Investigating the synergistic effect of socio-demographic fac- tors on behaviors and attitudes concerning alcohol and illicit drug use among Italian students: a large cross-sectional study.

Background: Alcohol, drug consumption and polysubstance use are some of the most important causes of illnesses and mortality among adolescents, who have been identified as common users of these substances. Aim of this study was to assess and describe the current scenery of alcohol and other drugs consumption habits among a wide sample of Italian high school and university students. Methods: A cross-sectional study was carried out using an online survey. The questionnaire was developed and administered via an internet forum for middle school, high school and university students named "Skuola.net". The statistical analysis included descriptive statistics, univariate and multivariate analysis. Additive interactions were assessed by calculating the synergy index. Results: A total of 11,379 Italian students answered the questionnaire. The prevalence of alcohol drinkers was 34.2%; among these, 17.8% of the individuals showed unhealthy drinking behaviors (frequency of alcohol use of four times or more per week); 10.3% of individuals declared daily assumption of six or more glasses of alcohol. Concerning drugs, 15.7% of the responders classified themselves as illicit drug users, with cannabis getting the highest prevalence rates (6.9%). Finally, concerning alcohol, a synergistic effect was recorded for male and adult individuals (SI = 1.04); while concerning illicit drugs, a synergistic effect was found between male gender and older age (SI = 1.42), and between university students and male gender (SI = 1.10). Conclusions: This study gives an overview about the attitudes of a wide sample of Italian students concerning alcohol and drugs habits. These results are in line with evidences from the scientific literature and will be helpful for developing future prevention strategies towards this target population.

Compliance with the school smoking ban: A cross-sectional study from Italy.

BACKGROUND: In 2015, 37% of Italian adolescents reported to have smoked in the past month. The study aimed to evaluate smoking beha-viour on the school premises and to study the influence of the school environment on student smoking. METHODS: Around 900 junior high-school students, aged 11-13 years old completed an online survey in November 2016 and May 2017. Descriptive statistics, univariate analyses and binary logistic regression were performed to analyse data. RESULTS: Between 40 - 50% of students indicated that students and staff smoke on the school premises. Students who witnessed students (OR: 3.48 (2.20 - 5.50)) and school employees (OR: 3.17 (1.97 - 5.10)) smoking were more likely to be a smoker. CONCLUSION: Although laws making it illegal to smoke on the school ground are in place, in Italy, its enforcement is sloppy. To tackle adolescent smoking effectively, policymakers are advised to enforce smoking restrictions and to verify these are respected.

Link between perceived smoking behaviour at school and students smoking status: a large survey among Italian adolescents.

OBJECTIVES: To investigate a possible link between sociodemographic factors, the perception of smoking habits at school and smoking status of Italian adolescents attending secondary school. STUDY DESIGN: The study was a cross-sectional study. METHODS: An anonymous online survey was employed to gather information on age, gender, smoking status and to examine the perception of smoking behaviour on the school premises. Chi-squared and Kruskal-Wallis tests were performed for the univariate analysis and logistic and multinomial regressions for the multivariate analysis. RESULTS: The statistical analyses included 1889 students. Univariate analysis showed significant differences concerning knowledge between smoker and non-smoker concerning the harmfulness of smoking (P < 0.001). According to the multivariate analysis smokers had a higher perception of teacher, principal or janitor smoking at school (odds ratio: 1.54 [95% confidence interval 1.26-1.89]). Students older than 19 years most often begin smoking because their friends smoke compared with younger students (adjusted odds ratio: 1.18 [95% confidence interval 0.48-2.89]). CONCLUSION: School environment and behaviour of role models play a crucial part in student smoking. To prevent and reduce youth tobacco smoking, not merely the presence of preventive measures is important but greater attention needs to be placed on the enforcement of smoking policies.

Differences between ranamargarin and other tachykinins in the stimulation of ion transport in frog skin.

In frog skin, tachykinins stimulate ion transport by interaction with NK1-like receptors. The structural requirements of the peptide are the presence of the C-terminal sequence Phe-X-Gly-Leu-Met-NH(2) and at least one Pro residue in the N-terminal sequence. In this paper, we demonstrate that the C-terminal amino acid must be amidated but it can be different from Met, and that the sequence cannot be longer or shorter than 11-12 amino acids. Unexpectedly, Ranamargarin (14 amino acids, no Pro residue) increased the short circuit current value by 48 +/- 0.3%. On the basis of considerable experimental evidence, we suggest that Ranamargarin interacts with a receptor different from those of other tachykinins.

Actions of tachykinins on the ion transport across the frog skin.

The tachykinin-dependent stimulation of ion transport across frog skin was studied. Tachykinin stimulation was due to interaction with an NK1-like receptor as [Sar9-Met(O2)11]-Substance P (a very selective NK1 agonist) strongly stimulated SCC, whereas [beta-Ala8]-Neurokinin A 4-10 (a very selective NK2 agonist) did not. The rank order of tachykinin potency was: PG-KI > Uperolein > Hylambatin > Kassinin > Phyllomedusin > [Sar9-Met(O2)11]-Substance P > Ranatachykinin A > Physalaemin > Ranakinin > Substance P and Eledoisin >> Neurokinin A. Neurokinin B, Scyliorhinin I, Urechistachykinin I and Urechistachykinin II had no effect. We conclude that the minimal structural requirements for stimulating SCC in the frog skin were the presence of: a) the C-terminal sequence Phe-X-Gly-Leu-Met-NH2; b) at least one Pro residue in the N-terminal sequence.

Action of physalaemin on the ionic transport across the frog skin.

The effects of the non-mammalian tachykinin physalaemin were studied on the short circuit current (SCC) and on both influx (Ji) and outflux (Jo) of 36Cl- and 22Na+ across the isolated skin of Rana esculenta. Physalaemin, added to the internal bathing fluid, increased SCC in a dose-dependent manner with a maximal effect at 1 microM. This increase was due to a stimulation of both Na+ absorption and Cl- secretion. Bumetanide (20 microM in the internal fluid), an inhibitor of the Na+/K+/2Cl- cotransporter, reduced the action of physalaemin on SCC by 46%. Furthermore diphenylamine-2-carboxylic acid (DPC, 0.1 mM in the external fluid), an inhibitor of Cl- channels, decreased the effect of the peptide on SCC by 48%. It is concluded that physalaemin activates the Na+/K+/2Cl- cotransporter at the basolateral membrane, accumulating Cl- in the cells and favouring its exit through Cl- channels at the outermost membrane of the epithelium. An inhibitor of cyclooxygenases, i.e. naproxen, strongly inhibited the physalaemin effect on SCC, whereas 5,8,11-eicosatriynoic acid (ETI), an inhibitor of lipooxygenases was without effect. Therefore, it is proposed that prostaglandins (probably PGE2) are the cellular mediators of this action. An antagonist of NK1 receptors for tachykinins, CP 99,994, inhibited the physalaemin action on SCC, whereas challenge with SR 48,968, an antagonist of NK2 receptors, had no effect on physalaemin action. It is concluded that physalaemin effect on SCC in frog skin is mediated by its interaction with NK1 receptors.

Cyclosporin A stimulates Na+ transport across the isolated skin of Rana esculenta.

Cyclosporin A (Cs A), added to the fluid bathing the internal surface of the isolated skin of Rana esculenta, increased short-circuit current (SCC) with a maximal effect at 5 microM. This effect was completely inhibited by amiloride (0.2 mM in the fluid bathing the external surface). By measuring both transepithelial fluxes of 22Na+ across symmetrical parts of the short circuited skin, Cs A was found to increase the net absorption of Na+. Naproxen (10 microM), a cyclooxygenase inhibitor, decreased the stimulation by Cs A of SCC, suggesting that in this stimulation prostaglandins are involved. The Cs A effect on Na+ transport could be caused by an inhibition of a Ca2+/calmodulin-dependent protein phosphatase, i.e. calcineurin, since: a) it is mimicked by another inhibitor of calcineurin, i.e. fenvalerate: b) the action of Cs A and fenvalerate on SCC are decreased by the calmodulin inhibitor W7.

Effect of calcitonin gene-related peptide on sodium absorption through isolated skin of Rana esculenta.

Calcitonin gene-related peptide (CGRP) added to the internal fluid bathing the isolated skin of Rana esculenta strongly stimulates the active sodium absorption. This action is dose-dependent, the dose eliciting the maximal effect being 2 . 10(-7) M; alpha and beta CGRP exhibit the same potency. The CGRP action on sodium transport is mainly due to its interaction with CGRP1 receptors, since it is inhibited by CGRP8-37, its specific antagonist. The second messengers probably involved in the action of CGRP are cAMP and Ca+2, since this action is reduced by SQ22536 and W7, which are inhibitors of adenyl cyclase and calmodulin respectively. On the contrary, inhibitors of protein kinase C (1-O-hexadecyl-2-O-methyl-sn-glycerol) and nitric oxide synthase (L-NAME) do not modify the action on sodium transport. ETYA, an inhibitor of all the metabolic pathways of arachidonic acid, decreases the CGRP action by 38%. In order to search for the arachidonic acid metabolites involved in the CGRP action, the effect of the following inhibitors was tested: aspirin and naproxen (for cyclooxygenases), NDGA (for cyclooxygenases), NDGA (for lipoxygenases) clotrimazole (for epoxygenases). None of these substances is able to inhibit the CGRP action on sodium transport. Moreover, adding arachidonic acid inhibits the CGRP action, but this effect was also obtained by another unsaturated fatty acid, oleic acid. Since unsaturated fatty acids are able to inhibit the protein kinase A, these results indirectly support the role of cAMP as a second messenger of the CGRP action on sodium transport.

Na+ and Cl- net absorption by the isolated skin of Rana esculenta.

In the last five years, several measurements of 22Na+ influx (Ji) and outflux (Jo) across symmetrical parts of the isolated skin of Rana esculenta, under permanent short circuitation, were performed in our Institute. The mean value of the 22Na+ net fluxes (Ji-Jo) exceeded the mean value of the short circuit current measurements (1.14 +/- 0.04 versus 0.98 +/- 0.02 microE.cm-2.h-1, 253 experiments). Since this discrepancy could be due to a concomitant Cl- net absorption, 36Cl- unidirectional fluxes were detected under similar experimental conditions. The Cl- net flux mean value was 0.11 +/- 0.02 microE.cm-2.h-1 (316 experiments) which accounts for 70% of the discrepancy between the Na+ net flux and short circuit current. This Cl- net absorption occurred in the absence of electrochemical gradients and was very likely maintained by a Na+/K+/2Cl- cotransport located at the outermost membrane of the epithelium. In fact bumetanide challenge (10(-5) M in the external fluid) strongly inhibited 36Cl- influx and 22Na+ influx across this tissue and cleared off the discrepancy between short circuit current and sodium net flux.

Action of dopamine on the ionic transport across the isolated skin of Rana esculenta.

Dopamine addition to the internal fluid bathing the isolated frog skin results in a strong increase of short circuit current (SCC) across this tissue. The effect is dose-dependent, 10(-4) M being the dose resulting in maximal effect. The measure of transepithelial fluxes of both 22Na+ and 36Cl- across symmetrical parts of skin short-circuited in permanence demonstrates that this effect is due to stimulation of Na+ adsorption and Cl- secretion. The former effect, but not the latter one, is mimicked by both SKF89124A and SKF82525J (D1 and D2 agonists, respectively). Moreover the effect of dopamine on SCC and Na+ net flux is wider than that of its synthetic agonists even when both D1 and D2 agonists were added together. It is suggested that the extraeffect of dopamine on SCC is due to a stimulation of Cl- secretion, probably mediated by dopamine interaction with another receptor.

Action of capsaicin and related peptides on the ionic transport across the skin of Rana esculenta.

Capsaicin at low concentrations increases the short circuit current (SCC) across frog skin. Simultaneous measurements of both transepithelial fluxes of 22Na or 36Cl demonstrate that the SCC increase is due to stimulation of sodium active absorption. Capsaicin acts through the liberation of several peptides; thus these peptides were tested on the SCC across frog skin. Those more active are, in order of potency: Cyclic Calcitonin Gene Related Peptide (CGRP), Kassinin and Eledoisin, Substance P (SP) and Neurokinin A. Neurokinin B and Vasoactive Intestinal Peptide (VIP) have no effect. Also the actions of SP and CGRP are due mainly to stimulation of Na+ active absorption. A strict parallelism regarding the sensitivity to inhibitors (Naproxen, SQ22536 and CP96345) between SP, CGRP and Capsaicin strengthens the hypothesis that SP and CGRP are liberated by Capsaicin in this tissue.

The nature of Cl- secretion, induced by carbaryl, across the isolated skin of Rana esculenta.

1. The pesticide carbaryl induces Cl- secretion through the isolated frog skin. 2. This effect is due to the activation of both processes responsible for this phenomenon: (a) Na+/K+/2Cl- cotransport on the serosal membrane; (b) Cl- selective channels on the external membrane. 3. Cl- outflux is inhibited by bumetanide (10(-5) M) on the serosal side and by diphenylamine-2-carboxylic acid (DPC) (10(-3) M) on the external side. 4. The DPC action is not mimicked by Naproxen, a specific inhibitor of cyclooxygenase. 5. A comparison with isoprenaline, demonstrates that the carbaryl action is, paradoxically, more selective than that of isoprenaline. 6. This selectivity of carbaryl action on Cl- permeability is confirmed by the fact that, unlike isoprenaline, carbaryl does not affect the permeability of Na+ and thiourea.

Beta 2-adrenergic regulation of urea permeability of the Bufo bufo bladder.

1. Isoprenaline strongly increases the urea permeability of the bladder of Bufo bufo. This effect is due to its interaction with beta 2-adrenoreceptors, activating, in turn, the adenyl cyclase. 2. In order to ensure the regulation of urea permeability, the isoprenaline effect is present even in pathophysiological conditions, inhibiting the vasopressin action.

Actions of vasopressin and isoprenaline on the ionic transport across the isolated frog skin in the presence and the absence of adenyl cyclase inhibitors MDL12330A and SQ22536.

1. The effects of both adenyl cyclase inhibitors (MDL12330A and SQ22536) have been studied on the ionic transport induced by vasopressin and isoprenaline across the frog skin. 2. MDL12330A inhibits the vasopressin action on the short-circuit current (SCC), confirming that this effect is cAMP-mediated. 3. On the other hand, isoprenaline action on the SCC is unaffected by MDL12330A. However, this lack of effect is not a sufficient argument against the role of cAMP in this action; in fact, as MDL12330A is also an inhibitor of cAMP phosphodiesterase, this action could mask the inhibitory effect of the drug on adenyl cyclase. 4. By using the other adenyl cyclase inhibitor (SQ22536), probably deprived of effect on the cAMP phosphodiesterase, we obtained a strong inhibition of isoprenaline action on the SCC. Thus we conclude that the actions of isoprenaline on the ionic transport across the frog skin are also cAMP-mediated.

Actions of carbaryl on the ionic transport across the isolated skin of Rana esculenta.

1. Carbaryl, a carbamate used as a pesticide, increases the short-circuit current (SCC) across the isolated frog skin in a dose-dependent manner. 2. This effect is due to the stimulation of sodium absorption and chloride secretion. 3. Carbaryl action on short-circuit current is unrelated to its inhibitory power on cholinesterase; this statement is supported by two experimental results: (a) carbaryl is equally active on both sides of the skin, (b) atropine pretreatment does not inhibit the carbaryl action on SCC.

Permeability properties of the Bufo bufo bladder as affected by isoprenaline and vasopressin.

Isoprenaline, a beta adrenergic agonist, strongly increases both transepithelial fluxes across the urinary bladder of Bufo bufo; this effect is dose dependent, 10(-6)M being necessary for the maximal action. This effect is less selective than that of vasopressin: the ratio J urea/J thiourea is 3.8 under isoprenaline and 30.4 under vasopressin treatment. Both hormones differently affect the permeability of a mainly liposoluble molecule, i.e. antipyrine: vasopressin increases antipyrine permeability, while isoprenaline decreases it. Moreover diethylpyrocarbonate treatment of the luminal membrane strongly inhibits vasopressin effect on urea permeability leaving unmodified that of isoprenaline. However, the actions of both hormones are not additive. These results allows to assume that the tissue has a feedback mechanism which inhibits other hormonal action while the bladder is stimulated by a particular hormone.

Diazepam effects on frog skin cyclic nucleotide phosphodiesterase.

1. The activities of cAMP phosphodiesterases (cAMP-PDE) have been measured in the homogenate of the skin of Rana esculenta. 2. The tissue possesses two distinct enzymes: a "low" Km PDE (Km = 0.42 x 10(-6) M; Vmax = 16 pmol/mg protein/min) and a "high" Km PDE (Km = 180 x 10(-6) M; Vmax = 2853 pmol/mg prot/min). Only the "high" Km form is stimulated by calcium. 3. Diazepam (1-0.5 mM) significantly inhibits both enzymes, the inhibition being of competitive type.

Action of forskolin on non-electrolyte permeability across the urinary bladder of Bufo bufo as compared to that of various hormones.

1. Forskolin, an activator of adenyl-cyclase in a receptor-independent manner, mimics the ADH effect on the urea and thiourea permeabilities across the toad bladder. 2. However, differently from ADH, forskolin increases the erythritol permeability across the tissue and this effect is not reproduced by two substances increasing the urea permeability (8-BrcAMP and isoprenaline). Most probably this effect of forskolin does not involve the cAMP generating system.

Effect of reagents of protein functional groups on the ADH-induced urea facilitated transport across toad urinary bladder.

1--The mechanism of the vasopressin-induced, facilitated transport across toad urinary bladder was studied by treating the luminal membrane of the epithelium with the following reagents of protein functional groups: NEM (SH groups), SITS (amino groups), EEDQ (carboxylic groups), DEPC (histidine). 2--Treatment of the luminal side of the epithelium by NEM strongly inhibits the ADH-induced urea transport, leaving unmodified the effect of the hormone on the flux of antipyrine, a lipid soluble molecule. These results confirm the hypothesis that the urea carrier is of proteic nature. 3--Treatment of the luminal side by SITS strongly inhibits ADH action on urea and antipyrine permeability; thus this effect can be considered rather unspecific. 4--On the contrary the EEDQ effect is more specific; in fact treatment of the luminal side by EEDQ strongly inhibits ADH effect on the permeability of urea, slightly increasing the ADH effect on that of antipyrine. 5--Finally, the luminal treatment by diethylpyrocarbonate inhibits almost completely the ADH action on the urea fluxes, slightly increasing the hormone effect on the antipyrine ones. 6--Based on these results we conclude that carboxylic groups and the imidazolic ring are more important than the amino groups in determining the urea transport across toad bladder, in the presence of ADH.