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Biomedical subjects

W Pitts

Publications and source records attributed to W Pitts.

At least 19 recordsLinked to original sources

Keratin immunoreactivity as an aid to the diagnosis of persistent adenocarcinoma in irradiated human prostates.

Postirradiation prostatic biopsy is believed by many to be the best measure of radiation effectiveness in prostatic cancer. Therapeutic irradiation may induce prostatic glandular atypia, which in its severe form can be confused with persistent adenocarcinoma on prostatic biopsies. In the current study, 37 postirradiation prostate biopsy specimens were evaluated by immunohistochemistry using a specific monoclonal anticytokeratin antibody (KA1) that reacts with the basal cells of normal or hyperplastic glands, but is nonreactive with the lumenal cells or with prostatic carcinoma cells. Persistent carcinoma was observed in 19 cases in which antibody staining was absent. The noncarcinomatous glands retained reactivity, but this reactivity appeared in a new and previously undescribed pattern. The irradiated lesion was characterized by cellular pleomorphisism, with enlargement of nuclei and loss of polarity. The immunoreactivity was seen in the enlarged basal cells and was seen to focally extend to involve the lumenal cell layer. In five of 37 cases, glands were seen that were so atypical on the routinely stained sections that a distinction from cancer could not be made. These same glands in the adjacent section reacted with KA1 in each case allowing us to conclude that the changes were benign. We conclude that the interpretation of postirradiation prostatic biopsy specimens may be aided by immunohistochemistry with this anticytokeratin antibody.

Adenocarcinoma↗

Detection of acute radiation damage to the spleen in mice by using fluorine-19 MR imaging.

Previous work in our laboratory has shown that an IV-administered emulsion of perfluorooctylbromide, an agent known to localize in functioning macrophages in the reticuloendothelial system, can be detected in the liver and spleen by using fluorine-19 (19F) MR imaging. In mice that have received a single radiation dose of 1300 rad (13 Gy) (250 kVp) to the abdomen, relatively diminished uptake of perfluorooctylbromide emulsion in the spleen is seen as few as 12 days after irradiation when using 19F MR. When a GE NMR CSI 2-T spectroscopy/imaging system was used, 19F MR images were obtained in 2-16 min, and the postirradiation changes in the spleen were shown. This approach is the first that allows detection of acute postirradiation damage in the spleen in as few as 12 days and potentially allows assessment of macrophage dysfunction in vivo.

Acute Disease↗

19F magnetic resonance imaging of the reticuloendothelial system.

In this study sequential 1H and 19F magnetic resonance imaging methods were used to map the distribution of fluorinated compounds in vivo. An intravenously administered emulsion of perfluorooctylbromide (PFOB), an agent known to localize in the reticuloendothelial system, was detected in the liver and spleen of all studied hamsters and mice using 19F MRI. Lungs and salivary glands were also affected in some animals. Using a G. E. NMR CSI 2-T spectroscopy/imaging system, projection 19F images were obtained in 4 to 8 min. Subsequent mouse studies using a thick-slice driven equilibrium pulse sequence produced 19F images with an improved signal-to-noise ratio in a shorter acquisition time. With PFOB, 19F MRI has the capability of detecting macrophages in the reticulo-endothelial system and in other sites where macrophages congregate. This is the first report where the reticuloendothelial system was specifically imaged in live animals and where driven equilibrium imaging techniques have been applied to 19F MRI.

Animals↗

Smith-Lemli-Opitz syndrome in two 46,XY infants with female external genitalia.

Two infants with features of the Smith-Lemli-Opitz (SLO) syndrome were found to have a 46,XY karyotype and female external genitalia. Autopsies showed normal testes for age with normal Wolffian duct structures and without Müllerian duct derivatives. This failure of masculinization of the external genitalia is an unusual finding and may represent the extreme of a spectrum of the genital anomalies commonly seen in males with this autosomal recessive syndrome. An endocrine evaluation on one of these infants at 3 months suggested unusually low testosterone production and meagre response to stimulation with human chorionic gonadotropin (hCG). The failure of complete masculinization of external genitalia in some cases of SLO syndrome may be due to inadequate testosterone production in utero.

Abnormalities, Multiple↗