Visual Data Analysis as an Integral Part of Environmental Management.

The U.S. Department of Energy's (DOE) Office of Environmental Management (DOE/EM) currently supports an effort to understand and predict the fate of nuclear contaminants and their transport in natural and engineered systems. Geologists, hydrologists, physicists and computer scientists are working together to create models of existing nuclear waste sites, to simulate their behavior and to extrapolate it into the future. We use visualization as an integral part in each step of this process. In the first step, visualization is used to verify model setup and to estimate critical parameters. High-performance computing simulations of contaminant transport produces massive amounts of data, which is then analyzed using visualization software specifically designed for parallel processing of large amounts of structured and unstructured data. Finally, simulation results are validated by comparing simulation results to measured current and historical field data. We describe in this article how visual analysis is used as an integral part of the decision-making process in the planning of ongoing and future treatment options for the contaminated nuclear waste sites. Lessons learned from visually analyzing our large-scale simulation runs will also have an impact on deciding on treatment measures for other contaminated sites.

Pathological validity of esophageal endoscopy. How real is what we see? Myth or reality?

The purpose of this study was to characterize the spectrum of esophageal pathology at a provincial tertiary care hospital and to evaluate these findings with their respective endoscopic diagnoses. The pathology slides of 183 esophageal biopsies for the year 2000 were reviewed and classified as esophagitis, intestinal metaplasia, low or high grade dysplasia, adenocarcinoma, squamous cell carcinoma or normal. One hundred and fifteen cases (63%) had complete concordant results with respective endoscopic reports. Sixty-eight cases (37%) had discordant results with inaccurate recognition of Barrett's esophagus in 9% and of esophagitis with a false positive in 16% and false negative in 7%. Although esophagoscopy remains a primary investigative tool in gastroesophageal diseases, evaluation of erythema, inflammation and esophagitis can be misleading. Pathologically confirmed esophagitis can occur in a 'normal' esophagus. Accurate endoscopic recognition of short-segment Barrett's remains a diagnostic challenge.

Squamous cell carcinoma of the prostate. A report of 6 cases.

Squamous cell carcinoma of the prostate is uncommon. In an attempt to assess the incidence of squamous cell carcinoma of the prostate, we searched the records of the Saskatchewan Cancer Agency over the past 30 years. Using strict diagnostic criteria a total of 6 cases of pure squamous cell carcinoma among 13,497 cases of prostatic carcinoma were identified. The ages of these patients ranged from 42 to 85 years. The survival rates of these cases ranged from 1 to 13 months.

Optimizing fluence and debridement effects on cutaneous resurfacing carbon dioxide laser surgery.

OBJECTIVE: To develop methods to compare carbon dioxide (CO2) resurfacing lasers, fluence, and debridement effects on tissue shrinkage and histological thermal denaturation. DESIGN: In vitro human or in vivo porcine skin samples received up to 5 passes with scanner or short-pulsed CO2 resurfacing lasers. Fluences ranging from 2.19 to 17.58 J/cm2 (scanner) and 1.11 to 5.56 J/cm2 (short pulsed) were used to determine each laser's threshold energy for clinical effect. Variable amounts of debridement were also studied. MAIN OUTCOME MEASURES: Tissue shrinkage was evaluated by using digital photography to measure linear distance change of the treated tissue. Tissue histological studies were evaluated using quantitative computer image analysis. RESULTS: Fluence-independent in vitro tissue shrinkage was seen with the scanned and short-pulsed lasers above threshold fluence levels of 5.9 and 2.5 J/cm2, respectively. Histologically, fluence-independent thermal depths of damage of 77 microns (scanner) and 25 microns (pulsed) were observed. Aggressive debridement of the tissue increased the shrinkage per pass of the laser, and decreased the fluence required for the threshold effect. In vivo experiments confirmed the in vitro results, although the in vivo threshold fluence level was slightly higher and the shrinkage obtained was slightly lower per pass. CONCLUSIONS: Our methods allow comparison of different resurfacing lasers' acute effects. We found equivalent laser tissue effects using lower fluences than those currently accepted clinically. This suggests that the morbidity associated with CO2 laser resurfacing may be minimized by lowering levels of tissue input energy and controlling for tissue debridement.

High basal gastric acid secretion in somatostatin receptor subtype 2 knockout mice.

BACKGROUND & AIMS: Somatostatin receptor subtype 2 (sst2) agonists inhibit gastric secretion. The role of sst2 in the regulation of acid secretion was assessed using sst2 knockout mice and urethane to induce somatostatin release. METHODS: Acid secretion was monitored every 10 minutes by gastric perfusion and backtitration of perfusates in fasted, urethane-anesthetized C57/129 sst2 (-/-) mice and wild-type (+/+) mice. The ileal vein was cannulated for drug injection. Intragastric pH and serum gastrin were monitored 1 hour after anesthesia without perfusion. RESULTS: Gastric pH values were lower in sst2 (-/-) mice (3.8 +/- 0.3) than in wild-type mice (7.1 +/- 0.1, P < 0.05), and there was no difference in gastrin levels. Basal acid output per 2 hours was 10-fold higher in sst2 knockout mice compared with wild-type mice. The gastrin antibody abolished the high basal acid secretion in sst2 (-/-) mice and had no effect in wild-type mice. The somatostatin antibody increased basal secretion by 4-fold in wild-type and had no effect in knockout mice. Somatostatin 14 or the sst2 agonist DC 32-87 inhibited pentagastrin-stimulated acid secretion in wild-type mice, but did not alter basal secretion in knockout mice. CONCLUSIONS: These results indicate that sst2 is the main subtype whereby endogenous somatostatin suppresses gastric acid secretion through inhibition of gastrin action.