Showing papers by "University of Malaya published in 1991"
TL;DR: A unique association of EBV with undifferentiated NPC is suggested and concepts assigning different biological properties to undifferentiate NPC as compared with squamous cell NPC are supported.
Abstract: The Epstein-Barr virus (EBV) is consistently associated with undifferentiated nasopharyngeal carcinoma (NPC). There is, however, conflicting evidence as to whether squamous cell NPCs are also EBV-associated. Moreover, it has been proposed that other epithelial tumours, particularly thymomas and thymic carcinomas, should be included in the group of EBV-associated neoplasias. However, since the viral DNA in these studies was demonstrated only in extracted DNA, the cellular origin of the viral DNA is uncertain. We have therefore investigated 152 epithelial tumours from various sites for the presence of EBV-DNA by in situ hybridization with 35S-labelled probes. Sixty-eight of 77 undifferentiated NPCs showed an EBV-specific autoradiographic signal, thus confirming the strong association of this tumour type with EBV even in geographical areas where undifferentiated NPC is not endemic. None of eight squamous cell NPCs showed an EBV-specific signal. All of 15 carcinomas with a similar morphology to undifferentiated NPC but from different anatomic sites (thymus, tonsil, breast) were EBV-negative as were 9 thymomas, 26 squamous cell carcinomas of the palatine tonsil, and 14 cervical carcinomas. Our results therefore suggest a unique association of EBV with undifferentiated NPC and support concepts assigning different biological properties to undifferentiated NPC as compared with squamous cell NPC.
175 citations
TL;DR: In this article, a method for reducing a radial network into a single line equivalent has been developed which simplifies lengthy calculations of an unreduced network and enables the fast computation of loadflow solutions of distribution networks.
157 citations
01 Jan 1991
TL;DR: In this paper, the current trend in the choice of mateials is discussed and the current guidelines for the preparation of batteries are provided, as well as a review of the current state of the art.
Abstract: Solid State batteries have been prepared from a wide range of electrolyte materials. Lithium, Silver and copper electrolytes are used in the preparation of microbatteries. This article is intended to provide guidelines for the choice of material in the preparation of batteries. The current trend in the choice of mateials is discussed.
111 citations
TL;DR: The results show that the palmvitee has a hypocholesterolemic effect and lowered both serum total cholesterol (TC) and low-density-lipoprotein cholesterol (LDL-C) concentrations in all the volunteers.
107 citations
Journal Article•
[...]
TL;DR: It is apparent and undeniable that the New Englishes are well past the evolution stage - although it is also undeniable that language is always never in a 'freeze frame' so to speak as discussed by the authors.
Abstract: It is apparent and undeniable, therefore, that the New Englishes are well past the evolution stage - although it is also undeniable that language is always never in a 'freeze frame' so to speak The New Englishes, however, have passed their formative years, and coupled with the fact that they are wholesomely accepted by their speakers - the need for complete recognition is past denying here, and as the saying goes, "The best may be the enemy of the good" let not standard British English put off any of these New Englishes, all that is asked for is tolerance towards them as Charles Taylor (1984) says, "While with languages in general, we should teach the language, and not about the language: with varieties, the reverse is true: teach about varieties - but never attempt to teach them"
90 citations
TL;DR: It is concluded that pericardiectomy has a definite place in the management of purulent pericarditis and the importance of early diagnosis before a significant degree of cardiac tamponade occurs.
79 citations
TL;DR: A study to determine the role of Helicobacter pylori in non-ulcer dyspepsia (NUD) and the efficacy of colloidal bismuth subcitrate (CBS) in the treatment of NUD found the H.pylori-positive, CBS-treated group recorded a significantly higher improvement than the other groups (p less than 0.001).
Abstract: A study was undertaken to determine the role of Helicobacter pylori in non-ulcer dyspepsia (NUD) and to determine the efficacy of colloidal bismuth subcitrate (CBS) in the treatment of NUD. Seventy-one patients were randomly allocated (double blind) to CBS or placebo, two tablets twice daily for 4 weeks. The severity of dyspepsia was scored and endoscopies performed before and after treatment, and antral biopsy specimens were taken for bacteriologic and histologic examination. Forty patients had H. pylori infection, and all had changes of chronic active gastritis. H. pylori was cleared from 17 to 21 patients (81%) treated with CBS, whereas none of the 19 patients treated with placebo cleared the bacteria. Improvement in histology was noted in 15 of 21 patients (71.4%) treated with CBS, whereas no improvement was noted in any of the placebo controls. Thirty-one patients were negative for H. pylori. All had either normal gastric histology or minor degrees of inflammation. Seventeen of these patients received CBS, and 14 received placebo. All groups reported improvement in the symptom score; however, the H. pylori-positive, CBS-treated group recorded a significantly higher improvement than the other groups (p less than 0.001). Relapse of H. pylori infection after initial clearance of the bacteria was high. Twelve of 16 patients evaluated relapsed 1 month after withdrawal of CBS.
76 citations
TL;DR: Examination of the effect of a number of drugs which themselves undergo glucuronidation on AZT conjugation by human liver microsomes in vitro enables a screen of potentially important drug interactions to be carried out.
Abstract: 1. Zidovudine (3'-azido-3'-deoxythymidine; AZT) is the drug of proven efficacy available for the treatment of patients with AIDS or ARC. It is eliminated mainly by hepatic glucuronidation. Therefore, interference with this metabolic pathway may lead to enhancement of AZT effect or to increased toxicity of the drug. We have examined the effect of a number of drugs which themselves undergo glucuronidation on AZT conjugation by human liver microsomes in vitro. 2. AZT glucuronidation followed Michaelis-Menten kinetics. The apparent Km and Vmax values (mean +/- s.d., n = 5), were 2.60 +/- 0.52 mM and 68.0 +/- 23.4 nmol h-1 mg-1, respectively, as determined from Eadie-Hofstee plots. 3. Dideoxyinosine, sulphanilamide and paracetamol were essentially non-inhibitory at concentrations up to 10 mM (4 times the concentration of AZT in the incubation). The most marked inhibitory effects were seen with indomethacin, naproxen, chloramphenicol, probenecid and ethinyloestradiol, with enzyme activity decreased by 97.7, 94.9, 88.7, 83.4% and 79.0%, respectively, at a concentration of 10 mM. Other compounds producing some inhibition of AZT conjugation were oxazepam, salicylic acid and acetylsalicylic acid. 4. Further studies are necessary to characterise the inhibition observed but the method described enables a screen of potentially important drug interactions to be carried out.
60 citations
TL;DR: This is the largest recorded histopathological study of enterobiasis in man and suggests that the worm, carried to the lung as an embolus, impacted in a pulmonary arteriole.
Abstract: Enterobius worms or their eggs, or both, are present in preserved tissue sections or tissue specimens of 259 patients whose medical records are on file at the Armed Forces Institute of Pathology, Washington D.C., U.S.A. The most common site of infection (86.5%) was found to be the lumen of the appendix, where the worms provoke no reaction. Of the 259 patients 11 (4.2%) had worms and/or eggs in granulomas of the abdominal and pelvic peritoneum, and an equal number had granulomas on the peritoneum of the salphinx or on the surface of the ovary. There were also ectopic worms and/or eggs in granulomas on the peritoneum of the small and large intestines (2.7%). These Enterobius granulomas form around degenerating adult worms, around discrete eggs, around clusters of eggs, and, we believe, also around the tracks of migrating worms. Three patients (1.2%) had worms in perianal abscesses. A necrotic granuloma, removed from the lung of one patient, surrounded a degenerating adult worm. This suggests that the worm, carried to the lung as an embolus, impacted in a pulmonary arteriole. A stool specimen of one patient contains eggs of Enterobius, and that of another patient contains an adult Enterobius. This is the largest recorded histopathological study of enterobiasis in man.
55 citations
TL;DR: Many of the affected teeth presented with deep developmental grooves some of which were carious and/or occlusal interference leading to malocclusion, with the maxillary lateral incisors being the most commonly affected.
Abstract: Five hundred and thirty-six patients were examined for the presence of talon cusps. The anomaly was observed in 28 patients (5.2 per cent). There was no sex predilection in the occurrence. Only two patients had a bilateral occurrence, with the maxillary lateral incisors being the most commonly affected. Radiographic evidence of pulpal extension into the cusp was observed in five patients. Many of the affected teeth presented with deep developmental grooves some of which were carious and/or occlusal interference leading to malocclusion.
55 citations
TL;DR: Praziquantel is currently the drug of choice for the treatment of any kind of schistosomiasis, with few side effects, and the only limitation is the cost which restricts its use in many developing countries.
Abstract: Schistosomiasis, a grave and debilitating disease of socioeconomic importance, is increasing in incidence despite concerted efforts to control and contain the disease in all the endemic areas. While a multipronged method of control using health education, sanitation and snail control has been used, chemotherapy and chemoprophylaxis play the most important and crucial role in containing/preventing the transmission of the disease. Schistosomicides such as antimonials were introduced, as early as the 1990s as the drugs of choice and continued to be used until the early 1960s. The antimonials were administered intravenously, and produced severe side effects; the various variables that determined their effects at the site of action made their application difficult and adversely affected their use in large scale chemotherapy. The antimonials were then replaced by hycanthone and lucanthone which were administered intramuscularly. These drugs produced immediate side effects such as hepatotoxicity and gastrointestinal disturbances, and were consequently withdrawn. It was then decided that the alternative was to produce synthetic drugs that could be administered orally. Niridazole, oxamniquine, and metrifonate were introduced as schistosomicidal agents, with drugs like oltipraz and amoscanate still at clinical trial phase. Therapeutic doses of drugs like hycanthone, niridazole and amoscanate have been found to cause many major side effects. A significant advance in the control of schistosomiasis chemotherapy is the introduction of a relatively safe, effective, broad spectrum oral helminthic agent, praziquantel. Studies have also shown that oxamniquine is as effective as praziquantel in eliminating intestinal S. mansoni infection, and metrifonate is as effective as praziquantel in eliminating urinary S. haematobium and S. mansoni infections. Praziquantel has been found to be effective in treating S. haematobium infections compared with metrifonate and more effective in treating S. mansoni infection when compared with oxamniquine. Because the drug is effective even when treating advanced hepatosplenic schistosomiasis, with few side effects, praziquantel is currently the drug of choice for the treatment of any kind of schistosomiasis. The only limitation is the cost which restricts its use in many developing countries. While effective, safe drugs for mass chemotherapy are being developed, the problem of therapeutic failure and drug resistance is being reported from certain developing countries. Under these circumstances, alternative drugs must be resorted to. Mass treatment, a crucial goal in the eventual control of schistosomiasis, awaits a well-tolerated and nontoxic drug that will ultimately prove to be effective where cure is definite. Until such a time, while eradication of the disease is a near impossibility, reducing the intensity of infection can ultimately reduce morbidity and even mortality.(ABSTRACT TRUNCATED AT 400 WORDS)
TL;DR: A case is made for augmented TNF production having a role for the pathophysiological changes observed in DHF/DSS and mediator modulation as a possible therapeutic approach to treatment.
Abstract: A consecutive series of 24 patients with clinical features of primary dengue infection and 22 controls (14 patients with viral fever of unknown origin and 8 healthy subjects) were assayed for serum levels of tumour necrosis factor (TNF). The acute sera of the 24 patients with clinical dengue infection were positive for dengue virus-specific IgM antibody. Clinically, 8 had dengue fever (DF), 14 dengue haemorrhagic fever (DHF) and 2 dengue shock syndrome (DSS). All 16 patients with DHF/DSS had significantly elevated serum TNF levels but the 8 DF patients had TNF levels equivalent to that in the 22 controls. A case is made for augmented TNF production having a role for the pathophysiological changes observed in DHF/DSS and mediator modulation as a possible therapeutic approach to treatment.
01 Nov 1991
TL;DR: In this paper, the performance of three loadflow techniques is investigated in their ability to analyse distribution network loadflows and the criterion for voltage instability is presented and the ability of the three load flow techniques to predict it is discussed.
Abstract: Loadflow techniques are widely used in the planning and daily operation of power systems including that of the on-line monitoring of distribution system operation. The performance of three loadflow techniques is investigated in their ability to analyse distribution network loadflows. The criterion for voltage instability is presented and the ability of the three loadflow techniques to predict it is discussed.
TL;DR: The data suggest the presence of a side chain binding site in the enzyme, and that the binding site comprises at least five 'subsites': the hydrophobic subsites a, b and c; and the two 'amino' binding subsites d and e.
TL;DR: In this paper, the authors analysed monthly species diversity and other components of diversity of diatom samples collected over a period of one year at eight stations in the Linggi River Basin, Malaysia.
Abstract: Monthly species diversity and other components of diversity of diatom samples collected over a period of one year at eight stations in the Linggi River Basin, Malaysia were analysed. Species diversity ranged between 0.52–3.62 bits individua−1. Among the four stations located in the Linggi River (sensu stricto), highest diversity values were recorded at a station polluted by rubber effluent, followed by the stations unpolluted from point sources. Lowest diversity was recorded at a station polluted with urban sewage. At Kundor River, highest diversity was recorded at stations located downstream of rubber and palm oil waste discharges. On the whole, diversity values at unpolluted stations were always lower than at mildly polluted stations. Severe organic loadings caused low diversity by reducing the number of species (species richness) but did not increase the evenness (equitability) as expected when compared with unpolluted or mildly polluted stations. The changes in species diversity can be related to changes in diatom community structure and thereby changes in water quality, but cannot be used as an index of water quality.
TL;DR: Meticulous screening of patients together with optimal antenatal and intrapartum care will markedly reduce the incidence of uterine rupture and help reduce morbidity and mortality to both mother and fetus.
Abstract: A review of 34 cases of rupture of the pregnancy uterus experienced at University Hospital Kuala Lumpur Malaysia from August 1968-December 1989 is presented. This series represents primarily urban residents with quick access to the service compared to the previous case series of mainly referred cases The incidence was 1 in 2966 deliveries down from 1 in 1584. There was 1 primigravida and 38.2% para 4 and above. There was 18 (53%) scar ruptures 13 (38.2%) spontaneous ruptures and 3 (8.8%) traumatic ruptures. 13 of the 14 with ruptured lower uterine scars occurred in labor and 1 occurred during attempted external version by a TBA. In 7 of 14 an oxytocic was given inadvertently. One woman had received sulprostone at 32 weeks for intrauterine death. Women with spontaneous rupture included 9 grand multiparas 6 of whom received oxytocin and 1 presented in obstructed labor. The traumatic ruptures were related to instrumental delivery with an unengaged head a shoulder dystocia and an anencephaly. The most common clinical sign was tachycardia (65/7%); others were loss of fetal heart sounds (41.2%) and uterine tenderness (35.3%). Other signs were vaginal bleeding hypotension bloodstained liquor regression of fetal parts hematuria. 2 patients had no signs. 44.1% had hysterectomy and the rest were managed conservatively. There was no maternal death. The fetal loss rate was none with scar rupture but 69.2% with spontaneous and 66.75 with traumatic rupture of the uterus.
Journal Article•
TL;DR: Nine thousand and six hundred infants delivered in a maternity hospital were examined for the prevalence of natal and neonatal teeth; the prevalence among this group was noted.
Abstract: Nine thousand and six hundred infants delivered in a maternity hospital were examined for the prevalence of natal and neonatal teeth. The prevalence among this group was noted. The teeth were the normal primary incisors that had erupted prematurely. The crown was normal in shape and size with very little root formation. The histological features were that of an immature tooth.
TL;DR: The urban water problems in Southeast Asian cities are viewed as the consequences of rapid and uncontrolled urbanization and unsutainable development as discussed by the authors, which in turn has resulted in water problems of considerable magnitude.
TL;DR: The number of eggs laid daily by a female Ascaris increased with increase in its length, weight and diameter and decreased with increasing in the worm load.
Abstract: Fifty children aged 6 to 13 years and infected with Ascaris lumbricoides were selected for the study. The number of eggs laid daily by a female Ascaris increased with increase in its length, weight and diameter. Female worms became mature and started laying eggs when they reached a length of 118 mm. Adult female worms measuring 3.7 mm or more in diameter were found to be mature. The minimum weight of a worm producing eggs was 1.1 g. On average the number of eggs produced by the female decreased with increase in the worm load.
TL;DR: The combined epithelial odontogenic tumour represents a hybrid lesion comprising primarily areas of adenomatoid odontogen tumour intermixed with foci of calcifying epithelium intermixture with the innocuous nature of this lesion confirmed.
Abstract: The combined epithelial odontogenic tumour represents a hybrid lesion comprising primarily areas of adenomatoid odontogenic tumour intermixed with foci of calcifying epithelial odontogenic tumour. Five such cases retrieved from the files of the Division of Stomatology, Institute for Medical Research, Kuala Lumpur, and four others from the existing literature were analysed. A mean age of 18.8 years, a female preponderance (66.7%) with a male to female ratio of 1:2 and predilection for the mandible (55.6%) were observed. All cases were treated by conservative surgery and the lack of recurrence confirmed the innocuous nature of this lesion.
TL;DR: Acrylic resin specimens roughened with 80-grit silicon carbide paper exhibited appreciably higher bond strengths compared with different types of tray material and methods of surface preparation.
Abstract: Adhesive bond strength studies for the tray adhesive of an addition vinyl polysiloxane (President) impression material were conducted with an acrylic resin, chromium-plated brass, and plastic trays. Tensile and shear stress studies were performed on the Instron Universal testing machine. Acrylic resin specimens roughened with 80-grit silicon carbide paper exhibited appreciably higher bond strengths compared with different types of tray material and methods of surface preparation.
TL;DR: A new xanthone, 2-(3-hydroxy-3-methylbutyl)-1,3,5,6-tetrahydroxyxanthone was isolated from the heart-wood of Calophyllum inophyllus.
TL;DR: In this article, the authors presented analytical solutions to the near-neutral atmospheric surface energy balance with the new approach of including heat storage in the building substrate for the first time for the case without heat storage effect.
Abstract: Analytical solutions are presented to the near-neutral atmospheric surface energy balance with the new approach of including the participation of heat storage in the building substrate. Analytical solutions are also presented for the first time for the case without heat storage effect. By a linearization process, the governing equations are simplified to a set of time-dependent, linear, first-order equations from which explicit solutions are readily obtainable. The results compare well with those obtained by numerical solutions upon the set without linearization when applied to the tropical city of Kuala Lumpur, Malaysia.
TL;DR: In this article, it is shown that maximum voltage stability in a distribution network is achieved when the system is operated at minimum loss conditions, which is the same as in this paper.
TL;DR: The results suggest the activation of a lipase in the mesocarp by low temperature stress is suggested, and this activation is accompanied by an increase in lipid-soluble phosphorus levels and a decrease in carotene content.
Abstract: Oil palm fruits exposed to temperatures of 15 °C and below showed a significant increase in free fatty acid (FFA) content in the mesocarp. This effect was most pronounced in fruits exposed to 5 °C when FFA levels exceeding 70% of the total oil were observed. The increase in FFA was accompanied by an increase in lipid-soluble phosphorus levels and a decrease in carotene content. Chilling did not have an effect on palm kernel oil. The results suggest the activation of a lipase in the mesocarp by low temperature stress.
TL;DR: The data provide evidence on the differential specificity of IgA binding lectins isolated from seeds of similar as well as distinct Artocarpus species and selectively precipitating human serum IgA1 and colostral sIgA but not IgA2, IgD, IgG and IgM.
TL;DR: In this article, the eburnane skeleton of Kopsia larutensis was extracted to afford six alkaloids, two of which were new, viz eburnaminol and larutensine.
Journal Article•
TL;DR: The overall seroprevalence of 19.8% reported among the main racial groups in Malaysia indicates that sarcocystosis (both the intestinal and muscular forms) may be emerging as a significant food-borne zoonotic infection in the country.
Abstract: Sarcocystis is a tissue coccidian with an obligatory two-host life cycle. The sexual generations of gametogony and sporogony occur in the lamina propria of the small intestine of definitive hosts which shed infective sporocysts in their stools and present with intestinal sarcocystosis. Asexual multiplication occurs in the skeletal and cardiac muscles of intermediate hosts which harbor Sarcocystis cysts in their muscles and present with muscular sarcocystosis. In Malaysia, Sarcocystis cysts have been reported from many domestic and wild animals, including domestic and field rats, moonrats, bandicoots, slow loris, buffalo, and monkey, and man. The known definitive hosts for some species of Sarcocystis are the domestic cat, dog and the reticulated python. Human muscular sarcocystosis in Malaysia is a zoonotic infection acquired by contamination of food or drink with sporocysts shed by definitive hosts. The cysts reported in human muscle resembled those seen in the moonrat, Echinosorex gymnurus, and the long-tailed monkey, Macaca fascicularis. While human intestinal sarcocystosis has not been reported in Malaysia so far, it can be assumed that such cases may not be infrequent in view of the occurrence of Sarcocystis cysts in meat animals, such as buffalo. The overall seroprevalence of 19.8% reported among the main racial groups in Malaysia indicates that sarcocystosis (both the intestinal and muscular forms) may be emerging as a significant food-borne zoonotic infection in the country.
TL;DR: Three new and one previously described species of Bychowskyella Achmerow, 1952 were collected from the gills of four species of freshwater catfish in Peninsular Malaysia.
Abstract: Three new and one previously described species of Bychowskyella Achmerow, 1952 were collected from the gills of four species of freshwater catfish in Peninsular Malaysia. They are Bychowskyella teysmanni n. sp. from Clarias teysmanni (Bleeker, 1857) (Clariidae), Bychowskyella sisoris n. sp. from Glyptothorax major (Boulenger, 1894) (Sisoridae), Bychowskyella baueri n. sp. from Silurichthys hasselti (Bleeker, 1858) (Siluridae), and Bychowskyella tchangi Gussev, 1976 from Clarias macrocephalus Gunther, 1864 (Clariidae). B. teysmanni n. sp. differs from B. tchangi in having two pairs of large marginal hooks. B. sisoris n. sp. is unique in possessing two onchia, while B. baueri n. sp. differs from previously described Bychowskyella species in the structure of the dorsal onchium. C. macrocephalus is a new host record for B. tchangi in Peninsular Malaysia.