Biocontrol potential of the entomopathogenic nematodes Heterorhabditis bacteriophora and Steinernema carpocapsae on cucurbit fly,Dacus ciliatus (Diptera: Tephritidae)

Entomopathogenic nematodes (EPNs) from the families Steinernematidae and Hererorhabditidae are considered excellent biological control agents against many insects that damage the roots of crops. In a regional survey, native EPNs were isolated, and laboratory and greenhouse experiments were conducted to determine the infectivity of EPNs against the cucurbit fly, Dacus ciliatus Loew (Diptera: Tephritidae). Preliminary experiments showed high virulence by a native strain of Heterorhabditis bacteriophora Poinar (Rhabditida: Heterorhabditidae) and a commercial strain of Steinernema carpocapsae Weiser (Rhabditida: Steinernematidae). These two strains were employed for further analysis while another native species, Steinernema feltiae, was excluded due to low virulence. In laboratory experiments, larvae and adult flies were susceptible to nematode infection, but both nematode species induced low mortality on pupae. S. carpocapsae had a significantly lower LC₅₀ value against larvae than H. bacteriophora in filter paper assays. Both species of EPNs were effective against adult flies but S. carpocapsae caused higher adult mortality. When EPN species were applied to naturally infested fruit (150 and 300 IJs/cm²), the mortality rates of D. ciliatus larvae were 28% for S. carpocapsae and 12% for H. bacteriophora. Both EPN strains successfully reproduced and emerged from larvae of D. ciliates. In a greenhouse experiment, H. bacteriophora and S. carpocapsae had similar effects on fly larvae. Higher rates of larval mortality were observed in sandy loam and sand soils than in clay loam. The efficacy of S. carpocapsae and H. bacteriophora was higher at 25 and 30°C than at 19°C. The results indicated that S. carpocapsae had the best potential as a biocontrol agent of D. ciliatus, based on its higher virulence and better ability to locate the fly larvae within infected fruits.     

Temperature-dependent development and life table parameters of <Emphasis Type="Italic">Typhlodromus bagdasarjani</Emphasis> (Phytoseiidae) fed on two-spotted spider mite

The predatory mite Typhlodromus bagdasarjani Wainstein and Arutunjan (Acari: Phytoseiidae) is an indigenous and widespread species of the Middle East fauna. In this paper we assess the effect of temperature on developmental rate and reproduction potential of T. bagdasarjani under laboratory conditions. The development of this species was determined at 15, 20, 25, 30, 35 and 37.5 ± 1°C, 60 ± 10% RH and L16:D8 h photoperiod. The total developmental time averaged 28.2, 15.0, 8.9, 7.6, 7.2 and 7.4 days at 15–37.5°C, respectively, when feeding on immature stages of two-spotted spider mite, Tetranychus urticae Koch. The lower developmental threshold (T ₀ ) and thermal constant (K) for the development of this predator were estimated 9.2°C and 162 degree-days by the Ikemoto linear model. The life table parameters were estimated at 15–35°C. The shortest life span of females at 35°C was 45.0 days, followed by 50.7, 50.9, 103.3 and 136.8 days at 30, 25, 20 and 15°C, respectively. Mated females laid on average 19.9, 26.3, 41.1, 39.6 and 31.3 eggs per female at 15–35°C, respectively. The intrinsic rate of increase (r _m ) and finite rate of increase (λ) increased significantly with increasing temperature. The r _m values ranged from 0.021 (15°C) to 0.186 (35°C) days⁻¹. The highest value of net reproductive rate (R ₀) was 13.6 females progeny/female/generation at 25°C. The results demonstrated that T. bagdasarjani is well adapted to high temperatures. However, the efficiency to control spider mites may be affected by behavioral characteristics of the predator and its prey under real conditions.     

An integrated chromosome map of microsatellite markers and inversion breakpoints for an Asian malaria mosquito, Anopheles stephensi

Anopheles stephensi is one of the major vectors of malaria in the Middle East and Indo-Pakistan subcontinent. Understanding the population genetic structure of malaria mosquitoes is important for developing adequate and successful vector control strategies. Commonly used markers for inferring anopheline taxonomic and population status include microsatellites and chromosomal inversions. Knowledge about chromosomal locations of microsatellite markers with respect to polymorphic inversions could be useful for better understanding a genetic structure of natural populations. However, fragments with microsatellites used in population genetic studies are usually too short for successful labeling and hybridization with chromosomes. We designed new primers for amplification of microsatellite loci identified in the A. stephensi genome sequenced with next-generation technologies. Twelve microsatellites were mapped to polytene chromosomes from ovarian nurse cells of A. stephensi using fluorescent in situ hybridization. All microsatellites hybridized to unique locations on autosomes, and 7 of them localized to the largest arm 2R. Ten microsatellites were mapped inside the previously described polymorphic chromosomal inversions, including 4 loci located inside the widespread inversion 2Rb. We analyzed microsatellite-based population genetic data available for A. stephensi in light of our mapping results. This study demonstrates that the chromosomal position of microsatellites may affect estimates of population genetic parameters and highlights the importance of developing physical maps for nonmodel organisms.     

GHSR DNA hypermethylation is a new epigenetic biomarker for gastric adenocarcinoma and beyond

Aberrations of DNA methylation are early events in the development of tumors. In this study, we investigated the DNA methylation status of growth hormone secretagogue receptor (GHSR), a promising pan-cancer biomarker, in gastric cancer (GC). Initially, data sets from DNA methylation and gene expression studies available at Gene Expression Omnibus (GEO) were analyzed. Confirmation was done on primary tumor specimens and adjacent normal stomach tissue samples. Both analyses showed significant hypermethylation of GHSR. For further validation, The Cancer Genome Atlas data on stomach cancer was used. A receiver operating characteristic curve analysis yielded an area under the curve value of 0.85, corroborating its usefulness as a diagnostic marker. A genome-wide comethylation analysis revealed several correlated genes. CREB1 was found to act as an upstream regulator of this gene network. Furthermore, GHSR methylation was found to be a biomarker in several other tumor entities, namely cancers of the bladder, endometrium, esophagus, head and neck, liver, thyroid, kidney, and ovary. Our findings along with previous reports on other types of cancer suggest a high potential of GHSR gene methylation as a pan-cancer biomarker, which could be considered for liquid biopsy applications.     

An efficient protocol for micropropagation of old cypress of Abarkuh (Cupressus sempervirens var. horizontalis [Mill.]) under in vitro condition

Plant Cell, Tissue and Organ Culture (PCTOC) - This study was carried out to investigate the DNA markers between diploid and colchicine-induced autotetraploid Platycodon grandiflorum A. De Candolle...     

Yellow nail syndrome: treatment of lymphedema using low pressure compression

The present report describes a case with the triad of yellow nail syndrome (YNS) and the use of low-pressure compression pump as treatment of lymphedema in YNS. A 71-year-old woman presented with bilateral lower extremity lymphedema, yellow nails, and recurrent bilateral pleural effusion. In this case, we specifically focused on lymphedema treatment of the legs besides other recommendations for YNS.     

Baseline morbidity in 2,990 adult African volunteers recruited to characterize laboratory reference intervals for future HIV vaccine clinical trials

Background

An understanding of the health of potential volunteers in Africa is essential for the safe and efficient conduct of clinical trials, particularly for trials of preventive technologies such as vaccines that enroll healthy individuals. Clinical safety laboratory values used for screening, enrolment and follow-up of African clinical trial volunteers have largely been based on values derived from industrialized countries in Europe and North America. This report describes baseline morbidity during recruitment for a multi-center, African laboratory reference intervals study.

Methods

Asymptomatic persons, aged 18–60 years, were invited to participate in a cross-sectional study at seven sites (Kigali, Rwanda; Masaka and Entebbe, Uganda; Kangemi, Kenyatta National Hospital and Kilifi, Kenya; and Lusaka, Zambia). Gender equivalency was by design. Individuals who were acutely ill, pregnant, menstruating, or had significant clinical findings were not enrolled. Each volunteer provided blood for hematology, immunology, and biochemistry parameters and urine for urinalysis. Enrolled volunteers were excluded if found to be positive for HIV, syphilis or Hepatitis B and C. Laboratory assays were conducted under Good Clinical Laboratory Practices (GCLP).

Results and Conclusions

Of the 2990 volunteers who were screened, 2387 (80%) were enrolled, and 2107 (71%) were included in the analysis (52% men, 48% women). Major reasons for screening out volunteers included abnormal findings on physical examination (228/603, 38%), significant medical history (76, 13%) and inability to complete the informed consent process (73, 13%). Once enrolled, principle reasons for exclusion from analysis included detection of Hepatitis B surface antigen (106/280, 38%) and antibodies against Hepatitis C (95, 34%). This is the first large scale, multi-site study conducted to the standards of GCLP to describe African laboratory reference intervals applicable to potential volunteers in clinical trials. Approximately one-third of all potential volunteers screened were not eligible for analysis; the majority were excluded for medical reasons.     

Evaluating the Potential of an Antibody Against Recombinant OmpW Antigen in Detection of Vibrio cholerae by Surface Plasmon Resonance (SPR) Biosensor

Surface plasmon resonance (SPR), a highly sensitive and label-free optical biosensing technique, is a powerful tool for studying biomolecular interactions. An immunosensor for rapid, sensitive, and selective detection of Vibrio cholerae on the basis of SPR is reported. Recombinant OmpW antigen (a bacterial outer-membrane protein) of V. cholerae was expressed and purified and raising of polyclonal rabbit anti-OmpW was done. Antibodies were immobilized on a sensor surface and interactions between OmpW protein and the whole cell of V. cholerae with immobilized antibodies were studied in different experiments. The aim of this study was to evaluate the potential of anti-OmpW in detection of V. cholerae by developing an immunosensor based on SPR. The results showed high affinity interaction between OmpW and anti-OmpW (K _D = 2.4 ± 0.07 × 10⁻⁹ M) and SPR signals had a linear relationship with the number of V. cholerae ranging from 1 × 10² to 1 × 10⁷ cells/mL with limit of detection of 50 cells/mL. The specificity of the developed immunoassay was examined using some non-V. cholerae bacteria which did not produce any significant responses. This method is rapid, sensitive, and specific to target V. cholerae with a total analysis time of less than 60 min.

     

The development of inducer and effector immune suppressor cell function in Xenopus laevis, the South African clawed toad: the effect of metamorphosis

Thymic capacity to induce suppression of antibody production by immunized Xenopus laevis toadlet spleen fragments was tested in co-cultures for different developmental stages (Nieuwkoop, P.D. and J. Faber: Normal Table of Xenopus laevis (Daudin) (North Holland, Amsterdam) 1967). While thymuses of stages 52-54 (premetamorphosis) induced suppression, those of stages 58-62 (metamorphosis) did not. This capacity returned in metamorphic climax (stages 63-65). Tests of lectin-induced suppressor function in spleens of different developmental stages exposed the same pattern of compromised activity during metamorphosis. To test whether larval thymuses could effect suppression, rather than just induce it, antigen-activated thymuses from the different stages were co-cultured with immunized toadlet spleen fragments which had been suppressor-depleted by cyclophosphamide. Only thymuses from premetamorphic larvae suppressed. Thus, when thymic capacity to induce suppression returned in metamorphic climax, it was adult-like: it lacked effector suppressor cells.     

Effects of acclimation and diapause on the thermal tolerance of the two-spotted spider mite Tetranychus urticae

The two-spotted spider mite, Tetranychus urticae, is a worldwide pest species that overwinters as diapausing females. Cold hardening is presumed to start during diapause development to ensure the successful overwintering of this species. To address this hypothesis, we compared cold tolerance between non-diapausing and diapausing females. We measured supercooling point (SCP) and survival to acute cold stress by exposing the mites at a range of sub-zero temperatures (from −4 to −28 °C for 2 h). The mean SCPs of non-diapausing and diapausing females were −19.6±0.5 and −24.7±0.3 °C respectively, and freezing killed the mites. Diapausing females were significantly more cold tolerant than non-diapausing ones, with LT₅₀ of −19.7 and −13.3 °C, respectively. Further, we also examined the effects of cold acclimation (10 d at 0 or 5 °C) in non-diapausing and diapausing females. Our findings indicated that diapause decreased SCP significantly, while cold acclimation had no effect on the SCP except for non-diapausing females that were acclimated at 5 °C. Acclimation at 5 °C enhanced survival to acute cold stress in diapausing and non-diapausing females, with LT₅₀ of −22.0 and −17.1 °C, respectively. Altogether, our results indicate that T. urticae is a chill tolerant species, and that diapause and cold acclimation elevate cold hardiness in this species.