Pseudomonas aeruginosa elastase induces IL-8 production in the lung cells via the epidermal growth factor/extracellular signal-regulated proteins/NFκB pathway

Background: The induction of chemokine secretion by fibroblasts is crucial for the migration of leukocytes into the parenchyma of the injured lung. Several bacterial products activate the lung’s structural as well as immune cells to produce pro inflammatory cytokines and chemokines. We report that elastase from Pseudomonas aeruginosa (PE) evokes IL-8 mRNA expression and protein secretion in nonmalignant culture of human lung fibroblasts by activating the receptor for epidermal growth factor (EGFR) and downstream mitogen-activated protein kinases (MAPK) pathway. Methods: We utilized western blot analysis to detect phosphorylation of EGFR and signal transduction intermediates. Northern blot and ELISA analyses were used to determine IL-8 RNA expression and cytokine secretion. Results: We found that the enzymatically active PE enhances IL-8mRNA and protein secretion but does not increase IL-10 or TNF expression. PE induces phosphorylation of the EGFR and the extracellular signal-regulated proteins (ERK1/2) of the MAPK pathway. Pretreatment of the cells with neutralizing antibody to EGFR or the EGFR-specific tyrphostin AG1478 markedly attenuated the PE-induced ERK1/2 activation. PE-induced IL-8 expression is also abolished in the presence of the MEK inhibitor U0126,indicating the involvement of ERK1/2 in this process. Conclusion: Taken together, the results show PE could modulate lung inflammation by exploiting the EGFR/ERK/NFκB pathway and enhancing IL-8 production by lung fibroblasts

Nonlinear dynamics analysis of the human balance control subjected to physical and sensory perturbations

Postural control after applying perturbation involves neural and muscular efforts to limit the center of mass (CoM) motion. Linear dynamical approaches may not unveil all complexities of body efforts. This study was aimed at determining two nonlinear dynamics parameters (fractal dimension (FD) and largest Lyapunov exponent (LLE)) in addition to the linear standing metrics of balance in perturbed stance. Sixteen healthy young males were subjected to sudden rotations of the standing platform. The vision and cognition during the standing were also interfered. Motion capturing was used to measure the lower limb joints and the CoM displacements. The CoM path length as a linear parameter was increased by elimination of vision (p<0.01) and adding a cognitive load (p<0.01). The CoM nonlinear metric FD was decreased due to the cognitive loads (p<0.001). The visual interference increased the FD of all joints when the task included the cognitive loads (p<0.01). The slightly positive LLE values showed weakly-chaotic behavior of the whole body. The local joint rotations indicated higher LLEs. Results indicated weakly chaotic response of the whole body. Increase in the task difficulty by adding sensory interference had difference effects on parameters. Linear and nonlinear metrics of the perturbed stance showed that a combination of them may properly represent the body behavior

Abdominal hollowing and lateral abdominal wall muscles' activity in both healthy men & women: An ultrasonic assessment in supine and standing positions

The objective of this study was to investigate the effects of Abdominal Hollowing (AH) maneuver on External Oblique (EO), Internal Oblique (IO) and Transversus Abdominis (TrA) muscles in both healthy men and women during the two postures of supine and upright standing. The study was conducted on 43 asymptomatic volunteers (22 males and 21 females) aged 19-44 (27.8 ± 6.4) years. Rehabilitative Ultrasonic Imaging (RUSI) was simultaneously performed to measure muscle thickness in both rest and during AH maneuvers while activation of the TrA during AH was controlled by Pressure Biofeedback (PBF) device. Mixed-model ANOVA with repeated measures design, and Pearson correlation tests were used to analyze the data. Muscle thickness of all muscles was significantly higher for male subjects (F> 6.2, p< 0.017). The interaction effect of gender and muscle status was significant only for IO (F= 7.458, p= 0.009) indicating that AH maneuver increased the thickness of IO in men. Interaction effect of posture and muscle status on muscular thickness indicated that changing position only affects the resting thickness of TrA (F= 5.617, p= 0.023). Standing posture significantly affected the TrA contraction ratio (t= 3.122, p= 0.003) and TrA preferential activation ratio (t= 2.76, p= 0.008). There was no relationship between age and muscle thickness (r= 0.262, p= 0.09). The PBF has been introduced as a clinical and available device for monitoring TrA activity, while RUSI showed that both TrA and IO muscles had activated after AH maneuver. We recommend performing further investigations using electromyography and RUSI simultaneously at more functional postures such as upright standing. © 2009

Comparison of Static and Dynamic Alignment of the Head and Cervical Vertebrae ‎Between Male and Female Students of Isfahan University of Medical Sciences

Purpose:Assessing the alignment or posture of the spine is one of the important stages of the examination in patients with musculoskeletal disorders, such as head and cervical spine pain. The aim of this study was to determine the difference in the alignment or posture of the head and cervical vertebrae in male and female students.Methods:The research was a cross-sectional study in which 175 male and female students studying at Isfahan University of Medical Sciences were investigated using a convenience sampling method. Analysis of the alignment of the head and cervical vertebrae was performed in static and dynamic positions in the sagittal plane, in a sitting position. The photographic method was used to evaluate the alignment. An independent sample t-test was applied to statistical analysis.Results:In this study, 100 female and 75 male students were examined. The age range of the participants was 18 to 27 years. In the static sitting position, the difference in the lower cervical angle and cervical deviation in the neutral position of the head and neck between the male and females was significant (p<0.05). During movement, significant changes were observed in some angles (p<0.05).Conclusion:Based on the results of this study, the static and dynamic alignment of the head and cervical vertebrae in male and female students were different in the sagittal plane. It is recommended to carry out more kinesiology studies to quantitatively analyze the movements of different parts of the spine in both sexes

Long-Distance Delivery of Bacterial Virulence Factors by Pseudomonas aeruginosa Outer Membrane Vesicles

Bacteria use a variety of secreted virulence factors to manipulate host cells, thereby causing significant morbidity and mortality. We report a mechanism for the long-distance delivery of multiple bacterial virulence factors, simultaneously and directly into the host cell cytoplasm, thus obviating the need for direct interaction of the pathogen with the host cell to cause cytotoxicity. We show that outer membrane–derived vesicles (OMV) secreted by the opportunistic human pathogen Pseudomonas aeruginosa deliver multiple virulence factors, including β-lactamase, alkaline phosphatase, hemolytic phospholipase C, and Cif, directly into the host cytoplasm via fusion of OMV with lipid rafts in the host plasma membrane. These virulence factors enter the cytoplasm of the host cell via N-WASP–mediated actin trafficking, where they rapidly distribute to specific subcellular locations to affect host cell biology. We propose that secreted virulence factors are not released individually as naked proteins into the surrounding milieu where they may randomly contact the surface of the host cell, but instead bacterial derived OMV deliver multiple virulence factors simultaneously and directly into the host cell cytoplasm in a coordinated manner

Serological Evaluation and Molecular Genotyping of Toxoplasma gondii in Pregnant Women in Meshkin-Shahr District, Northwestern Iran

Background: We aimed to investigate the serological and molecular characteristics of Toxoplasma gondii infection among pregnant women and their aborted placentas in Meshkin-Shahr City during 2019-2020. Methods: Blood samples of 210 pregnant women were evaluated for anti-T. gondii antibodies and related risk factors were determined. Also, the sera of aborted women and their buffy coats and aborted placenta tissues were used to detect anti-Toxoplasma antibodies and the parasite’s DNA, respectively. The parasite genotypes were determined by the PCR-RFLP using the SAG3 gene.  Results: The overall prevalence of anti-Toxoplasma IgG was 24.3% and only 1% of participants were seropositive for the IgM antibody. There was a significant relationship between raw or unwashed vegetable consumption, contact with soil, vegetable/fruit washing type, and seropositivity (P<0.05). During pregnancy, 4.7% of women encountered an abortion and 30% and 50% of cases were positive for IgG antibodies before and after abortion, respectively. Only two cases were IgM seropositive after abortion. In the avidity IgG test, 20% of cases showed low avidity. BLAST and phylogenetic analysis exhibited that all isolates belonged to the type III T. gondii genotype. Although two women with spontaneous abortions showed seropositivity for IgM T. gondii antibody, parasite DNA was detected in three cases. Conclusion: The seroprevalence of Toxoplasma infection is not high in pregnant women. Seropositive women are not safe from congenital transmission. T. gondii type III is the etiology of fetus infection in mothers with spontaneous abortion. It seems that screening and essential care are still necessary during pregnancy