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Biomedical subjects

I Noer

Publications and source records attributed to I Noer.

35 records · Page 2Linked to original sources
PubMed1981

Supplementary angiography when lumbar angiograms fail to demonstrate the vessels to the leg.

The peripheral run-off arteries were insufficiently visualized due to occlusions in the aorto-iliac segments in studies of 10 patients (15 legs) in 183 consecutive aorto-femoral angiograms. Guided by a combination of the Doppler technique and fluoroscopy, the non-opacified and pulseless common femoral artery was catheterized. Angiography through this catheter usually showed patency of a part of the common femoral artery but occlusion of the superficial femoral artery. The deep femoral and crural arteries were well preserved. Intra-arterial pressure measurements showed larger pressure gradients along the occluded aorto-iliac segments in one-third of the patients with non-visualized leg arteries as compared with gradients in patients with similar proximal and distal occlusions but with good opacification of the leg arteries. In previous cases, non-visualization of the leg arteries was considered as representing non-reconstructable lesions by our vascular surgeons. The findings in the present study showed that in these patients surgical reconstruction of only the aorto-iliac segments will suffice to save the limb from amputation.

Angiography↗
PubMed1981

Multiple level arterial occlusions of the leg. Reliability of indirect thigh pressures in the assessment of proximal arterial obstruction.

19 patients with obstructive arterial disease both proximal and distal to the inguinal ligament were studied with segmental blood pressure recordings because reconstruction of the proximal lesion was considered. The common femoral pressure was measured intraarterially as well as with a 12 cm cuff placed as proximally as possible on the thigh. The proximal pressures measured by the two techniques were found to correlate well. Thus, the atraumatic cuff pressure technique is validated which can be of use in evaluating multilevel occlusions and the associated run off problem involved in partial proximal reconstruction.

Aorta↗
PubMed1980

The effect of glucagon infusion on kidney function in short-term insulin-dependent juvenile diabetics.

Kidney function was studied in nine, metabolically well controlled, short-term insulin-dependent male diabetics before and during glucagon infusion of 4 to 5 and 8 to 10 ng/kg/min. Glomerular filtration rate, effective renal plasma flow (steady-state infusion technique, with urinary collections, using 125I-iothalamate and 131I-iodohippurate), and urinary albumin and beta 2-microglobulin excretion rates were measured. The mean plasma glucagon concentration increased during infusion from 254 +/- 19 pg/ml to 440 +/- 31 pg/ml (low dose) and 730 +/- 52 pg/ml (high dose). Glomerular filtration rate increased in all subjects from 133 +/- 5 before the glucagon infusion to 141 +/- 4 with the low dose, and 148 +/- 7 ml/min/1.73 m2 with the high dose (p < 0.01). The increase in glomerular filtration rate correlated with the rise in plasma glucagon concentration (r = 0.67; p < 0.01). Renal plasma flow increased from 530 +/- 21 before the glucagon infusion to 555 +/- 20 with the low dose and 572 +/- 29 ml/min/1.73 m2 with the high dose (p < 0.01). Urinary beta 2-microglobulin excretion rate rose from 5.8 +/- 1.0 before infusion to 8.7 +/- 1.7 with the low dose, and 17.9 +/- 5.7 micrograms X 10(-2)/min with the high dose (p < 0.01). Urinary albumin excretion remained unchanged during the glucagon infusion. These results suggest that glucagon may contribute to the reversible elevation of glomerular filtration rate typically found in poorly regulated insulin-dependent diabetics, but not to the moderate elevation found in well controlled diabetics.

Adolescent↗
PubMed1980

Classification of peripheral occlusive arterial diseases based on symptoms, signs and distal blood pressure measurements.

Systolic blood pressures at toe and ankle were measured in 459 consecutive patients with occlusive arterial disease. Fifty-eight per cent had intermittent claudication with arterial disease of all degrees of severity. Seventeen per cent complained of rest pain having toe systolic pressures below 30 mmHg, half had arterial lesions proximal to the groin. None had diabetes. Fourteen per cent non-diabetic patients had chronic ulcerations on the foot with arterial lesions similar to those in patients with rest pain. Eleven per cent diabetic patients with chronic ulcerations had less pronounced occlusive arterial disease which was located distally on the legs. A classification in three groups is suggested: (1) ischemia only during exercise; (2) ischemia at rest with or without ulcerations: and (3) diabetics with chronic ulcerations.

Adult↗
PubMed1980

Minimal distal pressure rise after reconstructive arterial surgery in patients with multiple obstructive arteriosclerosis.

Forty-one reconstructive procedures were carried out in thirty-five consecutive patients. Average age was 63 years (range 46-75). Thrombendarterectomy or by-pass procedures were carried out in twenty-nine proximal and twelve femoropopliteal reconstructions. Twenty-three patients had rest pain fifteen had ischemic ulcers. The preoperative median pressure index (per cent of arm systolic pressure) was 10% on the 1st toe. At the 10th postoperative day the median toe pressure rose to 25%. A further rise took place at the one month control to 30% which was unchanged throughout the study. All patients with a persistent postoperative toe pressure above 20% of arm systolic pressure were ultimately relieved from rest pain and chronic ulcers.

Adult↗
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↗