204 research outputs found
Insecticide Toxicity, Synergism and Resistance in Plutella xylostella (Lepidoptera: Plutellidae)
Plutella xylostella has become particularly notorious for its
resistance to various insecticides. The toxicities of abamectin, hexaflumuron
and indoxacarb to third instar larvae of the pest were assayed using the
leaf-dipping method. The results showed that abamectin and indoxacarb with the
lowest LC50 values exhibited stronger toxicity to larvae than hexaflumuron. To
determine the synergism of PBO, DEM, DEF and TPP on the toxicity of tested
insecticides and demonstrating possible biochemical mechanisms, an abamectin-, a
hexaflu-muron- and an indoxacarb-resistant strain of P.
xylostella were selected under laboratory conditions. After 10
generations of selection, the selected strains developed 14.21, 7.08, and
32.36-fold higher resistance to these insecticides, respectively. Abamectin
resistance in abamectin-selected strain was suppressed with the synergists such
as DEM and PBO, suggesting the involvement of monooxygeneses and glutathione
S-transferase in the development of resistance in P.
xylostella. Treatment with PBO and DEF significantly decreased the
toxicity of hexaflumuron in the hexaflumuron-selected strain. Also, in
indoxacarb-selected strain, the maximum synergism was occurred using PBO and
DEF, followed by DEM and TPP. Hexaflumuron and indoxacarb synergism studies
indicated in hexaflumuron resistance, monooxygenases and esterases, and in
indoxacarb resistance, monooxygenases, esterases and glutathione S-transferae
may be involved in the resistance mechanism
The association of a genetic variant in CDKN2A/B gene and the risk of colorectal cancer
Colorectal cancer is among the most aggressive tumors, and its development involves an interplay between various genetic and environmental familial risk factors. Several genetic polymorphisms have been reported to be associated with colorectal cancer in recent studies. In this current study, we aimed to evaluate the possible relationship between a CDKN2A/B, single nucleotide polymorphisms (SNP) (rs10811661), with the risk of colorectal cancer. A total of 541 individuals with, or without cancer were recruited. DNA was extracted, and genotyped using a Taq-Man based real‐time PCR method. The rs10811661 SNP was associated with an increased risk of colorectal cancer (additive model: OR=3.46, CI= 1.79-6.69, p<0.0001 and recessive model: 5.72, CI= 3.12-10.49, p<0.0001). The distribution of minor alleles in the total population for homozygote allele was 9.2 %, while this was 20.1 % for heterozygotes. In summary, our findings indicate that the rs10811661 polymorphism of the CDKN2A/B gene was strongly related to the occurrence of colorectal cancer suggesting its potential role as a prognostic biomarker for the management of colorectal cancer
Temperature-dependent development of Habrobracon hebetor (Hym.: Braconidae) reared on larvae of Galleria mellonella (Lep.: Pyralidae)
The development times and the survival rates of different stages of Habrobracon hebetor Say reared on the last instar larvae of Galleria mellonella (L.) were compared at ten different constant temperatures (16 - 38 ºC). The development time of immature stages of the parasitoid, H. hebetor, decreased as the temperature increased in the range of 16 to 38 ºC. However, no larvae could survive and develop at 16 ºC. Development time from egg to adult females was the shortest (8.368 ± 0.069 days) at 35 ºC and the longest (32.667 ± 0.33 days) at 18 ºC. Egg incubation period, larval and pupal development times were significantly different at various constant temperatures. No significant difference was found between two sexes in their developmental periods from eggs to adult stage. The survival rate of the egg stage ranged between 94.90 and 100% at all temperature levels, but larval survival rates was significantly different at various temperatures. Although significant difference was found in the survival rate of pupal stage (P < 0.05), the trend of survival rate for pupae was similar to those of larvae. The relationship between temperature and the developmental rate of the parasitoid well described by linear regression model (R2 = 0.89, P = 0.0001, at the egg stage and R2 = 0.95, P = 0.0001, at the egg-adult stage). The lowest threshold temperature was obtained for all developmental stages of the parasitoid. Degree-days requirements (DD) for egg, larva, pupa and egg-female stages were 22.73, 56.82, 109.89 and 188.68, respectively. The results in this study showed that the temperature range between 25 and 32 ºC provide a favourable condition for mass rearing of this parasitoid
Cuminum cyminum methanolic extract – Fe<sub>3</sub>O<sub>4</sub> nanocomposite: A novel and efficient insecticide against the potato tuber moth (Lepidoptera: Gelechiidae) to protect potatoes
Phthorimaea operculella is a significant insect pest of cultivated potatoes in tropical and subtropical regions such as Iran. Since the potato is one of the most valuable sources of human food, non-chemical control of potato pests is essential. Application of medicinal plant extracts is a low-risk alternative method to synthetic chemical insecticides. Hence, the present study was conducted to investigate a potential strategy to improve the insecticidal activity of plant extracts for efficient management of P. operculella. The insecticidal efficacy of pure methanolic extract (PME) and Fe3O4@methanolic extract (FME) of Cuminum cyminum were evaluated against the potato tuber moth under laboratory conditions. The morphological characteristics of Fe3O4@Cumin were investigated by scanning electron microscope. Magnetic properties of the samples were determined using a vibration sample magnetometer. XRD was used to prove the crystalline structure of Fe3O4@Cumin. SEM, FTIR, XRD, and VSM analyses confirmed that the methanolic extract was loaded on Fe3O4. The toxicity of PME and Fe3O4@Cumin were evaluated on one-day-old eggs and penetration the first instar larvae of P. operculella into potato tubers and leaves. The LC50 values of Cumin extract and Fe3O4@ Cumin were 961.07 and 601.48 and 496.84 and 268.82 ppm for penetrating neonate larvae to tubers and leaves, and 874.90 and 595.16 ppm for eggs, respectively. Bioassays revealed that Fe3O4@Cumin was more toxic than non-formulated Cumin methanolic extract against eggs and neonate larvae of P. operculella. The formulated methanolic extract was significantly more repellent against the pest. Our results suggested that the prepared nanocomposite could be used as a new effective tool for P. operculella management strategies to protect potatoes
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The potential prognostic and therapeutic application of tissue and circulating microRNAs in cervical cancer
Cervical cancer (CC) is a common malignancy in women and a major cause of cancer- related mortality globally. Some novel biomarkers may enable the early diagnosis and monitoring of CC. MicroRNAs are small noncoding RNAs that control gene translation at a post transcriptional level. Hence the deregulation of these molecules can cause many diseases. There appears to be an association between aberrant miRNA expression and CC, but the molecular mechanisms involved in the development of CC remain unknown. The upregulation of some circulating miRNAs, e.g. miRNA-20a, miRNA-203, miRNA-21, miRNA-205, miRNA-218, and miR-485-5, as well as tissue specific-miRNAs, e.g. miR-7, miR-10a, miR-17-5p, miR-135b, miR-149 and miR-203 has been found in patients with CC. There is also growing evidence for the importance of miRNAs in the development of drug-resistance. This review therefore highlights recently published preclinical and clinical investigation performed on tissue-specific and circulating miRNAs, as potential biomarkers for the detection of patients at early stages of CC, in the prediction of prognosis, and monitoring of their response to therapy.
Key word: cervical cancer, CIN, MiRNA, circulating biomarker, tissue-specific biomarker, HP
Crocin synergistically enhances the anti-proliferative activity of 5-FU through Wnt/PI3K pathway in a mouse model of colitis-associated colorectal cancer
Colorectal-cancer (CRC) is the third most common cause of cancer-related-death, and hence there is a need for the identification of novel-agents to improve the efficacy of existing-therapies. There is growing evidence for the anti-tumor-activity of crocin, although its activity and molecular-mechanisms in CRC remains to be elucidated. Here we explored the therapeutic-application of crocin or its combination with 5-Flurouracil in a mouse-model of colitis-associated colon-cancer. The anti-proliferative-activity of crocin was assessed in 2- and 3-dimensional cell-culture-models. The migratory-behaviors were determined, while the expression-levels of several-genes were assessed by qRT-PCR/Western-blotting. We examined the anti-inflammatory properties of crocin by pathological-evaluation and disease-activity-index as well as oxidative/ antioxidant markers: malondialdehyde (MDA) and total-thiols (T-SH) levels and superoxide-dismutase (SOD) and catalase (CAT) activity. Crocin suppressed cell-growth and the invasive-behavior of CRC-cells through modulation of the Wnt-pathway and E-cadherin. Moreover, administration of crocin alone, or in combination with 5-FU dramatically reduced the tumor-number and tumor-size in both distal/mid-colon followed by reduction in disease-activity-index. Crocin also suppressed the colonic-inflammation induced by Dextran-sulfate-sodium and notably recovered the increased-levels of MDA, decreased Thiol-levels and activity of CAT-levels. Crocin was able to ameliorate the severe-inflammation with mucosal-ulcers and high grade-dysplastic-crypts as detected by inflammation-score, Crypt-loss, pathological-changes and histology-scores. We demonstrated an antitumor-activity of crocin in CRC and its potential role in improvement of inflammation with mucosal ulcers and high grade dysplastic crypts, supporting the desireability of further investigations on the therapeutic potential of this approach in CRC
Detecting Distributed Denial of Service Attacks in Neighbour Discovery Protocol Using Machine Learning Algorithm Based on Streams Representation
© 2018, Springer International Publishing AG, part of Springer Nature. The main protocol of the Internet protocol version 6 suites is the neighbour discovery protocol, which is geared towards substitution of address resolution protocol, router discovery, and function redirection in Internet protocol version 4. Internet protocol version 6 nodes employ neighbour discovery protocol to detect linked hosts and routers in Internet protocol version 6 network without the dependence on dynamic host configuration protocol server, which has earned the neighbour discovery protocol the title of the stateless protocol. The authentication process of the neighbour discovery protocol exhibits weaknesses that make this protocol vulnerable to attacks. Denial of service attacks can be triggered by a malicious host through the introduction of spoofed addresses in neighbour discovery protocol messages. Internet version 6 protocols are not well supported by Network Intrusion Detection System as is the case with Internet Protocol version 4 protocols. Several data mining techniques have been introduced to improve the classification mechanism of Intrusion detection system. In addition, extensive researches indicated that there is no Intrusion Detection system for Internet Protocol version 6 using advanced machine-learning techniques toward distributed denial of service attacks. This paper aims to detect Distributed Denial of Service attacks of the Neighbour Discovery protocol using machine-learning techniques, due to the severity of the attacks and the importance of Neighbour Discovery protocol in Internet Protocol version 6. Decision tree algorithm and Random Forest Algorithm showed high accuracy results in comparison to the other benchmarked algorithms
A Large Animal Model of Right Ventricular Failure due to Chronic Thromboembolic Pulmonary Hypertension: A Focus on Function
Chronic thromboembolic pulmonary hypertension (CTEPH) is a debilitating disease that progresses to right ventricular (RV) failure and death if left untreated. Little is known regarding the progression of RV failure in this disease, greatly limiting effective prognoses, and therapeutic interventions. Large animal models enable the use of clinical techniques and technologies to assess progression and diagnose failure, but the existing large animal models of CTEPH have not been shown to replicate the functional consequences of the RV, i.e., RV failure. Here, we created a canine embolization model of CTEPH utilizing only microsphere injections, and we used a combination of right heart catheterization (RHC), echocardiography (echo), and magnetic resonance imaging (MRI) to quantify RV function. Over the course of several months, CTEPH led to a 6-fold increase in pulmonary vascular resistance (PVR) in four adult, male beagles. As evidenced by decreased cardiac index (0.12 ± 0.01 v. 0.07 ± 0.01 [L/(min*kg)]; p < 0.05), ejection fraction (0.48 ± 0.02 v. 0.31 ± 0.02; p < 0.05), and ventricular-vascular coupling ratio (0.95 ± 0.09 v. 0.45 ± 0.05; p < 0.05), as well as decreased tricuspid annular plane systolic excursion (TAPSE) (1.37 ± 0.06 v. 0.86 ± 0.05 [cm]; p < 0.05) and increased end-diastolic volume index (2.73 ± 0.06 v. 2.98 ± 0.02 [mL/kg]; p < 0.05), the model caused RV failure. The ability of this large animal CTEPH model to replicate the hemodynamic consequences of the human disease suggests that it could be utilized for future studies to gain insight into the pathophysiology of CTEPH development, following further optimization
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