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Biomedical subjects

L Löfberg

Publications and source records attributed to L Löfberg.

23 records · Page 2Linked to original sources
PubMed1982

Transfer of tissue cells to the fetus.

Several diseases of the fetus can be diagnosed prenatally. Some of them are due to insufficient production of a specific substance. It was therefore thought that, with the aid of fetoscopy, it might be possible to supply such an affected fetus with cells capable of producing the deficient substance. To ascertain whether tissue cells injected into the feto-placental circulation can pass through the microcapillaries of the placenta as early as in the second trimester, 125I-labelled cells of fetal liver were injected into an umbilical vessel ex utero after therapeutic abortion by hysterotomy. The distribution pattern of the radioactivity indicated that donor cells passed through the microcapillaries of the placenta and reached the target, i.e., the liver. In each experiment, the activity in the liver was higher than that in other organs studied. The activity in the brain and in the lungs was low. Transfer of tissue cells from a normal fetus to the circulation of an affected fetus in utero thus seems feasible. Permanent colonization of such cells would be facilitated by the fact that the donor as well as the recipient are fetuses of the second trimester and thus immunologically immature.

Blood↗
PubMed1981

Prenatal diagnosis of alpha 1-antitrypsin deficiency by analysis of fetal blood obtained at fetoscopy.

Two women had each borne a child who had alpha 1-antitrypsin (alpha 1AT) deficiency Pi ZZ and who developed liver cirrhosis. In subsequent pregnancies, the women requested prenatal diagnosis. Samples of blood from the two fetuses were obtained at fetoscopy. In a control group of five Pi MM fetuses aborted by hysterotomy, the mean alpha 1AT level was 0.73 g/liter. Of the two fetuses at risk, one had an alpha 1AT concentration calculated as 0.60 g/liter, i.e., within the Pi MZ range. The electrofocusing pattern indicated a heterozygous Pi MZ phenotype which was confirmed at birth. The other fetus at risk had a markedly decreased concentration of alpha 1AT, 0.06 g/liter. Electrofocusing showed a homozygous Pi ZZ phenotype. Analysis of blood from the abortus confirmed these findings and thus the diagnosis of alpha 1AT deficiency. Speculation Most of the alpha 1-antitrypsin in amniotic fluid is derived from the mother. It therefore appears that the only possible way of making a prenatal diagnosis of alpha 1-antitrypsin deficiency is by examination of blood from the fetus. One fetus examined in the present study had an abnormal Z-pattern. This abnormality may indicate a disturbance of fetal liver function already in utero.

Female↗
PubMed1980

Prenatal diagnosis of hemophilia B by an immunoradiometric assay of factor IX.

An immunoradiometric assay of factor IX was developed based on homologous antibodies that arose in a hemophilic patient. With this assay, 11 of 12 patients with severe hemophilia B had factor IX antigen levels below 1 U/dl and 6 patients with mild hemophilia B had various levels. Factor IX antigen in 8 fetuses (16th-20th gestational week) aborted for therapeutic reasons ranged from 1.8 to 10.0 U/dl. Six amniotic fluids contained 0.28-1.2 U/dl factor IX antigen. Using the immunoradiometric assay, we could diagnose hemophilia B prenatally in one fetus at risk. No factor IX antigen (< 0.2 U/dl) was detectable in the fetoscopic sample. After termination of the pregnancy, analysis of blood from the abortus confirmed the diagnosis of severe hemophilia B. We conclude that very sensitive immunologic assays, such as the one described here, will prove useful in prenatal diagnosis of severe hemophilia B, since determination of factor IX activity in fetoscopic samples is unrealiable because of possible contamination with thromboplastic material.

Dose-Response Relationship, Immunologic↗
PubMed1979

Fetoscopy.

A brief report is given on fetal blood sampling by fetoscopy in three fetuses at risk for severe congenital bleeding disorder; hemophilia A in two cases, von Willebrand's disease in one. Published reports on complications of fetoscopy are reviewed. Out of all together about one hundred pregnancies that have been allowed to continue after fetoscopy, five ended in miscarriage. No other serious complication has been reported.

Abortion, Spontaneous↗