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T Sutton

Publications and source records attributed to T Sutton.

At least 19 recordsLinked to original sources
PubMed2000

Histologic effects of holmium:YAG laser resection versus transurethral resection of the prostate.

BACKGROUND AND PURPOSE: Holmium laser resection (HoLRP) is an effective surgical alternative to transurethral resection of the prostate (TURP). We investigated whether an adequate histologic diagnosis could be made from HoLRP tissue specimens. PATIENTS AND METHODS: A series of 120 patients were randomized to TURP (N = 59) or HoLRP (N = 61). Each histologic specimen was reviewed by a single pathologist, who was blinded to the treatment. Weight of tissue, histologic diagnosis, and degree of thermal artifact were assessed. Thermal damage was graded as follows: 1 = no significant thermal injury; 2 = <25% of the tissue damaged (minimal); 3 = 25% to 80% of the tissue damaged (moderate); and 4 = >80% of the tissue damaged, with loss of prostatic architecture (extensive). RESULTS: The mean weight of the TURP and HoLRP specimens was 15.6 g and 9.6 g, respectively. The mean grade of thermal artifact for the TURP group was 1.8 and for the HoLRP group 2.6. Of the HoLRP specimens, 56 (92%) were grade < or = 3. Of the entire series of 120 specimens, 5 contained malignant tissue, all of which were from the TURP group. Four of these specimens were adenocarcinoma of the prostate, whereas the other was a transitional-cell carcinoma. Of the four specimens that contained prostate cancer, two were stage pTla tumors. CONCLUSIONS: Although identifiable prostatic architecture was maintained in the majority of histologic specimens from the HoLRP group, the tissue quality was inferior to that of TURP. There was significantly more vaporization and subsequent tissue loss with HoLRP, and the thermal damage to tissue was greater.

Adenocarcinoma↗
PubMed2000

Evaluating the financial impact of clinical trials in oncology: results from a pilot study from the Association of American Cancer Institutes/Northwestern University clinical trials costs and charges project.

PURPOSE: Medical care for clinical trials is often not reimbursed by insurers, primarily because of concern that medical care as part of clinical trials is expensive and not part of standard medical practice. In June 2000, President Clinton ordered Medicare to reimburse for medical care expenses incurred as part of cancer clinical trials, although many private insurers are concerned about the expense of this effort. To inform this policy debate, the costs and charges of care for patients on clinical trials are being evaluated. In this Association of American Cancer Institutes (AACI) Clinical Trials Costs and Charges pilot study, we describe the results and operational considerations of one of the first completed multisite economic analyses of clinical trials. METHODS: Our pilot effort included assessment of total direct medical charges for 6 months of care for 35 case patients who received care on phase II clinical trials and for 35 matched controls (based on age, sex, disease, stage, and treatment period) at five AACI member cancer centers. Charge data were obtained for hospital and ancillary services from automated claims files at individual study institutions. The analyses were based on the perspective of a third-party payer. RESULTS: The mean age of the phase II clinical trial patients was 58.3 years versus 57.3 years for control patients. The study population included persons with cancer of the breast (n = 24), lung (n = 18), colon (n = 16), prostate (n = 4), and lymphoma (n = 8). The ratio of male-to-female patients was 3:4, with greater than 75% of patients having stage III to IV disease. Total mean charges for treatment from the time of study enrollment through 6 months were similar: $57,542 for clinical trial patients and $63,721 for control patients (1998 US$; P =.4) CONCLUSION: Multisite economic analyses of oncology clinical trials are in progress. Strategies that are not likely to overburden data managers and clinicians are possible to devise. However, these studies require careful planning and coordination among cancer center directors, finance department personnel, economists, and health services researchers.

Aged↗
PubMed1997

The relationship of root canal enlargement to finger-spreader induced vertical root fracture.

The purpose of this study was to assess the effect of lateral condensation forces on the development of vertical root fracture (VRF) in teeth that have undergone controlled, measured internal root reduction (i.e. canal preparation). Thirty-four straight-rooted maxillary anterior teeth were used. For each tooth a simulated PDL was fabricated from a uniform 0.15 mm layer of silicone impression material. The teeth were mounted in resin to facilitate removal for observation. They were radiographed and measured at 2, 4, 6, and 8 mm from the apex. They were prepared with the step-back method so that the canal width was 20% of the total root width at 2, 4, 6, and 8 mm from the apex. They were obturated using a fine finger spreader attached to a jig that produced a static force of 3.3 kg for 15 s after placement of each gp point. Obturation was complete when the spreader did not penetrate apical to 8 mm from the apex. Twenty-four h after obturation the teeth were examined by transillumination for VRF. Teeth not exhibiting VRF were tested further after gp removal and canal enlargement of 30%, 40%, and 50% The teeth were sectioned at 2-mm increments with a diamond wafering saw and examined under stereomicroscope. No VRF occurred at 20% or 30%; 5 teeth fractured at 40% and 7 at 50%. These teeth had root surface craze lines that developed during testing. Craze lines had also developed in all 17 of the remaining unfractured samples. No VRF occurred after testing unless craze lines were previously present.

Humans↗
PubMed1997

Venturi vacuum systems for hypobaric chamber operations.

Physiological studies of the effects of high altitude on man often require the use of a hypobaric chamber to simulate the reduced ambient pressures. Typical "altitude" chambers in use today require complex mechanical vacuum systems to evacuate the chamber air, either directly or via reservoir system. Use of these pumps adds to the cost of both chamber procurement and maintenance, and service of these pumps requires trained support personnel and regular upkeep. In this report we describe use of venturi vacuum pumps to perform the function of mechanical vacuum pumps for human and experimental altitude chamber operations. Advantages of the venturi pumps include their relatively low procurement cost, small size and light weight, ease of installation and plumbing, lack of moving parts, and independence from electrical power sources, fossil fuels and lubricants. Conversion of three hyperbaric chambers to combined hyper/hypobaric use is described.

Altitude↗
PubMed1996

beta-Amyloid-mediated vasoactivity and vascular endothelial damage.

Deposits of beta-amyloid are apparent in ageing and Alzheimer's disease, but the role of this peptide in neurodegeneration is unclear. The free-radical theory of ageing may also account for Alzheimer-type degeneration and consequently links between free-radical generation and beta-amyloid have been sought. We demonstrate here that beta-amyloid interacts with endothelial cells on blood vessels to produce and excess of superoxide radicals, with attendant alterations in endothelial structure and function. The superoxide radical can scavenge endothelium-derived relaxing factor and produce potent oxidizing agents, which can cause lipid peroxidation and other degenerative changes. The alterations in vascular tone and endothelial damage are prevented by the oxygen-radical-scavenging enzyme superoxide dismutase. These observations suggest a normal vasoactive role for beta-amyloid as well as a mechanism by which beta-amyloid may play a role in vascular abnormalities and neurodegeneration mediated by free radicals.

Acetylcholine↗
PubMed1996

Diagnostic accuracy of stereotactic core biopsy in a mammographic breast cancer screening programme.

Stereotactic core biopsy was performed on 200 women for 206 mammographically suspicious non-palpable lesions detected over a period of 2 years as part of the Australian national programme for early detection of breast cancer. This study aimed to assess the reliability of stereotactic core biopsy in this context and to develop a protocol for the evaluation of stereotactic core biopsy in mammographically detected non-palpable breast lesions. Fifty-one of 52 malignant lesions found by stereotactic core biopsy were confirmed by excision biopsy (one women declined excision). Nine (4.5%) women had atypical ductal hyperplasia on stereotactic core biopsy; at excision, six were low grade carcinomas (in situ or invasive carcinomas), one was a 3 mm focus of grade 3 invasive duct carcinoma, one was atypical ductal hyperplasia, and one patient refused excision biopsy. In 29 (14.5%) women the histology of the stereotactic core biopsy was considered not to correlate with the radiological abnormality, and excision biopsy was advised: in four of these women carcinomas were found. One hundred and ten (55%) women had 116 benign lesions on stereotactic core biopsy: on follow-up, one of these patients has been found to have a carcinoma. Core biopsy number and sequence were analysed demonstrating that no particular biopsy was more diagnostic than any other, and that the diagnostic yield of three cores was statistically equal to that of five cores. The procedure was well-tolerated and there were few complications. Thus, stereotactic core biopsy is an accurate and safe method for diagnosis of mammographically detected non-palpable breast lesions, and we believe it is the diagnostic technique of choice in breast cancer screening programmes. However, a stereotactic core biopsy diagnosis of atypical ductal hyperplasia requires excision biopsy since a diagnosis of low grade intraduct carcinoma cannot be excluded. Furthermore, if tissue obtained by stereotactic core biopsy does not correlate with the mammographic abnormality, excision biopsy should be performed.

Adult↗
PubMed1995

Cardiovascular pressures with venous gas embolism and decompression.

Venous gas embolism (VGE) is reported with decompression to a decreased ambient pressure. With severe decompression, or in cases where an intracardiac septal defect (patent foramen ovale) exists, the venous bubbles can become arterialized and cause neurological decompression illness. Incidence rates of patent foramen ovale in the general population range from 25-34% and yet aviators, astronauts, and deepsea divers who have decompression-induced venous bubbles do not demonstrate neurological symptoms at these high rates. This apparent disparity may be attributable to the normal pressure gradient across the atria of the heart that must be reversed for there to be flow patency. We evaluated the effects of: a) venous gas embolism (0.025, 0.05 and 0.15 ml.kg-1.min-1 for 180 min.); b) hyperbaric decompression; and c) hypobaric decompression on the pressure gradient across the left and right atria in anesthetized dogs with intact atrial septa. Left ventricular end-diastolic pressure was used as a measure of left atrial pressure. In a total of 92 experimental evaluations in 22 dogs, there were no reported reversals in the mean pressure gradient across the atria; a total of 3 transient reversals occurred during the peak pressure gradient changes. The reasons that decompression-induced venous bubbles do not consistently cause serious symptoms of decompression illness may be that the amount of venous gas does not always cause sufficient pressure reversal across a patent foramen ovale to cause arterialization of the venous bubbles.

Altitude↗
PubMed1993

Use of a disposable carbon dioxide detector with emergency intubation in a hyperbaric chamber.

Emergency intubation in a hyperbaric chamber can be complicated by the confined space, inadequate lighting and high levels of background noise. Inadvertent esophageal intubation may be difficult to recognize in these conditions. In more controlled settings such as the operating room, the detection of end-tidal carbon dioxide is the standard procedure for verifying proper placement of the endotracheal tube. Within a hyperbaric chamber, a capnograph may not be readily available for this purpose. We present a case report describing the use of a simple disposable colorimetric carbon dioxide detector for rapid verification of endotracheal tube position following emergency intubation in a hyperbaric chamber.

Adult↗
PubMed1991

Doppler detection of decompression bubbles with computer assisted digitization of ultrasonic signals.

Precordial Doppler ultrasonic monitoring is routinely used for detection of venous gas bubbles resulting from decompression in hypobaric or hyperbaric applications. Bubble scoring codes have been devised in an attempt to quantify the number of audible bubble signals heard over the background sounds of the cardiac cycle. The audio interpretation of these ultrasonic backscatter signals remains the most common method for decompression evaluation. We report on the use of an inexpensive, commercially available audio digitizer in conjunction with a personal computer to digitize Doppler bubble signals for visual and electronic evaluation. This device can be operated simultaneously with Doppler audio monitoring. Precordial and arterial Doppler recordings of gas bubbles were obtained from anesthetized dogs after intravascular infusion or following decompression. Additional evaluations were conducted on Doppler bubble recordings obtained from human decompression studies. The device can be used in real-time or for later signal analysis. Accompanying menu-driven software provides for numerous signal modification options and visual displays. This device can provide a simultaneous visual display of Doppler signals normally only available for audio evaluation.

Animals↗
PubMed1990

Comparative toxicology of temelastine. A novel H1 antagonist in dog, rat, and monkey.

The toxicity of temelastine 2-[4-(5-bromo-3-methylpyrid-2-yl)butylamino]-5-[(6-methylpyrid+ ++-3-yl) methyl]-4-pyrimidone a potent, selective, competitive histamine H1-receptor antagonist was examined in dogs and rats. The major toxicological response seen in the dog was marked, but intermittent and reversible, increases in the plasma activity of a number of liver-associated enzymes, viz alanine aminotransferase (ALT), glutamate dehydrogenase (GLDH), and alkaline phosphatase (ALP). The increases first seen in two male dogs treated for 30 consecutive days at a dose of 300 mg/kg became apparent at lower doses, i.e., 100 and 33.3 mg/kg/day, in 6- and 12-month studies. Although the increases were suggestive of hepatotoxicity, the only histological changes were increases in hepatocellular lipofuscin pigment and foci of macrophages seen in dogs treated at 300 mg/kg for 12 months. Rats treated for up to 12 months at doses as high as 300 mg/kg/day showed no treatment-related increases in plasma enzymes although increases in liver weights and hepatocellular lipofuscin pigment together with centrilobular hypertrophy were seen in the 300 mg/kg/day treatment group. To investigate differences in hepatic responsiveness between species dogs, rats, and monkeys were exposed to high concentrations of temelastine by continuous 24-hr intravenous infusion. The results of the study showed the dog to be most sensitive to the hepatic effects of temelastine. The major toxicological effect of temelastine in the rat was a histopathological lesion of the thyroid gland characterized by agglomeration and depletion of colloid, follicular epithelial hypertrophy and reduced follicular size. The no-effect dose for this lesion was between 10 and 33.3 mg/kg/day. These histopathological changes, characteristic of a "TSH-driven" thyroid gland, were not seen in the thyroid glands of dogs.

Alanine Transaminase↗
PubMed1988

Effect of the Trendelenburg position on the distribution of arterial air emboli in dogs.

We examined the effects of buoyancy on the distribution of arterial gas bubbles using in vitro and in vivo techniques in dogs. A simulated carotid artery preparation was used to determine the effects of bubble size and vessel angle on the velocity and direction of bubble movement in flowing blood. Because buoyancy tends to float bubbles away from dependent areas, bubble velocity would be expected to decrease as the vessel angle increased. We found that larger bubbles increased in velocity in the same direction as the blood flow at 0-, 10-, and 30-degree vessel angles and decreased when the vessel was positioned at 90 degrees. Smaller bubbles did not change velocity from 0 to 30 degrees and increased in velocity in the same direction as blood flow at 90 degrees. In 10 anesthetized dogs, we studied the effects of 0-, 10-, 15-, and 30-degree Trendelenburg's position on carotid artery distribution of gas bubbles injected into the left ventricle or ascending aorta. Regardless of the degree of the Trendelenburg position, the bubbles passed into the carotid artery simultaneously with passage into the abdominal aorta. We conclude that the forces of buoyancy do not overcome the force of arterial blood flow and that the Trendelenburg position does not prevent arterial bubbles from reaching the brain.

Animals↗
PubMed1987

Villous and tubulovillous adenomas of the colon and rectum. A retrospective review, 1964-1985.

The records of 1,040 patients with 1,440 villous and tubulovillous adenomas of the colon and rectum treated at the Cleveland Clinic over a 21 year period were reviewed. The incidence of invasive adenocarcinoma was higher in patients with multiple adenomas at the time of presentation, in patients with a family history of colorectal cancer, and in those with adenomas greater than 4 cm in diameter. Eighty percent of the adenocarcinomas were Dukes' A or B, 15 percent were Dukes' C, and 5 percent presented with distant metastases. Clinical impression on examination was more accurate than biopsy in assessing the presence of malignancy in these tumors. Recurrence after local treatment of both benign and malignant tumors was high. Recurrence was significantly related to the size of the adenoma (more common when the tumor was more than 4 cm in diameter), location (more common when it was located in the rectum), and the type of treatment. Only 4 percent of the patients had died from colorectal cancer at the time of follow-up. The overall 5 year actuarial survival rate was 85 percent.

Adenocarcinoma↗
PubMed1983

Unusual aspects of Kawasaki syndrome.

Kawasaki syndrome (mucocutaneous lymph node syndrome) occurs predominantly in children. The criteria for diagnosis include unresponsive fever; lesions of the skin and conjunctival mucous membrane; edema, rashes and other abnormalities of the hands and feet, and cervical lymphadenopathy. Unusual features occur in the cardiovascular, gastrointestinal and central nervous systems, as well as elsewhere. The variety of findings may be misleading, and the diagnostic criteria must be kept in mind.

Aspirin↗