ISSN:1784-3286    

DOI:10.1080/22953337.1980.11718774

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor

摘要:

SummarySerumβ2microglobulin (β2m) levels were determined together with serum creatinine and inulin clearance in 500 patients with various degrees of renal insufficiency, excluding patients with connective tissue disorders or lymphoproliferative disorders. The logarithmic relationship observed between Sβ2m and inulin clearance, was best fitted to experimental data whenβ2m values below and above 245 mg/l were treated separately. The plasma turnover of125Iβ2m was studied in two healthy adults, two anuric patients (one of them without kidneys) and eight patients with various degrees of renal insufficiency. Results were analyzed according to a bicompartmental model. The fractional metabolic rate was positively correlated with inulin clearance and little (<3.5 %) extrarenal catabolism was demonstrated. The half-life ofβ2m in intravascular compartment varied from 107 min. in normals to more than 39 hrs in the anephric patient.

ISSN:1784-3286    

DOI:10.1080/22953337.1980.11718773

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor

摘要:

Summaryβ2m is a low molecular weight protein of 100 amino-acids which is non-covalently associated with the heavy Chain of HLA-A, B and C antigens on the surface of neariy all cells, with the exception of erythrocytes. Its amino-acid sequence and three dimensional structure bear a striking similarity with domains of heavy and light chains of immunoglobulins and with HLA antigens.β2m is released from cell surface into biological fluids where it is found mostly as free monomer. Lymphocyte activation by mitogens, allogeneic cells or specific antigens, as well as leukocyte interferon administration, enhanceβ2m release. The kidney represents the major site ofβ2m catabolism.β2m is filtered through the glomeruli and serumβ2m levels are negatively correlated with the glomerular filtration rate. About 99 % of filteredβ2m is reabsorbed and catabolized by proximal tubular cells. Changes in serumβ2m concentrations can be due either to reduced glomerular filtration rate or to increased synthesis at it the case in malignant diseases, lymphoproliferative disorders or chronic inflammatory diseases (systemic lupus erythematosus, rheumatoid arthritis, Sjögren's syndrome, sarcoidosis, inflammatory bowel diseascs, hepatitis or cirrhosis). Increased urinary excretion reflects primarily defective tubular reabsorption and catabolism; it represents the hallmark of primary tubulo-interstitial disease.

ISSN:1784-3286    

DOI:10.1080/22953337.1980.11716549

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor

摘要:

Summaryβ2-microglobulin excretion in 24 hour urine collections were studied in patients with upper and lower urinary tract infections and the results compared with normal subjects. In upper U.T.I. the 24 hour excretion ofβ2m was significantly increased as the values in patients with only a cystitis were completely normal. There was no overlap between the 2 groups. Preliminary studies have been performed to compare the values ofβ2-m excretion with immunofluorescence of antibody coated bacteria for the diagnosis of pyelonephritis.

ISSN:1784-3286    

DOI:10.1080/22953337.1980.11716550

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor

摘要:

β2-microglobulin, a low-molecular-weight protein, is constantly produced in the body, passes freely the glomerular membrane and is almost fully reabsorbed and catabolized by the proximal tubular cells.The relativeβ2-microglobulinicreatinine clearance is presumed to be an indicator for proximal tubular reabsorption and is measured in 48 infants and children.A 100-fold decrease during infancy and early childhood is found, representing a maturation of handling low-molecular-weight proteins by the proximal tubular cells.Since almost noβ2-microglobulin was detectable in urine with pH<6.0 and the relativeβ2-microglobulin/creatinine clearance scattered 4 to 16-fold in consecutive 6-hours urine collections, a 24-hour urine collection with oral bicarbonate loading to obtain urine pH≥6.0 is necessary to avoid erroneous interpretation.The relative flemicroglobulin/creatinine clearance is a sensitive non-invasive method to study and evaluate renal tubular damage or dysfunction in infancy and childhood.

ISSN:1784-3286    

DOI:10.1080/22953337.1980.11716559

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor

摘要:

SummarySerum and urineβ2m levels were determined in 63 haemodialyzed patients and sequentially in 76 recipients of a renal allograft. Elevated stable serumβ2levels were observed under haemodialysis (12.5 to 92 mg/1). Patients with residual diuresis were shown to excrete high amounts ofβ2m (up to 150 mg/24 hrs) and to have lower serum levels than anuric patients. Stable serum levels in anephric patients indicate a marked reduction ofβ2m biosynthesis or an extrarenal catabolism ofβ2m in such cases. After transplantation, variations of serumβ2, usually paralleled that of serum creatinine, except in two circumstances : 1/ in patients with initial oliguric renal insufficiency, a decrease of serum km indicates the viability of the transplant whereas a raise of serumβ2m may represent the only sign of a rejection episode; 2/ in patients with bacterial, fungal or viral infections serumβ2m may increase without changes of serum creatinine. Sequential determinations of urinaryβ2m may reveal peaks of excretion (>10 [kg/min) corresponding to acute proximal defects by immunological damage of the transplant. Such peaks can occur prior to or associated with typical rejection crises, or independently from them.

ISSN:1784-3286    

DOI:10.1080/22953337.1980.11716560

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor

摘要:

SummaryThe total content ofβ2μin human renal cortex has a mean value of 3±1μg/g and canbefound as well in the hydrosoluble protein fraction as in the solubilized one with a ratio of 0.8. The tissues with pronounced nephroangiosclerosis contain lessβ2μ(2.1±0.5μg/g) and those with chronic pyelonephritis a significant higher content (3.8±1.2μg/g). The ratiobetweenhydrosoluble and the solubilized fractions is different with a value of 0.75 in the tissues with chronic pyelonephritis and 1.2 in those with nephroangiosclerosis. When the results are expressed per mg of total protein, only the values in the tissues with chronic pyelonephritis (98±33 ng/mgP) are statistically significant different from the normal tissue (59±22 ng/mgP) and from the tissues with nephroangiosclerosis (44±14 ng/mgP). Leucocytic infiltrations or saturation by a deficient turnover of the pw, may explain the difference.

ISSN:1784-3286    

DOI:10.1080/22953337.1980.11717175

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor