A brominated flame retardant, 2,2',4,4',5-pentabromodiphenyl ether: uptake, retention, and induction of neurobehavioral alterations in mice during a critical phase of neonatal brain development.

Polybrominated diphenyl ethers (PBDEs) are used in large quantities as flame retardant additives. In a recent study, we have seen that neonatal exposure to some brominated flame retardants can cause permanent aberrations in spontaneous motor behavior that seem to worsen with age. In view of an increasing amount of PBDEs in mother's milk and in the environment, the present study was undertaken to investigate whether there is a critical and limited phase, during neonatal life, for induction of persistent neurotoxic effects of 2,2',4,4',5-pentaBDE (PBDE 99). Neonatal NMRI male mice were exposed on day 3, 10, or 19 to 8 mg 2,2',4,4',5-pentaBDE/kg body weight. Uptake and retention of 2,2',4,4',5-penta[(14)C]BDE were studied in the mouse brain after exposure to 1.5 M becquerel (Bq) 2,2',4,4',5-penta[(14)C]BDE /kg body weight (bw) on postnatal day 3, 10, or 19. Spontaneous motor behavior was observed in 4-month-old mice. Mice exposed to 2,2',4,4',5-pentaBDE on day 3 or 10 showed significantly impaired spontaneous motor behavior, whereas no effect was seen in mice exposed on day 19. Neonatal mice exposed to 2,2',4,4',5-penta[(14)C]BDE 99 on postnatal day 3, 10, or 19 were sacrificed 24 h or 7 days posttreatment. The amount of radioactivity, given as per mille ( per thousand) of total amount administered, was between 3.7 and 5.1 per thousand in the three different age categories at 24 h after administration. Seven days after the administration, 2,2',4,4',5-penta[(14)C]BDE or its metabolites could still be detected in the brain. The amount of radioactivity in the brain was not higher in mice exposed on day 3 or 10 when compared to exposure on day 19. Thus, the behavioral disturbances observed in adult mice following neonatal exposure to 2,2',4,4',5-pentaBDE are induced during a defined critical period of neonatal brain development.     

The lipid composition of highly differentiated human hepatomas,with special reference to fatty acids.

The lipid compositions of homogenates and microsomal fractions derived from surgical samples of highly differentiated human hepatoma, morphologically normal regions outside the tumours and from normal livers were analysed. A few enzyme activities were also assayed. Hepatoma microsomes demonstrated considerably lowered levels of cytochromes P-450 and b5. Hepatoma homogenates exhibited increased levels of cholesterol, normal amounts of dolichyl-P and slightly lowered levels of total phospholipid. The levels of dolichol, dolichol ester and ubiquinone in hepatoma homogenates were prominently decreased. In tumour microsomes the levels of cholesterol and dolichyl phosphate were increased considerably while the levels of phospholipid and dolichol were lowered. The phospholipid composition of tumour homogenates was roughly similar to that of control tissue. In tumour microsomes the relative amounts of phosphatidylserine and phosphatidylinositol were about 30% decreased, whereas the major phospholipids showed minor increases in amount. The rate and pattern of incorporation of [3H]glycerol into individual phospholipids in liver slices from control and hepatoma tissue did not differ to any larger extent. The fatty acid composition of tumour homogenates exhibited minor differences in comparison to the control with the greatest changes in the sphingomyelin fraction. In hepatoma microsomes the fatty acid compositions of the major phospholipids were altered moderately, with evident decreases in the relative amounts of the long-chain polyunsaturated fatty acids. In hepatoma homogenates the fatty acid composition of dolichol esters differed only slightly from the control pattern. These results indicate that the major disturbance in the lipid metabolism of highly differentiated hepatomas is localized to the mevalonate pathway, thus affecting mainly the levels of cholesterol, dolichol and ubiquinone.     

中药骆驼蓬生物碱提取及抗包虫化学成份研究

骆驼蓬具有镇咳，抗风湿等作用，近年报道又有抗肿瘤，治疗包虫病的作用，为进一步阐明药物作用机理。提高药物的疗效，降低毒副作用，我们对该植物的种子用化学方法进行了生物碱提取，分离，并经ＭＰ测定，薄层层析，ＵＶ，ＩＲ，ＭＳ，ＮＭＲ光谱分析，分离，鉴别出了其中含量较高的两个单体：分别确定为骆驼蓬碱和去氢骆驼蓬三，并据测得的一些化学和光谱数据，初步推测出了此类抗包虫有效成份的化学结构。     

Cardiovascular follow-up of patients with prostatic cancer treated with single-drug polyestradiol phosphate

Thirty-eight patients with cancer of the prostate were treated with strict parenteral estrogen in the form of monthly polyestradiol phosphate injections--160 mg, 240 mg, and 320 mg--in this nonrandomized study. In contrast to studies with oral estrogens, there have been no cardiovascular complications at a mean follow-up of 12.9 +/- 0.7 months (SEM). Twenty-nine of the 38 patients (76%) have responded to therapy.     

Visual disturbances after industrial triethylamine exposure

Summary Among 19 workers in a polyurethane foam production plant, visual disturbances (foggy vision, blue haze, and sometimes halo phenomena) were reported on a total of 47 occasions by five workers over 11 weeks. The symptoms were associated with triethylamine exposure. Time-weighted average levels of 12 to 13 mg/m³ were recorded at work operations associated with symptoms, and 4 to 5 mg/m³ at other tasks. Twice as high peak levels were recorded. A detailed medical examination of the five affected workers in a free interval did not reveal any signs of permanent eye disease.     

Airborne arsenic and urinary excretion of metabolites of inorganic arsenic among smelter workers

Summary The relationship between airborne concentrations of arsenic and the urinary excretion of inorganic arsenic metabolites (inorganic arsenic + methylarsonic acid + dimethylarsinic acid) have been studied among smelter workers exposed to arsenic trioxide. The urinary concentrations of arsenic metabolites were found to increase steadily during the first day of the working week (after 2–3 d off from work), whereafter they reached a steady state. The concentration in the late evening after a day of exposure was very similar to that in the early morning after. Both were well correlated to the total daily excretion. In the second part of the study, comprising 18 subjects, the first-void morning urine of each participant was collected for 2 to 3 d during the steady-state phase. Total concentration of arsenic in the breathing zones was measured by personal air samplers. Airborne arsenic (8-h values) varied between 1 and 194 g As/m³, and urinary arsenic between 16 and 328 g As/g creatinine. With the urinary arsenic concentrations (mean values of 2–3 d for each subject) plotted against the corresponding airborne arsenic concentrations, the best fit was obtained by a power curve with the equation y = 17 x x^0.56. However, four of the participants were found to excrete far more (105–260%) arsenic in the urine than possibly could have been inhaled, most likely due to oral intake of arsenic via contaminated hands, cigarettes or snuff. If these four were excluded, the best fit was obtained by a straight regression line with the slope 2.0 and the intercept 29 g As/g creatinine (coefficient of correlation 0.92; P < 0.001).     

Evaluation of the adenosine triphosphate test in the diagnosis of urinary tract infection

Determination by bioluminescence of the bacterial adenosine triphosphate (ATP) level in urine was evaluated as a method for detection of bacteriuria in 1126 women with symptoms of UTI and 530 attending for follow-up. Conventional urine culture was used as reference method. The criterion for bacteriuria was growth of 10⁵ cfu/ml, giving a prevalence of 0.60. ATP levels of <10 nmol/l and >50 nmol/l indicated abacteriuria and bacteriuria, respectively, whereas intermediate concentrations required culture if the nitrite test was negative. With this diagnostic strategy the sensitivity and specificity was 0.96 and 0.90 at the first visit and 0.90 and 0.98 at follow-up. With some methodological improvement the ATP test could be useful in medium-sized and small laboratories.     

Receptor function studies in specimens from the proximal human urethra obtained by transurethral resection

Summary During transurethral resection (TUR) for prostatic hyperplasia, specimens were taken from the proximal urethra. Muscle strips thus obtained were mounted in an organ bath and muscle contraction was induced by adding increasing concentrations of noradrenaline (NA), methoxamine (₁-agonist) and clonidine (₂-agonist). NA and methoxamine induced a dose-dependent muscle contraction, but clonidine had no effect. The influence of prazosin (₁-antagonist) and yohimbine (₂-antagonist) on the NA-induced muscle contraction was also evaluated. Both antagonists had an inhibitory effect,which was much more potent with prazosin. The specimens taken during TUR were found to be suitable for in vitro receptor function studies. The -adrenergic receptor function in the proximal human urethra was found to be mainly of the -type.     

‘Like holding the axe on who should live or not’: adolescents’ and adults’ perceptions of valuing children’s health states using a standardised valuation protocol for the EQ-5D-Y-3L

Quality of Life Research - There is an increasing interest for using qualitative methods to investigate peoples’ cognitive process when asked to value health states. A standardised valuation...