Ashwin N. Babu

Increased FGF-2 secretion and ability to support neurite outgrowth by astrocytes cultured on polyamide nanofibrillar matrices

An electrospun nonwoven matrix of polyamide nanofibers was employed as a new model for the capillary basement membrane at the blood-brain barrier (BBB). The basement membrane separates astrocytes from endothelial cells and is associated with growth factors, such as fibroblast growth factor-2 (FGF-2). FGF-2 is produced by astrocytes and induces specialized functions in endothelial cells, but also has actions on astrocytes. To investigate potential autocrine actions of FGF-2 at the BBB, astrocytes were cultured on unmodified nanofibers or nanofibers covalently modified with FGF-2. The former assumed an in vivo-like stellate morphology that was enhanced in the presence of cross-linked FGF-2. Furthermore, astrocyte monolayers established on unmodified nanofibers were more permissive for neurite outgrowth when cultured with an overlay of neurons than similar monolayers established on standard tissue culture surfaces, while astrocytes cultured on FGF-2-modifed nanofibers were yet more permissive. The observed differences were due in part to progressively increasing amounts of FGF-2 secreted by the astrocytes into the medium; hence FGF-2 increases its own expression in astrocytes to modulate astrocyte-neuron interactions. Soluble FGF-2 was unable to replicate the effects of cross-linked FGF-2. Nanofibers alone up-regulated FGF-2, albeit to a lesser extent than nanofibers covalently modified with FGF-2. These results underscore the importance of both surface topography and growth factor presentation on cellular function. Moreover, these results indicate that FGF-2-modified nanofibrillar scaffolds may demonstrate utility in tissue engineering applications for replacement and regeneration of lost tissue following central nervous system (CNS) injury or disease.

Is There a Relationship Between Body Mass Index and Fluoroscopy Time During Sacroiliac Joint Injection? A Multicenter Cohort Study

OBJECTIVE To determine the relationship between BMI and fluoroscopy time during intra-articular sacroiliac joint (SIJ) injections performed for a pain indication. DESIGN Multicenter retrospective cohort study. SETTING Three academic, outpatient pain treatment centers. SUBJECTS Patients who underwent fluoroscopy guided SIJ injection with encounter data regarding fluoroscopy time during the procedure and body mass index (BMI). MAIN OUTCOME MEASURE Median and 25-75% Interquartile Range (IQR) fluoroscopy time. RESULTS 459 SIJ injections (350 patients) were included in this study. Patients had a median age of 57 (IQR 44, 70) years, and 72% were female. The median BMI in the normal weight, overweight, and obese groups were 23 (IQR 21, 24), 27 (IQR 26, 29), and 35 (IQR 32, 40), respectively. There was no significant difference in the median fluoroscopy time recorded between these BMI classes (p = 0.45). First-time SIJ injection (p = 0.53), bilateral injection (p = 0.30), trainee involvement (p = 0.47), and new trainee involvement (trainee participation during the first 2 months of the academic year) (p = 0.85) were not associated with increased fluoroscopy time for any of the three BMI categories. CONCLUSIONS Fluoroscopy time during sacroiliac joint injection is not increased in patients who are overweight or obese, regardless of whether a first-time sacroiliac joint injection was performed, bilateral injections were performed, a trainee was involved, or a new trainee was involved.

Pain Reduction and Repeat Injections After Transforaminal Epidural Injection With Particulate Versus Nonparticulate Steroid for the Treatment of Chronic Painful Lumbosacral Radiculopathy

The corticosteroid choice for a lumbar transforaminal epidural steroid injection (TFESI) remains controversial. Whether to utilize particulate or nonparticulate steroid preparations for these injections remains an unanswered question in the literature.

Prevention, evaluation, and rehabilitation of cycling-related injury

The unique quality of the bicycle is its ability to accommodate a wide variety of injuries and disabilities. Cycling for recreation, transportation, and competition is growing nationwide, and has proven health and societal benefits. The demands of each type of cycling dictate the necessary equipment, as well as potential for injury. Prevention of cycling-related injury in both the athlete and the recreational cyclist involves understanding the common mechanisms for both traumatic and overuse injury, and early correction of strength and flexibility imbalances, technique errors, and bicycle fit.

Local, national, and service component cost variations in the management of low back pain: Considerations for the clinician

In the past two decades, the cost associated with managing low back pain has increased significantly. Improved consciousness of how clinicians utilize resources when managing low back pain is necessary in the current economic climate. The goal of this review is to examine the component costs associated with managing low back pain and provide practical solutions for reducing healthcare costs. This is accomplished by utilizing examples from a major metropolitan area with several major academic institutions and private health care centers. It is clear that there is considerable local and national variation in the component costs of managing low back pain, including physician visits, imaging studies, medications, and therapy services. By being well informed about these variations in ones environment, clinicians and patients alike can make strides towards reducing the financial impact of low back pain. Investigation of the cost discrepancies for services within ones community of practice is important. Improved public access to both cost and outcomes data is needed.

Hamstring injuries: review of current literature and return to play considerations

Hamstring injuries are a common source of frustration for athletes. The most commonly involved muscle is the biceps femoris, which is typically injured during forceful sprinting. Injury rates vary according to several variables including sex, level of play, and sport. There are many classification schemes used for hamstring injuries, including the more recent Munich muscle injury classification. History and physical exam remain the cornerstones of diagnosis, while the utility of magnetic resonance imaging is still debated. Most hamstring injuries are managed non-operatively, although variations in the rehabilitation protocols are seen in the literature. Severe and refractory injuries can be managed operatively with good success. The return to play decision is complex, requiring coordination of care between the athlete, coaches, trainers, physicians, and involved family members. Future research investigating new treatments and rehabilitation protocols is important and necessary to keep our athletes performing at the top of their abilities.

(471) The relationship between body mass index and fluoroscopy time during intra-articular hip injections: a multicenter cohort study

and chronic fatigue syndrome (CFS). Up to now chronic fatigue mechanisms are only partially understood and few effective therapies exist. Animal studies have shown that peripheral tissues have metabo-receptors and activation of these metabo-receptors has resulted in fatigue in laboratory animals. We have shown that individuals with chronic fatigue syndrome have sensitized metaboreceptors which become activated by tissue metabolites, thus signaling fatigue during muscle activity or even at rest. Blocking these metabo-receptors with local anesthetics could improve general fatigue of patients with CFS. Patients who fulfilled the CDC Criteria for CFS were randomized into a double blind, placebocontrolled, parallel study of injections into 4 areas of the trapezius and gluteal muscles. Patients were excluded if they had received previous muscle injections with local anesthetics. Patients received either 4 injections with 50mg of 1%lidocaine or saline. Outcome measure were overall fatigue, depression, anxiety, and pain. Patients indicated by forced choice after the injections whether they had received lidocaine or saline. 28 subjects (50.8 years) received lidocaine and 27 subjects (50.3 years) received saline injection. An ANOVA showed a significant main effect for time (p<.001) and significant interaction effects of time*group (p=.03) indicating that lidocaine was more effective for decreasing fatigue than placebo. Forced choices of participants confirmed successful blinding of participants’ drug allocation. Lidocaine injections into muscles effectively reduced overall fatigue of CFS-patients more than placebo suggesting that peripheral pathways play an important role for fatigue signaling. Local anesthetics may represent a novel approach for chronic fatigue.

Outcomes of Inpatient Rehabilitation in Patients With Simultaneous Bilateral Total Knee Arthroplasty.

The number of total knee arthroplasty (TKA) procedures performed in the United States is increasing each year, and the number of bilateral TKA procedures has also increased during the past 2 decades. However, few studies in the literature have investigated the rehabilitation outcomes of patients who undergo bilateral TKA. This study was performed to provide information on the benefits and role of inpatient rehabilitation for patients after bilateral TKA.

Unusual Electromyographic Findings Associated With Colchicine Neuromyopathy: A Case Report.

An 83‐year‐old man with multiple medical problems, including gout, pseudogout, and renal insufficiency, presented with more than a year of proximal weakness. He had an extensive previous medical workup, including a normal creatinine kinase. His weakness persisted despite endurance and strength training. Electrodiagnostic findings were consistent with a myopathy, although without abnormal spontaneous activity and a length‐dependent neuropathy. On the basis of these findings, colchicine was discontinued. The patient experienced marked symptomatic improvement within a week. Myopathies with neuropathies may be found with the use of colchicine. This case was unusual because of the absence of abnormal spontaneous activity and increased creatinine kinase, as typically reported with colchicine myopathy.

The Motivational Influence of Milestone Times on 10-km Running Performance

To date, little research has been conducted to evaluate the potentially motivating effect of completing a race at a specific “milestone” finishing time. As this is difficult to perform in a laboratory setting, we examined 10-km runners from a large cohort to see if they were more likely to complete a race before rather than after a set milestone time (40:00, 45:00, and 50:00). Frequency distributions for finishers of each sex were created in 30-second time groups, with ideal normal distributions modeled based on this data. The actual time group frequencies were compared to the “expected” values from the modeled normal distributions. We included time groups that contained at least 1,000 finishers, thus were constrained to 36:00 – 52:00 for men and 43:30 to 52:00 for women. A total of 180,731 men and 53,047 women were included in the analysis. Men showed significant positive deviations (more finishers than expected) in the 39:30-40:00, 44:30-45:00, and 48:30-50:00 time groups (3 groups); they showed significant negative deviations only at 40:00-40:30 and 50:00-50:30. Women only showed significant positive time group deviations from 48:30-50:00 (1 group) with no significant negative deviations. In conclusion, despite the relatively arbitrary nature of milestones, they appear to exert a motivational influence on 10-km runners.