The IL-12 cytokine family in cardiovascular diseases.

Cytokines of the Interleukin (IL)-12 family, consisting of IL-12, IL-23, IL-27 and IL-35, are important regulators in (chronic) inflammatory disorders such as rheumatoid arthritis and multiple sclerosis, but also in cardiovascular diseases. Cytokines of the IL-12 family consist of two subunits and are known for their regulatory functions in the immunologic response, more specifically in the regulation and differentiation of T-helper (Th) cells such as Th1 and Th17 cells. Binding of these cytokines to its specific heterodimeric receptor results in the activation of the JAK-STAT signaling. Despite similarities in structure, the members of the IL-12 family have diverse, both pro- and anti-inflammatory, effects and functions. Because of the pro-inflammatory effects of IL-12 cytokine family members on immune responses, the IL-12 cytokines have been implicated in the development and progression of cardiovascular diseases such as atherosclerosis, but also in acute cardiovascular syndromes such as myocardial infarction and stroke. For example, patients suffering from cardiovascular disease display increased blood levels of IL-12, IL-23 and IL-27, while decreased IL-35 levels have been linked to a lower cardiovascular risk. In this review, we aim to highlight the current understandings of the IL-12 cytokine family and its specific family members to cardiovascular diseases, including both clinical and experimental studies. We will also discuss the potential of these cytokines as a biomarker in acute cardiovascular syndromes.

Single-molecule measurements of the persistence length of double-stranded RNA.

Over the past few years, it has become increasingly apparent that double-stranded RNA (dsRNA) plays a far greater role in the life cycle of a cell than previously expected. Numerous proteins, including helicases, polymerases, and nucleases interact specifically with the double helix of dsRNA. To understand the detailed nature of these dsRNA-protein interactions, the (bio)chemical, electrostatic, and mechanical properties of dsRNA need to be fully characterized. We present measurements of the persistence length of dsRNA using two different single-molecule techniques: magnetic tweezers and atomic force microscopy. We deduce a mean persistence length for long dsRNA molecules of 63.8 +/- 0.7 nm from force-extension measurements with the magnetic tweezers. We present atomic force microscopy images of dsRNA and demonstrate a new method for analyzing these, which yields an independent, yet consistent value of 62 +/- 2 nm for the persistence length. The introduction of these single-molecule techniques for dsRNA analysis opens the way for real-time, quantitative analysis of dsRNA-protein interactions.

The prevalence and incidence of hepatitis C virus infections among dialysis patients in the Netherlands: a nationwide prospective study.

A nationwide prospective survey on hepatitis C virus (HCV) infections among dialysis patients in The Netherlands was performed. Patients were recruited from 34 dialysis centers and were tested for antibodies and HCV RNA in 1995 and 1997. Seronegative serum samples were analyzed by reverse-transcriptase polymerase chain reaction in pools. HCV-RNA-positive serum samples were genotyped and were partly sequenced. In the first and second rounds, 67 (2.9%) of 2281 and 76 (3.4%) of 2286 patients were HCV positive, respectively. Of 960 patients with paired serum samples, 35 were HCV positive in both rounds, and 9 HCV-positive cases were newly identified in the second round. The incidence of HCV infection was 0.5 per 100 dialysis years. Phylogenetic analysis revealed clustered sequences that indicated nosocomial transmission. Sixty percent of HCV infections, however, can be attributed to 4 interdependent risk factors (i.e., hemodialysis before 1992, kidney transplantation before 1994, and birth or dialysis in a foreign country). In conclusion, the prevalence of HCV infections in The Netherlands does not decline, and transmission within dialysis units continues. Adequate screening of HCV infections and strict enforcement of universal infection control practices are required.