Identification of a novel HLA-DRB1*11:129 allele in a Chinese individual by sequence-based typing.

The new DRB1*11:129 allele differs from the closest matching allele HLA-DRB1*11:06:01 by one nucleotide substitution in exon 3 at position 623 (G→A).

An assessment of the osteogenic index of therapeutic exercises for stroke patients: relationship to severity of leg motor impairment.

SUMMARY: Exercise may be a viable way to promote bone health in stroke survivors. This study used the osteogenic index to evaluate the osteogenic potential of selected exercises for stroke survivors. The results show that brisk walking and stepping may be good skeletal loading exercises for this population. INTRODUCTION: Exercise may induce positive effects on bone health in stroke patients. The purpose of this study was to evaluate the osteogenic potential of selected exercises for stroke survivors. METHODS: Sixty stroke patients were categorized into group 1 (moderate to severe leg motor impairment) and group 2 (mild to moderate impairment). Each subject performed five exercises in random order: walking at self-selected speed, walking at maximal speed, stepping onto a 6-in. riser, sit-to-stand, and jumping. The peak ground reaction force (GRF) on the hemiparetic side and the number of loading cycles achieved in 1 min were determined. The osteogenic index (OI) was computed for each exercise, based on the formula: OI = Peak GRF (in body weight) x In (number of loading cycles + 1). Two-way analysis of variance was used to compare the OI among the five exercises between the two groups. RESULTS: For group 1, stepping had significantly higher OI than other exercises (p < 0.001). For group 2, both walking at maximal speed and stepping had significantly higher OI than other exercises (p < 0.001). CONCLUSIONS: Stepping had the highest OI for those with more severe leg motor impairment. Both stepping and brisk walking had superior OI for those with mild leg motor impairment.

The modelling of biological systems in three dimensions using the time domain finite-difference method: I. The implementation of the model.

A computer method has been developed which uses the time domain finite-difference (TDFD) algorithm to calculate the deposition of the electromagnetic (EM) field in three-dimensional biological models. This, the first of two papers, describes the algorithm and the computer programs developed. The method is demonstrated by calculating the penetration of the EM field from a rectangular waveguide radiating into a homogeneous model, the calculation being carried out in two dimensions for simplicity in this paper.

The dielectric properties of biological tissues: II. Measurements in the frequency range 10 Hz to 20 GHz.

Three experimental techniques based on automatic swept-frequency network and impedance analysers were used to measure the dielectric properties of tissue in the frequency range 10 Hz to 20 GHz. The technique used in conjunction with the impedance analyser is described. Results are given for a number of human and animal tissues, at body temperature, across the frequency range, demonstrating that good agreement was achieved between measurements using the three pieces of equipment. Moreover, the measured values fall well within the body of corresponding literature data.

The dielectric properties of biological tissues: III. Parametric models for the dielectric spectrum of tissues.

A parametric model was developed to describe the variation of dielectric properties of tissues as a function of frequency. The experimental spectrum from 10 Hz to 100 GHz was modelled with four dispersion regions. The development of the model was based on recently acquired data, complemented by data surveyed from the literature. The purpose is to enable the prediction of dielectric data that are in line with those contained in the vast body of literature on the subject. The analysis was carried out on a Microsoft Excel spreadsheet. Parameters are given for 17 tissue types.

The modelling of biological systems in three dimensions using the time domain finite-difference method: II. The application and experimental evaluation of the method in hyperthermia applicator design.

The three-dimensional time domain finite-difference (TDFD) method was used to design a 433 MHz circular waveguide applicator for electromagnetic hyperthermia. This applicator has a water-filled lens at one end, providing surface cooling as well as some shaping of the emergent electromagnetic field. An experimental system for scanning the EM field in three dimensions is described. The experimental data were compared with those calculated from the TDFD program and good agreement was found. A realistic three-dimensional model based on an ultrasound scan of a surface tumour was built. Both the EM field and the specific absorption rate (SAR) within the model when irradiated by the applicator were calculated.

The effects of whole-body vibration therapy on bone turnover, muscle strength, motor function, and spasticity in chronic stroke: a randomized controlled trial.

BACKGROUND: Whole-body vibration (WBV) has been used in older adults to improve bone health and neuromuscular function, and may have potential applications for stroke patients. AIM: To investigate the effects of WBV on bone turnover, leg muscle strength, motor function, and spasticity among chronic stroke patients. DESIGN: Randomized controlled trial (RCT). SETTING: Community. POPULATION: Eighty-two chronic stroke patients. METHODS: The experimental group underwent exercise training with WBV stimulation for a maximum of 15 minutes, 3 days per week for 8 weeks. The controls received the same exercises without WBV. Participants were evaluated for isokinetic knee muscle strength, serum levels of bone formation and resorption markers, spasticity and motor function of the paretic leg at baseline, immediately after the 8-week training period, and 1-month follow-up. RESULTS: Intention-to-treat analysis revealed no significant changes in levels of bone turnover markers and motor function of the paretic leg over time in both groups. Muscle strength outcomes showed no significant group×time interaction, with similar significant improvements found in both groups. Spasticity of the paretic knee was significantly reduced in the experimental group (P=0.005), but not in controls (P=0.465). No serious adverse events were reported. CONCLUSION: The WBV protocol used in this study did not induce additional effects on bone turnover, knee muscle strength and paretic leg motor function among chronic stroke patients. WBV may have potential to modulate spasticity, but this requires further investigation. CLINICAL REHABILITATION IMPACT: More study on WBV is required before it can be recommended as an adjunct treatment in rehabilitation of chronic stroke patients.

Socio-political control in urban China: changes and crisis.

This paper examines urban China's socio-political control crisis under the impact of economic reforms as an epitome of a more general social crisis. The traditional urban institutional form of socio-political control in the People's Republic of China (PRC), the work unit form of control, is a variant of age-old forms. The latter's reproduction in variant form in the former was premised upon the fact that the PRC's industrialization was carried out by a peasant-based party creating a new working class of rural migrants engaged in non-market production and exchange. The persistence of non-market economic relations ensured this form of control's continued reproduction. Post-1978 market-oriented reforms have undermined this form. As the emergence of new forms has been slow, a socio-political control crisis has arisen, at a time when millions of urban employees are being thrown out of work. In dealing with the crisis, the official trade union, an organic constituent institution of the work unit form of control, plays a prominent part, in being given the tasks of sustaining this decaying form, and preventing and defusing potential social explosion. Yet, the very economic reform programme that has undermined the work unit form of control, is also gravely weakening the union.

SAR and temperature changes in the leg due to an RF decoupling coil at frequencies between 64 and 213 MHz.

Specific absorption rate (SAR) due to a butterfly surface coil in a realistic model of the leg was calculated for frequencies 64 < or = v < or = 213 MHz. The resulting temperature distribution and temperature changes (deltaT) were found using the bioheat transfer equation. To compare results at different frequencies, the minimum B-field within the coil's footprint in the plane parallel to the coil but displaced 50 mm from it was kept constant. To achieve the same minimum B-field as that associated with operation at 64 MHz that was compliant with safety guidelines (peak SAR in 1 cm3 of tissue of 2.3 W/kg), it was predicted that SAR would exceed recommended levels when v > or = 149 MHz. The corresponding maximum deltaT at 64, 128, and 213 MHz were 0.3, 1.3, and 5.0 degrees C, respectively.

Electromagnetic and thermal modeling of SAR and temperature fields in tissue due to an RF decoupling coil.

The finite difference time domain method is used to calculate the specific absorption rate (SAR) due to a butterfly surface coil in a realistic tissue model of the leg. The resulting temperature distribution and temperature changes are found using a finite difference solution to the bioheat transfer equation. Reasonable agreement is found between predicted temperature changes and those measured in vivo provided that the resulting hyperthermia does not induce noticeable changes in perfusion. The method is applicable to radiofrequency dosimetry problems associated with high Bo field magnetic resonance systems and where knowledge of spatial variation in SAR is important in assessing the safety of new magnetic resonance procedures.