[Seroprevalence and Risk Factors of Hepatitis B, C and D in Adults in Trabzon, Türkiye]. / Trabzon'da 20 Yas Üstü Eriskinlerde Hepatit B, Hepatit C ve Hepatit D Seroprevalansi ve Risk Faktörleri.

Viral hepatitis are infections that can cause liver damage, become chronic, lead to cirrhosis, hepatocellular carcinoma and ultimately result in death due to their ability to spread in the community through blood and infected body fluids. The aim of this study was to determine the seroprevalence of hepatitis B (HBV), hepatitis C (HCV), and hepatitis D (HDV) transmitted through blood among individuals living in Trabzon province and to examine the factors potentially associated with seroprevalence. This cross-sectional study was conducted in Trabzon province, located in the northeast of Türkiye, including a total of 10 districts, including the central district. Since seroprevalence was calculated for HBV, HCV, and HDV in the study, the sample size was separately calculated for each, and the calculated maximum sample size of 1116 was accepted as the minimum sample size for the study. The study was completed with 1502 participants. Serological tests for HBV included HBsAg, anti-HBs, and anti-HBc IgG; for HCV, anti-HCV; and for HDV, anti-HDV were analysed. Data were evaluated for HBV risk factors using univariate analyses with Chi-square test and for multiple analyses using enter model logistic regression analysis. The mean age of the participants was 45.7 ± 16.6 years, with 767 (51.1%) being female. The prevalence of HBV seropositivity, indicating vaccination, was 23.0%, while the seroprevalence of HBV among unvaccinated adults was 27.4%. HBsAg positivity was 5.1%, and isolated anti-HBc IgG positivity was 4.2%. The proportion of individuals with HBsAg in the gray zone was 0.5%, while the positivity rates for anti-HBs and anti-HBc IgG (indicating past infection) were 17.6%. The prevalence of anti-HCV was six per thousand, while anti-HDV was not detected in the analyses. HBsAg positivity and co-infection with HCV were found in one person, and among the nine individuals positive for anti-HCV, isolated anti-HBc IgG positivity was detected in three. Increasing age, presence of a person with jaundice in the family, presence of diabetes mellitus, alcohol use and cupping therapy were identified as risk factors for HBV in the logistic regression analysis. Risk factors for HCV in univariate analyses were being over 40 years old, presence of hepatic steatosis and receiving dialysis treatment. The results of the study indicate that despite being included in our vaccination schedule and the administration of vaccines to high-risk adults, HBV still requires intensive attention as a public health problem. HCV, lacking a vaccine has been evaluated as an infectious agent that needs to be taken into consideration due to its potential risks and requires the complete implementation of individual and social precautions.

An evaluation of traumatic deaths associated with animal attacks: A 10-year autopsy study.

BACKGROUND: Just as throughout the world in general, deaths related to animal attacks continue to be a public health problem in Turkey. A decrease in areas of natural habitat because of human invasion, and the use of these areas for hunting, wood-cutting, recreational and sporting activities has increased the possibility of humans encountering wild animals. METHODS: A physical retrospective screening was made of the forensic records of a total of 8944 autopsy cases in the Forensic Medicine Institute of the Trabzon Group Directorate in the 10-year period between Januarry 2007 and December 2016. RESULTS: When the types of animals causing the traumatic death were examined, the most frequent was cattle in 15 cases followed by horses in 7 cases, bears in 4 cases, wolves in 2 cases, and wild boars in 2 cases. According to the autopsy results, the cause of death was most often intrathoracic bleeding and intrathoracic organ damage, the regions of the body injured were seen to be most often the chest and back, and the most common form of injury was blunt/crush trauma. CONCLUSION: From these records, cases were identified where the cause of death was traumatic animal attack, and examination was made of the sociodemographic characteristics, the type of animal that caused the injuries, information about the location of the incident, witness statements, information about the healthcare centre, findings of external examination and autopsy, and the cause.

Deaths due to 'patpat' accidents in the Black Sea Region, Turkey.

BACKGROUND: Overtime, agricultural machines have been designed appropriate to more simple needs, instead of tractors which have a wide area of use. An example of these is the 'patpat,' so named because of the sound of the motor, and for which the main purpose is ploughing. METHODS: A patpat is a single-axle, two-wheeled tractor with a trailer attached. In this descriptive study, the descriptive characteristics and causes of death were analyzed of case related to patpat accidents for which autopsies were performed by the Forensic Medicine Institution Trabzon Group Directorate between 2006 and 2017. RESULTS: Information was retrieved from the scene of accident examination documents, and the autopsy and laboratory records. The 21 cases comprised 17 (81%) males and 4 (19%) females, with a mean age of 47.6±20.3 years (median: 57, range: 10-75 years). Of the total accidents, in 85.7% (n=18), no other vehicle was involved. Following the accident, 52.4% (n=11) of the patpats were found at the side of the road, and 33.3% (n=7) at the edge of a stream or at the bottom of a steep valley. The cause of the accident was determined to be that the patpat had overturned on a bend in 33.3% (n=7) cases and in 85.7% (n=18) of cases, the patpat was found overturned or on its side. The most common injury was being thrown from the vehicle (38.1%, n=8), and in 66.7% (n=14) of cases, the deceased was the patpat driver. CONCLUSION: Patpat accidents are a serious problem because of the frequency of use of these vehicles without proper supervision and especially because of the hazardous topographical conditions where they are used.

Partial remission in children and adolescents with type 1 diabetes: an analysis based on the insulin dose-adjusted hemoglobin A1c.

OBJECTIVES: Most patients with type 1 diabetes (T1D) experience a transient phase of partial remission (PR). This study aimed to identify the demographic and clinical factors associated with PR. METHODS: This was a longitudinal retrospective cohort study of 133 children and adolescents with T1D. PR was defined by the gold standard insulin dose-adjusted hemoglobin A1c (HbA1c) (IDAA1c) of ≤9. RESULTS: Remission was observed in 77 (57.9%) patients. At diagnosis, remitters had significantly higher pH (7.3 ± 0.12 vs. 7.23 ± 0.15, p=0.003), higher C-peptide levels (0.45 ± 0.31 ng/mL vs. 0.3 ± 0.22, p=0.003), and they were significantly older (9.3 ± 3.6 years vs. 7.3 ± 4.2, p=0.008) compared with non-remitters. PR developed more frequently in patients without diabetic ketoacidosis (DKA) (p=0.026) and with disease onset after age 5 (p=0.001). Patients using multiple daily insulin regimen were more likely to experience PR than those treated with a twice daily regimen (63.9 vs. 32%, p=0.004). Only age at onset was an independent predictor of PR (OR: 1.12, 95% CI: 1-1.25; p=0.044). Remitters had lower HbA1c levels and daily insulin requirement from diagnosis until one year after diagnosis (p<0.001). PR recurred in 7 (9%) patients. The daily insulin requirement at three months was lower in remitters with PR recurrence compared to those without (0.23 ± 0.14 vs. 0.4 ± 0.17 U/kg/day, p=0.014). CONCLUSIONS: Addressing factors associated with the occurrence of PR could provide a better comprehension of metabolic control in T1D. The lack of DKA and higher C-peptide levels may influence PR, but the main factor associated with PR presence was older age at onset. PR may recur in a small proportion of patients.

Clinical, sonographical, and pathological findings of pediatric thyroid nodules.

Thyroid nodules are less frequent in children than in adults. A higher rate of malignancy is highlighted in this group. We aimed to analyze the clinical, laboratory, and ultrasound (US) findings of children and adolescents with benign and malignant thyroid nodules. This was a retrospective review of children and adolescents evaluated at a tertiary pediatric institution between 2007 and 2019. Patients with autonomously functioning nodules, autoimmune thyroid diseases, and a history of oncohematological disorders were excluded. A total of 102 patients with 131 nodules were identified. The study population included 57 females (55.9%); the average age was 10.6 ±4 years. Thirty-five nodules (26.7%) ranging 4.5-36 mm had a fine-needle aspiration (FNA) done: 45.7% (n = 16) were benign, 11.4% (n = 4) were classified as atypia, and 8.5% (n = 3) were consistent with papillary carcinoma. Fourteen patients (13.7%) underwent surgery. Five (4.9%) were finally diagnosed with papillary thyroid cancer. Of the 6 patients with benign FNAs, all except one, which was initially reported as atypia by an earlier FNA but was later diagnosed with papillary carcinoma, had a colloid nodular goiter. Of the 3 patients with atypia FNAs, one was found to be papillary carcinoma. One hundred twenty-five benign nodules (21 based on cytology and/or histology, 104 on clinical and imaging follow-up) were diagnosed. Nodule size, microcalcifications, solid parenchyma, and pathologic lymph node alterations were associated with malignancy, but nodule growth was not.Conclusion: Diagnostic approach and management of children with thyroid nodules should be based on a stepwise evaluation including clinical, laboratory, and US findings. Of the 102 patients identified, 4.9% had thyroid carcinoma below the range described in previous literature. What is Known: • Thyroid nodules are less frequent in children than in adults but more frequently malignant. Research on factors associated with malignancy have mostly been conducted in adults; further studies in pediatric thyroid nodules are warranted. What is New: • Microcalcifications, pathologic lymph node alterations, solid parenchyma, and larger nodule size are associated with malignant nodules, but nodule growth is not always suggestive of thyroid malignancy. The incidence of thyroid malignancy in this population was below the reported worldwide incidence in children with thyroid nodules.

Reference intervals for serum 17α-hydroxyprogesterone and ultrasonographic adrenal gland sizes in healthy newborns.

Background and objectives: Serum 17α- hydroxyprogesterone (17OHP) and bilateral adrenal sizes are pivotal for clinical practice in both diagnosis and treatment of congenital adrenal disorders during the first month of life. Our aims were to determine the reference ranges for serum 17OHP and bilateral adrenal gland sizes according to sex and age groups in healthy term newborns.Materials and methods: A total of 156 healthy newborns, aged 4-7 days (Group 1) or 26-30 days old (Group 2) were included in the study. Serum 17OHP concentration was measured in the morning by radioimmunoassay. The right and left adrenal glands' width, length, and depth were measured with ultrasonography by the same radiologist and the volumes were calculated.Results: The clinical characteristics and serum 17OHP concentrations were similar in male and female newborns. Percentiles for serum 17OHP concentration and the volume of adrenal glands according to age groups and sexes were obtained. Mean 17OHP concentration was 4.67 ± 2.6 ng/ml and 4.49 ± 2.7 ng/ml at the first and fourth week of life, respectively (p > .05). There was a significant decrease in adrenal sizes during the fourth week of life. There was no significant correlation between serum 17OHP concentration and adrenal gland sizes.Conclusions: We have determined reference intervals for serum 17OHP concentration and bilateral adrenal gland sizes for healthy newborns. Although serum concentrations of 17OHP did not change significantly through the first month of life, our reference intervals for serum 17OHP concentration and adrenal sizes may improve clinical approach toward newborns who are suspected of adrenal disorder. We conclude that our reference intervals can guide for congenital adrenal screening regarding serum 17OHP concentration besides diagnosis of adrenal hypoplasia or hyperplasia with ultrasonographic adrenal gland sizes.

Turkish Final Year Medical Students' Exposure to and Attitudes Concerning Drug Company Interactions: A Perspective from a Minimally Regulated Environment for Medical Students.

Interactions between drug companies and medical students may affect evidence-based medical practice and patient safety. The aim of this study was to assess drug company-medical student interactions in a medical faculty where limited specific national or institutional regulations apply between drug companies and medical students. The objectives of the study were to determine the exposure and attitudes of final year medical students in terms of drug company-medical student and physician interactions, to identify factors affecting those attitudes and to provide data for policymakers working on the regulation of interactions between drug companies and medical students. This anonymous questionnaire-based study of 154 medical final year medical students at the Karadeniz Technical University Medical Faculty, Trabzon, Turkey, in April and May 2015 attracted a response rate of 92.2% (n/N, 154/164). Exposure to interaction with a pharmaceutical representative was reported by 90.3% (139/154) of students, and 68.8% (106/154) reported experiencing such interaction alongside a resident. In addition, 83.7% (128/153) of students reported an interaction during internship. Furthermore, 69.9% (107/153) of students agreed that interactions influence physicians' prescription preferences, while 33.1% (51/154) thought that a medical student should never accept a gift from a drug company and 24.7% (38/154) agreed with the proposition that "drug companies should not hold activities in medical faculties". Students with rational prescription training expressed greater agreement with the statement "I am skeptical concerning the information provided by drug companies during interactions" than those who had not received such training, and this finding was supported by logistic regression [O.R.(C.I), p -3.7(1.2-11.5), p = 0.022]. Acceptance of advertisement brochures was found to significantly reduce the level of agreement with the proposition that "A physician should not accept any gift from a drug company." (0.3[0.1-0.9], p = 0.030). In summary, exposure to drug companies was widespread among our final year medical students who, like students in both Western and non-Western societies, hold permissive attitudes concerning accepting gifts, and drug advertising brochures may relax those permissive attitudes still further. Rational prescription training was useful in generating rational attitudes. Policies concerning drug company-medical student relationships should be developed in Turkey as well as internationally.

Validity and Reliability of the Turkish Version of Needs Based Biopsychosocial Distress Instrument for Cancer Patients (CANDI).

BACKGROUND: Needs based biopsychosocial distress instrument for cancer patients (CANDI) is a scale based on needs arising due to the effects of cancer. OBJECTIVES: The aim of this research was to determine the reliability and validity of the CANDI scale in the Turkish language. PATIENTS AND METHODS: The study was performed with the participation of 172 cancer patients aged 18 and over. Factor analysis (principal components analysis) was used to assess construct validity. Criterion validities were tested by computing Spearman correlation between CANDI and hospital anxiety depression scale (HADS), and brief symptom inventory (BSI) (convergent validity) and quality of life scales (FACT-G) (divergent validity). Test-retest reliabilities and internal consistencies were measured with intraclass correlation (ICC) and Cronbach-α. RESULTS: A three-factor solution (emotional, physical and social) was found with factor analysis. Internal reliability (α = 0.94) and test-retest reliability (ICC = 0.87) were significantly high. Correlations between CANDI and HADS (rs = 0.67), and BSI (rs = 0.69) and FACT-G (rs = -0.76) were moderate and significant in the expected direction. CONCLUSIONS: CANDI is a valid and reliable scale in cancer patients with a three-factor structure (emotional, physical and social) in the Turkish language.

Are the last grade medical students aware of the danger of synthetic cannabinoids?

Synthetic cannabinoids are drugs which are increasingly used by especially adolescents and young people. In recent years hospital admissions even concluding with deaths have been observed. Therefore, the awareness of medical students, who will be in challenge with this new drug abuse, is an important issue. The aim of this study is to figure out the awareness of the last grade medical students and its correlates. This is a questionnaire based descriptive study with the participation of 148 students at Karadeniz Technical University Medical Faculty, Turkey. An awareness score was produced to measure awareness (cronbach alpha = 0.67). The 17.6% (26/148) of students who reported not knowing what synthetic cannabinoids were and hearing the name for the first time in this study. The 16.4% of students assumed that synthetic cannabinoid use was legal, and 16.2% assumed that synthetic cannabinoids are not drugs. The internet (including social media) (48.6%) and pharmacology lectures (40.5%) were identified as the most stated sources of information. The students who have synthetic cannabinoid user friends and social media account have significantly higher awareness scores (p < 0.05 for both). Last grade medical students have a lack of awareness towards synthetic cannabinoids which is an increasing threat that they have to challenge.

Fatal poisoning of chilhood in the Eastern Black Sea region of Turkey (2009-2013).

Poisoning is a major problem worldwide among children. Nonetheless, the offending agent, the associated morbidity and mortality vary from place to place and show changes over a period of time. The aim of this study was to investigate the medico-legal paediatric autopsies of childhood poisonings in the Eastern Black Sea Region of Turkey. Reports of autopsies performed between 2009 and 2013 in the Morgue Department of the Council of Forensic Medicine. All medico-legal paediatric autopsies in Trabzon (n:1049) were retrospectively examined. The study comprised an investigation into 62 deaths from poisoning in children aged 0-18 years. The parameters of age, sex, toxic substance category and origin were evaluated. Poisoning accounted for 5.9% of the deaths of children aged 0-18 years. Of the 62 cases, 32 (51.6%) were male and 30 (48.4%) were female, giving a female to male ratio of 1/1.1. The primary causes of fatal poisoning in children were carbon monoxide (64.5%, n = 40), followed by drugs (16.1%, n = 10), insecticides (9.7%, n = 6), mushrooms (6.5%, n = 4), and snake venom (3.2%, n = 2). The results of this study implicated carbon monoxide poisoning as a serious risk factor for mortality in our region. Childhood poisoning may be prevented by public education and simple precautions in general.

The effect of ice skating on psychological well-being and sleep quality of children with visual or hearing impairment.

PURPOSE: Physical exercise and sports have a key role in preventing physical and psychiatric problems in children. However, children with a disability often experience difficulty participating in physical activity due to a lack of suitable opportunities. Participation in an accessible sport is particularly important for these children, but studies examining which sports are beneficial for which disability groups are rare. In this study, we assessed the effects of ice skating on the psychological well-being, self-concept, and sleep quality of children with hearing or visual impairment. METHOD: Forty students (20 visually impaired and 20 hearing impaired) aged 8-16 were included in a regular ice skating programme for three months. We examined the sleep quality, self-concept, and behavioural and emotional states of the children before and after participating in the programme. RESULTS: There was a significant improvement in self-concept, behavioural and emotional problems, and sleep quality (p < 0.05 for each) of the children with hearing impairment. Although the sleep quality (p = 0.019) and emotional problem scores (p = 0.000) of the visually impaired children improved; self-concept, peer relations and hyperactivity scores of these children worsened (p < 0.05 for each). CONCLUSION: Ice skating is one of the popular sport alternatives that gives children the opportunity to exercise and have fun together. The results of this study revealed that regular ice skating programmes may have positive effects on the psychological well-being of children with hearing impairment. Despite some positive effects, caution must be use when including visually impaired children in ice skating programmes. Generalization of the study's outcomes is limited as the study group were residential students enrolled in special education institutions for children who are blind or deaf. IMPLICATIONS FOR REHABILITATION: Ice skating is a community-based sport and a popular leisure activity that can also have benefits for people with disabilities. Ice skating and children with hearing impairment: Self-concept, behavioural and emotional problems, and sleep quality of the children with hearing impairment significantly improved after ice skating. Ice skating programmes may be considered as a rehabilitation alternative for children with hearing impairment. Ice skating and children with visual impairment: Caution must be use when including children with visual impairment in ice skating programmes because of possible negative psychological outcomes. Balance exercises before starting the practices on ice should be considered for preventing some possible negative outcomes in children with visual impairment.

Energy drink use in university students and associated factors.

The use of energy drinks is common among adolescents and young age groups. The purpose of this study was to determine energy drink consumption status in students at the Karadeniz Technical University in Turkey and the factors affecting this. The research was performed at the Karadeniz Technical University among a total of 2001 students attending the Administration Department, the Physical Education Department, the Psychological Counseling and Guidance Department and the Faculty of Medicine. The research data were collected using the supervised questionnaire method. The 53.5 % (n = 1070) of students had never tried energy drinks, 22.5 % (n = 450) had tried them once only, 1.5 % (n = 30) had used them for a time and then gave up, 21.1 % (n = 422) consumed occasionally and 1.4 % (n = 29) regularly. The risks of regular energy drink consuming were male gender [2.4 (1.8-3.2)] [OR (95 %CI)], studying at night [1.6 (1.2-2.2)], having friends consuming energy drinks [3.6 (2.6-5.0)], regular physical activity [1.9 (1.4-2.5)], being an alcohol drinker [2.4 (1.7-3.2)]. This study revealed that almost half of university students had experience of energy drinks and that approximately one-fourth still used them. It will be useful for these factors listed above to be borne in mind in the development of policies aimed at protecting young people from the health impacts of energy drinks.

Forensic child and adolescent psychiatry: from field experiences to education standards.

OBJECTIVE: Forensic evaluation of children is one of the most problematic areas of child and adolescent psychiatry. In this study we aimed to examine Turkish Child and adolescent psychiatrists' attitudes and problems in forensic psychiatry. METHOD: Thirty nine (80%) of all practitioners who are on their compulsory medical service programme countrywide were reached and requested to complete a questionnaire. RESULTS: 76.9% of the specialists found their education to be inadequate in dealing with practical issues. The most common reason of this inadequacy was endorsed as not receiving structured forensic evaluation training. The inadequate number or skills of health professionals from other disciplines and excessive workload were the leading factors mentioned as negatively affecting the quality of assessments. Most favoured solutions to solve current problems were reported as reorganising the residency training and curriculum of child and adolescent psychiatrists and establishing education programmes for other disciplines. CONCLUSION: The standardisation of forensic psychiatry education in child and adolescent psychiatry training and the establishment of global standards for forensic evaluation teams and processes should be considered as the first steps in enhancing the global quality of child and adolescent forensic psychiatric evaluations.

Willingness to Receive the Influenza A(H1N1) Vaccine and its Determinants among University Students during the 2009 Outbreak in Turkey.

OBJECTIVE: The study aimed to determine the willingness to receive the Influenza A(H1N1) vaccine and its determinants in a large group of university students. MATERIALS AND METHODS: This is a self-administered questionnairre based cross-sectional study. Students being educated at health and non-health faculties were invited to participate in this attitude survey. RESULTS: A total of 974 students were included in the study, of whom 51.3% (n=500) were in health related faculties. The rate of willingness to receive the Influenza A(H1N1) vaccine was 11.9 and 7.5% for health and non-health groups, respectively (p<0.05). For the health group, having been vaccined with seasonal influenza was a significant determinant of being willingness to receive the Influenza A(H1N1) vaccine (O.R [95% C.I.]), (O.R: 2.9 [1.5-5.6]) and to believe that the Influenza A(H1N1) vaccine prevents swine flu (O.R: 1.7 [1.09-2.8]). For the non-health group, the only determinant was to believe that Influenza A(H1N1) vaccine prevents from swine flu (O.R: 19.1 [5.7-64.1]) which found to be affected by confusing news in media. CONCLUSION: The public health professionals who will organize the efforts to improve the acceptability of Influenza A vaccines during influenza outbreaks should try to increase the vaccination rates of seasonal influenza. Information provided by the media should be organized in order not to cause fear and confusion, which was shown to decrease willingness and belief in the Influenza A(H1N1) vaccine.

Animal-related injuries: epidemiological and meteorological features.

This is a retrospective and registry-based descriptive study including animal- related injuries represented by the most crowded Emergency Department (ED) in Eastern Turkey over a period of two years. Animal-related injuries were 0.2% of all ED admittances; dominant in males and were high in summer. 68% of the subjects were exposed to mammalians. Most prominent injuries were dog bites (30%), horse (22%) and livestock-related injuries (12%). Hospitalization was significantly higher in mammalian animal injuries compared to non-mammalian injuries. The highest hospitalization rate was measured for equine-related injuries (15%). In our bite series, dogs were the primary source (69%) while horse-bites (17%) took the second place and they were more than two fold more when compared with cats (7.5%). Dog bites were prominent in children, thus both parents and children should be educated. Insect and snake-related injuries were both low in number and relatively silent in prognosis. Highest temperatures on site were determined for tick-bites, unspecified insect stings and bee stings, respectively. The highest humidity was determined for dog-bites, cat-bites and scorpion stings, respectively. Nonmammalian and sting injuries had higher temperature and lower humidity measurements compared to mammalian and bite injuries. Geographical and meteorological factors may directly affect descriptive epidemiology of animal-related injuries.

Interactions between exhaled CO, smoking status and nicotine dependency in a sample of Turkish adolescents.

The aim of this study was to show the interactions between nicotine dependency, exhaled carbon monoxide (CO) and smoking status including environmental passive tobacco smoke exposure in a sample of Turkish adolescents. This study was a cross-sectional research conducted among high school students of Erzurum province (n=536). The level of exhaled CO of all participants who accepted to participate in the study was measured by Microbio CO Analyzer (Microbio Med). Nicotine dependency was measured by a six-item version of the Fagerstrom Tolerance Questionnaire. Mean age of the adolescents was 17.0 +/- 1.6 (median: 17) and 77.1% were male. Of the study population, 30.2% and 11.4% of the students were regular and occasional smokers, respectively. Non-smokers who were exposed to environmental tobacco smoke had significantly (p<0.01) higher exhaled CO levels (2.8 +/- 2.6 ppm) than not-exposed non- smokers (1.8 +/- 1.9 ppm). Only 8.6% of adolescents who reported themselves to be a regular smoker had 7 ppm and higher exhaled CO. There was a statistically significant and positive correlation between exhaled CO levels and nicotine dependency after controlling for environmental tobacco smoke exposure and cigarettes per day (partial correlation, r=0.334, p=0.004). Exhaled CO can be used as a predictor of smoking status and environmental tobacco smoke exposure and an indicator of nicotine dependency in adolescents.