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Biomedical subjects

G Matrone

Publications and source records attributed to G Matrone.

At least 19 recordsLinked to original sources
PubMed1993

A large screen digitizer system for radiation therapy treatment planning.

PURPOSE: This paper describes a new technique for manually drawing contours of anatomy over image data for the purposes of radiation therapy treatment planning. METHODS AND MATERIALS: A large area rear-projectible digitizer tablet is used together with a projection TV system to display computer graphics and image data. Large images of computed tomography or magnetic resonance cross-sections are displayed and the digitizer is used to directly trace outlines of important organs. Digitizer menus allow multiple functions for selecting images and structures, for changing the grayscale level and window, and for zooming and roaming the image. RESULTS: This device has been in clinical operation for many years and has proven to greatly increase the speed of entering cross-sectional outlines defined for serial computed tomography images sets. A small timing study of clinical usage demonstrates up to a factor of ten improvement in the speed of contour entry. CONCLUSION: For 3-dimensional radiation therapy, tumor, and target volumes, as well as important critical organs, must be delineated from serial sets of computed tomography or magnetic resonance images. Often 30 or more slices must be considered and the process of outlining structures on this number of slices can represent a significant fraction of the total treatment planning time. The device described in this paper greatly improve the ease and speed of manual contour entry for 3-dimensional radiation therapy planning.

Humans↗
PubMed1976

Controlling factors in the development of ceruloplasmin in pigs during the neonatal growth period.

The sequence of ceruloplasmin development and limiting factors controlling this process in neonatal piglets was studied in a randomized block design. Guided by the change in serum ceruloplasmin levels, the liver copper concentrations of piglets fed copper-deficient and copper-supplemented diets were compared in three different periods. The plasma of piglets was devoid of both apo- and holo-ceruloplasmin at birth. The system responsible for the synthesis of apoceruloplasmin developed shortly after birth as indicated by a steady increase in serum ceruloplasmin activity during the first week without being affected by the diet. Copper apparently was not the limiting factor at this stage since very high concentrations of copper were found in the livers of newborn piglets. However, the liver copper was depleted quickly within 1 to 2 weeks and became the limiting factor if the diet was deficient in copper. The livers of these piglets were fractionated by differential centrifugation to compare the liver copper distribution in the two dietary groups with and without copper supplementation. The treatments did not affect the copper distribution on a percentage of total liver copper basis. However, fractionation study revealed that, unlike adult pig livers, about 70% to 80% of copper was present in the heavier particle fractions of piglet livers.

Age Factors↗
PubMed1975

Development of ceruloplasmin in pigs during the neonatal period.

Colostrum-free newborn pigs were raised artificially to investigate the appearance of ceruloplasmin in the serum of piglets. The sensitivity of the p-phenylenediamine oxidase activity assay, commonly used as a measure of ceruloplasmin, has been increased 10-fold. Based on this activity, no evidence was found that this copper protein was present in the serum of baby pigs at birth, although some evidence was obtained that the protein moiety (apoceruloplasmin) was present. Holoceruloplasmin usually became detectable in the serum 10-15 hours after birth. Its concentration increased slowly at first and then at an accelerated rate. The ceruloplasmin in the sera of 2-3-day-old piglets was isolated and compared with that isolated from the serum of adults. Contrary to a previous report, the physical and chemical properties of ceruloplasmin synthesized during the first 3 days of life of the piglet showed no significant difference from that synthesized by the adult.

Age Factors↗
PubMed1975

Effect of molybdate on sulfide production from methionine and sulfate by ruminal microorganisms of sheep.

Purified diets containing sodium sulfate and DL-methionine as sole dietary sources of sulfur were fed to fistulated sheep. The effect of dietary sodium molybdate (50 ppm Mo) on the capacity of the rumen microorganisms to produce sulfide from either sulfate or methionine was assayed in the two sulfur diets. Dietary molybdenum significantly inhibited the production of sulfide from sulfate but enhanced significantly the production of sulfide from methionine. The inhibitory effect of molybdenum on sulfide production in vitro and the number of sulfide-producing bacteria present in the rumen of these sheep are discussed in considering the mechanism of the molybdate effect on sulfide production.

Animals↗
PubMed1975

Methodological studies on the uptake of zinc by 3T3 cells.

In the present work, experiments were conducted on the uptake of zinc by 3T3 cells. (1) The percent Zn uptake gradually decreased with addition of increasing amount of zinc (0.05-8.4 mug). (2) With the increase of the incubation period from 2 to 16 hr, Zn uptake by nearly confluent cells increases gradually; however, confluent cells which are newly replated show a distinct cyclic increase in the Zn uptake after 2, 6, and 10 hr. (3) The amino acids of DMM and serum decrease Zn uptake. (4) Histidine at a molar excess of 1:50, 1:500, and 1:5000 reduces Zn uptake in comparison to a treatment with 65Zn-Zn-L-hist2 at a molar ratio of 1:5. (5) When zinc is added in the form of different Zn compounds, at a molar ratio of 1:2 or 1:1 (Zn:ligand), EDTA decreases the Zn uptake markedly. A small influence was shown also by albumin and histidine; however, other amino and organic acids at a molar ratio of 1:2 did not alter Zn uptake significantly.

Animals↗
PubMed1974

Sulfate reduction by a Desulfovibrio species isolated from sheep rumen.

Several dissimilatory, sulfate-reducing bacteria were isolated from the rumen fluid of sheep fed purified diets containing sulfate. One isolate, strain D, was selected for characterization. This organism is a nonsporeforming, obligately anaerobic, mesophilic, nonmotile, gram-negative, straight rod. Cell-free extracts show absorption maxima for cytochrome c(3) and desulfoviridin, characteristic of Desulfovibrio. Carbohydrates, as a sole carbon source, will support growth. Lactate supports growth in the presence of sulfate, not in its absence, whereas glucose or pyruvate support growth either in the presence or absence of sulfate. The isolate has a deoxyribonucleic acid base composition of 61.2% guanine plus cytosine, which is similar to that of several other species of Desulfovibrio; however, it differs from previously described species in morphology, motility, and carbon source utilization. Cell-free extracts of this bacterium exhibit adenosine 5'-triphosphate-sulfurylase, adenosine-5'-phosphosulfate-reductase, and hydrogenase activity. After incubation of cell-free extracts with adenine 5'-triphosphate and (35)SO(4) (2-), adenosine-5'-phosphosulfate rather than 3'-phosphoadenosine-5'-phosphosulfate was shown to be labeled, indicating that the pathway of sulfate reduction in this organism is similar to that of other dissimilatory sulfate reducers. This is the first report of a Desulfovibrio sp. isolated from the rumen.

Anaerobiosis↗