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Biomedical subjects

J M Nelson

Publications and source records attributed to J M Nelson.

At least 91 records · Page 5Linked to original sources
PubMed1984

Neonatal exchange transfusions complicated by transfusion-induced malaria.

Two neonates who became infected with Plasmodium vivax subsequent to exchange transfusion are described. This complication of neonatal exchange transfusion is unusual in that only two other similar cases have been reported to the Centers for Disease Control. Although malaria is an unusual complication, it should be kept in mind when considering the differential diagnoses of fever following neonatal exchange transfusion. The risk of transfusion-induced malaria may be increasing due to the influx of immigrants from areas endemic for malaria. Careful blood donor selection and blood donor education may minimize this risk.

Diagnosis, Differential↗
PubMed1984

Serologic and biochemical studies of a previously unclassified blood type B variant.

The designation B4 is proposed for a weak variant of type B blood found in a Salvadorian woman and her two daughters. The red cells were weakly agglutinated by anti-B and anti-A,B; the serum contained anti-B; and the saliva contained H but not B substance. Biochemical studies of the serum showed that the enzyme specified by the variant B gene had low activity and low affinity for both sugar donor and acceptor.

ABO Blood-Group System↗
PubMed1984

Anticancer activity of the structurally novel antibiotic Cl-920 and its analogues.

Cl-920 is a structurally novel phosphate ester antibiotic that contains an unsaturated lactone and a conjugated triene system. It has potent antileukemic activity in mice. At doses of 25 mg/kg given i.p. once daily for 5 days to mice bearing approximately 10(7) L1210 leukemia cells, Cl-920 is curative in about 10% of the mice. Life span increases in noncured mice are typically in excess of 150%. The unsaturated lactone and phosphate ester moieties are required for activity against L1210 leukemia. Ring hydroxylation or removal of the terminal hydroxyl group have only modest effects on activity. Schedule studies suggest that prolonged exposure to low levels of Cl-920 is considerably more toxic than is daily or intermittent administration. Daily administration produces optimal activity against L1210 leukemia. Administration i.p. and i.v. of Cl-920 produce roughly equal toxicity and equal activity against an i.p. implant of L1210 leukemia. Cl-920 is inactive when given p.o. or s.c. Cl-920 failed to show confirmed activity against the following tumors in mice: M5076 sarcoma, B16 melanoma, and Ridgway osteogenic sarcoma. The lack of solid tumor activity in mice may be caused by a transport deficiency similar to that found with methotrexate.

Alkenes↗
PubMed1982

The promise of satellite clinics.

A community hospital has developed a successful model for establishing affiliated primary care centers in semirural areas without the use of federal or foundation money. Unique features of the program include funding through community stock sales and ultimate control by a community board of directors. Additional features include the establishment of a for-profit, wholly owned subsidiary of the hospital; development of a complete range of planning, management, and recruitment services; retention of freedom of choice for referrals and hospitalizations by both patients with physicians; and a but-our provision for the physicians.

Capital Financing↗
PubMed1980

Midgut carcinoid tumor with carcinoid heart disease. Its presence in the absence of hepatic metastases--a case report.

A 56-year-old man with a midgut carcinoid tumor had extensive metastatic involvement of lymphatic spaces and carcinoid heart disease. Unlike similar previously reported cases with carcinoid heart disease, hepatic metastases and history of the carcinoid syndrome were absent in this patient. Tumor involvement of cardiac lymphatic spaces may have been responsible for the development of carcinoid heart disease due to a local fibrogenic effect similar to the extensive fibrosis associated with tumor seen within the abdominal cavity at autopsy.

Heart Neoplasms↗
PubMed1978

Biopterin. III. Purification and characterization of enzymes involved in the cerebral synthesis of 7,8-dihydrobiopterin.

Three specific enzymes are involved in the cerebral synthesis of 7,8-dihydrobiopterin from GTP. These were isolated, purified, and characterized. The first enzyme, also catalyzing the rate-limiting step, is GTP-cyclohydrolase A-I or Mg2+-dependent A-II, which hydrolyze the GTP to the specific product 2-amino-6-(5-triphosphoribosyl)-amino-5-or-6-formamido-6-hydroxypyrimidine (FPyd-P3). FPyd-P3 is cyclized by a synthetase to D-erythro-7,8-dihydroneopterintriphosphate (NPTH2-P3). The new enzyme, D-erythro-7,8-dihydroneopterintriphosphate synthetase (enzyme B) is a basic protein of 9177 daltons containing three free SH groups, isoleucyl-seryl- as N- and valyl-glutamyl- as C-terminals. This enzyme of 69 amino acid residues from rat and 68 residues (one less aspartic acid) from guinea pig brain contains no hydroxyproline, methionine, or tryptophan. The enzyme from rat brain will gradually convert its product NPTH2-P3 to BH2, wherease the enzyme from guinea pig brain lacks this property. 2,4-amino-6-hydroxypyrimidine and dFPyd-P3 are effective inhibitors of this enzyme. The synthesis of BH2 from NPTH2-P3, but not from 7,8-dihydroneopterin, is catalyzed by L-erythro-7,8-dihydrobiopterin synthetase (enzyme C), which was purified to electrophoretic purity. This enzyme does not require pyridine nucleotides of Mc2+ for its catalysis.

Alcohol Oxidoreductases↗
PubMed1976

A performance-based method of student evaluation.

A method of medical education has been developed which emphasizes audit of student performance in terms of behavioural traits (thoroughness, reliability, analytic sense, and efficiency) rather than in terms of memorized knowledge. This method is dependent upon the Problem-Oriented Medical Record. The tools developed for the audit and some preliminary results are presented.

Behavior↗