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Journal of Reproduction & Infertility 2023Cell-free fetal DNA (cffDNA) is a novel screening method for fetal aneuploidy that facilitated non-invasive prenatal testing (NIPT) through analysis of cffDNA in... (Review)
Review
BACKGROUND
Cell-free fetal DNA (cffDNA) is a novel screening method for fetal aneuploidy that facilitated non-invasive prenatal testing (NIPT) through analysis of cffDNA in maternal plasma. However, despite increased sensitivity, it has a number of limitations that may complicate of its results interpretation. Therefore, elucidating factors affecting fetal fraction, as a critical limitation, guides its clinical application.
METHODS
In this report, systematic search was carried out through PubMed, Web of Science, and Scopus databases until February 11, 2022 by using keywords consist of "noninvasive prenatal screening", "NIPT", "noninvasive prenatal", "cell free DNA" and "fetal fraction". The articles were screened for eligibility criteria before data extraction.
RESULTS
A total of 39 eligible studies, most published between 2010 and 2020, were included. Based on the results of studies, a negative correlation between maternal age and BMI/body weight with fetal fraction was found. Furthermore, LDL, cholesterol, triglyceride level, metformin, heparin and enoxaparin therapy, hemoglobin-related hemoglobinopathies, and physical activity showed to have negative associations. Interestingly, it seems the ethnicity of patients from South and East Asia has a correlation with fetal fraction compared to Caucasians. Positive correlation was observed between gestational age, free β-hCG, PAPP-A, living in high altitude, and twin pregnancy.
CONCLUSION
Considering each factor, there was significant inconsistency and controversy regarding their impact on outcomes. Indeed, multiple factors can influence the accuracy of NIPS results, and it is worth noting that the impact of these factors may vary depending on the individual's ethnic background. Therefore, it is important to recognize that NIPS remains a screening test, and comprehensive pre- and post-NIPS counseling should be conducted as part of standard clinical practice.
PubMed: 38164433
DOI: 10.18502/jri.v24i4.14149 -
Toxins Nov 2023Colombia encompasses three mountain ranges that divide the country into five natural regions: Andes, Pacific, Caribbean, Amazon, and Orinoquia. These regions offer an... (Review)
Review
Colombia encompasses three mountain ranges that divide the country into five natural regions: Andes, Pacific, Caribbean, Amazon, and Orinoquia. These regions offer an impressive range of climates, altitudes, and landscapes, which lead to a high snake biodiversity. Of the almost 300 snake species reported in Colombia, nearly 50 are categorized as venomous. This high diversity of species contrasts with the small number of studies to characterize their venom compositions and natural history in the different ecoregions. This work reviews the available information about the venom composition, isolated toxins, and potential applications of snake species found in Colombia. Data compilation was conducted according to the PRISMA guidelines, and the systematic literature search was carried out in Pubmed/MEDLINE. Venom proteomes from nine Viperidae and three Elapidae species have been described using quantitative analytical strategies. In addition, venoms of three Colubridae species have been studied. Bioactivities reported for some of the venoms or isolated components-such as antibacterial, cytotoxicity on tumoral cell lines, and antiplasmodial properties-may be of interest to develop potential applications. Overall, this review indicates that, despite recent progress in the characterization of venoms from several Colombian snakes, it is necessary to perform further studies on the many species whose venoms remain essentially unexplored, especially those of the poorly known genus .
Topics: Animals; Colombia; Snake Venoms; Elapidae; Toxins, Biological; Coral Snakes; Elapid Venoms
PubMed: 37999521
DOI: 10.3390/toxins15110658 -
Clinical Autonomic Research : Official... Dec 2023This systematic review aimed to summarize how oral contraceptives (OC) affect resting autonomic function and the autonomic response to a variety of physiological...
PURPOSE
This systematic review aimed to summarize how oral contraceptives (OC) affect resting autonomic function and the autonomic response to a variety of physiological stressors.
METHODS
A search strategy was created to retrieve citations investigating physiological responses comparing OC users to non-users (NOC) in response to autonomic reflex activation.
RESULTS
A total of 6148 citations were identified across databases from inception to June 2, 2022, and 3870 citations were screened at the abstract level after deduplication. Then, 133 texts were assessed at full-text level, and only 40 studies met eligibility requirements. Included citations were grouped by the aspect of autonomic function assessed, including autonomic reflex (i.e., baroreflex, chemoreflex, mechanoreflex, metaboreflex, and venoarterial reflex), or indicators (i.e., heart rate variability, pulse wave velocity, and sympathetic electrodermal activity), and physiological stressors that may alter autonomic function (i.e., auditory, exercise, mental or orthostatic stress, altitude, cold pressor test, sweat test, and vasodilatory infusions).
CONCLUSION
OC influence the physiological responses to chemoreflex, mechanoreflex, and metaboreflex activation. In terms of autonomic indices and physiological stressors, there are more inconsistencies within the OC literature, which may be due to estrogen dosage within the OC formulation (i.e., heart rate variability) or the intensity of the stressor (exercise intensity/duration or orthostatic stress). Further research is required to elucidate the effects of OC on these aspects of autonomic function because of the relatively small amount of available research. Furthermore, researchers should more clearly define or stratify OC use by duration, dose, and/or hormone cycling to further elucidate the effects of OC.
Topics: Female; Humans; Contraceptives, Oral; Pulse Wave Analysis; Blood Pressure; Autonomic Nervous System; Hypotension
PubMed: 37971640
DOI: 10.1007/s10286-023-00996-0 -
Frontiers in Physiology 2023Acute exposure to hypoxia can lead to cognitive impairment. Therefore, hypoxia may become a safety concern for occupational or recreational settings at altitude....
Acute exposure to hypoxia can lead to cognitive impairment. Therefore, hypoxia may become a safety concern for occupational or recreational settings at altitude. Cognitive tests are used as a tool to assess the degree to which hypoxia affects cognitive performance. However, so many different cognitive tests are used that comparing studies is challenging. This structured literature evaluation provides an overview of the different cognitive tests used to assess the effects of acute hypoxia on cognitive performance in healthy volunteers. Less frequently used similar cognitive tests were clustered and classified into domains. Subsequently, the different cognitive test clusters were compared for sensitivity to different levels of oxygen saturation. A total of 38 articles complied with the selection criteria, covering 86 different cognitive tests. The tests and clusters showed that the most consistent effects of acute hypoxia were found with the Stroop test (where 42% of studies demonstrated significant abnormalities). The most sensitive clusters were auditory/verbal memory: delayed recognition (83%); evoked potentials (60%); visual/spatial delayed recognition (50%); and sustained attention (47%). Attention tasks were not particularly sensitive to acute hypoxia (impairments in 0%-47% of studies). A significant hypoxia level-response relationship was found for the Stroop test ( = 0.001), as well as three clusters in the executive domain: inhibition ( = 0.034), reasoning/association ( = 0.019), and working memory ( = 0.024). This relationship shows a higher test sensitivity at more severe levels of hypoxia, predominantly below 80% saturation. No significant influence of barometric pressure could be identified in the limited number of studies where this was varied. This review suggests that complex and executive functions are particularly sensitive to hypoxia. Moreover, this literature evaluation provides the first step towards standardization of cognitive testing, which is crucial for a better understanding of the effects of acute hypoxia on cognition.
PubMed: 37885803
DOI: 10.3389/fphys.2023.1244279 -
Journal of Exercise Science and Fitness Oct 2023Enhancement in maximal oxygen consumption (VO) induced by hypoxic training is important for both athletes and non-athletes. However, the lack of comparison of multiple... (Review)
Review
BACKGROUND
Enhancement in maximal oxygen consumption (VO) induced by hypoxic training is important for both athletes and non-athletes. However, the lack of comparison of multiple paradigms and the exploration of related modulating factors leads to the inability to recommend the optimal regimen in different situations. This study aimed to investigate the efficacy of seven common hypoxic training paradigms on VO and associated moderators.
METHODS
Electronic (i.e., five databases) and manual searches were performed, and 42 studies involving 1246 healthy adults were included. Pairwise meta-analyses were conducted to compare different hypoxic training paradigms and hypoxic training and control conditions. The Bayesian network meta-analysis model was applied to calculate the standardised mean differences (SMDs) of pre-post VO alteration among hypoxic training paradigms in overall, athlete, and non-athlete populations, while meta-regression analyses were employed to explore the relationships between covariates and SMDs.
RESULTS
All seven hypoxic training paradigms were effective to varying degrees, with SMDs ranging from 1.45 to 7.10. Intermittent hypoxia interval training (IHIT) had the highest probability of being the most efficient hypoxic training paradigm in the overall population and athlete subgroup (42%, 44%), whereas intermittent hypoxic training (IHT) was the most promising hypoxic training paradigm among non-athletes (66%). Meta-regression analysis revealed that saturation hours (coefficient, 0.004; = 0.038; 95% CI [0.0002, 0.0085]) accounted for variations of VO improvement induced by IHT.
CONCLUSION
Efficient hypoxic training paradigms for VO gains differed between athletes and non-athletes, with IHIT ranking best for athletes and IHT for non-athletes. The practicability of saturation hours is confirmed with respect to dose-response issues in the future hypoxic training and associated scientific research.
REGISTRATION
This study was registered in the PROSPERO international prospective register of systematic reviews (CRD42022333548).
PubMed: 37854170
DOI: 10.1016/j.jesf.2023.09.001 -
Infectious Diseases of Poverty Oct 2023Clonorchis sinensis, one of the most important food-borne zoonotic trematodes, remains prevalent in China. Understanding its infection status in animals is crucial for... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Clonorchis sinensis, one of the most important food-borne zoonotic trematodes, remains prevalent in China. Understanding its infection status in animals is crucial for controlling human clonorchiasis. Here we conducted a systematic review and meta-analysis to focus on the spatio-temporal disparities of C. sinensis infection in animals in China.
METHODS
Data on C. sinensis prevalence in snails, the second intermediate hosts, or animal reservoirs in China were extracted from electronic databases including PubMed, Embase, Web of Science, Chinese Wanfang database, CNKI, VIP, and China Biomedical Literature database. A random-effects meta-analysis model was utilized to estimate the pooled prevalence in each of the above animal hosts. Subgroup analysis and multivariable meta-regression were performed to explore potential sources of heterogeneity across studies and compare the temporal disparity of infection rates between high and low epidemic areas. Scatter plots were used to depict the biogeographical characteristics of regions reporting C. sinensis infection in animals.
RESULTS
The overall pooled prevalence of C. sinensis was 0.9% (95% CI: 0.6-1.2%) in snails, 14.2% (12.7-15.7%) in the second intermediate host, and 14.3% (11.4-17.6%) in animal reservoirs. Prevalence in low epidemic areas (with human prevalence < 1%) decreased from 0.6% (0.2-1.2%) before 1990 to 0.0% (0.0-3.6%) after 2010 in snails (P = 0.0499), from 20.3% (15.6-25.3%) to 8.8% (5.6-12.6%) in the second intermediate hosts (P = 0.0002), and from 18.3% (12.7-24.7%) to 4.7% (1.0-10.4%) in animal reservoirs. However, no similar decrease in prevalence was observed in high epidemic areas (with human prevalence ≥ 1.0%). C. sinensis infections were predominantly reported in areas with altitudes below 2346 m and annual cumulative precipitation above 345 mm and were mostly concentrated in eastern China.
CONCLUSIONS
There are spatio-temporal disparities in the animal infections of C. sinensis in different areas of China. Animal infections are primarily concentrated in regions with low altitude and high precipitation. The results suggest that implementing One Health-based comprehensive measures targeting both humans and animals, especially in high epidemic areas, is essential for successful eradication of C. sinensis in China.
Topics: Animals; Humans; Clonorchiasis; Clonorchis sinensis; China; Prevalence; Snails
PubMed: 37845775
DOI: 10.1186/s40249-023-01146-4 -
Current Environmental Health Reports Dec 2023Environmental exposures have been associated with increased risk of cardiovascular mortality and acute coronary events, but their relationship with out-of-hospital... (Review)
Review
PURPOSE OF REVIEW
Environmental exposures have been associated with increased risk of cardiovascular mortality and acute coronary events, but their relationship with out-of-hospital cardiac arrest (OHCA) and sudden cardiac death (SCD) remains unclear. SCD is an important contributor to the global burden of cardiovascular disease worldwide.
RECENT FINDINGS
Current literature suggests a relationship between environmental exposures and cardiovascular disease, but their relationship with OHCA/SCD remains unclear. A literature search was conducted in PubMed, Embase, Web of Science, and Global Health. Of 5138 studies identified by our literature search, this review included 30 studies on air pollution, 42 studies on temperature, 6 studies on both air pollution and temperature, and 1 study on altitude exposure and OHCA/SCD. Particulate matter air pollution, ozone, and both hot and cold temperatures are associated with increased risk of OHCA/SCD. Pollution and other exposures related to climate change play an important role in OHCA/SCD incidence.
Topics: Humans; Temperature; Cross-Over Studies; Air Pollution; Particulate Matter; Death, Sudden, Cardiac; Out-of-Hospital Cardiac Arrest; Environmental Exposure; Air Pollutants
PubMed: 37845484
DOI: 10.1007/s40572-023-00414-7 -
PloS One 2023The objective of this systematic review and meta-analysis was to assess the prevalence of hypertension in populations living at altitude in Latin America and the... (Meta-Analysis)
Meta-Analysis
OBJECTIVE
The objective of this systematic review and meta-analysis was to assess the prevalence of hypertension in populations living at altitude in Latin America and the Caribbean.
METHODS
We conducted a systematic search from January 1, 2000 to January 10, 2023 in Web of Science (WoS)/Core Collection, WoS/Medline, WoS/Scielo, Scopus, PubMed and Embase databases. We included studies that assessed the prevalence of hypertension in altitude populations (>1500 m.a.s.l.) and these were meta-analyzed using a random-effects model. To assess the sources of heterogeneity, we performed subgroup and meta-regression analyses.
RESULTS
Thirty cross-sectional studies (117 406 participants) met the inclusion criteria. Studies used different cut-off points. The prevalence of hypertension in the studies that considered the cut-off point of ≥ 140/90 mmHg in the general population was 19.1%, ≥ 130/85 mmHg was 13.1%, and ≥ 130/80 mmHg was 43.4%. There was a tendency for the prevalence of hypertension to be higher in men. In meta-regression analyses, no association was found between altitude, mean age, year of publication, risk of bias and prevalence of hypertension.
CONCLUSION
The prevalence of hypertension in the altitude population of Latin America and the Caribbean is lower than that reported in populations living at sea level and lower than other altitude populations such as Tibetans.
PROSPERO
CRD42021275229.
Topics: Male; Humans; Adult; Latin America; Prevalence; Altitude; Cross-Sectional Studies; Hypertension; Caribbean Region
PubMed: 37824544
DOI: 10.1371/journal.pone.0292111 -
Heliyon Sep 2023With a growing number of athletes and coaches adopting altitude training, the importance for rationalizing and optimizing such training has been emphasized. We conducted...
PURPOSE
With a growing number of athletes and coaches adopting altitude training, the importance for rationalizing and optimizing such training has been emphasized. We conducted a meta-analysis to evaluate the influence of altitude training on athletes' aerobic capacity and to explore the best altitude training method to improve this capacity.
METHODS
We searched Web of Science, SpringerLink, Science Direct, EBSCO, and PubMed databases combined with manual search of the references to collect studies indexed from 1979 to September 2020 on the effect of altitude training on athletes' aerobic capacity. Data from experimental studies that reported hemoglobin levels and maximum oxygen uptake in athletes before and after altitude training, or in athletes performing altitude training in comparison with a control group were analyzed. Data of the populations, intervention, comparison, outcomes and study design were extracted. Review Manager software 5.3 was used for bias evaluation.
RESULTS
17 publications were included. In our meta-analysis, altitude training led to higher maximum oxygen uptake [standardized mean difference (SMD) = 0.67, 95% confidence interval (CI) 0.35-1.00, P < 0.001] and hemoglobin level (SMD = 0.50, 95% CI 0.11-0.90, P = 0.013) than training at lower altitude. The result of sensitivity analysis showed that results of meta-analysis were relatively stable, and there was no bias or change in the result of effect size according to the bias test. The results of subgroup analysis showed that high-altitude living and low-altitude training ("Hi-Lo" regime), with a training cycle of about three weeks at an altitude around 2500 m, had better effects than other regimes on the athletes' aerobic capacity.
CONCLUSIONS
Altitude training can improve athletes' aerobic capacity in terms of maximum oxygen uptake and hemoglobin level. Our results are limited by the number and quality of available studies. Therefore, more high-quality studies are needed to verify and extend these findings. Our study can provide scientific suggestions for the training of athletes.
PubMed: 37809554
DOI: 10.1016/j.heliyon.2023.e20188 -
High Altitude Medicine & Biology Mar 2024Poudel, Sangeeta, Sandesh Gautam, Purushottam Adhikari, and Ken Zafren. Physiological effects of sildenafil versus placebo at high altitude: a systematic review. .... (Review)
Review
Poudel, Sangeeta, Sandesh Gautam, Purushottam Adhikari, and Ken Zafren. Physiological effects of sildenafil versus placebo at high altitude: a systematic review. . 25:16-25, 2024. High altitude pulmonary edema (HAPE), a life-threatening condition that affects individuals ascending to high altitude, requires the development of pulmonary hypertension. Sildenafil can be used to prevent and treat HAPE, presumably by decreasing pulmonary artery pressure (PaP). We compared the physiological effects of sildenafil versus placebo at high altitude (above 2,500 m), including the effects on PaP. We performed a systematic search of PubMed, EMBASE, and Cochrane CENTRAL for randomized controlled studies of the physiological effects of sildenafil in hypoxia in healthy individuals. We conducted a systematic review of all studies meeting our criteria. Of the 14 studies that met the inclusion criteria, 8 were hypobaric hypoxia studies. Six studies reported data at rest at altitudes from 3,650 to 5,245 m. Two were simulations reporting exercise data at equivalent altitudes of 2,750-5,000 m. Nine studies used normobaric hypoxia corresponding to altitudes between 2,500 and 6,400 m. One reported only rest data, two reported rest and exercise data, and the others reported only exercise data. Sildenafil significantly reduced PaP at rest and exercise in hypobaric or normobaric hypoxia. There were no significant differences between arterial oxygen saturation (SpO) with sildenafil in hypobaric or normobaric hypoxia at rest or exercise. There were no significant differences in heart rate or mean arterial pressure (MAP) at rest or exercise and cardiac output during exercise in hypobaric or normobaric hypoxia. Sildenafil significantly reduces PaP at rest and exercise in normobaric or hypobaric hypoxia. Sildenafil has no significant effects on SpO, heart rate, cardiac output (during exercise), or MAP at rest or exercise in hypobaric or normobaric hypoxia.
Topics: Humans; Sildenafil Citrate; Altitude; Altitude Sickness; Hypoxia; Hypertension, Pulmonary
PubMed: 37751174
DOI: 10.1089/ham.2022.0043