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Biomedical subjects

W A Burns

Publications and source records attributed to W A Burns.

12 recordsLinked to original sources
PubMed1991

The severity of copper deficiency can be ameliorated by deferoxamine.

The present study was undertaken in order to determine whether hepatic iron overload plays a role in the exacerbation of copper deficiency. Weanling male Sprague-Dawley rats were fed a copper-deficient (0.6 microgram Cu/g) diet containing 62% fructose for 5 weeks. Some of the copper-deficient rats were injected daily with deferoxamine (DFX), an iron chelator that has been widely used to reduce iron overload. DFX reduced hepatic iron concentrations, which in turn ameliorated the pathology of copper deficiency when compared with nontreated copper-deficient animals. It is suggested that hepatic iron overload in a reduced environment plays a major role in the exacerbation of copper deficiency. Once the concentration of hepatic iron is reduced, the severity of the deficiency should be improved.

Animals↗
PubMed1979

Embedding in large plastic blocks. Diagnostic light and potential electron microscopy on the same block.

Specimens destined for light and electron microscopy were fixed in a modified buffered formalin, postosmicated, dehydrated, and embedded in a mixture of epoxy resins (Epon-araldite) in large plastic molds. These blocks were sectioned at 0.5 to 1 micron on a JB-4 microtome and stained with a combined nuclear and cytoplasmic stain (Paragon). The sections were examined by light microscopy for diagnostic evaluation. If ultrastructural examination was also desired, the selected area was isolated using the "mesa" technique. The trimmed block was then sectioned on an ultramicrotome, picked up on grids, stained, and examined in the electron microscope. We think these techniques offer the diagnostic pathologist the potential of viewing 1-micron sections at a light microscopy level with the option of subsequent electron microscopy of the same area of the same block.

Histological Techniques↗
PubMed1977

Lipolytic activity of human lingual glands (Ebner).

Human tongue preparations contain lipolytic activity similar to that present in human esophageal and gastric aspirates and in serous glands of rat tongue. The activity is present in homogenates of the glandular region (Ebner) beneath the cirumvallate papillae, and in secretions collected from the trough of the papillae. The lipolytic enzyme hydrolyzes long chain triglycerides to partial glycerides (di- and monoglyceride), glycerol, and free fatty acids at pH optimum 5.4. Lipolytic activity, expressed as nanomoles of triglyceride hydrolyzed per minute was in the range of 0 to 500 per gm. of tongue homogenate and 78 to 277 per ml. of aspirate from the vallate papillae. There was a 50% inhibition of the lipolytic activity by 4 mM sodium taurodeoxycholate. Specimens obtained from the region of the vallate papillae were examined by light and electron microscopy. Electron-dense granules similar to secretory granules present in rat Ebner's gland and in serous acini of human submaxillary glands were detected. Our findings suggest that in man, as previously reported in the rat, the lingual serous glands secrete a lipase that acts in the stomach where it initiates the digestion of dietary fat.

Exocrine Glands↗
PubMed1976

Quinidine hepatotoxicity. A report of a case and review of the literature.

A case is described of presumed quinidine hepatotoxicity, characterized by the development of fever, abnormal serum transaminase values, which improved after cessation of the drug but recurred after a challenge dose, and centrizonal hepatocellular necrosis detected on liver biopsy. Morphological changes on electron microscopy, consistent with a drug reaction, are also described. Pertinent features of previous case reports are analyzed, and the histological findings by light microscopy of the present and past cases are discussed. It is suggested that the development of unexplained fever within 1 month of quinidine administration should lead to consideration of possible hepatotoxicity.

Alanine Transaminase↗
PubMed1975

The clinician's view of diagnostic electron microscopy.

From the clinician's standpoint, it has become increasingly evident that use of the electron microscope should no longer be confined to research institutes, but should be applied as an adjunct to clinical diagnosis, a guide to therapy, and a means of elucidating pathogenetic mechanisms. The usefulness of electron microscopy is stressed in relation to hematology, nephrology, virology, gastroenterology, and the study of miscellaneous metabolic conditions such as the storage diseases.

Amyloidosis↗
PubMed1975

Education and training in electron microscopy.

There is currently a need for diagnostic electron microscopy in both autopsy and surgical pathology. As more information emerges from the research laboratories, applied electron microscopy will grow in depth, and all large medical centers will need the expertise provided by a diagnostic electron microscopy laboratory. Many physicians other than electron microscopists find it essential to have an understanding of the contributions and limitations of electron microscopy. Education and training programs therefore must encompass not only paramedical personnel who prepare the electron micrographs and pathologists who are thoroughly trained in interpret the electron micrographs, but also other physicians and scientists who utilize the information obtained therefrom. Medical students should obtain sufficient background in normal and abnormal ultrastructure to enable them to interpret the medical literature, and the means to obtain this background should be available within the medical school curriculum. Some medical students will also desire more thorough training obtained by elective courses in electron microscopy. Pathology residents should obtain sufficient expertise during their residency to enable them to utilize the information produced by the electron microscopy laboratory. Certain pathology residents and some pathologists in practice prefer fellowships for more specialized training in electron microscopy. Four representative training programs in electron microscopy from Veterans Administration hospitals have been selected for presentation. Each emphasizes a different approach and different objectives.

District of Columbia↗