Biomedical subjects

N Callan

Publications and source records attributed to N Callan.

4 recordsLinked to original sources

PubMed1997

Indicators of platelet turnover in thrombocytopenic infants.

Glycocalicin has been found to be a marker of increased platelet turnover, while interleukin-6 may be increased in response to thrombocytopenia. We used these markers to study the pathophysiology of thrombocytopenia in newborn infants. Cord blood platelet counts were obtained from 499 infants. Thrombocytopenic infants (< 100,000/mm3) and a control group had ELISA assays for interleukin-6 and glycocalicin performed. The mean levels of glycocalicin and interleukin-6 were elevated in cord blood of thrombocytopaenic infants. Infants with intrauterine growth restriction and thrombocytopaenia had no detectable glycocalicin in their plasma, despite elevated levels of interleukin-6. This probably reflects impaired thrombopoiesis in these infants.

Blood Platelets↗

PubMed1992

Chorionic villus sampling for fetal Rh typing: clinical implications.

OBJECTIVE: The prenatal Rh typing of red blood cells obtained by chorionic villus sampling was performed with an immune rosette technique. STUDY DESIGN: Ten Rh-negative pregnant women undergoing chorionic villus sampling at 9 to 11 weeks' gestation were studied at a large referral hospital. RESULTS: Accurate Rh phenotyping may be done on red blood cells obtained from chorionic villi weighing 2 to 8 mg. The preparations were shown to be greater than 90% fetal in origin as demonstrated by radial immunodiffusion quantitation of fetal hemoglobin-containing cells. Of the 10 fetuses typed in the first trimester nine of the pregnancies were carried to term. In all cases typing of red blood cells confirmed the antenatal fetal red cell typing. CONCLUSIONS: This study shows that antenatal Rh phenotyping may be performed as early as 9 to 11 weeks' gestation. This technique may be used in the management of pregnancies complicated by Rh incompatibility.

Blood Grouping and Crossmatching↗

PubMed1988

Obstetric management of a fetus with nonlethal osteogenesis imperfecta.

Osteogenesis imperfecta is the common term for a heterogeneous group of heritable disorders of connective tissue with lethal and nonlethal forms. Prenatal diagnosis presents difficult medical and ethical issues. Of concern are the following: 1) the certainty of diagnosis, 2) the severity of disease, 3) the prognosis for survival and ambulation, and 4) the appropriate mode of delivery. A case of nonlethal fetal osteogenesis imperfecta managed by vaginal delivery is discussed.

Adult↗

PubMedDate not supplied

Development of an index of maternal transport.

The authors used a decision-analytic approach to develop a Maternal Transport Index (MTI) from ACOG guidelines for maternal transport. Data were obtained from three questionnaires administered to five perinatologists, practicing in facilities with various casemixes. Each questionnaire was based on a given level of hospital and contained scenarios describing indications for maternal transport. The MTIs, ratios of the logs of the proportions with given outcomes in Level III hospitals relative to Level I (or II) hospitals, ranged from 1.0 to 26.3 for newborn outcomes. They were greater for Level I hospitals (than Level II) and when newborn outcomes included severe disability as well as death. Within gestational age categories, the MTI was generally greatest for active preterm labor and, within complication categories, for 24-26 or 27-31 weeks' gestation. It was large for maternal outcomes only for two rare acute medical conditions. The MTI has potential use in setting priorities for maternal transport.

Adult↗