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Biomedical subjects

R W Burt

Publications and source records attributed to R W Burt.

At least 91 records · Page 5Linked to original sources
PubMed1984

Lasers in endoscopic gastrointestinal surgery.

Lasers have been used for endoscopic gastrointestinal surgery at our institution since 1977. The argon and Nd-YAG lasers are valuable for coagulating upper gastrointestinal hemorrhage, arteriovenous malformations, and benign and malignant lesions, as well as a variety of anatomic anomalies. Between December 1977 and September 1983, 222 procedures were performed in 122 patients. Hospital charts were reviewed and a scale constructed to assess the results of treatment. When information was available, a comparison of transfusion requirements before and after laser therapy was made. Success was achieved in 84 percent of the patients regardless of initial diagnosis. Laser therapy was not effective in 12 patients (10 percent). In 27 patients with gastrointestinal atrioventricular malformations, transfusion requirements fell from a mean of 17 +/- 5.9 units in the year before laser therapy to 1 +/- 0.8 units in the year after laser phototherapy (p less than 0.01). Complications rarely occurred (6 percent of all procedures). There were no perforations of the gastrointestinal tract and only one death (0.8 percent) partially attributable to laser application. Endoscopic laser surgery is minimally invasive and can be performed on an outpatient basis without anesthesia. It is especially valuable in patients with a high operative risk.

Adult↗
PubMed1984

In-111 granulocyte response to intervening surgery. Evidence of sustained in vivo viability.

A patient with chronic osteomyelitis had surgery performed between the early and delayed images of an In-111 granulocyte scan. The early images showed no uptake, while the delayed images demonstrated marked soft tissue uptake, which was felt to be secondary to the inflammation of the intervening surgery. It was concluded that granulocytes, when labeled with In-111, remain viable and can respond to inflammation that occurs after their injection.

Adult↗
PubMed1984

Leg perfusion evaluated by delayed administration of thallium-201.

Lower limb perfusion was evaluated with intravenous Tl-201 and angiography. Tl-201 was injected about 4 minutes after the cessation of stress; this resulted in increased uptake in muscles supplied by stenosed vessels. These results differ from previous studies and emphasize that differing results will be obtained with variations in the time of Tl-201 injection. Redistribution images are unchanged when Tl-201 is administered in this manner.

Adult↗
PubMed1984

Evaluation of complicating osteomyelitis with Tc-99m MDP, In-111 granulocytes, and Ga-67 citrate.

Studies with gallium-67 and three-phase bone imaging (TPBS), though very sensitive, are not very specific in evaluating suspected osteomyelitis (OM) that is superimposed upon other diseases causing increased bone turnover. A total of 57 patients with suspected OM were studied; this included 48 with increased bone turnover. All of the patients were studied with granulocytes labeled with In-111 acetylacetone (In-111 GRAN), TPBS and 29 of these patients had Ga-67 studies as well. In-111 GRAN had a sensitivity of 100% in acute OM and 60% in chronic OM, with a specificity of 96%. Gallium-67 was excellent in ruling out OM when the study was normal, or in ruling in OM when the relative uptake of Ga-67 exceeded the uptake of Tc-99m MDP, or when the Ga-67 in bone had a different distribution from the TPBS. Unfortunately, these criteria were met in only 28% of our subjects. We conclude that when added to TPBS, the In-111 GRAN study plays an important role in detecting complicating OM.

Acute Disease↗
PubMed1984

Upper gastrointestinal polyps in Gardner's syndrome.

Upper gastrointestinal polyps have been considered an uncommon finding in patients with Gardner's syndrome and familial polyposis coli. Investigators from Japan, however, have recently reported finding gastric and duodenal polyps in a high percentage of Japanese patients with these conditions. We endoscopically examined 11 affected members of the originally described Gardner's syndrome kindred to determine if upper gastrointestinal polyps also occurred in patients with Gardner's syndrome living in the United States. Six of the patients were found to have numerous small polyps of the gastric fundus and body. Polyp histology in 5 of the 6 patients was consistent with fundic gland hyperplasia. Biopsy specimens from the remaining patient demonstrated normal mucosa only. Another patient with no fundic polyps had a single antral polyp that was an adenoma. Eight patients exhibited small polyps of the duodenum. Biopsy specimens were obtained in 7 of the 8. All polyps biopsied were adenomas. The terminal ileum was examined by endoscopy in 9 of the 11 study patients. All 9 had ileal polyps, but the polyps were adenomas in 6 patients and lymphoid aggregates in 3 patients. The results indicate that upper gastrointestinal polyps are a common pleiotropic manifestation of the genetic defect responsible for Gardner's syndrome.

Adenoma↗
PubMed1984

Classification and risk assessment of individuals with familial polyposis, Gardner's syndrome, and familial non-polyposis colon cancer from [3H]thymidine labeling patterns in colonic epithelial cells.

A probabilistic analysis has been developed to assist the binary classification and risk assessment of members of familial colon cancer kindreds. The analysis is based on the microautoradiographic observation of [3H]thymidine-labeled epithelial cells in colonic mucosa of the kindred members. From biopsies of colonic mucosa which are labeled with [3H]thymidine in vitro, the degree of similarity of each subject's cell-labeling pattern measured over entire crypts was automatically compared to the labeling patterns of high-risk and low-risk reference populations. Each individual was then presumptively classified and assigned to one of the reference populations, and a degree of risk for the classification was provided. In carrying out the analysis, a linear score was calculated for each individual relative to each of the reference populations, and the classification was based on the polarity of the score difference; the degree of risk was then quantitated from the magnitude of the score difference. When the method was applied to kindreds having either familial polyposis or familial non-polyposis colon cancer, it effectively segregated individuals affected with disease from others at low risk, with sensitivity and specificity ranging from 71 to 92%. Further application of the method to asymptomatic family members believed to be at 50% risk on the basis of pedigree evaluation revealed a biomodal distribution to nearly zero or full risk. The accuracy and simplicity of this approach and its capability of revealing early stages of abnormal colonic epithelial cell development indicate potential for preclinical screening of subjects at risk in cancer-prone kindreds and for assisting the analysis of modes of inheritance.

Colonic Neoplasms↗
PubMed1983

Rheumatoid vasculitis of the colon presenting as pancolitis.

This report describes a patient with pancolitis resulting from rheumatoid vasculitis. Corticosteroid treatment reduced colonic inflammation but colectomy was required to control hemorrhage. The case illustrates the need to recognize colitis as a manifestation of rheumatoid vasculitis so that new treatment modalities may be employed to achieve a more successful medical management. The appearance of discrete colonic ulcerations following corticosteroid treatment of pancolitis in patients with rheumatoid arthritis should further suggest the diagnosis of intestinal vasculitis.

Arthritis, Rheumatoid↗
PubMed1982

Thallium-201 myocardial scintigraphy: improved sensitivity, specificity and predictive accuracy by application of a statistical image analysis algorithm.

Exercise and 3 hour delayed redistribution thallium-201 myocardial perfusion imaging was performed in 107 patients including 87 patients with documented coronary artery disease and 20 patients with normal coronary arteriograms. A computer algorithm for statistical analysis and redisplay of the analog scintillation data was developed to augment the visual analysis of the standard analog image. The basic algorithm identified the myocardial area (pixel) with the most absolute counts and developed an appropriate standard deviation range from a table. All pixels in the area of the myocardium containing absolute counts below three standard deviation ranges (or approximately 6 standard deviations) were deleted from the final image. The remaining pixels were redisplayed in a digitized bimodal format and the image photographed. Two experienced observers compared visual analysis of the analog image alone and the analog image in conjunction with the computer-analyzed image for sensitivity, specificity and predictive accuracy in the detection of perfusion defects in patients with coronary artery disease and in normal subjects. Sensitivity in patients with coronary artery disease and in normal subjects. Sensitivity in patients with coronary artery disease for the analog scintillation image alone was 79 percent (69 of 87) and with computer analysis 95 percent (83 of 87). Specificity in the patients with no coronary disease was 100 percent (20 of 20) for both techniques. The predictive accuracy of the test was 83 percent (89 of 107) for the analog image alone and 96 percent (103 of 107) for the two images combined. It is concluded that use of a computer statistical analysis algorithm of thallium-201 analog myocardial perfusion images improves the accuracy of detection of perfusion defects in patients with coronary artery disease.

Computers↗
PubMed1982

Endoscopic argon laser photocoagulation of small sessile colonic polyps.

The availability of flexible quartz wave ¿uides allowing introduction of argon laser energy through endoscopes suggests the possibility of ablation of colonic mucosal lesions by this technique. To ascertain the effects of the argon laser on the colon, penetration depth and perforation studies were conducted in dogs. At 250 joules/cm2 energy density, less than 50% muscularis externa injury was noted in 29 of 42 lesions. No perforation was noted. Healing was complete in 8 days. The time required for deliberate perforation with the catheter firmly pressed against the wall of a distended inflated colon using 2 W argon laser applied continuously was 41 +/- 13 sec, N = 53. In a human study of 15 small sessile polyps ablated by laser and the colon examined 4 days later at colectomy, no penetration of the laser beneath the submucosa was noted. In 11 patients with Gardner's syndrome 211 polyps have been removed in 18 treatments without complication. These encouraging results suggest the continued study of this endoscopic modality in the treatment of mucosal lesions of the colon.

Animals↗
PubMed1982

Imaging of brain tumors and other lesions utilizing Tc-99m phosphates and Tc-99m pertechnetate.

The intensity of parenchymal brain lesions was compared using Tc-99m pertechnetate and Tc-99m phosphate. The following conclusions were made: 1. If the Tc-99m phosphate intensity is greater than the intensity of the Tc-99m pertechnetate scan, and the patient is evaluated within four weeks of ictus, the lesion is a CVA (P less than .001). 2. If the Tc-99m phosphate intensity is less than or equal to the intensity of the Tc-99m pertechnetate scan, and the patient is evaluated within four weeks of ictus, the parenchymal lesion is not a CVA (P less than .001). 3. If the evaluation takes place longer than six weeks after ictus, then no evaluation about the nature of the lesion can be made based upon uptake of Tc-99m phosphate and Tc-99m pertechnetate.

Adult↗
PubMed1982

Scintigraphic evaluation of diabetic osteomyelitis: concise communication.

We have reviewed the three-phase bone scans, radiographs, and histologic findings of 39 diabetic patients with serious foot problems. The sensitivity and specificity of bone scans were 83% and 75%, respectively, for osteomyelitis of the small bones of the foot. The positive and negative predictive values were 87% and 69%, respectively. The radiographs were less sensitive (62%) and less specific (69%), with predictive values of 80% (positive) and 47% (negative).

Arthropathy, Neurogenic↗
PubMed1981

Comparison of CVA imaging with 99mTc phosphates, 99mTc pertechnetate, and computed tomography.

A retrospective study was made of 111 patients who underwent computed tomography (CT) and nuclear brain scans, with both pertechnetate and phosphate bone agents (PHOS), within 7 days of each other. Specifically, 78 patients who had a recent cerebral vascular accident (CVA) were compared. There were no significant sensitivity differences between the methods. While these studies appear complementary, the most important criterion is the time after onset when the studies were performed. The axiom "if the intensity of the phosphate scan exceeds that of the pertechnetate, the lesion must be a CVA" is true, only if the study is performed within 4 weeks of onset. The most economical method for optimum detection of CVA, with avoidance of frequent errors, is an early CT followed by a PHOS brain scan about 14 days after ictus in those that have initial negative CT.

Adult↗
PubMed1980

The clinical significance of the pattern of elevated serum carcinoembryonic antigen (CEA) levels in recurrent colorectal cancer.

Serial serum carcinoembryonic antigen (CEA) assays were performed in 148 patients after potentially curative surgery for colorectal cancer. Thirty-seven patients developed proved recurrent tumour in a follow-up period of 2-5 years. Elevated CEA levels were recorded in 36 of these patients and in 27 rising levels preceded clinical symptoms of recurrent tumour. Two distinct patterns of CEA rise were observed: a 'fast' rise in which serum concentrations reached 100 microgram/l within 6 months of the first elevation and a 'slow' rise in which concentrations remained less than 75 microgram/l for at least 12 months. The majority of patients with the 'fast' rise had metastatic spread, whereas most patients with a 'slow' rise had local recurrence alone. This differential pattern may help to predict the site of recurrent tumour.

Adenocarcinoma↗
PubMed1980

Gastrointestinal Polyposis: Syndromes and Genetic Mechanisms.

Adenomas and hamartomas, two genetically transmitted histologic types of gastrointestinal polyposis, are associated in syndromes with extragastrointestinal manifestations. Adenomas that predispose to adenocarcinoma are basic to familial polyposis coli, the Gardner syndrome and the Turcot syndrome. Gastrointestinal polyps and extragastrointestinal lesions serve as a warning, providing time for diagnosis and treatment of adenomas to prevent their malignant transformation in patients and their relatives. Hamartomas with no malignancy potential, but having a tendency toward bleeding and bowel obstruction, are associated with the Peutz-Jeghers syndrome, juvenile polyposis, multiple hamartoma syndrome, basal-cell nevus syndrome and the Cronkhite-Canada syndrome. Most of these lesions and syndromes follow the inheritance pattern of a single autosomal dominant gene.

Adenoma↗
PubMed1979

Evaluation of nuclear imaging for detecting posttransplant fluid collection.

A series of 26 renal allograft recipients studied by both B-mode gray scale ultrasonography and 99mTc DTPA renal nuclear imaging was reviewed. All conclusions were based on written reports generated at the original examination, and B-mode gray scale ultrasonography was considered the definitive examination for fluid collection detection. Sensitivity of nuclear imaging for the detection of fluid was 73%; however, it becomes 85% when fluid collections in close proximity to the bladder are excluded. Renal allograft nuclear imaging is a useful examination for primary detection of lymphoceles and also for demonstrating abnormalities in renal dynamics and drainage.

Body Fluids↗
PubMed1979

Infarction of renal allografts demonstrated by imaging with Tc-99m-DTPA.

The diagnosis of renal infarction on serial scintimages in renal allograft recipients is a relatively easy diagnosis. When the infarction is total or occupies a major portion of the kidney, the infarcted area will appear as photonpenic. Smaller infarctions will produce characteristic wedge shaped or oval defects along the kidney periphery. A possible source of error in interpretation is a recent biopsy procedure on the transplanted kidney.

Humans↗