Providing feedback in research with human subjects.

Feedback provided to Ss and 3rd parties from intra- and extramural investigators following the completion of research involving an agency's clients or staff is described. Ss were from the division of a public health department that provides mental health and substance abuse services in a city with 740,000 people. The division's research requirements include submission of annual progress reports and final reports. Of 135 studies conducted over 12 yrs, annual reports were received from 37% of investigators, and final reports from 30%. There were no significant differences based on investigator discipline or affiliation. Professional and ethical implications are discussed, including adequacy of professional training, the need for mechanisms to ensure compliance with ethical standards, the obligations of clinic directors, and the impact on public academic liaison programs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Anaphylaxis in Association with Heparin-Induced Thrombocytopenia

Heparin is almost universally used as an anticoagulant during hemodialysis. Rare but serious side effects of heparin therapy include heparin‐induced thrombocytopenia (HIT) and anaphylaxis, and these may lead to significant mortality and morbidity if left unrecognized. We are reporting a patient who developed HIT followed by an anaphylactoid reaction. This 8‐year‐old girl with Joubert's syndrome developed end‐stage renal disease secondary to nephronophthisis. She had a Permacath double‐lumen hemodialysis catheter placed in the right internal jugular vein and was started on hemodialysis using an Asahi B10 65 Dialyzer on 1/28/03. The platelet count at that time was 246 × 10³/mL. Beef lung heparin was used for anticoagulation. She was admitted for living related donor renal transplant on 2/10/03 but was found to be thrombocytopenic with a platelet count of 49 × 10³/mL. The transplant was postponed, a sepsis work‐up was performed, and she was started on antibiotics pending culture results. Hemodialysis was continued with heparin anticoagulation, and despite an improvement in the platelet count she had an acute anaphylactoid reaction 2 days later. The reaction occurred 20 min after starting her hemodialysis treatment and presented as acute onset of bronchospasm, agitation, and chest discomfort. She improved with nebulized albuterol and subcutaneous epinephrine. A review of her records revealed that she had received 6 hemodialysis treatments. The platelet count on 2/3/03, after 3 hemodialysis treatments, had been 242 × 10³/mL and on 2/8/03 after 5 treatments the platelet count was 72 × 10³/mL. HIT with anaphylaxis was suspected. Heparin was discontinued and the platelet count had returned to normal within 2 days. The diagnosis was confirmed by a positive heparin‐associated antibody test. While HIT is recognized as a complication in 1–5% of patients treated with heparin and has been well described in the literature, we could only find 2 reported cases of heparin‐induced anaphylaxis and in both cases there was accompanying thrombocytopenia. This patient further illustrates a possible linkage between these two phenomena. HIT is an important cause of thrombocytopenia in a patient on hemodialysis and continued exposure to heparin may induce anaphylaxis.     

Rheological and mechanical performance of ethyl‐vinyl acetate/poly(vinyl chloride) formulations

A range of powdered ethyl‐vinyl acetate (EVA) copolymers and poly(vinyl chloride) (PVC) formulations were compounded at PVC:EVA ratios of 100:0, 60:40, 50:50, 40:60, and 0:100. Two grades of EVA with 20% and 27% of vinyl acetate (VAc) (EVA I and EVA II) and two grades of PVC with K values of 56 and 71 (PVC I and PVC II) were used in the investigation. Mechanical analysis was performed on injection molded samples of these blends, and the results showed that the tensile and flexural moduli decreased significantly with increasing EVA concentration. Rheological analysis was performed by using dual capillary rheometry, and the results showed only slight changes in shear viscosity with increasing EVA content, even at lower shear rates. Dynamic mechanical thermal analysis showed partial miscib lity of the PVC and EVA over the range of concentrations studied.     

Analyses of lipids and oxidation products by partition chromatography: Hydroxy fatty acids and esters

A liquid-partition chromatographic procedure was used to separate hydroxy fatty acids, their methyl esters, and reduced fatty ester hydroperoxides. Mixtures of methyl stearate, mono- and dihydroxystearate, and mixtures of the corresponding free fatty acids were easily separated. Chromatographic determinations for ricinoleate in castor oils compared favorably with the chemical and infrared analyses. The chromatographic procedure was used to separate hydroxy fatty acids inDimorphotheca andStrophanthus seed oils. The methyl ester of dimorphecolic acid, the principal hydroxy fatty ester ofDimorphotheca oil, behaved like reduced methyl linoleate hydroperoxide and showed a polarity intermediate between methyl 12-hydroxystearate and methyl 9,10-dihydroxystearate. The 9-hydroxy-12-octadecenoic ester ofStrophanthus oil had a larger retention volume than methyl ous hydroxy fatty esters isolated chromatographically. The diene content of the reduced hydroperoxides agrees well with values reported in the literature (1,5,16). The diene content of the chromatographed methyl dimorphecolate is higher than reported by Smithet al. (20) for their preparations but agrees well with the value reported by Chipault and Hawkins (6) for puretrans-trans conjugated methyl linoleate. The extinction coefficient of methyl 12-hydroxystearate at 2.8 μ is higher than that reported for ricinoleate and the absorption band is much sharper. Because of these two conditions no association of the hydroxyl groups is indicated. These results also confirm the purity of the hydroxy fatty esters obtained by LPC. This method has been a valuable adjunct to the study of various oxygen-containing fatty acid and esters and was used to characterize the hydroxy esters obtained from the hydrogenation of methyl linolenate hydroperoxides (9). This work offers a basis for the development of analytical methods to determine the hydroxy and other polar acid content of fatty glycerides and their derivatives.     

Linear-Time Recognition of Helly Circular-Arc Models and Graphs

A circular-arc model ℳ is a circle C together with a collection A\mathcal{A} of arcs of C. If A\mathcal{A} satisfies the Helly Property then ℳ is a Helly circular-arc model. A (Helly) circular-arc graph is the intersection graph of a (Helly) circular-arc model. Circular-arc graphs and their subclasses have been the object of a great deal of attention in the literature. Linear-time recognition algorithms have been described both for the general class and for some of its subclasses. However, for Helly circular-arc graphs, the best recognition algorithm is that by Gavril, whose complexity is O(n ³). In this article, we describe different characterizations for Helly circular-arc graphs, including a characterization by forbidden induced subgraphs for the class. The characterizations lead to a linear-time recognition algorithm for recognizing graphs of this class. The algorithm also produces certificates for a negative answer, by exhibiting a forbidden subgraph of it, within this same bound.     

Thermal conductivity of doped polysilicon layers

The thermal conductivities of doped polysilicon layers depend on grain size and on the concentration and type of dopant atoms. Previous studies showed that layer processing conditions strongly influence the thermal conductivity, but the effects of grain size and dopant concentration were not investigated in detail. The current study provides thermal conductivity measurements for low-pressure chemical-vapor deposition (LPCVD) polysilicon layers of thickness near 1 μm doped with boron and phosphorus at concentrations between 2.0×10¹⁸ cm^-3 and 4.1×10¹⁹ cm^-3 for temperatures from 20 K to 320 K. The data show strongly reduced thermal conductivity values at all temperatures compared to similarly doped single-crystal silicon layers, which indicates that grain boundary scattering dominates the thermal resistance. A thermal conductivity model based on the Boltzmann transport equation reveals that phonon transmission through the grains is high, which accounts for the large phonon mean free paths at low temperatures. Algebraic expressions relating thermal conductivity to grain size and dopant concentration are provided for room temperature. The present results are important for the design of MEMS devices in which heat transfer in polysilicon is important     

FRET measurements on fuzzy fluorescent nanostructures

In the last decade, fluorescence resonance energy transfer (FRET) has become a useful technique for studying intermolecular interactions applied to the analysis of biological systems. Although FRET measurements may be very helpful in the comprehension of different cellular processes, it can be difficult to obtain quantitative results, hence the necessity of studying FRET on controllable systems. Here, a fuzzy nanostructured system called a nanocapsule is presented as a nanometric-device allowing distance modulation, thus preserving photophysical properties of fluorescent dyes and exhibiting good potential features for improving quantitative FRET analysis. We evaluated the behavior of such a sample using four FRET methods (three of them based on steady-state fluorescence and one using lifetime measurements). Within some limitations that can be overcome, these nanodevices have the potential to serve as a benchmark system for characterizing new FRET couples and to develop quantitative approaches for FRET analysis.     

Glutathione-S-transferase M1 regulation of diesel exhaust particle-induced pro-inflammatory mediator expression in normal human bronchial epithelial cells

ABSTRACT: BACKGROUND: Diesel exhaust particles (DEP) contribute substantially to ambient particulate matter (PM) air pollution in urban areas. Inhalation of PM has been associated with increased incidence of lung disease in susceptible populations. We have demonstrated that the glutathione Stransferase M1 (GSTM1) null genotype could aggravate DEP-induced airway inflammation in human subjects. Given the critical role airway epithelial cells play in the pathogenesis of airway inflammation, we established the GSTM1 deficiency condition in primary bronchial epithelial cells from human volunteers with GSTM1 sufficient genotype (GSTM1+) using GSTM1 shRNA to determine whether GSTM1 deficiency could exaggerate DEP-induced expression of interleukin-8 (IL-8) and IL-1beta proteins. Furthermore, the mechanisms underlying GSTM1 regulation of DEP-induced IL-8 and IL-1beta expression were also investigated. METHODS: IL-8 and IL-1beta protein levels were measured using enzyme-linked immunosorbent assay. GSTM1 deficiency in primary human bronchial epithelial cells was achieved using lentiviral GSTM1 shRNA particles and verified using real-time polymerase chain reaction and immunoblotting. Intracellular reactive oxygen species (ROS) production was evaluated using flow cytometry. Phosphorylation of protein kinases was detected using immunoblotting. RESULTS: Exposure of primary human bronchial epithelial cells (GSTM1+) to 25-100 mug/ml DEP for 24 h significantly increased IL-8 and IL-1beta protein expression. Knockdown of GSTM1 in these cells further elevated DEP-induced IL-8 and IL-1beta expression, implying that GSTM1 deficiency aggravated DEP-induced pro-inflammatory response. DEP stimulation induced the phosphorylation of extracellular signal-regulated kinase (ERK) and Akt, the downstream kinase of phosphoinositide 3-kinase (PI3K), in GSTM1+ bronchial epithelial cells. Pharmacological inhibition of ERK kinase and PI3K activity blocked DEP-induced IL-8 and IL-1beta expression. DEP-induced ERK and Akt phosphorylation could be increased by GSTM1 knockdown. In addition, pretreatment of HBEC with the antioxidant N-acetyl cysteine significantly inhibited DEP-induced ERK and Akt phosphorylation, and subsequent IL-8 and IL-beta expression. CONCLUSION: GSTM1 regulates DEP-induced IL-8 and IL-1beta expression in primary human bronchial epithelial cells by modulation of ROS, ERK and Akt signaling.