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Biomedical subjects

P S Hansen

Publications and source records attributed to P S Hansen.

At least 19 recordsLinked to original sources
PubMed2006

Yersinia enterocolitica infection does not confer an increased risk of thyroid antibodies: evidence from a Danish twin study.

Understanding of the aetiological basis of thyroid autoimmunity may be gained by studying the early stages of the disease process. We aimed to (1) investigate the relationship between thyroid antibody status and Yersinia enterocolitica (YE) infection in euthyroid subjects and (2) explore the relative importance of genetic and environmental risk factors in the acquisition of YE infection. The association between thyroid antibody status and YE infection was explored using a case-control design. Furthermore, thyroid antibody-positive twins were compared with their thyroid antibody-negative co-twin. In 468 twins, IgA and IgG antibodies to virulence-associated outer-membrane proteins (YOPs) of YE were measured. Of these, 147 were thyroid antibody-positive (cases). A total of 147 age- and gender-matched twins were chosen as controls. The prevalence of YOP antibodies was lower among thyroid antibody-positive individuals than among controls. Yersinia infection was not associated with a positive thyroid antibody status: the odds ratio (with 95% CI) for YOP IgA-ab was 0.66 (0.42-1.05), P = 0.078 and for YOP IgG-ab it was 0.95 (0.60-1.50), P = 0.816. Within discordant twin pairs, the thyroid antibody-positive twin did not have an increased risk of Yersinia infection compared to the thyroid antibody-negative co-twin [odds ratio: YOP IgA-Ab: 0.94 (0.49-1.83), P = 0.866, and YOP IgG-Ab: 1.35 (0.72-2.53), P = 0.345]; 41% (95% CI 10-67% of the liability of being YOP antibody-positive was due to genetic effects. In conclusion, Yersinia infection does not confer an increased risk of thyroid antibodies. The genetic contribution in the acquisition of Yersinia infection is modest.

Adult↗
PubMed2006

Apical sparing in tako-tsubo cardiomyopathy.

BACKGROUND: Tako-tsubo cardiomyopathy (TTC) is an acute reversible cause of segmental myocardial dysfunction that is poorly understood. We have noted a variant of this condition where a tiny segment at the apex retains some contractile function. This paper delineates the frequency of this variant relative to the classical form and the clinical differences between patients suffering from the two forms. METHODS: All cases of TTC (n = 35) were identified from our infarct angiography database and separated on the basis of apical sparing (n = 14) or no apical sparing (n = 21). RESULTS: Compared with the classical form, those with apical sparing were significantly younger (63 +/- 12 vs 72 +/- 13 years) and were more likely premenopausal (5/14 vs 0/21) and had higher ejection fractions (35 +/- 6% vs 32 +/- 4%). There was a trend towards higher recurrence (4/21 vs 0/14). There were no differences in time or season of presentation, precipitant stressor, premorbid drug therapy, haemodynamics at catheterization or acute outcomes. CONCLUSION: The apical sparing variant of TTC is common, accounting for 40% of cases. While the patients are younger and more likely premenopausal, there are no other distinguishing features between the classical and the variant form.

Age Factors↗
PubMed2002

Additive effects of Helicobacter pylori lipopolysaccharide and proteins in monocyte inflammatory responses.

BACKGROUND: Chronic active gastritis associated with Helicobacter pylori infection is characterized by both a neutrophil and a mononuclear leukocyte infiltrate. While neutrophil functions in relation to H. pylori are well described, the interactions between Helicobacter bacterial factors and monocytes are poorly understood in relation to the mucosal inflammatory process. METHODS: Sonicates of a clinical strain as well as of a type strain of H. pylori were prepared in vitro. Monocytes from healthy donors were induced to release L-selectin (CD62L), to upregulate the adherence molecules (CD11a, CD11b. CD11c) and to produce toxic oxygen radicals. The inducing activities were assessed by flow cytometry and chemiluminescence. RESULTS: A dose-dependent shedding of CD62L and upregulation of CD11b and CD11c were observed with both bacterial strains as well as PMA and fMLP. CD11a remained unchanged. Activity could be attributed to bacterial factors of both lipopolysaccharide (LPS) and protein characteristics. The alterations observed for CD11b, CD11c and CD62L were induced by the same protein fractions in parallel. suggesting a common component and mechanism of action. A major protein component was urease, although other minor protein bands were found as well. Monoclonal antibodies to CD14-inhibited monocyte inflammatory responses induced by H. pylori sonicate at low concentration, whereas further LPS pierce-matrix reduction was necessary at high sonicate concentrations to reduce monocyte-inducing activity. CONCLUSIONS: Monocyte inflammatory activation is induced by H. pylori sonicate components. Factors of both LPS and protein characteristics are involved and an additive effect was demonstrated. Urease appears to be a major component in the protein preparations of highest inducing capacity. Further studies are warranted to assess whether the monocyte activation properties described here are related to the diversity of clinical gastroduodenal outcome for the chronic type B gastritis associated with H. pylori infection.

Bacterial Proteins↗
PubMed2001

Inflammatory activation of neutrophils by Helicobacter pylori; a mechanism insensitive to pertussis toxin.

Chronic active gastritis of the antral mucosa is a characteristic feature of infection with Helicobacter pylori and interactions between bacterial components and inflammatory cells are believed to play an important pathogenic role. Neutrophils stimulated with H. pylori sonicate were demonstrated to release L-selectin (CD62L) expressed on the cellular surface, with a subsequent up-regulation of the beta2-integrins CD11b and CD11c, both in a dose- and time-dependent manner, reaching maximum levels after 45-60 min of stimulation. No changes were observed for the CD11a receptor upon stimulation. The activating properties of H. pylori sonicates on neutrophils were heat-labile and susceptible to protease attack, indicating the protein nature of the activating factor. After size fractionation, the major neutrophil-inducing activity was detected in the high molecular weight fraction exhibiting urease activity. Pertussis toxin was unable to inhibit neutrophil activation by the H. pylori protein(s). We conclude that proteins from H. pylori have a potent inflammatory effect on the surface membrane molecules CD62L, CD11b and CD11c essential for transendothelial migration of neutrophils to areas of inflammation. The neutrophil-activating protein(s) act via a pertussis toxin-insensitive mechanism.

CD18 Antigens↗
PubMed2001

Helicobacter felis does not stimulate human neutrophil oxidative burst in contrast to 'Gastrospirillum hominis' and Helicobacter pylori.

Helicobacter pylori is a human pathogen, whereas the natural hosts for 'Gastrospirillum hominis' and Helicobacter felis are animals. 'G. hominis' is occasionally found to cause infection in humans, whereas H. felis only rarely infects humans. The pathogenesis of H. pylori infection is not completely understood and in order to reveal differences in immune response to the three Helicobacter species, the upregulation of adherence molecule CD11b/CD18, chemotactic activity and oxidative burst response of neutrophils after stimulation with H. pylori, 'G. hominis' and H. felis sonicates, were compared. Like H. pylori, 'G. hominis' and H. felis induced upregulation of CD11b/CD18 and chemotaxis of neutrophils. 'G. hominis' demonstrated a more pronounced upregulation of CD11b/CD18, whereas H. felis was the strongest stimulant of neutrophil chemotaxis. H. felis was unable to stimulate neutrophils to oxidative burst response, whereas 'G. hominis' activated neutrophils in a dose-dependent way similar to H. pylori. 'G. hominis' and H. felis were both able to prime neutrophils for oxidative burst response similar to H. pylori. In conclusion, we observed clear differences in neutrophil responses to different Helicobacter species, which indicates that bacterial virulence factors may be important for the diversity in the pathogenetic outcome of Helicobacter infections.

Bacterial Proteins↗
PubMed2001

Protein kinase Cepsilon contributes to regulation of the sarcolemmal Na(+)-K(+) pump.

A reduction in angiotensin II (ANG II) in vivo by treatment of rabbits with the angiotensin-converting enzyme inhibitor, captopril, increases Na(+)-K(+) pump current (I(p)) of cardiac myocytes. This increase is abolished by exposure of myocytes to ANG II in vitro. Because ANG II induces translocation of the epsilon-isoform of protein kinase C (PKCepsilon), we examined whether this isozyme regulates the pump. We treated rabbits with captopril, isolated myocytes, and measured I(p) of myocytes voltage clamped with wide-tipped patch pipettes. I(p) of myocytes from captopril-treated rabbits was larger than I(p) of myocytes from controls. ANG II superfusion of myocytes from captopril-treated rabbits decreased I(p) to levels similar to controls. Inclusion of PKCepsilon-specific blocking peptide in pipette solutions used to perfuse the intracellular compartment abolished the effect of ANG II. Inclusion of psiepsilonRACK, a PKCepsilon-specific activating peptide, in pipette solutions had an effect on I(p) that was similar to that of ANG II. There was no additive effect of ANG II and psiepsilonRACK. We conclude that PKCepsilon regulates the sarcolemmal Na(+)-K(+) pump.

Angiotensin II↗
PubMed2000

[Vasospastic angina pectoris following abortion induced by prostaglandin analogue].

A case of vasospastic angina pectoris with loss of consciousness, bradycardia and seizures induced by medical abortion following administration of mifepristone and gemeprost is reported. The patient had a history of smoking and migraine, and former treatment with ergot alkaloids or serotonin agonists had also resulted in chest pain and lipothymia. The case underlines the importance of obtaining a detailed history of vasospastic disorders in women referred for medical abortion.

Abortifacient Agents, Steroidal↗
PubMed2000

The apolipoprotein epsilon4 allele determines prognosis and the effect on prognosis of simvastatin in survivors of myocardial infarction : a substudy of the Scandinavian simvastatin survival study.

BACKGROUND: Carriers of the epsilon4 allele of the apolipoprotein E gene are at a higher risk of coronary heart disease than individuals with other genotypes. We examined whether the risk of death or a major coronary event in survivors of myocardial infarction depended on apolipoprotein E genotype and whether the benefits of treatment with simvastatin differed between genotypes. METHODS AND RESULTS: Cox proportional hazards models were used to analyze 5.5 years of follow-up data from 966 Danish and Finnish myocardial infarction survivors enrolled in the Scandinavian Simvastatin Survival Study. A total of 16% of the 166 epsilon4 carriers in the placebo group died compared with 9% of the 312 patients without the allele, which corresponds to a mortality risk ratio of 1.8 (95% confidence interval, 1.1 to 3.1). The risk ratio was unaffected by considerations of sex, age, concurrent angina, diabetes, smoking, and serum lipids in multivariate analyses. Simvastatin treatment reduced the mortality risk to 0.33 (95% confidence interval, 0.16 to 0.69) in epsilon4 carriers and to 0.66 (95% confidence interval, 0. 35 to 1.24) in other patients (P=0.23 for treatment by genotype interaction). Apolipoprotein E genotype did not predict the risk of a major coronary event. Baseline serum levels of lipoprotein(a) also predicted mortality risk and could be combined with epsilon4-carrier status to define 3 groups of patients with different prognoses and benefits from treatment. CONCLUSIONS: Myocardial infarction survivors with the epsilon4 allele have a nearly 2-fold increased risk of dying compared with other patients, and the excess mortality can be abolished by treatment with simvastatin.

Adult↗
PubMed2000

Cigarette smoking and risk of clinically overt thyroid disease: a population-based twin case-control study.

BACKGROUND: The effects of cigarette smoking on the thyroid gland have been studied for years. However, the effect of smoking on thyroid function and size is still controversial. OBJECTIVE: To determine the impact of cigarette smoking on the development of clinically overt thyroid disease. METHODS: Matched case-control study of 132 same-sex twin pairs (264 individuals) discordant for clinically overt thyroid disease, ascertained from a population-based nationwide twin register. Information on thyroid disease and smoking habits was gathered by questionnaire, and the patients' endocrinologist or general practitioner verified the diagnosis. RESULTS: Overall, smoking was associated with an increased risk of developing clinically overt thyroid disease (odds ratio, 3.0; 95% confidence interval, 1.4-6.6; P = .003). This association remained statistically significant in monozygotic and dizygotic disease-discordant pairs. The effect of smoking was more pronounced in monozygotic vs dizygotic pairs (odds ratio, 5.0 vs 2.5; P= .04 for both). Essentially similar results were obtained after subdividing the twin pairs into groups discordant for clinically overt autoimmune (49 pairs) and nonautoimmune (83 pairs) thyroid disease. Among twin pairs concordant for smoking, probands with clinically overt autoimmune thyroid disease smoked significantly more than did their healthy co-twins (17 pairs; P= .03), whereas no difference was found between probands with nonautoimmune thyroid disease and their healthy co-twins (34 pairs; P= .20). CONCLUSIONS: Smoking is associated with an increased risk of developing clinically overt thyroid disease. Furthermore, our data suggest that cumulative cigarette consumption is a risk factor, most pronounced in autoimmune thyroid disease.

Autoimmunity↗
PubMed2000

[Percutaneous transluminal septal myocardial ablation in hypertrophic obstructive cardiomyopathy. A new therapeutic option].

We here report on the PTSMA results in four HOCM patients having severe symptoms despite medical treatment and dual chamber pacing. Between two and five ml of ethanol was injected in one or two septal branches from the left coronary artery. Six months after treatment the pressure gradient across the left ventricular outflow tract was reduced between 25-80 mmHg at rest and between 55-180 mmHg at exercise. There was an increase in functional capacity of about two NYHA-classes. Two patients developed permanent right bundle branch block, and one patient with pre-existing left bundle branch block developed persistent total atrioventricular block after the treatment. Serum creatine phosphokinase MB increased on average to 146 U/l. No other complications were seen. In conclusion, our initial PTSMA results seems promising.

Adult↗
PubMed2000

HMG CoA reductase inhibition reduces sarcolemmal Na(+)-K(+) pump density.

OBJECTIVES: HMG CoA reductase inhibitors reduce cellular availability of mevalonate, a precursor in cholesterol synthesis. Since the cholesterol content of cell membranes is an important determinant of Na(+)-K(+) pump function we speculated that treatment with HMG CoA reductase inhibitors affects Na(+)-K(+) pump activity. METHODS: We treated rabbits and rats for 2 weeks with the HMG CoA reductase inhibitor lovastatin and measured Na(+)-K(+) pump current (I(p)) in isolated rabbit cardiac myocytes using the whole cell patch-clamp technique, K-dependent p-nitrophenyl phosphatase (p-NPPase) activity in crude myocardial and skeletal muscle homogenates, and vanadate-facilitated 3H-ouabain binding in intact skeletal muscle samples from rats. RESULTS: Treatment with lovastatin caused statistically significant reductions in I(p), myocardial and skeletal muscle K-dependent p-NPPase activity and 3H-ouabain binding in the myocardium and skeletal muscle. The lovastatin-induced decrease in I(p) was eliminated by parenteral co-administration of mevalonate. However, this was not related to cardiac cholesterol content. CONCLUSIONS: Treatment with lovastatin reduces Na(+)-K(+) pump activity and abundance in rabbit and rat sarcolemma.

4-Nitrophenylphosphatase↗
PubMed2000

Voltage-dependent stimulation of the Na(+)-K(+) pump by insulin in rabbit cardiac myocytes.

Insulin enhances Na(+)-K(+) pump activity in various noncardiac tissues. We examined whether insulin exposure in vitro regulates Na(+)-K(+) pump function in rabbit ventricular myocytes. Pump current (I(p)) was measured using the whole-cell patch-clamp technique at test potentials (V(m)s) from -100 to +60 mV. When the Na(+) concentration in the patch pipette ([Na](pip)) was 10 mM, insulin caused a V(m)-dependent increase in I(p). The increase was approximately 70% when V(m) was at near physiological diastolic potentials. This effect persisted after elimination of extracellular voltage-dependent steps and when K(+) and K(+)-congeners were excluded from the patch pipettes. When [Na](pip) was 80 mM, causing near-maximal pump stimulation, insulin had no effect, suggesting that it did not cause an increase in membrane pump density. Effects of tyrphostin A25, wortmannin, okadaic acid, or bisindolylmaleimide I in pipette solutions suggested that the insulin-induced increase in I(p) involved activation of tyrosine kinase, phosphatidylinositol 3-kinase, and protein phosphatase 1, whereas protein phosphatase 2A and protein kinase C were not involved.

Androstadienes↗
PubMed2000

Flow cytometric assessment of LDL ligand function for detection of heterozygous familial defective apolipoprotein B-100.

BACKGROUND: Familial defective apolipoprotein (apo) B-100 (FDB) is caused by a mutation in the apoB gene and characterized by decreased binding of LDL to LDL receptors because of reduced function of the apoB-100 ligand. FDB may be associated with severe hypercholesterolemia and cannot always be distinguished from familial hypercholesterolemia phenotypically. METHODS: We used a fluorescence flow cytometry assay with Epstein-Barr virus-transformed lymphocytes to detect reduced LDL ligand function by competitive binding with fluorescently conjugated LDL (DiI-LDL). The assay was tested and validated using LDL from patients heterozygous for the Arg(3500)-Gln mutation and their first-degree relatives. Knowing the actual apoB genotype of patients and relatives allowed us to assess the ability of the assay to predict the results of DNA analysis. The results were compared to measurements of LDL ligand function in unrelated healthy control subjects to characterize functionally the Arg(3500)-Gln mutation. RESULTS: Fluorescence was significantly increased in cells incubated with DiI-LDL in competition with unlabeled LDL from FDB(R3500Q) heterozygotes compared with cells incubated with DiI-LDL in competition with unlabeled LDL from relatives or unrelated healthy control subjects. Thus, patients heterozygous for the Arg(3500)-Gln mutation had significantly reduced LDL ligand function. The binding affinity of LDL from FDB(R3500Q) heterozygotes was 32% of that in non-FDB relatives and healthy controls. The assay had a diagnostic sensitivity of 0.95 and diagnostic specificity of 0.89. CONCLUSIONS: The diagnostic accuracy of the assay was too low to allow reliable diagnosis of individual cases of heterozygous FDB(R3500Q). However, fluorescence flow cytometry may supplement genetic identification of FDB and functionally characterize gene mutations associated with major reductions in LDL ligand function.

Adult↗
PubMed1999

[Thyrotoxic periodic paralysis].

Thyrotoxic periodic paralysis (TPP) is a rare complication of hyperthyroidism mainly seen in patients of Oriental origin and is rarely encountered in Western countries. TPP clinically resembles familial periodic paralysis with recurrent episodes of weakness or flaccid paralysis of especially the legs. Transient hypokalaemia is regularly observed during attacks and remission can be achieved by administration of potassium salts. The definitive treatment of TPP is to restore euthyroidism. This case describes a thyrotoxic patient who initially presented with periodic paralysis.

Adult↗
PubMed1999

A primary stenting strategy as an alternative to fibrinolytic therapy in acute myocardial infarction. An analysis of results in hospital and at 6 weeks and 6 months.

OBJECTIVE: To report the feasibility and results to 6 months of a primary stenting strategy in patients with acute myocardial infarction (AMI). DESIGN: Prospective, single-centre, observational study. SETTING: A tertiary referral teaching hospital (Royal North Shore Hospital, Sydney), July 1997 to November 1998. SUBJECTS: 102 (of 194) consecutive patients presenting to the emergency department with AMI who were eligible for fibrinolytic therapy, and for a primary stenting strategy. The first 50 patients were under 70 years of age, and had not had previous coronary artery bypass grafting (CABG). The following 52 patients included patients up to 80 years and with previous CABG. OUTCOME MEASURES: Major adverse cardiac and cerebrovascular events: death, reinfarction, cerebrovascular accident (CVA) and repeat target lesion revascularisation, in hospital, and at 6 weeks and 6 months. Minor in-hospital adverse events: bleeding requiring blood transfusion, vascular complications and new-onset heart failure. Time delays to treatment, and duration of hospital stay. RESULTS: Normal flow was established in the infarct-related artery in 97/102 patients (95%). Stenting, percutaneous transluminal coronary angioplasty (PTCA), CABG or medical therapy was performed in 74, 11, 9 and 8 patients, respectively. Minor in-hospital events, time delays and hospital stay were similar to those reported previously. At 6 weeks, major adverse cardiac and cerebrovascular events had occurred in 5% of patients (four repeat target lesion revascularisation and one reinfarction). By 6 months, repeat target lesion revascularisation had been performed in an additional 10% of patients. No deaths had occurred. CONCLUSIONS: A primary stenting strategy can be performed safely, without significant delays and with excellent short and intermediate term outcomes.

Adult↗
PubMed1999

Postoperative radiotherapy in high-risk postmenopausal breast-cancer patients given adjuvant tamoxifen: Danish Breast Cancer Cooperative Group DBCG 82c randomised trial.

BACKGROUND: Postmastectomy radiotherapy is associated with a lower locoregional recurrence rate and improved disease-free and overall survival when combined with chemotherapy in premenopausal high-risk breast-cancer patients. However, whether the same benefits apply also in postmenopausal women treated with adjuvant tamoxifen for similar high-risk cancer is unclear. In a randomised trial among postmenopausal women who had undergone mastectomy, we compared adjuvant tamoxifen alone with tamoxifen plus postoperative radiotherapy. METHODS: Between 1982 and 1990, postmenopausal women with high-risk breast cancer (stage II or III) were randomly assigned adjuvant tamoxifen (30 mg daily for 1 year) alone (689) or with postoperative radiotherapy to the chest wall and regional lymph nodes (686). Median follow-up was 123 months. The endpoints were first site of recurrence (locoregional recurrence, distant metastases, or both), and disease-free and overall survival. FINDINGS: Locoregional recurrence occurred in 52 (8%) of the radiotherapy plus tamoxifen group and 242 (35%) of the tamoxifen only group (p<0.001). In total there were 321 (47%) and 411 (60%) recurrences, respectively. Disease-free survival was 36% in the radiotherapy plus tamoxifen group and 24% in the tamoxifen alone group (p<0.001). Overall survival was also higher in the radiotherapy group (385 vs 434 deaths; survival 45 vs 36% at 10 years, p=0.03). INTERPRETATION: Postoperative radiotherapy decreased the risk of locoregional recurrence and was associated with improved survival in high-risk postmenopausal breast-cancer patients after mastectomy and limited axillary dissection, with 1 year of adjuvant tamoxifen treatment. Improved survival in high-risk breast cancer can best be achieved by a strategy of both locoregional and systemic tumour control.

Antineoplastic Agents, Hormonal↗
PubMed1999

Alpha-cardiac actin is a novel disease gene in familial hypertrophic cardiomyopathy.

We identified the alpha-cardiac actin gene (ACTC) as a novel disease gene in a pedigree suffering from familial hypertrophic cardiomyopathy (FHC). Linkage analyses excluded all the previously reported FHC loci as possible disease loci in the family studied, with lod scores varying between -2.5 and -6.0. Further linkage analyses of plausible candidate genes highly expressed in the adult human heart identified ACTC as the most likely disease gene, showing a maximal lod score of 3.6. Mutation analysis of ACTC revealed an Ala295Ser mutation in exon 5 close to 2 missense mutations recently described to cause the inherited form of idiopathic dilated cardiomyopathy (IDC). ACTC is the first sarcomeric gene described in which mutations are responsible for 2 different cardiomyopathies. We hypothesize that ACTC mutations affecting sarcomere contraction lead to FHC and that mutations affecting force transmission from the sarcomere to the surrounding syncytium lead to IDC.

Actins↗