An observational prospective study of topical acidified nitrite for killing methicillin-resistant Staphylococcus aureus (MRSA) in contaminated wounds

Background Endogenous nitric oxide (NO) kills bacteria and other organisms as part of the innate immune response. When nitrite is exposed to low pH, NO is generated and has been used as an NO delivery system to treat skin infections. We demonstrated eradication of MRSA carriage from wounds using a topical formulation of citric acid (4.5%) and sodium nitrite (3%) creams co-applied for 5 days to 15 wounds in an observational prospective pilot study of 8 patients. Findings Following treatment with topical citric acid and sodium nitrite, 9 of 15 wounds (60%) and 3 of 8 patients (37%) were cleared of infection. MRSA isolates from these patients were all sensitive to acidified nitrite in vitro compared to methicillin-sensitive S. aureus and a reference strain of MRSA. Conclusions Nitric oxide and acidified nitrite offer a novel therapy for control of MRSA in wounds. Wounds that were not cleared of infection may have been re-contaminated or the bioavailability of acidified nitrite impaired by local factors in the tissue

Repeated, Selection-Driven Genome Reduction of Accessory Genes in Experimental Populations

Genome reduction has been observed in many bacterial lineages that have adapted to specialized environments. The extreme genome degradation seen for obligate pathogens and symbionts appears to be dominated by genetic drift. In contrast, for free-living organisms with reduced genomes, the dominant force is proposed to be direct selection for smaller, streamlined genomes. Most variation in gene content for these free-living species is of “accessory” genes, which are commonly gained as large chromosomal islands that are adaptive for specialized traits such as pathogenicity. It is generally unclear, however, whether the process of accessory gene loss is largely driven by drift or selection. Here we demonstrate that selection for gene loss, and not a shortened genome, per se, drove massive, rapid reduction of accessory genes. In just 1,500 generations of experimental evolution, 80% of populations of Methylobacterium extorquens AM1 experienced nearly parallel deletions removing up to 10% of the genome from a megaplasmid present in this strain. The absence of these deletion events in a mutation accumulation experiment suggested that selection, rather than drift, has dominated the process. Reconstructing these deletions confirmed that they were beneficial in their selective regimes, but led to decreased performance in alternative environments. These results indicate that selection can be crucial in eliminating unnecessary genes during the early stages of adaptation to a specialized environment

Prediction of cervical intraepithelial neoplasia grade 2+ (CIN2+) using HPV DNA testing after a diagnosis of atypical squamous cell of undetermined significance (ASC-US) in Catalonia, Spain

<p>Abstract</p> <p>Background</p> <p>A protocol for cervical cancer screening among sexually active women 25 to 65 years of age was introduced in 2006 in Catalonia, Spain to increase coverage and to recommend a 3-year-interval between screening cytology. In addition, Human Papillomavirus (HPV) was offered as a triage test for women with a diagnosis of atypical squamous cells of undetermined significance (ASC-US). HPV testing was recommended within 3 months of ASC-US diagnosis. According to protocol, HPV negative women were referred to regular screening including a cytological exam every 3 years while HPV positive women were referred to colposcopy and closer follow-up. We evaluated the implementation of the protocol and the prediction of HPV testing as a triage tool for cervical intraepithelial lesions grade two or worse (CIN2+) in women with a cytological diagnosis of ASC-US.</p> <p>Methods</p> <p>During 2007-08 a total of 611 women from five reference laboratories in Catalonia with a novel diagnosis of ASC-US were referred for high risk HPV (hrHPV) triage using high risk Hybrid Capture version 2. Using routine record linkage data, women were followed for 3 years to evaluate hrHPV testing efficacy for predicting CIN2+ cases. Logistic regression analysis was used to estimate the odds ratio for CIN2 +.</p> <p>Results</p> <p>Among the 611 women diagnosed with ASC-US, 493 (80.7%) had at least one follow-up visit during the study period. hrHPV was detected in 48.3% of the women at study entry (mean age 35.2 years). hrHPV positivity decreased with increasing age from 72.6% among women younger than 25 years to 31.6% in women older than 54 years (<it>p </it>< 0.01).</p> <p>At the end of the 3 years follow-up period, 37 women with a diagnosis of CIN2+ (18 CIN2, 16 CIN3, 2 cancers, and 1 with high squamous intraepithelial lesions -HSIL) were identified and all but one had a hrHPV positive test at study entry. Sensitivity to detect CIN2+ of hrHPV was 97.2% (95%confidence interval (CI) = 85.5-99.9) and specificity was 68.3% (95%CI = 63.1-73.2). The odds ratio for CIN2+ was 45.3 (95% CI: 6.2-333.0), when among ASC-US hrHPV positive women were compared to ASC-US hrHPV negative women.</p> <p>Conclusions</p> <p>Triage of ASC-US with hrHPV testing showed a high sensitivity for the detection of CIN2+ and a high negative predictive value after 3 years of follow-up. The results of this study are in line with the current guidelines for triage of women with ASC-US in the target age range of 25-65. Non adherence to guidelines will lead to unnecessary medical interventions. Further investigation is needed to improve specificity of ASC-US triage.</p

Sequestration and Tissue Accumulation of Human Malaria Parasites: Can We Learn Anything from Rodent Models of Malaria?

The sequestration of Plasmodium falciparum–infected red blood cells (irbcs) in the microvasculature of organs is associated with severe disease; correspondingly, the molecular basis of irbc adherence is an active area of study. In contrast to P. falciparum, much less is known about sequestration in other Plasmodium parasites, including those species that are used as models to study severe malaria. Here, we review the cytoadherence properties of irbcs of the rodent parasite Plasmodium berghei ANKA, where schizonts demonstrate a clear sequestration phenotype. Real-time in vivo imaging of transgenic P. berghei parasites in rodents has revealed a CD36-dependent sequestration in lungs and adipose tissue. In the absence of direct orthologs of the P. falciparum proteins that mediate binding to human CD36, the P. berghei proteins and/or mechanisms of rodent CD36 binding are as yet unknown. In addition to CD36-dependent schizont sequestration, irbcs accumulate during severe disease in different tissues, including the brain. The role of sequestration is discussed in the context of disease as are the general (dis)similarities of P. berghei and P. falciparum sequestration

Sex-Related Differences in Gene Expression in Human Skeletal Muscle

There is sexual dimorphism of skeletal muscle, the most obvious feature being the larger muscle mass of men. The molecular basis for this difference has not been clearly defined. To identify genes that might contribute to the relatively greater muscularity of men, we compared skeletal muscle gene expression profiles of 15 normal men and 15 normal women by using comprehensive oligonucleotide microarrays. Although there were sex-related differences in expression of several hundred genes, very few of the differentially expressed genes have functions that are obvious candidates for explaining the larger muscle mass of men. The men tended to have higher expression of genes encoding mitochondrial proteins, ribosomal proteins, and a few translation initiation factors. The women had >2-fold greater expression than the men (P<0.0001) of two genes that encode proteins in growth factor pathways known to be important in regulating muscle mass: growth factor receptor-bound 10 (GRB10) and activin A receptor IIB (ACVR2B). GRB10 encodes a protein that inhibits insulin-like growth factor-1 (IGF-1) signaling. ACVR2B encodes a myostatin receptor. Quantitative RT-PCR confirmed higher expression of GRB10 and ACVR2B genes in these women. In an independent microarray study of 10 men and 9 women with facioscapulohumeral dystrophy, women had higher expression of GRB10 (2.7-fold, P<0.001) and ACVR2B (1.7-fold, P<0.03). If these sex-related differences in mRNA expression lead to reduced IGF-1 activity and increased myostatin activity, they could contribute to the sex difference in muscle size

Association of Chromosome 9p21 with Subsequent Coronary Heart Disease events:A GENIUS-CHD study of individual participant data

BACKGROUND:Genetic variation at chromosome 9p21 is a recognized risk factor for coronary heart disease (CHD). However, its effect on disease progression and subsequent events is unclear, raising questions about its value for stratification of residual risk. METHODS:A variant at chromosome 9p21 (rs1333049) was tested for association with subsequent events during follow-up in 103,357 Europeans with established CHD at baseline from the GENIUS-CHD Consortium (73.1% male, mean age 62.9 years). The primary outcome, subsequent CHD death or myocardial infarction (CHD death/MI), occurred in 13,040 of the 93,115 participants with available outcome data. Effect estimates were compared to case/control risk obtained from CARDIoGRAMPlusC4D including 47,222 CHD cases and 122,264 controls free of CHD. RESULTS:Meta-analyses revealed no significant association between chromosome 9p21 and the primary outcome of CHD death/MI among those with established CHD at baseline (GENIUS-CHD OR 1.02; 95% CI 0.99-1.05). This contrasted with a strong association in CARDIoGRAMPlusC4D OR 1.20; 95% CI 1.18-1.22; p for interaction Conclusions: In contrast to studies comparing individuals with CHD to disease free controls, we found no clear association between genetic variation at chromosome 9p21 and risk of subsequent acute CHD events when all individuals had CHD at baseline. However, the association with subsequent revascularization may support the postulated mechanism of chromosome 9p21 for promoting atheroma development

Approaches in biotechnological applications of natural polymers

Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)

Enhancement of antimicrobial activities of whole and sub-fractionated white tea by addition of copper (II) sulphate and vitamin C against 'Staphylococcus aureus'; a mechanistic approach.

WT showed no efficacy in the combinations tested. WTF was enhanced with copper (II) sulphate and further with vitamin C. WT and WTF increased acidity of copper (II) sulphate possibly via the formation of chemical complexes. The difference in WT/WTF absorbance possibly represented substances less concentrated or absent in WTF. Investigations to establish which WTF component/s and in what proportions additives are most effective against target organisms are warranted