Effects of Mesocyclops longisetus (Copepoda:Cyclopidae) on mosquitoes that inhabit tires: influence of litter type, quality, and quantity

A 59-week study was conducted to evaluate the impact of adult Mesocyclops longisetus populations on larval mosquito species inhabiting tires. Greater than 90% reduction of number of 1st and 2nd instars was recorded by 4 wk with 90% reduction of number of 3rd and 4th instars after 7 wk. Reduced control was noted with the onset of cooler winter water temperature. Overall. a 52% reduction in the number of 1st and 2nd instars was achieved, and a 57% reduction was noted in number of 3rd- and 4th-instar mosquito larvae. Cooler temperatures resulted in a decline of adult Mesocyclops, which resulted in reduced larval control. Significantly greater numbers of Mesocyclops adults were collected in tires with either new litter or heavy amounts of litter regardless of litter type. Lastly, litter type, either oak leaves or pine needles, did not influence mosquito reduction or abundance of Mesocyclops populations.     

The biology and predatory potential of notonectid bug, Enithares indica (Fabr) against mosquito larvae

An 18-year-old white male developed severe hepatic veno-occlusive disease (VOD) during an autologous bone marrow transplant for primary refractory nodular sclerosing Hodgkin's disease. As a result of VOD-induced hepatic dysfunction, coagulation studies revealed depression of vitamin K dependent procoagulant factor VII. Intravenous recombinant tissue plasminogen activator 20 mg over h on 4 consecutive days and continuous heparin infusion (1000 unit bolus followed by 150 units/kg/day) resulted in rapid reversal of the VOD syndrome. During treatment, procoagulant factors II, VII, IX and X levels increased indicating the return of hepatic synthesizing capacity. Factor V levels, which were elevated pre-therapy, also rose dramatically. Plasma antigen levels of protein C, a natural anticoagulant, remained severely depressed. No clinical evidence of bleeding and only minimal systemic fibrinolysis was noted. Despite concerns regarding the use of lytic therapy in a thrombocytopenic post-BMT patient, serial measurements of coagulation parameters during severe VOD suggested that low dose rt-PA improved portions of the systemic hemostatic profile.     

Induced immunity against the mosquito Anopheles stephensi Liston (Diptera: Culicidae): effects on mosquito survival and fecundity

Mice were immunised three to five times with extracts of Anopheles stephensi heads, midguts, ovaries or fat bodies. At each immunisation the effects of feeding An. stephensi on the mice was determined, and changes in mosquito longevity and fecundity examined as the immune response developed. Although variability was common between control cages, significant and consistent reductions in mosquito longevity were observed when midguts were used as immunogens. Other extracts caused transient reductions in mortality. Fecundity was reduced significantly in mosquitoes fed upon mice immunised with each extract in at least one experiment. Mosquitoes fed upon fat-body-immunised mice showed delayed egg-laying as well as overall reduction in fecundity. The results confirm the feasibility of targeting mosquito antigens for novel vaccine development, but the "shotgun" approach used probably fails to successfully hit a suitable target antigen with any consistency. The natural variation in mosquito mortality can be countered by rigorous statistical analysis which can identify subtle effects in a very "noisy" experimental system. The midgut is the obvious target organ for anti-mosquito vaccine development and future work will focus on targeting components of this tissue for further immunisations.     

Performance of ULV formulations (Pesguard 102/Vectobac 12AS) against three mosquito species

To study the effects of percutaneous ethanol injection therapy on livers, we investigated necrotic changes after ethanol injection and fibrotic changes during the repair process in cirrhotic livers in comparison with normal livers. Male rats were treated with oral doses of 3'-methyl-4-dimethylaminoazobenzene and thioacetamide to produce liver cirrhosis. Both control animals and cirrhotic animals were injected with 0.2 ml of absolute ethanol into livers. Histological samples were cut serially, and the maximum areas of necrosis and fibrosis were measured until 28 days after the injection. Although the maximum area of necrosis was not different between cirrhotic livers and control livers, the average fibrotic ratio [(maximum fibrotic area/maximum necrotic area + maximum fibrotic area) x 100] was 64% in control livers (n = 9) and 40% in cirrhotic livers (n = 9; p < 0.05). The fibrotic repair process after ethanol injection seems to be impaired in cirrhotic livers as compared with normal livers.     

Shock chloramination: potential treatment for Chironomidae (Diptera) larvae nuisance abatement in water supply systems

In the early 1990s, infestations of midge larvae (Chironomidae, Chironomus sp.) were discovered in the potable water system of Tel Aviv, Israel. Control measures, such as draining and cleaning tanks, spraying water into the tank's air space, and electrocution traps of midge adults, were either inadequate or ineffective. In this system, monochloramine concentrations of up to 0.75 mg/liter are used routinely as a secondary disinfectant. This chemical was tested in the laboratory as a toxicant of midge larvae. The mortality of 4th instar midge larvae after short exposure to high chloramine concentrations (LC50 values of 32 mg/liter for 75 min) suggested the efficacy of instituting a Shock Chloramination treatment program. Tanks were partially drained until they contained only 20 cm of water and were then temporarily disconnected. Chloramine was added to this water to produce a concentration of approximately 70 mg/liter for 1-2 h. Subsequently, all dead chironomids were flushed out, and the tank was refilled to attain the operational volume of water. A 2nd identical treatment of water in the tank was suggested 7 d later to kill midges from reproductive adults and egg-masses that survived the 1st treatment. This treatment program was tested in commercial covered tanks and gave complete control of these pests for 6-10 wk. These results suggest that this treatment program may effectively prevent midge outbreaks in Israel's drinking water supply system during the height of the summer.     

Restriction map of the 125-kilobase plasmid of Bacillus thuringiensis subsp. israelensis carrying the genes that encode delta-endotoxins active against mosquito larvae

A large plasmid containing all delta-endotoxin genes was isolated from Bacillus thuringiensis subsp. israelensis; restricted by BamHI, EcoRI, HindIII, KpnI, PstI, SacI, and SalI; and cloned as appropriate libraries in Escherichia coli. The libraries were screened for inserts containing recognition sites for BamHI, SacI, and SalI. Each was labeled with 32P and hybridized to Southern blots of gels with fragments generated by cleaving the plasmid with several restriction endonucleases, to align at least two fragments of the relevant enzymes. All nine BamHI fragments and all eight SacI fragments were mapped in two overlapping linkage groups (with total sizes of about 76 and 56 kb, respectively). The homology observed between some fragments is apparently a consequence of the presence of transposons and repeated insertion sequences. Four delta-endotoxin genes (cryIVB-D and cytA) and two genes for regulatory polypeptides (of 19 and 20 kDa) were localized on a 21-kb stretch of the plasmid; without cytA, they are placed on a single BamHI fragment. This convergence enables subcloning of delta-endotoxin genes (excluding cryIVA, localized on the other linkage group) as an intact natural fragment.     

Host utilization by the salmon louse Lepeophtheirus salmonis (Copepoda: Caligidae) in the Sea of Japan

Complex dynamic properties of a bolus in the mouth are specified by touch. Cooperation between touch and taste may help to specify the character of the bolus. The role of touch in specifying the presence of the oral bolus, in contrast to it's characteristics, remains a theoretical and experimental challenge.     

The effect of the volatile oils of Chenopodium ambrosioides and Thymus vulgaris against the larvae of Lucilia sericata (Meigen)

We have isolated a stable, transplantable, and small glucagonoma (MSL-G-AN) associated with abrupt onset of severe anorexia occurring 2-3 wk after subcutaneous transplantation. Before onset of anorexia, food consumption is comparable to untreated controls. Anorexia is followed by adipsia and weight loss, and progresses rapidly in severity, eventually resulting in reduction of food and water intake of 100 and 80%, respectively. During the anorectic phase, the rats eventually become hypoglycemic and hypothermic. The tumor-associated anorexia shows no sex difference, and is not affected by bilateral abdominal vagotomy, indicating a direct central effect. The adipose satiety factor leptin, known to suppress food intake by reducing hypothalamic neuropeptide Y (NPY) levels, was not found to be expressed by the tumor, and circulating leptin levels were reduced twofold in the anorectic phase. A highly significant increase in hypothalamic (arcuate nucleus) NPY mRNA levels was found in anorectic rats compared with control animals. Since elevated hypothalamic NPY is among the most potent stimulators of feeding and a characteristic of most animal models of hyperphagia, we conclude that the MSL-G-AN glucagonoma releases circulating factor(s) that overrides the hypothalamic NPY-ergic system, thereby eliminating the orexigenic effect of NPY. We hypothesize a possible central role of proglucagon-derived peptides in the observed anorexia.     

Preliminary study of the larvae (Nematode: Ascaridida) Paralichthys orbignyyanus parasite (Valenciennes, 1839) and Paralichthys patagonicus (Pisces: Pleuronectiformes)

The present paper deals with a preliminary study of different larvae of nematoda found in two species of fish Paralichthys orbignyanus and Paralichthys patagonicus. In P. orbignyanus the genus Terranova type A was found. Both Anisakis type I and Hysterothylacium were present in P. patagonicus. Different types of larvae belonging to genera Terranova (B and B'), Contracaecum (A and B) and Raphidascaris occurred in both P. patagonicus and P. orbignyanus. The specimens of Nematoda were described and the corresponding morphometric indexes were determined. The abundance of Nematoda obtained in relation to the diet of the flounders led us to conclude that P. orbignyanus feeds basically on crabs and fish, while P. patagonicus has a more diverse diet.     

Laboratory evaluation in the diagnosis of Lyme disease

PURPOSE: To provide a qualitative evaluation of the predictive value of the laboratory diagnosis of Lyme disease and to use the resultant data to formulate guidelines for clinical diagnosis. DATA SOURCES: A MEDLINE search of English-language articles or articles with English-language abstracts published from 1982 to 1996. DATA EXTRACTION: Sensitivity, specificity, and likelihood ratios were calculated, and a random-effects model was used to combine the proportions from the eligible studies. Prespecified criteria were used to determine which studies were eligible for analysis. DATA SYNTHESIS: Laboratory testing in general is not clinically useful if the pretest probability of Lyme disease is less than 0.20 or greater than 0.80. When the pretest probability is 0.20 to 0.80, sequential testing with enzyme-linked immunosorbent assay and Western blot is the most accurate method for ruling in or ruling out the possibility of Lyme disease. CONCLUSIONS: Laboratory testing is recommended only in patients whose pretest probability of Lyme disease is 0.20 to 0.80. If the pretest probability is less than 0.20, testing will result in more false-positive results than true-positive results; a negative test result in this situation effectively rules out the disease.     

Clinical evaluation of Augpenin (clavulanic acid-ticarcillin) in urinary tract infections: especially against beta-lactamase producing strains

Augpenin contains ticarcillin (TIPC) and clavulanic acid (CVA), at a ratio of 15:1. The beta-lactamase inhibitor, CVA, has been added to protect the TIPC from inactivation by beta-lactamase. To investigate the drug efficacy and safety against urinary tract infections (UTI), Augpenin was administered to 33 patients with chronic complicated UTI and 7 patients with acute pyelonephritis. Thirty two cases were evaluable by the UTI criteria. Excellent results were obtained in 6 of the cases of acute pyelonephritis, and moderate results in 1 case, with an overall effectiveness rate of 100%. Excellent results were obtained in 14 of the cases of chronic complicated UTI, moderate results in 9 cases, and poor results in 2 cases, with an overall effectiveness rate of 92%. No adverse reactions were noted, but a transient elevation of glutamic oxaloacetic transaminase and glutamic pyruvic transaminase levels was observed in 2 cases.     

Larvicidal activity of the entomopathogenic fungus Tolypocladium cylindrosporum (Deuteromycotina: Hyphomycetes) on the mosquito Aedes triseriatus and the black fly Simulium vittatum (Diptera: Simuliidae)

Laboratory bioassays evaluated the pathogenicity of the entomopathogenic fungus Tolypocladium cylindrosporum against Aedes triseriatus. All larval instars were found to be susceptible at temperatures from 18 to 25 degrees C. Blastoconidia were more virulent than conidia. Mortality was proportional to exposure time in assays using blastoconidia. Blastoconidia and exposure time appear to be a more adequate method for bioassay of T. cylindrosporum virulence than the standard procedure of using conidia and continuous exposure. Tolypocladium cylindrosporum was also active against Simulium vittatum black fly larvae, but the mortality recorded was much lower than with mosquito larvae.     

A statistical model of the dynamics of a mosquito vector (Culex tarsalis) population

A model of the dynamics of a mosquito Culex tarsalis is derived that includes the life states through which the mosquito proceeds. Transition probabilities from one state (egg, larva, pupa and adult) to another are derived and they depend on the duration of stay and mortality in each state. A formula is derived for the expected number of mosquitoes alive at any time during the spring or summer. This formula depends on the number of eggs oviposited and the transition probabilities. Data are used to estimate the parameters and to illustrate the usefulness of this model in examining the effect of changes in mosquito survival on the dynamics of the population.