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Biomedical subjects

H A Lee

Publications and source records attributed to H A Lee.

At least 19 recordsLinked to original sources
PubMed1991

Uraemia: is urea more important than we think?

Urea is accumulated as an osmolyte by some groups of animals even though it impairs protein function. These organisms can withstand high internal urea concentrations because they also accumulate other low-molecular-weight osmolytes, the methylamines, which can offset the effects of urea on proteins. Methylamines have also been found in the medulla of the mammalian kidney (where urea concentrations are high) and in the plasma of human subjects with chronic renal failure. These findings suggest that previous investigations of the potential contribution of urea to the syndrome of uraemia may have been confounded because of the presence of variable concentrations of protective substances. That naturally occurring methylamines or related substances may prove to have a useful therapeutic role in uraemia is also possible.

Animals↗
PubMed1991

Nuclear magnetic resonance studies of blood plasma and urine from subjects with chronic renal failure: identification of trimethylamine-N-oxide.

We have used 1H-, 13C- and 14N-NMR spectroscopy to investigate the constituents of plasma and urine in 16 patients with chronic renal failure (CRF). Resonances not previously observed in spectra of plasma from healthy volunteers were seen in CRF plasma, including those for trimethylamine-N-oxide (TMAO) and dimethylamine (DMA). A possible analogy with the plasma of elasmobranch fishes, in which TMAO stabilizes proteins in the presence of very high urea concentrations, is noted. The intensity of the TMAO resonance for CRF subjects was correlated with the plasma concentration of urea (R = 0.55) and creatinine (R = 0.74), suggesting that the presence of TMAO is closely related to the degree of renal failure. When normal subjects ate a meal of TMAO-containing fish, TMAO appeared rapidly in the plasma and in the urine. Thus TMAO is efficiently cleared by the healthy kidney. Differences in the interaction of lactate with plasma proteins were detected by NMR, suggesting that uraemia impairs their transport roles.

Adult↗
PubMed1991

Sub-optimal doses of human recombinant erythropoietin markedly lower serum ferritin.

Human recombinant erythropoietin in full dose substantially raises the haemoglobin in patients with end stage renal disease on dialysis. In lower doses no or little rise in haemoglobin is achieved but the ferritin, often very high before treatment, is disproportionately lowered. The hormone therefore may be useful in reducing iron overload in other situations.

Anemia↗
PubMed1990

Azathioprine and allopurinol: a potentially dangerous combination.

We report the association of leucopenia and anaemia in five patients given a combination of azathioprine and allopurinol. Three subjects were renal transplant recipients with mild to moderate impairment of graft function. The complication appeared between 4 and 6 weeks following initiation of the combination therapy. Discontinuation of one of the two drugs resulted in full recovery within 4-8 weeks.

Adolescent↗
PubMed1990

Bartter's syndrome and diabetes mellitus.

We here report a case of Bartter's syndrome occurring in association with diabetes mellitus. The patient, an insulin-dependent diabetic, presented with hypokalaemia, inappropriate kaliuresis and metabolic alkalosis. He had high plasma renin activity, relatively low plasma aldosterone, and resistance to infused angiotensin II. A high potassium diet raised total body potassium and serum potassium, did not affect plasma renin activity, but raised plasma aldosterone significantly and did not alter the resistance to angiotensin II. Indomethacin administered acutely reduced urinary potassium and kallikrein excretion and, on chronic administration, lowered plasma renin activity, urinary chloride excretion, and raised serum potassium. Salt restriction resulted in a prompt and significant reduction in urinary sodium and chloride excretion. Urinary kallikrein excretion was very high throughout, increased with sodium restriction, and decreased with sodium loading. Oral potassium supplementation partially corrected the hypokalaemia, but did not affect blood sugar control. In this patient the primary defect appears to have been primary urinary potassium wasting, rather than sodium or chloride wasting. The striking effects of indomethacin suggest that prostaglandins may play a fundamental role in the genesis of the syndrome.

Adult↗
PubMed1990

Enzyme-linked immunosorbent assay for Salmonella typhimurium in food: feasibility of 1-day Salmonella detection.

A microtitration plate, antibody-capture, enzyme-linked immunosorbent assay was developed for detection of Salmonella typhimurium. The assay utilizes a monoclonal detector antibody which shows no cross-reactions with non-Salmonella species and only a slight cross-reaction with one other Salmonella serotype. By using only one cultural stage (in a nonselective, chemically defined medium) prior to the enzyme-linked immunosorbent assay, low numbers of cells in food (10 cells 25 g-1) were detected in 19 h. Non-Salmonella competing organisms did not interfere with detection of S. typhimurium even when present in the ratio of 10(6):1 (non-Salmonella/Salmonella spp.). The assay shows the feasibility of rapid, 1-day testing for Salmonella spp. with antibody technology.

Antibodies, Monoclonal↗
PubMed1989

Life-style changes in a cardiac rehabilitation program: the client perspective.

Major life-style changes are required after an acute coronary event, although the vast majority of patients are unsuccessful in maintaining these changes. This study examines factors clients view as enabling or disabling their life-style changes for health promotion. Ten patients in a cardiac rehabilitation program were interviewed using grounded theory methodology. Both health protection and health promotion stimulated life-style change, as did instructions from the physician and life enjoyment. Enabling and disabling factors affecting the process of repatterning were individually defined, but changes in beliefs, attitudes, and plans facilitated repatterning. Specific precipitants to change, forces influencing change, and methods of repatterning life style are discussed, as are nursing implications.

Adult↗
PubMed1987

Severe hypertension with absent secondary sex characteristics due to partial deficiency of steroid 17 alpha-hydroxylase activity.

A genotypically female patient with 17 alpha-hydroxylase deficiency, and typical symptoms of hypertension, hypokalaemia and lack of secondary sex characteristics, is described. Plasma 17 alpha-hydroxycorticosteroid levels (cortisol, 11-deoxycortisol) and oestradiol were low. Those of 11-deoxycorticosterone, corticosterone, their 18-hydroxy- derivatives, ACTH and gonadotrophins were high and, with the exception of the gonadotrophins, suppressed to normal with dexamethasone which also corrected blood pressure (BP) and electrolyte abnormalities. Plasma aldosterone levels, initially suppressed, increased during treatment but, at 3 months, showed some signs of subnormal responsiveness. Possible reasons for this are discussed. The patient remains well after 9 years on dexamethasone and oestrogen therapy.

Adrenal Cortex Hormones↗
PubMed1987

The use of nursing diagnoses for health promotion in community practice.

The use of nursing diagnosis contributes to health promotion by helping nurses define and organize knowledge for community practice. When community nurses assess clients' responses to life and health events, clinical judgment frequently requires formulation of both positive and problem-oriented nursing diagnoses. Clinical examples and research findings are used to illustrate the use of nursing diagnoses for health promotion in community practice.

Adult↗
PubMed1986

A blind controlled trial of phase-contrast microscopy by two observers for evaluating the source of haematuria.

Two observers, unaware of each other's findings and of the diagnosis, examined red cells in the urine of 109 patients by phase-contrast microscopy. All specimens were examined uncentrifuged by inverted microscopy, and 48 of the 109 were also examined under a light microscope after centrifugation. We were unable to confirm with either method the close correlation between red-cell morphology and diagnosis reported in previous studies, and our 2 observers differed in their interpretation on 38% of occasions. Proteinuria associated with the presence of casts in uncentrifuged urine examined by inverted microscopy was a better indication than red-cell morphology of renal parenchymal disease.

Centrifugation↗
PubMed1985

High-dose methylprednisolone sodium succinate (pulse therapy) in the treatment of renal disease: plasma and urine concentrations.

Methylprednisolone hemisuccinate (MPS) and methylprednisolone (MP) concentrations in plasma and urine were monitored in renal transplant and glomerulonephritis patients who were given i.v. infusions of 0.5 g or 1 g of MPS. A marked individual variation of peak plasma levels of both MPS and MP was observed after the same dose and MPS disappeared from plasma more rapidly than MP. Their clearances from the circulation, however, did not appear to be significantly influenced by the peak plasma levels of the drug, creatinine clearance, administration of previous pulses of MPS or the urinary excretion of unconjugated MPS and MP. Even in patients with profoundly reduced renal function, no accumulation of the drug was apparent when repeated doses of MPS were administered at 48-h intervals.

Adult↗
PubMed1985

The renal unit.

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Chemistry, Clinical↗
PubMed1984

Naftidrofuryl and the nitrogen, carbohydrate, and lipid responses to moderate surgery.

The effect of twice daily infusions of 200 mg naftidrofuryl on the six day cumulative losses of urinary nitrogen after moderate surgery was studied in 32 patients maintained on an intravenous infusion of 4% dextrose and saline. A previous report of the ability of naftidrofuryl to reduce loss of nitrogen was not substantiated, although changes in metabolism in the immediate postoperative period suggested that the drug might exert some advantageous metabolic effect. Further investigations with other nutritional regimens are warranted.

Adult↗