Exploring the resilience of wheat crops grown in short rotations through minimising the build-up of an important soil-borne fungal pathogen.

Given the increasing demand for wheat which is forecast, cropping of wheat in short rotations will likely remain a common practice. However, in temperate wheat growing regions the soil-borne fungal pathogen Gaeumannomyces tritici becomes a major constraint on productivity. In cultivar rotation field experiments on the Rothamsted Farm (Hertfordshire, UK) we demonstrated a substantial reduction in take-all disease and grain yield increases of up to 2.4 tonnes/ha when a low take-all inoculum building wheat cultivar was grown in the first year of wheat cropping. Phenotyping of 71 modern elite wheat cultivars for the take-all inoculum build-up trait across six diverse trial sites identified a few cultivars which exhibited a consistent lowering of take-all inoculum build-up. However, there was also evidence of a significant interaction effect between trial site and cultivar when a pooled Residual Maximum Likelihood (REML) procedure was conducted. There was no evidence of an unusual rooting phenotype associated with take-all inoculum build-up in two independent field experiments and a sand column experiment. Together our results highlight the complex interactions between wheat genotype, environmental conditions and take-all inoculum build-up. Further work is required to determine the underlying genetic and mechanistic basis of this important phenomenon.

Take-all or nothing.

Take-all disease of Poaceae is caused by Gaeumannomyces graminis (Magnaporthaceae). Four varieties are recognised in G. graminis based on ascospore size, hyphopodial morphology and host preference. The aim of the present study was to clarify boundaries among species and varieties in Gaeumannomyces by combining morphology and multi-locus phylogenetic analyses based on partial gene sequences of ITS, LSU, tef1 and rpb1. Two new genera, Falciphoriella and Gaeumannomycella were subsequently introduced in Magnaporthaceae. The resulting phylogeny revealed several cryptic species previously overlooked within Gaeumannomyces. Isolates of Gaeumannomyces were distributed in four main clades, from which 19 species could be delimited, 12 of which were new to science. Our results show that the former varieties Gaeumannomyces graminis var. avenae and Gaeumannomyces graminis var. tritici represent species phylogenetically distinct from G. graminis, for which the new combinations G. avenae and G. tritici are introduced. Based on molecular data, morphology and host preferences, Gaeumannomyces graminis var. maydis is proposed as a synonym of G. radicicola. Furthermore, an epitype for Gaeumannomyces graminis var. avenae was designated to help stabilise the application of that name.

An analysis of Pseudomonas genomic diversity in take-all infected wheat fields reveals the lasting impact of wheat cultivars on the soil microbiota.

Manipulation of the soil microbiota associated with crop plants has huge promise for the control of crop pathogens. However, to fully realize this potential we need a better understanding of the relationship between the soil environment and the genes and phenotypes that enable microbes to colonize plants and contribute to biocontrol. A recent 2 years of investigation into the effect of wheat variety on second year crop yield in the context of take-all fungal infection presented the opportunity to examine soil microbiomes under closely defined field conditions. Amplicon sequencing of second year soil samples showed that Pseudomonas spp. were particularly affected by the wheat cultivar grown in year one. Consequently, 318 rhizosphere-associated Pseudomonas fluorescens strains were isolated and characterized across a variety of genetic and phenotypic traits. Again, the wheat variety grown in the first year of the study was shown to exert considerable selective pressure on both the extent and nature of Pseudomonas genomic diversity. Furthermore, multiple significant correlations were identified within the phenotypic/genetic structure of the Pseudomonas population, and between individual genotypes and the external wheat field environment. The approach outlined here has considerable future potential for our understanding of plant-microbe interactions, and for the broader analysis of complex microbial communities.

The health of somatic cell cloned cattle and their offspring.

The cloning syndrome is a continuum with the consequences of abnormal reprogramming manifest throughout gestation, the neo-natal period, and into adulthood in the cloned generation, but it does not appear to be transmitted to subsequent offspring following sexual reproduction. Most in vivo studies on bovine somatic cell cloning have focused on development during pregnancy and the neo-natal period. In this paper, we report on the viability and health of cloned cattle in adulthood. From our studies at AgResearch, we find that between weaning and 4 years of age, the annual mortality rate in cattle cloned from somatic cells is at least 8%. Although the reasons for death are variable and some potentially preventable, the main mortality factor in this period is euthanasia due to musculoskeletal abnormalities. This includes animals with severely contracted flexor tendons and those displaying chronic lameness, particularly in milking cows. In contrast, no deaths beyond weaning have so far been encountered with the offspring of clones where the oldest animals are 3 years of age. In surviving cloned cattle, blood profiles and other indicators of general physiological function such as growth rate, reproduction, rearing of offspring, and milk production are all within the normal phenotypic ranges.

Cloned cattle derived from a novel zona-free embryo reconstruction system.

As the demand for cloned embryos and offspring increases, the need arises for the development of nuclear transfer procedures that are improved in both efficiency and ease of operation. Here, we describe a novel zona-free cloning method that doubles the throughput in cloned bovine embryo production over current procedures and generates viable offspring with the same efficiency. Elements of the procedure include zona-free enucleation without a holding pipette, automated fusion of 5-10 oocyte-donor cell pairs and microdrop in vitro culture. Using this system, zona-free embryos were reconstructed from five independent primary cell lines and cultured either singularly (single-IVC) or as aggregates of three (triple-IVC). Blastocysts of transferable quality were obtained at similar rates from zona-free single-IVC, triple-IVC, and control zona-intact embryos (33%, 25%, and 29%, respectively). In a direct comparison, there was no significant difference in development to live calves at term between single-IVC, triple-IVC, and zona-intact embryos derived from the same adult fibroblast line (10%, 13%, and 15%, respectively). This zona-free cloning method could be straightforward for users of conventional cloning procedures to adopt and may prove a simple, fast, and efficient alternative for nuclear cloning of other species as well.

Corticosteroid-sparing effect of etanercept in idiopathic panuveitis resistant to immunosuppressive therapy.

Uveitis, an inflammatory eye disease with varying immunopathogenic mechanisms, may be associated with autoimmune disorders, may be secondary to infection, or may be idiopathic. Response to treatment of uveitis is inconsistent. In this report we describe an adult with idiopathic panuveitis who attempted to lower his oral corticosteroid dose from intolerable levels but was unable to do so because of the reappearance of symptoms. His 8-year course was managed with ocular and systemic corticosteroids, methotrexate, and cyclosporine, which allowed only partially successful control of his ocular inflammation. Complete control was not achieved until the addition of etanercept. With this case report we are the first to describe the complete response of idiopathic panuveitis to etanercept. Our success with this patient strongly supports the critical role of tumor necrosis factor in the immunopathogenesis of some cases of idiopathic panuveitis. Furthermore, etanercept offers a relatively nontoxic, safe option in cases of panuveitis that are unresponsive to traditional immunosuppressive therapy.

The effect of a nursing intervention on the incidence of older patient falls.

This paper describes the evaluation of a fall prevention protocol that combined the assessment of the mobility and confusion status of 2,023 patients aged 70 years and over and a toileting regimen for at risk patients who were both confused and having mobility problems. The six months' study was conducted in a 450 bed metropolitan teaching hospital and involved approximately 500 nursing staff in the hospital's medical and surgical wards. Almost five percent (4.7%) of patients in the study group fell; 13 patients fell more than once and the total number of falls was 112. Twenty-four percent of patients (n = 482) were assessed as being at risk of falling and 54% of falls (n = 61) occurred in the at risk group. Sixteen percent of these falls occurred in the sub-group who had been toileted according to the study protocol and 84% in the sub-group who had not been toileted according to the protocol. There were 53% fewer patient falls during shifts which complied with both the assessment and toileting protocol than during non-compliant shifts. Given the simplicity and effectiveness of the study protocol, the finding that it was not followed on 43% of shifts is of concern.

Optic neuropathy and central nervous system disease associated with primary Sjögren's syndrome.

Three cases of optic neuropathy associated with primary Sjögren's syndrome are reported. All three patients had clinical manifestations of primary Sjögren's syndrome, although two of the patients did not report sicca symptoms at initial examination. Two patients had focal neurologic signs in addition to optic neuropathy. The differentiation of this syndrome of optic neuropathy, focal neurologic signs, and Sjögren's syndrome from multiple sclerosis and antiphospholipid antibody syndrome is important for reasons of treatment and prognosis. This diagnostic differentiation was facilitated by positive tests for xerophthalmia and findings of positive minor salivary gland biopsy. High titers of antinuclear antibody, anti-SSA(Ro), and anti-SSB(La), and the absence of antiphospholipid antibodies provided additional help in the differential diagnosis. In 5 years of observation, none of the patients developed symptoms of multiple sclerosis or additional connective tissue disorders.

Endogenous endophthalmitis due to Salmonella arizonae and Hafnia alvei.

Enteric pathogens rarely involve organs other than those of the gastrointestinal system. We have reported the case of a woman with rheumatoid arthritis who had endogenous endophthalmitis due to Salmonella arizonae and Hafnia alvei. The infection probably resulted from the use of snake powder as a food seasoner. After appropriate intravenous, intraocular, subconjunctival, topical, and oral antibiotic therapy based on laboratory susceptibility studies, the patient's condition clinically improved, but complications resulted in therapeutic enucleation. Because of the ubiquitous nature of these and other potentially pathogenic organisms, great care must be taken in evaluation, management, and education of immunocompromised patients.

Corticosteroid induction of Ig+Ia- B cells in vitro is mediated via interaction with the glucocorticoid cytoplasmic receptor.

Flow microfluorometry was used to examine the effect of dexamethasone on the expression of surface Ia (sIa) on resting and activated murine B cells. Although dexamethasone resulted in a 50% reduction in sIa expression 12 h after injection, it was significantly less suppressive when injected together with B cell activators. In vitro dexamethasone, but not other related steroid hormones, induced a population of cells that were sIg+sIa-. A 20% reduction in the expression of sIa was noted by 4 h of culture with 10 nM dexamethasone, but maximal inhibition of 70% was not reached until 12 h of culture, and this degree of suppression persisted as long as dexamethasone remained in culture. When the dexamethasone was washed out after 8 h of culture, the maximal reduction was still noted at 12 h, but by 24 h there was re-expression of sIa toward base line levels, indicating it did not induce irreversible lethal alterations in the B cell. The inhibition of sIa expression correlated with a specific reduction in the quantity of messenger RNA for sIa as measured by Northern blot analysis, indicating that this is mediated at least in part by suppression of the steady state levels of Ia mRNA. The corticosteroid receptor antagonist RU486 was able to reverse the suppressive effects of dexamethasone on sIa expression, thus demonstrating that its effect is mediated specifically by binding to its intracellular receptor. Furthermore, when protein synthesis was inhibited during the short period of time that cells were preincubated with dexamethasone, minimal suppression of Ia expression was noted, suggesting that the dexamethasone may be stimulating a protein that has suppressive effects on MHC class II expression. The suppressive effects of dexamethasone in vitro were substantially reduced when B cells were simultaneously activated by stimuli that increase the expression of sIa. These data indicate that the suppressive effects of corticosteroids on immune response Ag are corticosteroid specific; are greater in resting than in activated B cells; are induced via the classical steroid mechanism of action, which is receptor mediated; and may result from the induction of an inhibitory protein that suppresses Ia mRNA.

Glucocorticoids suppress calcium mobilization and phospholipid hydrolysis in anti-Ig antibody-stimulated B cells.

Glucocorticoids have been shown to play a major role in influencing the activation of B lymphocytes. In view of our recent observation that dexamethasone exerts a marked suppressive effect on an early event in B cell activation that is stimulated by anti-Ig antibody, we investigated its activity on other stimuli that induce intracellular events similar to those produced by anti-Ig antibody. Because the intracellular events that occur after B cell stimulation with phorbol myristate acetate and the calcium ionophore A23187 appear to mimic those that occur after B cell stimulation with anti-Ig antibody, we studied whether the cellular responses elicited by these activation stimuli are affected in a similar fashion by dexamethasone. Whereas anti-Ig antibody-stimulated entry of G0 B cells to the G1 and S phase of the cell cycle was markedly suppressed by dexamethasone, phorbol myristate acetate/A23187 stimulation of these events was resistant to dexamethasone. Our finding that anti-Ig-induced cross-linking of B cell surface Ig, as measured by surface Ig capping, was not inhibited by dexamethasone suggested that corticosteroids inhibit anti-Ig-induced B cell proliferation at a step distal to membrane Ig cross-linking and proximal to phosphatidylinositol bisphosphate hydrolysis. This hypothesis is supported by experiments presented in this manuscript which demonstrate that dexamethasone inhibits anti-Ig-stimulated phosphatidylinositol bisphosphate hydrolysis. We also found that dexamethasone markedly inhibited anti-Ig antibody-stimulated increases in intracellular ionized calcium concentrations. This dexamethasone-mediated suppression is time-dependent as it is not seen when B cells are cultured with dexamethasone for less than 6 hr. Our data suggest that the immunomodulatory activity of glucocorticoids is exerted by binding to its nuclear receptor, thereby preventing the generation of second messengers required for cell activation after agonist-receptor interaction.

Comparison of the calcium requirement for the induction and maintenance of B cell class II molecule expression and for B cell proliferation stimulated by mitogens and purified growth factors.

As an important intracellular second-messenger, the concentration of calcium in the cytosol [Ca+2]i influences diverse cellular activities. To investigate the calcium requirement for distinct phases of B cell activation, we studied the effect of altering the quantity of extracellular calcium on the induction of increased B cell MHC class II molecule (Ia) expression and DNA synthesis by different B cell mitogens. During short-term cultures (less than 24 hr), the induction of class II molecules by anti-immunoglobulin (anti-Ig) and calcium ionophore were dependent on the presence of extracellular calcium, whereas activation induced by B cell stimulation factor-1 (BSF-1) was minimally dependent on extracellular calcium, and that induced by LPS was independent of it. During longer-term cultures (i.e., greater than 24 hr), the heightened class II molecule expression that was induced by all of the B cell mitogens used was significantly compromised by depletion of extracellular free calcium. Although the anti-Ig-stimulated increase in expression of Ia could be restored by the addition of calcium to the medium at 12 hr, it could not be restored when the addition of calcium was delayed to 24 hr after the onset of culture. This was in marked contrast to the finding that BSF-1-stimulated B cell responses which were suppressed after 24 hr of culture in the presence of EGTA could be restored by the addition of calcium. Activation of B cells along the pathway leading to DNA synthesis demonstrated a requirement for extracellular calcium which was greater than that required for induction of MHC class II molecule expression. Thus, LPS-stimulated size increases of B cells after 12 hr of culture was dependent on extracellular calcium while its induction of MHC class II molecule expression was independent of extracellular calcium at this early time point. These observations indicate that the extracellular calcium requirement for B cell activation is dependent both on the activation pathway utilized by the mitogenic signal and on the duration of cell activation. Furthermore, they demonstrate that B cell stimuli that can initiate B cell activation in the relative absence of extracellular calcium may require extracellular calcium for maintenance of this activational state.

Outcome of patients committed to hospital under the Mental Health (Scotland) Act 1960.

All patients formally detained in a Scottish psychiatric hospital between 1974 and 1979 were identified and their outcome determined 2 1/2-8 1/2 years later. A matched group, detained under Emergency Orders only, were also followed-up. Those formally detained had more previous psychiatric contact: functional psychoses were significantly more common in them. They remained in hospital longer, and required extensive community support when discharged. Those detained under Emergency Orders only, consisted of two sub-groups--one who left the area within two years of admission and could not be traced, and the remainder, who continued to require hospital treatment but for shorter times and with less continuous support. Amongst those detained, lack of insight was a predominant feature, which may create difficulty with regard to informed consent to treatment, given the present Amendments to the Mental Health Acts.

Renal failure with minimal change nephrotic syndrome: reversal with hemodialysis.

A patient with acute renal failure accompanying nephrotic syndrome associated with minimal change nephropathy acutely reversed with hemodialysis and ultrafiltration. This response is felt to support the interstitial edema tubular obstruction theory of renal failure occurring with minimal change disease. Acute hemodialysis with significant fluid removal may dramatically reverse severe degrees of azotemia in this condition independent of corticosteroid therapy. The latter, however, may be necessary for remission of the nephrotic syndrome.