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PubMed1990

The association of selected cancers with service in the US military in Vietnam. III. Hodgkin's disease, nasal cancer, nasopharyngeal cancer, and primary liver cancer. The Selected Cancers Cooperative Study Group.

As part of a series of investigations into the health of Vietnam veterans, we conducted case-control studies involving 310 men with Hodgkin's disease, 48 with nasal carcinoma, 80 with nasopharyngeal carcinoma, 130 with primary liver cancer, and 1776 controls between 1984 and 1988. All men born between 1929 and 1953 and diagnosed in an area covered by eight cancer registries were considered eligible as cases; controls were recruited by random-digit dialing. Whereas the study had excellent power (96%) to detect a twofold increase in risk for Hodgkin's disease among Vietnam veterans, its ability to detect a similarly elevated risk in the other cancers was limited, ranging from 38% (nasal carcinoma) to 75% (primary liver cancer). Analyses showed that risks among Vietnam veterans relative to other men were 1.1 (Hodgkin's disease), 0.7 (nasal carcinoma), 0.5 (nasopharyngeal carcinoma), and 1.2 (primary liver cancer). None of these relative risks was significantly different from 1.0. Similar results were obtained if Vietnam veterans were compared with (1) other veterans or (2) men who never served in the military. An examination of several attributes of military service in Vietnam (eg, branch, duration of service, and other characteristics that may have been associated with the use of Agent Orange) failed to identify any groups of veterans who were at increased risk for Hodgkin's disease. Small numbers limited further analyses of nasal, nasopharyngeal, and liver cancer. These results provide no evidence that, 15 to 25 years following service in Vietnam, the risk of these malignant neoplasms is higher among veterans.

Adult↗
PubMed1985

Bile composition and bile acid pool size. Comparison after truncal, selective, and highly selective vagotomy.

We studied biliary lipid composition and bile acid pool size in 29 patients surgically treated for duodenal ulcer. Fourteen were examined both before and after surgery, the rest postsurgically only. They were divided into three groups according to type of vagotomy. With duodenal fluid obtained via nasogastric tube, we determined bile acid pool size, bile concentrations, and lithogenic index. We found no significant differences in bile composition and bile acid pool size among the three types of vagotomy, postsurgically. However, patients studied before surgery, compared with the entire post-vagotomy group, had a significant increase in relative cholesterol content and lithogenic index, most pronounced in the truncal vagotomy group. Bile acid pool size was also increased postsurgically. Vagotomy may predispose to gallstone development by increasing the bile's relative cholesterol concentration and thus the lithogenic index. However, the slightly expanded bile acid pool size may improve cholesterol solubility in certain patients.

Bile↗
PubMed2005

How does DNA compaction favor chiral selectivity with cationic species? Higher selectivity with lower cationic charge.

A single-molecule study on giant DNA compaction by enantiomeric dications and tetracations demonstrates that strong chiral discrimination in DNA compaction is manifested only if the positive charge on enantiomeric multications is relatively low. The increase in cationicity of the chiral compaction agent inevitably leads to an increase in nonspecific electrostatic interactions and quenching of chiral discrimination in the DNA-folding phase transition.

Bacteriophage T4↗
PubMed1985

Habitat selection in larval anurans: early experience and substrate pattern selection in Rana pipiens.

The tadpoles of Rana pipiens, unlike those of other frogs that have been reported on, do not develop clear-cut perceptual preferences for familiar background patterns composed of either squares or stripes. When larvae reared on white and/or patterned backgrounds are tested for preference between these backgrounds, they all exhibited a preference for white backgrounds. When the larvae were tested for preference among uniform backgrounds of varying brightness, those reared on the two brighter backgrounds showed no preference, and those reared on the two darker backgrounds preferred the brightest of the available backgrounds. The larvae of R. pipiens behave as if they possess an experientially modifiable defense reaction such that, when frightened, they move preferentially onto brighter backgrounds and avoid boldly patterned backgrounds. A pattern may be less aversive if it is familiar than if it is unfamiliar. Larvae from South Dakota tended to habituate more effectively to striped backgrounds, and those from Wisconsin to backgrounds composed of squares.

Animals↗