Enzymatic removal of ADP from plasma: unaltered platelet adhesion but reduced aggregation on subendothelium and collagen fibrils

Subendothelium of rabbit aorta and fibrillar collagen were exposed to citrated human or rabbit blood which was circulated through a perfusion chamber under flow conditions similar to those found in arteries. The resulting platelet adhesion and subsequent formation of platelet microthrombi on the exposed surfaces were measured in 0.8 mum thich sections by a morphometric technique using light microscopy. Removal of plasma ADP by the substrate-enzyme combination CP-CPK (creatine phosphate-creatine phosphokinase; 3 mM and 90 U/ml blood) did not affect the initial attachment and spreading of platelets on subendothelium, whereas platelet thrombus formation was strongly inhibited. On free collagen fibrils CP-CPK was much less inhibitory on platelet thrombus formation but platelet adhesion again was not affected. It is concluded that platelet aggregation induced by thrombogenic surfaces in the presence of arterial blood flow is at least partially governed by ADP released from adhering platelets. Platelet adhesion to the examined surfaces, however, does not seem to be mediated by plasma ADP.     

Identification of the swine pathogen Serpulina hyodysenteriae in rheas (Rhea americana)

Recently intestinal spirochetes were isolated from rheas in Ohio and Iowa with a necrotizing typhlocolitis. These intestinal spirochetes, strains R1 and NIV-1, were characterized and compared with other intestinal spirochetes, including strains of S. hyodysenteriae. Both rhea spirochetes were indole positive, strongly beta-hemolytic, grew under a 1% O2:99% N2 atmosphere, and were morphologically similar to spirochetes in the genus Serpulina. Analysis of rRNA gene restriction patterns (ribotypes), and immunoblots of whole cell proteins, indicated both spirochetes were similar to Serpulina hyodysenteriae strains from swine. Comparisons of nearly complete sequences (> 1458 bases) of the 16S rRNA gene of the two rhea spirochetes with S. hyodysenteriae strains confirmed that rhea spirochetes R1 and NIV-1 were strains of S. hyodysenteriae. These results indicate that S. hyodysenteriae has a broader host range than previously recognized.     

An immune complex selective affinity column utilizing site-specific attachment of bovine conglutinin

Established leukemic cell lines have been useful models for studying the biology of leukemia. Analysis of the actions of differentiating agents on leukemic cell lines in vivo has been limited by an inability to unambiguously distinguish host hematopoietic elements from differentiated leukemic cells. In order to identify and quantify leukemic cells during in vivo studies, a derivative of the murine myelomonocytic leukemia cell line WEHI-3B D+, which stably expresses beta-galactosidase, was constructed utilizing retroviral vector gene transfer. This cell line, termed WEHI-3B D+/lacZ 2.8, demonstrated in vitro growth and differentiation properties similar to the parental cell line. WEHI-3B D+/lacZ 2.8 expressed high levels of beta-galactosidase following prolonged in vitro growth and following differentiation in suspension cultures and clonogenic assays. In vivo, WEHI-3B D+/lacZ 2.8 was leukemogenic and high level expression of beta-galactosidase was maintained. Quantification of tissue involvement with WEHI-3B D+/lacZ 2.8 leukemia was performed utilizing staining with the fluorogenic beta-galactosidase substrate fluorescein di-beta-galactoside and fluorescence-activated cell sorting analysis. In vivo differentiation efficiency following granulocyte colony-stimulating factor (G-CSF) administration was determined using a simultaneous nuclear and cytoplasmic staining procedure. Results indicate that treatment of mice inoculated with WEHI-3B D+/lacZ 2.8 cells with G-CSF administration causes detectable but limited differentiation.     

Commercial aircraft engine emissions characterization of in-use aircraft at Hartsfield-Jackson Atlanta International Airport

The emissions from in-use commercial aircraft engines have been analyzed for selected gas-phase species and particulate characteristics using continuous extractive sampling 1-2 min downwind from operational taxi- and runways at Hartsfield-Jackson Atlanta International Airport. Using the aircraft tail numbers, 376 plumes were associated with specific engine models. In general, for takeoff plumes, the measured NOx emission index is lower (approximately 18%) than that predicted by engine certification data corrected for ambient conditions. These results are an in-service observation of the practice of "reduced thrust takeoff". The CO emission index observed in ground idle plumes was greater (up to 100%) than predicted by engine certification data for the 7% thrust condition. Significant differences are observed in the emissions of black carbon and particle number among different engine models/technologies. The presence of a mode at approximately 65 nm (mobility diameter) associated with takeoff plumes and a smaller mode at approximately 25 nm associated with idle plumes has been observed. An anticorrelation between particle mass loading and particle number concentration is observed.     

The electrophysiological effects of tetraphenylphosphonium on vascular smooth muscle

OBJECTIVE: To investigate whether luteal secretion of inhibin-a is altered in the perimenopausal transition and to evaluate whether luteal inhibin secretion is correlated with other markers of ovarian reserve such as FSH and inhibin-b. DESIGN: Prospective study. SETTING: Reproductive Endocrinology Laboratories at The Ohio State University. PATIENT(S): Twenty-five women 39-52 years of age with regular menstrual cycles. INTERVENTION(S): Daily urine samples were monitored (LH predictor kit) to identify the day of ovulation. Blood samples obtained on days 6 and 8 after the LH surge and on day 3 of the subsequent follicular phase were assayed for FSH, E2, progesterone. inhibin-a, and inhibin-b. MAIN OUTCOME MEASURE(S): Serum levels of inhibin-a, inhibin-b, FSH, E2, and progesterone. RESULT(S): Luteal phase inhibin-a and follicular phase inhibin-b were correlated inversely with age in perimenopausal women. In addition, luteal phase inhibin-a and follicular phase inhibin-b levels were correlated inversely with follicular phase FSH levels. CONCLUSION(S): Both luteal phase inhibin-a and follicular phase inhibin-b levels are correlated inversely with age during the fifth decade of life. These findings suggest that corpus luteum function is altered during the perimenopausal transition. Moreover, these direct measures of ovarian function may be more sensitive indicators of "ovarian reserve" than indirect indicators such as pituitary FSH secretion.     

Airborne and laboratory studies of an IAGOS instrumentation package containing a modified CAPS particle extinction monitor

An evaluation of the operation and performance of a Cavity Attenuated Phase-Shift Particle Extinction Monitor (CAPS PM_ex) was performed for use on board commercial aircraft as part of the research infrastructure IAGOS (In-service Aircraft for a Global Observing System, www.iagos.org). After extensive laboratory testing, a new flow system, using mass flow controllers, was installed to maintain constant purge and sample flows under low and varying pressure conditions. The instrument was then tested for pressures as low as 200 hPa and evaluated against particle-free compressed air and CO₂. Extinction coefficients for the studied gases were in close agreement with literature values with differences between 2.2% and 8%, proving that the CAPS technology works at low pressures. The instrument's limit of detection, with respect to 3 times the variability of the background signal for the full pressure range, was 0.2 Mm^?1 for 60s integration time. During its first research aircraft operations, the IAGOS instrument prototype, composed of one CAPS PMex and one OPC, showed excellent results regarding the stability of the instruments and the potential for characterizing different aerosol types and for estimating the contribution of sub- and super-μm sized particles to aerosol light extinction.

Copyright © 2017 American Association for Aerosol Research     

Comparison of three different methods for measuring classical pathway complement activity

A 30-year-old man was referred as an acute case for keratitis. Two days earlier he had had photorefractive keratectomy for myopia at another clinic; a bandage contact lens was placed over the eye, but prophylactic antibiotics were not prescribed. The keratitis was treated with gentamicin sulfate (Garamycin) and chloramphenicol eyedrops. Scrapings from the cornea showed nonhemolytic streptococci. Two and a half months later, visual acuity was finger counting because of gross distortion of the corneal contour. The combination of a bandage contact lens and the lack of prophylactic antibiotics may have been the source of bacterial keratitis.     

大型水轮发电机组轴系临界转速模拟试验研究

针对大型水轮发电机组轴系临界转速难以实际测定的现实问题,从理论分析的角度出发,抓住水力机组轴系结构的基本特点,提出采用较为简单的模拟结构,试验研究水力机组轴系固有频率及其振型特征。初步研究结果已在理论分析和实际机组中得到验证。