Search PubMed⌕ Search

Biomedical subjects

C M Lam

Publications and source records attributed to C M Lam.

At least 37 records · Page 2Linked to original sources
PubMed2001

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↗
PubMed2000

Determining resectability for hepatocellular carcinoma: the role of laparoscopy and laparoscopic ultrasonography.

We reviewed our experience with preoperative determination of resectability in patients with hepatocel-lular carcinoma (HCC) over the last 10 years, and evaluated the role of laparoscopy with laparoscopic ultrasonography (USG) since we instituted this technique in June 1994. From January 1989 to December 1998, 500 of 1741 patients with HCC (28.7%) were considered suitable for hepatic resection after preoperative assessment. Significantly more contrast-enhanced computed tomography (CT) scans and fewer percutaneous USGs or hepatic arteriograms were performed in the 299 patients managed since June 1994 (group 2) than in the 201 patients managed before then (group 1). One hundred and ninety-eight patients in group 2 (66%) underwent laparoscopy with laparoscopic USG. Unresectable disease was found in 41 patients in group 1 (20.4%) (all at laparotomy), and in 68 patients in group 2 (22.7%) (16 at laparotomy without laparoscopic examination, 31 at laparoscopic examination alone, and 21 at laparotomy after an inconclusive laparoscopic examination) (P = 0.5). The most common features of unresectable disease were the presence of bilobar intrahepatic metastases and an inadequate liver remnant with cirrhosis. The adoption of the laparoscopic examination after June 1994 improved the overall resection rate at laparotomy in group 2 from 77.3% to 86. 2%, which was better than that in group 1 (79.6%, P = 0.057). For patients with unresectable disease, the operation time and hospital stay were significantly shorter in group 2. The postoperative morbidity and mortality rates were 9.8% and 4.9%, respectively, in group 1, and 5.9% and 2.9% in group 2. There was no operative morbidity in the 31 patients who had unresectable disease detected by the laparoscopic examination alone. Laparoscopy with laparoscopic USG avoids unnecessary laparotomy, and has a definite role in determining resectability in patients with HCC.

Adolescent↗
PubMed2000

Women with placenta praevia and antepartum haemorrhage have a worse outcome than those who do not bleed before delivery.

We set out to assess the maternal and neonatal outcomes of women with placenta praevia and antepartum haemorrhage (APH) between 1991 and 1997, compared with woman with a diagnosed placenta praevia who did not bleed. The demographic data, maternal and perinatal outcomes of 159 women with antepartum haemorrhage were compared with 93 women without antepartum haemorrhage in a retrospective study. Women with antepartum haemorrhage had the diagnosis of placenta praevia confirmed at an earlier gestation. More women with antepartum haemorrhage received antenatal steroids and tocolytic agents, and had emergency caesarean sections. The majority of women with bleeding had an emergency caesarean section for antepartum haemorrhage and more delivered early because of fetal distress. There were more preterm deliveries in women with antepartum haemorrhage. The mean birth weight was 2.69 kg in the women with antepartum haemorrhage and 3.06 kg in those without. More infants in the bleeding group had a low Apgar score at the first minute, respiratory distress syndrome, and admission to special baby care and neonatal intensive care unit. It is concluded that there is an increased risk of premature delivery in women with antepartum haemorrhage and placenta praevia. Aggressive management, tocolysis and cervical cerclage should be explored further to improve the perinatal outcome. Women without antepartum haemorrhage can be managed on an outpatient basis.

Journal Article↗
PubMed2000

Pharmacokinetics of ciprofloxacin in the human eye: a clinical study and population pharmacokinetic analysis.

Ciprofloxacin, a fluoroquinolone antibiotic active against a wide variety of bacteria, is one of a few antibiotics which enters the human eye after oral administration. However, little is known about its pharmacokinetics in the human eye. One or two oral doses of 750 mg of ciprofloxacin (at a 12-h interval) were administered to 48 patients at various times prior to ocular surgery. Clotted blood, aqueous, and vitreous were collected at surgery, and the concentrations of ciprofloxacin were assayed by high-performance liquid chromatography. Our data were combined with those of others, and a population pharmacokinetic analysis was conducted. The concentrations of ciprofloxacin in both aqueous and vitreous were lower than those in serum and peaked at a later time. The pharmacokinetics of ciprofloxacin in aqueous and vitreous were fitted to a compartmental model in which the antibiotic was transferred into and out of the two compartments (aqueous and vitreous) by first-order processes. Population pharmacokinetic software, P-Pharm, was used to calculate the mean half-lives of the loss of ciprofloxacin from aqueous and vitreous, which were 3.5 and 5.3 h, respectively. At steady state, the mean ratios of then concentrations in aqueous and vitreous to the concentrations in serum were 23 and 17%, respectively. After the administration of one or two doses of 750 mg of ciprofloxacin, the concentrations in both aqueous and vitreous in a number of patients were lower than the MICs at which 90% of isolates are inhibited (0.5 mg/liter) for common intraocular bacterial pathogens. Simulations of concentrations in the eye after the administration of higher doses (1,500 mg of ciprofloxacin as a single dose, two doses of 750 mg 2 h apart, and 750 mg every 6 h) indicated that in approximately 20% of patients the concentrations would still be below 0.5 mg/liter. Although oral ciprofloxacin may be a beneficial adjunctive therapy, the use of oral ciprofloxacin alone may not be adequate for perioperative prophylaxis or for treatment of bacterial endophthalmitis.

Adult↗
PubMed1999

Major hepatectomy for hepatocellular carcinoma in patients with an unsatisfactory indocyanine green clearance test.

BACKGROUND: Liver failure is the commonest cause of postoperative death in patients with hepatocellular carcinoma (HCC). With the improvement in operative technique and perioperative care, the limit of hepatic functional reserve may be lowered. The aim of this study was to evaluate the postoperative morbidity, mortality and survival rates in patients with an indocyanine green (ICG) retention value higher than 14 per cent, after major hepatectomy for HCC. METHODS: From January 1994 to December 1997, 117 patients underwent major hepatectomy for HCC; 92 patients had preoperative ICG retention at 15 min lower than 14 per cent (median 8.3 (range 1.6-13.8) per cent), while 25 patients had ICG retention greater than 14 per cent (17.4 (range 14.3-35.3) per cent). Data were collected prospectively and analysed retrospectively. RESULTS: The two groups of patients were similar in terms of age, sex ratio, preoperative platelet count, liver biochemistry, Child-Pugh status and operative procedures performed, but the prothrombin time was significantly longer in the high ICG group. The operative blood loss (1.5 litres), the amount of blood transfused and the number of patients requiring blood transfusion were similar. The postoperative complication rate (41 versus 40 per cent), duration of hospital stay (12 versus 13 days), hospital mortality rate (1 versus 4 per cent) and median survival time (47 versus 45 months) were not significantly different. CONCLUSION: With meticulous surgical technique to decrease intraoperative blood loss and good perioperative care, selected patients with limited hepatic functional reserve can achieve a good immediate postoperative result and a survival rate similar to that of patients with good hepatic functional reserve.

Adolescent↗
PubMed1999

Hepatectomy for hepatocellular carcinoma: toward zero hospital deaths.

OBJECTIVE: The authors report on the surgical techniques and protocol for perioperative care that have yielded a zero hospital mortality rate in 110 consecutive patients undergoing hepatectomy for hepatocellular carcinoma (HCC). The hepatectomy results are analyzed with the aim of further reducing the postoperative morbidity rate. SUMMARY BACKGROUND DATA: In recent years, hepatectomy has been performed with a mortality rate of <10% in patients with HCC, but a zero hospital mortality rate in a large patient series has never been reported. At Queen Mary Hospital, Hong Kong, the surgical techniques and perioperative management in hepatectomy for HCC have evolved yearly into a final standardized protocol that reduced the hospital mortality rate from 28% in 1989 to 0% in 1996 and 1997. METHODS: Surgical techniques were designed to reduce intraoperative blood loss, blood transfusion, and ischemic injury to the liver remnant in hepatectomy. Postoperative care was focused on preservation and promotion of liver function by providing adequate tissue oxygenation and immediate postoperative nutritional support that consisted of branched-chain amino acid-enriched solution, low-dose dextrose, medium-chain triglycerides, and phosphate. The pre-, intra-, and postoperative data were collected prospectively and analyzed each year to assess the influence of the evolving surgical techniques and perioperative care on outcome. RESULTS: Of 330 patients undergoing hepatectomy for HCC, underlying cirrhosis and chronic hepatitis were present in 161 (49%) and 108 (33%) patients, respectively. There were no significant changes in the patient characteristics throughout the 9-year period, but there were significant reductions in intraoperative blood loss and blood transfusion requirements. From 1994 to 1997, the median blood transfusion requirement was 0 ml, and 64% of the patients did not require a blood transfusion. The postoperative morbidity rate remained the same throughout the study period. Complications in the patients operated on during 1996 and 1997 were primarily wound infections; the potentially fatal complications seen in the early years, such as subphrenic sepsis, biliary leakage, and hepatic coma, were absent. By univariate analysis, the volume of blood loss, volume of blood transfusions, and operation time were correlated positively with postoperative morbidity rates in 1996 and 1997. Stepwise logistic regression analysis revealed that the operation time was the only parameter that correlated significantly with the postoperative morbidity rate. CONCLUSION: With appropriate surgical techniques and perioperative management to preserve function of the liver remnant, hepatectomy for HCC can be performed without hospital deaths. To improve surgical outcome further, strategies to reduce the operation time are being investigated.

Adolescent↗
PubMed1998

Hepatic cryosurgery for recurrent hepatocellular carcinoma after hepatectomy: a preliminary report.

BACKGROUND AND OBJECTIVES: The treatment of choice for recurrent hepatocellular carcinoma (HCC) is repeated resection. However, only a small percentage of patients are suitable for further hepatic resection. The aim of this study was to evaluate the surgical risk and operative outcome of hepatic cryosurgery in patients with recurrent HCC. METHODS: A retrospective analysis of patients with recurrent HCC after previous curative hepatectomy treated with cryosurgery. Four patients with recurrent HCC not suitable for further resection were enrolled for cryosurgery, their clinical parameters, the operative details and outcome were studied. RESULTS: No intraoperative or postoperative complications were noted. The duration of operation ranged from 3-5.2 hr and the operative blood loss from 173-1,300 ml. All patients are still alive with survival after cryosurgery ranging from 12-23 mo (25-63 mo after the hepatic resection). Three patients showed evidence of recurrent disease and one patient was disease free. CONCLUSIONS: Hepatic cryosurgery is a safe therapy for patients with unresectable recurrent HCC.

Carcinoma, Hepatocellular↗
PubMed1998

Thermal characteristics of a hepatic cryolesion formed in vitro by a 3-mm implantable cryoprobe.

The objective of the investigation was to characterize the hepatic cryolesion formed with an implantable needle (3 x 100 mm) cryoprobe. This was used to produce cryolesions in isolated porcine liver tissue equilibrated to 37 degrees C in a water bath. The shape, size, and temperature zones within the cryolesion and the effect of single versus repeated freeze-thaw cycles on cryolesion size were studied. The final shape of the cryolesion at 15-20 min freezing was cylindrical and its distal hemispherical end extended 8 mm beyond the tip of the cryoprobe. The rate of increase in maximum diameter was logarithmic and decreased from 4.7 mm/min during the first 5 min to 0.4 mm/min during the fourth 5-min period of freezing. By contrast, the rate of increase in volume was linear and ranged from 9.6 to 7.9 ml/min during the corresponding periods. The volume of the hepatic cryolesion after 20 min of continuous freezing was significantly greater than that of the cryolesion formed with 20 min of cumulative freezing interrupted by a 5-min spontaneous thaw. The ultimate temperatures reached and the cooling rates varied in different zones within the cryolesion depending on distances away from and alongside the cryoprobe. Diameter measurements taken in isolation do not reflect the actual growth rate of the cryolesion. Volume measurements define more accurately the amount of tissue frozen and left in situ. Prolonged freezing beyond 20 min did not increase the diameter of the cryolesion. A single continuous freeze produces a larger cryolesion than two freeze-thaw cycles of the same freezing duration.

Animals↗
PubMed1998

Prolonged survival in selected patients following surgical resection for pulmonary metastasis from hepatocellular carcinoma.

BACKGROUND: Pulmonary metastasis is the commonest site of extrahepatic spread from hepatocellular carcinoma (HCC). The aim of the present study was to evaluate the efficacy of surgical management in patients with solitary pulmonary metastases from HCC. METHODS: This was a retrospective study of patients with HCC admitted for hepatectomy from July 1972 to June 1995. The records of patients who had a pulmonary resection for histologically proven pulmonary recurrence after curative hepatectomy were selected for analysis. RESULTS: In the study interval, 380 patients with HCC underwent hepatectomy. Some 48 patients (12.6 per cent) developed pulmonary metastases documented pathologically or radiologically. Nine (seven men and two women) were suitable for curative pulmonary resection. The median disease-free survival between hepatectomy and appearance of the lung metastasis was 21 months. The median survival after pulmonary resection was 42 months, and the 1-, 2- and 5-year survival rates were 100, 78 and 67 per cent respectively. CONCLUSION: Pulmonary resection for metastases from HCC resulted in long-term survival in these highly selected patients.

Adult↗
PubMed1996

Increased cholecystectomy rate after the introduction of laparoscopic cholecystectomy in Scotland.

This survey determined the effect of the introduction of laparoscopic cholecystectomy on the rates of cholecystectomy (total and laparoscopic) in Scotland. From 1977 to 1990, the Scottish cholecystectomy rate fell by an average of almost 1% per annum. With the advent of laparoscopic cholecystectomy, the total cholecystectomy rate (open and laparoscopic) rose considerably--by 18.7% from 1989-93 (p < 0.05). The largest increase (25%) was observed in the 45-64 years age group but it was also particularly evident (19%) in elderly patients (65-74 years). Subjects were more likely to undergo laparoscopic cholecystectomy than open cholecystectomy if they were young and female. The increased cholecystectomy rate observed merits careful scrutiny and health economic evaluation.

Adolescent↗
PubMed1995

Ultrasonographic characterization of hepatic cryolesions. An ex vivo study.

OBJECTIVE: To determine the physical basis for the ultrasonographic characteristics of the hepatic ice ball produced by cryotherapy and the size correlation between the actual hepatic ice ball and the ultrasonographic cryolesion. DESIGN: Experimental ex vivo study involving controlled freezing with liquid nitrogen recirculating probes of fresh porcine livers immersed in various solutions at ambient temperatures (20.2 degrees C to 22.6 degrees C), together with measurements of the impedance of frozen and unfrozen liver. RESULTS: First, the hyperechoic rim is caused by reflection of 34% of ultrasound waves at the interface between unfrozen and frozen liver as a consequence of an increased acoustic impedance of frozen liver that was calculated to be approximately 3.8 times that of unfrozen liver tissue. The increased acoustic impedance is due to the decrease in elasticity of hepatic tissue as it freezes. Second, the posterior acoustic shadowing is partly due to the attenuation of the incident ultrasound waves by reflection at the interface between unfrozen and frozen liver. It is also dependent on the crystalloid-protein content of hepatic parenchyma, which ensures a homogeneous lesion by preventing "shattering" within the cryolesion. This is in sharp contrast to the ultrasonographic appearance of an ice ball formed in ionized water, in which the hyperechoic rim overlies an area of posterior acoustic enhancement. Third, the correlation of the size between the ultrasonographic cyrolesion and the measured hepatic ice ball approached unity (r = .99), and the two measurements were identical for cryolesions less than 50 mm in diameter. CONCLUSION: Ultrasound is an accurate method for depicting the actual diameter of frozen solid hepatic tissue in cryotherapy for liver tumors, but the present technology does not provide accurate assessments of the volume of frozen tissue.

Animals↗
PubMed1989

Relationship between the delay task and rating scale measures of inattention and hyperactivity.

A group of 187 elementary school children were administered a microcomputer version of the Delay Task (Gordon, 1979) in which responses were reinforced only when they followed the preceding response by at least 6 seconds. They were also rated on the Conners Teacher Rating Scale (CTRS) by their classroom teacher. Performance on the Delay Task was not correlated with any of the CTRS subscales for the overall sample. Sex differences were found in the Conduct, Inattention, and Hyperactivity factors of the CTRS. No sex difference was found for performance on the Delay Task. When performance on the Delay Task was correlated with the four CTRS factors by sex, correlations between the Delay Task and the inattention subscale and hyperactive subscale were significant only for the male subsample. Implications of the findings for assessment of hyperactivity are discussed.

Attention↗
PubMedDate not supplied

Carcinoma of the colon with synchronous hepatic metastasis in a cirrhotic liver harboring a hepatocellular carcinoma.

Tumor metastasis to a cirrhotic liver is rare. It has been suggested that colorectal cancer does not metastasize to the cirrhotic liver. We reported a 65 year-old man, a known carrier of hepatitis B surface antigen, diagnosed to have hepatocellular carcinoma with routine screening. A partial hepatectomy with resection of segments VI and VII was performed. The hepatectomy specimen revealed a 4.5 cm diameter HCC in a cirrhotic liver. Incidentally, 0.8 cm diameter ulcer at the descending colon. Histological examination of the left hemicolectomy specimen showed a moderately differentiated adenocarcinoma.

Adenocarcinoma↗
PubMedDate not supplied

Radiofrequency ablation as a salvage procedure for ruptured hepatocellular carcinoma.

Spontaneous rupture of hepatocellular carcinoma is a distinct presentation causing acute abdomen. Different treatment approaches have been advocated including emergency hepatectomy, initial hemostasis by hepatic artery ligation or transarterial embolization and second-stage hepatectomy. Unrecognized ruptured hepatocellular carcinoma during laparotomy is often encountered in countries where the incidence of hepatocellular carcinoma is low. Radiofrequency ablation is a new localized thermal ablative technique for the treatment of unresectable hepatic tumors including hepatocellular carcinoma. We report a case where radiofrequency ablation was used as a salvage procedure for ruptured hepatocellular carcinoma during emergency laparotomy.

Aged↗