Comparing changes in transient-evoked otoacoustic emission and pure-tone audiometry following short exposure to industrial noise

It has been suggested that otoacoustic emissions, particularly transient-evoked otoacoustic emissions (TEOAE), might be more sensitive in assessment of changes to the cochlea caused by noise than pure-tone audiometry (PTA). The aim of the study was to compare temporary threshold shifts with the changes in TEOAE following a six-hour exposure to industrial noise at the intensity of 85-97 dB (A). Thirty two male employees of a metal factory were screened. TEOAE, PTA and tympanometry were included in the hearing test battery. Both, PTA and TEOAE showed significant reduction due to noise exposure, but no correlation between temporary threshold shifts and decreases in either the overall TOAE level or the level of otoacoustic emission in the frequency bands was found. Our results confirm the high sensitivity of TEOAE to short exposure to industrial noise. This study may recommend this measurement as a method of evaluation for TTS conditions for hearing conservation programme purposes, in addition to pure-tone audiometry.     

Synthesis, and antiprotozoal and antibacterial activities of S-substituted 4,6-dibromo- and 4,6-dichloro-2-mercaptobenzimidazoles.

The synthesis and some germicidal activities in vitro of two congener series of S-substituted 4,6-dihalogeno-2-mercapto-1H-benzimidazoles are reported. There was no substantial difference between antibacterial activities of corresponding 4,6-dichloro- and 4,6-dibromo-derivatives. The present results confirm lower susceptibility to substituted benzimidazoles of Gram-negative compared to Gram-positive bacteria. Minimum inhibitory concentrations (MICs) of a majority of the novel derivatives ranged between 25 and 100microg/ml for Gram-positive bacteria. The most active compounds (MICs for Gram-positive bacteria: 0.78-50microg/ml) were 4,6-dichloro-2-(4-nitrobenzylthio)-1H-benzimidazole and 4,6-dibromo-2-(4-nitrobenzylthio)-1H-benzimidazole that were 4-32 times more potent than nitrofurantoin against all Gram-positive bacteria utilized but Escherichia faecalis, against which they were, respectively, 2 and 4 times less potent than nitrofurantoin. Among Gram-negative bacteria used, Stenotrophomonas maltophilia and Bordetella bronchiseptica were most sensitive (as evidenced by a number of MICs 400microg/ml). All the new compounds were at least several times more active against Giardia intestinalis (IC(50): 0.006-0.053microg/ml), and a half of them were at least several times more active against Trichomonas vaginalis (IC(50): 0.0015-0.182microg/ml) than metronidazole (IC(50): 0.210 and 0.037microg/ml, respectively), the drug of choice in the treatment of G. intestinalis and T. vaginalis infections.     

Oncology research in Saudi Arabia over a 10-year period: A synopsis

Objectives:To assess the quality and quantity of Saudi publications in oncology over a 10-year period.Methods:A systematic PubMed search was conducted between January 2008 and December 2017 to retrieve all Saudi oncology publications. Data about the articles was collected. The level of evidence (LOE) was independently assessed by 2 authors. Two 5-year periods (2008-2012 and 2013-2017) were compared using the relevant parameters. Clinicaltrials.gov was also searched for all oncology trials registered in Saudi Arabia.Results:A total of 839 publications met our inclusion criteria. The most common type of research was case series, totaling 32% of all publications. Clinical trials formed less than 2% of the total. The LOE was I, II, III, and IV in 0.3%, 2.1%, 58.4%, and 39.3% of the included publications, respectively. The LOE was the same in the 2 periods. There were more publications in international journals (p=0.004), more international collaborations (p=0.001), and higher journal impact factors (p=0.037) in 2013-2017 than in 2008-2012. Only 76 registered clinical trials were found in the Clinicaltrials.gov registry.Conclusion:Despite an increase in the number of Saudi publications in the field of oncology over time, the LOE did not change. There were, however, some improvements in the international collaboration and journal impact factor, as well as an increase in the number of studies published in international journals. These observations call for a national strategy to improve oncology research in Saudi Arabia.     

Synthesis and structure evaluation of new complex butylarylpiperazin-1-yl derivatives

A series of arylpiperazine derivatives of 1,16-diphenyl-19-azahexacyclo-[14.5.1.0^2,15.0^3,8.0^9,14.0^17,21]docosa-2,3,5,7,8,9,11,13,14-nonaene-18,20,22-trione and 4,10-diphenyl-1H,2H,3H,5H-indeno[1,2-f]isoindole-1,3,5-trione was synthesized. The pharmacological profile of compound 4 at the 5-HT_1A receptor was measured by binding assay. The title compounds were tested in cell-based assay against the human immunodeficiency virus type-1. The X-ray crystallographic studies of derivatives 2, 6, 7, 11, 19, and 20 were presented.