Effect of colony morphology variation of <Emphasis Type="Italic">Burkholderia pseudomallei</Emphasis> on intracellular survival and resistance to antimicrobial environments in human macrophages in vitro

Background  

Primary diagnostic cultures from patients with melioidosis demonstrate variation in colony morphology of the causative organism, Burkholderia pseudomallei. Variable morphology is associated with changes in the expression of a range of putative virulence factors. This study investigated the effect of B. pseudomallei colony variation on survival in the human macrophage cell line U937 and under laboratory conditions simulating conditions within the macrophage milieu. Isogenic colony morphology types II and III were generated from 5 parental type I B. pseudomallei isolates using nutritional limitation. Survival of types II and III were compared with type I for all assays.     

Variation in heat shock proteins within tropical and desert species of poeciliid fishes

The 70-kilodalton heat shock protein (hsp70) family of molecular chaperones, which contains both stress-inducible and normally abundant constitutive members, is highly conserved across distantly related taxa. Analysis of this protein family in individuals from an outbred population of tropical topminnows, Poeciliopsis gracilis, showed that while constitutive hsp70 family members showed no variation in protein isoforms, inducibly synthesized hsp70 was polymorphic. Several species of Poeciliopsis adapted to desert environments exhibited lower levels of inducible hsp70 polymorphism than the tropical species, but constitutive forms were identical to those in P. gracilis, as they were in the confamilial species Gambusia affinis. These differences suggest that inducible and constitutive members of this family are under different evolutionary constraints and may indicate differences in their function within the cell. Also, northern desert species of Poeciliopsis synthesize a subset of the inducible hsp70 isoforms seen in tropical species. This distribution supports the theory that ancestral tropical fish migrated northward and colonized desert streams; the subsequent decrease in variation of inducible hsp70 may have been due to genetic drift or a consequence of adaptation to the desert environment. Higher levels of variability were found when the 30- kilodalton heat shock protein (hsp30) family was analyzed within different strains of two desert species of Poeciliopsis and also in wild-caught individuals of Gambusia affinis. In both cases the distribution of hsp30 isoform diversity was similar to that seen previously with allozyme polymorphisms.      

The cover of living and dead corals from airborne remote sensing

Trends in coral cover are widely used to indicate the health of coral reefs but are costly to obtain from field survey over large areas. In situ studies of reflected spectra at the coral surface show that living and recently dead colonies can be distinguished. Here, we investigate whether such spectral differences can be detected using an airborne remote sensing instrument. The Compact Airborne Spectrographic Imager (Itres Research Ltd, Canada) was flown in two configurations: 10 spectral bands with 1-m² pixels and 6 spectral bands with 0.25-m² pixels. First, we show that an instrument with 10 spectral bands possesses adequate spectral resolution to distinguish living Porites, living Pocillopora spp., partially dead Porites, recently dead Porites (total colony mortality within 6 months), old dead (>6 months) Porites, Halimeda spp., and coralline red algae when there is no water column to confuse spectra. All substrata were distinguished using fourth-order spectral derivatives around 538 nm and 562 nm. Then, at a shallow site (Tivaru) at Rangiroa Atoll, Tuamotu Archipelago (French Polynesia), we show that live and dead coral can be distinguished from the air to a depth of at least 4 m using first- and fourth-order spectral derivatives between 562–580 nm. However, partially dead and recently dead Porites colonies could not be distinguished from an airborne platform. Spectral differences among substrata are then exploited to predict the cover of reef substrata in ten 25-m² plots at nearby Motu Nuhi (max depth 8 m). The actual cover in these plots was determined in situ using quadrats with a 0.01-m² grid. Considerable disparity occurred between field and image-based measures of substrate cover within individual 25-m² quadrats. At this small scale, disparity, measured as the absolute difference in cover between field and remote-sensing methods, reached 25% in some substrata but was always less than 10% for living coral (99% of which consisted of Porites spp.). At the scale of the reef (all ten 25-m² quadrats), however, disparities in percent cover between imagery and field data were less than 10% for all substrata and extremely low for some classes (e.g. <3% for living Porites, recently dead Porites and Halimeda). The least accurately estimated substrata were sand and coralline red algae, which were overestimated by absolute values 7.9% and 6.6%, respectively. The precision of sampling was similar for field and remote-sensing methods: field methods required 19 plots to detect a 10% difference in coral cover among three reefs with a statistical power of 95%. Remote-sensing methods required 21 plots. However, it took 1 h to acquire imagery over 92,500 m² of reef, which represents 3,700 plots of 25 m² each, compared with 3 days to survey 10 such plots underwater. There were no significant differences in accuracy between 1-m² and 0.25-m² image resolutions, suggesting that the advantage of using smaller pixels is offset by reduced spectral information and an increase in noise (noise was observed to be 1.6–1.8 times greater in 0.25-m² pixels). We show that airborne remote sensing can be used to monitor coral and algal cover over large areas, providing that water is shallow and clear, and that brown fleshy macroalgae are scarce, that depth is known independently (e.g. from sonar survey).     

Human pluripotent stem cells produce natural killer cells that mediate anti-HIV-1 activity by utilizing diverse cellular mechanisms

Cell-based therapies against HIV/AIDS have been gaining increased interest. Natural killer (NK) cells are a key component of the innate immune system with the ability to kill diverse tumor cells and virus-infected cells. While NK cells have been shown to play an important role in the control of HIV-1 replication, their functional activities are often compromised in HIV-1-infected individuals. We have previously demonstrated the derivation of NK cells from human embryonic stem cells (hESCs) with the ability to potently kill multiple types of tumor cells both in vitro and in vivo. We now demonstrate the derivation of functional NK cells from human induced pluripotent stem cells (iPSCs). More importantly, both hESC- and iPSC-derived NK cells are able to inhibit HIV-1 NL4-3 infection of CEM-GFP cells. Additional studies using HIV-1-infected human primary CD4(+) T cells illustrated that hESC- and iPSC-derived NK cells suppress HIV-1 infection by at least three distinct cellular mechanisms: killing of infected targets through direct lysis, antibody-dependent cellular cytotoxicity, and production of chemokines and cytokines. Our results establish the potential to utilize hESC- and iPSC-derived NK cells to better understand anti-HIV-1 immunity and provide a novel cellular immunotherapeutic approach to treat HIV/AIDS.     

Induced suppression of genetic recombination in females of the Mediterranean fruit fly,Ceratitis capitata (Wied.), by translocation heterozygosity

Chromosomal recombination suppressors (RS) were induced and studied as part of a programme to induce and isolate temperature-sensitive recessive lethal factors, for subsequent use in genetic sexing mechanisms in the medfly, Ceratitis capitata (Wied.).The presence of induced RS factors was identified through the complete linkage of two morphologicla markers, ap and dc, located 18.25 recombination units apart. Adult +dc males were irradiated one day after emergence with 50 Gy in a cobalt-60 source. The irradiated males were mated to marked ap + females and the F1 females were crossed to ap dc males. A total of 5 heterozygous RS factors was isolated from 570 irradiated and screened chromosomes. Suppression of female recombination in the heterozygous lines ranged from 77.6% in RS 19 to 99.1% in RS 30B. Chromosomal analysis showed all RS lines to contain a single reciprocal translocation involving in all cases chromosome 3 and one other autosome. It appears that recombination between the two morphological markers is suppressed either through lethality conferred upon the gametes, which results from recombinant events taking place in the interstitial segment between the centromere and the translocation breakpoints, or through interference by the translocation heterozygote with the initiation or maintenance of cross-over synapsis thus preventing the appearance of cross-over products.All 5 translocations involved chromosome 3 and one of the other autosomes, providing the first evidence for a correlation between the ap-dc linkage group and chromosome 3.This work forms part of a joint FAO/IAEA research programme for the development of genetic sexing mechanisms for the Mediterranean fruit fly, Ceratitis capitata (Wied.).     

Species relationships in the genus Tulipa

The relationships of diploid and polyploid species belonging to the sub-section Eriostemones of the genus Tulipa have been investigated from the point of view of chromosome morphology, relative DNA values, and meiotic pairing properties. Karyotype morphology is basically the same for all species and eight principal chromosome classes can be distinguished. The range of DNA values obtained by Feulgen cytophotometry for the diploid species is relatively small and provides little assistance in ascertaining the pattern of ploidy involved in the evolution of the group. Partial asynapsis and reverse loop pairing in several of the diploids at pachytene reveals a degree of structural differentiation which may be the outcome of hybridity between species. Significantly, these anomalies are rarely encountered at the equivalent tetraploid levels and a scheme is proposed to account for this behaviour.     

Oligonucleotide hybridizations on glass supports: a novel linker for oligonucleotide synthesis and hybridization properties of oligonucleotides synthesised in situ.

A novel linker for the synthesis of oligonucleotides on a glass support is described. Oligonucleotides synthesised on the support remain tethered to the support after ammonia treatment and are shown to take part in sequence specific hybridisation reactions. These hybridizations were carried out with oligonucleotides synthesised on 'ballotini' solid sphere glass beads and microscope slides. The linker has a hexaethylene glycol spacer, bound to the glass via a glycidoxypropyl silane, terminating in a primary hydroxyl group that serves as starting point for automated or manual oligonucleotide synthesis.     

Molecular characterization of a cloned dolphin mitochondrial genome

Summary DNA clones have been isolated that span the complete mitochondrial (mt) genome of the dolphin,Cephalorhynchus commersonii. Hybridization experiments with purified primate mtDNA probes have established that there is close resemblance in the general organization of the dolphin mt genome and the terrestrial mammalian mt genomes. Sequences covering 2381 bp of the dolphin mt genome from the major noncoding region, three tRNA genes, and parts of the genes encoding cytochrome b, NADH dehydrogenase subunit 3 (ND3), and 16S rRNA have been compared with corresponding regions from other mammalian genomes. There is a general tendency throughout the sequenced regions for greater similarity between dolphin and bovine mt genomes than between dolphin and rodent or human mt genomes.     

2014 年中国医药市场发展蓝皮书——零售终端部分（Ⅲ）

介绍了中国零售药店发展概况、2007—2013 年中国药品零售终端规模以及中国药品零售行业集中度,并对中国药品零售终端主要大类的重点品牌前10 位进行了分析。