Anne Argenta

Vacuum-assisted closure: state of basic research and physiologic foundation.

Summary: A tremendous amount of research has been conducted in recent years investigating the mechanisms of action by which the application of subatmospheric pressure to wounds increases the rate of healing. Similarly, numerous studies have also been conducted examining the physiologic response of wounds to the applied subatmospheric pressure. However, many more need to be conducted. A series of basic studies examining the use of subatmospheric pressure to treat wounds is presented, including the original studies upon which the vacuum-assisted closure device was based (on blood flow, granulation tissue formation, bacterial clearance, and survival of random-pattern pedicle flaps). Subsequent studies analyzing removed fluids, envenomation/extravasation, burns, grafts, and in vitro tissue culture studies are also reviewed. Two broad mechanisms of action are proposed: removal of fluid and mechanical deformation. Fluid removal both decreases edema–-thus decreasing interstitial pressure and shortening distances of diffusion–-and removes soluble factors that may affect the healing process (both positively and negatively). The relationship of mechanical deformation to increased growth is well known to plastic surgeons, as it is the basis of tissue expansion. While much has been done, a great deal more needs to be done to elucidate the mechanisms of action responsible for the dramatic response seen clinically.

Outcome analysis of helmet therapy for positional plagiocephaly using a three-dimensional surface scanning laser.

Introduction: A dramatic rise in positional plagiocephaly has been noted over the last decade. Methods for treating and following outcomes are varied. We present our results from a passive soft helmet molding therapy using a surface scanning laser to provide objective outcomes. Methods: One hundred seventy-five infants with positional plagiocephaly were treated at our institution over a 6-month period. The helmets used were soft foam helmets modified to fit each patient. Results were measured using a three-dimensional surface scanning laser and objective measurements of asymmetry. Compliance was also documented. Results: The scanning laser allowed for objective measurements of symmetry over time and was useful in following outcomes. Improvement in head shape was noted after about 4 months of therapy. Patients who were more compliant with therapy achieved better results. Conclusion: Use of the three-dimensional scanning laser and objective scoring system shows significant improvement in patients who were compliant with helmet therapy.

Stereological quantification of GAD-67–immunoreactive neurons and boutons in the hippocampus of middle-aged and old Fischer 344 × Brown Norway rats

The aging process in rodents is associated with learning and memory impairments that are correlated with changes in multiple neurotransmitter systems in the hippocampus. For example, the γ‐aminobutyric acid (GABA)ergic system is compromised in old compared with young rats (Shetty and Turner [ 1998 ] J. Comp. Neurol. 394:252–269; Vela et al. [ 2003 ] J. Neurochem. 85:368–377; Potier et al. [ 1992 ] Neuroscience 48:793–806; Potier et al. [ 1994 ] Brain Res. 661:181–188). The present study investigated the important issue of whether there is a decline of the GABAergic inhibitory system between middle and old age. Five middle‐aged (15–17 months) and five old (25–29 months) Fischer 344 × Brown Norway male rats were perfused, and coronal sections through the dorsal hippocampus were immunoreacted with antibodies either to NeuN, a neuronal marker, or to the 67‐kDa isoform of glutamic acid decarboxylase (GAD), the rate‐limiting enzyme for GABA synthesis. Using the optical dissector technique, NeuN‐immunoreactive (IR) cells, GAD‐IR cells, and GAD‐IR boutons were quantified stereologically in the dentate gyrus, CA3, and CA1. The resulting GAD‐IR cell and GAD‐IR bouton densities then were normalized to NeuN‐IR cell density to exclude the possible confound of tissue shrinkage. The results revealed a significant decline in GAD‐IR cells between middle and old age in CA1 but not in dentate gyrus or CA3. Interestingly, GAD‐IR boutons did not show a decline in CA1, CA3, or dentate gyrus between middle and old age. It is possible that loss of CA1 inhibitory interneurons in the dorsal hippocampus contributes to the learning and memory impairments reported in old rats. J. Comp. Neurol. 478:282–291, 2004.

Maintenance of inhibitory interneurons and boutons in sensorimotor cortex between middle and old age in Fischer 344 X Brown Norway rats

Ultrastructurally identified inhibitory synapses in layer II of rat sensorimotor cortex decline between middle and old age [Poe, B.H., Linville, C., Brunso-Bechtold, J., 2001. Age-related decline of presumptive inhibitory synapses in the sensorimotor cortex as revealed by the physical disector. J. Comp. Neurol. 439, 65-72]. The current study investigated whether a loss or shrinkage of gamma-aminobutyric acid (GABA)ergic interneurons contribute to that decline. Coronal sections from middle-aged (15-17 months) and old (25-29 months) Fischer 344 X Brown Norway male rats were immunoreacted with antibodies to the GABA synthesizing enzyme glutamic acid decarboxylase (GAD); the calcium-binding protein parvalbumin (PV), or the neuronal marker NeuN. The number of GAD-immunoreactive (IR), PV-IR, and NeuN-IR cells were determined stereologically using the optical disector technique and the cross-sectional areas of GAD-IR cells were measured in layers II/III, IV, V and VI of sensorimotor cortex. Neither the number of GAD-IR or NeuN-IR cells, nor the size of GAD-IR cells, declined significantly between middle and old age. A modest decline in the PV-IR subset of inhibitory interneurons was observed, predominantly due to changes in layers V and VI. Stereological analysis of layer II/III GAD-IR boutons revealed a stability of immunocytochemically identified inhibitory terminals. Taken together, these results indicate a general maintenance of overall GABAergic neurons in sensorimotor cortex between middle and old age and the loss of ultrastructurally identified inhibitory synapses may be due to the decline of a subset of GABAergic terminals.

Magnetic resonance imaging as a predictor of submucous cleft palate severity and guide for surgical intervention.

BackgroundDiagnosis of submucous cleft palate (SMCP) is frequently delayed, adversely affecting speech outcomes. Previous studies show that MRI reliably identifies structural abnormalities in velopharyngeal musculature. This information has potential to assist with diagnosis and treatment decisions. AimsThe objectives of this study were to (1) develop a clinician-friendly MRI grading scale of SMCP anatomy, (2) identify correlations between radiographic cleft severity and clinical severity using Pittsburgh Weighted Speech Scores (PWSS), and (3) determine if MRI is a predictor of surgical efficacy in improving PWSS. DesignThirty patients presenting to our Cleft Palate-Craniofacial Clinic for evaluation of velopharyngeal insufficiency (VPI) and suspected SMCP were reviewed. VPI severity was clinically graded using PWSS. All patients underwent MRI to grade palatal abnormalities, using a novel MRI grading scale. PWSS and cleft severity on MRI were compared. A subgroup of patients (n = 19) underwent palatoplasty. Preoperative and postoperative PWSS were compared. Degree of PWSS improvement was then correlated with the preoperative MRI grade. ResultsTwenty-nine out of 30 MRIs demonstrated abnormal palate anatomy. Of the 30 patients evaluated, 5 clinically improved with speech therapy alone. In this subgroup, MRI severity did not correlate with PWSS (P = 0.06–0.6). Nineteen patients underwent palatoplasty. Of these, 14 demonstrated improved postoperative PWSS. There were no significant correlations between severity of cleft on imaging and preoperative PWSS or score improvement (P = 0.056–0.65). ConclusionWhile MRI accurately identifies structural abnormalities of the soft palate, these abnormalities do not reliably correspond to clinical severity. Clinical examination including speech scores and dynamic speech testing, rather than static MRI, should guide treatment decisions and surgical indications.

Abstract 176: USE OF ADIPOSE DERIVED STEM CELLS FOR THE IMPROVEMENT OF BURN WOUND HEALING

Methods: Twenty athymic nude mice were subjected to nonfatal full thickness burns, using a 1cm diameter brass stamp heated to 70°C and applied to the paraspinal region for 10 seconds. On post-burn day 1, animals were randomized to receive a one time sub-eschar injection of either ADSCs suspended in sterile PBS (6.8x106 cells per injection; treatment group) or sterile PBS only (control group). Wounds were photographed three times weekly to measure the rate of wound healing. Mice from each group were sacri ced on post burn days 4,7,14,21. Wound tissues were evaluated histologically with H +E, Mason Trichrome, Picroserius, and CD31 staining to evaluate wound healing. Molecular studies measured markers of in ammation, adipogenesis and collagen formation.