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Biomedical subjects

D C Morris

Publications and source records attributed to D C Morris.

At least 127 records · Page 7Linked to original sources
PubMed1985

Purification and partial characterization of alkaline phosphatase of matrix vesicles from fetal bovine epiphyseal cartilage. Purification by monoclonal antibody affinity chromatography.

Alkaline phosphatase of matrix vesicles isolated from fetal bovine epiphyseal cartilage was purified to apparent homogeneity using monoclonal antibody affinity chromatography. The enzyme from the butanol extract of matrix vesicles bound specifically to the immobilized antibody-Sepharose in the presence of 2% Tween 20 whereas the major portion of nonspecific protein was removed by this single step. Of various agents tested, 0.6 M 2-amino-2-methyl-1-propanol, pH 10.2, was the most effective in eluting 80-100% of the enzyme initially applied. Both Tween 20 and 2-amino-2-methyl-1-propanol associated with the eluted enzyme were effectively removed by the sequential application of DEAE-cellulose and Sepharose CL-6B chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the enzyme preparation treated with sodium dodecyl sulfate and mercaptoethanol showed the presence of a dominant band (using silver staining) corresponding to a molecular weight of 81,000. This molecular weight was nearer reported values for rat liver (Ohkubo, A., Langerman, N., and Kaplan, M. M. (1974) J. Biol Chem. 249, 7174-7180) and porcine kidney (Cathala, G., Brunel, C., Chapplet-Tordo, D., and Lazdunski, M. (1975) J. Biol. Chem. 250, 6040-6045) alkaline phosphatase, than to previously reported values for chicken (Cyboron, G. W., and Wuthier, R. E. (1981) J. Biol. Chem. 256, 7262-7268) and fetal calf (Fortuna, R., Anderson, H. C., Carty, R. P., and Sajdera, S. W. (1980) Calcif. Tissue Int. 30, 217-225) cartilage matrix vesicle alkaline phosphatase. The purified alkaline phosphatase was activated by micromolar Mg2+. The amino acid composition of cartilage alkaline phosphatase was found to be similar to that previously described for porcine kidney (Wachsmuth, E. D., and Hiwada, K. (1974) Biochem. J. 141, 273-282). Double immunoprecipitation data indicated that monoclonal antibody against cartilage alkaline phosphatase cross-reacted with fetal bovine liver or kidney enzyme but failed to react with calf intestinal or rat cartilage enzyme. Thus these observations suggest that alkaline phosphatase of matrix vesicles from calcifying epiphyseal cartilage is a liver-kidney-bone isozyme.

Alkaline Phosphatase↗
PubMed1984

Isolation of a plasma membrane-enriched fraction from collagenase-suspended rachitic rat growth plate chondrocytes.

An attempt was made to concentrate plasma membranes of homogenized chondrocytes isolated by collagenase digestion of rachitic rat epiphyseal growth plate cartilage. This study reports the characterization of enzymes in the plasma membrane of isolated chondrocytes and their comparison with extracellular matrix vesicle components. The plasma membrane-enriched fractions that were obtained showed a sevenfold increase in 5'-nucleotidase and a 15-fold increase in alkaline phosphatase, both of which are regarded as plasma membrane markers. SDS-polyacrylamide gel electrophoretic profiles of proteins extracted from membrane fractions contained several major protein bands also seen in isolated matrix vesicles. These studies indicate the usefulness of concentrating plasma membrane components from isolated chondrocytes, after the chondrocytes have been enzymatically freed from investing matrix and other stromal components by collagenase.

Alkaline Phosphatase↗
PubMed1984

Popliteal artery entrapment demonstrated by CT.

The computed tomographic (CT) findings in a young man with bilateral popliteal entrapment are presented. CT may be the procedure of choice in young adults with intermittent claudication.

Adult↗
PubMed1984

The effects of lanthanum on the ultrastructure of hypertrophic chondrocytes and the localization of lanthanum precipitates in condylar cartilages of rats fed on normal and rachitogenic diets.

Ionic lanthanum was used to examine the distribution of calcium-binding sites in the condylar cartilages of rats that had been fed on normal and/or vitamin D-deficient rachitogenic diets for 4 weeks. Certain specific changes in the ultrastructure of the cartilage were attributed to the presence of the trivalent cation in the fixation medium. Cartilages from the rachitic animals showed a marked reduction in the quantity of lanthanum deposition on the outer surface of the chondrocytes and in the extracellular matrix. Returning rachitic rats to the control diet resulted in a corresponding return to a normal ultrastructural distribution of lanthanum in the condylar cartilages. No intracellular lanthanum deposits were observed. The results suggest that a vitamin D-dependent calcium-binding component may be an integral part of the chondrocyte plasma membrane structure.

Animals↗
PubMed1983

Subselective embolization for non-neoplastic conditions of the kidney.

Three patients in our institution underwent subselective arterial embolization for treatment of intractable renal hemorrhage. In all three patients control of bleeding was obtained. The only complication encountered was a non-occlusive dissection of a segmental renal branch in one patient. Although some tissue infarction will result, less renal parenchyma will be lost than is the case with surgical treatment.

Adult↗
PubMed1981

Single-visit oral cholecystography for inpatients.

A new one-day medication schedule for single-visit oral cholecystography is described, using both Telepaque (iopanoic acid) tablets and Oragrafin Sodium (sodium ipodate) capsules. A definitive report is rendered at the first sitting; no repeat studies are performed. Preliminary results in 45 patients demonstrate the accuracy of this technique. One-day medication makes single-visit oral cholecystography suitable for hospitalized patients.

Cholecystography↗
PubMed1980

Ultrastructural localization of calcium in the mandibular condylar growth cartilage of the rat.

The potassium pyroantimonate technique was utilized for the selective subcellular localization of calcium in the mandibular condylar cartilage of 1-day-old rats. Electron dense calcium pyroantimonate precipitates were localized principally in mitochondria and at the cell membrane of the chondrocytes. In addition, small intracellular vesicles 0.1-0.2 micrometers in diameter were observed in proximity to the cell membrane of chondrocytes of the mid-hypertrophic zone. The results suggest that these vesicles were being extruded from the cell into the extracellular matrix. Energy-dispersive analysis by X-rays confirmed that calcium is the principal cation of the electron-dense precipitates.

Animals↗
PubMed1980

Biliary stricture dilatation: use of the Grüntzig balloon catheter.

The Grünzig ballon catheter in use for angioplasty was found well suited for the dilatation of strictures in the biliary tract. It may be applied in benign or malignant strictures or for dilatation of the T-tube sinus tract. The application of the ballon catheter is described for malignant stricture dilatation preceding internal biliary drainage procedures.

Adenoma, Bile Duct↗
PubMed1979

Late hemodynamic evaluation of Hancock Modified orifice aortic bioprosthesis.

Nineteen patients with Hancock Modified Orifice prosthesis (HMO-250), size 19 to 23 mm, were recatheterized 6 to 16 months following aortic valve replacement (AVR). Although hemodynamic characteristics varied widely, HMO-250 compared favorably to the standard model 243 (less than 0.05). Mean peak resting gradient across HMO-250 was 14.8 torr at rest and rose to 26.8 torr with exercise. Systolic gradients for HMO-250, both resting and exercise, were improved for 21 mm (p less than 0.01), but not for 23 mm. Increasing the patient's body surface area (BSA) correlated with increasing gradients for 23 mm (p less than 0.05), but was unrelated to 21 mm. Effective orifice areas were similarly found to be improved with 21 mm HMO-250 but unchanged for 23 mm. Use of the 21 or 23 mm size HMO for AVR is supported only when the patient's body surface area is less than 1.8 m2. If the body surface area is greater than 1.8 m2, annulus enlargement and a larger size bioprosthesis should be employed. Use of 19 mm porcine xenograft for AVR is not supported.

Aortic Valve Insufficiency↗
PubMed1979

The use of the potassium pyroantimonate-osmium method as a means of identifying and localizing calcium at the ultrastructural level in the cells of calcifying systems.

Potassium pyroantimonate-osmium has been used to localize calcium as an electron dense precipitate in the odontoblast, ameloblast and early hypertrophic chondrocytes of the mandibular condylar growth cartilage. The precipitate exhibited a specific association with various cell organelles. The presence of calcium in the precipitates was confirmed using energy dispersive analysis by x-rays. It is suggested that this K-pyroantimonate method provides an accurate technique for the investigation of the subcellular localization of calcium in calcifying systems.

Animals↗
PubMed1979

Valve disease.

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Adult↗
PubMed1978

Hemodynamic and clinical evaluation of the Hancock xenograft bioprosthesis of aortic valve replacement (with emphasis on management of the small aortic root).

One hundred twenty-nine consecutive patients underwent isolated aortic valve replacement with the Hancock porcine xenograft between July, 1974, and December, 1976. The hospital mortality rate was 3.9 percent. No patient was treated with anticoagulants, and valve-related complications were extremely rare. The smaller prosthetic sizes (19 and 21 mm. stent diameter) should be used with extreme caution, and the 19 mm. prosthesis should probably never be used in the audult patient. Two methods of managing the small aortic root are emphasized: one to avoid using the smaller prosthetic size in adults and the other to alter greatly the root size in children who have a hypoplastic aortic annulus. Acceptable calculated orifice sizes and left ventricular--aortic (LV-Ao) pressure gradients may be obtained with the 23 mm. or larger prostheses. Actuarial survival curves show 92 percent of patients alive and well at 24 months' follow-up.

Adolescent↗