Showing papers by "University of Malaya published in 1977"
TL;DR: The presence of suppressor and effector cells for DTH inducible by different routes of antigenic presentation reflects the dynamic balance in the regulation of DTH.
Abstract: Mice injected with 1 X 10(8) sheep red blood cells (SRBC) into the footpad showed high levels of delayed-type hypersensitivity (DTH) to SRBC 4-8 days after the injection. In contrast, mice injected intravenously with 1 X 10(9) SRBC were unresponsive to DTH induction through 1 X 10(8) SRBC injected into the footpad. This suppression of DTH was maintained for at least 6 weeks and was transferable spleen, lymph node and thymus cells to normal syngeneic recipients. Bone marrow cells, on the other hand, did not contain the suppressor cells. The suppression of DTH was antigen-specific in that DTH to chicken red blood cells and contact sensitivity to 2,4-dinitrofluorobenzene was not affected. The suppressor cells were theta-positive and Ig-negative. They appeared in the spleen in optimum number 3-4 days after induction. The suppressor cells affected both the induction and manifestation of DTH. The presence of suppressor and effector cells for DTH inducible by different routes of antigenic presentation reflects the dynamic balance in the regulation of DTH.
84 citations
TL;DR: It was concluded that, in spite of its low metabolic rate, the slow loris had effective responses to moderate cold, and that it was well adapted to a hot climate.
Abstract: Six slow loris were exposed to air temperatures between 10 °C and 40 °C. Rectal temperature was stable (mean, 34.8 °C) at air temperatures between 17 °C and 31 °C; at higher air temperatures, the animals became hyperthermic. Oxygen consumption was minimal at air temperatures of 31.4-36.6 °C; the mean value (0.250 ml O2 g-1 h−1) was only 36 % of the expected level for a eutherian Mammal. The slow loris increased its heat production at lower air temperatures. Thermal polypnea occurred in response to heat, and some of the animals were able to dissipate their entire metabolic heat production by evaporative cooling. The combined thermal conductance of the tissues and haircoat was 73 % of the predicted values. It was concluded that, in spite of its low metabolic rate, the slow loris had effective responses to moderate cold, and that, in addition, it was well adapted to a hot climate.
58 citations
TL;DR: In a comparative study of the reproductive biology ofRain forest tree species, intra-specific genetic variation of isozymes has been demonstrated for the first time in an emergent and an understorey species of rain forest trees.
Abstract: IN the tropical rain forest, many tree species grow close together, and they are apparently equivalent in their edaphic requirements and spatially interchangeable. Most species occur at low density although they may be geographically widespread. No other plant community contains as many species of a single life form as do certain mixed dipterocarp forests of the aseasonal wet lowlands of Malesia1–3. Such a population structure and level of diversity makes it hard to see how speciation has occurred. Spatial isolation of individuals and the abundant, normally hermaphrodite flowers simultaneously available for fertilisation in the canopy of the dipterocarp emergents suggest the possibility of self-fertilisation, but many of the understorey species are dioecious. As part of a comparative study of the reproductive biology of rain forest tree species, intra-specific genetic variation of isozymes has been demonstrated for the first time in an emergent and an understorey species of rain forest trees. Polymorphism is common in both species and there is evidence for short-range spatial heterogeneity in gene frequency and also in leaf morphology.
51 citations
TL;DR: Pentacene films on quartz were prepared by vapour deposition at various substrate temperatures and their absorption spectra measured as discussed by the authors, which showed that the organic films prepared at high substrate temperatures are homogeneous, consisting of fair size crystallites oriented with their abplanes parallel to the substrate surface.
41 citations
TL;DR: It was concluded that the mouse deer is not particularly well adapted to heat or cold, which conforms with its behavior, habitat and distribution.
25 citations
TL;DR: In this paper, the activity coefficients of hydrochloric acid and calcium chloride were derived from electromotive force measurements of cells containing mixtures of mixed-electrolyte solutions at constant ionic strengths.
Abstract: Activity coefficients of hydrochloric acid have been determined from electromotive-force measurements of cells containing mixtures of hydrochloric acid and calcium chloride at constant total ionic strengthsI=0.1, 0.5, 1.0, 2.0, and 3.0 mole-kg−1 at 298.15°K. Interpretations based on Scatchard's and Pitzer's equations indicate that Pitzer's equations probably provide a more convenient guide to the thermodynamic properties of the mixed-electrolyte solutions. Activity coefficients for calcium chloride were derived from these equations.
24 citations
TL;DR: The growth of Liza malinoptera, which is analysed by its morphometric and length–weight relationships, is found to follow closely the so-called cubic law for isometric growth.
Abstract: The growth of Liza malinoptera, which is analysed by its morphometric and length–weight relationships, is found to follow closely the so-called cubic law for isometric growth. The relative condition factor Kn is used to investigate the condition cycle and for maturity studies. Fecundity and ova size are estimated. The fish is a herbivorous iliophage utilising mainly mangrove plant detritus at the first trophic level. Fine particle selection is demonstrated during feeding. Studies on the morphology and histology of its alimentary tract indicate an adaptive correlation with its food and feeding habits.
23 citations
TL;DR: The degradation of acid hydrolysed natural and epoxidized synthetic rubbers with lead tetraacetate and periodic acid have been studied, viscometrically as discussed by the authors, and the results demonstrate that the epoxy content of natural rubber is predominantly located on the rubber backbone.
23 citations
TL;DR: There seems to be no clinical justification for routine jejunal biopsy in infants in whom C.M.P.I. is suspected, and the eight infants without symptoms made satisfactory clinical progress, with adequate weight-gain, on a diet of cow's milk.
22 citations
20 citations
TL;DR: A case of the occurrence of both hypodontia or congenital absence of teeth and supernumerary tooth in the mandibular labial segment and the orthodontic management of the patient was discussed.
Abstract: A case of the occurrence of both hypodontia or congenital absence of teeth and supernumerary tooth in the mandibular labial segment is reported. The supernumerary to simulate the lower central incisor, both for aesthetic purpose and for the maintenance of space. The orthodontic management of the patient was discussed.
TL;DR: The ultrastructure of Sarcocystis sp.
Abstract: The ultrastructure of Sarcocystis sp. from the Malaysian house rat, Rattus rattus diardii, was studied with the electron microscope. The thin, uniformly-dense primary cyst wall had a row of vesicular invaginations which were also seen along the wall of the villi-like projections or cytophaneres. Within the villi were spherical bodies and hollow, curled structures. The ground substance beneath the primary cyst wall extended into the cyst as thin septa or trabeculae separating the tightly-packed zoites into compartments. Merozoites had a double-layered membrane, a conoid, 2 conoidal rings, 22 subpellicular microtubules, 6 rhoptries, 80–100 micronemes, scattered lipid droplets, a sac-like mitochrondrion, beside which was a Golgi apparatus. A micropore was occasionally seen at the anterior third of the zoite whereas the nucleus occupied the posterior third. Metrocytes were few in number and peripheral in location.
TL;DR: In this paper, the hybridization of a series of small ring propellanes is studied in order to arrive at a measure of the strain in these compounds, using the Maximum Overlap Approximation.
TL;DR: In this paper, the activity coefficients of hydrochloric acid in aqueous mixed solutions with magnesium chloride have been determined at 298.15°K from electromotiveforce measurements of the cell Pt, H2(g, 1 atm.)⋎HCl(mA), MgCl2(mB), AgCl ⋎Ag at constant total ionic strengths of 0.1, 0.5, 1.0, 2.0 moles-kg−1.
Abstract: Activity coefficients of hydrochloric acid in aqueous mixed solutions with magnesium chloride have been determined at 298.15°K from electromotiveforce measurements of the cell Pt, H2(g, 1 atm.)⋎HCl(mA), MgCl2(mB)⋎AgCl⋎Ag at constant total ionic strengths of 0.1, 0.5, 1.0, 2.0, and 3.0 moles-kg−1. The data were interpreted in terms of Scatchard's and Pitzer's equations whereupon it was found that the former gave a better fit of the experimental data but the latter were reasonably adequate. Activity coefficients for magnesium chloride in the mixtures were derived using Pitzer's equations.
TL;DR: A rare case of midline cleft lip with the following deformities is presented: partial midline Cleft of the upper lip and a fibro-cystic swelling arising from the left side of the nasal septum and columella.
Abstract: A rare case of midline cleft lip with the following deformities is presented: (a) Partial midline cleft of the upper lip. (b) Cleft alveolus. (c) A fibro-cystic swelling arising from the left side of the nasal septum and columella. (d) A frenulum and a cystic swelling attached to the frenulum and hanging into the mouth by a narrow pedicle.
TL;DR: The toxicities of the four herbicides tested were tested on three aquatic organisms associated with the plant in the aquatic environment —larva of Nymphula responsalis, Rasbora trilineata and Poecilia reticulata, and TOK E-25 has been found to be most toxic, the others being relatively safe.
Abstract: Laboratory trials were performed to screen the potentials of four herbicides — PARAQUAT, DIQUAT, TOK E-25 and DALAPON — for the chemical control of Salvinia molesta. The herbicides were applied as aerial sprays, and their phytotoxic effects were assessed by visual estimation. Paraquat and Diquat have been found to be the more promising. The toxicities of the four herbicides were tested on three aquatic organisms associated with the plant in the aquatic environment —larva of Nymphula responsalis, Rasbora trilineata and Poecilia reticulata. An attempt was made to correlate the toxicological results with the application rates of the herbicides in terms of safety factors. TOK E-25 has been found to be most toxic, the others being relatively safe.
TL;DR: The neurotoxie effect of triethyltin sulphate on neuromicrotubules is further substantiated by its inhibition (in a concentration‐dependent manner) of the specific colchicine‐binding activity of the crude and purified tubulin preparations derived from brain tissue.
Abstract: —
The toxicity of trimethyltin chloride and triethyltin sulphate on animal tissues was assessed by their effects on isolated phrenic nerve-diaphragm preparations. Studies by electron microscopy show that the inhibitory effects of these compounds on the muscular contractility of this tissue are associated with (a) the disruption of mitochondria and disorganisation of muscle fibres and (b) the depletion of neuromicrotubules in the axons of nerves innervating the muscle. The neurotoxie effect of triethyltin sulphate on neuromicrotubules is further substantiated by its inhibition (in a concentration-dependent manner) of the specific colchicine-binding activity of the crude and purified tubulin preparations derived from brain tissue. In addition, both triethyltin sulphate and trimethyltin chloride at a concentration greater than 100 μM completely prevent the normal in vitro assembly of microtubules from tubulin.
TL;DR: Black piedra, an infection of the hair shaft by Piedra hortai, is present in peninsular Malaysia and is known to the indigenous population as‘rambut berbuah’(fruit‐bearing hair).
Abstract: Summary
Black piedra, an infection of the hair shaft by Piedra hortai, is present in peninsular Malaysia and is known to the indigenous population as‘rambut berbuah’(fruit-bearing hair). Thirty-one patients, the majority being from rural areas, were studied. Though most of the patients were aware of the infection they did not seek medical treatment spontaneously, as the fungus causes minimal damage to the hair. Penetration of the fungus beyond the cuticle of the hair shaft was not seen. The source of the fungus was not identified.
TL;DR: Following removal of a significant part of the dentate nucleus and most of the interpositus nucleus in the rat cerebellum degenerated cerebellopontine fibres are shown to end in three fairly restricted regions in the contralateral pontine gray: in the paramedian position, in the middle and in the lateral third.
Abstract: Following removal of a significant part of the dentate nucleus and most of the interpositus nucleus in the rat cerebellum degenerated cerebellopontine fibres are shown to end in three fairly restricted regions in the contralateral pontine gray: in the paramedian position, in the middle and in the lateral third. The three regions are arranged in rostro-caudal longitudinal columns in the caudal three-quarters of the pons and these columns are continuous with one another by regions of scattered degeneration. The fibres appear to end in relation to distal dendrites of the pontine cells.
01 Jan 1977
TL;DR: The authors explored the subject of tax audit and tax evasion in Malaysian taxation environment from the perception of tax practitioners using questionnaire method as a basis, and investigated on the extent of taxpayers' awareness toward their obligation under the self assessment system (SAS).
Abstract: Although the essence of tax audit is to promote voluntary compliance, tax practitioners’ need to understand its meaning and further eliminate intentional noncompliance. In this study, we explore the subject of tax audit and tax evasion in Malaysian taxation environment from the perception of tax practitioners. Using questionnaire method as a basis, we could investigate on the extent of taxpayers’ awareness toward their obligation under the self assessment system (SAS), draw out their experience in tax audits, discover a general method to effectively prevent tax evasion and assess taxpayers’ knowledge on identifying tax evasion transaction. Our study would have an implication for the Inland Revenue Board of Malaysia (IRBM) as it reflects the true phenomenon in Malaysia after the implementation of SAS through the responses gathered from business taxpayers and the tax paying public. It can serve as an indicator for future development of tax compliance in Malaysia.
TL;DR: Standard oxygen consumption and ventilatory frequency were influenced greatly by temperature, e.g. values for stage 6 of L. fluviatilis rose from 24.3 μl g−1 h−1 and 33.0 beats min−1 at 5 °C to 103.8 μlG −1 h −1 and 98.2 beats min −1 at 15 °C.
Abstract: 1. Standard oxygen consumption has been measured during the six stages of metamorphosis in both the anadromous parasitic lamprey, Lampetra fluviatilis, and in its non-parasitic derivative, Lampetra planeri.
2. At 10 °C, the standard rates in larval L. planeri and L. fluviatilis of metamorphosing size were 20.3 and 29.3 μl g−1 h−1 respectively.
3. After a slow rise in oxygen consumption during the initial stages of metamorphosis, the rates reached 50.5 and 60.4 μl g−1 h−1 at stage of 6 of L. planeri and L. fluviatilis respectively.
4. Following the completion of metamorphosis in L. planeri and the development of secondary sexual characters, the mean rate in males rose to 73.3 μl g−1 h−1 compared with a decline in females to 44.1 μl g−1 h−1.
5. Although no circadian rhythm was detectable in the oxygen consumption of larvae, an elevation in the metabolic rate was present during darkness in L. fluviatilis at the end of metamorphosis.
6. Standard oxygen consumption and ventilatory frequency were influenced greatly by temperature, e.g. values for stage 6 of L. fluviatilis rose from 24.3 μl g−1 h−1 and 33.0 beats min−1 at 5 °C to 103.8 μl g−1 h−1 and 98.2 beats min−1 at 15 °C.
7. The results are discussed in the context of the radical changes taking place during metamorphosis and in terms of the differences between larvae and adult and between the life cycles of parasitic and non-parasitic lampreys.
TL;DR: Comparative immunological analyses of proteins from different phylogenetic groups of animals and plants have been useful in assessing taxonomic relationships and measuring genetic homologies among species, especially in the absence of amino acid sequence data.
TL;DR: Short-haired pedigree dogs such as boxers, Dobermanns, dachshunds and bulldogs were generally more frequently infected and showed a higher parasitaemia than longer-hair pedigree dogs, such as Alsatians, spaniels and terriers.
TL;DR: It is shown that primary hepatocellular carcinoma (PHC) is the commonest cancer among the Senoi (a Malaysian aborigine group), and the strong possibility that hepatitis B may be an important etiologic factor in the development of cirrhosis and PHC in theSenoi.
Abstract: Necropsy and clinical data show that primary hepatocellular carcinoma (PHC) is the commonest cancer among the Senoi (a Malaysian aboringine group). The other aboringine tribes do not appear to have this high predilection for liver cancer. In the necropsy series, PHS was present in 10 out of 22 Senoi patients with cirrhosis. All the 22 livers contained hepatocytes that stained with Shikata's orcein stain and specific immunoperoxidase and immunofluorescent stains for hepatitis B antigen (HBAg). This observation raises the strong possibility that hepatitis B may be an important etiologic factor in the development of cirrhosis and PHC in the Senoi. The reason for the high susceptibility of the Senoi for HB virus infection is not clear, and the role of aflatoxin in the pathogenesis of PHC in the Senoi has yet to be determined. That the Senoi are a numerically small community, maintaining their own unique dietary and social customs and living in readily accessible areas in the Malaysian jungle, makes them an ideal population for the study of factors in the etiology of liver cancer.
TL;DR: In this article, the reaction of amino acids with functional groups in natural rubber has been studied by use of tritium labeled glycine as a tracer, and the rate of reaction, in the latex phase, is found to be pH-dependent with optimum rate at about pH 8.
Abstract: The reaction of amino acids with functional groups in natural rubber has been studied by use of tritium labeled glycine as a tracer. The rate of reaction, in the latex phase, is found to be pH-dependent with optimum rate at about pH 8. Reaction is considered to occur with rubber epoxide groups, since the level of incorporation of glycine correlates closely with the epoxide groups concentration. Competitive reactions with other amino acids and the effect of dimedone on glycine incorporation are also reported.
TL;DR: In this paper, the authors present a characterization of the exponential distribution in terms of the means of the left-truncated values of the random variable concerned, which leads to the Cauchy equation just as in the case of the lack of memory characterization.
Abstract: This paper presents a characterization of the exponential distribution in terms of the means of the left-truncated values of the random variable concerned. This characterizing property leads to the Cauchy equation just as in the case of the lack of memory characterization. While the latter characterization assumes somewhat less easily accessible information concerning the probability distribution, the former only requires more readily available information regarding the expected values. The present characterization will be particularly useful in testing exponentiality for a failure model. A similar characterization is given for the geometric distribution.
TL;DR: In this article, the advantages of the m basis as compared to the Wigner (matric) basis are discussed, and the importance of the double antisymmetrization is shown.
Abstract: With the basic equivalent transformation Pσ = ϵ(P)(Pr)−1 the dual bases of symmetric groups can be constructed. The importance of the double antisymmetrization is shown. The advantages of the use of the m basis as compared to the Wigner (matric) basis are discussed.