Specificity of Reductive Dehalogenation of Substituted ortho-Chlorophenols by Desulfitobacterium dehalogenans JW/IU-DC1.

Volume 61, no. 1, abstract, lines 4 and 5: "2,6-dichloro-4-R-phenols, where . . ." should read "2,6-dichloro-4-R-phenols (2,6-DCl-4-RPs, where R is -H, -F, -Cl, -NO(inf2), -CO(inf2)(sup-), or -COOCH(inf3)) . . ." Line 6: ". . . bromophenols (2-BrP, 2,6-DBrP, and 2-Br-4ClP)" should read ". . . the bromophenols 2-BrP, 2,6-DBrP, and 2-Br-4-ClP." [This corrects the article on p. 346 in vol. 61.].

Specificity of reductive dehalogenation of substituted ortho-chlorophenols by Desulfitobacterium dehalogenans JW/IU-DC1.

Resting cells of Desulfitobacterium dehalogenans JW/IU-DC1 growth with pyruvate and 3-chloro-4-hydroxyphenylacetate (3-Cl-4-OHPA) as the electron acceptor and inducer of dehalogenation reductively ortho-dehalogenate pentachlorophenol (PCP); tetrachlorophenols (TeCPs); the trichlorophenols 2,3,4-TCP, 2,3,6-TCP, and 2,4,6-TCP; the dichlorophenols 2,3-DCP, 2,4-DCP, and 2,6-DCP; 2,6-dichloro-4-R-phenols (2,6-DCl-4-RPs, where R is -H, -F, -Cl, -NO2, -CO2, or -COOCH3; 2-chloro-4-R-phenols (2-Cl-4-RPs, where R is -H, -F, -Cl, -Br, -NO2, -CO2-, -CH2CO2, or -COOCH3); and the bromophenols 2-BrP, 2,6-DBrP, and 2-Br-4ClP [corrected]. Monochlorophenols, the dichlorophenols 2,5-DCP, 3,4-DCP, and 3,5-DCP, the trichlorophenols 2,3,5-TCP, 2,4,5-TCP, and 3,4,5-TCP, and the fluorinated analog of 3-Cl-4-OHPA, 3-F-4-OHPA ("2-F-4-CH2CO2- P"), are not dehalogenated. A chlorine substituent in position 3 (meta), 4 (para), or 6 (second ortho) of the phenolic moiety facilitates ortho dehalogenation in position 2. Chlorine in the 5 (second meta) position has a negative effect on the dehalogenation rate or even prevents dechlorination in the 2 position. In general, 2,6-DCl-4-RPs are dechlorinated faster than the corresponding 2-Cl-4-RPs with the same substituent R in the 4 position. The highest dechlorination rate, however, was found for dechlorination of 2,3-DCP, with a maximal observed first-order rate constant of 19.4 h-1 g (dry weight) of biomass-1.(ABSTRACT TRUNCATED AT 250 WORDS)

Does the severity of diabetic retinopathy predict pregnancy outcome?

The authors sought to determine whether the severity of diabetic retinopathy is a predictor of subsequent pregnancy outcome. One hundred and seventy-nine pregnant diabetic women were evaluated in their first trimester of pregnancy. Stereoscopic color photographs of the ocular fundus were taken and graded by the Fundus Photography Reading Center. Thirty-nine women had no retinopathy, while 28 had proliferative retinopathy in the worse eye. The women's history and hospital delivery room charts were reviewed with regard to pregnancy outcome. Thirty-three pregnancies terminated with an adverse outcome. A logistic regression analysis was used to evaluate significant predictors of pregnancy outcome. Of maternal age, duration of diabetes, glycosylated hemoglobin, proteinuria, cigarette smoking status, and severity of diabetic retinopathy, only the last variable significantly predicted an adverse outcome. These data suggest that the severity of retinopathy should be considered when counseling a pregnant diabetic woman.

Expansion of the tetragonally arrayed cell wall protein layer during growth of Bacillus sphaericus.

The outermost layer of the cell wall of Bacillus sphaericus strain P-1 is a tetragonally arrayed structure (T-layer) which is assembled from a single polypeptide. No turnover of T-layer was detected during growth of cultures. In contrast, the turnover of peptidoglycan was between 20 and 25% per generation. The sites of deposition of new T-layer on the cell surface were identified by the indirect fluorescent antibody technique, which labeled old T-layer, and by the reverse technique, which labeled new T-layer. These experiments demonstrated that the major area of T-layer deposition was a band at the site of an incipient cell division. This band subsequently split and covered the new pole of each progeny cell. Little or no T-layer was inserted into existing poles. In addition, multiple bands of new T-layer, which probably accommodate cell elongation, were inserted along the lateral surface of the cell.