Mechanisms of tizanidine action on spasticity

This investigation estimated the mechanisms of tizanidine action on spasticity using a battery of neurophysiological methods. Thirty patients with old post-stroke spastic hemiparesis took part in the investigation. They were treated with tizanidine-mean daily dose 15.8 ± 5.6 mg for a mean of 23.3 ± 4.8 days. A questionnaire for assessment of subjective improvement after treatment used a 5-point scale. For standardization of the neurological examination 5-point scales were used to assess muscle tone, muscle force and tendon reflexes. A battery of neurophysiological methods was used to analyze different mechanisms of spasticity: for alpha motoneuron excitability – the F wave parameters; for presynaptic inhibition – the ratio of H reflex amplitudes before and after vibration of the achilles tendon (Hvibr/Hmax); for common interneuron activity – the flexor reflex parameters. Our results revealed that tizanidine reduces spastically increased muscle tone, but has no influence on muscle force, tendon reflexes, Babinski sign and ankle clonus. Tizanidine is supposed to act by increasing the presynaptic inhibition and decreasing of alpha motoneuron excitability. When spasticity has decreased presynaptic inhibition and increased motoneuron excitability, it is better to treat with tizanidine.     

Comparison of various methods of plastic surgery of radiation injuries

The authors possess experience in surgical treatment of 29 patients with radiation damages of various localization. They compare the efficacy of various methods of plastic surgery of tissue defects, namely, autotransplantation of the greater omentum, transplantation of free tissue flaps, the use of transfer musculocutaneous flaps. The authors suggest a classification of the methods used and the indications for their application. Complete clinical recovery was achieved in 21 patients.     

Biological activity of tissue flaps in the treatment of complicated irradiation wounds

Within the last ten years, 79 patients were treated for 114 chronically contaminated, intractable irradiation wounds using various methods of the modern plastic surgery. Radical excision of the devitalised contaminated tissue has been impracticable in 25 cases due to the risk of life-threatening complications or significant functional loss. Different types of flaps such as cutaneous, fasciocutaneous, musculocutaneous, split muscle, isolated vascularised fascia and greater omentum have been used. Despite the incomplete excision, 84% of wounds healed primarily. The essential factor for good wound healing seems to be the biologic activity (BA) of the flap's deep tissue layer that directly contacts the wound bed. BA includes density of the vascular net, ability of neovascularisation, plasticity and specific immunological capacities. It seems to be possible to classify the flaps according to the BA level. Tissue defects in which the chances for radical debridement are poor need the highest BA level in the flap reconstruction.Presented to the European Congress on Wound Healing and Skin Physiology, Bochum, Germany, 1992     

Clinical and electromyographic characteristics of tremor in patients with depression

The aim of this investigation was to establish the clinical and electromyographic pattern of tremor in patients with depression.Twenty-eight patients with depression and tremor and 30 patients with tremor and generalized anxiety disorder were investigated. Tremor was scored clinically by the Webster Tremor Scale. Electromyographic examination of tremor activity from antagonistic hand muscles was performed.Our results revealed in both groups of patients a postural and kinetic tremor with characteristics of an enhanced physiological tremor. Tremor involved only both upper limbs and no other body parts in all patients.In conclusion tremor in depression and generalized anxiety disorder is an enhanced physiological tremor.     

Clinical and electromyographic characteristics of tremor in patients with generalized anxiety disorder

The tremor in patients with anxiety was supposed to be an enhanced physiological tremor. However no detailed clinical and electromyographic examination of tremor in patients with anxiety has been published. It has been also supposed that propranolol or benzodiazepines may influence the tremor The aim of this investigation was to establish the clinical and electromyographic pattern of tremor in patients with anxiety and to compare the effects of propranolol and alprazolam treatment. One hundred and twenty patients with tremor and generalized anxiety disorder were investigated. Tremor was scored clinically by the Webster Tremor Scale. Electromyographic examination of tremor activity from antagonistic hand muscles was performed. Sixty patients were treated with alprazolam and propranolol, in an open, crossover design, while the other sixty patients received no particular treatment for the tremor The patients were randomly assigned to treatment with propranolol, alprazolam, or received no tremor treatment. Our results revealed a postural and kinetic tremor with characteristics of an enhanced physiological tremor. Tremor involved only upper limbs and no other body parts. Treatment with propranolol or alprazolam had similar favorable effect on tremor. In conclusion tremor in generalized anxiety disorder is an enhanced physiological tremor The kinetic tremor disturbs patients and particular tremor treatment with propranolol or alprazolam should be applied.     

Ion Microprobe Study of the Polarization Quenching Techniques in Single Crystal Diamond Radiation Detectors

Synthetic single crystal diamond grown using the chemical vapor deposition technique constitutes an extraordinary candidate material for monitoring radiation in extreme environments. However, under certain conditions, a progressive creation of space charge regions within the crystal can lead to the deterioration of charge collection efficiency. This phenomenon is called polarization and represents one of the major drawbacks associated with using this type of device. In this study, we explore different techniques to mitigate the degradation of signal due to polarization. For this purpose, two different diamond detectors are characterized by the ion beam-induced charge technique using a nuclear microprobe, which utilizes MeV energy ions of different penetration depths to probe charge transport in the detectors. The effect of polarization is analyzed by turning off the bias applied to the detector during continuous or discontinuous irradiation, and also by alternating bias polarity. In addition, the beneficial influence of temperature for reducing the effect of polarization is also observed. Finally, the effect of illuminating the detector with light is also measured. Our experimental results indicate that heating a detector or turning off the bias, and then applying it during continuous irradiation can be used as satisfactory methods for recovering the CCE value close to that of a prepolarized state. In damaged regions, illumination with white light can be used as a standard method to suppress the strength of polarization induced by holes.