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Biomedical subjects

M Holmström

Publications and source records attributed to M Holmström.

At least 19 recordsLinked to original sources
PubMed2006

Plasma acceleration above martian magnetic anomalies.

Auroras are caused by accelerated charged particles precipitating along magnetic field lines into a planetary atmosphere, the auroral brightness being roughly proportional to the precipitating particle energy flux. The Analyzer of Space Plasma and Energetic Atoms experiment on the Mars Express spacecraft has made a detailed study of acceleration processes on the nightside of Mars. We observed accelerated electrons and ions in the deep nightside high-altitude region of Mars that map geographically to interface/cleft regions associated with martian crustal magnetization regions. By integrating electron and ion acceleration energy down to the upper atmosphere, we saw energy fluxes in the range of 1 to 50 milliwatts per square meter per second. These conditions are similar to those producing bright discrete auroras above Earth. Discrete auroras at Mars are therefore expected to be associated with plasma acceleration in diverging magnetic flux tubes above crustal magnetization regions, the auroras being distributed geographically in a complex pattern by the many multipole magnetic field lines extending into space.

Journal Article↗
PubMed2006

Evaluation of low PAI-1 activity as a risk factor for hemorrhagic diathesis.

BACKGROUND: Prospective studies of the epidemiology and clinical significance of low plasminogen activator inhibitor type 1 (PAI-1) activity are lacking. OBJECTIVE: To evaluate the prevalence of low PAI-1 activity in patients with a bleeding tendency in comparison with a normal population. METHODS: In 586 consecutive patients, referred because of bleeding symptoms, we added analyses of PAI-1 activity and tissue plasminogen activator complex with PAI-1 (t-PA-PAI-1) to the routine investigation, consisting of platelet count, bleeding time, prothrombin time, activated partial thromboplastin time, fibrinogen, factor VIII, von Willebrand factor activity, and antigen. Controls were 100 blood donors and 100 age- and sex-matched healthy individuals. The latter were also evaluated regarding the previous bleeding episodes. The bleeding history was classified as clinically significant or not, and the criteria were fulfilled in 75% of the patients and 18% of the healthy controls. RESULTS: The routine laboratory investigation of the patients was negative in 57%. Low PAI-1 activity, defined as <1.0 U mL(-1), was found in 23% of the patients and in 13% and 10% of the blood donors and healthy controls, respectively (odds ratio and 95% CI, 2.04; 1.11-3.77 and 2.75; 1.39-5.42, respectively). The difference remained statistically significant after the adjustment for body mass index, use of estrogens, sex and age (odds ratio for patients vs. healthy controls 3.23; 95% CI, 1.22-8.56, P = 0.019). The distribution of the 4G/5G genotypes in the patients was not different from that of two control populations. No specific symptom predicted for low PAI-1, which did not aggravate the clinical picture in association with the other hemostatic defects. Low tPA-PAI-1 was not associated with the increased bleeding tendency. CONCLUSION: Low PAI-1 activity is common in patients with a bleeding diathesis, but it is a risk factor of minor clinical importance and not associated with specific bleeding manifestations.

Adolescent↗
PubMed2006

Post-thrombotic syndrome, recurrence, and death 10 years after the first episode of venous thromboembolism treated with warfarin for 6 weeks or 6 months.

BACKGROUND: The influence of the duration of anticoagulant therapy after venous thromboembolism (VTE) on the long-term morbidity and mortality is unclear. AIM: To investigate the long-term sequelae of VTE in patients randomized to different duration of secondary prophylaxis. METHODS: In a multicenter trial comparing secondary prophylaxis with vitamin K antagonists for 6 weeks or 6 months, we extended the originally planned 2 years follow-up to 10 years. The patients had annual visits and at the last visit clinical assessment of the post-thrombotic syndrome (PTS) was performed. Recurrent thromboembolism was adjudicated by a radiologist, blinded to treatment allocation. Causes of death were obtained from the Swedish Death Registry. RESULTS: Of the 897 patients randomized, 545 could be evaluated at the 10 years follow-up. The probability of developing severe PTS was 6% and any sign of PTS was seen in 56.3% of the evaluated patients. In multivariate analysis, old age and signs of impaired circulation at discharge from the hospital were independent risk factors at baseline for development of PTS after 10 years. Recurrent thromboembolism occurred in 29.1% of the patients with a higher rate among males, older patients, those with permanent triggering risk factor - especially with venous insufficiency at baseline - signs of impaired venous circulation at discharge, proximal deep vein thrombosis, or pulmonary embolism. Death occurred in 28.5%, which was a higher mortality than expected with a standardized incidence ratio (SIR) of 1.43 (95% CI 1.28-1.58), mainly because of a higher mortality than expected from cancer (SIR 1.83; 95% CI 1.44-2.23) or from myocardial infarction or stroke (SIR 1.28; 95% CI 1.00-1.56). The duration of anticoagulation did not have a statistically significant effect on any of the long-term outcomes. CONCLUSION: The morbidity and mortality during 10 years after the first episode of VTE is high and not reduced by extension of secondary prophylaxis from 6 weeks to 6 months. A strategy to reduce recurrence of VTE as well as mortality from arterial disease is needed.

Aged↗
PubMed2006

Assessment of the effect of endurance training on left ventricular relaxation with magnetic resonance imaging.

The purpose of the study was to assess the effect of endurance training on the early diastolic global and regional left ventricular (LV) relaxation with three magnetic resonance imaging (MRI) techniques. Fourteen subjects were examined with MRI before and after 3-month endurance training. Global early diastolic LV myocardial relaxation was assessed with mitral flow velocity mapping and regional LV early myocardial relaxation with myocardial tagging. LV end-diastolic and end-systolic volumes and mass were assessed with cine Magnetic resonance imaging (MRI). Mitral flow velocity mapping analysis revealed that the time to peak early filling shortened after training (before 112+/-32 ms, after 97+/-21, P<0.05), indicating more rapid global early myocardial relaxation. LV mass increased (97+/-19 g, 105+/-18, P<0.01) and end-systolic volume decreased (47+/-11 mL, 42+/-13, P<0.05). According to myocardial tagging analysis early myocardial relaxation in the septum and in the LV lateral wall increased (P<0.05). Regional tagging analysis showed enhanced myocardial relaxation in the basal septum (P<0.05). Global and regional LV early diastolic relaxation improved and physiological LV hypertrophy was found after the exercise training period for 3 months in healthy sedentary subjects.

Adult↗
PubMed2004

Solar wind-induced atmospheric erosion at Mars: first results from ASPERA-3 on Mars Express.

The Analyzer of Space Plasma and Energetic Atoms (ASPERA) on board the Mars Express spacecraft found that solar wind plasma and accelerated ionospheric ions may be observed all the way down to the Mars Express pericenter of 270 kilometers above the dayside planetary surface. This is very deep in the ionosphere, implying direct exposure of the martian topside atmosphere to solar wind plasma forcing. The low-altitude penetration of solar wind plasma and the energization of ionospheric plasma may be due to solar wind irregularities or perturbations, to magnetic anomalies at Mars, or both.

Journal Article↗
PubMed2002

Current perspectives on the treatment of nasal polyposis: a Swedish opinion report.

This Swedish study group has examined the current knowledge of nasal polyposis with emphasis on different treatment modalities. Polyposis is a multifactorial disease that exists for decades in the majority of cases. Different types of treatment must be considered, focusing on the underlying disease. However, as we only know the specific origin of polyposis in a minority of cases, treatment is usually symptomatic. When making a thorough evaluation of different treatment strategies, it is obvious that there is a real need for more controlled treatment studies which would make the scientific ground more stable when it comes to suggesting medical, surgical or combined treatments.

Administration, Intranasal↗
PubMed2001

Nasal symptoms and pathophysiology in farmers.

OBJECTIVES: Increased morbidity and mortality in lower airway diseases have been reported among farmers. The aim of this study was to assess upper airway problems in farmers. SUBJECTS AND METHODS: Twenty-five dairy farmers, 20 pig farmers, 21 grain farmers and 19 control subjects were studied, by use of questionnaire, skin-prick test, dynamic spirometry, nasal inspection, acoustic rhinometry (before and after a decongestant) as well as by determinations of the olfactory threshold and nasal lavage (NAL) concentrations of eosinophil cationic protein (ECP), myeloperoxidase (MPO) and albumin. RESULTS: Compared with the control group, farmers had more complaints of work-related symptoms from the lower airways, and symptoms of smell impairment, and more often had nasal polyps and hyperaemia of the nasal mucosa. They also had higher levels of MPO in NAL (especially dairy farmers and pig farmers), and a tendency to more swollen nasal mucosa and lower olfactory threshold (especially grain farmers). CONCLUSIONS: The farmers had more pathological findings in their nasal mucosa, possibly indicating effects of allergens and irritants in their work environment. More studies are needed to evaluate work environment factors causing these pathological findings in farmers.

Adult↗
PubMed2001

Absence of proinflammatory cytokine gene expression in nasal biopsies from wood surface-coating industry workers.

Symptoms of nasal, pharyngeal and ocular discomfort have been reported among workers in the wood surface-coating industry. Symptoms were reported more often by workers using ultraviolet radiation-curable acrylate coatings (UV coatings), which contain potential chemical sensitizers, than by those using acid-curing coatings. Furthermore, increased levels of eosinophil cationic protein (ECP) and albumin, but not tryptase, in nasal lavage from workers exposed to UV coatings have been observed. To further examine whether air contaminants present in the UV-coating industry are causing the observed increase in symptoms, the inflammatory process in the nasal mucosa of workers exposed to UV coatings was investigated. Clinical and biochemical endpoints were selected to distinguish between specific and non-specific hypersensitivity and to test the hypothesis that the symptoms were consistent with Type IV hypersensitivity. The nasal lavage and nasal biopsy were performed under local anesthetic at the workplace during working hours after a minimum of 2 h of work in both the exposed and control groups. Albumin and ECP, and the cytokines tumor necrosis factor-alpha (TNF-alpha) and interleukin-8 (IL-8), were used as inflammatory markers. A multi-probe ribonuclease protection assay was used to attempt to detect cytokine variation in human nasal biopsies. The cytokine genes analyzed were TNF-alpha, GM-CSF, interferon-gamma, IL-2, IL-4 and IL-5. L32 and GAPDH were used as control genes for mRNA expression levels. Mucosal inflammation symptoms correlated with increased levels of albumin, but not with increased levels of ECP, secreted proinflammatory cytokines or cytokine gene mRNA expression. We conclude that the symptoms are non-specific and do not correlate with occupational exposure to UV coatings under the conditions of this investigation.

Albumins↗
PubMed2000

[Nasal polyposis--of interest to several specialties. Improved diagnosis and new therapeutic possibilities].

Nasal polyposis, a disease seen mainly in humans and dominated in most cases by an eosinophilic inflammation of unknown etiology, has been an enigma for a few thousand years. Polyps are, however, overrepresented in patients with general airway inflammation as seen in asthma and idiopathic rhinitis, and in patients with infective nasal disease of chronic origin as seen in cystic fibrosis, immune deficiencies and dental sinusitis. Due to the eosinophilic nature of the inflammation, polyps are on the whole sensitive to local steroid treatment with spray or drops. Surgery is indicated when the polyps are solitary or when medical treatment fails.

Administration, Intranasal↗
PubMed2000

Dose-related efficacy and tolerability of fluticasone propionate nasal drops 400 microg once daily and twice daily in the treatment of bilateral nasal polyposis: a placebo-controlled randomized study in adult patients.

BACKGROUND: Topical corticosteroids are the accepted medical adjunct to surgery in patients suffering from nasal polyposis. Fluticasone propionate (FP) is a potent, topically active corticosteroid which has been formulated as nasal drops specifically for the treatment of polyposis. OBJECTIVES: To evaluate dose-related efficacy and tolerability of FP nasal drops (FPND) in the treatment of mild to moderate bilateral polyposis; in a double-blind, placebo-controlled, multicentre international study. METHODS: Adult patients (n = 142) with bilateral nasal polyps were randomized to receive either FPND 400 microg once daily (o.d.), FPND 400 microg twice daily (b.i.d.) or placebo for 12 weeks. The majority then entered a further 12 week open period during which all patients received FPND 400 microg o.d. The primary efficacy endpoint was the physicians' visual assessment of polyp size. Secondary clinical endpoints were nasal blockage and overall rhinitis (0-3 scores), peak nasal inspiratory flow (PNIF), olfactory function tests, and requirement for polypectomy. The patients also kept twice daily records of symptom scores, peak nasal inspiratory flow (PNIF) and use of rescue medication. RESULTS: At the end of the 12 week randomized treatment period, polyp size was reduced significantly by FPND 400 microg b.i.d. as compared with placebo (P = 0.006). Clinical assessments of nasal blockage and overall rhinitis showed significant improvements at several stages of treatment with both doses of FPND. Clinic PNIF was also improved significantly by both doses of FPND in comparison with placebo, and FPND 400 microg b.i.d. was significantly more effective than 400 microg o.d. (P = 0.045). Patient diary card scores supported the clinical assessments. Two patients on placebo required polypectomy and all treatments were well tolerated with a similar incidence of adverse events. CONCLUSION: FPND 400 microg once or twice daily is an effective and well-tolerated treatment for bilateral nasal polyposis.

Administration, Intranasal↗
PubMed2000

Nasal histamine reactivity in woodwork teachers.

Woodworkers exposed to wood dust have an increased frequency of rhinitis. We have previously reported such rhinitis in woodwork teachers. To test whether their nasal complaints are related to nasal hyper-reactivity, we selected 14 woodwork teachers with work-related rhinitis and 14 healthy and non-allergic control persons for nasal histamine challenge using symptom scores (0-3 scale) and acoustic rhinometry for effect evaluation. Intranasal saline followed by doubled concentrations of histamine phosphate (from 0.062 to 16 mg/ml) was given at five-minute intervals. There was no significant difference between the groups regarding symptom scores or acoustic rhinometry during the challenge. The results indicate that nasal hyperreactivity is not a prominent factor in wood-dust-related rhinitis. Other mechanisms probably prompt the nasal complaints.

Adult↗
PubMed2000

Fewer problems with dry nasal mucous membranes following local use of sesame oil.

Many people experience problems with a dry nasal mucous membrane, often without wondering why. Their noses itch and burn and dried mucus collects there. These problems are exacerbated during the winter, in air-conditioned environments and after nasal irradiation. Twenty patients experiencing problems with dryness of the nose were selected from outpatient clinics, together with twenty patients who had previously undergone nasal irradiation. During the first five days no treatment was administered. For the following twenty days the patients sprayed sesame oil into each nostril three times a day. For the last five days no treatment was given. When both groups received treatment and sprayed sesame oil (Nozoil) in their noses, the nasal problems decreased significantly. The greatest effect is exerted on dryness. The side effects from using this oil are few in number and mild.

Administration, Intranasal↗
PubMed1999

Harmful singlet oxygen can be helpful.

Highly reactive harmful singlet oxygen O2(1delta(g)) can be helpful while relaxing to its triplet ground state O2(3sigma(g)-). The energy emitted during this relaxation from the excited energy state is discernable at 634 nm. We report here on the effect of this energy as photon illumination and as energy transfer in air on the production of reactive oxygen species (ROS) by human monocytes, measured as isoluminol-enhanced chemiluminescence. We demonstrate up to 60% decrease in the secretion of ROS after 2-min illumination of the monocytes stimulated with phorbol myristate acetate (PMA). The results provide in vitro documentation of the utility of singlet oxygen energy in modifying cellular behaviour.

Catalase↗
PubMed1999

Clinical performance of fluticasone propionate nasal drops.

The efficacy and safety of fluticasone propionate (FP) nasal drops were investigated in two multicentre, randomized, placebo-controlled trials. Patients received FP 400 microg once or twice daily for 12 weeks and then FP 400 microg once daily for a further 12 weeks. FP 400 microg significantly reduced polyp size and improved peak nasal inspiratory flow, rhinitis symptoms and sense of smell when administered twice daily. Significant reductions in polyp size were not achieved with once daily administration, but clinical benefits were observed for peak nasal inspiratory flow. Both dosing regimens were well tolerated, with an overall incidence of adverse events which was similar to placebo.

Administration, Intranasal↗
PubMed1999

Pharmacokinetics and pharmacodynamics of melagatran, a novel synthetic LMW thrombin inhibitor, in patients with acute DVT.

Forty-eight patients with acute proximal deep vein thrombosis (DVT) were randomised to intravenous infusions for 4 to 6 days with melagatran, a novel synthetic low molecular weight thrombin inhibitor, or unfractionated heparin adjusted by the activated partial thromboplastin time (APTT). The aim of the study was to investigate the pharmacokinetics, pharmacodynamics and the safety of melagatran therapy at three different doses. Steady-state plasma concentrations were rapidly achieved and maintained throughout the infusion period. The mean plasma concentrations in the low, medium and high dose groups were 0.17, 0.31 and 0.53 micromol/l, respectively. The prolongation of APTT was stable during the melagatran infusions and correlated to the plasma concentration. Phlebographically verified regression of thrombus size measured as decrease in Marder score was seen after 4 to 6 days in 8 of 12 patients, 6 of 12 patients and 5 of 11 patients in the low, medium and high dose groups of melagatran and in 5 of the heparin-treated patients. In the low dose group with melagatran, thrombus extension was seen in one patient. At the dose levels studied, melagatran was well tolerated with no clinically significant bleeding problems, suggesting that melagatran could safely be given to patients suffering from DVT.

Adolescent↗
PubMed1999

Long-term clinical follow-up in 265 patients with deep venous thrombosis initially treated with either unfractionated heparin or dalteparin: a retrospective analysis.

The primary objective of this retrospective study was to describe the frequency of a post-thrombotic syndrome in 265 patients previously treated for deep venous thrombosis (DVT). The secondary objectives were to document the frequency of recurrent venous thromboembolism (VTE) and mortality, especially from malignant disease. The patients were evaluated 5-14 years after inclusion in three randomized trials comparing continuous intravenous (i.v.) infusion of unfractionated heparin (UFH) (n = 85) with a low molecular weight heparin (LMWH), dalteparin (n = 180). The median post-thrombotic score at follow-up was 2 (range 0-8). In a multiple step-wise regression analysis the postthrombotic score was significantly higher among patients with initial proximal DVT (p = 0.0001) as compared with those who had distal DVT. A recurrent venous thromboembolic event was diagnosed in 29.4% of the patients treated with dalteparin and in 23.5% of the patients treated with UFH (ns). A secondary risk factor for venous thromboembolism and a longer duration of treatment with oral anticoagulants (OAC) were significantly associated with a lower risk for recurrent VTE, whereas malignant disease diagnosed during follow-up was associated with a higher risk. During follow-up a total of 40.7% of patients had died. No difference in total mortality or mortality from malignant disease was demonstrated between the two drugs. In conclusion, a severe post-thrombotic syndrome occured relatively infrequent. considering the long observation period. Proximal DVT was significantly associated with a more severe post-thrombotic syndrome. After 14 years follow-up, no significant differences were observed in overall mortality, mortality from malignant disease or recurrent VTE between UFH- and dalteparin-treated patients. Malignant disease was a risk factor for recurrent VTE, the presence of a secondary risk factor and a longer duration of treatment with OAC decreased the risk for recurrent VTE.

Anticoagulants↗
PubMed1998

Biomarkers of nasal inflammation in wood-surface coating industry workers.

Upper airway symptoms in workers employed in the manufacture of wood products using ultraviolet radiation curing or acid curing of surface coating have been reported. In this study, workers were divided into groups according to exposure: (1) UV-surface coating line, (2) acid curing surface coating line, (3) finishing processes of UV-cured acrylate coated products, (4) finishing processes of of both UV- and acid cured coated wood products, and (5) control group. The workers were examined with nasal lavage in order to investigate inflammatory signs (ECP, tryptase, albumin and microscopy with cell differential counting). UV-line workers and finishers had significantly increased levels of ECP in nasal lavage. There was a positive correlation between exposure time and ECP and albumin levels. Workers with general nasal complaints and atopics had increased levels of ECP. In this study there were findings indicating an inflammatory process in the nasal mucosa in workers exposed to UV radiation curing multifunctional acrylate coatings. The findings indicate an unspecific inflammation and, therefore, a correlation between occupational exposure to acrylate coatings and nasal inflammation seems probable.

Acrylates↗