[Hypersensitivity vasculitis causing an acute abdomen]. / Hypersensitivitätsvaskulitis als Ursache eines akuten Abdomens.

The members of a family of four persons suffered acute gastroenteritis after eating a meal consisting of chicken. While three of them recovered rapidly, the 18-year old son developed an acute abdomen which had to be treated surgically and led to a complicated stay at the intensive care unit. Intraoperatively, a mild insignificantly inflamed appendix and an obscure segmental inflammatory process of the small bowel with local peritonitis were seen; this required an appendectomy and a peritoneal lavage. The development of bacterial peritonitis with multiple organ dysfunction required several surgical revisions with an open abdominal toilet treatment. Histological examination of the resected appendix specimen showed a severe primary fibrinoid necrotizing vasculitis with epitheloid-granulomatous reaction. Diseases such as Panenteritis nodosa, Wegener's disease and Churg-Strauss's syndrome were excluded by negative serology. By a process of exclusion, a hypersensitivity vasculitis was diagnosed and treated successfully with a high-dose cortisone regime.

A comparative investigation of DNA adducts, DNA strand breaks and gene mutations induced by benzo[a]pyrene and (+/-)-anti-benzo[a]pyrene-7,8-diol 9,10-oxide in cultured human cells.

Genotoxic effects of benzo[a]pyrene (BP) and its reactive metabolites (+/-)-anti-benzo[a]pyrene-7,8-diol 9,10-oxide ((+/-)-anti-BPDE) were comparatively investigated in vitro with the permanent human fibroblast cell line MRC5CV1. Induced DNA adducts were measured by 32P-postlabeling, DNA strand breakage was determined by the comet assay and the HPRT gene mutation test was used to detect cytotoxicity and mutagenicity. Treatment of MRC5CV1 cells with S9 mix-activated BP or with (+/-)-anti-BPDE resulted in a concentration-dependent increase in DNA adducts and strand breaks. Genotoxic effects of BP and (+/-)-anti-BPDE were detected by 32P-postlabeling and the comet assay with similar sensitivity. However, under the same experimental conditions, a clear induction of gene mutations was only found after (+/-)-anti-BPDE treatment. The relationship between the induction of primary DNA alterations like DNA strand breaks and DNA adducts and the induction of gene mutations is discussed.

Detection of DNA effects in human cells with the comet assay and their relevance for mutagenesis.

The single cell gel test (SCG-test or comet assay) is a rapid and sensitive method for measuring DNA damage and repair in individual cells. A wide variety of mutagens have been shown to cause DNA alterations detectable with the comet assay, but it is not yet clear whether a relationship exists between the DNA effects and the induction of mutations. We are therefore investigating in a cell culture system with human cells (MRC5CV1) the induction of DNA damage by environmental mutagens and the formation of mutations at the HPRT gene. In the present study we investigated benzo[a]pyrene (BP), an environmental mutagenic and carcinogenic polycyclic aromatic hydrocarbon, and its reactive metabolite (+)-anti-benzo[a]pyrene-7,8-diol 9, 10-oxide ((+)-anti-BPDE). S9 mix activated BP and the direct acting mutagen (+)-anti-BPDE caused a concentration-related increase in DNA migration in the comet assay. Postincubation experiments indicated that induced DNA effects are eliminated by DNA repair within 24 h. BP-treatment caused a strong genotoxic effect in the comet assay but had only a marginal effect on the frequency of gene mutations. When cells were treated with BP in the presence of cadmium sulphate, a clear increase in genotoxicity was observed while the effect on mutations was unchanged. Our results indicate that DNA alterations detected with the comet assay do not necessarily relate to mutagenesis. The absence of a close relationship between DNA migration in the comet assay and mutagenesis may be explained by the fact that some effects seen in the comet assay occur as a consequence of an error free DNA repair process.

The importance of the effect of underlying disease on rejection outcomes following orthotopic liver transplantation.

Despite major advances in immunopharmacology, virtually all patients receive the same center-specific immunosuppressive regimen following orthotopic liver transplantation (OLT). The present analysis was performed on the hypothesis that the original disease representing the indication for OLT leads to a different initial immunological situation of the patient. The type of original disease might therefore be a predisposing factor for acute rejection episodes and influence graft and patient survival. From January 1988 to July 1994, 34 patients received OLT at our institution for end-stage primary biliary cirrhosis (group 1) and 66 patients for end-stage alcoholic cirrhosis (group 2). Overall survivals at 1 and 5 years in group 1 versus group 2 were 67% versus 80% and 50% versus 68%, respectively (P<0.04). Retransplantation was performed in 21% of patients from group 1 and in 6% from group 2. The estimated risk for freedom from acute rejection amounts to 38% in group 1 compared with 59% in group 2 (P<0.02). Multivariate regression analysis of potential risk factors identified only the underlying disease as independent predictor. Analysis of cumulative rates of clinically relevant rejection episodes stratified by group revealed 0.29 and 0.05 episodes per patient at one month and 0.80 and 0.06 at six months (P<0.009) respectively. In our clinical experience it was possible to confirm the hypothesis that the underlying disease is the reason for a significantly different incidence of acute rejection episodes and that it subsequently influences graft and patient survival. This approach to an individually adapted immunosuppressive therapy should be taken into consideration and other appropriate parameters investigated.

Divergence of the phytochrome gene family predates angiosperm evolution and suggests that Selaginella and Equisetum arose prior to Psilotum.

Thirty-two partial phytochrome sequences from algae, mosses, ferns, gymnosperms, and angiosperms (11 of them newly released ones from our laboratory) were analyzed by distance and character-state approaches (PHYLIP, TREECON, PAUP). In addition, 12 full-length sequences were analyzed. Despite low bootstrap values at individual internal nodes, the inferred trees (neighbor-joining, Fitch, maximum parsimony) generally showed similar branching orders consistent with other molecular data. Lower plants formed two distinct groups. One basal group consisted of Selaginella, Equisetum, and mosses; the other consisted of a monophyletic cluster of frond-bearing pteridophytes. Psilotum was a member of the latter group and hence perhaps was not, as sometimes suggested, a close relative of the first vascular plants. The results further suggest that phytochrome gene duplication giving rise to a- and b- and later to c-types may have taken place within seedfern genomes. Distance matrices dated the separation of mono- and dicotyledons back to about 260 million years before the present (Myr B.P.) and the separation of Metasequoia and Picea to a fossil record-compatible value of 230 Myr B.P. The Ephedra sequence clustered with the c- or a-type and Metasequoia and Picea sequences clustered with the b-type lineage. The "paleoherb" Nymphaea branched off from the c-type lineage prior to the divergence of mono- and dicotyledons on the a- and b-type branches. Sequences of Piper (another "paleoherb") created problems in that they branched off from different phytochrome lineages at nodes contradicting distance from the inferred trees' origin.

Phytochrome evolution: a phylogenetic tree with the first complete sequence of phytochrome from a cryptogamic plant (Selaginella martensii spring).

We have sequenced cDNA and genomic clones coding for phytochrome of the fern Selaginella. On the amino acid level, this phytochrome shares sequence homologies with phytochromes of higher plants which range between 62 (phytochrome B of Arabidopsis) and 55 (56)% [phytochrome C of Arabidopsis (Avena)]. Introns in the Selaginella gene are short and occupy positions known from phytochrome sequences of higher plants. A rooted phylogenetic tree based on mutation distances puts Selaginella phytochrome closest to the hypothetical ancestor. A similar tree arises if the tree is constructed with partial sequences (about 200 amino acids) around the chromophore attachment site. An extension of this tree by sequences of other cryptogamic plants (Mougeotia, Ceratodon, Psilotum) shows all these sequences including those of the phytochromes B and C of Arabidopsis on a branch, well separated from the branch formed by phytochromes known to accumulate in etiolated plants. The rooted phytochrome phylogenetic tree, however, is difficult to reconcile with the fossil record.