Timing matters: diurnal variation of maximal fat oxidation and substrate oxidation rates in metabolic syndrome-a randomized crossover study.

PURPOSE: The aim of this study was to investigate if diurnal oscillation in maximal fat oxidation (MFO) and substrate oxidation rates during exercise exists in subjects with metabolic syndrome (MetS). METHODS: In a randomized crossover design, 14 MetS patients were assigned to two graded exercise tests conditions performed in the morning (between 7:00 and 9:00 a.m) and in the afternoon (between 4:00 and 5:00 p.m). MFO was defined as the highest absolute value of fat oxidation obtained from the average of last 2-min stages during an indirect calorimetry test. RESULTS: MFO increased by 20.6% from morning to afternoon (p = 0.0002, Cohen's d = 0.52). There was a significant time of day, (p < 0.0001, η2p = 0.76) and intensity effect (p = 0.002, η2p = 0.32) in fat oxidation (Fatox) rates indicating that Fatox was higher in the afternoon than in the morning. CONCLUSION: Our study extends previous findings on the existence of diurnal variation in maximal fat oxidation to MetS patients, highlighting the afternoon as a more favorable time for fat utilization during exercise. These findings have practical implications for optimizing training timing in MetS patients. TRIAL REGISTRATION NUMBER: PACTR202306776991260.

The Effects of Aging on Exhaled Nitric Oxide (FeNO) in a North African Population.

OBJECTIVE: To determine and explain the effect of age on exhaled nitric oxide values in North African healthy subjects aged from 5 to 83 years. DESIGN: Prospective cross-sectional study. METHODS: Volunteer children adults and elderly healthy subjects were included. A medical questionnaire was used to assess several subject characteristics. The levels of exhaled fraction of nitric oxide (FeNO) were measured by Medisoft HypAir FeNO method. Spirometry function test was done after the FeNO measurement. The following parameters were measured: forced vital capacity (FVC, L); 1st second forced expiratory volume (FEV1, L); FEV1/FVC ratio (absolute value); maximal mid expiratory flow (MMEF, L/s); Mid expiratory flow from 25 to 75% (MEF25%, MEF50%, and MEF75%). Statistical analyses were carried out using Statistica software with a significance set at the 0.05 level. RESULTS: A significant increase in FeNO is noted between groups with respective age ranges of (5, 17) and (17, 25) years with a breakpoint at 1,397,034 years. A significant decrease of FeNO is noted between groups with respective age ranges of (45, 55) and (55, 65) years with a breakpoint at 6,366,052 years. No statistical significant difference was found between females' and males' means FeNO data. Finally, SEL, obesity status, and hypertension contribute significantly in the variations of FeNO values. CONCLUSION: The development and aging of the lung touched non-respiratory functions and so modified FeNO values in healthy North African subjects.

Cortisol cut-points for the glucagon stimulation test in the evaluation of hypothalamic pituitary adrenal axis.

Diagnosis of adrenal insufficiency requires evaluation by dynamic stimulation tests. The insulin tolerance test (ITT) is accepted as the gold-standard test for the evaluation of hypothalamo-pituitary-adrenal (HPA) axis but the test is unpleasant and dangerous. Although it takes more time, glucagon stimulation test (GST) is a good alternative to ITT. The primary aim of this study was to compare the ITT and GSTs in the evaluation of HPA axe in patients with pituitary disorders. We conducted a prospective study in which ITT and GST were performed within 7 days in 81 patients. Serum cortisol was measured. We divided our population in Group 1 (G1): Adrenal Insufficiency (Peak cortisol under ITT <200 ng/mL) and Group 2 (G2): normal response (Peak cortisol under ITT >200 ng/mL). Receiver-operating characteristic (ROC) analysis was performed to identify the thresholds for GST. The mean peak of cortisol under GST was not significantly different from that obtained after ITT in the whole cohort (182.67 ± 89.07 ng/mL vs. 179.75 ± 79.01 ng/mL), and it was significantly reduced in patients of G1 (p < 10-3). ROC curve analysis showed that the best diagnostic accuracy was obtained with a peak cortisol cut-off to GST of 167 ng/mL (sensitivity, 89%; specificity, 79%). Using this cut-off, 86.4% of the patients were correctly classified. In our prospective series, GST is a potential accurate and safe alternative test for the assessment HPA. Test-specific cut-offs should be applied to avoid misinterpretation.

Effect of ultrasonic degradation of hyaluronic acid extracted from rooster comb on antioxidant and antiglycation activities.

CONTENT: Recently, low-molecular-weight hyaluronic acid (LMWHA) has been reported to have novel features, such as free radical scavenging activities, antioxidant activities and dietary supplements. OBJECTIVE: In this study, hyaluronic acid (HA) was extracted from rooster comb and LMWHA was obtained by ultrasonic degradation in order to assess their antioxidant and antiglycation activities. MATERIALS AND METHODS: Molecular weight (Mw) and the content of glucuronic acid (GlcA) were used as the index for comparison of the effect of ultrasonic treatment. The effects on the structure were determined by ultraviolet (UV) spectra and Fourier transform infrared spectra (FTIR). The antioxidant activity was determined by three analytical assays (DPPH, NO and TBARS), and the inhibitory effect against glycated-BSA was also assessed. RESULTS: The GlcA content of HA and LMWHA was estimated at about 48.6% and 47.3%, respectively. The results demonstrate that ultrasonic irradiation decreases the Mw (1090-181 kDa) and intrinsic viscosity (1550-473 mL/g), which indicate the cleavage of the glycosidic bonds. The FTIR and UV spectra did not significantly change before and after degradation. The IC50 value of HA and LWMHA was 1.43, 0.76 and 0.36 mg/mL and 1.20, 0.89 and 0.17 mg/mL toward DPPH, NO and TBARS, respectively. Likewise LMWHA exhibited significant inhibitory effects on the AGEs formation than HA. DISCUSSION AND CONCLUSION: The results demonstrated that the ultrasonic irradiation did not damage and change the chemical structure of HA after degradation; furthermore, decreasing Mw and viscosity of LMWHA after degradation may enhance the antioxidant and antiglycation activity.

6-min walk-distance norms in adults Arab populations: a literature review.

INTRODUCTION: The primary outcome of the 6-min walk-test is the 6-min walk-distance (6MWD). Its interpretation relies upon the comparison of the measured 6MWD with the predicted one from published norms. OBJECTIVE: The aim of the present review is to report the 6MWD norms published for healthy adults Arab populations. METHODS: The review includes a literature search, from 1970 to January 5th 2017 using the PubMed search engine. Reference equations lists of retrieved English/French articles were searched for any supplementary references. The research includes the combination of the following (or their synonyms) "Medical Subject Headings" or "Title/Abstract" terms: «walking¼ AND «reference values¼ AND «Arabs¼. RESULTS: Five studies, conducted in Saudi-Arabia (n=2), Tunisia (n=2) and Algeria (n=1) were included. Norms comprised the following factors: age (Yrs), height (cm), weight (kg), body mass index (BMI, kg/m2), sex (0:women; 1:men) and physical activity level. Five norms were proposed for Tunisian aged 40-79 years [6MWD (m) = 299.8 - 4.34xAge + 3.43xHeight - 1.46xWeight + 62.5xSex] or aged 40-85 years [6MWD (m) = 720.50 + 160.27xSex - 5.14xAge - 2.23xWeight + 2.72xHeight], for Saudi-Arabian aged 16-50 years [6MWD (m) = - 28.5 + 2.81xHeight + 0.79xAge] or aged 18-71 years [6MWD (m) = 342.650 + 74.31xPhysical activity level + 33.88xSex - 4.25xAge] and for Algerian aged 16-40 years [6MWD (m) = 800.05 + 64.71xSex - 10.23xBMI - 1.63xAge + 2.05xWeight]. These norms explained 25% to 77% of the 6MWD variability. CONCLUSION: Fewer 6MWD norms exist for adults' Arab population. Other norms are welcome.

Oral health effects associated with narghile use.

Background - As dentists are certain to encounter narghile-smokers amongst their patients, it is important to inform them of the possible detrimental impacts of narghile-use on oral-health. Objective - To review the literature on the oral-health effects of narghile-use. Methods - Data Sources - We made a search on pubmed until June 30th, 2015 for the chronic oral-health effects of narghile-use using the terms "oral-lesions" or "oral-cancer" or "dry-socket" or "periodontium" and 'narghile' or its different synonyms. Study selection - Only original studies and case reports or series focusing on clinical human studies were included. Sixteen studies met the selection criteria and 14 were retained. Data extraction - Data were abstracted by two authors and summarized into tables. Abstracted data, including study type and results, were analyzed jointly by four authors. Results - Data synthesis. Narghile-use has harmful effects on oral-cavity including periodontal diseases, dry-sockets and oral-mucosa lesions. Conclusion - Narghile-use is associated with a variety of adverse long-term oral-health effects that should reinforce the need for stronger regulation. Key-words - Tobacco - Oral lesions - Oral cancer - Periodontium - Dry-socket.

Influencing factors of the 6-min walk distance in adult Arab populations: a literature review.

Background Walk tests, especially the 6-min walk-test (6MWT), are commonly used in order to evaluate submaximal exercise capacity. The primary outcome of the 6MWT is the 6-min walk-distance (6MWD). Numerous demographic, physiological and anthropometric factors can influence the 6MWD in healthy adults. Objective The purpose of the present review is to highlight and discuss the 6MWD influencing factors in healthy of the healthy adult Arab populations. Methods It is a review including a literature search, from 1970 to September 31th 2015 using the PubMed, the Science Direct databases and the World Wide Web on Google search engine. Reference lists of retrieved English/French articles were searched for any additional references. Results Six studies, conducted in Tunisia (n=2), Saudi Arabia (n=3) and Algeria (n=1) were included. All studies were conducted according to the 2002-American-thoracic-society guidelines for the 6MWT. In addition to anthropometric data (sex, age, height, weight, body mass index, lean mass), the following data were recognized as 6MWD influencing factors: schooling and socioeconomic levels, urban origin, parity, physical activity score or status, metabolic equivalent task for moderate activity, spirometric data, end-walk heart-rate, resting diastolic blood pressure, dyspnoea Borg value and niqab-wearing. Conclusion The 6MWD influencing factors in adult Arab populations are numerous and include some specific predictors such as parity, physical activity level and niqab-wearing.

Fraction of exhaled nitric oxide in healthy elderly Tunisian subjects.

INTRODUCTION: Exhaled-fraction-of-nitric-oxide (FeNO) norms are absent in healthy elderly North-African subjects. OBJECTIVES: i) to identify FeNO influencing factors of elderly Tunisians older 50 years and more; ii) to assess the applicability of some published FeNO norms for elderly in local population; iii) to set-up FeNO norms and to prospectively evaluate their validity in two elderly validation-groups (healthy and asthmatic subjects). METHODS: A convenience sample of healthy and asthmatic elderly Tunisians was recruited. Subjects responded to a medical questionnaire and then FeNO levels were measured by an online method (Medisoft, Sorinnes (Dinant), Belgium). Clinical, anthropometric and spirometric data were collected. Three groups of subjects were identified: group I (healthy-elderly; n = 100, 57 females); group II (healthy-validation; n = 17, 4 females) and group III (asthmatic-validation; n = 10, 9 females). ANOVA was performed to compare the three groups' data. RESULTS: No significant factor, among those evaluated, influenced Tunisian elderly FeNO values. The available published FeNO norms did not reliably predict FeNO in Tunisian elderly population. The mean ± SD (minimum-maximum) of FeNO (ppb) for group I was 14 ± 6 (3-34). For Tunisian people, each elderly FeNO value higher than 34 ppb will be considered as abnormal. There was no statistical significant difference between FeNO (ppb) mean values of group I and groups II (15 ± 8) or III (18 ± 13). No subject of group II had a FeNO value higher than 34 ppb. Thirty percent of group III subjects had a FeNO value higher than 34 ppb. CONCLUSION: In practice, FeNO value of more than 34 ppb is considered abnormal in elderly Tunisian population.

[Women smoking in the Tunisian center: socio demographic characteristics and effects on functional respiratory parameters]. / La tabagisme au feminin au centre Tunisien : Caractéristiques sociodémographiques et retentissement fonctionnel respiratoire.

UNLABELLED: Objectives of this study were to describe sociodemographic characteristics of Tunisian woman smoker and to study her respiratory functional profile. METHODS: all women answered for a questionnaire and benefited of a total physical plethysmography and of a carbon monoxide lung transfer measure (TLCO). RESULTS: 101 smoking women were selected. These women consumed cigarettes (74 %), the snuff "neffa "(10 %) and the water pipe (15 %). A chronic bronchitis was present at 22 women. A proximal bronchial obstruction was found at 11 women who were consumer of the "neffa" and cigarettes. A lower airway obstruction was found in all women consumer of water pipe. The TLCO was low at "neffa" group of women. CONCLUSION: woman smoking has a negative influence on pulmonary function which depends on sociocultural characteristics and on the history of smoking.

[Early detection of COPD in smoking cessation outpatients]. / Détection précoce de la BPCO dans les consultations d'aide au sevrage tabagique.

BACKGROUND: Chronic Obstructive Pulmonary Disease (COPD) is among the leading causes of chronic morbidity and mortality throughout the world. Potentially, COPD can be prevented by the early detection of COPD, which generally entails spirometry. Physicians in smoking cessation outpatient are in an ideal position to detect early-stage of COPD by the simple examination of the patient. They can also perform spirometry to confirm the diagnosis of COPD. The main objective of this study was to assess the frequency of COPD among smokers in smoking cessation outpatient. Secondary objectives were to Compare two methods for COPD screening, the questionnaire (clinical score) and the mini-electronic spirometer (Neo-6) and to assess the degree of motivation to stop smoking by the announcement of lung age to smokers. METHODS: a prospective cross-sectional study was carried out in four consultations for smoking cessation. Inclusion criteria were male patients aged over 35 years and seen in smoking cessation outpatient. A clinical score was then calculated to detect COPD. This score is based on age, BMI, the quantity of tobacco smoking and the respiratory clinical signs. By establishing this score, we could classify our smokers on consultants with likely COPD if the clinical score>16. Secondly, a measure of the breath with a portable minispirometre "neo6" was performed with quantification of the first second forced expiratory volume (FEV1), forced expiratory volume in 6 seconds (FEV6) and their ratio (FEV1/FEV6). A ratio FEV1/FEV6 less than 0.8 was in favor of an obstructive ventilator defect (DVO). In this case a total body plethysmography was indicated. RESULTS: The sample of the study consisted of 115 male smokers with a mean age of 48±12 years old. A low socio-economic level and a low level of education were found respectively in 50.4% and 58% of smokers. Cigarette smoking is the most consumed form of tobacco. A significant clinical score predicting COPD, was found in 54 patients. The measurement of the breath through the Neo-6 found that 23 (20%) smokers had FEV1/FEV6 less than or equal to 0.7 predicting bronchial obstruction and 26 had a ratio between 0.7 and 0.8. plethysmography confirmed the diagnosis of COPD for 27 patients. So the prevalence of COPD in our sample was of 23.48%. The clinical score had a sensibility of 81.48% and a specificity of 63.64 with a negative predictive value of 91.8%. The sensitivity of the Neo 6 (70.37%) is smaller than the clinical score but the specificity is better than 95.94 % of the clinical score. Its negative predictive value was 91.3%. So when VEMS/VEM6 ratio is greater than 0.7, the probability of COPD remains very low. The announcement of the pulmonary patient age is an important parameter for the motivation to stop smoking. CONCLUSION: The combination of a standardized questionnaire to the measure of breath by Neo6 can further optimize COPD screening.

First description of French V. tubiashii strains pathogenic to mollusk: II. Characterization of properties of the proteolytic fraction of extracellular products.

Extracellular products (ECPs) of the French Vibrio tubiashii strain 07/118 T2 were previously reported to be toxic for the Pacific oyster Crassostrea gigas. In this study we now assessed host cellular immune responses and bacterial potential effectors by which these ECPs can be associated with host damages. The adhesion capacity (28% inhibition) and phagocytosis ability (56% inhibition) of oyster hemocytes were the main functions affected following in vitro contact between hemocytes and V. tubiashii ECPs. This may be linked to the demonstration of the capability of ECPs to cleave various cellular substrates as oyster collagen. Moreover, a strong metalloproteolytic activity was recorded with general (azocasein) and specific (ADAM) substrates and characterized by the use of standard inhibitors and metal ions. The addition of 1,10-phenanthroline and Zn2+ decreased proteolytic activity by about 80% and 50% respectively, confirming the presence of zinc metalloproteolytic activity in the ECPs. Mass spectrometry analyses of crude ECPs identified an extracellular zinc metalloprotease encoded by a gene with an open reading frame of 1821 bp (606 aa). Consensus zinc-binding motifs specific to thermolysin family and some glycosylation and phosphorylation sites were located on the deduced protein sequence. Taken together, our results suggest that this (these) zinc metalloprotease(s) might contribute to the impairment of hemocyte immunological functions; however, their direct involvement in ECPs toxicity remains to be demonstrated.

[The diagnosis of COPD is recommendation dependent]. / Le diagnostic positif de la BPCO est recommendation dépendant.

BACKGROUND: Different spirometric criteria are recommended to diagnosis chronic obstructive pulmonary disease (COPD): -American Thoracic Society/European Respiratory Society (ATS/ERS), Global initiative for chronic Obstructive Lung Disease (GOLD): a post bronchodilator (PBD) ratio between the 1st second Forced Expiratory Volume and Forced Vital Capacity (FEV1/FVC) < 0.70; -Thoracic Society of Australia and New Zealand (ANZTS): a PBD FEV1/FVC < 0.70 and a PBD FEV1 < 80%; -British Thoracic Society (BTS): a before BD (BBD) FEV1/FVC < 0.70 and a BBD FEV1 < 80%; -Old criterion retained, till 2010, by the French Society of Pneumology (SPLF): a PBD ratio between FEV1 and slow vital capacity < 0.70. AIM: To determine, according to the different recommendations, the percentage of smokers having COPD among a population of smokers of more than 40 Packets/Year (PY) addressed for plethysmography. METHODS: The plethysmographic data of 531 consecutive stable male smokers that underwent reversibility testing (400 µg of Salbutamol®) were analyzed. RESULTS: The mean ± SD of age, cigarettes consumption, PBD FEV1 (%), were, respectively, 61 ± 11 Yr, 64 ± 20 PY and 52 ± 21%. The percentages of subjects having COPD according to the above criteria were 75.5% (SPLF old criterion); 71.2% (ATS/ERS, GOLD); 70.8% (BTS) and 69.7% (ANZTS). CONCLUSION: The diagnosis of COPD depends on which guidelines are used for defining the disease. This forms a barrier to early diagnosis, affects public health decisions and wrong planning strategies.

Applicability of the Old European Respiratory Society/European Community for Steel and Coal reference equations for spirometry interpretation in Tunisian adult population.

BACKGROUND: Tunisian pulmonary functional laboratories accept the default settings for reference equations (European Respiratory Society/European Community for Steel and Coal (ERS/ECSC1983) offered by the manufacturer even though adult Tunisian reference equations (Tunisian1995) are available. OBJECTIVE: To compare the spirometric profile of Tunisian subjects, according to the two reference equations. POPULATION AND METHODS: Spirometric data were recorded from 1192 consecutive spirometry procedures in adults aged 18-60 years. Reference values and lower limits of normality (LLN) were calculated using the two reference equations. Applied definitions: large airway obstructive ventilatory defect (LAOVD): ratio between the 1st second expiratory volume and forced vital capacity (FEV1/FVC) < LLN. Small AOVD (SAOVD): FEV1/FVC > LLN and FVC > LLN and maximal midexpiratory flow < LLN. Tendency through a restrictive ventilatory defect (TRVD): FEV1 and FVC < LLN. The spirometric profile, according the two reference equations, was determined. RESULTS: Using Tunisian1995 reference equations, 34%, 7%, 37% and 19% of spirometry records were interpreted as normal, and as having, LAOVD, SAOVD and TRVD, respectively. Using ERS/ECSC1983 reference equations, 85%, 3%, 9% and 2% of spirometry records were interpreted as normal, and as having, LAOVD, SAOVD and TRVD, respectively. Using the ERS/ECSC1983 reference equations, misclassification was worse for LAOVD, for SAOVD and for TRVD, respectively, 68%, 94% and 89%. CONCLUSION: Our results showed that the use of the old Caucasian reference equations resulted in misinterpretation of spirometry data in a significant proportion of subjects. This could result in inappropriate diagnosis and/or management.

Effect of diabetes self-management education on health-related quality of life of Tunisian children with type1 diabetes mellitus and their parents: A randomized controlled trial.

AIM: To assess the effect of diabetes self-management education (DSME) on health related quality of life (HRQoL) of Tunisian children/adolescents with type 1 diabetes mellitus and their parents. METHODS: This monocentral study used a randomized controlled trial design, during five-month intervention and five-month follow-up and including 110 patients (54 in the DSME intervention group and 56 in the Individual Education by Pediatrician (IEP) control group) and their parents. Pediatric Generic Core Quality-of-Life Inventory 4.0-Scale (PedsQL4.0) evaluated HRQoL. RESULTS: At baseline, both groups had similar clinical features and PedsQL4.0 scores (p>0.05). In DSME, clinical outcomes were significantly improved from baseline to follow-up (p<0.001), while in the IEP group, which received no intervention, these outcomes remained unchanged. During follow-up, DSME showed higher PedsQL4.0 scores in parents' proxy-report and children/adolescents self-report (p<0.001). According to parents' proxy-report, PedsQL4.0 scores were significantly higher during follow-up compared to baseline in DSME (p<0.001) while they remained the same in IEP (p>0.05). DSME had higher percentage of change in the PedsQL4.0 scores than IEP (p<0.01). The median change varied from -5.01% to 0% vs 5.41% to 36.36% in IEP and DSME, respectively. CONCLUSION: Encouraging healthcare professionals to incorporate these interventions could enhance the HRQoL of diabetic children and bolster their self-esteem.

[The announcement of the lung age it is a motivation to quit smoking?]. / L'annonce de l'âge pulmonaire aux fumeurs est-elle une motivation au sevrage tabagique?

BACKGROUND: Smoking represents an ever-increasing problem of public health in the world, the impact of which is actually rising. The majority of smokers wish to stop smoking one day. This fact is one of the major acts leading to a better health and wellbeing. In the eighties, the lung age was already mentioned by Morris and Temple, a further tool motivating tobacco cessation. AIM: To determine the lung age of a population of workers and to evaluate the impact of its announcement on the smoking behavior. METHODS: It is a prospective study realized during a year (November 2010-November 2011) in a wire enterprise LEONI in Sousse (Tunisia), during an intervention program. 35 adult smokers were concerned by our study. A measurement of the breathing function by "Néo6" and a calculation of the lung age were practiced on all smokers. RESULTS: 35 smoking men (mean ± SD age of 36 ± 7 years, 27 and 28 smokers have, respectively, a high socio-economic level and a high schooling level) were included. The number of daily cigarettes consumed was from 5 to 40. The measurement of the smokers' respiratory function by the "Neo 6" did not show a pulmonary function defect. The lung age was of 45 ±13 years, significantly higher than the chronological age. The evaluation of the announcement of the lung age, realized one year after, showed that 8 among the 35 workers have stopped smoking and 7 smokers have reduced their tobacco consumption. CONCLUSION: Communicating the lung age results is an additional tool motivating tobacco cessation.

How to interpret parameters of routine lung function tests in 2023?

The diagnosis and management of the most prevalent chronic respiratory diseases partially rely on parameters obtained from pulmonary functional tests (PFTs), including spirometry, plethysmography, and carbon monoxide diffusion capacity (DLCO) measurement. In practice, the interpretation of PFTs' parameters is based on international recommendations issued by renowned scientific societies such as the American Thoracic Society (ATS) and the European Respiratory Society (ERS). The interpretation standards for PFTs established by ATS/ERS in 2005 were updated in 2022. According to the ATS/ERS-2022 standards, the interpretation of PFTs can be summarized in five steps. The first step involves comparing the determined parameters with those observed in a reference population of healthy individuals. This step helps determine whether the determined parameters are low, normal, or elevated. The second step aims to identify potential ventilatory impairments, such as obstructive and/or restrictive ventilatory impairments, which can be observed in certain chronic respiratory or extrarespiratory diseases. The third step involves assessing the severity of the identified ventilatory impairment or the decrease in DLCO. The fourth step entails evaluating the response to bronchodilator testing, if performed. Finally, if previous PFTs results are available, it is important to identify significant changes in certain PFTs parameters over time by comparing current and previous results. This clinical practice guide provides a comprehensive synthesis of the different steps in PFTs interpretation, taking into account the recommendations from ATS/ERS-2022.

Spirometric reference values for children living in Constantine (Eastern region of Algeria).

BACKGROUND: Spirometry play an important role in diagnosing obstructive lung disease, assessing the severity of lung disease, monitoring treatment of patients with respiratory disorders, and allocating patients to treatment groups in drug intervention studies. Since spirometric lung function depends on body size, age, gender and ethnic group, reference equations derived from healthy individuals are imperative for interpreting results. AIM: To assess the need for spirometric norms for children 5 to 16 years old and living in Constantine (Eastern region of Algeria). METHODS: Anthropometric and spirometric data were measured in 208 healthy children (101 girls) living in Constantine (649 m above sea level). RESULTS: Published reference equations did not reliably predict measured spirometric data in Constantinian children. Combination of gender, age, height, weight, body mass index and body surface area explained between 69% and 94% of the spirometric data variability's. FEV1/FVC ratio [means±SD (5th percentiles) were0.91±0.06 (0.80) for boys and 0.90±0.06 (0.81) for girls] was not included in the regression because of its relative independence of anthropometric data. The mean±SD of the forced expiratory time was 2.44±0.74 s and only 27% of children reached the threshold of ³ 3 s. In an additional group of 24 children prospectively studied, the agreement between measured and predicted FEV1 was satisfactory. CONCLUSION: Our reliable spirometric reference equations provide a useful norm for the care of paediatric patients living in the Eastern region of Algeria. The present study enriches the World Bank of reference equations, from which physicians should choose according to where patients live and their ethnic background.

Aging, tobacco use and lung damages.

The main two functions of the lung are the respiratory functions, dependent on ventilatory mechanics and gas exchange, and the nonrespiratory functions such as metabolic, immunological, and endocrine ones. Lung aging is secondary to the age-dependent impairment of one or more of these functions. Tobacco use accelerates lung aging and touches biological, structural and respiratory and non-respiratory functions. These changes contribute to the development of chronic pulmonary diseases and predispose to pulmonary infections in older individuals. The knowledge of these changes is very useful for better management of elderly. Lung health in aging can be improved by strategies that slow the age-related decline in lung function by acting on the environmental parameters. It is also possible to improve lung development in children and to strengthen the lungs' resistance to environmental challenges and thus to extrinsic lung aging.

The aging lung face to COVID-19.

Coronavirus disease 2019 (COVID-19) has so far killed many people; with the majority of deaths occurring in people over the age of 65 years. It has been noted that the severity and outcome of COVID-19 depends in part on the patient's age. The combination of three factors could explain this ascertainment: the first is linked the lung aging, the second is the associated comorbidities in elderly subjects and the third is the particularities of COVID-19. Here we emphasize the modifications linked to pulmonary aging and their role in worsening the COVID-19 disease.

Chemical characteristics and cancer risk assessment of smokeless tobacco used in Tunisia (neffa).

INTRODUCTION: neffa, a form of air-dried smokeless tobacco used in North Africa, is spuriously perceived as a lower risk alternative to smoking. The objective of this study was to provide information on some harmful constituents of neffa and to use them for cancer risk assessment. METHODS: a high-performance liquid chromatography method coupled with fluorescence detector was used to determine polycyclic aromatic hydrocarbons (PAHs) in one sample of neffa. An atomic absorption spectrometry was performed to determine the concentrations of lead and cadmium in three samples of neffa. The levels of toxicants found in neffa were used to assess for lifetime cancer risk as advocated by the US Environment Protection Agency. RESULTS: the determination of PAHs in neffa allowed the identification of phenanthrene and anthracene. However, the higher molecular weight PAHs such as Benzo(a)Pyrene B(a)P were not detected. The concentrations of cadmium and lead varied between 1.3 to 2.8µg/g and 1.7 to 4.6µg/g respectively. Cancer risk for cadmium and lead varied between 4.2E-03 to 9.3E-03 and 2.5E-06 to 6.4E-06 respectively. Cancer risk for Cd exceeded the range of 10E-04 to 10E-06 of an acceptable risk. CONCLUSION: neffa is not a healthy alternative for overcoming smoking addiction. It contains mineral and organic pulmonary toxicants. This study could serve as a scientific basis to inform consumers about the products´ toxicity and help them to quit smokeless tobacco (SLT) use.