Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P01034 (cystatin C)
 3,397 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cystatin C, a 13 kDa-protein, is produced by most nucleated cells and is catabolized by the renal tubular cells after passing the glomerular filter. It belongs to the family 2 of the cystatin superfamily of proteins. The function of cystatin C is to regulate the activity of cysteine proteinases and cystatin C seems to be the main cysteine proteinase inhibitor of most investigated human biological fluids. Its normal level in plasma is 0.8-2.5 mg/l, in cerebrospinal fluid 4-14 mg/l and in urine 0.03-0.3 mg/l. The production rate of cystatin C is remarkably constant and its plasma concentration can therefore be used as a reliable measure of the glomerular filtration rate (GFR). Indeed, the cystatin C plasma concentration is more closely correlated to the GFR than the plasma levels of creatinine and all other investigated low molecular weight proteins, including beta 2-microglobulin and retinol binding protein. Protein HC, alias alpha 1-microglobulin, is produced by the liver as a 27 kDa-glycoprotein. It belongs to the lipocalin superfamily of hydrophobic ligand binding proteins and more than 50% of the normal plasma amount of protein HC is present as a high molecular weight HC-IgA complex carrying antibody activity. The plasma concentration of free protein HC is, in contrast to that of HC-IgA, mainly determined by the GFR. The normal values for the plasma concentrations of HC-IgA and free protein HC are 36-620 mg/l and 14-26 mg/l, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Diagnostic value of analysis of cystatin C and protein HC in biological fluids. 128 35

The utility of biomolecular interaction analysis-mass spectrometry (BIA/MS) in screening for protein-protein interactions was explored in this work. Experiments were performed in which proteins served as ligands for screening of possible interactions with other proteins from human plasma and urine. The proteins utilized were beta-2-microglobulin, cystatin C (cysC), retinol binding protein (RBP), transthyretin (TTR), alpha-1-microglobulin, C-reactive protein, transferrin and papain. The immobilization of functionally active proteins was confirmed via interactions with antibodies to the corresponding proteins. Various dilutions of human urine and plasma were injected over the protein-derivatized surfaces. It was observed that the urine injections generally yielded smaller SPR responses than those observed after the plasma injections. The BIA/MS experiments did not reveal novel protein-protein interactions, although several established interactions (such as those between RBP and TTR, and cysC and papain) were validated. Few protein ligand deficiencies (such as truncations) leading to false negative and false positive BIA/MS results were also discovered.
 ...
PMID:Delineating protein-protein interactions via biomolecular interaction analysis-mass spectrometry. 1255 33

In a study performed in Tamale, in the Northern region of Ghana, cystatin C, a new and sensitive indicator of the glomerular filtration rate (GFR), was used to estimate the frequency of renal dysfunction in 78 children with uncomplicated, Plasmodium falciparum malaria. The excretion in urine of albumin, immunoglobulin G and alpha1-microglobulin was also investigated. Plasma concentrations of cystatin C were found to be elevated in 17% of the children, indicating subclinical impairment of renal function. As most (85%) of the children had glomerular as well as tubular patterns of proteinuria, it appears that both glomerulonephritis and damage to tubular cells often occur in P. falciparum malaria.
 ...
PMID:Renal dysfunction in children with uncomplicated, Plasmodium falciparum malaria in Tamale, Ghana. 1283 20

Twin-twin transfusion syndrome (TTTS) is caused by unbalanced shunting of blood between monochorionic twins. It is well known that chronic hypotension and hypovolemia may cause renal insufficiency in the donor twin. The long-term outcome of kidney function after TTTS has not previously been delineated in the literature, however. The aim of this study was to evaluate the long-term outcome of kidney function in children after intrauterine laser treatment for severe TTTS. Eighteen surviving twin pairs after intrauterine laser treatment for TTTS were involved in the study. Their gestational age at birth was 29-39 weeks, their median birth weight was 2050 g, and their median age at evaluation was 3 years 1 month, range 1 year 9 months to 4 years 5 months. Serum creatinine, cystatin C, and beta 2-microglobulin, sodium, potassium, and phosphate excretion, and urine albumin and alpha-1-microglobulin were measured. Creatinine clearance was calculated by use of the Schwartz formula. The laboratory findings for all 36 children were within normal limits. There were no significant differences between donors and recipients. Despite severe alteration of renal function before the laser treatment (anuria-polyuria) no long-term impairment of renal function could be detected in any of the 18 twin pairs.
 ...
PMID:Long-term outcome of kidney function after twin-twin transfusion syndrome treated by intrauterine laser coagulation. 1595 24

Serum BTP measurement is sometimes believed to be an alternative marker of glomerular filtration rate (GFR) assessment. The aim of the present work was to investigate the correlation between creatinine, cystatin C, and BTP values in sera and to compare the diagnostic efficacy for serum BTP and cystatin C with the glomerular filtration rate estimate. 25 individuals were tested. GFR was estimated from creatinine clearance, serum cystatin C and BTP and urine alpha-1 microglobulin, albumin, GMT and creatinine were measured. BTP values correlated with cystatin C (r = 0.75; p < 0.01), creatinine (r = 0.73, p < 0.01), GFR (r = -0.46; p = 0.02), urine alpha-1-microglobulin (r = 0.66; p < 0.01). The diagnostic efficacy of BTP for reduced GFR was insufficient and the calculation of GFR with BTP was not included in the regression model.
 ...
PMID:Assessment of serum beta-trace protein (BTP) measurement in the prediction of glomerular filtration rate. Comparison with serum cystatin C. 1693 5

This study investigates the association between serum cystatin C, serum creatinine concentrations, N-acetyl-beta-D-glucosaminidase (NAG enzymuria), urine alpha1-microglobulin (alpha1-MG) and beta2-microglobulin (beta2-MG) levels in subjects with type 2 diabetes (n=40, 20M/20F, age range 25-65 years; duration of diabetes 8-10 years) and age- and gender-matched healthy controls (n= 20). Exclusion criteria were absence of gross proteinuria, hypertension, dyslipidaemia or cardiovascular disease. Fasting blood samples and mid-stream specimen of urine (MSSU) were collected and serum creatinine, cystatin C, urine creatinine, NAG enzymuria, alpha1-MG and beta2-MG were measured. Diabetic subjects were separated into two groups based on albumin:creatinine concentration ratio. Group A: <3.5 (mg/mmol creatinine), group B: 3.5-35 (mg/mmol creatinine). While serum creatinine concentrations remained within the laboratory reference range for all groups, serum cystatin C concentration (mg/L) was significantly increased in group B (1.79 +/- 0.42 [mean +/- SD] compared to both control [0.81 +/- 0.10] and group A values [0.95 +/- 0.10]; both P<0.001). NAG enzymuria (units/mmol creatinine) was increased in both diabetic groups compared to control values (group B: 122 +/- 7, group A: 70 +/- 5, controls 27 +/- 2, all P<0.001). alpha1-microglobulin (microg/mmol creatinine) concentrations, similar in both the control group and group A diabetics at 1.10 +/- 0.10 and 1.11 +/- 0.21, respectively, were significantly elevated in group B at 2.10 +/- 0.41 (both P<0.01). Similarly, elevated beta2-MG (microg/mmol creatinine) levels were also observed in group B compared to both group A and control values (3.20 +/- 0.21 vs. 1.80 +/- 0.51 and 0.91 +/- 0.11, respectively; both P<0.001). In addition, group B levels were significantly higher than group A (P<0.001). These observations suggest that serum cystatin C is a more appropriate and effective biomarker for the overall estimation of GFR than serum creatinine values. In addition, increased serum cystatin C values were also associated with early renal tubular insult in subjects with type 2 diabetes, as characterised by increased NAG enzymuria, alpha1- and beta2-microglobulin excretion.
 ...
PMID:Serum cystatin C, enzymuria, tubular proteinuria and early renal insult in type 2 diabetes. 1791 Feb 81

Acute kidney injury (AKI), previously referred to as acute renal failure, represents a common and devastating problem in clinical medicine. Despite significant improvements in therapeutics, the mortality and morbidity associated with AKI remain high. A major reason for this is the lack of early markers for AKI, and hence an unacceptable delay in initiating therapy. Fortunately, the application of innovative technologies such as functional genomics and proteomics to human and animal models of AKI has uncovered several novel biomarkers and therapeutic targets. The most promising of these are chronicled in this review. These include the identification of biomarker panels in plasma (neutrophil gelatinase-associated lipocalin and cystatin C) and urine (neutrophil gelatinase-associated lipocalin, kidney injury molecule-1, interleukin-18, cystatin C, alpha1-microglobulin, Fetuin-A, Gro-alpha, and meprin). It is likely that the AKI panels will be useful for timing the initial insult, and assessing the duration and severity of AKI. It is also probable that the AKI panels will distinguish between the various etiologies of AKI and predict clinical outcomes. It will be important in future studies to validate the sensitivity and specificity of these biomarker panels in clinical samples from large cohorts and from multiple clinical situations. Such studies will be facilitated markedly by the development of commercial tools for the reproducible measurement of biomarkers across different laboratories.
 ...
PMID:Proteomics for biomarker discovery in acute kidney injury. 1806 46

Ischaemia/reperfusion induces systemic inflammation and oxidative stress and thereby remote organ injury in the kidney. In a double-blind, placebo-controlled clinical trial of 30 patients undergoing knee arthroplasty with tourniquet, this study evaluated the effect of N-acetylcysteine (NAC) infusion on renal function by measuring urine alpha-1-microglobulin, N-acetyl-beta-D-glucosaminidase (NAG), glutathione-S-transferase-alpha and -phi and serum creatinine and cystatin C concentrations up to 24 h post-operatively. Compared to the baseline, urine alpha-1-microglobulin/creatinine increased in both groups and was higher in the NAC group than in the placebo group at tourniquet deflation and at 3 h thereafter. Urine NAG/creatinine increased at deflation and at 3 h thereafter in the NAC group and the ratio was higher than in the placebo group. The two sensitive indicators of proximal tubular damage and function used in the present study suggest that use of NAC in clinical setting of ischaemia/reperfusion injury may increase the risk of remote kidney injury.
 ...
PMID:Potentially detrimental effects of N-acetylcysteine on renal function in knee arthroplasty. 1952 94

We evaluated renal function at a median follow-up of 18 (range 10.3-22.1) years after total body irradiation in 18 patients treated with stem-cell transplantation (SCT) (autologous SCT in 15 and allogeneic SCT in three) for hematologic malignancies and compared them with 18 healthy controls. No patient had chronic graft-versus-host disease. We found no difference in glomerular filtration rate estimated from cystatin C (105 vs 111 ml/min/1.73 m(2), p = 0.28). Patients had higher albumin excretion (0.8 vs 0.4 mg/mmol, p = 0.001), but no patient had overt albuminuria (>200 mg/L). Patients had higher diastolic blood pressure (74 vs 67 mmHg, p = 0.003). Two patients (11%) had hypertension. Patients had lower tubular reabsorption of phosphate (0.78 vs 0.91 mmol/L, p = 0.014) and higher excretion of alpha-1-microglobulin (AMG/urine creatinine, 0.4 vs 0.25 mg/mmol, p = 0.038), which correlated with time after SCT (r = 0.6, p = 0.01). We found no difference in fractional excretion (FE) of other electrolytes, amino acid excretion, or urine osmolality. We conclude that renal function was relatively well preserved at a median follow-up of 18 years after childhood SCT. The higher albumin excretion in our patients is of concern, as is the association between excretion of AMG and time after SCT, suggesting that both glomerular and tubular function may deteriorate further.
 ...
PMID:Glomerular and tubular function in young adults treated with stem-cell transplantation in childhood. 2037 2

The diagnosis and prognosis of acute kidney injury (AKI) by current clinical means is inadequate. Biomarkers of kidney injury that are easily measured and unaffected by physiological variables could revolutionize the management of AKI. Our objective was to systematically review the diagnostic and prognostic utility of urine and serum biomarkers of AKI in humans. We searched MEDLINE, PubMed and EMBASE databases (January 2000-August 2009) for biomarker studies that could be classified into the following categories: (a) confirmation of the diagnosis of established AKI, (b) early prediction of AKI, and (c) prognostication of AKI. We identified 54 manuscripts published since 2000 that met our inclusion and exclusion criteria. Urinary interleukin-18 (IL-18), kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL) and N-acetyl-beta-D-glucosaminidase (NAG) are potentially useful biomarkers for the diagnosis of established AKI. Urinary NGAL, IL-18, and liver-type fatty acid binding protein, and serum NGAL and cystatin C represent the most promising biomarkers for early prediction of AKI. Urinary cystatin C, alpha1-microglobulin, NAG and retinol-binding protein may be useful to predict severity and outcomes of AKI. In conclusion, we identified several studies of promising biomarkers for the diagnosis, prediction and prognostication of AKI. However, we note several limitations, including small sample sizes, inadequate gold standard, exclusion of patients with chronic kidney disease, incomplete statistical analyses, utilization of research-based assays and a paucity of studies examining prediction for clinical outcomes. Future studies will need to address these limitations in order for further progress to be made.
 ...
PMID:Tubular proteinuria in acute kidney injury: a critical evaluation of current status and future promise. 2051 71


1 2 Next >>