Human adipose derived stem cell exosomes enhance the neural differentiation of PC12 cells

Molecular Biology Reports - Human adipose stem cells (hADSCs) are proper cell sources for tissue regeneration. They mainly mediate their therapeutic effects through paracrine factors as exosomes....     

Antimicrobial susceptibility profiles associated with bacterial meningitis among children: a referral hospital-based study in Iran

Bacterial meningitis continues to be associated with high morbidity and mortality rate worldwide, especially in the pediatric age group. This study was performed to identify the microbial etiologies of meningitis among 31 children, who were admitted in the Emergency Ward of a referral pediatric hospital in Iran. Culture identification showed that Streptococcus pneumoniae (12 subjects), Haemophilus influenzae (11 subjects) were the most common bacteria, followed by Escherichia coli (7 cases) and Neisseria meningitidis (only one case). Antibiotic susceptibility tests revealed that vancomycin had the best effect on S. pneumoniae in comparison with other antibiotics, whereas H. influenzae and E. coli were more susceptible to ceftriaxone, ceftazidime, and ceftizoxime than other antibiotics. In conclusion, despite the advances in antibiotic therapy and vaccine development, bacterial meningitis still is a health problem. S. pneumoniae, H. influenzae, and N. meningitidis are the main sources of bacterial meningitis, but other organisms such as E. coli should also be suspected, when a case is admitted to a referral pediatric hospital.     

Prevalence and incidence of HIV in a rural community-based HIV vaccine preparedness cohort in Masaka, Uganda

Background

Local HIV epidemiology data are critical in determining the suitability of a population for HIV vaccine efficacy trials. The objective of this study was to estimate the prevalence and incidence of, and determine risk factors for HIV transmission in a rural community-based HIV vaccine preparedness cohort in Masaka, Uganda.

Methods

Between February and July 2004, we conducted a house-to-house HIV sero-prevalence survey among consenting individuals aged 18–60 years. Participants were interviewed, counseled and asked to provide blood for HIV testing. We then enrolled the HIV uninfected participants in a 2-year HIV sero-incidence study. Medical evaluations, HIV counseling and testing, and sample collection for laboratory analysis were done quarterly. Sexual risk behaviour data was collected every 6 months.

Results

The HIV point prevalence was 11.2%, and was higher among women than men (12.9% vs. 8.6%, P = 0.007). Risk factors associated with prevalent HIV infection for men were age <25 years (aOR = 0.05, 95% CI 0.01–0.35) and reported genital ulcer disease in the past year (aOR = 2.17, 95% CI 1.23–3.83). Among women, being unmarried (aOR = 2.59, 95% CI 1.75–3.83) and reported genital ulcer disease in the past year (aOR = 2.40, 95% CI 1.64–3.51) were associated with prevalent HIV infection. Twenty-one seroconversions were recorded over 2025.8 person-years, an annual HIV incidence of 1.04% (95% CI: 0.68–1.59). The only significant risk factor for incident HIV infection was being unmarried (aRR = 3.44, 95% CI 1.43–8.28). Cohort retention after 2 years was 87%.

Conclusions

We found a high prevalence but low incidence of HIV in this cohort. HIV vaccine efficacy trials in this population may not be feasible due to the large sample sizes that would be required. HIV vaccine preparatory efforts in this setting should include identification of higher risk populations.     

An efficient in vitro refolding of recombinant bacterial laccase in Escherichia coli

Laccases (benzenediol oxygen oxidoreductases, EC 1.10.3.2) are important multicopper enzymes that are used in many biotechnological processes. A recombinant form of laccase from Bacillus sp. HR03 was overexpressed in Escherichia coli BL-21(DE3). Inclusion body (IB) formation happens quite often during recombinant protein production. Hence, developing a protocol for efficient refolding of proteins from inclusion bodies to provide large amounts of active protein could be advantageous for structural and functional studies. Here, we have tried to find an efficient method of refolding for this bacterial enzyme. Solubilization of inclusion bodies was carried out in phosphate buffer pH 7, containing 8 M urea and 4 mM β-mercaptoethanol and refolding was performed using the dilution method. The effect of different additives was investigated on the refolding procedure of denaturated laccase. Mix buffer (phosphate buffer and citrate buffer, 100 mM) containing 4 mM ZnSO₄ and 100 mM sorbitol was selected as an optimized refolding buffer. Also Kinetic parameters of soluble and refolded laccase were analyzed.     

Designing an assistive robot for older adults: The ROBADOM project

ObjectiveThe ROBADOM project was devoted to the design of a “robot butler”, capable of providing verbal and non-verbal interactions and feedbacks for assisting older adults at home. In this article we focused on the following issues: (1) study the social context for designing social robot; define the robot appearance and investigate the perceptions and attitudes of older adults towards an assistive robot; (2) examine the perception of the expressivity of the robot, the social signals showing the end-user engagement level and the role of agent embodiment during the interaction between older adults and a robot.MethodThe design of the studies involved both qualitative and experimental methods.Results & DiscussionSmall robots with some traits between human/animal and machine were appreciated by the participants. As regards services, cognitive stimulation, reminder and object localization were positively rated. Although the participants considered an assistive robot as useful, they were not yet ready to adopt it. The expressions of the robot were perceived differently in older and young adults. Thus, a robotic system dedicated to older adults should be tailored to the specific characteristics of this population. We also identified social signals as indicators of the user's engagement level during interaction. Finally, the issue of the added valued of a robotic system in comparison to a laptop was raised by our participants. Therefore, various issues (technological development, human-robot interaction, social context…) are to be explored before testing the impact of the robot at home.     

Biocontrol potential of the entomopathogenic nematodes Heterorhabditis bacteriophora and Steinernema carpocapsae on cucurbit fly,Dacus ciliatus (Diptera: Tephritidae)

Entomopathogenic nematodes (EPNs) from the families Steinernematidae and Hererorhabditidae are considered excellent biological control agents against many insects that damage the roots of crops. In a regional survey, native EPNs were isolated, and laboratory and greenhouse experiments were conducted to determine the infectivity of EPNs against the cucurbit fly, Dacus ciliatus Loew (Diptera: Tephritidae). Preliminary experiments showed high virulence by a native strain of Heterorhabditis bacteriophora Poinar (Rhabditida: Heterorhabditidae) and a commercial strain of Steinernema carpocapsae Weiser (Rhabditida: Steinernematidae). These two strains were employed for further analysis while another native species, Steinernema feltiae, was excluded due to low virulence. In laboratory experiments, larvae and adult flies were susceptible to nematode infection, but both nematode species induced low mortality on pupae. S. carpocapsae had a significantly lower LC₅₀ value against larvae than H. bacteriophora in filter paper assays. Both species of EPNs were effective against adult flies but S. carpocapsae caused higher adult mortality. When EPN species were applied to naturally infested fruit (150 and 300 IJs/cm²), the mortality rates of D. ciliatus larvae were 28% for S. carpocapsae and 12% for H. bacteriophora. Both EPN strains successfully reproduced and emerged from larvae of D. ciliates. In a greenhouse experiment, H. bacteriophora and S. carpocapsae had similar effects on fly larvae. Higher rates of larval mortality were observed in sandy loam and sand soils than in clay loam. The efficacy of S. carpocapsae and H. bacteriophora was higher at 25 and 30°C than at 19°C. The results indicated that S. carpocapsae had the best potential as a biocontrol agent of D. ciliatus, based on its higher virulence and better ability to locate the fly larvae within infected fruits.     

Temperature-dependent development and life table parameters of <Emphasis Type="Italic">Typhlodromus bagdasarjani</Emphasis> (Phytoseiidae) fed on two-spotted spider mite

The predatory mite Typhlodromus bagdasarjani Wainstein and Arutunjan (Acari: Phytoseiidae) is an indigenous and widespread species of the Middle East fauna. In this paper we assess the effect of temperature on developmental rate and reproduction potential of T. bagdasarjani under laboratory conditions. The development of this species was determined at 15, 20, 25, 30, 35 and 37.5 ± 1°C, 60 ± 10% RH and L16:D8 h photoperiod. The total developmental time averaged 28.2, 15.0, 8.9, 7.6, 7.2 and 7.4 days at 15–37.5°C, respectively, when feeding on immature stages of two-spotted spider mite, Tetranychus urticae Koch. The lower developmental threshold (T ₀ ) and thermal constant (K) for the development of this predator were estimated 9.2°C and 162 degree-days by the Ikemoto linear model. The life table parameters were estimated at 15–35°C. The shortest life span of females at 35°C was 45.0 days, followed by 50.7, 50.9, 103.3 and 136.8 days at 30, 25, 20 and 15°C, respectively. Mated females laid on average 19.9, 26.3, 41.1, 39.6 and 31.3 eggs per female at 15–35°C, respectively. The intrinsic rate of increase (r _m ) and finite rate of increase (λ) increased significantly with increasing temperature. The r _m values ranged from 0.021 (15°C) to 0.186 (35°C) days⁻¹. The highest value of net reproductive rate (R ₀) was 13.6 females progeny/female/generation at 25°C. The results demonstrated that T. bagdasarjani is well adapted to high temperatures. However, the efficiency to control spider mites may be affected by behavioral characteristics of the predator and its prey under real conditions.     

An integrated chromosome map of microsatellite markers and inversion breakpoints for an Asian malaria mosquito, Anopheles stephensi

Anopheles stephensi is one of the major vectors of malaria in the Middle East and Indo-Pakistan subcontinent. Understanding the population genetic structure of malaria mosquitoes is important for developing adequate and successful vector control strategies. Commonly used markers for inferring anopheline taxonomic and population status include microsatellites and chromosomal inversions. Knowledge about chromosomal locations of microsatellite markers with respect to polymorphic inversions could be useful for better understanding a genetic structure of natural populations. However, fragments with microsatellites used in population genetic studies are usually too short for successful labeling and hybridization with chromosomes. We designed new primers for amplification of microsatellite loci identified in the A. stephensi genome sequenced with next-generation technologies. Twelve microsatellites were mapped to polytene chromosomes from ovarian nurse cells of A. stephensi using fluorescent in situ hybridization. All microsatellites hybridized to unique locations on autosomes, and 7 of them localized to the largest arm 2R. Ten microsatellites were mapped inside the previously described polymorphic chromosomal inversions, including 4 loci located inside the widespread inversion 2Rb. We analyzed microsatellite-based population genetic data available for A. stephensi in light of our mapping results. This study demonstrates that the chromosomal position of microsatellites may affect estimates of population genetic parameters and highlights the importance of developing physical maps for nonmodel organisms.