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Biomedical subjects

J Miller

Publications and source records attributed to J Miller.

At least 19 recordsLinked to original sources
PubMed1979

Antenatal diagnosis of neural tube defects in Canada: extension of a collaborative study.

Experience with the diagnosis of neural tube defects from alpha1-fetoprotein (AFP) concentrations in amniotic fluid is reported from a prospective study of five laboratories testing for 13 Canadian genetic centres. The results of the study indicate that antenatal diagnosis of open neural tube defects is being carried out effectively in Canada (in 99.2% of cases the AFP measurements were interpreted correctly). Amniocentesis should be recommended to women at high risk for having a child with a neural tube defect (i.e., those who have a child, a parent or a sibling with a neural tube defect). The rate of neural tube defects in 182 high-risk pregnancies was 2.2% for an open defect and 1.1% for a closed defect, whereas the rate in 673 pregnancies in which amniocentesis was being performed for other reasons was 0.3%. This suggests that the AFP concentration should be measured in any sample of amniotic fluid collected for other reasons (usually fetal karyotyping). There were three instances of false-negative results, for a rate of 0.4%. Two closed neural tube defects were not detected; this limitation of the test has also been found by others. One of the six fetuses with an open neural tube defect, who died in utero, had a large myelocele in the neck that was not recognized. There were also four instances of false-positive results, for a rate of 0.5%. The findings suggest that AFP values that are more than 2 but less than 7 standard deviations (SDs) above the mean may indicate a neural tube defect, and that values 7 or more SDs above the mean very likely indicate such a defect, although other reasons for such high values (e.g., fetal erythrocytes in the amniotic fluid, intrauterine death and mistaken gestational age) must be ruled out by other methods.

Amniocentesis↗
PubMed1979

Measurement of colloid clearance rate as an adjunct to static liver imaging.

A technique for the measurement of the rate of uptake of 99mTc labelled sulphur colloid in the liver using a gamma camera and computer is described. The mathematical model showing the factors affecting the rate of uptake, and the results of the measurements in a series of normals and patients with a variety of liver diseases are presented. The range in cirrhosis was found to be significantly lower than normal and the range in acute liver injury significantly higher. The technique can easily be incorporated into a standard colloid liver imaging procedure and is considered to be a valuable adjunct to diagnosis using the static images.

Colloids↗
PubMed1979

Orbital cellulitis due to Neisseria gonorrhoeae in an enucleated socket.

Orbital cellulitis due to Neisseria gonorrhoeae developed in an adolescent girl in a previously enucleated socket. Since this organism also was isolated from her pharynx, the orbital infection probably resulted from contamination of the prosthesis by gonococci from her mouth, either directly or by transfer from her fingers.

Adolescent↗
PubMed1979

Proton magnetic resonance studies of cholinergic ligand binding to the acetylcholine receptor in its membrane environment.

Proton magnetic resonance has been used to monitor binding of choline, a known partial agonist, to acetylcholine receptor-enriched membrane preparations from Torpedo californica electroplax. The interaction between choline and receptor led to a broadening of the resonance of the choline methyl groups and this effect was reversed by alpha-bungarotoxin, a quasi-irreversible antagonist of the acetylcholine receptor. From the concentration dependence of line broadening the equilibrium dissociation constant for choline was obtained (Kd = 190 +/- 65 microM). The temperature dependence of the parameters observed in the choline titrations gave an enthalpy of binding delta H less than 1.5 kcal/mol and allowed estimates for the dissociation rate constant of the receptor-choline complex (kdiss greater than 1.6 x 10(3) S(1) and the respective activation energy, Ea (Kdiss) approximately 5.5 kcal/mol. The association of other ligands with the membrane-bound receptor could also be studied by observing effects of varying concentrations of such ligands on the choline methyl group linewidth at a constant choline concentration.

Animals↗
PubMed1979

Clinical comparison of skin testing and the radioallergosorbent test in dog-sensitive patients using mixed and breed-specific antigens.

A study of clinical history, intradermal test end points and RAST values with six different dog antigens was made in 20 patients and 5 control subjects. Skin testing was found to be more useful clinically than the RAST. Considerable variability among mixed epidermal extracts was noted. There was no apparent advantage to testing with three individual-breed extracts studied, compared to the most potent mixed epidermal antigen. The results of this study suggest that further efforts toward standardization of potency, methods of preparation and, possibly, breed composition of dog allergenic extracts are required to develop improved allergens for clinical use.

Animals↗
PubMed1979

Segmental pancreatic transplantation in pigs.

Segmental pancreatic allotransplants were performed intraperitoneally in pigs with and without ligation of the duct. Exocrine pancreatic function was suppressed by the administration of glucagon. All recipients also received high doses of methylprednisolone for the first 10 days after transplant as well as cyclophosphamide until death or sacrifice. Some animals received antilymphocyte globulin (ALG) in addition. Diabetes was induced by total panreatectomy. Allotransplantation in pancreatectomized animals was successful in preventing hyperglycemia for up to 33 days of observation. ALG in the dosage used did not show any beneficial effects and varying degrees of rejection occurred in the majority of these unmatched animal pairs. Grafts without ligation of the duct seemed to show the best preservation of tissue because of absence of obstructive damage following duct ligation. Of significance is the fact that no intraperitoneal inflammatory or infectious complications occurred in recipients of either duct-ligated or unligated grafts, presumably because of suppression of exocrine function with glucagon and the reabsorptive capability of the peritoneal surface. We speculate that this is a satisfactory physiological model for continued trials in pancreatic transplantation, although antirejection therapy was far from satisfactory.

Animals↗
PubMed1979

Protein quality of several multi-component, commercially prepared foods.

Eleven commercial food products that may be considered by consumers to be major sources of protein were evaluated. Most of these items contained significant amounts of carbohydrate in the form of cereal products or purified sugars. Seven of the products were at least equal to casein in protein efficiency ratio (PER). Canned spaghetti and meat balls, the TV dinner, canned chicken-and-vegetable baby food, and food bars had PER values between 91 and 73 per cent of that of casein, while PER values for ground beef and high-protein cereal were significantly higher than casein.

Animals↗
PubMed1979

Cognitive influences on perceptual processing.

These experiments investigate the influence of frequency of occurrence of a visual stimulus (stimulus probability) on encoding processes, in an attempt to discover what sorts of mechanisms allow cognitive processes to modify perceptual processes. Experiments 1 and 2 show that frequently occurring visual letters do not facilitate encoding of visually similar letters. This implies that stimulus probability does not directly affect the feature detectors used in encoding the letters. Four more experiments provide evidence that stimulus probability has its effect on the availability of an abstract code that is generated by the encoding process from the visual input. Results from the experiments with letter stimuli could be interpreted using a model similar to the logogen model of Morton. Experiments with nonsense forms suggest that subjects use abstract codes in dealing with the forms only when the stimuli are constructed from a set of orthogonal features. A secondary finding was that visual quality has an effect that extends past the feature analysis stage and into a stage in which the visual input activities an abstract code. This result calls into question the common practice of interpreting the interaction of a factor with visual quality as evidence that the factor affects visual feature analysis.

Cognition↗