Lack of BCG vaccination and other risk factors for bacteraemia in severely malnourished children with pneumonia.

We sought to examine the factors associated with bacteraemia and their outcome in children with pneumonia and severe acute malnutrition (SAM). All SAM children of either sex, aged 0-59 months, admitted to the Dhaka Hospital of the International Centre for Diarrhoeal Disease Research, Bangladesh with radiologically confirmed pneumonia from April 2011 to July 2012 were enrolled (n = 405). Comparison was made between pneumonic SAM children with (cases = 18), and without (controls = 387) bacteraemia. The death rate was significantly higher in cases than controls (28% vs. 8%, P < 0·01). In logistic regression analysis, after adjusting for potential confounders, the SAM children with pneumonia and bacteraemia more often had a history of lack of bacillus Calmette-Guérin (BCG) vaccination (odds ratio 7·39, 95% confidence interval 1·67-32·73, P < 0·01). The results indicate the importance of continuation of BCG vaccination which may provide benefit beyond its primary purpose.

Direct targeting of light signals to a promoter element-bound transcription factor.

Light signals perceived by the phytochrome family of sensory photoreceptors are transduced to photoresponsive genes by an unknown mechanism. Here, we show that the basic helix-loop-helix transcription factor PIF3 binds specifically to a G-box DNA-sequence motif present in various light-regulated gene promoters, and that phytochrome B binds reversibly to G-box-bound PIF3 specifically upon light-triggered conversion of the photoreceptor to its biologically active conformer. We suggest that the phytochromes may function as integral light-switchable components of transcriptional regulator complexes, permitting continuous and immediate sensing of changes in this environmental signal directly at target gene promoters.

Cre/ lox site-specific recombination controls the excision of a transgene from the rice genome.

The Cre/ lox site-specific recombination controls the excision of a target DNA segment by recombination between two loxsites flanking it, mediated by the Cre recombinase. We have studied the functional expression of the Cre/ lox system to excise a transgene from the rice genome. We developed transgenic plants carrying the target gene, hygromycin phosphotransferase ( hpt) flanked by two lox sites and transgenic plants harboring the Cre gene. Each lox plant was crossed with each Cre plant reciprocally. In the Cre /lox hybrid plants, the Cre recombinase mediates recombination between two lox sites, resulting in excision of the hpt gene. The recombination event could be detected because it places the CaMV 35S promoter of the hpt gene adjacent to a promoterless gusA gene; as a result the gusA gene is activated and its expression could be visualized. In 73 Cre /lox hybrid plants from various crosses of T0 transgenic plants, 19 expressed GUS, and in 132 Cre /lox hybrid plants from crosses of T2 transgenic plants, 77 showed GUS expression. Molecular data proved the excision event occurred in all the GUS(+) plants. Recombination occurred with high efficiency at the early germinal stage, or randomly during somatic development stages.

Alkaloids of Zanthoxylum budrunga.

Pseudophrynamine, lunacridine and the new compound 2-(2',4',6'-trimethyl-heptenyl)-4-quinozolone were isolated from the leaves of Zanthoxylum budrunga.

An anaerobically inducible early (aie) gene family from rice.

One of the major abiotic stresses that affect plant growth and development is anoxia or hypoxia. Plants respond to anoxia by regulation of gene expression at both the transcriptional and translational levels. Genes involved in such regulation are expected to be expressed soon after onset of anoxia. To date, however, anaerobically regulated genes that have been characterized predominantly encode enzymes for sugar phosphate metabolism, and are induced after several hours of anaerobic conditions. Early induced genes, those responding after 1-2 h of anoxia, have not been studied extensively. To study the early anaerobic response we investigated the most flooding-tolerant variety of rice, FR13A (flood-resistant). We used differential display techniques to identify cDNA fragments representing mRNAs that are induced within 90 min of anoxia. We isolated two cDNA fragments and one full-length cDNA that were induced to high levels. These cDNAs were found to be members of a family of 2-3 genes, which were called the aie (anaerobically inducible early) gene family. Northern blot analyses showed that the mRNA levels of aie genes peaked after 1.5 to 3 h of anoxia and were still at high levels after 72 h of anoxia. RNase protection assays showed 4-5 different protected bands indicating multiple transcripts from the aie gene family. Sequence analyses of the full-length cDNA showed an open reading frame that putatively encodes a 14 kDa protein of 127 amino acid residues. Neither the nucleotide nor the deduced amino acid sequences of this gene showed any significant homology to any known genes or proteins present in the GenBank or SwissProt databases. This novel gene, that is induced so early under anoxia in plants, may play an important role in plant metabolism under anaerobic conditions.

GIGANTEA is a nuclear protein involved in phytochrome signaling in Arabidopsis.

In a genetic screen of available T-DNA-mutagenized Arabidopsis populations for loci potentially involved in phytochrome (phy) signaling, we identified a mutant that displayed reduced seedling deetiolation under continuous red light, but little if any change in responsiveness to continuous far-red light. This behavior suggests disruption of phyB, but not phyA signaling. We have cloned the mutant locus by using the T-DNA insertion and found that the disrupted gene is identical to the recently described GIGANTEA (GI) gene identified as being involved in control of flowering time. The encoded GI polypeptide has no sequence similarity to any known proteins in the database. However, by using beta-glucuronidase-GI and green fluorescent protein-GI fusion constructs, we have shown that GI is constitutively targeted to the nucleus in transient transfection assays. Optical sectioning by using the green fluorescent protein-GI fusion protein showed green fluorescence throughout the nucleoplasm. Thus, contrary to previous computer-based predictions that GI would be an integral plasma membrane-localized polypeptide, the data here indicate that it is a nucleoplasmically localized protein. This result is consistent with the proposed role in phyB signaling, given recent evidence that early phy signaling events are nuclear localized.

A prospective study of the risk of diarrheal diseases according to the nutritional status of children.

Prospective field data were employed to examined the effect of child malnutrition on the subsequent risk of diarrhea among preschool children in rural Bangladesh. A total of 2019 children aged 12-23 months were classified according to weight-for-age, weight-for-height, and height-for-age of the Harvard median standard. Over a 24-month prospective period, diarrheal hospitalization rates among the children were matched to the initial anthropometric assessment. No differences in diarrheal hospitalization rates were noted for the children according to initial nutritional status. Another group of 207 children under five years of age were classified according to weight-for-age and their diarrheal attack rate in the field was followed prospectively for one year after nutritional assessment. Again, no differences in field diarrheal attack rates were noted between children of varying nutritional status categories. The nutritional status of the 207 children was then defined as monthly growth velocity (kilogram change in body weight, per cent change of initial body weight, and per cent change in weight-for-age) and the diarrheal attack rate for the subsequent one month period was observed. No differences in attack rates were noted between nutritional groups. The study failed to demonstrate that nutritional status defined by anthropometry was associated with the subsequent risk of diarrheal diseases.

SRL1: a new locus specific to the phyB-signaling pathway in Arabidopsis.

As part of an effort to isolate new Arabidopsis mutants specifically defective in responsiveness to red light, we identified srl1 (short hypocotyl in red light) by screening an EMS-mutagenized M2 population derived from a phytochrome B (phyB)-overexpressor line (ABO). The srl1 mutant shows enhanced responsiveness to continuous red but not far-red light, in both wild-type and ABO backgrounds, consistent with involvement in the phyB-signaling pathway but not that of phyA. The hypersensitive phenotype of srl1 is not due to overexpression of endogenous phyA or phyB, and the locus maps to the center of chromosome 2, distinct from any other known photomorphogenic mutants. srl1 seedlings display enhancement of several phyB-mediated responses, including shorter hypocotyls, more expanded cotyledons, shorter petioles and modestly higher levels of CAB gene expression under red light than the wild type. Double mutant analyses show that the hypersensitive phenotype of srl1 is completely phyB-dependent. The data suggest, therefore, that SRL1 may encode a negatively acting component specific to the phyB-signaling pathway.

Characterization of pyruvate decarboxylase genes from rice.

The pdc1 gene encoding pyruvate decarboxylase has been isolated and sequenced from an IR54 rice genomic library. In contrast to a previously isolated intron-less rice genomic pdc, pRgpdc3, this gene contains five intervening introns in the coding region and corresponds to a cDNA clone, pRcpdc1, isolated from an IR54-cDNA library constructed from anaerobically-induced mRNAs. Comparison of the deduced amino acid sequence of this gene with that of the rice pdc2 and pdc3 showed 88% and 89% similarity, and 78% and 79% identity, respectively. Southern blots indicated that more than three genes constitute the pdc gene family in rice. pdc1 is highly inducible under anaerobic conditions. Rice pdc2 is also inducible by anoxia but to a much lesser extent than pdc1.