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Biomedical subjects

M N Stein

Publications and source records attributed to M N Stein.

12 recordsLinked to original sources
PubMed1984

Cholestatic liver dysfunction after long-term phenytoin therapy.

Cholestatic jaundice developed in a 64-year-old woman who had received phenytoin sodium for more than 40 years. Discontinuation of phenytoin therapy resulted in resolution of the hepatic abnormalities, which recurred on rechallenge, strongly suggesting a causal relation to the drug. Phenytoin therapy was discontinued again, with complete resolution of the hepatic abnormalities. The liver biopsy specimen obtained during therapy showed cholestasis compatible with obstruction of the biliary tree, although an obstructive process was never demonstrated. The biochemical abnormalities and histologic features observed most likely represent an unusual response to phenytoin therapy.

Chemical and Drug Induced Liver Injury↗
PubMed1981

Pulmonary embolism in patients with acute leukemia and severe thrombocytopenia.

While pulmonary thromboembolism has been reported in patients with acute leukemia complicated by severe thrombocytopenia, it has been studied infrequently and its pathogenesis remains imprecisely understood. Findings of 80 consecutive autopsies of patients with acute leukemia showed that three had pulmonary thromboembolism. All three patients had been severely thrombocytopenic and had received numerous platelet transfusions. Serial sections of thrombi were evaluated with electron microscopy. In no instance were platelet aggregates detected. However, Candida organisms were prominent in thrombotic specimens from each patient. These findings suggest that thromboembolism in such patients may involve occult fungal infection. Because pulmonary thromboembolism can complicate the course of acute leukemia and severe thrombocytopenia, it should be considered when clinical data suggest its occurrence.

Acute Disease↗
PubMed1969

Laser microscope irradiation of Physarum polycephalum: dynamic and ultrastructural effects.

Streaming plasmodia of Physarum polycephalum were irradiated with a microscope-mounted ruby laser and the resulting changes were recorded by cinemicrography or streak photographs. Some lesions were processed for electron microscopy. By varying the incident energy, three levels of response were detected. Two transient responses, a gelation briefly blocking streams and a more severe gelation with contraction, changed movement patterns but not organelle ultrastructure. At higher energies, a permanently coagulated lesion was rapidly segregated from normal and transiently altered cytoplasm by formation of new membranes. Within the coagulum, pigment granules were destroyed, membranes were disrupted, and cytoplasm was flocculent. Nuclei and mitochondria were compact in the center and swollen in a peripheral space left by contraction of the coagulum. These changes are probably caused by heat produced by the interaction between the laser beam and the pigment granules of the plasmodium. Many of the changes seem to be secondary responses that follow the primary capture of energy during irradiation.

Cell Nucleus↗
PubMedDate not supplied

Function and morphology of platelets produced for transfusion by intermittent-flow centrifugation plateletpheresis or combined platelet-leukapheresis.

The effects on platelet function of intermittent-flow centrifugation pheresis were measured employing platelets collected from ten donors by combined platelet-leukapheresis with hydroxyethyl starch (LP) and from ten by plateletpheresis (PP) by similar techniques except without starch. Greater numbers of platelets were produced by LP than by PP. Aggregation of platelets collected by both LP and PP was normal (did not differ from prepheresis baseline) to collagen and to 10(-5)M adenosine diphosphate (ADP). Slight impairment to aggregation with 2 X 10(-6)M ADP and 5.5 X 10(-5)M epinephrine occurred with both techniques. These abnormalities, however, were significantly less severe in platelets collected by LP. Platelet morphology by electron microscopy was nearly normal, although glycogen granules were absent in LP platelets. Thus, hydroxyethyl starch, at doses currently used during a single LP, does not enhance abnormalities of platelet aggregation over those expected to result from PP alone. Actually, LP platelets function better in vitro than those collected by PP. Large numbers of platelets can be harvested by LP, and their use as a component that is comparable to PP platelets may mean improved efficiency and reduced costs for pheresis centers.

Adenosine Diphosphate↗