Comparative genomic indexing reveals the phylogenomics of Escherichia coli pathogens

The Escherichia coli O26 serogroup includes important food-borne pathogens associated with human and animal diarrheal disease. Current typing methods have revealed great genetic heterogeneity within the O26 group; the data are often inconsistent and focus only on verotoxin (VT)-positive O26 isolates. To improve current understanding of diversity within this serogroup, the genomic relatedness of VT-positive and -negative O26 strains was assessed by comparative genomic indexing. Our results clearly demonstrate that irrespective of virulence characteristics and pathotype designation, the O26 strains show greater genomic similarity to each other than to any other strain included in this study. Our data suggest that enteropathogenic and VT-expressing E. coli O26 strains represent the same clonal lineage and that VT-expressing E. coli O26 strains have gained additional virulence characteristics. Using this approach, we established the core genes which are central to the E. coli species and identified regions of variation from the E. coli K-12 chromosomal backbone.     

Expression of inducible nitric oxide synthase in skin lesions of patients with american cutaneous leishmaniasis

Cytokine-inducible (or type 2) nitric oxide synthase (iNOS) is indispensable for the resolution of Leishmania major or Leishmania donovani infections in mice. In contrast, little is known about the expression and function of iNOS in human leishmaniasis. Here, we show by immunohistological analysis of skin biopsies from Mexican patients with local (LCL) or diffuse (DCL) cutaneous leishmaniasis that the expression of iNOS was most prominent in LCL lesions with small numbers of parasites whereas lesions with a high parasite burden (LCL or DCL) contained considerably fewer iNOS-positive cells. This is the first study to suggest an antileishmanial function of iNOS in human Leishmania infections in vivo.     

Loss of p16 (INK4A) expression is associated with allelic imbalance/loss of heterozygosity of chromosome 9p21 in microdissected malignant peripheral nerve sheath tumors.

The p16 is a tumor suppressor gene on the short arm of chromosome 9p21. The product of the p16 acts as a negative cell cycle regulator by inhibiting G1 cyclin-dependent kinases that phosphorylate the retinoblastoma protein. This study was designed to assess the frequency of genetic loss of 9p21 and to determine the role of p16 the pathogenesis of sporadic and neurofibromatosis 1 (NF1)-associated malignant peripheral nerve sheath tumors (MPNSTs). The authors examined 15 cases for p16 protein expression and 10 cases for allelic imbalance (AI)/loss of heterozygosity (LOH) of chromosome 9p. DNA was microdissected from normal and neoplastic tissues. AI/LOH analysis was performed using six microsatellite markers on the 9p region. On immunohistochemical analysis 80% of cases showed abnormal expression of p16. Similarly, 8 of 10 cases revealed genetic loss with at least one microsatellite marker. The most frequent deletion was that within the coding sequence. Of p16 at me D9S974 locus. These findings emphasize the role of loss of p16 in the development of both sporadic and NF1-associated MPNSTs.     

Neurotoxicity induced by lead levels: an electrophysiological study

The object of the present study was to evaluate, with the aid of visual evoked potentials (VEPs), modifications induced in the optic nerve by lead, and to investigate the relationship between blood lead levels (PbB) and modification of the VEP. We studied a sample of 300 men with PbB values between 17 and 60 g/100 ml. Our study demonstrates that alterations in the latency of the VEP are dependent on PbB levels, though there is not a directly proportional relationship.     

Investigation of Solid Dosage Form Components Interaction Using Orthogonal Techniques- Discovery of New Forms of Sodium Stearyl Fumarate

Physical or chemical interactions between drug product (DP) components can occur during manufacturing and/or upon storage; and may alter DP shelf life and performance. In this work a new Powder X-ray Diffraction (PXRD) peak was observed in DP under accelerated storage conditions. Due to the complex drug product matrix (including API, polymer, fillers, super disintegrant and lubricant), it was challenging to pinpoint the component(s) responsible for the new peak. In addition to PXRD, other orthogonal techniques including Differential Scanning Calorimetry (DSC), thermogravimetric analysis (TGA), dynamic vapor sorption (DVS), Solid State Nuclear Magnetic Resonance (SSNMR) and Infrared (IR) spectroscopy were employed in this investigation to understand the root cause mechanistically. Specifically, multi nuclei SSNMR (¹H, ²³Na, ¹³C) was instrumental in delineating the components of the matrix. We identified the root cause to be an acid base reaction occurring in the DP, whereby sodium ion in sodium stearyl fumarate (SSF) is replaced by proton leading to SSF form conversion. We also identified commercially available SSF to be a hydrate that can dehydrate to an anhydrous form upon heating. In general, the same techniques can be used to investigate interactions of any multi component solid dosage forms.     

Home diagnostic tests in the state of Qatar: a snapshot of public views, level of awareness and use

Background In Qatar, home diagnostic tests are available over the counter in community pharmacies. While possibly beneficial, these tests have the potential for harm if they are used in the absence of pharmacist counseling. Objectives To determine the public views, level of awareness and use of home diagnostic tests and to evaluate the extent of community pharmacists?? involvement in educating the public about these tests in Qatar. Setting Qatar??s Supreme Council of Health lists 245 community pharmacies in Qatar. Ten community pharmacies were randomly selected from the list as study sites. Method The investigators visited selected pharmacies on different weekdays and at different times of the day. Members of the public who appeared to be over 16?years of age and able to communicate in English or Arabic were randomly approached, provided with the study objectives, and requested to participate. Those who offered oral consent were anonymously interviewed using a multipart survey. Main outcome measures Measures include the public awareness and use of home diagnostic tests and the extent of community pharmacist involvement in educating the public about these tests. Results During the 5-month study period, 297 patients answered the survey (60?% response rate). Most respondents were aware of at least one home diagnostic test (98?%). The top four home diagnostic tests that the respondents had ever heard of included: thermometers (91?%), blood pressure monitors (91?%), blood sugar tests (86?%) and regular pregnancy tests (72?%). Seventy-one percent of respondents had performed at least one home diagnostic test. When asked about the factors that influenced their choice of the home diagnostic tests, the pharmacist was only cited by 7?% of respondents. The majority of respondents (>80?%) agreed that using a home diagnostic test is convenient, comfortable and helps them in early diagnosis and treatment of healthcare conditions. Only 31?% agreed that the pharmacist offered sufficient information on what to do in case the test result turns to be positive. The study results suggest that generally, the public has good attitudes and awareness of home diagnostic tests. However, the results indicate that Qatar community pharmacists are not sufficiently involved in public education about home diagnostic tests. Pharmacists should take a more active role in counseling the public on the proper use of these tests.     

Clinicopathological analysis of papillary thyroid cancer with PIK3CA alterations in a Middle Eastern population

CONTEXT: Genetic aberration in phosphatidylinositol 3-kinase (PI3K)/AKT pathway has been detected in numerous and diverse human cancers. PIK3CA, which encodes for the catalytic subunit of p110alpha of PI3K, is amplified in some cases of papillary thyroid cancer (PTC). Mutations in the PIK3CA have also been identified in thyroid cancers and, although relatively common in anaplastic thyroid carcinoma, are uncommon in PTC. OBJECTIVE: The objective of the study was to investigate genetic alterations like PIK3CA gene mutation, PIK3CA amplification, RAS, and RAF mutations and to further explore the relationship of these genetic alterations with various clinicopathological characteristics in Middle Eastern PTC. DESIGN: We used the fluorescence in situ hybridization technique for analysis of PIK3CA amplification from 536 PTC cases, and selected amplified samples were further validated by real-time quantitative PCR. Mutation analysis was done by direct DNA sequencing of PIK3CA, N2-RAS, and BRAF genes. RESULTS: PIK3CA amplification was seen in 265 of 499 PTC cases analyzed (53.1%); PIK3CA gene mutations in four of 207 PTC (1.9%); N2-RAS mutations in 16 of 265 PTC (6%); and BRAF mutations in 153 of 296 PTC (51.7%). N-RAS mutations were-associated with an early stage (P = 0.0465) and lower incidence of extrathyroidal extension (P = 0.027), whereas BRAF mutations were-associated with metastasis (P = 0.0274) and poor disease-free survival (P = 0.0121) in PTCs. CONCLUSION: A higher incidence of PIK3CA alterations and the possible synergistic effect of PIK3CA alterations and BRAF mutations suggest their major role in Middle Eastern PTC tumorigenesis and argue for therapeutic targeting of PI3K/AKT and MAPK pathways.