Allergenicity of gutta-percha and the potential sensitization from latex products : (an animal study)

Thesis (M.S.D.)--Boston University, Henry M. Goldman School of Dental Medicine, 2003 (Endodontics).Includes bibliography (leaves 116-130).Introduced in dentistry more than 100 years ago, gutta-percha is the material of choice for root canal obturation, demonstrating minimal toxicity and tissue irritation. With the erupting incidences of latex allergies, there was a concern about the potential for immunoIogical cross-reactivity between gutta-percha and natural rubber latex. Gutta-percha is a rubber-like hydrocarbon derived from the sap of Payena and Palaquium gutta trees that are of the same botanical family as the Havea Brasiliensis trees that produce natural rubber latex. Gutta-percha is an isoprene polymer of a trans-arrangement, whose chemical composition is similar to the cis-polyisoprene of latex. One aim of this study was to test for this cross-reactivity. A total of twenty-two (22) female Dunkin-Hartley guinea pigs were divided into seven (7) groups. Two groups received latex implants subcutaneously, with one group getting a latex patch and the other getting a gutta-percha patch. Two groups received gutta-percha implants subcutaneously, with one group getting a latex patch and the other getting a gutta-percha patch. The remaining three groups were control groups. Two were negative controls, one receiving latex patches and the other receiving gutta-percha patches. The last group was the positive group receiving latex protein injected subcutaneously and latex paint on the skin of the animal. The implanted materials were left for fourteen (14) days before the patches were applied. The patches were placed for three (3) days before the animals were euthanised. Blood samples were drawn on days 1 and 14 (before placing the patches), day 14 six hours after placing the patches, and on day 15 and 16. After the animals were euthanised, tissue samples were obtained where the patches were applied and where the materials were implanted. H&E stained slides were prepared. The blood samples were analyzed by Western blot assay. The clinical, histological and immunological results indicated that there was no cross-reactivity between latex and gutta-percha. No detectable allerginicity for gutta-percha was observed however inflammatory reaction in tissue around implanted latex and gutta-percha was detected. It was concluded that the commercial gutta-percha tested did not contain the extractable proteins that can cross-react with latex. However if gutta-balata is added to the manufactured gutta-percha, caution should be considered when using this product to obturate root canals in latex-allergic patients

Clinical significance of anaplasia in childhood rhabdomyosarcoma

Background: The presence of anaplastic features has been known to correlate with poor clinical outcome in various pediatric malignancies, including Wilms tumor and medulloblastoma but not in rhabdomyosarcoma. Aim: Aim was to study the frequency of anaplasia at presentation in childhood rhabdomyosarcoma and its relationship to clinical and pathological characteristics as well as to outcome. Patients and Methods: Anaplasia was retrospectively assessed in 105 consecutive pediatric rhabdomyosarcoma patients who were registered at the Children’s Cancer Hospital in Egypt (CCHE) during the period from July 2007 till the end of May 2010. Results: Anaplasia was diagnosed in 18 patients (17.1%), focal in 10 (9.5%) and diffuse in 8 (7.6%). The distribution of anaplasia was found to be more common in older patients having age ⩾ 10 years. Also it was more likely to occur in the high risk group and in tumors with unfavorable histology (alveolar subtype), and stage IV. The 3-year failure free survival rates for patients with and without anaplasia were 27.8 ± 10.6% and 53.4 ± 5.8%, respectively (p = 0.014) and the 3-year overall survival rates were 35.3 ± 11.6% and 61 ± 6%, respectively (p = 0.019). Conclusions: The frequency of anaplasia in pediatric patients with rhabdomyosarcoma in our study was 17.1%. The presence of anaplasia had statistically significant worse clinical outcome

Global economic burden of unmet surgical need for appendicitis

Background There is a substantial gap in provision of adequate surgical care in many low- and middle-income countries. This study aimed to identify the economic burden of unmet surgical need for the common condition of appendicitis. Methods Data on the incidence of appendicitis from 170 countries and two different approaches were used to estimate numbers of patients who do not receive surgery: as a fixed proportion of the total unmet surgical need per country (approach 1); and based on country income status (approach 2). Indirect costs with current levels of access and local quality, and those if quality were at the standards of high-income countries, were estimated. A human capital approach was applied, focusing on the economic burden resulting from premature death and absenteeism. Results Excess mortality was 4185 per 100 000 cases of appendicitis using approach 1 and 3448 per 100 000 using approach 2. The economic burden of continuing current levels of access and local quality was US $92 492 million using approach 1 and$73 141 million using approach 2. The economic burden of not providing surgical care to the standards of high-income countries was $95 004 million using approach 1 and$75 666 million using approach 2. The largest share of these costs resulted from premature death (97.7 per cent) and lack of access (97.0 per cent) in contrast to lack of quality. Conclusion For a comparatively non-complex emergency condition such as appendicitis, increasing access to care should be prioritized. Although improving quality of care should not be neglected, increasing provision of care at current standards could reduce societal costs substantially

Global economic burden of unmet surgical need for appendicitis

Background There is a substantial gap in provision of adequate surgical care in many low- and middle-income countries. This study aimed to identify the economic burden of unmet surgical need for the common condition of appendicitis. Methods Data on the incidence of appendicitis from 170 countries and two different approaches were used to estimate numbers of patients who do not receive surgery: as a fixed proportion of the total unmet surgical need per country (approach 1); and based on country income status (approach 2). Indirect costs with current levels of access and local quality, and those if quality were at the standards of high-income countries, were estimated. A human capital approach was applied, focusing on the economic burden resulting from premature death and absenteeism. Results Excess mortality was 4185 per 100 000 cases of appendicitis using approach 1 and 3448 per 100 000 using approach 2. The economic burden of continuing current levels of access and local quality was US $92 492 million using approach 1 and$73 141 million using approach 2. The economic burden of not providing surgical care to the standards of high-income countries was $95 004 million using approach 1 and$75 666 million using approach 2. The largest share of these costs resulted from premature death (97.7 per cent) and lack of access (97.0 per cent) in contrast to lack of quality. Conclusion For a comparatively non-complex emergency condition such as appendicitis, increasing access to care should be prioritized. Although improving quality of care should not be neglected, increasing provision of care at current standards could reduce societal costs substantially