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1.
J Environ Manage ; 359: 120962, 2024 May.
Article in English | MEDLINE | ID: mdl-38677229

ABSTRACT

Low-water-level regulation has been effectively implemented in the restoration of urban river sediments in Guangzhou City, China. Further investigation is needed to understand the microbial mechanisms involved in pollutant degradation in low-water-level environments. This study examined sediment samples from nine rivers, including low-water-level rivers (LW), tidal waterways (TW), and enclosed rivers (ER). Metagenomic high-throughput sequencing and the Diting pipeline were utilized to investigate the microbial mechanisms involved in sediment C/N/S geochemical cycling during low-water-level regulation. The results reveal that the degree of pollution in LW sediment is lower compared to TW and ER sediment. LW sediment exhibits a higher capacity for pollutant degradation and elimination of black, odorous substances due to its stronger microbial methane oxidation, nitrification, denitrification, anammox, and oxidation of sulfide, sulfite, and thiosulfate. Conversely, TW and ER sediment showcase greater microbial methanogenesis, anaerobic fermentation, and sulfide generation abilities, leading to the persistence of black, odorous substances. Factors such as grit and silt content, nitrate, and ammonia concentrations impacted microbial metabolic pathways. Low-water-level regulation improved the micro-environment for functional microbes, facilitating pollutant removal and preventing black odorous substance accumulation. These findings provide insights into the microbial mechanisms underlying low-water-level regulation technology for sediment restoration in urban rivers.


Subject(s)
Geologic Sediments , Rivers , Geologic Sediments/microbiology , Nitrogen/analysis , Carbon , China
2.
Sci Total Environ ; 881: 163464, 2023 Jul 10.
Article in English | MEDLINE | ID: mdl-37062316

ABSTRACT

Phytoremediation is considered an effective technology for remediating antibiotic-contaminated water; however, its underlying mechanisms remain poorly understood. Therefore, this study investigated the phytoremediation potential of fluoroquinolone antibiotics (FQs) by different wetland plant species. The phytoremediation rates of ΣFQs were 46-69 %, and rhizosphere microorganism degradation (accounting for 90-93 %) dominated the FQ removal over that of plant uptake and hydrolysis. Dissipation of the FQs in the hydroponic system followed a first-order kinetic model. The joint action of the more powerful absorptive capacity of plants and stronger microbial degradation ability in the rhizosphere was the reason that Cyperus papyrus showed significantly higher FQ phytoremediation rates than the other three plant species, which implied that the plant species is a critical factor affecting phytoremediation efficiency. The FQ distribution in plant tissues decreased from root > stem > leaf, suggesting that FQs were more concentrated in the roots than in the aboveground tissues. Negative correlations between the diffusive gradient in thin films and root concentrations implied that these wetland plant species took up FQs mainly via active transport mechanism (requiring some vectors, perhaps via exudates); whereas, the process of root-to-stem transfer and upward transport represented passive transport, which mainly depended on transpiration. These results facilitate an improved understanding of phytoremediation processes and improve their future applications.


Subject(s)
Soil Pollutants , Wetlands , Biodegradation, Environmental , Biological Availability , Plants/metabolism , Anti-Bacterial Agents/metabolism , Fluoroquinolones/metabolism , Soil Pollutants/analysis
3.
Insects ; 13(9)2022 Aug 26.
Article in English | MEDLINE | ID: mdl-36135474

ABSTRACT

Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) is a widely used tool for measuring gene expression; however, its accuracy relies on normalizing the data to one or more stable reference genes. Eocanthecona furcellata (Wolff) is a polyphagous predatory natural enemy insect that preferentially feeds on more than 40 types of agricultural and forestry pests, such as those belonging to the orders Lepidoptera, Coleoptera, and Hymenoptera. However, to our knowledge, the selection of stable reference genes has not been reported in detail thus far. In this study, nine E. furcellata candidate reference genes (ß-1-TUB, RPL4, RPL32, RPS17, RPS25, SDHA, GAPDH2, EF2, and UBQ) were selected based on transcriptome sequencing results. The expression of these genes in various samples was examined at different developmental stages, in the tissues of male and female adults, and after temperature and starvation treatments. Five algorithms were used, including ΔCt, geNorm, NormFinder, BestKeeper, and RefFinder, to evaluate reference gene expression stability. The results revealed that the most stable reference genes were RPL32 and RPS25 at different developmental stages; RPS17, RPL4, and EF2 for female adult tissue samples; RPS17 and RPL32 for male adult tissue samples; RPS17 and RPL32 for various temperature treatments of nymphs; RPS17 and RPS25 for nymph samples under starvation stress; and RPS17 and RPL32 for all samples. Overall, we obtained a stable expression of reference genes under different conditions in E. furcellata, which provides a basis for future molecular studies on this organism.

4.
Genomics ; 114(6): 110472, 2022 11.
Article in English | MEDLINE | ID: mdl-36055573

ABSTRACT

Toxoptera aurantii Boyer de Fonscolombe (Hemiptera: Aphididae) can attack many plant hosts, including tea (Camellia sinensis L.), citrus (Citrus spp.), lychee (Litchi chinensis Sonn.), banana (Musa spp.), and pineapple (Ananas comasus L.) among others. It is a widely distributed hexapod and one of the most destructive pests in tea plantations, causing enormous economic losses in tea production each year. A high-quality reference genome is important to study the phylogenetics and evolution of T. aurantii because its genome is highly heterozygous and repetitive. We obtained a de novo genome assembly of T. aurantii at the chromosome level using a combination of long Nanopore reads from sequencing with high-throughput chromosome conformation capture technology. When finally assembled, the genome was 318.95 Mb on four chromosomes with a 15.19 Mb scaffold N50. A total of 12,162 genes encoded proteins, while there were 22.01% repetitive sequences that totaled 67.73 Mb. Phylogenetic analyses revealed that T. aurantii and Aphis gossypii parted ways approximately 7.6 million years ago (Mya). We used a combination of long-read single-molecule sequencing with Hi-C-based chromatin interaction maps that resulted in a reference chromosomal level reference genome of T. aurantii that was high quality. Our results will enable the exploration of the genetics behind the special biological features of T. aurantii and also provide a source of data that should be useful to compare the compare genome among the Hemiptera.


Subject(s)
Aphids , Plants , Phylogeny , Aphids/classification , Aphids/genetics , Plants/parasitology
5.
Mitochondrial DNA B Resour ; 7(6): 908-910, 2022.
Article in English | MEDLINE | ID: mdl-35692658

ABSTRACT

In this study, we sequenced the complete mitogenome of Kentrochrysalis streckeri (Staudinger, 1880). The complete mitogenome sequence of K. streckeri is circular, 15,253 bp in size and contains 13 protein-coding genes (PCGs), two ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA) genes, and a control region (CR). Nucleotide composition was A + T biased, and all the PCGs exhibited a positive AT-skew, which was reflected in the nucleotide composition, codon, and amino acid usage. Most PCGs start with ATG or ATT and stop with TAA. However, COX1 gene starts with CGA and three genes (COX1, COX2, NAD5) use the incomplete stop codon T. Phylogenetic analyses showed that the relationship (K. streckeri+((Manduca sexta+Sphinx morio)+(Psilogramma increta+(Psilogramma menephron+Notonagemia analis scribae)))).

6.
Oncogene ; 41(5): 692-703, 2022 01.
Article in English | MEDLINE | ID: mdl-34819634

ABSTRACT

N6-methyladenosine (m6A), the most abundant mRNA modification in mammals, is involved in the metabolism of mRNA. KIAA1429 is regarded as the largest m6A methyltransferase and plays an important role in m6A modification. However, the prognostic value and function of KIAA1429 in colorectal cancer (CRC) are unclear. Quantitative real-time PCR and immunohistochemical assays were performed to evaluate the expression of KIAA1429 in CRC tissues. Kaplan-Meier survival curves and log-rank tests were used to assess the association between KIAA1429 expression and the prognosis of patients with CRC. CCK-8 assays, colony formation assays, cell cycle assays, and xenograft experiments were performed to investigate the effect of KIAA1429 on cell proliferation. RNA immunoprecipitation, methylated RNA immunoprecipitation assays, and RNA stability assays were conducted to explore the underlying mechanism. KIAA1429 was significantly upregulated in CRC tissues compared with adjacent normal tissues. Patients with higher expression of KIAA1429 had shorter overall survival than those with lower expression. Functionally, KIAA1429 promoted CRC cell proliferation in vitro and in vivo. Mechanistically, KIAA1429 negatively regulated the expression of WEE1 by decreasing its stability in an m6A-independent manner by binding to the third segment in the 3'-UTR of WEE1 mRNA. Moreover, butyrate decreased the expression of KIAA1429 by downregulating the level of the transcription factor NFκB1. Our findings indicated that KIAA1429 plays an oncogenic role in CRC cells by inhibiting the expression of WEE1 in an m6A-independent manner and is associated with poor survival in CRC patients. These results suggested that KIAA1429 might be a potential prognostic marker for CRC.


Subject(s)
Oncogenes
7.
Int J Med Sci ; 15(11): 1194-1202, 2018.
Article in English | MEDLINE | ID: mdl-30123057

ABSTRACT

Background: Chinese medicinal formula BNG-1, a non-specific inhibitor of phospho-diesterases (PDEs), can be considered as a potential anti-inflammatory agent. The present study was aimed at determining the effects of BNG-1 on the development of non-alcoholic fatty liver disease (NAFLD) in mice. Design and Methods: Male CD1 mice were randomly divided into seven groups, the control Con (4) and Con (8)+saline groups were fed a standard control diet for four or eight weeks; the experimental HFD (4) and HFD (8)+saline groups were fed a high fat diet for four or eight weeks; the HFD (8)+LBNG, HFD (8)+MBNG, and HFD (8)+HBNG groups received a high fat diet along with low, moderate or high doses of BNG-1 (0.026, 0.035, and 0.052g/30g body weight) which was administered for the last four weeks of an eight-week experimental period. After the end of experiment, blood and tissue samples were taken and analyzed. Results: Mice in the HFD (4) group had higher levels of alanine aminotransferase (ALT), plasma and hepatic triglyceride and cholesterol, and homeostasis model assessment-estimated insulin resistance (HOMA-IR) compared with mice in the Con (4) group. Mice receiving the high fat diet along with the BNG-1 supplement had decreased body weight gains and lower visceral fat weights compared with the HFD (8)+saline group. They had also significantly reduced levels of abnormal ALT and HOMA-IR, and improved blood lipid profile. BNG-1-treated mice exhibited reduced hepatic lipid accumulation, lower oxidative stress, and decreased expression of pro-inflammatory cytokines (TNF-α and IL-1ß). Furthermore, BNG-1 treatment resulted in down-regulation of hepatic cyclic-AMP dependent PDE3B and up-regulation of PDE3B expression in epididymis adipose tissue. Conclusions: BNG-1 mediated changes in PDE3B expression along with reduction in oxidative stress and inflammation. BNG-1 may ameliorate insulin resistance and hepatic steatosis in the NAFLD mouse model.


Subject(s)
Cyclic Nucleotide Phosphodiesterases, Type 3/metabolism , Drugs, Chinese Herbal , Insulin Resistance , Non-alcoholic Fatty Liver Disease , Animals , Diet, High-Fat , Liver , Male , Mice , Mice, Inbred C57BL , Taiwan
8.
Org Biomol Chem ; 16(15): 2688-2696, 2018 04 18.
Article in English | MEDLINE | ID: mdl-29582023

ABSTRACT

An enantiospecific [3 + 2] annulation of γ-butyrolactone fused cyclopropanes with aromatic aldehydes was realized under Lewis acid catalysis. This method provides facile access to a series of chiral furanolignan derivatives bearing multiple contiguous stereogenic centers in good-to-excellent yields, exclusive diastereoselectivities and excellent enantiopurities under mild reaction conditions. Elaboration work on the product of this reaction delivers stereoisomeric analogues of (+)-virgatusin and suggests a structural revision might be necessary for a previously reported isolated natural product.

9.
Insect Sci ; 25(6): 1025-1034, 2018 Dec.
Article in English | MEDLINE | ID: mdl-28485823

ABSTRACT

The stylet penetration behavior of aphids when feeding on plants is associated with virus acquisition and inoculation. Aphidius gifuensis (Ashmead) is a primary endoparasitoid of Myzus persicae (Sulzer) which is the most efficient vector of plant viruses. Information about the effects of parasitoid on aphid and virus transmission can provide an essential foundation for designing effective biological control strategies. This study aimed to investigate the effects of A. gifuensis on the feeding behavior and potato virus Y (PVY) transmission ability of M. persicae. The results showed that after M. persicae was parasitized by A. gifuensis, the duration of the first probe significantly decreased. Additionally, A. gifuensis exerted remarkable effects on aphid feeding in phloem ingestion. The contribution of the E1 waveform to the phloem phase was significantly higher in all parasitized aphids than in the control group. Although the time of infestation increased for parasitized aphids, the total duration of phloem sap ingestion decreased. Interestingly, the percentage of time M. persicae spent in the xylem and phloem phases only changed significantly on day 5. The percent transmission of PVY by the aphids parasitized on day 5 was lower than that in the control, but no significant differences were detected. The significance of this work is the demonstration that A. gifuensis can impede the feeding behavior of M. persicae, which sheds light on the biological basis of A. gifuensis as a natural enemy, but unfortunately does not provide an immediate solution for disrupting the transmission of PVY.


Subject(s)
Aphids/physiology , Aphids/parasitology , Feeding Behavior , Insect Vectors/physiology , Potyvirus , Animals , Aphids/virology
10.
Org Lett ; 18(8): 1784-7, 2016 Apr 15.
Article in English | MEDLINE | ID: mdl-27015144

ABSTRACT

An efficient palladium-catalyzed alkylation of electron-deficient polyfluoroarenes is described. The protocol provides a useful and operationally simple access to a broad scope of alkylated polyfluoroarene derivatives in moderate to excellent yields. This also represents the first example of the introduction of a polyfluoroarene structure involving an alkylpalladium(II) intermediate.

11.
Zhongguo Zhong Yao Za Zhi ; 40(11): 2191-4, 2015 Jun.
Article in Chinese | MEDLINE | ID: mdl-26552179

ABSTRACT

To observe the effect of Ligusticum wallichii-containing serum on the expressions of Toll-like receptor 4 and myeloid differentiation factor 88 in hepatic stellate cells. Clean-grade SD rats were randomly divided into 5 groups and orally given L. wallichii decoction, colchicine and normal saline for 7 d to prepare L. wallichii-containing serums. Except for the blank group, all of the remaining groups were stimulated with LPS 1 mg x L(-1) for 24 h. After being intervened, the L. wallichii-containing serums were cultured in 5% CO2 incubator at 37 degrees C for 24 hours. The expression of TLR4 and MyD88 were detected by RT-PCR and Western blot. After HSC was stimulated with LPS, TLR4 and MyD88 mRNA and protein expressions were significantly higher than the blank control group (P < 0.01). After being intervened with L. wallichii-containing serum, TLR4 and MyD88 mRNA and protein expressions were notably lower than the model group (P < 0.05 or P < 0.01). In conclusion, L. wallichii-containing serum could regulate the TLR4 signaling pathway and show the anti-fibrosis effect by inhibiting the expression of TLR4 and MyD88 in LPS-induced HSCs.


Subject(s)
Hepatic Stellate Cells/drug effects , Ligusticum , Myeloid Differentiation Factor 88/genetics , Toll-Like Receptor 4/genetics , Animals , Female , Hepatic Stellate Cells/metabolism , Lipopolysaccharides/pharmacology , Liver Cirrhosis, Experimental/drug therapy , Myeloid Differentiation Factor 88/physiology , Phytotherapy , RNA, Messenger/analysis , Rats , Rats, Sprague-Dawley , Toll-Like Receptor 4/physiology
12.
Chem Commun (Camb) ; 51(94): 16798-801, 2015 Dec 07.
Article in English | MEDLINE | ID: mdl-26434539

ABSTRACT

The first palladium-catalyzed dearomative cyclization via a modified Catellani-type C-H functionalization has been realized. The new strategy led to a series of spiroindolenine derivatives bearing an all-carbon quaternary spirocenter from simple aryl halides and substituted indoles.

13.
Chem Commun (Camb) ; 51(38): 8031-3, 2015 May 11.
Article in English | MEDLINE | ID: mdl-25882692

ABSTRACT

The first palladium-catalyzed ring opening of norbornene to prepare methylenecyclopentane derivatives has been established. The process, which uses readily available aryl iodides, tosylhydrazones and norbornene as starting materials, likely takes place via tandem Heck-type coupling, palladium carbene migratory insertion, C-C bond cleavage and the ß-hydride elimination pathway in a single synthetic sequence.

14.
Carbohydr Polym ; 122: 428-36, 2015 May 20.
Article in English | MEDLINE | ID: mdl-25817687

ABSTRACT

The rhizomes of Smilax glabra have been used as both food and folk medicine in many countries for a long time. However, little research has been reported on polysaccharides of S. glabra. In the present study, two polysaccharide fractions, SGP-1 and SGP-2, were isolated from the rhizomes of S. glabra with the number average molecular weights of 1.72 × 10(2)kDa and 1.31 × 10(2)kDa, and the weight average molecular weights of 1.31 × 10(5)kDa and 1.18 × 10(5)kDa, respectively, and their mainly monosaccharide compositions were both galactose and rhamnose (2.5:1). Both SGP-1 and SGP-2 significantly suppressed the release of nitric oxide (NO), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) from LPS-induced RAW 264.7 cells, as well as the mRNA expression of inducible nitric oxide synthase (iNOS), TNF-α and IL-6. Additionally, SGP-1 and SGP-2 repressed the extracellular signal-regulated kinase (ERK) and c-Jun NH2-terminal kinase (JNK). These findings strongly suggested polysaccharides were also the anti-inflammatory active ingredient for S. glabra, and the potential of SGP-1 and SGP-2 as the anti-inflammatory agents.


Subject(s)
Anti-Inflammatory Agents/pharmacology , Inflammation Mediators/metabolism , Inflammation/drug therapy , JNK Mitogen-Activated Protein Kinases/metabolism , Lipopolysaccharides/pharmacology , Macrophages/metabolism , Mitogen-Activated Protein Kinases/metabolism , Smilax/chemistry , Animals , Apoptosis/drug effects , Blotting, Western , Cell Proliferation/drug effects , Cells, Cultured , Inflammation/metabolism , JNK Mitogen-Activated Protein Kinases/genetics , MAP Kinase Signaling System , Macrophages/drug effects , Macrophages/immunology , Mice , Mitogen-Activated Protein Kinases/genetics , NF-kappa B/metabolism , Nitric Oxide/metabolism , Nitric Oxide Synthase Type II/metabolism , Phosphorylation/drug effects , RNA, Messenger/genetics , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction , Rhizome/chemistry
15.
Article in English | MEDLINE | ID: mdl-25821492

ABSTRACT

The rhizome of Smilax glabra has been used for a long time as both food and folk medicine in many countries. The present study focused on the active constituents from the rhizome of S. glabra, which possess potential anti-inflammatory activities. As a result, nine known compounds were isolated from the rhizome of S. glabra with the bioassay-guiding, and were identified as syringaresinol (1), lasiodiplodin (2), de-O-methyllasiodiplodin (3), syringic acid (4), 1,4-bis(4-hydroxy-3,5-dimethoxyphenyl)-2,3-bis(hydroxymethyl)-1,4-butanediol (5), lyoniresinol (6), trans-resveratrol (7), trans-caffeic acid methyl ester (8), and dihydrokaempferol (9). Among these compounds, 2 and 3 were isolated for the first time from S. glabra. In addition, the potential anti-inflammatory activities of the isolated compounds were evaluated in vitro in lipopolysaccharide- (LPS-) induced RAW264.7 cells. Results indicated that 4 and 7 showed significant inhibitory effects on NO production of RAW264.7 cells, and 1, 2, 3, and 5 showed moderate suppression effects on induced NO production. 1, 7, and 5 exhibited high inhibitory effects on TNF-α production, with the IC50 values less than 2.3, 4.4, and 16.6 µM, respectively. These findings strongly suggest that compounds 1, 2, 3, 4, 5, 7, and 9 were the potential anti-inflammatory active compositions of S. glabra.

16.
J Orthop Trauma ; 28(1): 17-22, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24121985

ABSTRACT

OBJECTIVES: The aims of this study were to evaluate the morphologic discrepancies between the short straight proximal femoral nail antirotation-Asian version (PFNA-II) and the anterior bow of the femur in Chinese patients and to propose a further design modification. DESIGN: Retrospective study. SETTING: Level I academic trauma center. PATIENTS/PARTICIPANTS: A consecutive 158 cases (35 men and 123 women with mean age of 77.2 years) with unstable per/intertrochanteric fractures (AO/OTA 31 A2 and A3) treated by PFNA-II from August 2008 to December 2010 participated in this study. INTERVENTION: Nailing of PFNA-II. MAIN OUTCOME MEASUREMENTS: The nail tip position was classified to a 5-grade scale on postoperative lateral radiographs of the femur. The distance between the nail axis and the canal axis at the tip level was measured. The degree of the theoretical bent curvature and its corresponding radius were calculated, assuming that the anterior protrusive nail tip was placed back to the central canal axis. RESULTS: The distal tip of PFNA-II was located anterior to the femur canal central axis in 118 cases (74.7%), of which 55 cases abutted against the anterior cortex (contact between nail and internal cortex) (34.8%). With longer nails, the abutment occurred more often and was more prominent. For nail lengths of 170, 200, and 240 mm, the theoretical distance to replace the nail tip to the central canal axis was 1.42 ± 0.18, 1.77 ± 0.39, and 2.46 ± 0.20 mm, respectively; the corresponding bent curvature angle was 2.51 ± 2.40, 2.13 ± 1.65, and 2.09 ± 0.98 degrees, respectively; and the bent curvature radius was 1483 ± 818, 2329 ± 1293, and 3710 ± 1957 mm, respectively. CONCLUSIONS: There is a mismatch between the current short straight PFNA-II and the anterior bow of the femur in the Chinese population. In light of the documented complications and technical problems related to this mismatch, further modifications with an anterior bow are proposed.


Subject(s)
Bone Nails , Fracture Fixation, Intramedullary/instrumentation , Hip Fractures/surgery , Aged , Aged, 80 and over , Asian People , Female , Humans , Male , Retrospective Studies , Treatment Outcome
17.
J Econ Entomol ; 101(6): 1760-70, 2008 Dec.
Article in English | MEDLINE | ID: mdl-19133454

ABSTRACT

Storage of Conatocerus ashmeadi Girault (Hymenoptera: Mymaridae) adults at 2, 5, and 10 degrees C showed that these parasitoids do not survive at 2 degrees C for 5 d, and exposure to 5 and 10 degrees C shortens their life span. The lethal time (LT) 50 (i.e., length of storage time for 50% wasp survival) at 5 degrees C was 14 d for males and approximately 29 d for females, whereas at 10 degrees C was 32 and 39 d, respectively. Effects of adult storage at 10 degrees C on other factors indicating fitness, such as fecundity, developmental time, parasitism, emergence, and sex ratio, were examined on female wasps and their progeny at 10-d intervals for up to 60 d. Glassy-winged sharpshooter, Homalodisca vitripennis (Germar), eggs were used as hosts for propagation of this wasp and for assessing its oviposition and fecundity. Increasing adult storage time decreased the length of the ovipositional period for the maternal generation, and oviposition was decreased by 90% after 60-d storage. A significant reduction in maternal lifetime fecundity occurred after 20-d storage and in the incidence of parasitism after 40 d. We also found a carryover effect caused by storage of the maternal generation that was expressed in the F1 generation. When cold storage of the adult parents was > or = 20 d, we observed delayed development, decreased fecundity, reduced longevity, and increased male production occurring in the F1 generation. Reduced fitness of the F1 generation was also expressed as a decrease in net reproductive rate (R(o)) and an increase in mean generation time (T(c)). However, none of these deleterious effects were evident in the F2 progeny that descended from grandparents that had experienced cold storage. Damage caused by indirect chilling injury and/or induced maternal aging occurring during storage can account for the decreased fitness of maternal and F1 generations. Providing that the limits of cold tolerance of G. ashmeadi as defined in this study are not exceeded, our results show that short-term cold storage of adults could be used in a mass-rearing program.


Subject(s)
Cold Temperature , Wasps/physiology , Animals , Female , Fertility , Longevity , Male , Oviposition , Sex Ratio , Wasps/growth & development
18.
J Econ Entomol ; 100(3): 685-94, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17598526

ABSTRACT

This study assessed the effects of refrigerated storage on the suitability of eggs of the glassy-winged sharpshooter, Homalodisca coagulata (Say) (Hemiptera: Cicadellidae), as hosts for propagation of the parasitoid Gonatocerus ashmeadi Girault (Hymenoptera: Mymaridae). Development of the host eggs was terminated by chilling at 2 degrees C for 5 d before storage was initiated at 10 degresC for up to 70 d. Parasitism, adult emergence rate, developmental time, and sex ratio were used to gauge the suitability of the eggs as hosts after storage. In addition to these measures, demographic growth parameters also were used to assess the quality of the wasp progeny through the F2 generation. Host eggs stored 20 d remained fully acceptable to the wasps for attack. Although the parasitism rate decreased with storage time, > 80% adult parasitoid emergence was realized from eggs stored 30 d. After 70 d storage, adult emergence rate was decreased by 48%, fecundity decreased by 53%, female production by 19%, developmental time was extended 3 d, and female longevity was shortened 5 d. The emergence pattern of F1 but not F2 adults varied with storage time of the parental and grandparental hosts, respectively. For the F1 generation, emergence rate, development, and sex ratio did not vary with storage time when the F1 parents parasitized fresh host eggs. Demographic parameters for the F, population showed that net reproductive rate was > 20 although it decreased significantly after their parental host eggs were stored for > 30 d. The intrinsic and finite rates of increase, population doubling time, and mean generation time decreased only after storage for 60 d. Our results show that short-term cold storage could be used for maintaining wasp populations in a mass-rearing program and that the detrimental effects of chilling host eggs in storage for over 30 d do not extend to F2 generation.


Subject(s)
Breeding/methods , Hemiptera/parasitology , Ovum/parasitology , Wasps/physiology , Animals , Cold Temperature , Female , Fertility , Hemiptera/embryology , Host-Parasite Interactions , Longevity , Male , Ovum/cytology , Sex Ratio , Wasps/growth & development
19.
Org Lett ; 8(20): 4397-400, 2006 Sep 28.
Article in English | MEDLINE | ID: mdl-16986909

ABSTRACT

The design, synthesis, and evaluation of a series of catechol-based non-peptide peptidomimetics of the peptide hormone somatostatin have been achieved. These ligands comprise the simplest known non-peptide mimetics of the i + 1 and i + 2 positions of the somatostatin beta-turn. Incorporation of an additional side chain to include the i position of the beta-turn induces a selective 9-fold affinity enhancement at the sst2 receptor.


Subject(s)
Catechols/chemistry , Molecular Mimicry , Somatostatin/chemistry , Models, Molecular
20.
Org Lett ; 8(9): 1799-802, 2006 Apr 27.
Article in English | MEDLINE | ID: mdl-16623554

ABSTRACT

[structure: see text] Cyclic hexapeptides, incorporating a dipeptide unit in place of the disulfide bond found in urotensin, were prepared and screened at the human urotensin receptor. The bridging dipeptide unit was found to influence dramatically the affinity for the urotensin receptor. Alanyl-N-methylalanyl and alanylprolyl dipeptide bridges failed to afford active ligands, while the alanyl-alanyl unit yielded a ligand with submicromolar affinity for the urotensin receptor. Further development led to a hexapeptide agonist with nanomolar affinity (2.8 nM).


Subject(s)
Dipeptides/chemistry , Peptides, Cyclic/chemistry , Peptides, Cyclic/chemical synthesis , Receptors, G-Protein-Coupled/agonists , Receptors, G-Protein-Coupled/chemistry , Urotensins/agonists , Amino Acid Sequence , Binding Sites , Cystine/chemistry , Humans , Models, Molecular , Molecular Structure , Urotensins/chemistry
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