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11.
Mechanical Analysis of Atherosclerotic Plaques Based on Optical Coherence Tomography 总被引:8,自引:0,他引:8
Chau AH Chan RC Shishkov M MacNeill B Iftimia N Tearney GJ Kamm RD Bouma BE Kaazempur-Mofrad MR 《Annals of biomedical engineering》2004,32(11):1494-1503
Finite element analysis is a powerful tool for investigating the biomechanics of atherosclerosis and has thereby provided an improved understanding of acute myocardial infarction. Structural analysis of arterial walls is traditionally performed using geometry contours derived from histology. In this paper we demonstrate the first use of a new imaging technique, optical coherence tomography (OCT), as a basis for finite element analysis. There are two primary benefits of OCT relative to histology: 1) imaging is performed without excessive tissue handling, providing a more realistic geometry than histology and avoiding structural artifacts common to histologic processing, and 2) OCT imaging can be performed in vivo, making it possible to study disease progression and the effect of therapeutic treatments in animal models and living patients. Patterns of mechanical stress and strain distributions computed from finite element analysis based on OCT were compared with those from modeling based on "gold standard" histology. Our results indicate that vascular structure and composition determined by OCT provides an adequate basis for investigating the biomechanical factors relevant to atherosclerosis and acute myocardial infarction. 相似文献
12.
D. A. Hartman L. A. Tomchek J. R. Lugay A. C. Lewin T. T. Chau R. P. Carlson 《Inflammation research》1991,34(1-2):84-88
Melittin (MLT) (10 g/paw) and D49 (0.4 g/paw) were injected into the hind paw of male CD-1 mice and elicited 70–80% of maximal paw edema responses at 60 and 30 min after injection, respectively. D49 paw edema was significantly inhibited by anti-histamine/serotonin agents, a PAF antagonist, a PLA2 inhibitor, and some but not all 5-LO and CO inhibitors, indicating that this edema is produced by several classes of inflammatory mediators with mast cell degranulation apparently playing a major role. In contrast, MLT paw edema was not inhibited effectively using the same pharmacological agents except theophylline, suggesting it was elicited via a different sequence of inflammatory events. In summary, D49 and MLT paw edema models were found to be ineffective models to identify experimental PLA2 compounds in our laboratory. 相似文献
13.
14.
We have shown previously that in the acutely spinalized anesthetized rat the activities of many dorsal horn interneurons (DHN) at the T(10) level are correlated positively with both ongoing and stimulus-evoked renal sympathetic nerve activity (RSNA) and therefore may belong to networks generating RSNA after acute, cervical, spinal transection. In the present study, we recorded from both DHN and interneurons in the intermediate zone (IZN) of the T(10) spinal segment in acutely C(1)-transected, chloralose-anesthetized, artificially respired rats. The activities of a similar percentage of IZN and DHN were correlated positively with ongoing RSNA, but the peaks of spike-triggered averages of RSNA based on the activity of IZN were larger, relative to dummy averages, than spike-triggered averages of RSNA based on the activity of DHN. Sympathetically correlated DHN and IZN differed in their responses to noxious somatic stimuli. Most correlated DHN had relatively simple somatic fields; they were excited by noxious stimulation of the T(10) and nearby dermatomes and inhibited by stimulation of more distal dermatomes. As we have shown previously, the excitatory and inhibitory fields of these neurons were very similar to fields that, respectively, excited and inhibited RSNA. On the other hand, the somatic fields of 50% of sympathetically correlated IZN were significantly more complex, indicating a difference between either the inputs or the processing properties of IZN and DHN. Sympathetically correlated IZN and DHN also differed in their responses to colorectal distension (CRD), a noxious visceral stimulus. CRD increased RSNA in 11/15 rats and increased the activity of most sympathetically correlated T(10) IZN. On the other hand, CRD decreased the activity of a majority of sympathetically correlated T(10) DHN. These observations suggest that the same stimulus may differentially affect separate, putative, sympathoexcitatory pathways, exciting one and inhibiting the other. Thus the magnitude and even the polarity of responses to a given stimulus may be determined by the modality and location of the stimulus, the degree to which multiple pathways are affected by the stimulus, and the ongoing activity of presympathetic neurons, at multiple rostrocaudal levels, before stimulation. A multipathway system may explain the variability in autonomic responses to visceral and somatic stimuli exhibited in spinally injured patients. 相似文献
15.
Crossed immunoelectrophoretic analysis of anti-Salmonella typhi antibodies in sera of typhoid patients and carriers: demonstration of the presence of typhoid-specific antibodies to a non-O, non-H, non-Vi antigen
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A veronal buffer extract of Salmonella typhi was used as the reference antigen and its corresponding rabbit antiserum as the reference antibody in crossed immunoelectrophoresis to analyze antibodies in sera obtained from typhoid patients and carriers. Four precipitating antibodies were regularly detected. Three were against antigens common to other gram-negative bacteria and one appeared to be typhoid specific. Of the three common antigens, one (antigen no. 7) formed a precipitin resembling in mobility and morphology the lipopolysaccharide antigen seen in crossed immunoelectrophoresis analysis of other gram-negative bacteria. The other (antigen no. 19) was heat labile and antigenically similar to the reported common antigen of Pseudomonas aeruginosa. The third (antigen no. 14), also heat labile, was present in members of the family Enterobacteriaceae but not the family Pseudomonas. The typhoid-specific precipitating antibody present in sera of most typhoid patients and carriers but not patients infected with nontyphoid salmonella was directed to a heat-labile, non-O, non-H, and non-Vi antigen (antigen no. 28), probably protein in nature. 相似文献
16.
Solid-phase enzyme-linked immunosorbent assay for hepatitis E virus IgG and IgM antibodies utilizing recombinant antigens and synthetic peptides. 总被引:17,自引:0,他引:17
G J Dawson K H Chau C M Cabal P O Yarbough G R Reyes I K Mushahwar 《Journal of virological methods》1992,38(1):175-186
Four recombinant antigens representing two distinct antigenic domains from two different strains of hepatitis E virus (HEV), were used individually to develop four ELISAs designed to detect antibodies to HEV. Both IgG and IgM class antibodies to HEV were detected in 7 of 8 pedigreed serum/plasma from known outbreaks of HEV in Mexico, Burma, Somalia and Pakistan. In addition, specific HEV-antibodies were detected in cynomolgus macaques following inoculation with various HEV strains. Anti-HEV was also detected in 8 of 386 (2.1%) randomly selected American blood donors. Supplemental tests utilizing both synthetic peptides and specific blocking assays provided additional serologic data confirming the presence of anti-HEV. Similar prevalence studies on a limited number of available sera from other geographical regions (Alaska, Japan, Germany, New Zealand, Thailand and Mexico) confirmed the presence of anti-HEV in at least 1.1 to 7.6% of the specimens. 相似文献
17.
Chloe Miu Mak Ching-Wan Lam Sidney Tam Ching-Lung Lai Lik-Yuen Chan Sheung-Tat Fan Yu-Lung Lau Sik-To Lai Patrick Yuen Joannie Hui Chun-Cheung Fu Ka-Sing Wong Wing-Lai Mak Kong Tze Sui-Fan Tong Abby Lau Nancy Leung Aric Hui Ka-Ming Cheung Chun-Hung Ko Yiu-Ki Chan Oliver Ma Tai-Nin Chau Alexander Chiu Yan-Wo Chan 《Journal of human genetics》2008,53(4):375-375
18.
de Jong MD Bach VC Phan TQ Vo MH Tran TT Nguyen BH Beld M Le TP Truong HK Nguyen VV Tran TH Do QH Farrar J 《The New England journal of medicine》2005,352(7):686-691
In southern Vietnam, a four-year-old boy presented with severe diarrhea, followed by seizures, coma, and death. The cerebrospinal fluid contained 1 white cell per cubic millimeter, normal glucose levels, and increased levels of protein (0.81 g per liter). The diagnosis of avian influenza A (H5N1) was established by isolation of the virus from cerebrospinal fluid, fecal, throat, and serum specimens. The patient's nine-year-old sister had died from a similar syndrome two weeks earlier. In both siblings, the clinical diagnosis was acute encephalitis. Neither patient had respiratory symptoms at presentation. These cases suggest that the spectrum of influenza H5N1 is wider than previously thought. 相似文献
19.
Quality of Life Research - To summarize the current evidence regarding the effectiveness of intradialytic exercise (IDE) on the health-related quality of life (HRQOL) of patients undergoing... 相似文献
20.
ObjectivesNon-traditional materials are used for mask construction to address personal protective equipment shortages during the coronavirus disease 2019 (COVID-19) pandemic. Reusable masks made from surgical sterilization wrap represent such an innovative approach with social media frequently referring to them as “N95 alternatives.” This material was tested for particle filtration efficiency and breathability to clarify what role they might have in infection prevention and control.MethodsA heavyweight, double layer sterilization wrap was tested when new and after 2, 4, 6, and 10 autoclave sterilizing cycles and compared with an approved N95 respirator and a surgical mask via testing procedures using a sodium chloride aerosol for N95 efficiency testing similar to 42 CFR 84.181. Pressure testing to indicate breathability was also conducted.ResultsThe particle filtration efficiency for the sterilization wrap ranged between 58% to 66%, with similar performance when new and after sterilizing cycles. The N95 respirator and surgical mask performed at 95% and 68% respectively. Pressure drops for the sterilization wrap, N95 and surgical mask were 10.4 mmH2O, 5.9 mmH2O, and 5.1 mmH2O, respectively, well below the National Institute for Occupational Safety and Health limits of 35 mmH2O during initial inhalation and 25 mmH2O during initial exhalation.ConclusionsThe sterilization wrap’s particle filtration efficiency is much lower than a N95 respirator, but falls within the range of a surgical mask, with acceptable breathability. Performance testing of non-traditional mask materials is crucial to determine potential protection efficacy and for correcting misinterpretation propagated through popular media. 相似文献