1-Benzopyran-4-one antioxidants as aldose reductase inhibitors.

Starting from the inhibitory activity of the flavonoid Quercetin, a series of 4H-1-benzopyran-4-one derivatives was synthesized and tested for inhibition of aldose reductase, an enzyme involved in the appearance of diabetic complications. Some of the compounds obtained display inhibitory activity similar to that of Sorbinil but are more selective than Quercetin and Sorbinil with respect to the closely related enzyme, aldehyde reductase, and also possess antioxidant activity. Remarkably, these compounds possess higher pKa values than carboxylic acids, a characteristic which could make the pharmacokinetics of these compounds very interesting. Molecular modeling investigations on the structures of inhibitors bound at the active site of aldose reductase were performed in order to suggest how these new inhibitors might bind to the enzyme and also to interpret structure-activity relationships.     

Spatial and temporal dynamics of hepatic stellate cell activation during oxidant-stress-induced fibrogenesis.

In vitro and in vivo studies indicate that oxidant stress is implicated in liver fibrogenesis. However, it is still unknown whether, in vivo, oxidant stress directly affects the hepatic cells responsible for fibrogenesis, ie, the hepatic stellate cells (HSCs). This study was aimed at answering this question by assessing the temporal and spatial relationships between oxidant stress and activation of HSCs in an in vivo model of oxidant-stress-associated fibrogenesis. To this purpose, rats were treated with carbon tetrachloride (CCl4) and livers subjected to in situ perfusion with nitroblue tetrazolium, which, in the presence of superoxide ions, is reduced to an insoluble blue-colored formazan derivative and is readily detectable in the tissue by light microscopy. Moreover, various combinations of in situ hybridization and immunocytochemical analyses were performed. An acute dose of CCl4 caused a transient production of superoxide radicals at 24 hours into pericentral necrotic areas, whereas HSC appearance and expression of collagen mRNA were detectable only at 48 and 72 hours. After chronic CCl4 intoxication, higher levels of oxygen radical production in necrotic areas were detectable along with dramatic and sustained activation of HSCs. However, maximal HSC activation was still delayed as compared with superoxide production. Expression of heme oxygenase, a gene responsive to a variety of oxidant stress mediators, was strongly enhanced by chronic CCl4 administration but remained unchanged in HSCs, both in situ and after isolation of pure HSC fractions from control and CCl4-treated animals. In conclusion, during postnecrotic fibrogenesis, oxidant stress anticipates HSC activation. HSCs do not directly face an oxidant stress while engaged in active fibrogenesis.     

Mutation spectra analysis suggests that N-(2-chloroethyl)-N′-cyclohexyl-N-nitrosourea-induced lesions are subject to transcription-coupled repair in Escherichia coli

To determine the influence of some bacterial DNA report pathways on the mutagenic and the lethal effects of N-(2-chloroethyl)-N′-cyclohexyl-N-nitrosourea (CCNU), pZ189 plasmids treated in vitro with 2 mM CCNU were transfected into Escherichia coli strains with different repair capacities (uvr⁺ada⁺ogt⁺, uvr⁻ada⁺ogt⁺, and uvr⁻ada⁻ogt⁻). Despite the differences in repair capacities, no statistically significant difference in survival and mutability was observed among the tested strains. One hundred and sixty-six CCNU-induced supF mutants were isolated and sequenced. All mutants were characterized by single base-pair substitutions, most of which (more than 96%) were GC→AT transitions (the mutated G being almost exclusively preceded 5′ by a purine). Mutation distribution was not random. Position 160 (5′-GGT-3′, nontranscribed (NT) strand) was a uvr⁺ada⁺ogt⁺-specific hot-spot. Position 123 (5′-GGG-3′, NT strand) was a common hot-spot but significantly more mutable in repair-proficient strains than in repair-deficient strains. Conversely, position 168 (5′-GGA-3′, transcribed (T) strand) was significantly more mutable in repair-deficient strains than in repair-proficient strains. By applying a computer program for comparison of mutational spectra, we found that the uvr⁺ mutational spectrum was significantly different from those obtained in uvr⁻ strains, whereas in the uvr⁻ background, no difference was observed between mutation spectra in ada⁺ogt⁺ versus ada⁻ogt⁻ strains. Our results are consistent with the hypothesis that O⁶-alkylguanine is responsible for most mutations observed in all strains. The results also indicate that excision repair modulates the distribution of GC→AT transitions. The fact that mutations at G lesions on the T strand were significantly less frequent in uvr⁺ than in uvr⁻ strains suggests that CCNU-induced premutational lesions are susceptible to strand-preferential repair in E. coli. Mol. Carcinog. 19:39–45, 1997. © 1997 Wiley-Liss, Inc.     

Anti-enterobacteria antibodies in psoriatic arthritis.

The occurrence of certain antibacterial antibodies was studied in the sera of 22 healthy donors (HD) and 66 patients with different diseases. The cases investigated included 22 rheumatoid arthritis (RA), 22 non-arthritic-psoriasis (NAP), and 22 psoriatic arthritis (PA) patients. A complement fixation test was used with Yersinia enterocolitica 0:3 type (YEC), Yersinia pseudotuberculosis (YPT), Campylobacter jejuni (CJ), and Campylobacter fetus (CF) antigens; the detection of anti-Chlamydia trachomatis (CT) antibodies was carried out using an immunoperoxidase colorimetric slide test that allowed the detection of isotypes of specific antibodies. It was found that the synthesis of anti-CF, CJ, YEC, and YPT antibodies in NAP patients does not differ significantly from that of the HD group; on the contrary, the antibody levels were statistically higher in PA than in the other disease groups or in the healthy controls, although only anti-CF antibodies seemed to significantly differentiate (p = 0.000003) the PA group from the others. Anti-CT IgA antibody titers were found to be significantly higher in the PA as well as in the RA groups when compared with the controls, while the antibody levels in NAP patients showed no clear-cut difference with respect to those of either the arthritic patients or the healthy controls. By showing that anti-enterobacterial antibodies are increased in PA but not in NAP patients, our data furnish additional support to the thesis of a pathogenic role of bacterial infections in psoriatic arthritis.     

Bronchopulmonary involvement in ulcerative colitis

We report two cases of pulmonary involvement in ulcerative colitis. The first patient, a 37-year-old woman, had bilateral basal bronchiectasis full of mucopurulent secretion, with a marked improvement of pulmonary function and roentgenographic appearance after a conservative approach. The second patient had severe pulmonary fibrosis of autoimmune nature and died owing to a pulmonary infection. In the second patient, a sulfasalazine reaction as an etiologic factor was excluded, while in the first this possibility seemed unlikely. Therefore, we take these two cases as examples of the extraintestinal manifestations of ulcerative colitis.     

Pulmonary hypertension complicating bone marrow transplantation for idiopathic myelofibrosis

Idiopathic myelofibrosis is a rare hematologic disorder that is occasionally associated with pulmonary hypertension and has been cured with bone marrow transplantation (BMT). Most cases occur in older adults, but children with similar clinical and pathologic findings have been described. The authors describe a critically ill male infant with idiopathic myelofibrosis and subtle findings suggestive of pulmonary hypertension who was treated with BMT after failing to respond to chemotherapy. After BMT, the patient's clinical course improved in all respects, but he ultimately died of progressive pulmonary hypertension.     

Recruiting future nurses: a collaborative project

Society as a whole must be involved in making certain there are enough professionals in the future to provide care for the health needs of both rural and urban communities. As a result of this need, Area Health Education Centers (AHECs) across North Carolina have expanded their health care career awareness efforts. One AHEC focused on the concept of awareness of nursing careers by the community, for the community. This project is ongoing and, through collaborative efforts, keeps nursing career awareness in the forefront.