Recent evolution of a novel begomovirus causing tomato leaf curl disease in the Al-Batinah region of Oman

For last two decades, begomoviruses (family Geminiviridae) have been a major constraint for tomato production in Oman, particularly in the Al-Batinah region, the major agricultural area of Oman. Farms in the Al-Batinah region were surveyed during January-March and November-December in 2012 and January-February in 2013. Leaf samples of tomato plants showing typical leaf curl disease symptoms were collected and analyzed for begomoviruses. Out of fifteen begomovirus clones sequenced, seven were shown to be tomato yellow leaf curl virus strain Oman (TYLCV-OM); three, chili leaf curl virus strain Oman (ChLCV-OM); and one, tomato leaf curl Oman virus (ToLCOMV) – viruses that have previously been shown to occur in Oman. Four sequences were shown to have relatively low percent identity values to known begomoviruses, with the highest (86 %) to isolates of pepper leaf curl Lahore virus, indicating that these should be included in a new species, for which the name “Tomato leaf curl Al Batinah virus” (ToLCABV) is proposed. Although the betasatellite tomato leaf curl betasatellite (ToLCB; 7 full-length sequences isolated) was identified with some isolates of ChLCV-OM, TYLCV-OM and ToLCOMV, it was not identified in association with any of the ToLCABV isolates. Analysis of the sequences of the TYLCV-OM and ToLCOMV isolates characterized here did not show them to differ significantly from previously characterized isolates of these viruses. The three isolates of ChLCV-OM characterized were shown to have a recombination pattern distinct from earlier characterized isolates. ToLCABV was shown to have resulted from recombination between ChLCV-OM and ToLCOMV. A clone of ToLCABV was infectious by Agrobacterium-mediated inoculation to Nicotiana benthamiana and tomato, inducing symptoms typical of those seen in tomato in the field. Additionally, ToLCABV was shown to be able to interact in planta with ToLCB, resulting in a change in symptom phenotype, although the betasatellite did not appear to affect viral DNA levels.     

Novel germline CDK4 mutations in patients with head and neck cancer

ABSTRACT: BACKGROUND: Cyclin-dependent kinase 4 (CDK4) together with its regulatory subunit cyclin D1, governs cell cycle progression through G1 phase. Cyclin-dependent kinase inhibitors, including p16INK4A in turn regulate CDK4. In particular, deregulation of the p16/CDK4/cyclin D1 complex has been established in a variety of human tumors including gliomas, sarcomas, melanoma, breast and colorectal cancer. However, changes in CDK4 have rarely been observed. METHOD: In this study we used a combination of PCR-SSCP and direct sequencing for mutational screening of CDK4. DNA was isolated from peripheral blood leukocyte of patients with squamous cell carcinoma of head and neck, for screening germline mutations in coding regions of CDK4. RESULTS: Variations observed in exon 2 and 5 were three missense mutations, g5051G > C (Ser52Thr), g5095G > C (Glu67Gln), g5906C > A, g5907C > G (Pro194Ser) and novel frame shift mutations g7321_23delTGA, g7121_7122insG, g7143delG in exon 7 and 3[PRIME]UTR respectively. CONCLUSION: In conclusion, two novel mutations were found in N terminal domain which indicates that CDK4 mutation may play a major role in the development and progression of squamous cell carcinoma of head and neck.     

Overlooking the Obvious: Communication of Efficacy by the Mass Media During the Ebola Crisis in Liberia

Prevention Science - The role of mass media during a public health crisis is an ineluctable part of providing the public with critical information rapidly, particularly messages about self- and...     

OGG1 gene sequence variation in head and neck cancer patients in Pakistan

In Pakistani culture tobacco use is very high and a well known risk factor for developing head and neck cancer (HNC), tobacco smoke containing high quantities of chemical carcinogens such as aromatic amines and reactive oxygen species. OGG1 is the primary enzyme in the base excision repair (BER) pathway, responsible for the excision of 7, 8-dihydro-8-oxoguanine, a mutagenic base byproduct that occurs as a result of exposure to reactive oxygen species. Groups of 300 already diagnosed HNC patients along with normal controls were included in this study. PCR-single-strand conformation polymorphism and DNA sequencing were used to analyze the whole coding region of OGG1 gene. Sequence analysis revealed eight novel mutations (six missense and two frame shift mutations). Frequencies of missense mutations, Asp267Asn, Ser279Gly and Ile253Phe were 0.12, 0.13 and 0.06 respectively. Frequencies of other missense mutations, 1578A> T, 1582C> T and Ala399Glu (1542C> A) were 0.13, 0.13 and 0.16, whereas values for the frame shift mutations 1582insG and 1543-1544delCT were 0.13 and 0.16. In our study, incidence of these mutations was found higher in oral cancers (p<0.002) and in smokers (p<0.002) when compared with other sites of HNC and nonsmokers, respectively. Our finding suggests that these germline mutations in OGG1 gene contribute to risk of developing HNC.     

Viscosities of dilute solutions of poly(tetrahydrofurfuryl methacrylate)

The intrinsic viscosities of seven fractions (from M?_n = 1,69.10⁵ to M?_n = 6,13.10⁵) of poly(tetrahydrofurfuryl methacrylate) in eleven solvents at temperatures between 30° and 50° show the following order: tetrachloroethane > dichloroethane > tetrahydrofuran > chloroform > benzene > bromobenzene > ethyl acetate > carbon tetrachloride > methyl pentyl ketone > acetone > 2-hydroxymethyltetrahydrofuran. Values of HUGGINS slope constants range between 0,34 to 0,48 for the unfractionated polymer and the magnitudes of a and k in the expression [η] = kM^a show little variations with temperature in case of good solvents whereas the opposite is observed in case of poor solvents. The theta temperature for 2-hydroxymethyltetrahydrofuran containing 20% methanol is 31,2 ± 0,3° and 3,49, 5,72, and 4,97 are the values for K₀.10⁴, (r /M)^1/2.10⁹ and (r /Z)^1/2.10⁸, respectively.