797 research outputs found
Role of calcium supplementation during pregnancy in reducing risk of developing gestational hypertensive disorders: a meta-analysis of studies from developing countries
Background:Hypertension in pregnancy stand alone or with proteinuria is one of the leading causes of maternal mortality and morbidity in the world. Epidemiological and clinical studies have shown that an inverse relationship exists between calcium intake and development of hypertension in pregnancy though the effect varies based on baseline calcium intake and pre-existing risk factors. The Purpose of this review was to evaluate preventive effect of calcium supplementation during pregnancy on gestational hypertensive disorders and related maternal and neonatal mortality in developing countries.Methods: A literature search was carried out on PubMed, Cochrane Library and WHO regional databases. Data were extracted into a standardized excel sheet. Identified studies were graded based on strengths and limitations of studies. All the included studies were from developing countries. Meta-analyses were generated where data were available from more than one study for an outcome. Primary outcomes were maternal mortality, eclampsia, pre-eclampsia, and severe preeclampsia. Neonatal outcomes like neonatal mortality, preterm birth, small for gestational age and low birth weight were also evaluated. We followed standardized guidelines of Child Health Epidemiology Reference Group (CHERG) to generate estimates of effectiveness of calcium supplementation during pregnancy in reducing maternal and neonatal mortality in developing countries, for inclusion in the Lives Saved Tool (LiST).Results: Data from 10 randomized controlled trials were included in this review. Pooled analysis showed that calcium supplementation during pregnancy was associated with a significant reduction of 45% in risk of gestational hypertension [Relative risk (RR) 0.55, 95 % confidence interval (CI) 0.36-0.85] and 59% in the risk of preeclampsia [RR 0.41, 95 % CI 0.24-0.69] in developing countries. Calcium supplementation during pregnancy was also associated with a significant reduction in neonatal mortality [RR 0.70, 95 % CI 0.56-0.88] and risk of pre-term birth [RR 0.88, 95 % CI 0.78-0.99]. Recommendations for LiST for reduction in maternal mortality were based on risk reduction in gestational hypertensive related severe morbidity/mortality [RR 0.80, 95% CI 0.70-0.91] and that for neonatal mortality were based on risk reduction in all-cause neonatal mortality [RR 0.70, 95% CI 0.56-0.88].Conclusion: Calcium supplementation during pregnancy is associated with a reduction in risk of gestational hypertension, pre-eclampsia neonatal mortality and pre-term birth in developing countries
Intravenous Vitamin C Administered as Adjunctive Therapy for Recurrent Acute Respiratory Distress Syndrome
This case report summarizes the first use of intravenous vitamin C employed as an adjunctive interventional agent in the therapy of recurrent acute respiratory distress syndrome (ARDS). The two episodes of ARDS occurred in a young female patient with Cronkhite-Canada syndrome, a rare, sporadically occurring, noninherited disorder that is characterized by extensive gastrointestinal polyposis and malabsorption. Prior to the episodes of sepsis, the patient was receiving nutrition via chronic hyperalimentation administered through a long-standing central venous catheter. The patient became recurrently septic with Gram positive cocci which led to two instances of ARDS. This report describes the broad-based general critical care of a septic patient with acute respiratory failure that includes fluid resuscitation, broad-spectrum antibiotics, and vasopressor support. Intravenous vitamin C infused at 50 mg per kilogram body weight every 6 hours for 96 hours was incorporated as an adjunctive agent in the care of this patient. Vitamin C when used as a parenteral agent in high doses acts “pleiotropically” to attenuate proinflammatory mediator expression, to improve alveolar fluid clearance, and to act as an antioxidant
Efficacy of memantine in treating patients with migraine and tension-type headache
Objective: To assess the efficacy of Memantine as a preventive and therapeutic intervention for migraine and tension-type headache.
Methods: This clinical trial was conducted over a period of 3 months. A total of 44 subjects, with diagnosed migraine and/or tension-type headache, presenting to a private neurology clinic in Karachi, Pakistan were selected through purposive sampling technique. Patients were treated with incremental doses of Memantine. Adult patients belonging to both genders were included in the study. Data was analyzed using SPSS version 16.0 and associations were made using Chi square test with p-value of less than 0.05 taken as significant.
Results: Out of 44 patients, 35 (79.5%) were females and 9 (20.5%) were males which shows a very high occurrence of migraine and tension-type headache in females. Average age was found to be 32.6 ≈ 33 years. Efficacy of the drug was observed to be 81.8% which is significantly high. The baseline MIDAS score when compared with the score at 3-month follow-up by applying Wilcoxon signed rank test showed mean ± S.D (39.52±21.27 vs. 6.72±6.41) where p=0.000 (\u3c0.05) which shows a highly significant result. All 44 patients were known cases of migraine while 25% (11) of them also suffered from tension-type headache. Patients were treated with incremental doses of Memantine and were observed for the efficacy of the drug. Patients maintained their diaries of intensity of pain, distressing influence of the pain and how it hindered their daily routine. Results showed that intensity of pain decreased significantly by the end of the 3rd month of treatment and majority of the patients felt less distressed on their final follow-up visit. By the end of the 3rd month, the level of hindrance in the daily routines of the patients caused by the headache also fell significantly.
Conclusion: Memantine has significant beneficial effects in reducing intensity of pain and disability in patients with migraine and tension type headache
Silicon slow-light-based photonic mixer for microwave-frequencyconversion applications
This paper was published in OPTICS LETTERS and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://dx.doi.org/10.1364/OL.37.001721. Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law[EN] We describe and demonstrate experimentally a method for photonic mixing of microwave signals by using a silicon electro-optical Mach¿Zehnder modulator enhanced via slow-light propagation. Slow light with a group index of ~11, achieved in a one-dimensional periodic structure, is exploited to improve the upconversion performance of an input frequency signal from 1 to 10.25 GHz. A minimum transmission point is used to successfully demonstrate the upconversion with very low conversion losses of ~7¿¿dB and excellent quality of the received I/Q modulated QPSK signal with an optimum EVM of ~8%.Financial support from FP7-224312 HELIOS project and Generalitat Valenciana under PROMETEO-2010-087 R&D Excellency Program (NANOMET) are acknowledged. F. Y.Gardes, D. J. Thomson, and G. T. Reed are supported by funding received from the UK EPSRC funding body under the grant “UK Silicon Photonics.” The author A. M. Gutiérrez thanks D. Marpaung for his useful
help.Gutiérrez Campo, AM.; Brimont, ACJ.; Herrera Llorente, J.; Aamer, M.; Martí Sendra, J.; Thomson, DJ.; Gardes, FY.... (2012). Silicon slow-light-based photonic mixer for microwave-frequencyconversion applications. Optics Letters. 37(10):1721-1723. https://doi.org/10.1364/OL.37.001721S17211723371
Preventive zinc supplementation for children, and the effect of additional iron: a systematic review and meta-analysis
Objective: Zinc deficiency is widespread, and preventive supplementation may have benefits in young children. Effects for children over 5 years of age, and effects when coadministered with other micronutrients are uncertain. These are obstacles to scale-up. This review seeks to determine if preventive supplementation reduces mortality and morbidity for children aged 6 months to 12 years. Design: Systematic review conducted with the Cochrane Developmental, Psychosocial and Learning Problems Group. Two reviewers independently assessed studies. Meta-analyses were performed for mortality, illness and side effects. Data sources We searched multiple databases, including CENTRAL and MEDLINE in January 2013. Authors were contacted for missing information. Eligibility criteria for selecting studies Randomised trials of preventive zinc supplementation. Hospitalised children and children with chronic diseases were excluded. Results: 80 randomised trials with 205 401 participants were included. There was a small but non-significant effect on all-cause mortality (risk ratio (RR) 0.95 (95% CI 0.86 to 1.05)). Supplementation may reduce incidence of all-cause diarrhoea (RR 0.87 (0.85 to 0.89)), but there was evidence of reporting bias. There was no evidence of an effect of incidence or prevalence of respiratory infections or malaria. There was moderate quality evidence of a very small effect on linear growth (standardised mean difference 0.09 (0.06 to 0.13)) and an increase in vomiting (RR 1.29 (1.14 to 1.46)). There was no evidence of an effect on iron status. Comparing zinc with and without iron cosupplementation and direct comparisons of zinc plus iron versus zinc administered alone favoured cointervention for some outcomes and zinc alone for other outcomes. Effects may be larger for children over 1 year of age, but most differences were not significant. Conclusions: Benefits of preventive zinc supplementation may outweigh any potentially adverse effects in areas where risk of zinc deficiency is high. Further research should determine optimal intervention characteristics and delivery strategies
Resistance to simian immunodeficiency virus low dose rectal challenge is associated with higher constitutive TRIM5α expression in PBMC
Background: At least six host-encoded restriction factors (RFs), APOBEC3G, TRIM5α, tetherin, SAMHD1, schlafen 11, and Mx2 have now been shown to inhibit HIV and/or SIV replication in vitro. To determine their role in vivo in the resistance of macaques to mucosally-acquired SIV, we quantified both pre-exposure (basal) and post-exposure mRNA levels of these RFs, Mx1, and IFNγ in PBMC, lymph nodes, and duodenum of rhesus macaques undergoing weekly low dose rectal exposures to the primary isolate, SIV/DeltaB670. Results: Repetitive challenge divided the monkeys into two groups with respect to their susceptibility to infection: highly susceptible (2–3 challenges, 5 monkeys) and poorly susceptible (≥6 challenges, 3 monkeys). Basal RF and Mx1 expression varied among the three tissues examined, with the lowest expression generally detected in duodenal tissues, and the highest observed in PBMC. The one exception was A3G whose basal expression was greatest in lymph nodes. Importantly, significantly higher basal expression of TRIM5α and Mx1 was observed in PBMC of animals more resistant to mucosal infection. Moreover, individual TRIM5α levels were stable throughout a year prior to infection. Post-exposure induction of these genes was also observed after virus appearance in plasma, with elevated levels in PBMC and duodenum transiently occurring 7–10 days post infection. They did not appear to have an effect on control of viremia. Interestingly, minimal to no induction was observed in the resistant animal that became an elite controller. Conclusions: These results suggest that constitutively expressed TRIM5α appears to play a greater role in restricting mucosal transmission of SIV than that associated with type I interferon induction following virus entry. Surprisingly, this association was not observed with the other RFs. The higher basal expression of TRIM5α observed in PBMC than in duodenal tissues emphasizes the understated role of the second barrier to systemic infection involving the transport of virus from the mucosal compartment to the blood. Together, these observations provide a strong incentive for a more comprehensive examination of the intrinsic, variable control of constitutive expression of these genes in the sexual transmission of HIV
Effectiveness of interventions to screen and manage infections during pregnancy on reducing stillbirths: a review
Abstract
Background
Infection is a well acknowledged cause of stillbirths and may account for about half of all perinatal deaths today, especially in developing countries. This review presents the impact of interventions targeting various important infections during pregnancy on stillbirth or perinatal mortality.
Methods
We undertook a systematic review including all relevant literature on interventions dealing with infections during pregnancy for assessment of effects on stillbirths or perinatal mortality. The quality of the evidence was assessed using the adapted Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach by Child Health Epidemiology Reference Group (CHERG). For the outcome of interest, namely stillbirth, we applied the rules developed by CHERG to recommend a final estimate for reduction in stillbirth for input to the Lives Saved Tool (LiST) model.
Results
A total of 25 studies were included in the review. A random-effects meta-analysis of observational studies of detection and treatment of syphilis during pregnancy showed a significant 80% reduction in stillbirths [Relative risk (RR) = 0.20; 95% confidence interval (CI): 0.12 - 0.34) that is recommended for inclusion in the LiST model. Our meta-analysis showed the malaria prevention interventions i.e. intermittent preventive treatment (IPTp) and insecticide-treated mosquito nets (ITNs) can reduce stillbirths by 22%, however results were not statistically significant (RR = 0.78; 95% CI: 0.59 – 1.03). For human immunodeficiency virus infection, a pooled analysis of 6 radomized controlled trials (RCTs) failed to show a statistically significant reduction in stillbirth with the use of antiretroviral in pregnancy compared to placebo (RR = 0.93; 95% CI: 0.45 – 1.92). Similarly, pooled analysis combining four studies for the treatment of bacterial vaginosis (3 for oral and 1 for vaginal antibiotic) failed to yield a significant impact on perinatal mortality (OR = 0.88; 95% CI: 0.50 – 1.55).
Conclusions
The clearest evidence of impact in stillbirth reduction was found for adequate prevention and treatment of syphilis infection and possibly malaria. At present, large gaps exist in the growing list of stillbirth risk factors, especially those that are infection related. Potential causes of stillbirths including HIV and TORCH infections need to be investigated further to help establish the role of prevention/treatment and its subsequent impact on stillbirth reduction.
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The effect of providing skilled birth attendance and emergency obstetric care in preventing stillbirths
Abstract
Background
Of the global burden of 2.6 million stillbirths, around 1.2 million occur during labour i.e. are intrapartum deaths. In low-/middle-income countries, a significant proportion of women give birth at home, usually in the absence of a skilled birth attendant. This review discusses the impact of skilled birth attendance (SBA) and the provision of Emergency Obstetric Care (EOC) on stillbirths and perinatal mortality.
Methods
A systematic literature search was performed on PubMed/MEDLINE, Cochrane Database and the WHO regional libraries. Data of all eligible studies were extracted into a standardized Excel sheet containing variables such as participants’ characteristics, sample size, location, setting, blinding, allocation concealment, intervention and control details and limitations. We undertook a meta-analysis of the impact of SBA on stillbirths. Given the paucity of data from randomized trials or robust quasi-experimental designs, we undertook an expert Delphi consultation to determine impact estimates of provision of Basic and Comprehensive EOC on reducing stillbirths if there would be universal coverage (99%).
Results
The literature search yielded 871 hits. A total of 21 studies were selected for data abstraction. Our meta-analysis on community-based skilled birth attendance based on two before-after studies showed a 23% significant reduction in stillbirths (RR = 0.77; 95% CI: 0.69 – 0.85). The overall quality grade of available evidence for this intervention on stillbirths was ‘moderate’. The Delphi process supported the estimated reduction in stillbirths by skilled attendance and experts further suggested that the provision of Basic EOC had the potential to avert intrapartum stillbirths by 45% and with provision of Comprehensive EOC this could be reduced by 75%. These estimates are conservative, consistent with historical trends in maternal and perinatal mortality from both developed and developing countries, and are recommended for inclusion in the Lives Saved Tool (LiST) model.
Conclusions
Both Skilled Birth Attendance and Emergency/or Essential Obstetric Care have the potential to reduce the number of stillbirths seen globally. Further evidence is needed to be able to calculate an effect size.
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