1,721,164 research outputs found
Gamma-glutammiltransferasi (GGT): biochimica clinica e patologia umana (Rassegna)
No full textγ-glutamyltransferase: clinical biochemistry and human pathophysiology. Serum γ-glutamyltransferase (GGT)
activity is a sensitive test of liver function, but its clinical use is limited by the low specificity. This paper reviews the
biochemical characteristics and physiological functions of GGT, the aspects of serum GGT measurement and the
epidemiological and biochemical evidence related to the clinical meaning of serum GGT in human pathology and the
role of membrane GGT in tumors. Epidemiological studies have shown that GGT values still within the reference
interval are positively associated with the risk of onset and evolution of atherosclerotic process and related diseases,
such as hypertension, type II diabetes, and metabolic syndrome. The relevance of the predictive value of serum GGT
has been recently increased by studies showing the association of GGT concentrations with the risk and prognosis
of cancer and renal disease. Serum GGT has also been proposed as marker of exposure to environmental
xenobiotics, which may directly induce oxidative stress
Screening for Cardiac Involvement in Carriers of Pathogenic TTR Variants: Proposal for an Approach Based on High-Sensitivity Troponin
No full text
Analisi delle citochine nella pratica clinica
No full textCytochine’s assays in clinical practice. Cytokines are a family of molecules with a fundamental role in autocrine and paracrine signaling, indeed they are fundamental in local intercommunication between cells, but they can also play an endocrine action between different tissues. Cytokines are generally discussed in the contexts of nonspecific (innate) and specific (adaptive) immune responses and inflammatory responses, but they also coordinate other biological processes. The role of cytokines in human diseases is continuously being studied, their quantification has entered current use for the evaluation of inflammatory, infectious, and autoimmune diseases. The article discusses and compares the most common and most innovative methods for the quantification of cytokines in biological fluid
Emerging Biochemical Risk Markers of Stroke
No full textStroke is a multifactorial event, resulting from the combination of genetic and environmental determinants. The first are more influent in younger patients, while the importance of the environmental factors increase with the age of patients. Biomarkers are thus needed, especially in older individuals, to define the current risk, as it results from the individual combination of genetic predisposition, environmental exposure, and clinical history.
The presence of atherosclerosis is a major cause of stroke. The well established risk factors for atherosclerosis (e.g. dyslipidaemia, hypertension, diabetes, obesity) allow the identification of patients at higher risk of vascular events, nevertheless, a large proportion of events still occur, even in patients apparently at low risk. Thus new biomarkers are needed to better identify high-risk patients, and to achieve further insights into the pathogenesis of stroke and its causative conditions.
In the first part of this chapter, inflammation, thrombosis, oxidative stress are discussed as possible source of biomarkers of plaque progression and destabilization. In the second part, serum gamma-glutamyltransferase is presented as novel marker for cardiovascular prognosis related to atherosclerosis
The expression of gamma-glutamyltransferase in cancer cells is a factor in genomic instability, progression and drug resistance.
No full text{gamma}-Glutamyltransferase (GGT), involved in metabolism of glutathione (GSH), can promote prooxidant reactions (Dominici et al, Meth Enzymol 2005) both extra- and intracellularly, resulting e.g. in activation of NF-kB (Maellaro et al, J Cell Sci 2000). Cancer cells often overexpress GGT, along with increased resistance to cisplatin. A role of GGT in cellular supply of GSH remains questionable (Pompella et al, Biochem Pharm 2006).
We have observed that:
proliferation of GGT-transfected melanoma cells is increased, both in culture and in vivo in athymic mice,
resistance to cisplatin is also increased, but
intracellular GSH levels are decreased.
Thus, drug resistance offered by GGT is likely the result of a process of "extracellular detoxication", as previously envisaged (Paolicchi et al, Eur J Cancer 2003). On the other hand, previous studies showed that GGT can effect a redox regulation of PARP activity (Del Bello et al, FASEB J 1999), likely due to some degree of (oxidative) DNA damage. In melanoma as well as in prostatic cancer cells, we observed that:
GGT-transfected cells present with higher DNA damage levels (Comet assay),
the specific inhibition of GGT restores control levels of damage, while
DNA repair systems appear unmodified.
Expression of GGT may thus represent a critical factor in acceleration of cancer progression
Facilitated vitamin C supply in melanoma cells following oxidation of extracellular ascorbic acid by membrane gamma-glutamyltransferase activity
No full textA method to obtain purified free light chain monomers and dimers from urine samples of patients with multiple myeloma
Full text linkAntibody light chains are synthesized in excess by plasma cells, and this excess can be secreted into biological fluids as dimers or monomers in various proportions. Structural differences between monomers or dimers of free light chains (FLC) can affect their biological functions and possibly their pathogenicity. They also may exhibit differential immune reactivity, perhaps explaining discrepant quantifications when measured by different immunoreagents. Having purified FLC monomers and dimers available can be useful for studying their properties. Here we propose a simple preparatory procedure to purify FLC monomers and dimers from urine samples of patients with plasma cell disorders. Two representative urine samples containing lambda or kappa FLC were loaded into a nonreducing sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE). The gel strips containing separate monomers and dimers were excised, electroeluted, and the FLC recovered. The FLC were recovered from SDS-PAGE gel in sufficient amounts to be quantified by UV and two automated nephelometric assays immunochemical. The procedure was found to be simple, reproducible, and with a high yield, thus offering the opportunity to compare different assays. Not all urine samples are suitable for this procedure, but this approach allows for the purification of FLC monomers and dimers from many selected urine samples which maintain their oligomeric organization
State of the Art of Immunoassay Methods for B-Type Natriuretic Peptides: an Update
No full textThe aim of this review article is to give an update on the state of the art of the immunoassay methods for the measurement of B-type natriuretic peptide (BNP) and its related peptides.
Using chromatographic procedures, several studies reported an increasing number of circulating peptides related to BNP in human plasma of patients with heart failure. These peptides may have reduced or even no biological activity. Furthermore, other studies have
suggested that, using immunoassays that are considered specific for BNP, the precursor of the peptide hormone, proBNP, constitutes a major portion of the peptide measured in plasma of patients with heart failure. Because BNP immunoassay methods show large (up to 50%) systematic differences in values, the use of identical decision values for all immunoassay methods, as suggested by the most recent international guidelines, seems unreasonable. Since proBNP significantly cross-reacts with all commercial immunoassay methods considered specific for BNP, manufacturers should test and clearly declare the degree of cross-reactivity of glycosylated and non-glycosylated proBNP in their BNP immunoassay methods. Clinicians should take into account that there are large systematic differences between methods when they compare results from different laboratories that use different BNP immunoassays. On the
other hand, clinical laboratories should take part in external quality assessment (EQA) programs to evaluate the bias of their method in comparison to other BNP methods. Finally, the authors believe that the development of more specific methods for the active peptide, BNP1–32, should reduce the systematic differences between methods and result in better harmonization of results
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