PubMed Health⌕ Search

Biomedical subjects

K T Woo

Publications and source records attributed to K T Woo.

At least 73 records · Page 4Linked to original sources
PubMed1992

Can therapeutic interventions prevent chronic renal failure?

One way to prevent chronic renal failure (CRF) is to institute preventive measures against renal diseases in the general population. Patients with hereditary kidney diseases should have genetic counselling. Certain infections affecting or causing kidney diseases can be eradicated. People should be cautious in the use of analgesics and non-steroidal anti-inflammatory agents. Exposure to hydrocarbons, heavy metals and toxic gases should be avoided. Proper management of diabetes mellitus, gout, renal stones and hypertension can prevent renal damage. In patients with established renal disease, the following factors if treated or modified can prevent or ameliorate renal injury: glomerular hypertension, cell mediated proliferation, lipid induced proliferation, coagulation and thrombosis. Pregnancy in patients with renal disease should be well managed and termination advised if necessary. Reversible causes of renal failure as well as acute reversible elements can be removed or treated. Acute renal failure due to toxins can be avoided, although prevention requires awareness of association with renal failure. Prevention too depends on early detection of nephrotoxic injury like: greater awareness of hazards of environmental toxins, careful monitoring of dosage of nephrotoxic drugs and when possible, total avoidance of nephrotoxins should be the rule. Finally, in patients with glomerular disease, prevention or amelioration of glomerular damage with pharmacological agents have been achieved in some instances.

Genetic Counseling↗
PubMed1991

Cell-mediated immunity in patients on hemodialysis: relationship with hepatitis B carrier status.

We compared cell-mediated immune responses in two groups of patients on hemodialysis. One group of patients were chronic carriers of hepatitis B virus (HBV), and the patients of the other group were HBV antigen negative. Our results show that despite the presence of normal numbers of T cells and an increased CD4/CD8 ratio in both groups of patients compared to healthy controls (p less than 0.0001), only the group of patients who were chronic HBV carriers showed depressed lymphoproliferative responses to phytohemagglutinin (p less than 0.001) and concanavalin A (p less than 0.0001). In contrast, a control group of healthy adult HBV carriers showed normal T cell subsets and lymphoproliferative responses to mitogens, indicating that HBV infection per se did not result in depressed lymphoproliferative responses. These results further substantiate the notion that depressed cell-mediated immunity in chronic renal failure is an important factor in predisposing patients to HBV infection with subsequent development of the chronic carrier state.

Adult↗
PubMed1991

Seroprevalence of antibodies to the hepatitis C virus in Singapore.

The prevalence of antibodies to the hepatitis C virus (anti-HCV) in Singapore was assessed using a recombinant-based enzyme linked immunoassay system. 1004 serum samples were obtained from normal subjects (463), hemodialysis patients (112), hepatitis B virus (HBV) carriers (188), patients with hepatocellular carcinoma (HCC) (58) and patients with non-hepatitis B virus related liver diseases (183). Anti-HCV was found to be positive in 1.7% of healthy subjects, and in 20% of patients on regular hemodialysis. Three percent of HBV carriers were positive for anti-HCV. Twelve percent of patients with acute hepatitis with no known causes and 20% patients with chronic hepatitis with no known causes were positive for anti-HCV. Among patients with cirrhosis for which no known causes were found 33% were positive for anti-HCV. Thirty six percent of patients with HCC not associated with the presence of HBsAg were positive of anti-HCV. None of the patients with known causes of liver disease were positive for anti-HCV.

Adolescent↗
PubMed1991

Pharmacokinetics and nephrotoxicity of cyclosporine.

Cyclosporine (CsA) is a potent immunosuppressive agent which has dramatically improved graft and patient survivals in clinical solid organ transplantation. However, CsA nephrotoxicity (NTX) is the most frequent and serious side effect of CsA therapy and occurs in a significant proportion of patients. The clinical presentation of NTX is that of reduced creatinine clearance, elevation of serum creatinine and a disproportionate rise in blood urea. The clinical picture occurs as three syndromes, namely acute, subacute and chronic CsA NTX. Regardless of the clinical syndrome, the pathoaetiology of NTX is related to decline in renal blood flow and increase in renal vascular resistance probably due to CsA induced changes in renal haemodynamics. Unfortunately, the dose that yields an optimal therapeutic index, namely maximal efficacy with minimal toxicity has yet to be defined. Optimal dosing is confounded by not only inter and intraindividual variabilities in drug absorption, distribution and metabolism, but also by the lack of a clear relationship between drug efficacy and trough CsA level monitoring. This paper describes the pharmacokinetics and nephrotoxicity of CsA and evaluates various strategies to overcome this toxicity.

Absorption↗
PubMed1991

Maintenance haemodialysis in Singapore.

The chronic haemodialysis programme of the Singapore General Hospital started in 1968 as a hospital-based fully nurse-assisted programme. This has since expanded to include Self Dialysis and Home Dialysis programmes. Data of 425 patients who entered the dialysis programmes was analysed retrospectively. The major cause of end stage renal failure was chronic glomerulonephritis (52%). Almost half of the patients in the haemodialysis programme were patients on self-dialysis (49%). There were 157 withdrawals and 116 deaths. Survival has improved tremendously with the use of treated water for dialysis from 1981. The 5 year survival in an earlier group of patients dialysed with untreated water was 48% compared with 81% in a late group dialysed with treated water (p less than 0.001). The pattern of complications has also changed with a lower incidence of dialysis osteomalacia, hypertension, hepatitis and eradication of dialysis dementia.

Acute Kidney Injury↗
PubMed1991

Pattern of proteinuria in IgA nephritis by SDS-PAGE: clinical significance.

Of sixty patients with IgA nephritis, none had CRF at first examination, 13 developed CRF with creatinine above 1.6 mg/dl within 6 years. Among these patients who had analysis of proteinuria by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE), 31 patients had middle molecular weight (MMW) proteinuria alone (pattern 1), 10 had MMW and Low MW (LMW) or tubular proteinuria (pattern 2), 10 had high MW (HMW) and MMW proteinuria (Pattern 3) and 9 had HMW, MMW and LMW proteinuria (Pattern 4). At the end of a follow up period of 6 years (1983-1989) patients with mixed proteinuria had a higher incidence of chronic renal failure (CRF), 11/29 (38%) compared to those with pattern 1 proteinuria, 2/31 (6%) (chi 2 = 8.7, p less than 0.005). Based on the glomerular selectivity index (GSI), 19 patients had nonselective proteinuria but they did not have a higher incidence of CRF. By the selectivity index (SI), 18 patients had nonselective proteinuria and they showed a significantly higher incidence of CRF. Compared to the 41 patients who did not have LMW proteinuria, 19 patients with LMW proteinuria had more severe proteinuria. After a follow-up period of 6 years, patients with LMW proteinuria had a higher incidence of CRF (10% versus 47%, p less than 0.001). The presence of LMW proteinuria indicates a less favourable outcome and the pattern of proteinuria as assessed by the SDS-PAGE appears to be a better prognostic index in IgA nephritis than the SI and the GSI.

Adult↗
PubMed1991

Acute renal failure prognostic indices in hospital inpatients referred for haemodialysis.

Forty-eight patients with acute renal failure (ARF) who were referred to the Department of Renal Medicine, Singapore General Hospital for acute dialysis between August 1985 and August 1989 were studied retrospectively to identify risk factors associated with ARF that serve as prognostic indicators. There was no difference in the mean age of survivors and non-survivors (49.5 +/- 17.5 years vs 53.5 +/- 18 years, p greater than 0.05). The overall mortality rate was 52%. ARF as a result of surgical complication had a higher mortality rate in comparison to ARF from medical complications (66% vs 50%, p greater than 0.05). Septicaemia was the most common cause of ARF requiring dialysis. Hepatobiliary sepsis was the most frequent cause of septicaemia. Pre-dialysis serum urea and creatinine levels, and the number of dialysis treatments did not affect the outcome. Poor prognostic indicators included oliguria or anuria, fluid overload and coma. Patients tended to have a worse outcome if they had more than three risk factors taken from the following list:-decreased renal perfusion, assisted ventilation, coma, gastrointestinal dysfunction, recent surgery, sepsis, congestive heart failure, hepatobiliary dysfunction, malignancy, diabetes mellitus, chronic renal insufficiency and poor nutritional status. Early referral of patients with septicaemia due in particular to hepatobiliary infection may improve the prognosis.

Acute Kidney Injury↗
PubMed1991

Acute cyclosporin A induced nephrotoxicity in renal allografts.

Immunosuppression with Cyclosporin A has resulted in dramatic improvements in the results of cadaveric kidney transplantation in Singapore. However, its major limitation is its nephrotoxicity which can appear in various forms after transplantation including a delay in graft function and chronic renal dysfunction. The clinical course of two patients with initial function but delayed onset of acute functional Cyclosporine nephrotoxicity are described. Recovery was documented in both cases with reduction of Cyclosporine dosage. A decline in renal blood flow and increase in renal vascular resistance is likely to have played a role in the pathogenesis of the acute functional nephrotoxicity. Cyclosporine induced imbalance in Prostaglandin synthesis within the kidney has been implicated.

Acute Disease↗
PubMed1991

Effects of triple therapy in IgA nephritis: a follow-up study 5 years later.

This study is a 5-year post trial assessment of patients with IgA nephritis who entered a 3-year prospective controlled trial of cyclophosphamide, dipyridamole (D) and low-dose warfarin (W). Patients entered the trial from 1979 to 1981 and the trial ended in 1984 with those in the treatment group having more stable renal function and less proteinuria compared to the control group. Present reassessment of the patients in 1989 showed no difference in the renal function between those in the treatment group (n = 27) and the control group (n = 21). 6 patients in the treatment group and 7 in the control group were in ESRF. At the conclusion of the trial in 1984, among the 27 patients in the original treatment group, 13 patients elected to continue with D + W while the other 14 patients chose to cease therapy and therefore served as the new control group. 5 years later, renal function in the new treatment group (n = 13) was significantly stable compared to the new control group (n = 14), (serum creatinine 1.4 +/- 0.7 versus 4.4 +/- 3.2 mg/dl, p less than 0.01). Furthermore, all the 6 patients with ESRF in the original treatment group of 27 patients were from the new control group (n = 14) where treatment with D + W had been ceased. None of the patients still on D + W are in ESRF.

Adult↗
PubMed1990

Hepatitis B vaccination in chronic renal failure patients undergoing haemodialysis: the immunogenicity of an increased dose of a recombinant DNA hepatitis B vaccine.

Thirty-two patients with end stage renal failure who were on haemodialysis and who had no previous exposure to hepatitis B virus were given four intramuscular injections of 40 micrograms (twice the recommended dose) recombinant DNA hepatitis B vaccine (Engerix B, Smith Kline Biologicals) at 0, 1, 2 and 6 months to determine the immunogenicity of this increased vaccine dose. The ages of these patients ranged from 23-54 years with a mean age of 40 years. There were 11 males and 21 females. Three patients underwent renal transplantation during the course of the study and were assessed separately. Antibody levels above 10 IU/L were noticed in 83% of the remaining 29 patients two months after the final dose with an anti-HBs geometric mean titre (GMT) of 2551 IU/L. The antibody response was 82% four months later although the GMT has fallen to 664 IU/L. Renal transplantation did not appear to affect the anti-HBs response to the above vaccination regime. None of the volunteers developed hepatitis B during the study. Our results were much better than results obtained in studies using twice the recommended doses given three times.

Adult↗