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Biomedical subjects

B Eklund

Publications and source records attributed to B Eklund.

At least 109 records · Page 6Linked to original sources
PubMed1981

Comparison of two different immunosuppressive dosages of methylprednisolone in clinical renal transplantation.

In order to study the immunosuppressive effect of methylprednisolone, thirty cadaver kidney recipients where randomly allocated into two groups: the low dose control group and the high dose experimental group. In 12 patients in the control group a clinical rejection episode occurred within two weeks of the transplantation, 3 rejections were irreversible, whereas 7 patients rejected in the experimental group, there were no irreversible rejections. In the low dose group the clinical rejection occurred significantly earlier. Fine needle aspiration biopsies of the grafts showed that the number of macrophages infiltrating the graft was significantly lower in the experimental group. Increasing the dose of methylprednisolone given prophylactically can modify the number and severity of rejection episodes early after renal transplantation.

Adult↗
PubMed1980

Central and peripheral circulatory effects and metabolic effects of different prostaglandins given I.V. to man.

Cardiac output, heart rate, stroke volume, pressures in the brachial artery, right ventricle and pulmonary artery, forearm blood flow, and arterial concentration of FFA, lactate and glucose were measured in healthy male volunteers during i-v infusion of PGE1, PGE2, PGF2 alpha or 15-methyl PGF2 alpha in increasing doses. In accordance with previous findings PGE1 and PGE2 increased cardiac output by a vasodilating effect in the systemic and pulmonary vascular bed, probably in combination with an inotropic effect on the heart. 15-methyl PGF2 alpha had essentially the same cardiovascular effects as PGF2 alpha. They induced a slight increase in cardiac output due to effects on heart rate, while systemic vascular resistance was unchanged. Forearm vascular resistance increased and pressures in the pulmonary circulation rose, indicating a vasoconstriction in these vascular beds. Glucose concentrations was not affected nor were lactate concentrations, except for a slight decrease of unclear significance in the group receiving 15-methyl PGF2 alpha. FFA increased slowly in the same manner as seen spontaneously in fasting individuals. These data do not indicate direct metabolic effects of the prostaglandins studied when given i-v.

Adult↗
PubMed1980

Diagnostic evaluation of the in situ inflammatory response of renal allograft rejection.

Transplant aspiration cytology (TAC) may be performed daily from human renal allografts without risk to the graft or to the graft recipient. With TAC it is possible to accurately quantitate the onset, type, degree and duration of the inflammatory response of rejection, predict the course of rejection, and on certain occasions also visualise the rejection prior to the appearance of clinical signs. The method also provides a quantitative tool for the assessment of the effects of immunosuppressive and anti-inflammatory drugs on the composition of the in situ inflammatory infiltrate.

Biopsy, Needle↗
PubMed1979

Prostaglandins contribute to the vasodilation induced by nicotinic acid.

The significance of endogenously formed prostaglandins in the vasodilation induced by nicotinic acid (NIC) was investigated. The forearm venous plasma level of radioimmunoassayed PGE (R-PGE) and the forearm blood flow (FBF) were measured in 13 healthy male volunteers at rest and during infusion of NIC. Each subject was subsequently re-studied after pretreatment with the PG synthesis inhibitor, naproxen. In the absence of naproxen, NIC infusion resulted in an almost four-fold rise in the release of R-PGE and a 60% increase in FBF. Pretreatment with naproxen did not affect the basal release of R-PGE or the basal FBF but inhibited both the release of R-PGE and the increase in FBF following NIC. The data support the hypothesis that the vasodilating effect of NIC is largely dependent upon an increased vascular formation of PG.

Adult↗
PubMed1979

Non-invasive methods of the evaluation of obliterative disease of the subclavian or innominate artery.

The preoperative investigation of 25 patients referred for evaluation of subclavian artery obliteration is reported. Non-invasive methods were used prior to angiography to assess arm circulation and the direction of blood flow in the vertebral artery. A retrograde flow in one vertebral artery was found in 18 patients, but only 7 had symptoms judged to be caused by the reversal of flow. In only one patient was the arm circulation so impaired as to justify the diagnosis of arm claudication. A high frequency of carotid lesions was found on the angiograms. The report demonstrates that in cases of suspected subclavian steal and/or arm claudication due to a subclavian artery obliteration, non-invasive methods should be used to screen the patients before angiography. In many cases it will be found that symptoms cannot be attributed to steal or impairment of the arm circulation and therefore angiography is not indicated. However, in some cases signs of a coexistent carotid lesion may still necessitate angiography.

Adult↗
PubMed1979

Insulin and substrate exchange in the forearm during prolonged forearm work.

Forearm exchange of insulin and uptake of oxygen, glucose and free fatty acids (FFA) were studied during 120 min forearm work in six healthy male volunteers. At rest the arterial-deep venous difference of insulin was zero. At the onset of work release of insulin occurred, which continued at constant rate throughout the work despite unaltered arterial insulin concentration. Extractions of oxygen, glucose and FFA were of similar magnitudes at 120 as at 15 min work, while lactate release decreased with time. It is concluded that (1) a significant insulin release from muscle tissue or its vascular bed occurs and continues at undiminished rate during prolonged work, (2) a substantial amount must be bound in the tissue, unless local synthesis takes place and (3) despite this loss of insulin from the forearm no major change in glucose and FFA extraction occurs with duration of work.

Adult↗
PubMed1979

Dissociation of the effects of nicotinic acid on vasodilatation and lipolysis by a prostaglandin synthesis inhibitor, indomethacin, in man.

The effects of nicotinic acid on plasma free fatty acid (FFA) concentration and forearm blood flow were studied in seven healthy fasting volunteers with and without pretreatment by indomethacin to see if some effects of nicotinic acid are mediated by release of endogenous prostaglandin. 1 g of nicotinic acid per os decreased plasma FFA concentration to a lowest value of 1/4 of initial level and increased forearm blood flow four times. When the same dose of nicotinic acid was given after pretreatment with indomethacin, the blood flow increase was only 1/3 of that without indomethacin. Indomethacin did not alter the rapid initial decrease in plasma FFA, although the period of low FFA concentration was shortened and the rebound to supranormal concentration was abolished. Thus the vasodilatory effect of nicotinic acid seems to be mediated by release of endogenous prostaglandin while the inhibition of lipolysis by the drug is mainly produced by other mechanisms.

Adult↗
PubMed1979

Vascular access for haemodialysis with autogenous vein graft arteriovenous fistulas.

Nine autogenous vein grafts (AVG) have been used in nine patients to create arteriovenous fistulae for haemodialysis. All the patients lacked vessels for construction of a regular arteriovenous fistula. Three of the AVG failed during dialysis treatment 3, 10 and 14 months respectively following construction. Another AVG thrombosed but function was restored by thromboectomy. The same graft was later complicated by a false aneurysm and rupture but was then reconstructed with a vein patch. One AVG with a false aneurysm in the proximal anastomosis was repaired within six weeks.

Adult↗
PubMed1978

Blood flow in the resting forearm during prolonged contralateral isometric handgrip at maximal effort.

1. In earlier studies we have shown that muscle contraction performed as handgrip at constant force, one third of maximal voluntary contraction (MVC), induces a rapid vasodilation in the resting contralateral forearm which in all probability is neurogenically mediated, followed by a relative increase in resistance.2. The maintenance of contraction at one third MVC for 2 min requires continuously increasing effort because of fatigue, as also evidence by the e.m.g. The biphasic response of the vascular bed may then be related to the increasing intensity of somatomotor activation which is needed to maintain contraction force, or, alternatively, to differences in vasomotor activity on initiation of and continued muscle activity.3. To elucidate these two possibilities blood flow in the resting forearm was measured during contralateral handgrips at constant maximal effort for 6 min (in which case force will drop) and compared to handgrip at constant force, one third MVC, for 2 min.4. The flow reaction during prolonged contraction at maximal effort was similar to that induced by contraction at constant force with a marked transient lowering of vascular resistance, although maximal vasodilation tended to be more pronounced and occur earlier.5. The results indicate that the rapid decrease in vascular resistance is related primarily to the initiation of somatomotor activity, whereas continued muscle contraction produces a relative increase in vasoconstrictor activity irrespective of changes in contraction effort.

Adult↗
PubMed1978

The relation between carbohydrate extraction by the forearm and arterial free fatty acid concentration in man. I. Forearm work with nicotinic acid infusion.

To see if the magnitude of carbohydrate extraction by working skeletal muscle in man is inversely correlated with the arterial free fatty acid (FFA) concentration as in the heart, eighteen healthy men were studied during dynamic forearm work with and without nicotinic acid. The extraction or release of glucose, lactate and pyruvate was determined by the simultaneous sampling of blood from the brachial artery (a) and a deep vein (dv) of the active forearm. Nicotinic acid decreased the arterial FFA concentration from 498 +/- 53 to 134 +/- 12 mumol per litre plasma and this caused a decrease in calculated extraction of FFA. However, it did not affect the extraction of glucose, which was of a magnitude similar to one third of the oxidative metabolism in both situations. One of the possible reasons of this difference compared to the human heart muscle is that the exercising skeletal muscle may utilize stored substrate to a greater extent, which makes possible shifts in substrate utilized for oxidation without changes in substrate extraction. Another reason may be that FFA utilization covers a far smaller proportion of oxidative metabolism in skeletal than in heart muscle already before nicotinic acid.

Adult↗
PubMed1977

Differences in heparin-released lipolytic activity in the superficial and deep veins of the human forearm.

Various doses of heparin were given as a single injection into the brachial artery of each of twelve fasting healthy males. Plasma lipolytic activity was measured in samples obtained before and at frequent time intervals after heparin injection, in the artery and the deep and superficial veins of the same forearm. As little as 0.15 U heparin produced a rapid and detectable release of lipolytic activity in both deep and superficial veins. A series of tenfold increases in the dose produced correspondingly greater releases in the veins but the increments in the release were smaller than the increments in the dose. Three repeated 15 U doses of heparin, separated by 30 min, in the same subject gave a high degree of reproducibility of the release of lipolytic activity in both deep and superficial veins. 90% of the lipase activity in the vein was inhibited by 1 M NaCl. In all subjects the release of lipolytic activity was higher in the deep vein, which predominantly drains muscle, than in the superficial vein, which drains mostly subcutaneous tissues such as skin and adipose tissue. This indicates that muscle is a tissue of considerable importance as a source of post heparin plasma lipolytic activity.

Adipose Tissue↗