbreaks of HuCV gastroenteritis occurring between 1977 and 1982 in an infant home in Sapporo. The HuCVs detected from these four outbreaks all showed a typical "Star of David" configuration by electron microscopy (EM), and they were identical antigenically and genetically. This strain has also been detected in other prefectures in Japan, as well as in the USA, UK, Saudi Arabia and Kenya. Seroepidemiological studies have shown a worldwide distribution of this virus, including Japan, USA, UK, Southeast Asia, Canada, China and Kenya. This virus has been circulating in Sapporo for at least 19 years (1977-1995). HuCV/Sa/82/J strain is thought to be one of the common causes of viral gastroenteritis worldwide. The HuCV/Sa/82/J strain has been detected mainly in infants. Age-related prevalence of antibody to this strain also shows that infections commonly occur in children less than 5 years old, although viruses in the NV and SMA genogroups commonly infect adults. The pattern of acquisition of antibodies to strain HuCV/Sa/82/J is similar to that of other common viral infections. HuCV/Sa/82/J strain is unique virologically and clinically among caliciviruses.

Age Factors↗

Dot blot hybridization with a cDNA probe derived from the human calicivirus Sapporo 1982 strain.

A dot blot hybridization assay was developed for detection of human calicivirus/Sapporo/82/J (HuCV/Sa/82) or strains closely related to HuCV/Sa/82 in stool specimens. The cDNA derived from the RNA-dependent RNA polymerase (RDRP) region of HuCV/Sa/82 was used as a positive probe and the pBR322 DNA as a negative control probe. Both probes were labeled with digoxigenin and the products of hybridization reaction were detected with an anti-digoxigenin antibody-alkaline phosphatase conjugate. This assay was specific for HuCV/Sa/82 and for HuCV antigenically related to HuCV/Sa/82. The lower limit of sensitivity of this assay was estimated to be about 10(5) physical particles or 10 pg of cDNA, similar to that of the previously developed ELISA for HuCV. In 1273 stool specimens obtained from children with acute gastroenteritis in Sapporo, Japan, 110 (8.6%) contained small round structured viruses by EM and 23 (1.8%) were positive for HuCV antigenically related to HuCV/Sa/82 by either the hybridization assay or ELISA. A higher positive rate was obtained with the dot blot assay (21%) than by ELISA (10%), suggesting that the dot blot assay either detects HuCV more broadly than the ELISA or detects HuCV covered with fecal antibodies which interrupt antigen-antibody reactions in the ELISA. Negative results for detection of Norwalk virus (NV) cDNA and feline calicivirus (FCV) RNA by both this assay and the ELISA indicated that the HuCV/Sa/82 strain is distinct antigenically and genetically from NV and FCV.

Acute Disease↗

Outbreaks of nosocomial rotavirus gastro-enteritis in a paediatric ward.

UNLABELLED: Faecal samples were collected from patients with gastro-enteritis during two winter seasons on a paediatric ward. Three outbreaks of nosocomial rotavirus gastro-enteritis were identified by latex agglutination and the virus strains were characterized by polyacrylamide gel electrophoresis of the genome nucleic acid and by subgrouping and serotyping enzyme-linked immunosorbent assays (ELISA). One outbreak was caused by serotype 1 rotavirus, one by serotype 2 and the remaining outbreak was caused by a mixture of serotypes 1 and 4. Identical electrophoretic patterns of the rotavirus genome in each outbreak combined with the ELISA results indicate that these three outbreaks were hospital-acquired cases. The index cases in the three outbreaks were community-acquired and one of two index cases in the second outbreak was hospital-acquired. On each occasion, susceptible roommates were easily infected from the index cases and then cross-infection occurred in the paediatric ward. Possible vehicles were the medical staff, especially doctors, parents of infected patients and infected patients who were moved to other rooms. One patient who had been treated with a series of antitumour therapies excreted rotaviruses in faeces for a long time period and probably played a role as a source of the outbreak. Moreover, some patients still excreted rotaviruses in their normal stool 1 week after recovery from gastro-enteritis. These findings indicate that continual examination of stool samples for rotaviruses until they are negative may be important to prevent the spread of rotavirus infection. CONCLUSION: Nucleic acid analysis and serotyping ELISA are useful tools for analyzing nosocomial rotavirus gastro-enteritis and important to prevent the spread of rotavirus infection in institutions.

Child↗

Isolation of group B porcine rotavirus in cell culture.

While group A and C rotaviruses have been grown in cell culture, group B rotavirus has never been cultured. In this study we successfully isolated porcine group B rotavirus in swine kidney cells. Pancreatin treatment is essential for the propagation of group B rotavirus.

Animals↗

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↗

Correlation analysis between bladder cancer and cigarette smoking in various countries.

Cigarette smoking is considered to be a risk factor of bladder cancer. We investigated the relationship between bladder cancer mortality rates and cigarette smoking prevalence in various countries, and examined whether only the difference of smoking prevalence could explain the difference of mortality rates of bladder cancer in each country or not. The age-adjusted mortality rates from bladder cancer were high in European countries and low in Asian countries. The sex ratios ranged between 2 to 6 in most of the countries. For 20 countries, the mortality rate from bladder cancer was not correlated with the cigarette smoking prevalence. However, when the analysis was restricted to 16 countries in Europe, North America and Oceania (Caucasians), the correlation coefficients between them were high, being 0.68 (p < 0.01) in males and 0.49 (0.05 < p < 0.1) in females. In both Japan and the United States, cigarette smoking prevalence declined while the incidence of bladder cancer increased in males, both being stable in females. Race might be considered to be a strong risk factor of bladder cancer, followed by the prevalence of cigarette smoking. It is necessary to follow the changes of incidence rates of bladder cancer in the future to evaluate the influence of cigarette smoking.

Age Factors↗

[Regional and chronological differences of urogenital cancer deaths in Japan].

PURPOSE: We investigated the changing patterns of urogenital cancer deaths during the past 22 years in Japan. METHODS: We analyzed patients that died from cancer of the prostate, bladder and kidney between 1973-1994. Age-adjusted death rates (adjusted to the world population), standardized mortality ratios (SMR) according to each prefectures and age-specific death rates for each types of cancer were calculated and changes in these patterns were analyzed. RESULTS: Age-adjusted death rates for cancer of the prostate increased from 2.29 in 1973 to 4.36 in 1994, a 1.9-fold increase. Death rates for cancer of the bladder were stable in males and declined in females. Death rates for cancer of the kidney (15 years or older) increased from 1.45 in 1973 to 2.72 in 1994, a 1.9-fold increase in males, and tended to increase in females as well. In the SMR analysis by prefecture, distribution in 1973-84 (former period) and that in 1985-94 (later period) were similar, and characteristic features were observed for each type of cancer. Age-specific death rates for cancer of the prostate and bladder rose by an index power of age, but that for cancer of the kidney reached a plateau or decreased after an index power increase to a certain age. The rate of increase in age-specific death rates (later period/former period) rose according to age, especially 70 years or older, in cancer of the prostate and kidney in both males and females. However, age-specific death rates in the later period from cancer of the bladder was higher only in patients 85 years or older, but was lower in other age groups. CONCLUSIONS: Death rates for cancer of the prostate and kidney (15 years or older) tended to increase, while that of the bladder remained stable or decreased. It is expected that detection and treatment of these disease can be improved by utilizing these epidemiologic information.

Adult↗

[Experimental study on resuscitation and salvage of myocardial function (RSMF) after normothermic ischemic arrest].

We studied in anesthetized dogs, the effects of cardiopulmonary bypass with normothermic blood, crossclamping of the aortic root, and continuous warm blood cardioplegia as a part of circulatory support on the ability of the recovery of the deteriorated myocardial function, and compared this method with the circulatory support under empty beating stage. Eleven dogs were subjected to the deteriorated myocardial function by 30 minute normothermic ischemic arrest and myocardial function was measured (baseline function). In 5 dogs (Group A), coronary perfusion of 5 ml/kg/min with normothermic blood was established under empty beating state. In other 6 dogs (Group B), the aorta was then clamped and 30 minute infusion of warm blood contained 15 mEq/l of potassium and 2 mEq/l of Magnesium was given by 2.5 ml/kg/min as a part of circulatory support. After this, aortic clamp was released and coronary perfusion of 5 ml/kg/min with normal warm blood followed under empty beating state. Cardiac function was measured at the periods of 40, 60 and 90 minutes of circulatory support and compared between the two groups. The parameters of left ventricular function (developed pressure, dp/dt, -dp/dt) were deteriorated by 30 minutes ischemia by about 50% compared with baseline function. In Group a, they improved gradually along with the duration of circulatory support and 90 minutes were required to return to the baseline function. In Group B, however, their % recovery reached 100% at the period of 40 minutes and maintained over 100% thereafter. RSMF could recover myocardial function from ischemic damage more quickly and effectively compared with circulatory support under empty beating state.

Animals↗

[Continuous systemic venous oxygen saturation monitoring immediately after Fontan procedure].

Changes in cardiac output (CO), systemic venous oxygen saturation (SvO2), systemic oxygen consumption, and urinary output immediately after Fontan procedure were measured in 10 patients at the intensive unit (ICU) to assess the effects of aorusal from anesthesia, hypothermic management, and respiratory condition. The measurements were taken at the following phases; phase A in deep sedation under hypothermia (33-35 degrees C rectal temperature) and controlled ventilation; phase B in mild sedation under normothermia and controlled ventilation; phase C when awake under normothermia and assisted ventilation; phase D when awake under assisted ventilation; phase D when awake under normothermia immediately after extubation; and phase E 24 hours after extubation. Oxygen delivery (O2 Del.) and fractional oxygen fractions were calculated in each phase. Two patients whose SvO2 values were below 55% during the postoperative course needed reoperation for atrioventricular valve regurgitation in one case for PV stenosis in the other case. CO increased significantly (p < 0.05) after extubation (phase D), compared with that of controlled ventilation (phase B). Under hypothermia (phase A), urinary output was relatively higher with lower CO. There was a significant correlation between SvO2 and CO (R = 0.61) in phase A, however there was no correlation in phase E. Fractional oxygen extraction in phase A was significantly lower than in phase B. In conclusion, the continuous SvO2 measurements reflected real-time changes in cardiac output in the immediate post-Fontan patients. Induced hypothermia was beneficial in increasing urinary output presumably through the correction of maldistribution of cardiac output in post-Fontant patients. Arousal from anesthesia and spontaneous ventilation seemed advantageous for increasing cardiac output, hence, early extubation should be encouraged in the management of post-Fontan patients.

Blood Gas Monitoring, Transcutaneous↗