Simultaneous determination of chlorthalidone and spironolactone with univariate and multivariate calibration: wavelength range selection

Chlorthalidone and spironolactone were determined simultaneously with the aid of univariate and multivariate calibration methods. Univariate calibration was performed by the zero-crossing and derivative ratio spectrum methods. Extensive spectral overlap and the scarcity of wavelengths in derivative spectra allowing one analyte to be distinguished and quantitated in the presence of the other gave rise to poor results that called for multivariate calibration. Partial least-squares regression was used in combination with a suitable method for selecting the optimum wavelength range and number of factors for analysis. The ensuing method was applied to simultaneous determination of chlorthalidone and spironolactone in a commercially available pharmaceutical preparation. The results were validated by high-performance liquid chromatography.

Neurophysiological evaluation of sexual dysfunction in familial amyloidotic polyneuropathy--Portuguese type

Familial amyloidotic polyneuropathy (FAP)--Portuguese type, is an autosomal dominant polyneuropathy related with an abnormal transthyrretin (TTR Met 30). In males, the first complaint can be sexual dysfunction. Fifteen FAP patients, mean age 37 +/- 7.7 years, mean disease duration 5.2 +/- 2.2 years, all males, complaining of sexual dysfunction were studied with pudendal evoked potentials (PEP), bulbocavernous reflex (BCR) and sympathetic skin response (SSR). PEP and BCR reflect the central somatosensory pathways and sacral arch functioning; SSR relates with autonomic pathways. The aims of this study were: to correlate clinical and EMG scores with somatic and autonomic fibres involvement; to evaluate the timing of somatic and autonomic nerves lesion in disease evolution. Results showed: that PEP and BCR abnormalities have a statistically significant correlation with clinical and EMG scores; abnormal SSR in the plant precede other clinical or EMG abnormalities in the present study.

A new method for reproducible coil positioning in transcranial magnetic stimulation mapping

A new method is presented for mapping the motor cortex by transcranial magnetic stimulation in which the position of the stimulation coil on the scalp is measured using a 3D digitizer. The reproducibility of the method was tested by mapping 3 times the left abductor digiti minimi of 6 right-handed subjects and calculating the position of the centre of gravity (CoG), the area and volume of the individual maps. For individual maps, the coordinates of the CoG were found to be reproducible within +/-3 mm and the map areas and normalized volumes to within +/-20%, when the induced current flows anteriorly. Six more subjects were mapped to estimate interindividual variability of the position of the CoG. The method's ability to differentiate the cortical representation of two close muscles was successfully tested by mapping the flexor carpi radialis and the biceps brachii in another subject. Coordinates are given in a Cartesian frame of reference defined by the two tragi and the nasion. This feature will facilitate the comparison of results and their superposition on MR images.

[The Miller Fisher syndrome. Review of the cases of the Santa Maria Hospital]

A benign syndrome of acute ophthalmoplegia, ataxia, and areflexia is commonly known as the Miller Fisher syndrome. It is generally believed that Miller Fisher syndrome is a type of Guillain-Barré syndrome, but several authors believe it to be a separate clinical entity caused by a central nervous system lesion. Eight patients with Miller Fisher syndrome diagnosis, admitted to our department in the last 20 years, were reviewed. Neurophysiological studies were carefully reviewed. Our patients had a clinical presentation and evolution identical to that described previously. Neurophysiological abnormalities were found in all patients and were characteristic of a sensory axonal neuropathy, with damage of the facial nerves and occasional demyelination of peripheral nerves. The pattern of abnormalities is distinct from the usual features seen in Guillain-Barré syndrome. The CT scan, MRI, and Evoked Potentials investigations in our patients did not confirm central nervous system lesion. Nevertheless we did not exclude the possibility of coexisting damage to the central nervous system in some patients, as shown in Chronic Inflammatory Demyelinating Polyneuropathy.

[Neurophysiological methods for the diagnosis of genitourinary dysfunctions]

Genito-urinary function is a watershed field interesting several areas of medical concern. Neurophysiological studies allow objective assessment of central, peripheral and autonomic pathways in the nervous system contributing to topographical localisation of lesions. The authors describe different methods used, namely somatosensory evoked potentials by pudendal nerve stimulation, bulbo-cavernous reflex, cutaneous sympathetic reflex, transcranial cortical or spinal magnetic stimulation and single fiber EMG. Abnormalities in neurological diseases are presented.

Octreotide--a new treatment for diarrhoea in familial amyloidotic polyneuropathy

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