Biomedical subjects

M J Mahoney

Publications and source records attributed to M J Mahoney.

At least 109 records · Page 6Linked to original sources

PubMed1984

When is termination of pregnancy during the third trimester morally justifiable?

The question whether to terminate pregnancy during the third trimester involves a moral conflict. We argue that such termination is morally justifiable if two conditions are fulfilled: first, that the fetus is afflicted with a condition that is either incompatible with postnatal survival for more than a few weeks or characterized by the total or virtual absence of cognitive function; and second, that highly reliable diagnostic procedures are available for determining prenatally that the fetus fulfills either of the two parts of the first condition. At present, one entity, anencephaly, clearly fulfills both conditions. We studied 10 cases involving fetuses with sonographically diagnosed anencephaly that were aborted during the third trimester. We also examined other fetal disorders and conclude that they do not clearly fulfill our two conditions for the justifiable termination of pregnancy in the third trimester.

Abortion, Induced↗

PubMed1984

Brief clinical report: lethal multiple pterygium syndrome in an 18-week fetus with hydrops.

We present the case of an 18-week abortus with lethal multiple pterygium syndrome and hydrops. Radiographic and anatomic study showed none of the bony abnormalities reported in live-born children with multiple pterygium syndrome. The pathogenesis of the hydrops was not apparent. The findings of cleft palate, pulmonary hypoplasia, muscular atrophy, gracile thoracic bones, and fetal death are typical of the lethal variant.

Abnormalities, Multiple↗

PubMed1984

Cytogenetic diagnosis using midtrimester fetal blood samples: application to suspected mosaicism and other diagnostic problems.

Cytogenetic studies on fetal blood cells obtained at 18-25 weeks gestation have provided information for decision making in 25 cases identified as being at high risk of having an abnormal fetus. In particular, in the 21 cases studied to consider the possibility of true mosaicism, confirmation in fetal blood was obtained in three, one of which presented as a pseudomosaic on the original amniotic fluid cell study. Fetal blood was also informative in two cases (one positive and the other negative) in which a diagnosis of the fragile X syndrome was being considered. Furthermore, when high risk pregnancies presented late in gestation (21-24 weeks), these methods allowed for a rapid cytogenetic diagnosis. The procedure has proved useful in most of these cases since the couples involved had indicated that they would probably have terminated the pregnancy without the reassurance of normal fetal lymphocyte studies. Since the technique carries a much higher risk of pregnancy loss than does amniocentesis, its use should only be considered when there are compelling indications.

Cells, Cultured↗

PubMed1984

Treatment of the cbl B form of methylmalonic acidaemia with adenosylcobalamin.

A 30-month-old girl was found to have the cbl B mutant form of methylmalonic aciduria by complementation analysis of fibroblasts. She was unresponsive to hydroxycobalamin and was treated with intramuscular adenosylcobalamin (AdoCbl), the deficient coenzyme, at a dose of 1 mg/24h during a period of clinical stability. Serum cobalamin increased from 770 to 54 200 pg/ml. Mean urinary methylmalonic acid excretion was 409 mg/24 h prior to therapy. There was a transient fall in methylmalonic acid excretion during the first 5 days of therapy (range 167-245 mg/24h) followed by a rise in excretion toward pretreatment levels (range 317-485 mg/24h) during the second week of AdoCbl treatment. There was no change in plasma ammonia, glycine or serum bicarbonate level. We interpret the failure of this child to have a sustained and clinically significant response to AdoCbl as indicating that AdoCbl did not reach or enter the mitochondria intact, or in some other way was unavailable as a coenzyme for the methylmalonyl CoA mutase apoenzyme.

Amino Acid Metabolism, Inborn Errors↗

PubMed1984

The Master Questionnaire: preliminary report on an obesity assessment device.

Behavioral obesity researchers are increasingly concerned with thorough assessment of obesity. The present report describes the preliminary testing and refinement of the Master Questionnaire (MQ), a true-false scale developed expressly for use in obesity research. It was initially divided into four subscales: Spouse Support, Energy Balance Habits, Cognitive Factors, and Energy Balance Knowledge, and was intended for use as an outcome measure and as a predictor of change in obesity status. Its stability, internal consistency, sensitivity to treatment-related change, and predictive validity were examined. Test-retest reliability and sensitivity to treatment-related change were each found to be acceptable for three out of four subscales. Two subscales, Energy Balance Knowledge and Cognitive Factors, predicted outcome. The major weakness of the subscales was a lack of unidimensionality which would limit their utility. Cluster and factor analyses were used to develop five new subscales with acceptable levels of internal consistency. While some additional development and validation is still needed, the available evidence suggests that we have the nucleus of a strong assessment tool for obesity research.

Adult↗

PubMed1984

First-trimester prenatal diagnosis of Tay-Sachs disease.

The prenatal diagnosis of Tay-Sachs disease was made in two at-risk fetuses by the analysis of chorionic villi obtained at 9 and 11 menstrual weeks, respectively. The diagnoses were based on the absence of beta-hexosaminidase A activity as determined by: (1) specific enzyme assays, (2) anion-exchange chromatography, and (3) cellulose acetate gel electrophoresis. The enzymatic diagnoses were confirmed on fetal tissue as well as by ultrastructural demonstration of the first-trimester fetal neuropathology. Optimal assay conditions for beta-hexosaminidase A in chorionic villi were established for the prenatal diagnosis of Tay-Sachs disease. Importantly, it was noted that a small amount of decidua or maternal blood could lead to misdiagnosis. Thus, extreme care must be taken in the preparation of chorionic villi for Tay-Sachs as well as other prenatal metabolic diagnoses.

Brain↗

PubMed1984

DNA analysis of first-trimester chorionic villous biopsies: test for maternal contamination.

We investigated the reliability of chorionic villous biopsy as a method to obtain tissues reflecting the genetic constitution of the embryo. In 12 pregnancies before elective termination, we searched for detectable maternal tissue after careful dissection of villi from small 2-5-mg specimens that yielded 7 micrograms of DNA per mg tissue. In Southern blotting experiments (1-2 micrograms DNA per lane), restriction fragment length polymorphisms (RFLPs) at an autosomal (D14S1) and a sex chromosomal (DXYS1) locus allowed recognition of maternally and embryonically derived alleles. Pure villi were obtained in six of the seven informative cases. One biopsy was not dissected satisfactorily; a mixture of embryonic and maternal DNA was found. Nonvillous tissues were mostly maternally derived in eight informative cases. Sex determination by molecular analysis (alleles at the DXYS1 locus) agreed with the karyotypes of uncultured or cultured villi. In one continuing pregnancy, distinct RFLPs indicated maternal inheritance of the alpha-thalassemia 1 trait in a female embryo without detectable maternal contamination. Reliable prenatal diagnosis depends on the specimen's purity. Maternal contamination can be evaluated by DNA analyses.

Biopsy, Needle↗

PubMed1984

A method of processing first-trimester chorionic villous biopsies for cytogenetic analysis.

Chorionic villous biopsy is emerging as a technique for obtaining fetal cells for prenatal diagnosis in the first trimester of pregnancy. Chromosome analysis has been performed on small villous biopsies using either direct harvests of uncultured cells or after culturing villous tissue. Here, we describe a method where both techniques can be used simultaneously; from a single villous biopsy, GTG-banded chromosomes of improved morphology are obtained from direct preparations and from cultured villous cells.

Biopsy, Needle↗

PubMed1984

The obstetric significance of holoprosencephaly.

The present study reviews the entity of holoprosencephaly as it relates to obstetric diagnosis and management. Classification, embryology, and etiology are summarized. Serial sonographic findings in a recent case of holoprosencephaly complicated by hydrocephalus are presented. Criteria for antenatal diagnosis and newborn recognition as well as an approach to management are proposed.

Abnormalities, Multiple↗

PubMed1984

Diagnosis and management of fetal cephalocele.

During a two-year period, nine cases of cephalocele were evaluated at the authors' perinatal ultrasound unit. There was one false positive and one false negative diagnosis. In five cases, multiple anomalies were present; three as part of the amnion rupture sequence. The obstetric management consisted of elective termination of pregnancy in five cases and cesarean section in four. The value of sonography in the diagnosis of cephalocele and associated syndromes and malformations is discussed. A plan of management and counseling based upon current understanding of prognosis is presented.

Abortion, Induced↗

PubMed1983

The diagnosis of fetal hydrocephalus.

Thirty cases of fetal hydrocephalus were diagnosed at the perinatal ultrasound unit of Yale-New Haven Medical Center during a 41 month period. Prenatal ultrasound was found to be highly valuable in the detection of fetal hydrocephalus. However, the antenatal detection of associated anomalies was not as uniformly successful. The importance of a complete sonographic evaluation of intracranial and extracranial anatomy is stressed, as 10 patients with documented hydrocephalus (37%) had associated intracranial anomalies and 17 patients (63%) had associated extracranial anomalies. In this series, isolated hydrocephalus without associated anomalies occurred in only four patients (15%).

Female↗

PubMed1983

Fetal cystic hygroma. Cause and natural history.

Fetal cystic hygromas are congenital malformations of the lymphatic system appearing as single or multiloculated fluid-filled cavities, most often about the neck. They are thought to arise from failure of the lymphatic system to communicate with the venous system in the neck. They often progress to hydrops and cause fetal death. In an effort to delineate the cause and natural history of this disorder, we studied 15 consecutive cases of nuchal hygroma detected prenatally by ultrasound. None of the 15 fetuses ultimately survived. Thirteen fetuses were hydropic at the time of diagnosis; nine either died or were bradycardic in utero before abortion; one died a few hours after birth. Eleven fetuses (73 per cent) had karyotypes consistent with Turner's syndrome, and an additional fetus with female genitalia had a 46,XY karyotype. Three fetuses had 46,XX karyotypes, and two of these had multiple malformations. When a hygroma is detected during fetal life, careful sonographic examination of the entire fetus, determination of the fetal karyotype, and an evaluation of the family history are indicated.

Abnormalities, Multiple↗

PubMed1983

The natural history of the inherited methylmalonic acidemias.

Six biochemical and genetic forms of methylmalonic acidemia have been defined previously: two (mut degrees and mut-) resulting from defects in the mutase apoenzyme, and four (cbl A, cbl B, cbl C, and cbl D) resulting from deficient adenosylcobalamin synthesis. We retrospectively surveyed the clinical presentation, response to cobalamin supplementation, and long-term outcome in the four most prevalent mutant classes by collecting detailed information on 45 patients (15 mut degrees, 5 mut-, 14 cbl A, and 11 cbl B). Most patients presented acutely with a common set of clinical and laboratory findings; however, there were significant differences between mutant classes: mut degrees patients presented earlier in infancy than did cbl A and cbl B patients; in response to cobalamin supplements, marked decreases in the concentration of methylmalonic acid in blood or urine were reported in most cbl A patients and in nearly half the cbl B patients, but not in mut degrees or mut- patients; and finally, most cbl A, cbl B, and mut- patients were still living, whereas most mut degrees patients died during the first few months of life. Our data indicate that genotypic classification of the methylmalonic acidemias has prognostic and therapeutic use as well as diagnostic value.

Amino Acid Metabolism, Inborn Errors↗

PubMed1983