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Pekka Leinonen

Publications and source records attributed to Pekka Leinonen.

10 recordsLinked to original sources
PubMed2005

The effect of extracellular calcium concentration on calcium-mediated cell signaling in NF1 tumor suppressor-deficient keratinocytes.

Capacitative calcium entry and calcium wave propagation were studied in keratinocytes from healthy volunteers and patients with type 1 neurofibromatosis (NF1) in calcium-depleted and in low calcium culture medium. In previous studies, we found evidence that mutations of the NF1 tumor suppressor gene can lead to altered calcium-mediated cell signaling in keratinocytes cultured in the presence of a high extracellular calcium concentration. The present study demonstrated that the differences between normal and NF1 keratinocytes were dependent on extracellular calcium concentration. Specifically, when keratinocytes were exposed to thapsigargin under calcium-depleted culture conditions the subsequent increase in free intracellular calcium concentration was moderate in NF1 keratinocytes compared to controls. The finding indicates lowered endoplasmic calcium stores in NF1 which may also in part explain the reduced activation signal for capacitative calcium influx and the wound-induced intracellular Ca2+ transient observed in NF1 keratinocytes maintained in culture medium containing 0.05 mM calcium. The differences between control and NF1 keratinocytes were most pronounced when the cells were cultured in the presence of a high (1.8 mM) calcium concentration. Since elevated extracellular calcium levels induce keratinocytes to form cellular contacts and lead to terminal differentiation, markedly aberrant responses of NF1 keratinocytes in the presence of a high calcium concentration may help to explain previous findings on impaired formation of cellular junctions and differentiation in NF1 deficient cells.

Adult↗
PubMed2005

Concentration of cord serum placenta growth factor in normal and diabetic pregnancies.

OBJECTIVE: To investigate whether maternal diabetes or diabetes-related complications, such as macrosomia and chronic fetal hypoxia, are associated with altered placenta growth factor (PlGF) levels in cord serum. DESIGN: Case-control study. SETTING: Helsinki University Central Hospital, Helsinki, Finland. POPULATION: Sixty-two normal pregnancies, 67 pregnancies complicated by type 1 diabetes and 28 pregnancies complicated by insulin-treated gestational diabetes. METHODS: Cord serum PlGF concentration was measured by an enzyme-linked immunosorbent assay. Amniotic fluid erythropoietin concentration was measured by a chemiluminescent immunologic method. Umbilical artery gas variables were analysed with standard blood gas and pH electrodes. MAIN OUTCOME MEASURE: PlGF concentration in cord serum at birth. RESULTS: Cord serum PlGF concentration was similar in normal pregnancies [13.4 (1.0) ng/L], in pregnancies complicated by type 1 diabetes [15.1 (1.8) ng/L, P= 0.583 vs controls] and in pregnancies complicated by insulin-treated gestational diabetes [13.6 (0.9) ng/L, P= 0.991 vs controls]. Cord serum PlGF did not correlate with relative birthweight. In diabetic pregnancies, cord serum PlGF correlated negatively with amniotic fluid erythropoietin (r=-0.449, P < 0.0001) and positively with umbilical artery Po(2) (r= 0.333, P= 0.001). There was a trend toward lower cord serum PlGF levels in diabetic pregnancies with pre-eclampsia compared with those without any hypertensive disorders. CONCLUSIONS: Maternal diabetes per se is not associated with altered PlGF levels in cord serum. The correlation between PlGF and indices of fetal hypoxia in diabetic pregnancies may be related to the role of PlGF in potentiating the angiogenic response to vascular endothelial growth factor in ischaemia.

Adult↗
PubMed2004

Sex hormone-binding globulin and insulin-like growth factor-binding protein-1 as indicators of metabolic syndrome, cardiovascular risk, and mortality in elderly men.

Two binding proteins, SHBG and IGF-binding protein-1 (IGFBP-1), are both down-regulated by insulin and therefore could serve as potential indicators of the metabolic syndrome and hyperinsulinemia-related cardiovascular risk. We compared serum SHBG and IGFBP-1 as potential markers of abnormal glucose tolerance, the metabolic syndrome, diabetes mellitus, cardiovascular risk factors, and total, cardiovascular, and coronary heart disease mortality in elderly men. Of the original cohort of 1711 men, 524 were alive on January 1, 1989, and 413 participated in the 30-yr examination, of whom 335 men, aged 70-89 yr, formed the study group for the present analysis. Low SHBG and IGFBP-1 were both associated with an increased prevalence of abnormal glucose tolerance and the metabolic syndrome, but only SHBG was associated with diabetes mellitus. SHBG was less influenced by body mass index than IGFBP-1. Low SHBG indicated increased cardiovascular and coronary disease mortality; the association remained after adjustment for abnormal glucose tolerance, but not after adjustment for prevalent cardiovascular disease. IGFBP-1 had no association with mortality. It is concluded that low SHBG is a better indicator of increased cardiovascular mortality than low or high IGFBP-1.

Aged↗
PubMed2004

Fetal hypoxia is associated with elevated cord serum C-reactive protein levels in diabetic pregnancies.

Maternal diabetes increases the risk of intrauterine hypoxia. Inflammation may play a role in the pathogenesis of hypoxia-related neonatal complications. We studied correlations between levels of cord serum C-reactive protein (CRP), measured by a highly sensitive immunofluorometric assay, and indices of fetal hypoxia in diabetic pregnancies. Cord serum CRP correlated positively with amniotic fluid erythropoietin and umbilical artery pCO2. A negative correlation existed between cord serum CRP and umbilical artery pH and pO2. Amniotic fluid erythropoietin showed an independent effect on cord serum CRP in multiple regression analysis. These data suggest that the fetus responds to hypoxia by an inflammatory reaction.

Adult↗
PubMed2004

Diabetic pregnancy associated with increased epidermal growth factor in cord serum at term.

OBJECTIVE: Epidermal growth factor is a ubiquitous mitogen that also possesses insulin-like properties. Fetal mal-growth is associated with altered epidermal growth factor levels. Maternal diabetes is frequently complicated by macrosomia, but the effect of maternal diabetes on fetal epidermal growth factor levels is not known. We studied cord serum epidermal growth factor concentrations in pregnancies complicated by diabetes and in normal pregnancies. METHODS: Cord serum epidermal growth factor concentrations were measured at birth by a sandwich-type time-resolved immunofluorometric assay in 63 pregnancies complicated by insulin-dependent diabetes mellitus, in 25 pregnancies complicated by insulin-treated gestational diabetes, and in 56 normal pregnancies. RESULTS: Cord serum epidermal growth factor correlated positively with the duration of pregnancy in diabetic and normal pregnancies. In a subgroup of women at similar gestational ages (38-39 weeks), cord serum epidermal growth factor concentrations were higher in pregnancies complicated by insulin-dependent diabetes mellitus (962 +/- 211 ng/L, P =.047; n = 9) and in pregnancies complicated by gestational diabetes (1133 +/- 115 ng/L, P =.001; n = 9) than in controls (564 +/- 75 ng/L; n = 22). In multiple regression analysis, only umbilical artery hemoglobin in diabetic pregnancies and vaginal delivery in normal pregnancies were associated with cord serum epidermal growth factor. CONCLUSION: Epidermal growth factor concentrations are higher than normal in fetuses of diabetic mothers at term. Pregnancy complications, such as hypertensive disorders, fetal hypoxia and fetal malgrowth, may not explain the rise in epidermal growth factor levels. We hypothesize that the rise in epidermal growth factor levels is a metabolic response of the fetoplacental unit to diabetes-related hyperglycemia. LEVEL OF EVIDENCE: III

Adult↗
PubMed2003

Cord serum glycodelin concentrations in normal pregnancies and pregnancies complicated by diabetes.

OBJECTIVE: Glycodelin is a glycoprotein released by secretory/decidualized endometrial glands. Its synthesis increases during pregnancy. Hormonal factors whose levels have been shown to change in diabetes (vascular endothelial growth factor, relaxin) may mediate the actions or regulate the synthesis of glycodelin. Cord serum glycodelin levels have not been studied in pregnancies complicated by diabetes. METHODS: Cord serum glycodelin concentrations were measured at birth by an immunofluorometric assay in 62 normal pregnancies, in 67 pregnancies complicated by type 1 diabetes, and in 28 pregnancies complicated by insulin-treated gestational diabetes. RESULTS: The mean glycodelin concentration in cord serum was 2.7 ng/ml (standard error of the mean 0.6) in normal pregnancies. The concentration was not altered in pregnancies complicated by diabetes. Cord serum glycodelin concentrations were also unaltered in diabetic pregnancies with hypertensive disorders (chronic hypertension, pregnancy-induced hypertension or pre-eclampsia) or fetal macrosomia. There was a negative borderline correlation between cord serum glycodelin concentrations and the birth weight in pregnancies complicated by diabetes (r=-0.21, p=0.049). CONCLUSIONS: Decidual function, as assessed by cord serum glycodelin levels, is not markedly altered in diabetic pregnancies. The negative correlation between cord serum glycodelin and the birth weight of the newborns in diabetic pregnancies may be due to the decline in glycodelin levels with advancing pregnancy in the third trimester.

Adult↗
PubMed2002

Serum insulin-like growth factor-I and insulin-like growth factor binding protein-3 in premature rupture of membranes.

BACKGROUND: The aim of the study was to evaluate whether the circulating levels of insulin-like growth factor-I (IGF-I) and its major circulating binding protein, IGFBP-3, are affected in premature rupture of membranes (PROM) and preterm delivery. METHODS: The levels of IGF-I and IGFBP-3 were measured in 32 pregnant women with PROM and in 27 healthy gestational age-matched pregnant women. Statistical analyzes were performed by analysis of variance. RESULTS: All the patients with PROM had preterm delivery, at a gestational age of 31.9 +/- 0.4 weeks (mean +/- SEM). In the control subjects, pregnancy proceeded to term. In the PROM patients, the serum IGF-I and IGFBP-3 levels (289 +/- 21 ng/ml and 8248 +/- 407 ng/ml, respectively) were not statistically different from those in the control subjects (275 +/- 22 ng/ml and 7579 +/- 488 ng/ml). Seventeen patients with PROM showed a rise in serum C-reactive protein, indicating subclinical intrauterine infection. Also in this subgroup of patients the levels of serum IGF-I (281 +/- 27 ng/ml) and IGFBP-3 (9010 +/- 633 ng/ml) were not different from those in the control subjects. Before delivery, serial serum samples were available from 22 patients with PROM. No consistent changes in IGF-I or IGFBP-3 concentrations were seen during the mean follow-up period of 9 days. CONCLUSIONS: IGF-I and IGFBP-3 do not appear to play any significant role in the maintenance of pregnancy in PROM patients with preterm delivery, whether or not associated with emerging intrauterine infection.

Adult↗
PubMed2002

Postpartum bone mineral density in women treated for thromboprophylaxis with unfractionated heparin or LMW heparin.

Venous thromboembolism remains an important cause of maternal mortality. In a randomised open study, 44 pregnant women with confirmed previous or current thromboembolism were randomised to receive either low-molecular-weight heparin, dalteparin (N = 21) once daily subcutaneously or unfractionated sodium heparin (UF heparin, N = 23) twice daily subcutaneously for thromboprophylaxis during pregnancy and puerperium. Bone mineral density (BMD) in the lumbosacral spine was measured with dual X-ray absorptiometry (DEXA) 1, 6, 16, 52 weeks and, if possible, 3 years after delivery. BMD values were also compared with those of healthy, delivered women (N = 19). Mean BMD of the lumbar spine was significantly lower in the unfractionated heparin group compared with the dalteparin and with the control groups (repeated measures ANOVA p = 0.02). BMD in the dalteparin group did not differ from BMD of healthy delivered women. Multiple logistic regression analysis revealed that therapy was the only independent factor influencing BMD at weeks 16 and 52. Therefore we recommend use of dalteparin instead of UF heparin for long-term thromboprophylaxis during and after pregnancy.

Absorptiometry, Photon↗