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Biomedical subjects

R A Doherty

Publications and source records attributed to R A Doherty.

At least 55 records · Page 3Linked to original sources
PubMed1978

A simple procedure for obtaining large quantities of tubulin subunits from newborn mouse brain.

A simple, efficient two-step procedure of DEAE--Sephadex A--50 column chromatography followed by hydroxyapatite column chromatography for purification of alpha- and beta-tubulin subunits from newborn mouse brain is described. Stored frozen mouse brains can be used as a convenient starting material. Differential elution of alpha and beta subunits from hydroxyapatite was achieved using a linear gradient of 0.2--0.3 M phosphate buffer containing 2 M urea, 0.1% sodium dodecyl sulphate and 1 mM dithiothreitol. 20 mg of alpha-tubulin (purity: greater than 85%) and 16 mg of beta-tubulin (purity greater than 95%) completely separated from each other can be obtained in one experiment.

Animals↗
PubMed1978

Exchange transfusion treatment of methylmercury-poisoned children.

Three children, ages 6 months, 13 months and 10 years were treated by exchange transfusions following exposure to methylmercury in the Iraq outbreak in 1971-72. Two had severe signs of poisoning and the other was clinically normal but had a high blood mercury concentration. Exchange transfusion resulted in clearance of mercury not only from blood but also from other tissues. The average amount of mercury removed in a two hour exchange was estimated as 6% of the body burden as compared to 1% of the body burden removed by normal excretion processes in 24 hours. No dramatic improvement in the clinical condition of the two poisoned patients occurred. Some improvement in motor power and function was observed during follow-up visits to their houses.

Child↗
PubMed1978

Ultrasound placental site in relation to bloody taps in midtrimester amniocentesis.

In an unselected, consecutive series of 137 midtrimester amniocenteses for prenatal genetic diagnosis, it was found that the incidence of blood contamination of amniotic fluid samples was similar regardless of placental site as determined by ultrasound localization. Three (5.8%) patients with anterior placental location versus 5 (9.1%) patients with posterior placentas had gross blood in the amniotic fluid by visual inspection. These results support the view that placental penetration during amniocentesis is not the major cause of bloody taps. Ultrasound studies done prior to midtrimester amniocentesis should, perhaps, be more specifically evaluated in relation to pregnancy information obtained rather than solely as an aid to improve technical performance of amniocentesis.

Amniocentesis↗
PubMed1976

Perinatal methylmercury poisoning in Iraq.

The signs and symptoms of methylmercury poisoning and the concentrations of mercury in samples of blood, hair, and milk are reported and compared in two infant-mother pairs exposed in the recent Iraq outbreak. In one pair, the infant was born prior to the exposure of the mother, and was exposed only from ingestion of methylmercury in mother's milk. In the other pair, the mother was exposed during pregnancy and did not breast feed the infant, who died 30 days after birth. Both mothers had some signs and symptoms of poisoning, but the infants did not. The infants had maximum estimated blood mercury levels between 500 and 1,000 ng/ml, well above the minimum toxic levels for adults. Hair and blood concentrations of mercury correlated closely, the average hair-blood ratio being about 250. Maternal milk averaged 8.6% of the simultaneous blood level, but the relationship was nonlinear at blood mercury levels below 50 ng/ml. Postnatal exposure by suckling led to substantial infant blood mercury concentration (over 600 ng/ml), and prenatal exposure resulted in blood mercury levels in the infant at birth higher than those in the mother, even after corrections for differences in hematocrit level.

Adult↗
PubMedDate not supplied

Analysis of deletions in DNA from patients with Becker and Duchenne muscular dystrophy.

Duchenne muscular dystrophy (DMD) is an X-linked recessive genetic disorder for which the biochemical defect is as yet unknown. Recently, two cloned segments of human X-chromosome DNA have been described which detect structural alterations within or near the genetic locus responsible for the disorder. Both of these cloned segments were described as tightly linked to the locus and were capable of detecting deletions in the DNA of boys affected with DMD. In an attempt to determine more precisely the occurrence of these deletions within a large population of DMD patients and the accuracy of one of the segments, DXS164 (pERT87), in determining the inheritance of the DMD X chromosome, the subclones 1, 8 and 15 were made available to many investigators throughout the world. Here we describe the combined results of more than 20 research laboratories with respect to the occurrence of deletions at the DXS164 locus in DNA samples isolated from patients with DMD and Becker muscular dystrophy (BMD). The results indicate that the DXS164 locus apparently recombines with DMD 5% of the time, but is probably located between independent sites of mutation which yield DMD. The breakpoints of some deletions are delineated within the DXS164 locus, and it is evident that the deletions at the DMD locus are frequent and extremely large.

Chromosome Deletion↗