Surfactant release as an early measure of radiation pneumonitis

The immediate release of surfactant into lung alveoli following irradiation has been studied as a potential indicator for the later development of radiation pneumonitis. Utilizing single dose radiation exposure to the whole thorax in male LAF₁/J mice, steep dose response curves for lavaged alveolar surfactant were identified at 7 and 28 days after exposure. Seven days after irradiation there was no elevation with doses up to and including 12 Gy; above this dose a detectable increase occurred. At 28 days the surfactant recovered by lavage was elevated compared to the levels seen at day 7 for all doses; doses > 12 Gy produced surfactant values significantly greater than those found in mice treated with 12 Gy or less. The radiation pulmonary lethality dose response curve assessed four months later indicated an LD₅₀ value of ～13 Gy. The early biochemical effect and the later radiation pneumonitis lethalities therefore closely coincided. The evidence strongly indicates that alveolar surfactant release uncovered hours to days after radiation exposure may be an early biochemical marker that predicts for subsequent pneumonitis radiation injury.     

Increased division of alpha beta TCR+ and gamma delta TCR+ intestinal intraepithelial lymphocytes after oral administration of cholera toxin.

Cholera toxin (CT) or its subunits were given orally to mice and division of intestinal intraepithelial lymphocytes (IEL) in vivo measured by double immunofluorescence using 5-bromo-2'-deoxyuridine (BRdU) and membrane alpha beta T-cell receptors (TCR) or gamma delta TCR staining in frozen sections. Cholera toxin (10 micrograms) produced a two- to eightfold-increase in the uptake of BRdU in alpha beta TCR+ IEL in the duodenum and a two-to fivefold increase in gamma delta TCR IEL in the ileum. Increased uptake of BRdU was also seen after a dose of 100 micrograms of CT but this dose was also associated with the loss of alpha beta TCR+ IEL and gamma delta TCR+ IEL in the duodenum. CT-A and CT-B subunit produced increased BRdU incorporation by alpha beta TCR in the duodenum and by gamma delta TCR IEL in the ileum. Cholera toxin therefore appears to be mitogenic for IEL probably due to an indirect mechanism.     

FFPRHC Guidance (July 2005): The use of contraception outside the terms of the product licence

This Guidance provides information for clinicians and women considering the use of contraception outside the terms of the product licence. A key to the grades of recommendations, based on levels of evidence, is given at the end of this document. Details of the methods used by the Clinical Effectiveness Unit (CEU) in developing this Guidance and evidence tables summarising the research basis of the recommendations are available on the Faculty website (www.ffprhc.org.uk). Abbreviations (in alphabetical order) used include: CEU, Clinical Effectiveness Unit; COC, combined oral contraception/contraceptive; DMPA, depot medroxyprogesterone acetate; ENG, etonogestrel; IUD, copper-bearing intrauterine contraceptive device; LNG-IUS, levonorgestrel-releasing intrauterine system; NET-EN, norethisterone enantate; PGD, Patient Group Direction; PIL, Patient Information Leaflet; POC, progestogen-only contraception/contraceptive; POEC, progestogen-only emergency contraception; POP, progestogen-only pill; RCT, randomised controlled trial; SPC, Summary of Product Characteristics; UPSI, unprotected sexual intercourse; WHO, World Health Organization; WHOMEC, WHO Medical Eligibility Criteria for Contraceptive Use; WHOSPR, WHO Selected Practice Recommendations for Contraceptive Use.     

Preattentive timing of empty intervals is from marker offset to onset

The internal marker hypothesis explains the superior timing performance for empty intervals over filled intervals by assuming that timing an empty interval starts from the offset of the first marker stimulus and stops at the onset of the second marker stimulus. Other models suggest that timing an empty interval is from first marker onset to second marker onset. We used an electrophysiological measure of preattentive change detection, the mismatch negativity (MMN), to examine processing of empty intervals. Participants watched a silent movie while a stream of auditory stimuli demarcating empty intervals was presented in the background. Most intervals were of the same duration (standards), but shorter intervals (deviants) were presented occasionally also. The pattern of MMN amplitudes obtained across five deviant conditions indicated that preattentive timing of empty intervals occurred from marker offset to onset.     

Peer Reviewed: Mortality of Urban Aboriginal Adults in Canada, 1991–2001

Objective

To compare mortality patterns for urban Aboriginal adults with those of urban non-Aboriginal adults.

Methods

Using the 1991–2001 Canadian census mortality follow-up study, our study tracked mortality to December 31, 2001, among a 15% sample of adults, including 16 300 Aboriginal and 2 062 700 non-Aboriginal persons residing in urban areas on June 4, 1991. The Aboriginal population was defined by ethnic origin (ancestry), Registered Indian status and/or membership in an Indian band or First Nation, since the 1991 census did not collect information on Aboriginal identity.

Results

Compared to urban non-Aboriginal men and women, remaining life expectancy at age 25 years was 4.7 years and 6.5 years shorter for urban Aboriginal men and women, respectively. Mortality rate ratios for urban Aboriginal men and women were particularly elevated for alcohol-related deaths, motor vehicle accidents and infectious diseases, including HIV/AIDS. For most causes of death, urban Aboriginal adults had higher mortality rates compared to other urban residents. Socio-economic status played an important role in explaining these disparities.

Conclusion

Results from this study help fill a data gap on mortality information of urban Aboriginal people of Canada.

Keywords

Aboriginal people, First Nations, Métis, Inuit, North American Indians, age-standardized mortality rates, mortality rate, life expectancy     

Computer-assisted estimates of lesion sizes and shrinkage in denervated areas from receptor autoradiograms using a digitizing tablet

Area measurements taken from receptor autoradiograms were employed to estimate the size of striatal kainate lesions and the amount of shrinkage in deafferented projection areas. There was no significant difference in the size of substantia nigra (SN) on the denervated side as compared to the intact side one week and one month after unilateral striatal lesions. Although there was no change in the size of globus pallidus (GP) on the lesioned side one week after the lesion, there was a 17% shrinkage one month after the lesion. At 3-4 months after the lesion, the amount of shrinkage was 19% in SN and 16% in GP.