Biodesulfurization of dibenzothiophene in Escherichia coli is enhanced by expression of a Vibrio harveyi oxidoreductase gene.

One possible alternative to current fuel hydrodesulfurization methods is the use of microorganisms to remove sulfur compounds. Biodesulfurization requires much milder processing conditions, gives higher specificity, and does not require molecular hydrogen. In the present work we have produced two compatible plasmids: pDSR3, which allows Escherichia coli to convert dibenzothiophene (DBT) to hydroxybiphenyl (HBP), and pDSR2, which produces a Vibrio harveyi flavin oxidoreductase. We show that the flavin oxidoreductase enhances the rate of DBT removal when co-expressed in vivo with the desulfurization enzymes. The plasmids pDSR2 and pDSR3 were co-expressed in growing cultures. The expression of oxidoreductase caused an increase in the rate of DBT removal but a decrease in the rate of HBP production. The maximum rate of DBT removal was 8 mg/h. g dry cell weight. Experiments were also conducted using resting cells with the addition of various carbon sources. It was found that the addition of glucose or glycerol to cultures with oxidoreductase expression produced the highest DBT removal rate (51 mg/h. g dry cell weight). The culture with acetate and no oxidoreductase expression had the highest level of HBP production. For all carbon sources, the DBT removal rate was faster and the HBP generation rate slower with the expression of the oxidoreductase. Analysis of desulfurization intermediates indicates that the last enzyme in the pathway may be limiting.

Present and potential therapy for allergic rhinitis: a review.

Allergic rhinitis can affect up to one-fifth of the population and the economic impact is increasing. H(1) receptor antagonists were the first major pharmacologic treatment, but the associated sedation limited their use. The 2 initial second generation less sedating antihistamines, astemizole and terfenadine, were found to prolong the cardiac QT(c) interval, especially when administered with other medications metabolised by the same cytochrome (CYP) P450 isoenzyme, CYP3A4. Other second generation antihistamines, fexofenadine, loratadine and cetirizine, do not cause clinically significant cardiac QT(c) interval prolongation. Two newer agents, ebastine and mizolastine, are also effective in the treatment of allergic rhinitis. Ebastine, however, prolongs the cardiac QT(c) interval in laboratory animals and humans, the clinical significance of which is unknown. Desloratadine and norastemizole, metabolites of loratadine and astemizole, respectively, are 2 other second generation antihistamines found to be effective treatments for seasonal allergic rhinitis. Unlike their parent compounds, they do not prolong the cardiac QT(c) interval. All clinically available intranasal corticosteroids are effective in the treatment of allergic rhinitis, but studies to evaluate possible long term systemic adverse effects are limited. Mometasone furoate and fluticasone propionate have lower oral bioavailability compared with other corticosteroids that are given intranasally. This may be important, since it is likely that some of the intranasal corticosteroid is ingested. Two 1-year growth studies in children indicated that intranasal beclomethasone dipropionate given twice daily reduces growth velocity, whereas intranasal mometasone furoate given once daily in the morning does not. Other studies are needed. Most but not all studies have shown that leukotriene antagonists are effective in the treatment of allergic rhinitis. H(1) receptor antagonists are not very effective in reducing nasal congestion, but leukotriene antagonists do attenuate this symptom. Furthermore, one study demonstrates an additive benefit in treating allergic rhinitis with the combination of a H(1) receptor and leukotriene antagonist. Clinical trials have demonstrated that anti-immunoglobulin (Ig) E is effective in the treatment of seasonal allergic rhinitis when free IgE is reduced to <25 microg/L. The reduction of total IgE is dose dependent and subcutaneous and intravenous administration are both effective. Immunotherapy is also an effective treatment for allergic rhinitis. CpG oligonucleotides is a novel adjuvant for allergen immunotherapy. This adjuvant used in a murine model shifts the immune response away from the allergic or TH2 phenotype. Studies in humans have not been performed.

A man with inflamed ears.

A 23-year-old man presented with fever, dyspnea, nonproductive cough, left eye redness, reduced vision, and bilateral ear pain and tenderness. The symptoms had begun two days earlier, eight days after he was discharged from the hospital with a presumptive diagnosis of Still's disease. He was first seen a month before the current admission for complaints of fever (as high as 39.4 degrees C), nonproductive cough, and asymmetric arthritis. The workup at that time included arthrocentesis of the right knee. Analysis of the joint fluid showed 7,500 white blood cells/mm3 and no crystals. A gram stain and culture of the fluid were negative. HIV and hepatitis tests, bone marrow biopsy and culture, transesophageal echocardiography, abdominal computed tomography, radionuclide bone scanning, and rheumatologic tests failed to identify the problem. The development of an evanescent macular pink rash on day 15 suggested the possibility of Still's disease. Treatment with prednisone (40 mg po qd) was initiated, and the patient was discharged on day 19.

Acute onset of dermatitis, hepatitis, and eosinophilia.

A 48-year-old man presented to the emergency department complaining of fever, chills, myalgias, and diffuse abdominal discomfort of four days' duration. A nonpruritic rash had developed on his left palm, arms, legs, and buttocks on the fourth day. He had not had respiratory symptoms, nausea, vomiting, or diarrhea.