Diagnostic accuracy of pelvis multiparametric MRI against CT virtual hysterosalpingography: a prospective study of tubal patency through female infertility assessment.

OBJECTIVE: To evaluate the diagnostic accuracy of MRI-hysterosalpingogram (HSG) with semiquantitative dynamic contrast-enhanced perfusion, against the virtual multislice CT hysterosalpingogram (VHSG) as a reference standard. METHODS AND MATERIALS: In this prospective study, 26 women (age >18 years) searching for infertility causes and with VHSG physician request. Thereafter, the assessment performance of both techniques was determined by two reader analyses. k statistics were used for the assessment of tubal patency. Receiver operating characteristic (ROC) analysis was used to compare the capability for tubal patency assessment between both exams on a per-patient and per-tube basis. The McNemar test was used to compare the diagnostic accuracy measures. RESULTS: Tubal patency, uterine morphological, ovarian, and extrauterine abnormalities were evaluated through both exams in all 26 women. There was no significant difference between diagnostic performance measurements between the methods. The ROC curve of VHSG was 0.852 for both per-patient and per-tube analyses, and one and 0.938 for MRI-HSG. Sensitivity and specificity for per-patient and per-tube for VHSG were 95.2 and 97.7, 80 and 87.5%, and for MRI-HSG 100% for both analyses and 100 and 87.5%, respectively. CONCLUSION: This study demonstrates the feasibility of diagnosing tubal patency through MRI, using a semi-quantitative dynamic contrast-enhanced perfusion sequence, and the satisfactory diagnosing of the uterine morphology, ovarian abnormalities, and ovarian and deep endometriosis. ADVANCES IN KNOWLEDGE: Multiparametric MRI with a perfusion real-time sequence as a HSG method can be used in the evaluation not only for uterine and ovarian abnormilities but also tubal patency.

Achados tomográficos incidentais de calcificações coronarianas: um estudo de prevalência na região sul do Brasil / Incidental tomographic findings of coronary artery calcifications: a prevalence study in southern Brazil

Fundamento: As calcificações de artérias coronárias (CAC) mostram-se como fator preditivo de doenças cardiovasculares (DCV). A tomografia computadorizada (TC) de tórax com protocolo de aquisição de baixa dose apresenta acurácia na identificação de CAC e propicia achados incidentais dessas calcificações, que são comumente negligenciados. Este estudo analisará a prevalência de achados incidentais de calcificação em artérias coronárias em indivíduos não cardiopatas submetidos à TC de tórax. Métodos: Estudo transversal consecutivo de caráter analítico e descritivo. Foram incluídos indivíduos de ambos os sexos que realizaram TC de tórax por encaminhamento, acima de 18 anos e não cardiopatas. A coleta de dados foi realizada por meio de prontuários e ficha de anamnese auto aplicada. As variáveis referentes às CAC e à extensão do comprometimento foram obtidas a partir da reavaliação das imagens de TC de tórax disponíveis no sistema da instituição. Os exames foram anonimizados e avaliados por dois médicos radiologistas experientes. Considerou-se como estatisticamente significativo p≤0,05. Resultados: Foram analisados 397 exames. Encontrou-se prevalência de calcificações em 176 (44%) dos casos. A existência dessas calcificações coronárias está relacionada à idade (p<0,001). As calcificações possuem relação com o sexo (p = 0,03) com maior razão de chance de desenvolvimento em homens (odds ratio [OR] = 1,55). O tabagismo (p<0,001), o sedentarismo (p<0,001), a hipertensão arterial sistêmica (p<0,001), o diabetes mellitus (p = 0,04) e as dislipidemias (p<0,001) mostraram associação positiva. Conclusão: A prevalência de achados incidentais de CAC foi de 44%; variam em maior número entre leve e grave; maior razão de chance no sexo masculino e aumento da prevalência com a idade. Portanto, a TC de tórax mostra-se um efetivo método para avaliar as CAC, e juntamente com a história clínica do paciente pode ser utilizada para medir os fatores de risco para doenças cardiovasculares e intervir no desfecho do quadro.(AU)

Introduction: Coronary artery calcifications (CAC) are shown to be a predictive factor of cardiovascular diseases. Computed tomography (CT) of the chest with a low-dose acquisition protocol is accurate in identifying CAC and provides incidental findings of these calcifications, which are commonly overlooked. This study will analyze the prevalence of incidental findings of calcification in coronary arteries in non-cardiac individuals undergoing chest CT. Methods: Consecutive cross-sectional study of an analytical and descriptive nature. Individuals of both genders who underwent chest CT by referral, over 18 years of age and without heart disease were included. Data collection was carried out using medical records and a self-applied anamnesis form. The variables referring to the CAC and the extension of the impairment were obtained from the reassessment of the chest CT images available in the institution's system. The exams were anonymized and evaluated by two experienced radiologists. P≤0.05 was considered statistically significant. Results: 397 exams were analyzed. A prevalence of calcifications was found in 176 (44%) of the cases. The existence of these coronary calcifications is related to age (p<0.001). Calcifications are related to gender (p = 0.03) with a higher odds ratio of development in men (odds ratio [OR] = 1.55). Smoking (p<0.001), sedentary lifestyle (p<0.001), systemic arterial hypertension (p<0.001), Diabetes Mellitus (p = 0.04), and dyslipidemia (p<0.001) showed a positive association. Conclusion: The prevalence of incidental CAC findings was 44%; vary in greater numbers between mild and severe; higher odds ratio in males and increased prevalence with age. Therefore, chest CT proves to be an effective method to assess CAC, and together with the patient's clinical history, it can be used to measure risk factors for CVD and intervene in the outcome of the condition.(AU)

Computed tomography on lung cancer screening is useful for adjuvant comorbidity diagnosis in developing countries.

Purpose: The aim of this study was to analyse and quantify the prevalence of six comorbidities from lung cancer screening (LCS) on computed tomography (CT) scans of patients from developing countries. Methods: For this retrospective study, low-dose CT scans (n=775) were examined from patients who underwent LCS in a tertiary hospital between 2016 and 2020. An age- and sex-matched control group was obtained for comparison (n=370). Using the software, coronary artery calcification (CAC), the skeletal muscle area, interstitial lung abnormalities, emphysema, osteoporosis and hepatic steatosis were accessed. Clinical characteristics of each participant were identified. A t-test and Chi-squared test were used to examine differences between these values. Interclass correlation coefficients (ICCs) and interobserver agreement (assessed by calculating kappa coefficients) were calculated to assess the correlation of measures interpreted by two observers. p-values <0.05 were considered significant. Results: One or more comorbidities were identified in 86.6% of the patients and in 40% of the controls. The most prevalent comorbidity was osteoporosis, present in 44.2% of patients and in 24.8% of controls. New diagnoses of cardiovascular disease, emphysema and osteoporosis were made in 25%, 7% and 46% of cases, respectively. The kappa coefficient for CAC was 0.906 (p<0.001). ICCs for measures of liver, spleen and bone density were 0.88, 0.93 and 0.96, respectively (p<0.001). Conclusions: CT data acquired during LCS led to the identification of previously undiagnosed comorbidities. The LCS is useful to facilitate comorbidity diagnosis in developing countries, providing opportunities for its prevention and treatment.

Whole-body magnetic resonance imaging for the diagnosis of metastasis in children and adolescents: a systematic review and meta-analysis.

Whole-body magnetic resonance imaging (WB-MRI) is a noninvasive imaging method that can be used to diagnose and stage tumors, as well as to assess therapeutic responses in oncology. The objective of this meta-analysis was to evaluate the accuracy of WB-MRI for the diagnosis of metastases in pediatric patients. The following electronic databases were searched: Medline, Embase, Cochrane Central Register of Controlled Trials, Scientific Electronic Library Online, Latin-American and Caribbean Health Sciences Literature, Cumulative Index to Nursing and Allied Health Literature, Web of Science, and ClinicalTrials.gov. All of the selected studies included children and adolescents with histopathological confirmation of a primary tumor. Collectively, the studies included 118 patients ranging in age from 7 months to 19 years. The pooled sensitivity and specificity of WB-MRI were, respectively, 0.964 (95% CI: 0.944-0.978; I 2 = 0%) and 0.902 (95% CI: 0.882-0.919; I 2 = 98.4%), with an area under the curve (AUC) of 0.991. We found that WB-MRI had good accuracy for the diagnosis of metastases in pediatric patients and could therefore provide an alternative to complete the staging of tumors in such patients, being a safer option because it does not involve the use of ionizing radiation.

A ressonância magnética de corpo inteiro (WB-MRI) é um método de imagem não invasivo que pode ser usado para diagnosticar, estadiar e avaliar a resposta terapêutica em oncologia. O objetivo desta meta-análise foi avaliar a precisão do diagnóstico de WB- MRI no diagnóstico de metástases em crianças. Foram pesquisadas as seguintes bastes de dados: Medline, Embase, Cochrane Central Register of Controlled Trials, Scientific Electronic Library Online, Latin-American and Caribbean Health Sciences Literature, Cumulative Index to Nursing and Allied Health Literature, Web of Science, and ClinicalTrials.gov. Todos os estudos incluíram crianças e adolescentes com prova histopatológica de um tumor original. Os estudos selecionados incluíram 118 pacientes com idade variando de 7 meses a 19 anos. A sensibilidade e especificidade combinadas de WB-MRI foram, respectivamente, 0,964 (IC 95%: 0,944-0,978; I 2 = 0%) e 0,902 (IC 95%: 0,882-0,919; I 2 = 98,4%), com AUC de 0,991. A WB-MRI tem uma boa precisão para o diagnóstico de metástases em pediatria e pode potencialmente fornecer um método alternativo não ionizante mais seguro para completar o estadiamento da doença maligna em crianças.

Whole-body magnetic resonance imaging for the diagnosis of metastasis in children and adolescents: a systematic review and meta-analysis / A ressonância magnética de corpo inteiro no diagnóstico de metástases em crianças e adolescentes: uma revisão sistemática e meta-análise

Abstract Whole-body magnetic resonance imaging (WB-MRI) is a noninvasive imaging method that can be used to diagnose and stage tumors, as well as to assess therapeutic responses in oncology. The objective of this meta-analysis was to evaluate the accuracy of WB-MRI for the diagnosis of metastases in pediatric patients. The following electronic databases were searched: Medline, Embase, Cochrane Central Register of Controlled Trials, Scientific Electronic Library Online, Latin-American and Caribbean Health Sciences Literature, Cumulative Index to Nursing and Allied Health Literature, Web of Science, and ClinicalTrials.gov. All of the selected studies included children and adolescents with histopathological confirmation of a primary tumor. Collectively, the studies included 118 patients ranging in age from 7 months to 19 years. The pooled sensitivity and specificity of WB-MRI were, respectively, 0.964 (95% CI: 0.944-0.978; I2 = 0%) and 0.902 (95% CI: 0.882-0.919; I2 = 98.4%), with an area under the curve (AUC) of 0.991. We found that WB-MRI had good accuracy for the diagnosis of metastases in pediatric patients and could therefore provide an alternative to complete the staging of tumors in such patients, being a safer option because it does not involve the use of ionizing radiation.

Resumo A ressonância magnética de corpo inteiro (WB-MRI) é um método de imagem não invasivo que pode ser usado para diagnosticar, estadiar e avaliar a resposta terapêutica em oncologia. O objetivo desta meta-análise foi avaliar a precisão do diagnóstico de WB- MRI no diagnóstico de metástases em crianças. Foram pesquisadas as seguintes bastes de dados: Medline, Embase, Cochrane Central Register of Controlled Trials, Scientific Electronic Library Online, Latin-American and Caribbean Health Sciences Literature, Cumulative Index to Nursing and Allied Health Literature, Web of Science, and ClinicalTrials.gov. Todos os estudos incluíram crianças e adolescentes com prova histopatológica de um tumor original. Os estudos selecionados incluíram 118 pacientes com idade variando de 7 meses a 19 anos. A sensibilidade e especificidade combinadas de WB-MRI foram, respectivamente, 0,964 (IC 95%: 0,944-0,978; I2 = 0%) e 0,902 (IC 95%: 0,882-0,919; I2 = 98,4%), com AUC de 0,991. A WB-MRI tem uma boa precisão para o diagnóstico de metástases em pediatria e pode potencialmente fornecer um método alternativo não ionizante mais seguro para completar o estadiamento da doença maligna em crianças.

Diffusion-weighted magnetic resonance imaging for differentiating between benign and malignant thoracic lymph nodes: a meta-analysis.

OBJECTIVE: To establish the diagnostic performance of diffusion-weighted magnetic resonance imaging (DWI) in discriminating malignant from non-malignant thoracic lymph nodes. MATERIALS AND METHODS: This was a meta-analysis involving systematic searches of the MEDLINE, EMBASE, and Web of Science databases up through April 2020. Studies reporting thoracic DWI and lymph node evaluation were included. The pooled sensitivity, specificity, diagnostic odds ratio, positive predictive value, negative predictive value, and area under the receiver operating characteristic curve (AUC) were calculated. RESULTS: We evaluated six studies, involving a collective total of 356 mediastinal lymph nodes in 214 patients. Thoracic DWI had a pooled sensitivity and specificity of 92% (95% confidence interval [95% CI]: 71-98%) and 93% (95% CI: 79-98%), respectively. The positive and negative likelihood ratios were 13.2 (95% CI: 4.0-43.8) and 0.09 (95% CI: 0.02-0.36), respectively. The diagnostic odds ratio was 149 (95% CI: 18-1,243), and the AUC was 0.97 (95% CI: 0.95-0.98). CONCLUSION: DWI is a reproducible technique and has demonstrated high accuracy for differentiating between malignant and benign states in thoracic lymph nodes.

OBJETIVO: Uma meta-análise foi realizada para estabelecer o desempenho diagnóstico da ressonância magnética com imagem ponderada em difusão (DWI) na discriminação de linfonodos torácicos malignos de benignos. MATERIAIS E MÉTODOS: MEDLINE, EMBASE e Web of Science foram sistematicamente pesquisados até abril de 2020. Foram incluídos estudos que relatavam o uso de DWI na avaliação de linfonodos torácicos. Sensibilidade, especificidade, razão de chances de diagnóstico, valores preditivos positivos e negativos e área sob a curva (AUC) foram calculados. RESULTADOS: Foram encontrados 356 linfonodos mediastinais de 214 pacientes nos seis estudos incluídos. DWI produziu sensibilidade e especificidade combinadas de 92% (intervalo de confiança 95% [IC 95%]: 71-98%) e 93% (IC 95%: 79-98%), respectivamente. A razão de verossimilhança positiva foi de 13,2 (IC 95%: 4,0-43,8), a razão de verossimilhança negativa foi de 0,09 (IC 95%: 0,02-0,36); A razão de chances de diagnóstico foi de 149 (IC 95%: 18-1.243). A DWI teve uma AUC de 0,97 (IC 95%: 0,95-0,98). CONCLUSÃO: DWI é uma técnica reprodutível que demonstrou alta acurácia na diferenciação de estados malignos e benignos nos linfonodos torácicos.

Diffusion-weighted magnetic resonance imaging for differentiating between benign and malignant thoracic lymph nodes: a meta-analysis / Ressonância magnética ponderada em difusão para a diferenciação entre linfonodos torácicos malignos de benignos: uma meta-análise

Abstract Objective: To establish the diagnostic performance of diffusion-weighted magnetic resonance imaging (DWI) in discriminating malignant from non-malignant thoracic lymph nodes. Materials and Methods: This was a meta-analysis involving systematic searches of the MEDLINE, EMBASE, and Web of Science databases up through April 2020. Studies reporting thoracic DWI and lymph node evaluation were included. The pooled sensitivity, specificity, diagnostic odds ratio, positive predictive value, negative predictive value, and area under the receiver operating characteristic curve (AUC) were calculated. Results: We evaluated six studies, involving a collective total of 356 mediastinal lymph nodes in 214 patients. Thoracic DWI had a pooled sensitivity and specificity of 92% (95% confidence interval [95% CI]: 71-98%) and 93% (95% CI: 79-98%), respectively. The positive and negative likelihood ratios were 13.2 (95% CI: 4.0-43.8) and 0.09 (95% CI: 0.02-0.36), respectively. The diagnostic odds ratio was 149 (95% CI: 18-1,243), and the AUC was 0.97 (95% CI: 0.95-0.98). Conclusion: DWI is a reproducible technique and has demonstrated high accuracy for differentiating between malignant and benign states in thoracic lymph nodes.

Resumo Objetivo: Uma meta-análise foi realizada para estabelecer o desempenho diagnóstico da ressonância magnética com imagem ponderada em difusão (DWI) na discriminação de linfonodos torácicos malignos de benignos. Materiais e Métodos: MEDLINE, EMBASE e Web of Science foram sistematicamente pesquisados até abril de 2020. Foram incluídos estudos que relatavam o uso de DWI na avaliação de linfonodos torácicos. Sensibilidade, especificidade, razão de chances de diagnóstico, valores preditivos positivos e negativos e área sob a curva (AUC) foram calculados. Resultados: Foram encontrados 356 linfonodos mediastinais de 214 pacientes nos seis estudos incluídos. DWI produziu sensibilidade e especificidade combinadas de 92% (intervalo de confiança 95% [IC 95%]: 71-98%) e 93% (IC 95%: 79-98%), respectivamente. A razão de verossimilhança positiva foi de 13,2 (IC 95%: 4,0-43,8), a razão de verossimilhança negativa foi de 0,09 (IC 95%: 0,02-0,36); A razão de chances de diagnóstico foi de 149 (IC 95%: 18-1.243). A DWI teve uma AUC de 0,97 (IC 95%: 0,95-0,98). Conclusão: DWI é uma técnica reprodutível que demonstrou alta acurácia na diferenciação de estados malignos e benignos nos linfonodos torácicos.

Comparison between the health-related quality of life of children/adolescents with asthma and that of their caregivers: a systematic review and meta-analysis.

OBJECTIVE: To evaluate the health-related quality of life (HRQoL) of children/adolescents with asthma and that of their caregivers, comparing the two. METHODS: This was a systematic review and meta-analysis based on the criteria of Preferred Reporting Items for Systematic Reviews and Meta-Analyses, with a strategy of searching five health-related databases (MEDLINE/PubMed, EMBASE, ScienceDirect, SciELO, and LILACS). We included studies that evaluated the HRQoL of children/adolescents with asthma and that of their caregivers with the Pediatric Asthma Quality of Life Questionnaire and the Pediatric Asthma Caregiver's Quality of Life Questionnaire, respectively, using the total scores and the scores on the domains activity limitation, symptoms (children/adolescents only), and emotional function. RESULTS: We identified 291 articles, and we evaluated 133 of those. A total of 33 articles, collectively including 4,101 subjects, were included in the meta-analysis. An analysis stratified by study design showed no differences between the HRQoL of the caregivers and that of the children/adolescents in the activity limitation domain and in the total score. However, the mean emotional function domain scores were significantly higher (better) among children/adolescents with asthma than among their caregivers in longitudinal studies-Δ = 0.82 (0.21-1.44)-and randomized clinical trials-Δ = 0.52 (0.29-0.79)-although not in cross-sectional studies-Δ = -0.20 (-0.03 to 0.43). CONCLUSIONS: The total HRQoL scores proved to be similar between children/adolescents with asthma and their caregivers. However, the two groups differed in their perception of their emotional function, the caregivers scoring significantly lower than the children/adolescents in that domain.

Comparison between the health-related quality of life of children/adolescents with asthma and that of their caregivers: a systematic review and meta-analysis / Comparação da qualidade de vida relacionada à saúde de crianças/adolescentes com asma e de seus cuidadores: uma revisão sistemática e meta-análise

ABSTRACT Objective: To evaluate the health-related quality of life (HRQoL) of children/adolescents with asthma and that of their caregivers, comparing the two. Methods: This was a systematic review and meta-analysis based on the criteria of Preferred Reporting Items for Systematic Reviews and Meta-Analyses, with a strategy of searching five health-related databases (MEDLINE/PubMed, EMBASE, ScienceDirect, SciELO, and LILACS). We included studies that evaluated the HRQoL of children/adolescents with asthma and that of their caregivers with the Pediatric Asthma Quality of Life Questionnaire and the Pediatric Asthma Caregiver's Quality of Life Questionnaire, respectively, using the total scores and the scores on the domains activity limitation, symptoms (children/adolescents only), and emotional function. Results: We identified 291 articles, and we evaluated 133 of those. A total of 33 articles, collectively including 4,101 subjects, were included in the meta-analysis. An analysis stratified by study design showed no differences between the HRQoL of the caregivers and that of the children/adolescents in the activity limitation domain and in the total score. However, the mean emotional function domain scores were significantly higher (better) among children/adolescents with asthma than among their caregivers in longitudinal studies-Δ = 0.82 (0.21-1.44)-and randomized clinical trials-Δ = 0.52 (0.29-0.79)-although not in cross-sectional studies-Δ = −0.20 (−0.03 to 0.43). Conclusions: The total HRQoL scores proved to be similar between children/adolescents with asthma and their caregivers. However, the two groups differed in their perception of their emotional function, the caregivers scoring significantly lower than the children/adolescents in that domain.

RESUMO Objetivo: Avaliar e comparar os níveis de qualidade de vida relacionada à saúde (QVRS) de crianças/adolescentes com asma e de seus cuidadores. Métodos: Revisão sistemática e meta-análise baseada nos critérios de Preferred Reporting Items for Systematic Reviews and Meta-Analyses, com estratégia de busca em cinco bases de dados em saúde (MEDLINE/PubMed, EMBASE, ScienceDirect, SciELO e LILACS). Foram incluídos estudos que avaliaram a QVRS de crianças/adolescentes com asma e de seus cuidadores por meio dos escores totais e dos domínios limitação de atividades, sintomas (somente crianças/adolescentes) e função emocional do Pediatric Asthma Quality of Life Questionnaire e do Pediatric Asthma Caregiver's Quality of Life Questionnaire, respectivamente. Resultados: Do total de 291 artigos identificados, 133 foram avaliados e 33 foram incluídos na meta-análise, totalizando 4.101 sujeitos. A análise estratificada por tipo de delineamento não mostrou diferenças entre a QVRS de cuidadores e de crianças/adolescentes no domínio limitação de atividades e no escore total. Contudo, houve diferenças das médias no domínio função emocional em estudos longitudinais e ensaios clínicos randomizados - estudos transversais: Δ = −0,20 (−0,03 a 0,43); estudos longitudinais: Δ = 0,82 (0,21-1,44); e ensaios clínicos randomizados: Δ = 0,52 (0,29-0,79) - sendo que os cuidadores apresentaram menores escores que as crianças/adolescentes com asma. Conclusões: Os escores da QVRS entre cuidadores e crianças/adolescentes com asma demonstraram ser semelhantes quanto aos escores totais, mas divergiram na percepção das limitações emocionais, visto que os cuidadores apresentaram escores significativamente menores que as crianças/adolescentes nesse domínio.

Pulmonary Acinus: Understanding the Computed Tomography Findings from an Acinar Perspective.

The lung acinus is the most distal portion of the airway responsible for the gas exchange. The normal acini are not visible on conventional computed tomography (CT), but the advent of micro-CT improved the understanding of the microarchitecture of healthy acini. The comprehension of the acinar architecture is pivotal for the understanding of CT findings of diseases that involve the acini. Centriacinar emphysema, for example, presents as round areas of low attenuation due to the destruction of the most central acini with compensatory enlargement of proximal acini due to alveolar wall destruction. In pulmonary fibrosis, intralobular septal fibrosis manifests as acinar wall thickening with an overlap of acinar collapse and compensatory dilation of surrounding acini constituting the cystic disease typical of the usual interstitial pneumonia pattern. This is a state-of-the-art review to describe the acinar structure from the micro-CT perspective and display how the comprehension of the acinar structure can aid in the interpretation of its microarchitecture disruption on conventional CT.

Oxidative stress in the brain of reproductive male rats during aging.

Reproduction alters the male physiology. We performed a comprehensive study to examine oxidative stress in the brains of male rats with (experienced) or without (naïve) reproductive activity during aging. Oxidative stress was assessed by measuring the activity of catalase, glutathione peroxidase, superoxide dismutase, glutathione S-transferase, aconitase, and aconitase reactivated, and by measuring lipid peroxidation, protein carbonylation, nitrite and nitrate levels, vitamin C levels, and glutathione (total, reduced, oxidized forms) levels in brain tissue, as well as testosterone and estradiol levels in serum. Reproductively active animals exhibited increased testosterone levels and aconitase activity, suggesting an increased metabolism. Increased antioxidant enzyme activities and increased levels of antioxidant compounds were observed, yet damage to biomolecules was also observed in experienced rats. During aging changes in oxidative stress were observed. We found higher activities of antioxidant enzymes, higher amounts of antioxidants, and more damage at six months of age among experienced animals than among naïve animals. Similar antioxidant activities and levels, and damage were found between the groups at twenty-four months of age. These results add comprehensive data regarding changes in oxidative stress during aging, and suggest an explanation for the costs of reproduction.

Response to oxidative stress in eight pathogenic yeast species of the genus Candida.

In the course of an infection, the formation of reactive oxygen species by phagocytes and the antioxidant defense mechanisms of microorganisms play a crucial role in pathogenesis. In this study, isolates representing 8 pathogenic Candida species-Candida albicans, Candida dubliniensis, Candida famata, Candida glabrata, Candida guilliermondii, Candida krusei, Candida parapsilosis and Candida tropicalis-were compared with regard to their resistance to oxidative stress in vitro. We evaluated degree of resistance, induction of oxidative damage, capacity to adapt, and induction of antioxidant enzymes. The species showed variable sensitivity to oxidative attack. C. albicans, C. glabrata, and C. krusei were more resistant to oxidative stress under the conditions tested; C. parapsilosis and C. tropicalis presented medium resistance; and C. dubliniensis, C. famata, and C. guilliermondii were more sensitive. The overall greater resistance to oxidative stress of C. albicans and C. glabrata may provide an advantage to these species, which are the major causative agents of candidiasis.