Levels and distribution of polybrominated diphenyl ethers in water, surface sediments, and bivalves from the San Francisco Estuary

Polybrominated diphenyl ethers (PBDEs) were found in water, surface sediments, and bivalve samples that were collected from the San Francisco Estuary in 2002. sigmaPBDE concentrations in water samples ranged from 3 to 513 pg/ L, with the highest concentrations found in the Lower South Bay (range 103-513 pg/L) region, which receives approximately 26% of the Estuary's wastewater treatment plant effluents. The sigmaPBDEs in sediments ranged from below detection limits to 212 ng/g dry wt, with the highest concentration found at a South Bay station (212 ng/g dry wt), which was up to 3 orders of magnitude higher than other stations. The sigmaPBDE concentrations ranged from 9 to 64 ng/g dry wt in oysters (Crassostrea gigas), from 13 to 47 ng/g dry wt in mussels (Mytilus californianus), and from 85 to 106 ng/g dry wt in clams (Corbicula fluminea). Only three PBDE congeners were detected in bivalves, BDE-47, BDE-99, and BOE-100; these are the most bioaccumulative congeners from the commercial Penta-BDE mixture.     

Determination of the unique orientation of two bodies connected by a ball-and-socket joint from four measured displacements

In previous analyses, it has been shown that a maximum of eight relative orientations exist for two bodies connected by a ball-and-socket joint when the distances between three pairs of points are measured. In this paper it is shown how a unique orientation can be determined if the distances between four pairs of points are known. At the outset, the introduction of redundant information is an attractive method for obtaining the unique orientation result. However, this paper demonstrates that high accuracy in the measurement of the linear displacements must be maintained to obtain an accurate result for the orientation. © 1998 John Wiley & Sons, Inc.     

Comparison of acid and amyloglucosidase hydrolysis for estimation of non‐structural polysaccharides in feed samples

Enzymatic methods (amyloglucosidase) and methods based on acid solutions (0.1, 0.2 and 0.3 M H₂SO₄ for 1, 2 and 3 h at 100 °C) for the hydrolysis of non‐structural carbohydrates from different feed samples were compared. The monomeric units resulting from the enzymatic and acid hydrolysis were determined by the glucose oxidase and reducing sugar methods. There was a significant effect of acid concentration and of time of hydrolysis on the glucose and reducing sugar values in the hydrolysate. Glucose values were similar for both the amyloglucosidase method and the most intense conditions of hydrolysis (0.3 M for 3 h) for some samples. Under these conditions, however, the reducing sugar values were higher. No acid hydrolysis method was found to estimate correctly the total non‐structural carbohydrates, but α‐linked glucose polymers in biological samples may be determined by sample hydrolysis with a 0.3 M H₂SO₄ solution for 3 h at 100 °C since the glucose in the hydrolysate is determined by the glucose oxidase method and the sucrose content of the sample is negligible. © 1999 Society of Chemical Industry     

Successful transcatheter embolic control of massive hematobilia secondary to liver biopsy

A 43-year-old female alcoholic had massive hematobilia secondary to arterial trauma of a liver biopsy. The arterial bleeding site was successfully embolized through an angiographic catheter with Gelfoam sponge. No liver ischemia occurred and the patient has remained well.     

Estimation of demographic toxicity through the double bootstrap

Toxicity to organisms is usually expressed in terms of an observable effect on individuals from which a summary endpoint (such as the NOEC or ECx) is derived for risk assessment and environmental quality standards. However, toxicity evaluated in terms of a demographic endpoint may be more relevant to such regulatory applications. In this paper the effect of toxicity on population growth rate r is explored in tandem with a 'double bootstrap' to incorporate uncertainty. Exemplifying the approach with a set of individualized life table response data obtained for Daphnia magna exposed to zinc sulphate solution, the influence of increasing concentrations is assessed. A demographic-based metric for r, the ErCx (effect on r concentration percentage), is defined to permit alternative population level estimation of a 'safe effect' concentration.     

Comparison of two dust collection methods for reservoir indoor allergens and endotoxin on carpets and mattresses

Variable methods of dust collection may lead to uncertainty in the measurement of biomarkers. The purpose of this study was to examine the effect of two different dust collection devices on dust weight, Der p 1, Fel d 1, and endotoxin levels. We compared: (1) a nylon mesh sock inserted between the furniture attachment and the vacuum hose (the reference method) and (2) the ALK device. Duplicate dust samples were collected for 2 min from 2 m(2) of 37 living room floors and from each longitudinal half of 37 mattresses. Measurement of Der p 1 and Fel d 1 were by double monoclonal antibody enzyme-linked immunosorbent assay (ELISA) and endotoxin by a Limulus Amobocyte Lysate assay. Geometric mean ratios (95% confidence intervals) were calculated to show the differences between sampling devices for each measurement. Compared with the ALK device, the reference method collected significantly more dust from floors (sevenfold) and mattresses (threefold) and more total Der p 1, Fel d 1, and endotoxin in both sites. Floor, but not mattress, Der p 1 concentrations were also significantly higher (threefold) using our reference method. We recommend that, in order to minimize sampling device bias, allergen and endotoxin are expressed as a concentration, and that the bed is considered the major source of allergen exposure. Practical Implications Dust sampling equipment can influence the dust yield. In order to have confidence in comparisons of allergen and endotoxin reservoir levels between centers, standardization in the use of sampling equipment is important.     

Ketoconazole and other imidazole derivatives are potent inhibitors of peroxisomal phytanic acid alpha-oxidation

Twelve young adults were treated with either melatonin, 3 mg or 6 mg, or placebo, at two different times before an early evening nap (18.00-20.00 h) according to a balanced double-blind Latin square design. Polysomnographic monitoring revealed that both dosages of melatonin significantly shortened sleep latency and increased total sleep time in comparison to placebo, irrespective of the time of administration. Subjects also tended to assess their sleep as 'deeper' after melatonin treatment. Based on previous data and the present results, it was concluded that exogenous melatonin exerts hypnotic effects only when circulating levels of endogenous melatonin are low.