A Molecular-Level Investigation of Organic Interfaces: From Friction to Biosensors

Scanning probe techniques (SPM) and atomic force microscopy (AFM) in particular were used to study organic structures at the atomic and molecular level. Organic interfaces are of prime importance to several technological applications, such as boundary lubrication and biosensors development. Because these applications rely on molecular-scale recognition and control a fundamental, molecular-level understanding of their structural and physical-chemical properties is indispensable

Wavelet Kernel Principal Component Analysis in Noisy Multiscale Data Classification

We introduce multiscale wavelet kernels to kernel principal component analysis (KPCA) to narrow down the search of parameters required in the calculation of a kernel matrix. This new methodology incorporates multiscale methods into KPCA for transforming multiscale data. In order to illustrate application of our proposed method and to investigate the robustness of the wavelet kernel in KPCA under different levels of the signal to noise ratio and different types of wavelet kernel, we study a set of two-class clustered simulation data. We show that WKPCA is an effective feature extraction method for transforming a variety of multidimensional clustered data into data with a higher level of linearity among the data attributes. That brings an improvement in the accuracy of simple linear classifiers. Based on the analysis of the simulation data sets, we observe that multiscale translation invariant wavelet kernels for KPCA has an enhanced performance in feature extraction. The application of the proposed method to real data is also addressed.Peer Reviewe

An assessment of option B implementation for the prevention of mother to child transmission in Dschang, Cameroon: results from the DREAM (Drug Resource Enhancement against AIDS and Malnutrition) cohort

Introduction: Scaling up of antiretroviral therapy (ART) to HIV+ pregnant women is crucial for the elimination of HIV infection in children. The aim of this study was to evaluate the feasibility and effectiveness of triple ART for Prevention of Mother-to Child Transmission (PMTCT) in Cameroon. Methods: HIV-positive pregnant women attending the DREAM Centre of Dschang, Cameroon for prenatal care were enrolled in a prospective cohort study, and received ART until the end of breastfeeding or indefinitely if their CD4 count was <350mm3. Infants were evaluated for HIV infection at 1, 6 and 12 months of age. Results: A total of 298 women were enrolled. Among them, 152 were already on established ART. Women were followed until 6 months after delivery with a retention rate of 92.6%. Eight women died. Those with a CD4 count <350 cells/mm3 during pregnancy had the highest mortality risk (RR 2.53; 95% CL= 1.86-3.44). The HIV  transmission rate was 1.2% at 12 months with an HIV free survival of 91%. In the proportional Cox regression analysis, the following factors were positively associated with infant mortality: maternal CD4< 350 cells/mm3, no breastfeeding in the first 6 months of life, weight-for-age z score < -2. Conclusion: Results confirm the feasibility and effectiveness of the implementation of Option B, with very low rates of HIV MTC  transmission, and potential benefits to the health of mothers and infants with earlier initiation of ART. Breastfeeding again demonstrates to be highly beneficial for the growth and survival of HIV exposed children.Pan African Medical Journal 2016; 2

Systemic Immune Responses in Alzheimer’s Disease: In Vitro Mononuclear Cell Activation and Cytokine Production

To investigate the systemic signs of immune-inflammatory responses in Alzheimer’s disease (AD), in the present study we have analyzed blood lymphocyte subsets and the expression of activation markers on peripheral blood mononuclear cells (PBMCs) fromADpatients and age-matched healthy controls (HC) activated in vitro by recombinant amyloid-β peptide (rAβ42). Our study of AD lymphocyte subpopulations confirms the already described decrease of the absolute number and percentage of B cells when compared to HC lymphocytes, whereas the other subsets are not significantly different in patients and controls. We report the increased expression of the activation marker CD69 and of the chemokine receptors CCR2 and CCR5 on T cells but no changes of CD25 after activation. B cells are also activated by rAβ42 as demonstrated by the enhanced expression of CCR5. Moreover, rAβ42 induces an increased expression of the scavenger receptor CD36 on monocytes. Some activation markers and chemokine receptors are overexpressed in unstimulated AD cells when compared to controls. This is evidence of the pro-inflammatory status of AD. Stimulation by rAβ42 also induces the production of the pro-inflammatory cytokines IL-1β, IL-6, IFN-γ, and TNF-α, and of the anti-inflammatory cytokines IL-10 and IL-1Ra. The chemokines RANTES, MIP-1β, and eotaxin as well as some growth factors (GM-CSF, G-CSF) are also overproduced by AD-derived PBMC activated by rAβ42. These results support the involvement of systemic immunity in AD patients. However, our study is an observational one so we cannot draw a conclusion about its contribution to the pathophysiology of the disease

Nutritional Rehabilitation of HIV-Exposed Infants in Malawi: Results from the Drug Resources Enhancement Against AIDS and Malnutrition Program

Infant malnutrition in sub-Saharan Africa is a public health priority and a challenge in high HIV prevalence areas. The Drug Resources Enhancement Against AIDS and Malnutrition program, with multiple medical centers in Sub-Saharan Africa, developed an innovative intervention for the surveillance and control of malnutrition. In a pilot initiative, 36 HIV-exposed children were evaluated at baseline upon presentation for malnutrition and at six months post- treatment. Parameters included HIV-free survival, nutritional status and change in diet. Food diary data was entered and processed using the Nutrisurvey (WHO) software. At 6 months post-intervention, a significant improvement in anthropometric parameters was noted. Slowing of linear growth was observed in patients with malaria with a mean gain in centimetres of 4.4 ± 1.7 as compared to 5.6 ± 1.7 in children with no malaria, p < 0.048 (CL 95%: −2.32, −0.01). Dietary diversity scores increased from 5.3 ± 1.9 to 6.5 ± 1.3, p < 0.01 at 6 months. A significant increase (+25%, p < 0.02) in the number of children eating fish meals was noted. Our pilot data describes positive outcomes from a rehabilitative nutritional approach based on use of local foods, peer education, anthropometric and clinical monitoring in areas of high food insecurity. The relationship between malaria and linear growth retardation requires further investigation

IL28B and IL10R -1087 polymorphisms are protective for chronic genotype 1 HCV infection and predictors of response to interferon-based therapy in an East-Central European cohort.

BACKGROUND: Previous studies have shown that single nucleotide polymorphisms (SNP) in IL28B and IL10R are associated with sustained virological response (SVR) in chronic hepatitis C patients treated with pegilated interferon plus ribavirin (P/R). The present study extends our earlier investigations on a large East-Central European cohort. The allele frequencies of IL28B and IL10R in genotype 1 HCV infection were compared with that of healthy controls for the purpose of examining the relationship between the polymorphisms and the SVR to P/R treatment. METHODS: A total of 748 chronic HCV1 infected patients (365 male, 383 female; 18-82 years) and 105 voluntary blood donors as controls were enrolled. Four hundred and twenty HCV patients were treated with P/R for 24-72 weeks, out of them 195 (46.4%) achieved SVR. The IL28 rs12979860 SNP was determined using Custom Taqman SNP Genotyping Assays. The IL10R -1087 (also known as IL10R -1082 (rs1800896) promoter region SNP was determined by RT-PCR and restriction fragment length polymorphism analysis. RESULTS: The IL28B CC genotype occurred with lower frequency in HCV patients than in controls (26.1% vs 51.4%, p<0.001). P/R treated patients with the IL28B CC genotype achieved higher SVR rate, as compared to patients with CT (58.6% vs 40.8%, p=0.002). The prevalence of IL10R -1087 GG genotype was lower in patients than in controls (31.8 % vs 52.2%, p<0.001). Among patients achieving SVR, the IL10R -1087 GG genotype occurred with higher frequency than the AA (32.0% vs 17.4%, p=0.013). The IL28B T allele plus IL10R A allele combination was found with higher prevalence in patients than in controls (52% vs 20.7%, p<0.001). The IL28B CC plus IL10R A allele combination occurred with higher frequency among patients with SVR than in non-responders (21.3% vs 12.8%, p=0.026). Both the IL28B CC plus IL10R GG and the IL28B CC plus IL10R A allele combinations occurred with lower frequency in patients than in controls. CONCLUSIONS: In our HCV1 patients, both the IL28B CC and IL10R GG genotypes are associated with clearance of HCV. Moreover, distinct IL28B and IL10R allele combinations appear to be protective against chronic HCV1 infection and predictors of response to P/R therapy

Inflammatory and Immunological parameters in adults with Down syndrome

<p>Abstract</p> <p>Background</p> <p>The increase in life expectancy within the general population has resulted in an increasing number of elderly adults, including patients with Down syndrome (DS), with a current life expectancy of about 50 years. We evaluate the parameters of humoral and cellular immune response, the quantitative expression of the regulator of calcineurin1 gene (RCAN1) and the production of cytokines. The study group consisted of adults DS (n = 24) and a control group with intellectual disability without Down syndrome (ID) (n = 21) and living in a similar environmental background. It was evaluated serology, immunophenotyping, the quantitative gene expression of RCAN1 and the production of cytokines.</p> <p>Results</p> <p>In the DS group, the results showed an increase in NK cells, CD8, decreased CD19 (p < 0.05) and an increase spontaneous production of IFNgamma, TNFalpha and IL-10 (p < 0.05). There was not any difference in RCAN1 gene expression between the groups.</p> <p>Conclusions</p> <p>These data suggest a similar humoral response in the two groups. The immunophenotyping suggests sign of premature aging of the immune system and the cytokine production show a proinflammatory profile.</p