Clozapine therapeutic drug monitoring – experience from a large London NHS trust

Introduction

Clozapine is a high-risk drug that is used widely in Secondary and Tertiary Centres.1 Therapeutic Drug Monitoring (TDM) advice and recommendation is readily available from distinguished authors.2,3 The rate of clozapine TDM, appropriate sample collection for TDM, appropriate actions following a clozapine level varies between services and prescribers within our organisation.

Aim

To establish how many current West London NHS Trust (WLT) patients had a clozapine TDM, how many plasma samples collected for TDM were done appropriately, the proportion of patients with an appropriately collected plasma sample result within the largely accepted therapeutic range, and whether there was documentation that the plasma level was reviewed and if any prescription changes were made.

Methods

Approval to undertake the service evaluation was given by the Trust clinical governance and audit committee as ethical review as not required. No patient identifiable details were shared or collected. All patients who had been registered on the Trusts clozapine patient monitoring service for over 8 weeks were enrolled. Anonymised patient demographic data was collected including concomitant medication. Plasma levels were sought for every patient enrolled. The appropriateness of the samples taken were scrutinised. The plasma level result was collected. Electronic patient notes were also scrutinised to assess actions following the plasma level result. Data were collected in a binary yes/no format and results calculated as a percentage. Data was stored and collected in accordance to Trust General Data Protection Regulation (GDPR).

Results

In total 316 patients were included. 97% of these patients had evidence of TDM levels done during the time of the audit. 88% of these patients’ samples were done correctly. Only 45% of patients had levels within the widely acceptable therapeutic range. Of those patients whose levels fell outside the therapeutic range less than half (42%) had documentation that the level was reviewed.

Discussion/Conclusion

It is widely accepted that clozapine TDM when done accurately can be a vital source of information to inform prescribers on the appropriate dose, concordance and toxicity of clozapine therapy. Our Trust showed evidence of routine clozapine TDM. There was some variation in the appropriate sample collection but what was most alarming is the lack of documentation that action was taken when the TDM level was outside the general acceptable range. Standardising the actions following clozapine TDM needs to be a priority for the Trust if clozapine TDM is to continue to be carried out in almost 100% of the patient population.

References

1. Taylor DM, Barnes TRE, Young AH. The Maudsley Prescribing Guidelines in Psychiatry 14th Edition. Wiley Blackwell.

2. Taylor DM et al. The use of clozapine plasma levels in optimising therapy. Psych Bull 1995:19:753-755

3. Perry PJ. Therapeutic drug monitoring of antipsychotics. Psychopharmacology 200; 148:83-89

A highly specialist mental health prescribing pharmacist in a virtual GP practice - experience from a large London general practice

Introduction

Historically, the career path for highly specialist pharmacists has been focussed on secondary and tertiary services. Recent developments to ensure high quality medication optimisation and improvement of patient access to appropriate medication has seen many pharmacists join GP practices. Alongside this is the drive by the NHS to improve the quality of mental health care in the primary care setting. Digitalisation and providing virtual platforms also improves access to health care for many individuals who are less able to commute and provides an option when there is disruption to face to face services.

Aims

To identify the number of appointments completed in an 8-week period, and evaluate the types of referrals, prescription details and the feedback from consultations with the Highly Specialist Mental Health Pharmacist.

Methods

Anonymised details from consultations carried out in an 8-week period were collected, which included details of appointments, the referral process, prescription details and feedback. The data underwent descriptive statistical analysis. Ethical review was not required as the study was a service evaluation.

Results

The reviewed patient journey for those newly identified with a mental illness, those who self identify as having a mental illness and those with a complex mental illness is presented. Post holder experience is shared. In a 7 clinical session week, with 30 minute consultations a total of 445 patients were scheduled an appointment, 393 patients completed their consultation. 61% of patients were referred for psychotherapy, 18% referred to secondary services. In 43% of patients’ medication was prescribed by the pharmacist, 32% had no medication prescribed while 23% of patients had medication deprescribed (stopped or reduced) Patient feedback was available for 50 patients, 47 left 5 star reviews, 3 left 1 star reviews as they could not get the platform link to work to attend the consultation.

Discussion/Conclusion

Although a small study, the preliminary data shows a high rate of patient attendance and feedback from patients was higher than expected. There is a single point of contact for the practice to risk assess, screen and follow up patients with a mental illness (including serious mental illness). Working in isolation, virtually and making pharmacist interventions after prescribing has occurred are very different ways of working compared to secondary care. With the correct infrastructure, improved referral rates and understanding of specialist pharmacist knowledge and experience - pharmacists can look to joining GP practices as a career option in a highly specialist role.

References

1. NHS London Clinical Networks and Healthy London Partnership. A review of the scientific literature informing the development of models of primary care in mental health. September 2017. Available from: https://www.healthylondon.org/wp-content/uploads/2017/11/Literature-review-Primary-care-mental-health-service-development.pdf

2. Keith Ridge. Pharmacists Prescribing Better Care. NHS England. April 2018. Available from: https://www.england.nhs.uk/blog/pharmacists-prescribing-better-care/

Plant roots employ cell-layer-specific programs to respond to pathogenic and beneficial microbes

Plant roots are built of concentric cell layers that are thought to respond to microbial infections by employing specific, genetically defined programs. Yet, the functional impact of this radial organization remains elusive, particularly due to the lack of genome-wide techniques for monitoring expression at a cell-layer resolution. Here, cell-type-specific expression of tagged ribosomes enabled the isolation of ribosome-bound mRNA to obtain cell-layer translatomes (TRAP-seq, translating ribosome affinity purification and RNA sequencing). After inoculation with the vascular pathogen Verticillium longisporum, pathogenic oomycete Phytophthora parasitica, or mutualistic endophyte Serendipita indica, root cell-layer responses reflected the fundamentally different colonization strategies of these microbes. Notably, V. longisporum specifically suppressed the endodermal barrier, which restricts fungal progression, allowing microbial access to the root central cylinder. Moreover, localized biosynthesis of antimicrobial compounds and ethylene differed in response to pathogens and mutualists. These examples highlight the power of this resource to gain insights into root-microbe interactions and to develop strategies in crop improvement.

Phytophthora zoospores: From perception of environmental signals to inoculum formation on the host-root surface

To explore moist soils and to target host plants, phytopathogenic Phytophthora species utilize the sensory and propulsion capabilities of the biflagellate unicellular zoospores they produce. Zoospore motion and interactions with the microenvironment are of primary importance for Phytophthora physiology. These are also of critical significance for plant pathology in early infection sequential events and their regulation: the directed zoospore migration toward the host, the local aggregation and adhesion at the host penetration site. In the soil, these early events preceding the root colonization are orchestrated by guidance factors, released from the soil particles in water films, or emitted within microbiota and by host plants. This signaling network is perceived by zoospores and results in coordinated behavior and preferential localization in the rhizosphere. Recent computational and structural studies suggest that rhizospheric ion and plant metabolite sensing is a key determinant in driving zoospore motion, orientation and aggregation. To reach their target, zoospores respond to various molecular, chemical and electrical stimuli. However, it is not yet clear how these signals are generated in local soil niches and which gene functions govern the sensing and subsequent responses of zoospores. Here we review studies on the soil, microbial and host-plant factors that drive zoospore motion, as well as the adaptations governing zoospore behavior. We propose several research directions that could be explored to characterize the role of zoospore microbial ecology in disease.

Extensin arabinosylation is involved in root response to elicitors and limits oomycete colonization

BACKGROUND AND AIMS

Extensins are hydroxyproline-rich glycoproteins thought to strengthen the plant cell wall, one of the first barriers against pathogens, through intra- and intermolecular cross-links. The glycan moiety of extensins is believed to confer the correct structural conformation to the glycoprotein, leading to self-assembly within the cell wall that helps limit microbial adherence and invasion. However, this role is not clearly established.

METHODS

We used Arabidopsis thaliana mutants impaired in extensin arabinosylation to investigate the role of extensin arabinosylation in root-microbe interactions. Mutant and wild-type roots were stimulated to elicit an immune response with flagellin 22 and immunolabelled with a set of anti-extensin antibodies. Roots were also inoculated with a soilborne oomycete, Phytophthora parasitica, to assess the effect of extensin arabinosylation on root colonization.

KEY RESULTS

A differential distribution of extensin epitopes was observed in wild-type plants in response to elicitation. Elicitation also triggers altered epitope expression in mutant roots compared with wild-type and non-elicited roots. Inoculation with the pathogen P. parasitica resulted in enhanced root colonization for two mutants, specifically xeg113 and rra2.

CONCLUSIONS

We provide evidence for a link between extensin arabinosylation and root defence, and propose a model to explain the importance of glycosylation in limiting invasion of root cells by pathogenic oomycetes.

Surgeon volume and hospital volume in endocrine neck surgery: how many procedures are needed for reaching a safety level and acceptable costs? A systematic narrative review

The relationship between quality of care and provider's experience is well known in all fields of surgery. Even in thyroidectomies and parathyroidectomies, the emphasis on positive volume-outcome relationships is believed. It led us to an evaluation of volume activity's impact in terms of quality of care. A systematic narrative review was performed. According to the PRISMA criteria, we selected 87 paper and, after the study selection was performed, 22 studies were finally included in this review. All articles included were unanimous in attributing to activity volume of surgeons as well as centers a substantial importance. Some differences in outcomes between these investigated categories have been found: best results of the high volume surgeon is evident expecially in terms of complications, on the contrary best outcomes of a high volume center are mainly economics, such as hospital stay and general costs of the procedures. A cut-off of 35-40 thyroidectomies per year for single surgeon, and 90-100 thyroidectomies for single center appears reasonable for identifying an adequate activity. Concerning parathyroidectomy, we can consider reasonable a cut off at 10-12 operations/year. More studies are needed in a European or more circumscribed perspective.

Mapping the centers performing endocrine neck surgery in Italy

BACKGROUND

Quality of care and provider's experience seem to be strictly connected in any field of surgery. Aim of this study is to identify a method to classify the centers on the basis of the number of thyroidectomies and parathyroidectomies performed.

METHODS

We listed 666 centers performing endocrine neck surgery in 2015, from the database of the Italian Health Ministry. We performed a descriptive statistic analysis with a dedicated software. We identified the outliers, according to a previous literature review, in those centers performing >1000 and < 10 thyroidectomies, >100 and < 3 parathyroidectomies and we excluded them to our analysis. The remaining centers were grouped in a box-plot. Third quartile, median, procedures performed/3rd quartile value ratio (Standardized Hospitalization Ratio, SHR, superior cut-off), Romamedian/3rd quartile values ratio (inferior cut-off) were calculated. These centers were charted in a bar graph and three zones were identified: "excellence" (SHR>1.1), "SHR", "alert" (between the two cut-offs) and "risk" (under the lower cut-off).

RESULTS

35743 thyroidectomies and 2306 parathyroidectomies were performed in Italy in 2015. After the outliers' exclusion, 407 and 157 centers performing respectively thyroidectomies and parathyroidectomies were analysed. A median value of respectively 37 thyroidectomies and 6 parathyroidectomies, and a 3rd quartile cut-off of respectively 85 and 12 were calculated. Concerning all the 666 centers, we found: 95 excellence centers for thyroidectomy and 33 for parathyroidectomy, respectively 18 and 17 falling into superior cut-off line, 100 and 29 in the alert zone, 453 and 587 in the risk zone.

CONCLUSIONS

Our method, according to the literature data, highlighted a number of thyroidectomies and parathyroidectomies performed in low volume centers. Looking for an optimization in health organization, we can consider some measures such as a net of tutorship of the "alert" hospitals by the excellence ones and a discouragement of the "risk" hospitals in performing endocrine neck surgery.

The coexistence of primary hyperparathyroidism and thyroid nodules: should the preoperative work-up of the parathyroid and the thyroid diseases be specifically adjusted?

INTRODUCTION AND OBJECTIVES

Primary hyperparathyroidism (PHPT) can be found in concomitance with thyroid disease (TD) in a high frequency of cases. In this context the diagnostic exams for localizing the enlarged parathyroid(s) gland(s) could be less reliable or nonconclusive. Moreover, the thyroid carcinoma seems to be more frequent compared to that isolated thyroid desease and, therefore, carefully investigated. The main goal of the present study is to evaluate which diagnostic tool (US, MIBI) is more reliable for localizing the site of the PTH hypersecretion and to confirm if it is always advantageous a combination of both exams. Besides, we evaluated the incidence of thyroid carcinoma in our series of patients.

PATIENTS AND METHODS

A review of available data of 73 patients who underwent total thyroidectomy + parathyroidectomy from 2003 and 2014 was performed. The preoperative workup included systematically US and MIBI whose results were considered true positive when at least the side (left/right) of the parathyroid affected were concordant with the surgical report, settled as the gold standard, according to the Cox nonnested model. The connection between the diagnostic results of US versus MIBI was calculated with the Cohen K index for evaluating their overlap. The average of the thyroid carcinoma were also calculated.

RESULTS

The difference between respectively US versus surgical report (p value=0.73) and MIBI versus surgical report (p value=0.81) were not significant. The low Cohen K index showed that both US and MIBI are complementary. In 23 patients (32,9%) a thyroid carcinoma was found.

CONCLUSIONS

The association of MIBI and neck US is mandatory in the first evaluation of patients undergoing thyroidectomy and parathyroid excision simultaneously. The high prevalence of thyroid carcinoma in this specific context suggests a more aggressive diagnostic and surgical behaviour.

Comparison of minimally invasive parathyroidectomy under local anaesthesia and minimally invasive video-assisted parathyroidectomy for primary hyperparathyroidism: a cost analysis

BACKGROUND

Primary hyperparathyroidism (PHPT) origins from a solitary adenoma in 70- 95% of cases. Moreover, the advances in methods for localizing an abnormal parathyroid gland made minimally invasive techniques more prominent. This study presents a micro-cost analysis of two parathyroidectomy techniques.

PATIENTS AND METHODS

72 consecutive patients who underwent minimally invasive parathyroidectomy, video-assisted (MIVAP, group A, 52 patients) or "open" under local anaesthesia (OMIP, group B, 20 patients) for PHPT were reviewed. Operating room, consumable, anaesthesia, maintenance costs, equipment depreciation and surgeons/anaesthesiologists fees were evaluated. The patient's satisfaction and the rate of conversion to conventional parathyroidectomy were investigated. T-Student's, Kolmogorov-Smirnov tests and Odds Ratio were used for statistical analysis.

RESULTS

1 patient of the group A and 2 of the group B were excluded from the cost analysis because of the conversion to the conventional technique. Concerning the remnant patients, the overall average costs were: for Operative Room, 1186,69 € for the MIVAP group (51 patients) and 836,11 € for the OMIP group (p<0,001); for the Team, 122,93 € (group A) and 90,02 € (group B) (p<0,001); the other operative costs were 1388,32 € (group A) and 928,23 € (group B) (p<0,001). The patient's satisfaction was very strongly in favour of the group B (Odds Ratio 20,5 with a 95% confidence interval).

CONCLUSIONS

MIVAP is more expensive compared to the "open" parathyroidectomy under local anaesthesia due to the costs of general anaesthesia and the longer operative time. Moreover, the patients generally prefer the local anaesthesia. Nevertheless, the rate of conversion to the conventional parathyroidectomy was relevant in the group of the local anaesthesia compared to the MIVAP, since the latter allows a four-gland exploration.

The receptor kinase IMPAIRED OOMYCETE SUSCEPTIBILITY1 attenuates abscisic acid responses in Arabidopsis

In plants, membrane-bound receptor kinases are essential for developmental processes, immune responses to pathogens and the establishment of symbiosis. We previously identified the Arabidopsis (Arabidopsis thaliana) receptor kinase IMPAIRED OOMYCETE SUSCEPTIBILITY1 (IOS1) as required for successful infection with the downy mildew pathogen Hyaloperonospora arabidopsidis. We report here that IOS1 is also required for full susceptibility of Arabidopsis to unrelated (hemi)biotrophic filamentous oomycete and fungal pathogens. Impaired susceptibility in the absence of IOS1 appeared to be independent of plant defense mechanism. Instead, we found that ios1-1 plants were hypersensitive to the plant hormone abscisic acid (ABA), displaying enhanced ABA-mediated inhibition of seed germination, root elongation, and stomatal opening. These findings suggest that IOS1 negatively regulates ABA signaling in Arabidopsis. The expression of ABA-sensitive COLD REGULATED and RESISTANCE TO DESICCATION genes was diminished in Arabidopsis during infection. This effect on ABA signaling was alleviated in the ios1-1 mutant background. Accordingly, ABA-insensitive and ABA-hypersensitive mutants were more susceptible and resistant to oomycete infection, respectively, showing that the intensity of ABA signaling affects the outcome of downy mildew disease. Taken together, our findings suggest that filamentous (hemi)biotrophs attenuate ABA signaling in Arabidopsis during the infection process and that IOS1 participates in this pathogen-mediated reprogramming of the host.

Paliperidone palmitate long-acting injection--prospective year-long follow-up of use in clinical practice

OBJECTIVE

To follow-up patients prescribed paliperidone palmitate long-acting injection (PP) over 1 year to determine factors predicting continuation with PP treatment.

METHOD

Naturalistic observation of patients registered as starting PP in a single healthcare unit in London, UK. Monovariate and multivariate (Cox regression) analysis of factors predicting continuation at 1 year.

RESULTS

Data were available for 210 patients consecutively prescribed PP of whom 10 were lost to follow-up. At 1 year, 65% of 200 patients (176 with a diagnosis of schizophrenia or schizoaffective disorder) started on PP were still receiving it. The main reason for discontinuation was perceived ineffectiveness (52% of discontinuers); only 10 subjects (5% of total) discontinued because of adverse effects. Initiation as an out-patient [hazard ratio (HR) 0.39, 95%CI, 0.20, 0.67, P = 0.001]; being switched from risperidone (HR 0.56, 95%CI 0.32, 0.94, P = 0.026) and correct initiation (HR 0.56, 95%CI 0.34, 0.93, P = 0.024) were significantly associated with a lower likelihood of discontinuation.

CONCLUSION

Paliperidone palmitate was effective and well tolerated in this naturalistic cohort. Optimising treatment by targeting PP for patients identified as having lower risk of discontinuation can give rise to continuation rates approaching 80% at 1 year.

The Phytophthora parasitica RXLR effector penetration-specific effector 1 favours Arabidopsis thaliana infection by interfering with auxin physiology

Pathogenic oomycetes have evolved RXLR effectors to thwart plant defense mechanisms and invade host tissues. We analysed the function of one of these effectors (Penetration-Specific Effector 1 (PSE1)) whose transcript is transiently accumulated during penetration of host roots by the oomycete Phytophthora parasitica. Expression of PSE1 protein in tobacco (Nicotiana tabacum and Nicotiana benthamiana) leaves and in Arabidopsis thaliana plants was used to assess the role of this effector in plant physiology and in interactions with pathogens. A pharmacological approach and marker lines were used to charcterize the A. thaliana phenotypes. Expression of PSE1 in A. thaliana led to developmental perturbations associated with low concentrations of auxin at the root apex. This modification of auxin content was associated with an altered distribution of the PIN4 and PIN7 auxin efflux carriers. The PSE1 protein facilitated plant infection: it suppressed plant cell death activated by Pseudomonas syringae avirulence gene AvrPto and Phytophthora cryptogea elicitin cryptogein in tobacco and exacerbated disease symptoms upon inoculation of transgenic A. thaliana plantlets with P. parasitica in an auxin-dependant manner. We propose that P. parasitica secretes the PSE1 protein during the penetration process to favour the infection by locally modulating the auxin content. These results support the hypothesis that effectors from plant pathogens may act on a limited set of targets, including hormones.

The subcellular localization of Tubby-like proteins and participation in stress signaling and root colonization by the mutualist Piriformospora indica

Tubby and Tubby-like proteins (TLPs) were first discovered in mammals, where they are involved in the development and function of neuronal cells. Due to their importance as plasma membrane (PM)-tethered transcription factors or mediators of vesicle trafficking, their lack causes obesity and other disease syndromes. Phosphatidylinositol 4,5-bisphosphate binding of the carboxyl-terminal Tubby domain attaches these proteins to the PM and vesicles and is essential for function. TLPs are conserved across eukaryotic kingdoms including plants, suggesting fundamental biological functions of TLPs. Plant TLPs possess an amino-terminal F-box domain that distinguishes them from other eukaryotic TLPs. Arabidopsis (Arabidopsis thaliana) encodes 11 AtTLPs that fall into six phylogenetic clades. We identified the significance of AtTLPs for root colonization of Arabidopsis by the mutualistic fungus Piriformospora indica. Our results further indicate conserved phosphatidylinositol 4,5-bisphosphate-binding sites in the Tubby domains that are required for PM anchoring of AtTLPs. More detailed studies revealed phospholipase C-triggered release of AtTLP3 from the PM, indicating a conserved mechanism as reported for mammalian Tubby and TLP3. We further show that hydrogen peroxide stimulates the release of AtTLP3 from the PM, presumably for activating downstream events. Different from mammalian homologs, the amino-terminal part of almost all AtTLPs has nucleocytosolic and plastidial localization patterns. Thus, it is tempting to assume that TLPs translate reactive oxygen species currents into signaling not only for transcriptional regulation in the nucleus but also affect plastid-associated functions after release from the PM.

Leucine-rich repeat receptor kinases are sporadically distributed in eukaryotic genomes

Background

Plant leucine-rich repeat receptor-like kinases (LRR-RLKs) are receptor kinases that contain LRRs in their extracellular domain. In the last 15 years, many research groups have demonstrated major roles played by LRR-RLKs in plants during almost all developmental processes throughout the life of the plant and in defense/resistance against a large range of pathogens. Recently, a breakthrough has been made in this field that challenges the dogma of the specificity of plant LRR-RLKs.

Results

We analyzed ~1000 complete genomes and show that LRR-RK genes have now been identified in 8 non-plant genomes. We performed an exhaustive phylogenetic analysis of all of these receptors, revealing that all of the LRR-containing receptor subfamilies form lineage-specific clades. Our results suggest that the association of LRRs with RKs appeared independently at least four times in eukaryotic evolutionary history. Moreover, the molecular evolutionary history of the LRR-RKs found in oomycetes is reminiscent of the pattern observed in plants: expansion with amplification/deletion and evolution of the domain organization leading to the functional diversification of members of the gene family. Finally, the expression data suggest that oomycete LRR-RKs may play a role in several stages of the oomycete life cycle.

Conclusions

In view of the key roles that LRR-RLKs play throughout the entire lifetime of plants and plant-environment interactions, the emergence and expansion of this type of receptor in several phyla along the evolution of eukaryotes, and particularly in oomycete genomes, questions their intrinsic functions in mimicry and/or in the coevolution of receptors between hosts and pathogens.

An Arabidopsis (malectin-like) leucine-rich repeat receptor-like kinase contributes to downy mildew disease

Biotrophic filamentous plant pathogens frequently establish intimate contact with host cells through intracellular feeding structures called haustoria. To form and maintain these structures, pathogens must avoid or suppress defence responses and reprogramme the host cell. We used Arabidopsis whole-genome microarrays to characterize genetic programmes that are deregulated during infection by the biotrophic' oomycete downy mildew pathogen, Hyaloperonospora arabidopsidis. Marked differences were observed between early and late stages of infection, but a gene encoding a putative leucine-rich repeat receptor-like kinase (LRR-RLK) was constantly up-regulated. We investigated the evolutionary history of this gene and noticed it being one of the first to have emerged from a common ancestral gene that gave rise to a cluster of 11 genes through duplications. The encoded LRR-RLKs harbour an extracellular malectin-like (ML) domain in addition to a short stretch of leucine-rich repeats, and are thus similar to proteins from the symbiosis receptor-like kinase family. Detailed expression analysis showed that the pathogen-responsive gene was locally expressed in cells surrounding the oomycete. A knockout mutant showed reduced downy mildew infection, but susceptibility was fully restored through complementation of the mutation, suggesting that the (ML-)LRR-RLK contributes to disease. According to the mutant phenotype, we denominated it Impaired Oomycete Susceptibility 1 (IOS1).

Getting the most from the host: how pathogens force plants to cooperate in disease

Plant diseases caused by pathogenic microorganisms remain a major limitation in many crop production systems. Nonetheless, constitutive and inducible defense mechanisms render most plants inaccessible to pathogens, making disease an exception rather than a common outcome of plant-microbe interactions. Defense mechanisms and associated pathogen resistance were thus of key interest to many plant pathologists, and many of the molecular mechanisms underlying resistance have been elucidated over the last few decades. In recent years, the analysis of physiological and molecular determinants accounting for successful infection and eventual disease has become a topic of prime scientific interest. The hunt is now on for pathogen effectors subverting the host cell and for the plant compatibility functions manipulated by these effectors. An understanding of the molecular mechanisms underlying successful infection should make it possible to develop new crop protection strategies based on interference with compatibility to prevent disease. This review is addressing plant susceptibility and highlights a number of host processes that have been shown to be induced or subverted to facilitate infection. In particular, we focus on those processes that appear to be manipulated by filamentous fungal and oomycete pathogens.

The immediate activation of defense responses in Arabidopsis roots is not sufficient to prevent Phytophthora parasitica infection

*The outcome of plant-microbe interactions is determined by a fine-tuned molecular interplay between the two partners. Little is currently known about the molecular dialogue between plant roots and filamentous pathogens. We describe here a new pathosystem for the analysis of molecular mechanisms occurring during the establishment of a compatible interaction between Arabidopsis thaliana roots and a root-infecting oomycete. *We performed cytological and genetic analyses of root infection during the compatible interaction between A. thaliana and Phytophthora parasitica. *Phytophthora parasitica uses appressoria to penetrate A. thaliana roots. Initial biotrophic growth is accompanied by the formation of haustoria, and is followed by a necrotrophic lifestyle. Arabidopsis thaliana mutants with impaired salicylic acid (SA), jasmonic acid (JA) or ethylene (ET) signaling pathways are more susceptible than the wild-type to infection. The salicylate- and jasmonate-dependent signaling pathways are concertedly activated when P. parasitica penetrates the roots, but are downregulated during invasive growth, when ethylene-mediated signaling predominates. *Thus, defense responses in A. thaliana roots are triggered immediately on contact with P. parasitica. Our findings suggest that the pattern of early defense mechanism activation differs between roots and leaves.

Strategies of attack and defense in plant-oomycete interactions, accentuated for Phytophthora parasitica Dastur (syn. P. Nicotianae Breda de Haan)

Oomycetes from the genus Phytophthora are fungus-like plant pathogens that are devastating for agriculture and natural ecosystems. Due to their particular physiological characteristics, no efficient treatments against diseases caused by these microorganisms are presently available. To develop such treatments, it appears essential to dissect the molecular mechanisms that determine the interaction between Phytophthora species and host plants. Available data are scarce, and genomic approaches were mainly developed for the two species, Phytophthora infestans and Phytophthora sojae. However, these two species are exceptions from, rather than representative species for, the genus. P. infestans is a foliar pathogen, and P. sojae infects a narrow range of host plants, while the majority of Phytophthora species are quite unselective, root-infecting pathogens. To represent this majority, Phytophthora parasitica emerges as a model for the genus, and genomic resources for analyzing its interaction with plants are developing. The aim of this review is to assemble current knowledge on cytological and molecular processes that are underlying plant-pathogen interactions involving Phytophthora species and in particular P. parasitica, and to place them into the context of a hypothetical scheme of co-evolution between the pathogen and the host.

Truncated and RIP-degenerated copies of the LTR retrotransposon are clustered in a pericentromeric region of the genome

The LMR1 5.2 kb interspersed repeat of Leptosphaeria maculans was described by Taylor and Borgmann [Mol. Plant Microbe Interact. 7 (1994) 181] as an uncharacterized repeated element sharing homologies with both LINEs and SINEs. Here, we used the LMR1 sequence as a template to identify the full-length element within a 184-kb genomic sequence corresponding to the pericentromeric region of the 2.80 Mb chromosome of isolate v23.1.3. This region comprises (i) one 6980-bp full-sized Pholy element bordered by two 275- to 280-bp long terminal repeats (LTRs), (ii) five Pholy-related sequences, usually truncated at their 3' ends, and (iii) five solo-LTRs. Structural features strongly suggested that Pholy corresponds to an ancient copia-like retrotransposon, sharing strong homologies with the Elsa retrotransposon of Stagonospora nodorum. Pholy was also suggested to be specific to pericentromeric regions. Comparative analysis of the structure of the Pholy-like sequences occurring in the 184-kb contig and in other parts of the genome showed that this family of repeats is highly degenerated following extensive repeat induced point mutation (RIP).

Isolated liver metastasis from sacral chordoma. Case report and review of the literature

Chordoma is a rare malignant tumor derived from remnants of the primitive notochord. It can occur anywhere along the scull base and spine. The most commonly involved area is the sacrococcygeal region. Although chordomas invade adjacent structures, they metastasize less often. We present a case of a sacrococcygeal chordoma with liver metastasis. The nature and origin of the liver lesion was proved with fine-needle aspiration (FNA) under computed tomographic (CT) guidance.

New Avirulence Genes in the Phytopathogenic Fungus Leptosphaeria maculans

ABSTRACT Leptosphaeria maculans, the causal agent of stem canker of oilseed rape (Brassica napus), develops gene-for-gene interactions with oilseed rape, and four L. maculans avirulence (AVR) genes (AvrLm1, AvrLm2, AvrLm4, and alm1) were previously genetically characterized. Based on the analysis of progeny of numerous in vitro crosses between L. maculans isolates showing either already characterized or new differential interactions, this work aims to provide an overview of the AVR genes that may specify incompatibility toward B. napus and the related species B. juncea and B. rapa. Two novel differential interactions were thus identified between L. maculans and B. napus genotypes, one of them corresponding to a complete resistance to European races of L. maculans. In both cases, a single gene control of avirulence was established (genes AvrLm3 and AvrLm7). Similarly, a single gene control of avirulence toward a B. rapa genotype, also resistant to European L. maculans isolates, was demonstrated (gene AvrLm8). Finally, a digenic control of avirulence toward B. juncea was established (genes AvrLm5 and AvrLm6). Linkage analyses demonstrated that at least four unlinked L. maculans genomic regions, including at least one AVR gene cluster (AvrLm1-AvrLm2-AvrLm6), are involved in host specificity. The AvrLm3-AvrLm4-AvrLm7 region may correspond either to a second AVR gene cluster or to a multiallelic AVR gene.

Analysis of molecular markers genetically linked to the Leptosphaeria maculans avirulence gene AvrLm1 in field populations indicates a highly conserved event leading to virulence on Rlm1 genotypes

Map-based cloning of the avirulence gene AvrLm1 of Leptosphaeria maculans was initiated utilizing a genetic map of the fungus and a BAC library constructed from an AvrLm1 isolate. Seven polymorphic DNA markers closely linked to AvrLm1 were identified. Of these, two were shown to border the locus on its 5' end and were present, with size polymorphism, in both the virulent and the avirulent isolates. In contrast, three markers, J19-1.1, J53-1.3 (in coupling phase with avirulence), and Vir1 (in repulsion phase with avirulence), cosegregated with AvrLm1 in 312 progeny from five in vitro crosses. J19-1.1 and J53-1.3 were never amplified in the virulent parents or progeny, whereas Vir1 was never amplified in the avirulent parents or progeny. J19-1.1 and J53-1.3 were shown to be separated by 40 kb within a 184-kb BAC contig. In addition, the 1.6-cM genetic distance between J53-1.3 and the nearest recombinant marker corresponded to a 121-kb physical distance. When analyzing a European Union-wide collection of 192 isolates, J53-1.3, J19-1.1, and Vir1 were found to be closely associated with the AvrLm1 locus. The results of polymerase chain reaction amplification with primers for the three markers were in accordance with the interaction phenotype for 92.2% (J53-1.3), 90.6% (J19-1.1), and 88.0% (Vir1) of the isolates. In addition, genome organization of the AvrLm1 region was highly conserved in field isolates, because 89.1% of the avirulent isolates and 79.0% of the virulent isolates showed the same association of markers as that of the parents of in vitro crosses. The large-scale analysis of field isolates with markers originating from the genetic map therefore confirms (i) the physical proximity between the markers and the target locus and (ii) that AvrLm1 is located in (or close to) a recombination-deficient genome region. As a consequence, map-based markers provided us with high-quality markers for an overview of the occurrence of race "AvrLm1" at the field scale. These data were used to propose hypotheses on evolution towards virulence in field isolates.

Molecular characterisation and polymorphism of MinLm1, a minisatellite from the phytopathogenic ascomycete Leptosphaeria maculans

A sequence-characterised amplified region marker was identified in the phytopathogenic fungus Leptosphaeria maculans, which generated a single-banding pattern corresponding to six alleles showing size polymorphism between L. maculans field isolates. The size polymorphism was due to 2-7 tandem repeats of the 23-bp motif 5' TCTTACTTACATACACACCTCCC 3'. The repeated sequence, termed MinLm1, shares many features specific to minisatellites, e.g. a very strong G/C strand asymmetry, the presence of 6-bp direct repeats at both ends of the sequence and its occurrence in a region rich in microsatellites such as (CT)n, (ATG)n, (GTG)n and (CAT)n. MinLm1 shows a very high degree of conservation of the bases from one repeat to another and from one isolate to another (percent match range: 99.6-100%), whatever their geographical or temporal relatedness. MinLm1 is a single-locus minisatellite located on chromosomes sized 2.79 Mb and 2.48 Mb, of L. maculans isolates a.2 and H5, respectively. In agricultural populations of L. maculans, two alleles of MinLm1 were prevalent, corresponding to 2x and 5x repeats of the core motif. Differences in allele frequencies were observed in some cropping conditions, suggesting that MinLm1 is an informative marker for epidemiological studies of the pathogen.

Genetic Control and Host Range of Avirulence Toward Brassica napus Cultivars Quinta and Jet Neuf in Leptosphaeria maculans

ABSTRACT Leptosphaeria maculans causes blackleg of oilseed rape. Gene-for-gene interactions between race PG3 and Brassica napus cv. Quinta were related to interaction between the fungal avirulence (Avr) gene AvrLm1 and the corresponding resistance gene Rlm1. AvrLm1 isolates were aviru-lent on cvs. Doublol, Vivol, Columbus, and Capitol, and no recombinant phenotypes were observed in the progeny of two AvrLm1 x avrLm1 crosses, suggesting that all of these cultivars may possess Rlm1 or genes displaying the same recognition spectrum, or that a cluster of Avr genes is present at the Avrlm1 locus. In one cross, segregation distortion was observed at the AvrLm1 locus that could be explained by interaction between AvrLm1 and one unlinked deleterious gene, termed Del1. Incompatibility toward cvs. Jet Neuf and Darmor.bzh was governed by a single gene, unlinked to AvrLm1 or Del1. This avirulence gene was termed AvrLm4. Preliminary plant genetic analysis suggested the occurrence of a corresponding dominant resistance gene, termed Rlm4, present in the Quinta line analyzed and linked to Rlm1.

Extended preservation of the liver with UW solution--is it justifiable?

The outcome of 228 liver grafts in 208 elective adult recipients was assessed to identify any adverse effects of extending the length of cold preservation with UW solution beyond 12 hr. A total of 114 grafts had been preserved < 12 hr--median 9.5 (group I) and 114 > 12 hr--median 14.5 (group II). Intraoperative blood and blood product usage, graft function, hospital stay, and graft and patient survival were identical in the two groups. Biliary strictures occurred in 5.7% of grafts (8 anastomotic (3 group I, 5 group II; 5 hilar/nonanastomotic: 3 group I, 2 group II). There was no graft or patient loss due to the hilar strictures but 1 patient died following reconstruction of an anastomotic stricture (0.4%). It is concluded that extending the cold preservation to approximately 15 hr does not adversely affect outcome after liver transplantation.

Can effluent hyaluronic acid or creatine kinase predict sinusoidal injury severity after cold ischemia?

It is well recognized that current selection criteria used to assess liver grafts before implantation are inaccurate and correlate poorly with graft outcome. A bench or laboratory-based test that could indicate the extent of liver injury immediately before implantation would be a valuable adjunct to clinical assessment. Hyaluronic acid (HA) and creatine kinase (BB component; CK-BB) levels in the caval effluent after liver perfusion have been suggested as indicators of preservation injury. Our objective was to investigate the relevance of preserved liver effluent HA and CK-BB as a predictor of early graft function. Perfused liver effluent HA and CK-BB levels were measured. Graft function was measured in terms of peak serum aspartate transaminase and its level on day 5 postoperatively as well as peak bilirubin level and prothrombin time. The cold ischemia time (CIT) was recorded. Statistical comparisons were made among HA level, CK-BB level, CIT, and graft function parameters. The study was conducted at The Liver and Hepatobiliary Unit, Queen Elizabeth Hospital, Birmingham, United Kingdom. Fifty patients undergoing OLT were studied. HA level was measured in 50 patients and CK-BB level in 30 patients. The main outcome measures were graft function and graft outcome. The graft function data are grouped according to effluent HA levels above or below 400 micrograms/L. Thirteen patients (26%) had a level below 400 micrograms/L and the remaining 37 (74%) were above this threshold. There were no significant differences between the groups for these indicators of graft function. There was no difference between the 2 groups for CIT. The overall median HA level was 1212 micrograms/L (range 39-4000 micrograms/L). The median total CK activity in the perfusate was 302 IU/L (range 118-1155 IU/L). The proportion of CK-BB activity from this total was 146 IU/L (8-641 IU/L), or 48% of the total CK activity. In a multiple regression analysis with CK-BB activity as the dependent variable, there was no demonstrable numerical relationship to graft function. In a separate multiple regression analysis similar results were obtained for HA. We conclude that the level of HA or CK-BB levels should not be used in determining the suitability for implantation of a harvested hepatic allograft.

A multicentre controlled clinical trial of high-volume fresh frozen plasma therapy in prognostically severe acute pancreatitis

Fresh frozen plasma (FFP) has been proposed as a specific therapy for acute pancreatitis. It may replenish important circulating proteins, particularly the naturally occurring anti-protease system. To investigate this potential therapy, 72 patients with predicted severe disease were selected from 301 admissions with acute pancreatitis using the modified Glasgow prognostic scoring system. They were randomised within 6 h of diagnosis to receive FFP (8 units daily for 3 days) or a similar volume of colloid control as part of their intravenous fluid therapy. Clinical progress was monitored and specific blood proteins were measured on days 1, 3 and 7. FFP therapy significantly increased the day 3 concentrations of some of the acute phase proteins (C1-reactive protein P less than 0.02, D-dimer P less than 0.05 and fibrinogen P less than 0.05) as well as some proteins which showed a fall in circulating concentration during the early stages of the disease (alpha 2 macroglobulin P less than 0.001, antithrombin III P less than 0.01 and fibronectin P less than 0.001). However, there was no significant difference between the two groups in terms of clinical outcome. Mortality was 20% in patients who received FFP and 18% in the colloid control group. Despite the ability of FFP therapy to supplement circulating concentrations of several potentially useful proteins during acute pancreatitis, it does not appear to improve clinical outcome.

Melanin in the inner ear. An experimental study with control and kanamycin-intoxicated colored guinea-pigs

Following several studies on the effects of kanamycin toxicity on the inner ears of guinea pigs, we have studied the importance of melanin in this phenomenon. Transmission electron microscopy showed that, under the influence of kanamycin, the intermediate strial cells developed a secretory aspect similar to that seen in skin melanocytes. This aspect as yet has never been described for the inner ear cells. A planimetric, morphometric method was also used to determine the strial cell melanin status in control animals. Additional findings in the study confirmed an increase in the number of melanosomes during kanamycin poisoning. Statistical data are discussed.

Melanine value in the stria vascularis of pigmented guinea-pigs treated by kanamycin

In a previous report, kanamycin (400 mg/kg/d) seemed to increase the number of melanine granulations in intermediate cells of the stria vascularis, especially in the second and third turns. To precise these data, melanine was studied in those turns by ultrastructural morphometry in a control group with 12 animals. We observed a large intra-individual and inter-individual variation before intoxication. Thus, the meaning of melanine modifications by kanamycin must be carefully evaluated.