OBJECTIVE: To develop a rapid detection method for microalbuminuria with size-exclusion high performance liquid chromatography. METHODS: With a new mobile phase, samples were injected onto an Agilent Zorbax GF-250 size exclusion chromatographic column. The method was evaluated and urine albumin of 56 diabetic patients was analyzed. RESULTS: The mobile phase containing 0.1% formic acid and acetonitrile, with 20 μL sample size, 1 mL/min flow rate, 205 nm detection wavelength. The retention time of albumin both in human serum and urine was 1.7 min. The linear range was 5-2000 mg/L. The lower limit of measurement was 2 mg/L. The intra-assay coefficient of variation and the inter-assay coefficient of variation were 3.98% and 4.05% (20 mg/L), 3.55% and 3.60% (200 mg/L), 4.65% and 4.74% (2000 mg/L), respectively. Recovery rates were 95.3%, 98.1%, and 97.2%. Microalbuminuria was detected in 30 samples by high performance liquid chromatography and 15 samples by immunoturbidimetry from 56 patients with diabetic mellitus. CONCLUSION A fast and high sensitivity method, namely size-exclusion high performance liquid chromatography, with mobile phase containing 0.1% formic acid and acetonitrile has been established to analyze microalbuminuria, which can detect more microalbuminuria than other methods and is suitable for clinical routine measurement.
Albuminuria ; diagnosis ; Chromatography, High Pressure Liquid ; Diabetes Mellitus ; urine ; Humans

OBJECTIVETo investigate the renal function in newborns with birth asphyxia or intrauterine distress in the first week of life.

METHODSSixty full-term newborns born between June 2002 and February 2003 were assigned into three groups: Control group (healthy newborns), Intrauterine distress group (Apgar score > 7), and Birth asphyxia group without intrauterine distress (12 mild asphyxia and 8 severe asphyxia) (n=20 each). Urinary levels of alpha1-microglobulin (alpha1-MG), beta2-microglobulin (beta2-MG) and albumin (Alb) were detected by radioimmunoassay at 0-2, 3-4 and 6-7 days after birth.

RESULTSThe urinary levels of alpha1-MG, beta2-MG and Alb in the Asphyxia group were significantly higher than those in the Control group at all time points (P < 0.05), peaking at 3-4 days after birth. Statistically significant differences were found between the severely and mildly asphyxiated newborns for the urinary levels of alpha1-MG, beta2-MG and Alb at all time points (P < 0.05). There were no significant differences in the urinary levels of alpha1-MG, beta2-MG and Alb between the Intrauterine distress and the Control groups at each time point.

CONCLUSIONSBirth asphyxia may lead to renal glomerular and tubular impairments and it is speculated that the most serious impairment occurs at the 3rd and 4th days of life. The severity of renal impairments is associated with the degree of asphyxia. The renal function of the newborn appears to be normal following intrauterine distress.

Albuminuria ; urine ; Alpha-Globulins ; urine ; Asphyxia Neonatorum ; physiopathology ; Fetal Distress ; physiopathology ; Humans ; Infant, Newborn ; Kidney ; physiopathology ; beta 2-Microglobulin ; urine

OBJECTIVETo estimate the biological exposure limit (BEL) using benchmark dose (BMD) based on two sets of data from occupational epidemiology.

METHODSCadmium-exposed workers were selected from a cadmium smelting factory and a zinc product factory. Doctors, nurses or shop assistants living in the same area served as a control group. Urinary cadmium (UCd) was used as an exposure biomarker and urinary beta2-microgloburin (B2M), N-acetyl-13-D-glucosaminidase (NAG) and albumin (ALB) as effect biomarkers. All urine parameters were adjusted by urinary creatinine. Software of BMDS (Version 1.3.2, EPA.U.S.A) was used to calculate BMD.

RESULTSThe cut-off point (abnormal values) was determined based on the upper limit of 95% of effect biomarkers in control group. There was a significant dose response relationship between the effect biomarkers (urinary B2M, NAG; and ALB) and exposure biomarker (UCd). BEL value was 5 microg/g creatinine for UB2M as an effect biomarker, consistent with the recommendation of WHO. BEL could be estimated by using the method of BMD. BEL value was 3 microg/g creatinine for UNAG as an effect biomarker. The more sensitive the used biomarker is, the more occupational population will be protected.

CONCLUSIONBMD can be used in estimating the biological exposure limit (BEL). UNAG is a sensitive biomarker for estimating BEL after cadmium exposure.

Acetylglucosaminidase ; urine ; Albuminuria ; urine ; Biomarkers ; urine ; Cadmium ; toxicity ; urine ; Dose-Response Relationship, Drug ; Female ; Humans ; Male ; Occupational Exposure ; Spectrophotometry, Atomic ; beta 2-Microglobulin ; urine

OBJECTIVEBased on two sets of data from occupational epidemiology, Benchmark dose (BMD) was applied to estimate biological exposure limit (BEL).

METHODSCadmium exposed workers were selected from a cadmium smelting and a zinc products factory and control group was selected from doctors or nurses and staff from shops living in the same area; Urinary cadmium (UCd) was used as exposure biomarker and urinary beta(2) microglobulin (UBM), NAG (UNAG) and albumin (UALB) were as effect biomarkers. All urine parameters were adjusted by urinary creatinine. Software of BMDS (Version 1.3.2, EPA.U.S) was used to calculate BMD.

RESULTSCalculated abnormal prevalence was based on the upper limit of 95% of effect biomarkers in control group; There are significant dose response relationship between the prevalence of effect biomarkers (UBM, UNAG and UALB) and exposure biomarker (UCd); BEL was 5 microg/g creatinine for UBM as effect biomarker, It consists with the recommendation of WHO; BEL was 3 microg/g creatinine for UNAG as effect biomarker; BEL can be estimated by using the method of BMD; the more sensitive biomarker would used, the more occupational people would protected.

CONCLUSIONThe application of BMD in estimating biological exposure limit (BEL) is proper. UNAG is suggested as most sensitive biomarker to be used to estimate BEL for cadmium exposure.

Acetylglucosaminidase ; urine ; Albuminuria ; urine ; Biomarkers ; urine ; Cadmium ; adverse effects ; urine ; Dose-Response Relationship, Drug ; Female ; Humans ; Male ; Occupational Exposure ; Reference Values ; beta 2-Microglobulin ; urine

OBJECTIVETo determine whether urinary type IV collagen can serve as an indicator specific for diabetic nephropathy.

METHODSUsing a novel sandwich ABC-ELISA to measure type IV collagen directly, the 24-hour urinary type IV collagen excretion rate was determined in 120 diabetic patients and some groups of controls. Urinary albumin determinations were made with a RIA kit at the same time. A total of 13 diabetic patients with microalbuminuria underwent percutaneous renal biopsy for definitive diagnosis of diabetic nephropathy. Type IV collagen and TGF-beta 1 immunoreactivities were detected with ABC methods in renal biopsies.

RESULTSUrinary type IV collagen excretion was significantly increased in diabetic patients with microalbuminuria, especially those with albumin excretion above 200 mg/24 h. By comparison, collagen excretion was equivalent to that in healthy controls when measured in diabetics with normalbuminuria and in patients with primary glomerular disease, primary hypertension, or coronary heart disease. Urinary type IV collagen excretion in diabetics was negatively correlated with creatinine clearance. In renal biopsies from subjects with elevated collagen excretion, the glomeruli showed pathological changes typical of diabetic nephropathy. Also, excessive type IV collagen and TGF-beta 1 immunoreactivity were detected in the glomeruli, Bowman's capsule and interstitium.

CONCLUSIONSExcretion of type IV collagen, possibly reflecting increased production or decreased degradation of this protein, may be a clinically useful indicator of incipient diabetic nephropathy.

Albuminuria ; urine ; Biomarkers ; urine ; Collagen Type IV ; urine ; Diabetes Mellitus, Type 2 ; urine ; Diabetic Nephropathies ; diagnosis ; Humans ; Transforming Growth Factor beta ; analysis

OBJECTIVETo examine the urinary level of tissue factor (uTF) and its procoagulant activity (PCA) in patients with diabetes mellitus, and explore the relationship between uTF and renal damage in diabetes mellitus.

METHODSEighty-six patients with type 2 diabetes mellitus were divided into 3 groups according to urine albumin excretion (UACR), namely normal albuminuria group, microalbuminuria group and macroalbuminuria group. The levels of uTF, PCA, blood urea nitrogen (BUN), serum creatinine (CRE), serum cystatin C (CYSC), glycohemoglobin A1c (HbA1c), and high-sensitivity C-reactive protein (hs-CRP) were measured in all the patients and 21 healthy controls.

RESULTSCompared with normal control, the diabetic patients showed significantly increased levels of uTF and PCA. The urinary TF-PCA was positively correlated to BUN, CYSC, CRE, UACR, fasting glucose and hs-CRP, but not to uTF; only hs-CRP, UACR were positively correlated to uTF.

CONCLUSIONuTF is probably implicated in the development and progression of diabetic nephropathy.

Adult ; Albuminuria ; urine ; Blood Coagulation ; Case-Control Studies ; Creatinine ; urine ; Diabetes Mellitus, Type 2 ; physiopathology ; urine ; Female ; Humans ; Male ; Middle Aged ; Thromboplastin ; urine

OBJECTIVETo determine the value of the urinary microalbumin/creatinine ratio (UACR) and the relationship between UACR and traditional cardiovascular risk factors among elderly community subjects.

METHODSA representative population in Shanghai rural district aged more than 65 years who participated in the heart health survey of the key projects in the national science and technology pillar program in the eleventh five-year plan period of China were sampled via a clustered complex sampling method. A midstream collection from the first morning void collected was used to measure the urinary microalbumin, the urinary creatinine and the UACR. Baseline information including traditional cardiovascular risk factors were obtained by standard questionaire to analyze the distribution status of UACR in the population with or without the risk factors.

RESULTS(1) There were 1718 subjects (721 males) of (73.3 ± 5.5) years included in this study. (2) The prevalence of with at least one cardiovascular risk factor was 78.00% in this cohort, the top there risk factors were dyslipidemia (61.06%), hypertension (44.59%) and diabetes (13.80%). (3) The median (the lower quartile-the upper quartile) of the UACR of the population without cardiovascular diseases and risk factors was 13.81 (6.03 - 26.51) µg/mg. The level of UACR was significantly higher in females than that in males [17.12 (7.28 - 33.28) µg/mg vs. 5.49 (2.92 - 9.76) µg/mg, P < 0.01]. (4) The level of UACR in population with hypertension, diabetes or dyslipidemia was 16.27 (6.65 - 42.00) µg/mg, 26.27 (10.92 - 76.65) µg/mg and 16.39 (6.98 - 41.03) µg/mg respectively, all exceeding that of the healthy group (P < 0.05 or P < 0.01). (5) The levels of UACR increased in proportion to the increase of cardiovascular risk factor numbers, the UACR of the population with 0, 1, 2, 3 and 4 cardiovascular risk factors were 13.81 (6.03 - 26.51) µg/mg, 15.76 (6.79 - 36.44) µg/mg, 13.82 (5.68 - 34.43) µg/mg, 16.47 (6.07 - 50.56) µg/mg and 18.63 (11.26 - 83.09) µg/mg, respectively. The population with 4 cluster of cardiovascular risk factors posed the higher level of UACR than that of population with 0 cardiovascular risk factors (P < 0.05).

CONCLUSIONSThe three most common risk factors of cardiovascular diseases among the elderly community subjects aged more than 65 years are dyslipidemia, hypertension and diabetes, all of which are related to the elevation of UACR.

Aged ; Albuminuria ; epidemiology ; Cardiovascular Diseases ; epidemiology ; urine ; Cohort Studies ; Creatinine ; urine ; Cross-Sectional Studies ; Female ; Humans ; Male ; Risk Factors

Acetylglucosaminidase ; urine ; Albuminuria ; physiopathology ; Child, Preschool ; Female ; Humans ; Infant ; Kidney ; physiopathology ; Male ; Seizures, Febrile ; physiopathology

Humans ; Albumins ; Albuminuria/urine* ; Blood Pressure ; China/epidemiology* ; Creatinine ; Risk Factors ; Aged

OBJECTIVETo study the diagnostic method for early renal injury in the workers exposed to mercury (Hg).

METHODSThe contents of urinary Hg were determined by chemical method. Urinary microalbumin (mALB), beta(2)-microglodulin (beta(2)-MG) and retinol binding protein (RBP) levels were measured with total quantitative enzyme immunoassay. The activities of urinary N-acetyl-beta-D-glucosaminidase (NAG) and gamma-glutamyl transferase (gamma-GT) were determined by rate methods. Urinary creatinine (Cr) was measured by using picric acid method.

RESULTSThe levels of urinary BRP, beta(2)-MG, NAG and gamma-GT in exposed workers [(439.7 +/- 201.4), (141.4 +/- 56.3) micro g/g Cr and (12.3 +/- 5.7), (60.3 +/- 18.5) U/g Cr respectively] were significantly higher than those in controls (P < 0.05, P < 0.01). The levels were increased gradually with the increasing contents of urinary Hg. The positive detection rate for single or two combined indexes was rather lower whereas that for 4 combined indexes was as high as 85.5%. A positive correlation was noted between the contents of urinary Hg and urinary BRP, beta(2)-MG, NAG and gamma-GT (r: 0.466, 0.379, 0.323, 0.311, P < 0.05). Urinary RBP was correlated to urinary beta(2)-MG, NAG and gamma-GT (r: 0.362, 0.354, 0.332, P < 0.05).

CONCLUSIONCombined detection of urinary RBP, beta(2)-MG, NAG and gamma-GT is a sensitive method for the diagnosis of early renal injury in the workers exposed to Hg.

Acetylglucosaminidase ; urine ; Adult ; Albuminuria ; urine ; Creatinine ; urine ; Female ; Humans ; Kidney ; injuries ; physiopathology ; Kidney Diseases ; etiology ; urine ; Male ; Mercury Poisoning ; complications ; Middle Aged ; Occupational Exposure ; adverse effects ; Retinol-Binding Proteins ; urine ; gamma-Glutamyltransferase ; urine