Prevalence and predictors of persistent sinus rhythm after elective electrical cardioversion for atrial fibrillation.

Aims: To evaluate the prevalence and predictors of persistent sinus rhythm in a recent cohort of unselected patients undergoing electrical cardioversion for atrial fibrillation.

Methods: We enrolled all consecutive patients undergoing elective electrical cardioversion for atrial fibrillation between January 2017 and December 2018. We analysed baseline clinical and echocardiographic data as well as pharmacological antiarrhythmic therapy.

Effects of a new insect growth regulator, CGA-255'728, on the different stages of the cat flea (Siphonaptera: Pulicidae).

A new juvenile hormone mimic CCA-255'728, developed by Novartis, was tested for its efficacy on different life stages of the cat flea, Ctenocephalides felis (Bouché). The compound was mixed in bovine blood at concentrations of 1, 10, and 100 ppb and fed to adult fleas using an artificial membrane system. Less than 7% of the eggs from fleas fed 10 and 100 ppb hatched, compared with >70% hatch in eggs laid by control fleas or fleas fed 1 ppb.

Comparative evaluation of juvenoids for control of cat fleas (Siphonaptera: Pulicidae) in topsoil.

The efficacy of a photostable formulation of methoprene and two photostable juvenoids, fenoxycarb and pyriproxyfen, and their residual activity in inhibiting the emergence of adult cat fleas, Ctenocephalides felis (Bouché), was studied in topsoil. Nursery pots composed of clay, peat, and plastic, and wooden flats were used to hold soil samples. Treated soil samples were exposed to sunlight during the 63-d study period.

Factors influencing sperm transfer and insemination in cat fleas (Siphonaptera: Pulicidae) fed on an artificial membrane system.

Sperm transfer through the epididymis, a prerequisite for insemination of cat fleas, Ctenocephalides felis (Bouché) was stimulated by exposure of unfed male fleas to juvenile hormone III residues for 3 d at 25 degrees C or exposure of unfed fleas to 37 degrees C for 6 d. Sperm transfer was completed at least three times faster in unfed males held at 37 degrees C than in those held at 25 degrees C. Although percentage sperm transfer in fleas fed water or 0.

Effect of diet composition on weight gain, sperm transfer, and insemination in the cat flea (Siphonaptera: Pulicidae).

Weight gain by adult cat fleas, Ctenocephalidesfelis (Bouché), was influenced primarily by the concentrations of protein and sodium chloride in the feeding solution. After 48 h of feeding, fleas fed whole blood weighed almost twice as much as fleas fed plasma or hemolyzed blood and 1.25 times as much as fleas fed 0.

Effects of juvenile hormone on eggs and adults of the cat flea (Siphonaptera: Pulicidae).

Juvenile hormone III plays a major role in regulating feeding and reproduction in the adult cat flea, Ctenocephalides felis (Bouché). Both blood consumption and egg production increased in a dose-dependent manner up to a maximum at 1,250 ppm when fleas were continuously exposed to concentrations up to 12,500 ppm juvenile hormone. Histological studies demonstrated that juvenile hormone III also stimulated cellular differentiation of salivary gland epithelia, midgut epithelia, and fat body cells, enhancing the ability of the adult flea to digest blood and synthesize vitellogenins for the maturing oocytes.

Effect of pyriproxyfen in the blood diet of cat fleas on adult survival, egg viability, and larval development.

The activity of pyriproxyfen in the blood diet was investigated for its efficacy against adult, egg, and larval stages of the cat flea, Ctenocephalides felis (Bouché). Adult fleas were housed in plastic cages and fed treated bovine blood using an artificial membrane system that allows fleas to feed ad libitum through a parafilm membrane. Control fleas received blood without pyriproxyfen.

Ultrastructural analysis of neurosecretory cells in the antennae of the mosquito, Culex salinarius (Diptera: Culicidae).

An antiserum raised against the peptide, culetachykinin II, immunocytochemically detected a group of neurosecretory cells in the first flagellar segment of the antennae of both males and females of the mosquito, Culex salinarius. This is the first insect species in which neurosecretory cells have been found in the antennae. The ultrastructure of these antennal neurosecretory cells (ANC) is described, as well as their relationship to other neurons in the antennae and antennal lobe of the mosquito.

Mode of action of lufenuron in adult Ctenocephalides felis (Siphonaptera: Pulicidae).

When cat fleas, Ctenocephalides felis (Bouché), were fed concentrations of lufenuron in cattle blood ranging from 0.5 to 4 ppm, adult mortality increased in a dose-dependent manner to a maximum of approximately 24% over a period of 10 d. Fleas treated with 0.

Juvenile hormone biosynthesis in diapausing and nondiapausing Culex pipiens (Diptera: Culicidae).

The synthesis of juvenile hormone in vitro by diapausing and nondiapausing Culex pipiens L. was measured by radiochemical assay. Paired corpora allata from diapausing females synthesized < 18 fmols of juvenile hormone per hour during the first 3 wk after emergence.

Chorion formation and ultrastructure of the egg of the cat flea (Siphonaptera: Pulicidae).

Oocyte development in adult female cat fleas, Ctenocephalides felis (Bouché), was studied by light and electron microscopy to determine the formation and ultrastructural morphology of the eggshell. As oocytes develop, somatic follicle cells from the lining of the ovariole migrate around the oocytes. The follicle cells produce electron-dense granules that form the vitelline membrane around the developing oocyte.

Effect of lufenuron on chorionic and cuticular structure of unhatched larval Ctenocephalides felis (Siphonaptera: Pulicidae).

When adult cat fleas, Ctenocephalides felis (Bouché), were fed concentrations of < or = 0.08 ppm lufenuron in cattle blood, egg hatch did not differ significantly from the controls. However, as the concentration of lufenuron in blood increased from 0.

Mode of action of lufenuron on larval cat fleas (Siphonaptera: Pulicidae).

Adult cat fleas, Ctenocephalides felis (Bouché), were fed suboptimal in vitro concentrations of lufenuron in blood to allow hatching of flea larvae for cytological study. At concentrations of 0.125, 0.

Effect of juvenile hormone and juvenile hormone mimics on sperm transfer from the testes of the male cat flea (Siphonaptera:Pulicidae).

Sperm transfer into the epididymis was completed without a blood meal, when newly emerged male cat fleas. Ctenocephalides felis (Bouché), were exposed to filter papers treated with juvenile hormone III or the juvenile hormone mimics fenoxycarb, methoprene, or pyriproxyfen. As the concentration of juvenile hormone or the time of flea exposure to juvenile hormone or the juvenile hormone mimics increased, the percentage of fleas that transferred sperm also increased.

Pyriproxyfen effects on newly engorged larvae and nymphs of the lone star tick (Acari:Ixodidae).

Newly engorged larvae and nymphs of the lone star tick, Amblyomma americanum (L.), were exposed to 9 treatments of pyriproxyfen in glass vials consisting of dosages of 4, 8, and 16 micrograms/cm2 for 7 d, 14 d, and continuous exposure periods at each concentration. Treatment of newly engorged larvae resulted in decreased molting, altered postmolt defecation, and nymphal survival with results being dose and exposure dependent.

Effects of pyriproxyfen on engorged females and newly oviposited eggs of the lone star tick (Acari:Ixodidae).

Engorged females and 1- to 3-d-old eggs of the lone star tick, Amblyomma americanum (L), were exposed to 9 treatments of pyriproxyfen (4, 8, and 16 micrograms/cm2) in glass vials at exposure periods of 7 d, 14 d, and continuous at each dosage level. Treatment of newly engorged females did not affect the number of females ovipositing, but the number of eggs oviposited decreased as dosage and exposure time increased. Complete inhibition of egg hatch occurred at all treatment levels except that of the lowest dosage and exposure time where 99.

Toxicity and histopathology of the growth regulator pyriproxyfen to adults and eggs of the cat flea (Siphonaptera:Pulicidae).

Adult cat fleas, Ctenocephalides felis (Bouché), exposed continuously to pyriproxyfen died within 8-10 d. Microscopic examination of 7-d-old adults indicated death was caused by histopathological damage to fat body, Malpighian tubules, midgut epithelia, salivary gland cells, and other internal tissues. Fleas were killed by pyriproxyfen regardless of whether they were held as unfed adults on treated filter paper or as feeding adults on treated dog hair.

Survival and reproduction of the cat flea (Siphonaptera: Pulicidae) fed human blood on an artificial membrane system.

Adult cat fleas, Ctenocephalides felis (Bouché), survive and reproduce when fed human blood through an artificial membrane system. When a dog hair substrate was included in cages with the fleas, mean adult mortality was 2.4 after 12 d of bloodfeeding.

Mode of action of pyriproxyfen and methoprene on eggs of Ctenocephalides felis (Siphonaptera: Pulicidae).

Adult cat fleas were exposed to residues of pyriproxyfen and methoprene in glass vials, then fed on a cat 24 h later to investigate the mode of action of juvenoid growth regulators on embryonic development in flea eggs. Eggs laid by pyriproxyfen-treated fleas within 70 h after exposure to this juvenoid were often devoid of yolk and frequently collapsed after oviposition. Minimal amounts of yolk were deposited in eggs laid after 70 h, and no blastoderm was formed.

Field evaluation of Nylar for control of cat fleas (Siphonaptera: Pulicidae) in home yards.

Procedures were developed to evaluate juvenoid insect growth regulators in home yards as part of an ongoing program to identify photostable insecticides for control of the cat flea, Ctenocephalides felis (Bouché). Nylar, an emulsifiable concentrate formulation of pyriproxyfen, was selected as the experimental insect growth regulator. Efficacy studies, yard survey, and pretreatment sampling techniques are described.

Autogeny in Culex salinarius from Texas, Florida and New Jersey.

Autogeny was studied in Culex salinarius from College Station, Texas; Vero Beach, Florida; and Edison and Dennisville, New Jersey. Autogenous egg development varied from 14% in the Florida colony to 23 and 27%, respectively, in colonies from Texas and New Jersey. The mean number of eggs per autogenous female ranged from 13.

Assessment of six benzyl-1,3-benzodioxole compounds for anti-juvenile hormone activity in Culex pipiens.

Fourth instar larvae of Culex pipiens were exposed to six benzyl-1,3-benzodioxole derivatives to assess the effectiveness of these compounds as anti-juvenile hormone agents. Mortality ranging from between 18 and 99% was observed in larvae and early pupae but the surviving adults showed no clearly defined anti-juvenile hormone effects. Adult effects included a reduction in number of eggs developed and the presence of degenerating eggs 4 days after the blood meal.

Juvenile hormone induction of biting behavior in culex mosquitoes.

Juvenile hormone deprivation caused by surgical removal of corpora allata shortly after adult emergence blocked the initiation of biting behavior in Culex. pipiens and Culex quinquefasciatus. Reimplantation of corpora allata or injection of a synthetic juvenile hormone (JH-I) corrected the juvenile hormone deficiency and restored biting behavior.