Drosophila Avoids Parasitoids by Sensing Their Semiochemicals via a Dedicated Olfactory Circuit

Detecting danger is one of the foremost tasks for a neural system. Larval parasitoids constitute clear danger to Drosophila, as up to 80% of fly larvae become parasitized in nature. We show that Drosophila melanogaster larvae and adults avoid sites smelling of the main parasitoid enemies, Leptopilina wasps. This avoidance is mediated via a highly specific olfactory sensory neuron (OSN) type. While the larval OSN expresses the olfactory receptor Or49a and is tuned to the Leptopilina odor iridomyrmecin, the adult expresses both Or49a and Or85f and in addition detects the wasp odors actinidine and nepetalactol. The information is transferred via projection neurons to a specific part of the lateral horn known to be involved in mediating avoidance. Drosophila has thus developed a dedicated circuit to detect a life-threatening enemy based on the smell of its semiochemicals. Such an enemy-detecting olfactory circuit has earlier only been characterized in mice and nematodes.     

The Menace of Schistosomiasis in Nigeria: Knowledge,Attitude, and Practices Regarding Schistosomiasis among Rural Communities in Kano State

Background

Schistosomiasis is one of the most common neglected tropical diseases, especially in the developing countries in Africa, Asia and South America, with Nigeria having the greatest number of cases of schistosomiasis worldwide. This community-based study aims to evaluate the knowledge, attitude and practices (KAP) regarding schistosomiasis among rural Hausa communities in Kano State, Nigeria.

Methods

A cross-sectional study was carried out among 551 participants from Hausa communities in five local government areas in Kano State, North Central Nigeria. Demographic, socioeconomic and environmental information as well as KAP data were collected using a pre-tested questionnaire. Moreover, faecal and urine samples were collected and examined for the presence of Schistosoma mansoni and S. haematobium eggs respectively.

Results

The overall prevalence of schistosomiasis was 17.8%, with 8.9% and 8.3% infected with S. mansoni and S. haematobium respectively, and 0.5% had co-infection of both species. Moreover, 74.5% of the participants had prior knowledge about schistosomiasis with 67.0% of them how it is transmitted and 63.8% having no idea about the preventive measures. Three-quarters of the respondents considered schistosomiasis a serious disease while their practices to prevent infections were still inadequate, with only 34.7% of them seeking treatment from clinics/hospitals. Significant associations between the KAP and age, gender, education and employment status were reported. Multiple logistic regression analysis revealed that age, gender, history of infection and educational level of the respondents were the most important factors significantly associated with the KAP on schistosomiasis among this population.

Conclusions

Schistosomiasis is still prevalent among Hausa communities in Nigeria and participants’ knowledge about the disease was poor. Mass drug administration, community mobilization and health education regarding the cause, transmission and prevention of schistosomiasis and education about good personal and sanitary hygiene practices should be considered in order to significantly reduce the prevalence and morbidity of infection within these communities.     

Effect of heat‐assisted pulsed electric fields and bacteriophage on enterohemorrhagic Escherichia coli O157:H7

Pulsed electric fields (PEF), heat‐assisted PEF (H‐PEF), and virulent bacteriophage (VP) are non‐thermal techniques for pathogen inactivation in liquids that were investigated individually, and in combination (PEF/VP, H‐PEF/VP) to control enterohemorrhagic Escherichia coli (EHEC) O157:H7 in Luria‐Bertani broth (LBB) and Ringer's solution (RS). Treated cells were subsequently incubated at refrigeration (4°C) and temperature‐abuse conditions (12°C) for 5 days. When EHEC cells grown in LBB were subjected to non‐thermal processing and subsequently stored at 12°C for 5 days, reductions in count of between 0.1 and 0.6 log cycles were observed and following storage at 4°C the decrease in counts varied between 0.2 and 1.1 log₁₀. For bacteria cells suspended in RS values ranged from 0.1 to ≥3.9 log cycles at both storage temperatures. The most effective treatments were H‐PEF and H‐PEF/VP, both producing a >3.4 log cycle reduction of cells suspended in non‐nutrient RS. Analysis of EHEC recovery on selective and non‐selective media indicated no occurrence of sub‐lethal damage for VP, PEF/VP, and H‐PEF/VP‐treated cells. The findings indicate that combining PEF and lytic phage may represent a suitable alternative to conventional fluid decontamination following further process optimization. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 31:110–118, 2015     

Serum netrin and VCAM-1 as biomarker for Egyptian patients with type IΙ diabetes mellitus

ObjectiveThis study aimed to evaluate the serum level of netrin and soluble vascular cell adhesion molecule 1 (VCAM-I) in patients with type IΙ diabetes mellitus (T2DM) and evaluate the association of their levels with the development of a diabetic complication.Patients and methodsThis study was carried out on type II diabetic patients with and without complications and healthy individuals served as controls. All subjects were submitted to the estimation of serum lipid profile, serum creatinine, urinary albumin/creatinine ratio (ACR), fasting blood glucose (FBG), glycated hemoglobin (HbA1c), visceral adiposity index (VAI), atherogenic index of plasma (AIP), lipid accumulation product (LAP) and detection of serum level of netrin1 and VCAM1.ResultsDiabetic patients with complications had significantly higher serum levels of creatinine, ACR, cholesterol, Triglyceride, low-density lipoprotein, netrin1, and VCAM1 than diabetic patients without complications. Likewise, the level of VAI and LAP as markers of excessive body fat were significantly higher in diabetic patients with complications than diabetic patients without complications. The netrin1 and VCAM1 were a significant discriminator of T2DM renal complications with a sensitivity of 96%, 90%, and specificity of 82.7%, 91.3% respectively.ConclusionIt can be concluded that serum netrin1 and VCAM1 correlated significantly with markers of excessive body fat, a renal complication in the patient with type 2 diabetes mellitus.     

Design,synthesis and biological evaluation of novel triaryl (Z)-olefins as tamoxifen analogues

Tamoxifen (TAM) is used for the treatment and prevention of estrogen receptor positive breast cancer. However, the limited activity, toxicity and the development of resistance raised the current need for new potent nontoxic antiestrogen. Six novel TAM analogues 5a–f were synthesized using McMurry olefination reaction. Replacement of the dimethylamino group in TAM by piperidino, piperazino or N-methyl piperazino, substituting the phenyl ring with florine atom at p-position and changing the ethyl group by methyl, afforded compounds showing comparable activity to TAM (1). Compounds 5c and 5e showed significant increase in antiproliferative activity in two breast cancer cell lines (MCF-7 and MDA-MB-231) compared to tamoxifen, while other compounds showed similar activity. The increased anticancer activity of compounds 5c and 5e was attributed to their ability to induce ER-independent cell death.     

Effectiveness of the entomopathogenic nematode <Emphasis Type="Italic">Steinernema feltiae</Emphasis> in agar gel formulations against larvae of the Colarado potato beetle, <Emphasis Type="Italic">Leptinotarsa decemlineata</Emphasis> (Say.) (Coleoptera: Chrysomelidae)

The entomopathogenic nematode Steinernema feltiae strain Ustinov Russia was used on potato foliage to control larvae of the Colorado potato beetle, Leptinotarsa decemlineata (Say.) (Coleoptera: Chrysomelidae). Nematodes were applied in formulations of agar at 4%, 2%, 1% and 0.5% concentrations and compared to a control application of nematodes in water for nematode survival. Agar formulation significantly improved efficacy by increasing nematode survival through reduction in desiccation when compared to water-based formulation. More than 70% of infective juvenile nematodes (IJs) died after being incubated in the highest concentration of agar for 12 h, while only 8% mortality was recorded at the 1% concentration. Suspension of nematodes in 1% agar gel was shown to be efficacious in both laboratory and greenhouse tests for extension of the nematodes’ survival. Agar formulation droplets dried slower than control droplets by 127.8 min. Leptinotarsa decemlineata mortality significantly increased when insects were exposed to infective juvenile nematodes for four hours after application. In conclusion, the agar formulation enhanced nematode survival by providing a suitable environment thereby delaying dryingand increasing the possibility for nematodes to invade their host on the foliage.     

Ablation of Neuronal Ceramide Synthase 1 in Mice Decreases Ganglioside Levels and Expression of Myelin-associated Glycoprotein in Oligodendrocytes

Ceramide synthase 1 (CerS1) catalyzes the synthesis of C18 ceramide and is mainly expressed in the brain. Custom-made antibodies to a peptide from the C-terminal region of the mouse CerS1 protein yielded specific immunosignals in neurons but no other cell types of wild type brain, but the CerS1 protein was not detected in CerS1-deficient mouse brains. To elucidate the biological function of CerS1-derived sphingolipids in the brain, we generated CerS1-deficient mice by introducing a targeted mutation into the coding region of the cers1 gene. General deficiency of CerS1 in mice caused a foliation defect, progressive shrinkage, and neuronal apoptosis in the cerebellum. Mass spectrometric analyses revealed up to 60% decreased levels of gangliosides in cerebellum and forebrain. Expression of myelin-associated glycoprotein was also decreased by about 60% in cerebellum and forebrain, suggesting that interaction and stabilization of oligodendrocytic myelin-associated glycoprotein by neuronal gangliosides is due to the C18 acyl membrane anchor of CerS1-derived precursor ceramides. A behavioral analysis of CerS1-deficient mice yielded functional deficits including impaired exploration of novel objects, locomotion, and motor coordination. Our results reveal an essential function of CerS1-derived ceramide in the regulation of cerebellar development and neurodevelopmentally regulated behavior.