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Biomedical subjects

M J Friedman

Publications and source records attributed to M J Friedman.

At least 127 records · Page 7Linked to original sources
PubMed1982

Thomas B. Quigley, M.D., and the meniscus.

Utilizing material from a registry of knee surgery, subsequent operations relating to meniscectomy were reviewed. The overall reoperation rate for the entire series was 30%; 6% of the patients eventually had at least the other meniscus removed. One out of ten had subsequent anterior stabilization with or without removal of the meniscus. Only 4% had an osteotomy, knee replacement or arthrodesis at a later date. Further and expanded studies may aid in further understanding the ultimate fate of meniscectomized knees. Longer follow-up examinations are required to evaluate the long term results following removal of the meniscus through the operative arthroscope.

Arthrodesis↗
PubMed1982

Fluphenazine blood levels and clinical response.

The radioreceptor assay for neuroleptics (NRRA) holds out great theoretical promise as a method for monitoring blood neuroleptic levels, but its practical value is yet to be established. In the present study, 12 psychotic patients were followed longitudinally during treatment with oral (n = 9) and/or depot (N = 7) fluphenazine. Neuroleptic blood levels were determined both by the NRRA and by high performance liquid chromatography utilizing an electrochemical detector (HPLC). Clinical status was monitored by the Brief Psychiatric Rating Scale. Although blood levels were near the limits of sensitivity, the NRRA was able to detect the drug in most samples. HPLC was able to detect fluphenazine in less than 20% of the samples. Detectable blood levels by HPLC were associated with high blood levels by the NRRA. There was a significant correlation between blood levels as measured by the NRRA and clinical improvement. This correlation appears to be independent of the dose or route of administration of fluphenazine. Many patients were followed for several months and a few for over a year. A remarkable constancy of blood levels was found, particularly with depot administration. Given these findings, the NRRA may be an important clinical tool for monitoring patients receiving fluphenazine.

Chromatography, High Pressure Liquid↗
PubMed1981

Complementary use of amperometric and spectrophotometric detection for concurrent monitoring of serum tryptophan metabolites by reversed-phase liquid chromatography.

We describe an improved reversed-phase liquid-chromatographic method for concurrent measurement of tryptophan and eight of its metabolites in serum. These were separated by gradient elution and detected both by ultraviolet absorption at 254 nm and amperometrically at an oxidation potential of +0.700 V vs Ag/Cl. Detection limits for the electrochemically-detected compounds were between 100 pg and 1.0 ng, and approximately 1-5 ng for the ultraviolet-absorbing compounds. Analytical recovery of the compounds after deproteinization (by ultrafiltration) varied between 65 and 95%. As little as 500 microL of serum is required. No interference(s) from other naturally occurring serum constituents were encountered. This highly sensitive method is relatively fast and offers a useful tool for diagnosis and treatment of diseases involving derangement in tryptophan metabolism.

Chromatography, High Pressure Liquid↗
PubMed1979

Ultrastructural damage to the malaria parasite in the sickled cell.

The process by which malaria parasites are killed in sickled erythrocytes was studied by electron microscopy. In vitro cultures of Plasmodium falciparum in sickle cell hemoglobin (HbS) homozygous (SS) and heterozygous (SA) red cells were deoxygenated for up to 6 h and fixed under anaerobic conditions. Parasites in SS cells appeared to be disrupted by intrusions of needle-like deoxyHbS aggregates; disintegration of cytoplasm and membranes followed. In SA red cells, the parasites were generally not disrupted. Instead, extensive vacuolization occurred, a sign of metabolic inhibition. The resistance of HbS gene carriers to malaria results partly from these causes of intracellular parasite death.

Anemia, Sickle Cell↗
PubMed1979

Two-dimensional echocardiography and B-mode ultrasonography for the diagnosis of loculated pericardial effusion.

Two cases of loculated pericardial effusion resulting in cardiac tamponade are presented. The loculated nature and extent of the effusion was best defined by two-dimensional echocardiography or B- mode ultrasonography. Cross-sectional images should probably be obtained in all cases of suspected loculated pericardial effusion and in patients in whom the interpretation of the M-mode echocardiogram is equivocal as to the presence or absence of pericardial effusion.

Adult↗
PubMed1979

The role of hemoglobins C, S, and Nbalt in the inhibition of malaria parasite development in vitro.

The host cell competence of hemoglobin C (HbC)-containing erythrocytes for Plasmodium falciparum was studied by in vitro culture. HbC homozygous red cells did not support the growth of the intracellular parasite. Heterozygous cells, however, were competent. In addition, HbC increased the resistance of sicle cell hemoglobin (HbS) red cells when present in the double heterozygote, SC, cultured at low oxygen tension. This effect most likely resulted from the ability of HbC to enhance the sickling of HbS-containing red cells. Oxygenated SC cells were indistinguishable from normal and AS cells in host cell competence. Another double heterozygote, SNBalt, showed decreased sickling and decreased resistance to malaria parasite growth. The evolutionary significance of these results is discussed.

Animals↗
PubMed1978

Erythrocytic mechanism of sickle cell resistance to malaria.

The physiological basis for the resistance to falciparum malaria individuals with sickle cell trait has not been understood. Recent advances in erythrocytic Plasmodium falciparum culture have made possible a direct investigation of the development of the malaria parasite in cells with sickle cell homoglobin. In a high (18%) oxygen atmosphere, there is no apparent sickling of cells, and the growth and multiplication of P. falciparum is identical in normal (AA), hemoglobin S homozygous (SS), and hemoglobin S heterozygous (SA) erythrocytes. Cultures under low (1-5%) oxygen, however, showed clear inhibition of growth. The sickling of SS red cells killed and lysed most or all of the intracellular parasites. Parasites in SA red cells were killed primarily at the large ring stage, probably as a result of a disruption of the parasite metabolism. Incubation in cyanate prior to culture reversed the resistance of SA erythrocytes to plasmodium growth, but had no effect on SS red cell sickling or resistance. Thus, the mechanism of resistance in vivo may be due solely to intraerythrocytic conditions.

Anemia, Sickle Cell↗
PubMed1978

Depression, hypertension, and serum dopamine-beta-hydroxylase activity.

Serum dopamine-beta-hydroxylase (DBH) activity was measured in a heterogeneous sample of 290 outpatients awaiting medical, surgical, or psychiatric appointments at a Veterans Administration Hospital. All patients were assessed for depressive symptomatology by the Zung Self-Rating Depression Scale (SDS) and for elevated diastolic blood pressure (BP greater than or equal to 90 mm Hg). Elevated DBH activity was associated with SDS scores greater than or equal to 60. No statistical association was found between DBH activity and diastolic BP. Two pharmacological agents, alpha-methyl-DOPA and minor tranquilizers, also were associated with significant alterations in serum DBH activity.

Adult↗