PubMed HealthSearch

Biomedical subjects

C J Best

Publications and source records attributed to C J Best.

11 recordsLinked to original sources

Unusual presentation of acute upper airway obstruction caused by an anterior mediastinal mass.

We report an unusual case of acute upper airway obstruction. Inhalation of a foreign body caused choking in a 5-yr-old child, but subsequent investigations revealed a large anterior mediastinal tumour, externally compressing the trachea and the main bronchi. Such a presentation may be deceptive and is important, as general anaesthesia may result in complete airway obstruction with fatal consequences.

Airway Obstruction

Light microscopic immunocytochemical localization of hepatic and intestinal types of fatty acid-binding proteins in rat small intestine.

Monospecific antisera to purified hepatic fatty acid-binding protein (hFABP) and gut fatty acid-binding protein (gFABP) have been used to localize these two proteins in the small intestine of fed rats at the light microscopic level. Pieces of duodenum, jejunum, and ileum were removed from 4-, 10-, 20-, 22-, and 60-day-old Sprague-Dawley rats. Both cryostat and paraffin sections were studied for the presence of hFABP or gFABP by the avidin-biotin immunoperoxidase method. Slides were graded blind for the intensity of staining. Despite the structural and immunological differences between these two proteins, we showed no major differences between their staining patterns or their staining intensity throughout the intestine during postnatal development. The staining for both fatty acid-binding proteins was cytoplasmic. No brush border staining was found. Staining was more intense in the proximal rather than distal intestine, in the villus rather than crypt cells, and in the apex rather than the base of intestinal cells. Shifts in staining patterns, and staining intensity occurring during development may be related to variations in dietary fat intake, rates of cell proliferation, intestinal anatomy, and mechanisms for fat absorption.

Animals

Scanning electron microscopic appearance of chronic ulcerative colitis with and without dysplasia.

This study was conducted to determine whether scanning electron microscopy of colonic mucosal biopsy specimens can help to detect dysplasia in patients with chronic ulcerative colitis. In the first phase of the study, using light microscopy as the standard for the diagnosis, the scanning electron microscopic appearance of specimens from patients with chronic ulcerative colitis and control patients was examined. Descriptive criteria were established to identify normal, atrophic, and dysplastic colonic mucosa. In the second phase, quantitative techniques were used to develop more objective criteria for the diagnosis of dysplasia in ulcerative colitis. Twenty-one coded colonic specimens from 11 patients were sequentially examined by scanning electron microscopy and by light microscopy. The three morphometric analyses performed on the surface epithelial cells were number of cells per unit area, number of microvilli per unit area, and percentage of microvilli with a normal width. The cell count and percentage of microvilli with a normal width were significantly reduced in the seven specimens with colonic dysplasia as compared with non-dysplastic tissues. Scanning electron microscopy may serve as an adjunct to light microscopy in the diagnosis of colonic dysplasia.

Atrophy

Distribution of immunoreactive alkaline phosphatase in the adult rat ileum by immunoperoxidase staining at the light microscopic level.

Our prior immunocytochemical studies using monospecific antibody to alkaline phosphatase, Bouin's fixation, and paraffin sections demonstrated a decreasing gradient of villus brush border staining from the proximal to the distal rat small intestine. In addition, we noted an unusual pattern of staining in the terminal centimeter of the adult rat ileum: the villus brush border staining was less intense than crypt brush border staining. To determine whether this pattern of staining was present throughout the entire ileum, we examined alkaline phosphatase staining in two separate jejunal sites and the entire lowest third of the intestine of adult Wistar rats. With Bouin's fixation and paraffin embedding, both conventional and germ-free rats showed the same unusual staining pattern throughout the entire ileum. This pattern suggested that bacterial proteases were not responsible for the diminished ileal brush border alkaline phosphatase. However, when acetone fixation and cryostat sections were used with the avidin-biotin-peroxidase complex system, the previously noted reversed gradient of staining between the ileal villus and crypt areas was no longer present. Rather, ileal crypt brush border staining was less than ileal villus brush border staining. With either methodology, jejunal villus brush border staining was significantly more intense than ileal brush border staining, whereas the deep crypt brush border staining was not significantly different between the two regions. The present study reinforces the need for a combination of methodologies in order to best and most accurately localize certain antigens with immunocytochemistry. It also confirms a decreasing proximal to distal gradient for villus brush border alkaline phosphatase despite similar deep crypt brush border staining throughout the small intestine.

Alkaline Phosphatase