EFFECTS OF LIGHT INTENSITY ON DIVISION RATE,STIMULABLE BIOLUMINESCENCE AND CELL SIZE OF THE OCEANIC DINOFLAGELLATES DISSODINIUM LUNULA,PYROCYSTIS FUSIFORMIS AND P. NOCTILUCA12

Preadapted cultures were grown in a 12:12 LD cycle at a series of light intensities under cool-white, fluorescent lamps. Pyrocystis fusiformis Murray maintained high division rates at low light intensities at the expense of cell size. In contrast, Dissodinium lunula (Schuett) Taylor had relatively lower division rates at low light intensities with little concomitant decrease in size. The response of P. noctiluca Murray was intermediate between these two species. For all three, cell numbers did not increase above an intensity of 5–10 μEin·m^?2·sec^?1 and division rate was saturated at ca. 30, 60, and 60μEin·m^?2·sec^?1 for P. fusiformis, P. noctiluca, and D. lunula, respectively. The capacity for stimulable bioluminescence was saturated at light intensities of 0.15 μEin·m^?2·day in short-term (2-day) experiments. In cultures of P. fusiformis and P. noctiluca, maintained for at least one month at lower intensities than needed to saturate division rate, a decrease in the capacity for stimulable bioluminescence was accompanied by a reduction in cell size. Our results suggest that cell size and bioluminescent capacity may prove to be a potentially useful indication of the history of exposure of natural populations of Pyrocystis spp. to ambient intensities.     

Global diversity and balancing selection of 23 leading Plasmodium falciparum candidate vaccine antigens

Investigation of the diversity of malaria parasite antigens can help prioritize and validate them as vaccine candidates and identify the most common variants for inclusion in vaccine formulations. Studies of vaccine candidates of the most virulent human malaria parasite, Plasmodium falciparum, have focused on a handful of well-known antigens, while several others have never been studied. Here we examine the global diversity and population structure of leading vaccine candidate antigens of P. falciparum using the MalariaGEN Pf3K (version 5.1) resource, comprising more than 2600 genomes from 15 malaria endemic countries. A stringent variant calling pipeline was used to extract high quality antigen gene ‘haplotypes’ from the global dataset and a new R-package named VaxPack was used to streamline population genetic analyses. In addition, a newly developed algorithm that enables spatial averaging of selection pressure on 3D protein structures was applied to the dataset. We analysed the genes encoding 23 leading and novel candidate malaria vaccine antigens including csp, trap, eba175, ama1, rh5, and CelTOS. Our analysis shows that current malaria vaccine formulations are based on rare haplotypes and thus may have limited efficacy against natural parasite populations. High levels of diversity with evidence of balancing selection was detected for most of the erythrocytic and pre-erythrocytic antigens. Measures of natural selection were then mapped to 3D protein structures to predict targets of functional antibodies. For some antigens, geographical variation in the intensity and distribution of these signals on the 3D structure suggests adaptation to different human host or mosquito vector populations. This study provides an essential framework for the diversity of P. falciparum antigens to be considered in the design of the next generation of malaria vaccines.     

Reduced expressions of calmodulin genes and protein and reduced ability of calmodulin to activate plasma membrane Ca2+‐ATPase in the brain of protein undernourished rats: modulatory roles of selenium and zinc supplementation

The roles of protein undernutrition as well as selenium (Se) and zinc (Zn) supplementation on the ability of calmodulin (CaM) to activate erythrocyte ghost membrane (EGM) Ca²⁺‐ATPase and the calmodulin genes and protein expressions in rat's cortex and cerebellum were investigated. Rats on adequate protein diet and protein‐undernourished (PU) rats were fed with diet containing 16% and 5% casein, respectively, for a period of 10 weeks. The rats were then supplemented with Se and Zn at a concentration of 0.15 and 227 mg l⁻¹, respectively, in drinking water for 3 weeks. The results obtained from the study showed significant reductions in synaptosomal plasma membrane Ca²⁺‐ATPase (PMCA) activity, Ca²⁺/CaM activated EGM Ca²⁺ATPase activity and calmodulin genes and protein expressions in PU rats. Se or Zn supplementation improved the ability of Ca²⁺/CaM to activate EGM Ca²⁺‐ATPase and protein expressions. Se or Zn supplementation improved gene expression in the cerebellum but not in the cortex. Also, the activity of PMCA was significantly improved by Zn. In conclusion, it is postulated that Se and Zn might be beneficial antioxidants in protecting against neuronal dysfunction resulting from reduced level of calmodulin such as present in protein undernutrition. Copyright © 2016 John Wiley & Sons, Ltd.     

A comparative evaluation of phenotypic and molecular methods in the identification of members of the Staphylococcus sciuri group

Members of the Staphylococcus sciuri group (S. sciuri, S. lentus, and S. vitulinus) are coagulase-negative, novobiocin-resistant staphylococci that could be distinguished from other staphylococci on the basis of positive oxidase activity. In the present study, a scheme based on conventional methods and utilization of various carbohydrates was evaluated for the identification of oxidase-positive staphylococci, and validated using two molecular techniques. Of the 173 oxidase-positive staphylococcal tested strains, 161 were identified as S. sciuri, 9 as S. lentus, 2 as S. vitulinus, and one as S. fleurettii by our scheme. The level of agreement with tRNA intergenic length polymorphism analysis (tDNA-PCR) was high (97.5-100% correlation). The accuracy and ease of use of this protocol suggest that it may be useful and valuable in microbiological laboratories for the identification of members of this group.     

The wise use of wetlands: identifying development options for Ghana's coastal Ramsar sites

The Government of Ghana has recently declared five coastal wetlands to be Ramsar sites. This requires the wise use of wetlands of international importance for bird habitat, but does not preclude human habitation or ecologically friendly development. The sites are Muni-Pomadze, Densu Delta, Sakumo, Songor and Keta. An attempt was made to identify and assess a range of development options for initiation within the sites that would be compatible with the environmental concerns of Ramsar, while also being technically and economically viable and socially acceptable to the communities in the sites. The appraisal included developing a detailed understanding of the physical, biological, human and institutional resources of the areas, the land uses and prevailing livelihood systems of local people, and the pressures placed on the natural resources of the wetlands. Many of the developments nominated by stakeholders were rejected, but twenty topics passed the initial tests. These were considered in more detail using information collected for the study by national specialists. Most of the options were considered suitable for local level implementation by community groups or local entrepreneurs. Government assistance will be needed to ensure an enabling institutional framework for small-scale business development is provided.     

Safety,Effectiveness and Acceptability of the PrePex Device for Adult Male Circumcision in Kenya

Objective

To assess the safety, effectiveness and acceptability of the PrePex device for adult medical male circumcision (MMC) in routine service delivery in Kenya.

Methods

We enrolled 427 men ages 18–49 at one fixed and two outreach clinics. Procedures were performed by trained clinical officers and nurses. The first 50 enrollees were scheduled for six follow-up visits, and remaining men were followed at Days 7 and 42. We recorded adverse events (AEs) and time to complete healing, and interviewed men about acceptability and pain.

Results

Placement and removal procedures each averaged between 3 and 4 minutes. Self-reported pain was minimal during placement but was fleetingly intense during removal. The rate of moderate/severe AEs was 5.9% overall (95% confidence interval [CI] 3.8%–8.5%), all of which resolved without sequelae. AEs included 5 device displacements, 2 spontaneous foreskin detachments, and 9 cases of insufficient foreskin removal. Surgical completion of MMC was required for 9 men (2.1%). Among the closely monitored first 50 participants, the probability of complete healing by Day 42 was 0.44 (95% CI 0.30–0.58), and 0.90 by Day 56. A large majority of men was favorable about their MMC procedure and would recommend PrePex to friends and family.

Conclusions

The PrePex device was effective for MMC in Kenya, and well-accepted. The AE rate was higher than reported for surgical procedures there, or in previous PrePex studies. Healing time is longer than following surgical circumcision. Provider experience and clearer counseling on post-placement and post-removal care should lead to lower AE rates.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01711411","term_id":"NCT01711411"}}NCT01711411     

Production and potential biotechnological applications of microbial surfactants: An overview

Microbial surfactants are amphipathic molecules that consist of hydrophilic and hydrophobic domains, which allow partition of two fluid phases of varying degree of polarity. They are classified into two main groups: bioemulsifier and biosurfactant, depending on their molecular weight. Microbial surfactants occur in various categories according to their chemical nature and producing organisms. These biomolecules are produced by diverse groups of microorganisms including fungi, bacteria, and yeasts. Their production is significantly influenced by substrate type, fermentation technology and microbial strains. Owing to inherent multifunctional properties and assorted synthetic aptitude of the microbes, microbial surfactants are mostly preferred than their chemical counterparts for various industrial and biomedical applications including bioremediation, oil recovery; as supplements in laundry formulations and as emulsion-stabilizers in food and cosmetic industries as well as therapeutic agents in medicine. The present review discusses on production of microbial surfactants as promising and alternative broad-functional biomolecules for various biotechnological applications.     

Immunoinformatics Design of Multiepitope Vaccine Against Enterococcus faecium Infection

International Journal of Peptide Research and Therapeutics - Enterococcus faecium has emerged as the fourth most commonly isolated nosocomial pathogen due to its resistance to commonly used...     

Time to Complete Wound Healing in HIV-Positive and HIV-Negative Men following Medical Male Circumcision in Kisumu,Kenya: A Prospective Cohort Study

Background

While voluntary medical male circumcision (VMMC) has been shown to be protective against HIV-acquisition, the procedure may place men and their partners at risk of HIV infection in the period following circumcision if sex is resumed before the wound is healed. This prospective cohort study evaluates post-circumcision wound healing to determine whether the 42-day post-circumcision abstinence period, recommended by the World Health Organization and adopted by VMMC programs, is optimal.

Methods and Findings

Men were circumcised by forceps-guided method and their post-circumcision wounds examined weekly for seven weeks and at 12 weeks. Time to complete healing was recorded in completed weeks since circumcision, and its associations with baseline covariates were assessed by Kaplan-Meier methods and Cox Proportional Hazard Models. A total of 215 HIV-negative and 108 HIV-positive men aged 18–35 years (median 26, IQR 23–30) were enrolled. 97.1% of scheduled follow-up visits were completed. At week 4, 59.3% of HIV-positive men and 70.4% of age-matched HIV-negative men were healed. At week 6, these percentages rose to 93.4% in HIV-positive men and 92.6% in age-matched HIV-negative men. There was no difference in the hazard of healing between 108 HIV-positive and 108 age-matched HIV-negative men (HR 0.91 95% CI 0.70–1.20). Early post-operative infection was associated with delayed healing in both HIV-positive and HIV-negative men (HR 0.48 95% CI 0.23–1.00).

Conclusions

Our results indicate that the WHO recommendation for 42-days post-circumcision sexual abstinence should be maintained for both HIV-positive and HIV-negative men. It is important to stress condom use upon resumption of sex in all men undergoing circumcision.