Zinc oxide nanoparticles impact the expression of the genes involved in toxin-antitoxin systems in multidrug-resistant Acinetobacter baumannii

The aim of this study was to investigate the effect of zinc oxide nanoparticles (ZnO-NPs) on the expression of genes involved in toxin-antitoxin (TA) systems in multidrug-resistant (MDR) Acinetobacter baumannii. Seventy clinical isolates of A. baumannii were collected from variuos clinical samples. Antimicrobial susceptibility test was determined by disk diffusion. Type II TA system-related genes including GNAT, XRE-like, hipA, hipB, hicA, hicB were screened using polymerase chain reaction (PCR). ZnO-NPs prepared and characterized by field emission scanning electron microscopy and X-ray diffraction. MIC of ZnO-NPs of A. baumannii isolates was performed using the microdilution method. The expression of type II TA systems-related genes were assessed with and without exposure to ZnO-NPs using real-time PCR. The highest rate of resistance and sensitivity was observed against cefepime (77.14%), and ampicillin/sulbactam (42.85%), respectively. All A. baumannii isolates were considered as MDR. In this study, three TA loci were identified for A. baumannii including GNAT/XRE-like, HicA/HicB, and HipA/HipB and their prevalence was 100%, 42%, and 27.1%, respectively. There was no significant relationship between the prevalence of these systems and the origin of A. baumannii. Our data showed significant correlations between the presence of HicA/HicB system and resistance to ceftazidime, meropenem, imipenem, and cefepime (p < 0.05), and the presence of HipA/HipB system and resistance to ceftazidime, meropenem, imipenem, and cefepime (p < 0.05). In presence of ZnO-NPs, the expression of all studied genes decreased. GNAT and hicB showed the highest and lowest expression changes by 2.4 folds (p < 0.001) and 1.3 folds (p < 0.05), respectively. This study demonstrates the promising potential of nanoparticles to impact the expression of the genes involved in TA Systems. So, the application of ZnO-NPs may be helpful to design target-based strategies towards MDRs pathogens for empowered clinical applications by microbiologists and nanotechnologists.

How do nuclear factor kappa B (NF-κB)1 and NF-κB2 defects lead to the incidence of clinical and immunological manifestations of inborn errors of immunity?

INTRODUCTION

Genetic defects affect the manner of the immune system's development, activation, and function. Nuclear factor-kappa B subunit 1 (NF-κB1) and NF-κB2 are involved in different biological processes, and deficiency in these transcription factors may reveal clinical and immunological difficulties.

AREAS COVERED

This review article gathers the most frequent clinical and immunological remarkable characteristics of NF-κB1 and NF-κB2 deficiencies. Afterward, an effort is made to describe the biological mechanism, which is likely to be the cause of these clinical and immunological abnormalities.

EXPERT OPINION

The present review article has explained the mechanism of contributions of the NF-κB1 and NF-κB2 deficiency in revealing immunodeficiency symptoms, specifically immunological and clinical manifestations. These mechanisms demonstrate the importance of NF-κB1 and NF-κB2 signaling pathways for B and T cell development, activation, antibody production, and immunotolerance. The manifestation of a mutation can range from no symptoms to severe complications in a family.

Assessing empathy in final-year medical students using the Persian version of the Jefferson Scale of Physician Empathy

BACKGROUND

A doctor-patient relationship built on the concept of empathy is so essential to attain the best clinical outcomes in medicine. Since empathy has a positive role in interpersonal relationships and medical outcomes, its assessment is highly crucial. The aim of this study was to assess the empathy in last-year medical students using the Persian version of the Jefferson Scale of Physician Empathy (JSPE) and correlate empathy scores with demographic features.

MATERIALS AND METHODS

In this cross-sectional study, last-year medical students at Shiraz Medical School, Shiraz, Iran, were recruited for this study. In this research, we used the Persian version of JSPE. The validity and reliability of the Persian version of this tool were confirmed in the previous research. For the analysis of data, we employed descriptive statistics and the independent sample t-test.

RESULTS

One hundred and eighty-five final-year medical students were included in this study. The maximum score of the questionnaire was 140, and the total mean score of empathy was 98.15 ± 13.29. The females' total mean score (102.05 ± 11.89) was higher than the males' score (93.57 ± 13.46). The difference between the mean score of gender and empathy was significant (P value <.001), but there was no significant difference between empathy and the two other demographic factors (P > 0.05).

CONCLUSIONS

Although physicians would gain the essential characteristics of empathy during their career, attending professors and other responsible policymakers in medical education should focus more on the factors related to physicians' empathy to train better and more professional physicians.

SIRT1 gene polymorphisms associated with decreased risk of atherosclerotic coronary artery disease

Coronary artery disease (CAD) exhibits the rules of the multifactorial hereditary. Notwithstanding, the role of genetic factors in the prevalence of CAD is estimated very high. SIRT1 plays an athero-protective role and alterations in its expression have some important consequence in the metabolism, cholesterol, and fat deposition. The aim of our study was to investigate the association between rs4746720, rs12413112, and rs1467568 polymorphisms in the SIRT1 gene and CAD in the high-risk cases. In the present retrospective case-control study, 150 healthy individuals and 150 cases diagnosed with atherosclerotic lesions were investigated. ARMS PCR was used to determine the genotypes of rs4746720 polymorphism, while tetra primer-ARMS PCR was used for genotyping of rs12413112 and rs1467568 polymorphisms. Considering rs12413112 polymorphism, the frequency of the AG heterozygote genotype was significantly lower in cases than controls (P < 0.001). Furthermore, the frequency of the A-positive (AA+AG vs. GG) genotype was significantly different between groups (P < 0.001). The frequency of the variant A allele was 0.36% in cases and 0.46% in controls (P = 0.01). Except for a borderline protective effect in the present of rs1467568AG genotype, the allele and genotype distributions of both rs1467568 and rs4746720 polymorphisms did not differ between two groups. The haplotype constructed from rs1467568A, rs12413112A, and rs4746720T alleles showed a significant protective effect on the risk of CAD (OR: 0.53; 95%CI: 0.35-0.78; P = 0.001). In conclusion, the SIRT1 gene may contribute to the pathogenesis of CAD, while further investigations were suggested to confirm our results.

Soap-film flow induced by electric fields in asymmetric frames

Net fluid flow of soap films induced by (ac or dc) electric fields in asymmetric frames is presented. Previous experiments of controllable soap film flow required the simultaneous use of an electrical current passing through the film and an external electric field or the use of nonuniform ac electric fields. Here a single voltage difference generates both the electrical current going through the film and the electric field that actuates on the charge induced on the film. The film is set into global motion due to the broken symmetry that appears by the use of asymmetric frames. If symmetric frames are used, the film flow is not steady but time dependent and irregular. Finally, we study numerically these film flows by employing the model of charge induction in ohmic liquids.

SHuffle™ T7 strain is capable of producing high amount of recombinant human fibroblast growth factor-1 (rhFGF-1) with proper physicochemical and biological properties

BACKGROUND

Human fibroblast growth factor-1 (FGF-1) has powerful mitogenic activities in a variety of cell types and plays significant roles in many physiological processes e.g. angiogenesis and wound healing. There is increasing demand for large scale production of recombinant human FGF-1 (rhFGF-1), in order to investigate the potential medical use. In the present study, we explored SHuffle™ T7 strain for production of rhFGF-1.

METHODS

A synthetic gene encoding Met-140 amino acid form of human FGF-1 was utilized for expression of the protein in three different E. coli hosts (BL21 (DE3), Rosetta-gami™ 2(DE3), SHuffle™ T7). Total expressions and soluble/insoluble expression ratios of rhFGF-1 in different hosts were analyzed and compared. Soluble rhFGF-1 produced in SHuffle™ T7 cells was purified using one-step heparin-Sepharose affinity chromatography and characterized by a variety of methods for physicochemical and biological properties.

RESULTS

The highest level of rhFGF-1 expression and maximum soluble/insoluble ratio were achieved in SHuffle™ T7 strain. Using a single-step heparin-Sepharose chromatography, about 1500mg of purified rhFGF-1 was obtained from one liter of the culture, representing purification yield of ∼70%. The purified protein was reactive toward anti-FGF-1 ployclonal antibody in immunoblotting. Mass spectrometry confirmed the protein had expected amino acid sequence and molecular weight. In reverse-phase high-performance liquid chromatography (RP-HPLC), the protein displayed the same retention time with the human FGF-1 standard, and purity of 94%. Less than 0.3% of the purified protein was comprised of oligomers and/or aggregates as judged by high-performance size-exclusion chromatography (HP-SEC). Secondary and tertiary structures of the protein, investigated by circular dichroism and intrinsic fluorescence spectroscopy methods, respectively, represented native folding of the protein. The purified rhFGF-1 was bioactive and stimulated proliferation of NIH 3T3 cells with EC50 of 0.84ng/mL.

CONCLUSION

Although SHuffle™ T7 has been introduced for production of disulfide-bonded proteins in cytoplasm, we herein successfully recruited it for high yield production of soluble and bioactive rhFGF-1, a protein with 3 free cysteine and no disulfide bond. To our knowledge, this is the highest-level of rhFGF-1 expression in E. coli reported so far. Extensive physicochemical and biological analysis showed the protein had similar characteristic to authentic FGF-1.

Investigation of uranium (VI) adsorption by polypyrrole

The purpose of this study was to investigate the adsorption of uranium (VI) ions on the polypyrrole adsorbent. Polypyrrole was synthesized by a chemical method using polyethylene glycol, sodium dodecylbenzenesulfonate, and cetyltrimethylammonium bromide as the surfactant and iron (III) chloride as an oxidant in the aqueous solution. The effect of various surfactants on the synthesized polymers and their performance as the uranium adsorbent were investigated. Adsorbent properties were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) techniques. The effect of different parameters such as pH, contact time, initial metal ion concentrations, adsorbent dose, and the temperature was investigated in the batch system for uranium adsorption process. It has been illustrated that the adsorption equilibrium time is 7min. The results showed that the Freundlich model had the best agreement and the maximum adsorption capacity of polypyrrole for uranium (VI) was determined 87.72mg/g from Langmuir isotherm. In addition, the mentioned adsorption process was fast and the kinetic data were fitted to the Pseudo first and second order models. The adsorption kinetic data followed the pseudo-second-order kinetic model. Moreover, the thermodynamic parameters ΔG⁰, ΔH⁰ and ΔS⁰ showed that the uranium adsorption process by polypyrrole was endothermic and spontaneous.

Numerical study of soap-film flow by nonuniform alternating electric fields

Fluid flow of suspended liquid films induced by non-uniform alternating electric fields has been reported. The electric fields were generated by two rod-like electrodes perpendicular to the fluid surface. The observed fluid flow was explained qualitatively by considering a charge induction mechanism, where the electric field actuates on the charge induced on the film surface. In this paper we perform a numerical study of this fluid flow taking into account the charge induction mechanism. The numerical results are compared with experiments and good agreement is found. Finally, we propose the application of the device as a new kind of two dimensional fluid pump.

The effect of l-arginine supplementation on body composition and performance in male athletes: a double-blinded randomized clinical trial

BACKGROUND/OBJECTIVE

Athletes used a lot of dietary supplements to achieve the more muscle mass and improve their athletic performance. The objective of this study was to investigate the effect of l-arginine supplementation on sport performance and body composition in male soccer players.

SUBJECTS/METHODS

This double-blinded, randomized and placebo-controlled trial was conducted on 56 male soccer players, with age range of 16-35, who referred to sport clubs in Isfahan, Iran. Subjects were randomly assigned to either l-arginine or placebo groups. Athletes received daily either 2 g per day l-arginine supplement or the same amount of placebo (maltodextrin) for 45 days. Sport performance and also body mass index (BMI), body fat mass (BFM) and lean body mass (LBM) were measured at the beginning and end of the study. Also, 3-day dietary records were collected at three different time points (before, in the middle of, and at the end of the study).

RESULTS

The mean age of subjects was 20.85±4.29 years. Sport performance (VO₂ max) significantly increased in l-arginine supplementation group (4.12±6.07) compared with placebo group (1.23±3.36) (P=0.03). This increase remained significant even after adjustment of baseline values, physical activity and usual dietary intake of subjects throughout the study. No significant effect of l-arginine supplementation was found on weight, BMI, BFM and LBM.

CONCLUSIONS

l-arginine supplementation (2 g per day) could increase the sport performance in male athletes, but had no effect on anthropometric measurements, including BMI, BFM and LBM. So, further studies are needed to shed light our findings.

Rotation induced by uniform and non-uniform magnetic fields in a conducting fluid carrying an electric current

External magnetic field induces controllable rotation in a conducting fluid carrying an electric current.

PAMAM dendrimers augment inhibitory effects of curcumin on cancer cell proliferation: possible inhibition of telomerase

BACKGROUND

Despite numerous useful anticancer properties of curcumin, its utility is limited due to its hydrophobic structure. In this study, we investigated the comparative antiproliferative effect of PAMAM encapsulating curcumin with naked curcumin on the T47D breast cancer cell line.

MATERIALS AND METHODS

Cytotoxic effects of PAMAM dendrimers encapsulating curcumin and curcumin alone were investigated by MTT assay. After treating cells with different concentrations of both curcumin alone and curcumin encapsulated for 24h, telomerase activity was determined by TRAP assay.

RESULTS

While PAMAM dendrimers encapsulating curcumin had no cytotoxicity on cancer cells, they decreased the IC50 for proliferation and also increased the inhibitory effect on telomerase activity.

CONCLUSIONS

Considering the non-toxicity in addition to effectiveness for enhancing curcumin anticancer properties, dendrimers could be considered good therapeutic vehicles for this hydrophobic agent.

Evaluation of seed and seedling emergence enhancement of some population of Sahandy savory (Satureja sahendica) by gibberlic acid, potasium nitrate, pre-cooling, physical and chemical scarification treatment

In greenhouse experiment, the seed samples of 3 populations were treated with treatments including: cold stratification, Gibberlic Acid (50 ppm and 100 ppm), Potassium nitrate (0.2%, 0.4%), physical scarification (sand paper), chemical scarification (Ethylic alcohol 70%) and distilled water (control), then these treated seed samples were sown in pots as randomize design with three replication. The germination characteristics including: germination percentage, speed of germination, length of root and shoot, seedling length, ratio of root length by shoot length, vigor index, fresh weight arid dry weight, ratio of dry weight by fresh weight were evaluated during 45 days of experiment. Comparing between three populations of Sahandy savory, seed germination characteristics of the Ghazvin population was higher than the other two populations. According to effect of treatment on germination seed characteristics, the species of savory and their population, it was concluded that effect of Gibberlic Acid and Potassium nitrate was higher than physical scarification and chemical scarification comparing with control. With more effective of gibberlic acid and KNO3 and cold treatment on seed germination enhancement of the population, it was clarified that the type of dormancy of some population of Sahandy savory was physiological dormancy.

Inhibition of leptin gene expression and secretion by silibinin: possible role of estrogen receptors

Leptin plays the role of mitogenic factor in the breast carcinogenesis. Therefore, it could be considered as a target for breast cancer therapy. Leptin gene expression could be modulated by activation of estrogen receptors. Silibinin is an herbal compound with anti-cancer activity on prostate and colorectal cancers. Based on the fact that targeting of leptin can be considered as a novel strategy for breast cancer therapy, the aim of this study was the investigation of potentiality of silibinin for inhibition of leptin gene expression and secretion, and its link with expression of estrogen receptors. Cytotoxic effect of silibinin on T47D breast cancer cells was investigated by MTT assay test after 24, 48 and 72 h treatments with different concentrations of silibinin. The levels of leptin, estrogen receptor α and estrogen receptor β genes expression was measured by reverse-transcription real-time PCR. The amount of secreted leptin in the culture medium was determined by ELISA. Data were statistically analyzed by one-way ANOVA test. Silibinin inhibits growth of T47D cells in a time and dose dependent manner. There was significant difference between control and treated cells in the levels of leptin, estrogen receptor β expression levels and the quantity of secreted leptin was decreased in the treated cells in comparison to control cells. In conclusion, silibinin inhibits the expression and the secretion of leptin and in the future it might probably be a drug candidate for breast cancer therapy through leptin targeting.

The role of exon 45 and 16 in the pathogenesis of Von Willebrand disease in Iranian Patients

BACKGROUND

Von Willebrand disease (VWD) is an autosomal recessive congenital bleeding disorder with deficiency or dysfunction of von Willebrand factor (VWF). The gene encoding for the VWF is located on chromosome 12, which is 178 Kb with 52 exons. Various mutations of this gene is responsible for the clinical features of VWD, but some single nucleotide polymorphisms make the molecular diagnosis of it very complicated.In this study genetic variations in two exons (45 & 16) of VWF gene in Iranian patients suffer from type 3 VWD from south west of Iran were evaluated.

MATERIALS AND METHODS

Genetic variations in exon 45 and exon 16 of VWF gene were evaluated in 33 patients diagnosed with type 3 VWD from south west of Iran. Two exons with their flanking introns were amplified by PCR and amplicons were analyzed by sequencing for any molecular changes.

RESULTS

No mutation was found in both selected regions. An A/C polymorphism in intron 44 was recognized in all patients in homozygous manner. This SNP reported for the first time from Iranian VWD patients.

CONCLUSION

Mutation of VWF gene is different in various ethnic groups, which finding of is important in the diagnosis of the VWD, especially for prenatal diagnosis. A few mutations are reported for exon 45 and 16 of this gene in Iran and other countries. But, present study didn't find any mutation in these patients. Mutation in other exons or introns should be evaluated in affected individuals from south west of Iran.

The Possible Impact of Obesity on Androgen, Progesterone and Estrogen Receptors (ERα and ERβ) Gene Expression in Breast Cancer Patients

BACKGROUND

Obesity has been associated with increased mortality from hormone dependant cancers such as breast cancer which is the most prevalent cancer in women. The link between obesity and breast cancer can be attributed to excess estrogen produced through aromatization in adipose tissue. The role of steroid hormone receptors in breast cancer development is well studied but how obesity can affect the expression pattern of steroid hormones in patients with different grades of breast cancer was the aim of this study.

METHODS

In this case-control study, 70 women with breast cancer participated with different grades of obesity (36 none obese, BMI < 25 kg/m(2) and 34 obese, BMI ≥ 25 kg/m(2)). The mean age of participants was 44.53 ± 1.79 yr (21-70 yr). The serum level of estrogen, progesterone and androgen determined by ELISA. Following quantitative expression of steroid hormone receptors mRNA in tumor tissues evaluated by Real-time PCR. Patients with previous history of radiotherapy or chemotherapy were excluded. SPSS 16 was used for data analysis and P < 0.05 considered statistically significant.

RESULTS

The difference in ERα, ERβ and PR mRNA level between normal and obese patients was significant (P < 0.001). In addition, the expression of AR mRNA was found to be higher than other steroid receptors. There was no significant relation between ERβ gene expression in two groups (P = 0.68). We observed a significant relationship between ERα and AR mRNA with tumor stage and tumor grade, respectively (P = 0.023, P = 0.015).

CONCLUSION

According to the obtained results, it is speculated that obesity could paly a significant role in estrogen receptors gene expression and also could affect progression and proliferation of breast cancer cells.

Compound KIR-HLA genotype analyses in the Iranian population by a novel PCR-SSP assay

Natural killer (NK) cells eliminate infected and transformed cells while still are self-tolerant. Interactions of the independently segregating Killer cell immunoglobulin-like receptors (KIR) and human leucocyte antigens (HLA) loci play a critical role in NK cell regulation. Different compound KIR-HLA genotypes can impart different thresholds of activation to the NK-cell repertoire and such genotypic variation has been found to confer altered risk in a number of human diseases including viral infections, autoimmune disorders, reproduction abnormalities and cancers. In this study, we presented a novel combined KIR-HLA polymerase chain reaction-sequence-specific primers genotyping assay for simultaneous determination of KIR genes and their three major HLA class I ligand groups (C1, C2, and Bw4). Moreover, known inhibitory and activating KIR + HLA (iKIR + HLA: 2DL2/3 + C1, 2DL1 + C2, 3DL1 + Bw4; and aKIR + HLA: 2DS2 + C1, 2DS1 + C2, 3DS1 + Bw4) combinations as well as co-inheritance of aKIR genes and iKIR + HLA pairs were analysed in a total of 200 unrelated healthy Iranian individuals. All tested subjects had at least one of the three iKIR + HLA pairs and the frequencies of various inhibitory combinations in the study group were: 31.5%, three iKIR + HLA pairs, 53.5%, two iKIR + HLA pairs, and 15%, 0ne iKIR + HLA pair. Furthermore, we revealed that majority of Iranians (69%) carry compound genotypes with greater number of inhibitory pairings than activating combinations (iKIR + HLA > aKIR + HLA). Conversely, iKIR + HLA < aKIR (45%) was dominant genotype in the study group. We conclude that selective evolutionary pressure has propensity to maintain KIR-HLA genotypes with more inhibitory combinations to guarantee self-tolerance. In contrast, existence of activating KIR genes without normal endogenous ligands, potentially arms the NK population for competent immunosurveillance and stronger defense against infections.

Preparation and Characterization of Expandable St/MMA Copolymers Produced by Suspension Polymerization

Free radical suspension copolymerization of styrene (St) with methyl methacrylate (MMA) in the presence of n-pentane was investigated. The batch polymerization was performed in a stirred reactor via a two-stage process. First, free radical suspension polymerization of St and MMA in aqueous media was carried out at about 80—90°C with the aid of a monofunctional initiator to the monomer conversions up to about 70%. Second process, called impregnation stage, consisted of a high temperature—high pressure cycle (110—120°C and 10 bars) in which the blowing agent was charged in the reactor and polymerization was carried out with the aid of a high temperature initiator. Fine particles of micron sizes of St/MMA copolymer were synthesized by manipulation of some experimental parameters governing the copolymerization system. Polymerization was carried out at different agitation rates, suspending agent and aqueous phase initiator concentrations as well as emulsifier amounts, while keeping constant the MMA/St ratio. To reach a desired bead size, the above parameters were optimized using the Taguchi method for experimental design and the relative importance of the mentioned parameters was analyzed. Particles with a spherical shape of 250—350 μm were formed. The obtained copolymers were also characterized in terms of molecular weight, polydispersity index, copolymer composition, morphology of the polymer beads, thermal behavior, and particle size and particle size distribution.

Pain Affects Health-Related Quality of Life in Kidney Transplant Recipients

BACKGROUND

Chronic pain is prevalent in end-stage renal disease patients undergoing chronic hemodialysis. We do not fully know the intensity of chronic pain experienced by kidney recipients in comparison to those on chronic hemodialysis and healthy controls. Moreover, the effect of chronic pain on kidney recipients' health-related quality of life (HRQoL) is yet to be comprehensively addressed. We designed this study to find an answer to these questions.

METHODS

In this case control study, we studied 205 kidney recipients, 69 hemodialysis patients, and 100 healthy controls, who were matched for age, sex, monthly family income, and educational level. The patients were evaluated for the intensity of chronic pain by Visual Analogue Scale (VAS). HRQoL was measured with Short Form 36 (SF-36) in the kidney recipients. Chronic pain intensity was compared in the study groups, and in the kidney recipients the correlation between SF-36 subscores and severity of pain was assessed.

RESULTS

Severity of pain in the kidney recipients was lower than the hemodialysis patients, but more than the healthy controls (P=.001). The VAS pain score negatively correlated with the scores of SF- 36 total (r=-.329, P=01), mental health (r=-.190, P=07), physical health (r=-.275, P=.001), physical function (r=-.339, P=.001), role limitation due to physical problems (r=-.478, P=.001), role limitation due to emotional problems (r=-.326, P=.001), and bodily pain (r=-.894, P=.001).

DISCUSSION

The intensity of chronic pain experienced by the kidney recipients is less than that experienced by patients under chronic hemodialysis, but higher than healthy subjects. Focusing on chronic pain as a cause of post-renal transplantation morbidity is expected to improve post-renal transplantation quality of life.

Effects of passive smoking on common respiratory symptoms in young children

AIM

To observe the effects of fathers' smoking on respiratory symptoms in children between the ages of 6 mo and 5 y living in Tehran during the period January to December 2001.

METHODS

The caregivers of 622 children attending resident-based clinics in two university hospitals were interviewed about the respiratory illnesses incurred by the child during the previous 12 mo and the smoking habits of those living with the child. Children who lived in households in which any person, other than the father, smoked were excluded.

RESULTS

The analysis included 595 children, 40.6% of whom were living in homes where fathers smoked cigarettes. About 35% of smokers admitted to unrestricted smoking at home. In children not living with a smoker, 81.6% had experienced at least one episode of upper respiratory tract infection (URTI) during the previous year and the rate increased to 95.2% in passive smokers whose fathers were not restricted from smoking in front of the children, (p-value <0.01). A similar pattern was found for otitis media and asthma (p-value <0.05 and <0.01, respectively). The average number of URTI episodes during the previous year was significantly higher in children exposed to unrestricted smoking (p <0.01).

CONCLUSION

The study outlines the detrimental effects of paternal smoking on the respiratory health of children from a part of world in which this problem has not been studied previously, and highlights the importance of educating fathers to alter their smoking habits so that even if they do not stop smoking altogether, they should discontinue smoking indoors.

Prevalence of Helicobacter pylori vacuolating cytotoxin and its allelic mosaicism as a predictive marker for Iranian dyspeptic patients

Helicobacter pylori infects the majority of the population in the developing countries. However, the rate of gastrointestinal complications such as peptic ulcers and gastric malignancies has no parallel with the infection. In order to determine whether cytotoxin (vacA) and its allelic polymorphism can serve as screening markers for such a population, H. pylori strains were isolated from one hundred and thirty two dyspeptic patients. H. pylori genomic DNA was extracted and underwent PCR-amplification for the cytotoxin alleles. Genotyping of the signal sequence region of the vacA gene identified 68% (70 out of 103) of patients with non ulcer dyspepsia (NUD) and 79% (23 out of 29) of the patients with peptic ulcer disease (PUD) possessing the s1 genotype. S1 strains were significantly more prevalent among patients with PUD as compared to the NUD (p < 0.05). In regard to the middle region, 55% of the patient isolates belonged to the m2 genotype with no correlation to disease. The s1m2 genotype was the most prevalent among all patients and significantly correlated with the PUD group (p < 0.05).

Enzyme-linked immunosorbent assay for the specific detection of the mercapturic acid metabolites of naphthalene

The measurement of metabolites constitutes a useful tool for detection of exposure and in pharmacokinetic studies. Epoxidation with subsequent glutathione conjugation and mercapturic acid formation is an important deactivation pathway for naphthalene, a toxin which presumably causes lung disease. The mercapturic acid conjugates of naphthalene [NaphMA (1), N-acetyl-S-(1,2-dihydro-1-hydroxy-2-naphthyl)cysteine (1a), and N-acetyl-S-(1,2-dihydro-2-hydroxy-1-naphthyl)cysteine (1b)], its most important urinary metabolites, and other structurally related derivatives, such as N-acetyl-S-(1,2,3,4-tetrahydro-2-hydroxy-1-naphthyl) cysteine (2), N-acetyl-S-(3-hydroxy-1,2,3,4-tetrahydro-2-naphthyl)cysteine (3), and N-acetyl-S-(2-hydroxy-1-phenylethyl)cysteine (4a) and N-acetyl-S-(2-hydroxy-2-phenylethyl)cysteine (4b) as an isomeric mixture, were synthesized to develop an ELISA (enzyme-linked immunosorbent assay) for the specific detection of NaphMA (1). Compound 1, as an isomeric mixture, was used to raise antibodies by immunizing six rabbits with the corresponding KLH (keyhole limpet hemocyanin) and BSA (bovine serum albumin) derivatives (1KLH and 1BSA). The remaining compounds were covalently attached to BSA, conalbumin, and ovalbumin to be used as coating antigens. The best assay was obtained in a homologous system combining serum Ab2357 (1KLH) and 1BSA as coating antigen. The immunoassay has an I50 of 4-6 ng/mL and a detection limit of 1-2 ng/mL. Because of the known instability of the mercapturic acid conjugate of naphthalene 1, leading to the fully aromatic compound 20, a system involving HPLC is described to check the stability of the NaphMA stock solutions used in the assay. Cross-reactivity studies show high specificity toward the NaphMA. Other related compounds as well as the dehydrated derivative 20 are not recognized by the antibody in this ELISA system.

Application of ELISA techniques to metabolic disposition studies for 1,3-dinitrobenzene: comparison with HPLC and radiochemical methods

An enzyme-linked immunosorbent assay (ELISA) is reported for the detection and quantitation of 1,3-dinitrobenzene, a widely used chemical intermediate in industrial syntheses and potent testicular toxicant in rats. Radiolabeled [14C]-1,3-dinitrobenzene (25 mg/kg, ip) was administered to rats, and the blood disappearance curve generated with the ELISA assay was compared with HPLC separation and quantitation by using both UV and radiochemical methods. An excellent correlation was found between the two methods. Matrix effects from the blood samples were minimal. Cross reactivity with metabolites of 1,3-dinitrobenzene occurred only at levels that were 3 orders of magnitude greater than for the parent compound. The specificity of the ELISA for 1,3-dinitrobenzene was further demonstrated with a variety of other nitroaromatic compounds, of which only 2,4-dinitrotoluene showed significant cross reactivity. The sensitivity and specificity of the 1,3-dinitrobenzene ELISA demonstrate the usefulness of an approach which, if verified with conventional analytical methods, allows rapid and inexpensive measurement of xenobiotic levels in biological samples.