336 research outputs found

    Evaluation of a novel assay for detection of the fetal marker RASSF1A: facilitating improved diagnostic reliability of noninvasive prenatal diagnosis

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    BackgroundAnalysis of cell free fetal (cff) DNA in maternal plasma is used routinely for non invasive prenatal diagnosis (NIPD) of fetal sex determination, fetal rhesus D status and some single gene disorders. True positive results rely on detection of the fetal target being analysed. No amplification of the target may be interpreted either as a true negative result or a false negative result due to the absence or very low levels of cffDNA. The hypermethylated RASSF1A promoter has been reported as a universal fetal marker to confirm the presence of cffDNA. Using methylation-sensitive restriction enzymes hypomethylated maternal sequences are digested leaving hypermethylated fetal sequences detectable. Complete digestion of maternal sequences is required to eliminate false positive results.MethodscfDNA was extracted from maternal plasma (n = 90) and digested with methylation-sensitive and insensitive restriction enzymes. Analysis of RASSF1A, SRY and DYS14 was performed by real-time PCR.ResultsHypermethylated RASSF1A was amplified for 79 samples (88%) indicating the presence of cffDNA. SRY real time PCR results and fetal sex at delivery were 100% accurate. Eleven samples (12%) had no detectable hypermethylated RASSF1A and 10 of these (91%) had gestational ages less than 7 weeks 2 days. Six of these samples were male at delivery, five had inconclusive results for SRY analysis and one sample had no amplifiable SRY.ConclusionUse of this assay for the detection of hypermethylated RASSF1A as a universal fetal marker has the potential to improve the diagnostic reliability of NIPD for fetal sex determination and single gene disorders

    Plasma transfusions prior to insertion of central lines for people with abnormal coagulation

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    Background: The insertion of central venous catheters (CVCs) may be associated with peri- and post-procedural bleeding. People who require a central line often have disorders of coagulation as a result of their underlying illness, co-morbidities or the effects of treatment. Clinical practice in some institutions is to mitigate the risk of bleeding in these patients by prophylactically transfusing fresh frozen plasma (FFP) in order to correct clotting factor deficiencies prior to central line insertion. However, FFP transfusion is not without risk, and it remains unclear whether this intervention is associated with reduced rates of bleeding or other clinically-meaningful outcomes. Objectives: To assess the effect of different prophylactic plasma transfusion regimens prior to central line insertion in people with abnormal coagulation. Search methods: We searched for randomised controlled trials (RCTs) in the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library 2016, Issue 3), PubMed (e-publications only), Ovid MEDLINE (from 1946), Ovid Embase (from 1974), the Transfusion Evidence Library (from 1950) and ongoing trial databases to 1 March 2016. Selection criteria: We included RCTs involving transfusions of plasma to prevent bleeding in people of any age with abnormal coagulation requiring insertion of a central venous catheter, published in English. Data collection and analysis: We used standard methodological procedures expected by Cochrane. Main results: We identified four trials eligible for inclusion, of which three are ongoing. We did not exclude any studies because they were not published in English. The included study randomised 81 adults in intensive care whose INR (International Normalised Ratio) was greater than or equal to 1.5 to no FFP or to a single dose of 12 mL/kg FFP prior to undergoing central venous catheterisation (58 participants) or other invasive procedure (23 participants). It is the subgroup of 58 adults undergoing CVC insertion that were included in this review, the study authors provided unpublished data for this review's outcomes. The quality of the evidence was low or very low across different outcomes according to the GRADE methodology. The included study was at high risk of bias due to lack of blinding of participants and personnel and imbalance in the number of participants who had liver disease between study arms. There was insufficient evidence to determine a difference in major procedure-related bleeding within 24 hours (one RCT; 58 participants; no events in either study arm, very low-quality evidence). We are very uncertain whether FFP reduces minor procedure-related bleeding within 24 hours of the study (one RCT; 58 participants, RR 0.67, 95% CI 0.12 to 3.70, very low-quality evidence). No studies were found that looked at: all-cause mortality; the proportion of participants receiving plasma or red cell transfusions; serious adverse reactions (transfusion or line-related complications); number of days in hospital; change in INR; or quality of life. The three ongoing studies are still recruiting participants (expected recruitment: up to 355 participants in total). and are due to be completed by February 2018. Authors' conclusions: There is only very limited evidence from one RCT to inform the decision whether or not to administer prophylactic plasma prior to central venous catheterisation for people with abnormal coagulation. It is not possible from the current RCT evidence to recommend whether or not prophylactic plasma transfusion is beneficial or harmful in this situation. The three ongoing RCTs will not be able to answer this review’s questions, because they are small studies and do not address all of the comparisons included in this review (355 participants in total). To detect an increase in the proportion of participants who had major bleeding from 1 in 100 to 2 in 100 would require a study containing at least 4634 participants (80% power, 5% significance)

    Left atrial function in heart failure with preserved ejection fraction:a systematic review and meta-analysis

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    Aims Left atrial (LA) mechanical function may play a significant role in the development and progression of heart failure with preserved ejection fraction (HFpEF). We performed a systematic review and meta-analysis to evaluate association of impaired LA function with outcomes in HFpEF. Methods and results Multiple databases were searched for original studies measuring different phases of LA function in HFpEF patients. Comparative LA function between HFpEF patients and healthy controls was assessed by pooling weighted mean differences (WMD). Adjusted hazard ratios (HRs) with 95% confidence intervals were pooled to evaluate the prognostic utility of LA function. Twenty-two studies (2 trials, 20 observational) comprising 1974 HFpEF patients and 751 healthy controls were included. HFpEF patients had decreased LA reservoir [WMD = -12.21% (-15.47, -8.95); P <0.001], LA conduit [WMD = -5.68% (-8.56, -2.79); P <0.001], and pump [WMD = -11.07% (-14.81, -7.34); P <0.001] emptying fractions compared with controls. LA reservoir [WMD = -13.38% (-16.07, -10.68); P <0.001], conduit [WMD = -4.09% (-6.77, -1.42); P = 0.003], and pump [WMD = -3.53% (-4.47, -2.59); P <0.001] strains were also significantly lower in HFpEF patients. Decreased LA reservoir strain [HR 1.24 (1.02, 1.50); P = 0.03] was significantly associated with risk of composite all-cause mortality or heart failure hospitalization. Conclusions Impaired LA function appears to have diagnostic and prognostic value in HFpEF, but whether indices of LA function truly refine discrimination for diagnosis or prognosis remains to be fully determined. Larger studies are needed to better evaluate associations between LA function and clinical outcomes and the role of LA function as a target for novel HFpEF therapies

    Was an increase in cocaine use among injecting drug users in New South Wales, Australia, accompanied by an increase in violent crime?

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    BACKGROUND: A sharp reduction in heroin supply in Australia in 2001 was followed by a large but transient increase in cocaine use among injecting drug users (IDU) in Sydney. This paper assesses whether the increase in cocaine use among IDU was accompanied by increased rates of violent crime as occurred in the United States in the 1980s. Specifically, the paper aims to examine the impact of increased cocaine use among Sydney IDU upon police incidents of robbery with a weapon, assault and homicide. METHODS: Data on cocaine use among IDU was obtained from the Illicit Drug Reporting System (IDRS). Monthly NSW Police incident data on arrests for cocaine possession/use, robbery offences, homicides, and assaults, were obtained from the Bureau of Crime Statistics and Research. Time series analysis was conducted on the police data series where possible. Semi-structured interviews were conducted with representatives from law enforcement and health agencies about the impacts of cocaine use on crime and policing. RESULTS: There was a significant increase in cocaine use and cocaine possession offences in the months immediately following the reduction in heroin supply. There was also a significant increase in incidents of robbery where weapons were involved. There were no increases in offences involving firearms, homicides or reported assaults. CONCLUSION: The increased use of cocaine among injecting drug users following the heroin shortage led to increases in violent crime. Other States and territories that also experienced a heroin shortage but did not show any increases in cocaine use did not report any increase in violent crimes. The violent crimes committed did not involve guns, most likely because of its stringent gun laws, in contrast to the experience of American cities that have experienced high rates of cocaine use and violent crime

    Unfamiliar Territory: Emerging Themes for Ecological Drought Research and Management

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    Novel forms of drought are emerging globally, due to climate change, shifting teleconnection patterns, expanding human water use, and a history of human influence on the environment that increases the probability of transformational ecological impacts. These costly ecological impacts cascade to human communities, and understanding this changing drought landscape is one of today\u27s grand challenges. By using a modified horizon-scanning approach that integrated scientists, managers, and decision-makers, we identified the emerging issues in ecological drought that represent key challenges to timely and effective responses. Here we review the themes that most urgently need attention, including novel drought conditions, the potential for transformational drought impacts, and the need for anticipatory drought management. This horizon scan and review provides a roadmap to facilitate the research and management innovations that will support forward-looking, co-developed approaches to reduce the risk of drought to our socio-ecological systems during the 21st century. We used a modified horizon-scanning approach that brought together scientists, managers, and decision-makers to identify the emerging issues around the ecological impacts from drought that represent key challenges to effective response. We found three broad themes within ecological drought that need attention, including novel drought conditions, transformational drought impacts, and anticipatory drought management. This horizon scan and integrated review provides a roadmap to inspire the needed research and management innovations to reduce the risk of 21st century droughts

    The "lessons" of the Australian "heroin shortage"

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    Heroin use causes considerable harm to individual users including dependence, fatal and nonfatal overdose, mental health problems, and blood borne virus transmission. It also adversely affects the community through drug dealing, property crime and reduced public amenity. During the mid to late 1990s in Australia the prevalence of heroin use increased as reflected in steeply rising overdose deaths. In January 2001, there were reports of an unpredicted and unprecedented reduction in heroin supply with an abrupt onset in all Australian jurisdictions. The shortage was most marked in New South Wales, the State with the largest heroin market, which saw increases in price, dramatic decreases in purity at the street level, and reductions in the ease with which injecting drug users reported being able to obtain the drug. The abrupt onset of the shortage and a subsequent dramatic reduction in overdose deaths prompted national debate about the causes of the shortage and later international debate about the policy significance of what has come to be called the "Australian heroin shortage". In this paper we summarise insights from four years' research into the causes, consequences and policy implications of the "heroin shortage"

    A method for comparing multiple imputation techniques: A case study on the U.S. national COVID cohort collaborative.

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    Healthcare datasets obtained from Electronic Health Records have proven to be extremely useful for assessing associations between patients’ predictors and outcomes of interest. However, these datasets often suffer from missing values in a high proportion of cases, whose removal may introduce severe bias. Several multiple imputation algorithms have been proposed to attempt to recover the missing information under an assumed missingness mechanism. Each algorithm presents strengths and weaknesses, and there is currently no consensus on which multiple imputation algorithm works best in a given scenario. Furthermore, the selection of each algorithm’s pa- rameters and data-related modeling choices are also both crucial and challenging
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