Impact of pyrethroid-impregnated curtains on Phlebotomus papatasi sandflies indoors at Khartoum, Sudan

Laboratory and field investigations were made in an endemic focus of cutaneous leishmaniasis in Khartoum State, Sudan, to evaluate the effects of permethrin-impregnated curtains on the human-biting activity, nocturnal activity and resting behaviour of the vector sandfly Phlebotomus papatasi (Diptera: Psychodidae) indoors. Laboratory bioassays showed that curtains impregnated with 0.5, 1.0 or 1.5 g/m2 permethrin all gave 100% mortality within 24h of exposure of P. papatasi for 3 min. Under natural field conditions, the biting activity indoors and the resting density of P. papatasi were significantly reduced (P<0.001 and P=0.036, respectively) in rooms provided with permethrin-impregnated curtains as compared to control rooms left without curtains or fitted with unimpregnated curtains. No significant difference was found between the numbers of nocturnally active P. papatasi collected in rooms provided with impregnated curtains and rooms left without curtains or provided with unimpregnated curtains (P=0.377). Evidently P. papatasi was not repelled by these doses of permethrin on curtains, but the survival rate of sandflies collected from test rooms provided with permethrin-impregnated curtains was significantly reduced (P=0.036). We conclude that use of permethrin-impregnated curtains may provide a good control method for P. papatasi and other endophilic and/or endophagic sandfly vectors of leishmaniasis.     

The hemogram,serum biochemistry,and electrolyte profile of the free-ranging Cayo Santiago rhesus macaques (Macaca mulatta)

Sixty-four male and 33 female free-ranging rhesus monkeys (Macaca mulatta) from one of six social groups on the island of Cayo Santiago, Puerto Rico, were surveyed to establish normal values for the hemogram and serum biochemical and electrolytes for the colony. Mean values (± 1 SD) are reported by sex for each of three age groups (2–3, 4–9 and ≥ 10 years). All adult females (≥ 4 years) were pregnant. There were significant differences for a number of variables compared to the range reported in the existing literature, and among the age and sex groups in the sampled population.     

Improved Paraffin Schedules for Plant Tissues

The two paraffin schedules here presented have produced less distortion in plant tissues than those commonly used. Both are modifications of the schedule described by Hemenway.¹ Schedule A is very similar to that described by Hewitt.² Schedule B usually causes less distortion than A but staining is not so bright as after A.     

Adenovirus origin of DNA replication: sequence requirements for replication in vitro.

The initiation of adenovirus DNA takes place at the termini of the viral genome and requires the presence of specific nucleotide sequence elements. To define the sequence organization of the viral origin, we tested a large number of deletion, insertion, and base substitution mutants for their ability to support initiation and replication in vitro. The data demonstrate that the origin consists of at least three functionally distinct domains, A, B, and C. Domain A (nucleotides 1 to 18) contains the minimal sequence sufficient for origin function. Domains B (nucleotides 19 to 40) and C (nucleotides 41 to 51) contain accessory sequences that significantly increase the activity of the minimal origin. The presence of domain B increases the efficiency of initiation by more than 10-fold in vitro, and the presence of domains B and C increases the efficiency of initiation by more than 30-fold. Mutations that alter the distance between the minimal origin and the accessory domains by one or two base pairs dramatically decrease initiation efficiency. This critical spacing requirement suggests that there are specific interactions between the factors that recognize the two regions.