Biomedical subjects

Per Bjellerup

Publications and source records attributed to Per Bjellerup.

9 recordsLinked to original sources

PubMed2006

Daily dialyses decrease plasma levels of brain natriuretic peptide (BNP), a biomarker of left ventricular dysfunction.

Brain natriuretic peptide or B-type natriuretic peptide (BNP) is a sensitive marker of heart disease. Plasma levels of BNP increase in left ventricular failure and determination of plasma BNP has become a useful tool in the diagnosis of heart failure. Hemodialysis (HD) patients may have elevated plasma levels of BNP, particularly predialysis, that correlate with echocardiographic signs of left ventricular dysfunction. High BNP levels are also a strong predictor of mortality in both nonrenal and HD patients. We studied plasma BNP levels in patients who changed from conventional thrice-weekly dialysis to daily dialysis 6 times a week while maintaining a total weekly time on dialysis of 12 hr. Twelve HD patients, mean age 55 years, had 4 hr of conventional thrice-weekly treatment for 4 weeks. Predialysis and postdialysis blood samples were obtained at the last dialysis. Patients were then dialyzed for 2 hr, 6 times weekly, for 4 weeks (daily dialysis). Again, predialysis and postdialysis blood samples were collected at the last HD. Brain natriuretic peptide plasma concentrations were determined by immunoradiometric assay. Predialysis BNP levels decreased from 194+/-51 ng/L (68+/-19 pmol/L; mean+SE) during thrice-weekly HD to 113+/-45 ng/L (41+/-18 pmol/L; p = 0.001) after 4 weeks on daily dialysis. With thrice-weekly HD, predialysis BNP levels were higher than postdialysis levels: 120+/-26 ng/L (39+/-8 pmol/L; p = 0.059). With daily dialysis, predialysis BNP levels did not differ significantly from postdialysis levels. Elevated predialysis plasma levels of BNP, considered sensitive and early markers of left ventricular dysfunction, decreased when patients were changed from conventional thrice-weekly HD to daily dialysis maintaining total hours of dialysis per week constant. Given the accumulated evidence that BNP is a biomarker of left ventricular dysfunction and can be used for risk stratification and guidance in pharmacotherapy of heart failure, daily dialysis appears to lead to less cardiac distress.

Adult↗

PubMed2006

Cadmium-induced effects on bone in a population-based study of women.

High cadmium exposure is known to cause bone damage, but the association between low-level cadmium exposure and osteoporosis remains to be clarified. Using a population-based women's health survey in southern Sweden [Women's Health in the Lund Area (WHILA) ] with no known historical cadmium contamination, we investigated cadmium-related effects on bone in 820 women (53-64 years of age) . We measured cadmium in blood and urine and lead in blood, an array of markers of bone metabolism, and forearm bone mineral density (BMD) . Associations were evaluated in multiple linear regression analysis including information on the possible confounders or effect modifiers: weight, menopausal status, use of hormone replacement therapy, age at menarche, alcohol consumption, smoking history, and physical activity. Median urinary cadmium was 0.52 microg/L adjusted to density (0.67 microg/g creatinine) . After multivariate adjustment, BMD, parathyroid hormone, and urinary deoxypyridinoline (U-DPD) were adversely associated with concentrations of urinary cadmium (p < 0.05) in all subjects. These associations persisted in the group of never-smokers, which had the lowest cadmium exposure (mainly dietary) . For U-DPD, there was a significant interaction between cadmium and menopause (p = 0.022) . Our results suggest negative effects of low-level cadmium exposure on bone, possibly exerted via increased bone resorption, which seemed to be intensified after menopause. Based on the prevalence of osteoporosis and the low level of exposure, the observed effects, although slight, should be considered as early signals of potentially more adverse health effects. Key words: biochemical bone markers, bone mineral density, cadmium, lead, osteoporosis, women.

Absorptiometry, Photon↗

PubMed2005

Tubular and glomerular kidney effects in Swedish women with low environmental cadmium exposure.

Cadmium is a well-known nephrotoxic agent in food and tobacco, but the exposure level that is critical for kidney effects in the general population is not defined. Within a population-based women's health survey in southern Sweden (Women's Health in the Lund Area, WHILA), we investigated cadmium exposure in relation to tubular and glomerular function, from 1999 through early 2000 in 820 women (71% participation rate) 53-64 years of age. Multiple linear regression showed cadmium in blood (median, 0.38 microg/L) and urine (0.52 microg/L; density adjusted = 0.67 microg/g creatinine) to be significantly associated with effects on renal tubules (as indicated by increased levels of human complex-forming protein and N-acetyl-beta-D-glucosaminidase in urine), after adjusting for age, body mass index, blood lead, diabetes, hypertension, and regular use of nephrotoxic drugs. The associations remained significant even at the low exposure in women who had never smoked. We also found associations with markers of glomerular effects: glomerular filtration rate and creatinine clearance. Significant effects were seen already at a mean urinary cadmium level of 0.6 microg/L (0.8 microg/g creatinine). Cadmium potentiated diabetes-induced effects on kidney. In conclusion, tubular renal effects occurred at lower cadmium levels than previously demonstrated, and more important, glomerular effects were also observed. Although the effects were small, they may represent early signs of adverse effects, affecting large segments of the population. Subjects with diabetes seem to be at increased risk.

Acetylglucosaminidase↗

PubMed2004

Galanin in pituitary adenomas.

Tumor galanin content was measured in extracts from human pituitary adenomas using a specific RIA method for monitoring human galanin. Twenty-two out of twenty-four tumors contained galanin with notably high levels in corticotroph adenomas, varying levels in clinically inactive tumors, and low levels in GH secreting adenomas. Tumor galanin and ACTH contents were closely correlated in all tumors. In four young patients with microadenomas and highly active Mb Cushing tumor galanin was inversely related to tumor volume. The molecular form of tumor galanin, studied with reverse-phase HPLC, was homogeneous with the majority of tumor galanin coeluting with standard human galanin. In the tumors analysed with in situ hybridization there was a good correlation between galanin peptide levels and galanin mRNA expression. In some tumors galanin mRNA and POMC levels coexisted, in others they were essentially in different cell populations. Levels of plasma galanin-LI were not related to tumor galanin concentration, and galanin levels were in the same range in sinus petrosus close to the pituitary venous drainage as in peripheral blood. Corticotrophin releasing hormone injections in two patients caused ACTH, but no detectable galanin release into sinus petrosus. Our results demonstrate that corticotroph, but not GH adenomas, express high levels of galanin, in addition to ACTH, and that in some tumors both polypeptides are synthesised in the same cell population. However, galanin levels in plasma were not influenced by the tumor galanin content.

Adenoma↗

PubMed2004

Bone turnover from early pregnancy to postweaning.

BACKGROUND: To elucidate the sequences of changes in bone metabolism and bone density during pregnancy, lactation and postweaning. METHODS: Women were recruited (n = 254) in early pregnancy and followed for 2 years. Markers of bone formation (osteocalcin) and resorption (NTx) were measured at five occasions. Bone mineral density (BMD) of whole-body and lumbar spine L1-L4 (DXA) and ultrasonography of os calcis were measured in a subgroup (n = 14). RESULTS: NTx appeared bone specific in comparison to pyridinolines. NTx started to increase early in pregnancy and remained elevated during lactation (p < 0.001). Osteocalcin was low during pregnancy, but peaked during lactation (p < 0.018). The subsequent decrease was associated with time since resumption of menses (r2 = 0.23; p < 0.001). There was indication of a decrease in calcaneal bone mass during pregnancy and an evident decrease in lumbar spine (p = 0.041) and os calcis (p = 0.037) during lactation. No detectable decrease was identified in whole-body BMD (p = 0.090) during lactation, but in general, BMD was higher in whole-body (1.9%) and lumbar spine (6.6%) 18 months postpartum than during puerperium (p = 0.003). CONCLUSION: According to the bone metabolic markers, bone resorption increased early in pregnancy and remained elevated over lactation, while bone formation increased during lactation, probably regulated by mechanisms associated with absence of menses. The high metabolic bone turnover during late pregnancy and lactation lead to a decline in cancellous bone mass during lactation, but this seemed beneficial for BMD postweaning.

Absorptiometry, Photon↗

PubMed2002

Soluble transferrin receptor: longitudinal assessment from pregnancy to postlactation.

OBJECTIVE: To assess the impact of pregnancy and lactation on iron status and erythropoiesis as measured by the soluble transferrin receptor (sTfR). METHODS: We recruited women in early pregnancy to be followed for 2 years. We determined sTfR and sTfR/serum ferritin (sTfR/Fer) during puerperium (n = 77), lactation (n = 111), and postlactation (n = 57), with comparison to data obtained during pregnancy (n = 224). Data were evaluated using analysis of variance for repeated measures as the women continuing the study were found to be representative of those entering the study. RESULTS: We found that sTfR and sTfR/Fer were significantly higher at all sampling occasions compared with early pregnancy (P <.001). Iron status markers did not regain first-trimester levels postpartum. Postlactation, 20% of the women had depleted iron stores (sTfR/Fer greater than 500), and 10% had tissue iron deficiency (sTfR greater than 8.3 mg/L). Iron status worsened with increasing parity and was significantly correlated to blood loss at delivery. In a subgroup of women with persistent adequate iron stores, first-trimester sTfR was similar to that in the puerperium but significantly lower than that postlactation. Cord sTfR (n = 32) was twice maternal sTfR and not correlated to maternal serum ferritin, gestational age, or other birth variables. CONCLUSION: Our data show decreased erythropoiesis in early gestation and during the first week of the puerperium. To prevent a negative effect of childbearing on iron status, postpartum iron supplementation should be considered in women who bleed excessively at parturition and in those who choose to take a low dose of iron or none at all during pregnancy.

Anemia, Iron-Deficiency↗

PubMed2002

Diltiazem infusion for renal protection in cardiac surgical patients with preexisting renal dysfunction.

OBJECTIVE: To evaluate if the calcium channel blocker diltiazem protects postoperatively renal function in cardiac surgical patients with preexisting mild-to-moderate renal dysfunction. DESIGN: Prospective, randomized, placebo-controlled, double-blind, clinical study. SETTING: Cardiothoracic anesthesia department at a university hospital. PARTICIPANTS: Adult patients undergoing elective cardiac surgery using cardiopulmonary bypass, with a preoperatively elevated serum creatinine level (n = 24). INTERVENTIONS: Randomized infusions of diltiazem (bolus 0.25 mg/kg followed by a continuous infusion of 1.7 microg/kg/min) (DTZ, n = 12) or placebo (C, n = 12) were started 30 minutes before induction of anesthesia and continued for 24 hours. MEASUREMENTS AND MAIN RESULTS: Median plasma concentrations of diltiazem (DTZ group) were 79 microg/L before cardiopulmonary bypass, 67 microg/L at the end of cardiopulmonary bypass, and 164 microg/L at 24 hours postoperatively. Serum creatinine levels; on postoperative days 1, 3, and 5; and 3 weeks postoperatively were similar between groups. Iohexol clearance did not differ between the groups on day 5 but was higher in the DTZ group than in the placebo group 3 weeks after surgery (median, 51 v 40 mL/min/1.73 m(2); p < 0.05). Urinary N-acetyl-beta-glucosamidase concentrations were similar between the groups during the study but were increased from baseline on days 2 and 4 and 3 weeks postoperatively. CONCLUSION: Diltiazem can be safely used in patients who have mild-to-moderate renal dysfunction and undergo cardiac surgery using cardiopulmonary bypass. Within the limits of this study, the data suggest that addition of prophylactic diltiazem may prevent further glomerular damage resulting from cardiopulmonary bypass and may improve glomerular function 3 weeks after cardiac surgery.

Acetylglucosaminidase↗

PubMed2002

Cadmium exposure in pregnancy and lactation in relation to iron status.

OBJECTIVES: The purpose of this study was to determine the impact of iron status on cadmium dose among pregnant women. METHODS: Iron status and cadmium concentration in blood, urine, and placenta were determined among women followed for 2 years from early pregnancy. RESULTS: Blood cadmium and urinary cadmium were correlated with iron status throughout the study period. Urinary cadmium increased longitudinally among women with exhausted iron stores during their pregnancy. The increase in urinary cadmium with age was more pronounced in multiparous than in nulliparous women. CONCLUSIONS: Iron deficiency during pregnancy leads to increased cadmium absorption and body burden. Multiparous women exhibit additional increases with increasing age.

Adult↗

PubMedDate not supplied

[Laboratory thyroid disease diagnosis--interdisciplinary cooperation. International consensus in Swedish perspective].

In 2003, The National Academy of Clinical Biochemistry published a consensus monograph on thyroid tests (available via Internet from 2002). The document, a result of international collaboration, describes the pathophysiological background and clinical application of the measurements as well as principles for their technical performance. Of value, and of definite clinical relevance, is the detailed description of factors affecting the results in health and disease. However, we lack a description of the sometimes large differences in values obtained with different generally available methods, as well as a presentation of the occurrence and evaluation of analytical interference and related technical factors affecting results. Readers with little experience from quantitative measurement in the clinical laboratory, therefore, are not stimulated to obtain a better understanding of causes and evaluation of unexpected results.

Autoantibodies↗