Substance abuse testing of urine by GC/MS in scanning mode evaluated by proficiency studies, TLC/GC, and EMIT.

Using GC/MS in scanning mode as a screening and definitive identification methodology for substance abuse testing, 4500 urine samples have been analyzed. The accuracy and sensitivity of this method was evaluated by the results of 92 proficiency sample analyses, reanalyses by TLC screening with GC confirmation of 125 samples from forensic sources and reanalysis by EMIT screening for seven groups of drugs confirmed by GC/MS of 590 samples from industrial and treatment sources. The results of these studies are presented.

Preparation of sputum smears for acid-fast microscopy.

A method is presented for the preparation of satisfactory smears for acid-fast microscopy that do not contain viable cells of Mycobacterium tuberculosis.

Paget's disease and melanoma of the vulva. Use of a panel of monoclonal antibodies to identify cell type and to microscopically define adequacy of surgical margins.

The ability of a panel of monoclonal antibodies generated in this laboratory to identify "pagetoid" melanoma cells and distinguish them from true Paget's adenocarcinoma cells in a retrospective analysis of vulvar neoplasms was investigated. Paraffin blocks of formalin and Carnoy's fixed tissue from 15 cases of vulvar Paget's disease and 11 cases of primary vulvar melanoma were retrieved and sections were incubated with the following panel of monoclonal antibodies: HMB45, a melanoma-specific monoclonal antibody; and 35 beta H11 and 34 beta E12, two different anti-cytokeratin monoclonal antibodies, to low molecular and high molecular weight cytokeratins, respectively. The anti-melanoma monoclonal antibody (HMB45) positively identified the melanoma cells, distinguishing them from normal melanocytes, in all 11 cases of melanoma. In contrast, the HMB45 antibody failed to react with the intraepithelial neoplastic cells in all cases of Paget's disease. These latter malignant cells were strongly positive only with the monoclonal anti-low molecular weight cytokeratin antibody 35 beta H11. This latter antibody absolutely distinguished tumor cells from neighboring uninvolved squamous epithelium, which was positive only with the monoclonal antibody 34 beta E12. Using this panel of monoclonal antibodies, the surgical margins could also be better evaluated; in at least one case the surgical margin thought by histological evaluation to be free of tumor was demonstrated by immunocytochemistry to be positive for tumor. In the vulvectomy specimens obtained in both diseases, Paget's or melanoma cells were identified in sections histologically interpreted as free of tumor. Thus, a panel of monoclonal antibodies is able to identify, with high sensitivity and specificity, vulvar melanoma cells and absolutely distinguish them from vulvar Paget's cells and can help in evaluating surgical margins in a more accurate manner.

Sonographic diagnosis of neutropenic typhlitis.

Five immunosuppressed patients with neutropenic typhlitis were studied with sonography. In four, sonography was the imaging technique that first suggested the diagnosis. In each case, sonography showed thickening of the right colon wall (1-2.5 cm) with low- or high-level echoes. Serial sonograms were used to monitor the daily progress of the disease in two patients. Sonography appears to be a useful tool not only to detect typhlitis in patients with symptoms suggestive of the disease, but also to follow their clinical course.

Colorectal tumors: scintigraphy with In-111 anti-CEA monoclonal antibody and correlation with surgical, histopathologic, and immunohistochemical findings.

A prospective clinical study of 17 patients with a histologic diagnosis of colorectal carcinoma proved at colonoscopy and surgery was performed with indium-111 anticarcinoembryonic-antigen (CEA) monoclonal antibody (MoAb), ZCE-025. MoAb scanning depicted nine of 16 primary colorectal carcinomas on planar scintigrams (true-positive findings = 56%) and ten of 16 lesions on single-photon emission computed tomography (SPECT) scans (true-positive findings = 62%). Liver metastases were detected in three of three patients, and lymph node metastases were detected in one of four patients. Immunohistochemical examination for CEA in resected colorectal cancer tissues demonstrated a positive correlation between MoAb imaging of primary lesions and cytoplasmic-stromal intracellular CEA distribution. There was no correlation between CEA serum levels and lesion detectability with MoAb scanning.