Nitric Oxide Administration Using an Oxygen Hood: A Pilot Trial

Background

We have shown earlier that inhaled nitric oxide (iNO) administered by oxygen hood reduces pulmonary hypertension in an animal model (J Perinatol 2002; 22:50-6). Our objective in this study was to determine feasibility of iNO by oxygen hood in neonates with elevated alveolar-arterial oxygen gradients (A-aDO₂).

Methods/Principal Findings

Masked randomized controlled pilot trial. Inclusion criteria were: gestation≥34 weeks, age<7 days, with post-ductal arterial line, and A-aDO₂ 400–600. Infants were randomized to study gas (iNO 20 ppm or equivalent O₂ flow) for 1 hr which was then weaned over the next 4 hours. Primary outcome was PaO₂ one hour post-randomization. Four infants each were randomized to iNO or O₂ (controls). Two of the four infants given iNO had an increase in PaO₂ of >100 torr, while oxygenation was unchanged in the controls. Methemoglobinemia and other adverse effects were not noted in any infant. Environmental levels of NO and NO₂ were minimal (<1 ppm) at >0.3 m from the hood.

Conclusions

Administration of iNO by oxygen hood is feasible. Larger randomized controlled trials are required to measure the efficacy and determine an appropriate target population for this technique.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00041548","term_id":"NCT00041548"}}NCT00041548     

Cellulose hydrolysis by immobilized <Emphasis Type="Italic">Trichoderma reesei</Emphasis> cellulase

Cellulose hydrolysis by immobilized Trichoderma reesei cellulase in the presence of a low viscosity ionic liquid, 1-ethyl-3-methylimidazolium diethyl phosphate (EMIM-DEP), was investigated. Preparation of the carrier-free immobilized cellulase was optimized with respect to concentration of the cross-linker and the type of precipitant. The addition of 2% (v/v) EMIM-DEP during hydrolysis gave an initial reaction rate 2.7 times higher than the hydrolysis rate with no ionic liquid. The initial yield after 2 h was 0.7 g glucose/g cellulose, and the carrier-free immobilized cellulase (CFIC) was effectively re-used five times.     

Fruit harvesting time and corresponding morphological changes of seed integuments influence in vitro seed germination of <Emphasis Type="Italic">Dendrobium nobile</Emphasis> Lindl.

In vitro asymbiotic seed germination of Dendrobium nobile varied significantly with fruit harvesting time and growth medium used for culturing seeds. Seeds harvested 129 days after pollination (DAP) possessing globular shaped embryos and a discontinuous cuticle layer showed a substantially greater germination on P668 medium. Alternatively, immature seeds harvested 96 and 116 DAP displayed a significantly lower germination response on various growth media. Most of the ovules at 96 DAP are in archesporial and megaspore mother cell stages, whereas the majority of ovules are mature and fertilized at 116 DAP. Mature seeds harvested 158 DAP also germinated at a higher frequency at Stage 5 (emergence of the first leaf) after 8 weeks of culture on different growth media indicating the absence of testa imposed dormancy in this endangered epiphytic orchid.     

Unusual intron in the second exon of a Type III polyketide synthase gene of Alpinia calcarata Rosc

Plant phenolic compounds form a valuable resource of secondary metabolites having a broad spectrum of biological activities. Type III polyketide synthases play a key role in the formation of basic structural skeleton of the phenolic compounds. As a group of medicinal plants, PKSs with novel features are expected in the genome of Zingiberaceae. The genomic exploration of PKS in Alpinia calcarata conducted in this study identified the presence of an unusual intron at the region forming the second exon of typical PKSs, forming a gateway information of distribution of novel PKSs in Zingiberaceae.     

Evaluation of green fluorescent protein as a reporter gene and phosphinothricin as the selective agent for achieving a higher recovery of transformants in cucumber (<Emphasis Type="Italic">Cucumis sativus</Emphasis> L. cv. Poinsett76) via <Emphasis Type="Italic">Agrobacterium tumefaciens</Emphasis>

Efficient Agrobacterium tumefaciens-mediated transformation and a higher recovery of transformed plants of cucumber cv. Poinsett76 were achieved via direct organogenesis from cotyledon explants. Stable transformants were obtained by inoculating explants with A. tumefaciens strains EHA105 or LBA4404, both harboring the binary vector pME508, which contains the neomycin phosphotransferase II (nptII) and phosphinothricin resistance genes (bar) conferring resistance to kanamycin and PPT, respectively, as selectable markers and the sgfp-tyg gene for the green fluorescent protein (GFP) as a visual marker driven by the constitutive CaMV35S promoter in the presence of acetosyringone (50 μM). Transformed shoots were obtained on MS Murashige and Skoog (Plant Physiol. 15: 473–497, 1962) medium supplemented with 1 mg L⁻¹ benzyladenine (BA), 20 mg L⁻¹ l-glutamine and 2 mg L⁻¹ phosphinothricin (PPT) or 100 mg L⁻¹ kanamycin. The regenerated shoots were examined in vivo using a hand-held long wave UV lamp for GFP expression. The GFP screening helped identify escapes and chimeric shoots at regular intervals to increase the growth of transformed shoots on cotyledon explants. Elongation and rooting of putative transformants were achieved on PPT (2 mg L⁻¹) containing MS media with 0.5 mg L⁻¹ gibberellic acid (GA₃) and 0.6 mg L⁻¹ indole butyric acid (IBA), respectively. PCR and Southern analyses confirmed the integration of the sgfp gene into the genome of T₀ and the progenies. T₁ segregation of transgenic progeny exhibited Mendelian inheritance of the transgene. The use of EHA105 resulted in 21% transformation efficiency compared to 8.5% when LBA4404 was used. This higher rate was greatly facilitated by PPT selection coupled with effective screening of transformants for GFP expression, thus making the protocol highly useful for the recovery of a higher number of transgenic cucumber plants.     

Terpenoid,Benzenoid, and Phenylpropanoid Compounds in the Floral Scent of <Emphasis Type="Italic">Vanda</Emphasis> Mimi Palmer

Vanda Mimi Palmer is the product of a cross between Vanda Tan Chay Yan and Vanda tessellata. The flower of this hybrid produces a sweet-smelling fragrance during day time at the open-flower stage. This study aimed to investigate the floral scent constituents in Vanda Mimi Palmer. Scent emission analysis of this orchid was carried out at different time points in a 24-h cycle and also at different floral developmental stages. A comparison was also made on the volatiles emitted by Vanda Mimi Palmer and both of its parents. Gas chromatography-mass spectrometry (GC-MS) analysis showed that the scent of Vanda Mimi Palmer was dominated by terpenoid, benzenoid, and phenylpropanoid compounds. The identified terpenoids were ocimene, linalool oxide, linalool, and nerolidol; while the benzenoid and phenylpropanoid compounds were methylbenzoate, benzyl acetate, phenylethanol, and phenylethyl acetate. The emission of terpenoid, benzenoid, and phenylpropanoid compounds was developmentally and temporally regulated. Comparison of the volatiles emitted by both of its parents showed that the scent of Vanda Mimi Palmer is dissimilar to that of its fragrant parent, V. tessellata.     

High affinity human antibody fragments to dengue virus non-structural protein 3

Background

The enzyme activities catalysed by flavivirus non-structural protein 3 (NS3) are essential for virus replication. They are distributed between the N-terminal protease domain in the first one-third and the C-terminal ATPase/helicase and nucleoside 5′ triphosphatase domain which forms the remainder of the 618-aa long protein.

Methodology/Principal Findings

In this study, dengue full-length NS3 protein with residues 49 to 66 of NS2B covalently attached via a flexible linker, was used as bait in biopanning with a naïve human Fab phage-display library. Using a range of truncated constructs spanning the NS2B cofactor region and the full-length NS3, 10 unique Fab were identified and characterized. Of these, monoclonal Fab 3F8 was shown to bind α3″ (residues 526 through 531) within subdomain III of the helicase domain. The antibody inhibits the ATPase and helicase activites of NS3 in biochemical assays and reduces DENV replication in HEK293 cells that were previously transfected with Fab 3F8 compared with mock transfected cells.

Conclusions/Significance

Antibodies such as 3F8 are valuable tools for studying the molecular mechanisms of flaviviral replication and for the monospecific detection of replicating dengue virus in vivo.     

CDD: a curated Entrez database of conserved domain alignments

The Conserved Domain Database (CDD) is now indexed as a separate database within the Entrez system and linked to other Entrez databases such as MEDLINE(R). This allows users to search for domain types by name, for example, or to view the domain architecture of any protein in Entrez's sequence database. CDD can be accessed on the WorldWideWeb at http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=cdd. Users may also employ the CD-Search service to identify conserved domains in new sequences, at http://www.ncbi.nlm.nih.gov/Structure/cdd/wrpsb.cgi. CD-Search results, and pre-computed links from Entrez's protein database, are calculated using the RPS-BLAST algorithm and Position Specific Score Matrices (PSSMs) derived from CDD alignments. CD-Searches are also run by default for protein-protein queries submitted to BLAST(R) at http://www.ncbi.nlm.nih.gov/BLAST. CDD mirrors the publicly available domain alignment collections SMART and PFAM, and now also contains alignment models curated at NCBI. Structure information is used to identify the core substructure likely to be present in all family members, and to produce sequence alignments consistent with structure conservation. This alignment model allows NCBI curators to annotate 'columns' corresponding to functional sites conserved among family members.