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Biomedical subjects

B Andréasson

Publications and source records attributed to B Andréasson.

At least 19 recordsLinked to original sources
PubMed2006

Hydroxyurea therapy increases plasma erythropoietin in patients with essential thrombocythaemia or polycythaemia vera.

The determination of serum/plasma erythropoietin (EPO) concentration has gained widespread use in the diagnosis of polycythaemia vera (PV). A reduced EPO concentration in a newly diagnosed essential thrombocythaemia (ET) seems to be a risk factor for thromboembolic events. In this study plasma EPO concentration was determined before and after initiated hydroxyurea (HU) therapy, 14 patients with PV or ET were included. After 1 month on HU therapy 11 of 14 patients had increased their EPO concentration compared with prior to medication. The plasma EPO was increased in all, except one patient, after 4 months HU therapy. If EPO is incorporated in the diagnostic or prognostic procedures it should be determined before myelosuppressive therapy is initiated.

Aged↗
PubMed2004

Oxygen affinity is decreased in patients with polycythaemia vera and essential thrombocythaemia.

The plasma erythropoietin (EPO) concentration is subnormal in the vast majority of all patients at the time of diagnosis of polycythaemia vera (PV) and in 33-50% of patients with essential thrombocythaemia (ET). At equivalent haemoglobin concentrations patients with PV and a substantial number of ET patients have subnormal EPO concentrations compared with those of healthy subjects. A possible explanation could be altered haemoglobin (Hb) oxygen affinity. Plasma EPO concentration and the oxygen pressure at 50% Hb saturation (p50) were measured in 29 patients with PV, 23 patients with ET and 34 healthy controls. There was no significant correlation between p50 and plasma EPO concentration. However, the mean p50 for PV patients exceeded the mean for healthy controls (p = 0.004). Furthermore, the mean p50 for ET patients significantly (p = 0.012) exceeded the mean for controls but there was no significant difference in p50 between patients with PV and ET. It could be hypothesized that the lower oxygen affinity to Hb in PV and ET patients partly explains the decreased EPO production.

Adult↗
PubMed2004

Trends in the incidence of chronic Philadelphia chromosome negative (Ph-) myeloproliferative disorders in the city of Göteborg, Sweden, during 1983-99.

OBJECTIVE: In the literature the incidence rates for the chronic Philadelphia chromosome negative (Ph-) myeloproliferative disorders (MPD) are known to vary extensively; only a few studies have, however, been concerned with incidence trends over time. Therefore, the aim of the present work was to investigate possible trends as regards incidence rates over time for Ph-MPD. DESIGN: Herein, we carried out a retrospective population-based survey on the incidence of polycythaemia vera (PV), essential thrombocythaemia (ET) and chronic idiopathic myelofibrosis (IMF), in the city of Göteborg (Sweden), covering the years 1983-99. RESULTS: The study comprised 416 patients with Ph-MPD. There were 205 patients with PV, 153 patients with ET, 34 with IMF and 24 with unclassified MPD. The annual incidence for PV was 1.97 per 10(5) inhabitants; the corresponding figures for ET and IMF were 1.55 per 10(5) and 0.30 per 10(5) inhabitants, respectively. There was a significant increase in the annual incidence rate for ET (P = 0.008); this increase was significant for male subjects (P = 0.015) but did not reach significance for females (P = 0.118). No such increase over time was recorded as regards PV and IMF. CONCLUSIONS: The increasing annual incidence rate for ET is most possibly explained by the more frequent use of automated platelet counts whenever a patient consults a doctor. Thereby, an increasing number of patients with overt thrombocytosis of unknown origin are discovered and will be referred to specialists within the field of haematology for a correct diagnosis.

Adult↗
PubMed2002

On the diagnosis of polycythaemia vera as assessed in the health and medical care in the Västra Götaland region, Sweden.

OBJECTIVES: The aim was to assess how the diagnosis of polycythaemia vera (PV) was established and to study to which extent the classic Polycythemia Vera Study Group (PVSG) criteria and the revised criteria for the diagnosis of PV as proposed by Pearson and Messinezy in 1996 (PM criteria) were fulfilled when the diagnosis of PV was made. DESIGN AND SETTING: A questionnaire was sent to physicians in charge of haematological patients at the departments of medicine in 12 hospitals in the Health and Medical Care in the Västra Götaland Region (VGR), Sweden, with a population of 1.5 million inhabitants; they were asked to provide reports as regards all patients with an unequivocal diagnosis of PV during a 5-year period from January 1994 to December 1998. SUBJECTS: Full reports were obtained from six hospitals, which serve about 1.1 million inhabitants. The results from a total of 129 PV patients, 62 from two university hospitals (UHs) and 67 from four county hospitals (CHs), were the subject of the present analysis. Results. It was shown that measurement of the red cell mass (RCM) had been carried out in 61 of 62 (98%) patients in UHs compared with 24 of 67 (36%) patients at CHs (P < 0.01). By using ultrasound imaging and/or scintigraphy the spleen size had been determined in 55 of 62 (89%) patients at UHs and in 24 of 67 (36%) patients at CHs (P < 0.01). At the UHs, arterial oxygen saturation had been measured in 32 of 62 (52%) patients; the corresponding figure for the CH patients was 22 of 67 (33%). Plasma or serum erythropoietin (EPO) concentrations had been measured in 44 of 62 (71%) of PV patients at UHs and in 31 of 67 (46%) of patients at CHs; in all these cases the EPO concentrations were subnormal or not measurable. CONCLUSIONS: At the UHs only 37% of the PV patients fulfilled the PVSG criteria for the diagnosis of PV whereas the corresponding figure for CHs was 4% (P < 0.01). The adherence to PM criteria was, however, 71% at UHs compared with 16% at CHs (P < 0.01).

Adult↗
PubMed2001

The relation between plasma thrombopoietin and erythropoietin concentrations in polycythaemia vera and essential thrombocythaemia.

Plasma thrombopoietin (TPO) was measured, by immunoenzymometric assay, in 39 patients with polycythaemia vera (PV), 33 patients with essential thrombocythaemia (ET) and 10 healthy volunteers. The mean TPO concentration was significantly higher in ET patients than in PV patients (p=0.04) and normals (p<0.001). The 6 untreated ET patients had a significantly lower mean TPO concentration compared to the 27 ET patients who were on myelosuppressive regimens (p=0.01). The mean plasma TPO for the 5 PV patients treated with phlebotomy only did not differ significantly from the corresponding mean for the 34 PV patients treated with myelosuppressive agents. Concomitantly, plasma EPO was measured in 25 of the PV patients and in 30 of the ET patients by an immunoradiometric assay with normal reference interval in adults 3.7-16 IU/L. In the 14 PV patients with EPO <3.7 IU/L mean plasma TPO did not differ significantly from the mean for the 11 PV patients with EPO >or=3.7 IU/L; neither of these two groups had plasma TPO concentrations significantly different from the mean for the control subjects. The 7 ET patients with subnormal plasma EPO had significantly lower mean plasma TPO compared to the ET patients with normal and high plasma EPO concentrations (p=0.03 and p=0.02, respectively). Also, the 16 ET patients with normal plasma EPO had significantly lower plasma TPO compared to the 8 patients with high plasma EPO (p=0.04). The mean plasma TPO for each of these three groups of ET patients was significantly higher than the corresponding mean for the controls (p<0.001 for each group). The results of the present study indicate that a relationship between plasma EPO and TPO concentrations may exist and that myelosuppressive treatment affects the TPO concentration in ET but not in PV patients.

Adult↗
PubMed2000

Hydroxyurea treatment reduces haematopoietic progenitor growth and CD34 positive cells in polycythaemia vera and essential thrombocythaemia.

The aim of the present work was to investigate the effect of hydroxyurea (HU) treatment on haematopoietic progenitors and CD34 positive (CD34+) cells in patients with polycythaemia vera (PV) and essential thrombocythaemia (ET). Of the PV patients were 10 treated with phlebotomy only and 10 were on HU therapy. Seven ET patients were untreated and 10 received HU. In each subject peripheral blood was obtained for in vitro colony growth, determination of CD34+ cells and plasma erythropoietin (EPO) concentration. The mean number of EPO independent erythroid colonies (EEC) was higher in the group of PV patients on phlebotomy therapy compared to the PV patients treated with HU (74.4 and 8.0 colonies/10(5) cells, respectively) but the difference did not reach statistical significance. The corresponding means for the untreated ET patients and ET patients treated with HU were 13.0 and 1.3 colonies/10(5) cells, respectively, this difference being statistically significant (p = 0.012). The mean EEC for combined groups of PV and ET without myelosuppressive treatment were compared with the results for PV and ET patients on HU therapy; this difference was statistically significant (p = 0.014). The same pattern was observed for total erythroid growth with EPO. The relationship between the concentration of CD34+ cells and total EEC in peripheral blood was statistically significant for both PV (p<0.005) and ET (p<0.01). This finding supports the hypothesis that the level of CD34+ cells in peripheral blood could be used as a proliferation marker in these two myeloproliferative entities. No relationship between plasma EPO and EEC was present. It therefore appears that the reported differences in plasma/serum EPO concentrations between PV patients on phlebotomy treatment compared to patients on myelosuppressive treatment are not likely to be found at the production site for erythrocytes.

Adult↗
PubMed2000

Plasma erythropoietin concentrations in polycythaemia vera with special reference to myelosuppressive therapy.

In 80 patients with polycythaemia vera (PV) a total of 108 venous blood samples were obtained and analysed for EDTA-plasma erythropoietin (EPO) concentration. At the time of study 21 of the PV patients were newly diagnosed and had prior to blood sampling neither received phlebotomy treatment nor therapy with myelosuppressive agents; these subjects had a mean plasma EPO concentration of 0.5+/-0.9 IU/L. Thirty-seven patients treated with phlebotomy only had a mean plasma EPO concentration of 2.5+/-2.9 IU/L. The mean plasma EPO concentrations for 26 patients treated with hydroxyurea, 13 patients treated with radiophosphorous and 11 patients given a combination of myelosuppressive agents were 8.9+/-8.0, 10.9+/-12.6 and 7.2+/-7.4 IU/L, respectively. Untreated patients and patients on phlebotomy only had significantly lower values for plasma EPO than patients on therapy with myelosuppressive drugs. This finding persisted also after a correction for differences in haemoglobin levels had been introduced. Thereby, the present results would suggest a difference in the EPO feedback system in untreated and phlebotomised PV patients compared to PV patients treated with myelosuppressive agents.

Adult↗
PubMed2000

Plasma erythropoietin in essential thrombocythaemia: at diagnosis and in response to myelosuppressive treatment.

Sixty-five patients with essential thrombocythaemia (ET) on different treatment regimens were studied with regard to EDTA-plasma erythropoietin (EPO) concentrations. In accordance with other studies we found that close to 50% of the untreated ET patients had subnormal (<3.7 IU/L) plasma EPO. The mean plasma EPO concentration for untreated ET patients was significantly lower compared to patients treated with hydroxyurea (HU), radiophosphorous, alpha-interferon or combinations of myelosuppressive agents. This was also true after correction for differences in haemoglobin concentrations had been introduced. An increase in plasma EPO was recorded in all 20 ET patients in whom plasma EPO was registered before and after initiation of myelosuppressive therapy. At the time of diagnosis plasma EPO concentration was available in 31 of the ET patients. In 13 of them the plasma EPO was subnormal whereas the EPO concentrations were > or =3.7 IU/L in the remaining 18 subjects. It was demonstrated that the time to initiation of myelosuppressive treatment was significantly shorter for the former group of patients; they also had more vascular events (11 out of 13) than the group of patients with plasma EPO concentrations > or =3.7 IU/L (9 out of 18). It therefore appears that a subnormal plasma EPO in newly diagnosed ET might be a risk factor for the development of vascular complications.

Adult↗
PubMed1999

The measurement of venous haematocrit in patients with polycythaemia vera.

OBJECTIVE: In clinical practice, patients with polycythaemia vera (PV) are monitored by measurement of venous packed cell volume (PCV). However, whereas treatment recommendations are still based upon studies in which the results were obtained with the centrifuged microhaematocrit, currently in most instances automated blood cell counters are used to calculate PCV. In a group of patients with polycythaemia we therefore compared the results obtained by the microhaematocrit method with PCV calculated by haematology analysers. DESIGN: The study was carried out on a prospective basis. Duplicate venous blood samples were collected. The centrifuged microhaemotocrit was obtained by using an IEC Micro-MB Centrifuge. Depending on different routine methods used in the participating hospitals, the blood cell counter PCV was calculated using Coulter STKS, Bayer Technicon H2 or H3. SETTING: Patients were included from four Swedish university hospitals: Akademiska (Uppsala), Huddinge and Karolinska (Stockholm) and Sahlgrenska (Göteborg). SUBJECTS: Seventy-four patients with PV and 10 patients with secondary polycythaemia were included and a total of 150 duplicate blood samples were analysed from these subjects. RESULTS: In the 150 measurements the mean blood cell counter calculated PCV was 0.448 +/- 0.037; the mean for centrifuged microhaematocrit was 0.467 +/- 0. 037 and the difference between means was highly significant (P = 6.8 x 10-25). The means for centrifuged haematocrit and calculated PCV differed significantly in the groups of PV patients treated with phlebotomy only, hydroxyurea or radiophosphorous (P < 0.0001, respectively). In PV patients treated with alpha-interferon and in patients with secondary polycythaemia the difference in means did not reach statistical significance (P = 0.07 and P = 0.13, respectively). The groups of patients with MCV <80 fL and >/=80 fL both presented significant differences between means for calculated PCV and centrifuged haematocrit. CONCLUSIONS: If PV patients are monitored with blood cell counter calculated PCV it appears that the therapeutic goal should be to maintain the calculated PCV below 0.43, provided the local differences in calculated PCV and centrifuged haematocrit are of the same magnitude as in this study.

Aged↗
PubMed1998

Thoracoabdominal motion in newborns during ventilation delivered by endotracheal tube or nasal prongs.

Preterm infants have asynchronous thoracoabdominal motion (TAM) secondary to a highly compliant chest wall and different lung mechanics compared to term infants. We compared TAM during continuous positive airway pressure (CPAP) administered through an endotracheal tube (ETT-CPAP) or nasal prongs (nasal-CPAP), and during synchronized intermittent mandatory ventilation administered by nasal prongs (nasal-SIMV) in 14 preterm newborn infants. Asynchrony of TAM was quantified by measuring relative motion of chest wall and abdomen with strain gauges and calculating phase angles (theta). Phase angles were lower during nasal-SIMV compared to nasal-CPAP or ETT-CPAP (P < 0.05), and lower during nasal-CPAP compared to ETT-CPAP (P < 0.05). The reduced TAM asynchrony during nasal-SIMV and nasal-CPAP may be due to elimination of resistance of the ETT and/or effective stabilization of the chest wall. These data suggest that nasal-SIMV may be an effective mode of respiratory support for preterm infants requiring minimal ventilatory support.

Abdomen↗
PubMed1997

Increase of CD34 positive cells in polycythaemia vera.

The purpose of the present work was to evaluate the proliferative character of polycythaemia vera (PV). Therefore, in 15 patients with different stages of PV we assessed the level of CD34 positive (CD34+) cells in peripheral blood and bone marrow, erythroid colony growth of bone marrow cells and plasma erythropoietin (EPO). The mean concentration of CD34+ cells in blood was significantly increased in PV patients (9.0 +/- 11.2 x 10(3)/mL) compared to healthy controls (2.0 +/- 1.7 x 10(3)/mL). In aspirated bone marrow no such difference between PV and control subjects was present. Six patients with splenomegaly and/or requirement for chemotherapy had significantly higher mean blood levels of CD34+ cells compared to the remaining PV patients. All PV patients presented EPO independent erythroid colonies. Three PV patients with anaemia and long disease duration had high EPO levels.

Aged↗
PubMed1989

Potential of early chest roentgen examination in ventilator treated newborn infants to predict future lung function and disease.

The potentially of early chest X-ray to predict the risk of lung function abnormalities was studied prospectively in 40 preterm ventilator treated infants in a 8-10-year follow-up investigation. According to the findings at chest X-ray 3 to 10 days after completed ventilator treatment the infants were divided into 3 groups considered to represent increasing risk and severity of lung damage: 1) normal findings, 2) interstitial parenchymal abnormalities exclusively or 3) in combination with local or general hyperinflation. Lung function tests and chest x-ray were performed at the age of 8 to 10 years. A correlation was found between the findings at the early chest roentgen examination and the risk of abnormal lung function at the follow-up. Occurrence of focal or general hyperinflation or both were associated with a greater risk of airway obstruction. Infants with only interstitial abnormalities were, however, at a higher risk than those with normal chest examination to develop general hyperinflation and increased air way obstruction.

Bronchopulmonary Dysplasia↗
PubMed1989

Measurement of ventilation and respiratory mechanics during continuous positive airway pressure (CPAP) treatment in infants.

A new method has been evaluated for measuring ventilation and lung mechanics in spontaneously breathing infants by means of a face chamber. Airway flow is measured with a pneumotachograph inserted between the face chamber and a stable pressure source. Oesophageal pressure is measured via a water-filled oesophageal catheter. The method is suitable for use in conjunction with continuous positive airway pressure (CPAP) treatment in neonatal intensive care. A flat frequency response curve up to 15 Hz for the two measuring systems (i.e., airway flow and oesophageal pressure), and a time shift between the two respective signals of less than 2 msec are prerequisites for correct evaluation of respiratory mechanics. In preterm infants with chest distortion, the inhomogeneity of pleural pressure affects the significance of resistance and compliance values, as calculated from oesophageal pressure. Supra-diaphragmatic pressure variations reflect the resistive and elastic load on the diaphragm exerted by the lungs and thorax. Thus, oesophageal pressure is still useful in studies of respiratory mechanics in preterm infants.

Apnea↗
PubMed1989

Lung function eight years after neonatal ventilation.

Forty children who had had artificial ventilation during the neonatal period were studied at the age of 8-10 years with spirometry, the nitrogen washout test, bicycle exercise test, pulse oximetry, electrocardiogram, vectorcardiogram, and chest radiography. The median gestational age at birth was 29 weeks, and the median birth weight was 1310 g. Hyaline membrane disease was the indication for neonatal ventilation in 25 children. Bronchopulmonary dysplasia was diagnosed from radiographs in 11 infants (27%). Airway obstruction was observed in 10 of 11 children who had had bronchopulmonary dysplasia and in nine of 29 children who had not. After inhalation of terbutaline, the forced expiratory volume in one second (FEV1) was significantly increased. General hyperinflation was found in 16 of 17 children with abnormal chest radiographs (eight who had had bronchopulmonary dysplasia and nine who had not). Functional residual capacity was significantly higher in children with abnormal radiographs. Each child had a normal maximum working capacity and a normal electrocardiogram, and all but two had normal vectorcardiograms. Oxygen saturation at maximum work load decreased significantly in both groups of children. The risk of future respiratory problems calls for further follow up of lung function and chest radiography.

Electrocardiography↗
PubMed1988

Effects on respiration of CPAP immediately after extubation in the very preterm infant.

The effects of continuous positive airway pressure (CPAP) on pulmonary function during weaning from ventilator treatment were examined immediately after extubation in 17 very preterm infants, who had been ventilator-treated because of hyaline membrane disease (15 infants) and chronic pulmonary insufficiency of prematurity (two infants). Seven infants had bronchopulmonary dysplasia. Median birthweight was 920 g and median gestational age 26 completed weeks. The median duration of ventilator treatment was 10 days. Application of CPAP by means of a face chamber device after endotracheal extubation significantly lowered the frequency of apnea (P = 0.02) and enhanced oxygenation (P = 0.001). The respiratory mechanical indices derived from flow rate and juxta-diaphragmatic esophageal pressure measurements showed a reduced elastic (P = 0.03) and resistive (P = 0.02) load on the diaphragm. Even if the measured values do not accurately represent absolute resistances and compliances, the relative values of end-inspiratory and end-expiratory pressures differed significantly with and without CPAP (P = 0.001 and 0.002, respectively). We found CPAP applied via the face chamber technique immediately after extubation to be beneficial and to facilitate weaning from ventilator treatment in very preterm infants.

Female↗
PubMed1987

Long-term effects of physical exercise on working capacity and pulmonary function in cystic fibrosis.

Seven patients with cystic fibrosis aged 6 to 20 were enrolled for 30 months in a daily exercise program. After 12 months conventional chest physiotherapy was withdrawn. Patients with low initial Shwachman scores improved as regards maximal working capacity. Spirometric data and volume of trapped gas indicated opening of closed airways. We suggest that physical exercise in general should be the basis of pulmonary therapy in cystic fibrosis. Other forms of physiotherapy are advisable when hard physical exercise is not feasible.

Adolescent↗