Tumour response 3 months after neoadjuvant single-fraction radiotherapy for low-risk breast cancer.

Introduction: Standard treatment for early-stage invasive breast cancer (bca) consists of breast-conserving surgery and several weeks of adjuvant radiotherapy (rt). Neoadjuvant single-fraction rt is a novel approach for early-stage bca. We sought to investigate the effect of delaying surgery after neoadjuvant rt with respect to the rate of pathologic response (pr). Methods: Women 65 years of age or older with a new diagnosis of stage i luminal A bca were eligible for inclusion. A single 20 Gy dose to the primary breast tumour was given, followed by breast-conserving surgery 3 months later. The primary endpoint was the pr rate assessed by microscopic evaluation using the Miller-Payne system. Results: To date, 10 patients have been successfully treated. Median age of the patients was 72 years (range: 65-84 years). In 8 patients, neoadjuvant rt resulted in a tumour pr with median residual cellularity of 3%. No immediate rt complications other than mild dermatitis were noted. Conclusions: This study demonstrates a method for delivering single-fraction rt that can lead to a high level of pr in most patients. Continued accrual to this study and subsequent trials are needed to determine the feasibility, safety, and role of this novel technique in the management of early-stage bca.

The E3 ubiquitin ligase TRIP12 participates in cell cycle progression and chromosome stability.

Several studies have linked the E3 ubiquitin ligase TRIP12 (Thyroid hormone Receptor Interacting Protein 12) to the cell cycle. However, the regulation and the implication of this protein during the cell cycle are largely unknown. In this study, we show that TRIP12 expression is regulated during the cell cycle, which correlates with its nuclear localization. We identify an euchromatin-binding function of TRIP12 mediated by a N-terminal intrinsically disordered region. We demonstrate the functional implication of TRIP12 in the mitotic entry by controlling the duration of DNA replication that is independent from its catalytic activity. We also show the requirement of TRIP12 in the mitotic progression and chromosome stability. Altogether, our findings show that TRIP12 is as a new chromatin-associated protein with several implications in the cell cycle progression and in the maintenance of genome integrity.

Forensic analysis of latent fingermarks by silver-assisted LDI imaging MS on nonconductive surfaces.

Silver-assisted laser desorption ionization (AgLDI) imaging mass spectrometry (IMS) has been demonstrated to be a useful technology for fingermark analysis allowing for the detection of several classes of endogenous as well as exogenous compounds. Ideally, in IMS analyses, the fingermarks are deposited under controlled conditions on metallized conductive target slides. However, in forensic investigations, fingermarks are often found on a variety of nonconductive surfaces. A sputtered silver layer renders the target surface conductive, which allows the analyses of insulating surfaces by time-of-flight IMS. Ultimately, the major consideration when developing analytical methods for the analysis of latent fingermarks is their capability to be incorporated within forensic standard operational procedures. To demonstrate the potential of AgLDI IMS for forensic applications, fingermarks deposited on nonconductive surfaces commonly found during an investigation, including paper, cardboard, plastic bags and lifting tape, were first revealed by the Sûreté du Québec by using forensic enhancement techniques prior to the IMS analyses. Numerous endogenous compounds including fatty acids, cholesterol, squalene, wax esters, triglycerides and several exogenous substances were detected and imaged. Here, we show that silver sputtering can provide visual enhancements of fingerprint patterns after FET procedures through different scenarios in which AgLDI IMS can contribute to forensic investigations. Copyright © 2017 John Wiley & Sons, Ltd.

Assessing the Potential of Metal-Assisted Imaging Mass Spectrometry in Cancer Research.

In the last decade, imaging mass spectrometry (IMS) has been the primary tool for biomolecular imaging. While it is possible to map a wide range of biomolecules using matrix-assisted laser desorption/ionization IMS ranging from high-molecular-weight proteins to small metabolites, more often than not only the most abundant easily ionisable species are detected. To better understand complex diseases such as cancer more specific and sensitive methods need to be developed to enable the detection of lower abundance molecules but also molecules that have yet to be imaged by IMS. In recent years, a big shift has occurred in the imaging community from developing wide reaching methods to developing targeted ones which increases sensitivity through the use of more specific sample preparations. This has been primarily marked by the advent of solvent-free matrix deposition methods for polar lipids, chemical derivatization for hormones and metabolites, and the use of alternative ionization agents for neutral lipids. In this chapter, we discuss two of the latest sample preparations which exploit the use of alternative ionization agents to enable the detection of certain classes of neutral lipids along with free fatty acids by high-sensitivity IMS as demonstrated within our lab.

Mesocortical dopamine depletion and anxiety-related behavior in the rat: sex and hemisphere differences.

The mesocortical dopamine (DA) system of the rat plays an important role in prefrontal cortex (PFC) regulation of stress and emotion and exhibits functional hemispheric asymmetry for such processing. Since few studies examine sex differences in this context, we compared the effects of left vs. right unilateral PFC DA depletion in males and females in several behavioral situations associated with anxiety or aversion. Adult rats received unilateral injections of 6-hydroxydopamine (6-OHDA) or vehicle in the ventromedial (vm) PFC. Behavioral tests included a predator odor burying test, elevated plus maze and sucrose consumption with simple taste aversion. Tissue analysis confirmed that vmPFCs injected with 6-OHDA were depleted of DA (75-85%) compared to controls. Burying behavior and sucrose consumption were affected only by left lesions, similarly in both sexes. However, risk assessment behaviors were affected by right lesions in opposite directions in males and females. Behaviors modified preferentially by the left cortex thus showed less evidence of sex differences than those modulated by the right. While mesocortical DA depletion effects are lateralized, the nature of these effects can vary with sex and specific behavior. Such findings may be clinically significant, given the large gender differences in the incidence of mood and anxiety disorders, which also show many lateralized prefrontal abnormalities.

Role of sex in the neurochemical and neuroendocrine correlates of paw preference in the rat.

Handedness in humans and paw preference (PP) in rodents have been associated with neural and physiological correlates, which frequently appear to be sex-specific. The present study examines sex differences in the effects of differential PP on post mortem measures of regional monoamine activity in adult Long-Evans rats. The effects of PP on neuroendocrine function were also assessed by measuring plasma adrenocorticotropic hormone (ACTH) in response to a 30-min restraint stress. Most rats showed strong individual PP. Males (n=27) and females (n=26) did not differ in the direction or strength of their PP with nearly equal numbers of left and right-pawed rats. However, many Sex×PP interactions were noted in regional neurochemical measures, and most effects of PP were bilateral in nature and sex-specific. In males, Left PP (relative to Right PP) was associated with reduced striatal dopamine (DA) levels and amygdala DA metabolism bilaterally. In females, Left PP was associated with a bilateral upregulation of DAergic metabolism in both prefrontal cortex and nucleus accumbens, increased amygdala serotonin metabolism, and a (right) unilateral increase in amygdala DA. As in previous studies, some correlations were also noted between PP and asymmetrical or unilateral monoamine measures. As well, rats with strong PP, independent of direction or sex, had lower basal ACTH and more robust stress responses than rats with weak PP, suggesting a possible adaptive advantage to strong lateralization. Overall, sex differences were found only regarding effects of the direction of PP, not its magnitude. The findings suggest that the direction of PP affects distinct bilateral networks of structures sex-dependently. Such fundamental influences of PP on functional brain organization have implications for a wide array of processes under monoaminergic modulation in these brain regions, and may further our understanding of the numerous human examples of gender and handedness interactions across several modalities.

TP53INP1 decreases pancreatic cancer cell migration by regulating SPARC expression.

Tumor protein 53 induced nuclear protein 1 (TP53INP1) is a p53 target gene that induces cell growth arrest and apoptosis by modulating p53 transcriptional activity. TP53INP1 interacts physically with p53 and is a major player in the p53-driven oxidative stress response. Previously, we demonstrated that TP53INP1 is downregulated in an early stage of pancreatic cancerogenesis and when restored is able to suppress pancreatic tumor development. TP53INP1 downregulation in pancreas is associated with an oncogenic microRNA miR-155. In the present work, we studied the effects of TP53INP1 on cell migration. We found that TP53INP1 inactivation correlates with increased cell migration both in vivo and in vitro. The impact of TP53INP1 expression on cell migration was studied in different cellular contexts: mouse embryonic fibroblast and different pancreatic cancer cell lines. Its expression decreases cell migration by the transcriptional downregulation of secreted protein acidic and rich in cysteine (SPARC). SPARC is a matrix cellular protein, which governs diverse cellular functions and has a pivotal role in regulating cell-matrix interactions, cellular proliferation and migration. SPARC was also showed to be upregulated in normal pancreas and in pancreatic intraepithelial neoplasia lesions in a pancreatic adenocarcinoma mouse model only in the TP53INP1-deficient animals. This novel TP53INP1 activity on the regulation of SPARC expression could explain in part its tumor suppressor function in pancreatic adenocarcinoma by modulating cellular spreading during the metastatic process.

Impact of alginate type and bead diameter on mass transfers and the metabolic activities of encapsulated C3A cells in bioartificial liver applications.

Liver-assist devices have been developed in the last few decades to support patients with liver failure on the road to recovery or transplantation. Fluidised bed bio-artificial livers--where liver cells are encapsulated within alginate beads--appear to be a valuable alternative to hollow fibre devices for improving mass transfers and enhancing treatment efficacy. This approach nevertheless deserves optimization in terms of bead production. The aim of this study was to investigate the impact of alginate type and of two bead diameters (1000 µm and 600 µm) on mass transfers within beads and on the biological functions of encapsulated C3A cells. After assessing the effect of the encapsulation process on bead quality, we investigated cell viability and metabolic activities (ammonia, albumin, alpha-fetoprotein synthesis and glucose consumption). They were successfully maintained over 48 h within fluidised bed bioreactors, independently of alginate type and bead diameter. Mass transfers were not significantly influenced by the latter parameters. Finally, suggestions are made for improving the entrapment process as a means of enhancing the treatment efficiency of the fluidised bed bioartificial liver.

Comparative sensitivity of harbour and grey seals to several environmental contaminants using in vitro exposure.

In this study, we investigated the effects of cadmium chloride (CdCl(2)), mercury chloride (HgCl(2)), methylmercury chloride (CH(3)HgCl), and PCBs on lymphocyte proliferation in phocids. PBMCs isolated from harbour and grey seals were exposed in vitro to varying concentrations of contaminants. A reduction of viability occurred when cells were exposed to 10(-4)M HgCl(2) or CH(3)HgCl or to 50ppm of Aroclor 1254. In both grey and harbour seals, T-lymphocyte proliferation was suppressed when their cells were incubated with 5 x 10(-5)M CdCl(2) or 10(-4)M HgCl(2). An inhibition of proliferation occurred with CH(3)HgCl from 10(-6)M in grey seals and from 10(-5)M in harbour seals. In grey seals, Aroclor 1254 reduced lymphocyte proliferation at 15ppm. In both harbour and grey seals, CH(3)HgCl was ten times more immunotoxic that HgCl(2). From IC(50), chemicals were ranked in terms of toxicity as followed: CH(3)HgCl>CdCl(2)>HgCl(2)>Aroclor 1254.

The place of adsorption and biochromatography in extracorporeal liver support systems.

Artificial and bioartificial liver devices aim at replacing some or all liver functions in the cases of end stage or fulminant disorders. Among all of its function, liver plays a key role in detoxification of substances that are hydrosoluble or bound to albumin. In this paper, the authors first reviewed the requirements for temporary liver support, then the adsorption-based systems that can be found on the market and finally propose new applications of biochromatography using perfusion-based bioartificial systems.

Reg genes are CCK2 receptor targets in ElasCCK2 mice pancreas.

We previously demonstrated that expression of the gastrin receptor, CCK2R, in pancreatic acini of transgenic ElasCCK2 mice induced alteration of acinar morphology and differentiation, increased sensitivity to a carcinogen and development of preneoplastic lesions and tumours. Reg proteins are suggested to be involved in pancreatic cancer and in regeneration of endocrine pancreas. Reg I gene is a known target of gastrin. We examined whether an expression of CCK2R in the pancreatic acini of ElasCCK2 mice is linked to induction of Reg proteins expression. We analyzed Reg expression by Western-blot and immunohistochemistry in pancreas from ElasCCK2 and control mice. Islet neogenesis, glucose homeostasis, insulin secretion and content were also evaluated. Reg I is exclusively produced in acini in ElasCCK2 and control mice. In tumoral pancreas, Reg I and Reg III proteins are expressed in duct-like cells in preneoplastic lesions or in the periphery of tumours and in adjacent acini. The expression of Reg III proteins is increased in ElasCCK2 pancreas before the development of preneoplastic lesions in a subpopulation of islet cells and in small islet-like cell clusters dispersed within the acinar tissue. Several criteria of an enhanced neogenesis are fulfilled in ElasCCK2 pancreas. Moreover, ElasCCK2 mice have an improved response to glucose load, an increased insulin secretion and a doubling of insulin content compared to control mice. We show that Reg proteins are targets of CCK2R activation and are induced during early steps of carcinogenesis in ElasCCK2 mice pancreas. Alterations of exocrine tissue homeostasis in ElasCCK2 pancreas concomitantly activate regenerative responses of the endocrine pancreas possibly linked to paracrine actions of Reg III proteins.

Interactions of B16F10 melanoma cells aggregated on a cellulose substrate.

There is evidence that the shape of cells and their contact with a matrix direct the growth and the differentiation of both normal and cancer cells. Cells in 3D culture resemble the in vivo situation more closely than do those in conventional 2D cultures. We have studied the interactions and functions of B16F10 mouse melanoma cells, which spread and grow well on tissue culture polystyrene (tPS), when they were made to aggregate on cellulose-coated Petri dishes (CEL). This aggregation of melanoma cells on CEL was Ca2+ dependent and mediated by N-cadherins. The levels of N-cadherin and beta-catenin transcripts in cells cultured on CEL and tPS were similar, but those on CEL contained less beta-catenin protein. Immunoprecipitation and immunostaining showed that both N-cadherins and beta-catenins were present at the membranes of cells on CEL. Cells proliferated significantly more slowly after 48 h on CEL and the cellulose coating caused most of them to arrest in G1. We also compared the melanin contents and tyrosinase activity of cells on CEL and controls grown on tPS. Melanogenesis was induced in cells aggregated on CEL. A cellulose substrate thus appears to be an outstanding tool for studying cell-cell interactions and cell functions in 3D cultures.

Cholecystokinin-2 receptor modulates cell adhesion through beta 1-integrin in human pancreatic cancer cells.

Several lines of evidence suggest that gastrin and the CCK-2 receptor (CCK2R) could contribute to pancreatic carcinogenesis by modulating processes such as proliferation, cell adhesion or migration. In the current study, we used a 'cancer gene array' and identified beta1-integrin subunit as a new gastrin-regulated gene in human pancreatic cancer cells. We also demonstrated that Src family kinases and the phosphatidylinositol-3-kinase (PI-3-kinase) pathway play a crucial role in the expression of beta1-integrin induced by gastrin. Our results also showed that gastrin modulates cell-substrate adhesion via beta1-integrin. Indeed, using blocking anti-beta1-integrin monoclonal antibodies, we completely reversed the increase in cell-substrate adhesion induced by gastrin. In addition, we observed that in response to gastrin, beta1-integrin is tyrosine phosphorylated by Src family kinases and associates with paxillin, a scaffold protein involved in focal adhesion and integrin signalling. This mechanism might be involved in gastrin-induced cell adhesion. Moreover, we showed in vivo that targeted CCK2R expression in the pancreas of Elas-CCK2 mice leads to the overexpression of beta1-integrin. This process may contribute to pancreatic tumour development observed in these transgenic animals.

Renal allograft tolerance in DLA-identical and haploidentical dogs after nonmyeloablative conditioning and transient immunosuppression with cyclosporine and mycophenolate mofetil.

BACKGROUND: Canine models of bone marrow and renal transplantation have provided important preclinical data relevant to developing novel therapeutic protocols for hematopoietic and solid organ transplantation in human beings. Nonmyeloablative transplantation has been shown to induce stable mixed hematopoietic chimerism in normal dogs and correct the phenotype of canine pyruvate kinase deficiency and Glanzman's thrombasthenia. In this study, we investigated the potential for inducing renal allograft tolerance using a nonmyeloablative bone marrow transplantation strategy that induces mixed chimerism in DLA-identical dogs. METHODS: Reciprocal renal allografts were performed in 4 DLA-identical and 4 DLA-haploidentical dogs with nonmyeloablative conditioning (200 cGy total body irradiation [TBI]) and transient immunosuppression with cyclosporine (CSP) and mycophenolate mofetil (MMF) with and without simultaneous bone marrow transplantation. Two DLA-identical control dogs received reciprocal renal allografts without TBI or immunosuppression with CSP and MMF. Serum creatinine (Cr) concentration was monitored to assess renal allograft function. RESULTS: The renal allografts were acutely rejected in the 2 DLA-identical dogs without TBI or immunosuppression. There was long-term (>1 year) renal allograft survival as evidenced by a normal (<2.0 mg/dL) serum Cr concentration in both the DLA-identical and DLA-haploidentical dogs that underwent 200 cGy TBI and transient immunosuppression with CSP and MMF either with or without simultaneous bone marrow transplantation. CONCLUSIONS: Nonmyeloablative conditioning (200 cGy TBI) and transient immunosuppression with CSP and MMF induce renal allograft tolerance in DLA-identical and DLA-haploidentical dogs without donor/host mixed hematopoietic chimerism. These findings suggest it may be possible to induce tolerance to solid organ transplants without the need for chronic immunosuppressive therapy or stable hematopoietic chimerism in the setting of both DLA-matched and haploidentical transplants.

Preparation and characterization of water-soluble pH-sensitive nanocarriers for drug delivery.

pH-sensitive drug delivery systems can be engineered to release their contents or change their physicochemical properties in response to variations in the acidity of the surroundings. The present work describes the preparation and characterization of novel polymeric micelles (PM) composed of amphiphilic pH-responsive poly(N-isopropylacrylamide) (PNIPAM) or poly(alkyl(meth)acrylate) derivatives. On one hand, acidification of the PNIPAM copolymers induces a coil-to-globule transition that can be exploited to destabilize the intracellular vesicle membranes. In this work, PNIPAM-based PM were loaded with either doxorubicin or aluminium chloride phthalocyanine and their cytotoxicity was assessed in murine tumoral models. On the other hand, poly(alkyl(meth)acrylate) copolymers can be designed to interact with either hydrophobic drugs or polyions and release their cargo upon an increase in pH.

clap1, a gene encoding a copper-transporting ATPase involved in the process of infection by the phytopathogenic fungus Colletotrichum lindemuthianum.

A screen for insertional mutants of Colletrichum lindemuthianum, the causative agent of common bean anthracnose, led to the identification of a non-pathogenic, lightly colored transformant. This mutant is unable to induce disease symptoms on intact or wounded primary leaves of seedlings and plantlets of Phaseolus vulgaris. In vitro, it exhibits normal vegetative growth, sporulation and conidial germination, but the cultures remain beige instead of becoming black. Microscopic examination revealed that this mutant forms fewer appressoria than the wild-type strain, and these are misshapen and poorly melanized. Molecular analyses indicated that the mutagenic plasmid had targeted clap1, a gene encoding a putative copper-transporting ATPase sharing 35% identity with the human Menkes and Wilson proteins and the product of the CCC2 gene of Saccharomyces cerevisiae. Complementation of the non-pathogenic beige mutant with a wild-type allele of clap1 restored both pathogenicity and pigmentation. Conversely, replacement of the wild-type allele with a disrupted clap1 gene gave rise to non-pathogenic beige transformants. Compared with the wild-type strain, extracts from clap1 mutants were found to have very low levels of phenol oxidase activity. These observations suggest that the clap1 gene product may be involved in the pathogenicity of C. lindemuthianum strains because of its role in delivering copper to secreted cuproenzymes, such as the phenol oxidases that mediate the polymerization of 1,8-dihydroxynaphthalene to melanin.

Organization of cyclic AMP-dependent connexin 43 in Swiss 3T3 cells attached to a cellulose substratum.

We have previously shown that the adenylyl cyclase, which produces cyclic AMP (cAMP) in Swiss 3T3 cells, is activated by their attachment to a cellulose substratum (Cuprophan, CU). This substratum adsorbs vitronectin poorly, prevents cell spreading and causes them to aggregate. By contrast, cells spread out on polystyrene and contain low concentrations of cAMP. We have found that Connexin 43 (Cx 43) gap junction plaques are involved in this cell aggregation. MDL 12330 A, a specific inhibitor of adenylyl cyclase, prevented cell aggregation on CU and abolished Cx 43 channel clustering. But forskolin, a direct activator of adenylyl cyclase, and SBr cAMP, a cell-permeable analogue of cAMP, caused Cx 43 channel clustering in cells attached to polystyrene. Hence, Cx 43 channel clustering is regulated by cAMP in Swiss 3T3 cells. In addition, neither brefeldin A nor monensin (inhibitors of transit through the endoplasmic reticulum and Golgi apparatus), abolished Cx 43 channel clustering in cells aggregated on CU. Thus, the Cx 43 that form clusters in cells attached to CU are not dependent upon the trafficking of Cx 43 from intracellular storage sites, but are probably reorganised from the plasma membrane.

Relationship between pre-TIPS liver perfusion by the portal vein and the incidence of post-TIPS chronic hepatic encephalopathy.

OBJECTIVE: In the present study we evaluated the predictive value of pretransjugular intrahepatic portosystemic shunt (TIPS) portal perfusion as assessed by Doppler ultrasonography for the onset of chronic encephalopathy after TIPS. METHODS: A total of 231 cirrhotic patients were followed-up prospectively after TIPS placement. The pattern of intrahepatic portal flow was assessed before TIPS. Patients were divided into two groups according to Doppler findings. Group 1 comprised patients with prograde portal flow (n = 200), whereas group 2 comprised those with loss of portal perfusion (hepatofugal or back-and-forth flow or portal vein thrombosis; n = 31). The presence of chronic encephalopathy during a median follow-up of 32 months was prospectively recorded. The prognostic value of the following parameters for the onset of chronic recurrent encephalopathy after TIPS was evaluated: age, presence of encephalopathy before TIPS, alcoholism, Pugh score, and loss of portal perfusion before TIPS. The independent prognostic value of each variable was tested with a multiple logistic regression analysis. RESULTS: The two groups were comparable in terms of age, incidence of prior episodes of hepatic encephalopathy, and portacaval gradient before and after the procedure; however, liver failure was more severe in patients in group 2 (Pugh score: 9.2 +/- 1.9 vs 10.3 +/- 1.7). The 3-yr survival was identical for both groups; 25% of the 200 patients in group 1 developed chronic encephalopathy as compared to 6% of the 31 patients in group 2 (p = 0.03). Multiple logistic regression analysis demonstrated that loss of portal perfusion and age >65 yr were the only independent predictors of the onset of post-TIPS chronic encephalopathy (odds ratios 0.24 and 1.98, respectively). CONCLUSIONS: Cirrhotic patients with loss of portal perfusion before TIPS were protected against post-TIPS chronic hepatic encephalopathy despite a more severe liver dysfunction at baseline. The only other independent predictive factor for the onset of this complication was age.

Arterial embolotherapy for upper gastrointestinal hemorrhage: outcome assessment.

PURPOSE: To identify predictors of clinical outcome after arterial embolotherapy for upper gastrointestinal (UGI) hemorrhage. MATERIALS AND METHODS: Seventy-five consecutive patients (mean age, 62.5 y) underwent arterial embolization for acute UGI hemorrhage. Bleeding was detected at endoscopy and angiography in 22 patients, at endoscopy alone in 29 patients, and at angiography alone in 24 patients. As such, embolization was directed by angiography in 46 patients (61.3%) and by endoscopy (referred to as "blind" embolization) in 29 patients (38.7%). The embolic agents used were metallic coils, polyvinyl alcohol particles (size range, 355-710 microm), gelatin sponge, and tissue adhesive. Predictors of bleeding recurrence and mortality were analyzed with logistic regression and Cox models, respectively. RESULTS: The technical success rate of embolization was 98.7%. Primary clinical success was achieved in 57 patients (76%). Secondary clinical success occurred in five additional patients (82.5%) after repeat embolization. There were four (5.3%) complications: two cases of self-resolving duodenal ischemia, one hepatic infarct, and one inguinal hematoma. The periprocedural mortality rate was 34.6% (26 of 75), mostly related to underlying illness. Early recurrence of bleeding (within 30 days of embolization) was associated with coagulation disorders (international normalized ratio >1.5, partial thromboplastin time >45 seconds, or platelet count <80,000/microL; odds ratio, 19.46; P = .001) and with the use of coils as the only embolic agent (odds ratio, 7.73; P = .01). Cirrhosis and cancer shortened the overall survival of patients after embolic therapy. The mean patient follow-up time was 34.5 months. CONCLUSION: Arterial embolotherapy for UGI hemorrhage is safe, effective, and durable. Coagulopathy and the use of coils as the only embolic agent were associated with a higher risk of early bleeding recurrence.

Definition of tissue-specific and general requirements for plant infection in a phytopathogenic fungus.

Although plant diseases are usually characterized by the part of the plant that is affected (e.g., leaf spots, root rots, wilts), surprisingly little is known about the factors that condition the ability of pathogens to colonize different plant tissues. Here we demonstrate that the leaf blast pathogen Magnaporthe grisea also can infect plant roots, and we exploit this finding to distinguish tissue-specific and general requirements for plant infection. Tests of a M. grisea mutant collection identified some mutants that were defective specifically in infection of either leaves or roots, and others such as the map kinase mutant pmk1 that were generally defective in pathogenicity. Conservation of a functional PMK1-related MAP kinase in the root pathogen Gaeumannomyces graminis was also demonstrated. Exploitation of the ability of M. grisea to infect distinct plant tissues thus represents a powerful tool for the comprehensive dissection of genetic determinants of tissue specificity and global requirements for plant infection.