Active substance from some blue green algal species used as antimicrobial agents

The concept of biological control for health maintenance has received widespread attention during the last few years. Therefore, the main objective of this work was to look for active substances that couldbe used as antimicrobial agents in an efficient and safe manner. To achieve this target, five different extracts (ethyl acetate, chloroform, diethyl ether, methanol and water) from three blue green algalspecies (Anabaena flos aquae (Linnaeus) Bory; Anabaena variabilis (Kützing) and Oscillatoria angustissima West and West) were examined. This different algal extracts were tested in vitro for their antimicrobial effects against eight Gram +ve and Gram -ve bacteria in addition to two groups of fungi (filamentous fungi and yeast) using agar well diffusion method. The results showed that the ethyl acetate extract of A. flos aquae notably inhibited nearly the whole tested bacteria and filamentous fungiwith minimal activity against tested yeasts. Furthermore, a significant reduction in sporulation as well as dry weight of the two filamentous fungi was found with ethyl acetate extracts. The toxicity of ethyl acetate extract to Artemia salina showed that the effective concentration that would inhibit their growth by 50% (LC50) after 24 h of incubation was 17, 41 and 45 mg.ml-1 for A. flos aquae, A. variabilis and O. angustissima, respectively. The antagonistic materials from ethyl acetate extract of differentcyanobacterial species were identified using gas liquid chromatography mass spectrometer (GC-MS). The main components of ethyl acetate extract of A. flos aquae consisted of heptadecane and 7-methylheptadecane representing 26.11 and 18.65%, respectively

Comparative effects of autotrophic and heterotrophic growth on some vitamins, 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity, amino acids and protein profile of Chlorella vulgaris Beijerinck

Chemical composition of Chlorella vulgaris Beijerinck including content of some vitamins (A, E and C), 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity, amino acids and protein profile was assessed under autotrophic and heterotrophic growth conditions as an indication of its nutritional value. Vitamin content (A, E and C) of heterotrophic cells increased by about 29, 52 and 20, respectively, as compared to its value for autotrophic cells. The free radical scavenging activity (RSA) was significantly higher for autotrophic cells than heterotrophic only at low concentrations (25 and 50 μl) of algal extract, but no significant difference was recorded at high concentration (100 μl). This result indicates non parallel relationship between the tested vitamins and RSA which suggest that other nonenzymatic antioxidants and/or antioxidant enzymes are involved. Concentration of essential and non essential amino acids in heterotrophic cells was double and 1.5 times, respectively its concentration in autotrophic cells. Histidine, lysine and phenylalanine constituted 77 and 44% of the total content of essential amino acids in heterotrophic and autotrophic cells, respectively. Methionine concentration was low in both types of cells. Proline content and non essential amino acid in heterotrophic cells was about 2.5 times its corresponding value in autotrophic cells. SDS-PAGE of protein extracts of autotrophic and heterotrophic C. vulgaris revealed two protein bands of molecular weight of ~75 and ~39 KDa. Higher intensity of the two bands was observed for autotrophic cells which may be associated with the effect of growth condition on the expression of regulatory genes. For valuable production of natural food supplement and/or natural pharmaceutical products, using heterotrophic cells rather than autotrophic cells for its richness in vitamins and essential amino acids is recommended.Key words: Autotrophic, heterotrophic, Chlorella vulgaris, vitamins, 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity, amino acid, protein profile

Nanosized nickel hexacyanoferrate modified screen-printed electrodes as flexible supercabattery platforms: Influence of annealing temperatures and supporting electrolytes

Water-insoluble nickel hexacyanoferrate Ni3[Fe(CN)6]2.nH2O (NiHCF) nanoparticles were synthesized via a facile precipitation method in the presence of polyvinylpyrrolidone (PVP) and sodium citrate (SC). Large-scale production of cubic NiHCF crystals with an average diameter of 35 nm and a specific surface area (SBET) of 452.9 m2/g was shown to be possible. The NiHCF nanoparticles were drop-cast upon screen-printed graphite macroelectrode surfaces (SPEs) allowing a flexible energy storage device to be realised. The tunable pore size and dual functional reactive sites offered superior specific capacitances of 197.5, 139.35, 356.25, and 406.25 F/g in 0.1 M KCl, 0.1 M NaCl, 0.1 M NaOH and 0.1 M KOH, respectively at a current density of 5 A/g. The highest capacitance was found using 0.1 M KOH supporting electrolyte due to the combination of surface (intercalation/de-intercalation of A+) and faradaic processes (M2+/M3+) as supercabattery platforms. The thermal treatment of the NiHCF samples at 100, 200, 300 °C were performed within oxygen and nitrogen atmospheres and the specific capacitances were measured in 0.1 M KOH. Interestingly, the specific capacitance increases up to 546 F/g for NiHCF annealed at 100 °C in oxygen and reduces to 342 F/g if NiHCF when annealed at 200 °C in nitrogen atmospheres due to the likely introduction of diverse vacancies. Furthermore, the NiHCF/SPEs were investigated in an as-symmetric two-electrode system, which revealed a specific capacitance of 570 F/g at 5 A/g. The NiHCF/SPE exhibited high capability rate, capacitive retention and excellent cycling stabilities particularly if NiHCF was annealed within a nitrogen atmosphere. Thus, the NiHCF supercabattery platforms can be used for developing new flexible energy storage devices

Simultaneous voltammetric determination of antihypertensive drugs nifedipine and atenolol utilizing MgO nanoplatelet modified screen-printed electrodes in pharmaceuticals and human fluids

© 2017 The Authors. Nifedipine and atenolol dugs are conjugated in several anti-hypertensive pharmaceutical formulations. Herein, a reproducible and sensitive voltammetric procedure has been developed for the simultaneous analysis of nifedipine and atenolol for the first time using MgO − nanoplatelets modified screen-printed electrodes (MgO − SPEs) via differential pulse voltammetry (DPV). Two very well-resolved and reproducible signals/oxidation peaks with a voltammetric separation of 0.35 V were obtained in Britton–Robinson (BR) buffer (pH 9). The MgO NPLs are found to exhibit a high electrocatalytic activity and improved voltammetric response compared to unmodified (bare) SPEs. Under optimum pH conditions (pH 9), the DPV curves exhibit linear responses to nifedipine and atenolol over the concentration ranges of 0.2–104.41 μM and 6.66–909.09 μM with detection limits of 0.032 μM and 1.76 μM, respectively. The applicability of the MgO-SPEs is successfully utilized for simultaneous determination of nifedipine and atenolol in pharmaceutical tablets and human urine samples with good accuracy and precision, these results agreeing with independent high-performance liquid chromatography (HPLC)

The App-Runx1 Region Is Critical for Birth Defects and Electrocardiographic Dysfunctions Observed in a Down Syndrome Mouse Model

Down syndrome (DS) leads to complex phenotypes and is the main genetic cause of birth defects and heart diseases. The Ts65Dn DS mouse model is trisomic for the distal part of mouse chromosome 16 and displays similar features with post-natal lethality and cardiovascular defects. In order to better understand these defects, we defined electrocardiogram (ECG) with a precordial set-up, and we found conduction defects and modifications in wave shape, amplitudes, and durations in Ts65Dn mice. By using a genetic approach consisting of crossing Ts65Dn mice with Ms5Yah mice monosomic for the App-Runx1 genetic interval, we showed that the Ts65Dn viability and ECG were improved by this reduction of gene copy number. Whole-genome expression studies confirmed gene dosage effect in Ts65Dn, Ms5Yah, and Ts65Dn/Ms5Yah hearts and showed an overall perturbation of pathways connected to post-natal lethality (Coq7, Dyrk1a, F5, Gabpa, Hmgn1, Pde10a, Morc3, Slc5a3, and Vwf) and heart function (Tfb1m, Adam19, Slc8a1/Ncx1, and Rcan1). In addition cardiac connexins (Cx40, Cx43) and sodium channel sub-units (Scn5a, Scn1b, Scn10a) were found down-regulated in Ts65Dn atria with additional down-regulation of Cx40 in Ts65Dn ventricles and were likely contributing to conduction defects. All these data pinpoint new cardiac phenotypes in the Ts65Dn, mimicking aspects of human DS features and pathways altered in the mouse model. In addition they highlight the role of the App-Runx1 interval, including Sod1 and Tiam1, in the induction of post-natal lethality and of the cardiac conduction defects in Ts65Dn. These results might lead to new therapeutic strategies to improve the care of DS people

Congenital and childhood atrioventricular blocks: pathophysiology and contemporary management

Atrioventricular block is classified as congeni- tal if diagnosed in utero, at birth, or within the first month of life. The pathophysiological process is believed to be due to immune-mediated injury of the conduction system, which occurs as a result of transplacental pas- sage of maternal anti-SSA/Ro-SSB/La antibodies. Childhood atrioventricular block is therefore diagnosed between the first month and the 18th year of life. Genetic variants in multiple genes have been described to date in the pathogenesis of inherited progressive car- diac conduction disorders. Indications and techniques of cardiac pacing have also evolved to allow safe perma- nent cardiac pacing in almost all patients, including those with structural heart abnormalities

Pooled analysis of WHO Surgical Safety Checklist use and mortality after emergency laparotomy

Background The World Health Organization (WHO) Surgical Safety Checklist has fostered safe practice for 10 years, yet its place in emergency surgery has not been assessed on a global scale. The aim of this study was to evaluate reported checklist use in emergency settings and examine the relationship with perioperative mortality in patients who had emergency laparotomy. Methods In two multinational cohort studies, adults undergoing emergency laparotomy were compared with those having elective gastrointestinal surgery. Relationships between reported checklist use and mortality were determined using multivariable logistic regression and bootstrapped simulation. Results Of 12 296 patients included from 76 countries, 4843 underwent emergency laparotomy. After adjusting for patient and disease factors, checklist use before emergency laparotomy was more common in countries with a high Human Development Index (HDI) (2455 of 2741, 89.6 per cent) compared with that in countries with a middle (753 of 1242, 60.6 per cent; odds ratio (OR) 0.17, 95 per cent c.i. 0.14 to 0.21, P <0001) or low (363 of 860, 422 per cent; OR 008, 007 to 010, P <0.001) HDI. Checklist use was less common in elective surgery than for emergency laparotomy in high-HDI countries (risk difference -94 (95 per cent c.i. -11.9 to -6.9) per cent; P <0001), but the relationship was reversed in low-HDI countries (+121 (+7.0 to +173) per cent; P <0001). In multivariable models, checklist use was associated with a lower 30-day perioperative mortality (OR 0.60, 0.50 to 073; P <0.001). The greatest absolute benefit was seen for emergency surgery in low- and middle-HDI countries. Conclusion Checklist use in emergency laparotomy was associated with a significantly lower perioperative mortality rate. Checklist use in low-HDI countries was half that in high-HDI countries.Peer reviewe

Global variation in anastomosis and end colostomy formation following left-sided colorectal resection

Background End colostomy rates following colorectal resection vary across institutions in high-income settings, being influenced by patient, disease, surgeon and system factors. This study aimed to assess global variation in end colostomy rates after left-sided colorectal resection. Methods This study comprised an analysis of GlobalSurg-1 and -2 international, prospective, observational cohort studies (2014, 2016), including consecutive adult patients undergoing elective or emergency left-sided colorectal resection within discrete 2-week windows. Countries were grouped into high-, middle- and low-income tertiles according to the United Nations Human Development Index (HDI). Factors associated with colostomy formation versus primary anastomosis were explored using a multilevel, multivariable logistic regression model. Results In total, 1635 patients from 242 hospitals in 57 countries undergoing left-sided colorectal resection were included: 113 (6·9 per cent) from low-HDI, 254 (15·5 per cent) from middle-HDI and 1268 (77·6 per cent) from high-HDI countries. There was a higher proportion of patients with perforated disease (57·5, 40·9 and 35·4 per cent; P < 0·001) and subsequent use of end colostomy (52·2, 24·8 and 18·9 per cent; P < 0·001) in low- compared with middle- and high-HDI settings. The association with colostomy use in low-HDI settings persisted (odds ratio (OR) 3·20, 95 per cent c.i. 1·35 to 7·57; P = 0·008) after risk adjustment for malignant disease (OR 2·34, 1·65 to 3·32; P < 0·001), emergency surgery (OR 4·08, 2·73 to 6·10; P < 0·001), time to operation at least 48 h (OR 1·99, 1·28 to 3·09; P = 0·002) and disease perforation (OR 4·00, 2·81 to 5·69; P < 0·001). Conclusion Global differences existed in the proportion of patients receiving end stomas after left-sided colorectal resection based on income, which went beyond case mix alone

Epithelium-on corneal cross-linking treatment of progressive keratoconus: a prospective, consecutive study

Hany A Khairy, Hatem M Marey, Amin Faisal Ellakwa Ophthalmology Department, Menoufia University Hospitals, Menofia, Egypt Purpose: To evaluate the outcome of collagen cross-linking (CXL) without corneal epithelial debridement in patients treated for progressive keratoconus for whom the standard epithelium-off treatment cannot be applied, as their central corneal thickness (CCT) is less than 400 &micro;m. Patients and methods: This was a prospective, uncontrolled, interventional study involving 32 eyes of 30 patients with progressive keratoconus and CCT of less than 400 &micro;m. All patients received CXL treatment with application of riboflavin and exposure to ultraviolet light A for 30 minutes without corneal epithelial debridement. Patients were followed up to 12 months postoperatively. The main outcomes were changes in maximum-K reading, manifest refractive spherical equivalent, CCT, and best-corrected visual acuity (logarithm of minimum angle of resolution). Patients were also asked to report any pain or discomfort during the procedure. Results: At the end of the 12-month follow-up, CCT showed no significant change: from 392&plusmn;5.17 &micro;m preoperatively to 390&plusmn;4.45 &micro;m (P=0.102). Maximum-K reading decreased significantly, from 49.19&plusmn;2.30 D preoperatively to 46.96&plusmn;6.03 D postoperatively (P&lt;0.05). The mean manifest spherical equivalent showed no significant change: from 4.04&plusmn;1.51 D preoperatively to 4.17&plusmn;1.63 D postoperatively (P=0.110). Mean best-corrected visual acuity showed no significant change: from 0.29&plusmn;0.12 preoperatively to 0.31&plusmn;0.11 postoperatively (P=0.110). Conclusion: Epithelium-on CXL exhibits potential as a method for treating patients with progressive keratoconus and CCT of less than 400 &micro;m, in which the standard epithelium-off CXL cannot be applied. Over 12 months of follow-up, the epithelium-on CXL was safe and effective, with results comparable to that achieved with the epithelium-off technique in thicker corneas, and reduced rates of operative and postoperative discomfort. Keywords: keratoconus, cross-linking, refractive surgery, epitheliu