Risk of Nongenitourinary Cancers in Patients With Spinal Cord Injury: A Population-based Cohort Study.

Little information is available regarding the risk of nongenitourinary (GU) cancers in patients with spinal cord injury (SCI). The authors conducted a nationwide population-based study to investigate whether a higher risk of non-GU cancer is seen among patients with SCI.Data retrieved from the National Health Insurance Research Database of Taiwan were used in this study. A total of 41,900 patients diagnosed with SCI between 2000 and 2011 were identified from the National Health Insurance Research Database and comprised the SCI cohort. Each of these patients was randomly frequency matched with 4 people from the general population (without SCI) according to age, sex, comorbidities, and index year. Cox proportional hazards regression analysis was used to calculate adjusted hazard ratios and 95% confidence intervals and determine how SCI affected non-GU cancer risk.No significant difference in overall non-GU cancer risk was observed between the SCI and control groups. The patients with SCI exhibited a significantly higher risk of developing esophageal, liver, and hematologic malignancies compared with those without SCI. By contrast, the SCI cohort had a significantly lower risk of colorectal cancer compared with the non-SCI cohort (adjusted hazard ratio = 0.80, 95% confidence interval = 0.69-0.93). Additional stratified analyses by sex, age, and follow-up duration revealed various correlations between SCI and non-GU cancer risk.The patients with SCI exhibited higher risk of esophageal, liver, and hematologic malignancies but a lower risk of colorectal cancer compared with those without SCI. The diverse patterns of cancer risk among the patients with SCI may be related to the complications of chronic SCI.

Time-course effect of electrical stimulation on nerve regeneration of diabetic rats.

BACKGROUND: Electrical stimulation (ES) has been shown to promote nerve regeneration in rats with experimental diabetes induced using streptozotocin (STZ). However, the time-course effect of ES on nerve regeneration of diabetic animals has not been reported in previous studies. The present study attempted to examine the effect of different timing of ES after peripheral nerve transection in diabetic rats. METHODOLOGY/FINDINGS: Fifty Sprague-Dawley rats were used in the study. They were classified into five groups. STZ-induced diabetes was created in groups A to D. Normal animals in group E were used as the non-diabetic controls. The sciatic nerve was transected and repaired using a silicone rubber conduit across a 10-mm gap in all groups. Groups A to C received ES for 15 minutes every other day for 2 weeks. Stimulation was initiated on day 1 following the nerve repair for group A, day 8 for group B, and day 15 for group C. The diabetic control group D and the normal control group E received no ES. At 30 days after surgery in group A, histological evaluations showed a higher success percentage of regeneration across the 10-mm nerve gap, and the electrophysiological results showed significantly larger mean values of evoked muscle action potential area and amplitude of the reinnervated gastrocnemius muscle compared with group D. CONCLUSIONS/SIGNIFICANCE: It is concluded that an immediate onset of ES may improve the functional recovery of large nerve defect in diabetic animals.

Current-modulated electrical stimulation as a treatment for peripheral nerve regeneration in diabetic rats.

PURPOSE: To study if electrical stimulation (ES) can be a useful tool to improve functional recovery after neuronal injury in the peripheral nervous system. METHODS: We studied the effects of 2 Hz of percutaneous ES at different intensities of 1, 10 and 20 mA on peripheral nerve regeneration in rats with diabetes induced by streptozotocin. Non-stimulated diabetic rats were used as the sham-controls. A10-mm gap was made in the rat sciatic nerve by suturing the stumps into silicone rubber tubes and stimulation was carried out every other day for 3 weeks starting 1 week after surgery. RESULTS: After 4 weeks of recovery, the diabetic rats showed that ES of 1 mA or above could increase the cutaneous blood flow in their ipsilateral hindpaw to the injury. ES of 10 mA could improve the amplitude and the area of evoked muscle action potentials with faster target muscle reinnervation. ES of 10 mA could also ameliorate the calcitonin gene-related peptide expression in lamina I-II regions in the dorsal horn ipsilateral to the injury and the number of macrophages in the diabetic distal sciatic nerve. The impaired growth and maturation of regenerating axons in diabetic rat could be improved by ES of 10 mA or above. CONCLUSIONS: All these results lead to the conclusion that ES of 10 mA or above might be necessary to improve regeneration after a dissect lesion of the sciatic nerve in the diabetic rat.

High-frequency electrical stimulation can be a complementary therapy to promote nerve regeneration in diabetic rats.

The purpose of this study was to evaluate whether 1 mA of percutaneous electrical stimulation (ES) at 0, 2, 20, or 200 Hz augments regeneration between the proximal and distal nerve stumps in streptozotocin diabetic rats. A10-mm gap was made in the diabetic rat sciatic nerve by suturing the stumps into silicone rubber tubes. Normal animals were used as the controls. Starting 1 week after transection, ES was applied between the cathode placed at the distal stump and the anode at the proximal stump every other day for 3 weeks. At 4 weeks after surgery, the normal controls and the groups receiving ES at 20, and 200 Hz had a higher success percentage of regeneration compared to the ES groups at 0 and 2 Hz. In addition, quantitative histology of the successfully regenerated nerves revealed that the groups receiving ES at a higher frequency, especially at 200 Hz, had a more mature structure with more myelinated fibers compared to those in the lower-frequency ES groups. Similarly, electrophysiology in the ES group at 200 Hz showed significantly shorter latency, larger amplitude, larger area of evoked muscle action potentials and faster conduction velocity compared to other groups. Immunohistochemical staining showed that ES at a higher frequency could significantly promote calcitonin gene-related peptide expression in lamina I-II regions in the dorsal horn and recruit a higher number of macrophages in the diabetic distal sciatic nerve. The macrophages were found that they could stimulate the secretion of nerve growth factor, platelet-derived growth factor, and transforming growth factor-ß in dissected sciatic nerve segments. The ES at a higher frequency could also increase cutaneous blood flow in the ipsilateral hindpaw to the injury. These results indicated that a high-frequency ES could be necessary to heal severed diabetic peripheral nerve with a long gap to be repaired.

Smoking, dopamine transporter, and hand tremor.

AIM: The purpose of the study was to evaluate the relationship between the number of packs smoked per day and specific uptake ratio (SUR) in the striatum on Tc-99m TRODAT, and frequency of hand tremor. METHODS: It was a prospective, cross-sectional study. In all, 23 healthy nonsmokers and 37 current smokers were recruited in the study. All subjects underwent Tc-99m TRODAT SPECT, brain CT scan, thyroid function test, tremor measurement system, and neurologic examinations. RESULTS: There were significant differences in the SUR in the striatum on Tc-99m TRODAT and in the frequency of hand tremor in rest state and in arm extended state among nonsmokers (grade I), current smokers with less than 1 pack smoked per day (grade II), and current smokers with equal or more than 1 pack smoked per day (grade III) by ANOVA (all P < 0.001). After adjusting for age and gender, there was a significantly negative correlation between smoke grade and SUR in the striatum on Tc-99m TRODAT by multiple linear regression (ß = -0.45, P < 0.001). Smoke grade was the significant predictor for the frequency of hand tremor in rest state and in arm extended state, after adjusting for age and gender by multiple linear regression (ß = 14.70, P < 0.001; ß = 15.37, P < 0.001). CONCLUSIONS: There is a dose-response relationship between the number of packs smoked per day and SUR in the striatum, and the frequency of hand tremor. Decreased dopamine transporter binding in the striatum and increased frequency of hand tremor in smokers may have important implications for evaluating the impact of smoking on the central and peripheral nerve systems.