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Biomedical subjects

F Campbell

Publications and source records attributed to F Campbell.

17 recordsLinked to original sources
PubMed1992

T-lymphocyte responses to Pneumocystis carinii in healthy and HIV-positive individuals.

Pneumocystis carinii pneumonia (PCP) is a well-recognized cause of morbidity in patients with impaired T-cell function. In this study of cellular immunity to P. carinii, peripheral blood mononuclear cells from 25 HIV antibody-positive (HIV+) patients and 11 healthy individuals were stimulated in vitro with P. carinii antigen. The responding T-cell blasts were cocultured with autologous P. carinii antigen-pulsed macrophages to measure P. carinii-specific cytolytic T-lymphocyte activity (CTL). T-cell blasts from two healthy donors were used to generate P. carinii-specific clones by limiting dilution. T cells from HIV+ patients proliferated less to P. carinii antigen than T cells from healthy volunteers. In contrast, the level of specific cytotoxicity was identical in all groups when equal numbers of CTLs were used. Within the group of symptomatic patients, CTL activity was higher in those with a history of PCP (p = 0.033). Pneumocystis carinii antigen-specific T-cell clones proved to be CD4+ and MHC class II restricted; six of eight clones tested showed P. carinii-specific cytolytic activity. Cell-mediated immune response to P. carinii in healthy individuals include CD4+, class II MHC-restricted T cells with P. carinii-specific cytotoxicity. There is an increasing loss of P. carinii-specific proliferative responses in HIV+ patients as disease progresses, but a cytotoxic response is still detected in the absence of proliferation.

Adolescent↗
PubMed1990

Intraoperative management of patients with heparin-induced thrombocytopenia.

For 11 patients with confirmed heparin-induced thrombocytopenia, we used reversible platelet inhibition with iloprost, a stable prostacyclin analogue, to permit safe heparin administration for cardiac (n = 9) or vascular (n = 2) operations. In vitro, iloprost (0.01 mumol/L) prevented both heparin-induced platelet aggregation and 14C-serotonin release in all patients. Therefore, intraoperatively, a continuous infusion of iloprost was started before administration of heparin and was continued until 15 minutes after administration of protamine. For cardiac patients, after heparin administration, the whole blood platelet count did not change (171,000 +/- 29,000/microL versus 174,000 +/- 29,000/microL, mean +/- standard error of the mean); no spontaneous platelet aggregation was observed, and plasma levels of the alpha-granule constituents platelet factor 4 and beta-thromboglobulin increased from 38 +/- 14 and 140 +/- 18 ng/mL to 591 +/- 135 and 235 +/- 48 ng/mL, respectively. Fibrinopeptide A levels actually decreased from 287 +/- 150 to 27 +/- 6 ng/mL. Furthermore, adenosine diphosphate-induced platelet activation was preserved, postoperative bleeding times were unchanged, and no heparin-related deaths occurred. Similar results were obtained in both vascular patients. We conclude that temporary platelet inhibition with iloprost now permits safe heparin administration in all patients with heparin-induced thrombocytopenia who require a cardiac or vascular operation.

Adult↗
PubMed1990

Neonatal hypothyroidism: comparison of radioisotope and ultrasound imaging in 54 cases.

Fifty-four neonates with congenital hypothyroidism identified by the North East and North West Thames Regional hypothyroid screening programme between January 1985 and December 1987 were investigated with radioisotope (Tc99m) and ultrasound scans of the thyroid before treatment with 1-thyroxine was commenced. Compared with the radioisotope scans, ultrasound identified normally sited thyroid tissue in only 7 out of 10 cases, and ectopic thyroid tissue in only 5 out of 26 cases. Three out of 18 cases with no isotope uptake in the neck appeared to have normally sited tissue on ultrasound scan. We conclude that in our hands ultrasound of the neck is of only limited value in the assessment of young infants with congenital hypothyroidism.

Congenital Hypothyroidism↗
PubMed1987

Exchange-transfusion with pyridoxalated polymerized hemoglobin: effects on liver PO2.

To examine the efficacy of modified stroma-free hemoglobin in maintaining liver PO2, rats were exchange-transfused to hematocrit 10% using pyridoxalated polymerized hemoglobin (plp-polyHb, 10-12 g/dl) prepared from crystalline Hb. Following hemodilution, plasma Hb was 7.4 g/dl, and rats were normotensive. Mean liver PO2 was 3.4 vs 23.3 mm Hg in sham-exchanged controls. Other rats, hemodiluted similarly with 6% albumin or hydroxyethylstarch, were hypotensive and died. At 24 hours plasma Hb was 2.0 g/dl, indicating an intravascular half-life of approximately 16 hours. Hepatic PO2 was 12.4 vs 26.8 mm Hg in nonhemodiluted controls. Data provided by clearance of low-dose indocyanine green suggested reduced plasma volume and depressed liver blood flow. Scattered foci of midzonal hypoxic damage were observed in liver lobules. The basis for hypoxic injury is considered to be due in part to the acute restriction of oxygen supply induced by exchange-transfusion with plp-polyHb. The rate of loss of intravascular hemoglobin and diminished plasma volume could have contributed to oxygen insufficiency as well. Endotoxin present in the plp-polyHb was not a factor.

Animals↗
PubMed1984

Nephrosonography and renal scintigraphy in evaluation of newborn with renomegaly.

Prompt diagnosis of renomegaly in the newborn is necessary for appropriate medical or surgical management to insure maximal recovery of renal function. To investigate both renal structure and function without iodinated contrast infusion, combined ultrasonography and nuclear scintigraphy were evaluated in 17 newborns with renomegaly and 6 infants with cystic renal abnormalities detected in utero. In 18 patients, intravenous pyelography (IVP) and/or voiding cystourethrography (VCUG) were performed subsequently. While ultrasonography or scintigraphy alone provided the major diagnosis in 48 per cent and 30 per cent of cases, respectively, the combination of both studies yielded the major diagnosis in 87 per cent. Subsequent IVP was less informative than combined sonography and scintigraphy in 5 of 15 patients, and VCUG confirmed the final diagnosis in 4 of 13 patients. We conclude that initial evaluation of the newborn with renomegaly should comprise ultrasonography followed by nuclear scintigraphy. This combination of studies provides adequate information to determine subsequent management in nearly 90 per cent of cases without subjecting infants to the risks of contrast infusion or higher doses of diagnostic levels of radiation.

Female↗
PubMed1984

Prognostic factors in neonatal acute renal failure.

Sixteen infants, 2 to 35 days of age, had acute renal failure, a diagnosis based on serum creatinine concentrations greater than 1.5 mg/dL for at least 24 hours. Eight infants were oliguric (urine flow less than 1.0 mL/kg/h) whereas the remainder were nonoliguric. To determine clinical parameters useful in prognosis, urine flow rate, duration of anuria, peak serum creatinine, urea (BUN) concentration, and nuclide uptake by scintigraphy were correlated with recovery. Nine infants had acute renal failure secondary to perinatal asphyxia, three had acute renal failure as a result of congenital cardiovascular disease, and four had major renal anomalies. Four oliguric patients died: three of renal failure and one of heart failure. All nonoliguric infants survived with mean follow-up serum creatinine concentration of 0.8 +/- 0.5 (SD) mg/dL whereas that of oliguric survivors was 0.6 +/- 0.3 mg/dL. Peak serum creatinine concentration did not differ between those patients who were dying and those recovering. All infants who were dying remained anuric at least four days and revealed no renal uptake of nuclide. Eleven survivors were anuric three days or less, and renal perfusion was detectable by scintigraphy in each case. However, the remaining survivor (with bilateral renal vein thrombosis) recovered after 15 days of anuria despite nonvisualization of kidneys by scintigraphy. In neonates with ischemic acute renal failure, lack of oliguria and the presence of identifiable renal uptake of nuclide suggest a favorable prognosis.

Acute Kidney Injury↗
PubMed1975

Ultrastructure of the sinus wall of murine bone marrow in myelogenous leukemia.

The ultrastructure of bone marrow of RF mice having an acute myelogenous leukemia induced by inoculation with leukemic cells was investigated. In several respects sinuses of leukemic marrow are similar to normal marrow. Sinuses are present in numbers approximating that of the normal; the lining cells of the sinus wall have organelles similar in distribution and number to those of normal lining cells; the sinus wall is continuous, having openings only in conjunction with blood cells that are migrating through it (migration pores); migration pores occur within and not between lining cells. Abnormalities observed in leukemic marrow are the occurrence of virus-like particles in leukemic cells, the presence of numerous particles 300 to 500 A in diameter in the extracellular space, reduction in the number of adventitial cells of the sinus wall and an increase in the thickness and distribution of extracellular material located near the basal surface of lining cells.

Animals↗
PubMedDate not supplied

Aids and equipment for the disabled in the community.

The redefinition of disability from a medical problem inherent in the individual, to a socially constructed problem affected by the world in which that individual lives, has led to an emphasis and exploration of the interrelationship between disease/disorder, impairment, disability and handicap. It is clear that those who are disabled do not necessarily need to be handicapped by their disability. One method of professional intervention designed to prevent disability becoming a handicap and to promote independence is the provision of aids and equipment. Despite its evident importance it appears that the provision of aids and equipment in the community is poorly co-ordinated, complex and time-consuming. Some of the reasons for this are examined in this paper. Key themes that are addressed include the legislative framework, the conceptual confusion arising from poorly defined terms, the link between health and social services, the consumer perspective, and wastage.

Community Health Nursing↗
PubMedDate not supplied

Deferoxamine for the treatment of hemosiderosis during CAPD.

The effects of chelation therapy by intravenous and intraperitoneal administration of deferoxamine were compared during maintenance continuous ambulatory peritoneal dialysis (CAPD) in a child with end stage renal disease and hemosiderosis. We demonstrate that intraperitoneally administered deferoxamine is safer, more practical and efficient than weekly intravenously administered deferoxamine for the treatment of iron overload in the pediatric patient undergoing CAPD.

Adolescent↗