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Preconditioning by sevoflurane decreases biochemical markers for myocardial and renal dysfunction in coronary artery bypass graft surgery: a double-blinded, placebo-controlled, multicenter study.

BACKGROUND: Preconditioning by volatile anesthetics is a promising therapeutic strategy to render myocardial tissue resistant to perioperative ischemia. It was hypothesized that sevoflurane preconditioning would decrease postoperative release of brain natriuretic peptide, a biochemical marker for myocardial dysfunction. In addition, several variables associated with the protective effects of preconditioning were evaluated. METHODS: Seventy-two patients scheduled for coronary artery bypass graft surgery under cardioplegic arrest were randomly assigned to preconditioning during the first 10 min of complete cardiopulmonary bypass with either placebo (oxygen-air mixture only) or sevoflurane 4 vol% (2 minimum alveolar concentration). No other volatile anesthetics were administered at any time during the study. Treatment was strictly blinded to anesthesiologists, perfusionists, and surgeons. Biochemical markers of myocardial dysfunction and injury (brain natriuretic peptide, creatine kinase-MB activity, and cardiac troponin T), and renal dysfunction (cystatin C) were determined. Results of Holter electrocardiography were recorded perioperatively. Translocation of protein kinase C was assessed by immunohistochemical analysis of atrial samples. RESULTS: Sevoflurane preconditioning significantly decreased postoperative release of brain natriuretic peptide, a sensitive biochemical marker of myocardial contractile dysfunction. Pronounced protein kinase C delta and epsilon translocation was observed in sevoflurane-preconditioned myocardium. In addition, postoperative plasma cystatin C concentrations increased significantly less in sevoflurane-preconditioned patients. No differences between groups were found for perioperative ST-segment changes, arrhythmias, or creatine kinase-MB and cardiac troponin T release. CONCLUSIONS: Sevoflurane preconditioning preserves myocardial and renal function as assessed by biochemical markers in patients undergoing coronary artery bypass graft surgery under cardioplegic arrest. This study demonstrated for the first time translocation of protein kinase C isoforms delta and epsilon in human myocardium in response to sevoflurane.

Adult↗

Univerricht-Lundborg disease: underdiagnosed in the Netherlands.

PURPOSE: Univerricht-Lundborg disease (ULD), with its major symptom of action myoclonus, is supposed to be very rare in the Netherlands and western Europe. We hypothesized that the syndrome may be underdiagnosed in patients with myoclonus epilepsy. METHODS: Mutation analysis of the cystatin B gene was performed in 21 cases with uncontrolled myoclonus. RESULTS: Seven of the 21 evaluated cases carried mutations in the cystatin B gene. Diagnosis of ULD was made with a mean delay of 20 years from symptom onset. CONCLUSIONS: This study from a country without previous reports of ULD suggests that underdiagnosis of the syndrome is likely. These findings also indicate that persons with juvenile-onset myoclonus epilepsy with action myoclonus should be analyzed for ULD.

Adolescent↗

Proteinase inhibition, immunoglobulin-binding proteins and a novel antimicrobial principle.

Recent work has demonstrated that a tripeptide derivative mimicking the active proteinase-binding site of cystatin C, a human cysteine proteinase inhibitor, can block growth of group A streptococci and replication of herpes simplex virus (HSV). In the case of HSV, intact cystatin C was also found to inhibit replication of the virus. Many streptococcal strains and HSV-infected cells produce immunoglobulin (Ig)-binding proteins, and a possible connection between such proteins and proteolytic activity was indicated by the finding that bacterial Ig-binding proteins also show affinity for proteinase inhibitors. The significance of these various observations is not clear, but available data suggest that proteinases play a role in vital microbial functions (e.g. viral replication) and may be utilized as targets for antimicrobial agents. The results discussed here also indicate that peptide derivatives based on the structure of proteinase inhibitors occurring in nature could be used as such agents.

Amino Acid Sequence↗

Elongation on the amino-terminal part of stefin B decreases inhibition of cathepsin H.

Two mutants of the cysteine proteinase inhibitor, stefin B, were prepared by ligating the amino-terminal region from cystatin C and kininogen, members of two other families of cystatin superfamily. The mutant proteins were expressed in Escherichia coli and purified to homogeneity. Inhibition and kinetic constants were determined for authentic and mutated stefins against the four different cysteine proteinases, papain and human cathepsins B, L and H. Inhibition of both amino-terminal elongated stefin B mutants was decreased particularly for cathepsin H. A model of the tertiary structure of cathepsin H and its complex with stefin B was constructed. The framework for the model of cathepsin H consisted of structurally conserved regions from tertiary structures of three cysteine proteinases. Variable regions were selected from fragments of other proteins from the protein data base. We suggest that reduced binding of stefins with elongated amino termini is caused by the mini chain of cathepsin H which is probably in close proximity to the amino termini in the complexes. This mini chain is bridged to Cys214 and has already been proposed to be responsible for the aminopeptidase activity of cathepsin H. We conclude that the amino-terminal region of stefin B plays an important role in determining the strength of inhibition of cathepsin H.

Amino Acid Sequence↗

Prevalence and associations of low plasma erythropoietin in patients with Type 2 diabetes mellitus.

AIMS: Low plasma erythropoietin (EPO) is a key causal factor in the anaemia of diabetic patients. The aim of this study was to investigate the prevalence of anaemia in relation to EPO in patients with Type 2 diabetes. METHODS: In a clinic-based cross-sectional study of 161 Type 2 diabetes patients, we measured EPO, ferritin and full blood count. The patients were classified on the basis of the urine albumin:creatinine excretion ratio as normo-, micro- or macroalbuminuric. Serum creatinine, cystatin C and glomerular filtration rate (GFR) calculated from cystatin C were used as markers of renal function. All the patients were assessed for symptoms and signs of diabetic complications, including diabetic peripheral sensory neuropathy (PSN). RESULTS: Twenty-one (13.0%) patients were anaemic; 80 patients (49.7%) had low EPO (< 5 mU/ml), of whom 28.8% had a GFR < 60 ml/min per 1.73 m2; 57.5% were normoalbuminuric, 33.7% were microalbuminuric and 8.8% macroalbuminuric. Although EPO was significantly higher in anaemic patients compared with non-anaemic patients, the EPO response was inappropriate for the degree of anaemia. Of patients with PSN, 66.7% had low EPO but there was no significant difference in EPO between patients with and without PSN. Log EPO correlated significantly with urine microalbumin:creatinine ratio and logistic regression analysis showed that haemoglobin, age and urine microalbumin: creatinine ratio were the main determinants of EPO. CONCLUSIONS: The degree of microalbuminuria is the most significant determinant of plasma EPO, which is often low or inappropriately normal in diabetic patients with and without anaemia.

Aged↗

Proteomic profiling of cerebrospinal fluid identifies biomarkers for amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is characterized by degeneration of motor neurons. We tested the hypothesis that proteomic analysis will identify protein biomarkers that provide insight into disease pathogenesis and are diagnostically useful. To identify ALS specific biomarkers, we compared the proteomic profile of cerebrospinal fluid (CSF) from ALS and control subjects using surface-enhanced laser desorption/ionization-time of flight mass spectrometry (SELDI-TOF-MS). We identified 30 mass ion peaks with statistically significant (p < 0.01) differences between control and ALS subjects. Initial analysis with a rule-learning algorithm yielded biomarker panels with diagnostic predictive value as subsequently assessed using an independent set of coded test subjects. Three biomarkers were identified that are either decreased (transthyretin, cystatin C) or increased (carboxy-terminal fragment of neuroendocrine protein 7B2) in ALS CSF. We validated the SELDI-TOF-MS results for transthyretin and cystatin C by immunoblot and immunohistochemistry using commercially available antibodies. These findings identify a panel of CSF protein biomarkers for ALS.

Adult↗

Human glandular salivas: their separate collection and analysis.

Human saliva is secreted by the three pairs of major salivary glands (parotid, submandibular, and sublingual), and numerous minor ones, e.g. labial, buccal and (glosso)palatine glands. Using individually adapted collection devices, sublingual, submandibular, parotid and palatine secretions of five individuals were collected and analyzed. Electrophoretic analysis revealed that each type of saliva possesses characteristic features, despite interindividual variations. Parotid salivas are characterized by intensely staining amylase and proline-rich protein bands, but contain minute amounts of cystatins, lysozyme and the extra-parotid glycoprotein. Sublingual salivas are characterized by high concentrations of both types of salivary mucins, MG1 and MG2, and contain relatively high levels of lysozyme. Submandibular salivas contain highest concentration of salivary cystatin S. Palatine secretions contain high molecular weight mucins and a relatively high amylase concentration.

Adult↗

Measurement of renal function in patients with Fabry disease.

UNLABELLED: Appropriate measurement of the glomerular filtration rate (GFR) is important for the assessment of renal function. This paper reviews the methods used to assess GFR in clinical trials of enzyme replacement therapy (ERT) in patients with Fabry disease, which include inulin clearance, 24-hour creatinine clearance, chromium ethylene diamine tetraacetate (51Cr-EDTA) clearance and cystatin C concentrations. GFR has also been estimated using calculations based on creatinine clearance (the Cockcroft-Gault formula) and the Modification of Diet in Renal Disease (MDRD) equation. Analysis of the results of these studies shows that there are striking discrepancies between estimated and measured GFR. For example, the MDRD equation overestimates GFR in patients with Fabry disease who have normal renal function. In addition, cystatin C has been shown to be of limited use for measuring renal function during ERT, because it is influenced by other factors such as age, gender and weight. CONCLUSION: The use of exact methods, such as inulin clearance, 124I-iothalamate, 99mTc-DTPA, 51Cr-EDTA and iohexol, appears to be mandatory for a robust evaluation of the effects of ERT on GFR in patients with Fabry disease.

Adult↗

CST3 genotype associated with exudative age related macular degeneration.

AIMS: To determine whether allelic variants of the cystatin C gene CST3 are genetically associated with exudative age related macular degeneration (ARMD). Cystatin C is a cysteine protease inhibitor that regulates the activity of cathepsin S, a protease with central regulatory functions in retinal pigment epithelial cells. METHODS: CST3 of 167 patients with exudative ARMD was genotyped by using polymerase chain reaction of genomic DNA and restriction enzyme digestion with KspI and compared with those of 517 control subjects. Patients and controls were white. RESULTS: There was a significant difference in genotype counts between patients and controls (chi(2) = 7.158, df = 2; Fisher's exact test: p = 0.037). There was no significant difference in allele frequencies between patients and controls and between controls from Germany, Switzerland, Italy, and United States. The significant difference in genotype counts between patients and controls could be explained completely by an excess of the homozygous CST3 genotype B/B in patients with exudative ARMD (6.6%) over controls (2.3%), suggesting an odds ratio for ARMD in association with CST3 B/B of 2.97 (95% CI: 1.28-6.86). The results also suggest a stronger association of B/B with ARMD in males than in females. However, in both males and females there was a similar and significant effect of CST3 B/B on disease free survival assessed by Kaplan-Meier analysis. The mean disease free survival time in pooled males and females with genotypes A/A or A/B was 85 years (SE 1; 95% CI: 83-86) and 76 years (SE 2; 95% CI: 72-79) respectively in B/B homozygotes (log rank p = 0.0006). CONCLUSION: Genotyping data, the absence of a significant difference in allele frequencies between patients and controls, and survival analyses suggest an increased susceptibility for ARMD in CST3 B/B homozygotes. Therefore, CST3 B may be a recessive risk allele, significantly contributing to disease risk in up to 6.6% of German ARMD patients. Functional correlates of the allelic CST3 variants A and B remain to be investigated.

Age Factors↗

Eosinophilic bodies in pyloric and Brunner's gland cells.

A previously unreported cell phenotype occurred in the pyloric and Brunner glands in two gastrectomy specimens. The cells were characterised by homogeneous, eosinophilic material in the cytoplasm. The eosinophilic material had an abnormally strong reactivity for Cystatin C, a protein found recently in the normal secretion of pyloric and Brunner's gland cells. The reason for the apparent cytoplasmic accumulation of cystatin C in the two patients described remains unclear.

Brunner Glands↗

Meningeal derived cerebrospinal fluid proteins in different forms of dementia: is a meningopathy involved in normal pressure hydrocephalus?

OBJECTIVES: In animal models and in vitro studies leptomeninges have been shown to be the origin of neurotrophic substances that support the survival and growth of neuronal cells. Because dementia is associated with neuronal loss, we investigated whether leptomeningeal dysfunction may be involved in the pathogenesis of dementia disorders. METHODS: We analysed the cerebrospinal fluid (CSF) concentrations of the leptomeningeal derived beta trace protein, beta2 microglobulin, and cystatin C. RESULTS: There was a statistically significant difference of the CSF beta trace protein levels among different groups. Patients with idiopathic normal pressure hydrocephalus (NPH) (17.5 (SD 4.3) mg/l) showed significantly lower CSF beta trace protein levels than patients with Alzheimer's disease (23.8 (6.2) mg/l), depression (24.2 (7.3) mg/l), and normal controls (25.3 (4.9) mg/l). To patients with vascular dementia (20.1 (5.6) mg/l) and frontotemporal dementia (21.9 (7.0) mg/l), the difference was not significant. There was no significant difference regarding the CSF and serum concentrations of beta2 microglobulin or cystatin C among the different groups. CONCLUSIONS: We conclude that leptomeningeal dysfunction may be involved in certain types of dementia such as NPH and that reduced CSF beta trace protein levels in patients with NPH may aid in differentiating this difficult to diagnose disorder from other syndromes such as Alzheimer's disease.

Aged↗

Competition between albumin and low-molecular-weight proteins for renal tubular uptake in experimental nephropathies.

A controversy presently exists concerning the ability of albumin to inhibit the tubular reabsorption of low-molecular-weight (M(r)) proteins in experimental renal diseases leading to massive proteinuria. We have examined the urinary excretion of albumin and of 2 low-M(r) proteins, beta 2-microglobulin and cystatin C, in rats treated with toxins affecting primarily the glomerulus (puromycin amino-nucleoside and Adriamycin) or the tubule (mercuric chloride and maleic acid). Above a threshold of 100 mg/24 h, albuminuria induced by puromycin aminonucleoside (50 mg/kg) and Adriamycin (5 mg/kg) was associated with a marked increase in the urinary excretion of beta 2-microglobulin and cystatin C peaking at more than 100-fold the baseline levels. These glomerulotoxins did not affect the urinary excretion of the tubular enzyme N-acetyl-beta-D-glucosaminidase. This pattern of effects was completely different from that induced by mercuric chloride (2 mg/kg) and maleic acid (400 mg/kg) which increased the excretion of both N-acetyl-beta-D-glucosaminidase and low-M(r) proteins in rats with albuminuria values below 100 mg/24 h. These results strongly support the hypothesis that at high filtered loads, albumin decreases the tubular uptake of low-M(r) proteins most likely by competition for a common transport mechanism.

Acetylglucosaminidase↗

Immune reactions associated with cerebral amyloid angiopathy.

BACKGROUND AND PURPOSE: Cerebral amyloid angiopathy (CAA) occasionally coexists with cerebral vasculitis. An immune system may influence deposition or degradation of the amyloid in cerebral blood vessels. The purpose of this study was to elucidate immune reactions associated with CAA. METHODS: In 11 elderly patients with sporadic CAA, 2 patients with Icelandic familial CAA, and 2 patients with CAA and granulomatous angiitis, the cerebrovascular amyloid proteins and infiltrating inflammatory cells were analyzed immunohistochemically. RESULTS: In both sporadic CAA (beta-protein amyloid angiopathy) and Icelandic familial CAA (cystatin C amyloid angiopathy), leptomeningeal and cortical vessels were associated with an increase or activation of monocyte/macrophage lineage cells. In the cases of CAA with granulomatous angiitis, the vascular amyloid was of beta-protein and associated with infiltration of many monocyte/macrophage lineage cells, which included multinucleated giant cells containing the amyloid in the cytoplasm as well as T cells composed of CD4+ and CD8+ subsets. Amyloid P component, which was reported to be a common component of amyloid deposits and to prevent phagocytic proteolysis of amyloid fibrils of beta-protein, was negative for the vascular amyloid in a case of CAA with granulomatous angiitis but positive in the others. CONCLUSIONS: In both the beta-protein and cystatin C amyloid angiopathies, cerebrovascular amyloid deposition was associated with an increase or activation of monocyte/macrophage lineage cells. Prominent reactions of monocyte/macrophage lineage cells admixed with CD4+ and CD8+ T cells (granulomatous angiitis) were occasionally associated with beta-protein angiopathy. In some of these cases, the absence of amyloid P component might be related to pathogenesis of the granulomatous reaction.

Aged↗

Cathepsin B activity in human lung tumor cell lines: ultrastructural localization, pH sensitivity, and inhibitor status at the cellular level.

We investigated the appearance and activity of the cysteine proteinase cathepsin B and its physiological inhibitors, stefins A and B, at the cellular level in human tumor cell lines HS-24, derived from a primary lung tumor (squamous cell), and SB-3, derived from a metastasis (lung adenocarcinoma). In addition to cathepsin B, these tumor cells also expressed the immunologically and functionally related cathepsin L, but not cathepsin H. Stefin A was found in HS-24 but not in SB-3 cells; stefin B was found in both cell types. Using a specific fluorogenic cytochemical assay, the intracellular activity of the enzyme was localized and quantified. Thus, the cellular cathepsin B kinetics for the synthetic substrates Z-Arg-Arg-4M beta NA and Z-Val-Lys-Lys-Arg-4M beta NA, its pH dependence and inhibition by E64, stefins A and B, and cystatin C could be determined. From these measurements it appeared that the enzyme exhibited different cleavage rates for these substrates in the different cell types, showed considerable cleavage activity at neutral pH, which was stable under these conditions for extended time periods, and was highly sensitive to the inhibitors E64 and cystatin C but was considerably less sensitive to stefins, particularly stefin A. By conventional light microscopy, confocal laser scanning microscopy, and electron microscopy the enzymatic activity was localized in lysosomes, as expected, but also in the endoplasmic reticulum, nuclear membrane, and plasma membrane. The endoplasmic reticulum is a site at which only pre-mature enzyme forms exist, which are usually not active. The appearance of enzymatic activity at the plasma membrane confirms earlier biochemical and immunofluorescence microscopic investigations. The different sites of localization within the cells make it likely that different forms of the enzyme are expressed simultaneously, which follow alternate ways of processing and sorting. Taken together, the results support an involvement of the enzyme under extracellular conditions in degradative processes.

Amino Acid Sequence↗

Renal dysfunction in children with uncomplicated, Plasmodium falciparum malaria in Tamale, Ghana.

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.

Acute Kidney Injury↗

Identification of target genes and a unique cis element regulated by IRF-8 in developing macrophages.

Interferon regulatory factor-8 (IRF-8)/interferon consensus sequence-binding protein (ICSBP) is a transcription factor that controls myeloid-cell development. Microarray gene expression analysis of Irf-8-/- myeloid progenitor cells expressing an IRF-8/estrogen receptor chimera (which differentiate into macrophages after addition of estradiol) was used to identify 69 genes altered by IRF-8 during early differentiation (62 up-regulated and 7 down-regulated). Among them, 4 lysosomal/endosomal enzyme-related genes (cystatin C, cathepsin C, lysozyme, and prosaposin) did not require de novo protein synthesis for induction, suggesting that they were direct targets of IRF-8. We developed a reporter assay system employing a self-inactivating retrovirus and analyzed the cystatin C and cathepsin C promoters. We found that a unique cis element mediates IRF-8-induced activation of both promoters. Similar elements were also found in other IRF-8 target genes with a consensus sequence (GAAANN[N]GGAA) comprising a core IRF-binding motif and an Ets-binding motif; this sequence is similar but distinct from the previously reported Ets/IRF composite element. Chromatin immunoprecipitation assays demonstrated that IRF-8 and the PU.1 Ets transcription factor bind to this element in vivo. Collectively, these data indicate that IRF-8 stimulates transcription of target genes through a novel cis element to specify macrophage differentiation.

Animals↗

Tumor transcriptome reveals the predictive and prognostic impact of lysosomal protease inhibitors in non-small-cell lung cancer.

PURPOSE: Insight into clinical response to platinum-based chemotherapy (PBC) in non-small-cell lung cancer (NSCLC). METHODS: Matched tumor and nontumor lung tissues from PBC-treated NSCLC patients (four nonresponders and four responders) and tumor tissue from an independent test set (four nonresponders and four responders), were profiled using microarrays. Lysosomal protease inhibitors SerpinB3 and cystatin C were highly correlated with clinical response and were further evaluated by immunohistochemistry in PBC-treated patients (36 prechemotherapy and 13 postchemotherapy). Investigation of the pathogenic and prognostic significance of SerpinB3 was performed in 251 primary tumors, with 64 regional lymph node pairs, from chemotherapy-naïve NSCLC patients using immunohistochemistry. RESULTS: Bioinformatic analyses of gene expression in the training set identified a gene set (n = 17) that separated all patients in the training and test sets (n = 16) according to response in hierarchical clustering. Transcriptome profiling revealed that SerpinB3 mRNA was highly correlated with degree of response (r = -0.978; P < .0001) and was a clear outlier (nonresponders:responders > 50-fold). SerpinB3 protein expression was correlated with clinical response in PBC-treated NSCLC patients (P = .045). Expression of SerpinB3 and cystatin C, relative to the target, protease cathepsin B, was independently predictive of response (odds ratio, 17.8; 95% CI, 2.0 to 162.4; P = .01), with an accuracy of 72%. High SerpinB3 expression levels, invariably associated with chemoresistance, had contrasting prognostic impact in untreated squamous cell carcinomas (hazard ratio [HR], 0.43; 95% CI, 0.18 to 0.93) or adenocarcinomas (HR, 2.09; 95% CI, 1.03 to 4.72). CONCLUSION: This provides the first comprehensive molecular characterization of clinical responsiveness to PBC in NSCLC and reveals the predictive and prognostic impact of two lysosomal protease inhibitors, potentially representing novel targets for NSCLC therapeutics.

Aged↗

Unverricht-Lundborg disease in a five-generation Arab family: instability of dodecamer repeats.

BACKGROUND: Unverricht-Lundborg disease (ULD) is the prototypical form of progressive myoclonus epilepsy, and subjects are usually very photosensitive. ULD is caused by mutations in the cystatin B (CSTB) gene; the most common mutation is expansion of a dodecamer repeat near the promoter. The authors studied a five-generation Arab family with ULD lacking photosensitivity. METHODS: An Arab family from the Galilee region of Israel with progressive myoclonus epilepsy was clinically evaluated. Blood samples were obtained from three living affected and 16 unaffected individuals. Expansion of dodecamer repeat in the CSTB gene was examined. RESULTS: The three living affected individuals showed spontaneous and action myoclonus, ataxia, and mild dementia. EEG in two individuals showed generalized polyspike-wave without photosensitivity. The family structure with large sibships and multiple consanguineous loops allowed the authors to examine the gene over four generations of adults. The three living affected individuals were homozygous for repeat expansions and 11 of the 16 unaffected family members were heterozygous. Instability was demonstrated by the presence of expansions of different sizes occurring on the same haplotype background in this inbred family. Fragment size variations could be unequivocally detected in two sibships. The expansions were in the 49 to 54 dodecamer repeat range. Changes in one generation were small, 1 to 4 repeat units, consisting of either enlargements or contractions. CONCLUSIONS: Instability of the expanded dodecamer repeats in the cystatin B gene is frequent. Almost invariably, a small change is observed in parent-child transmission. The lack of photosensitivity in this family is unexplained.

Adult↗