PubMed Health⌕ Search

Biomedical subjects

R P Ng

Publications and source records attributed to R P Ng.

At least 19 recordsLinked to original sources
PubMed1988

Comparative regimens for the ex vivo chemopurification of B cell lymphoma-contaminated marrow.

The success of autologous bone marrow transplantation for B cell lymphoma may depend on the efficacy of in vitro purification of patients' tumor cell-contaminated marrow. In this study, we tested the toxicity of seven different chemotherapeutic agents against two B cell lymphoma lines (LY-16 and SK-DHL-2) as compared to normal human bone marrow granulocyte-macrophage progenitor cells (CFU-GM). 4-Hydroperoxycyclophosphamide (4-HC), VP-16-213 (VP-16), nitrogen mustard, and vincristine showed a highly selective toxicity against cultured lymphoma cells; i.e., at doses sufficient to induce a 4-log clonogenic tumor cell reduction (4-HC 21 micrograms/ml, VP-16 50 micrograms/ml, nitrogen mustard and vincristine 5 micrograms/ml), 10.0 +/- 6.7, 3.0 +/- 3.2, 23.2 +/- 22.7 and 24.0 +/- 17.0% (mean +/- 1 SD), respectively, of normal bone marrow CFU-GM were preserved. The differential sensitivity of tumor cells and normal hematopoietic precursors was less prominent after exposure of cells to cis-diamminechloroplatinum II (cis-platinum); thus, at a drug dose of 100 micrograms/ml, all detectable lymphoma cells could be eradicated (i.e., greater than or equal to 4 log reduction) while a CFU-GM recovery of only 0.2 +/- 0.2% was observed. In contrast, adriamycin and bleomycin, at the highest tumoricidal concentrations tested (5 and 100 micrograms/ml, respectively) did not exhibit a selective toxicity toward lymphoma cell lines. In summary, our results suggest that nitrogen mustard and vincristine, as well as 4-HC and VP-16, may be useful agents for the ex vivo treatment of bone marrow grafts form B cell lymphoma patients.

Antineoplastic Agents↗
PubMed1985

Cross-sectional study of semen parameters in a large group of normal Chinese men.

Testicular size, semen characteristics and serum reproductive hormone levels were studied in 1239 normal Chinese men. The mean testicular size of 17 ml in this group of subjects was similar to other reports in Orientals but was smaller than that reported in Caucasians. Semen volume, and the sperm count, motility and morphology were comparable to those described for Caucasian subjects. The cervical mucus penetration test (Kremer's test) and the zona-free hamster egg penetration test were also studied in some of the subjects. Age showed a positive correlation with the serum levels of FSH and LH, which were highly correlated with each other. Sperm concentration and the total sperm count were positively correlated with testicular volume, the length of abstinence, the % of sperm with an oval head, and the zona-free hamster egg penetration test, but were negatively correlated with serum FSH. Sperm motility was negatively correlated with the duration of abstinence but was positively correlated with the % normal sperm. The results constitute a normal data base from Chinese men for comparison with studies in male infertility and fertility regulation.

Adult↗
PubMed1985

Warfarin versus dipyridamole-aspirin and pentoxifylline-aspirin for the prevention of prosthetic heart valve thromboembolism: a prospective randomized clinical trial.

In a prospective, randomized, parallel study, two regimens of platelet-suppressant therapy (PST)--dipyridamole-aspirin and pentoxifylline-aspirin--were compared with standard oral anticoagulation with warfarin in the prevention of prosthetic heart valve thromboembolism. In the entire group of 254 patients followed for 395.6 patient-years, the thromboembolic rate was significantly less in the warfarin group (warfarin vs dipyridamole-aspirin, p less than .005; warfarin vs pentoxifylline-aspirin, p less than .05). Subgroup analysis disclosed that, in patients with isolated mitral valve replacement, warfarin was superior to both of the PSTs with respect to the prevention of thromboembolism (warfarin vs dipyridamole-aspirin, p = .005; warfarin vs pentoxifylline-aspirin, p less than .05). Furthermore, a significant number of our patients could not tolerate the antiplatelet agents. However, in the rare situation in which repeated significant bleeding occurs despite careful adjustment of the dosage of warfarin, PST may be an acceptable alternate method of thromboembolism prophylaxis.

Adult↗
PubMed1984

Clinico-pathological features of malignant lymphomas in 294 Hong Kong Chinese patients, retrospective study covering an eight-year period.

The clinical records and histological material from 294 adult Chinese patients with malignant lymphoma were examined. These patients were first seen at the Queen Mary Hospital, Hong Kong, during the 8-year period 1975-82. There were 27 patients (9.2%) with Hodgkin's disease (HD) and 267 with non-Hodgkin's lymphoma (NHL). The median age at presentation was younger for HD (45 years) and the male: female ratio was higher (2:1) than the corresponding figures for NHL of 51 years and 1.4:1. In 76 patients (28.5% of NHL), the disease was thought to have originated in an extra-nodal site, 48 of these cases being gastrointestinal lymphomas. It was possible to reclassify 234 NHL according to the Rappaport and Kiel classifications, and the Working Formulation (WF) proposed by the US National Cancer Institute Study; for HD, the Rye classification was used in 26 cases where suitable material was available. Nodular/follicular lymphomas made up 17.1% of nodal NHL and 5.3% of extra-nodal NHL. The "histiocytic" (Rappaport) or large-cell (WF) subtype was the commonest amongst diffuse NHL. There were only four cases of Burkitt's lymphoma. For HD, the nodular sclerosing subtype was commonest in females (5 out of 8 cases) and for males, the commonest was mixed cellularity (10 out of 18 cases). Of patients with nodal NHL 64.7%, presented with Stage IV disease. For HD, there were about equal numbers of patients presenting with Stage II and Stage IV disease (10 and 9 respectively). The low incidence of Hodgkin's disease and of follicular lymphomas is comparable to figures from other "oriental" countries such as Japan.

Adolescent↗
PubMed1984

Tubular dysfunction in systemic lupus erythematosus.

20 patients with systemic lupus erythematosus undergoing renal biopsies had their tubular function assessed by maximal concentrating ability, maximal urinary acidification and fractional urinary excretion of beta 2-microglobulin. 80% of patients showed disturbances in one or more of the parameters tested with fractional beta 2-microglobulin excretion being most frequently abnormal. No correlation was found between the histological changes and functional disturbances.

Adolescent↗
PubMed1983

Can hypertransfusion attenuate myelosuppression associated with combination chemotherapy in patients with inoperable bronchogenic carcinoma? A report of a randomised, controlled study.

Based on the concept of "stem-cell competition," hypertransfusion has been shown to attenuate the leucopenia associated with chemotherapy in children with leukemia. We conducted a randomized, controlled study of hypertransfusion in 25 patients with inoperable lung cancer who received combination chemotherapy consisting of methotrexate, adriamycin, cyclophosphamide, and CCNU (Lomustine) (MACC scheme). Twelve patients in the hypertransfusion group were given red cell transfusion to a hemoglobin value greater than or equal to 17 gm/dl prior to each chemotherapy cycle. The two groups of patients were comparable in age, cell type, extent of disease, performance status, and initial hemoglobin level and blood counts. The mean fall in granulocyte count was greater for control group (3.76 X 10(9)/liter) than for hypertransfusion group (3.27 X 10(9)/liter), and the mean fall in platelet count was greater for control group (53.84 X 10(9)/liter) than for hypertransfusion group (35.83 X 10(9)/liter), although the differences did not reach statistical significance (p greater than 0.05) partly because our MACC scheme was probably not sufficiently myelosuppressive to bring about a difference in the two groups. Granulocytopenia-associated infections were infrequent in both groups: two episodes in 37 cycles of chemotherapy in the hypertransfusion group and three episodes in 43 cycles in the control group. Hypertransfusion was simple and safe, and the encouraging trend towards less marked myelosuppression in our hypertransfused group would warrant further studies using more intensive and myelosuppressive combination chemotherapy regimens.

Adult↗
PubMed1982

The diagnostic value of the ratio of serum gamma-glutamyl transpeptidase to alkaline phosphatase in alcoholic liver disease.

A prospective study of the initial liver laboratory tests was carried out in the following patients: 55 patients with alcoholic liver disease, 53 with cholangitis, 41 with hepatocellular carcinoma, 65 with acute viral hepatitis, and 49 with hepatitis-B surface antigen-positive chronic active hepatitis. There was considerable overlap in the levels of the serum gamma-glutamyl transpeptidase (GT) and alkaline phosphatase (AP) among the five groups. However, the ratio of GT to AP was significantly higher in the group with alcoholic liver disease than in any of the other four groups. When the ratio was higher than 1.4, the diagnostic efficiency for distinguishing the alcohol group from the other four groups was 78% (the normal upper limit for GT and AP being 35 and 115 U/1, respectively). A possible explanation for this higher ratio in alcoholic liver disease is suggested. We conclude that when the GT and AP is greater than 1.4, it is of greater diagnostic value than either variable alone in differentiating alcoholic from other liver diseases.

Alkaline Phosphatase↗
PubMed1980

Effect of combination chemotherapy on pituitary-gonadal function in patients with lymphoma and leukemia.

After at least four courses of intermittent chemotherapy, 14 of the 15 men with malignant lymphoma had elevated serum follicle-stimulating hormone (FSH). In three of these subjects, serial studies showed progressive increases in basal FSH and exaggerated FSH responses to luteinizing hormone releasing hormone (LHRH). Although gonadal biopsies were not done, this elevation of FSH is indicative of progressive and severe damage to the germinal epithelium by chemotherapy. Elevated leutinizing hormone (LH) was found in seven and decreased testosterone (T) in two of these subjects. Increased LH responses to LHRH stimulation were also found in the three subjects studied. These findings suggest that the testicular damage is not restricted to the germinal tissue. In four male subjects with acute myeloid leukemia treated by intermittent chemotherapy not containing any alkylating agents, FSH, LH, and T levels were normal. Three of the 4 female patients with malignant lymphoma and two with acute myeloid leukemia had normal basal, serial, and LHRH-stimulated FSH, LH, and estradiol (E2) levels. Elevated gonadotropins and low E2 were found only in subjects who had received abdominal irradiation.

Adult↗
PubMed1977

Disseminated varicella infection: treatment with transfer factor in a patient with Hodgkin's disease.

Treatment with transfer factor in a patient with disseminated varicella infection complicating stage IV Hodgkin's disease is described. The patient, a 24-year-old woman, showed transient clinical improvement and restoration of immune response to varicella-zoster antigen after receiving transfer factor. Though she later died from septicaemia, further trials of treatment of disseminated viral infection in patients with Hodgkin's disease with transfer factor are indicated.

Adult↗
PubMed1976

Mononuclear cells migration inhibition and delayed hypersensitivity in man.

The migration inhibition by soluble PPD of peripheral blood mononuclear cells showed a much better reflection of delayed hypersentitivity to tuberculin in man than the migration inhibition of buffy coat cells. The migration index (MI) with mononuclear cells in a group of tuberculin positive subjects was 0.51 +/- 0.14 (mean +/- S.D.) (n = 20) and that of a group of tuberculin negative subjects was 0.89 +/- 0.11 (n = 14) (P less than 0.001). Using buffy coat cells the MI was 0.65 +/- 0.26 (n = 19) for a group of tuberculin positive subjects and 0.76 +/- 0.24 (n = 10) for the group of tuberculin negative subjects. They were not significantly different (P greater than 0.05). The mononuclear cells migration inhibition was also quite reproducible from day to day.

Cell Migration Inhibition↗
PubMed1975

Transfer factor in Hodgkin's disease.

In a controlled studiy, six patients with stage-IV Hodgkin's disease were given transfer factor (T.F.) prepared from patients with Hodgkin's disease in long remission. There was an apparent increase in cell-mediated immune responses as evidenced by a significant increase in the recipients' lymphocyte responses to phytohaemagglutinin stimulation. Three out of six patients converted to positive delayed-hypersensitivity tests. These three all had the nodular sclerosing type of Hodgkin's disease. These results warrant the further investigation of the use of Hodgkin's disease-specific T.F. as a therapeutic agent in this condition.

Hodgkin Disease↗