Displaying publications 1 - 20 of 497 in total

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  1. Dharmalingam SK, Mahadev V
    Med J Malaya, 1970 Dec;25(2):83-90.
    PMID: 4251140
    Matched MeSH terms: Color
  2. Saha N, Tan PY, Tan BH
    Z Morphol Anthropol, 1980;71(1):107-9.
    PMID: 6969497
    1829 school-boys of Singapore comprised of 849 Chinese, 469 Malays and 511 Indians were investigated for the incidence of red-green colour-blindness with Ishihara's plates. The incidence of red-green colour-blindness was found to be 3.8%, 4.5% and 4.5%, respectively in Chinese, Malay and Indian boys. The incidence among the different dialect groups was variable with the highest incidence of red-green colour-blindness among Mandarin speaking group (14.3%), followed by Hainanese speaking (6.7%) and other dialect groups of Chinese (2.8% to 4.5%). The incidence of red-green colour-blindness was higher in the older boys compared with the younger boys when all the three ethnic groups are combined.
    Matched MeSH terms: Color Vision Defects/epidemiology*
  3. Yap HH, Lee CY, Chong NL, Foo AE, Lim MP
    J Am Mosq Control Assoc, 1995 Mar;11(1):128-32.
    PMID: 7616179
    Several parameters on the oviposition site preference of Aedes albopictus were studied, including color, container type, salinity, and water type. Dark-colored glass jars, especially black, blue, and red ones were preferred over light-colored jars. The black-colored ovitrap with a paper strip performed better than other types of containers. Seasoned tap water had the highest egg count when compared with a saline water series. In addition, water that had previously been used for the culture of Ae. albopictus was the most preferred for oviposition. The significance of this study in conjunction with the present Aedes mosquito surveillance and monitoring program is discussed.
    Matched MeSH terms: Color
  4. Raman S, Ramanujam T, Lim CT
    J Obstet Gynaecol Res, 1996 Aug;22(4):375-8.
    PMID: 8870422
    Extensive haemangioma with platelet consumption (Kasabach-Merritt syndrome) is rare. The lesion is usually a single cutaneous cavernous haemangioma similar to that found in our patient. Multiple superficial strawberry naevi were also seen all over the rest of the body. This condition was diagnosed antenatally in this patient with the use of colour Doppler. There is one recent report where the thrombocytopaenia was diagnosed by cordocentesis. Unfortunately the baby developed heart failure with intractable coagulopathy and died 2 days later.
    Matched MeSH terms: Ultrasonography, Doppler, Color
  5. Kaur S
    Sains Malaysiana, 1996;25(2):41-49.
    This study was conducted for 3 main purposes: 1) to determine if there was blue colour deficiency amongst diabetes mellitus (IDDM and NIDDM) patients without retinopathy, 2) to determine if the Dl5 test could be used to detect any colour vision defects amongst diabetics without retinopathy (all previous workers have used FM 100-Hue), and 3) to assess the performance of diabetics without retinopathy in detecting correct colour changes with the urine strip test. Thirty eight non-insulin dependent diabetes mellitus (NIDDM) and 30 insulin-dependent diabetes mellitus (IDDM) patients without retinopathy participated in this study. A control group of 23 normal subjects were also included in the study. Dl5 colour vision test was performed under daylight conditions. Colour dependent urine glucose test (Glukotest) was also performed on all subjects. The study showed that 47.1% of diabetics (47.4% NIDDM and 46.7% IDDM patients) without retinopathy had a blue colour deficiency. Amongst the diabetics with a blue colour deficiency, 25% of diabetics (22% of NIDDM and 28.6% of IDDM patients) failed to accurately match the strip colour with the comparison chart on the bottle.
    Kajian ini dilakukan untuk 3 tujuan: I) untuk menentukan samada terdapat gangguan penglihatan warna biru dalam pesakit diabetes mellitus (IDDM dan NIDDM) tanpa retinopati, 2) untuk menentukan samada ujian penglihatan warna Dl5 boleh digunakan untuk mengesan defek penglihatan warna dalam pesakit diabetes tanpa retinopati (kesemua kajian terdahulu menggunakan ujian FM 100-Hue). dan 3) untuk menilaikan prestasi pesakit diabetik tanpa retinopati dalam mengesan perubahan warna yang betul dengan menggunakan ujian strip urin. Tiga puluh lapan pesakit dengan non-insulin dependent diabetes (NIDDM) dan 30 pesakit dengan insulin dependent diabetes (IDDM) tanpa retinopati menyertai kajian ini. Kumpulan kawalan mengandungi 23 orang subjek yang normal juga terlibat di dalam kajian ini. Ujian penglihatan warna Dl5 dilakukan di bawah cahaya daylight. Ujian glukos urin berasaskan warna (Glukotest) dilakukan ke atas semua subjek. Kajian menunjukkan 47.1% pesakit diabetes (47.4% pesakit NIDDM dan 46.7% pesakit IDDM) tanpa retinopati mengalami defisiensi warna biru. Dalam kumpulan diabetik dengan defisiensi warna biru, 25% pesakit diabetes (22.2% adalah pesakit NIDDM dan 28.6% adalah pesakit IDDM) gagal untuk memadankan dengan tepat warna strip dengan carta perbandingan warna di atas botol.
    Matched MeSH terms: Color; Color Vision Defects; Color Vision
  6. Kaur S, Kulikowski J
    This study was conducted to see if slow test presentations of 1 Hz was detected by the chromatic system and higher rates of flicker of 25 Hz, 33 Hz and 40 Hz were detected by the pure flicker system at lower and higher background luminances. Spectral sensitivity measurements were carried out using a 1.2 degree test spot presented at a rate of 1 Hz, 25 Hz, 33 Hz and 40 Hz on a white background. The background luminance used were 100 td, 250 td, 500 td, 750 td, 1000 td, 2500 td and 4000 td. The study showed that the detection of a 1 Hz test is possible by 2 mechanisms, the chromatic system at high background luminance and the achromatic and chromatic systems at low background luminance. In the case 25 Hz, it is not entirely detected by the 'pure flicker system' and the transient achromatic system might contribute in its detection. Flicker rates of 33 Hz and higher are detected by the pure flicker system.
    Kajian ini dilakukan untuk melihat sama ada presentasi ujian secara perlahan iaitu 1 Hz dikesan oleh sistem kromatik dan ketipan pada kadar yang tinggi, iaitu 25 Hz, 33 Hz dan 40 Hz dikesan oleh sistem ketipan yang tutin pada luminans latar belakang rendah dan tinggi. Pengukuran sensitiviti spektral telah dijalankan dengan menggunakan satu cahaya ujian bulat berukuran 1.2 darjah yang dipersembahkan pada kadar 1 Hz, 25 Hz, 33 Hz dan 40 Hz pada latar belakang putih. Luminans latar belakang yang telah digunakan adalah 100 td, 250 td, 500 td, 750 td, 1000 td dan 4000 td. Kajian ini menunjukkan yang pengesanan ujian 1 Hz adalah melalui 2 mekanisma, mungkin sistem kromatik pada luminans latar belakang yang tinggi dan sistem akromatik dan kromatik pada luminans latar belakang yang rendah. Bagi 25 Hz pula, ia tidak secara keseluruhannya dikesan oleh sistem kelipan yang tutin dan mungkin sistem akromatik transien yang terlibat dalam pengesanannya. kadar ketipan 33 Hz dan lebih darinya adalah dikesan oleh sistem ketipan yang tulin.
    Matched MeSH terms: Color
  7. Sharanjeet-Kaur, Dickinson CM, O'Donoghue E, Murray IJ
    Ophthalmic Physiol Opt, 1997 May;17(3):232-8.
    PMID: 9196665 DOI: 10.1111/j.1475-1313.1997.0_749.x
    The majority of patients with dysthyroid eye disease have an acquired colour vision defect. However, no psychophysical investigation of selective damage to colour or flicker pathways has been carried out. In order to clarify the nature of the visual pathology, we have used a psychophysical technique (spectral sensitivity) to selectively stimulate the chromatic and achromatic mechanisms. Spectral spots of size 1 degree presented at a rate of 1 Hz on a bright 1000 td white background are detected by the chromatic mechanism but a rate of 25 Hz reveals the achromatic mechanism. Fifteen patients (28 eyes) between the ages of 50-70 years were tested. The study showed that all patients had reduced spectral sensitivity, either 1 Hz, 25 Hz or both. The patients with reduced 1 Hz or 25 Hz spectral sensitivity only had a shorter systemic and ocular duration of the condition, had no proptosis, normal intraocular pressures in primary gaze, slightly higher intraocular pressures on upgaze, normal visual field plots and FM 100-Hue error scores higher than the normal age-matched values. The patients with reduced both 1 Hz and 25 Hz spectral sensitivities had a longer systemic and ocular duration of the condition, had proptosis, normal intraocular pressures in primary position, higher intraocular pressures on upgaze and higher FM 100-Hue error scores than the age-matched normals and those in Groups 1 and 2. A total of 50% of patients in Group 3 had defective visual field plots. These data suggest that there is a damage of the large achromatic fibres and small chromatic fibres in dysthyroid eye disease. The mechanism of the damage could be one of ischaemic or mechanical or both.
    Matched MeSH terms: Color Vision Defects/diagnosis*; Color Perception Tests*
  8. Sharanjeet-Kaur, Kulikowski JJ, Carden D
    Ophthalmic Physiol Opt, 1998 Jan;18(1):49-56.
    PMID: 9666910
    The purpose of this study was to optimise the testing paradigm for isolating the contributions of chromatic and achromatic mechanisms to the human spectral sensitivity function. Spectral sensitivity was determined for a test spot size of 1.2 deg presented with various spatial and temporal masks on a large, 10 deg background field of moderate intensity (1000 td) and colour temperature, CT = 2700 K. Sinusoidal temporal presentation (1 Hz) and a masking annulus of between 3 and 10 min of arc surrounding the test spot, was found to be most effective in separating chromatic from achromatic mechanisms. Square-wave (1 Hz) temporal presentation combined with the annulus was slightly less selective. The presence of the annulus did not affect the shape of flicker detection at 25 Hz which is a measure of the luminosity (achromatic) spectral sensitivity function.
    Matched MeSH terms: Color Perception*
  9. Momose K, Yumoto T, Nagamitsu T, Kato M, Nagamasu H, Sakai S, et al.
    Am J Bot, 1998 Oct;85(10):1477-501.
    PMID: 21684899
    Flowerings and flower visitors were observed continuously in alowland dipterocarp forest in Sarawak, Malaysia, for 53 mo in1992-1996. Flower visitors of 270 plant species were observed orcollected, and pollinators were assessed by observing body contact tostigmas and anthers. We recognized 12 categories of pollination systems.Among them, plants pollinated by social bees included the largest numberof species (32%) and were followed by beetle-pollinated species(20%). Pollination systems were significantly related with somefloral characters (flowering time of day, reward, and floral shape), butnot with floral color. Based on the relationships between pollinatorsand floral characters, we described pollination syndromes found in alowland dipterocarp forest. The dominance of social bees and beetlesamong pollinators is discussed in relation to the general floweringobserved in dipterocarp forests of West Malesia. In spite of high plantspecies diversity and consequent low population densities of lowlanddipterocarp forests, long-distance-specific pollinators were uncommoncompared with theNeotropics.
    Matched MeSH terms: Color
  10. Ong KK, Fakhru'l-Razi A, Baharin BS, Hassan MA
    PMID: 10595436
    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.
    Matched MeSH terms: Color
  11. Tan SS, Aminah A, Mohd Suria Affandi Y, Atil O, Babji AS
    Int J Food Sci Nutr, 2001 Jan;52(1):91-8.
    PMID: 11225183
    Physico-chemical and sensory characteristics of frankfurters prepared with three types of palm fats (PF60: 40, PF70: 30 and PF80: 20) and palm olein (POo) at 20 and 25% of fat levels were studied. Incorporation of different fats at 20 and 25% did not affect the cooking yields of the frankfurters. Frankfurters incorporated with 25% POo showed the highest value of water-holding capacity (WHC) among eight formulations. The frankfurters containing POo showed the least cooking loss compared to those with palm fats. The incorporation of different type and level of fats resulted in significant changes in the colour (lightness, redness, yellowness) of frankfurters. Texture profiles of both raw and cooked frankfurters were found to be altered by the blending of different type and level of fats. In raw frankfurters, hardness for frankfurters mixed with palm fats were significantly higher than the one with POo but greater values for cohesiveness was observed in raw frankfurters blended with POo. Lowest chewiness was demonstrated by frankfurters mixed with 20% POo. Grilling increased the hardness values of all frankfurters. Contrary to the raw counterparts, cooked frankfurter with POo was the hardest among all formulations. Cohesiveness and chewiness was also found to be significantly higher for cooked frankfurters mixed with POo. Raw frankfurters with fat content of 25% showed greater value in hardness than those of 20%. However, there were no significant differences (P > 0.05) observed for all the texture profile attributes in cooked frankfurters due to fat levels. In sensory evaluation, frankfurters prepared with POo were found to be most acceptable by consumer panels as they scored the highest for hardness rating, chicken flavour, oiliness and overall acceptance attributes.
    Matched MeSH terms: Color
  12. Shah RP, Ding ZP, Ng AS, Quek SS
    Singapore Med J, 2001 Oct;42(10):473-6.
    PMID: 11874151
    Rupture of the sinus of valsalva (RSOV) is an uncommon condition with a variety of manifestations ranging from an asymptomatic murmur to cardiogenic shock. This retrospective 10-year review (1985-1995) of 18 patients from a single institution revealed that 6 (33%) were female and 12 (67%) were male with a mean age of 37.6 +/- 13.4 years and that 72% were Chinese by ethnic descent with the remaining 28% being Malay. Eight patients (44.4%) presented with an asymptomatic murmur, 4 (22.2%) with acute chest pain, 4 (22.2%) with mild heart failure, 2 (11.1%) with severe heart failure, and 2 (11.1%) with cardiogenic shock. Rupture of the right aneurysmal coronary cusp (RCC) made up 15 (83.3%) while those of the non-coronary cusp (NCC) made up the remaining. Most of the RCC ruptures were directed into the right ventricle and all of the NCC ruptures were into the right atrium. Ventricular septal defects (VSDs) were found in 9 (50%) of the patients, (although detected by echocardiography in only one third of those patients), aortic regurgitation in 6 (33.3%) and aortic valve vegetations in 2 (11.1%). Echocardiography was found to be accurate in diagnosing RSOVs with 100% diagnostic accuracy after 1990 with four misdiagnoses before 1990. Of these four patients, two were misdiagnosed as having VSDs, one as having a coronary arteriovenous fistula and one as having a patent ductus arteriosus. The anatomical structure of the "windsock" was seen in 64% of the patients who were correctly diagnosed. The pattern of colour flow and spectral Doppler was seen in all patients and helped to localise the site of rupture and the direction of flow. In summary, echocardiography is a simple and accurate way of diagnosing and defining RSOVs and is the imaging modality of choice.
    Matched MeSH terms: Echocardiography, Doppler, Color*
  13. Kok, T.C., Ong, S.T.
    Ann Dent, 2001;8(1):-.
    MyJurnal
    The purpose of this study is to assess the effectiveness of C02 laser in relieving symptoms associated with Oral lichen planus (aLP) and lichenoid lesions (aLL) and the event of healing. Six patients were selected for this study with 13 sites treated. Each lesion was ablated with C02 laser and the wound allowed to heal undisturbed. Prior to treatment, 4 patients had both unprovoked and provoked pain and 2 patients rated for provoked pain only. After laser ablation, five out of six patients treated recorded no pain / 0 pain score. One month post-laser, the treated area was almost the same colour as the surrounding normal mucosa and soft in texture in all but one patient in which there was some fibrosis and residual plaque-like patch. Weconclude that the use of C02 laser in the treatment of aLP and aLL shows positive results in relieving symptoms associated with these lesions.
    Matched MeSH terms: Color
  14. Qudsieh HY, Yusof S, Osman A, Rahman RA
    J Agric Food Chem, 2002 Mar 13;50(6):1615-8.
    PMID: 11879045
    A study was conducted to determine the effect of sugarcane maturation on the contents of chlorophyll, tannin, and polyphenol oxidase (PPO) activity and on color change of sugarcane juice. The maturation period of the cane studied was between 3 and 10 months after planting. Different parts of the cane, namely, the top, middle, and bottom portions, were analyzed. Results obtained indicated that there were significant (P < 0.01) decreases in total chlorophyll a and b and tannin contents during maturity followed by slower rates of decrease of both parameters at the end of maturity stages. There were no significant differences (P > 0.05) in chlorophyll and tannin contents between the middle and bottom portions. On the other hand, the top portion of the stem had a significantly (P < 0.01) lower concentration of chlorophyll and a significantly (P < 0.01) higher content of tannin. PPO activity of sugarcane juice was determined using chlorogenic acid as a substrate. There was a highly significant difference (P < 0.01) in PPO activity of cane juice during maturity. PPO activity was high at the early development stage, decreased during maturation, and then remained relatively constant at the end of maturity. PPO activity was higher when chlorogenic acid was used as substrate. There were also significant differences (P < 0.01) in juice color (L*, a*, b* values) from different portions at different maturity stages. At the early stages, the color of extracted juice was dark, and then the juice turned to yellowish green during maturity. The decrease in green color or the increase in the yellow color could be associated with the decline in chlorophyll. The overall color change (DeltaE) at maturity indicated that the color of the middle and bottom portions was lower than that of the top portion.
    Matched MeSH terms: Color*
  15. Najafpour GD, Shan CP
    Bioresour Technol, 2003 Jan;86(1):91-4.
    PMID: 12421015
    Kinetic studies of the enzymatic hydrolysis of molasses were conducted using glucoamylase. Central Sugar Refinery SDN BHD contains 13-20% glucose. The molasses was diluted and the kinetic experiments were conducted at 67 degrees C with 100-1000 mg/l of glucoamylase. The glucose contents of the molasses were enhanced after hydrolysis of molasses solution with 1000 mg/l glucoamylase. A Lineweaver-Burk plot was obtained based on enzyme kinetic data. The rate constant, Km and maximum reaction rate, Vmax for 500 mg/l of glucoamylase were 100 mmol/l (18 g/l) and 5 mmol/l min (0.9 g/l min), respectively. The maximum reaction rate, Vmax for 1000 mg/l of glucoamylase was doubled, to 100 mmol/l (18 g/l) and the rate constant, Km was the same for 500 mg/l of glucoamylase. The substrate inhibition model was noncompetitive based on the resulting Lineweaver-Burk plot for enzyme concentration of 500 and 1000 mg/l.
    Matched MeSH terms: Color
  16. Ravindran J, Shamsuddin K, Selvaraju S
    Med J Malaysia, 2003 Mar;58(1):37-53.
    PMID: 14556325
    Identification of pregnancies that are at greater than average risk is a fundamental component of antenatal care. The objective of this study was to assess the level of appropriate management and outcomes among mothers with hypertensive disorders of pregnancy, postdates and anemia in pregnancy, and to determine whether the colour coding system had any effect on the maternal mortality ratios. A retrospective follow-through study confined to users of government health services in Peninsular Malaysia was carried out in 1997. The study areas were stratified according to their high or low maternal mortality ratios. The study randomly sampled 1112 mothers out of 8388 mothers with the three common obstetric problems in the selected study districts. The study showed that the prevalence of anemia, hypertensive disorders in pregnancy and postmaturity among mothers with these conditions were according to known international standards. There was no significant difference in the colour coding practices between the high and low maternal mortality areas. Inappropriate referrals were surprisingly lower in the areas with high maternal mortality. Inappropriate care by diagnosis and by assigned colour code were significantly higher in the areas with high maternal mortality. The assigned colour code was accurate in only 56.1% of cases in the low maternal mortality areas and in 55.8% of the cases in the high maternal mortality areas and these two areas did not differ significantly in their accurate assignment of the colour codes. The colour coding system, as it exists now should be reviewed. Instead, a substantially revised system that takes cognisance of evidence in the scientific literature should be used to devise a more effective system that can be used by health care personnel involved in antenatal care to ensure appropriate level of care and referrals.
    Matched MeSH terms: Color*
  17. Sharanjeet-Kaur, O'Donaghue E, Murray IJ
    Clin Exp Optom, 2003 Nov;86(6):385-9.
    PMID: 14632615 DOI: 10.1111/j.1444-0938.2003.tb03083.x
    BACKGROUND: This prospective study was undertaken to investigate whether spectral sensitivity can be useful in determining the prognosis of fellow eyes of eyes with macular holes.
    METHODS: Spectral sensitivity measurements using a one degree test spot presented at a rate of 1 Hz and 25 Hz on a bright (1000 td) white background were carried out on 10 patients aged between 67 and 74 years (mean age 70.3 +/- 2.6 years). Each patient had a full thickness macular hole in one eye and a normal contralateral fellow eye. The spectral sensitivity measurements were made with eccentric fixation in the eyes with macular holes and with central fixation in the normal fellow eye. A year later, the patient files were reviewed to look at the patient's ocular condition. Another 10 subjects between the ages of 50 and 80 years (mean age 69.5 +/- 4.2 years) were also seen. These control group subjects had visual acuities of 6/9 or better with minimal ocular media changes and no ocular or systemic pathology that could affect colour vision.
    RESULTS: The 1 Hz and 25 Hz spectral sensitivities of all patients were reduced for both eyes. Despite the good eye without a macular hole having a VA of 6/6, the spectral sensitivity was similar to that of the eye with the macular hole and markedly reduced visual acuity.
    CONCLUSION: The present investigation enabled us to examine the chromatic and achromatic mechanisms by testing spectral sensitivity at 1 Hz and 25 Hz, respectively. The data revealed that both chromatic and achromatic processing could be damaged in the eye with a macular hole. Surprisingly, the spectral sensitivities of both 1 Hz and 25 Hz are equally reduced in the good fellow eye with no macular hole. A one-year follow-up showed that two of the 10 patients (20 per cent) did eventually develop a macular hole in the normal fellow eye. This indicates that there is some subclinical foveal dysfunction in the normal fellow eye, the nature of which is unclear.
    Study site: Manchester Royal Eye Hospital (MREH), United Kingdom
    Matched MeSH terms: Color Perception*
  18. Tun M, Shuaib IL, Muhamad M, Mat Sain AH, Ressang AS
    Malays J Med Sci, 2004 Jan;11(1):75-80.
    PMID: 22977363
    The incidence of deep vein thrombosis is believed to be rare in Asians. During recent years, a few reports have appeared with high incidence in orthopaedic patients comparable to Western studies. This study was carried out to find out the incidence of post-operative deep vein thrombosis (DVT) after major surgical procedures in general surgical patients in an Asian population. In a prospective study of 45 consecutive Asian patients after major general surgery, colour-flow duplex scan of the legs as an initial screening was done twice within two weeks. Mean age of the patients was 54 years 5 months and 87% of patients were included in the moderate and high risk group for deep vein thrombosis. Ascending venography was used to confirm deep vein thrombosis on patients with equivocal or positive results from colour flow duplex scan. One patient showed positive evidence of post-operative deep vein thrombosis on colour flow duplex scan which was further confirmed by ascending venography; giving an incidence of 2.2%. The incidence of post-operative deep vein thrombosis in general surgical patients is lower than the Western studies.
    Matched MeSH terms: Color
  19. Sharanjeet-Kaur, Mursyid A, Kamaruddin A, Ariffin A
    Clin Exp Optom, 2004 Jul;87(4-5):339-43.
    PMID: 15312037 DOI: 10.1111/j.1444-0938.2004.tb05064.x
    BACKGROUND: Occupational exposure to various neurotoxic chemicals has been shown to be associated with colour vision impairment. It seems that this can occur at low exposure levels, sometimes well below the recommended occupational threshold limits. This study was undertaken to determine the effect of exposure to petroleum derivatives (polyethylene, polystyrene) and solvents (perchloroethylene) on colour perception.
    METHODS: Colour vision was assessed using the Ishihara plates, the D-15 test and the Farnsworth Munsell 100 Hue test. Two factories using petroleum derivatives and three dry cleaning premises were chosen at random. A total of 93 apparently healthy employees were recruited from the five workplaces. Two age-matched control groups comprising 56 people, who were support staff of the university with no exposure to petroleum, solvents or their derivatives, were also recruited.
    RESULTS: All subjects passed the Ishihara test, showing that none had a congenital red-green defect. Some of the exposed employees failed the D-15 and had abnormally high FM100 Hue scores. All control subjects passed all the colour vision tests. The D-15 test showed that 28 per cent (26 of 93) of exposed employees had a colour vision defect whereas the FM 100 Hue test found that 63 per cent (59 of 93) had a colour vision defect. Most defects were of the blue-yellow type (22.6 per cent) when using the D-15 test. However, with the FM 100 Hue test, most defects were of the non-polar type with no specific axis (50.5 per cent). Mean total error scores calculated from the FM100 Hue test for exposed employees were statistically significantly higher than those of the control subjects.
    CONCLUSION: Employees directly exposed to petroleum derivatives and solvents have a higher risk of acquiring colour vision defects compared to subjects who are not.
    Study sites: Factories; the control subjects were tested at the Optometry Clinic in Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia.
    Matched MeSH terms: Color Perception/drug effects*; Color Perception Tests
  20. Chua KB, Chua IL, Chua IE, Chua KH
    PMID: 15689073
    A study was made of the oviposit behavior of gravid female Aedes mosquitos in man-made habitats under field conditions. The study showed that the gravid female Aedes mosquitos preferred containers with relatively easy access but not too open to external environmental influence. The dark surface of the containers served as the initial and long-range attractant to the breeding sites. Volatile chemicals generated by the decaying vegetation in the container may serve as a close-range attractant. Finally, the water quality and the quantity of 'food' derived from decaying vegetative matter in the water determined the amount of eggs deposited in each container. The study confirmed previous findings that each gravid female Aedes mosquito had the tendency to lay her eggs in more than one container. However, the results of the study suggests that under favorable conditions, each gravid female Aedes mosquito could be encouraged to lay all her eggs in a single breeding site.
    Matched MeSH terms: Color
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