Japanese barberry seed predation by Rhagoletis meigenii fruit flies harboring Wolbachia endosymbionts

The phytophagous fruit fly Rhagoletis meigenii harbors the bacterium Wolbachia pipientis and, together with Japanese barberry, form a tri-partite symbiosis. R. meigenii is a seed predator of invasive Japanese barberry plants and is dependent on this insect-plant interaction for reproductive success. The endosymbiotic bacterium W. pipientis is a reproductive parasite known to alter the sex ratios of offspring and the fitness of infected host insects. We investigated Japanese barberry fruit for the degree of infestation by R. meigenii and characterized the Wolbachia strain infecting R. meigenii. Densities of R. meigenii in four naturalized stands of Japanese barberry revealed low numbers of fruit flies with high variability in the population densities observed among individual plants. Overall, R. meigenii infested roughly 10–20 % of the Japanese barberry fruits analyzed; fruit with two seeds (vs. one seed) were the most frequently infested. Approximately, 90 % of the R. meigenii tested positive for Wolbachia infection via PCR amplification of the Wolbachia surface protein (wsp) gene. No bacterial strain diversity was observed when comparing multi-locus sequence typing (MLST) profiles within or among five R. meigenii populations in Maine, although the MLST profile obtained from R. meigenii differed from three co-occurring Rhagoletis. The Wolbachia endosymbiont of R. meigenii is a member of the Wolbachia supergroup A and the ST-13 cluster complex.     

Reversal of lovastatin-mediated inhibition of natural killer cell cytotoxicity by interleukin 2

The activation of human natural killer (NK) cell cytotoxicity by interleukin 2 (IL-2) is well established, although the biochemical mechanisms of this stimulation have not yet been fully delineated. Earlier, we reported that treatment of NK cells with an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase such as compactin or lovastatin significantly abrogates the in vitro killing of a susceptible human erythroleukemic cell line and that this inhibition can be completely reversed by 2 hr of exposure to mevalonate (J. Cell. Physiology 139:550-557, 1989). We report here that 24 hr of treatment with IL-2 also reverses lovastatin inhibition of NK cell function. In addition to natural cytotoxicity, IL-2 also restores chemotactic and antibody dependent cellular cytotoxicity functions to lovastatin-treated cells. IL-2 does not stimulate proliferation of these cells during this time period, nor does it affect the phenotypic composition of the NK cell preparations. Although IL-2 was able to reverse the lovastatin-mediated inhibition of every cell function we examined, it had no effect on the inhibition of cholesterol biosynthesis as measured by [3H]acetate incorporation into non-saponifiable lipids, nor did it stimulate HMG CoA reductase activity. These findings support the hypothesis that there is a non-sterol isoprenoid product which is required for NK cell cytotoxicity and chemotaxis. In addition, the data suggest that IL-2 stimulation of NK cells proceeds by an isoprenoid-independent pathway.     

Immunohistochemical study of the developing endocrine pancreas of the opossum (Didelphis virginiana)

Cells immunoreactive for insulin, glucagon, somatostatin, bovine pancreatic polypeptide and 5-hydroxytryptamine are found in the pancreas of the newborn opossum and of all later stages examined. All immunoreactive cell types are present in primary and secondary islets and within elements of the exocrine pancreas. Cells immunoreactive for glucagon, bovine pancreatic polypeptide, somatostatin and 5-hydroxytryptamine generally are confined to the periphery of secondary (intralobular) islets, whereas insulin-immunoreactive cells occupy the central region. Endocrine cells within primary (interlobular) islets are randomly scattered. A small number of pancreatic-polypeptide-immunoreactive cells are reactive for the amine 5-hydroxytryptamine also, but the reverse is not observed. The endocrine pancreas continues to differentiate and develop throughout postnatal life and into adulthood. Little difference was observed between the head and tail regions of the opossum pancreas for the measurements made.     

SSCP analysis of the tyrosine kinase domain of the insulin receptor gene: Polymorphisms detected in South African black and white subjects

The frequency of DNA polymorphisms in the tyrosine kinase domain (exons 17–21) of the insulin receptor gene was assessed in 30 black and 30 white South Africans, using single-stranded conformation polymorphism and direct sequencing analysis. A comparison of the frequencies of the normal versus the combined polymorphic alleles, found only in exon 17, showed a significant difference between black and white groups (P = 0.037). Received: 25 May 1995 / Revised: 1 September 1995     

Combining industrial ecology tools to assess potential greenhouse gas reductions of a circular economy: Method development and application to Switzerland

Industrial ecology (IE) methodologies, such as input/output or material flow analysis and life cycle assessment (LCA), are often used for the environmental evaluation of circular economy strategies. Up to now, an approach that utilizes these methods in a systematic, integrated framework for a holistic assessment of a geographic region's sustainable circular economy potential has been lacking. The approach developed in this study (IE4CE approach) combines IE methodologies to determine the environmental impact mitigation potential of circular economy strategies for a defined geographic region. The approach foresees five steps. First, input/output analysis helps identify sectors with high environmental impacts. Second, a refined analysis is conducted using material flow and LCA. In step 3, circular strategies are used for scenario design and evaluated in step 4. In step 5, the assessment results are compiled and compared across sectors. The approach was applied to a case study of Switzerland, analyzing 8 sectors and more than 30 scenarios in depth. Carbon capture and storage (CCS) from waste incineration, biogas and cement production, food waste prevention in households, hospitality and production, and the increased recycling of plastics had the highest mitigation potential. Most of the scenarios do not influence each other. One exception is the CCS scenarios: waste avoidance scenarios decrease the reduction potential of CCS. A combination of scenarios from different sectors, including their impact on the CCS scenario potential, led to an environmental impact mitigation potential of 11.9 Mt CO₂-eq for 2050, which equals 14% of Switzerland's current consumption-based impacts.     

Antiproliferative Activity and Ultrastructural Changes in Promastigote and Amastigote forms of Leishmania amazonensis Caused by Limonene-Acylthiosemicarbazide Hybrids

Leishmaniasis is a tropical zoonotic disease. It is found in 98 countries, with an estimated 1.3 million people being affected annually. During the life cycle, the Leishmania parasite alternates between promastigote and amastigote forms. The first line treatment for leishmaniasis are the pentavalent antimonials, such as N-methylglucamine antimoniate (Glucantime®) and sodium stibogluconate (Pentostam®). These drugs are commonly related to be associated with dangerous side effects such as cardiotoxicity, nephrotoxicity, hepatotoxicity, and pancreatitis. Considering these aspects, this work aimed to obtain a new series of limonene-acylthiosemicarbazides hybrids as an alternative for the treatment of leishmaniasis. For this, promastigotes, axenic amastigotes, and intracellular amastigotes of Leishmania amazonensis were used in the antiproliferative assay; J774-A1 macrophages for the cytotoxicity assay; and electron microscopy techniques were performed to analyze the morphology and ultrastructure of parasites. ATZ−S-04 compound showed the best result in both tests. Its IC₅₀, in promastigotes, axenic amastigotes and intracellular amastigotes was 0.35±0.08 μM, 0.49±0.06 μM, and 15.90±2.88 μM, respectively. Cytotoxicity assay determined a CC₅₀ of 16.10±1.76 μM for the same compound. By electron microscopy, it was observed that ATZ−S-04 affected mainly the Golgi complex, in addition to morphological changes in promastigote forms of L. amazonensis.     

Use of oligonucleotides to define the site of interstrand cross-links induced by Adriamycin.

It has been known for several years that Adriamycin forms adducts and interstrand cross-links when reacted for long periods of time with bacterial and mammalian DNA in vitro, with the cross-link being restricted to 2 bp elements containing GpC sequences. The self-complementary 20mer deoxyoligonucleotide TA4T4GCA4T4A has been used in this study as a model of the apparent G-G cross-linking site at GpC sequences. The rate of formation of cross-links, as well as the dependence on both Adriamycin and Fe(III) concentration, were similar with this oligonucleotide as compared with calf thymus DNA. The cross-linking was demonstrated on both denaturing and non-denaturing sequencing gels. The half-life of the G-G cross-link was 40 h, consistent with that implied with high molecular weight, heterogeneous sequence DNA. Exonuclease III digests of adducts formed with 20mer deoxyoligonucleotides containing single, central G-G, G-I and I-I potential cross-links revealed that a guanine residue is required at both ends of the cross-link. No cross-linking was observed with a similar oligonucleotide containing only a single central (G.C) bp.