Exploring the links between SOS response, mutagenesis, and resistance during the recovery period.

Although the mechanistic connections between SOS-induced mutagenesis and antibiotic resistance are well established, our current understanding of the impact of SOS response levels, recovery durations, and transcription/translation activities on mutagenesis remains relatively limited. In this study, when bacterial cells were exposed to mutagens like ultraviolet light for defined time intervals, a compelling connection between the rate of mutagenesis and the RecA-mediated SOS response levels became evident. Our observations also indicate that mutagenesis primarily occurs during the subsequent recovery phase following the removal of the mutagenic agent. When transcription/translation was inhibited or energy molecules were depleted at the onset of treatment or during the early recovery phase, there was a noticeable decrease in SOS response activation and mutagenesis. However, targeting these processes later in the recovery phase does not have the same effect in reducing mutagenesis, suggesting that the timing of inhibiting transcription/translation or depleting energy molecules is crucial for their efficacy in reducing mutagenesis. Active transcription, translation, and energy availability within the framework of SOS response and DNA repair mechanisms appear to be conserved attributes, supported by their consistent manifestation across diverse conditions, including the use of distinct mutagens such as fluoroquinolones and various bacterial strains.

Systematic design of pulse dosing to eradicate persister bacteria.

A small fraction of infectious bacteria use persistence as a strategy to survive exposure to antibiotics. Periodic pulse dosing of antibiotics has long been considered a potentially effective strategy towards eradication of persisters. Recent studies have demonstrated through in vitro experiments that it is indeed feasible to achieve such effectiveness. However, systematic design of periodic pulse dosing regimens to treat persisters is currently lacking. Here we rigorously develop a methodology for the systematic design of optimal periodic pulse dosing strategies for rapid eradication of persisters. A key outcome of the theoretical analysis, on which the proposed methodology is based, is that bactericidal effectiveness of periodic pulse dosing depends mainly on the ratio of durations of the corresponding on and off parts of the pulse. Simple formulas for critical and optimal values of this ratio are derived. The proposed methodology is supported by computer simulations and in vitro experiments.

Co-Expression of type 1 fimbriae and flagella in Escherichia coli: consequences for adhesion at interfaces.

Escherichia coli expresses surface appendages including fimbriae, flagella, and curli, at various levels in response to environmental conditions and external stimuli. Previous studies have revealed an interplay between expression of fimbriae and flagella in several E. coli strains, but how this regulation between fimbrial and flagellar expression affects adhesion to interfaces is incompletely understood. Here, we investigate how the concurrent expression of fimbriae and flagella by engineered strains of E. coli MG1655 affects their adhesion at liquid-solid and liquid-liquid interfaces. We tune fimbrial and flagellar expression on the cell surface through plasmid-based inducible expression of the fim operon and fliC-flhDC genes. We show that increased fimbrial expression increases interfacial adhesion as well as bacteria-driven actuation of micron-sized objects. Co-expression of flagella in fimbriated bacteria, however, does not greatly affect either of these properties. Together, these results suggest that interfacial adhesion as well as motion actuated by adherent bacteria can be altered by controlling the expression of surface appendages.

Suppression of amyloid-ß fibril growth by drug-engineered polymorph transformation.

Fibrillization of the protein amyloid ß is assumed to trigger Alzheimer's pathology. Approaches that target amyloid plaques, however, have garnered limited clinical success, and their failures may relate to the scarce understanding of the impact of potential drugs on the intertwined stages of fibrillization. Here, we demonstrate that bexarotene, a T-cell lymphoma medication with known antiamyloid activity both in vitro and in vivo, suppresses amyloid fibrillization by promoting an alternative fibril structure. We employ time-resolved in situ atomic force microscopy to quantify the kinetics of growth of individual fibrils and supplement it with structure characterization by cryo-EM. We show that fibrils with structure engineered by the drug nucleate and grow substantially slower than "normal" fibrils; remarkably, growth remains stunted even in drug-free solutions. We find that the suppression of fibril growth by bexarotene is not because of the drug binding to the fibril tips or to the peptides in the solution. Kinetic analyses attribute the slow growth of drug-enforced fibril polymorph to the distinctive dynamics of peptide chain association to their tips. As an additional benefit, the bexarotene fibrils kill primary rat hippocampal neurons less efficiently than normal fibrils. In conclusion, the suggested drug-driven polymorph transformation presents a mode of action to irreversibly suppress toxic aggregates not only in Alzheimer's but also potentially in myriad diverse pathologies that originate with protein condensation.

Expression of Toll-Like Receptors in the Lung Tissue of Mouse Fetuses Generated by in vitro Embryo Culture and Embryo Transfer.

Mouse fetuses generated by in vitro embryo culture and embryo transfer exhibit impaired lung development, altered composition of pulmonary epithelial cells associated with downregulation of several genes involved in lung development and toll-like receptor (TLR) signaling pathway. The aims of the present study were to determine the expression of all TLRs and to examine if the expression of TLRs, along with genes involved in TLR signaling pathway, is altered in the lung tissue of mouse fetuses generated through embryo culture and embryo transfer. Two experimental (EGs) and one control (CG) group were included in the study. Embryos cultured at 5% CO2-95% air for 95 h or less than 24 h were transferred to pseudo-pregnant females to obtain fetuses comprising EGin vitro (n = 18) and EGin vivo (n = 18), respectively. Fetuses obtained from naturally ovulating females on day 18 of pregnancy served as the CG (n = 18). Western blot and immunohistochemistry were used to determine the expression of TLR proteins. The expression of transcripts encoding TLRs, and the genes involved in TLR signaling pathway (Lbp, Pik3r1, Pik3cb, Nfkbia, and Fos), was determined using qRT-PCR. While all TLRs were expressed by cells lining the bronchial/bronchiolar epithelium of lung tissues in all groups, some of the TLRs were expressed in a specific pattern. When compared to CG, the expression of transcripts encoding TLR-2, -3, -4, -5, -7, -8, -9, -12, -13, Lbp, Pik3r1, Pik3cb, Nfkbia, and Fos was significantly downregulated in both EGs. It appears that stress imposed on embryos at preimplantation stages of development is associated with downregulation of TLRs, along with some of the genes involved in TLR signaling pathway, in the lung tissue during the perinatal period. It remains to be determined if downregulation of TLRs, along with the genes involved in TLR signaling pathway, has any functional consequences in the adult lung tissue.

Associations Between Neuroanatomic Patterns of Cerebral Infarctions and Vascular Dementia.

OBJECTIVE: A history of multiple cerebral infarctions is generally regarded as an important risk factor for vascular dementia. The authors examined the risk of vascular dementia in patients with multiple acute ischemic lesions. METHODS: The authors conducted a hospital-based prospective study of 11,200 patients with first-time stroke who underwent 1.5 or 3-T MRI and a global cognitive assessment. Univariate and multivariate logistic regression analyses estimated the risk of dementia associated with multiple lesions versus a single lesion. RESULTS: Having multiple lesions, compared with having a single lesion, was significantly associated with dementia in patients with stroke (odds ratio=5.83, 95% CI=5.08, 6.70; p<0.001). The apoliproprotein ε4 allele was more frequent in patients with multiple lesions than in those with a single lesion (odds ratio=1.70, 95% CI=1.39, 2.07; p<0.001). Severe leukoaraiosis (odds ratio=15.77, 95% CI=8.38, 29.68; p<0.001) and microbleedings (odds ratio=1.31, 95% CI=1.06, 1.63; p<0.01) were strong confounders for dementia in the multivariate analysis. Multiple logistic regression analysis showed that multiple lesions in one hemisphere versus a single lesion (odds ratio=2.14, 95% CI=1.83, 2.51; p<0.001), involvement of strategic regions (odds ratio=4.73, 95% CI=4.07, 5.49; p<0.001), and stroke lesion volume (odds ratio=1.31, 95% CI=1.03, 1.66; p=0.03) were significantly associated with dementia. There was a preponderance of lesions on the left side in patients with dementia (odds ratio=2.56, 95% CI=2.11, 3.11; p<0.001). CONCLUSIONS: Multiple spontaneous anterior or posterior circulation lesions after stroke increase a patient's risk of developing dementia. Recognition of multiple ischemic lesions after stroke may allow targeted rapid therapeutic interventions to prevent subsequent cognitive deterioration.

Metabolic control of persister formation in Escherichia coli.

Bacterial persisters are phenotypic variants that form from the action of stress response pathways triggering toxin-mediated antibiotic tolerance. Although persisters form during normal growth from native stresses, the pathways responsible for this phenomenon remain elusive. Here we have discovered that carbon source transitions stimulate the formation of fluoroquinolone persisters in Escherichia coli. Further, through a combination of genetic, biochemical, and flow cytometric assays in conjunction with a mathematical model, we have reconstructed a molecular-level persister formation pathway from initial stress (glucose exhaustion) to the activation of a metabolic toxin-antitoxin (TA) module (the ppGpp biochemical network) resulting in inhibition of DNA gyrase activity, the primary target of fluoroquinolones. This pathway spans from initial stress to antibiotic target and demonstrates that TA behavior can be exhibited by a metabolite-enzyme interaction (ppGpp-SpoT), in contrast to classical TA systems that involve only protein and/or RNA.

Validation of the NoSAS score for screening sleep-disordered breathing: A sleep clinic- based study in Turkey

Background/aim: The NoSAS score is a new tool for the identification of high-risk patients for sleep-disordered breathing (SDB). The aim of this study was to validate the NoSAS score in a sleep clinical population in Turkey and compare its performance with the Epworth Sleepiness Scale (ESS), STOP-Bang, and Berlin questionnaires for high-risk SDB. Materials and methods: This was a retrospective study. Patients who had a full-night PSG examination between 01.03.2017 and 01.01.2018 at the sleep center of our hospital were included in the study. Demographic characteristics, anthropometrics measurements, ESS, STOP-Bang, and Berlin scores were collected from the existing data of the patients. The NoSAS score was subsequently calculated based on available data. Predictive parameters for each screening questionnaires were calculated to compare the discriminative power of those for high-risk SDB. Results: A total of 450 patients were included in the study. The sensitivity, specificity, PPV, and NPV of the NoSAS score were 81%, 51.2%, 88.2%, and 37.5% for an AHI (apnea­hypopnea index) ≥ 5 event/h and 84.5%, 38.2%, 66%, and 63.4% for an AHI ≥ 15 event/h, respectively. AUC percentages for the NoSAS score, STOP-Bang questionnaire, Berlin questionnaire, and ESS were 0.740, 0.737, 0.626, and 0.571 for an AHI ≥ 5 events/h and 0.715, 0.704, 0.574, and 0.621 for an AHI ≥ 30 events/h. The NoSAS score had a false negative rate of 2.9% for severe SDB. Conclusion: The NoSAS score had a good degree of differentiation for SDB and can be used as an easily applicable, subjective, and effective screening tool in a sleep clinical population in Turkey. Not only in moderate to severe SDB but also in mild SDB, the NoSAS score performed better than the other 3 screening tools.

Investigating the Effects of Osmolytes and Environmental pH on Bacterial Persisters.

Bacterial persisters are phenotypic variants that temporarily demonstrate an extraordinary tolerance toward antibiotics. Persisters have been linked to the recalcitrance of biofilm-related infections; hence, a complete understanding of their physiology can lead to improvement of therapeutic strategies for such infections. Mechanisms pertaining to persister formation are thought to be associated with stress response pathways triggered by intra- or extracellular stress factors. Unfortunately, studies demonstrating the effects of osmolyte- and/or pH-induced stresses on bacterial persistence are largely missing. To fill this knowledge gap within the field, we studied the effects of various osmolytes and pH conditions on Escherichia coli persistence with the use of phenotype microarrays and antibiotic tolerance assays. Although we found that a number of chemicals and pH environments, including urea, sodium nitrite, and acidic pH, significantly reduced persister formation in E. coli compared to no-osmolyte/no-buffer controls, this reduction in persister levels was less pronounced in late-stationary-phase cultures. Our results further demonstrated a positive correlation between cell growth and persister formation, which challenges the general notion in the field that slow-growing cultures have more persister cells than fast-growing cultures.

Flow-cytometry analysis reveals persister resuscitation characteristics.

BACKGROUND: Persisters and viable but non-culturable (VBNC) cells are two phenotypic variants known to be highly tolerant to antibiotics. Although both cell types are stained as live and often appear as nongrowing during antibiotic treatment, the only distinguishing feature is the ability of persisters to recolonize in standard culture media in the absence of antibiotics. Despite considerable progress in the characterization of persister formation mechanisms, their resuscitation mechanisms remain unclear due to technical limitations in detecting and isolating these cell types in culture environments that are highly heterogeneous. RESULTS: In this study, we used a methodology integrating flow cytometry, fluorescent protein expression systems and ampicillin-mediated cell lysing technique to monitor persister resuscitation at the single-cell level. With this method, we were able to investigate the effects of various culture conditions (e.g., antibiotic treatment time, the length of the stationary phase in overnight pre-cultures, or pretreatment of cells with a metabolic inhibitor) on persister resuscitation. Although we observed long-term pre-cultures have many more VBNC cells compared to short-term pre-cultures, only a small fraction of non-lysed cells was able to resuscitate in all conditions tested. Regardless of pre-culturing and ampicillin treatment times, these persister cells started to resuscitate within 1 hour, after they were transferred to fresh liquid media, with the same doubling time that normal cells have. Our analysis further showed that ampicillin was not able to lyse the cells in the presence of arsenate, a metabolic inhibitor commonly used to increase bacterial persistence. However, the removal of arsenate during antibiotic treatment resulted in cell lysis and a reduction in persister levels despite the significant decrease in ATP levels in the cells. CONCLUSIONS: The strategy presented in this study helps us monitor persister resuscitation at the single-cell level, and simultaneously quantify persister, VBNC and dead cell subpopulations in ampicillin-treated cultures. Our results indicate that the characterization of persister resuscitation with flow cytometry will enhance the current molecular-level understanding of persistence and its evolution.

Recognition and clinical implications of high prevalence of migraine in patients with Brugada syndrome and drug-induced type 1 Brugada pattern.

INTRODUCTION: We have previously reported high 1-year prevalence of migraine in patients with atrial arrhythmias associated with DI-type 1 BrP. The present study was designed to determine the lifetime prevalence of migraine in patients with Brugada syndrome (BrS) or drug-induced type 1 Brugada pattern (DI-type 1 BrP) and control group, to investigate the demographic and clinical characteristics, and to identify clinical variables to predict underlying BrS/DI-type 1 BrP among migraineurs. METHODS AND RESULTS: Lifetime prevalence of migraine and migraine characteristics were compared between probands with BrS/DI-type 1 BrP (n = 257) and control group (n = 370). Lifetime prevalence of migraine was 60.7% in patients with BrS/DI-type 1 BrP and 30.3% in control group (p = 3.6 × 10-14 ). On stepwise regression analysis, familial migraine (odds ratio [OR] of 4.4; 95% confidence interval [CI]: 2.0-9.8; p = 1.3 × 10-4 ), vestibular migraine (OR of 5.4; 95% CI: 1.4-21.0); p = .013), migraine with visual aura (OR of 1.8; 95% CI: 1.0-3.4); p = .04) and younger age-at-onset of migraine (OR of 0.95; 95% CI: 0.93-0.98); p = .004) were predictors of underlying BrS/DI-type 1 BrP among migraineurs. Use of anti-migraine drugs classified as "to be avoided" or "preferably avoided" in patients with BrS and several other anti-migraine drugs with potential cardiac INa /ICa channel blocking properties was present in 25.6% and 26.9% of migraineurs with BrS/DI-type 1 BrP, respectively. CONCLUSION: Migraine comorbidity is common in patients with BrS/DI-type 1 BrP. We identify several clinical variables that point to an underlying type-1 BrP among migraineurs, necessitating cautious use of certain anti-migraine drugs.

Predictors of Outcome in Patients with Medullary Hemorrhage.

BACKGROUND: Isolated medullary hemorrhage (MH) is an uncommon presentation of spontaneous intraparenchymal hemorrhage. The relationship between MH and neurological outcome is not well known. This study aims to assess predictive parameters for the outcome of medullary hemorrhage. METHODS: We conducted an extensive search of the literature for cases with spontaneous, isolated MH. The study was conducted according to the statement of Preferred Reporting Items for Systematic Reviews and Meta Analysis (PRISMA). Forty-three cases diagnosed by CT or MRI have been reported in the literature, to which we add three confirmed by MRI. The ventrodorsal size of hemorrhage was taken into account as a parameter of outcome. Early neurologic deterioration (END) was defined as an incremental increase in the National Institutes of Health Stroke Scale score by ≥1 point in motor power, or ≥2 points in the total score within the first week after admission. Modified Rankin Score (mRS) 0-2 was presumed as favorable outcome (FO) and mRS 3-6 score as unfavorable outcome (UO) at discharge and at 3 months after stroke. RESULTS: We enrolled 46 patients, and 17 (37%) patients were diagnosed with END. The cause of medullary hemorrhage was mostly vascular malformations, including cavernous malformation (33%) and arteriovenous malformation (11%). In univariate analyses, neither arteriovenous malformations (OR, 1.04; 95%CI, 0.10-10.53; P = 0.68) nor cavernomas (OR, 1.04; 95%CI, 0.22-4.89; P = 0.62) were associated with UO. Acute respiratory distress syndrome was higher in patients with UO group (44%) compared to those with FO group (16%), but this difference did not reach to a significant level (OR, 4.13; 95%CI, 0.85-20.04; P = 0.09). The diameter of hemorrhage was significantly larger (≥1 cm) in patients with UO compared to those with FO (OR, 16.67; 95%CI, 1.87-148.89; P = 0.003). Three months after stroke, 37 patients (80%) had FO and 9 (19.5%) had UO, and 5 (11%) died. Multiple logistic regression analysis using predetermined variables found to be significant in univariate analyses (END, consciousness disturbance at admission, hemorrhage size, and hypertension) showed that END at stroke onset was significantly associated with UO (OR, 4.97; CI95%, 1.13-21.94; P = 0.03). CONCLUSIONS: These results suggest that the END is a predictor for UO in patients with medullary hemorrhage. The extent of the medullary hemorrhage along the conduction tract may contribute to deterioration.

Transfer of mouse blastocysts exposed to ambient oxygen levels can lead to impaired lung development and redox balance.

In vitro culture under atmospheric oxygen puts embryos under oxidative stress and impairs preimplantation development. However, to what extent this process alters the redox balance in the perinatal period remains largely unknown. The aim of the present study was to examine if the redox balance is altered in the lung tissue of fetuses generated through transfer of mouse embryos exposed to atmospheric oxygen at different stages of development and to determine if this has any effect on lung morphogenesis and gene expression. Two experimental groups (EGs) were generated by transferring in vitro- and in vivo-derived blastocysts to pseudo-pregnant females. In vivo-developed fetuses served as control. Enzymatic/nonenzymatic antioxidants, malondialdehyde (MDA) levels, total antioxidant capacity, stage of lung development and gene expression were evaluated on day 18 of pregnancy. Weight of fetuses was significantly less in both experimental cohorts (ANOVA, P < 0.001 versus control), associated with delayed lung development, higher amounts of MDA (ANOVA, P < 0.001 versus control) and altered expression of several genes in oxidative stress/damage pathways. Evidence gathered in the present study indicates that pre-implantation stress caused by culture under atmospheric oxygen, even for a short period of time, leads to fetal growth restriction, impaired lung development and redox balance along with dysregulation of several genes in oxidative stress response. Absence of an EG in which in vitro embryo culture was performed at 5% oxygen and the use of genetically heterogeneous F2 fetuses are the limitations of the study. In any case, the long-term impact of such dramatic changes in the developmental programming of resulting fetuses warrants further investigations.

Stationary phase persister formation in Escherichia coli can be suppressed by piperacillin and PBP3 inhibition.

BACKGROUND: Persisters are rare phenotypic variants within a bacterial population that are capable of tolerating lethal antibiotic concentrations. Passage through stationary phase is associated with the formation of persisters (type I), and a major physiological response of Escherichia coli during stationary phase is cell wall restructuring. Given the concurrence of these processes, we sought to assess whether perturbation to cell wall synthesis during stationary phase impacts type I persister formation. RESULTS: We tested a panel of cell wall inhibitors and found that piperacillin, which primarily targets penicillin binding protein 3 (PBP3 encoded by ftsI), resulted in a significant reduction in both ß-lactam (ampicillin, carbenicillin) and fluoroquinolone (ofloxacin, ciprofloxacin) persister levels. Further analyses showed that piperacillin exposure through stationary phase resulted in cells with more ATP, DNA, RNA, and protein (including PBPs) than untreated controls; and that their physiology led to more rapid resumption of DNA gyrase supercoiling activity, translation, and cell division upon introduction into fresh media. Previously, PBP3 inhibition had been linked to antibiotic efficacy through the DpiBA two component system; however, piperacillin suppressed persister formation in ΔdpiA to the same extent as it did in wild-type, suggesting that DpiBA is not required for the phenomenon reported here. To test the generality of PBP3 inhibition on persister formation, we expressed FtsI Ser307Ala to genetically inhibit PBP3, and suppression of persister formation was also observed, although not to the same magnitude as that seen for piperacillin treatment. CONCLUSIONS: From these data we conclude that stationary phase PBP3 activity is important to type I persister formation in E. coli.

Coexistence of atrioventricular accessory pathways and drug-induced type 1 Brugada pattern.

BACKGROUND: Atrial arrhythmias, particularly atrioventricular nodal reentrant tachycardia, can coexist with drug-induced type 1 Brugada electrocardiogram (ECG) pattern (DI-Type1-BrP). The present study was designed to determine the prevalence of DI-Type1-BrP in patients with atrioventricular accessory pathways (AV-APs) and to investigate the clinical, electrocardiographic, electrophysiologic, and genetic characteristics of these patients. METHODS: One-hundred twenty-four consecutive cases of AV-APs and 84 controls underwent an ajmaline challenge test to unmask DI-Type1-BrP. Genetic screening and analysis was performed in 55 of the cases (19 with and 36 without DI-Type1-BrP). RESULTS: Patients with AV-APs were significantly more likely than controls to have a Type1-BrP unmasked (16.1 vs 4.8%, P = 0.012). At baseline, patients with DI-Type1-BrP had higher prevalence of chest pain, QR/rSr' pattern in V1 and QRS notching/slurring in V2 and aVL during preexcitation, rSr' pattern in V1 -V2 , and QRS notching/slurring in aVL during orthodromic atrioventricular reentrant tachycardia (AVRT) compared to patients without DI-Type1-BrP. Abnormal QRS configuration (QRS notching/slurring and/or fragmentation) in V2 during preexcitation was present in all patients with DI-Type1 BrP. The prevalence of spontaneous preexcited atrial fibrillation (AF) and history of AF were similar (15% vs 18.3%, P = 0.726) in patients with and without DI-Type1-BrP, respectively. The prevalence of mutations in Brugada-susceptibility genes was higher (36.8% vs 8.3%, P = 0.02) in patients with DI-Type1-BrP compared to patients without DI-Type1-BrP. CONCLUSIONS: DI-Type1-BrP is relatively common in patients with AV-APs. We identify 12-lead ECG characteristics during preexcitation and orthodromic AVRT that point to an underlying type1-BrP, portending an increased probability for development of malignant arrhythmias.

Prevalence and significance of MEFV gene mutations in patients with gouty arthritis.

Gouty arthritis is a chronic erosive autoinflammatory disease. Pyrin has anti-inflammatory effects in the regulation of inflammasome and is encoded by the MEFV gene. The relationship between different rheumatic diseases and the MEFV gene mutations was demonstrated. The aim of this study was to determine the frequency of MEFV gene mutations in patients with gouty arthritis and identify a possible correlation with disease phenotype. Ninety-three patients with gouty arthritis and 102 healthy controls, compatible with age, gender and ethnicity, were included in the study. MEFV gene mutations were investigated by PCR method. Out of 93 patients with gouty arthritis, 36 (38.7 %) showed MEFV gene mutations carriage, whereas 20.6 % in healthy control group. Distribution of mutations identified in patients with gouty arthritis was as; R202Q in 18 (19.3 %), E148Q in 5 (5.4 %), K695R in 4 (4.3 %), M680I in 2 (2.1 %), V726A in 2 (2.1 %), P369S in 2 (2.1 %), R408Q in 2 (2.1 %), M694 V in 1 (1.1 %), respectively. Three patients were identified with compound heterozygosity. Distribution of MEFV gene mutations carriage in healthy controls was; E148Q in 11 (10.7 %), M694 V in 2 (1.9 %), M694I in 1 (0.9 %), M680I in 2 (1.9 %), V726A in 1 (0.9 %), A744S in 1 (0.9 %), K695R in 2 (1.9 %), and P369S in 1 (0.9 %) patients, respectively. Higher MEFV gene mutations carrier frequency was observed in patients with gouty arthritis, compared with the control group (p = 0.009). Heterozygous R202Q was the most common mutation detected in patients with gouty arthritis, while heterozygous E148Q in healthy control group. Statistically significant difference was not detected between clinical findings of gouty arthritis and the MEFV gene mutations (p > 0.05). We determined higher prevalence of MEFV gene mutations in patients with gouty arthritis compared with the healthy control group. The most frequently detected mutation was heterozygous R202Q, whereas E148Q in healthy controls. High carriage rates of MEFV gene mutations in gouty arthritis suggest that it may play an important role in the pathogenesis of the disease and predisposition to the disease.

Association of Hyperhomocysteinemia with Stroke Recurrence after Initial Stroke.

BACKGROUND AND PURPOSE: Homocysteine (Hcy) is closely associated with stroke. Despite the fact that Hcy has consistently been shown to predict development of recurrent stroke, prior studies on the association of Hcy and stroke subtypes have been inconclusive. METHODS: Data from the Ege Stroke Registry were examined and 5-year follow-up data were analyzed. Multivariate survival analyses were undertaken using Cox proportional hazards models to determine the prognostic value of Hcy in different ischemic stroke subtypes. RESULTS: Of the 9522 patients with stroke, 307 (27%) with hyperhomocysteinemia (hHcy) had recurrent stroke. Univariate Cox regression model showed that hHcy group was associated with recurrent stroke (crude hazard ratio [HR] 1.16; 95% CI 1.02-1.30). But there was no such association in multivariate regression models (adjusted HR 1.11; 95% CI .97-1.26). hHcy was not associated with any ischemic stroke subtypes at 5 years. Univariate Cox regression model showed that hHcy group was associated with overall cardiovascular events (crude HR 1.44; 95% CI 1.32-1.57). However, this association no longer existed in multivariate regression models (adjusted HR 1.01; 95% CI .93-1.12). Higher plasma Hcy group was significantly associated with higher mortality compared with normal plasma Hcy group (OR 1.83; 95% CI .45-2.32). CONCLUSIONS: Our results showed that elevated Hcy is not associated independently with stroke recurrence and overall cardiovascular events in patients with ischemic stroke. There was no association between the hHcy and stroke recurrence in the stroke subtypes within 5 years.

Impacts of global transcriptional regulators on persister metabolism.

Bacterial persisters are phenotypic variants with an extraordinary capacity to tolerate antibiotics, and they are hypothesized to be a main cause of chronic and relapsing infections. Recent evidence has suggested that the metabolism of persisters can be targeted to develop therapeutic countermeasures; however, knowledge of persister metabolism remains limited due to difficulties associated with isolating these rare and transient phenotypic variants. By using a technique to measure persister catabolic activity, which is based on the ability of metabolites to enable aminoglycoside (AG) killing of persisters, we investigated the role of seven global transcriptional regulators (ArcA, Cra, cyclic AMP [cAMP] receptor protein [CRP], DksA, FNR, Lrp, and RpoS) on persister metabolism. We found that removal of CRP resulted in a loss of AG potentiation in persisters for all metabolites tested. These results highlight a central role for cAMP/CRP in persister metabolism, as its perturbation can significantly diminish the metabolic capabilities of persisters and effectively eliminate the ability of AGs to eradicate these troublesome bacteria.

Cognitive Decline in Patients with Leukoaraiosis Within 5 Years after Initial Stroke.

BACKGROUND: Leukoaraiosis (LA) is closely associated with cognitive deficits. The association between LA and cognitive disorders, such as mild cognitive impairment (MCI) and dementia, after initial stroke has not been systematically studied. In this study, we sought to identify whether LA contributes to the occurrence of certain type of cognitive disorders after initial stroke. METHODS: Data from our Stroke Registry were examined, and 5-year follow-up data for LA and cognitive disorders were analyzed. We performed Kaplan-Meier analysis and log-rank test to assess the predictive value of LA for risk of cognitive decline and the Cox proportional hazards model to test the risk factors studied as independent determinants of cognitive impairment. RESULTS: The frequency of patients with normal cognitive function decreased significantly at 5 years compared with initial stroke (78% vs 70%; odds ratio, 1.51; 95% confidence interval, 1.41-1.62). Of 8784 patients, 1659 (19%) had dementia and 964 (11%) had MCI at the final analysis. After 5 years of follow-up, survival analysis showed that all patients with LA had an increased probability of MCI compared with those without LA (P < .0001). Patients with LA had an increased chance of dementia compared with those without LA (P < .0001) at the end of follow-up. Cognitive decline probability was significantly higher in patients with severe LA compared with those with mild/moderate LA (P < .0001). Cox regression analyses showed that recurrence of stroke (hazard ratio [HR], 3.92 [95% CI, 3.26-4.72]), hypertension (HR, 1.11 [95% CI, 1.0-1.22]), LA (HR, 1.15 [95% CI, 1.05-1.25]), age (HR, 1.05 [95% CI, 1.04-1.06]), hypercholesterolemia (HR, .86 [95% CI, .77-.95]), higher LDL cholesterol (HR, 1.21 [95% CI, 1.11-1.32]), lower HDL cholesterol (HR, .90 [95% CI, .83-.98]), coronary heart disease (HR, .85 [95% CI, .77-.94]), and National Institutes of Health Stroke Scale score at admission (HR, .77 [95% CI, .72-.82]) were also significantly associated with cognitive impairments. CONCLUSIONS: Our findings suggest that patients with LA may be at risk of developing new cognitive impairments at long-term period after initial stroke. The evaluation of the concomitant risk factors, besides providing insights about the possible mechanisms behind the cognitive dysfunction present in LA, may be of help for the prevention of cognitive impairments.