Displaying publications 21 - 40 of 106 in total

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  1. Hamilton RG, Adkinson NF
    J Allergy Clin Immunol, 1998 Sep;102(3):482-90.
    PMID: 9768592
    BACKGROUND: No characterized diagnostic natural rubber latex skin testing material is licensed for use in the United States.

    OBJECTIVE: We have conducted a multicenter clinical skin testing study to document the safety and diagnostic sensitivity and specificity of a candidate Hevea brasiliensis nonammoniated latex (NAL) extract. These data are intended to support the licensing of this reagent for the diagnosis of latex allergy in high-risk populations.

    METHODS: Three hundred twenty-four subjects (304 adults and 20 children) were classified by their clinical history as having latex allergy (LA group, 124 adults and 10 children) or having no latex allergy (NLA group, 180 adults and 10 children). All subjects provided blood samples and then received sequential puncture skin tests (PSTs) at 1, 100, or 1000 microg/mL protein with a bifurcated needle and NAL (Greer Laboratories) from Malaysian Hevea brasiliensis (clone 600) sap. A 2-stage glove provocation test was used to clarify latex allergy status of individuals with positive history/negative PST result and negative history/positive PST result mismatches.

    RESULTS: Twenty-four subjects (15%) originally designated as having LA on the basis of their initial clinical history were reclassified to the NLA group on the basis of a negative glove provocation test result. Of the 134 subjects with LA, 54 (40%) were highly sensitive to latex, with a positive PST result at 1 microg/mL NAL. The Greer NAL reagent produced a positive PST rate (sensitivity) of 95% and 99% in subjects with LA at 100 microg/mL and 1 mg/mL, respectively. The negative PST rate (specificity) in 190 subjects with a negative history with the NAL extract at 100 microg/mL and 1 mg/mL, was 100% and 96%, respectively. Immediately after the PST, mild systemic reactions (mainly pruritus) were recorded in 16.1 % of the adults in the LA group and 4.4% of the adults in the NLA group. No reactions required treatment with epinephrine. Only mild delayed reactions were observed in 9.6% (LA group) and 2.8% (NLA group) of subjects 24 to 48 hours after PST. Mean wheal and erythema diameters measured in the 10 children in the LA group with spina bifida at 100 microg/mL and 1 mg/mL were similar to those observed in the adults in the LA group, suggesting that children are not at increased risk for systemic reactions compared with adults.

    CONCLUSIONS: A suggestive clinical history is necessary but not sufficient for a definitive diagnosis of IgE-dependent latex allergy. These data support the safety and diagnostic efficacy of the Greer NAL, skin test reagent at 100 micro/mL and 1 mg/mL for confirmatory PSTs.

    Matched MeSH terms: Latex/immunology*; Latex Hypersensitivity/diagnosis*
  2. Ahmad Nazrun Shuid, Mohd Syukri Anwar, Ahmad Asmadi Yusof
    MyJurnal
    This study was carried out to compare the rate of burn wound healing with the applications of the latex of Carica papaya Linn. (papaya) or of silver sulfadiazine cream (SSD). Partial and full thickness burn wound (2 cm x 2 cm) was induced on the dorsal part of anaesthetized rats by using heated metal plates. The rats were divided into three groups, i.e. untreated group and groups treated daily with SSD and papaya latex, respectively. A digital camera was used to take photographs of the burn wounds daily to monitor their healing. It was found that there was no significant difference in the healing time of papaya latex treated group compared to the SSD treated group. Papaya latex contained digestive enzymes which might clean burn wounds but might also cause wound bleeding in a few rats of the papaya latex group.
    Matched MeSH terms: Latex
  3. Kaida Khalid, W. Mohd. Daud W. Yusoff, Jumiah Hassan
    MyJurnal
    Dielectric properties of natural rubber Hevea brasiliensis latex were measured at frequencies 0.2 to 20 GHz, at temperatures of 2, 15, 25, 35, and 50oC and around 30-98% moisture content. Measurements were done using open-ended coaxial line sensor and automated network analyzer. As expected, results showed that dielectric constant increased with increasing moisture. From 0.2 to 2.6 GHz, the losses were governed by conductive losses but for frequencies greater than 2.6 GHz, these were mainly due to dipolar losses. The former is due to conducting phases in hevea latex, while the latter is mainly governed by the orientation of water molecules. The results were analyzed at 2.6, 10, and 18 GHz, respectively. These were then compared with the values predicted by the dielectric mixture equations recommended by Weiner, Bruggeman and Kraszewski. All the measured values were found to be within the Weiner’s boundaries and close to the upper limit of Weiner’s model. It is also close to the predicted values of Bruggeman’s model with a/b = 0.1. All the models including Kraszewski are suitable for predicting the dielectric properties of hevea latex for frequencies 2.6 to 18 GHz, moisture content 30 to 98% and temperatures 2 to 50oC.
    Matched MeSH terms: Latex
  4. Hasma H, Subramaniam A
    Lipids, 1978 Dec;13(12):905-7.
    PMID: 27520427 DOI: 10.1007/BF02533847
    Methyl esters from the triglyceride fraction of the neutral lipids of natural rubber latex were found by gas liquid chromatography to contain about 90% of a furanoid acid. Spectroscopic analysis identified the acid as 10,13-epoxy-11-methyloctadeca-10,12-dienoic acid.
    Matched MeSH terms: Latex
  5. Naji, H.R., Sahri, M.H., Bakar, E.S., Soltani, M., Hamid, H.A.
    ASM Science Journal, 2014;8(1):36-43.
    MyJurnal
    Wood density and types of shrinkage were examined in two rubberwood latex timber clones of rubber (Hevea brasiliensis) namely RRIM 2020 and RRIM 2025, planted at densities of 500, 1000, 1500, and 2000 trees/ha, within a trial plot. The mean wood density showed a low descending trend towards high planting densities in both clones. Wood density was significantly and negatively correlated with planting density. The strength of correlation was moderate. The mean longitudinal shrinkage in both clones and tangential shrinkages in clone RRIM 2020 showed no significant difference among planting densities. The tangential (in RRIM 2025), radial and volumetric shrinkages in both clones decreased from low to high planting densities and the differences were more pronounced between densities of 500 trees/ha and 2000 trees/ha. The magnitudes of correlation between these shrinkages and planting density were low. The regression models indicated that wood density could be more ascribed by planting density followed by volumetric shrinkage. This study exhibited low variations in wood density and shrinkages among clones and the respective planting densities; however, RRIM 2025 was more stable than RRIM 2020.
    Matched MeSH terms: Latex
  6. Ahmad Kamil Arshad, Juraidah Ahmad, Mohd Izzat Asyraf Mohamad Kamal
    MyJurnal
    This paper details a study conducted to evaluate the performance of cold in-place recycling (CIPR) using polymer modified asphalt emulsion (PMAE). The asphalt emulsion was modified using natural rubber latex (NRL). Four proportions of reclaimed asphalt pavement (RAP) which are 0%, 25%, 50% and 75% were mixed with natural aggregates and modified asphalt emulsion using natural rubber latex (NRL). The results showed that the optimum modified asphalt emulsion for each proportion of RAP decreased due to the increase in RAP content. Results obtained from Indirect Tensile Strength (ITS) and Uniaxial Compressive Strength (UCS) test for the mixes complied with the requirements of the Road Engineering Association of Malaysia (REAM) specifications. The unsoaked and soaked ITS values obtained were 0.2 MPa and 0.15 MPa respectively, and the minimum compressive strength of CIPR mix obtained was 0.7 MPa. Based on the evaluation of performance for the four RAP proportions, it was determined that 50% of RAP gave the best combination of the CIPR mixture.
    Matched MeSH terms: Latex
  7. Pairu Ibrahim, Wan Manshol Wan Zain, Chai, Chee Keong, Sofian Ibrahim, Mohd Noorwadi Mat Lazim, Saadiah Sulaiman
    MyJurnal
    A safety evaluation test on human for latex films made from Radiation Prevulcanized Natural Rubber Latex (RVNRL) with sulfur-containing antioxidant was studied. Sulfur test has confirmed that there was sulfur compound presence in RVNRL derived from antioxidant used in this study. Two types of safety evaluation test were being adopted which are Patch Test and Modified Draize-95 test and this test proved that there is no clinical evidence on the presence of sulfur compound in RVNRL that may induce Type IV allergy in the unsensitized general user population. Both clinical test shows that the highest score value produced by test subjects is 1 and not exceed the allowable limit.
    Matched MeSH terms: Latex
  8. Nik Hashyati Nik Hashim, Zulkefly Sulaiman, Mahmud Tengku Muda Mohamed, Mohd Yusoff Abd Samad
    MyJurnal
    Hevea brasiliensis is one of the popular industrial crops in Malaysia better known as rubber tree belongs to the family Euphorbiaceace. From more than 12 species of Hevea, only Hevea brasiliensis is economically exploited because the milky latex extracted from the tree is the primary source of natural rubber. As in other crops, various plant physiological conditions and pathogenic diseases influence rubber production. Brown bast is one of the most serious threats to natural rubber production. In general, high-yielding clones of rubber tree are often considered to be more susceptible to this physiological disorder also commonly termed Tapping Panel Dryness (TPD). It is estimated that brown bast leads to approximately 15-20% decrease in yield. There is no known cure for brown bast yet. However, many plantation practices manage brown bast in rubber by giving tapping rest and changing tapping panel. Hence, this review condenses the causal of brown bast, symptoms of diseases and also control of brown bast affected Hevea tree.
    Matched MeSH terms: Latex
  9. Gunasagaran J, Rasid RJ, Mappiare S, Devarajooh C, Ahmad TS
    Malays Orthop J, 2018 Jul;12(2):37-41.
    PMID: 30112127 MyJurnal DOI: 10.5704/MOJ.1807.007
    Introduction: Microsurgery is a subspecialised field which requires high technical skill. Laboratory training offers good opportunity for novice surgeons to learn and repetitively practise their skills prior to hands-on clinical practice. Commonly, the training programme consists of models in a stepwise increase in fidelity: from latex sheet to anaesthetised rat. We introduce microgrids model as a daily warm up procedure in a 5-day basic microsurgery course. The purpose of this study is to evaluate the correlation between microgrids colouring under magnification with microsuturing proficiency among novice surgeons. Materials and Methods: Participants were required to fill in microgrids under magnification everyday during their 5-day training as a starter test. The number of completely filled in microgrids in 20 seconds was recorded. A simulated cut on latex sheet was sutured and the time taken to apply five sutures was recorded. The sutures were evaluated with modified Global Rating Scale (GRS). Data was analysed with SPSS. Results: There was a statistically significant correlation between the number of microgrids coloured and the time taken to apply five sutures (p<0.01). An increase in number of microgrids coloured was significantly associated with the increase in quality of the suturing technique (p< 0.01). During the 5-day basic microsurgery skills training for novice surgeons, microsuturing skill improvement correlated with microgrid colouring. Conclusion: Microgrids colouring reflected microsuturing proficiency. It is an inexpensive, readily available, and simple model of 'warm up' for hand dexterity. The microgrids model can function as a starter test for initial training and a quick screening measure to assess microsurgical skill.
    Matched MeSH terms: Latex
  10. Sofian Ibrahim, Chantara Thevy Ratnam, Chai, Chee Keong, Noor Hasni M. Ali, Mohd Noorwadi Mat Lazim, Khairiah Badri
    MyJurnal
    Peroxide pre-vulcanized natural rubber latex prepared by using gamma irradiation technique is an alternative over the conventionally prepared peroxide pre-vulcanized that used activator to promote the peroxide decomposition in natural rubber latex. Through this technique the problems aroused by some activators such as tends to darken the natural rubber latex film during the drying process can also be overcome. For this preliminary study, data obtained from crosslink density and mechanical measurements were used to evaluate the effectiveness of gamma irradiation in the vulcanization process. Increasing the quantity of tert-butyl hydroperoxide (t-BHPO) from 0.1 pphr to 0.3 pphr while the irradiation dose maintain at 12 kGy has successfully delivered peroxide vulcanized natural rubber latex films with average tensile strength, modulus @ 500% and modulus @ 700% around 15.33, 1.01 and 3.42 MPa, respectively. The effective pre-vulcanization irradiation dose with respect to maximum crosslinking density (85.8 %) was observed on film prepared at 0.1 pphr t-BHPO.
    Matched MeSH terms: Latex
  11. Sofian Ibrahim, Keong, Chai Chee, Ratnam, Chantara Thevy, Khairiah Badri
    ASM Science Journal, 2018;11(2):67-75.
    MyJurnal
    Radiation pre-vulcanised natural rubber latex (RVNRL) prepared by using gamma irradiation technique has many advantages over the conventionally prepared sulphur pre-vulcanised natural rubber latex (SPVL). Despite the fact that many potential latex dipped products can be made from RVNRL, little effort was made to fully commercialise the products because of the inferior strength of RVNRL products compared to SPVL products. An attempt was made to improve the tensile strength of RVNRL by combining both radiation and peroxide vulcanisation in order to ensure that the products will not tear or fail, and has sufficient stretch. Hexanediol diacrylate (HDDA) plays the main role as sensitizer during radiation vulcanisation and tert-butyl hydroperoxide (t-BHPO) as the co-sensitizer in peroxide vulcanisation. Pre-vulcanised natural rubber latex dipped films via hybrid radiation and peroxidation vulcanisations obtained showed tensile strength of 26.7 MPa, an increment of more than 15% compared to controlled film (22.5 MPa). Besides, the crosslink percentage of the rubber films also showed around 5% increment from 90.7% to 95.6%.
    Matched MeSH terms: Latex
  12. Taweepreda W
    Sains Malaysiana, 2014;43:241-245.
    Biodegradable polymeric films, obtained from chitosan/natural rubber latex (CS/NRL) blends with different compositions, have been prepared by wetting process. The blends were characterized by dynamic mechanical thermal analysis (DMTA) and found that the CS/NRL blends are thermodynamically incompatible. This is evident from the presence of two glass transitions, corresponding to CS and NRL phases in the blend. The mechanical properties of the CS/NRL blends were improved with increasing the amount of chitosan and after surface treatment with sulphuric acid due to the sulfonate ionic interaction. The dielectric properties was determined using Precision LCR meter in the frequency range 75 kHz up to 30 MHz. After CS/NRL surface treatment with sulphuric acid at high content of chitosan showed the highest dielectric constant. The surface properties of the CS/NRL blend films before and after surface treatment were confirmed by atomic force microscopy (AFM), respectively.
    Matched MeSH terms: Latex
  13. Ahmad Fikri Abdul Karim, Hanafi Ismail, Zulkifli Mohamad Ariff
    Sains Malaysiana, 2018;47:2163-2169.
    This research was carried out to study the effects of kenaf loading and alkaline treatment on tensile properties, density,
    thermal and morphological properties of kenaf filled natural rubber latex foam (NRLF). Samples were prepared using a
    Dunlop method. From the results, increasing loading of kenaf reduced the tensile strength and elongation at break for
    both samples, treated and untreated kenaf filled NRLF. Meanwhile, modulus at 100% elongation and density increased
    with an increased in kenaf loading. Samples with treated kenaf showed higher tensile strength, modulus at 100%
    elongation and density but low in elongation at break as compared with samples with untreated kenaf. Thermal study
    by using thermogravimetric analysis (TGA) showed that thermal stability reduced with increased in kenaf loading for
    both samples. Samples with treated kenaf have higher thermal stability compared with samples of untreated kenaf. The
    filler-matrix interaction and the pores size variation of both samples was clearly seen in the micrograph images by using
    scanning electron microscope (SEM).
    Matched MeSH terms: Latex
  14. Irnidayanti Y, Soegianto A, Brabo AH, Abdilla FM, Putranto TWC, Payus CM
    Bull Environ Contam Toxicol, 2023 Sep 13;111(3):37.
    PMID: 37704797 DOI: 10.1007/s00128-023-03786-6
    This study examined the characteristics of microplastics (MPs) in the gills and gastrointestinal tract (GIT) of mackerel (Rastrelliger kanagurta) captured in Jakarta Bay, Indonesia. All 120 fish contained MPs, with fragment > fiber > film being the most prevalent types, in that order. The total abundances of fragments, fibers, and films in the gills were as follows: 4.8 ± 1.6, 1.0 ± 0.7, and 0.3 ± 0.3, respectively. The total abundances of fragments, fibers, and films in the GIT were 5.9 ± 2.3, 1.3 ± 0.8, and 0.4 ± 0.4, respectively. Statistical analysis showed that the abundance of fragments, fibers and films in both the gills and GIT of mackerel did not differ significantly between sampling locations. In the gills and GIT, MPs with sizes less than 0.1 mm and MPs that were black in color were most prevalent. Fourier transform infrared (FTIR) spectroscopy tests on MPs from the tissues of mackerel showed that there were 8 different types of MP polymers, namely, latex, nylon, polymethyl methacrylate (PMMA), cellulose acetate (CA), polyurethane (PU), polycarbonate (PC), polystyrene (PS), and polytetrafluoroethylene (PTFE). Latex and polycarbonate were detected in fish samples from Jakarta Bay.
    Matched MeSH terms: Latex
  15. Lee YK, Lay LK, Mahsufi MS, Guan TS, Elumalai S, Thong OM
    Pak J Pharm Sci, 2012 Jul;25(3):645-50.
    PMID: 22713955
    The rubber tree (Hevea brasiliensis) extracts are becoming increasingly visible in pharmaceutical and therapeutical research. The present study is aimed at examining the specific anti-proliferation property of H. brasiliensis latex B-serum sub-fractions against human breast cancer epithelial cell lines MCF-7 and MDA-MB231. The results showed that the latex whole B-serum and DBP sub-fraction exerted a specific anti-proliferation activity against cancer-origin cells MDA-MB231 but had little effect on non-cancer-origin cells. On the other hand, the anti-proliferative activity was diminished in the pre-heated B-serum fractions. With the low toxicity that the B-serum demonstrated previously in Brine Shrimp Lethality Test (BSLT), the present results suggest the potential use of the B-serum sub-fractions in cancer treatment.
    Matched MeSH terms: Latex/pharmacology*; Latex/toxicity
  16. Daruliza KM, Yang KL, Lam KL, Priscilla JT, Sunderasan E, Ong MT
    Eur Rev Med Pharmacol Sci, 2011 Oct;15(10):1163-71.
    PMID: 22165677
    Hevea brasiliensis extracts could potentially be employed as a relatively low cost resource for various anti-fungal activities due to the simplicity of the extract preparation and its abundance especially in the tropical region. Latex B-serum was reported to have anti-cancer property and its specificity in anti-fungal property has not been elucidated. The present study was conducted to determine the anti-fungal activity of Hevea latex B-serum against Candida (C.) albicans (a rounded cell fungus) and Aspergillus (A.) niger (a filamentous fungus).
    Matched MeSH terms: Latex/pharmacology*; Latex/toxicity
  17. Allmers H
    Contact Derm., 2001 Jan;44(1):30-3.
    PMID: 11156008
    72 subjects reporting symptoms indicating Type I hypersensitivity reactions to natural rubber latex (NRL) gloves were included in this study. 44 of them had a positive prick test to NRL. They underwent wearing tests using 2 types of NRL gloves with high (n=63) and low (n=70) allergen contents. Unigloves Malaysia with a high allergen content caused positive skin reactions in 47% of SPT-positive and no IgE-negative subjects. After application of Hand Sense skin protection cream, the frequency of positive skin responses in wearing tests decreased to 30% in prick-test-positive subjects. The Biogel Diagnostic gloves with low allergen caused hypersensitivity with and without Hand Sense in 2 cases (5%) of the prick-test-positive. 60% of all test participants had a positive prick test to NRL. No prick-test-negative subjects showed any urticaria during the glove-wearing test. Our study demonstrates that high allergen contents in latex gloves frequently elicit skin responses in NRL-sensitized subjects. Since other skin protection creams have shown to increase allergic symptoms, it is encouraging to report that Hand Sense skin cream may hamper the uptake of allergens from gloves, thus decreasing allergic reactions.
    Matched MeSH terms: Latex Hypersensitivity/etiology; Latex Hypersensitivity/prevention & control*
  18. Habib MAH, Gan CY, Abdul Latiff A, Ismail MN
    Biochem. Cell Biol., 2018 12;96(6):818-824.
    PMID: 30058361 DOI: 10.1139/bcb-2018-0020
    The natural rubber latex extracted from the bark of Hevea brasiliensis plays various important roles in modern society. Post-translational modifications (PTMs) of the latex proteins are important for the stability and functionality of the proteins. In this study, latex proteins were acquired from the C-serum, lutoids, and rubber particle layers of latex without using prior enrichment steps; they were fragmented using collision-induced dissociation (CID), higher-energy collisional dissociation (HCD), and electron-transfer dissociation (ETD) activation methods. PEAKS 7 were used to search for unspecified PTMs, followed by analysis through PTM prediction tools to crosscheck both results. There were 73 peptides in 47 proteins from H. brasiliensis protein sequences derived from UniProtKB were identified and predicted to be post-translationally modified. The peptides with PTMs identified include phosphorylation, lysine acetylation, N-terminal acetylation, hydroxylation, and ubiquitination. Most of the PTMs discovered have yet to be reported in UniProt, which would provide great assistance in the research of the functional properties of H. brasiliensis latex proteins, as well as being useful biomarkers. The data are available via the MassIVE repository with identifier MSV000082419.
    Matched MeSH terms: Latex/metabolism*; Latex/chemistry
  19. Wagner B, Krebitz M, Buck D, Niggemann B, Yeang HY, Han KH, et al.
    J Allergy Clin Immunol, 1999 Nov;104(5):1084-92.
    PMID: 10550757
    BACKGROUND: Two natural rubber latex proteins, Hev b 1 and Hev b 3, have been described in spina bifida (SB)-associated latex allergy.

    OBJECTIVE: The aim of this study was to clone and express Hev b 3 and to obtain the immunologic active and soluble recombinant allergen for diagnosis of SB-associated latex allergy.

    METHODS: A complementary DNA (cDNA) coding for Hev b 3 was amplified from RNA of fresh latex collected from Malaysian rubber trees (Hevea brasiliensis). PCR primers were designed according to sequences of internal peptide fragments of natural (n) Hev b 3. The 5'-end sequence was obtained by specific amplification of cDNA ends. The recombinant (r) Hev b 3 was produced in Escherichia coli as a 6xHis tagged protein. Immunoblotting and inhibition assays were performed to characterize the recombinant allergen.

    RESULTS: An Hev b 3 cDNA clone of 922 bp encoding a protein of 204 amino acid residues corresponding to a molecular weight of 22.3 kd was obtained. In immunoblots 29/35, latex-allergic patients with SB revealed IgE binding to rHev b 3, as did 4 of 15 of the latex-sensitized group. The presence of all IgE epitopes on rHev b 3 was shown by its ability to abolish all IgE binding to nHev b 3. Hev b 3 is related to Hev b 1 by a sequence identity of 47%. Cross-reactivity between these 2 latex allergens was illustrated by the large extent of inhibition of IgE binding to nHev b 1 by rHev b 3.

    CONCLUSION: rHev b 3 constitutes a suitable in vitro reagent for the diagnosis of latex allergy in patients with SB. The determination of the full sequence of Hev b 3 and the production of the recombinant allergen will allow the epitope mapping and improve diagnostic reagents for latex allergy.

    Matched MeSH terms: Latex/immunology*; Latex Hypersensitivity/blood; Latex Hypersensitivity/complications; Latex Hypersensitivity/immunology*
  20. Chaubal TV, Bapat RA, Patil PG, Shetty A
    Contact Derm., 2016 Oct;75(4):256-7.
    PMID: 27620128 DOI: 10.1111/cod.12625
    Matched MeSH terms: Latex Hypersensitivity/complications*; Latex Hypersensitivity/diagnosis
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