Publications by authors named "Louis Argenta"

Our previous studies on the treatment of spinal cord injuries with Mechanical Tissue Resuscitation (MTR) in rats have demonstrated that it can significantly improve the locomotor recovery and Basso Beattie Bresnahan scores. MTR treatment also reduced fluid accumulations by T2-imaging and improved the mean neural fiber number and fiber length in injured sites by fiber tractography. Myelin volume was also significantly preserved by MTR treatment.

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Objective: The previous laboratory and clinical experience of the authors had demonstrated that application of controlled subatmospheric pressure directly to injured soft tissue can result in increased survival of compromised tissues. Mechanical tissue resuscitation (MTR) is a new concept evolving from these discoveries. The authors' recent studies have demonstrated that traumatic brain injury tissue can also be salvaged.

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Aging in humans and animals is associated with gradual and variable changes in some cognitive functions, but what causes them and explains individual variations remains unclear. Hydration decreases with aging but whether dehydration contributes to cognitive dysfunction is not known. The brain hydration of aging mice was determined by colloidosmotic-pressure titration.

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The interstitial myocardial matrix is a complex and dynamic structure that adapts to local fluctuations in pressure and actively contributes to the heart's fluid exchange and hydration. However, classical physiologic models tend to treat it as a passive conduit for water and solute, perhaps because local interstitial regulatory mechanisms are not easily accessible to experiment in vivo. Here, we examined the interstitial contribution to the fluid-driving pressure ex vivo.

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Background: Traumatic spinal cord injury (SCI) is a major worldwide cause of mortality and disability with limited treatment options. Previous research applying controlled negative pressure to traumatic brain injury in rat and swine models resulted in smaller injuries and more rapid recovery.

Objective: To examine the effects of the application of a controlled vacuum (mechanical tissue resuscitation [MTR]) to SCI in a rat model under several magnitudes of vacuum.

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Poly(glycerol sebacate) (PGS)/nanohydroxyapatite (nHA) composites were assessed to develop new materials for closure via tissue transport for nonhealing defects (e.g., cleft palate and large skin wounds).

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Background And Aim: Myocardial ischemia-reperfusion injury is known to trigger an inflammatory response involving edema, apoptosis, and neutrophil activation/accumulation. Recently, mechanical tissue resuscitation (MTR) was described as a potent cardioprotective strategy for reduction of myocardial ischemia-reperfusion injury. Here, we further describe the protective actions of MTR and begin to define its therapeutic window.

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Le Fort III osteotomy is commonly used in the surgical correction of midface hypoplasia, specifically in patients with syndromic craniosynostosis. These osteotomies can be associated with significant complications, which are often the result of incomplete or inaccurate osteotomies. Brainlab, a technology first developed for neurosurgery, has been applied to numerous surgical subspecialties.

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Purpose: The aim of this study was to demonstrate that multi-wall carbon nanotubes can be functionalised with antibodies to group A streptoccocus (GAS) for targeted photothermal ablation of planktonic and biofilm residing bacteria.

Materials And Methods: Antibodies for GAS were covalently attached to carboxylated multi-wall carbon nanotubes and incubated with either planktonic or biofilm GAS. Bacterium was then exposed to 1.

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Conventional collagen-based heart valves eventually fail because of insufficient replacement of graft material by host tissue. In this study, type I collagen was blended with silk fibroin and the synthetic elastic polymer poly (glycerol-sebacate) (PGS) in varying proportions to create multifunctional electrospun nanofibrous materials tailored for use as endovascular scaffolds such as heart valve replacement. Depending on the blended material the elastic moduli ranged from 2.

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Purpose Of Review: To present the current surgical options for minimally invasive surgery for treatment of craniosynostosis.

Recent Findings: Minimally invasive procedures are well tolerated treatment options for patients with craniosynostosis. Suturectomy and helmet therapy is a treatment option for scaphocephaly with minimal blood loss and length of hospital stay.

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Background: Traumatic brain injuries (TBIs) continue to be a devastating problem with limited treatment options. Previous research applying controlled vacuum to TBI in a rat model resulted in smaller injuries and more rapid recovery.

Objective: To examine the effects of the application of a controlled vacuum (mechanical tissue resuscitation) to TBI in a large-animal model.

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Thermal injury disrupts fluid homeostasis and hydration, affecting hemodynamics and local interstitial fluid-driving forces, leading rapidly to edema. This study explores local mechanisms in vivo, after deep partial-thickness burns in the dermal matrix. Heat-damaged skin was obtained from pig corpses, byproducts of unrelated burn treatment protocols approved by the Institutional Animal-Care-and-Use Committee.

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Background And Aim: Reperfusion injury is a complex inflammatory response involving numerous mechanisms and pathways. Mechanical tissue resuscitation is a newly described therapeutic strategy that reduces reperfusion injury. This study further investigates potential mechanisms for the protective effects of mechanical tissue resuscitation while utilizing a bio-absorbable matrix.

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Single nanofibers with chemical and functional properties consistent with artery extracellular matrix nanofibers were produced by electrospinning. Using weight ratios to mimic artery extracellular matrix, five materials were tested: (1) Collagen type I, (2) Collagen type I + Collagen type III, (3) Collagen type I + poly (diol citrate), (4) Collagen type I + Collagen type III + poly (diol citrate), and (5) Collagen type I + poly (diol citrate) + Decorin + Aggrecan. Fiber sizes for all materials ranged from 50 nm to 600 nm and random fiber mats had pore sizes from 21 to 40 = m(2) and porosities of 72-84%.

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In the interstitial matrix, collagen unfolding at physiologic temperatures is thought to facilitate interactions with enzymes and scaffold molecules during inflammation, tissue remodeling, and wound healing. We tested the hypothesis that it also plays a role in modulating flows and matrix hydration potential. After progressively unfolding dermal collagen in situ, we measured the hydration parameters by osmotic stress techniques and modeled them as linear functions of unfolded collagen, quantified by differential scanning calorimetry after timed heat treatment.

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The aim in this study was to describe the safety and efficacy of vacuum-assisted closure (VAC) in patients with complex cranial wounds with extensive scalp, bone, and dural defects who were not candidates for immediate free tissue transfer. Five patients (4 men and 1 woman) ages 24-73 years with complex cranial wounds were treated with VAC at Wake Forest Baptist Medical Center. Etiologies included trauma, squamous cell carcinoma, and malignant meningioma.

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Severity of the Harlequin deformity seen in unicoronal synostosis may be augmented when frontoparietal suture synostosis has an associated fusion of the frontosphenoidal suture or in cases of isolated frontosphenoidal synostosis. The purpose of the current study is to characterize various suture fusion patterns along the coronal ring using a modified orbital index (MOI), orbital angle (OA), and endocranial base (EB) angle.This study is a retrospective single institution cohort study.

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Velopharyngeal insufficiency (VPI) occurs in more than 20% of patients with a cleft palate after primary palatoplasty. Surgical treatment focuses on pharyngoplasty to narrow the nasopharyngeal space and to decrease the distance needed for palatal closure. Persistent VPI after pharyngoplasty affects more than 20% of patients.

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Background: Traumatic brain injuries remain a treatment enigma with devastating late results. As terminally differentiated tissue, the brain retains little capacity to regenerate, making early attempts to preserve brain cells after brain injury essential.

Objective: To resuscitate damaged tissue by modulating edema, soluble cytokines, and metabolic products in the "halo" of damaged tissue around the area of central injury that progressively becomes compromised.

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Lymphatic malformation (LM) is a benign cystic entity resulting from aberrant lymphatic drainage. Often evident at birth, most LMs have declared themselves by 2 years of age. They can be concerning when they occur near vital structures such as the airway or orbit.

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Treatment of wounds using negative pressure wound therapy (NPWT) uses a nondegradable polyvinyl alcohol (PVA) foam in the application of negative pressures typically for 1-3 days. The purpose of this study was to construct and test biodegradable poly(ε-caprolactone) (PCL) foam as a substitute for the PVA foam. Such a foam would be left within the wound until healing was achieved and form a biodegradable matrix into which tissue would grow.

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Background:   The anesthetic risks and outcomes of the first 100 consecutive spring-assisted surgeries (SAS) for cranial expansion from a single institution are reported. The effect of number of procedures was also tested on hematocrit postoperative day 1 (POD1), anesthesia time, and surgery time of the first procedure.

Methods:   The records of 100 consecutive patients undergoing SAS were reviewed.

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Neonates rely on the nasal airway for their source of air; thus, any compromise in the ability to inhale will dramatically alter their ability to breathe. Congenital nasal pyriform aperture stenosis is a rare yet serious form of airway obstruction due to overgrowth of the maxilla at the medial nasal process. Infants typically present with difficulty feeding and obvious difficulty breathing.

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The local pathogenesis of interstitial edema in burns is incompletely understood. This ex vivo study investigates the forces mediating water-transfer in and out of heat-denatured interstitial matrix. Experimentally, full-thickness dermal samples are heated progressively to disrupt glycosaminoglycans, kill cells, and denature collagen under conditions that prevent water loss/gain; subsequently, a battery of complementary techniques including among others, high-resolution magnetic resonance imaging, equilibrium vapor pressure and osmotic stress are used to compare water-potential parameters of nonheated and heated dermis.

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