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Biomedical subjects

K C Tan

Publications and source records attributed to K C Tan.

At least 127 records · Page 7Linked to original sources
PubMed1994

Orthotopic liver transplantation for acute hepatic failure in children.

Thirty children received 35 liver transplants for fulminant or late-onset liver failure between March 1988 and May 1993. Aetiology included non-A non-B hepatitis in 12, Wilson's disease in 8, drug-induced hepatic failure in 6, hepatitis B in 1, hepatitis A in 1, tyrosinaemia in 1 and congenital haemochromatosis in 1. Three patients were retransplanted, one each for hepatic artery thrombosis, non-A non-B graft reinfection, and chronic rejection. Two of these three patients received a third transplant for chronic rejection and hepatic artery thrombosis. One patient in the retransplant group survived. Overall, graft and patient survival at a mean follow-up of 17 months were 49% and 57%, respectively. Mortality was related to vascular complications in three patients (hepatic venous obstruction, portal vein thrombosis and hepatic artery thrombosis). Two patients died of primary sepsis (cerebral aspergillosis and cytomegalovirus (CMV) pneumonitis in association with graft-versus-host disease). Systemic sepsis and multiorgan failure was documented as a cause of death in four children and sepsis in association with chronic rejection in a further three patients. One child died of respiratory failure 4 weeks after transplantation. Mortality in eight children less than 2 years was 75% and this was significantly greater than for older children (P < 0.003, Mantel Cox). Earlier referral, even in the absence of a definitive diagnosis and particularly in children under 2 years is advisable and may improve survival.

Adolescent↗
PubMed1994

Emergency liver transplantation after Kasai portoenterostomy.

Three patients with stable liver function after Kasai portoenterostomy developed acute liver failure secondary to liver necrosis. Doppler ultrasound at presentation revealed reversed diastolic hepatic arterial blood flow. Two patients survived after urgent liver transplantation. Liver necrosis should be suspected in children with chronic liver disease presenting with fever and rapidly deteriorating liver function.

Emergencies↗
PubMed1994

Glycogenosis type IV: liver transplant at 12 years.

Hepatomegaly, the presenting feature of type IV glycogen storage disease at 20 months of age, regressed during childhood. The patient remained asymptomatic until 12 years of age when, after an episode of shock, septicaemia, and spontaneous peritonitis, liver transplantation was successfully performed.

Child, Preschool↗
PubMed1994

Fulminant hepatic failure resulting from coexistent Wilson's disease and hepatitis E.

Fulminant hepatic failure resulting from hepatitis E and coexistent Wilson's disease was diagnosed in a six year old girl six weeks after returning from a holiday in India. Wilson's disease was diagnosed on the basis of histological evidence of hepatocellular copper deposition, confirmed by biochemical estimation of liver copper concentration. Although severely damaged, the liver was non-cirrhotic. Hepatitis E virus (HEV) was diagnosed by nested polymerase chain reaction, the specificity of which was confirmed by direct sequencing of amplified DNA. Replication of HEV within the liver at the time of diagnosis was confirmed by selective amplification of the antigenomic strand of the virus obtained from total liver RNA. The patient had an orthotopic liver transplantation without recurrence of hepatitis and remains well at 19 months. Viral excretion, recorded by serial amplification of HEV RNA extracted from stool samples, persisted for 30 days after liver grafting. Severe vitiligo, present preoperatively, dramatically improved after liver grafting and institution of immunosuppressive treatment. This case suggests that viral infection may play a part in the acute decompensation seen in some cases of Wilson's disease.

Base Sequence↗
PubMed1994

T cell clones generated from patients with type 1 diabetes using interleukin-2 proliferate to human islet antigens.

T lymphocytes are implicated in the pathogenesis of Type 1 (insulin dependent) diabetes. Activated T lymphocytes expressing IL-2 receptors are found at increased levels in the peripheral blood in the prediabetic period, at diagnosis and for several months after the onset of the disease, but their role in the pathogenesis of the disease is not known. We have used co-culture of peripheral blood lymphocytes with IL-2 alone to selectively generate T cell clones from the in vivo activated T cell population, and examined the phenotype and antigen specificity of the clones derived. From 3 patients with newly-diagnosed Type 1 diabetes 184 clones were generated, the majority of which (39%) were CD4+TCR alpha beta+, whilst 31% were CD8+TCR alpha beta+. From 2 healthy control subjects 90 clones were obtained, of which 62% were CD4+TCR alpha beta+ and 33% were CD8+TCR alpha beta+. Antigen specificity was examined in 46 clones from the patients and 44 from the control subjects in proliferation assays, using as antigens homogenate of human islets of Langerhans, human islet membrane preparation and human liver membrane preparation. Three clones (all CD4+TCR alpha beta+) from the patients, but none from the control subjects, proliferated in a dose dependent fashion in response to stimulation with human islet homogenate presented by autologous APCs, but to neither of the other autoantigen preparations. Our results demonstrate that a relatively high proportion (7%) of T lymphocytes activated in vivo recognise human islet antigens, indicating that they may have a role in the pathogenesis of the disease.

Adult↗
PubMed1994

Deep-seated infective mediastinitis in post-coronary artery bypass grafting patients.

The median sternotomy is the preferred incision for coronary artery bypass grafting (CABG) but its usage was initially associated with wound infection rates of up to 5%. The advent of antibiotic prophylaxis and improved surgical technique has improved these rates to 1% to 2% in most series. During a 5-year period from January 1988 to December 1992, 2193 patients underwent CABG in the Singapore General Hospital. Of these, 22 (1%) suffered postoperative wound infection. Thirteen (0.59%) of these had deep-seated mediastinitis which involved the osteocartilagenous tissues and retrosternal space and 9 (0.41%) had superficial wound infections. The superficial infections were successfully treated with dressings and delayed closure in all cases. The deep-seated infections, however, required in addition, antibiotic therapy, povidone iodine irrigation, repeated debridement and flap closure. In total, 6 muscle and myocutaneous flaps were used with good result. This paper reviews the Plastic Surgery unit's experience in treating this difficult postoperative complication.

Anti-Bacterial Agents↗
PubMed1993

Controlled trial of prophylactic versus therapeutic use of ganciclovir after liver transplantation in adults.

The potential of prophylactic ganciclovir for the control of cytomegalovirus (CMV) infection was evaluated in a prospective controlled trial of 65 patients after liver transplantation. A group of 33 patients received ganciclovir (10 mg/kg/day) during the third and fourth weeks after transplantation, while 32 patients were randomised to receive ganciclovir (10 mg/kg/day) only when clinical CMV disease was diagnosed. Eight patients (25%) in the latter group received ganciclovir and included the only death attributed to CMV infection in the study. Prophylactic ganciclovir was associated with a lower incidence of serologically diagnosed secondary infection and the development of the IgM anti-CMV antibody. However, the frequency of clinical infections was similar in the two groups (9/33 vs. 11/32). Liver function tests during the second month after transplantation were not significantly better in the patients receiving prophylactic ganciclovir. Leucopaenia was not seen in patients receiving prophylactic ganciclovir.

Adult↗
PubMed1993

China's small town urbanization program: criticism and adaptation.

"China's 12,000 designated towns and more than 40,000 rural market towns have experienced a major transformation since the institution of rural reforms in the late 1970s. Rural industrialization based on the concept of 'leaving the soil but not the village, entering the factory but not the town' has contributed to the revitalization of many small towns. But this rural urbanization has also brought about a number of problems in the countryside, leading many to propose the adoption of the concept of 'leaving the soil and the village' as another basis of China's small town urbanization. This essay attempts to examine this transformation, particularly the recent criticism and adjustment made to the small town urbanization program."

Asia↗
PubMed1993

Altered cellular signalling and decreased platelet sensitivity to adenosine in insulin-dependent diabetic patients with proliferative retinopathy.

Platelets from patients with insulin-dependent diabetes with proliferative retinopathy showed the same reactivity to ADP as those from control subjects. Responsiveness of platelets to the aggregation inhibitor adenosine and to the analogue N-ethylcarboxamidoadenosine was decreased in diabetes. In contrast, responsiveness to the anti-aggregatory effects of prostaglandin I2 was not significantly altered in diabetes. Platelets from diabetic patients exhibited decreased formation of cyclic AMP in response to N-ethylcarboxamidoadenosine compared with those from control subjects. In contrast, when adenylyl cyclase was stimulated by prostaglandin I2 or by forskolin, no differences in cyclic AMP formation were observed between control and diabetic platelets. Diabetes was associated with an apparent loss of high-affinity binding of [3H]N-ethylcarboxamidoadenosine to platelet membranes. Possible mechanisms that could contribute to this diabetes-induced change in signalling through the platelet A2 adenosine receptor are discussed.

Adenosine↗
PubMed1993

Recurrence of primary biliary cirrhosis after liver transplantation following FK506-based immunosuppression.

We report two cases of recurrence of primary biliary cirrhosis (PBC) in the transplanted liver whilst maintained on a FK506-based immunosuppressive regime, the first to be described. One patient experienced symptoms in association with the development of cholestasis. In both there was a persistence of serological markers of PBC and liver histology revealed florid bile duct destruction and a granulomatous reaction.

Adult↗
PubMed1993

Liver transplantation for primary hepatocellular carcinoma: tumor size and number determine outcome.

Liver transplantation for primary hepatocellular carcinoma (HCC) has in general been complicated by high recurrence rates. In the present study results from experience of 87 patients were analyzed [56 cirrhotic, 31 non-cirrhotic, 6 with the fibrolamellar (FL) variant] in relation to curative potential. Sixty-two survived > 90 days and form the study cohort. Fifty-six had non-fibrolamellar HCC and, of these, 39 had discrete lesions, measuring 0.8-21 cm (median 5.0 cm) including 4 in whom the diagnosis was made after examination of the explanted liver; 23 had multifocal lesions (> 2 tumor masses). There was no tumor recurrence in the group of 14 cases with single dominant lesions measuring < 4 cm, whereas in the 15 cases with lesions of 4-8 cm the recurrence rate was 40%, and 78% in those > 8 cm and the multifocal lesions (n = 27, P = 0.0001). Five-year actuarial survival figures were 57.1%, 44.4% and 11.1% (P < 0.003) respectively. The mean survival times in patients who died of recurrence were: 4-8 cm, 3.3 years (range 10 months to 6.3 years); > 8 cm or multifocal, 13 months (3-25 months). Reduction of serum alpha-fetoprotein (AFP) to normal levels does not exclude a later recurrence (7 of 17 cases) and this was documented after maintenance of normal AFP levels for up to 29 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Carcinoma, Hepatocellular↗
PubMed1993

Ethnic variations in patient and graft survival after liver transplantation. Identification of a new risk factor for chronic allograft rejection.

The ethnic origin of renal graft recipients is recognized as an important determinant of graft survival. In liver transplantation, the effect of racial origin has been studied in black American recipients and has suggested a trend toward inferior graft survival in this group. In this study, we have analyzed outcome of transplantation in a large multiethnic liver transplant program. Non-Caucasoid recipients had an inferior patient survival compared with Caucasoids and, in particular, European Caucasoids at 1, 3, and 5 years after transplantation (46.7% vs. 60.2% at 3 years, P = 0.05). Non-European recipients had an inferior graft survival compared with European recipients at 1, 2, and 3 years after transplantation (e.g., north Europeans 53.5%, south Europeans 48.5%, Middle Eastern 40%, and non-Caucasoids 27% at 3 years, P < 0.01). Different frequencies of chronic allograft rejection in the ethnic groups contributed to the rates of graft survival, with the non-European recipients developing chronic rejection at over twice the rate of European recipients (12.6% vs. 5.9%, respectively, P = 0.002). The findings in this study support the evidence from renal transplant programs that the ethnic origin of recipients is an important determinant of outcome after transplantation, with increasing frequency of chronic rejection in recipients nonindigenous to the donor population contributing to the variations in patient and graft survival rates.

Adult↗
PubMed1993

Decreased sensitivity to adenosine in platelets from patients with familial hypercholesterolaemia--a change reversed by cholestyramine treatment.

Platelet-rich plasma was obtained from patients with untreated heterozygous familial hypercholesterolaemia (FH), from FH patients treated with cholestyramine and from control subjects. Responsiveness of platelets to the aggregation inhibitors adenosine, its analogue N-ethylcarboxamidoadenosine (NECA) and prostaglandin I2 was decreased in FH. Patients on cholestyramine therapy showed normal responsiveness to adenosine and NECA. There were only minor changes in the binding of [3H]NECA to high-affinity binding sites on platelet membranes from untreated FH or cholestyramine-treated FH patients. The initial rate of cyclic AMP formation in response to a high concentration of NECA was severely decreased in platelets from FH patients. By contrast, the rate of cyclic AMP formation in response to forskolin or a high concentration of prostaglandin I2 was unchanged. These data point to a defect in the coupling of the platelet A2 adenosine receptor to adenylyl cyclase in untreated FH patients.

Adenosine↗
PubMed1993

Gangrene of the anterior abdominal wall after orthotopic liver transplantation: invasive cutaneous candidiasis.

Fungal infections following liver transplantation are not uncommon and may be life-threatening. Superficial candidal infections of the bronchus, oesophagus and urinary tract are the most common mode of presentation. Invasive cutaneous and subcutaneous candidiasis is, however, very rare. We report two patients with invasive cutaneous and subcutaneous candidiasis after orthotopic liver transplantation.

Abdominal Muscles↗
PubMed1993

Immunological characterisation of the lichen planus infiltrate using monoclonal antibodies.

The immunological typing of cell populations in the skin biopsies of 20 cases of histologically proven lichen planus was done using monoclonal antibodies. The Avidin-Biotin-Complex immunoperoxidase technique was used. A predominance of T-helper/inducer cells in the dermal infiltrate was observed by a semiquantitative analysis. T-suppressor/cytotoxic cells and Langerhans cells were increased compared to eczema lesions. A comparison of the staining of Langerhans cells using monoclonal antibodies and the S100 protein stain showed that more Langerhans cells could be identified with the CD1 monoclonal antibody. The type of infiltrate did not correlate with the duration of disease. Direct immunofluorescence staining demonstrated fibrinogen at the dermo-epidermal junction and/or colloid bodies in the upper dermis. The immunophenotyping and immunofluorescence pattern in local cases of lichen planus are similar to previous reports from other countries. An interesting finding was the unexplained disproportionate predominance of Indians in the study cohort.

Adolescent↗