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Biomedical subjects

A Magnusson

Publications and source records attributed to A Magnusson.

At least 127 records · Page 7Linked to original sources
PubMed1985

Kinetics and dynamics of disopyramide and its dealkylated metabolite in healthy subjects.

The kinetics and dynamics of total and free (unbound) disopyramide (D) after dosing with D, 1.5 and 2 mg/kg iv, were compared with those of the dealkylated metabolite (MND) after dosing with MND, 0.5 and 1.5 mg/kg iv, in six healthy subjects. Dynamic parameters included ECG with measurement of the QT interval corrected for heart rate (QTc), systolic time intervals, vitamin C-stimulated saliva secretion, pupil size, and maximum accommodation capacity. Mean values of total clearance, apparent volume of distribution, and elimination t1/2 of MND were 5.9, 2.3, and 0.4 times those of total D, respectively. D significantly prolonged the QTc and systolic time intervals and induced transient inhibition of stimulated saliva secretion. In contrast, MND induced no substantial change in either the QTc or systolic time intervals, but did induce more persistent inhibition of salivary secretion. If anticholinergic potency is determined as the degree of inhibition of stimulated saliva flow per plasma concentration unit, MND was three times as potent as its parent when measured at maximum inhibition. There were no consistent drug effects on the ocular parameters. The effect of D on QTc correlated with both total and free plasma concentrations. Furthermore, its transient salivary inhibitory effect paralleled its initial rapid decline in plasma concentration. There was no relationship between the MND plasma concentration and its salivary inhibitory effect. We conclude that disopyramide significantly affected the QTc and systolic time intervals in healthy subjects, while MND in a similar dose had no such effects. MND more strongly inhibited stimulated saliva flow, indicating a more potent anticholinergic effect than D.

Adult↗
PubMed1985

Skiing injuries in children: lower leg fractures.

A study was made of 113 children who sustained a lower leg fracture during downhill skiing. The age distribution showed a peak between 4 and 7 years in both sexes, and boys had another peak in their teens. Three of four patients were beginners. To a large extent, they had had their bindings adjusted in ski shops. Three of four bindings did not release at the time of the accident. Spiral fractures in the shaft or distal metaphysis of the tibia predominated (73%); the incidence of concomitant fibular fracture was low. The degree of malalignment was generally small. The results of treatment, which was generally conservative, were good, 7% of the patients having minor sequelae 1-3 years after the accident. To reduce the risks in children's downhill skiing, the following measures seem important: intensified training during the beginner stage; increased supervision by parents and in ski schools; development of children's release bindings and testing methods; and adequate instruction of personnel in ski shops.

Adolescent↗
PubMed1985

Ultrafiltration compared with equilibrium dialysis in the determination of unbound phenytoin in plasma.

Protein binding of phenytoin (PHT) was studied in 36 patients with normal kidney function and six uremic patients. We compared a newly introduced ultrafiltration (UF) technique (EMIT Free Level System I) for measuring unbound PHT in plasma with an equilibrium dialysis (ED) method. The precision of the UF method was satisfactory (the CV within samples was 4.2%, and between days, 3.4%). PHT concentrations were measured with both homogeneous enzyme immunoassay and high performance liquid chromatography using plasma samples from epileptic patients. The values obtained agreed well. Unbound concentrations of PHT determined by the UF technique and ED were identical in both normal and uremic plasma obtained from patients under treatment. Unbound concentrations of PHT correlated significantly to total concentrations in both groups of patients. The investigated UF technique thus appears to be accurate for measuring unbound concentrations of PHT in plasma. Controlled clinical studies are required to show that this is a cost-effective clinical service.

Blood Proteins↗
PubMed1985

Cyclosporine plasma levels in renal transplant patients. Association with renal toxicity and allograft rejection.

In 69 renal allograft recipients the highest-tolerated dose was given with respect to clinical events but without respect to the CsA plasma level (CsA-PL). The CsA dose was gradually decreased during the first 6-12 months after transplantation, and in some patients even later. The CsA dose after 12 months was 5-8 mg/kg/day and after 18 months 4-6 mg/kg/day, resulting in CsA-PL of 85-140 ng/ml and less than 50-110 ng/ml, respectively. CsA side-effects were usually seen in patients with high CsA-PL, but they were also encountered at levels normally seen in patients without toxicity. In the individual patient, acute CsA nephrotoxicity was associated with a significant rise in CsA-PL. In patients with acute nephrotoxicity a reduction of the CsA dose (mean 24%) was necessary to regain satisfactory renal function. All patients with several consecutive CsA-PL above 1000 ng/ml had hepatotoxicity or nephrotoxicity, or both, associated with severe morbidity and mortality. No difference was found between CsA-PL during acute rejection and during good renal function. The percentage of CsA determinations resulting in plasma levels below 50 ng/ml (the limit of detection) increased with the time of therapy and constituted 22% of all CsA-PL after 6 months of therapy. No rejections were seen later than 5 months after transplantation despite the low CsA-PL in many long-term treated patients. Treatment with high doses of methylprednisolone increased CsA-PL by 223%. Trimethoprimsulphamethoxazole in CsA-treated patients caused increases in serum creatinine levels. Monitoring of trough CsA plasma levels is recommended as a complement to clinical judgment. To avoid most nephrotoxicity and hepatotoxicity we have decided to keep the CsA-PL below 500 ng/ml during the first month, below 250 ng/ml the second month after transplantation, and below 200 ng/ml the third month after transplantation--and in long-term treated patients we now keep the CsA-PL between less than 50 and 150 ng/ml.

Adolescent↗
PubMed1985

Excision biopsy of the spleen by ultrasonic guidance.

Excision biopsy of the spleen was performed in 32 patients, using a recently invented instrument, which consists of a spring-trigger system for firing the two parts of a Tru-Cut needle. The biopsies were carried out under the guidance of an ultrasonic scanner. This technique yields sufficient material of high quality for a proper evaluation both of individual cells and the internal structure of the spleen. Eight patients had parenchymal abnormalities found by ultrasonic scanning: five had multiple abnormalities whereas three had a single abnormal area. Seven of these eight patients had a pathological spleen biopsy, consisting of Hodgkin's disease (four patients), "high-grade" malignant non-Hodgkin's lymphoma (two patients) or tuberculosis (one patient). In the other 24 patients with a normal ultrasonic picture of the splenic parenchyma five biopsies were pathological (3 cases of hairy-cell leukaemia, 1 of Gaucher's disease and 1 of Hodgkin's disease). Side-effects were: slight to moderate pain (16/32 patients) and bleeding requiring transfusion (4/32 patients). In one of these patients splenectomy was performed because of the bleeding. Two of the patients with bleeding complications suffered from hairy-cell leukaemia. It is concluded from this study that excision biopsy of the spleen is a diagnostic method which in some patients can replace splenectomy. The method seems to be valuable especially in patients with parenchymal abnormalities shown by ultrasonic scanning.

Adolescent↗
PubMed1984

Organic acid transport to the blood from the corpus striatum, the thalamus and the cerebellum of the rat.

Conscious rats were given intracerebral injections by preplaced microsyringes. The injectates were 0.3-0.5 microliters of 125I- and 131I-o-iodohippurate. One hour after injection the isotopes present in the unopened cranial cavity were measured by gamma spectrometry. Some animals received 200 mg/kg probenecid intraperitoneally and this reduced the rate of absorption from injectates into the corpus striatum to 65.7 +/- 12.6% of control; from injectates into the cerebellum to 57.1 +/- 9.8% of control. Dye injections showed that injections into the cerebellum did not remain in the parenchyma, in contrast to injections into the corpus striatum or thalamus. Probenecid was also given as 2.9% solution, pH 7, mixed with the iodohippurate in the microsyringe. It had no effect on injections into the cerebellum, reduced the rate of absorption from the corpus striatum to 80.9 +/- 3.2% of controls and that from the thalamus to 88.3 +/- 2.2%. The results indicate parenchymal probenecid-sensitive transport of iodohippurate from the corpus striatum and thalamus but failed to settle the matter for the cerebellum.

Absorption↗
PubMed1984

Investigation of retroperitoneal lymph nodes in Hodgkin's disease.

For staging of Hodgkin's disease 45 patients underwent lymphography and abdominal computed tomography (CT); in 31 of them ultrasound examination was also performed. In cases of retroperitoneal lymph node enlargement lymphography and CT are diagnostically equivalent, whereas the poorer resolution of ultrasound reduces the reliability of this method when the lymph nodes are only slightly enlarged. Theoretically with lymphography also small lymphomatous lesions in normal-sized lymph nodes should be possible to demonstrate, but there is a clear tendency to overdiagnosis. CT is therefore recommended as the initial method and this examination is considered sufficient both in clearly negative and clearly positive cases. In doubtful cases and in those where CT has revealed solitary slightly enlarged lymph nodes, the examination should be supplemented with ultrasonic scanning and lymphography.

Hodgkin Disease↗
PubMed1983

Size of normal retroperitoneal lymph nodes.

The CT diagnosis of diseases in the retroperitoneal lymph nodes is based mainly on an evaluation of the size of the nodes in the transverse plane. Opinions on the normal size of the nodes vary, however. With the aim of obtaining a normal material, the diameters of the lymph nodes were measured on lymphograms that had been considered to be normal, from 95 patients. The upper limit for the diameter is not the same for all lymph nodes, but varies with the position of the node in the para-aortic chains, ranging from 7 to 15 mm, with increasing diameters in the caudal direction.

Adolescent↗
PubMed1982

Effect of epidermal growth factor on membrane motility and cell locomotion in cultures of human clonal glioma cells.

Two clones, designated Cl 2 and Cl 3, were established from the human malignant glioma line U-343 MGa. The astrocytic origin of the cells was proven by the presence in virtually 100% of the cells of the astrocyte marker glial fibrillary acidic protein. The addition of 10 ng epidermal growth factor (EGF) per milliliter to Cl 2 and Cl 3 cells resulted in the rapid appearance of large cell surface ruffles, visualized by scanning electron microscopy. A time course study by phase contrast microscopy showed that the maximal ruffling activity occurred 5 minutes after addition of EGF. Under basic culture conditions (Eagle's MEM, 10% fetal calf serum), Cl 2 and Cl 3 cells were essentially immobile and formed tightly packed, well demarcated colonies. In the presence of 10 ng EGF per milliliter, no defined colonies were formed and the cells seemed to move around freely. The stimulatory effect of EGF on cell migration was confirmed by growing the cells on a deposit of colloidal gold; in the absence of EGF, the cells remained immobile whereas cells grown at 10 ng EGF per ml formed long phagokinetic tracks. The effect of EGF on membrane motility and cell locomotion occurred in the absence of any effect of EGF on growth rate; both clones multiplied at the same rate in the absence as in the presence of EGF. Binding experiments using 125I-labeled EGF demonstrated a single class of high affinity receptors. The number of 180,000 receptors per cell was estimated in both clones. The finding that human glioma cells in culture require EGF for their migration raises the interesting possibility that tumor cells in vivo may respond in a similar fashion, and in that case require a growth factor for migration and for the expression of their infiltrative growth potential. Furthermore, the present findings strengthen the notion that glial cells should be recognized as targets for EGF.

Cell Division↗
PubMed1982

Computed tomography, ultrasound and lymphography in the diagnosis of malignant lymphoma.

Lymphographic findings were compared with the results at histopathology in 42 laparotomized patients with malignant lymphoma. Of 12 patients with lymphographically suggested lesions in normal-sized lymph nodes, only one had pathologic changes at histologic examination. Computed tomography gave a better idea of the extent of the disease than lymphography. Moreover, CT had an equal diagnostic accuracy as lymphography for demonstrating enlarged para-aortic lymph nodes. CT should therefore be able to replace lymphography in examination of malignant lymphoma. Ultrasound had the same diagnostic accuracy as CT regarding the upper and middle abdomen but not in the lower abdomen. Ultrasound is of special value in thin patients and when guided needle biopsy is required.

Body Weight↗
PubMed1982

Imaging of a mobile object at computed tomography.

A number of physiologic movements in the body influence the image at CT scanning. The pulsations of the abdominal aorta result in a motion of the retroperitoneal lymph nodes in the transverse plane. In connection with lymphography, the motion of the lymph nodes was analysed in 10 patients. The maximum motion in the transverse plane was 2.5 mm. In phantom experiments an object with a diameter of 10 mm was scanned during pulsating movements. Based on these experiments it was concluded that the motion of the lymph nodes does not seem to be of any importance for the reproduction of the node size, whereas motion in the CT plane will probably impair the resolution and thus the imaging of the internal structure of the nodes.

Humans↗
PubMed1982

Pre- and postoperative abdominal examinations in testicular carcinoma.

The histopathologic findings at retroperitoneal lymph node excision in 29 patients with a non-seminomatous germ cell tumour were compared with the findings at preoperative computed tomography, ultrasound and lymphography. The possibilities of detecting retroperitoneal metastases are somewhat greater with computed tomography than with lymphography. In the present material ultrasound was less reliable than computed tomography for demonstrating small metastases. At postoperative follow-up, in more than half of the patients computed tomography could not discriminate benign postoperative abnormalities from recurrent tumours. Ultrasound seemed to be a more reliable method for postoperative evaluation of the retroperitoneal space.

Adolescent↗
PubMed1981

Additive clinical effect of indomethacin suppositories during salicylate therapy in rheumatoid patients.

Twelve rheumatic patients were given 2.0 and 4.5 g acetylsalicylic acid daily in two 3-week periods. On days 13 and 20 of each period the patients took a suppository containing either placebo or 50 mg of indomethacin. The study was performed double-blind. Indomethacin had a significant additive effect during ASA therapy with 2 g daily as estimated by articular index and subjective ratings of pain and morning stiffness. On the 4.5 g ASA dose there was a significant improvement only for articular index. The patients experienced less pain during maintenance therapy with 4.5 g of ASA compared with 2.0 g daily. Both ASA doses induced complete inhibition of prostaglandin PGF2 alpha release from platelets. Thus the suppression of PGF2 alpha release does not reflect the therapeutic response of these drugs. Side effects observed comprised tinnitus, dizziness and gastritis. In 2 of the patients the aminotransferase levels increased, indicating hepatotoxicity. The protein binding of salicylate decreased with increasing salicylate concentration. As the dose was increased from 2.0 to 4.5 g/day the unbound concentration increased 5 to 24 times. This reflects the combined effect of capacity-limited metabolism and capacity-limited protein binding of salicylate.

Adult↗
PubMed1978

Influence of food on the absorption of acetylsalicylic acid from enteric-coated dosage forms.

The absorption of acetylsalicylic acid (ASA) from two different enteric-coated dosage forms, tablets (Premaspin) and granules (Reumyl), was studied in healthy volunteers under fasting and non-fasting conditions by following the plasma concentration and urine recovery of salicylates after single doses of ASA 1 g. Conventional tablets (Aspirin) were used as the reference. Under fasting conditions the absorption of ASA from the two different enteric-coated preparations was complete. Taken with food the enteric-coated tablets gave much lower plasma concentrations than under fasting conditions, and absorption was not complete in all subjects. In contrast, absorption from the enteric-coated granules was not influenced by the intake of food. It was concluded that enteric-coated granules of ASA permit more reproducible absorption than enteric-coated tablets.

Adult↗