Resistance exercising on unstable surface leads to Pupil Dilation.

BACKGROUND: Chronic resistance training and acute resistance exercises improve physical performance and can enhance cognitive performance. However, there is still uncertainty about the mechanism(s) responsible for cognitive improvement following resistance training and exercise. Recent findings suggest that resistance exercise has metabolic as well as cognitive demands, which potentially activate similar neural circuitry associated with higher-order cognitive function tasks. Exercising on unstable devices increases the coordinative and metabolic demands and thus may further increase cognitive activation during resistance exercise. The measurement of pupil diameter could provide indications of cognitive activation and arousal during resistance exercise. Pupil dilation is linked to the activity in multiple neuromodulatory systems (e.g., activation of the locus coeruleus and the release of the neurotransmitter norepinephrine (LC-NE system)), which are involved in supporting processes for executive control. Therefore, the purpose of this study was to compare the cognitive activation measured by pupil diameter during an acute bout of resistance exercise on stable and unstable surfaces. METHODS: 18 participants (23.5 ± 1.5 years; 10 females) performed ten kettlebell squats in a preferred repetition velocity in stable and unstable (BOSU® Balance Trainer) ground conditions. Pupil diameter was recorded with eye tracking glasses (SMI ETG) during standing (baseline) and during squatting. Raw pupil data were cleaned of artifacts (missing values were linearly interpolated) and subjected to a subtractive baseline correction. A student t-test was used to compare mean pupil diameter between ground conditions. RESULTS: The mean pupil diameter was significantly greater during squats in the unstable condition than in the stable condition, t (17) = -2.63, p =.018, Cohen's dZ = -0.62; stable: 0.49 ± 0.32 mm; unstable: 0.61 ± 0.25 mm). CONCLUSION: As indicated by pupil dilation, the use of unstable devices can increase the cognitive activation and effort during acute bouts of resistance exercise. Since pupil dilation is only an indirect method, further investigations are necessary to describe causes and effects of neuromodulatory system activity during resistance exercise. Resistance training with and without surface instability can be recommended to people of all ages as a physically and cognitively challenging training program contributing to the preservation of both physical and cognitive functioning.

Screening for Resistant Bacteria, Antimicrobial Resistance Genes, Sexually Transmitted Infections and Schistosoma spp. in Tissue Samples from Predominantly Vaginally Delivered Placentae in Ivory Coast and Ghana.

Medical complications during pregnancy have been frequently reported from Western Africa with a particular importance of infectious complications. Placental tissue can either become the target of infectious agents itself, such as, e.g., in the case of urogenital schistosomiasis, or be subjected to contamination with colonizing or infection-associated microorganisms of the cervix or the vagina during vaginal delivery. In the retrospective cross-sectional assessment presented here, the quantitative dimension of infection or colonization with selected resistant or pathogenic bacteria and parasites was regionally assessed. To do so, 274 collected placental tissues from Ivory Coastal and Ghanaian women were subjected to selective growth of resistant bacteria, as well as to molecular screening for beta-lactamase genes, Schistosoma spp. and selected bacterial causative agents of sexually transmitted infections (STI). Panton-Valentine-negative methicillin-resistant Staphylococcus aureus (MRSA) was grown from 1.8% of the tissue samples, comprising the spa types t008 and t688, as well as the newly detected ones, t12101 (n = 2) and t12102. While the culture-based recovery of resistant Enterobacterales and nonfermentative rod-shaped Gram-negative bacteria failed, molecular assessments confirmed beta-lactamase genes in 31.0% of the samples with multiple detections of up to four resistance genes per sample and blaCTX-M, blaIMP, blaGES, blaVIM, blaOXA-58-like, blaNDM, blaOXA-23-like, blaOXA-48-like and blaKPC occurring in descending order of frequency. The beta-lactamase genes blaOXA-40/24-like, blaNMC_A/IMI, blaBIC, blaSME, blaGIM and blaDIM were not detected. DNA of the urogenital schistosomiasis-associated Schistosoma haematobium complex was recorded in 18.6% of the samples, but only a single positive signal for S. mansoni with a high cycle-threshold value in real-time PCR was found. Of note, higher rates of schistosomiasis were observed in Ghana (54.9% vs. 10.3% in Ivory Coast) and Cesarean section was much more frequent in schistosomiasis patients (61.9% vs. 14.8% in women without Schistosoma spp. DNA in the placenta). Nucleic acid sequences of nonlymphogranuloma-venereum-associated Chlamydia trachomatis and of Neisseria gonorrhoeae were recorded in 1.1% and 1.9% of the samples, respectively, while molecular attempts to diagnose Treponema pallidum and Mycoplasma genitalium did not lead to positive results. Molecular detection of Schistosoma spp. or STI-associated pathogens was only exceptionally associated with multiple resistance gene detections in the same sample, suggesting epidemiological distinctness. In conclusion, the assessment confirmed considerable prevalence of urogenital schistosomiasis and resistant bacterial colonization, as well as a regionally expected abundance of STI-associated pathogens. Continuous screening offers seem advisable to minimize the risks for the pregnant women and their newborns.

Gait on slopes: Differences in temporo-spatial, kinematic and kinetic gait parameters between walking on a ramp and on a treadmill.

BACKGROUND: Inclined treadmills or static ramp constructions can be used to investigate downhill gait in a standardised laboratory condition. There is a lack of information how the gait patterns are affected when walking on a ramp or an inclined treadmill during uphill and downhill walking. RESEARCH QUESTION: Is there a difference in temporo-spatial parameters, sagittal ankle, knee and hip joint angle as well as ground reaction force when walking uphill and downhill on a ramp and a treadmill. METHODS: Uphill and downhill gait of 15 healthy participants was assessed during walking on a treadmill and on a ramp with slope gradients of 12 °, 6 ° and 0 °. Participants were instructed to walk with the same speed on each slope-system. Kinematic and temporo-spatial paramters were collected using a 3D motion capture system (Qualisys, Gothenburgh, Sweden), kinetic data were collected using pressure insoles (loadsol®, Novel, Germany). Temporo-spatial parameters were analysed using a Friedman ANOVA, time series of kinematic and kinetic data were compared using statistical parametric mapping with a sigificance level of 5%. RESULTS: On the treadmill participants walked with significantly shorter steps and shorter contact times, while they significantly increased step frequency compared to walking on a ramp, regardless of slope gradient. In uphill conditions, treadmill gait increased hip and knee flexion angles during the stance phase and increased the forward tilt of the thorax during the entire gait cycle. During downhill walking a significant decrease in dorsiflexion during initial contact, midstance and the second half of the swing phase was observed. Peak resultant forces remained similar compared to walking on the ramp. These alterations might be due to mechanical and psychological effects. SIGNIFICANCE: Knowledge about these differences is important in future study design and data interpretation from existing literature.

Analysis of sloped gait: How many steps are needed to reach steady-state walking speed after gait initiation?

BACKGROUND: Gait initiation in level walking is suggested to take three steps before reaching steady-state walking speed. In sloped gait, it is not clear if the general recommendation of level gait can be used. RESEARCH QUESTION: The aim of this study was to investigate (1) if steady-state walking speed is reached within four steps in sloped gait, and (2) to what extent the number of initial steps cause differences in step length, cadence and ground reaction force (GRF). METHODS: Fourteen healthy participants walked on an instrumented ramp at inclinations of 0°, ±6°, ±12°, and ±18°, covering slight (clinical application) to steep (hiking and mountaineering) slopes. The starting position on the ramp was adjusted to collect each of the first to fourth step using a 12 infrared-camera motion capture system and two force plates. For each slope condition steady-state walking speed was determined using the ratio of the braking and propulsion impulse (ratio pap;pbrakingppropulsion) and the resultant Centre of Mass (CoM) speed (velCoM). Statistical differences between steps were calculated by using a Friedman ANOVA and pairwise post-hoc Wilcoxon tests. RESULTS: In all inclinations, ≥90 % (uphill) and ≥95 % (downhill) of steady-state speed regarding ratio pap and maximum velCoM was reached with the 3rd step. In the level and uphill condition the 4th step showed a slight decrease in velCoM. In uphill and downhill condition, the acceleration was mainly generated due to the increase in cadence with significant increases between the 1st and 2nd step as well as between the 2nd and 3rd step. A significant increase in step length was only observed in the uphill conditions. SIGNIFICANCE: Steady-state walking speed was reached with the 3rd step and thus, walkways which allow for two initial steps seem to be appropriate for uphill and downhill gait analysis for inclinations up to ±18°.

Hepatitis E virus infections in HIV-infected patients in Ghana and Cameroon.

BACKGROUND: Chronic hepatitis E virus (HEV) infections have recently been described in HIV-infected patients. Only few data are available for sub-Saharan Africa, where HIV and HEV are highly co-endemic, and where liver pathology is common in HIV-infected individuals. OBJECTIVES: To assess the prevalence of HEV viremia, anti-HEV antibodies, and serum aminotransferase levels in HIV patients in Ghana and Cameroon. STUDY DESIGN: We retrospectively surveyed a cross-section of patients who were enrolled in cohort studies in Ghana (West Africa), and Cameroon (Central Africa). Plasma samples from 1029 HIV patients from Ghana and 515 patients from Cameroon including 214 children were analyzed for HEV-RNA by two reverse transcription PCR methods. In a subset of 791 patients, anti-HEV IgG and IgM antibodies were analyzed. RESULTS: No HEV-RNA was detected in any of the plasma samples of 1544 patients. HEV seroprevalence was high in adult HIV patients from Ghana (45.3%, n=402) and Cameroon (14.2%, n=289), but low in pediatric HIV patients from Cameroon (2.0%, n=100). Elevations of alanine aminotransferase and aspartate aminotransferase levels were common in adult patients from Ghana (20.8% and 25.4%) and Cameroon (38.9% and 69.8%). The prevalence of hepatitis B virus surface antigen was 11.8% and of hepatitis C virus antibodies 2.5% in our adult Cameroonian study population. CONCLUSIONS: Acute or chronic HEV infections did not play a role in liver pathology in two HIV cohorts in Ghana and Cameroon. A better understanding of the epidemiology and genotype-specific characteristics of HEV infections in HIV patients in sub-Saharan Africa is needed.