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Biomedical subjects

D M Miller

Publications and source records attributed to D M Miller.

At least 217 records · Page 12Linked to original sources
PubMed1983

Leukocyte alkaline phosphatase: another organ-specific alkaline phosphatase.

We have used enzyme specific inhibitors and heat inactivation to distinguish Leukocyte alkaline phosphate (LAP) from other organ-specific alkaline phosphatases as well as to compare LAP from normal granulocytes and leukemic cells with elevated LAP. The heat inactivation and inhibition curves of LAP are quite different from those of other organ-specific alkaline phosphatases. The inhibition curves and heat inactivation characteristics of LAP from normal granulocytes and that obtained from chronic granulocytic leukemia (CGL) blast phase cells with elevated LAP are identical. These data suggest that LAP is distinct from other organ-specific alkaline phosphatases, particularly placental alkaline phosphatase. We also conclude that the LAP present in cells with elevated levels is very similar or identical to that of normal granulocytes.

Alkaline Phosphatase↗
PubMed1983

Differential localization of two myosins within nematode thick filaments.

The body wall muscle cells of the nematode, Caenorhabditis elegans, contain two unique types of myosin heavy chain, A and B. We have utilized an immunochemical approach to define the structural location of these two myosins within body wall muscle thick filaments. By immunofluorescence microscopy, myosin B antibodies label the thick filament-containing A-bands of body wall muscle with the exception of a thin gap at the center of each A-band, and myosin A antibodies react to form a medial fluorescent stripe within each A-band. The complexes of these monoclonal antibodies with isolated thick filaments were negatively stained and studied by electron microscopy. The myosin B antibody reacts with the polar regions of all filaments but does not react with a central 0.9 micron zone. The myosin A antibody reacts with a central 1.8 micron zone in all filaments but does not react with the polar regions.

Animals↗
PubMed1982

Acute aflatoxicosis in swine: clinical pathology, histopathology, and electron microscopy.

Feeder pigs weighing 12 to 15 kg each were given a single oral dose of aflatoxin, 1.2 mg/kg of body weight. Liver-specific serum enzyme activities were compared with gross, microscopic, and ultrastructural hepatic changes in individual pigs euthanatized at 24, 48, and 72 hours after they were given aflatoxin. The greater the morphologic change in liver of the treated pigs, the greater the increase in liver-specific serum enzyme activities. Isocitric dehydrogenase, alkaline phosphatase, sorbitol dehydrogenase, and aspartate aminotransferase activities increased in 6 of 8 treated pigs by 24 hours. Increase in gamma-glutamyl transpeptidase activity was not significant. Microscopic and ultrastructural changes in centrilobular hepatocytes included glycogen deletion, mitochondrial and endoplasmic reticulum swelling, membrane disruption, and nuclear fragmentation at 24 hours. The centrilobular areas had marked extravasation of erythrocytes at 24 hours without basal lamina changes. At 72 hours, the centrilobular hepatocytes had increased lipid vacuoles and acceptable amounts of glycogen. Marked infiltrations of monocytes, plasma cells, and lymphocytes were also present at this time.

Alkaline Phosphatase↗
PubMed1982

Aflatoxicol and aflatoxins B1 and M1 in the tissues of pigs receiving aflatoxin.

Aflatoxicol (AFL) and aflatoxins B1 and M1 were found in tissues (kidney, liver, and muscle) of feeder pigs given an estimated LD50 oral dose of B1 (1.0 mg/kg body weight) provided as a rice culture of Aspergillus flavus and of market-weight pigs fed a naturally contaminated feed, containing aflatoxin B1 at a level of 400 ng/g from corn, for 14 days. The residues in all tissues decreased with time after treatment in both groups, with no detectable residues (approximate detection limits, ng/g, B1 0.03, M1 0.05, AFL 0.01) in pig tissues from the feeding experiment 24 h after withdrawal of aflatoxin-contaminated feed. B1 and M1, when found in the feeding experiment, were at about the same levels in all tissues except the kidney, in which M1 was the dominant aflatoxin. The level of AFL, when detected, was about 10% of the B1 level.

Aflatoxin B1↗
PubMed1982

High performance liquid chromatographic determination and clearance time of aflatoxin residues in swine tissues.

Liver, kidney, and muscle tissues from swine given a single oral dose of 1.2 mg aflatoxins/kg body weight and from young pigs fed an aflatoxin-contaminated diet (0,400, or 800 ng/g feed) for 10 weeks were analyzed for aflatoxin residues. Extraction was performed according to the method of Stubblefield and Shotwell. Aflatoxin residues were detected by high performance liquid chromatography (HPLC), and residue levels were correlated with withdrawal times. Residues were present in liver and kidney but not muscle by 12 h post-dosing; residues were detected in muscle by after 24 h. Residue levels decreased over the 72 h period in all tissues. No aflatoxin residues were detected in the muscle from any pig 72 h post-dosing or in those pigs fed the 400 ng/g diet, but were present in the muscle of pigs fed the 800 ng/g diet.

Aflatoxins↗
PubMed1981

Membrane potentials in an acanthocephalan worm (macracanthorhynchus hirudinaceus).

The resting membrane potential of the acanthocephalan rete system in Macracanthorhynchus hirudinaceus was -35 +/- 1.5 mV (n = 20) and was dependent upon the external potassium concentration. The membrane potential reached 0 mV when the external potassium concentration was 160 mM. Spontaneous spike potentials of 45 mV +/- 10 were dependent on calcium flux. The membrane potential was depolarized by acetylcholine, potassium-free medium, calcium ions and chloride-free medium but not by changes in the external sodium concentration. Spontaneous potentials were increased in number by acetylcholine and calcium at concentrations above 3 mM, but were decreased in number by chloride- and calcium-free medium. Hence the rete system potentials are very similar to smooth muscle potentials in many respects.

Acanthocephala↗
PubMed1981

Fluorescence polarization immunoassay. II. Analyzer for rapid, precise measurement of fluorescence polarization with use of disposable cuvettes.

This instrument, developed for quantitating fluorescence polarization immunoassays, automatically measures both polarization components and computes a polarization value corrected for background and optical bias. An electronically switched liquid crystal provides a nonmechanical means of rotating the plane of polarization in the excitation optics. The electronic design features digital integration and microprocessor controlled functions. Readings are made in disposable 12 X 75 mm round culture tubes. in less than 10 s. Results are precise to 0.001 polarization unit, linear from 10(-7) to 10(-10) mol of fluorescein per liter, and correlate well with those obtained with other "high-performance" instrumentation.

Autoanalysis↗
PubMed1981

Anatomy of the cerebral ganglion in Oligacanthorhynchus tortuosa (Acanthocephala) from the opossum (Didelphis virginiana).

The anatomy of the cerebral ganglion from Oligacanthorhynchus tortuosa (Acanthocephala) resembles that previously described for large acanthocepalans from mammals. The cell population was equally distributed between each half of the ganglion, there were 38 cells on each side with seven cells centrally located. The core of the ganglion or neuropile occupied the central part of the ganglion and was the site for the crossover for many cell processes. Many of the axons from these cells exited from the side opposite the soma. The cell bodies predominated on the ventral surface while the dorsal surface was more of a mixture of cell bodies and neurites. The cytoarchitecture of these cells varied considerably but most had a large round nucleus with well-defined nucleoli. There were 83 cells, two of which were binucleate. The two binucleate cells were located at opposite extremes of the anteroposterior axis of the ganglion. The anterior binucleate cell was adjacent to the dorsal surface whereas the posterior cell was central and near the posterior terminal of the ganglion.

Acanthocephala↗
PubMed1981

Experimental aflatoxicosis in swine: morphological and clinical pathological results.

The morphological changes in livers of 30 feeder pigs fed diets containing corn contaminated by aflatoxins (0.0 microgram aflatoxins/g feed, 0.4 microgram aflatoxin/g feed, and 0.8 microgram aflatoxin/g feed) were compared with changes in hematology, liver specific serum enzymes, serum proteins, and lymphocyte stimulation indices. Histologically, the livers were classified into five groups. Pigs fed the 0.8 microgram/g diets had the most severe histological lesions of karyomegaly, bile ductule proliferation and hepatocellular degeneration plus elevated gamma-glutamyl transpeptidase, aspartate aminotransferase, and alkaline phosphatase. This group also had significantly lower total protein and albumin values compared to the control pigs. Variation in the severity of the histological lesions was seen in pigs fed 0.4 microgram/g diets as well as variation in lymphocyte indices, liver specific serum enzymes, and electrophoretic results in the affected pigs in that group.

Aflatoxins↗
PubMed1980

Computer-aided head film analysis: the University of California San Francisco method.

Computer technology is already assuming an important role in the management of orthodontic practices. The next 10 years are likely to see expansion in computer usage into the areas of diagnosis, treatment planning, and treatment-record keeping. In the areas of diagnosis and treatment planning, one of the first problems to be attacked will be the automation of head film analysis. The problems of constructing computer-aided systems for this purpose are considered herein in the light of the authors' 10 years of experience in developing a similar system for research purposes. The need for building in methods for automatic detection and correction of gross errors is discussed and the authors' method for doing so is presented. The construction of a rudimentary machine-readable data base for research and clinical purposes is described.

Cephalometry↗
PubMed1980

Improved exercise performance after exchange transfusion in subjects with sickle cell anemia.

Ten patients with sickle cell anemia underwent partial exchange transfusion with hemoglobin-A-containing cells using a technique that allowed hemoglobin concentration and blood volume to remain constant. The mean fraction of hemoglobin-A in these patients increased from 9% to 55%, but the mean hemoglobin concentration increased by only 1.44 g/dl. The exchange resulted in a large improvement in submaximal exercise capacity: the mean of the anaerobic threshold (the work at which lactic acid begins to accumulate in the blood) increased from 68 to 114 W. The mean work performed at a heart rate of 170/min, an estimation of maximal work capacity, increased from 128 to 187 W. Improved exercise performance after partial exchange transfusion may result from the superior flow properties of hemoglobin-A-containing red cells. Furthermore, we believe that exercise testing in sickle cell anemia has great potential utility as a means to monitor therapy and to evaluate the benefits of exchange transfusion.

Adult↗
PubMed1979

Location of the sugar-binding site of L-arabinose-binding protein. Sugar derivative syntheses, sugar binding specificity, and difference Fourier analyses.

The sugar-binding site of the L-arabinose-binding protein, an essential component of the high affinity L-arabinose uptake system in Escherchia coli, is located deep in a cleft formed by the asymmetric contributions from both of the two similar domains. The site was unambiguously identified with the electron-rich substrate analog 6-bromo-6-deoxy-D-galactose in a difference Fourier analysis. The observation that the original native structure might have been solved with bound L-arabinose necessitated the synthesis of a heavy atom analog, its structure consistent with the known sugar-binding specificity of the protein. Difference Fourier maps (3.5 A) of crystals soaked in 46 mM analog showed a peak 3.5 times background, which is attributed to the -CH2Br moiety of the analog. Superposition of a difference map onto a 2.8-A native electron density map indicated that the difference peak is 6 to 7 A from the reactive single cysteine (Cys-64) and partially coincident with an "extraneous" density found in the native map. This "extraneous" peak was previously attributed to a bound L-arabinose molecule, and its presence accounts for the early failures of difference Fourier analyses of crystals soaked in or co-crystallized with L-arabinose to locate the sugar-binding site.

Arabinose↗
PubMed1979

A new universal anaesthetic circuit using a preferential-flow T-piece.

A new co-axial anaesthetic circuit, employing a preferential-flow T-piece which eliminates the need for valves in the circuit, has been designed. Its efficiency has been shown to compare favourably with that of conventional circuits for use in spontaneous respiration and under conditions of controlled ventilation. The proposed system has the advantage of convenience, in that there is no need to disconnect the system from the patient nor from the anaesthetic machine when it is necessary to change from spontaneous to controlled ventilation or should a circle absorber be incorporated within the circuit. The system has been shown to offer lower resistance than the Mapleson A circuit.

Anesthesia, Inhalation↗