The insecticide chlorpyrifos (CPF) is widely used in the Kingdom of Saudi Arabia (KSA) to control agricultural pests. The present work is a preliminary investigation of the effect of CPF on healing of cutaneous leishmaniasis (CL) lesions, caused by Leishmania major in farmers exposed to this insecticide, after treatment with Pentostam®. Lesion diameters were measured and CPF concentrations in the blood plasma of farmer and non-farmer CL patients in Al-Ahsa were detected by gas chromatography/mass spectrometry/mass spectrometry before and 6 weeks after treatment with Pentostam®. CPF concentrations in the blood of farmer patients ranged between 4.570 and 7.096ng/μl (mean=6.19±0.881ng/μl) before and after treatment with Pentostam®. The mean lesion diameter in these patients decreased by a factor of 2.21 after treatment with Pentostam®; they measured 1.85–11.75mm, (mean=6.165±3.500mm) before treatment and 0.22–6.10mm (mean=2.796±2.102mm) after treatment. Lesion diameter increased exponentially with the increase of CPF concentration in the patients’ blood. CPF was not detected in the non-farmer patients before or after treatment. Their mean lesion diameter decreased by a factor of 6.86 after treatment with Pentostam®; they measured 1.33–7.10mm (mean=2.882±1.764mm) before treatment and 0.11–0.92mm (mean=0.425±0.277mm) after treatment. The mean lesion diameter in farmer patients was much greater than that of non-farmer patients both before (2.14×) and after (6.657×) treatment with Pentostam®. Chronic exposure to low levels of the pesticide aggravates the development and delays the healing of CL lesions due to immunotoxicity and/or peripheral neurotoxicity caused by CPF. Further detailed studies would assess CPF effect on the severity of infection with CL in agricultural workers continuously exposed to this insecticide in different areas of KSA in conformity of their finding.

Three groups of BALB/c mice were treated orally with 0.6, 1.0 and 6.0mg/kg body weight of chlorpyrifos (CPF), and 3 other groups were treated with 2.5, 6.25 and 25mg/kg bodyweight of alphacypermethrin (ACM), respectively, every other day for 1 week. Six other groups were treated similarly for 2 weeks. The treated groups and a control group for each pesticide were inoculated in the dorsum with Leishmania major promastigotes at their stationary phase. Lesions started to appear 2-3 weeks post-inoculation and their diameters were measured in all groups 1, 5, 9 and 14 days post-appearance (PA). The mean diameter of lesions (MDL) only in the 6.0mg group treated with CPF for 1 week was larger than that of the control group. In the groups treated for 2 weeks, the MDL of the 1.0 and 6.0mg groups were larger than those of the control group 5, 9 and 14 days PA while MLD of the 0.6mg group was larger than that of the control group only 5 days PA. MLD was larger in the 0.6mg group treated for 2 weeks than that in the group treated for 1 week 1 and 5 days PA. MLD was larger in the 1.0mg group treated for 2 weeks than that treated for 1 week 9 days PA. MLD was similar in the 6.0mg group treated for 1 and 2 weeks. The MDL only in the 25mg group treated with ACM for 1 week was larger than that of the control group 9 and 14 days PA. The MDL of the 6.25 and 25mg groups treated for 2 weeks were larger than those of the control groups 5 days PA and the MLD of the 25mg group was larger than that of the control group 9 and 14 days PA. The MLD was larger in the 2.5mg group treated for 2 weeks than that in the group treated for 1 week 5 days PA. The MLD was larger in the 6.25 and 25.0mg groups treated for 2 weeks than those treated for 1 week 1 and 5 days PA. Immunotoxicity and/or peripheral neurotoxicity caused by CPF and ACM might have caused aggravation of lesions in mice particularly those treated with the pesticides for 2 weeks.

OBJECTIVE:To determine tick viruses transmissible to man in Saudi Arabia. METHODS:We collected tick samples for identification from different region of Saudi Arabia during March 1992 - December 1992. Ticks collected from domestic animals were washed with buffer containing antibiotics, macerated, triturated in minimal essential media (MEM), centrifuged and the supernatant inoculated intracerebrally in suckling mice. Brains of mice showing disease signs were similarly treated and the supernatant inoculated on cell cultures. Antigen spot slides were prepared from material of blind-passed cell cultures showing cytopathic effects. The slides were overlaid by group-specific hyperimmune mouse ascetic fluid (HMAF) to different virus groups and stained with antimouse fluorescein isothiocyanate conjugate. Positive slides were retested with monoclonal antibodies or HMAF to individual viruses within the positive group. RESULTS:Sindbis virus was isolated from Hyalomma dromedarii (H. dromedarii) from Al-Qasim and Jazan regions and Hyalomma impeltatum (H. impeltatum) from Al-Qasim, Ar-Riyadh and Jazan regions. Chick Ross and Kadam viruses were isolated from H. dromedarii from Al-Qasim region. Kadam virus was isolated from Hyalomma anatolicum (H. anatolicum) from Ar-Riyadh region. Dhori virus was isolated from H. impeltatum and Hyalomma schulzei (H. schulzei) from the Eastern region. Other alphaviruses were isolated from H. dromedarii from Al-Qasim and Tabuk regions, H. impeltatum from Jazan region, H. anatolicum from the Eastern region and Rhipicephalus sanguineus from Ar-Riyadh and Eastern regions. CONCLUSION:In the Kingdom, ticks harbor viral infections transmissible from wildlife to man and his livestock. Local physicians should be aware of the symptoms and signs of these infections.

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.

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.

Protein and nucleic acid levels from the ovaries of Hyalomma dromedarii Koch were determined during different stages of oogenesis. The concentrations of total protein, DNA, and RNA increased during oogenesis, reflecting the rapid developmental changes taking place in this tissue. Peak protein and DNA levels were reached in the fully fed females, whereas RNA level peaked slightly earlier. Ribosomal RNA (rRNA) was found to be composed of 27.0s, 17.0s, and 4.1s particles. The ratio of 27.0s to 17.0s varied within the developing ovary, yet the 27.0s/4.1s ratio remained constant. The nucleotides of total RNA and rRNA were determined, and the ratio of purine/pyrimidine equaled approximately 1 and remained unchanged during oogenesis.

Bioassays performed on Ornithodoros (Ornithodoros) savignyi (Audouin) demonstrated the presence of a female sex pheromone. Unfed adults and fed adults, after various postfeeding periods, were cross-tested. Two independent criteria were used: the percentage of positive male responses and the time elapsed before these responses. Females were least attractive when unfed and on the feeding day. Their attractiveness increased afterwards reaching the highest values 6 d after feeding (confirmed attractive, CA, females) then decreased gradually thereafter. Males were least responsive during the first 2 d after feeding and became more responsive afterwards reaching a peak 8 d after feeding (sexually active, SA, males). Unfed male responses to CA females were strong but were lower than those of SA males. The fastest responses in all bioassays were those of SA males to CA females. The maximum distance of SA male response to CA females was about 9 cm. SA males were not attracted to nymphs, CA females with sealed coxal orifice, or dead CA females. However, they responded to nymphs coated with coxal fluid collected from CA females. Nymphs and females were not attracted to CA females.

Changes in DNA, RNA, total lipids, phospholipids, and proteins and the activity of certain enzymes and pattern of their isozymes were studied in Hyalomma dromedarii Koch during embryogenesis. Total proteins fluctuated with a net increase (P less than 0.05) on day 20. Total lipids increased during the first half of embryogenesis and then declined with a net decrease to about 60% of the original level. Total phospholipids decreased to half this original level. DNA content increased greatly during cleavage, gastrulation, and organogeny and RNA increased during cleavage and blastula formation. Glucose-6-phosphate dehydrogenase (G6PDH) activity decreased (P less than 0.05), reaching 20% of its original level on day 12. Malic acid dehydrogenase (MDH) activity remained nearly unchanged throughout embryogenesis. Lactic acid dehydrogenase (LDH) activity increased greatly, with the highest level on day 14 with no further change. Acetylcholinesterase (AchE) activity increased greatly during the first 12 d, with no significant change thereafter. Acid (ACP) and alkaline (ALP) phosphatase activity increased during the first 12 d and declined returning to the original level on day 20. Seven AchE and 5 LDH isozymes were detected during different embryogenesis stages. Two MDH, 2 ACP, 1 ALP, and 2 G6PDH isozymes were detected throughout embryogenesis. Treating the mother with 20-hydroxyecdysone was associated with increases in protein and RNA contents and G6PDH and AchE activity and with decreases in ACP and ALP activity in the embryos.

The biochemical effects of juvenile hormone III (JH III) on developing embryos from treated female Argas (Persicargas) arboreus Kaiser, Hoogstraal and Kohls were examined. Exogenous JH III resulted in a decrease in total proteins (P less than 0.001) only during the first 2 d of embryogenesis. There was no significant difference (P greater than 0.05) between RNA and DNA content in eggs from control and JH III-treated females. No significant difference (P greater than 0.05) was observed between control and JH III eggs in their lipid or phospholipid contents throughout embryogenesis. A total of 14-17 protein bands and 6-8 glycoprotein bands were separated by electrophoresis during embryogenesis of A. arboreus with some differences in mobility ratio between bands from control and JH III eggs. Differences in activity and isozyme patterns of malic acid, lactic acid, glucose 6-phosphate dehydrogenase, acid phosphatase, and alkaline phosphatase were not observed during embryogenesis of control and JH III-treated A. arboreus. Differences were observed in esterase activity.

: Thirteen Neurosecretary Cell (NSC) types have been observed in the unfed female Hyalomma dromedarii synganglion. Distribution of these types was based on cell shape, size, and staining reaction of their contents. The NSC are grouped in 13 centers, namely protocerbral, cheliceral, stomodeal pons, palpal, oesophageal, globular, olfactory, glomerular, four pedal, opisthosomal and postoesophageal. Each center contains one or more cell types. Reprints.

TheHyalommadromedarii central nervous system, the synganglion, is an integrated nerve mass concentrated around the esophagus and formed by fusion of a small anterodorsal supraesophageal part an a large posteroventral subesophageal part. The supraesophageal part consists of the protocerebrum including a pair of optic ganglia, a pair of cheliceral ganglia, a pair of pedipalpal ganglia, and the stomodeal pons. The subesophageal part includes four paired pedal ganglia and the complex opisthosomatic ganglion. The peripheral nervous system includes the following pairs of nerves: optic, cheliceral, pedipalpal, primary and accessory (histologically traced); also unpaired pharyngeal and recurrent nerves, four pairs of pedal nerve trunks, each with a hemal branch, and two pairs of opisthosomatic nerves. Each peripheral nerve is traced distally to the innervation site. The salivary glands are innervated anteriorly by branches of the pedipalpal nerve and medially by branches of the hemal nerves associated with the third pedal nerves.

Female Ornithodoros (Pavlovskyella) erraticus ticks maintained at 28 ± 1 °C, 75% RH, and 16 h light/day were investigated for the effect of repeated feeding on body dimensions and weight, fecundity, and preoviposition and oviposition periods. Virgin unfed females were smaller (3.55 × 2.21 mm) and weighed less (5.2 mg) before the 1st meal than mated females before the 2nd meal (4.04 × 2.47 mm, 10.0 mg) and 3rd meal (4.05 × 2.52 mm, 10.7 mg). This increase in weight and dimensions was probably due to growth and maturation of the reproductive system following the 1st meal and/or to retention of part of the meal for slow digestion. Female fecundity in the 1st gonotrophic cycle was lower (90.7 eggs/♀, 4.6 eggs/mg meal) than in the 2nd cycle (180.9 eggs/♀, 7.9 eggs/mg meal) and 3rd cycle (170.9 eggs/♀, 7.0 eggs/mg meal). In virgin females, a part of the 1st meal was probably utilized to complete reproductive system development. The preoviposition period was shorter after the 1st and 2nd meals (11.5 and 10.9 days, respectively) taken in summer and autumn, respectively, than after the 3rd meal taken in winter (23.7 days). The 1st, 2nd, and 3rd oviposition periods listed 18.1, 13.8, and 23.0 days, respectively; the 2nd period was significantly shorter than the 3rd. Daily egg production after the 1st and 3rd meal (6.9 and 8.3 eggs, respectively) was lower than after the 2nd meal (13.6 eggs).

Female Ornithodoros (Pavlovskyella) erraticus ticks maintained at 28 ± 1 °C, 75% RH, and 16 h light/day were investigated for the effect of repeated feeding on body dimensions and weight, fecundity, and preoviposition and oviposition periods. Virgin unfed females were smaller (3.55 × 2.21 mm) and weighed less (5.2 mg) before the 1st meal than mated females before the 2nd meal (4.04 × 2.47 mm, 10.0 mg) and 3rd meal (4.05 × 2.52 mm, 10.7 mg). This increase in weight and dimensions was probably due to growth and maturation of the reproductive system following the 1st meal and/or to retention of part of the meal for slow digestion. Female fecundity in the 1st gonotrophic cycle was lower (90.7 eggs/♀, 4.6 eggs/mg meal) than in the 2nd cycle (180.9 eggs/♀, 7.9 eggs/mg meal) and 3rd cycle (170.9 eggs/♀, 7.0 eggs/mg meal). In virgin females, a part of the 1st meal was probably utilized to complete reproductive system development. The preoviposition period was shorter after the 1st and 2nd meals (11.5 and 10.9 days, respectively) taken in summer and autumn, respectively, than after the 3rd meal taken in winter (23.7 days). The 1st, 2nd, and 3rd oviposition periods listed 18.1, 13.8, and 23.0 days, respectively; the 2nd period was significantly shorter than the 3rd. Daily egg production after the 1st and 3rd meal (6.9 and 8.3 eggs, respectively) was lower than after the 2nd meal (13.6 eggs).

Feeding and engorged nymphs and unfed and feeding adult Hyalomma dromedarii were treated topically with 5, 20, and 50 μg of 2 insect growth regulators (IGRs): IGR-A, 3-[7-(2,6-dichlorophenoxy)-3-methyl-4-heptenyl]-2,2-dimethyloxirane, and IGR-B, 5-[(6,10-dimethyl-4,9-undecadienyl) oxy]- 1,3-benzodioxole. IGR-B was more toxic than IGR-A. Nymphs tolerated both IGRs, but emerging adults exhibited an increasing delayed mortality with dosage increase without attempting to feed; males exhibited higher mortality than females. Ticks treated in the adult stage tolerated all doses of both IGRs. Neither IGR altered the nymphal premolting period or the adult sexual behavior, but both caused a small reduction in fertility (egg hatch) of both sexes. The results suggest that these IGRs do not mimic or antagonize naturally occurring juvenoid(s) in H. dromedarii and/or that the administration method is unsuitable.

The neurohemal-endocrine organs of female Hyalomma dromedarii consist of (a) 2 pairs of lateral segmental organs (LSO) innervated by hemal nerves originating from the 1st and 2nd pedal nerve roots and (b) the neurohemal organ (NHO) of 1 dorsal lobe and 2 ventrolateral lobes innervated by compound nerves. The LSO are most active in feeding females and in inseminated, fully engorgd females. The NHO enlarges when virgin and inseminated females feed. Neuronal cell secretion is most abundant in partly fed virgin females.