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Pour-Ghaz I, Alkhatib D, Rhea I, Jefferies J, DeCarr K, Bihl A, Bond AJ, Sears C, Klinsky S, Hiatt N, Khouzam RN, Yedlapati N. Arrhythmogenic cardiomyopathy and left ventricular non-compaction: role of cardiac magnetic resonance in non-ischemic cardiomyopathy. Am J Med Sci 2023. [DOI: 10.1016/s0002-9629(23)00064-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Lam V, Hales R, Feliciano J, Voong K, Shin E, Smith K, Anagnostou V, Velculescu V, Thompson E, Sears C, Pardoll D, Rodavia H, Schneider H, Hu C, Amjad A, Guerrieri P, Jobe B, Zaidi A, Kelly R. 1497TiP REACTION – a phase Ib pilot study of nivolumab or nivolumab in combination with relatlimab after targeted radiation in patients with advanced esophagogastric cancer. Ann Oncol 2020. [DOI: 10.1016/j.annonc.2020.08.2003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Abstract
INTRODUCTION Across the US, vape shops have emerged to provide e-cigarette users access to products not usually available at gas stations or retail stores. As vape shop sales have steadily increased, so have questions about the impact of marketing and price on e-cigarette use behaviors. In this exploratory analysis, we aim to characterize spending on e-cigarettes and evaluate the association with customer perceptions and use behaviors. METHODS In a cross-sectional survey of vape shop customers (n=78), perceptions and use of e-cigarettes and tobacco products were assessed. Descriptive statistics and multivariate logistic regression were used to evaluate the association between spending and socioeconomic factors, demographics, and use behaviors. RESULTS Overall, spending amounts ranged from less than $10/month to more than $250/month, with a median around $50-75/month. Males spent more than females (p=0.003), but spending did not significantly differ by age (p=0.13). Customers who spent more than $50/month used lower levels of nicotine (mg/ml) (p=0.003) but a greater quantity of e-liquid (ml/month) (p<0.0001) compared to customers who spent under that amount. Mod use and intention to use e-cigarettes as a cessation device were significantly associated with vape shop spending in the regression model (OR= 17.5; 95% CI= (4.3, 70.2) and OR=0.22; 95% CI= (0.06, 0.75), respectively). CONCLUSIONS Spending appears to be significantly associated with e-cigarette use behaviors. Making "sense" of the potential relationships between the dollars spent at vape shops and consumer use behaviors is important as regulations for e-cigarette sales are proposed.
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Affiliation(s)
- C Sears
- University of Louisville, Kentucky, USA
| | - J Hart
- University of Louisville, Kentucky, USA
| | - K Walker
- University of Louisville, Kentucky, USA
| | - A Lee
- University of Louisville, Kentucky, USA
| | - R Keith
- University of Louisville, Kentucky, USA
| | - S Ridner
- University of Louisville, Kentucky, USA
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James D, Harville C, Efunbumi O, Stellefson M, Sears C. Strategies to Recruit African Americans into mHealth Weight Management Programs. J Acad Nutr Diet 2015. [DOI: 10.1016/j.jand.2015.06.254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Chen LA, Van Meerbeke S, Albesiano E, Goodwin A, Wu S, Yu H, Carroll K, Sears C. Fecal detection of enterotoxigenic Bacteroides fragilis. Eur J Clin Microbiol Infect Dis 2015; 34:1871-7. [PMID: 26173688 DOI: 10.1007/s10096-015-2425-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Accepted: 06/04/2015] [Indexed: 01/14/2023]
Abstract
Bacteroides fragilis is a common colonic symbiote of which one subtype, enterotoxigenic Bacteroides fragilis (ETBF), causes inflammatory diarrhea. However, asymptomatic ETBF colonization is common. Through its primary virulence factor, B. fragilis toxin (BFT), ETBF causes asymptomatic, chronic colitis in C57BL/6 mice and increased colon tumorigenesis in multiple intestinal neoplasia mice. Human studies suggest an association between ETBF infection, inflammatory bowel disease, and colon cancer. Additional studies on ETBF epidemiology are, therefore, crucial. The goal of this study is to develop a reliable fecal diagnostic for ETBF. To develop a sensitive assay for ETBF, we tested multiple protocols on mouse stools spiked with serially diluted ETBF. Each assay was based on either touchdown or quantitative polymerase chain reaction (qPCR) and used primers targeted to bft to detect ETBF. Using touchdown PCR or qPCR, the mean ETBF detection limit was 1.55 × 10(6) colony-forming units (CFU)/g stool and 1.33 × 10(4) CFU/g stool, respectively. Augmentation of Bacteroides spp. growth in fecal samples using PYGB (Peptone Yeast Glucose with Bile) broth enhanced ETBF detection to 2.93 × 10(2) CFU/g stool using the touchdown PCR method and 2.63 × 10(2) CFU/g stool using the qPCR method. Fecal testing using combined culture-based amplification and bft touchdown PCR is a sensitive assay for the detection of ETBF colonization and should be useful in studying the role of ETBF colonization in intestinal diseases, such as inflammatory bowel disease and colon cancer. We conclude that touchdown PCR with culture-based amplification may be the optimal ETBF detection strategy, as it performs as well as qPCR with culture-based amplification, but is a less expensive technique.
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Affiliation(s)
- L A Chen
- Department of Medicine, Johns Hopkins School of Medicine, CRB2 Bldg, Suite 1M.05, 1550 Orleans Street, Baltimore, MD, 21231, USA
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Sears C. Agnes Kirkland Conn. Assoc Med J 2013. [DOI: 10.1136/bmj.f7263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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7
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Hendrickson BC, Donohoe C, Akmaev VR, Sugarman EA, Labrousse P, Boguslavskiy L, Flynn K, Rohlfs EM, Walker A, Allitto B, Sears C, Scholl T. Differences in SMN1 allele frequencies among ethnic groups within North America. J Med Genet 2009; 46:641-4. [PMID: 19625283 PMCID: PMC2729371 DOI: 10.1136/jmg.2009.066969] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Background: Spinal muscular atrophy (SMA) is the most common inherited lethal disease of children. Various genetic deletions involving the bi-allelic loss of SMN1 exon 7 are reported to account for 94% of affected individuals. Published literature places the carrier frequency for SMN1 mutations between 1 in 25 and 1 in 50 in the general population. Although SMA is considered to be a pan-ethnic disease, carrier frequencies for many ethnicities, including most ethnic groups in North America, are unknown. Objectives and methods: To provide an accurate assessment of SMN1 mutation carrier frequencies in African American, Ashkenazi Jewish, Asian, Caucasian, and Hispanic populations, more than 1000 specimens in each ethnic group were tested using a clinically validated, quantitative real-time polymerase chain reaction (PCR) assay that measures exon 7 copy number. Results: The observed one-copy genotype frequency was 1 in 37 (2.7%) in Caucasian, 1 in 46 (2.2%) in Ashkenazi Jew, 1 in 56 (1.8%) in Asian, 1 in 91 (1.1%) in African American, and 1 in 125 (0.8%) in Hispanic specimens. Additionally, an unusually high frequency of alleles with multiple copies of SMN1 was identified in the African American group (27% compared to 3.3–8.1%). This latter finding has clinical implications for providing accurate adjusted genetic risk assessments to the African American population. Conclusions: Differences in the frequency of SMA carriers were significant among several ethnic groups. This study provides an accurate assessment of allele frequencies and estimates of adjusted genetic risk that were previously unavailable to clinicians and patients considering testing.
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Affiliation(s)
| | - C Donohoe
- Genzyme Genetics, Westborough, Massachusetts, USA
| | - V R Akmaev
- Genzyme Genetics, Westborough, Massachusetts, USA
| | - E A Sugarman
- Genzyme Genetics, Westborough, Massachusetts, USA
| | - P Labrousse
- Genzyme Genetics, Westborough, Massachusetts, USA
| | | | - K Flynn
- Genzyme Genetics, Westborough, Massachusetts, USA
| | - E M Rohlfs
- Genzyme Genetics, Westborough, Massachusetts, USA
| | - A Walker
- Genzyme Genetics, Westborough, Massachusetts, USA
| | - B Allitto
- Genzyme Genetics, Westborough, Massachusetts, USA
| | - C Sears
- Department of Hematology and Oncology, Children’s Hospital, Boston, Massachusetts, USA
- Broad Institute, Cancer Program, Cambridge, Massachusetts, USA
| | - T Scholl
- Genzyme Genetics, Westborough, Massachusetts, USA
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Guydish J, Manser ST, Jessup M, Tajima B, Sears C, Montini T. Multi-level assessment protocol (MAP) for adoption in multi-site clinical trials. J Drug Issues 2005; 35:529-546. [PMID: 20890376 PMCID: PMC2947142 DOI: 10.1177/002204260503500306] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The National Institute on Drug Abuse (NIDA) Clinical Trials Network (CTN) is intended to test promising drug abuse treatment models in multi-site clinical trials, and to support adoption of new interventions into clinical practice. Using qualitative research methods we asked: How might the technology of multi-site clinical trials be modified to better support adoption of tested interventions? A total of 42 participants, representing 8 organizational levels ranging from clinic staff to clinical trial leaders, were interviewed about their role in the clinical trial, its interactions with clinics, and intervention adoption. Among eight clinics participating in the clinical trial, we found adoption of the tested intervention in one clinic only. In analysis of interview data we identified four conceptual themes which are likely to affect adoption and may be informative in future multi-site clinical trials. We offer the conclusion that planning for adoption in the early stages of protocol development will better serve the aim of integrating new interventions into practice.
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Sears C, Guydish JR, Weltzien EK, Lum PJ. Investigation of a secondary syringe exchange program for homeless young adult injection drug users in San Francisco, California, U.S.A. J Acquir Immune Defic Syndr 2001; 27:193-201. [PMID: 11404542 DOI: 10.1097/00126334-200106010-00015] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
This study investigated an HIV prevention program for homeless young adult injection drug users (IDUs) that combined a secondary syringe exchange program (SEP) with community-level activities. Homeless young IDUs were recruited from street-based settings in San Francisco, and a structured questionnaire was administered. The secondary SEP operated in a circumscribed geographic area, and for analytic purposes respondents were assigned to the intervention site group if they primarily spent time in this area (n = 67), or the comparison site group if they primarily spent time elsewhere (n = 55). Almost all (96%) intervention site youth had used the secondary SEP in the past 30 days and were significantly more likely to regularly use SEP. In bivariate analysis, comparison site IDUs were more likely to share syringes, reuse syringes, share the cotton used to filter drugs, and use condoms with casual sex partners only inconsistently. In multivariate analysis, comparison site remained positively associated with sharing syringes (adjusted odds ratio [AOR], 3.748; 95% confidence interval [CI], 1.406-9.988), reusing syringes (AOR, 2.769; 95% CI,1.120-6.847), and inconsistent condom use with casual sex partners (AOR, 4.825; 95% CI, 1.392- 16.721). This suggests that the intervention was effective in delivering SEP services to homeless young adult IDUs, and that IDUs who frequented the intervention site had a lower HIV risk than comparison group IDUs.
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Affiliation(s)
- C Sears
- Department of Sociology, University of California-Santa Cruz, Santa Cruz, CA, USA
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10
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Navarro-García F, Canizalez-Roman A, Luna J, Sears C, Nataro JP. Plasmid-encoded toxin of enteroaggregative Escherichia coli is internalized by epithelial cells. Infect Immun 2001; 69:1053-60. [PMID: 11160002 PMCID: PMC97986 DOI: 10.1128/iai.69.2.1053-1060.2001] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2000] [Accepted: 10/07/2000] [Indexed: 11/20/2022] Open
Abstract
We have previously described a 104-kDa protein termed Pet (for plasmid-encoded toxin) secreted by some strains of enteroaggregative Escherichia coli (EAEC). Through an unknown mechanism, this toxin (i) raises transepithelial short-circuit current (Isc) and decreases the electrical resistance of rat jejunum mounted in the Ussing chamber, (ii) causes cytoskeletal alterations in HEp-2 cells and HT29/C1 cells, and (iii) is required for histopathologic effects of EAEC on human intestinal mucosa. Pet is a member of the autotransporter class of secreted proteins and together with Tsh, EspP, EspC, ShMu, and SepA proteins comprises the SPATE subfamily. Here, we show that Pet is internalized by HEp-2 cells and that internalization appears to be required for the induction of cytopathic effects. Evidence supporting Pet internalization includes the facts that (i) the effects of Pet on epithelial cells were inhibited by brefeldin A, which interferes with various steps of intracellular vesicular transport; (ii) immunoblots using anti-Pet antibodies detected Pet in the cytoplasmic fraction of intoxicated HEp-2 cells; (iii) Pet was detected inside HEp-2 cells by confocal microscopy; and (iv) a mutant in the passenger domain cleavage site, which prevents Pet release from the bacterial outer membrane, did not produce cytopathic effects on epithelial cells, whereas the release of mutant Pet from the outer membrane with trypsin yielded active toxin. We have also shown that the Pet serine protease motif is required to produce cytopathic effects but not for Pet secretion. Our results suggest an intracellular mode of action for the Pet protease and are consistent with we our recent report suggesting an intracellular mode of action for Pet.
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Affiliation(s)
- F Navarro-García
- Departments of Cell Biology, CINVESTAV-IPN, 07000 México, DF, Mexico.
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Abstract
This article reports on a process and capacity evaluation of San Francisco's Treatment on Demand Initiative, which was launched in 1997 to increase availability of publicly-funded substance abuse treatment. For the process evaluation, data from public documents, interviews with community key informants, and newspaper articles were analyzed. For the capacity evaluation, budget documents and admissions data for publicly-funded substance abuse treatment in San Francisco for fiscal years 1995-1998 were analyzed. Results from the process evaluation document the development of the community-oriented Treatment on Demand Planning Council, and its efforts to not only expand treatment, but to create a continuum of services to address the needs of San Francisco's richly diverse communities, to provide service enhancements, and to prioritize service needs. Process evaluation results also highlight the complexities of implementing treatment on demand, including the difficulty of opening new programs. Results from the capacity evaluation indicate that the San Francisco budget supporting publicly-funded treatment increased from $32 million to $45.2 million over four years. During the same period, the number of persons entering the system in a single year increased by 18%, and the number of admissions in a single year increased by 15%. Implications of these findings are discussed.
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Affiliation(s)
- J Guydish
- Institute for Health Policy Studies, University of California, San Francisco 94118, USA.
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12
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Navarro-García F, Sears C, Eslava C, Cravioto A, Nataro JP. Cytoskeletal effects induced by pet, the serine protease enterotoxin of enteroaggregative Escherichia coli. Infect Immun 1999; 67:2184-92. [PMID: 10225873 PMCID: PMC115956 DOI: 10.1128/iai.67.5.2184-2192.1999] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/1998] [Accepted: 02/11/1999] [Indexed: 11/20/2022] Open
Abstract
We have previously described enteroaggregative Escherichia coli (EAEC) strains that induce cytotoxic effects on T84 cells, ligated rat ileal loops, and human intestine in culture. Such strains secrete a 104-kDa protein termed Pet (for plasmid-encoded toxin). We have also shown previously that the Pet toxin induces rises in short-circuit current and decreases the electrical resistance in rat jejunum mounted in an Ussing chamber. The nucleotide sequence of the pet gene revealed that Pet is a member of the autotransporter class of secreted proteins. Here we show that a concentrated supernatant of E. coli HB101 harboring the minimal pet clone pCEFN1 induces temperature-, time- and dose-dependent cytopathic effects on HEp-2 cells and HT29 C1 cells in culture. The effects were characterized by release of the cellular focal contacts from the glass substratum, followed by complete rounding of the cells and detachment from the glass. Staining of the Pet-treated cells with Live/Dead viability stain revealed that >90% of rounded cells were viable. Pet-intoxicated HEp-2 and HT29 cells stained with fluorescein-labeled phalloidin revealed contraction of the cytoskeleton and loss of actin stress fibers. However, the effects of Pet were not inhibited by cytoskeleton-altering drugs, including colchicine, taxol, cytochalasin D, and phallicidin. The Pet protein induced proteolysis in zymogram gels, and preincubation with the serine protease inhibitor phenylmethylsulfonyl fluoride resulted in complete abrogation of Pet cytopathic effects. We introduced a mutation in a predicted catalytic serine residue and found that the mutant (Pet S260I) was deficient in protease activity and did not produce cytopathic effects, cytoskeletal damage, or enterotoxic effects in Ussing chambers. These data suggest that Pet is a cytoskeleton-altering toxin and that its protease activity is involved in each of the observed phenotypes.
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Affiliation(s)
- F Navarro-García
- Center for Vaccine Development, Department of Pediatrics, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA.
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Riegler M, Lotz M, Sears C, Pothoulakis C, Castagliuolo I, Wang CC, Sedivy R, Sogukoglu T, Cosentini E, Bischof G, Feil W, Teleky B, Hamilton G, LaMont JT, Wenzl E. Bacteroides fragilis toxin 2 damages human colonic mucosa in vitro. Gut 1999; 44:504-10. [PMID: 10075957 PMCID: PMC1727476 DOI: 10.1136/gut.44.4.504] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Strains of Bacteroides fragilis producing a 20 kDa protein toxin (B fragilis toxin (BFT) or fragilysin) are associated with diarrhoea in animals and humans. Although in vitro results indicate that BFT damages intestinal epithelial cells in culture, the effects of BFT on native human colon are not known. AIMS To examine the electrophysiological and morphological effects of purified BFT-2 on human colonic mucosa in vitro. METHODS For resistance (R) measurements, colonic mucosa mounted in Ussing chambers was exposed to luminal or serosal BFT-2 (1.25-10 nM) and after four hours morphological damage was measured on haematoxylin and eosin stained sections using morphometry. F actin distribution was assessed using confocal microscopy. RESULTS Serosal BFT-2 for four hours was four-, two-, seven-, and threefold more potent than luminal BFT-2 in decreasing resistance, increasing epithelial 3H-mannitol permeability, and damaging crypt and surface colonocytes, respectively (p<0.05). Confocal microscopy showed reduced colonocyte F actin staining intensity after exposure to BFT-2. CONCLUSIONS BFT-2 increases human colonic permeability and damages human colonic epithelial cells in vitro. These effects may be important in the development of diarrhoea and intestinal inflammation caused by B fragilis in vivo.
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Affiliation(s)
- M Riegler
- Division of Gastroenterology, Beth Israel Deaconess Medical Centre, Boston, Harvard Medical School, Massachusetts 02215, USA
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14
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Abstract
The p50 subunit of NF-kappa B is generated by proteolytic processing of a 105-kDa precursor (p105) in yeast and mammalian cells. Here we show that yeast mutants in the ubiquitin-proteasome pathway inhibit or abolish p105 processing. Specifically, p105 processing is inhibited by a mutation in a 20 S proteasome subunit (pre1-1), by mutations in the ATPases located in the 19 S regulatory complexes of the proteasome (yta1, yta2/sug1, yta5, cim5), and by a mutation in a proteasome-associated isopeptidase (doa4). A ubiquitinated intermediate of the p105 processing reaction accumulates in some of these mutants, strongly suggesting that ubiquitination is required for processing. However, none of the ubiquitin conjugating enzyme mutants tested (ubc1, -2, -3, -4/5, -6/7, -8, -9, -10, -11) had an effect on p105 processing, suggesting that more than one of these enzymes is sufficient for p105 processing. Interestingly, a mutant "N-end rule" ligase does not adversely affect p105 processing, showing that the N-end rule pathway is not involved in degrading the C-terminal region of p105. Unexpectedly, we found that a glycine-rich region of p105 that is required for p105 processing in mammalian cells is not required for processing in yeast. Thus, p105 processing in both yeast and mammalian cells requires the ubiquitin-proteasome pathway, but the mechanisms of processing, while similar, are not identical.
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Affiliation(s)
- C Sears
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA
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Qadri F, Mohi MG, Chowdhury A, Alam K, Azim T, Sears C, Sack RB, Albert MJ. Monoclonal antibodies to the enterotoxin of Bacteroides fragilis: production, characterization, and immunodiagnostic application. Clin Diagn Lab Immunol 1996; 3:608-10. [PMID: 8877146 PMCID: PMC170417 DOI: 10.1128/cdli.3.5.608-610.1996] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A monoclonal antibody, ICT11, specific for the toxin of enterotoxigenic Bacteroides fragilis (ETBF) neutralized the cytotoxic effect of the toxin on human colonic cell line HT-29/C1. In an evaluation using 115 diarrheal stool specimens and culture as the "gold standard," the assay showed a sensitivity of 85% and a specificity of 100%. An ICT11-based sandwich enzyme-linked immunosorbent assay showed a sensitivity of 100% and a specificity of 98% for direct detection of toxin from stool samples compared with those of culture. Thus, ICT11-based assays will be useful for screening for ETBF.
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Affiliation(s)
- F Qadri
- International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka
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Gilon D, Cape EG, Handschumacher MD, Jiang L, Sears C, Solheim J, Morris E, Strobel JT, Miller-Jones SM, Weyman AE, Levine RA. Insights from three-dimensional echocardiographic laser stereolithography. Effect of leaflet funnel geometry on the coefficient of orifice contraction, pressure loss, and the Gorlin formula in mitral stenosis. Circulation 1996; 94:452-9. [PMID: 8759088 DOI: 10.1161/01.cir.94.3.452] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND Three-dimensional echocardiography can allow us to address uniquely three-dimensional scientific questions, for example, the hypothesis that the impact of a stenotic valve depends not only on its limiting orifice area but also on its three-dimensional geometry proximal to the orifice. This can affect the coefficient of orifice contraction (Cc = effective/anatomic area), which is important because for a given flow rate and anatomic area, a lower Cc gives a higher velocity and pressure gradient, and Cc, routinely assumed constant in the Gorlin equation, may vary with valve shape (60% for a flat plate, 100% for a tube). To date, it has not been possible to study this with actual valve shapes in patients. METHODS AND RESULTS Three-dimensional echocardiography reconstructed valve geometries typical of the spectrum in patients with mitral stenosis: mobile doming, intermediate conical, and relatively flat immobile valves. Each geometry was constructed with orifice areas of 0.5, 1.0 and 1.5 cm2 by stereolithography (computerized laser polymerization) (total, nine valves) and studied at physiological flow rates. Cc varied prominently with shape and was larger for the longer, tapered dome (more gradual flow convergence proximal and distal to the limiting orifice): for an anatomic orifice of 1.5 cm2, Cc increased from 0.73 (flat) to 0.87 (dome), and for an area of 0.5 cm2, from 0.62 to 0.75. For each shape, Cc increased with increasing orifice size relative to the proximal funnel (more tubelike). These variations translated into important differences of up to 40% in pressure gradient for the same anatomic area and flow rate (greatest for the flattest valves), with a corresponding variation in calculated Gorlin area (an effective area) relative to anatomic values. CONCLUSIONS The coefficient of contraction and the related net pressure loss are importantly affected by the variations in leaflet geometry seen in patients with mitral stenosis. Three-dimensional echocardiography and stereolithography, with the use of actual information from patients, can address such uniquely three-dimensional questions to provide insight into the relations between cardiac structure, pressure, and flows.
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Affiliation(s)
- D Gilon
- Cardiac Ultrasound Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston 02114, USA
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Drossman DA, Brandt LJ, Sears C, Li Z, Nat J, Bozymski EM. A preliminary study of patients' concerns related to GI endoscopy. Am J Gastroenterol 1996; 91:287-91. [PMID: 8607494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVES In addition to the well known complications of bleeding and perforation, GI endoscopy also can produce discomfort, anxiety, and dissatisfaction. In this pilot study, our objective was to obtain information on the fears and concerns of patients about to undergo endoscopy and to assess the relationship of such worries to patient satisfaction and difficulty with the procedure. METHODS At our two referral hospitals, 793 unsedated patients (45% men, 55% women, average 58 yr) were interviewed by GI nurses before the intended procedure. Information on procedure-related concerns and difficulty/satisfaction with the procedure was obtained. RESULTS Sixty percent of our sample reported preprocedure concerns, most often: 1) finding out what is wrong (18%); 2) pain (12%); and 3) finding cancer (4%). New York patients were more concerned than North Carolina patients with finding out what was wrong (23 vs 12%) although patients at both sites were equally concerned about having pain during the procedure (12%); women (16%), younger patients (16%), and those about to have their first procedure (17%) reported more concerns about pain. Regression analysis indicated that women and persons having no or fewer procedures were more likely to report a concern. Having had previous endoscopic procedures predicted greater satisfaction with subsequent endoscopies. Finally, a high level of preprocedure concerns was associated with perceived difficulties related to the procedure. CONCLUSIONS We believe that, by considering patient demographics, asking about previous experiences with endoscopy, and eliciting special concerns, the nurse or physician can focus patient education in a fashion that may reduce anticipatory anxiety.
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Abstract
It is widely accepted that there exists a region or locus of maximal resource allocation in visual perception--sometimes referred to as the spotlight of attention. We have argued that even if there is a single locus of processing, there must be multiple loci of parallel access--several places in the visual field must be indexed at once and these indexes can be used to determine where attention is allocated. We have carried out a variety of studies to support these ideas, including experiments showing that subjects can track multiple independent moving targets in a field of identical distractors, that the enhanced ability to detect changes occurring on these targets does not accrue to nontargets nor to items lying inside the convex polygon that they form (so that a zoom-lens of attention does not fit the data). We have used a visual search paradigm to show that (serial or parallel) search can be confined to a subset of indexed items and the layout of these items is of little importance. We have also studied the phenomenon known as subitizing and have shown that subitizing occurs only when items can be preattentively individuated and in those cases location precuing has little effect, compared with when counting occurs, which suggests that subitizing may be carried out by counting active indexes rather than items in the visual field. And finally we have run studies showing that a certain motion effect that is sensitive to attention can occur at multiple precued loci. We believe that this evidence suggests that there is an early preattentive stage in vision where a small number of salient items in the visual field are indexed and thereby made readily accessible for a variety of visual tasks.
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Affiliation(s)
- Z Pylyshyn
- Department of Psychology, University of Western Ontario, London, Canada
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