Identification of Pelargonium radula as bioindicator for mercury (Hg) detection confers a new hope for monitoring the safety of drinking water consumption. Hg, like other non-essential metals, inflicts the deterioration of biological functions in human and other creatures. In the present study, effects of Hg on the physiology and biochemical content of P. radula were undertaken to understand the occurrence of the morphological changes observed. Young leaves of P. radula were treated with different concentrations of Hg-containing solution (0.5, 1.0 and 2.0 ppb) along with controls for 4 h, prior to further analysis. Elevated Hg concentration in treatment solution significantly prompted an increased accumulation of Hg in the leaf tissues. Meanwhile, total protein, chlorophyll and low molecular mass thiol contents (cysteine, glutathione and oxidized glutathione) decreased as Hg accumulation increased. However, phytochelatin 2 productions were induced in the treated leaves, in comparison to the control. Based on these findings, it is postulated that as low as 0.5 ppb of Hg interferes with the metabolic processes of plant cells, which was reflected from the morphological changes exhibited on P. radula leaves-the colour of the Hg-treated leaves changed from green to yellowish-brown, became chlorosis and wilted. Changes in the tested characteristics of plant are closely related to the Hg-induced morphological changes on P. radula leaves, a potential bioindicator for detecting Hg in drinking water.
High-quality fish oil for human consumption requires low levels of toxic elements. The aim of this study was to compare different oil extraction methods to identify the most efficient method for extracting fish oil of high quality with the least contamination. The methods used in this study were Soxhlet extraction, enzymatic extraction, wet reduction, and supercritical fluid extraction. The results showed that toxic elements in fish oil could be reduced using supercritical CO2 at a modest temperature (60°C) and pressure (35 MPa) with little reduction in the oil yield. There were significant reductions in mercury (85 to 100%), cadmium (97 to 100%), and lead (100%) content of the fish oil extracted using the supercritical fluid extraction method. The fish oil extracted using conventional methods contained toxic elements at levels much higher than the accepted limits of 0.1 μg/g.
Extraction of protease from a local ginger rhizome (Zingiber officinale var. Bentong) was carried out. The effect of extraction pH (6.4, 6.8, 7.0, 7.2, 7.6, 8.0, 8.4, and 8.8) and stabilizers (0.2% ascorbic acid, 0.2% ascorbic acid and 5 mM EDTA, or 10 mM cysteine and 5 mM EDTA) on protease activity during extraction was examined. pH 7.0 potassium phosphate buffer and 10 mM cysteine in combination with 5 mM EDTA as stabilizer were found to be the most effective conditions. The extraction procedure yielded 0.73% of Bentong ginger protease (BGP) with a specific activity of 24.8±0.2 U/mg protein. Inhibitory tests with some protease inhibitors classified the enzyme as a cysteine protease. The protease showed optimum activity at 60 °C and pH 6-8, respectively. The enzyme was completely inhibited by heavy metal cations such as Cu2+, and Hg2+. SDS stimulated the activity of enzyme, while emulsifiers (Tween 80 and Tween 20) slightly reduced its activity. The kinetic analysis showed that the protease has Km and Vmax values of 0.21 mg mL-1 and 34.48 mg mL-1 min-1, respectively. The dried enzyme retained its activity for 22 months when stored at -20 °C.
This study aims to optimise the operating conditions for the supercritical fluid extraction (SFE) of toxic elements from fish oil. The SFE operating parameters of pressure, temperature, CO2 flow rate and extraction time were optimised using a central composite design (CCD) of response surface methodology (RSM). High coefficients of determination (R²) (0.897-0.988) for the predicted response surface models confirmed a satisfactory adjustment of the polynomial regression models with the operation conditions. The results showed that the linear and quadratic terms of pressure and temperature were the most significant (p < 0.05) variables affecting the overall responses. The optimum conditions for the simultaneous elimination of toxic elements comprised a pressure of 61 MPa, a temperature of 39.8ºC, a CO₂ flow rate of 3.7 ml min⁻¹ and an extraction time of 4 h. These optimised SFE conditions were able to produce fish oil with the contents of lead, cadmium, arsenic and mercury reduced by up to 98.3%, 96.1%, 94.9% and 93.7%, respectively. The fish oil extracted under the optimised SFE operating conditions was of good quality in terms of its fatty acid constituents.
A new lead(II) electrode has been constructed with poly(hydroxamic acid) (PHXA) as the active material and silicone rubber as the supporting material. The electrode gave near Nerstian response over the concentration range 4 x 10(-5)-1 x 10(-2)M lead(II). The detection limit of the electrode is approximately 4 x 10(-6)M and the electrode works well in the pH range 4.5-6.0. The response time was 50-120 sec over the whole concentration range and the electrode has a working life of at least 4 weeks. Iron(III) severely poisoned the electrode membrane. Nickel(II) and mercury(II) gave very strong interference compared to copper(II), silver(I), cobalt(II), sodium(I), potassium(I), zinc(II) and cadmium(II) which gave some or little interference. Values determined with atomic absorption (AAS) and a commercial lead(II) electrode were in good agreement with those measured with the lead(II) electrode reported here.
Bacterial isolates from 30 farmed bullfrogs (Lithobates catesbeianus) weighing 500-600 g at Johore, Malaysia with external clinical signs of ulcer, red leg and torticollis were tested for their antibiograms and heavy metal tolerance patterns. A total of 17 bacterial species with 77 strains were successfully isolated and assigned to 21 antibiotics and 4 types of heavy metal (Hg(2+), Cr(6+), Cd(2+), Cu(2+)). Results revealed that bacteria were resistant against lincomycin (92%), oleandomycin (72.7%) and furazolidone (71.4%) while being susceptible to chloramphenicol and florfenicol at 97.4%. The multiple antibiotic resistance (MAR) index for C. freundii, E. coli and M. morganii was high with the value up to 0.71. Bacterial strains were found to exhibit 100 % resistance to chromium and mercury. High correlation of resistance against both antibiotics and heavy metals was found (71.4 to 100%) between bullfrog bacteria isolates, except bacteria that were resistant to kanamycin showed only 25% resistance against Cu(2+). Based on the results in this study, bacterial pathogens of bullfrog culture in Johore, Malaysia, were highly resistant to both antibiotics and heavy metals.
Background: In Malaysia, the prevalence of hypertension amongst adults aged 30 years and above has increased from 32.9% in 1996 to 40.5% in 2004 and to 42.6% in 2006. Information on the prevalence of hypertension among adolescents is lacking.
Objective: to determine the prevalence of hypertension among Malay secondary school students in Putrajaya.
Methods: A cross sectional study was carried out in Putrajaya, Malaysia. The sampling frame consisted of a list of all the 12 secondary schools in Putrajaya. Three schools were selected using table of random numbers. All Malay students aged 13 years old to 17 years old from the three selected school students were included in the study. Blood pressure was measured after the respondents had rested for at least 5 minutes using a standard mercury sphygmomanometer. Three blood pressure measurements were taken for each respondent. Systolic blood pressure [SBP] was defined as the average of three SBP readings and diastolic blood pressure [DBP] was defined as the average of three DBP readings. Data was analyzed using SPSS 18.
Results: The overall mean SBP and DBP were 108.9 mmHg and 63.2 mmHg respectively. The prevalence of pre-hypertension and hypertension among the male was 16.2% and 12.9% respectively as compared to 5.8% and 10.2% respectively in the females. The overall prevalence of prehypertension and hypertension was 11.1% and 11.6% respectively. The prevalence increased with age (p<0.05). There was a significant positive correlation between BMI and SBP (r = 0.52, r2 = 0.27, p= 0.001) and BMI and DBP (r = 0.38, r2 = 0.15, p= 0.001). The mean SBP was significantly higher in males (111.7 mmHg) as compared to 106 mmHg in females (p<0.001). The mean DBP in males (63.5 mmHg) was slightly higher as compared to 62.9 mmHg in females but the difference was not significant.
Conclusions: Prevalence of hypertension and pre-hypertension is high. There is an urgent need for implementation of a comprehensive CVD prevention program and routine blood pressure measurements should be taken in school children to improve the detection, prevention and treatment of hypertension
Keywords: Prevalence, Hypertension, Adolescents, Putrajaya, Malaysia
Traditionally, in Chinese medicine, tree peony and apple flower buds are used to prepare herbal decoctions to cure various ailments. As both of these flowers are popular and used regularly, providing scientific evidence on their basic composition is a necessity. Hence, in the present study, we report the chemical composition of these two flower buds. Results revealed tree peony and apple flower buds to have high crude protein (15.73 and 26.30%), fibre (13.11 and 16.51%), and carbohydrate (57.84 and 40.63%) contents. Both the flowers had significant amounts of essential amino acids and unsaturated fatty acids. Essential minerals present in tree peony and apple flowers were potassium (1540.37 and 1125.60 mg/100 g), calcium (462.46 and 449.98 mg/100 g), magnesium (241.51 and 164.23 mg/100 g), sodium (12.75 and 20.06 mg/100 g), and phosphorus (420.00 and 590.00 mg/100 g), respectively. Heavy metals (cadmium, nickel, mercury, lead, and arsenic) were detected in trace amounts (< 0.50 mg/100 g) in both the flower buds. Results obtained indicate that both flowers could be exploited as an additional source of nutraceutical for the development of new functional foods.
Dentistry is highly energy and resource intensive with significant environmental impact. Factors inherent in the profession such as enormous electricity demands of electronic dental equipment, voluminous water requirements, environmental effects of biomaterials (before, during and after clinical use), the use of radiation and the generation of hazardous waste involving mercury, lead etc have contributed towards this. With rising temperatures across the world due to global warming, efforts are being made worldwide to mitigate the effects of environmental damage by resorting to sustainability concepts and green solutions in a myriad of ways. In such a scenario, a professional obligation and social responsibility of dentists makes it imperative to transform the practice of dentistry from a hazardous to a sustainable one, by adopting environmental-friendly measures or 'green dentistry'. The NHS in the UK has been proactive in implementing sustainability in healthcare by setting targets, developing guidance papers, initiating steering groups to develop measures and implementing actions through its Sustainable Development Unit (SDU). Such sustainable frameworks, specific to dentistry, are not yet available and even the scientific literature is devoid of studies in this field although anecdotal narratives abound. Hence this paper attempts to present a comprehensive evaluation of the existing healthcare sustainability principles, for their parallel application in the field of dentistry and lays out a blueprint for integrating the two main underlying principles of sustainability - resource use efficiency and eliminating or minimising pollution - in the day-to-day practice. The article also highlights the importance of social values, community care, engaging stakeholders, economic benefits, developing policy and providing leadership in converting the concept of green dentistry into a practised reality.
The volume of contaminated rivers in Malaysia continues to keep rising through the years. The
cost of instrumental monitoring is uneconomical and prohibits schedule monitoring of
contaminants particularly heavy metals. In this work, a rapid enzyme assay utilizing the
molybdenum-reducing enzyme as an inhibitive assay, prepared in crude form from the
molybdenum-reducing bacterium Serratia sp. strain DRY5 has been developed for monitoring
the heavy metals mercury, silver, copper and chromium in contaminated waters in the Juru
Industrial Estate. The crude enzyme extract transformed soluble molybdenum
(phosphomolybdate) into a deep blue solution, which is inhibited by heavy metals such as
mercury, silver, copper and chromium. The IC50 and Limits of Detection (LOD) values for
mercury, copper, silver and cadmium were 0.245, 0.298, 0.367, 0.326, and 0.124, 0.086, 0.088
and 0.094 mg L-1, respectively. The assay is rapid, and can be carried out in less than 10 minutes.
In addition, the assay can be carried out at ambient temperature. The IC50 values for these heavy
metals are more sensitive than several established assays. Water samples from various locations
in the month of November from the Juru Industrial Estate (Penang) were tested for the presence
of heavy metals using the developed assay. Enzyme activity was nearly inhibited for water
samples from several locations. The presence of heavy metals was confirmed instrumentally
using Atomic Emission Spectrometry and a Flow Injection Mercury System. The assay is rapid
and simple and can be used as a first screening method for large scale monitoring of heavy
metals.
The indiscriminate released of heavy metals and xenobiotics into soils and aquatic bodies
severely alter soil organisms and the ecosystem. The isolation of xenobiotics degrading
microorganisms is cost-effective and naturally pleasant approach. Lately, the toxicological effect
of molybdenum to the spermatogenesis of several organisms has been record. This present study
is aimed at the isolation and characterization of a bacterium capable of converting molybdenum
to the colloidal molybdenum blue. Bacteria characterization was performed in a microplate
format using resting cells. Thus, the reduction process can be employed as a device for
molybdenum bioremediation. The results of the study revealed an optimum reduction at pH
between 6.0 and 6.3 and temperatures of between 25 and 40 oC. Similarly, it was also observed
that a phosphate concentration not greater than 5.0 mM and a sodium molybdate concentration
at 20 mM was required for reduction. Glucose was observed as the best carbon source to support
reduction. Following the scanning of molybdenum blue, it revealed an absorption spectrum
indicating the characteristics of molybdenum blue as a reduced phosphomolybdate. Molybdenum
reduction is inhibited by heavy metals like silver, lead, arsenic and mercury. Furthermore, the
ability of the bacterium (Pseudomonas sp. strain Dr.Y Kertih) to utilize several organic
xenobiotics such as phenol, acrylamide, nicotinamide, acetamide, iodoacetamide, propionamide,
acetamide, sodium dodecyl sulfate (SDS) and diesel as electron donor sources for aiding
reduction or as carbon sources for growth was also examined. Finding showed that none was
capable of aiding molybdenum reduction, however the bacterium was capable of growing on both
diesel and phenol as carbon sources. GC analysis was used to confirmed diesel degradation.
The industrial contamination of marine sediments with mercury, silver, and zinc in Penang, Malaysia was studied with bio-remediation coupled with power generation using membrane less open (aerated) and closed (non-aerated) sediment microbial fuel cells (SMFCs). The prototype for this SMFC is very similar to a natural aquatic environment because it is not stimulated externally and an oxygen sparger is inserted in the cathode chamber to create the aerobic environment in the open SMFC and no oxygen supplied in the closed SMFC. The open and closed SMFCs were showed the maximum voltage generation 300.5 mV (77.75 mW/m2) and 202.7 mV (45.04 (mW/m2), respectively. The cyclic voltammetry showed the oxidation peak in open SMFCs at +1.9 μA and reduction peak at -0.3 μA but in closed SMFCs oxidation and reduction peaks were noted at +1.5 μA and -1.0 μA, respectively. The overall impedance (anode, cathode and solution) of closed SMFCs was higher than open SMFCs. The charge transfer impedance showed that the rates of substrate oxidation and reduction were very low in the closed SMFCs than open SMFCs. The Nyquist arc indicated that O2 act as electron acceptor in the open SMFCs and CO2 in the closed SMFCs. The highest remediation efficiency of toxic metals [Hg (II) ions, Zn (II) ions, and Ag (I) ions] in the open SMFCs were 95.03%, 86.69%, and 83.65% in closed SMFCs were 69.53%, 66.57%, and 65.33%, respectively, observed during 60-80 days. The scanning electron microscope and 16S rRNA analysis showed diverse exoelectrogenic community in the open SMFCs and closed SMFCs. The results demonstrated that open SMFCs could be employed for the power generation and bioremediation of pollutants.
In this study, three popular, regionally grown rice varieties (Bario, brown and white) were compared with three of the most popular and highly marketed imported rice varieties (black, glutinous and basmati rice) in Penang region of Malaysia. Rice samples were evaluated for amino acids, fatty acids, minerals, heavy metals and dietary fiber composition. Overall, amino acids content among all the rice samples were comparable to each other. Results with regard to minerals showed potassium to be high in brown rice (197.41 mg/100g), while magnesium was recorded to be high in black rice (107.21 mg/100g). Heavy metals such as cadmium, nickel, mercury and lead, though present, they were in negligible amounts. Among all the rice varieties investigated, the total saturated fatty acid and unsaturated fatty acid content was highest in black rice (5.89%). The soluble dietary fiber was higher in white rice (16.39%), whereas insoluble dietary fiber was high in brown (16.51%) and black rice (14.49%), respectively. Results generated from this study is anticipated to benefit both the health wary consumers (based on their potential nutritional attributes) as well as the local food industries to choose the best rice variety while developing novel rice based food products.
A facile electrochemical sandwich immunosensor for the detection of a breast cancer biomarker, the human epidermal growth factor receptor 2 (HER2), was designed, using lead sulfide quantum dots-conjugated secondary HER2 antibody (Ab2-PbS QDs) as a label. Using Ab2-PbS QDs in the development of electrochemical immunoassays leads to many advantages such as straightforward synthesis and well-defined stripping signal of Pb(II) through acid dissolution, which in turn yields better sensing performance for the sandwiched immunosensor. In the bioconjugation of PbS QDs, the available amine and hydroxyl groups from secondary anti-HER2 and capped PbS QDs were bound covalently together via carbonyldiimidazole (CDI) acting as a linker. In order to quantify the biomarker, SWV signal was obtained, where the Pb2+ ions after acid dissolution in HCl was detected. The plated mercury film SPCE was also detected in situ. Under optimal conditions, HER2 was detected in a linear range from 1-100 ng/mL with a limit of detection of 0.28 ng/mL. The measures of satisfactory recoveries were 91.3% to 104.3% for the spiked samples, displaying high selectivity. Therefore, this method can be applied to determine HER2 in human serum.