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Biomedical subjects

M W McNicol

Publications and source records attributed to M W McNicol.

At least 19 recordsLinked to original sources
PubMed1993

The effect of nicotine and carbon monoxide on exercise performance in normal subjects.

In a partially blind randomized control study, nine healthy adult men performed progressive sub-maximal exercise tests, either after chewing nicotine chewing gum (4 mg) or breathing carbon monoxide (320 p.p.m.). Neither agent significantly affected exercise performance, despite a mean rise in blood nicotine to 17.0 ng ml-1 during nicotine administration and a COHb rise to 6.9% whilst breathing carbon monoxide. There was a significant rise in heart rate and blood pressure (P < 0.01) after nicotine administration. The reasons for absence of significant effect on cardiovascular or respiratory performance are discussed.

Adult↗
PubMed1986

Distribution of carboxyhaemoglobin concentrations in smokers and non-smokers.

Carboxyhaemoglobin concentrations were measured in 3487 subjects comprising 1255 non-smokers, 1933 cigarette smokers, 193 cigar smokers (39 primary, 154 secondary), and 106 pipe smokers (30 primary, 76 secondary). In cigarette smokers the mean carboxyhaemoglobin concentration was 4.78% of the total haemoglobin and 94.7% of smokers had a concentration greater than 1.7%. Primary cigar smokers had a much lower mean carboxyhaemoglobin concentration (0.93%), and only 10.3% had concentrations greater than 1.7%. Primary pipe smokers also had a low mean carboxyhaemoglobin concentration (1.36%) and none had a concentration above 1.7%. Secondary cigar smokers had a high mean concentration (6.80%) and 97.4% had values above 1.7%; the findings in secondary pipe smokers were similar--the mean concentration was 3.39%, 94.7% having values greater than 1.7%. The lower carboxyhaemoglobin concentrations in primary pipe and cigar smokers suggest that in general they do not inhale, and the raised concentrations in cigarette smokers who change to pipes or cigars suggest that they usually continue to inhale and to absorb large amounts of carbon monoxide and other constituents of tobacco smoke.

Carboxyhemoglobin↗
PubMed1985

Sarcoidosis in a racially mixed community.

Over a 23-year period 497 patients with sarcoidosis were seen at Willesden Chest Clinic, of whom 151 were British, 105 Irish, 165 West Indian, and 35 Asian. The estimated annual incidence was: British 4/100,000, Irish 21/100,000, West Indian 58/100,000 and Asian 14/100,000. There was a marked female preponderance in the Irish (65 per cent) and West Indians (57 per cent). The female mean age was 35 years, the male mean age 32 years. Asian and West Indian patients were older (mean 37 and 38 years) and Irish patients younger (mean 29 years). West Indian patients more frequently had involvement of the less common extrathoracic sites. In 402 patients the outcome was known: 64 per cent of patients recovered within five years but proportionally fewer West Indians (55 per cent) and Asians (48 per cent) recovered. The greater morbidity in the West Indian and Asian patients was particularly associated with extrathoracic disease in which the results were poor.

Adolescent↗
PubMed1984

Anergy in sarcoidosis: the role of interleukin-1 and prostaglandins in the depressed in vitro lymphocyte response.

We have shown that peripheral blood monocytes from patients with sarcoidosis release reduced amounts of interleukin-1 (IL-1) when compared with normals. In part, this defect explains the relative in vitro unresponsiveness of T lymphocytes from patients with sarcoidosis as measured by mitogen- or antigen-induced lymphocyte transformation. The addition of supernatants containing pre-formed IL-1 partially restored this defect. This enhancement was found to be additive to the previously described effect of indomethacin, an inhibitor of prostaglandin synthesis. Thus, it would appear that the activated peripheral blood monocytes found in sarcoidosis not only cause reduced lymphocyte proliferation by acting as suppressor cells but are also unable to act as accessory cells in producing IL-1.

Adult↗
PubMed1984

Pneumococcal pneumonia with bacteraemia.

Fourteen cases of pneumococcal pneumonia with bacteraemia have been studied. Thirteen of the patients were older than 50 years and in ten there was evidence of pre-existing disease. Pneumococci of six serotypes were responsible for these infections but type 3 was the commonest and was associated with three of the four fatal cases. The patients who died all had evidence of renal failure. Eight of the ten survivors had prerenal failure which responded to treatment. Hyponatraemia was a common finding. Despite prompt antibiotic treatment and intensive therapy there is still a high morbidity and mortality from this condition.

Adult↗
PubMed1982

Blunted sympathoadrenal response to exercise in asthmatic subjects.

Six asthmatic subjects and six matched controls performed a standardized exercise test in which resting and post-exercise blood samples were assayed radioenzymatically for catecholamines. Plasma adrenaline one minute after exercise rose over threefold in the controls whereas in the asthmatic subjects there was no increase. Plasma noradrenaline increased to five times the basal concentration in the controls, but to less than half this level in the asthmatic subjects. These results agree with a recent study (Barnes et al. 1981) and suggest there is a marked abnormality of the sympathoadrenal response to exercise in asthmatic subjects.

Adult↗
PubMed1981

Survey of antibiotic prescribing in a district general hospital. III. Urinary tract infection.

A 28 day survey of all antibiotic prescriptions in a district general hospital included a brief interview with the prescriber of each prescription. Fifty-nine antibiotic courses were stated by the prescriber to be for the treatment of urinary tract infection (UTI). Urine specimens from all patients treated for UTI were sent to the laboratory for bacteriological examination. 29 patients' treatment was started as the result of isolation of bacteria from the urine. 20 of the patients also had symptoms suggestive of UTI. 4 patients were treated solely because bacteria had been isolated from "routine" catheter stream urine specimens. 7 patients were treated for UTI despite the availability, at the time of prescription, of a laboratory report stating that bacteria had not been isolated from the urine. 19 patients' treatment was started before the results of bacteriological tests were available. By combining information about bacteriological examination of the urine specimens and clinical details recorded during the interview with the prescribed, it was considered that both initiation and continuation of antibiotic treatment was justified for 28/55 patients and that either initiation or continuation of treatment was unjustified for 27/55 patients.

Anti-Bacterial Agents↗
PubMed1981

Survey of antibiotic prescribing in a district general hospital. II. Lower respiratory tract infection.

A 28 day survey of all antibiotic prescriptions in a district general hospital included a brief interview with the prescriber of each prescription. One hundred and nineteen antibiotic courses were stated, by the prescriber, to be for the treatment of lower respiratory tract infection. By combining the prescriber's clinical evidence, laboratory data, and radiographic findings, an "index of infection" was produced for 94 patients. This index reflected features associated with bacterial infection of the lower respiratory tract and suggested that 49% of the antibiotic courses prescribed were justifiable, 11% were questionable, and 40% were unjustifiable. The choice of antibiotic was usually appropriate to the prescriber's diagnosis. Over 80% of the antibiotics used were of the penicillin group. Ampicillin, the single most frequently prescribed drug, accounted for 60% of the prescriptions. The frequency of diagnosis of chest infection increased with age. Almost 40% of patients over 81 years old who were admitted to hospital during the survey were prescribed antibiotics for chest infection. A higher proportion of older than of younger patients had low indices of infection.

Adolescent↗
PubMed1981

Survey of antibiotic prescribing in a district general hospital. I. Pattern of use.

In a survey of all antibiotic prescription in a district general hospital during November, 1978, the reason for each prescription was determined by a brief interview with the prescriber. 28% of all inpatients received antibiotics. Older patients were prescribed antibiotics more often than were younger patients. Ampicillin was the most frequently used antibiotic, accounting for over 40% of prescriptions. Over 70% of antibiotic courses were stated by the prescriber as being for the treatment of infection and the remainder were said to be prophylactic. Although 80% of the antibiotics were assessed as suitable treatment for the stated infection, most of the patients were treated without bacteriological evidence of the infecting agent and, for these patients, prescribers were unable to specify the pathogen against which treatment was intended in 50% of the courses they initiated. Only 7% of antibiotics prescribed for conventional surgical prophylaxis fulfilled all the criteria used to assess the suitability of choice of drug and the method and timing of its administration.

Adolescent↗
PubMed1981

The inhaling habits of pipe smokers.

Carboxyhaemoglobin and plasma nicotine levels were compared in five primary and five secondary pipe (i.e. previous cigarette smoking) smokers over the course of one hour's pipe smoking. The primary pipe smokers had low pre-smoking nicotine and carboxyhaemoglobin levels with a small increase after smoking (carboxyhaemoglobin 1.1% rising to 1.26% and nicotine 7.7 nmol/litre rising to 33.9 nmol/litre). Secondary pipe smokers had a higher pre-smoking carboxyhaemoglobin and nicotine level with a significant rise during smoking (carboxyhaemoglobin 3.0% rising to 4.3%, plasma nicotine 74.3 nmol/litre rising to 215.8 nmol/litre), indicating significant inhalation and absorption of carbon monoxide and nicotine. These results indicate that primary pipe smokers, who have never smoked cigarettes, do not inhale and absorb very little nicotine. Secondary pipe smokers do not lose their habit of inhaling and absorb large amounts of nicotine and carbon monoxide. They may not share the lower health hazard of the primary pipe smoker.

Adult↗
PubMed1981

The effect of anosmia on smoking habits.

Sixteen cigarette smokers who had developed complete anosmia were questioned about their smoking habits. Four subjects increased their cigarette consumption, 8 were unchanged and 4 decreased. The development of anosmia has no consistent effect on cigarette smoking.

Adult↗
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↗