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Biomedical subjects

C Kuntz

Publications and source records attributed to C Kuntz.

61 records · Page 4Linked to original sources
PubMed1981

VO2 max during progressive and constant bicycle exercise in sedentary men and women.

VO2 max, as obtained by five cycloergometric test protocols, was studied in 14 normal sedentary subjects: seven women (from 21--35 years) and seven men (from 21--48 years) who carried out four (n = 14) or five (n = 8) of the following exercise programmes: triangular tests, which consist of increasing the load (1) 20 W/min; (2) 30 W/3 min, rectangular tests at constant load; (3) the highest load which the subject could maintain for about 10 min (MSP + 20 W); (4) maximal supported power (MSP) during 20 min; (5) trapezoidal test, consisting of a rectangular exercise of 40 W (10 min), followed test no. 2. Exercises were performed on a cycle ergometer, while VE, VO2, VCO2, f and fH were continuously measured with an open circuit system. In women, the VO2 max (mean +/- SEM) was lower (36.5 +/- 2.1 ml . kg-1 . min-1) than in men (48.7 +/- 3.6 ml . kg-1 . min-1). The highest ventilation rate observed during exercise for the whole group (VE = 101 + 13 l . min-1) was always lower than the maximal voluntary ventilation (MVV = 144 +/- 131 . min-1, p less than 0.001). VO2 max strongly correlated with lean body weight, VC, FEV1, and MVV. In spite of the significant differences between the maximal load level sustained with the first three tests, the VO2 max values were not significantly different. Moreover, there exists an excellent correlation between them. It appears that neither the absolute load sustained in the tests, nor the duration nor intensity of the submaximal load which preceded the maximal level (tests 1, 2, and 5), influence the value of VO2 max.

Adult↗
PubMedDate not supplied

TNM staging of gastrointestinal tumors by hydrosonography: results of a histopathologically controlled study in 60 patients.

BACKGROUND: The study is a prospective evaluation of preoperative TNM staging of gastrointestinal tumors by hydrosonography (HUS). METHODS: Sixty patients with suspected gastric or colorectal cancer underwent HUS for TNM staging. All patients were operated on and the tumors completely removed when possible. HUS findings were correlated with histopathologic staging. RESULTS: HUS correctly localized tumors in 75% of patients. T stage accuracy was low for gastric cancers (41%). N staging of gastric cancers was accurate in 68% of all cases and was highly specific (100%). Staging was more accurate for colorectal tumors (70%), especially with respect to infiltration of other structures (sensitivity 100%, specificity 95%). N staging, however, was not reliable, mostly owing to impaired examination conditions. CONCLUSION: HUS easily misses tumors of the gastric cardia and distal part of the rectum. T staging of colorectal tumors with HUS is highly accurate, reaching 92% if the tumor is localized. T1 cancers of the stomach tend to be overstaged, and serosal infiltration by gastric cancers is often misjudged. With the exception of cardial gastric and distal rectal cancers, HUS comes close to endosonography for staging gastrointestinal tumors. HUS does not require intraluminal access.

Colorectal Neoplasms↗
PubMedDate not supplied

[Sun exposure and sun protection behavior and attitudes among the French population].

INTRODUCTION: The number of new skin cancers has constantly increased in France over the past two decades. The role of sun exposure can partly explain this phenomenon and justifies the development of information and prevention campaigns to change peoples' attitude towards sun bathing. To be effective, we need to know how much information and what attitudes the population currently has with regard to the sun. Although several studies in France have targeted children, little data is available regarding adults. This trial was aimed at pinpointing the knowledge, attitude and behavior of adults regarding sun exposure. MATERIAL AND METHODS: Data were collected during a randomized multicenter study on the prevention and early diagnosis of cutaneous tumors, conducted in 26 Health Centers from 1998 to 2000. Standardized questionnaires were handed to those consulting to assess their knowledge, attitudes and behavior towards sun bathing. The population was composed of 41 143 adults aged over 30, consulting one of the 26 Health Check-up units. Analysis of the data was made using SAS v 6.12 and STATA 7.0 software. Logistic regression identified the explicative factors of knowledge and behavior. All the statistical analyses were considered significant above a threshold of alpha<5%. RESULTS: A total of 33 021 persons filled-in the self-questionnaire. Forty-nine percent were women and 51% were men, with a mean age of 50 years. Geographically, 25% lived in the North-East, 16% in the North-West, 25 p.cent in the South-East and 34% in the South-West. Thirty percent claimed that they tanned without burning and 2% of the population studied had often suffered from sun burn, generally when they were adult. The risks related to sun burn were known, because 92% knew that the sun increased the risk of skin aging and 89% knew that it increased the risk of skin cancer. Regarding sun screens, knowledge was not so good; 42% thought that all products were the same and 53% that they allowed one to sun bathe longer. This knowledge was better in those with fair skins, in those who had a history of sun burn, in women and in those who lived in the northern areas of France. Conversely, knowledge decreased with age and was limited in those aged over 60. Regarding behavior, those with fair skin and who reddened under the sun without tanning, protected themselves more. The women declared they protected themselves more than the men, but they used less sun protective measures (clothing, hats...), other than sun screens, than men. Subjects aged over 60 protected themselves more than younger subjects. Lastly, a personal cutaneous history increased protective behavior, and those from northern France protected themselves more than those from the South. DISCUSSION: This analysis of 33 021 adults aged over 30 shows the good global knowledge of the consequences of sun bathing, but also the lack of knowledge on the interest of using external sun protection and the role of physical means of protection. Attitudes varied depending on gender, age and phototype and also depending on the area where they lived. Despite good knowledge, the most frequent behavior of adults aged over 30 is still not appropriate with differences depending on age, gender and area, which must prompt more appropriate targeting of prevention campaigns according to the populations concerned.

Adult↗
PubMedDate not supplied

MRI for staging of gastric carcinoma: first results of an experimental prospective study.

PURPOSE: Our goal was to define the accuracy of MRI in the staging of gastric carcinomas. METHOD: Twenty consecutive surgical specimens were imaged immediately after gastrectomy for gastric carcinoma. Imaging was performed with a 1.0 T imaging system. T1-weighted, T2-weighted, and opposed phase images were acquired and analyzed for tumor infiltration of the gastric wall and the presence of perigastric lymph nodes. T and N stages were classified according to the International Union Against Cancer classification. Finally histopathologic staging of the specimens was compared with staging by MRI. RESULTS: In gastric specimens, three to five layers of the gastric walls were visible. There were typical signal intensity patterns on T1-weighted, T2-weighted, and opposed phase images. Tumor diagnosis and lymph node detection were best achieved by opposed phase imaging. Nineteen of 20 (95%) carcinomas were localized by MRI; T staging accuracy was 65%. The sensitivity to detect metastatic lymph nodes was 87%, specificity 60%. N staging accuracy (nodes positive versus negative) was 80%. CONCLUSION: High resolution MRI of gastric tumors is possible ex vivo. MRI enabled differentiation of up to five layers of the gastric wall, and therefore staging of gastric carcinomas is technically possible. However, to evaluate the exact role of MRI as a staging tool of gastric carcinomas, a correlation between MR morphology and the histologic structure of the gastric wall has to be achieved first.

Carcinoma↗
PubMedDate not supplied

Helical hydro-CT for diagnosis and staging of gastric carcinoma.

PURPOSE: The purpose of this work was to define the accuracy of helical hydro-CT (HHCT) in the diagnosis and staging of gastric carcinoma. METHOD: One hundred twelve patients with gastric carcinoma were preoperatively imaged by HHCT. Gastric distension was achieved by ingestion of up to 1,500 ml of water. Bolus tracking was performed, and peristalsis was minimized by intravenously administered spasmolytics. Contrast material was then injected, and helical scanning was performed at the time of peak enhancement of the liver. CT images were analyzed for tumor infiltration of the gastric wall, and TNM staging criteria were applied according to the International Union Against Cancer (UICC) classification. The results were correlated with histopathologic findings. RESULTS: One hundred two of 115 (89%) gastric carcinomas were correctly diagnosed by HHCT. Small malignant ulcers (< or =2 cm) that corresponded to early gastric carcinoma were not visible on CT scans. T and N staging accuracies were 51% each; abdominal M staging was correct in 79% of all cases. The positive and negative predictive values of HHCT to foresee curative resection of gastric carcinoma were 75 and 84%, respectively. CONCLUSION: Mural thickening as well as marked contrast enhancement of the gastric wall are firmly related to gastric carcinoma. The accuracy of HHCT is acceptable for M staging but inadequate for local staging of gastric carcinoma. Nonetheless, HHCT is a useful guide for choosing between tumor resection and nonoperative treatment of patients. We therefore recommend HHCT as the method of choice for preoperative imaging of gastric carcinoma.

Adult↗