IMPACT OF STRESS FACTORS ON OPTICAL ISOMERISM OF BENAZEPRIL HYDROCHLORIDE.

Benazepril hydrochloride contains two stereogenic centers, but is currently available as single enantiomer (S,S configuration) for the treatment of hypertension. Its enantiomer (R,R configuration) and the diastereoisomeric pair (R,S and S,R) can be regarded as impurities. Stereochemical stability of S,S isomer of benazepril hydrochloride and its potential susceptibility to conversion in the.active substance and in Lisonid tablets were examinated. The separation with the use of the TLC method with the following system: chromatographic plates Chiralplate and a mobile phase: methanol - acetonitrile - 1 mM copper(II) acetate (4 : 2 : 4, v/v/v) with saturation of glacial acetic acid for 1 h and the HPLC method system: Chiral AGP column (150 x 4.0 man x 5 µm) and a mobile phase: phosphate buffer pH = 6.0 - methanol (80 : 20, v/v) were obtained. Active substance - benazepril hydrochloride and Lisonid tablets 20 mg were subjected to the impact of different stress factors. Samples were examined after 1 and 6 weeks. It was found that none of the applied stress factors caused the transformation of the S,S enantiomer of benazepril hydrochloride in the substance and tablets to other identified stereoisomers - only the compound decomposition has occurred.

Tremor in neuropathies of different origin.

BACKGROUND AND PURPOSE: Tremor accompanies some poly-neuropathies, but its prevalence and its clinical and electrophysiological manifestations are not well known. The aim of the study was to assess the occurrence and characteristics of hand tremor in patients with polyneuropathy of different origins, as well as relations between the occurrence of tremors and clinical and neurographic findings of polyneuropathy. MATERIAL AND METHODS: Eighty-nine patients diagnosed with polyneuropathy of known aetiology, and 50 age- and sex-matched healthy volunteers were included in the study. All subjects were interviewed regarding the occurrence of tremor. Tremor was assessed clinically and objectively using a triaxial accelerometer and electromyographic (EMG) recordings. A load test with a weight of 500 γ was performed in order to differentiate between enhanced physiological tremor (EPT) and essential tremor-like (ET-L) tremor. RESULTS: Tremor was found in 59.5% of patients in clinical assessment and in 74% of patients in objective evaluation, significantly more often than in controls (12%). Tremor was detected in all types of polyneuropathy apart from paraproteinaemic IgM polyneuropathy. Tremor was postural (70%), but resting (51%) or kinetic (32%) tremor was also present. In the majority of cases, the severity of the tremor was mild. Essential tremor-like tremor prevailed in the study group. The occurrence of hand tremor was not related to the axonal or demyelinating type of polyneuropathy, nor to the conduction velocity or other electrophysiological findings of the investigated upper limb nerves. CONCLUSION: Tremor accompanies 60-70% of patients with polyneuropathy; it is mostly postural, ET-L type with mild severity, and unrelated to other typical clinical and electrophysiological findings of neuropathy.

[Clinical and electrophysiological correlations concerning patients with carpal tunnel syndrome]. / Korelacje kliniczno-elektrofizjologiczne u pacjentów z zespolem ciesni nadgarstka.

BACKGROUND: Carpal tunnel syndrome (CTS) is the most commonly diagnosed nerve entrapment neuropathy. Typical clinical symptoms are pain, paresthesia or sensory deficit in the median nerve. In more severe cases the weakness and atrophy of the thenar muscles are also diagnosed. It is believed that the clinical picture along with the electrophysiological test allows making the diagnosis. However, the findings of the studies assessing the clinical and electrophysiological correlations are quite different. AIM OF THE STUDY: The aim of this study was to establish the correlations between the assessment of a neurological examination and selected parameters of standard electrophysiological tests. MATERIAL AND METHODS: In the study of 172 patients (253 nerves) with clinical symptoms of CTS, there were 131 women and 41 men at the age of 19-84 (the average: 51.28 +/- 17 years). All the patients underwent standard electrophysiological tests, according to the guidelines of the American Academy of Neurology, the test assessing the sensory latency at the wrist to the second finger (SL-D2) and the test assessing the motor latency at the wrist to the abductor pollicis brevis (DML-APB) and additional D4M-D4U test. RESULTS: In the neurological examination the most common findings were the sensory deficits in the median nerve (87%) and the weakness of the thenar muscles (71%). Less common was the atrophy of the thenar muscles (25%). Abnormal results, leading to the electrophysiological diagnosis of CTS, were shown in 194 cases (77%) under the SL-D2 test and in 170 cases (67%) under the DML-APB test. Abnormal D4M-D4U test result was found in 94% of patients. In the group of patients we established a statistically valid correlation between the sensory deficit and the results of the SL-D2 test as well as between the weakness of the thenar muscles and the results of the DML-APB test, which indicates the diagnostic value of these parameters. CONCLUSIONS: The discrepsancies lie in the different criteria for the selection of patients, the statistical methods applied, the selection of clinical scales as well as neurophysiologic testS.