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Biomedical subjects

M S Ho

Publications and source records attributed to M S Ho.

At least 55 records · Page 3Linked to original sources

Early interferon therapy and abortion of posttransfusion hepatitis C viral infection.

We studied the role of an "early" 4-month course of interferon therapy on posttransfusion viral hepatitis C (PTH-C). Paired serum samples of 51 consecutive recipients, taken before and 7-20 days after blood transfusion, were prospectively tested for hepatitis C virus ribonucleic acid (HCV RNA) using the polymerase chain reaction assay. Seven recipients experienced seroconversion of HCV RNA after transfusion. Two of the seven patients underwent an early 4-month course of interferon alpha therapy at a dose of 3 mU per day for 5 days during the first week, then three times a week for the subsequent 15 weeks. The first patient was treated at a very early stage of acute PTH-C and responded well to interferon therapy. Acute PTH-C in the second patient was prevented by interferon therapy. Both patients had normal serum alanine aminotransferase levels and tested negative for anti-HCV and HCV RNA 12 months after the end of treatment. Four of the five patients not on interferon therapy developed abnormal serum alanine aminotransferase activities more than five times the normal upper limit (383 +/- 143 IU/L) at 2-18 weeks after transfusion. All four patients experienced seroconversion of anti-HCV, and three patients developed chronic hepatitis. This study suggests that early long-term interferon therapy has the potential to prevent PTH-C.

Adult↗

Increased IgM-containing circulating immune complexes in patients co-infected with hepatitis C and hepatitis B.

To assess the role of circulating immune complexes (CIC) in chronic hepatitis C virus (HCV) infection, the relative frequency of CIC was determined in 60 patients with chronic hepatitis C alone, 19 patients co-infected with hepatitis B and C, 15 asymptomatic HCV carriers, and 54 healthy controls. Levels of CIC were determined with immunoglobulin-specific C1q-binding and conglutinin (K)-binding immune complex assays. Although there was no statistical difference in the levels of each type of CIC between asymptomatic HCV carriers and healthy controls, elevated levels of CIC containing IgM and IgG were common in patients with chronic HCV infection. Compared to patients with hepatitis C alone, patients co-infected with hepatitis B and C have a higher frequency of abnormal IgM-containing CIC and significantly higher levels of IgM-containing CIC. CIC levels in patients with chronic active hepatitis were significantly higher than those in patients with chronic lobular hepatitis or chronic persistent hepatitis. In conclusion, although CIC containing IgM and IgG were common in patients with chronic hepatitis C, abnormal IgM-containing CIC are the major types of CIC in patients co-infected with hepatitis B and C. An immune-mediated mechanism may play a role in the pathogenesis of chronic hepatitis C.

Adult↗

A family cluster of an immune escape variant of hepatitis B virus infecting a mother and her two fully immunized children.

A hepatitis B virus (HBV) immune escape variant which results from a substitution of glycine by arginine at position 145 (arginine-145) in the immunodominant neutralization epitope of the S protein was found to infect one child in a seroepidemiologic survey of 1,812 vaccinated children. The child's mother and a younger brother were also infected by the same HBV variant, despite a greater than accepted level of protective antibody (anti-HBV surface antigen) in both the index child (30 mIU/ml) and the brother (> 20,000 mIU/ml). Our findings suggest the perinatal or horizontal transmission of the arginine-145 HBV variant from mother to child, but the ability of this variant to propagate among the vaccinated children remains unknown.

Adult↗

Bladder involvement in patients with colorectal carcinoma.

Twenty-seven patients underwent concomitant partial cystectomies out of a total of 542 patients with colorectal carcinoma operated on between October 1989 to December 1991. There were 19 males and 8 females with a median age of 63.7 years (range 44-80). The patients were followed up for a median of 40.2 months (range 27-75 months). Histological invasion into the bladder was found in only 26% of the tumours. Eighty-five percent of the patients with carcinomatous invasion had preoperative urological symptoms whilst only 20% of those with inflammatory adhesions had urological symptoms. Four percent of the patient were Dukes' A, 50% Dukes' B, 42% Dukes' C and 4% Dukes' D. Twenty (74%) patients are alive without evidence of local or distant metastasis. One has local recurrence and another, distant metastasis. Five patients have died. The prognosis of patients with colorectal cancer and bladder involvement appears to be similar to those without bladder involvement provided clear margins are obtained.

Adult↗

Hepatitis B and C virus infection as risk factors for hepatocellular carcinoma in Chinese: a case-control study.

To assess whether hepatitis B and C virus infection were risk factors for hepatocellular carcinoma (HCC), antibody to hepatitis C virus (anti-HCV), hepatitis B surface antigen and e antigen (HBsAg and HBeAg) were tested in 150 HCC patients. Another 150 case-control pairs matched individually by sex and age were also enrolled. Univariate analysis demonstrated that both the anti-HCV and the carrier status of HBsAg and HBeAg were significantly associated with HCC. Multi-variate analysis revealed that both anti-HCV and HBsAg were risk factors for HCC. The population-attributable risk was estimated as 14.2% for anti-HCV alone, 59.4% for HBsAg alone and 8.0% for both anti-HCV and HBsAg in Taiwan. In conclusion, both hepatitis B and C virus infection are independent risk factors for HCC in Chinese in southern Taiwan.

Aged↗

Effects of hepatitis C and B viruses infection on the development of hepatocellular carcinoma.

A case control study consisting of 102 patients with HCC, 102 sex-matched and age-matched patients with nonhepatic disease, and 204 matched healthy controls was carried out to investigate the effect of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection on the development of hepatocellular carcinoma (HCC). The prevalence of antibody to HCV (anti-HCV) in HCC (34.3%) was higher than in nonhepatic disease (10.7%, P < 0.001) or in healthy controls (2.4%, P < 0.001). The prevalence of hepatitis B surface antigen (HBsAg) in HCC (77.4%) was higher than in nonhepatic disease (16.6%, P < 0.001) or in healthy controls (19.6%, P < 0.001). Anti-HCV positivity in nonhepatic disease was higher than in healthy controls (P < 0.01). Using patients with nonhepatic disease as controls, stepwise logistic regression analysis indicated that both anti-HCV (odds ratio, 3.4; 95% confidence interval, 2.1-5.6) and HBsAg (odds ratio, 5.6; 95% confidence interval, 3.6-8.5) are independent risk factors for HCC. Using healthy controls, the development of HCC was also strongly associated with anti-HCV (odds ratio, 8.0; 95% confidence interval, 4.3-14.6) and HBsAg (odds ratio, 5.5; 95% confidence interval, 3.7-8.2). Calculation of incremental odds ratio indicated that there is no interaction between HBV and HCV. In conclusion, HBV and HCV are risk factors of HCC. They act independently and without interaction.

Adult↗

Urban-rural and regional differences in infant mortality in Taiwan.

We analyzed data from death certificates for all infant deaths in Taiwan from 1981 to 1988. During this 8-year period, the crude infant mortality rate decreased from 8.9 to 5.3 per 1000 live births. Deaths due to infectious diseases, which constituted a major fraction of this mortality, also declined from 3.4 to 1.2 per 1000 live births. While infant deaths due to nearly all causes declined, deaths due to injury and accidents rose from 0.62 to 0.71 per 1000 live births, and the sudden infant death rate rose from 0.13 to 0.46. Notable geographic differences included a high death rate in the small islands off the coast and in the eastern mountainous counties (9.1-11.2/1000 live births); this rate was twice that in Taipei (4.5/1000 live births). In addition, the level of urbanisation was also an important determinant of death rate; urban areas had much lower rates than rural areas. The highest rate (15.4) was persistently observed in the rural areas where the aboriginal tribes reside. This differential rate between urban and rural areas was most prominent for the vaccine-preventable diseases; the aboriginal areas had rates that were 12.9 times those in the cities. Moreover, since neonatal deaths are severely under-reported in Taiwan, especially in less urbanized areas, our data presumably underestimate the urban-rural health differences. Our findings identify high risk areas for various causes of infant death, and indicate that more targeted intervention such as improving education and health care as well as environmental hygiene in some specific areas may be warranted.

Cause of Death↗

Hepatitis B and C virus infection as risk factors for liver cirrhosis and cirrhotic hepatocellular carcinoma: a case-control study.

To investigate whether hepatitis B virus (HBV) and hepatitis C virus (HCV) infection are risk factors for liver cirrhosis and hepatocellular carcinoma (HCC), a case-control study of 102 cirrhotic HCC patients, 102 sex-matched and age-matched patients with liver cirrhosis, and 102 matched patients with non-hepatic disease controls was performed. The prevalences of hepatitis B surface antigen (HBsAg) and antibody to HCV (anti-HCV) in HCC (70.5%, 39.2%) and liver cirrhosis (74.5%, 27.4%) were higher than controls (16.6%, 10.5%) (P = 0.0001). In HBsAg-negative patients, the prevalence of anti-HCV in cirrhotic HCC (66.6%) and liver cirrhosis (46.1%) was higher than in controls (10.5%; P = 0.0001). There was no such difference in HBsAg-positive patients. Multivariate analysis revealed that both HBsAg and anti-HCV were important risk factors for HCC (odds ratio, 6.52 and 4.59, respectively) and liver cirrhosis (odds ratio, 4.22 and 2.29, respectively). There was no difference in odds ratio when HCC and liver cirrhosis were compared. Our result implies that both HBV and HCV are independent risk factors for cirrhotic HCC and liver cirrhosis in Taiwan.

Carcinoma, Hepatocellular↗

Detection of bovine trichomoniasis with a specific DNA probe and PCR amplification system.

Trichomoniasis is a widespread, economically important venereal disease of cattle which causes infertility and abortion. Effective control of trichomoniasis has been impeded by the insensitivity of traditional diagnostic procedures, which require the isolation and cultivation of the parasite, Tritrichomonas foetus, from infected cattle. We developed a 0.85-kb T. foetus DNA probe by identifying conserved sequences in DNAs from T. foetus that were isolated from cattle in California, Idaho, Nevada, and Costa Rica. The probe hybridized specifically to DNAs of T. foetus isolates from different geographic areas but not to DNA preparations of Trichomonas vaginalis, bovine cells, or a variety of bacteria from cattle. The probe detected DNA from a minimum of 10(5) T. foetus organisms. To improve sensitivity, a partial sequence of the probe was used to identify oligonucleotide primers (TF1 and TF2) which could be used to amplify a 162-bp product from T. foetus DNAs by PCR. A chemiluminescent internal T. foetus sequence probe was hybridized to Southern blots of the amplification product. This system detected as few as one T. foetus organism in culture media or 10 parasites in samples containing bovine preputial smegma. Analysis of 52 clinical samples showed that 47 (90.4%) of the 52 samples were correctly identified, with no false-positive reactions. In comparison, the traditional cultivation method detected 44 (84.6%) of the 52 samples from T. foetus-infected and uninfected bulls. These results indicate that the PCR-based amplification system could be a useful alternative method for the diagnosis of bovine trichomoniasis.

Animals↗

Intrafamilial transmission of hepatitis C virus.

Family members of hepatitis C virus (HCV)-infected hemodialysis patients had a high rate (8.1%) of HCV infection and were often infected by the same genotype of HCV as the renal patients. Renal patients who had a longer history of hemodialysis or more frequent arteriovenous shunt replacement posed a higher risk to their household contacts, especially to their primary-care providers at home.

Adult↗

Parathyroid hypertensive factor and non-insulin-dependent diabetes mellitus.

The recently discovered parathyroid hypertensive factor (PHF) has been shown to increase intracellular free calcium levels. High intracellular calcium can cause insulin resistance, as seen in non-insulin-dependent diabetes mellitus (NIDDM) patients. We therefore compared plasma PHF activity in NIDDM patients and nondiabetic control subjects using a rat bioassay. More NIDDM patients (65%) than non-diabetic controls (33.3%) had detectable PHF activity. When injected into rats, plasma of 185 NIDDM patients caused an average increase of 4.89 +/- 0.68 mm Hg in rat mean arterial pressure (MAP). This change was significantly greater than a slight drop of 0.42 +/- 0.96 mm Hg (mean +/- SE) for the 127 nondiabetic control subjects (Student's t test, p < 0.001). A higher percentage of the NIDDM patients than of the non-diabetic patients were hypertensive. However, a stratified analysis showed that diabetic patients consistently had significantly higher PHF levels than did nondiabetic patients, regardless of being hypertensive or not. PHF activity did not correlate with age, sex, body mass index, or the type of hypoglycemic agent taken. However, multivariate logistic regression analysis showed a positive correlation between cholesterol and PHF level among the diabetic patients (p = 0.03), but such a correlation did not exist among the non-diabetic controls. Our data indicate that elevated PHF may be responsible for insulin resistance in a fraction of NIDDM patients and suggest that PHF may be related to serum cholesterol levels in NIDDM.

Adult↗

Clinical aspects of parathyroid hypertensive factor.

Parathyroid hypertensive factor (PHF) in rats: PHF is an endogenous hypertensive substance which was originally associated with hypertension in spontaneously hypertensive rats (SHR). In this model, PHF was shown to act by increasing intracellular calcium levels in vascular smooth muscle and was linked with a characteristic pattern of abnormalities in overall calcium regulation. The action of PHF was blocked by calcium antagonists, suggesting that the effect of PHF was to increase extracellular calcium uptake. In SHR the parathyroid glands were shown to be the site of PHF secretion. This secretion was inhibited by an increase in dietary calcium. PHF was further shown to be unique to low-renin forms of hypertension, that is, those forms of hypertension characterized by abnormalities in calcium metabolism. PHF in humans: PHF was subsequently found in human low-renin salt-sensitive hypertension. As in SHR, calcium supplementation can lower PHF levels in humans. Similarly, there is circumstantial evidence for the parathyroid origin of PHF in humans. In human hypertensive patients, the presence of PHF has been shown to predict a favorable therapeutic response to calcium channel blockade. Recently, many of the abnormalities in calcium metabolism present in low-renin hypertension have also been described in other disease states. Notable among these diseases is non-insulin dependent diabetes mellitus. A survey of human non-insulin dependent diabetes mellitus has revealed that PHF was present in a disproportionate number of these patients independently of the blood pressure level. The significance of this latter finding needs to be explored, but PHF may prove to have relevance in diseases other than hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Hepatitis C virus infection as a risk factor for non-alcoholic liver cirrhosis in Taiwan.

To assess whether hepatitis C virus infection was a risk factor for the development of non-alcoholic liver cirrhosis, antibody to hepatitis C virus (anti-HCV; detected by a second generation HCV enzyme immunoassay), hepatitis B surface antigen (HBsAg; detected by radioimmunoassay) were tested in 150 cirrhotics and 150 sex-matched and age-matched healthy controls. The prevalence of anti-HCV and HBsAg in cirrhotics was higher than in controls (22.0%, 73.3% vs. 2%, 18.7%; P = 0.001). The prevalence of anti-HCV in HBsAg-negative cirrhotics (45.0%) was higher than that in HBsAg-positive patients (13.6%; P = 0.001). Both the anti-HCV and carriage of HBsAg were associated significantly with liver cirrhosis, showing odds ratio of 12.0 for HBsAg carriers and 13.8 for patients with anti-HCV. Compared with those without HBsAg and anti-HCV, there was a significantly positive linear trend for developing cirrhosis with the presence of HBsAg alone (odds ratio = 19.9), anti-HCV alone (odds ratio = 49.0), and those positive for HBsAg and anti-HCV (odds ratio = 81.8) (P = 0.00001). The population-attributable risk for developing liver cirrhosis was estimated as 10.8% for anti-HCV alone, 55.2% for HBsAg alone, and 9.4% for both anti-HCV and HBsAg in southern Taiwan. In conclusion, this study shows that hepatitis B and C virus infection act independently and synergistically in the development of non-alcoholic liver cirrhosis among Chinese in Taiwan.

Age Factors↗

High rate of concurrent genital infections with human cytomegalovirus and human papillomaviruses in cervical cancer patients.

A case-control study evaluated a possible association between infection with human papillomavirus (HPV) or cytomegalovirus (CMV) and cervical cancer. Seventy-eight patients with cervical cancer (cases) were compared with 55 age-compatible patients with uterine leiomyoma (controls). Genital CMV and HPV infections were diagnosed by polymerase chain reaction amplification of viral DNA in cervical tissues. Smoking, first coitus or pregnancy before age 20, multiple sex partners, history of multiple pregnancies, and frequent sexual intercourse were important factors associated with cervical cancer. Only 9% of the cases versus 29.1% of the controls did not have genital infection with either virus. Concurrent genital CMV and HPV infection was noted in 51.3% of the cases but in none of the controls. HPV infection alone occurred in 15.4% of the cases but in only 5.5% of the controls. CMV infection alone was associated with no increased risk for cervical cancer. These data suggest that a synergistic interaction may occur between these two viral infections in the oncogenesis of cervical cancer.

Adult↗

Hepatitis C markers in hemodialysis patients.

The prevalence of hepatitis C virus (HCV) infection among the patients of a hemodialysis unit in Taiwan was determined by an immunoblot and reverse transcriptase-polymerase chain reaction algorithm to be 58.8% (67 of 114 patients) after serological surveys with two advanced-generation enzyme-linked immunosorbent assays (ELISAs) for anti-HCV and a C 100-3 single-antigen test. The results of the second-generation ELISAs, the supplementary immunoblot test, and the test for HCV RNA were in good agreement with each other, from 86.0 to 98.2%. The first-generation C 100-3 test lacked the sensitivity of the four other systems. The two advanced-generation screening ELISAs for anti-HCV, a multiple-recombinant-antigen test, the Abbott second-generation ELISA, and a synthetic peptide multiple-antigen test, the UBI HCV EIA, provided reliable and virtually equivalent detection of potentially infected blood. Antibodies to capsid 1 and capsid 2 determinants of the Liatek immunoblot system were the most frequently detected reactivities to HCV in the HCV-infected hemodialysis patients. The percentage of HCV-infected patients with abnormal liver function (alanine aminotransferase level, greater than 100 IU/liter) was higher than that of the uninfected patients. The prevalence of HCV infection was correlated to the duration of hemodialysis treatment and the amount of blood transfused, and the most common transmission mode was thought to be patient-to-patient transmission through the dialysis equipment. Several means of reducing the frequency of transmission between hemodialysis patients are suggested.

Adult↗

Tattooing as a risk of hepatitis C virus infection.

The association of hepatitis C virus (HCV) infection and tattooing was studied in 87 tattooed and 126 tattoo free healthy young men who did not engage in intravenous drug use or multiple sexual activity. Antibody against HCV (anti-HCV) was tested in serum specimens by enzyme immunoassay with C100-3, NS3, and core antigens; 11 of the 87 (12.6%) tattooed and 3 of the 126 (2.4%) tattoo free subjects were positive for anti-HCV (odds ratio = 5.9, 95% CI = 1.6-22.0). A relationship was demonstrated by an increased risk for HCV infection with an increasing number of tattooed site (P(trend) = 0.002). All but one of the 87 tattooed subjects had been infected by hepatitis B virus (HBV) and 25 were carriers of hepatitis B surface antigen (HBsAg). None of the 25 HBsAg carriers was positive for anti-HCV whereas 11 of the 62 HBsAg non-carriers had anti-HCV, suggesting a negative association between the HBsAg carriage and the long lasting anti-HCV (P = 0.02, Fisher's exact). The status of the tattooer was also an important determinant for HCV infection; the risk was higher if tattooing was done by a non-professional friend than by a professional tattooist. Tattooing, probably with improperly sterilized needles, can clearly pose an increased risk for HCV infection in Taiwan. This study indicates the need for legal standards for hygienic tattooing as part of preventive measures for the control of parenterally transmitted infections.

Adolescent↗

Seroepidemiology and evaluation of passive surveillance during 1988-1989 measles outbreak in Taiwan.

A seroepidemiological study was carried out to explore the risk factors of a measles outbreak that occurred among school children at a rural village (Li-Tse) in Taiwan. Among the 1166 participants, the percentage susceptible before the outbreak was 10.5% (122/1158) which was estimated as the sum of measles IgG-negative (29/1158) and IgM-positive (93/1166) individuals. Among 340 vaccinated children, 16 (4.7%) were measles IgM-positive and 10 (2.9%) were measles IgG-negative; therefore the vaccine failure rate was estimated to be 7.6% (26/340) and vaccine efficacy was 79.7% (95% confidence interval [CI] : 65.0-88.5). The most important risk factors for acquiring measles infection were the presence of other measles cases in the family (Odds Ratio [OR] = 32.5, P = 0.002) and the presence of more than two cases in a class (OR = 29.1, P = 0.003). The physician reporting rate was 6.1% (4/66), and the sensitivity of passive measles surveillance was only 4.3% (4/93) by active serosurvey. A concomitant rubella epidemic also amplified the inaccuracy of a passive reporting system based only on clinical diagnosis. Five children developed measles IgM but did not experience any symptoms, indicating that asymptomatic measles infection can occur. Our experience has highlighted three important areas for future measles elimination: (1) the need for serological evaluation of vaccinees, particularly those who were born during the introduction of mass immunization; (2) improvement in measles vaccine efficacy; and (3) further investigations on the role of asymptomatic transmission and susceptibles who remain after mass immunization.

Adolescent↗