Aim: The present study describes the ability of a newly developed N‐terminal pro‐peptides of type IV collagen 7S domain (P4NP 7S) competitive enzyme‐linked immunosorbent assay (ELISA) for describing ...liver fibrosis. The assay applies a monoclonal antibody specific for a PIVNP 7S epitope 100% homologous in the human, rat, and mouse species.
Methods: Monoclonal antibodies were raised against selected P4NP 7S specific sequences. Antibodies were screened and a competitive ELISA assay was developed using a selected antibody. The assay was evaluated in relation to technical performance, and in two preclinical liver fibrosis models; the bile duct ligation model (BDL) and the carbon tetrachloride model (CCL4) both performed in rats.
Results: A technically robust P4NP 7S ELISA assay using a monoclonal antibody was produced. In the BDL and CCL4 liver fibrosis models it was observed that the P4NP 7S levels were significantly elevated in rat with liver fibrosis as seen by histology (CCL4: 283% elevated in the highest quartile of total hepatic collagen compared with controls, P = 0.001; BDL: 183% elevated at week 4 compared with sham, P < 0.001) and correlated to the amount of hepatic type IV collagen expression in BDL rats (r = 0.49, P < 0.05) in contrast to sham (r = −0.12). P4NP 7S also correlated to total collagen in CCL4 treated livers (P < 0.001, r = 0.67), however, not in controls (r = 0.04).
Conclusions: This newly developed serum assay specific for P4NP 7S was highly related to liver fibrosis and correlated to extent of hepatic fibrosis. This assay may improve fibrosis quantification.
Companion diagnostics (CDx) hail promise of improving the drug development process and precision medicine. However, there are various challenges involved in the clinical development and regulation of ...CDx, which are considered high-risk in vitro diagnostic medical devices given the role they play in therapeutic decision-making and the complications they may introduce with respect to their sensitivity and specificity. The European Union (E.U.) is currently in the process of bringing into effect in vitro Diagnostic Medical Devices Regulation (IVDR). The new Regulation is introducing a wide range of stringent requirements for scientific validity, analytical and clinical performance, as well as on post-market surveillance activities throughout the lifetime of in vitro diagnostics (IVD). Compliance with General Safety and Performance Requirements (GSPRs) adopts a risk-based approach, which is also the case for the new classification system. This changing regulatory framework has an impact on all stakeholders involved in the IVD Industry, including Authorized Representatives, Distributors, Importers, Notified Bodies, and Reference Laboratories and is expected to have a significant effect on the development of new CDx.
During fibrogenesis, in which excessive remodeling of the extracellular matrix occurs, both the quantity of type VI collagen and levels of matrix metalloproteinases, including MMP-2 and MMP-9, ...increase significantly. Proteolytic degradation of type VI collagen into small fragments, so-called neo-epitopes, may be specific biochemical marker of liver fibrosis. The aim of this study was to develop an ELISA detecting a fragment of type VI collagen generated by MMP-2 and MMP-9, and evaluate this assay in two preclinical models of liver fibrosis.
Mass spectrometric analysis of cleaved type VI collagen revealed a large number of protease-generated neo-epitopes. A fragment unique to type VI collagen generated by MMP-2 and MMP-9 was selected for ELISA development. The CO6-MMP assay was evaluated in two rat models of liver fibrosis: bile duct ligation (BDL) and carbon tetrachloride (CCl4)-treated rats.
Intra- and inter-assay variation was 4.1% and 10.1% respectively. CO6-MMP levels were significantly elevated in CCl(4)-treated rats compared to vehicle-treated rats at weeks 12 (mean 30.9 ng/mL vs. 12.8 ng/mL, p = 0.002); week 16 (mean 34.0 ng/mL vs. 13.7 ng/mL, p = 0.0018); and week 20 (mean 35.3 ng/mL vs. 13.3 ng/mL, p = 0.0033) with a tight correlation between hepatic collagen content and serum levels of CO6-MMP (R(2) = 0.58, p<0.0001) in CCl(4)- treated rats. In BDL rats, serum levels of CO6-MMP were significantly elevated compared to the levels in sham-operated animals both at 2 weeks (mean 29.5 ng/mL vs. 14.2 ng/mL, p = 0.0001) and 4 weeks (mean 33.0 ng/mLvs. 11.8 ng/mL, p = 0.0003).
This novel ELISA is the first assay enabling assessment of MMP degraded type VI collagen, allowing quantification of type VI collagen degradation, which would be relevant for different pathologies. The marker was highly associated with liver fibrosis in two liver fibrosis animal models, suggesting type VI turnover to be a central player in fibrogenesis.
To characterise changes in pancreatic beta cell mass during the development of diabetes in untreated male C57BLKS/J db/db mice.
Blood samples were collected from a total of 72 untreated male db/db ...mice aged 5, 6, 8, 10, 12, 14, 18, 24 and 34 weeks, for measurement of terminal blood glucose, HbA1c, plasma insulin, and C-peptide. Pancreata were removed for quantification of beta cell mass, islet numbers as well as proliferation and apoptosis by immunohistochemistry and stereology.
Total pancreatic beta cell mass increased significantly from 2.1 ± 0.3 mg in mice aged 5 weeks to a peak value of 4.84 ± 0.26 mg (P < 0.05) in 12-week-old mice, then gradually decreased to 3.27 ± 0.44 mg in mice aged 34 weeks. Analysis of islets in the 5-, 10-, and 24-week age groups showed increased beta cell proliferation in the 10-week-old animals whereas a low proliferation is seen in older animals. The expansion in beta cell mass was driven by an increase in mean islet mass as the total number of islets was unchanged in the three groups.
The age-dependent beta cell dynamics in male db/db mice has been described from 5-34 weeks of age and at the same time alterations in insulin/glucose homeostasis were assessed. High beta cell proliferation and increased beta cell mass occur in young animals followed by a gradual decline characterised by a low beta cell proliferation in older animals. The expansion of beta cell mass was caused by an increase in mean islet mass and not islet number.
Impact of Design on Medical Device Safety Miclăuş, Teodora; Valla, Vasiliki; Koukoura, Angeliki ...
Therapeutic innovation & regulatory science,
07/2020, Volume:
54, Issue:
4
Journal Article
Peer reviewed
Open access
The growing number of emerging medical technologies and sophistication of modern medical devices (MDs) that improve both survival and quality of life indexes are often challenged by alarming cases of ...vigilance data cover-up and lack of sufficient pre- and post-authorization controls. Combining Quality with Risk Management processes and implementing them as early as possible in the design of MDs has proven to be an effective strategy to minimize residual risk. This article aims to discuss how the design of MDs interacts with their safety profile and how this dipole of intended performance and safety may be supported by Human Factors Engineering (HFE) throughout the Total Product Life-Cycle (TPLC) of an MD in order to capitalize on medical technologies without exposing users and patients to unnecessary risks.
To investigate the short-term effect of ileal interposition (IT) surgery on gut morphology and enteroendocrine cell numbers in the pre-diabetic UC Davis type 2 diabetes mellitus (UCD-T2DM) rat.
...Two-month old male UCD-T2DM rats underwent either sham (n=5) or IT (n=5) surgery. Intestines were collected 1.5months after surgery. The jejunum, ileum and colon regions were processed for histochemical and immunohistochemical labeling and stereological analyses of changes in gut morphometry and number of enteroendocrine cells.
Stereological analysis showed that intestinal volume, luminal surface area and the number of all chromogranin A-positive enteroendocrine cells were markedly increased in the IT rats compared with sham-operated animals. Subanalyses of the glucagon-like peptide 2, cholecystokinin, serotonin cells and the neurotensin immunoreactive sub-pool of enteroendocrine cells in the IT region revealed an increase in numbers across phenotypes. However, the density of the different cell types varied.
IT surgery in the UCD-T2DM rat leads to rapid alterations in gut morphometry and an increase in the number of enteroendocrine cells. This effect may potentially explain why IT surgery delays the onset of type 2 diabetes in the UCD-T2DM rat.
•Ileal transposition leads to marked intestinal adaptation.•Gut hypertrophy and increased enteroendocrine cell numbers following ileal interposition•Intestinal adaptation prevents diabetes onset in a T2D rat model.
Background: During fibrogenesis in the liver, in which excessive remodelling of the extracellular matrix (ECM) occurs, both the quantity of type III collagen (CO3) and levels of matrix ...metalloproteinases (MMPs), including MMP‐9, increase significantly. MMPs play major roles in ECM remodelling, via their activity in the proteolytic degradation of extracellular macromolecules such as collagens, resulting in the generation of specific cleavage fragments. These neo‐epitopes may be used as markers of fibrosis.
Aims: The current study investigated whether a novel enzyme‐linked immunosorbent assay (ELISA) assay specifically measuring an MMP‐9‐cleaved sequence of type III collagen located at position 610 (CO3‐610C) may be used as a marker of liver fibrosis.
Material and methods: Bile duct ligation (BDL) was performed in 20 rats, with sham operations performed on another 20 rats. Serum levels of the neo‐epitope CO3‐610C (MMP‐mediated type III collagen degradation) were determined with an ELISA at 14 and 28 days post‐surgery. Liver fibrosis was evaluated by quantitative digital image analysis of Sirius red‐stained formalin‐fixed and paraffin‐embedded sections. Western blot and densitometry were performed to confirm the CO3‐610C ELISA data.
Results: CO3‐610C levels in serum increased significantly in BDL rats compared with those undergoing sham operations (% increase: 14 days=153%, P<0.0001; 28 days=134%, P=0.0014). This increase was confirmed by Western blot and densitometry of the identified bands. The CO3‐610C levels correlated to liver fibrosis (R2=0.23 and P=0.01), as evaluated by quantitative digital histology.
Discussion and conclusion: The data suggest that MMP‐9‐mediated CO3 turnover is a central event in the pathogenesis of fibrosis, and that the neo‐epitope generated may be a novel biochemical marker.
Titin is a muscle-specific protein found in cardiac and skeletal muscles which is responsible for restoring passive tension. Levels and functioning of titin have been shown to be affected by cardiac ...damage. Due to the inherent difficulty of measuring titin levels in vivo in a clinical setting, we aimed to develop an assay that could reliably measure fragments of degraded titin in serum and potentially be used in the assessment of cardiac muscle damage.
A competitive ELISA was developed to specifically measure levels of the titin sequence 12670' NVTVEARLIK 12679', derived by the degradation of titin by matrix metalloproteinase (MMP)-12. Serum samples from 90 individuals were divided into 3 equally sized groups. One group had been diagnosed with acute myocardial infarction (AMI) while the remaining two were asymptomatic individuals either with CT-scan signs of coronary calcium (CT-plusCa) or without coronary calcium (CT-noCa).
Mean geometric levels of the titin fragment in the CT-noCa group were 506.5 ng/ml (± 43.88). The CT-plusCa group showed 50.6% higher levels of the marker 763 ng/ml (± 90.14) (P < 0.05). AMI patients showed 56.3% higher levels 792 ng/ml (± 149) (P < 0.05).
The titin-12670 fragment is present in both individuals with undiagnosed and diagnosed CVD. The statistically significant increase in level of the marker in the AMI group is indicative that this neoepitope biomarker may be a useful serological marker in AMI.
The concept of the cardiovascular continuum, introduced during the early 1990s, created a holistic view of the chain of events connecting cardiovascular-related risk factors with the progressive ...development of pathological-related tissue remodelling and ultimately, heart failure and death. Understanding of the tissue-specific changes, and new technologies developed over the last 25–30 years, enabled tissue remodelling events to be monitored in vivo and cardiovascular disease to be diagnosed more reliably than before. The tangible product of this evolution was the introduction of a number of biochemical markers such as troponin I and T, which are now commonly used in clinics to measure myocardial damage. However, biomarkers that can detect specific earlier stages of the cardiovascular continuum have yet to be generated and utilised. The majority of the existing markers are useful only in the end stages of the disease where few successful intervention options exist. Since a large number of patients experience a transient underlying developing pathology long before the signs or symptoms of cardiovascular disease become apparent, the requirement for new markers that can describe the early tissue-specific, matrix remodelling process which ultimately leads to disease is evident. This review highlights the importance of relating cardiac biochemical markers with specific time points along the cardiovascular continuum, especially during the early transient phase of pathology progression where none of the existing markers aid diagnosis.
Organ donation and transplantation remain the best and most cost-effective clinical solution for end-stage organ failure. Several agencies across the US and Europe provide legislative, regulatory, ...and humanitarian services to generate smoother applications in all transplantation processes and donor-recipient relationships. US and European statistics present nine types of grafts, with kidneys being the most transplanted organ worldwide. However, organ shortage, religion, underrepresented minority groups, difficulties in obtaining consent, lack of understanding, and general ethical concerns present challenging barriers to organ donation, reflecting the complexity of graft procurement and allocation. Breaking down these barriers to reduce the organ-supply imbalance requires an appropriate multifaceted approach. Some of the key areas include increasing the potential donor pool and consent rates, apt organ allocation, and improving organ health. Additionally, suitable policies and standardized guidelines for both donors and recipients, alongside educational initiatives, are needed to ensure patient safety and global awareness. Looking forward, novel and effective research plans and initiatives are needed if we are to avoid a colossal supply-demand gap.
•Different forms of organ donation: LOD, DCD, DBD, pDCD.•World's most transplanted organs: Kidney, Liver, Heart, Pancreas, Lung, Intestine.•Waitlist numbers and organ shortage are prevailing threats to organ transplantation.•Ethics, consent, race, religion as other barriers to organ donation.•Need for alternatives, expanded donor criteria, and new educative initiatives.
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