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Biomedical subjects

Y O Tan

Publications and source records attributed to Y O Tan.

At least 37 records · Page 2Linked to original sources
PubMed1986

4'-Epidoxorubicin (Epirubicin) as a single agent in advanced primary hepatocellular carcinoma--a preliminary experience.

41Epidoxorubicin (Epirubicin) is a new anthracycline analogue which has activity in a variety of cancers. Advanced primary hepatocellular carcinoma is a rapidly fatal neoplasm. Studies with doxorubicin (Adriamycin) in Africa and Asia have shown a response rate around 30-50% with modes gains in median survivals in patients who responded. We report here our preliminary experience with epirubicin in advanced primary hepatocellular carcinoma. We treated 13 patients with advanced primary hepatocellular carcinoma with epirubicin using a dose of schedule of 60 mg/m +/- at the beginning and gradually escalated to 90 mg/m +/- as tolerated. All patients had no prior chemotherapy. Median age was 51 years with range of 31 to 70 years. Cardiotoxicity was serially monitored with radionuclide multigated left ventriculogram. Objective responses were observed in 3 (23%) patients of the 13 evaluable patients. The median duration of these responders was 30 weeks (range 20 to 42). The overall median survival was 11 weeks. Two patients had cardiotoxicity as measured by a significant fall in left ventricular ejection fraction. The toxicities are much less than doxorubicin and better tolerated. We feel that epirubicin has definite activity in primary hepatocellular carcinoma even in patients with advanced disease.

Adult↗
PubMed1985

New perspectives in therapy of small cell lung cancer.

Small cell lung cancer (SCLC) displays many unique features which are not present in the other subtypes of lung cancer. The clinical presentation with its unique paraneoplastic syndrome and early metastatic spread make SCLC a protean diagnostic problem. Until recently, SCLC was considered to have the worst prognosis in lung cancer. However the natural history of this cancer has been altered substantially over the past ten years with the application of combined modality therapy using combination chemotherapy and radiation therapy. Numerous clinical trials have demonstrated the four to five fold improvement in survival for patients with limited disease treated with combination chemotherapy and radiation therapy. There are several active chemotherapeutic agents such as cyclophosphamide, doxorubicin, etoposide, vincristine, methotrexate and cisplatinum which are currently used in various combination regimens. The role of radiation therapy is undergoing changes with an improvement in results when used in combination with chemotherapy. It no longer plays a primary role but remains a valuable adjunct in the management of small cell lung cancer. There is a diminishing role for surgery in this type of lung cancer. The therapeutic progress in SCLC has reached a plateau in the past four to five years. However much progress has been made in understanding the biology of SCLC. Armed with a better understanding of the biology of SCLC, we can hopefully formulate better treatment regimens and ultimately further improve therapeutic results.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1985

Suppressor cell function in renal failure and transplant patients.

Suppressor cell function was assessed in 13 patients with chronic renal failure not on dialysis, 10 patients on regular hemodialysis and 11 renal transplant patients by means of the Concanavalin A inducible Suppressor Cell Assay. The mean Suppression Index (S.I.) in the undialysed patients (0.76 +/- 0.39) and those of the dialysed patients (0.72 +/- 0.18) were not significantly different from the 25 healthy controls (0.68 +/- 0.22). However the S.I. in the renal transplant patients (1.11 +/- 0.41) was significantly different from the normal controls as well as the undialysed and dialysed patients. Although there was no correlation between S.I. and age, post transplant follow up period, serum creatinine concentration, prednisolone or azathioprine dosage it is likely that the cause of the impaired suppressor cell function was due to the immunosuppressive agents used.

Adult↗
PubMed1984

Beta-2-microglobulin in mesangial IgA nephropathy.

This study measured plasma beta 2-microglobulin (beta 2-m) in patients with mesangial IgA nephritis. Plasma beta 2-m was measured in 51 patients with IgA mesangial nephritis and in 50 normal controls using a Phadebas beta 2-m RIA kit available from Pharmacia Diagnostics (Uppsala, Sweden). The mean plasma beta 2-m in IgA nephritic patients (1.92 +/- 0.67 mg/l) was significantly different from that of healthy controls (1.33 +/- 0.41 mg/l; p less than 0.001). The mean plasma beta 2-m in non-IgA nephritic patients (1.83 +/- 0.73 mg/l) was also significantly different (p less than 0.001). Patients with IgA nephritis with glomerular sclerosis (n = 33) had significantly higher levels of beta 2-m (2.02 +/- 0.70 mg/l) than IgA nephritic patients without glomerular sclerosis (n = 18, 1.72 +/- 0.65 mg/l; p less than 0.025). In the group with IgA nephritis and glomerulosclerosis, raised beta 2-m levels were correlated with the severity of proteinuria (r = 0.41) (p less than 0.02) as well as the intensity of IgA staining on immunofluorescence (r = 0.34; p less than 0.05). Elevated beta 2-m levels in IgA nephritis may serve as a useful prognostic marker.

Adolescent↗
PubMed1984

Chemotherapy of disseminated testicular cancer--a Singapore experience.

Eighteen patients with bulky Stage II B or disseminated germinal neoplasms of the testis were treated with 4 months induction chemotherapy regimen of vinblastine, bleomycin and cis-diamminedichloroplatinum since July 1980. Subsequent maintenance therapy for responding patients consisted of monthly vinblastine and bleomycin. The duration of maintenance therapy was 10 months. Twelve patients (66%) entered into complete remission while 4 patients (22%) were partial responders. VP 16-213 (Etoposide) was added to the regimen for those partial and nonresponders. However there was a high percentage (66%) of relapse at 1 year. Major toxicities were severe gastrointestinal toxicities and mild myelosuppression. There was no drug related death. Problems encountered with this programme were compliance of patients, high costs of drugs and short-lived duration of complete remission. It can be concluded that disseminated germinal cells tumours of testis is highly responsive to combination chemotherapy containing cis-platinum, bleomycin and vinblastine.

Adult↗
PubMed1984

Myelodysplastic syndromes: an analysis of clinical and haematological features.

A retrospective analysis of 24 cases of myelodysplastic syndromes was performed between 1979-1984. There were 16 men and 8 women with a mean age of 69 years and 65 years respectively. The most common haematological features at initial presentation were refractory macrocytic anaemia, reticulocytopenia and associated with either bicytopenia or pancytopenia. The bone marrow was often cellular with megaloblastoid erythropoiesis and in 7 patients (29%), there were ring sideroblasts. Often there was associated dysgranulopoiesis and dysthrombopoiesis Myelodysplastic syndromes appear morphologically to be a heterogenous entity. An attempt to classify them according to the recent proposal of the French-American-British (FAB) Co-operative Group was made. Transformation into acute non-lymphocytic leukaemia occurred in 6 patients (25%). The mean interval between diagnosis and transformation to acute leukaemia was 13 months (range 3-30 months). Acute leukaemia in these patients were refractory to conventional chemotherapy. There were 14 deaths (58%) observed during the period and the common causes of deaths were acute leukaemia, infections and haemorrhage. At present there is no specific or generally effective therapy for this haematologic entity.

Aged↗
PubMed1983

The clinical relevance of platelet aggregation study in myeloproliferative disorders.

30 unselected patients with various entities of the myeloproliferative syndrome were entered into a prospective study to evaluate the relationship between platelet aggregation abnormalities and hemostatic complications and the role of aggregation study in myeloproliferative disorders. 21 patients showed impaired collagen-induced aggregation and absent second phase epinephrine-induced response. 6 of these patients had bleeding manifestations. 4 patients hyperaggregated with ADP, collagen, epinephrine and arachidonic acid. Of these, 3 had thrombotic complications as their initial presentation. In the 6-40 months follow-up no new cases of bleeding or thromboembolic phenomena were encountered among the remaining patients. In 3 patients aggregation abnormalities heralded the specific myeloproliferative disorder by months or years. We conclude from this study that routine platelet aggregation study in classical myeloproliferative disorders is unwarranted as it is costly and does not improve the diagnostic accuracy nor yield any predictive information concerning the tendency to bleed. It is useful as an accessory investigative tool in the atypical or early myeloproliferative patient whose clinical features, blood and marrow findings although suggestive are not diagnostic of a specific myeloproliferative entity.

Adolescent↗
PubMed1982

Beta-thromboglobulin in mesangial IgA nephritis.

Plasma beta-thromboglobulin (beta-TG) concentration were determined in 28 patients with mesangial IgA nephritis (17 with focal glomerular sclerosis and 11 without any glomerular sclerosis) and compared with those from 52 normal subjects and 24 patients controls with no evidence of renal disease. The mean beta-TG concentration in the patients with IgA nephritis [159 +/- 63 ng/ml (SD)] significantly different from the patients controls [32 +/- 25 ng/ml (SD)] (p less than 0.001) as well as the group of normal subjects [23 +/- 17 ng/ml (SD)] (p less than 0.001). In another group of 12 patients with diffuse mesangial proliferative glomerulonephritis with no IgA deposits (non IgA nephritis) the mean beta-TG concentration [126 +/- 86 ng/ml (SD)] though different from that of the normal as well as patient controls (p less than 0.001) was not significantly different from the IgA nephritis patients. The elevated beta-TG levels in the nephritic patients showed no correlation with serum creatinine, creatinine clearance or proteinuria but was significantly correlated with the degree of glomerular sclerosis (r = 0.44) (p less than 0.05). In vivo activation of the platelets is suggested by these findings of elevated beta-TG in patients with diffuse proliferative mesangial glomerulonephritis (IgA and non IgA).

Adolescent↗
PubMed1982

Loss of concanavalin A induced suppressor T-lymphocyte function in patients with mesangial IgA nephritis.

Using the method of concanavalin A (Con a) inducible suppressor activity the peripheral mononuclear cells (PMC) of 17 patients with Mesangial IgA nephritis, 13 patients with idiopathic mesangial proliferative glomerulonephritis but with no IgA deposits on immunofluorescence (Non-IgA nephritis) and 18 healthy subjects were studied. DNA synthesis was measured by incorporation of 3H Thymidine. The mean suppression index (S.I.) of 0.94 +/- 0.08 (SEM) in the IgA nephritic patients was significantly different from that of the non-IgA nephritic patients (0.67 +/- 0.05) (P less than 0.01) as well as the group of normal healthy controls (0.64 +/- 0.05) (P less than 0.0025). The data show that patients with IgA nephritis have abnormal suppressor cell function and suggest an autoimmune basis in the pathogenesis of IgA nephritis.

Adult↗
PubMed1982

Nephrotic syndrome associated with malignant tumours.

The nephrotic syndrome complicating malignancy is an unusual occurrence. We report here four cases of nephrotic syndrome associated with malignant tumours. Three cases were associated with bronchogenic carcinoma and one with adenocarcinoma of colon. One of the four cases developed nephrotic syndrome before the discovery of bronchogenic carcinoma. All patients had renal biopsies with light microscopy, immunofluorescence and electron microscopy. The findings suggest an immune-complex disease complicating malignancy. The true incidence of nephrotic syndrome associated with malignant tumours is unknown. However it is clinically prudent to screen for malignancy in older patients presenting with nephrotic syndrome.

Aged↗
PubMed1982

Cardiac amyloidosis--diagnosis by 2-dimensional echocardiography.

In the past, the precise diagnosis of amyloid cardiomyopathy without resort to invasive techniques has been difficult. Recent experience with 2-dimensional echocardiography in cardiac amyloidosis has suggested that there are characteristic, and perhaps unique, features that are regularly imaged. We describe a case where usage of this non-invasive technique allowed accurate definition of cardiac involvement by amyloid.

Adult↗
PubMed1981

New concepts on the acute leukaemias: morphology, classification, cell biology, chemotherapy, supportive care, immunotherapy and bone marrow transplantation.

The advances in chemotherapy, understanding of leukaemia cell biology and supportive care for acute leukaemia patients offer substantial prospect for cure in the future. Intensive treatment of acute leukaemia requires the resources of specialised unites for support of bone marrow failure. Where possible, patients should be referred to such units for diagnostic classification and intensive remission induction therapy. The understanding of leukaemia cell biology and the detection of colony stimulating activity in normal granulocytes and marrow has helped in predicting early relapses in leukaemia patients. Allogeneic sibling bone marrow transplantation for patients in remission offers a 70% chance of 3 years survival and disease-free state compared to 10% survival for the non-grafted patients treated on maintenance chemotherapy alone. Current evidence suggests that such transplanted patients do not require long term chemotherapy or anti-G.V.H. treated now that the problem of graft-versus-host disease in transplant recipients appears to be overcome by the use of Cyclosporin A.

Acute Disease↗
PubMed1981

Malignant histiocytosis --- a case report.

Malignant Histiocytosis (MH) is an uncommon disorder characterised by systemic tissue infiltration of atypical histiocytes and its precursors. The clinical features included fever with weight loss, hepatosplenomegaly and pancytopenia. The antemortem pathology of the lymph node and bone marrow were non-specific and non-diagnostic. However, at autopsy, there were florid pathological changes of malignant histiocytosis. This case illustrates the difficulty of making a definite antemortem diagnosis of this rare malignant condition and the terminology, aetiology and pathological features are discussed.

Adult↗
PubMed1981

One year review of the blood cell separator programme.

Using the Haemonetic Model 30 intermittent continuous flow centrifuge, 142 procedures, including 64 granulocytes and platelets, 68 platelet collection, 8 therapeutic leukapheresis and 2 plasmapheresis were performed. Granulocyte transfusions (mean collection 1.39 x 10(10) granulocytes) were given to 27 neutropenic patients for febrile episodes which were unresponsive to systemic antibiotics. Thirty-eight thrombocytopenic patients received a mean of 4.2 x 10(11) platelets per collection. Bleeding was controlled in most of the patients who received transfusion with a mean rise in platelet count of 30.6 x 10(9)/L. Therapeutic leukapheresis were performed on 3 patients with chronic leukaemias. A mean of 2.53 x 10(11) cells were collected per run with a mean fall of 58.2 x 10(9)/L in the patients' white blood cell count. Plasmapheresis was used to treat 1 patient with multiple myeloma. The authors' experience demonstrates that cell separator support is essential for patients with bone marrow depression and that the therapeutic leukapheresis is effective therapy for selected patients with chronic leukaemias. Plasmapheresis is effective in patients with hyperviscosity syndrome.

Adult↗