Fine structure of the synganglion of unfed female Rhipicephalus (Rhipicephalus) sanguineus (Latreille) (Ixodoidea: Ixodidae).

The synganglion of unfed female Rhipicephalus (Rhipicephalus) sanguineus (Latreille) is enclosed within a well defined neural lamella underlined by the perineurium. No organelles were observed in the neural lamella, whereas axons containing neurosecretory vesicles, tracheal elements and glycogen deposits are visible in the perineurium. Below the perineurium, a cortical layer of nervous and non-nervous elements surrounds an inner neuropile, the latter is enclosed by a thin subperineurial layer. The neuropile is formed of nerve fibers containing neurotubules.

Genital system structure of unfed female Rhipicephalus (Rhipicephalus) sanguineus (Latreille) (Ixodoidea: Ixodidae).

The reproductive system of female Rhipicephalus sanguineus consists of a single ovary, paired oviducts fusing into a single common oviduct, connecting tube, the vagina that in turn divides into cervical and vestibular regions, a wide receptaculum seminis and tubular accessory glands that open into the vagina between the cervical and vestibular regions. The histological structure of each part of the female reproductive system is described. The fine structure of the ovary, connecting tube and accessory glands is also provided in this study.

Effects of permethrin on the salivary glands and neuroendocrine organs of unfed female Hyalomma (Hyalomma) dromedarii (Ixodoidea: Ixodidae).

Permethrin-impregnated fabric has been shown to be an effective repellent against various tick species. However, some tick species are not repelled by this chemical. In Hyalomma dromedarii (Koch), permethrin exposure is reported to actually enhance the tick's attachment behavior. This study evaluated the histological effects of permethrin exposure on the salivary glands and neuroendocrine organs of unfed, virgin H. dromedarii ticks of uniform age. Three fabric treatments consisting of unwashed-untreated (control), washed after treatment (0.125 mg [AI] / cm2) and unwashed-treated were used after 5- and 10-min exposure times for unfed, unmated females. For all of the organs examined, the cellular structure of treated ticks differed from controls as evidenced by increases in cellular activity, as well as significant increases in the size of the cells of the organs under study (P < 0.05). These data conclusively demonstrate that an unexpected enhanced attachment response observed in this tick species after permethrin exposure is the direct result of increased neurosecretory and salivary gland activity induced by that exposure.

Effect of 25-azacholestane on Argas (Argas) hermanni (Ixodoidea:Argasidae).

Unfed and fed nymphal Argas hermanni Audouin were treated topically with 1, 5, 10, 15, and 20 micrograms of 25-azacholestane. The azasteroid did not inhibit feeding but had a dose-related lethal effect on unfed nymphs. Generally, it had little effect on nymphs treated after feeding. The 10-micrograms dose reduced the premolting period of nymphs treated before feeding. Some adults emerging from the 5- to 20-micrograms dosage groups that had been treated before feeding failed to shed their exuvia and others also had deformed legs. Greater numbers of adult females emerged from nymphs treated before feeding. The preoviposition period was almost the same in control females and of female mates, with males emerging from treated nymphs. Females from nymphs treated before feeding have a prolonged preoviposition period. Fecundity was reduced when males were treated with 10-20 micrograms as unfed nymphs. Egg hatch was reduced for females treated with 15 and 20 micrograms as fed nymphs, females treated with 5 and 10 micrograms as unfed nymphs, and as progeny of males treated with 10 micrograms as unfed nymphs. Results suggest possible interference with juvenile hormone titer in treated ticks.

Biochemical changes in the coxal organ proper and accessory glands of female Ornithodoros (Ornithodoros) savignyi at different physiological conditions.

Changes in the total protein, DNA, RNA, lipid and phospholipid concentrations in the coxal organ proper and accessory glands of Ornithodoros (Ornithodoros) savignyi (Audouin) were studied. There was an increase in the total protein, DNA, RNA, lipid and phospholipid content of the coxal organ proper in the female upto 6-days after feeding, then the concentration decreased. Also, the content of protein, DNA, RNA, lipid and phospholipid in the coxal organ proper of the seventh nymphal instar were similar to unfed females. Accessory glands showed an increase in protein, DNA, RNA, lipid and phospholipid content that reached its maximum on day 8 after feeding in females, then decreased.

Structural changes of the diaphragmatic peritoneum in patients with schistosomal hepatic fibrosis: its relation to ascites.

The histopathologic changes of the peritoneum of the hemidiaphragm were studied in 30 patients with schistosomal liver disease and compared with ten control subjects. The diaphragmatic peritoneum of patients with ascites was markedly thickened with infiltration of inflammatory cells and collagen bundles resembling the interstitial changes of peripheral lymphedema. Obliteration of diaphragmatic lymphatic stomata with restricted lymph flow as well as excess lymph formation from portal hypertension are both major factors in the magnitude and intractability of ascites associated with schistosomal hepatic fibrosis.