The objective of this study is to investigate the respective effects of Zn, Pb and Cd as well as the combined effect of Zn, Pb, Cd and Cu on the removal of nitrogen and oxygen demand in constructed wetlands. Four laboratory-scale gravel-filled subsurface-flow constructed wetland units planted with cattails (Typha latifolia) were operated outdoors and fed with primary-treated domestic wastewater at a constant flow rate of 25 ml/min. After 6 months, three of the wetland units were fed with the same type of wastewater spiked with Zn(II), Pb(II) and Cd(II), respectively, at 20, 5 and 1 mg/l for a further 9 months. The remaining unit was fed with the same type of wastewater spiked with a combination of Zn(II), Pb(II), Cd(II) and Cu(II) at concentrations of 10, 2.5, 0.5 and 5 mg/l, respectively, over the same period. The chemical oxygen demand (COD) and ammoniacal nitrogen (AN) concentrations were monitored at the inlet, outlet and three additional locations along the length of the wetland units to assess the performance of the wetland units at various metal loadings. At the end of the study, all cattail plants were harvested for the determination of total Kjeldahl nitrogen and metal concentrations. The results showed that the COD removal efficiency was practically independent of increasing metal loading or a combination of metal loadings during the duration of the study. In contrast, the AN removal efficiency deteriorated progressively with increasing metal loading. The relative effect of the heavy metals was found to increase in the order: Zn
Five new indole alkaloids of the ibogan type (1-5), in addition to 12 other known iboga alkaloids, were obtained from the leaf and stem-bark extract of the Malayan species Tabernaemontana corymbosa, viz., 19(S)-hydroxyibogamine (1), 19-epi-isovoacristine (2), isovoacryptine (3), 3R/S-ethoxyheyneanine (4), and 3R/S-ethoxy-19-epi-heyneanine (5). The structures were determined using NMR and MS analysis and comparison with known related compounds.
To investigate the role of serum C-reactive protein (CRP) in the diagnosis of typhoid fever, we studied 227 febrile Malaysian children hospitalized during a 12-month period. The children were: culture-positive for Salmonella typhi (Group 1; n = 108); culture-negative but with typical clinical features of typhoid fever (Group 2; n = 60); or had non-typhoidal illness (Group 3; n = 59). Group 1 children had the highest serum CRP concentrations (geometric mean [SD range]; 43 [12-150] mg/l vs. 26 [8-85] mg/l in Group 2 and 21 [4-110] mg/l in Group 3; p < 0.001). In regression analysis, age, patient group and fever duration were independently associated with serum CRP (p < 0.05) but gender was not. In Group 1 patients, there was a significant positive association between serum CRP and Widal O and H agglutinin titres. In receiver-operator characteristic (ROC) analysis of serum CRP for Groups 1 and 2 combined, compared with Group 3, the area under the curve (AUC) was 0.65. These data show that the serum CRP is highest in culture-positive children with enteric fever and reflects the immune response to the infection in this group. Nevertheless, serum CRP had relatively low sensitivity and specificity for confirmed or clinically diagnosed typhoid fever (68 and 58 per cent, respectively at 'cut-off' concentration 30.0 mg/l), and an AUC value only moderately above that associated with no predictive power (0.5). Although of limited use as a primary diagnostic test, a raised serum CRP may still have a place as one of a range of features that facilitate assessment of a febrile child in a typhoid-endemic area.
Tempoyak is a traditional Malaysian fermented condiment made from the pulp of the durian fruit (Durio zibethinus). Salt is sometime added to proceed fermentation at ambient temperature. In various samples obtained from night markets, lactic acid bacteria (LAB) were the predominant microorganisms, ranging from log 8.4 to log 9.2 cfu g(-1). No other microorganisms were present to such a level. These samples contained reduced amount of saccharose, glucose and fructose but increased amount of D- and L-lactic acid and acetic acid compared with samples of non-fermented durian fruit. Sixty-four isolates of LAB were divided into five groups by use of a few phenotypic tests. A total of 38 strains of LAB were selected for comparison by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of their whole cell protein patterns with a SDS-PAGE database of LAB. These strains were also examined for their carbohydrate fermentation patterns by use of API 50 CH. Isolates belonging to the Lactobacillus plantarum group were shown to be the predominant members of the LAB flora. In addition, isolates belonging to the Lactobacillus brevis group, Leuconostoc mesenteroides, Lactobacillus mali, Lactobacilus fermentum and an unidentified Lactobacillus sp. were also observed. A high degree of diversity among isolates belonging to the Lb. plantarum group was demonstrated by analysis of their plasmid profiles.
A total of 1,134 finger-pricked blood samples were collected from residents of Setiu, Terengganu. A drop of blood was used to make thick blood smear and about four drops were used for obtaining serum. The smears were stained and examined by the State Vector Control Unit in Kuala Terengganu, while the serum samples were tested for specific IgG4 antibodies to a novel recombinant antigen using Brugia-Elisa. Prevalence of filariasis in these areas were found to be 0.26% (3/1,134) using thick blood smear examination and 2.47% (28/1,134) using Brugia-Elisa, thus demonstrating the greater sensitivity of the latter test. In addtion, Brugia-Elisa showed a high level of specificity (97.8%, 1,106/1,131) when compared to thick blood smear examination.
The processing of amang (one of a number of tin-tailing products) for its valuable minerals has associated with the radiological and environmental problems. The processing and stockpiling of amang and ilmenite in open-air spaces, subject as it is to environmental influences, gives rise to a potential for affecting residents in adjacent area. A case study was carried out in a residential area neighbouring a typical amang plant to investigate the radiological impact to the residents. The average Effective Dose rates, calculated based on the contributions of Effective Dose rates from inhaled suspended radioactive dust, radon-thoron and their progeny, and external gamma radiation, were determined for selected houses. Results show that the occupants of those houses received Effective Dose rate, which cannot be differentiated from background. The major contributor to the average Effective Dose rate came from external radiation sources. Inhaled radon and its progeny was the second major contributor.
The application of membrane separation in palm oil refining process has potential for energy and cost savings. The conventional refining of crude palm oil results in loss of oil and a contaminated effluent. Degumming of crude palm oil by membrane technology is conducted in this study. The objective of this research is to study the feasibility of membrane filtration for the removal of phospholipids in the degumming of crude palm oil, including analyses of phosphorus content, carotene content free fatty acids (as palmitic acid), colour and volatile matter. A PCI membrane module was used which was equipped with polyethersulfone membranes having a molecular weight cut off of 9,000 (type ES209). In this study, phosphorus content was the most important parameter monitored. The membrane effectively removed phospholipids resulting in a permeate with a phosphorus content of less than 0.3 ppm The percentage removal of phosphorus was 96.4% and was considered as a good removal. Lovibond colour was reduced from 27R 50Y to 20R 30Y. The percentage removal of carotene was 15.8%. The removal of colour was considered good but the removal of carotene was considered insignificant by the membrane. Free fatty acids and volatile matter were not removed. Typical of membrane operations, the permeate flux decreased with time and must be improved in order to be adopted on an industrial scale. Membrane technology was found to have good potential in crude palm oil degumming. However, an appropriate method has to be developed to clean the membranes for reuse.
An erythromycin resistance plasmid, pAJ01 was isolated from Loctococcus lactis isolate C5 that was isolated from a healthy two-week-old chicken cecum. A 4 kb plasmid was transformed into plasmidless L. lactis MG1363 before a restriction endonuclease map was constructed. It was then fused with pUC19 to form pAJ02, which can replicate in Escherichia coli XLI-Blue as well as L. lactis MG1363. The plasmid was stably maintained in Lactococcus for more than 100 generations.
Leaf extracts of Callicarpa pentandra provided four new clerodane-type diterpenoids (1-4), of which 1, 2, and 4 have ring-A-contracted structures. Their structures and stereochemistry were established by spectral data interpretation, and for 3 also by single-crystal X-ray diffraction.
For application to the analysis of aflatoxins (AF) in commercial peanut and corn products, the ISOLUTE multimode column (IMC, solid phase multifunctional column) method was validated by comparing with the modified Florisil column (MFC) method. Twenty-two peanut and eight corn products from Malaysia and the Philippines were analysed for AFB1, AFB2, AFG1 and AFG2 firstly by the MFC method and then by the IMC method. For peanut products, 14 out of 22 samples were positive by the two methods in the range of 1-378 micrograms/kg of AF, and correlation coefficients (r) for AFB1 and AFB2 were 0.987 and 0.997, respectively. For corn and corn products, all the samples were positive in the range of 1-130 micrograms/kg, and r values were 0.992 and 0.805 for AFB1 and AFB2 respectively. Thus, the results were significantly (p < 0.01) in close agreement, particularly for lower range of 1-50 micrograms/kg of AF concentrations in all the samples. For the occurrence of AF, 11 (65%) of peanut products from Malaysia were contaminated with AF at a mean level of 50 micrograms/kg (maximum 180 micrograms/kg) and two (40% products from the Philippines were contaminated with as high as 375 micrograms/kg and 177 micrograms/kg of AF, respectively. All the corn products from the Philippines were contaminated with AF at a mean level of 44 micrograms/kg (maximum 130 micrograms/kg). Contamination of commercial foods with high levels of AF is a very important issue to both the countries since these foods are very popular among children.
This study was conducted to investigate the occurrence of antimicrobial resistance among Salmonella Weltevreden isolates from different sources in South-East Asia (Indonesia, Laos, Malaysia, Taiwan, Thailand, Vietnam), Australia, Denmark, New Zealand and the USA.
Ten new bisindole alkaloids of the vobasinyl-ibogan type, viz., conodiparines A-F (1-6), conodutarines A and B (7, 8), and cononitarines A and B (9, 10), were obtained from the leaf extract of the Malayan species Tabernaemontana corymbosa. The structures were determined using NMR and MS analysis.
Carbide sludge (10.4-11.5 tonnes day(-1)) is generated from the reaction of calcium carbide (900 kg) and water (6,000 L) in the production of acetylene (2,400 m3), in three selected acetylene manufacturing plants. The sludge (of pH 12.2 and containing Cu, Pb, Fe, Mn, Ni and Zn ions whose concentrations exceed the Department of Environment limits for industrial wastewater) was treated by vacuum filtration as a substitute for the ponding system, which is environmentally less acceptable. A similar system by flocculation was also developed. The filtration system represents an improvement over the ponding method, as shown by a pH of 7 for the clear filtrate; the solid cake, which contains 98% of the metals, can be conveniently disposed at an integrated scheduled waste treatment centre.
Partial nucleotide sequences of 1D gene of 38 isolates of foot-and-mouth disease virus (FMDV) of serotypes O, A and Asia 1 originating from various parts of India were determined. Field materials were subjected straight to RNA extraction, reverse transcription - PCR (RT-PCR) and sequencing. Also 3 FMDV vaccine strains, IND R2/75 (serotype O), IND 63/72 (serotype Asia 1) and IND 17/77 (serotype A) were included in the analysis. The seqences were compared mutually as well as with available corresponding sequences of other FMDV isolates, and their phylogenetic relationships were calculated. The deduced amino acid sequences showed that the serotype O isolates were relatively conserved as compared to serotype Asia 1 or A isolates from India. In phylogenetic analysis, the serotype O viruses clustered in two genotypes, one including the European vaccine strain (O1/K) and the other represented by the isolates from Bangladesh, India, Nepal and Turkey. The serotype Asia 1 viruses clustered in two groups of single genotype where the prototype strain from Pakistan (PAK 1/54) formed one group and the other was formed by the isolates from Bangladesh, Bhutan, India, Israel and Nepal. In serotype A viruses three well-differentiated genotypes were observed. The isolates from Azerbaijan, Bangladesh, Malaysia and India formed the first genotype. The second genotype was formed by isolates from Iran, Saudi Arabia and Turkey, while two recent Iranian isolates represented the third genotype. In India, the prevalence of at least one genotype could be identified in each serotype. This evolutionary clustering of isolates from the neighbor countries is not surprising, since these countries share border with India. The genetic relatedness between sequences of isolates from India and those from distant places is indicative of spread of the virus between the countries. Of importance is the fact that clinical materials proved useful for rapid generation of sequences and subsequent studying of molecular epidemiology of the disease.
School children from 3 primary and 2 secondary schools in Sarawak were examined for the presence of gastrointestinal helminths. One primary school and 1 secondary school were located in a town (Serian), the other primary and secondary schools were in the countryside outside Serian. The intestinal helminths detected were Ascaris lumbricoides, Trichuris trichiura, Enterobius vermicularis and hookworm. Children from the rural schools had higher numbers of eggs in their faeces than those from the Serian schools. Children from the rural primary schools had higher number of eggs than those from the rural secondary school. The prevalence of Ascaris, Trichuris and hookworms in male and female and in primary and secondary school children was recorded.
The present study investigated whether people working closely with animals were at higher risk of getting infected with Blastocystis hominis. The prevalence of the parasite was determined in two population groups, i.e., animal handlers and normal healthy individuals who did not work with animals. In all, 105 stool samples were collected from animal handlers from 2 local research institutions, a local zoo, and a local abattoir and 163 stool samples were collected from normal healthy individuals residing in high-rise flats in the city. The in vitro culture method used in the study detected that 41% of 105 animal handlers and 17% of 163 flat-dwellers in the city were positive for Blastocystis. This statistically significant finding (P = 0.0000313) shows that people who work closely with animals do stand at risk of acquiring Blastocystis infection.