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Biomedical subjects

M Westgren

Publications and source records attributed to M Westgren.

At least 73 records · Page 4Linked to original sources
PubMed1995

Continuous maternal glucose infusion during labor: effects on maternal and fetal glucose and lactate levels.

Fetal and neonatal glucose and lactate levels and acid-base balance after continuous maternal infusion of 5% dextrose at 180 mL/h (9 g/h) was compared with 0.9% saline solution in a prospective, randomized study from selected monitored labors. An infusion of 5% dextrose produced significantly increased glucose levels in maternal (p < 0.01), cord artery (p < 0.01), and cord vein (p < 0.001) blood. An increased maternal insulin level was also present (p < 0.05), but no differences in cord insulin levels were observed. beta-Hydroxybutyrate was lower in maternal (p < 0.05) and cord vein (p < 0.01), but not in cord artery blood, after maternal dextrose infusion. No significant changes occurred in blood lactate levels between the two groups in either mother, fetus, cord, or neonate. Acid-base balance in cord blood did not differ between the two groups. Maternal infusion of 5% dextrose at 180 mL/h (9 g/h), compared with saline solution, produces higher glucose levels in both mother and fetus, but increased insulin concentrations only in the mother. Dextrose infusion also lowers beta-hydroxybutyrate in maternal and cord vein blood. No differences were seen in lactate levels or cord acid-base balance. Both regimens seem safe according to risks for lactacidosis and neonatal hypoglycemia in the normoxemic, normal size fetus.

3-Hydroxybutyric Acid↗
PubMed1995

Scalp blood lactate: a new test strip method for monitoring fetal wellbeing in labour.

OBJECTIVE: To determine fetal scalp blood lactate with a new test strip method in parturients with normal and abnormal cardiotocograms during labour and to describe the relation to maternal lactate, fetal scalp blood pH, cord artery lactate and acid-base balance. SETTING: Labour wards at the University Hospitals of Huddinge and Lund and at the County Hospital of Ostersund, Sweden. MATERIALS AND METHOD: Fetal scalp blood was sampled for lactate (n = 269) and pH (n = 285) determination in 177 parturients with abnormal intrapartum CTG. Lactate and pH were also analysed in a group of 64 women with normal pregnancies and with a reactive fetal heart rate tracing prior to sampling of fetal scalp blood. At fetal blood sampling lactate was also determined in maternal capillary blood, while at birth lactate and acid-base balance in cord artery blood was performed in almost all cases. MAIN OUTCOME MEASUREMENTS: Medians and percentiles (lactate and acid-base balance). Correlation between fetal scalp blood lactate (dependent) and scalp blood pH, cord artery blood lactate and acid-base parameters and labour time prior to fetal blood sampling. RESULTS: In the group with abnormal cardiotocograms, fetal scalp and umbilical artery blood lactate and acid-base parameters differed significantly from the same parameters in the normal group. The fetal-maternal lactate gradient changed from negative in the normal group to positive in the fetal distress group. Multiple regression analysis, with scalp lactate as the dependent parameter, revealed a significant correlation with fetal scalp blood pH (P < 0.001) and umbilical artery lactate (P < 0.01). CONCLUSIONS: Intrapartum scalp blood lactate was significantly correlated with pH and cord artery lactate. The results indicate that increased lactate levels in fetal blood sampling describes fetal lactacidosis. The new disposable test strip requiring only 5 microliters of blood for lactate determination may be better than traditional methods for monitoring fetal wellbeing in labour.

Acid-Base Equilibrium↗
PubMed1995

Cordocentesis.

During the last decade cordocentesis has become common procedure in perinatal medicine. Although the method represents potential possibilities, it is also afflicted with several limitations. The present review focuses on technique, indications, and complications.

Bradycardia↗
PubMed1994

The interpretation of uterine artery pulsatility index in normal and hypertensive pregnancy.

The Doppler flow velocity pulsatility index (PI) of the uteroplacental vascular bed is of debatable value for the interpretation of hemodynamic changes, when these are due both to pathological alterations in the vasculature, as in mild pre-eclampsia, and to physiological adjustments to vasoactive substances. The aim of this study was to apply a mathematical model, which includes maternal pulse pressure and mean arterial pressure, to the PI and to investigate whether this formula would add information with respect to discrimination between normal women and those with mild or severe pre-eclampsia. The subjects were patients with mild (n = 41) and severe (n = 34) pre-eclampsia and, as a control group, healthy pregnant women (n = 46). The uterine artery PI was studied by spectral Doppler analyses and compared to a P(z) value, theoretically representing a 'back pressure' in the uteroplacental circulation. Additionally, P(z) values were computed from earlier data concerning the dynamic circulatory effects of dihydralazine and acute volume expansion. The basal PI was significantly higher in the severely pre-eclamptic patients but not in the mildly pre-eclamptic patients compared to the controls. However, the P(z) was significantly higher in patients with both mild (p < 0.001) and severe pre-eclampsia (p < 0.0001) compared to the normal group. In the severely pre-eclamptic patients receiving dihydralazine, the P(z) tended to decrease (p = 0.07), in contrast to the volume-expansion group where P(z) was unaffected by the procedure. In conclusion, it seems that including measurement of the mean arterial pressure and pulse pressure with the PI adds valuable information about the circulatory status in this particular vasculature, regarding both 'basal' values and hemodynamic changes.

Journal Article↗
PubMed1994

Oxygenation of the human fetus as a function of hemoglobulin concentration.

We studied the relationships between fetal hemoglobin concentration, acid base status, and lactate concentration in umbilical venous and fetal heart blood in 157 fetuses affected by blood group incompatibility who had been exposed for 214 fetal blood sampling procedures (cordocentesis in 153 and intracardiac puncture in 61 cases). All blood samplings were obtained before fetal blood transfusions were administered. The results indicate that the human fetus can maintain a normal acid-base status until a 50% reduction of the hemoglobin concentration. A further reduction of hemoglobulin is associated with an accumulation of lactate both in umbilical venous and fetal heart blood. The partial oxygen tension and the oxygen saturation in umbilical venous blood remained virtually unchanged with decreasing hemoglobin concentration (r = -0.11, P = 0.21; r = 0.09, P = 0.31, respectively), whereas these parameters decreased significantly (r = 0.33, P = 0.02; r = 34, P = 0.02) in blood obtained from the fetal heart. The partial carbon dioxide tension of umbilical vein blood decreases significantly with a reduced hemoglobin concentration (r = 0.25 P = 0.008). We speculate that these alterations in acid-base status in umbilical vein and fetal heart blood reflect a circulatory transition from a high to a low cardiac output as the hemoglobin concentration decreases.

Acid-Base Equilibrium↗
PubMed1994

Ontogeny of insulin-like growth factor-binding protein-1, -2, and -3: quantitative measurements by radioimmunoassay in human fetal serum.

There is evidence for a role for IGF-I in the endocrine control of human fetal growth despite the low serum IGF-I concentrations. The formation in serum of binary complexes between IGF-I or -II and either of six IGF binding proteins (IGFBP-1 to -6) and, in particular, of long-lived ternary complexes between IGF-I or -II, IGFBP-3, and acid-labile subunit is thought to regulate IGF-I bioavailability by increasing its serum half-life. The present study assesses the bioavailability of circulating IGF-I in 19- to 35-wk gestation human fetuses in utero 1) by quantitative RIA measurements of IGF and IGFBP in serum and 2) by examining whether serum proteolysis of IGFBP-3 may further increase IGF-I bioavailability. Fetal serum concentrations of IGFBP-3, IGF-I, and IGF-II were low with marked or only modest increases with gestational age (p < 0.001, p < 0.005, and p < 0.05, respectively). The mean molar ratio between IGF-I plus -II and IGFBP-3 demonstrated a molar excess of IGF (50%) similar to that in adolescents but in contrast to the 1:1 molar ratio in adults. The median IGFBP-2 concentration was 3-fold elevated to a molar concentration similar to that of IGFBP-3 (adult serum displays 10-fold higher IGFBP-3 concentrations). The median serum IGFBP-1 concentration was not elevated as previously reported in newborns. IGFBP-3 protease activity was not increased in fetal serum, in contrast to pregnancy serum and amniotic fluid.(ABSTRACT TRUNCATED AT 250 WORDS)

Blotting, Western↗
PubMed1994

Establishment of a tissue bank for fetal stem cell transplantation.

STUDY OBJECTIVE: To analyse the yield of fetal liver tissue in first trimester abortions and to evaluate the number of nucleated cells obtained from each fetal liver during the sixth to twelfth week of gestation. DESIGN: Prospective descriptive study: LOCATION: University Hospital. MATERIAL: Women seeking abortion during a 12 month period 1992/1993. RESULTS: Out of 1271 women seeking abortion, 152 were asked whether they were willing to donate fetal tissue for fetal transplantation. Of these women, 105 (69%) accepted the proposal and underwent a modified low suction vacuum curettage. Fetal liver tissue was obtained in 61 (58%) of these procedures. The frequency at which tissue was retrieved was strongly related to gestational age and rose from 29% in week 6 to 79% in the tenth to twelfth week of gestation. The mean number of nucleated cells obtained from each fetal liver demonstrated a concomitant increase with gestational age, rising from 16 to 43 x 10(6) per liver during these weeks of gestation. Of the 61 cases in which fetal liver was obtained, four subjects were shown to be abnormal by laboratory analyses and 11 did not alter the mandatory follow-up appointment. This left 46 cases for use in the program of fetal to fetal transplantations. CONCLUSIONS: Most women seeking abortion seem to be in favor of the idea of fetal tissue donation for the treatment of other fetuses. The possibility of obtaining fetal liver tissue and the number of fetal stem cells retrieved are closely correlated to gestational age. A tissue bank appears to facilitate the operation of a fetal to fetal stem cell transplantation program.

Attitude to Health↗
PubMed1994

Lactate in fetal scalp blood and umbilical artery blood measured during normal labor with a test strip method.

A new test strip method was used to determine the lactate concentration in fetal scalp blood during normal labor. Sixty-six fetal scalp blood samples were collected at cervical dilatations between 4 cm and 10 cm. The mean lactate value was 1.7 +/- 0.8 mmol/l simultaneously (IS.D.) and the mean pH sampled simultaneously was 7.36 +/- 0.04 (IS.D.). The corresponding values for base deficit was 2.1 (+/- 1.9) and for pCO2 5.8 (+/- 0.8). No difference was seen in lactate concentrations or pH values in early compared to late first stage of labor. The mean lactate concentration in the umbilical artery immediately after delivery was 3.7 mmol/l +/- 1.2 (IS.D.). The method was easy to handle and gave the result within 60 seconds.

Female↗
PubMed1994

Autonomic cardiovascular control in normal and pre-eclamptic pregnancy.

BACKGROUND: Pre-eclampsia is regarded as a primary placental disorder, in which defect placentation causes endothelial and cardiovascular disturbances. Evidence of disturbed neural cardiovascular control in this condition has been suggested, as well as in other hypertensive diseases. The purpose of the present study was to non-invasively evaluate the sympathovagal balance during normal and pre-eclamptic pregnancy. METHODS: In twelve healthy pregnant women, thirteen pre-eclamptic women and ten nonpregnant controls, heart rate, blood pressure and breathing movements were registered and recorded on a tape recorder for off-line analysis. Variability in heart rate, blood pressure and breathing movements were computed by an autoregressive spectral analysis algorithm. Heart rate variability was quantitated as the area under the spectral curve, and Student's t-test was performed on logarithmic values. RESULTS: Heart rate variability contained two major components in power, a low frequency peak predominantly attributed to sympathetic tone, and a high frequency peak reflecting vagal tone. Women with pre-eclampsia were characterized by a significantly reduced high frequency peak compared to healthy pregnant (p = 0.03) and non-pregnant (p = 0.02) women. In the low frequency band there were no significant differences in power between the groups. Blood pressure variability did not differ between the groups. CONCLUSIONS: The present results indicate that pre-eclampsia is associated with decreased vagal control of the heart. Furthermore, the results indicate that pregnancy per se does not change sympatho-vagal balance.

Adult↗
PubMed1994

Conservative ambulatory management of prelabor rupture of the membranes at term in nulliparous women.

OBJECTIVE: To assess maternal and fetal outcome at conservative ambulatory care of nulliparous women at term with prelabor rupture of the membranes. METHODS: A prospective study of 176 women managed conservatively in an ambulatory setting (nonstress test and assessment of amniotic fluid index every second day). RESULTS: The median rupture of the membrane to delivery interval was 30 hours. Ninety per cent were delivered within 85 hours. The patients were divided into three groups according to the time period between rupture of membranes and delivery (under the 25th, 25th-75th and above the 75th centile). The maternal infectious morbidity (0, 6, 7% respectively), fetal distress (5, 18, 17% respectively) and instrumental delivery rate (5, 16, 16% respectively) tended to be increased in the upper three quartiles, without reaching a statistically significant level as analysed by chi 2-test. Nonstress test or evaluation of amniotic fluid index was not able to predict intrapartum fetal distress. In no case was there a delay in the management of any complication due to the ambulatory care. CONCLUSION: Awaiting spontaneous labor in nulliparous women with prelabor rupture of the membranes at term does not seem to be associated with any obvious advantage. If, however, a conservative attitude is implemented, the patients can preferably be treated on an ambulatory basis.

Adult↗
PubMed1994

Decreased ternary complex formation and predominance of a 29 kDa IGFBP-3 fragment in human fetal serum.

Insulin-like growth factor-I (IGF-I) has been proposed to be important in the endocrine control of fetal growth in humans, although serum IGF-I concentrations are 10-fold lower than during rapid pubertal growth. However, the bioavailability of IGF-I in fetal serum may be increased by changes in the specific IGF binding proteins (IGFBPs). We have recently suggested that the bioavailability of circulating IGF-I is increased in the human fetus due to the molar excess of IGF-I plus IGF-II relative to IGFBP-3 as well as the increased concentrations of IGFBP-2, which does not form a long-lived ternary complex. We have presently studied ternary complex formation between IGF, IGFBP-3, and acid labile subunit (ALS) to further assess if IGF-I bioavailability is increased in human fetal serum. In 19-35 week gestation fetal sera, a markedly decreased formation of the ternary complex was demonstrated by the general absence of IGFBP-3 (detected by Western immunoblotting) in the approximately 130-150 kDa ternary complex after neutral size chromatography. The predominant form of IGFBP-3 in fetal serum was a 29 kDa fragment, which, following deglycosylation by Endoglycosidase-F, was demonstrated to consist of a approximately 20 kDa protein core. Despite the predominance of the 29 kDa IGFBP-3 fragment, we have previously demonstrated that the IGFBP-3 protease activity is not increased in fetal serum, in contrast to pregnancy or non-insulin dependent diabetes mellitus (NIDDM) sera.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Immunological capacity of human fetal liver cells.

The aim of this study was to evaluate immunological characteristics of human fetal liver (FL) cells, fresh and cryopreserved, 7-12 weeks post-conception. With monoclonal antibodies, HLA-associated determinants were demonstrated on FL. Although serological HLA determination of A, B, C and class II antigens was not possible, genomic HLA class II typing using RFLP technique or PCR amplification with sequence-specific primers was feasible. MLC induced only minor responses. Exposure to standard mitogens and polyclonal B cell activators did not stimulate DNA synthesis or antibody production. ABO antigens were expressed and determined. The apparent low immunological capacity of FL cells may reduce the risk of rejection and graft-versus-host disease when such cells are used in transplantation.

Adult↗
PubMed1993

The minimum number of cardiac cycles necessary for calculation of renal blood flow velocity indices in pregnant and non-pregnant women.

In this study Doppler ultrasound was used to measure the blood flow velocity in the main and segmental renal arteries in 16 healthy non-pregnant women. There were no differences in blood flow indices between the right and left kidneys as well as between the main and segmental arteries. The variability of the indices in the main and segmental renal arteries in healthy non-pregnant and in the segmental renal artery in normal pregnant women (32-37 weeks of gestation) was investigated. The within-patient error standard deviations of ten cycles and two, and three to nine averaged cycles were compared. In non-pregnant women, values for the error standard deviation comparable with those obtained from ten cycles for the systolic/diastolic ratio and pulsatility index from both main and segmental arteries were obtained by averaging from five to six consecutive cycles, while the error standard deviation for the resistance index stabilized when averaging only two to four cycles. In pregnant women, the error standard deviations for both the systolic/diastolic ratio and pulsatility index reached quite stable values after three cycle had been averaged as did the error standard deviation for the resistance index. We speculate that this difference between non-pregnant and pregnant women is due to more favorable conditions for renal visualization and consequently higher quality Doppler signals during pregnancy. A knowledge about the number of cardiac cycles required for an accurate calculation of renal blood flow velocity indices may prevent time-consuming calculations and inaccurate conclusions.

Journal Article↗
PubMed1993

Effect of variations of heart rate within the normal range on renal artery Doppler indices in nonpregnant and pregnant women.

The effect of heart rate on Doppler indices in the renal artery was studied in 21 nonpregnant, 17 normal and 27 preeclamptic pregnant patients. The central hemodynamics was evaluated by Doppler ultrasound in all pregnant women. The study demonstrated no influence of heart rate on renal artery Doppler indices. Central hemodynamic parameters, such as cardiac output, stroke volume, mean arterial pressure and total systemic resistance did not change with increasing heart rate. We do not recommend any correction of the renal artery Doppler indices for heart rate in the range considered clinically normal (60 to 95 beats/min). Above or below this range further investigations are required to determine if corrections would be necessary.

Adult↗
PubMed1993

Hypoxanthine in fetal umbilical venous blood and amniotic fluid from pregnancies complicated by rhesus isoimmunization.

Concentrations of hypoxanthine (HX) was determined in umbilical venous blood and amniotic fluid obtained at 74 instances in 36 rhesus immunized patients before the onset of labor. HX concentrations were related to gestational age, concentrations of hemoglobin and lactate, pH, and partial oxygen pressure in umbilical venous blood. Multiple regression analysis revealed hemoglobin concentration to be the only variable that had any explanatory power to HX in amniotic fluid. No one of the studied variables gave any significant contribution to a regression model to explain HX in umbilical venous blood. We conclude that HX levels in umbilical venous blood and in amniotic fluid from rhesus immunized patients were not associated with fetal blood gases before the onset of labor.

Amniocentesis↗