Electroantennogram responses of the oriental fruit fly, Dacus dorsalis, to a spectrum of alcohol and aldehyde plant volatiles

Electroantennograms (EAGs) were recorded from unmated, laboratory-reared, male and female oriental fruit flies, Dacus dorsalis, in response to a range of between C₁ and C₁₂ carbon chain-length saturated and unaturated aliphatic alcohols and aldehydes, most all of which are known host-plant volatiles. Only two of the 35 compounds tested elicited significantly larger EAGs from female than male antennae. For the two functional-group series tested, aldehydes elicited responses greater than or equal to the responses to the alcohols. In general, the unsaturated alcohols did not elicit responses significantly different from the saturated alcohols. However, the unsaturated aldehydes, (E)-2-hexenal and 10-undecenal, elicited larger amplitude EAGs than their saturated analogs. EAGs were significantly greater for a particular carbon chain-length, with responsiveness to primary alcohols peaking at C₆ and aldehydes peaking at C₇. The (E)-2- monoenic alcohols peaked at C₆, while the (E)-3-alcohols plateaued between C₅ and C₈. The greatest EAG responses of all compounds tested were elicited by the saturated and unsaturated C₆ alcohols and aldehydes which are constitutents of the general green-leaf volatile complex that emanates from most plants. The potential adapative benefit of selective sensitivity to green-leaf volatiles is discussed in regards to foraging behaviors of oriental fruit flies.

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Résumé Des électroantennogrammes (EAG) ont enregistré les réponses, en élevages de femelles et mâles vierges de Dacus dorsalis, à une gamme de chaînes de carbones de C₁ à C₁₂ saturés et non-saturés d'alcools aliphatiques et d'aldéhydes, dont beaucoup sont connus comme substances volatiles des végétaux. Seulement 2 des 35 composés examinés ont provoqué des EAG significativement plus importants chez les femelles que chez les mâles. Pour les séries des deux groupes fonctionnels examinés, les aldéhydes ont provoqué des réponses supérieures ou égales aux alcools. En général, les réponses aux alcools nonsaturés n'étaient pas significativement différentes des réponses aux alcools saturés. Cependant, les aldéhydes non-saturés, (E)-2-hexénal et 10-undécénal, ont induit des EAG de plus grande ampleur que leurs analogues saturés. Les EAG étaient significativement les plus importants pour une chaîne de longueur particulière, la réponse aux alcools primaires culminant en C₆ et les aldéhydes en C₇. Les alcools monoéniques (E)-2- culminaient en C₆, tandis que les alcools (E)-3- étaient étales entre C₅ et C₈. Les EAG les plus importants ont été obtenus pour tous les composés examinés avec les alcools et aldéhydes en C₆ qui appartiennent à l'odeur verte complexe émise par beaucoup de plantes. Le bénéfice adaptatif potentiel de la sensibilité sélective à l'odeur verte des feuilles est examinée en fonction du comportement de prospection de D. dorsalis.

     

Expression of HLA-DR antigens on tumour cells does not contribute to skin reactivity to autologous cholesteryl hemisuccinate (CHS)-treated tumour cells in patients with metastatic melanoma

Summary Skin tests with autologous cholesteryl hemisuccinate (CHS)-treated and untreated cells were performed in ten metastatic melanoma patients. In the majority of cases evident reaction was noted with CHS-treated cells (9/10) while the reaction with untreated cells was mostly negative (7/10). Tumour cell suspensions used for skin tests were characterized for reactivity with monoclonal antibody TAL 1B5 detecting the HLA-DR alpha chain. There were no differences between CHS-treated and untreated cells with respect to HLA-DR expression and no correlation was found between grade of skin reaction to CHS-treated cells and the proportion of HLA-DR positive cells in the injected cell sample.     

Electroantennogram responses of the Mediterranean fruit fly, Ceratitis capitata to identified volatile constituents from calling males

Fifty-six compounds from the odor of calling, sexually mature, laboratory reared males of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) were isolated by headspace trapping on Tenax columns and identified using GC/MS techniques (69 total compounds were detected). Electroantennogram responses (EAGs) to 54 of the 56 identified compounds as well as 5 analogs were tested on both sexes. Significant differences between the sexes in their responsiveness were found in 9 of the 54 identified compounds tested. There was no correlation between the amplitude of the EAG response and the relative abundance of compound identified from headspace analysis. Of the five major identified components, three elicited relatively small EAG responses, while two elicited large EAGs compared to the hexan-1-ol standard. The relative ranking of EAG responses were: methyl and ethyl hexenoates and hexanoates > C₄–C₆ esters and/or acetates > ethyl and methyl octenoates > monoterpenes > sesquiterpenes > C₂–C₅ acetates, alcohols and ketones. Behavioral bioassays on each of the five major identified components as well as a blend of six of the compounds showed some degree of attractancy to virgin females which in some cases approached the response to a pheromonal standard (male odors absorbed onto filter paper). These results are discussed in relationship to the insect's antennal sensitivity to putative pheromone components and/or allomonal components and to other reported C. capitata pheromone studies.

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Résumé Cinquante-six composés de l'odeur de mâles de C. capitata Weidemann, élevés en laboratoire, sexuellement mûrs et en appel, ont été isolés par piégeage sur colonnes tenax et identifiés par la technique GC/MS (69 composés avaient été détectés en tout). Les électroantennogrammes (EAGs) ont été examinés chez les deux sexes pour 54 des 56 composés identifiés et 5 de leurs analogues. Des différences significatives entre les sexes ont été observées pour 9 des 54 composés identifiés. Il n'y avait pas de corrélation entre l'ampleur de l'EAG et l'abondance relative du composé lors de son isolement. Pour les 5 principaux composés identifiés, 3 ont induit des EAGs relativement faibles, tandis que 2 étaient importants, par comparaison avec l'Hexane-1-ol utilisé comme témoin. Le classement relatif des EAG a été: hexénoates et hexanoates d'éthyl et de méthyl C₄–C₆ esters et/ou acétates octénoates d'éthyl ou de méthyl monoterpènes sesquiterpènes C₂–C₅ acétates, alcools et kétones. Les expériences de comportement avec chacun des 5 composés principaux identifiés, comme avec des mélanges de 6 composés ont mis en évidence une attraction des femelles vierges qui dans quelques cas avoisine la réponse à la phéromone témoin (odeur du mâle absorbée sur papier filtre). Ces résultats sont discutés en fonction de la sensibilité de l'antenne d'insexte aux composés supposés de la phéromone et aux composés allomonaux, et en fonction des autres études connues sur les phéromones de C. capitata.

     

Thiosulfate production from cystine by the keratinolytic prokaryote Streptomyces fradiae

In cultures of Streptomyces fradiae on wool as the only source of nutrition inorganic thiosulfate (in amounts up to 0.5 mg of Na₂S₂O₃·5 H₂O/ml) was formed as the final product of metabolization of sulfur from cystine of keratin proteins. The presence of thiosulfate was proved by qualitative tests and thin-layer chromatography and estimated quantitatively by spectrophotometry, titrimetry, and capillary isotachophoresis. Metabolization of organic sulfur to thiosulfate excreted into the medium is a process not yet described in microorganisms.     

The effects of external electric field on the electron transport system of spinach chloroplasts

Since the thylakoid membranes of an active chloroplast are constantly exposed to the electric fields generated by the electron transport system inside the membranes, we have studied the effects of pretreating chloroplasts of spinach ( Spinacia oleracea L.) leaves with an external AC (alternating current) electric field on their electron transport system. It was found that a few minutes electric field pretreatment (333 V cm^-1 across chloroplast samples), especially at low frequency, irreversibly inhibited the activity of photosystem II (PSII), but under certain conditions, stimulated that of photosystem I (PSI). From the measurements of fluorescence from PSII, we ascribe the inhibition to a lesion close to its reaction center P680, leading to increased dissipation of excitation energy to heat. The effect on PSI was investigated by the reduction of its reaction center, P700 by various artificial donors. We suggest that the stimulative effect can be attributed to a positive shift of the surface charge density of thylakoid membranes that brings about an increase in the accessibility of exogenous electronegative donors.     

TPA对原代白血病细胞的诱导分化作用

本文报告了TPA对32例不同类型白血病细胞的体外分化诱导结果。TPA(1.6×10~-7M)可诱导急性非淋巴细胞(ANLL)白血病细胞迅速出现单核巨噬细胞分化标志:细胞贴壁、胞浆丝状伪足形成,具有类似巨噬细胞的形态改变及相应的细胞化学反应特征。急性淋巴细胞白血病(ALL)和桨细胞白血病(PCL)细胞不发生上述变化,表现为细胞聚集成闭现象。慢性淋巴细胞白血病(CLL)出现桨细胞样形态转化。初发与复发病例的诱导反应相类似。TPA体外诱导分化实验,有助于了解病人白血病细胞的分化潜能,对于鉴别粒单系和淋巴系两类白血病,尤其对于用常规方法分型困难的低分化白血病有一定的临床诊断意义。     

Supplement of nutrients for effective cultivation of hepatitis B surface antigen-producing recombinant yeast

Summary In the hepatitis B surface antigen (HBsAg)-producing recombinant yeast culture medium, the supply of Bacto-yeast nitrogen base without amino acids was found to be inadequate due to the lack of the several kinds of vitamins and trace elements. When the culture medium for this recombinant yeast was supplemented with sufficient vitamins and trace elements, its growth, HBsAg production and the stability of plasmid were improved.