The impact of material surface roughness and temperature on the adhesion of Legionella pneumophila to contact surfaces

The adhesion of bacterial cells to various surfaces is based on physical and chemical interactions between the micro-organisms and the surfaces. The main purpose of this research is to determine the effect of material roughness and incubation temperature on the adhesion of bacteria. To determine the adhesion of the bacterial strain of Legionella pneumophila ATCC 33153 to the glass coupons, a spectrophotometric method of measuring the optical density of crystal violet dye that is released from pre-stained bacterial cells attached to the test surface was used. The intensity of adhesion is in positive correlation to the increase in surface roughness (p < 0.05). The adhesion is the greatest at an optimal temperature of 36 °C, whereas the temperature of 15 °C has a bacteriostatic effect and the temperature of 55 °C a bactericidal effect.     

Escherichia coli biofilm formation and dispersion under hydrodynamic conditions on metal surfaces

The aim of this study was to analyze the impact of hydrodynamic forces on the multiplication of E. coli, and biofilm formation and dispersion. The experiments were provided in a flow chamber simulating a cleaning-in-place system. Biofilm biomass was measured using a crystal violet dye method. The results show that hydrodynamic forces affect not only biofilm formation and dispersion but the multiplication of E. coli in the first place. We found more biofilm biomass on the rough surface than on the smooth one. The results of the biofilm formation test show that laminar flow promotes the biofilm growth over 72 h, meanwhile turbulent flow after 48 h causes decrease in biomass. The results of the biofilm dispersion test, in contrast, show that laminar flow removed less biofilm from both materials that turbulent flow did. Therefore, taking into account these findings in cleaning-in-place technology can substantially reduce E. coli multiplication and biofilm formation.     

Real-Time PCR Investigation of the Dynamic Expression of Three “RNA Processing and Modification” Genes of Phanerochaete chrysosporium Exposed to Lead

The expression of three ribosome binding proteins namely; polyadenylate-binding protein, splicing factor RNPS1 and ATP-dependent RNA helicase of Phanerochaete chrysosporium exposed to lead were analyzed by real-time PCR. The mRNA level of splicing factor RNPS1 showed 2.7 (p < 0.05), 2.6 (p < 0.05) and 4.9-fold (p < 0.001) increase when the cells were exposed to 25, 50 and 100 μM lead, respectively. 50 and 100 μM lead exposure resulted in almost 2-fold (p < 0.01and p < 0.05, respectively) increase in the expression of ATP-dependent RNA helicase. Polyadenylate-binding protein mRNA levels did not reveal any significant increase when cells exposed to the concentrations of lead employed. However, the mRNA level of polyadenylate-binding protein and splicing factor RNPS1 within a period of 1 and 2 h temporal exposure to 100 μM lead showed 2.5 (p < 0.001) and 3.4-fold (p < 0.001) increase, respectively. Expression level of ATP-dependent RNA helicase was not affected from the period of exposure to this metal.     

Induction of Necrosis in Human Liver Tumor Cells by α-Phellandrene

α-Phellandrene (α-PA) is a component of dietary spices and herbs. The effect of α-PA on anticancer is unclear. This study aims to investigate the effects of α-PA on liver tumor cell death fate. Human liver tumor (J5) cells were incubated with α-PA and analyzed for cell cycle distribution, expression of Bax, Bcl-2, poly (ADP-ribose) polymerase (PARP) protein, and caspase-3 activity of J5 cells, and levels of nitric oxide (NO) production, lactate dehydrogenase (LDH) leakage, and ATP depletion were also analyzed in this study. Results found that α-PA significantly (P < 0.05) decreased the cell viability of J5 cells after 24-h treatment. The cell cycle distribution, Bax, Bcl-2, PARP protein levels, and caspase-3 activity of J5 cells did not change for 24 h after treatment with 30 μM α-PA. Reactive oxygen species levels significantly increased, mitochondrial membrane potential levels significantly decreased when J5 cells were treated with 30 μM α-PA for 24 h (P < 0.05). Thirty μM α-PA significantly (P < 0.05) increased the necrotic cell number, NO production, LDH leakage, and ATP depletion after 24 h of incubation. These results suggest that α-PA induced J5 cell necrosis but not apoptosis, and α-PA-induced necrosis possibly involved ATP depletion.     

Antibacterial and Antiinflammatory Kinetics of Curcumin as a Potential Antimucositis Agent in Cancer Patients

The antiinflammatory agent curcumin (diferuloylmethane) has a potential to mitigate cancer therapy-induced mucositis. We assessed the in vitro extent of its bactericidal activity and determined the kinetics of its antiinflammatory effect on pharyngeal cells. Bactericidal activity was assessed using the LIVE/DEAD® Kit after 4 h of exposure to curcumin (50–200 μM) in 18 oropharyngeal species commonly associated with bacteremia in febrile neutropenia. Moraxella catarrhalis or its outer membrane vesicles were used to determine the inhibitory effect of curcumin on bacteria-induced proinflammatory activity as determined by cytokine release into the supernatant of Detroit 562 pharyngeal cells using the Luminex® xMAP® technology. Curcumin exerted a concentration-dependent bactericidal effect on all 18 species tested. After 4 h at 200 μM, 12 species tested were completely killed. Preincubation of Detroit cells with 200 μM curcumin for 5 to 60 min resulted in complete suppression of the release of tumor necrosis factor-α, interleukin (IL)-6, IL-8, monocyte chemoattractant protein 1, granulocyte macrophage-colony stimulating factor, and vascular endothelial growth factor. Fibroblast growth factor-2 and interferon-γ were not affected. Repetitive exposure to curcumin resulted in repetitive suppression of cytokine/chemokine expression lasting from 4 to 6 h. Through reduction of oral microbial density as well as suppression of inflammation cascades curcumin may prevent cancer therapy-induced oral mucositis, e.g., when applied as multiple daily mouth washes.     

Temporal Evolution of Exposure to Mercury in Riverside Communities in the Tapajós Basin, from 1994 to 2010

Our objective was to evaluate the temporal evolution of mercury exposure in two riverside communities, Barreiras and São Luiz do Tapajós, downstream of gold mining areas in the Tapajós basin, Brazilian Amazon. The quantification of mercury in hair sample was made by atomic absorption spectrophotometry in the period between 1994 and 2010. In São Luiz do Tapajós the mercury exposure varied, in log units, from the peak of 1.21 ± 0.03 μg/g in 1996 to 1.16 ± 0.07 μg/g in 2007. Mercury exposure in Barreiras varied, in log units, from 1.25 ± 0.04 μg/g in 1994 to 1 ± 0.03 μg/g in 2010, peaking in 1995 at 1.25 ± 0.06 μg/g. Total mercury concentration found in both communities had no statistical differences across the years (p > 0.05) and they were higher than non-mercury exposed communities in Brazil and in South America. We concluded that the mercury exposure in the Tapajós basin is more than regulatory levels or higher than the general population.     

Fine particulate matter (PM2.5) association with peripheral artery disease admissions in northeastern United States

Background: Current evidence, on the association of PM_2.5 and peripheral artery disease (PAD) is very sparse. Methods: We use novel PM_2.5 prediction models to investigate associations between chronic and acute PM_2.5 exposures and hospital PAD admissions across the northeast USA. Poisson regression analysis was preformed where daily admission counts in each zip code are regressed against both chronic and acute PM_2.5 exposure, temperature, socio-economic characteristics and time to control for seasonal patterns. Results: Positive significant associations were observed between both chronic and acute exposure to PM_2.5 and PAD hospitalizations. Every 10-μg/m³ increase in acute PM_2.5 exposure was associated with a 0.26 % increase in admissions (CI = 0.08 – 0.45 %) and every 10-μg/m³ increase in chronic PM _2.5 exposure was associated with a 4.4 % increase in admissions (CI = 3.50 – 5.35 %). Conclusions: The study supports the hypothesis that acute and chronic exposure to PM_2.5 can increase the risk of PAD.     

层流GICU物体表面消毒方法的比较及菌群检测

目的比较两种消毒剂对层流综合重症监护病房（GICU）高频接触物体表面的抑菌效果,为层流GICU选择合理的物体表面消毒方法提供临床依据;了解物体表面细菌的污染情况,为预防控制感染提供理论依据。方法对层流GICU住院患者床档、床头桌的物体表面（常规消毒前）,采集样本做细菌培养、鉴定,以了解层流GICU物体表面菌群分布。分别采用含有效氯500 mg/L消毒剂（常规组）、伽玛TM消毒湿巾（对照组）对层流GICU床单位周围物体表面进行消毒,比较两种消毒方法在消毒后的抑菌率和物体表面细菌总数合格率。结果常规消毒前共采集200份物体表面样本,分离细菌87株,细菌污染率43.50%。检出革兰阳性菌68株（78.16%）,以棒状杆菌（18株,26.47%）、金黄色葡萄球菌（16株,23.53%）、表皮葡萄球菌（16株,23.53%）为主;革兰阴性杆菌19株（21.84%）,以鲍曼不动杆菌为主（12株,63.16%）。进行物体表面消毒后10 min的抑菌率,常规组为（94.89±7.72）%,对照组为（96.33±12.88）%,两组差异无统计学意义（P>0.05）;两组物体表面细菌总数合格率均为100%。结论定期对层流GICU住院患者床单位周围物体表面进行检测、消毒,并规范医护人员的操作及手卫生执行力,是切断细菌传播,预防医院感染简单、有效的方法。     

Impact of biomass burning and weather conditions on children’s health in a city of Western Amazon region

During the dry season in Brazilian Amazon, the population experiences severe smoke haze pollution in a region called “Arc of Devastation.” The increased pollution loading in the Amazonian atmosphere due to biomass burning emissions contributes significantly to global emissions of gases and particulate matter with important ecosystem and health impacts on local and regional populations. The aim of this study is to assess the lag structure among biomass burning air pollution exposure and environmental factors on children’s health in the municipality of Rio Branco, southwestern region of the Brazilian Amazon. In this paper, Poisson regressions via transfer function models were used and compared to polynomial distributed lag models to analyze the lagged and cumulative impacts of fine particulate matter and humidity exposure on daily demand of children’s hospital admissions due to respiratory causes from January 2004 to December 2009. Transfer function models presented better results. Increases of 10 μg/m³ in particles ≤ 2.5 μm/m3 aerodynamic diameter (PM_2.5) exposure were associated with 5.6 % (95 % CI, 3.64?7.31) increase in hospital admissions due to respiratory diseases at lag 2. Effects of PM_2.5 were acute and slight “harvesting” was found. Results demonstrate the adverse impact of biomass air pollution on health in the population, highlighting the need for public efforts to reduce this source of air pollution.     

Curcumin and Turmeric Modulate the Tumor-Promoting Effects of Iron In Vitro

Free or loosely chelated iron has tumor-promoting properties in vitro. Curcumin, a polyphenol derived from the food spice turmeric (Curcuma longa), is a potent antioxidant that binds iron. The primary aim of this study was to investigate whether curcuminoids prevent tumor-promoting effects of iron in T51B cells, a non-neoplastic rat liver epithelial cell line. Purified curcuminoids (curcumin) or a standardized turmeric extract similarly reduced oxidative stress and cytotoxicity associated with iron overload (IC₅₀ values near 10 μM, P < 0.05). Inhibition of iron-induced tumor promotion (seen upon treatment with 200 μM ferric ammonium citrate ± curcumin/turmeric for 16 wk in culture; subsequently assayed by soft agar colony formation) was nearly complete at 20 μM of total curcuminoids (P < 0.05), a concentration predicted to only partially chelate the added iron. Surprisingly, lower curcumin concentrations (10 μM) increased tumor promotion (P < 0.01). Curcuminoids delivered as a standardized turmeric extract were taken up better by cells, had a longer half-life, and appeared more effective in blocking tumor promotion (P < 0.01), suggesting enhanced curcuminoid delivery to cells in culture. The primary finding that curcuminoids can inhibit tumor promotion caused by iron in T51B cells is tempered by evidence for an underlying increase in neoplastic transformation at lower concentrations.     

Functional separation of septic and aseptic surgical procedures

Current evidence does not favour constructional over functional separation of septic and aseptic surgical procedures in terms of overall hygiene maintenance and incidence of skin and soft tissue infections. In both laminar and turbulent flow air operating theatres, air is not a relevant source of pathogens if surface disinfection is carried out properly.Final cleaning after a septic procedure includes a thorough wipe-disinfection of all potentially contaminated near and distant surfaces, including maintaining the necessary and effective exposure time of the chosen surface disinfectant. Cleaning utensils and clothes of all team members must be disposed of before leaving the theatre, and a complete change of gowns is mandatory before re-entering the operating room area. Strict adherence to this code of behaviour will allow for efficient functional separation of clean and contaminated surgical procedures without compromising patient safety.     

Toxicity, Feeding Rate and Growth Rate Response to Sub-lethal Concentrations of Anthracene and Benzo [a] Pyrene in Milkfish Chanos chanos (Forskkal)

The feeding rate, growth rate and gross conversion efficiency were studied in milkfish Chanos chanos for 28 days of exposure to sub-lethal concentrations of anthracene (1.00, 2.00, 3.00, 6.00 and 12.0 μg l^?1) and benzo [a] pyrene (0.30, 0.70, 1.40, 2.80 and 5.60 μg l^?1) under continuous flow through bioassays. Based on survival and growth data, No Observed Effect Concentration; Lowest Observed Effect Concentration were estimated after 28 days, the values for anthracene were 2.03 and 3.09 μg l^?1, and the values for benzo [a] pyrene were 0.82 and 1.46 μg l^?1, respectively. Anthracene and benzo [a] pyrene exposure caused reduction in feeding and growth rate.     

Diallyl Sulfide Promotes Cell-Cycle Arrest Through the p53 Expression and Triggers Induction of Apoptosis Via Caspase- and Mitochondria-Dependent Signaling Pathways in Human Cervical Cancer Ca Ski Cells

Diallyl sulfide (DAS) is a component of garlic (Alliaceae family). Although diallyl polysulfide has been shown to exhibit anticancer activities, no report explored DAS-affected cell death in human cervical cancer cells in vitro. This study investigated DAS affected on cell-cycle regulation and apoptosis in human cervical cancer Ca Ski cells. DAS at 25–100 μM decreased the viability of Ca Ski cells by increasing G0/G1 phase arrest followed by induction of apoptosis in concentration- and time-dependent effects. Flow cytomteric assay indicated that DAS (75 μM) promoted the production of Ca²⁺ accumulation and decreased the level of mitochondrial membrane potential in Ca Ski cells. Western blotting showed that 75 μM of DAS-induced G0/G1 phase arrest was mediated through the increased expression of p21, p27, and p53 with a simultaneous decrease in CDK2, CDK6, and CHK2 expression. The characteristics of apoptosis, such as morphological changes and DNA condensation, altered the ratio of Bax/Bcl-2 and sub-G1 phase occurred in Ca Ski cells after exposure to DAS. Furthermore, DAS induced mitochondrial dysfunction, leading to the release of cytochrome c for causing apoptosis in Ca Ski cells. These findings suggest that DAS might be a potential chemotherapeutic agent for the treatment of cervical cancer.     

Genotoxic and Cytotoxic Evaluation of Pyrethroid Insecticides λ-Cyhalothrin and α-Cypermethrin on Human Blood Lymphocyte Culture

The present study aimed to investigate the genotoxic, cytotoxic and aneugenic effects of 1, 2, 3.75, 7.5, 15, 30 μM concentrations of the insecticides λ-cyhalothrin (LCT) and α-cypermethrin (CYP) on human peripheral blood lymphocyte culture using micronucleus (MN) and fluorescence in situ hybridisation (FISH) methods. All the concentrations were tested to assess the MN and apoptosis effects, and 1 and 2 μM LCT and 7.5 and 15 μM CYP concentrations were tested for FISH analysis. The cytotoxic effect was also observed using trypan blue and the acridine orange/ethidium bromide fluorescence staining method to measure the apoptotic effect. It was observed that both of the insecticides had a cytotoxic effect at all the concentrations (p ≤ 0.001) and apoptotic effect for LCT at 15–30 μM (p ≤ 0.05; p ≤ 0.01) for CYP between 2 and 30 μM concentrations (p ≤ 0.05; p ≤ 0.01). The micronuclei that developed after exposure were induced because of an aneugenic effect (p ≤ 0.001). LCT and CYP might be spindle poisons or caused damaged to centromere/kinetochore function.     

Prospective evaluation of respiratory health benefits from reduced exposure to airborne particulate matter

We aimed to investigate if short-term exposure to reduced particulate matter (PM) air pollution would affect respiratory function in healthy adults. We followed a cohort of 42 healthy participants from a community afflicted with severe PM air pollution to a substantially less polluted area for nine days. We measured daily airborne PM [with an aerodynamic diameter of less than 2.5 μm (PM_2.5) and 10 μm (PM₁₀)] and PM_2.5 carbon component concentrations. Five repeated respiratory function measurements and fractional exhaled nitric oxide test were made for each participant. Associations between respiratory health and PM exposure were assessed using linear mixed models. Each 10 μg/m³ decrease in same-day PM_2.5 was associated with small but consistent increase in the forced expiratory volume in 1 s (FEV₁) (9.00 mL) and forced vital capacity (14.35 mL). Our observations indicate that respiratory health benefits can be achieved even after a short-term reduction of exposure to PM. Our results provide strong evidence for more rigorous air pollution controls for the health benefit of populations.     

Flavonoid-Enriched Apple Fraction AF4 Induces Cell Cycle Arrest,DNA Topoisomerase II Inhibition,and Apoptosis in Human Liver Cancer HepG2 Cells

Apples are a major source of dietary phytochemicals such as flavonoids in the Western diet. Here we report anticancer properties and possible mechanism of action of apple flavonoid-enriched fraction (AF4) isolated from the peels of Northern Spy apples in human hepatocellular carcinoma cells, HepG2. Treatment with AF4 induced cell growth inhibition in HepG2 cells in time- and dose-dependent manner. Concentration of 50 μg/ml (50 μg total monomeric polyphenols/ml) AF4 was sufficient to induce a significant reduction in cell viability within 6 h of treatment (92%, P < 0.05) but had very low toxicity (minimum 4% to maximum 16%) on primary liver and lung cells, which was significantly lower than currently prescribed chemotherapy drug Sorafenib (minimum 29% to maximum 49%, P < 0.05). AF4 induced apoptosis in HepG2 cells within 6 h of treatment via activation of caspase-3. Cell cycle analysis via flow-cytometer showed that AF4 induced G2/M phase arrest. Further, results showed that AF4 acts as a strong DNA topoisomerase II catalytic inhibitor, which may be a plausible reason to drive the cells to apoptosis. Overall, our data suggests that AF4 possesses a significantly stronger antiproliferative and specific action than Sorafenib in vitro and is a potential natural chemotherapy agent for treatment of liver cancer.     

Assessment of mercury in muscle of fish from Cartagena Bay,a tropical estuary at the north of Colombia

Fish belonging to several trophic levels from Cartagena Bay, a tropical estuary, were collected and analyzed for total mercury (T-Hg) concentrations in muscle. T-Hg concentrations varied from 0.010–0.526 μg/g, and the overall average was 0.051 ± 0.002 μg/g. Carnivorous species presented the highest T-Hg mean value (0.100 ± 0.006 μg/g), followed by omnivorous (0.076 ± 0.014 μg/g) and detritivorous (0.028 ± 0.001 μg/g). The relationships between weight and T-Hg content were found for the carnivorous species Sciades herzbergi (r = 0.508, p < 0.001) and not for the detritivorous Mugil incilis (r = 0.086, p = 0.207). Although results suggest fish from the bay pose a low health threat for humans in terms of Hg exposure, vulnerable groups such as pregnant women, should avoid eating large size carnivorous species. Knowledge about species with low Hg content should be widespread within fishing communities, guaranteeing adequate nutrition by including fish in the diet and reducing the risk of Hg poisoning.     

Identifying occupational and nonoccupational exposure to mercury in dental personnel

The objective of this study was to investigate the occupational and nonoccupational exposure to mercury (Hg) vapor in dental personnel by examining the relationships between blood mercury, urine mercury, and their ratio with air mercury. The method was performed on 50 occupational exposed and 50 unexposed controls (25 men and 25 women). The mercury concentrations in air and human biological samples were determined based on the National Institute for Occupational Safety and Health (NIOSH) method and standard method (SM) by a new mode of liquid-phase microextraction, respectively. The mean mercury concentrations in urine (μg Hg⁰/g creatinine) and blood were significantly higher than control group, respectively (19.41 ± 5.18 vs 2.15 ± 0.07 μg/g and 16.40 ± 4.97 vs 2.50 ± 0.02 μg/L) (p <.001). The relationships between mercury concentration in blood/urine ratio (r = .380) with dental office air are new indicators for assessing occupational exposure in dental personnel.     

Health and carcinogenic risk evaluation for cohorts exposed to PAHs in petrochemical workplaces in Rawalpindi city (Pakistan)

This study presents the analyses of urinary biomarkers (1-OHPyr, α- and β-naphthols) of polycyclic aromatic hydrocarbons (PAHs) exposure and biomarkers of effect (i.e. blood parameters) in petroleum-refinery workers (RFs) and auto-repair workers (MCs). Exposed subjects had higher concentrations of white blood cell (WBC) count than control subjects (CN) subjects (5.31 × 10³ μL^?1 in exposed vs. 5.15 × 10³ μL^?1 in CN subjects), while the biomarker of oxidative DNA damage (8-OHdG) was significantly higher in MCs. The exposure among these two cohorts could be influenced by the ambience of the workplaces; in fact, MCs’ shops are relatively damp and enclosed workplaces in comparison with the indoor environment of refineries. PAHs in the dust samples from mechanical workshops probably originated from mixed sources (traffic exhaust and petroleum spills), while the incremental lifetime cancer risk (ILCR) for MCs showed moderate-to-low cancer risk from exposure to dust-bound PAHs. The study shows that increasing PAH exposure can be traced in MC workstations and needs to be investigated for the safety of public health.