The genetic profile and molecular diagnosis of thiophanate-methyl resistant strains of Fusarium asiaticum in Japan

Fusarium asiaticum strains resistant to thiophanate-methyl were detected in four prefectures in Japan though their proportion in the total population was low in all instances. The F167Y or F200Y mutation in the β2-tubulin gene (FGSG06611.3) was detected in thiophanate-methyl resistant (TMR) strains. A PCR-based diagnostic method based on these mutations was developed and applied for all 17 TMR strains that have been detected so far in Japan. Three and 14 TMR strains were the F167Y and F200Y mutation types, respectively. Analysis by 11 variable number of tandem repeat markers showed that TMR strains from the same site had an identical genotype, while TMR strains from different sites were dissimilar. This result indicates that TMR strains did not spread clonally to the different sites.

Active tuberculosis and Mycobacterium tuberculosis latent infection in patients with HIV/AIDS

OBJECTIVES

Tuberculosis (TB) remains an important disease associated with HIV infection and AIDS in Brazil, even in a setting of free access to antiretroviral therapy (ART) and TB treatment. In previous studies, isoniazid therapy (IT) for latent infection with Mycobacterium tuberculosis (LIMTb) was found to reduce the risk of TB by 62% in patients with a tuberculin test (TT)>5 mm. The objectives of this study were to investigate the occurrence of TB, the prevalence of LIMTb and the coverage of the TT and IT, and to estimate the number of missed opportunities to prevent TB in patients with HIV/AIDS.

METHODS

A random sample of patients with HIV/AIDS was selected; data from the medical files were obtained, and a TT was performed in consenting subjects.

RESULTS

In the 203 subjects included in the study, TB occurrence was 13.3%, LIMTb prevalence was 20% and the coverage of the TT and IT was 59.2 and 55%, respectively. Patients with TB had a lower nadir CD4 cell count, but their CD4 recovery was comparable to that of non-TB patients. Patients with LIMTb always had a higher CD4 cell count.

CONCLUSIONS

By expanding the coverage of the TT and IT to nearly 100%, we could more than double the number of prevented cases of TB. TB prevention programmes must be reinforced to reduce the number of missed opportunities for diagnosis, and IT must be improved to reduce TB among patients with HIV/AIDS. Empowering patients with knowledge about TB, the preventive role of IT and the need for an annual TT may be the best way of lowing rates of TB in patients with HIV/AIDS.

Investigating the interaction of McN-A-343 with the M muscarinic receptor using its nitrogen mustard derivative and ACh mustard

BACKGROUND AND PURPOSE

We investigated how McN-A-343 inhibited the alkylation of the M(1) muscarinic receptor by its nitrogen mustard derivative and that of ACh to identify whether it interacts allosterically or orthosterically.

EXPERIMENTAL APPROACH

We incubated the M(1) muscarinic receptor expressed in Chinese hamster ovary cells with ACh mustard for various periods of time in the presence of McN-A-343 or known allosteric and orthosteric ligands. After stopping the reaction and removing unreacted ligands, unalkylated receptors were measured using [(3)H]N-methylscopolamine. Analogous experiments were done using a nitrogen mustard analog of McN-A-343. Affinity constants, cooperativity values for allosteric interactions and rate constants for receptor alkylation were estimated using a mathematical model.

KEY RESULTS

The kinetics of receptor alkylation by the nitrogen mustard derivatives of ACh and McN-A-343 were consistent with a two-step model in which the aziridinium ion rapidly forms a reversible receptor complex, which converts to a covalent complex at a slower rate. The inhibition of receptor alkylation by acetycholine, N-methylscopolamine and McN-A-343 was consistent with competitive inhibition, whereas that caused by gallamine was consistent with allosterism. Affinity constants estimated from alkylation kinetics agreed with those measured by displacement of [(3)H]N-methylscopolamine binding.

CONCLUSIONS AND IMPLICATIONS

Our results suggest that McN-A-343 and its nitrogen mustard derivative interact competitively with ACh and N-methylscopolamine at the orthosteric site on the M(1) muscarinic receptor. Measuring how drugs modulate the kinetics of receptor alkylation by an irreversible ligand is a powerful approach for distinguishing between negative allosteric modulators and competitive inhibitors.

Development of real-time PCR technique for the estimation of population density of Pythium intermedium in forest soils

Pythium intermedium is known to play an important role in the carbon cycling of cool-temperate forest soils. In this study, a fast, precise and effective real-time PCR technique for estimating the population densities of P. intermedium from soils was developed using species-specific primers. Specificity was confirmed both with conventional PCR and real-time PCR. The detection limit (sensitivity) was determined and amplification standard curves were generated using SYBR Green II fluorescent dye. A rapid and accurate assay for quantification of P. intermedium in Takayama forest soils of Japan was developed using a combination of a new DNA extraction method and PCR primers were developed for real-time PCR. And the distribution of P. intermedium in forest soil was investigated with both soil plating method and the developed real-time PCR technique. This new technique will be a useful tool and can be applied to practical use for studying the role of Pythium species in forest and agricultural ecosystems.

Two new species of Pythium, P. senticosum and P. takayamanum,isolated from cool-temperate forest soil in Japan

Pythium senticosum and P. takayamanum spp. nov. were isolated from cool-temperate forest soil in Japan. P. senticosum can grow at 5 C and is fast growing at 25 C with a radial growth of 22.2 mm 24 h(-1). The species is morphologically characterized by ovoid to ellipsoid sporangia with apical papilla, ornamented oogonia with acute conical spines, and antheridia with broad attachment to oogonia. P. takayamanum is very different and can grow at 35 C. This species is morphologically characterized by its wavy antheridial stalks and ellipsoidal oogonia with constricted areas. Phylogenetic analyses of the ITS rDNA region and the partial COX2 gene showed that the two species are genetically distinct from each other and from their closest relatives. P. senticosum is closely related to P. dimorphum and P. undulatum whereas P. takayamanum is closely related to P. rhizosaccharum and P. parvum.

Cellular and molecular features of lipoma tissue: comparison with normal adipose tissue

BACKGROUND

Involvement of adipose-derived stem/progenitor/stromal cells (ASCs) in the development of lipomas has been suggested, but the pathogenesis and pathophysiology of this tumour remain unclear.

OBJECTIVES

To analyse cellular and transcriptional characteristics of lipoma tissue compared with normal adipose tissue, further to delineate differentiating features.

METHODS

For lipoma or normal adipose tissues, we used a new whole-mount staining enabling three-dimensional imaging of nonfixed and nonfrozen adipose tissue. Immunohistochemistry and real-time polymerase chain reaction for obesity-related genes were performed as well as comparative assay of the proliferative and adipogenic capacity of ASCs.

RESULTS

A large number of small adipocytes surrounded by CD34+/lectin- ASCs and increased numbers of Ki67+/CD34+ ASCs indicated enhanced adipogenesis in lipoma compared with normal adipose tissue. In contrast, cellular apoptosis was not enhanced in lipoma, suggesting that the enlargement of lipoma tissue may be due to a positive balance of adipocyte turnover (accelerated adipogenesis combined with nonenhanced apoptosis). Leptin mRNA was upregulated in lipoma, while adiponectin, tumour necrosis factor-alpha and glucose transporter 1 mRNA were downregulated and there were no apparent changes in hypoxia-inducible factor 1alpha, peroxisome proliferator-activated receptor-gamma and plasminogen activator inhibitor-1. These results suggested dysfunction of lipoma adipocytes similar to that in obesity, but indicated that lipoma tissue lacked several obesity-related phenomena such as ischaemia (hypoxia), macrophage infiltration, inflammatory reactions and enhanced glycolysis. ASCs from lipoma and normal adipose tissue showed similar proliferative and adipogenic capacity.

CONCLUSIONS

Our findings revealed that lipoma tissue shows a positive balance of adipocyte turnover involving proliferating ASCs and several transcriptional differences from adipose tissue enlargement in obesity.

Development of microsatellite markers for Pythium helicoides

A strategy combining dual-suppression PCR and thermal asymmetric interlaced PCR was used to determine sequences flanking microsatellite regions in Pythium helicoides. The primer pairs were designed to amplify loci containing (AC)n, (GA)n, (AGC)n, (CAC)n(CAA)n, (TCA)n and (CTTT)n repeats from the P. helicoides nuclear genome. The PCR products of each primer pair, amplified from three representative isolates collected from different hosts and locations, were cloned and sequenced. Different degrees of polymorphism were detected among these microsatellite markers. The numbers of alleles were 6, 2, 4, 11, 4 and 4 in YL-AC, YL-AGC, YL-CAA, YL-CTTT, YL-GA and YL-TCA, respectively. Allele analysis of 30 P. helicoides isolates showed length polymorphisms in all loci, except for YL-AC, using capillary electrophoresis. Thus, we have developed a simple method for designing PCR primers to amplify microsatellite markers from P. helicoides.

Development of simple sequence repeat markers for Japanese isolates of Magnaporthe grisea

We developed nine simple sequence repeat (SSR) markers useful for differentiating Japanese isolates of Magnaporthe grisea through a bioinformatic approach. Repeat sequences in the genome of M. grisea were identified by a Tandem Repeat Finding program. Length polymorphisms at 28 loci were examined, nine of which were selected on the basis of detected polymorphisms. These nine SSR markers showed a Nei's gene diversity ranging from 0.23 to 0.91 among 48 field isolates of two natural populations. These SSR markers are well suited for M. grisea epidemiology and population genetics.

Population Structure of the Fusarium graminearum Species Complex from a Single Japanese Wheat Field Sampled in Two Consecutive Years

The Fusarium graminearum species complex (Fg complex) that consists of at least 11 phylogenetically distinct species contains important Fusarium head blight (FHB) pathogens of wheat and barley worldwide. We obtained members of the Fg complex by sampling from a 500-m² experimental wheat field in Kumamoto Prefecture, Japan in two consecutive years and assessed them for species identity and trichothecene chemotype. Haplotype diversity was estimated by using 11 variable numbers of tandem repeat (VNTR) markers. In addition to these two samples (group 03W in 2003 and group 04W in 2004), pathogen populations from seed that was harvested in Fukuoka Prefecture and planted in the experimental field in 2002 (group 02WSC) and pathogen populations from seed that was harvested in Nagasaki Prefecture and planted in 2003 (group 03WSC) were analyzed for this study. Forty-six isolates were collected in each group. Most isolates from wheat heads were classified as F. asiaticum; only four isolates were classified as F. graminearum sensu stricto (s. str.). Out of a total of 183 Fg complex strains, 80 isolates (44%) were of the NIV type, while 103 isolates (56%), including all four F. graminearum s. str. isolates, were of the 3ADON type. No 15ADON type isolate was detected in this study. Trichothecene chemotype compositions of 03W and 04W were nearly identical. High gene diversity of F. asiaticum was observed in all groups. Based on the observed low level of fixation index (F_ST) and high level of effective number of migrants (Nm), distinctive population subdivision of F. asiaticum was not inferred among the four groups. These results suggest that FHB in the experimental wheat field in both 2003 and 2004 was caused by a genetically similar population, which prevails in Kumamoto, Fukuoka, and Nagasaki prefectures.

Evidence of global chlorophyll d

Although analyses of chlorophyll d (Chl d)-dominated oxygenic photosystems have been conducted since their discovery 12 years ago, Chl d distribution in the environment and quantitative importance for aquatic photosynthesis remain to be investigated. We analyzed the pigment compositions of surface sediments and detected Chl d and its derivatives from diverse aquatic environments. Our data show that the viable habitat for Chl d-producing phototrophs extends across salinities of 0 to 50 practical salinity units and temperatures of 1 degrees to 40 degrees C, suggesting that Chl d production can be ubiquitously observed in aquatic environments that receive near-infrared light. The relative abundances of Chl d derivatives over that of Chl a derivatives in the studied samples are up to 4%, further suggesting that Chl d-based photosynthesis plays a quantitatively important role in the aquatic photosynthesis.

Rapid expansion of human adipose-derived stromal cells preserving multipotency

BACKGROUND

Adipose-derived stromal (stem) cells (ASC) have been shown to be of great therapeutic use in pre-clinical studies in diverse fields, but a standard expansion method has not been established. We investigated the effects of an endothelial growth medium (EGM-2) on ASC, focusing on proliferation and differentiation potentials.

METHODS

ASC were cultured in EGM-2 and DMEM. Doubling time and total cell number were compared between the two media. The proliferative effect of each growth factor supplemented in EGM-2 was also examined. Cultured cells in each medium were examined for surface marker expression using flow cytometry. Differentiation into the adipogenic, chondrogenic and osteogenic lineages was analyzed after culture in each medium.

RESULTS

ASC cultured with EGM-2 proliferated much more rapidly (10(5) times in 2 weeks) and reached the stationary phase earlier than those cultured with DMEM. Among the supplements contained in EGM-2, only fibroblast growth factor-2 (FGF-2) significantly promoted proliferation of ASC, although the proliferative effect of FGF-2 was much less than that of EGM-2, suggesting a synergism among other supplement factors. Flow cytometry and differentiation assays suggested that ASC cultured in EGM-2 preserved immunophenotype and differentiation capacity for at least three mesenchymal lineages (adipogenic, chondrogenic and osteogenic), similar to those cultured with DMEM.

DISCUSSION

The present expansion method markedly accelerates proliferation of ASC, preserving their multipotent differentiation capacities, and lays the groundwork for establishing a practical route to mega-expansion of ASC for clinical applications.

Molecular characterization of the Fusarium graminearum species complex in Japan

Members of the Fusarium graminearum species complex are important cereal pathogens worldwide and belong to one of at least nine phylogenetically distinct species. We examined 298 strains of the F. graminearum species complex collected from wheat or barley in Japan to determine the species and trichothecene chemotype. Phylogenetic analyses and species-diagnostic polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLPs) revealed the presence and differential distribution of F. graminearum sensu stricto (s. str.) and F. asiaticum in Japan. F. graminearum s. str. is predominant in the north, especially in the Hokkaido area, while F. asiaticum is predominant in southern regions. In the Tohoku area, these species co-occurred. Trichothecene chemotyping of all strains by multiplex PCR revealed significantly different chemotype compositions of these species. All 50 strains of F. graminearum s. str. were of a 15- or 3-acetyl deoxynivalenol type, while 173 (70%) out of 246 strains of F. asiaticum were of a nivalenol type. The possibility of gene flow between the two species was investigated by use of 15 PCR-RFLP markers developed in this study. However, no obvious hybrids were detected from 98 strains examined, including strains collected from regions where both species co-occur.

Molecular analysis of the genome segments S1, S4, S6, S7 and S12 of a Rice gall dwarf virus isolate from Thailand; completion of the genomic sequence

The complete nucleotide sequences of the double-stranded RNA segments S1, S4, S6, S7 and S12 of the genome of a Rice gall dwarf virus (RGDV) isolate from Thailand were determined. The segments consisted of 4505, 2622, 1648, 1652 and 853 nucleotides, encoding putative proteins of 1458, 725, 489, 511 and 206 amino acids with molecular masses of approximately 166, 80, 53, 59 and 24 kDa, respectively. Homology searches indicated that each of the putative proteins has a counterpart in isolates of Rice dwarf virus (RDV) and Wound tumor virus, two other species in the genus Phytoreovirus. However, no similarities were found to other registered sequences, including those of other viruses that belong to the family Reoviridae. The identities between homologous structural proteins of RGDV and RDV ranged from 34 to 51% and were thus higher than those between homologous non-structural proteins of RGDV and RDV (16-37%). Among the nonstructural proteins, the highest amino acid sequence identity (37%) was observed for RGDV Pns11 and RDV Pns10, a constituent of tubular inclusions. This observation suggests that a specific amino acid backbone might be required for maintaining not only the three-dimensional structure of virions but also that of inclusions. The entire sequence of the RGDV genome is now available.

Intra-isolate heterogeneity of the ITS region of rDNA in Pythium helicoides

Heterogeneity of the rDNA ITS region in Pythium helicoides and the phylogenetic relationship between P. helicoides and closely related species were investigated. In PCR-RFLP analysis of the rDNA ITS region of six P. helicoides isolates investigated, including the type culture, intraspecific variation was found at the HhaI site. The total length of fragments was longer than before cutting, indicating sequence heterogeneity within isolates. Digestion of the cloned rDNA ITS region derived from seven isolates with HhaI revealed polymorphisms among and within single zoospore isolates, and variability of the region was also present among the clones derived from the same isolate. To test whether the rDNA ITS region of closely related species and other regions in the genome of P. helicoides are also variable, the rDNA ITS region of P. ultimum and the cytochrome oxydase II (cox II) gene encoded in mitochondria were sequenced. P. ultimum had little variation in the rDNA ITS region. The cox II gene sequences of both species revealed only a low intraspecific variability and no intra-isolate variation. In the phylogenic tree based on the rDNA ITS sequences, all clones of P. helicoides formed one large clade that was distinct from the clades comprising morphologically similar species, such as P. oedochilum and P. ostracodes, and was closely related to P. chamaehyphon rather than the other species.

Global molecular surveillance reveals novel Fusarium head blight species and trichothecene toxin diversity

To expand our knowledge of Fusarium head blight (FHB) pathogen and trichothecene toxin diversity, a global collection of 2100 isolates was screened for novel genetic variation, resulting in the identification of 16 phylogenetically divergent FHB isolates. The affinities and taxonomic status of these novel isolates were evaluated via phylogenetic analyses of multilocus DNA sequence data (13 genes; 16.3 kb/strain) together with analyses of their morphology, pathogenicity to wheat, and trichothecene toxin potential. Based on the results of these analyses, we formally describe two novel species (Fusarium vorosii and Fusarium gerlachii) within the Fusarium graminearum species complex (Fg complex), and provide the first published report of Fg complex isolates with either a nivalenol or 3-acetyldeoxynivalenol chemotype within the U.S. In addition, we describe a highly divergent population of F. graminearum from the Gulf Coast of the U.S., and divergent isolates of F. acaciae-mearnsii from Australia and South Africa.

Phylogenetic relationships of Pythium and Phytophthora species based on ITS rDNA, cytochrome oxidase II and beta-tubulin gene sequences

Fifty-eight isolates representing 39 Pythium species and 17 isolates representing nine Phytophthora species were chosen to investigate intra- and intergeneric relationships with sequence analysis of three genomic areas. The internal transcribed spacer regions (ITS1 and ITS2), including the 5.8S gene of the ribosomal DNA were PCR amplified with the universal primers ITS1 and ITS4. On the other hand 563 bp of the cytochrome oxidase II (cox II) gene was amplified with the primer pair FM66 and FM58 for Pythium and FM75 and FM78 for Phytophthora. The 658 bp partial beta-tubulin gene was amplified with the forward primer BT5 and reverse primer BT6. Maximum parsimony analysis of the three DNA regions revealed four major clades, reflective of sporangial morphology. Clade 1 was composed of Pythium isolates that bear filamentous to lobulate sporangia. Clade 2 represents Pythium isolates that bear globose to spherical zoosporangia or spherical hyphal swellings. Meanwhile Phytophthora isolates were lumped into Clade 3 wherein the papillate, semipapillate and nonpapillate species occupied separate subclades. Lastly, Clade 4 was composed of Pythium species that bear subglobose sporangia resembling the papillate sporangia observed in Phytophthora. Hence a number of species (Ph. undulata, P. helicoides, P. ostracodes, P. oedochilum and P. vexans) have been proposed to be the elusive intermediate species in the Pythium-to-Phytophthora evolutionary line.

Lack of alpha2-antiplasmin improves cutaneous wound healing via over-released vascular endothelial growth factor-induced angiogenesis in wound lesions

BACKGROUND

The fibrinolytic system is supposed to play an important role in the degradation of extracellular matrices for physiological and pathological tissue remodeling; however, the detailed mechanism regarding how this system affects cutaneous wound healing remains to be clarified.

METHODS AND RESULTS

We performed experimental cutaneous wounding in mice with a deficiency of alpha(2)-antiplasmin (alpha(2)AP), which is a potent and specific plasmin inhibitor. We found that an accelerated wound closure was observed in alpha(2)AP-deficient (alpha(2)AP-/-) mice in comparison with wild type (WT) mice. Moreover, we observed that a greater increase of angiogenesis occurred in the process of wound healing in alpha(2)AP-/- mice than in the WT mice. Intriguingly, mRNA expression of vascular endothelial growth factor (VEGF), which is the best characterized positive regulator of angiogenesis, in wound lesions was found to show a greater increase in the early phase of the healing process in alpha(2)AP-/- mice than in WT mice. In addition, the amount of released-VEGF from the explanted fibroblasts of alpha(2)AP-/- mice increased dramatically more than in the WT mice. Finally, the intra-jugular administration of anti-VEGF antibody clearly suppressed the increased angiogenesis and accelerated wound closure in the wound lesion of alpha(2)AP-/- mice.

CONCLUSION

The lack of alpha(2)AP markedly causes an over-release of VEGF from the fibroblasts in cutaneous wound lesions, thereby inducing angiogenesis around the area, and thus resulting in an accelerated-wound closure.

CONCLUSIONS

This is the first report to describe the crucial role that alpha(2)AP plays following angiogenesis in the process of wound healing. Our results provide new insight into the role of alpha(2)AP on cutaneous wound healing.

Chromosome complement of the fungal plant pathogen Fusarium graminearum based on genetic and physical mapping and cytological observations

A genetic map of the filamentous fungus Fusarium graminearum (teleomorph: Gibberella zeae) was constructed to both validate and augment the draft whole-genome sequence assembly of strain PH-1. A mapping population was created from a cross between mutants of the sequenced strain (PH-1, NRRL 31084, originally isolated from Michigan) and a field strain from Minnesota (00-676, NRRL 34097). A total of 111 ascospore progeny were analyzed for segregation at 235 loci. Genetic markers consisted of sequence-tagged sites, primarily detected as dCAPS or CAPS (n = 131) and VNTRs (n = 31), in addition to AFLPs (n = 66) and 7 other markers. While most markers exhibited Mendelian inheritance, segregation distortion was observed for 25 predominantly clustered markers. A linkage map was generated using the Kosambi mapping function, using a LOD threshold value of 3.5. Nine linkage groups were detected, covering 1234 cM and anchoring 99.83% of the draft sequence assembly. The nine linkage groups and the 22 anchored scaffolds from the sequence assembly could be assembled into four chromosomes, leaving only five smaller scaffolds (59,630 bp total) of the nuclear DNA unanchored. A chromosome number of four was confirmed by cytological karyotyping. Further analysis of the genetic map data identified variation in recombination rate in different genomic regions that often spanned several hundred kilobases.

Load independence of temperature-dependent Ca2+ recirculation fraction in canine heart

Intramyocardial Ca(2+) recirculation fraction (RF) critically determines the economy of excitation-contraction coupling. RF is obtainable from the exponential decay of the postextrasystolic potentiation of left ventricular (LV) contractility. We have shown that RF remains unchanged despite increasing LV volume (LVV) at normothermia, but decreases with increasing temperature at a constant LVV. However, it remains unknown whether the temperature-dependent RF was not due to the simultaneously changed peak LV pressure (LVP) at a constant LVV. We hypothesized that this temperature-dependent RF would be independent of the simultaneous change in LVP. We used nine excised, cross-circulated canine hearts and allowed their LVs to contract isovolumically. During stable regular beats at 500 msec intervals, we inserted an extrasystolic beat at 360 msec interval followed by the postextrasystolic beats (PESs) at 500 msec intervals. We equalized the temperature-dependent peak LVPs of the regular beats at 36 degrees C and 38 degrees C to the peak LVP level of the stable regular beat at 33 degrees C by adjusting LVV. We fitted the same equation: nEmax = a.exp[-(i - 1)/tau(e)] + b.exp[-(i - 1)/tau(s)]cos[pi(i - 1)] + 1, used before to the normalized Emax (maximum elastance) values of PESi (i = 1-6) relative to the regular beat Emax. RF given by exp(-1/tau(e)) decreased by 19% to 38 degrees C from 33 degrees C. The temperature coefficient (Q(10)) of 1/RF was significantly greater than 1.3. The present results indicated a similar temperature dependence of RF and its Q(10) to those we observed previously without equalizing peak LVP. Thus, the temperature-dependent RF is independent of ventricular loading conditions.