Chitosan 3D scaffolds with resolvin D1 for vertebral arthrodesis: a pilot study.

Purpose: Over the last years, the number of vertebral arthrodesis has been steadily increasing. The use of iliac crest bone autograft remains the "gold standard" for bone graft substitute in these procedures. However, this solution has some side effects, such as the problem of donor site morbidity indicating that there is a real need for adequate alternatives.

The inflammasome in biomaterial-driven immunomodulation.

Inflammasomes are intracellular structures formed upon the assembly of several proteins that have a considerable size and are very important in innate immune responses being key players in host defense. They are assembled after the perception of pathogens or danger signals. The activation of the inflammasome pathway induces the production of high levels of the pro-inflammatory cytokines Interleukin (IL)-1β and IL-18 through the caspase activation.

Immunomodulatory biomaterial-based wound dressings advance the healing of chronic wounds via regulating macrophage behavior.

Successful wound healing is a process that has three overlying phases: inflammatory, proliferative and remodeling. Chronic wounds are characterized by a perpetuated inflammation that inhibits the proliferative and remodeling phases and impairs the wound healing. Macrophages are key modulators of the wound healing process.

High-intensity infrasound effects on glucose metabolism in rats.

Recent focus has been given on the effects of high-intensity infrasound (HII) exposure, and whether it induces changes in pancreatic morphology and glucose metabolism is still unknown. As such, we have studied the impact of HII exposure on glucose tolerance, insulin sensitivity, pancreatic islet morphology, muscle GLUT4 and plasma insulin and corticosterone levels. Normal and glucose intolerant wild-type Wistar rats were randomly divided in two groups: one group not exposed to HII and the other continuously exposed to HII.

Periodontal status, perceived stress, diabetes mellitus and oral hygiene care on quality of life: a structural equation modelling analysis.

Background: To determine if periodontal risk assessment (PRA), the number of missing teeth, diabetes mellitus (DM), perceived stress and interproximal cleaning are associated with oral health-related quality of life (OHRQoL), using Andersen's behavioral modelling (ABM).

Material And Methods: Data derived from 472 adults derived from a representative population of the Study of Periodontal Health in Almada-Seixal (SoPHiAS) was used. Socioeconomic status, perceived stress scale (PSS-10), oral health behaviors and oral health impact profile (OHIP-14) were collected through questionnaire.

Effects of high-intensity infrasound on liver lipid content of rats.

Previous experimental studies show that exposure to noise with high and audible frequencies causes multiple metabolic alterations, such as increased liver glycogen and triglycerides. However, the effect of exposure to sound with lower frequencies, such as high-intensity infrasound (frequency <20 Hz and sound pressure level >90 dB), on the liver lipid content is still unclear. As such, we aimed to study the effect of exposure to high-intensity infrasound of both normal and glucose intolerant rats on the liver lipid content.

Perceived xerostomia, stress and periodontal status impact on elderly oral health-related quality of life: findings from a cross-sectional survey.

Background: To investigate if self-perceived xerostomia and stress are significant variables on the Oral-Health Related Quality of Life (OHRQoL) of elderly patients, considering the periodontal status, oral hygiene habits and sociodemographic characteristics simultaneously.

Methods: The study cohort included 592 participants (320 females/272 Males), aged 65 years or older, representing the elder inhabitants of the Study of Periodontal Health in Almada-Seixal (SoPHiAS). Patients answered a socio-demographic and oral hygiene habits questionnaire.

Normality in medicine: a critical review.

What is considered normal determines clinical practice in medicine and has implications at an individual level, doctor-patient relationship and health care policies. With the increase in medical information and technical abilities it is urgent to have a clear concept of normality in medicine so that crucial discussions can be held with unequivocal terms.The different meanings for normality were analyzed throughout the literature and grouped according to their relevance in the academic community in models, namely the Biostatistical Theory (BST), Health, Ideal, Process and Biological advantage.

The inflammasome in host response to biomaterials: Bridging inflammation and tissue regeneration.

The development of new biomaterials to be used in tissue engineering applications is creating new solutions for a range of healthcare problems. The trend in biomaterials research has shifted from biocompatible "immune-evasive" biomaterials to "immune-interactive" materials that modulate the inflammatory response supporting implant integration as well as improving healing and tissue regeneration. Inflammasomes are large intracellular multiprotein complexes that are key players in host defence during innate immune responses and assemble after recognition of pathogens or danger signals.

Chitosan porous 3D scaffolds embedded with resolvin D1 to improve in vivo bone healing.

The aim of this study was to investigate the effect chitosan (Ch) porous 3D scaffolds embedded with resolvin D1 (RvD1), an endogenous pro-resolving lipid mediator, on bone tissue healing. These scaffolds previous developed by us have demonstrated to have immunomodulatory properties namely in the modulation of the macrophage inflammatory phenotypic profile in an in vivo model of inflammation. Herein, results obtained in an in vivo rat femoral defect model demonstrated that two months after Ch + RvD1 scaffolds implantation, an increase in new bone formation, in bone trabecular thickness, and in collagen type I and Coll I/Coll III ratio were observed.

Low-frequency noise effects on the rat parotid gland: A transmission electron microscopy study.

Introduction: Low-frequency noise (LFN) is a ubiquitous physical stressor known to cause degenerative cellular changes and organ alterations with functional repercussions both in humans and animals.

Materials And Methods: After acceptance of the study protocol by a local ethics committee, 20 Wistar rats were randomly divided into two equal groups. One group was kept in silence and the other continuously exposed to LFN during 13 weeks.

Endothelial Dysfunction and Nailfold Videocapillaroscopy Pattern as Predictors of Digital Ulcers in Systemic Sclerosis: a Cohort Study and Review of the Literature.

Raynaud's phenomenon and digital ulcers (DUs) are frequent among systemic sclerosis (SSc) patients. Our aim was to investigate the diagnostic and predictive value for DU of endothelial dysfunction biomarkers (flow-mediated dilatation (FMD), serum levels of endothelin-1 (ET-1), and ADMA), angiogenic/angiostatic biomarkers (vascular endothelial growth factor (VEGF), endoglin, and endostatin), and nailfold videocapillaroscopy (NVC). We compared our results with a literature review.

Development of an immunomodulatory biomaterial: using resolvin D1 to modulate inflammation.

In our search for immunomodulatory biomaterials capable of modulating the inflammatory response through M2 macrophage polarization, we report here on a new strategy that resulted from the incorporation of resolvin D1 (RvD1), a pro-resolution lipid mediator in porous 3D chitosan (Ch) scaffolds, followed by its lyophilisation. We have investigated the inflammatory response caused by this biomaterial in vivo using a mouse air-pouch model of inflammation. We found that this developed material caused a decrease in inflammatory cells recruited to the implant site, together with higher numbers of F4/80(+)/CD206(+) cells (M2 macrophages) and lower numbers of F4/80(+)/CCR7(+) cells (M1 macrophages).

High concentration of phosphorus is a distinctive feature of myelin. An X-ray elemental microanalysis study using freeze-fracture scanning electron microscopy of rat sciatic nerve.

We have used rat sciatic nerves submitted to freezing and freeze-fracture to determine the elemental composition of small domains of the peripheral nerve studied at high resolution by scanning electron microscopy. We found that myelin of Schwann cells is unique in its high content in phosphorus (P) that was more than 10 times higher than P measured in any other cells. This high concentration in P makes myelin chemistry suitable of monitoring at the subcellular level using the herein described methodology.

Industrial noise and tooth wear - experimental study.

Unlabelled: Tooth wear is a complex multifactorial process that involves the loss of hard dental tissue. Parafunctional habits have been mentioned as a self-destructive process caused by stress, which results in hyperactivity of masticatory muscles. Stress manifests itself through teeth grinding, leading to progressive teeth wear.

Modulation of the inflammatory response to chitosan through M2 macrophage polarization using pro-resolution mediators.

Tissue engineering and regenerative medicine have created a demand for biomaterials with specific functions such as the ability to modify the host immune response. The objective of this study was to evaluate the effect of two different pro-resolution lipid mediators, lipoxin A4 (LxA4) and resolvin D1 (RvD1), in the modulation of the inflammatory response to biomaterials through M2 macrophage polarization. This was investigated in vivo using a mouse air-pouch model of inflammation.

Increased lung inflammation with oxygen supplementation in tracheotomized spontaneously breathing rabbits: an experimental prospective randomized study.

Background: Mechanical ventilation is a well-known trigger for lung inflammation. Research focuses on tidal volume reduction to prevent ventilator-induced lung injury. Mechanical ventilation is usually applied with higher than physiological oxygen fractions.

Immunosuppression abrogates resistance of young rabbits to Rabbit Haemorrhagic Disease (RHD).

Rabbit Haemorrhagic Disease (RHD) is caused by a calicivirus (RHDV) that kills 90% of infected adult European rabbits within 3 days. Remarkably, young rabbits are resistant to RHD. We induced immunosuppression in young rabbits by treatment with methylprednisolone acetate (MPA) and challenged the animals with RHDV by intramuscular injection.

Effects of low-frequency noise on cardiac collagen and cardiomyocyte ultrastructure: an immunohistochemical and electron microscopy study.

Introduction: Low-frequency noise (LFN) leads to the development of tissue fibrosis. We previously reported the development of myocardial and perivascular fibrosis and a reduction of cardiac connexin43 in rats, but data is lacking concerning the affected type of collagen as well as the ultrastructural myocardial modifications.

Objectives: The aim of this study was to quantify cardiac collagens I and III and to evaluate myocardial ultrastructural changes in Wistar rats exposed to LFN.

Macrophage polarization following chitosan implantation.

Macrophages are a key cell in the host response to implants and can be polarized into different phenotypes capable of inducing both detrimental and beneficial outcomes in tissue repair and remodeling, being important in tissue engineering and regenerative medicine. The objective of this study was to evaluate the macrophage response to 3D porous chitosan (Ch) scaffolds with different degrees of acetylation (DA, 5% and 15%). The M1/M2 phenotypic polarization profile of macrophages was investigated in vivo using a rodent air-pouch model.

Immunohistochemical evaluation of cardiac connexin43 in rats exposed to low-frequency noise.

Introduction: Low-frequency noise (LFN) leads to an abnormal proliferation of collagen and development of tissue fibrosis. It has been shown that myocardial fibrosis in association with gap junction remodeling occurs in several cardiac diseases and can be implicated in the development of ventricular tachyarrhythmias. We previously reported a strong development of myocardial fibrosis induced by LFN in rats but it is not known whether LFN induces any modification on cardiac connexin43 (Cx43).

Histomorphometric evaluation of the coronary artery vessels in rats submitted to industrial noise.

Introduction: Industrial noise (IN) is characterized by high intensity and a wide spectrum of wavelengths that induce physical vibration on the body structures. This effect, resulting from the low-frequency sound waves, can lead to pathological alterations in the extracellular matrix with an abnormal proliferation of collagen and development of tissue fibrosis, in the absence of an inflammatory process.

Objective: The aim of this study was to evaluate the modifications of the arterial coronary vessels in Wistar rats submitted to IN.

Myocardial fibrosis in rats exposed to low frequency noise.

Unlabelled: Low frequency noise (LFN) characterized by large pressure amplitude (> or =90 dB SPL) and low frequency bands (< or =500 Hz) can lead to structural and ultrastructural modifications in the extracellular matrix of several tissues, with an abnormal proliferation of collagen and development of fibrosis. It is not known whether LFN induces similar structural alterations in the ventricular myocardium of rats.

Objective: The aim of this study was to evaluate and measure the myocardial fibrosis induced by LFN.

Effects of large pressure amplitude low frequency noise in the parotid gland perivasculo-ductal connective tissue.

Introduction: In tissues and organs exposed to large pressure amplitude low frequency noise fibrosis occurs in the absence of inflammatory signs, which is thought to be a protective response. In the parotid gland the perivasculo-ductal connective tissue surrounds arteries, veins and the ductal tree. Perivasculo-ductal connective tissue is believed to function as a mechanical stabilizer of the glandular tissue.