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Biomedical subjects

H K Nielsen

Publications and source records attributed to H K Nielsen.

At least 19 recordsLinked to original sources
PubMed2001

Incomplete thromboxane inhibition with 100 mg of intravenous acetylsalicylic acid in patients with acute ST elevation myocardial infarction: a placebo-controlled pilot trial.

BACKGROUND: Acetylsalicylic acid (ASA) is now a standard treatment of acute myocardial infarction (AMI). ASA inhibits thromboxane A(2) (TXA(2)) production by blocking the constitutive cyclooxygenase (COX)-1 enzyme, but only to a small degree the inducible COX-2. COX-2 is induced by increased concentrations of cytokines, which is related to an enhanced inflammatory response. Previously, we have found a complete inhibition of TXA(2) synthesis in healthy volunteers after intravenous administration of 50 mg of ASA. We measured in a randomized, placebo-controlled pilot trial the effect of 100 mg of ASA injected intravenously on TXA(2) synthesis in AMI patients treated with streptokinase. METHODS AND RESULTS: Nineteen patients with AMI treated with streptokinase were randomized to 100 mg of ASA or placebo injected intravenously. Se-TXB(2) and bleeding time were measured before and after drug administration. One hundred and eighty minutes after intravenous ASA administration, treatment with oral ASA was initiated. We found a significant decrease in serum concentrations of TXB(2) after 30, 60 and 180 min following ASA injection compared to placebo, but in none of the patients was complete inhibition of TXA(2) production achieved. No significant change in bleeding time could be demonstrated. CONCLUSION: Intravenous ASA in a dosage of 100 mg did not completely prevent TXA(2) production in AMI patients treated with streptokinase. This may be due to synthesis of TXA(2) by the inducible COX-2 enzyme and/or to a transcellular metabolism in platelets of prostanoids generated by endothelial cells.

Aged↗
PubMed2000

[Anticoagulant treatment].

In 1998, the sale of vitamin K antagonists (VKA) in Denmark corresponded to the amount used for treatment of more than 20,000 patients for one year. This is more than three times more than ten years earlier. The reasons for the increasing use of VKA are new indications for permanent anticoagulant treatment, especially chronic atrial fibrillation and venous thromboembolism associated with permanent thromboembolic risk factors. The risk of bleeding is higher in the introductory phase of anticoagulant treatment than later on. It is now recommended to commence anticoagulant therapy without a loading dose. This seems to hasten a good estimate of the maintenance dose. The metabolism of VKA depends on a number of genetic and acquired factors. Knowledge of these factors is crucial for optimal regulation of the treatment, and it is important that patients at start of treatment are thoroughly informed about these factors in order to minimize the risk of complications.

Anticoagulants↗
PubMed2000

Fractures in patients with primary idiopathic hypothyroidism.

AIM: To study fracture risk and risk factors for fractures in patients with primary idiopathic hypothyroidism (ICD 10: E03.9). DESIGN: Historical follow-up. MATERIAL AND METHODS: A self-administered questionnaire was issued to 628 patients with primary idiopathic levothyroxine-substituted hypothyroidism. A total of 412 (65.6%) responded and of these, 408 could be analyzed. The 408 respondents were age- (+/- 5 years) and gender-matched with 408 normal controls randomly selected from the background population who responded to the same questionnaire. RESULTS: Overall fracture risk was increased in patients compared to controls (relative risk: RR = 1.6, 95% CI: 1.0-2.5). However, the increase was temporary and limited to the period within the first 2 years after the diagnosis of hypothyroidism (RR = 3.1, 95% CI: 1.4-7.0). Before the diagnosis and more than 2 years after the diagnosis, the fracture risk in patients did not deviate from that of the controls. The increase in fracture risk was only significant in the age group above 50 years (RR = 1.8, 95% CI: 1-3.2), and was limited to the forearms (RR = 3.0, 95% CI: 1.4-6.3 for the entire patient population). CONCLUSIONS: There was a temporary increase in fracture risk within the first 2 years after diagnosis of primary idiopathic hypothyroidism. The fracture risk was mainly increased in the age group above 50 years, and the increased risk was limited to the forearms.

Adult↗
PubMed1999

On the occurrence of anoxic microniches, denitrification, and sulfate reduction in aerated activated sludge.

A combination of different methods was applied to investigate the occurrence of anaerobic processes in aerated activated sludge. Microsensor measurements (O(2), NO(2)(-), NO(3)(-), and H(2)S) were performed on single sludge flocs to detect anoxic niches, nitrate reduction, or sulfate reduction on a microscale. Incubations of activated sludge with (15)NO(3)(-) and (35)SO(4)(2-) were used to determine denitrification and sulfate reduction rates on a batch scale. In four of six investigated sludges, no anoxic zones developed during aeration, and consequently denitrification rates were very low. However, in two sludges anoxia in flocs coincided with significant denitrification rates. Sulfate reduction could not be detected in any sludge in either the microsensor or the batch investigation, not even under short-term anoxic conditions. In contrast, the presence of sulfate-reducing bacteria was shown by fluorescence in situ hybridization with 16S rRNA-targeted oligonucleotide probes and by PCR-based detection of genes coding for the dissimilatory sulfite reductase. A possible explanation for the absence of anoxia even in most of the larger flocs might be that oxygen transport is not only diffusional but enhanced by advection, i.e., facilitated by flow through pores and channels. This possibility is suggested by the irregularity of some oxygen profiles and by confocal laser scanning microscopy of the three-dimensional floc structures, which showed that flocs from the two sludges in which anoxic zones were found were apparently denser than flocs from the other sludges.

Anaerobiosis↗
PubMed1998

Effects of short-term treatment with prednisolone and calcitriol on bone and mineral metabolism in normal men.

To study the effects of treatment with glucocorticoid and calcitriol on biochemical markers of calcium and bone metabolism, 48 normal male volunteers (aged 21-54 years) were randomized to treatment for 7 days with either (A) prednisolone, 10 mg twice daily, (B) prednisolone, 10 mg twice daily, and calcitriol, 1 microg twice daily, (C) calcitriol 1 mg twice daily, or (D) placebo. The study period was 28 days. Renal calcium excretion increased (mean maximal increase +44.7%, p < 0.01) as well as serum parathyroid hormone (PTH) (max. +18.5%, p < 0.01) during prednisolone treatment. Concomitant treatment with calcitriol or calcitriol alone equally enhanced renal calcium excretion (max. +185.2%, p < 0.001) and decreased serum PTH (max. -43.1%, p < 0.001). Prednisolone administration was followed by prompt declines in markers of bone formation [serum osteocalcin (max. -34.7%, p < 0.001) and serum procollagen type I C-terminal propeptide (PICP) (max. -25.9%, p < 0.05)], whereas serum bone alkaline phosphatase (bone AP) remained unchanged. Calcitriol in combination with prednisolone attenuated the decrease in PICP (max. -8.9%, not significant), but it had no effect on osteocalcin (max. -40.1%, p < 0.001), and decreased bone AP (max. -22.2%, p < 0.05). Calcitriol alone increased osteocalcin (max. +37.8%, p < 0.03) and PICP (max. +26.0%, p < 0.05). Among markers of bone degradation, prednisolone suppressed serum C-terminal telopeptide of type I collagen (ICTP) (max. -28.4%, p < 0.001), but not the fasting renal excretion of hydroxyproline (OHP) and collagen type I N-terminal telopeptide (NTx). Calcitriol partially antagonized the decrease in ICTP (max. -17.2%, p < 0.001). Calcitriol alone had no effect on resorptive markers. Extraosseous matrix synthesis was suppressed by prednisolone evaluated by serum procollagen type III N-terminal propeptide (max. -30.8%, p < 0.001) and was not affected by concomitant treatment with calcitriol or calcitriol alone. In conclusion, short-term administration of prednisolone to healthy men leads to fast and protracted suppression of biochemical markers of bone formation and extraosseous connective tissue metabolism. The effect on bone was partially antagonized by simultaneous calcitriol treatment, and points toward a potential role of calcitriol in the prevention of steroid induced osteoporosis.

Adult↗
PubMed1997

Shoulder fusion for paralyzed upper limb.

Fusion of the shoulder joint after a brachial plexus injury is a well known procedure in cases of flail shoulder in combination with normal motor and sensory function in the band. However, in combination with modern orthoses to stabilize the elbow, fusion of the shoulder in cases of a totally flaccid and afunctional arm might be more beneficial. In a retrospective study the impact of shoulder fusion on daily abilities in a population with a completely flaccid arm caused by a brachial plexus injury was investigated. Compared with a similar population, consisting of 16 patients with an afunctional unstable shoulder, all 12 patients who underwent shoulder fusion proved to perform at a higher functional level. Shoulder fusion in combination with an elbow stabilizing orthosis for a completely flaccid upper limb is a beneficial procedure that leads to less disability and results in a better quality of life.

Brachial Plexus↗
PubMed1997

Knemometry, urine cortisol excretion, and measures of the insulin-like growth factor axis and collagen turnover in children treated with inhaled glucocorticosteroids.

Correlations between knemometric (lower leg length) growth rates and urine free cortisol excretion, respectively, and serum concentrations of IGF-I, IGF binding protein-3, osteocalcin, carboxy terminal propeptide of type I collagen (PICP), carboxy terminal pryridinoline cross-linked telopeptide of type I procollagen (ICTP), and amino terminal propeptide of type III procollagen (PIIINP) were investigated in 17 asthmatic children aged 7-14 y during treatment with fluticasone propionate, 200 micrograms, and beclomethasone dipropionate, 400 and 800 micrograms/d, taken from dry powder inhalers. The study was a double blind, crossover trial with three active treatment periods and two wash-out periods. All periods were 15 d long. Overnight urine free cortisol/ creatinine x 10(6) did not correlate with knemometric growth rates or any of the serum markers. Significant correlations (Pearson's correlation coefficient, P) between knemometric growth rates and IGF-I (0.41; 0.006), IGFBP-3 (0.35; 0.02), PICP (0.44; 0.003), ICTP (0.35; 0.001), and PIIINP (0.46; 0.002) were found. Compared with fluticasone propionate, 200 micrograms, beclomethasone dipropionate, 400 and 800 micrograms, caused significant suppression of lower leg growth rate (F = 12.41; p = 0.002, and F = 23.30; p = 0.0001, respectively) and of urine free cortisol/creatinine x 10(6) (F = 10.52; p = 0.003, and F = 13.74; p = 0.001). Beclomethasone, 800 micrograms, caused suppression of PICP compared with fluticasone propionate, 200 micrograms (F = 8.31; p = 0.008), and beclomethasone, 400 micrograms (F = 7.53; p = 0.01). Both low (F = 6.82; p = 0.02) and high (F = 23.35; p = 0.0001) doses of beclomethasone were associated with reduced concentrations of ICTP, the high dose being the most suppressive (F = 4.42; p = 0.05). Beclomethasone 400 (F = 9.75; p = 0.004) and 800 micrograms (F = 23.61; p = 0.0001) resulted in reduced levels of PIIINP. Reduced short-term knemometric growth rates in children treated with inhaled glucocorticosteroids reflect suppressive effects on type I and type III collagen turnover.

Administration, Inhalation↗
PubMed1996

Meniscal replacement using a porous polymer prosthesis: a preliminary study in the dog.

A porous polyurethane prosthesis was used to replace the lateral meniscus in the dog. After an initial ingrowth of fibrous tissue, the prostheses became filled with tissue strongly resembling normal meniscal fibrocartilage. Although less severe than seen after total meniscectomy, cartilage degeneration was frequent, possibly because tissue ingrowth in the prostheses occurred too slowly. Porous polymers can be useful for replacement of the meniscus, provided that chemical and physical properties are optimized.

Animals↗
PubMed1996

Meniscal repair by fibrocartilage in the dog: characterization of the repair tissue and the role of vascularity.

Lesions in the avascular part of 20 canine menisci were repaired by implantation of a porous polyurethane. Seven menisci were not repaired and served as controls. The repair tissue was characterized by biochemical and immunological analysis. The role of vascularity in healing was studied by perfusion of menisci with Indian ink. Histologically, repair tissue inside the implants initially consisted of fibrous tissue containing type I collagen. After 2 months, fibrocartilaginous tissue developed inside the implants, whereas control defects only showed repair with fibrous tissue. Both type I and type II collagen, the two major collagen types of normal meniscal fibrocartilage, could be detected in this newly formed fibrocartilage. The implant guided vascular tissue from the periphery towards the lesion resulting in healing of the tear. After fibrocartilage had formed, vascularity decreased and was completely absent in mature fibrocartilage. Control defects remained filled with vascular connective tissue. Two-thirds of the longitudinal lesions were found to be healed partially or completely. It is concluded that implantation of a porous polymer does enhance vascularity sufficiently to result in healing of meniscal lesions extending into the avascular part. Healing takes place by repair tissue strongly resembling normal meniscal fibrocartilage.

Animals↗
PubMed1996

Dose-response effect of short-term calcitriol treatment on bone and mineral metabolism in normal males.

To evaluate the effects of short-term treatment with calcitriol on biochemical markers of calcium and bone metabolism, 36 normal male volunteers (aged 21-54 years) were randomized to oral treatment for 7 days with either (A) calcitriol, 1 microgram twice daily, (B) calcitriol, 0.5 microgram twice daily, or (C) placebo twice daily. Serum calcium increased slightly in a dose-dependent manner (maximal increase 2.5%, p < 0.05) followed by a heavy increase in both 24 h (max. 156.1%, p < 0.001) and fasting urinary calcium excretion (max. 123.1%, p < 0.001), and a striking reduction in serum PTH (max. -43.1%, p < 0.001). Biochemical markers of osteoblast activity and bone formation increased immediately in a dose-dependent manner [serum osteocalcin (max. 37.8%, p < 0.03) and serum procollagen type I C-terminal propeptide (PICP) (max. 26.0%, p < 0.05)], whereas there was no effect on serum bone alkaline phosphatase. Calcitriol treatment had no effect on biochemical markers of bone resorption [serum C-terminal telopeptide of type I collagen (ICTP) and fasting urinary excretion of hydroxyproline/creatinine (OHP)]. Extraosseous collagen matrix synthesis was not affected evaluated by serum procollagen type III N-terminal propeptide (PIIINP). In the follow-up period (15 weeks) no unequivocal changes were observed. The fast and protracted increase in biochemical markers of osteoblast activity and bone formation, without affecting bone resorption and extraosseous connective tissue metabolism points toward a selective effect of calcitriol on bone matrix formation.

Administration, Oral↗
PubMed1996

Insulin-like growth factor axis, bone and collagen turnover in children with atopic dermatitis treated with topical glucocorticosteroids.

BACKGROUND: Topical glucocorticosteroids are widely used in the treatment of children with atopic dermatitis. Due to percutaneous absorption, these agents may become systemically available and cause inhibition of growth in children. However, the mechanisms responsible for the growth-suppressive effective are not fully understood. OBJECTIVE: To evaluate whether treatment with topical budesonide has any adverse effects on growth-hormone-dependent serum levels of insulin-like growth factor I (IGF-I) and insulin-like growth factor binding protein 3 (IGFBP-3), and on the serum markers of bone and collagen turnover osteocalcin, the carboxy-terminal propeptide of type I collagen (PICP), the carboxy-terminal pyridinoline cross-linked telopeptide of type I collagen (ICTP) and the amino-terminal propeptide of type III procollagen (PIIINP). METHODS: 13 children (mean age 9.5 years) with atopic dermatitis were studied in an open longitudinal trial with run-in and budesonide treatment periods of 2 weeks' duration. During the run-in, only emollient was used. During the treatment period, budesonide cream 0.025% followed by emollient were applied twice daily all over the body except on the face. At day 14 of each period, blood samples were taken and eczema was scored according to a severity index based on extent and activity of the disease. RESULTS: Compared to the run-in, budesonide treatment was associated with a statistically significant reduction in mean severity index (p = 0.002). No statistically significant effects on serum levels of IGF-I, IGFBP-3, osteocalcin or ICTP were observed. The serum concentrations of PICP and PIIINP were reduced with (mean +/- 1 SD) 43 +/- 64 milligrams (95% confidence interval 3.5-80 milligrams, p = 0.03, t = 2.4, d.f. = 12) and 1.2 +/- 1.5 milligrams (95% confidence interval 0.3-2.1 milligrams, p = 0.01, t = 3.0, d.f. = 12), respectively. CONCLUSION: Type I and III collagen turnover may be suppressed during short-term treatment with topical budesonide in children with atopic eczema. clinical implications need further study.

Administration, Topical↗
PubMed1995

[Anticoagulant and thrombolytic therapy in deep venous thrombosis and pulmonary embolism].

During the last 10 years anticoagulant (AC) therapy and thrombolytic treatment of venous thromboembolism (VT) have been evaluated in randomized studies. Adjusted subcutaneous (s.c.) heparin and low molecular weight heparin (LMWH) are found at least as effective as intravenous (i.v.) infusion of heparin in deep venous thrombosis (DVT) without an increased bleeding risk. In pulmonary embolism (PE) randomized trials assessing the efficacy of s.c. heparin and LMWH are missing. Oral AC-treatment can be initiated from the first or second day in VT. The recommended duration is three months for medical patients, and 4 weeks seem appropriate for surgical patients that are completely mobilized and without persisting predisposing factors. Long-term efficacy of thrombolytic treatment of DVT has only been assessed in small trials showing a trend towards reduced risk of developing chronic venous insufficiency. Short-term thrombolytic treatment of DVT is evaluated in ongoing trials. In the treatment of PE short-term thrombolysis with either t-PA or urokinase is found to be as effective as long-term thrombolytic treatment with a reduced bleeding risk. Thrombolytic therapy rapidly reduces embolic mass and stabilizes haemodynamics, but mortality and long-term efficacy of thrombolysis and AC-treatment versus AC-treatment alone in PE are being assessed in ongoing studies.

Anticoagulants↗
PubMed1995

[Interaction between thrombocytes and blood vessel wall--significance for acute ischemic coronary syndromes].

Intracoronary thrombus formation is the essential pathogenic substrate for the development of the acute ischaemic coronary syndromes (unstable angina pectoris (UAP), acute myocardial infarction (MI) and sudden cardiac death). Rupture of an atherosclerotic plaque has been shown to be of major importance for initiation of the thrombogenic process, but the reactivity of the circulating platelets and their interaction with the coronary vessel wall are also important for the formation and propagation of the intracoronary thrombus. The evidence favouring the role of platelets is: 1) the aggregability of platelets is increased in the morning where the incidence of MI and sudden cardiac death has been shown to be high, 2) shortened bleeding time and increased mean platelet volume in the acute phase of MI, 3) the synthesis of proaggregatory thromboxane A2 is increased in the acute phase of MI and in UAP, 4) a high platelet count and an increased ADP-induced platelet aggregation predispose to MI and death in healthy males, 5) high mean platelet volume and increased spontaneous platelet aggregation are risk factors for MI and death in patients with a recent MI, 6) the platelet inhibitor, acetylsalicylic acid, has been shown to reduce the incidence of MI and mortality in patients with silent myocardial ischaemia, stable and unstable angina pectoris and in patients with MI.

Angina, Unstable↗
PubMed1995

Short-term treatment with growth hormone stimulates osteoblastic and osteoclastic activity in osteopenic postmenopausal women: a dose response study.

To investigate the potential use of growth hormone (GH) in Activate-Depress-Free-Repeat treatment of postmenopausal osteoporosis, we measured changes in serum levels of biochemical markers of bone turnover, insulin-like growth factor-I (IGF-I), calciotropic hormones, and bone mineral density in 40 postmenopausal women with osteopenia (ages 52-73 years) in response to 7 days of treatment with either placebo or GH (0.05, 0.10, or 0.20 IU/kg/day) administered subcutaneously in the evening. GH treatment increased serum osteocalcin (p < 0.01) and C-terminal type-I procollagen propeptide (p < 0.01) and also serum levels of type-I collagen telopeptide (p < 0.001), fasting urinary hydroxyproline/creatinine (p < 0.05), pyridinoline/creatinine (p < 0.05), and deoxypyridinoline/creatinine (p < 0.01) in a dose-dependent fashion. Even the lowest dose of GH tested induced a significant increase in these parameters; however, the effects were transient lasting only 1-2 weeks. In the highest dose group, however, a somewhat prolonged effect (30 days) on serum osteocalcin was observed. Furthermore, GH increased serum levels of IGF-I, insulin, and tri-iodothyronin. No effect on serum 1,25-dihydroxyvitamin D3 or parathyroid hormone could be demonstrated. Adverse effects were mainly related to fluid retention. They were clearly dose-dependent and rapidly reversible. In conclusion, short-term GH treatment stimulates bone formation and bone resorption in postmenopausal women with osteopenia.

Aged↗
PubMed1995

Irradiation of bone metastases in breast cancer patients: a randomized study with 1 year follow-up.

The results from a prospective randomized trial comparing two different radiation schedules for treatment of painful bone metastases in women with recurrent breast cancer are presented. A total of 217 patients with painful bone metastases were randomized to either 30 Grey (Gy) in ten fractions, five fractions a week (5F/W) or 15 Gy in three fractions 2F/W. The effect of treatment was evaluated by pain assessment, the radiological response and the degree of side-effects. The patients were rated at start of treatment and after 1, 3, 6 and 12 months. No difference between the two radiation regimes was found, neither in achieved pain relief, improvement in level of activity and medication, nor was there any difference in radiological response and side-effects from treatment. Both regimes resulted in a significant improvement in both pain score and level of activity 1 month after treatment, an improvement which persisted during the follow-up period. We conclude that 15 Gy given in three fractions 2F/W is as effective as 30 Gy in ten fractions 5F/W, but more convenient to the patient and of less cost to society.

Adult↗
PubMed1995

Physical examinations and laboratory tests in antenatal care visits in Denmark. Do reported practice and current official guidelines concord with results of literature reviews? A nationwide study of the public scheme of shared antenatal care in general practice, centres of midwifery and hospital outpatients' clinics.

OBJECTIVE: To analyse physical examinations and laboratory tests reported in antenatal care visits in relation to official guidelines and reviews of appropriateness. DESIGN: A nationwide cross sectional study based on questionnaires completed by general practitioners (GPs), midwives, and hospital doctors. Physical examinations and laboratory tests in connection with one specific visit were reported. SUBJECTS: The questionnaires were completed by 722 GPs (61% of eligible from a random sample), 584 midwives (86% of eligible), 250 hospital doctors who made health examinations in pregnancy, week 16-18 (63% of eligible), and 181 hospital doctors who saw women with at-risk pregnancies (55% of eligible). RESULTS: General practice: weight, blood pressure (BP) measurement, and test for proteinuria were reported in more than 90% of visits. Urine culture was reported in 46%, and cervical smear in 41% of first visits. Rubella antibody test at the first visit was only reported in 23% of nulliparae. Vaginal examination was reported in 95% of first visits. Fewer were reported in second (27%) and third (48%) routine visits during pregnancy. Midwives: checks of BP, oedema, and proteinuria were reported in more than 95% of visits irrespective of week of gestation. Vaginal examination was reported in about a third of checkups. Hospitals: vaginal examination was reported in 66% of checkups in at-risk pregnancies. CONCLUSIONS: A surplus of resources were spent on (repeat) examinations and tests with little or no documented benefit. Cervical cytology was grossly overused. Urine culture and rubella serology were not sufficiently applied.

Clinical Laboratory Techniques↗