On the mode of action ofClostridium difficile toxin A: anin vitro study

1991 ◽  
Vol 5 (S1) ◽  
pp. 84-85 ◽  
Author(s):  
C. Fiorentini ◽  
G. Donelli ◽  
P. Nicotera ◽  
P. Mastrantonio ◽  
M. Thelestam
Keyword(s):  
Mode Of Action ◽  
Vitro Study ◽  
Toxin A ◽  
Ofclostridium Difficile

Enhancement of cell-mediated cytotoxicity by Clostridium difficile toxin A: An in vitro study

Toxicon ◽  
1991 ◽  
Vol 29 (4-5) ◽  
pp. 417-428 ◽  
Author(s):  
W. Malorni ◽  
S. Paradisi ◽  
M.L. Dupuis ◽  
C. Fiorentini ◽  
C. Ramoni
Keyword(s):  
Clostridium Difficile ◽  
In Vitro Study ◽  
Vitro Study ◽  
Toxin A ◽  
Clostridium Difficile Toxin ◽  
Clostridium Difficile Toxin A

scholarly journals Effects of botulinum toxin A and papaverine on human saphenous vein and internal mammary artery grafts: an in vitro study

2021 ◽  
Author(s):  
Ipek Duman ◽  
Ömer Tanyeli ◽  
Yuksel Dereli ◽  
Pembe Oltulu ◽  
Hatice Toy ◽  
...  
Keyword(s):  
Botulinum Toxin ◽  
Saphenous Vein ◽  
Internal Mammary Artery ◽  
Botulinum Toxin A ◽  
In Vitro Study ◽  
Vitro Study ◽  
Arterial Graft ◽  
Toxin A ◽  
Internal Mammary

IntroductionAutologous saphenous vein (SV) and internal mammary artery (IMA) are used as bypass conduits during coronary artery bypass graft surgery. Vasospasm of the arterial and venous grafts may constitute a significant clinical problem. Pretreatment with a vasodilator drug of the graft ex vivo or intraluminal injection before implantation may be used for spasm prophylaxis. This in-vitro study was designed to assess the vasoactive effects and time-dependent changes of botulinum toxin A (BTX-A) and papaverine pretreatment on vasospasm of human SV and IMA grafts. Also histomorphology of the vessels were assessed.Material and methodsSV and IMA segments were suspended in organ baths and isometric contraction responses to two different concentrationsof 5-hydroxytryptamine (5-HT) and endothelin-1 (ET-1) were recorded after incubation with two different concentrations of BTX-A and papaverine at two time points (0 hours and 2nd hour).ResultsThe results suggest that; 1) incubation with BTX-A and papaverine relaxes both SV and IMA rings contracted with 5-HT and ET-1, 2) duration of the relaxant effect of BTX-A lasts longer than papaverine, 3) no apparent histomorphologic changes are observed in the grafts under light microscopy.ConclusionsThis study demonstrates that in human SV and IMA grafts, pretreatment with both BTX-A and papaverine are safe and have a potent inhibitory effect depending on the vessel and vasoconstrictor agent. Long lasting vasodilatory effect of BTX-A on vascular smooth muscle may provide promising results for preventing venous and arterial graft spasm.

scholarly journals Comparison of Culture, Cytotoxin Assay and Two Eia Tests with Clinical Diagnosis ofClostridium difficile-Associated Diarrhea

1994 ◽  
Vol 5 (4) ◽  
pp. 163-167 ◽  
Author(s):  
Marilyn Binning ◽  
Michael A John ◽  
Berend C Schieven ◽  
Thomas W Austin ◽  
Robert Lannigan ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Selective Medium ◽  
Infectious Diarrhea ◽  
Toxin A ◽  
Ofclostridium Difficile ◽  
Clinical Criteria ◽  
Hospital Patients ◽  
Common Etiology ◽  
Stool Specimens ◽  
Single Laboratory

Objective: The most common etiology of infectious diarrhea in hospitalized patients isClostridium difficile. No single laboratory test yields a definitive diagnosis. Four methods were evaluated for their sensitivity and specificity in patients who had clinically definedC difficile-associated diarrhea.Methods: Clinical criteria forC difficile-associated diarrhea were defined. All adult in-hospital patients whose stools were tested forC difficilewere prospectively followed. Stools were examined with culture on a selective medium, a commercial cytotoxicity assay (cta), and two commercially available enzyme immunoassays (eias) for toxin A (Meridian) and toxin AB (cbc).Results: During the study period 235 stool specimens from 185 patients were tested. Fifty-one patients were positive forC difficileor its markers,ctawas most sensitive (80%), whereascbc-eiawas most specific (98%). Differences in the sensitivities ofctaand Meridian-eiawere minor (80% versus 73.3%) and they were equally specific (95.5%).Conclusions: The sensitivity and specificity ofeiafor toxin A is similar to other tests. However, due to rapidity and ease of performance, it may be a more practical test for the diagnosis ofC difficile-associated diarrhea, especially if the cytotoxin assay is not available.

Cloning of the carbohydrate-binding portion of the toxin A gene ofClostridium difficile

1987 ◽  
Vol 16 (1) ◽  
pp. 55-60 ◽  
Author(s):  
Stuart B. Price ◽  
Carol J. Phelps ◽  
Tracy D. Wilkins ◽  
John L. Johnson
Keyword(s):  
Carbohydrate Binding ◽  
Toxin A ◽  
Ofclostridium Difficile

scholarly journals The effect of sinefungin on the macromolecular biosynthesis of Leishmania species

2018 ◽  
Vol 49 (2) ◽  
pp. 137
Author(s):  
A. TZORA (Α. ΤΖΩΡΑ) ◽  
F. LAWRENCE ◽  
M. ROBERT-GERO
Keyword(s):  
Dna Synthesis ◽  
Mode Of Action ◽  
Rna Synthesis ◽  
In Vitro Study ◽  
Leishmania Species ◽  
Sensitive Strain ◽  
Vitro Study ◽  
No Inhibition ◽  
Main Target

The aim of the work presented here was the in vitro study of the action of the antibiotic sinefungin on the macromolecules DNA, RNA and the proteins of different isolates of Leismannia spp. in relation to the resistance or to the sensitivity of the strains examined. The mode of action of sinefungin of the Leishmania strains was detected by incorporating radiolabeled thymidine, uridine and leucine into promastigote forms, to study the synthesis of DNA, RNA and proteins respectively. In the sensitive strain L. tropica a statistically significant reduction of the rate of incorporation of thymidine to the DNA of the parasite, resulted to a 64% inhibition of leishmanial DNA synthesis by sinefungin at a concentration of 2.6 mM, when the time of action of the drug was 24 hours. In the sensitive strain L. tropica the reduction of the rate of incorporation of thymidine was depended on the concentration and the time of action of the drug. No inhibition of leishmanial RNA synthesis was observed. Our research showed that the action of the antibiotic sinefungin to the macromolecular biosynthesis of the protozoan Leishmania is independent of the strain and is strongly related with the expression of the sensitivity and the resistance of the strain. The main target of the antibiotic examined was the DNA of the Leishmania strains sensitive to the drug.

scholarly journals Evaluation of Two Rapid Assays for Detection ofClostridium difficile Toxin A in Stool Specimens

1999 ◽  
Vol 37 (9) ◽  
pp. 3044-3047 ◽  
Author(s):  
Daniel P. Fedorko ◽  
Howard D. Engler ◽  
Elizabeth M. O’Shaughnessy ◽  
Esther C. Williams ◽  
Cynthia J. Reichelderfer ◽  
...  
Keyword(s):  
Predictive Value ◽  
Chart Review ◽  
Laboratory Diagnosis ◽  
Clinical Diagnostics ◽  
Becton Dickinson ◽  
Toxin A ◽  
Ofclostridium Difficile ◽  
Rapid Assays ◽  
Toxigenic Culture ◽  
Stool Specimens

Rapid laboratory diagnosis of Clostridium difficile-associated diarrhea (CDAD) is highly desirable in the setting of hospital cost containment. We tested 654 stool specimens to compare the performance of two assays for rapid detection of toxin A, the Immunocard Toxin A test (Meridian Diagnostics, Inc.) and the Culturette Brand Toxin CD enzyme immunoassay (EIA) (Becton Dickinson Microbiology Systems), with a cytotoxin assay (Cytotoxi Test; Advanced Clinical Diagnostics) and culture on cycloserine-cefoxitin-fructose agar followed by determination of the production of toxins A and B. A chart review was performed for patients whose stool specimens provided positive results on one to three of the assays. With the “gold standard” of all four assays positive or chart review evidence of CDAD, 97 (14.8%) stool specimens were positive by one or more assays and 557 (85.2%) were negative by all methods. Total agreement for all assays was 90.5% (592 of 654). The sensitivity, specificity, positive predictive value, and negative predictive value for toxigenic culture were 94.7, 98.6, 87.1, and 99.5%, respectively, for toxigenic culture; 87.7, 98.6, 86.2, and 98.8%, respectively, for the cytotoxin assay; 71.9, 99.3, 91.1, and 97.3%, respectively, for the Immunocard; and 68.4, 99.1, 88.6, and 96.9%, respectively, for the Culturette EIA. While easy to perform and highly specific, these rapid assays do not appear to be sufficient for accurate diagnosis of CDAD.

Lack of Association Between the Increased Incidence ofClostridium difficile–Associated Disease and the Increasing Use of Alcohol-Based Hand Rubs

2006 ◽  
Vol 27 (5) ◽  
pp. 479-483 ◽  
Author(s):  
John M. Boyce ◽  
Cathy Ligi ◽  
Cindy Kohan ◽  
Diane Dumigan ◽  
Nancy L. Havill
Keyword(s):  
Clostridium Difficile ◽  
Hand Hygiene ◽  
Teaching Hospital ◽  
Progressive Increase ◽  
Test Results ◽  
Toxin A ◽  
Ofclostridium Difficile ◽  
Community Teaching

Objective.To determine whether there is an association between the increasing use of alcohol-based hand rubs (ABHRs) and the increased incidence ofClostridium difficile–associated disease (CDAD).Setting.A 500-bed university-affiliated community teaching hospital.Methods.Use of ABHRs during the period 2000-2003 was expressed as the number of liters of ABHR used per 1000 patient-days. The proportion of hand hygiene episodes performed by using an ABHR was determined by periodic observational surveys. CDAD was defined as a physician-ordered stool assay positive forC. difficiletoxin A or A/B. The incidence of CDAD was expressed as the number of unique patients who had 1 or more positive CDAD test results per 1,000 patient-days.Results.During 2000-2003, the use of ABHR increased 10-fold, from 3 to greater than 30 L/1,000 patient-days (P< .001). The proportion of hand hygiene episodes performed using an ABHR increased from 10% to 85% (P< .001). The incidence of CDAD in 2000, 2001, 2002, and 2003 was 1.74, 2.33, 1.14, and 1.18 cases/1,000 patient-days, respectively.Conclusion.Despite a significant and progressive increase in the use of ABHRs in our facility during a 3-year period, there was no evidence that the incidence of CDAD increased. These findings suggest that factors other than the increased use of ABHRs are responsible for the increasing incidence of CDAD noted since 2000 in other facilities.

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