Completing the sequence of the Sulfolobus solfataricus P2 genome.

The Sulfolobus solfataricus P2 genome collaborators are poised to sequence the entire 3-Mbp genome of this crenarchaeote archaeon. About 80% of the genome has been sequenced to date, with the rest of the sequence being assembled fast. In this publication we introduce the genomic sequencing and automated analysis strategy and present intial data derived from the sequence analysis. After an overview of the general sequence features, metabolic pathway studies are explained, using sugar metabolism as an example. The paper closes with an overview of repetitive elements in S. solfataricus.

Single cell analysis of IL-4 and IFN-gamma production by T cells from HIV-infected individuals: decreased IFN-gamma in the presence of preserved IL-4 production.

The specific in vitro disturbance of capacities ascribed to Th1 cells in HIV-infected individuals suggests a switch from Th1 to Th2 lymphokine secretion. Indeed, when T cell clones are generated from HIV-infected individuals compared with controls, an increased percentage of Th0 clones is present upon HIV infection. We studied cytokine production in the supernatant of in vitro activated PBMC from a large group of HIV-infected patients at various stages of infection. IL-2, IFN-gamma, IL-4, IL-5, and IL-10 production all were decreased significantly, which does not support a switch to Th2 lymphokine secretion and is possibly due to the generalized impaired response of T cells from HIV-infected individuals to activation signals in vitro. Therefore, we investigated the capacity of single cells to produce a certain cytokine. Intracellular staining of IL-4- and IFN-gamma-producing cells revealed that T cells from HIV-infected individuals contained decreased numbers of IFN-gamma-producing cells, in the presence of normal percentages of cells with the capacity to produce IL-4. This resulted in significantly decreased IFN-gamma/IL-4 ratios in both CD4+ and CD8+ T cells. Thus, in agreement with previous findings in T cell clones, we conclude, from cytokine production upon stimulation of T cells in vitro, that there is a change in the cytokine balance to the Th2 side in HIV infection due to decreased Th1 and preserved Th2 cytokine production.

Cineaortography in the assessment of aortic regurgitation: a comparison of different catheter types.

The accuracy in diagnosing aortic regurgitation was studied in 170 consecutive cineaortograms. In 85 patients (group A) cineaortograms were undertaken with Sones or Gensini catheters, which produce a jet of contrast material directed towards the aortic valve. The other 85 patients (group B) underwent cineaortography with pigtail catheters, which may cause more equal distribution of contrast material in the aortic root. In group A, 31 of 71 patients (44%) without clinically known aortic valve disease showed angiographic grade I-III/IV aortic regurgitation. In group B only 8 of 61 patients (13%) without clinical evidence of aortic valve disease had grade I-II/IV aortic regurgitation on cineaortography. This difference is statistically significant (P less than 0.001). We conclude that catheters which produce a jet of contrast medium directed straight at the aortic valve can cause artificial trivial to moderate aortic regurgitation. Angiographic evaluation of aortic regurgitation should be performed with a catheter such as a pigtail or closed-end multiple sidehole catheter in which the contrast medium is not directed straight at the aortic valve.

Early and 8 year results of aortic valve replacement: a clinical study of 232 patients.

The study concerns early and late results of aortic valve replacement (AVR) in 232 patients with aortic valve disease, using the Björk-Shiley tilting-disc prosthesis. Of the 232, 27 patients had some evidence of mitral valve disease with valvulotomy having been undertaken in 7 previously, and in 12 at the time of the aortic valve replacement. Patients who underwent simultaneous mitral valve replacement and/or aorta coronary artery bypass grafting are not included in this analysis. To establish predictions of early death and late survival the patients were divided into two groups (A and B), taking 6 pre-operative risk factors into consideration: systolic pressure gradient greater than or equal to 100 mmHg; NYHA class IV; depressed left ventricular function (heart failure); previous valvulotomy of the aortic valve; advanced age (greater than or equal to 70 years) and surgery during the acute stage of bacterial endocarditis. In group A, consisting of 132 patients with no preoperative risk factors, early mortality was 1.5% (2/132). In group B, with 1 or more risk factors, early mortality amounted to 15% (15/100), (P less than 0.01). Subdividing group B into patients with one of the first three risk factors and patients with two or three of these risk factors, mortality was 12% (9/73) and 27% (6/22), respectively. Actuarially determined survival curves showed an 8-year survival rate of 84.2% for patients in group A and 59.6% for patients belonging to group B. Corrected for early mortality, however, the difference in late mortality is not significant. Analysis showed that early mortality was related to myocardial preservation: results for coronary perfusion and cardioplegic arrest were similar, but results were far less good when hypothermic ischaemic arrest was applied. Late results were less favourable in patients who had prior mitral valve disease not requiring mitral valve replacement at the time of AVR, or in those who developed mitral valve disease. The results allow the authors to conclude that AVR is a relatively safe procedure with a low operative mortality and few postoperative complications in patients with no 'risk factors'.