Control Group Of Non-users Research Articles

Concurrent use of khat and tobacco is associated with verbal learning and delayed recall deficits

The present study assessed whether cigarette smokers who are also regular khat users would demonstrate greater impairments in verbal learning and recall compared to both non-smokers who are khat users and control subjects. An independent-measures, between-subjects design with two covariates. An out-patient, university research center in Taiz, Yemen. Subjects were 175 Yemeni college students (90 men, 85 women) ranging in age from 18 to 38 years. Seventy-five subjects were self-reported chronic cigarette smokers and khat users, 48 non-smoking subjects were self-reported to be chronic khat users and 52 non-smoking subjects reported no current use or history of khat use. Verbal learning and verbal memory recall was assessed by subject performance on the Arabic version of the Rey Auditory Verbal Learning Test (RAVLT). Statistically significant differences (P < 0.05) were observed in RAVLT acquisition learning trials 2-5 and on delayed recall measures between concurrent khat and cigarette users compared to both the khat-only group and the control group of non-users of khat and cigarettes. On each of these trials, concurrent users recalled fewer words, demonstrating a slowed rate of verbal learning. This same pattern of performance was also seen on delayed recall measures. Khat use alone did not affect immediate or delayed recall of previously learned words. Khat users who smoke cigarettes have a lower rate of verbal learning and delayed recall of previously learned verbal material than khat users who do not smoke cigarettes. This may be due to pre-existing differences between these groups of subjects.

Driving on ice: impaired driving skills in current methamphetamine users

Previous research indicates a complex link between methamphetamine (METH) and driving performance. Acute dosing with amphetamines has improved driving-related performance in some laboratory studies, while epidemiological studies suggest an association between METH use, impaired driving, and accident culpability. Current METH users were compared to a control group of nonusers on driving simulator performance. Groups were matched for age, gender, and driving experience. Subjects were assessed for current drug use, drug dependence, and drug levels in saliva/blood as well as personality variables, sleepiness, and driving performance. METH users, most of whom met the criteria for METH dependence, were significantly more likely to speed and to weave from side to side when driving. They also left less distance between their vehicle and oncoming vehicles when making a right-hand turn. This risky driving was not associated with current blood levels of METH or its principal metabolite, amphetamine, which varied widely within the METH group. Other drugs were detected (principally low levels of THC or MDMA) in some METH users, but at levels that were unlikely to impair driving performance. There were higher levels of impulsivity and antisocial personality disorder in the METH-using cohort. These findings confirm indications from epidemiological studies of an association between METH use and impaired driving ability and provide a platform for future research to further explore the factors contributing to increased accident risk in this population.

Implicit and Explicit Cognition of Chinese Heroin Abusers

Sixty-five heroin abusers receiving Methadone Maintenance Treatment (MMT), 38 heroin abusers not receiving MMT, and 30 nonusers of drugs participated in this investigation of cognition in heroin and methadone users. Heroin users were measured for both implicit and explicit cognition, while the control group of nonusers was measured only for implicit cognition. The results demonstrate that implicit cognition can influence the development of addictive behaviors, and that implicit and explicit cognition of heroin were separate and independent constructs. Based on the results of Implicit Association Tests (IAT; Greenwald, McGhee, &amp; Schwartz, 1998) MMT appears to be a valid method for opiate withdrawal treatment as it reverses the implicit desire for heroin in heroin abusers.

Some Mobile Phone Associated Health Problems Among Mobile Phone Workers At Zagazig City, Sharkia Governorate.

Background: Although mobile telecommunications deliver enormous benefit to society, there are concerns whether its electric and magnetic field emissions are linked with cancer or other health hazards. Objectives: 1) determining some of the mobile phone(Mph) associated health problems. 2) identifying some of the risk factors associated with exposure to Mph. Subjects and methods: A comparative cross-sectional study was conducted on 125 workers in mobile phone shops at Zagazig City, Sharkia Governorate and non-exposed control group consisted of 119 Mph users group and 29 Mph nonusers group. All workers were interviewed using a pre-designed questionnaire including sociodemographic data, occupational history, Mph exposure & health complaints experienced during Mph working period and all workers were subjected to blood pressure measurement. Results: The results revealed that, the prevalence of sleep disturbances and tension was significantly higher in Mph workers (48.8% & 60.0%) compared to Mph non-users control group(17.2%, 31.0% and P

MHC-correlated odour preferences in humans and the use of oral contraceptives

Previous studies in animals and humans show that genes in the major histocompatibility complex (MHC) influence individual odours and that females often prefer odour of MHC-dissimilar males, perhaps to increase offspring heterozygosity or reduce inbreeding. Women using oral hormonal contraceptives have been reported to have the opposite preference, raising the possibility that oral contraceptives alter female preference towards MHC similarity, with possible fertility costs. Here we test directly whether contraceptive pill use alters odour preferences using a longitudinal design in which women were tested before and after initiating pill use; a control group of non-users were tested with a comparable interval between test sessions. In contrast to some previous studies, there was no significant difference in ratings between odours of MHC-dissimilar and MHC-similar men among women during the follicular cycle phase. However, single women preferred odours of MHC-similar men, while women in relationships preferred odours of MHC-dissimilar men, a result consistent with studies in other species, suggesting that paired females may seek to improve offspring quality through extra-pair partnerships. Across tests, we found a significant preference shift towards MHC similarity associated with pill use, which was not evident in the control group. If odour plays a role in human mate choice, our results suggest that contraceptive pill use could disrupt disassortative mate preferences.

Nivel auditivo y uso intensivo de teléfonos móviles

IntroductionWide studies and substantial controversies build on utilization of actual mobile phones and appearance of systemic disorders or even tumours, but there is no knowledge about an eventual involvement on early hearing loss. Patients and methodsIn a group of three hundred and twenty-three healthy and normoacoustic volunteers who were usual costumers of mobile phones an audiometric evaluation was made at the beginnig of its use and three years later, inquiring about the periods of time per day and year employed on direct contacts with phone. A healthy and normoacoustic control group of non users was studied too. ResultsCases carried out 24.3±8.2 active contacts, reaching 50.4±27.8 days of mobile phone employment in three years. Audiometric curve was similar in cases andcontrols at the beginning of the study. After this follow-up, cases showed an increase on hearing threshold between 1 and 5 dB HL more than controls in speech tones (p<0.001). Moreover, there was a trend to correlate time of phone use to hearing impairment, but this finding did not result statistically significative. ConclusionsFrequent management of mobile phones in a middle period of time allows to detect a mild hearing loss, but the cause of this disorder keeps unclear.

Characteristics of Ecstasy Users in São Paulo, Brazil

The present study was aimed at identifying patterns of Ecstasy (methylenedioxy-methamphetamine—MDMA) use in the city of São Paulo. Ecstasy users were recruited through the snowball technique. Using the same technique, a non-user control group was recruited among individuals that had never tried the drug but shared with users a similar life style. Users (N = 52) and non-users (N = 52) were interviewed in order to obtain data on socio-demographic characteristics and use of psychoactive drugs. In addition, levels of anxiety, depression and impulsiveness were assessed through Spielberger's IDATE Trace Inventory, Beck's Depression Inventory and Barrat Impulsiveness Scale. Both users and non-users revealed similar socio-demographic characteristics: most subjects were middle class young heterosexual single men and women who had a college degree. Multiple drug use was more frequent among users than among non-users. Other features that were significantly more accentuated among users than among non-users were the presence of tattoos and piercings, the frequency of attending raves and the preference for electronic music. Beck Inventory results pointed to significantly lower depression scores among users. No differences were observed between groups regarding anxiety and impulsiveness scores. Although the use of Ecstasy in São Paulo is restricted to a young middle or high social class, their vanguard lifestyle tends to influence youngsters of other social extractions, so that the use of the drug may soon become widespread and thus a legitimate public health concern.

Estudo da efetividade da intervenção breve para o uso de álcool e outras drogas em adolescentes atendidos num serviço de assistência primária à saúde

The main purpose of this study was to evaluate the effectiveness of a brief intervention and a preventive orientation on the use of alcohol and other drugs directed towards adolescents. Ninety nine youths who sought medical assistance in an out patient service specialized in adolescents were classified, according to their level of consumption of substances, into users during the last month (UM) or non users during the last month (NUM). Each of these was divided into four groups: a control group of users in the last month (COUM), a control group of non users in the last month (CONUM), a Brief Intervention group (BI--in case they were regular users) and a Preventive Orientation group (PO--in case they were non users in the last month). The preventive orientation lasted 2-3 minutes and the brief intervention took about 20 minutes, both followed a structured schedule. All participants were followed-up and evaluated for a 6 months period. In the 6-month follow-up, a significant increase in cannabis, alcohol and tobacco consumption, as well as in the intensity of related-problems, was observed in the CONUM group. The increase of alcohol and tobacco consumption observed in the PO group had a significantly lesser frequency and lower intensity than in the CONUM group. Moreover, no increase in cannabis consumption was observed in this group. The BI group showed a significant reduction in the number of users during the last month with respect to most substances, as well as in relation to substance-related problems. Our results confirm that a single brief intervention session is effective in reducing consumption of psychoactive substances in adolescents. Although influence of other factors could not be discarded, preventive orientation reduced the increase of cannabis consumption but increased use of tobacco and alcohol. Further and more in depth studies are required to evaluate the usefulness of preventive programs on alcohol and other drug consumption, in order to bring to light more effective and comprehensive approaches.

Drugs and human memory (part 2). Clinical, theoretical, and methodologic issues.

Drugs and human memory (part 2). Clinical, theoretical, and methodologic issues.

A statistical model for the evaluation of barrier contraceptive efficacy

This paper describes an approach for the analysis of barrier contraceptive efficacy trials that accounts for timing frequency of intercourse and compliance. We allow exposure variables to vary for each act of intercourse and we control for timing of each act through a specific parametric function of the day of the act relative to the last day of the follicular phase of the cycle. The model can be used to examine the level of protection provided by a barrier versus no contraceptive method even when no control group of non-users is studied, as long as there are acts with no barrier use during the fertile window. We present results of a simulation study which examines performance of estimators and power under a variety of scenarios, including situations where an accurate benchmark for ovulation day is not available. As compared to the survival analysis approach commonly used in this setting, simulation results show that the new approach yields considerable gains in power to detect differences between the efficacy of contraceptive methods. An application to data from the FemCap® versus diaphragm trial show results consistent with previous findings suggesting superiority of the diaphragm but also provides new evidence of the per act protection provided by both methods. Copyright © 2001 John Wiley & Sons, Ltd.

The health impacts of pesticide use on sugarcane farmers in Fiji.

A survey conducted among sugarcane farmers in Fiji found significant differences in the incidence of chronic illness and disease between users of pesticides and a nonuser control group. Though average production of sugarcane was markedly higher among pesticide users, average annual medical expenditures were also significantly higher. Advanced technological methods including chemical pesticides require a system of institutional support to provide, inter alia, information for an effective transition from traditional to modern agricultural practices. Without that support the ad hoc application of technology may result in inefficiency and, in the case of pesticides, increased health risks among the farm population. Besides practical handling and application advice farmers require information describing the chronic health impacts of pesticide exposure to allow their weighing of the full costs of pesticide use against the production benefits.

Why do young women use sunbeds? A comparative psychological study

Many people are keen on getting a skin tan despite being aware of warnings of health hazards. The present study investigates differences between women regularly using sunbeds and a control group of non-users in the areas of self-concept, narcissistic regulatory modalities, social assertiveness and generalized self-efficacy. Thirty women users of suntan salons and 34 women who never used one were investigated with standardized psychological questionnaires. In addition, their knowledge about the hazards of using sunbeds and attitudes to tanning were recorded. Statistical evaluation shows that sunbed users demonstrate more object devaluation: that is, other persons are devalued so that they are not even considered worthy of affection. Furthermore, they also display greater anxiety in their feelings and relationships with others. The results of this pilot study support the hypothesis that a tanned skin, by helping sunbed users to achieve their ideal of beauty, enables them to devalue other people and thus possibly to protect themselves from close relationships. As medical information about the hazards of ultraviolet irradiation fails to make an adequate impression on them, public relations campaigns must be undertaken in order to make them aware of the underlying motives of their behaviour.

The effects of monophasic and triphasic oral contraceptives on ovarian function and endometrial thickness

Objective To analyze and compare the effects of seven low-dose oral contraceptives (OCs) on ovarian function and endometrial thickness.Methods Cross-sectional study of users of one of five monophasic OCs, one of two triphasic OCs and a control group of non-users. Ovarian function, endometrial thickness and serum hormone levels were monitored during days 10–12 and 16–18 of the cycle.Results Serum estradiol was suppressed in OC users to a greater degree during days 16–18 than during days 10–12, whereas serum progesterone during days 16–18 was in the anovulatory range with each preparation. Ovarian activity as measured by follicular size was lowest with desogestrel-containing OCs, whereas greater activity was seen with triphasic levonorgestrel/ ethinylestradiol and triphasic norgestimate/ethinylestradiol. Endometrial thickness in OC users was significantly smaller than in controls.Conclusions All preparations demonstrated profound suppression of ovarian activity and effectively prevented ovulation. Ovarian suppression with desogestrel/ethinylestradiol 150/ 20 did not differ from that of other OCs despite its lower ethinylestradiol content. The use of both triphasic OCs, having a relatively low progestogenic activity, was associated with a higher ovarian activity than that of the monophasic OCs.

Fetal loss associated with two seasonal sources of electromagnetic field exposure.

We have studied two sources of electromagnetic fields where exposure is highly seasonal (ceiling cable electric heat and electrically heated beds). Because many potential confounders could not be addressed, we can make no valid statement about overall differences in abortion rates between those exposed and those not exposed to these seasonal sources. However, by analyzing seasonal trends, we have minimized the problem of unaddressed confounders because we did not look at a difference between the user and nonuser groups, but rather at a difference within the user group during months of higher exposure compared with months of lower exposure. Thus, each user group provides its own control. The function of the nonuser control group is simply to assure that any seasonal trend found in the user group is not just a general seasonal variation in reported fetal loss that can be found equally well in the nonuser population. Using this technique, we found that each user group reported fetal loss disproportionately often during the season when electromagnetic field exposure was increasing.

Serum estrogens and ovulation return in chronic users of a once-a-month injectable contraceptive

To determine whether the long-term exposure to a monthly injectable contraceptive, containing dihydroxyprogesterone acetophenide 150 mg and estradiol enanthate 10 mg, induces significant changes on the serum estrogens profile and ovulation return in women, a study in chronic users was undertaken. Ovarian function was assessed for 3 months following a single injection of the contraceptive agent in a group of women ( n = 7) who have been on this formulation for an average period of 6.7 years and in a nonuser control group ( n = 7). The serum concentrations of 17β-estradiol, estrone and progesterone were measured in samples drawn at regular intervals throughout the entire study. The endometrial bleeding pattern was recorded in all subjects. The results indicated that the post-injection serum estradiol maximum levels (exogenous peak) occurred significantly earlier ( p < 0.05) in chronic users as compared with the non-user control group. Baseline serum estrone concentrations were slightly higher in chronic users than those observed in the control group, while the values of serum 17β-estradiol did not exhibit significant differences among the two groups. Ovulation was documented within 60–91 days after injection in all subjects from both groups. A similar length of the first bleeding-free period was observed in all participants. The overall data provide evidence of a moderate increase of estrone, one of the still active metabolic conversion products of 17β-estradiol, in the sera of chronic users of this combined contraceptive without affecting its pharmacodynamics.

Characteristics of Native American Users of Inhalants

The authors investigated a population of identified users of inhalants at a Native American boarding school and compared and contrasted the users to a control group of nonusers. The subjects included 62 adolescents of Native American descent (mean age of 16.6), classified into one nonuser control group (N = 20) and two user groups: onetime users (N = 21) and repeat users (N = 21). Measures of traditional Native American characteristics, desirable physical and psychological assets, academic achievement, grade point average, adherence to school policy, and self-concept were collected on each subject. A one-way analysis of variance was computed to determine the relationship that existed between the research variables and the membership of each subject in his or her respective groups. Findings are discussed, and similarities of the Native American inhalant users to inhalant users in the general adolescent population are noted.

Psychosocial correlates of chronic cannabis use

The psychosocial effects of chronic heavy use of cannabis were studied in a rural population of males in north India. The user group comprised thirty persons who had been taking only cannabis at least 11 times a month over a period of five years or more. The controls were fifty subjects selected from among the general population to which the users belonged. The controls had not been using any drugs. The subjects had similar age distribution, occupation, socioeconomic status, and educational background. Psychosocial adaptation was assessed by enquiries into such areas as self-aspiration, present occupation, occupational satisfaction, marital status, marital relationships, sexual behaviour, self-reported deviant behaviour, and future planning for children. On no variable were the present users found to be different from the non-user control group.