Comparison of three different hybridization assays in the quantitative measurement of serum hepatitis B virus DNA

The measurement of hepatitis B virus (HBV) DNA, is important for monitoring and evaluating the efficacy of anti-viral agents in the treatment of patients with chronic hepatitis B. Three different hybridization assays for quantitative measurement of HBV DNA: direct membrane (dot-blot) hybridization, liquid hybridization (Abbott HBV DNA assay) and branched DNA signal amplification assay (Quantiplex, Chiron), were applied to 114 serial serum samples obtained from 13 patients with chronic active hepatitis B who had received ribavirin 600 mg daily for four weeks. Among the three assays, the correlation was found to be highest between Quantiplex and Abbott HBV DNA assay (r = 0.71, p < 0.01), moderate between Quantiplex and dot-blot hybridization (r = 0.58, p < 0.01) and lowest between dot-blot hybridization and Abbott HBV DNA assay (r = 0.27, p < 0.01). Quantiplex detected 107 (94%) of 114 specimens and was the most sensitive assay. All specimens positive by dot-blot hybridization and Abbott HBV DNA assays were detected positive by Quantiplex. The Dot-blot hybridization assay detected all 89 (100%) specimens with a high HBV DNA level (> or = 10 million genome equivalent (Meq)/ml by Quantiplex), but detected only 7 (50%) of 14 specimens with a low HBV DNA level (< 10 Meq/ml). The Abbott HBV DNA assay detected 85 (95%) of 89 specimens with a high HBV DNA level, but detected only 3 (17%) of 18 specimens with a low HBV DNA level. Among 7 negative specimens in the Quantiplex assay, 2 were detected positive by polymerase chain reaction. In conclusion, Quantiplex assay was more sensitive than Abbott HBV DNA assay and dot-blot hybridization assay for quantitative measurement of serum HBV DNA and can be used in the evaluation of the therapeutic drug effect on chronic hepatitis B patients.

Modification of cardiovascular response of adenosine A1 receptor agonist by cyclic AMP in the spinal cord of the rats

This study was performed to investigate the influence of the spinal adenosine A1 receptors on the central regulation of blood pressure (BP) and heart rate (HR), and to define whether its mechanism is mediated by cyclic AMP (cAMP) or cyclic GMP (cGMP). Intrathecal (i.t.) administration of drugs at the thoracic level were performed in anesthetized, artificially ventilated male Sprague-Dawley rats. Injection (i.t.) of adenosine A1 receptor agonist, N6-cyclohexyladenosine (CHA; 1, 5 and 10 nmol) produced dose dependent decrease of BP and HR. Pretreatment with a cAMP analogue, 8-bromo-cAMP, attenuated the depressor and bradycardiac effects of CHA (10 nmol), but not with cGMP analogue, 8-bromo-cGMP. These results suggest that adenosine A1 receptor in the spinal cord plays an inhibitory role in the central cardiovascular regulation and that this depressor and bradycardiac actions are mediated by cAMP.

Risk factor analysis of patients with chronic hepatitis C in Taiwan

BACKGROUND

Parenteral transmission is the major route for hepatitis C virus (HCV) infection. However, in western countries, 40% of patients with chronic hepatitis C have no apparent risk factor of HCV infection. This study was designed to investigate the possible risk factors of HCV transmission in chronic hepatitis C patients in Taiwan.

METHODS

One hundred and sixty-one consecutive patients with chronic hepatitis C and 161 age- and sex-matched healthy subjects were enrolled. Risk factors, including blood transfusion, injection with nondisposable needles, education status, surgery, dental procedure, tattooing, ear-piercing, sexual behavior and alcoholism, were obtained in every patient through questionnairing and interviewing.

RESULTS

Patients with chronic hepatitis C, compared with healthy controls, had significantly higher rates of previous history of blood transfusion, frequent nondisposable needle injections, and lower education status (43.5% vs. 10.6%, 19.9% vs. 6.2%, 42.2% vs. 23.0%, respectively, all p < 0.05). Univariate logistic regression analysis showed blood transfusion, frequent nondisposable needle injections and low education as significant risk factors of HCV infection (all p < 0.05). Multivariate analysis again revealed them all to be independent significant risk factors associated with HCV infection in chronic hepatitis C patients.

CONCLUSIONS

Parenteral transmission of HCV via transfusion and frequent nondisposable needle injections were the main routes of contracting HCV infection in patients with chronic hepatitis C in Taiwan. Also, people with low education ran the higher risk of transmission by HCV. Meticulous screening of the transfused blood for HCV, usage of disposable needles, and mass public education are important in our efforts to decrease chronic HCV infection in Taiwan.

Evaluation of hepatitis B and C viral markers: clinical significance in Asian and Caucasian patients with hepatocellular carcinoma in the United States of America

In order to evaluate the roles of hepatitis B virus (HBV) and hepatitis C virus (HCV) and their clinical significance in Asian-American and Caucasian patients with hepatocellular carcinoma (HCC) in the USA, 110 HCC patients, seen in a community-based teaching hospital in the Los Angeles area over a 10 year period, were enrolled. Seventy-nine (72%) patients were Asian-American and 31 (28%) were Caucasians. Of the 110 HCC patients, 69 (63%) were positive for serum hepatitis B surface antigen (HBsAg), 26 (24%) were positive for serum antibody to hepatitis C virus (anti-HCV), five (all Asian-Americans) were positive for both markers; 11 (10%) patients had a history of alcoholism. HBsAg was detected in 63 (80%) Asian-American patients, significantly higher than in the six (19%) Caucasian HCC patients (P < 0.01). Anti-HCV was detected in 10 (32%) Caucasian and in 16 (20%) Asian-American HCC patients (P > 0.05). Among Asian-American HCC patients, anti-HCV was more prevalent in those who were HBsAg-negative than in the HBsAg-positive patients (69 vs 8%; P < 0.01). A history of alcoholism was obtained in nine (29%) Caucasian HCC patients, significantly higher than in the two (3%) Asian-American HCC patients (P < 0.05). Comparing HCC patients with positive HBsAg and with anti-HCV, HBsAg-positive HCC patients were younger, Asian-Americans and predominantly male; 38% had a family history of liver disease. In contrast, anti-HCV-positive HCC patients were older by nearly a decade and 46% had a history of blood transfusion. Using a stepwise logistic regression analysis, Asian race and patient age < 50 years were found to be independent predictors for HBsAg-positivity, while a history of blood transfusion was the only predictor for anti-HCV-positivity in HCC patients. There was no significant difference in the rate of cirrhosis, serum levels of alpha-fetoprotein and survival between HBsAg-positive and anti-HCV-positive HCC patients. In conclusion, chronic HBV infection was the major aetiological factor in Asian-American HCC patients, while chronic HCV infection and alcoholism were major aetiological factors in Caucasian HCC patients in the USA.

Prognostic factor analysis of fulminant and subfulminant hepatic failure in an area endemic for hepatitis B

In order to determine the criteria in selecting candidates for orthotopic liver transplantation (OLT), we assessed the aetiology and prognostic indicators in 61 patients with fulminant or subfulminant hepatitis during the past 13 years. Several previously reported models of high risk predictors were not suitable for a large portion of our patients with different aetiological and ethnic backgrounds. In the present study, serological markers of various hepatitis viruses were tested and clinical parameters were compared between survivors and non-survivors. Multiple virus infection and multifactorial causes were important in the pathogenesis (48%) of acute liver failure. Among the 13 clinical parameters, six were considered significant on univariate analysis: prothrombin time prolongation (P < 0.001), total bilirubin, creatinine and alpha-fetoprotein (P < 0.01), age and cholesterol (P < 0.05). With stepwise logistic regression using most discriminatory cut-off values, an age of > 43 years (P = 0.0001), total bilirubin levels of > 23 mg/dL (P < 0.005) and prothrombin time prolongation > 19 s (P < 0.0001) were independent predictors of non-survival. When applied to determine the index of poor prognosis, the sensitivity, specificity, positive predictive value, negative predictive value and predictive accuracy were 100, 67, 95, 100 and 95%, respectively, in the presence of any one of these prognostic factors. We conclude that these indicators may be useful for selecting patients with acute liver failure indicated for OLT.

Hyperglucagonaemia in cirrhotic patients and its relationship to the severity of cirrhosis and haemodynamic values

Plasma glucagon concentrations were measured in 160 cirrhotic patients (Pugh's grade A in 52 patients, Pugh's grade B in 64 patients and Pugh's grade C in 44 patients). These values were compared with plasma glucagon concentrations in 57 age and sex-matched healthy subjects. Systemic and portal haemodynamic measurements, effective renal plasma flow and creatinine clearance were recorded for each patient. Plasma glucagon levels were significantly increased in cirrhotic patients compared with healthy subjects. In addition, plasma glucagon levels were higher in cirrhotic patients with ascites than in those without ascites and were increased in relation to the severity of cirrhosis as assessed by Pugh's score. Multiple linear regression found that only Child-Pugh's score was estimated to be an independent predictor of hyperglucagonaemia in cirrhotic patients. However, in patients with different degrees of oesophageal varices and in patients without oesophageal varices, plasma glucagon concentrations were no different among the different groups of patients, but were still higher than plasma glucagon concentrations in healthy subjects. In contrast, plasma glucagon levels were negatively correlated with mean arterial pressure and systemic vascular resistance. The results of the present study suggest that impairment of liver function plays, in part, a role in increased plasma glucagon levels observed in patients with cirrhosis. In addition, these data support the hypothesis that hyperglucagonaemia may contribute, at least in part, to the pathogenesis of peripheral arterial vasodilatation in cirrhosis with portal hypertension.

Prenatal and postnatal changes of the human tonsillar crypt epithelium

The tonsillar crypt shows infiltration of lymphoid cells in the epithelium and the highly porous or discontinuous basement membrane. However, the relationship between developmental period and the significance of the disrupted epithelial basement membrane and infiltration of lymphoid cells within the human tonsillar crypt epithelium is still obscure. The present study was designed to determine the prenatal and postnatal changes of the human tonsillar crypt epithelium in 4 fetuses, 4 neonates, 1 infant, 5 children and 4 adults using immunohistochemical stains with polyclonal anti-laminin and monoclonal anti-type IV collagen antibody, and transmission electron microscope. The tonsillar crypt epithelium from all fetuses and neonates showed infiltration of many lymphoid cells and an intact basement membrane by immunohistochemistry. Transmission electron microscope revealed pores in the basement membrane through which lymphocytes passed. Tonsils from a 4-month-old infant showed focal disruption of the basement membrane by immunohistochemical staining. The tonsils from children and adults showed that there was massive disruption of the basement membrane with lymphoid cell infiltration in the tonsillar crypt epithelium by immunohistochemical staining and transmission electron microscopy. In conclusion, lymphoid cell infiltration and holes of the basement membrane of the tonsillar crypt epithelium are normal developmental findings, whereas disruption of the basement membrane of the tonsillar crypt epithelium is pathological.

Prevalence of gastric ulcer in cirrhotic patients and its relation to portal hypertension

The prevalence of gastric ulcer and its relationship to the severity of cirrhosis and degree of portal hypertension was evaluated in 245 cirrhotic patients, and compared with 245 age- and sex-matched healthy subjects. Portal and systemic haemodynamic studies were performed in cirrhotic patients. The prevalence of gastric ulcer in cirrhotic patients was 20.8%, which was significantly higher than the 4.0% found in healthy controls. Using a multivariate logistic regression model, the hepatic venous pressure gradient was found to be the only predictor of the prevalence of gastric ulcer in cirrhotic patients to present with gastric ulcer. The hepatic venous pressure gradient was significantly higher in cirrhotic patients with gastric ulcer than in those without (17.3 +/- 4.4 vs 15.5 +/- 5.0 mmHg, P = 0.01). Other variables, including sex, smoking, cardiac output and severity or aetiology of cirrhosis did not show significant differences between the two patient groups. The prevalence of gastric ulcer in cirrhotic patients whose hepatic venous pressure gradient was below 12 mmHg (4.5%) was similar to that observed in the healthy controls (4.0%). However, when the hepatic venous pressure gradient was > 12 mmHg, the prevalence of gastric ulcer (24.4%) was significantly higher than that in control subjects. However, the incidence of gastric ulcer was not related to the degree of portal hypertension. In conclusion, the prevalence of gastric ulcer in cirrhotic patients was found to be significantly higher than in the age- and sex-matched healthy subjects. Portal hypertension with a hepatic venous pressure gradient > 12 mmHg may be an important factor contributing to the increased prevalence of gastric ulcer observed in patients with liver cirrhosis.

Behavioral changes with alterations of choline acetyltransferase immunoreactivities induced by N-butyl benzenesulfonamide

N-butyl benzenesulfonamide (NBBS), one of the sulfonamide plasticizers, induced characteristic effects to Wistar rats after acute repeated exposures (300 mg/kg body weight, ip every 6 h). The signs were pica, staggering gait with hindlimb-paresis and splaying, teeth-grinding, self paw-biting and coma. The motor activity parameters showed generalized decreased mobility. The gait and hindlimb abnormalities coexisted with changes of lower motoneuron activity, ie decreased immunoreactivity of choline acetyltransferase in the lumbar spinal cord. The effects became more overt with repeated exposure to NBBS and the severity was increased. These effects were short-lived and the animals soon recovered.

Efficacy of ursodeoxycholic acid in the treatment of patients with chronic hepatitis C

A case-control study was conducted to evaluate the efficacy of ursodeoxycholic acid (UDCA) in the treatment of Chinese patients with chronic hepatitis C. Patients who failed to have sustained responses to interferon (IFN) therapy, refused to take IFN or were unsuitable for IFN treatment were enrolled into this study. The treatment group had 15 patients and they received UDCA 600 mg orally per day for 6 months. Another 15 patients with matched sex, age and initial serum alanine aminotransferase (ALT) levels were chosen as the control group. Three parameters (i.e. serum ALT levels, serum hepatitis C virus (HCV) RNA and serum cytokines) were measured before and after UDCA treatment. After the treatment period, the mean serum ALT levels in both groups were not significantly different (153.8 +/- 111.0 U/L vs 112.1 +/- 53.8 U/L, P > 0.05) and mean serum ALT level in the UDCA-treated group did not decrease after the treatment (pre-treatment vs post-treatment value: 139.1 +/- 73.1 U/L vs 153.8 +/- 111.0 U/L, P > 0.05). In addition, all of the patients with positive HCV RNA before treatment still had active HCV viraemia after the UDCA treatment. Also, the serum levels of interleukin-6 (IL-6) and the tumour necrosis factor-alpha (TNF-alpha) were not significantly different between the two groups before and after the treatment period. In conclusion, a regimen of UDCA as prescribed in the present study did not show obvious benefits in the treatment of Chinese patients with chronic hepatitis C.

Randomized controlled trial of recombinant interferon-alpha 2b in the treatment of Chinese patients with chronic hepatitis C

To evaluate the efficacy of recombinant interferon (IFN) alpha 2b in the treatment of Chinese patients with chronic hepatitis C, a randomized controlled trial was conducted in 50 chronic hepatitis C patients: 25 patients received 3 million units of subcutaneously injected recombinant IFN-alpha 2b three times per week for 6 months, and 25 patients received no specific treatment were used as controls. At the end of the IFN treatment, 19 patients (76%) in the IFN-treated group normalized serum ALT compared with only 6 patients (24%) in the control group (p < 0.01). Relapse within 6 months after the completion of treatment occurred in 13 IFN-treated patients (68%). Normalized serum ALT was seen in 6 patients (24%) in the IFN-treated group and 1 patient (4%) in the control group 6 months after discontinuation of IFN therapy (p = 0.10). The presence of serum hepatitis C virus (HCV) RNA measured by reverse transcription-polymerase chain reaction was detected at the end of the IFN treatment in all 13 patients who relapsed after cessation of therapy. In only 3 of 25 IFN-treated patients (12%) was the presence of serum HCV RNA not detectable at the end of the IFN treatment or 6 months after cessation of therapy. No patient in the control group had undetectable serum HCV RNA during the study period. Using multivariate logistic regression analysis, the low pretreatment levels of HCV RNA, measured by a quantitative branched DNA amplification assay, was the only independent predictor of a sustained response to IFN therapy (p = 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Injection with nondisposable needles as an important route for transmission of acute community-acquired hepatitis C virus infection in Taiwan

A prospective case-controlled study was conducted in order to determine the transmission route of community-acquired hepatitis C virus (HCV) infection in Taiwan. Thirty-eight consecutive patients (25 men and 13 women) with acute community-acquired HCV infection and 76 age (within 3 years)- and sex-matched healthy control subjects without HCV infection were enrolled. Serum anti-HCV was tested by second generation immunoassay. The sera of 26 family members from 12 families of index patients were also tested for anti-HCV. A questionnaire covering the history of blood transfusion, surgery, intravenous drug abuse, prostitute contact, dental procedures, injection, acupuncture, tattooing, and ear-piercing was conducted among patients and control subjects. Univariate analysis revealed injection with nondisposable needles was an independent risk factor (P = 0.02, odds ratio = 4.17, 95% confidence interval = 1.24-14.47) associated with HCV infection. Other risk factors were not significant. Only 2 (7.7%) family members of index patients had an anti-HCV. In conclusion, more vigorous effort to prohibit the use of nondisposable needles should be promoted to interrupt the spread of community-acquired HCV infection in Taiwan. Of note, a significant number of patients (34.2%) contracted HCV infection without identifiable risk factors. Unidentified routes need to be investigated.

Technetium-99m albumin scintigraphy in the diagnosis of protein-losing enteropathy: a case report

A 34-year-old female presenting with bilateral lower leg edema and distended abdomen was admitted to our hospital. The serum albumin was 1.42g/dl. Renal function and hepatic function were normal. Urinalysis did not show proteinuria. Tc-99m albumin scintigraphy was arranged for this patient to rule out protein-losing enteropathy. The results demonstrated loss of albumin into the intestines. We conclude that Tc-99m albumin scintigraphy of the abdomen is a valuable adjunct in the diagnosis of protein-losing enteropathy.

[Swallowing of fixed denture following general anesthesia--a case report]

Dental injury is a common complication associated with endotracheal general anesthesia. According to a study in Japan, the incidence of dental injury caused by endotracheal intubation is 0.69%. In one study in our country, evaluation of the oral condition was performed before, during and after anesthesia, and the frequency of dental trauma is as high as 12.1%. Fragment(s) of tooth or denture may cause serious, or even fatal complications. We report a case of swallowing of fixed denture following endotracheal general anesthesia. Our accident involved a 33-yr-old male who had experienced bilateral auditory impairment as a result of chronic otitis media. The patient underwent right modified radical mastoidectomy under endotracheal general anesthesia. It might well be that the patient's maxillary fixed denture was loosened at the time of endotracheal intubation. However, patient's denture was normal in appearance and not much attention was paid to it. During his stay at the post-anesthesia care unit, he might have unconsciously swallowed his denture. Verification was later made by X-ray. On careful observation, his denture was found in the feces during defecation 30 h post-operatively.

A pilot, open-labelled, phase II study using oral ribavirin in the treatment of patients with chronic active hepatitis B

BACKGROUND

Ribavirin is a synthetic purine nucleoside with demonstrated antiviral activity against several DNA and RNA viruses.

OBJECTIVES

An open-labelled pilot study to evaluate the safety and effect of ribavirin in the treatment of patients with chronic active hepatitis B (CAH-B).

STUDY DESIGN

24 CAH-B patients were treated with oral ribavirin 1200 mg daily in 3 divided doses for 4 weeks. Biochemical and virological parameters were monitored at regular interval during and after treatment.

RESULTS

The serum hepatitis B e antigen (HBeAg) and HBV DNA measured by dot-blot hybridization were positive in all patients before treatment. At the end of 4 weeks of therapy, the HBV DNA levels decreased in 15 (63%) patients and became undetectable in 1 (4%) of these individuals. The mean HBV DNA decreased from 288+/-78 pg/ml at baseline to 219+/-79 pg/ml at the end of the 4 weeks of treatment (p = 0.046). Eight weeks after cessation of treatment, HBV DNA was undetectable in 10 (42%) patients, and the mean HBV DNA was 46+/-23 pg/ml (p < 0.01 when compared to mean baseline value). Seven (29%) patients seroconverted from HBeAg positive to anti-HBe positive but no patients lost hepatitis B surface antigen (HBsAg) during the 8 weeks of follow-up. At the end of 4 weeks of ribavirin treatment, serum levels of alanine aminotransferase (ALT) decreased in all but 1 patient; only 1 patient normalized serum ALT at this time. The mean serum ALT decreased significantly from 416+/-72 IU/l at baseline to 179+/-35 IU/l at the end of 4 weeks of treatment (p = 0.001). Eight weeks after cessation of therapy, the mean serum ALT value was 151+/-32 IU/l (p < 0.001 when compared to mean baseline value) and 5 (21%) patients normalized serum ALT at this time. During ribavirin treatment, the main side effect was a decrease in the hemoglobin level which returned to the pretreatment level in each instance within 2 months after discontinuance of therapy.

CONCLUSIONS

Results of this pilot study indicated that oral ribavirin was well tolerated in CAH-B patients and resulted in lowering of serum ALT and HBV DNA values. A randomized controlled trial is needed to fully evaluate the beneficial effects of ribavirin in CAH-B patients.

Budd-Chiari syndrome due to pacemaker-induced thrombosis

We report a unique case of Budd-Chiari syndrome caused by pacemaker leads-induced thrombosis. A 34 year old female patient was subjected to a permanent pacemaker insertion because of refractory paroxysmal supraventricular tachycardia attacks related to Wolff-Parkinson-White syndrome. Three years later, another pacemaker was re-implanted because of its dislodgement. Four episodes of skin infections at the implantation site were noted thereafter. The patient developed symptoms of abdominal pain and ascites 5 years after the second pacemaker implantation. Ultrasonography and computerized tomography of the abdomen revealed hepatomegaly with ascites and dilated inferior vena cava. An echocardiogram displayed thrombus formation in the superior vena cava, the right atrium and the inlet of the inferior vena cava into the right atrium. Inferior and superior venacavogram confirmed the above findings. With the impression that Budd-Chiari syndrome was caused by pacemaker-induced thrombus, we removed the pacemaker first and thoracotomy with thrombectomy was then performed. The clinical symptoms resolved after the operation. To our knowledge, this is the first case reported in the literature and this observation supported the thrombosis theory for membranous obstruction of inferior vena cava.

Pharmacokinetics of methotrexate after intravenous and intramuscular injection of methotrexate-bearing positively charged liposomes to rats

The pharmacokinetics and tissue distribution of methotrexate (MTX) were investigated after intravenous (IV) and intramuscular (IM) injection of free MTX (treatment I), freshly prepared MTX-bearing positively charged liposomes (large unilamellar vesicles), PLUVs (treatment II), and empty PLUVs mixed manually with free MTX (treatment III), 4 mg kg-1 as free MTX to rats, using HPLC assay. After 1 min IV infusion, the plasma concentrations of MTX (Cp), the area under the plasma concentration-time curve (AUC, 173 against 314 micrograms mL min-1), the terminal half-life (t1/2, 24.0 against 412 min), the mean residence time (MRT, 13.0 against 324 min), and the apparent volume of distribution at steady state (VSS, 289 against 3370 mL kg-1) were significantly larger, but the total body clearance (CL, 23.1 against 12.8 mL min-1 kg-1), the renal clearance (CLR, 8.38 against 3.09 mL min-1 kg-1), the non-renal clearance (CLNR, 14.6 against 9.56 mL min-1 kg-1), and the amount of MTX excreted in urine (Xu, 415 against 275 micrograms) were significantly lower in treatment II than in treatment I. This could be due to the fact that some of the MTX-bearing PLUVs were entrapped in tissues and the rest were present in plasma (larger MRT and Vss in treatment II), and MTX is slowly released from MTX-bearing PLUVs (longer t1/2 in treatment II). In the present HPLC assay, the concentrations of MTX represent the sum of free MTX and MTX in MTX-bearing PLUVs (larger Cp and AUC and slower CL in treatment II). Saturable formation of 7-hydroxymethotrexate from MTX was reported in rabbit blood and nonlinear disposition of MTX was also reported in rats and rabbits (lower Xu and CLR in treatment II). After 1 min IV infusion, some pharmacokinetic parameters of MTX, such as AUC, CL, CLR, CLNR, and Xu, were significantly different between treatments I and III, but nonetheless the differences were smaller than those between treatments I and II. After both IV and IM administration, the amount of MTX remaining per gram of tissue or organ in the kidney, stomach, small intestine, and large intestine was significantly smaller in treatment II than in treatment I.(ABSTRACT TRUNCATED AT 400 WORDS)

Detection of genotype-environment interaction in case-control studies of birth defects: how big a sample size?

Detecting interactions between risk factors in case-control studies of birth defects and other conditions usually requires increasing the sample size beyond that needed to detect marginal effects. A special case of such interaction is genotype-environment interaction in which the effects of an exposure on disease risk are modified by genetic susceptibility. When case-control studies are designed to detect marginal effects of an exposure (i.e., in the whole population), under many plausible interaction schemes, no additional case and control subjects are needed to detect genotype-environment interaction. On the contrary, inclusion of genotypic information generally can improve the statistical power of the original study. Using the example of oral clefts, maternal cigarette smoking, and genetic variation at the transforming growth factor alpha gene, we illustrate sample size and power issues in designing case-control studies when prior information is available on both the marginal effects of the exposure and the genetic factor.

Membranous obstruction of inferior vena cava in Taiwan

Membranous obstruction of the inferior vena cava (MOVC) is a rare cause of Budd-Chiari syndrome. When compared to the West, the incidence of MOVC was reported to be higher in the Orient, India and South Africa. From 1979 to 1993, 16 consecutive Chinese patients (mean age 50 years) with MOVC were retrospectively evaluated. The diagnosis in these MOVC patients was usually delayed with a mean lag time of 111 months. Most of the cases were detected by a delicate ultrasonographic examination of the abdomen. Segmental narrowing of the inferior vena cava in 11 patients was the predominant type of MOVC, while five experienced a membranous obstructive type. Only one of five surgery-treated patients had a post-operation survival > 5 years, while five out of the nine patients who received conservative treatment still survived after a 6-15 year follow up. Two patients received percutaneous angioplasty (PTA). One survived 4 years and the other expired 5 years after the PTA. Two patients (12%) developed a hepatocellular carcinoma in their disease course, and the incidence was lower than in previous reports from Japan and South Africa. The incidence of hepatitis B surface antigen in MOVC did not increase in our patients compared with the general population. In conclusion, the inferior vena cava should be carefully evaluated in an ultrasonographic examination of the abdomen to increase the diagnosis rate of MOVC. Surgical intervention should be carefully justified according to the patient's symptoms and signs, the types of obstructive lesions and the expertise of the surgeons.

Association study of transforming growth factor alpha (TGF alpha) TaqI polymorphism and oral clefts: indication of gene-environment interaction in a population-based sample of infants with birth defects

In this study of infants with isolated birth defects, 69 cleft palate only cases, 114 cleft lip with or without cleft palate cases, and 284 controls with noncleft birth defects (all born in Maryland between 1984 and 1992) were examined to test for associations among maternal exposures, genetic markers, and oral clefts. A significantly higher frequency of positive family history of birth defects among both groups of oral cleft cases compared with controls was seen in these data. While there was a modest increase in the less common C2 allele at the TaqI site in the transforming growth factor alpha (TGF alpha) locus among cleft palate only infants compared with the birth defect controls, the association appeared to reflect an underlying interaction between maternal smoking and infant genotype. This apparent gene-environment interaction was also found among those reporting no family history of any birth defect. Infants carrying the rarer C2 allele who were exposed to maternal smoking of 10 or fewer cigarettes per day showed a 6.16-fold increase in risk for cleft palate only (95% confidence interval 1.09-34.7), while similar infants whose mothers smoked more than 10 cigarettes per day showed an 8.69-fold higher risk (95% confidence interval 1.57-47.8). However, the dose-response relation was not significant.

Detection of antibody to M2 mitochondrial antigen in Chinese patients with primary biliary cirrhosis

BACKGROUND

Antimitochondrial antibodies (AMA) are present in more than 90% of patients with primary biliary cirrhosis (PBC). However, AMA are not specific for PBC; they can be observed in nonhepatic disease. It has been reported that antibody of M2 mitochondrial antigen (anti-M2) is specific for PBC. The aim of the present study is to clarify the role of anti-M2 in the diagnosis of PBC.

METHODS

Sera from 27 patients with PBC, 62 normal subjects, 18 patients with chronic hepatitis B and 30 patients with chronic hepatitis C were obtained for the detection of anti-M2 and AMA. The anti-M2 assay was performed by enzyme immunoassay (EIA) and the AMA test was performed by indirect immunofluorescent method.

RESULTS

Twenty-four (88.9%) of the serum specimens from the patients with PBC and one (0.9%) of the 110 serum specimens from the non-PBC groups were positive for AMA. In contrast, twenty-five (92.6%) of the 27 PBC sera and five (4.5%) of the 110 non-PBC sera were positive for anti-M2. Most of the PBC sera contained high titers of anti-M2 and all the false-negative specimens disclosed low titers of anti-M2.

CONCLUSIONS

Although the anti-M2 assay used in the present study seemed not superior to the conventional AMA test in the sense of specificity, it had the advantage of being able to provide quantitative results. Since the presence of high titer anti-M2 is very specific for PBC, this assay may have a role in the diagnosis of equivocal PBC.

Quantitative branched DNA assay and genotyping for hepatitis C virus RNA in Chinese patients with acute and chronic hepatitis C

To determine the value of a quantitative branched DNA (bDNA) assay for detection of hepatitis C virus (HCV) RNA, 309 serum specimens were collected from 100 patients with acute or chronic hepatitis C for detection of HCV RNA by bDNA assay and reverse transcription-polymerase chain reaction (RT-PCR) assay. There were 256 samples positive by RT-PCR; 199 (78%) were also positive by bDNA assay. All but 1 of the remaining 53 samples negative by RT-PCR were also negative by bDNA assay. Combination of the two methods clearly demonstrated changes in HCV RNA titers during and after interferon (IFN) treatment. The most common genotype of HCV infection was Okamoto type II (Simmonds type 1b, 60.0%), followed by type III (type 2a, 16.5%) and type IV (type 2b, 8.2%); mixed or underdetermined types were noted in 15.3%. Patients with chronic type II HCV infection tended to have higher HCV RNA titers. These findings suggest that the bDNA assay is a reliable test for HCV RNA.

Lack of influence of recombinant human erythropoietin on parathyroid function in hemodialysis patients with secondary hyperparathyroidism

The effects of recombinant human erythropoietin (rHuEPO) treatment on parathyroid function in patients on maintenance hemodialysis (HD) with secondary hyperparathyroidism (HPT) is poorly understood. We compared the levels of serum intact parathyroid hormone (PTH) and the suppressibility of PTH by intravenous calcium infusion before and after 12 weeks of rHuEPO treatment in 8 HD patients with secondary HPT. The suppressibility of PTH by calcium infusion in HD patients was also compared with that of normal subjects. After rHuEPO treatment, in HD patients hematocrit and hemoglobin levels increased significantly from 20.1 +/- 1.3% and 6.65 +/- 0.46 g/dl to 28.7 +/- 1.0% and 9.68 +/- 0.39 g/dl, respectively. The serum intact PTH levels did not change significantly (541.9 +/- 65.3 pg/ml before versus 572.9 +/- 75.3 pg/ml after rHuEPO treatment), nor did serum ionized calcium, phosphate, magnesium, aluminum, alkaline phosphatase, and 1.25(OH)2D levels. Calcium infusion significantly increased serum ionized calcium and suppressed serum PTH levels. However, the increment in serum calcium levels and the percent decrement of serum PTH showed no significant differences before and after rHuEPO treatment in HD patients. Elevations in serum calcium levels during calcium infusions were not significantly different between normal subjects and HD patients. However, the percent maximal decrement in serum PTH level was less in HD patients both before and after rHuEPO treatment than in normal subjects (-75.4 +/- 3.9 and -76.4 +/- 4.1% versus -91.4 +/- 1.4%). We conclude that rHuEPO treatment has no influence on parathyroid function in maintenance HD patients with secondary HPT. In addition, PTH secretion is less suppressed by calcium infusion in the same group of patients.

Evaluation of sexual transmission in patients with chronic hepatitis C infection

BACKGROUND

The transmission of hepatitis C virus (HCV) by parenteral exposure is well documented. However, a proportion of patients with acute or chronic HCV infection have an unknown source of infection.

OBJECTIVES

The purpose of this study is to evaluate the role of sexual transmission in HCV infection.

STUDY DESIGN

68 patients (median age, 50 years) with chronic hepatitis C and their spouses were tested for the presence of antibody to HCV (anti-HCV) by multi-antigen and chimeric C25 antigen enzyme immunoassays and for HCV RNA by the polymerase chain reaction. Information on sexual activity and risk factors for HCV infection were obtained from all couples via a questionnaire.

RESULTS

All index patients were positive for both anti-HCV and HCV RNA. Antibody to HCV was detected in four (5.9%) of their spouses. One anti-HCV-positive spouse had a history of blood transfusion while the other three (4.4%, 95% CI = 1.5-12.2%) had no known risk factors for HCV infection and thus may have been exposed to HCV via sexual transmission. Two of these 3 spouses had positive serum HCV RNA and had identical HCV genotype to the index patients. The length of sexual exposure was significantly longer in the couples who both were anti-HCV-positive than in patients whose spouses were anti-HCV negative (median: 25 vs. 10 years, P = 0.02, Mann-Whitney test). In our 68 index patients, 96% had antibodies to the recombinant proteins from the C22 (core) and C33C (NS3) regions, and 82% and 76% had antibodies to the proteins from the NS5 and C100-3 (NS4) regions. Identical anti-HCV profiles were noted in two of the four anti-HCV-positive couples.

CONCLUSIONS

Our results indicate that sexual transmission, although uncommon, should be considered as a risk factor for HCV infection, especially in spouses who have had long-term intimate relationships with a chronic hepatitis C patient.

Minimum sample size estimation to detect gene-environment interaction in case-control designs

As genetic markers become more available, case-control studies will be increasingly important in defining the role of genetic factors in disease causality. The authors estimate the minimum sample size needed to assure adequate statistical power to detect gene-environment interaction. One assumption is made: the prevalence of exposure is independent of marker genotypes among controls. Given the assumption, six parameters (three odds ratios, the prevalence of exposure, the proportion of those with the susceptible genotype, and the ratio of controls to cases) dictate the expected cell sizes in a 2 x 2 x 2 table contrasting genetic susceptibility, exposure, and disease. The three odds ratios reflect the association between disease and 1) exposure among non-susceptibles; 2) susceptible genotypes among nonexposed individuals; and 3) the gene-environment interaction itself, respectively. Given these parameters, the number of cases and controls needed to assure any particular Type I and Type II error rates can be estimated. Results presented here demonstrate that case-control designs can be used to detect gene-environment interaction when there is both a common exposure and a highly polymorphic marker of susceptibility.

A randomized controlled trial of recombinant interferon alpha-2b in the treatment of Chinese patients with acute post-transfusion hepatitis C

To evaluate the efficacy of recombinant interferon alpha-2b in the treatment of patients with acute post-transfusion hepatitis C, a randomized controlled trial was conducted in 33 acute post-transfusion hepatitis C patients; 16 patients received 3 million units of subcutaneously injected recombinant interferon alpha-2b 3 times a week for 3 months and 17 patients without specific treatment were used as controls. At the end of the interferon treatment, 13 (81%) patients in the interferon-treated group normalized serum alanine aminotransferase compared with only six (35%) patients in the control group (p < 0.01). One year after completion of the interferon treatment, nine (56%) patients in the interferon-treated group and six (38%) patients in the control group normalized serum alanine aminotransferase (p = 0.35). Serum HCV-RNA measured by reverse transcription-polymerase chain reaction was positive in all patients at the time of enrollment and then became undetectable in 13 (81%) patients in the interferon-treated group and two (12%) patients in the control group at the end of interferon treatment (p < 0.001). One year after completion of the interferon treatment, seven (44%) patients in the interferon-treated group and two (13%) patients in the control group had persistent undetectable serum HCV-RNA (p = 0.08). Using a logistic regression model, the lower pretreatment level of serum HCV-RNA measured by quantitative branched DNA signal amplification assay was the only predictor for a favorable response to the interferon treatment in acute hepatitis C patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Correlation of serum HCV RNA and alanine aminotransferase levels in chronic hepatitis C patients during treatment with ribavirin

To evaluate the effect of ribavirin on serum hepatitis C virus (HCV) RNA and alanine aminotransferase (ALT) levels, 22 patients with chronic HCV infection were treated with oral ribavirin 1200 mg daily in three divided doses for 4 weeks. At the end of 4 weeks treatment, the serum ALT decreased in all but one patient and became normal in three individuals. The mean pretreatment serum ALT was reduced significantly from 193 +/- 45 i.u./L to 95 +/- 16 i.u./L after 4 weeks therapy (P = 0.009). However, 8 weeks after cessation of treatment, the serum ALT rose to a mean value of 154 +/- 21 i.u./L. The mean pretreatment serum HCV RNA was not significantly decreased at the end of 4 weeks treatment (7.0 x 10(5) vs. 4.1 x 10(5) copies/mL, P > 0.05). However, serum HCV RNA levels were decreased in 12 and increased in 10 patients at the end of 4 weeks therapy. Eight weeks after cessation of therapy, the serum HCV RNA of 22 patients rose to a mean value of 4.9 +/- 10(5) copies/mL. Six patients who continued to have elevated serum ALT and positive HCV RNA after the initial 4 weeks treatment received oral ribavirin at the same dosage for an additional 24 weeks. The serum ALT again decreased in all six patients during therapy, but rose to pretreatment values by 8 weeks after cessation of the treatment. In addition, no significant changes were noted in the mean serum HCV RNA levels during and after 24 weeks of ribavirin therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Hepatitis B virus infection in Asian Americans

This article summarizes studies on hepatitis B in the Asian American population and includes prevalence rates among different Asian subgroups, routes of transmission, and sequelae of both perinatal and childhood-acquired hepatitis B virus infection. Rationale for use of hepatitis B immune globulin and hepatitis B vaccine for Asian infants and vaccine for children and seronegative adults is discussed also. Chronic hepatitis B, cirrhosis, and primary hepatocellular carcinoma in adults and screening for early detection of liver cancer are reviewed.

Incidence of post-transfusion hepatitis before and after screening for hepatitis C virus antibody

To evaluate the effectiveness of screening test for antibody to hepatitis C virus (anti-HCV), the incidence of acute post-transfusion HCV infection in patients who underwent cardiovascular surgery and received blood transfusion was studied. All patients were followed prospectively with serum biochemistry tests and viral hepatitis markers before and periodically for at least 6 months after cardiovascular surgery. None of them had history of liver disease and none tested positive for anti-HCV prior to blood transfusion. Before blood donors were screened for anti-HCV with a second-generation HCV diagnostic kit, 28 (12.4%) of 226 patients or 0.49% of 5,690 unit transfusion had seroconverted to anti-HCV during a 6-month follow-up. The incidence of post-transfusion hepatitis (PTH) C in 91 patients who had received 1-12 units transfusion was significantly lower than in 135 patients who had received more than 12 units transfusion (6.6 vs. 16.3%, p < 0.05). However, none of the 87 transfused patients, since anti-HCV screening in July 1992, developed PTH C (p < 0.05). The result demonstrates that screening for anti-HCV by a more sensitive second-generation HCV diagnostic assay may protect the patients studied from PTH C. It further provides a firm argument for the necessity of a nation-wide blood donor screening.

Clinical evaluation of erythrocytosis in patients with hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is a common malignancy in southeast Asia and sub-Saharan Africa. During its clinical course, patients may manifest a variety of paraneoplastic syndromes, including erythrocytosis. However, there are few reports on the clinical and biochemical characteristics of HCC patients who manifest erythrocytosis. The purpose of this study is to evaluate the incidence of erythrocytosis in a large series of the Chinese patients with HCC, and to investigate the association of erythrocytosis with tumor volume and with serum levels of alpha-fetoprotein (AFP) and erythropoietin.

METHODS

Among 792 Chinese HCC patients who were seen during a 3-year period, we identified HCC patients with erythrocytosis as those with hemoglobin levels greater than 16.7 gm/dL (two standard deviations above the mean hemoglobin level of matched normal controls). The tumor size and serum levels of AFP and erythropoietin were evaluated in HCC patients with erythrocytosis to compare with HCC patients without erythrocytosis.

RESULTS

20 (2.5%) of 792 Chinese HCC patients presented with erythrocytosis. Nineteen of these 20 HCC patients were found to have either bi-lobar tumor involvement or a large tumor mass confined to one lobe of the liver. The estimated mean tumor volume of HCC patients with erythrocytosis was 50% of whole liver. When compared with HCC patients without erythrocytosis, the 20 HCC patients with high hemoglobin levels had significantly higher serum levels of AFP and erythropoietin (356,343 +/- 145,807 vs. 16,881 +/- 10,425 ng/mL, 135 +/- 45 vs. 25 +/- 4 mU/mL, respectively, p < 0.01).

CONCLUSIONS

Base on our findings, detection of erythrocytosis in a patient with HCC would indicate the presence of a large tumor burden, and high serum levels of both AFP and erythropoietin should be associated with this paraneoplastic syndrome.

Evidence for hepatitis C viral infection in patients with primary hepatocellular carcinoma

In testing for antibodies to the hepatitis C virus (anti-HCV) in 112 patients with primary hepatocellular carcinoma, 10 of 33 white patients (30%) and 15 of 79 Asian patients (19%) had a positive response to the antibody. The antibody profile to individual hepatitis C viral antigens and the presence of circulating hepatitis C viral RNA were determined in the 25 patients. The anti-HCV antibodies most frequently detected were toward the antigens from the core (C22) and NS3 regions. Serum hepatitis C viral RNA was present in 17 of the 25 patients (68%), and these patients tended to have serum levels of alanine and aspartate aminotransferases higher than those patients without viremia (136 +/- 22 U per liter versus 64 +/- 11 U per liter and 161 +/- 26 U per liter versus 79 +/- 14 U per liter, respectively, both P < .05). Of the 15 Asian patients with hepatocellular carcinoma and anti-HCV, 4 (27%) had coexisting hepatitis B surface antigen (HBsAg) and 13 (87%) had antibodies to either hepatitis B core or surface antigen. Of the 10 white patients with anti-HCV, however, only 1 (10%) had hepatitis B virus antibodies (P < .01). Among 4 Asian patients with coexisting anti-HCV and HBsAg, 1 was found to have serum hepatitis B viral DNA and the other 3 had hepatitis C viral RNA. A history of blood transfusion was obtained from 12 of the 25 patients with anti-HCV (48%); 20 (80%) had coexisting cirrhosis. Our findings support the hypothesis that hepatitis C virus is an important etiologic agent in the development of primary hepatocellular carcinoma in both white and Asian patients in the United States.

Hypercalcemia and parathyroid hormone-related protein in hepatocellular carcinoma

A two-site immunoradiometric assay (IRMA) of parathyroid hormone-related protein (PTHrP) was employed to react with circulating concentrations of PTHrP in 14 patients with hepatocellular carcinoma (HCC) and hypercalcemia (> 10.6 mg/dl). Eleven of them had unresectable lesions and three received transcatheter arterial chemo-embolization (TACE) treatment. Patients had no evidence of bony metastases and only one had evidence of a parathyroid lesion (by bone scan and serum parathyroid hormone level, respectively). The urinary cAMP level was increased in all patients, but the serum 1,25-dihydroxyvitamin D and plasma cAMP levels varied. Twelve patients had elevated alpha-fetoprotein (AFP) (> 400 ng/ml) and two of them had mildly elevated AFP levels (11 and 147 ng/ml). Their PTHrP concentrations were elevated (7.1 to 33.2 pmol/l), compared with normal levels obtained in our laboratory (< 3.5 pmol/l). A significant decrease in plasma PTHrP (from 27.4 to 5.2 pmol/l), serum calcium concentrations (from 16.3 to 9.4 mg/dl) and AFP levels (from 64,787 to 3129 ng/ml) was observed on the day following TACE treatment. These results, by using an improved technique, extend the findings that hypercalcemia in patients with HCC is associated with increased renal reabsorption of calcium and increased bone resorption of PTHrP generated by HCC.

Effects of manidipine hydrochloride on blood pressure in hypertensive patients--a comparison with nifedipine retard

Manidipine hydrochloride (MH) is a new calcium channel antagonist which is not yet available in Taiwan. Thus, a clinical trial was performed. The clinical effects and adverse effects of MH were compared with those of nifedipine hydrochloride retard monotherapies. Sixty-three out-patients with mild to moderate hypertension and no advanced systemic diseases were randomly divided into 2 groups. Twenty patients remained in each group after some patients withdrew from the study. Blood pressure decreased significantly after treatment in both groups (p < 0.01). In the manidipine group, systolic blood pressure (SBP) decreased from 164 +/- 14 to 140 +/- 18 mmHg and diastolic BP (DBP) decreased from 99 +/- 6 to 87 +/- 7 mmHg by the 8th week. In the nifedipine group, SBP decreased from 163 +/- 11 to 134 +/- 17 mmHg and DBP decreased from 101 +/- 10 to 88 +/- 9 mmHg by the 8th week. Pulse rates did not change significantly. Antihypertensive efficacy was 18/20 (90%) and 19/22 (86.4%) in the manidipine and nifedipine groups, respectively. There were a few adverse effects in both groups, the reaction was severe as to lead to the discontinuation of medication in two patients in the nifedipine group. No significant changes in laboratory tests were identified in either group, except for minimal decreases of lactate dehydrogenase and creatine kinase in the nifedipine group. We conclude that MH was equally safe and effective as nifedipine and it may have less severe side effects compared to nifedipine.

Hepatitis D virus infection among prostitutes in Taiwan

Two hundred and sixty-three adult licensed, 233 adult and 157 teenage unlicensed prostitutes from Taiwan were studied for prevalence and risk factors of hepatitis D virus (HDV) infection. The hepatitis B carrier rate among the three groups was 21, 15 and 20%, respectively, not significantly different from that of the general population in this area. However, the prevalence of HDV infection among carrier prostitutes was 55, 36 and 16%, respectively, much higher than that in general hepatitis B carriers. Univariate analysis revealed that the history of conducting paid sex for more than 12 months (P < 0.03), ear-piercing (P < 0.02), tattooing (P < 0.02), and gonorrhoea or syphilis (P < 0.005) were significant factors associated with HDV infection among these subjects. Multivariate analysis revealed that the history of ear-piercing and venereal diseases (P < 0.001) were still significant. In summary, genital ulcers caused by venereal diseases due to frequent sexual contact with multiple partners, and use of unsterilized needles in ear-piercing or tattooing play important roles in the high prevalence of HDV infection in prostitutes.

Hepatic actinomycosis with portal vein thrombosis mimicking hepatocellular carcinoma: a case report

A fatal case of hepatic actinomycosis with portal vein thrombosis is reported. The diagnosis of actinomycosis was delayed because of its rarity in Taiwan. This 63-year-old man was admitted due to body weight loss and poor appetite. No fever was noted before admission. Liver biochemical test showed a decreased serum albumin level with elevated serum levels of globulin and alkaline phosphatase. He was not a hepatitis B carrier and his serum level of alfafetoprotein was within normal range. Image studies (abdominal sonography and computed tomography) showed a hepatic mass over the medial segment of the left lobe with involvement of right lobe of the liver. Main portal vein thrombosis was also seen. Because of profound cachexia, he died of aspiration pneumonia and disseminated intravascular coagulation on the 11th day after admission. An autopsy revealed hepatic actinomycosis. High index of suspicion for early diagnosis and treatment is emphasized.

Ursodeoxycholic acid in the treatment of primary biliary cirrhosis: a short-term, randomized, double-blind controlled, cross-over study with long-term follow up

In order to evaluate the efficacy of ursodeoxycholic acid (UDCA) in the treatment of Chinese patients with primary biliary cirrhosis, a short-term, randomized, double-blind controlled, cross-over study was done with long-term follow up. In the first part of the study, 12 patients were randomly chosen to receive either UDCA 600 mg/day for 3 months followed by a placebo for 3 months or a placebo for 3 months followed by UDCA for 3 months. The clinical symptoms of pruritus improved when the patients were receiving UDCA but became worse when receiving a placebo. Mean serum levels of alkaline phosphatase (ALPase), gamma-glutamyl transferase (gamma-GT), total bilirubin, cholesterol, alanine aminotransferase (ALT) and aspartate aminotransferase all decreased below the baseline values when receiving UDCA treatment and all increased above the baseline values when receiving the placebo. The difference was statistically significant. In the second part of the study, 19 patients received long-term UDCA treatment (mean 20 months). The clinical symptoms of pruritus improved in 90% of the pruritic patients. Serum levels of ALPase, gamma-GT and ALT fell significantly from the pretreatment values, 6, 12 and from the mean 20 months after UDCA treatment. Serum levels of total bilirubin fell significantly 6 and 12 months after UDCA treatment but did not reach statistical significance at the last follow up. No patient lost antimitochondrial antibody and elevated immunoglobulin levels did not improve significantly, but the Mayo clinical risk score improved significantly after long-term UDCA treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Transport defects of rabbit inner medullary collecting duct cells in obstructive nephropathy

Urinary obstruction markedly reduces collecting duct Na+ reabsorption. To define the cellular mechanisms of this derangement in Na+ reabsorption in inner medullary collecting duct (IMCD) of obstructed kidneys, suspensions of intact IMCD cells and inner medulla plasma membranes (IMPM) were prepared from 24 h obstructed and untreated control kidneys. Oxygen consumption (QO2) studies revealed marked reductions in both amiloride-sensitive and ouabain-sensitive QO2 but not ouabain-insensitive QO2 in intact IMCD cells from obstructed, compared with control animals, indicating a reduction in oxygen-dependent transport activities of both the Na+ channel and the Na(+)-K(+)-adenosinetriphosphatase (ATPase). Amiloride-sensitive conductive 22Na+ uptake in intact IMCD cells from obstructed kidneys was significantly decreased by 45% at 10 s, 30 s, and 1-5 min (10 s: 2.42 +/- 0.63 vs. 4.49 +/- 0.64 nmol Na+ flux/mg protein, n = 7, P < 0.05; 1 min: 4.65 +/- 0.7 vs. 8.27 +/- 0.98 nmol Na+ flux/mg protein, n = 7, P < 0.05), indicating decreased activity of amiloride-sensitive Na+ channels in these cells. However, immunoblots of IMPM with antibodies to Na+ channel proteins did not show significant differences in content of Na+ channel proteins between membranes from obstructed and control groups. Ouabain-sensitive Na(+)-K(+)-ATPase activity in IMPM of obstructed kidneys was also reduced (61.1 +/- 18.1 vs. 152.6 +/- 25.8 nmol ATP degradation.min-1.mg protein-1, n = 6, P < 0.02), and immunoblots with monoclonal antibodies against the alpha 1- and beta-subunits of rabbit Na(+)-K(+)-ATPase showed a 51 +/- 7% reduction of both subunits in IMPM from obstructed kidneys (n = 4).(ABSTRACT TRUNCATED AT 250 WORDS)

Transport defects of rabbit medullary thick ascending limb cells in obstructive nephropathy

To characterize the sodium transport defect responsible for salt wasting in obstructive nephropathy, the major sodium transporters in the medullary thick ascending limb (mTAL), the apical Na-K-2Cl cotransporter and the basolateral Na-K-ATPase, were studied in fresh suspensions of mTAL cells and outer medulla plasma membranes prepared from obstructed and untreated kidneys. Oxygen consumption (QO2) studies in intact cells revealed marked reductions in the inhibitory effects of both furosemide and ouabain on QO2 in cells from obstructed, as compared with control animals, indicating a reduction in activities of both the Na-K-2Cl cotransporter and the Na-K-ATPase. Saturable [3H]bumetanide binding was reduced in membranes isolated from obstructed kidneys, but the Kd for [3H]bumetanide was unchanged, indicating a decrease in the number of functional luminal Na-K-2Cl cotransporters in obstructed mTAL. Ouabain sensitive Na-K-ATPase activity in plasma membranes was also reduced, and immunoblots using specific monoclonal antibodies directed against the alpha and beta subunits of rabbit Na-K-ATPase showed decreased amounts of both subunits in outer medullas of obstructed kidney. A significant decrease in [3H]bumetanide binding was detected after 4 h of ureteral obstruction, whereas Na-K-ATPase activity at this time was still not different from control. We conclude that ureteral obstruction reduces the amounts of both luminal Na-K-2Cl cotransporter and basolateral Na-K-ATPase in mTAL of obstructed kidney and that these reductions contribute to the salt wasting observed after release of obstruction.

A randomized controlled trial comparing octreotide and vasopressin in the control of acute esophageal variceal bleeding

This randomized controlled trial was conducted to compare the efficacy of intravenous infusion of octreotide (a synthetic long-acting somatostatin analogue) with vasopressin in 48 cirrhotic patients with endoscopically proven bleeding esophageal varices. Twenty-four patients received a continuous infusion of octreotide 25 micrograms/h for 24 h after an initial bolus of 100 micrograms and another 24 patients received a continuous infusion of vasopressin 0.4 U/min for 24 h. Bleeding was initially controlled after 6 h of drug infusion in 88% (21/24) and 54% (13/24) of the patients treated with octreotide and vasopressin respectively (p = 0.03). Complete control of bleeding after 24 h of drug infusion was achieved in 15 (63%) patients receiving octreotide and in 11 (46%) patients receiving vasopressin (p > 0.05). Side effects during drug infusion such as headache, chest pain and abdominal pain were significantly lower in the octreotide group (3/24) than in the vasopressin group (11/24). Serum gastrin and insulin levels fell significantly following octreotide infusion, but plasma glucose levels remained unchanged. Mortality related to bleeding esophageal varices was no different between the two groups. This report showed that octreotide infusion was more effective and had fewer side effects than vasopressin in initial controlling of acute esophageal variceal bleeding until an elective endoscopic sclerotherapy could be performed.

Current seroepidemiology of hepatitis D virus infection among hepatitis B surface antigen carriers of general and high-risk populations in Taiwan

In order to assess the current seroepidemiology of hepatitis D virus (HDV) infection in Taiwan where hepatitis B virus (HBV) is hyperendemic, a total of 756 voluntary blood donors, 641 prostitutes, 1,014 patients with sexually transmitted diseases (STDs), and 628 drug abusers were studied. Radioimmunoassays were used for testing HBV infection markers and antibody against HDV (anti-HDV) among HBsAg carriers. The anti-HDV prevalence among HBsAg carriers was significantly higher in STD patients (9.6%), prostitutes (33.1%), and drug abusers (68.1%) than in blood donors from the general population (2.2%). The prevalence gradually increased with age in blood donors and STD patients, but reached a plateau at a young age in prostitutes and drug abusers. Males had a higher prevalence than females in blood donors (2.7% vs. 0), STD patients (8.2% vs. 7.5%), and drug abusers (69.0% vs. 57.1%), but the difference was not statistically significant. STD patients with syphilis had a higher prevalence (19.5%) than those affected with non-ulcerating STDs (5.3%). While unlicensed prostitutes had a lower prevalence (13.6%) than licensed prostitutes (44.9%), intravenous drug abusers had a higher prevalence (73.1%) than non-intravenous drug abusers (34.6%). There was a twofold increase in anti-HDV prevalence from 1986 to 1989 among prostitutes, but the prevalence remained unchanged in the general population and drug abusers. HDV infection remains limited to the high-risk groups and spread mainly by promiscuity and needle sharing in Taiwan.

Hypercholesterolaemia in patients with hepatocellular carcinoma

Ninety-one (11.4%) subjects with hypercholesterolaemia (serum cholesterol level more than 250 mg/dL) of 792 Chinese patients with hepatocellular carcinoma (HCC) were studied in Taiwan. All 91 patients had large tumours greater than 7 cm in diameter and a tumour volume greater than 50%; 56 (61%) of these patients manifested tumour involvement in both lobes of the liver. The HCC patients with hypercholesterolaemia had significantly higher mean serum levels of albumin, triglyceride and alpha-fetoprotein (AFP) compared with age-sex-tumour volume matched HCC patients without hypercholesterolaemia. The associated incidence of hypoglycaemia in hypercholesterolaemic HCC patients was significantly higher than in HCC patients without hypercholesterolaemia (15/90 vs 4/90; P = 0.01). There was no significant difference in the survival analysis between HCC patients with and without hypercholesterolaemia. Eight and 11 of hypercholesterolaemic HCC patients had their tumours surgically resected and received transcatheter hepatic arterial chemoembolization (TAE), respectively. Serum cholesterol levels fell to the normal range after treatment and rose to abnormal levels again when tumours recurred after surgery or progressively enlarged after TAE. The change in pattern of serum cholesterol was parallel to the change in serum AFP. Serum cholesterol levels may serve as another marker in identifying tumour recurrence and the presence of a viable tumour mass in hypercholesterolaemic HCC patients who have received surgical resection or TAE.

Different sensory blockade of interscalene versus axillary approach of brachial plexus block

We examined results of brachial plexus block in 31 young male patients who underwent upper extremity surgical procedures. Interscalene block was performed using a paresthesia technique in 13 patients and axillary block, using the perivascular technique, in 18 patients. In both groups, 30 ml 1.5% lidocaine with 1:200,000 epinephrine was injected. Sensory blockade was evaluated at 5 min and 15 min after injection, determined by pinprick. Results showed that the interscalene technique preferentially blocked the cephalad nerves while the axillary technique produced similar block of both cephalad and caudal nerves of the brachial plexus. Difference between groups was statistically significant, suggesting that the extent of nerve block depends on the technique of approach per se. The difference in patterns of nerve blocked by either technique could be due to the access of local anesthetic to the different components of plexus in the sheath.

[Comparison of anesthetic morbidity and mortality before and after the implementation of quality assurance in Tri-Service General Hospital]

The desire to improve anesthetic outcome is a cornerstone in modern anesthesia. There are many means to reach this goal, such as enforcement in personal training, elevation of monitoring standards, constant vigilance and stern quality assurance (QA). The department of Anesthesiology, Tri-Service General Hospital, has adopted the QA program and implemented it since March 1, 1990. Because there were no significant differences in terms of personnel training, monitoring standards and types of anesthesia and surgery before and after the application of QA program, we investigated the effects of QA on anesthetic major morbidity and coma/mortality. We analyzed the anesthetic results obtained in two separate periods respectively spanning from Jan. 1, 1989 to Dec. 31, 1989 and from Mar. 1, 1990 to Feb. 28, 1991. During the first two months of 1990, the department's personnel were trained to be familiar with the QA program. We compared the anesthetic major morbidity and coma/mortality of one year before the implementation of QA with those in a one-year period after its implementation. Before and after enforcement of QA, there were no significant differences (p greater than 0.05) regarding major morbidity and coma/mortality, but the rates of anesthetic complications were lower after the practice of QA program. Since the functions of QA was aimed at alerting the anesthetic personnel to keep constant vigilance over the act of anesthesia, QA in theory could reduce anesthetic accidents and mishaps related jointly to surgery and anesthesia. The reason why QA did not decrease anesthetic major morbidity and coma/mortality in this study may be due to limited number of anesthesia in relatively short period.(ABSTRACT TRUNCATED AT 250 WORDS)

The prevalence of anti-hepatitis C virus among Chinese patients with hepatocellular carcinoma

To evaluate the role of hepatitis C virus (HCV) in Chinese patients with hepatocellular carcinoma (HCC), the antibodies to HCV (anti-HCV) were detected by enzyme immunoassay in 41 (12.6%) of the 326 patients with HCC. However, none of 35 patients with metastatic carcinoma of the liver had detectable anti-HCV. The prevalence of anti-HCV was significantly higher in patients with hepatitis B surface antigen (HBsAg)-negative HCC than those with HBsAg-positive HCC (37.3% versus 4.1%, P less than 0.0001). However, the prevalence of anti-HCV was much higher in patients with HCC with negative results for HBsAg and antibody to hepatitis B core antigen (54.5%). The mean age of patients with HCC with positive results for anti-HCV was significantly greater than that of patients with HBsAg-positive HCC (65.1 versus 55.5 years, P less than 0.0001). Alpha-fetoprotein levels greater than 20 ng/ml were found in 70.7% of patients with HCC with positive results for anti-HCV and in 73.3% of patients with HBsAg-positive HCC. Of the Chinese patients with HCC, 74.5% had HBsAg-positive results and 96.6% had positive results for antibody to hepatitis core antigen. These data indicate that, although HCV may play an etiologic role in HCC, hepatitis B virus is still the most important causal agent among most Chinese patients with HCC.

The prevalence of anti-hepatitis C virus among Chinese patients with hepatocellular carcinoma

To evaluate the role of hepatitis C virus (HCV) in Chinese patients with hepatocellular carcinoma (HCC), the antibodies to HCV (anti-HCV) were detected by enzyme immunoassay in 41 (12.6%) of the 326 patients with HCC. However, none of 35 patients with metastatic carcinoma of the liver had detectable anti-HCV. The prevalence of anti-HCV was significantly higher in patients with hepatitis B surface antigen (HBsAg)-negative HCC than those with HBsAg-positive HCC (37.3% versus 4.1%, P less than 0.0001). However, the prevalence of anti-HCV was much higher in patients with HCC with negative results for HBsAg and antibody to hepatitis B core antigen (54.5%). The mean age of patients with HCC with positive results for anti-HCV was significantly greater than that of patients with HBsAg-positive HCC (65.1 versus 55.5 years, P less than 0.0001). Alpha-fetoprotein levels greater than 20 ng/ml were found in 70.7% of patients with HCC with positive results for anti-HCV and in 73.3% of patients with HBsAg-positive HCC. Of the Chinese patients with HCC, 74.5% had HBsAg-positive results and 96.6% had positive results for antibody to hepatitis core antigen. These data indicate that, although HCV may play an etiologic role in HCC, hepatitis B virus is still the most important causal agent among most Chinese patients with HCC.

Comparisons of the effects of calcium carbonate and calcium acetate on zinc tolerance test in hemodialysis patients

Because aluminum hydroxide, as a phosphate binder, lowered intestinal zinc absorption, we studied the effects of calcium carbonate (CaCO3) and calcium acetate (CaAc), two other phosphate binders, on intestinal Zn absorption in nine patients on hemodialysis and in 11 controls by measuring 1- and 2-hour serum Zn levels after oral administration of 50 mg of elemental Zn as Zn gluconate with or without concomitant administration of 2 g CaCO3 (800 mg elemental Ca) or 3 g CaAc (750 mg elemental Ca). Fasting serum Zn levels were not different between patients and controls (14.0 +/- 2.3 v 14.1 +/- 1.2 mumol/L [91.8 +/- 14.9 v 92.3 +/- 8.0 micrograms/dL]), but the area under the curve of serum Zn increment (AUC) 2 hours after an oral Zn challenge without or with either of two of phosphate binders used was significantly smaller in patients than in controls (P less than 0.05). The AUC after concomitant administration of Zn with CaCO3 did not differ from that of Zn alone in either patients or controls, but it was significantly less in Zn with CaAc than in Zn alone or in Zn with CaCO3 in both groups. The results demonstrate that intestinal Zn absorption after an oral Zn challenge decreased in patients on hemodialysis and concomitant administration of CaAc, but CaCO3 did not decrease intestinal Zn absorption in either group.