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Biomedical subjects

D Merzbach

Publications and source records attributed to D Merzbach.

At least 73 records · Page 4Linked to original sources

Comparative study of the endotoxin-stimulated nitroblue tetrazolium test in disease and health.

Endotoxin-stimulated nitroblue tetrazolium (NBT) reduction was evaluated in 853 individuals: 270 healthy controls, 334 with various non-neoplastic conditions, 220 with solid non-lymphomatous tumours, and 29 with lymphoma. Each of the above groups was divided into three age subgroups: less than 60, 60-69, and greater than or equal to 70 years. In the controls and in patients with nonmalignant diseases, significantly lower values were recorded for elderly subjects (greater than or equal to 60 years) compared with younger subjects of the same group, whereas in cancer patients the results were independent of age. Under the age of 60, stimulated values for both patient groups were significantly lower than the control values, and in patients with solid non-lymphomatous tumours significantly lower values were attained than in the other patients. NBT reduction in lymphoma patients was comparable to that of the controls. In the elderly (age greater than or equal to 70) no significant differences were noted between patients and controls. It is suggested that stimulated NBT reduction declines with advancing age. While this test clearly demonstrates some leucocyte dysfunction in solid cancer, its value in investigating neutrophil behaviour in elderly subjects is questioned.

Adult↗

Neutrophil function in cured cancer patients.

Spontaneous and endotoxin-stimulated nitroblue tetrazolium (NBT) dye reduction was evaluated in 86 individuals cured of various types of solid malignancies and in 55 healthy adults. Oxygen consumption tests, at rest and during phagocytosis, were performed with polymorphonuclear leukocytes of 22 patients and 10 controls, chosen at random. The results revealed an impaired capacity of patients' neutrophils to reduce NBT. The decrease in the stimulated reduction values was more pronounced (p less than 0.0005) than in spontaneous values (p less than 0.01), and was also noticed in patients who had been treated by surgery alone and in those with a disease-free interval of 10 years or more. Oxygen consumption by patients' leukocytes was similar to that of controls. The present results, especially those of the endotoxin-stimulated NBT test, might reflect a neutrophil dysfunction in cured cancer patients. The nature of such an abnormality and its possible clinical implication are still obscure.

Adult↗

Spontaneous and stimulated nitroblue tetrazolium tests of leukocytes from patients with solid malignant tumors.

Histochemical nitroblue tetrazolium (NBT) reduction tests, spontaneous and endotoxin-stimulated, were performed on samples of blood from 202 adult patients with solid neoplastic tumors and 37 healthy control subjects. The patients were classified according to activity of the disease, chemotherapy, and presence of bacterial infection. The NBT test did not prove helpful in detecting the latter condition in these patients. Low median spontaneous reduction values were recorded for patients with active malignancies, or receiving chemotherapy, compared with controls or cured patients without chemotherapy. Stimulated reduction values were significantly lower for all groups of patients than for controls, although for those apparently cured and untreated, stimulated reduction attained significantly higher values than for the other patients. A leukocyte dysfunction caused by both the underlying disease and its chemotherapy is assumed, and the usefulness of the endotoxin-stimulated NBT reduction test in detecting this dysfunction is stressed.

Adult↗

Polymorphonuclear leucocyte function in Behçet's disease.

Polymorphonuclear leucocyte function was investigated in 19 patients with active Behçet's disease. Spontaneous free leucocyte migration was found to be significantly reduced, yet after stimulation the leucocyte's chemotactic activity was considerably increase (p less than 0-05) when compared to control leucocytes. Control leucocytes migrated more rapidly when incubated in serum taken from patients with Behçet's disease (p less than 0-005). The enhanced chemotactic activity in Bechçet's disease appears to be due to both serum and intrinsic leucocyte factors. Spontaneous nitroblue tetrazolium reduction was found to be normal, although after stimulation leucocyte nitroblue tetrazolium reduction was lower than in the control group (P less than 0-025), as was leucocyte oxygen utilisation. It is suggested that the hyperreactive cellular inflammatory response that characterises Behçet's disease may be due to increased chemotactic activity and minor alterations in functional metabolic activity of leucocytes.

Adult↗

Effect of calcium ions on growth and metabolism of Saccharomyces carlsbergensis.

Addition of calcium ions increased 2- to 3-fold the growth of Saccharomyces carlsbergensis 2I in a minimal glucose-containing medium. The minimal concentration enhancing growth was 25 to 50 mug/ml CaCl2. Other divalent and trivalent cations tested, except for strontium ions, did not duplicate the calcium effect. Actively growing and dividing cells took up 45Ca2+, while resting yeast cells did not. The radiocalcium taken up was incorporated into newly synthesized structural material, presumably into the membrane protein.

Barium↗

Nocardiosis in Israel. A report of five cases.

Five cases of Nocardia infection are briefly described, four due to Nocardia asteroides and one to N. brasiliensis. The latter represents the first reported case of N. brasiliensis infection in Israel. In three of the patients, the infections were associated with an underlying disease process and with prolonged high-dosage therapy with steroids and/or cytotoxic drugs. In the other two patients, the disease was spontaneous.

Adult↗

Standardisation of the nitroblue-tetrazolium test.

Optimal conditions for the NBT-reduction test have been sought. Increasing heparin concentrations up to 100 units per ml and a delay in performance of the test, especially when blood specimens are kept at room temperature, resulted in higher values for the NBT index, which then sometimes exceeded the upper limit of normal in healthy people and in uninfected patients. The effect of pH, composition of the buffer, and dye concentration was also investigated. Phosphate-buffered saline pH 7-2 containing 0-1% NBT dye, without glucose, gave the most reliable results. In endotoxin-stimulated NBT tests, the following procedure is recommended: incubation of 0-1 ml whole blood with lyophilised endotoxin 20 mug per ml. for 15 min. in a 37 degree C water bath, followed by the standard test with a 0-2% NBT solution. By this technique, the leucocyte reaction to various types of lipopolysaccharides was of the same order of magnitude. Drug therapy having an effect on blood components lowered this reaction, whatever the source of endotoxin used as stimulant. The importance of NBT-reduction tests is discussed. Standard conditions of test performance are strictly requisite if comparable results are to be obtained and if data not corresponding with the apparent clinical and other laboratory findings are to be evaluated correctly. The stimulated NBT test, performed in parallel with the standard test, is useful in the interpretation of abnormal results and in the detection of factors with a temporary or permanent effect on the phagocytic activity of pmn leucocytes.

Agglutination↗

Endocarditis caused by Rhodotorula successfully treated with 5-fluorocytosine.

A 7-year-old boy suffering from aortic regurgitation and mitral stenosis and regurgitation was admitted with endocarditis caused by Rhodotorula pilimanae and was treated successfully with orally administered antifungal agent, namely 5-fluorocytosine (5-FC). A dose of 100 mg per kg body weight, divided into four equal parts, was prescribed. After a prolonged febrile period his temperature dropped to normal on the fourth day of 5-FC therapy. Review of the published reports disclosed few cases of endocarditis due to Rhodotorula spp. and this case seems to be the first treated with 5-FC. Follow-up in one year, after discharge from the hospital, revealed no evidence of relapse.

Administration, Oral↗