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Biomedical subjects

P Person

Publications and source records attributed to P Person.

At least 37 records · Page 2Linked to original sources
PubMed1977

Absence of mitochondrial terminal respiratory enzymes in cartilage matrix vesicles.

This study attempted to detect evidence of mitochondrial terminal respiratory components in matrix vesicles isolated from rachitic rat tibial epiphyseal plates. Biochemical assays for cytochrome c oxidase, NAD isocitrate dehydrogenase, NADP isocitrate dehydrogenase and succinate-cytochrome c reductase were negative. Polarimetric determinations revealed that the addition of succinate to matrix vesicles in suspension did not cause any increase in oxygen utilization. Spectrophotometric tracings of deoxycholate-solubilized matrix vesicles showed no characteristic absorption peaks or maxima belonging to any of the cytochrome complex components. Attempts to prepare pyridine hemochromes of cytochrome prosthetic groups from the matrix vesicles were also unsuccessful. The above results indicate that key components of mitochondrial respiratory systems are not detectable in rachitic matrix vesicles. The results are compatible with the interpretation that such vesicles are not derived from mitochondria.

Alkaline Phosphatase↗
PubMed1976

In vitro accumulation of mineral components by invertebrate cartilage.

In vitro mineralization of the gill cartilage of Limulus (horse-shoe crab) has been reported previously (Eilberg et al. 1975). The present study demonstrates that cranial cartilage of Loligo (squid) and odontophore cartilage of Busycon (marine snail) also mineralize in vitro in hydroxyapatite-metastable media, but not in carbonate-metastable media. In all three of these cartilages, light phase-contrast microscopy revealed that the mineral phase occured in the form of spherical or ovoid granules ranging between 2 and 9 mum in diameter. During mineralization, the granules appeared successively in the perichondrium, in the matrix, and finally, within chondrocytes. Mineralization occurred more rapidly in Eusycon odontophore cartilage which has a significantly higher content of phosphatidyl serine than in Limulus gill or Loligo head cartilages. In all tissues the mineralization process is related to temperature, taking place most actively at 37 degrees C and only weakly at 50 degrees C.

Animals↗
PubMed1975

The effects of cosmic particle radiation on pocket mice aboard Apollo XVII: appendix II. Evaluation of oral, dental, and skeletal tissues.

A sparse neutrophilic leukocytic infiltrate was found in the gingival sulcus, both in the flight and the control animals, while no changes were observed in the palate. Mitoses in gingival and palatal tissues were in approximately equal numbers in all animal groups. The tongues of flight mice and controls contained areas characterized by vascular dilatation, separation of muscle bundles, and regressive and degenerative changes in muscle fibers. Mucous glands in the posterior part of the tongue of flight and control animals exhibited acinar distension. Also examined were the vertebral column; femur, knee joint, tibia and fibula of the right hindlimb; and the tracheal cartilages. No evidence of cosmic ray particle effects was found in any of these tissues.

Animals↗
PubMed1974

Renal lysosomes: role in biogenesis of erythropoietin.

The "light" mitochondrial pellet obtained from the kidneys of rats previously treated with Triton WR-1339 and rendered hypoxic was separated into subcellular component fractions by sucrose density gradient centrifugation in a zonal rotor. Selected fractions were pooled, disrupted by osmotic lysis and repeated freeze-thawing, and incubated in the presence and absence of normal rat serum. The incubation mixtures were assayed for erythropoiesis-stimulating activity (erythropoietin). High specific activity was identified only in fractions rich in lysosomes. Biochemical analysis of reference enzymes for the identification of lysosomes and mitochondria, supplemented by electron microscopic examination of the various separated fractions, supports the observed requirement for lysosomal constituents in the formation of erythropoietin by the kidney.

Animals↗
PubMed1969

Cartilaginous dermal scales in cephalopods.

Epidermal scales of the squid Cranchia scabra are composed of tissue which stains metachromatically with toluidine blue, and which is similar in appearance to hyaline cartilage.

Animals↗