Search PubMed⌕ Search

Biomedical subjects

D Aguilar

Publications and source records attributed to D Aguilar.

43 records · Page 3Linked to original sources
PubMedDate not supplied

Persistence of DNA from Mycobacterium tuberculosis in superficially normal lung tissue during latent infection.

BACKGROUND: A third of the world's population has latent infection with Mycobacterium tuberculosis, and in areas of low endemicity, most cases of active tuberculosis arise as a result of reactivation of latent bacilli. We sought to establish the cellular location of these latent organisms to facilitate their elimination. METHODS: We applied in-situ PCR to sections of macroscopically normal lung tissue from 13 individuals from Ethiopia and 34 from Mexico who had died from causes other than tuberculosis. Sections of lung tissue from six Norwegian individuals (ie, individuals from a non-endemic population) acted as negative controls, and six Ethiopian tuberculosis cases acted as positive controls. FINDINGS: Control necropsy samples from the Norwegian individuals were all negative by in-situ PCR and conventional PCR, whereas all samples from known Ethiopian tuberculosis cases were positive by both methods. However, in macroscopically normal lung tissue from Ethiopian and Mexican individuals without tuberculous lesions, the in-situ PCR revealed five of 13 and ten of 34 positive individuals, respectively. These results were confirmed by conventional PCR with extracted DNA. Positive cells included alveolar and interstitial macrophages, type II pneumocytes, endothelial cells, and fibroblasts. INTERPRETATION: M. tuberculosis can persist intracellularly in lung tissue without histological evidence of tuberculous lesions. M. tuberculosis DNA is situated not only in macrophages but also in other non-professional phagocytic cells. These findings contradict the dominant view that latent organisms exist in old classic tuberculous lesions, and have important implications for strategies aimed at the elimination of latent and persistent bacilli.

Adolescent↗
PubMedDate not supplied

[Diagnosis of mesial temporal sclerosis with magnetic resonance imaging].

INTRODUCTION: Mesial temporal sclerosis (MTS) is a progressive drug-resistant epileptic syndrome which requires rapid, effective diagnosis and treatment. Histologically there is atrophy and gliosis of the hippocampus. OBJECTIVE: To establish magnetic resonance (MR) imaging guidelines for correct diagnosis. PATIENTS AND METHODS: We made a prospective study of 78 patients with drug-resistant temporal lobe epilepsy (44 women and 34 men; age 6-66 years, mean 31 years). Using a magnet of 1.5 Teslas paracoronal sections were made of the hippocampus with T1 volumetric with inversion-recovery, FLAIR (fluid-attenuated inversion-recovery) and T2 relaxometry. A control group of 30 healthy volunteers was established. The reduction in volume and hippocampal T2 hyperintensity were considered to be MTS diagnosed on MR. RESULTS: No hippocampal differences were observed among the healthy volunteers. The confidence intervals (mean +/- 1.96 SD) were: right volume: 4.169-5.911 mm3; left volume: 4.097-5.940 mm3; time of T2 relaxation: 98-113 ms. MTS was observed in 42 patients (54%): 24 left, 14 right and four asymmetrical bilateral. The results of the diagnostic validity (sensitivity/specificity) were: T1 volumetric 91/92%, FLAIR 93.5/98% and T2 relaxometry 91/92%. There was atrophy of other extrahippocampal structures in five cases of MTS; 10 patients with MTS (23.5%) had another extrahippocampal lesion associated (dual pathology), particularly migration disorders; 21 patients (27%) had lesions without MTS (tumors, alterations of migration, nonspecific gliosis) and in 15 cases (19%) there were no abnormal findings. A total of 27 patients were operated on: 22 with MTS (21 had diagnostic MR, one case had no abnormal findings), four cases had tumors and one had cortical dysplasia. CONCLUSION: The combination of quantitative techniques (T1 volumetric with inversion-recovery and T2 relaxometry) and FLAIR optimize MTS diagnosis using MR.

Adolescent↗