Inducible nitric oxide synthase links NF-κB to PGE(2 )in polyunsaturated fatty acid altered fibroblast in-vitro wound healing

BACKGROUND: This study investigated mechanisms of altered fibroblast collagen production induced by polyunsaturated fatty acids. 3T3-Swiss fibroblasts were grown in medium containing either eicosapentaenoic or arachidonic acid. The effects of nuclear factor-kappaB activation by lipopolysaccharide on inducible nitric oxide synthase, nitric oxide, prostaglandin E(2), collagen production, and in-vitro wound healing were studied. RESULTS: Eicosapentaenoic acid treated cells produced less prostaglandin E(2 )but had increased inducible nitric oxide synthase expression, nitric oxide production, collagen formation, and recoverage area during in-vitro wound healing than cells treated with arachidonic acid. Activation of nuclear factor-kappaB with lipopolysaccharide increased inducible nitric oxide synthase expression, the production of nitric oxide, prostaglandin E(2), collagen, and the in-vitro wound recoverage area. The nitric oxide synthase inhibitor, N(G)-nitro-L-arginine methyl ester, decreased lipopolysaccharide-induced nitric oxide, but the amount of nitric oxide was greater in eicosapentaenoic acid treated cells. N(G)-nitro-L-arginine methyl ester plus lipopolysaccharide treatment increased collagen production and cellular recoverage area while treatment with N(G)-nitro-L-arginine methyl ester alone decreased it in wounded fibroblasts. CONCLUSION: The activation of the NF-κB pathway and PGE(2 )can be linked by the cross-talk of iNOS and NO in the PUFA altered fibroblast collagen production and wound healing. Additional studies are needed to determine how polyunsaturated fatty acids can be used as adjuvants in combination with other treatments (i.e, drugs) to design therapies to either enhance healthy collagen production or inhibit production and reduce fibrosis

Evidence That Free Fatty Acid-Iron Complexes Directly Initiate Lipid Peroxidation in Vitro and in Vivo: A New Mechanism of Oxidative Stress

Through a series of biochemical and histochemical experiments we explored the novel hypothesis that iron and free fatty acids, liberated after tissue injury, combine to form liposoluble complexes that directly initiate lipid peroxidation. The addition of 100 M ferric iron to 30 mM linoleate suspensions at pH 7.4 produced time dependent lipid peroxidation, measured as conjugated diene formation. Complexes of 100 M ferric iron and 600 M pentanoate also initiated formation of conjugated dienes in linoleate suspensions and formation of malondialdehyde-like materials in rat liver slices. A histochemical stain for free fatty acids revealed positive reactions within cell membranes in traumatized regions of rat liver tissue that underwent compression injury followed by thirty minutes of blood perfusion, but not in nontraumatized control regions. The diaminobenzidine-H2O2 histochemical reaction for iron, revealed increased levels of redox cyclable iron in the membranes and the cytoplasm of traumatized hepatocytes. We propose that traumatic injury initiates cascades leading to liberation of iron from storage proteins and free fatty acids from membranes, which combine, distribute to the lipid domains of cell membranes, and directly initiate lipid peroxidation

Cervical keratinocytes containing stably replicating extrachromosomal HPV-16 are refractory to transformation by oncogenic H-Ras

AbstractRas expression in human epithelial cells with integrated HPV genomes has been shown to cause tumorigenic transformation. The effects of Ras in cells representing early stage HPV-associated disease (i.e., when HPV is extrachromosomal and the oncogenes are under control of native promoters) have not been examined. Here, we used human cervical keratinocyte cell lines containing stably replicating extrachromosomal HPV-16 and present the novel finding that these cells resist transformation by oncogenic H-Ras. Ras expression consistently diminished anchorage-independent growth (AI), reduced E6 and E7 expression, and caused p53 induction in these cells. Conversely, AI was enhanced or maintained in Ras-transduced cervical cells that were immortalized with a 16E6/E7 retrovirus, and minimal effects on E6 and E7 expression were observed. Ras expression with either episomal HPV-16 or LXSN-E6/E7 was insufficient for tumorigenic growth suggesting that other events are needed for tumorigenic transformation. In conclusion, our results indicate that Ras-mediated transformation depends on the context of HPV oncogene expression and that this is an important point to address when developing HPV tumor models

A randomized trial of aspirin on the risk of embolic events in patients with infective endocarditis

AbstractObjectivesThis study examined the effect of aspirin on the risk of embolic events in infective endocarditis (IE).BackgroundEmbolism is a major complication of IE, and studies in animal models have shown that platelet inhibition with aspirin can lead to more rapid vegetation resolution and a lower rate of embolic events.MethodsWe conducted a randomized, double-blinded, placebo-controlled trial of aspirin treatment (325 mg/day) for four weeks in patients with IE to test the hypothesis that the addition of aspirin would reduce the incidence of clinical systemic embolic events. Patients with perivalvular abscess were excluded. Serial cerebral computed tomograms and transesophageal echocardiograms were obtained in a subset of patients.ResultsDuring the four-year study period, 115 patients were enrolled: 60 assigned to aspirin and 55 assigned to placebo. Embolic events occurred in 17 patients (28.3%) on aspirin and 11 patients (20.0%) on placebo, with an odds ratio (OR) of 1.62 (95% confidence interval [CI] 0.68 to 3.86, p = 0.29). There was a trend toward a higher incidence of bleeding in the patients taking aspirin versus placebo (OR 1.92, 95% CI 0.76 to 4.86, p = 0.075). Development of new intracranial lesions was similar in both groups. Aspirin had no effect on vegetation resolution and valvular dysfunction.ConclusionsIn endocarditis patients already receiving antibiotic treatment, the addition of aspirin does not appear to reduce the risk of embolic events and is likely associated with an increased risk of bleeding. Aspirin is not indicated in the early management of patients with IE

Novel missense mutations of the Deleted-in-AZoospermia-Like (DAZL) gene in infertile women and men

BACKGROUND: The Deleted-in-AZoospermia-Like (DAZL) gene has homologs required for germ cell development in many organisms. Recently, we showed that there are several common polymorphisms within the DAZL gene that are associated with age at ovarian failure/menopause and sperm count. METHODS: Here we sought to identify rare mutations in DAZL and examine their phenotypes in men and women. We sequenced the DAZL gene in 519 individuals; sequences spanned the entire coding region of the gene. RESULTS: We report the identification of four putative missense mutations in DAZL. Three individuals that were heterozygous for a DAZL mutation reported having children, while two individuals that were homozygous reported no children. These mutations were found only in infertile men and women. CONCLUSION: Given the strong data associating DAZL polymorphisms and deletions with fertility in humans and model organisms, we suggest that these mutations may be associated with age at menopause and/or sperm count and warrant further biochemical and genetic investigation

Comparison of the talk test and percent heart rate reserve for exercise prescription

Exercise intensity is traditionally prescribed using %HRmax, %HRR, %VO2max, or %VO2R. Recently, the Talk Test (TT) has been proposed as an alternative method to guide exercise intensity. However, it is unknown if prescribing exercise intensity solely using the TT can provoke training responses that are comparable to traditional guidelines. This study compared the responses to training using either the TT or %HRR. Forty-four subjects (17 males and 27 females: age=20.4±3.02 years; body height=170.5±9.79 cm; body weight=71.9±13.63 kg) completed an incremental maximal cycle ergometer test, were stratified by VO2max and gender, and randomly assigned to training groups guided by either %HRR (n=20) or the TT (n=24). Both groups completed 40-minute training sessions three days per week for 10 weeks. In the HRR group, exercise intensity was targeted (per ACSM guidelines) at 40-59% HRR for weeks 1-4, 50-59% HRR for weeks 5-8, and 60-79% HRR for weeks 9-10. In the TT group, exercise intensity was targeted at the highest power output (PO) that still allowed for comfortable speech. Changes in VO2max, peak power output (PPO), VO2 at ventilatory threshold (VT), and PO at VT were compared between the groups using two-way ANOVA with repeated measures. There were significant (p0.05) interaction effect. Guiding exercise prescription using the TT is a simple and effective method for prescribing exercise intensity and elicits improvements in exercise performance that are comparable to the traditional %HRR guidelines

Refined saddle-point preconditioners for discretized Stokes problems

This paper is concerned with the implementation of efficient solution algorithms for elliptic problems with constraints. We establish theory which shows that including a simple scaling within well-established block diagonal preconditioners for Stokes problems can result in significantly faster convergence when applying the preconditioned MINRES method. The codes used in the numerical studies are available online

Circadian control of mouse heart rate and blood pressure by the suprachiasmatic nuclei:behavioral effects are more significant than direct outputs

Diurnal variations in the incidence of events such as heart attack and stroke suggest a role for circadian rhythms in the etiology of cardiovascular disease. The aim of this study was to assess the influence of the suprachiasmatic nucleus (SCN) circadian clock on cardiovascular function. mice and WT. However, there was also a modest circadian rhythm of resting HR and BP that was independent of LA.If appropriate methods of analysis are used that take into account sleep and locomotor activity level, mice are a good model for understanding the contribution of circadian timing to cardiovascular function. Future studies of the influence of sleep and wakefulness on cardiovascular physiology may help to explain accumulating evidence linking disrupted sleep with cardiovascular disease in man

Uncovering the Genetic Landscape for Multiple Sleep-Wake Traits

Despite decades of research in defining sleep-wake properties in mammals, little is known about the nature or identity of genes that regulate sleep, a fundamental behaviour that in humans occupies about one-third of the entire lifespan. While genome-wide association studies in humans and quantitative trait loci (QTL) analyses in mice have identified candidate genes for an increasing number of complex traits and genetic diseases, the resources and time-consuming process necessary for obtaining detailed quantitative data have made sleep seemingly intractable to similar large-scale genomic approaches. Here we describe analysis of 20 sleep-wake traits from 269 mice from a genetically segregating population that reveals 52 significant QTL representing a minimum of 20 genomic loci. While many (28) QTL affected a particular sleep-wake trait (e.g., amount of wake) across the full 24-hr day, other loci only affected a trait in the light or dark period while some loci had opposite effects on the trait during the light vs. dark. Analysis of a dataset for multiple sleep-wake traits led to previously undetected interactions (including the differential genetic control of number and duration of REM bouts), as well as possible shared genetic regulatory mechanisms for seemingly different unrelated sleep-wake traits (e.g., number of arousals and REM latency). Construction of a Bayesian network for sleep-wake traits and loci led to the identification of sub-networks of linkage not detectable in smaller data sets or limited single-trait analyses. For example, the network analyses revealed a novel chain of causal relationships between the chromosome 17@29cM QTL, total amount of wake, and duration of wake bouts in both light and dark periods that implies a mechanism whereby overall sleep need, mediated by this locus, in turn determines the length of each wake bout. Taken together, the present results reveal a complex genetic landscape underlying multiple sleep-wake traits and emphasize the need for a systems biology approach for elucidating the full extent of the genetic regulatory mechanisms of this complex and universal behavior