The role of the antennae in Triatoma infestans: Orientation towards thermal sources

1996 ◽  
Vol 42 (5) ◽  
pp. 433-440 ◽  
Author(s):  
Graciela B. Flores ◽  
Claudio R. Lazzari
1982 ◽  
Vol 72 (4) ◽  
pp. 617-629 ◽  
Author(s):  
C. J. Schofield

AbstractThe growth of populations of Triatoma infestans (Klug) depends on temperature and blood-intake. Experiments are described which demonstrated the density-dependent relationship between population size, blood intake and population growth at different temperatures. The number of bugs feeding and their mean blood intake was lower at high bug densities than at low ones, both with restrained chickens and with unrestrained mice as hosts. When blood intake was restricted, the development times of all nymphal stages were increased, and female fecundity was decreased. Previous work showed also that reduced blood intake led to an increased tendency for adult flight. It is thought that at high bug density the three factors, increased development times, decreased fecundity and increased flight, operate to restore the population to a stable density without promoting an increase in mortality. The mechanism linking population density to nutritional status seemed to depend on host irritability, which interrupted the bugs' feeding. Bugs which passed a certain threshold meal size would not resume feeding if interrupted, even though their blood intake was well below normal. The difference between the minimal threshold meal and a normal meal is thought to provide the nutritional elasticity within which the development processes are regulated. It is suggested that this mechanism is characteristic of K-strategists, whereas r–strategists such as mosquitoes tend to continue attacking, even if interrupted, until they achieve a normal meal.


2020 ◽  
Vol 57 (3) ◽  
pp. 837-844 ◽  
Author(s):  
Georgina Fronza ◽  
Gonzalo Roca-Acevedo ◽  
Gaston A Mougabure-Cueto ◽  
Ivana Sierra ◽  
Natalia Capriotti ◽  
...  

Abstract Chagas disease affects around 6 million people in the world, and in Latin America, it is mainly transmitted by the kissing bug. Chemical control of the vector with pyrethroid insecticides has been the most frequently used tool to reduce the disease incidence. Failures of field control have been detected in areas of the Argentinian Gran Chaco that correlate with high levels of insecticide resistance. Here, we provide evidence of the mechanisms involved in the resistance to insecticides of field populations of T. infestans from General Güemes Department (Chaco Province, Argentina). The biochemical analysis suggests the increase in the activity of the degradative enzymes P450 oxidases and esterases as a minor contributive mechanism in low-resistance populations. The molecular study revealed high frequencies of the kdr L925I mutation at the voltage-gated sodium channel as responsible for the high resistance ratios detected. This knowledge contributes to the generation of comprehensive vector control strategies that reduce the incidence of the disease.


1998 ◽  
Vol 44 (12) ◽  
pp. 1159-1162 ◽  
Author(s):  
Claudio R Lazzari ◽  
Carolina E Reiseman ◽  
Teresita C Insausti

Parasitology ◽  
2005 ◽  
Vol 132 (3) ◽  
pp. 345-355 ◽  
Author(s):  
V. G. DUSCHAK ◽  
M. BARBOZA ◽  
G. A. GARCÍA ◽  
E. M. LAMMEL ◽  
A. S. COUTO ◽  
...  

With the aim to study proteinases released to the culture medium duringTrypanosoma cruzimetacyclogenesis, the presence of cysteine proteinases (CPs) was analysed in culture supernatants obtained throughout the differentiation induced by stimulation of epimastigotes withTriatoma infestanshindgut homogenate. In SDS-gelatin containing gels, an important endopeptidase activity with apparent molecular weight range between 97 and 116 kDa was encountered at pH 6, which was abolished by the specific cysteine proteinase inhibitor E-64 and TLCK, but not by pepstatin, 1,10 phenantroline or PMSF. This novel CP, namedTcCPmet, showed affinity to cystatin-Sepharose, denoting its thiol-proteinase character as well as to ConA-Sepharose, indicating it contains N-linked oligosaccharides. However, it presented a different elution pattern on ConA-Sepharose than cruzipain and, in addition, it was not recognized by anti-cruzipain serum, facts that strongly suggest the different nature of both CPs. Moroever, evidence is presented indicating thatTcCPmet was able to hydrolyse the same chromogenic peptides as cruzipain at optimal alkaline pH values, although with a different order of effectiveness. Our results indicate the presence of a novel CP secreted by metacyclic trypomastigotes and reinforces the important role of these enzymes in metacyclogenesis.


2004 ◽  
Vol 99 (3) ◽  
pp. 335-339 ◽  
Author(s):  
Paola González Audino ◽  
Claudia Vassena ◽  
Silvia Barrios ◽  
Eduardo Zerba ◽  
María Inés Picollo

2015 ◽  
Vol 81 (5) ◽  
pp. 478-482 ◽  
Author(s):  
Sebastiano Cassaro

Bowel injury (BI) is a complication of open and laparoscopic abdominal surgery associated with increased morbidity and mortality. If BI is missed at the time it occurs, it can have devastating consequences. Electrosurgery is used extensively in laparoscopic surgery and can cause thermal injuries that are harder to detect than mechanical injuries and may evolve over time. The medical literature of the past 10 years was searched for large series and compilation studies reporting overall incidence of and mortality from BI in laparoscopy, and the results of seven relevant articles, which included over 300,000 procedures, were analyzed and tabulated. The literature was then reviewed for additional information about the specific incidence and outcome of missed BI and the role of electrosurgical thermal sources in causing BI. BI is underreported, frequently missed at surgery, and results in significant morbidity and mortality that can be ground for malpractice claims against the surgeon. Thermal injury from electrosurgical instruments may be involved in a number of injuries in laparoscopic surgery. Nearly undetectable partial-thickness thermal injury may play a role in the atypical and delayed presentation of some cases of BI.


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