A comparison between averaged spikes and individual visually-analyzed spikes in rolandic epileptiform discharges

PURPOSE:This study compared some morphological features of individual rolandic epileptiform discharges, used to obtain an averaged estimate, with those of the resulting estimate. METHOD: Twenty-four averaged discharges from EEGs of 24 children showing rolandic spikes were compared with 480 individual discharges used in the averaging. The analysis was based on the occurrence of tangential dipole and "double spike" patterns. RESULTS: In 15 averaged discharges the tangential dipole pattern was found. Individual spikes used in the averaging process displayed the same pattern in 35-100% of them; in the remaining 9 averaged discharges, up to 20% of the individual spikes showed the same pattern, although this was not found in the averaged waveforms. "Double spike" pattern was found in 11 of the averaged waveforms and was recognized in 50-100% of its individual discharges, whereas up to 45% of individual spikes showed this pattern without expression in the averaged waveform. CONCLUSION: When visually analyzing an EEG with rolandic spikes, caution should be exercised in characterizing these patterns, since a few discharges showing them may not be expressed in the averaged waveform and the clinical correlations proposed for these patterns may not apply.     

Management of odontoid fractures using anterior screw fixation: analysis of 15 cases

A retrospective analysis of the results of 15 patients with odontoid fractures type II P and II N, according to Roy-Camille's classification is presented. They were operated on by an anterior approach and direct fixation of the odontoid process through a screw. There were 13 men and 2 women, the age ranging from 14 to 74 years. The follow up period was from 6 to 36 months (mean 20 months). There was only one complication related to the surgical technique: one screw was misplaced and it was necessary another surgery to replace it. There were no deaths in this series. There were no screw breakdown and the fusion rate was 94%. We propose, based on this study, that the classification of Roy-Camille for odontoid fractures should be always used, since it proposes one surgical approach for each type of fracture. The results of this series show that this technique is useful and has advantages over another modalities of treatment. The correct diagnosis of the type of fracture and an appropriate selection of patients are the main elements to achieve good results.     

Neuroprotective action of melatonin on neonatal rat motoneurons after sciatic nerve transection

The neuronal isoform of nitric oxide synthase (nNOS), a NADPH-dependent diaphorase, is considered to play a role in motoneuron death induced by sciatic nerve transection in neonatal rats. Neuronal loss in these circumstances has been correlated with nitric oxide (NO) production and NADPH-diaphorase positivity in motoneurons after axotomy. In the present study we looked for a possible protective effect of melatonin, an antioxidant agent and inhibitor of nNOS, on spinal motoneurons after axonal injury. Neonatal Wistar rats (P2) were submitted to sciatic nerve transection and allowed to survive to P7. Melatonin at doses of 1, 5, 10, 50 and 100 mg/kg was given subcutaneously before and at intervals after the surgery. Controls operated in the same way received dilution vehicle or no treatment. The animals were killed by perfusion of fixative and the spinal cord was examined in serial paraffin sections. The motoneurons of the sciatic pool were counted in the axotomized and contralateral sides. Immunohistochemistry for nNOS and glial fibrillary acidic protein was used to evaluate nNOS expression in the axotomized cells and the astrocytic response. We found that melatonin at doses of 1-50 mg/kg decreased neuronal death. Astrocytic hypertrophy in melatonin treated animals was less intense. There were no differences in nNOS expression between treated and control rats, and surviving motoneurons of the sciatic pool did not express the enzyme, suggesting that nNOS may not be involved in neuronal death or survival in these experimental conditions. Possible mechanisms of melatonin neuroprotection, which was equally effective at doses of 1-50 mg/kg, are discussed. Doses of 50 and 100 mg/kg caused failure to thrive, seizures or death. The fact that neuroprotective doses were far smaller than toxic ones should encourage testing of melatonin in neurologic diseases.     

Amiloride Relaxes Rat Corpus Cavernosum Relaxation In Vitro and Increases Intracavernous Pressure In Vivo

Introduction

The antihypertensive effects of thiazide diuretics such as hydrochlorothiazide are commonly associated with erectile dysfunction. The association of hydrochlorothiazide/amiloride is not associated with erectile dysfunction. The hypothesis is that amiloride has beneficial effect in penile erection and, therefore, counterbalances the hydrochlorothiazide-induced disruptive effect.

Exogenous Surfactant Preserves Lung Function and Reduces Alveolar Evans Blue Dye Influx in a Rat Model of Ventilation-induced Lung Injury

Background: Changes in pulmonary edema infiltration and surfactant after intermittent positive pressure ventilation with high peak inspiratory lung volumes have been well described. To further elucidate the role of surfactant changes, the authors tested the effect of different doses of exogenous surfactant preceding high peak inspiratory lung volumes on lung function and lung permeability.

Methods: Five groups of Sprague-Dawley rats (n = 6 per group) were subjected to 20 min of high peak inspiratory lung volumes. Before high peak inspiratory lung volumes, four of these groups received intratracheal administration of saline or 50, 100, or 200 mg/kg body weight surfactant; one group received no intratracheal administration. Gas exchange was measured during mechanical ventilation. A sixth group served as nontreated, nonventilated controls. After death, all lungs were excised, and static pressure-volume curves and total lung volume at a transpulmonary pressure of 5 cm H2 O were recorded. The Gruenwald index and the steepest part of the compliance curve (Cmax) were calculated. A bronchoalveolar lavage was performed; surfactant small and large aggregate total phosphorus and minimal surface tension were measured. In a second experiment in five groups of rats (n = 6 per group), lung permeability for Evans blue dye was measured. Before 20 min of high peak inspiratory lung volumes, three groups received intratracheal administration of 100, 200, or 400 mg/kg body weight surfactant; one group received no intratracheal administration. A fifth group served as nontreated, nonventilated controls.

Results: Exogenous surfactant at a dose of 200 mg/kg preserved total lung volume at a pressure of 5 cm H2 O, maximum compliance, the Gruenwald Index, and oxygenation after 20 min of mechanical ventilation. The most active surfactant was recovered in the group that received 200 mg/kg surfactant, and this dose reduced minimal surface tension of bronchoalveolar lavage to control values. Alveolar influx of Evans blue dye was reduced in the groups that received 200 and 400 mg/kg exogenous surfactant.     

Microbial adherence to and disinfection of laryngoscopes used in office practice

This study reports the appropriate disinfection methods for flexible and rigid laryngoscopes when used in an outpatient setting. This investigation presents evidence that an appreciable number of laryngoscopes are contaminated during use. A brief tap water rinse serves to eliminate gross soil of host origin known to interfere with disinfectant efficacy. Disinfection with 3.2% glutaraldehyde (Cidexplus) for 10 minutes effectively eliminated microbial contaminants. Since potentially harmful microorganisms were included among the more than 100 isolates during our baseline experiments, the need to eliminate bacteria, viruses, fungi, and protozoa from laryngoscopes is obvious and can be attained readily.     

Differential proteomic serum pattern of low molecular weight proteins expressed by adenocarcinoma lung cancer patients

Based on the assumption that proteins can emanate from tumour to serum, we investigated whether serum low molecular weight proteins (LMW) can discriminate lung cancer patients from healthy donors. Pooled sera from 20 lung cancer patients matched in sex (men), histological type (adenocarcinoma) and stage (IIIB and IV) and from 20 healthy donors (men) were submitted to 2-DE coupled to MALDI-TOF peptide mass fingerprinting. Results of 2D-E/ MALDI-TOF showed five up regulated proteins (immunoglobulin lambda chain, transthyretin monomer, haptoglobin-alfa 2 and two isoforms of serum amyloid protein) and one down regulated (fragment of apolipoprotein A-I) in patients. All differentially expressed proteins, except immunoglobulin, may be acting as a non-specific sign of inflammation in cancer and transthyretin monomer may act as a possible blood marker to CSF barrier disruption that occurs, e.g., in cerebral metastasis. In conclusion, this work shows the usefulness of 2D-gel electrophoresis and mass spectrometry proteomic techniques for the identification of up- and down-regulated proteins in serum from adenocarcinoma lung cancer patients.     

Pharmacological evidence for the activation of Ca2+-activated K+ channels by meloxicam in the formalin test

The possible participation of K+ channels in the antinociceptive action of meloxicam was assessed in the 1% formalin test. Local peripheral administration of meloxicam produced a dose-dependent antinociception only during the second phase of the formalin test. K+ channel blockers alone did not modify formalin-induced nociceptive behavior. However, local peripheral pretreatment of the paw with charybdotoxin and apamin (large- and small-conductance Ca2+-activated K+ channel inhibitors, respectively), 4-aminopyridine and tetraethylammonium (non-selective voltage-dependent K+ channel inhibitors), but not glibenclamide or tolbutamide (ATP-sensitive K+ channel inhibitors), dose-dependently prevented meloxicam-induced antinociception. It is concluded that meloxicam could open large- and small-conductance Ca2+-activated K+ channels, but not ATP-sensitive K+ channels, in order to produce its peripheral antinociceptive effect in the formalin test. The participation of voltage-dependent K+ channels was also suggested, but since non-selective inhibitors were used the data await further confirmation.