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Biomedical subjects

C L Lai

Publications and source records attributed to C L Lai.

At least 91 records · Page 5Linked to original sources
PubMed1997

Foreign body aspiration into the lower airway in Chinese adults.

OBJECTIVES: Foreign body aspiration into the lower airway in adults is uncommon. We designed this study to investigate the clinical presentations, precipitating factors, management choice, and complications of foreign body aspiration in Chinese adults. PATIENTS AND METHODS: We analyzed 43 consecutive adult patients with foreign body aspiration between February 1980 and December 1995 from the medical record registry and cross index system of a tertiary medical center. RESULTS: The most common symptoms are chronic cough, hemoptsis, fever, and dyspnea. Only three patients (7%) presented with choking. Chest radiograph demonstrated the foreign body in nine cases (21%). The most common foreign body was bone fragments (21/43, 49%). Lodgment is more common in the right, especially the right intermediate bronchus and basal bronchus. Three patients were also diagnosed as having lung cancers. Precipitating factors include CNS dysfunction, facial trauma, intubation, dental procedure, and underlying pulmonary diseases. Flexible fiberoptic bronchoscopy removed the foreign body in 25 cases (58%) during the first attempt and 32 cases (74%) in total. Complications include obstructive pneumonitis (including one case of actinomycosis infection), atelectasis, bronchiectasis, lung abscess, and lung torsion (two cases). CONCLUSION: The nature of foreign body in Chinese adults was different from the Western adults. The initial clues to foreign body aspiration in adults are usually obscure or indirect. We suggest flexible fiberoptic bronchoscopy as the first-line approach. Follow-up bronchoscopy and chest radiograph are recommended to detect chronic complications or coexisting lung cancer.

Adult↗
PubMed1997

An update on hepatocarcinogenesis.

Hepatocellular carcinoma is the most common cancer occurring in males in the world and has an annual incidence worldwide of 1 million. There are variations in its geographical distribution. It is the second most common cancer in Southeast Asia, including Hong Kong and ranks third among males in China.

Journal Article↗
PubMed1997

The natural history of chronic hepatitis B infection.

Chronic hepatitis B infection is a global health problem that affects about 300 million people. Of these, 75% are Chinese. Most Chinese who become chronic carriers, contract the virus during the perinatal period. The natural history of these chronic hepatitis B carriers includes an initial immune tolerance phase, followed by immune clearance and an inactive hepatitis B non-replicative phase with the development of cirrhosis that may be complicated by hepatocellular carcinoma. The classification of hepato-cellular carcinoma has recently been revised. Based on immunohistochemical studies, it has been found that patients with hepatocellular carcinoma and biliary markers have a poorer survival than patients with hepatocellular carcinoma but who have negative biliary markers. Sometimes, a fourth phase, a hepatitis B envelope-negative hepatitis B virus replicative phase, reflecting the emergence of a pre-core mutant strain, may follow. Our improved understanding of the natural history of chronic hepatitis B infection has led to more effective approaches towards the control of this viral infection and its sequelae. Most importantly, immunisation against hepatitis B virus in the perinatal setting has been shown to prevent chronic infection.

Journal Article↗
PubMed1997

Antiviral treatment for chronic hepatitis B.

An updated review of the antiviral agents currently available or under trial for the treatment of chronic hepatitis B is presented. There are two broad groups: (1) immunomodulators including interferon a (which also has a direct antiviral effect), thymosin a1 and Theradigm-HBV and (2) viral suppressors such as famciclovir and lamivudine. These agents are still in clinical trial worldwide, singly or in combination. Their long term efficacy in the treatment of hepatitis B remains to be evaluated.

Journal Article↗
PubMed1997

Management of fulminant hepatic failure at Queen Mary Hospital.

OBJECTIVE: To evaluate the strategy of the management of patients with fulminant hepatic failure at Queen Mary Hospital. METHODS: In the period 1994 through 1996, 30 patients with fulminant hepatic failure were managed by active supportive treatment in the Intensive Care Unit in preparation for liver transplantation. Liver transplantation was performed in 14 patients (aged 17-47), 3 of whom received liver grafts from brain-stem dead donors and 11 received live-related grafts from family members. The median duration from admission to liver transplantation was 3 days (range: 1-6 days). RESULTS: Thirteen patients (93%) survived the liver transplantation and are well after a median period of follow-up of 7 months. The only mortality was in a patient with pre-exiting renal transplantation and hepatitis B infection, who died from intra-abdominal candidiasis. CONCLUSION: The strategy of active supportive treatment and early liver transplantation using live-related liver graft is probably the key to the success of the management of fulminant hepatic failure in our series.

Adolescent↗
PubMed1996

Minimum graft volume for successful adult-to-adult living donor liver transplantation for fulminant hepatic failure.

The major limitation of adult-to-adult living donor liver transplantation is the adequacy of the size of the graft that can be safely harvested from the donor. The present report describes a 22-year-old woman with stage 4 hepatic coma due to fulminant hepatic failure who was successfully treated using a small-for-size left lobe graft from her father. The graft weight was 0.6% of the recipient's body weight, or 25% of her ideal liver weight. Avoidance of warm ischemia, short cold ischemic time, and early treatment of rejection are important elements in optimizing small-for-size graft function. Since the left lobe represents 23-36% of the total liver volume of an adult, it is possible, in most cases, to harvest a left lobe graft of adequate size from a donor of similar size as the recipient.

Adult↗
PubMed1996

Detection and clinical features of hepatitis C virus type 6 infections in blood donors from Hong Kong.

The genotype distribution of hepatitis C virus (HCV) was investigated in 212 viraemic blood donors from Hong Kong. A subset of the samples was investigated using three different genotyping assays to establish the accuracy of each in this population. These assays were restriction fragment length polymorphism (RFLP) of amplified 5' noncoding region (5'NCR) sequences, RFLP of the core region, and a serotyping assay using peptides from two antigenic regions of NS4. Genotypes detected in Hong Kong blood donors were 1a (6.2%), 1b (58.8%), 2a (1.4%), 2b (1.4%), 3a (1.9%), and 6a (27.0%). All genotyping assays produced concordant results. No evidence was obtained for the presence of type 6 group variants recently identified in Southeast Asia, other than type 6a. A serotyping assay based upon the detection of type-specific antibody to epitopes in NS4 produced similar results to the genotyping assays (98% concordance), but a reduced sensitivity (75%) compared with genotyping methods. Sequence variation in NS4 was not the cause of the reduced rate of detection of type 6 antibody in this population. Eighty-four percent donors infected with type 6a were male, compared to 75% donors infected with type 1b. The median alanine transaminase (ALT) level in type 6 infected donors was lower than in type 1b, (43.8 and 51.1 U/l, respectively) although these values were not statistically significant (P = 0.094). There was no significant difference between the ages of donors infected with types 1b and 6a. Risk factors for HCV infection in the blood donors included blood transfusion, intravenous drug abuse, and tattooing. A significantly greater number of donors infected with HCV-6a reported a history of drug abuse (66%) than donors infected with HCV-1b (7%).

Adolescent↗
PubMed1996

Transesophageal echocardiography in the detection of inferior vena cava and cardiac metastasis in hepatocellular carcinoma.

Antemortem diagnosis of inferior vena cava (IVC) and cardiac metastasis of hepatocellular carcinoma (HCC) is difficult but important before consideration of curative resection. There are only a few cases of cardiac metastasis of HCC which have been diagnosed antemortem by echocardiography. Accordingly, 18 consecutive patients with HCC who were potential candidates for curative resection were studied by transthoracic (TTE) and transesophageal echocardiography (TEE). One (6%) and two (11%) patients had cardiac and IVC metastasis of HCC, respectively, which was detected by two-dimensional TTE. In contrast, by using TEE, four patients (22%) showed tumor invasion of the IVC, of whom two (11%) had tumor mass extending into the right atrium (RA). There was no significant difference in age, serum level of alpha-fetoprotein, and percentage of right liver lobar involvement between those with and without cardiac metastasis. Patients without cardiac metastasis detected on TTE or TEE had significantly longer mean duration of survival (5.0 +/- 2.1 vs. 2.1 +/- 1.0 months; p < 0.05). In summary, TEE may be more useful than TTE in the detection of cardiac metastasis of HCC, which occurred in 22% of patients whose primary tumor was considered to be surgically resectable in our series. This can be safely performed in patients with HCC and can provide optimal visualization of the IVC and RA. The high prevalence of subclinical cardiac metastasis in HCC mandates the use of TEE in all patients with HCC prior to surgical intervention.

Age Factors↗
PubMed1996

Hepatic expression of hepatitis B virus genome in chronic hepatitis B virus infection.

The expression of hepatitis B virus (HBV) DNA in the liver was studied by nonisotopic in situ hybridization and correlated with liver histology, different phases in the natural evolution of chronic hepatitis B, and hepatic expression of HBV antigens in 251 Chinese patients with chronic HBV infection. A good correlation was found between the detection of HBV-DNA by in situ hybridization and serum HBV-DNA (P < .01). Chronic active hepatitis had the highest HBV-DNA detected in cytoplasm and nuclei, compared with livers showing minimal change, chronic persistent hepatitis, cirrhosis, and hepatocellular carcinoma. HBV-DNA in cytoplasm exceeded HBV-DNA in nucleus in all patients except in livers with hepatocellular carcinoma. Hepatic HBV-DNA correlated with disease activity (P < .02) and the correlation was highly significant with intralobular activity (P < .001). Patients in the early viral replicative phase of infection had higher levels of cytoplasmic and nuclear HBV-DNA compared with the late viral nonreplicative phase. Cytoplasmic and nuclear HBV-DNA correlated with hepatic expression of HBcAg and HBsAg (P < .05 in both cases), but not with HBeAg. These data indicate that hepatic expression of HBV-DNA follows the natural history of chronic HBV infection and is associated with active liver disease.

Adolescent↗
PubMed1996

Prevalence of metronidazole resistant Helicobacter pylori strains among Chinese peptic ulcer disease patients and normal controls in Hong Kong.

BACKGROUND: A study was conducted to evaluate the prevalence of metronidazole resistant Helicobacter pylori strains among the Chinese in Hong Kong. The efficacy of the triple therapy that contains metronidazole as one of the anti-microbial agents in eradication of the metronidazole susceptible and the metronidazole resistant strains was also assessed. METHODS: Culture for H pylori was attempted from antral biopsy specimens of 70 peptic ulcer and 51 control subjects. Successfully cultured H pylori strains were tested for metronidazole susceptibility. Twenty six peptic ulcer disease subjects who had received a course of triple therapy were also reassessed four to six weeks later for successful eradication of H pylori infection. RESULTS AND CONCLUSIONS: H pylori was successfully cultured from antral biopsy specimens in 69 of 80 (86%) of the infected subjects. The overall metronidazole resistance rate was 53.5% (37 of 69). There was a significantly higher metronidazole resistance rate among H pylori isolates from the asymptomatic controls (20 of 25) than the peptic ulcer disease subjects (17 of 44) (p = 0.0007). Twenty three of 32 (73%) women and 14 of 37 (38%) men harboured the metronidazole resistant strains. There was no sex or age difference as far as the prevalence of metronidazole resistant strains were concerned within each study group. Pre-treatment metronidazole susceptible H pylori were significantly more likely to respond to the triple therapy used than those with the metronidazole resistant ones (14 of 15 v five of 10) (p = 0.021).

Anti-Ulcer Agents↗
PubMed1996

Recurrent infection of Legionella pneumonia: a case report.

A 75-year-old male veteran presented with bilateral pneumonia upon admission. He had an episode of Legionnaires' disease in 1991 with complete treatment of erythromycin 500 mg orally every six hours for three weeks. After admission, recurrence of Legionnaires' disease was suspected due to increased serum Legionella antibody (1:128) and strong positive sputum Legionella antigen. Erythromycin and other parental antibiotics were administered, but respiratory failure developed promptly, followed by multiple organ failure syndrome that involved the liver, lung, bone marrow and kidney. He died 42 days after admission. We reviewed seven cases that had been reported and found recurrence of Legionella pneumonia possible after a successful treatment, especially for immunocompromised hosts. Early empirical therapy with erythromycin is recommended.

Aged↗
PubMed1996

Classification of hepatocellular carcinoma according to hepatocellular and biliary differentiation markers. Clinical and biological implications.

Hepatocellular carcinoma (HCC) is a heterogeneous disease. HCC derived from different stages of cellular differentiation may have different clinical and pathobiological behavior. To test the hypothesis that HCC can be classified into two types based on its phenotypic markers (hepatocellular and biliary differentiation), liver tissues from 290 Chinese patients with HCC were studied. Expression of hepatocytic differentiation marker (HEP-PAR-reactive antigen), biliary differentiation markers (AE1-AE3, cytokeratin-19), proliferation markers (Ki-67, proliferating cell nuclear antigen), alpha-fetoprotein, p53, and transforming growth factor-alpha in the tumor tissue were assessed by immunohistochemistry. Hepatocytic differentiation marker was detected in 99.7% and biliary differentiation markers were detected in 29.3% of these tumors. Clinically, no patient with HCC with biliary markers survived for more than 27 weeks compared with a 22.6% survival rate in patients with HCC negative for biliary markers. HCCs positive for the biliary differentiation markers showed features of more aggressive disease in terms of poorer cellular differentiation (P < 0.001) and high-level expression of proliferation markers (Ki-67, P < 0.001; proliferating cell nuclear antigen, P = 0.0114) compared with HCCs without biliary markers. HCCs with biliary markers also had a higher level of expression of alpha-fetoprotein (P < 0.001) and p53 (P = 0.0077). Classification of HCCs based on its phenotypic (differentiation) markers has both clinical and pathobiological implications.

Adult↗
PubMed1996

Malignant lymphoma presenting as tracheal tumor: a case report.

A 66-year-old male presented with dyspnea and cough for 1 month. Fiberoptic bronchoscopy disclosed a huge tumor over the posterior wall of the trachea 1 cm below the vocal cord and biopsy pathology was diffuse, small cleaved lymphoma. Primary malignant lymphoma of the trachea is extremely rare. Its clinical course varies widely, and has no accepted standard of management. We describe herein the whole clinical course of this patient, which is not similar to previous reports. The relation of primary tracheal lymphoma to mucosa-associated lymphoid tissue (MALT) is also discussed.

Aged↗
PubMed1995

Clinicopathological features of hepatitis C virus antibody negative fatal chronic hepatitis C after renal transplantation.

Clinical course and serial liver histology of a patient who developed fatal chronic active hepatitis C after renal transplantation are presented. This patient developed persistently deranged liver biochemistry 3 months after transplantation, despite normal liver enzyme values during the preceding 3 years on hemodialysis. In addition to increased parenchymal enzyme concentrations, the levels of ductal enzymes were also markedly elevated, with peak levels of alanine aminotransferase and gamma-glutamyl transpeptidase 7 and 100 times, respectively, the normal upper limit. The patient was persistently seronegative for hepatitis C virus (HCV) antibodies, but positive for HCV RNA. Treatment with alpha-interferon for 6 months, initiated after the development of early cirrhosis, resulted in no improvement, and the patient died from liver failure 36 months after renal transplantation. Serial liver histology, examined four times from 11 months to 36 months after transplantation, showed progressive deterioration from chronic active hepatitis to cirrhosis. This patient illustrates the uncommon complication of rapidly progressive and ultimately fatal liver disease due to HCV infection after renal transplantation. Early recognition with anti-HCV and HCV RNA assays as well as histologic assessment are crucial for the identification of patients with a poor prognosis who might benefit from therapeutic intervention before irreversible liver damage.

Adult↗
PubMed1995

[The changes of central and peripheral nerve conduction and the effect of thyroxine replacement in thyroidectomized rats].

The aim of this study is to make serial BAEPs and PNCS in hypothyroid rats in order to provide objective and quantitative methods of detecting dysfunction of the central and peripheral nervous system in hypothyroid status and elucidating the relationship between the recovery potential and the duration of hypothyroid status. Thyroidectomy was performed in eighteen naive 5-month-old Sprague-Dawley rats in order to induce hypothyroid status, which was confirmed by RIA study 1-2 months after the surgery. Initial BAEP and PNCS were performed in two groups of the hypothyroid animals 1 and 3 months after thyroidectomy. Following the initial examination, thyroxin replacement therapy was given to each hypothyroid group, and then followed by BAEPs and PNCS at two month intervals, up to twice normal studies or six months after the initiation of therapy. In the BAEP study, the prolonged I-V inter-peak latency was the most consistent abnormal finding in all hypothyroid rats. Delayed peak latencies as well as prolonged I-III and III-V inter-peak intervals occurred when the hypothyroid status was longer than one month. We noted that the longer the hypothyroid status, the more severe the central conduction dysfunction. Nonetheless, these abnormalities always returned to normal after the replacement therapy if the hypothyroid state was shorter than 3 months in duration. For the PNCS study, all groups of thyroidectomized rats showed the normal results. We think the peripheral nervous system of rats may be more resistant to damage by hypothyroidism than the central nervous system.

Animals↗