Chandra Somasundaram

Adventitial Neuronal Somata

Confocal analysis of the whole-mount rat mesenteric branch arteries (MBA) revealed nucleated structures with axonal processes which immunostained for calcitonin gene-related peptide (CGRP). Immunocytochemistry ruled out the possibility that these were immune elements (macrophages and mast or dendritic cells) in close proximity with nerve fibers. To test our hypothesis that β-CGRP is expressed in the rat MBA, we performed RT-PCR using total RNA isolated from the mesenteric artery arcade and intron spanning primers designed to amplify 188 bp of the β-CGRP and 333 bp of α-CGRP cDNA. The PCR yielded an amplicon of the predicted size which was cloned into the pCR 3.1 vector. DNA sequence analysis of the insert showed 100% homology with the β-CGRP cDNA, indicating that mRNA encoding β-CGRP is expressed in the vessel. To learn whether neuronal cell bodies are located in the adventitia of MBA, we performed a limited collagenase digestion of isolated segments and plated the resulting cells in Ham’s F12 medium with 10% horse serum on polyornithine-coated cover glasses. The medium was replaced after 48 h with Ham’s F12 nutrient mixture containing N2 supplement. This resulted in a mixed population of fibroblasts, a small number of smooth muscle cells and a subset of cells that sprouted axons and immunostained positively for neuronal cell adhesion molecule and CGRP antigens. Fibroblasts and smooth muscle cells did not label with these antibodies. These data demonstrate, for the first time, that a population of adventitial neuronal somata (termed ANNIES), possibly of sensory nerve origin, is located in small mesenteric arteries.

Risk factors at birth for permanent obstetric brachial plexus injury and associated osseous deformities.

Purpose. To examine the most prevalent risk factors found in patients with permanent obstetric brachial plexus injury (OBPI) to identify better predictors of injury. Methods. A population-based study was performed on 241 OBPI patients who underwent surgical treatment at the Texas Nerve and Paralysis Institute. Results. Shoulder dystocia (97%) was the most prevalent risk factor. We found that 80% of the patients in this study were not macrosomic, and 43% weighed less than 4000 g at birth. The rate of instrument use was 41% , which is 4-fold higher than the 10% predicted for all vaginal deliveries in the United States. Posterior subluxation and glenoid version measurements in children with no finger movement at birth indicated a less severe shoulder deformity in comparison with those with finger movement. Conclusions. The average birth weight in this study was indistinguishable from the average birth weight reported for all brachial plexus injuries. Higher birth weight does not, therefore, affect the prognosis of brachial plexus injury. We found forceps/vacuum delivery to be an independent risk factor for OBPI, regardless of birth weight. Permanently injured patients with finger movement at birth develop more severe bony deformities of the shoulder than patients without finger movement.

Significant improvement in nerve conduction, arm length, and upper extremity function after intraoperative electrical stimulation, neurolysis, and biceps tendon lengthening in obstetric brachial plexus patients

BackgroundProgressive loss of extension and concomitant bony deformity of the elbow are results of persistent biceps contracture in obstetric brachial plexus injury (OBPI) patients, if they do not fully recover. This adversely affects the growth and development and functions of the upper extremity.Patients and methodWe have performed biceps tendon lengthening (BTL) using a Z-plasty technique on OBPI patients aged 4 years to adulthood, who had been diagnosed with biceps tendon fixed flexion contractures. Ulnar, radial, and median nerve decompression was also performed at the same sitting. Somatosensory evoked potential (SSEP) monitoring was performed by stimulating the median and ulnar nerves at the wrist and the radial nerve over the dorsum of the hand and recording the peripheral, cervical, and cortical responses.Seven children with obstetric brachial plexus palsy with an average age of 11 years (8.7–14.2 years) were included in this report. Mean follow-up time was 7.4 months (4–11 months). All the patients in this report had the elbow flexion contractures greater than 30°.ResultsMean flexion contracture was 35° (30°–45°) preoperatively, which was improved to 0°–10° postoperatively with an average follow-up of 7 (4–11) months. This surgical procedure corrected the elbow flexion contractures, about an average of 25° and an improved length almost to normal, and improved the upper extremity functions. Neurophysiological data showed significant improvement in conduction of all three nerves tested after neurolysis. Further, median and radial nerve amplitude increase was statistically significant.ConclusionStatistically significant improvement in biceps length as well as nerve conduction was observed after the surgery. None of the children in our study lost biceps function, although weakness of the biceps is both a short- and long-term risk associated with biceps lengthening.

Identification and Characterization of Novel Perivascular Adventitial Cells in the Whole Mount Mesenteric Branch Artery Using Immunofluorescent Staining and Scanning Confocal Microscopy Imaging

A novel perivascular adventitial cell termed, adventitial neuronal somata (ANNIES) expressing the neural cell adhesion molecule (NCAM) and the vasodilator neuropeptide, calcitonin gene-related peptide (CGRP), exists in the adult rat mesenteric branch artery (MBA) in situ. In addition, we have previously shown that ANNIES coexpress CGRP and NCAM. We now show that ANNIES express the neurite growth marker, growth associated protein-43(Gap-43), palladin, and the calcium sensing receptor (CaSR), that senses changes in extracellular Ca(2+) and participates in vasodilator mechanisms. Thus, a previously characterized vasodilator, calcium sensing autocrine/paracrine system, exists in the perivascular adventitia associated with neural-vascular interface. Images of the whole mount MBA segments were analyzed under scanning confocal microscopy. Confocal analysis showed that the Gap-43, CaSR, and palladin were present in ANNIES about 37 ± 4%, 94 ± 6%, and 80 ± 10% respectively, comparable to CGRP (100%). Immunoblots from MBA confirmed the presence of Gap-43 (48 kD), NCAM (120 and 140 kD), and palladin (90–92 and 140 kD). In summary, CGRP, and NCAM-containing neural cells in the perivascular adventitia also express palladin and CaSR, and coexpress Gap-43 which may participate in response to stress/injury and vasodilator mechanisms as part of a perivascular sensory neural network.

Improvements after mod Quad and triangle tilt revision surgical procedures in obstetric brachial plexus palsy

AIM To compare outcomes of our revision surgical operations in obstetric brachial plexus palsy (OBPP) patients to results of conventional operative procedures at other institutions. METHODS We analyzed our OBPP data and identified 10 female and 10 male children aged 2.0 to 11.8 years (average age 6.5 years), who had prior conventional surgical therapies at other clinics. Of the 20 patients, 18 undergone triangle tilt, 2 had only mod Quad. Among 18 patients, 8 had only triangle tilt and 10 had also mod Quad as revision surgeries with us. We analyzed the anatomical improvements and functional modified Mallet statistically before and after a year post-revision operations. RESULTS Pre-revision surgery average modified Mallet score was 12.0 ± 1.5. This functional score was greatly improved to 18 ± 2.3 (P < 0.0001) at least one-year after revision surgical procedures. Radiological scores (PHHA and glenoid version) were also improved significantly to 31.9 ± 13.6 (P < 0.001), -16.3 ± 11 (P < 0.0002), at least one-year after triangle tilt procedure. Their mean pre-triangle tilt (yet after other surgeon’s surgeries) PHHA, glenoid version and SHEAR were 14.6 ± 21.7, -31.6 ± 19.3 and 16.1 ± 14.7 respectively. CONCLUSION We demonstrate here, mod Quad and triangle tilt as successful revision surgical procedures in 20 OBPP patients, who had other surgical treatments at other clinics before presenting to us for further treatment.

Surgical Management of Obstetric Brachial Plexus Palsy Secondary Deformities

OBPI occurs during delivery process. The incidence of OBPI has been reported to vary between 0.38 and 5.8 for every 1000 live births [1-5]. The occurrence has increased despite the advances in obstetrics, and medical technology [6, 7]. Reported risk factors for OBPI include shoulder dystocia, macrosomia (defined as birth weight greater than 4500 g) [8-11]), instrument-assisted delivery, and downward traction of the fetal head [3, 12, 13]. Shoulder dystocia is the most prevalent risk factor in our patients [14]; almost all the children in our study had documented shoulder dystocia [14]. Shoulder dystocia is, therefore, closely associated with the most severe cases of permanent obstetric brachial plexus injuries [8, 9, 11]. However, permanent injury is not exclusive to large infants; 80% of the OBPI patients in our published study were not macrosomic and 43% (104/241) weighed less than 4000 g at birth [14]. OBPI that occur during breech deliveries may have a different mechanism of onset, and are more likely to be bilateral. Avulsions of the upper roots are more likely during breech than during vertex delivery [15, 16]. OBPI may also occur, although very rarely, during cesarean sections [17].

Successful Outcome of Triangle Tilt as Revision Surgery in a Pediatric Obstetric Brachial Plexus Patient with Multiple Previous Operations

Introduction. Obstetric brachial plexus injury (OBPI) occurs during the process of labor and childbirth. OBPI has been reported to be associated with shoulder dystocia, macrosomia, and breech delivery. Its occurrence in uncomplicated delivery is possible as well. Case Presentation. The patient in the present report is a 6.5-year-old girl, who suffered a severe brachial plexus injury at birth and had many reconstructive surgical procedures at an outside brachial plexus center before presenting to us. Discussion. The traditional surgical treatments by other surgical groups were unsuccessful and therefore the patient came to our clinic for further treatment. She had triangle tilt surgery with us, as a salvage procedure. Conclusion. The OBPI patient in this study clearly showed noticeable clinical and functional improvements after triangle tilt surgical management. The posture of the arm at rest was greatly improved to a more normal position, and hand to mouth movement was improved as well. Triangle tilt surgery should be conducted as a first choice treatment for medial rotation contracture of the shoulder in OBPI patients.

Finger movement at birth in brachial plexus birth palsy

AIM To investigate whether the finger movement at birth is a better predictor of the brachial plexus birth injury. METHODS We conducted a retrospective study reviewing pre-surgical records of 87 patients with residual obstetric brachial plexus palsy in study 1. Posterior subluxation of the humeral head (PHHA), and glenoid retroversion were measured from computed tomography or Magnetic resonance imaging, and correlated with the finger movement at birth. The study 2 consisted of 141 obstetric brachial plexus injury patients, who underwent primary surgeries and/or secondary surgery at the Texas Nerve and Paralysis Institute. Information regarding finger movement was obtained from the patients parent or guardian during the initial evaluation. RESULTS Among 87 patients, 9 (10.3%) patients who lacked finger movement at birth had a PHHA > 40%, and glenoid retroversion < -12°, whereas only 1 patient (1.1%) with finger movement had a PHHA > 40%, and retroversion < -8° in study 1. The improvement in glenohumeral deformity (PHHA, 31.8% ± 14.3%; and glenoid retroversion 22.0° ± 15.0°) was significantly higher in patients, who have not had any primary surgeries and had finger movement at birth (group 1), when compared to those patients, who had primary surgeries (nerve and muscle surgeries), and lacked finger movement at birth (group 2), (PHHA 10.7% ± 15.8%; Version -8.0° ± 8.4°, P = 0.005 and P = 0.030, respectively) in study 2. No finger movement at birth was observed in 55% of the patients in this study group. CONCLUSION Posterior subluxation and glenoid retroversion measurements indicated significantly severe shoulder deformities in children with finger movement at birth, in comparison with those lacked finger movement. However, the improvement after triangle tilt surgery was higher in patients who had finger movement at birth.

Protective Effect of Type I Collagen Antisense Oligonucleotides on Bleomycin Induced Pulmonary Fibrosis

Background: Pulmonary fibrosis is a chronic and usually untreatable fatal lung disease. It can result from many endogenous or exogenous causes, such as infection, chronic inflammatory diseases, environmental toxins, chemical poisoning, radiation and chemotherapy. The accumulation of collagen, largely type I collagen rich extracellular matrix (ECM) is the hallmark of lung fibrosis. Current therapies for pulmonary fibrosis utilizing corticosteroids and immunosupressants have demonstrated only marginal effectiveness. Methods: In the present study, we tested the efficacy of the mouse type 1 collagen antisense oligodeoxynucleotides (AS61-ODN, a 20 mer) in bleomycin induced pulmonary fibrosis in mice. Bleomycin was instilled transtracheally by direct tracheal cut down in mice, and oligonucleotides (ODN) were injected through the tail vein. Hematoxylin and eosin (H & E) and Massons trichrome staining were done to determine the cellular architecture of the lungs after bleomycin and oligonucleotide treatment. Type I procollagen gene COL1A1 expression was determined by Northern blot analysis. Type I collagen protein expression was determined by Western blot analysis and immunofluorescence. Results: There was much less disruption of the lung architecture as indicated by significant decrease in the Ashcroft score, when mice were injected with AS61-ODN following bleomycin instillation. AS61-ODN significantly reduced the mRNA and protein expression of type 1 collagen by 45.2 % (p < 0.015) and 35.0 % (p < 0.004) respectively 21 days after treatment in bleomycin induced fibrotic lung tissue. Immunofluorescence of bleomycin induced mouse lung tissue treated with AS61-ODN showed a specific reduction in collagen expression and fibrosis. Conclusion: Human type I collagen antisense oligodeoxynucleotides (AS60- ODN, a 20 mer), which is 99 percent homologous with mouse AS61-ODN, might be useful as a potential therapeutic agent to treat patients with pulmonary fibrosis.