scholarly journals High Prevalence Of Antibody Response Against Plasmodium Falciparum (Pf) Antigens In A Holoendemic Area Of Benin (1994-1995)

2017 ◽  
Vol 13 (3) ◽  
pp. 306
Author(s):  
S. Judith Gbenoudon Satoguina ◽  
Clemens H. Cocken ◽  
Alan W. Thomas ◽  
Jean Langhorne ◽  
Ambaliou Sanni

The present study aimed at measuring the capacity of naturally occurring antibodies to bind Pf83/AMA-1 and MSP-1/19 antigens, two malaria vaccine candidates, in an immunoassay. According to the fact that antibody prevalence reflects endemicity of malaria, we further aimed at using the results obtained here as baseline data set to follow up and evaluate the expected decline in endemicity in 2016, 8 years after the change in drug policy in Benin. Therefore, individuals, 2 – 19 and above 20 years old, living in Awansori, a malaria holoendemic area in the suburb of Cotonou, Benin were bled during the dry and raining seasons of the years 1994/1995. Antibody responses were measured using direct, indirect and competition ELISA. We found a very high prevalence of antibody responses (89 to 96%) in the studied population. The results indicate for Pf83/AMA-1, that naturally occurring antibodies bind to protective epitopes in a competition ELISA with a parasite inhibiting monoclonal antibody. The data and samples analysed here were collected during the rainy season 1994 and the following dry season 1994/1995.

2007 ◽  
Vol 75 (5) ◽  
pp. 2493-2499 ◽  
Author(s):  
Tatiane A. Paixão ◽  
Fernando P. Poester ◽  
Alcina V. Carvalho Neta ◽  
Álan M. Borges ◽  
Andrey P. Lage ◽  
...  

ABSTRACT The NRAMP1 gene encodes a divalent cation transporter, located in the phagolysosomal membrane of macrophages, that has been associated with resistance to intracellular pathogens. In cattle, natural resistance against brucellosis has been associated with polymorphisms at the 3′ untranslated region (3′UTR) of the NRAMP1 gene, which are detectable by single-strand conformational analysis (SSCA). This study aimed to evaluate the association between NRAMP1 3′UTR polymorphisms and resistance against bovine brucellosis in experimental and natural infections. In experimentally infected pregnant cows, abortion occurred in 42.1% of cows with a resistant genotype (SSCAr; n = 19) and in 43.1% of those with a susceptible genotype (SSCAs; n = 23). Furthermore, no association between intensity of pathological changes and genotype was detected. In a farm with a very high prevalence of bovine brucellosis, the percentages of strains of the SSCAr genotype were 86 and 84% in serologically positive (n = 64) and negative (n = 36) cows, respectively. Therefore, no association was found between the NRAMP1-resistant allele and the resistant phenotype in either experimental or naturally occurring brucellosis. To further support these results, bacterial intracellular survival was assessed in bovine monocyte-derived macrophages from cattle with either the resistant or susceptible genotype. In agreement with our previous results, no difference was observed in the rates of intracellular survival of B. abortus within macrophages from cattle with susceptible or resistant genotypes. Taken together, these results indicate that these polymorphisms at the NRAMP1 3′UTR do not affect resistance against B. abortus in cattle and that they are therefore not suitable markers of natural resistance against bovine brucellosis.


2017 ◽  
Vol 80 (11) ◽  
pp. 1913-1923 ◽  
Author(s):  
Susan R. Hammons ◽  
Andrea J. Etter ◽  
Jingjin Wang ◽  
Tongyu Wu ◽  
Thomas Ford ◽  
...  

ABSTRACT The objective of this study was to develop and assess the efficacy of an aggressive deep cleaning sanitation standard operating procedure (DC-SSOP) in nine retail delicatessens to reduce persistent Listeria monocytogenes environmental contamination. The DC-SSOP was developed from combined daily SSOPs recommended by the Food Marketing Institute and input from experts in Listeria control from food manufacturing and sanitation. The DC-SSOP was executed by a trained professional cleaning service during a single 12-h shutdown period. A modified protocol from the U.S. Food and Drug Administration Bacteriological Analytical Manual was used to detect L. monocytogenes in samples from 28 food and nonfood contact surfaces that were collected immediately before and after each cleaning and in samples collected monthly for 3 months. The DC-SSOP significantly reduced L. monocytogenes prevalence overall during the 3-month follow-up period and produced variable results for persistent L. monocytogenes isolates. Six delis with historically low to moderate L. monocytogenes prevalence had no significant changes in the number of samples positive for L. monocytogenes after deep cleaning. Deep cleaning in very high prevalence delis (20 to 30% prevalence) reduced L. monocytogenes by 25.6% (Padj < 0.0001, n = 294) overall during the follow-up period. Among delis with extremely high prevalence (>30%), positive samples from nonfood contact surfaces were reduced by 19.6% (Padj = 0.0002, n = 294) during the follow-up period. The inability of deep cleaning to completely eliminate persistent L. monocytogenes was likely due to the diverse infrastructures in each deli, which may require more individualized intervention strategies.


2021 ◽  
Vol 503 (3) ◽  
pp. 4092-4104
Author(s):  
Matthew P Battley ◽  
Michelle Kunimoto ◽  
David J Armstrong ◽  
Don Pollacco

ABSTRACTUp to date planet ephemerides are becoming increasingly important as exoplanet science moves from detecting exoplanets to characterizing their architectures and atmospheres in depth. In this work, ephemerides are updated for 22 Kepler planets and 4 Kepler planet candidates, constituting all Kepler planets and candidates with sufficient signal to noise in the TESS 2 min data set. A purely photometric method is utilized here to allow ephemeris updates for planets even when they do not posses significant radial velocity data. The obtained ephemerides are of very high precision and at least seven years ‘fresher’ than archival ephemerides. In particular, significantly reduced period uncertainties for Kepler-411d, Kepler-538b, and the candidates K00075.01/K00076.01 are reported. O–C diagrams were generated for all objects, with the most interesting ones discussed here. Updated TTV fits of five known multiplanet systems with significant TTVs were also attempted (Kepler-18, Kepler-25, Kepler-51, Kepler-89, and Kepler-396), however these suffered from the comparative scarcity and dimness of these systems in TESS. Despite these difficulties, TESS has once again shown itself to be an incredibly powerful follow-up instrument as well as a planet-finder in its own right. Extension of the methods used in this paper to the 30 min-cadence TESS data and TESS extended mission has the potential to yield updated ephemerides of hundreds more systems in the future.


Author(s):  
Shamez N Ladhani ◽  
Anna J Jeffery-Smith ◽  
Monika Patel ◽  
Roshni Janarthanan ◽  
Jonathan Fok ◽  
...  

Background: We investigated six London care homes experiencing a COVID-19 outbreak and found very high rates of SARS-CoV-2 infection among residents and staff. Here we report follow-up serological analysis in these care homes five weeks later. Methods: Residents and staff had a convalescent blood sample for SARS-CoV-2 antibody levels and neutralising antibodies by SARS-COV-2 RT-PCR five weeks after the primary COVID-19 outbreak investigation. Results: Of the 518 residents and staff in the initial investigation, 208/241 (86.3%) surviving residents and 186/254 (73.2%) staff underwent serological testing. Almost all SARS-CoV-2 RT-PCR positive residents and staff were antibody positive five weeks later, whether symptomatic (residents 35/35, 100%; staff, 22/22, 100%) or asymptomatic (residents 32/33, 97.0%; staff 21/22, 95.1%). Symptomatic but SARS-CoV-2 RT-PCR negative residents and staff also had high seropositivity rates (residents 23/27, 85.2%; staff 18/21, 85.7%), as did asymptomatic RT-PCR negative individuals (residents 62/92, 67.3%; staff 95/143, 66.4%). Neutralising antibody was present in 118/132 (89.4%) seropositive individuals and was not associated with age or symptoms. Ten residents (10/108, 9.3%) remained RT-PCR positive, but with lower RT-PCR cycle threshold values; all 7 tested were seropositive. New infections were detected in three residents and one staff member. Conclusions: RT-PCR testing for SARS-CoV-2 significantly underestimates the true extent of an outbreak in institutional settings. Elderly frail residents and younger healthier staff were equally able to mount robust and neutralizing antibody responses to SARS-CoV-2. More than two-thirds of residents and staff members had detectable antibodies against SARS-CoV-2 irrespective of their nasal swab RT-PCR positivity or symptoms status.


2017 ◽  
Vol 20 (8) ◽  
pp. 690-695 ◽  
Author(s):  
Vito Priolo ◽  
Marisa Masucci ◽  
Eva Spada ◽  
Daniela Proverbio ◽  
Maria Grazia Pennisi

Objectives The aim of this study was to investigate the presence of naturally occurring antibodies against canine erythrocyte antigens in cats and vice versa. The influence of canine and feline blood type on cross-match results was also studied. Methods Blood samples from 34 cats and 42 dogs were used to perform test tube major and minor cross-match tests and blood typing. Blood from each cat was cross-matched with blood from 2–6 dogs, for a total of 111 cross-match tests. Haemolysis, macro- and microagglutination were considered markers of a positive cross-match. Results Eighty-three overall major cross-match tests were positive at 37°C, 86 at room temperature and 90 at 4°C. The minor cross-match tests were positive in all but two cross-matches performed at 37°C, all tests performed at room temperature and all but one test performed at 4°C. No cats tested totally negative at both major and minor cross-matches performed with samples from any single dog. Prevalence of warm natural antibodies against canine erythrocyte antigens was lower in type B cats than in type A cats, regardless of the blood type of donor dogs. Conclusions and relevance This study reveals a high prevalence of naturally occurring antibodies in cats against dog erythrocyte antigens and vice versa, and suggests that transfusion of cats with canine blood is not recommended as a routine procedure owing to the potential high risk of either acute severe or milder transfusion reactions.


2001 ◽  
Vol 8 (4) ◽  
pp. 718-723 ◽  
Author(s):  
Daniel E. Roth ◽  
David N. Taylor ◽  
Robert H. Gilman ◽  
Rina Meza ◽  
Uriel Katz ◽  
...  

ABSTRACT The Helicobacter pylori stool antigen enzyme immunoassay (HpSA) was evaluated during posttreatment follow-up of patients in a country with a very high prevalence of H. pylori infection. From among 273 dyspeptic individuals (18 to 55 years) initially recruited from a shantytown in Lima, Peru, 238 participants who met the inclusion criteria and were suspected to beH. pylori positive based on 14C urea breath test (UBT) results underwent endoscopy. Participants with endoscopy-proven infections received standard eradication therapy and were monitored by UBT and HpSA at 1 month following treatment and at 3-month intervals for 9 months posttreatment. A second endoscopy was performed if UBT results showed evidence of treatment failure orH. pylori recurrence. Biopsy results were considered the “gold standard” in all analyses. Among patients who underwent endoscopy, HpSA had a pretreatment sensitivity of 93%. Two-hundred thirty patients completed the treatment regimen, of whom 201 (93%) were considered to have had successful treatment outcomes based on a negative follow-up UBT. Thirty-two patients with UBT-defined treatment failures or H. pylori recurrences at any point during the 9-month follow-up underwent a second endoscopy. In the posttreatment setting, HpSA had an overall sensitivity of 73% and a specificity of 67%. Agreement between UBT and HpSA diminished throughout the follow-up. Among 14 participants in whom HpSA remained positive at 1 month following treatment despite UBT evidence of treatment success, 12 (86%) became HpSA negative within 3 months posttreatment. Although this study confirmed the validity of the HpSA in the initial assessment of dyspeptic patients, the test demonstrated a reduced overall accuracy in the detection of treatment failures and H. pylorirecurrences during 9 months of posttreatment follow-up. Furthermore, in some patients it may take up to 3 months after successful eradication for antigen shedding to diminish to levels within the negative HpSA range.


1980 ◽  
Vol 30 (3) ◽  
pp. 723-727
Author(s):  
R W Bolton

Sprague-Dawley rats which produce "naturally occurring" antibodies to glycerol teichoic acid (GTA) displayed immunosuppression of anti-sheep erythrocyte plaque-forming cell and serum antibody responses when a single dose of lipid-free GTA was administered 24 h before immunization. Such suppression was enhanced by administering GTA complexed with anti-GTA immunoglobulin G. Animals fed a GTA-free diet produced no anti-GTA immunoglobulins and failed to show GTA-mediated immunosuppression under similar experimental conditions. However, when those animals were given GTA-anti-GTA complexes, suppression was evident. The results suggested antigenic competition mediated by immune complex-activated suppressor T cells. Lipid-free GTA did not stimulate serum antibody responses under the experimental conditions employed.


2012 ◽  
pp. 129-134
Author(s):  
Thi Lan Tran ◽  
Thi Huong Le ◽  
Xuan Ninh Nguyen

Objectives: Assess the nutritional status, worm infection status and some related factors among children aged 12-36 months of Dakrong district, Quang Tri province. Subject and method: A cross sectional study was carried out in 2010, in 680 children aged 12-36 months in 4 communes of Dakrong district, Quang Tri province. Results: The malnutrition rate was 55.0% for underweight, 66.5% for stunting and 16.2% for wasting. The prevalence of malnutrition increases by age group. The prevalence of worm infection was 31.6%, the highest prevalence was belong to Ascaris infection (24.6%), followed by Hookworm and Trichuris (6.5% and 6.2%, respectively). The prevalence of worm infection among children under two is very high (27.0%). The prevalence of worm infection was distributed quite equally between the malnutrition children group and normal children group. Recommendation: Early deworming forchildren from 12 months should be considered as important strategy against the malnutrition of children in Dakrong district, Quang Tri province


2020 ◽  
Vol 13 (12) ◽  
pp. e238069
Author(s):  
Aparna Sharma ◽  
Nilofar Noor ◽  
Vatsla Dadhwal

Neurological manifestations of hypothyroidism include peripheral neuropathy and pituitary hyperplasia. However, these associations are rarely encountered during pregnancy. We report a case of a known hypothyroid with very high thyroid stimulating hormone (TSH) values (512 μIU/mL) in the second trimester. At 24 weeks she developed facial palsy and pituitary hyperplasia which responded to a combination of steroids and thyroxine. She had caesarean delivery at 35 weeks and 3 days gestation in view of pre-eclampsia with severe features and was discharged on oral antihypertensives and thyroxine. On follow-up at 5 months, TSH normalised and pituitary hyperplasia showed a greater than 50% reduction in size. To our knowledge, this is the first reported case of facial palsy and pituitary hyperplasia associated with hypothyroidism during pregnancy.


2021 ◽  
Vol 10 (6) ◽  
pp. 1314
Author(s):  
Rebeca Lorca ◽  
Isaac Pascual ◽  
Andrea Aparicio ◽  
Alejandro Junco-Vicente ◽  
Rut Alvarez-Velasco ◽  
...  

Background: Coronary artery disease (CAD) is the most frequent cause of ST-segment elevation myocardial infarction (STEMI). Etiopathogenic and prognostic characteristics in young patients may differ from older patients and young women may present worse outcomes than men. We aimed to evaluate the clinical characteristics and prognosis of men and women with premature STEMI. Methods: A total 1404 consecutive patients were referred to our institution for emergency cardiac catheterization due to STEMI suspicion (1 January 2014–31 December 2018). Patients with confirmed premature (<55 years old in men and <60 in women) STEMI (366 patients, 83% men and 17% women) were included (359 atherothrombotic and 7 spontaneous coronary artery dissection (SCAD)). Results: Premature STEMI patients had a high prevalence of classical cardiovascular risk factors. Mean follow-up was 4.1 years (±1.75 SD). Mortality rates, re-hospitalization, and hospital stay showed no significant differences between sexes. More than 10% of women with premature STEMI suffered SCAD. There were no significant differences between sexes, neither among cholesterol levels nor in hypolipemiant therapy. The global survival rates were similar to that expected in the general population of the same sex and age in our region with a significantly higher excess of mortality at 6 years among men compared with the general population. Conclusion: Our results showed a high incidence of cardiovascular risk factors, a high prevalence of SCAD among young women, and a generally good prognosis after standardized treatment. During follow-up, 23% suffered a major cardiovascular event (MACE), without significant differences between sexes and observed survival at 1, 3, and 6 years of follow-up was 96.57% (95% CI 94.04–98.04), 95.64% (95% CI 92.87–97.35), and 94.5% (95% CI 91.12–97.66). An extra effort to prevent/delay STEMI should be invested focusing on smoking avoidance and optimal hypolipemiant treatment both in primary and secondary prevention.


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