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Biomedical subjects

V Fonseca

Publications and source records attributed to V Fonseca.

At least 73 records · Page 4Linked to original sources
PubMed1985

Thrombocytopenia and lupus-like anticoagulant in a patient with peripheral vascular disease: response to infusion of prostacyclin.

A 46 year old man with intermittent claudication due to severe peripheral vascular disease had a circulating lupus like anticoagulant (LLAC), thrombocytopenia (79 X 109/1), markedly reduced platelet survival and a normal bone marrow. He was treated with intravenous prostacyclin (PGI2) infusions which resulted in improvement of the patient's exercise tolerance and normalisation of his platelet count (300 X 109/1) and platelet aggregation could then be assessed. The platelets were markedly hyperaggregable and generated supranormal quantities of thromboxane A2. A diagnosis of consumptive thrombocytopenia secondary to peripheral vascular disease and platelet hyperaggregability was made. Despite therapy with aspirin and dipyridamole, gradual and progressive reduction in platelet count followed and his exercise tolerance declined over the next three months. Immunoglobulin prepared from the patient's serum did not inhibit vascular PGI2 synthesis in vitro. To our knowledge this is the first reported case of consumptive thrombocytopenia due to severe peripheral vascular disease and platelet hyperaggregability. PGI2 administration caused a transient resolution of these features which was not sustained by aspirin and dipyridamole.

Arteriosclerosis Obliterans↗
PubMed1984

Plasma creatinine and creatinine clearance in nutritional osteomalacia.

To confirm recent observations that some vitamin D deficient osteomalacic patients had low plasma creatinine concentrations, low urinary creatinine excretion, and a paradoxically low creatinine clearance, and whether these changes were due to vitamin D deficiency per se, these measurements were made in patients before and after vitamin D supplementation. The pretreatment levels were also compared with those in healthy controls and in non-osteomalacic patients without renal disease. The above changes were confirmed. After treatment with vitamin D, plasma creatinine concentrations rose, but urinary creatinine excretion and creatinine clearance did not alter. These data indicate the limitation of creatinine clearance as an index of renal function in vegetarian osteomalacic patients. Furthermore, they demonstrate the effect of vitamin D deficiency and its reversal on plasma creatinine concentrations.

Bone and Bones↗
PubMed1984

Exposure to sunlight and vitamin D deficiency in Saudi Arabian women.

Plasma 25-hydroxy cholecalciferol (25-OH vitamin D) concentrations were measured in 31 adult Saudi Arabian women who presented with acute minor illness. Patients with chronic diseases, malignancy and overt metabolic bone disease were excluded from this study. The median plasma 25-OH vitamin D concentration was 6 ng/ml (range: 2-18 ng/ml). Only three subjects had a concentration within the normal range (10-55 ng/ml). Plasma 25-OH vitamin D concentrations were significantly lower in subjects living in apartments than in those living in villas or rural areas (P less than 0.02). When direct questioning was used to assess exposure to sunlight, plasma 25-OH vitamin D concentrations were significantly lower in those subjects whose average exposure was less than 30 min daily than those whose exposure was more than 30 min daily (P = 0.002). Our findings confirm the importance of inadequate exposure to sunlight in the aetiology of vitamin D deficiency. Social customs may contribute to this deficiency in spite of abundant sunshine. Direct questioning to assess the adequacy of sunlight exposure is an essential part of history taking in cases of suspected vitamin D deficiency.

Adult↗