Reference genome assembly for Australian Ascochyta lentis isolate Al4

Ascochyta lentis causes ascochyta blight in lentil (Lens culinaris Medik.) and yield loss can be as high as 50%. With careful agronomic management practices, fungicide use, and advances in breeding resistant lentil varieties, disease severity and impact to farmers have been largely controlled. However, evidence from major lentil producing countries, Canada and Australia, suggests that A. lentis isolates can change their virulence profile and level of aggressiveness over time and under different selection pressures. In this paper, we describe the first genome assembly for A. lentis for the Australian isolate Al4, through the integration of data from Illumina and PacBio SMRT sequencing. The Al4 reference genome assembly is almost 42 Mb in size and encodes 11,638 predicted genes. The Al4 genome comprises 21 full-length and gapless chromosomal contigs and two partial chromosome contigs each with one telomere. We predicted 31 secondary metabolite clusters, and 38 putative protein effectors, many of which were classified as having an unknown function. Comparison of A. lentis genome features with the recently published reference assembly for closely related A. rabiei show that genome synteny between these species is highly conserved. However, there are several translocations and inversions of genome sequence. The location of secondary metabolite clusters near transposable element and repeat-rich genomic regions was common for A. lentis as has been reported for other fungal plant pathogens.

Accessories Make the Outfit: Accessory Chromosomes and Other Dispensable DNA Regions in Plant-Pathogenic Fungi

Fungal pathogen genomes can often be divided into core and accessory regions. Accessory regions ARs) may be comprised of either ARs (within core chromosomes (CCs) or wholly dispensable (accessory) chromosomes (ACs). Fungal ACs and ARs typically accumulate mutations and structural rearrangements more rapidly over time than CCs and many harbor genes relevant to host-pathogen interactions. These regions are of particular interest in plant pathology and include host-specific virulence factors and secondary metabolite synthesis gene clusters. This review outlines known ACs and ARs in fungal genomes, methods used for their detection, their common properties that differentiate them from the core genome, and what is currently known of their various roles in pathogenicity. Reports on the evolutionary processes generating and shaping AC and AR compartments are discussed, including repeat induced point mutation and breakage fusion bridge cycles. Previously ACs have been studied extensively within key genera, including Fusarium, Zymoseptoria, and Alternaria, but are growing in frequency of observation and perceived importance across a wider range of fungal species. Recent advances in sequencing technologies permit affordable genome assembly and resequencing of populations that will facilitate further discovery and routine screening of ACs.

Transcriptome analysis of the fungal pathogen Fusarium oxysporum f. sp. medicaginis during colonisation of resistant and susceptible Medicago truncatula hosts identifies differential pathogenicity profiles and novel candidate effectors

BACKGROUND

Pathogenic members of the Fusarium oxysporum species complex are responsible for vascular wilt disease on many important crops including legumes, where they can be one of the most destructive disease causing necrotrophic fungi. We previously developed a model legume-infecting pathosystem based on the reference legume Medicago truncatula and a pathogenic F. oxysporum forma specialis (f. sp.) medicaginis (Fom). To dissect the molecular pathogenicity arsenal used by this root-infecting pathogen, we sequenced its transcriptome during infection of a susceptible and resistant host accession.

RESULTS

High coverage RNA-Seq of Fom infected root samples harvested from susceptible (DZA315) or resistant (A17) M. truncatula seedlings at early or later stages of infection (2 or 7 days post infection (dpi)) and from vegetative (in vitro) samples facilitated the identification of unique and overlapping sets of in planta differentially expressed genes. This included enrichment, particularly in DZA315 in planta up-regulated datasets, for proteins associated with sugar, protein and plant cell wall metabolism, membrane transport, nutrient uptake and oxidative processes. Genes encoding effector-like proteins were identified, including homologues of the F. oxysporum f. sp. lycopersici Secreted In Xylem (SIX) proteins, and several novel candidate effectors based on predicted secretion, small protein size and high in-planta induced expression. The majority of the effector candidates contain no known protein domains but do share high similarity to predicted proteins predominantly from other F. oxysporum ff. spp. as well as other Fusaria (F. solani, F. fujikori, F. verticilloides, F. graminearum and F. pseudograminearum), and from another wilt pathogen of the same class, a Verticillium species. Overall, this suggests these novel effector candidates may play important roles in Fusaria and wilt pathogen virulence.

CONCLUSION

Combining high coverage in planta RNA-Seq with knowledge of fungal pathogenicity protein features facilitated the identification of differentially expressed pathogenicity associated genes and novel effector candidates expressed during infection of a resistant or susceptible M. truncatula host. The knowledge from this first in depth in planta transcriptome sequencing of any F. oxysporum ff. spp. pathogenic on legumes will facilitate the dissection of Fusarium wilt pathogenicity mechanisms on many important legume crops.

Comparative genomics and prediction of conditionally dispensable sequences in legume-infecting Fusarium oxysporum formae speciales facilitates identification of candidate effectors

BACKGROUND

Soil-borne fungi of the Fusarium oxysporum species complex cause devastating wilt disease on many crops including legumes that supply human dietary protein needs across many parts of the globe. We present and compare draft genome assemblies for three legume-infecting formae speciales (ff. spp.): F. oxysporum f. sp. ciceris (Foc-38-1) and f. sp. pisi (Fop-37622), significant pathogens of chickpea and pea respectively, the world's second and third most important grain legumes, and lastly f. sp. medicaginis (Fom-5190a) for which we developed a model legume pathosystem utilising Medicago truncatula.

RESULTS

Focusing on the identification of pathogenicity gene content, we leveraged the reference genomes of Fusarium pathogens F. oxysporum f. sp. lycopersici (tomato-infecting) and F. solani (pea-infecting) and their well-characterised core and dispensable chromosomes to predict genomic organisation in the newly sequenced legume-infecting isolates. Dispensable chromosomes are not essential for growth and in Fusarium species are known to be enriched in host-specificity and pathogenicity-associated genes. Comparative genomics of the publicly available Fusarium species revealed differential patterns of sequence conservation across F. oxysporum formae speciales, with legume-pathogenic formae speciales not exhibiting greater sequence conservation between them relative to non-legume-infecting formae speciales, possibly indicating the lack of a common ancestral source for legume pathogenicity. Combining predicted dispensable gene content with in planta expression in the model legume-infecting isolate, we identified small conserved regions and candidate effectors, four of which shared greatest similarity to proteins from another legume-infecting ff. spp.

CONCLUSIONS

We demonstrate that distinction of core and potential dispensable genomic regions of novel F. oxysporum genomes is an effective tool to facilitate effector discovery and the identification of gene content possibly linked to host specificity. While the legume-infecting isolates didn't share large genomic regions of pathogenicity-related content, smaller regions and candidate effector proteins were highly conserved, suggesting that they may play specific roles in inducing disease on legume hosts.

Comprehensive Annotation of the Parastagonospora nodorum Reference Genome Using Next-Generation Genomics, Transcriptomics and Proteogenomics

Parastagonospora nodorum, the causal agent of Septoria nodorum blotch (SNB), is an economically important pathogen of wheat (Triticum spp.), and a model for the study of necrotrophic pathology and genome evolution. The reference P. nodorum strain SN15 was the first Dothideomycete with a published genome sequence, and has been used as the basis for comparison within and between species. Here we present an updated reference genome assembly with corrections of SNP and indel errors in the underlying genome assembly from deep resequencing data as well as extensive manual annotation of gene models using transcriptomic and proteomic sources of evidence (https://github.com/robsyme/Parastagonospora_nodorum_SN15). The updated assembly and annotation includes 8,366 genes with modified protein sequence and 866 new genes. This study shows the benefits of using a wide variety of experimental methods allied to expert curation to generate a reliable set of gene models.

Genetic association of CD247 (CD3ζ) with SLE in a large-scale multiethnic study

A classic T-cell phenotype in systemic lupus erythematosus (SLE) is the downregulation and replacement of the CD3ζ chain that alters T-cell receptor signaling. However, genetic associations with SLE in the human CD247 locus that encodes CD3ζ are not well established and require replication in independent cohorts. Our aim was therefore to examine, localize and validate CD247-SLE association in a large multiethnic population. We typed 44 contiguous CD247 single-nucleotide polymorphisms (SNPs) in 8922 SLE patients and 8077 controls from four ethnically distinct populations. The strongest associations were found in the Asian population (11 SNPs in intron 1, 4.99 × 10(-4) < P < 4.15 × 10(-2)), where we further identified a five-marker haplotype (rs12141731-rs2949655-rs16859085-rs12144621-rs858554; G-G-A-G-A; P(hap) = 2.12 × 10(-5)) that exceeded the most associated single SNP rs858554 (minor allele frequency in controls = 13%; P = 4.99 × 10(-4), odds ratio = 1.32) in significance. Imputation and subsequent association analysis showed evidence of association (P < 0.05) at 27 additional SNPs within intron 1. Cross-ethnic meta-analysis, assuming an additive genetic model adjusted for population proportions, showed five SNPs with significant P-values (1.40 × 10(-3) < P< 3.97 × 10(-2)), with one (rs704848) remaining significant after Bonferroni correction (P(meta) = 2.66 × 10(-2)). Our study independently confirms and extends the association of SLE with CD247, which is shared by various autoimmune disorders and supports a common T-cell-mediated mechanism.

Evaluation of Secretion Prediction Highlights Differing Approaches Needed for Oomycete and Fungal Effectors

The steadily increasing number of sequenced fungal and oomycete genomes has enabled detailed studies of how these eukaryotic microbes infect plants and cause devastating losses in food crops. During infection, fungal and oomycete pathogens secrete effector molecules which manipulate host plant cell processes to the pathogen's advantage. Proteinaceous effectors are synthesized intracellularly and must be externalized to interact with host cells. Computational prediction of secreted proteins from genomic sequences is an important technique to narrow down the candidate effector repertoire for subsequent experimental validation. In this study, we benchmark secretion prediction tools on experimentally validated fungal and oomycete effectors. We observe that for a set of fungal SwissProt protein sequences, SignalP 4 and the neural network predictors of SignalP 3 (D-score) and SignalP 2 perform best. For effector prediction in particular, the use of a sensitive method can be desirable to obtain the most complete candidate effector set. We show that the neural network predictors of SignalP 2 and 3, as well as TargetP were the most sensitive tools for fungal effector secretion prediction, whereas the hidden Markov model predictors of SignalP 2 and 3 were the most sensitive tools for oomycete effectors. Thus, previous versions of SignalP retain value for oomycete effector prediction, as the current version, SignalP 4, was unable to reliably predict the signal peptide of the oomycete Crinkler effectors in the test set. Our assessment of subcellular localization predictors shows that cytoplasmic effectors are often predicted as not extracellular. This limits the reliability of secretion predictions that depend on these tools. We present our assessment with a view to informing future pathogenomics studies and suggest revised pipelines for secretion prediction to obtain optimal effector predictions in fungi and oomycetes.

The genome sequence of the biocontrol fungus Metarhizium anisopliae and comparative genomics of Metarhizium species

Background

Metarhizium anisopliae is an important fungal biocontrol agent of insect pests of agricultural crops. Genomics can aid the successful commercialization of biopesticides by identification of key genes differentiating closely related species, selection of virulent microbial isolates which are amenable to industrial scale production and formulation and through the reduction of phenotypic variability. The genome of Metarhizium isolate ARSEF23 was recently published as a model for M. anisopliae, however phylogenetic analysis has since re-classified this isolate as M. robertsii. We present a new annotated genome sequence of M. anisopliae (isolate Ma69) and whole genome comparison to M. robertsii (ARSEF23) and M. acridum (CQMa 102).

Results

Whole genome analysis of M. anisopliae indicates significant macrosynteny with M. robertsii but with some large genomic inversions. In comparison to M. acridum, the genome of M. anisopliae shares lower sequence homology. While alignments overall are co-linear, the genome of M. acridum is not contiguous enough to conclusively observe macrosynteny. Mating type gene analysis revealed both MAT1-1 and MAT1-2 genes present in M. anisopliae suggesting putative homothallism, despite having no known teleomorph, in contrast with the putatively heterothallic M. acridum isolate CQMa 102 (MAT1-2) and M. robertsii isolate ARSEF23 (altered MAT1-1). Repetitive DNA and RIP analysis revealed M. acridum to have twice the repetitive content of the other two species and M. anisopliae to be five times more RIP affected than M. robertsii. We also present an initial bioinformatic survey of candidate pathogenicity genes in M. anisopliae.

Conclusions

The annotated genome of M. anisopliae is an important resource for the identification of virulence genes specific to M. anisopliae and development of species- and strain- specific assays. New insight into the possibility of homothallism and RIP affectedness has important implications for the development of M. anisopliae as a biopesticide as it may indicate the potential for greater inherent diversity in this species than the other species. This could present opportunities to select isolates with unique combinations of pathogenicity factors, or it may point to instability in the species, a negative attribute in a biopesticide.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2164-15-660) contains supplementary material, which is available to authorized users.

Genome sequencing and comparative genomics of the broad host-range pathogen Rhizoctonia solani AG8

Rhizoctonia solani is a soil-borne basidiomycete fungus with a necrotrophic lifestyle which is classified into fourteen reproductively incompatible anastomosis groups (AGs). One of these, AG8, is a devastating pathogen causing bare patch of cereals, brassicas and legumes. R. solani is a multinucleate heterokaryon containing significant heterozygosity within a single cell. This complexity posed significant challenges for the assembly of its genome. We present a high quality genome assembly of R. solani AG8 and a manually curated set of 13,964 genes supported by RNA-seq. The AG8 genome assembly used novel methods to produce a haploid representation of its heterokaryotic state. The whole-genomes of AG8, the rice pathogen AG1-IA and the potato pathogen AG3 were observed to be syntenic and co-linear. Genes and functions putatively relevant to pathogenicity were highlighted by comparing AG8 to known pathogenicity genes, orthology databases spanning 197 phytopathogenic taxa and AG1-IA. We also observed SNP-level "hypermutation" of CpG dinucleotides to TpG between AG8 nuclei, with similarities to repeat-induced point mutation (RIP). Interestingly, gene-coding regions were widely affected along with repetitive DNA, which has not been previously observed for RIP in mononuclear fungi of the Pezizomycotina. The rate of heterozygous SNP mutations within this single isolate of AG8 was observed to be higher than SNP mutation rates observed across populations of most fungal species compared. Comparative analyses were combined to predict biological processes relevant to AG8 and 308 proteins with effector-like characteristics, forming a valuable resource for further study of this pathosystem. Predicted effector-like proteins had elevated levels of non-synonymous point mutations relative to synonymous mutations (dN/dS), suggesting that they may be under diversifying selection pressures. In addition, the distant relationship to sequenced necrotrophs of the Ascomycota suggests the R. solani genome sequence may prove to be a useful resource in future comparative analysis of plant pathogens.

Phoma medicaginis stimulates the induction of the octadecanoid and phenylpropanoid pathways in Medicago truncatula

Gene expression changes and metabolite abundances were measured during the interaction of Medicago truncatula with the fungal necrotrophic pathogen Phoma medicaginis in leaf tissue of susceptible and resistant accessions. Over 330 genes were differentially expressed in plants infected with P. medicaginis relative to mock-inoculated plants at 12 h post-inoculation. Of these, 191 were induced in either the resistant or the susceptible accession, with 143 genes repressed. Expression changes were observed in genes involved in the oxidative burst, cell wall strengthening and lipid metabolism, as well as several transcription factors. Genes related to salicylic acid, jasmonate and ethylene responses were up-regulated, as well as genes leading to the production of jasmonic acid. Significant induction of genes in the phenylpropanoid pathway leading to lignin and isoflavonoid biosynthesis occurred. High-pressure liquid chromatography with UV detection (HPLC-UV) identified several phenolic compounds induced by P. medicaginis, as well as constitutively higher levels of phenolic compounds, in the resistant M. truncatula accession. Differentially regulated genes induced in both the resistant and susceptible accessions, but with different kinetics, and constitutively more highly expressed and induced phenolic compounds provide candidates for functional analysis. Taken together, these results highlight the importance of the octadecanoid and phenylpropanoid pathways in defence against this necrotrophic pathogen.

The Medicago truncatula reference accession A17 has an aberrant chromosomal configuration

Medicago truncatula (barrel medic) has emerged as a model legume and accession A17 is the reference genotype selected for the sequencing of the genome. In the present study we compare the A17 chromosomal configuration with that of other accessions by examining pollen viability and genetic maps of intraspecific hybrids. Hybrids derived from crosses between M. truncatula accessions, representative of the large genetic variation within the germplasm collection, were evaluated for pollen viability using Alexander's stain. Genetic maps were generated for the following crosses: SA27063 x SA3054 (n = 94), SA27063 x A17 (n = 92), A17 x Borung (n = 99) and A17 x A20 (n = 69). All F(1) individuals derived from crosses involving A17 showed 50% pollen viability or less. Examination of the recombination frequencies between markers of chromosomes 4 and 8 revealed an apparent genetic linkage between the lower arms of these chromosomes in genetic maps derived from A17. Semisterility and unexpected linkage relationship are both good indicators of a reciprocal translocation. The implications of the A17 distinctive chromosomal rearrangement on studies of genetic mapping, genome sequencing and synteny between species are discussed.

Loci contributing to adult height and body mass index in African American families ascertained for type 2 diabetes

Height and body mass index (BMI) have high heritability in most studies. High BMI and reduced height are well-recognized as important risk factors for a number of cardiovascular diseases. We investigated these phenotypes in African American families originally ascertained for studies of linkage with type 2 diabetes using self-reported height and weight. We conducted a genome wide scan in 221 families containing 580 individuals and 672 relative pairs of African American descent. Estimates of heritability and support for linkage were assessed by genetic variance component analyses using SOLAR software. The estimated heritabilities for height and BMI were 0.43 and 0.64, respectively. We have identified major loci contributing to variation in height on chromosomes 15 (LOD = 2.61 at 35 cM, p = 0.0004), 3 (LOD = 1.82 at 84 cM, p = 0.0029), 8 (LOD = 1.92 at 135 cM, p = 0.0024) and 17 (LOD = 1.70 at 110 cM, p = 0.0044). A broad region on chromosome 4 supported evidence of linkage to variation in BMI, with the highest LOD = 2.66 at 168 cM (p = 0.0005). Two height loci and two BMI loci appear to confirm the existence of quantitative trait loci previously identified by other studies, providing important replicative data to allow further resolution of linkage regions suitable for positional cloning of these cardiovascular disease risk loci.

Fine mapping chromosome 16q12 in a collection of 231 systemic lupus erythematosus sibpair and multiplex families

Systemic lupus erythematosus (SLE) is a chronic, autoimmune disorder influenced by multiple genetic and environmental factors. Linkage of SLE to chromosome 16q12-13 (LOD score=3.85) was first identified in pedigrees collected at the University of Minnesota, and has been replicated in several independent SLE collections. We performed fine mapping using microsatellites to further refine the susceptibility region(s), and the best evidence for linkage was identified at marker D16S3396 (LOD=2.28, P=0.0006). Evidence of association was suggested in the analysis of all families (D16S3094, P=0.0516) and improved to the level of significance (P=0.0106) when only the Caucasian families were analyzed. Subsets of pedigrees were then selected on the basis of clinical manifestations, and these subsets showed evidence for association with several markers: GATA143D05 (renal, P=0.0064), D16S3035 (renal, P=0.0418), D16S3117 (renal, P=0.0366), D16S3071 (malar rash, P=0.03638; neuropsychiatric, P=0.0349; oral ulcers, P=0.0459), D16S3094 (hematologic, P=0.0226), and D16S3089 (arthritis, P=0.0141). Together, these data provide further evidence that an important susceptibility gene(s) for SLE is located at 16q12.

Serum cystatin C in patients with myeloma

BACKGROUND

Cystatin C is a low molecular weight protein thought to be synthesised by all nucleated cells and freely filtered by the kidney. It has been proposed as a marker for GFR; however, it has been suggested that there may be limitations to its use, because it may be over-expressed in some tumour cells and the abnormal tissue growth may also lead to an increased circulating level.

METHODS

We investigated the serum cystatin C levels in 60 patients with myeloma, comparing results with those for serum creatinine, beta(2)-microglobulin and the paraprotein concentration.

RESULTS

We found no correlation between cystatin C and the paraprotein concentration in these patients.

CONCLUSION

These results suggest that disease burden does not correlate to the circulating level of cystatin C in patients with myeloma.

Private enterprise and public good: ethical issues in the funding of clinical research

Health-care centres, universities, and the researchers and clinicians working in them are encouraged to procure research funding through the development of commercial relationships. There are positive, practical, and morally relevant arguments in support of this initiative, but the move also raises ethical issues concerning potential conflicts of interest. These include conflicts between an institution's or researcher's responsibilities to each other, to research subjects, and to the public, and competing financial interests. This article examines developments in research funding and ethical difficulties that may arise in the present administrative context. It provides suggestions for the development of guidelines by institutions that are supportive of investigators in their endeavors to enhance clinical care through crucial external funding and the implementation of research.

Multiple myeloma: an immunoclinical study of disease and response to treatment

Plasma cytokines and immune markers were assessed during the clinical management of 42 patients with multiple myeloma, MM. Of the patients 22/42 (all with progressive disease) were studied from the time of diagnosis, through various treatment regimes, to remission, progression or death. 5/42 patients had monoclonal gammopathy of undetermined significance (MGUS), 8/42 others had either indolent MM or stable MM, and a further 7/42 with progressive disease were also studied. IL-6, TNF-alpha, IL-1 alpha, IL-1 beta, beta 2 microglobulin (beta 2M), and neopterin were estimated in bloods taken under optimal conditions for cytokine detection. The levels were compared with a panel of samples from healthy volunteers. Both immunoreactive and biologically active plasma IL-6 levels were measured. Pretreatment IL-6 levels (both immunoreactive and biologically active) were found to correlate with severity of disease. In 13/22 patients with progressive disease who had been followed from the time of diagnosis over a 12-month period or until death, pretreatment IL-6 levels were predictive of response to therapy. Elevated plasma levels of TNF-alpha, beta 2M and neopterin were found in patients with progressive multiple myeloma, and this correlated with renal impairment. The analytes measured during the course of chemotherapy did not show correlation with disease progression or response to therapy.

Myeloma during a decade: clinical experience in a single centre

One hundred and fifty-six patients with multiple myeloma were treated over a period of 12 years at St. Bartholomew's Hospital. The progress of the disease was affected in 96/156 patients (61%). Response was defined as achieving a plateau of M component. A partial or complete response was seen in 68/120 patients treated conventionally (56.5%), and in 28/36 patients treated with high-dose therapy (77.7%). The median survival of the group as a whole was 20 months, with a 2-year survival of just over 40%. In the 36 patients treated with high-dose therapy, median survival was 6 years, and in a small group who have had maintenance Interferon therapy, the median has not yet been reached. In a univariate analysis, age, intensity of therapy, haemoglobin and creatinine levels were significant, but multivariate analysis showed that only age and intensity of therapy were independent predictors for survival. The outlook for relapsed patients who showed progression of disease remains poor, but palliation was best achieved by steroid and Interferon in combination. Patients who achieve complete responses and are maintained on Interferon appear to be doing better both in terms of freedom from symptoms and in survival, and methods to enable an elderly population to tolerate this form of therapy need to be explored.

Treatment of young rams with an agonist of GnRH delays reproductive development

The objective of this study was to determine if the continuous treatment of young rams with an agonist of gonadotropin-releasing hormone (GnRH) in the period immediately prior to puberty would delay the onset of adult sexual behavior and retard testicular development. In the first experiment the GnRH agonist was shown to be effective in suppressing the plasma concentrations of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in adult wethers (neonatally castrated rams) when administered by either a biocompatible slow release implant (implant) or a mini osmotic pump (minipump) that released the agonist for 4 weeks. The minipumps were more effective than the implants in suppressing the secretion of LH and FSH. In a second experiment, administration of the GnRH agonist by implant or minipump to prepubertal rams for 16 weeks immediately prior to puberty inhibited the development of sexual behavior, reduced the plasma concentrations of testosterone, retarded testicular and epididymal development, and inhibited growth rates. The effects on sexual behavior were clearly reversible but testicular and epididymal weights were still reduced in treated rams 8 weeks after the end of treatment. These results indicate that the reproductive function of rams is sensitive to gonadotropins and testicular hormones immediately prior to puberty. The agonist of GnRH was successfully delivered to the rams in a biocompatible implant which may offer a practical means of manipulating reproductive function in young rams.

Effect of treatment with melatonin implants in conjunction with teaser rams on the reproductive performances of Poll Dorset x Merino ewes joined in early summer in the south-west of Western Australia

Melatonin pretreatment to improve the reproductive performance of first-cross Poll Dorset x Merino ewes joined in early summer was investigated in 2 experiments conducted in consecutive years. In experiment 1, melatonin pellets were administered subcutaneously to 1 of 3 groups of ewes; 14 days later they were joined with testosterone-primed wethers ('teasers'), followed after 15 days by entire rams (melatonin-teased group). The other groups were untreated and teased only. Experiment 2 consisted only of teased and melatonin-teased groups, with the ewes from experiment 1 being reallocated, as well as maiden ewes being joined for the first time. In this experiment melatonin pellets were inserted 38 days before the start of joining. Treatment with melatonin resulted in increased reproductive performances. The responses were characterised by an earlier (P<0.05) conception pattern in both experiments and higher (P<0.001) lambing percentages than controls in experiment 1. Up to 22% more lambs were born to melatonin-teased ewes than to teased ewes, and stimulatory effects were similar for ewes of different ages. In experiment 2, ewes that had received melatonin in both experiments tended (P>0.05) to have higher lambing percentages than teased ewes (up to 17% more lambs born), while ewes that had received melatonin in only experiment 1 tended (P>0.05) to have lower lambing percentages than ewes that were not treated with melatonin in either experiment (4-11%). The higher lambing performances of the melatonin-treated ewes were independent of ewe liveweights. Reproductive activity was also stimulated by the use of teasers alone in experiment 1. Conception patterns were advanced (P<0.01) and there was a trend for more (P>0.05) lambs to be born in the teased group than in the control group. The results show that both teasers and melatonin treatment will advance the conception patterns of first-cross Poll Dorset x Merino ewes joined in early summer, but the melatonin treatment also stimulated fecundity.

Infections due to gram-positive organisms in children: possible role for teicoplanin

The disruptive effect on, and potentially hazardous exposure to nosocomial infection, together with the relative cost of hospitalization, of children favours the need for ambulatory care. An increasing proportion of infections in children are due to beta-lactam resistant Gram-positive organisms. Teicoplanin is proposed as a suitable candidate for treating paediatric patients with serious Gram-positive infections in hospital or ambulatory care. The experience acquired in children is still limited. However, over 200 paediatric patients have been treated with once or twice daily im or iv teicoplanin in daily doses of 3-10 mg/kg. The main clinical diagnoses were skin and soft tissue infections, skeletal infections and septicaemia. The drug was safe and clinical efficacy was greater than 90%. Comparative studies with defined uniform protocols are now required to assess the potential of this drug.

Teicoplanin monotherapy of serious infections caused by gram-positive bacteria: a re-evaluation of patients with endocarditis or Staphylococcus aureus bacteraemia from a European open trial

We have examined case records for patients who received teicoplanin alone for endocarditis or Staphylococcus aureus bacteraemia. All patients with streptococcal endocarditis were cured (viridans group 14/14; Group D 4/4). Cure rates for other organisms were: Enterococcus faecalis 3/5; S. aureus 5/10 and coagulase negative staphylococci 2/3. Doses for six patients who failed because of poor response were 3.3-4.2 mg/kg. Teicoplanin treatment cured 41/48 patients with S. aureus bacteraemia; treatment failed in two patients because of adverse events. Doses in the remaining treatment failures were 2.1-5.0 mg/kg. In comparison, 48 patients in Dundee hospitals received ten different drugs in 20 combinations for S. aureus bacteraemia; 29 patients received cloxacillin or flucloxacillin but initial doses varied from 0.25-2.0 g. We conclude that the European database does provide evidence that teicoplanin monotherapy is effective for serious infection with Gram-positive bacteria. Doses for staphylococcal infection should probably be at least 6 mg/kg. The upper limit of the teicoplanin dosage range remains to be determined but there is evidently considerable confusion about appropriate regimens for 'standard' therapy.

A review of the safety profile of teicoplanin

Safety of teicoplanin has been assessed in 3377 patients treated in Europe up to the end of June 1990. One or more adverse events were experienced by 10% of patients. Age and teicoplanin dose had no significant effect on the incidence or type of adverse event. In comparative trials the incidence and profile of adverse events to teicoplanin have been similar to those seen with beta-lactam therapy. Impaired renal function occurred consistently more frequently with vancomycin therapy than with teicoplanin therapy, particularly when these drugs were co-administered with aminoglycosides. Severe skin reactions have not been reported with teicoplanin, which, unlike vancomycin, does not cause infusion rate-related release of histamine. These data provide further evidence that teicoplanin is safer than vancomycin and does not have dose-related adverse effects in the dose range 3-10 mg/kg.

Do patients presenting to accident and emergency departments have low serum anticonvulsant concentrations?

It is often felt that poorly controlled epileptic patients, who are taking anticonvulsant medication, are over represented in A&E departments compared to the general population. This A&E based study set out to determine whether such patients do have inadequate serum anticonvulsant levels, when they present following a seizure, to A&E departments. All epileptic patients, taking medication, who presented to the A&E departments of St. Bartholomew's and Hackney Hospitals, London, over a 4-month period were studied. Serum anticonvulsant concentrations were measured on their arrival in the departments. Forty-six patients were studied. Only 21% of anticonvulsant drug concentrations were within 'therapeutic' ranges. A total of 66% were below 'therapeutic' ranges and 13% were potentially toxic. The implication of these findings is discussed.

Modulation of expression of MHC antigens in the kidneys of mice by murine interferon-alpha/beta

We have analyzed the effects of interferon-alpha/beta on MHC expression in the murine kidney, and compared these results with the MHC modulating effects of interferon-gamma. Natural murine interferon-alpha/beta was administered to B10.BR mice (H-2k), i.p., twice daily for 3 days. Expression of MHC antigens was assessed on day 4 by immunoperoxidase staining with biotinylated monoclonal antibodies to class I (KkDk) and class II (I-Ak) antigens. Interferon-alpha/beta significantly decreased the number of class II-positive renal cortical dendritic cells from 62.0/mm2 to 12.6/mm2 (P less than 0.001). A similar but less dramatic decrease was seen in cardiac dendritic cells. Little or no change in class II expression was observed in proximal tubules or glomeruli. Interferon-alpha/beta induced marked class I staining in the glomerulus, arterial endothelium, and Bowman's capsule. Proximal tubule cells also showed increased class I expression, but were less responsive than glomeruli. Thus, the effects of interferon-alpha/beta contrast with those of interferon-gamma, which increases class II expression on proximal tubules, induces relatively more class I expression in proximal tubules than glomeruli, and increases class II-positive dendritic cells. Furthermore, these results suggest that treatment with interferon-alpha/beta may have a complex effect on the immune response to a renal allograft due to its differential effects on class I and class II cell surface expression.

Hospital CEO turnover: implications for trustees

Many turnovers are positive for both CEOs and organizations, but there is still cause for concern. Three hospital management experts analyze the results of a recent survey of CEO turnover and examine the concerns of hospital executives, employees, medical staff members, and trustees.

Direct single-reagent fluorescence polarisation immunoassay for valproic acid in serum

A fluorescence polarisation immunoassay for quantitating serum concentrations of valproic acid was developed and validated. Its low molecular weight and lack of structural features caused difficulties in producing suitable antibodies. However, success was achieved using 2-propyl-6-aminohexanoic acid to make the fluorescein-labelled drug and two immunogens, the first using glutaraldehyde to link the drug derivative to keyhole limpet haemocyanin, and the second by carbodiimide activation of cellulose hydroxyl groups and coupling them to the drug derivative and killed Mycobacteria. It was found that both immunogens produced a good antibody response in sheep. The antibodies were highly specific and the assay results correlated well with an in-house gas-liquid chromatographic method.

The use of a new glycopeptide antibiotic, teicoplanin, in the treatment of bacterial endocarditis

Teicoplanin, a new glycopeptide antibiotic, has been used to treat twelve patients with bacterial endocarditis due to Gram-positive organisms. Teicoplanin has activity against Gram-positive bacteria similar to vancomycin but therapeutic levels are maintained by a single daily dose, given as an intravenous bolus. Of six patients with native valve infections, two cases, due to viridans streptococci, were successfully treated with teicoplanin alone and two others, caused by Streptococcus faecalis, were cured by combinations including teicoplanin. One of these patients sustained high tone hearing loss during treatment. The remaining two patients were drug addicts with endocarditis due to Staphylococcus aureus which recurred despite repeated multiple therapy. Of six prosthetic valve infections, antibiotic combinations including teicoplanin cured three cases, caused by streptococci. Infection persisted or treatment was curtailed in three cases of Staphylococcus epidermidis endocarditis. In this small open study, teicoplanin appeared as effective as vancomycin in the treatment of endocarditis but had the considerable advantage of ease of administration.

Invasive pulmonary aspergillosis diagnosed by blood culture and successfully treated

We present a case of invasive pulmonary aspergillosis when a blood culture isolate of Aspergillus fumigatus in an unusual medium was considered to be a genuine isolation. Early institution of appropriate therapy was successful.

Ciprofloxacin and co-trimoxazole in urinary tract infection

Seventy-five hospital inpatients with bacteriologically confirmed urinary tract infections were allocated to treatment with ciprofloxacin 100 mg, ciprofloxacin 250 mg or co-trimoxazole 960 mg, all given orally twice a day for five days. The patients were generally elderly, with many complicating factors including indwelling catheters; 24% of the infections were caused by Pseudomonas aeruginosa. The cure rates at 28 days were 94%, 88% and 87%, respectively. Side effects were few and minor. Ciprofloxacin appears to be an effective and safe orally-administrable treatment even for complicated urinary tract infection.

Diagnosis of acute myocardial infarction at necropsy

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Course organizers in general practice

In August/September 1984 a survey of the 267 course organizers in post in England and Wales was carried out. Eighty-two per cent replied to a questionnaire asking for details about their work and personal status. All 16 regions in England and Wales completed a questionnaire about levels of staffing and remuneration of those involved in general practice postgraduate education. The results show that there are considerable variations between regions in the role and responsibilities of course organizers, in their training, and in the facilities that are provided for them. The majority of course organizers reported a workload greater than the number of sessions for which they were remunerated. The effects of these factors on recruitment, tenure of post, and job satisfaction are discussed. Recommendations are made for improving the situation, including the removal of course organizer pay from the scale of trainers' pay, so that there can be flexibility in the number of sessions which can be held, improvement in training and certain facilities, and the implementation of national and local job descriptions.

Teicoplanin in the treatment of infection caused by gram-positive organisms

Teicoplanin was used to treat 94 hospital in-patients of confirmed or presumed Gram-positive infections over a period of 12 months. Eighty-five patients were subsequently found to be evaluable; 31 had soft tissue infections, 10 endocarditis, 8 urinary tract infections, 12 septicaemias, 2 chest infections, 7 osteomyelitis or septic arthritis, and 15 were immunosuppressed patients with infected Hickman line site infections. The cure rate of the 85 evaluable episodes was 90% (76 cured). Teicoplanin was well tolerated intravenously and intramuscularly. Adverse reactions occurred in five patients. One patient suffered high tone hearing loss, two patients suffered transient rash, one developed a drug fever and one patient who had concomitant gentamicin developed vestibular damage. It is concluded that teicoplanin is a relatively safe and effacacious treatment for Gram-positive infection.

A new look at learning needs in general practice

Over a period of 18 months, trainees in the West Midlands were given a multiple choice questionnaire at the start of the general practice year to assess their factual knowledge in 14 areas of medicine and were given the opportunity to take the same test six months later. Sixty-five trainees who completed the test twice are the basis of the study, and their results are compared with 99 trainers who completed the paper once. In the pre-training test, the trainees' scores were significantly lower than their trainers' in total and in most individual subjects. In the mid-training test, the trainees' knowledge of most subjects had improved significantly over the six months. These results indicate that the teaching and assessment of factual knowledge should not be dismissed as unimportant in general practice training.

Nutrition of the Ewe and Embryo Growth during Early Pregnancy

Mature Merino ewes (n = 228) were fed rations at levels of either 5, 10, 15, 20, 30 or 40 g/kg daily from day 1 until day 35 after mating. Embryos were then removed from single ovulating ewes and, after being weighed and measured, were dissected and embryo liver weights were obtained. Plasma samples were taken from all ewes on days 5, 10, 15, 20, 27 and 35 after mating and later analysed for glucose concentrations.