Performance demonstration of vacuum microwave components critical for the operation of the ITER low-field side reflectometer

Final design studies in preparation for manufacturing have been performed for functional components of the vacuum portion of the ITER Low-Field Side Reflectometer (LFSR). These components consist of an antenna array, electron cyclotron heating (ECH) protection mirrors, phase calibration mirrors, and vacuum windows. Evaluation of these components was conducted at the LFSR test facility and DIII-D. The antenna array consists of six corrugated-waveguide antennas for simultaneous profile, fluctuation, and Doppler measurements. A diffraction grating, incorporated into the plasma-facing miter bend, provides protection of sensitive components from stray ECH at 170 GHz. For in situ phase calibration of the LFSR profile reflectometer, an embossed mirror is incorporated into the adjacent miter bend. Measurements of the radiated beam profile indicate that these components have a small, acceptable effect on mode conversion and beam quality. Baseline transmission characteristics of the dual-disk vacuum window are obtained and are used to guide ongoing developments. Preliminary simulations indicate that a surface-relief structure on the window surfaces can greatly improve transmission. The workability of real-time phase measurements was demonstrated on the DIII-D profile reflectometer. The new automated real-time analysis agrees well with the standard post-processing routine.

Foliar resistance to Rhizoctonia solani in Arabidopsis is compromised by simultaneous loss of ethylene, jasmonate and PEN2 mediated defense pathways

Rhizoctonia solani causes damaging yield losses on most major food crops. R. solani isolates belonging to anastomosis group 8 (AG8) are soil-borne, root-infecting pathogens with a broad host range. AG8 isolates can cause disease on wheat, canola and legumes, however Arabidopsis thaliana is heretofore thought to possess non-host resistance as A. thaliana ecotypes, including the reference strain Col-0, are resistant to AG8 infection. Using a mitochondria-targeted redox sensor (mt-roGFP2) and cell death staining, we demonstrate that both AG8 and a host isolate (AG2-1) of R. solani are able to infect A. thaliana roots. Above ground tissue of A. thaliana was found to be resistant to AG8 but not AG2. Genetic analysis revealed that ethylene, jasmonate and PENETRATION2-mediated defense pathways work together to provide resistance to AG8 in the leaves which subsequently enable tolerance of root infections. Overall, we demonstrate a significant difference in defense capabilities of above and below ground tissue in providing resistance to R. solani AG8 in Arabidopsis.

Comparative secretome analysis of Rhizoctonia solani isolates with different host ranges reveals unique secretomes and cell death inducing effectors

Rhizoctonia solani is a fungal pathogen causing substantial damage to many of the worlds’ largest food crops including wheat, rice, maize and soybean. Despite impacting global food security, little is known about the pathogenicity mechanisms employed by R. solani. To enable prediction of effectors possessing either broad efficacy or host specificity, a combined secretome was constructed from a monocot specific isolate, a dicot specific isolate and broad host range isolate infecting both monocot and dicot hosts. Secretome analysis suggested R. solani employs largely different virulence mechanisms to well-studied pathogens, despite in many instances infecting the same host plants. Furthermore, the secretome of the broad host range AG8 isolate may be shaped by maintaining functions for saprophytic life stages while minimising opportunities for host plant recognition. Analysis of possible co-evolution with host plants and in-planta up-regulation in particular, aided identification of effectors including xylanase and inhibitor I9 domain containing proteins able to induce cell death in-planta. The inhibitor I9 domain was more abundant in the secretomes of a wide range of necrotising fungi relative to biotrophs. These findings provide novel targets for further dissection of the virulence mechanisms and potential avenues to control this under-characterised but important pathogen.

Ethylene Signaling Is Important for Isoflavonoid-Mediated Resistance to Rhizoctonia solani in Roots of Medicago truncatula

The root-infecting necrotrophic fungal pathogen Rhizoctoniasolani causes significant disease to all the world's major food crops. As a model for pathogenesis of legumes, we have examined the interaction of R. solani AG8 with Medicago truncatula. RNAseq analysis of the moderately resistant M. truncatula accession A17 and highly susceptible sickle (skl) mutant (defective in ethylene sensing) identified major early transcriptional reprogramming in A17. Responses specific to A17 included components of ethylene signaling, reactive oxygen species metabolism, and consistent upregulation of the isoflavonoid biosynthesis pathway. Mass spectrometry revealed accumulation of the isoflavonoid-related compounds liquiritigenin, formononetin, medicarpin, and biochanin A in A17. Overexpression of an isoflavone synthase in M. truncatula roots increased isoflavonoid accumulation and resistance to R. solani. Addition of exogenous medicarpin suggested this phytoalexin may be one of several isoflavonoids required to contribute to resistance to R. solani. Together, these results provide evidence for the role of ethylene-mediated accumulation of isoflavonoids during defense against root pathogens in legumes. The involvement of ethylene signaling and isoflavonoids in the regulation of both symbiont-legume and pathogen-legume interactions in the same tissue may suggest tight regulation of these responses are required in the root tissue.

Mass-spectrometry data for Rhizoctonia solani proteins produced during infection of wheat and vegetative growth

Rhizoctonia solani is an important root infecting pathogen of a range of food staples worldwide including wheat, rice, maize, soybean, potato, legumes and others. Conventional resistance breeding strategies are hindered by the absence of tractable genetic resistance in any crop host. Understanding the biology and pathogenicity mechanisms of this fungus is important for addressing these disease issues, however, little is known about how R. solani causes disease. The data described in this article is derived from applying mass spectrometry based proteomics to identify soluble, membrane-bound and culture filtrate proteins produced under wheat infection and vegetative growth conditions. Comparisons of the data for sample types in this set will be useful to identify metabolic pathway changes as the fungus switches from saprophytic to a pathogenic lifestyle or pathogenicity related proteins contributing to the ability to cause disease on wheat. The data set is deposited in the PRIDE archive under identifier PRIDE: PXD002806.

Reactive Oxygen Species Play a Role in the Infection of the Necrotrophic Fungi, Rhizoctonia solani in Wheat

Rhizoctonia solani is a nectrotrophic fungal pathogen that causes billions of dollars of damage to agriculture worldwide and infects a broad host range including wheat, rice, potato and legumes. In this study we identify wheat genes that are differentially expressed in response to the R. solani isolate, AG8, using microarray technology. A significant number of wheat genes identified in this screen were involved in reactive oxygen species (ROS) production and redox regulation. Levels of ROS species were increased in wheat root tissue following R. solani infection as determined by Nitro Blue Tetrazolium (NBT), 3,3'-diaminobenzidine (DAB) and titanium sulphate measurements. Pathogen/ROS related genes from R. solani were also tested for expression patterns upon wheat infection. TmpL, a R. solani gene homologous to a gene associated with ROS regulation in Alternaria brassicicola, and OAH, a R. solani gene homologous to oxaloacetate acetylhydrolase which has been shown to produce oxalic acid in Sclerotinia sclerotiorum, were highly induced in R. solani when infecting wheat. We speculate that the interplay between the wheat and R. solani ROS generating proteins may be important for determining the outcome of the wheat/R. solani interaction.

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.

Proteomic Analysis of Rhizoctonia solani Identifies Infection-specific, Redox Associated Proteins and Insight into Adaptation to Different Plant Hosts

Rhizoctonia solani is an important root infecting pathogen of a range of food staples worldwide including wheat, rice, maize, soybean, potato and others. Conventional resistance breeding strategies are hindered by the absence of tractable genetic resistance in any crop host. Understanding the biology and pathogenicity mechanisms of this fungus is important for addressing these disease issues, however, little is known about how R. solani causes disease. This study capitalizes on recent genomic studies by applying mass spectrometry based proteomics to identify soluble, membrane-bound and culture filtrate proteins produced under wheat infection and vegetative growth conditions. Many of the proteins found in the culture filtrate had predicted functions relating to modification of the plant cell wall, a major activity required for pathogenesis on the plant host, including a number found only under infection conditions. Other infection related proteins included a high proportion of proteins with redox associated functions and many novel proteins without functional classification. The majority of infection only proteins tested were confirmed to show transcript up-regulation during infection including a thaumatin which increased susceptibility to R. solani when expressed in Nicotiana benthamiana. In addition, analysis of expression during infection of different plant hosts highlighted how the infection strategy of this broad host range pathogen can be adapted to the particular host being encountered. Data are available via ProteomeXchange with identifier PXD002806.

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.

Suppression of the auxin response pathway enhances susceptibility to Phytophthora cinnamomi while phosphite-mediated resistance stimulates the auxin signalling pathway

BACKGROUND

Phytophthora cinnamomi is a devastating pathogen worldwide and phosphite (Phi), an analogue of phosphate (Pi) is highly effective in the control of this pathogen. Phi also interferes with Pi starvation responses (PSR), of which auxin signalling is an integral component. In the current study, the involvement of Pi and the auxin signalling pathways in host and Phi-mediated resistance to P. cinnamomi was investigated by screening the Arabidopsis thaliana ecotype Col-0 and several mutants defective in PSR and the auxin response pathway for their susceptibility to this pathogen. The response to Phi treatment was also studied by monitoring its effect on Pi- and the auxin response pathways.

RESULTS

Here we demonstrate that phr1-1 (phosphate starvation response 1), a mutant defective in response to Pi starvation was highly susceptible to P. cinnamomi compared to the parental background Col-0. Furthermore, the analysis of the Arabidopsis tir1-1 (transport inhibitor response 1) mutant, deficient in the auxin-stimulated SCF (Skp1 - Cullin - F-Box) ubiquitination pathway was also highly susceptible to P. cinnamomi and the susceptibility of the mutants rpn10 and pbe1 further supported a role for the 26S proteasome in resistance to P. cinnamomi. The role of auxin was also supported by a significant (P < 0.001) increase in susceptibility of blue lupin (Lupinus angustifolius) to P. cinnamomi following treatment with the inhibitor of auxin transport, TIBA (2,3,5-triiodobenzoic acid). Given the apparent involvement of auxin and PSR signalling in the resistance to P. cinnamomi, the possible involvement of these pathways in Phi mediated resistance was also investigated. Phi (especially at high concentrations) attenuates the response of some Pi starvation inducible genes such as AT4, AtACP5 and AtPT2 in Pi starved plants. However, Phi enhanced the transcript levels of PHR1 and the auxin responsive genes (AUX1, AXR1and AXR2), suppressed the primary root elongation, and increased root hair formation in plants with sufficient Pi.

CONCLUSIONS

The auxin response pathway, particularly auxin sensitivity and transport, plays an important role in resistance to P. cinnamomi in Arabidopsis, and phosphite-mediated resistance may in some part be through its effect on the stimulation of the PSR and auxin response pathways.

In vivo modulation of polo-like kinases supports a key role for PLK2 in Ser129 α-synuclein phosphorylation in mouse brain

α-Synuclein is the major component of Lewy bodies. α-Synuclein phosphorylated at Ser 129 (Phospho-α-Syn) is the most common synuclein modification observed in Parkinson's disease pathology and transgenic animal models. Polo-like kinase 2 (PLK2) was previously proposed as an important kinase in α-synuclein phosphorylation at Ser129. To better understand the role of PLK2 in α-synuclein phosphorylation in vivo, we further evaluated the effect of PLK2 genetic knockdown and pharmacological inhibition on Phospho-α-Syn levels in different brain regions of PLK2 knockout (KO), heterozygous (Het) and wild-type (WT) mice. Whereas PLK2 knockdown had no effect on Total-α-synuclein brain levels, it resulted in a gene-dosage dependent, albeit incomplete, reduction of endogenous Phospho-α-Syn levels in all brain regions investigated. No compensatory induction of other α-synuclein kinases (PLK3, casein kinase-2, G-protein-coupled receptor kinase 5 (GRK5) and GRK6) was observed at the mRNA level in the PLK2 KO mouse brain. To determine whether increased activity of another PLK family member is responsible for the residual Phospho-α-Syn levels in the PLK2 KO mouse brain, the pan-PLK inhibitor BI 2536 was tested in PLK2 KO mice. Whereas BI 2536 reduced Phospho-α-Syn levels in WT mice, it did not further reduce the residual endogenous Phospho-α-Syn levels in PLK2 KO and Het mice, suggesting that a kinase other than PLK1-3 accounts for the remaining PLK inhibitor-resistant pool in the mouse brain. Moreover, PLK3 KO in mice had no effect on both Total- and Phospho-α-Syn brain levels. These results support a significant role for a PLK kinase in phosphorylating α-synuclein at Ser129 in the brain, and suggest that PLK2 is responsible for this activity under physiological conditions.

The operative correction of symptomatic flat foot deformities in children: the relationship between static alignment and dynamic loading

At our institution surgical correction of symptomatic flat foot deformities in children has been guided by a paradigm in which radiographs and pedobarography are used in the assessment of outcome following treatment. Retrospective review of children with symptomatic flat feet who had undergone surgical correction was performed to assess the outcome and establish the relationship between the static alignment and the dynamic loading of the foot. A total of 17 children (21 feet) were assessed before and after correction of soft-tissue contractures and lateral column lengthening, using standardised radiological and pedobarographic techniques for which normative data were available. We found significantly improved static segmental alignment of the foot, significantly improved mediolateral dimension foot loading, and worsened fore-aft foot loading, following surgical treatment. Only four significant associations were found between radiological measures of static segmental alignment and dynamic loading of the foot. Weakness of the plantar flexors of the ankle was a common post-operative finding. Surgeons should be judicious in the magnitude of lengthening of the plantar flexors that is undertaken and use techniques that minimise subsequent weakening of this muscle group.

Genetic and genomic analysis of Rhizoctonia solani interactions with Arabidopsis; evidence of resistance mediated through NADPH oxidases

Rhizoctonia solani is an important soil-borne necrotrophic fungal pathogen, with a broad host range and little effective resistance in crop plants. Arabidopsis is resistant to R. solani AG8 but susceptible to R. solani AG2-1. A screen of 36 Arabidopsis ecotypes and mutants affected in the auxin, camalexin, salicylic acid, abscisic acid and ethylene/jasmonic acid pathways did not reveal any variation in response to R. solani and demonstrated that resistance to AG8 was independent of these defense pathways. The Arabidopsis Affymetrix ATH1 Genome array was used to assess global gene expression changes in plants infected with AG8 and AG2-1 at seven days post-infection. While there was considerable overlap in the response, some gene families were differentially affected by AG8 or AG2-1 and included those involved in oxidative stress, cell wall associated proteins, transcription factors and heat shock protein genes. Since a substantial proportion of the gene expression changes were associated with oxidative stress responses, we analysed the role of NADPH oxidases in resistance. While single NADPH oxidase mutants had no effect, a NADPH oxidase double mutant atrbohf atrbohd resulted in an almost complete loss of resistance to AG8, suggesting that reactive oxidative species play an important role in Arabidopsis's resistance to R. solani.

Interactions of Arabidopsis and M. truncatula with the same pathogens differ in dependence on ethylene and ethylene response factors

Microbial pathogens inflict large losses to agriculture annually and thus mechanisms of plant resistance and how to deploy them to enhance disease resistance in crops are foci of much research interest. We recently described the important role of ethylene and Ethylene Response transcription Factors (ERFs), particularly MtERF1-1, in mediating resistance to the fungal pathogen Rhizoctonia solani in the model legume, Medicago truncatula. Previous studies on the closely related AtERF14, a master regulator of ethylene dependent defenses including other ERFs, suggested that in Arabidopsis these defenses were not essential for resistance to the same R. solani isolate but were required for resistance to another fungal pathogen, Fusarium oxysporum. Medicago plants with roots over-expressing MtERF1-1 were challenged with F. oxysporum but showed no altered resistance. These results further support a potential for divergent roles of ethylene associated defenses in different plant hosts responding to the same pathogen.

The B-3 ethylene response factor MtERF1-1 mediates resistance to a subset of root pathogens in Medicago truncatula without adversely affecting symbiosis with rhizobia

The fungal necrotrophic pathogen Rhizoctonia solani is a significant constraint to a range of crops as diverse as cereals, canola, and legumes. Despite wide-ranging germplasm screens in many of these crops, no strong genetic resistance has been identified, suggesting that alternative strategies to improve resistance are required. In this study, we characterize moderate resistance to R. solani anastomosis group 8 identified in Medicago truncatula. The activity of the ethylene- and jasmonate-responsive GCC box promoter element was associated with moderate resistance, as was the induction of the B-3 subgroup of ethylene response transcription factors (ERFs). Genes of the B-1 subgroup showed no significant response to R. solani infection. Overexpression of a B-3 ERF, MtERF1-1, in Medicago roots increased resistance to R. solani as well as an oomycete root pathogen, Phytophthora medicaginis, but not root knot nematode. These results indicate that targeting specific regulators of ethylene defense may enhance resistance to an important subset of root pathogens. We also demonstrate that overexpression of MtERF1-1 enhances disease resistance without apparent impact on nodulation in the A17 background, while overexpression in sickle reduced the hypernodulation phenotype. This suggests that under normal regulation of nodulation, enhanced resistance to root diseases can be uncoupled from symbiotic plant-microbe interactions in the same tissue and that ethylene/ERF regulation of nodule number is distinct from the defenses regulated by B-3 ERFs. Furthermore, unlike the stunted phenotype previously described for Arabidopsis (Arabidopsis thaliana) ubiquitously overexpressing B-3 ERFs, overexpression of MtERF1-1 in M. truncatula roots did not show adverse effects on plant development.

Plants versus pathogens: an evolutionary arms race

The analysis of plant-pathogen interactions is a rapidly moving research field and one that is very important for productive agricultural systems. The focus of this review is on the evolution of plant defence responses and the coevolution of their pathogens, primarily from a molecular-genetic perspective. It explores the evolution of the major types of plant defence responses including pathogen associated molecular patterns and effector triggered immunity as well as the forces driving pathogen evolution, such as the mechanisms by which pathogen lineages and species evolve. Advances in our understanding of plant defence signalling, stomatal regulation, R gene-effector interactions and host specific toxins are used to highlight recent insights into the coevolutionary arms race between pathogens and plants. Finally, the review considers the intriguing question of how plants have evolved the ability to distinguish friends such as rhizobia and mycorrhiza from their many foes.

Initial description of the human NLRP3 promoter

Mutations in NLRP3 (CIAS1) are identified in a continuum of related inflammatory disorders, known as cryopyrinopathies since NLRP3 codes for the protein cryopyrin. Approximately 40% of patients with classic presentation lack mutations in the coding region of NLRP3 suggesting heterogeneity or epigenetic factors. Cryopyrin is a key regulator of proinflammatory cytokine release. Therefore, variations in the NLRP3 promoter sequence may have effects on disease state in patients with cryopyrinopathies and other inflammatory diseases. In this report, we confirmed three 5'-untranslated region splice forms with two separate transcriptional start sites, and identified potential promoter regions and six new DNA promoter variants. One variant is unique to a mutation negative cryopyrinopathy patient and increases in vitro gene expression. Additional studies can now be performed to further characterize the NLRP3 promoter and sequence variants, which will lead to better understanding of the regulation of NLRP3 expression and its role in disease.

Evaluation of the validity of the Quality of Well-being Scale in Trinidad and Tobago

Both developing countries in the Caribbean and developed countries face resource allocation challenges. However, cost-effectiveness analysis instruments that may assist in allocation of resources have not been tested in Caribbean countries. Trinidad and Tobago is an advantageous location to test an instrument for potential use in the Caribbean. It has a single payer healthcare system and a literate population. Due to historical and current migration from other Caribbean countries, the population might be a fair representation of English-speaking Caribbean nations. We tested the validity of the Quality of Well-being Scale (QWB) on a sample of the non-institutionalized general population in Trinidad. The survey included reports of chronic conditions and items from the Trinidad and Tobago National Health Interview Survey. Data were analyzed using a multivariable regression model. One adult from each of 235 households consented to the interview. The results are consistent with results obtained in the United States of America. Being older female, more chronic conditions and more symptoms/problems were significantly associated with lower mean QWB scores. These results suggest that the QWB with US-derived weights show evidence of validity in Trinidad and Tobago. Thus, health decision makers can use the QWB to compare the effects of different health conditions and health interventions. In addition, investigators can make cross-cultural comparisons of QWB scores for diseases or health conditions.

Characterization of pea aphid resistance in Medicago truncatula

To achieve a thorough understanding of plant-aphid interactions, it is necessary to investigate in detail both the plant and insect side of the interaction. The pea aphid (PA; Acyrthosiphon pisum) has been selected by an international consortium as the model species for genetics and genomics studies, and the model legume Medicago truncatula is a host of this aphid. In this study, we identified resistance to PA in a M. truncatula line, 'Jester', with well-characterized resistance to a closely related aphid, the bluegreen aphid (BGA; Acyrthosiphon kondoi). The biology of resistance to the two aphid species shared similarity, with resistance in both cases occurring at the level of the phloem, requiring an intact plant and involving a combination of antixenosis, antibiosis, and plant tolerance. In addition, PA resistance cosegregated in 'Jester' with a single dominant gene for BGA resistance. These results raised the possibility that both resistances may be mediated by the same mechanism. This was not supported by the results of gene induction studies, and resistance induced by BGA had no effect on PA feeding. Moreover, different genetic backgrounds containing a BGA resistance gene from the same resistance donor differ in resistance to PA. These results suggest that distinct mechanisms are involved in resistance to these two aphid species. Resistance to PA and BGA in the same genetic background in M. truncatula makes this plant an attractive model for the study of both plant and aphid components of resistant and susceptible plant-aphid interactions.

Involvement of the octadecanoid pathway in bluegreen aphid resistance in Medicago truncatula

Aphids are major insect pests of plants that feed directly from the phloem. We used the model legume Medicago truncatula Gaert. (barrel medic) to elucidate host resistance to aphids and identified a single dominant gene which confers resistance to Acyrthosiphon kondoi Shinji (bluegreen aphid). To understand how this gene conditions resistance to bluegreen aphid, transcription profiling of 23 defense-related genes representing various signaling pathways was undertaken using a pair of near-isogenic lines that are susceptible or resistant to bluegreen aphid. All salicylic acid- and ethylene-responsive genes tested were induced by bluegreen aphid in resistant and susceptible plants, although there were some differences in the magnitude and kinetics of the induction. In contrast, 10 of 13 genes associated with the octadecanoid pathway were induced exclusively in the resistant plants following bluegreen aphid infestation. These results are in contrast to plant-pathogen interactions where similar sets of defense genes typically are induced in compatible interactions, but to a lesser degree and later than in incompatible interactions. Treatment of susceptible plants with methyl jasmonate reduced bluegreen aphid infestation but not to the same levels as the resistant line. Together, these results strongly suggest that the octadecanoid pathway is important for this naturally derived aphid resistance trait.

AtERF14, a member of the ERF family of transcription factors, plays a nonredundant role in plant defense

We had previously shown that several transcription factors of the ethylene (ET) response factor (ERF) family were induced with different but overlapping kinetics following challenge of Arabidopsis (Arabidopsis thaliana) with Pseudomonas syringae pv tomato DC3000 (avrRpt2). One of these genes, a transcriptional activator, AtERF14, was induced at the same time as ERF-target genes (ChiB, basic chitinase). To unravel the potential function of AtERF14 in regulating the plant defense response, we have analyzed gain- and loss-of-function mutants. We show here that AtERF14 has a prominent role in the plant defense response, since overexpression of AtERF14 had dramatic effects on both plant phenotype and defense gene expression and AtERF14 loss-of-function mutants showed impaired induction of defense genes following exogenous ET treatment and increased susceptibility to Fusarium oxysporum. Moreover, the expression of other ERF genes involved in defense and ET/jasmonic acid responses, such as ERF1 and AtERF2, depends on AtERF14 expression. A number of ERFs have been shown to function in the defense response through overexpression. However, the effect of loss of AtERF14 function on defense gene expression, pathogen resistance, and regulation of the expression of other ERF genes is unique thus far. These results suggest a unique role for AtERF14 in regulating the plant defense response.

Plant defence responses: conservation between models and crops

Diseases of plants are a major problem for agriculture world wide. Understanding the mechanisms employed by plants to defend themselves against pathogens may lead to novel strategies to enhance disease resistance in crop plants. Much of the research in this area has been conducted with Arabidopsis as a model system, and this review focuses on how relevant the knowledge generated from this model system will be for increasing resistance in crop plants. In addition, the progress made using other model plant species is discussed. While there appears to be substantial similarity between the defence responses of Arabidopsis and other plants, there are also areas where significant differences are evident. For this reason it is also necessary to increase our understanding of the specific aspects of the defence response that cannot be studied using Arabidopsis as a model.

Plant defence responses: what have we learnt from Arabidopsis?

To overcome the attack of invading pathogens, a plant's defence system relies on preformed and induced responses. The induced responses are activated following detection of a pathogen, with the subsequent transmission of signals and orchestrated cellular events aimed at eliminating the pathogen and preventing its spread. Numerous studies are proving that the activated signalling pathways are not simply linear, but rather, form complex networks where considerable cross talk takes place. This review covers the recent application of powerful genetic and genomic approaches to identify key defence signalling pathways in the model plant Arabidopsis thaliana (L.) Heynh. The identification of key regulatory components of these pathways may offer new approaches to increase the defence capabilities of crop plants.

Antagonistic interaction between abscisic acid and jasmonate-ethylene signaling pathways modulates defense gene expression and disease resistance in Arabidopsis

The plant hormones abscisic acid (ABA), jasmonic acid (JA), and ethylene are involved in diverse plant processes, including the regulation of gene expression during adaptive responses to abiotic and biotic stresses. Previously, ABA has been implicated in enhancing disease susceptibility in various plant species, but currently very little is known about the molecular mechanisms underlying this phenomenon. In this study, we obtained evidence that a complex interplay between ABA and JA-ethylene signaling pathways regulate plant defense gene expression and disease resistance. First, we showed that exogenous ABA suppressed both basal and JA-ethylene-activated transcription from defense genes. By contrast, ABA deficiency as conditioned by the mutations in the ABA1 and ABA2 genes, which encode enzymes involved in ABA biosynthesis, resulted in upregulation of basal and induced transcription from JA-ethylene responsive defense genes. Second, we found that disruption of AtMYC2 (allelic to JASMONATE INSENSITIVE1 [JIN1]), encoding a basic helix-loop-helix Leu zipper transcription factor, which is a positive regulator of ABA signaling, results in elevated levels of basal and activated transcription from JA-ethylene responsive defense genes. Furthermore, the jin1/myc2 and aba2-1 mutants showed increased resistance to the necrotrophic fungal pathogen Fusarium oxysporum. Finally, using ethylene and ABA signaling mutants, we showed that interaction between ABA and ethylene signaling is mutually antagonistic in vegetative tissues. Collectively, our results indicate that the antagonistic interactions between multiple components of ABA and the JA-ethylene signaling pathways modulate defense and stress responsive gene expression in response to biotic and abiotic stresses.

Pathogen-responsive expression of a putative ATP-binding cassette transporter gene conferring resistance to the diterpenoid sclareol is regulated by multiple defense signaling pathways in Arabidopsis

The ATP-binding cassette (ABC) transporters are encoded by large gene families in plants. Although these proteins are potentially involved in a number of diverse plant processes, currently, very little is known about their actual functions. In this paper, through a cDNA microarray screening of anonymous cDNA clones from a subtractive library, we identified an Arabidopsis gene (AtPDR12) putatively encoding a member of the pleiotropic drug resistance (PDR) subfamily of ABC transporters. AtPDR12 displayed distinct induction profiles after inoculation of plants with compatible and incompatible fungal pathogens and treatments with salicylic acid, ethylene, or methyl jasmonate. Analysis of AtPDR12 expression in a number of Arabidopsis defense signaling mutants further revealed that salicylic acid accumulation, NPR1 function, and sensitivity to jasmonates and ethylene were all required for pathogen-responsive expression of AtPDR12. Germination assays using seeds from an AtPDR12 insertion line in the presence of sclareol resulted in lower germination rates and much stronger inhibition of root elongation in the AtPDR12 insertion line than in wild-type plants. These results suggest that AtPDR12 may be functionally related to the previously identified ABC transporters SpTUR2 and NpABC1, which transport sclareol. Our data also point to a potential role for terpenoids in the Arabidopsis defensive armory.

Systemic gene expression in Arabidopsis during an incompatible interaction with Alternaria brassicicola

Pathogen challenge can trigger an integrated set of signal transduction pathways, which ultimately leads to a state of "high alert," otherwise known as systemic or induced resistance in tissue remote to the initial infection. Although large-scale gene expression during systemic acquired resistance, which is induced by salicylic acid or necrotizing pathogens has been previously reported using a bacterial pathogen, the nature of systemic defense responses triggered by an incompatible necrotrophic fungal pathogen is not known. We examined transcriptional changes that occur during systemic defense responses in Arabidopsis plants inoculated with the incompatible fungal pathogen Alternaria brassicicola. Substantial changes (2.00-fold and statistically significant) were demonstrated in distal tissue of inoculated plants for 35 genes (25 up-regulated and 10 down-regulated), and expression of a selected subset of systemically expressed genes was confirmed using real-time quantitative polymerase chain reaction. Genes with altered expression in distal tissue included those with putative functions in cellular housekeeping, indicating that plants modify these vital processes to facilitate a coordinated response to pathogen attack. Transcriptional up-regulation of genes encoding enzymes functioning in the beta-oxidation pathway of fatty acids was particularly interesting. Transcriptional up-regulation was also observed for genes involved in cell wall synthesis and modification and genes putatively involved in signal transduction. The results of this study, therefore, confirm the notion that distal tissue of a pathogen-challenged plant has a heightened preparedness for subsequent pathogen attacks.

Impact of Ménière's disease on quality of life

OBJECTIVE

To describe health-related quality of life among patients with Ménière's disease in whom conventional therapy failed and who requested further medical intervention.

STUDY DESIGN

Pretreatment interviews to establish baseline quality of life characteristics before medical intervention.

SETTING

Tertiary referral center.

PATIENTS

19 adult patients, 12 women and 7 men, whose ages ranged from 32 to 83 years.

INTERVENTIONS

Pretreatment baseline interviews.

MAIN OUTCOME MEASURES

Quality of Well-being Scale, SF-12 Physical and SF-12 Mental scores, Center for Epidemiologic Studies-Depression Scale.

RESULTS

The Quality of Well-being score (0.561) indicated a loss of well-being from 1 to 0.561 = 43.9% in patients with Ménière's disease as compared with people with no symptoms and full functional status. The hypothesis that Quality of Well-being scores on days on which patients had symptoms characteristic of acute Ménière's disease episodes were lower than Quality of Well-being scores on days on which they did not report such symptoms was supported (p = 0.000). The reported SF-12 Physical mean score (38.9) was greater than 1 standard deviation below the general mean of 50, and the SF-12 Mental score (44.2) was 0.5 standard deviation below the general mean of 50. The Center for Epidemiologic Studies-Depression Scale score was 23, with a score 16 or greater indicating clinically significant depression.

CONCLUSIONS

The results suggest that the condition of patients with Ménière's disease may be measured by these instruments, that the instruments are in substantial agreement about the serious impairment in patients' quality of life, and that the days with acute episodes of Ménière's disease symptoms are significantly worse than the days without such symptoms. Treating physicians indicated surprise at the breadth and the level of debilitation characteristic of these patients with Ménière's disease.

Substitution model of sequence evolution for the human immunodeficiency virus type 1 subtype B gp120 gene over the C2-V5 region

Phylogenetic analyses frequently rely on models of sequence evolution that detail nucleotide substitution rates, nucleotide frequencies, and site-to-site rate heterogeneity. These models can influence hypothesis testing and can affect the accuracy of phylogenetic inferences. Maximum likelihood methods of simultaneously constructing phylogenetic tree topologies and estimating model parameters are computationally intensive, and are not feasible for sample sizes of 25 or greater using personal computers. Techniques that initially construct a tree topology and then use this non-maximized topology to estimate ML substitution rates, however, can quickly arrive at a model of sequence evolution. The accuracy of this two-step estimation technique was tested using simulated data sets with known model parameters. The results showed that for a star-like topology, as is often seen in human immunodeficiency virus type 1 (HIV-1) subtype B sequences, a random starting topology could produce nucleotide substitution rates that were not statistically different than the true rates. Samples were isolated from 100 HIV-1 subtype B infected individuals from the United States and a 620 nt region of the env gene was sequenced for each sample. The sequence data were used to obtain a substitution model of sequence evolution specific for HIV-1 subtype B env by estimating nucleotide substitution rates and the site-to-site heterogeneity in 100 individuals from the United States. The method of estimating the model should provide users of large data sets with a way to quickly compute a model of sequence evolution, while the nucleotide substitution model we identified should prove useful in the phylogenetic analysis of HIV-1 subtype B env sequences.

The importance of gender on outcome after major trauma: functional and psychologic outcomes in women versus men

BACKGROUND

Outcome after major trauma is an increasingly important focus of injury research. The effect of gender on functional and psychological outcomes has not been examined. The Trauma Recovery Project is a large, prospective, epidemiologic study designed to examine multiple outcomes after major trauma, including quality of life, functional outcome, and psychological sequelae such as depression and early symptoms of acute stress reaction. The specific objectives of the present report are to examine gender differences in short- and long-term functional and psychological outcomes in the Trauma Recovery Project population.

METHODS

Between December 1, 1993, and September 1, 1996, 1,048 eligible trauma patients triaged to four participating trauma center hospitals in the San Diego Regionalized Trauma System were enrolled in the study. The enrollment criteria for the study included age 18 years and older, admission Glasgow Coma Scale score of 12 or greater, and length of stay greater than 24 hours. Quality of life was measured after injury using the Quality of Well-being scale, a sensitive index to the well end of the functioning continuum (range, 0 = death to 1.000 = optimum functioning). Depression was assessed using the Center for Epidemiologic Studies Depression scale and early symptoms of acute stress reaction were assessed using the Impact of Events scale. Patient outcomes were assessed at discharge and at 6, 12, and 18 months after discharge.

RESULTS

Functional outcome was significantly worse at each follow-up time point in women (n = 313) versus men (n = 735). Quality of Well-being scale scores were markedly and significantly lower at 6-month follow-up in women compared with those in men (0.606 vs. 0.646, p < 0.0001). This association persisted at 12-month (0.637 vs. 0.6685, p < 0.0001) and 18-month (0.646 vs. 0.6696, p < 0.0001) follow-up. Women were also significantly more likely to be depressed at all follow-up time points (discharge odds ratio [OR] = 1.4, p < 0.05; 6-month follow-up OR = 2.2, p < 0.01; 12-month follow-up OR = 2.0, p < 0.01; 18-month follow-up OR = 2.2, p < 0.01) and to have early symptoms of acute stress reaction at discharge (OR = 1.4, p < 0.05). These differences remained significant and independent after adjusting for injury severity, mechanism, age, and sociodemographic factors.

CONCLUSION

Women are at risk for markedly worse functional and psychological outcomes after major trauma than men, independent of injury severity and mechanism. Gender differences in short- and long-term trauma outcomes have important implications for future studies of recovery from trauma.

Functional gamma-secretase inhibitors reduce beta-amyloid peptide levels in brain

Converging lines of evidence implicate the beta-amyloid peptide (Ass) as causative in Alzheimer's disease. We describe a novel class of compounds that reduce A beta production by functionally inhibiting gamma-secretase, the activity responsible for the carboxy-terminal cleavage required for A beta production. These molecules are active in both 293 HEK cells and neuronal cultures, and exert their effect upon A beta production without affecting protein secretion, most notably in the secreted forms of the amyloid precursor protein (APP). Oral administration of one of these compounds, N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester, to mice transgenic for human APP(V717F) reduces brain levels of Ass in a dose-dependent manner within 3 h. These studies represent the first demonstration of a reduction of brain A beta in vivo. Development of such novel functional gamma-secretase inhibitors will enable a clinical examination of the A beta hypothesis that Ass peptide drives the neuropathology observed in Alzheimer's disease.

The impact of major in-hospital complications on functional outcome and quality of life after trauma

BACKGROUND

Little is known about the impact of major in-hospital complications on functional outcome in the short- and long-term period after serious injury. The Trauma Recovery Project (TRP) is a large, prospective, epidemiologic study designed to examine multiple outcomes after major trauma, including quality of life and functional limitation. Patient outcomes were assessed at discharge and at 6, 12, and 18 months after discharge. The specific objectives of the present report are to examine the effect of postinjury complications on functional outcomes at discharge and at 6-, 12-, and 18-month follow-up time points in the TRP population.

METHODS

Between December 1, 1993, and September 1, 1996, 1,048 eligible trauma patients triaged to four participating trauma center hospitals in the San Diego Regionalized Trauma System were enrolled in the study. The enrollment criteria for the study included age 18 years or older; admission Glasgow Coma Scale score of 12 or greater; and length of stay greater than 24 hours. Quality of life was measured after injury using the Quality of Well-being (QWB) scale, a sensitive index to the well end of the functioning continuum (range, 0 [death] to 1.000 [optimum functioning]). Major in-hospital complications were assessed for 820 patients and were coded as pulmonary, cardiovascular, gastrointestinal, hepatic, hematologic, infections, renal, musculoskeletal, neurologic, and vascular, on the basis of standardized codes used in the Trauma Registry.

RESULTS

Major in-hospital complications were present in 83 (10.1%) patients. Discharge QWB scores were significantly lower in patients with major complications (0.394 vs. 0.402, p < 0.05). QWB scores were also significantly lower at 6-month follow-up in patients with major complications (0.575 vs. 0.637, p < 0.0001). Types of major complications with significantly lower 6-month follow-up QWB scores were pulmonary, gastrointestinal, infections, and musculoskeletal. Patients with major complications also had significantly lower 12-month (0.626 vs. 0.674, p < 0.01) and 18-month (0.646 vs. 0.681, p < 0.05) follow-up QWB scores. Pulmonary major complications and infections were associated with significantly lower QWB scores at 12-month follow-up.

CONCLUSION

These results provide new evidence that major in-hospital complications may have an important impact on functional outcomes after major trauma.

Likelihood-based tests of topologies in phylogenetics

Likelihood-based statistical tests of competing evolutionary hypotheses (tree topologies) have been available for approximately a decade. By far the most commonly used is the Kishino-Hasegawa test. However, the assumptions that have to be made to ensure the validity of the Kishino-Hasegawa test place important restrictions on its applicability. In particular, it is only valid when the topologies being compared are specified a priori. Unfortunately, this means that the Kishino-Hasegawa test may be severely biased in many cases in which it is now commonly used: for example, in any case in which one of the competing topologies has been selected for testing because it is the maximum likelihood topology for the data set at hand. We review the theory of the Kishino-Hasegawa test and contend that for the majority of popular applications this test should not be used. Previously published results from invalid applications of the Kishino-Hasegawa test should be treated extremely cautiously, and future applications should use appropriate alternative tests instead. We review such alternative tests, both nonparametric and parametric, and give two examples which illustrate the importance of our contentions.

Testing the hypothesis of a recombinant origin of human immunodeficiency virus type 1 subtype E

The human immunodeficiency virus type 1 (HIV-1) epidemic in Southeast Asia has been largely due to the emergence of clade E (HIV-1E). It has been suggested that HIV-1E is derived from a recombinant lineage of subtype A (HIV-1A) and subtype E, with multiple breakpoints along the E genome. We obtained complete genome sequences of clade E viruses from Thailand (93TH057 and 93TH065) and from the Central African Republic (90CF11697 and 90CF4071), increasing the total number of HIV-1E complete genome sequences available to seven. Phylogenetic analysis of complete genomes showed that subtypes A and E are themselves monophyletic, although together they also form a larger monophyletic group. The apparent phylogenetic incongruence at different regions of the genome that was previously taken as evidence of recombination is shown to be not statistically significant. Furthermore, simulations indicate that bootscanning and pairwise distance results, previously used as evidence for recombination, can be misleading, particularly when there are differences in substitution or evolutionary rates across the genomes of different subtypes. Taken jointly, our analyses suggest that there is inadequate support for the hypothesis that subtype E variants are derived from a recombinant lineage. In contrast, many other HIV strains claimed to have a recombinant origin, including viruses for which only a single parental strain was employed for analysis, do indeed satisfy the statistical criteria we propose. Thus, while intersubtype recombinant HIV strains are indeed circulating, the criteria for assigning a recombinant origin to viral structures should include statistical testing of alternative hypotheses to avoid inappropriate assignments that would obscure the true evolutionary properties of these viruses.

Coordinated plant defense responses in Arabidopsis revealed by microarray analysis

Disease resistance is associated with a plant defense response that involves an integrated set of signal transduction pathways. Changes in the expression patterns of 2,375 selected genes were examined simultaneously by cDNA microarray analysis in Arabidopsis thaliana after inoculation with an incompatible fungal pathogen Alternaria brassicicola or treatment with the defense-related signaling molecules salicylic acid (SA), methyl jasmonate (MJ), or ethylene. Substantial changes (up- and down-regulation) in the steady-state abundance of 705 mRNAs were observed in response to one or more of the treatments, including known and putative defense-related genes and 106 genes with no previously described function or homology. In leaf tissue inoculated with A. brassicicola, the abundance of 168 mRNAs was increased more than 2.5-fold, whereas that of 39 mRNAs was reduced. Similarly, the abundance of 192, 221, and 55 mRNAs was highly (>2.5-fold) increased after treatment with SA, MJ, and ethylene, respectively. Data analysis revealed a surprising level of coordinated defense responses, including 169 mRNAs regulated by multiple treatments/defense pathways. The largest number of genes coinduced (one of four induced genes) and corepressed was found after treatments with SA and MJ. In addition, 50% of the genes induced by ethylene treatment were also induced by MJ treatment. These results indicated the existence of a substantial network of regulatory interactions and coordination occurring during plant defense among the different defense signaling pathways, notably between the salicylate and jasmonate pathways that were previously thought to act in an antagonistic fashion.

Purification and cloning of amyloid precursor protein beta-secretase from human brain

Proteolytic processing of the amyloid precursor protein (APP) generates amyloid beta (Abeta) peptide, which is thought to be causal for the pathology and subsequent cognitive decline in Alzheimer's disease. Cleavage by beta-secretase at the amino terminus of the Abeta peptide sequence, between residues 671 and 672 of APP, leads to the generation and extracellular release of beta-cleaved soluble APP, and a corresponding cell-associated carboxy-terminal fragment. Cleavage of the C-terminal fragment by gamma-secretase(s) leads to the formation of Abeta. The pathogenic mutation K670M671-->N670L671 at the beta-secretase cleavage site in APP, which was discovered in a Swedish family with familial Alzheimer's disease, leads to increased beta-secretase cleavage of the mutant substrate. Here we describe a membrane-bound enzyme activity that cleaves full-length APP at the beta-secretase cleavage site, and find it to be the predominant beta-cleavage activity in human brain. We have purified this enzyme activity to homogeneity from human brain using a new substrate analogue inhibitor of the enzyme activity, and show that the purified enzyme has all the properties predicted for beta-secretase. Cloning and expression of the enzyme reveals that human brain beta-secretase is a new membrane-bound aspartic proteinase.

Covariation of physical and mental symptoms across illnesses: results of a factor analytic study

OBJECTIVE

Chronic illnesses are associated with reports of symptoms, problems, and dysfunction along multiple dimensions. To determine if the dimensionality is disease-specific and whether physical and emotional symptoms are concomitant and inseparable aspects of the illness experience, we present a factor analysis of symptom and problem reports from five different chronic conditions.

METHOD

People with five different conditions participated in this study: multiple sclerosis (MS) (n = 263), non-insulin-dependent diabetes mellitus (n = 420), nonhead nonneck injury trauma (n = 852), and a group of terminal patients comprised of acquired immune deficiency syndrome (AIDS) (n = 99) and cancer (n = 74) patients. Participants were asked to complete the Quality of Well-Being Scale (QWB) and symptom items from the QWB were factor analyzed.

RESULTS

Both within each condition and across conditions, two factors accounted for the majority of the explained variance and could be described as an Observable Limitations factor and a Subjective Symptoms factor.

CONCLUSIONS

Our factor analyses suggest that physical and emotional symptoms covary and are common to different types of illness.

FVB/N (H2(q)) mouse is resistant to arthritis induction and exhibits a genomic deletion of T-cell receptor V beta gene segments

Animal models of autoimmune diseases have been instrumental in advancing our understanding of autoimmunity in humans. Collagen-induced arthritis (CIA) in mice is an autoimmune disease model of rheumatoid arthritis. Susceptibility to CIA in mice is linked to genes of the major histocompatibility complex (MHC). CD4(+) T cells that express the T-cell receptor (TCR) Tcra-V11.1 and/or Tcrb-V8.2 play a key role in the pathogenesis of arthritis in the DBA/1 mouse (H2(q)). We identified an inbred mouse strain, FVB/NJ (H2(q)), that is resistant to arthritis induction and exhibits a genomic deletion of certain Tcrb-V gene segments. We report a novel polymerase chain reaction-based method for the rapid identification of new mouse strains that exhibit germline Tcrb-V gene deletions. We mapped for the first time both the 5' and 3' breakpoints of the Tcrb-V deletion in the FVB/NJ, SWR, SJL, C57L, and C57BR strains to within 1.1 kilobases. Since there is an association between a particular Tcra-V allele (Tcra-V11.1(d)) and arthritis susceptibility in H2(q) mouse strains, we examined the allelic polymorphisms of the Tcra-V11 gene subfamily members between the arthritis-susceptible DBA/1 mouse and the arthritis-resistant FVB/NJ mouse strain. The amino acid sequences of the Tcra-V11.1 alleles differ at two positions (codons 18 and 68). Therefore, the resistance of FVB/NJ mouse to arthritis induction may be due in part to Tcra-V11.1 coding sequence polymorphism and Tcrb-V8.2 gene segment deletion, as we have recently demonstrated in the case of SWR mouse strain.

T-cell receptor vbeta deletion and valpha polymorphism are responsible for the resistance of SWR mouse to arthritis induction

Collagen type II-induced arthritis (CIA) develops in susceptible mouse strains after intradermal injections of type II collagen (CII) in complete Freund's adjuvant (CFA). Susceptibility to CIA in mice is linked to genes of the major histocompatibility complex (MHC). Although the SWR mouse has a susceptible MHC haplotype (H2q), it is resistant to CIA. SWR exhibits at least two known immunological defects: (1) it contains a germline deletion of about 50% of T-cell receptor (TCR) Vbeta-chain gene segments, and (2) SWR is deficient in complement component C5. It has been shown that T cells that express TCRValpha11.1 and TCRVbeta8.2 play a substantial role in the pathogenesis of arthritis in the DBA/1 mouse (H2q). We generated SWR transgenic (tg) mice to determine whether the expression of pathogenic Valpha11.1 and/or Vbeta8.2 transgenes would confer arthritis susceptibility. Arthritis was induced in the SWR TCRalphabeta tg mice, but not in SWR TCRbeta tg mice. To address the role of Valpha11.1 in arthritis susceptibility, we examined the allelic polymorphisms of the Tcra-V11-gene subfamily members between the arthritis susceptible DBA/1 mouse and the arthritis-resistant SWR mouse strain. The amino acid sequences of the Valpha11.1 alleles differ at two positions (codons 18 and 68). Accordingly, these two amino acid changes are sufficient to allow the production of pathogenic T cells in SWR mice. This is the first demonstration of the association of a particular Tcra-V allele and arthritis susceptibility in mice.

Outcome after major trauma: 12-month and 18-month follow-up results from the Trauma Recovery Project

BACKGROUND

The importance of outcome after major injury has continued to gain attention in light of the ongoing development of sophisticated trauma care systems in the United States. The Trauma Recovery Project (TRP) is a large prospective epidemiologic study designed to examine multiple outcomes after major trauma in adults aged 18 years and older, including quality of life, functional outcome, and psychologic sequelae such as depression and posttraumatic stress disorder (PTSD). Patient outcomes were assessed at discharge and at 6, 12, and 18 months after discharge. The specific objectives of the present report are to describe functional outcomes at the 12-month and 18-month follow-ups in the TRP population and to examine the association of putative risk factors with functional outcome.

METHODS

Between December 1, 1993, and September 1, 1996, 1,048 eligible trauma patients triaged to four participating trauma center hospitals in the San Diego Regionalized Trauma System were enrolled in the TRP study. The admission criteria for patients were as follows: (1) age 18 years or older; (2) Glasgow Coma Scale score on admission of 12 or greater; and (3) length of stay greater than 24 hours. Functional outcome after trauma was measured before and after injury using the Quality of Well-Being (QWB) Scale, an index sensitive to the well end of the functioning continuum (0 = death, 1.000 = optimum functioning). Follow-up at 12 months after discharge was completed for 806 patients (79%), and follow-up at 18 months was completed for 780 patients (74%). Follow-up contact at any of the study time points (6, 12, or 18 months) was achieved for 926 (88%) patients.

RESULTS

The mean age was 36 +/- 14.8 years, and 70% of the patients were male; 52% were white, 30% were Hispanic, and 18% were black or other. Less than 40% of study participants were married or living together. The mean Injury Severity Score was 13 +/- 8.5, with 85% blunt injuries and a mean length of stay of 7 +/- 9.2 days. QWB scores before injury reflected the norm for a healthy adult population (mean, 0.810 +/- 0.171). At the 12-month follow-up, there were very high levels of functional limitation (QWB mean score, 0.670 +/- 0.137). Only 18% of patients followed at 12 months had scores above 0.800, the norm for a healthy population. There was no improvement in functional limitation at the 18-month follow-up (QWB mean score, 0.678 +/- 0.130). The majority of patients (80%) at the 18-month follow-up continued to have QWB scores below the healthy norm of 0.800. Postinjury depression, PTSD, serious extremity injury, and intensive care unit days were significant independent predictors of 12-month and 18-month QWB outcome.

CONCLUSION

This study demonstrates a prolonged and profound level of functional limitation after major trauma at 12-month and 18-month follow-up. This is the first report of long-term outcome based on the QWB Scale, a standardized quality-of-life measure, and provides new and provocative evidence that the magnitude of dysfunction after major injury has been underestimated. Postinjury depression, PTSD, serious extremity injury, and intensive care unit days are significantly associated with 12-month and 18-month QWB outcome.

Familial antiphospholipid antibody syndrome: criteria for disease and evidence for autosomal dominant inheritance

OBJECTIVE

To develop diagnostic criteria for a familial form of antiphospholipid antibody syndrome (APS), identify families with >1 affected member, examine possible modes of inheritance, and determine linkage to potential candidate genes.

METHODS

Family members of probands with primary APS were analyzed for clinical and laboratory abnormalities associated with APS. Families with > or =2 affected members were analyzed by segregation analysis and typed for candidate genetic markers.

RESULTS

Seven families were identified. Thirty of 101 family members met diagnostic criteria for APS. Segregation studies rejected both environmental and autosomal recessive models, and the data were best fit by either a dominant or codominant model. Linkage analysis showed independent segregation of APS and several candidate genes.

CONCLUSION

Clinical and laboratory criteria are essential to identify the spectrum of disease associated with APS. We believe a set of criteria was developed that can precisely define affected family members with APS. Modeling studies utilizing these criteria strongly support a genetic basis for disease in families with APS and suggest that a susceptibility gene is inherited in an autosomal dominant pattern. However, in these families, APS was not linked with HLA, Fas, or other candidate genes, including beta2-glycoprotein 1, HLA, T cell receptor beta chain, Ig heavy chain, antithrombin III, Fas ligand, factor V, complement factor H, IgK, and Fas.

The Quality of Well-Being Scale: critical similarities and differences with SF-36

PURPOSE

To summarize the development and application of a generic measure of health-related quality of life known as the Quality of Well-Being Scale (QWB).

BACKGROUND

The QWB is part of a general health policy model. The measure includes functional components for mobility, physical activity, and social activity. In addition, it includes a comprehensive list of symptoms and problems. QWB scoring allows placement of each individual on a continuum of wellness ranging from 0 (for dead) to 1.0 for asymptomatic full function. The General Health Policy Model combines this point in time measure with information on prognosis and mortality to estimate quality-adjusted life-years (QALYs). Forming a ratio of program costs to QALYs yields estimates of cost per quality-adjusted life year. Evidence supports the validity of the QWB for a wide variety of applications in population monitoring, descriptive studies of patient populations, and clinical trials. We offer a variety of comparisons between the QWB and Medical Outcomes Study Short Form 36 (SF-36).

MAIN FINDINGS

In comparison with the SF-36, the QWB provides less information on health profiles, but has the advantage of providing a metric that can be used for cost-utility or cost-effectiveness analysis. Although ceiling effects are common for some SF-36 subscales, perfect scores on the QWB are very rare. The QWB has an approximately normal distribution for populations of adults. Although, often criticized for not including a mental health component, we present evidence documenting the validity of the QWB for patients with psychological and psychiatric diagnoses.

CONCLUSIONS

The QWB and SF-36 are alternative comprehensive measures of health outcomes.

Comparison of the Quality of Well-being Scale and the SF-36 results among two samples of ill adults: AIDS and other illnesses

PURPOSE

To compare results of using the SF-36 Short Form 36 (SF-36) and the Quality of Well-being Scale (QWB) in characterizing health outcomes over time in patients having serious illnesses, including cancer and AIDS.

BACKGROUND

The SF-36 and the QWB are alternative measures of health-related quality of life. The SF-36 is a morbidity measure that features a profile of nine dimensions. The QWB is a preference-based measure that combines morbidity and mortality into a single number. However, the QWB can also be scored and used as a profile. We compare SF-36 and QWB scores with different scoring methods to assess validity and sensitivity to change over time in health outcomes for adult patients with HIV infection, cancer, and other serious illnesses.

SUBJECTS

201 adults with serious illnesses, including 99 with AIDS and 102 with cancer or other illnesses.

PROCEDURE

All subjects received both measures at baseline and at 6-month intervals thereafter, over a period of 21/2 years.

RESULTS

In the profile mode, the QWB captured outcomes that characterize the AIDS syndrome. The SF-36 differentiated between the AIDS and other illnesses patients on some scales, but without consistent direction. However, the overall QWB showed a decrease in quality of life over time for both the AIDS and other illnesses patients while the SF-36 did not. This is because many patients died and these were counted as outcomes by the QWB and as missing data by the SF-36.

CONCLUSIONS

The QWB appears to be better able to capture outcomes of serious illness over time than does the SF-36.

Outcome after major trauma: discharge and 6-month follow-up results from the Trauma Recovery Project

BACKGROUND

The study of both short-term and long-term outcomes after major trauma has become an increasingly important focus of injury research because of the improved survival rates attributable to the evolution of sophisticated trauma care systems. The Trauma Recovery Project (TRP) is a large prospective epidemiologic study designed to examine multiple outcomes after major trauma in adults aged 18 years and older, including quality of life, functional outcome, and psychologic sequelae such as depression and posttraumatic stress disorder (PTSD). Patient outcomes were assessed at discharge and at 6, 12, and 18 months after discharge. The specific objectives of the present report are to describe functional outcomes at the discharge and 6-month follow-up time points in the TRP population and to examine the association of putative risk factors with functional outcome.

METHODS

Between December 1, 1993, and September 1, 1996, 1,048 eligible trauma patients triaged to four participating trauma center hospitals in the San Diego Regionalized Trauma System were enrolled in the TRP study. The admission criteria for patients were as follows: (1) age 18 years or older, (2) Glasgow Coma Scale score on admission of 12 or greater, and (3) length of stay greater than 24 hours. Functional outcome after trauma was measured before and after injury using the Quality of Well-Being (QWB) scale, a more sensitive index to the well end of the functioning continuum (range, 0 = death to 1.000 = optimum functioning). Functional outcome was also measured using a standard activities of daily living (ADL) scale (range, 13 = full function to 47 = maximum dysfunction). Follow-up at 6 months after discharge was completed for 826 patients (79%).

RESULTS

The mean age was 36 +/- 14.8 years; 70% of the patients were male; 52% of the patients were white, 30% were Hispanic, and 18% were black or other. Less than 40% of study participants were married or living with a partner. The mean Injury Severity Score was 13 +/- 8.5, with 85% blunt injuries, and a mean length of stay of 7 +/- 9.2 days. QWB scores before injury reflected the norm for a healthy adult population (mean, 0.810 +/- 0.171). After major trauma, QWB scores at discharge showed a significant degree of functional limitation (mean, 0.401 +/- 0.045). At 6-month follow-up, QWB scores continued to show high levels of functional limitation (mean, 0.633 +/- 0.122). Limitation measured using the standard ADL scale found only moderate dysfunction at discharge (mean, 30.0 +/- 7.7) and at 6-month follow-up (mean, 15.0 +/- 4.2). Postinjury depression, PTSD, serious extremity injury, and length of stay were significant independent predictors of 6-month QWB outcome.

CONCLUSION

Postinjury functional limitation is a clinically significant complication in trauma patients at discharge and a 6-month follow-up. The QWB yields a more sensitive assessment of functional status than traditional ADL instruments. Postinjury depression, PTSD, serious extremity injury, and length of stay are significantly associated with 6-month QWB outcome.

Fine mapping of a genetic locus for Peutz-Jeghers syndrome on chromosome 19p

Peutz-Jeghers syndrome (PJS) was recently mapped in a single report to the telomeric region of chromosome 19p (A. Hemminki et al., Nat. Genet., 15: 87-90, 1997). Our studies confirm this location and provide further localization of the PJS locus. In the five families examined, there were no recombinants with the marker D19S886. The multipoint log odds score at D19S886 is 7.52, and we found no evidence for genetic heterogeneity. We also found that all carriers expressed the PJS phenotype and no noncarriers displayed PJS sequellae, indicating complete penetrance with no sporadic cases.

Reply to Roberts: cooperation is an outcome, not a mechanism

No Abstract

Quality-adjusted life years lost to arthritis: effects of gender, race,and social class

OBJECTIVE

To estimate the public health impact of self-reported arthritis in terms of Quality-Adjusted Life Years.

METHOD

The Quality of Well-being Scale (QWB) is a general measure of health-related quality of life that scores levels of wellness on a continuum between death (0.0) and optimum functioning (1.0). Values for the QWB were imputed for the National Health Interview Survey. These estimates were adjusted for mortality based on the life tables. Age-specific estimates were obtained for those reporting arthritis and compared to estimators for the population not reporting arthritis. These estimates were broken down by race (white versus nonwhite), gender and socioeconomic status.

RESULTS

The expected life years lost because of arthritis were 1.86 (95% confidence interval 1.40-2.32 years). Arthritis was reported more often among those of lower income, those living in rural areas, those of lower educational attainment, and older respondents. Men and women did not differ in rates of reporting arthritis, but men with arthritis had lower QWB scores than women with arthritis.

CONCLUSION

Arthritis has a significant public health impact.