Assessing experiences of international students in Haiti and Benin

The past two decades have seen an increase in international experiences for engineering students focused on service and research in developing countries. Motivation for these programs reflects the growing recognition that there is a need for creating engineers with greater global awareness [18] who are familiar with the need for integrating solutions to complex problems through interdisciplinary approaches [12]. Of particular interest have been programs in humanitarian engineering that address these needs while at the same time contributing to the attractiveness of engineering, helping to bridge the gender gap that has challenged engineering education, and providing new opportunities to see engineering in a broader global/ethical realm [3], [11], [12], [14], [16], [30].     

Compounds biologically similar to platelet activating factor are present in stored blood components

Agents which prime the neutrophil NADPH oxidase develop during routine storae of whole blood and packed red blood cells. This plasma priming activity can be inhibited by bepafant (WEB 2170), a specific platelet activating factor (PAF) receptor antagonist. Quantitation of the priming agent(s), by a commercially available radioimmunoassay for PAF, reproducibly demonstrated high levels of PAF activity. However, analysis of these plasma samples from stored blood components by gas chromatography/mass spectroscopy did not reveal any 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine. We conclude that the polyclonal antibody to PAF used in these studies may have recognized different epitopes of a family of heterogeneous, biologically active lipids that manifest their effects through the PFA receptor.     

Magnetically Tunable Microwave Filters based on YBCO/YIG/GGG Heterostructures

Superconducting, monolithic magnetically tunable microwave filters have been designed and fabricated demonstrating high tuning ranges (up to 19%) at a center frequency of 10 GHz. These filters are based on fully epitaxial YBa₂Cu₃O₇ (YBCO) thin films grown by pulsed laser deposition onto liquid-phase epitaxy yttrium iron garnet (YIG) layers on gadolinium iron garnet (GGG) substrates. Mechanisms resulting in variations of the bandwidth and insertion losses upon tuning are analyzed and understood in terms of the material properties of YIG and GGG.     

Clinically relevant concentrations of ethanol attenuate primed neutrophil bactericidal activity

PURPOSE: Holmium:YAG lithotripsy fragments stones through a photothermal mechanism. Uric acid when heated is known to be converted into cyanide. We test the hypothesis that holmium: YAG lithotripsy of uric acid calculi produces cyanide. MATERIALS AND METHODS: Human calculi of known uric acid composition were irradiated with holmium:YAG energy in water. Stones received a total holmium:YAG energy of 0 (control), 0.1, 0.25, 0.5, 0.75, 1.0 or 1.25 kJ. The water in which lithotripsy was performed was analyzed for cyanide concentration. A graph was constructed to relate holmium:YAG energy to cyanide production. RESULTS: Holmium:YAG lithotripsy of uric acid calculi in vitro produced cyanide consistently. Cyanide production correlated with total holmium:YAG energy (p <0.001). CONCLUSIONS: Holmium:YAG lithotripsy of uric acid calculi risks production of cyanide. This study raises significant safety issues.     

In vivo treatment with granulocyte colony-stimulating factor results in divergent effects on neutrophil functions measured in vitro

We have studied the effects of granulocyte colony-stimulating factor (G-CSF) administration to normal individuals on a variety of functional and biochemical neutrophil characteristics that relate to host defense. G-CSF adversely affected neutrophil (polymorphonuclear leukocyte [PMN]) chemotaxis. While this could be partially explained by reduced assembly of neutrophil F-actin, we also recognized an elevated cytosolic calcium mobilization and a normal upregulation of neutrophil CD11b. G-CSF resulted in reduced PMN killing of Staphylococcus aureus with a 10:1 (bacteria:neutrophil) ratio and normal killing with a 1:1 ratio. In association with this, we demonstrated divergent effects on the respiratory burst of intact cells and divergent effects on the content of marker proteins for neutrophil granules. While G-CSF may have resulted in increased content of cytochrome b558 in the cell membrane, it did not alter the amounts of cytosolic oxidase components. After therapy, there was normal content of the azurophilic granule marker, myeloperoxidase, decreased content of the specific granule marker, lactoferrin, and normal content of lysozyme (found in both granules classes). Finally, G-CSF therapy markedly reduced the apoptotic rate of the isolated neutrophil. Therefore, considering disparate functional and biochemical activities, the real benefit of G-CSF therapy may lie in enhanced number and survival of neutrophils.     

Treatment of articular cartilage defects in athletes: an analysis of functional outcome and lesion appearance

This article characterizes chondral injuries and reviews the results of microfracture treatment in high-level competitive and recreational athletes. Thirty-eight high-level and 140 recreational athletes completed functional questionnaires preoperatively and yearly postoperatively, recording symptoms, function, and activity level. Second-look arthroscopy tapes were available in 26 high-level and 54 recreational athletes. The mean follow-up for the high-level athletes was 3.7 +/- 1.4 years. Chondral defects averaged 223 +/- 180 mm2. Lesion size and follow-up were not significantly different in the recreational group. Functional questionnaire responses demonstrated significant improvements from the time of microfracture to final follow-up. Improvement in function and symptoms was similar for the competitive and recreational athletes.     

Sequential systemic platelet-activating factor and interleukin 8 primes neutrophils in patients with trauma at risk of multiple organ failure

Plasma from 33 patients at risk of multiple organ failure (MOF) after major trauma was tested for a priming effect on neutrophils, and for the presence of platelet-activating factor (PAF) activity and interleukin (IL) 8. Plasma sampled at 3, 6, 12 and 24 h after injury significantly primed normal neutrophils to release mean(s.e.m.) 1.26(0.19), 1.33(0.26), 1.04(0.14) and 0.86(0.13) nmol superoxide per min per 1.3 x 10(6) neutrophils respectively (P < 0.05). Priming at 3 h after injury was inhibited by mean(s.e.m.) 63.8(7.0) per cent by the PAF antagonist, WEB 2170 (P < 0.01). Mean(s.e.m.) plasma IL-8 was raised at 6 and 12 h after injury to 785(183) and 836(175) pg/ml (P < 0.01). At 12 h after injury the plasma IL-8 level correlated directly with the number of units of red blood cells transfused (r = 0.64, P < 0.01), and was significantly higher in the group of six patients who developed MOF (P < 0.05). These data suggest that after trauma the mediators PAF and IL-8 appear sequentially in the circulation, are potential mechanisms of circulating neutrophil priming, and that IL-8 may also be an early biochemical marker predicting the onset of MOF.     

Unsuspected varicella-zoster virus encephalitis in a child with acquired immunodeficiency syndrome

Novel techniques have made possible in situ analyses of the lymphocyte populations responding to antigen. In the spleen, antigen-specific T and B cells are first observed in the periarteriolar lymphoid sheath. Following conjugate formation between specific T and B lymphocytes, B-cell proliferation and differentiation takes place in two distinct sites, the periarteriolar lymphoid sheath-associated foci and germinal centers.     

The impact of age, marital status, and physician-patient interactions on the care of older women with breast carcinoma

Understanding why older women with breast carcinoma do not receive definitive treatment is critical if disparities in mortality between younger and older women are to be reduced. With this in mind, the authors studied 302 women age > or =55 years with early stage breast carcinoma. Data were collected from surgical records and in telephone interviews with the women. The main outcome was receipt of definitive primary tumor therapy, defined either as modified radical mastectomy or as breast-conserving surgery with axillary dissection followed by radiation therapy. The majority (56%) of the women underwent breast-conserving surgery and axillary dissection followed by radiation therapy. After statistical control for four variables (comorbidity, physical function, tumor size, and lymph node status), patients' ages, marital status, and the number of times breast carcinoma specialists discussed treatment options were significantly associated with the receipt of definitive primary tumor therapy. The authors concluded that when older women have been newly diagnosed with breast carcinoma and there is clinical uncertainty as to the most appropriate therapies, patients may be better served if they are offered choices from among definitive therapies. In discussing therapies with them, physicians must be sensitive to their fears and concerns about the monetary costs and functional consequences of treatment in relation to the expected benefits.