Human eosinophil adhesion and degranulation stimulated with eotaxin and RANTES in vitro: Lack of interaction with nitric oxide

<p>Abstract</p> <p>Background</p> <p>Airway eosinophilia is considered a central event in the pathogenesis of asthma. The toxic components of eosinophils are thought to be important in inducing bronchial mucosal injury and dysfunction. Previous studies have suggested an interaction between nitric oxide (NO) and chemokines in modulating eosinophil functions, but this is still conflicting. In the present study, we have carried out functional assays (adhesion and degranulation) and flow cytometry analysis of adhesion molecules (VLA-4 and Mac-1 expression) to evaluate the interactions between NO and CC-chemokines (eotaxin and RANTES) in human eosinophils.</p> <p>Methods</p> <p>Eosinophils were purified using a percoll gradient followed by immunomagnetic cell separator. Cell adhesion and degranulation were evaluated by measuring eosinophil peroxidase (EPO) activity, whereas expression of Mac-1 and VLA-4 was detected using flow cytometry.</p> <p>Results</p> <p>At 4 h incubation, both eotaxin (100 ng/ml) and RANTES (1000 ng/ml) increased by 133% and 131% eosinophil adhesion, respectively. L-NAME alone (but not D-NAME) also increased the eosinophil adhesion, but the co-incubation of L-NAME with eotaxin or RANTES did not further affect the increased adhesion seen with chemokines alone. In addition, L-NAME alone (but not D-NAME) caused a significant cell degranulation, but it did not affect the CC-chemokine-induced cell degranulation. Incubation of eosinophils with eotaxin or RANTES, in absence or presence of L-NAME, did not affect the expression of VLA-4 and Mac-1 on eosinophil surface. Eotaxin and RANTES (100 ng/ml each) also failed to elevate the cyclic GMP levels above baseline in human eosinophils.</p> <p>Conclusion</p> <p>Eotaxin and RANTES increase the eosinophil adhesion to fibronectin-coated plates and promote cell degranulation by NO-independent mechanisms. The failure of CC-chemokines to affect VLA-4 and Mac-1 expression suggests that changes in integrin function (avidity or affinity) are rather involved in the enhanced adhesion.</p

Trichomonas vaginalis: Clinical relevance, pathogenicity and diagnosis

Trichomonas vaginalis is the etiological agent of trichomoniasis, the most prevalent non-viral sexually transmitted disease worldwide. Trichomoniasis is a widespread, global health concern and occurring at an increasing rate. Infections of the female genital tract can cause a range of symptoms, including vaginitis and cervicitis, while infections in males are generally asymptomatic. The relatively mild symptoms, and lack of evidence for any serious sequelae, have historically led to this disease being under diagnosed, and under researched. However, growing evidence that T. vaginalis infection is associated with other disease states with high morbidity in both men and women has increased the efforts to diagnose and treat patients harboring this parasite. The pathology of trichomoniasis results from damage to the host epithelia, caused by a variety of processes during infection and recent work has highlighted the complex interactions between the parasite and host, commensal microbiome and accompanying symbionts. The commercial release of a number of nucleic acid amplification tests (NAATs) has added to the available diagnostic options. Immunoassay based Point of Care testing is currently available, and a recent initial evaluation of a NAAT Point of Care system has given promising results, which would enable testing and treatment in a single visit

ICAR: endoscopic skull‐base surgery

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Flow boiling in a four-compartment heat sink for high-heat flux cooling: A parametric study

Semiconductor devices and microelectronic devices are widely used in many applications such as central processing units. These devices produce a huge amount of heat that must be dissipated properly because their operation is sensitive to operating temperature. Under high operating temperatures, physical damage is expected because of thermal stresses harming the structure of the components and increasing the failure rate. The thermal management of these devices is mandatory to fulfill the recommended operating conditions. The complexity of applying even the most powerful single-phase liquid cooling arrangement is that the semiconductor component temperature increases linearly with increasing heat dissipation rate. Consequently, the temperature of the device could reach higher than the maximum temperature limit. Unlike the single-phase flow, the two-phase flow boiling–cooling system can provide more robust thermal management, uniform temperature distribution over the surface and high heat dissipation by the latent heat. Hence, the flow boiling in microscale devices is an effective cooling technique for high dense-power electronic components. The current study used ethanol, acetone, and Novec-7000 coolants with high, medium, and low boiling points, respectively to study the flow boiling in a microchannel device. The effects of the volumetric flow rate and heat flux were experimentally investigated. A graphite sheet was used as thermal interface material (TIM) for further enhancing the heat dissipation, and wall temperature uniformity was assessed under boiling conditions. The Novec-7000 coolant showed outstanding cooling capabilities under ultra-high-heat flux conditions. When TIM was used, effective heat flux increased by 0.62% and 1.62% for acetone and Novec-7000, respectively. Moreover, the experimental results showed that the boiling point is a critical parameter in the system performance of flow boiling–cooling