209 research outputs found
Neutrophil Isolation Protocol
Neutrophil polymorphonuclear granulocytes (PMN) are the most abundant leukocytes in humans and among the first cells to arrive on the site of inflammatory immune response. Due to their key role in inflammation, neutrophil functions such as locomotion, cytokine production, phagocytosis, and tumor cell combat are extensively studied. To characterize the specific functions of neutrophils, a clean, fast, and reliable method of separating them from other blood cells is desirable for in vitro studies, especially since neutrophils are short-lived and should be used within 2-4 hours of collection. Here, we demonstrate a standard density gradient separation method to isolate human neutrophils from whole blood using commercially available separation media that is a mixture of sodium metrizoate and Dextran 500. The procedure consists of layering whole blood over the density gradient medium, centrifugation, separation of neutrophil layer, and lysis of residual erythrocytes. Cells are then washed, counted, and resuspended in buffer to desired concentration. When performed correctly, this method has been shown to yield samples of >95% neutrophils with >95% viability
The Assessment of Mathematics and Science Teacher Quality
The purpose of this study was to examine the types of instruments being used to document mathematics and science teacher quality characteristics in 48 nationally funded mathematics and science education awards. Each of the 48 projects operationalized teacher quality and determined how to assess it. The main research questions examined the instruments awardees used to gather data on mathematics and science teacher quality, and the main characteristics of teachers examined by awardees. Results showed that awardees most frequently used surveys or questionnaires to assess characteristics of mathematics and science teacher quality. The most common teacher characteristics examined by awardees\u27 included teacher behaviors, practices, and beliefs, followed by the assessment of subject and pedagogical knowledge, and the documentation of mathematics and science teachers\u27 certification. A few new instruments were under development and in use to assess characteristics of teacher quality. Detailed information on the development and psychometric properties of the instruments used for these examinations was not available from the reports. Because awardees were at different stages in their funded activities and data collection efforts were ongoing at the time of this analysis, this study offers a preliminary and formative review of the use of assessments to document mathematics and science teacher quality characteristics among these awards
Continuing to Confront COPD International Physician Survey: Physician Knowledge and Application of COPD Management Guidelines in 12 Countries
AIM: Utilizing data from the Continuing to Confront COPD (chronic obstructive pulmonary disease) International Physician Survey, this study aimed to describe physicians\u27 knowledge and application of the GOLD (Global initiative for chronic Obstructive Lung Disease) Global Strategy for the Diagnosis, Management and Prevention of COPD diagnosis and treatment recommendations and compare performance between primary care physicians (PCPs) and respiratory specialists.
MATERIALS AND METHODS: Physicians from 12 countries were sampled from in-country professional databases; 1,307 physicians (PCP to respiratory specialist ratio three to one) who regularly consult with COPD, emphysema, or chronic bronchitis patients were interviewed online, by telephone or face to face. Physicians were questioned about COPD risk factors, prognosis, diagnosis, and treatment, including knowledge and application of the GOLD global strategy using patient scenarios.
RESULTS:Physicians reported using spirometry routinely (PCPs 82%, respiratory specialists 100%; P\u3c0.001) to diagnose COPD and frequently included validated patient-reported outcome measures (PCPs 67%, respiratory specialists 81%; P\u3c0.001). Respiratory specialists were more likely than PCPs to report awareness of the GOLD global strategy (93% versus 58%, P\u3c0.001); however, when presented with patient scenarios, they did not always perform better than PCPs with regard to recommending GOLD-concordant treatment options. The proportion of PCPs and respiratory specialists providing first- or second-choice treatment options concordant with GOLD strategy for a GOLD B-type patient was 38% versus 67%, respectively. For GOLD C and D-type patients, the concordant proportions for PCPs and respiratory specialists were 40% versus 38%, and 57% versus 58%, respectively.
CONCLUSION: This survey of physicians in 12 countries practicing in the primary care and respiratory specialty settings showed high awareness of COPD-management guidelines. Frequent use of guideline-recommended COPD diagnostic practices was reported; however, gaps in the application of COPD-treatment recommendations were observed, warranting further evaluation to understand potential barriers to adopt guideline recommendations
Health Behaviors and Their Correlates Among Participants in the Continuing to Confront COPD International Patient Survey
Background and aims: We used data from the Continuing to Confront COPD International Patient Survey to test the hypothesis that patients with COPD who report less engagement with their disease management are also more likely to report greater impact of the disease.
Methods: This was a population-based, cross-sectional survey of 4,343 subjects aged ≥ 40 years from 12 countries, fulfilling a case definition of COPD based on self-reported physician diagnosis or symptomatology. The impact of COPD was measured with COPD Assessment Test, modified Medical Research Council Dyspnea Scale, and hospital admissions and emergency department visits for COPD in the prior year. The 13-item Patient Activation Measure (PAM-13) instrument and the 8-item Morisky Medication Adherence Scale (MMAS-8) were used to measure patient disease engagement and medication adherence, respectively.
Results: Twenty-eight percent of subjects reported being either disengaged or struggling with their disease (low engagement: PAM-13 levels 1 and 2), and 35% reported poor adherence (MMAS-8 \u3c 6). In univariate analyses, lower PAM-13 and MMAS-8 scores were significantly associated with poorer COPD-specific health status, greater breathlessness and lower BMI (PAM-13 only), less satisfaction with their doctor’s management of COPD, and more emergency department visits. In multivariate regression models, poor satisfaction with their doctor’s management of COPD was significantly associated with both low PAM-13 and MMAS-8 scores; low PAM-13 scores were additionally independently associated with higher COPD Assessment Test and modified Medical Research Council scores and low BMI (underweight).
Conclusion: Poor patient engagement and medication adherence are frequent and associated with worse COPD-specific health status, higher health care utilization, and lower satisfaction with health care providers. More research will be needed to better understand what factors can be modified to improve medication adherence and patient engagement
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Interleukin-2 induces the in vitro maturation of human pluripotent stem cell-derived intestinal organoids.
Human pluripotent stem cell (hPSC)-derived intestinal organoids (hIOs) form 3D structures organized into crypt and villus domains, making them an excellent in vitro model system for studying human intestinal development and disease. However, hPSC-derived hIOs still require in vivo maturation to fully recapitulate adult intestine, with the mechanism of maturation remaining elusive. Here, we show that the co-culture with human T lymphocytes induce the in vitro maturation of hIOs, and identify STAT3-activating interleukin-2 (IL-2) as the major factor inducing maturation. hIOs exposed to IL-2 closely mimic the adult intestinal epithelium and have comparable expression levels of mature intestinal markers, as well as increased intestine-specific functional activities. Even after in vivo engraftment, in vitro-matured hIOs retain their maturation status. The results of our study demonstrate that STAT3 signaling can induce the maturation of hIOs in vitro, thereby circumventing the need for animal models and in vivo maturation
Modern Interpretation of Giant Cell Tumor of Bone: Predominantly Osteoclastogenic Stromal Tumor
Owing to striking features of numerous multinucleated cells and bone destruction, giant cell tumor (GCT) of bone, often called as osteoclastoma, has drawn major attractions from orthopaedic surgeons, pathologists, and radiologists. The name GCT or osteoclastoma gives a false impression of a tumor comprising of proliferating osteoclasts or osteoclast precursors. The underlying mechanisms for excessive osteoclastogenesis are intriguing and GCT has served as an exciting disease model representing a paradigm of osteoclastogenesis for bone biologists. The modern interpretation of GCT is predominantly osteoclastogenic stromal cell tumors of mesenchymal origin. A diverse array of inflammatory cytokines and chemokines disrupts osteoblastic differentiation and promotes the formation of excessive multi-nucleated osteoclastic cells. Pro-osteoclastogenic cytokines such as receptor activator of nuclear factor kappa-B ligand (RANKL), interleukin (IL)-6, and tumor necrosis factor (TNF) as well as monocyte-recruiting chemokines such as stromal cell-derived factor-1 (SDF-1) and monocyte chemoattractant protein (MCP)-1 participate in unfavorable osteoclastogenesis and bone destruction. This model represents a self-sufficient osteoclastogenic paracrine loop in a localized area. Consistent with this paradigm, a recombinant RANK-Fc protein and bisphosphonates are currently being tried for GCT treatment in addition to surgical excision and conventional topical adjuvant therapies
Heat-Induced Structural Changes Affect OVA-Antigen Processing and Reduce Allergic Response in Mouse Model of Food Allergy
BACKGROUND AND AIMS: The egg protein ovalbumin (OVA) belongs to six most frequent food allergens. We investigated how thermal processing influences its ability to induce allergic symptoms and immune responses in mouse model of food allergy. METHODOLOGY/PRINCIPAL FINDINGS: Effect of increased temperature (70°C and 95°C) on OVA secondary structure was characterized by circular dichroism and by the kinetics of pepsin digestion with subsequent HPLC. BALB/c mice were sensitized intraperitoneally and challenged with repeated gavages of OVA or OVA heated to 70°C (h-OVA). Levels of allergen-specific serum antibodies were determined by ELISA (IgA and IgGs) or by β-hexosaminidase release test (IgE). Specific activities of digestive enzymes were determined in brush border membrane vesicles of jejunal enterocytes. Cytokine production and changes in regulatory T cells in mesenteric lymph nodes and spleen were assessed by ELISA and FACS. Heating of OVA to 70°C caused mild irreversible changes in secondary structure compared to boiling to 95°C (b-OVA), but both OVA treatments led to markedly different digestion kinetics and Tregs induction ability in vitro, compared to native OVA. Heating of OVA significantly decreased clinical symptoms (allergic diarrhea) and immune allergic response on the level of IgE, IL-4, IL-5, IL-13. Furthermore, h-OVA induced lower activities of serum mast cell protease-1 and enterocyte brush border membrane alkaline phosphatase as compared to native OVA. On the other hand h-OVA stimulated higher IgG2a in sera and IFN-γ secretion by splenocytes. CONCLUSIONS: Minor irreversible changes in OVA secondary structure caused by thermal processing changes both its digestion and antigenic epitopes formation, which leads to activation of different T cell subpopulations, induces shift towards Th1 response and ultimately reduces its allergenicity
Exploring Cell Tropism as a Possible Contributor to Influenza Infection Severity
Several mechanisms have been proposed to account for the marked increase in severity of human infections with avian compared to human influenza strains, including increased cytokine expression, poor immune response, and differences in target cell receptor affinity. Here, the potential effect of target cell tropism on disease severity is studied using a mathematical model for in-host influenza viral infection in a cell population consisting of two different cell types. The two cell types differ only in their susceptibility to infection and rate of virus production. We show the existence of a parameter regime which is characterized by high viral loads sustained long after the onset of infection. This finding suggests that differences in cell tropism between influenza strains could be sufficient to cause significant differences in viral titer profiles, similar to those observed in infections with certain strains of influenza A virus. The two target cell mathematical model offers good agreement with experimental data from severe influenza infections, as does the usual, single target cell model albeit with biologically unrealistic parameters. Both models predict that while neuraminidase inhibitors and adamantanes are only effective when administered early to treat an uncomplicated seasonal infection, they can be effective against more severe influenza infections even when administered late
Characteristics and properties of nano-LiCoO2 synthesized by pre-organized single source precursors: Li-ion diffusivity, electrochemistry and biological assessment
Background: LiCoO2 is one of the most used cathode materials in Li-ion batteries. Its conventional synthesis requires high temperature (>800 degrees C) and long heating time (>24 h) to obtain the micronscale rhombohedral layered high-temperature phase of LiCoO2 ( HT-LCO). Nanoscale HT-LCO is of interest to improve the battery performance as the lithium (Li+) ion pathway is expected to be shorter in nanoparticles as compared to micron sized ones. Since batteries typically get recycled, the exposure to nanoparticles during this process needs to be evaluated. Results: Several new single source precursors containing lithium (Li+) and cobalt (Co2+) ions, based on alkoxides and aryloxides have been structurally characterized and were thermally transformed into nanoscale HT-LCO at 450 degrees C within few hours. The size of the nanoparticles depends on the precursor, determining the electrochemical performance. The Li-ion diffusion coefficients of our - LiCoO2 nanoparticles improved at least by a factor of 10 compared to commercial one, while showing good reversibility upon charging and discharging. The hazard of occupational exposure to nanoparticles during battery recycling was investigated with an in vitro multicellular lung model. Conclusions: Our heterobimetallic single source precursors allow to dramatically reduce the production temperature and time for HT-LCO. The obtained nanoparticles of LiCoO2 have faster kinetics for Li+ insertion/extraction compared to microparticles. Overall, nano-sized - LiCoO2 particles indicate a lower cytotoxic and (pro-)inflammogenic potential in vitro compared to their micron-sized counterparts. However, nanoparticles aggregate in air and behave partially like microparticles
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