Active compounds in Populus nigra L. wilted leaves responsible for attracting Helicoverpa armigera (Hübner) (Lep., Noctuidae) and new agaropectin formulation

Abstract:  The leaf extracts of Populus nigra were collected and identified by steam distillation, air entrainment and gas chromatographic–mass spectrometric analysis. Electroantennograms were recorded from Helicoverpa armigera adults in response to the chemicals identified. Both aromatic compounds and green-leaf volatiles elicited strong responses. Field experiments revealed that the active compounds responsible for attracting H. armigera moths are mainly short-side-chain aromatic alcohols and aldehydes. We, for the first time, used agaropectin as the controlled-release matrix of insect attractants. A five-component lure containing all the aromatics without phenolics, mixed in the proportions as found in the steam distillate of the leaves collected in August, produced the best trap catch. The results showed that the volatiles of wilted leaves of P. nigra can attract H. armigera adults by feeding attraction.     

Pre‐copulation intervals,copulation frequencies,and initial progeny sex ratios in two biotypes of whitefly,Bemisia tabaci

The whitefly Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) is a species complex, and its systematic classification requires controlled crossing experiments among its genetic groups. Accurate information on pre‐copulation intervals, copulation frequencies, and initial frequency of egg fertilization of newly emerged adults is critical for designing procedures for collecting the virgin adults necessary for these experiments. In the literature, considerable variation is reported between B. tabaci populations, with respect to the length of the pre‐copulation interval and the initial frequency of egg fertilization. Here, we used a video‐recording method to observe continuously the copulation behaviour of the Mediterranean/Asia Minor/Africa (B biotype) and the Asia II (ZHJ1 biotype) groups of B. tabaci. We also recorded the initial frequency of egg fertilization, as determined by the sex of the progeny. When adults were caged in female–male pairs on leaves of cotton plants, the earliest copulation events occurred 2–6 h after emergence; at 12 h after emergence 56–84% of the females had copulated at least once, and nearly all (92–100%) had copulated at least once by 36 h after emergence. Both females and males copulated repeatedly. Approximately 80 and 20% of copulation events occurred during the photophase and scotophase, respectively. By 72 h post‐emergence, the females of the B and ZHJ1 biotypes had copulated on average 6.1 and 3.9 times, respectively. When adults were caged in groups on plants 1–13 h after emergence, 30–35% of the eggs deposited during this period were fertilized, and approximately 90% of females were fertilized by the end of the 13 h. Although timing of copulation differed in detail between the two genetic groups, the results demonstrate that B. tabaci adults can start to copulate as early as 2–6 h post‐emergence and the majority of females can become fertilized on the day that they emerge.     

BJ-HCC-20, a potential novel cancer-testis antigen.

In an effort to identify novel Cancer-Testis genes, we analyzed the sequence in the q26-28 region of human X chromosome by several on-line tools. The candidate sequences were then confirmed by experiments. We have obtained a novel Cancer-Testis gene, BJ-HCC-20. In vivo, it was found to have two isoforms. In samples of liver, colon, gastric and lung cancer tested, the expression frequency of BJ-HCC-20 is 25%, 17%, 21% and 15%, respectively. Full-length cDNAs of both BJ-HCC-20 isoforms were isolated and their gene structures and promoter regions were characterized. BJ-HCC-20 might have implications in theoretical and practical tumor biology.     

Estrogen carcinogenesis in Syrian hamster tissues: role of metabolism

Evidence for a role of estrogen metabolism in hormonal carcinogenesis was obtained with the Syrian hamster as an in vivo model system. Both natural and synthetic estrogens are capable of inducing a high incidence of renal carcinomas in this species. A high incidence of hepatocellular carcinomas can also be induced in the hamster with synthetic estrogens such as ethinyl estradiol or diethylstilbestrol, provided alpha-naphthoflavone (ANF) is present in the diet. Although steroid receptor-mediated hormonal events appear to be intimately involved in the process of in vivo cell transformation of both tissues, certain observations strongly suggest that nonhormonal events are also important. Despite their potent estrogenic activity at the doses used, ethinyl estradiol and alpha-zearalanol induce relatively low renal tumor incidences after 9.0 and 10.0 months of continuous treatment, respectively. A role for the metabolism of estrogens to reactive intermediates is also suggested by studies showing estrogen-induced renal tumorigenesis can be partially inhibited by concomitant administration of ANF or ascorbic acid. Consistent with this is the general correlation between the amount of catechol estrogen formed by a compound, as mediated by estrogen 2-/4-hydroxylase, and renal carcinogenicity data. Recently, additional supporting evidence has been obtained from studies involving the irreversible binding of reactive metabolites of steroidal or stilbene estrogens to hamster liver microsomal proteins.     

Occurrence of ceramide-glycanase in the earthworm, Lumbricus terrestris

We have detected the presence of ceramide-glycanase in the earthworm, Lumbricus terrestris. We have also devised a simple method for the preparation of this enzyme from the earthworm. This enzyme cleaved the linkage between the ceramide and the glycan chain in LacCer, GbOse3Cer, GbOse4Cer, GbOse5Cer, GM3, GM2, GM1 and GD1a. By using tritium-labeled GM2 as substrate, the optimum pH of this enzyme was found to be between pH 4 and 4.5. In the earthworm, the ceramide-glycanase was mainly found in the muscle. The intestine was found to contain a very low level of this enzyme. Because of their easy availability, earthworms should become a convenient source for the preparation of ceramide-glycanase.     

N-Deacetylation of 2-acetamido-2-deoxy-hexosecontaining oligosaccharides and polysaccharides by calcium in liquid ammonia

N-Deacetylation of 2-acetamido-2-deoxy-hexose residues is accomplished in liquid ammonia containing calcium. Oligosaccharides, lacto-N-fucopentaose II and lacto-N-difucohexaose I, containing 3,4-disubstitutedN-acetylhexosamine residues are quantitativelyN-deacetylated. When applied to polysaccharides, however, only partialN-deacetylation was achieved.Author for correspondence. AXRD     

Cyclosporin treatment of IgA nephropathy: a short term controlled trial.

Cyclosporin''s known regulatory effects on the immune system suggest that it may be useful in treating patients with IgA nephropathy. A randomised prospective single blind study of 19 patients with IgA nephropathy and proteinuria (greater than 1.5 g/day) was conducted to determine the therapeutic value of cyclosporin. The patients were divided into two groups: nine patients were given oral cyclosporin (5 mg/kg/day) for 12 weeks and 10 patients a placebo. The two groups were comparable in age of presentation, ratio of men to women, plasma creatinine and serum IgA concentrations, creatinine clearance, daily urinary protein excretion, severity of renal histopathological changes, and prevalence of hypertension. A significant reduction of proteinuria and an increase of plasma albumin concentration was observed with treatment with cyclosporin. Nevertheless, a significant rise of plasma creatinine concentration and a fall in creatinine clearance was found in patients after six weeks'' treatment with cyclosporin, although the plasma cyclosporin concentrations were maintained within a narrow therapeutic range. Serum IgA concentrations were reduced in seven patients. Renal function improved within eight weeks after treatment was stopped. Three months after treatment was stopped proteinuria remained less than half of the pretreatment values in three patients. No similar biochemical changes were observed in the controls. Short term cyclosporin therapy may be beneficial in reducing proteinuria in some patients with IgA nephropathy. As transient renal impairment was seen, despite cyclosporin concentrations being maintained within a narrow therapeutic range, indiscriminate use of cyclosporin in glomerulonephritis should be discouraged.     

The study of binding of the virG gene product with the virD gene promotor region of the Agrobacterium tumefaciens Ti-plasmid C58

The 1.5 kb EcoRI--HindIII fragment of the pTiC58 containing the virD regulatory sequence demonstrates a constitutive promoter activity in E. coli background and an inducible one in agrobacterium. The virG gene was cloned in pTZ19R plasmid. To reveal the virG product--virD regulatory sequence interaction a few protein fractions of E. coli harbouring the obtained recombinant plasmid pTZ19G lysate were used. PAGE-retardation assay revealed the specific binding between the 1.5 kb DNA fragment containing 5'-end of virD and a separate protein fraction of the bacterial lysate.     

Roles of prepubertal androgen, estrogen or androgen plus prolactin on androgen-induced proliferative response of seminal vesicles in adult mice

Male mice castrated on day 0 after birth were pretreated daily with testosterone propionate (TP, 4 micrograms/g body weight), 17 beta-estradiol (E2, 0.2 micrograms/g body weight) or vehicle for 21 days starting from day 20. In another experiment, male mice were castrated on day 25; two pituitaries from 60-day-old females were immediately grafted under the capsule of the left kidney in one group. The castrated mice with or without grafts were pretreated daily with TP (4 or 20 micrograms/g body weight) for 36 days starting from day 25, and the left kidney was removed on day 60. Daily TP injections (4 micrograms/g body weight) were started again at 30 days after the end of pretreatments to examine androgen-induced proliferation, and incorporation of 5-[125I]iodo-2'-deoxyuridine into the whole seminal vesicles was used as an index of proliferation. In the neonatally castrated mice, both TP and E2 pretreatments given during the prepubertal period significantly increased seminal vesicle weight even long after the end of the pretreatments. However, androgen-induced proliferative response found in the neonatally castrated adult mice (poor response; long duration with a low peak) was changed to that found in mice castrated at adulthood (good response; short duration with a high peak) by the TP pretreatment only but not at all by the E2 pretreatment. In the mice castrated on day 25, a pharmacological dose of TP or TP plus hyperprolactin could not enhance or change the adult castration type of androgen-induced proliferation induced by physiological prepubertal androgens, although both treatments significantly enhanced the prepubertal growth of the seminal vesicles.     

Superoxide dismutase amplifies dye photosensitized production of desferal free radical: an electron spin resonance study

Desferal free radical (DFFR) photogenerated from dye sensitization was studied by electron spin resonance. When irradiated at the visible maximum in the presence of O2, both rose bengal and riboflavin sensitized the oxidation of Desferal (DF) and generated the DFFR. The yield of DFFR was amplified by superoxide dismutase (SOD). The SOD enhancement was attributed to the inhibition of superoxide-induced DFFR destruction. Similar SOD enhancement was observed with dyes Rhodamine 123 and Gentian Violet. Our studies suggest that when Desferal is used as a chelating agent in the presence of SOD, systems involving O2- could face interference from DFFR even at concentrations as low as 10 microM DF. DFFR may interfere with the chain reaction of lipid peroxidation resulting in an apparent protective action which, in fact, has very little to do with chelating the catalytic iron.