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Biomedical subjects

N M Johnson

Publications and source records attributed to N M Johnson.

At least 73 records · Page 4Linked to original sources
PubMed1981

Use of computed tomography to demonstrate the extent of tuberculosis.

A group of 15 patients with tuberculosis was investigated by computed tomography to document the extent of the disease at the time of diagnosis. This was compared with information available from the clinical examination. Of the 33 sites of disease shown by CT (confined to the thorax and abdomen), only 17 had been demonstrated by clinical examination and chest x-ray. In addition, 7 patients had cervical lymphadenopathy (an area not scanned). CT shows tuberculosis to be more extensive than would be appreciated by conventional investigation. We think this argues against classifying the disease according to presenting anatomical site.

Humans↗
PubMed1981

Circulating immune complexes in tuberculosis.

Using a polyethylene glycol precipitation method, immune complexes were detected in 56% of patients with active tuberculosis. After antituberculous treatment, 29% remained positive for immune complexes, a frequency similar to that in a group of racially matched clinic controls (35%). In a study of 17 patients whose immune complex levels were determined soon after diagnosis and again when the therapy had ceased, there was a significant decrease in complexed IgM and Clq. Sequential studies of immune complex levels in tuberculosis merit further investigation, their persistence may indicate the continued presence of antigens, and their disappearance from the circulation may be a guide to successful treatment.

Adolescent↗
PubMed1981

T gamma cells in sarcoidosis: E rosetting monocytes suppress lymphocyte transformation.

Increased suppressor T gamma lymphocytes have been described in sarcoidosis. We have shown that a proportion of these cells are esterase-positive, phagocytic, adherent to plastic and stain with an anti-monocyte serum. Removal of these cells or the addition of indomethacin increases the lymphocyte transformation to Con A. Transformation was still reduced in spite of preincubation with plastic and the addition of indomethacin suggesting that a further abnormality exists. Thus, within the increased number of T gamma cells there exists a population of activated monocytes which rosette with sheep red blood cells and could therefore be mistaken for T cells.

Adult↗
PubMed1980

Defective yeast opsonisation of serum in sarcoidosis.

We have studied the opsonising ability of the sera of 49 patients with sarcoidosis. The serum of 11 (22%) patients was defective in this ability, whereas only two (4%) of 46 clinic control subjects and three (7%) of 43 laboratory control subjects showed this defect. The difference between the prevalence of the defect in sarcoidosis and the control groups was statistically significant (p less than 0.01). Although the patients with sarcoidosis who had this defect tended to have pulmonary infiltration, this relationship was not statistically significant. Similarly, there was no correlation between the activity of sarcoidosis and this defect, although there was a significant (p less than 0.05) relationship between the opsonising defect and the persistence of circulating immune complexes. Serum opsonisation is a genetically linked host defense mechanism. Our findings suggest that the presence of this serum defect may render a person more susceptible to sarcoidosis.

Adolescent↗
PubMed1980

Circulating immune complexes in sarcoidosis.

The sera of 50 patients with sarcoidosis were tested for the presence of circulating immune complexes using polyethylene glycol precipitation, followed by single radial immuno diffusion for the amounts of Clg, IgG, IgM, and double diffusion for the presence of IgA. Complexes were detected in 29 (58%) patients. No correlation could be found between the presence of these complexes and the length of history stage, or activity of disease, nor to steroid therapy. Rheumatoid factor was detected in 14 patients (28%), 13 of whom had circulating immune complexes, and 12 of whom had active disease. Total serum C3, CH50, and Clq were normal, as were immunoglobulin levels. In patients with extrathoracic sarcoidosis, especially skin or joint involvement, complexes were commonly found. The aetiological significance of these complexes remains uncertain.

Adolescent↗
PubMed1980

Defective yeast opsonisation of serum in tuberculosis.

We have studied the opsonising ability of the sera of 92 patients with tuberculosis. Fourteen per cent of these patients showed defective opsonising ability compared with 4% in a clinic control group. This increased frequency in TB was accounted for by the greatly increased proportion with defects found in patients with intrathoracic TB (21%). We may have identified a section of the population with a specific genetically linked abnormality of a host defence mechanism which renders them more susceptible to intrathoracic TB. Further population studies are required.

Adolescent↗
PubMed1979

Two unexpected deaths from pneumothorax.

Two patients with primary spontaneous pneumothorax died despite intensive treatment. In the first the pneumothorax had been present for 10 days, and, after insertion of a chest drain, pulmonary oedema developed unilaterally, followed by cardiac arrest. She was resuscitated, but later died of a tension pneumothorax on the other side, probably due to cardiac massage and artificial ventilation. In the second patient, after insertion of a chest drain, mediastinal emphysema spread to the head and neck, causing fatal obstruction of the hypopharynx.

Adult↗
PubMed1978

Pulmonary function in inflammatory bowel disease.

Pulmonary function has been assessed in patients with ulcerative colitis and Crohn's disease and compared with a healthy population. No statistically significant differences were found in the measurements observed within the three groups.

Adult↗