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Biomedical subjects

J E Craighead

Publications and source records attributed to J E Craighead.

At least 109 records · Page 6Linked to original sources
PubMed1975

Preparation of human lung biopsy specimens by perfusion-fixation.

A technique for perfusion-fixation of human lung biopsy specimens is described. The tissue is fixed in an expanded state by perfusing glutaraldehyde into cannulated blood vessels or bronchioles on the excisional surfaces. These specimens are ideally suited for histologic study and for both transmission and scanning electron microscopy.

Biopsy↗
PubMed1975

Long-term maintenance of differentiated respiratory epithelium in organ culture I. Medium composition.

Six commerically prepared, chemically defined media were tested in the presence and absence of serum to assess their influence on the maintenance of viable hamster respiratory epithelium over extended periods of time in vitro. Unique proliferation of epithelial elements was observed in organ cultures maintained in "complex" media containing serum, whereas use of these media in the absence of serum produced disorganized epithelial changes resembling squamous metaplasia. Minimum essential media at low serum concentrations preserved the columnar structure of the normal tracheal epithelium for 8 wk and longer in vitro.

Animals↗
PubMed1975

Cytoplasmic inclusions in pulmonary macrophages of cigarette smokers.

Alveolar and bronchiolar spaces in the lungs of cigarette smokers usually contain numerous macrophages with pigmented cytoplasmic granules. By electron microscopy the pigmentation appears to be due, at least in part, to increased numbers of lysosomes and phagolysosomes. Within these cytoplasmic organelles, structures are found which we designate "smokers' inclusions", since they are observed exclusively in the interstitial and alveolar macrophages of cigarette users. The inclusions have been referred to by other investigators as "needle-shaped" and "fiber-like". Since cross-sections of the structures are never seen in electron micrographs, a fiber or needle shape seems unlikely. On the other hand, thin sectioning techniques impart varying lengths to the inclusions, suggesting that they have a disc, or platelet, configuration. Surgically resected lung tissue from smokers and nonsmokers was digested in hot potassium hydroxide. Digestates contained varying numbers of hexagonal platelike particles which had features consistent with those of the aluminum silicate kaolinite, and energy-dispersive x-ray spectrometry confirmed the presence of these two elements. The origin of aluminum silicate inclusions in pulmonary macrophages has yet to be determined, although preliminary evidence strongly suggests that they are derived from inhaled tobacco smoke. The cytotoxicity of kaolinite in vitro and the possible role of aluminum silicate crystals in the pathogenesis of pulmonary fibrosis are discussed.

Aluminum Silicates↗
PubMed1974

Genetic influences affecting the occurrence of a diabetes mellitus-like disease in mice infected with the encephalomyocarditis virus.

The M variant of encephalomyocarditis virus produces a diabetes mellitus-like disease in DBA/2 mice but not in animals of the C3H strain. Fewer than one-third of infected F(1) (DBA/2 x C3H) progeny exhibit the disease, whereas the prevalence in backcrosses (F(1) x DBA/2, F(1) x C3H) is comparable to the parental inbred strain. Thus, the mode of inheritance of the diabetic predisposition appears to be polygenic. DBA/2 animals develop striking inflammatory and necrotizing lesions of the islets of Langerhans; in contrast, alterations of the insular tissue in the C3H mice are minimal. Although metabolic abnormalities appear to be consequent to lesions of beta cells, the factors influencing the severity of these insular changes are incompletely understood.

Animals↗
PubMed1974

Lesions of the islets of Langerhans in encephalomyocarditis virus-infected mice with diabetes mellitus-like disease. I. Acute lesions.

Mice infected with the M variant of the encephalomyocarditis (EMC) virus develop lesions of the islets of Langerhans associated with a diabetes mellitus-like disease. Ultrastructural alterations become evident in capillaries and beta cells at a time when large amounts of virus are present in the pancreatic tissue. Although some beta cells become necrotic, degranulation and contraction of intact cells is the prominent lesion. Changes in the capillaries appear early in the course of the infection and later are associated with interstitial fibrosis in and around the islets. During early convalescence, beta cells are degranulated and exhibit striking alterations of cytoplasmic organelles. These changes appear to be consequent to increased metabolic activity by the residual insular tissue. Interestingly enough, specific lesions of the alpha cells are not observed.

Acute Disease↗