Travel and changes in routine do not increase the risk of sudden infant death syndrome

We investigated the relationship between travel and changes in routine and the sudden infant death syndrome (SIDS) among 485 SIDS cases compared with 1800 randomly selected control infants. There was no increased risk of SIDS with travel. Special events, such as christenings, were not associated with an increased risk of SIDS. However, visits to and by friends or relatives were associated with a significantly reduced risk of SIDS after controlling for potential confounders (odds ratios = 0.70; 95% confidence interval = 0.52, 0.96). These findings may indicate less social support in SIDS cases.     

Abnormalities in surfactant in sudden infant death syndrome as a postmortem marker and possible test of risk

To determine whether physical abnormalities in lung surfactant, particularly inversion of the hysteresis between surface tension and surface area, are an effective postmortem marker for sudden infant death syndrome (SIDS).

Methodology:

Bronchoalveolar lavage (BAL) was employed to obtain lung rinsings from 55 infants under 24 months of age at autopsy, comprising 34 index cases and 21 controls. Folch reagent was used to extract the lipoid content which was then applied at two surface concentrations, fixed and BAL-determined (BALD), to the pool of a Langmuir trough in which surface tension (γ) was measured continuously by the Wilhelmy method as surface area ( A ) was cycled.

Results:

The γ: A loops from SIDS samples were inverted relative to controls (i.e. they were hysteresis reversed, this inversion being quantified by an empirical surface tension:area reversal (STAR) score). There was a wide scatter of STAR scores, but a critical value was found which offered a significant ( P = 0.017) separation of SIDS cases from controls for a fixed surface concentration and a highly significant separation ( P = 1.0 × 10^-4) for BALD surface concentrations. Differences in the yields of phospholipid and proteolipid, or their correlation to STAR scores, did not reach statistical significance.

Conclusions:

Inversion of the γ: A loops (i.e. hysteresis inversion) would appear to offer a better postmortem marker of SIDS than any reported previously, the procedure having potential for development as a prospective test indicating the risk of this disease.     

The Association Between Nonbarrier Contraceptive Use and Condom Use Among Sexually Active Latina Adolescents

PurposeThis study aimed to determine the association between use of highly effective methods of nonbarrier contraception and condom use in a sample of Latina adolescents and whether the change to a more effective method of nonbarrier contraception is associated with a change in condom use.MethodsAs part of a larger study, 442 sexually active Latina adolescents aged 14–18 years were surveyed immediately before an appointment with a medical care provider at a school-based health center and 3 months later. Ordinal logistic and linear regression were used in the analysis of cross-sectional and longitudinal data to assess the relationship between patterns of nonbarrier contraception and condom use.ResultsThe use of all types of nonbarrier methods of contraception was significantly associated with decreased condom use. Change over time from a less effective to a more effective nonbarrier method of contraception was also associated with a decrease in condom use. Greater number of sexual encounters was associated with lower the frequency of condom use.ConclusionsThe use of highly effective methods of nonbarrier contraception was associated with reduced frequency of condom use. This highlights the need to promote condom use concurrently with nonbarrier methods of contraception to improve protection against both pregnancy and STIs.     

Reduction of body doses in rotational panoramic radiography by means of reduced beam width in combination with rare earth intensifying screens

Abstract – The absorbed doses in the body of a Rando-Alderson phantom were measured in rotational panoramic radiography (OP-5) with LiF-700 crystals using conventional intensifying screens and standard collimator, as well as rare earth intensifying screens and a collimator slit of reduced width. The reduction of the absorbed doses obtained by using the latter combination was calculated. The reduction range in different regions was 0–50%. The greatest reduction was obtained in the cranial part of the phantom. In the caudal part little or no reduction was observed, probably because leakage radiation contributes substantially to the absorbed doses in this area. The average dose equivalent was calculated for organs in which measurements were made in several locations. The reduction was about 50% for these organs except for the gonads (8%). Compared to the estimated average annual dose equivalent originating from the natural background radiation sources, the dose equivalent resulting from this X-ray examination was very small except in the thyroid gland. In this organ the dose equivalent from one exposure corresponded to 36 days of natural background radiation, but it could be reduced to 18 days by using rare earth intensifying screens in combination with reduced beam width.     

Prevention of Infusion Thrombophlebitis

Thrombophlebitis is a frequent and discomforting complication following infusions into peripheral veins. In controlled clinical and animal experiments, it has also been shown that following factors reduce the risk of development of infusion thrombophlebitis: a short infusion time, neutralization of the acid glucose solutions, addition of heparine to sugar solutions, use of short and thin needles instead of plastic cannulae or 30 cmteflon catheters, use of 5% glucose instead of more concentrated solutions and use of glucose in preference to fructose. The importance of in-line membrane filters is not convincing, and the addition of hydrocortisone and the effects of changing administration sets seem without clinical importance. In conclusion, it is possible in clinical praxis to follow principles, which minimize the risk of the unpleasant and long-lasting complication - infusion thrombophlebitis.     

Low binding capacity of murine tetramers mutated at residue 227 does not preclude the ability to efficiently activate CD8+ T lymphocytes

MHC tetramers are used to directly enumerate and visualize the antigen-specific T lymphocyte population of interest by flow cytometry, regardless of the T lymphocyte's functional capacity. Assay sensitivity can be hindered by non-specific binding activity, which is due to the inherent interactions of CD8 and MHC. Point mutations within the alpha3 loop of the HLA MHC class I heavy chain have been shown to reduce or abrogate MHC/CD8 interactions and also alleviate non-specific binding. This report compares the effects of two well-described mutations on the binding capacity and functional capacity of MHC tetramers in the H-2 MHC murine system. Tetramers folded with MHC mutated at either residue 227 or 245 of the class I heavy chain were compared to wild-type tetramer in binding studies using various antigen-specific, TCR-positive lymphocytes and cell lines. These experiments showed that the binding of wild-type and residue 245-mutated tetramer were comparable on CTL cultures, OT-1 splenocytes, and hybridomas. Both wild-type and 245-mutated tetramers' binding capacity was observed to be equally dependent on CD8 expression. Residue 227-mutated tetramer consistently bound antigen-specific CTL less efficiently, but in the absence of CD8 all three tetramers had similar binding capacity. In functional studies, 227-mutated tetramer had the greatest capacity to stimulate cytokine production in the absence of exogenous antigen addition. These experiments demonstrate that reduction of a tetramer's high avidity interaction with CD8 will not necessarily decrease the ability to stimulate the effector functions of activated T cells.     

Towards single screening tests for brucellosis

This paper describes an indirect enzyme-linked immunosorbent assay (I-ELISA) and a fluorescence polarisation assay (FPA), each capable of detecting antibody in several species of hosts to smooth and rough members of the genus Brucella. The I-ELISA uses a mixture of smooth lipopolysaccharide (SLPS) and rough lipopolysaccharide (RLPS) as the antigen, and a recombinant protein A/G conjugated with horseradish peroxidase as the detection reagent. When using individually determined cutoff values, the SLPS/RLPS combined-antigen I-ELISA detected antibody in slightly more animals exposed to SLPS or to RLPS than did I-ELISA procedures using each individual antigen separately. Similarly, the assay using combined antigens detected antibody in slightly fewer animals not exposed to Brucella sp. When a universal cutoff of 10% positivity was used (relative to strongly positive control sera of each species), the overall performance index (percentage sensitivity plus percentage specificity) value decreased by 1.0 (from 199.4 to 198.4). In the FPA, it was not possible to use a universal cutoff without significant loss of performance. The overall sensitivity value for the FPA using the combined FPA antigen was 1.0% lower than using the O-polysaccharide (OPS) from SLPS and 9.1% higher than using the core antigen (CORE) from RLPS. When the combined antigen was used, the FPA specificity was slightly higher (1.2%) than from only the OPS, and considerably higher (12.6%) than the CORE. Overall, both the I-ELISA and the FPA with combined antigens were suitable as screening tests for all species of Brucella in the animal species tested.     

The Composite Quality Score (CQS) as a trial appraisal tool: inter-rater reliability and rating time

Clinical Oral Investigations - To establish the CQS inter-rater reliability and rating time and to compare both against that of the Jadad scale and Cochrane’s Risk of Bias Tool (ROBT). Four...