Physicochemical analysis of Permian coprolites from Brazil.

In this paper we performed the study of two coprolites (fossilized feces) collected from the exposed levels of the Pedra de Fogo Formation, Parnaiba Sedimentary Basin, and Rio do Rasto Formation, Paraná Sedimentary Basin, both of the Palaeozoic era (Permian age). They were characterized using X-ray diffractometry, infrared, Raman and energy dispersive spectroscopy techniques in order to aid our understanding of the processes of fossilization and to discuss issues related to the feeding habits of the animals which generated those coprolites, probably cartilaginous fishes. The results obtained using a multitechnique approach showed that although these coprolites are from different geological formations, 3000km away from each other, they show the same major crystalline phases and elemental composition. The main phases found were hydroxyapatite, silica, calcite and hematite, which lead to infer that those coprolites were formed under similar conditions and produced by a similar group of carnivore or omnivore fishes.

Endolymphatic sac drainage for the treatment of Ménière's disease.

OBJECTIVE: To describe the results obtained with endolymphatic sac drainage in patients with Ménière's disease. METHOD: A retrospective case review study was conducted of 95 Ménière's disease patients who underwent endolymphatic sac drainage in a tertiary care referral centre, after failing a long course of medical management. The main outcome measures were vertigo control and hearing preservation. RESULTS: In patients with unilateral disease, vertigo control was obtained in 94.3 per cent of patients. A significant improvement in cochlear function was seen in 14 per cent of patients, and hearing was preserved or improved in 88 per cent. For the bilateral group, vertigo control was obtained in 85.7 per cent of patients and cochlear function improved in 28 per cent. Hearing preservation was attained in 71 per cent of these patients. CONCLUSION: Endolymphatic sac drainage is a good surgical option for patients with incapacitating endolymphatic hydrops, providing a high percentage of vertigo control and hearing preservation.

Evaluation of the microgrinding procedure for the microscopic analysis of temporal bones.

INTRODUCTION: The microgrinding technique is used to study cochlear implant electrode positioning and cochlear trauma. It may be argued that this technique might cause damage to inner cochlear structures even without a cochlear implant insertion and thus it should not be recommended. Most papers do not explain how microgrinding is performed, referring to older papers for its description. Properly describing the technique and re-evaluating its safety may reassure researchers of their findings when studying trauma after cochlear implant insertion. OBJECTIVE: To accurately describe the microgrinding technique and re-evaluate its safety to assess intracochlear trauma by studying non-implanted temporal bones. METHODS: Four fresh temporal bones were removed before 24 hours postmortem and frozen at -20°C. Two were prepared for microgrinding before 24 hours of freezing and the others after 6 months. A descriptive analysis of the microscopic anatomy was performed, as well as a comparison between the bones processed within 24 hours of freezing and the bones frozen for 6 months. RESULTS: A total of 80 surfaces was evaluated. Preservation of even the most delicate intracochlear and vestibular structures was observed, such as the crista ampullaris, Reissner's and basilar membranes, permitting an adequate micro-anatomical study. Artifacts were rare and did not interfere with the analysis. Bones studied before 24 hours postmortem exhibited better quality than those frozen for 6 months. CONCLUSIONS: The microgrinding technique accurately preserves the inner ear's membranous microscopic anatomy and thus it is useful to study cochlear implant electrode positioning and trauma inside the cochlea. Studies that aim to evaluate inner ear microanatomy should be performed with fresh bones or bones frozen for less than 24 hours since they exhibit a better micro-anatomical quality.

Relevance of intracranial hypertension control in the management of Cryptococcus neoformans meningitis related to AIDS.

PURPOSE: To evaluate the relationship between intracranial hyperpressure (HICP) and mortality in patients with cryptococcal meningitis related to AIDS (CMRA). METHODS: This was an observational retrospective study. Patients were treated according to the Infectious Diseases Society of America recommendations during the evaluation period (days 0, 3, 5 and after hospitalization). High intracranial pressure (HICP) was defined as ICP values of C250 mm H20. The correlation between HICP and mortality at each of the three time points considered was investigated. Statistical analysis on the descriptive parameters and on the probability of a "death" event (odds ratio, OR) at each of those three time points was performed using the statistical software program Epidata. RESULTS: Eighty patients were included in this study, of whom 53 (66.25 %) were male. The average age of the patients was 37.5 ± 8.1 (range 22­55) years. The median CD4?lymphocyte cell count was 35 (range 0­367) cells/ml. Among the entire patient cohort, 53 patients had a favorable outcome, and the mortality rate was 33.75 %. At baseline (day 0), 57 subjects (71.5 %) presented HICP, and these patients had a higher mortality rate than those with a normal ICP, but the difference did not reach statistical significance[OR 1.65, 95 % confidence interval (CI) 0.56­4.84]. On day 3, 41 of the patients presented HICP, and HICP at this timepoint was significantly associated with an increased risk of mortality (OR 4.35, 95 % CI 1.56­12.09). On day 5, 35(43.5 %) patients presented HICP, and HCIP at this time point was also significantly associated with higher mortality (OR 7.23, 95 % CI 2.53­20.14). CONCLUSION: The results of this study confirm an association between HICP and mortality in patients with CMRA and indicate that the control of ICP during the first 5 days of hospitalization is more important than managing HICP only at baseline.