Chemical composition, antioxidant effects and antimicrobial activities of some spices’ essential oils on food pathogenic bacteria

Thymus vulgaris, Cinnamomum zeylanicum and Ocimum gratissimum are spices widely used as aroma enhancers and food preservatives. This work assessed the chemical composition, antioxidant and antimicrobial effect of their essential oils on some food pathogenic bacteria, namely, Staphylococcus aureus, Citrobacter freundii, Enterobacter cloacae, Morganella morganii, Escherichia coli, Salmonella typhimurium, Proteus vulgaris and Shigella flexineri. After chemical analyses of the essential oils by gas chromatography and gas chromatography coupled to mass spectroscopy, the antimicrobial effects were subsequently assessed by disk and microdilution methods, while the antioxidant evaluations were performed by free radical scavenging activity. T. vulgaris essential oil composed of p-cymene (45.90%) and thymol (23.72%) which exhibited the highest inhibitory diameters of 20.33±0.58 and 18.00±1 mm, respectively, on the growth of S. aureus and C. freundii. O. gratissimum essential oil with thymol as major compound (47.11%) was more active to inhibit the growth of C. freundii and S. flexineri with respective inhibitory diameters of 18±1.73 and 16±2 mm. Essential oil from dry leaves of C. zeylanicum containing cinnamaldehyde (82.23%) and linalool (12.12%) was found to have the lowest values for minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) (≤3.53 mg/mL)considering the growth of S. flexineri, C. freundii and E. cloacae. Regarding the antioxidant effect, C. zeylanicum and T. vulgaris essential oil showed the most scavenging effect with half-maximal DPPH scavenging concentration (SC50) of 2.5 × 10-5 and 6.5 × 10-5 mg/ml, respectively. Their antioxidant effects were higher than conventionally used antioxidants in food products, butylhydroxyltoluene (BHT) and vitamin C.Key words: Spices, essential oils, chemical composition, antibacterial and antioxidant effects

Relationship between oral health and Fried's frailty criteria in community-dwelling older persons.

Oral health and frailty might be linked through several pathways, but previous studies are scarce. This study examined the association between oral health and components of Fried's frailty phenotype. This cross-sectional analysis was based on a sample of 992 community-dwelling persons aged 73 to 77 years observed in the 2011 follow-up of the Lausanne 65+ cohort (Lc65+) study. Data were collected through annual mailed questionnaires, interview and physical examination. Oral health was assessed according to self-reported oral pain and masticatory ability. Frailty was defined as meeting at least one criterion of the Fried's phenotype. Oral pain was reported by 14.8% and chewing problems by 9.7%. Impaired masticatory ability (IMA) was more frequent in subjects with missing teeth or removable dentures (13.5%) than among those with full dentition or fixed dental prostheses (3.2%). In logistic regression analyses adjusting for demographics, alcohol consumption, smoking, comorbidity and financial difficulties, persons with oral pain and those with chewing problems had significantly higher odds of being frail (adjusted OR javax.xml.bind.JAXBElement@4700992c  = 1.72; 95% CI 1.17-2.53 and adjOR javax.xml.bind.JAXBElement@a67b3e3 1.70; 1.07-2.72, respectively). Lack of endurance was associated with both oral pain (adjOR = 3.61; 1.92-6.76) and impaired masticatory ability (adjOR = 2.20; 1.03-4.72). The latter was additionally linked to low physical activity (adjOR = 2.35; 1.29-4.28) and low gait speed (adjOR = 3.12; 1.41-6.90), whereas oral pain was associated with weight loss (adjOR = 1.80; 1.09-2.96) and low handgrip strength (adjOR = 1.80; 1.17-2.77). Self-reported oral pain and chewing impairment had a significant relation with frailty and its components, not only through a nutritional pathway of involuntary weight loss. Longitudinal analyses are needed to examine whether a poor oral condition might be a risk factor for the onset of frailty

Gender disparities in pulmonary hypertension at a tertiary centre in Cameroon

Background. Pulmonary hypertension (PH) is a potent cause of heart failure and has been little investigated in the African setting. Objective. To investigate the effects of gender on the clinical presentation, echocardiographic features and outcomes of patients with PH in Douala, Cameroon. Methods. A prospective cohort study was conducted from March 2012 to December 2013 as part of the Pan African Pulmonary Hypertension Cohort study. PH was diagnosed by echocardiography and defined as a right ventricular systolic pressure >35 mmHg in the absence of acute right heart failure. Patients were followed up for a maximum of 12 months for primary endpoint mortality. Results. In total, 130 patients with PH were recruited; 71 (54.6%) were women. The median age was 59.2 years for men and 58.3 years for women (p=0.76). Active smoking and alcohol use were more frequent in men than women (both p<0.001), but women had greater exposure to indoor cooking fumes than men (p<0.001). Previous tuberculosis infection (11.3% v. 1.7%) and S3 gallop rhythm (30.9% v. 11.9%) were more common in women (both p<0.03). Women had a significantly higher mean systolic blood pressure (134 mmHg v. 125 mmHg; p=0.04) and pulse pressure (53.8 mmHg v. 44.9 mmHg; p=0.01) and a lower mean haemoglobin concentration (10.4 g/dL v. 12.4 g/dL; p<0.05) compared with men. Echocardiographic left ventricular (LV) systolic dysfunction was more frequent in men: mean LV ejection fraction 42.6% v. 51.5% (p=0.01) and mean fractional shortening 21.4% v. 28.6% (p=0.01). The overall mortality rate was 20.3%, and rates were similar in the two groups (Kaplan-Meier log rank 1.1; p=0.30). Conclusions. Despite differences in baseline characteristics including cardiovascular risk factors, mortality rates on follow-up were similar in men and women in this study. However, these different baseline characteristics probably suggest differences in the pathogenesis of PH in men and women in our setting that need further investigation.S Afr Med J 2017;107(10):892-89

Plasma Letrozole Concentrations in Postmenopausal Women With Breast Cancer Are Associated With CYP2A6 Genetic Variants, Body Mass Index, and Age

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109858/1/cptclpt2011174.pd

Surface properties of distinct nanofibrillated celluloses assessed by inverse gas chromatography

The adhesion and surface properties of nanocelluloses are an important issue to consider when using this material for composites production, in food packaging or coatings, as well as for determining the influence of added functional groups. In the present work, the surface properties of two nanofibrillated celluloses obtained by mild 2,2,6,6-tetramethylpiperidine-1- oxyl radical (TEMPO)-mediated oxidation with distinct mechanical treatment intensity in a homogenizer (5 and 15 passes), and one nanofibrillated cellulose obtained by enzymatic process, were thoroughly assessed by inverse chromatography, at infinite dilution conditions. The dispersion component of the surface energy ( s d) was 42-46 mJ m-2 at 40 ºC for the TEMPO nanofibres and 52 mJ m-2 for the enzymatic nanocellulose. It was confirmed, based on the determination of the specific components of the works of adhesion and enthalpies of adsorption with polar probes, that the surfaces of the materials have a more Lewis acidic than Lewis basic character. Regarding TEMPO nanofibres, a slight increase of Lewis acidity/basicity ratio seemed to occur for the more nanofibrillated material (15-passes). Higher specific interactions with polar probes were found for enzymatic nanocellulose. The higher values of s d and specific interactions observed for the enzymatic nanocellulose could partly be due to the higher crystallinity of this sample. On the other hand, the increase of the acidity/basicity ratio (as well as of the s d value) for the 15-passes vs. 5-passes TEMPO nanofibres was attributed to a higher exposition of the hydroxyl groups of cellulose at the surface of the former material

Fine-scale mapping of Schistosoma mansoni infections and infection intensities in sub-districts of Makenene in the Centre region of Cameroon

BackgroundSchistosomiasis control relies mainly on mass drug administration of Praziquantel (PZQ) to school aged children (SAC). Although precision mapping has recently guided decision making, the sub-districts and the epidemiological differences existing between bio-ecological settings in which infected children come from were not taken into consideration. This study was designed to fill this gap by using POC-CCA and KK to comparatively determine the prevalence and infection intensities of Schistosoma mansoni (S. mansoni) and to perform fine-scale mapping of S. mansoni infections and its infection intensities with the overarching goal of identifying sub-districts presenting high transmission risk where control operations must be boosted to achieve schistosomiasis elimination.MethodologyDuring a cross- sectional study conducted in Makenene, 1773 stool and 2253 urine samples were collected from SAC of ten primary schools. S. mansoni infections were identified using the point of care circulating cathodic antigen (POC-CCA) and Kato-Katz (KK) test respectively on urine and stool samples. Geographical coordinates of houses of infected SAC were recorded using a global position system device. Schistosome infections and infection intensities were map using QGIS software.ResultsThe prevalence of S. mansoni inferred from POC-CCA and KK were 51.3% and 7.3% respectively. Most infected SAC and those bearing heavy infections intensities were clustered in sub-districts of Baloua, Mock-sud and Carriere. Houses with heavily-infected SAC were close to risky biotopes.ConclusionThis study confirms the low sensitivity of KK test compared to POC-CCA to accurately identify children with schistosome infection and bearing different schistosome burden. Fine-scale mapping of schistosome infections and infection intensities enabled to identify high transmission sub-districts where control measures must be boosted to reach schistosomiasis elimination.Host-parasite interactio

Gender disparities in pulmonary hypertension at a tertiary centre in Cameroon

Background. Pulmonary hypertension (PH) is a potent cause of heart failure and has been little investigated in the African setting.Objective. To investigate the effects of gender on the clinical presentation, echocardiographic features and outcomes of patients with PH in Douala, Cameroon.Methods. A prospective cohort study was conducted from March 2012 to December 2013 as part of the Pan African Pulmonary Hypertension Cohort study. PH was diagnosed by echocardiography and defined as a right ventricular systolic pressure >35 mmHg in the absence of acute right heart failure. Patients were followed up for a maximum of 12 months for primary endpoint mortality.Results. In total, 130 patients with PH were recruited; 71 (54.6%) were women. The median age was 59.2 years for men and 58.3 years for women (p=0.76). Active smoking and alcohol use were more frequent in men than women (both p<0.001), but women had greater exposure to indoor cooking fumes than men (p<0.001). Previous tuberculosis infection (11.3% v. 1.7%) and S3 gallop rhythm (30.9% v. 11.9%) were more common in women (both p<0.03). Women had a significantly higher mean systolic blood pressure (134 mmHg v. 125 mmHg; p=0.04) and pulse pressure (53.8 mmHg v. 44.9 mmHg; p=0.01) and a lower mean haemoglobin concentration (10.4 g/dL v. 12.4 g/dL; p<0.05) compared with men. Echocardiographic left ventricular (LV) systolic dysfunction was more frequent in men: mean LV ejection fraction 42.6% v. 51.5% (p=0.01) and mean fractional shortening 21.4% v. 28.6% (p=0.01). The overall mortality rate was 20.3%, and rates were similar in the two groups (Kaplan-Meier log rank 1.1; p=0.30).Conclusions. Despite differences in baseline characteristics including cardiovascular risk factors, mortality rates on follow-up were similar in men and women in this study. However, these different baseline characteristics probably suggest differences in the pathogenesis of PH in men and women in our setting that need further investigation.

Closing a gap in tropical forest biomass estimation : taking crown mass variation into account in pantropical allometries

Accurately monitoring tropical forest carbon stocks is a challenge that remains outstanding. Allometric models that consider tree diameter, height and wood density as predictors are currently used in most tropical forest carbon studies. In particular, a pantropical biomass model has been widely used for approximately a decade, and its most recent version will certainly constitute a reference model in the coming years. However, this reference model shows a systematic bias towards the largest trees. Because large trees are key drivers of forest carbon stocks and dynamics, understanding the origin and the consequences of this bias is of utmost concern. In this study, we compiled a unique tree mass data set of 673 trees destructively sampled in five tropical countries (101 trees > 100 cm in diameter) and an original data set of 130 forest plots (1 ha) from central Africa to quantify the prediction error of biomass allometric models at the individual and plot levels when explicitly taking crown mass variations into account or not doing so. We first showed that the proportion of crown to total tree aboveground biomass is highly variable among trees, ranging from 3 to 88 %. This proportion was constant on average for trees = 45 Mg. This increase coincided with a progressive deviation between the pantropical biomass model estimations and actual tree mass. Taking a crown mass proxy into account in a newly developed model consistently removed the bias observed for large trees (> 1 Mg) and reduced the range of plot- level error (in %) from [-23; 16] to [0; 10]. The disproportionally higher allocation of large trees to crown mass may thus explain the bias observed recently in the reference pantropical model. This bias leads to far- from- negligible, but often overlooked, systematic errors at the plot level and may be easily corrected by taking a crown mass proxy for the largest trees in a stand into account, thus suggesting that the accuracy of forest carbon estimates can be significantly improved at a minimal cost