Bed-Sharing in the First 8 Weeks of Life: An Australian Study.

Background As the evidence continues to emerge about the relationship between sudden unexpected death in infancy (SUDI) and the way an infant sleeps, providing consistent and evidence-informed recommendations on how best to sleep infants is an ongoing challenge. A recent case series study in the state of Victoria, Australia, identified 45.8% of sleep-related infant deaths occurred whilst bed-sharing. This study prompted the need for further exploration of infant sleeping practices, including bed-sharing, in this population. Methods A cross-sectional survey of 2745 mothers attending the Maternal and Child Health (MCH) Service across Victoria, Australia was conducted. Data included the prevalence and circumstances of bed-sharing, family demographics, and SUDI risk and protective factors. Associations between bed-sharing and SUDI risk and protective factors were examined using univariate and multivariate analyses. Results Bed-sharing prevalence was found to be 44.7%, with 21.5% reporting that this was intended. Multivariate analyses showed bed-sharing was less likely amongst those with an annual household income above $AUS104, 000 (OR 0.72; 95% CI 0.54-0.96) and more likely amongst mothers who breastfed (OR 1.71; 95% CI 1.23-2.37). Conclusions Bed-sharing prevalence in this population compares closely with the Victorian case series study and a previous cross-sectional study in the state of Queensland, Australia, in 2002. Noted gaps in how families are implementing current recommendations about reducing the risk of SUDI were identified for sleep position, sleep location and the sleep environment. Further consideration needs to be given to addressing these gaps and applying these findings of current bed-sharing practices to the development of infant safe sleeping policy and programs.

Effect of sodium hypochlorite on the growth of rats and guinea pigs.

Four experiments were conducted with a total of 100 rats and 20 guinea pigs to determine the effects of adding sodium hypochlorite to the drinking water and milk. In three experiments, the liquids were provided ad libitum, but in one it was given by gavage so that the dosage could be expressed in relation to body weight. Available chlorine concentrations ranging between 0 and 2,000 mg/L were tested over periods of 9 days to 6 weeks. Stimulation of growth rate was observed in all experiments with body weight increases of 5.4% to 13.7%. Statistical significance at P less than 0.05 was reached in two experiments. Optimal growth rate was observed with available chlorine concentrations of 20 mg/L in liquids given free choice and at 8 mg/kg of body weight when given by gavage. Toxic effects of the sodium hypochlorite were not observed at any of the concentrations tested below 2,000 mg/L.

Volumetric method for determing traces of organic chlorine in lipids.

The official AOAC method for determining chlorine in cake flour lipids has been modified to determine chlorine in lipids of animal carcasses cooled with chlorinated water. The sensitivity of the method has been improved 1000-fold to attain a detection limit of 2 ppm Cl in lipids. Recovery of the fine silver chloride precipitate was improved through centrifugation rather than filtration. The official method also did not take into consideration that when the silver chloride precipitate is exposed to light, it is converted to free chlorine and silver. Recovery of organic chlorine ranged from 84.6% at 4.1 ppm to 100.1% at 100 ppm. A number of samples of commercially chlorinated beef, pork, and chicken and laboratory-chlorinated chicken were analyzed by this method. In all cases where the level of chlorination was sufficient to result in a chlorine level in lipids in excess of 2 ppm, the chlorine content of the carcass lipids was measurable.

Implications of inorganic/organic interconversion on fluxes of arsenic in marine food webs.

An organic form of arsenic is commonly encountered in marine organisms; in greysole and shrimp, it accounted for all arsenic found in muscle tissue. It has been isolated from flounder tissue by two independent procedures; it was hydrophilic, cationic, and was not decomposed to inorganic arsenic by hot nitric and sulfuric acids. NMR spectroscopy indicated all nonexchangeable protons to be equivalent; they behaved more like N-methyl protons than As-methyl protons. High-resolution mass spectroscopy from a heated probe yielded a spectrum corresponding to tetramethylarsonium (AsMe4+); the authentic ion, however, had TLC and ion-exchange behavior different from that of the natural product. Infrared spectrometry likewise produced conflicting or uninterpretable data. Decomposition of the compound for analytical purposes was accomplished by dry ashing under oxidizing conditions. Sea urchins, like trout, converted arsenic to an organic form, but to a more limited degree. Arsenic found naturally in sea urchins and in a species of macroalga was also organic. In individual containers, sea urchins were fed on the alga for 7 weeks. During this time they consumed 0.203 +/- 0.075 mg total As and excreted only 0.036 +/- 0.015 mg as feces. Measurement of inorganic As in the seawater did not account for the discrepancy, but measurements of total As did (0.202 +/- 0.095 mg). Sea urchins, like humans, appear to be able to rapidly excrete these organic forms of arsenic.

Toxic effects of chlorinated cake flour in rats.

Four experiments were conducted using weanling Wistar rats to determine whether chlorinated cake flour or its constituents were toxic. Levels of 0.2 and 1.0% chlorine added to unbleached cake flour significantly (p less than 0.01) reduced growth rate by 20.7 and 85.2% and increased liver weight relative to body weight by 16.7 and 25.3%, respectively. Lipids extracted from flour chlorinated at the same levels had similar effects. Rat chow diets containing 0.2 and 0.6% chlorine in the form of chlorinated wheat gluten reduced growth rate and increased liver weight as a percentage of body weight. A rat chow diet containing 0.2% chlorine as chlorinated flour lipids increased absolute liver weight by 40%, kidney by 20%, and heart by 10% compared to pair-fed controls.

Quantitative relationship of fecal asbestos to asbestos exposure.

A method is descirbed for isolating chrysotile fibers from feces and counting them with an electron microscope. The detection limit was 150,000 fibers per gram feces; average recovery was 85.5%. When the method was used to check the asbestos in feces of people subjected to industrial exposure vs. controls, the means were significantly different (p less than 0.02). Duplicate fecal samples were found to check within an average of +/- 31.1% of their means.