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Biomedical subjects

A Knight

Publications and source records attributed to A Knight.

32 records · Page 2Linked to original sources
PubMed1986

Thyroid-stimulating autoantibodies usually contain only lambda-light chains: evidence for the "forbidden clone" theory.

Burnet's "forbidden clone" theory would predict that in patients with Graves' disease the pathogenic thyroid-stimulating autoantibody (TSab)-secreting clones arise by somatic mutation. Because each lymphocyte and its progeny are permanently committed to producing antibodies of a single light chain type, a clone arising by somatic mutation occurring in a single cell would be expected to produce autoantibodies of exclusively kappa or exclusively lambda type in an individual patient. Using affinity chromatographic techniques and monoclonal antibodies, we investigated the light chain type of TSab in 11 patients with Graves' disease. In all patients tested, TSab activity was confined to a single light chain type, confirming the recent work of Zakarija who used affinity chromatography with polyclonal antisera, but contrasting with earlier studies which used immuno-precipitation methods. Furthermore, the light chain type was lambda in 10 of the 11 patients. These observations provide support for the forbidden clone theory. In addition, the marked preponderance of patients producing TSab of the lambda-light chain type indicates that TSab are more likely to arise from the lambda repertoire of clones than from the kappa repertoire and suggests that immunoglobulin light chain V genes may be genetic determinants for susceptibility to Graves' disease.

Antibodies, Monoclonal↗
PubMed1985

Stress ulceration in the critically ill patient.

Stress ulceration is common in patients receiving intensive care. Its cause is ill defined, life threatening complications are rare but the use of H2 antagonists and antacids in prophylaxis is widespread. The development of haemorrhage and perforation appears to be related to a group of risk factors of which sepsis may be the most important.

Antacids↗
PubMed1985

Astemizole--a new, non-sedating antihistamine for hayfever.

Astemizole, a new histamine H1 receptor blocker, was compared with placebo in an eight week, double-blind trial in the treatment of seasonal allergic rhinitis. Sixty-five patients of either sex were randomized to either astemizole (32 patients: 10 mg t.i.d. on day 1, 10 mg b.i.d. on day 2, 10 mg o.d. for the remainder of the study) or placebo (33 patients). Patients were seen bi-weekly and maintained a daily diary record of symptoms throughout the study. Significantly more patients in the placebo group (12) compared to the astemizole group (2) dropped out of the study due to treatment failure (p less than 0.05). Astemizole significantly reduced the frequency and severity of allergic symptoms. In subjective evaluations of each treatment by both the investigator and the patients, astemizole was judged good to excellent by 68% compared to 30% for placebo (p less than 0.05). One patient in each group experienced drowsiness. The only significant side effect of astemizole was weight gain (20 patients compared to 1 in the placebo group), although only one patient discontinued astemizole for this reason.

Adolescent↗
PubMed1979

Immunological parameters in perennial rhinitis.

As part of a study of the effectiveness of beclomethasone dipropionate in perennial rhinitis five immunologically related parameters were measured. These included skin tests, total IgE, specific IgE, nasal and peripheral blood eosinophil counts. In addition, nasal biopsies were obtained in twenty out of sixty patients. It was apparent that patients with perennial rhinitis formed a heterogeneous group who could be divided into three groups based on the extent of immunological abnormality detected. Group 1 consisted of twenty patients who displayed no abnormality in any of the five parameters studied. Group 2 consisted of twenty-six patients in whom specific IgE was not detected but who had varying degrees of abnormal findings in the other laboratory parameters. The remaining fourteen patients formed a third group in whom specific IgE was detected in addition to abnormalities in other parameters. In general, patients with detectable specific IgE had a higher frequency of abnormal parameters, including abnormal histology of their nasal biopsy, than patients in whom no specific IgE was detected. The heterogeneous nature of perennial rhinitis is discussed. Despite the heterogeneous nature of the total patient group, the majority of patients (80%) treated with beclomethasone dipropionate improved compared to 20% improved in the placebo group. There was no difference in the drug effect between the three groups of patients.

Adolescent↗
PubMed1977

Is there a relationship between lupus erythematosus and lichen planus?

Three patients showing features of both lupus erythematosus and lichen planus are described together with their histological, immunofluorescence and other investigative findings. The similarities between lupus erythematosus and lichen planus are discussed and it is suggested that these may be the result of common pathophysiological pathways.

Adult↗
PubMed1976

Disodium cromoglycate in ragweed-allergic rhinitis.

This study was designed to test the effectiveness of disodium cromoglycate when compared to placebo in a double-blind study in patients with ragweed allergic rhinitis. Patients were selected on the basis of a clinical history and a 4+ reaction to the intradermal injection of water-soluble ragweed, 0.02 c.c. of 500 PNU/c.c. Active agent/placebo groups were selected at random and were on the drug for approximately 8 wk, commencing 1 wk prior to the onset of the ragweed pollen season. Patient response was evaluated using patient diary cards, number of antihistamine tablets taken, and patient interviews. In the Toronto study, of 17 patients on the active drug, 15 were graded as improved, compared to only 6 of 21 placebo-treated patients who were improved. However, in the Hamilton study, results were less impressive. Nonetheless, it appears that intranasal insufflation of disodium cromoglycate was more effective in reducing ragweed hay fever symptoms than placebo.

Clinical Trials as Topic↗
PubMed1976

The relative paucity of IgE in human milk.

The levels of IgE were determined in paired samples of serum and milk when whey obtained 3 to 8 days of postpartum, from 16 human lactating mothers who had reported a history of allergy to a variety of common allergens. Two assay procedures were employed to measure total IgE, a double-antibody assay and a commercially available solid phase assay (RIST). In addition, each sample of serum and whey was tested for specific IgE antibodies to a variety of allergens by the RAST test. The levels of total serum IgE were between 30 and 2300 I.U./ml and relatively good agreement was observed for both the double-antibody and RIST methods. In contrast, total IgE levels in milk whey were either undetectable (less than 3.0 I.U./ml in 14 of 16 subjects) or very low when analyzed by the double-antibody method, but were very high (400 to 1650 I.U./ml when analyzed by the RIST method. However, IgE added to milk whey could be measured by the double-antibody procedure indicating that the low levels detected in milk were not a fault of the double-antibody assay. It was assumed that the RIST test was subject to nonspecific interference by factors in milk whey which caused the determination of high, but incorrect, levels of IgE. Specific IgE antibodies were detected in the serum of 10 of 16 subjects but were not present in milk whey. A comparison of the whey/serum ratios of albumin, IgA, and IgE suggested that little, if any, IgE is selectively synthesized or secreted in the mammary gland.

Animals↗
PubMedDate not supplied

The toxicity and bioaccumulation of selenate, selenite and seleno-L-methionine in the cyanobacterium Anabaena flos-aquae.

A laboratory investigation was conducted to study the toxicity and bioaccumulation of seleno-L-methionine, selenate and selenite in the cyanobacterium Anabaena flos-aquae. The first sub-lethal effects of seleno-L-methionine, selenite and selenate occurred at 0.1, 3.0, and 3.0 mg/L, respectively with a decrease in chlorophyll a concentration (P less than 0.0001). Selenium bioconcentration factors (BCF) were in the order of seleno-L-methionine, selenite, and selenate. Significant decreases in intracellular selenium concentration were observed at both the no effect (NOEL) and low effect levels (LOEL) at each oxidation state tested in the given experiment (p less than 0.0001). Mechanisms for the assimilation, toxicity and regulation of selenium are presented.

Cyanobacteria↗