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Biomedical subjects

I Noer

Publications and source records attributed to I Noer.

11 recordsLinked to original sources
PubMed1979

Effect of metabolic regulation on renal leakiness to dextran molecules in short-term insulin-dependent diabetics.

Renal clearance of dextran of two ranges of molecular size and glomerular filtration rate (GFR, 51Cr-EDTA) were measured in seven short-term insulin-dependent diabetics (mean age 25 years). Measurements were carried out in the same patient during good and poor metabolic regulation (plasma glucose, mean +/- SEM, 6.5 +/- 0.9 and 14.8 +/- 1.5 mmol/l, respectively). GFR was elevated in all patients during poor metabolic regulation (119 +/- 6 ml/min/1.73 m2, versus 99 +/- 2 ml/min/1.73 m2 during good control, p less than 0.01). The average renal clearance of dextran with molecular weights ranging from 25,000 to 35,000 and 35,000 to 45,000 increased during poor metabolic regulation from 14.8 +/- 0.8 to 19.8 +/- 1.8 ml/min/1.73 m2, and 5.2 +/- 0.3 to 6.8 +/- 0.6 ml/min/1.73 m2, respectively (p less than 0.05). The elevated GFR and renal dextran clearance found during poor metabolic regulation were normalized within one to three weeks of effective insulin treatment. This rapid reversibility can hardly be explained by the previously demonstrated enlargement in glomerular size and filtration surface area, since these alterations remain unchanged after more than one month of insulin treatment. The metabolic regulation did not influence the size-selective properties of the glomerular wall. Therefore, we suggest that the dominating mechanism involved in the GFR and renal dextran clearance alterations is functional, viz. increased filtration pressure.

Adolescent↗
PubMed1979

Evidence of active transport (filtration?) of plasma proteins across the capillary walls in muscle and subcutis.

Under slight lymphatic stasis (tilting the body 15 degrees) we measured the arrival of locally injected 131I-albumin in the plasma pool. From 30 min to 90 min after the injection the return rate was zero, i.e. local back transport in the two tissues studied, muscle and subcutaneous fat, is very small. Compared with a suggested steady state total 131I-albumin clearance of 1.7%/hour in the horizontal body position, we conclude that a maximum of 1% of the interstitial albumin can have a local transendothelial escape, i.e. can be handled by passive forces, such as diffusion and pinocytosis. Since passive flux is proportional to the concentration, and since the interstitial albumin concentration is about half the plasma concentration, then also diffusion and/or pinocytosis of albumin from the plasma is negligible in the resting normal human. We suggest that filtration through large leaks is the main mechanism for transendothelial protein transport.

Adipose Tissue↗
PubMed1978

Preoperative estimation of run off in patients with multiple level arterial obstructions as a guide to partial reconstructive surgery.

Preoperative measurements of direct femoral artery systolic pressure, indirect ankle systolic pressure and direct brachial artery systolic pressure were carried out in nine patients with severe ischemia and arterial occlusions both proximal and distal to the ingvinal ligament. The pressure-rise at the ankle was estimated preoperatively by assuming that the ankle pressure would rise in proportion to the rise in femoral artery pressure. Thus it was predicted that reconstruction of the iliac obstruction with aorta-femoral pressure gradients from 44 to 96 mm Hg would result in a rise in ankle pressure of 16--54 mm Hg. The actual rise in ankle pressure one month after reconstruction of the iliac arteries ranged from 10 to 46 mm Hg and was well correlated to the preoperative estimations. In conclusion, by proper pressure measurements the run-off problem of multiple level arterial occlusions can be evaluated. Thus the result of successful partial reconstruction can be assessed preoperatively.

Aged↗
PubMed1978

Kidney function in normal man during short-term growth hormone infusion.

Kidney function was studied in 9 normal males before and during a 2 h growth hormone (GH) infusion of 50 ng/kg/min. The following variables were measured during each 20 min clearance period: glomerular filtration rate, GFR, effective renal plasma flow, RPF (steady state infusion technique with urinary collections using [125I]iothalamate and [131I]iodohippurate), and urinary albumin and beta2-microglobulin excretion rates (radioimmunoassays). The GH infusion resulted in a 10-fold increase in plasma GH concentration. All the above mentioned variables remained practically unchanged during the infusion except for a small (-5%) but significant decrease in renal plasma flow (P less than 0.01). Our negative results contrast to the findings of increased GFR and RPF during prolonged GH administration and suggest that GH requires several hours or days for its renal effects to become manifest.

Adult↗
PubMed1978

Evidence of active transport (filtration?) of plasma proteins across the capillary walls in muscle and subcutis.

Under slight lymphatic stasis (tilting the body 15 degrees) we measured the arrival of locally injected I-albumin to the plasma pool. From 30 min. to 90 min. after the injection the return rate was zero i.e. local back transport in the two tissues studied viz.muscle and subcutaneous fat is very small. Compared to a suggested steady state total 131 I-albumin clearance of 1.7%/hour in the horizontal body position we conclude that maximally one percent of the interstitial albumin can have a local transendothetial escape i.e. can be handled by passive forces as is diffusion and pinocytosis. As passive flux is proportional to the concentration and the interstitial albumin comcentration is about half the plasma concentration then also diffusion and or pinocytosis from the plasma of albumin is negligble in the resting normal man. We suggest filtration through big leaks as the main mechanism for transendothelial protein transport.

Biological Transport, Active↗
PubMed1977

Subclinical ergotism.

The systolic blood-pressure at the ankle and the first toe was measured in 30 patients, mean age 42, who had taken ergotamine regularly for more than a year. With one exception, the patients had no symptoms or signs of arterial insufficiency in the limbs, but all had low-normal or abnormal foot systolic blood-pressures. In a group of 13 patients who stopped taking ergotamine the distal pressures rose significantly and from the ninth day were normal.

Adult↗
PubMed1977

Central and regional circulatory effects of adding arm exercise to leg exercise.

7 young, healthy, male subjects performed exercise on bicycle ergometers in two 20 min periods with an interval of 1 h. The first 10 min of each 20 min period consisted of arm exercise (38--62% of Vo2 max for arm exercise) or leg exercise (58--78% of Vo2 max for leg exercise). During the last 10 min the subjects performed combined arm and leg exercise (71--83% of Vo2 max for this type of exercise). The following variables were measured during each type of exercise: oxygen uptake, heart rate, mean arterial blood pressure, cardiac output, leg blood flow (only during leg exercise and combined exercise), arterio-venous concentration differences for O2 and lactate at the levels of the axillary and the external iliac vessels. Superimposing a sufficiently strenuous arm exercise (oxygen uptake for arm exercise greater than 40% of oxygen uptake for combined exercise) on leg exercise caused a reduction in blood flow and oxygen uptake in the exercising legs with unchanged mean arterial blood pressure. Superimposing leg exercise on arm exercise caused a decrease in mean arterial blood pressure and an increased axillary arterio-venous oxygen difference. These findings indicate that the oxygen supply to one large group of exercising muscles may be limited by vasoconstriction or by a fall in arterial pressure, when another large group of muscles is exercising simultaneously.

Adult↗
PubMed1976

Leg muscle blood flow during reactive hyperemia. Effects of different body positions, and of subatmospheric pressure.

In normal man at rest transition from the supine to the upright body position is accompanied by autoregualtion of the blood flow to tissues in the dependent extremities. In 11 young healthy males the influence of postural changes and external pressure changes on the blood flow in the anterior tibial muscle during reactive hyperemia was studied. The muscle blood flow was evaluated by means of the Xenon-133 wash-out technique. Transmural pressure changes in the resistance vessels were estimated by measuring the systolic blood pressure at ankle level, using the strain-gauge plethysmograph technique. The mean leg muscle blood flow increased from 48 ml - 100 g-1 - min-1 in a body position with the legs elevated 65 cm above heart level, to 101 ml - 100 g-1 - min-1 in the supine position, and to 151 ml - 100 g-1 - min-1 in a sitting position with dependent legs 70 cm below heart level. The muscle blood flows increased from 92 ml - 100 g-1 - min-1 at ambient pressure to 139 ml - 100 g-1 - min-1 at a subatmospheric pressure of -50 mm Hg. The differences were highly significant (P less than 0.001). Systemic blood pressure measured at heart level did not change during postural changes and external pressure changes. The post-ischemic muscle blood flow was found to increase with the increasing vascular transmural pressure. It is concluded that during reactive hyperemia the normal compensatory vaso-reactions can be inactivated, so that the vessels react passively to changes in the transmural pressure.

Adult↗
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

Transcapillary escape rate of albumin and right atrial pressure in chronic congestive heart failure before and after treatment.

The transcapillary escape rate of albumin (TERalb), i.e., the fraction of intravascular mass of albumin that passes to the extravascular space per unit of time, was determined from the disappearance of intravenously injected 125I-labeled human serum albumin during the first 60 minutes after injection in 10 subjects with chronic right heart failure. The investigation was repeated after sodium and water depletion. Before treatment TERalb was significantly elevated (mean 8.3 +/- 1.6% (SD)/hour, in comparison to values for normal subjects (mean 5.4 +/- 1.1%/hour, P less than 0.001). With treatment TERalb decreased significantly (mean 5.9 +/- 1.2%/hour, P less than 0.01). Right atrial pressure decreased from an average of 10 mm Hg to 6 mm Hg during treatment. A statistically significant, positive correlation was found between TERalb and right atrial pressure (r = 0.77, P less than 0.001). Our results best can be explained by increased filtration, mainly through the venous end of the microvasculature, due to the increased venous pressure in heart failure.

Adult↗