Tomato necrotic ringspot virus, a new tospovirus isolated in Thailand

A new tospovirus isolated from naturally infected tomato plants grown in Nakhon Pathom province (Thailand) was characterized. Infected plants showed symptoms consisting of necrotic spots, necrotic ringspots and stem necrosis. This virus was detected using general antibodies that could recognize watermelon silver mottle virus (WSMoV), capsicum chlorosis virus (CaCV) and melon yellow spot virus (MYSV). However, it did not react with specific monoclonal antibodies (MAbs) to WSMoV and CaCV or a specific MAb to MYSV. The complete nucleotide sequences of S and M RNAs of the virus were determined. They were 3,023 and 4,716 nucleotides in length, respectively, and contained two ORFs in an ambisense arrangement. Sequence analysis indicated that amino acid sequence of the N protein shared 58.2%, 56.0% and 51.8% identity with those of CaCV, WSMoV and MYSV, respectively. The virus was experimentally transmitted by Thrips palmi and Ceratothripoides claratris. Based on our results, we conclude that this tospovirus isolate should be considered a member of a new species. The name tomato necrotic ringspot virus (TNRV) is proposed for this tospovirus.     

6-month evaluation of JinHuang Chinese herbal medicine study in asymptomatic HIV infected Thais

Good results of in vitro study of anti-HIV effects of JinHuang, a Chinese herbal medicine led to in vivo study of safety and efficacy among asymptomatic HIV infected individuals. It was a prospective open study of 21 asymptomatic HIV infected Thai volunteers. Twelve and 9 were female and male, respectively, with mean age of 29.24 +/- 3.94 years. JinHuang preparation, 6 capsules and 2 bottles of liquid formula orally three times a day, was given on an outpatient basis initially for 6 months. Regular close monitoring and follow-up were done. The side effects reported included : increased bowel movements (81%), vague taste, and smell of drug after initiation (52%). No serious adverse event related to JinHuang was detected during study. No significant changes in terms of log viral load and CD4 count were observed after 6-months' duration. Most of the patients felt that the quality of life was better in terms of better appetite, good sleep and healthy during study participation, however, these were subjective.     

Heterogeneous disease-propagating stem cells in juvenile myelomonocytic leukemia

Juvenile myelomonocytic leukemia (JMML) is a poor-prognosis childhood leukemia usually caused by RAS-pathway mutations. The cellular hierarchy in JMML is poorly characterized, including the identity of leukemia stem cells (LSCs). FACS and single-cell RNA sequencing reveal marked heterogeneity of JMML hematopoietic stem/progenitor cells (HSPCs), including an aberrant Lin⁻CD34⁺CD38⁻CD90⁺CD45RA⁺ population. Single-cell HSPC index-sorting and clonogenic assays show that (1) all somatic mutations can be backtracked to the phenotypic HSC compartment, with RAS-pathway mutations as a “first hit,” (2) mutations are acquired with both linear and branching patterns of clonal evolution, and (3) mutant HSPCs are present after allogeneic HSC transplant before molecular/clinical evidence of relapse. Stem cell assays reveal interpatient heterogeneity of JMML LSCs, which are present in, but not confined to, the phenotypic HSC compartment. RNA sequencing of JMML LSC reveals up-regulation of stem cell and fetal genes (HLF, MEIS1, CNN3, VNN2, and HMGA2) and candidate therapeutic targets/biomarkers (MTOR, SLC2A1, and CD96), paving the way for LSC-directed disease monitoring and therapy in this disease.     

DNA-binding factor CTCF and long-range gene interactions in V(D)J recombination and oncogene activation

Regulation of V(D)J recombination events at immunoglobulin (Ig) and T-cell receptor loci in lymphoid cells is complex and achieved via changes in substrate accessibility. Various studies over the last year have identified the DNA-binding zinc-finger protein CCCTC-binding factor (CTCF) as a crucial regulator of long-range chromatin interactions. CTCF often controls specific interactions by preventing inappropriate communication between neighboring regulatory elements or independent chromatin domains. Although recent gene targeting experiments demonstrated that the presence of the CTCF protein is not required for the process of V(D)J recombination per se, CTCF turned out to be essential to control order, lineage specificity and to balance the Ig V gene repertoire. Moreover, CTCF was shown to restrict activity of κ enhancer elements to the Ig κ locus. In this review, we discuss CTCF function in the regulation of V(D)J recombination on the basis of established knowledge on CTCF-mediated chromatin loop domains in various other loci, including the imprinted H19-Igf2 locus as well as the complex β-globin, MHC class II and IFN-γ loci. Moreover, we discuss that loss of CTCF-mediated restriction of enhancer activity may well contribute to oncogenic activation, when in chromosomal translocations Ig enhancer elements and oncogenes appear in a novel genomic context.     

A critical appraisal of a systematic review: Sokol J, Jacob SE, Bohn D: Inhaled nitric oxide for acute hypoxemic respiratory failure in children and adults. Cochrane Database Syst Rev 2003 (1): CD002787.

OBJECTIVE: To review the findings and discuss the implications of the use of inhaled nitric oxide for acute hypoxemic respiratory failure in patients beyond the neonatal period. DESIGN: A critical appraisal of a systematic review. Findings: The authors conducted a systematic review with meta-analysis to determine the effect of inhaled nitric oxide on clinical outcomes of patients with acute hypoxemic respiratory failure. The outcomes included mortality, changes in oxygenation, ventilator-free days, duration of intensive care and hospital stays, and adverse effects. It was a high-quality systematic review provided with strict entry criteria, an extensive literature search, and thorough critical appraisals. Only five trials (n = 623) met entry criteria. Inhaled nitric oxide had no effect on mortality in studies without crossover of treatment failures to open-label inhaled nitric oxide (relative risk, 0.98; 95% confidence interval, 0.66-1.44). A statistically significant improvement in oxygenation was observed in one study. The effect, however, was observed only in the first 4 days of treatment and was not clinically significant. The heterogeneity in study findings precluded meta-analyses of other clinical outcomes and adverse effects in the selected studies. CONCLUSIONS: There is insufficient evidence to determine whether inhaled nitric oxide is beneficial or harmful for acute hypoxemic respiratory failure in children and adults. While awaiting further studies to prove its benefit, inhaled nitric oxide should not either be recommended as a standard management or excluded for the treatment of acute hypoxemic respiratory failure.