A new meatless diet for adult screwworm (Diptera: Calliphoridae)

Screwworm flies, Cochliomyia hominivorax (Coquerel), were fed on honey and spray dried egg product; honey, molasses, and spray dried egg product; honey and spray dried meat protein; as well as on a control diet of honey and horsemeat, which is the standard diet used for screwworm adult colony in the mass-rearing facility. In general, the weight of eggs laid by females fed on the diet of spray dried egg product was significantly higher than that laid by females fed on the standard horsemeat diet. Egg production declined when spray dried meat protein replaced the egg product. Partial replacement of honey with molasses in the egg diet did not decrease egg production, compared with the control diet. The use of spray dried egg diet has advantages over the horsemeat diet, such as storage, handling, preparation, feeding, and expense. A cost analysis suggests that replacing the horsemeat with spray dried egg product, and half of the honey with molasses, would reduce the cost of the diet by more than US $100,000 annually.     

杀虫威对棉铃虫、烟青虫、菜青虫的防治效果

田间试验表明 ,新氨基甲酸酯杀虫剂杀虫威对鳞翅目害虫棉铃虫、菜青虫、烟青虫防治效果优良。杀虫威 2 0 %EC在河南防治 2代棉铃虫使用剂量 1 0g (a.i.) 667m2 药后 2～ 7d ,校正防效为90 65 %～ 97 72 % ,在山东药后 3～ 5d ,防效为 85 1 7%～ 91 2 3 % ,7 5g (a .i.) 667m2 相应药效两地分别为 88 41 %～ 95 2 7%和 81 40 %～ 85 61 % ;防治 3代棉铃虫使用剂量 2 0g (a.i.) 667m2 药后 2～ 5d ,防效两地分别为 83 93 %～ 86 1 5 %和 85 5 3 %～ 88 2 9% ,1 5g (a .i.) 667m2 相应药效分别为 77 66%～80 2 3 %和 78 5 0 %～ 83 75 %。防治烟青虫使用剂量 1 0g (a.i.) 667m2 药后 3～ 7d校正防效为 85 5 7%～ 88 2 9% ,7 5g (a .i.) 667m2 相应药效为 81 5 1 %～ 86 1 1 %。防治菜青虫使用剂量 7 5～ 1 0g (a .i.) 667m2 药后 3～ 7d防效为 87 5 0 %～ 96 1 1 %。     

A safer insecticide for herbarium use

Pyrethrins, the active ingredients of the insecticide pyrethrum, are very effective in killing insects but are quite harmless to mammals. When combined with silica gel to form Drione powder, they can be applied inside herbarium cases for long-term protection against insects. Preliminary tests at the New York Botanical Garden have shown that Drione powder or aerosol spray readily kills anobiid beetles. Drione has potential as a safer alternative to dangerous chemicals that have been used in the past.     

Evaluation of a new anaerobic power testing system

The purpose of this study was to evaluate the reliability of a new anaerobic athletic performance system. This system is proposed to assess vertical jump height, anaerobic power through repetitive jumping, and reaction to both an auditory and visual stimulus. One hundred twenty-three subjects (92 men and 31 women; mean +/- SD: age, 20.5 +/- 2.1 years; body weight, 83.1 +/- 20.4 kg; height, 176.0 +/- 9.2 cm) volunteered to participate. To assess reliability of the new testing device, subjects were tested on 3 separate occasions (T1, T2, and T3). At least 72 hours but not more than 1 week separated each laboratory visit. During each testing session subjects performed a countermovement jump (CMJ), a 30 consecutive jumps anaerobic power test (30JT), and reaction to both an auditory and visual stimulus. Results showed no differences between T1, T2, and T3 in either CMJ height or 30JT assessments. However, reaction to an audible or visual stimulus significantly improved during each testing session. Intraclass reliability of the CMJ and the 30JT was greater than 0.96 across the 3 trials. Pearson correlation coefficients of r > 0.90 were seen for the CMJ and 30JT, indicating a high test-retest reliability. The test-retest reliability for the reaction tests were lower (r ranging from 0.72 to 0.83). A Bland-Altman plot showed limited agreement between methods of vertical jump height assessment. Results indicate that this new testing device shows high reliability to assess both CMJ height and anaerobic power. In addition, anaerobic power assessment in a jump test provides a specific measure of anaerobic power for many sports incorporating similar performance patterns.     

Evaluation of a new fiber-optic pressure recording system for cardiovascular measurements in mice

We have tested a new fiber-optic pressure recording system, Samba, with a thin fiber [outer diameter (OD) = 0.25 mm] and a pressure sensor (length and OD = 0.42 mm) attached to the end. The accuracy of the system tested in vitro was good, with a coefficient of variation of 2.54% at 100 mmHg. The drift was <0.45 mmHg/h, and the temperature sensitivity was approximately 0.07 mmHg/1 degrees C between 22 and 37 degrees C. The frequency response characteristics were similar to a 1.4-Fr Millar catheter (0-200 Hz). Introduction of the Samba sensor from the right carotid artery into the left ventricle in six mice caused no drop in mean aortic pressure, whereas introduction of a 1.4-Fr Millar catheter (OD = 0.47 mm; n = 6) caused a pressure drop from 91.6 +/- 9.2 to 65.1 +/- 6.2 mmHg; P < 0.05. Thus the Samba sensor system may represent a new alternative to assess hemodynamic variables in the murine cardiovascular system.     

A rapid genetic screening system for identifying gene-specific suppression constructs for use in human cells

We describe a rapid cell-based genetic screen using fission yeast for identifying efficient gene suppression constructs (GSCs) from large libraries (10⁵) for any target sequence for use in human cells. In this system, target sequences are fused to the 5′ end of the lacZ reporter gene and expressed in yeast. Random fragment expression libraries derived from the target sequence are screened in the fusion gene-expressing strain using the lacZ gene-encoded colony color phenotype. We demonstrate the utility of this screening assay by identifying a range of different GSCs for the fission yeast ura4 gene and human c-myc and Chk1 sequences, including rare efficient suppressors. GSCs specific for c-myc were shown to regulate expression of both a c-myc–lacZ fusion gene and the endogenous c-myc gene in human cells.     

Evaluation of a new antigen for diagnosis of Helicobacter pylori infection in stool of adult and children

Background: Nowadays, there is an increasing interest in noninvasive methods to diagnose Helicobacter pylori infection. Indeed, they can profitably replace endoscopy in predicting the diagnosis. The stool antigen test for H. pylori is a noninvasive immunoassay to diagnose active infection with this bacterium in human fecal samples. The aim of this study was detection of alkyl hydroperoxide reductase protein (AhpC) antigen by immunoblotting in stool samples for diagnosis of H. pylori. Materials and Methods: Chromosomal DNA from H. pylori was isolated. AhpC gene was amplified by PCR, These amplicons were cloned into pTZ57R/T cloning vector then subcloned into pQE30 expression vector and overexpressed using isopropyl‐beta‐D‐thiogalactopyranoside in E. coli M15. AhpC protein was purified by affinity chromatography. Rabbits were immunized with the purified AhpC protein for the production of antibodies. To determine the accuracy of the test for diagnosing H. pylori infection from stool, we evaluated 84 patients (6–81 years old) using Western blot analysis by rabbit anti‐AhpC antibody. Positive rapid urease test on biopsy samples was considered as the gold standard. Results: AhpC gene was overexpressed, and AhpC protein was purified. Rabbit anti‐AhpC antibody produced after immunization with the purified AhpC protein. By immunoblotting, we detected AhpC protein in the positive stool samples. The test showed a 83.3% sensitivity (95% CI: 69.8–92.5%) and a 91.7% specificity (95% CI: 77.5–98.2). Among the children, the sensitivity was 88.2% (95% CI: 63.6–98.5) and the specificity was 100% (95% CI: 69.2–100); in adults, the sensitivity and specificity were 80.6% (95% CI: 62.5–92.5) and 88.5% (95% CI: 69.8–97.6), respectively. Conclusions: Using of AhpC antigen for diagnosis of H. pylori infection is a useful noninvasive method, accurate in adolescents and children, and can be used for the development of a stool antigen detection kit for H. pylori.     

Age determination in the adult screwworm (Diptera: Calliphoridae) by pteridine levels

Fluorescence spectrophotometry was used to assess the possible use of pteridines in the compound eyes to estimate the age of adult screwworms, Cochliomyia hominivorax (Coquerel). Factors affecting the quantities of pteridines include temperature and head size. No difference in pteridine levels was found among flies fed protein or carbohydrate. A regression model for estimating the age of female screwworms was constructed. The model uses head capsule size and relative pteridine quantities and assumes a constant body temperature of 30 degrees C. This regression formula has an r2 of 0.74. Our study extends the use of pteridine accumulation for age determination from obligate sanguinivorous Diptera to an autogenous species that feeds facultatively on nectar and wound exudates. The technique appears to provide a valid means to determine age of these flies.     

Genetics of screwworm: new genetic markers and preliminary linkage map

Eight new genetic markers for Cochliomyia hominivorax (Diptera: Calliphoridae), the screwworm, are characterized. The markers include three eye mutants, lemon-eye (le), cherry-eye (ch), and red-eye (re); one wing mutant, curly-wing (cw); and four allozyme markers, amylase (Amy-1), glycerol-3-phosphate dehydrogenase (Gpd), phosphoglucomutase (Pgm), and octanol dehydrogenase (Odh). The markers are associated into four linkage groups. Radiation-induced translocations were used to correlate the linkage groups with their respective chromosomes. A preliminary genetic linkage map with these and three previously characterized loci is presented.     

Evaluation of a new model system for studying the formation of heterocyclic amines

Heterocyclic amines (HAs) are an important class of food mutagens and carcinogens, which can be found in cooked meat and fish. Increasing heating temperatures and times usually increase mutagenic activity in meat and meat extracts during cooking. We developed a model system, which allows to examine the effects of precursor composition and heating conditions (time and temperature) on the formation of HAs in meat. Homogenized and freeze dried meat samples (beef, pork chops, chicken breast and turkey breast) are heated with diethylene glycol in closed vials under stirring in a thermostated heating block. After an appropriate sample preparation (extraction and clean-up) ten different HAs were measured by HPLC analyses with gradient elution and mass selective detection. The time courses of HA-formation in the different kinds of meat at varying heating temperatures were determined up to heating times of 30 min. 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) was the most abundant HA in these experiments and reached the highest concentrations in the beef meat samples, as did the other HAs (MeIQ, AalphaC) at 220 degrees C in the heating block under stirred conditions. Additionally the influence of the antioxidant TBHQ (t-butylhydroquinone) on the formation of HAs in the model system was tested. However TBHQ effected only slight reductions of HA formation in all kinds of meat.     

The use of a new silica gel separation system in thin-layer chromatography

Summary A new method for the chromatography of amino acids is described in which D- or L-amino acids are separated on ICT-Empore thin-layers. The compounds are developed ascending by means of normally used solvent systems. An overloading of the plates is nearly impossible. On the other hand, hydrophilic amino acids are well separated. A second front, moving with these amino acids and emerging with ninhydrin stain, was not detectable.     

Molecular characterization of esterase E3 gene associated with organophosphorus insecticide resistance in the New World screwworm fly, Cochliomyia hominivorax

Abstract.  The New World screwworm, Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae), is one of the most important myiasis-causing flies in South America. It is responsible for severe economic losses to livestock producers, mainly because it causes mortality in newborn calves and reductions in the quality of leather and in the production of milk and meat. The economic losses caused by myiasis, along with those caused by other internal and external parasites, are the main factors limiting meat production. In Brazil, C. hominivorax has been controlled by applying insecticides, particularly organophosphate (OP)-based compounds. However, the improper and continuous use of these chemicals can lead to the selection of OP-resistant strains. This, associated with the fast development of OP resistance in other myiasis-causing flies, shows the importance of investigating resistance in C. hominivorax. Based on the findings of previous studies, the objective of the current work was to isolate and sequence the E3 gene in C. hominivorax. Mutations at the positions (Gly137 and Trp251) responsible for conferring OP resistance in Lucilia cuprina and Musca domestica L. (Muscidae) were identified in C. hominivorax . In addition, the orthologous region in C. hominivorax contained motifs that are highly conserved among carboxyl/cholinesterases and contribute to the catalytic mechanism of the active site. The characterization of this gene in natural populations of New World screwworm can be an important tool for monitoring resistance to insecticides throughout its current geographic distribution. This will provide information for the selection and implementation of more effective pest management programmes.     

Attracting adult New World screwworm,Cochliomyia hominivorax,to odour-baited targets in the field

Abstract. A field study in Libya investigated aspects of Cochliomyia hominivorax behaviour relevant to the operation of a target-based control system. Flies were readily caught by electrified targets, but only when baited with the attractant ‘swormlure-4’. Target size (0.25-lm²) did not affect catch, but black targets caught twice as many flies as red ones. Omitting the most volatile component of swormlure-4, dimethyl disulphide, significantly reduced catches of both sexes of C. hominivorax in wind-orientated traps, but only reduced the capture of females significantly on targets. A new polythene sachet dispenser for odours was tested; four to six such sachets filled with swormlure-4 less dimethyl disulphide gave an equivalent catch to one of the standard bottle plus wick dispensers using the same attractant, although they dispensed odour at about half the rate. From direct observations, fewer than 40% of flies contacted the target for more than 10 s on any one visit. From catches on an intermittently-active electrocuting grid, it was calculated that there is a c. 40% rate of multiple contacts of flies with the target.     

Age determination using the apodeme structure in adult screwworm flies (Cochliomyia hominivorax)

A method of age determination of adult screwworm flies is described and documented. This method uses the diurnal differences in the deposition of apodeme layers as a basis for counting the age in days since eclosion. The method is accurate to plus or minus one day, and can be determined on meterial that has been dried, pinned, frozen, or preserved in ethanol or other fixatives.