Comparative studies on the sense organs on the antennae and maxillary palps of selected male culicine mosquitoes

1971 ◽  
Vol 49 (2) ◽  
pp. 235-239 ◽  
Author(s):  
Susan McIver
Keyword(s):  
Carbon Dioxide ◽  
Aedes Aegypti ◽  
Comparative Studies ◽  
Culex Pipiens ◽  
Sense Organ ◽  
Sense Organs ◽  
Sensilla Basiconica ◽  
Aedes Atropalpus ◽  
The Difference ◽  
Maxillary Palps

The sense organs on the antennae and maxillary palps of male Aedes atropalpus (Coquillett), Aedes aegypti (L.), Culex territans Walker, and Culex pipiens L. are similar to those observed on female culicines including water, olfactory, and carbon dioxide receptors. Although males have the same variety, they have fewer of each type of sense organ. The difference in number of any one type of sense organ is more variable in the female than the male except for the sensilla basiconica.

Studies on the sense organs on the palps of selected culicine mosquitoes

1970 ◽  
Vol 48 (2) ◽  
pp. 293-295 ◽  
Author(s):  
Susan McIver ◽  
Christel Charlton
Keyword(s):  
Carbon Dioxide ◽  
Aedes Aegypti ◽  
Behavioral Responses ◽  
Ventral Part ◽  
Sense Organs ◽  
Culex Restuans ◽  
Distal Half ◽  
Thin Walled ◽  
Palpal Segment ◽  
Maxillary Palps

Four structures are found on the maxillary palps of female culicine mosquitoes: microtrichia, scales, sensilla chaetica, and thin-walled, bulb-shaped organs. The bulb organs are localized on the distal half of the ventral part of palpal segment 4, have perforated walls, are carbon dioxide receptors (Kellogg, in press), and vary in number among the species from 29/palp on Aedes aegypti to 89/palp on Culex restuans. An explanation for observed behavioral responses to carbon dioxide is given.

scholarly journals The Regulation of Osmotic Pressure and Chloride Concentration in the Haemolymph of Mosquito Larvae

1938 ◽  
Vol 15 (2) ◽  
pp. 235-247 ◽  
Author(s):  
V. B. WIGGLESWORTH
Keyword(s):  
Aedes Aegypti ◽  
Osmotic Pressure ◽  
Culex Pipiens ◽  
Chloride Concentration ◽  
Muscular Activity ◽  
Chloride Content ◽  
Mosquito Larvae ◽  
The Difference ◽  
High Concentrations ◽  
Anal Papillae

The osmotic pressure of the haemolymph in well-fed larvae of Aedes aegypti and Culex pipiens is equivalent to 0.80-0.89% NaCl. During starvation it falls to 0.70% NaCl. The average chloride content of the haemolymph is equivalent to 0.30% NaCl in Aedes, 0.28% in Culex. The non-chloride fraction can be regulated so that the total osmotic pressure remains relatively constant in spite of wide variations in chloride content. The ability of mosquito larvae to take up chloride from dilute solutions (Koch, 1938) is confirmed. In a balanced salt medium both the chloride and osmotic pressure of the blood remain constant until the concentration of the medium reaches o.65-0.75% NaCl. Above this level a variable excess of chloride enters the larva and the total osmotic pressure rises so that it is always a little greater than that of the external medium. At high concentrations (above about 1.6%) the blood chloride rises excessively and all the larvae die. Comparative experiments show that Aedes aegypti is more efficient than Culex pipiens in absorbing and retaining chloride in dilute media, and Culex is perhaps a little better at keeping chloride out in more concentrated media. This difference accords with the difference in their natural breeding places. The anal papillae become greatly enlarged in media almost free from chloride (functional hypertrophy for chloride uptake (Koch, 1938)) and reduced in more concentrated media. The papillae of Culex are more labile in this respect, but the maximum development occurs in Aedes. The ability of larvae to absorb and retain chloride in dilute media is much reduced if they have been reared in more concentrated media. But after transfer to dilute media they soon recover this ability in spite of the reduction in size of the anal papillae. When the larva is deprived of oxygen, muscular activity causes a rise in the osmotic pressure of the blood from about 0.83 to 1.0 or 1.1% NaCl, and this change is associated with extraction of fluid from the tracheoles. But reasons are given for doubting that the level of fluid in the tracheoles is determined by a direct relation between capillarity and osmotic pressure of the blood.

Central projections of the maxillary and antennal nerves in the mosquito Aedes aegypti

1997 ◽  
Vol 200 (13) ◽  
pp. 1873-1879
Author(s):  
P Distler ◽  
J Boeckh
Keyword(s):  
Aedes Aegypti ◽  
Antennal Lobe ◽  
Distal Segment ◽  
Suboesophageal Ganglion ◽  
Central Projections ◽  
Sensilla Basiconica ◽  
Central Target ◽  
Maxillary Nerve ◽  
Projection Pattern ◽  
Maxillary Palps

In the mosquito Aedes aegypti, CO2-sensitive receptor neurones are located together with two other types of chemoreceptor neurones in club-shaped sensilla basiconica on the most distal segment of the maxillary palps. In order to identify the central target neuropiles of these neurones and to determine whether antennal receptor neurones project into the same area, the palpal and antennal nerves were labelled by anterograde staining with horseradish peroxidase and by experimentally induced degeneration. The different methods revealed a consistent projection pattern. (1) Maxillary afferents project into the suboesophageal ganglion and ascend further into the ipsilateral antennal lobe. There, they terminate within an identified glomerulus of the ventroposterior lobe. (2) Afferents of the antennal flagellum project into all glomeruli of the ipsilateral antennal lobe, with the exception of the glomerulus innervated by the maxillary nerve. The present anatomical findings suggest that primary processing of information about CO2 levels takes place in a defined glomerulus which also receives input from other palpal chemoreceptor neurones.

Fine structure of pegs on the palps of female culicine mosquitoes

1972 ◽  
Vol 50 (5) ◽  
pp. 571-576 ◽  
Author(s):  
Susan B. McIver
Keyword(s):  
Carbon Dioxide ◽  
Fine Structure ◽  
Aedes Aegypti ◽  
Culex Pipiens ◽  
Cuticular Structure ◽  
Different Types ◽  
Thin Walled ◽  
Distinctive Cell ◽  
Sheath Cells ◽  
Culex Territans

The fine structure of the thin-walled pegs known to respond to carbon dioxide was studied in Aedes aegypti (L.), Culex pipiens L., and Culex territans Walker. Each peg is composed of an external cuticular structure with numerous pores which occur in groups, three bipolar neurons, and sheath cells. In A. aegypti two morphologically different types of neurons were found innervating the same sensillum: two electron-dense neurons and one electron-lucid neuron per peg. In addition to distinctive cell bodies and nuclei, the two types of neurons have different organization patterns of their dendritic processes within the lumen. Culex pipiens is shown to have several times more area available for perception of carbon dioxide than A. aegypti.

Estudio y evaluación de depredadores y bacterias entomopatógenas de Aedes aegypti (L.) y Culex pipiens (L.), como potenciales agentes de control

2010 ◽  
Author(s):  
◽  
María Cecilia Tranchida
Keyword(s):  
Aedes Aegypti ◽  
Culex Pipiens ◽  
Principal Vector ◽  
La Plata

Aedes aegypti y Culex pipiens se encuentran entre las principales especies de mosquitos vectores de enfermedades a nivel mundial. Ambas, son de gran importancia sanitaria en la Argentina. Aedes aegypti, es el principal vector del dengue y la fiebre amarilla. Está presente en la Argentina desde 1983, cuando fue confirmada su reemergencia en nuestro país. A partir de entonces comenzaron a detectarse casos de dengue hasta que el último brote de esta enfermedad en 2009 produjo 24.720 casos autóctonos confirmados por la OPS a nivel nacional. Culex pipiens es vector de algunas filariasis, y de importantes arbovirosis como la ocasionada por el virus del Nilo Occidental. La actividad vectorial de este mosquito se ve incrementada en zonas donde la densidad de zanjas de desagüe domiciliario es elevada, ya que este tipo de ambiente constituye un lugar propicio para su desarrollo. De su importancia sanitaria nace la necesidad de controlar su actividad vectorial, manteniendo las poblaciones en bajas densidades. El objetivo de este trabajo fue desarrollar estrategias para el control de A. aegypti y C. pipiens, basadas en métodos biológicos, eficaces, permanentes y seguros para el ambiente, mediante el empleo de enemigos naturales presentes en las poblaciones de ambas especies. En este trabajo, fueron evaluados copépodos, turbelarios y peces como depredadores; y bacterias entomopatógenas (α-protobacterias y bacterias esporulantes). El estudio de los copépodos, tuvo como objetivo identificar a la comunidad de copépodos larvívoros que se desarrolla en los criaderos de mosquitos, ubicados en los alrededores de la ciudad de La Plata, para identificar nuevas especies capaces de depredar mosquitos que habitan recipientes artificiales (A. aegypti y C. pipiens). La diversidad de copépodos larvívoros fue mayor en los cuerpos de agua permanentes. Acanthocyclops robustus, Diacyclops uruguayensis, Macrocyclops albidus y Mesocyclops longisetus fueron seleccionados por su capacidad depredadora. En el laboratorio fueron evaluadas: la capacidad de depredación de ambos sexos y diferentes estadios, preferencia de especie presa, y la tasa de depredación diaria. Las hembras de estas especies de copépodos presentaron mayor capacidad depredadora. No se detectó preferencia de los copépodos hacia ninguna de las especies de mosquitos. También se evaluó la tolerancia a la desecación y la capacidad de vivir en el agua que se acumula en los recipientes artificiales. Diacyclops uruguayensis y A. robustus sobrevivieron en las condiciones de sequía ensayadas en este estudio, pero D. uruguayensis mostró una menor supervivencia en el agua de recipientes artificiales. Macrocyclops albidus no sobrevivió en condiciones de sequía ni toleró el agua extraída de los recipientes artificiales. La supervivencia de M. longisetus ante estas condiciones, fue reducida. Se concluyó que las especies D. uruguayensis y A. robustus podrían ser buenos candidatos para el control de especies de mosquitos que crían en recipientes artificiales.

Continuous, transcutaneous carbon-dioxide monitoring to avoid hypercapnia in complex catheter ablations under conscious sedation

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
K Weinmann ◽  
A Lenz ◽  
R Heudorfer ◽  
D Aktolga ◽  
M Rattka ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Conscious Sedation ◽  
Venous Blood ◽  
Patient Comfort ◽  
Carbon Dioxide Partial Pressure ◽  
Close Monitoring ◽  
Blood Gas ◽  
Transcutaneous Carbon Dioxide ◽  
The Difference ◽  
Venous Blood Gas

Abstract Background Ablation of complex cardiac arrhythmias requires an immobilized patient. For a successful and safe intervention and for patient comfort, this can be achieved by conscious sedation. Administered sedatives and analgesics have respiratory depressant side effects and require close monitoring. Purpose We investigated the feasibility and accuracy of an additional, continuous transcutaneous carbon-dioxide partial pressure (tpCO2) measurement during conscious sedation in complex electrophysiological catheter ablation procedures. Methods We evaluated the accuracy and additional value of tpCO2 detection by application of a Severinghaus electrode in comparison to arterial and venous blood gas analyses. Results We included 110 patients in this prospective observational study. Arterial pCO2 (paCO2) and tpCO2 showed good correlation throughout the procedures (r=0.60–0.87, p<0.005). Venous pCO2 (pvCO2) were also well correlated to transcutaneous values (r=0.65–0.85, p<0.0001). Analyses of the difference of pvCO2 and tpCO2 measurements showed a tolerance within <10mmHg in up to 96–98% of patients. Hypercapnia (pCO2<70mmHg) was detected more likely and earlier by continuous tpCO2 monitoring compared to half-hourly pvCO2 measurements. Conclusion Continuous tpCO2 monitoring is feasible and precise with good correlation to arterial and venous blood gas carbon-dioxide analysis during complex catheter ablations under conscious sedation and may contribute to additional safety. Funding Acknowledgement Type of funding source: None

A New Equal Area Method to Calculate and Represent Physiologic, Anatomical, and Alveolar Dead Spaces

2006 ◽  
Vol 104 (4) ◽  
pp. 696-700 ◽  
Author(s):  
Yongquan Tang ◽  
Martin J. Turner ◽  
A Barry Baker
Keyword(s):  
Carbon Dioxide ◽  
Dead Space ◽  
Graphical Method ◽  
Mean Difference ◽  
Equal Area ◽  
Area Method ◽  
Physiologic Dead Space ◽  
Anatomical Dead Space ◽  
The Mean ◽  
The Difference

Background Physiologic dead space is usually estimated by the Bohr-Enghoff equation or the Fletcher method. Alveolar dead space is calculated as the difference between anatomical dead space estimated by the Fowler equal area method and physiologic dead space. This study introduces a graphical method that uses similar principles for measuring and displaying anatomical, physiologic, and alveolar dead spaces. Methods A new graphical equal area method for estimating physiologic dead space is derived. Physiologic dead spaces of 1,200 carbon dioxide expirograms obtained from 10 ventilated patients were calculated by the Bohr-Enghoff equation, the Fletcher area method, and the new graphical equal area method and were compared by Bland-Altman analysis. Dead space was varied by varying tidal volume, end-expiratory pressure, inspiratory-to-expiratory ratio, and inspiratory hold in each patient. Results The new graphical equal area method for calculating physiologic dead space is shown analytically to be identical to the Bohr-Enghoff calculation. The mean difference (limits of agreement) between the physiologic dead spaces calculated by the new equal area method and Bohr-Enghoff equation was -0.07 ml (-1.27 to 1.13 ml). The mean difference between new equal area method and the Fletcher area method was -0.09 ml (-1.52 to 1.34 ml). Conclusions The authors' equal area method for calculating, displaying, and visualizing physiologic dead space is easy to understand and yields the same results as the classic Bohr-Enghoff equation and Fletcher area method. All three dead spaces--physiologic, anatomical, and alveolar--together with their relations to expired volume, can be displayed conveniently on the x-axis of a carbon dioxide expirogram.

Decreased Carbon Dioxide Sensitivity in Infants of Substance-Abusing Mothers

PEDIATRICS ◽  
1995 ◽  
Vol 95 (6) ◽  
pp. 864-867
Author(s):  
Janet G. Wingkun ◽  
Janet S. Knisely ◽  
Sidney H. Schnoll ◽  
Gary R. Gutcher
Keyword(s):  
Carbon Dioxide ◽  
Tidal Volume ◽  
Minute Ventilation ◽  
Demographic Data ◽  
Substance Abusing ◽  
Quiet Sleep ◽  
Co2 Level ◽  
The Difference ◽  
End Tidal ◽  
Drug Free

Objective. To determine whether there is a demonstrable abnormality in control of breathing in infants of substance-abusing mothers during the first few days of life. Methods. We enrolled 12 drug-free control infants and 12 infants of substance abusing mothers (ISAMs). These infants experienced otherwise uncomplicated term pregnancies and deliveries. The infants were assigned to a group based on the results of maternal histories and maternal and infant urine toxicology screens. Studies were performed during quiet sleep during the first few days of life. We measured heart rate, oxygen saturations via a pulse oximeter, end-tidal carbon dioxide (ET-CO2) level, respiratory rate, tidal volume, and airflow. The chemoreceptor response was assessed by measuring minute ventilation and the ET-CO2 level after 5 minutes of breathing either room air or 4% carbon dioxide. Results. The gestational ages by obstetrical dating and examination of the infants were not different, although birth weights and birth lengths were lower in the group of ISAMs. Other demographic data were not different, and there were no differences in the infants' median ages at the time of study or in maternal use of tobacco and alcohol. The two groups had comparable baseline (room air) ET-CO2 levels, respiratory rates, tidal volumes, and minute ventilation. When compared with the group of ISAMs, the drug-free group had markedly increased tidal volume and minute ventilation on exposure to 4% carbon dioxide. These increases accounted for the difference in sensitivity to carbon dioxide, calculated as the change in minute ventilation per unit change in ET-CO2 (milliliters per kg/min per mm Hg). The sensitivity to carbon dioxide of control infants was 48.66 ± 7.14 (mean ± SE), whereas that of ISAMs was 16.28 ± 3.14. Conclusions. These data suggest that ISAMs are relatively insensitive to challenge by carbon dioxide during the first few days of life. We speculate that this reflects an impairment of the chemoreceptor response.

Functional validation of the carbon dioxide receptor genes in Aedes aegypti mosquitoes using RNA interference

2011 ◽  
Vol 21 (1) ◽  
pp. 119-127 ◽  
Author(s):  
C. N. G. Erdelyan ◽  
T. H. Mahood ◽  
T. S. Y. Bader ◽  
S. Whyard
Keyword(s):  
Carbon Dioxide ◽  
Rna Interference ◽  
Aedes Aegypti ◽  
Functional Validation

scholarly journals Cloning and Expression of Two Crystal Protein Genes, cry30Ba1 and cry44Aa1, Obtained from a Highly Mosquitocidal Strain, Bacillus thuringiensis subsp. entomocidus INA288

2006 ◽  
Vol 72 (8) ◽  
pp. 5673-5676 ◽  
Author(s):  
Takeshi Ito ◽  
Tomonori Ikeya ◽  
Ken Sahara ◽  
Hisanori Bando ◽  
Shin-ichiro Asano
Keyword(s):  
Bacillus Thuringiensis ◽  
Aedes Aegypti ◽  
Culex Pipiens ◽  
Crystal Protein ◽  
Cloning And Expression ◽  
Culex Pipiens Pallens ◽  
Bacillus Thuringiensis Subsp ◽  
Pipiens Pallens ◽  
Crystal Protein Genes

ABSTRACT Two novel crystal protein genes, cry30Ba and cry44Aa, were cloned from Bacillus thuringiensis subsp. entomocidus INA288 and expressed in an acrystalliferous strain. Cry44Aa crystals were highly toxic to second-instar Culex pipiens pallens (50% mortality concentration [LC50] = 6 ng/ml) and Aedes aegypti (LC50 = 12 ng/ml); however, Cry30Ba crystals were not toxic.

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