Key aspects of the Novartis compound collection enhancement project for the compilation of a comprehensive chemogenomics drug discovery screening collection

The NIBR (Novartis Institutes for BioMedical Research) compound collection enrichment and enhancement project integrates corporate internal combinatorial compound synthesis and external compound acquisition activities in order to build up a comprehensive screening collection for a modern drug discovery organization. The main purpose of the screening collection is to supply the Novartis drug discovery pipeline with hit-to-lead compounds for today's and the future's portfolio of drug discovery programs, and to provide tool compounds for the chemogenomics investigation of novel biological pathways and circuits. As such, it integrates designed focused and diversity-based compound sets from the synthetic and natural paradigms able to cope with druggable and currently deemed undruggable targets and molecular interaction modes. Herein, we will summarize together with new trends published in the literature, scientific challenges faced and key approaches taken at NIBR to match the chemical and biological spaces.

Determination of ochratoxin A in green coffee by immunoaffinity column cleanup and liquid chomatography: collaborative study

A collaborative study was conducted to evaluate a method using immunoaffinity column cleanup with liquid chromatography (LC) for the determination of ochratoxin A (OTA) in green coffee at levels that could be included in possible future regulations of the European Union. The test portion was extracted with methanol-3% aqueous sodium hydrogen carbonate solution (50 + 50, v/v). The extract was filtered, and the filtrate was diluted with phosphate-buffered saline and applied to an immunoaffinity column containing antibodies specific for OTA. After washing, the toxin was eluted from the column with methanol and quantified by LC with fluorescence detection. Pairs of 4 homogeneous noncontaminated and naturally contaminated materials (mean levels of < 0.12, 2.44, 5.15, and 13.46 ng/g) and blank samples (< 0.12 ng/g) for spiking were sent to 20 participant laboratories from 8 countries. The materials were analyzed according to the method description and all difficulties encountered in the analysis were reported. Statistical analysis was carried out according to the Harmonized Protocol of the International Union of Pure and Applied Chemistry. The relative standard deviation for repeatability (RSDr) ranged from 7.42 to 20.94%, and the relative standard deviation for reproducibility (RSDR) ranged from 16.34 to 29.17%. The method showed acceptable within-laboratory and between-laboratories precision for green coffee materials, as evidenced by HorRat values of < or = 0.85, at the studied range, for spiked and naturally contaminated materials. The mean recovery was 92.8% for green coffee material spiked with OTA at a level of 4.82 ng/g.

Dysregulation of IL-2/IL-2R system alters proliferation of early activated CD4+ T cell subset in patients with end-stage renal failure

BACKGROUND/AIM

Although CD4+ T cells are preactivated in patients with end-stage renal failure (ESRF), these patients present an impairment of T cell immune response, which is partly responsible for the higher incidence of infection in this population. The aim of the present study was to analyze the mechanisms underlying the altered function of activated CD4+ T cells in patients with ESRF.

METHODS

Thirty patients undergoing chronic hemodialysis (HD) and 20 patients with ESRF were compared with 15 sex- and age-matched controls. CD4+ T cell early activation (CD69, CD25), interleukin-2 (IL-2)/IL-2 receptor (IL-2R) system, and proliferation capacity of CD69+/CD4+ T cells were assessed ex vivo after blood draw sampling, in culture conditions and after phytohemagglutinin (PHA) stimulation.

RESULTS

Although the CD4+ T cell count was lower in chronic HD patients than in predialysis patients and controls (p = 0.007), CD4+ T cells showed a pre-activation state as demonstrated by higher percentage of CD69+/CD4+ T cells and CD25+/CD4+ T cells in chronic HD patients compared with the other groups ex vivo. Furthermore, CD69+/CD4+ T cells from chronic HD patients spontaneously released more IL-2 (22 +/- 6 pg/ml) than those from pre-dialysis patients (12 +/- 4 pg/ml, p = 0.005) and controls (5 +/- 3 pg/ml, p = 0.001). However, after PHA stimulation, CD69+/CD4+ T cells from chronic HD patients expressed lower cell surface CD25 density, and were unable to show further activation. Indeed, these cells produced less IL-2 and released more soluble IL-2R, and correlatively with IL-2 production, they showed lower proliferation capacity compared with predialysis patients (p = 0.001) and controls (p < 0.001). They also displayed decreased responsiveness to exogenous human recombinant IL-2. The restoration of the PHA stimulation index of CD69+/CD4+ T cells from chronic HD patients in the presence of normal human serum as well as the decreased stimulation index of CD69+/CD4+ T cells from control subjects incubated with HD serum, strongly suggest that uremic toxins and mediators induced by HD affect the IL-2/IL-2R pathway.

CONCLUSION

These findings demonstrate the presence, in chronic HD patients, and to lesser extent, in predialysis patients, of abnormally high proportion of spontaneously preactivated CD4+ T cells whose proliferation and further activation are blunted due to dysregulation of the IL-2/IL-2R system.

[Selective COX-2 inhibitors and cardiovascular risk]

Selective cyclooxygenase-2 (COX-2) inhibitors were initially developed to reduce the gastrointestinal toxicity of conventional NSAIDs. However, it became rapidly evident that selective COX-2 inhibitors may increase the risk of cardiovascular events. Today, the mechanisms for the potentially adverse cardiovascular effects of coxibs remain unknown, and it is increasingly clear that our understanding of the role of COX-2 in cardiovascular function is incomplete. Based on some available indirect evidence, and unless more clear-cut data become available, the longterm use of high doses of selective COX-2 inhibitors, in elderly patients or patients with a high cardiovascular risk should be limited whenever possible.

[Fever of unknown origin with granulomatous hepatitis, uveitis and acute renal failure]

A 46-year-old man was referred to our hospital because of fever of unknown origin (FUO). Two months before admission, he noted fever, weight loss, and asthenia. Physical examination revealed only mechanical pains of the right shoulder. In the past, patient's father had a tuberculosis. At the age of 29 years, Brucella granulomatous hepatitis and B hepatitis were diagnosed. The past three years, he developed two episodes of uveitis which resolved with local treatment. The hepatic biopsy revealed only a non specific granulomatous hepatitis. Few days after admission, the patient developed acute renal failure without proteinuria or hematuria. The renal biopsy confirmed the presence of noncaseating granulomas. In the context of the patient, we diagnosed a sarcoidosis. All the symptoms resolved with the initiation of prednisone treatment. The FUO differential diagnosis, and the different aspects of renal sarcoidosis are discussed.

Vacuum-assisted Conservative Treatment for the Management and Salvage of Exposed Prosthetic Hemodialysis Access

Recurrent puncture of dialysis grafts can cause erosion and ulcer formation in the skin over the prosthetic material. Contamination of the wound can lead to infection of the graft, and the necessity to remove it. We describe four cases where agressive treatment with debridement, intravenous antibiotics and negative pressure therapy allowed prosthesis salvage without discontinuation of hemodialysis.

Bulbusrekonstruktion bei ausgedehnten Verletzungen des Hinterabschnittes

Severe injuries of the posterior eye segment mostly occur during perforation or rupture of the globe. The first treatment includes primary surgical repair of the ocular wound and prophylactic scleral buckling in case of involvement of the posterior segment. Thereafter, a vitrectomy should be performed to remove vitreous hemorrhage and intraocular foreign bodies and to achieve a stable attachment of the retina. Therefore, temporary perfluorocarbon and permanent silicone oil tamponade are used. A predictor of poor visual outcome is the presence of retinal and choroidal injury. In our patients, the most important prognostic factor was the initial visual acuity after the injury. Vitrectomy can significantly reduce the incidence of enucleation. Currently, better visual outcome is achieved by advances in surgical techniques.

A duck hepatitis B virus strain with a knockout mutation in the putative X ORF shows similar infectivity and in vivo growth characteristics to wild-type virus

Hepadnaviruses including human hepatitis B virus (HBV) and duck hepatitis B virus (DHBV) express X proteins, HBx and DHBx, respectively. Both HBx and DHBx are transcriptional activators and modulate cellular signaling in in vitro assays. To test whether the DHBx protein plays a role in virus infection, we compared the in vivo infectivity and growth characteristics of a DHBV3 strain with a stop codon in the X-like ORF (DHBV3-X-K.O.) to those of the wild-type DHBV3 strain. Here we report that the two strains showed no significant difference in (i). their ability to induce infection that resulted in stable viraemia measured by serum surface antigen (DHBsAg) and DHBV DNA, and detection of viral proteins and replicative DNA intermediates in the liver; (ii). the rate of spread of infection in liver and extrahepatic sites after low-dose virus inoculation; and (iii). the ability to produce transient or persistent infection under balanced age/dose conditions designed to detect small differences between the strains. Thus, none of the infection parameters assayed were detectably affected by the X-ORF knockout mutation, raising the question whether DHBx expression plays a physiological role during in vivo infection with wild-type DHBV.

[Retroperitoneal fibrosis, an unrecognized inflammatory disease. Clinical observations and review of the literature]

Retroperitoneal fibrosis (RF) is a rare disease, typically with an insidious clinical course. The peak incidence is seen in patients 40 to 60 years of age and mostly in man. The characteristic finding in this disease is a periaortic fibrous mass that often surrounds the ureters. Although usually regarded as an obstructive uropathy, there has been growing recognition of the condition as a generalized disease. It may have a wide variety of manifestations including mediastinitis, thyroiditis and sclerosing cholangitis. The most common mode of presentation remains abdominal or flank pain with uremia, anemia and a high sedimentation rate. Although ultrasound and renal scintigraphy may contribute to the general evaluation of patients with RF, CT-scanner is the preferred imaging method. The multiplanar imaging capability of magnetic resonance may facilitate assessment of disease extent. The pathogenesis of the disease remains unknown. Steroids and, more recently tamoxifen, appear to be effective in the treatment of the RF. In most instances, RF does not lead to long-term morbidity or affect survival. The three cases of RF reported herein illustrate the varied mode of presentation and the response to the treatment.

[Evolution of interventional cardiology in France during the last decade (1991-2000)]

The annual inquiry by the "Angiography and Interventional Cardiology Group" of the French Society of Cardiology has allowed the evolution of interventional cardiology in France between 1991 and 2000 to be monitored. The results of the 2000 inquiry have been analysed in particular. The number of coronarography centres has increased by 27% in 10 years, growing from 173 in 1991 to stabilise at 220, and the number of centres performing percutaneous coronary angioplasty grew from 128 to 175 (+27%) at the same time. The number of coronarographies increased by 79% (131,636 to 236,111), and angioplasties increased by 197% (30,885 to 91,901). In the year 2000, angiographic procedures represented 39% of coronarographies, against 23% in 1991. Endoprosthesis implantation constitutes the principal revolution of this decade, the number of procedures growing from 393 to 77,388 between 1991 and 2000, some 84.2% of angioplasties, and a total number of endoprostheses of 107,869 (1.39 stents per procedure). The other revascularisation techniques remain anecdotal, representing only 1.9% of procedures. In 2000, at the 135 centres supplying detailed information, direct stenting represented 38.5% of procedures, and the indications for restenosis were 9.9%. The number of interventions performed in the public or private sector is almost identical for each category, only morphological or functional explorations remain the privilege of the public sector in the university setting. The activity of the University Hospitals Centres has noticeably and regularly decreased since 1991, falling from 39.2% to 28.7% of coronarographies and from 41.8% to 31.1% of angioplasties in 2000.