Pulmonary functions of narghile smokers compared to cigarette smokers: a casecontrol study

Background: Studies of the lung function profiles of exclusive narghile smokers (ENS) are few, have some methodological limits, and present contradictory conclusions. The present study aimed to compare the plethysmographic profiles of ENS with age- and height-matched exclusive cigarette smokers (ECS).Methods: Males aged 35-60 living in Sousse, Tunisia, who have been smoking narghile exclusively for more than 10 narghile-years (n=36) or cigarettes exclusively for more than 10 pack-years (n=106) were recruited to participate in this casecontrol study. The anthropometric and plethysmographic data were measured according to international recommendations using a body plethysmograph (ZAN 500 Body II, Meβgreräte GmbH, Germany). Large-airway-obstructive-ventilatory-defect (LAOVD) was defined as: first second forced expiratory volume/forced vital capacity (FEV1/FVC) below the lower-limit-of-normal (LLN). Restrictiveventilatory- defect (RVD) was defined as total lung capacity <LLN. Lung hyperinflation was defined as residual volume>upper-limit-of-normal. Student t-test and x2 test were used to compare plethysmographic data and profiles of the two groups.Results: The subjects in the ENS and ECS groups are well matched in age (45+7 vs. 47+5 years) and height (1.73+0.06 vs. 1.72+0.06 m) and used similar quantities of tobacco (36+22 narghile-years vs. 35+19 packyears). Compared to the ENS group, the ECS group had significantly lower FEV1 (84+12 vs. 60+21%), FVC (90+12 vs. 76+18%), and FEV1/FVC (99+7 vs. 83+17%). The two groups had similar percentages of RVD (31 vs. 36%), while the ECS group had a significantly higher percentage of LAOVD (8 vs. 58%) and lung hyperinflation (36 vs.57%).Conclusion: Chronic exclusive narghile smoking has less adverse effects on pulmonary function tests than chronic exclusive cigarette smoking.Keywords: plethysmography; tobacco; narghile; tabamel; agein

Production and partial characterization of chitinase from a halotolerant Planococcus rifitoensis strain M2-26

peer reviewedThis paper is the first to investigate the production and partial characterization of the chitinase enzyme from a moderately halophilic bacterium Planococcus rifitoensis strain M2-26, earlier isolated from a shallow salt lake in Tunisia. The impact of salt, salinity concentration, pH, carbon and nitrogen sources on chitinase production and activity have been determined. This is the first report on a high salt-tolerant chitinase from P. rifitoensis, since it was active at high salinity (from 5 to 30% NaCl) as well as in the absence of salt. This enzyme showed optimal activity at 70 C and retained up to 82 and 66% of its original activity at 80 or 90 C, respectively. The activity of the enzyme was also shown over a wide pH range (from 5 to 11). For characterization of the enzyme activity, the chitinase secreted in the culture supernatant was partially purified. The preliminary study of the concentrated dialysed supernatant on native PAGE showed at least three chitinases produced by strain M2-26, with highest activity approximately at 65 kDa. Thus, the thermo-tolerant and high salt-tolerant chitinases produced by P. rifitoensis strain M2-26 could be useful for application in diverse areas such as biotechnology and agro-industry

An incidental finding of retroperitoneal paraganglioma during the coronavirus disease 2019 pandemic: a case report

Abstract Background Extra-adrenal paraganglioma of the retroperitoneum is a very rare neoplasm arising from cells of the primitive neural crest. Although paragangliomas are considered benign and are often found incidentally, they have the potential to metastasize. Case presentation We report the case of a 68-year-old Caucasian woman with an incidental diagnosis of retroperitoneal paraganglioma that was discovered on chest computed tomography performed for high suspicion of coronavirus disease 2019 pneumonia. The patient showed no metastasis and was successfully treated by complete surgical removal of the tumor. Conclusion As the diagnosis of paragangliomas is often delayed because of absent clinical symptoms, they represent a significant diagnostic challenge. Although surgery may exacerbate coronavirus disease 2019 infection, surgical resection of this tumor is prioritized, given its malignancy potential, and it must be performed as soon as no infection is detected

Characterization of a novel chitinase from a moderately halophilic bacterium, Virgibacillus marismortui strain M3-23

A new chitinase produced by the moderately halophilic bacterium Virgibacillus marismortui strain M3- 23 was identified and characterized. Distinguishable characteristics of high activity and stability at different pH, temperatures and salinity of M3-23 chitinase are reported. Analysis of the catalytic domain sequence from the enzyme highlighted its relationship to glycosyl hydrolase family 18. Comparison of the deduced chitinase sequence from strain M3-23 to known chitinases from Bacillus species showed low similarity (82%), suggested its novelty. This is the first report of the characterization of chitinase from the species V. marismortui. The halo- and thermo-tolerant nature of the chitinolytic enzyme allows its potential use in agricultural and industrial applications

Estimated lung age in healthy North African adults cannot be predicted using reference equations derived from other populations

Introduction: Interpretation of “lung age” data relies upon comparison of the chronological lung age (CLA) with the estimated lung age (ELA) predicted from published reference equations [7–10]. Aim: To test the applicability of the published reference equations in healthy non-smoker Tunisian aged 19–90 years. Population and methods: Published reference equations were applied to the spirometry results of 540 adults (364 women). Two methods of comparison were applied: (i) Determination, according each equation, of the percentages of subjects having a deltaLungAge (=ELA–CLA) > Upper-Limit-of-Normal (ULN). (ii) Bland and Altman comparison, for the same age range as in the corresponding study, between CLA and ELA. Results: The mean ± SD (95% confidence interval) of the total sample CLA and height were 48.8 ± 13.1 (47.7–49.9) years and 164 ± 10 (163–165) cm. (i) The percentages of healthy subjects with a deltaLungAge > ULN varied from 1% (Newbury) to 64% (Hansen) in men, and from 20% (Yamaguchi) to 51% (Hansen, Morris and Temple) for women. (ii) Mean ± SD ELA was significantly underestimated by 17 ± 19 years (Hansen), by 12 ± 23 years (Morris and Temple) and was significantly overestimated by 4 ± 19 years (Newbury). Mean ± SD ELA from Yamaguchi et al. [10] was not statistically different from the CLA (1 ± 14 years). Conclusion: The published reference equations did not reliably predict CLA data in the Tunisian population. Awaiting the establishment of reliable equation proper to North African population, we recommend the use of the Yamaguchi et al.’s [10] reference equations