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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Immunomodulatory roles of endotoxin and glutaraldehyde in the development of latex allergy

Howell, Michael D. January 1900 (has links)
Thesis (Ph. D.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains xvii, 194 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 163-181).
2

The evaluation of the effect of latex condoms using cell culture techniques

Motsoane, Nana Arcilia. January 2005 (has links)
Thesis (MSc. (Anatomy, Faculty of Health Sciences))--University of Pretoria, 2004. / Summary in English. Includes bibliographical references (leaves 117-126).
3

The evaluation of the effect of latex condoms using cell culture techniques

Motsoane, Nana Arcilia 30 May 2005 (has links)
Increased awareness of protection against infections such as Hepatitis Band Human Immune-deficiency Virus (HIV)/ Acquired Immune Deficiency Syndrome (AIDS) and other sexually transmitted diseases has led to an increase in the demand for latex gloves and condoms leading to an increase in latex allergy. Besides latex, condoms also contain several undisclosed chemicals including antioxidants, accelerators, emulsifiers, stabilizers, lubricants, and in some cases flavourings and colourants. Though extensive testing is done to evaluate the physical quality of condoms, little information is available regarding the biological safety of condoms. In this study a modification of the direct cell culture testing method that is specified by the American Test Method F813-83 of 1998 was used to determine the cytotoxicity of the surface material of latex condoms prepared at time intervals that represents normal physiological exposure times T2, T4 and T8. The L929 cells were exposed to medium containing increasing amounts of condom washings (0-66%) for 20 hours. After exposure cell number and viability was determined using the Crystal violet (CV) and 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-3H-tetrazolium bromide (MTI) assays respectively. Data was evaluated using a split-plot design with the appropriate Analysis of Variance (ANOVA). The effect of the condom washings on cell morphology and CV staining, MTI metabolism and Neutral red (NR) uptake at a fixed condom washing (16%) and exposure time T8 was evaluated microscopically. Cell membrane integrity was evaluated by Propidium iodide (PI) uptake and with PI staining after fixation and Hoechst 33324 (H33342) staining nuclear structure was evaluated with fluorescence microscopy. Apoptosis induced DNA fragmentation was evaluated by agarose gel electrophoresis. The effects of condom washings at 16% condom washing and exposure times T2, T4 and T8 was further evaluated in the HeLa cell line, a cell line in origin and type closer to that of the cervical lining. Cytotoxicity was evaluated using the CV, MTT and NR assays. In the L929 cell line, condom types Non-lubricated condoms (NLC), Lubricated condoms (LC) and Lubricated and flavoured condoms (LFC) behaved differently over time of exposure and the concentrations of condom washings. LFC were found to induce a decrease in cell number compared to other condom types, followed by LC and NLC revealed increases in cell number. Split-plot analysis, revealed that condom type x time (CT x Time) is significantly different due to the effect observed at T2 for LC. The MTT usually considered being more sensitive than the CV assay showed only toxicity for LFC and not for NLC and LC as with the CV assay. Exposure to LFC revealed significant decrease of 70 % decrease in cell viability at T8. Condom washings, LC, LFC and LFCC had no effect on cell morphology following CV staining. MTT metabolism and NR uptake was reduced and altered cell morphology was observed for L929 cells exposed to LFC and LFCC. Little PI uptake was observed for all cells exposed to condom washings. Condensed nuclei were observed for L929 cells exposed to LFC and LFCC while Hoechst staining revealed peripheral arrangement of DNA with Hoechst 33342 staining. Cell death in L929 cells were found to be mediated by apoptosis with L929 exposed to LFC showing the most damage. All effects of LFC is greater than that observed for LFCC indicating that other factors rather than the number of components present in each type of condom may account for toxicity. Toxicity of condom washings were compared to that found in the L929 cell line using the CV and MTT assays and an additional bioassay the NR assay was included. Condom types, LC, LFC and LFCC had a significant effect on cell viability and lysosomal membrane integrity. Differences observed between the L929 and HeLa cells were due to the increased viability observed for LC and the decrease in membrane integrity for LFC on HeLa cells. With LC and LFC no decrease in cell number and viability was observed as previously reported for the L929 cell line. Although no decreased in cell viability is observed for LFC a decrease of 75% in lysosomal membrane integrity is observed. The increase in cell viability found for HeLa exposed to LC (although statistically not significant) cannot be explained. Changes in cell viability and membrane integrity was only observed for HeLa cells, indicating that the HeLa cell line is more sensitive to the cytotoxic effects of condom washings. Furthermore the NR assay is a more sensitive assay than the MTT assay in detecting the cytotoxic effects of LFC condom washings at low concentrations. These are assays address only the effects of short-term exposure and not possible genotoxic effects that may occur following repeated and long-term exposure as reported in other latex products. / Dissertation (MSc (Anatomy))--University of Pretoria, 2006. / Anatomy / unrestricted
4

Clinical and laboratory investigation of latex allergy in healthcare workers

De Beer, Corena 12 1900 (has links)
Thesis (PhD)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: Healthcare workers (HCWs) wear latex gloves to protect themselves and their patients against the transmission of microbial, viral and bloodborne diseases. These individuals are primarily exposed to latex via cutaneous (direct contact) and mucocutaneous (inhalation of airborne allergens on glove powder) routes. Repeated exposure leads to the formation of circulating latex-specific IgE and subsequent sensitisation with varying clinical expression. The airconditioning system of the Tygerberg Hospital (TBH) complex was investigated for the presence of aerosolised cornstarch glove powder and proteins. Dust samples were collected from 14 areas with different levels of latex glove usage. Dust samples were spectrophotometrically compared to a calibration graph of pure glove powder. The detection of starch and proteins in all the dust samples confirmed the presence of glove powder and possibly airborne latex allergens in the airconditioning ducts. As expected, the high exposure areas showed the highest concentrations of both starch and proteins. It is possible that other proteins than latex were involved, but the confirmed high level of protein contamination should be a cause for concern. Correlation between starch and protein levels was highly significant (p<0.01) in all instances. A total of 500 questionnaires were circulated for completion by HCWs from TBH. The response rate was 69.8%. After considering specific inclusion criteria, a study group of 152 individuals was compiled (28 males, 124 females). All subjects had current latex exposure and suffered from at least three pre-defined symptoms. Serum was collected from all subjects and dermal fluid from 31 subjects. Total IgE and latex specific IgE analysis were done on all serum and dermal fluid samples. Latex-specific IgE was positive (>0.35 IU/ℓ) in 23 serum and six dermal fluid samples. Skin prick tests (SPTs)for latex were done on 59 subjects with negative serum latex-specific IgE and 34 had positive results. Twelve subjects with negative latex-specific IgE and latex SPTs underwent patch tests with the European Standard Series, a piece of latex glove and glove powder in petrolatum. Three subjects had positive results to one or more of these allergens. Western blot analysis for latex was done on all positive sera and dermal fluid collected from these subjects. Western blot analysis for latex proved to be more sensitive than the capRAST, because it was able to identify specific bands in samples with negative capRAST results. All subjects showed a band for Hev b 1, which has been confirmed as a powder-bound airborne allergen. Hev b 6.01 is associated with HCWs with cutaneous symptoms and this band was recognised by 81% of the subjects. These findings confirmed that airborne and cutaneous routes are the major routes of exposure in HCWs. According to their laboratory results, subjects were divided into the following subgroups and compared statistically: Group A (serum positive, n=23), Group B (SPT positive, n=34) and Group C (negative, n=25). Group D (withdrawn, n=70) could not be used for statistical comparisons, due to incomplete results. An overall latex allergy prevalence of 38% was found. Group A differed significantly from Group B and Group C for most clinical and special investigations. Group A and B were also combined to represent all subjects with positive results (Cohort AB). The Allergy Score and Class were highly significant when Cohort AB was compared to Group C. The selection of clinical symptoms was confirmed to be relevant and work-related deterioration on any of the symptoms should bear a high index of suspicion in the evaluation of latex allergy. Numerical indices and specific symptoms showed high positive predictive values and the Allergy Score produced statistical significance in the positive subgroups when compared to the negative subgroup. Paired statistical significance was confirmed between the Allergy Score and occupational exposure (number of years, hours and pairs per week). The areas with the highest occupational latex exposure in HCWs are the face and hands. Different occupations also have different levels of exposure and two subgroups of HCWs (16 laboratory technologists and 13 theatre staff) were investigated for sebum content on different facial areas and the palms and dorsal areas of both hands. Baseline measurements were done before putting on gloves. In 21 subjects follow up measurements were done following three to four hours of occupational exposure, but before washing their hands. Baseline and follow up values were compared for all the different anatomical regions. Levels on the forehead and cheeks increased over time, while the level on the nose decreased. All hand regions decreased significantly during occupational exposure, suggesting that glove powder contributes to dryness of the skin. In conclusion, the problem posed by latex allergy will not be solved overnight and will probably remain a major occupational hazard for years to come. It is currently not possible to avoid exposure to latex, but it is imperative to institute safety measures to prevent further sensitisation in predisposed individuals and manage those already affected. / AFRIKAANSE OPSOMMING: Gesondheidswerkers dra lateks handskoene om hulleself en hulle pasiënte te beskerm teen die oordrag van mikrobiale, virale en bloed-gedraagde siektes. Die lateks blootstelling vind hier hoofsaaklik plaas via kutane (direkte velkontak) en mukokutane (inaseming van lug-gedraagde allergene op hanskoen poeier) roetes. Herhaalde blootstelling veroorsaak sirkulerende lateksspesifieke IgE en sensitisasie met variërende kliniese beelde. Die lugreëlingstelsel van die Tygerberg hospitaalkompleks is ondersoek vir die teenwoordigheid van handskoenpoeier (stysel) en lateks proteïene. Stofmonsters is versamel in 14 areas wat verskillende blootstellingsvlakke verteenwoordig het. Die stofmonsters is spektrofotometries vergelyk met "n kalibrasiekurwe van suiwer hanskoenpoeier. Stysel en proteïene kon in al die stofmonsters aangetoon word en het die teenwoordigheid van handskoenpoeier en moontlike luggedraagde lateks proteïene in die lugreëlingstelsel bevestig. Soos verwag kon word, het die hoogste stysel en proteïen waardes in hoë blootstellingsareas voorgekom. Hoogs beduidende statistiese korrelasies (p<0.01) tussen die stysel en proteïenvlakke kon aangedui word in alle monsters. "n Totaal van 500 vraelyste is gesirkuleer vir voltooiing deur TBH gesondheidswerkers, waarvan 69.8% voltooide vraelyste terugontvang is. Na evaluering van insluitingskriteria, is "n studiegroep van 152 individue saamgestel (28 mans, 124 vrouens). Almal het huidige lateks blootstelling en ten minste drie het vooraf gedefinieerde simptome gerapporteer. Serum is van die hele groep versamel en dermale vog van 31 proefpersone. Totale IgE en lateks-spesifieke IgE vlakke is op alle serum en dermale vog bepaal. Positiewe resultate (>0.35 IU/ℓ) is verkry in 23 serum en ses dermaIe vog monsters. Velpriktoets vir lateks is op 59 proefpersone uitgevoer en 34 daarvan het positiewe resultate opgelewer. Twaalf proefpersone met negatiewe lateks-spesifieke IgE en velpriktoets resultate het kutane plaktoetse ondergaan met die Europese Standaard Reeks, "n stukkie lateks handskoen en handskoenpoeier in petrolatum. Drie proefpersone het positiewe resultate teen een of meer van die allergene gehad. Westerse kladanalise vir lateks is op alle positiewe serum gedoen, asook die dermale vogte van hierdie proefpersone. Westerse kladanalise vir lateks blyk baie meer sensitief te wees as die capRAST, aangesien dit spesifieke bande kon identifiseer in monsters capRAST resultate. Alle monsters het "n band getoon vir Hev b 1, "n poeier-gebinde, luggedraade allergeen. Hev b 6.01 is geassosieer met gesondheidswerkers met velsimptome en hierdie band is gevind in 81% van die monsters. Hierdie resultate bevestig dat die belangrikste blootstelling aan lateks in gesondheidswerkers deur die vel en inaseming plaasvind. Proefpersone is in die volgende drie groepe verdeel volgens laboratorium resultate en statisties vergelyk: Groep A (positiewe serum, n=23), Groep B (positiewe velpriktoetse, n=34) en Groep C (negatief, n=25). Groep D (onttrek, n=70) kon nie vir betekenisvolle statistiese vergelykings aangewend word nie, as gevolg van onvolledige resultate. 'n Finale lateks allergie prevalensie van 38% is gevind. Groep A het hoogs beduidend verskil van Groep B en C vir die meeste van die kliniese en spesiale laboratoriumondersoeke. Groep A en B is gekombineer om alle proefpersone in te sluit met positiewe resultate (Kohort AB). Die Allergie Telling en Klas van Kohort AB was hoogs beduidend in vergelyking met Groep C. Die gekose simptome is bevestig as relevant en enige werksverwante verergering van simptome moet met 'n hoë mate van agterdog bejeën word in lateks allergie. Numeriese indekse en spesifieke simptome het hoë positiewe voorspellingswaardes gelewer en die Allergie Telling was hoogs beduidend in die positiewe subgroep in vergelyking met die negatiewe subgroep. Gepaarde statistiese beduidenheid is ook gevind tussen die Allergie Telling en beroepsblootstelling (jare van blootstelling, uur en paar handskoene per week). Die meeste beroepsblootstelling aan lateks in gesondheidswerkers vind plaas op die hande en gesig. Verskillende beroepe het ook verskillende blootstellingsvlakke en two subgroepe gesondheidswerkers (16 laboratorium tegnoloë en 13 teater personeel) is ondersoek vir die sebumgehalte op veskillende areas van die gesig en hande. Basislynvlakke is gemeet voordat handskoene aangetrek is en in 21 gevalle is opvolgvlakke gemeet na drie tot vier uur beroepsblootstelling, maar voor die hande gewas is. Basislyn en opvolgvlakke is met mekaar vergelyk vir al die anatomiese areas. Die voorkop en wange het 'n toename in sebumgehalte getoon, terwyl dié van die neus afgeneem het. AI die areas op die hande toon 'n hoogs beduidende afname tydens beroepsblootstelling, wat impliseer dat hanskoenpoeier moontlik bydra tot droogheid van die vel. In samevatting, die lateks allergie probleem sal nie oornag opgelos word nie en sal waarskynlik 'n belangrike beroepsrisiko bly vir die aansienlike toekoms. Totale vermyding van lateks is tans onmoontlik en daarom is dit van uiterste belang om voorsorgmaatreëls in plek te stel om verdere sensitisasie in blootgestelde individue te verhoed en die wat reeds geaffekteer is, effektief te hanteer.
5

Sensibilização e alergia ao látex em crianças e adolescentes com mielomeningocele / Sensitization and latex allergy in children and adolescents with myelomeningocele

Sá, Adriano Bueno de [UNIFESP] 30 June 2010 (has links) (PDF)
Made available in DSpace on 2015-07-22T20:50:47Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-06-30 / Introdução: A alergia ao látex é responsável por inúmeras reações alérgicas em indivíduos sensibilizados. Objetivos: Avaliar a prevalência de sensibilização e alergia ao látex e a alimentos em crianças e adolescentes com mielomeningocele e identificar os possíveis fatores de risco a eles associados. Métodos: Participaram do estudo 55 crianças e adolescentes com diagnóstico prévio de mielomeningocele atendidos no ambulatório de Neurocirurgia do Hospital São Paulo, UNIFESP-EPM. Os pacientes foram avaliados através de questionário padrão, testes cutâneos de hipersensibilidade imediata para aeroalérgenos, látex total e alimentos e determinação de IgE sérica total e específica ao látex total e suas frações recombinates. Resultados: Encontramos taxas de 45% e 20% para sensibilização e alergia ao látex respectivamente, com 14,5% de sensibilização a alimentos, sem casos de alergia alimentar. Vinte e quatro (43,6%) eram atópicos e a média de idade do primeiro episódio de reação ao látex foi 44,5 meses, sendo reação cutânea a mais freqüente relatada (72,7%). A sensibilização alimentar ocorreu para os seguintes alimentos: batata, mamão, mandioca, jaca, manga, abacaxi, pêra, tomate, castanha portuguesa e abacate. Níveis séricos de IgE total superiores a 200 KU/l foram mais freqüentes no grupo de pacientes alérgicos e no de sensibilizados. A concordância pelo teste de kappa entre teste cutâneo para látex e IgE sérica específica para látex total foi forte e entre teste cutâneo para látex ou IgE sérica específica para látex total e as frações rHev b1, 3, 5, 6.01 e 6.02 foram moderada ou boa. As frações IgE séricas específica para látex detectada em mais de 50% dos pacientes alérgicos ao látex foram rHev b1, 3, 5, 6.01 e 6.02. Estatisticamente houve diferença entre o grupo de alérgicos e sensibilizados quando comparado ao de não sensibilizados para as seguintes variáveis: atopia, rinite atual, angioedema, número médio de cirurgias, pacientes com quatro ou mais cirurgias, uso de DVP, presença de pelo menos um teste cutâneo positivo para aeroalérgeno, presença de pelo menos um teste cutâneo para alimentos e IgE total maior que 200 KU/l. A análise multivariada revelou como significante: asma atual, angioedema, atopia e número de cirurgias submetidas. Conclusões: Nosso estudo documentou serem elevadas as prevalências de sensibilização e alergia ao látex. Apesar de freqüente a presença de anticorpos IgE específicos a alimentos, não se confirmou a presença da síndrome látex-fruta. O teste cutâneo com extrato de látex total padronizado se mostrou seguro e confiável para o diagnóstico de alergia ao látex. A análise comparativa entre os testes cutâneos de hipersensibilidade imediata e a determinação de IgE sérica específica ao látex total revelou concordância total entre eles. IgE sérica específica às frações rHev b1, 3, 5, 6.01 e 6.02 foram detectadas em mais de 50% das crianças e adolescentes com mielomeningocele alérgicos ao látex. O número de cirugias a que os pacientes foram submetidos determinou níveis mais elevados de IgE sérica específica, sobretudo de rHev b5 e 6.01. A história de asma atual, angioedema prévio, atopia e ter sido submetido a quatro ou mais cirurgias foram fatores independentes identificados para alergia ao látex. / Background: Latex allergy is responsible for numerous allergic reactions in sensitized individuals. Objectives: To evaluate the prevalence of sensitization and latex allergy and food in children and adolescents with myelomeningocele and to identify possible risk factors associated with them. Methods: The study included 55 children and adolescents previously diagnosed with myelomeningocele treated in the neurosurgery clinic of the Hospital São Paulo, UNIFESP-EPM. Patients were assessed using standard questionnaire, skin prick tests for aeroallergens, total latex, and food and determination of serum total and specific IgE to total latex and its recombinant fractions. Results: We found rates of 45% and 20% for sensitization and latex allergy, respectively, with 14.5% of sensitization to food, with no cases of food allergy. Twenty-four (43.6%) were atopic and the average age of first episode of reaction to latex was 44.5 months, with skin reaction the most frequent reported (72.7%). The food sensitization occurred for the following foods: potatoes, papaya, manioc, jackfruit, mango, pineapple, pear, tomato, avocado and chestnut. Serum total IgE greater than 200 KU/l were more frequent in patients allergic and sensitized. The agreement using the kappa test between latex skin test and specific IgE to total latex was strong and between skin test to latex or total latex specific IgE and fractions rHev b1, 3, 5, 6:01 and 6:02 were moderate or good. The fraction of specific IgE to latex detected in more than 50% of patients were rHev b1 (16/25 - 64%) followed by rHev b6.02 (14/25 - 56%). Statistically significant difference was found between the group of allergic and sensitive when compared to non-sensitized to the following variables: atopy, current rhinitis, angioedema, average number of surgeries, patients with four or more surgeries, use of valvule, presence of at least one test positive aeroallergen skin, presence of at least one skin test for food and total IgE greater than 200 KU/l. Multivariate analysis showed as significant: current asthma, angioedema, atopy and number of surgeries undergone. Conclusions: Our study documented high leves of sensitization and latex allergy. Despite the frequent presence of specific IgE antibodies to food, the presence of latex-fruit syndrome was not confirmed. The skin test with a standardized latex extract was safe and reliable for the diagnosis of latex allergy. The comparative analysis between the skin prick tests and determination of specific IgE to total latex showed total agreement between them. Specific IgE to fractions rHev b1, 3, 5, 6:01 and 6:02 were detected in more than 50% of children and adolescents with myelomeningocele allergic to latex. The number of surgeries for which patients underwent determined higher levels of specific IgE, especially rHev b5 and 6.01. The history of current asthma, prior angioedema, atopy and having undergone four or more surgeries were independent factors identified for latex allergy. / TEDE / BV UNIFESP: Teses e dissertações

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