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S Andersen

Publications and source records attributed to S Andersen.

At least 91 records · Page 5Linked to original sources
PubMed1986

Laurate binding to human serum albumin. Multiple binding equilibria investigated by a dialysis exchange method.

Multiple binding of laurate (n-dodecanoate) to human serum albumin was studied by a kinetic dialysis method. With this method the concentration of unbound ligand can be determined by measuring the rate of exchange of radioactive label across a dialysis membrane under conditions of equilibrium. Determination of the rate constant of exchange, in the absence of albumin, revealed that laurate does not change its state of aggregation over a concentration range from 0.1 microM to 500 microM, indicating the prevalence of a monomer. Binding of laurate to albumin, at pH 7.5, 37 degrees C, was investigated through 220 determinations of binding equilibria in the range of 0-10 mol laurate/mol albumin, corresponding to a concentration range of unbound laurate from 1 nM to 0.1 mM. Binding data were analyzed in terms of stepwise binding. Considering the stochastic errors of the experimental data, we generated a variety of possible (equal goodness of fit) solutions to the stoichiometric binding equation. This analysis resulted in reasonably well-defined values for the first two step constants, with an indication of negative interaction. The variation of the higher step constants excluded any mechanistic conclusions, although the binding isotherms, defined by these varying sets of binding constants, fitted the experimental data well within a chosen probability limit.

Dialysis↗
PubMed1986

Warfarin binding to plasma albumin, measured in patients and related to fatty acid concentrations.

A method for determination of reserve albumin equivalent for binding of warfarin as previously described [1] has been used for assessing the influence of non-esterified fatty acid concentration (NEFA) on binding of warfarin to human serum albumin (HSA). Reserve albumin concentration can be used for calculation of the expected fraction of bound warfarin in serum. It is shown in vitro that binding of warfarin increases with added oleate up to 4 mol of oleate per mol of albumin and then decreases. Twenty-four patients on permanent warfarin treatment showed no correlation of serum albumin and reserve albumin concentrations (r = 0.10, P greater than 0.50) indicating that warfarin binding is governed by other factors. However, in the same patients there was a significant correlation between reserve albumin concentration and NEFA/HSA (r = 0.54, P less than 0.01). In one human volunteer changes of NEFA were provoked by strenuous work and it was found that reserve albumin concentration increased with NEFA concentration as expected from the in vitro findings (r = 0.90, P less than 0.001). Five uraemic patients on permanent warfarin treatment showed increasing reserve albumin concentration with increasing NEFA concentration induced by heparin. These findings indicate that, both in vitro and in vivo, the reserve albumin concentration for binding of warfarin and hence the free warfarin concentration is markedly influenced by NEFA concentration. This may add to the understanding of warfarin dose requirement during anticoagulant therapy.

Adult↗
PubMed1985

Spinal anaesthesia with 0.75% bupivacaine and 0.5% amethocaine in 5% glucose.

Three millititre of 0.75% plain bupivacaine and 0.5% amethocaine 3 ml in 5% glucose were used for spinal anaesthesia and compared in a double-blind study of 20 patients undergoing urological surgery. The onset time to maximum cephalad spread of sensory analgesia was approximately 45 min for bupivacaine and approximately 30 min in the amethocaine group (ns). The mean maximum spread of sensory analgesia was similar for both agents: T6-7 180 min after injection, although the cephalad spread of sensory analgesia with bupivacaine persisted for longer at a significantly higher level than that of amethocaine. Duration of sensory analgesia was significantly longer in the bupivacaine group from S3 to S5 and from T12 to L2 levels. Onset time to complete motor blockade of the lower limbs was similar for both agents. Nine of 10 bupivacaine patients and seven of the 10 patients receiving amethocaine had complete motor blockade of the lower limbs. Duration of motor blockade was significantly longer for all degrees in the bupivacaine group.

Aged↗
PubMed1985

Methylprednisolone half-life during simultaneous barbiturate treatment and mechanical hyperventilation of neurosurgical patients.

The pharmacokinetics of methylprednisolone sodium succinate (MP) were studied in six neurosurgical patients under intensive treatment with large doses of MP, barbiturates, and mechanical hyperventilation. The study showed a remarkable level of enzyme induction within 24 hours after starting treatment, when the first blood samples were taken. The half-life (t 1/2) for MP during barbiturate and hyperventilation therapy was found to be reduced by a mean 55% (p less than 0.01) in relation to the t 1/2 of MP when administered alone. Studies on the day after termination of barbiturate intake indicated a tendency for an increase in the t 1/2 of MP, but it was not significantly different from the pretermination assessment (p greater than 0.05). On the basis of this study it is not possible to determine if the change in t 1/2 alone is governed by enzyme induction or by a combination of this plus a change in the distribution and clearance of the steroid. The clinical implication of these findings is that patients who are undergoing steroid treatment and at the same time are sedated with barbiturates should have their MP dose increased in order to compensate for the marked reduction of t 1/2 of MP.

Adolescent↗
PubMed1983

[Not Available].

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Denmark↗
PubMed1982

Prognosis curves for patients with polycystic kidney disease.

In patients with polycystic kidney disease and in many patients with other chronic renal diseases kidney function decreases from year to year. When the increase in serum creatinine concentration is followed graphically, the time for dialysis/transplantation can be predicted long beforehand. Based on the course of azotaemia in 34 patients with polycystic disease prognosis curves have been prepared. By comparing the course of a patient with the average course of similar patients, additional information can be gained. A statistical method for making a prognosis curve for kidney function in end-stage polycystic renal disease is described.

Adult↗
PubMed1982

The effect of dietary protein content upon growth in a genetically heterogeneous population of mice.

The effect of different dietary protein contents (19.3%, 14.9%, 11.0% and 5.7%) on weight gain was investigated in a genetically heterogeneous population of mice. Significant difference in weight gain was found only in the early growth period and was due mainly to the reduced weight gain of mice fed the diet with the lowest protein content. Feeding the mice low protein diets during the growth period did not affect reproductive performance.

Aging↗
PubMed1981

Dose response studies in elderly patients subjected to epidural analgesia.

In 51 men, aged 60-87 years, subjected to lumbar epidural analgesia for transurethral resection of the prostate gland, the relationship between doses of 10, 15 and 20 ml mepivacaine 1.5 with adrenaline 1:200,000 and the extension of analgesia was studied. Three different postures during application of epidural analgesia were investigated (left lateral position, sitting position with the patient turned supine immediately after injection, and the sitting position with the patient turned supine 5 min after injection. The results indicate that posture did not significantly influence the extension of analgesia, which was found to be positively correlated to the volume of mepivacaine, and the segmental dose requirement was positively correlated to the volume injected. It is concluded that transurethral resection of the prostate gland in patients over 60 years old can be performed using mepivacaine 1.5% with adrenaline 1:200,000 injected in the lumbar epidural space. In some cases, doses of 15 and 20 ml provoked an unwanted extension of analgesia, reaching the upper thoracic segments.

Aged↗