Isolates of Vibrio cholerae O1 El Tor from two well-defined cholera outbreaks in Malaysia were analyzed by using pulsed-field gel electrophoresis (PFGE). Isolates from sporadic cases occurring during the same time period were also studied. Digestion of chromosomal DNA from these isolates of V. cholerae O1 with restriction endonucleases NotI (5'-GCGGCCGC-3') and SfiI (5'-GGCCNNNN-3'), followed by PFGE, produced restriction endonuclease analysis (REA) patterns consisting of 13 to 24 bands (ranging in size from 46 to 398 kbp). Analysis of the REA patterns generated by PFGE after digestion with NotI and SfiI suggested the clonal nature and close genetic identity of the isolates obtained during each of the two outbreaks (Dice coefficient, 0.93 to 1.0). Although they had very similar REA patterns, the two outbreak clones were not identical. Isolates of V. cholerae O1 from sporadic cases, on the other hand, appeared to be much more heterogeneous (five different REA patterns detected in the five isolates tested; Dice coefficient, 0.31 to 0.81) than those obtained during the two outbreaks. We conclude that PFGE of V. cholerae O1 chromosomal DNA digested with infrequently cutting restriction endonucleases is a useful method for molecular typing of V. cholerae isolates for epidemiological purposes.
The relationship between left ventricular mass (LVM) and the mean arterial blood pressure (MAP) was investigated, using M-Mode echocardiography. MAP was higher in hypertensive patients (p<0.05, n=9) compared to that of controlled subjects. The results showed that LVM index for hypertensive patients was significantly higher (p<0.05, n=9) than that for the normal group. LVM index correlates fairly (r=0.6) with MAP for hypertensive patients. The results also show that the increase of intraventricular septal wall thickness (IVST) was due to hypertension. The LVM (r =0.9) and IVST (r=0.75) of the normal subjects were linearly dependent on the body surface area (BSA). The hypertensive group revealed a non-linear relationship to the BSA.
An IgM dot-immunobinding assay (IgM-DIA) was developed for the diagnosis of scrub typhus infection. The whole cell antigens of Karp, Kato and Gilliam strains of Rickettsia tsutsugamushi were immobilized onto nitrocellulose paper and reacted with patients sera. The presence of IgM R. tsutsugamushi specific antibody in the patient sera could be detected by the observation of a visible brown dot on the nitrocellulose paper. The IgM-DIA has a sensitivity of 90.4% and specificity of 81.4% as compared to the indirect immunoperoxidase test. The IgM-DIA is rapid, simple, cost-effective, does not require microscope or incubator. It is recommended as a rapid screening test for the diagnosis of scrub typhus infection in the field or rural area within the hyperendemic region.
Bio-composites are easy to manufacture and environmentally friendly, could reduce the overall cost and provide lightweight due to the low density of the natural fibers. In a bid to compete with the synthetic fiber reinforced composites, a single natural fiber composite may not be a good choice to obtain optimal properties. Hence, hybrid composites are produced by adding two or more natural fibers together to obtain improved properties, such as mechanical, physical, thermal, water absorption, acoustic and dynamic, among others. Regarding thermal stability, the composites showed a significant change by varying the individual fiber compositions, fiber surface treatments, addition of fillers and coupling agents. The glass transition temperature and melting point obtained from the thermomechanical analysis and differential scanning calorimetry are not the same values for several hybrid composites, since the volume variation was not always parallel with the enthalpy change. However, the difference between the temperature calculated from the thermomechanical analysis and differential scanning calorimetry was lower. Significantly, this critical reviewed study has a potential of guiding all composite designers, manufacturers and users on right selection of composite materials for thermal applications, such as engine components (covers), heat shields and brake ducts, among others.
The present work investigated the impact of several juice extraction methods (blender,
centrifugal juicer, and slow juicer) and thermal pasteurisation (72°C, 15 s) on the different
properties [physicochemical, polyphenol oxidase (PPO) activity, and functional] of
Clinacanthus nutans juice mix during storage (28 d, 4°C). Regardless of juicing technique, all
juices had similar colour and antioxidants [tested using 2,2-diphenyl-1-picrylhydrazyl
(DPPH) and ferric reducing antioxidant power (FRAP) methods]. The juices also had similar
PPO activity and sensory acceptance in terms of colour, aroma, flavour, mouthfeel, and
overall acceptability. The blender yielded juice with higher pH, soluble solids, and relative
viscosity than other methods. The slow juicer was the best at retaining ascorbic acid (39.33 ±
3.06 mg/100 mL), while the blender was best at retaining phenolic compounds (11.82 ± 0.12
mg gallic acid equivalents/100 mL) and chlorophyll (6.95 ± 0.31 μg/mL). Pasteurisation
negatively affected the colour, functional properties, and sensory characteristics (colour,
aroma, flavour, and mouthfeel) of the juice.
Greywater is one of the most important alternative sources for irrigation in arid and semi-arid countries. However, the health risk associated with the microbial contents of these waters limits their utilization. Many techniques have been developed and used to generate a high microbiological quality of greywater. The main problem in the treatment of greywater lies in the nature of pathogenic bacteria in terms of their ability to survive during/after the treatment process. The present review focused on the health risk associated with the presence of pathogenic bacteria in greywater and the treatment technologies used for the disinfection processes.
Aedes aegypti is a principal vector responsible for the transmission of dengue viruses (DENV). To date, vector control remains the key option for dengue disease management. To develop new vector control strategies, a more comprehensive understanding of the biological interactions between DENV and Ae. aegypti is required. In this study, a cDNA library derived from the midgut of female adult Ae. aegypti was used in yeast two-hybrid (Y2H) screenings against DENV2 envelope (E) protein. Among the many interacting proteins identified, carboxypeptidase B1 (CPB1) was selected, and its biological interaction with E protein in Ae. aegypti primary midgut cells was further validated. Our double immunofluorescent assay showed that CPB1-E interaction occurred in the endoplasmic reticulum (ER) of the Ae. aegypti primary midgut cells. Overexpression of CPB1 in mosquito cells resulted in intracellular DENV2 genomic RNA or virus particle accumulation, with a lower amount of virus release. Therefore, we postulated that in Ae. aegypti midgut cells, CPB1 binds to the E protein deposited on the ER intraluminal membranes and inhibits DENV2 RNA encapsulation, thus inhibiting budding from the ER, and may interfere with immature virus transportation to the trans-Golgi network.
A method for improving the thermoluminescence (TL) yield of silica-based optical fibres is demonstrated. Using silica obtained from a single manufacturer, three forms of pure (undoped) fibre (capillary-, flat-, and photonic crystal fibre (PCF)) and two forms of Ge-doped fibre (capillary- and flat-fibre) were fabricated. The pure fibre samples were exposed to 6 and 21MeV electrons, the doped fibres to 6MV photons. The consistent observation of large TL yield enhancement is strongly suggestive of surface-strain defects generation. For 6MeV irradiations of flat-fibre and PCF, respective TL yields per unit mass of about 12.0 and 17.5 times that of the undoped capillary-fibre have been observed. Similarly, by making a Ge-doped capillary-fibre into flat-fibre, the TL response is found to increase by some 6.0 times. Thus, in addition to TL from the presence of a dopant, the increase in fused surface areas of flat-fibres and PCF is seen to be a further important source of TL. The glow-curves of the undoped fibres have been analysed by computational deconvolution. Trap centre energies have been estimated and compared for the various fibre samples. Two trap centre types observed in capillary-fibre are also observed in flat-fibre and PCF. An additional trap centre in flat-fibre and one further trap centre in PCF are observed when compared to capillary fibre. These elevated-energy trap centres are linked with strain-generated defects in the collapsed regions of the flat fibre and PCF.
Dengue fever (DF) is a major vector-borne disease in Malaysia. The incidences of DF in Malaysia are caused by viruses transmitted through the bites of infected female Aedes albopictus and Ae. aegypti mosquitoes. This study aims to establish the spatial density of mosquito population or breteau index (BI) in the areas of Kuala Lumpur using geographic information system (GIS), remote sensing (RS) and spatial statistical tools.
The WHO adult susceptibility test is in use for insecticide resistance monitoring. Presently, materials are being imported from the Universiti Sains Malaysia, Malaysia and sometimes it is cost prohibitive. As an alternative, we present here a method of bottle bioassay using indigenous material. Different aspects related to the assay were studied and validated in the field. Bottle assay was standardized in the laboratory by using locally sourced material and laboratory-maintained insecticide-susceptible Anopheles stephensi and Aedes aegypti strains against technical grade deltamethrin and cyfluthrin insecticides dissolved in ethanol in a range of different concentrations. The frequency of use of the deltamethrin-coated bottles and shelf-life were determined. Discriminating dose for deltamethrin and cyfluthrin was 10 μg against An. stephensi and 2 μg against Ae. aegypti females. Insecticide-coated bottles stored at 25 to 35 °C can be used for three exposures within 7 days of coating. The study carried out in the laboratory was validated on wild caught An. culicifacies in the states of Odisha and Chhattisgarh against deltamethrin-coated bottles in comparison to WHO adult susceptibility test. Results of the study indicated that deltamethrin-coated bottles were effective up to three exposures within 7 days of coating for field population and 100% mortality was recorded within 35 min as observed in laboratory studies for field collected susceptible population. Also in the WHO adult susceptibility test, 100% knock-down within 35 min and 100% mortality after 24 h holding period were observed in susceptible population, while in it was 50% knock-down in 1 h and 64% mortality after 24 h holding period for resistant population (50% mortality in bottle assay in 60 min). The bottle assay can be used as an alternative to the WHO adult susceptibility test both in the laboratory and field for monitoring insecticide resistance in mosquito vectors using locally sourced material.
Soil-to-plant transfer factors (TFs) are of fundamental importance in assessing the environmental impact due to the presence of radioactivity in soil and agricultural crops. Tapioca and sweet potato, both root crops, are popular foodstuffs for a significant fraction of the Malaysian population, and result in intake of radionuclides. For the natural field conditions experienced in production of these foodstuffs, TFs and the annual effective dose were evaluated for the natural radionuclides (226)Ra, (232)Th, (40)K, and for the anthropogenic radionuclide (88)Y, the latter being a component of fallout. An experimental tapioca field was developed for study of the time dependence of plant uptake. For soil samples from all study locations other than the experimental field, it has been shown that these contain the artificial radionuclide (88)Y, although the uptake of (88)Y has only been observed in the roots of the plant Manihot esculenta (from which tapioca is derived) grown in mining soil. The estimated TFs for (226)Ra and (232)Th for tapioca and sweet potato are very much higher than that reported by the IAEA. For all study areas, the annual effective dose from ingestion of tapioca and sweet potato are estimated to be lower than the world average (290 μSv y(-1)).
Current study concerns measurement of radioactivity levels in areas surrounding a 2420 MW thermal power plant fueled predominantly by bituminous coal. The concentrations of (226)Ra, (232)Th and (40)K in onsite bottom-ash were found to be 139 Bq/kg, 108 Bq/kg and 291 Bq/kg, respectively, the levels for these radiolnuclides in soil decreasing with distance from the power plant. At the plant perimeter the respective radionuclide concentrations were 87 Bq/kg, 74 Bq/kg and 297 Bq/kg. In a nearby town, the corresponding concentrations were 104 Bq/kg, 52 Bq/kg and 358 Bq/kg, suggestive of use of TENORM affected soils. The mean radium equivalent activities (Raeq) in soil and ash sample in the town were 205 Bq/kg and 316 Bq/kg, respectively. The Kapar plant ash/slag appears to contain a higher level of TENORM than the world average. The degree of contamination is much higher inside the town where slag has been mixed with topsoil as landfill or as simple domestic waste. For the prevailing levels of exposure and a worst case senario, the predicted committed effective dose due to ingestion and inhalation for intake durations of 1- and 30 years would be 4.2 μSv and 220 μSv, respectively.
We constructed a novel chicken (Gallus gallus) lung cDNA library fused inside yeast acting domain vector (pGADT7). Using yeast two-hybrid screening with highly pathogenic avian influenza (HPAI) nucleoprotein (NP) from the strain (A/chicken/Malaysia/5858/2004(H5N1)) as bait, and the Gallus gallus lung cDNA library as prey, a novel interaction between the Gallus gallus cellular RNA export adaptor protein Aly/REF and the viral NP was identified. This interaction was confirmed and validated with mammalian two hybrid studies and co-immunoprecipitation assay. Cellular localization studies using confocal microscopy showed that NP and Aly/REF co-localize primarily in the nucleus. Further investigations by mammalian two hybrid studies into the binding of NP of other subtypes of influenza virus such as the swine A/New Jersey/1976/H1N1 and pandemic A/Malaysia/854/2009(H1N1) to human Aly/REF, also showed that the NP of these viruses interacts with human Aly/REF. Our findings are also supported by docking studies which showed tight and favorable binding between H5N1 NP and human Aly/REF, using crystal structures from Protein Data Bank. siRNA knockdown of Aly/REF had little effect on the export of HPAI NP and other viral RNA as it showed no significant reduction in virus titer. However, UAP56, another component of the TREX complex, which recruits Aly/REF to mRNA was found to interact even better with H5N1 NP through molecular docking studies. Both these proteins also co-localizes in the nucleus at early infection similar to Aly/REF. Intriguingly, knockdown of UAP56 in A549 infected cells shows significant reduction in viral titer (close to 10 fold reduction). Conclusively, our study have opened new avenues for research of other cellular RNA export adaptors crucial in aiding viral RNA export such as the SRSF3, 9G8 and ASF/SF2 that may play role in influenza virus RNA nucleocytoplasmic transport.
Deficiencies in knowledge about immunization among parents often leads to poor utake or errors in immunization dosage and timing. The aims of this study were to determine Iraqi parents' views of barriers to immunization and beliefs about ways to promote immunization. A questionnaire survey was carried out among 528 Iraqi parents with children who had incomplete immunization status. The main barriers to immunization agreed by the parents were lack of vaccine availability (51.5% of parents) and parents' lack of education (42.4%), while 88.4% of parents thought that lack of funding was not an important barrier. More than 60% of the parents suggested promoting childhood immunization via the media, and 77.5% thought that an increase in funding would not remove barriers to childhood immunization. Better vaccine availability in public health clinics and improving parents' literacy might enhance immunization uptake in Iraq.
The presence of natural radioactivity and (137)Cs has been investigated in fresh media obtained from South China Sea locations off the coast of peninsular Malaysia. The media include seafood, sea water and sediment. The samples were collected some weeks prior to the devastating 2011 Tōhoku earthquake and associated tsunami, the occurrence of which precipitated the Fukushima incident. All samples showed the presence of naturally occurring (226)Ra, (228)Ra and primordial (40)K, all at typically prevailing levels. The concentrations of natural radioactivity in molluscs were found to be greater than that of other marine life studied herein, the total activity ranging from 337 to 393 Bq kg(-1) dry weight. The total activity in sea water ranged from 15 to 88 Bq l(-1). Sediment samples obtained at deep sea locations more than 20 km offshore further revealed the presence of (137)Cs. The activity of (137)Cs varied from ND to 0.5 Bq kg(-1) dry weight, the activity increasing with offshore distance and depth. The activity concentrations presented herein should be considered useful in assessing the impact of any future radiological contamination to the marine environment.
Phytochemical investigation on the stem bark of Shorea maxwelliana yielded five oligostilbenoids identified as α-viniferin (1), maximol A (2), vaticanol A (3), suffruticosol A (4) and vaticanol G (5). Chemotaxonomy of isolated compounds was discussed briefly. Major compounds were tested for neurotoxic and cytotoxic activities. Neurotoxicity for all tested compounds did not pose any toxic effect against cultured cell (cell viability range ±100-94%). Compounds 2-5 possessed active cyctotoxic activity against HL60 cell line with IC50 values range of 2.7-78 µg mL(-1).
The best management of asymptomatic carotid artery disease in patient who needs coronary bypass remains controversial. We report the neurological outcome of four patients with asymptomatic unilateral significant carotid artery disease who underwent conventional coronary bypass without carotid revascularization. Our review highlighted the risk of perioperative stroke is not increased despite carotid revascularization was not performed. Asymptomatic carotid artery disease is not the cause for cerebral infarct but soft aortic atheroma encountered during surgery is the main culprit.
Highly-pathogenic avian influenza (HPAI) H5N1 and Newcastle disease (ND) viruses are the two most important poultry viruses in the world, with the ability to cause classic central nervous system dysfunction in poultry and migratory birds. To elucidate the mechanisms of neurovirulence caused by these viruses, a preliminary study was design to analyze host's cellular responses during infections of these viruses.
To identify the immunization providers' characteristics associated with immunization rate in children younger than 2 years. A cohort and a cluster sampling design were implemented; 528 children between 18 and 70 months of age were sampled in five public health clinics in Mosul-Iraq. Providers' characterizations were obtained. Immunization rate for the children was assessed. Risk factors for partial immunization were explored using both bivariate analyses and multi-level logistic regression models. Less than half of the children had one or more than one missed dose, considered as partial immunization cases. The study found significant association of immunization rate with provider's type. Two factors were found that strongly impacted on immunization rate in the presence of other factors: birthplace and immunization providers' type.
Cholangiocarcinoma (CCA) is a rare biliary tract epithelial malignancy. We described the clinical features of CCA patients in our institution. A 10-year retrospective study of patients with cholangiocarcinoma in University Malaya Medical Centre was conducted. Clinical data and outcomes in relation to the three anatomical groups of CCA were collected and analysed. Of the 69 patients that were included 55% were male. Mean age was 61 years. Twelve (17%) had intrahepatic, 38 (55%) perihilar and 19 (28%) distal tumour. Mean age (p=0.043), median duration of symptoms (p=0.011), jaundice (p<0.001), total bilirubin level (p=0.003), INR (p=0.005) and mean tumour size (p=0.048) were significantly related to the site of tumour. Only 12 patients had curative resection with seven R0 resections. Cholangiocarcinoma is increasingly diagnosed in our population. Despite that, the diagnosis is still often late. Age, jaundice and tumour size may predict anatomical location of CCA.