First Report of 'Candidatus Phytoplasma solani' (16SrXII-A) Associated with Fox Nut (Euryale ferox Salisb.) Stolbur Disease in India

Fox nut also known as Gorgon nut, Makhana (Euryale ferox Salisb.) is a high value aquatic crop belonging to the family Nymphaeaceae. In India, it is generally grown in flood prone areas of North Bihar, lower Assam, parts of West Bengal, Odisha, Manipur and Tripura (Jana et al., 2018). India contributes nearly 70-80% of the global fox nut production. During September 2021, a phytoplasma like symptom was noticed on fox nut leaves at Basudeopur Farm of Research Centre for Makhana, Darbhanga, Bihar, India (23° 9' N and 65° 53' E). The characteristic symptom was that some portion of leaf lamina deformed along the veins with wrinkled and raised overgrowth or hypertrophy. The veins were thickened and reddened in the infected leaf area. The infection occurs in petiole as well as in flower stalk. The disease incidence was found as high as 30% which caused severe yield loss which was calculated to be 40% in that particular field. Total of 20 sampled fox nut plants, 10 symptomatic and 10 asymptomatic ones, were collected and tested for the presence of phytoplasma. A nested PCR assay using the phytoplasma universal 16S rRNA primer pairs: P1/P7 followed by R16F2n/R16R2 (J. Jović et al. 2011) amplified the expected ~1.2-kb 16S rDNA fragment in all 10 symptomatic samples. No amplification was detected from asymptomatic samples. One of the ten 1.2-kb nested 16S rDNA PCR products was gel purified, cloned into the pGEM-T-easy plasmid vector (Promega, Madison, WI), and sequenced and was deposited in NCBI under the Accession no.OL873590. BLAST analysis showed that the sequence of the PCR 16S rDNA product was 100% identical to several GenBank sequences of Ca. P. solani (16SrXII Stolbur group) viz. KF907506. Furthermore, analysis by iPhyClassifier software showed that the virtual restriction fragment length polymorphism (RFLP) pattern of the sequenced PCR 16S rDNA product is identical (similarity coefficient 1.00) to the reference pattern of the 16SrXII-A subgroup. Identification of 'Ca. P. solani' was conducted following the STOL11 stolbur-specific protocol (Radonjić et al. 2009). Sequencing of tuf gene (Elongation factor Tu) was performed by using tuf marker genes (Cvrković et al. 2014) from 10 symptomatic and 10 asymptomatic samples. Sequence of the amplified gene (896 bp) was deposited in GenBank under Accession number OM174272. The presence of 'Ca. P. solani' was detected in all symptomatic samples, while all control plants tested negative. The RFLP analysis of tuf gene nested PCR products using HpaII endonuclease (Fermentas) revealed uniform tuf-b type in all positive samples. Nucleotide blast analyses showed that the tuf gene was 100% identical to STOL11 strain of C. P. solani subgroup 16SrXII-A (Accession No JQ797670). For developing a suitable management strategy, identification of the vector is essential. Leaf hoppers visiting the infected plants as well as nearby crop fields will be tested for presence of the phytoplasma. To the best of our knowledge, this is the first report of Candidatus Phytoplasma solani' (16SrXII-A) infecting Fox nut (Euryale ferox Salisb.) in India. References Cvrković et al. 2014. Plant Pathol. 63:42. https://doi.org/10.1111/ppa.12080 Jana, B. R., et al. 2018. Int. J. Curr. Microbiol. App. Sci. 7(12): 578-587. https://doi.org/10.20546/ijcmas.2018.712.072 Jović, J. et al. 2011. B. Insectol. 64:S83. ISI Radonjić, S. et al. 2009. J. Phytopathol. 157:682. https://doi.org/10.1111/j.1439- 0434.2009.01560.

Whole Genome Sequencing Shows Genetic Diversity, as Well as Clonal Complex and Gene Polymorphisms Associated with Fluconazole Non-Susceptible Isolates of Candida tropicalis

Resistance to azoles in Candida tropicalis is increasing and may be mediated by genetic characteristics. Using whole genome sequencing (WGS), we examined the genetic diversity of 82 bloodstream C. tropicalis isolates from two countries and one ATCC strain in a global context. Multilocus sequence typing (MLST) and single nucleotide polymorphism (SNP)-based phylogenies were generated. Minimum inhibitory concentrations (MIC) for antifungal agents were determined using Sensititre YeastOne YO10. Eleven (13.2%) isolates were fluconazole-resistant and 17 (20.5%) were classified as fluconazole-non susceptible (FNS). Together with four Canadian isolates, the genomes of 12 fluconazole-resistant (18 FNS) and 69 fluconazole-susceptible strains were examined for gene mutations associated with drug resistance. Fluconazole-resistant isolates contained a mean of 56 non-synonymous SNPs per isolate in contrast to 36 SNPs in fluconazole-susceptible isolates (interquartile range [IQR] 46−59 vs. 31−48 respectively; p < 0.001). Ten of 18 FNS isolates contained missense ERG11 mutations (amino acid substitutions S154F, Y132F, Y257H). Two echinocandin-non susceptible isolates had homozygous FKS1 mutations (S30P). MLST identified high genetic diversity with 61 diploid sequence types (DSTs), including 53 new DSTs. All four isolates in DST 773 were fluconazole-resistant within clonal complex 2. WGS showed high genetic variation in invasive C. tropicalis; azole resistance was distributed across different lineages but with DST 773 associated with in vitro fluconazole resistance.

Genetic Heterogeneity of Australian Candida auris Isolates: Insights From a Nonoutbreak Setting Using Whole-Genome Sequencing

Whole-genome sequencing clustered Australian Candida auris isolates from sporadic cases within clade III. Case isolates were genomically distinct; however, unexpectedly, those from 1 case comprised 2 groups separated by >60 single nucleotide polymorphisms (SNPs) with no isolate being identical, in contrast to outbreaks where isolates from any 1 individual have differed by <3 SNPs. Multidrug resistance was absent. High within-host genetic heterogeneity should be considered when investigating C. auris infections.

Surveillance for azole resistance in clinical and environmental isolates of Aspergillus fumigatus in Australia and cyp51A homology modelling of azole-resistant isolates

Background

The prevalence of azole resistance in Aspergillus fumigatus is uncertain in Australia. Azole exposure may select for resistance. We investigated the frequency of azole resistance in a large number of clinical and environmental isolates.

Methods

A. fumigatus isolates [148 human, 21 animal and 185 environmental strains from air (n = 6) and azole-exposed (n = 64) or azole-naive (n = 115) environments] were screened for azole resistance using the VIPcheck™ system. MICs were determined using the Sensititre™ YeastOne YO10 assay. Sequencing of the Aspergillus cyp51A gene and promoter region was performed for azole-resistant isolates, and cyp51A homology protein modelling undertaken.

Results

Non-WT MICs/MICs at the epidemiological cut-off value of one or more azoles were observed for 3/148 (2%) human isolates but not amongst animal, or environmental, isolates. All three isolates grew on at least one azole-supplemented well based on VIPcheck™ screening. For isolates 9 and 32, the itraconazole and posaconazole MICs were 1 mg/L (voriconazole MICs 0.12 mg/L); isolate 129 had itraconazole, posaconazole and voriconazole MICs of >16, 1 and 8 mg/L, respectively. Soil isolates from azole-exposed and azole-naive environments had similar geometric mean MICs of itraconazole, posaconazole and voriconazole (P > 0.05). A G54R mutation was identified in the isolates exhibiting itraconazole and posaconazole resistance, and the TR34/L98H mutation in the pan-azole-resistant isolate. cyp51A modelling predicted that the G54R mutation would prevent binding of itraconazole and posaconazole to the haem complex.

Conclusions

Azole resistance is uncommon in Australian clinical and environmental A. fumigatus isolates; further surveillance is indicated.

Multidrug-Resistant Salmonella enterica 4,[5],12:i:- Sequence Type 34, New South Wales, Australia, 2016-2017

Multidrug- and colistin-resistant Salmonella enterica serotype 4,[5],12:i:- sequence type 34 is present in Europe and Asia. Using genomic surveillance, we determined that this sequence type is also endemic to Australia. Our findings highlight the public health benefits of genome sequencing–guided surveillance for monitoring the spread of multidrug-resistant mobile genes and isolates.

In vitro activity of the novel antifungal compound F901318 against Australian Scedosporium and Lomentospora fungi

We determined the in vitro activity of the novel orotomide antifungal, F901318, against 30 Lomentospora prolificans, 20 Scedosporium apiospermum, 7 S. aurantiacum, and 3 S. boydii, isolates in comparison with standard antifungals. Against L. prolificans, F901318 was the most potent compound (MIC90 0.25 μg/ml); the geometric mean MIC (0.26 μg/ml) was significantly lower (23-80-fold) than those of itraconazole, voriconazole, posaconazole, and isavuconazole (all P < .001), and amphotericin B (P < .05). F901318 also had good activity against S. apiospermum, S. aurantiacum, and S. boydii, comparable to that of voriconazole and posaconazole but was more active than isavuconazole for all three species.

Work Ability among Nurses in a Public Medical College Hospital

This cross sectional study was carried out 197 nurses of Shaheed Suhrawardy Medical College Hospital (ShSMCH), Dhaka, Bangladesh from 1st July 2015 to 30th June 2016. Purpose of the study was to assess work ability and its association with sociodemographic characteristics & work related variables which affect work ability among nurses in a Public Medical College Hospital. Sampling method was simple random sampling. By face to face interview data was collected with the help of semi-structured questionnaire and all data were analyzed with SPSS software version 21. For descriptive statistics means, SD and range were calculated as required. Data were presented in frequency table, pie diagram. Statistical test chi-square was used and p<0.05 was consider to be statistically significant. It was found that 136(69%) respondents were between the age of 21 to 39 years and mean age was 35.95 Years, 187(94.9%) were female, 156(79.2%) were Muslim, 166(84.3%) had Diploma, 180(91.4%) family income were equal to and more than 40,000 Tk. 189(95.5%) had done clinical work; 49(24.9%) worked at medicine. Majority 183(92.9%) respondents had good to excellent work ability and 14(7.1%) had less good work ability. In this study significant association (p<0.05) was found between work ability and gender, educational status and type of job. This research provides an initial step in understanding the work ability of nurses in a Public Medical College Hospital. The present study showed that nurses' work ability is at the good to excellent level. This study also reveals significant association between work ability and gender, educational status and type of job.

Whole Genome Sequencing of Australian Candida glabrata Isolates Reveals Genetic Diversity and Novel Sequence Types

Candida glabrata is a pathogen with reduced susceptibility to azoles and echinocandins. Analysis by traditional multilocus sequence typing (MLST) has recognized an increasing number of sequence types (STs), which vary with geography. Little is known about STs of C. glabrata in Australia. Here, we utilized whole genome sequencing (WGS) to study the genetic diversity of 51 Australian C. glabrata isolates and sought associations between STs over two time periods (2002-2004, 2010-2017), and with susceptibility to fluconazole by principal component analysis (PCA). Antifungal susceptibility was determined using Sensititre YeastOne^TM Y010 methodology and WGS performed on the NextSeq 500 platform (Illumina) with in silico MLST STs inferred by WGS data. Single nucleotide polymorphisms (SNPs) in genes linked to echinocandin, azole and 5-fluorocytosine resistance were analyzed. Of 51 isolates, WGS identified 18 distinct STs including four novel STs (ST123, ST124, ST126, and ST127). Four STs accounted for 49% of isolates (ST3, 15.7%; ST83, 13.7%; ST7, 9.8%; ST26, 9.8%). Split-tree network analysis resolved isolates to terminal branches; many of these comprised multiple isolates from disparate geographic settings but four branches contained Australian isolates only. ST3 isolates were common in Europe, United States and now Australia, whilst ST8 and ST19, relatively frequent in the United States, were rare/absent amongst our isolates. There was no association between ST distribution (genomic similarity) and the two time periods or with fluconazole susceptibility. WGS identified mutations in the FKS1 (S629P) and FKS2 (S663P) genes in three, and one, echinocandin-resistant isolate(s), respectively. Both mutations confer phenotypic drug resistance. Twenty-five percent (13/51) of isolates were fluconazole-resistant (MIC ≥ 64 μg/ml) of which 9 (18%) had non wild-type MICs to voriconazole and posaconazole. Multiple SNPs were present in genes linked to azole resistance such as CgPDR1 and CgCDR1, as well as several in MSH2; however, SNPs occurred in both azole-susceptible and azole-resistant isolates. Although no particular SNP in these genes was definitively associated with resistance, azole-resistant/non-wild type isolates had a propensity to harbor SNPs resulting in amino acid substitutions in Pdr1 beyond the first 250 amino acid positions. The presence of SNPs may be markers of STs. Our study shows the value of WGS for high-resolution sequence typing of C. glabrata, discovery of novel STs and potential to monitor trends in genetic diversity. WGS assessment for echinocandin resistance augments phenotypic susceptibility testing.

Whole Genome Sequencing of Candida glabrata for Detection of Markers of Antifungal Drug Resistance

Candida glabrata can rapidly acquire mutations that result in drug resistance, especially to azoles and echinocandins. Identification of genetic mutations is essential, as resistance detected in vitro can often be correlated with clinical failure. We examined the feasibility of using whole genome sequencing (WGS) for genome-wide analysis of antifungal drug resistance in C. glabrata. The aim was torecognize enablers and barriers in the implementation WGS and measure its effectiveness. This paper outlines the key quality control checkpoints and essential components of WGS methodology to investigate genetic markers associated with reduced susceptibility to antifungal agents. It also estimates the accuracy of data analysis and turn-around-time of testing. Phenotypic susceptibility of 12 clinical, and one ATCC strain of C. glabrata was determined through antifungal susceptibility testing. These included three isolate pairs, from three patients, that developed rise in drug minimum inhibitory concentrations. In two pairs, the second isolate of each pair developed resistance to echinocandins. The second isolate of the third pair developed resistance to 5-flucytosine. The remaining comprised of susceptible and azole resistant isolates. Single nucleotide polymorphisms (SNPs) in genes linked to echinocandin, azole and 5-flucytosine resistance were confirmed in resistant isolates through WGS using the next generation sequencing. Non-synonymous SNPs in antifungal resistance genes such as FKS1, FKS2, CgPDR1, CgCDR1 and FCY2 were identified. Overall, an average of 98% of the WGS reads of C. glabrata isolates mapped to the reference genome with about 75-fold read depth coverage. The turnaround time and cost were comparable to Sanger sequencing. In conclusion, WGS of C. glabrata was feasible in revealing clinically significant gene mutations involved in resistance to different antifungal drug classes without the need for multiple PCR/DNA sequencing reactions. This represents a positive step towards establishing WGS capability in the clinical laboratory for simultaneous detection of antifungal resistance conferring substitutions.

Identification of genetic markers of resistance to echinocandins, azoles and 5-fluorocytosine in Candida glabrata by next-generation sequencing: a feasibility study

OBJECTIVES

Multi-antifungal drug resistance in Candida glabrata is increasing. We examined the feasibility of next-generation sequencing (NGS) to investigate the presence of antifungal drug resistance markers in C. glabrata.

METHODS

The antifungal susceptibility of 12 clinical isolates and one ATCC strain of C. glabrata was determined using the Sensititre YeastOne^® YO10 assay. These included three isolate pairs where the second isolate of each pair had developed a rise in drug MICs. Single nucleotide polymorphisms (SNPs) in genes known to be linked to echinocandin, azole and 5-fluorocytosine resistance were analysed in all isolates through NGS.

RESULTS

High-quality non-synonymous SNPs in antifungal resistance genes such as FKS1, FKS2, CgCDR1, CgPDR1 and FCY2 were identified. For two of three isolate pairs, there was a >60-fold rise in MICs to all echinocandins in the second isolate from each pair; one echinocandin-resistant isolate harboured a mutation in FKS1 (S629P) and the other in FKS2 (S663P). Of the third pair, both the 5-fluorocytosine-susceptible, and resistant isolates had a mutation in FCY2 (A237T). SNPs in CgPDR1 were found in pan-azole-resistant isolates. SNPs in other genes linked to azole resistance (CgCDR1, ERG9 and CgFLR1) were present in both azole-susceptible and azole-resistant isolates. SNPs were also identified in Candida adhesin genes EPA1, EPA6, PWP2 and PWP5 but their presence was not associated with higher drug MICs.

CONCLUSIONS

Genome-wide analysis of antifungal resistance markers was feasible and simultaneously revealed mutation patterns of genes implicated in resistance to different antifungal drug classes.

Successful treatment of cutaneous protothecosis with liposomal amphotericin and oral itraconazole

Protothecosis is a rare algal infection, affecting primarily immunocompromised hosts. Optimal management is unclear: in-vitro antimicrobial breakpoints are not established and therapeutic decisions are primarily based on case reports. We present a case of cutaneous Prototheca wickerhamii infection in an immunosuppressed 63 year old male, successfully treated with liposomal amphotericin and prolonged itraconazole. Inoculation may have been through frequent hot-tub use, highlighting hot-tub exposure as an infection risk for the immunocompromised host.

First Report of Potato leaf roll virus (PLRV) Naturally Occurring on Jute (Corchorus olitorius) in India

Jute (Corchorus olitorius L.) is an important bast fiber crop that is mainly grown in the Southeast Asian countries like India, Bangladesh, Nepal, China, Indonesia, Thailand, Myanmar, and a few South American countries. In June 2013, symptoms suggestive of a viral disease were noticed on jute (cv. JRO524) in an experimental field of the CRIJAF research farm, Barrackpore, India, and the incidence of the disease was less than 2%. The infected plants showed stunted growth and short height. Mostly the upper leaves elongated with curling and coiling of lamina. Puckering and shoe string effect were also noticed. Petioles and stipules of the affected leaves were exceptionally longer. Although initially the incidence was low, it may spread to larger areas in subsequent years. Because the jute fiber is extracted from the stem, stunted growth and short height would badly affect the fiber yield and quality. Ten symptomatic and ten asymptomatic healthy looking samples were collected from the field. Corchorus golden mosaic begomovirus is common in jute; therefore, all the samples were tested by PCR using JMFL-AF/JMFL-AR, DNA-A component specific primer pair and JMFL-BF/JMFL-BR, DNA-B component specific primer pairs (1). However, there was no amplification. Because the aphid Aphis gossypii was often noticed in the jute field, all the samples were tested by double-antibody sandwich (DAS)-ELISA for common aphid transmitted viruses, e.g., Cucumber mosaic virus, Bean common mosaic virus, Cowpea mosaic virus, Papaya ring spot virus, Potato leaf roll virus (PLRV), Potato virus Y, and Watermelon mosaic virus using commercial diagnostic kits (Agdia). The symptomatic samples showed positive reaction only for PLRV. Five ELISA-positive samples and five asymptomatic healthy samples were used for RNA extraction. Total RNA was extracted by using QIAGEN RNeasy mini kit. RT-PCR was carried out with PLRV CP gene specific primer pair (3) which generated a cDNA amplicon of 627 bp in all ELISA-positive symptomatic samples. PLRV was not detected in symptomless samples. The five purified cDNA products were cloned in a pGEM-T Easy vector (Promega) and were sequenced. One of the five identical sequences was deposited in GenBank (Accession No. KF233880). The consensus sequence was analyzed by NCBI BLAST and found to share 99% similarity with the coat protein sequence of PLRV reference strain (S77421). Nucleotide span and ORF finder (NCBI) analysis indicated the 627-bp PCR amplicon coded part of a coat protein gene that had 100% identity with translated gene product (Protein ID AAB33483). PLRV is a small isometric RNA virus with worldwide distribution belonging to the family Luteoviridae whose natural host range is mainly restricted to solanaceous plants and few plants of other families (2,4). To the best of our knowledge, this is the first report of PLRV naturally occurring on jute (C. olitorius). References: (1) R. Ghosh et al. J. Virol. Methods 159:34, 2009. (2) S. Guyader and D. G. Ducray. J. Gen. Virol. 83:1799, 2002. (3) M. A. Mayo et al. J. Gen. Virol. 70:1037, 1989. (4) K. Mukherjee et al. Virus Genes 26:247, 2003.

First Report of a 16Sr I-B Phytoplasma Associated with Phyllody and Stem Fasciation of Flax (Linum usitatissimum) in India

Flax or linseed is grown as a fiber or oilseed crop in tropical and temperate regions. It is commercially cultivated in many countries of the world including Canada, China, India, the United States, Ethiopia, Pakistan, Russia, Poland, and Argentina (1). In December 2013, symptoms suggestive of phytoplasma infection were noticed on flax in different experimental fields of Central Research Institute for Jute and Allied Fibres (CRIJAF) research farm, Barrackpore, India, and the incidence was less than 2%. Because incidence of phytoplasma diseases are increasing worldwide, occurrence of a phytoplasma in a new geographical area poses an imminent threat. The infected plants showed floral virescence, phyllody, and stem fasciation (flattened stem). Floral malformation was very conspicuous with abnormal structures replacing normal flowers. All the floral parts, including petals, turned into green leaves. Total DNA was extracted from leaf mid veins of three symptomatic and three asymptomatic plants using a DNeasy Plant Mini Kit (Qiagen). PCR was carried out with the phytoplasma-specific universal P1/P7 primer set followed by nested primer pair R16F2n/R16R2 (2), resulting in DNA amplicons that were 1.8 kb and 1.2 kb, respectively, in all symptomatic samples tested. No amplification was observed with DNA from symptomless samples. This suggested association of a phytoplasma with the disease. The five purified nested PCR products were cloned in a pGEM-T Easy vector (Promega) and sequenced. One of the sequences that proved to be identical to the others was deposited in GenBank (Accession No. KJ417660). The consensus sequence was analyzed by NCBI BLAST and found to share 99% similarity with the 16Sr DNA sequence of the 'Candidatus Phytoplasma asteris' reference strain (GenBank HQ828108), which belongs to 16SrI group. The phylogenetic tree based on 16SrDNA sequence of phytoplasmas belonging to group 16SrI and other distinct phytoplasma groups also showed that the phytoplasma clustered with members of group 16SrI (3). The nested PCR product of R16F2n/R16R2 was digested using restriction enzymes AluI, BfaI, BstU, HhaI, HpaI, KpnI, MseI, and RsaI. The RFLP patterns were compared with those of known phytoplasma strains (2) and they matched the patterns for aster yellows subgroup B (16Sr I-B). Subsequently, the iPhyClassifier 16Sr group/subgroup classification based on similarity (4) analyses showed that the studied strain had 16SrDNA sequences in the 16SrI-B group with a similarity coefficient of 1.00. To the best of our knowledge, this is the first report of 16SrI-B phytoplasma associated with flax in India. References: (1) K. P. Akhtar et al. Phytoparasitica 41:383, 2013. (2) I. M. Lee et al. Int. J. Syst. Evol. Microbiol. 54:337, 2004. (3) N. Saitou and M. Nei. Mol. Biol. Evol. 4:406, 1987. (4) Y. Zhao et al. Int. J. Syst. Evol. Microbiol. 59:2582, 2009.

Functional disruption of yeast metacaspase, Mca1, leads to miltefosine resistance and inability to mediate miltefosine-induced apoptotic effects

Miltefosine (MI) is a novel, potential antifungal agent with activity against some yeast and filamentous fungal pathogens. We previously demonstrated in the model yeast, Saccharomyces cerevisiae, that MI causes disruption of mitochondrial membrane potential and apoptosis-like cell death via interaction with the Cox9p sub-unit of cytochrome c oxidase (COX). To identify additional mechanisms of antifungal action, MI resistance was induced in S. cerevisiae by exposure to the mutagen, ethyl methanesulfonate, and gene mutation(s) responsible for resistance were investigated. An MI-resistant haploid strain (H-C101) was created. Resistance was retained in the diploid strain (D-C101) following mating, confirming dominant inheritance. Phenotypic assessment of individual D-C101 tetrads revealed that only one mutant gene contributed to the MI-resistance phenotype. To identify this gene, the genome of H-C101 was sequenced and 17 mutated genes, including metacaspase-encoding MCA1, were identified. The MCA1 mutation resulted in substitution of asparagine (N) with aspartic acid (D) at position 164 (MCA1(N164D)). MI resistance was found to be primarily due to MCA1(N164D), as single-copy episomal expression of MCA1(N164D), but not two other mutated genes (FAS1(T1417I) and BCK2(T104A)), resulted in MI resistance in the wild-type strain. Furthermore, an MCA1 deletion mutant (mca1Δ) was MI-resistant. MI treatment led to accumulation of reactive oxygen species (ROS) in MI-resistant (MCA1(N164D)-expressing and mca1Δ) strains and MI-susceptible (MCA1-expressing) strains, but failed to activate Mca1 in the MI-resistant strains, demonstrating that ROS accumulation does not contribute to the fungicidal effect of MI. In conclusion, functional disruption of Mca1, leads to MI resistance and inability to mediate MI-induced apoptotic effects. Mca1-mediated apoptosis is therefore a major mechanism of MI-induced antifungal action.

First Report of a 16SrV-C Phytoplasma Causing Little Leaf and Bunchy Top of Tossa Jute (Corchorus olitorius) in India

Jute is the most important phloem fiber crop of the world, and is mainly grown in the South East Asian countries of India, Bangladesh, Nepal, China, Indonesia, Thailand, and Myanmar, and few South American countries. The fiber is used in making sacks, ropes, bags, carpets, shoes, geo-textiles, and home decorations. There are two kinds of jute: tossa jute (Corchorus olitorius L.) and white jute (C. capsularis). In June 2012, symptoms suggestive of phytoplasma infection (little leaf and bunchy top) were noticed on tossa jute in different experimental fields of the CRIJAF research farm, Barrackpore, India, and the incidence of the disease varied from 5 to 20%. The infected plants showed profuse lateral branching with a bushy appearance. In many plants, branching at the apical portion developed a bunchy top symptom with tufts of smaller leaves. Leafy stem was also common in many plants with main stems covered with numerous little leaves. Total DNA was extracted from leaf midveins of 15 symptomatic and 5 asymptomatic plants by using an improved salt concentration and simple sodium acetate CTAB method (1). PCR was carried out with universal P1/P7 primer set followed by nested primer pair R16F2n/R16R2 (3), resulting in DNA amplicons that were 1.8 kb and 1.2 kb, respectively, in all symptomatic samples tested. Phytoplasma was not detected in symptomless samples. The five purified nested products were cloned in a pGEM-T Easy vector (Promega) and sequenced. One of the sequences that proved to be identical was deposited in GenBank (Accession No. KF501045). The consensus sequence was analyzed by NCBI BLAST and found to share 99% similarity with the 16Sr DNA sequence of the alder yellows phytoplasma reference strain (GenBank Accession No. AY028789), which belongs to the 16SrV group. The phylogenetic tree based on the 16SrDNA sequence of phytoplasmas belonging to group 16SrV and other distinct phytoplasma groups also showed that the phytoplasma clustered with members of subgroup 16SrV (4). Subsequently, in silico RFLP analysis of the nested PCR product with the pDRAW32 program using AluI and TruI restriction site used for 16SrV subgroups A, B, C, D, and E indicated that the 16SrV Corchorus strain belonged to subgroup C. RFLP patterns from all symptomatic C. olitorius samples were identical to the 16SrV-C pattern (2). The vector species transmitting the concerned phytoplasma in C. olitorius still needs to be identified. The leaf hopper, Amrasca biguttula biguttula, may be a potential vector as it is often noticed in jute fields. To the best of our knowledge, this is the first report of 16SrV-C phytoplasma associated with tossa jute (C. olitorius) in India. Initiative has to be taken to manage this disease; otherwise, branching of the main stems would badly affect the fiber quality as well as yield. References: (1) C. Biswas et al. Lett. Appl. Microbiol. 56:105, 2012. (2) B. Duduk et al. J. Phytopathology 152:575, 2004. (3) I. M. Lee et al. Int. J. Syst. Evol. Microbiol. 54:337, 2004. (4) N. Saitou and M. Nei. Mol. Biol. Evol. 4:406, 1987.

First Report of Bacterial Leaf Spot Caused by Xanthomonas campestris pv. olitorii on Jute Grown for Seed in India

Jute (Corchorus olitorius L.) is the second most important fiber crop after cotton in terms of global production (3). In November 2011, symptoms suggestive of bacterial infection were observed on a seed crop of jute at the CRIJAF research farm, Barrackpore, West Bengal, India. The disease appeared as small, brown, circular spots, usually less than 5 mm in diameter on the leaves and some of the spots were surrounded by a yellow halo. The lesions on the stems were elongated and in some cases were found to girdle the stem. In the later stages of disease, brown sunken spots were found on the green capsules. Disease incidence varied from about 20% to 90% of the total plants in different affected fields at the CRIJAF research farm. Bacterial leaf spot of jute with similar symptoms was reported in 1957 from Sudan (4). Five symptomatic and three asymptomatic leaf samples were collected from different jute fields. Bacterial colonies isolated on nutrient agar medium from infected young leaves were Xanthomonas-like and pale yellow cream in color. Total DNA was extracted from symptomatic as well as asymptomatic leaf samples by using an improved salt concentration and simple sodium acetate CTAB method (2). Single bacterial colonies were transferred to nutrient agar (NA) medium plates and incubated at 28°C for 48 h. Pure colonies from plates were used directly for DNA extraction using the QIAGEN DNeasy Blood and Tissue kit. PCR was carried out with Xanthomonas campestris specific primers NZ8F3/NZ85R3 (1), which generated an amplicon of 530 bp from all the symptomatic leaf samples as well as pure cultures of the isolated bacteria. No amplification was obtained from asymptomatic leaves. The amplicons from the five symptomatic samples collected from the field were sequenced and showed 100% identity with one another, and one sequence (strain JB-CO-13) was deposited in GenBank (Accession No. KC342185). The BLASTn analysis revealed that bacterial strain JB-CO-13 had 100% identity with X. campestris pv. olitorii (EU285213). Nucleotide span and ORF finder (NCBI) analysis indicated the 530-bp PCR amplicon coded part of a gyrase B gene that had 100% identity with a translated gene product (Protein ID: ABX84334). Three leaves of five 1-month-old jute plants (cv. JRO 204) in pot culture were infiltrated each with a separate bacterial strain using suspensions (1 × 10⁵ CFU/ml) in distilled water. The negative control consisted of leaves infiltrated with sterile distilled water. The plants were kept in a greenhouse with mean maximum and minimum temperatures of 28.96 and 21.8°C, respectively. The plants were covered with plastic bags to maintain high relative humidity (>80%). Typical bacterial lesions were recorded on all the inoculated plants after 1 week. No lesions were seen on the negative control. To the best of our knowledge, this is the first report of bacterial leaf spot on C. olitorius caused by X. campestris pv. olitorii from India. References: (1) J. Adriko et al. Plant Pathol. 61:489, 2012. (2) C. Biswas, et al. Lett. Appl. Microbiol. 56:105, 2013. (3) Food and Agriculture Organization of the United Nations. Agricultural Commodities: Profiles and Relevant WTO Negotiating Issues. Online: http://www.fao.org/docrep/006/Y4343E/y4343e03.htm , 2003. (4) K. A. Sabet. Ann. Appl. Biol. 45:516, 1957.

A multiplex nested PCR assay for simultaneous detection of Corchorus golden mosaic virus and a phytoplasma in white jute (Corchorus capsularis L.)

A multiplex nested PCR assay was developed by optimizing reaction components and reaction cycling parameters for simultaneous detection of Corchorus golden mosaic virus (CoGMV) and a phytoplasma (Group 16Sr V-C) causing little leaf and bunchy top in white jute (Corchorus capsularis). Three sets of specific primers viz. a CoGMV specific (DNA-A region) primer, a 16S rDNA universal primer pair P1/P7 and nested primer pair R16F2n/R2 for phytoplasmas were used. The concentrations of the PCR components such as primers, MgCl2 , Taq DNA polymerase, dNTPs and PCR conditions including annealing temperature and amplification cycles were examined and optimized. Expected fragments of 1 kb (CoGMV), 674 bp (phytoplasma) and 370 bp (nested R16F2n/R2) were successfully amplified by this multiplex nested PCR system ensuring simultaneous, sensitive and specific detection of the phytoplasma and the virus. The multiplex nested PCR provides a sensitive, rapid and low-cost method for simultaneous detection of jute little leaf phytoplasma and CoGMV. Based on BLASTn analyses, the phytoplasma was found to belong to the Group 16Sr V-C.

A simple method of DNA isolation from jute (Corchorus olitorius) seed suitable for PCR-based detection of the pathogen Macrophomina phaseolina (Tassi) Goid

A simple method was developed for isolating DNA from jute seed, which contains high amounts of mucilage and secondary metabolites, and a PCR protocol was standardized for detecting the seedborne pathogen Macrophomina phaseolina. The cetyl trimethyl ammonium bromide method was modified with increased salt concentration and a simple sodium acetate treatment to extract genomic as well as fungal DNA directly from infected jute seed. The Miniprep was evaluated along with five other methods of DNA isolation in terms of yield and quality of DNA and number of PCR positive samples. The Miniprep consistently recovered high amounts of DNA with good spectral qualities at A260/A280. The DNA isolated from jute seed was found suitable for PCR amplification. Macrophomina phaseolina could be detected by PCR from artificially inoculated as well as naturally infected jute seeds. The limit of PCR-based detection of M. phaseolina in jute seed was determined to be 0·62 × 10(-7) CFU g(-1) seed.

Electronic and magnetic properties of quasifreestanding graphene on Ni

For the purpose of recovering the intriguing electronic properties of freestanding graphene at a solid surface, graphene self-organized on a Au monolayer on Ni(111) is prepared and characterized by scanning tunneling microscopy. Angle-resolved photoemission reveals a gapless linear pi-band dispersion near K[over] as a fingerprint of strictly monolayer graphene and a Dirac crossing energy equal to the Fermi energy (EF) within 25 meV meaning charge neutrality. Spin resolution shows a Rashba effect on the pi states with a large (approximately 13 meV) spin-orbit splitting up to EF which is independent of k.

The role and regulation of tumour-associated hyaluronan

Significantly increased levels of the glycosaminoglycan hyaluronan are often associated with human and animal tumours. In the rabbit V2 carcinoma elevated levels of tumour-associated hyaluronan are also closely correlated with invasiveness. We have therefore initiated studies to better define the role and regulation of hyaluronan synthesis in tumour tissues. In cell culture many tumour cell types have reduced capacities to synthesize hyaluronan even when derived from tumours enriched in hyaluronan. We showed that several of these same cells can nevertheless stimulate hyaluronan synthesis by normal fibroblasts. In the LX-1 human lung carcinoma cell line this stimulatory potential resides in a membrane-bound, heat-sensitive, lipophilic, cell surface glycoprotein. These data suggest that production of tumour-associated hyaluronan occurs via tumour-stromal cell interactions. We recently demonstrated that some human tumour cells also possess unoccupied, high affinity, cell surface binding sites for hyaluronan which may allow tumour cells to interact directly with hyaluronan-enriched extracellular matrices. This interaction may in turn allow tumour cells to use hyaluronan as a support for adhesion and locomotion. The spatial organization of hyaluronan could then function to guide tumour cells into surrounding stroma. We attempted to visualize this spatial deposition of hyaluronan in situ within frozen sections of human tumour tissue using a morphological probe that specifically recognizes hyaluronan. Hyaluronan appears most prominently in the partially degraded connective tissue.

Argon nanobubbles in Al(111): a photoemission study

Two fundamental manifestations of Al conduction electron response to Ar atom core hole in the final state of photoemission have been studied in implanted Ar bubbles in Al(111). Ar 2p binding energy and the Doniach-Sunjić asymmetry of the core-level line shape vary systematically as functions of Ar+ implantation energy and number of ions bombarded (fluence). The observations are explained by relating the strength of Al conduction electron screening to the size of the Ar nanobubbles.

Threshold retinopathy of prematurity: ocular changes and sequelae following cryotherapy

PURPOSE

To determine ocular changes and sequelae following cryotherapy for threshold retinopathy of prematurity (ROP).

METHODS

This is a retrospective study of 49 eyes of 26 premature babies with threshold ROP treated with cryotherapy between 1995 and 1998. All eyes included in the study had favourable structural outcome after cryotherapy. Follow-up examination of all babies was done 12 - 62 months (average 28 months) after cryotherapy. Visual axis, fixation pattern, anterior segment examination, cycloplegic refraction and dilated fundus examination with indirect ophthalmoscopy were undertaken in all eyes during follow-up.

RESULTS

Posterior pole retinal residuae observed following cryotherapy were tortousity of blood vessels in 32 (65.3%), narrow temporal arcade in 22 (44.89%), temporal crescent in 17 (34.69%), disc drag in 13 (26.53%) and macular heterotopia in 7 (14.28%) eyes. Myopia was observed in 20 (40.82%) eyes and strabismus in 5 (19.23%) babies. The significant risk factor for ocular changes was ROP with more clock hours of involvement (p < 0.05). Higher period of gestation was associated with posterior pole changes (p< 0.05).

CONCLUSIONS

All premature babies with threshold ROP treated with cryotherapy require frequent and long-term follow up to look for retinal residuae, refractive status, and ocular motility disorders.

Investigation on interaction of Achatinin, a 9-O-acetyl sialic acid-binding lectin, with lipopolysaccharide in the innate immunity of Achatina fulica snails

Achatinin, a 9-O-acetyl sialic acid (9-O-AcSA) binding lectin, has been demonstrated to be synthesized in amoebocytes of Achatina fulica snails. This lectin was affinity-purified from Achatina amoebocytes lysate (AAL); it appeared as a single band on native polyacrylamide gel electrophoresis (PAGE) and showed 16 identical subunits of M.W. 15 kDa on sodium dodecyl sulphate (SDS)-PAGE. It was found to be homologous with an earlier reported lectin, Achatinin-H, derived from hemolymph of A. fulica snails (Sen, G., Mandal, C., 1995. The specificity of the binding site of Achatinin-H, a sialic-acid binding lectin from Achantia fulica. Carbohydr. Res., 268, 115-125). Homology between both lectins was confirmed by their similar electrophoretic mobilities, carbohydrate specificity and cross reactivity on immunodiffusion. Achatinin showed in vitro calcium dependent binding to two 9-O-acetylated sialoglyoconjugates (9-O-AcSG) on lipopolysaccharide (LPS) (Escherichia coli 055: B5) of M.W. 40 kDa and 27.5 kDa, which was abolished following de-O-acetylation. Based on the previously defined narrow sugar specificity of Achatinin towards 9-O-AcSAalpha2-->6GalNAc [Sen, G., Mandal, C., 1995. The specificity of the binding site of Achatinin-H, a sialic-acid binding lectin from Achatina fulica. Carbohydr. Res., 268, 115-125], we conclude that LPS contains this lectinogenic epitope at the terminal sugar moiety. The Achatinin-mediated hemagglutination inhibition of rabbit erythrocytes by LPS further confirmed it. The lectin exhibited bacteriostatic effect on Gram-negative bacteria E. coli, DH5alpha and C600. AAL was earlier reported to undergo coagulation in presence of pg level of LPS (Biswas, C., Mandal, C., 1999. The role of amoebocytes in the endotoxin-mediated coagulation in the innate immunity of Achatina fulica snail, Scand. J. Immunol. 49, 131-138). We now demonstrate that Achatinin participates in LPS-mediated coagulation of AAL as indicated by enhanced release of Achatinin from the LPS stimulated amoebocytes and most importantly, by exhibiting a 77% decline in the coagulation of AAL when depleted of Achatinin. Level of Achatinin sharply declined (17-fold) following injection of LPS (20 microg per snail) to the snails, which was reversible by simultaneous injection of LPS and leupeptin implying the presence of LPS-mediated serine protease activity in Achatinin. This was substantiated when purified Achatinin in vitro showed serine protease activity in the presence of LPS followed by its complete blockage in the presence of leupeptin and phenyl methyl sulphonyl fluoride. Therefore, Achatinin, an abundantly available lectin at multiple sites of A. fulica, by virtue of its interaction with LPS, essentially plays a crucial role in the innate immune protection of A. fulica snails.

Cervical lesions are associated with human papillomavirus type 16 intratypic variants that have high transcriptional activity and increased usage of common mammalian codons

Human papillomavirus type 16 (HPV-16) is a major cause of cervical neoplasia, but only a minority of HPV-16 infections result in cancer. Whether particular HPV-16 variants are associated with cervical disease has not yet been clearly established. An investigation of whether cervical neoplasia is associated with infection with HPV-16 intratypic variants was undertaken by using RFLP analyses in a study of 100 HPV-16 DNA-positive women with or without neoplasia. RFLP variant 2 was positively associated [odds ratio (OR)=2.57] and variant 5 was negatively associated with disease (OR=0.2). Variant 1, which resembles the reference isolate of HPV-16, was found at a similar prevalence among those with and without neoplasia. Variants 1 and 2 were also more likely to be associated with detectable viral mRNA than variant 5 (respectively P=0.03 and P=0.00). When HPV-16 E5 ORFs in 50 clones from 36 clinical samples were sequenced, 19 variant HPV-16 E5 DNA sequences were identified. Twelve of these DNA sequences encoded variant E5 amino acid sequences, 10 of which were novel. Whilst the associations between HPV-16 E5 RFLP variants and neoplasia could not be attributed to differences in amino acid sequences, correlation was observed in codon usage. DNA sequences of RFLP variant 2 (associated with greatest OR for neoplasia) had a significantly greater usage of common mammalian codons compared with RFLP pattern 1 variants.

Novel peroxisome proliferator-activated receptor (PPAR) gamma and PPARdelta ligands produce distinct biological effects

The peroxisome proliferator-activated receptors (PPARs) include three receptor subtypes encoded by separate genes: PPARalpha, PPARdelta, and PPARgamma. PPARgamma has been implicated as a mediator of adipocyte differentiation and the mechanism by which thiazolidinedione drugs exert in vivo insulin sensitization. Here we characterized novel, non-thiazolidinedione agonists for PPARgamma and PPARdelta that were identified by radioligand binding assays. In transient transactivation assays these ligands were agonists of the receptors to which they bind. Protease protection studies showed that ligand binding produced specific alterations in receptor conformation. Both PPARgamma and PPARdelta directly interacted with a nuclear receptor co-activator (CREB-binding protein) in an agonist-dependent manner. Only the PPARgamma agonists were able to promote differentiation of 3T3-L1 preadipocytes. In diabetic db/db mice all PPARgamma agonists were orally active insulin-sensitizing agents producing reductions of elevated plasma glucose and triglyceride concentrations. In contrast, selective in vivo activation of PPARdelta did not significantly affect these parameters. In vivo PPARalpha activation with WY-14653 resulted in reductions in elevated triglyceride levels with minimal effect on hyperglycemia. We conclude that: 1) synthetic non-thiazolidinediones can serve as ligands of PPARgamma and PPARdelta; 2) ligand-dependent activation of PPARdelta involves an apparent conformational change and association of the receptor ligand binding domain with CREB-binding protein; 3) PPARgamma activation (but not PPARdelta or PPARalpha activation) is sufficient to potentiate preadipocyte differentiation; 4) non-thiazolidinedione PPARgamma agonists improve hyperglycemia and hypertriglyceridemia in vivo; 5) although PPARalpha activation is sufficient to affect triglyceride metabolism, PPARdelta activation does not appear to modulate glucose or triglyceride levels.

The role of amoebocytes in endotoxin-mediated coagulation in the innate immunity of Achatina fulica snails

Achatina amoebocyte lysate (AAL) derived from amoebocytes of Achatina fulica was activated by Gram-negative bacterial endotoxins in a time-dependent manner resulting in gel formation/coagulation. The activation and maximum proliferation of amoebocytes was observed 40 min after intramuscular injection (20 microg/snail) of endotoxin. Endotoxin-mediated proteolytic activity of AAL towards a serine-protease-specific chromogenic substrate was maximum at pH 8.0, 37 degrees C and within 15 min in a divalent-cation-dependent manner. The AAL activity induced by the endotoxin was directly dependent on the endotoxin concentration, showed a high specificity and saturated at higher endotoxin concentrations. An endotoxin-sensitive factor (ESF) was purified from AAL to apparent homogeneity by single-step affinity chromatography on a heparin-Sepharose 4B column. Native ESF of molecular weight 140 000 was composed of two identical subunits of molecular weight 70 000 attached through non-covalent association. A strong binding to endotoxin (Escherichia coli 055:B5) was exhibited by ESF with a 40-fold higher biological activity than AAL. The ESF was shown to have a unique Phe-Ile active site with regard to its alternate activation by alpha-chymotrypsin instead of endotoxin. The ESF was characterized as a serine protease type as evidenced by potent inhibition with specific inhibitors.

Characterization of the gene for human EMMPRIN, a tumor cell surface inducer of matrix metalloproteinases

EMMPRIN (extracellular matrix metalloproteinase inducer) also known as CD147 and basigin, is a member of the immunoglobulin family that is present on the surface of tumor cells and stimulates nearby fibroblasts to synthesize matrix metalloproteinases. Using our EMMPRIN cDNA, we have isolated a cosmid clone that contains the human EMMPRIN gene. S1 analysis with a fragment of the gene clone and primer extension of the mRNA was performed to determine the transcription start site. PCR and sequence analysis have defined the exon/intron organization of the gene and show that it is highly conserved with the mouse EMMPRIN/basigin gene. About 950 bases of the 5'-flanking region were examined for transcription factor consensus binding sites, locating three SP1 sites and two AP2 sites. The transcription start site was found to be located in a CpG island. Elements in the proximal promoter region were conserved in the human and mouse genes.

Proliferative T-cell responses to human papillomavirus type 16 E5 are decreased amongst women with high-grade neoplasia

Proliferative responses to human papillomavirus type 16 (HPV-16) E5 peptides were determined for short-term cell lines derived from peripheral blood mononuclear cells of 75 women. Cell lines from 16 of the 75 women proliferated in response to stimulation with pooled E5 peptides; this was most common for patients with low-grade squamous cervical intraepithelial lesions (LSIL; 6 of 15 patients, 40%) and less frequent for asymptomatic women with no cervical lesions (4 of 20, 20%), those with high-grade squamous intraepithelial lesions(HSIL; 5 of 33, 15%) and others with cervical cancer (1 of 7, 14%, P = 0.027). Amongst these patients, proliferative responses were exclusive to those that were positive for HPV-16 DNA (12 of 41, 29%; c.f. none of 13 HPV-16 DNA-negative subjects exhibited a proliferative response; P= 0023) and were again most prevalent amongst HPV-16 DNA-positive LSIL (6 of 14, 43%), as compared with HPV-16 DNA-positive HSIL (5 of 23, 22%) or HPV-16 DNA-positive cervical cancer patients (1 of 4, 25%, P > 0.05). In contrast, for asymptomatic women, responsiveness was statistically independent of HPV-16 DNA status, i.e. responsiveness in HPV-16 DNA-positive and DNA-negative subjects was observed in 3 of 15 (20%) and 1 of 5 (20%) cases, respectively (P > 0.05). There were no associations between detection of HPV-16 mRNA and proliferative responses (P> 0.05). These data suggest that HPV-16 E5-specific T-helper activity is depressed amongst women with HSIL lesions.

Detection of human papillomavirus type 16 early-gene transcription by reverse transcription-PCR is associated with abnormal cervical cytology

Human papillomavirus type 16 (HPV-16) is associated with abnormal Papanicolou smears, indicative of cervical intraepithelial neoplasia. HPV-16 is the most common genital HPV and is found in up to 40% of young women with normal cervical cytology. In order to investigate whether transcriptionally active HPV-16 infection is associated with abnormal cervical smears, a reverse transcription-nested PCR assay with primers from the E5 open reading frame was developed to detect all HPV-16 early-region mRNA (E-mRNA) transcripts. It was used to study HPV-16-infected women with normal and abnormal cervical cytologies to obtain evidence of active infection. Among HPV-16 DNA-positive women, HPV-16 E-mRNA was detected in 15 of 37 (40.5%) women with abnormal cervical cytology but in only 4 of 35 (11.4%) women with normal cytology (P = 0.007). Thus, HPV-16 E-mRNA transcription is associated with abnormal cervical smears and may have value as a prognostic marker of progressive disease.

Stimulation of matrix metalloproteinase production by recombinant extracellular matrix metalloproteinase inducer from transfected Chinese hamster ovary cells

Many of the tumor-associated matrix metalloproteinases that are implicated in metastasis are produced by stromal fibroblasts within or surrounding the tumor in response to stimulation by factors produced by tumor cells. In this study we transfected Chinese hamster ovary cells with putative cDNA for human extracellular matrix metalloproteinase inducer (EMMPRIN), a transmembrane glycoprotein that is attached to the surface of many types of malignant human tumor cells and that has previously been implicated in stimulation of matrix metalloproteinase production in fibroblasts. We show that these transfected cells synthesize EMMPRIN that is extensively post-translationally processed; this recombinant EMMPRIN stimulates human fibroblast production of interstitial collagenase, stromelysin-1, and gelatinase A (72-kDa type IV collagenase). We propose that EMMPRIN regulates matrix metalloproteinase production during tumor invasion and other processes involving tissue remodeling.

Serine proteinase from rice bean

A trypsin like serine-proteinase of M(r) 16,000 Da, optimally active at pH 8.4 on N-benzoyl-arginine ethyl ester (BAEE) was purified from 4-day old germinated seeds of rice bean, Vigna umbellata (Thunb), by ammonium sulphate precipitation, gel filtration, ion-exchange chromatography and by high performance liquid chromatography (HPLC). The purity of the enzyme was checked by polyacrylamide gel electrophoresis (PAGE). The enzyme activity was studied on natural substrates like casein, haemoglobin and vicilin, a rice bean storage protein. The activity of the enzyme was completely inhibited by phenylmethylsulfonyl fluoride, but not by iodoacetamide and HgCl2, suggesting it to be a serine protease. Loss of activity in presence of EDTA was reversed by addition of Ca2+.

Thiazolidinediones produce a conformational change in peroxisomal proliferator-activated receptor-gamma: binding and activation correlate with antidiabetic actions in db/db mice

The thiazolidinediones are novel insulin sensitizers that serve as orally active antidiabetic agents, in rodents, nonhuman primates, and man. We have examined the effects of 4-week oral administration of three thiazolidinediones (AD-5075, BRL 49653, and CS-045) on plasma glucose and triglyceride concentrations in obese hyperglycemic db/db mice. All three agents lower plasma glucose and triglyceride concentrations. Normal levels of glucose are achieved after treatment with AD-5075 (> 1.7 mg/kg) or BRL 49653 (> or = 30 mg/kg), whereas CS-045 (100 or 300 mg/kg) produces only modest reductions in either parameter. Although the thiazolidinediones have demonstrated insulin-sensitizing activities both in vivo and in vitro, their primary molecular target has been unclear. We have compared the in vivo antidiabetic actions described above with the in vitro activities on peroxisomal proliferator-activated receptor-gamma (PPAR gamma). Hamster PPAR gamma 1 was transiently expressed in COS-1 cells to study the binding of [3H]AD-5075. The concentrations of compounds needed to displace radiolabeled AD-5075 from PPAR gamma correlate with their in vivo potency; the Ki values for displacement by cold AD-5075, BRL 49653, and CS-045 are 22, 68, and 1600 nM, respectively. To examine activation of the receptor, it was transiently cotransfected into COS-1 cells with a reporter plasmid containing two copies of a peroxisome proliferator response element. The EC50 values for activation are 2, 6, and 140 nM for AD-5075, BRL 49653, and CS-045, respectively. We have also analyzed limited proteolytic digests of in vitro translated hamster PPAR gamma. The thiazolidinediones produce a conformational change in PPAR gamma analogous to those produced by agonists of other nuclear hormone receptors. In the presence of saturating concentrations of either AD-5075 or BRL 49653, a receptor fragment of 27 kDa is protected from proteolysis by trypsin. These data support the conclusion that the antidiabetic actions of the thiazolidinediones are directly mediated through binding to PPAR gamma and the resulting active conformation of the receptor. Therefore, binding and transactivation assays using PPAR gamma should serve to identify other novel therapeutic agents with potential antidiabetic activities.

Analytic sensitivities of hybrid-capture, consensus and type-specific polymerase chain reactions for the detection of human papillomavirus type 16 DNA

Human papillomavirus type 16 (HPV-16) DNA is detected commonly in cervical carcinomas; in this study, we have determined the analytical sensitivities of Hybrid Capture, HPV-consensus PCR, and three HPV-16-specific polymerase chain reactions (PCRs) for the detection of HPV-16 DNA. Samples investigated included a cervical cancer cell line, cervical scrapes from 20 patients attending colposcopy clinics, and buccal swabs from eight immunosuppressed children. HPV-16 E7 and E5-nested PCRs [Cavuslu et al. (1996): Journal of Virological Methods, in press] produced positive signals from samples containing fewer than ten HPV-16 genomes per reaction. HPV-consensus PCR [Manos et al. (1989): Cancer Cells 7:209-214] and HPV-16 PCR using primers of van den Brule et al. [(1990): Journal of Clinical Microbiology 25:2739-2743] were of intermediate sensitivity (i.e., produced positive signals from samples containing 250 and 2,500 HPV-16 genoms/reaction, respectively) and Hybrid Capture could detect just 50,000 HPV-16 genomes/reaction. Highest rates of positivity for cervical samples were detected with HPV-16 E7 or E5-nested PCRs [50% (10 of 20 samples) and 60% (12 of 20 samples) positive, respectively], intermediate rates with HPV-consensus PCR and PCRs using the primers of van den Brule et al. [both 35% (7 of 20 samples)], and lowest rates of positivity [25% (5 of 20 samples)] with Hybrid Capture. None of eight buccal swab samples from immunosuppressed children were positive by Hybrid Capture, yet three (37.5%) were positive by HPV-16 E5-nested PCR. These data indicate that HPV-16 type-specific PCRs should be used for the investigation of specimens that may contain low amounts of HPV-16 DNA.

Human papillomavirus type 16 in infants: use of DNA sequence analyses to determine the source of infection

Perinatal transmission of human papillomavirus type 16 (HPV-16) and persistence of virus DNA in infants until 6 months of age has been described. To confirm the origin of infant infections as maternal, we determined the nucleotide sequence of the upstream regulatory region (URR; bp 7540 to 157) of HPV-16 in samples from 13 HPV-16 DNA-positive mothers and their infants at 6 weeks and 2 years of age. Identical HPV-16 variant URR sequences were found in two mother/infant samples and similar variants were found in three sets. Four mothers with samples which contained prototypic HPV-16 sequences delivered infants who also had the prototypic sequence. Four mothers with variant URRs delivered infants who harboured either prototypic or different URR variants. Thus, concordant variants or prototypic sequences were detected in nine of 13 mother/infant samples, indicating that up to 69.2% of HPV-16-positive infants acquire virus from their mothers.

An antidiabetic thiazolidinedione potentiates insulin stimulation of glycogen synthase in rat adipose tissues

Thiazolidinedione derivatives are a novel class of insulin-sensitizing agents that have demonstrated effective antidiabetic activity in vivo. Here, the effects of the potent thiazolidinedione derivative, AD-5075, on the rate-limiting enzyme of glycogen synthesis, glycogen synthase, were investigated in cultured rat adipose tissue. Short term preincubation of adipose tissue with AD-5075 potentiated acute insulin stimulation of I-form glycogen synthase activity in a concentration-dependent (EC50 approximately, 61nM) and time-dependent (t1/2 approximately, 2.3 h) manner. The thiazolidinedione derivative increased the responsiveness of I-form glycogen synthase activity to insulin stimulation at both maximal and submaximal insulin concentrations. In contrast, it had no effect on total glycogen synthase activity. Isoproterenol inhibited acute insulin activation of I-form glycogen synthase activity in a dose-dependent manner; maximal inhibition was attained at a concentration of 3 nM. AD-5075 antagonized isoproterenol inhibition of insulin's action. The concentration of glycogenolytic agent required to attain maximal inhibition was increased an order of magnitude in tissue treated with the antidiabetic agent. Short term preincubation of adipose tissue under hyperglycemic conditions (15 or 25 mM glucose) decreased insulin-stimulated I-form glycogen synthase activity. Concurrent treatment of the tissue with AD-5075 abrogated this glucose toxicity-induced inhibition of insulin action. Wortmannin, an inhibitor of phosphatidylinositol 3-kinase, blocked insulin activation of glycogen synthase in a dose-dependent manner. Half-maximal inhibition was observed at approximately 0.3 microM, and maximal inhibition occurred at 1.0 microM. AD-5075 did not antagonize wortmannin's inhibitory action. These results indicate that thiazolidinediones can act directly on adipose tissues to augment an important metabolic effect of insulin and counteract the inhibitory effects of catecholamines or hyperglycemia. As insulin stimulation of glycogen synthase remains wortmannin inhibitable in the presence of AD-5075, the effects of thiazolidinediones on insulin signal transduction may be phosphatidylinositol 3-kinase-dependent.

Detection of human papillomavirus type-16 DNA utilising microtitre-plate based amplification reactions and a solid-phase enzyme-immunoassay detection system

The development of a nested polymerase chain reaction (PCR) assay to detect low concentrations of human papillomavirus type-16 (HPV-16) DNA for epidemiological studies is described. The PCR utilises primers located in the E5 open reading frame, has an analytical sensitivity of 4 HPV-16 genomes and does not produce amplicons from other common genital HPVs (types-6, -11, -18, -31 and 33). This assay was carried out in 96-well plates utilising internal primers labelled with dinitrophenol (DNP) and biotin so that amplicons can be captured onto streptavidincoated plates and detected using an alkaline phosphatase-labelled monoclonal antibody to DNP. The assay was effective for detecting HPV-16 DNA in plasmids, cell-lines and, both freshly collected or archival (formalin-fixed/paraffin embedded) clinical specimens. This system is therefore suitable for epidemiological studies to identify individuals infected with HPV-16 DNA in episomal form who may be at increased risk of developing anogenital carcinomas.