An experimental painful peripheral neuropathy due to nerve constriction. I. Axonal pathology in the sciatic nerve.

A constriction injury to the sciatic nerve of the rat produces a painful peripheral neuropathy that is similar to the conditions seen in man. The pathology of the sciatic nerve in these animals was examined at 10 days postinjury, when the abnormal pain sensations are near maximal severity. The nerves were examined with (1) complete series of silver-stained longitudinal sections of pieces of the nerve (3 cm or more) that contained the constriction injury in the center, (2) toluidine blue-stained semithin sections taken at least 1 cm proximal and 1 cm distal to the constriction, and (3) EM sections taken adjacent to those stained with toluidine blue. One centimeter or more proximal to the constriction, both myelinated and unmyelinated axons were all normal. Nearer to the constriction, extensive degeneration of myelinated axons became increasingly common, as did signs of endoneurial edema. Distal to the constriction, the nerve was uniformly edematous and full of myelinic degeneration. There was a profound loss of large myelinated axons and a distinctly less severe loss of small myelinated and unmyelinated axons. These observations show that at 10 days postinjury the constriction produces a partial and differential deafferentation of the sciatic nerve's territory. The absence of degeneration in the nerve 1 cm proximal to the constriction indicates the survival of the primary afferent neurons whose axons are interrupted.     

Spontaneous migration of an inferior vena cava filter resulting in cardiac tamponade and percutaneous filter retrieval.

Thromboembolic disease accounts for thousands of hospitalizations every year in the US. Its primary management consists of anticoagulation. However, in certain instances this may be contraindicated or not sufficient. Mechanic occlusion of the inferior vena cava (IVC) becomes then a viable alternative. In this case a 35-year-old man presented with a saddle pulmonary embolus but was unable to be anticoagulated due to intestinal bleed. A removable IVC filter was then placed. The filter spontaneously migrated into the right atrium causing severe tricuspid regurgitation, perforation of the atrial wall, and cardiac tamponade. The device was successfully retrieved percutaneously and the patient discharged from the hospital in stable condition. This case illustrates the potentially lethal complications associated with the use of IVC filters, as well as the possibility to percutaneously recover them from within the right atrium.     

An internet survey of 2,596 people with fibromyalgia

Background  

This study explored the feasibility of using an Internet survey of people with fibromyalgia (FM), with a view to providing information on demographics, sources of information, symptoms, functionality, perceived aggravating factors, perceived triggering events, health care utilization, management strategies, and medication use.     

Significance of the early postoperative duplex result in infrainguinal vein bypass surveillance.

BACKGROUND: Duplex surveillance of infrainguinal vein grafts may not be efficient. METHODS: Consecutive patients who had received infrainguinal vein grafts were enrolled in a duplex surveillance program. A first scan at 6 weeks after surgery categorized grafts into four groups: (a) low risk grafts, (b) mild flow disturbance, (c) intermediate stenosis and (d) critical stenosis. Disease progression was assessed over time. RESULTS: Of 364 grafts followed-up for a median of 23 months, 236 (65%) had no flow abnormality at 6-weeks, and had a 40-month cumulative patency rate of 82%. The remaining 128 (35%) grafts had a flow disturbance. Of 29 critical stenoses, 15 were repaired, 11 occluded and three did not change. Of 57 intermediate lesions, 32 progressed to critical, nine occluded, two were repaired and 14 did not change or improved. Of 42 mild lesions, 16 progressed to a higher grade, four occluded and 22 did not change or improved. There was no significant difference in graft patency between grafts with repaired stenoses and those without stenoses, but grafts with untreated critical stenoses were associated with lower patency (p<0.001). CONCLUSIONS: A duplex scan 6 weeks after operation can predict those patients who require continuing duplex surveillance.     

Seizure freedom off antiepileptic drugs after temporal lobe epilepsy surgery.

Data are limited on seizure recurrence after antiepileptic drug (AED) discontinuation in operated seizure-free patients. We reviewed seizure outcome in patients who came off AEDs after being seizure-free for 2 years following temporal lobe surgery in our center. Thirty-nine (68%) of 57 patients who discontinued AED therapy remained seizure-free. They had a younger age at surgery than the group with seizure recurrence (p=0.01). Earlier surgery may be a favorable predictor for seizure freedom after AED discontinuation.     

vCJD and blood transfusion: risk assessment in the United Kingdom.

The risk of vCJD transmission via blood transfusion depends on potential levels of infectivity, recipients' exposure to infected donors and individual susceptibility. On infectivity, SEAC (the UK's main scientific advisory committee on TSEs), has published an updated position statement. Based on animal models, this suggests that infectivity is split roughly equally between leucocytes and plasma, with negligible levels directly associated with red cells or platelets. Risk assessments are now therefore based on the amounts of plasma and leucocytes within each component as transfused. Recipients' exposure to infection depends critically on the prevalence of infection in the population. This remains unknown, so a range of assumptions must still be considered. A further consideration is the likelihood of any infected donors' blood being infective. Those infected in the primary outbreak will now have been incubating vCJD for 10-25 years. Current thinking is that blood may be more infective later in the incubation period. This reinforces the case for a precautionary approach to transmission risks, despite the small number of incidents seen so far. Exposure will also depend on how many donors contributed components to a given individual. Recent work has shown that more patients receive large numbers of units than previously thought. These highly-transfused patients are a particular cause for concern. The current precautionary assumption is of all recipients being susceptible to infection by transfusion, though incubation periods may differ markedly.     

Predictors of successful labor induction with oral or vaginal misoprostol.

OBJECTIVE: To identify independent predictors of successful labor induction with oral or vaginal misoprostol. METHODS: Women enrolled in four previous randomized trials involving oral or vaginal misoprostol for cervical ripening and labor induction were included in the present cohort study, with dosing of 25-50 microg every 4 to 6 h vaginally (n = 574) or 50 microg every 4 h orally (n = 207). Multiple logistic regression was performed to identify factors independently associated with successful labor induction -- defined as vaginal delivery within 12 h, vaginal delivery within 24 h and spontaneous vaginal delivery. Predictors of Cesarean birth and the need for only one dose of misoprostol were also identified. Variables included in the models were maternal age, weight, height, parity, gravidity, membrane status, route of misoprostol, gestational age, birth weight, and Bishop score and its individual components. RESULTS: Maternal age, height, weight, parity, birth weight, dilatation, effacement and cervical station were associated with vaginal delivery within 24 h of induction. Maternal age, height, weight, nulliparity, birth weight and route of misoprostol were associated with Cesarean birth, with oral misoprostol being associated with a lower rate of Cesarean birth. The need for only one dose of misoprostol was predicted by maternal height, weight, parity, gestational age, Bishop score and route of misoprostol. CONCLUSION: Characteristics of the woman (height, weight, parity), the fetus (birth weight) and some of the individual components of the Bishop score, were associated with successful labor induction, with oral misoprostol being associated with a lower rate of Cesarean birth.     

The synthesis and localization of alternatively spliced fibronectin EIIIB in resting and thrombin-treated megakaryocytes

There are several species of alternatively spliced fibronectin (FN). One of these, FN EIIIB, is primarily present in embryonic and in proliferating and migrating cells and is believed to be important for cell maturation. We have studied the synthesis, localization, and secretion of this FN isoform in isolated guinea pig megakaryocytes, nonmegakaryocytic bone marrow cells, and platelets. There was 7.5 times more general FN in megakaryocytes than in nonmegakaryocytic cells based on the analysis of equivalent amounts of protein. FN EIIIB was detected by Western blotting in megakaryocytes but not in nonmegakaryocytic cells present in bone marrow. Neither megakaryocytes nor platelets secreted FN EIIIB, while megakaryocytes secreted 25.3% +/- 4.6% general FN and platelets secreted about 61% general FN in response to thrombin. Analysis of immunostained cells by confocal microscopy revealed that FN EIIIB had been redistributed to the surface of megakaryocytes in response to thrombin. Synthesis was studied by metabolic labeling, and megakaryocytes were shown to synthesize FN and FN EIIIB. Thus, megakaryocytes and platelets are among a small number of adult cells and tissues that synthesize and contain FN EIIIB. The expression of FN EIIIB on the megakaryocyte surface may influence migration and maturation.