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Biomedical subjects

M L Yu

Publications and source records attributed to M L Yu.

At least 55 records · Page 3Linked to original sources

Treatment of chronic hepatitis C with interferon-alpha: a preliminary report.

Interferon alpha (IFN-alpha) has been indicated to be dramatically effective in some but not all patients with chronic hepatitis C virus (HCV) infection. We investigated prospectively 27 patients of chronic hepatitis C, 12 females and 15 males, treated with IFN-alpha for a better regimen of the therapy and for any effective predictor of response to the treatment. All patients were treated with 3 to 6 million units (MU) of recombinant IFN-alpha 2b (n = 15) or lymphoblastoid IFN-alpha (n = 12) given 3 times weekly for 12 to 36 weeks. Patients with normal alanine aminotransferase (ALT) value during therapy, who sustained this response throughout 6 months follow-up after treatment was completed, were grouped into the complete responders. Patients with normal ALT value during therapy but who relapsed after treatment completed, were grouped as partial responders. Non-responders were defined as patients without normal ALT value during therapy. The rates of complete response, partial response, and non-response were 29.6%, 40.8%, and 29.6%, respectively. The degree of response to IFN-alpha therapy was not related to age, sex, type of IFN-alpha, history of blood transfusion, the state of liver pathology, or pretreatment level of ALT value. The complete responsive rate to IFN-alpha was higher in patients treated with total dose above 215 MU [38.1% (8/21) vs. 0% (0/6), p = 0.06], in patients treated for at least 24 weeks [40% (8/20) vs. 0% (0/7), p < 0.05], and in patients with non-genotype 1b/II HCV infection [40% (8/20) vs. 0% (0/7), p < 0.05]. We concluded that IFN-alpha was effective in the treatment of chronic HCV infection, particularly in those other than HCV genotype 1b/II. A high-dose, and long-duration regimen may be recommended for better response of chronic hepatitis C to IFN-alpha therapy.

Adult↗

The genotypes of hepatitis C virus in patients with chronic hepatitis C virus infection in southern Taiwan.

To investigate the genotype distribution of hepatitis C virus (HCV) in southern Taiwan, the sera from 56 patients with chronic HCV infection were studied. Twenty-nine patients were men and 27 were women. Age ranged from 22 to 65 years (mean, 47.3 +/- 11.4). Eighteen of them had chronic persistent hepatitis, 27 had chronic active hepatitis, and 11 had liver cirrhosis. HCV RNA was detected by reverse transcription-nested polymerase chain reaction using primers derived from the 5'-noncoding region. The genotypes of HCV were determined by amplification of the core region with the type-specific primers as described by Okamoto et al.. All sera were positive for HCV RNA. The prevalence rates of genotypes were as follows: 1b/II, 44.6%(25/56); 2a/III, 41.1%(23/56); 2b/IV, 3.6%(2/56); mixed 1b/I + 2a/III, 5.4%(3/56): mixed 1b/II + 2b/IV, 1.8%(1/56) and type unclassified 3.6%(2/56). The distribution of genotypes was not related to the patients' age, sex, and histological changes. Nevertheless, patients having past history of blood transfusion had a significantly higher rate of HCV type 2a/III infection (72.2% versus 34.2%, p < .05, chi-square test). We concluded that both of the HCV genotypes 1 b/II and 2a/III are predominant types in southern Taiwan and regional HCV genotype distribution may differ even within this island. Selective transmission of specific genotypes may pass along different infectious routes.

Adult↗

A 6-year follow-up of behavior and activity disorders in the Taiwan Yu-cheng children.

OBJECTIVES: The relationship of behavior and activity levels to the interval between outbreak and year of birth and to age of children is explored in Taiwanese children exposed in utero to heat-degraded polychlorinated biphenyls (PCBs)--the Yu-cheng children. Additionally, the relationship of the scores to chemical, physical, and cognitive findings is described. METHODS: With Rutter's Child Behavior Scale A and a modified Werry-Weiss-Peters Activity Scale, 118 Yu-chen children and matched controls were followed biannually from 1985 to 1991. RESULTS: At each year, the Yu-cheng children scored 7% to 43% worse (mean = 23%) than control children on the Rutter scale. At any fixed age, the Yu-cheng children scored 11% to 63% (mean = 28%) worse. The effect for children born later did not differ from that for those born earlier; neither was there any improvement as the children aged. A similar but weaker picture was seen for the activity score. These behavioral findings were not related to physical or cognitive findings or to serum PCB levels. CONCLUSIONS: In utero exposure to heat-degraded PCBs appears to cause mildly disordered behavior and increased activity level; the effect persists over time and is similar in children born up to 6 years after the mothers were exposed.

Case-Control Studies↗

A follow-up study of diabetic Oklahoma Indians. Mortality and causes of death.

OBJECTIVE: To determine the mortality rates and causes of death for diabetic Oklahoma Indian adults by sex and age. RESEARCH DESIGN AND METHODS: This was a cohort follow-up study with baseline examination between 1972-1980 and the mortality follow-up between 1986 and 1989. Mean follow-up time was 10 +/- 4 yr. A quasi-random sample of 1012 (379 men and 633 women) NIDDM American Indians in Oklahoma was performed. Mean age was 52 yr and duration was 7 yr at baseline. Mean degree of Indian blood was 92% (77% full blood). At follow-up, 548 (54%) were alive, 452 (45%) were decreased, and 12 (1%) could not be traced. RESULTS: Death certificates were obtained and coded (ICD-9) for 439 (97%) of the deceased. Mean annual mortality rates were 4.99% for men and 4.17% for women, with an increasing trend with age for both sexes. Compared with the general population of Oklahoma, the observed/expected ratios for number of deaths were 2.92 for men and 4.09 for women (P < 0.0001). The three leading causes of death were circulatory disease (38%), diabetes (24%), and malignant neoplasms (12%). CONCLUSIONS: There is an excessively high mortality among diabetic Oklahoma Indians compared with the general population in the state and with diabetic patients in other populations.

Adult↗

Partial azurophilic granule deficiency. Report of 2 cases with ultrastructural and light-and-electron-microscopic cytochemical observation.

The neutrophils in 2 patients with atopic disease were studied. Ultrastructurally, a number of abnormal azurophilic granules (AG) with low electron-density (Case 1) and secondary lysosomes with "myelinoid membranes" figures (Case 2) were found. Myeloperoxidase (MPO) and acid phosphatase activity were detected by light cytochemical techniques, and showed significantly low values. The deficiency of MPO and abnormal distribution of AG were also demonstrated by electron microscopic cytochemical technique. The neutrophils from the parents revealed changes similar to the patients. This study suggests that since genetic partial deficiency of neutrophil AG enzymes existed, the phagocytosed substances were only partially degraded, leading to accumulation of substances with antigenicity, and became trigger event of atopic disease.

Acid Phosphatase↗

Study on neutrophil enzymes in atopic disease.

Neutrophils (PMN) from 20 patients with atopic disease (atopy), the parents of 8 of the patients and 10 normal controls were studied by light-microscopic cytochemistry. The results revealed that myeloperoxidase (MPO) and acid phosphatase (ACP) activities in PMN in all cases significantly decreased and alkaline phosphatase activity was normal. Parents or parent of 7 of those patients had PMN enzyme deficiency similar to that of the patients. The results indicated that a primary combined and partial deficiency of MPO and ACP in PMN azurophilic granule existed in atopy. It is postulated that the deficiency led to reduction of PMN bactericidal power and delay of bactericidal action. Foreign bodies which were partially degraded could possess antigenic property. This is believed to be the important cytobiological mechanism of the tendency toward infections and formation of sensitive antigen in atopy.

Acid Phosphatase↗

Later recurrence and longer survival among obese patients with renal cell carcinoma.

To investigate the effect of obesity at diagnosis on prognosis of renal cell carcinoma, 360 renal cell carcinoma patients newly diagnosed at 29 hospitals in Oklahoma between January 1, 1981 and December 31, 1984 were followed through December 31, 1987. The Cox proportional-hazard model was used to estimate the hazard ratio, adjusting for other potentially prognostic factors. Both the disease-free interval and the overall survival were longer in patients who were obese (greater than or equal to 120% standard body mass index) at diagnosis. The adjusted-hazard ratio for disease recurrence between obese and nonobese patients was 0.43 (95% confidence interval [CI], 0.19 to 0.98). The obese patients had an adjusted death hazard rate 0.68 times that of the nonobese patients (95% CI, 0.38 to 1.22). Although obesity was reported to increase the risk for renal cell carcinoma, prognosis was no worse and may be better among obese patients with the disease.

Adult↗

[Dammarane-type saponins in leaves of Panax collected in Sichuan].

Three saponins have been isolated from the leaves of Panax japonicus ssp. elegantior var. major (Burkill) Wu et Feng collected in Sichuan, China. They were identified as ginsenoside-Rd (0.5%), ginsenoside-Rg2 (0.025%) and ginsenoside-Rg1 (0.016%), respectively, based on the chemical and spectral analytical data obtained.

Ginsenosides↗

The phosphorus/oxygen ratio of mitochondrial oxidative phosphorylation.

The transport of ATP out of mitochondria and uptake of ADP and Pi into the matrix are coupled to the uptake of one proton (Klingenberg, M., and Rottenberg, H. (1977) Eur. J. Biochem. 73, 125--130). According to the chemiosmotic hypothesis of oxidative phosphorylation this coupling of nucleotide and Pi transport to proton transport implies that the P/O ratio for the synthesis and transport of ATP to the external medium is less than the P/O ratio for the synthesis of ATP inside mitochondria. A survey of previous determinations of the P/O ratio of intact mitochondria showed little convincing evidence in support of the currently accepted values of 3 with NADH-linked substrates and 2 with succinate. We have measured P/O ratios in rat liver mitochondria by the ADP pulse method and by 32 Pi esterification, measuring oxygen uptake with an oxygen electrode, and find values close to 2 with beta-hydroxybutyrate as substrate and 1.3 with succinate as substrate in the presence of rotenone to inhibit NADH oxidation. These values were largely independent of pH, temperature, Mg2+ ion concentration, Pi concentration, ADP pulse size, or amount of mitochondria used. We suggest that these are the true values of the P/O ratio for ATP synthesis and transport by mitochondria, and that previously reported higher values resulted from errors in the determination of oxygen uptake and the use of substrates which lead to ATP synthesis by succinate thiokinase.

Adenosine Diphosphate↗

Influence of age on intrarenal resistive index measurement in normal subjects.

BACKGROUND: We investigated the influence of age on intrarenal arterial resistive index (RI) measurement in 135 normal subjects (71 male, 64 female; age range = 17-68 years, median age = 37 years). METHODS: Each subject underwent color Doppler measurement of the intrarenal RI from three distinct interlobar arteries in the superior, middle, and inferior parts of both kidneys. The mean of six RI values obtained from both kidneys was used for analysis. The correlation of RI with different variables was investigated by linear regression and stepwise multiple linear regression. Variables analyzed were age, systolic blood pressure, diastolic blood pressure, mean blood pressure, pulse pressure, and pulse rate. RESULTS: The results of linear regression showed that age had a significantly positive correlation ( r = 0.276, p = 0.0012) and diastolic blood pressure had a significantly negative correlation ( r = -0.186, p = 0.0311) with the RI. The results of stepwise multiple linear regression showed that the combination of age and diastolic blood pressure could explain approximately 15% of the RI changes ( r(2) = 0.1535). CONCLUSION: Although there is a statistically significant positive correlation between intrarenal RI and age, the correlation is weak. This suggests that the influence of age on RI measurement is small and may be of no clinical importance.

Adult↗