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Biomedical subjects

S T Fan

Publications and source records attributed to S T Fan.

At least 37 records · Page 2Linked to original sources
PubMed2004

Influence of laparoscopy on postoperative recurrence and survival in patients with ruptured hepatocellular carcinoma undergoing hepatic resection.

BACKGROUND: Use of laparoscopy in patients with gastrointestinal cancer has been associated with port-site and peritoneal tumour metastases. The effect of laparoscopy on tumour recurrence and long-term survival in patients undergoing resection of ruptured hepatocellular carcinoma (HCC) remains unknown. METHODS: Between June 1994 and December 2001, 59 patients with ruptured HCC underwent surgical exploration with a view to hepatic resection. Laparoscopy with laparoscopic ultrasonography was performed in 33 patients; the other 26 patients underwent exploratory laparotomy without laparoscopy. Perioperative and long-term outcomes were compared between the two groups. RESULTS: Exploratory laparotomy was avoided in 12 of 13 patients with irresectable HCC who had a laparoscopy. The hospital stay of these 12 patients was significantly shorter than that of eight patients found to have irresectable HCC at exploratory laparotomy (median 11 versus 15 days; P = 0.043). Twenty patients had a laparoscopy followed by open resection of HCC, whereas 18 patients underwent laparotomy and resection without laparoscopy. There were no significant differences in disease-free (16 versus 19 per cent; P = 0.525) and overall (32 versus 48 per cent; P = 0.176) survival at 3 years between the two groups. The tumour recurrence pattern was similar between the two groups, and there were no port-site or wound metastases. CONCLUSION: Use of diagnostic laparoscopy in patients with ruptured HCC helps avoid unnecessary exploratory laparotomy. The present data suggest that laparoscopy does not have an adverse effect on tumour recurrence or survival in patients who undergo resection.

Adult↗
PubMed2004

Delayed portal vein thrombosis after experimental radiofrequency ablation near the main portal vein.

BACKGROUND: Portal venous blood flow may protect adjacent tumour cells from thermal destruction with radiofrequency ablation (RFA). This study aimed to investigate the local effect of RFA on the main portal vein branch, and the completeness of cellular ablation in its vicinity, with or without a Pringle manoeuvre using a porcine model. METHODS: This was an in vivo study on 23 domestic pigs. RFA using a cooled-tip electrode was performed 5 mm from the left main portal vein branch under ultrasonographic guidance for 12 min with (n = 10) or without (n = 10) a Pringle manoeuvre. Ten pigs were killed 4 h after the procedure to study the early effects of RFA and ten others were killed 1 week later to determine any delayed effect. As a control, sham operations with a Pringle manoeuvre for 12 min were performed on three pigs. The flow velocity changes of portal vein and hepatic artery were measured using Doppler ultrasonography, and the completeness of cellular ablation around the portal vein was assessed qualitatively by histochemical staining and quantitatively by measuring intracellular levels of adenosine 5'-triphosphate (ATP). RESULTS: In the absence of the Pringle manoeuvre, there was no significant change in mean(s.d.) portal vein flow velocity before RFA (20.0(3.5) cm/s) and at 4 h (18.5(2.5) cm/s) (P = 0.210) and 1 week (19.5(2.2) cm/s) (P = 0.500) after the procedure. Gross and histological examination of the portal vein branches showed no damage without the Pringle manoeuvre. In all pigs that underwent RFA with a Pringle manoeuvre, the portal vein was occluded 1 week after the operation; histological examination of the affected portal vein showed severe thermal injury and associated venous thrombosis. The local effect of RFA on the hepatic artery was similar. With intact portal blood flow during RFA, complete ablation of liver tissue around the pedicle was demonstrated by histochemical staining and measurement of the intracellular ATP concentration. CONCLUSION: RFA was safe when applied close to the main portal vein branch without a Pringle manoeuvre, with complete cellular destruction. Use of the Pringle manoeuvre resulted in delayed portal vein and hepatic artery thrombosis and injury to the hepatic artery and bile duct.

Animals↗
PubMed2004

Potential role for platelet apheresis for post-liver transplant thrombocytosis complicating portal vein thrombosis.

Except for patients with underlying myeloproliferative diseases (MPD), thrombocytosis is rarely encountered in cirrhotic patients after liver transplantation. Although the long-term control of primary thrombocytosis is important for the prevention of graft thrombosis in MPD patients, the threshold for intervention and best mode for the control of persistent reactive thrombocytosis after liver transplantation is unclear. We present two patients with extreme reactive thrombocytosis (over 1,000 x 10(9)/l) due to intra-abdominal sepsis after liver transplantation. Furthermore, both patients suffered from bleeding problems as well as ongoing venous thrombosis of the graft. Rapid control of the platelet count was achieved using platelet apheresis. The use of cell separation procedures may be a relatively rapid, reversible, and reasonably safe way to control platelet counts peri-operatively in liver transplant recipients.

Adult↗
PubMed2003

Identification of liver-intestine cadherin in hepatocellular carcinoma--a potential disease marker.

Liver-intestine cadherin (LI-cad) is a non-classical cadherin, which is expressed during intestinal development, but absent in normal liver tissue. Our earlier investigation has detected overexpression of LI-cad in gastric adenocarcinoma and indicated its association with lymph node metastasis. Herein, we found in RT-PCR and TaqMan Q-PCR that LI-cad was identified in HCC cell lines, HuH-7, Hep-3B, and PLC/PRF/5, but not in MIHA and HepG2 non-tumorigenic cells. Immunofluorescence cytochemistry assay revealed that the LI-cad was predominantly expressed in cytoplasm of HCC cells, contrary to that of E-cad immunostain at the plasma membrane region. By testing against 18 pairs of HCC and adjacent non-tumor tissues, 13 cases (72.2%) showed over expression of LI-cad in HCC tissues, 2 cases (11.1%) were similar, and 3 cases did not yield detectable signal. None of the 6 normal liver specimens tested was positive with LI-cad. Taken together, LI-cad could be a potential disease marker for HCC.

Aged↗
PubMed2003

Clinicopathologic significance of genetic alterations in hepatocellular carcinoma.

Hepatocarcinogenesis may involve multiple mutations with distinctive pathogenetic and clinicopathologic significance. To test this hypothesis, 68 cases of hepatocellular carcinoma (HCC) were studied prospectively for genetic-clinicopathologic correlation. Ten pathologic characteristics were evaluated. TP53 (alias p53) gene mutation was studied by a polymerase chain reaction (PCR)-single-strand conformation polymorphism-sequencing; CDKN2B (alias p15) and CDKN2A (alias p16) gene methylation by methylation-specific PCR; and genetic imbalances by comparative genomic hybridization (CGH). TP53 gene mutations occurred in 25% of cases, more than half being codon 249 G to T transversion. Methylation of CDKN2A was frequent (61.7%); of CDKN2B, rare (5.9%). The CGH analysis showed a median of nine aberrations per case, with amplifications more frequent than deletions. Isochromosomes might be involved in about 25% of cases. Amplifications of 1q and 8q were most frequent. Clinicopathologic correlations showed that CDKN2A methylation was significantly associated with tumors arising in cirrhotic livers; amplifications of 17q was significant in multiple parameters of tumor invasiveness (size, venous invasion, poor cellular differentiation, microsatellite formation); other amplifications (1q, 6p, 10p, and 20p) were also significant in tumor invasion; and deletions (at 1p, 11q, 4q, and 14q) were significant in tumor growth. Consistent patterns of genetic alterations were defined in HCC, which might represent distinctive pathways in hepatocarcinogenesis.

Adolescent↗
PubMed2003

Red blood cell alloantibodies and liver transplantation in Chinese patients.

BACKGROUND: Red blood cell (RBC) alloantibodies are present in up to 14% of white recipients of liver transplants and can cause severe delayed hemolysis. METHODS: A retrospective survey showed 17 cases (8.8%) of RBC alloantibodies in 192 consecutive Chinese recipients of liver transplants compared with a background hospital incidence of 3.7%. RESULTS: The spectrum of RBC alloantibodies in Chinese patients was different than in white patients, with no anti-D or anti-K antibodies but a significant incidence of anti-Mi (29%) antibodies. There was a significantly increased incidence of transfusions in RBC alloantibody positive cases. Delayed hemolysis also resulted in higher day-7 bilirubin levels. A total of 7 to 86 antigen-positive units were issued in five RBC alloantibody cases, including three early deaths. Seven cases in the RBC alloantibody negative group, but none in the positive group, were salvaged by regraft. CONCLUSIONS: Blood banks servicing transplant centers should be aware of ethnic patterns in RBC alloantibodies. Delayed hemolysis may jeopardize patient survival as the result of difficult postoperative stabilization, especially in cases requiring massive transfusion.

ABO Blood-Group System↗
PubMed2003

Red blood cell alloantibodies and liver transplantation in Chinese patients.

Red blood cell (RBC) alloantibodies are present in up to 14% of white recipients of liver transplants and can cause severe delayed hemolysis. A retrospective survey showed 17 cases (8.8%) of RBC alloantibodies in 192 consecutive Chinese recipients of liver transplants, compared with a 3.7% background hospital incidence. The spectrum of RBC alloantibodies was different from that in white recipients, with no anti-D or anti-K antibodies but with a significant incidence of anti-Mi (29%) antibodies. There was significantly increased transfusion in RBC alloantibody positive cases. Delayed hemolysis also resulted in higher day-7 bilirubin levels. A total of 7 to 86 antigen-positive units were issued in five RBC alloantibody cases, including three early deaths. Seven cases in the RBC alloantibody negative group, but none in the positive group, were salvaged by regraft. Blood banks servicing transplant centers should be aware of ethnic patterns in RBC alloantibodies. Delayed hemolysis may jeopardize patient survival as a result of difficult postoperative stabilization, especially in cases requiring massive transfusion.

ABO Blood-Group System↗
PubMed2003

Right lobe living donor liver transplantation with or without venovenous bypass.

BACKGROUND: Venovenous bypass was considered necessary to maintain haemodynamic stability and avoid splanchnic and retroperitoneal congestion during the anhepatic phase of liver transplantation. It was essential for right lobe living donor liver transplantation (LDLT) in which the inferior vena cava needed to be cross-clamped to construct wide and short hepatic vein anastomoses. However, many complications related to venovenous bypass have been reported. This study aimed to determine whether venovenous bypass was necessary for right lobe LDLT. METHODS: Between June 1996 and June 2001, 72 patients underwent right lobe LDLT. The outcomes for the first 29 patients who had venovenous bypass during the operation were compared with those of the remaining 43 patients who did not have venovenous bypass. In patients without bypass, blood pressure was maintained during the anhepatic phase by boluses of fluid infusion and vasopressors. RESULTS: Compared with patients undergoing operation without venovenous bypass, patients who had venovenous bypass required significantly more blood, fresh frozen plasma and platelet infusion, and had a lower body temperature; their postoperative hepatic and renal function in the first week was worse than that in patients who did not have a bypass. The time to tracheal extubation was longer and the incidence of reintubation for ventilatory support was higher with venovenous bypass. Six of the 29 patients with venovenous bypass died in hospital, compared with two of the 43 patients without a bypass (P = 0.05). By multivariate analysis, the lowest body temperature during the transplant operation was the most significant factor that determined hospital death. CONCLUSION: Venovenous bypass is not necessary and is probably harmful to patients undergoing right lobe LDLT, and should therefore be avoided.

Adolescent↗
PubMed2003

Factors predictive of 5-year survival after transarterial chemoembolization for inoperable hepatocellular carcinoma.

BACKGROUND: Transarterial chemoembolization (TACE) is widely used for unresectable hepatocellular carcinoma (HCC), but the long-term survival benefit remains unclear. METHODS: Pretreatment variables were analysed for factors predictive of actual 5-year survival from a prospective database of patients with inoperable HCC treated by TACE between 1989 and 1996. RESULTS: Complete 5-year follow-up (median 91 months) was obtained for 320 patients who underwent a median of 4 (range 1-41) TACEs. Median tumour size was 9 (range 1-28) cm. There were 25 5-year survivors (8 per cent), including eight with tumours larger than 10 cm in diameter and three with portal vein branch involvement. On univariate analysis, female gender (P = 0.037), absence of ascites (P = 0.028), platelet count below 150 x10(9) per litre (P = 0.011), albumin concentration greater than 35 g/l (P = 0.04), alpha-fetoprotein level below 1000 ng/ml (P = 0.007), unilobar tumour (P = 0.027), fewer than three tumours (P = 0.015), absence of venous invasion (P = 0.011), and tumour diameter less than 8 cm (P = 0.021) were significant predictors of 5-year survival. Albumin concentration greater than 35 g/l (P = 0.011), unilobar tumour (P = 0.012) and alpha-fetoprotein level below 1000 ng/ml (P = 0.014) were independent prognostic factors on multivariate analysis. CONCLUSION: Five-year survival is possible with TACE for inoperable HCC, even in some patients with advanced tumours. Unilobar tumours, alpha-fetoprotein level below 1000 ng/ml and albumin concentration greater than 35 g/l were factors predictive of 5-year survival.

Adult↗
PubMed2003

Desmopressin does not decrease blood loss and transfusion requirements in patients undergoing hepatectomy.

PURPOSE: To determine the effects of desmopressin on coagulation and blood loss in patients undergoing elective partial hepatectomy. METHODS: A randomized, controlled and double-blind study on 59 patients who received either 0.3 micro g x kg(-1) of desmopressin or an equal volume of normal saline (control) infused intravenously over 20 min after induction of general anesthesia. RESULTS: There was an increase in plasma levels of factors VIII and von Willebrand after the infusion of study drug in both groups (P < 0.001). The activated partial thromboplastin time was shortened in Group D whereas prothrombin time was prolonged in Group C; (P = 0.02). A large range of intraoperative blood loss (400-7128 mL) was observed, with no significant differences between groups. There were no changes in plasma electrolyte levels or osmolality. Transfusion requirements were similar in both groups. CONCLUSION: Desmopressin did not reduce intraoperative blood loss or transfusion requirements during hepatectomy despite raising clotting factor levels and improving tests of hemostasis.

Blood Coagulation Tests↗
PubMed2003

Emergency living related liver transplantation for fulminant reactivation of hepatitis B virus after unrelated marrow transplantation.

We report a unique case of emergency living related donor orthotopic liver transplantation (OLT) for late fulminant reactivation of hepatitis B virus (HBV) after matched unrelated bone marrow transplantation (BMT) for chronic myeloid leukemia (CML). Cessation of lamivudine after BMT for HBV positive patients may carry risks of late fatal HBV reactivation. Similar to fulminant HBV reactivation in the general population, OLT under resumption of lamivudine can be life saving. In our case, concomitantly molecular relapse of CML at the time of liver failure was also cleared by OLT, possibly via a 'liver-graft vs. leukemia' effect. Liver rejection (graft vs. graft disease) was mild due to inherent immunocompromise of the marrow graft. Hence BMT recipients in stable remission should not be denied the opportunity for life-saving solid organ transplantation. A choice of marrow and liver donors with innate HBV immunity may be needed to give the additional advantage of long-term HBV clearance.

Adult↗
PubMed2003

Genetics of familial amyloidotic polyneuropathy in a Hong Kong Chinese kindred.

Familial amyloidotic polyneuropathy type 1 (FAP1, MIM176300) is an autosomal dominant disease caused by mutations in the transthyretin (TTR) gene. An extended Chinese kindred of FAP1 was first reported in Hong Kong in 1989, three of the four histologically proven subjects have deceased. TTR gene mutations were not studied then. A DNA-based diagnosis was performed on FAP1 by restriction analysis and direct DNA sequencing was carried out on a symptomatic member of this family who had undergone a liver transplantation. It showed a substitution of thymine by cytosine in the second base of codon 30 in exon 2 of the TTR gene, with the creation of a novel HhaI restriction endonuclease site. Valine is substituted by alanine (V30A) in the mutant TTR. Both restriction analysis and direct sequencing revealed the same mutation in one of the two asymptomatic siblings. This mutation was first reported in a FAP1 family of German descent.

Adult↗
PubMed2002

Right-lobe live donor liver transplantation improves survival of patients with acute liver failure.

BACKGROUND: Right-lobe live donor liver transplantation (LDLT) is used by many liver transplant centres for treating adult patients with terminal liver disease, but its incremental benefit for the intended recipient over cadaveric liver graft transplantation has not been determined. The impact of LDLT as a proactive approach on the outcome of patients with acute liver failure was analysed. METHODS: From January 1999 to March 2001, right-lobe LDLT was offered proactively to 50 consecutive patients with acute liver failure and their families. The outcome of those who opted for right-lobe LDLT (n = 34) was compared with that of those who did not opt for LDLT (n = 16). RESULTS: In the group that opted for right-lobe LDLT, 16 patients eventually received a live donor right-lobe graft (14 patients survived) and three patients received a cadaveric liver graft that became available while the potential live donor was undergoing evaluation (all three patients survived). Among the group who did not opt for LDLT, only one patient received a cadaveric liver graft and survived. The former group had a higher overall survival rate (17 of 34 versus one of 16). With a proactive approach, the overall transplant rate was increased from four of 50 to 20 of 50. The morbidity rate among donors was low and none died. CONCLUSION: Right-lobe LDLT improves the overall survival rate of patients with acute liver failure and should be considered as one of the treatment options for adult patients with acute liver failure.

Adolescent↗
PubMed2002

Activation of cyclin-dependent kinases CDC2 and CDK2 in hepatocellular carcinoma.

BACKGROUND: The cyclin-dependent kinases (CDKs) CDC2 and CDK2 are key regulators of the cell cycle. The expression of the CDK alone does not necessary reflect their true activities because they are highly regulated by post-translational mechanisms. Human hepatocellular carcinoma (HCC) is one of the most common cancers in the world, but the kinase activities of CDKs in HCC have not been examined. METHODS: Here we examined the protein expression and kinase activities associated with CDC2 and CDK2 in HCC and the corresponding non-tumorous liver tissues. RESULTS: CDC2 and CDK2 are activated in HCC in over 70% and 80% of the cases, respectively, but have little correlation with clinical parameters and PCNA expression. Interestingly, PCNA was readily detectable in extracts from non-tumorous liver, but more than 60% of samples contain higher concentration of PCNA in HCC than the corresponding non-tumorous tissues. CDC2 and CDK2 are generally activated in the same HCC samples, but the extent of their activation varied significantly, suggesting that the pathways leading to the activation of CDC2 and CDK2 can be regulated independently. Both positive regulators of CDK activity like cyclins and CDKs, and negative regulators of CDK activity like p21(CIP1/WAF1) and Thr14/Tyr15 phosphorylation were up-regulated in HCC. CONCLUSION: CDC2 and CDK2 are activated in HCC, and this may be due to a complex interplay between the level of the cyclin, CDK, CDK inhibitors, and inhibitory phosphorylation.

CDC2 Protein Kinase↗