17,497 research outputs found
The Immune System
Modern biotherapy has been in use for some 30 years. The first types of biotherapy were nonspecific stimulators of the immune response, but advances in genetic engineering are allowing the mass production of pure biological products which are now being tested as pharmaceutical agents. Biotherapy connotes the administration of products (1) that are coded by the mammalian genome; (2) that modify the expression of mammalian genes; or (3) that stimulate the immune system. In this chapter the discussion of the immune system will be limited primarily to topics relevant to cancer or autoimmune diseases. Because understanding the new biological agents requires an understanding of both the immune response and the molecular basis of oncogenesis, this chapter first presents a summary of the structure and function of the immune system. Following a discussion of immune responses, and the cells involved in these responses, will be a discussion on the current concepts of oncogenesis, particularly oncogenes and growth factors. Because research efforts are beginning to identify many biological proteins as having a role in autoimmune and other diseases, a brief introduction to autoimmune diseases is also included at the end of the chapter
Shock-Free Wave Propagation in Gauge Theories
We present the shock-free wave propagation requirements for massless fields.
First, we briefly argue how the "completely exceptional" approach, originally
developed to study the characteristics of hyperbolic systems in 1+1 dimensions,
can be generalized to higher dimensions and used to describe propagation
without emerging shocks, with characteristic flow remaining parallel along the
waves. We then study the resulting requirements for scalar, vector,
vector-scalar and gravity models and characterize physically acceptable actions
in each case.Comment: 30 pages, LaTeX, no figure
Feasibility of Hair Collection for Cortisol Measurement in Population Research on Adolescent Health
Background: Black–White disparities in adolescent health are widespread and thought to be explained, in part, by exposure to chronic stress. Cortisol assayed from hair is increasingly recognized as a valid and reliable measure for chronic physiological stress, but the feasibility of collecting hair among large probability samples of diverse adolescents is unknown.
Purpose: The aim of the study was to investigate participation in hair collection for cortisol analyses in a probability sample of racially and socioeconomically diverse adolescents, including the extent to which sociodemographic factors and adverse exposures were associated with participation.
Methods: The study included a probability sample of 516 adolescents conducted in conjunction with a prospective cohort study on adolescent health. Data were collected over 1 week via in-home interviews, ecological momentary assessment, global positioning system methods, and in-home hair collection at the end of the week.
Results: Of the 516 eligible youth, 471 (91.3%) participated in the hair collection. Of the 45 youth who did not provide hair samples, 18 had insufficient hair, 25 refused, and 2 did not participate for unknown reasons. Multivariable logistic regression results indicated that non-Hispanic Black youth were less likely than their non-Hispanic White peers to participate due to insufficient hair or refusal (OR = 0.24, 95% CI [0 .09, 0.60]). Despite lower rates of participation, the proportion of Black youth in the participating sample was representative of the study area. No significant differences in participation were found by other sociodemographic characteristics or adverse exposures.
Conclusions: Hair collection for cortisol measurement is feasible among a probability sample of racially and socioeconomically diverse adolescents. Hair cortisol analyses may accelerate research progress to understand the biological and psychosocial bases of health disparities
Effect of Perceived Stress on Cytokine Production in Healthy College Students
Chronic psychological stress impairs antibody synthesis following influenza vaccination. Chronic stress also increases circulating levels of proinflammatory cytokines and glucocorticoids in elders and caregivers, which can impair antibody synthesis. The purpose of this study was to determine whether psychological stress increases ex vivo cytokine production or decreases glucocorticoid sensitivity (GCS) of peripheral blood leukocytes from healthy college students. A convenience sample of Reserve Officer Training Corps (ROTC) students completed the Perceived Stress Scale (PSS). Whole blood was incubated in the presence of influenza vaccine and dexamethasone to evaluate production of interleukin-6 (IL-6), interleukin-1-beta (IL-1β), tumor necrosis factor-alpha (TNF-α), and interferon-gamma (IFN-γ). Multiple regression models controlling for age, gender, and grade point average revealed a negative relationship between PSS and GCS for vaccine-stimulated production of IL-1β, IL-6, and TNF-α. These data increase our understanding of the complex relationship between chronic stress and immune function
Storage Conditions and Passages Alter IL-6 Secretion in C26 Adenocarcinoma Cell Lines
The C26 adenocarcinoma tumor line is frequently used to establish peripheral tumors in mice for the study of cancer cachexia and cancer-related fatigue. Recently, we have noticed a progressive decline in the effects of tumor growth on our biological and behavioral measures in the tumor-bearing mice. Therefore, we compared effects of three aliquots of the C26 tumor cell line that differed in storage condition and number of passages on cytokine secretion, tumor growth, weight loss and fatigue behavior. Three aliquots of the C26 tumor line were selected as alpha (α), beta (β), and gamma (γ). Aliquot α was an original C26 stock line that had been stored at −80 °C. Aliquot β was stored in liquid nitrogen. Aliquot γ was taken from aliquot β and passaged three times. The three aliquots of the C26 tumor line showed differences in IL-6 mRNA and protein secretion in vitro, with aliquot β showing the greatest IL-6 secretion. These differences were mirrored in vivo. Plasma IL-6 levels were elevated in all tumor bearing mice but was greatest in group β mice. Carcass weight was decreased in all three tumor groups. Brain expression of IL-1β mRNA was greatest in group β and group β demonstrated the greatest decline in running activity at day 19. Storage conditions and number of passages influence C26 tumor cell secretion of cytokines. Variations in C26 aliquots may explain differences observed between laboratories using the same cell line. We recommend always storing cell lines in liquid nitrogen and limiting the number of passages before use in experiments
Ubiquinol Reduces Muscle Wasting but Not Fatigue in Tumor-Bearing Mice
Purpose: Fatigue is the most common and distressing symptom reported by cancer patients during and after treatment. Tumor growth increases oxidative stress and cytokine production, which causes skeletal muscle wasting and cardiac dysfunction. The purpose of this study was to determine whether treatment with the antioxidant ubiquinol improves muscle mass, cardiac function, and behavioral measures of fatigue in tumor-bearing mice. Method: Adult female mice were inoculated with colon26 tumor cells. Half the control and tumor-bearing mice were administered ubiquinol (500 mg/kg/day) in their drinking water. Voluntary wheel running (i.e., voluntary running activity [VRA]) and grip strength were measured at Days 0, 8, 14, and 17 of tumor growth. Cardiac function was measured using echocardiography on Day 18 or 19. Biomarkers of inflammation, protein degradation, and oxidative stress were measured in serum and heart and gastrocnemius tissue. Results: VRA and grip strength progressively declined in tumor-bearing mice. Muscle mass and myocardial diastolic function were decreased, and expression of proinflammatory cytokines was increased in serum and muscle and heart tissue on Day 19 of tumor growth. Oxidative stress was present only in the heart, while biomarkers of protein degradation were increased only in the gastrocnemius muscle. Ubiquinol increased muscle mass in the tumor-bearing and control animals but had no effect on the expression of biomarkers of inflammation, protein degradation, or oxidative stress or on behavioral measures of fatigue
Evocative computing – creating meaningful lasting experiences in connecting with the past
We present an approach – evocative computing – that demonstrates how ‘at hand’ technologies can be ‘picked up’ and used by people to create meaningful and lasting experiences, through connecting and interacting with the past. The approach is instantiated here through a suite of interactive technologies configured for an indoor-outdoor setting that enables groups to explore, discover and research the history and background of a public cemetery. We report on a two-part study where different groups visited the cemetery and interacted with the digital tools and resources. During their activities serendipitous uses of the technology led to connections being made between personal memo-ries and ongoing activities. Furthermore, these experiences were found to be long-lasting; a follow-up study, one year later, showed them to be highly memorable, and in some cases leading participants to take up new directions in their work. We discuss the value of evocative computing for enriching user experiences and engagement with heritage practices
Current status of gene therapy for breast cancer: progress and challenges
Breast cancer is characterized by a series of genetic mutations and is therefore ideally placed for gene therapy intervention. The aim of gene therapy is to deliver a nucleic acid-based drug to either correct or destroy the cells harboring the genetic aberration. More recently, cancer gene therapy has evolved to also encompass delivery of RNA interference technologies, as well as cancer DNA vaccines. However, the bottleneck in creating such nucleic acid pharmaceuticals lies in the delivery. Deliverability of DNA is limited as it is prone to circulating nucleases; therefore, numerous strategies have been employed to aid with biological transport. This review will discuss some of the viral and nonviral approaches to breast cancer gene therapy, and present the findings of clinical trials of these therapies in breast cancer patients. Also detailed are some of the most recent developments in nonviral approaches to targeting in breast cancer gene therapy, including transcriptional control, and the development of recombinant, multifunctional bio-inspired systems. Lastly, DNA vaccines for breast cancer are documented, with comment on requirements for successful pharmaceutical product development
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