Showing papers by "University of Malaya published in 1993"

Fulminant hepatitis in dengue infection.

Abstract: Eight cases of liver failure and encephalopathy were observed among twenty cases of grade 3 and grade 4 dengue hemorrhagic fever/dengue shock syndrome admitted to the Department of Pediatrics, University Hospital, Kuala Lumpur from January 1990 to December 1991. All patients with deterioriation in mental status showed a marked increase in liver enzymes (aspartate and alanine aminotransaminases) and severe coagulopathy. Six patients needed cerebral protection, including ventilation, intravenous sedation and muscle relaxants. There was one death during the period of study and one case of residual hemiparesis in a boy who had, in addition, intracerebral hemorrhage. All other survivors had complete recovery of liver and neurological function.

Epidural tramadol for postoperative pain relief

Abstract: The efficacy of epidurally administered tramadol hydrochloride, a weak centrally acting analgesic, was studied for the relief of postoperative pain. Sixty patients undergoing abdominal surgery were randomly allocated to three treatment groups to be given the following agents by the epidural route: group 1 tramadol 50 mg; group 2 tramadol 100 mg; group 3 10 ml of bupivacaine 0.25%. The drugs were administered at the patients' request with each patient being allowed four doses in the first 24 h following surgery. Blood pressure, pulse rate, respiratory rate, arterial blood gas analyses, pain scores, the interval between doses and the occurrence of any side effects were recorded. Pain scores (assessed using a visual analogue scale) were significantly less (p < 0.05) at 3, 12, and 24 h in patients receiving tramadol 100 mg than in those receiving tramadol 50 mg or bupivacaine. The mean interval between doses for groups 1, 2 and 3 was 7.40 h, 9.36 h and 5.98 h respectively. The mean interval in group 2 was significantly longer than in group 3 (p < 0.05). The incidence of nausea and vomiting in group 2 was significantly higher than in group 3 (p < 0.05).

Gravitational Experiments in the Laboratory

Abstract: This book provides an up-to-date account of the precise experiments used to explore the nature of universal gravitation that can be performed in a terrestrial laboratory. The experiments required are at the limits of sensitivity of mechanical measurements. The problems of experiment design are discussed, and critical accounts given of the principal experiments testing the inverse square law and the principle of equivalence, and measuring the constant of gravitation. An analysis of the effects of noise and other disturbances is also provided, further highlighting the care that is needed in experimental design and performance. The motivation for undertaking such experiments is also discussed. The book will be of value to graduate students, researchers and teachers who are engaged in either theoretical or experimental studies of gravitation, and who wish to understand the nature and problems of laboratory experiments in this field.

Transesterification of cocoa butter by fungal lipases : effect of solvent on 1,3-specificity

Abstract: Transesterification and alcoholysis reactions catalyzed by immobilized lipases fromMucor miehei andHumicola lanuginosa in hexane gave fatty acid esters that did not reflect the expected 1,3-specificity of the enzymes, due to competing acyl migrations in the partial glyceride products. However, both lipases were 1,3-specific in reactions when diethyl ether was used as a solvent, and this provided a convenient analytical methodology in combination with gas chromatography and nuclear magnetic resonance spectroscopy for the determination of fatty acid distribution within triglycerides.

Optical Properties of Annealed Tin(II) Oxide in Different Ambients

Abstract: Tin (II) oxide powder is coated at room temperature onto transparent glass substrates by direct thermal evaporation. The films have high transparency (more than 80%) in the visible and near-infrared regions of the electromagnetic spectrum. In the region between 300 and 1300 nm interference fringes are sharp and well defined. The interference fringes are used to calculate the thickness of the amorphous as-prepared film (≈ 722 nm) and the refractive index is found to be 1.84 at 700 nm. The absorption coefficient of this film ≈ 6 × 10−3 cm−1 at 355 nm. The thickness of the film thus measured was compared with results obtained from the Tolansky method. The optical band gap calculated from the simple power law was found to be 3.3 eV. The films are annealed in either O2 or N2 atmosphere for 1 h at various temperatures between 250 and 400 °C. It is found that the film is quite stable until about 400 °C, beyond which the optical band gap reduces to 2.7 eV (in N2 atmosphere) and increases to 3.4 eV (in O2 atmosphere). At higher temperature the films annealed in nitrogen ambient do not show the interference fringes, whereas in the oxygen atmosphere the interference fringes are still observed.

A rapid test to measure performance, emission and wear of a diesel engine fueled with palm oil diesel

Abstract: Results of performance, emission and tribological evaluations of palm oil methyl ester and its blends with conventional diesel in an automobile diesel engine test bed are presented Polymerization and carbon deposits on the fuel injector were monitored CO, CO2, O2, combustion efficiency and temperature of exhaust gases were also measured Palm oil methyl ester and its blends have great potential as alternative diesel fuel Performance and exhaust gas emission for palm oil methyl ester and its blends with conventional diesel are comparable with those of conventional diesel fuel Palm oil methyl ester does not pose a severe environmental problem and will not deteriorate engine and bearing components

Desmoplastic variant of ameloblastoma in Malaysians

Abstract: Seventeen cases are reported of desmoplastic variant of ameloblastoma of the jaws observed during the years 1967–1991. There were 12 females and 5 males, and these consisted of 7 Chinese, 6 Malays, 2 Indians, 1 Sikh and 1 Kadazan. Their ages at diagnosis ranged from 21–60 years with a mean of 36.6 years. There were 10 mandibular and 7 maxillary tumours. Of these, 14 cases involved the anterior segment with extension to the premolar region in 5 cases. 60% of cases were radiologically suggestive of fibro-osseous lesions. The main mode of treatment was resection and 1 case presented with recurrence. The findings of this study were compared with those of previous reports.

Mycorrhizal status of epiphytes in Malaysian oil palm plantations

Abstract: Epiphytic plants were collected from four oil palm plantations in Peninsular Malaysia and their mycorrhizal status determined. Conspecific plants with a terrestrial habit (16 species) and rhizosphere soils were also examined for mycorrhizal colonization and glomalean fungi, respectively. Twelve species of glomalean fungi were recovered from the four oil palm plantation soils. Of the 29 epiphytic species in 16 families belonging to the bryophytes, pteridophytes and angiosperms, only four species of angiosperms that were facultative epiphytes and a hemiepiphyte growing within 0.4 m of ground level had vesicular-arbuscular mycorrhizal (VAM) fungi. Bioassays of organic debris from oil palm trunks did not produce vesicular-arbuscular mycorrhizas on maize. Six epiphytic species grown in the greenhouse in pots containing oil palm rhizosphere soils rooted and had VAM fungi and thus may be facultative epiphytes. Five other epiphyte species failed to grow in pots and are probably obligate epiphytes. Seven epiphyte species that established themselves in pots failed to form vesicular-arbuscular mycorrhizas.

‘Combined ameloblastoma and odontogenic keratocyst’ or ‘keratinising ameloblastoma’

Abstract: Four cases of either combined occurrence of ameloblastoma and odontogenic keratocyst or a rare keratinising variant of ameloblastoma are presented. The cardinal histomorphologic characteristics are simultaneous occurrence of ameloblastomatous epithelial islands with central keratinisation and multiple keratinising cysts. Immunohistochemically the tumour elements were keratin positive and occasionally S-100 protein and desmin positive. Major differential diagnosis of these neoplasms are discussed.

The vibratory pattern of ultrasonic files driven piezoelectrically.

Abstract: Summary The pattern of oscillation of a Piezon-Master 400 ultrasonic file driven by a piezoelectric transducer was studied in air and on water. In addition, the displacement amplitudes of the files were measured. The findings were compared with those observed with the Cavi-Endo unit reported in another study (Ahmad 1969). It was observed that the file vibrated such that a standing wave was formed on the file and it exhibited points of maximum deflection (antinode) and points of minimum deflection (node) with the largest deflection occurring at the apical end. This pattern of oscillation was similar to that exhibited by the Cavi-Endo file which employed a magnetostrictive transducer. However, the displacement amplitudes were very much higher than those exhibited by the Cavi-Endo. It is considered that the 120° angle of the file holder inherent in the Piezon- Master 400 unit and the more effective power transmission with the piezoelectric transducer may have contributed to the large amplitudes.

The effect of systemic ibuprofen on gingival inflammation in humans

Abstract: This clinical trial investigated the influence of short-term ibuprofen therapy on the early phase of the treatment of adult chronic periodontitis. The subjects were 17 patients in good general health referred for specialist periodontal treatment, having moderate chronic adult periodontitis. A series of assessments were made every 2 weeks over an 8-week period, including evaluations of oral hygiene, gingival inflammation and probing pocket depths. All participants received oral hygiene instruction, and following baseline examinations, had half the dentition, chosen at random, treated by scaling and root planing. The patients were randomly distributed into 2 groups, a test group receiving a 14-day course of 800 mg ibuprofen daily, in 4 divided doses, and a control group who did not receive any drug regime. At the 2-week assessment following the drug regime, significantly greater reduction in gingival bleeding, colour and pocketing was detected in the test compared with the control group. The beneficial effects were less evident thereafter. Although clinical application of the regime used in this study would not be justified by these results, further research into anti-inflammatory agents as an adjunct in the treatment of periodontal diseases could be considered, in the light of the beneficial effect on gingivitis in the early phase of periodontal treatment reported.

Severe Progressive Periodontal Destruction Due to Radiation Tissue Injury

Abstract: Cancer radiotherapy to the head and neck region results in short- and long-term radiation tissue injuries. Radiation bone injury is a long-term manifestation which could progress to osteoradionecrosis. A case of radiation tissue injury to the periodontium is presented. The possible pathogenesis of these events is described as they relate to the sequential radiographic changes observed over a period of 6 years until the involved teeth were exfoliated. The post-irradiation management of the teeth with advancing periodontal disease in the path of irradiation was by conservative means, including good personal oral hygiene care, scaling and root planing, periodic chlorhexidine irrigation, and topical fluoride application.

Vocalizations in response to predators in three species of Malaysian Callosciurus (Sciuridae)

Abstract: Anti-predator vocalizations were studied in three species of tree squirrel, Callosciurus , in Ulu Gombak, Selangor Darul Ehsan, Malaysia. In the study area (ca. 10 ha), C. notatus was dominant in areas of low tree density, C. nigrovittatus in dense forests with tall trees, and C. caniceps in shrubs. All three species produced different calls to different predators; terrestrial carnivores, raptors, and snakes. Each signal caused conspecific individuals to adopt a different escape strategy. On hearing the repetitious, staccato barks toward carnivores, neighboring individuals ran up trees. A single bark was produced when raptors flew in the distance, which made conspecifics freeze. However, squirrels produced a rattle sound toward raptors in cases of close encounter. Squirrels moved toward the sound source of squeaks to snakes, and mobbed in a group. Calling frequency, intensity, duration, and sound structure of each call were compared among three species, and related to habitat selection.

Rapid dengue diagnosis and interpretation.

Abstract: Outbreaks of dengue fever (DF) and dengue haemorrhagic fever (DHF) pose a serious threat to more than 85 tropical and sub-tropical countries throughout the world. The World Health Organization has identified dengue to be one of the most under-reported diseases, with actual cases in the millions. It is also recognised as one of the most important and rapidly rising mosquito-transmitted infections in the world. The alar-ming increase in cases may be due to many factors, including rapid population growth, expanding urbanization, rising economies, inadequate municipal water supplies, and difficulties in handling refuse disposal. These lead to an abundance of new breeding sites for the mosquito vectors of the disease, while human migration patterns disperse vectors and viruses into new areas. National public health authorities are often unable to deal successfully with dengue outbreaks and epidemics. Although a vaccine developed in Thailand against dengue viruses is on the horizon, it will take a few years before i t becomes available.

Generation of poisson and gamma random vectors with given marginals and covariance matrix

Abstract: In simulation studies we usually require the use sampling techniques involving the generation of random vectors from a multivariate population with given marginal distributions and specified correlation structure.This paper proposes two procedures for generating multivariate Poisson and Gamma random vectors having given non—identical marginal distrbutions and fixed covariance matrix with general positive entires.The generating procedures are based on a multivariate transformation method analogous to that used in the simulation of normal random vector.Properties and generating algorithms of the proposed procedures are given..

Nasal septal abscess--retrospective analysis of 14 cases from University Hospital, Kuala Lumpur.

Abstract: Fourteen patients who presented to the University Hospital of Kuala Lumpur between June 1981 and June 1991 were reviewed retrospectively. Nasal septal abscesses are uncommon and therefore there are limited reports in the medical literature. Early diagnosis and immediate therapy is mandatory to avoid cosmetic nasal deformity or intracranial infection. Two out of the fourteen patients developed saddle nose deformity and septal perforation because of delay in treatment, the cases were misdiagnosed by non-otolaryngologist as turbinates swelling. The leading cause of nasal septal abscess was non-surgical trauma which accounted for about 85.7%. The commonest pathogenic organism isolated from the pus of nasal septal abscess was Staphylococcus aureus.

Nitrogen concentrations in a mangrove creek with a large tidal range, Peninsular Malaysia

Abstract: We report on various species of nitrogen in subsurface water samples taken at the mouth of Sungai Sementa Besar, a creek about 4.5 km long off the Straits of Malacca and draining a mangrove forest on the west coast of Peninsular Malaysia. This tide-dominated watercourse shows a range greater than 4.5 metres from low to high water during springs, only 1.0 m during neaps, and salinities at the mouth of 30‰ or greater. After heavy rains or when the tides inundate the forest floor, inorganic nitrogen values increase as much as tenfold at the mouth. Particulate and total organic nitrogen also increase at the mouth under these conditions. There were also comparative highs of organic inputs at other times.