Isokinetic muscle strength assessment of lower limbs in diabetic neuropathy

Motor dysfunction is a late and rare feature in diabetic distal sensory polyneuropathy. Early impairment of motor function in diabetic sensory neuropathy is largely unknown. We studied sixty patients with diabetic distal polyneuropathy, 30 patients with subclinical and 30 with clinical overt diabetic neuropathies. Thirty age and sex matched healthy subjects were used as a control group. Quantitative assessment of maximal muscle strength of extensors and flexors at knee and ankle was measured by isokinetic dynamometry in all patients and control subjects. The degree of neuropathy was determined by clinical and electrophysiological studies. Maximal isokinetic muscle strength in all patients was reduced by 14% for the ankle extensors [p<0.03] and by 17% for the ankle flexors [p<0.02]. At the knee, strength of extensors and flexors was reduced by 7% [NS] and 14% [p<0.05], respectively when compared with the control group. Muscle strength was significantly reduced in clinical diabetic neuropathy when compared with the control [p<0.05]. Impaired muscle strength was closely related to the severity of neuropathy. Amplitude of the compound muscle action potential was related to the strength at the ankle [r = -0.45, p< 0.01] and knee [r = -0.42, p< 0.02]. Diabetic patients may have early muscle weakness at the ankle and knee related to the presence and severity of diabetic neuropathy. Isokinetic dynamometry is a useful tool for evaluating muscle strength in early diabetic sensory neuropathy

Interleukin-is expression in RA synovial tissue and its contribution to interferon-gamma production by synovial T-cells

Objective: To investigate the expression and function of interleukin-18 [IL-18] protein in synovial tissue [ST] of patients with rheumatoid arthritis [RA]

Methodology: IL-18 and IL-18 receptors [IL-18R] mRNA expression was detected by reverse transcription-polymerase chain reaction [RT-PCR]. Expression of IL-18 at protein level was analyzed by western plotting technique. Cytokines; [IL-18 and interferon-gamma [IFN-gamma]] in culture supernatants from ST cell organ and synovial cultures were measured by ELISA. Samples: The ST samples were taken from 29 RA patients and 23 osteoarthritis patients [OA] were included as controls

Results: Using RT-PCR, for RAST and OAST, mRNA expression of IL-18 was detected in 26 out of 29 [89.7%] RA patients and in 11 out of 23 [47.8%] OA controls. However, mRNA expression of IL-18 R alpha and beta chains were detected in 26 and 24 out of 29 [89. 7% and 82.8%] RA patients, respectively. OAST did not express ,nRNA of alpha and beta chains of IL- 18 R. In vitro study of IL-18 production by ST showed significantly higher levels in RA compared to that of OA patients [p<0.005]. Western blotting revealed that RAST expressed IL-18 more abundantly than OAST [p<0.02]. Only IL-12, but not IL-18, stimulates IFN -gamma production by RAST cells [M +/- SD=230 +/- 17 pg/ml]. However, when IL-12 was combined with IL-18, they could significantly stimulate IFN -gamma production by RAST cells [M +/- SD= 612-B5 pg/ml]. OAST cells did not respond to neither to IL- 12 alone nor when combined to IL-18

Conclusion: IL-18 is expressed in RA synovia and contributes to the production of IFN -gamma by the infiltrating T-cells. These cytokines could play a role in the synovial inflammation in RA patients