Lipids productivity of cyanobacterium Anabaena vaginicola in an internally illuminated photobioreactor using LED bar lights

Concerns over environmental issues exists and desire to decrease of their extent, have directed efforts toward green energy production. Growth behavior of Anabaena vaginicola was determined in a photobioreator which illuminated internally (IIPBR) using LED bar light. Excessive heat generated in the IIPBR was taken care of by applying a novel air-cooled system. Further note in experimentation was to find favorable cultivation conditions in the IIPBR for A. vaginicola growth and its lipids production capacity. The following results are expressed: 80 µmol photons m-2 s-1 as light intensity, 0.5 g/l as NaNO3, and 120 ml/min as CO2 amount being expressed in terms of aeration rate. The findings were interpreted in terms of a two-component system where the genes encoded to the relevant proteins are present in cyanobacteria and their expressiveness depends on environmental stress. By determining growth rate constant as 0.11 d-1, the productivity in terms of biomass formation was calculated as 202.6 mg L-1 d-1. While rate of lipids production by the test cyanobacterium is 15.65 mg L-1 d-1. Based on total energy used for IIPBR performance, biomass productivity per unit power input equals to 0.74 g W-1 d-1 and this is in favorable position compared with other photobioreactors.

Electrochemical-based processes for produced water and oily wastewater treatment: A review

The greatest volume of by-products produced in oil and gas recovery operations is referred to as produced water and increasing environmental concerns and strict legislations on discharging it into the environment cause to more attention for focusing on degradation methods for treatment of produced water especially electrochemical technologies. This article provides an overview of electrochemical technologies for treating oily wastewater and produced water, including: electro-coagulation, electro-Fenton, electrochemical oxidation and electrochemical membrane reactor as a single stage and combination of these technologies as multi-stage treatment process. Many researchers have carried out experiments to examine the impact of various factors such as material (i.e, electrode material) and operational conditions (i.e., potential, current density, pH, electrode distance, and other factors) for organic elimination to obtain the high efficiency. Results of each method are reviewed and discussed according to these studies, comprehensively. Furthermore, several challenges need to be overcome and perspectives for future study are proposed for each method.

Comparison of high-concentration azo dye removal by long HRT in MSBRs' bioaugmented with GAC and sponge media

The present study assessed the performance and fouling of adding granular activated carbon (GAC) and sponge (BioCube), as two different media, to a membrane sequencing batch reactor (MSBR) system in wastewater treatment containing Acid Red 18 (AR 18). Anaerobic phase, aerobic phase, and hydraulic retention times (HRTs) of 24 h, 12 h, and 72 h were considered for 500 mg/L AR 18 removal at a sludge retention time (SRT) of 20 days by separately adding up to 35% BioCube volume and 8 g/L GAC to the reactors. Based on the kinetic study, 63 mg/L (87% removal) and 115 mg/L (77% removal) remaining dye were reported in the GAC and BioCube membrane sequencing batch reactors (GAC-MSBR and BioCube-MSBR), respectively. A gradual oxidation-reduction potential decline toward -416 mV confirmed better dye removal in GAC-MSBR than BioCube-MSBR, observing a sudden drop to -354 mV. The morphology can explain better biological treatment in GAC-MSBR in addition to the adsorption process. Soluble microbial products (SMPs) of 126.92 mg/L and 395.18 mg/L were obtained for GAC-MSBR and BioCube-MSBR, respectively. Chemical oxygen demand (COD) and SMP indicated that the GAC-MSBR water quality is better than that of the other reactor.

Influence of salinity on heavy metal and oil removal from hypersaline oilfield-produced water by electrocoagulation: mechanistic insights

The focus of the present study was to explore how and to what extent ultrahigh salinity affects the adsorption of cadmium and hydrocarbon pollutants onto aluminum hydroxide adsorbents formed in an electrocoagulation process. The changes in the nature and structure of the electro-generated aluminum particles and the possible removal mechanisms due to high salt content were investigated by using FE-SEM/EDS, FTIR, BET, and XRD analyses. The pseudo-second order and Freundlich models proved to fit the data for cadmium adsorption onto the aluminum hydroxides best. It was demonstrated that the adsorption capacities were significantly affected by the high salinity. With the rise of the salinity from 2 to 170 g/L, the cadmium and COD removal yields dropped from 81 to 60% and from 90 to 72%. The increase of the oil content led to the enhanced cadmium adsorption capacity due to surface complexation and ion exchange mechanisms. It was proved that Lagergren pseudo-first-order kinetic model could justify COD abatement trends. FTIR spectra depicted that the negative impact of high salinities on the adsorption was due to causing the formation of less stable adsorbents. According to BET analysis, the occurrence of much wider pore size distribution and smaller specific surface area in high salinity case was the main reason for the decreased adsorption capacity. Based on XRD analysis, the higher crystallinity of the produced aluminum hydroxide particles and their consequential smaller surface areas resulted in the lower adsorption capacity in the hypersaline environment. It was concluded that adsorption via inner-sphere and outer-sphere complexation and sweep flocculation were the possible removal mechanisms. Total treatment cost of 8.75 and 3.49 €/m3 were estimated for low and ultrahigh salinity conditions.

Photocatalytic degradation of 2,4-DNT in simulated wastewater by magnetic CoFe2O4/SiO2/TiO2 nanoparticles

Discharge of 2,4-dinitrotoluene (2,4-DNT) into the environment leads to a serious soil and water sources pollution problem, due to toxicity and possible carcinogenicity of this toxic substance. In this work, the photocatalytic degradation of 2,4-DNT was investigated using CoFe₂O₄/SiO₂/TiO₂ nanoparticles. The catalyst features were characterized by using XRD, TEM, EDX, UV-vis DRS, FTIR, and VSM techniques. The influence of different experimental factors on degradation efficiency including pH value, catalyst dosages, and initiate concentration of 2,4-DNT were investigated. Mineralization of the model pollutant was determined using TOC analysis under optimum conditions. A possible mechanism, process kinetic and reusability of magnetic photocatalyst were also performed. In optimum experimental conditions (pH=3, photocatalyst dosage=0.75 g/L, 2,4-DNT=0.025 g/L), degradation efficiency achieved 88.5% within 180-min reaction time with TOC removal of 55.6%. Dominate oxidizing radicals during the degradation of 2,4-DNT by CoFe₂O₄/SiO₂/TiO₂ were hydroxyl radicals. The photocatalytic degradation of 2,4-DNT followed first-order rate kinetics. After three successive use cycles, the degradation efficiency was reduced by 64%. Our results revealed that the synthesized CoFe₂O₄/SiO₂/TiO₂ photocatalyst was a good choice for degradation of 2,4-DNT, due to proper potential reusability and catalytic activity.

The effect of temperature and styrene concentration on biogas production and degradation characteristics during anaerobic removal of styrene from wastewater

In the current study, styrene was removed anaerobically from wastewaters at temperatures of 35 ℃, 25 ℃, and 15 ℃ and concentration range of 20-150 ppm in the presence of ethanol as a co-substrate and co-solvent. Maximum styrene removal of 93% was achieved at 35 ℃. The volatilization of styrene was negligible at about 2% at all experimented temperatures. The average special methane yield (SMY) at 35 ℃ was 4.14- and 225-times higher than that of at T = 25 ℃ and T = 15 ℃, respectively, but no methane was produced in the absence of ethanol. The proteins content of the soluble microbial product (SMP) and extracellular polymeric substance (EPS) was much higher than the carbohydrate content. At styrene concentration > 80 ppm, SMY, SMP, and EPS dropped sharply. The results confirmed the well performance of anaerobic microorganisms in removing styrene from wastewater and biogas production at mesophilic condition.

Date fruit processing waste and approaches to its valorization: A review

In the Middle East and North Africa, dates are a traditional and economically valuable crop, playing an essential role in people's daily diets. Date fruit production and related processing industry generate a large quantity of waste; for illustration, the date juicing industry produces roughly 17-28% Date press cake (DPC), which is mainly discarded in open lands and drains. Considering the generation volume and the nutrient content of DPC, this organic by-product stream can be valorized through the production of a wide range of products with a great market appeal, such as volatile fatty acids, activated carbon, organic acids, etc. To provide an insight into the feasibility of the application DPC as a green precursor for various chemical and biological processes, the chemical and nutritional composition of dates and DPC, an overview of the date processing industries, and common practices conducted for DPC valorization addressed and thoroughly discussed, in this review.

Molecular typing and prevalence of extended-spectrum β-lactamase genes in diarrhoeagenic Escherichia coli strains isolated from foods and humans in Mashhad, Iran

AIMS

Present study was aimed to determine ESBL-encoding genes distribution in Diarrhoeagenic Escherichia coli (DEC) isolated from animal-source food products and human clinical samples in Mashhad, Iran. The strains were also further studied to analyse genotypic diversity and find genetic relationships between them.

METHODS AND RESULTS

The number of 85 DEC strains including 52 and 33 strains isolated from 300 food and 520 human stool samples, respectively. Randomly amplified polymorphic DNA (RAPD), and repetitive extragenic palindromic-PCR (rep-PCR) typing methods were used to track their genetic relationships. The ESBL-encoding genes prevalence was approximately 70% in both groups of isolates. The bla_TEM , bla_CTX-M and bla_SHV were prevalent in 67·1, 20 and 10·6% of isolates, respectively. The ESBL-positives showed significantly higher resistance rates to gentamicin, co-trimoxazole, tetracycline, aztreonam and chloramphenicol (P < 0·05). Fingerprinting patterns-based dendrograms divided DEC strains into separate clusters irrespective of their sources and pathotypes. In typing field, rep-PCR provided more discriminatory power (Simpson's index of diversity (SID) = 0·925) than RAPD (SID = 0·812).

CONCLUSION

Molecular similarity between certain animal-sourced food products and clinical sample strains supported food-borne transmission routes for genotypic elements such as ESBL-encoding genes.

SIGNIFICANCE AND IMPACT OF THE STUDY

Findings emphasize the importance of resistance issues, the need to improve treatment guidelines and routine surveillance of hygienic measures during food processing.

Prediction of Cognitive Status and 5-Year Survival Rate for Elderly with Cardiovascular Diseases: A Canadian Study of Health and Aging Secondary Data Analysis

BACKGROUND

Given the important association between cardiovascular disease and cognitive decline, and their significant implications on frailty status, the contribution of neurocognitive frailty measure helping with the assessment of patient outcomes is dearly needed.

OBJECTIVES

The present study examines the prognostic value of the Neurocognitive Frailty Index (NFI) in the elderly with cardiovascular disease.

DESIGN

Secondary analysis of the Canadian Study of Health and Aging (CSHA) dataset was used for prediction of 5-year cognitive changes.

SETTING

Community and institutional sample.

PARTICIPANTS

Canadians aged 65 and over [Mean age: 80.4 years (SD=6.9; Range of 66-100)].

MEASUREMENT

Neurocognitive Frailty Index (NFI) and Modified Mini-Mental State (3MS) scores for cognitive functioning of all subjects at follow-up and mortality rate were measured.

RESULTS

The NFI mean score was 9.63 (SD = 6.04) and ranged from 0 to 33. This study demonstrated that the NFI was significantly associated with cognitive changes for subjects with heart disease and this correlation was a stronger predictor than age.

CONCLUSION

The clinical relevance of this study is that our result supports the prognostic utility of the NFI tool in treatment planning for those with modifiable cardiovascular disease risk factors in the development of dementia.

Quantifying the organic content of saline wastewaters: Is chemical oxygen demand always an achievable parameter?

The study presented in this paper takes a comprehensive approach to the measurement of the COD of saline industrial wastewaters taking into account both their widely varying salinity levels and the substantial interference of chloride with the conventional method of COD measurement. To this end, three approaches for combating the chloride interference associated with the measurement of COD using the conventional method were considered. The dilution of saline samples prior to analysis yielded reasonably accurate COD results as long as the COD after dilution was 40 mg L^-1 or above. In the second approach, the previously reported modifications of the standard method were stretched to their practical limits (increasing HgSO₄ to 130 g L^-1 and decreasing K₂Cr₂O₇ to 1.022 g L^-1) accompanied by prior addition of HgSO₄:Cl^- at a ratio of 20:1 combined with chloride interference error estimation. This brought about an increase in chloride interference threshold of the standard method to 42.5 g L^-1, which is considerably higher than previous reports. Since some raw or treated saline industrial wastewaters have a combination of chloride and COD concentration which makes the first two approaches inapplicable, the approach of chloride removal from the sample via a modification of DIN 38409-H41-2 and subsequent measurement of COD using a slight variation of the closed reflux standard method was also considered. Fairly accurate COD determinations for samples with chloride concentrations up to 148.6 and 182 g L^-1 for COD contents of 50 and 900 mg L^-1, respectively were achieved. However, excessive precipitation of the desalination reaction products made the method inapplicable to samples with chloride concentrations above 182 g L^-1.

An ultrasonic method for the synthesis, control and optimization of CdS/TiO2 core–shell nanocomposites

In this study, an ultrasonic method was utilized in combination with microemulsion to synthesize CdS/TiO₂ core–shell nanoparticles and control their particle size and ultimately optimize the influential parameters. Moreover, response surface methodology (RSM) was used to optimize the thickness of the shell. Herein, four parameters, i.e. temperature (67–79 °C), synthesis retention time (45–105 min), TiO₂ : CdS ratio (1.5–7.5) and the power of ultrasound waves (37–53 watt), were optimized to synthesize nanoparticles with an average size of up to 10 nm. A correlation equation was introduced for the size range of 10–90 nm, which was then proven to have excellent predictions. To verify the proposed model, two different sets of combinations were selected to synthesize 10 nm composites, and consequently, nanocomposites with the sizes of 10.4 and 10.9 nm were successfully synthesized. The power of ultrasound waves and retention time had the most influence on the size of the particles. Further experiments proved that the optical absorption spectrum of the composite particles was extended to the visible region. Furthermore, the formation of CdS/TiO₂ core–shell nanocomposites was confirmed by different characterization techniques including XRD, TEM, EDAX, UV-vis, FTIR and DLS.

In this study, an ultrasonic method was utilized in combination with microemulsion to synthesize CdS/TiO₂ core–shell nanoparticles and control their particle size and ultimately optimize the influential parameters.

Combination of novel coalescing oil water separator and electrocoagulation technique for treatment of petroleum compound contaminated groundwater

In the present study a combination of a novel coalescing oil water separator (COWS) and electrocoagulation (EC) technique was used for treatment of petroleum product contaminated groundwater. In the first phase, COWS was used as the primary treatment. Two different types of coalescing media and two levels of flow rates were examined in order to find the optimum conditions. The effluent of COWS was collected in optimum conditions and was treated using an EC process in the second phase of the research. In this phase, preliminary experiments were conducted in order to investigate the effect of EC reaction time and sedimentation time on chemical oxygen demand (COD) removal efficiency. Best conditions for EC reaction time and sedimentation time were obtained to be 5 min and 30 min, respectively. Response surface methodology was applied to evaluate the effect of initial pH, current density and aeration rate on settling velocity (V_s) and effluent COD. The optimum conditions, for achieving maximum values of V_s as well as the values of effluent COD, in the range of results were obtained at conditions of 7, 34 mA·cm^-2 and 1.5 L·min^-1 for initial pH, current density and aeration rate, respectively.

Sequential anaerobic-aerobic biological treatment of colored wastewaters: case study of a textile dyeing factory wastewater

In the present study the feasibility of the use of a bacterial batch sequential anaerobic-aerobic process, in which activated sludge was used in both parts of the process, for pretreatment of wastewater generated by a textile dyeing factory has been considered. Activated sludge used in the process was obtained from a municipal wastewater treatment plant and adapted to real dyeing wastewater using either an anaerobic-only or an anaerobic-aerobic process over a period of 90 days. The use of activated sludge adapted using the anaerobic-aerobic process resulted in a higher overall decolorization efficiency compared to that achieved with activated sludge adapted using the anaerobic-only cycles. Anaerobic and aerobic periods of around 34 and 22 hours respectively resulted in an effluent with chemical oxygen demand (COD) and color content which met the standards for discharge into the centralized wastewater treatment plant of the industrial estate in which the dyeing factory was situated. Neutralization of the real dyeing wastewater and addition of carbon source to it, both of which results in significant increase in the cost of the bacterial treatment process, was not found to be necessary to achieve the required discharge standards.

Optimization of photocatalytic degradation of real textile dye house wastewater by response surface methodology

This study evaluates the advanced oxidation process for decolorization of real textile dyeing wastewater containing azo and disperse dye by TiO₂ and UV radiation. Among effective parameters on the photocatalytic process, effects of three operational parameters (TiO₂ concentration, initial pH and aeration flow rate) were examined with response surface methodology. The F-value (136.75) and p-value <0.0001 imply that the model is significant. The 'Pred R-Squared' of 0.95 is in reasonable agreement with the 'Adj R-Squared' of 0.98, which confirms the adaptability of this model. From the quadratic models developed for degradation and subsequent analysis of variance (ANOVA) test using Design Expert software, the concentration of catalyst was found to be the most influential factor, while all the other factors were also significant. To achieve maximum dye removal, optimum conditions were found at TiO₂ concentration of 3 g L^-1, initial pH of 7 and aeration flow rate of 1.50 L min^-1. Under the conditions stated, the percentages of dye and chemical oxygen demand removal were 98.50% and 91.50%, respectively. Furthermore, the mineralization test showed that total organic compounds removal was 91.50% during optimum conditions.

Transitions in cognitive status in relation to frailty in older adults: a comparison of three frailty measures

OBJECTIVES

Cognitive decline is related to frailty. Frailty can be operationalized in different ways, which have an unknown impact on the estimation of risk. Here, we compared 3 frailty measures in relation to cognitive changes and mortality in the Canadian Study of Health and Aging (CSHA).

DESIGN

Prospective population-based study, with 5 year follow up.

PARTICIPANTS/SETTING

2,305 subjects aged 70+ years.

METHODS

For each participant, cognitive status was measured by the errors in the Modified Mini-Mental State Examination (3MS) score. Three frailty measures were used: a Frailty Index based on the Comprehensive Geriatric Assessment (FI-CGA) evaluated from 47 potential deficits, a Clinical Frailty Score and the Fried frailty phenotype. Multivariate Poisson regression and multivariate logistic regression were used to examine the association between baseline cognitive errors and frailty and death, respectively, while controlling for possible confounders (age, sex, education, and baseline cognitive status).

RESULTS

Changes in cognitive status were strongly associated with baseline cognition and frailty, however defined. In multivariate models adjusted for age, sex and education, each frailty measure was associated with cognitive decline and with mortality. The frailest people (from the highest FI-CGA tertile) rarely showed cognitive improvement or stabilization (1.5%, 95% CI=0.002%-2.8%) compared with non-frail people (from the lowest tertile of the FI-CGA), of whom 27.8% (95% CI=24.5%-31.1%) did not deteriorate.

CONCLUSIONS

Frail elderly people have an increased risk of cognitive decline. All frailty measures allowed quantification of individual vulnerability and predict both cognitive changes and mortality.

Kinetics of styrene biodegradation in synthetic wastewaters using an industrial activated sludge

Kinetics of styrene biodegradation in synthetic wastewaters, containing either styrene or styrene together with ethanol, by an industrial activated sludge obtained from the wastewater treatment unit of a petrochemical complex was studied. The kinetic data could be fitted using the Haldane kinetic model. This model was previously used to predict kinetic data for biodegradation of styrene by pure or mixed microbial cultures isolated from biofilters, but the values of the model parameters reported in these studies was substantially different from that obtained for the industrial activated sludge. The presence of ethanol did not affect the kinetics of styrene biodegradation by the industrial activated sludge; however, it increased the rates of styrene biodegradation due to the resulting higher microbial growth rates. Styrene concentration was found to affect the specific growth rate in a manner similar to its effect on the styrene degradation rate. No lag phase was observed in styrene biodegradation by industrial activated sludge for styrene concentrations up to 100mg/L. Lag phase was observed for municipal activated sludge even at 50mg/L styrene concentration but the rate of styrene biodegradation after the lag phase was similar to that achieved by the industrial activated sludge.

Long-term operation of submerged membrane bioreactor (MBR) for the treatment of synthetic wastewater containing styrene as volatile organic compound (VOC): Effect of hydraulic retention time (HRT)

In this study, the membrane bioreactor (MBR) was utilized to remove styrene from a synthetic wastewater having a chemical oxygen demand (COD) and styrene concentration of 1500 mg/L and 50 mg/L, respectively. At two hydraulic retention times (HRTs) of 24 h and 18 h, the MBR was operated for a period in excess of 100 days. The HRT effects were studied and it was found out that the removal efficiency of COD and styrene for both HRTs was consistently higher than 99%. Unlike conventional activated sludge processes (CASPs), no styrene was detected in the exhaust air, which meant that biodegradation was the major styrene removal mechanism at both HRTs. The transmembrane pressure (TMP) profile during the operation of the MBR showed a fairly low and constant TMP up to day 70, after which, the TMP showed a dramatic rise, as a result of the occurrence of severe membrane fouling. It was thought that an increase in styrene loading rate, when HRT was reduced to 18 h, resulted in the release of extracellular polymeric substance (EPS) from the bacterial cells, which in turn was responsible for the rise in soluble microbial product (SMP) and sludge deflocculation. The severe fouling observed during operation of MBR at HRT of 18 h was attributed to the rise in SMP concentrations and decrease in mean floc size and increase in the proportion of small particles in the activated sludge.

Comparison of the prognostic importance of diagnosed diabetes, co-morbidity and frailty in older people

AIMS

To compare the relative prognostic importance in older people of diagnosed diabetes, the number and severity of co-morbidities and frailty.

METHODS

Two thousand three hundred and five people aged > or = 70 years comprised the clinical examination cohort of the Canadian Study of Health and Aging. Frailty was defined as a score of > or = 5 on a 7-point Clinical Frailty Scale. The cohort was followed for 5 years.

RESULTS

Diabetes was more likely to be associated with medium-term mortality (adjusted hazard ratio (HR) 1.42; 95% confidence interval (CI) 1.20-1.69) than co-morbidity (HR 1.03; 95% CI 1.01-1.05). Frailty most strongly predicted death (HR 2.72; 95% CI 2.34-3.16). Frail older adults were 2.62 times (95% CI 1.36-5.06) more likely to have a complication of diabetes, independent of age, sex and number of years living with diabetes. People with diabetes were younger than those without (81.3 vs. 83.3 years) but a similar proportion were frail (42.2 vs.43.4%). The median life expectancy for frail older adults with diabetes was 23 months (95% CI 18-28 months).

CONCLUSIONS

In this cohort, the risk of mortality in older people was defined more precisely by a clinical measure of frailty than by diabetes or burden of co-morbidity. Those with diagnosed diabetes were younger than those without but had the same frailty status; diabetes can therefore be considered to increase 'biological age' by 2 years in those aged over 70 years. The limited life expectancy of frail older people with diabetes highlights the importance of recognizing frailty and supports the individualization of care in older people with diabetes.

Comparison of two frailty measures in the Conselice Study of Brain Ageing

OBJECTIVES

Uncertainty about the definition of frailty is reflected by the development of many ways to identify frail people. We aimed to compare the validity of two frailty measures in participants of the Conselice Study of Brain Aging.

DESIGN

Prospective population-based study with 4 year follow up.

PARTICIPANTS/SETTING

1,016 subjects aged 65 and over in a rural Italian population.

METHODS

For each participant, a Frailty Index (FI) and a Conselice Study of Brain Aging Score (CSBAS) were determined. The FI was created from 43 deficits according to a standardized methodology; 7 variables derived from a previously validated Easy Prognostic Score comprised the CSBAS.

RESULTS

The FI had characteristic properties described in other population samples, with a gamma distribution, a 99% limit of about 0.64 and higher values in women than men. CSBAS and FI were strongly correlated with each other (r = 0.72) and both correlated with age (r = 0.32, r = 0.27, respectively). Each was independently predictive of death in a multivariate model, with greater specificity and sensitivity than age alone.

CONCLUSIONS

Frailty can be measured by different tools and facilitates a more direct quantification of individual vulnerability than chronological age alone. Though the Frailty Index and the Conselice Study of Brain Aging Score are underpinned by different rationales, clinical utility will continue to motivate their development.

Incidence of aflatoxins in Iran pistachio nuts

Aflatoxins (AF) are highly toxic and carcinogenic secondary fungal metabolites and have been detected in various food commodities including pistachio nuts. Pistachio nuts were produced in Iran during March 2002-February 2003 analyzed for aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1) and aflatoxin G2 (AFG2) using immunoaffinity column and quantitated by HPLC and/or TLC-scanner. In this regard, 3356 pistachio nut samples were collected. After dividing samples to sub-samples, 10,068 AF analyses were done. Among 10,068 samples analyzed, AFB1 was detected in 3699 samples (36.7% of the total) with the mean and median of 5.9 (+/-41.7) ng/g and 0.1 ng/g, respectively. Total AF (AFT) was detected in 2852 samples (28.3% of the total) with the mean and median of 7.3 (+/-53.2)ng/g and 0.4 ng/g, respectively. AFB1 level in 1191 samples (11.8%) was above the maximum tolerated level (MTL) of AFB1 in pistachio nut in Iran (5 ng/g). Regarding AFT, the mean contamination level (7.3 ng/g) was lower than MTL of AFT in pistachio nut in Iran as well as lower than the proposed draft maximum level of Codex Committee on Food Additives and Contaminants for AFT (15 ng/g), and only 7.5% of samples had levels above the MTL.

One-year efficacy of expanded polytetrafluoroethylene vascular graft in eighty-three hemodialysis patients

INTRODUCTION

Our aim was to evaluate the patency and efficacy of expanded Polytetrafluoroethylene (ePTFE) vascular graft in hemodialysis patients.

MATERIALS AND METHODS

In a prospective study from January 1999 to January 2001 at Sina hospital 41 patients underwent implantation of 6-mm vascular grafts and 42 underwent implantation of 8-mm grafts in order to make vascular assess for hemodialysis. They were followed up to 12 months, observing the complications.

RESULTS

Mean patients' age was 52.2 years. Thirty-seven of them were females and 46 were males. Over a 12 months period of follow-up, 12 cases of graft infection (14.5%), 21 cases of thrombosis (25.3%), 7 cases with both complications (8.4%), and 1 case of pseudoaneurism (1.2%) were observed. One-year patency rate was 34.9%. Diabetes was the only factor associated with lower patency rate (27% versus 57%, p<0.05).

CONCLUSION

ePTFE vascular graft seems to be an appropriate substitute for arteriovenous fistula as a vascular assess in hemodialysis patients. Educating patients and good care can decrease the rate of infection, thrombosis, and other complications, resulting in a better patency and lower morbidity rate.

[Palindromic rheumatism. Immunologic survey and study of development in 43 cases]

43 patients (18 females, 25 males) presenting palindromic rheumatism were given follow-up examinations after a mean lapse of 14.75 years. 16 subjects still presented palindromic rheumatism and of these six showed complete remission. 27 patients had developed chronic inflammatory rheumatism after seven years (mean value) of palindromic rheumatism, but resolution of PR was seen in four cases. Male predominance was more marked in the palindromic subgroup (PAL) but was also seen in the subgroup of subjects who had developed PR (PAL-PR). Laboratory tests demonstrated a constant homogeneous increase in immunoglobulins (notable IgAs) and in the T4/T8 ratio in the PAL and PAL-PR subgroups. Rheumatoid serodiagnostic tests were positive significantly more frequently in the PAL-PR subgroup, which also comprised a high proportion of cases of erosive arthritis. Overall the frequency of HLA-DR 4 antigen did not increase in the subjects studied. Subjects in the PAL subgroup (cf. PAL-PR subgroup) were characterized by a twofold increase in frequency of DR 5 antigen, with a relative risk of 3.5 to 4.5, a significant increase in B35 and B5 and a clear decrease in B12.

[Estimate of the prevalence of rheumatoid arthritis based on a rheumatology study in the district of Angers]

The prevalence of rheumatoid arthritis is generally estimated to be 1 per cent, despite the marked differences between the various results published according to the survey techniques and the epidemiological criteria employed. The present survey consisted of patients from the target population (the 248,009 inhabitants of Angers over the age of 15 years), who had been examined by one of the hospital or private rheumatologists working in Angers between 1960 and 1984 and who were considered to be suffering from inflammatory rheumatism. The cases of rheumatoid arthritis included in this survey were still alive and were living in Angers between January 1 and June 30 1984 and corresponded to at least two of the New York criteria. The prevalence determined according to this technique was 0.17 per cent for two criteria and 0.11 per cent for three criteria. After discussing the bias and the particular conditions of the study, it appears that these particularly low levels are essentially related to: a recruitment bias due to the limitation of the survey to patients seen by rheumatologists, to the choice of New York criteria and more especially of 3 criteria which increases the specificity of the survey at the expense of the sensitivity, to the long observation (mean of 10.4 years) which contributed to a reduction in the number of false positives. The validity of this study is supported by the comparison with the study by O'Sullivan et al. also based 2 New York criteria with a follow-up of 3 to 5 years, which concluded on a prevalence of 0.24 per cent compared with 0.17 per cent in Angers.(ABSTRACT TRUNCATED AT 250 WORDS)

[Correlation between osteoporosis and discarthrosis. Comparative frequency of spinal osteophytosis and thickness of intervertebral disk in 50 patients with osteoporosis confirmed by bone biopsy and in 50 controls. Study of lordosis in 50 osteoporotic patients]

Comparative radiological study of the spine in 50 osteoporotic subjects selected on double criteria, radiological and histological, and 50 control subjects of the same age and same sex, confirmed the lesser frequency and the mildness of the osteophyte formation, and the disk degeneration in osteoporotic subjects. The vertebral radiological index, which measures both the number and importance of the vertebral body surface concavity and vertebral collapse, and has no significant correlation with age. A study of the degree of lordosis and of the index of bending of the trunk was carried out in 50 osteoporotic patients. Only one third of them had lumbar hyperlordosis. Owing to its inconstancy, lumbar hyperlordosis cannot be considered as responsible for the mildness of the osteophyte formation in osteoporotic patients. It seems reasonable to admit that the mildness of the osteophyte formation and of the osteoporosis are linked together and are probably the result of a reduced capacity of bone formation.