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Biomedical subjects

M A Russell

Publications and source records attributed to M A Russell.

At least 109 records · Page 6Linked to original sources
PubMed1985

Passive exposure to tobacco smoke: saliva cotinine concentrations in a representative population sample of non-smoking schoolchildren.

Saliva cotinine concentrations in 569 non-smoking schoolchildren were strongly related to the smoking habits of their parents. When neither parent smoked the mean concentration was 0.44 ng/ml, rising to 3.38 ng/ml when both parents were cigarette smokers. Mothers' smoking had a stronger influence than did fathers' (p less than 0.01). In addition, there was a small independent effect of number of siblings who smoked (p less than 0.01). The dose of nicotine received from fathers' smoking was estimated as equivalent to the active smoking of 30 cigarettes a year, that from mothers' smoking as equivalent to smoking 50 cigarettes a year, and that from both parents smoking as equivalent to smoking 80 cigarettes a year. This unsolicited burden may be prolonged throughout childhood and poses a definite risk to health.

Adolescent↗
PubMed1985

Differentiation in Acanthamoeba castellanii is induced by specific monoclonal antibodies.

Monoclonal antibodies that bind a large molecular weight plasma membrane protein of Acanthamoeba castellanii cause the cells to differentiate. A different monoclonal antibody that binds specifically to the major plasma membrane protein has no effect upon cell division or differentiation. The induction of differentiation by the monoclonal antibodies requires a bivalent attachment, more than a single binding cycle of the antibody to the plasma membrane protein, does not require cell-cell contact, and appears to be mediated by an inhibition of pinocytosis. These results suggest one of two alternatives: either this free living amoeba possesses a cell surface receptor that serves to initiate the differentiation process when stimulated, or the specific plasma membrane antigen for the differentiation-inducing monoclonal antibodies is an essential component of the pinocytotic mechanism. While it seems more likely on the basis of available evidence that we are observing the biological effects of a cell surface receptor, either of the two alternative circumstances open up investigative areas of large significance.

Amoeba↗
PubMed1985

Pre-abstinence smoke intake and smoking motivation as predictors of severity of cigarette withdrawal symptoms.

Twenty-nine cigarette smokers completed a smoking motivation questionnaire and had expired-air carbon monoxide (CO) and plasma nicotine concentrations measured prior to abstaining from smoking for 24 h. Before and after the abstinence period, the subjects rated mood and physical symptoms known to be affected by cigarette abstinence (e.g. irritability, restlessness). Scores on the "dependent smoking" subscale of the smoking motivation questionnaire correlated significantly with overall withdrawal severity, craving, and increased irritability. "Indulgent smoking" scores correlated positively with increased hunger. Pre-abstinence plasma nicotine concentration significantly predicted craving, hunger, restlessness, inability to concentrate and overall withdrawal severity, while expired-air CO predicted craving and restlessness only. Usual daily cigarette consumption did not significantly predict any withdrawal effects. The data indicate that pre-abstinence measures of smoking motivation and smoke intake may provide a guide to withdrawal severity on smoking cessation and that smokers with a high pre-abstinence nicotine intake experience the greatest discomfort.

Adult↗
PubMed1985

Effects of withdrawal from long-term nicotine gum use.

A small proportion of smokers who stop smoking with the aid of nicotine chewing gum continue to use the gum for more than a year. This study shows that when these people abstain from nicotine gum use they experience withdrawal symptoms similar to those found during cigarette withdrawal, including increased irritability, difficulty in concentrating and a drop in heart rate.

Adult↗
PubMed1985

Theoretical background and clinical use of nicotine chewing gum.

In our view, nicotine chewing gum is the most significant single advance achieved so far in the whole field of smoking cessation. It is the only treatment that has yet been shown to have a specific effect over and above that of attention-placebo factors, and this has been demonstrated repeatedly by several research groups in different countries. It is suitable for use as an adjunct both to intensive psychological methods of treatment and to minimal and largely self-help types of intervention. In either case, it approximately doubles the success rates achieved by intervention without the use of gum. It can be administered effectively by psychologists and family physicians and no doubt by other adequately trained health professionals too. The efficacy of nicotine chewing gum is not limited to the smokers who use it. Its incorporation into a treatment or intervention programme revitalises and maintains the morale of therapists. Until the advent of nicotine gum it has required either a research interest, financial reward, or a degree of masochism to remain for long at the sharp end of the business of helping people to give up smoking. Without a treatment capable of reducing withdrawal symptoms, therapists become drained by having constantly to give out encouragement and support to help their clients to tolerate withdrawal long enough for the difficulties gradually to wane. The rapid and tangible effect of the gum in relieving withdrawal symptoms is a boost to the morale and confidence of client and therapist alike. It is perceived as helpful even by those who fail. This encourages people who relapse to return for further therapy. A discouraging feature with other treatments has been the tendency for those who relapse to avoid contact with their therapists even to the extent of not responding to data collection at long-term follow up. In view of its efficacy, its potential for use in many settings, its minimal demands on therapists' time, and its synergistic effect in encouraging and boosting the confidence of clients and therapists alike, it is possible that over a period of years nicotine chewing gum could have a significant impact on national smoking prevalence. But to achieve this, it is essential that it be used correctly.

Chewing Gum↗
PubMed1984

Does switching to an ultra-low nicotine cigarette induce nicotine withdrawal effects?

Twenty-six smokers took part in a study which examined subjective and physiological effects of switching to an ultra-low yielding cigarette (0.1 mg nicotine) for 10 days. Subjects were randomly assigned to one of two groups. One group continued smoking their usual brand while the other group switched to the low yielding cigarette. Subjective ratings and physiological measures were taken at baseline, then after 1, 3 and 10 days in the respective conditions. Plasma nicotine concentrations dropped by some 60% after switching. Although substantial, this drop was considerably less than the drop in nominal yield of the cigarettes (around 90%), indicating marked compensation on the part of these smokers. Switching to the low yielding cigarette was accompanied by a significant increase in hunger and a drop in heart rate. These effects typically occur following cigarette withdrawal. However, other common cigarette withdrawal symptoms, such as irritability, depression, and inability to concentrate, were not detected.

Adult↗
PubMed1984

Urinary adrenaline concentrations during 10 days of smoking abstinence.

Urinary adrenaline concentrations were measured in 17 subjects during 10 days of cigarette abstinence. Adrenaline concentrations dropped significantly in the first 3 days of cigarette withdrawal. This was followed by a significant rise. More subjects showed a U-shaped function of adrenaline over time than would be expected by chance. The evidence suggests that the drop in urinary adrenaline concentration following cigarette withdrawal does not merely constitute a return to a non-smoking state, but includes an element of rebound resulting from loss of a component of smoking, probably nicotine, to which adaptation has occurred.

Adult↗
PubMed1984

Mouse IgG1 heterogeneity: variable binding of monoclonal IgG1 antibodies to protein A-sepharose.

Binding strength to protein A discriminates three definitive types of mouse monoclonal IgG1. Each of these types of IgG1 elutes from protein A-Sepharose as a coherent peak representing the great majority of IgG1 protein. One type of IgG1 is not present to any significant extent in polyclonal mouse IgG preparations, and to our knowledge has not been reported previously. This type of IgG1 does not bind firmly to protein A at pH 8.0, but is retarded sufficiently that it can be purified by protein A-Sepharose chromatography in high yields.

Animals↗
PubMed1984

Ultrasound attenuation measurements of the liver in vivo using a commercial sector scanner.

Attenuation measurements of various tissue mimicking phantoms and three different groups of patients were obtained using a modified commercial sector scanner. Estimates of attenuation were made using the spectral shift method with mean frequencies at different depths of a region of interest being obtained by both zero crossing and fast Fourier transform techniques. The accuracy and precision of both techniques was compared in phantoms and it was found that the FFT technique yielded less day-to-day variation (SD=3 percent) than the zero crossing technique (5 percent). For larger regions of interest, the range of variation in both techniques was more similar. Day-to-day variation in livers of normal patients was much larger than that seen in phantoms (10 to 15 percent) suggesting that in vivo measurements may be less precise due to actual daily changes in patients' livers. Attenuation estimates of phantoms were high by approximately 0.16 dB/MHz/cm compared to values obtained by transmission techniques. The attenuation values of livers in a group of 31 normal patients ranged from 0.214 dB/cm/MHz to 0.849 dB/cm/MHz with a mean of 0.627 +/- 0.126 dB/cm/MHz for the zero crossing technique while the mean value using the FFT technique was 0.86 +/- 0.168 dB/cm/MHz. A group of 26 Gauchers disease patients also showed wide variation with a mean attenuation value of 0.768 +/- 0.21 dB/cm/MHz using the FFT technique. This was significantly different than that of the normal group (p less than .05). Also, a group of 22 chronic B hepatitis patients was examined, having a mean attenuation value of 0.823 +/- 0.21 dB/cm/MHz, not significantly different from those of normal patients. Highly significant differences were found between the three groups when the power spectrum bandwidths of signals received were compared. These differences may be due to differences in the dependence of attenuation as a function of frequency between the groups and may represent a useful tissue characterization parameter.

Gaucher Disease↗