Search PubMedSearch

Biomedical subjects

W D Bradford

Publications and source records attributed to W D Bradford.

9 recordsLinked to original sources

Asymptomatic cecal stenosis after necrotizing enterocolitis.

Survival of infants with necrotizing enterocolitis may be complicated by intestinal stricture(s) as a result of healing of ischemic segments of bowel. An asymptomatic cecal stenosis not visible on barium enema was identified at operation for reestablishment of intestinal continuity. Infants recovering from acute necrotizing enterocolitis deserve continued surveillance for mechanical and functional abnormalities of the gastrointestinal tract. Patency of the intestinal lumen distal to the ostomy site should be clearly demonstrated by the surgeon when continuity is reestablished.

Cecal Diseases

Kidney lesions in Rocky Mountain spotted fever: a light-, immunofluorescence-, and electron-microscopic study.

The essential pathologic lesion in Rocky Mountain spotted fever (RMSF) is a vasculitis that may involve the kidneys as well as the heart, brain, skin, and subcutaneous tissues. Histopathologic information concerning the response of the kidneys in RMSF is rather limited, however. In this study renal tissue from 17 children who died of RMSF was examined by light, electron, and immunofluorescence microscopy. A lymphocytic or mixed inflammation, or both, involving vessels and interstitium of the kidney was found in all patients. In addition, 10 patients had histologic evidence of acute tubular necrosis, and another 3 had glomerular lesions consisting of focal segmental tuft necrosis or increased cellularity secondary to neutophilic infiltration, or both. Immunofluorescence- and electron-microscopic studies failed to demonstrate immune-complex deposition within glomeruli, a finding that suggests that immunoglobulin and classic immune complexes were not involved in the pathogenesis of the renal lesions at the time of death. These findings suggest the possibility that the pathogenesis of the renal lesion in RMSF may be due to a direct action of the organism (Rickettsia rickettsii) on the vessel wall.

Adolescent

Myocardial involvement in Rocky Mountain spotted fever.

Rocky Mountain spotted fever (RMSF), an acute febrile exanthematous illness caused by Rickettsia rickettsii and transmitted by ticks, is endemic in the southern Atlantic states. This report is based on the clinical and pathological findings of myocardial involvement in 16 children who died with severe RMSF. All 16 children had myocardial lesions to some degree, but it was not believed that these could be evaluated in terms of cardiac function and death in the face of the usual peripheral vascular collapse caused by the widespread vascular lesions throughout the body.

Adolescent

Rocky mountain spotted fever in childhood.

Experience with 138 cases of Rocky Mountain spotted fever indicates that the major clinical features of characteristic rash, fever, and tick bite, in combination with low serum sodium concentration and thrombocytopenia, are helpful in recognizing this serious and potentially lethal infectious disease.

Adolescent

The impact of an elective curriculum in pathology.

Under the revised medical curriculum at Duke University, elective courses were offered in the third and fourth years beginning in 1968-1969. Departmental electives in autopsy, surgical, and systemic pathology were offered as major courses, and the subspecialty courses in cardiovascular, renal, pulmonary, pediatric, and neuropathology were taught by specialists in those areas. Special topics in subcellular and molecular pathology, neoplasia, environmental diseases, and experimental pathology were subscribed by medical and graduate students alike. To determine the impact of elective courses in pathology, these electives were compared to those offered by other basic science disciplines. Tabulation of total courses offered, student enrollment, and total academic credit hours were constructed for each basic science area. The data show that over the six year study period the students elected more courses in pathology than in any other basic science. The most heavily subscribed electives in pathology were those that were clinically oriented, such as cardiovascular or renal pathology. One impact of this elective system may be to enhance recruitment. During the period studied, 29 Duke graduates interned in pathology compared to six under a comparable time period in the traditional curriculum.

Curriculum

Cellular autophagocytosis induced by deprivation of serum and amino acids in HeLa cells.

Morphologic alterations in HeLa cells deprived of serum and amino acids were studied by light and electron microscopy. After complete deprivation for 1, 3, or 6 hours, many cells contained autophagic vacuoles enclosing clearly recognizable cell organelles. The proportion of cells showing autophagy rose from 4 to 37% in the first 3 hours of deprivation. Acid phosphatase reaction product was localized within many of the autophagic vacuoles by a modified Gomori method. After 12 to 24 hours of deprivation, many membranous residual bodies were noted within the starved HeLa cells. These electron microscopic studies indicate that complete deprivation of serum and amino acids provides a useful model for the further study of cellular autophagocytosis.

Amino Acids

Iron metabolism and cell membranes. III. Iron-induced alterations in HeLa cells.

The morphologic characteristics of acute iron loading were studied in HeLa cells incubated in an iron-enriched Eagle's medium containing 500 mug/ml of iron. Chemical studies showed that ferritin synthesis was rapidly induced and the concentration of intracellular ferritin increased up to 72 hours. Closely coupled with an increase in HeLa cell ferritin was a marked decrease in the rate of cell multiplication. The significant ultrastructural findings of iron-induced HeLa cell injury are characterized by the appearance of both autophagic multivesicular and residual bodies over the first 72 hours of iron incubation. The prominence of multivesicular bodies was noted after only 4 hours' incubation, with iron and myelin figures first appearing after 6 hours. Thus, the partial arrest of cell multiplication was associated with an increase in cytoplasmic residual bodies containing iron and other debris. The distribution of intracellular ferritin within HeLa cells differs significantly from the distribution described previously in hepatic parenchymal cells. In HeLa cells, ferritin particles were confined to lysosomal vesicles and were not identified in cell sap, endoplasmic reticulum, or Golgi apparatus.

Acid Phosphatase