Noise-induced hearing loss among manufacturing factory workers in Kuching, Sarawak: Prevalence and associated risk factors.

INTRODUCTION: Noise-induced hearing loss (NIHL) is a common problem worldwide. Increased globalisation, as well as industrialisation, gives rise to an increase in the incidence of NIHL worldwide. Malaysia is not spared from this problem, either. The objectives were to determine the prevalence of NIHL and its associated factors among manufacturing factory workers. MATERIAL AND METHODS: A cross-sectional study was done in Kuching, Sarawak, involving 173 randomly selected respondents among manufacturing factory workers. Data collected were respondents' workplace monitoring data and their audiometry records obtained from the factory record, and the otoscopy examinations performed. In addition, respondents were required to fill up an interviewer-guided questionnaire. RESULTS: The prevalence of NIHL was high (49.7%). The factors which were found to have a significant association with NIHL in bivariate analysis were age (p < 0.05, 95% CI), male gender (p < 0.05; OR - 7.60; CI 3.34 -18.38), duration of employment (p <0.05), knowledge of noise level (p < 0.05; OR - 4.11; CI 1.10 - 15.28), working at polishing department (p < 0.05; OR - 4.23; CI 2.13 - 8.43), and smoking (p < 0.05; OR - 39.6; CI 16.5 - 94.8). Pack-years of smoking were also found to have a significant association with p < 0.05. However, only smoking was statistically significant in multivariate analysis, where the risk of developing NIHL was 27.55 (p < 0.005; CI 10.74 - 70.64) among smokers. CONCLUSION: The high prevalence of NIHL despite the existing Hearing Conservation Program (HCP) may indicate that there may be some elements in HCP that require close monitoring by the factory management, and the importance of smoking cessation among the workers exposed to noise at the workplace should be highlighted.

Aspergillus niger trehalase enzyme induced morphological and protein alterations on Acanthamoeba cyst and molecular docking studies.

The cytotoxicity of Acanthamoeba is yet to fully illustrate due to recalcitrant of Acanthamoeba during cyst stage. The formation of the trehalose layer at the cyst stage protects the inner components of this opportunist protozoan parasite. Trehalase from the Aspergillus niger (AnTre) activity on the cyst of Acanthamoeba was determined based on AnTre dose-response, morphological and protein changes. The interaction of the AnTre and trehalose was also visualized through docking simulation. Vacuolation of the cyst can be seen when observed under light microscopy. Membrane integrity assessment suggested possible hydrolization of the AnTre enzyme to trehalose membranes which based on acridine orange and propidium iodide staining. Surface morphology based on scanning electron microscopy revealed the formation of bulging structure that was also proved through cross sectioning observed by transmission electron microscopy. Loss of internal structure of the cysts was clearly observed. Other morphological distinction where loss of rigid shape due to the destruction of the endo- and ecto cyst layers. However, the protein profile exhibits change of trehalose layer as responses to AnTre treatment. The observed biological results were also supported by interaction simulation based on molecular docking between trehalose and AnTre enzyme. In conclusion, this enzymatic approach could be developed into selective and effective mechanism to control Acanthamoeba without affecting the host especially mammals due to the absence of trehalose elements in the tissues of mammals.

The prevalence of anatomical variations in osteomeatal unit in patients with chronic rhinosinusitis.

INTRODUCTION: The complexities of the anatomy of the nose and paranasal sinuses, as well as its variations may create technical difficulties during surgery. The significance of these anatomical variations in pathogenesis of rhinosinusitis, which is the commonest disease in the region, is still unclear. OBJECTIVE: The aims of the study were to study the anatomical variations in the osteomeatal complex in chronic rhinosinusitis (CRS) patients and to compare them with the normal population. METHODOLOGY: High resolution CT scan of paranasal sinuses images of 240 individuals were reviewed comparing 120 cases of CRS and another 120 patients without CRS problem. RESULTS: The anatomical variations recorded were: Concha bullosa in 49 (40.8%) CRS cases and 57 (47.5%) in control cases, paradoxical middle turbinates in 14 (12.0%) CRS cases and 27 (23.0%) in control cases, pneumatized uncinate processes were found in 3 cases (3.3%) in both CRS and control groups, Haller's cells (infraorbital ethmoid cell) in 61 (51.0%) CRS cases and 75 (62.0%) cases in the control group, there were pneumatized agger nasi cells in 100 (83.0%) CRS cases and 95 (79.0%) in control subjects and deviated nasal septums in 67 (56.0%) CRS cases compared with 73 (60.8%) in controls. CONCLUSION: The most common anatomical variation in the osteomeatal complex in CRS patients was pneumatized agger nasi cells and the least was pneumatized uncinate processes. However the prevalence among both groups is comparable. The detection of a single anatomical variant itself does not establish the genesis of chronic rhinosinusitis except for paradoxical middle turbinate and infraorbital ethmoid cells.

Development and partial characterization of new marine cell line from brain of Asian sea bass Lates calcarifer for virus isolation.

A new cell line, Asian sea bass brain (ASBB), was derived from the brain tissue of Asian sea bass Lates calcarifer. This cell line was maintained in Leibovitz L-15 media supplemented with 10% fetal bovine serum (FBS). The ASBB cell line was subcultured more than 60 times over a period of 15 mo. The ASBB cell line consists predominantly of fibroblastic-like cells and was able to grow at temperatures between 20°C and 30°C with an optimum temperature of 25°C. The growth rate of these cells increased as the proportion of FBS increased from 2% to 20% at 25°C with optimum growth at the concentrations of 10% or 15% FBS. Polymerase chain reaction products were obtained from ASBB cells and tissues of sea bass with primer sets of microsatellite markers of sea bass. An isolate of piscine nodavirus from juveniles of marine fish species tested positive by IQ2000 kit for viral nervous necrosis detection and was examined for its infectivity to a fish cell line of ASBB. A marine fish betanodavirus was tested to determine the susceptibility of this new cell line in comparison with commercial highly permissive SSN-1 cells. The ASBB cell line was found to be susceptible to nodavirus (RGNNV genotype), and the infection was confirmed by comparison cytopathic effect (CPE) with commercial SSN-1 and reverse transcriptase-polymerase chain reaction. A nodavirus was further elucidated by electron microscopy, and the virus tested was shown to induce CPE on ASBB cells with significant high titer. This suggests that the ASBB cell line has good potential for the isolation of fish viruses.

Multispecies impingement in a tropical power plant, Straits of Malacca.

Marine organisms comprised about 70% of the total impinged materials by weight at water intake screens in the Kapar Power Station (KPS), Malaysia. The general groupings of 'fish', 'shrimp', 'crab', 'cephalopod' and 'others' contributed 26% (87 species), 65% (29), 2% (17), 2% (3) and 5% (42) of the total number of impinged organisms, respectively. In general, higher impingement occurred during spring tide, at nighttime and in shallow water. The glass perchlet, anchovies, ponyfishes, mojarra, catfishes, hairtail, scat and young croakers were the most vulnerable fishes. Vulnerable invertebrates included cephalopods, sea urchin, rockshells and jellyfishes, but penaeid shrimps were the most susceptible in terms of both mortality and body injury. Annually, KPS is estimated to kill 8.5 x 10(6) marine organisms (42 tons) by impingement. This amount, however, is minimal compared to commercial fishery harvests. Multispecies impingement at Malaysian power plants poses the problem of finding the best mitigation options for tropical situations.

Poly(vinyl alcohol) : a potential matrix for glucose oxidase immobilization?

Considerable effort has been focused on the method of immobilizing glucose oxidase (GOD) for amperometric glucose biosensors since the technique employed may influence the available activity of the enzyme and thus affect the performance of the sensor. Narrow measuring range and low current response are still considered problems in this area. In this work, poly(vinyl alcohol)(PVA) was investigated as a potential matrix for GOD immobilization. GOD was entrapped in cross-linked PVA. The use of a PVA-GOD membrane as the enzymatic component of a glucose biosensor was found to be promising in both the magnitude of its signal and its relative stability over time. The optimum PVA-GOD membrane (cross-linking density of 0.06) was obtained through careful selection of the cross-linking density of the PVA matrix.