Evaluation of different RGD ligand densities in the development of cell-based drug delivery systems

Background: The inclusion of the tripeptide Arg-Gly-Asp (RGD) in otherwise inert biomaterials employed for cell encapsulation has been observed to be an effective strategy to provide the immobilized cells with a more suitable microenvironment.

Purpose: The objective of this study was to determine the impact of different RGD densities on the behavior of baby hamster kidney (BHK) fibroblasts able to secrete vascular endothelial growth factor (VEGF) encapsulated in alginate microcapsules.

Methods: Alginate was modified by varying the concentration of RGD peptides in the coupling reaction. After obtaining four different types of alginate, cells were encapsulated in alginate-poly-l-lysine-alginate (APA) microcapsules.

Results and discussion: The results obtained after viability, cell proliferation and VEGF secretion assays showed that the inclusion of RGD in alginate enhances the functionality of immobilized cells, obtaining the highest values with the intermediate RGD density.

Conclusion: These results put in evidence that alginate modification influences the behavior of immobilized cells but even more that the employed density of the tripeptide is of crucial importance, obtaining in some cases even excessive activity of the encapsulated cells.     

Pregnancy associated plasma protein A, a novel, quick, and sensitive marker in ST-elevation myocardial infarction

Traditional biomarkers in acute coronary syndromes reflect myocardial necrosis but not the underlying arteriosclerotic disease. Pregnancy-associated plasma protein A (PAPP-A) is a new biomarker in acute coronary syndromes that detects vulnerable plaques in arteriosclerotic disease and identifies acute coronary syndromes earlier than traditionally used biomarkers. Information regarding circulating PAPP-A levels in patients with ST elevation myocardial infarctions (STEMIs) is limited and contradictory. The aim of the present study was to describe the presence and time-related pattern of circulating PAPP-A levels in patients with STEMIs. Consecutive patients (n = 354) referred for primary percutaneous intervention because of STEMI were included in the study. Blood samples for the analysis of PAPP-A, creatine kinase-MB (CKMB), and troponin T were drawn at admission and every 6 to 8 hours until biomarkers of myocardial necrosis were consistently decreasing. PAPP-A was measured using a newly developed sandwich enzyme-linked immunosorbent assay technique based on 2 monoclonal antibodies. In total, 1,091 PAPP-A, 1,049 troponin T, and 1,016 CKMB samples were analyzed. Mean PAPP-A values at admission were significantly higher in patients with STEMIs than in those with non-ST elevation myocardial infarctions or unstable angina pectoris (27.6 vs 12.2 mIU/L, p <0.01). In samples drawn <2 hours after admission, the sensitivity of PAPP-A was superior (93%) to that of CKMB (60%) and troponin T (61%). In conclusion, PAPP-A levels are elevated in >90% of patients presenting with STEMIs if measured <6 hours after the onset of symptoms or <2 hours of primary percutaneous coronary intervention. In the early stages of STEMI, PAPP-A seems to be a more sensitive marker of myocardial infarction than CKMB and troponin T.     

A protein profile study to discriminate CIN lesions from normal cervical epithelium

Background

Cervical intraepithelial neoplasia (CIN), a frequently encountered disease caused by Human Papilloma Virus (HPV) is often diagnosed in formaldehyde-fixed paraffin embedded (FFPE) punch biopsies. Since it is known that this procedure strongly affects the water-soluble proteins contained in the cervical tissue we decided to investigate whether a water-soluble protein-saving biopsy processing method can be used to support the diagnosis of normal and CIN.

Methods

Cervical punch biopsies from 55 women were incubated for 24 h at 4°C in RPMI1640 medium for protein analysis prior to usual FFPE processing and p16 and Ki67-supported histologic consensus diagnosis was assessed. The biopsy supernatants were subjected to surface-enhanced laser desorption-ionization time of flight mass spectrometry (SELDI-TOF MS) for identifying differentially expressed proteins. Binary logistic regression and classification and regression trees (CART) were used to develop a classification model.

Results

The age of the patients ranged from 26 to 40 years (median 29.7). The consensus diagnoses were normal cervical tissue (n?=?10) and CIN2-3 (n?=?45). The mean protein concentration was 1.00 and 1.09 mg/ml in the normal and CIN2-3 group, respectively. The peak detection and clustering process resulted in 40 protein peaks. Many of these peaks differed between the two groups, but only three had independent discriminating power. The overall classification results were 88%.

Conclusions

Water-soluble proteins sampled from punch biopsies are promising to assist the diagnosis of normal and CIN2-3.     

Trauma exposure in childhood impairs the ability to recall specific autobiographical memories in late adolescence

J. M. G. Williams (1996) predicted that exposure to potentially traumatizing events at an early age would give rise to overgeneral recall from autobiographical memory, i.e., recall of general rather than specific events, and that in adolescence this tendency would be uncorrelated with psychopathological symptoms, e.g., depression. This was supported by two studies where war‐exposed Bosnian adolescents produced significantly fewer specific autobiographical memories than a Norwegian control group, as did bombing‐exposed Serbian adolescents compared to nontrauma‐exposed Serbians. No significant correlations were found between autobiographical memory specificity and measures of depression, anxiety, dissociation or impact of trauma, which is consistent with Williams' idea that an overgeneral memory retrieval strategy is at first protective, and a risk factor for depression only upon reaching adulthood.     

Prevalence of 4977bp deletion in mitochondrial DNA from patients with chronic kidney disease receiving conservative treatment or hemodialysis in southern Brazil

BACKGROUND: Damage to mitochondrial DNA (mtDNA) has been described in patients with chronic kidney disease (CKD). The presence of mtDNA 4977bp deletion in many different tissues can serve as a marker of this damage. However, no attempt has been made to detect the presence of mtDNA 4977bp in blood cells of patients with CKD. METHODS: Polymerase chain reaction techniques (PCR) were used to detect mtDNA 4977bp deletion in blood samples of 94 CKD patients. RESULTS: The prevalence of 4977bp deletion in mtDNA was 73.1% (38/52) in patients with CKD undergoing hemodialysis, 57.1% (27/42) in patients with CKD receiving conservative treatment, and 27.8% (15/54) in control samples (p < 0.001). Higher prevalence of this mutation was not associated with patient age (p = 0.54) or time on hemodialysis (p = 0.70). CONCLUSION: The higher prevalence of mtDNA 4977bp deletion in patients in this study indicates that the CKD can induce damage to mtDNA in blood cells and could be exacerbated by hemodialysis.     

Private costs almost equal health care costs when intervening in mild Alzheimer's: a cohort study alongside the DAISY trial

Background  

Alzheimer's disease is the leading cause of dementia and affects about 25 million people worldwide. Recent studies have evaluated the effect of early interventions for dementia, but few studies have considered private time and transportation costs associated with the intervention. This study assessed the total economic costs associated with a multifaceted intervention for mild Alzheimer's disease, including an estimate of the ratio of public to private costs.