Focus on collagen: in vitro systems to study fibrogenesis and antifibrosis _ state of the art

Fibrosis represents a major global disease burden, yet a potent antifibrotic compound is still not in sight. Part of the explanation for this situation is the difficulties that both academic laboratories and research and development departments in the pharmaceutical industry have been facing in re-enacting the fibrotic process in vitro for screening procedures prior to animal testing. Effective in vitro characterization of antifibrotic compounds has been hampered by cell culture settings that are lacking crucial cofactors or are not holistic representations of the biosynthetic and depositional pathway leading to the formation of an insoluble pericellular collagen matrix. In order to appreciate the task which in vitro screening of antifibrotics is up against, we will first review the fibrotic process by categorizing it into events that are upstream of collagen biosynthesis and the actual biosynthetic and depositional cascade of collagen I. We point out oversights such as the omission of vitamin C, a vital cofactor for the production of stable procollagen molecules, as well as the little known in vitro tardy procollagen processing by collagen C-proteinase/BMP-1, another reason for minimal collagen deposition in cell culture. We review current methods of cell culture and collagen quantitation vis-à-vis the high content options and requirements for normalization against cell number for meaningful data retrieval. Only when collagen has formed a fibrillar matrix that becomes cross-linked, invested with ligands, and can be remodelled and resorbed, the complete picture of fibrogenesis can be reflected in vitro. We show here how this can be achieved. A well thought-out in vitro fibrogenesis system represents the missing link between brute force chemical library screens and rational animal experimentation, thus providing both cost-effectiveness and streamlined procedures towards the development of better antifibrotic drugs

Fatores associados às complicações em crianças pré-escolares com pneumonia adquirida na comunidade Factors associated with complications of community-acquired pneumonia in preschool children

OBJETIVO: Identificar os fatores socioeconômicos e clínicos associados à evolução para complicações em crianças internadas com pneumonia adquirida na comunidade (PAC). MÉTODOS: Estudo longitudinal prospectivo em crianças diagnosticadas com PAC (12-59 meses de idade) internadas em enfermarias gerais de pediatria de dois hospitais na região de Campinas (SP). Os critérios de exclusão foram ter fibrose cística, cardiopatia, malformação pulmonar, neuropatias e doenças genéticas. PAC foi diagnosticada por características clínicas e radiológicas. Os dados foram coletados dos prontuários médicos e por um questionário semiestruturado. Os sujeitos foram divididos em dois grupos (PAC complicada e não complicada). Foram comparadas variáveis socioeconômicas e clínicas, e foi realizada análise de regressão logística multivariada. RESULTADOS: Das 63 crianças incluídas, 29 e 34, respectivamente, apresentaram PAC não complicada e PAC complicada. Não houve diferenças estatisticamente significantes entre os grupos quanto a idade na admissão, idade gestacional, peso ao nascer, gênero ou variáveis socioeconômicas. Houve diferenças significantes entre os grupos em relação a pneumonia anterior (p = 0,03), antibioticoterapia prévia (p = 0,004), tempo de início da doença (p = 0,01), duração da febre antes da internação (p < 0,001), duração da antibioticoterapia (p < 0,001) e tempo de internação (p < 0,001). Na análise multivariada, somente permaneceu no modelo a duração da febre antes da internação (OR = 1,97; IC95%: 1,36-2,84; p < 0,001). CONCLUSÕES: Variáveis biológicas, com destaque para o tempo de febre anterior à internação, parecem estar associadas com a evolução para complicação em crianças com PAC.<br>OBJECTIVE: To identify socioeconomic factors and clinical factors associated with the development of complications in preschool children hospitalized with community-acquired pneumonia (CAP). METHODS: This was a prospective longitudinal study involving children (12-59 months of age) diagnosed with CAP and admitted to the pediatric wards of two hospitals in the metropolitan area of Campinas, Brazil. Children with cystic fibrosis, heart disease, pulmonary malformations, neurological disorders, or genetic diseases were excluded. The diagnosis of CAP was based on clinical and radiological findings. Data were collected from the medical records and with a semi-structured questionnaire. The subjects were divided into two groups (complicated and uncomplicated CAP). Socioeconomic and clinical variables were compared, and multivariate logistic regression analysis was performed. RESULTS: Of the 63 children included, 29 and 34, respectively, presented with uncomplicated and complicated CAP. No statistically significant differences were found between the groups regarding age at admission, gestational age, birth weight, gender, or socioeconomic variables. Significant differences were found between the groups regarding history of pneumonia (p = 0.03), previous antibiotic therapy (p = 0.004), time elapsed since the onset of CAP (p = 0.01), duration of fever prior to admission (p < 0.001), duration of antibiotic therapy (p < 0.001), and length of hospital stay (p < 0.001). In the multivariate analysis, only duration of fever prior to admission remained in the model (OR = 1.97; 95% CI: 1.36-2.84; p < 0.001). CONCLUSIONS: Biological variables, especially duration of fever prior to admission, appear to be associated with the development of complications in children with CAP

Prevalence and clinical features of respiratory syncytial virus in children hospitalized for community-acquired pneumonia in northern Brazil

<p>Abstract</p> <p>Background</p> <p>Childhood pneumonia and bronchiolitis is a leading cause of illness and death in young children worldwide with Respiratory Syncytial Virus (RSV) as the main viral cause. RSV has been associated with annual respiratory disease outbreaks and bacterial co-infection has also been reported. This study is the first RSV epidemiological study in young children hospitalized with community-acquired pneumonia (CAP) in Belém city, Pará (Northern Brazil).</p> <p>Methods</p> <p>With the objective of determining the prevalence of RSV infection and evaluating the patients’ clinical and epidemiological features, we conducted a prospective study across eight hospitals from November 2006 to October 2007. In this study, 1,050 nasopharyngeal aspirate samples were obtained from hospitalized children up to the age of three years with CAP, and tested for RSV antigen by direct immunofluorescence assay and by Reverse Transcription Polymerase Chain Reaction (RT-PCR) for RSV Group identification.</p> <p>Results</p> <p>RSV infection was detected in 243 (23.1%) children. The mean age of the RSV-positive group was lower than the RSV-negative group (12.1 months vs 15.5 months, <it>p</it><0.001) whereas gender distribution was similar. The RSV-positive group showed lower means of C-reactive protein (CRP) in comparison to the RSV-negative group (15.3 vs 24.0 mg/dL, <it>p</it><0.05). Radiological findings showed that 54.2% of RSV-positive group and 50.3% of RSV-negative group had interstitial infiltrate. Bacterial infection was identified predominantly in the RSV-positive group (10% vs 4.5%, p<0.05). Rhinorrhea and nasal obstruction were predominantly observed in the RSV-positive group. A co-circulation of RSV Groups A and B was identified, with a predominance of Group B (209/227). Multivariate analysis revealed that age under 1 year (<it>p</it><0.015), CRP levels under 48 mg/dL (<it>p</it><0.001) and bacterial co-infection (<it>p</it><0.032) were independently associated with the presence of RSV and, in the analyze of symptoms, nasal obstruction were independently associated with RSV-positive group (<it>p</it><0.001).</p> <p>Conclusion</p> <p>The present study highlights the relevance of RSV infection in hospitalized cases of CAP in our region; our findings warrant the conduct of further investigations which can help design strategies for controlling the disease.</p

A molecular epidemiological study of respiratory viruses detected in Japanese children with acute wheezing illness

<p>Abstract</p> <p>Background</p> <p>Recent studies strongly suggest that some respiratory viruses are associated with the induction of acute wheezing and/or exacerbation of bronchial asthma. However, molecular epidemiology of these viruses is not exactly known.</p> <p>Methods</p> <p>Using PCR technology, we attempted to detect various respiratory viruses from 115 Japanese children. Furthermore, the detected viruses were subjected to homology, pairwise distance, and phylogenetic analysis.</p> <p>Results</p> <p>Viruses were detected from 99 (86.1%) patients. Respiratory syncytial virus (RSV) alone and human rhinovirus (HRV) alone were detected in 47 (40.9%) and 36 (31.3%) patients, respectively. Both RSV and HRV were detected in 14 (12.2%) patients. Human metapneumovirus (HMPV) alone and human parainfluenza virus (HPIV) alone were detected in 1 (0.9%) patient each, respectively. Homology and phylogenetic analyses showed that the RSV and HRV strains were classified into genetically diverse species or subgroups. In addition, RSV was the dominant virus detected in patients with no history of wheezing, whereas HRV was dominant in patients with a history of wheezing.</p> <p>Conclusions</p> <p>The results suggested that these genetically diverse respiratory viruses, especially RSV and HRV, might be associated with wheezing in Japanese children.</p