Scaffolds for heart valve tissue engineering must function immediately after implantation but also need to tolerate cell infiltration and gradual remodeling. We hypothesized that moderately cross-linked collagen scaffolds would fulfill these requirements. To test our hypothesis, scaffolds prepared from decellularized porcine pericardium were treated with penta-galloyl glucose (PGG), a collagen-binding polyphenol, and tested for biodegradation, biaxial mechanical properties, and in vivo biocompatibility. For controls, we used un-cross-linked scaffolds and glutaraldehyde-treated scaffolds. Results confirmed complete pericardium decellularization and the ability of scaffolds to encourage fibroblast chemotaxis and to aid in creation of anatomically correct valve-shaped constructs. Glutaraldehyde cross-linking fully stabilized collagen but did not allow for tissue remodeling and calcified when implanted subdermally in rats. PGG-treated collagen was initially resistant to collagenase and then degraded gradually, indicating partial stabilization. Moreover, PGG-treated pericardium exhibited excellent biaxial mechanical properties, did not calcify in vivo, and supported infiltration by host fibroblasts and subsequent matrix remodeling. In conclusion, PGG-treated acellular pericardium is a promising scaffold for heart valve tissue engineering.
MethodsWe analysed 48,000 gene transcripts in 132 invasive breast carcinomas to identify two novel genes (OATP2 and FABP7) significantly associated with BP (defined by cytokeratin (CK)5/6 and/or CK14 positivity). Using a series of invasive breast carcinoma cases (n=899), prepared as tissue microarrays, we assessed OATP2 and FABP7 protein expression using immuncocytochemistry to investigate associations with clinicopathological variables, patients" outcome and ability to refine BP classification.
ResultsA total of 7.9% and 15.6% cases were OATP2 and FABP7 positive respectively. OATP2 was associated with tumours of high histological grade (p<0.01), ER and PgR negativity (p<0.01) and shorter breast cancer specific survival (BCSS; p=0.04). FABP7 expression was associated with lower lymph node stage (p<0.01), ER and PgR negativity (p<0.01). BP tumours which were FABP7 positive had a significantly longer BCSS (p=0.05) and disease-free survival (DFS; p=0.01) compared with FABP7 negative basal tumours (p<0.01). OATP2 positive tumours were associated with adverse survival and increased risk of early recurrence.
ConclusionsThis study confirms the biological and clinical heterogeneity of the BP in breast cancer. We have
Acquired brain injury (ABI) entails any injury that disrupts neuronal activity and is not degenerative, hereditary, congenital, or induced by birth trauma. Traditional examples of ABI include not only stroke and traumatic brain injury (TBI), but also near drowning, aneurysm, tumor, meningitis and other infections involving the brain, and injuries resulting from lack of oxygen supply to the brain, such as those seen in myocardial infarction. ABI may involve a structural insult, changes to metabolic activity, or disruption to neuronal capabilities.While progressive loss of brain cells and debilitating motor and cognitive deficits play a role in all these disorders, stroke and TBI overlap particularly closely in pathology and impose an immense burden on the American and global populations.
AbstractIschemic stroke and traumatic brain injury (TBI) comprise two particularly prevalent and costly examples of acquired brain injury (ABI). Following stroke or TBI, primary cell death and secondary cell death closely model disease progression and worsen outcomes. Mounting evidence indicates that long-term neuroinflammation extensively exacerbates the secondary deterioration of brain structure and function. Due to their immunomodulatory and regenerative properties, mesenchymal stem cell transplants have emerged as a promising approach to treating this facet of stroke and TBI pathology. In this review, we summarize the classification of cell death in ABI and discuss the prominent role of inflammation. We then consider the efficacy of bone marrow-derived mesenchymal stem/stromal cell (BM-MSC) transplantation as a therapy for these injuries. Finally, we examine recent laboratory and clinical studies utilizing transplanted BM-MSCs as antiinflammatory and neurorestorative treatments for stroke and TBI. Clinical trials of BM-MSC transplants for stroke and TBI support their promising protective and regenerative properties. Future research is needed to allow for better comparison among trials and to elaborate on the emerging area of cell-based combination treatments.
K E Y W O R D Sbone marrow-derived mesenchymal stem cells, clinical trials, inflammation, ischemic stroke, preclinical studies, traumatic brain injury
Structure-activity relationships were investigated on a novel series of tricyclic dihydropyridine-containing K(ATP) openers. This diverse group of analogues, comprising a variety of heterocyclic rings fused to the dihydropyridine nucleus, was designed to determine the influence on activity of hydrogen-bond-donating and -accepting groups and their stereochemical disposition. Compounds were evaluated for K(ATP) activity in guinea pig bladder cells using a fluorescence-based membrane potential assay and in a pig bladder strip assay. The inhibition of spontaneous bladder contractions in vitro was also examined for a subset of compounds. All compounds studied showed greater potency to inhibit spontaneous bladder contractions relative to their potencies to inhibit contractions elicited by electrical stimulation.
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