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Biomedical subjects

C L Lai

Publications and source records attributed to C L Lai.

At least 37 records · Page 2Linked to original sources

Liver transplantation in Asian patients with chronic hepatitis B using lamivudine prophylaxis.

OBJECTIVE: To report the results of liver transplantation in 31 Asian patients with chronic hepatitis B using lamivudine prophylaxis in an open-label study. SUMMARY BACKGROUND DATA: Chronic hepatitis B is a prevalent cause of end-stage liver disease in Asia, but the results of liver transplantation in these patients are poor. METHODS: Thirty-one Asian patients with chronic hepatitis B underwent liver transplantation using lamivudine prophylaxis (100 mg daily). Twenty-three (74%) patients had detectable serum hepatitis B envelope antigen (n = 18) or hepatitis B virus DNA (n = 11) before treatment, and seven had associated hepatocellular carcinoma. Lamivudine was continued indefinitely after transplantation, and hepatitis B immune globulin was not used. RESULTS: The actuarial patient and graft survival rates were 84% and 81%, respectively. Five patients died of causes unrelated to hepatitis B, and 26 patients were alive at a median follow-up of 16 months (range 6-47) after transplantation. One (3.8%) patient developed recurrent hepatitis B resulting from viral breakthrough at week 53 and survived after retransplantation using adefovir and hepatitis B immune globulin treatment. The remaining 25 surviving patients had no biochemical or histologic evidence of recurrent hepatitis, and serum hepatitis B virus DNA remained negative by polymerase chain reaction. In six patients, hepatitis B surface antigen (HBsAg) persisted or reappeared in serum. Among 19 patients who became negative for HBsAg from 5 to 431 days after transplantation, 13 developed anti-HBsAb that lasted a median of 6 months (range 1-21). None of the seven patients with hepatocellular carcinoma developed recurrent tumor. CONCLUSIONS: Asian patients with chronic hepatitis B may achieve a good outcome after liver transplantation using lamivudine prophylaxis.

Adolescent↗

The accuracy of SM-HCV rapid test for the detection of antibody to hepatitis C virus.

OBJECTIVE: Conventional tests for antibody to hepatitis C virus (HCV) require considerable time before results are available. The aim of this study is to examine the accuracy of a new quick test (SM-HCV Rapid Test) for the detection of antibody to hepatitis C virus with reference to the well-established third generation enzyme immunoblot assay (EIA-3; Abbott Laboratories, Chicago, IL). METHODS: A total of 290 subjects (100 patients with chronic hepatitis C infections, 95 patients with other chronic liver diseases, 95 healthy subjects) were recruited. Thirty microliters of serum was tested for anti-HCV by SM-HCV Rapid Test according to the manufacturer's instruction. Liver function tests and serum HCV RNA by polymerase chain reaction (PCR) were measured. RESULTS: In the 100 patients positive for anti-HCV by EIA-3, 98 of these patients were also positive for anti-HCV by SM-HCV Rapid Test. In the 95 patients with other chronic liver diseases, 94 samples were negative for anti-HCV by both EIA-3 and SM-HCV Rapid Test. The remaining one patient was positive for anti-HCV by the EIA-3 but negative by the SM-HCV Rapid Test. In the 95 controls, which were negative for anti-HCV by EIA-3, all were also negative for anti-HCV by SM-HCV Rapid Test and HCV RNA by PCR. Using EIA-3 as the gold standard screening test for anti-HCV, the sensitivity and the specificity of SM-HCV Rapid Test were 98% and 100%, respectively. The positive predictive value and negative predictive value of SM-HCV Rapid Test were 100% and 97.9%, respectively. CONCLUSIONS: SM-HCV Rapid Test is a reliable test with high sensitivity and specificity. The anti-HCV result can be available within a very short period of time. It is a useful screening test for anti-HCV.

Adolescent↗

Soluble E-cadherin is a valid prognostic marker in gastric carcinoma.

BACKGROUND: Gastric cancer remains a major cause of cancer mortality globally but no good prognostic tumour marker is available. Soluble fragment of E-cadherin protein has been reported to increase in the sera of patients with cancer and recently was found to be elevated in 67% of patients with gastric cancer. AIMS: To investigate if serum soluble E-cadherin is a valid prognostic marker in gastric cancer. METHODS: Concentrations of soluble E-cadherin from 116 patients with histologically confirmed gastric adenocarcinoma and 40 healthy subjects were measured using an immunoenzymometric method with a commercially available sandwich ELISA kit based on monoclonal antibodies. RESULTS: The logarithm of the means of soluble E-cadherin concentration was significantly higher in patients with gastric cancers (mean 3.85 (SD 0.28)) than in healthy subjects (3.71 (0.18)) (p=0.001), and in palliative/conservatively treated cancers (3.91 (0.35)) than in operable cancers (3.78 (0.19)) (p=0.015). The logarithm of the concentrations correlated with tumour size (p=0.032) and carcinoembryonic antigen concentrations (p=0.001). The cut off value calculated from discriminant analysis on operability and inoperability/palliative treatment was 7025 ng/ml. Soluble E-cadherin concentrations higher than this cut off value predicted tumour (T4) depth invasion (p=0.020, confidence interval (CI) 1.008-1.668) and palliative/conservative treatment (p=0.023, CI 1.038-2.514). In contrast, the relative risks for lymph node (N2) metastasis, distant metastasis, and stage III/IV disease were 1.41, 1.33, and 1.55 respectively, despite not reaching statistical significance. CONCLUSION: Serum soluble E-cadherin is a potential valid prognostic marker for gastric cancer. A high concentration predicts palliative/conservative treatment and T4 invasion.

Adenocarcinoma↗

Low molecular weight heparin-induced liver toxicity.

The authors report two cases of hepatotoxicity induced by low molecular weight heparin. A 26-year-old woman and a 33-year-old man were treated with low molecular weight heparin for pulmonary embolism and cerebral infarction, respectively. They both developed derangement in liver function tests a few days after commencement of the low molecular weight heparin. The derangement in liver function tests was associated with a decreased serum complement 3 activity. Their liver functions recovered over a period of 2 to 3 months after low molecular weight heparin was stopped. Liver biopsy in the woman demonstrated balloon degeneration with scattered foci of hepatocytic necrosis, suggesting a complement-mediated hepatocellular damage.

Adult↗

Ambulance utilization in metropolitan and rural areas in Taiwan.

BACKGROUND AND PURPOSE: Emergency medical services (EMS) have expanded rapidly in the Asian developing countries recently. However, the patterns of ambulance utilization in the rural and urban areas of these countries have not been thoroughly described. This study investigated the patterns of ambulance utilization in two urban areas and the larger rural area of Taiwan formerly designated Taiwan Province. METHODS: We studied a total of 304,368 ambulance missions during 1997 in Taiwan. We analyzed the differences in the characteristics of emergency calls and the interventions performed on the scene in two urban areas, Taipei City and Kaohsiung City, and in the rural area formerly designated Taiwan Province. RESULTS: The call volume and percentage of non-transport calls were higher in the more developed of the two urban areas, Taipei City, than in Kaohsiung (p < 0.01). The incidence of calls with trauma-related causes was higher in both urban areas. However, the percentage of calls placed for trauma-related reasons was higher in the rural area (p < 0.01). More calls for acute medical illness were placed in Taipei City (p < 0.01) than in the rural area. The number of interventions performed by ambulance staff was higher in Taipei City and Kaohsiung City than in the rural area (p < 0.01). The availability of acute illness management was generally lower than needed in all areas. CONCLUSIONS: Call volume and the number of interventions performed were higher in the urban area, whereas the percentage of trauma-related calls was higher in the rural area. These findings suggest that EMS use patterns in Taiwan are transitioning towards a pattern characteristic of a more developed country. The differences in ambulance utilization patterns must be considered in plans to further develop EMS services in these areas.

Ambulances↗

Fish allergy in atopic children.

The prevalence of fish allergy among 11 atopic children with elevated levels of specific immunoglobulin (Ig) E for cod was determined. None of the children had a history of fish allergy. All of the children had asthma and allergic rhinitis and 5 of them had also atopic dermatitis. The children underwent allergy skin tests (codfish, tuna, catfish, salmon, flounder, and bass), specific IgE tests (salmon, trout, tuna, eel, and mackerel), and food challenge tests. Skin tests in cod-specific IgE-positive children were positive for codfish in 4 children, tuna in 2, catfish in 2, salmon in 6, flounder in one, and bass in 2. Three children had elevated specific IgE for salmon, 5 for trout, 8 for tuna, 4 for eel, and 4 for mackerel. Oral fish challenge with 10 g of fish did not result in positive reaction in any of the children. In conclusion, a positive food challenge test provided the only definitive confirmation of fish allergy, whereas positive allergy skin tests or positive specific IgE tests were less reliable. Skin tests and in vitro specific IgE assays were not correlated with clinical symptoms of fish allergy, and the results of these 2 tests did not correlate with each other in this study.

Anaphylaxis↗

The recovery potential of central conduction disorder in hypothyroid rats.

In an aim to detect the dysfunction of central nervous system among rats with varied durations of hypothyroidism and to elucidate the recovery potential after thyroxine replacement, a series of BAEP were conducted and compared with age-matched controls. BAEP was performed in five groups of the hypothyroid animals 1, 3, 5, 7, and 9 months after thyroidectomy respectively. Following initial electrophysiological assessment, thyroxine replacement was administered to each group of hypothyroid rats, and BAEP was performed at two month intervals, up to two successive normal studies or six months after the initiation of therapy, whichever came first. Before thyroxine treatment, prolonged I-V interpeak latency was the most consistent abnormal finding in all groups of hypothyroid rats, and longer hypothyroid state correlated well with more severe central conduction disorder. Hearing impairment was also noted among those with long duration of hypothyroidism. After thyroxine replacement, the central conduction dysfunction usually returned to normal if the hypothyroid state was not more than 5 months in duration. However, when hypothyroid state persisted over 7 months or more, there would be an incomplete recovery for central conduction disorder. The present study brings out the concept of 'therapeutic window' in reversing the central nervous dysfunction caused by hypothyroidism in adult rats.

Age Factors↗

Profound suppression of hepatitis B virus replication with lamivudine.

The therapeutic goals in chronic hepatitis B are to prevent or decrease cirrhosis and hepatocellular carcinoma in patients with pre-cirrhotic or early cirrhotic disease and to stabilise patients with end-stage cirrhosis. Lamivudine is an oral nucleoside analogue that suppresses hepatitis B virus (HBV) replication, and so may achieve both these treatment objectives. The active 5'-triphosphate metabolite of lamivudine has two modes of viral suppression. First, it mimics deoxycytidine triphosphate and is incorporated into newly synthesised HBV DNA to cause chain termination. Second, it demonstrates competitive inhibition of viral DNA-dependent and RNA-dependent DNA polymerase activity (i.e., reverse transcriptase activity). Lamivudine may, therefore, act at four possible stages during HBV replication: reverse transcription of pre-genomic mRNA into nascent minus-strand DNA; formation of plus strand DNA from nascent minus-strand DNA; completion of double-stranded DNA; and formation of covalently closed circular DNA. In clinical studies, lamivudine therapy reduced serum HBV DNA and this was associated with significant improvements in liver histology and significant and sustained enhancement of the proliferative CD4-mediated response to HBeAg and hepatitis B core antigen (HBcAg), and an increased frequency of HBeAg-specific T cells. HBV DNA concentrations often returned to pre-treatment values when therapy ended prior to the loss of hepatitis B e antigen (HBeAg). Although the emergence of HBV variants with a mutation in the YMDD (tyrosine-methionine-aspartate-aspartate) motif has been observed, such variants show reduced susceptibility to lamivudine due to limited replication competence, and their emergence is not a signal to cease lamivudine therapy. In conclusion, viral suppression with lamivudine offers a means of disease improvement and immunological control in chronic hepatitis B.

Antiviral Agents↗

Antituberculosis drug-related liver dysfunction in chronic hepatitis B infection.

Liver toxicity is a common side effect of antituberculosis (anti-TB) drugs. We studied the differences in liver dysfunction observed during anti-TB treatment between hepatitis B virus carriers (HBV) and noncarriers. Three hundred twenty-four patients on anti-TB drugs were recruited and followed up for 1 year. Forty-three patients with HBV and 276 non-HBV patients were included for analysis. Liver function tests and viral markers were monitored monthly. Liver biopsy was requested whenever the alanine transaminase (ALT) was persistently abnormal. Eighty-six HBV carriers who were not given anti-TB drugs were chosen as a second control and evaluated prospectively. The incidence of liver dysfunction was significantly higher in HBV carriers given anti-TB drugs (34.9%) when compared to noncarriers (9.4%, P <.001) and with HBV carriers not given anti-TB drugs (8.1%, P <.001). For patients given anti-TB drugs, HBV carriers who developed liver dysfunction were younger (P =.011) and had more severe liver injury compared with noncarriers (P =.008). By multiple logistic regression analysis, age (P =.002) and hepatitis B infection (P <.001) were the only 2 significant risk factors for hepatotoxicity related to anti-TB therapy.

Adult↗

Early detection of hepatocellular carcinoma increases the chance of treatment: Hong Kong experience.

The prognosis for patients with hepatocellular carcinoma (HCC) is poor because of the low chance of curative treatment. To increase the chance of intervention and to improve survival, early detection of subclinical HCC (SCHCC) by alpha-fetoprotein (AFP) and/or ultrasonography (USG) screening is implemented in many countries. Three hundred six Chinese patients with HCC diagnosed between January 1995 and December 1997 were recruited. They were categorized into two groups: 142 patients (group 1) had SCHCC diagnosed by screening (AFP and/or USG), and 164 patients (group 2) presented with symptomatic HCC. The tumor size was significantly smaller in group 1 compared with that of group 2 (3.5 cm vs. 8.1 cm; P <.0001). A significantly higher proportion of patients had bilobar involvement, multifocal HCC, diffuse-type HCC, portal vein infiltration, and distant metastasis in group 2 when compared with group 1. Operability and feasibility of treatment by transcatheter intra-arterial chemoembolization (TACE) in group 1 patients (26.8% and 45.1%, respectively) were significantly better than in group 2 patients (7.9% and 32.3%, P <.0001 and P =.03, respectively). The cumulative survival rate was significantly higher in group 1 than in group 2 (P <.0001). For those who had surgical resection and those who had TACE, group 1 patients had a higher cumulative survival rate compared with that of group 2 patients (P =.04 and P =.0003, respectively). Screening for HCC by AFP and/or USG can identify tumors at an early stage, resulting in a higher chance of receiving treatment. Whether it can improve survival requires a further prospective, randomized study.

Adult↗

(13)C-urea breath test without a test meal is highly accurate for the detection of Helicobacter pylori infection in Chinese.

BACKGROUND: Conventional (13)C-urea breath testing ((13)C-UBT) includes a test meal to delay gastric emptying, which, theoretically, improves the accuracy of the test. Citric acid has been proposed as the best test meal. However, recent studies have suggested that a test meal may not be necessary. AIM: To investigate a new (13)C-UBT protocol without a test meal in a Chinese population. METHODS: Consecutive dyspeptic patients referred for upper endoscopy were recruited. (13)C-UBT was performed on two separate days with or without a test meal (2.4 Gm citric acid) and compared with the 'gold standard' (CLO test and histology). RESULTS: Two hundred and two patients were tested. Using receiver operating characteristics (ROC) analysis, the optimal delta-value and optimal measurement interval for UBT were 5% and 30 min, respectively, both with or without a test meal. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of (13)C-UBT with citric acid (96.5%, 97.7%, 98.2%, 95.6%, 97.0%) were similar to (13)C-UBT without a test meal (94.7%, 97.7%, 98.2%, 93.5%, 96.0%). CONCLUSION: This simplified (13)C-UBT protocol without a test meal produced highly accurate and reliable results in the Chinese population.

Adolescent↗

Natural history of chronic hepatitis B virus infection.

In chronic hepatitis B virus (HBV) infection acquired during adulthood, which is the type mostly seen in the Caucasian population, there is biochemical and histologic regression after HBeAg seroconversion, and the risk of death from hepatitis B-related causes is low. In chronic HBV infection acquired during birth or early childhood, which is the type most commonly seen in the Asian population, there is a prolonged phase of immunotolerance. The immune clearance phase is characterized by multiple acute exacerbations preceeded by elevations in serum HBV DNA levels, HBeAg concentration and HBeAg/anti-HBe immune complexes. Of these patients, 2.4% may develop hepatic decompensation during the stage of HBeAg seroconversion. The development of cirrhosis occurs more frequently in patients with episodes of decompensation and with repeated severe acute exacerbations. However progression to cirrhosis can be relatively silent and can occur even in children. After HBeAg seroconversion, precore and core promotor mutations occur frequently in the Asian population. However, there is little correlation between the occurrence of these mutations and alanine aminotransferase elevation in patients who are positive for anti-HBe. Although cirrhosis develops during the process of HBeAg seroconversion, 68% of the complications of cirrhosis and of hepatocellular carcinoma occur after HBeAg seroconversion. These complications may still occur even after HBsAg seroclearance.

Adult↗

Effects of extended lamivudine therapy in Asian patients with chronic hepatitis B. Asia Hepatitis Lamivudine Study Group.

BACKGROUND & AIMS: One-year lamivudine therapy significantly suppressed hepatitis B virus (HBV) replication, improved hepatic necroinflammatory activity, and prevented progression of fibrosis. However, the effects of prolonged therapy are unknown. METHODS: A total of 334 Asian patients with chronic hepatitis B from a previously reported 1-year study were randomized to receive either lamivudine (100 or 25 mg) or placebo for another year. The effects of treatment on serum HBV-DNA suppression, alanine transaminase (ALT) normalization, and hepatitis B e antigen (HBeAg) seroconversion were measured. The presence of YMDD variant HBV and its effect were also determined. RESULTS: A significantly greater proportion of patients achieved sustained HBV-DNA suppression and ALT normalization with 100 mg lamivudine daily for 2 years compared with lamivudine for 1 year followed by placebo for the second year (P<0.001). Daily lamivudine therapy for 2 years was safe and resulted in incremental HBeAg seroconversion from 17% at week 52 to 27% at week 104. HBeAg seroconversion during continued lamivudine therapy increased linearly with increasing pretherapy ALT levels (P< 0.001). Despite the emergence of YMDD mutant in 38% of the patients, they continued to clear serum HBeAg and maintain lower median serum HBV-DNA and ALT levels than baseline values. In contrast, ALT levels increased 8-12 weeks after switching from lamivudine to placebo, but returned to normal once lamivudine treatment was resumed. CONCLUSIONS: Treatment with lamivudine for 2 years is both well tolerated and efficacious in patients with chronic hepatitis B.

Adult↗

Sinus node dysfunction in a patient with lithium intoxication.

Lithium can suppress sinus node function, especially when it is used concomitantly with carbamazepine. We describe a 42-year-old woman who took lithium and carbamazepine for manic-depressive psychosis and seizure disorders, and developed marked sinus node dysfunction. Drug screening showed a toxic serum lithium level of 3.38 mmol/L and a normal serum carbamazepine level of 22.1 mumol/L. An electrophysiologic study showed prolongation of the corrected sinus node recovery time (CSNRT) of up to 9,708 msec. After three sessions of hemodialysis, normal sinus rhythm was resumed. The serum lithium level was 0.1 mmol/L 2 weeks later, and the CSNRT shortened to 309 msec. Because the combination of lithium and carbamazepine in psychiatric patients is not uncommon, recognition of the potential complication of severe bradyarrhythmia is essential in the emergency care of such patients.

Adult↗