Numerical study of hemodynamics in brain aneurysms treated with flow diverter stents using porous medium theory

Conventional approaches of implementing computational fluid dynamics to study aneurysmal hemodynamics after treatment with a flow diverter stent are computationally expensive. Cumbersome meshing and lengthy simulation runtimes are common. To address these issues, we present a novel volume penalization method that considers flow diverters as heterogeneous porous media. The proposed model requires a considerably smaller number of mesh elements, leading to faster simulation runtimes. Three patient-specific aneurysms were virtually treated with flow diverters and aneurysmal hemodynamics were simulated. The results of the virtual deployments including aneurysmal hemodynamics were compared to corresponding results from conventional approaches. The comparisons showed that the proposed approach led to 9.12 times increase in the speed of simulations on average. Further, aneurysmal kinetic energy and inflow rate metrics for the proposed approach were consistent with those from conventional approaches, differing on average by 3.52% and 3.78%, respectively.     

Diabetes mellitus and its correlates in an Iranian adult population

The rising epidemic of diabetes imposes a substantial economic burden on the Middle East. Using baseline data from a population based cohort study, we aimed to identify the correlates of diabetes mellitus (DM) in a mainly rural population from Iran. Between 2004 and 2007, 50044 adults between 30 and 87 years old from Golestan Province located in Northeast Iran were enrolled in the Golestan Cohort Study. Demographic and health-related information was collected using questionnaires. Individuals' body sizes at ages 15 and 30 were assessed by validated pictograms ranging from 1 (very lean) to 7 in men and 9 in women. DM diagnosis was based on the self-report of a physician's diagnosis. The accuracy of self-reported DM was evaluated in a subcohort of 3811 individuals using fasting plasma glucose level and medical records. Poisson regression with robust variance estimator was used to estimate prevalence ratios (PR's). The prevalence of self-reported DM standardized to the national and world population was 5.7% and 6.2%, respectively. Self-reported DM had 61.5% sensitivity and 97.6% specificity. Socioeconomic status was inversely associated with DM prevalence. Green tea and opium consumption increased the prevalence of DM. Obesity at all ages and extreme leanness in childhood increased diabetes prevalence. Being obese throughout life doubled DM prevalence in women (PR: 2.1; 95% CI: 1.8, 2.4). These findings emphasize the importance of improving DM awareness, improving general living conditions, and early lifestyle modifications in diabetes prevention.     

Pollen morphology of selected species of Allium (Alliaceae) distributed in Iran

Pollen morphology of 19 species of Allium representing six subgenera and 12 sections, were studied. The following characters were recognized as important for separating taxa at different taxonomic ranks: the sulcus, presence or absence of perforations on the pollen surface, density of perforations, size of perforations and size of the pollen grains. Rugulate, rugulate–striate, and simple–perforate exine ornamentation were distinguished. The type of sulcus is very characteristic in A. subgen. Allium sect. Allium . The extended sulcus was not observed in any species the other sections of subgen. Allium studied here, such as sect. Caerulea ( A. capitellatum ), sect. Codonprasum ( A. lenkoranicum and A. stamineum ) and sect. Avulsea ( A. rubellum and A. umblicatum ). Imperforated pollen grains were observed in representatives of A. subgen. Reticulatobulbosa and subgen. Polyprason .     

Metabolic Syndrome Is Linked to Chromosome 7q21 and Associated With Genetic Variants in CD36 and GNAT3 in Mexican Americans

The prevalence of metabolic syndrome (MS) has been rising alarmingly worldwide, including in the United States, but knowledge on specific genetic determinants of MS is very limited. Therefore, we planned to identify the genetic determinants of MS as defined by National Cholesterol Education Program/Adult Treatment Panel III (NCEP/ATPIII) criteria. We performed linkage screen for MS using data from 692 Mexican Americans, who participated in the San Antonio Family Diabetes/Gallbladder Study (SAFDGS). We found strong evidence for linkage of MS on chromosome 7q (LOD = 3.6, empirical P = 6.0 × 10(-5)), between markers D7S2212 and D7S821. In addition, six chromosomal regions exhibited potential evidence for linkage (LOD ≥1.2) with MS. Furthermore, we examined 29 single-nucleotide polymorphisms (SNPs) from the fatty acid translocase (FAT or CD36, 18 SNPs) gene and guanine nucleotide binding protein, α transducing 3 (GNAT3, 11 SNPs) gene, located within the 1-LOD support interval region for their association with MS and its related traits. Several SNPs were associated with MS and its related traits. Remarkably, rs11760281 in GNAT3 and rs1194197 near CD36 exhibited the strongest associations with MS (P = 0.0003, relative risk (RR) = 1.6 and P = 0.004, RR = 1.7, respectively) and several other related traits. These two variants explained ~18% of the MS linkage evidence on chromosome 7q21, and together conferred approximately threefold increase in MS risk (RR = 2.7). In conclusion, our linkage and subsequent association studies implicate a region on chromosome 7q21 to influence MS in Mexican Americans.     

The prevalence of molecular and immunologic infective markers of hepatitis viruses in patients with hematological malignancies

Acute and chronic viral hepatitis infections are corresponding to increase the risk of different types of hematological malignancies especially with leukemia. In this study the serological and molecular markers of hepatitis viruses were evaluated in patients with different types of leukemia in comparing with control group. In this cross sectional study, 100 EDTA-treated blood samples were collected from leukemia patients and also from healthy control group, respectively. Serological and molecular markers of HBV, HCV and HDV viruses were analyzed for determination of the role of these hepatitis viruses in clinical outcomes of leukemia disorders. Increasing risk factors of leukemia were evaluated statistically in two studied groups by SPSS software. One of molecular and immunological markers of HBV, HDV and HCV was found in 24 of 100 (24%), 22 of 100 (22%), and 1 of 100 (1%) patients with leukemia and in 12 of 100 (12%), 6 of 100 (6%), and 2 of 100 (2%) control patients. Significant differences were detected in detection of HBsAg (P = 0.02), HBeAb (P = 0.009), and HCV-RNA (P = 0.05) between leukemia patients and control group, respectively. The high prevalence of HBV and HCV infective markers were detected in ALL and AML patients. Identification of high prevalence of HBV and HCV infective markers in leukemia patients proposed strong association between hepatitis viral infections and leukemia. Therefore, evaluation of the prevalence of viral hepatitis infections in larger groups of patients with long lasting follow up is suggesting.     

The Zymovars of Vibrio cholerae: multilocus enzyme electrophoresis of Vibrio cholerae

Zymovars analysis also known as multilocus enzyme electrophoresis is applied here to investigate the genetic variation of Vibrio cholerae strains and characterise strains or group of strains of medical and epidemiological interest. Fourteen loci were analyzed in 171 strains of non-O1 non-O139, 32 classical and 61 El Tor from America, Africa, Europe and Asia. The mean genetic diversity was 0.339. It is shown that the same O antigen (both O1 and non-O1) may be present in several genetically diverse (different zymovars) strains. Conversely the same zymovar may contain more than one serogroup. It is confirmed that the South American epidemic strain differs from the 7th pandemic El Tor strain in locus LAP (leucyl leucyl aminopeptidase). Here it is shown that this rare allele is present in 1 V. mimicus and 4 non-O1 V. cholerae. Non toxigenic O1 strains from South India epidemic share zymovar 14A with the epidemic El Tor from the 7th pandemic, while another group have diverse zymovars. The sucrose negative epidemic strains isolated in French Guiana and Brazil have the same zymovar of the current American epidemic V. cholerae.     

5-lipoxygenase and atherosclerosis

PURPOSE OF REVIEW: 5-Lipoxygenase (5LO) was recently identified as a gene that makes an important contribution to atherosclerosis in mice and humans, but the underlying mechanism(s) remains unknown. RECENT FINDINGS: Studies of the 5LO pathway in other disease areas suggest that 5LO could contribute to atherosclerosis at different levels, such as lesion initiation, growth and cellular proliferation within the lesion, and/or destabilization of plaques that can lead to their rupture. SUMMARY: Recent advances in our understanding of how 5LO is involved in the atherosclerotic process will have important implications for diagnostic and therapeutic strategies in the future.     

An astrocytic basis of epilepsy

Hypersynchronous neuronal firing is a hallmark of epilepsy, but the mechanisms underlying simultaneous activation of multiple neurons remains unknown. Epileptic discharges are in part initiated by a local depolarization shift that drives groups of neurons into synchronous bursting. In an attempt to define the cellular basis for hypersynchronous bursting activity, we studied the occurrence of paroxysmal depolarization shifts after suppressing synaptic activity using tetrodotoxin (TTX) and voltage-gated Ca(2+) channel blockers. Here we report that paroxysmal depolarization shifts can be initiated by release of glutamate from extrasynaptic sources or by photolysis of caged Ca(2+) in astrocytes. Two-photon imaging of live exposed cortex showed that several antiepileptic agents, including valproate, gabapentin and phenytoin, reduced the ability of astrocytes to transmit Ca(2+) signaling. Our results show an unanticipated key role for astrocytes in seizure activity. As such, these findings identify astrocytes as a proximal target for the treatment of epileptic disorders.     

A new locus for autosomal dominant amelogenesis imperfecta on chromosome 8q24.3

Amelogenesis imperfecta (AI) is a collective term used to describe phenotypically diverse forms of defective tooth enamel development. AI has been reported to exhibit a variety of inheritance patterns, and several loci have been identified that are associated with AI. We have performed a genome-wide scan in a large Brazilian family segregating an autosomal dominant form of AI and mapped a novel locus to 8q24.3. A maximum multipoint LOD score of 7.5 was obtained at marker D8S2334 (146,101,309 bp). The disease locus lies in a 1.9 cM (2.1 Mb) region according to the Rutgers Combined Linkage-Physical map, between a VNTR marker (at 143,988,705 bp) and the telomere (146,274,826 bp). Ten candidate genes were identified based on gene ontology and microarray-facilitated gene selection using the expression of murine orthologues in dental tissue, and examined for the presence of a mutation. However, no causative mutation was identified.     

Synthesis, antibacterial activity, and quantitative structure-activity relationships of new (Z)-2-(nitroimidazolylmethylene)-3(2H)-benzofuranone derivatives

A new series of (Z)-2-(1-methyl-5-nitroimidazole-2-ylmethylene)-3(2H)-benzofuranones (11a-p) and (Z)-2-(1-methyl-4-nitroimidazole-5-ylmethylene)-3(2H)-benzofuranones (12a-m) were synthesized and assayed for their antibacterial activity against Gram-positive and Gram-negative bacteria. Most of the 5-nitroimidazole analogues (11a-p) showed a remarkable inhibition of a wide spectrum of Gram-positive bacteria (Staphylococcus aureus, Streptococcus epidermidis, MRSA, and Bacillus subtilis) and Gram-negative Klebsiella pneumoniae, whereas 4-nitroimidazole analogues (12a-m) were not effective against selected bacteria. The quantitative structure-activity relationship investigations were applied to find out the correlation between the experimentally evaluated activities with various parameters of the compounds studied. The QSAR models built in this work had reasonable predictive power and could be explained by the observed trends in activities.