Does Caesarean Section Affect Breastfeeding Practices in China? A Systematic Review and Meta-Analysis

Abstract

Objectives To ascertain the association between caesarean delivery and breastfeeding practices in China. Methods We conducted a systematic review and meta-analysis following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Meta-analysis Of Observational Studies in Epidemiology (MOOSE) guidelines. Electronic databases of CNKI, Medline, EMBASE, CINAHL, ProQuest and Science Direct were searched and screened to identify relevant articles from January 1990 to June 2015. Both fixed and random effect meta-analysis techniques were used to estimate the pooled effect size between caesarean delivery and breastfeeding outcomes at different time points. Sensitivity analysis and publication bias test were also conducted. Results Forty six studies were eligible for the qualitative synthesis of systematic review; among them, 27 studies were included for the meta-analysis. At the early postpartum period, the odds of exclusive breastfeeding after caesarean section was 47% (pooled OR 0.53, 95% CI 0.41, 0.68) lower than that after vaginal delivery. At 4 months postpartum, the odds of breastfeeding was similarly lower (pooled OR 0.61, 95% CI 0.53, 0.71) for caesarean mothers. Substantial heterogeneity among studies was detected for both breastfeeding outcomes. Subgroup analyses stratified by study design, time points of breastfeeding outcomes and definitions of breastfeeding all confirmed the negative association between caesarean section and breastfeeding prevalence. Conclusions In China, breastfeeding practices were affected adversely by caesarean delivery. Therefore, health policy to improve breastfeeding outcomes should take this into consideration.

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Impacting Entry into Evidence-Based Supported Employment: A Population-Based Empirical Analysis of a Statewide Public Mental Health Program in Maryland

Abstract

We use discrete-time survival regression to study two empirical issues relating to take-up of individual placement and support (IPS) supported employment (SE) services for persons with serious mental illness: (1) the influence of client characteristics on take-up probability, and (2) the possible impacts of a major recent initiative in one state (Maryland) to overcome barriers to IPS-SE expansion. Our longitudinal analysis of population-based Medicaid cohorts, during 2002–2010, provides tentative evidence of positive state initiative impacts on SE take-up rates, and evidence of effects on take-up for clients' diagnoses, prior work-history, health and demographic characteristics, and geographic accessibility to SE providers.

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The corticospinal responses of metronome-paced, but not self-paced strength training are similar to motor skill training

Abstract

Purpose

The corticospinal responses to skill training may be different to strength training, depending on how the strength training is performed. It was hypothesised that the corticospinal responses would not be different following skill training and metronome-paced strength training (MPST), but would differ when compared with self-paced strength training (SPST).

Methods

Corticospinal excitability, short-interval intra-cortical inhibition (SICI) and strength and tracking error were measured at baseline and 2 and 4 weeks. Participants (n = 44) were randomly allocated to visuomotor tracking, MPST, SPST or a control group.

Results

MPST increased strength by 7 and 18%, whilst SPST increased strength by 12 and 26% following 2 and 4 weeks of strength training. There were no changes in strength following skill training. Skill training reduced tracking error by 47 and 58% at 2 and 4 weeks. There were no changes in tracking error following SPST; however, tracking error reduced by 24% following 4 weeks of MPST. Corticospinal excitability increased by 40% following MPST and by 29% following skill training. There was no change in corticospinal excitability following 4 weeks of SPST. Importantly, the magnitude of change between skill training and MPST was not different. SICI decreased by 41 and 61% following 2 and 4 weeks of MPST, whilst SICI decreased by 41 and 33% following 2 and 4 weeks of skill training. Again, SPST had no effect on SICI at 2 and 4 weeks. There was no difference in the magnitude of SICI reduction between skill training and MPST.

Conclusions

This study adds new knowledge regarding the corticospinal responses to skill and MPST, showing they are similar but different when compared with SPST.

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The importance of cutaneous feedback on neural activation during maximal voluntary contraction

Abstract

Purpose

The purpose of this study was to investigate the importance of cutaneous feedback on neural activation during maximal voluntary contraction (MVC) of the ankle plantar flexors.

Methods

The effects of cutaneous plantar anaesthesia were assessed in 15 subjects and compared to 15 controls, using a one-day pre/post-repeated measures design. Cutaneous plantar anaesthesia was induced by lidocaine injection at the centre of forefoot, lateral midfoot, and heel. Each subject performed isometric MVCs of the ankle plantar flexors. During each isometric ramp contraction, the following variables were assessed: maximal isometric torque; surface electromyography (EMG) activity of the medial gastrocnemius (MG) and tibialis anterior (TA) muscles; and co-contraction index (CCI) between the MG and TA.

Results

For ankle torque, two-way ANOVA showed no significant interaction between the pre/post-measurements × group (p = 0.166). However, MG activity presented significant interactions between the pre/post-measurements × group (p = 0.014). Post hoc comparisons indicated a decrease of MG activity in the experimental group, from 85.9 ± 11.9 to 62.7 ± 30.8% (p = 0.016). Additionally, the post-anaesthesia MG activity of the experimental group differed statistically with pre- and post-MG activity of the control group (p = 0.027 and p = 0.008, respectively). For TA activity and CCI, two-way ANOVA detected no significant interactions between the pre/post-measurements × group (p = 0.605 and p = 0.332, respectively).

Conclusion

Our results indicate that during MVC, cutaneous feedback modulates neural activity to MG muscle, without changing the extent of MG–TA co-contraction.

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Effects of prior aerobic exercise on sitting-induced vascular dysfunction in healthy men

Abstract

Introduction

Acute aerobic exercise prevents sitting-induced impairment of flow-mediated dilation (FMD). Further, evidence suggests that sitting-induced impairment of FMD occurs via an oxidative stress-dependent mechanism that disrupts endothelial function.

Purpose

We hypothesized that acute aerobic exercise would prevent impairment of femoral artery FMD by limiting oxidative stress responses that increase endothelin-1 (ET-1) levels and disrupt nitric oxide (NO) status.

Methods

In a randomized, cross-over study, healthy men (n = 11; 21.2 ± 1.9 years) completed two 3 h sitting trials that were preceded by 45 min of either quiet rest (REST) or a single bout of continuous treadmill exercise (65% maximal oxygen consumption) (EX). Superficial femoral artery FMD, plasma glucose, malondialdehyde (MDA), ET-1, arginine (ARG) and its related metabolites [homoarginine (HA), asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA)] were assessed at baseline, 1 h following EX (or REST) (0 h), and at 1 h intervals during 3 h of uninterrupted sitting. Data were analyzed using repeated measures ANOVA.

Results

During REST, femoral artery FMD declined from baseline (2.6 ± 1.8%) at 1, 2, and 3 h of sitting and resting shear rate decreased at 3 h. In contrast, when sitting was preceded by EX, femoral artery FMD (2.7 ± 2.0%) and resting shear rate responses were unaffected. No between trial differences were detected for plasma glucose, MDA, ET-1, ARG, HA, ADMA, or SDMA.

Conclusion

Prior aerobic exercise prevented the decline in femoral artery FMD that is otherwise induced by prolonged sitting independent of changes in oxidative stress, ET-1, and NO status.

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Calcium and electrical dynamics in lymphatic endothelium

Abstract

Subsequent to a rise in intracellular Ca²⁺ ([Ca²⁺]_i), hyperpolarization of the endothelium coordinates vascular smooth muscle relaxation along resistance arteries during blood flow control. In the lymphatic vasculature, collecting vessels generate rapid contractions coordinated along lymphangions to propel lymph, but the underlying signalling pathways are unknown. We tested the hypothesis that lymphatic endothelial cells (LECs) exhibit Ca²⁺ and electrical signalling properties that facilitate lymph propulsion. To study electrical and intracellular Ca²⁺ signalling dynamics in lymphatic endothelium, we excised collecting lymphatic vessels from the popliteal fossa of mice and removed their muscle cells to isolate intact LEC tubes (LECTs). Intracellular recording revealed a resting membrane potential of ∼−70 mV. Acetylcholine (ACh) increased [Ca²⁺]_i with a time course similar to that observed in endothelium of resistance arteries (i.e. rapid initial peak with a sustained "plateau"). In striking contrast to the endothelium-derived hyperpolarization (EDH) characteristic of arteries, LECs depolarized (>15 mV) to either ACh or TRPV4 channel activation. This depolarization was facilitated by the absence of Ca²⁺-activated K⁺ channels (K_Ca) as confirmed with PCR, persisted in the absence of extracellular Ca²⁺, was abolished by LaCl₃ and was attenuated ∼70% in LECTs from Trpv4^−/− mice. Computational modelling of ion fluxes in LECs indicated that omitting K⁺ channels supports our experimental results. These findings reveal novel signalling events in LECs, which are devoid of the K_Ca activity abundant in arterial endothelium. Absence of EDH with effective depolarization of LECs may promote the rapid conduction of contraction waves along lymphatic muscle during lymph propulsion.

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Radiation, radionuclides and bacteria: An in-perspective review

Publication date: December 2017
Source:Journal of Environmental Radioactivity, Volume 180
Author(s): Arpit Shukla, Paritosh Parmar, Meenu Saraf
There has been a significant surge in consumption of radionuclides for various academic and commercial purposes. Correspondingly, there has been a considerable amount of generation of radioactive waste. Bacteria and archaea, being earliest inhabitants on earth serve as model microorganisms on earth. These microbes have consistently proven their mettle by surviving extreme environments, even extreme ionizing radiations. Their ability to accept and undergo stable genetic mutations have led to development of recombinant mutants that are been exploited for remediation of various pollutants such as; heavy metals, hydrocarbons and even radioactive waste (radwaste). Thus, microbes have repeatedly presented themselves to be prime candidates suitable for remediation of radwaste. It is interesting to study the behind-the-scenes interactions these microbes possess when observed in presence of radionuclides. The emphasis is on the indigenous bacteria isolated from radionuclide containing environments as well as the five fundamental interaction mechanisms that have been studied extensively, namely; bioaccumulation, biotransformation, biosorption, biosolubilisation and bioprecipitation. Application of microbes exhibiting such mechanisms in remediation of radioactive waste depends largely on the individual capability of the species. Challenges pertaining to its potential bioremediation activity is also been briefly discussed. This review provides an insight into the various mechanisms bacteria uses to tolerate, survive and carry out processes that could potentially lead the eco-friendly approach for removal of radionuclides.

Graphical abstract

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