Genetic Signature of Rapid IHHNV (Infectious Hypodermal and Hematopoietic Necrosis Virus) Expansion in Wild Penaeus Shrimp Populations

Infectious hypodermal and hematopoietic necrosis virus (IHHNV) is a widely distributed single-stranded DNA parvovirus that has been responsible for major losses in wild and farmed penaeid shrimp populations on the northwestern Pacific coast of Mexico since the early 1990's. IHHNV has been considered a slow-evolving, stable virus because shrimp populations in this region have recovered to pre-epizootic levels, and limited nucleotide variation has been found in a small number of IHHNV isolates studied from this region. To gain insight into IHHNV evolutionary and population dynamics, we analyzed IHHNV capsid protein gene sequences from 89 Penaeus shrimp, along with 14 previously published sequences. Using Bayesian coalescent approaches, we calculated a mean rate of nucleotide substitution for IHHNV that was unexpectedly high (1.39×10−4 substitutions/site/year) and comparable to that reported for RNA viruses. We found more genetic diversity than previously reported for IHHNV isolates and highly significant subdivision among the viral populations in Mexican waters. Past changes in effective number of infections that we infer from Bayesian skyline plots closely correspond to IHHNV epizootiological historical records. Given the high evolutionary rate and the observed regional isolation of IHHNV in shrimp populations in the Gulf of California, we suggest regular monitoring of wild and farmed shrimp and restriction of shrimp movement as preventative measures for future viral outbreaks

Extensive Translatome Remodeling during ER Stress Response in Mammalian Cells

In this work we have described the translatome of two mammalian cell lines, NIH3T3 and Jurkat, by scoring the relative polysome association of ∼10,000 mRNA under normal and ER stress conditions. We have found that translation efficiencies of mRNA correlated poorly with transcript abundance, although a general tendency was observed so that the highest translation efficiencies were found in abundant mRNA. Despite the differences found between mouse (NIH3T3) and human (Jurkat) cells, both cell types share a common translatome composed by ∼800–900 mRNA that encode proteins involved in basic cellular functions. Upon stress, an extensive remodeling in translatomes was observed so that translation of ∼50% of mRNA was inhibited in both cell types, this effect being more dramatic for those mRNA that accounted for most of the cell translation. Interestingly, we found two subsets comprising 1000–1500 mRNA whose translation resisted or was induced by stress. Translation arrest resistant class includes many mRNA encoding aminoacyl tRNA synthetases, ATPases and enzymes involved in DNA replication and stress response such as BiP. This class of mRNA is characterized by high translation rates in both control and stress conditions. Translation inducible class includes mRNA whose translation was relieved after stress, showing a high enrichment in early response transcription factors of bZIP and zinc finger C2H2 classes. Unlike yeast, a general coordination between changes in translation and transcription upon stress (potentiation) was not observed in mammalian cells. Among the different features of mRNA analyzed, we found a relevant association of translation efficiency with the presence of upstream ATG in the 5′UTR and with the length of coding sequence of mRNA, and a looser association with other parameters such as the length and the G+C content of 5′UTR. A model for translatome remodeling during the acute phase of stress response in mammalian cells is proposed

L'Homme, 1984, tome 24 n°3-4.

Candotti and colleagues (1) reported the prevalence of a third strain of human erythrovirus, genotype 3 (V9), in the Ghanaian population and, in part, concluded that a genotype 1 (B19)-based assay failed to detect genotype 3 immunoglobulin G (IgG) in 38.5% of Ghanaian samples containing genotype 3 antibodies. We disagree with this conclusion for the following reasons

Comparative evaluation of treatment methods of neoadjuvant intra-arterial chemotherapy and chemoembolization by drug-saturated embospheres in II–IVa stages cervical cancer

Objective: comparative evaluation of treatment methods for neoadjuvant intra-arterial chemotherapy and chemoembolization by drug-saturated microspheres followed by surgical treatment in II–IVa stages cervical cancer.Materials and methods. This study presents the results of complex treatment in 209 patients (average age – 40.57 ± 8 years) with II– IVa stages cervical cancer and 384 endovascular interventions as the first stage of complex treatment in the period from 2010 to 2016. The scheme neoadjuvant intra-arterial chemotherapy was carboplatin (AUC6 intra-arterial) + irinotecan (200 mg/m2 intravenously on day 1) every 21 days. Radical surgical treatment was performed basically after 2 cycles of chemotherapy. Patients who did not respond sufficiently to neoadjuvant intra-arterial chemotherapy underwent a radical course of chemoradiation therapy according to the standard scheme.Results. The overall response to neoadjuvant intra-arterial chemotherapy was 84.8 % and 79 % of patients in groups of chemoinfusion and trans-arterial chemoembolization, respectively (p >0.05). Operability was higher in group of chemoinfusion (69 % versus 46.4 %) (p <0.01), and fewer patients with metastases to regional lymph nodes were revealed in this group (30.2 % versus 42 %), p <0.05. Overall and survival rate is statistically significantly better in group of chemoinfusion – 63.9 % and 61 % versus 43 % and 42 %, respectively, p <0.05. At the same time, statistically significant differences between the groups were revealed only at stages III–IVа cervical cancer. Radically operated patients, as expected, had a better prognosis (p <0.001). The age of patients, tumor differentiation and therapeutic pathomorphosis did not affect the prognosis of life.Conclusions. Neoadjuvant intra-arterial chemoinfusion and chemoembolization using irinotecan + carboplatin scheme are relatively safe treatment methods with acceptable toxicity and have a high cytotoxic effect. Patients in chemoinfusion group have a better prognosis compared with patients in chemoembolization group. Selective chemoembolization with subsequent surgical treatment or radiation therapy may be the treatment of choice for stage II cervical cancer complicated by bleeding

MicroRNA inhibition of translation initiation in vitro by targeting the cap-binding complex eIF4F

MicroRNAs (miRNAs) play an important role in gene regulatory networks in animals. Yet, the mechanistic details of their function in translation inhibition or messenger RNA (mRNA) destabilization remain controversial. To directly examine the earliest events in this process, we have developed an in vitro translation system using mouse Krebs-2 ascites cell-free extract that exhibits an authentic miRNA response. We show here that translation initiation, specifically the 5\u2032 cap recognition process, is repressed by endogenous let-7 miRNAs within the first 15 minutes of mRNA exposure to the extract when no destabilization of the transcript is observed. Our results indicate that inhibition of translation initiation is the earliest molecular event effected by miRNAs. Other mechanisms, such as mRNA degradation, may subsequently consolidate mRNA silencing