Genome Sequence and Comparative Genomics Analysis of a Vibrio cholerae O1 Strain Isolated from a Cholera Patient in Malaysia

The genome sequence analysis of a clinical Vibrio cholerae VC35 strain from an outbreak case in Malaysia indicates multiple genes involved in host adaptation and a novel Na⁺-driven multidrug efflux pump-coding gene in the genome of Vibrio cholerae with the highest similarity to VMA_001754 of Vibrio mimicus VMA223.     

A retrospective study of 932 second trimester terminations using gemeprost (16,16 dimethyl-trans delta 2 PGE1 methyl ester).

A retrospective study of 932 second trimester terminations between 12-27 weeks gestation was carried out to determine the efficacy of gemeprost for second trimester termination. A single course of 5 x 1 mg gemeprost pessaries was administered every three hours. If abortion had not occurred after the first course of pessaries, a further course of 5 x 1 mg pessaries was administered. Intravenous oxytocin was administered after 36 hours if abortion had not occurred. Eighty per cent and ninety five per cent of patients aborted within 24 and 48 hours respectively. Of the remaining 5 per cent of women, 3 per cent aborted with escalating doses of oxytocin. In the remaining 18 (2 per cent) women, the pregnancies were electively terminated with an alternative method. The median induction-abortion interval was 18.0 hours and 15.0 hours in nulliparous and parous women respectively (P less than 0.0001). The number of pessaries required to induce abortion was not influenced by parity. Significantly more parous women bled more than 500 ml. The incidence of pelvic sepsis (0.1 per cent) and cervical tear (0.1 per cent) was low. Twenty six per cent of women had diarrhoea and 23 per cent vomited following administration of prostaglandin. This study confirmed the efficacy of gemeprost for second trimester termination of pregnancy. This method of termination is safe, non-invasive, simple and has a low complication rate.     

Bacterial siderophores : structure and NMR assignment of pyoverdins Pa,siderophores ofPseudomonas aeruginosa ATCC 15692

Summary In iron-deficient conditions,Pseudomonas aeruginosa ATCC 15692 synthesizes two major siderophores, pyoverdins Pa and pyoverdin Pa B. Two other compounds, pyoverdin Pa A (occurring from hydrolysis of pyoverdin Pa during the culture) and pyoverdin Pa C (occurring artifactually during the purification procedure) were also isolated. All these compounds possess the same partly cyclic peptide chain wherel-Orn(OH · HCO) isN -formyl,N -hydroxy-l-ornithine. The chain is bound to a chromophore derived from 2,3-diamino-6,7-dihydroxyquinoline and having the (S) configuration. The four pyoverdins differ only in the acyl substituent bound to the nitrogen atom bound to carbon C3 of the chromophore. This is succinamide (pyoverdin Pa), succinic acid (pyoverdin Pa A), methyl succinate (pyoverdin Pa C) and 2-oxoglutaric acid (pyoverdin Pa B). The complete¹H- and¹³CNMR assignments, using two-dimensional total correlation NMR spectroscopy (TOCSY) and rotating-frame Overhauser enhancement spectroscopy (ROESY) procedures, as well as¹H-¹³C correlations, are reported. The complete sequence of the peptide using CH-NH correlations was achieved by NMR and confirmed the partly cyclic structure earlier reported using fast-atom-bombardment mass spectrometry (FAB-MS) on the siderophores and their dansylated fragments [Briskot G, Taraz K, Budzikiewicz H (1989)Liebigs Ann Chem: 375–384]. The use of these NMR procedures appears to be a tool of choice and a complementary approach to FAB-MS in the structure determination of some complex pyoverdins.Abbreviations Ser serine - Arg arginine - Thr ethreonine - Lys lysine - OHOrn N -hydroxyornithine - Chr chromophore     

Conformational studies of a benzodiazepine-like peptide in SDS micelles by circular dichroism, 1H NMR and molecular dynamics simulation

The conformation of a benzodiazepine-like decapeptide corresponding tothe YLGYLEQLLR fragment of a casein has been examined in a sodium dodecylsulfate micellar medium using circular dichroism, two-dimensional¹H NMR spectroscopy and restrained molecular dynamicssimulation. The decapeptide adopts an amphipathic 3₁₀-helicoidstructure in which theE⁶···R¹⁰ ionic bridgestabilizes the C-terminus.     

Experimental study on aggregation of model dipeptide molecules. V. Stereoselective association of leucine dipeptides

Infrared spectroscopy and ¹H nmr have been used to elucidate the association modes of leucine dipeptides in carbon tetrachloride solution. Two stereoselective types of aggregates have been evidenced. Homochiral molecules are associated in oligomeric aggregates and accommodate a β-parallel-like structure which was characterized by x-ray diffraction. Heterochiral molecules are paired in centrosymmetrical dimers; the latter aggregation mode restricted to the dimer stage predominates in racemic solutions. A theoretical model proposed to account for this aggregation process is consistent with the experimental nmr data. Both homo- and heterochiral association constants are estimated from vapor pressure and nmr experiments.     

Étude expérimentale de l'auto-association des molécules modèles dipeptidiques. II. Association stéréosélective des molécules énantiomères

Modes of aggregation fo alanine-, norvaline- and valine-contaiing dpepetides with the general formula R₁? C₁O₁? N₂H₂? CHR₂? C₂O₂? N₃H₃? R₃ have been studied in CCl₄ solution by using infrared and nuclear magnetic resonance spectroscopies. Solutions of the pure L isomer and of the racemic mixture do not give identical data. At a given concentration, the racemic mixtrue is more aggregated than the pure enantiomer, and the difference, negligible in the case of alanine derivative, increases wiht the bulkiness of the side cahin R₂. The results show that a selective interaction takes place between enantiomeric molecules, resulting ina dimer associating tow inverse configurated C₅ conformers. The stabilizaion of this dimer proceeds from two symmetrical and intermolecular H₃ … O₁ hydrogen bondings.     

Effector cell activity in antibody mediated cell dependent immune lysis. II. Evidence for different populations of effector cells for different targets.

Using the adhering property of certain types of cells to glass or plastic in human peripheral blood lymphocyte preparations, two populations of effector cells can be identified in the ABCIL system, each with a selective killing directed toward a different antibody coated target. The adherent cells which are radioresistant functionally, with the morphology of macrophages, exhibit strong cytotoxicity against the antibody-coated erythroid target while lacking any killing effect toward the antibodycoated target lymphocytes. The nonadherent cells which are radiosensitive and with the morphology of small lymphocytes, selectively kill the antibody-coated lymphocyte target without possessing any cytotoxicity against the antibody-coated target erythrocytes.     

Effects of the bark beetle nematode, Contortylenchus reversus, on gallery construction,fecundity, and egg viability of the Douglas Fir beetle, Dendroctonus pseudotsugae (Coleoptera: Scolytidae)

Healthy and Contortylenchus reversus infected Douglas Fir beetles were colonized in logs in the laboratory. At 7, 14, and 23 days after introduction of the beetles into the logs, the bark was removed from some of the logs and the length and shape of the primary gallery, the number of eggs laid, and the egg viability were determined for each pair of parent beetles. Parasitism caused a 25, 28, and 27% reduction in the length of the primary egg gallery built by the infected female at 7, 14, and 23 days, respectively, after the start of colonization. In addition, the number of eggs laid by the infected females by 7, 14, and 23 days after the start of colonization were 50, 33, and 45%, respectively, lower than that of healthy female beetles. Despite the differences in gallery length between control and infected females, linear regression analysis showed that the rates of gallery construction were not significantly different. However, infected female beetles showed significantly lower rates of egg-laying than did healthy female beetles. Nematode parasitism did not affect gallery shape and egg viability of female Douglas Fir beetles. Mating of healthy female beetles with infected males affected neither the gallery length nor the fecundity of the uninfected females.