Unexplained Aspects of Anemia of Inflammation

Anemia of inflammation (AI), also known as anemia of chronic inflammation or anemia of chronic disease was described over 50 years ago as anemia in association with clinically overt inflammatory disease, and the findings of low plasma iron, decreased bone marrow sideroblasts and increased reticuloendothelial iron. Pathogenic features underlying AI include a mild shortening of red cell survival, impaired erythropoietin production, blunted responsiveness of the marrow to erythropoietin, and impaired iron metabolism mediated by inflammatory cytokines and the iron regulatory peptide, hepcidin. Despite marked recent advances in understanding AI, gaps remain, including understanding of the pathogenesis of AI associated with “noninflammatory” or mildly inflammatory diseases, the challenge of excluding iron deficiency anemia in the context of concomitant inflammation, and understanding more precisely the contributory role of hepcidin in the development of AI in human inflammatory diseases

Non-invasive monitoring of pharmacokinetics and pharmacodynamics for pharmacological drug profiling in children and adolescents

This thesis describes the potential role of non-invasive measurement of pharmacokinetics (pk) and pharmacodynamics (pd) in the research and development of central nervous system (cns) stimulants or depressants for children and adolescents. First, we evaluated the feasibility of using saliva as an alternative to plasma in two studies on psychostimulants (caffeine and methylphenidate). Second, neuropsychological and neurophysiological functions were measured longitudinally using the NeuroCart, a battery of tests developed at the Centre for Human Drug Research (chdr, Leiden, The Netherlands) that includes non-invasive tests for alertness, visuomotor coordination, motor control, memory, and subjective drug effects. Using a non-invasive approach, age-dependent differences in alcohol pk and pd were evaluated between healthy adolescents and adults. This thesis concludes with the report of two clinical trials that were designed to evaluate age-appropriate formulations of sedative drugs that have the potential for use in children.The publication of this thesis was financially supported by the foundation Centre for Human Drug Research (chdr), Leiden, the NetherlandsUBL - phd migration 201

Revolutionizing history education : using augmented reality games to teach histories

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Comparative Media Studies, 2005.Includes bibliographical references (leaves 154-162).In an ever-changing present of multiple truths and reconfigured histories, people need to be critical thinkers. Research has suggested the potential for using augmented reality (AR) games- location-based games that use wireless handheld devices to provide virtual game information in a physical environment-as educational tools. I designed "Reliving the Revolution" as a model for using AR games to teach historic inquiry, decision-making, and critical thinking skills. "Reliving the Revolution" takes place in Lexington, MA, the site of the Battle of Lexington (American Revolution) and simulates the activities of a historian, such as evidence collection and interpretation. Participants interact with virtual historic figures and gather virtual testimonials and evidence on the Battle, each triggered by GPS to appear on the handheld devices depending on one's specific location on or around the Lexington Common. The participants collect differing evidence based on their historic role in the game (Minuteman soldier, loyalist, African American/Minuteman soldier, or British soldier) and then collaboratively evaluate who fired the first shot to start the Battle of Lexington.(cont.) I envision "Reliving the Revolution" not as a standalone educational solution, but as an activity integrated into a broader history curriculum that teaches students how to approach and evaluate complex social problems. This thesis provides a detailed rationale for each of my design choices, as well as an assessment of each choice based on the results of iterative game testing. In my analysis of the game's design, I focus specifically on four game elements: (1) collaborative, (2) role-playing, (3) storytelling or narrative elements; and (4) kinesthetic and mobility. Results of trials of the game suggest that "Reliving the Revolution" and similar AR games can enhance the learning of: (1) historical name, places, and themes; (2) historical methodology and the limits to representations of the past; and (3) alternative perspectives and challenges to "master" historical interpretations. The game motivated participants to gather, evaluate, and interpret historical information, devise hypotheses and counter-arguments, and draw informed conclusions.(cont.) My trials also suggested that AR games such as "Reliving the Revolution" can enhance learning because it can: 1. Create an authentic "practice field" for solving problems and using real-world contexts and tools. 2. Increase the potential for collaboration among participants, and enhance opportunities for reflection. 3. Enable participants to take on and express new identities through role-playing. 4. Encourage participants to explore more deeply a physical site and to consider interactions between the real and virtual worlds.by Karen L. Schrier.S.M

Pitting of malaria parasites and spherocyte formation

BACKGROUND: A high prevalence of spherocytes was detected in blood smears of children enrolled in a case control study conducted in the malaria holoendemic Lake Victoria basin. It was speculated that the spherocytes reflect intraerythrocytic removal of malarial parasites with a concurrent removal of RBC membrane through a process analogous to pitting of intraerythrocytic inclusion bodies. Pitting and re-circulation of RBCs devoid of malaria parasites could be a host mechanism for parasite clearance while minimizing the anaemia that would occur were the entire parasitized RBC removed. The prior demonstration of RBCs containing ring-infected erythrocyte surface antigen (pf 155 or RESA) but no intracellular parasites, support the idea of pitting. METHODS: An in vitro model was developed to examine the phenomenon of pitting and spherocyte formation in Plasmodium falciparum infected RBCs (iRBC) co-incubated with human macrophages. In vivo application of this model was evaluated using blood specimens from patients attending Kisumu Ditrict Hospital. RBCs were probed with anti-RESA monoclonal antibody and a DNA stain (propidium iodide). Flow cytometry and fluorescent microscopy was used to compare RBCs containing both the antigen and the parasites to those that were only RESA positive. RESULTS: Co-incubation of iRBC and tumor necrosis factor-alpha activated macrophages led to pitting (14% ± 1.31% macrophages with engulfed trophozoites) as opposed to erythrophagocytosis (5.33% ± 0.95%) (P < 0.01). Following the interaction, 26.9% ± 8.1% of the RBCs were spherocytes as determined by flow cytometric reduction in eosin-5-maleimide binding which detects RBC membrane band 3. The median of patient RBCs with pitted parasites (RESA+, PI-) was more than 3 times (95,275/μL) that of RESA+, PI+ RBCs (28,365/μL) (P < 0.01). RBCs with pitted parasites showed other morphological abnormalities, including spherocyte formation. CONCLUSION: It is proposed that in malaria holoendemic areas where prevalence of asexual stage parasites approaches 100% in children, RBCs with pitted parasites are re-circulated and pitting may produce spherocytes

Evaluation of the EndoPAT as a Tool to Assess Endothelial Function

Endothelial dysfunction is a potential target for (pharmaceutical) intervention of several systemic pathological conditions. We investigated the feasibility of the EndoPAT to evaluate acute changes in endothelial function with repeated noninvasive measurements and assessed its discriminating power in different populations. Endothelial function was stable over a longer period of time in renally impaired patients (coefficient of variation 13%). Endothelial function in renally impaired and type 2 diabetic patients was not decreased compared to healthy volunteers (2.9 ± 1.4 and 1.8 ± 0.3, resp., versus 1.8 ± 0.5, P > 0.05). The EndoPAT did not detect an effect of robust interventions on endothelial function in healthy volunteers (glucose load: change from baseline 0.08 ± 0.50, 95% confidence interval −0.44 to 0.60; smoking: change from baseline 0.49 ± 0.92, 95% confidence interval −0.47 to 1.46). This suggests that at present the EndoPAT might not be suitable to assess (changes in) endothelial function in early-phase clinical pharmacology studies. Endothelial function as measured by the EndoPAT could be physiologically different from endothelial function as measured by conventional techniques. This should be investigated carefully before the EndoPAT can be considered a useful tool in drug development or clinical practice

Role of chemokines and cytokines in a reactivation model of arthritis in rats induced by injection with streptococcal cell walls

Intraarticular injection of streptococcal cell wall (SCW) antigen followed by intravenous challenge results in a T cellâ mediated monoarticular arthritis in female Lewis rats. Initial studies showed that this reactivation response to intravenous SCW antigen is dependent on the presence of interleukinâ 1 (ILâ 1) and tumor necrosis factor α (TNFâ α) and that the early phase of swelling is neutrophilâ dependent. Neutrophil depletion or passive immunization with antibodies to Pâ selectin or macrophage inflammatory proteinâ 2 reduced the intensity of ankle edema and the influx of neutrophils. After the first few days, however, the arthritic response is mediated primarily by mononuclear cells. Joint tissues showed upâ regulation of mRNA for monocyte chemotactic proteinâ 1 (MCPâ 1), which could be inhibited in part by antiâ ILâ 4; treatment of rats with antibodies to ILâ 4 or MCPâ 1 significantly suppressed development of ankle edema and histopathological evidence of inflammation. Antibodies to interferonâ γ or ILâ 10 had no effect. Treatment with antiâ MCPâ 1 also suppressed influx of 111Inâ labeled T cells into the ankle joint. These data suggest that the late, mononuclearâ dependent phase of SCWâ induced arthritis in female Lewis rats requires cytokines that upâ regulate MCPâ 1, which in turn may facilitate recruitment and extravasation of mononuclear cells into the joint. J. Leukoc. Biol. 63: 359â 363; 1998.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142294/1/jlb0359.pd

Effect of nitric oxide donors on renal tubular epithelial cell-matrix adhesion

Effect of nitric oxide donors on renal tubular epithelial cell-matrix adhesion.BackgroundNitric oxide (NO) and its metabolite, peroxynitrite (ONOO-), are involved in renal tubular cell injury. We postulated that if NO/ONOO- has an effect to reduce cell adhesion to the basement membrane, this may contribute to tubular obstruction and may be partially responsible for the harmful effect of NO on the tubular epithelium during acute renal failure (ARF).MethodsWe examined the effect of the NO donors (z)-1-[2-(2-aminoethyl)-N-(2-ammonioethyl)amino]diazen-1-ium-1,2-diolate (DETA/NO), spermine NONOate (SpNO), and the ONOO- donor 3-morpholinosydnonimine (SIN-1) on cell-matrix adhesion to collagen types I and IV and fibronectin using three renal tubular epithelial cell lines: LLC-PK1, BSC-1, and OK.ResultsIn LLC-PK1 cells, DETA/NO (500 μm) had no effect, and SpNO (500 μm) had a modest effect on cell adhesion compared with controls. Exposure to SIN-1 caused a dose-dependent impairment in cell-matrix adhesion. Similar results were obtained in the different cell types and matrix proteins. The effect of SIN-1 (500 μm) on LLC-PK1 cell adhesion was not associated with either cell death or alteration of matrix protein and was attenuated by either the NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, the superoxide scavenger superoxide dismutase, or the ONOO- scavenger uric acid in a dose-dependent manner.ConclusionsThese results therefore support the possibility that ONOO- generated in the tubular epithelium during ischemia/reperfusion has the potential to impair the adhesion properties of tubular cells, which then may contribute to the tubular obstruction in ARF

Effect of glycine on prelethal and postlethal increases in calpain activity in rat renal proximal tubules

Effect of glycine on prelethal and postlethal increases in calpain activity in rat renal proximal tubules. The effect of glycine on hypoxia- and ionomycin-induced increases in calpain activity in rat proximal tubules was determined. Calpain activity was determined both in vitro and in the intact cell using the fluorescent substrate N-succinyl-Leu-Leu-Val-Tyr-7- amido-4-methyl coumarin (N-succinyl-Leu-Leu-Val-Tyr-AMC) and Western blotting for calpain-specific spectrin breakdown products (BDP), respectively. At 7.5 minutes of hypoxia (prelethal injury model) there was a significant (10-fold) increase in in vitro calpain activity that was not inhibited by glycine. At 15 minutes of hypoxia (postlethal injury model) there was a further increase in calpain activity that was inhibited by glycine. Normoxic tubules incubated with the calcium ionophore ionomy-cin (5 µM) for two minutes and 10 minutes had a significant increase in calpain activity that was not inhibited by glycine. After 15 minutes of hypoxia in the presence of glycine, there was an increase in calpain-specific spectrin breakdown products (BDP) in both Triton X-100 soluble and cytosolic extracts from proximal tubules. Glycine in concentrations up to 10mM had no direct effect on the in vitro calpain activity of purified calpains. The present study demonstrates that: (1) prelethal increases in calpain activity stimulated by hypoxia and ionomycin treatment are not affected by glycine; (2) calpain-mediated spectrin breakdown during hypoxia occurs in the presence of glycine; (3) glycine does prevent the additional postlethal increase in calpain activity probably by maintaining membrane integrity to calcium influx

Medical treatment of ascites in cirrhosis

Medical treatment of cirrhotic ascites is essentially supportive, dictated by the patient's discomfort, impaired cardiovascular or respiratory function and potential for infection. Treatment of ‘simple’ ascites (moderate fluid accumulation, serum albumin > 3.5 g/dl, serum creatinine < 1.5 mg/dl, no electrolyte disturbance) is implemented sequentially. Only 10% of patients respond to dietary sodium restriction and bed rest; most require pharmacotherapy consisting of spironolactone, which increases the proportion of responding patients to 65% and loop diuretics, which may produce clinical improvement in an additional 20% (85% in all); in the remaining 15% of refractory patients, use of novel adjunctive therapies may be attempted. Patients with tense ascites, impaired renal function and electrolyte disturbances merit special consideration before diuretics are introduced. Spironolactone has long been a standard for the treatment of cirrhotic ascites because it directly antagonizes aldosterone. The loop diuretic most frequently added to spironolactone has been furosemide. However, there is preliminary evidence that torasemide may be more effective in some patients. Other investigational agents that may play a role in treatment of patients resistant to conventional drugs include ornipressin (a vasopressin analogue) and atrial natriuretic factor