Distinct Membrane Effects of Spinal Nerve Ligation on Injured and Adjacent Dorsal Root Ganglion Neurons in Rats

Background: Painful peripheral nerve injury results in disordered sensory neuron function that contributes to the pathogenesis of neuropathic pain. However, the relative roles of neurons with transected axons versus intact adjacent neurons have not been resolved. An essential first step is identification of electrophysiologic changes in these two neuronal populations after partial nerve damage.

Methods: Twenty days after spinal nerve ligation (SNL), intracellular recordings were obtained from axotomized fifth lumbar (L5) dorsal root ganglion neurons and adjacent, intact L4 neurons, as well as from control neurons and others subjected to sham-SNL surgery.

Results: Pronounced electrophysiologic changes were seen only in L5 neurons after SNL. Both A[alpha]/[beta] and A[delta] neuron types showed increased action potential duration, decreased afterhyperpolarization amplitude and duration, and decreased current threshold for action potential initiation. A[alpha]/[beta] neurons showed resting membrane potential depolarization, and increased repetitive firing during sustained depolarization developed in A[delta] neurons. The afterhyperpolarization duration in neurons with C fibers shortened after axotomy. In contrast to the axotomized L5 neurons, neighboring L4 neurons showed no changes in action potential duration, afterhyperpolarization dimensions, or excitability after SNL. Depolarization rate (dV/dt) increased after SNL in L4 A[alpha]/[beta] and A[delta] neurons but decreased in L5 neurons. Time-dependent rectification during hyperpolarizing current injection (sag) was greater after SNL in A[alpha]/[beta] L4 neurons compared with L5. Sham-SNL surgery produced only a decreased input resistance in A[alpha]/[beta] neurons and a decreased conduction velocity in medium-sized cells. In the L5 ganglion after axotomy, a novel set of neurons, consisting of 24% of the myelinated population, exhibited long action potential durations despite myelinated neuron conduction velocities, particularly depolarized resting membrane potential, low depolarization rate, and absence of sag.     

Total and methyl-mercury content in bivalves,Mytilus galloprovincialis lamarck andOstrea edulis linnaeus: Relationship of biochemical composition and body size

Bulletin of Environmental Contamination and Toxicology -     

Continuous low dose Thalidomide: a phase II study in advanced melanoma, renal cell, ovarian and breast cancer

To grow and metastasize, solid tumours must develop their own blood supply by neo-angiogenesis. Thalidomide inhibits the processing of mRNA encoding peptide molecules including tumour necrosis factor-alpha (TNF-alpha) and the angiogenic factor vascular endothelial growth factor (VEGF). This study investigated the use of continuous low dose Thalidomide in patients with a variety of advanced malignancies. Sixty-six patients (37 women and 29 men; median age, 48 years; range 33-62 years) with advanced measurable cancer (19 ovarian, 18 renal, 17 melanoma, 12 breast cancer) received Thalidomide 100 mg orally every night until disease progression or unacceptable toxicity was encountered. Three of 18 patients with renal cancer showed partial responses and a further three patients experienced stabilization of their disease for up to 6 months. Although no objective responses were seen in the other tumour types, there were significant improvements in patients' sleeping (P < 0.05) and maintained appetite (P < 0.05). Serum and urine concentrations of basic fibroblast growth factor (bFGF), TNF-alpha and VEGF were measured during treatment and higher levels were associated with progressive disease. Thalidomide was well tolerated: Two patients developed WHO Grade 2 peripheral neuropathy and eight patients developed WHO grade 2 lethargy. No patients developed WHO grade 3 or 4 toxicity. Further studies evaluating the use of Thalidomide at higher doses as a single agent for advanced renal cancer and in combination with biochemotherapy regimens are warranted.     

Fulvestrant revisited: efficacy and safety of the 500-mg dose

Postmenopausal women with hormone receptor-positive advanced breast cancer are candidates for endocrine therapy. As the disease will eventually progress in most patients, it is important to investigate agents with novel modes of action to reduce the likelihood of treatment cross-resistance. Fulvestrant is an estrogen receptor antagonist with no known agonist effects that has been shown to be as effective as anastrozole following failure on tamoxifen, at the approved dose of 250 mg/mo. However, pharmacokinetic modeling and evidence of clinical efficacy in early trials, together with the favorable tolerability profile of fulvestrant 250 mg, led to suggestions that increasing the fulvestrant dose would lead to an improved benefit-risk profile. This review describes the rationale behind the development of a 500 mg/mo higher dose of fulvestrant and details relevant clinical trials, including the pivotal phase III COmparisoN of Faslodex In Recurrent or Metastatic breast cancer (CONFIRM) study. CONFIRM demonstrated a significant improvement in progression-free survival for fulvestrant 500 mg versus 250 mg in postmenopausal patients who had progressed on previous endocrine therapy. Here, we present and discuss a pooled safety analysis of CONFIRM and three further clinical studies demonstrating fulvestrant 500 mg to be well-tolerated with no evidence of dose-related adverse events. Overall, these data indicate an improved benefit-risk profile for fulvestrant 500 mg versus 250 mg following failure on prior endocrine therapy, and suggest that fulvestrant 500 mg may be considered in future as initial endocrine treatment for advanced breast cancer.     

Physicians’ attitudes about interprofessional treatment of chronic pain: family physicians are considered the most important collaborators

Scand J Caring Sci; 2013; 27; 303–310 Physicians’ attitudes about interprofessional treatment of chronic pain: family physicians are considered the most important collaborators Aims and objectives: Interprofessional collaboration is the process in which different professional groups work together to positively impact health care. We aimed to explore physicians’ attitudes toward interprofessional collaboration in the context of chronic pain management with the implication that if attitudes are not positive, appropriate interventions could be developed. Design: A quantitative attitudes study. Ethical issues: The ethical committee approved the study. Methods: A web‐based survey about interprofessional treatment of chronic pain was administered to physicians. Outcome measures were as follows: physicians’ demographic and workplace information, previous experience of working within an interprofessional team, and attitudes towards interprofessional collaboration in chronic pain management. Results: There were 90 physicians who responded to the survey. Physicians had positive attitudes towards team work in the context of chronic pain, but they were undecided about sharing their role within an interprofessional team. The family physician was singled out as the most important as well as the most common collaborator in chronic pain treatment. Interprofessional educational seminars and workshops were suggested as methods for improving interprofessional collaboration. Conclusions: Interprofessional collaboration may be enhanced with continuing medical education that will bring together different healthcare professionals, enable them to exchange experiences and learn about their potential roles within a team.     

Percutaneous embolization of persistent low-output enterocutaneous fistulas

Objectives

To present and retrospectively evaluate the technique of percutaneous embolization of chronic enterocutaneous fistulas (ECFs) using n-butyl-2-cyanoacrylate and Lipiodol under fluoroscopic guidance.

Methods

Six patients with a total of seven post-operative low-output ECFs of the large intestine were treated. After fistulography a hydrophilic guide wire and a catheter were advanced through the ECF into the intestine. After dilation of the bowel with saline and contrast medium, the catheter was withdrawn into the enteric orifice and glue together with Lipiodol was injected while simultaneously pulling the catheter.

Results

Complete closure of all seven fistulas was achieved. There were no peri-procedural complications. In one patient 1?month following embolization a low-output enteric discharge was observed, but the ECF spontaneously healed 5?days later. In one patient 18?months after the embolization a new perforation due to diverticulitis close to the embolization site occurred and resection of the sigmoid colon was performed. One patient needed reoperation due to a recurrence of rectal carcinoma.

Conclusions

In our series of patients, the presented technique of percutaneous embolization proved to be efficacious and easy to perform. It may have potential as a first-line treatment of low-output ECFs but a prospective study with a larger series of patients and a longer follow-up is required.

Key Points

? Patients with low-output fistulas have recurrent infections and reduced quality of life. ? Surgical treatment is complex with a relatively high morbidity and occasional mortality. ? Several percutaneous and endoscopy treatments have previously been proposed with mixed results. ? Hydrophilic guide wires and hydrophilic catheters offer new potential treatment options. ? Sealing the fistula with cyanoacrylate glue and Lipiodol seems potentially efficacious.     

Role of mitotic, pro-apoptotic and anti-apoptotic factors in human kidney development

The expression pattern of mitotic Ki-67 and anti-apoptotic bcl-2 proteins, as well as apoptotic caspase-3 and p53 proteins, were investigated in the human mesonephros and metanephros of 5–9 week-old human conceptuses. Apoptotic cells were additionally detected using the terminal deoxynucleotidyl transferase (TdT) nick-end labelling (TUNEL) method. Between the 5th and 7th developmental weeks Ki-67, caspase-3 and TUNEL-positive cells characterized all mesonephric structures, indicating importance of cell proliferation in the growth of the mesonephros and role of apoptosis in nephrogenesis. From the 7th week on, p53 and bcl-2 positive cells appeared in the mesonephros as well. Regressive changes in the mesonephros could be regulated by activation of p53, while bcl-2 could contribute to selective survival of some tubules giving rise to adult structures. In the early human metanephros (5–7 weeks), Ki-67 positive cells characterized all metanephric structures, indicating a role of cell proliferation in branching of the ureteric bud and in nephron formation. During the same period bcl-2, caspase-3 and TUNEL-positive cells were found only in the metanephric mesenchyme and nephrons. Bcl-2 protein probably protected nephrons from apoptosis, while caspase-3 protein controlled cell death in the mesenchyme. At later stages (7–9-weeks), appearance of p53-expressing cells could participate in further morphogenesis of the metanephric collecting system. The factors investigated had a spatially and temporally restricted pattern of appearance in developing kidneys. Changes in that pattern might lead to serious disturbances of kidney formation and function in early childhood.     

Depression of Ca2+/calmodulin‐dependent protein kinase II in dorsal root ganglion neurons after spinal nerve ligation

The enzyme calcium/calmodulin‐dependent protein kinase II (CaMKII) is associated with memory and its α isoform is critical for development of activity‐induced synaptic changes. Therefore, we hypothesized that CaMKII is involved in altered function of dorsal root ganglion (DRG) neurons after neuronal injury. To test this hypothesis, Sprague–Dawley rats were made hyperalgesic by L5 and L6 spinal nerve ligation (SNL), and changes in total phosphorylated and unphosphorylated CaMKII (tCaMKII) and phosphorylated form of its α isoform (pCaMKIIα) were analyzed using immunochemistry in different subpopulations of DRG. SNL did not induce any changes in tCaMKII between experimental groups, while the overall percentage of pCaMKIIα‐positive neurons in injured L5 DRG SNL (24.8%) decreased significantly when compared to control (41.7%). SNL did not change the percentage of pCaMKIIα/N52 colabeled neurons but decreased the percentage of N52‐negative nonmyelinated neurons that expressed pCaMKIIα from 27% in control animals to 11% after axotomy. We also observed a significant decrease in the percentage of small nonpeptidergic neurons labeled with IB4 (37.6% in control vs. 4.0% in L5 SNL DRG), as well as a decrease in the percentage of pCaMKIIα/IB4 colabeled neurons in injured L5 DRGs (27% in control vs. 1% in L5 DRG of SNL group). Our results show that reduction in pCaMKIIα levels following peripheral injury is due to the loss of IB4‐positive neurons. These results indicate that diminished afferent activity after axotomy may lead to decreased phosphorylation of CaMKIIα. J. Comp. Neurol. 518:64–74, 2010. © 2009 Wiley‐Liss, Inc.