Respiratory infections and coinfections: geographical and population patterns

Introduction

Acute respiratory infections are the second cause of mortality in children younger than five years, with 150.7 million episodes per year. Human orthopneumovirus (hOPV) and metapneumovirus (hMPV) are the first and second causes of bronchiolitis; type 2 human orthorubulavirus (hORUV) has been associated with pneumonia in immunocompromised patients.

Objective

To define hOPV, hMPV and hORUV geographical distribution and circulation patterns.

Method

An observational, prospective cross-sectional pilot study was carried out. Two-hundred viral strains obtained from pediatric patients were genotyped by endpoint reverse transcription polymerase chain reaction (RT-PCR).

Results

One-hundred and eighty-six positive samples were typed: 84 hOPV, 43 hMPV, two hORUV and 57 co-infection specimens. Geographical distribution was plotted. hMPV, hOPV, and hORUV cumulative incidences were 0.215, 0.42, and 0.01, respectively. Cumulative incidence of hMPV-hORUV and hMPV-hOPV coinfection was 0.015 and 0.23; for hOPV-hMPV-hORUV, 0.035; and for hORUV-hOPV, 0.005. The largest number of positive cases of circulating or co-circulating viruses occurred between January and March.

Conclusions

This study successfully identified circulation and geographical distribution patterns of the different viruses, as well as of viral co-infections.

Isolation of human mesenchymal stem cells and their cultivation on the porous bone matrix

Mesenchymal stem cells (MSCs) have a differentiation potential towards osteoblastic lineage when they are stimulated with soluble factors or specific biomaterials. This work presents a novel option for the delivery of MSCs from human amniotic membrane (AM-hMSCs) that employs bovine bone matrix Nukbone (NKB) as a scaffold. Thus, the application of MSCs in repair and tissue regeneration processes depends principally on the efficient implementation of the techniques for placing these cells in a host tissue. For this reason, the design of biomaterials and cellular scaffolds has gained importance in recent years because the topographical characteristics of the selected scaffold must ensure adhesion, proliferation and differentiation into the desired cell lineage in the microenvironment of the injured tissue. This option for the delivery of MSCs from human amniotic membrane (AM-hMSCs) employs bovine bone matrix as a cellular scaffold and is an efficient culture technique because the cells respond to the topographic characteristics of the bovine bone matrix Nukbone (NKB), i.e., spreading on the surface, macroporous covering and colonizing the depth of the biomaterial, after the cell isolation process. We present the procedure for isolating and culturing MSCs on a bovine matrix.