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Biomedical subjects

T S Nelsen

Publications and source records attributed to T S Nelsen.

At least 19 recordsLinked to original sources
PubMed1985

Thermal sensitivity to single and double heat treatments in normal canine liver.

The treatment of intrahepatic or perihepatic neoplasms by hyperthermia may be limited by the thermal sensitivity of normal liver tissue. To establish the temperature dependence of hepatic toxicity, eight canine liver lobes were exposed to a single 30-min dose of localized hyperthermia in the range of 43.0 degrees C-47.5 degrees C, induced by radiofrequency currents. Four additional liver lobes were conditioned with a pretreatment dose of 43.0 degrees C/30 min and challenged at either 44.5 degrees C/30 min or 47.5 degrees C/30 min, 4 h later. Temperature distributions were measured using implantable thermocouple sensors. Treated areas were sampled 28 days later, and liver damage was determined using histopathological criteria. Most treated sites showed only modest alterations. The parameters of tissue injury that correlated best with dose were: evidence of hepatocyte loss; focal fibrosis; and distortion of lobular architecture. Areas of necrosis were observed in several samples, but their presence or severity did not correlate with dose. Thermal damage to liver capsule, liver lobules, portal areas, and central veins did not exhibit monotonic dose-response relationships. The data do not demonstrate thermotolerance; in fact, they suggest, although do not prove, its absence. If thermotolerance did not develop, vascular effects might explain such a finding.

Animals↗
PubMed1977

Clinical and surgical (laparotomy) evaluation of patients with non-Hodgkin's lymphomas.

A consecutive unselected series of 423 patients with non-Hodgkin's lymphomas was staged prospectively at the Stanford Medical Center between June 1971 and June 1976. The histopathologic classification of Rappaport was used exclusively. Staging laparotomies were performed in 197 of the patients, but another 226 patients were excluded from the staging procedure for a variety of reasons, including stage IV involvement, poor surgical risk, and diagnostic celiotomy before referral to Stanford. Gastrointestinal, splenic, bone marrow, hepatic, and mesenteric lymph node involvement was very common in these patients, whereas systemic symptoms and mediastinal sites of disease were less frequently noted. After staging laparotomy, 15 patients (8%) were downstaged to a lesser extent of involvement while 62 (31%) were upstaged, primarily from clinical stage III to pathologic stage IV. Correlations were made between clinical and pathologic staging and the sites of involvement were compared between those with nodular and those with diffuse lymphomas. The accuracy of diagnostic radiologic procedures was also assessed. Although it is valuable in sequentially determining the extent of subdiaphragmatic involvement by lymphomas, we believe that staging laparotomy should still be regarded as a research procedure which will be undertaken only as indicated in centers of clinical research.

Adolescent↗
PubMed1977

Systemic air embolism in experimental penetrating lung injuries.

Several reports have described systemic air embolism in association with penetrating lung injuries. We produce lung lacerations in 18 dogs ventilated with air containing charcoal powder. An ultrasonic bubble detector was positioned over the carotid artery in six dogs. Evidence of arterial air embolism was found in every case of pulmonary laceration in open-chest, tension pneumothorax, and hypovolemic preparations. The quantity of air was small, producing only transient arrhythmia. No air was detected under control conditions. We conclude that systemic air embolism is a frequent accompaniment of penetrating lung injuries, that it is rarely recognized clinically because of its generally small quantity and minor, nonspecific effects, but that the potential for dangerous air embolism does exist with lung wounds and warrants precautions in management.

Animals↗
PubMed1976

Staging of Hodgkin's disease: a surgical perspective.

Staging laparotomy, consisting of splenectomy and biopsies of liver, lymph nodes, and bone marrow, is a very useful adjunct in the workup of a patient with Hodgkin's disease. In this series of 400 patients, 1.0 per cent required reoperations for complication, 3.7 per cent had major complications, and 14.0 per cent had minor complications from the operation. Further evidence of Hodgkin's disease was discovered in 42.0 per cent of the cases and a change from the clinical to the pathologic stage occurred in 27.5 per cent of these cases. The surgeon's task in the treatment of Hodgkin's disease and other malignant diseases is to document and mark the areas of involvement so that accurate and appropriate therapy can be given, while morbidity and mortality are minimized.

Biopsy, Needle↗
PubMed1975

Staging laparotomy with splenectomy in Hodgkin's disease.

Staging laparotomy, consisting of splenectomy and biopsies of liver, lymph nodes, and bone marrow, is a very useful adjunct in the workup of a patient with Hodgkin's disease. In this series of 400 patients, 1 percent required reoperations for complication, 3.7 percent had major complications, and 14 percent had minor complications from the operation. Further evidence of Hodgkin's disease was discovered in 42 percent of the cases and a change from the clinical to the pathologic stage occurred in 27.5 percent of these cases. The surgeon's task in the treatment of Hodgkin's disease and other malignant diseases is to document and mark the areas of involvement so that accurate and appropriate therapy can be given, while minimizing morbidity and mortality.

Biopsy↗