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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

Molecular studies on Toxoplasma gondii

Bhalla, Mayank January 2000 (has links)
No description available.
2

Molecular systematics of some medically important actinomycetes

Shojaei, Hasan January 1997 (has links)
No description available.
3

Estudo clinico-radiologico das infeccoes causadas por nocardia e seu diagnostico

Chedid, Maria Bernadete Fernandes January 1995 (has links)
A observação das infecções por Nocardia species em pacientes de vários hospitais de Porto Alegre, RS, de 1977 a 1991 revelou 14 casos de nocardiose pulmonar; 1 caso de nocardiose cerebral; 1 caso de nocardiose cutânea e 1 caso de micetoma. Dos 17 casos, somente 2 pacientes ( 11 ,8%) não apresentavam nenhuma doença prévia à infecção por Nocardia spp . Os demais 15 pacientes (88,2%) apresentavam doenças ou fatores associados a essas doenças causadores de diminuição da imunidade celular, representando casos em que a nocardiose foi considerada uma infecção oportunística. As doenças predisponentes mais freqüentes foram neoplasias, que incidiram em 6 pacientes (35%): doença de Hodgkin (1 paciente),linfoma e câncer do laringe(1 paciente), câncer de mama (2 pacientes), carcinoma brônquico (1 paciente) e neoplasia cerebral metastática indiferenciada (1 paciente). Cinco pacientes faziam uso de corticoesteroides em altas doses e 4 pacientes haviam usado radioterapia. Quimioterapia antiblástica estava sendo usada em 3 desses casos, também associada. DBPOC incidiu em 6 pacientes (35%), porém somente em 1 caso foi a única doença subjacente. Em outros 2 casos foi associada a hepatite e, nos demais 3 casos foi associada a doenças imunodepressoras severas e ao uso de corticóide em altas doses. Dois pacientes (11 ,7%) eram portadores de transplante renal, em uso de altas doses de corticóides e quimioterapia antiblástica. Polimiosite ocorreu associada a neoplasia em 1 caso e em outro foi a doença principal, que exigiu o uso de corticóides para seu tratamento. Tivemos 1 caso de esclerose múltipla em corticoterapia, 1 caso de LES em corticoterapia e quimioterapia antiblástica e 1 caso de SIDA. Diabete muito provavelmente ocorreu como conseqüência de corticoterapia em 3 pacientes. Corticoterapia foi a condição associada imunodepressora mais prevalente, pois foi usada em 11 pacientes (64,7%) e quimioterapia antiblástica em 6 casos (35,0%). A apresentação radiológica mais frequente da nocardiose pulmonar foi infiltração pulmonar ou consolidação (71 ,4%), seguida de cavitação (57,0%) e nódulos pulmonares (21 ,4%). Comparamos a nossa série de 17 pacientes com as séries da literatura, especialmente com a série de PRESANT et a/ (que em 1973 estudaram fatores influenciando a mortalidade de 147 pacientes com nocardiose) para avaliar diferenças e semellhanças estatisticamente significativas. Foram utilizados o teste "T" de Student para comparação de médias, o teste do Quiquadrado para comparação de proporções de indivíduos e, quando a menor frequência esperada foi inferior a 5, usou-se o teste exato de Fisher. Concluímos que as infecções por Nocardia species em Porto Alegre se assemelham à experiência de outros autores da literatura, quanto à sua apresentação clínico-radiológica; quanto às doenças e fatores imunodepressores prévios do hospedeiro; quanto ao aspecto de transmissão nosocomial entre portadores de transplante renal e quanto à evolução dos casos para cura ou óbito; com as características de que a nocardiose em nossa série foi uma infecção significativamente mais oportunística (P<0,05) do que para Presant et ai (1973), o que se deve principalmente ao número significativamente maior (P<0,05) de pacientes com neoplasias e em tratamento com drogas imunossupressoras em nossa série; de que a incidência de nocardiose do SNC e conseqüentemente de nocardiose sistêmica em nossa série foram significativamente menores (P<0,05), provavelmente devido à não sistematização do uso da tomografia computadorizada cerebral em nossos casos com sintomas neurológicos. A mortalidade dos nossos 17 pacientes com nocardiose (46, 7%) foi percentualmente menor do que a mortalidade de PRESANT et ai (59,0%), embora não significativamente menor (P<0,05). Mas nossa mortalidade não foi maior, apesar de nosso grupo ser constituído significativamente (P<0,05) por pacientes mais imunocomprometidos. Isso sugere que outros fatores tenham influenciado nossos resultados, tendendo a diminuir nossa mortalidade; entre eles, provavelmente, o diagnóstico feito mais precocemente e a influência de cepas menos patogênicas ou até mesmo espécies menos invasivas de Nocardia em nossa série, por nós identificadas somente como Nocardia spp. A nossa mortalidade (46,7%) foi semelhante à mortalidade de 42,4% obtida num grupo de 643 pacientes imunodeprimidos de um total de 1000 casos de nocardiose revisados desde 1950 por BEAMAN & BEAMAN(1994), em contraste com a mortalidade de apenas 19,8% no grupo de pacientes não imunodeprimidos, em que nocardiose foi uma infecção primária, confirmando que o fator que mais influencia na evolução da doença é a condição imune do hospedeiro . Esses dados confirmam a coincidência dos achados obtidos em nossa experiência de nocardiose em Porto Alegre, RS, 1977-1991. / lnfections by Nocardia species observed in 17 patients from many hospitais in Porto Alegre (RS), from 1977 to 1991 showed 14 cases of pulmonary nocardiosis; one case of cerebral nocardiosis; one case of cutaneous nocardiosis and one case of mycetoma. From these 17 cases, only 2 patients (11 ,8%) were previously healthy. The remaining 15 patients (88,2%) had underlying previous diseases or predisposing factors, representing cases of opportunistic nocardial disease. The most frequent predisposition for nocardial infection was malignancy, that ocurred in 6 patients(35,0%) : Hodgkin's disease(1 patient), lymphoma and cancer of the larynx (1 patient), breast cancer (2 patients) , lung cancer(1 patient) and cerebral metastatic cancer (1 patient). Five patients were taking corticoesteroids in high doses and four of them had done radiotherapy . Antineoplastic therapy was associated in three patients. Six patients had COPO previously, but in only one of them it was the main disease; in the remaining cases, it was associated to hepatites(2 patients), cancer(1 patient), AIDS(1 patient), multiple esclerosis and corticosteroid therapy (1 patient). In ou r nocardiosis series there were 2 renal transplant recipients (11, 7%) taking corticosteroids in high doses and antineoplastic therapy . Diabetes steroid-induced ocurrred in 3 patients. Polimiosites ocurred in 1 cancer patient and in another patient who needed to use corticosteroids for its treatment. We had 1 patient with multiple esclerosis on corticosteroids, 1 patient with SLE on corticosteroids and antineoplastic therapy , too; and finally, 1 patient with AIDS. Corticotherapy was the most frequent predisposing factor to nocardiosis in our series, for it was used in 11 patients (64,7%) before nocardiosis. Antineoplastic therapy was done in 6 patients (35,0%). The most common Roentgen patterns were pulmonary infiltrates or consolidations (71 ,4%), pulmonary cavitation (57,0%) and pulmonary nodules(21 ,4%). Since meaningful patterns of disease can be observed only in large samples of patients, we have prefered to compare our sample of 17 patients to the 14 7 reported cases collected from the medicai literature by PRESANT et a/ (1973), who studied factors affecting the mortality. Statistical analysis were performed using Student "T"test, Chi squared test and Fisher exact test in arder to evaluate the similarities and differences statistically significants. We have concluded that infections caused by Nocardia species in Porto Alegre(RS) are very similar to that reported in the literature : as to the clinico-radiological presentation; as to underlying diseases and predisposing factors prior to nocardiosis; as to the aspects of nosocomial transmission among transplant recipients and the outcome . There was a larger group of cancer patients on steroids and on antineoplastic therapy in our series (P<0,05) in comparison to Presant's 147 patients, and in conseqüence nocardiosis is a more opportunistic infection to us. The incidence of SNC nocardiosis and systemic nocardiosis in our series was significantly smaller (P<0,05) probably because we haven't done brain CT in ali our patients who have had neurologic simptoms. Althougt the mortality rate of our sample of 17 patients with nocardiosis (46, 7%) was percentually smaller than the mortality rate of Presan et a/ (59,0%), this difference is not sifnificantly smaller (P<0,05). Despite of that, our mortality rate is not higher than his, even our series of patients being significantly more imunnocompromised than his (P<0,05). This suggests that other factors might have affected our better results, diminishing our mortality rate. Among them are probably the diagnosis made earlier in ou r series (P<0,01) and the influence of less pathogenic strains of Nocardia or even less invasive species of Nocardia which were identified by us only as Nocardia spp. Ou r mortality rate (46, 7%) was similar to the one obtained in 643 immunodepressed patients ( 42,4% ) from a total of 1000 cases with nocardíosís revíewed sínce 1950 by BEAMAN and BEAMAN (1994); contrastíng to the mortality of only 19,8% in the group of non-immunodepressed patients, where the nocardiosis was a primary infection, confirming that the fact which most influences the evolution of the disease is the immune condition of the host. These data show the similarity between our experience of 17 cases of nocardiosís occured in Porto Alegre, RS (1977-91) and that reported by the literature.
4

Serological studies on mycobacteria, nocardia, actinomyces and fungi

Bevis, Marion Leonard, January 1951 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1951. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves [31]-33).
5

Antigens derived from Nocardia asteroides for skin testing

Groves, David Lynn, January 1966 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1966. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
6

Localisations cérébelleuse et osseuse à Nocardia : à propos de deux observations.

Rémy, Gérard, January 1900 (has links)
Thèse--Méd.--Reims, 1973. N°: N° 26. / Bibliogr. ff. I-VIII.
7

Estudo clinico-radiologico das infeccoes causadas por nocardia e seu diagnostico

Chedid, Maria Bernadete Fernandes January 1995 (has links)
A observação das infecções por Nocardia species em pacientes de vários hospitais de Porto Alegre, RS, de 1977 a 1991 revelou 14 casos de nocardiose pulmonar; 1 caso de nocardiose cerebral; 1 caso de nocardiose cutânea e 1 caso de micetoma. Dos 17 casos, somente 2 pacientes ( 11 ,8%) não apresentavam nenhuma doença prévia à infecção por Nocardia spp . Os demais 15 pacientes (88,2%) apresentavam doenças ou fatores associados a essas doenças causadores de diminuição da imunidade celular, representando casos em que a nocardiose foi considerada uma infecção oportunística. As doenças predisponentes mais freqüentes foram neoplasias, que incidiram em 6 pacientes (35%): doença de Hodgkin (1 paciente),linfoma e câncer do laringe(1 paciente), câncer de mama (2 pacientes), carcinoma brônquico (1 paciente) e neoplasia cerebral metastática indiferenciada (1 paciente). Cinco pacientes faziam uso de corticoesteroides em altas doses e 4 pacientes haviam usado radioterapia. Quimioterapia antiblástica estava sendo usada em 3 desses casos, também associada. DBPOC incidiu em 6 pacientes (35%), porém somente em 1 caso foi a única doença subjacente. Em outros 2 casos foi associada a hepatite e, nos demais 3 casos foi associada a doenças imunodepressoras severas e ao uso de corticóide em altas doses. Dois pacientes (11 ,7%) eram portadores de transplante renal, em uso de altas doses de corticóides e quimioterapia antiblástica. Polimiosite ocorreu associada a neoplasia em 1 caso e em outro foi a doença principal, que exigiu o uso de corticóides para seu tratamento. Tivemos 1 caso de esclerose múltipla em corticoterapia, 1 caso de LES em corticoterapia e quimioterapia antiblástica e 1 caso de SIDA. Diabete muito provavelmente ocorreu como conseqüência de corticoterapia em 3 pacientes. Corticoterapia foi a condição associada imunodepressora mais prevalente, pois foi usada em 11 pacientes (64,7%) e quimioterapia antiblástica em 6 casos (35,0%). A apresentação radiológica mais frequente da nocardiose pulmonar foi infiltração pulmonar ou consolidação (71 ,4%), seguida de cavitação (57,0%) e nódulos pulmonares (21 ,4%). Comparamos a nossa série de 17 pacientes com as séries da literatura, especialmente com a série de PRESANT et a/ (que em 1973 estudaram fatores influenciando a mortalidade de 147 pacientes com nocardiose) para avaliar diferenças e semellhanças estatisticamente significativas. Foram utilizados o teste "T" de Student para comparação de médias, o teste do Quiquadrado para comparação de proporções de indivíduos e, quando a menor frequência esperada foi inferior a 5, usou-se o teste exato de Fisher. Concluímos que as infecções por Nocardia species em Porto Alegre se assemelham à experiência de outros autores da literatura, quanto à sua apresentação clínico-radiológica; quanto às doenças e fatores imunodepressores prévios do hospedeiro; quanto ao aspecto de transmissão nosocomial entre portadores de transplante renal e quanto à evolução dos casos para cura ou óbito; com as características de que a nocardiose em nossa série foi uma infecção significativamente mais oportunística (P<0,05) do que para Presant et ai (1973), o que se deve principalmente ao número significativamente maior (P<0,05) de pacientes com neoplasias e em tratamento com drogas imunossupressoras em nossa série; de que a incidência de nocardiose do SNC e conseqüentemente de nocardiose sistêmica em nossa série foram significativamente menores (P<0,05), provavelmente devido à não sistematização do uso da tomografia computadorizada cerebral em nossos casos com sintomas neurológicos. A mortalidade dos nossos 17 pacientes com nocardiose (46, 7%) foi percentualmente menor do que a mortalidade de PRESANT et ai (59,0%), embora não significativamente menor (P<0,05). Mas nossa mortalidade não foi maior, apesar de nosso grupo ser constituído significativamente (P<0,05) por pacientes mais imunocomprometidos. Isso sugere que outros fatores tenham influenciado nossos resultados, tendendo a diminuir nossa mortalidade; entre eles, provavelmente, o diagnóstico feito mais precocemente e a influência de cepas menos patogênicas ou até mesmo espécies menos invasivas de Nocardia em nossa série, por nós identificadas somente como Nocardia spp. A nossa mortalidade (46,7%) foi semelhante à mortalidade de 42,4% obtida num grupo de 643 pacientes imunodeprimidos de um total de 1000 casos de nocardiose revisados desde 1950 por BEAMAN & BEAMAN(1994), em contraste com a mortalidade de apenas 19,8% no grupo de pacientes não imunodeprimidos, em que nocardiose foi uma infecção primária, confirmando que o fator que mais influencia na evolução da doença é a condição imune do hospedeiro . Esses dados confirmam a coincidência dos achados obtidos em nossa experiência de nocardiose em Porto Alegre, RS, 1977-1991. / lnfections by Nocardia species observed in 17 patients from many hospitais in Porto Alegre (RS), from 1977 to 1991 showed 14 cases of pulmonary nocardiosis; one case of cerebral nocardiosis; one case of cutaneous nocardiosis and one case of mycetoma. From these 17 cases, only 2 patients (11 ,8%) were previously healthy. The remaining 15 patients (88,2%) had underlying previous diseases or predisposing factors, representing cases of opportunistic nocardial disease. The most frequent predisposition for nocardial infection was malignancy, that ocurred in 6 patients(35,0%) : Hodgkin's disease(1 patient), lymphoma and cancer of the larynx (1 patient), breast cancer (2 patients) , lung cancer(1 patient) and cerebral metastatic cancer (1 patient). Five patients were taking corticoesteroids in high doses and four of them had done radiotherapy . Antineoplastic therapy was associated in three patients. Six patients had COPO previously, but in only one of them it was the main disease; in the remaining cases, it was associated to hepatites(2 patients), cancer(1 patient), AIDS(1 patient), multiple esclerosis and corticosteroid therapy (1 patient). In ou r nocardiosis series there were 2 renal transplant recipients (11, 7%) taking corticosteroids in high doses and antineoplastic therapy . Diabetes steroid-induced ocurrred in 3 patients. Polimiosites ocurred in 1 cancer patient and in another patient who needed to use corticosteroids for its treatment. We had 1 patient with multiple esclerosis on corticosteroids, 1 patient with SLE on corticosteroids and antineoplastic therapy , too; and finally, 1 patient with AIDS. Corticotherapy was the most frequent predisposing factor to nocardiosis in our series, for it was used in 11 patients (64,7%) before nocardiosis. Antineoplastic therapy was done in 6 patients (35,0%). The most common Roentgen patterns were pulmonary infiltrates or consolidations (71 ,4%), pulmonary cavitation (57,0%) and pulmonary nodules(21 ,4%). Since meaningful patterns of disease can be observed only in large samples of patients, we have prefered to compare our sample of 17 patients to the 14 7 reported cases collected from the medicai literature by PRESANT et a/ (1973), who studied factors affecting the mortality. Statistical analysis were performed using Student "T"test, Chi squared test and Fisher exact test in arder to evaluate the similarities and differences statistically significants. We have concluded that infections caused by Nocardia species in Porto Alegre(RS) are very similar to that reported in the literature : as to the clinico-radiological presentation; as to underlying diseases and predisposing factors prior to nocardiosis; as to the aspects of nosocomial transmission among transplant recipients and the outcome . There was a larger group of cancer patients on steroids and on antineoplastic therapy in our series (P<0,05) in comparison to Presant's 147 patients, and in conseqüence nocardiosis is a more opportunistic infection to us. The incidence of SNC nocardiosis and systemic nocardiosis in our series was significantly smaller (P<0,05) probably because we haven't done brain CT in ali our patients who have had neurologic simptoms. Althougt the mortality rate of our sample of 17 patients with nocardiosis (46, 7%) was percentually smaller than the mortality rate of Presan et a/ (59,0%), this difference is not sifnificantly smaller (P<0,05). Despite of that, our mortality rate is not higher than his, even our series of patients being significantly more imunnocompromised than his (P<0,05). This suggests that other factors might have affected our better results, diminishing our mortality rate. Among them are probably the diagnosis made earlier in ou r series (P<0,01) and the influence of less pathogenic strains of Nocardia or even less invasive species of Nocardia which were identified by us only as Nocardia spp. Ou r mortality rate (46, 7%) was similar to the one obtained in 643 immunodepressed patients ( 42,4% ) from a total of 1000 cases with nocardíosís revíewed sínce 1950 by BEAMAN and BEAMAN (1994); contrastíng to the mortality of only 19,8% in the group of non-immunodepressed patients, where the nocardiosis was a primary infection, confirming that the fact which most influences the evolution of the disease is the immune condition of the host. These data show the similarity between our experience of 17 cases of nocardiosís occured in Porto Alegre, RS (1977-91) and that reported by the literature.
8

Estudo clinico-radiologico das infeccoes causadas por nocardia e seu diagnostico

Chedid, Maria Bernadete Fernandes January 1995 (has links)
A observação das infecções por Nocardia species em pacientes de vários hospitais de Porto Alegre, RS, de 1977 a 1991 revelou 14 casos de nocardiose pulmonar; 1 caso de nocardiose cerebral; 1 caso de nocardiose cutânea e 1 caso de micetoma. Dos 17 casos, somente 2 pacientes ( 11 ,8%) não apresentavam nenhuma doença prévia à infecção por Nocardia spp . Os demais 15 pacientes (88,2%) apresentavam doenças ou fatores associados a essas doenças causadores de diminuição da imunidade celular, representando casos em que a nocardiose foi considerada uma infecção oportunística. As doenças predisponentes mais freqüentes foram neoplasias, que incidiram em 6 pacientes (35%): doença de Hodgkin (1 paciente),linfoma e câncer do laringe(1 paciente), câncer de mama (2 pacientes), carcinoma brônquico (1 paciente) e neoplasia cerebral metastática indiferenciada (1 paciente). Cinco pacientes faziam uso de corticoesteroides em altas doses e 4 pacientes haviam usado radioterapia. Quimioterapia antiblástica estava sendo usada em 3 desses casos, também associada. DBPOC incidiu em 6 pacientes (35%), porém somente em 1 caso foi a única doença subjacente. Em outros 2 casos foi associada a hepatite e, nos demais 3 casos foi associada a doenças imunodepressoras severas e ao uso de corticóide em altas doses. Dois pacientes (11 ,7%) eram portadores de transplante renal, em uso de altas doses de corticóides e quimioterapia antiblástica. Polimiosite ocorreu associada a neoplasia em 1 caso e em outro foi a doença principal, que exigiu o uso de corticóides para seu tratamento. Tivemos 1 caso de esclerose múltipla em corticoterapia, 1 caso de LES em corticoterapia e quimioterapia antiblástica e 1 caso de SIDA. Diabete muito provavelmente ocorreu como conseqüência de corticoterapia em 3 pacientes. Corticoterapia foi a condição associada imunodepressora mais prevalente, pois foi usada em 11 pacientes (64,7%) e quimioterapia antiblástica em 6 casos (35,0%). A apresentação radiológica mais frequente da nocardiose pulmonar foi infiltração pulmonar ou consolidação (71 ,4%), seguida de cavitação (57,0%) e nódulos pulmonares (21 ,4%). Comparamos a nossa série de 17 pacientes com as séries da literatura, especialmente com a série de PRESANT et a/ (que em 1973 estudaram fatores influenciando a mortalidade de 147 pacientes com nocardiose) para avaliar diferenças e semellhanças estatisticamente significativas. Foram utilizados o teste "T" de Student para comparação de médias, o teste do Quiquadrado para comparação de proporções de indivíduos e, quando a menor frequência esperada foi inferior a 5, usou-se o teste exato de Fisher. Concluímos que as infecções por Nocardia species em Porto Alegre se assemelham à experiência de outros autores da literatura, quanto à sua apresentação clínico-radiológica; quanto às doenças e fatores imunodepressores prévios do hospedeiro; quanto ao aspecto de transmissão nosocomial entre portadores de transplante renal e quanto à evolução dos casos para cura ou óbito; com as características de que a nocardiose em nossa série foi uma infecção significativamente mais oportunística (P<0,05) do que para Presant et ai (1973), o que se deve principalmente ao número significativamente maior (P<0,05) de pacientes com neoplasias e em tratamento com drogas imunossupressoras em nossa série; de que a incidência de nocardiose do SNC e conseqüentemente de nocardiose sistêmica em nossa série foram significativamente menores (P<0,05), provavelmente devido à não sistematização do uso da tomografia computadorizada cerebral em nossos casos com sintomas neurológicos. A mortalidade dos nossos 17 pacientes com nocardiose (46, 7%) foi percentualmente menor do que a mortalidade de PRESANT et ai (59,0%), embora não significativamente menor (P<0,05). Mas nossa mortalidade não foi maior, apesar de nosso grupo ser constituído significativamente (P<0,05) por pacientes mais imunocomprometidos. Isso sugere que outros fatores tenham influenciado nossos resultados, tendendo a diminuir nossa mortalidade; entre eles, provavelmente, o diagnóstico feito mais precocemente e a influência de cepas menos patogênicas ou até mesmo espécies menos invasivas de Nocardia em nossa série, por nós identificadas somente como Nocardia spp. A nossa mortalidade (46,7%) foi semelhante à mortalidade de 42,4% obtida num grupo de 643 pacientes imunodeprimidos de um total de 1000 casos de nocardiose revisados desde 1950 por BEAMAN & BEAMAN(1994), em contraste com a mortalidade de apenas 19,8% no grupo de pacientes não imunodeprimidos, em que nocardiose foi uma infecção primária, confirmando que o fator que mais influencia na evolução da doença é a condição imune do hospedeiro . Esses dados confirmam a coincidência dos achados obtidos em nossa experiência de nocardiose em Porto Alegre, RS, 1977-1991. / lnfections by Nocardia species observed in 17 patients from many hospitais in Porto Alegre (RS), from 1977 to 1991 showed 14 cases of pulmonary nocardiosis; one case of cerebral nocardiosis; one case of cutaneous nocardiosis and one case of mycetoma. From these 17 cases, only 2 patients (11 ,8%) were previously healthy. The remaining 15 patients (88,2%) had underlying previous diseases or predisposing factors, representing cases of opportunistic nocardial disease. The most frequent predisposition for nocardial infection was malignancy, that ocurred in 6 patients(35,0%) : Hodgkin's disease(1 patient), lymphoma and cancer of the larynx (1 patient), breast cancer (2 patients) , lung cancer(1 patient) and cerebral metastatic cancer (1 patient). Five patients were taking corticoesteroids in high doses and four of them had done radiotherapy . Antineoplastic therapy was associated in three patients. Six patients had COPO previously, but in only one of them it was the main disease; in the remaining cases, it was associated to hepatites(2 patients), cancer(1 patient), AIDS(1 patient), multiple esclerosis and corticosteroid therapy (1 patient). In ou r nocardiosis series there were 2 renal transplant recipients (11, 7%) taking corticosteroids in high doses and antineoplastic therapy . Diabetes steroid-induced ocurrred in 3 patients. Polimiosites ocurred in 1 cancer patient and in another patient who needed to use corticosteroids for its treatment. We had 1 patient with multiple esclerosis on corticosteroids, 1 patient with SLE on corticosteroids and antineoplastic therapy , too; and finally, 1 patient with AIDS. Corticotherapy was the most frequent predisposing factor to nocardiosis in our series, for it was used in 11 patients (64,7%) before nocardiosis. Antineoplastic therapy was done in 6 patients (35,0%). The most common Roentgen patterns were pulmonary infiltrates or consolidations (71 ,4%), pulmonary cavitation (57,0%) and pulmonary nodules(21 ,4%). Since meaningful patterns of disease can be observed only in large samples of patients, we have prefered to compare our sample of 17 patients to the 14 7 reported cases collected from the medicai literature by PRESANT et a/ (1973), who studied factors affecting the mortality. Statistical analysis were performed using Student "T"test, Chi squared test and Fisher exact test in arder to evaluate the similarities and differences statistically significants. We have concluded that infections caused by Nocardia species in Porto Alegre(RS) are very similar to that reported in the literature : as to the clinico-radiological presentation; as to underlying diseases and predisposing factors prior to nocardiosis; as to the aspects of nosocomial transmission among transplant recipients and the outcome . There was a larger group of cancer patients on steroids and on antineoplastic therapy in our series (P<0,05) in comparison to Presant's 147 patients, and in conseqüence nocardiosis is a more opportunistic infection to us. The incidence of SNC nocardiosis and systemic nocardiosis in our series was significantly smaller (P<0,05) probably because we haven't done brain CT in ali our patients who have had neurologic simptoms. Althougt the mortality rate of our sample of 17 patients with nocardiosis (46, 7%) was percentually smaller than the mortality rate of Presan et a/ (59,0%), this difference is not sifnificantly smaller (P<0,05). Despite of that, our mortality rate is not higher than his, even our series of patients being significantly more imunnocompromised than his (P<0,05). This suggests that other factors might have affected our better results, diminishing our mortality rate. Among them are probably the diagnosis made earlier in ou r series (P<0,01) and the influence of less pathogenic strains of Nocardia or even less invasive species of Nocardia which were identified by us only as Nocardia spp. Ou r mortality rate (46, 7%) was similar to the one obtained in 643 immunodepressed patients ( 42,4% ) from a total of 1000 cases with nocardíosís revíewed sínce 1950 by BEAMAN and BEAMAN (1994); contrastíng to the mortality of only 19,8% in the group of non-immunodepressed patients, where the nocardiosis was a primary infection, confirming that the fact which most influences the evolution of the disease is the immune condition of the host. These data show the similarity between our experience of 17 cases of nocardiosís occured in Porto Alegre, RS (1977-91) and that reported by the literature.
9

Mutational analysis of the rifampicin glycosyl-transferase (rgt) inactivation protein from Nocardia brasiliensis and its relationship to the vancomycin resistance of this organism

Baker, Alison Saxe 16 November 2006 (has links)
Student Number : 0418251N - MSc research report - School of Molecular and Cell Biology - Faculty of Science / Rifampicin is a chemotherapeutic agent used to combat mycobacterial and nocardial infections. Four enzymatic inactivation mechanisms have been identified which are partially responsible for the increasing number of rifampicin resistant strains. These are ADP-ribosylation, phosphorylation, decomposition and glucosylation. The gene encoding the latter, rgt, has been cloned and characterized from the opportunistic pathogen Nocardia brasiliensis. However, as of yet nothing is known of these inactivation enzymes. Thus in order to study the properties of the mechanism it is necessary to observe structure-function relationships through the characterization of mutants. Furthermore, the rgt gene confers a small yet reproducible increase to the vancomycin MIC. This has indicated that there may be other enzymatic mechanisms which are involved in the inactivation of vancomycin. Vancomycin is an important antibiotic as it is used to treat gram-positive infections by multi-drug resistant strains. Hitherto, no mechanisms of enzymatic inactivation have been identified for vancomycin. Thus in order to identify regions of DNA which may play a role in the high level resistance to vancomycin as observed in N. brasiliensis it was necessary to screen a genomic library of this organism. This was performed in a gram-positive background. No clones were identified in this study that had an increased resistance to vancomycin, indicating that the DNA involved in the phenotype is greater than that of the average insert size of the library, 1.9 kb. Future work will thus involve the generation of a genomic library with larger fragments and the subsequent screening of this. Additionally, performing a mutational analysis on the rgt gene may provide further insight into the specifics of the inactivation enzymes and thus will contribute to combating infection by opportunistic and other pathogens.
10

A study of biochemical and morphological aspects of macrophage function in experimental murine Nocardia asteroides and Nocardia brasiliensis infections

Stephens, Janet January 1987 (has links)
It is submitted in this thesis that the degree of activation or inhibition of macrophage function may differ in N. asteroides and N. brasiliensis infections with respect to release of plasminogen activator and of lysozyme The pattern of secretion of plasminogen activator and lysozyme in N. asteroides infections appears to differ in N. brasiliensis infection; and there is possibly a difference in the amount of lysozyme released by 2 day N. asteroides-activated macrophages and 2 day N. brasiliensis -activated macrophages. Strains of Nocardia organism did not influence macrophage morphology or ultrastructure. The study also shows the biochemical characteristics of plasminogen activator and lysozyme release, but not macrophage morphology and ultrastructure, are modified in the first 21 days of experimental Nocardia infections. There are three apparent mechanisms by which virulent strains of N. asteroides manage to survive within macrophages: (i) an ability to inhibit phagosome-lysozome fusion: (ii) alteration in the intraphagosomal pH: and (iii) alteration in the activity of the lysozomal enzyme acid-phosphatase. This study attempted to elucidate further the mechanisms enabling Nocardia organisms to persist and grow within macrophages. Reduced lysozyme release reflects diminished functional status of the macrophages of mice inoculated with N. asteroides or N. brasiliensis at certain times during infection. Reduced intracellular lysozyme levels have been linked with defects in bactericidal function. Such a reduction in intracellular and consequently extracellular levels of lysozyme might explain the capacity of Nocardia to survive intracellularly and to proliferate in the macrophage host.

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