Evaluation of Silver Nanoparticle Toxicity in Skin in Vivo and Keratinocytes in Vitro

IntroductionProducts using the antimicrobial properties of silver nanoparticles (Ag-nps) may be found in health and consumer products that routinely contact skin.ObjectivesThis study was designed to assess the potential cytotoxicity of Ag-nps in human epidermal keratinocytes (HEKs) and their inflammatory and penetrating potential into porcine skin in vivo.Materials and MethodsWe used eight different Ag-nps in this study [unwashed/uncoated (20, 50, and 80 nm particle diameter), washed/uncoated (20, 50, and 80 nm), and carbon-coated (25 and 35 nm)]. Skin was dosed topically for 14 consecutive days. HEK viability was assessed by MTT, alamarBlue (aB), and CellTiter 96 AQueous One (96AQ). Release of the proinflammatory mediators interleukin (IL)-1β, IL-6, IL-8, IL-10, and tumor necrosis factor-α (TNF-α) were measured.ResultsThe effect of the unwashed Ag-nps on HEK viability after a 24-hr exposure indicated a significant dose-dependent decrease (p < 0.05) at 0.34 μg/mL with aB and 96AQ and at 1.7 μg/mL with MTT. However, both the washed Ag-nps and carbon-coated Ag-nps showed no significant decrease in viability at any concentration assessed by any of the three assays. For each of the unwashed Ag-nps, we noted a significant increase (p < 0.05) in IL-1β, IL-6, IL-8, and TNF-α concentrations. We observed localization of all Ag-nps in cytoplasmic vacuoles of HEKs. Macroscopic observations showed no gross irritation in porcine skin, whereas microscopic and ultrastructural observations showed areas of focal inflammation and localization of Ag-nps on the surface and in the upper stratum corneum layers of the skin.ConclusionThis study provides a better understanding Ag-nps safety in vitro as well as in vivo and a basis for occupational and risk assessment. Ag-nps are nontoxic when dosed in washed Ag-nps solutions or carbon coated

Seroprevalence of Toxoplasma gondii infection among veterinary staff in Ontario, Canada (2002): Implications for teratogenic risk

BACKGROUND: Toxoplasma gondii infection is embryotoxic in humans. It is mainly transmitted through raw/undercooked meat and ingestion of oocysts in cat feces. There remains controversy about the actual risk of cats transmitting the disease to humans. Our primary objective was to determine the seroprevalence of T. gondii antibody among veterinary staff, to ascertain whether they have an increased risk through occupational exposure. Our secondary objective was to examine their practices regarding cats, toxoplasma infection, and pregnancy. METHODS: Veterinary staff attending the 2002 Annual Ontario Veterinary Medical Association Conference were invited to discuss their toxoplasma seroprevalence. Interested attendees completed a questionnaire and a physician drew blood samples to determine T. gondii titres using the ELISA IgG test. RESULTS: We collected 161 completed questionnaires, and 141 blood samples. There were 20 (14.2%, CI95%:8.4–19.9%) reactive titres among the veterinarian staff (80% females aged 30–45). All were regularly exposed to cats, washed their hands when in contact and few wore gloves routinely. CONCLUSIONS: These findings of low positive rates may be used to reassure veterinary staff that their exposure to cats does not appear to increase their risk of contracting toxoplasma infection and that pregnant women are not at an increased risk by owning a cat

Breast cancer in kurdish women of northern Iraq: incidence, clinical stage, and case control analysis of parity and family risk

<p>Abstract</p> <p>Background</p> <p>Breast cancer in the Middle-East occurs in relatively young women and frequently presents as advanced disease. A protective effect of multiparity is not apparent, and high familial risk is reported in some countries. This study investigates breast cancer rates and clinical stage related to age in the Kurdish region of Iraq and evaluates risk associated with parity and family history. Findings are compared with nearby countries and the West.</p> <p>Methods</p> <p>Sulaimaniyah Directorate of Health records identified 539 women diagnosed with breast cancer during 2006-2008. Clinical survey forms were completed on 296 patients and on 254 age-matched controls. Age specific incidence rates were calculated from Directorate of Health population estimates.</p> <p>Results</p> <p>Average patient age was 47.4 ± 11 years and 59.5% were pre-menopausal. Diagnosis was at clinical stage 1 for 4.1%, stage 2 for 43.5%, stage 3 for 26.0%, and stage 4 for 8.1% of patients. For 18.2%, stage was unknown. Annual breast cancer incidence rates per 100,000 women peaked at 168.9 at age 55 to 59 and declined to 57.3 at 60 and above. Patients had an average of 5.0 ± 3.3 children compared to 5.4 ± 3.5 for controls, <it>P </it>= 0.16. A first degree family member had breast cancer among 11.1% of patients and 2.1% of controls (<it>P </it>< 0.001) with > 50% of these patients and controls being ≥50 years old. No statistically significant relationship was found between tumor stage and age, <it>P </it>= 0.59.</p> <p>Conclusions</p> <p>In Kurdish Iraq, breast cancer is predominantly a disease of pre-menopausal women having multiple pregnancies. For younger patients, breast cancer incidence was similar to the West and possibly higher than many Middle-Eastern countries, but unlike the West, the estimated rates declined markedly in the elderly. The familial breast cancer risk for both older and younger women was within the general population risk of Western countries. Clinical stages were advanced and indicated delays in diagnosis that were unrelated to patient age.</p

Subclinical Thyroid Disorders and Cognitive Performance Among Adolescents in the United States

Background: Thyroid hormone plays a crucial role in the growth and function of the central nervous system. The purpose of the study was to examine the relationships between the status of subclinical thyroid conditions and cognition among adolescents in the United States. Methods: Study sample included 1,327 adolescents 13 to 16 years old who participated in the Third National Health and Nutrition Examination Survey (NHANES III). Serum thyroxine (T4) and thyroid stimulating hormone (TSH) were measured and subclinical hypothyroidism, subclinical hyperthyroidism, and euthyroid groups were defined. Cognitive performance was assessed using the subscales of the Wide Range Achievement Test-Revised (WRAT-R) and the Wechsler Intelligence Scale for Children-Revised (WISC-R). The age-corrected scaled scores for arithmetic, reading, block design, and digit span were derived from the cognitive assessments. Results: Subclinical hypothyroidism was found in 1.7% and subclinical hyperthyroidism was found in 2.3% of the adolescents. Cognitive assessment scores on average tended to be lower in adolescents with subclinical hyperthyroidism and higher in those with subclinical hypothyroidism than the score for the euthyroid group. Adolescents with subclinical hypothyroidism had significantly better scores in block design and reading than the euthyroid subjects even after adjustment for a number of variables including sex, age, and family income level. Conclusion: Subclinical hypothyroidism was associated with better performance in some areas of cognitive functions while subclinical hyperthyroidism could be a potential risk factor

Binary and Millisecond Pulsars at the New Millennium

We review the properties and applications of binary and millisecond pulsars. Our knowledge of these exciting objects has greatly increased in recent years, mainly due to successful surveys which have brought the known pulsar population to over 1300. There are now 56 binary and millisecond pulsars in the Galactic disk and a further 47 in globular clusters. This review is concerned primarily with the results and spin-offs from these surveys which are of particular interest to the relativity community.Comment: 59 pages, 26 figures, 5 tables. Accepted for publication in Living Reviews in Relativity (http://www.livingreviews.org

Lead exposure and periodontitis in US adults

Lead is known to have significant effects on bone metabolism and the immune system. This study tested the hypothesis that lead exposure affects periodontitis in adults. Material and Methods:  This study used the data from the Third National Health and Nutrition Examination Survey (NHANES III, 1988–94). It analyzed data from 2500 men and 2399 women, 20–56 yr old, who received complete periodontal examination. Periodontitis was defined as the presence of > 20% of mesial sites with ≥ 4 mm of attachment loss. Lead exposure was grouped into three categories:  7 μg/dL. Covariates were cotinine levels, poverty ratio, race/ethnicity, education, bone mineral density, diabetes, calcium intake, dental visit, and menopause (for women). All analyses were performed separately for men and women and considering the effect design. Univariate, bivariate, and stratified analysis was followed by multivariable analysis by estimating prevalence ratios through poisson regression. Results:  After adjustment for confounders, the prevalence ratios, comparing those with a lead blood level of > 7 μg/dL to those with a lead blood level of < 3 μg/dL was 1.70 (95% confidence interval (CI): 1.02, 2.85) for men and 3.80 (95% CI: 1.66, 8.73) for women. Conclusion:  The lead blood level was positively and statistically associated with periodontitis for both men and women. Considering the public health importance of periodontitis and lead exposure, further studies are necessary to confirm this association.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65253/1/j.1600-0765.2006.00913.x.pd

Cholesterol treatment with statins: Who is left out and who makes it to goal?

<p>Abstract</p> <p>Background</p> <p>Whether patient socio-demographic characteristics (age, sex, race/ethnicity, income, and education) are independently associated with failure to receive indicated statin therapy and/or to achieve low density lipoprotein cholesterol (LDL-C) therapy goals are not known. We examined socio-demographic factors associated with a) eligibility for statin therapy among those not on statins, and b) achievement of statin therapy goals.</p> <p>Methods</p> <p>Adults (21-79 years) participating in the United States (US) National Health and Nutrition Examination Surveys, 1999-2006 were studied. Statin eligibility and achievement of target LDL-C was assessed using the US Third Adult Treatment Panel (ATP III) on Treatment of High Cholesterol guidelines.</p> <p>Results</p> <p>Among 6,043 participants not taking statins, 10.4% were eligible. Adjusted predictors of statin eligibility among statin non-users were being older, male, poorer, and less educated. Hispanics were less likely to be eligible but not using statins, an effect that became non-significant with adjustment for language usually spoken at home. Among 537 persons taking statins, 81% were at LDL-C goal. Adjusted predictors of goal failure among statin users were being male and poorer. These risks were not attenuated by adjustment for healthcare access or utilization.</p> <p>Conclusion</p> <p>Among person's not taking statins, the socio-economically disadvantaged are more likely to be eligible and among those on statins, the socio-economically disadvantaged are less likely to achieve statin treatment goals. Further study is needed to identify specific amenable patient and/or physician factors that contribute to these disparities.</p

Care seeking behaviour and barriers to accessing services for sexually transmitted infections among female sex workers in Laos: a cross-sectional study

<p>Abstract</p> <p>Background</p> <p>Prompt, correct diagnosis and treatment with health information are essential components of reproductive tract infection (RTI) and sexually transmitted infection (STI) services. This study aims to describe care seeking behaviour and barriers to accessing RTI/STI services among female sex workers (FSWs) in Laos.</p> <p>Methods</p> <p>A cross-sectional survey using closed and open-ended questions was performed in six districts along Road 9, traversing Savannakhet province from Thailand to Vietnam. In total, 407 FSWs were interviewed. The data were analyzed and presented descriptively. Multiple logistic regression analysis was applied to assess associations between respondents' background characteristics and care seeking behaviour.</p> <p>Results</p> <p>About half of the respondents (49%) were less than or equal to 19 years of age, and 50% had started or completed secondary school. Fifty-eight percent had been engaged in sex work for less than 1 year. Eighty-six percent of the respondents reported RTI/STI signs or symptoms currently or in the last 3 months but only two-thirds of those with symptoms sought treatment. Source of treatment for the last RTI/STI episode was the drop-in centre (53%) followed by a public hospital (23%), private clinic (12%), private pharmacy (9%), and herbalist (2%). The main barriers to service use were long waiting time, inconvenient location of the clinic, not knowing where to get the services needed, and negative attitudes among healthcare providers. Care seeking behaviour was associated with longer duration of sex work (OR = 2.6, 95%CI 1.52-5.36). Forty-four percent received health information from peer educators, 34% from fellow friends, 26% from a pimp, and 26% had received information from a healthcare provider during the visit.</p> <p>Conclusion</p> <p>There were several barriers to accessing RTI/STI services and they were related to both structural and individual factors. Innovative STI service strategies to inform FSWs about the importance of early diagnosis and treatment should be established. Continuous training for STI service providers focusing on counseling skills and awareness of the sexual health care needs for FSWs is recommended in order to minimize the barriers experienced by FSWs in this particular setting.</p