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Substance use behaviours have been found to cluster in youth, and cannabis use has been previously linked to tobacco and e-cigarette use. The objective of the current study was to examine the bidirectional associations between cannabis, e-cigarette, and cigarette use among a large sample of Canadian secondary school students. A sample of students in grades 9–11 (n = 14,652) from Ontario and Alberta, Canada who participated in two waves of the COMPASS Study (Time 1 (T1): 2015–2016; Time 2 (T2): 2016–2017) was identified. Autoregressive cross-lagged models investigated the stability of product use between T1 and T2, as well as the bidirectional associations between current cannabis, e-cigarette, and cigarette use while controlling for demographic covariates. Significant autoregressive and bidirectional associations between all three substances were observed. Students who reported using cigarettes and e-cigarettes at T1 were more likely to report using cannabis at T2. Similarly, students who reported using cannabis at T1 were more likely to report using cigarettes and e-cigarettes at T2. Given the bidirectional associations identified between cannabis, e-cigarette, and cigarette use in this research, continued monitoring of evolving policies related to cannabis and e-cigarette use in Canada is needed. Additionally, school and community-based prevention efforts targeting youth should consider addressing poly-substance use.

Following cannabis legalization in Canada, a better understanding of the prevalence of unprompted cannabis use reduction and subsequent effects on youth academic outcomes is needed to inform harm reduction and health promotion approaches.We analyzed a longitudinally linked sample (n = 91774) from the COMPASS prospective cohort study of Canadian high school students attending Grades 9-12 in Ontario and Alberta between 2013-2014 and 2016-2017. We investigated the prevalence of spontaneous cannabis use reduction and cessation between grade transitions (Grades 9-10, 10-11, 11-12) and the effect of cessation on academic achievement (current or recent math and English course marks) and rigour (usual homework completion and past-month truancy).Only 14.8% of cannabis users decreased their use between grades. Of these, two-thirds made only incremental downward changes, a pattern which held true for all three transitions. Cessation rates from daily and weekly use decreased every year. After cessation, students had better odds than continuing users (OR = 1.23, 95% CI: 1.03- 1.48) and worse odds than never-users (OR = 0.55, 95% CI: 0.31-0.97) for some subcategories of math performance. Students who quit cannabis universally improved class attendance (OR = 2.48, 95% CI: 1.93-3.19) and homework completion (OR = 2.32, 95% CI: 1.85-2.92) compared to continuing users.Increased academic rigour may underlie any improvements seen in academic performance after cannabis cessation. High school students who use cannabis likely need targeted support to facilitate reduction or cessation and subsequent academic recovery. This indicates that a school-based focus on cannabis harm reduction is justified.La légalisation du cannabis au Canada requiert une meilleure compréhension de la prévalence de la réduction volontaire de la consommation de cannabis et des effets subséquents sur les résultats scolaires des jeunes, afin d’éclairer les approches de réduction des méfaits et de promotion de la santé.Nous avons analysé les données longitudinales jumelées d’un échantillon (n = 91 774) tiré de l’étude de cohorte prospective COMPASS menée auprès d’élèves canadiens de la 9e à la 12e année de différentes écoles secondaires de l’Ontario et de l’Alberta, entre 2013­2014 et 2016­2017. Nous avons étudié la prévalence de la réduction et de l’abandon spontanés de la consommation de cannabis d’une année scolaire à l’autre (de la 9e à la 10e année, de la 10e à la 11e année, de la 11e à la 12e année), ainsi que l’effet de l’abandon sur la réussite scolaire (notes actuelles ou récentes obtenues en mathématiques et en anglais) et la rigueur (fréquence de réalisation des devoirs et absentéisme au cours des derniers mois).Seulement 14,8 % des consommateurs de cannabis ont réduit leur consommation d’une année scolaire à l’autre. De ce nombre, les deux tiers n’ont apporté que des changements progressifs à la baisse, une tendance qui s’est maintenue au fil des trois changements d’année scolaire. Les taux d’abandon à la suite d’une consommation quotidienne et hebdomadaire ont diminué d’une année à l’autre. Les élèves qui ont cessé de consommer du cannabis ont obtenu de meilleurs résultats que ceux qui ont continué à en consommer (rapport de cotes [RC] = 1,23, intervalle de confiance [IC] à 95 % : 1,03 à 1,48) et ils ont obtenu de moins bons résultats, dans certaines souscatégories de rendement en mathématiques, que ceux qui n’en ont jamais consommé (RC = 0,55, IC à 95 % : 0,31 à 0,97). Comparativement aux élèves qui ont continué à consommer du cannabis, ceux qui ont cessé ont tous amélioré leur assiduité aux cours (RC = 2,48, IC à 95 % : 1,93 à 3,19) et la réalisation de leurs devoirs (RC = 2,32, IC à 95 % : 1,85 à 2,92).Une plus grande rigueur scolaire pourrait être à l’origine des améliorations constatées dans le rendement scolaire après l’abandon du cannabis. Les élèves du secondaire qui consomment du cannabis auront probablement besoin d’un soutien ciblé afin de favoriser la réduction ou l’abandon de la consommation et le rétablissement scolaire subséquent. Il paraît donc justifié de mettre l’accent sur la réduction des effets nocifs du cannabis en milieu scolaire.Cannabis use change was investigated in a large sample of high school students. Only 14.8% who used cannabis reduced their use between grades. Most use reductions were incremental. Class attendance and homework completion universally improved after cessation. Cessation was not sufficient to improve academic performance (course marks). Targeted support for high school students who use cannabis is needed.La modification de la consommation de cannabis a fait l’objet d’une étude auprès d’un large échantillon d’élèves du secondaire. Seulement 14,8 % des élèves consommant du cannabis ont réduit leur consommation d’une année scolaire à l’autre. Dans la plupart des cas, la réduction de la consommation a été progressive. L’assiduité aux cours et la réalisation des devoirs ont été améliorées chez tous les élèves qui ont cessé de consommer du cannabis. L’arrêt de la consommation n’a pas suffi à améliorer le rendement scolaire (notes obtenues dans les cours). Il est nécessaire d’offrir un soutien ciblé aux élèves du secondaire qui consomment du cannabis.

Background and Objectives : Failure to gain weight (FTG) is one of the predominant health issues in children. The aim of this study is application of longitudinal transition model in determining the prognostic factors for failure to gain weight in children under two years. Methods: In this study, 363 children under 2 years that were visited at the health centers in the east of Tehran were studied. Samples were selected using the two stage clustering method. The study variables were measured repeatedly in 18 consecutive times. Since the data was longitudinal and are dependent, first order transition model was used to determine the risk factors of failure to gain weight. All analyses conducted in R. Results : The mean (±sd) birth weight was 3057gr(± 838) and 6.9% of the children weighed less than 2500gr at birth. Moreover, 231 children (63.6 %) had no FTW until 2 years of age while 23 ( 6.3 %) had three or more episodes of FTW. Diarrhea (P

Aims and background Identifying the risk factors of recurrence of breast cancer is important for both the physician and patient. Analysis of the first recurrence may lead to an inaccurate evaluation of the factor's effects because it does not completely reflect the history of the disease and may result in the loss of valuable information. The present study aimed to determine the factors that influence breast cancer recurrence and to estimate disease-free survival, adjusting for multiple metastases in breast cancer patients. Methods and study design Patients were selected from a longitudinal study carried out at Fayazabakhsh Hospital in Tehran, Iran. Women who were diagnosed with breast cancer and who underwent either modified radical mastectomy or breast-conserving surgery between January 2006 and April 2008 were recruited to take part in the study. Breast cancer recurrence was defined as the occurrence of a tumor in the contralateral breast, local-regional relapse, or distant metastasis to other organs. Using an extended Cox model, the effect of age, tumor size, estrogen receptors, HER2, progesterone receptors as well as lymph node ratio was analyzed. Results Over a 5833 person-month follow-up, 25 of 133 patients (18.8%) had died and 108 patients (81.2%) were still alive, 9 of them with metastasis. Thirty-four patients (25.6%) experienced their first disease recurrence. A total of 11 patients had a second metastasis. The mean time to first metastasis was 19.93 months, and mean gap time between two metastases was 7.15 months. Risk of experiencing a metastasis or death in the third and fifth year after surgery was approximately 22% and 28%, respectively. Fitting multiple recurrent regression shows that high lymph node ratio, high histologic grade, large tumor size and HER2-positive tumors are prognostic factors for shorter disease-free survival. Conclusions Our novel approach might be helpful in clinical practice to predict breast cancer recurrence after surgery and might be adapted to be used in other malignancies as well.

Gracilariopsis Persica (Rhodophyta) is one of the most abundant algae, introduced newly from the Indian Ocean. In this study, the main sterols of the algae have been isolated and identified. Separation and purification of the compounds was carried out on silica gel and sephadex LH20 column chromatography (CC) and high performance liquid chromatography (HPLC) to obtain five pure compounds 1-5. Structural elucidation of the compounds was based on the data obtained from H-NMR, (13)C-NMR, DEPT and Mass spectroscopy. The separated compounds from Gp. Persica were identified as 22-dehydrocholesterol (1), cholesterol (2), stigmasterol (3), β-sitosterol (4) and fucosterol (5) based on the spectral data compared to those reported in literatures. Most of these sterols are noteworthy for their effectiveness in decreasing the plasma cholesterol, glucose and inflammation. The results of Brine Shrimp Cytotoxicity Assay indicated that the ethyl acetate extract of Gp. Persica showed a high cytotoxic effect against A. salina nauplii (LC50 = 4 μg/mL). The methanol extract was no effective but the aqueous methanol extract was moderately effective (LC50 = 40 μg/mL) compared to berberine hydrochloride as a positive control (LC50 = 26 μg/mL).

Background: Salvia limbata is an aromatic herbaceous plant and grows widely in Iran Turkey and Afghanistan. In the previous study, six flavones together with rosmarinic acid were isolated from the ethyl acetate and methanol extracts of S. limbata. In this report, we focused on the isolation and identification of the glycosylated sterols and the main accumulated amino acid of the species S. limbata, which has not been previously reported. Methods: Aerial parts of the plant were dried, cut into small pieces and extracted with ethyl acetate and methanol by percolation at room temperature. The separation process was carried out using several chromatographic methods. Structural elucidation was based on NMR data, in comparison with those reported in the literature. Results: The isolated compounds (Figure 1) from the ethyl acetate and MeOH extracts of S. limbata were identified as beta-sitosterol (1), stigmasterol (2), daucosterol (3), stigmasterol 3- O-glucoside (4) and tryptophan (5) by comparison of their NMR spectral data with those reported in the literature Conclusions: S. limbata can accumulate the tryptophan as a major free amino acid together with sterols and their glucosides. Therefore, consumption of S. limbata (as a herbal tea or other preparations), which contains the essential amino acid tryptophan, might be useful for dietary deficiency of tryptophan.

Background and the purpose of the study The species Hymenocrater calycinus, belongs to the plant family Lamiaceae and grows wildly in the north-east of Iran. Previously, the antimicrobial activity of the plant extracts was reported. In the present study, the bioactivity-guided fractionation of the methanol extract of H. calycinus and the combination effects of the isolated compound with cell wall active agents against S. aureus and E. coli was investigated. Methods Column and thin layer chromatographic methods were used for isolation and purification and spectroscopic data (MS, 1H- and 13C-NMR, HMQC, HMBC and 1H-1H COSY) were employed for identification of the compound isolated from the extract. A disk diffusion method was used to determine the antibacterial activity of the isolated compound against S. aureus and E. coli in comparison with 7 different antibiotics. Results The isolated compound 1 was identified as 3-(3, 4- dihydroxyphenyl) lactic acid 2-O-quinic acid. Compound 1 (500 µg/disc) enhanced antibacterial effect of ampicillin, ciprofloxacin, vancomycin and cefepime against S. aureus and activated the effects of ampicillin and vancomycin against E. coli. Conclusion Results showed that the compound 1 was not active against both tested strains at any concentration below 1 mg/disk, and as a result the enhancing effect of the compound could be due its association with antibiotics.