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Biomedical subjects

N Leung

Publications and source records attributed to N Leung.

36 records · Page 2Linked to original sources
PubMed1997

'Hepatoma-specific' alphafetoprotein may permit preclinical diagnosis of malignant change in patients with chronic liver disease.

The only hope for effective treatment of hepatocellular carcinoma (HCC or 'hepatoma') lies in early diagnosis. Measurement of the serum alphafetoprotein (AFP) level is potentially a useful screening test. When grossly raised, it is almost diagnostic of HCC. However, modestly elevated levels may also arise in patients with benign chronic liver disease, and this markedly decreases the test's specificity and hence its clinical value. In 582 consecutive attendees at an outpatient clinic for people with chronic liver disease, a single blood sample was taken for analysis of 'total' AFP and the 'hepatoma-specific' AFP isoform. Using ultrasonography as the primary screening method, patients with AFP levels > or = 50 ng ml-1 were followed up throughout the study or until HCC was diagnosed on the basis of conventionally defined criteria. On entry into the study, 53 patients had an AFP concentration > = or 50 ng ml-1 and the 'hepatoma-specific' AFP isoform was detected in 26 of these. During an 18-month follow-up period, a diagnosis of HCC was established by conventional methods in 19 (17 'definite' and two 'probable') of these 26 patients. In only two cases was there ultrasound evidence of tumour development at the time AFP was first found to be elevated; in the remainder a diagnosis of HCC, based on ultrasound screening, was established at a median time of 3.6 months (range 1-18 months) after entry into the study. Among those 27 without the 'hepatoma-specific' isoform, one developed a 'definite' HCC and two developed 'probable' tumours. With the application of 'hepatoma-specific' AFP, the positive predictive value of the test was 73.1%, compared with only 41.5% using the conventional 'total' AFP test. Application of this test for the 'hepatoma-specific' AFP markedly increases the positive predictive value of AFP and, in some cases, permits the presence of tumour to be inferred before it could be detected by routine ultrasound examination.

Carcinoma, Hepatocellular↗
PubMed1996

Isoelectric focusing of alphafetoprotein in patients with hepatocellular carcinoma--frequency of specific banding patterns at non-diagnostic serum levels.

Serum levels of alphafetoprotein are raised in 60-80% of patients with hepatocellular carcinoma. Although widely used as a serum marker, frequent false-positive results in patients with benign liver disease, result in poor specificity. This occurs particularly when levels of alphafetoprotein fall between 50-500 ng ml-1, the so-called 'grey area'. Recent reports suggest that isoelectric focusing of alphafetoprotein demonstrates certain bands that are more specific for hepatocellular carcinoma. Our aim was to determine whether the apparent specificity of this new approach is gained at the expense of decreased sensitivity. Sera from 110 patients with a 'non-diagnostic' serum alphafetoprotein level (50-500 ng ml-1) were examined by isoelectric focusing and quantified by densitometric scanning. Ten patients with chronic liver disease and a raised serum alphafetoprotein level (50-500 ng ml-1), but with no evidence of hepatocellular carcinoma, were also studied. Isoelectric focusing revealed characteristic hepatocellular carcinoma bands (bands +II and +III) in 96% patients overall, and 100% of those with levels of total alphafetoprotein greater than 100 ng ml-1. No such bands were seen among ten subjects with cirrhosis but without hepatocellular carcinoma. Bands that are characteristic of hepatocellular carcinoma (bands +II or +III) are seen in the great majority of hepatocellular carcinoma patients; their absence makes a diagnosis of hepatocellular carcinoma extremely unlikely.

Carcinoma, Hepatocellular↗
PubMed1995

Obstructive jaundice secondary to hepatocellular carcinoma.

This prospective study aimed to identify different groups of patients with the rare pathology of biliary obstruction caused by hepatocellular carcinoma (HCC). Patients were evaluated with blood tests, chest radiography, ultrasound of the liver and endoscopic retrograde cholangiopancreatography/percutaneous transhepatic cholangiography. Patients who were potentially operable were further assessed with selective hepatic angiography and computed tomography (CT). Of the 38 patients with obstructive jaundice secondary to HCC, the levels of obstruction were extrahepatic in 19 patients and intrahepatic in 19 patients. The clinical presentations and blood biochemistry were similar in these two groups of patients. "Curative' resection was significantly more common in extrahepatic obstruction (8/19) than in intrahepatic obstruction (0/19) (chi 2 with Yates correction P = 0.001). All non-resectable tumours, except in four patients with terminally ill disease, were palliated with stents. Survival in patients who had "curative' liver resection was significantly better than in those who had no resection (median survival 25.3 vs. 2.1 months, log-rank test P = 0.004). Patients with extrahepatic biliary obstruction secondary to HCC had a better chance of being treated by liver resection, which resulted in a significantly improved survival rate compared to patients with intrahepatic obstruction.

Adult↗
PubMed1995

Acute clonorchiasis.

A 42-year-old Chinese woman developed 3 weeks of swinging fever, rash, malaise, and discomfort at the right upper quadrant of the abdomen. Acute Clonorchis sinensis infection eventually became evident and the patient responded to praziquantel. Although acute infestation is usually asymptomatic, occasional cases suffer severe symptoms and present difficulties in clinical diagnosis. Clonorchiasis is endemic in South East Asia. With the increasing popularity of travel to these countries and the global migration of Asians, physicians need to be aware of the condition. Treatment with praziquantel is effective and prevents the serious sequelae of chronic infection.

Acute Disease↗
PubMed1994

Cytoreductive surgery for hepatocellular carcinoma.

A prospective study was conducted on 26 patients for cytoreductive surgery of inoperable hepatocellular carcinoma. These patients underwent cytoreduction with liver resection, cryosurgery, microwave tissue coagulation and/or absolute alcohol injection. In-hospital mortality was 7.7%. The symptomatic relief and quality of survival were excellent. The median survival of patients after cytoreduction was 10.0 months and the survival was much better than those of 26 patients matched by sex, age, tumour size, Child-Pugh grading and Karnofsky scores who received systemic chemotherapy during the same period of the study (log rank test, P = 0.0001). There was no statistical difference between the survival curves of those patients who received (19 patients) and those who did not receive (7 patients) additional treatment by chemotherapy or selective internal radiation therapy after cytoreduction. This suggests that the gained survival benefit could have been derived mainly from the cytoreductive surgery rather than the additional treatments.

Adolescent↗
PubMed1994

Selective internal radiation therapy with intra-arterial iodine-131-Lipiodol in inoperable hepatocellular carcinoma.

UNLABELLED: From August 1990 to June 1993, 26 patients with inoperable hepatocellular carcinoma were treated with intra-arterial iodine-131-Lipiodol (131I-L). METHODS: Iodine-131-Lipiodol was given through either an implantable arterial port (9 patients) or during hepatic angiography (17 patients). All 26 patients had multiple lesions, 3 had involved resection margin after surgical resection and 1 had diffuse infiltrative lesions. The median size of the largest tumor among 22 patients with a measurable lesion was 4.5 cm (2-9.5 cm). The end points are tumor response in terms of tumor size, change in serum alpha-fetoprotein level, toxicity of treatment and overall survival. RESULTS: Twenty-three patients received a single treatment of 1.11-2.22 GBq (30-60 mCi)131I-L. Three patients received 2.22-4.44 GBq (60-120 mCi)131I-L in three fractions. Considering both radiological regression and reduction in serum alpha-fetoprotein level as objective response criteria, the overall response rate was 52% (13 out of 25 patients with evaluable disease). Ten out of 15 patients who had raised alpha-fetoprotein levels had more than 50% reduction and 8 patients had more than 90% reduction in alpha-fetoprotein level. Since analysis, 19 patients have died and 7 remain alive, giving a minimum median survival of 6 mo (range 1.2-16.6 mo), with 4 surviving more than 1 yr calculated from the day of treatment. There was only one patient who had late deterioration of liver function compatible with radiation hepatitis. There was no bone marrow toxicity documented in any patients. CONCLUSION: Treatment with intra-arterial 131I-L was well tolerated in patients with inoperable hepatocellular carcinoma and produced an objective response of 52% with median survival of 6 mo. A fractionated dose of 131I-L was feasible and the radiation dose could be escalated safely.

Carcinoma, Hepatocellular↗
PubMed1993

Phase II study of high-dose ifosfamide in hepatocellular carcinoma.

A phase II study of high-dose ifosfamide in hepatocellular carcinoma was conducted among 17 Chinese patients. The dose of ifosfamide used was 2.5 g/m2 daily given as a continuous infusion for 5 days. In all, 15 patients were evaluable for tumour response. There was no complete or partial responder. The treatment was well tolerated. The most frequent toxicity was alopecia, which occurred in 11 patients, and 5 patients developed mild haematological toxicity. There was no evidence of liver or bladder toxicity. Overall, 14 patients were evaluable for survival. The median survival was 92 days (range, 30-568 days). We conclude that high-dose ifosfamide is well tolerated but ineffective in hepatocellular carcinoma in Chinese patients.

Adult↗
PubMed1992

Treatment of inoperable hepatocellular carcinoma by intra-arterial lipiodol and 4'-epidoxorubicin.

A total of 30 patients presenting with inoperable hepatocellular carcinoma (HCC) were treated with intrahepatic arterial Lipiodol (5 ml) and 4'-epidoxorubicin (90 mg/m2) once every 4 weeks. The treatment results included no complete response, 2 partial responses, 6 cases of static disease and 19 cases of progressive disease. The median survival was 18.9 weeks. All patients had died by the time of this writing, with survival duration ranging from 4.1 to 87.3 weeks. Toxicities were minimal and included anaemia and alopecia. As compared with a historic control group that had received the same dose of intravenous 4'-epidoxorubicin, the treatment group showed similar response rates but developed fewer toxicities. There was no significant survival benefit over the control group. We concluded that although this form of treatment had comparable activity and produced fewer side effects, it provided no survival benefit over intravenous treatment. The slight prolongation of survival achieved in the treatment group as compared with the control arm might have been due to case selection.

Adult↗
PubMed1990

Regeneration of Freezing-Tolerant Spring Wheat (Triticum aestivum L.) Plants from Cryoselected Callus.

A cryoselection protocol has been developed that provides freezing-tolerant callus that, in turn, can regenerate plants with enhanced cold hardiness. Tolerant calli were selected from spring wheat (Triticum aestivum L.) callus by immersion in liquid nitrogen without addition of cryoprotectants. Less than 15% of the calli survived the initial challenge, whereas 30 to 40% of previously selected calli survived subsequent exposure. Seed progeny from five of 11 regenerant (R2) lines tested exhibited significantly enhanced tolerance to freezing at -12 degrees C. Thus, cryoselection appears to involve at least in part, selection for genetic rather than epigenetic variants. Analysis of one callus line indicated that cryoselection did not induce significant alterations in lipid composition, adenylate energy charge, or freezing point. An increase in the soluble sugar component was detected. Changes were also detected in the protein complement of microsomal membrane and soluble protein extracts of cryoselected callus. In all, seven unique proteins ranging from 79 to 149 kilodaltons were identified. The results demonstrate that freezing tolerant callus can be isolated from a heterogeneous population by cryoselection, and factors that contribute to hardiness at the callus level are biologically stable and can contribute to tolerance at the whole plant level.

Journal Article↗
PubMed1990

Hepatocellular carcinoma in Hong Kong: clinical study on 340 cases.

Three hundred and forty cases of hepatocellular carcinoma in Hong Kong were studied for their clinical features, and various factors were analysed for their prognostic values. The clinical presentation was often vague and rather non-specific and a majority of patients were presented late and often unresectable. The overall median survival was 8 weeks. The Karnofsky performance scale and bilirubin level were the most important prognostic factors. The treated group survived longer than the untreated group.

Adolescent↗
PubMed1988

Effects of acute administration of O,S,S-trimethyl phosphorodithioate on the generation of cellular and humoral immune responses following in vitro stimulation.

The time course of immune modulation induced by acute treatment with O,S,S-trimethyl phosphorodithioate (OSS-TMP), an impurity in technical formulations of malathion, was examined in female C57BL/6 mice. The immune parameters studied included the generation of cytotoxic T lymphocytes (CTL) to alloantigen (H-2 incompatible) and antibody secreting cells to sheep red blood cells, proliferative response to the mitogens, and interleukin-2 (IL-2) production. Acute administration of the non-toxic doses of OSS-TMP, i.e. 20 or 40 mg/kg, led to an elevation in the generation of a CTL response on day 1 or 7, respectively. At 20 mg/kg OSS-TMP, the antibody response was elevated at day 3. However, at a dose of 40 mg/kg OSS-TMP, the antibody response was suppressed at day 1 following treatment. Following acute administration of 60 or 80 mg/kg OSS-TMP, the generation of an antibody and CTL responses was suppressed at all time points tested with 1 exception. One day following treatment at a dose of 60 mg/kg OSS-TMP, there was no change in the CTL response. At day 7 following treatment, the mitogenic responses to lipopolysaccharide and phytohemagglutinin were elevated at all doses of OSS-TMP administered. At this time point, however, the proliferative response to Concanavalin A was elevated in a dose dependent manner. IL-2 production was suppressed following acute administration of 60 or 80 mg/kg OSS-TMP at all time points tested and at all doses tested on day 5 following treatment. These data indicate that OSS-TMP, unlike its congener, O,O,S-trimethyl phosphorothioate, enhances the generation of humoral and cell mediated immune responses of C57BL/6 mice following administration of non-toxic doses.

Animals↗
PubMed1988

The efficacy of high-dose 4'epidoxorubicin in hepatocellular carcinoma.

An open phase II study of high-dose 4'epidoxorubicin (90 mg/m2) was conducted in 33 patients with inoperable hepatocellular carcinoma. Three out of the 33 (9%) patients showed tumour response. The treatment was relatively well tolerated with a moderate degree of haematological toxicity and alopecia, and a mild degree of nausea and vomiting. The overall median survival was 72 days with a prolongation in the patients who showed some response.

Adult↗
PubMed1987

Effects of O,S,S-trimethyl phosphorodithioate on immune function.

The effect of acute administration of 20-80 mg/kg O,S,S-trimethyl phosphorodithioate (OSS-TMP) to C57BL/6 female mice on the murine immune system was determined. The parameters examined to evaluate overt toxicity of the compound included body weight, plasma cholinesterase levels, splenic nucleated cell number and thymic weight and nucleated cell number. Acute administration of 60 or 80 mg/kg OSS-TMP led to a 75 or 63% decrease, respectively, in plasma cholinesterase levels and a decrease in thymic size. At a dose of 80 mg/kg OSS-TMP, the animals also exhibited some lethargy and body weight loss. Below 60 mg/kg OSS-TMP, no overt toxic manifestations were observed. These studies were carried further to determine the effect of OSS-TMP on the generation of in vivo primary and in vitro secondary cellular and humoral immune responses. At nontoxic doses of the compound, i.e. 20 and 40 mg/kg OSS-TMP, the in vivo generation of a primary cytotoxic T lymphocyte (CTL) response to alloantigen was significantly elevated, but this response was unaffected following restimulation of the splenocytes by alloantigen in vitro. The generation of an in vivo primary and in vitro secondary humoral responses to sheep red blood cells (SRBC) was elevated following a single dose of 40 mg/kg OSS-TMP. Administration of toxic doses of OSS-TMP, i.e. 60 and 80 mg/kg, did not alter the ability of splenocytes to generate a primary or secondary CTL response, but suppressed the generation of humoral immune responses. These results differ significantly from those observed in a similar system following acute administration of a structural analog, O,O,S-trimethyl phosphorothioate which was previously shown to have potent immunosuppressive activity at nontoxic doses.

Animals↗
PubMedDate not supplied

Parenteral feeding in a patient with hypertriglyceridemia and increased liver enzyme levels.

OBJECTIVE: To discuss nutritional support in a patient with hypertriglyceridemia and liver dysfunction. METHODS: We describe the hospital course of a critically ill patient with hepatic dysfunction and hypertriglyceridemia who required nutritional support, and we provide an overview of lipid metabolism. RESULTS: A 27-year-old man with hepatic dysfunction and hypertriglyceridemia, who had undergone kidney transplantation 4 months previously, was admitted to the intensive-care unit with upper gastrointestinal bleeding. He was unable to tolerate enteral feeding, and central parenteral nutrition was initiated. Calories from dextrose and fat were limited because of the presence of increased liver enzyme levels and hypertriglyceridemia. A modified regimen of parenteral nutrition was developed for the patient. The short-term reduction of total calories to 75% of the predicted need is safe. CONCLUSION: Nutritional support in patients with liver dysfunction and hypertriglyceridemia is complicated and may require temporary underfeeding because of the need to limit fat and dextrose intake.

Journal Article↗