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M Chan

Publications and source records attributed to M Chan.

At least 109 records · Page 6Linked to original sources
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↗
PubMed1994

Acute median nerve dysfunction from wheelchair propulsion: the development of a model and study of the effect of hand protection.

Carpal tunnel syndrome is prevalent among individuals who are wheelchair dependent. Maximal electrophysiologic median nerve dysfunction has been isolated to the proximal part of the carpal tunnel--the site of hand-wheel interface during wheeling. The objective of this study was to determine if measurable median nerve dysfunction (conduction slowing or block) results from a single session of vigorous wheeling and, if so, if protection for the hand with a glove (padded over the region of the carpal tunnel) could minimize the dysfunction. Thirty-five subjects (16 wheelchair dependent; 19 able-bodied) propelled a roller-mounted wheelchair at maximal rate of 2,000 hand strikes. A protective glove was worn on 1 hand only. Immediately before and after the wheeling, hand surface temperatures and bilateral median motor and sensory conductions were performed, and across-carpal tunnel conduction velocity and conduction block were calculated. Another group of 11 able-bodied subjects underwent similar electrodiagnostic testing before and after one half hour of vigorous stationary cycling (no hand trauma). Results were analyzed using a three-way analysis of covariance for repeated measures and demonstrated that (1) significant increases (5.2% to 8.5%) in across carpal tunnel conduction block occurred as a result of wheelchair propulsion but not cycling; (2) the wheeling-induced conduction block was not altered by using a protective glove. This study has demonstrated a model for measuring acute median nerve dysfunction resultant from wheeling but raises doubts regarding the protective effect of glove use on median nerve function.

Adolescent↗
PubMed1994

Measuring lung shunting in hepatocellular carcinoma with intrahepatic-arterial technetium-99m macroaggregated albumin.

UNLABELLED: With increased use of intraarterial administration of chemotherapeutic and radioactive particulate agents, it is necessary to assess agent delivery in the lung. METHODS: Technetium-99m-labeled macroaggregated albumin (99mTc-MAA) delivered through the hepatic artery was used to determine the degree of lung shunting in 125 patients with hepatocellular carcinoma (HCC). RESULTS: The percentage of lung shunting varied among patients and it ranged from less than 1% to 67.2%, with a median of 8.1%. The degree of shunting depended on the vascularity of the tumors but not on the tumor size. The effect of angiotensin II on lung shunting was tested on six patients and there was no significant difference found between those patients who were pre-treated with angiotensin II and those who were not. One patient who underwent a liver resection, had a significant decrease in lung shunting from 28.5% to less than 1% after surgery. CONCLUSION: The lack of effect of angiotensin II together with the almost complete ablation of lung shunting by tumor resection suggested neoplastic blood vessels were responsible for the shunting.

Angiotensin II↗
PubMed1993

Food preferences and food habits of patients with chronic renal failure undergoing dialysis.

OBJECTIVE: To examine and compare the food preferences of patients undergoing maintenance hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) with those of age- and sex-matched controls. DESIGN: We administered two questionnaires, one assessing preferences for 88 food items (according to a nine-point hedonic scale) and the other assessing factors influencing dietary habits. SUBJECTS: Thirty-three patients on HD, 17 patients on CAPD, and 30 control subjects with normal renal function. MAIN OUTCOME MEASURES: The 88 foods were grouped into 14 classes to compare preferences. Taste aversions, food preparation details, and psychological and social determinants of food intake were also compared. STATISTICAL ANALYSIS: The preference ratings of the HD, CAPD, and control groups were compared using analysis of variance. The dietary habits results were examined using a chi 2 analysis. RESULTS: Sweet foods (P = .002), vegetables (P = .003), red meats (P = .010), and fish and poultry (P = .015) were less pleasant for patients on HD than for control subjects. Red meats (P = .019), fish and poultry (P = .032), and eggs (P = .005) were less pleasant for patients on HD than for patients on CAPD. Red meat was the most unpopular food group for all dialysis patients. The most common factor affecting dietary intake was a loss of interest in food and/or cooking. CONCLUSION: We conclude that chronic renal failure influences patients' food preferences and food habits. Knowledge of these preferences will help dietitians plan more adequate and enjoyable diets for such patients.

Adult↗
PubMed1993

Hepatic intra-arterial lipiodol ultrasound guided biopsy in the management of hepatocellular carcinoma.

One hundred and fifty-one consecutive new patients with suspected hepatocellular carcinoma (HCC) were investigated from 1989 to 1990. Ultrasound showed the tumours to be inoperable in 111 patients. Selective hepatic angiography revealed 17 more patients with inoperable HCC. Hepatic intra-arterial lipiodol (HIAL) was injected in the remaining 23 patients. In 16 of them, a clinical decision could be reached basing on the radiological findings. Hepatic intra-arterial lipiodol ultrasound (HIAL/USG) guided biopsy was done in seven patients with suspicious lesions. Histology obtained with this method revealed hyperplastic cirrhotic nodules in four patients (two with suspected HCC and two with suspected secondaries). In another two patients, the suspected lesions were confirmed to be malignant. In the last patient who had received chemotherapy for extensive HCC, HIAL/USG guided biopsy revealed necrotic tissue only. At laparotomy, diffuse infiltrative abnormality was found and repeated biopsy confirmed residual malignancy in the necrotic tumour. We conclude that when there is radiological uncertainty as to the nature and extent of the HCC, HIAL/USG guided biopsy can help the clinician to make important decisions.

Adult↗
PubMed1993

The role of hepatic arterial embolization in the management of ruptured hepatocellular carcinoma.

Fifteen patients with ruptured hepatocellular carcinomas and intraperitoneal bleeding were considered for hepatic arterial embolization. Embolization was attempted in nine patients (60%) with patent or partially patent portal veins. Successful occlusion of the feeding tumour vessels was achieved in eight patients (53%) with six patients (40%) surviving more than 3 months compared to three survivors in the non-embolized group, all of whom had total occluded portal veins. Prognosis depends on the underlying liver function with total serum bilirubin levels of survivors significantly lower than those patients who died (P < 0.01). Embolization was tolerated well in those patients with partial portal vein occlusion. Selective tumour embolization should be the initial treatment of choice in these severely ill patients who have reasonable hepatic function.

Carcinoma, Hepatocellular↗
PubMed1993

Infection by echoviruses 1 and 8 depends on the alpha 2 subunit of human VLA-2.

Anti-VLA-2 antibodies protected HeLa cells from infection by echoviruses 1 and 8 but not from infection by other echovirus serotypes. Echoviruses 1 and 8 bound to and infected nonpermissive hamster cells transfected with the alpha 2 subunit of human VLA-2. These results indicate that the human alpha 2 subunit is critical for infection by echoviruses 1 and 8 but that other echovirus serotypes must bind receptors other than VLA-2.

Animals↗
PubMed1993

Hospital response to psychosocial needs of AIDS inpatients.

Compassionate care for HIV-infected persons requires response to psychosocial needs. With no new external funding, Women's College Hospital, a 270-bed urban teaching hospital, provided effective psychosocial services for HIV-infected inpatients by developing a comprehensive policy, educating staff, organizing existing services into a psychosocial support team to provide crisis intervention, and developing liaisons with community AIDS organizations. A retrospective chart review of epidemiologic and psychosocial patient data was carried out for 59 HIV inpatients (58 men, 1 woman) admitted 1987-89. Of the cohort, 91% indicated homosexual contact as the only risk factor. A psychosocial support team contacted 90% of these inpatients. One third (36%) of the patients designated as next of kin individuals who were not legally or biologically related. Approximately 25%-30% made active arrangements for impending death, e.g. wills and funeral plans. Thirteen patients, 22%, died in hospital, and three, 5%, on first admission. Experience showed that psychosocial interventions that focus on human dignity and quality of life, normally seen as elements of palliative care, are critically important from the earliest stages of HIV disease and should not be reserved only for those who are terminally ill.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Subdural block.

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Adult↗
PubMed1992

Phosphatidylcholine metabolism in ischemic and hypoxic hearts.

The rates of phosphatidylcholine biosynthesis in the isolated hamster hearts under ischemic and hypoxic conditions were examined. Global ischemia was produced by perfusion of the heart with a reduced flow, whereas hypoxia was produced by perfusion with a N2-saturated buffer. A 51% reduction in the biosynthesis of phosphatidylcholine was observed in the ischemic heart. The reduction was caused by a severe decrease in ATP level which resulted in a diminished conversion of choline into phosphocholine. A 22% reduction in the biosynthetic rate of phosphatidylcholine was also detected in the hypoxic heart. The reduction was caused by a diminished level of CTP which resulted in a decreased conversion of phosphocholine to CDP-choline. No compensatory mechanism was triggered during ischemia, but the CTP: phosphocholine cytidylyltransferase activity was enhanced in the hypoxic heart. Our results demonstrate the possible rate-limiting role of choline kinase and reconfirm the regulatory role of the cytidylyltransferase in the biosynthesis of phosphatidylcholine.

Adenosine Triphosphate↗
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↗
PubMed1992

The effect of amino acids on choline uptake and phosphatidylcholine biosynthesis in mammalian hearts.

The uptake of choline in mammalian hearts in the presence of amino acids was examined. Isolated hamster, guinea pig, rat and rabbit hearts were perfused with labeled choline in the presence and absence of amino acids. Neutral amino acids enhanced choline uptake in the hamster heart, but not in the guinea pig, rat and rabbit hearts. Phosphatidylcholine biosynthesis in these hearts was not affected by the presence of amino acids. Choline uptake in the hamster myocytes was also enhanced by neutral amino acid. The enhancement of choline uptake suggests a direct interaction between the amino acid and the transport of choline into the myocardiac cells. The different responses in choline uptake to neutral amino acids indicate that the regulation of choline uptake in the hearts may be different between mammalian species.

Amino Acids↗
PubMed1991

Expression of inducible membrane-anchored insulin receptor kinase enhances deoxyglucose uptake.

We have transfected mouse L cells with a recombinant membrane-anchored insulin receptor kinase (called MARK), under the transcriptional control of a glucocorticoid-responsive element. The transfected construct includes only 15 extracellular residues, with the transmembrane and intracellular kinase domains of the human insulin receptor cDNA (amino acid residues -27 to 12 and 915 to 1343 (see Ullrich, A., Bell, J. R., Chen, E. Y., Herrera, R., Petruzzelli, L. M., Dull, T. J., Gray, A., Coussens, L., Liao, Y. C., Tsubokawa, M., Mason, A., Seeburg, P. H., Grunfeld, C., Rosen, O. M., and Ramachandran, J. (1985) Nature 313, 756-761), predicted Mr = 56,000 with signal sequence, 53,000 without). Transfected cells which are exposed to dexamethasone express two proteins of approximate Mr = 54,000 which (a) react with anti-peptide antisera raised to human insulin receptor sequences, (b) localize to the membrane fraction, and (c) possess ligand (insulin)-independent tyrosine kinase activity. In extracts of steroid-treated MARK cells, a phosphotyrosine-containing protein of Mr = 185,000 is detected, which corresponds in size to a known endogenous substrate for the insulin receptor. Control studies were performed with the nontransfected parent line, and with L cells transfected with an inactive human insulin receptor protein tyrosine kinase. Dexamethasone induced no change in the proteins detected by an anti-phosphotyrosine antibody in the two control lines. In studies of deoxyglucose uptake, dexamethasone stimulated increase in deoxyglucose uptake 2-fold in the MARK cells compared to the same cells studied in the absence of dexamethasone. Dexamethasone had no effect in the control cell lines. These studies demonstrate that a membrane-anchored insulin receptor kinase, devoid of virtually the entire extracellular domain of the insulin receptor, is sufficient to induce enhanced deoxyglucose uptake.

Animals↗
PubMed1990

Sonographic diagnosis of portal vein invasion in patients with hepatocellular carcinoma: comparison with arterial portography.

The results of sonographic assessment of the main portal vein were compared with arterial portography in 65 patients with documented hepatocellular carcinoma. When compared with fully-diagnostic angiograms, obtained in 54 patients, sensitivity of ultrasound was 64% with a specificity of 98%. We conclude that ultrasound is a valuable first-line method of detecting portal vein invasion in the preoperative assessment of patients with hepatocellular carcinoma.

Adolescent↗
PubMed1990

Characterization of the high and low affinity components of the renal Ca2(+)-Mg2+ ATPase.

The purpose of this study was to characterize the interrelationship between free calcium (Ca2+) and magnesium (Mg2+) in the Ca2+ ATPase enzyme cycle of kidney membranes. Experiments were performed with basolateral membranes from rat renal cortex and microdissected proximal and distal tubules from mice. Results were similar in the three types of preparations. We first investigated the effect of ATP concentration on Ca2(+)- and Mg2(+)-dependent ATP hydrolysis. With 0.2 microM Ca2+, the enzyme activity, as a function of ATP concentration, showed two saturable components: a high affinity component with a Km of 33 microM ATP and a low affinity component with a Km of 0.63 mM ATP. These components may represent either two distinct sites of ATP binding or two forms of the same site. For the sake of simplicity, it was assumed that the two components correspond to a high affinity and a low affinity substrate site. At the high affinity site (ATP = 50 microM), the Ca2+ dependence of ATP hydrolysis followed a single Michaelis-Menten kinetics with Km for Ca2+ of 0.08 microM. The addition of 1 mM Mg2+ resulted in a relatively constant increase in ATP hydrolysis at all Ca2+ concentrations, indicating that the effects of the two cations were additive. With high ATP concentration (ATP = 3 mM), Ca2+ also induced an ATP hydrolysis according to a saturable process, with a Km for Ca2+ of 0.2 microM. In contrast with what occurred with low concentrations of ATP, addition of millimolar Mg2+ completely curtailed the sensitivity of the enzyme to Ca2+.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗
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↗
PubMed1990

Twelve years' experience of computer-aided diagnosis in a district general hospital.

This paper describes experience in a modern district general hospital with a small desktop system for computer-aided diagnosis of acute abdominal pain, over a 12-year period involving 5512 cases. When compared with a baseline year (1973) in which unaided performance was monitored, during an initial study period (1974-76) the diagnostic accuracy of junior staff rose by between 10 and 15%. This higher performance level was then maintained for a decade (1976-86) despite changes in staff. The perforation rate among appendicitis cases fell from 27% to 12.5%, accompanied by a smaller fall in negative laparotomy rates. The saving in surgical bednights devoted to acute abdominal pain was approximately 15%, and the notional cost of resources saved during the first 6 years of operation was 120,000 pounds. Other hospitals have shown--in the short term--benefits similar to those obtained at Airedale District General Hospital. The long-term benefits of the system at Airedale reinforce the conclusions of the earlier short-term trials that a comparable system should probably be offered to all DGHs in the UK, not as an exercise in 'artificial intelligence' but as an effective continuing stimulus to good clinical practice.

Abdominal Pain↗