Biomedical subjects

C L Liu

Publications and source records attributed to C L Liu.

At least 19 recordsLinked to original sources

PubMed2007

Living donor versus deceased donor liver transplantation for early irresectable hepatocellular carcinoma.

BACKGROUND: Hypothetical studies that favour living donor liver transplantation (LDLT) for early hepatocellular carcinoma (HCC) assumed a comparable outcome after LDLT and deceased donor liver transplantation (DDLT). The aim of this study was to compare the outcome after LDLT with that after DDLT, and to identify factors that might account for any differences. METHODS: The study included 60 patients who met the radiological Milan or University of California at San Francisco (UCSF) criteria and underwent LDLT (43 patients) or DDLT (17). RESULTS: The LDLT group had fewer incidental tumours and a lower rate of pretransplant transarterial chemoembolization but a higher rate of salvage transplantation. Waiting time was shorter and graft weight to standard liver weight (GW : SLW) ratio was lower in this group. The perioperative course, and histopathological tumour size, number, grade and stage were comparable. Median follow-up was 33 (range 4-120) months. The cumulative 5-year recurrence rate was 29 per cent in the LDLT group and 0 per cent in the DDLT group (P = 0.029). A GW : SLW ratio of 0.6 or less, salvage transplantation, three or more tumour nodules, microscopic vascular invasion, and pathological stage beyond the Milan or UCSF criteria were significant confounding risk factors. Multivariable analysis identified salvage transplantation (relative risk 5.16 (95 per cent confidence interval (c.i.) 1.48 to 18.02); P = 0.010) and pathological stage beyond the UCSF criteria (relative risk 4.10 (95 per cent c.i. 1.02 to 16.48); P = 0.047) as independent predictors of recurrence. CONCLUSION: Despite standard radiological selection criteria based on number and size, patients who underwent LDLT for HCC had more recurrence because of selection bias for other clinical characteristics.

Adolescent↗

PubMed2006

Serial analysis of JAK2 mutation in a patient who developed essential thrombocythemia after orthotopic liver transplantation.

A 52-year-old man developed essential thrombocythemia (ET) with JAK2 V617F mutation after orthotopic liver transplantation (OLT). Retrospective analysis showed that, despite a low platelet count, the JAK2 mutation was already found at presentation 14 months before OLT. The high platelet count that would have been typical of ET might be masked by the cirrhosis-related hypersplenism. Thrombocythemia became obvious after OLT. The patient subsequently developed blastic transformation 12 months afterward, a process probably accelerated by the immunosuppression required for the OLT.

Amino Acid Substitution↗

PubMed2006

Improved operative and survival outcomes of surgical treatment for hilar cholangiocarcinoma.

BACKGROUND: The aim of the present study was to assess whether an aggressive surgical approach in the management of patients with hilar cholangiocarcinoma was associated with improved operative and survival outcomes. METHODS: Eighty-two patients with hilar cholangiocarcinoma treated between 1989 and 1998 (period 1), and 60 patients treated between 1999 and 2004 (period 2), were evaluated. Modifications to management in period 2 primarily included percutaneous biliary drainage instead of endoscopic drainage for relief of obstructive jaundice, preoperative right portal vein embolization before right-sided hepatectomy, routine total caudate lobectomy and radical lymphadenectomy during surgical resection of the tumour. RESULTS: The surgical resection rate was significantly higher in period 2 than in period 1 (45 versus 16 per cent; P < 0.001). All patients in period 2 underwent major hepatectomy with concomitant caudate lobectomy. The operative morbidity and hospital mortality rates decreased significantly in period 2 compared with period 1, with significantly better survival outcomes. In multivariate analysis, resection of the tumour in period 2 and operative blood loss of 1.5 litres or less were the significant independent factors associated with improved survival. CONCLUSION: An aggressive surgical approach was associated with improved operative and survival outcomes for patients with hilar cholangiocarcinoma.

Aged↗

PubMed2006

Irreversible aggregation of protein synthesis machinery after focal brain ischemia.

Focal brain ischemia leads to a slow type of neuronal death in the penumbra that starts several hours after ischemia and continues to mature for days. During this maturation period, blood flow, cellular ATP and ionic homeostasis are gradually recovered in the penumbral region. In striking contrast, protein synthesis is irreversibly inhibited. This study used a rat focal brain ischemia model to investigate whether or not irreversible translational inhibition is due to abnormal aggregation of translational complex components, i.e. the ribosomes and their associated nascent polypeptides, protein synthesis initiation factors and co-translational chaperones. Under electron microscopy, most rosette-shaped polyribosomes were relatively evenly distributed in the cytoplasm of sham-operated control neurons, but clumped into large abnormal aggregates in penumbral neurons subjected to 2 h of focal ischemia followed by 4 h of reperfusion. The abnormal ribosomal protein aggregation lasted until the onset of delayed neuronal death at 24-48 h of reperfusion after ischemia. Biochemical study further suggested that translational complex components, including small ribosomal subunit protein 6 (S6), large subunit protein 28 (L28), eukaryotic initiation factors 2alpha, 4E and 3eta, and co-translational chaperone heat-shock cognate protein 70 (HSC70) and co-chaperone Hdj1, were all irreversibly clumped into large abnormal protein aggregates after ischemia. Translational complex components were also highly ubiquitinated. This study clearly demonstrates that focal ischemia leads to irreversible aggregation of protein synthesis machinery that contributes to neuronal death after focal brain ischemia.

Analysis of Variance↗

PubMed2006

Wilson's disease: a patient undiagnosed for 18 years.

Wilson's disease, an autosomal recessive disorder of copper metabolism, is the most common inherited hepatic disease in Hong Kong. Diagnosis is based on the presence of Kayser-Fleischer rings, typical neurological symptoms, and/or a low serum ceruloplasmin concentration (<0.20 g/L). Early detection and treatment protect patients and their presymptomatic siblings from devastating organ damage. The diagnosis of Wilson's disease may nonetheless be overlooked if only established clinical and laboratory tests are used as diagnostic criteria. We report diagnosis of the disorder using genetic analysis of ATP7B in a presymptomatic sibling who escaped diagnosis during family screening 18 years previously. The patient was 11 months old when family screening was performed following diagnosis of Wilson's disease in an elder sister. The boy was considered to be unaffected on the basis of laboratory results in the expected range: serum copper level, 4.6 micromol/L; serum ceruloplasmin level, 0.16 g/L; and 24-hour urinary copper excretion, 0.14 micromol/day. Molecular analysis of ATP7B was performed; it revealed that the two siblings shared the same compound heterozygous mutations (G943D and 2299delC). We recommend that molecular diagnosis is the only definitive means of diagnosing Wilson's disease in children younger than 1 year.

Adolescent↗

PubMed2005

Clinico-biochemical prediction of biliary cause of acute pancreatitis in the era of endoscopic ultrasonography.

BACKGROUND: Occult biliary stones escape detection on conventional investigations, and clinico-biochemical systems proposed for predicting biliary pancreatitis has low predictive values. AIM: To evaluate the accuracy of clinico-biochemical parameters for prediction of biliary pancreatitis in patients undergoing endoscopic ultrasonography. METHODS: Early endoscopic ultrasonography was performed on 139 patients presenting with acute pancreatitis within 24 h of admission. The aetiologies of all patients were determined after complete evaluations, and clinico-biochemical characteristics of patients with a biliary cause (biliary group) and non-biliary causes (non-biliary group) were compared. RESULTS: Biliary pancreatitis was diagnosed in 107 patients and 32 patients had non-biliary causes. The biliary group belonged to a significantly older age group, had a female predominance, significantly more derangement of liver function and a higher incidence of severe attack of acute pancreatitis. On multivariate analysis, female sex, age >58 years and serum alanine aminotransferase >150 U/L were independent predictive factors for biliary cause of acute pancreatitis. Using these three factors for prediction of biliary cause, the sensitivity was 93% and overall accuracy was 85%. CONCLUSION: Clinico-biochemical prediction for biliary cause of acute pancreatitis improves in the era of endoscopic ultrasonography with a higher sensitivity and overall accuracy. In centres where endoscopic ultrasonography is inaccessible or local expertise is unavailable, clinico-biochemical prediction of biliary cause of acute pancreatitis may provide a useful alternative in the initial management of this group of patients.

Acute Disease↗

PubMed2005

Co-translational protein aggregation after transient cerebral ischemia.

Transient cerebral ischemia leads to irreversible translational inhibition which has been considered as a hallmark of delayed neuronal death after ischemia. This study utilized a rat transient cerebral ischemia model to investigate whether irreversible translational inhibition is due to abnormal aggregation of translational complex, i.e. the ribosomes and their associated nascent polypeptides, initiation factors, translational chaperones and degradation enzymes after ischemia. Translational complex aggregation was studied by electron microscopy, as well as by biochemical analyses. A duration of 15 or 20 min of cerebral ischemia induced severe translational complex aggregation starting from 30 min of reperfusion and lasting until the onset of delayed neuronal death at 48 h of reperfusion. Under electron microscopy, most rosette-shaped polyribosomes were relatively evenly distributed in the cytoplasm of sham-operated control neurons. After ischemia, most ribosomes were clumped into large abnormal aggregates in neurons destined to die. Translational complex components consisting of small ribosomal subunit protein 6, large subunit protein 28, eukaryotic initiation factor-3eta, co-translational chaperone heat shock cognate protein 70 and co-chaperone HSP40-Hdj1, as well as co-translational ubiquitin ligase c-terminus of hsp70-interacting protein were all irreversibly clumped into large abnormal protein aggregates after ischemia. Translational components were also highly ubiquitinated. To our knowledge, irreversible aggregation of translational components has not been reported after brain ischemia. This study clearly indicates that ischemia damages co-translational chaperone and degradation machinery, resulting in irreversible destruction of protein synthesis machinery by protein aggregation after ischemia.

Animals↗

PubMed2005

Living donor liver transplantation for hepatitis C related hepatocellular carcinoma in a haemophilia A patient.

We report the first case of unrelated living liver transplantation for hepatitis C related hepatocellular carcinoma (HCC) in a Chinese patient with haemophilia A. The development of cirrhosis and HCC was insidious in this patient, who has previously failed interferon treatment despite low viral load and genotype 6a. With factor VIII and novoseven support, there were no operative complications and there was no need for blood transfusion. Postoperative pegulated interferon treatment resulted in viral clearance with no increased cellular rejection. The use of living donors represent a potential life saving therapeutic options for hepatitis C virus related complications in haemophiliac, especially in countries of organ shortage. Careful patient and donor choice, meticulous surgical expertise and proper counselling, however, are prudent requirements.

Adult↗

PubMed2005

Subcutaneous Rosai-Dorfman disease: is surgical excision justified?

Rosai-Dorfman disease in soft tissue without nodal disease has been recognized as a distinct clinicopathologic entity. It may represent a diagnostic challenge and the natural history and optimal treatment has not been well clarified. We investigated a patient in whom Rosai-Dorfman disease was confined to the subcutis of the abdominal wall and recurred after incomplete excision. Complete resolution was achieved by wide surgical excision with negative margins. Pathologic examination confirmed the diagnosis of extranodal Rosai-Dorfman disease. The patient is disease-free after 1 year of follow-up. Despite the possibility that spontaneous remission may occur, our results suggest that when anatomically feasible, complete excision can be a treatment option for persistence or recurrence of exclusively extranodal disease. Larger case series and longer follow-up are needed to assess the long-term efficacy in these patients.

Abdominal Wall↗

PubMed2005

Portal vein embolisation prior to extended right-sided hepatic resection.

OBJECTIVES: To determine whether preoperative portal vein embolisation improves the operative outcome of patients undergoing extended right-sided hepatic resection for hepatobiliary malignancy. DESIGN: Prospective non-randomised study. SETTING: University teaching hospital, Hong Kong. PATIENTS: Ninety-two patients underwent extended right-sided hepatic resection for hepatobiliary malignancy during a 45-month period (January 2000 to September 2003). Among them, 15 (16%) underwent portal vein embolisation via a percutaneous ipsilateral approach (n=9) or through the ileocolic vein with a mini-laparotomy (n=6). The remaining 77 (84%) patients underwent hepatic resection without portal vein embolisation. MAIN OUTCOME MEASURES: Operative morbidity and mortality. RESULTS: Patients undergoing portal vein embolisation were older (69 years vs 55 years; P=0.009), and had significantly worse preoperative renal function (creatinine, 96 micromol/L vs 86 micromol/L; P=0.039) and liver function (bilirubin, 23 micromol/L vs 12 micromol/L; P<0.001). Portal vein embolisation resulted in an increase in the future liver remnant of 9% (interquartile range, 7-13%) of the estimated standard liver volume. The operating time for patients receiving portal vein embolisation was significantly longer (medium, 660 min vs 420 min; P<0.001) with more complicated surgery performed in terms of concomitant caudate lobectomy and hepaticojejunostomy. There was no hospital mortality in patients who underwent portal vein embolisation whereas five without the treatment died (P=0.587). The operative morbidity of patients who underwent portal vein embolisation and those who did not was 20% and 30%, respectively (P=0.543). CONCLUSIONS: In older patients who have worse preoperative liver and renal functions, portal vein embolisation enhances the possibility to perform extended right-sided hepatic resection for hepatobiliary malignancies with potentially lower operative mortality and morbidity.

Aged↗

PubMed2004

Different presentation of hepatitis B-related hepatocellular carcinoma in a cohort of 1863 young and old patients - implications for screening.

AIM: To compare the clinico-pathological features of hepatitis B virus-related hepatocellular carcinoma in young and old patients. METHODS: The clinico-pathological characteristics of hepatitis B virus-related hepatocellular carcinoma were compared in 1863 consecutive patients (121 patients, </=40 years; 1742 patients, > 40 years) seen at a single institution over the last 13 years. RESULTS: Young patients presented more often with pain (P < 0.0001), hepatomegaly (P = 0.01) and ruptured hepatocellular carcinoma (P = 0.02), whereas old patients presented with ankle oedema (P = 0.001), ascites (P = 0.002) and by routine screening (P = 0.035). Liver function, Child-Pugh grading and indocyanine green test were better preserved in young patients. They also had a higher alpha-foetoprotein concentration (P = 0.001), larger tumour size (P = 0.001) and more frequent metastasis (P = 0.008), but a similar surgical resection rate (33.6% vs. 28%), to old patients. There was no difference between the two groups in the overall post-resection survival rate, but there was a shorter survival in young patients with unresectable disease (3.6 months vs. 4.6 months, P = 0.004). Young patients with hepatocellular carcinoma often show a later presentation, but a higher resectability rate and similar survival rates, than old patients. The screening programme should include young hepatitis B virus carriers, even in the absence of cirrhosis.

Adolescent↗

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↗

PubMed2004

Pathogenesis of hippocampal neuronal death after hypoxia-ischemia changes during brain development.

Transient hypoxia-ischemia (HI) leads to delayed neuronal death in both mature and immature neurons but the underlying mechanisms are not fully understood. To understand whether the pathogenesis of HI-induced neuronal death is different between mature and immature neurons, we used a rat HI model at postnatal days 7 (P7), 15 (P15), 26 (P26) and 60 (P60) in order to investigate ultrastructural changes and active caspase-3 distribution in HI-injured neurons as a function of developmental age. In P7 pups, despite more than 95% of HI-injured neurons highly expressing active caspase-3, most of these active caspase-3-positive neurons revealed mixed features of apoptosis and necrosis (a chimera type) under electron microscopy (EM). Classical apoptosis was observed only in small populations of HI-injured P7 neurons. Furthermore, in rats older than P7, most HI-injured neurons displayed features of necrotic cell death under EM and, concomitantly, active caspase-3-positive neurons after HI declined dramatically. Classical apoptosis after HI was rarely found in neurons older than P15. In P60 rats, virtually all HI-injured neurons showed the shrinkage necrotic morphology under EM and were negative for active caspase-3. These results strongly suggest that pathogenesis of HI-induced neuronal death is shifting from apoptosis to necrosis during brain development.

Age Factors↗

PubMed2004

The effect of oxidants on 2-MIB concentration with the presence of cyanobacteria.

In this study, the effect of three oxidants, sodium hypochlorite, potassium permanganate, and ozone, were tested for the removal of 2-MIB with presence of cyanobacteria. Algae in water samples from the source water of Feng-Shen waterworks (FSW), Taiwan were cultivated at 30 degrees C with continuous light at an intensity between 2,500 and 3,400 lux. During the cultivating process, water samples were analyzed for nutrients, light absorbance at 665 nm (A665), and 2-MIB concentration. The 2-MIB concentrations within the incubated samples increased to as high as 1,000 ng/L to 2,000 ng/L, although no extra nutrients were added to the raw water. After 2 to 3 days incubation, the intracellular 2-MIB concentration was as high as 70% of the total 2-MIB in the samples. The algae that developed were mainly cyanobateria, and more than 90% belonged to the Genus Oscillatorias. An almost 100% removal of both 2-MIB and geosmin in the raw water was observed after ozonation for 10 minutes at a dosing rate of 0.91 mg/l-min. Chlorine and permanganate were much less effective, both removing only about 11% of the 2-MIB within 60 minutes at oxidant concentration of 10 mg/l. Oxidation of the cultivated samples showed that chlorine and permanganate may damage algae cells causing them to release intracellular 2-MIB. During the 60 minutes of reaction time, the total 2-MIB concentrations (intracellular plus dissolved) varied by no more than 10%, however, the ratios between dissolved and total 2-MIB concentrations increased. Two effects of ozonation on the 2-MIB concentration in the cultivated samples were observed when the algae were young, namely 2-MIB release from damaged cells and 2-MIB oxidization. The rates of 2-MIB release and 2-MIB destruction were similar. However, old algae cells were more easily damaged. As a result, intracellular 2-MIB was released faster, and the soluble 2-MIB was destroyed more quickly by ozonation.

Camphanes↗

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

Solid-phase microextraction from small volumes of sample in a glass capillary.

A new sampling method is proposed for solid-phase microextraction (SPME), in which the extraction is carried out in a glass capillary containing a few microliters of sample. When an adsorption-type fiber is used for SPME, the equilibrium between aqueous sample and coating can be described by a Langmuir isotherm. Since the total amount of analytes and coexisting substances stays at a low level in a small volume of sample, the linear concentration range of analytes will be extended for SPME to be applied in quantification and the interference caused by sample matrix will be reduced. In addition, sampling in a capillary has a short diffusion distance and extraction equilibrium is established in 5-10 min. It is important in clinical analysis and therapeutic drug monitoring to be able to analyse sample volumes of samples. The feasibility of the new sampling method is demonstrated by the extractions of p-hydroxybenzaldehyde and a synthetic solution containing 1-naphthol, paeonol and 1-naphthylamine.

Chromatography, Gas↗

PubMed2003

Immunoprofile of cervical and endometrial adenocarcinomas using a tissue microarray.

Adenocarcinomas of the uterine cervix show a wide range of morphological features, and can be confused with endometrial adenocarcinoma in biopsy or curetting specimens. The objective of this study was to use tissue microarray technology to evaluate the immunoprofile of a large set of uterine adenocarcinomas with an extended panel of antibodies, comparing the profile of primary cervical and endometrial adenocarcinomas. A tissue microarray was constructed using paraffin-embedded, formalin-fixed tissues from 141 hysterectomy specimens. Duplicate 0.6-mm cores were obtained from 57 cervical adenocarcinomas (16 in situ and 41 invasive) and 84 endometrial adenocarcinomas. Tissue array sections were immunostained with 21 commercially available antibodies [B72.3, CD 99, carcinoembryonic antigen (CEA), c-kit, pancytokeratin, CK 5/6, CK 7, CK8/18, CK19, CK 20, CK 22, EMA, estrogen receptor (ER), KP-1, melan-A, p53, PLAP, S-100, synaptophysin, TTF-1, and vimentin] utilizing the avidin-biotin (ABC) technique. Hierarchical clustering analysis of the tumors was done based on the immunostaining results. Only ER ( P<0.001), CEA ( P=0.04), vimentin ( P<0.001), and CK 8/18 ( P=0.002) showed a significantly different frequency of positivity in endometrial relative to cervical adenocarcinomas. ER, vimentin, and CK 8/18 were more likely to be expressed in endometrial adenocarcinomas, while cervical adenocarcinomas more frequently expressed CEA. We were able to identify immunoprofiles that were highly specific for endocervical adenocarcinoma (ER(-), vimentin(-), CK 8/18(-), CEA(+)) or endometrial adenocarcinoma (ER(+), vimentin(+), CK 8/18(+), CEA(-)), but most tumors showed an intermediate, non-specific immunophenotype. Hierarchical clustering analysis was useful in the interpretation of these intermediate immunophenotypes. Papillary serous adenocarcinoma of the endometrium was less likely to express vimentin ( P=0.002) than endometrioid carcinoma of the endometrium.

Adenocarcinoma↗