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Nelson C, Constable PD, Connolly SL. Comparison of selected serum biochemistry measurements between the Nova Prime Plus VET, Nova pHOx Ultra, and Beckman Coulter AU680 analyzers in dogs. Vet Clin Pathol 2021; 50:327-341. [PMID: 34545580 DOI: 10.1111/vcp.13010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 02/07/2021] [Accepted: 02/27/2021] [Indexed: 12/01/2022]
Abstract
BACKGROUND Blood gas chemistry analyzers typically produce results faster and use smaller sample volumes than reference chemistry analyzers. However, results may not be comparable between blood gas chemistry analyzers and reference chemistry analyzers or between different models of blood gas chemistry analyzers. This could suggest the use of separate reference intervals and, thus, has implications when making clinical decisions. OBJECTIVE We aimed to perform method comparison studies to evaluate selected canine serum biochemical values obtained using the Nova Stat Profile Prime Plus VET (Prime Plus VET), Stat Profile Nova pHOx Ultra (Ultra), and Beckman Coulter AU680 (Beckman) analyzers. We hypothesized that the three analyzers would be identical within inherent imprecision. METHODS Jugular venous blood samples were collected from 103 endurance-trained sled dogs, and serum was harvested and stored for analysis. Results for serum chloride, potassium, sodium, creatinine, and urea nitrogen concentrations obtained from the Prime Plus VET and Ultra analyzers were compared with results from the Beckman analyzer, which was considered to be a reference method. Results for serum chloride, potassium, sodium, creatinine, urea nitrogen, and L-lactate concentrations obtained from the Prime Plus VET and Ultra analyzers were compared. Passing-Bablok regression and Bland-Altman plots were used for method comparison. RESULTS Significant (P < 0.05) constant or proportional bias was found for many analytes for all three method comparison studies. CONCLUSIONS Due to the presence of statistically significant differences between all three analyzers that may be clinically relevant, it is recommended that reference intervals be created for new blood gas analyzers, even when similar methodologies are used.
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Affiliation(s)
- Courtney Nelson
- Department of Pathobiology, College of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, USA
| | - Peter D Constable
- Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Urbana, IL, USA
| | - Sara L Connolly
- Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Urbana, IL, USA
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Heineken F, Brady-Smith M, Haynie J, Van Stone J. Prescribing Dialysate Bicarbonate Concentrations for Hemodialysis Patients. Int J Artif Organs 2018. [DOI: 10.1177/039139888801100111] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
A rearranged equation of Sargent and Gotch (1) was used to determine dialysate bicarbonate concentrations for hemodialysis patients. Parameters in this equation include an estimate of the acid generated by each patient between treatments, an estimate for the dialyzer dialysance for bicarbonate, ultrafiltration rate, blood flow rate and a targeted mid-dialysis plasma bicarbonate concentration of 25 mEq/L. Nine patients were studied over a 35 week period to verify this method of determining each patient's dialysate bicarbonate concentration. Prescribed dialysate bicarbonate concentrations for the nine patients varied from 29 to 38 mEq/L with five patients having a prescribed value of 35 mEq/L. After a baseline period of five weeks, five patients switched from a 37 mEq/L acetate dialysate to their prescribed dialysate bicarbonate concentration. Four patients who had already been on bicarbonate dialysis at a concentration of 35 mEq/L were dialyzed with their prescribed dialysate bicarbonate concentrations. Patients were then followed for a study period of 30 weeks. The prescribed dialysate bicarbonate concentration resulted in more normal acid/base chemistries for both groups of patients. The results also demonstrate that chronic hemodialysis patients require individualization of dialysate bicarbonate concentrations.
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Affiliation(s)
- F.G. Heineken
- Research and Development, Medical Systems Division, COBE Laboratories, Inc. Lakewood, Colorado
- Department of Medicine, School of Medicine, University of Missouri, Columbia, Missouri, U.S.A
| | - M. Brady-Smith
- Research and Development, Medical Systems Division, COBE Laboratories, Inc. Lakewood, Colorado
- Department of Medicine, School of Medicine, University of Missouri, Columbia, Missouri, U.S.A
| | - J. Haynie
- Research and Development, Medical Systems Division, COBE Laboratories, Inc. Lakewood, Colorado
- Department of Medicine, School of Medicine, University of Missouri, Columbia, Missouri, U.S.A
| | - J.C. Van Stone
- Research and Development, Medical Systems Division, COBE Laboratories, Inc. Lakewood, Colorado
- Department of Medicine, School of Medicine, University of Missouri, Columbia, Missouri, U.S.A
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Govindan M, Karunakaran K, Nallasamy P, Moon IS. Effective identification of (NH4)2CO3 and NH4HCO3 concentrations in NaHCO3 regeneration process from desulfurized waste. Talanta 2015; 132:327-33. [DOI: 10.1016/j.talanta.2014.08.044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Revised: 08/13/2014] [Accepted: 08/14/2014] [Indexed: 10/24/2022]
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Uemura O, Nagai T, Ishikura K, Ito S, Hataya H, Gotoh Y, Fujita N, Akioka Y, Kaneko T, Honda M. Cystatin C-based equation for estimating glomerular filtration rate in Japanese children and adolescents. Clin Exp Nephrol 2013; 18:718-25. [PMID: 24253614 DOI: 10.1007/s10157-013-0910-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Accepted: 10/31/2013] [Indexed: 11/26/2022]
Abstract
BACKGROUND Renal inulin clearance is the gold standard for evaluation of kidney function, but is compromised by problems of collecting urine samples in children, especially those <6 years or with a bladder dysfunction. Therefore, we should utilize the serum cystatin C (cysC)-based estimated glomerular filtration rate (eGFR) for measuring serum cysC. The purpose of the present study is to determine the applicability of the new serum cysC-based eGFR in Japanese children and adolescents, including infants with chronic kidney disease (CKD), for evaluation of renal function. METHODS Inulin clearance and standardized serum cysC level determined by the colloidal gold immunoassay were measured in 135 pediatric CKD patients between the ages of 1 month and 18 years with no underlying disease that affects renal function except CKD, to determine serum cysC-based eGFR in Japanese children and adolescents. RESULTS We showed the inulin clearance by expression of 1/serum cysC in pediatric CKD patients, which resulted in the equation: inulin GFR (mL/min/1.73 m(2)) = 104.1 × 1/serum cysC (mg/L) - 7.80. We also validated the cysC-based eGFR formula for Japanese adults. eGFR values obtained with the adult formula significantly underestimated GFR by approximately 8 % in children with CKD. CONCLUSION We determined the new cysC-based eGFR formula is useful for clinical screening of renal function in Japanese children and adolescents, including infants.
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Affiliation(s)
- Osamu Uemura
- The Japanese Society for Pediatric Nephrology, the Committee of Measures for Pediatric CKD, Tokyo, Japan,
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Reference ranges for serum cystatin C measurements in Japanese children by using 4 automated assays. Clin Exp Nephrol 2013; 17:872-6. [PMID: 23446519 DOI: 10.1007/s10157-013-0784-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Accepted: 02/06/2013] [Indexed: 10/27/2022]
Abstract
OBJECTIVE The data available on reference ranges for cystatin C in children are limited, and there are discrepancies among the available data. The aim of this study was to describe the reference ranges for cystatin C in Japanese children by using 4 automated assays. METHODS Serum cystatin C levels were measured in 1128 Japanese children aged 3 month to 16 years without kidney disease. We calculated age-, gender-, race- and assay-specific cystatin C ranges. RESULTS For all 4 assays, the median serum cystatin C levels were raised in term infants compared with older children and decreased by the first 2 years. The median serum cystatin C levels remained constant throughout up to the age of 14 years and decreased in children aged 15-16 years. The median serum cystatin C levels in children aged 12-16 years were slightly higher in males than in females. Assay-specific differences were also observed in the levels of serum cystatin C measured. CONCLUSION Age-, gender-, race- and assay-specific ranges for serum cystatin C should be used as another tool to assess kidney function in children.
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Abrahamson M. Molecular basis for amyloidosis related to hereditary brain hemorrhage. Scandinavian Journal of Clinical and Laboratory Investigation 2010. [DOI: 10.1080/00365519609168298] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Dimeski G, Badrick T, John AS. Ion Selective Electrodes (ISEs) and interferences--a review. Clin Chim Acta 2009; 411:309-17. [PMID: 20004654 DOI: 10.1016/j.cca.2009.12.005] [Citation(s) in RCA: 127] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Revised: 11/25/2009] [Accepted: 12/04/2009] [Indexed: 11/29/2022]
Abstract
Ion Selective Electrodes (ISEs) are used to measure some of the most critical analytes on clinical laboratory and point-of-care analysers. These analytes which include Na(+), K(+), Cl(-), Ca(2+), Mg(2+) and Li(+) are used for rapid patient care decisions. Although the electrodes are very selective, they are not free of interferences. It is important for laboratories to have an understanding of the type and extent of interferences in order to avoid incorrect clinical decisions and treatment.
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Affiliation(s)
- Goce Dimeski
- Department of Chemical Pathology, Pathology Queensland, Princess Alexandra Hospital, Brisbane, 4102, Australia.
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Al-Tonbary YA, Hammad AM, Zaghloul HM, El-Sayed HE, Abu-Hashem E. Pretreatment cystatin C in children with malignancy: can it predict chemotherapy-induced glomerular filtration rate reduction during the induction phase? J Pediatr Hematol Oncol 2004; 26:336-41. [PMID: 15167345 DOI: 10.1097/00043426-200406000-00002] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND Monitoring of kidney function is essential during chemotherapy. Serum creatinine is of limited value in early detection of renal insufficiency. The cystatin C level has been proved to be a good marker for detection of mild reduction in glomerular filtration rate. PURPOSE To evaluate the validity of the pretreatment serum cystatin C level in predicting significant reduction of the glomerular filtration rate during the induction phase of chemotherapy. PATIENTS AND METHODS Serum levels of cystatin C and creatinine and corrected creatinine clearance were assessed in 34 children with different types of malignancy just before the start of chemotherapy and again in 33 of them 1 month later. Patients were compared with 14 healthy controls of matched age and sex. RESULTS Before chemotherapy, all patients when compared with controls had normal levels of cystatin C (P = 0.1) and creatinine (P = 0.62) and normal corrected creatinine clearance (P = 0.76). One month after chemotherapy, patients showed a significant increase in their cystatin C levels (P < 0.001) and a significant decrease in their corrected creatinine clearance (P < 0.001). However, creatinine levels did not change significantly (P = 0.65). Corrected creatinine clearance negatively correlated significantly with both cystatin C and creatinine levels (r = -0.622, P < 0.001; r = -0.346, P = 0.045, respectively) before chemotherapy and also 1 month after chemotherapy (r = -0.577, P < 0.001; r = -0.45, P = 0.009, respectively). When pretreatment levels of cystatin C and creatinine were used to predict patients who developed a reduction in corrected creatinine clearance of more than 20% after therapy, only the cystatin C level was statistically significant (P = 0.03). A cutoff point of 0.57 mg/L with sensitivity of 77.8%, specificity of 63%, and overall accuracy of 74% was suggested. CONCLUSIONS Children with malignant diseases develop significant reduction in their glomerular filtration rate during the induction phase of chemotherapy, although their serum creatinine level may not change significantly. Cystatin C, as a more sensitive marker than creatinine for the assessment of glomerular filtration rate, can be used to predict patients who would have a higher risk of renal impairment during the induction phase of chemotherapy and who thus would require more frequent renal function assessment to consider adjustment of the chemotherapy dose if indicated.
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Totu E, Josceanu AM, Covington AK. Improved potassium-selective membrane using valinomycin as ionophore for ion-selective microdevices. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2001. [DOI: 10.1016/s0928-4931(01)00374-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Bjarnadottir M, Nilsson C, Lindström V, Westman A, Davidsson P, Thormodsson F, Blöndal H, Gudmundsson G, Grubb A. The cerebral hemorrhage-producing cystatin C variant (L68Q) in extracellular fluids. Amyloid 2001; 8:1-10. [PMID: 11293820 DOI: 10.3109/13506120108993809] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
A variant of the normal extracellular cysteine protease inhibitor cystatin C (L68Q-cystatin C), is the amyloid precursor in hereditary cystatin C amyloid angiopathy (HCCAA). It has been suggested that the mutation causes cellular entrapment of L68Q-cystatin C in vivo and that the variant protein is not secreted to extracellular fluids. In order to test this hypothesis, we used matrix-assisted laser desorption ionization time-of-flight mass spectrometry in an effort to demonstrate the presence of L68Q- along with wildtype cystatin C in plasma and cerebrospinal fluid (CSF) of HCCAA-patients. Plasma from all five investigated HCCAA-patients contained both L68Q- and wildtype cystatin C. The presence of approximately equal amounts of cystatin C dimers and monomers was demonstrated in plasma from HCCAA-patients, whereas only monomers could be found in normal plasma. L68Q-wildtype-cystatin C heterodimers seem to be present in the dimeric cystatin C population. CSF from six HCCAA-patients also contained cystatin C-dimers and monomers, but the dimeric fraction was minute. CSF from control patients did not contain dimeric cystatin C. These results suggest that the milieu of L68Q-cystatin C is important for its stability and dimerization status and that certain milieus might hinder its further development into oligomers, amyloid fibrils and other precipitating aggregates.
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Affiliation(s)
- M Bjarnadottir
- Department of Clinical Chemistry, Institute of Laboratory Medicine, University of Lund, University Hospital, Sweden
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IFCC Reference Measurement Procedure for Substance Concentration Determination of Total Carbon Dioxide in Blood, Plasma or Serum. Clin Chem Lab Med 2001; 39:283-8. [PMID: 11350028 DOI: 10.1515/cclm.2001.39.3.283] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
A reference measurement procedure for substance concentration determination of total CO2 in blood, plasma (the anticoagulant is usually heparin) or serum is described. The document covers the principle of the method, the materials and equipment needed and essential aspects of the procedure. The substance concentration of total CO2 in blood, plasma or serum is accurately determined and therefore this procedure is recommended for assigning reference values to reference materials and for blood gas quality assurance in laboratories and by manufacturers of blood gas equipment.
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Randers E, Krue S, Erlandsen EJ, Danielsen H, Hansen LG. Reference Interval for Serum Cystatin C in Children. Clin Chem 1999. [DOI: 10.1093/clinchem/45.10.1856] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Bökenkamp A, Domanetzki M, Zinck R, Schumann G, Byrd D, Brodehl J. Cystatin C Serum Concentrations Underestimate Glomerular Filtration Rate in Renal Transplant Recipients. Clin Chem 1999. [DOI: 10.1093/clinchem/45.10.1866] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
| | | | - Raymund Zinck
- Department of Clinical Chemistry I, Hannover Medical School, D-30623 Hannover, Germany
| | - Gerhard Schumann
- Department of Clinical Chemistry I, Hannover Medical School, D-30623 Hannover, Germany
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Randers E, Erlandsen EJ. Serum cystatin C as an endogenous marker of the renal function--a review. Clin Chem Lab Med 1999; 37:389-95. [PMID: 10369108 DOI: 10.1515/cclm.1999.064] [Citation(s) in RCA: 214] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Since 1985, cystatin C has been suggested to be a marker of the renal function. Cystatin C is a proteinase inhibitor with a low molecular weight (M(r) = 13359). It is produced at a constant rate in all nucleated cells investigated to date, freely filtered in the renal glomeruli and reabsorbed and catabolised in the proximal tubules. The concentration of serum cystatin C is mainly determined by glomerular filtration, which makes cystatin C an endogenous marker of glomerular filtration rate (GFR). There are few data describing the influence of various factors on the production and elimination of cystatin C. Fully automated assays using particle-enhanced turbidimetry or particle-enhanced nephelometry are available and the assays are precise, rapid and usable in clinical routine practice. Reference intervals have been determined for cystatin C in adults and in children older than one year. It has been suggested that the same reference interval can be used in children older than one year and in adults without gender differences, on the assumption that the same method with the same standardisation is used. Several studies including adults and children with different renal diseases with various kidney function have suggested serum cystatin C to be a better marker of GFR than serum creatinine.
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Affiliation(s)
- E Randers
- Department of Internal Medicine, Viborg Hospital, Denmark.
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Mussap M, Ruzzante N, Varagnolo M, Plebani M. Quantitative automated particle-enhanced immunonephelometric assay for the routinary measurement of human cystatin C. Clin Chem Lab Med 1998; 36:859-65. [PMID: 9877092 DOI: 10.1515/cclm.1998.151] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Human cystatin C is a low molecular mass protein of 13359 Dalton recently proposed as a new very sensitive marker of changes in glomerular filtration rate. Serum cystatin C concentration correlates negatively with glomerular filtration rate as well as or better than creatinine. We evaluated a recently introduced automated nephelometric immunoassay for cystatin C in serum or EDTA-plasma samples on the Behring Nephelometer System. The assay consists of incubating the 100-fold diluted sample for 6 minutes with latex particles covalently coated with anti-human cystatin C antibodies, and then quantifying the change of light-scatter produced. Method reproducibility is satisfactory, the intra- and inter-assay coefficients of variation ranging from 1.58% to 3.77% and from 5.6% to 11.47% respectively. Rheumatoid factor (< or = 1116 IU/ml), bilirubin (< or = 418 micrommol/l), triglycerides (10.47 mmol/), and haemoglobin (12 g/l) do not significantly interfere in the assay. No significant difference was found in cystatin C concentration between serum and EDTA-plasma samples. Cystatin C is stable in serum samples stored under different conditions up to one month. This method correlates well (mean difference=-0.536+/-0.307 mg/l) with another commercially available particle-enhanced turbidimetric immunoassay. Cystatin C offers better clinical sensitivity than creatinine for discriminating patients with normal renal function and those with mild-to-moderate reduction in renal function. This method is suitable for routine cystatin C measurement, including emergencies.
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Affiliation(s)
- M Mussap
- Department of Laboratory Medicine, University-Hospital of Padova, Italy
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Bühlmann P, Pretsch E, Bakker E. Carrier-Based Ion-Selective Electrodes and Bulk Optodes. 2. Ionophores for Potentiometric and Optical Sensors. Chem Rev 1998; 98:1593-1688. [PMID: 11848943 DOI: 10.1021/cr970113+] [Citation(s) in RCA: 1272] [Impact Index Per Article: 48.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Philippe Bühlmann
- Department of Chemistry, School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan, Department of Organic Chemistry, Swiss Federal Institute of Technology (ETH), Universitätstrasse 16, CH-8092 Zürich, Switzerland, and Department of Chemistry, Auburn University, Auburn, Alabama 36849
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Immunohistochemical Detection of Neuroendocrine Markers in Tumors of the Lungs and Gastrointestinal Tract. ACTA ACUST UNITED AC 1998. [DOI: 10.1097/00022744-199812000-00001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Jacobsson B, Lignelid H, Bergerheim US. Transthyretin and cystatin C are catabolized in proximal tubular epithelial cells and the proteins are not useful as markers for renal cell carcinomas. Histopathology 1995; 26:559-64. [PMID: 7665147 DOI: 10.1111/j.1365-2559.1995.tb00275.x] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Ten human kidney specimens and thirty-two renal cell carcinomas were investigated for the presence of transthyretin mRNA and cystatin C mRNA using Northern blot analysis. Five of ten kidney specimens and 15 of 32 renal carcinomas were also immunohistochemically investigated for the presence of the corresponding proteins. Transthyretin mRNA could not be detected in any of the normal or neoplastic tissue preparations, whereas low amounts of cystatin C mRNA were found in nine of ten normal kidneys and in 24 of 32 renal cell carcinomas. Immunoreactive transthyretin and cystatin C were present in proximal tubular epithelial cells of all kidney specimens, whereas neither of the proteins was detected the tumour cells of the renal carcinomas. Immunoreactive cystatin C was, however, demonstrated in scattered monocyte/macrophage-like cells. We conclude that the presence of immunoreactive transthyretin and cystatin C in proximal tubular cells of the kidney is most likely due to reabsorption of the proteins from the primary urine. The small amounts of cystatin C mRNA in some of the normal and neoplastic renal preparations are probably due to cystatin C synthesis in macrophages. Transthyretin has been recommended as an immunohistochemical marker for renal cell carcinomas. Our results, however, clearly indicate that neither transthyretin nor cystatin C constitutes a useful marker for such neoplasms.
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Affiliation(s)
- B Jacobsson
- Department of Clinical Chemistry and Pathology, Danderyd Hospital, Sweden
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20
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IFCC Section. Clin Chem Lab Med 1995. [DOI: 10.1515/cclm.1995.33.6.399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Barka T, van der Noen H. Expression of the cysteine proteinase inhibitor cystatin C mRNA in rat eye. Anat Rec (Hoboken) 1994; 239:343-8. [PMID: 7943765 DOI: 10.1002/ar.1092390312] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND Cystatin C, a naturally occurring inhibitor of cysteine proteinases, belongs to family 2 of the cystatin superfamily. While cystatins in general, and cystatin C specifically, are expressed in various cell types and found in biological fluids, cystatins in ocular structures have not been investigated. In the present study, the expression of cystatin C mRNA in the eye of the rat was studied. METHODS Total RNA was extracted from eyes as well as from pooled corneae, retinas, lenses, sclerae, and corneae of adult rats. Cystatin C mRNA was detected in the RNA samples by reverse transcriptase--polymerase chain reaction and Northern blot hybridization. In addition, in situ hybridizations of formalin-fixed cryostat sections were carried out using a digoxigenin-labeled cystatin C probe. RESULTS Cystatin C mRNA was demonstrated in total RNAs extracted from the eye, sclera, and retina, but not in RNAs isolated from the cornea and lens. In situ hybridizations revealed cystatin C mRNA in most of the stromal cells of the sclera. In the retina, a strong signal was localized in the outer nuclear layer. The distribution of the reaction product suggested that in the retina Müller cells and rod cells are the primary sites of expression of cystatin C. In addition, some glial cells in the inner nuclear and ganglion cell layers were stained. No specific signal for cystatin C mRNA was detected in the cornea, lens, iris, ciliary body, and choroid. CONCLUSIONS In the eye of the rat, significant levels of cystatin C mRNA are detected in the sclera and retina. In the sclera cystatin C may play a role in modulating the activities of cysteine proteinases, mostly cathepsins, involved in the turnover and remodeling of the stroma. In the retina, cystatins synthesized and presumably released by Müller cells and rod cells may have a protective function against the harmful effects of cysteine proteinases released under physiologic and pathologic conditions.
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Affiliation(s)
- T Barka
- Department of Cell Biology and Anatomy, Mount Sinai School of Medicine, City University of New York, NY 10029
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Uldall A, Blaabjerg O, Elfving S, Elg P, Gerhardt W, Holmberg H, Hørder M, Icén A, Juva K, Jørgensen PJ. A programme for assigning target values for external quality assessment schemes in countries with no authorized reference laboratories. Annex. Experiences with deviating results on Ektachem 700 XR. Scand J Clin Lab Invest Suppl 1993; 212:31-7. [PMID: 8465150 DOI: 10.3109/00365519309085452] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The use of consensus values in external quality assessment schemes (EQAS) involves several problems and should preferably be replaced with target values obtained by methods of high metrological level. However, such values are difficult to obtain. In the present study we transferred values from the NIST (former NBS) certified reference serum SRM 909 to lyophilized and frozen test sera for various inorganic components using flame absorption or flame emission spectrometry. Enzyme values were assigned by laboratories of members of the former Scandinavian Enzyme Committee. The assignment was based on 2-4 determinations each day through 3 days of experiment. A total of 10 laboratories participated in the work. The results were utilized in a Danish EQAS. One practical concern is the fairly long time (9 months) which was needed for production, collection and compiling all data. To get an impression of how much dry chemistry analysers, e.g, could influence consensus values a Kodak Ektachem 700 XR was studied using lyophilized and frozen sera. The results are reported in the annex. On NIST SRM 909 the values found for sodium(I) were 6% too high even though the findings on frozen human sera were accurate. For aspartate aminotransferase a result three times the target values was found on a human lyophilized serum, while the values on the frozen sera only were slightly too high.
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Affiliation(s)
- A Uldall
- Department of Clinical Chemistry, Herlev University Hospital, Denmark
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Affiliation(s)
- D R Jacobson
- Medical Service, New York Veterans Affairs Medical Center, New York
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Conroy CW, Maren TH. The permeability of hydrophobic membranes to 22Na salts and 14CO2 in low dielectric media. Biophys Chem 1989; 34:177-84. [PMID: 2560406 DOI: 10.1016/0301-4622(89)80056-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The one-way fluxes of 14CO2 and a series of 22Na (Cl, Br, HCO3, ClO4, I) salts across n-hexadecane-impregnated solid-support liquid membranes have been measured in water and low dielectric media (50-90 vol% dioxane/water). One-way fluxes for 14CO2 (J14CO2) were 0.84 and 1.03 x 10(-9) mol cm-2 s-1 in 75% dioxane (aq.) and water, respectively, across both impregnated cellulose and teflon membranes. 22Na fluxes across impregnated cellulose membranes in 75% dioxane (aq.) ranged from 1.8 to 11.4 x 10(-10) mol cm-2 s-1 and had the order NaCl less than NaBr less than NaHCO3 less than NaClO4 less than Nal. 22Na fluxes across impregnated teflon membranes were slightly smaller, 1.5-7.1 x 10(-10) mol cm-2 s-1, but had the same order for the anions tested. No measurable 22Na fluxes were observed in aqueous media. For NaI and NaClO4 there was a 3-6-fold enhancement of fluxes in 90% dioxane (aq.) compared to 75% dioxane (aq.). The corresponding enhancement for fluxes of NaHCO3, NaBr and NaCl was 1.5-fold. The results are discussed in terms of ion-paired salt transport in low dielectric media.
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Affiliation(s)
- C W Conroy
- Department of Pharmacology and Therapeutics, University of Florida College of Medicine, Gainesville 32610
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Siggaard-Andersen O, Wimberley PD, Fogh-Andersen N, Gøthgen IH. Measured and derived quantities with modern pH and blood gas equipment: Calculation algorithms with 54 equations. Scandinavian Journal of Clinical and Laboratory Investigation 1988. [DOI: 10.1080/00365518809168181] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Abstract
There are many genetic disorders associated with an increased risk for stroke that may easily be overlooked in the evaluation of both adult and pediatric acute stroke victims. The recognition of a genetic disorder as the cause of a stroke has important implications not only for the immediate care of the stroke victim, but often also for others in the patient's family who may be at risk for the same disease and for whom preventive measures sometimes can be taken. We present here a comprehensive review of genetic disorders associated with stroke in the nongeriatric age groups for which a causative role in the evolution of stroke has been recognized or is likely. For each disorder, the major clinical and biochemical characteristics as well as the probable pathogenetic mechanisms of stroke are discussed, together with the appropriate testing required to screen for and confirm the diagnosis. The great variety of genetic disorders and mechanisms causing stroke underscores the increasing importance of understanding genetic disease for appropriate diagnosis and treatment of a common clinical problem affecting both children and adults.
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Affiliation(s)
- M Natowicz
- Division of Genetics, Children's Hospital of Philadelphia, PA 19104
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Abrahamson M, Grubb A, Olafsson I, Lundwall A. Molecular cloning and sequence analysis of cDNA coding for the precursor of the human cysteine proteinase inhibitor cystatin C. FEBS Lett 1987; 216:229-33. [PMID: 3495457 DOI: 10.1016/0014-5793(87)80695-6] [Citation(s) in RCA: 144] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Recombinant cystatin C producing clones were isolated from a human placenta lambda gt11 cDNA library. The cDNA insert of one of the clones, containing 777 base pairs, encodes the complete mature cystatin C (120 amino acids) and a hydrophobic leader sequence of 26 amino acids, indicating an extracellular function of the inhibitor. The deduced protein sequence confirms the protein sequence of cystatin C isolated from human urine, but differs in one position from the sequence of the cystatin C fragment deposited as amyloid in hereditary cerebral hemorrhage with amyloidosis.
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