The subgenusPersicargas (Ixodoidea: Argasidae:Argas). 36. Structure and postembryonic development of the neurohemal organ inA. (P.) arboreus

The structure and postembryonic development of the paraesophageal neurohemal organ lying posteriad to the central nerve mass ofArgas (Persicargas) arboreus are described and compared with other arthropod neurohemal-endocrine organs. During postembryonic development, a few large cells differentiate in the larval esophageal epithelium and gradually multiply to form a compact cell mass. In the first nymphal instar, cell mass evagination forms the dorsal lobe of the neurohemal organ which develops in the second instar and attains its final lobular structure in the third instar. These observations provide evidence for homology to the insect corpora cardiaca and related organs in other arthropods.Request offprints from Medical Zoology Department, NAMRU-3, FPO, New York 09527, USAFrom Research Project MR041.05.01-0067, Naval Medical Research and Development Command, National Naval Medical Center, Bethesda, Maryland, USA. The opinions and assertions contained herein are the private ones of the authors and are not to be construed as official or as reflecting the views of the Department of the Navy or of the naval service at large.     

The subgenusPersicargas (ixodoidea: Argasidae:Argas). 35. The lateral segmental organs and peritracheal gland in immature and adultA. (P.) arboreus

Lateral segmental organs and a peritracheal gland in adult and immatureArgas (Persicargas) arboreus are described and compared with similar organs in other arthropods. Four pairs of lateral segmental organs containing neuronal cell bodies and innervated by branches of hemal nerves from pedal nerve roots are present in nymphal instars and in the adult; 3 pairs are present in the larva. In each postembryonic developmental stage, the peritracheal gland consists of cell masses with neurosecretory granular activity and is associated with the tracheal plexus in the region of the central nerve mass and adjacent hypodermis. The glandular cells show cyclic changes in size and activity related to the molting process in immature stages and probably to other events in the adult.Request offprints from Medical Zoology Department, NAMRU-3, FPO, New York 09527, USAFrom Research Project MR041.05.01-0067, Naval Medical Research and Development Command, National Naval Medical Center, Bethesda, Maryland, USA. The opinions and assertions contained herein are the private ones of the authors and are not to be construed as official or as reflecting the views of the Department of the Navy or of the naval service at large     

Bionomics and health importance of fowl tickArgas (Persicargas) persicus (Oken, 1818) (Ixodoidea: Argasidae)

The fowl tickArgas (Persicargas) persicus occurs in warm areas of Slovakia, where its distribution is limited by the 650–700 mm annual average isohyet and the +8° C annual average isotherm. In Slovakia, larvae hatch from spring to autumn, and nymphal and adult moultings occur chiefly in July and August. Larvae feed for four days, nymphs and adults for less than one hour. The tick develops and reproduces during the warm season in the wild but throughout the year under favourable laboratory conditions in which the life cycle requires 17 months.     

Effect of ivermectin on the integument and dorsoventral muscles of the tick Argas (Persicargas) persicus (Oken) (Ixodoidea: Argasidae)

Light and transmission electron microscopy (TEM) revealed that integument of Argas persicus consisted of cuticle underlined with epidermal cells. Cuticle consisted of outer epicuticle and inner procuticle. Epicuticle is further subdivided into thin wax, thin electron dense cuticulin, and thick less electron dense protein epicuticle layers. The procuticle consisted of exo-, endo-, and subcuticle. The procuticle contained numerous pore canals emerged from epidermal cells. Dermal glands were scattered between epidermal cells. TEM showed that each muscle cell contained two types of myofilaments and numerous electron dense bodies. Cytoplasmic organelles are peripherally located and plasma lemma invaginated deeply forming sarcotubular system. Feeding resulted in marked increase in cytoplasmic organelles and secretions of both epidermal cells and dermal glands. It also led to stretching of myofilaments, proliferation of cytoplasmic organelles, and appearance of glycogen particles in muscle cells. Subcutaneous inoculation of ivermectin (IVM) at a dose of 400 μg/kg pigeon resulted in extensive alterations in the integument and muscle cells. Both exhibited intense vacuolation of the cytoplasm, damage of cytoplasmic organelles, and swelling of the nucleus. It also caused aggregation of pore canals in the procuticle, depletion of secretory vesicles in dermal gland cells, and destruction of myofilaments, dense bodies, and sarcotubular system in muscle cells. The results suggest that IVM probably binds to the neurotransmitters or the hormones involved in secretion processes of epidermal cells and dermal glands in the integument or those involved in contraction of dorsoventral muscles.     

Effect of low-dose gamma radiation on nuclear RNA-polymerase activity and protein synthesis in liver cells of different-age chicks

The effect of low-dose (0.05 Gy) gamma irradiation of chicks in the preincubation period on subsequent liver cell RNA-polymerase activity and protein synthesis is studied at different ages. It is shown that irradiated chicks demonstrate an increased level of RNA-polymerase and increased incorporation of labeled amino acids into cytoplasmic proteins. Apparently, low-dose ionizing radiation induces activation of the liver cell genome, this being one of the main mechanisms of the general stimulatory effect of low doses. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, No 3, pp. 286–288, March, 1995     

Argas (Argas) monolakensis, new species (Acari: Ixodoidea: Argasidae), a parasite of California gulls on islands in Mono Lake, California: description, biology, and life cycle.

Argas (Argas) monolakensis, n. sp., is described from adults, nymphs, and larvae collected from under and around nests of California gulls, Larus californicus Lawrence, on islands in Mono Lake, Mono County, Calif., and from specimens reared in the laboratory. This species is closely related to A. cooleyi Kohls & Hoogstraal, a parasite of cliff swallows, Hirundo pyrrhonota Vieillot, but is easily distinguished by hypostome dentition and roof of Haller's organ in all stages and chaetotaxy of the larvae. This tick was successfully reared and maintained in the laboratory by feeding them on domestic chickens. Larvae require 5-8 d to feed, whereas all postlarval stages feed rapidly within 9-62 min. At Mono Lake, ticks are above ground and seek hosts only at night. The number of nymphal stages varies from 2 to 5 depending on the developmental temperature and sex of the tick. Ticks over winter at Mono Lake as second- to fifth-stage nymphs and adults. Ovarian diapause is common with preoviposition periods in extreme cases lasting up to 20 mo. This tick will readily feed on humans and has the potential to transmit Mono Lake virus, which has been isolated from an estimated 2-8% of ticks on various islands. To date, A. monolakensis is known only from islands in Mono Lake, Calif.     

Effect of triterpene acids of Eriobotrya japonica (Thunb.) Lindl. leaf on inflammatory cytokine and mediator induction from alveolar macrophages of chronic bronchitic rats

Objective: The study was to evaluate the effect of triterpene acids of Eriobotrya japonica (thunb.) lindl. leaf (TAL) on inflammatory cytokine and mediator expression in alveolar macrophages (AM) of chronic bronchitic (CB) rats. Methods: CB was induced by endotracheal instillation of lipopolysaccharide (LPS) followed by Bacillus Calmette Guerin (BCG) injection via the caudal vein one week later. Treatment groups received TAL at there different doses (50, 150, or 450 mg/kg daily i. g.), Ketotifen fumarate (5 mg/kg daily i. g.) or dexamethasone (1.2 mg/kg daily i. g.) for two weeks, 7 days after LPS injection. AM were then isolated and incubated for 24 h. IL-1, TNF-α and PGE2 levels in cultured supernatants were measured by thymocyte co-stimulating assay and radioimmunoassay. Immunocytochemistry staining and western-blot were used for intracellular location and activation of p65 subunit of NF-kB. LTB₄ level was analyzed by reverse-phase high performance liquid chromatography (RP-HPLC). Results: The levels of TNF-α, IL-1, NF-kB, PGE2 and LTB₄ expression in AM of TAL groups were significantly decreased compared to the CB group (P < 0.05 or P < 0.01), in a dose dependent manner. Conclusion: TAL inhibited NF-kB activation in AM from CB rats and led to down regulation of TNF-α, IL-1, PGE₂ and LTB₄ expression, which might be a mechanism for its anti-inflammatory effects in CB rats. Received 17 November 2005; returned for revision 19 March 2006; returned for final revision 14 July 2006; accepted by G. Wallace 30 August 2006     

Effect of pulsed infrared laser radiation on DNA synthesis in tissues of intact rats and during strenuous physical exercise

The motor zone of the rat brain cortex is subjected to pulsed infrared (0.89 μ) laser radiation, which is found to stimulate DNA synthesis both in intact animals and after strenuous physical exercise (swimming). Preliminary laser irradiation exerts a stress-limiting effect on cells of the brain cortex and thymus but does not prevent swimminginduced reduction of³H-thymidine incorporation in nuclear DNA of muscles. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 6, pp. 625–627, June, 1995 Presented by V. M. Bogolyubov, Member of the Russian Academy of Medical Sciences     

Effect of the (3–4) fragment of substance P on brain ischemia in rats with different types of behavior

A single administration of a fragment of substance P 30 min after ligation of the common carotid arteries increases resistance to brain ischemia primarily in rats with a passive type of behavior (improves their neurological status and prevents posthypoxic hyperactivity), prevents posthypoxic hyperactivity in rats with an intermediate type of behavior, and lowers the resistance of rats with an active type of behavior (increases their mortality and aggravates their neurological status). Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 121, No. 4, pp. 399–403, April, 1996 Presented by P. V. Simonov, Member of the Russian Academy of Medical Sciences