PubMed Health⌕ Search

Biomedical subjects

R W Burt

Publications and source records attributed to R W Burt.

103 records · Page 6Linked to original sources
PubMed1978

Thyroid function in lung cancer.

Thyroid function was assessed at the time of initial diagnosis in 204 patients with lung cancer and compared with that of age and sex-matched patients with non-malignant lung disease. Abnormalities in thyroid function were found in 67 patients (33%). The most prevalent abnormality was a low T3 concentration; this was not associated with other clinical or biochemical evidence of hypothyroidism, but the short-term prognosis of these patients was worse than that of matched patients with lung cancer having normal T3 concentrations. Primary hypothyroidism occurred in three patients, low T4 concentrations and free thyroxine index (FTI) with normal thyrotrophin (TSH) concentrations in four patients, and moderately raised TSH with normal thyroid hormone concentrations in six patients; nine patients had a raised FTI with or without raised T4 concentration as the sole abnormality.Overall, the pattern of thyroid hormone metabolism in lung cancer was a tendency towards reduced T3 concentrations with significantly increased T4/T3 ratios and modestly increased 3,3',5'-triiodothyronine (rT3) concentrations. The altered T4/T3 ratio was particularly noticeable in patients with anaplastic tumours of small ("oat cell") and large cell types, but was not apparently related to detectable extrathoracic metastases.These data suggest that thyroid hormone metabolism is altered in patients with lung cancer by decreased 5'-monodeiodination of T4. The resulting low T3 concentrations and altered T4/T3 ratio may be partly responsible for the reduced ratio of androsterone to aetiocholanolone observed in lung cancer, which is known to be a poor prognostic sign.

Adrenal Cortex Hormones↗
PubMed1978

Serum biochemical markers in lung cancer.

The prevalence of elevated serum levels of 5 potential tumour-associated antigens was determined in patients with lung cancer sampled at the time of initial presentation, using age- and sex-matched patients with benign lung disease as controls. Elevated levels (greater than upper 95th centile of controls) were found as follows: carcinoembryonic antigen (CEA), 17%; pregnancy-associated alpha-macroglobulin (PAM), 16%; casein 14%; human chorionic gonadotrophin (HCG) 6%; alpha-foetoprotein (AFP), 1.5%. The prevalence of elevated CEA levels (but not other markers) was higher in patients with evidence of extra-thoracic tumour spread (23%) mainly due to anaplastic tumours and adenocarcinomas. A degree of concordance of elevated marker levels occurred with CEA, HCG, casein and AFP, but there was a striking discordance of elevated CEA and PAM levels. Simultaneous assays of CEA and PAM will detect the majority of patients with elevations of any of the markers studied, and are likely to be the most useful biochemical markers in following the response of lung tumours to therapy.

Adult↗
PubMed1978

A critical comparison of the value of pregnancy-associated alpha2-glycoprotein and carcinoembryonic antigen assays in patients with colorectal cancer.

Absolute serum concentrations of pregnancy-associated alpha2-glycoprotein (alpha2-PAG) and carcinoembryonic antigen (CEA) were compared in 54 patients before and after surgery for colorectal cancer. Preoperatively, elevated levels of alpha2-PAG were found in 32 (59%) and of CEA in 35 (65%). Postoperatively, elevated alpha2-PAG levels were found in 10 of 18 patients (56%) without clinical evidence of recurrence whereas elevated CEA levels were present in three (16%). In patients who developed clinical evidence of tumour recurrence, alpha2-PAG levels were elevated in 8 of 13 (62%) while CEA levels were uniformly abnormal. It is concluded that, in this cross-sectional study, measurement of alpha2-PAG concentrations is less reliable than CEA in the detection of tumour recurrence after apparently curative surgery for colorectal cancer.

Adult↗
PubMed1977

Effect of ventilation images on observer interpretation of lung perfusion examinations.

Independent, random, and multiple evaluations by three observers of pulmonary perfusion scintiscans with and without ventilation scans demonstrated a 39% reduction in diagnosis of pulmonary embolism when ventilation scans were included. These findings suggest that four of 10 cases diagnosed as having pulmonary emboli on the basis of perfusion imaging procedures alone would have the diagnosis changed.

Humans↗
PubMed1975

Simultaneous determination of extracellular fluid and total body water. I.

A method for the simultaneous determination of extracellular fluid volume by radiosulfate-35 and total body water by tritiated water is described. Protein was precipitated from plasma with 10 per cent trichloroacetic acid. Radiosulfate-35 and tritiated water were counted in a dual-channel liquid scintillation spectrometer, using an automatic external standard to correct for quench. The sulfate space was calculated by the isotope dilution principle. Crossover counts contributed by radiosulfate-35 into the tritium channel were subtracted from the total counts in that channel. The tritiated water space was then calculated by the isotope dilution principle. Studies were performed in vitro and in 8 bilaterally nephrectomized rats. In vitro extracellular space by radiosulfate-35 and total body water by tritiated water demonstrated less than 3 per cent variation from the predicted volumes. In the rat, total body water determined with tritiated water demonstrated 4 per cent variation from that determined by desiccation. The method is simple, accurate, reproducible, and readily applicable for use in man and animals.

Animals↗
PubMed1975

Volume studies. II. Simultaneous determination of plasma volume, red cell mass, extracellular fluid, and total body water before and after volume expansion in dog and man.

A method for the simultaneous determination of plasma volume, red cell mass, extracellular fluid volume, and total body water is described. Plasma volume and red cell mass were determined by a standard dual gamma-tracer technique using 125radioiodinated labeled human serum albumin (125RISA) and 51radiochromate-tagged red cells (51Cr-RBC). Extracellular fluid volume and total body water were determined by a dual beta-tracer technique which utilized radiosulfate-35 (35SO4) and tritiated water (THO), respectively. Kinetic studies of each radionuclide in normal and fluid expanded states demonstrated equilibration of 125RISA and 51Cr-RBC in 5 minutes, 35SO4 and THO in 30 minutes. The results of the volume studies in dog and man demonstrated less than 10 per cent variation on repetitive study, and better than 70 per cent accuracy in estimating a known fluid change. This technique will enable a more precise and simplified investigation of the physiology of body fluid volume regulation in health and disease.

Animals↗
PubMedDate not supplied

Quantitation of colonic injury from argon laser, neodymium: YAG laser and monopolar electrocautery applied to flat mucosa and small sessile polyps of the canine colon.

This study determined the optimum laser energy for ablation of colonic mucosal lesions and small sessile polyps in the canine colon. Neodymium (Nd):YAG laser, argon laser, and monopolar electrocautery were applied to exposed canine colonic mucosa for various application times at various power settings. At the minimum energy level necessary to ablate mucosa, the Nd:YAG laser caused greater muscularis injury than the argon laser and monopolar electrocautery. At higher energy levels, monopolar electrocautery and Nd:YAG laser caused greater muscularis injury than argon laser. Small surgically created polyps in the canine colon were ablated endoscopically with the three energy sources. Single-session complete polyp ablation occurred most frequently with Nd:YAG laser and least frequently with argon laser. The depth of tissue injury beneath polyp ablation sites was least with argon laser and greatest with Nd:YAG laser. This study suggests that the argon laser is safer than the Nd:YAG laser or monopolar electrocautery for coagulation of flat colonic mucosal lesions. Although the argon laser is safer for the coagulation of small sessile colonic polyps, it may be less effective than monopolar electrocautery or the Nd:YAG laser for the single-session fulguration of polyps greater than 5 mm in diameter.

Animals↗