Does the force level modulate the cortical activity during isometric contractions after a cervical spinal cord injury?

ObjectiveThis study investigated the effects of a cervical spinal cord injury (SCI) on the modulation of cortical desynchronization (ERD) during isometric contractions at different force levels.MethodsFor 8 able-bodied (AB) and 6 cervical SCI participants, the net joint moment and electroencephalographic activities were recorded during isometric contractions of the right elbow in flexion and in extension at 3 force levels, that is, during intact and altered muscle contractions for SCI participants. The mean net moment and ～20 Hz ERD from C3 electroencephalographic electrode were compared between AB and SCI participants.ResultsIn flexion, that is, during intact contractions for all participants, the mean net moment and the ERD increased with the required force level. In extension, that is, during altered contractions, the mean net moment increased for 3 SCI participants while it was almost zero for 3 other SCI participants. The associated ERD increased with the required force level for all participants.ConclusionThe cortical desynchronization was modulated by the intent to modulate the force level rather than the actual modulation of the force production.SignificanceThese results provide a better understanding of the modulation of the cortical desynchronization following SCI. Potential applications could include the control of neuroprostheses.     

Isolation of the phrenic nerve to suppress diaphragmatic contraction induced by cardiac resynchronization

Left phrenic nerve stimulation is a well-known complication of cardiac resynchronization therapy (CRT). We report a case where electronic or anatomical repositioning of the left ventricular (LV) electrode (within the coronary sinus tributaries) was not feasible/effective. Surgical graft interpositioning was performed to successfully isolate the phrenic nerve from the previously implanted coronary sinus epicardial LV lead.     

The impact of lymph node status and features on oncological outcomes in urothelial carcinoma of the upper urinary tract (UTUC) treated by nephroureterectomy

Purpose

Prognostic impact of lymphadenectomy during radical nephroureterectomy (RNU) for urothelial carcinoma of the upper urinary tract (UTUC) is controversial. Our aim was to assess the impact of lymph node status (LNS) on survival in patients treated by RNU.

Methods

In our multi-institutional, retrospective database, 714 patients with non-metastatic UTUC had undergone RNU between 1995 and 2010. LNS was tested as prognostic factor for survivals through univariate and multivariable Cox regression analysis.

Results

Median age was 70 years [interquartile range (IQR), 60–75] with median follow-up of 27 months (IQR, 10–50). Overall, lymphadenectomy was performed in 254 patients (35.5 %). Among these patients, 204 (80 %) had negative lymph nodes (pN0) and 50 (20 %) had positive lymph nodes (pN1/2). The 5-year cancer-specific survival (CSS) was 81 % [95 % confidence interval (CI), 73–88 %] for pN0 patients, 85 % (95 % CI, 80–90 %) for pNx patients and 47 % (95 % CI, 24–69 %) for pN1/2 patients (p < 0.001). Metastasis-free survival (MFS) and overall survival (OS) rates were significantly lower in pN1/2 patients than in pN0 and pNx patients (p < 0.05). On multivariable analysis, LNS did not appear as an independent prognostic factor for CSS, OS or MFS (p > 0.05). In case of lymph node involvement, extra-nodal extension was marginally associated with worse CSS (log rank p = 0.07). The retrospective design was the main limitation.

Conclusion

LNS is helpful for survival stratification in patients treated with RNU for UTUC. However, LNS did not appear as an independent predictor of survival in this retrospective series and needs to be investigated in a large multicentre, prospective evaluation.     

How to successfully implement a robotic pediatric surgery program: lessons learned after 96 procedures

Background

Both our teams were the first to implement pediatric robotic surgery in France. The aim of this study was to define the key points we brought to light so other pediatric teams that want to set up a robotic surgery program will benefit.

Methods

We reviewed the medical records of all children who underwent robotic surgery between Nov 2007 and June 2011 in both departments, including patient data, installation and changes, operative time, hospital stay, intraoperative complications, and postoperative outcome. The department’s internal organization, the organization within the hospital complex, and cost were evaluated.

Results

A total of 96 procedures were evaluated. There were 38 girls and 56 boys with average age at surgery of 7.6 years (range, 0.7–18 years) and average weight of 26 kg (range, 6–77 kg). Thirty-six patients had general surgery, 57 patients urologic surgery, and 1 thoracic surgery. Overall average operative time was 189 min (range, 70–550 min), and average hospital stay was 6.4 days (range, 2–24 days). The procedures of 3 patients were converted. Median follow-up was 18 months (range, 0.5–43 months). Robotic surgical procedure had an extra cost of €1934 compared to conventional open surgery.

Conclusions

Our experience was similar to the findings described in the literature for feasibility, security, and patient outcomes; we had an overall operative success rate of 97 %. Three main actors are concerned in the implementation of a robotic pediatric surgery program: surgeons and anesthetists, nurses, and the administration. The surgeon is at the starting point with motivation for minimally invasive surgery without laparoscopic constraints. We found that it was possible to implement a long-lasting robotic surgery program with comparable quality of care.     

Identification and characterization of novel PDYN mutations in dominant cerebellar ataxia cases

We have recently identified missense mutations in prodynorphin (PDYN), the precursor to dynorphin opioid peptides, as the cause for spinocerebellar ataxia (SCA23) in Dutch ataxia cases. We report a screen of PDYN for mutations in 371 cerebellar ataxia cases, which had a positive family history; most are of French origin. Sequencing revealed three novel putative missense mutations and one heterozygous two-base pair deletion in four independent SCA patients. These variants were absent in 400 matched controls and are located in the highly conserved dynorphin domain. To resolve the pathogenicity of the heterozygous variants, we assessed the peptide production of the mutant PDYN proteins. Two missense mutations raised dynorphin peptide levels, the two-base pair deletion terminated dynorphin synthesis, and one missense mutation did not affect PDYN processing. Given the outcome of our functional analysis, we may have identified at least two novel PDYN mutations in a French and a Moroccan SCA patient. Our data corroborates recent work that also showed that PDYN mutations only account for a small percentage (~0.1 %) of European SCA cases.     

Hepatitis B virus genetic variability and evolution

Hepatitis B virus has been evolving gradually over a long period of time, resulting in a large amount of genetic diversity, despite the constraints imposed by the complex genetic organization of the viral genome. This diversity is partly due to virus/host interactions and partly due to parallel evolution in geographically distinct areas. Recombination also appears to be an important element in HBV evolution. Also, human intervention in the form of mass vaccination and antiviral treatment will reduce the burden of HBV-related liver disease but may also be accelerating evolution of the virus.