Showing papers by "University of Malaya published in 1994"

Epidemiologic analysis of sporadic Salmonella typhi isolates and those from outbreaks by pulsed-field gel electrophoresis.

Abstract: Pulsed-field gel electrophoresis (PFGE) was used to compare and analyze 158 isolates of Salmonella typhi from five well-defined outbreaks of typhoid fever in Malaysia and also isolates involved in sporadic cases of typhoid fever occurring during the same period. Digestion of chromosomal DNAs from these S. typhi isolates with the restriction endonucleases XbaI (5'-TCTAGA-3'), SpeI (5'-ACTAGT-3'), and AvrII (5'-CCTAGG-3') and then PFGE produced restriction endonuclease analysis (REA) patterns consisting of 11 to 24 DNA fragments ranging in size from 20 to 630 kbp. Analysis of the REA patterns generated by PFGE after digestion with XbaI and SpeI indicated that the S. typhi isolates obtained from sporadic cases of infection were much more heterogeneous (at least 13 different REA patterns were detected; Dice coefficient, between 0.73 and 1.0) than those obtained during outbreaks of typhoid fever. The clonal nature and the close genetic identities of isolates from outbreaks in Alor Setar, Penang, Kota Kinabalu, Johor Bahru, and Kota Bahru were suggested by the fact that only a limited number of REA patterns, which mostly differed by only a single band, were detected (one to four patterns; Dice coefficient, between 0.82 and 1.0), although a different pattern was associated with each of these outbreaks. Comparison of REA patterns with ribotyping for 18 S. typhi isolates involved in sporadic cases of infection showed a good correlation, in that 72% of the isolates were in the same group. There was no clear correlation of phage types with a specific REA pattern. We conclude that PFGE of s. typhi chromosomal DNA digested with infrequently cutting restriction endonucleases is a useful method for comparing and differentiating S. typhi isolates for epidemiological purposes.

Composite resin reinforcement of flared canals using light-transmitting plastic posts.

Abstract: Composite resins have been advocated as a reinforcing build-up material for badly damaged endodontically treated teeth with flared canals. However, the control of an autocuring composite resin is difficult because it polymerizes rapidly within the root canal. While the light-curing composite resins are more user friendly, their polymerization can be a problem deep in the root canal. Light-transmitting plastic posts allow the transmission of light into the root canal and enable intraradicular composite resin reconstitution and reinforcement of weakened roots. At the same time, the light-transmitting plastic post forms an optimal post canal in the rehabilitated root and can accurately fit a matching retentive final post. These light-transmitting posts are a useful addition to the dental armamentarium.

Inhibition of tumour promotion by various palm‐oil tocotrienols

Abstract: Inhibition of tumour promotion by various vitamin E compounds (tocopherols and tocotrienols) and some of their dimers was examined by an in vitro assay utilizing the activation of Epstein-Barr virus (EBV) early antigen (EA) expression in EBV-genome-carrying human lymphoblastoid cells. The results reveal that γ- and δ-tocotrienols derived from palm oil exhibit a strong activity against tumour promotion by inhibiting EBV EA expression in Raji cells induced by 12-O-tetradecanoylphorbol-13-acetate (TPA). However, α- and γ-tocopherols and dimers of γ-tocotrienol or γ-tocopherol lack this activity. © 1994 Wiley-Liss, Inc.

Some evidence on the determinants of student performance in the University of Malaya introductory accounting course

Abstract: This study develops model to identify factors to explain student examination performance in the first-level tertiary accounitng course at the University of Malaya. The absence of Published Malaysian research on this area has been the prime motiviation for this study. In addition, the influence of urban-rural residential status of students is studied: this is a unique feature of developing economies, hence neglected in studies of developed countries. Using stepwise multiple regression analysis, three academic factors are found to significantly explain 66% of the variations in performance. Having studied high-school accounting, mathematics and grades in high-school econemics are important predictors of performance. However, the socio-demographic variables of gender and residential status do not contribute signficantly to performance variablilty. The study's model compares favourably with the resluts of other published findings in the USA, Australia and Hong Kong.

Aggregation and predisposition to Ascaris lumbricoides and Trichuris trichiura at the familial level.

Abstract: This study examines the persistence of familial aggregation and familial predisposition to Ascaris lumbricoides and Trichuris trichiura infection over 2 periods of treatment and reinfection, in an urban community in Kuala Lumpur, Malaysia. Both parasite species were shown to be aggregated (assessed by the variance to mean ratio) within families at all 3 interventions, although no consistent trend in aggregation was observed over the period of the study. Associations between mean A. lumbricoides and T. trichiura infection levels of families, at all 3 interventions, were highly significant (P < 0·0001), suggesting persistent predisposition at the family level.

Socio-Economic Factors Associated with Intestinal Parasites Among Children Living in Gombak, Malaysia

Abstract: Fecal specimens collected from 456 school children in Gombak, Malaysia, revealed an overall prevalence rate of 62.9%. The most common parasite found was Trichuris trichiura (47.1%) followed by Giardia intestinalis (14.7%), Entamoeba coli (11.4%), Entamoeba histolytica (9.9%) and Ascaris lumbricoides (7.9%). Infection rates were high among the Indonesian immigrant workers' children (90%) followed by the Orang Asli (79.5%), Malay (59.4%) and Indians (36.4%). Females (66.3%) had a higher prevalence rate than the males (58.5%). The prevalence of infection was found to be associated with the socio-economic status, water supply, sanitary disposal of feces and family size. Albendazole administered as a single dose (400 mg) was found to be effective against Ascaris (100%) and hookworm (92.3%) but was not effective against Trichuris (39.2%).

Zoogeography and biodiversity of the freshwater fishes of Southeast Asia

Abstract: The ichthyofauna of the freshwater system of Southeast Asia is extremely diverse. A recent estimate of about 1000 species is probably an understatement. More than 10 new species are being added to the list annually. The distribution pattern of the Southeast Asian freshwater fishes can be divided into five zoogeographic regions. The first one is the Salween basin in Burma, with fishes mainly of the Indian subcontinent origin such as Amblypharyngodon atkinsoni, Bangana almorae and Brachydanio jayarami. The second zoogeographic area is the Mekong, Chao Phraya and Mae Khlong drainages which harbour fishes typical of the mainland of Southeast Asia such as Acanthorhodeus deignani, Barbichthys nitidus and Cirrhinus siamensis. The Malay Peninsula is the third region whose species composition is heavily influenced by the Siamese (such as Homaloptera smithi, Tuberoschistura baenzigeri and Botia beauforti) and Indonesian (such as Botia hymenophysa, Luciocephalus pulcher and Parosphromenus deissneri) elements. The islands of Sumatra, Borneo and Java are the fourth zoogeographic area of fish distribution. These islands show a high degree of endemism, especially in fishes of the family Belontiidae. Finally, the freshwater system of the Philippines is the last zoogeographic region of Southeast Asia. The area is characterized by the presence of closely related species of the cyprinids especially in Lake Lanao. Currently, high diversity of these freshwater fishes is being threatened by land development, such as deforestation, road construction and land expansion for plantation. Recent studies in the Gombak River basin show the extermination of 41 per cent of native fish species from 1969 to 1990. This is probably due to the construction of highways, logging, as well as land clearing for agriculture.

A kinetic study on isothermal crystallization of palm oil by solid fat content measurements.

Abstract: Isothermal crystallization of plam oil was studied by means of differential scanning calorimetry (DSC) as well as by nuclear magnetic resonance spectrometry to monitor its solid fat content (SFC). The temperature of crystallization (Tc) varied from 0 to 30°C, depending on the method used. The plot of %SFC vs. time at 25°C was sigmoidal in shape. However, at lower temperatures, two consecutive curves were clearly visible. Results from DSC experiments showed the following interesting features. At each Tc, the crystals produced were of different compositions. From 0 to 8°C, the thermogram showed three peaks, with the first two peaks (I and II) sharp, and the third (III) rather broad. At elevated temperatures up to 20°C, peak II disappeared totally while peak III tended to shift toward peak I. Above 20°C, both peaks shifted downward to longer times. Peak I continued to be broadened, and then suddenly disappeared at Tc above 24°C. The melting thermograms of the crystals obtained above and below this cut-off point were distinctly different. Kinetic studies on isothermal crystallization based on the data of SFC measurements showed that the data fit well into the Avrami-Erofeev equation with n=3 over the first 70% of the crystallization.

Vertical stratification of fruit bats (Pteropodidae) in lowland dipterocarp rainforest in Malaysia

Abstract: Mistnets were set at ground level and 11–30 m above ground in lowland rainforest at Kuala Lompat in peninsular Malaysia, and Sepilok in Sabah, to compare the abundance of fruit bats in the subcanopy and at ground level. Capture rates in the subcanopy were up to 100 times greater than at ground level, averaging 3–7 bats per net-night. Species diversity was higher in the subcanopy than forest understorey. Two species that were frequently captured in the subcanopy, Megaerops wetmorei and Dyacopterus spadiceus , were previously thought to be rare. The abundance of Old World fruit bats in the subcanopy indicates that their roles in pollination and seed dispersal of Malaysian forest trees may be greater than previously recognized. Further research on foraging ranges, food selection and roosting habits is required to determine the overall importance of fruit bats in forest regeneration through seed dispersal, and the adequacy of existing reserves for their conservation.

Do fertility intentions predict subsequent behavior? Evidence from Peninsular Malaysia.

Abstract: Data from the 1984 Malaysian Population and Family Survey were matched with birth registration records for 1985-87 to determine the accuracy of statements regarding desired family size that were reported in a household survey in predicting subsequent reproductive behavior. The findings of this study were that stated fertility intention provides fairly accurate forecasts of fertility behavior in the subsequent period. In other words, whether a woman has another child is predicted closely by whether she wanted an additional child. Informational, educational, and motivational activities of family planning programs would, therefore, have greater success in reducing family size if fertility intentions were taken into account.

Periodontal status of teeth in contact with denture in removable partial denture wearers

Abstract: The aims of the study were to determine the periodontal status of the teeth in contact with removable partial dentures (RPDs) and to compare them with other teeth in the opposing arch not related to any prosthesis. The periodontal status was also assessed in relation to the age of the dentures. Four hundred and twenty-seven patients treated with RPDs from 1981 to 1986 were recalled for examination. Prior to prosthetic treatment they were given periodontal treatment and fillings when required. Initially all were given oral hygiene instructions and motivation. They were reviewed regularly only on a short-term basis. Eighteen patients were suitable for the present study comprising of eight males and 10 females whose mean age was 41 years. The RPDs were in use from 1.5 to 8 years (mean 4.6 years). The following parameters were assessed: Plaque index (P1I), Gingival index (GI), loss of attachment (LA) and tooth mobility. The wearing of RPDs resulted in higher P1I, GI and LA compared to the controls and these differences were statistically significant. There was an increased frequency of higher P1I, GI and LA with the increase in denture age. Minor changes in tooth mobility were observed. It was concluded that the wearing of RPDs was detrimental to periodontal health in patients whose oral hygiene was less than adequate.

CD4+ T-Lymphocyte Measures in the Treatment of Individuals Infected With Human Immunodeficiency Virus Type 1: A Review for Clinical Practitioners

Abstract: The CD4+ lymphocyte is a major target of the human immunodeficiency virus type 1 (HIV-1). CD4+ T-lymphocyte measures have been used to predict the risk of HIV-1-related complications in diverse populations, to guide management decisions, and to define cases of the acquired immunodeficiency syndrome (AIDS). To examine the role of CD4+ measures in the management and epidemiologic monitoring of HIV-1 infection, we evaluated current literature regarding the accuracy and precision of CD4+ measures and the use of these and other prognostic measures in the care of HIV-1-infected persons. Several studies have reported wide intraindividual and interindividual variability in the absolute CD4+ count, which can detract from its clinical usefulness. Approaches to address this variability include the following: drawing specimens at a similar time of the day; monitoring CD4+ percent that has less variability; following a meticulous laboratory technique; using serial tests to guide management decisions; and retesting after efforts to eliminate transient treatment and clinical factors that can affect the CD4+ count. The expense and limited availability of CD4+ measures also present barriers to widespread use. Other laboratory and clinical factors offer additional prognostic information and have an evolving role in management decisions. CD4+ measures have an important role in HIV-1 clinical care, research, and disease surveillance, but strategies are required to address problems with variability, expense, and availability.

Endometriosis and infertility: raised iron concentration in the peritoneal fluid and its effect on the acrosome reaction.

Abstract: Endometriosis and infertility are commonly associated. This study investigated the role of accelerated lipid peroxidation of spermatozoa by the peritoneal fluid of patients with endometriosis as a cause for this association. It proposes that the increased iron concentration present in the fluid of these patients acts as a catalyst for the process. Peritoneal fluid from 25 patients with endometriosis and 25 matched controls was obtained at laparoscopy. Spermatozoa were incubated in the fluid from both groups and the subsequent acrosome reaction rates analysed. The relationship between these results and iron concentration in the fluid was examined. A significant decrease in the acrosome reaction rate was seen in the endometriotic group (P = 0.034). Overall, a decrease in the acrosome reaction rate was associated with an increased iron concentration in the fluid (18 of the 25 pairs). In mild disease, (six of 11 pairs), the relationship was not as marked as that in severe disease (12 of 14 pairs). These results suggest that the peritoneal fluid in patients with endometriosis has a detrimental action on the acrosome reaction of spermatozoa in vitro.

Depth of composite polymerization within simulated root canals using light-transmitting posts.

Abstract: In this study, the depth of cure of composite resins cured within simulated root canals by means of light-transmitting plastic posts was compared to that achieved by the conventional light-curing method. Six sizes of posts with diameters of 1.05 mm, 1.20 mm, 1.35 mm, 1.50 mm, 1.65 mm, and 1.80 mm were investigated. In general, the larger the post diameter, the greater was the depth of cure. There were significant differences in the depth of cure between the control and all sizes of posts investigated. There were also significant differences between the various post diameters except for the 1.35 mm and 1.50 mm diameter posts. It was possible to achieve a depth of cure exceeding 11 mm using these light-transmitting posts.

Inhibition of acetylcholinesterase in the australian freshwater shrimp (Paratya australiensis) by profenofos

Abstract: Profenofos induced significant inhibitory effects on the AChE activity of Paratya australiensis ranging from >40% inhibition at sublethal concentrations of 0.1 to 1.0 μg/L to >80% inhibition at lethal concentrations of ≥10 μg/L. Sublethal chronic exposure (21 d) at a concentration of 0.15 μg/L caused persistent reduction in AChE activity of up to 60%, whereas recovery of AChE activity to normal levels from a 24-h exposure to 0.1 μg/L profenofos required less than 9 d. Shrimp were exposed to 0.1 μg/L profenofos for 24 h and then allowed a period of recovery in pesticide-free water; at the end of this treatment the AChE activity of affected shrimp approached control level. Subsequent 24-h exposures with intermittent stay in pesticide-free water for the same duration as the initial recovery phase resulted in greater inhibition in AChE activity as compared to the initial 24-h exposure. Furthermore, the AChE activity of shrimp at the end of the recovery phases remained significantly depressed.

Possible microbial utilization of sago processing wastes

Abstract: The nutrient content of sago pith and subsequently sago hampas is very low, the bulk being crude fibres and some starch attached to the hampas. The protein content is about 0.6–0.7%, which is unfavourable for most animals. The fibre content of sago hampas is about 12%. Fungal treatment of sago hampas seems possible. Fungi can grow rapidly and are able to utilise complex carbohydrates such as starch and lignocellulose. An important area of research into the utilization of sago hampas would be to find suitable, palatable, non-toxic, high protein-containing and rapidly-growing fungi to grow on and utilize the sago hampas. The hampas could be supplemented prior to inoculation with different and economically viable sources of nitrogen available around the factory area. Microbial utilization could result in the production of biomass as quality animal feed supplements.

Genetic relatedness as a determinant of predisposition to Ascaris lumbricoides and Trichuris trichiura infection

Abstract: The present study examines the role of host genetics in predisposition to Ascaris lumbricoides and Trichuris trichiura infection, by comparing the associations between age-standardized infection intensities of parents and their children (genetically related), with age-standardized infection intensities of parents alone (not related), within families previously demonstrated to exhibit familial predisposition. The lack of a consistent trend in infection intensity associations within families, in particular the lack of a stronger association between parents and their children than between unrelated parents, suggests that host genetic factors are not a major determinant of infection status. If there is a genetic basis for predisposition, then the data suggest that the effects of this genetic basis are overwhelmed by other, environmental or behavioural features of the family household.

A perspective of material management practices in a fast developing economy: the case of Malaysia

Abstract: Many management-related problems exist amongst local contractors in developing countries. Problems vary in nature and intensity but are usually associated with inefficient management of construction resources including materials, labour, plant and subcontractors. This paper deals with material management practices in the construction industry in Malaysia. A questionnaire survey and interviews were conducted with local practising public works contractors to examine the management of materials and to identify the nature of problems associated with material management. Problems identified included delay in the delivery of materials, the lack of use of advanced planning techniques, material variances and computers. There is a need for an improved material management approach by contractors in a developing country.

Molecular epidemiologic analysis of Vibrio cholerae O1 isolates by pulsed-field gel electrophoresis.

Abstract: 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.

Tarantism, dancing mania and demonopathy : the anthro-political aspects of mass psychogenic illness

Abstract: This study questions the widely held assumption that the phenomenon known as mass psychogenic illness (MPI) exists per se in nature as a psychiatric disorder. Most MPI studies are problematical, being descriptive, retrospective investigations of specific incidents which conform to a set of pre-existing symptom criteria that are used to determine the presence of collective psychosomatic illness. Diagnoses are based upon subjective, ambiguous categories that reflect stereotypes of female normality which assume the presence of a transcultural disease or disorder entity, underemphasizing or ignoring the significance of episodes as culturally conditioned roles of social action. Examples of this bias include the mislabelling of dancing manias, tarantism and demonopathy in Europe since the Middle Ages as culture-specific variants of MPI. While 'victims' are typified as mentally disturbed females possessing abnormal personality characteristics who are exhibiting cathartic reactions to stress, it is argued that episodes may involve normal, rational people who possess unfamiliar conduct codes, world-views and political agendas that differ significantly from those of Western-trained investigators who often judge these illness behaviours independent of their local context and meanings.

Some Epidemiological Aspects and Economic Costs of Injuries in Malaysia

Abstract: Injuries are one of the leading causes of death in the world. In Malaysia, injuries form one of the three main causes of mortality. They are also an important cause of permanent and temporary disab...

A high incidence of serum IgG antibodies to the Epstein-Barr virus replication activator protein in nasopharyngeal carcinoma.

Abstract: TheBamHI Z EBV replication activator (ZEBRA) protein is involved in the switch from latency to productive cycle of Epstein-Barr virus. A recombinant ZEBRA protein was synthesized and assessed in enzymelinked immunosorbent assay (ELISA) for serum IgG response in nasopharyngeal carcinoma (NPC) patients. In 100 NPC serum samples that were positive for IgA to the EBV viral capsid antigen (VCA), 75% had IgG anti-ZEBRA antibodies. In contrast, only 3/83 (3.6%) serum samples from healthy donors and 2/50 (4%) from other cancers were positive for IgG to ZEBRA. Interestingly, in a selected group of 100 NPC sera negative for IgA to VCA, 25% contained IgG anti-ZEBRA antibodies. This suggests that the ELISA for IgG anti-ZEBRA may also identify earlier cases of NPC not detected by the conventional immunofluorescence test for IgA to VCA.