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Biomedical subjects

P Hajek

Publications and source records attributed to P Hajek.

At least 19 recordsLinked to original sources
PubMed1998

A randomized controlled trial of a "buddy" systems to improve success at giving up smoking in general practice.

AIMS: To assess the effect on abstinence rates of pairing up smokers attending a general practice smokers, clinic to provide mutual support between clinic sessions. DESIGN: Randomized controlled trial comparing a "buddy" condition with a "solo condition" in which smokers received the e same treatment but were not paired up. SETTING: A general practice smokers' clinic in London. PARTICIPANTS: One hundred and seventy-two smokers recruited by mailshot. INTERVENTION. Smokers attended a nurse-led smokers clinic 1 week prior to their quit date, on the quite date, 1 week later and 3 weeks after that. Smokers in the buddy condition were paired with another smoker trying to give up at the same time to provide mutual support between clinic sessions. MEASUREMENT: The main outcome measure was the percentage of smokers still abstinent from cigarettes at end of treatment (weeks from quite date), verified by expired air carbon monoxide concentration. FINDINGS: The percentage of smokers still abstinent at the end of treatment was significantly higher in the buddy condition than the solo condition (27% vs. 12%). CONCLUSIONS: A buddy system can provide an effective element of a smoking cessation intervention at minimal cost. Further research is needed to establish the long-term efficacy of this approach and examine the effectiveness of incorporating social support into other types of smoking cessation programmes.

Adult↗
PubMed1997

What happens to anxiety levels on giving up smoking?

OBJECTIVE: DSM-IV lists increased anxiety as a nicotine withdrawal symptom. Increased anxiety has been reported to follow smoking cessation in most but not all studies. Indeed, there is some evidence for a reduction in anxiety, compared with precessation levels, after the first few weeks of abstinence. This study reports data from 101 smokers who attempted to stop smoking and who satisfied DSM-III-R criteria for nicotine dependence. METHOD: Unlike most studies in this area, a strict criterion of lapse-free abstinence was adopted. It is argued that lapses during an attempt at cessation may underlie a transient increase in anxiety. Anxiety was measured both by a single rating typical in withdrawal studies and by the State-Trait Anxiety Inventory--State Form X. Patients were rated 2 weeks and 1 week before cessation, immediately before cessation, 24 hours after cessation, and 1, 2, 3, and 4 weeks after cessation. RESULTS: Seventy patients were abstinent for the 4-week follow-up period. There was no evidence of an increase in anxiety following smoking cessation. However, there was a significant decrease in anxiety from the first week of abstinence. CONCLUSIONS: The results weaken the view that increased anxiety is a robust and central element of the nicotine withdrawal syndrome and suggest that giving up smoking is quite rapidly followed by a reduction in anxiety that may reflect removal of an anxiogenic agent, nicotine.

Adolescent↗
PubMed1996

Randomised controlled trial of ondansetron in smoking cessation.

A double-blind, placebo controlled trial was undertaken to examine the effect of the 5-HT3 antagonist, ondansetron .25 mg bd on cigarette withdrawal symptoms and on proportion of individuals maintaining continuous abstinence for 4 weeks in a smoking treatment programme. A total of 111 smokers were allocated to active or placebo conditions and began taking their study medication 2 weeks before the quit date. They attended the smokers clinic for weekly group treatment sessions. The results showed no evidence for less severe withdrawal symptoms or improved abstinence rates in the active medication group. They suggest that inhibiting 5-HT3 activity is not an effective method of controlling nicotine withdrawal or helping smokers to stop.

Adolescent↗
PubMed1995

Regular smokers, lifetime very light smokers, and reduced smokers: comparison of psychosocial and smoking characteristics in women.

This study compared stable very light smokers (VLS; less than 6 cigarettes a day) with regular smokers (RS; greater than 14 cigarettes a day) in a cohort of women followed up for 1 year. The VLS showed evidence of inhaling the cigarette smoke. They were not novice smokers, nor were they under particular pressure to limit their smoking. Among the 61 VLS, 34 had at one time smoked more than 10 cigarettes per day. These "reduced smokers" were broadly similar to the lifetime VLS, who differed from RS in several important respects. In a multiple logistic regression, education and smoking patterns in relatives were independently associated with very light versus regular smoking. Familial factors and personal resources may protect against dependence among those who use tobacco.

Adult↗
PubMed1994

Characterization of the mitochondrial binding and import properties of purified yeast F1-ATPase beta subunit precursor. Import requires external ATP.

To better understand the early events of the mitochondrial protein import process, we purified the precursor of the F1-ATPase beta subunit (pre-F1 beta) and examined its import into isolated mitochondria. Import of purified urea-denatured pre-F1 beta did not require cytosolic factors. However, the period of productive import was prolonged by the addition of reticulocyte lysate, suggesting that cytosolic factors such as molecular chaperones were acting to extend the period of import competence of pre-F1 beta. Purified pre-F1 beta bound extensively to both cardiolipin-containing liposomes and to intact mitochondria, indicating that a direct interaction between mitochondrial precursors and the mitochondrial outer membrane surface can occur. The ability to chase this surface-bound pre-F1 beta into mitochondria suggests that precursors bound to the mitochondrial surface can be maintained in an import competent conformation. Finally, our defined mitochondrial import system was used to characterize the ATP requirements of pre-F1 beta import in the absence of cytosol. We found a strong requirement for ATP on both sides of the mitochondrial inner membrane, suggesting that one or more previously undetected mitochondrial proteins outside the inner membrane utilize ATP to promote efficient pre-F1 beta import.

Adenosine Triphosphate↗
PubMed1994

Treatments for smokers.

Research in treatments for smokers benefits from the feasibility of relatively large samples and well developed evaluative methodology. The field is currently dominated by nicotine replacement methods, for which some degree of efficacy has been clearly demonstrated. A number of psychological methods are widely used as well, although there is little consistent evidence that one specific method is better than any other. Two approaches to treating smokers can be distinguished, i.e. intensive clinic-based treatments and brief community-orientated interventions, e.g. in primary health care. The latter are applicable on a large scale, and aim to affect overall smoking prevalence. Among intensive treatments, the current state of the art would include nicotine replacement and group support of several weeks' duration. In primary health care, simple routine interventions are the preferred option.

Behavior Therapy↗
PubMed1993

A mitochondrial porin cDNA predicts the existence of multiple human porins.

Pores formed in the outer membrane of mitochondria by mitochondrial porin make it permeable to water-soluble metabolites smaller than approximately 5 kDa. We have isolated a full-length cDNA encoding a human porin. This probe detects a single approximately 1.5-kilobase mRNA species on Northern blots, but multiple hybridizing bands on genomic Southern blots. The open reading frame predicts a 38.1-kDa protein with a pI of 6.59 that is homologous but not identical to a previously reported protein sequence of a 31-kDa porin isolated from human lymphocytes (porin 31HL). The most striking difference between the two porins is that the sequence predicted by the cDNA is longer than the 31HL porin by 27 amino acids at the amino terminus and 38 amino acids at the carboxyl terminus. The porin cDNA directs the in vitro translation of two protein species of approximately 32 and approximately 36 kDa, which appear to result from alternate usage of AUG initiation codons. The 32-kDa protein is the predominant species imported into both rat and yeast mitochondria in vitro. Taken together, these results suggest that multiple porin proteins can be expressed in humans. Additionally, a porin consensus protein sequence has been identified that is conserved in eukaryotic organisms as diverse as yeast and man.

Amino Acid Sequence↗
PubMed1993

Assessment of students.

Explore the source record for details and available documents.

Education, Medical, Undergraduate↗
PubMed1992

Randomised controlled trial of nasal nicotine spray in smoking cessation.

Studies with nicotine chewing gum and nicotine skin patches indicate that nicotine replacement can help people to give up smoking. The rapidity with which nicotine is absorbed when given as a nasal spray suggests that it might be effective for those for whom the other means of replacement are too slow. The efficacy and safety of a nasal nicotine spray as an adjunct to group treatment for stopping smoking were assessed in a randomised, double-blind, placebo-controlled trial in which 227 cigarette smokers attending the Maudsley Hospital Smokers Clinic received 4 weeks of supportive group treatment plus active nicotine (0.5 mg per shot) or placebo nasal spray. The main end-point was biochemically validated complete abstinence from smoking from the third week of group treatment until the 12-month follow-up. Side-effects were assessed by self-reports and, where necessary, by physical examination. Of subjects assigned to active treatment 26% (n = 30) were validated abstinent throughout the year, compared with 10% (n = 11) of those assigned to placebo (relative abstinence rate 2.6, 95% CI 1.5-4.5, p less than 0.001). The advantage of the active spray was greatest in the heaviest smokers. Plasma nicotine concentrations from the spray were typically between one-half and three-quarters of baseline smoking levels. Tobacco-withdrawal symptoms, craving for cigarettes, and weight gain in abstinent subjects were reduced by the active spray. Minor irritant side-effects were frequent in both active and placebo sprays, but only 2 subjects had the spray discontinued as a result. No serious adverse effects were encountered. Nasal nicotine spray combined with supportive group treatment is an effective aid to smoking cessation.

Administration, Intranasal↗
PubMed1991

Effect of buspirone on cigarette withdrawal symptoms and short-term abstinence rates in a smokers clinic.

This paper reports on a double blind trial of the effect of buspirone, 15 mg per day, on cigarette withdrawal symptoms and ability of smokers to maintain abstinence during treatment. A total of 61 smokers were randomly assigned to active or placebo conditions. They were maintained on their drug for 2 weeks prior to attempting abstinence and then for a further 4 weeks of abstinence. Subjects attended weekly group sessions of a psychological treatment programme. There was no evidence that the side effects in the active drug group were worse than those in the placebo group. Although there was no significant difference between active and placebo conditions on withdrawal symptoms, smokers in the active drug condition were more than twice as likely to maintain abstinence for the duration of the study than those in the placebo condition (47% versus 16%, chi square = 5.3, P less than 0.025). The results provide preliminary evidence for short-term efficacy of buspirone as an aid to smoking cessation at a low dose. They also provide evidence of a dissociation between withdrawal symptoms and successful abstinence.

Adult↗
PubMed1991

Magnetic resonance in lesions of the parotid gland.

In a prospective study the relevance of magnetic resonance (MR) for the diagnoses of tumors of the parotid gland has been evaluated. Due to the excellent soft tissue contrast and also the possibility of imaging in various planes and sections and to the high resolution achieved by surface coils, it was possible to visualize the lesions and the surrounding anatomy in great detail. MR combines the advantages of ultrasound and computed tomography and is indicated if a tumor cannot be defined sharply by using ultrasound or CT.

Adipose Tissue↗
PubMed1991

Dream of absent-minded transgression: an empirical study of a cognitive withdrawal symptom.

Among 293 smokers abstinent for between 1 and 4 weeks, 33% reported having at least 1 dream about smoking. In most dreams, subjects caught themselves smoking and felt strong negative emotions, such as panic and guilt. Dreams about smoking were the result of tobacco withdrawal, as 97% of subjects did not have them while smoking, and their occurrence was significantly related to the duration of abstinence. They were rated as more vivid than the usual dreams and were as common as most major tobacco withdrawal symptoms. In subjects abstinent for 1 year, 63% recalled having dreams about smoking. They had on average 5 of them, and about a quarter occurred after the 6th month of abstinence. Having dreams about smoking was prospectively positively related to maintenance of abstinence. An explanation of this finding based on the association of smoking in dreams with aversive emotions is offered.

Adult↗
PubMed1991

Individual differences in difficulty quitting smoking.

This essay comments on the main approaches to studying individual differences in ability to quit smoking, and suggests complementing them with a concept of 'difficulty of quitting'. Several areas of research into determinants of ability to quit smoking are discussed, including measures of dependence, reactivity to nicotine, severity of withdrawal symptoms, endurance of discomfort, and psychological well being. A number of correlates of inability to quit may have a common denominator in stress and neuroticism. If these are the primary obstacles to quitting, changes in the composition of the smoking population and in the image of smoking can be expected which could lead to smoking losing some of its appeal for potential new recruits.

Adaptation, Psychological↗
PubMed1990

Effect of glucose tablets on craving for cigarettes.

Clients attending a smokers clinic were randomly allocated to two groups to assess the effects of glucose tablets in reducing craving for cigarettes. Smokers who had already been abstinent for 1 week were eligible to take part in the study. All subjects completed rating relating to urge to smoke and craving. Then subjects in one group were given packets of dextrose tablets and those in the other group were given packets of tablets containing sorbitol (a low calorie sweetener). Ratings of urges to smoke and craving were taken after 1 week, during which time the subjects had been asked to chew their tablets ad lib. Eight out of ten smokers in each group maintained abstinence. The remaining two smokers either did not abstain or did not turn up for the second measurement session. There was a significant reduction in ratings of urges to smoke and craving in the glucose group compared with the sorbitol group. These results support a theory postulating a link between glucoregulation and cigarette craving. If the results are replicated and it is shown that the reduction in craving translates into improved abstinence rates, oral glucose could be of assistance to smokers wishing to give up.

Female↗
PubMed1990

What do opiate addicts and cigarette smokers mean by "craving"? A pilot study.

There is general agreement that the term 'craving' requires clarification. This present report presents a pilot study in which groups of opiate addicts and cigarette smokers completed a brief rating scale to describe the frequency and intensity with which they had certain feelings while craving for their own drug of dependence. Craving was reported as being a dysphoric state and opiate addicts described more frequent and more intense dysphoric feeling while craving. Despite the difference in mean scores there were some similarities in the overall profile of scores in the two groups. Implications of these findings are discussed.

Adult↗