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Biomedical subjects

S Ek

Publications and source records attributed to S Ek.

At least 19 recordsLinked to original sources
PubMed2001

[Twin-twin transfusion syndrome--front line in fetal medicine].

Twin-twin transfusion develops in 10-20% of monochorionic twin pregnancies. As far as we know the underlying disturbance is an unbalanced anastomosis between the two fetuses on the placental surface. Without treatment mortality is as high as 80% if diagnosed before viability. One of this article's authors spent two months in Hamburg at the "Allgemeine Krankenhaus", Barmbeck in Germany and describes the technique used there to coagulate these anastomoses via fetoscope. The outcome seems very promising with overall survival of 80% using this method. In the article pathogenesis and alternative treatments are also discussed.

Female↗
PubMed2001

[Twin-twin transfusion syndrome--front line in fetal medicine].

Twin-twin transfusion develops in 10-20% of monochorionic twin pregnancies. As far as we know the underlying disturbance is an unbalanced anastomosis between the two fetuses on the placental surface. Without treatment mortality is as high as 80% if diagnosed before viability. One of this article's authors spent two months in Hamburg at the 'Allgemeine Krankenhaus', Barmbeck in Germany and describes the technique used there to coagulate these anastomoses via fetoscope. The outcome seems very promising with overall survival of 80% using this method. In the article pathogenesis and alternative treatments are also discussed.

Female↗
PubMed1998

Screening for fetal growth restriction: a mathematical model of the effect of time interval and ultrasound error.

OBJECTIVE: We estimated the effect of ultrasound error and time interval between examinations on the false-positive rate for detecting fetal growth restriction (FGR). METHODS: Using published growth curves for the fetal abdominal circumference and a coefficient of variation for ultrasound error of 5%, computer simulation was used to estimate false-positive rates in relation to the time interval between ultrasound examinations. Growth restriction was diagnosed when there was no apparent growth in fetal abdominal circumference between two consecutive examinations. In separate studies, the false-positive rate was plotted against gestational age at the first ultrasound examination. RESULTS: There was a dramatic increase in false-positive rates as the time interval between examinations was reduced. When the initial scan was performed at 32 weeks, the false-positive rate increased from 3.2% for an interval of 4 weeks to 30.8% for an interval of 1 week. At a 2-week interval, the error was 16.9%. There was a significant increase in the false-positive rate as the gestational age at the initial ultrasound was increased. At 28 weeks, the false-positive rate with a 2-week interval was 11.8%, increasing to 24.1% at 38 weeks. By varying the coefficient of variation of the ultrasound error, the false-positive rate increased from 0.8% at an error of 2% to 31.9% at an error of 10%. CONCLUSION: Ultrasound scanning at 2-week intervals is associated with false-positive rates for growth restriction in excess of 10%, increasing to much higher rates late in the third trimester. Improved screening performance should be attainable by increasing the interval between scans and reducing measurement errors.

Anthropometry↗
PubMed1998

Lactate compared with pH analysis at fetal scalp blood sampling: a prospective randomised study.

OBJECTIVE: Fetal scalp blood sampling is a widely used method for assessing fetal condition in the event of ominous fetal heart rate patterns. The purpose of this randomised trial was to compare the value of fetal scalp blood lactate and pH management in cases of abnormal intrapartum fetal heart rate tracings. METHODS: Of 341 cases of ominous fetal heart rate patterns, 169 were randomly assigned to pH analysis, and 172 to lactate measurements. Lactate was measured using a lactate card requiring 5 microL of blood and yielding the result within 60 seconds. pH analysis was performed with an ABL 510 acid-base analyser requiring 35 microL of blood and yielding the results within 47 seconds. RESULTS: Unsuccessful fetal blood sampling procedures (no result or an unreliable result) occurred significantly more often in the pH subgroup than in the lactate subgroup (OR 16.1 with 95% CI 5.8-44.7). In the pH subgroup the failure rate was inversely related to the degree of cervical dilatation. Compared with the pH subgroup, the lactate subgroup was characterised by fewer fetal scalp incisions per blood sampling attempt (median 1.0 [interquartile range (IQR) 1-1] vs 2.0 [IQR 1-2]), and significantly less time required for the sampling procedure (median 120 s [IQR 90-147] vs 230 s [IQR 180-300]). The groups did not differ in mode of delivery, neonatal outcome and umbilical artery acid-base balance and lactate levels. CONCLUSION: This trial showed the levels of lactate and pH in fetal scalp blood to be comparable in predicting perinatal outcome, but the procedure to measuring lactate was more successful than that for pH. Owing to its simplicity of performance, lactate analysis is an attractive alternative for intrapartum fetal monitoring.

Female↗
PubMed1998

Enlargement of cisterna magna as an indicator of chromosomal abnormalities in a low-risk Asian population.

AIMS: The aims of this study was to invent the prevalence of cisterna magna (CM) enlargement in a low-risk population and relate this to chromosomal abnormalities and initial delivery outcome. STUDY DESIGN: 11,145 patients having routine ultrasound scan at 21st week of pregnancy were screened for abnormalities. Cases with CM enlargement were traced and outcome retrieved either from case notes or from the patients. RESULTS: In our low-risk population six fetuses were found to have CM enlargement. Only one had a chromosomal abnormality, 47XY + 18, and this fetus also presented with other malformations. Four were healthy at birth and one, also with other malformations, is showing signs of mental retardation. All cases were male. CONCLUSION: Isolated CM enlargement does not seems to be an indicator for chromosomal abnormalities, especially if the fetus is a male. Still, it should alert the examiner of the possibility of other malformations, which may be of importance.

Adult↗
PubMed1997

Tissue distribution of transplanted fetal liver cells in the human fetal recipient.

OBJECTIVE: Our purpose was to study the tissue distribution and concentrations of transplanted fetal liver cells in the human fetus. STUDY DESIGN: Radiolabeled indium 111 fetal liver cells were injected in vivo under ultrasonographic guidance into 10 normal fetuses (13 to 17 weeks of gestation) before a prostaglandin abortion. Six fetuses were injected intraperitoneally and four intracardially. Another two fetuses serving as controls were injected with indium-labeled maternal plasma. The fetuses were all alive, at least until 6 hours before expulsion. After expulsion the fetuses were dissected, and radioactivity was measured in various fetal tissues. Results for each tissue were expressed as percentages of the total injected dose. RESULTS: Significantly greater uptake of fetal liver cells in the liver, spleen, thymus, kidney, lung, and placenta was obtained with intracardiac than with intraperitoneal injection. Skeletal uptake did not differ in relation to mode of administration. With intracardiac injection uptake was greater in such parenchymal organs as the liver, spleen, and thymus (4.9%, 4.0%, and 3.9%, respectively). Uptake in the rib, clavicle, humerus, and sternum was 2.7%, 1.8%, 2.1%, and 1.1%, respectively. Placental uptake was 0.1%. The intracardiac route yielded a higher concentration of cells in different fetal organs than did injection of only radiolabeled maternal plasma, suggesting an active uptake of cells in different fetal hematopoietic organs. CONCLUSION: The mode of administration of fetal liver cells seems to be a major determinant of donor cell concentration in the transplanted human fetus and may be a significant determinant of the rate of successful engraftment.

Cell Movement↗
PubMed1997

Influence of ingesting a solution of branched-chain amino acids on perceived exertion during exercise.

On two occasions, seven male endurance-trained cyclists performed exhaustive exercise on a cycle ergometer in the morning after they had performed a bout of exercise the preceding evening in an attempt to lower the muscle glycogen stores. The subjects exercised at a work rate corresponding to approximately 70% of their maximal oxygen uptake for 60 min, followed by another 20 min of maximal exercise. During exercise the subjects were given either a solution of branched-chain amino acids (BCAAs) or flavoured water (placebo). Every 10 min during exercise the subjects rated their perceived exertion and mental fatigue on two different Borg scales. During the 60 min exercise at a given work rate the subjects ratings of perceived exertion when they were given BCAAs were 7% lower, and their ratings of mental fatigue were 15% lower than when they were given placebo. In addition, the performance in the colour task of Stroops Colour Word Test performed after exercise was improved when BCAAs had been ingested during exercise, compared with the results from the placebo trial. There was no difference in the physical performance between the two trials measured as the amount of work done during the last 20 min of exercise when the subjects performed at their maximum. The plasma concentration ratio of free tryptophan/BCAAs, which increased by 45% during exercise and by 150% 5 min after exercise in the placebo trial, remained unchanged or even decreased when BCAAs were ingested.

Adult↗
PubMed1996

Lack of evidence of permanent engraftment after in utero fetal stem cell transplantation in congenital hemoglobinopathies.

The use of fetal hematopoietic stem cells for in utero transplantation to create permanent hematochimerism represents a new concept in fetal therapy. In one fetus with alpha-thalassemia, one with sickle cell anemia, and one with beta-thalassemia, we have transplanted fetal liver cells obtained from legal abortions in gestational weeks 6-11. The fetus with alpha-thalassemia was transplanted twice during pregnancy, in the 15th (20.4 x 10(8) cells/kg) and in the 31st weeks of gestation (1.2 x 10(8) cells/kg), and is now two years of age. One fetus with sickle cell anemia received its transplant in the 13th week of gestation (16.7 x 10(8) cells/kg), and is now one year old. The fetus with beta-thalassemia was transplanted in 18th week (8.6 x 10(8) cells/kg), and is now three months old. Engraftment was evaluated by chromosomal analysis (sex chromosomes), red cell phenotyping, HLA class I and II typing, and PCR (polymerase chain reaction) for Y chromosome-specific sequences and DNA polymorphisms in cord and peripheral blood. The children with alpha- and beta-thalassemia underwent bone marrow aspirations at 3 and 7 months of age, respectively. In neither of these cases were we able to detect convincing evidence of stem cell engraftment. Thus, the administration of fetal stem cells to fetal recipients after the 12th week of gestation did not result in permanent hematochimerism. It remains to be determined whether the engraftment process can be promoted by earlier transplantations and/or higher cell doses.

Adult↗
PubMed1996

In utero haematopoietic stem cell transplantation: current perspectives and future potential.

In utero transplantation (IUT) of haematopoietic cells is a new therapeutic option for families with increased risk of having a child with an inherited disorder. Immunological naiveté and the rapidly expanding haematopoietic system in the first trimester human fetus, make therapeutic intervention by IUT a real possibility for those disorders which can be diagnosed early in gestation. Fewer cells are required than in postnatal BMT and therapy can be offered before the pathological sequelae of a disorder become manifested. However, only a few cases of IUT have been performed in humans and it is imperative that consensus is reached quickly on issues such as cell numbers/cell types so that the benefits of this approach to treatment can be realised. This review presents the current status of IUT, the cases thus far recorded and offers a prospective view of developments in this rapidly expanding area.

Female↗
PubMed1995

Cytokines in fetal blood and amniotic fluid in Rh-immunized pregnancies.

OBJECTIVE: To determine fetal serum and amniotic fluid (AF) levels of interleukin (IL)-3, IL-6, granulocyte-macrophage colony-stimulating factor, stem cell factor, and erythropoietin, and to explore the relationship between cytokines and hemoglobin concentration, white blood cell count (WBC), and platelet count in fetuses affected by Rh immunization. METHODS: Thirty-four consecutive Rh-immunized patients in gestational weeks 19-33 were included. All patients were investigated by funipuncture and 13 by amniocentesis. The levels of IL-3, IL-6, granulocyte-macrophage colony-stimulating factor, stem cell factor, and erythropoietin were estimated using commercially available immunoassays. RESULTS: There was a significant correlation between erythropoietin concentrations in fetal serum and AF (r = 0.54, P < .05), whereas none of the other cytokines showed a positive correlation between these two compartments. Fetal serum contained higher concentrations of IL-3, granulocyte-macrophage colony-stimulating factor, stem cell factor, and erythropoietin compared with AF. In contrast, the IL-6 level was significantly higher in AF compared with fetal serum (P = .002). Erythropoietin and IL-3 levels were both negatively correlated with fetal hemoglobin concentrations (r = -0.75, P = .02, and r = -0.67, P = .045). The fetal WBC correlated significantly with the fetal serum concentration of granulocyte-macrophage colony-stimulating factor (r = 0.38, P = .04). CONCLUSION: Human fetuses with anemia due to erythrocyte immunization exhibit an increased production of erythropoietin and IL-3. Other studied cytokines (such as stem cell factor, granulocyte-macrophage colony-stimulating factor, and IL-6) did not correlate with the degree of fetal anemia. Among the studied cytokines, only erythropoietin showed a positive correlation between fetal serum and AF.

Amniotic Fluid↗
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

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 relationships between personality traits and plasma gastrin, cholecystokinin, somatostatin, insulin, and oxytocin levels in healthy women.

In earlier studies performed on a group of women with gastrointestinal symptoms, significant positive correlations between the gastrointestinal hormone gastrin and anxiety, and a negative correlation with socialization were obtained. These and other relationships were tested on 33 healthy women. A comprehensive and concise statistical model was used for the analysis of correlations between, on one hand, the levels of oxytocin and the gastrointestinal hormones gastrin, cholecystokinin, somatostatin and insulin, and, on the other hand, personality traits. Almost all explained variance of the hormone levels could be referred to three personality trait factors, Anxiety, Aggressive non-conformity, and Detachment. The statistical explanation of the gastrin level variance was most successful, the three personality trait factors explaining 48% of this variance. Gastrin "increased" Anxiety while reducing Aggressive non-conformity and Detachment. A similar pattern for insulin was also reliable. Considering general trends, the negative correlations between all hormones and Detachment are interesting. Present data suggest that there is a psychoendocrinological antithesis to the fight-flight individual, characterized by high activity in the sympathoadrenal system: these contrasting persons, with high levels of the gastrointestinal hormones gastrin and insulin, tend to be warm and caring and non-aggressive--but often not free from anxiety. We do not think that the demonstrated associations between hormone levels and personality traits implicate a direct causal relationship. They rather may mirror the activity of centrally acting or hypothalamic control systems which influence both behavioural and endocrine profiles.

Adult↗
PubMed1993

Effects of cryopreservation on subsets of fetal liver cells.

Human fetal livers from 6 to 13 weeks postconception were analysed before and after cryopreservation. The percentages of cell subsets, detected by MoAbs, did not change significantly after cryopreservation. Compared with BM, fetal liver contained significantly smaller subsets of cells identified by MoAbs, with two exceptions. Fetal liver contained a mean of 47% M5 positive cells versus 31% in BM, and there was no difference in the numbers of CD34+ cells. The colony-forming capacity was studied: 53 colonies grew from 10(5) cells from fresh fetal liver compared with 51 colonies from cryopreserved cells. For fresh BM the corresponding value was 88 per 10(5) cells. Incubation time for fetal stem cells was 17-18 days while the corresponding time for BM cells was 8-10 days.

Antigens, CD↗
PubMed1993

Cryopreservation of fetal stem cells.

Fetal liver cells may be transplanted, in utero, to treat disorders affecting the hematopoietic system. Conventional immunological methods were employed to determine whether pooled cryopreserved cells could be a suitable basis for a tissue bank. We found that cryopreservation did not adversely change the population, viability or immunological capacity of human fetal liver cells and therefore, pooled and cryopreserved fetal stem cells may be suitable for transplantation.

Cryopreservation↗