Improvements in the methylmercury extraction from human hair by headspace solid-phase microextraction followed by gas-chromatography cold-vapour atomic fluorescence spectrometry

Improvements in the methylmercury extraction from human hair by solid-phase microextraction followed by gas chromatography coupled to cold-vapour atomic fluorescence spectrometry (GC-CVAFS) have been carried out. They consisted in the optimisation of the digestion step prior to the aqueous-phase ethylation and in the GC-CVAFS interface set-up. The main digestion parameters such as acid type, concentration, temperature and time have been optimised for hair sample analysis, thereby avoiding methylmercury degradation. Moreover, the stability of the digested samples was evaluated to improve the sample throughput

Elective Open Suprarenal Aneurysm Repair in England from 2000 to 2010 an Observational Study of Hospital Episode Statistics

Background: Open surgery is widely used as a benchmark for the results of fenestrated endovascular repair of complex abdominal aortic aneurysms (AAA). However, the existing evidence stems from single-centre experiences, and may not be reproducible in wider practice. National outcomes provide valuable information regarding the safety of suprarenal aneurysm repair. Methods: Demographic and clinical data were extracted from English Hospital Episodes Statistics for patients undergoing elective suprarenal aneurysm repair from 1 April 2000 to 31 March 2010. Thirty-day mortality and five-year survival were analysed by logistic regression and Cox proportional hazards modeling. Results: 793 patients underwent surgery with 14% overall 30-day mortality, which did not improve over the study period. Independent predictors of 30-day mortality included age, renal disease and previous myocardial infarction. 5-year survival was independently reduced by age, renal disease, liver disease, chronic pulmonary disease, and known metastatic solid tumour. There was significant regional variation in both 30-day mortality and 5-year survival after risk-adjustment. Regional differences in outcome were eliminated in a sensitivity analysis for perioperative outcome, conducted by restricting analysis to survivors of the first 30 days after surgery. Conclusions: Elective suprarenal aneurysm repair was associated with considerable mortality and significant regional variation across England. These data provide a benchmark to assess the efficacy of complex endovascular repair of supra-renal aneurysms, though cautious interpretation is required due to the lack of information regarding aneurysm morphology. More detailed study is required, ideally through the mandatory submission of data to a national registry of suprarenal aneurysm repair

DNA damage precedes apoptosis during the regression of the interdigital tissue in vertebrate embryos

DNA damage independent of caspase activation accompanies programmed cell death in different vertebrate embryonic organs. We analyzed the significance of DNA damage during the regression of the interdigital tissue, which sculpts the digits in the embryonic limb. Interdigit remodeling involves oxidative stress, massive apoptosis and cell senescence. Phosphorylation of H2AX mediated by ATM precedes caspase dependent apoptosis and cell senescence during interdigit regression. The association of ?H2AX with other downstream DNA repair factors, including MDC1, Rad50 and 53BP1 suggests a defensive response of cells against DNA damage. The relative distribution of cells ?H2AX-only positive, TUNEL-only positive, and cells double positive for both markers is consistent with a sequence of degenerative events starting by damage of the DNA. In support of this interpretation, the relative number of ?H2AX-only cells increases after caspase inhibition while the relative number of TUNELonly cells increases after inhibition of ATM. Furthermore, cultured interdigits survived and maintained intense chondrogenic potential, even at advanced stages of degeneration, discarding a previous commitment to die. Our findings support a new biological paradigm considering embryonic cell death secondary to genotoxic stimuli, challenging the idea that considers physiological cell death a cell suicide regulated by an internal death clock that pre-programmes degeneration

The association of personal and neighborhood socioeconomic indicators with subclinical cardiovascular disease in an elderly cohort. The cardiovascular health study.

There has been recent interest in determining whether neighborhood characteristics are related to the cardiovascular health of residents. However, there are no data regarding the relationship between neighborhood socioeconomic status (SES) and prevalence of subclinical cardiovascular disease (CVD) in the elderly. We related personal SES (education, income, and occupation type) and neighborhood socioeconomic characteristics (a block-group score summing six variables reflecting neighborhood income and wealth, education, and occupation) to the prevalence of subclinical CVD (asymptomatic peripheral vascular disease or carotid atherosclerosis, electrocardiogram or echocardiogram abnormalities, and/or positive responses to Rose Questionnaire claudication or angina pectoris) among 3545 persons aged 65 and over, without prevalent CVD, in the Cardiovascular Health Study. Sixty percent of participants had at least one indicator of subclinical disease. Compared to those without, those with subclinical disease had significantly lower education, income, and neighborhood scores and were more likely to have blue-collar jobs. After adjustment for age, gender, and race, those in the lowest SES groups had increased prevalence of subclinical disease compared with those in the highest SES groups (OR = 1.50; 95% CI 1.21, 1.86 for income; OR = 1.41; 95% CI 1.18, 1.69 for education; OR = 1.39; 95% CI 1.16, 1.67 for block-group score). Those reporting a blue-collar lifetime occupation had greater prevalence of subclinical disease relative to those reporting a white-collar occupation (OR = 1.29; 95% CI 1.02-1.59). After adjustment for behavioral and biomedical risk factors, all of these associations were reduced. Neighborhood score tended to remain inversely associated with subclinical disease after adjustment for personal socioeconomic indicators but associations were not statistically significant. Personal income and blue-collar occupation remained significantly associated with subclinical disease after simultaneous adjustment for neighborhood score and education. Personal and neighborhood socioeconomic indicators were associated with subclinical disease prevalence in this elderly cohort. These relationships were reduced after controlling for traditional CVD risk factors.http://deepblue.lib.umich.edu/bitstream/2027.42/78989/1/NordstromDiezRoux2004_SocSciMed.pd

Accurate Real-Time PCR Strategy for Monitoring Bloodstream Parasitic Loads in Chagas Disease Patients

Infection with the parasite Trypanosoma cruzi (T. cruzi), causing American trypanosomiasis or Chagas disease, remains a major public health concern in 21 endemic countries of America, with an estimated prevalence of 8 million infected people. Chagas disease shows a variable clinical course, ranging from asymptomatic to chronic stages with low parasitaemias, whose severest form is heart disease. Diagnosis at the asymptomatic and chronic stages is based on serological detection of anti-T. cruzi antibodies, because conventional parasitological methods lack sensitivity. Current chemotherapies are more effective in recent infections than in the chronic adult population. The criterion of cure relies on serological conversion to negative, which may occur only years after treatment, requiring long-term follow-up. In this context, we aimed to develop a real-time PCR assay targeted to repetitive sequences of T. cruzi for sensitive quantitation of parasitic load in peripheral blood of infected patients. It was applied to monitor treatment response of infected children, allowing rapid evaluation of drug efficacy as well as detection of treatment failure. It was also used for early diagnosis of chagasic reactivation in end-stage heart disease patients who received immunosuppressive drugs after cardiac transplantation. This laboratory strategy may constitute a novel parasitological tool for prompt and sensitive evaluation of anti-parasitic treatment of Chagas disease

Absorbing and transferring risk: assessing the impact of a statewide high-risk-pregnancy telemedical program on VLBW maternal transports

BACKGROUND: Prior research has shown that resources have an impact on birth outcomes. In this paper we ask how combinations of telemedical and hospital-level resources impact transports of mothers expecting very low birth weight (VLBW) babies in Arkansas. METHODS: Using de-identified birth certificate data from the Arkansas Department of Health, data were gathered on transports of women carrying VLBW babies for two six-month periods: a period just before the start of ANGELS (12/02-05/03), a telemedical outreach program for high-risk pregnancies, and a period after the program had been running for six months (12/03-05/04). For each maternal transport, the following information was recorded: maternal race-ethnicity, maternal age, and the birth weight of the infant. Logistic regression was used to assess the relationship between the predictors (telemedicine, hospital level, maternal characteristics) and the probability of a transport. RESULTS: Having a telemedical site available increases the probability of a mother carrying a VLBW baby being transported to a level III facility either before or during birth. Having at least a level II nursery also increases the chance of a maternal transport. Where both level II nurseries and telemedical access are available, the odds of VLBW maternal transports are only modestly increased in comparison to the case where neither is present. At the individual level, Hispanic mothers were less likely to be transported than other mothers, and teenaged mothers were more likely to be transported than those 18 and over. A mother's being Black or being over 35 did not have an impact on the odds of being transported to a level III facility. CONCLUSION: Combinations of resources have an impact on physician decisions regarding VLBW transports and are interpretable in terms of the capacity to diagnose and absorb risk. We suggest a collegial review of transport patterns and birth outcomes from areas with different levels of resources as a vehicle for moving the entire system of care forward over time. With such an evidence-based review in place, the collegial relations among level III specialists and obstetricians from around the state can, over time, develop workable protocols for when and how level III facilities should be involved

Engineering and Characterization of an Enhanced Fluorescent Protein Voltage Sensor

BACKGROUND: Fluorescent proteins have been used to generate a variety of biosensors to optically monitor biological phenomena in living cells. Among this class of genetically encoded biosensors, reporters for membrane potential have been a particular challenge. The use of presently known voltage sensor proteins is limited by incorrect subcellular localization and small or absent voltage responses in mammalian cells. RESULTS: Here we report on a fluorescent protein voltage sensor with superior targeting to the mammalian plasma membrane and high responsiveness to membrane potential signaling in excitable cells. CONCLUSIONS AND SIGNIFICANCE: This biosensor, which we termed VSFP2.1, is likely to lead to new methods of monitoring electrically active cells with cell type specificity, non-invasively and in large numbers, simultaneously

UHRF genes regulate programmed interdigital tissue regression and chondrogenesis in the embryonic limb

The primordium of the limb contains a number of progenitors far superior to those necessary to form the skeletal components of this appendage. During the course of development, precursors that do not follow the skeletogenic program are removed by cell senescence and apoptosis. The formation of the digits provides the most representative example of embryonic remodeling via cell degeneration. In the hand/foot regions of the embryonic vertebrate limb (autopod), the interdigital tissue and the zones of interphalangeal joint formation undergo massive degeneration that accounts for jointed and free digit morphology. Developmental senescence and caspase-dependent apoptosis are considered responsible for these remodeling processes. Our study uncovers a new upstream level of regulation of remodeling by the epigenetic regulators Uhrf1 and Uhrf2 genes. These genes are spatially and temporally expressed in the pre-apoptotic regions. UHRF1 and UHRF2 showed a nuclear localization associated with foci of methylated cytosine. Interestingly, nuclear labeling increased in cells progressing through the stages of degeneration prior to TUNEL positivity. Functional analysis in cultured limb skeletal progenitors via the overexpression of either UHRF1 or UHRF2 inhibited chondrogenesis and induced cell senescence and apoptosis accompanied with changes in global and regional DNA methylation. Uhrfs modulated canonical cell differentiation factors, such as Sox9 and Scleraxis, promoted apoptosis via up-regulation of Bak1, and induced cell senescence, by arresting progenitors at the S phase and upregulating the expression of p21. Expression of Uhrf genes in vivo was positively modulated by FGF signaling. In the micromass culture assay Uhrf1 was down-regulated as the progenitors lost stemness and differentiated into cartilage. Together, our findings emphasize the importance of tuning the balance between cell differentiation and cell stemness as a central step in the initiation of the so-called ?embryonic programmed cell death? and suggest that the structural organization of the chromatin, via epigenetic modifications, may be a precocious and critical factor in these regulatory events.Funding: We thank Montse Fernandez Calderon, Susana Dawalibi, and Sonia Perez Mantecon, for excellent technical assistance. This work was supported by a Grant (BFU2017-84046-P) from the Spanish Science and Innovation Ministry to J.A.M