Rapid one-step separation and purification of recombinant phenylalanine dehydrogenase in aqueous two-phase systems

Background: Phenylalanine dehydrogenase (PheDH; EC 1.4.1.20) is a NAD +-dependent enzyme that performs the reversible oxidative deamination of L-phenylalanine to phenylpyruvate. It plays an important role in detection and screening of phenylketonuria (PKU) diseases and production of chiral intermediates as well. The main goal of this study was to find a simple and rapid alternative method for purifying PheDH. Methods: The purification of recombinant Bacillus sphaericus PheDH was investigated in polyethylene glycol (PEG) and ammonium sulfate aqueous two-phase systems (ATPS). The influences of system parameters including PEG molecular weight and concentration, pH and (NH4)2SO4 concentration on enzyme partitioning were also studied. The purity of enzyme was analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Results: A single extraction process was developed for separation and purification of recombinant PheDH from E. coli BL21 (DE3). The optimized conditions for partitioning and purification of PheDH were 9% (w/w) PEG-6,000 and 16% (w/w) (NH4)2SO4 at pH 8.0. The partition coefficient, recovery, yield, purification factor and specific activity values were achieved 58.7, 135%, 94.42%, 491.93 and 9828.88 U/mg, respectively. Also, the Km values for L-phenylalanine and NAD+ in oxidative deamination were 0.21 and 0.13 mM, respectively. Conclusion: The data presented in this paper demonstrated the potential of ATPS as a versatile and scaleable process for downstream processing of recombinant PheDH

Seroprevalence of toxocariasis in children aged 1-9 years in western Islamic Republic of Iran, 2003

We determined the seroprevalence of Toxocara canis infection in 544 children under 10 years randomly selected from urban and rural areas of Hamadan, An enzyme-linked immunosorbent assay was used for detection of antibodies to T. canis excretion - secretion antigens. Using a questionnaire, epidemiological factors associated with infection were examined, including age, sex, residence. Antibodies to T. canis were detected in 29 children (5.3%) and 19 children (3.5%) were categorized as borderline positive; thus together this gave a prevalence of toxocariasis of 8.8%. No significant differences were found in terms of sex, age and residence

Clinical manifestations of Giardiasis in Iran

Context: Giardiasis has multiple clinical manifestations and its prevalence is relatively high in the Hamadan province of Iran. Aims: This study was conducted to determine the most frequent clinical signs and symptoms of Giardiasis in the Hamadan province of Iran in 2006. Setting and Design: This was a descriptive cross sectional study. Methods and Material: Sixty four patients infected with Giardia were recruited. Antiglidin anti-body and TTG tests were done to rule out celiac disease. Statistical analysis used: The data was entered into a computer and chi-square test was used for statistical analysis. Results: Of a total of 64 cases, 26 were females. Giardiasis was most common in cases aged 16-20 years old (20.3%), in males (59.4%) and in patients with the educational status of primary school (31.25%). The most frequent symptom was abdominal pain (42.1%). Conclusion: We found that the clinical manifestations of Giardiasis are similar to that of other gastrointestinal diseases such as celiac. So Giardiasis should be considered as the most probable diagnosis in patients with gastrointestinal problems

Molecular variation in Leishmania parasites from sandflies species of a zoonotic cutaneous leishmaniasis in northeast of Iran

Background & objectives: In the well-known zoonotic cutaneous leishmaniasis (ZCL) focus in Turkmen Sahara, border of Iran and Turkmenistan, ZCL has increased among humans in the past five years. The present study was undertaken to incriminate vectors of ZCL in the region, and to find molecular variation in Leishmania parasites. Methods: The sandflies were sampled using CDC light-traps and sticky papers. All the sandflies were identified using morphological characters of the head and abdominal terminalia. DNA was extracted from the dissected thorax and attached anterior abdomen of individual female sandfly. Leishmania detection and identification of sandflies were performed using PCR, digestion of BsuRI restriction enzyme and sequencing of ITS-rDNA gene and also by semi-nested PCR to amplify minicircle kinetoplast (k) DNA of Leishmania. Results: Leishmania infections were detected in 26 out of 206 female sandflies. Of the infected sandflies, 18 were Phlebotomus papatasi while eight were P. caucasicus/P. mongolensis. Two infections of L. turnica were detected, one in P. papatasi and other in P. caucasicus/P. mongolensis and the rest of the sandflies were found infected with L. major. Conclusion: Our finding showed that L. major had low diversity with only one common haplotype (GenBank Access No. EF413075). The novel haplotypes were discovered in L. major (GenBank Access No. KF152937) and in L. turanica (GenBank Access No. EF413079) in low frequency. These Leishmania parasites are circulating to maintain infections in the P. papatasi and P. caucasicus/P. mongolensis in Turkmen Sahara

Anthropometric indices in individuals infected with ascaris lumbericoids in Iran

Context: Ascaris Lumbericoids infection is more common in children and teenagers and in areas with poor sanitation or crowded living conditions. Largest of all the parasites inhabiting the human intestine it is also the most common of parasitic infections in developing countries. It has been reported to infect about one-fourth of the world population. Chronic ascariasis has been reported to adversely effect the growth rate and anthropometric indices in infected individuals of growing age. Aims: The goal of this research was to evaluate the anthropometric indices in individuals infected with Ascaris in Hamedan province of Iran. Settings and Design: This was a descriptive cross sectional study. Methods and Material: Six hundred fourteen randomly selected individuals who were inhabitants of Hamedan province of Iran were chosen for this study. Stool samples of these individuals were collected and then experimented with Formel-Ether method to determine Ascaris Lumbericoids infection. Height and weight of these individuals were measured and compared with the indices related to NCHS. Demographic information of these individuals was entered into questionnaires and ultimately was analyzed with SPSS software. Results: Out of the total study population, 16.5% of individuals were found to be infected with Ascaris. Out of the individuals infected with Ascaris, 1% were underweight. In the age groups of 6-10, 11-15, 16-20 years, 3.5%, 5.1% and 3.5% were found to be suffering from malnutrition, respectively. Conclusion: Malabsorption in children might result in malnutrition. In this study, few individuals infected with Ascaris had malnutrition, thus Ascaris infection may not be an important cause of malnutrition among children in our area

Association between Endothelial Selectin (E-selectin) gene polymorphisms and E-selectin level with visceral leishmaniais, in an ARMS-PCR based study

Background: In the visceral leishmaniasis (VL), parasites reside in reticuluendothelial system, mainly in macrophages. Endothelial Selectin (E-selectin) might play an important role in leukocyte-endothelium interactions and inflammatory cell recruitment. The aim of this study was determining E-selectin level and its polymorphism in three groups, patients, seropositive and healthy individuals. Methods: Serum soluble E-selectin levels as well as 2 polymorphisms of E-selectin (Ser128Arg and Leu554Phe) were measured in a cohort of patients with documented VL (n=64), a healthy control group (n=74) and a seropositive for VL but without any symptoms (n=81). Circulation concentration of E-selectin levels was measured by ELIS. The amplification refractory mutation system (ARMS)-PCR procedure was used for detecting polymorphisms. Results: The mean of E-selectin levels significantly differed between three groups (P<0.026), and were increased in patients in comparison with other groups. Difference was more considerable between two groups of patients and healthy ones (patients 92.8 ng/ml; healthy individuals 71.9 ng/ml). Polymorphisms were associated with soluble E-selectin levels and altogether explained 14.4%, 7.2%, and 8.7% in patients, seropositive and seronegative healthy individuals, respectively. Distribution of polymorphisms of 128Ser/Arg and 554Leu/Phe among three groups was not different significantly; however, there was a considerable arrangement in distribution of Ser128Arg polymorphism and 128Arg allele in healthy group was more than two fold of patients (55% against 20%). Conclusion: The association between soluble E-selectin levels and visceral leishmaniasis suggests that this molecule might have significant role in the inflammatory process in VL. Moreover, frequency of 128Arg allele in healthy group was higher than patients

Discrimination of Entamoeba spp. in children with dysentery

Aim: The present study was performed in order to differentiate E. histolytica and E. dispar in children from Gorgan city, using a PCR method. Background: Differential detection of two morphologically indistinguishable protozoan parasites Entamoeba histolytica and E. dispar has a great clinical and epidemiological importance because of potential invasive pathogenic E. histolytica and non-invasive parasite E. dispar. Patients and methods: One hundred and five dysentery samples were collected from children hospitalized in Taleghani hospital in Gorgan city. The fecal specimens were examined by light microscopy (10X then 40X) to distinguish Entamoeba complex. A single round PCR amplifying partial small-subunit rRNA gene was performed on positive microscopy samples to differentiate E. histolytica/ E. dispar and E. moshkovskii from each other. Results: Twenty-five specimens (23.8%) were positive for Enramoeba complex in direct microscopic examination. PCR using positive controls indicated E. histolytica and E. dispar in two (2/25, 8%) and three (3/25, 12%) samples, respectively. Conclusion: There is a warrant to performing molecular diagnosis for stool examination at least in hospitalized children in order to prevent incorrect reports from laboratories and consequently mistreating by physicians. © 2014 RIGLD, Research Institute for Gastroenterology and Liver Diseases

Fumonisin B1 contamination of cereals and risk of esophageal cancer in a high risk area in Northeastern Iran

Introduction: Fumonisin B1 (FB1) is a toxic and carcinogenic mycotoxin produced in cereals due to fungal infection. This study was conducted to determine FB1 contamination of rice and corn samples and its relationship with the rate of esophageal cancer (EC) in a high risk area in northeastern Iran. Methods: In total, 66 rice and 66 corn samples were collected from 22 geographical subdivisions of Golestan province of Iran. The levels of FB1 were measured for each subdivision by thin layer and high pressure liquid chromatographies. The mean level of FB1 and the proportions of FB1 contaminated samples were compared between low and high EC-risk areas of the province. Results: The mean of FB1 levels in corn and rice samples were 223.64 and 21.59 μ/g, respectively. FB1 contamination was found in 50% and 40.9% of corn and rice samples, respectively. FB1 level was significantly higher in rice samples obtained from high EC-risk area (43.8 μ/g) than those obtained from low risk area (8.93 μ/g) (p-value=0.01). The proportion of FBI contaminated rice samples was also significantly greater in high (75%) than low (21.4%) EC-risk areas (p-value=0.02). Conclusion: We found high levels of FBI contamination in corn and rice samples from Golestan province of Iran, with a significant positive relationship between FB1 contamination in rice and the risk of EC. Therefore, fumonisin contamination in commonly used staple foods, especially rice, may be considered as a potential risk factor for EC in this high risk region

Gene polymorphism in transforming growth factor-beta codon 10 is associated with susceptibility to Giardiasis

Secretory immunoglobulin A (S-IgA) antibodies have a central role in anti-Giardial defence. It has been demonstrated that transforming growth factor-beta1 (TGF-P1) stimulates B lymphocytes to produce and secrete S-IgA. We sought to determine the association between TGF-β1 polymorphism (T+869C) with susceptibility to Giardiasis. The TGF-β1 genotypes and levels of salivary (S-IgA) were analysed in individuals with Giardiasis (97 symptomatic and 57 asymptomatic) and controls (n = 92). Individuals with symptomatic Giar- diasis had the lowest levels of S-IgA compared to individuals in asymptomatic Giardiasis and control groups (97%, 73% and 43%, <1 g L-1, respectively, P = 0.002). The frequency of allele C and CC genotypes of TGF-β1 polymorphism was significantly higher among symptomatic patients than asymptomatic and control groups. Logistic regression analysis demonstrated that the individuals homozygous for allele C of TGF-β1 had a significantly higher risk for symptomatic Giardiasis with odds ratio of 2.76 (95% CI: 3.88, 1.71, P = 0.007). Among the participants with TT genotype per cent of individuals with S-IgA level of more than 1gL″1 was almost twice the percentage in CC genotype individuals (14% versus 7% respectively P = 0.01). Our data suggest that CC genotype of TGF-β1 polymorphism at codon 10 is associated with occurrence of Giardiasis. ©2009 Blackwell Publishing Ltd

Worldwide prevalence of emerging parasite Blastocystis in immunocompromised patients: A systematic review and meta-analysis

BACKGROUND: Blastocystis is one of the most common pathogens of the human intestine, caused by an emerging parasite, which can lead to severe symptoms and even death in immunocompromised patients. We aimed to determine the global prevalence of Blastocystosis infection in people with immunodeficiency. A systematic literature search was conducted on Web of Science, Scopus, Google scholar, Science Direct and MEDLINE databases to select all observational studies reporting the prevalence of Blastocystosis infection in Worldwide, based on different diagnostic methods in immunocompromised patients of any age and published from inception to February 2019. Pooled estimates and 95 confidence intervals (95 CIs) were calculated using random effects models and in addition, the I(2) statistic was calculated. The geographic distribution of studies was evaluated and the diagnosis of Blastocystis was compared by various techniques. Electronic databases were reviewed for Blastocystosis infection in HIV/AIDS, cancer and other immunocompromised patients, and meta-analyses were conducted to calculate the overall estimated prevalence. Total68 eligible studies were included. The estimated pooled prevalence rate of Blastocystosis infection in immunocompromised patients was overall 10 (95 CI, 7-13; I(2) 96.04) (P < 0.001), of whom 21 18-25 were in Australia, 12% 4-24 in America, 11% 6-17 in Europe and 10% 5-15, 7% 3-13 in Asia and Africa, respectively. It was calculated that the estimated pooled prevalence rate of Blastocystosis infection in immunocompromised patients was overall 10% and the prevalence estimates ranged from 0.44 to 72.39. Also, overall the prevalence of parasites co-infection in immunocompromised patients was detected as 0.024%. Our finding showed that immunocompromised people show a high prevalence of Blastocystosis infection compared to the control population. Adequate information on the prevalence rate is still missing from many countries. However, current information underscore that Blastocystis should not be neglected