Comparison of BGB-MUG and LSTB-MUG in microbiological surveillance of recreational waters

Recreational water surveillance is an important tool to prevent health hazards for the population. Therefore distinct guide and imperative values for fecal indicators are listed in the EC directive about water quality control. The detection methods, however, give laboratories some room to choose their own method, which has led to difficulties in the comparability of results. In 1989 an ad-hoc working group of the coastal countries of Germany established detection methods, which by now are obligatory for these countries. Fecal and total coliforms (FC and TC) are detected by a triplicate mpn-procedure using brilliant green-bile-lactose broth supplemented with tryptophane and 4-methylumbelliferyl-beta-D-glucuronide (BGB-MUG) as selective medium. Gas-, fluorescence- and indole-positive cultures are considered fecal coliform-positive. In the last years rises in TC but not in FC counts were observed in fresh waters. A study was carried out to evaluate the official method in another bathing season, to determine bacterial species leading to false-positive TC cultures and to compare BGB-MUG with laurylsulphate-tryptophane-MUG (LSTB-MUG). Water samples of different salinities and nutrient input were collected in weekly intervals from April to October. FC and TC concentrations were determined and all TC-positive cultures were differentiated further. The FC counts obtained by enrichment in BGB-MUG or LSTB-MUG were nearly identical, the rate of fluorescence-positive, indole-negative tubes being approximately 0.6%. Differentiation of FC-negative cultures showed a false-negative rate of 2.87% for BGB-MUG and of 8% for LSTB-MUG. During the summer months TC counts in BGB-MUG exceeded FC counts by far at most of the sampling sites. This effect was much less pronounced in LSTB-MUG; the difference between both enrichment media being significant. Differentiation of presumptive TC from BGB-MUG resulted in a high percentage of Aeromonas spp. in fresh waters. LSTB-MUG was clearly more selective for TC than BGB-MUG, but still with an average of 10% of the test tubes being false TC-positive (BGB-MUG 46%). The sensitivity of BGB-MUG was below 60% (LSTB-MUG 89%). LSTB-MUG should be preferred as enrichment medium in mpn-examination of recreational water, if no further differentiation is carried out. The selectivity for TC is better than in BGB-MUG and the only slight inhibitory effects can be tolerated.     

Anaphylactic reactions to bee-sting challenges in allergic children are not modified by endogenous catecholamines

To investigate the role of basal catecholamine levels and the response of the adrenergic system to expected bee stings, plasma catecholamines were measured before and 1 and 2 min after bee-sting challenges. Twenty-one children (aged 4-15 y) with bee-sting allergies were selected for sequential challenges to establish the need for venom immunotherapy. The time interval between the challenges varied from 2 to 6 wk. Epinephrine, norepinephrine, and dopamine plasma levels were measured using a simultaneous single-isotope radioenzymatic assay. On the first challenge, 33% of the children experienced a normal local reaction, 29% a large local reaction, and 38% a systemic reaction. On the second challenge in 18 out of 21 subjects, 67% experienced a normal normal local reaction, 22% a large local reaction, and 11% a systemic reaction. Epinephrine and norepinephrine plasma levels increased significantly on the first and second challenges. Dopamine plasma levels showed a significant increase on the first challenge only. Plasma catecholamine levels after the second challenge revealed a significant positive correlation between epinephrine increases measured 1 and 2 min after the challenge and the concomitant sting reaction. Basal epinephrine, norepinephrine, and dopamine plasma levels did not differ significantly between patients who experienced different types of sting reactions. Based on our data, we conclude that clinical reactions to in-hospital insect-sting challenges are not affected by early increases in plasma catecholamine levels produced by the expected stress situation.     

Fetal risks due to warfarin therapy during pregnancy

Two mothers with heart valve prosthesis were treated with warfarin during pregnancy. In the first case a caesarean section was done one week after replacement of warfarin with heparin. The baby died of cerebral and pulmonary hemorrhage. The second mother had a male infant by caesarean section. The baby showed warfarin-induced embryopathy with nasal hypoplasia and stippled epiphyses (chondrodysplasia punctata). Nasal hypoplasia with or without stippled epiphyses has now been reported in 11 infants born to mothers treated with warfarin during the first trimester, and a causal association is probable. In view of the risks to both mother and fetus in women with prosthetic cardiac valves it is recommended that therapeutic abortion be advised as the first alternative.     

Resting energy expenditures in Asian women measured by indirect calorimetry are lower than expenditures calculated from prediction equations

OBJECTIVE: Measured resting energy expenditure (REE) and REEs calculated using the Harris-Benedict equation, Food and Agriculture Organization/World Health Organization/United Nations University (FAO/WHO/UNU) equations (FAO equations), and the Liu equation were compared in Asian women. DESIGN: REEs were measured using indirect calorimetry in the morning after an overnight fast and compared with REEs calculated using the Harris-Benedict equation, the FAO equations, and the Liu equation. Height, weight, and 3-day diet records were also obtained. SUBJECTS: Thirty-six healthy, free-living Asian women aged 19 to 52 years and living in the United States were recruited from Washington State University, Pullman, and completed the study. STATISTICAL ANALYSES: Paired t tests, stepwise regression, one-way analysis of variance, and Pearson correlation coefficients were used for the statistical analyses. Significance was set at P < or = .05. RESULTS: A significant correlation was found between measured REE and REE derived from the Harris-Benedict equation (R = 0.67, P < .0001), the FAO equations (R = 0.70, P < .0001), and the Liu equation (R = 0.70, P < .0001). However, measured REE was significantly lower than REE calculated using the Harris-Benedict and FAO equations by 8.5% (P < .001) and 5.4% (P < .01), respectively. No significant difference was noted between measured REE and REE derived from the Liu equation. APPLICATIONS: Caution must be taken when predicting REE of Asian women using the Harris-Benedict equation or the FAO equation. Indirect calorimetry or an equation specific to Asians, such as the Liu equation, is recommended when an accurate estimate is necessary.     

Electrical and optical properties of very thin gold films †

The electrical and optical properties of discontinuous and semi-continuous gold films evaporated on to dielectric substrates in a high vacuum have been measured. The electrical properties of the films were characterized by DC conductivity and by the temperature coefficient of resistance: the reflectance and transmittance at near-infrared wavelengths were the optical properties considered. Special attention was given to the films in the vicinity of the percolation threshold.     

An algorithm that minimizes audio fingerprints using the difference of Gaussians

Recently,many audio search sites headed by Google have used audio fmgerprinting technology to search for the same audio and protect the music copyright using one part of the audio data.However,if there...