Dosimetric feasibility of hippocampal avoidance whole brain radiotherapy with an MRI-guided linear accelerator.

Purpose/objective(s): Whole brain radiotherapy with hippocampal avoidance (HA-WBRT) is a technique utilized to treat metastatic brain disease while preserving memory and neurocognitive function. We hypothesized that the treatment planning and delivery of HA-WBRT plans is feasible with an MRI-guided linear accelerator (linac) and compared plan results with clinical non-MRI-guided C-Arm linac plans.

Materials/methods: Twelve HA-WBRT patients treated on a non-MRI-guided C-Arm linac were selected for retrospective analysis.

MR-guided stereotactic body radiation therapy for intracardiac and pericardial metastases.

Aims: To assess the safety and efficacy of MR-guided stereotactic body radiation therapy (MRgSBRT) for cardiac metastases.

Materials/methods: This single institution retrospective analysis evaluated our experience with MRgSBRT for cardiac metastases. Response rate was compared between pre-RT and post-RT imaging.

Impact of recurrent laryngeal nerve lesion on oropharyngeal muscle activity and sensorimotor integration in an infant pig model.

The successful performance of a swallow requires dynamic integration between a wide range of sensory inputs and muscle activities to produce the coordinated kinematics of oropharyngeal structures. Damage to the recurrent laryngeal nerve (RLN) produces dysphagia in infants, with food or liquid entering the airway despite this nerve having minimal direct sensory or motor connections to the act of swallowing, apart from vocal fold closure. Previous results have demonstrated that a complete RLN lesion disrupts both performance and kinematics before initiation of the pharyngeal swallow in infants.

Maturation of the Coordination Between Respiration and Deglutition with and Without Recurrent Laryngeal Nerve Lesion in an Animal Model.

The timing of the occurrence of a swallow in a respiratory cycle is critical for safe swallowing, and changes with infant development. Infants with damage to the recurrent laryngeal nerve, which receives sensory information from the larynx and supplies the intrinsic muscles of the larynx, experience a significant incidence of dysphagia. Using our validated infant pig model, we determined the interaction between this nerve damage and the coordination between respiration and swallowing during postnatal development.

Bone Graft Substitute Provides Metaphyseal Fixation for a Stemless Humeral Implant.

Stemless humeral fixation has become an alternative to traditional total shoulder arthroplasty, but metaphyseal fixation may be compromised by the quality of the trabecular bone that diminishes with age and disease, and augmentation of the fixation may be desirable. The authors hypothesized that a bone graft substitute (BGS) could achieve initial fixation comparable to polymethylmethacrylate (PMMA) bone cement. Fifteen fresh-frozen human male humerii were randomly implanted using a stemless humeral prosthesis, and metaphyseal fixation was augmented with either high-viscosity PMMA bone cement (PMMA group) or a magnesium-based injectable BGS (OsteoCrete; Bone Solutions Inc, Dallas, Texas) (OC group).

Clinically relevant mechanical testing of hernia graft constructs.

Background: To understand the mechanical behavior of grafts in the context of hernia repair, there is a need to develop and adopt methods for mechanical testing of grafts in a clinically-relevant manner with clinically-relevant outcomes.

Materials And Methods: Ball-burst and planar-biaxial methods were used to test three commercially-available hernia grafts (DermaMatrix, Biodesign, VitaMesh Blue). Both load-to-failure and cyclic fatigue tests were performed (n=6-11/group/test).

Fiber-reinforced dermis graft for ventral hernia repair.

Ventral hernia repair (VHR) continues to be a challenge for surgeons. Poor long-term durability of the commonly-used human acellular dermal matrix (HADM) grafts often results in VHR failure and reherniation. We hypothesized that fiber-reinforcement will improve the mechanical properties of HADM grafts and maintain these properties after enzymatic degradation.

Postnatal dexamethasone treatment and retinopathy of prematurity in very-low-birth-weight neonates.

Whether postnatal dexamethasone treatment for bronchopulmonary dysplasia (BPD) increases the risk of retinopathy of prematurity (ROP) in very-low-birth-weight (VLBW) neonates is uncertain. We performed a retrospective cohort study to determine the association between dexamethasone administered postnatally and the development of ROP in VLBW (< or = 1,250 g birth weight, < or = 32 weeks' gestational age at birth) neonates. The incidence of severe ROP (stage 2 or higher) was 26% among 72 infants who received no dexamethasone postnatally, 61% among 23 infants who received a low cumulative dexamethasone dose (< or = 1.

A serologic survey of selected viral and bacterial diseases of European wild hogs, Great Smoky Mountains National Park, USA.

Blood samples were collected from 108 wild hogs (Sus scrofa) from the Great Smoky Mountains National Park (GSMNP), USA, February to July 1990. We found no antibodies for swine brucellosis, pseudorabies, bovine virus diarrhea virus or porcine rotavirus infection. Antibody titers to porcine parvovirus were found in 15 (14%) samples and antibody to one or more leptospiral serovars was found in 48 (44%) samples.

Interactions between murine alveolar macrophages and Mycoplasma pulmonis in vitro.

In comparison to syngeneic fibroblasts, alveolar macrophages collected from Fischer 344 rats demonstrated a significant ability to decrease the growth rate of cell-associated Mycoplasma pulmonis, even in the absence of specific actimycoplasmal antibodies. However, when exposed to thallium acetate (a cytotoxic heavy metal), macrophages supported growth of mycoplasmas almost as well as did untreated fibroblasts. This suggests an active antimycoplasmal process operative in untreated macrophages.