Search PubMed⌕ Search

Biomedical subjects

M L Snaith

Publications and source records attributed to M L Snaith.

At least 73 records · Page 4Linked to original sources

Variation in circulating immune complex levels with diet, exercise, and sleep: a comparison between normal controls and patients with systemic lupus erythematosus.

Circulating immune complexes (CIC) were measured in 4 normal controls and 8 patients with systemic lupus erythematosus (SLE) by a polyethylene glycol precipitation (PEG) method during a 24-hour period. In all the normal controls levels fell during sleep and after drinking 1 pint (568 ml) of milk and rose before getting out of bed and after moderate exercise. There were also marked differences in the patterns of rise and fall of the CIC levels between the normal controls and patients with SLE. Insufficient account has been taken of these physiological influences in CIC levels in previous studies attempting to relate disease activity to quantitative levels.

Adult↗

Lymphocyte antigens in systemic lupus erythematosus: studies with heterologous antisera.

Rabbit antisera were produced against pooled living lymphocytes from 25 patients with active systemic lupus erythematosus (SLE). Lymphocytes collected at plasmapheresis or venipuncture were frozen in liquid nitrogen and later coated with rabbit antibody to normal human tonsils and normal thymocytes immediately before intravenous immunization of rabbits. Antisera were subsequently extensively absorbed with normal human tonsillar cells, thymocytes, peripheral blood lymphocytes, erythrocytes, and leukocytes from patients with myelogeneous and lymphatic leukemia until residual base-line immunofluorescent staining of normal human lymphocytes using F(ab)2' of whole antisera averaged less than 5%. Absorbed pepsin-digested antisera detected membrane antigens which were markedly increased (mean 32%) on lymphocytes from patients with active SLE (P less than 0.05). Membrane antigens reacting with absorbed, pepsin-digested antisera were present on both T and B cells but, in most instances, predominated on T cells. Control observations using absorbed pepsin-digested antisera to normal human lymphocytes or peripheral blood lymphocytes from patients with rheumatoid arthritis showed no similar specificity. SLE patients treated with moderate or high dose corticosteroids or immunosuppressive agents (cytoxan or azathioprine) appeared to lose lymphocyte antigens detected by these reagents. Control studies with other connective tissue disease patients, miscellaneous hospitalized subjects, or normal controls showed low levels of reactivity (2-5%). SLE lymphocyte membrane antigens uniquely increased during active disease; this may represent neoantigens or alterations associated with the disease itself.

Adult↗

Metal sensitivity in patients with a hinge arthroplasty of the knee.

Fifty patients who had received a hinge arthroplasty of the knee were investigated for possible metal sensitivity. Patients were patch tested against all the metal constituents of the prosthesis. Positive patch tests were found in 32% of patients. Seventeen patients had either lossening or a persistent sterile discharge from the knee. No correlation was found between these complications and metal sensitivity. It was concluded that metal sensitivity is probably not a primary factor in the pathogenesis of complications, particularly loosening.

Adult↗

Antiribonucleoprotein antibodies in connective tissue diseases: estimation by counterimmunoelectrophoresis.

One hundred and seventy-two patients with various connective tissue diseases were investigated for the presence of serum antibodies to extractable nuclear antigen (ENA) and its major components, ribonucleo-protein (RNP) and Sm antigen. The counter-immunoelectrophoresis assay allowed independent detection and measurement of antibodies to the different components. All 13 patients with mixed connective tissue disease (MCTD) had anti-RNP antibody in high titres, 16% of patients with systemic lupus erythematosus (SLE) had low titres, and none of the patients with scleroderma had anti-RNP antibody. MCTD seems to be more benign than either SLE or scleroderma. The counterimmunoelectrophoresis assay is a simple and sensitive technique for confirming the diagnosis.

Antibodies↗

Salmonella typhimurium arthritis in rheumatoid disease.

Septic arthritis is a well recognized complication of rheumatoid arthritis (British Medical Journal, 1976; Mitchell et al., 1976), particularly after joint replacement (Freeman, 1976). We report here infection with an unusual organism--Salmonella typhimurium.

Aged↗

Clinical and biochemical observations on three cases of hypoxanthine-guanine phosphoribosyltransferase deficiency.

Clinical and enzymatic studies on two brothers with severe deficiencies of erythrocyte hypoxanthineguanine phosphoribosyltransferase (HGPRTase) are described, and are compared with similar studies of a classical case of the Lesch-Nyhan syndrome from another family. The two brothers have no neurological abnormalities, only traces of erythrocyte HGPRTase, erythrocyte adenine phosphoribosyltransferase activities approaching the high levels found in the Lesch-Nyhan patient, and similarly raised plasma and urinary concentrations of uric acid. Despite these strong biochemical similarities between the three patients, there were wide differences in the clinical case histories. In both families the enzyme deficiency appeared to be inherited as an X-linked character through asymptomatic carrier females. The relationship of HGPRTase deficiencies to the Lesch-Nyhan syndrome is discussed. Some observations relating to techniques are reported. Cellulose acetate has been found to give much better separations of labelled reaction products in low-level phosphoribosyltransferase assays than filter paper, when used as a supporting medium for electrophoresis. The analysis of hair follicles gives indications of individuals heterozygous for the enzyme deficiency, but the proportion of enzyme-deficient follicles was very small, and the test needs support from studies of other cell types. Using haemolysates, there were signs of a slow indirect conversion of hypoxanthine to inosinic acid, via inosine. Inosine appears to be labelled by a ribosyl-transfer reaction.

Adenine Phosphoribosyltransferase↗

Treatment of patients with systemic lupus erythematosus including nephritis with chlorambucil.

Six female patients with systemic lupus erythematosus (S.L.E.) have been treated with chlorambucil. In five the decision was taken after failure by corticosteroids to control progressive renal disease in the face of unacceptable corticosteroid toxicity. After the introduction of chlorambucil renal function improved and all patients remain well six, six, five, three, and two-and-a-half years later, respectively. On renal biopsy five had focal proliferative glomerulonephritis. Repeat biopsy in two cases showed quantitative improvement. The sixth patient was treated with chlorambucil because of failure by corticosteroids to control peripheral vascular lesions and haemolysis and she remains well four years later. In four patients is it probable that amenorrhoea was related to chlorambucil treatment, but there were no other important side effects although one patient developed a degree of marrow depression during treatment. Chlorambucil may hold advantages over the immunosuppressive drugs normally recommended in this condition, azathioprine and cyclophosphamide, as it appears less liable to cause important marrow suppression and, unlike cyclophosphamide is not associated with alopecia and haemorrhagic cystitis.

Adult↗

Effect of oestrogen therapy on plasma and urinary levels of uric acid.

Uric acid clearance studies were carried out on a low-purine diet in 22 trans-sexual men before and during oestrogen therapy for this condition (stilboestrol in 21 cases, ethinyloestradiol in one). Plasma uric acid fell in 15 of the subjects and urinary uric acid rose in 17 of 20 subjects in whom satisfactory collections were obtained. These changes are significant and it is suggested that hormonal influences are responsible for the known age and sex differences in plasma uric acid.

Adult↗