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Biomedical subjects

B Navarro

Publications and source records attributed to B Navarro.

45 records · Page 3Linked to original sources

Assessment of breast cancer size: sonographic and pathologic correlation.

PURPOSE: Accurate presurgical assessment of tumor size in breast cancer is important for choosing appropriate treatment. We retrospectively compared presurgical sonographic measurements of tumor size with postsurgical measurements of size and other variables. METHODS: In 174 cases, tumor size was measured by sonography before surgery, and those measurements were compared with values obtained by histopathologic examination of the specimens. The histologic type and grade, the number of lesions, and the presence of an extensive intraductal component also were considered in the intramodal correlations of tumor size. RESULTS: Sonographic measurements of tumor size correlated well with size measured after surgery (r = 0.72; 95% confidence interval, 0.64-0.78). The correlation was higher for lesions of 20 mm or less in their longest diameter than for larger lesions. The intramodal size correlation was lower for tumors with an extensive intraductal component than for tumors without an extensive intraductal component. The sonographic versus pathologic correlation of tumor size was less accurate when several lesions were present. CONCLUSIONS: Sonography is useful for presurgical assessment of tumor size in patients with breast cancer, especially for single lesions of 20 mm or less and without an extensive intraductal component.

Adult↗

Viroids with hammerhead ribozymes: some unique structural and functional aspects with respect to other members of the group.

Viroids, subviral pathogens of plants, are composed of a single-stranded circular RNA of 246-399 nucleotides. Within the 27 viroids sequenced, avocado sunblotch, peach latent mosaic and chrysanthemum chlorotic mottle viroids (ASBVd, PLMVd and CChMVd, respectively) can form hammerhead structures in both of their polarity strands. These ribozymes mediate self-cleavage of the oligomeric RNAs generated in the replication through a rolling circle mechanism, whose two other steps are catalyzed by an RNA polymerase and an RNA ligase. ASBVd, and presumably PLMVd and CChMVd, replicate and accumulate in the chloroplast, whereas typical viroids replicate and accumulate in the nucleus. PLMVd and CChMVd do not adopt a rod-like or quasi rod-like secondary structure as typical viroids do but have a highly branched conformation. A pathogenicity determinant has been mapped in a defined region of the CChMVd molecule.

Base Sequence↗

[Epileptic crisis and multiple sclerosis: anatomo-clinical correlation].

INTRODUCTION: The prevalence of epilepsy in multiple sclerosis (MS) is low and the occurrence of an epileptic seizure as a first sign of this illness is even more infrequent. The relationship between both these illnesses is not clear; as epilepsy is a common condition, a coincidental association only could exist between the two diseases. OBJECTIVE: To establish a nexus of causality between epilepsy an MS. Clinical case. We present one case of epileptic seizures as the first manifestation of MS. The patient was a woman of 25 years old. The only result of the clinical examination was a right homonymous inferior cuadrantanopsy. The patient presented a high Tibbling index, lesions of demyelination in the subcortical occipital region and semioval centrum in the MRI and a pathological electroencephalogram; also, the visual and auditory evoked potential latency were delayed. CONCLUSIONS: We related he results of the neuroimaging, the clinical examination and the complementary tests of the patient. The appears to be a causal association between epilepsy and MS.

Adult↗