Biomedical subjects

D W McCloskey

Publications and source records attributed to D W McCloskey.

6 recordsLinked to original sources

PubMed1992

Diagnosis of metastatic thymoma using flow cytometry.

Thymomas are cytologically benign epithelial neoplasms of the thymus gland. They compose 10% of mediastinal tumors, and are most common in the anterosuperior compartment. Seven to 36% of thymomas are malignant, as determined by tissue invasion, yet they metastasize in less than 3% of cases. Distinguishing lymphoma from lymphocyte-predominant thymoma is imprecise due to their histologic similarities. We present a 45-year-old man with intracranial metastatic thymoma. The lesion was interpreted radiographically as meningioma, and as possible lymphoma by frozen section. Flow cytometry proved this neoplasma to be a metastatic thymoma. Sixteen monoclonal antibodies were used to immunophenotype the CD45+ component of this tumor. Coexpression of CD4 and CD8 along with CD1 demonstrated lymphocytes of late cortical thymocyte origin; a second component was cytokeratin positive. This is the first reported case of extrathoracic metastases of thymoma diagnosed using flow cytometry. We propose this method as an invaluable technique to diagnose these histologically difficult neoplasms.

Aneuploidy↗

PubMed1990

Processing surgically removed lymph nodes.

Delicate lymph nodal tissue must be processed accurately and evaluated for proper patient management. In more than 125 cases at Methodist Hospital of Indiana, we devised a procedure that has allowed accurate diagnosis in 98% of cases. The pathologist's approach and the variety of studies necessary to confirm the diagnosis are presented, as well as important procedural considerations.

Diagnosis↗

PubMed1988

Immunologic monitoring of the cardiac transplant patient.

Peripheral blood lymphocyte morphology and cell surface markers were repeatedly evaluated in 49 orthotopic cardiac transplant patients over a period of three years to determine the utility of these parameters in predicting an episode of acute cardiac rejection. Lymphocytes were measured with a calibrated microscope and termed "activated" if greater than 10 mu in diameter. If a patient demonstrated greater than 30 activated lymphocytes/cu mm, the same lymphocytes were stained with monoclonal antibodies directed to T-cell subsets and B cells. These findings were retrospectively correlated with endomyocardial biopsy results. Absolute numbers of T-cell subsets and B cells were analyzed via Student's t test to identify significant differences during acute cardiac rejection. Of 347 biopsy specimens, 47 demonstrated histologic features of acute cardiac rejection. Simultaneous immune activation of lymphocytes occurred with 33 of 47 samples, while another 51 episodes of lymphocyte activation were detected without acute rejection. No statistically significant differences in absolute numbers of T-lymphocyte subsets were noted at the time of acute rejection.

Acute Disease↗

PubMed1979

Neodymium-yag laser treatment of experimental canine gastric bleeding. Acute and chronic studies of photocoagulation, penetration, and perforation.

Determination of the efficacy and safety of endoscopic laser photocoagulation to control upper gastrointestinal bleeding is prerequisite to the general application of this treatment in humans. We studied photocoagulation hemostasis, penetration, and perforation produced by a 55-W neodymium-yag (Nd:YAG) laser to control standardized experimental gastric bleeding lesions in a heparinized canine model. Photocoagulation of bleeding lesions was 100% successful with an application time of 3.56 +/- 1.65 sec (mean +/- SD). Histologic examintion of the gastric wall revealed a depth of injury to the muscularis externa of 40-100% with greater than 2 sec photocoagulation. Continuous photocoagulation exceeding 4 sec produced an 80-100% depth of muscle injury. Perforation of the gastric wall occurred after 9.6 +/- 1.5 sec, and all dogs studied after perforation survived. These studies indicate that Nd:YAG photocoagulation is an effective method to control experimental gastric bleeding lesions with a ratio between mean photocoagulation hemostasis and perforation times of approximatley 1:3. Further studies are required to define the implications of photocoagulation injury to muscle and the role of the gastric serosa in laser applications.

Animals↗

PubMed1978

Cell proliferation in esophageal columnar epithelium (Barrett's esophagus).

In order to correlate histopathology and cell turnover in esophageal tissue in patients with esophageal columnar epithelium, biopsy specimens from 11 patients were studied. Two of the patients had adenocarcinoma of the esophagus not present in the specimens studied. In the heterogeneous esophageal columnar epithelium, the DNA synthesis phase averaged 10.4 +/- 0.3 hr; labeling index of cells in the crypt-like structures was 23.3 +/- 0.3%; generation time was 44.6 +/- 1.2 hr, and the mitotic index was 1.82 +/- 0.07%. Significant differences were not present among specimens with columnar epithelium but they differed from cell proliferation in adjacent squamous epithelium where S phase was similar but labeling and mitotic indexes were lower and generation time increased to 105 +/- 6 hr. In the 2 patients with adenocarcinoma of the esophagus, and in 1 of 9 without adenocarcinoma, labeling of surface columnar cells after brief exposure to [3H]thymidine was present suggests that this may be a manifestation of early malignant change.

Adenocarcinoma↗

PubMed1976

Pneumonia in the neonate associated with group B streptococcal septicemia.

Fifteen newborns referred to the University of Utah Neonatal Intensive Care Unit (NICU) between 1971 and 1974 had septicemia and bronchopneumonia caused by streptococci of Lancefield group B. Eight of these infants could not be distinguished from others with idiopathic respiratory distress syndrome. All eight died and at autopsy were found to have bronchopneumonia. At autopsy, five of the ten subjects had bilateral pleural effusions. Eight of these early onset infections were caused by type III strains, three by type II strains, and four by Ia strains. The three survivors were infected by Ia organisms; two of these patients received antimicrobial therapy within one hour of birth and the other was treated at 20 hours of age. Among the 12 patients who died, six received no antibiotics and five were treated 12 or more hours after delivery. Earlier recognition may lead to more efficacious therapy of this most fulminant infection of the newborn.

Bronchopneumonia↗