Second-Trimester Pregnancy Loss at an Urban Hospital

Objectives: Second-trimester spontaneous pregnancy losses are less common than first-trimester losses, and are often associated with ascending infection and/or acute chorioamnionitis. A Medline search revealed only two large studies published in the recent literature, reporting incidences of chorioamnionitis of 39.3% and 58.2%, respectively. These studies did not address the use of histopathology for the identification of organisms. Since ascending infection is likely to be a significant cause of second-trimester loss in the inner-city population at the University Hospital in Newark, New Jersey, we sought to evaluate the usefulness of stains for microorganisms, which are rarely utilized on these specimens. Methods: Retrospective review of the medical records and pathologic material for cases of spontaneous abortions seen at the University Hospital in Newark between January 1999 and March 2001 was undertaken. Stains for microorganisms were performed on archival placental tissue for cases with histologic acute chorioamnionitis. Results: A total of 67 cases were available for review, of which 38 cases (56.7%) showed histologic acute chorioamnionitis, similar to the rates in one previous study, but significantly higher than those in the other (p = 0.01). Of 25 cases with histological chorioamnionitis for which appropriate fetal material was available, 13 cases (52%) showed polymorphonuclear leukocytes (PMNs) in the fetal lungs, one case (4%) showed PMNs in the fetal stomach, and seven cases (28%) showed PMNs in both the lung and the stomach. Of the 38 cases with chorioamnionitis, Gram stains showed Gram-positive cocci in six cases, two of which were culture positive for group B streptococcus. Warthin–Starry stains showed filamentous organisms consistent with Fusobacterium sp. in the placenta in three cases. Conclusions: Acute chorioamnionitis is associated with second-trimester pregnancy loss at this inner-city hospital, and may be related to the high incidence of risk factors in this population. A small proportion of cases can be further characterized by the inclusion of Gram and Warthin–Starry stains in the evaluation. Selection of cases with histologic acute chorioamnionitis for further study with special stains may provide additional information on the causative organism

Photoproduction of mesons off nuclei

Recent results for the photoproduction of mesons off nuclei are reviewed. These experiments have been performed for two major lines of research related to the properties of the strong interaction. The investigation of nucleon resonances requires light nuclei as targets for the extraction of the isospin composition of the electromagnetic excitations. This is done with quasi-free meson photoproduction off the bound neutron and supplemented with the measurement of coherent photoproduction reactions, serving as spin and/or isospin filters. Furthermore, photoproduction from light and heavy nuclei is a very efficient tool for the study of the interactions of mesons with nuclear matter and the in-medium properties of hadrons. Experiments are currently rapidly developing due to the combination of high quality tagged (and polarized) photon beams with state-of-the-art 4pi detectors and polarized targets

Quasi-free photoproduction of eta-mesons off the deuteron

Precise data for quasi-free photoproduction of $\eta$ mesons off the deuteron have been measured at the Bonn ELSA accelerator with the combined Crystal Barrel/TAPS detector for incident photon energies up to 2.5 GeV. The $\eta$-mesons have been detected in coincidence with recoil protons and neutrons. Possible nuclear effects like Fermi motion and re-scattering can be studied via a comparison of the quasi-free reaction off the bound proton to $\eta$-production off the free proton. No significant effects beyond the folding of the free cross section with the momentum distribution of the bound protons have been found. These Fermi motion effects can be removed by an analysis using the invariant mass of the $\eta$-nucleon pairs reconstructed from the final state four-momenta of the particles. The total cross section for quasi-free $\eta$-photoproduction off the neutron reveals even without correction for Fermi motion a pronounced bump-like structure around 1 GeV of incident photon energy, which is not observed for the proton. This structure is even narrower in the invariant mass spectrum of the $\eta$-neutron pairs. Position and width of the peak in the invariant mass spectrum are $W\approx 1665$ MeV and FWHM $\Gamma\approx 25$ MeV. The data are compared to the results of different models.Comment: accepted for publication in Eur. Phys. J.

Probing aggressive motivation in a cichlid fish

The duration of startles provides an inverse measure of motivation to resume the previous activity. Here, we use a novel method in which one convict cichlid fish (Amatitlania nigrofasciata) of a competing pair was startled independently of the opponent. Fish were given various opponents and the mean startle duration determined. This mean was negatively correlated with the mean use of highly escalated ‘frontal activities’ such as biting and frontal display, but not the less escalated lateral displays or tail beating. Thus the startle duration was a reliable surrogate measure of the most escalated components of aggressive interactions. That is, it provided a motivational probe for aggressiveness of individual fish. Fight motivation is often determined in terms of fight duration or physiological costs for losers, who reveal the costs they are prepared to pay. We discuss various potential advantages of the motivational probe over previous measures, particularly with respect to winners and losers and different times during the interactions