Spaceflight and development of immune responses.

The NIH.R1 Space Shuttle experiment was designed to study the effects of spaceflight on rodent development. Pregnant rats were flown on the Space Shuttle for 11 days, and pregnant control rats were maintained in animal enclosure modules in a ground-based chamber under conditions approximating those in flight. Additional controls were in standard housing. The effects of the flight on immunological parameters of dams, fetuses, and pups were determined. Blastogenesis of spleen cells in response to mitogen was inhibited in flown dams but was not inhibited in cells from their pups. Interferon-gamma production by spleen cells showed a trend toward inhibition in flown dams but not in their pups. The response of bone marrow cells to colony-stimulating factor showed a trend toward inhibition after spaceflight in dams, but the response of fetus and pup liver cells was not inhibited. Total serum IgG was not affected by spaceflight. None of the examined immune parameters that were altered in rat dams after spaceflight was found to be altered in their offspring.

Effectiveness of cholecystokinin-stimulated cholescintigraphy in the diagnosis and treatment of acalculous gallbladder disease.

We retrospectively reviewed the medical records of 107 patients in two community hospitals who had undergone cholecystokinin-stimulated cholescintigraphy with ejection fraction to determine whether this test is reliable in identifying patients whose symptoms will improve following cholecystectomy. Patients with cholelithiasis or incomplete medical records and patients who could not be interviewed were excluded from the study. Forty-two of 58 study patients (72%) had an abnormal ejection fraction (defined as 35% or less); 27 of 42 patients (64%) underwent cholecystectomy. Twenty-six of 27 (96%) reported lessening of or resolution of symptoms following cholecystectomy. Sixty-seven per cent of the surgical specimens from the 27 patients demonstrated chronic cholecystitis. Fifteen of 42 patients (36%) with abnormal ejection fractions did not undergo cholecystectomy; 12 of 15 (80%) also reported lessening or resolution of symptoms. Of the 16 of 58 patients with a normal ejection fraction, 2 underwent cholecystectomy and reported resolution of symptoms. Five of 14 (36%) with normal ejection fractions who did not undergo cholecystectomy reported improvement. In this series, most patients with an abnormal ejection fraction had lessening of symptoms regardless of whether they underwent cholecystectomy.

Nosocomial pneumonia in ventilated trauma patients during stress ulcer prophylaxis with sucralfate, antacid, and ranitidine.

OBJECTIVE: To compare the incidence of nosocomial pneumonia in critically injured patients randomized to one of three stress ulcer prophylaxis regimens. DESIGN: Prospective, randomized clinical trial. METHODS: Mechanically ventilated patients admitted to the trauma intensive care unit of a Level I trauma center received sucralfate, antacid, or ranitidine. MEASUREMENTS AND MAIN RESULTS: Two hundred forty-two patients were randomized: sucralfate, n = 80; antacid, n = 82; and ranitidine, n = 80. There was no statistically significant difference in pneumonia rates among the treatment groups (p = 0.875). Pneumonia occurred more frequently in patients with gram-negative retrograde colonization from stomach to trachea (p = 0.02), but this accounted for only 13% of all pneumonias in the study population. The death rate in patients with pneumonia was not statistically different among the three groups. Although 20% developed overt gastrointestinal bleeding, no episode was clinically significant. Mean gastric pH was > 4 in 95% of the study population, including 88% of patients receiving sucralfate. The death rate in the antacid group was significantly higher (p = 0.046) but not because of increased gastrointestinal bleeding or pneumonia. CONCLUSIONS: Our results show no difference in the incidence of nosocomial pneumonia in mechanically ventilated trauma patients during the first 4 days of stress ulcer prophylaxis with sucralfate, antacid, or ranitidine. There is a trend toward decreased pneumonia in the sucralfate group after study day 4. Even after controlling for injury severity, the mortality rate in the antacid group was significantly higher; the reasons for this are unknown.

Human papillomavirus prevalence in pregnancy.

Conventional wisdom has long held that human papillomavirus (HPV) prevalence is increased in pregnancy. We examined cervical swabs of 375 women for HPV DNA using polymerase chain reaction (PCR) and ViraPap with an expanded probe range. Of this population, 115 were pregnant (42 in the first trimester, 46 in the second, and 27 in the third) and 100 were postpartum. The control population consisted of 160 women who were otherwise similar to the pregnant population but were not pregnant or postpartum. Crude associations were examined between HPV prevalence at defined high, low, and overall levels and the pregnancy status. Multivariate analysis indicated no statistically significant association between the prevalence at any level of infection and pregnancy status. As expected, associations were found between measures of HPV prevalence and both Papanicolaou smear results and warts seen on examination. No association was found for race, smoking behavior, or number of sexual partners and HPV prevalence. The estimated risk of an HPV infection decreased as the age of the women increased. We conclude that a significant relationship between pregnancy and HPV prevalence has yet to be established.