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1.
Palliat Support Care ; 17(1): 21-28, 2019 02.
Article in English | MEDLINE | ID: mdl-30600794

ABSTRACT

OBJECTIVE: Meaning and Purpose (MaP) therapy aims to enhance meaning-based coping through a life review that focuses on the value and worth of the person, key relationships, sources of fulfillment, roles, and future priorities in living life out fully. We sought to test the feasibility and acceptability of a six-session model of MaP therapy against a wait-list control cohort in a pilot study seeking effect sizes on measures of adaptation. METHOD: We randomized patients with advanced cancer to MaP therapy or wait-list control, with measures administered at baseline and after 6-8 weeks. Wait-list patients could then crossover to receive therapy, with further measures collected postintervention. Adherence to the manualized model was sustained through weekly supervision and fidelity coding of recorded sessions. We used generalized estimating equations to control for baseline and any correlation of data.ResultFrom 134 eligible participants, 57 (43%) consented, and 40 of 45 (89%) offered therapy completed 6 sessions. Key barriers to consenting patients were poor health (15 refusers and 4 withdrawals) and death intervened in 6 participants. MaP therapy generated adequate effect sizes in posttraumatic growth (new possibilities, appreciation of life, and personal strength) and life attitudes (choices and goal seeking) to permit calculation of power for a formal randomized, controlled trial.Significance of resultsDelivery of this model of existentially oriented therapy is feasible and acceptable to patients. A properly powered randomized controlled trial is justified to examine the efficacy of this intervention.


Subject(s)
Neoplasms/therapy , Psychotherapy/standards , Adaptation, Psychological , Aged , Female , Humans , Male , Middle Aged , Neoplasms/psychology , Palliative Care/methods , Palliative Care/standards , Pilot Projects , Psychometrics/instrumentation , Psychometrics/methods , Psychotherapy/methods , Surveys and Questionnaires
2.
J Health Commun ; 21(sup2): 91-98, 2016.
Article in English | MEDLINE | ID: mdl-27683959

ABSTRACT

Health literacy (HL) refers to a person's ability to engage effectively with health information and services. We aimed to describe the HL of people receiving dialysis and the factors associated with it. A cross-sectional design was used, with demographic and clinical data as predictors. Participants were people receiving dialysis at a metropolitan health service in Melbourne, Australia. Health consumers with conditions not requiring dialysis were included for comparison. The Health Literacy Questionnaire, Kidney Disease Quality of Life-36, and Depression Anxiety Stress Scales-21 were administered. Participants (M age = 68.2 ± 13.7 years; n = 57 males) were 76 people receiving hemodialysis within a dialysis unit, 16 people receiving home peritoneal dialysis, and 8 people receiving home hemodialysis. Participants scored higher on the HL domains social support for health and engagement with health care providers but lower on active management of health than the comparison group (n = 813). Hierarchical cluster analysis revealed 2 clusters within the dialysis sample representing higher (n = 43) and lower (n = 57) profiles of HL. The higher HL cluster reported better quality of life across 4 of 5 domains of the Kidney Disease Quality of Life-36, fewer symptoms of depression and anxiety, and higher serum albumin (mean difference = 2.06 g/L, p = .04) than the lower HL cluster. These results show that people receiving dialysis feel better supported and informed about their health than other health consumers but are less active in managing it. Higher HL is associated with better mental health and quality of life. Identifying HL characteristics may help direct specific interventions to improve patient education and support.


Subject(s)
Health Literacy/statistics & numerical data , Quality of Life , Renal Dialysis , Stress, Psychological/etiology , Aged , Aged, 80 and over , Cluster Analysis , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , Renal Dialysis/psychology , Surveys and Questionnaires
3.
Appetite ; 92: 143-55, 2015 Sep.
Article in English | MEDLINE | ID: mdl-25979567

ABSTRACT

Functional bowel disorders such as irritable bowel syndrome are commonly experienced within the population, and have an adverse impact on emotions, physical well-being, social activity, and occupational output. Adherence to a restricted diet can reduce symptoms, which in turn leads to increased quality of life and well-being. The aim of this review was to assess the extent to which predictors of dietary adherence have been considered in studies relating to functional bowel disorders and following a restricted diet. This was done firstly by examining such studies which contained a measure or indicator of adherence, and then by examining predictors of adherence within and between studies. A search of PsycINFO, Medline, CINAHL, Web of Science, and Cochrane databases was performed during July 2014, with the search criteria including relevant terms such as gastrointestinal disorder, irritable bowel syndrome, diet, and adherence. Of an initial 7927 papers, 39 were suitable for inclusion. Fourteen of the 39 studies included had a structured measure or indicator of dietary adherence, and the remaining 25 mentioned adherence without any structured levels of adherence. There was little investigation into the predictors of adherence, with symptom relief or induction being the primary goal of most of the studies. This review indicates that predictors of dietary adherence are rarely considered in research regarding functional bowel disorders. Further investigation is needed into the variables which contribute to rates of adherence to restricted diets, and more rigorous research is needed to characterise those individuals most likely to be non-adherent. Such research is necessary to ensure that people with these conditions can be provided with appropriate support and interventions.


Subject(s)
Diet Therapy , Gastrointestinal Diseases/diet therapy , Patient Compliance , Adolescent , Adult , Aged , Aged, 80 and over , Diet , Diet Therapy/psychology , Gastrointestinal Diseases/physiopathology , Gastrointestinal Diseases/psychology , Humans , Irritable Bowel Syndrome/diet therapy , Irritable Bowel Syndrome/physiopathology , Irritable Bowel Syndrome/psychology , Middle Aged , Patient Compliance/psychology , Patient Compliance/statistics & numerical data , Quality of Life
4.
Cardiovasc Pathol ; 19(6): 361-70, 2010.
Article in English | MEDLINE | ID: mdl-19747849

ABSTRACT

INTRODUCTION: Diabetes in human subjects is often associated with hypertension. The aim of this study was to examine the development of cardiac fibrosis following induction of type 1 diabetes in genetically hypertensive rats. METHODS: Diabetes was induced by streptozotocin (STZ) injection in 8-week-old normotensive Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHRs) for a duration of 16 or 24 weeks. Aged-matched, nondiabetic WKY and SHRs were used as controls. At termination of treatment, the rats were anaesthetized, hearts arrested in diastole and perfusion fixed. A comprehensive examination of cardiac fibrosis throughout the right and left ventricles was undertaken in picrosirius red-stained sections, using image analysis and by undertaking collagen type I and type III immunohistochemistry. RESULTS: Induction of diabetes in the SHRs led to a marked increase in the levels of interstitial fibrosis in the left ventricle plus septum (LV+S) at both 16 and 24 weeks duration (59% and 43% increase, respectively) and also in the right ventricle after 24 weeks duration of diabetes (35% increase compared to the nondiabetic SHR). Exacerbated perivascular fibrosis was also observed in the LV+S in the diabetic-hypertensive rats at the later time point. These effects of induction of diabetes were not observed in the normotensive strain. CONCLUSIONS/INTERPRETATION: Our findings clearly demonstrate elevations in cardiac fibrosis when type 1 diabetes is combined with hypertension. Our findings thus stress the importance of closely monitoring both blood pressure and glucose levels in type 1 diabetic patients in order to prevent myocardial collagen deposition.


Subject(s)
Diabetes Mellitus, Experimental/complications , Diabetes Mellitus, Type 1/complications , Heart Diseases/etiology , Hypertension/complications , Myocardium/pathology , Actins/metabolism , Animals , Blood Pressure , Body Weight , Collagen Type I/metabolism , Collagen Type III/metabolism , Coronary Vessels/pathology , Diabetes Mellitus, Experimental/metabolism , Diabetes Mellitus, Experimental/pathology , Diabetes Mellitus, Experimental/physiopathology , Diabetes Mellitus, Type 1/metabolism , Diabetes Mellitus, Type 1/pathology , Diabetes Mellitus, Type 1/physiopathology , Fibrosis , Heart Diseases/metabolism , Heart Diseases/pathology , Heart Diseases/physiopathology , Hypertension/metabolism , Hypertension/pathology , Hypertension/physiopathology , Immunohistochemistry , Macrophages/pathology , Male , Monocytes/pathology , Rats , Rats, Inbred SHR , Rats, Inbred WKY , Time Factors
5.
J Lab Clin Med ; 147(1): 36-44, 2006 Jan.
Article in English | MEDLINE | ID: mdl-16443003

ABSTRACT

This study examines the existence of the urinary albumin degradation pathway and the proposed role of receptor-mediated endocytosis in this process using the isolated perfused rat kidney (IPK) model. Albumin-derived peptides in IPK urine are analyzed in terms of their relative size distribution using radioactivity and absorbance at 214 nm, and their susceptibility to trypsin digestion. The effects of perfusing kidneys with concanamycin A and myristoyl trimethyl ammonium bromide (MTMAB), inhibitors of the receptor-mediated endocytosis regulators vacuolar-type H(+) ATPase (v-ATPase) and dynamin GTPase, respectively, are examined. Normal IPK urine contains mildly degraded (defined as approximately 10-40 kDa; 43.0 +/- 8.3%) and heavily degraded (defined as <10 kDa; 22.6 +/- 7.7%) albumin peptides as well as intact albumin (34.5 +/- 4.1%). The relative size distribution of the peptides is similar by radioactivity and absorbance at 214 nm, and both profiles are reduced to very small peptides following trypsin digestion. Administration of concanamycin A or MTMAB causes a significant increase in the proportion of intact albumin (concanamycin A: 55.8 +/- 11.6%; MTMAB: 50.0 +/- 11.9%) excreted compared with normal IPK urine. This coincides with a reduction in the proportion of mildly (concanamycin A: 27.6 +/- 9.8%; MTMAB: 39.9 +/- 11.5%) and heavily degraded (concanamycin A: 16.6 +/- 7.4%; MTMAB: 10.0 +/- 2.5%) albumin present and is not associated with changes in glomerular permeability to albumin because no significant change is observed in the fractional clearance of Ficoll (radius range 20-60 A) in the presence of concanamycin A. This study demonstrates the existence of albumin peptides in IPK urine and suggests that receptor-mediated endocytosis plays a role in urinary albumin degradation.


Subject(s)
Endocytosis/physiology , Kidney/metabolism , Peptide Fragments/urine , Serum Albumin, Bovine/pharmacokinetics , Animals , Biotransformation , Chromatography , Chromatography, High Pressure Liquid , Endocytosis/drug effects , Enzyme Inhibitors/pharmacology , Glomerular Filtration Rate , Macrolides/pharmacology , Male , Perfusion , Quaternary Ammonium Compounds/pharmacology , Rats , Rats, Sprague-Dawley , Trimethyl Ammonium Compounds
6.
Clin Biochem ; 39(2): 143-51, 2006 Feb.
Article in English | MEDLINE | ID: mdl-16325791

ABSTRACT

OBJECTIVES: To compare the analysis of different forms of intact albumin in urine from healthy volunteers. To determine contamination by common non-albumin proteins on HPLC analysis of urinary albumin and of purified immuno-unreactive albumin. DESIGN AND METHODS: Overnight urine samples collected from healthy volunteers were analysed for total albumin (immunoreactive plus immuno-unreactive) by HPLC and densitometry following native PAGE separation and for immunoreactive albumin by RIA. The contamination by non-albumin proteins of the HPLC analysis of urinary albumin and of immuno-unreactive albumin preparations was determined by ELISA. Immuno-unreactive albumin was tested for Co2+-binding capacity. RESULTS AND CONCLUSIONS: HPLC analysis of healthy urine generates higher ACR values than immunological methods due to the presence of immuno-unreactive albumin. Immuno-unreactive albumin cannot be accounted for by the non-albumin urinary proteins tested. Isolated immuno-unreactive albumin is not recognised by antibodies to common urinary proteins or by an array of anti-albumin antibodies and behaves like serum albumin in terms of HPLC elution, native PAGE migration, and cobalt ion binding.


Subject(s)
Albuminuria , Proteinuria , Urinalysis/methods , Adolescent , Adult , Aged , Antibodies, Monoclonal , Chromatography, High Pressure Liquid , Cobalt/chemistry , Creatinine/urine , Electrophoresis, Polyacrylamide Gel , Enzyme-Linked Immunosorbent Assay , Female , Humans , Male , Middle Aged , Radioimmunoassay
7.
J Am Soc Nephrol ; 16(8): 2363-72, 2005 Aug.
Article in English | MEDLINE | ID: mdl-15930093

ABSTRACT

Recent studies have identified that first-line renoprotective agents that interrupt the renin-angiotensin system not only reduce BP but also can attenuate advanced glycation end product (AGE) accumulation. This study used in vitro, preclinical, and human approaches to explore the potential effects of these agents on the modulation of the receptor for AGE (RAGE). Bovine aortic endothelial cells that were exposed to the angiotensin-converting enzyme inhibitor (ACEi) ramiprilat in the presence of high glucose demonstrated a significant increase in soluble RAGE (sRAGE) secreted into the medium. In streptozotocin-induced diabetic rats, ramipril treatment (ACEi) at 3 mg/L for 24 wk reduced the accumulation of skin collagen-linked carboxymethyllysine and pentosidine, as well as circulating and renal AGE. Renal gene upregulation of total RAGE (all three splice variants) was observed in ACEi-treated animals. There was a specific increase in the gene expression of the splice variant C-truncated RAGE (sRAGE). There were also increases in sRAGE protein identified within renal cells with ACEi treatment, which showed AGE-binding ability. This was associated with decreases in renal full-length RAGE protein from ACEi-treated rats. Decreases in plasma soluble RAGE that were significantly increased by ACEi treatment were also identified in diabetic rats. Similarly, there was a significant increase in plasma sRAGE in patients who had type 1 diabetes and were treated with the ACEi perindopril. Complexes between sRAGE and carboxymethyllysine were identified in human and rodent diabetic plasma. It is postulated that ACE inhibition reduces the accumulation of AGE in diabetes partly by increasing the production and secretion of sRAGE into plasma.


Subject(s)
Diabetic Nephropathies/metabolism , Peptidyl-Dipeptidase A/metabolism , Receptors, Immunologic/metabolism , Alternative Splicing , Angiotensin-Converting Enzyme Inhibitors/pharmacology , Animals , Aorta/cytology , Arginine/analogs & derivatives , Arginine/chemistry , Blotting, Western , Cattle , Cells, Cultured , Collagen/metabolism , DNA Primers/chemistry , Diabetic Nephropathies/blood , Endothelium, Vascular/cytology , Glycation End Products, Advanced/blood , Glycation End Products, Advanced/metabolism , Humans , Immunohistochemistry , Immunoprecipitation , Kidney Cortex/metabolism , Lysine/analogs & derivatives , Lysine/chemistry , Male , Microscopy, Fluorescence , Molecular Weight , Ramipril/analogs & derivatives , Ramipril/pharmacology , Rats , Rats, Sprague-Dawley , Receptor for Advanced Glycation End Products , Receptors, Immunologic/blood , Reverse Transcriptase Polymerase Chain Reaction , Skin/metabolism , Time Factors , Up-Regulation
8.
J Lab Clin Med ; 145(5): 239-46, 2005 May.
Article in English | MEDLINE | ID: mdl-15902096

ABSTRACT

Large quantities of peptides (1-4 g) are excreted in human urine each day. In this study we sought to analyze how peptide excretion varies with increasing albuminuria associated with diabetes, as well as to characterize the size distribution of albumin-derived peptides in urine from volunteers without diabetes and from patients with macroalbuminuria and diabetes. We detected albumin-derived peptides by injecting tritiated albumin intravenously into human volunteers and patients with diabetes. Urine was collected after 24 hours and fractionated on a size-exclusion column. This fractionation revealed peptides with molecular weights ranging from 300 to 500 Da in volunteers without diabetes. The albumin-derived peptides were of higher molecular weight in the urine of a patient with macroalbuminuria and diabetes. The molecular-weight distribution of the peptides derived from tritiated albumin peptides was paralleled by the distribution of all protein peptides (including albumin) as determined with the use of the Biuret protein assay or absorbance at 214 nm. We determined peptide-excretion rates by filtering urine from patients with diabetes through a 10,000 Da molecular-weight-cutoff membrane and then measuring the filtrate with the use of the Biuret assay. This analysis revealed that the peptide-excretion rate increased with increasing total protein excretion, regardless of whether the patient demonstrated normoalbuminuria or microalbuminuria. Among patients with macroalbuminuria, the peptide-excretion rate leveled off and even decreased in the face of an increasing albumin concentration or protein-excretion rate. This study confirms that albumin-derived and protein-derived peptides exist at high concentrations in urine. Although peptide-excretion rates are maintained at similar levels up to macroalbuminuric states, the relative proportion of peptide excretion is significantly reduced compared with total protein.


Subject(s)
Diabetes Mellitus/urine , Peptides/urine , Albumins , Albuminuria/urine , Chromatography, Gel , Humans , Molecular Weight , Peptides/chemistry , Proteinuria/urine , Tritium
9.
Adv Chronic Kidney Dis ; 12(2): 170-6, 2005 Apr.
Article in English | MEDLINE | ID: mdl-15822052

ABSTRACT

Microalbuminuria is an important clinical marker in patients with diabetes and cardiovascular disease. The concentration of albumin in urine has traditionally been measured by semiquantitative dipsticks or by various quantitative immunochemical methods such as immunonephelometry, immunoturbidimetry, and radioimmunoassay. However, until recently, urinary albumin not reabsorbed by proximal tubular cells was assumed to be excreted intact. Studies have now revealed that the nature of urinary albumin is complex and is excreted as a mixture of intact albumin, albumin-derived peptides that are not detected by routine dipstick and antibody-based tests, and a species of intact albumin (immunounreactive albumin), also not detected by dipstick and antibody-based tests. A new test, Accumin, based on high-performance liquid chromatography analysis, is able to detect all the immunoreactive intact albumin and immunounreactive intact albumin (total intact albumin) in urine. The advantage in the use of Accumin over a conventional dipstick test or antibody-based laboratory method for detecting microalbuminuria is that false negatives are reduced and a relatively earlier diagnosis of incipient kidney disease can be achieved. The introduction of Accumin has, therefore, highlighted the need for a global standard in the detection and measurement of microalbuminuria. By detecting all of the immunoreactive and immunounreactive intact albumin in urine, Accumin has virtually invalidated the use of dye and immunologically-based dipstick tests and immunologically-based laboratory methods in screening for microalbuminuria in diabetic patients and in identifying microalbuminuria as a risk factor for cardiovascular disease.


Subject(s)
Albuminuria/diagnosis , Chromatography, Liquid/methods , Diagnostic Techniques, Urological/instrumentation , Humans , Predictive Value of Tests
10.
Kidney Int Suppl ; (92): S65-6, 2004 Nov.
Article in English | MEDLINE | ID: mdl-15485422

ABSTRACT

Recent studies have demonstrated the presence, in both rat and human urine, of a modified form of albumin not detected by conventional antibodies. This modified albumin behaves physicochemically as intact albumin under nondenaturing conditions. We have demonstrated this form of albumin to be disproportionately excreted in microalbuminuric states in diabetes. Quantitation of this modified form of albumin leads to the prediction of the onset of microalbuminuria in diabetic patients on average 3 to 4 years earlier than when measured by conventional immunoassays.


Subject(s)
Albumins/metabolism , Albuminuria/diagnosis , Albuminuria/urine , Diabetic Nephropathies/diagnosis , Diabetic Nephropathies/urine , Albumins/analysis , Electrophoresis, Polyacrylamide Gel , Humans
11.
Kidney Int Suppl ; (92): S67-8, 2004 Nov.
Article in English | MEDLINE | ID: mdl-15485423

ABSTRACT

The major underlying factors associated with tissue damage and fibrosis in cardiovascular and kidney disease are the up-regulation and action of growth factors such as transforming growth factor-beta (TGF-beta) and cytokines produced in response to changes in systemic factors, particularly blood pressure or hyperglycemia. This study identifies the relationship of elevated levels of TGF-beta to increased levels of intact albumin in the urine (micro- and macroalbuminuria). This mechanism may be directly linked to the effect of TGF-beta on albumin uptake and the lysosomal breakdown of filtered albumin by proximal tubular cells prior to excretion.


Subject(s)
Albuminuria/physiopathology , Cardiovascular Diseases/physiopathology , Albuminuria/genetics , Animals , Cardiovascular Diseases/genetics , Extracellular Matrix Proteins/genetics , Transforming Growth Factor beta/genetics , Transforming Growth Factor beta1
12.
Clin Chem ; 50(12): 2286-91, 2004 Dec.
Article in English | MEDLINE | ID: mdl-15388637

ABSTRACT

BACKGROUND: Conventional immunoassays underestimate the urinary albumin concentration because intact albumin in urine exists in two forms, immunoreactive and immunochemically nonreactive. METHODS: Urinary albumin concentration measured by HPLC (which measures total albumin, i.e., the sum of immunoreactive albumin + immunochemically nonreactive albumin) or RIA was compared with densitometric analysis of albumin bands in diabetic urine samples separated by either native polyacrylamide gel electrophoresis (PAGE) or reducing sodium dodecyl sulfate (SDS)-PAGE. Immunochemically nonreactive albumin was also isolated from diabetic urine (relative amount detected, 70-80% of the expected) and was tested for contamination by common urinary proteins by native PAGE, ELISA, and capillary electrophoresis. RESULTS: Urinary albumin concentrations measured by native PAGE and HPLC were better correlated (r(2) = 0.83) than concentrations measured by native PAGE and RIA (r(2) = 0.62) because under native conditions both native PAGE and HPLC detect total albumin and not only the immunoreactive albumin alone that is measured by RIA. Urinary albumin concentrations measured by reducing SDS-PAGE and RIA were better correlated (r(2) = 0.84) than concentrations measured by reducing SDS-PAGE and HPLC (r(2) = 0.65) because under reducing conditions immunochemically nonreactive albumin is unstable and fragments into many smaller peptides. The partially purified preparation was found to contain <1% contamination by common urinary proteins and is stable to freezing and frequent freeze/thaw cycles. CONCLUSIONS: The results are consistent with the interpretation that immunochemically nonreactive albumin has a limited number of polypeptide chain scissions and is held together by noncovalent intrachain bonding and disulfide bonds. Detection of this molecule is likely to be of clinical importance in diagnosing kidney disease as well as cardiovascular disease.


Subject(s)
Albumins/analysis , Albuminuria/diagnosis , Diabetes Complications/diagnosis , Diabetes Mellitus/urine , Albumins/chemistry , Chromatography, High Pressure Liquid , Densitometry , Electrophoresis, Polyacrylamide Gel , Enzyme-Linked Immunosorbent Assay , Humans , Radioimmunoassay
14.
Kidney Int ; 65(5): 1850-5, 2004 May.
Article in English | MEDLINE | ID: mdl-15086926

ABSTRACT

BACKGROUND: Microalbuminuria is regarded as the most important predictor of high risk for the development of diabetic nephropathy. Early detection may allow treatment to prevent progression to persistent albuminuria and renal failure. Recent studies have shown that conventional immunoassays underestimate urinary albumin concentration, as albumin in urine may exist in two forms, immuno-reactive and immuno-unreactive. The present study examines the differential lead-time for the development of microalbuminuria as measured by both conventional radioimmunoassay (RIA; measures immuno-reactive) and high-performance liquid chromatography (HPLC; measures total albumin = immuno-reactive plus immuno-unreactive) analysis in both type 1 and type 2 diabetic patients. METHODS: Analysis was performed on 511 stored urine samples collected over the last 13 years from type 1 diabetic patients who either progressed from normo- to microalbuminuria (progressors, N= 17), or who remained normoalbuminuric (nonprogressors, N= 25) as defined by RIA, and on 634 urine samples collected from patients with type 2 diabetes defined as either progressors (N= 24) or nonprogressors (N= 25). RESULTS: For type 1 progressors, the mean lead-time for the HPLC assay versus the RIA was 3.9 years, with a 95% CI of 2.1 to 5.6 years. For type 2 progressors, the mean lead-time was 2.4 years with a 95% CI of 1.2 to 3.5 years. There was no significant difference between the lead-time analysis between type 1 and type 2 diabetic patients. CONCLUSION: These results demonstrate that measurement of total albumin may allow earlier detection of microalbuminuria associated with diabetic nephropathy.


Subject(s)
Albumins/analysis , Albuminuria/diagnosis , Diabetes Mellitus, Type 1/urine , Diabetes Mellitus, Type 2/urine , Diabetic Nephropathies/diagnosis , Diabetic Nephropathies/urine , Urinalysis/methods , Adult , Albuminuria/urine , Chromatography, High Pressure Liquid/methods , Chromatography, High Pressure Liquid/statistics & numerical data , Female , Humans , Male , Middle Aged , Radioimmunoassay , Sensitivity and Specificity , Urinalysis/statistics & numerical data
15.
Clin Biochem ; 37(2): 105-11, 2004 Feb.
Article in English | MEDLINE | ID: mdl-14725940

ABSTRACT

OBJECTIVES: To compare the analysis of urinary albumin from diabetic patients by four conventional immunoassays including radioimmunoassay (RIA), immunonephelometry (IN), and two different methods of immunoturbidimetry (IT), as well as by high-performance liquid chromatography (HPLC). DESIGN AND METHODS: Urines were collected over a 24-h period and stored at -20 degrees C until assay. Urinary albumin concentration was determined by an in-house RIA, by IN using a Beckman Array Analyser with reagents from Beckman Diagnostics (Sydney, Australia), by IT using a Dade-Behring Turbitimer with reagents from Dade-Behring (Marburg, Germany), by IT using a Dade-Behring Dimension R x L Chemistry Analyser with reagents from DiaSorin (Stillwater, OK, USA), and by HPLC using a Zorbax Bio series preparative GF-250 column. Regression lines were calculated using a least squares method to determine the correlation between the assays studied. Bland-Altman bias plots including limits of agreement were also calculated. RESULTS: The correlation coefficients calculated were high (>0.85) indicating a strong linear relationship between all assays studied. The slopes calculated for the comparisons demonstrate that each assay can vary from one another (up to threefold) and have a slope significantly different from an ideal slope of 1 (P < 0.001). These results were confirmed by Bland-Altman bias plots and calculation of the limits of agreement that were all large. CONCLUSIONS: At this time, there is no global standard by which urinary albumin assays may be standardized. This study suggests the need for such standards.


Subject(s)
Albumins/metabolism , Albuminuria/urine , Diabetic Nephropathies/diagnosis , Chemistry, Clinical/methods , Chromatography, High Pressure Liquid/methods , Diabetic Nephropathies/urine , Female , Humans , Immunoassay/methods , Male , Regression Analysis , Reproducibility of Results , Sensitivity and Specificity
16.
Nephrol Dial Transplant ; 19(2): 320-8, 2004 Feb.
Article in English | MEDLINE | ID: mdl-14736954

ABSTRACT

BACKGROUND: Plasma albumin has been considered as important for governing glomerular permselectivity as well as being tubulotoxic in proteinuric states. The purpose of this study was to examine glomerular permselectivity and protein clearance of plasma albumin-deficient Nagase analbuminaemic rats (NAR) in normal and proteinuric states associated with puromycin aminonucleoside nephrosis (PAN) and anti-glomerular basement membrane glomerulonephritis (anti-GBM GN) and to compare the results with those of previous studies using Sprague-Dawley rats. METHODS: Glomerular permselectivity was measured using tritium-labelled polydisperse Ficoll. In vivo fractional clearance (FC) of albumin, transferrin and immunoglobulin G was measured to include both intact and degraded forms of filtered material. Endogenous protein clearance was analysed using two-dimensional electrophoresis in combination with matrix-assisted laser desorption ionization (MALDI) mass spectrometry. RESULTS: FCs of proteins and Ficoll in control NAR were similar to those found in Sprague-Dawley rats. Despite the lack of serum albumin in NAR, proteinuria and morphological changes observed were also similar to those found in Sprague-Dawley rats, with total protein excretion increasing 6-fold in PAN rats and 4-fold in anti-GBM GN rats with respect to controls. Two-dimensional electrophoresis in combination with MALDI mass spectrometry identified the major proteins being excreted as transferrin and a group of mildly acidic proteins in the MW range 40-50 kDa, namely antithrombin III, kininogen, alpha-1-antiproteinase, haemopexin and vitamin D-binding protein. CONCLUSIONS: Both diseases exhibited similar effects to those observed in Sprague-Dawley rats despite the lack of serum albumin, including inhibition of renal protein degradation. The net changes in protein FC, particularly in the range of radii of 36-55 A, could not be accounted for by changes in size selectivity as Ficoll FC was little affected by the disease states. This emphasizes the need to reassess the relative importance of changes in renal tubular handling vs changes in glomerular capillary barrier in proteinuric states. These studies also demonstrate that albumin is not a critical factor in governing glomerular permselectivity or proteinuria.


Subject(s)
Albuminuria/diagnosis , Blood Proteins/metabolism , Glomerulonephritis/pathology , Glomerulonephritis/physiopathology , Proteinuria/diagnosis , Acetylglucosaminidase , Albuminuria/etiology , Animals , Blood Protein Electrophoresis , Chromatography , Disease Models, Animal , Female , Glomerular Filtration Rate , Glomerulonephritis/complications , Immunoglobulin G/analysis , Male , Probability , Proteinuria/etiology , Radioimmunoassay , Rats , Rats, Sprague-Dawley , Sensitivity and Specificity , Transferrin/metabolism
18.
J Hypertens ; 21(12): 2399-407, 2003 Dec.
Article in English | MEDLINE | ID: mdl-14654761

ABSTRACT

OBJECTIVE: This study examined the separate and combined effects of hypertension and diabetes on renal cortical expression of protein kinase C (PKC) isoforms -beta 1, -beta 2, -alpha and -epsilon, to determine whether albuminuria is the result of an increase in the expression of one or a combination of PKC isoforms. Corresponding changes in renal microtubules were also assessed. METHODS: Diabetes (D) was induced in Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR) by streptozotocin. After 24 weeks, PKC expression was determined by Western blot and microtubules were assessed by immunohistochemistry for alpha-tubulin protein. RESULTS: Diabetes was characterized by significant increases in glycated haemoglobin (HbA1c) as compared to controls (C). There was a significant increase of three- to four-fold in PKC protein content for all four isoforms in renal cortex from SHR-C and WKY-D, and similar and significant levels of albuminuria (approximately 10 mg/24 h) observed in these groups in comparison to WKY-C (approximately 1 mg/24 h). Interestingly, PKC-alpha and -epsilon but not PKC-beta 1 and -beta 2 protein content was doubled in SHR-D, and albuminuria increased tenfold (approximately 100 mg/24 h) in comparison to SHR-C and WKY-D. These changes were paralleled by a significant decrease in alpha-tubulin protein content of approximately 50% in SHR-C and approximately 33% in WKY-D compared to WKY-C, with a further decrease of approximately 67% in SHR-D compared to WKY-C. CONCLUSION: These findings indicate that PKC expression can be increased by either diabetes or hypertension, and that there are further specific increases in the expression of PKC isoforms -alpha and -epsilon in the model of combined diabetes and hypertension. In addition, the degree of disruption in microtubular cytoskeleton appears to be correlated with PKC activation and levels of albuminuria.


Subject(s)
Diabetes Mellitus, Experimental/metabolism , Hypertension/metabolism , Kidney Cortex/enzymology , Protein Kinase C/biosynthesis , Tubulin/biosynthesis , Albuminuria/metabolism , Albuminuria/physiopathology , Animals , Biomarkers/analysis , Blood Pressure/physiology , Diabetes Mellitus, Experimental/physiopathology , Disease Models, Animal , Hypertension/physiopathology , Male , Models, Cardiovascular , Protein Kinase C beta , Protein Kinase C-alpha , Protein Kinase C-epsilon , RNA, Messenger/biosynthesis , Rats , Rats, Inbred SHR , Rats, Inbred WKY , Renal Circulation/physiology , Systole/physiology
19.
Arch Biochem Biophys ; 419(1): 55-62, 2003 Nov 01.
Article in English | MEDLINE | ID: mdl-14568009

ABSTRACT

Advanced glycation endproducts (AGEs) have been postulated to play a role in the development of both nephropathy and large vessel disease in diabetes. However, it is still not clear which AGE subtypes play a pathogenetic role and which of several AGE receptors mediate AGE effects on cells. This review summarises the renoprotective effect of inhibitors of AGE formation, including aminoguanidine, and of cross-link breakers, including ALT-711, on experimental diabetic nephropathy and on mesenteric vascular hypertrophy. It also demonstrates similar effects of aminoguanidine and ramipril (an angiotensin converting enzyme inhibitor) on fluorescent and immunoassayable AGE levels, renal protein kinase C activity, nitrotyrosine expression, lysosomal function, and protein handling in experimental diabetes. These findings indicate that inhibition of the renin angiotensin system blocks both upstream and downstream pathways leading to tissue injury. We postulate that the chemical pathways leading to advanced glycation endproduct formation and the renin angiotensin systems may interact through the generation of free radicals, induced both by glucose and angiotensin II. There is also evidence to suggest that AGE-dependent pathways may play a role in the development of tubulointerstitial fibrosis in the diabetic kidney. This effect is mediated through RAGE and is TGF-beta and CTGF-dependent.


Subject(s)
Diabetes Mellitus, Type 2/physiopathology , Diabetic Angiopathies/metabolism , Diabetic Nephropathies/metabolism , Glycation End Products, Advanced/metabolism , Albuminuria/drug therapy , Angiotensin-Converting Enzyme Inhibitors/pharmacology , Animals , Enzyme Inhibitors/pharmacology , Forecasting , Guanidines/pharmacology , Humans , Protein Kinase C/drug effects , Ramipril/pharmacology , Renin-Angiotensin System/drug effects , Thiazoles/pharmacology
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