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K Thomsen

Publications and source records attributed to K Thomsen.

At least 37 records · Page 2Linked to original sources
PubMed2000

Mechanisms of distal-nephron Li(+) reabsorption during dietary K(+) restriction in rats.

The mechanism by which dietary K(+) restriction induces distal-nephron Li(+) reabsorption was investigated by administration of bendroflumethiazide (BFTZ) or vehicle in conscious Wistar rats. Changes in fractional excretion of Li(+) following administration of amiloride (DeltaFE(Li)) were used as an index of distal tubular Li(+) reabsorption. The results revealed an absence of distal tubular Li(+) reabsorption in K(+)-replete rats (DeltaFE(Li) = 3. 6+/-2.4%), in contrast to K(+) restriction in which DeltaFE(Li) was 24.0+/-2.7%. The distal tubular Li(+) reabsorption in K(+)-depleted rats was significantly reduced by preadministration of BFTZ (DeltaFE(Li) = 9.2+/-0.9%). The fractions of Li(+) and Na(+) reabsorbed in the amiloride-sensitive segment were different in K(+)-replete rats (9+/-6 vs. 60+/-6%), but similar in K(+)-depleted rats (61+/-5 vs. 73+/-4%). BFTZ administration to K(+)-depleted rats resulted in a proportional decrease in these fractions, suggesting competition between Na(+) and Li(+) for reabsorption in the distal-nephron segment during K(+) depletion. These results are compatible with the hypothesis that during K(+) depletion the reabsorption of Li(+ )in the distal-nephron segment is competitively inhibited by Na(+).

Amiloride↗
PubMed1999

[Results after surgical treatment of unstable thoracolumbar fractures].

Seventy-eight patients with unstable, one-level fracture of the thoracolumbar spine and no neurological impairment were treated with short segment fixation, transpedicular autologous bone transplantation and posterolateral fusion. Kyphotic deformity and anterior column height improved significantly. Complications consisted of one case of late deep infection, three cases of seroma, four cases with 5 mm schantz screw breakage and two cases with screw loosening. Mild to moderate pain was present in 79% of the patients at follow-up, median 32 (13-72) months. Sixty-seven percent of the patients had returned to previous activity levels of employment. Short posterior internal fixation, transpedicular transplantation and posterolateral fusion allowed neurologically intact patients to be mobilized early, to spend median 12 days in hospital, and carried no risk of deterioration in neurological function.

Adolescent↗
PubMed1999

[The effect of pedicle screw instrumentation on posterolateral spinal fusion. A prospective, randomized study with a two-year follow-up].

The aim was to evaluate the effect of supplementary pedicle screw fixation (Cotrel-Dubousset [CD]) in posterolateral lumbar spinal fusion. The study comprises 130 patients undergoing lumbar or lumbosacral fusion for spondyloisthesis grades I-II or degenerative segmental instability conditions. The patients were randomly allocated for no instrumentation (n = 66) or CD instrumentation (n = 64) in posterolateral lumbar fusion. A 97.7% follow-up was achieved. There were no significant differences between the two groups concerning fusion rates assessed by X-ray or functional outcomes assessed by Dallas Pain Questionnaire. The global patient satisfaction was 82% in the instrumented group versus 74% in the noninstrumented group. Instrumentation increased both operation time, blood loss, and early re-operation rates significantly. A high patient satisfaction was found in both groups. However, the results from this study do not justify the general use of pedicle screw fixation alone as an adjunct to posterolateral lumbar fusion.

Adult↗
PubMed1999

Can autologous bone culture predict spinal fusion capacity?

The capacity of the individual patient to initiate osteoblast proliferation as a predictor for successful lumbar spinal fusion has not yet been reported. The objectives of this study were, first, to analyze the relationship between in vitro osteoblast proliferation and clinical bony fusion in the individual patient in order to predict the fusion outcome and, second, to measure the effect of preoperative tobacco smoking on osteoblast proliferation. Sixty-one patients (mean age 46 years) underwent posterolateral lumbar fusion in the period 1994-1995. Thirty-eight patients received CD pedicle screw implants and 23 received posterolateral fusions alone. During surgery, autogenous iliac bone was harvested and 1 g of trabecular bone without blood or bone marrow was then isolated for cell culturing. The cultures were classified as excellent (confluence within 4 weeks), good (confluence between 4 and 6 weeks) and poor (no or poor growth). Spine fusion was evaluated by two independent observers from plain anterior-posterior, lateral, and flexion/extension radiographs taken 1 year postoperatively, and the functional outcome was measured by the Dallas Pain Questionnaire (DPQ). Twenty-three patients had excellent, 19 good, and 19 poor in vitro osteoblast proliferation. Bony fusion was obtained in 77% of patients: 83% in the CD instrumentation group and 70% in the non-instrumentation group (NS). There was no significant correlation between osteoblast proliferation and spinal fusion or functional outcomes when analyzing the CD instrumentation and non-instrumentation groups together or separately. Elderly patients had a significantly poorer osteoblast proliferation than younger patients (P < 0.008). Preoperative tobacco consumption had no discernible effect on osteoblast proliferation, and no correlation between smoking and fusion was found. Further refinement of autologous osteoblast culturing may provide a biological tool for selection of patients who require biological enhancement of their bone fusion capacity. The poorer osteoblast proliferation related to advanced age supports the important negative biological influence of age on bony fusion. However, with more sensitive testing and better discrimination, other results are possible - or can in any event not be excluded.

Adult↗
PubMed1999

Autoimmunity and extranodal lymphocytic infiltrates in lymphoproliferative disorders.

OBJECTIVE: To examine the relationship between autoimmunity and extranodal lymphocytic infiltrates in different lymphoproliferative disorders with immunoglobulin alterations. SUBJECTS AND DESIGN: A clinical review combined with a retrospective cohort study of 380 patients, 28 with monoclonal gammopathy of undetermined significance, three with common variable immunodeficiency, 147 with chronic lymphocytic leukaemia, 57 with Waldenström's macroglobulinaemia and 145 with non-Hodgkin's malignant lymphoma. SETTING: A university hospital and The State Serum Institute in Copenhagen. INTERVENTION: Clinical examination of each patient with special attention to chronic inflammatory and autoimmune manifestations. Biopsies were taken from non-infectious infiltrates, some of which were additionally tested with PCR analysis for gene rearrangements. Serological screening with a test battery for various autoantibodies was used in combination with techniques for the detection of M-components and monoclonal B-cell proliferation. MAIN OUTCOME MEASURES: Clinical and/or serological autoimmune manifestations, M-component and other immunoglobulin alterations, and inflammatory tissue changes were studied in patients with chronic inflammatory, polyclonal or oligoclonal pseudolymphomas and in monoclonal, malignant extranodal lymphomas. RESULTS: In 380 consecutive patients, 49 (12.9%) had extranodal manifestations, of whom 47 also had autoimmune manifestations. Nearly half of the 47 patients had more than one autoimmune manifestation. There was a strong correlation between clinical signs and corresponding autoantibodies such as anti-SSA and -SSB antibodies in Sjögren's syndrome (10 cases), antithyroid peroxidase antibodies in thyroiditis and Graves' disease (10 cases), and parietal cell antibodies in gastric ulcers with maltoma (12 cases). Clinical and serological signs of autoimmunity correlated strongly with female sex (34, 72% women; and 13, 28% men) and with immunoglobulin alterations. CONCLUSIONS: To our knowledge this is the first systematic review of B-lymphoproliferative and autoimmune disorders indicating that pseudolymphoma and malignant lymphomas, including maltomas, may develop in the context of a permanent autoantigenic drive.

Aged↗
PubMed1999

Avoidance of lithium intoxication: advice based on knowledge about the renal lithium clearance under various circumstances.

To avoid lithium intoxications, clinicians should counteract conditions under which lithium clearance changes. If that is not possible, the lithium dosage should be adjusted to the lithium clearance. Lithium clearance is usually 20-30 per cent of the glomerular filtration rate and varies with it, for example during pregnancy and kidney disease. Lithium clearance may also change independently of the glomerular filtration rate. It decreases for example during dehydration (water deficiency) and low sodium intake, pathological conditions with edema formation, treatment with diuretics, anti-hypertensive drugs, or non-steroid anti-inflammatory drugs. It increases during treatment with some vasodilating drugs. Precautionary measures against lithium intoxication are suggested for each of these situations.

Antimanic Agents↗
PubMed1999

Maternal plasma phospholipid polyunsaturated fatty acids in pregnancy with and without gestational diabetes mellitus: relations with maternal factors.

BACKGROUND: The fatty acids arachidonic acid (AA; 20:4n-6) and docosahexaenoic acid (DHA; 22:6n-3) are essential for fetal growth and development, but their metabolism may be altered in insulin resistance. OBJECTIVES: The objectives were to determine maternal plasma phospholipid polyunsaturated fatty acid concentrations in pregnant women receiving dietary therapy for gestational diabetes mellitus (GDM) and to identify maternal factors associated with plasma phospholipid AA and DHA concentrations in the third trimester. DESIGN: Fasting plasma phospholipid fatty acids were determined in women with GDM (n = 15) receiving dietary therapy only and in healthy, pregnant women without GDM (control group, n = 15) at 27-30, 33-35, and 36-39 wk gestation. RESULTS: Maternal plasma phospholipid (as % by wt of total fatty acids and mg/L) linoleic acid (18:2n-6), AA, and 22:5n-6 concentrations did not differ significantly between women with GDM and control subjects. The other n-6 long-chain polyunsaturated fatty acids (% by wt) were lower in GDM subjects than in control subjects. Plasma phospholipid (expressed as % by wt and mg/L) linolenic acid (18:3n-3) and summed precursors of DHA were lower and DHA (% by wt and mg/L), adjusted for dietary DHA intake, was 13% higher in GDM subjects than in control subjects. Maternal blood hemoglobin A1C was inversely related to plasma phospholipid AA (% by wt) (r = -0.56, P = 0.03) in control subjects and positively associated with plasma phospholipid AA (% by wt) in women with GDM (r = 0.76, P = 0.001). Pregravid body mass index was negatively associated with plasma phospholipid DHA (% by wt) in control subjects (r = -0.55, P = 0.04) and in women with GDM with a body mass index (in kg/m2) <30 (r = -0.76, P = 0.007). CONCLUSIONS: This is the first report documenting alterations in maternal plasma phospholipid PUFAs in pregnant women receiving dietary therapy for GDM. In pregnant woman, both with and without GDM, maternal glycemic control and pregravid BMI appear to be significant predictors of plasma phospholipid AA and DHA, respectively, during the third trimester. Additionally, dietary DHA significantly affects phospholipid DHA concentrations.

Arachidonic Acid↗
PubMed1999

Intraocular pharmacokinetics and safety of a humanized monoclonal antibody in rabbits after intravitreal administration of a solution or a PLGA microsphere formulation.

Poly(lactic-co-glycolic) acid (PLGA) bioresorbable microspheres are used for controlled-release drug delivery and are particularly promising for ocular indications. The objective of the current study was to evaluate the pharmacokinetics and safety of a recombinant human monoclonal antibody (rhuMAb HER2) in rabbits after bolus intravitreal administration of a solution or a PLGA-microsphere formulation. On Day 0, forty-eight male New Zealand white rabbits (2.3-2.6 kg) were immobilized with intramuscular ketamine/xylazine, and the test materials were injected directly into the vitreous compartment. Group 1 animals received rhuMAb HER2 in 50:50 lactide: glycolide PLGA microspheres; Group 2 animals received rhuMAb HER2 in solution (n = 24/group). The dose for each eye was 25 microg (50 microl). After dosing, animals were sacrificed at 2 min, and on 1, 2, 4, 7, 14, 23, 29, 37, 44, 50, and 56 days (n = 2/timepoint/group). Safety assessment included direct ophthalmoscopy, clinical observations, body weight, and hematology and clinical chemistry panels. At necropsy, vitreous and plasma were collected for pharmacokinetics and analysis for antibodies to rhuMAb HER2, and the vitreal pellet (Group 1) was prepared for histologic evaluation. All animals completed the study per protocol-both treatments were well tolerated, and no suppurative or mixed inflammatory cell reaction was observed in the vitreal samples (Group 1) at any of the time points examined. Antibodies to rhuMAb HER2 were detected in plasma samples by Day 7 in both treatment groups, but infrequently in vitreous samples. There were no safety implications associated with this immune response. The in vitro characterization of the PLGA microspheres provided reasonable projections of the in vivo rhuMAb HER2 release kinetics (Group 1). The total amount of antibody that was released was similar in vitro (25.9%) and in vivo (32.4%). RhuMAb HER2 (Group 2) was cleared slowly from the vitreous compartment, with initial and terminal half-lives of 0.9 and 5.6 days, respectively. The volume of distribution approximated the vitreous volume in a rabbit eye.

Animals↗
PubMed1999

Chronic lithium treatment inhibits amiloride-sensitive sodium transport in the rat distal nephron.

Chronic treatment of rats with lithium leads to Na+ loss and a reduced antinatriuretic response to aldosterone, suggesting that lithium reduces conductive Na+ transport in the distal nephron. This was investigated in the present study by measuring the renal response to aldosterone infusion followed by amiloride in chronically instrumented conscious rats given lithium for 3 to 4 weeks to achieve plasma Li+ concentrations of approximately 0.5 mM. A servo-controlled infusion system was used to maintain sodium and water homeostasis, thereby preventing misinterpretation of the findings as a consequence of drug-induced changes in Na+ balance. In a control group of rats, Na+ excretion decreased in response to aldosterone (p <.01) and subsequent amiloride administration led to a marked increase in Na+ excretion (p <.001). In contrast, in the lithium-treated group, there was no significant response to either aldosterone or amiloride. It is concluded that long-term treatment with lithium, even when plasma Li+ concentrations are below 1 mM, reduces aldosterone-stimulated Na+ transport through the amiloride-sensitive Na+ channels in the principal cells of the distal nephron.

Aldosterone↗
PubMed1999

Functional outcome after partial reduction and 360 degree fusion in grade III-V spondylolisthesis in adolescent and adult patients.

Reduction of high-grade spondylolisthesis is a surgically demanding procedure, which has been reported to incur a relatively high risk of neurologic damage, pseudoarthrosis, and other complications. The aim of this study was to evaluate the radiographic and functional outcome in spondylolisthesis grade III-V, surgically treated with posterior decompression, L4- or L5-S1 CD instrumentation, partial reduction, and posterolateral fusion followed by anterior interbody fusion L5-S1 ad modum Kellogg-Speed. Thirteen patients, mean age 23.8 (range, 11-33) years were followed for mean 28.5 (range, 19-52) months. The anterior slip, lumbosacral angle, sagittal rotation angle and L4/SI angle were significantly improved from preoperatively to follow-up. No patients had neurologic, vascular, thromboembolic, or lung complications. Twelve patients reported a better or unchanged (3 patients) physical and emotional status. At follow-up, 10 patients were in full-time jobs or back to school. The method was safe and provided a stable rigid fixation with partial reduction of the deformity and a satisfactory functional outcome.

Adolescent↗
PubMed1998

Functional outcome after posterolateral spinal fusion using pedicle screws: comparison between primary and salvage procedure.

Lumbar spinal fusion is a commonly performed surgical procedure, yet both the indications for its performance and its results remain controversial. It is generally believed that apart from situations where obvious measurable instability exists, a repeat surgical procedure such as spinal fusion does not improve the functional outcome in more than an average of 50% of cases. The aim of this study was to analyse functional outcome after posterolateral lumbar or lumbosacral spinal fusion, comparing primary and salvage procedures. It was designed as a prospective case/referent study with a 2-year follow-up. A total of 39 patients underwent a short posterior fusion with Cotrel-Dubousset (CD) pedicle screw fixation after earlier surgery of the lumbar spine. Two patients were erroneously omitted from the study at the index, so 37 patients were included in the salvage group. In the same period, 69 patients underwent lumbar fusion with pedicle screw fixation (CD) as primary surgery (referent group). Functional outcome was assessed by means of the Dallas Pain Questionnaire preoperatively and 1 and 2 years postoperatively. Fusion rates were determined by ordinary X-ray evaluation by two independent observers. Patients who had undergone previous spinal surgery had a significant improvement in functional outcome in terms of daily activity, work and leisure-time activities and anxiety/depression. With regard to social functioning, a significantly inferior outcome was found after the salvage procedure. The return-to-work rates at 2 years after surgery were 50% in the salvage group and 53% in the referent group. There was a significant correlation between radiological evaluation of the fusion mass and the functional outcome. The fusion rate was 76% in the salvage group and 72% in the referent group. This study demonstrates that a posterolateral spinal fusion can be effectively used as a salvage procedure. The functional and radiological outcome of the patients with revision surgery did not differ from those of the group of patients who underwent primary surgery. There was, however a clear indication of inferior social functioning after revision surgery.

Adult↗
PubMed1998

Ofuji's papuloerythroderma: a study of 17 cases.

In this retrospective study the clinical, laboratory and histological features, treatment methods and disease course in 17 patients with papuloerythroderma (PE) are reviewed. The median age at diagnosis was 72 years and the female/male ratio was 1:4:7. The most common abnormal laboratory findings were eosinophilia and an elevated serum IgE level. Psoralen photochemotherapy (PUVA) and oral prednisolone 10-20 mg daily given in combination or alone were very efficient treatments, while UVB phototherapy in combination with topical steroids was also successful. However, potent topical corticosteroids alone or in combination with oral antihistamines were not effective. The patients were observed for a median of 19 months from diagnosis, three being followed for more than 5 years. Five of the patients relapsed, but only one had multiple relapses, two developed cutaneous T-cell lymphoma (CTCL) and two others had histological features suggestive of that disorder. Six of the patients died, cardiovascular disease being the most common cause. PE is a distinct clinical entity with a polymorphous aetiology which frequently includes an association with CTCL or visceral malignancy. PUVA, oral corticosteroids and UVB in combination with topical corticosteroids appear to be effective therapeutic modalities.

Aged↗
PubMed1998

Model explaining the relation between distal nephron Li+ reabsorption and urinary Na+ excretion in rats.

Li+ may be reabsorbed via an amiloride-sensitive mechanism in the collecting ducts of rats administered a low-Na+ diet. This was investigated by measuring the increase in fractional urinary excretion of Li+ (FELi) in response to amiloride in conscious rats at two different levels of plasma Li+ concentration and after administration of bendroflumethiazide (BFTZ), angiotensin III (ANG III), and aldosterone (Aldo). The results confirmed that amiloride increased (FELi) in rats on a low-Na+ diet (20 +/- 1 to 35 +/- 1%, means +/- SE), whereas no increase was observed in rats on a normal Na+ diet (37 +/- 1 to 38 +/- 1%). The lithiuretic effect of amiloride was 1) abolished by preadministration of BFTZ (32 +/- 1 to 33 +/- 2%) to Na(+)-deprived rats and 2) increased by ANG III (27 +/- 3 to 33 +/- 2%) and Aldo (25 +/- 2 to 37 +/- 2%) in Na(+)-replete rats. Amiloride-induced changes in FELi were independent of plasma Li+ concentration but inversely related to the fractional excretion of Na+ and the amiloride-sensitive excretion of K+. These results are compatible with the hypothesis that a low tubular Na+ concentration reduces end-tubular Na+ reabsorption and results in hyperpolarization of the apical membrane, thus favoring Li+ uptake into the cells.

Aldosterone↗
PubMed1998

Family pattern and family care in Greenland.

Information on household and family patterns from the 1993-94 Health Interview Survey in Greenland is described. The average size of households is 3.5, and almost three-fourths of the Greenlandic population live in families with children. The pattern of these families with children covers a variety of single-parent families (6% of the total Greenlandic population), nuclear families (42%), extended families (14%), and other types of families (11%).

Adult↗
PubMed1998

The role of hunting in a socioeconomic classification for Greenland.

The socioeconomic classification used in Western societies is not directly applicable to Greenland where other factors, such as success as a hunter, participation in community life, and raising children, also convey status and must be included in a status coding. In the 1993 Greenland Health Interview Survey the participants' hunting activities were estimated through a number of questions. Nineteen percent of male Greenlanders classified themselves as hunters when asked about their primary occupation, but in another question an additional 10% stated that they relied on hunting for a living. When asked about their job, hunters were confused as to whether hunting was considered a job by the researchers. This uncertainty may explain the difference between the two questions regarding classification of individuals as hunters. For future research it is necessary to develop a socioeconomic status classification which is culturally sensitive and suited to contemporary Greenlandic society.

Animals↗