The effects of prognostic factors on transplant and mortality of patients with end-stage liver disease using Markov multistate model.

Background: Decompensated cirrhosis patients have a high risk of death which can be considerably reduced with liver transplantation (LT). This study aimed to simultaneously investigate the effect of some patients' characteristics on mortality among those with/without LT and also LT incident. Materials and Methods: In this historical cohort study, the information from 780 eligible patients aged 18 years or older was analyzed by the Markov multistate model; they had been listed between 2008 and 2014, needed a single organ for initial orthotopic LT, and followed at least for up to 5 years. Results: With a median survival time of 6 (5-8) years, there were 275 (35%) deaths. From 255 (33%) patients who had LT, 55 (21%) subsequently died. Factors associated with a higher risk of mortality and LT occurrence were included: higher model for end-stage liver disease (MELD) score (hazard ratio [HR] = 1.16, confidence interval [CI]: 1.09-1.24 and HR = 1.22, CI: 1.41-1.30) and ascites complication (HR = 2.34, CI: 1.74-3.16 and HR = 11.43, CI: 8.64-15.12). Older age (HR = 1.03, CI: 1.01-1.06), higher creatinine (HR = 6.87, CI: 1.45-32.56), and autoimmune disease versus hepatitis (HR = 2.53, CI: 1.12-5.73) were associated with increased risk of mortality after LT. Conclusion: The MELD and ascites are influential factors on waiting list mortality and occurrence of LT. Total life expectancy is not influenced by higher MELD.

Spatio-temporal analysis of misaligned burden of disease data using a geo-statistical approach.

Data used to estimate the burden of diseases (BOD) are usually sparse, noisy, and heterogeneous. These data are collected from surveys, registries, and systematic reviews that have different areal units, are conducted at different times, and are reported for different age groups. In this study, we developed a Bayesian geo-statistical model to combine aggregated sparse, noisy BOD data from different sources with misaligned areal units. Our model incorporates the correlation of space, time, and age to estimate health indicators for areas with no data or a small number of observations. The model also considers the heterogeneity of data sources and the measurement errors of input data in the final estimates and uncertainty intervals. We applied the model to combine data from nine different sources of body mass index in a national and sub-national BOD study. The cross-validation results confirmed a high out-of-sample predictive ability in sparse and noisy data. The proposed model can be used by other BOD studies especially at the sub-national level when the areal units are subject to misalignment.

Investigating the effect of behavioral and demographic characteristics of Iranian women on the number of children ever born.

Background: The number of children ever born (CEB) to a woman, as an index of her fertility behavior, are interesting for the governments and demographer policymakers. In recent years, a notable reduction of fertility and population aging in Iran has caused concern among politicians, and it has led to starting new changes in demographic policies. Therefore, to adopting new demographic and health policies programs, identification of factors that affecting CEB is essential. Methods: To evaluate determinant factors on CEB, information of 20093 married Iranian women aged between 15 and 54 years has been analyzed from the Iranian National Institute of Health Research survey. Based on the structure of data and the possible influential unobserved population heterogeneity on CEB in each city and province, a multilevel count regression model was applied. The analysis was performed using the 'R' software (version 3.5) with a significant level of 0.05. Results: Findings show that the mean and median number of CEB was 2.82 and 2.00 for all women, respectively. Meanwhile, these values were 4.56 and 4.00 for the women who reached menopause. There was a significant unobserved heterogeneity affecting CEB in each province (σp=0.018). Also, the results of the multilevel model show that living in an urban area (RR=0.90), higher age at first marriage (RR=0.96), higher education (RR=0.84, RR=0.81), and exposure to mass media (RR=0.87) decrease the risk ratio of the number of CEB (p <0.001). Conclusion: It seems that the tendency of women to academic education and their access to mass media has a significant effect on reducing childbearing. Therefore, in future planning, attention to these two factors can be useful and helpful to move to increase fertility.

Methods of competing risks flexible parametric modeling for estimation of the risk of the first disease among HIV infected men.

BACKGROUND: Patients infected with the Human Immunodeficiency Virus (HIV) are susceptible to many diseases. In these patients, the occurrence of one disease alters the chance of contracting another. Under such circumstances, methods for competing risks are required. Recently, competing risks analyses in the scope of flexible parametric models have risen to address this requirement. These lesser-known analyses have considerable advantages over conventional methods. METHODS: Using data from Multi Centre AIDS Cohort Study (MACS), this paper reviews and applies methods of competing risks flexible parametric models to analyze the risk of the first disease (AIDS or non-AIDS) among HIV-infected patients. We compared two alternative subdistribution hazard flexible parametric models (SDHFPM1 and SDHFPM2) with the Fine & Gray model. To make a complete inference, we performed cause-specific hazard flexible parametric models for each event separately as well. RESULTS: Both SDHFPM1 and SDHFPM2 provided consistent results regarding the magnitude of coefficients and risk estimations compared with estimations obtained from the Fine & Gray model, However, competing risks flexible parametric models provided more efficient and smoother estimations for the baseline risks of the first disease. We found that age at HIV diagnosis indirectly affected the risk of AIDS as the first event by increasing the number of patients who experience a non-AIDS disease prior to AIDS among > 40 years. Other significant covariates had direct effects on the risks of AIDS and non-AIDS. DISCUSSION: The choice of an appropriate model depends on the research goals and computational challenges. The SDHFPM1 models each event separately and requires calculating censoring weights which is time-consuming. In contrast, SDHFPM2 models all events simultaneously and is more appropriate for large datasets, however, when the focus is on one particular event SDHFPM1 is more preferable.

Pattern and determinant factors of birth intervals among Iranian women: a semi-parametric multilevel survival model.

The interval between successive pregnancies (birth interval) is one of the main indexes used to evaluate the health of a mother and her child. This study evaluated birth intervals in Iran using data from the Iranian Multiple Indicators Demographic and Health Survey (IrMIDHS) conducted in 2010-2011. A total of 20,093 married Iranian women aged 15-54 years from the whole country constituted the study sample. Based on the nature of sampling and the unobserved population heterogeneity for birth intervals in each city and province, a multilevel survival frailty model was applied. Data were analysed for women's first three birth intervals. The median first and second birth intervals were 30.3 and 39.7 months respectively. Higher education, Caesarean delivery, contraceptive use and exposure to public mass media were found to decrease the hazard rate ratio (HRR) of giving birth. Meanwhile, higher monthly income increased the hazard of giving birth. The results suggest that public mass media can play an effective role in encouraging women to have the recommended birth interval. Furthermore, increasing family income could encourage Iranian couples to decrease the time to their next birth.

Estimating the Net Survival of Patients with Gastric Cancer in Iran in a Relative Survival Framework.

BACKGROUND: Iran is an Eastern Mediterranean region country with the highest rate of gastric cancer. The present study aimed to evaluate the 5-year net survival of patients with gastric cancer in Iran using a relative survival framework. METHODS: In a cross-sectional study, using life-table estimation of relative survival, we reported 1- to 5-year relative survival regarding age, sex, disease stage, pathology, and adjuvant therapies via modeling excess mortality. All the analyses were done applying Stata 11.2 with a confidence level of 95%. RESULTS: Data on 330 patients (aged 32-96 y), who were comprised of 228 (69.1%) men and 102 (30.1%) women with gastric cancer and were followed up for 10 years, were analyzed. Adenocarcinoma was the most common malignancy (281 [85.2%] patients), and 248 (75.1%) patients were at stage 3 or stage 4. The 1- and 5-year net survival rates after surgery were 67.96 (95% CI: 62.35-72.98) and 23.35 (95% CI: 17.94-29.28), respectively. Higher stages (P=0.001), older ages (P=0.007), and less use of adjuvant therapies (P<0.001) were independently associated with excess mortality. CONCLUSION: It is recommended to use the relative survival framework to analyze the survival of cancer patients as an alternative approach not only to eliminate biases due to competing risks and their dependencies but also to estimate the cure at the population level concerning the most important individual characteristics. Our findings showed that the survival rate of gastric cancer in Iran is lower than that in most developed countries in terms of net survival.

EBV and vitamin D status in relapsing-remitting multiple sclerosis patients with a unique cytokine signature.

Multiple sclerosis, a debilitating autoimmune and inflammatory disease of the central nervous system, is associated with both infectious and non-infectious factors. We investigated the role of EBV infection, vitamin D level, and cytokine signature in MS patients. Molecular and serological assays were used to investigate immune biomarkers, vitamin D level, and EBV status in 83 patients with relapsing-remitting multiple sclerosis and 62 healthy controls. In total, 98.8 % of MS patients showed a history of EBV exposure compared to 88.6 % in the healthy group (p = 0.005). EBV DNA load was significantly higher in MS patients than healthy subjects (p < 0.0001). Using a panel of biomarkers, we found a distinct transcriptional signature in MS patients compared to the healthy group with mRNA levels of CD73, IL-6, IL-23, IFN-γ, TNF-α, IL-15, IL-28, and IL-17 significantly elevated in MS patients (p < 0.0001). In contrast, the mRNA levels for TGF-ß, IDO, S1PR1, IL-10, and CCL-3 were significantly lower in MS patients compared to healthy controls (p < 0.0001). No significant differences were found with the mRNA levels of IL-13, CCL-5, and FOXP3. Interestingly, in MS patients we found an inverse correlation between vitamin D concentration and EBV load, but not EBNA-1 IgG antibody levels. Our data highlight biomarker correlates in MS patients together with a complex interplay between EBV replication and vitamin D levels.

Serum ghrelin levels and gender-related indices of body composition in prepubertal children: a cross-sectional study.

BACKGROUND: A wide variety of functions has been attributed to ghrelin, a peptide hormone secreted in the stomach. The objective of the study was to assess the association of ghrelin concentrations with body composition among Iranian children. METHODS: In this study, blood samples of 57 boys and 54 girls aged 6-10 were collected to measure ghrelin levels. Fat mass (FM) and fat-free mass (FFM) were examined by body composition analyzer. Actigraph GT3X was administered to assess children's physical activity and sleep. Data were analyzed using linear regression models. RESULTS: All measured parameters did not differ between genders except for sleep time which was higher and sleep efficacy which was lower in boys compared with girls. None of the FM and FFM indices studied in boys was significantly associated with ghrelin levels. In girls, however, ghrelin concentrations were significantly associated with FM (ß = 0.04, P = 0.01), fat mass index (ß = 0.07, P = 0.008), and fat-free mass index (ß = 0.08, P = 0.04) and near-significantly associated with FFM (ß = 0.03, P = 0.09) after adjusting for age, physical activity, sleep, and dietary intake. CONCLUSION: Girls with higher ghrelin levels were more likely to have increased total FM and FFM. Conversely, body composition was not associated with ghrelin levels in boys. Consequently, ghrelin may influence the gender-related differences of body composition during childhood in girls. But, further study is needed to confirm our findings.

How within-city socioeconomic disparities affect life expectancy? Results of Urban HEART in Tehran, Iran.

BACKGROUND: There is substantial lack of knowledge about the role of socioeconomic status (SES) indicators on life expectancy (LE) within-cities, especially within mega-cities. We aimed to investigate the disparities of LE within city districts of Tehran, Iran, and specify how SES inequalities play role on LE. METHODS: The death and population data for 2010 by different age, gender, and residency district were obtained from the main cemetery of Tehran and statistical centre of Iran, respectively. Age-specific mortality rates and consequently LE were calculated for all 22 districts by different genders. Finally, based on the results of first Tehran's Urban Health Equity Assessment and Response Tool (Urban HEART) project in 2008, the influence of social classes (SCs), total costs, and education indicators were analyzed on LE at birth (e0). RESULTS: The e0 for total males and females in Tehran were calculated as 74.6 and 78.4 years for 2010, respectively. The maximum LE of 80 years was observed in females of northern part with higher SES, and the minimum e0 of 72.7 years observed in males of southern part with lower SES. The e0 gender gap among districts was 5.5 years for females and 3.7 years for males. The highest and lowest mean of e0 observed in SC1 (highest class) and SC5 (lowest class), were 77.6 and 76.0 years, respectively. The lowest mean of e0 observed in the first group of total costs indicator and was 76.2 years. In addition, the lowest observed mean of e0 was in the first category of education indicator (illiterate) and was 76.0 years. CONCLUSION: RESULTS indicate substantial disparities in LE within city districts. This confirms that SES disparities within-cities would have direct influences on LE.

Developing criteria for cesarean section using the RAND appropriateness method.

BACKGROUND: Cesarean section rates are increasing worldwide, and a rapid increase has been observed in Iran. Disagreement exists between clinicians about when to use cesarean section. We aimed to identify the appropriateness criteria for the use of cesarean section in Iran. METHOD: A consensus development study using a modified version of the RAND Appropriateness Method (RAM). We generated scenarios from valid clinical guidelines and expert opinions. A panel of experts participated in consensus development: first round via mail (12 members), second round face-to-face (9 members). We followed the RAM recommendations for the development of the scenario lists, rating scales, and statistical analyses. RESULTS: 294 scenarios relevant to cesarean section were identified. 191 scenarios were considered appropriate, of which 125 scenarios were agreed upon. The panel found cesarean inappropriate for 21% of scenarios, and 'equivocal' for 14% of scenarios. CONCLUSION: RAM is useful for identifying stakeholder views in settings with limited resources. The participants' views on appropriateness of certain indications differed with available evidence. A large number of scenarios without agreement may partly explain why it has been difficult to curb the growth in cesarean section rate.

Post Liver Transplantation Survival and Related Prognostic Factors among Adult Recipients in Tehran Liver Transplant Center; 2002-2019.

BACKGROUND: Liver transplantation is a standard treatment for patients with end-stage liver disease (ESLD). However, with increasing demand for this treatment and limited resources, it is available only to patients who are more likely to survive. The primary aim was to determine prognostic factors for survival. METHODS: We collected data from 597 adult patients with ESLD, who received a single organ and initial orthotopic liver transplantation (OLT) in our center between 20 March 2008 and 20 March 2018. In this historical cohort study, univariate and multiple Cox model were used to determine prognostic factors of survival after transplantation. RESULTS: After a median follow-up of 825 (0-3889) days, 111 (19%) patients died. Survival rates were 88%, 85%, 82% and 79% at 90 days, 1 year, 3 years, and 5 years, respectively. Older patients (HR = 1.27; 95% CI: 1.01-1.59), presence of pre-OLT ascites (HR = 2.03; 95% CI: 1.16-3.57), pre-OLT hospitalization (HR = 1.88; 95% CI:1.02-3.46), longer operative time (HR = 1.006; 95% CI: 1.004-1.008), post-OLT dialysis (HR = 3.51; 95% CI: 2.07-5.94), cancer (HR = 2.69; 95% CI: 1.23-5.89) and AID (HR = 2.04; 95% CI: 1.17-3.56) as underlying disease versus hepatitis, and higher pre-OLT creatinine (HR = 1.67; 95% CI: 1.10-2.52) were associated with decreased survival. CONCLUSION: In this center, not only are survival outcomes excellent, but also younger patients, cases with better pre-operative health conditions, and those without complications after OLT have superior survival.

Effect of Cytomegalovirus Recombinant Phosphoprotein 150 (pp150) on Maturation and Function of Murine Dendritic Cells: an In-Vitro Study.

BACKGROUND: Tegument protein pp150 of cytomegaloviruses (CMVs) plays a vital role in all stages of viral life cycle, representing the most important tegument protein candidate for HCMV treatment. However, the exact role of pp150 in immune regulation is yet to be elucidated. OBJECTIVE: To examine the effects of pp150 on the maturity and function of murine dendritic cells (DCs). METHODS: Maturity status (CD40, CD86, and MHC-II expression) and phagocytic capacity of DCs (dextran uptake assay) were characterized. Gene expression profiles of ROR-γ, GATA-3, T-bet, and FOXP-3 as well as the protein expression of INF-γ (Th1), IL-4 (Th2), IL-35 (Treg), IL-17A (Th17), IL-22, TNF-α, IL-6, and IL-2 were evaluated in T cells co-cultured with DCs. RESULTS: A significant increase in CD40, CD86, and CCR7 expression and a reduction in the phagocytosis rate were observed in pp150-stimulated DCs compared with unstimulated DCs. T cells co-cultured with stimulated DCs showed higher expressions of ROR-γ, IL-6, IL-2, IL-17A, IL-22, and TNF-α. CONCLUSION: Despite improvements in maturity status, pp150-stimulated DCs did not seem to be able to induce Th1 or Th2 immunity. In fact, Th17 and its mediators, IL-17A and IL-22, might be the main inflammatory factors involved in pp150-stimulated DC's mechanism of action. However, it is necessary to conduct further investigations to corroborate these observations.

Clinicopathological features and survival of colorectal cancer patients younger than 50 years: a retrospective comparative study.

BACKGROUND: Colorectal cancer (CRC) is a disease of old age, but its incidence has been rising among younger population compared to older ones. Nevertheless, there is a controversy over survival of younger patients compared to the older ones. Therefore, in the current study, we investigated the clinicopathological features and survival of the younger (< 50 years) versus older (≥ 50 years) CRC patients. RESULTS: The younger and older groups consisted of 39.4% and 60.6% of patients, respectively. Both age groups were comparable regarding the symptom presentation and duration, and pre-operative carcinoembryonic antigen (CEA). The younger patients were diagnosed with a higher proportion of poorly differentiated (14.7% vs. 8.3%; p < 0.001) and more advanced tumors (53.2% vs. 45.9%; p = 0.266). The rectum tumor site was significantly more common among the younger patients (p = 0.021). The overall survival (OS) (p = 0.278), the cancer-specific survival (CSS) (p = 0.233), and the disease-free survival (DFS) (p = 0.497) did not differ significantly between the two groups. Based on Cox regression model, elevated pre-operative CEA level (HR = 1.41; 95%CI of 1.01-1.97), advanced tumor stage (6.06; 95%CI of 3.03-12.15), and poorly differentiated tumor (HR = 1.69; 95%CI of 1.05-2.71) were associated with decreased survival. CONCLUSIONS: The younger patients did not have poor prognosis compared to the older ones despite having an advanced tumor stage and a poor tumor differentiation.

Improved Function and Maturation of Dendritic Cells Stimulated by Recombinant pp65 Protein: An in-vitro Design.

BACKGROUND: Stimulated dendritic cells (DCs) have been shown to be effective in the induction of specific immune cells. Also, the CMV pp65 plays an important role in CMV life cycle and immune recognition. OBJECTIVE: To assess the effect of CMV pp65 on the maturity and function of dendritic cells. METHODS: Splenic DCs were treated with non-cytotoxic concentrations of the pp65 and analyzed for MHC II, CD86, and CD40 expression by flow cytometry. Then, ROR-γ, GATA3, T-bet, and FOXP3 gene expression levels were evaluated in T cells co-cultured with DCs using Real time-PCR. Finally, the effects of pp65 on allogenic T-cell responses in mixed lymphocyte culture (MLR), and the release of cytokines were investigated by ELISA and flow cytometry. RESULTS: The phagocytosis rate was significantly lower in the pp65-treated DCs than the non-stimulated DCs. There were significant differences in the raised level of CD40, CD86, and CCR7 in DCs as maturation markers. Furthermore, ROR-γ, and T-bet overexpression in T cells of the pp65-treated group compared with the non-stimulated group was observed. Significant differences were observed in the levels of IL-2, IL-6, IL-17, IL-22, TNF-α, and IFN-γ in pp65-stimulated groups compared with the non-stimulated DCs. CONCLUSIONS: The pp65-treated DCs can induce differentiation and functional activity of the cellular immune system, including Th17, and Th1, but not other major T-cell subsets such as Tregs, and Th2 population.

A Spatial Survival Model in Presence of Competing Risks for Iranian Gastrointestinal Cancer Patients

Background: Gastrointestinal cancer is one of the common causes of death from cancer in Iran. Survival analysis is usually used to detect prognostic factors of time to death from gastrointestinal cancers. The use of ordinary survival models, in the presence of competing risks and/or when data is collected within geographic areas, may lead to distorting the results. Therefore, the aim of this study is to use the spatial survival models in the presence of competing risks to assess the risk factors affecting the survival time of gastrointestinal cancer patients. Methods: The data in this study was collected from 602 patients who were diagnosed with gastrointestinal cancer in Golestan and Mazandaran provinces registered in Iran's National Institute of Health Research from 2002 through 2007 and were followed up to July 2017. The data was analyzed using the cause-specific hazard frailty model with multivariate conditional autoregressive distribution for frailties in the presence of competing risks (death from gastrointestinal cancer, heart disease, and other causes) via OpenBUGS software. Results: The hazard of death from gastrointestinal cancer in men patients, patients who lived in rural areas, patients whose relatives did not have a history of cancer, patients who did not undergo surgery, and patients with gastric cancer was significantly higher than others. Based on the deviance information criterion (DIC), frailty models and spatial frailty models seemed better than no-frailty model and non-spatial frailty model, respectively. Conclusions: This study showed that the use of the spatial frailty term in the model helps better fit the model. Also, the spatial pattern in the figures suggests the necessity of presence of some still missing, spatially varying covariates relevant for time to death from gastrointestinal cancer, heart disease, or other causes.

A trend analysis of surgical operations under a global payment system in Tehran, Iran (2005-2015).

BACKGROUND: Global payment system is a first example of per-case payment system that contains 60 commonly used surgical operations for which payment is based on the average cost per case in Iran. OBJECTIVE: The aim of the study was to determine the amount of reduction, increase or no change in the trend of global operations. METHODS: In this retrospective longitudinal study, data on the 60 primary global surgery codes was gathered from Tehran Health Insurance Organization within the ten-year period of 2005-2015 separately, for each month. Out of 60 surgery codes, only acceptable data for 46 codes were available based on the insurance documents sent by medical centers. A quantitative analysis of time series through Regression Analysis Model using STATA software v.11 was performed. RESULTS: Some global surgery codes had an upward trend and some were downwards. Of N Codes, N83, N20, N28, N63, and N93 had an upward trend (p<0.05) and N32, N43, N81 and N90 showed a significant downward trend (p<0.05). Similarly, all H Codes except for H18 had a significant upward trend (p<0.000). As such, K Codes including K45, K56 and K81 had an increasing movement. S Codes also experienced both increasing and decreasing trends. However, none of the O Codes changed according to time. Other global surgical codes like C61, E07, M51, L60, J98 (p<0.000), I84 (p<0.031) and I86 (p<0.000) shown upward and downward trends. Total global surgeries trend was significantly upwards (B=24.26109, p<0.000). CONCLUSION: The varying trend of global surgeries can partly reflect the behavior of service providers in order to increase their profits and minimize their costs.

Factors Affecting Long-Survival of Patients with Esophageal Cancer Using Non-Mixture Cure Fraction Model

Objective: Esophageal cancer (EC) is one of the gastrointestinal malignancies with a very high morbidity and mortality rate due to poor prognosis. This study aims to assess the effects of risk factors on survival and cure fraction of patients with EC in a population of Iranian patients using a non-mixture cure fraction model. Methods: This retrospective cohort study was conducted on 127 patients with EC who were diagnosed during 2009-2010 and were followed up for 5 years in East-Azarbaijan, Iran. Stepwise selection and non-mixture cure fraction model were used to find the risk factors of EC survival patients. Results: The mean (±standard deviation) diagnosis age of the EC was 66.92(±11.95). One, three and five-year survival probabilities were 0.44 (95% confidence interval (CI): 0.36-0.54), 0.2 (95% CI: 0.14-0.28) and 0.13 (95% CI: 0.08-0.2) respectively. Female sex (Estimate=-0.99; 95% confidence interval (CI): -1.41,-0.58; p-value<0.001), low level socioeconomic status (Estimate=0.39; 95%CI: 0.12,0.66; p-value=0.043), the group who did not do esophagectomy surgery (Estimate=0.58; 95%CI: 0.17,0.99; p-value=0.005) and unmarried group (Estimate=0.58; 95%CI: 0.11-1.05; p-value=0.015) were found as the significant predictor of survival and cure fraction of the EC patients. Population cure rate was 0.11 (95%CI: 0.07-0.19) and Cure fraction was estimated 5.11 percent. Conclusion: This study found gender, socioeconomic status, Esophagectomy surgery and marital status as the potential risk factors for survival and cure fraction of Iranian EC patients. Moreover, non- mixture cure fraction provides more accurate and more reliable insight into long-term advantages of EC therapy compared to standard classic survival analysis alternatives.

Virulence Determinants and Antimicrobial Resistance Patterns of Vancomycin-resistant Enterococcus faecium Isolated from Different Sources in Southwest Iran.

BACKGROUND: This study aimed to investigate the incidence of antibiotic-resistance and virulence genes in vancomycin-resistant Enterococcus faecium isolated from different sources in southwest Iran from Mar to Sep 2015. METHODS: Overall, 120 E. faecium isolates (80 VRE and 40 vancomycin-susceptible enterococci [VSE] isolates) were obtained from four hospitals. The resistance of the VRE isolates was determined by disk diffusion method. Multiplex PCR was performed to detect the virulence genes carried by the E. faecium isolates, namely, enterococcal surface protein (esp), hyaluronidase (hyl), and collagen-binding adhesin (acm). RESULTS: All the VRE isolates exhibited multidrug resistance, with the rates of resistance to ampicillin, erythromycin, and ciprofloxacin reaching high levels. The isolates were least resistant to chloramphenicol and nitrofurantoin, but all of them were susceptible to linezolid. 46.6%, 20.8%, and 86.6% of the E.faecium isolates carried the esp, hyl, and acm genes, respectively. CONCLUSION: There is a significant difference between the prevalence of esp and hyl genes in the VRE and VSE isolates. In the VRE isolates, the high prevalence of multidrug resistance were found and the difference in the prevalence of esp among various sources was significant. The findings reflected a relationship between the prevalence of esp and hyl and resistance to certain antibiotics.

Nanoemulsion of atovaquone as a promising approach for treatment of acute and chronic toxoplasmosis.

Treatment of toxoplasmosis is necessary in congenital form and immunocompromised patients. Atovaquone is a powerful suppressor of protozoan parasites with a broad-spectrum activity, but an extremely low water solubility and bioavailability. In this study, nanoemulsion of this drug was prepared with grape seed oil using spontaneous emulsification method to increase bioavailability and efficacy of atovaquone for treatment of toxoplasmosis. In vitro activity of atovaquone nanoemulsion against T. gondii, RH and Tehran strains, was assessed in HeLa cell culture. For in vivo assessment, BALB/c mice were infected with RH and Tehran strains and then treated with nanoemulsion of atovaquone, compared to that treated with free atovaquone. Concentration of atovaquone nanoemulsion showed in vitro anti-parasitic effects in both strains of T. gondii. Furthermore, oral administration of atovaquone nanoemulsion increased oral bioavailability, tissue distribution and mice survival time and reduced parasitemia and number and size of the brain cysts. Decrease of cyst numbers was verified by down regulation of BAG1 using real-time polymerase chain reaction (real-time PCR) assay. Effective therapeutic activity of atovaquone at a reduced dose is the major achievement of this study.

Prevalence of virulence genes and their association with biofilm formation in VRE faecium isolates from Ahvaz, Iran.

INTRODUCTION: Vancomycin-resistant Enterococcus faecium (VREfm) is a common cause of nosocomial infections. Biofilm formation is an important factor in recurrence of infections, facilitating transfer of genetic elements, leading to treatment failures. The aim of this study was to investigate the virulence genes in biofilm producing isolates and to determine possible association between biofilm formation and the presence of these genes; also to determine association between antibiotic susceptibility patterns of VREfm isolates and their biofilm formation ability. METHODOLOGY: A total of 57 isolates of VREfm were recovered from different sources of hospitals under Ahvaz University, Iran. The isolates were examined by conventional microbiological methods and molecular test using PCR. The antibiotic susceptibility patterns of the isolates were determined by disk-diffusion and E-test. The biofilm formation ability of the isolates was investigated by Modified Congo red agar and microtiter plate techniques. The presence of virulence genes was examined using Multiplex-PCR method. RESULTS: Out of 57 VREfm isolates, 63.15% of isolates were biofilm producers. The frequency of biofilm producing isolates from clinical specimens, colonized patients and environmental sources were 78.26%, 60%, and 42.85%, respectively. The prevalence of acm, esp and hyl genes among biofilm producing isolates was 86.10%, 55.56% and 52.77%, respectively. There was statistically significant association between esp gene and biofilm formation among isolates from the clinical specimens. CONCLUSION: Clinical isolates producing biofilms showed a positive association with the presence of the esp. Our study further suggests that the link between virulence genes and biofilms is affected by the environmental context.