Search PubMed⌕ Search

Biomedical subjects

A Whitelaw

Publications and source records attributed to A Whitelaw.

At least 109 records · Page 6Linked to original sources
PubMed1983

Early and late neonatal septicaemia.

Between 1979 and 1982 we reviewed 1000 consecutive admissions to the neonatal intensive care unit of this hospital. Sixty five infants had positive blood cultures. Mortality was 70% among 17 infants who had septicaemia in the first 48 hours of life and for whom appropriate treatment may have been too late because of difficulties of early diagnosis. In the remaining 48 infants mortality was 12%, septicaemia occurred later, and was associated with Staphylococcus epidermidis (56%) and with the presence of an intravascular catheter (50%).

Bacterial Infections↗
PubMed1983

Clinical NMR imaging of the brain in children: normal and neurologic disease.

The results of initial clinical nuclear magnetic resonance imaging of the brain in eight normal and 52 children with a wide variety of neurologic diseases were reviewed. The high level of gray-white matter contrast available with inversion-recovery sequences provided a basis for visualizing normal myelination as well as delays or deficits in this process. The appearances seen in cases of parenchymal hemorrhage, cerebral infarction, and porencephalic cysts are described. Ventricular enlargement was readily identified and marginal edema was demonstrated with spin-echo sequences. Abnormalities were seen in cerebral palsy, congenital malformations, Hallervorden-Spatz disease, aminoaciduria, and meningitis. Space-occupying lesions were identified by virtue of their increased relaxation times and mass effects. Nuclear magnetic resonance imaging has considerable potential in pediatric neuroradiologic practice, in some conditions supplying information not available by computed tomography or sonography.

Brain↗
PubMed1982

Nuclear magnetic resonance imaging of the brain in children.

A preliminary study of nuclear magnetic resonance imaging of the brains of four normal children (36 weeks' postmenstrual age to 5 years) showed long T(1) areas in the periventricular region of the neonate as well as evidence of progressive myelinisation with increasing age. Study of 18 patients of 40 weeks' postmenstrual age to 4 years showed an apparent deficit in myelinisation in an infant with probable rubella embryopathy and another with ventricular dilatation of unknown cause. Abnormal scans were obtained in an infant with congenital muscular dystrophy, and abnormalities were visualised at the lateral ventricular margins in a case of acute hydrocephalus after shunt blockage. Periventricular regions of increased T(2) were seen in a term infant aged 4 days after severe birth asphyxia and convulsions.Nuclear magnetic resonance imaging appears to provide a unique demonstration of myelinisation in vivo and shows changes in pathological processes of importance in paediatric practice.

Brain↗
PubMed1982

Characteristics of plasma membrane isolated from a mouse T lymphoma line: comparison after nitrogen cavitation, shearing, detergent treatment, and microvesiculation.

Plasma membrane was isolated from the mouse T lymphoma cell line WEHI-22 using four different methods of cell disruption followed by centrifugal fractionation. Disruption by nitrogen cavitation or by shearing with a cell pump produced plasma membrane vesicles of similar buoyant density (1.10 g/ml) and morphological appearance. Few C-type virus particles were present. Cell disruption with 2% Tween-40 produced membrane vesicles of similar morphology but lower density (1.09 g/ml). All of the above preparations resulted in vesicles with aggregated intramembranous particles after freeze fracture. Microvesiculation with sublytic concentration of a lysophosphatidylcholine analog (ET-12-H) (0.0032% w/v) produced small membrane vesicles which could be isolated without differential centrifugation. However, these had a slightly higher density than vesicles prepared by cavitation or shearing and were contaminated by virus particles. Unlike the other preparations, vesicles prepared with ET-12-H had dispersed intramembranous particles. The enzyme gamma-glutamyl transferase was enriched from 20- to 45-fold in the membrane preparations and proved a suitable plasma membrane marker for these cells whose 5'-nucleotidase content is very low.

Animals↗
PubMed1981

Further studies in the control of ovine fascioliasis by strategic dosing.

Three hill sheep flocks were used to study the effect of the strategic use of rafoxanide to kill liver flukes before they attained the adult egg-laying stage. The programme ran from 1973 to 1976. In November 1976 the programme was stopped in one flock but was continued in the other two, which were subsequently merged. The results of frequent whole flock monitoring since 1976, described here, showed that in both flocks the level of infection, as judged by the examination of faeces for the presence of Fasciola hepatica eggs, remained at a very low level. It is postulated that the adoption of a strategic dosing programme over a period of three to four years would limit egg deposition on pastures close to eradication levels and that several years without needing to use anthelmintics against liver flukes would ensue.

Animals↗
PubMed1981

Immotile cilia syndrome: a new cause of neonatal respiratory distress.

Kartagener's syndrome is a condition that consists of situs inversus, bronchiectasis, and sinusitis. Some patients have respiratory symptoms that date from early infancy, and electron microscopical examination has shown that adults with this condition lack dynein arms in ciliary microtubules. It has been suggested that an inherited defect in ciliary ultrastructure, the immotile cilia, is the basis for the syndrome. We report 6 patients who presented within the first 24 hours of life with tachypnoea, retraction, rales, and dextrocardia. Five of them had situs inversus. They all responded to physiotherapy after antibiotics had failed to improve their condition. Electron microscopical examination of the cilia in 2 of the infants confirmed deficiency of dynein arms. All 6 infants had recurrent respiratory infections. Four went on to develop recurrent otitis media, 2 had sinusitis, and 1 now has bronchiectasis. The immotile cilia syndrome should be added to the list of causes of respiratory distress in newborn infants. The condition is worth diagnosing because of the good response to physiotherapy, and because of the likelihood of recurrent respiratory problems.

Cilia↗
PubMed1981

Alkaline phosphatase in hematopoietic tumor cell lines of the mouse: high activity in cells of the B lymphoid lineage.

Alkaline phosphatase (EC 3.1.3.1) was assayed in a large number of cultured mouse tumor cell line using p-nitrophenylphosphate as the substrate. Of 19 lines of the B lymphoid lineage, including Abelson pre-B, B lymphoma, and plasma cell tumor lines, all but 1 had substantial activity averaging 407 nmol/min/mg protein (with a range from 5 to 900). Nine T lymphoid and 9 nonlymphoid hematopoietic lines examined had low activity of 0.7 to 4.2 nmol/min/mg protein. The enzyme was markedly enriched in plasma membrane preparations from the B lymphoid cells, but not in those from most T lymphoma cells. The activity of another plasma-membrane-bound enzyme, gamma-glutamyl transferase, did not vary systematically with the type of cell line but was exceptionally high in 1 T lymphoma line. Investigation of pH dependence and susceptibility to inhibition by L-phenylalanine and L-homoarginine indicated similarity of the alkaline phosphatase from B cell lines to the enzyme recoverable from normal mouse kidney, placenta, bone marrow, and lymphoid organs. The enzyme seems to provide a useful marker for tumor lines of the B lymphoid lineage and for their plasma membranes.

Alkaline Phosphatase↗
PubMed1980

Passive immunity in calf rotavirus infections: maternal vaccination increases and prolongs immunoglobulin G1 antibody secretion in milk.

Ten heifers were inoculated on two occasions with an inactivated preparation of tissue culture-grown calf rotavirus, and a further ten heifers received a placebo vaccine. Serum anti-rotavirus antibody titers were significantly increased throughout pregnancy in the vaccinated group. After calving, the mean neutralizing antibody titer of colostral whey in control cows was 100, associated with immunoglobulins A and G1. No antibody was detected in the milk of these cows after the 4th day postpartum. The colostral whey from the vaccinated cows had a mean antibody titer of 20,452; 28 days after calving, the mean milk antibody titer was 320, associated mainly with immunoglobulin G1. Calves were challenged with a large oral inoculum of calf rotavirus at the 7th day of age. There was significant lengthening of the incubation and prepatent periods in calves born to vaccinated dams, but rotavirus-associated diarrhea of equal severity occurred in both groups. Evidence is presented which suggests that rotavirus antibody in milk can protect against a smaller challenge dose. Maternal immunization against rotavirus may be a practical proposition.

Animals↗