scholarly journals Molecular Characterization of the Carboxypeptidase B1 of Anopheles stephensi and Its Evaluation as a Target for Transmission-Blocking Vaccines

2013 ◽  
Vol 81 (6) ◽  
pp. 2206-2216 ◽  
Author(s):  
Abbasali Raz ◽  
Navid Dinparast Djadid ◽  
Sedigheh Zakeri
Keyword(s):  
Malaria Vector ◽  
Anopheles Stephensi ◽  
Polyclonal Antibodies ◽  
Test Group ◽  
Malaria Vectors ◽  
Parasite Development ◽  
Control Group ◽  
Transmission Blocking ◽  
Content Type ◽  
Transmission Blocking Vaccines

ABSTRACTMalaria is one of the most important infectious diseases in the world, and it has many economic and social impacts on populations, especially in poor countries. Transmission-blocking vaccines (TBVs) are valuable tools for malaria eradication. A study onAnopheles gambiaerevealed that polyclonal antibodies to carboxypeptidase B1 ofA. gambiaecan block sexual parasite development in the mosquito midgut. Hence, it was introduced as a TBV target in regions whereA. gambiaeis the main malaria vector. However, in Iran and neighboring countries as far as China, the main malaria vector isAnopheles stephensi. Also, the genome of this organism has not been sequenced yet. Therefore, in this study, carboxypeptidase B1 ofA. stephensiwas characterized by genomic and proteomic approaches. Furthermore, its expression pattern after ingestion ofPlasmodium falciparumgametocytes and the effect of anti-CPBAs1 antibodies on sexual parasite development were evaluated. Our results revealed that thecpbAs1expression level was increased after ingestion of the mature gametocytes ofP. falciparumand that anti-CPBAs1 directed antibodies could significantly reduce the mosquito infection rate in the test group compared with the control group. Therefore, according to our findings and with respect to the high similarity of carboxypeptidase enzymes between the two main malaria vectors in Africa (A. gambiae) and Asia (A. stephensi) and the presence of other sympatric vectors, CPBAs1 could be introduced as a TBV candidate in regions whereA. stephensiis the main malaria vector, and this will broaden the scope for the potential wider application of CPBAs1 antigen homologs/orthologs.

scholarly journals Synergy in anti-malarial pre-erythrocytic and transmission-blocking antibodies is achieved by reducing parasite density

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Ellie Sherrard-Smith ◽  
Katarzyna A Sala ◽  
Michael Betancourt ◽  
Leanna M Upton ◽  
Fiona Angrisano ◽  
...  
Keyword(s):  
Parasite Density ◽  
Malaria Control ◽  
Malaria Elimination ◽  
Plasmodium Berghei ◽  
Anopheles Stephensi ◽  
Direct Evidence ◽  
Human Infection ◽  
Transmission Blocking ◽  
Blocking Antibodies ◽  
Transmission Blocking Vaccines

Anti-malarial pre-erythrocytic vaccines (PEV) target transmission by inhibiting human infection but are currently partially protective. It has been posited, but never demonstrated, that co-administering transmission-blocking vaccines (TBV) would enhance malaria control. We hypothesized a mechanism that TBV could reduce parasite density in the mosquito salivary glands, thereby enhancing PEV efficacy. This was tested using a multigenerational population assay, passaging Plasmodium berghei to Anopheles stephensi mosquitoes. A combined efficacy of 90.8% (86.7–94.2%) was observed in the PEV +TBV antibody group, higher than the estimated efficacy of 83.3% (95% CrI 79.1–87.0%) if the two antibodies acted independently. Higher PEV efficacy at lower mosquito parasite loads was observed, comprising the first direct evidence that co-administering anti-sporozoite and anti-transmission interventions act synergistically, enhancing PEV efficacy across a range of TBV doses and transmission intensities. Combining partially effective vaccines of differing anti-parasitic classes is a pragmatic, powerful way to accelerate malaria elimination efforts.

Large-scale 3D printing technology based on the visual stitching method

2019 ◽  
Vol 25 (7) ◽  
pp. 1232-1240 ◽  
Author(s):  
Jianran Lv ◽  
Hongyao Shen ◽  
Jianzhong Fu
Keyword(s):  
3D Printing ◽  
Coordinate Transformation ◽  
Large Scale ◽  
Test Group ◽  
Point Method ◽  
Control Group ◽  
Layer By Layer ◽  
Positioning Accuracy ◽  
Content Type ◽  
Segmentation Point

Purpose 3D printing for objects whose size exceeds the scope of the printer is still a tough challenge in application. The purpose of this paper is to propose a visual stitching large-scale (VSLS) 3D-printing method to solve this problem. Design/methodology/approach The single segmentation point method and multiple segmentation point method are proposed to adaptively divide each slice of the model into several segments. For each layer, the mobile robot will move to different positions to print each segment, and every time it arrives at the planned location, the contours of the printed segments are captured with a high-definition camera by the feature point recognition algorithm. Then, the coordinate transformation is implemented to adjust the printing codes of the next segment so that each part can be perfectly aligned. The authors print up layer by layer in this manner until the model is complete. Findings In Section 3, two specimens, whose sizes are 166 per cent and 252 per cent of the scope of the 3D-printing robot, are successfully printed. Meanwhile, the completed models of the specimens are printed using a suitable traditional printer for comparison. The result shows that the specimens in the test group have basically identical sizes to those in the control group, which verifies the feasibility of the VSLS method. Originality/value Unlike most of the current solutions that demand harsh requirement for positioning accuracy of the mobile robots, the authors use a camera to compensate for the lost positioning accuracy of the device during movement, thereby avoiding precise control to the device’s location. And the coordinate transformation is implemented to adjust the printing codes of the next sub-models so that each part can be aligned perfectly.

Effectiveness of instructor-led collaborative learning in the classroom

2015 ◽  
Vol 7 (2) ◽  
pp. 134-145 ◽  
Author(s):  
Kenneth David Strang
Keyword(s):  
Collaborative Learning ◽  
Regression Model ◽  
Linear Model ◽  
Test Group ◽  
Influential Factor ◽  
Control Group ◽  
Exam Score ◽  
High Stakes ◽  
Content Type ◽  
Exam Scores

Purpose – Collaborative learning was examined as a pedagogy to determine if students could improve standardized exam scores when the professor led the sessions in class. The purpose of this paper is to design a quasi-experiment to test the predictive ability of this pedagogy using a randomly allocated treatment vs control group. An externally administered standardized exam was used as the instrument. Design/methodology/approach – A post-positivist ideology was employed, quantitative data were collected from standardized exit exams scores and from the experiment factors. Descriptive statistics, correlation analysis along with a General Linear Model (GLM) ANCOVA were applied to test the hypothesis at the 95 percent confidence level. Findings – A statistically significant model was developed using multiple regression in a Generalized Linear Model. The regression model developed in this study was able to capture 51 percent of variance on the exam score, using four predictors were (in order of importance): SAT, pedagogy, GPA, and gender. Research limitations/implications – The GLM regression model proved that collaborative learning as pedagogy could increase standardized exam scores, since the only variation between the treatment vs control group was the pedagogy. Prior ability was still the most influential factor in the model, but when it was controlled for, pedagogy (collaborative learning) was shown to help students in the test group make a significant increase in exam score. Practical implications – Business schools and other disciplines could apply the collaborative learning as a pedagogy to help students increase high-stakes exam scores, regardless of their gender, age, or prior ability. Several ideas were mentioned for replacing existing high-stakes exams. Originality/value – A high degree of experimental control was imposed and the common predictors identified in the literature were tested to control for confounding influences. The researcher reflected on what really worked as techniques within the collaborative learning pedagogy process.

scholarly journals The genome trilogy of Anopheles stephensi, an urban malaria vector, reveals structure of a locus associated with adaptation to environmental heterogeneity

2021 ◽  
Author(s):  
Aditi Thakare ◽  
Chaitali Ghosh ◽  
Tejashwini Alalamath ◽  
Naveen Kumar ◽  
Himani Narang ◽  
...  
Keyword(s):  
Malaria Vector ◽  
Anopheles Stephensi ◽  
Environmental Heterogeneity ◽  
Developmental Stages ◽  
Direct Consequence ◽  
Malaria Vectors ◽  
Laboratory Populations ◽  
Exonic Snps ◽  
Water Tanks ◽  
Survival Of The Fittest

Background: Anopheles stephensi is the most menacing malaria vector to watch for in newly urbanizing parts of the world. The fitness is reported to be a direct consequence of the vector adapting to laying eggs in over-head water tanks with street-side water puddles polluted by oil and sewage. Large frequent inversions of malaria vectors are implicated in adaptation. Results: We report the assembly of a strain of An. stephensi of the type-form, collected from a construction site from Chennai (IndCh) in 2016. The genome completes the trilogy with respect to a 16 Mbp inversion (2Rb) in An. stephensi associated with adaptation to environmental heterogeneity. Comparative genome analysis revealed breakpoint structure and allowed extraction of 22,650 segregating SNPs for typing this inversion. Using whole genome sequencing of 82 individual mosquitoes, we conclude that one third of both wild and laboratory populations maintain heterozygous genotype of 2Rb. The large number of SNPs are tailored to assign inversion genotype directly from 1740 exonic SNPs 80% of which are expressed in various developmental stages. Conclusions: The genome trilogy approach accelerates study of fine structure and typing of important inversions in malaria vectors putting the genome resources for the much understudied An. stephensi, on par with the extensively studied malaria vector, Anopheles gambiae. We argue that the IndCh genome is relevant for field translation work compared to those reported earlier by showing that individuals from diverse populations cluster with IndCh pointing to significant commerce between cities, perhaps, allowing for survival of the fittest strain.

Definition of cellular immune responses to brain antigens in human head trauma

1979 ◽  
Vol 51 (3) ◽  
pp. 317-322 ◽  
Author(s):  
Michael L. J. Apuzzo ◽  
Khalid M. A. Sheikh ◽  
James S. Heiden ◽  
Martin H. Weiss ◽  
Theodore Kurze
Keyword(s):  
Immune Responses ◽  
Traumatic Event ◽  
Test Group ◽  
Control Group ◽  
Second Phase ◽  
Normal Brain ◽  
Content Type ◽  
Cellular Immune Responses ◽  
Brain Antigen ◽  
Cellular Immune

✓ Cellular immune responses to brain antigens in patients with head injury were studied by applying the leukocyte adherence inhibition (LAI) assay. The investigation was conducted in three phases. 1) In the initial phase, evaluation of a series of 22 test and 25 control cases obtained at random during a 2- to 6-week time frame following a traumatic event indicated significant non-adherence of leukocytes (NAL) in 77% of the test group and 20% of the control group in the presence of brain antigen. 2) In a second phase, a larger test population was divided into four groups of different posttraumatic intervals. This study measured NAL in the presence of normal heart or normal brain antigen. Assays revealed an initial significant NAL in the presence of both antigens; however, after the first week following injury the majority of cases manifested significant NAL only with brain antigen. These values of NAL persisted over a 6- to 8-week period. 3) As a final phase of investigation, analysis of a sequential series of assays in 12 patients over a 90-day period indicated significant NAL in the presence of brain antigen within the first week of injury, this was followed by a drop in NAL in most of the cases. Studies at 7 to 60 days posttrauma demonstrated significant NAL with brain antigen alone, with a subsequent drop by 90 days. These observations are interpreted to represent sensitization of leukocyte subgroups to brain proteins that are immunologically recognized following the traumatic event.

scholarly journals Transmission-Blocking Vaccines: Old Friends and New Prospects

2019 ◽  
Vol 87 (6) ◽  
Author(s):  
Festus K. Acquah ◽  
Joshua Adjah ◽  
Kim C. Williamson ◽  
Linda E. Amoah
Keyword(s):  
Clinical Trials ◽  
Plasmodium Falciparum ◽  
Life Cycle ◽  
Surface Antigens ◽  
Transmission Blocking ◽  
Content Type ◽  
Transmission Cycle ◽  
Mosquito Midgut ◽  
Transmission Blocking Vaccines ◽  
Old Friends

ABSTRACTIn the progression of the life cycle ofPlasmodium falciparum, a small proportion of asexual parasites differentiate into male or female sexual forms called gametocytes. Just like their asexual counterparts, gametocytes are contained within the infected host’s erythrocytes (RBCs). However, unlike their asexual partners, they do not exit the RBC until they are taken up in a blood meal by a mosquito. In the mosquito midgut, they are stimulated to emerge from the RBC, undergo fertilization, and ultimately produce tens of thousands of sporozoites that are infectious to humans. This transmission cycle can be blocked by antibodies targeting proteins exposed on the parasite surface in the mosquito midgut, a process that has led to the development of candidate transmission-blocking vaccines (TBV), including some that are in clinical trials. Here we review the leading TBV antigens and highlight the ongoing search for additional gametocyte/gamete surface antigens, as well as antigens on the surfaces of gametocyte-infected erythrocytes, which can potentially become a new group of TBV candidates.

scholarly journals The impact of smoke from grilled fish on the hematological parameters of Indonesian grilled fish sellers

2019 ◽  
Vol 34 (2) ◽  
pp. 160-167
Author(s):  
Dwi Purbayanti ◽  
Rinny Ardina ◽  
Syahrida Dian Ardhany ◽  
Rudi Gunawan ◽  
Mohammad Rizki Fadhil Pratama
Keyword(s):  
Hematological Parameters ◽  
Test Group ◽  
Mean Value ◽  
Control Group ◽  
Long Term Effects ◽  
Mixed Cell ◽  
Content Type ◽  
Cell Parameters ◽  
Hematological Analysis ◽  
The Impact

Purpose Fish processing by grilling can produce emissions that contain toxic compounds that can have short- and long-term effects on human health. Another study reported that exposure to air pollutants is hematotoxic. The purpose of this paper is to determine the effect of smoke exposure on fish grill results on hematological parameters. Design/methodology/approach The subjects of this study were 90 grilled fish sellers, with 32 processed food sellers who did not sell grill food as a control. The hematological analysis was performed using the Hematology Analyzers KX300 instrument. Findings The results showed that the mean value of hematological parameters in the test group was higher than the control group except for the number of lymphocytes and mixed cell parameters. Originality/value The content of harmful compounds contained in fish grill smoke can increase hematological value in the blood of exposed individuals, which has the potential for health problems and disease progression.

The blood-brain barrier following experimental subarachnoid hemorrhage

1983 ◽  
Vol 58 (3) ◽  
pp. 345-351 ◽  
Author(s):  
Eric W. Peterson ◽  
Erico R. Cardoso
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Blood Brain Barrier ◽  
Test Group ◽  
Brain Barrier ◽  
Control Group ◽  
Blue Dye ◽  
Control Series ◽  
Content Type ◽  
Blood Brain ◽  
Adult Cats

✓ Under controlled physiological conditions, fresh blood was injected into the cisterna magna of 10 adult cats to produce subarachnoid hemorrhage (SAH). Damage to the blood-brain barrier (BBB) was induced 30 minutes after SAH by the intracarotid injection of a 6 × 10−5M solution of mercuric chloride (HgCl2). A control series of five cats received the same injection of HgCl2. Intravenously injected Evans blue dye was used to indicate areas of BBB damage. The lesions were confirmed by fluorescence microscopy. All control animals showed BBB damage in the hemisphere injected with HgCl2. Of the animals in the test group with SAH, 90% were free from lesions. When lesions were present, the distribution differed from that in the control group. These results bear a similarity to the reported absence of HgCl2 lesions during the acute stages after total cerebral ischemia. This suggests that the cellular components of the BBB participate in a general metabolic inhibition following SAH.

scholarly journals A mating-induced reproductive gene promotes Anopheles tolerance to Plasmodium falciparum infection

2020 ◽  
Vol 16 (12) ◽  
pp. e1008908
Author(s):  
Perrine Marcenac ◽  
W. Robert Shaw ◽  
Evdoxia G. Kakani ◽  
Sara N. Mitchell ◽  
Adam South ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Anopheles Stephensi ◽  
Steroid Hormone ◽  
Field Studies ◽  
Falciparum Infection ◽  
Malaria Vectors ◽  
Parasite Development ◽  
Anopheles Coluzzii ◽  
Fitness Costs ◽  
Mating Status

Anopheles mosquitoes have transmitted Plasmodium parasites for millions of years, yet it remains unclear whether they suffer fitness costs to infection. Here we report that the fecundity of virgin and mated females of two important vectors—Anopheles gambiae and Anopheles stephensi—is not affected by infection with Plasmodium falciparum, demonstrating that these human malaria parasites do not inflict this reproductive cost on their natural mosquito hosts. Additionally, parasite development is not impacted by mating status. However, in field studies using different P. falciparum isolates in Anopheles coluzzii, we find that Mating-Induced Stimulator of Oogenesis (MISO), a female reproductive gene strongly induced after mating by the sexual transfer of the steroid hormone 20-hydroxyecdysone (20E), protects females from incurring fecundity costs to infection. MISO-silenced females produce fewer eggs as they become increasingly infected with P. falciparum, while parasite development is not impacted by this gene silencing. Interestingly, previous work had shown that sexual transfer of 20E has specifically evolved in Cellia species of the Anopheles genus, driving the co-adaptation of MISO. Our data therefore suggest that evolution of male-female sexual interactions may have promoted Anopheles tolerance to P. falciparum infection in the Cellia subgenus, which comprises the most important malaria vectors.

The effect of transmission-blocking antibody ingested in primary and secondary bloodfeeds, upon the development ofPlasmodium bergheiin the mosquito vector

Parasitology ◽  
1993 ◽  
Vol 107 (3) ◽  
pp. 225-231 ◽  
Author(s):  
G. Ranawaka ◽  
R. Alejo-Blanco ◽  
R. E. Sinden
Keyword(s):  
Plasmodium Berghei ◽  
Anopheles Stephensi ◽  
Similar Efficacy ◽  
Parasite Development ◽  
Mosquito Vector ◽  
Blocking Antibody ◽  
Transmission Blocking ◽  
Mean Intensity ◽  
Monoclonal Immunoglobulins ◽  
Transmission Enhancement

SummaryThe effects of purified monoclonal immunoglobulins from control, or transmission-blocking anti-Pbs21 antibodies, upon the infection ofAnopheles stephensiby ookinetes ofPlasmodium bergheiare compared. Anti-Phs21 antibody reduced mean intensity and prevalence of infection by 94·7 and 58·7% respectively if added to the infectious bloodfeed at a concentration of 100 μg/ml. Fab fragments were of similar efficacy. No transmission enhancement was detected with declining antibody concentrations. Addition to subsequent (second) feeds reduced mean oocyst intensity but not prevalence. The reduction in blockade declined from 41% at day 2, to 4% at day 8. Second bloodfeeds, containing control globulin taken 4 or 6 days (but not 2 days) after infection, increased sporozoite burden in the salivary glands. At all times anti-Pbs21 reduced sporozoite number in the thorax compared to time-matched controls, but again highest gland intensities were obtained when the second bloodfeed was given on day 4. We conclude that second bloodfeeds containing transmission-blocking antibody simultaneously serve two opposing roles, (1) inhibition of parasite development and (2) the supply of nutrients which permit more sporozoites to be produced by each oocyst.

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