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Biomedical subjects

J T Albright

Publications and source records attributed to J T Albright.

29 records · Page 2Linked to original sources
PubMed1976

Ultrastructural alterations in skeletal muscle fibers of streptozotocin-diabetic rats.

The ultrastructure of fast-twitch-oxidative-glycolytic (FOG), fast-twitch-glycolytic (FG) and slow-twitch-oxidative (SO) fibers in plantaris and soleus muscles of normal and streptozotocin-diabetic rats was studied. In the diabetic animals, the mitochondria of FOG and SO fibers showed a loss of cristae and an increase in electron-dense granules. There was also an increased number of lipid droplets in close proximity to the mitochondria and the nuclei, and a separation of individual muscle nuclei to form satellite cells. Higher incidences of surface projections and sarcoplasmic splittings at the nuclear region were noticed in SO fibers. The FG fibers showed some disorientation of the T-tubular system. It is concluded that streptozotocin-diabetes has differential effects on the fine structure of the three fiber types of rat skeletal muscle.

Animals↗
PubMed1975

The ultrastructure of the swimbladder of the toadfish, opsanus tau L.

The anterior chamber of the swimbladder of the toadfish Opsarmustau L. is lined by a single layer of columnar gas gland cells, cuboidal cells that resemble gas gland cells but are located outside of the gas gland region, and squamous cells. Multilamellar bodies are numerous in the gas gland cells and the cuboidal cells and are present in smaller numbers in the squamous cells. Capillaries lie in the lamina propria directly below the epithelial lining. A thick continuous muscularis mucosae and a submucosa consisting of tightly packed cells, cell processes, and connective tissue may contribute to the impermeability to gases of the wall of the anterior chamber. The posterior chamber of the swimbladder is lined by a single type of squamous epithelial cell. Multilamellar bodies were occasionally observed in these cells also. Other types of cells frequently form a partial second layer between the epithelial lining and the basement lamina. A thin muscularis mucosae lies directly below the basement lamina and the capillaries of the posterior chamber are located in the submucosa. The tunica externa is a layer of dense connective tissue that surrounds both the anterior and posterior chambers. Collagen fibrils in the form of tactoids are present in this layer.

Air Sacs↗
PubMed1969

Plastid development in albescent maize.

Plastid development in albescent (al/al) and wild-type (+/al) strains of Zea mays has been studied in the electron microscope. Etiolated seedlings of the mutant are severely deficient in colored carotenoid pigments and accumulate carotenoid precursors tentatively identified as phytoene and phytofluene. The fine structure of proplastids in etiolated wild-type and mutant leaves is similar with 1 notable exception. Osmiophilic bodies found in the wild-type were lacking in all sections of albescent proplastids examined suggesting that these structures may be storage centers for carotenoid pigments. Plastid pigments are destroyed, chlorophyll synthesizing potential is lost, and the ultrastructure of plastids is irreversibly altered when mutant seedlings are placed directly in high intensity light. However, synthesis of plastid pigments and development of the photosynthetic apparatus as seen in the electron microscope is normal, and indistinguishable from that in the wild-type, in seedlings of the albescent mutant preilluminated with low intensity light prior to high intensity illumination. During treatment in low intensity light carotenogenesis is initiated in the mutant and proceeds normally thereafter.

Journal Article↗