Interleukin 12 a Key Immunoregulatory Cytokine in Infection Applications

Interleukin 12 (termed IL-12p70 and commonly designated IL-12) is an important immunoregulatory cytokine that is produced mainly by antigen-presenting cells. The expression of IL-12 during infection regulates innate responses and determines the type of adaptive immune responses. IL-12 induces interferon-γ (IFN-γ) production and triggers CD4+ T cells to differentiate into type 1 T helper (Th1) cells. Studies have suggested that IL-12 could play a vital role in treating many diseases, such as viral and bacterial infections and cancers. The unique heterodimeric structure, which IL-12 shares with its family members including IL-23, IL-27, and IL-35, has recently brought more attention to understanding the mechanisms that regulate the functions of IL-12. This article describes the structure and biological activities of IL-12 in both the innate and adaptive arms of the immune system, and discusses the applications of IL-12 in treating and preventing infections

The Radiation Issue in Cardiology: the time for action is now

The "radiation issue" is the need to consider possible deterministic effects (e.g., skin injuries) and long-term cancer risks due to ionizing radiation in the risk-benefit assessment of diagnostic or therapeutic testing. Although there are currently no data showing that high-dose medical studies have actually increased the incidence of cancer, the "linear-no threshold" model in radioprotection assumes that no safe dose exists; all doses add up in determining cancer risks; and the risk increases linearly with increasing radiation dose. The possibility of deterministic effects should also be considered when skin or lens doses may be over the threshold. Cardiologists have a special mission to avoid unjustified or non-optimized use of radiation, since they are responsible for 45% of the entire cumulative effective dose of 3.0 mSv (similar to the radiological risk of 150 chest x-rays) per head per year to the US population from all medical sources except radiotherapy. In addition, interventional cardiologists have an exposure per head per year two to three times higher than that of radiologists. The most active and experienced interventional cardiologists in high volume cath labs have an annual exposure equivalent to around 5 mSv per head and a professional lifetime attributable to excess cancer risk on the order of magnitude of 1 in 100. Cardiologists are the contemporary radiologists but sometimes imperfectly aware of the radiological dose of the examination they prescribe or practice, which can range from the equivalent of 1-60 mSv around a reference dose average of 10-15 mSv for a percutaneous coronary intervention, a cardiac radiofrequency ablation, a multi-detector coronary angiography, or a myocardial perfusion imaging scintigraphy. A good cardiologist cannot be afraid of life-saving radiation, but must be afraid of radiation unawareness and negligence

Doenças priônicas: avaliação dos riscos envolvidos na utilização de produtos de origem bovina Prionic disease: evaluation of the risks involved in using products of bovine origin

Os príons são proteínas que se mostram capazes de auto-replicação apesar de, para isso, alterar o metabolismo celular. São responsáveis por inúmeras doenças em animais e no ser humano (doenças priônicas), todas elas fatais. Essas moléstias apresentam enorme variabilidade quanto ao período de incubação, de alguns meses a 40 anos. Os príons acumulam-se e destroem os neurônios, provocando quadros conhecidos como encefalopatias espongiosiformes. Discute-se a apresentação clínica, epidemiológica e histórica das doenças priônicas. O foco maior de discussão recai, no entanto, na possibilidade teórica da transmissão iatrogênica dos príons por meio das formulações tópicas que utilizam ceramidas (cerebrosídeos) ou placenta de origem bovina, assim como pelo risco representado por alguns procedimentos dermatológicos, como transplantes da pele e implantes de colágeno.<br>A prion is a protein that is capable of self replication, thereby altering a cell's metabolism. It is responsible for a number of human and animal diseases (prionic diseases), all of which are always lethal. These diseases have enormous variability in their incubation periods, ranging from a few months to forty years. Prions accumulate and destroy nerve cells, causing spongiform encephalopathy. We discuss the clinical picture, epidemiology, and historical background of prionic diseases. The major focus of the discussion lies, however, on the theoretical possibility of iatrogenic transmission of prion infection due to topical formulations using ceramides (cerebrosides) or placenta of bovine origin, as well as the risk represented by some dermatological procedures such as skin grafts and collagen implants