The Effect of Active and Passive Smoking on Hearing Loss in Noise-Exposed Metal Workers.

Background: Many people are exposed to cigarette smoke actively or passively. We aimed to determine the effect of active and passive smoking on hearing thresholds and hearing loss noise-exposed workers. Methods: This cross-sectional study was conducted on 929 metal workers. We divided the workers into 3 groups according to smoking status-current smokers, nonsmokers, and passive smokers. Audiometric testing was recorded for both ears. Hearing loss was defined by 3 models. The SPSS software Version 24 was used to analyze the collected data. We used an independent t test, chi-square, Fisher exact, and analysis of variance tests and logistic regression, and the significance level was set at P ˂0.05 to interpret the relationships between variables. Results: The hearing threshold levels at 4000 Hz, high frequencies, and low frequencies were significantly higher in smokers than nonsmokers (P < 0.05). Also, and hearing loss at the 4000 Hz (P = 0.002; odds ratio [OR] = 1.96; 95% CI = 1.27-3.03) and high frequencies (P = 0.001; OR = 2.15; 95% CI = 1.36-3.4) had a significant correlation with smoking. Hearing loss was significantly correlated with passive smoking at 4000 Hz (P < 0.001; OR = 5.87; 95% CI = 3.29-10.47), high frequencies (P < 0.001; OR = 7.16; 95% CI = 3.97-12.89) and low frequencies (P = 0.021; OR = 4.16; 95% CI = 1.12-15.43). Conclusion: The findings show that active and passive smokers who work in noisy environments are at higher risk for noise-induced hearing loss. Therefore, smoking cessation in smoker workers and reduction of environmental exposure to cigarette smoke is necessary to reduce the exacerbation of hearing loss. Moreover, more attention should be paid to passive smokers and they should be given priority in the same programs.

Curcumin nanoparticles containing poloxamer or soluplus tailored by high pressure homogenization using antisolvent crystallization.

Curcumin is a natural active constituent of Curcuma longa from Zingiberaceae family that shows many different pharmacological effects such as anticancer, antioxidant, anti-inflammatory, antimicrobial and antiviral effect. However, its bioavailability is profoundly limited by its poor water solubility. In this study antisolvent crystallization followed by freeze drying was used for the preparation of curcumin nanoparticles. The presence of different ratios of hydrophilic polymers (poloxamer 188 & soluplus) on physicochemical properties of curcumin nanoparticles was also investigated. In addition, the effect of high pressure homogenization (HPH) on solubility and dissolution properties of curcumin was investigated. All nanoparticle formulations were examined to determine their particle size distribution, saturation solubility, morphology (SEM), solid state (DSC, XRPD and FT-IR) and dissolution behavior. It was observed that curcumin crystallized in the presence of polymers exhibited better solubility and dissolution rate in comparison with original curcumin. The results showed that the concentration of the stabilizer and the method used to prepare nanoparticles can control the dissolution of curcumin. The crystallized nanoparticles showed polymorph 2 curcumin with lower crystallinity and higher dissolution rate. Curcumin nanoparticles containing 50% soluplus prepared via HPH method presented 16-fold higher solubility than its original form. In conclusion, samples crystalized and proceed with HPH technique showed smaller particle size, better re-dispersibility, higher solubility and dissolution rate in water compared with a sample prepared using a simple antisolvent crystallization process.

Effect of high pressure homogenization on physicochemical properties of curcumin nanoparticles prepared by antisolvent crystallization using HPMC or PVP.

Dissolution enhancement of poorly water soluble drugs is a major challenge in pharmaceutical industry. The aim of this study is to fabricate curcumin nanoparticles by antisolvent crystallization in the presence of PVP-K30 or HPMC with various concentrations as a stabilizer. The effect of high pressure homogenization on properties of curcumin particles is also investigated in this study. The antisolvent crystallization method followed by freeze drying (CRS-FD) and also antisolvent crystallization and high pressure homogenization followed by freeze drying (HPH-FD) were employed to modify curcumin particles. Physical mixtures of the drug and additives were also prepared for comparison purposes. The solid state analysis (DSC, XRPD and FT-IR studies), particle size measurement, morphological analysis, saturation solubility and dissolution behavior of the samples were investigated. The curcumin crystallized without using stabilizer produced polymorph 2 curcumin with lower crystallinity and higher solubility. The samples obtained in the presence of stabilizers showed higher solubility compared to its physical mixtures counterpart. It was found that the stabilizers used in the current study were capable of inhibiting the crystal growth of particles during crystallization. High pressure homogenizer method generated smaller particles compared to those samples that were not subjected to high pressure homogenizer (for example, 2748 nm for 5% PVP CRS-FD sample and 706 nm for 5% PVP HPH-FD sample). Particles obtained via HPH showed better solubility and dissolution rate compared to those samples that HPH was not employed (for example, the saturated solubility of 25% PVP CRS-FD sample was near 2 µg/ml while this amount was approximately 4.3 µg/ml for 25% HPH-FD sample. The effect of high pressure homogenization on dissolution rate is more pronounced for samples with lower stabilizer ratio. The samples prepared with high pressure homogenizer using 50% PVP showed 25-fold higher solubility compared to untreated curcumin. Generally, it can be concluded that the method of preparation, selection of suitable stabilizer and concentration of stabilizer play a critical role on particle size and dissolution rate of curcumin.

False positive seroreactivity to brucellosis in tuberculosis patients: a prevalence study.

BACKGROUND: The rising worldwide incidence of tuberculosis (TB) increases the demand for knowledge about its potential seroreactivity with other microbial agents. A few reports and the authors' experiences indicate that tuberculosis may result in a false-positive brucellosis serology. This may cause a diagnostic challenge because of the close clinical resemblance of these two infections. OBJECTIVE: The aim of the present prevalence study was to elucidate brucellosis seroreactivity in patients with active TB. METHODS: Ninety-eight patients with newly diagnosed and active TB were studied using an enzyme-linked immunosorbent assay (ELISA) and Wright's and Coombs-Wright's tests. Seventy-five healthy individuals were used as controls. The patients showed signs of recovery after starting a standard anti-TB regimen and had no clinical evidence of brucellosis at a subsequent 6-month follow-up. The data were analyzed statistically by Fisher's exact test using SPSS 11.0. RESULTS: We found that 9.2% of TB patients versus 1.3% of healthy controls had positive results on the anti-Brucella IgG ELISA (P = 0.04). Five TB patients were found to have agglutination on Wright's tests, while none of the controls showed agglutination. CONCLUSION: Active TB patients may have some seroreactivity with Brucella antigens, and Brucella IgG ELISA may give a false positive in these patients. Clinicians should consider false positive brucellosis seroreactivity in patients with active TB.