Displaying publications 101 - 120 of 191 in total

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  1. Fulltext A monoclinic polymorph of 4-(2H-1,3-benzodioxol-5-yl)-1-(4-methyl-phen-yl)-1H-pyrazol-5-amine
    Jotani MM, Gajera NN, Patel MC, Sung HH, Tiekink ER
    Acta Crystallogr E Crystallogr Commun, 2015 Oct 1;71(Pt 10):1121-4.
    PMID: 26594387 DOI: 10.1107/S2056989015016023
    The title compound, C17H15N3O2, is a monoclinic polymorph (P21/c with Z' = 1) of the previously reported triclinic (P-1 with Z' = 2) form [Gajera et al. (2013 ▸). Acta Cryst. E69, o736-o737]. The mol-ecule in the monoclinic polymorph features a central pyrazolyl ring with an N-bound p-tolyl group and a C-bound 1,3-benzodioxolyl fused-ring system on either side of the C atom bearing the amino group. The dihedral angles between the central ring and the N- and C-bound rings are 50.06 (5) and 27.27 (5)°, respectively. The angle between the pendent rings is 77.31 (4)°, indicating the mol-ecule has a twisted conformation. The five-membered dioxolyl ring has an envelope conformation with the methyl-ene C atom being the flap. The relative disposition of the amino and dioxolyl substituents is syn. One of the independent mol-ecules in the triclinic form has a similar syn disposition but the other has an anti arrangement of these substituents. In the crystal structure of the monoclinic form, mol-ecules assemble into supra-molecular helical chains via amino-pyrazolyl N-H⋯N hydrogen bonds. These are linked into layers via C-H⋯π inter-actions, and layers stack along the a axis with no specific inter-actions between them.
  2. Culturable pathogenic bacteria in ticks parasitizing farm animals and rodents in Malaysia
    Loong SK, Lim FS, Khoo JJ, Lee HY, Suntharalingam C, Ishak SN, et al.
    Trop Biomed, 2020 Sep 01;37(3):803-811.
    PMID: 33612793 DOI: 10.47665/tb.37.3.803
    Ticks are vectors of bacteria, protozoa and viruses capable of causing serious and life threatening diseases in humans and animals. Disease transmission occurs through the transfer of pathogen from tick bites to susceptible humans or animals. Most commonly known tick-borne pathogens are obligate intracellular microorganisms but little is known on the prevalence of culturable pathogenic bacteria from ticks capable of growth on artificial nutrient media. One hundred and forty seven ticks originating from dairy cattle, goats and rodents were collected from nine selected sites in Peninsular Malaysia. The culture of surfacesterilized tick homogenates revealed the isolation of various pathogenic bacteria including, Staphylococcus sp., Corynebacterium sp., Rothia sp., Enterococcus faecalis, Klebsiella pneumoniae, Escherichia coli and Bacillus sp. and its derived genera. These pathogens are among those that affect humans and animals. Findings from this study suggest that in addition to the regular intracellular pathogens, ticks could also harbor extracellular pathogenic bacteria. Further studies, hence, would be needed to determine if these extracellular pathogens could contribute to human or animal infection.
  3. History and Current Status of Cardiac Anesthesia in Singapore
    Phoon PHY, MacLaren G, Ti LK, Tan JSK, Hwang NC
    J Cardiothorac Vasc Anesth, 2019 Dec;33(12):3394-3401.
    PMID: 30131218 DOI: 10.1053/j.jvca.2018.07.018
    Singapore is a small Southeast Asian island city-state located at the tip of the Malay peninsula with a population of 5.61 million people. It was a former British colony that went on to become a part of Malaysia before gaining independence in 1965. Since then, Singapore has developed tremendously from a small fishing village into the region's medical hub. This article will explore the roots of cardiac anesthesia in Singapore and how it has developed into a subspecialty today.
  4. A contrast stretching bilateral closing top-hat Otsu threshold technique for crack detection in images
    Sim KS, Kho YY, Tso CP, Nia ME, Ting HY
    Scanning, 2013 Mar-Apr;35(2):75-87.
    PMID: 22777599 DOI: 10.1002/sca.21037
    Detection of cracks from stainless steel pipe images is done using contrast stretching technique. The technique is based on an image filter technique through mathematical morphology that can expose the cracks. The cracks are highlighted and noise removal is done efficiently while still retaining the edges. An automated crack detection system with a camera platform has been successfully implemented. We compare crack extraction in terms of quality measures with those of Otsu's threshold technique and the another technique (Iyer and Sinha, 2005). The algorithm shown is able to achieve good results and perform better than these other techniques.
  5. Distribution of pathogenic Leptospira in environmental water and soils of selected recreational forests in Perak, Malaysia
    Yap ML, Chew LJ, Pritpal Singh SS, Sekawi Z, Chee HY, Ong HKO, et al.
    Trop Biomed, 2021 Jun 01;38(2):122-128.
    PMID: 34172700 DOI: 10.47665/tb.38.2.047
    Leptospirosis is an emerging zoonotic disease endemic in tropical regions. Aiming at assessing the potential infection risks via recreational exposure, the molecular prevalence of pathogenic Leptospira in 14 amenity forests in five selected districts of the state of Perak was determined. Water and soil samples along streams and waterfalls were subjected to culture of leptospires and the pathogenic Leptospira spp. was detected by lipL32-based polymerase chain reaction (PCR). Twenty out of 154 samples (13%) that tested positive for leptospires were mostly soils and still water recorded with tolerable temperatures (22.2- 26.5°C) and pHs (5.73-6.70). The localised prevalence was highly varied among eight positive forests (6.7-41.7%), particularly higher in Kampar and Kinta districts which are the more populated urban areas. The importance of public health surveillance should not be underrated given the high prevalence of Leptospira spp. in forests in close proximity to indigenous settlements, even where the places are clean. Overall, this study discovered a wide distribution of pathogenic Leptospira spp. in recreational areas.
  6. A seven-year retrospective analysis of the clinicopathological and mycological manifestations of fungal rhinosinusitis in a single-centre tropical climate hospital
    Goh LC, Shakri ED, Ong HY, Mustakim S, Shaariyah MM, Ng WSJ, et al.
    J Laryngol Otol, 2017 Sep;131(9):813-816.
    PMID: 28841131 DOI: 10.1017/S0022215117001505
    OBJECTIVE: To evaluate the clinicopathological and mycological manifestations of fungal rhinosinusitis occurring in the Tengku Ampuan Rahimah Hospital, in Klang, Malaysia, which has a tropical climate.

    METHODS: Records of patients treated from 2009 to 2016 were analysed retrospectively. Data from the records were indexed based on age, gender, clinical presentations, symptom duration, clinical signs and mycological growth.

    RESULTS: Of 80 samples, 27 (33.75 per cent) had fungal growth. Sixteen patients were classified as having non-invasive fungal rhinosinusitis and 11 as having invasive fungal rhinosinusitis. The commonest clinical presentation was nasal polyposis in non-invasive fungal rhinosinusitis patients (p < 0.05) and ocular symptoms in invasive fungal rhinosinusitis patients (p < 0.05). The commonest organism was aspergillus sp. (p < 0.05) in non-invasive fungal rhinosinusitis and mucorales in invasive fungal rhinosinusitis.

    CONCLUSION: There is an almost equal distribution of both invasive and non-invasive fungal rhinosinusitis, as seen in some Asian countries. Invasive fungal rhinosinusitis, while slightly uncommon when compared to non-invasive fungal rhinosinusitis, is potentially life threatening, and may require early and extensive surgical debridement. The clinical presentation of nasal polyposis was often associated with non-invasive fungal rhinosinusitis, whereas ocular symptoms were more likely to be associated with invasive fungal rhinosinusitis.

  7. Fulltext Effect of supplementary private health insurance on inpatient utilisation: Evidence from Malaysia
    Balqis-Ali NZ, Jailani AS, Fun WH, Jawahir S, Sararaks S, Lee GHY
    Heliyon, 2023 Mar;9(3):e14025.
    PMID: 36879958 DOI: 10.1016/j.heliyon.2023.e14025
    Supplementary private health insurance (PHI) provides better access to healthcare, improves health outcomes, potentially lowers the costs for health systems and supports the social security system. Improperly regulated PHI, however, may aggravate inequity of access towards preferential care and encourage moral hazard among PHI purchasers, altering the health-seeking behaviour, which is often observed through the pattern of health care utilisation. We investigated the effect of PHI ownership on private inpatient care utilisation, its frequency of admission and length of stay by conducting secondary data analysis of the Malaysian National Health Morbidity Survey (NHMS) 2015 data, a nationally representative community health survey. Malaysian adults 18 years of age and above who utilised inpatient healthcare facilities were included. In this cross-sectional study, we addressed the endogeneity effect of health insurance by employing instrumental variable estimation and a two-stage residual inclusion analysis. We found a significant increase in private inpatient utilisation among those who owned PHI compared to those who did not (β = 4.39, p 
  8. Fulltext Clinical features and epidemiology of chikungunya infection in Singapore
    Ng KW, Chow A, Win MK, Dimatatac F, Neo HY, Lye DC, et al.
    Singapore Med J, 2009 Aug;50(8):785-90.
    PMID: 19710977
    Chikungunya is a re-emerging mosquito-borne viral infection that has spread from East Africa to Indian Ocean islands and re-emerged in India since 2004. In Malaysia, chikungunya re-emerged after a hiatus of seven years, causing a localised outbreak in a north-western coastal town in 2006 and subsequently widespread outbreaks in 2008. Since the first local outbreak of chikungunya in Singapore in January 2008, chikungunya infections have been increasingly reported in Singapore. In this case series, five patients aged 37-62 years, with chikungunya infection confirmed in August 2008, were reported. Three of the five were male, and only one had medical comorbidities. Two had a travel history to Johor, Malaysia, where local outbreaks of chikungunya had been reported. Fever, arthralgia and rash were the most common symptoms. Fever lasted four to five days while viraemia lasted four to 11 days, persisting two to three days after defervescence in three patients. A biphasic pattern of fever was observed in two patients. Leucopenia was noted in all patients, while mild thrombocytopenia and transaminitis occurred in three of five patients. Two patients had persistent polyarthralgia at two to three weeks after the onset of symptoms. Fever, arthralgia and rash should prompt consideration of acute chikungunya in Singapore. While taking the travel history, doctors should be mindful that indigenous chikungunya cases can occur.
  9. Genetic Structure of Ganoderma boninense Populations Associated with Oil Palm at Neighboring Fields with Different Planting Ages in Malaysia
    Wong WC, Goh YK, Wong CK, Goh YK, Marzuki NF, Choo CHY, et al.
    Plant Dis, 2024 Jul;108(7):1982-1986.
    PMID: 38937876 DOI: 10.1094/PDIS-07-23-1426-SC
    Ganoderma boninense is a basidiomycete pathogen of African oil palm (Elaeis guineensis) and the causal agent of basal stem rot (BSR) disease, which is the most destructive fungal disease of oil palm in Southeast Asia. The disease is fatal for infected palms and can result in 50 to 80% losses in oil yields because of a reduction in productive life span and a yield decline of infected oil palms. In this study, G. boninense isolates collected from different locations and planting blocks with different palm ages were molecularly characterized using microsatellite genotyping. Results showed high pathogen genetic diversity (He = 0.67 to 0.74) among planting blocks and between oil palm estates. Two nearby planting blocks with similar planting ages (i.e., 1999 and 2001) had a similar percentage of BSR incidence (>20%) but showed distinct Ganoderma genetic structure as detected using STRUCTURE. Similar results were obtained from another trial site where planting blocks differing in planting age but located only less than 1 km apart showed a diverse genetic background. The pathogen genetic admixture of the oldest planting (>30% BSR incidence) differed significantly from the younger planting (1.8 to 2.8% BSR incidence, breeding trial block), suggesting that the host-pathogen genotype interaction may impact the Ganoderma genetic variation over time. The genetic structure of G. boninense, as revealed in this study, implies positive selection resulting from the pathogen genetic variation, host-pathogen interaction, and possible introductions of novel genetic variants (through spores) from adjacent plantings. These findings offer new insights into the genetic changes of G. boninense over time. The information is essential to design disease management strategies and breeding for BSR resistance in oil palm.
  10. Cgl-SLT2 is required for appressorium formation, sporulation and pathogenicity in Colletotrichum gloeosporioides
    Yong HY, Bakar FD, Illias RM, Mahadi NM, Murad AM
    Braz J Microbiol, 2013 Dec;44(4):1241-50.
    PMID: 24688518
    The mitogen-activated protein (MAP) kinase pathways has been implicated in the pathogenicity of various pathogenic fungi and plays important roles in regulating pathogenicity-related morphogenesis. This work describes the isolation and characterization of MAP kinase gene, Cgl-SLT2, from Colletotrichum gloeosporioides. A DNA sequence, including 1,633 bp of Cgl-SLT2 open-reading frame and its promoter and terminator regions, was isolated via DNA walking and cloned. To analyze gene function, a gene disruption cassette containing hygromycin-resistant gene was constructed, and Cgl-SLT2 was inactivated via gene deletion. Analysis on Cgl-slt2 mutant revealed a defect in vegetative growth and sporulation as compared to the wild-type strain. When grown under nutrient-limiting conditions, hyperbranched hyphal morphology was observed in the mutant. Conidia induction for germination on rubber wax-coated hard surfaces revealed no differences in the percentage of conidial germination between the wild-type and Cgl-slt2 mutant. However, the percentage of appressorium formation in the mutant was greatly reduced. Bipolar germination in the mutant was higher than in the wild-type at 8-h post-induction. A pathogenicity assay revealed that the mutant was unable to infect either wounded or unwounded mangoes. These results suggest that the Cgl-SLT2 MAP kinase is required for C. gloeosporioides conidiation, polarized growth, appressorium formation and pathogenicity.
  11. Fulltext Mini review: surveillance of Lyme borreliosis in Southeast Asia and method of diagnosis
    Teh KJ, Tang HY, Lim LS, Pung HS, Gan SY, Lai NS
    Eur Rev Med Pharmacol Sci, 2023 May;27(10):4378-4385.
    PMID: 37259718 DOI: 10.26355/eurrev_202305_32443
    Lyme borreliosis is caused by the Gram-negative spirochetes Borrelia spp., particularly Borrelia burgdorferi sensu lato complex. The disease is transmitted through the bite of the infected black-legged Ixodes tick. Lyme borreliosis extensively occurs in the Northern Hemisphere, mainly in the United States. Lyme borreliosis cases are also detected in Asian countries including Korea, Nepal, China, Taiwan, and Japan. However, there is an inadequate understanding of Lyme borreliosis in the Southeast Asian region. Hence, this review aims to provide a brief update on the prevalence of Lyme borreliosis infection in Southeast Asia based on the latest literature on this issue. Lyme borreliosis has been discovered in human serum in Indonesia, Malaysia, and Singapore. The human serum samples were mainly examined with ELISA test using Borrelia spp. IgG and IgM antigens. Borrelia spp. also has been detected in ticks found on host animals such as Sundamys muelleri and Python in Malaysia, Thailand, and Laos. Polymerase chain reaction (PCR) is used to detect the presence of Borrelia DNAs in the samples. The published studies have demonstrated that Borrelia spp. exists in Southeast Asia and although the incidence is relatively low, it is believed that Lyme disease cases are under-reported.
  12. Investigations of clinical characteristics and inflammatory markers of febrile seizures induced by coronavirus infection
    Zhao L, Wu HY, Xie D, Mo LM, Yang FF, Gao Y, et al.
    Trop Biomed, 2023 Dec 01;40(4):439-443.
    PMID: 38308831 DOI: 10.47665/tb.40.4.009
    The study of children who experienced with febrile seizures(FS) as a result of COVID-19 infection to gain insight into the clinical characteristics and prognosis of neurological damage, with the aim of improving prevention, diagnosis, and the treatment of neurological complications. This study investigated the clinical features of 53 children with FS who were admitted to Sanya Women and Children's Hospital from December 1, 2022, to January 31, 2023. The results indicated that the duration of convulsion in the case and control group was 7.90±8.91 and 2.67±1.23 (minutes) respectively. The analysis reveals that convulsions occurred within 24 hours in 39 cases (95.12%) of the case group, and in 8 cases (66.7%) of the control group. The difference was statistically significant (P<0.05). Additionally, the case group presented lower counts of WBC and NEU compared to the control group (p<0.05). The findings indicate that convulsions manifest at earlier stages of COVID-19 in children and the last longer than in the control group. It is therefore crucial for healthcare workers to remain attentive to patients with COVID-19 who report fever within 24 hours, and act promptly to implement preventive measures, particularly in cases of prolonged fever. It is essential to integrate the clinical manifestation, particularly convulsions, and the continuous numerical changes of inflammatory factors to assess COVID-19 linked with febrile seizures. In addition, larger-scale multi-center and systematic research are necessary to aid clinicians in monitoring neuropathological signals and biological targets, enabling more equitable diagnosis and treatment plans.
  13. Prevalence and correlates of self-reported depression in Malaysian patients with rheumatoid arthritis
    Chow SK, Guan YK, Chong HY, Zainal NZ, Yeap SS
    Malaysian Journal of Psychiatry, 2002;10(2):9-14.
    Objectives: To determine the prevalence of self-reported depression among Malaysian patients with rheumatoid arthritis (RA) and to study the correlates and independent predictors for depression. Methods: The Hospital Anxiety and Depression Scale (HADS) questionnaire wasused to assess depressive symptoms. Disease activity was determined by theduration of morning stiffness, visual analogue scale for pain and fatigue, numberof swollen/tender joint and the modified disease activity score (DAS). The Health Assessment Questionnaire (HAQ) was used to assess the patients' functionalstatus. Results: Depression was recorded in 17.2% of the 93 patients. Painful joints(p<0.001), active disease (p<0.001) and poor joint function (p<0.001) correlatedsignificantly with depression. Poor functional status assessed by the HAO was themost significant Independent predictor for depression in RA patients, (OR=5.4,p=0.028). Conclusion: The prevalence of depression In this cohort of Asian RA patients was17.2%. Painful joints and functional disability were associated with a higherIncidence of depression. RA Patients with severe functional disability should beassessed for depression that may need to be treated Independently.
  14. Fulltext A qualitative study among youth in Malaysia: What drives the purchase of roasted chicken products by young people seeking a better quality of life?
    Pt E, H Y, Y A, A A, J SN
    Heliyon, 2023 May;9(5):e15819.
    PMID: 37215784 DOI: 10.1016/j.heliyon.2023.e15819
    This study was aimed to assess internal and external factors related to youths' consumption behavior towards roasted chicken products. Qualitative interview was conducted with 30 selected respondents aged 15-20, 21-25 and 26 to 30 from a university and two high schools at Serdang, Selangor. An audio recorder was used to gather qualitative data over two months. A thematic content analysis was applied to identify the needed information, comprising of transcription, coding and theme development. Results disclosed that respondents in this study implied physiological attributes (delicious, tastiness, crispy texture, good flavour, brown colour, smoky aroma, own eating preference), personality attributes (availability, good hygiene, health concern), reference groups (friends, family members) and culture (family lifestyle, early life feeding behaviour) as significant factors that drive their purchase of roasted chicken products. This study's results also disclosed that the most prioritized factors were brown colour, health concern, friends and family lifestyle. The results of this study further identify physiological and personality attributes as internal factors, and reference groups and culture as external factors. Hence, this study concluded that internal factors (physiological, personality) and external factors (reference groups, culture) as essential factors in influencing youths' purchase of roasted chicken products. Thus, this study's outcome is beneficial for the vendors to boost their sales as well as promoting better ways of selecting foods to reduce the risk of non-communicable diseases amongst the youth in Malaysia.
  15. Occurrence of thermophilic Campylobacter spp. contamination on vegetable farms in Malaysia
    Chai LC, Ghazali FM, Bakar FA, Lee HY, Suhaimi LR, Talib SA, et al.
    J Microbiol Biotechnol, 2009 Nov;19(11):1415-20.
    PMID: 19996696
    The aim of the present study was to examine the prevalence of thermophilic Campylobacter spp. (Campylobacter jejuni and Campylobacter coli) in soil, poultry manure, irrigation water, and freshly harvested vegetables from vegetable farms in Malaysia. C. jejuni was detected in 30.4% and 2.7% of the soil samples, 57.1% and 0% of the manure samples, and 18.8% and 3% of the vegetable samples from farm A and farm B, respectively, when using the MPNPCR method. Campylobacter spp. was not found in any of the irrigation water samples tested. Therefore, the present results indicate that the aged manure used by farm A was more contaminated than the composted manure used by farm B. Mostly, the leafy and root vegetables were contaminated. C. coli was not detected in any of the samples tested in the current study. Both farms tested in this study were found to be contaminated by campylobacters, thereby posing a potential risk for raw vegetable consumption in Malaysia. The present results also provide baseline data on Campylobacter contamination at the farm level.
  16. Crustal fluid and ash alteration impacts on the biosphere of Shikoku Basin sediments, Nankai Trough, Japan
    Torres ME, Cox T, Hong WL, McManus J, Sample JC, Destrigneville C, et al.
    Geobiology, 2015 Nov;13(6):562-80.
    PMID: 26081483 DOI: 10.1111/gbi.12146
    We present data from sediment cores collected from IODP Site C0012 in the Shikoku Basin. Our site lies at the Nankai Trough, just prior to subduction of the 19 Ma Philippine Sea plate. Our data indicate that the sedimentary package is undergoing multiple routes of electron transport and that these differing pathways for oxidant supply generate a complex array of metabolic routes and microbial communities involved in carbon cycling. Numerical simulations matched to pore water data document that Ca(2+) and Cl(1-) are largely supplied via diffusion from a high-salinity (44.5 psu) basement fluid, which supports the presence of halophile Archean communities within the deep sedimentary package that are not observed in shallow sediments. Sulfate supply from basement supports anaerobic oxidation of methane (AOM) at a rate of ~0.2 pmol cm(-3) day(-1) at ~400 mbsf. We also note the disappearance of δ-Proteobacteria at 434 mbsf, coincident with the maximum in methane concentration, and their reappearance at 463 mbsf, coinciding with the observed deeper increase in sulfate concentration toward the basement. We did not, however, find ANME representatives in any of the samples analyzed (from 340 to 463 mbsf). The lack of ANME may be due to an overshadowing effect from the more dominant archaeal phylotypes or may indicate involvement of unknown groups of archaea in AOM (i.e., unclassified Euryarchaeota). In addition to the supply of sulfate from a basement aquifer, the deep biosphere at this site is also influenced by an elevated supply of reactive iron (up to 143 μmol g(-1)) and manganese (up to 20 μmol g(-1)). The effect of these metal oxides on the sulfur cycle is inferred from an accompanying sulfur isotope fractionation much smaller than expected from traditional sulfate-reducing pathways. The detection of the manganese- and iron-reducer γ-Proteobacteria Alteromonas at 367 mbsf is consistent with these geochemical inferences.
  17. Phenotypic and mutational spectrum of 21 Chinese patients with Alström syndrome
    Rethanavelu K, Fung JLF, Chau JFT, Pei SLC, Chung CCY, Mak CCY, et al.
    Am J Med Genet A, 2020 02;182(2):279-288.
    PMID: 31755649 DOI: 10.1002/ajmg.a.61412
    Alström syndrome (AS) is a monogenic syndromic ciliopathy caused by mutations in the ALMS1 (Alström Syndrome 1) gene. A total of 21 subjects with AS from 20 unrelated Chinese families were recruited. Our cohort consists of 9 females and 12 males, between 5 months and 20 years old. The first symptom(s) appeared between 3 and 24 months. They were recorded to be either visual impairments (83%) or dilated cardiomyopathy (17%). Median time from symptom onset to seeking medical attention was 6 months (3-36 months) and the median time needed to reach the final molecular diagnosis is 54 months (6-240 months). System involvement at the time of the survey was as follows: visual symptoms (100%), hearing Impairment (67%), endocrine symptoms (43%), neurological symptoms (19%), hepatic symptoms (14%), and renal Involvement (14%). These findings are comparable to data reported in the literature. However, the proportion of subjects with cognitive impairment (33%) and behavioral problems (19%) were higher. Thirty-three unique mutations were identified in the ALMS1 gene, of which 18 are novel mutations classified as pathogenic/likely pathogenic according to the American College of Medical Genetics (ACMG) guideline. Four recurrent mutations were identified in the cohort, in particular; c.2084C>A, p. (Ser695Ter), is suggestive to be a founder mutation in people of Chinese ancestry. The participation of AS subjects of differing ethnicities is essential to improve the algorithm in facial recognition/phenotyping, as well as to understand the mutation spectrum beyond than just those of European ancestry.
  18. Detection of immunoglobulin antibodies in the sera of patients using purified latex allergens
    Kurup VP, Yeang HY, Sussman GL, Bansal NK, Beezhold DH, Kelly KJ, et al.
    Clin Exp Allergy, 2000 Mar;30(3):359-69.
    PMID: 10691894
    BACKGROUND: Latex allergy is largely an occupational allergy due to sensitization to natural rubber latex allergens present in a number of health care and household products. Although several purified allergens are currently available for study, information on the usefulness of these purified, native or recombinant allergens in the demonstration of specific immunoglobulin (Ig) E in the sera of patients is lacking.

    OBJECTIVE: To evaluate the purified latex allergens and to demonstrate specific IgE antibody in the sera of health care workers and spina bifida patients with clinical latex allergy.

    METHODS: Two radioallergosorbent and an enzyme-linked immunosorbent assay (ELISA) using latex proteins Hev b 1, 2, 3, 4, 6 and 7 along with two glove extracts and Malaysian nonammoniated latex (MNA) were evaluated to demonstrate IgE in the sera of health care workers and spina bifida with latex allergy and controls with no history of latex allergy.

    RESULTS: ELISA using the purified latex allergens demonstrated specific IgE in 32-65% health care workers and 54-100% of spina bifida patients with latex allergy. The corresponding figures for RAST were 13-48 and 23-85 for RAST-1 and 19-61 and 36-57 for RAST-2. These results were comparable with the results obtained with glove extracts and crude rubber latex proteins.

    CONCLUSIONS: When used simultaneously, latex proteins Hev b 2 and Hev b 7 reacted significantly with specific serum IgE in 80% of health care workers and 92% of spina bifida patients with latex allergy by ELISA technique, while this combination gave lower positivity when the RASTs were used. By the addition of Hev b 3, specific IgE was detected in all spina bifida patients with latex allergy. Both RASTs failed to show specific IgE in the control subjects, while the ELISA showed significant latex-specific IgE in 22% of controls.

  19. Allergen concentration in natural rubber latex
    Yeang HY, Hamilton RG, Bernstein DI, Arif SA, Chow KS, Loke YH, et al.
    Clin Exp Allergy, 2006 Aug;36(8):1078-86.
    PMID: 16911364 DOI: 10.1111/j.1365-2222.2006.02531.x
    BACKGROUND:
    Hevea brasiliensis latex serum is commonly used as the in vivo and in vitro reference antigen for latex allergy diagnosis as it contains the full complement of latex allergens.

    OBJECTIVE:
    This study quantifies the concentrations of the significant allergens in latex serum and examines its suitability as an antigen source in latex allergy diagnosis and immunotherapy.

    METHODS:
    The serum phase was extracted from centrifuged latex that was repeatedly freeze-thawed or glycerinated. Quantitation of latex allergens was performed by two-site immunoenzymetric assays. The abundance of RNA transcripts of the latex allergens was estimated from the number of their clones in an Expressed Sequence Tags library.

    RESULTS:
    The latex allergens, Hev b 1, 2, 3, 4, 5, 6, 7 and 13, were detected in freeze-thawed and glycerinated latex serum at levels ranging from 75 (Hev b 6) to 0.06 nmol/mg total proteins (Hev b 4). Hev b 6 content in the latex was up to a thousand times higher than the other seven latex allergens, depending on source and/or preparation procedure. Allergen concentration was reflected in the abundance of mRNA transcripts. When used as the antigen, latex serum may bias the outcome of latex allergy diagnostic tests towards sensitization to Hev b 6. Tests that make use of latex serum may fail to detect latex-specific IgE reactivity in subjects who are sensitized only to allergens that are present at low concentrations.

    CONCLUSION:
    Latex allergy diagnostics and immunotherapy that use whole latex serum as the antigen source may not be optimal because of the marked imbalance of its constituent allergens.
  20. Fulltext Comparison of two different optical coherence tomography angiography devices in detecting healthy versus glaucomatous eyes - an observational cross-sectional study
    Kee AR, Yip VCH, Tay ELT, Lim CW, Cheng J, Teo HY, et al.
    BMC Ophthalmol, 2020 Nov 10;20(1):440.
    PMID: 33167902 DOI: 10.1186/s12886-020-01701-9
    BACKGROUND: To understand the differences between two different optical coherence tomography angiography (OCTA) devices in detecting glaucomatous from healthy eyes by comparing their vascular parameters, diagnostic accuracy and test-retest reliability.

    METHODS: A cross-sectional observational study was performed on healthy and glaucoma subjects, on whom two sets of OCTA images of optic disc and macula were acquired using both AngioVue (Optovue, USA) and Swept Source (Topcon, Japan) OCTA devices during one visit. A novel in-house software was used to calculate the vessel densities. Diagnostic accuracy of the machines in differentiating healthy versus glaucomatous eyes was determined using area under the receiver operating characteristic curve (AUROC) and test-retest repeatability of the machines was also evaluated.

    RESULTS: A total of 80 healthy and 38 glaucomatous eyes were evaluated. Glaucomatous eyes had reduced mean vessel density compared to healthy controls in all segmented layers of the optic disc and macula using AngioVue (p ≤ 0.001). However, glaucomatous eyes had higher mean vessel density on optic disc scans using Swept Source, with lack of statistically significant difference between healthy and glaucomatous eyes. The AUROC showed better diagnostic accuracy of AngioVue (0.761-1.000) compared to Swept Source (0.113-0.644). The test-retest reliability indices were generally better using AngioVue than Swept Source.

    CONCLUSIONS: AngioVue showed better diagnostic capability and test-retest reliability compared to Swept Source. Further studies need to be undertaken to evaluate if there is any significant difference between the various machines in diagnosing and monitoring glaucoma.

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