Application of step-wise discriminant analysis and Bayesian classification procedure in determining prognosis of acute myocardial infarction.

A retrospective study was carried out to assess the feasibility of computer-assisted prognostication by discriminant analysis and the Bayesian classification procedure based on clinical information collected on patients with acute myocardial infarction. The overall accuracy was 94.2% in predicting hospital death but the prediction of late death after discharge was less accurate. It was found that not all of the 44 variables used for analysis were necessary to reach the same level of predictive accuracy--16 to 20 variables would result in almost the identical prediction. The Bayesian classification procedure was applied to estimate probabilities of individual patients belonging to the different prognostic categories.     

A Possible Role of Repetitious DNA in Recombinatory Joining during Chromosome Rearrangement in DROSOPHILA MELANOGASTER

It is postulated that certain repetitious DNA components play a role in the recombination processes during chromosome rearrangements. When the distribution of silver grain densities after the in situ hybridization of repetitious DNA (Rudkin and Tartof 1973) and the distribution of chromosome breaks due to X-irradiation (Kaufmann 1946) are compared, a strong correlation is found for the euchromatic portion of the D. melanogaster salivary X chromosome. These observations justify the postulate above that certain repetitious DNA provides homologous regions in the DNA of broken chromosome ends necessary for proper recombinatory joining.     

Release of Endocannabinoids into the Cerebrospinal Fluid during the Induction of the Trigemino-Hypoglossal Reflex in Rats

The endocannabinoid system (ECS) plays an important role in pain processing and modulation. Since the specific effects of endocannabinoids within the orofacial area are largely unknown, we aimed to determine whether an increase in the endocannabinoid concentration in the cerebrospinal fluid (CSF) caused by the peripheral administration of the FAAH inhibitor URB597 and tooth pulp stimulation would affect the transmission of impulses between the sensory and motor centers localized in the vicinity of the third and fourth cerebral ventricles. The study objectives were evaluated on rats using a method that allowed the recording of the amplitude of evoked tongue jerks (ETJ) in response to noxious tooth pulp stimulation and URB597 treatment. The amplitude of ETJ was a measure of the effect of endocannabinoids on the neural structures. The concentrations of the endocannabinoids tested (AEA and 2-AG) were determined in the CSF, along with the expression of the cannabinoid receptors (CB1 and CB2) in the tissues of the mesencephalon, thalamus, and hypothalamus. We demonstrated that anandamide (AEA), but not 2-arachidonoylglycerol (2-AG), was significantly increased in the CSF after treatment with a FAAH inhibitor, while tooth pulp stimulation had no effect on the AEA and 2-AG concentrations in the CSF. We also found positive correlations between the CSF AEA concentration and cannabinoid receptor type 1 (CB1R) expression in the brain, and between 2-AG and cannabinoid receptor type 2 (CB2R), and negative correlations between the CSF concentration of AEA and brain CB2R expression, and between 2-AG and CB1R. Our study shows that endogenous AEA, which diffuses through the cerebroventricular ependyma into CSF and exerts a modulatory effect mediated by CB1Rs, alters the properties of neurons in the trigeminal sensory nuclei, interneurons, and motoneurons of the hypoglossal nerve. In addition, our findings may be consistent with the emerging concept that AEA and 2-AG have different regulatory mechanisms because they are involved differently in orofacial pain. We also suggest that FAAH inhibition may offer a therapeutic approach to the treatment of orofacial pain.     

AvrRps4 effector family processing and recognition in lettuce

During pathogenesis, effector proteins are secreted from the pathogen to the host plant to provide virulence activity for invasion of the host. However, once the host plant recognizes one of the delivered effectors, effector‐triggered immunity activates a robust immune and hypersensitive response (HR). In planta, the effector AvrRps4 is processed into the N‐terminus (AvrRps4^N) and the C‐terminus (AvrRps4^C). AvrRps4^C is sufficient to trigger HR in turnip and activate AtRRS1/AtRPS4‐mediated immunity in Arabidopsis; on the other hand, AvrRps4^N induces HR in lettuce. Furthermore, AvrRps4^N‐mediated HR requires a conserved arginine at position 112 (R112), which is also important for full‐length AvrRps4 (AvrRps4^F) processing. Here, we show that effector processing and effector recognition in lettuce are uncoupled for the AvrRps4 family. In addition, we compared effector recognition by lettuce of AvrRps4 and its homologues, HopK1 and XopO. Interestingly, unlike for AvrRps4 and HopK1, mutation of the conserved R111 in XopO by itself was insufficient to abolish recognition. The combination of amino acid substitutions arginine 111 to leucine with glutamate 114 to lysine abolished the XopO‐mediated HR, suggesting that AvrRps4 family members have distinct structural requirements for perception by lettuce. Together, our results provide an insight into the processing and recognition of AvrRps4 and its homologues.     

Participation of lipopolysaccharide in hyperplasic adipose expansion: Involvement of NADPH oxidase/ROS/p42/p44 MAPK‐dependent Cyclooxygenase‐2

Obesity is a world‐wide problem, especially the child obesity, with the complication of various metabolic diseases. Child obesity can be developed as early as the age between 2 and 6. The expansion of fat mass in child age includes both hyperplasia and hypertrophy of adipose tissue, suggesting the importance of proliferation and adipogenesis of preadipocytes. The changed composition of gut microbiota is associated with obesity, revealing the roles of lipopolysaccharide (LPS) on manipulating adipose tissue development. Studies suggest that LPS enters the circulation and acts as a pro‐inflammatory regulator to facilitate pathologies. Nevertheless, the underlying mechanisms behind LPS‐modulated obesity are yet clearly elucidated. This study showed that LPS enhanced the expression of cyclooxygenase‐2 (COX‐2), an inflammatory regulator of obesity, in preadipocytes. Pretreating preadipocytes with the scavenger of reactive oxygen species (ROS) or the inhibitors of NADPH oxidase or p42/p44 MAPK markedly decreased LPS‐stimulated gene expression of COX‐2 together with the phosphorylation of p47^phox and p42/p44 MAPK, separately. LPS activated p42/p44 MAPK via NADPH oxidase‐dependent ROS accumulation in preadipocytes. Reduction of intracellular ROS or attenuation of p42/p44 MAPK activation both reduced LPS‐mediated COX‐2 expression and preadipocyte proliferation. Moreover, LPS‐induced preadipocyte proliferation and adipogenesis were abolished by the inhibition of COX‐2 or PEG₂ receptors. Taken together, our results suggested that LPS enhanced the proliferation and adipogenesis of preadipocytes via NADPH oxidase/ROS/p42/p44 MAPK‐dependent COX‐2 expression.     

IL‐23 plays a significant role in the augmentation of particulate matter‐mediated allergic airway inflammation

It has been recently that particulate matter (PM) exposure increases the risk and exacerbation of allergic asthma. However, the underlying mechanisms and factors associated with increased allergic responses remain elusive. We evaluated IL‐23 and IL‐23R (receptor) expression, as well as changes in the asthmatic phenotype in mice administered PM and a low dose of house dust mite (HDM). Next, changes in the phenotype and immune responses were evaluated after intranasal administration of anti‐IL‐23 antibody during co‐exposure to PM and low‐dose HDM. We also performed in vitro experiments to investigate the effect of IL‐23. IL‐23 expression was significantly increased in Epcam+CD45− and CD11c+ cells, while that of IL‐23R was increased in Epcam+CD45− cells only in mice administered PM and low‐dose HDM. Administration of anti‐IL‐23 antibody led to decreased airway hyperresponsiveness, eosinophils, and activation of dendritic cells, reduced populations of Th2 Th17, ILC2, the level of IL‐33 and granulocyte‐macrophage colony‐stimulating factor (GM‐CSF). Inhibition of IL‐23 in PM and low‐dose HDM stimulated airway epithelial cell line resulted in decreased IL‐33, GM‐CSF and affected ILC2 and the activation of BMDCs. PM augmented the phenotypes and immunologic responses of asthma even at low doses of HDM. Interestingly, IL‐23 affected immunological changes in airway epithelial cells.     

Genome-scale patterns in the loss of heterozygosity incidence in Saccharomyces cerevisiae

Former studies have established that loss of heterozygosity can be a key driver of sequence evolution in unicellular eukaryotes and tissues of metazoans. However, little is known about whether the distribution of loss of heterozygosity events is largely random or forms discernible patterns across genomes. To initiate our experiments, we introduced selectable markers to both arms of all chromosomes of the budding yeast. Subsequent extensive assays, repeated over several genetic backgrounds and environments, provided a wealth of information on the genetic and environmental determinants of loss of heterozygosity. Three findings stand out. First, the number of loss of heterozygosity events per unit time was more than 25 times higher for growing than starving cells. Second, loss of heterozygosity was most frequent when regions of homology around a recombination site were identical, about a half-% sequence divergence was sufficient to reduce its incidence. Finally, the density of loss of heterozygosity events was highly dependent on the genome’s physical architecture. It was several-fold higher on short chromosomal arms than on long ones. Comparably large differences were seen within a single arm where regions close to a centromere were visibly less affected than regions close, though usually not strictly adjacent, to a telomere. We suggest that the observed uneven distribution of loss of heterozygosity events could have been caused not only by an uneven density of initial DNA damages. Location-depended differences in the mode of DNA repair, or its effect on fitness, were likely to operate as well.     

17β‐Oestradiol facilitates M2 macrophage skewing and ameliorates arrhythmias in ovariectomized female infarcted rats

Epidemiological studies have suggested a lower incidence of arrhythmia‐induced sudden cardiac death in women than in men. 17β‐oestradiol (E2) has been reported to have a post‐myocardial infarction antiarrhythmic effect, although the mechanisms have yet to be elucidated. We investigated whether E2‐mediated antioxidation regulates macrophage polarization and affects cardiac sympathetic reinnervation in rats after MI. Ovariectomized Wistar rats were randomly assigned to placebo pellets, E2 treatment, or E2 treatment +3‐morpholinosydnonimine (a peroxynitrite generator) and followed for 4 weeks. The infarct sizes were similar among the infarcted groups. At Day 3 after infarction, post‐infarction was associated with increased superoxide levels, which were inhibited by administering E2. E2 significantly increased myocardial IL‐10 levels and the percentage of regulatory M2 macrophages compared with the ovariectomized infarcted alone group as assessed by immunohistochemical staining, Western blot and RT‐PCR. Nerve growth factor colocalized with both M1 and M2 macrophages at the magnitude significantly higher in M1 compared with M2. At Day 28 after infarction, E2 was associated with attenuated myocardial norepinephrine levels and sympathetic hyperinnervation. These effects of E2 were functionally translated in inhibiting fatal arrhythmias. The beneficial effect of E2 on macrophage polarization and sympathetic hyperinnervation was abolished by 3‐morpholinosydnonimine. Our results indicated that E2 polarized macrophages into the M2 phenotype by inhibiting the superoxide pathway, leading to attenuated nerve growth factor‐induced sympathetic hyperinnervation after myocardial infarction.