Diversity and vertical distribution of epiphytic macrolichens in lowland rain forest and lowland cloud forest of French Guiana

Recent work on bryophyte diversity in lowland forests of northern South America has suggested the existence of a new type of cloud forest, the “tropical lowland cloud forest” (LCF). LCF occurs in river valleys with high air humidity and radiation fog, and is rich in epiphytes. We explored the lichenological characteristics of putative LCF in a lowland area (200–400 m a.s.l.) near Saül, central French Guiana, using macrolichens (including large crustose species) as indicator taxa. We analyzed macrolichen diversity on 16 trees in two 1 ha plots, in LCF and in lowland rain forest without fog (LRF). Sampling efficiency was ca. 80% in both forest types. Canopies of both LRF and LCF were richer in lichen species than understory trunks. Species richness of macrolichens was rather similar in the two forest types but species composition was significantly different. Cyanolichen richness in LCF was ca. 2.5 times higher than in LRF; in contrast, LRF had 4 times more species of green-algal Parmeliaceae. Our study suggests that cyanolichens except for Coccocarpiaceae serve as indicators of LCF. We explain the detected diversity patterns by differences in water availability due to fog precipitation and higher humidity. This is indicated by the higher relative air humidity in the lowland cloud forest, which was >6% higher than in the rain forest.     

Site-specific labeling of ‘second generation’ annexin V with 99mTc(CO)3 for improved imaging of apoptosis in vivo

In this study ‘second generation’ AnxV was specifically labeled with ^99mTc in three different ways outside the binding region of the protein to obtain an improved target-to-background activity ratio. The compounds were tested in vitro and in vivo in normal mice and in a model of hepatic apoptosis (anti-Fas mAb). The apoptosis binding was most prominent for the HIS-tagged ‘second generation’ AnxV labeled with ^99mTc(CO)₃ in comparison to ^99mTc-HYNIC-cys-AnxV and ^99mTc(CO)₃-DTPA-cys-AnxV.     

Multilocus species identification and fungal DNA barcoding: insights from blue stain fungal symbionts of the mountain pine beetle

There is strong community-wide interest in applying molecular techniques to fungal species delimitation and identification, but selection of a standardized region or regions of the genome has not been finalized. A single marker, the ribosomal DNA internal transcribed spacer region, has frequently been suggested as the standard for fungi. We used a group of closely related blue stain fungi associated with the mountain pine beetle (Dendroctonus ponderosae Hopkins) to examine the success of such single-locus species identification, comparing the internal transcribed spacer with four other nuclear markers. We demonstrate that single loci varied in their utility for identifying the six fungal species examined, while use of multiple loci was consistently successful. In a literature survey of 21 similar studies, individual loci were also highly variable in their ability to provide consistent species identifications and were less successful than multilocus diagnostics. Accurate species identification is the essence of any molecular diagnostic system, and this consideration should be central to locus selection. Moreover, our study and the literature survey demonstrate the value of using closely related species as the proving ground for developing a molecular identification system. We advocate use of a multilocus barcode approach that is similar to the practice employed by the plant barcode community, rather than reliance on a single locus.     

Efficacy of three microbiological monitoring methods in a ventilated cage rack

The use of individually ventilated caging (IVC) to house mice presents new challenges for effective microbiological monitoring. Methods that exploit the characteristics of IVC have been developed, but to the authors' knowledge, their efficacy has not been systematically investigated. Air exhausted from the IVC rack can be monitored, using sentinels housed in cages that receive rack exhaust air as their supply air, or using filters placed on the exhaust air port. To aid laboratory animal personnel in making informed decisions about effective methods for microbiological monitoring of mice in IVC, the efficacy of air monitoring methods was compared with that of contact and soiled bedding sentinel monitoring. Mice were infected with mouse hepatitis virus (MHV), mouse parvovirus (MPV), murine rotavirus (agent of epizootic diarrhea of mice [EDIM]), Sendai virus (SV), or Helicobacter spp. All agents were detected using contact sentinels. Mouse hepatitis virus was effectively detected in air and soiled bedding sentinels, and SV was detected in air sentinels only. Mouse parvovirus and Helicobacter spp. were transmitted in soiled bedding, but the efficacy of transfer was dependent on the frequency and dilution of soiled bedding transferred. Results were similar when the IVC rack was operated under positive or negative air pressure. Filters were more effective at detecting MHV and SV than they were at detecting MPV. Exposure of sentinels or filters to exhaust air was effective at detecting several infectious agents, and use of these methods could increase the efficacy of microbiological monitoring programs, especially if used with soiled bedding sentinels. In contemporary mouse colonies, a multi-faceted approach to microbiological monitoring is recommended.     

Mutations affecting retina development in Medaka

In a large scale mutagenesis screen of Medaka we identified 60 recessive zygotic mutations that affect retina development. Based on the onset and type of phenotypic abnormalities, the mutants were grouped into five categories: the first includes 11 mutants that are affected in neural plate and optic vesicle formation. The second group comprises 15 mutants that are impaired in optic vesicle growth. The third group includes 18 mutants that are affected in optic cup development. The fourth group contains 13 mutants with defects in retinal differentiation. 12 of these have smaller eyes, whereas one mutation results in enlarged eyes. The fifth group consists of three mutants with defects in retinal pigmentation. The collection of mutants will be used to address the molecular genetic mechanisms underlying vertebrate eye formation.     

Partial purification and properties of a 36-kDa 1-aminocyclopropane-1-carboxylate N-malonyltransferase from mung bean

A 36-kDa 1-aminocyclopropane-1-carboxylate (ACC) N-malonyltransferase, which converts the ethylene precursor ACC into the conjugated derivative malonyl-ACC (MACC), has been isolated from etiolated mung bean ( Vigna radiata ) hypocotyls, and partially purified in a four-step procedure. The enzyme is stimulated about 7-fold by 100 m M K⁺ salts or 0.5 m M Co²⁺ salts, and is inhibited competitively by D-phenylalanine (K_i= 1.3 m M ) and non competitively by CoASH (0.3 m M ). Beside malonyl-CoA, it is capable to use succinyl-CoA as an acyl donor. The 36-kDa enzyme described here exhibits a lower optimum temperature (40°C) and a 7- or 3-fold lower apparent K_m for ACC (68 μ M ) and malonyl-CoA (74 μ M ), respectively, when compared with its 55 kDa isoform already isolated from the same plant material. This data support the idea that several isoforms of ACC N-malonyltransferase exist in plants. These isoforms may play a differential role in regulating the availability of ACC, and consequently the rate of ethylene production, as well as detoxifying cells from D-amino acids.     

Translating niche features: Modelling differential exposure of Argentine reptiles to global climate change

Global climate change affects the distributions of ectotherms and may be the cause of several conservation problems, such as great displacement of climatic suitable spaces for species and, consequently, important reductions of the extent of liveable places, threatening the existence of many of them. Species exposure (and hence vulnerability) to global climate change is linked to features of their climatic niches (such as the relative position of the inhabited localities of each species in the climatic space), and therefore to characteristics of their geographic ranges (such as the extent of the distributions or altitudinal range inhabited by the species). In order to analyze the pattern of response of Argentine reptiles to global climate change, we ran phylogenetic generalized least squares models using species exposure to global climate change as a response variable, and (i) niche properties (breadth and position of the species in the climate space) and (ii) general features of the distribution of species (maximum latitude, altitudinal range, maximum elevation, distributional range and proximity to the most important dispersal barrier) as predictors. Our results suggest that the best way to explain climate change exposure is by combining breadth and position of climatic niche of the species or combining geographic features that are indicators of both niche characteristics. Our best model shows that in our study area, species with the narrowest distributional ranges that also inhabit the highest elevations are the most exposed to the effects of global climate change. In this sense, reptile species from Yungas, Puna and Andes ecoregions could be especially vulnerable to the effects of climate change. We believe that these types of models may represent an interesting tool for determining species and places particularly threatened by the effects of global climate change, which should be strongly considered in conservation planning.     

Relationship between Urinary Level of Phytate and Valvular Calcification in an Elderly Population: A Cross-Sectional Study

Pathological calcification generally consists of the formation of solid deposits of hydroxyapatite (calcium phosphate) in soft tissues. Supersaturation is the thermodynamic driving force for crystallization, so it is believed that higher blood levels of calcium and phosphate increase the risk of cardiovascular calcification. However several factors can promote or inhibit the natural process of pathological calcification. This cross-sectional study evaluated the relationship between physiological levels of urinary phytate and heart valve calcification in a population of elderly out subjects. A population of 188 elderly subjects (mean age: 68 years) was studied. Valve calcification was measured by echocardiography. Phytate determination was performed from a urine sample and data on blood chemistry, end-systolic volume, concomitant diseases, cardiovascular risk factors, medication usage and food were obtained. The study population was classified in three tertiles according to level of urinary phytate: low (<0.610 μM), intermediate (0.61–1.21 μM), and high (>1.21 μM). Subjects with higher levels of urinary phytate had less mitral annulus calcification and were less likely to have diabetes and hypercholesterolemia. In the multivariate analysis, age, serum phosphorous, leukocytes total count and urinary phytate excretion appeared as independent factors predictive of presence of mitral annulus calcification. There was an inverse correlation between urinary phytate content and mitral annulus calcification in our population of elderly out subjects. These results suggest that consumption of phytate-rich foods may help to prevent cardiovascular calcification evolution.     

Stanniocalcin-1 Reduces Tumor Size in Human Hepatocellular Carcinoma

Growing evidence has revealed high expression levels of stanniocalcin-1 (STC1) in different types of human cancers. Numerous experimental studies using cancer cell lines demonstrated the involvement of STC1 in inflammatory and apoptotic processes; however the role of STC1 in carcinogenesis remains elusive. Hepatocellular carcinoma (HCC) an exemplified model of inflammation-related cancer, represents a paradigm of studying the association between STC1 and tumor development. Therefore, we conducted a statistical analysis on the expression levels of STC1 using clinicopathological data from 216 HCC patients. We found that STC1 was upregulated in the tumor tissues and its expression levels was positively correlated with the levels of interleukin (IL)-6 and IL-8. Intriguingly tumors with greater expression levels of STC1 (tumor/normal ≥ 2) were significantly smaller than the lower level (tumor/normal<2) samples (p = 0.008). A pharmacological approach was implemented to reveal the functional correlation between STC1 and the ILs in the HCC cell-lines. IL-6 and IL-8 treatment of Hep3B cells induced STC1 expression. Lentiviral-based STC1 overexpression in Hep3B and MHCC-97L cells however showed inhibitory action on the pro-migratory effects of IL-6 and IL-8 and reduced size of tumor spheroids. The inhibitory effect of STC1 on tumor growth was confirmed in vivo using the stable STC1-overexpressing 97L cells on a mouse xenograft model. Genetic analysis of the xenografts derived from the STC1-overexpressing 97L cells, showed upregulation of the pro-apoptotic genes interleukin-12 and NOD-like receptor family, pyrin domain-containing 3. Collectively, the anti-inflammatory and pro-apoptotic functions of STC1 were suggested to relate its inhibitory effect on the growth of HCC cells. This study supports the notion that STC1 may be a potential therapeutic target for inflammatory tumors in HCC patients.