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Biomedical subjects

F J Milne

Publications and source records attributed to F J Milne.

At least 19 recordsLinked to original sources
PubMed1992

Platelet and erythrocyte Mg2+, Ca2+, Na+, K+ and cell membrane adenosine triphosphatase activity in essential hypertension in blacks.

OBJECTIVE: To assess the relationship between intracellular Mg2+, Ca2+, Na+ and K+ and cell membrane adenosine triphosphatase (ATPase) activity in normotensive and hypertensive blacks. DESIGN: Intracellular cations and cell membrane ATPase activity were studied in black patients with untreated essential hypertension and age-, weight- and height-matched normotensive controls. Platelet, erythrocyte and serum Mg2+, Ca2+, Na+ and K+ levels as well as platelet and erythrocyte membrane Na+,K(+)-ATPase, Ca(2+)-ATPase and Mg(2+)-ATPase activities were measured in all subjects. METHODS: Intracellular Na+ and K+ were measured by flame photometry and Mg+ and Ca+ by atomic absorption spectrophotometry. Cell membrane ATPase activity was determined by a colorimetric method. RESULTS: The hypertensive group consistently demonstrated depressed activity of each ATPase studied, with significantly lower serum Mg2+, serum K+, erythrocyte Mg2+ and platelet Mg2+ levels compared with the normotensive group. Platelet Na+ and Ca2+ and erythrocyte Ca2+ were significantly elevated in the hypertensive group. In the hypertensive group, mean arterial pressure (MAP) was inversely correlated with platelet and erythrocyte membrane Na+,K(+)-ATPase, Ca(2+)-ATPase and Mg(2+)-ATPase. Serum Mg2+, serum Ca2+ and platelet Mg2+ were negatively correlated with MAP in the hypertensive group whilst erythrocyte and platelet Ca2+ were positively correlated. In the normotensive group, platelet Mg2+ and MAP were negatively, and erythrocyte Ca2+ and MAP, positively correlated. CONCLUSIONS: Black patients with essential hypertension have widespread depression of cell membrane Na+,K(+)-ATPase, Ca(2+)-ATPase and Mg(2+)-ATPase activities with serum and intracellular Mg2+ depletion and cytosolic Na+ and Ca2+ overload, which may reflect an underlying membrane abnormality in essential hypertension. These cellular abnormalities may be related to the defective transport mechanisms that in turn may be aggravated by Mg2+ depletion.

Black People↗
PubMed1992

Intracellular Mg2+, Ca2+, Na2+ and K+ in platelets and erythrocytes of essential hypertension patients: relation to blood pressure.

Alterations in intracellular cation metabolism have been implicated in the pathophysiology of essential hypertension. Total magnesium, calcium, sodium and potassium levels were studied in serum erythrocytes and platelets, from 154 subjects (76 hypertensive and 78 normotensives; 104 blacks and 50 whites). In the combined black and white hypertensive group, platelet sodium and calcium and erythrocyte calcium were elevated and serum potassium, serum magnesium and platelet magnesium decreased. In the black hypertensive patients, platelet sodium and calcium and erythrocyte calcium were increased, whereas serum magnesium, serum potassium, platelet magnesium and erythrocyte magnesium were decreased. In the white hypertensive group, platelet sodium and erythrocyte calcium were raised and platelet magnesium was decreased. In the black hypertensive patients, serum and platelet magnesium and serum calcium were negatively and erythrocyte and platelet calcium positively correlated with mean arterial pressure. In the white hypertensive patients platelet sodium was directly related to mean arterial pressure. These results suggest that intracellular sodium and calcium overload and magnesium depletion may be important in the pathophysiology of hypertension. Magnesium disturbances are more consistent and widespread in black hypertensive patients than in white hypertensive patients.

Adult↗
PubMed1991

Altered cations and muscle membrane ATPase activity in deoxycorticosterone acetate-salt spontaneously hypertensive rats.

The role of ions and cell membrane function in the pathogenesis of benign and malignant hypertension was investigated in spontaneously hypertensive rats (SHR). Ten-week-old male SHR (n = 50) and SHR treated with deoxycorticosterone acetate (DOCA; n = 70) and 1% NaCl drinking water were studied weekly for 14 weeks. Malignant hypertension developed only in DOCA-salt SHR and was characterised by severe hypertension, failure to thrive and renal fibrinoid necrosis. Fourteen DOCA-salt SHR and one SHR died. Extracellular (serum) and intracellular (erythrocyte and muscle) Na+, K+, Mg2+, Ca2+ and muscle membrane Na+,K(+)-adenosine triphosphatase (ATPase), Ca(2+)-ATPase and Mg(2+)-ATPase were measured at various stages in the development of malignant hypertension. Three developmental phases were defined: benign, premalignant and malignant. DOCA-salt SHR showed persistent hypokalaemia. In the benign phase, there were no differences in Na+, Mg2+ and Ca2+ between SHR and DOCA-salt SHR. In the premalignant phase, serum and erythrocyte Mg2+ and ATPase activity were significantly lower in DOCA-salt SHR compared with SHR. During the late premalignant and malignant phases, intracellular Ca2+ and Na+ were significantly higher in the DOCA-salt SHR compared with SHR. In view of these findings, the abnormalities in DOCA-salt SHR during the early phases of blood pressure elevation could be contributory factors to the development of malignant hypertension.

Adenosine Triphosphatases↗
PubMed1991

A method for determining the total magnesium, calcium, sodium and potassium contents of human platelets.

Platelet levels of magnesium, calcium, sodium and potassium may provide a better index of intracellular cations or total body ion status than serum, erythrocyte or leukocyte cation concentrations. A method is described for the determination of the total magnesium, calcium, sodium and potassium contents of human platelets. The method involves platelet isolation, repeated washing, lysis and measurement of the ions in the lysate. Magnesium and calcium were determined by atomic absorption spectroscopy and sodium and potassium by flame photometry. Platelet total potassium, magnesium, calcium and sodium were 4.5 +/- 1.5, 2.3 +/- 0.6, 1.8 +/- 0.5, 1.5 +/- 0.6 mumol/1 x 10(8) cells, respectively (means +/- SD). The method is simple, repeatable and accurate.

Adult↗
PubMed1979

Bilateral pleural effusions associated with generalized primary lymphoedema and erysipelas. A case report and the probable pathogenesis.

A case of bilateral pleural effusion in association with generalized primary lymphoedema and erysipelas, but without yellow dystrophic nails, is reported and the probable pathogenesis of the condition discussed. It is known that the primary defect lies in decreased lymphatic drainage. However, the consequent intravascular hypovolaemia and secondary hyperaldosteronism have not previously been demonstrated.

Adult↗
PubMed1979

Bone disease in patients on maintenance haemodialysis using softened or de-ionized water.

A clinical, biochemical and radiological study was carried out in 28 patients on maintenance haemodialysis in order to assess the prevalence of bone disease, particularly with regard to osteomalacia and/or osteopenia. The patients were selected from dialysis units using softened or deionized water, and the aluminium levels measured in the different water supplies. The results showed that symptomatic osteomalacia/osteopenia occurs more frequently in the units using softened water, which has a higher aluminium content, than in the de-ionized water unit. The patients dialysed on softened water also have significantly higher serum calcium and phosphorus levels. It is suggested that in Johannesburg, water softening alone is inadequate, and that the high aluminium levels in our water may be responsible for accelerated osteomalacia/osteopenia.

Adult↗
PubMed1979

Asymptomatic arsine nephrotoxicity. A case report.

A completely asymptomatic patient with arsine nephrotoxicity is described. The light and electron microscopic appearances of the kidney biopsy specimen are documented. The pathogenesis of the lesions, the usual manifestations of arsine exposure, and how these differed from those seen in our patient, are discussed.

Acute Kidney Injury↗
PubMed1979

A precursor role for DHA in a feto-placental unit for oestrogen formation in the mare.

Plasma levels of total oestrogens and dehydroepiandrosterone (DHA) were measured by radioimmunossay in samples taken from various blood vessels in both maternal and fetal compartments in 11 Pony mates. High concentrations of oestrogens (greater than 100 ng/ml of plasma), expressed as oestrone equivalents, were found in the fetal circulation. On both the fetal and maternal sides, oestrogen concentrations were lower in blood going to than from the placenta. DHA concentrations, on the other hand, were higher in blood flowing to the placenta from the fetus. The fetal gonads were seen as the source of DHA, which was present in remarkably high concentrations (greater than 800 ng/ml of plasma) in venous samples from fetal ovaries and fetal testes. A precursor role in placental oestrogen formation is suggested for DHA secretion by the fetal gonads.

Animals↗
PubMed1978

Acute renal failure after use of radiographic contrast media.

The nephrotoxic effects of radiographic contrast media (RCM) used for excretory urography and angiography are described in 9 patients. These effects are usually temporary and reversible, but may be permanent. Predisposing factors resulting in renal damage are identified and discussed. These include diabetes, dehydration, myelomatosis, chronic renal failure of many causes and repeated administrations of contrast media with a short period. Suggestions are made in order to reduce the incidence and severity of functional renal impairment after administration of contrast media.

Acute Kidney Injury↗
PubMed1978

Acne, hypervitaminosis A and hypercalcaemia. A case report.

The ingestion of vitamin A, which is often prescribed for the treatment of acne, may lead to hypervitaminosis A. This syndrome has a wide spectrum of clinical features, hypercalcaemia being of special note since it has been reported in 4 previous cases only. Hypervitaminosis A has been described as resulting from excess ingestion of vitamin A for prevention of sunburn and treatment of minimal brain dysfunction. With the present glut of health foods, this condition should be borne in mind when patients present with symptoms of hypercalcaemia and liver dysfunction.

Acne Vulgaris↗
PubMed1978

Septic abortion with renal failure treated by hysterectomy.

Acute renal failure is a serious and life-threatening complication of septic abortion. The documented mortality rate varies between 30% and 65%. Initial management of the patient with this complication is directed towards resuscitation which should be carried out in an intensive care unit. If significant clinical improvement has not taken place within the first 12--24 hours, then hysterectomy should be considered as an emergency procedure. In 6 of the 7 patients described, it is thought that early hysterectomy was the crucial factor contributing towards their survival. The presence of diffuse intravascular coagulation, which was seen in all our patients, is an added indication for surgical intervention, and its role in the pathogenesis of acute renal failure is discussed.

Abortion, Septic↗
PubMed1978

When to investigate and when to treat hypertension.

When a raised blood pressure is found, a thorough clinical assessment and a few simple investigations are sufficient in the average patient. There are certain clear indications for treatment, but there is a grey zone where suggestions only can be offered. The importance of follow-up examinations, drug side-effects and associated risk factors is stressed.

Adult↗
PubMed1976

Cross-matching assays of cell-mediated immunity for transplant patients.

Assays of cell-mediated immunity before transplantation were performed on 34 patients who were defined as being at high risk by the presence of preformed lymphocytotoxic antibodies and/or HL-A incompatibilities at FOUR locus. Assays for cell-mediated lympholysis type I (cml I) were performed in donor serum, and for CML II in recipient serum, to assess the possible effect of blocking factors in the patients' sera. A positive (greater than 5% specific Cr release) and in particular a greater than 10% Cr release correlated strongly with graft rejection. The correlation between CML II and graft survival was unimpressive. No clinically beneficial blocking factor was demonstrable in the patients's sera in that 5 of 6 patients with a positive CML I but a negative CML II rejected their grafts. Conversely, 6 of 8 patients with a positive CML II and a negative CML I had excellent long-term courses. The use of CML I assay in the selection of grafts for patients at high risk is recommended.

Cadaver↗
PubMed1976

Pregnancy in renal transplant recipients.

Of the 48 female patients attending the outpatient clinic of the Johannesburg General Hospital Transplant Unit between January 1971 and December 1974, 10 became pregnant. Fifteen pregnancies were recorded, 6 of which ended in abortions. Ten infants were born from the remaining 9 pregnancies and 4 (40%) died in the neonatal period. The main cause of neonatal death was prematurity. One major congenital anomaly, a diaphragmatic hernia, was found. Maternal complications were mild and easily controlled, urinary infection being the commonest. One patient showed a moderate reduction in renal function. Obstruction of labour by the transplanted kidney was not encountered, and the two Caesarean sections were performed for obstetrical reasons unrelated to the renal transplant.

Abortion, Therapeutic↗
PubMed1976

Angiography after renal homotransplantation.

The role of angiography in the investigation of problems encountered among 181 patients who received renal transplants at the Johannesburg General Hospital is analysed. In all, 23 patients underwent arteriography or venography after transplantation for the investigation of problems such as renal dysfunction, hypertension and suspected renal vein or iliofemoral venous thrombosis.

Diagnosis, Differential↗