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Biomedical subjects

K Thomsen

Publications and source records attributed to K Thomsen.

At least 55 records · Page 3Linked to original sources
PubMed1997

1997 Volvo Award winner in clinical studies. The effect of pedicle screw instrumentation on functional outcome and fusion rates in posterolateral lumbar spinal fusion: a prospective, randomized clinical study.

STUDY DESIGN: A prospective randomized clinical study. OBJECTIVES: To evaluate supplementary pedicle screw fixation (Cotrel-Dubousset) in posterolateral lumbar spinal fusion. SUMMARY OF BACKGROUND DATA: The rationale behind lumbar fusion is to eliminate pathologic motion to relieve pain. To improve fusion rates and to allow reduction, a rigid transpedicular screw fixation may be beneficial, but the positive effect of this may be counter-balanced by an increase in complications. METHODS: The inclusion criteria were severe, chronic low back pain from spondylolisthesis Grades 1 and 2 or from primary or secondary degenerative segmental instability. One hundred thirty patients were randomly allocated to receive no instrumentation (n = 66) or Cotrel-Dubousset instrumentation (n = 64) in posterolateral lumbar fusion. Variables were registered at the time of surgery and at 1 and 2 years after surgery. RESULTS: Follow-up was achieved in 97.7% of the patients. Fusion rates deduced from plain radiographs were not significantly different between instrumented and noninstrumented groups. The functional outcome assessed by the Dallas Pain Questionnaire improved significantly in both groups, and there were no significant differences in results between the two groups, except for significantly better (P < 0.06) functional outcome in relation to daily activities in the instrumented group when neural decompression had been performed. The global patients' satisfaction was 82% in the instrumented group versus 74% in the noninstrumented group (not significant). Fixation of instrumentation increased operation time, blood loss, and early reoperation rate significantly. Patients experienced only a few minor postoperative complications; none were major. Two infections appeared in the Cotrel-Dubousset group. Significant symptoms from misplacement of pedicle screws were seen in 4.8% of the instrumented patients. CONCLUSIONS: Lumbar posterolateral fusion with pedicle screw fixation increases the operation time, blood loss, and reoperation rate, and leads to a significant risk of nerve injury. The functional outcome improves significantly with high patient satisfaction, with or without instrumentation. No significant differences were observed between the two groups in functional outcome and fusion rate. The only gain in functional outcome from instrumentation was found in the daily activity category in patients with supplementary neural decompression. The results of this study do not justify the general use of pedicle screw fixation alone as an adjunct to posterolateral lumbar fusion.

Adult↗
PubMed1997

[Medication errors in a pediatric department].

In a prospective study, iatrogenic medication errors were registered among paediatric admissions. The two most common causes of incidents were neglecting to give a medication on schedule and administration of an incorrect dose-but extra dose errors, errors of omission, wrong rate errors and administration of unauthorized drugs also occurred. After implementation of a satellite pharmacy, medication error rates were compared, and a reduction of the more serious and potentially harmful incidents was shown.

Denmark↗
PubMed1997

Pincer nails and alopecia as markers of gastrointestinal malignancy.

Nail abnormalities may be markers of non-dermatologic disease. We present a case in which pronounced pincer nails and universal alopecia developed in association with a metastasising adenocarcinoma of the sigmoid colon. It is suggested that this association represents a new ectodermal paraneoplastic syndrome.

Adenocarcinoma↗
PubMed1997

Effect of adrenalectomy on distal nephron lithium reabsorption induced by potassium depletion.

In potassium-depleted rats lithium is reabsorbed by an amiloride-sensitive transport mechanism in the distal nephron segments, and the urinary fractional excretion of lithium (FE[Li]) is reduced by almost 50% compared to that of potassium-replete rats. We have used renal clearance techniques to study the effects of adrenalectomy (Adx) or sham operation on amiloride-sensitive lithium reabsorption in conscious potassium-deprived (K5) and control (K200) rats. In the sham-operated rats, administration of a low potassium diet led to a significant reduction in FE(Li) from 27.0 to 16.6% (p < 0.01), whereas in the Adx rats the reduction in FE(Li) was smaller (from 27.0 to 22.6) and not statistically significant. Urinary sodium excretion was similar (1,100 nmol/min/100 g body weight) in all groups. During subsequent amiloride infusion in order to block the distal nephron reabsorption of lithium, urinary sodium excretion increased nearly twofold in the sham-operated groups whereas no change was evident in the Adx rats. Similarly, amiloride led to an increase in FE(Li) in the sham-K5 group but failed to increase FE(Li) in the Adx-K5 group. The results suggest that amiloride-sensitive lithium transport seen during potassium depletion is influenced by the presence of the adrenal glands, most likely due to their production of aldosterone.

Adrenal Glands↗
PubMed1997

Proximal tubular function in essential hypertensives on beta-blocker therapy with atenolol.

Renal plasma flow (RPF) and glomerular filtration rate (GFR) were measured during waterloading and constant infusion of [131I]hippuran and [125I]iothalamate in 24 mild to moderate essential hypertensive patients before and after 3.5 months treatment with atenolol. Clearances of sodium and potassium were measured 2-3 hours post-dosing and renal vascular resistance (RVR) and filtration fraction (FF) were calculated. Measurement of clearance of lithium (CLi) and uric acid (Curic acid) was employed to investigate specifically proximal tubular function. Beta-blockade with atenolol produced a borderline significant decrement in RPF but no change in GFR, RVR and FF. There was a significant reduction in CLi, fractional proximal escape of sodium and water, Curic acid and an increase in absolute proximal reabsorption of sodium, indicating an inhibition of proximal tubular function. The distal tubular parameters exhibited changes tending to normalize excretion of sodium, but not water. Changes in RVR were inversely related to changes in CLi and Curic acid, suggesting unopposed alfa-adrenergic stimulation to be implicated in the renal counterregulation at a proximal tubular site following long-term administration of atenolol in essential hypertension.

Adrenergic beta-Antagonists↗
PubMed1997

Subcutaneous lesions and bacteraemia due to Stenotrophomonas maltophilia in three leukaemic patients with neutropenia.

Subcutaneous lesions were seen in three of 13 neutropenia patients who had Stenotrophomonas (Xanthomonas) maltophilia bacteraemia. The characteristic clinical presentation resembled leukaemic infiltrates, and were different from deep ulcers or subcutaneous nodules caused by Pseudomonas aeruginosa. The three patients had acute leukaemia and were treated with intensive combination chemotherapy. All had previously been treated with broad-spectrum antibiotics, and each patient recovered after proper combination antibiotic treatment given according to sensitivity testing.

Adult↗
PubMed1997

Influence of renal nerves and sodium balance on the acute antidiuretic effect of bendroflumethiazide in rats with diabetes insipidus.

To examine the role of the renal nerves and sodium depletion for the acute antidiuretic response to bendroflumethiazide (BFTZ; 25 microg/hr) in rats with diabetes insipidus (DI), renal clearance experiments were performed in the following groups of conscious, chronically instrumented male Brattleboro rats with vasopressin-deficient DI: Control (n = 7), BFTZ (n = 9), BFTZ + sodium replacement (n = 7) and BFTZ + chronic bilateral renal denervation (n = 6). Urine flow rate and urinary sodium concentration were measured drop-by-drop with a sodium-sensitive electrode and by collection of urine in vials placed on an electronic balance. This allowed computer driven, servo-controlled, independent i.v. replacement of sodium and fluid losses, respectively. Mean arterial pressure, glomerular filtration rate (GFR) and proximal tubular water and sodium handling, assessed by lithium clearance (C(Li)), were stable in the control group. BFTZ produced a marked antidiuretic response (deltaV = -79%; deltaUrine osmolality = +218%) associated with decreases in GFR (-28%), C(Li) (-62%), free water clearance (-100%) and plasma Na (-5 mM). Fractional water reabsorption was increased by 19% in the proximal tubules and by 7% in segments beyond. Sodium replacement did not modify the fall in GFR or the antidiuresis, but partly prevented the increase in fractional proximal water reabsorption. Bilateral renal denervation did not affect the response to BFTZ. We conclude that the acute antidiuretic effect of BFTZ is independent of sodium balance and renal nerve activity and is elicited by a reduction in GFR accompanied by an increase in fractional water reabsorption in the proximal tubules and in the distal nephron.

Animals↗
PubMed1996

Pharmacokinetics and interspecies scaling of recombinant human factor VIII.

Recombinant human (rh) factor VIII is a glycoprotein consisting of multiple polypeptides with relative mobilities (M(r)) ranging from 80,000 to 210,000. It is produced in mammalian cells. Single-dose intravenous pharmacokinetic studies were conducted with rh factor VIII (Kogenate rh Antihemophilic Factor, Miles, Inc.) in male mice (21.0-25.8 g) and rats (252.0-254.2 g). Each species received 400 IU/kg, and blood was collected up to 12 hr (mice) or 32.5 hr (rats) post-dose. Immunoreactive factor VIII concentrations in plasma were quantified by a sensitive and specific ELISA. In both species, the disposition profiles were described by the sum of two exponentials. The pharmacokinetics of rh factor VIII in mouse were as follows: clearance, 27.7 ml/hr/kg; initial volume of distribution, 72 ml/kg; steady-state volume of distribution, 148 ml/kg; and terminal half-life, 4.1 hr. In rat, the mean estimates were as follows: clearance, 16.0 ml/hr/kg; initial volume of distribution, 41 ml/kg; steady-state volume of distribution, 125 ml/kg; and terminal half-life, 5.5 hr. These pharmacokinetic parameters for rh factor VIII in animals and human rh factor VIII pharmacokinetic parameters from the literature were evaluated to determine if the parameters can be represented by the allometric relationship, Y = aWb, where Y is the pharmacokinetic parameter, and W is body weight. The following allometric relations were obtained for rh factor VIII: clearance (ml/hr) = 10.4W0.69, half-life (hr) = 7.5 W0.18, initial volume of distribution (ml) = 43.6 W1.04, and steady-state volume of distribution (ml) = 99.1 W0.84. The allometric exponents for each parameter conformed to theory and were within the range of values commonly observed for xenobiotics and therapeutic proteins. These studies suggest that the pharmacokinetics of rh factor VIII in laboratory animals are predictive of the disposition in humans despite the complex nature of its biological interactions and the chemical diversity of the purified material.

Animals↗
PubMed1996

Multiple autoimmune manifestations in monoclonal gammopathy of undetermined significance and chronic lymphocytic leukemia.

In 18 cases of monoclonal gammopathy of undetermined significance, MGUS (monoclonal gammopathy of undetermined significance), admitted for diagnosed or suspected peripheral neuropathy, 11 patients showed other co-existing autoimmune manifestations. Two had POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, M-component, and skin symptoms), the others mainly endocrinopathy and polyclonal pseudolymphoma. There were 13 cases of sensorimotor neuropathy, two cases of neuritis, while neuropathy could not be confirmed in three cases. Compared with a retrospective review of autoimmunity in a randomly selected CLL (chronic lymphocytic leukemia) cohort of 115 patients, 13 out of 42 patients with clinical and/or laboratory features of autoimmunity showed co-expression of autoimmune signs, the dominating traits being Coombs positive AIHA (auto-immune hemolytic anemia), platelet autoantibodies, endocrinopathy mainly associated with the thyroid gland, serological and/or rheumatological symptoms, but only one case of sensorimotor neuropathy. Viewed from a current model of acquired autoimmunity it is perhaps not surprising that such autoimmunity is seen predominantly in patients with monoclonal gammopathy. Thus, a high concentration of cross-reacting polyreactive autoantibodies related to the M-component might be present in these patients. Furthermore, quantitative defects of the immunoglobulins including the hypogammaglobulinemia associated with M-components can presumably give rise to a defect of the anti-idiotypic network's regulation of natural autoantibodies and autoimmune manifestations in vivo. Such autoimmune manifestations, which are easily overlooked in CLL may call for additional treatment with immunosuppression and/or intravenous, polyclonal IgG.

Adult↗
PubMed1995

[Congenital kyphoscoliosis complicated by paraplegia].

Congenital scoliosis accounts for 10% of all scolioses which require treatment. Correct treatment demands an exact and early detection of the deformity. Early intervention may only require a minor operation. Two cases are presented with paraplegia as the first presenting symptom of congenital kyphoscoliosis. In both cases anterior decompression and spondylodesis was followed by early neurological recovery. After a second operation with posterior spondylodesis and instrumentation ad modum Cotrel-Dubousset the patients were mobilised. Patients with congenital spinal deformity ought to be investigated and treated in a highly specialized department of spinal surgery.

Adolescent↗
PubMed1995

Clozapine serum levels and side effects during steady state treatment of schizophrenic patients: a cross-sectional study.

Serum clozapine (S-Cloza) and serum desmethyl-clozapine concentrations (S-Descloza) were measured in 30 chronic schizophrenic in- and out-patients on a variable dose regimen. All patients were in steady state with respect to clozapine therapy and in a stable condition with respect to psychotic illness. The 24-h clozapine dose (median with interquartile range in parenthesis) was 350 (228-425) mg/24 h (range 100-700). There was a weak positive correlation between doses and the BPRS total score (r = 0.44, P < 0.05). The median S-Cloza was 1076 (706-1882) nmol/l (range 196-5581 corresponding to 64-1824 ng/ml). The S-Cloza was linearly correlated to dose but with a high interindividual variation at equal doses, e.g. a factor of 8 at 400 mg/24 h, but a low intraindividual variability of 20%. The S-Descloza averaged 77% of the S-Cloza and was highly correlated to S-Cloza (r = 0.90; P < 0.001). The S-Descloza/dose ratio increased with age and duration of treatment. The side effects registered were EEG abnormalities (83%), tachycardia (23%), increased liver enzyme activity (60%), orthostatic hypotension (17%), and moderate leucocytosis (17%). Only EEG changes were correlated to S-Cloza (r = 0.43; P < 0.05). The score values of the UKU Side Effect Scale were weakly (r = 0.36) correlated to S-Cloza. No side effects were correlated to S-Descloza, doses, or treatment duration. The frequency of side effects was higher than in studies using lower mean doses indicating a correlation between doses or S-Cloza and the frequency of side effects. It is concluded that clozapine fulfils the criteria for therapeutic drug monitoring. TDM may contribute to finding the lowest effective dose with the fewest possible side effects.

Adolescent↗
PubMed1995

Analyses of T-cell receptor beta-chain genes by Southern blotting in known and suspected cutaneous T-cell lymphoma. A study of 67 samples from 32 patients.

In this study we have investigated the configuration of the T-cell receptor (TCR) beta-chain genes in benign cutaneous conditions (n = 5) and known (n = 22) or suspected (n = 5) cutaneous T-cell lymphoma (CTCL). Sequential biopsies from skin, lymph node, blood and/or bone marrow were available in 12 cases of the 22 confirmed CTCL, and a total of 67 samples were analysed. In the benign conditions, clonal rearrangements of the TCR beta-chain genes were seen in neither skin nor blood samples. In contrast, in CTCL clonal rearrangements were detected in all skin samples from plaque or tumour lesions of mycosis fungoides. Clonal TCR rearrangements were also present in skin and blood samples from two patients with Sèzary's syndrome, and in skin and blood samples from three of five patients with clinically suspected CTCL. In 10 patients with large cell lymphomas, clonal rearrangements were detected in skin samples in half of the cases. In the remaining patients, clonal TCR rearrangements could not be detected in the skin, but only in the blood and/or bone marrow specimens. Results from the analyses of sequential biopsies showed identical patterns of rearrangement in 11 patients. In the remaining patient, the pattern of rearrangement differed between skin and lymph node. These data confirm and extend previous reports and indicate that analysis of TCR beta-chain genes by Southern blotting forms a useful supplement to other methods for the diagnosis of known and suspected CTCL. They also emphasize the importance of studying not only skin, but also extracutaneous sites.

Adolescent↗
PubMed1995

Gene rearrangement in positive patch tests.

Lymphoproliferative disorders are usually characterized by lymphoid infiltrates that demonstrate clonality in contrast to inflammatory or reactive infiltrates of the skin that are polyclonal without detectable monoclonal populations of T-cells. Probably the southern blot analysis of TCR gene rearrangement can help to delineate the reactive from the malignant processes. In this study, we applied the technique on benign reactive processes in the skin. We examined biopsies from positive patch tests from patients with a delayed hypersensitivity reaction. We found the same gene rearrangement configuration in 11 of 17 patients with positive patch tests. The extra band revealed in these cases was situated in the EcoR1 digested DNA lane at the 8.0 Kb, between the 2 germline bands at the 11 Kb and the 4 Kb respectively. This observation was not correlated to the degree of the inflammatory response or to the specific hapten induced reaction. This pattern was not found in any of 107 patients with malignant diagnoses, but also in six of 43 patients with benign diseases. The clinical implication may suggest the presence or development of clonality in benign inflammatory disorders.

Biopsy↗
PubMed1995

Solar pruritus.

A case of solar pruritus is reported. Severe pruritus of the back, shoulders and upper lateral aspects of the arms, without any eruption, developed in a 28-year-old outdoor worker during 4 to 6 weeks of intensive solar exposure. The pruritus was intense and described as a burning sensation deep in the skin. Only a few excoriations and slight xerosis were found. Solar pruritus or brachioradial pruritus is a condition primarily seen in Caucasian people living in the tropics or subtropics. Previously the disease has only been reported once outside these areas.

Adult↗