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Biomedical subjects

C E Mogensen

Publications and source records attributed to C E Mogensen.

28 records · Page 2Linked to original sources
PubMed1977

Studies on the mechanism of renal tubular protein reabsorption.

Amino acids and derivatives were injected intravenously in normal man and the effect on the urinary excretion of albumin, free light chains and beta-2-microglobulin determined. From the results we hypothesise that the initial event in normal protein reabsorption is binding between a free positive amino- or guanidino-group of the protein molecule and a negative site on the tubular cell surface. This initial event in the reabsorption process is impeded by molecules containing similar charged groups (arginine, ornithine, lysine, EACA and Cyclocaprone). Using high doses of lysine, complete or near-complete inhibition of tubular protein reabsorption is obtained. The glomerular filtration rate in preliminary experiments is found to be of the order of 300 microgram/min for albumin.

Albumins↗
PubMed1976

The effect of metabolic regulation on microvascular permeability to small and large molecules in short-term juvenile diabetics.

The microvascular permeability to small and large molecules was studied during good and poor metabolic regulation in ten short duration juvenile diabetics. The following variables were measured; daily urinary albumin and beta2-microglobulin-excretion rates, whole body transcapillary escape rate of albumin (TER), glomerular filtration rate (GFR), capillary filtration coefficient (CFC), and capillary diffusion capacity (CDC). The urinary albumin and beta2-microglobulin concentration were measured by sensitive radioimmunoassays; TER was detemined from the initial disappearance of intravenously injected 125I-labelled human serum albumin; GFR was measured on the forearm by straingauge plethysmography and CDS for 51Cr-EDTA clearance; CFC was measured on the forearm by straingauge plethysmography and CDC, for 51Cr-EDTA was determined in the jyperaemic anterio tibial muscle by the local clearance technique. All the above mentioned variables, except CDC, were significantly increased during poor metabolic regulation, indicating a functional microangiopathy. The mechanisms of these alterations appear to be increased filtration pressure in the microcirculation and/or increased porosity of the microvasculature. The findings of increased microvascular albumin passage are compatible with the hypothesis that the organic - histologicallly demonstrated - diabetic microangiopathy is a long-term effect of periods of increased extravasation of plasma proteins, with subsequent protein deposition in the microvascular wall, i.e. the concept to plasmatic vasculosis.

Adolescent↗
PubMed1976

Progression of nephropathy in long-term diabetics with proteinuria and effect of initial anti-hypertensive treatment.

The rate of progression of nephropathy was studied in 6 young male diabetics with intermittent proteinuria (Albustix) and in 10 young male diabetics with constant proteinuria by measuring glomerular filtration rate (GFR), renal plasma flow (RPF), and urinary albumin excretion by exact techniques. Albumin excretion was elevated in both the recumbent and the erect position in patients with intermittent proteinuria. GFR and RPF were at the same level as in diabetics without proteinuria, and no deterioration in renal function was noted during a mean control period of 32 months. In the patients with constant proteinuria the fall rate during a mean period of 33.6 months for GFR and RPF was 0.91 ml/min/month +/- 0.68 (S.D.) and 4.38 ml/min/month +/- 3.23 (S.D.) respectively. Initial fall rate in GFR correlated well with long-term fall rate, both of which were studied in 7 patients. In the same patients there was a positive correlation between the fall rate in GFR and diastolic blood pressure as well as albumin clearance. In 8 patients with constant proteinuria and mean blood pressure of 159/101 mmHg, antihypertensive treatment was started with propranolol alone or combined with hydralazine and furosemide. During a treatment period of 47 days blood pressure was reduced to 143/93 mmHg, and in the same period urinary albumin excretion was reduced significantly from a mean value of 3547 mug/min to 2414 mug/min (P less than 0.01). Further control studies will clarify whether end-stage of renal insufficiency will be postponed by antihypertensive treatment.

Adolescent↗
PubMed1976

Effect of antihypertensive treatment on urinary albumin excretion, glomerular filtration rate, and renal plasma flow in patients with essential hypertension.

In 20 patients with essential hypertension the urinary albumin execretion, glomerular filtration rate (GFR),and renal plasma flow (RPF) were examined before and after antihypertensive treatment. Albumin excretion measured by radioimmunoassay was increased before treatment, and there was a significant fall during treatment. In patients responding well to therapy (diastolic pressure below 100 mm Hg), albumin excretion was significantly lower than in patients responding poorly to therapy. There was a positive correlation between albumin excretion before treatment and diastolic pressure during treatment, indicating that the albumin excretion rate may be used to predict the result of antihypertensive treatment. Patients with excretion rates below 25 mug/min generally respond well to the treatment used. No definite changes in GFR and RPF were found during treatment, and there was no correlation between albumin excretion and GFR and RPF. It is suggested that the increased albumin excretion in essential hypertension is due both to functional and morphological alterations in the glomerulus, namely increased glomerular filtration pressure and vascular damage.

Aged↗
PubMed1976

Renal function changes in diabetes.

The present studies show that a number of functional abnormalities are present in the kidney in early diabetes, especially during poor regulation. Normalization of these functions and changes in renal and glomerular size are found during complete diabetes control. The results further support the idea that great efforts should be made to maintain the best possible control situation in diabetic patients. Our studies also indicate that antihypertensive therapy may be beneficial for young, proteinuric diabetics and may postpone the stage of renal insufficiency.

Antihypertensive Agents↗
PubMed1975

Increased urinary excretion of albumin, light chains, and beta2-microglobulin after intravenous arginine administration in normal man.

Infusion of 60 g of arginine in six healthy men over a 40-50 min period caused a 16-fold increase in the excretion-rate of albumin from 8-6 to 142-4 mug/min. After injection of 3, 6, 9, and 12 g of arginine the mean albumin-excretion rate of another six normal subjects rose from 5-8 mug/min to 9-4, 13-2, 21-6, and 33-9 mug/min, respectively. Excretion of light chains of immunoglobulin increased from 5-5 mug/min to 18-0, 30-0, 40-5; and 52-0 mug/min, respectively, and the excretion rate of beta2-microglobulin increased from 0-092 mug/min to 2-97, 9-23, 16-39, and 25-71 mug/min. Thus a clear dose response pattern was found. The results strongly suggest that the mechanism behind the arginine-induced protein excretion is an inhibition of tubular reabsorption.

Albuminuria↗
PubMed1975

Increased kidney size and glomerular filtration rate in untreated juvenile diabetes: normalization by insulin-treatment.

Glomerular filtration rate (GFR), renal plasma flow (RPF) and roentigenographic kiendy size were measured in six newly diagnosed male diabetics with a mean age of 25 years. Glomerular filtration rate was elevated before treatment to the same extent as found previously. A significant fall in both kidney size and glomerular filtration rate was found after treatment with insulin for 3 months. These results support further the concept that there is a basal connection between enlarged kidneys and the elevated GFR of early diabetes.

Diabetes Mellitus, Type 1↗
PubMed1975

Urinary albumin excretion during exercise in juvenile diabetes. A provocation test for early abnormalities.

Urinary albumin excretion during exercise was measured with a radioimmunological method in a group of 13 young male diabetic patients and in a comparable control group. The duration of diabetes was 2-18 years; they had no proteinuria (Albustix¿) and no other signs of renal disease. There was no difference in the basal albumin excretion. In the diabetics the average albumin excretion was doubled during exercise at 600 kpm/min for 20 min, from 9.1 mug/min to 18.7 mug/min (P less than 0.005). No significant change was seen in the controls. These results strongly suggest that abnormal glomerular filter properties are present in patients with relatively short duration of diabetes - that is, in patients who are known to have thickened glomerular basement membrane. The exercise provocation test may be useful in other fields of renal pathophysiology.

Adult↗
PubMedDate not supplied

Evaluation of a dipstick test for microalbuminuria in three different clinical settings, including the correlation with urinary albumin excretion rate.

UNLABELLED: A dipstick test for microalbuminuria was compared with urinary albumin excretion and urinary albumin concentration. Elevated urinary albumin excretion was defined as > 30 mg/24 h, elevated urinary albumin concentration in early morning urine as = > 20 mg/l and sticks = > 20 mg/l were considered positive. 1,071 samples with urinary albumin concentration 20-200 mg/l from 258 diabetic subjects were evaluated in three settings: I. 3 trained nurses testing samples from day-clinic diabetic patients. Sticks v.s. urinary albumin excretion sensitivity 86%, specificity 97%, predictive value of negative test 97%, correlation coefficient 0.79. Values for same setting but v.s. urinary albumin concentration were almost identical. II. 1 laboratory technician testing not-hospitalised diabetic patients: Sticks v.s. urinary albumin concentration: sensitivity 91%, specificity 85%, predictive value of negative test 95%, correlation coefficient 0.82. III. 58 general practitioners testing not-hospitalized diabetic patients: Sticks v.s. urinary albumin concentration: sensitivity 66%, specificity 92%, predictive value of negative test 83%, correlation coefficient 0.70. CONCLUSIONS: In the hands of trained nurses and laboratory technician the Micral-Test showed good correlation with urinary albumin excretion and urinary albumin concentration for day-clinic and not-hospitalized patients and can be recommended as a screening tool. General practitioners obtained a lower sensitivity probably due to lack of experience and incorrect handling of the sticks leading to systematical errors. Training in the use of the stick must be emphasized, since under such circumstances the results are satisfactory.

Adolescent↗