scholarly journals Bisphenol A Acts As Developmental Agonist in Culex Quinquefasciatus Say

2021 ◽  
Author(s):  
Ayana Gayathri ◽  
Evans DA
Keyword(s):  
Bisphenol A ◽  
Culex Quinquefasciatus ◽  
Atmospheric Temperature ◽  
Pupal Development ◽  
Breeding Sites ◽  
Significant Difference ◽  
Mosquito Breeding ◽  
Summer Rain ◽  
Dose Dependent ◽  
Embryonic And Larval Development

Abstract Plastic – derived Bisphenol A (BPA) contaminated sewages in Trivandrum, Kerala, India are mosquito breeding sites. After summer rain, BPA in the stagnant water samples ranged between 0.86 and 1.14ppm. 1.0 ppm BPA is considered as environmentally relevant concentration. Present study revealed that BPA is a developmental agonist of Culex quinquefasciatus. Embryonic and larval development are shortened by BPA but pupal development is unaffected. Under the atmospheric temperature of 26 to 310C lifecycle was completed within 312 hours but during summer it was completed within 278 hours, meanwhile atmospheric temperature ranged between 30 and 370C. Reduction in the duration of development due to BPA was 50 to 70 hours during summer and 60 to 80 hours in other seasons. Larval – pupal stadium of the mosquito has three surges of 20-hydroxy ecdysone(20-HE), at 24,32 and 48th hour of the 4th instar. BPA resulted dose-dependent advancement of 20-HE peaks, Phospholipase A2 induction and expression of Ecdysone receptor EcRA and Ecdysone inducible gene E75A, which culminated in early pupation. Adults emerging from 1.0 ppm BPA treatment did not show significant difference in sanguivory and fecundity compared to control but pupae developed in 2 and 4 ppm BPA were significantly small.

scholarly journals Dynamics of residual malaria transmission in Central Western Senegal: Mapping the breeding sites of Anopheles gambiae s. l

2020 ◽  
Author(s):  
A. Ndiaye ◽  
E.A Niang ◽  
A. Niang-Diène ◽  
M. A. Nourdine ◽  
P C Sarr ◽  
...  
Keyword(s):  
Malaria Transmission ◽  
Water Retention ◽  
Effective Control ◽  
Annual Number ◽  
Breeding Sites ◽  
Exact Test ◽  
Significant Difference ◽  
Residual Malaria Transmission ◽  
Mosquito Breeding ◽  
Determining Factor

AbstractDespite the use of several effective control interventions in the central western Senegal, residual malaria transmission still occurring in some hotspots. In order to better understand the factors associated with this situation to better tailor targeted control actions, it is critical to unravel environmental and geographical factors underlying the persistence of the disease in study hotspot villages. Hotspots villages were defined as those reporting more than six indigenous malaria cases during the previous year. A total of ten villages, including seven hotspots and three non-hotspots, were surveyed. All potential mosquito breeding sites identified in and around the tenth study villages were regularly monitored between 2013 and 2017. This monitoring concerned the presence of anophelines larvae and the collection of epidemiological, hydrogeological, topographical and biogeographical data. Throughout the study area, the number of larval breeding sites inventoried and monitored over the study period ranged from 50 to 62. They were higher, with no significant difference, in hotspot sites than in non-hotspot sites for each year of monitoring with 62.3% (56/62) in 2013, 90.9% (50/55) in 2014, 90.3% (56/62) in 2015 and 86% (43/50) in 2017 (Fisher’s exact test; p = 1). The Hotspot villages were mostly characterized by saline or moderately saline hydro-morphic and halomorphic soils allowing water retention and a suitable presence of potential larval breeding sites. Whereas non-hotspot villages are characterized mainly by a high proportion of extremely permeable sandy-textured soils due to their porosity, which reduces water retention. The annual number of confirmed malaria cases was corelated relatively with the frequency and extent of breeding sites. Malaria cases were much more higher in the hamlets located near to the breeding sites of An. gambiae s.l then gradually decreases with their remoteness. This study has shown that the dynamics of larval breeding sites by their longevity, stability, proximity to houses and their positiveness rate for the presence of Anopheles larvae could be a determining factor in the persistence of malaria hotspots in central western Senegal. The results of this study shed more light on the environmental factors underlying the residual transmission and should make it possible to better organize vector control interventions for malaria elimination in west-central Senegal.

scholarly journals Residential characteristics aggravating infestation by Culex quinquefasciatus in a region of Northeastern Brazil

2012 ◽  
Vol 46 (6) ◽  
pp. 935-941 ◽  
Author(s):  
Juliana Cavalcanti Correia ◽  
Rosângela Maria Rodrigues Barbosa ◽  
Cláudia Maria Fontes de Oliveira ◽  
Cleide Maria Ribeiro de Albuquerque
Keyword(s):  
Water Supply ◽  
Culex Quinquefasciatus ◽  
Control Measures ◽  
Northeastern Brazil ◽  
Septic Tank ◽  
Water Drainage ◽  
Breeding Sites ◽  
Residential Characteristics ◽  
Significant Difference ◽  
Basic Sanitation

OBJECTIVE: Analyse how basic sanitation conditions, water supply and housing conditions affect the concentration of Culex quinquefasciatus METHODS: Populations of C. quinquefasciatus in 61 houses in the municipality of Olinda, PE, were monitored between October 2009 and October 2010. Observations were carried out in homes without the presence of preferred breeding sites in order to identify characteristics that may be aggravating factors for the development of the mosquito. Five aggravating factors were analysed: vegetation cover surrounding the home, number of residents/home, water storage, sewage drainage and water drainage. These characteristics were analysed in terms of presence or absence and as indicators of the degree of infestation, which was estimated through monitoring the concentration of eggs (oviposition traps - BR-OVT) and adults (CDC light traps). RESULTS: Sewage drainage to a rudimentary septic tank or to the open air was the most frequent aggravating factor in the homes (91.8%), although the presence of vegetation was the only characteristic that significantly influenced the increase in the number of egg rafts (p = 0.02). The BR-OVT achieved positive results in 95.1% of the evaluations, with the presence of at least one egg raft per month. A total of 2,366 adults were caught, with a mosquito/room/night ratio of 32.9. No significant difference was found in the number of mosquitoes caught in the homes. CONCLUSIONS: Although the sanitation and water supply influence the population density of C. quinquefasciatus, residence features that are not usually considered in control measures can be aggravating factors in sustaining the mosquito population.

Automatic detection of potential mosquito breeding sites from aerial images acquired by unmanned aerial vehicles

2021 ◽  
Vol 90 ◽  
pp. 101692
Author(s):  
Daniel Trevisan Bravo ◽  
Gustavo Araujo Lima ◽  
Wonder Alexandre Luz Alves ◽  
Vitor Pessoa Colombo ◽  
Luc Djogbénou ◽  
...  
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Automatic Detection ◽  
Aerial Images ◽  
Breeding Sites ◽  
Aerial Vehicles ◽  
Mosquito Breeding

Immunomodulatory activities of whey fractions in efferent prefemoral lymph of sheep

1996 ◽  
Vol 63 (2) ◽  
pp. 257-267 ◽  
Author(s):  
Chun W. Wong ◽  
Geoffrey O. Regester ◽  
Geoffrey L. Francis ◽  
Dennis L. Watson
Keyword(s):  
Immune Responses ◽  
Bovine Milk ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
Milk Whey ◽  
Significant Difference ◽  
Lymphocyte Phenotypes ◽  
Dose Dependent

SummaryStudies on the immunomodulatory activities of ruminant milk and colostral whey fractions were undertaken. By comparing with boiled colostral whey in a preliminary experiment, a putative heat-labile immunostimulatory factor for antibody responses was found to be present in ovine colostral whey. Studies were then undertaken in sheep in which the efferent prefemoral lymphatic ducts were cannulated bilaterally, and immune responses in the node were measured following subcutaneous injection in the flank fold of whey protein preparations of various purities. A significant sustained decline of efferent lymphocyte output was observed following injection with autologous crude milk whey or colostral whey preparations, but no changes were observed in interferon-gamma levels in lymph plasma. Two bovine milk whey fractions (lactoperoxidase and lactoferrin) of high purity were compared in bilaterally cannulated sheep. A transient decline over the first 6 h was seen in the efferent lymphocyte output and lymph flow rate after injection of both fractions. A significant difference was seen between the two fractions in interferongamma levels in lymph at 6 h after injection. However, no significant changes in the proportion of the various efferent lymphocyte phenotypes were seen following either treatment. Whereas both fractions showed a significant inhibitory effect in a dose-dependent manner on the proliferative response of T lymphocytes, but not B lymphocytes, to mitogenic stimulation in vitro, no similar changes were seen following in vivo stimulation with these two fractions.

Human MutT Homolog 1 (MTH1) Inhibitor Reduces the Biological Activity of Ovarian Carcinoma Cells

2022 ◽  
Vol 12 (5) ◽  
pp. 907-913
Author(s):  
Liyan Zhong ◽  
Yi Yi ◽  
Qian Liu ◽  
Yan Peng
Keyword(s):  
Biological Activity ◽  
Ovarian Carcinoma ◽  
Biological Activities ◽  
Carcinoma Cells ◽  
Dependent Manner ◽  
Ovarian Carcinoma Cells ◽  
Proliferative Rate ◽  
Skov3 Cells ◽  
Significant Difference ◽  
Dose Dependent

This study intends to discuss the mechanism of MTH1 inhibitor (TH588) in the biological activity of ovarian carcinoma cells. A2780 and SKOV-3 cells were treated with different concentrations of TH588 and assigned into AT group (control), BT group (8 μmol/L TH588), CT group (16 μmol/L), DT group (32 μmol/L), ET group (64 μmol/L) and FT group (128 μmol/L) followed by measuring level of Bcl-2 and Bax by Western blot and PCR, and cell biological activities by MTT, FCM and Transwell chamber assay. The cell proliferative rate was not affected in AT group, but was lower in other groups in a reverse dose-dependent manner. There was significant difference on apoptotic rate and cell invasion among groups with increased apoptosis and reduce invasion after TH588 treatment. FT group showed lowest expression of Bcl-2 and Bax compared to other groups. In conclusion, the biological activity of A2780/SKOV3 cells could be reduced by MTH1 inhibitor which was probably through regulation of Bax and Bcl-2 expression.

T-cell receptor pharmacodynamics associated with survival and response to tremelimumab (T) in combination with durvalumab (D) in patients (pts) with unresectable hepatocellular carcinoma (uHCC).

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 4087-4087
Author(s):  
Patricia McCoon ◽  
Young S Lee ◽  
Robin Kate Kelley ◽  
Violeta Beleva Guthrie ◽  
Song Wu ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
Single Agent ◽  
Clonal Expansion ◽  
Cell Receptor ◽  
Combination Regimen ◽  
Cell Counts ◽  
Significant Difference ◽  
Dose Dependent ◽  
Cell Clonal Expansion

4087 Background: Study 22, a phase 2 clinical study (NCT02519348) evaluating T (anti-CTLA-4) and D (anti-PD-L1) as monotherapies and in combination indicated the best efficacy-safety profile with a novel combination regimen containing a single, priming dose of T (T300+D). Additionally, an expansion of proliferative CD8+ lymphocytes at Day 15 was observed with T300+D that was associated with improved response. Here, an exploratory molecular analysis of peripheral blood T cell receptors is presented. Methods: Immune-checkpoint inhibitor-naïve pts were randomized to 1 of 2 T+D combinations: T300+D (T 300 mg [1 dose] + D 1500 mg, then D every 4 weeks [Q4W]) or T75+D (T 75 mg Q4W + D 1500 mg Q4W [4 doses], then D Q4W); or single agent D (1500 mg Q4W) or T (750 mg Q4W [7 doses] then Q12W). DNA was isolated from PAXgene-preserved whole blood collected at baseline and on Day 29 during the first cycle of Q4W dosing, and then underwent CDR3 sequencing of T-cell receptor β using the immunoSEQ Assay (Adaptive Biotechnologies, Seattle, WA). Associations with objective response rate (ORR) and overall survival (OS) were evaluated. Results: The number of evaluable pts, samples, and overall ORR and OS are provided (Table). Immunosequencing analysis did not reveal significant differences in baseline T-cell clonality across arms. Increased T-cell clonal expansion at Day 29 appeared to be T dose dependent (Table), with no significant difference in the median expansion between the D and T75+D arms. Across all arms, responders had a larger median number of expanded T-cell clones on Day 29 than nonresponders (77.5 vs 40), and this greater expansion trended with longer OS (Table). Further evaluation by arm demonstrated an increase in T-cell clonal expansion in responders vs nonresponders in the T300+D arm. Pts with T-cell expansion above the median in the T300+D and T75+D arms also exhibited longer OS. Both newly expanded and total expanded clones on Day 29 vs Day 1 were associated with improved OS. Conclusions: The observed T dose-dependent increase in T-cell clonal expansion trended with improved ORR and longer OS, with the greatest overall benefit seen with T300+D vs T75+D, D and T. This is consistent with the previously reported observation that T300+D led to the highest median proliferating CD8+ T-cell counts and radiographic response. Further work is needed to differentiate the relative contributions of CD4 and CD8 clonal expansion to increased efficacy. T300+D and D are being evaluated in the phase 3 HIMALAYA study (NCT03298451) in uHCC vs sorafenib. Funding: AstraZeneca. Clinical trial information: NCT02519348. [Table: see text]

scholarly journals Studies on mosquitoes (Diptera: Culicidae) and anthropic environment: 2 - Immature stages research at a rice irrigation system location in South-Eastern Brazil

1993 ◽  
Vol 27 (4) ◽  
pp. 227-236 ◽  
Author(s):  
Oswaldo Paulo Forattini ◽  
Iná Kakitani ◽  
Eduardo Massad ◽  
Daniel Marucci
Keyword(s):  
Malaria Vector ◽  
Irrigation System ◽  
Immature Stage ◽  
Immature Stages ◽  
Breeding Sites ◽  
Experimental Station ◽  
Eastern Brazil ◽  
Rice Irrigation ◽  
Mosquito Breeding ◽  
Natural Breeding

A relation between a rice irrigation system and mosquito breeding was established in a study undertaken at the Ribeira Valley Experimental Station, from January through December 1992. Flooding favoured Anopheles (Nyssorhynchus) and Culex (Melanoconion) species, while empty paddies condition were propitious to Aedes scapularis and Culex (Culex) species. Compared with a more primitive area of the same region, several species showed high a degree of adaptation to the anthropic environment. Among them, Anopheles albitarsis, a potential malaria vector that breeds in the irrigation system, has shown immature stage production thirteen times higher than at the natural breeding sites. In addition, Ae. scapularis, An. oswaldoi, Cx. bastagarius, and Cx. chidesteri presented high levels of synanthropy.

Mechanisms of insecticide resistance in a temephos selected Culex quinquefasciatus (Diptera: Culicidae) strain from Sri Lanka

1990 ◽  
Vol 80 (4) ◽  
pp. 453-457 ◽  
Author(s):  
H.T.R. Peiris ◽  
J. Hemingway
Keyword(s):  
Cytochrome P450 ◽  
Sri Lanka ◽  
Culex Quinquefasciatus ◽  
Resistant Strain ◽  
Resistance Mechanism ◽  
Transferase Activity ◽  
Glutathione S Transferase ◽  
Biochemical Assays ◽  
Significant Difference ◽  
Naphthyl Acetate

AbstractCulex quinquefasciatus Say from Peliyagoda, Sri Lanka, has larval resistance to temephos, malathion, fenitrothion and chlorpyrifos. Biochemical assays on individual resistant and susceptible mosquitoes of this strain showed that there was a good correlation between this resistance and increased esterase activity with both 1-and 2-naphthyl acetate, which appears to be the major resistance mechanism in this multiple organophosphate resistant strain. There was no significant difference in malaoxon, bendiocarb or propoxur sensitivity of the acetylcholinesterase from the resistant and susceptible strains, indicating that the sensitivity of the target site has not been altered. Biochemical assays on mass homogenates of the resistant and susceptible strains showed no correlation between resistance and the level of glutathione s-transferase activity, or the amount of cytochrome P450 present.

William Crawford Gorgas and the Panama Canal

2021 ◽  
pp. 198-212
Author(s):  
Robert N. Wiedenmann ◽  
J. Ray Fisher
Keyword(s):  
Yellow Fever ◽  
Panama Canal ◽  
Spanish American ◽  
Theodore Roosevelt ◽  
Spanish American War ◽  
Control Plan ◽  
Breeding Sites ◽  
Successful Strategy ◽  
The Us ◽  
Mosquito Breeding

This chapter relates how yellow fever continued to cause casualties during the US occupation after the Spanish-American War ended and how Major William Crawford Gorgas created a successful strategy to eliminate the disease from Cuba by attacking mosquito breeding sites. It goes on to tell the story of the plan to link the Atlantic and Pacific Oceans, proposed earlier that century, with the Panama Railroad transporting military goods and soldiers, plus those seeking gold in California. A canal was proposed, but the first, French effort to build it cost hundreds of millions of dollars and tens of thousands of workers’ lives lost before capitulating to yellow fever in 1889. Subsequent US construction, begun in 1904, was soon threatened by disease. When Colonel Gorgas brought his yellow fever control plan to Panama he faced criticism from his superiors but gained the support of President Theodore Roosevelt. The chapter relates how his plan, though seemingly improbable, worked, defeating yellow fever, saving countless lives, and allowing the completion of the canal.

Bisphenol A differentially affects male reproductive function biomarkers in a reference population and agro pesticides users from Djutitsa, Cameroon

2019 ◽  
Vol 35 (4) ◽  
pp. 324-335 ◽  
Author(s):  
Faustin Pascal Tsagué Manfo ◽  
Cathérine Harthé ◽  
Edouard Akono Nantia ◽  
Henri Dechaud ◽  
Angèle Nkouatchoua Tchana ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Daily Intake ◽  
Reproductive Function ◽  
Reference Population ◽  
Average Concentration ◽  
Sex Hormone Binding Globulin ◽  
Urinary Concentration ◽  
Total Testosterone ◽  
Male Reproductive Function ◽  
Significant Difference

The consequences of bisphenol A (BPA) exposure on male reproductive function were studied in two populations from Cameroon, farmers using agro pesticides in Djutitsa (rural area) and townsmen in Yaoundé (urban area, Centre region). Urinary BPA concentration from all participants was measured, and the values were correlated with biochemical markers of male reproductive function. The data showed that BPA could be detected in 92.6% of urine participants, with an average concentration of 2.18 ± 1.97 µg/g creatinine but with no significant difference between the urinary BPA concentration from rural and urban populations. From BPA urinary concentration, the BPA average daily intake was estimated to be 0.06 ± 0.05 μg/kg/day (3.51 µg/day per individual) in the Cameroon population. Interestingly, free and bioavailable testosterone concentrations and estradiol/testosterone ratio correlated with BPA levels in the overall population. When data were analysed according to residence, BPA correlated with total testosterone levels ( r = −0.433) and estradiol/testosterone ratio ( r = 0.338) in the urban residents only, while the rural population exhibited significant increases in sex-hormone-binding globulin with increased BPA exposure. Our data showed that the male Cameroon population is exposed to BPA but that inconstant BPA association to endocrine reproductive markers suggests that other environmental factors in combination with BPA exposure might influence testicular function.

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