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P R Sweeny

Publications and source records attributed to P R Sweeny.

28 records · Page 2Linked to original sources
PubMed1972

Ultrastructural changes in muscular dystrophy. I. Cardiac tissue of piglets deprived of vitamin E and selenium.

The ultrastructure of cardiac tissue from neonate, 3-, 6-, 8-, and 12-week-old piglets, born of vitamin E- and selenium-deprived sows was studied. A progression of lesions occurred in nonmuscular components of this tissue; the first lesion appeared in connective tissue elements. Fibroblasts and the extracellular compartment appeared most severely altered in the neonate, and progressive vascular damage was very evident from 3 to 12 weeks of age. Similarly, neuronal elements appear altered at 3 weeks and were almost nonevident in areas showing marked lesions at 8 and 12 weeks. Fairly extensive alterations were evident in all of these elements before any marked changes become evident in the muscle. The relevance of these observations is discussed in relation to the etiology of the disease.

Animals↗
PubMed1972

Ultrastructure of muscular dystrophy. II. A comparative study in lambs and chickens.

The ultrastructure of the semitendonosus muscle of lambs and the pectoralis major muscles of chickens suffering from nutritional muscular dystrophy were studied. Samples of tissue from histologically normal and mildly degenerate areas were examined. Ultrastructural examination of areas that appeared apparently normal histologically, revealed lesions in the small vessels, connective tissue elements and neuromuscular elements. The possible relationship of these findings to the etiology of this disease are discussed.

Animals↗
PubMed1968

An electron microscopic study of the chorioallantoic membrane following infection with Rous sarcoma virus.

Infection of the chick chorioallantoic membrane (CAM) with Rous sarcoma virus (RSV) has been thought by earlier workers (12, 20) to result in the transformation of the ectoderm and then the mesoderm of that organ. In the present study, CAM were infected with 10(4) PFU (pock-forming units) of RSV (Bryan high titre strain) and collected for electron microscopy at 2, 4, and 6 days postinfection. Observations of the fine structural changes in the CAM after RSV infection support a singular role of the mesenchyme in the initiation of the tumors. The ectodermal hyperplasia often associated with RSV tumors of the CAM appears to be a secondary response to the alteration of the underlying mesenchyme. These findings are discussed in detail, and an alternate course of RSV transformation of the CAM by way of the vascular bed is suggested.

Animals↗
PubMedDate not supplied

Ultrastructure of the developing myotendinous junction of genetic dystrophic chickens.

This paper presents an ultrastructural study of the changes occurring within the tendon and at the insertion of the developing gastrocnemius of White Leghorn chickens and the dystrophic lines 413 and 423 from Davis, CA. The study revealed that the Davis lines contained abnormalities in these areas as early as 13 d in ovo with progressive deterioration to 19 d in ovo. The fibroblasts, collagen, and myofibers showed significant alterations as early as 13 in ovo. Fibroblasts contained abnormal mitochondria and altered Golgi bodies. At day 19, many were ruptured. The average diameter of collagen fibrils was smaller in the dystrophic chickens and myofibers showed a variety of alterations, some of which were severe. The details of these alterations are described and their possible relationship with the etiology of genetic muscular dystrophy is discussed.

Animals↗