China
Africa
Explore chapters and articles related to this topic
Lifetime Data and Concepts
Published in Prabhanjan Narayanachar Tattar, H. J. Vaman, Survival Analysis, 2022
Prabhanjan Narayanachar Tattar, H. J. Vaman
This study consists of data from a placebo controlled trial of gamma interferon in chronic granulotomous disease (CGD). It consists of data on the time to serious infections observed through end of study for each patient. This study is an example where the event can occur more than once to the patient. After the infection is removed or treated with, we observe the patient up to the time when the infection recurs and again give the treatment. The goal is to understand if the gamma interferon treatment extends the time to recurrence of the infection.
The Viruses
Published in Julius P. Kreier, Infection, Resistance, and Immunity, 2022
Interferons are a family of proteins produced by host cells in response to a variety of stimuli including viral infection. The formation of double stranded viral RNA within the infected cell induces the formation of interferons. Interferons may induce an antiviral state within many cells in the body. The production of interferons is a basic defense mechanism of animals against viral infections. There are three distinct types of interferons (alpha, beta, and gamma). Alpha and beta interferons bind to specific cell receptors and cause cells to produce proteins that have antiviral properties. For example, 2–5A synthetase causes the activation of nucleases that mediate degradation of viral RNAs. Gamma interferon, which is produced by leukocytes, causes the activation of macrophages and the production of antiviral cytokines which amplify the antiviral immune response.
Tuberculosis Transmission Control
Published in Lloyd N. Friedman, Martin Dedicoat, Peter D. O. Davies, Clinical Tuberculosis, 2020
We have presented some of experimental evidence favoring FAST and GUV, for example, but demonstrating the efficacy of most accepted interventions for preventing Mtb infection or disease in high burden settings has proven difficult. Sources of Mtb infection are common in the community; tuberculin reactivity is common among healthcare workers and in the community and confounded by BCG immunization. Newer gamma interferon release assays were designed to circumvent BCG confounding, but are expensive, complex tests, with limited routine application thus far in high burden settings.77Mtb contamination of air cannot be routinely measured, and quantifying infectiousness is even harder. Unlike drug trials, randomized-controlled clinical trials for TB prevention strategies are rare. In short, most interventions to prevent TB transmission in healthcare facilities are not supported by the highest level of data showing reduced infection or disease.
IL-23 inhibition for the treatment of psoriatic arthritis
Published in Expert Opinion on Biological Therapy, 2022
Raagav Mohanakrishnan, Secia Beier, Atul Deodhar
PsA is an immune mediated disease leading to synovial membrane and entheseal inflammation, characterized by increased vascularization and innate and adaptive immune cell infiltration [14]. The innate immune system consists of physical surfaces (skin, mucous membranes) on the human body that serve as barriers to organisms such as bacteria and viruses. It also consists of immune system cells such as neutrophils and natural killer cells that provide nonspecific defense to foreign organisms [15]. In contrast, the adaptive immune system consists of T and B lymphocytes that provide more targeted defense against organisms [15]. T cells have the ability to activate various other mechanisms within the immune system, including B cells which are able to become plasma cells and form antibodies. More specifically, T cells are divided into T helper cells, and cytotoxic T cells; and T helper cells further specialize into Th1, Th2, Th17, and T-Reg cells. T helper cells release multiple cytokines (gamma interferon, tumor necrosis factor alfa, IL-17 etc.), that are then able to activate various parts of the immune system [15]. These cytokines are major players in the human immune system and have also been implicated in immune-mediated processes such as PsA.
Emerging and potential treatment options for sarcoidosis
Published in Expert Opinion on Orphan Drugs, 2018
Debabrata Bandyopadhyay, Marc A. Judson
Ideally, effective pharmacotherapy should target the pathogenic process causing the disease. Unfortunately, the exact immunopathogenesis of sarcoidosis is currently unclear. The non-caseating granuloma is the histopathological landmark of sarcoidosis. Although the specific details concerning the formation of the sarcoid granuloma are not completely known, sarcoidosis granulomas are thought to develop from an interplay of antigen presenting cells (APCs) and CD-4 + T lymphocytes in presence of certain putative antigens. This process is aided by cytokines, most notably interleukin 12 (IL-12), IL-18, and gamma-interferon (IFN-γ). These cytokines cause polarization and proliferation of T cells to a T-helper cell-1 phenotype (Th-1). Th-1-cell activation also produces IL-2. Autocrine IL-2 activation results in a further clonal proliferation of CD-4 + T lymphocytes. Many other cytokines are released in this process such as IL-4, IL-6, IL-8 that lead to monocyte recruitment and differentiation into macrophages [9]. Increased production of TNF-α by activated monocyte-macrophages plays a pivotal role in granuloma formation. It is the principal mediator of inflammation and cellular immune response among the various cytokines. TNF-α upregulates the activity of IL-12 and IL-15 surface receptor. These events result in CD4 + T cell proliferation. TNF-α also liberates APCs from inhibition by macrophages; thus, TNF-α initiates a self-amplifying inflammatory loop [10]. The activated monocyte-macrophage system and CD-4 + T lymphocytes act synergistically to promote formation of the sarcoid granuloma. As this model of the pathogenesis of sarcoidosis involves numerous cells and cytokines, there are many opportunities for pharmacologic interventions to disrupt this process [11].
On computing estimates of a change-point in the Weibull regression hazard model
Published in Journal of Applied Statistics, 2018
Oscar Palmeros, Jose A. Villaseñor, Elizabeth González
Based on the Kaplan–Meier estimator for the survival times of gamma interferon patients and placebo patients, Figure 1 shows two separated groups with different survival probability behaviors through time. Notice that gamma interferon treatment has an overall protective effect. Moreover, at the time of interim analysis, 20 of the 65 placebo patients and 7 of the 63 patients on gamma interferon, had experienced at least one serious infection.