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Biomedical subjects

J Holm

Publications and source records attributed to J Holm.

At least 217 records · Page 12Linked to original sources

Hemodynamic findings before and after resection of abdominal aortic aneurysm.

A preoperative and postoperative hemodynamic study was performed in 20 consecutive patients undergoing elective resection of abdominal aortic aneurysm. Screening for venous thrombosis and pulmonary embolism with 125I uptake test, measurements of maximal venous emptying and pulmonary perfusion scintigraphy were also done before and after the operation. Only five patients complained of intermittent claudication preoperatively, but the laboratory investigations revealed signs of peripheral arterial insufficiency in 15 cases. Maximal venous emptying from the legs was markedly decreased on the first postoperative day and remained significantly below normal on the sixth day. Signs of postoperative thromboembolism appeared in eight patients. These patients did not differ from the others in regard to the pattern of maximal venous emptying. In the three-year follow-up period, the calf blood flow and the ratio of systolic toe pressure to systemic systolic blood pressure were further decreased, despite significant rise in systemic blood pressure.

Aged↗

Quantitative and qualitative effects of N10-methylfolate on high-affinity folate binding in human leukocytes.

N10-methylfolate acted as a potent competitive inhibitor of high-affinity [3H] folate binding in human leukocytes, while methotrexate had no effect. Furthermore, folate binding changed into a non-cooperative type in the presence of N10-methylfolate. Hence, in qualitative and quantitative respects, the substrate specificity characteristics of leukocyte folate binding resemble those of other high-affinity folate binding systems.

Binding, Competitive↗

Improved survival in multiple myeloma with combination chemotherapy and plasmapheresis.

The relation of different cytostatic regimens and plasmapheresis to survival time was studied in patients with stage III myeloma. The median survival time for 23 melphalan-prednisolone treated patients was 9 months. Nine melphalan-prednisolone treated patients, who were in addition treated with plasmapheresis survived longer (median 23 months), but the difference was not significant. Twenty-five patients, treated with plasmapheresis and cytostatic combination (melphalan, cyclophosphamide, BCNU, vincristine, prednisolone) survived significantly longer, for 61 months (median). Cytostatic combination therapy seems to prolong survival in stage III myeloma. Plasmapheresis may also have a favourable effect.

Adult↗

Dependence of aggregation and ligand affinity on the concentration of the folate-binding protein from cow's milk.

Ultracentrifugation and gel-filtration studies showed that the folate-binding protein from cow's milk possessed a remarkable aggregation tendency at pH 7.4. Aggregation was enhanced in the presence of folate which suggested an interrelationship between the mechanisms of ligand binding and polymerization. The degree of polymerization increased with increasing concentrations of binding protein. Thus, while the monomer prevailed at 1 nM, a polymer composed of more thn 32 monomers was formed at 130 microM. Two characteristics of folate binding, i.e., Scatchard plots that were convex upward and a ligand affinity that was inversely proportional to the concentration of binding protein, could be interpreted in terms of ligand binding to a polymerizing system in which the polymerization equilibria affect the ligand affinity.

Animals↗

Relationship between muscle morphology and metabolism in obese women: the effects of long-term physical training.

To evaluate the relationships between changes in muscle morphology and metabolic adaptation to physical training in obesity, twenty obese women were subjected to a physical training programme with three sessions a week for 3 months. Physical training resulted in lowering of plasma insulin and improved glucose tolerance. Neither body weight nor body fat changed. With physical training the percentage distribution of fast twitch oxidative (FTa) muscle fibres (m vastus lateralis) increased (from 30.3 +/- 5.1% to 35.2 +/- 4.8%, P less than 0.05) and that of fast twitch glycolytic fibres decreased (from 18.3 +/- 6.6 to 5.8 +/- 4.8%, P less than 0.05). The number of capillaries increased, mainly around slow twitch (ST) fibres (from 4.5 +/- 0.6 to 5.8 +/- 0.8, P less than 0.01) and fast twitch oxidative (FTa) fibres (from 3.9 +/- 0.7 to 4.7 +/- 0.8, P less than 0.01). The activities of oxidative enzymes (cytochrome-c-oxidase and citrate synthase) increased (P less than 0.05) while those of glycolytic enzymes (phosphofructokinase and hexokinase) decreased after physical training (P less than 0.01). Significant negative correlations between plasma insulin and number of capillaries in contact with ST fibres (r = 0.80, P less than 0.001) and FTa fibres (r = 0.62, P less than 0.001) were found before training. The capillary density around those fibres could predict 80% of the explained variance of plasma insulin levels (P less than 0.001). The changes of glucose concentration after training could be predicted by observed changes in enzyme activities. The strong associations between muscle morphology and capillarization and enzyme activities and glucose and insulin concentrations and their changes after training suggest an important regulatory role of muscle which warrants further studies.

Adult↗

High-affinity folate binding in leukocyte lysate from normal subjects: effect of concentration of binding protein, temperature and pH.

Folate binding in lysate prepared from leukocytes containing large amounts of the folate-binding protein was studied in equilibrium dialysis experiments (pH 7.4, 37 degrees C). Binding displayed positive cooperativity, and the binding affinity increased with decreasing concentration of binding protein (affinity constants in the range of 5 X 10(9) l/mol to 7 X 10(10) l/mol). Both phenomena could be interpreted in terms of ligand binding to a polymerizing system where the affinity of ligand for the oligomer is greater than its affinity for the polymer prevailing at high concentrations of the binding protein. Binding affinity was decreased at a low temperature (7 degrees C) and particularly at pH 5.0 where positive cooperativity also disappeared. The binder (Mr approximately 25,000-30,000) eluted in the front effluent after DEAE-Sepharose CL-6B chromatography of the lysate at pH 6.3.

Animals↗

Inheritance of high leukocyte folate binding activity. Relationship between folate binding in leukocytes and serum.

Folate binding was determined in leukocyte lysates from relatives of three persons whose leukocytes contained large amounts of folate binding protein. A pedigree analysis showed that high leukocyte folate binding activities occurred with great frequency in these families suggesting a dominant mode of inheritance. Folate binding in serum varied within narrow limits (0.2-0.5 nmol folate/l serum) in persons with leukocyte folate binding activities less than 0.8-1.0 nmol folate per 10(9) cells. A shift to a higher level of serum folate binding (greater than or equal to 1.0 nmol/l serum) was, however, observed at leukocyte folate binding activities above that value.

Carrier Proteins↗

Characteristics of high-affinity folate binding in human leukocytes.

High-affinity binding of [3H]folate in leukocytes from normal subjects was studied in equilibrium dialysis experiments (pH 7.4, 37 degrees C). Binding displayed positive cooperativity, and the binding affinity increased with decreasing concentration of the binding protein. Both phenomena could be interpreted in terms of ligand binding to a polymerizing system where the affinity of ligand for the oligomer is greater than its affinity for the polymer prevailing at higher concentrations of the binding protein.

Carrier Proteins↗

Melphalan-related leukemia in multiple myeloma.

Five patients with multiple myeloma ending in acute leukemia are described. The preleukemic phase was characterized by anemia, leukopenia and/or thrombocytopenia. The incidence of acute leukemia in myeloma was calculated to be 6%. Melphalan therapy for more than two years increased the incidence to 14%. All patients who developed leukemia had received a total melphalan dose of at least 1 100 mg.

Acute Disease↗

Evaluation of serial bone X-ray examination in multiple myeloma.

Fifteen patients with multiple myeloma stage III were treated with a combination of cytostatics and plasmapheresis in a sequential trial running for 60 weeks. Thirteen patients showed clinical improvement and ten a reduction of their myeloma protein by at least 50%. Bone X-ray examination was performed every 15 weeks. Progression of bone lesions was seen in one patient, whereas the radiographic picture was unchanged in the others. It is concluded that bone X-ray, although essential in the diagnosis and staging of multiple myeloma, is not suitable for the monitoring of patients during treatment.

Aged↗

Thermography and phlebography in the detection of incompetent perforating veins.

In 22 patients with deep venous insufficiency thermography performed at rest and immediately after exercise was compared with conventional ascending phlebography. Thermography was found to have a high sensitivity in detecting incompetent perforating veins, while the specificity was low. The non-invasive thermography is an attractive technique for preoperative detection of perforating veins.

Adult↗

Insulin sensitivity and glucose uptake in the course of surgical treatment for valvular aortic stenosis.

The dose-response relationship between plasma insulin and systemic glucose uptake was studied before, one hour after and 6 months after valvular surgery in 11 patients with valvular aortic stenosis. The immediate effect of valvular surgery was a dramatic rightward shift of the dose-response curve and a decrease in glucose uptake at peak insulin activity. From a comparison between the preoperative and the 6-month postoperative dose-response curves it is concluded that the patients had adapted metabolically to the preoperative haemodynamic situation with increased insulin sensitivity.

Aortic Valve Stenosis↗

Effect of valvular aortic stenosis on insulin sensitivity.

18 patients with valvular aortic stenosis were given an i.v. glucose tolerance test and an i.v. insulin tolerance test before and 4-36 months after valve replacement. Insulin and C-peptide response to the glucose challenge was smaller preoperatively whereas the glucose response was the same pre- and postoperatively. The effect on blood glucose of the i.v. insulin challenge was more pronounced preoperatively. It is concluded that insulin sensitivity was increased preoperatively and it is suggested that this was a metabolic adaptation to the haemodynamic situation in aortic stenosis, which may have implications for preoperative glucose-insulin-potassium treatment.

Aged↗

Detergent activation of the binding protein in the folate radioassay.

A minor cow's whey protein associated with beta-lactoglobulin is used as binding protein in the competitive radioassay for serum and erythrocyte folate. Seeking to optimize the assay, we tested the performance of binder solutions of increasing purity. The folate binding protein was isolated from cow's whey by means of CM-Sepharose CL-6B cation-exchange chromatography, and further purified on a methotrexate-AH-Sepharose 4B affinity matrix. In contrast to beta-lactoglobulin, the purified protein did not bind folate unless the detergents cetyltrimethylammonium (10 mmol/L) or Triton X-100 (1 g/L) were present. Such detergent activation was not needed in the presence of serum. There seems to be a striking analogy between these phenomena and the well-known reactivation of certain purified membrane-derived enzymes by surfactants (lipids/detergents).

Detergents↗