Value Of Routine Use Research Articles

Screening, diagnosis, and staging of non-small cell lung cancer and consideration of unusual primary tumors of the lungs.

Refinements of computed tomographic (CT) scanning techniques, such as high-resolution CT, CT densitometry, and contrast enhancement CT, have been shown to improve diagnostic accuracy in differentiating between benign and malignant lung nodules. Unfortunately, none of these techniques is fail proof, and, even when a lesion is considered to be benign, periodic observation is mandatory. In staging the locoregional extent of lung cancer, magnetic resonance imaging has not been shown to be superior to CT scanning and should not be substituted for or used in addition to CT except in special situations. Transesophageal ultrasonography, which identifies additional mediastinal lymph nodes that are not visualized by CT scanning, may become an important adjunct in the clinical staging of the regional extent of the disease. Study findings have supported the value of pleural lavage cytology at thoracotomy. Additional studies of the technique as a prognostic factor should be conducted in patients with resected early-stage disease. The high incidence of cerebral metastasis in patients with adenocarcinoma and stage III disease suggests the possible value of routine use of CT scans in this subset of patients who, otherwise, have potentially resectable lung tumors. However, no evidence supports routine scanning in patients with stage I or II disease. The low sensitivity of abdominal CT scans in identifying adrenal metastatic involvement further decreases the value of using this examination routinely to identify occult adrenal metastatic disease.

A simplified and rapid limiting dilution assay of T lymphocytes

We report here the development of an alternative limiting dilution assay (LDA) of T lymphocytes (T cells). Blood mononuclear cells were first stimulated for 60 hr with PHA and then cultured in microwells in the presence of recombinant interleukin-2 without feeder cells. After 4 days of culture, wells were scored for proliferation. Clonal expansion of T cells followed the single-hit model of the Poisson distribution. The progenitor frequency (φ) in the mononuclear cells and E-rosette-positive cells from normal donors were 0.082 ± 0.025 ( n = 12) and 0.236 ± 0.029 ( n = 5), respectively, but this was markedly decreased in patients who underwent marrow-ablative chemotherapy and autografts with blood hematopoietic stem cells. This LDA system should be of value in routine use for the evaluation of T cell proliferative activities.

AN EVALUATION OF ROUTINE OPERATIVE CHOLANGIOGRAPHY

The value of routine use of operative cholangiography was evaluated in 225 patients. In 65 patients (29%), there was one or more clinical or operative indications for common duct exploration and only 21 cases showed positive cholangiographic findings and were explored. There were four negative explorations in this group. In the remaining 160 patients who had no indication for common duct exploration, 157 had a normal cholangiogram and three had false positive cholangiographic findings and were explored unnecessarily. If operative cholangiography had been performed only on those patients with clinical or operative indications for common duct exploration, no ductal stone would have been missed. A selective use of operative cholangiography is advocated and the investigation should be restricted to those patients with clinical or operative indications for exploration of the common bile-duct.