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Biomedical subjects

M F Greene

Publications and source records attributed to M F Greene.

At least 55 records · Page 3Linked to original sources
PubMed1989

The prenatal sonographic features of Noonan's syndrome.

The sonographic findings in four infants with Noonan's syndrome are described. All four fetuses had cystic hygromata located laterally along the cervical spine and normal karyotypes. Three of the four pregnancies were complicated by polyhydramnios and those three fetuses had associated pleural effusions. One fetus developed frank hydrops and did not survive, a clinical course that appears to be part of the clinical spectrum of Noonan's syndrome. The diagnosis of Noonan's syndrome was given serious consideration prenatally based on the sonographic findings and normal karyotype and confirmed at birth in all four cases. Three of the infants survived.

Adult↗
PubMed1988

A physiological delay in human fetal hemoglobin switching is associated with specific globin DNA hypomethylation.

The human fetal-to-adult globin switch normally occurs on a fixed schedule, beginning at 32-34 weeks gestation, and recent studies have suggested an association between this developmental inactivation of the fetal (gamma) globin genes and the appearance of methylation within and around these genes. We have studied a population of infants in whom this switch does not occur before birth (infants of diabetic mothers, IDM) and examined the patterns of methylation surrounding their active gamma-globin genes, in comparison to the gamma-globin genes of age-matched controls who have switched their pattern of globin gene expression on schedule. All genomic DNA samples from infants with delays in the globin switch demonstrated extensive hypomethylation in the region of the gamma-globin genes, comparable to that found in the genomes of fetuses of less than 21 weeks gestation. DNA from the erythroid cells of infants of 32-40 weeks gestation had no detectable hypomethylation in the gamma-globin region. These findings support the concept that hypomethylation is an accurate developmental marker of globin gene switching, and suggest that globin gene expression in IDM may be arrested at an early preswitch stage.

Adult↗
PubMed1988

Management of isoimmunized pregnancy by use of intravascular techniques.

Twenty-two patients who had 23 pregnancies complicated by isoimmunization were managed by the use of intravascular methods on an outpatient basis. Nine patients underwent 30 percutaneous fetal blood sampling procedures to determine fetal blood type or hematocrit, without complication. Thirteen patients underwent 45 intrauterine fetal transfusions via the umbilical vessels and 16 intraperitoneal fetal transfusions. The overall survival rate in this series was 85.7%. Survival among fetuses that were hydropic at initial evaluation was 83.3%. The procedure-related perinatal mortality rate for intravascular intrauterine transfusions was 2.2%. Knowledge of fetal blood type and hematocrit allowed treatment individualized to the specific needs of each patient. In particular, the ability to transfuse blood directly into the vascular system of the hydropic fetus proved to be lifesaving in those patients.

Blood Grouping and Crossmatching↗
PubMed1988

Fetal abnormalities: diagnosis or treatment with percutaneous umbilical blood sampling under continuous US guidance.

Percutaneous umbilical blood sampling has become an important tool in maternal-fetal medicine and allows direct access to fetal blood. In 52 patients, 100 successful consecutive blood sampling procedures were done for a variety of indications, including 20 intravascular intrauterine fetal transfusions for isoimmune disease. Indications, technique, and complications in this series of percutaneous umbilical blood sampling procedures are described.

Blood Specimen Collection↗
PubMed1988

Early amniocentesis for prenatal cytogenetic evaluation.

Early amniocentesis at 11-14 weeks gestation was evaluated in 100 consecutive patients to see how this technique compares with later amniocentesis. There were no complications as a consequence of the procedure or related pregnancy losses of chromosomally normal fetuses. Samples obtained from three (3%) patients showed insufficient cell growth; two of these patients elected a repeat procedure, which yielded a normal karyotype in each case. There were five abnormal karyotypes, one of which was a culture artifact; in the latter case, repeat amniocentesis at 15 weeks yielded a normal result. Of the 95 pregnancies with normal karyotypes, 94 were progressing normally at follow-up, and one patient elected pregnancy termination because of maternal indications. It appears that early amniocentesis may be an attractive alternative to traditional amniocentesis, in that it provides results at an earlier gestational age and may avoid certain disadvantages of chorionic villus sampling.

Amniocentesis↗
PubMed1987

Butryic acid analogues augment gamma globin gene expression in neonatal erythroid progenitors.

The gamma----beta globin gene switch in humans is normally on a set developmental clock but is delayed in infants of diabetic mothers. We cultured cord blood erythroid progenitors and assayed globin produced in the presence and absence of metabolites that are elevated in such infants. Analogues of butyric acid at supranormal concentrations significantly augmented gamma and inhibited beta globin expression. The uptake of alpha-amino-n-butyric acid into colony-derived erythroblasts was increased in the presence of supranormal insulin. These findings suggest that elevated levels of alpha-amino-n-butyric acid and insulin in the developing fetus delay the globin switch and may offer potential for augmenting gamma globin expression in the beta globin chain diseases.

Butyrates↗
PubMed1987

Reliable criteria for the prenatal sonographic diagnosis of alobar holoprosencephaly.

A series of 10 consecutive cases of alobar holoprosencephaly is described. The disorder was diagnosed prenatally by ultrasound according to two criteria: a large central fluid collection in the fetal head, with no visible midline structures but with the presence of a mantle around the fluid collection and fusion of the thalami and corpus striatum, and sonographic abnormalities of the face, including hypotelorism, central clefts, facial asymmetry, and abnormal orbits.

Brain↗
PubMed1987

Acute fetal distress associated with percutaneous umbilical blood sampling.

Percutaneous umbilical blood sampling is emerging as an important procedure in the armamentarium of the obstetrician involved with prenatal diagnosis. It has apparent low morbidity and can be accomplished with relative ease by the experienced operator. We report a series of 42 successful percutaneous umbilical blood sampling procedures in 22 patients and describe the indications and gestational ages of the fetuses undergoing the blood-sampling procedures. Nine of the procedures involved intravascular transfusions. In one of our 42 cases, acute fetal distress developed in a manner similar to that of a previously reported case that was likewise associated with a compromised fetus and ended in death. Because of prompt and immediate delivery, the infant described in this series survived and, although this procedure appears to be relatively safe in experienced hands, it is imperative that the associated complications be duly recorded.

Blood Specimen Collection↗
PubMed1986

Ultrasonographic fetal surveillance in the management of the isoimmunized pregnancy.

During the past 20 years the management of pregnancies involving rhesus sensitization has been based on determinations of the optical density of amniotic fluid as an index of the bilirubin concentration and the degree of hemolysis. High values have dictated intervention in the form of delivery or intrauterine transfusion, depending on the gestational age. Since 1982 intensive surveillance with ultrasound imaging and electronic monitoring of the fetal heart rate have become useful in decisions about the timing of intervention. Using these tools, we followed 11 fetuses who would previously have been treated by multiple intrauterine transfusions or early delivery, for 8 to 63 days without treatment. All were born alive, in good condition and without hydrops, at gestational ages of 30.5 to 36.0 weeks. The lengths of stay for the neonates ranged from 8 to 48 days, and all were discharged alive. We conclude that rhesus sensitization in a select group of fetuses, who according to former standards would have been candidates for earlier delivery or intrauterine transfusion, can be managed expectantly for longer periods by careful observation with modern techniques of surveillance.

Cesarean Section↗
PubMed1986

Use of a small-gauge needle for intrauterine fetal transfusions.

Intraperitoneal intrauterine fetal transfusions have generally been performed with large-gauge Tuohy needles, which increase the risk of traumatic fetal complications. We feel that this technique can be improved by use of a small-gauge needle and continuous ultrasound visualization. A series of 20 transfusions is presented.

Blood Transfusion, Intrauterine↗
PubMed1986

Complexities of intraventricular abnormalities.

We identified 59 fetuses and infants with intracranial anomalies over 5 1/2 years. The cases represented heterogeneous diagnostic groups: hydrocephalus with a neural tube defect, hydrocephalus with a specified structural anomaly, hydrocephalus of unspecified or miscellaneous cause, holoprosencephaly, and hydranencephaly. One or more major nonneural tube malformations were present in 19 of 54 cases. Eight of 32 cases had a significant chromosomal abnormality. The rate of survival was poor: 13 of 59 pregnancies were terminated electively before 24 weeks gestation, 10 of 59 infants were stillborn, and 16 of the remaining 38 liveborn infants have died since birth. A prenatal ultrasonographic diagnosis was made in the majority of cases (50 of 59). Diagnostic accuracy of prenatal ultrasound examinations ranged from a high of 90% for hydrocephalus to 33% for holoprosencephaly and hydranencephaly, and a low of 22% for the presence of extracranial malformations. Eleven cases in this series could have been considered potential candidates for in utero treatment of ventriculomegaly; this therapy would have been ineffective or inappropriate in eight of these. We recommend that each case undergo thorough diagnostic evaluation, including ultrasound examination and chromosome studies; that parents be informed of the high frequency of associated anomalies, the poor prognosis regarding survival, and the current limitations of ultrasound diagnostic accuracy; and that in utero treatment of fetal ventriculomegaly seems inadvisable at the present time.

Abortion, Induced↗
PubMed1986

Insulin stimulates cord blood erythroid progenitor growth: evidence for an aetiological role in neonatal polycythaemia.

Polycythaemia in the neonate is a serious pathologic entity which occurs particularly in infants of diabetic mothers (IDM) and small-for-gestational age (SGA) infants. Both of these conditions are associated with fetal hyperinsulinaemia. Cultures of cord blood mononuclear cells from polycythaemic IDM showed increased growth of late erythroid progenitor colonies, compared to cord blood mononuclear cells from non-polycythaemic infants, reflecting a possible expansion of this progenitor population in the polycythaemic fetus. No changes were observed in early erythroid progenitor populations. Biosynthetic human insulin at physiological levels characteristic of IDM stimulated growth in culture of late erythroid progenitors in cord blood from premature, term and IDM infants. Three out of five polycythaemic infants had elevated cord blood plasma levels of insulin C-peptide at birth, whereas no infant with a haematocrit of less than 65% had high insulin C-peptide measurements. These data suggest that the polycythaemia noted in infants of diabetic mothers may be secondary, in large part, to a stimulatory effect on erythroid progenitor growth by the hyperinsulinaemic environment in which they develop in utero.

C-Peptide↗
PubMed1986

Congenital diaphragmatic hernia: US diagnosis prior to 22 weeks gestation.

Two cases of congenital diaphragmatic hernia diagnosed sonographically in utero at 18 and 21 weeks gestation are described. In previous reports, this diagnosis has been made at 28 weeks or more. Recognition of this severe abnormality in the second trimester affords two options. The parents can interrupt the pregnancy, or a surgical attempt at correction in utero may be possible and be early enough to allow adequate lung development to take place.

Adult↗
PubMed1986

Abnormal facial features and extremities in human trisomy syndromes: prenatal US appearance.

Twelve cases of fetal trisomy syndromes are reported in which prenatal sonographic findings were highly suggestive of the chromosomal abnormality. The abnormal appearance on the sonogram led to karyotype studies in ten fetuses and to appropriate obstetrical management. The sonographic abnormalities pertained to the extremities and face of the fetus.

Chromosome Aberrations↗
PubMed1986

Femur length/abdominal circumference ratio. Poor predictor of macrosomic fetuses in diabetic mothers.

Antenatal diagnosis of fetal macrosomia can affect the management of diabetic mothers. Because the sonographically determined femur length/abdominal circumference (FL/AC) ratio has been shown to differ in macrosomic and non-macrosomic fetuses (in a population containing few diabetics), its value in establishing the diagnosis of macrosomia was examined. The results indicate that the FL/AC ratio differs in non-macrosomic (20.4 +/- 1.6) and macrosomic (19.5 +/- 1.4) fetuses of diabetic mothers, but there is considerable overlap. For no cutoff value is there a high sensitivity and high specificity. The positive predictive value is 36-43 per cent (depending on the cutoff), only slightly greater than the prevalence (26 per cent in the study population). The authors conclude that the FL/AC ratio is not useful in predicting macrosomia among diabetic mothers.

Abdomen↗