Influence of protein hydrolysate baits on oviposition in the apple maggot, Rhagoletis pomonella

Ovipositional responses of apple maggot (AM), Rhagoletis pomonella (Walsh), females were studied in the laboratory on apples (var: Golden Delicious) treated with different rates of four protein hydrolysate baits in choice and no-choice tests. Protein hydrolysate baits at rates of 0.5 and 1% had no significant effect, but oviposition was greatly reduced at higher rates of 5 and 10%. Apple maggot females exposed to apples treated with protein hydrolysate baits at a rate of 10% made 41–71% fewer punctures and laid 41–73% fewer eggs than in untreated control. No oviposition activity was shown on apples treated with 25 and 100% Nulure®. In no-choice tests the AM females laid 75–96% fewer eggs in apples treated with 10 and 25% Nulure compared to controls and no oviposition occurred in apples treated with 100% Nulure. Apple maggot females arrived in similar numbers on apples treated with 10% Nulure and untreated apples, but only 5% of those arriving on Nulure-treated apples showed ovipositor boring with no egg deposition while 60% of females arriving on untreated apples showed ovipositor boring activity and laid an average of 2.5 eggs per apple. In another experiment, individual AM females displayed similar behavioral responses to 10% Nulure-treated apples; none of the 56 females tested on treated apples displayed ovipositor boring activity, but 59% of the females (N=56) tested on untreated apples displayed ovipositor boring within 5 min of their arrival. Ninetyeight percent of AM females stayed and fed on fruit surfaces for 5 min on Nulure-treated apples without ovipositor boring compared to only 2% on untreated apples. Of the females that arrived on untreated apples, 39% flew away within 5 min without ovipositor boring compared to only 2% of those that arrived on Nulure-treated apples. Results of these two behavioral experiments suggest that upon arrival on a protein bait-treated apple, an apparent change of behavior occurs in AM females and instead of attempting to oviposit, they attempt to feed on fruit surfaces resulting in reduced oviposition activity. These results indicate that the feeding and oviposition-related activities of AM females are probably mutually exclusive and that the feeding behavior preempts oviposition activities on host fruits treated with higher rates of protein hydrolysate baits.     

Positive residues involved in the voltage-gating of the mitochondrial porin-channel are localized in the external moiety of the pore.

The role of positive charges located on the hydrophilic surface of the mitochondrial outer membrane channel was investigated by studying the interaction between LDAO-solubilized porin and a cation-exchanger column. The binding of porin to the column material was inhibited when the elution buffer had a pH of 9 or when 2 mM dextran sulfate was added to the buffer at neutral pH. Interestingly, the addition of a synthetic copolymer of methacrylate, maleate and styrene known as a potent modulator of the voltage-dependence, did not influence the interaction between column material and porin. Incubation of porin with fluorescein isothiocyanate (FITC) resulted in the isolation of a porin fraction in which on average two lysines located on the surface of the pore-forming complex per 35 kDa polypeptide were modified. The voltage-dependence of the fluorescein isothiocyanate modified porin was strongly decreased as compared with the unmodified porin. The experiments presented here give the first biochemical evidence that positively charged lysine residues located on the surface of the channel-forming complex are responsible for the gating of the mitochondrial porin-channel.     

On the computation of the tertiary structure of globular proteins. III. Inter-residue distances and computed structures

An analysis of geometrical models for computing the tertiary structure of globular proteins from the primary structure is presented. The roles of initial configuration, input information on inter-residue distances and the errors in this information are delineated. It is shown that for local information like that on secondary structure, the calculated structure is very sensitive to errors and to the initial configuration. Thus, such information is far from adequate for predicting the tertiary structure. On the other hand, global information on all the inter-residue distances is quite insensitive to errors. A semi-empirical method is presented to estimate these distances and the calculated structures are given for two proteins—pancreatic trypsin inhibitor and parvalbumin. These structures have good resemblances to those determined by X-ray diffraction. A strategy for further refinement of the method is indicated.     

Temporary increase in chromosome breakage in an infant prenatally exposed to lead

Summary An infant exposed to high levels of lead in utero was found to have increased numbers of cells with chromosome breaks in blood samples obtained at 6 weeks and 3 months of life. Later samples did not show significant abnormality. Physical and neurological examinations of the patient up to 18 months of age gave results within normal limits.     

The subcellular distribution and partial characterization of cholinesterase activities of canine platelets.

The multiple cholinesterase activities in canine platelets have been investigated. Platelets were homogenized by rapid decompression under nitrogen, glass tube/Teflon pestle, and glycerol lysis techniques. Rapid decompression under nitrogen technique was found to be the most efficient and gentle method for cell disruption. Homogenates were subfractionated using sodium diatrizoate density gradients. Marker enzyme assays and pulse labeling experiments with 5-hydroxyl[14C] tryptamine and [125I] thrombin on prepared subcellular fractions confirmed that the soluble, plasma membrane and the granule-1 fractions were all in reasonably pure form. Furthermore, labeling of the plasma membrane with [125I] thrombin is cited as the first successful attempt at attaining significantly bound marker for this structure. Cholinesterase activity distributions measured in these fractions indicated that about 30% of the activity was present in the plasma membrane, 50% in granule-1 and 5% in soluble fractions. Kinetic data of cholinesterase activities obtained from intact platelets, plasma membrane preparations and platelet release supernatants indicated that they are strikingly similar.     

Protection against oxidative stress by vitamin D in cone cells

Photoreceptor degeneration (PD) refers to a group of heterogeneous outer retinal dystrophies characterized by the death of photoreceptors. Both oxidative stress and inflammation are involved in the pathogenesis of PD. We investigate whether vitamin D has a potential for the treatment of PD by evaluating the anti‐oxidative stress and anti‐inflammatory properties of the active form of vitamin D₃, 1,α, 25‐dihydroxyvitamin D₃, in a mouse cone cell line, 661W. Mouse cone cells were treated with H₂O₂ or a mixture of H₂O₂ and vitamin D; cell viability was determined. The production of reactive oxygen species (ROS) in treated and untreated cells was measured. The expression of key anti‐oxidative stress and inflammatory genes in treated and untreated cells was determined. Treatment with vitamin D significantly increased cell viability and decreased ROS production in 661W cells under oxidative stress induced by H₂O₂. H₂O₂ treatment in 661W cells can significantly down‐regulate the expression of antioxidant genes and up‐regulate the expression of neurotoxic cytokines. Vitamin D treatment significantly reversed these effects and restored the expression of antioxidant genes. Vitamin D treatment also can block H₂O₂ induced oxidative damages. The data suggested that vitamin D may offer a therapeutic potential for patients with PD.     

Rhinitis,Ocular, Throat and Dermal Symptoms,Headache and Tiredness among Students in Schools from Johor Bahru,Malaysia: Associations with Fungal DNA and Mycotoxins in Classroom Dust

There are few studies on rhinitis and sick building syndrome (SBS) among students in tropical countries. We studied associations between levels of five fungal DNA sequences, two mycotoxins (sterigmatocystin and verrucarol) and cat allergen (Fel d 1) levels in schools and rhinitis and other weekly SBS symptoms in the students. Fungal DNA was measured by quantitative PCR and cat allergen by ELISA. Pupils (N = 462) from eight randomly selected schools in Johor Bahru, Malaysia participated (96%). Dust samples were collected by cotton swabs and Petri dishes exposed for one week. None of the schools had a mechanical ventilation system, but all classrooms had openable windows that were kept open during lectures and indoor CO₂ levels were low (mean 492 ppm; range 380–690 ppm). Weekly nasal symptoms (rhinitis) (18.8%), ocular (11.6%), throat (11.1%), dermal symptoms, headache (20.6%) and tiredness (22.1%) were common. Total fungal DNA in swab samples was associated with rhinitis (p = 0.02), ocular symptoms (p = 0.009) and tiredness (p = 0.001). There were positive associations between Aspergillus versicolor DNA in Petri dish samples, ocular symptoms (p = 0.02) and tiredness (p = 0.001). The level of the mycotoxin verrucarol (produced by Stachybotrys chartarum) in swab samples was positively associated with tiredness (p = 0.04). Streptomyces DNA in swab samples (p = 0.03) and Petri dish samples (p = 0.03) were negatively associated with tiredness. In conclusion, total fungal contamination, measured as total fungal DNA) in the classrooms, Aspergillus versicolor and verrucarol can be risk factors for rhinitis and SBS symptoms among students in the tropical country Malaysia.     

Acetophenone and stilbene derivatives from Gnetum ula

The isolation of bergenin, 2-hydroxy-4-benzyloxyacetophenone and the related dimer and stilbene from Gnetum ula is reported.     

NK cells: An attractive candidate for cancer therapy

Natural killer (NK) cells have significant capability in tumor immune-surveillance. The ability of lyse transformed cells immediately in an antigen-independent manner make them an attractive candidate for cancer cell therapy. Despite employment of NK cells in cancer immunotherapy, clinical trials are faced with serious limitations such as trouble with the penetration of NK cells in tumor sites, limited in vivo persistence, and tumor microenvironment interference. Taken together, the NK-cell cancer therapy is still infant scenario that has a long way to be translated in clinic. Current article first reviews characteristic features of NK lymphocytes. Then, it discusses about important disruptive barriers and motivator in the developmental stages of NK cells like as tumor microenvironment. Finally, some revolutionary approaches are highlighted utilizing of NK cells in cancer therapy.