Biomedical subjects

Chao-Long Chen

Publications and source records attributed to Chao-Long Chen.

At least 55 records · Page 3Linked to original sources

PubMed2004

Sequential changes of serum aminotransferase levels in patients with severe acute respiratory syndrome.

Severe acute respiratory syndrome (SARS) is a newly emerging infectious disease. To describe the hepatic injury caused by this disease, we report the sequential changes of serum transaminase in probable SARS patients during a hospital outbreak in southern Taiwan. From April to June, 2003, 52 probable SARS patients were hospitalized. Serial serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were retrospectively analyzed and hepatitis B surface antigen (HBsAg) was also evaluated to correlate with the progression of this disease. Fifty-three percent of the patients had abnormal liver function during hospitalization. More than 70% of abnormal transaminase levels were mildly elevated. Most elevated levels were noted during the second week after onset of fever. Neither transaminase elevation nor HBsAg was related to the prognosis of SARS, and only advanced age was an independent predictor of poor outcome. Our study suggested that coronavirus causing SARS might induce liver damage.

Adult↗

PubMed2004

Anesthetic management of a patient with Alagille's syndrome undergoing living donor liver transplantation without blood transfusion.

Alagille's syndrome (AGS), which has five main characteristics including chronic cholestasis; typical peculiar facies; posterior embryotoxon; butterfly-like vertebral-arch defects; and cardiovascular malformations, is rarely seen in Taiwan, especially in a liver transplantation setting. We present the successful anesthetic management of a 3-year-11-month-old boy with AGS. The patient was anemic with a preoperative hemoglobin of 9.1 g/dl and had mild aortic stenosis and mild pulmonary artery stenosis. He underwent living donor liver transplantation without blood transfusion. The key points of successful anesthetic management included complete pre-operative evaluation of the cardiovascular system, and intra-operative maintenance of normothermia, normal ionized calcium, normal pH and stable hemodynamics. Surgical blood loss, ascites and intraoperative transudate loss were primarily replaced with 5% albumin and crystalloids to maintain the central venous pressure around 10 cm H2O. No blood transfusion was given for a hemoglobin level higher than 6-7 g/dl, but the intravascular volume was sufficient to maintain stable hemodynamics. Our patient tolerated the anemia well, it did not seem to affect the recovery of the new liver allograft postoperatively.

Alagille Syndrome↗

PubMed2003

Ionized calcium changes during living-donor liver transplantation in patients with and without administration of blood-bank products.

Exogenous citrate load from blood transfusion during orthotopic liver transplantation is thought to be the main cause of ionized hypocalcemia, which may result in hemodynamic instability. This implies that if no blood is transfused, chelation of free ionized calcium (Ca(++)) by citrate is avoided and supplemental calcium need not be given. For this study, we divided 39 pediatric living-donor liver transplant patients into two groups according to the blood component replacement given: group I received packed red blood cells and fresh frozen plasma with and without 5% albumin, and group II received 5% albumin alone. The intra-operative serial ionized calcium level was recorded, and the amount of calcium chloride replacement to maintain acceptable blood Ca(++) levels was compared between the groups. The mean serum ionized calcium level changes of both groups could be maintained within lower-to-normal limits intra-operatively. The amount of supplemental calcium chloride required to correct the hypo-ionized calcium was not significantly different between the groups. We can conclude that if an exogenous citrate load is eliminated by the avoidance of blood transfusion and 5% albumin infusion is used, instead, to replace the blood and ascites loss during OLT, the risk of ionic hypocalcemia still persists. Serum Ca(++) monitoring and adequate replacement are, therefore, still required in this setting.

Adult↗

PubMed2003

Ethics and rationale of living-donor liver transplantation in Asia.

Living-donor liver transplantation took root in Asia as a natural result of circumstances, because the supply of organs from the cadaveric pool remained scarce over the years. In contrast to Western countries, the majority of organs for liver transplantation in Asia come from live donations. As the expertise of the transplant teams grows, patient outcomes improve, and public awareness increases, the option of live donation of the liver is increasingly chosen. Although no live liver donor death has yet been reported from Asia, the risk is not eliminated and remains a major consideration in the potential donor's decision to donate. The low morbidity and mortality rate could be attributed to the extensive experience of surgeons in liver surgery, because surgical liver disease is highly prevalent in Asia. Although the donor risk is estimated to be low, live organ donation should be absolutely voluntary, with consent given on the basis of unbiased information and chosen only when the option for obtaining a cadaveric graft is practically nil. It is only under these conditions that living-donor liver transplantation should be perpetuated. Although the disease-donation-transplantation process involves a complex interplay of psychosocial and family dynamics, the potential candidate's perception will necessarily depend on the surgeon's explanation. The ethical soundness of the practice of living-donor liver transplantation rests primarily on the ones who deliver the service.

Asia↗

PubMed2003

Living-donor liver transplantation: 12 years of experience in Asia.

Living-donor liver transplantation has provided a solution to the severe lack of cadaveric grafts for the replacement of livers afflicted with end-stage cirrhosis, fulminant disease, or inborn errors of metabolism. The pioneering experience in Japan in the early 1990s helped open wide the avenues of a new branch of science that is technically demanding and whose benefits are clearly dramatic. The need for alternative sources of liver grafts was common to the entire Asian region and, fortunately, the option of obtaining partial liver grafts from live donors had already become tenable. By the second half of the past decade, living-donor liver transplant programs had been successfully established in Hong Kong, Taiwan, and Korea. More than 1,500 cases have been performed over a 12-year period. This report describes the cumulative experience in living-donor liver transplantation in Asia on the basis of data from five major liver transplant centers.

Asia↗

PubMed2003

Evaluation of living liver donors.

Preoperative evaluation of donors for living-donor liver transplantation aims to select a suitable donor with optimal graft quality and to ensure donor safety. There are minor variations in the donor selection process among different centers, but the safety of the donor remains central to the entire process. The potential donors are evaluated in a stepwise manner including medical, physical, laboratory, psychosocial, and imaging assessment to disqualify unsuitable donors as early as possible in the evaluation process. The main goal of the imaging study is to provide an accurate picture of liver vascular anatomy and liver volume measurement for surgical guidance or for exclusion of unsuitable donors. All imaging studies can now be obtained using noninvasive modalities, thereby decreasing the risk associated with the donor evaluation process. This article describes the donor selection practice in our center including the details of the imaging evaluation.

Angiography↗

PubMed2003

Hepatitis B core antibody-positive grafts: recipient's risk.

The transmission of hepatitis B virus infection through hepatitis B core antibody (anti-HBc)-positive liver grafts in hepatitis B surface antigen (HBsAg)-negative recipients has been established. The mandatory use of immunosuppression in transplant patients favors reactivation of latent virus that may be present in grafts from HBsAg-negative anti-HBc-positive donors. With the persistent organ donor scarcity, the use of these grafts cannot be avoided, especially in urgent cases and in areas where the prevalence of the hepatitis B virus is high, as in Asia. The recognition of posttransplant de novo hepatitis B from core antibody-positive liver donors has, therefore, led to modifications in graft allocation policies and the introduction of strategies for prophylaxis. The risk of developing this type of new-onset hepatitis B virus infection in liver transplant recipients and the various approaches to minimize this risk are reviewed. The peculiar implications of using core antibody-positive grafts in the context of living donor liver transplantation in Asia are discussed.

Hepatitis B↗

PubMed2003

A phase I study of autologous dendritic cell-based immunotherapy for patients with unresectable primary liver cancer.

BACKGROUND/AIMS: To evaluate the safety and feasibility of immunotherapy based on autologous dendritic cells (DC) for patients with unresectable primary liver cancer (PLC). METHODS: A total of ten patients were enrolled and immunized with DCs. Autologous DCs were generated ex vivo in the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4). Cells were then pulsed with tumor lysate (TL), tumor necrosis factor-alpha (TNF-alpha) and keyhole limpet hemocyanin (KLH). Non-adherent cells were collected on day 9 and cells were administered into the inguinal lymph node. Each patient received 1-10 x 10(6) cells four times at weekly intervals. RESULTS: Immunization was well tolerated in all patients without significant toxicity. DC vaccination induced delayed-type hypersensitivity (DTH) against KLH in seven out of ten patients. In one patient, one of the two liver tumors (tumor in segment 7, 13 mm in diameter) decreased in size to 7 mm and showed necrotic change on computed tomography examination after eight immunizations. In two patients, serum levels of tumor markers decreased after vaccination. CONCLUSION: The present clinical trial suggested that immunization by TL-pulsed DCs is feasible in patients with unresectable PLC without any toxicity. Further improvement in the clinical results of immunotherapy might be expected by modifying the therapeutic protocol.

Aged↗

PubMed2003

Stress response to hepatectomy in patients with a healthy or a diseased liver.

Partial hepatectomy is a major upper abdominal operation associated with certain stress to the patient. Successful adaptation to such stress is a prerequisite for survival. Donor hepatectomy with maximal safety is a principal concern during living donor liver transplantation. The purpose of the study was to compare the stress response by assessing cytokines and the acute-phase response induced by hepatectomy in patients with a healthy liver and those with a diseased liver. Fourteen patients undergoing partial right hepatectomy were enrolled in this study. Seven of them were donors for living related liver transplantation (group 1, or GI); the other seven were patients with hepatocellular carcinoma due to chronic hepatitis B (Child's class A) (GII). Blood samples for interleukin-6 (IL-6), tumor necrosis factor-alpha (TNFalpha), and C-reactive protein (CRP) assays were collected before the operation, at the beginning and end of the operation, and 24 and 48 hours after the operation. The data were analyzed and compared in the same group using the Friedman test and between groups using the Mann-Whitney U-test. A value of p < 0.05 was regarded as significant. Results showed that resection of the liver in patients with both healthy and disease livers leads to significant increases in IL-6 and CPR but not TNFalpha. Significantly lower levels of IL-6 before and after operation in GI patients compared to those in GII patients suggests that GI patients adapted to surgical stress more easily than did the GII patients.

Adaptation, Physiological↗

PubMed2003

The protective mechanism of magnolol, a Chinese herb drug, against warm ischemia-reperfusion injury of rat liver.

BACKGROUND: Cell apoptosis following warm ischemia-reperfusion injury is a major concern in clinical issues such as organ transplantation, trauma, and cardiogenic shock. The purpose of this study was to evaluate the possible role of magnolol, a Chinese herb drug, in apoptotic injury and the kinetic expression of apoptotic-related genes in rat livers subjected to warm ischemia-reperfusion (WI/R). MATERIALS AND METHODS: Three weeks prior to the experiment 10 rats underwent a portosystemic shunt operation according to Bengmerk's method. The rats were divided into three groups. Group 1 (GI) was the control group, Group 2 (GII) and Group 3 (GIII) the magnolol-treated groups. GI and GII were subjected to 2 h and GIII to 3 h of WI/R by clamping the portal vein and hepatic artery under ether anesthesia. RESULTS: Results show that all the control rats died after 2 h WI/R. Apoptotic cells were detected under microscopy as well as by DNA assay. Magnolol-treated groups tolerated warm ischemia-reperfusion for 2 h and significantly less apoptotic cells were observed (198 +/- 22 vs 42.6 +/- 28). But magnolol-treated rats could not tolerate 3 h warm ischemia-reperfusion. RT-PCR of liver tissue shows that there is an upregulated expression of the anti-apoptotic Bcl-xL gene and suppression of the Bcl-xS gene in GII. CONCLUSION: Magnolol has an anti-apoptotic effect and protects the liver against WI/R for 2 h but not for 3 h through upregulation of the anti-apoptotic Bcl-XL gene and suppression of the Bcl-xS gene.

Animals↗

PubMed2003

The effect of liver graft-body weight ratio on the core temperature of pediatric patients during liver transplantation.

The left lateral segment of the liver from an adult living donor sometimes is relatively too large for a small pediatric recipient. It currently is unknown whether a high graft-recipient body weight ratio (GRWR) has a significant effect on core temperature during the anhepatic and reperfusion phases of living donor liver transplantation (LDLT). Seventy-two pediatric patients undergoing LDLT were divided into two groups according to body weight. Group I (GI) consisted of patients with a body weight greater than 10 kg, and group II (GII), less than 10 kg. Core temperature, measured as nasopharyngeal temperature (NT), was compared between groups at induction of anesthesia, hourly during the following 6 hours, as the lowest core temperature at the anhepatic phase, 5 and 30 minutes after reperfusion, and the last 2 hours before the end of the operation. Mild hypothermia of 35.8 degrees C +/- 0.7 degrees C and 35.9 degrees C +/- 0.4 degrees C for GI and GII was noted after induction of anesthesia, respectively; this increased +/- 1 degrees C in the following 6 hours. In the anhepatic and reperfusion phases, a sudden and significant decrease in NT was observed in both groups. This decrease in NT was significantly greater in GII than GI. In conclusion, a sudden decrease in core temperature was observed during the anhepatic and reperfusion phases of LDLT in pediatric patients, likely caused by placement of the cold liver graft, which is flushed with 4 degrees C lactated Ringer's solution during vessel reconstruction, in the anhepatic phase and return of venous blood through the cold preserved liver in the reperfusion phase. Core temperatures of pediatric patients with a body weight less than 10 kg in GII, who received grafts with a high GRWR, were more affected than those in GI.

Body Temperature↗

PubMed2003

Potent stimuli combined with lipopolysaccaride and IFNgamma may improve immunotherapy against HCC by increasing the maturation and subsequent immune response of the dendritic cells.

Dendritic cells (DCs)-based immunotherapy is a new strategy for cancer treatment and has been used in some clinical trials against cancer, including melanoma, and has shown promising results. However, the conventional protocol of DC immunotherapy may not be effective for hepatocellular carcinoma (HCC) because of impaired DC maturation in HCC patients. In order to induce sufficient maturation on HCC derived DCs, we tested various stimuli such as tumor necrosis factor (TNF) alpha, lipopolysaccharide (LPS), interferon (IFN)gamma and CD40-ligand. In stimulating with LPS + IFNgamma, DCs of HCC patients expressed significantly high levels of CD86 (p < 0.05) and produced high levels of IL-12 as compared to DCs stimulated with TNFalpha alone. Moreover, it showed better ability to stimulate allogeneic mixed lymphocyte reaction. It concluded that LPS and IFNgamma was the best combination of stimuli for induction of sufficient maturation on DCs derived from HCC.

Carcinoma, Hepatocellular↗

PubMed2003

Right lobe living donor liver transplantation-addressing the middle hepatic vein controversy.

OBJECTIVE: To describe our approach in the decision-making for taking the middle hepatic vein with the graft or leaving it with the remnant liver in right lobe live donor liver transplantation. SUMMARY BACKGROUND DATA: Right lobe living donor liver transplantation has been successfully performed. However, the extent of donor hepatectomy is still a subject of debate and the main considerations in the decision making are graft functional adequacy and donor safety. METHODS: An algorithm based on donor-recipient body weight ratio, right lobe-to-recipient standard liver volume estimate, and donor hepatic venous anatomy was used to decide the extent of donor hepatectomy. This algorithm was applied in 25 living donor liver transplant operations performed between January 1999 and January 2002. In grafts taken without the middle hepatic vein, anterior segment tributaries draining into it were not reconstructed. Outcomes between right lobe liver transplants with (Group I) and without (Group II) the middle hepatic vein were compared. RESULTS: Ten grafts included the middle hepatic vein and 15 did not. The mean graft to recipient standard liver volume ratio was 58% and 64% in Groups I and II, respectively, and the difference was not statistically significant. Donors from both groups had comparable recovery, with 2 complications, 1 from each group, requiring a percutaneous drainage procedure. The recipient outcomes were, likewise, comparable and there was 1 case of structural outflow obstruction in Group I, which required venoangioplasty and stenting. There were 2 recipient mortalities, 1 due to a biliary complication and the other to recurrent hepatitis C. Another patient required retransplantation for secondary biliary cirrhosis. The overall actuarial graft and patient survival rates are 84% and 96%, respectively, at a median follow-up of 16 months. CONCLUSION: Based on certain preoperative criteria, a right lobe graft can be taken with or without the middle hepatic vein with equally successful outcomes in both the donors and recipients. The decision, therefore, of the extent of right lobe donor hepatectomy should be tailored to the particular conditions of each case.

Adult↗

PubMed2003

A survey of the oral status of children undergoing liver transplantation.

BACKGROUND: The purposes of this study were to examine the oral tissues and caries prevalence of children undergoing liver transplantation, and to evaluate the relationship between tooth staining and serum bilirubin level. METHODS: Thirty-four children (22 boys and 12 girls) under the age of 6 years with end-stage liver disease were referred from the Liver Transplantation Center at Kaohsiung Chang Gung Children's Hospital, Taiwan. Oral tissues were examined, and photographs taken to determine the green staining of the teeth and gingiva. A questionnaire was completed by their parents. Serum bilirubin levels were collected preoperatively in these children. Student's t-test was used to compare the mean decayed, missing, and filled tooth (dmft) difference between night-fed and non-night-fed groups, and to test the relationships between tooth staining and serum bilirubin levels. RESULTS: The caries prevalence of the 34 children undergoing liver transplantation was 61.8%. The mean dmft score of children 2 to 6 years old who were night-fed was significantly higher than that of children who were not (10.1 +/- 1.2 vs. 6.3 +/- 1.2; p = 0.038). Green staining of the teeth and gingiva was found in 61.3% of cases in children with biliary atresia. Total serum bilirubin levels were significantly higher in the green-stained group than in the non-stained group (17.87 +/- 2.50 vs. 2.20 0.65; p < 0.01). CONCLUSIONS: Oral findings of children undergoing liver transplant presented significant green staining of the teeth and gingiva related to high serum bilirubin levels. Children who were night-fed showed an increased risk of developing caries suggesting that oral hygiene instructions should begin as early as possible before liver transplantation.

Bilirubin↗

PubMed2003

Urachal inflammatory mass mimicking an intra-abdominal tumor two years after excision of the urachal sinus in a child.

A 2-year-and-2-month-old boy presented with a tender fist-sized mass in the lower abdomen for 3 days. Turbid urine was also a complaint. His urachal sinus and umbilicus had been removed at the age of 2 months. Abdominal ultrasonography and computed tomography revealed a tumor mass beneath the lower abdominal wall. Total excision of the mass was performed. Microscopic examination showed an abscess located next to a small urachal remnant without stitches or foreign body reaction. To our knowledge, an urachal inflammatory mass mimicking an intra-abdominal tumor after excision of the urachal sinus, especially in children, is very rare. The factors causing such an urachal mass are discussed.

Abdominal Neoplasms↗

PubMed2002

Immunization with Epstein-Barr Virus (EBV) peptide-pulsed dendritic cells induces functional CD8+ T-cell immunity and may lead to tumor regression in patients with EBV-positive nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC), a common neoplasm in Southeast Asia, is EBV-positive and expresses a limited number of antigens, including latent membrane protein 2. In this study, autologous monocyte-derived dendritic cells were cultured from patients with advanced NPC, matured with cytokine, pulsed with HLA-A1101-, A2402-, or B40011-restricted epitope peptides from EBV latent membrane protein 2 and injected into inguinal lymph nodes. Sixteen patients with local recurrence or distant metastasis after conventional therapies received four injections at weekly intervals. Epitope-specific CD8+ T-cell responses were elicited or boosted in 9 patients receiving HLA-A1101- or A2402-restricted peptides, with stronger responses seen to the A1101 peptide. Furthermore, epitope-specific cytotoxicity was detectable in peripheral blood T cells harvested at 3-months after vaccination from A1101-responsive patients, and in 2 patients, this coincided with partial tumor reduction. Approaches leading to stronger and more sustained EBV-specific T-cell responses, therefore, may have therapeutic potential in the context of NPC.

Adult↗

PubMed2002

Split liver transplantation.

Greater experience and improved outcomes in liver transplantation have necessarily led to longer waiting lists against a constantly limited donor pool. Split liver transplantation has been conceived as a means to increase the supply of liver grafts. The bipartition of a whole liver provides grafts for two recipients in a complex operation with equally complex manpower and logistical demands. The in situ technique of splitting offers advantages over the ex vivo technique, although after the time-dependent learning curve is overcome, they may theoretically be used interchangeably with acceptable outcomes. Aside from surgical expertise, donor characteristics and recipient pre-transplant status are risk factors for survival. This review will address the salient aspects of split liver transplantation, summarize the world experience with this procedure and describe the preliminary attempts in Asia.

Adult↗

PubMed2002

Prevention of de novo hepatitis B virus infection in living donor liver transplantation using hepatitis B core antibody positive donors.

Exclusion of liver grafts from hepatitis B core antibody (anti-HBc) positive donors to prevent de novo hepatitis B virus (HBV) infection after liver transplantation is not feasible in areas highly endemic for HBV virus like Taiwan, where approximately 80% of adults are anti-HBc(+). The efficacy of lamivudine monotherapy to prevent de novo HBV infection after living donor liver transplantation (LDLT) using grafts from anti-HBc(+) donors remains to be elucidated. From June 1994 to August 2000, LDLT was performed in 42 recipients. Twenty-four of the 42 donors were anti-HBc(+) (57%). Pre-transplant HBV vaccination was given to all recipients irrespective of anti-HBc status at monthly intervals for 3 months. Until December 1997, eight recipients received liver grafts from anti-HBc(+) donors without prophylaxis. Since January 1998, prophylaxis with lamivudine monotherapy was given to 16 recipients receiving liver grafts from anti-HBc(+) donors. De novo HBV infection occurred in three of the eight recipients (37.5%) who did not receive prophylaxis, while none of the 16 recipients given lamivudine developed de novo HBV infection after a mean follow-up of 25 months. Two of the three recipients with de novo HBV infection were anti-HBs(-) and one recipient was anti-HBs(+). Lamivudine was well tolerated, and no side effects were noted. These results suggest that lamivudine monotherapy for recipients receiving anti-HBc(+) liver grafts is a simple, relatively inexpensive and effective prophylactic regimen for prevention of de novo HBV infection. The additive protection provided by vaccine-induced or natural immunity is uncertain.

Adolescent↗