Analysis of Risk Factors for Tracheal Stenosis Managed during COVID-19 Pandemic: A Retrospective, Case-Control Study from Two European Referral Centre.

Introduction: Benign subglottic/tracheal stenosis (SG/TS) is a life-threatening condition commonly caused by prolonged endotracheal intubation or tracheostomy. Invasive mechanical ventilation was frequently used to manage severe COVID-19, resulting in an increased number of patients with various degrees of residual stenosis following respiratory weaning. The aim of this study was to compare demographics, radiological characteristics, and surgical outcomes between COVID-19 and non-COVID patients treated for tracheal stenosis and investigate the potential differences between the groups.

Swine intestinal segment perfusion model for the evaluation of nutrients bioaccessibility.

Nutrition science requires more science-based evidences for the development of effective functional diets. To reduce animals for experimental purposes innovative reliable and informative models, simulating the complex intestinal physiology, are needed. The aim of this study was to develop a swine duodenum segment perfusion model for the evaluation of nutrient bioaccessibility and functionality across time.

7-T MRI tracking of mesenchymal stromal cells after lung injection in a rat model.

Background: Mesenchymal stromal cells (MSCs) are able to migrate and engraft at sites of inflammation, injuries, and tumours, but little is known about their fate after local injection. The purpose of this study is to perform MSC tracking, combining in vivo 7-T magnetic resonance imaging (MRI) and histological assessment, following lung injection in a rat model.

Methods: Five lungs were injected with ferumoxide-labelled MSCs and five with perfluorocarbon-labelled MSCs and underwent 7-T MRI.

A Novel Hybrid Silk Fibroin/Polyurethane Arteriovenous Graft for Hemodialysis: Proof-of-Concept Animal Study in an Ovine Model.

To solve the problem of vascular access failure, a novel semi-degradable hybrid vascular graft, manufactured by electrospinning using silk fibroin and polyurethane (Silkothane), has been previously developed and characterized in vitro. This proof-of-concept animal study aims at evaluating the performances of Silkothane grafts in a sheep model of arteriovenous shunt, in terms of patency and short-term remodeling. Nine Silkothane grafts are implanted between the common carotid artery and the external jugular vein of nine sheep, examined by palpation three times per week, by echo-color Doppler every two weeks, and euthanized at 30, 60, and 90 days (N = 3 per group).

Diffusion Tensor Magnetic Resonance Tractography of the Sheep Brain: An Atlas of the Ovine White Matter Fiber Bundles.

Diffusion Tensor Magnetic Resonance Imaging (DTI) allows to decode the mobility of water molecules in cerebral tissue, which is highly directional along myelinated fibers. By integrating the direction of highest water diffusion through the tissue, DTI Tractography enables a non-invasive dissection of brain fiber bundles. As such, this technique is a unique probe for characterization of white matter architecture.

Simple and Quick Method to Obtain a Decellularized, Functional Liver Bioscaffold.

The development of new approaches for organ transplantation has become crucial in the last years. In particular, organ engineering, involving the preparation of acellular matrices that provide a natural habitat for reseeding with an appropriate population of cells, is an attractive although technically demanding approach. We here describe a method that allows for the derivation of functional in vitro hepatic organoids and that does not require a previous selection of all the parenchymal hepatocytes and non-parenchymal cells, namely, Kupffer cells, liver endothelial cells, and hepatic stellate cells.

High Penetration of Paclitaxel in Abdominal Wall of Rabbits after Hyperthermic Intraperitoneal Administration of Nab-Paclitaxel Compared to Standard Paclitaxel Formulation.

Purpose: Paclitaxel (PTX) is currently used in combination with cisplatin for Hyperthermic Intraperitoneal Chemotherapy (HIPEC) for the treatment of peritoneal carcinomatosis. Albumin-bound PTX is a promising new drug for HIPEC because of its easy solubility in aqueous perfusion medium and possibly because of the tendency of albumin to cross physiological barriers and accumulate in tumor tissue.

Methods: We tested the feasibility of using nab-paclitaxel in rabbits treated by HIPEC for 60 min compared with the classical formulation at an equivalent PTX dose.

Stem cell transplantation effectively occludes bronchopleural fistula in an animal model.

Background: Bronchopleural fistula after lung resection still represents a challenging life-threatening complication for thoracic surgeons. Considering its extremely high mortality rate, an effective treatment is urgently required. Our project investigated the hypothesis of experimental bronchopleural fistula closure by bronchoscopic injection of autologous bone marrow-derived mesenchymal stem cells into the cavity of the fistula, evaluating its feasibility and safety in a large animal model.

Finite element analysis of the mechanical behavior of preterm lamb tracheal bifurcation during total liquid ventilation.

Knowledge of the mechanical behavior of immature airways is crucial to understand the effects exerted by ventilation treatments, namely by Total Liquid Ventilation (TLV). A computational approach was adopted to investigate preterm airways in the range of pressure applied during TLV. A 3D finite-element model of the tracheal bifurcation was developed.

Persistent right aortic arch and associated axial skeletal malformations in cats.

Persistent right aortic arch (PRAA) in cats is an uncommon vascular anomaly with clinical signs referable to oesophageal obstruction. To our knowledge no reports of axial skeletal malformations concomitant to PRAA have been reported in cats. The aim of this study is to depict a new clinical feature in cats affected by PRAA.

Experimental and computational biomechanical characterisation of the tracheo-bronchial tree of the bottlenose dolphin (Tursiops truncatus) during diving.

Dolphins have adapted their anatomic structures to survive in the water environment and so far, the behaviour of their respiratory system during diving has not been fully understood, since they being protected species cannot be subjected to invasive analysis. Aim of this work is to model the tracheo-bronchial tree of the bottlenose dolphin Tursiops truncatus to study its behaviour during diving by coupling experimental in vitro mechanical characterisation of airways tissues to finite element computational analyses. Furthermore, a comparison was performed between the mechanical behaviour of tracheo-bronchial trees of dolphins and that of the goat, a terrestrial mammal, whose conformation of the upper airways is similar to that of the human, to determine how different structures respond to pressure in a controlled experimental set-up.

Morphologic features of biocompatibility and neoangiogenesis onto a biodegradable tracheal prosthesis in an animal model.

We evaluated a newly designed bioresorbable polymer (Degrapol) tracheal prosthesis in an in-vivo angiogenesis-inducing animal model focusing on the specific tissue reaction, the neo-angiogenesis and also the eventual cathepsin B role during the polymer degradation. Fifteen rabbits were divided into three groups (2, 6 and 8 weeks) and our tube-shaped porous prosthesis was implanted using the common carotid artery and the internal jugular vein as vascular pedicle. Optical and electron microscopy, immunohistochemistry and immunocytochemistry were performed at the end of each period, showing cells and fibrils, in direct contact with the Degrapol scaffold, strongly increased with time.

Chylothorax associated with tricuspid dysplasia and atrial septal defect in a bullmastiff.

Transudate pleural effusion associated with tricuspid dysplasia and ostium secundum-type atrial septal defect was diagnosed in a 14-month-old bullmastiff. Following administration of furosemide and an angiotensin-converting enzyme (ACE) inhibitor, the dog remained free of pleural effusion for 10 months, until he showed severe dyspnea due to chylothorax. Medical therapy was unsuccessful to avoid recurrence of life-threatening pleural chylous effusion.

Do cardiac stabilizers really stabilize? Experimental quantitative analysis of mechanical stabilization.

In order to assess the three-dimensional movement of the coronary arteries both during normal cardiac activity and after mechanical stabilization, a polypropylene black marker was placed in 10 pigs on the middle portion of the three main coronary branches. Marker motion was recorded for 10 s using two TV-digital cameras and was estimated with a precision of 50 microm. After stabilization with three different mechanical stabilizers (Medtronic, Genzyme, CTS-Guidant), a remnant coronary artery excursion of about 1.

Prefabricated tracheal prosthesis with partial biodegradable materials: a surgical and tissue engineering evaluation in vivo.

Large and circumferential tracheal defects remain at this time an unsolved problem for reconstructive surgery. Many types of prosthetic and tissue grafts have been used but with limited comfortable results. Major complications are anastomotic dehiscence, graft ischemia and stenosis due to the poor vascularization of the prosthetic complex.

Expression of c-kit proto-oncogene in canine mastocytoma: a kinetic study using real-time polymerase chain reaction.

KIT receptor, the c-kit gene product, is thought to play a major role in canine mastocytoma, one of the most common neoplastic diseases in dogs. In the present study, the expression of c-kit proto-oncogene in blood and in tumor biopsies from 41 dogs with histologically confirmed mastocytoma at different grades of cellular differentiation and 5 negative control dogs was investigated using real-time (quantitative) reverse transcription-polymerase chain reaction (RRT-PCR). The animals were followed up for over 1 year after surgery in order to characterize the kinetics of c-kit expression in blood.

Structure and biomechanical properties of the trachea of the striped dolphin Stenella coeruleoalba: evidence for evolutionary adaptations to diving.

This study analyzes the structure and mechanical properties of the trachea of the striped dolphin Stenella coeruleoalba, one of the most common cetacean species. The cetacean trachea is made up of closed or semiclosed cartilaginous rings without a paries membranaceus. Our results indicate that the inner lining of the trachea contains erectile tissue in which several venous lacunae permeate the mucosa.

The effect of maternal hypothermic cardiopulmonary bypass on fetal lamb temperature, hemodynamics, oxygenation, and acid-base balance.

Objective: To evaluate fetal-maternal temperature relationship and fetal cardiovascular and metabolic response during maternal hypothermic cardiopulmonary bypass in pregnant ewes.

Methods: Cardiopulmonary bypass was instituted in 9 pregnant ewes, reaching 2 different levels of maternal hypothermia: 24 degrees C to 20 degrees C (deep hypothermia) in group A (5 cases) and less than 20 degrees C (very deep hypothermia) in group B (4 cases). Hypothermic levels were maintained for 20 minutes, then the rewarming phase was started.

Effects of abdominal distension on breathing pattern and respiratory mechanics in rabbits.

The effects of acute abdominal distension (AD) on the electromechanical efficiency (Eff) of the inspiratory muscles were investigated in anesthetized rabbits by recording the electrical activity (A), pressure (P) exerted by the diaphragm (di) and parasternal intercostal muscles (ic), and lung volume changes when an abdominal balloon was inflated to various degrees. Eff,ic increased with increasing AD both in supine and upright postures. In upright rabbits Eff,di increased for intermediate but decreased at higher levels of AD, whilst it decreased at all levels of AD in supine rabbits.