Fear conditioning is preserved in very preterm-born young adults despite increased anxiety levels

Very preterm birth is associated with an increased risk for anxiety disorders. Abnormal brain development may result in disordered fear learning processes, which may be exacerbated by environmental risk factors and persist in adulthood. We tested the hypotheses that very preterm-born young adults displayed higher levels of fear conditioning, less differentiation between threat (CS+) and safety (CS-) signals, and stronger resistance to extinction relative to term-born controls. A group of 37 very preterm-born young adults and 31 age- and sex-matched term-born controls performed a differential fear conditioning paradigm on two consecutive days. Acquisition and extinction training were performed on day 1. Recall and reinstatement were tested on day 2. Preterm-born participants showed significantly higher levels of anxiety in the Depression-Anxiety-Stress-Scale-21 questionnaire. The fear conditioning outcome measures, skin conductance response amplitudes and anxiety ratings, were overall higher in the preterm-born group compared to controls. Awareness of CS-US contingencies was mildly reduced in preterms. Acquisition, extinction, recall and reinstatement of differential conditioned fear responses (CS+  > CS-), however, were not significantly different between the groups. There were no significant group by stimulus type interactions. The finding of largely preserved associative fear learning in very preterm-born young adults was unexpected and needs to be confirmed in future studies.

[Hybrid NOS appendectomy (NA): clinical assessment of a new surgical technique]

INTRODUCTION, AIM AND METHOD: Consecutive female patients undergoing hybrid NOS appendectomy (NA - with prospectively collected data) and laparoscopic appendectomy (LA - with retrospectively registered data) were compared by means of a matched-pair analysis according to selected criteria such as patient age, BMI, ASA and previous operations showing a near-perfect congruence with the following aims to: 1) demonstrate the feasibility of NA and to estimate its general costs, and 2) elucidate the outcome of the two techniques using available perioperative parameters from daily clinical practice. In particular, operating time, complications, histopathological findings, postoperative hospital stay and analgesic scores were used for comparison. A gynaecological follow-up investigation was carried out on the day of discharge and after a medium-term time period of 4 weeks in the NA group, and 6 months postoperatively, patients of both groups were interviewed using a standardised questionnaire.

RESULTS

From 05/01/2008 to 02/28/2010, transvaginal NA (n = 30) was compared with the results of the conventional LA (n = 30) in 60 female patients with regard to the operative outcome. Overall, matched-pair analysis of LA with NA, the novel technique resulted in the assessment of basically comparable surgical procedures with regard to perioperative routine parameters and outcome. There were no intraoperative complications in either of the two approaches; conversion was not required in both techniques. In addition, there were no significant differences in operating time (p = 0.099), postoperative complications (p = 0.72) and analgesic scores (p = 0.33/0.46). Postoperative hospital stay was even slightly shorter in the NA group (p = 0.02). The costs of the two methods are almost identical if the same instruments are used. Patient interviews suggested a slightly faster recovery, greater satisfaction with the better cosmetic outcome as well as a reduced pain intensity in favour of transvaginal NA.

CONCLUSION

Provided that a well developed laparoscopic expertise exists, it turned out i) that there are no serious reasons to resist a quick inauguration and establishment of NA for selected cases as well as ii) even to facilitate further clinical distribution of NA. Further systematic data collection appears to be indicated to analyse long-term outcome as parameters of an appropriate quality assurance.

Plasmids for efficient single-copy gene cloning into gdh2 and trpC of Bacillus megaterium DSM319 and QM B1551

We constructed integrative plasmids to place xylA-lacZ indicator gene fusions into two different loci of the Bacillus megaterium chromosome, gdh2 and trpC, in lac mutants of strains DSM 319 and QM B1551, which differ markedly. Single-crossover integration was achieved in all cases while double crossovers occurred only in gdh2 of DSM 319 and QM B1551 and in trpC of QM B1551. Neither of the loci affected regulation of the xylA-lacZ fusions. These results confirm the suitability of the two gene loci for single-copy cloning.

Conditions for transformation of Pasteurella multocida by electroporation

Conditions for electroporation of plasmid DNA into Pasteurella multocida were determined for use in developing a cloning system to study virulence factors of P. multocida. The highest efficiency of transformation (1.25 x 10(7) cfu/micrograms DNA) was obtained when 7.6 x 10(10) cells of P. multocida strain R473 were electroporated at 12.5 kV/cm (10 ms, 5 ng of pVM109). Transformation efficiencies of cells prepared at mid-log-phase were approximately 0.5 log10 lower than early, late, or stationary phases. Neither pBR322 nor pUC-19 were able to transform strain R473 under these conditions, even when DNA concentrations were increased to 1 microgram. When pBR322 was ligated with a Pasteurella plasmid, pLAR-1, the hybrid was able to transform strain R473 at an efficiency between 4.5 x 10(2) and 8 x 10(4) cfu/micrograms DNA. Six strains of P. multocida including serotypes A, B, D, and E were transformed successfully.