The burden of heat-related mortality attributable to recent human-induced climate change

Climate change affects human health; however, there have been no large-scale, systematic efforts to quantify the heat-related human health impacts that have already occurred due to climate change. Here, we use empirical data from 732 locations in 43 countries to estimate the mortality burdens associated with the additional heat exposure that has resulted from recent human-induced warming, during the period 1991-2018. Across all study countries, we find that 37.0% (range 20.5-76.3%) of warm-season heat-related deaths can be attributed to anthropogenic climate change and that increased mortality is evident on every continent. Burdens varied geographically but were of the order of dozens to hundreds of deaths per year in many locations. Our findings support the urgent need for more ambitious mitigation and adaptation strategies to minimize the public health impacts of climate change.

What measure of temperature is the best predictor of mortality?

Hot and cold temperatures significantly increase mortality rates around the world, but which measure of temperature is the best predictor of mortality is not known. We used mortality data from 107 US cities for the years 1987-2000 and examined the association between temperature and mortality using Poisson regression and modelled a non-linear temperature effect and a non-linear lag structure. We examined mean, minimum and maximum temperature with and without humidity, and apparent temperature and the Humidex. The best measure was defined as that with the minimum cross-validated residual. We found large differences in the best temperature measure between age groups, seasons and cities, and there was no one temperature measure that was superior to the others. The strong correlation between different measures of temperature means that, on average, they have the same predictive ability. The best temperature measure for new studies can be chosen based on practical concerns, such as choosing the measure with the least amount of missing data.

Acute-care nurses' attitudes towards older patients: a literature review

With increases in life expectancy and increasing numbers of older patients utilising the acute setting, attitudes of registered nurses caring for older people may affect the quality of care provided. This paper reviews recent research on positive and negative attitudes of acute-care nurses towards older people. Many negative attitudes reflect ageist streotypes and knowledge deficits that significantly influence registered nurses' practice and older patients' quality of care. In the acute setting, older patients experience reduced independence, limited decision-making opportunities, increased probability of developing complications, little consideration of their ageing-related needs, limited health education and social isolation. Available instruments to measure attitudes towards and knowledge about older people, although reliable and valid, are outdated, country-specific and do not include either a patient-focus or a caring perspective. This paper argues for the development and utilisation of a research instrument that includes both a patient focus and a caring dimension.

Noise and signal properties in PSF-based fully 3D PET image reconstruction: an experimental evaluation

The addition of accurate system modeling in PET image reconstruction results in images with distinct noise texture and characteristics. In particular, the incorporation of point spread functions (PSF) into the system model has been shown to visually reduce image noise, but the noise properties have not been thoroughly studied. This work offers a systematic evaluation of noise and signal properties in different combinations of reconstruction methods and parameters. We evaluate two fully 3D PET reconstruction algorithms: (1) OSEM with exact scanner line of response modeled (OSEM+LOR), (2) OSEM with line of response and a measured point spread function incorporated (OSEM+LOR+PSF), in combination with the effects of four post-reconstruction filtering parameters and 1-10 iterations, representing a range of clinically acceptable settings. We used a modified NEMA image quality (IQ) phantom, which was filled with 68Ge and consisted of six hot spheres of different sizes with a target/background ratio of 4:1. The phantom was scanned 50 times in 3D mode on a clinical system to provide independent noise realizations. Data were reconstructed with OSEM+LOR and OSEM+LOR+PSF using different reconstruction parameters, and our implementations of the algorithms match the vendor's product algorithms. With access to multiple realizations, background noise characteristics were quantified with four metrics. Image roughness and the standard deviation image measured the pixel-to-pixel variation; background variability and ensemble noise quantified the region-to-region variation. Image roughness is the image noise perceived when viewing an individual image. At matched iterations, the addition of PSF leads to images with less noise defined as image roughness (reduced by 35% for unfiltered data) and as the standard deviation image, while it has no effect on background variability or ensemble noise. In terms of signal to noise performance, PSF-based reconstruction has a 7% improvement in contrast recovery at matched ensemble noise levels and 20% improvement of quantitation SNR in unfiltered data. In addition, the relations between different metrics are studied. A linear correlation is observed between background variability and ensemble noise for all different combinations of reconstruction methods and parameters, suggesting that background variability is a reasonable surrogate for ensemble noise when multiple realizations of scans are not available.

The impact of fluctuations in intensity patterns on the number of monitor units and the quality and accuracy of intensity modulated radiotherapy

The purpose of this work is to examine the potential impact of the frequency and amplitude of fluctuations ("complexity") in intensity distributions on intensity-modulated radiotherapy (IMRT) dose distributions. The intensity-modulated beams are efficiently delivered using a multileaf collimator (MLC). Radiation may be delivered through a continuous (dynamic mode) or discrete (step-and-shoot) sequence of windows formed by the leaves. Algorithms and software that convert optimized intensity distributions into leaf trajectories apply approximate empirical corrections to account for the various effects associated with MLC characteristics, such as the rounded leaf tips, tongue-and-groove leaf design, leaf transmission, leaf scatter, and collimator scatter upstream from the MLC. Typically, the difference between inter- and intraleaf transmissions is ignored. In this paper, using a schematic example of IMRT for head and neck carcinomas, we demonstrate that complex anatomy and severe optimization constraints produce complex intensity patterns. Using idealized intensity patterns we also demonstrate that, for complex intensity patterns, the average window width tends to be smaller and, for the same dose received by the tumor, the number of MUs is larger. We found that as the complexity increases, so does the contribution of radiation transmitted through and scattered from the leaves ("indirect radiation") to the total delivered dose. As a consequence, the lowest deliverable intensity in complex intensity patterns may be significantly greater than that required to provide adequate protection for some normal tissues. Furthermore, since corrections for leaf transmission and scatter effects are approximate and the difference between inter- and intraleaf transmission is ignored, the accuracy of the delivered dose may be affected. Using the results of a simple experiment and a typical intensity-modulated beam for a head and neck case as examples, we show the effect of window width and complexity on the accuracy and deliverability of intensity patterns. Some possible strategies for improving the accuracy and for relaxing the lower limit on deliverable intensity are discussed.

Lifetime exposure to environmental lead and children's intelligence at 11-13 years: the Port Pirie cohort study

OBJECTIVE

To examine the association between environmental exposure to lead and children's intelligence at age 11-13 years, and to assess the implications of exposure in the first seven years of life for later childhood development.

DESIGN

Prospective cohort study.

SUBJECTS

375 children born in or around the lead smelting town of Port Pirie, Australia, between 1979 and 1982.

MAIN OUTCOME MEASURE

Children's intelligence quotient (IQ) measured at 11-13 years of age.

RESULTS

IQ was inversely associated with both antenatal and postnatal blood lead concentrations. Verbal, performance, and full scale IQ were inversely related to blood lead concentration with no apparent threshold. Multivariate analyses indicated that after adjustment for a wide range of confounders, the postnatal blood lead concentrations (particularly within the age range 15 months to 7 years) exhibited inverse associations with IQ. Strong associations with IQ were observed for lifetime average blood lead concentrations at various ages. The expected mean full scale IQ declined by 3.0 points (95% confidence interval 0.07 to 5.93) for an increase in lifetime average blood lead concentration from 0.48 to 0.96 mumol/l (10 to 20 micrograms/dl).

CONCLUSION

Exposure to environmental lead during the first seven years of life is associated with cognitive deficits that seem to persist into later childhood.

Determinants of smoking and cessation during and after pregnancy

Smoking during pregnancy is harmful to both the foetus and the woman herself. However, in spite of educational efforts, a substantial proportion of pregnant women continue to smoke and many women who do stop smoking during pregnancy resume smoking following childbirth. To foster successful maternal smoking cessation, public health professionals need to focus on the major determinants of smoking and cessation during and after pregnancy, and then to address these with their intervention efforts. It is important to review contemporary epidemiological evidence on this significant public health issue. We have identified nine cohort studies, published in international peer-reviewed journals, that have examined determinants of smoking and cessation in pregnant women. The results indicate that the determinants of pregnant smoking and cessation include maternal age, dose and duration of smoking, partner's smoking habit, socioeconomic status, level of education, age to start smoking, level of addiction, parity and passive smoking. However, many other psychosocial factors, which may affect smoking status among pregnant women, remain to be identified. Evidence reviewed here suggests that a more focused, integrated approach and a more comprehensive assessment of major determinants of smoking and cessation during pregnancy will be required as part of any future intervention effort.

Declining blood lead levels and changes in cognitive function during childhood: the Port Pirie Cohort Study

CONTEXT

Many studies have found a significant inverse association between early exposure to environmental lead and cognitive function in childhood. Whether these effects are reversible when exposure is reduced is not clear.

OBJECTIVE

To assess the reversibility of the apparent effects of lead on cognitive abilities in early childhood by testing whether declines in blood lead concentrations beyond the age of 2 years are associated with improvements in cognition.

SETTING

Urban and rural communities surrounding a large lead smelter in Port Pirie, South Australia.

PARTICIPANTS

A total of 375 children followed up from birth to the age of 11 to 13 years.

DESIGN

Long-term prospective cohort study.

MAIN OUTCOME MEASURES

The Bayley Mental Development Index at age 2 years, the McCarthy General Cognitive Index at age 4 years, and IQs from the Wechsler Intelligence Scale (revised version) at ages 7 and 11 to 13 years.

RESULTS

Mean blood lead concentrations in the children decreased from 1.02 pmol/L (21 .2 microg/dL) at age 2 years to 0.38 micromol/L (7.9 microg/dL) at age 1 1 to 13 years, but cognitive scores in children whose blood lead concentration declined most were generally not improved relative to the scores of children whose blood lead levels declined least. Changes in IQ and declines in blood lead levels that occurred between the ages of 7 and 11 to 13 years (r= 0.12, P= .09) suggested slightly better cognition among children whose blood lead levels declined most.

CONCLUSION

The cognitive deficits associated with exposure to environmental lead in early childhood appear to be only partially reversed by a subsequent decline in blood lead level.

Ozone modifies associations between temperature and cardiovascular mortality: analysis of the NMMAPS data

OBJECTIVES

Both ambient ozone and temperature are associated with human health. However, few data are available on whether ozone modifies temperature effects. This study aims to explore whether ozone modified associations between maximum temperature and cardiovascular mortality in the USA.

METHODS

The authors obtained data from the US National Morbidity, Mortality, and Air Pollution Study (NMMAPS) website. They used two time-series Poisson regression models (a response surface model and a stratification model) to examine whether ozone modified associations between maximum temperature and cardiovascular mortality (CVM) in 95 large US communities during 1987-2000 in summer (June to September). Bayesian meta-analysis was used to pool estimates in each community.

RESULTS

The response surface model was used to examine the joint effects of temperature and ozone on CVM in summer. Results indicate that ozone positively modified the temperature-CVM associations across the different regions. The stratification model quantified the temperature-CVM associations across different levels of ozone. Results show that in general the higher the ozone concentration, the stronger the temperature-CVM associations across the communities. A 10 degrees C increase in temperature on the same day was associated with an increase in CVM by 1.17% and 8.31% for the lowest and highest level of ozone concentrations in all communities, respectively.

CONCLUSION

Ozone modified temperature effects in different regions in the USA. It is important to evaluate the modifying role of ozone when estimating temperature-related health impacts and to further investigate the reasons behind the regional variability and mechanism for the interaction between temperature and ozone.

Trousseau's syndrome. Devastating coagulopathy in the absence of heparin

Two patients with Trousseau's syndrome experienced frequently recurring concomitant arterial and venous thrombotic events that resulted in sequential amputation and loss of the lower extremities. Serial examination of the blood in the patients demonstrated that these devastating thrombotic events were preceded by severe disseminated intravascular coagulopathy that occurred within an interval of a few hours. Warfarin therapy was without effect in preventing the occurrence of these events. Both patients demonstrated the absolute need for intravenous heparin, which effectively prevented the thrombotic events; when it was discontinued, the immediate consequences were disastrous and resulted in death. Techniques for long-term outpatient heparin therapy are discussed.

Intra- and inter-observer variability and reliability of prostate volume measurement via two-dimensional and three-dimensional ultrasound imaging

We describe the results of a study to evaluate the intra- and inter-observer variability and reliability of prostate volume measurements made from transrectal ultrasound (TRUS) images, using either the (optimal) height-width-length (HWL) method (V = pi/6 HWL) with two-dimensional (2D) TRUS images (obtained as cross-sections of three-dimensional [3D] TRUS images) or manual planimetry of 3D TRUS images (the 3D US method). In this study, eight observers measured 15 prostate images, twice via each method, and an analysis of variance (ANOVA) was performed. This analysis shows that, with the 3D US method, intra-observer prostate volume estimates have 5.1% variability and 99% reliability, and inter-observer estimates have 11.4% variability and 96% reliability. With the HWL method, intra-observer estimates have 15.5% variability and 93% reliability, and inter-observer estimates have 21.9% variability and 87% reliability. Thus, in vivo prostate volume estimates from manual planimetry of 3D TRUS images have much lower variability and higher reliability than HWL estimates from 2D TRUS images.

Time-dependent entropy estimation of EEG rhythm changes following brain ischemia

Our approach is motivated by the need to generate a rigorous measure of the degree of disorder (or complexity) of the EEG signal in brain injury. Entropy is a method to quantify the order/disorder of a time series. It is the first time that a time-dependent entropy (TDE) is used in the quantification of brain injury level. The TDE was sensitive enough to monitor the significant changes in the subject's brain rhythms during recovery from global ischemic brain injury. Among the different entropy measures, we used Tsallis entropy. This entropy is parametrized and is able to match with the particular properties of EEG, like long-range rhythms, spikes, and bursts. The method was tested in a signal composed of segments of synthetic signals (Gaussian and uniform distributions) and segments of real signals. The real signal segments were extracted from normal EEG, EEG recordings from early recovery, and normal EEG corrupted by simulated spikes and bursts. Adult Wistar rats were subjected to asphyxia-cardiac arrest for 3 and 5 min. The TDE detected the pattern of ischemia-induced EEG alterations and was able to discriminate the different injury levels. Two parameters seem to be good descriptors of the recovery process; the mean entropy and the variance of the estimate followed opposite trends, with the mean entropy decreasing and its variance increasing with injury.

Family self-medication and antibiotics abuse for children and juveniles in a Chinese city

To identify the determinants of self-medication and antibiotics abuse by parents treating their children aged between 2 and 18 over the previous year, an investigation was conducted in Hefei City, China in April, 1995. A total of 1596 students from a kindergarten, a primary school and a high school were included in the study, and 1459 completed questionnaires were collected (the response rate: 91.4%). The results showed the rate of parental self-medication for their children in the sample was 59.4%. It increased with children's age; about 51% of children had received parental self-medication on six or more occasions during the 1-year period and 32.8% on four to five occasions; there were associations between parental self-prescribers and sources of medicine and severity of disease. The rate of antibiotics abuse was 35.7%. Logistic regression analysis showed that there were significant associations between self-medication and payment of the mother's medical fees by employers, severity of diseases as well as the mother's educational level.

A three-dimensional ultrasound prostate imaging system

We have developed a three-dimensional (3D) transrectal ultrasound imaging system, based on using a motorized 5 MHz transducer assembly, rotated under microcomputer control, to collect a series of 100 two-dimensional (2D) images, digitized by a video frame-grabber. These are then reconstructed into a 3D image on a computer workstation, permitting the prostate anatomy to be visualized in three dimensions, and distance and volume measurements to be performed. The accuracy of the distance measurements was assessed with a string test phantom, and that of the volume measurements with balloons of known sizes. Also, the resolution degradation engendered by the reconstruction algorithm was assessed by comparing the full-width at half-maximum (FWHM) of string cross-sectional images in the 3D image to their 2D counterparts. The results show that distance and volume measurements are both accurate to about +/- 1%, and that the reconstruction algorithm increases the mean FWHM by 8 +/- 3% axially and 3 +/- 3% laterally.

Molecular characterization of the Entner-Doudoroff pathway in Escherichia coli: sequence analysis and localization of promoters for the edd-eda operon

The nucleotide sequence of the entire Escherichia coli edd-eda region that encodes the enzymes of the Entner-Doudoroff pathway was determined. The edd structural gene begins 236 bases downstream of zwf. The eda structural gene begins 34 bases downstream of edd. The edd reading frame is 1,809 bases long and encodes the 602-amino-acid, 64,446-Da protein 6-phosphogluconate dehydratase. The deduced primary amino acid sequences of the E. coli and Zymomonas mobilis dehydratase enzymes are highly conserved. The eda reading frame is 642 bases long and encodes the 213-amino-acid, 22,283-Da protein 2-keto-3-deoxy-6-phosphogluconate aldolase. This enzyme had been previously purified and sequenced by others on the basis of its related enzyme activity, 2-keto-4-hydroxyglutarate aldolase. The data presented here provide proof that the two enzymes are identical. The primary amino acid sequences of the E. coli, Z. mobilis, and Pseudomonas putida aldolase enzymes are highly conserved. When E. coli is grown on gluconate, the edd and eda genes are cotranscribed. Four putative promoters within the edd-eda region were identified by transcript mapping and computer analysis. P1, located upstream of edd, appears to be the primary gluconate-responsive promoter of the edd-eda operon, responsible for induction of the Entner-Doudoroff pathway, as mediated by the gntR product. High basal expression of eda is explained by constitutive transcription from P2, P3, and/or P4 but not P1.

Interactions between environmental lead exposure and sociodemographic factors on cognitive development

A total of 375 children who lived in Port Pirie, South Australia, and surrounding towns were followed from birth to ages 11-13 y. Possible interactions between lifetime average blood lead concentration and sociodemographic factors (including gender, parents' occupational prestige [as a surrogate of socioeconomic status], quality of home environment, and maternal intelligence quotient) on children's intelligence quotients were examined. Although no statistically significant interaction between blood lead concentration and any of these covariates was found, the results suggested that-after adjustment for a wide range of covariates--children from socially disadvantaged backgrounds (adjusted regression coefficient = -9.6 intelligence quotient points per log unit of blood lead concentration; 95% confidence interval = -2.5, -17.7) were more sensitive to the effects of lead than those of a higher socioeconomic status (adjusted regression coefficient = -2.9; 95% confidence interval = 3.8, -9.6). In addition, girls (adjusted regression coefficient = -7.4; 95% confidence interval = -1.7, -13.1) were more sensitive to the effects of lead than boys (adjusted regression coefficient = -2.6; 95% confidence interval = 2.9, -8.0). These results were basically consistent with our findings observed at ages 2 y, 4 y, and 7 y.

Over-expression of lipocalin 2 promotes cell migration and invasion through activating ERK signaling to increase SLUG expression in prostate cancer

BACKGROUND

Metastasis is the primary cause of prostate cancer (PCa) lethality and poses a huge clinical obstacle. Lipocalin 2 (LCN2), a member of the lipocalin family, is aberrantly expressed in some human cancers and has been implicated in the progression of some tumors. However, the role of LCN2 in the metastatic capacity of prostate cancer (PCa) is poorly understood.

METHODS

LCN2 expression was examined by RT-qPCR and/or immunoblotting in human prostate tissue specimens and prostate cancer cell lines LNCaP, C4-2, 22RV1, PC3, DU-145, and PC3MM2. LCN2 protein level in human serum samples was determined by ELISA. Lentiviruses-mediated over-expression of LCN2 and knockdown of LCN2 was conducted to evaluate the role of LCN2 in cell migratory and invasive capacities of prostate cancer cells. Cell migration and invasion was examined by transwell chamber assay. Knockdown of SLUG by lentivirus was performed to investigate its role in LCN2-promoted cell migration and invasion in vitro (22RV1 cell line) and metastasis in vivo (tail vein metastasis assay in nude mice). Role of ERK signaling in LCN2-mediated up-regulation of SLUG was assayed by using ERK inhibitor U0126.

RESULTS

We confirmed that LCN2 levels were correlated positively with invasive prostate cancer in human tissue and serum samples, and were also consistently associated with the invasive capacity of prostate cancer cell lines. The over-expression of LCN2 in 22RV1 cells (not highly invasive) promoted the epithelial-mesenchymal transition (EMT), increasing cell motility and invasiveness, while the knockdown of LCN2 in PC3 cells (highly invasive) inhibited EMT, decreasing cell motility and invasiveness. Among the multiple EMT transcription factors, LCN2 specifically induces the expression of SLUG, which was shown here to be required for the LCN2-induced increase in the invasive capacity of prostate cancer cells both in vitro and in vivo. Mechanistically, LCN2 promoted SLUG expression via activating ERK signaling pathway.

CONCLUSION

LCN2 plays an important role in promoting cell migration and invasion of prostate cancer by inducing EMT through the ERK/SLUG axis. Therefore, targeted inhibition of LCN2 may represent a therapeutic strategy to prevent the metastasis of prostate cancer.

Cloning and molecular genetic characterization of the Escherichia coli gntR, gntK, and gntU genes of GntI, the main system for gluconate metabolism

Three genes involved in gluconate metabolism, gntR, gntK, and gntU, which code for a regulatory protein, a gluconate kinase, and a gluconate transporter, respectively, were cloned from Escherichia coli K-12 on the basis of their known locations on the genomic restriction map. The gene order is gntU, gntK, and gntR, which are immediately adjacent to asd at 77.0 min, and all three genes are transcribed in the counterclockwise direction. The gntR product is 331 amino acids long, with a helix-turn-helix motif typical of a regulatory protein. The gntK gene encodes a 175-amino-acid polypeptide that has an ATP-binding motif similar to those found in other sugar kinases. While GntK does not show significant sequence similarity to any known sugar kinases, it is 45% identical to a second putative gluconate kinase from E. coli,gntV. The 445-amino-acid sequence encoded by gntU has a secondary structure typical of membrane-spanning transport proteins and is 37% identical to the gntP product from Bacillus subtilis. Kinetic analysis of GntU indicates an apparent Km for gluconate of 212 microM, indicating that this is a low-affinity transporter. Studies demonstrate that the gntR gene is monocistronic, while the gntU and gntK genes, which are separated by only 3 bp, form an operon. Expression of gntR is essentially constitutive, while expression of gntKU is induced by gluconate and is subject to fourfold glucose catabolite repression. These results confirm that gntK and gntU, together with another gluconate transport gene, gntT, constitute the GntI system for gluconate utilization, under control of the gntR gene product, which is also responsible for induction of the edd and eda genes of the Entner-Doudoroff pathway.

Dynamic splitting of large intensity-modulated fields

The aims of this paper are to describe a method of splitting large intensity-modulated fields that cannot be delivered as a single field and to verify the accuracy of our method. Some multi-leaf collimators may be operated in the dynamic mode to deliver intensity-modulated radiation treatments (IMRT) using the 'sliding window' technique. In this technique each pair of leaves sweeps over the treatment field while the beam is on. However, there are limitations on the width of the field that can be treated due to the limited length of the leaves. For instance, the leaf length of the Varian MLC is 14.5 cm. Since each leaf pair must travel from the left boundary to the right boundary of the beam aperture, the maximum width of the field aperture that can be accommodated in one sweep of leaves is also limited to 14.5 cm, in fact to a slightly smaller value. It has been shown that IMRT is more efficient when used to plan and deliver the large and boost fields simultaneously. In such situations, the fields must be large enough to cover simultaneously the volumes of the gross tumour, microscopic disease and electively treated regions. Such field sizes are often larger than 14.5 cm wide. In this paper, we present a dynamic 'feathering' technique to split the large intensity-modulated fields into smaller fields. In this technique, the component beams overlap each other by a small amount, and the intensity in the overlap region gradually decreases for one field component and increases for the other. The sum of intensities remains the same as for the original field. This method eliminates the field matching problems associated with the conventional step 'break' for static fields. The splitting process is integrated into the IMRT treatment procedure and the entire planning process is automated. Comparison of dose distributions calculated and measured in a phantom showed good agreement. Such a method can be applied to the 'step and shoot' technique as well. IMRT fields of widths up to 25 cm can be delivered by splitting only once, which is adequate for most treatments.

Antioxidant properties of carvedilol and metoprolol in heart failure: a double-blind randomized controlled trial

Animal and human studies have shown that carvedilol has significant antioxidant properties compared with other beta-blockers. The objective of this study was to determine if these antioxidant effects are detectable in patients with heart failure and to compare carvedilol with the selective beta-blocker metoprolol. Twenty-four patients with chronic heart failure were randomly assigned to receive either carvedilol or metoprolol in a double-blind control trial for 12 weeks in a University teaching hospital clinic. Blood pressure, heart rate, exercise tolerance, left ventricular ejection fraction, plasma total antioxidant status, erythrocyte superoxide dismutase, and glutathione peroxidase activities were determined at baseline and every 4 weeks up to 12 weeks. The results showed that erythrocyte superoxide dismutase and glutathione peroxidase were significantly reduced in carvedilol treated patients after 12 weeks of therapy, whereas metoprolol had no significant effect, although the clinical improvement over the short-term was similar with both drugs. Thus carvedilol, in addition to improving symptoms in heart failure, also possesses significant antioxidant properties. Whether this additional action influences long-term outcome is at present unknown.

Preventing and mitigating health risks of climate change

Global environmental changes, driven by the consequences of human activities and population growth, are altering our planet in ways that pose current threats to human health, with the magnitude of these threats projected to increase over coming decades if additional, proactive actions are not taken. Global changes, unprecedented in their geospatial and temporal scales, include climate change, marine pollution, ozone layer depletion, soil degradation, and urbanization. Climate change is the best studied. The health risks of a changing climate will become increasingly urgent as climate change affects the quantity and quality of food and water, increases air pollution, alters the distribution of vectors/pathogens and disease transmission dynamics, and reduces eco-physical buffering against extreme weather and climate events. Health systems urgently need to be improved to effectively address these emerging challenges. This paper provides an overview of the health consequences of climate change, and discusses how health risks can be minimized and avoided via mitigation and adaptation pathways.

Periostin Mediates TGF-β-Induced Epithelial Mesenchymal Transition in Prostate Cancer Cells

BACKGROUND

In our previous study, we found that periostin was upregulated in prostate cancer, and its expression could be modulated by TGF-β. TGF-β could upregulate periostin expression in some cells, and both TGF-β and periostin could induce epithelial mesenchymal transition (EMT). We aimed to study the effect of periostin in the process of TGF-β-induced EMT in prostate cancer cells.

METHODS

We constructed a lentivirus vector containing the periostin gene and transduced it into PC3 and DU145 cells. After confirming periostin overexpression by PCR and Western blotting, we used an MTT assay to establish a growth curve to measure cell proliferation. Additionally, we performed transwell and wound healing assays to measure cell invasion and migration, respectively. Lastly, we measured the expression of EMT associated factors using Western blot analysis to test the effect of periostin on EMT in prostate cancer cells.

RESULTS

PCR and Western blot analyses confirmed that periostin was upregulated after infection with the periostin lentiviral vector. Periostin overexpression promoted increased cell proliferation, invasion, and migration as measured by MTT, transwell, and wound healing assays, respectively. Western blot analysis illustrated that periostin overexpression increased the expression of EMT associated factors, and periostin overexpression activated Akt and GSK-3β, which could be inhibited using a PI3K inhibitor. Additionally, TGF-β increased the levels of STAT3, Twist1 and periostin, while both STAT3 shRNA and Twist1 shRNA inhibited periostin expression. However, STAT3 shRNA also decreased Twist1 expression. Although reduction of STAT3, Twist1 or periostin levels with shRNA inhibited TGF-β-induced overexpression of EMT associated factors, periostin overexpression could reverse such inhibition by interfering with STAT3 and Twist1. Similarly, periostin overexpression also reversed inhibition of cell invasion induced by interference of STAT3 and Twist1.

CONCLUSION

Our findings indicate that periostin is an important mediator of TGF-β-induced EMT and suggest that periostin is a potential therapeutic target for suppressing the metastatic progression of prostate cancer.

Laboratory investigation of ecological factors influencing the environmental presence of Burkholderia pseudomallei

Factors like temperature, pH value, water content in soil, and ultraviolet rays that might have influence on the survival of environmental Burkholderia pseudomallei strains were evaluated. Data showed that the optimal temperature and pH value for B. pseudomallei were 24 C to 32 C and 5 to 8, respectively. Water content in soil of less than 10% brought about the death of the bacteria within 70 days, while water content of more than 40% maintained bacteria life for 726 days. The bacteria were easily killed by ultraviolet rays at 465 mu W/cm2 for 7.75 min while other permanent soil bacteria were killed at 1,860 mu W/cm2 for 31 min. From these results, it could be concluded that proper temperature, enough water in soil, and suitable soil pH might be the three major ecological conditions governing the environmental presence of B. pseudomallei.