Preparation and characterization of collagen-based ADSC-carrier sheets for cardiovascular application

The use of scaffolds composed of natural biodegradable matrices represents an attractive strategy to circumvent the lack of cell engraftment, a major limitation of stem cell therapy in cardiovascular diseases. Bovine-derived non-porous collagen scaffolds with different degrees of cross-linking (C0, C2, C5 and C10) were produced and tested for their mechanical behavior, in vitro biocompatibility with adipose-derived stem cells (ADSCs) and tissue adhesion and inflammatory reaction. Uniaxial tensile tests revealed an anisotropic behavior of collagen scaffolds (2 × 0.5 cm) and statistically significant differences in the mechanical behavior between cross-linked and non-cross-linked scaffolds (n = 5). In vitro, ADSCs adhered homogenously and showed a similar degree of proliferation on all four types of scaffolds (cells × 10³ cm^?2 at day 7: C0: 94.7 ± 37.1; C2: 91.7 ± 25.6; C5: 88.2 ± 6.8; C10: 72.8 ± 10.7; P = n.s.; n = 3). In order to test the in vivo biocompatibility, a chronic myocardial infarction model was performed in rats and 1.2 × 1.2 cm size collagen scaffolds implanted onto the heart 1 month post-infarction. Six animals per group were killed 2, 7 and 30 days after transplant. Complete and long-lasting adhesion to the heart was only observed with the non-cross-linked scaffolds with almost total degradation 1 month post-transplantation. After 7 and 30 days post-implantation, the degree of inflammation was significantly lower in the hearts treated with non-cross-linked scaffolds (day 7: C0: 10.2 ± 2.1%; C2: 16.3 ± 2.9%; C5: 15.9 ± 4.8%; C10: 17.4 ± 4.1%; P < 0.05 vs. C0; day 30: C0: 1.3 ± 1.3%; C2: 9.4 ± 3.0%; C5: 7.0 ± 2.1%; C10: 9.8 ± 2.5%; P < 0.01 vs. C0). In view of the results, the non-cross-linked scaffold (C0) was chosen as an ADSC-carrier sheet and tested in vivo. One week post-implantation, 25.3 ± 7.0% of the cells transplanted were detected in those animals receiving the cell-carrier sheet whereas no cells were found in animals receiving cells alone (n = 3 animals/group).We conclude that the biocompatibility and mechanical properties of the non-cross-linked collagen scaffolds make them a useful cell carrier that greatly favors tissue cell engraftment and may be exploited for cell transplantation in models of cardiac disease.     

Temporomandibular disorders and mandibular vertical asymmetry

Objective To analyze the association between mandibular vertical asymmetry and the presence of TMD in adult patients.

Methods This case-control study recruited patients from the orthodontic clinic at FEBUAP. Patients were classified on the basis of diagnostic criteria for temporomandibular disorders (DC/TMD). Panoramic radiographs were measured to determine mandibular vertical asymmetry indices according to criteria described by Kjellberg and Habets. Both methods (DC/TMD and index criteria) were standardized a priori.

Results A total of 56 patients were analyzed, of whom 25 (44.6%) met the inclusion criteria and were divided into two groups (TMD group, n = 15; non-TMD group, n = 10). The highest asymmetry index was observed in the condylar neck, followed by the total condylar asymmetry index, but without significant differences between groups (p > .05).

Conclusion There is no association (p > .05) between temporomandibular disorders and mandibular vertical asymmetry.     

Variability of respiratory symptoms in severe COPD

Introduction

While it is known that asthma symptoms have a very variable pattern, the general belief is that the respiratory symptoms in COPD patients usually present little or no variability. Nevertheless, COPD patients report having “bad days”. The objective of this present study was to evaluate the variability of the respiratory symptoms and their impact on the daily activities of a cohort of Spanish COPD patients.

Method

We present the results of the Spanish patients who participated in a cross-sectional epidemiological study carried out in 17 European countries. Pulmonologists and Family Care physicians recruited patients with stable severe COPD (FEV1 < 50%). The perception of the patients on the variation in their symptoms was recorded by telephone interviews.

Results

A total of 472 patients provided data that was valid for analysis. Mean age was 68.6; 93% were men; mean FEV1(%) was 41%. 84.1% of the patients experimented at least one respiratory symptom in the previous week and 60.9% affirmed that their symptoms varied over the course of the day or week. The moment of the day when the symptoms were perceived to be more intense was during the morning.

Conclusions

An important proportion of severe COPD patients perceive variability in their respiratory symptoms, with a greater intensity in the morning. The observation can have implications in treating patients with severe COPD as variability can be an initial sign of decompensation of the disease.     

Non-invasive Ventilation in an Elderly Population Admitted to a Respiratory Monitoring Unit: Causes, Complications and One-year Evolution

OBJECTIVE: To determine the usefulness of non-invasive ventilation (NIV) in elderly patients (≥75) admitted to a respiratory monitoring unit (RMU) during hospitalization and one year later in comparison with the results from the younger age group (<75). MATERIAL AND METHODS: Ours is a prospective observational study carried out at the Hospital Universitario La Princesa (Madrid, Spain). We recruited all patients who were ≥75 years old and were admitted to our RMU during the period 2008-2009 with respiratory acidosis (pH <7.35 and PaCO(2) >45mmHg) requiring NIV. We gathered data for basic variables as well as sociodemographics, history of previous pathologies, reason for hospitalization and severity, analysis upon admission and the evolution of blood gases at the start of NIV (within the first hour and after 24hours), complications and evolution at the one-year follow-up. RESULTS: Mean age of the sample was 80.6 years. The Charlson index was 3.27. About half of the patients had some limitation for performing daily activities. The main reasons for admission were COPD exacerbation and heart failure. There were complications in 36% of the cases (11 renal failure and 6 atrial fibrillation). The survival rate at the one-year follow-up was 63.21%. CONCLUSIONS: NIV is a good alternative in elderly patients admitted to the hospital with respiratory acidosis. We did not detect differences in mortality during admission between the two groups. The elderly patients were more frequently re-admitted than the younger group in the 6-12 months after hospital discharge. This could be due to their poorer functional state after hospitalization requiring NIV.