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Biomedical subjects

B Wikström

Publications and source records attributed to B Wikström.

At least 19 recordsLinked to original sources
PubMed2004

Renal replacement therapy in Sweden.

OBJECTIVE: The Swedish Registry for Active Treatment of Uraemia (SRAU) was founded in 1991 with the objective of documenting demographic data on patients treated for end-stage renal disease (ESRD). The aim of this study was to describe the prevalence, incidence, comorbidity risk factors and survival of patients with ESRD who underwent dialysis treatment and/ or kidney transplantation in Sweden between 1991 and 2002. MATERIAL AND METHODS: All dialysis and transplant units (n = 65) presently report to the SRAU and almost all patients are reported and followed until death. RESULTS: The prevalence of patients on dialysis and transplantation, being approximately 750 per million population (PMP), has increased by 75% in 12 years. The recent annual rise is approximately 3% (200 patients). The incidence has been stable since 1997 at approximately 125 patients PMP. In 2002, there were 1113 new patients, the majority of whom were aged > or =65 years. Their original kidney disease was most often diabetic nephropathy (23.7%), with nephrosclerosis (19.0%) being the second most common disease. The total number of renal transplantations performed has decreased to some extent. The overall 5-year patient survival rate was 23.1% in patients on dialysis and 85.5% after kidney transplantation. The major cause of death was cardiovascular disease (48%) and an increasing frequency of malignancy after transplantation (26%) was noted. CONCLUSION: The prevalence of ESRD has nearly doubled since 1990 and the number of new patients being referred for dialysis has increased. These patients are becoming older, with a large proportion having non-renal complicating diseases. Survival after transplantation was excellent. The shortage of cadaveric donors in Sweden in recent years and increasing mortality from malignant disease after transplantation are issues of great concern.

Adolescent↗
PubMed2003

The Arctic Oscillation and incidence of acute myocardial infarction.

OBJECTIVES: To describe the relation between the Arctic Oscillation (AO) index and the incidence and mortality in acute myocardial infarction (AMI) in the northern, partly subarctic area of Sweden. DESIGN: Comparison of a time series of daily variations in the AO index and register data on the daily number of fatal and nonfatal AMIs. SETTING: The northernmost two Swedish counties, Norrbotten and Västerbotten. SUBJECTS: All inhabitants in the Norrbotten and Västerbotten counties were followed for the occurrence of an AMI between 1985 and 1999 within the framework of the WHO MONICA (multinational MONItoring of trends and determinants of CArdiovascular disease) Project. MAIN OUTCOME MEASURE: Fatal and nonfatal AMIs. RESULTS: There was a consistent positive relation between increasing AO index and an increase in AMI incidence and mortality. The maximum impact on AMI incidence of the AO came after a lag phase of 3 days. A one unit increase in AO index was associated with an increase in: the daily number of AMIs (+3.8%), the case fatality in AMI within 28 days (+5.1%), the number of nonfatal AMIs (+3.4%), and the number of sudden cardiac deaths (+8.3%). CONCLUSIONS: An AO index increase, bringing warmer weather over Scandinavia, was associated with an increase in the incidence and mortality in AMI in northern Sweden.

Arctic Regions↗
PubMed2002

Exploring sex differences in case fatality in acute myocardial infarction or coronary death events in the northern Sweden MONICA Project.

OBJECTIVES: To investigate sex differences in reaching diagnosis, medical management and case fatality (CF) in acute myocardial infarction (AMI) in the population aged 35-64 years in northern Sweden. METHODS: Within the framework of the World Health Organization Multinational Monitoring of Trends and Determinants in Cardiovascular Diseases (MONICA) Project, definite AMI was monitored in people aged 35-64 years from 1989 through 1995 (target population 510 000 in 1991). SETTING: In a population based coronary register, all coronary events were recorded in nine hospitals in 1989-95. RESULTS: The number of events included in the definite coronary myocardial infarction register was 2483 men and 669 women. On admission, a higher proportion of men with definite AMI had chest pain or ECG changes typical for AMI (P < 0.0001). Disagreement between clinical diagnosis and classification by MONICA criteria occurred more often in women (P=0.008). A significantly higher proportion of men was admitted in the coronary care unit and they were significantly more often treated with thrombolytics, nitroglycerine, beta-blockers, or antiplatelet agents. Women received significantly more diuretics, inotropics or calcium antagonists. Diabetes, conferring a worse prognosis, was more common in women (20 vs. 15%; P=0.003). Prehospital CF was significantly higher in men (24.1 vs. 18.3%; P=0.005), but in patients treated in hospital, the CF was significantly lower in men (12.7 vs. 21.2%; P < 0.001). Total CF was equal in men and women. CONCLUSIONS: Several factors contributing to the excess in-hospital CF in women were identified, including greater problems in diagnosis of AMI in women which may be one of the reasons for less intensive treatment in women. Differences in co-morbidity, most notably diabetes and medical treatment between men and women with acute AMI may also have played a part.

Adult↗
PubMed2001

Fluid balance in patients with chronic renal failure assessed with N-terminal proatrial natriuretic peptide, atrial natriuretic peptide and ultrasonography.

The N-terminal proatrial natriuretic peptide (proANP) has become an important parameter for assessing the prognosis of patients with cardiac disease. Its use for evaluating the hydration status in patients with chronic renal failure, however, is still under investigation. The present study comprised 12 haemodialysis (HD) and 17 pre-dialysis patients. In the HD patients, the inferior vena cava diameter during quiet expiration (IVCe) was estimated by ultrasonography and plasma concentrations of N-terminal proANP, atrial natriuretic peptide (ANP) and cyclic guanosine monophosphate (cGMP) were measured before and 4 h after termination of HD. In the pre-dialysis patients venous blood samples were taken during rest to measure plasma N-terminal proANP and ANP and serum creatinine. Normal values for N-terminal proANP and ANP were obtained from 18 healthy volunteers. The plasma concentrations of N-terminal proANP and ANP in healthy volunteers were 328 +/- 92 and 11.4.0 +/- 3.1 pM L-1, respectively. In pre-dialysis patients, serum creatinine ranged from 110 to 447 microM L-1 and was significantly correlated to plasma N-terminal proANP (r = 0.60, P < 0.05) but not to ANP. This may indicate that N-terminal proANP is more dependent on renal function for its clearance than ANP, which is probably cleared by extrarenal mechanisms as well. In HD patients, IVCe was significantly correlated to the three hormones before HD, most strongly to N-terminal proANP. After dialysis, IVCe was significantly correlated to ANP and cGMP but was not correlated to N-terminal proANP. This may suggest that proANP takes a longer time than other hormones to reflect changes in intravascular volume. In conclusion, N-terminal proANP is a hormone closely related to degree of renal function. Furthermore, it is a sensitive marker reflecting the interdialytic hydration status in HD patients, as indicated by its high correlation to IVCe, a standard method which is used frequently nowadays to assess the body hydration. However N-terminal proANP could not reflect the acute changes in fluid volume induced by HD, probably because it is slowly metabolized.

Adult↗
PubMed2000

Growth parameters in the epiphyseal cartilage of brachymorphic (bm/bm) mice.

We studied kinetics in the epiphyseal cartilage of the brachymorphic (bm/bm) mouse, combining morphometry and labeling with halogenated nucleotides. The defective synthesis of the sulfate donor PAPS in these homozygous mutants is evident in tissues with a large production of glycosaminoglycans; these compounds become undersulfated. Compared with their heterozygous siblings, the longitudinal growth of the mutant mice was reduced by two-thirds. This was mainly associated with (1) reduced height of the proliferating zone, (2) a substantial number of G0 cells in this zone, and (3) reduced hypertrophy which, in turn, may be related to premature mineralization and prevention of normal expansion of cells. No significant effects on cell-cycle parameters were detected, such as S-phase time or cell-cycle time, and the rate at which each cell increased the matrix volume seemed normal. An effect on matrix mineralization may be related to known changes in the structure of matrix PGs, whereas the effect on proliferation may be related to other factors. Candidates for such other effects of undersulfation are the cell surface PGs, which are important for binding of growth factors.

Animals↗
PubMed1999

Effect of normalization of hematocrit on brain circulation and metabolism in hemodialysis patients.

Full correction of anemia with recombinant human erythropoietin (rhEPO) has been reported to reduce the risk of cardiovascular morbidity and mortality and improve the quality of life in hemodialysis (HD) patients. Effects of normalization of hematocrit on cerebral blood flow and oxygen metabolism were investigated by positron emission tomography. Regional cerebral blood flow (rCBF), cerebral blood volume (rCBV), oxygen extraction ratio (rOER), and metabolic rate for oxygen (rCMRO2) were measured in seven HD patients before and after correction of anemia and compared with those in six healthy control subjects. In addition, blood rheology before and on rhEPO therapy was measured in HD patients, which included blood viscosity, plasma viscosity, erythrocyte fluidity, and erythrocyte aggregability. The results showed that plasma viscosity was high (1.51+/-0.19 mPa x s) and erythrocyte fluidity was low (85.8+/-4.8 Pa(-1) x s(-1)), while whole blood viscosity was within the normal range (3.72+/-0.38 mPa x s) before rhEPO therapy. After treatment, the hematocrit rose significantly from 29.3+/-3.3 to 42.4+/-2.2% (P<0.001), accompanied by a significant increase in the whole blood viscosity to 4.57+/-0.16 mPa x s, nonsignificant decrease in erythrocyte fluidity to 79.9+/-7.4 mPa(-1) x s(-1) and nonsignificant change in plasma viscosity (1.46+/-1.3 mPa x s). Positron emission tomography measurements revealed that by normalization of hematocrit, rCBF significantly decreased from 65+/-11 to 48+/-12 ml/min per 100 cm3 (P<0.05). However, arterial oxygen content (caO2) significantly increased from 5.7+/-0.7 to 8.0+/-0.4 mmol/L (P<0.0001), rOER of the hemispheres significantly increased from 44+/-3 to 51+/-6% (P<0.05) and became significantly higher than healthy control subjects (P<0.05). In addition, rCBV significantly increased from 3.5+/-0.5 to 4.6+/-0.6 ml/100 cc brain tissue. The results showed that oxygen supply to the brain tissue increased with normalization of hematocrit, but it was accompanied by increased oxygen extraction in the brain tissue. This may be assumed to be related to the decrease of erythrocyte velocity in the cerebral capillaries as a result of the decreased blood deformability and the increased plasma viscosity.

Aged↗
PubMed1999

Plasma exchange or immunoadsorption in patients with rapidly progressive crescentic glomerulonephritis. A Swedish multi-center study.

A therapeutic removal of antibodies may be achieved by immunoadsorption (IA) or by plasma exchange (PE). The aim of this prospective randomised study was to compare the efficacy of these different techniques with regard to treatment of patients with rapidly progressive glomerulonephritis (RPG) having at least 50% crescents. Forty-four patients with a RPG were included for treatment either by IA or PE (with albumin as substitution for removed plasma). All patients were additionally treated with immunosuppression. A median of 6 sessions of PEs were performed in 23 patients compared with 6 IAs in 21 patients. Goodpasture's syndrome (GP) was present in 6 patients (PE 3, IA 3). All of them started and ended in dialysis, two died. Among the remaining 38 patients (26 men, 12 women) 87% had antibodies to ANCA. Creatinine clearance for PE versus IA were at a median at start 17.1 and 19.8 ml/min, and at 6 months 49 and 49 ml/min, respectively. At 6 months 7 of 10 patients did not need dialysis (remaining: IA 0/5 and PE 2/5, n.s.). The extent of improvement did not differ between the groups. Three patients died during the observation period of 6 months (IA 2; PE 1, on HD). Although no difference was found between the IA or the PE group this study shows that the protocol used was associated with an improved renal function in most patients (except for Goodpasture's syndrome) whereas 70% of them could leave the dialysis program.

Adult↗
PubMed1998

Identification of complement activators and elucidation of the fate of complement activation products during extracorporeal plasma purification therapy.

It has been known for many years that the complement system is activated during extracorporeal plasma purification (ECCP) therapy. In a previous study, we showed that high concentrations of complement activation products (CAPs) are returned to the patient during immunoadsorption treatment. In the present study, we investigated the question of where complement activation takes place with different forms of ECPP equipments as well as the fate of the CAPs. Eleven patients (8 men and 3 women), mean age 52 +/- 18 years, were included in the study. They were treated either with plasmapheresis (PP), immunoadsorption, bilirubin adsorption, or low density lipoprotein (LDL) apheresis. It was found that during all ECPP treatments and after the plasma separation filter, the plasma concentrations of CAPs were increased, and that high concentrations of CAPs were returned to the patients, except with PP. The plasma levels of individual CAPs varied between different types of ECPP. These variations were due to several factors: (1) complement activation (CA) on the plasma separator and a secondary device, e.g., column or membrane; (2) adsorption of specific CAPs to separation columns; and (3) reduction of CAPs due to separation and waste. Since CAPs have inflammatory and immunological effects, it is possible that high serum concentration of CAPs in the treated patients may influence the clinical outcome of the treatment. In conclusion, complement activation is a fact that should not be ignored during performance of any form of an ECPP. It is the plasma separator that plays a key role in the process of complement activation. Different ECPP treatments may have different effects regarding the levels of individual CAPs.

Adult↗
PubMed1998

Kinetic studies on epiphyseal growth cartilage in the normal mouse.

The synthesis of DNA was studied in the proximal tibial growth plate of 25-day-old healthy NMRI mice by using the thymidine analog bromodeoxyuridine (BrdUrd), which is incorporated into cells in the S-phase. Such cells were found only in the upper three fifths of the morphologically defined proliferating zone. This zone was therefore subdivided into a functional proliferating zone (the S-phase zone) where most, if not all, chondrocytes proliferate, and a remaining maturation zone. The BrdUrd containing immunoreactive cells could then be followed at different intervals and they were found at the chondro-osseous junction after only 36 h. By using double-labeling with BrdUrd and iododeoxyuridine (IdUrd) the duration of cell cycle components could be estimated; that is, the time for DNA synthesis (S-phase), second gap and mitosis (G2 + M-phase), and remaining first gap (G1). We determined an S-phase time of 7.1 h and an average cell-cycle duration of 36 h. The G2 + M-phase was estimated as 3.5-4 h, leaving an average G1-phase time of 25 h, which probably varies considerably between chondrocytes. By combining these data with morphometrical data regarding distances between cells, we calculated a total growth rate of 9.0 microm/h. Of this rate, 80% was entirely related to the process of hypertrophy--that is, longitudinal expansion without any corresponding increase in cell number--and 75 % was the result of processes outside the S-phase zone. Five percent of the growth was due to the expansion of cell distances within the S-phase zone. In this way longitudinal expansion can be studied at different levels in the growth plate and the data permit calculation of changes in volumes of the extracellular matrix. The largest increases in matrix volume occurred in the hypertrophic zone. These data may serve as a basis for further studies on matrix turnover in relation to growth.

Animals↗
PubMed1998

The value of different detection methods of Helicobacter pylori during treatment.

It has been suggested that profound acid inhibition by proton pump inhibitors affects the accuracy of H. pylori detection. This report aims to evaluate H. pylori status during treatment with four different invasive detection methods and to investigate if histopathological alterations during treatment can be used as an early marker for H. pylori eradication. Twenty-eight H. pylori-positive patients were studied randomized into two treatment groups: 14 patients received omeprazole, 20 mg plus amoxicillin 1,000 mg b.i.d (OA), and 14 patients received omeprazole, 20 mg and placebo b.i.d (OP) for 14 days. Biopsies from antrum and corpus of the stomach were collected on days 0, 10 and 42. H. pylori status was based on rapid urease test, cultivation, histology, and polymerase chain reaction (PCR). The biopsies were also graded according to the Sidney classification. In the OP and the OA group, 17% (2/12) and 92% (12/13) of the patients were H. pylori negative when tested during treatment (day 10). Four weeks after treatment none of the patients (0%) in the OP group and 61% (8/13) in the OA group had their H. pylori infection eradicated. PCR was up to 34% more sensitive than the other tests to detect H. pylori during treatment. There was a decrease in histological inflammation and activity in the antrum already during treatment in the OA group, but the decrease did not discriminate for successful treatment. During treatment with omeprazole alone or in combination with amoxicillin, H. pylori detection is impaired regardless of the detection method used. However, PCR appears to be more sensitive than other tests. Early changes in the histological appearance of the gastric mucosa do not predict H. pylori treatment outcome.

Adult↗
PubMed1998

Prolonged and profound acid inhibition is crucial in Helicobacter pylori treatment with a proton pump inhibitor combined with amoxicillin.

BACKGROUND: The aim was to investigate whether intragastric pH, meal-stimulated gastrin release, or demographic factors predict the outcome of Helicobacter pylori treatment. METHODS: Thirty-six patients with H. pylori infection were investigated with 24-h intragastric pH registration and meal-stimulated gastrin release before and during treatment with 20 mg omeprazole twice daily and 750 mg amoxicillin twice daily for 14 days. The influence of age, sex, smoking, ethnic origin, pH, and gastrin on treatment outcome were analysed with logistic regression. RESULTS: Eradication of H. pylori was achieved in 18 of 34 (53%) patients. The univariate analysis showed that age, ethnic origin, more than 84.2% of the time with pH above 4, and continuous periods longer than 156 min with intragastric pH above 6 were significantly associated with successful treatment of H. pylori. In the multivariate analysis only the two pH variables were found to be independent factors for predicting treatment outcome. CONCLUSION: The outcome of H. pylori treatment with omeprazole and amoxicillin may depend on several factors, such as age, ethnic origin, and a pronounced acid suppression. However, the only factor of independent importance in this study was prolonged and profound acid inhibition.

Adult↗
PubMed1997

Anemia associated with advanced prostatic adenocarcinoma: effects of recombinant human erythropoietin.

BACKGROUND AND METHODS: Nine patients with hormone-refractory metastatic prostatic adenocarcinoma and anemia were treated with recombinant human erythropoietin (rHuEpo) at a median dose of 150 U/kg BW 3 times a week subcutaneously. Baseline hemoglobin (Hb) ranged from 70 to 116 g/L, and the study duration was 12 weeks (median patient participation period was 8 weeks). RESULTS: Four patients demonstrated a median Hb increase of 20 g/L and were considered responders. Three patients showed a median increase of 17 g/L but required blood transfusion once, and were therefore considered as partial responders. Baseline erythropoietic status showed a significant correlation between serum Epo and Hb. Inadequate Epo production, evaluated by the observed/predicted log Epo ratio, was found in two patients. Defective bone marrow activity, demonstrated by low transferrin receptor (TfR), and hypoferremia in spite of abundant iron stores were also shown. Hemorheological investigations showed elevated plasma viscosity. CONCLUSIONS: Our results indicate that suppression of erythropoiesis can be mainly explained by the depressed marrow activity. The altered hemorheology might contribute to the anemia. This anemia could possibly be corrected with rHuEpo.

Adenocarcinoma↗
PubMed1997

Effects of extracorporeal hemapheresis therapy on blood rheology.

The blood flow property is one of the factors determining blood perfusion and oxygen supply. The viscosity of the blood is primarily related to the hematocrit, but also to the amount of fibrinogen and other macromolecules present in the blood. Patients with ischemic heart disease have shown a rapid and safe improvement in their hemorheological state when treated with heparin-induced extracorporeal low-density lipoprotein (LDL) precipitation (HELP). In this study we used two extracorporeal hemapheresis methods, plasmapheresis (PP) and immunoadsorption (IA), in 15 patients (eight patients treated with PP and seven patients with IA) with various diseases. Hemorheological variables and plasma fibrinogen were measured before and after the first and before the third treatment performed at 3 consecutive days. The aim of our study was to investigate the immediate effects of these two treatment modalities on the flow properties of blood. Immediately after the first PP and IA session statistically significant declines in plasma fibrinogen concentration, plasma viscosity, whole blood viscosity, and erythrocyte aggregation tendency were found. These changes persisted before the third treatment session. The erythrocyte fluidity and hematocrit remained unchanged. We conclude that extracorporeal hemapheresis therapy, with plasmapheresis or immunoadsorption, affects the blood rheology by decreasing the plasma viscosity and erythrocyte aggregation tendency. The decrease in plasma fibrinogen is probably the main factor underlying that, but other factors such as a decrease in immunoglobulins may also be of importance.

Adult↗
PubMed1997

Acute renal failure and outcome of continuous arteriovenous hemodialysis (CAVHD) and continuous hemofiltration (CAVH) in elderly patients following cardiovascular surgery.

A total of 111 elderly patients from the cardiac surgery intensive care unit (ICU) with acute renal failure (ARF) were studied during a period of 7 years (1988-1994). Forty-two patients being operated for coronary bypass (CBP) (31 M, 11 F), 26 patients for valve replacement (VR) (18 M, 8 F), 20 patients for a combined operation of coronary bypass and valve replacement (CBP+VR) (14 M, 6 F) and 23 patients for resection of aneurysm of the abdominal aorta (ROAOAA) (11 M, 12 F). Average age of the patients was 70 +/- 4 yr (65-80). Their blood pressure on the first day of continuous renal replacement therapy (CRRT) was 75 +/- 19 mmHg (50-95) and was maintained at about 95 +/- 15 mmHg (70-120) by using vasopressor drugs. From the results of this study a survival of 38% was registered within the CBP group, 65% within the VR group, 45% within the CBP+VR group and 91% within the ROAOAA group. The overall survival in all of the patients was 58%. It was a high mortality (62%) within CBP group compared to that of 35%, 55% and 9% within the VR, CBP+VR and ROAOAA groups, respectively. This is because more patients with predisposing preoperative risk factors, e.g., hypertension (33%) and Diabetes (17%) etc were found in the CBP group, in addition to their post operative complications of which bleeding necessitating reoperations was encountered in 31%. Multiple organ failure (MOF) was a common major problem of which respiratory failure needing artificial ventilation was encountered in about 90% of the patients. The overall mortality was 42% in which the major cause of death was MOF/circulatory failure. Heart failure was the second cause of death. Other secondary complications, e.g., liver failure (n = 6) and atrial fibrillation (n = 11) etc. might have added to the high mortality in this study. The effect of CRRT on uremic control was measured by following-up of the daily levels of the serum urea and creatinine and a steady-state uremic control was achieved. We conclude that CRRT can be considered as a reliable artificial renal support for ARF in ICU elderly patients.

Acute Kidney Injury↗
PubMed1997

Lung density for assessment of hydration status in hemodialysis patients using the computed tomographic densitometry technique.

The density of the lung reflects the total mass of fluid, air, and dry lung tissue per unit volume of the lung. Lung density can be measured by evaluation of attenuation of an electron beam with computed tomography (CT). This technique has been shown to be sufficiently reliable and sensitive to distinguish normal from abnormal lung water. The aim of this study was to find out whether lung density properly reflects the hydration status in hemodialysis patients in comparison with other standard methods. Fourteen hemodialysis patients, with an ultrafiltration ranging from 0.3 to 4.5 liters per session, underwent CT measurements of lung density, ultrasonographic measurements of the diameter of the inferior vena cava after quiet expiration (IVCe) and quiet inspiration (IVCi), and measurements of the hematocrit and plasma levels of the biochemical hydration markers cyclic guanosine monophosphate (cGMP) and atrial natriuretic peptide (ANP). These measurements were performed before and 3.5 to 4 hours after termination of dialysis. Quantitative estimates of lung density were obtained within pixels with CT numbers ranging between -1000 and -100 Hounsfield Units (HU), and compared with normal data from 18 normal controls. In normal controls, the lung density ranged from -800 to -730 HU. In hemodialysis patients, lung density was significantly higher than normal before dialysis (-678 +/- 96 HU, P < 0.01) and significantly decreased after dialysis (-706 +/- 92 HU, P < 0.05), indicating a decrease in fluid content of the lung. The density was normalized in 5 patients. A significant correlation was found between lung density and IVCe both before and after dialysis (r = 0.8, P < 0.01 for both). Change in density was significantly correlated to amount of ultrafiltration (r = 0.67, P < 0.01) and percent change in blood volume (r = 0.63, P < 0.05), indicating that lung density is greatly affected by changes in the extracellular fluid volume, mainly the intravascular volume. In conclusion, lung water reflects the hydration status in hemodialysis patients and can be monitored by measuring the lung density by CT. Accordingly, normalization of lung density can help to achieve a proper dry weight in these patients.

Adult↗
PubMed1997

Gender and age differences in transthoracic bioimpedance.

Thoracic impedance consists of a constant baseline component Z0 and a time-variable component delta Z which represents the impedance change related to the cardiac cycle. The maximum part of delta Z [(dZ/dt)max] represents the peak of the ascending aortic blood flow. Measurements of basal thoracic impedance are affected by structural and anatomical differences in the thorax related to sex and ageing. This component is a variable in the denominator of Sramek's formula which is used for calculating stroke volume. The aim of this study was to elucidate the question as to whether the age- and sex-related variation in basal impedance may affect bioimpedance measurements of stroke volume. The study comprised 111 healthy subjects (55 males and 56 females) of ages between 20 and 69 years, divided according to age decades into five groups each of males and females. Stroke volume index (SI), Z0 and (dZ/dt)max were measured in every subject, using transthoracic bioimpedance cardiography. Z0 and (dZ/dt)max had significantly higher values in females than in males in every age group except the oldest one in the case of Z0 and the oldest two groups in the case of (dZ/dt)max. Stroke index showed no significant sex difference, although the higher Z0 in females may underestimate the values of stroke index. Elevation of (dZ/dt)max in females may therefore reflect a positive relation to Z0 rather than higher flow rates. Since Z0 and (dZ/dt)max are variants in opposite positions in Sramek's formula (denominator and numerator, respectively), this functional relationship may keep the bioimpedance measurements from being affected by the sex- and age-related changes in Z0.

Adult↗
PubMed1997

The required dose of erythropoietin during renal anaemia treatment is related to the degree of impairment in erythrocyte deformability.

BACKGROUND: Renal anaemia is rapidly corrected by recombinant human erythropoietin (rHuEpo) therapy, but the dose required varies greatly. Since impaired erythrocyte deformability may be one factor contributing to the development of renal anaemia, the interrelationship between that variable and the rHuEpo requirement was examined. METHODS: Twenty-five patients treated with hemodialysis and rHuEpo for at least 6 months were included in the study. The Hb value had been stable and the rHuEpo dose unchanged the last two months. Using a rotational viscometer, the fluidity of erythrocytes, separated from plasma and re-suspended in isotonic buffered saline to a standardized haematocrit, was taken as a measure of erythrocyte deformability. RESULTS: The average weekly dose of s.c. epoetin alpha was 186 +/- 93 U/kg body weight (range 56-370). The dose was correlated to the reticulocyte fraction (R = 0.69, P = 0.0001). When the rHuEpo dose was used as dependent variable and blood haemoglobin concentration, serum (S) albumin, S ferritin, S aluminium, S PTH, S urea, Kt/V/week, erythrocyte fluidity, and plasma viscosity were used as independent variables in a stepwise multiple regression analysis, only erythrocyte fluidity remained significantly negatively correlated to the rHuEpo dose (R = 0.5, P = 0.01). Despite a tendency towards higher doses of rHuEpo in patients with a C-reactive protein concentration exceeding 20 mg/l, the Hb was lower in these patients. CONCLUSIONS: We conclude that the interindividual differences in bone marrow response to rHuEpo were small in these patients. Impaired erythrocyte deformability and inflammation seem to be factors associated with increased rHuEpo requirement.

Adult↗