Expression of AT1 and AT2 angiotensin receptors in astrocytomas is associated with poor prognosis.

Astrocytomas develop intense vascular proliferation, essential for tumour growth and invasiveness. Angiotensin II (ANGII) was initially described as a vasoconstrictor; recent studies have shown its participation in cellular proliferation, vascularisation, and apoptosis. We conducted a prospective study to evaluate the expression of ANGII receptors - AT1 and AT2 - and their relationship with prognosis. We studied 133 tumours from patients with diagnosis of astrocytoma who underwent surgery from 1997 to 2002. AT1 and AT2 were expressed in 52 and 44% of the tumours, respectively, when determined by both reverse transcriptase-polymerase chain reaction and immunohistochemistry. Ten per cent of low-grade astrocytomas were positive for AT1, whereas grade III and IV astrocytomas were positive in 67% (P<0.001). AT2 receptors were positive in 17% of low-grade astrocytomas and in 53% of high-grade astrocytomas (P=0.01). AT1-positive tumours showed higher cellular proliferation and vascular density. Patients with AT1-positive tumours had a lower survival rate than those with AT1-negative (P<0.001). No association to survival was found for AT2 in the multivariate analysis. Expression of AT1 and AT2 is associated with high grade of malignancy, increased cellular proliferation, and angiogenesis, and is thus related to poor prognosis. These findings suggest that ANGII receptors might be potential therapeutic targets for high-grade astrocytomas.

[Determination of systemic infections due to Mycoplasma in patients with clinically defined amyotrophic lateral sclerosis]. / Determinación de infecciones sistémicas por Mycoplasma en pacientes con esclerosis lateral amiotrófica clínicamente definida.

INTRODUCTION: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease of unknown origin which has been linked to chronic infections due to intracellular microorganisms. AIMS: The purpose of this study was to identify species of Mycoplasma in blood samples from patients with clinically defined ALS by means of the polymerase chain reaction (PCR) method in comparison to healthy control subjects. PATIENTS AND METHODS: We conducted a case-control study involving 75 participants, 20 of whom were patients with clinically defined ALS and 55 healthy controls. Venous blood samples were taken and processed in the Neuroimmunology Laboratory, where they were submitted to the PCR test for Mycoplasma sp. RESULTS: The patients with ALS were between 35 and 82 years old (mean: 52.5); the ages of the healthy control subjects ranged from 35 to 60 years (mean: 44.1). After performing the PCR for Mycoplasma sp. the following results were obtained: among the patients with ALS, 10 were found to be positive (50%) and 10 were negative (50%), whereas in the control subjects we found six positives (10.91%) and 49 negatives (89.09%); these results were statistically significant (p = 0.001). On calculating the estimated risk, an odds ratio of 8167 (CI 95%: 2.4-27.6) was obtained. This indicates that the risk of suffering from ALS, if the PCR test for Mycoplasma sp. is positive, is 8:1. CONCLUSIONS: There is a strong link between suffering from a chronic infection due to Mycoplasma and developing ALS. Intracellular pathogenic agents such as Mycoplasma can play a role in the genesis of neurodegenerative diseases.

Determinación de infecciones sistémicas por Mycoplasma en pacientes con esclerosis lateral amiotrófica clínicamente definida / Determination of systemic infections due to mycoplasma in patients with clinically defined amyotrophic lateral sclerosis

Introducción. La esclerosis lateral amiotrófica (ELA) es una enfermedad neurodegenerativa de causa desconocida, que se ha relacionado recientemente con infecciones crónicas por microorganismos intracelulares. Objetivo. Identificar especies de Mycoplasma en muestras de sangre de pacientes con ELA clínicamente definida, por medio del método de reacción en cadena de polimerasa (PCR) en comparación con controles sanos. Pacientes y métodos. Realizamos un estudio de casos y controles que incluía a 75 participantes, 20 pacientes con ELA clínicamente definida y 55 controles sanos. Se tomaron muestras de sangre venosa y se procesaron en el Laboratorio de Neuroinmulogía, donde se sometieron a la prueba de PCR para Mycoplasma sp. Resultados. Los pacientes con ELA tuvieron un rango de edad entre 35 y 82 años (media: 52,5); los sujetos control entre 35 y 60 años (media: 44,1). Después de realizar la PCR para Mycoplasma sp., se obtuvieron los siguientes resultados: en los pacientes con ELA, 10 resultaron positivos (50%) y 10 negativos (50%), mientras que en los controles tenemos seis positivos (10,91%) y 49 negativos (89,09%), y se obtuvo significación estadística (p = 0,001). Al calcular el riesgo estimado, se obtiene un odds ratio de 8,167 (IC 95%: 2,4-27,6), lo cual indica que el riesgo de padecer ELA, si resulta positiva la prueba de PCR para Mycoplasma sp., es de 8:1. Conclusiones. Existe una fuerte asociación entre padecer una infección crónica por Mycoplasma y desarrollar ELA. Agentes patógenos intracelulares como Mycoplasma pueden desempeñar una función en la génesis de enfermedades neurodegenerativas (AU)

Introduction. Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease of unknown origin which has been linked to chronic infections due to intracellular microorganisms. Aims. The purpose of this study was to identify species of Mycoplasma in blood samples from patients with clinically defined ALS by means of the polymerase chain reaction (PCR) method in comparison to healthy control subjects. Patients and methods. We conducted a case-control study involving 75 participants, 20 of whom were patients with clinically defined ALS and 55 healthy controls. Venous blood samples were taken and processed in the Neuroimmunology Laboratory, where they were submitted to the PCR test for Mycoplasma sp. Results. The patients with ALS were between 35 and 82 years old (mean: 52.5); the ages of the healthy control subjects ranged from 35 to 60 years (mean: 44.1). After performing the PCR for Mycoplasma sp. the following results were obtained: among the patients with ALS, 10 were found to be positive (50%) and 10 were negative (50%), whereas in the control subjects we found six positives (10.91%) and 49 negatives (89.09%); these results were statistically significant (p = 0.001). On calculating the estimated risk, an odds ratio of 8167 (CI 95%: 2.4-27.6) was obtained. This indicates that the risk of suffering from ALS, if the PCR test for Mycoplasma sp. is positive, is 8:1. Conclusions. There is a strong link between suffering from a chronic infection due to Mycoplasma and developing ALS. Intracellular pathogenic agents such as Mycoplasma can play a role in the genesis of neurodegenerative diseases (AU)