Identification of single nucleotide polymorphisms (SNPs) for maize cell wall hydroxycinnamates using a multi-parent advanced generation intercross (MAGIC) population

Higher hydroxycinnamate content makes maize tissues more recalcitrant to damage by insects, less digestible by ruminants, and less suitable for biofuel production. In a Genome Wide Association Analysis (GWAS) study carried out in a maize MAGIC population, we identified 24 SNPs associated with esterified cell wall-bound hydroxycinnamates, that represented 15 Quantitative Traic Loci (QTL). We identified new genomic regions associated to cell wall bound hydroxycinnamates in maize stover that could have an impact on their content across different genetic backgrounds. The high resolution QTL described in this study could be valuable for addressing positional mapping of genes involved in hydroxycinnamate biosynthesis and could uncover genes implicated in the esterification of hydroxycinnamic acids to the arabinoxylan chains that are poorly understood. However, we found that genetic correlation coefficients between hydroxycinnamate content and economical important traits such as saccharification efficiency, animal digestibility andi pest resistance were low to moderate, so modify specific hydroxycinnamates to indirectly improve cultivar performance will be unsuitable.

Coronary perforations and its clinical impact during CTO recanalization: a 2054 patients pooled analysis from the Latin American (LATAM) CTO registry

Introduction

Percutaneous coronary intervention (PCI) of chronic total occlusions (CTO) are the most challenging procedures and still associated with the highest complications rates. Coronary perforation is a life-threatening acute PCI complication, but data are limited regarding its impact on mid-term outcome. We aimed to assess 30-days and 1-year outcomes in CTO PCI patients with coronary perforations.

Purpose

Analyze the clinical impact of Cto perforations during CTO PCI at short and mid-term in a muticenter continental registry in Latin America (LATAM).

Methods

We analyzed data from the continental multicenter Latin America CTO Registry including patients who underwent CTO PCI in 57 centers from 9 countries. Coronary perforation during the index procedure were categorized according to Ellis classification. We assessed 30-days adverse events and 1-year major adverse cardiac and cerebrovascular (MACCE) defined as the composite of all-cause death, myocardial infarction (MI), target vessel revascularization and stroke. MI was defined according both the LATAM CTO protocol and SCAI definitions.

Results

From January 2015 to October 2018, 2054 patients underwent CTO PCI. The median J-CTO score was 2.0 (1.0–3.0) and the median Progress score was 1.0 (0.0–2.0). The overall perforation rate was 3.7% (n=76) in which 55% were Ellis class 1, 24% Ellis class 2 and 21% Ellis class 3. No differences were found in any baseline clinical characteristics. Patients with perforation had more frequently retrograde instrumentation (P<0.01) and antegrade knuckle wire (P<0.01) and lower success rate (P<0.01). At 30-days, perforations were associated with more heart failure (6.6% vs 1.5%, p<0.01), bleeding (15.2% vs 3.7%, p<0.01), transfusion (7.9% vs 1.1%, p<0.01) and cardiac tamponade (13.2% vs 0.4%, p<0.01). After 1-year follow-up, patients with perforations had higher MACCE rates according to both LATAM CTO protocol (18.2 vs. 9.4%; P=0.02) and SCAI definitions (22.7% vs. 11.3%; P<0.01).

Conclusions

In this multicenter continental real-world analysis, coronary perforation in CTO PCI was infrequent and was related with higher anatomical and procedural complexity characteristics. Despite the similarity in clinical characteristics, patients that had coronary perforation were exposed to an increased risk of both hemorrhagic and ischemic events.

Funding Acknowledgement

Type of funding sources: None.

Comparison of T1-weighted turbo spin echo and out-of-phase T1-weighted gradient echo Dixon MRI for the assessment of intra-medullary length of appendicular bone tumours

OBJECTIVE

Intra-medullary tumour length is accurately assessed on T1-weighted turbo spin echo (T1W TSE) MRI which can be relatively time consuming, whilst the gradient echo Dixon (T1W GrE Dixon) technique is a rapid sequence (imaging time ~ 30 s). The aim of this study was to determine if the out-of-phase Dixon (OP T1W GrE Dixon) sequence can produce equivalent measurements of intra-medullary tumour length compared to the T1W TSE sequence.

MATERIALS AND METHOD

Tumour length was assessed in 90 patients undergoing MRI for staging of primary bone tumours with both T1W TSE and OP T1W GrE Dixon MRI sequences at 3 T (n = 42) and 1.5 T (n = 48). Tumour length was measured independently by different observers allowing assessment of inter-observer correlation, and the correlation between measurements on T1W TSE and OP T1W GrE Dixon sequences was also determined.

RESULTS

There were 53 males and 37 females (mean age 36.4 years; range 2-77 years). Inter-observer correlation for tumour length on both the T1W TSE and T1W OP GrE Dixon sequences was very good (ICC = 0.94-0.98), and measurement of tumour length comparing T1W TSE and T1W GrE Dixon was also very good (ICC = 0.91-0.99). In 4 cases, tumour length was significantly overestimated on T1W TSE images due to extensive reactive marrow oedema, but more accurately determined on the OP sequence when compared to resection specimens.

CONCLUSIONS

The OP T1W GrE Dixon sequence is comparable to T1W TSE for assessment of the intra-medullary length of appendicular bone tumours, and more accurate in the presence of extensive reactive marrow oedema.

Association mapping for maize stover yield and saccharification efficiency using a multiparent advanced generation intercross (MAGIC) population

Cellulosic ethanol derived from fast growing C4 grasses could become an alternative to finite fossil fuels. With the potential to generate a major source of lignocellulosic biomass, maize has gained importance as an outstanding model plant for studying the complex cell wall network and also to optimize crop breeding strategies in bioenergy grasses. A genome-wide association study (GWAS) was conducted using a subset of 408 Recombinant Inbred Lines (RILs) from a Multi-Parent Advanced Generation Intercross (MAGIC) Population in order to identify single nucleotide polymorphisms (SNPs) associated with yield and saccharification efficiency of maize stover. We identified 13 SNPs significantly associated with increased stover yield that corresponded to 13 QTL, and 2 SNPs significantly associated with improved saccharification efficiency, that could be clustered into 2 QTL. We have pointed out the most interesting SNPs to be implemented in breeding programs based on results from analyses of averaged and yearly data. Association mapping in this MAGIC population highlight genomic regions directly linked to traits that influence the final use of maize. Markers linked to these QTL could be used in genomic or marker-assisted selection programs to improve biomass quality for ethanol production. This study opens a possible optimisation path for improving the viability of second-generation biofuels.

Design and synthesis of alverine-based ionic liquids to improve drug water solubility

Alverine [3-phenyl-N-(3-phenylpropyl)-N-ethylpropan-1-amine] is a widely known smooth muscle relaxant used to relieve cramps or spasms of the stomach and intestines.

Genome-wide association analysis for maize stem Cell Wall-bound Hydroxycinnamates

BACKGROUND

The structural reinforcement of cell walls by hydroxycinnamates has a significant role in defense against pests and pathogens, but it also interferes with forage digestibility and biofuel production. Elucidation of maize genetic variations that contribute to variation for stem hydroxycinnamate content could simplify breeding for cell wall strengthening by using markers linked to the most favorable genetic variants in marker-assisted selection or genomic selection approaches​.

RESULTS

A genome-wide association study was conducted using a subset of 282 inbred lines from a maize diversity panel to identify single nucleotide polymorphisms (SNPs) associated with stem cell wall hydroxycinnamate content. A total of 5, 8, and 2 SNPs were identified as significantly associated to p-coumarate, ferulate, and total diferulate concentrations, respectively in the maize pith. Attending to particular diferulate isomers, 3, 6, 1 and 2 SNPs were related to 8-O-4 diferulate, 5-5 diferulate, 8-5 diferulate and 8-5 linear diferulate contents, respectively. This study has the advantage of being done with direct biochemical determinations instead of using estimates based on Near-infrared spectroscopy (NIRS) predictions. In addition, novel genomic regions involved in hydroxycinnamate content were found, such as those in bins 1.06 (for FA), 4.01 (for PCA and FA), 5.04 (for FA), 8.05 (for PCA), and 10.03 and 3.06 (for DFAT and some dimers).

CONCLUSIONS

The effect of individual SNPs significantly associated with stem hydroxycinnamate content was low, explaining a low percentage of total phenotypic variability (7 to 10%). Nevertheless, we spotlighted new genomic regions associated with the accumulation of cell-wall-bound hydroxycinnamic acids in the maize stem, and genes involved in cell wall modulation in response to biotic and abiotic stresses have been proposed as candidate genes for those quantitative trait loci (QTL). In addition, we cannot rule out that uncharacterized genes linked to significant SNPs could be implicated in dimer formation and arobinoxylan feruloylation because genes involved in those processes have been poorly characterized. Overall, genomic selection considering markers distributed throughout the whole genome seems to be a more appropriate breeding strategy than marker-assisted selection focused in markers linked to QTL.

P4598Clinical implications and predictors of coronary perforations during chronic total occlusion percutaneous coronary interventions: insights from the multicenterLatin America CTO LATAM registry

Background

Chronic total occlusions are still considered one of the most challenging procedures in the field of interventional cardiology and the most feared complication are the perforations. In past studies and series from Asia, Europe and United States the rate of perforations in percutaneous coronary interventions are described as 0.2% whereas this rate increases to 3% when recanalization of a chronic total occlusion is attempted.

Purpose

Our study sought to identify the frequency, predictors and clinical implications of coronary perforations in chronic total occlusion percutaneous interventions in a contemporary registry with data from Latin America.

Methods

We reported the data of a prospective multi center Latin American registry from January to December 2018 in 1066 patients who underwent chronic total occlusion percutaneous interventions in 30 centers in the following countries: Brazil, Argentina, Puerto Rico, Chile, Colombia, Ecuador and Mexico. Coronary perforation was defined as evidence of extravasation dye or blood from the coronary artery during or following the procedure. A stepwise logistic regression was performed to investigate the independent predictors of coronary perforations.

Results

The mean age was 64.2±10.7 years, 79.8% were male, 35.3% diabetics and 6.7% had heart failure. The most commonly involved CTO vessel was right coronary artery (41.4%), the mean J-CTO score was 2.0±1.3 and the mean CL score was 2.7±1.6. The overall procedural success rate was 81.9%. Coronary perforation occurred in 3.3% of cases: type 1 in 1.8%, Type 2 in 0.9% and Type 3 in 0.6%. In comparison with patients without coronary perforation was observed, those with such complication required more often blood transfusion (8.6% vs. 0.7%; p<0.001), experienced more cardiac tamponade (13.4% vs. 0.4%; p<0.001), but not all-cause in-hospital mortality (0 vs. 1.0%; p=1.0; respectively). At multivariate analysis, the independent predictor of coronary perforation was an activated clotting time (ACT) during PCI >470 seconds (OR 6.5; 95% CI 2.4 - 17.3; p<0.001), baseline heart failure (OR 4.2; 95% CI 1.2 - 14.6) and J-CTO score ≥2 (OR7.5; 95% CI 1.0–59.1).

Conclusions

Coronary perforation during percutaneous interventions in Latin America occurred in 3.3% of patients, being related with adverse events but not in-hospital all-cause mortality. Pharmacological management, high anatomical complexity and heart failure were identified as independent predictors of this still and so feared complication.

Acknowledgement/Funding

None

QTLs for Resistance to Fusarium Ear Rot in a Multiparent Advanced Generation Intercross (MAGIC) Maize Population

Alternative approaches to linkage and association mapping using inbred panels may allow further insights into loci involved in resistance to Fusarium ear rot and lead to the discovery of suitable markers for breeding programs. Here, the suitability of a maize multiparent advanced-generation intercross population for detecting quantitative trait loci (QTLs) associated with Fusarium ear rot resistance was evaluated and found to be valuable in uncovering genomic regions containing resistance-associated loci in temperate materials. In total, 13 putative minor QTLs were located over all of the chromosomes, except chromosome 5, and frequencies of favorable alleles for resistance to Fusarium ear rot were, in general, high. These findings corroborated the quantitative characteristic of resistance to Fusarium ear rot in which many loci have small additive effects. Present and previous results indicate that crucial regions such as 210 to 220 Mb in chromosome 3 and 166 to 173 Mb in chromosome 7 (B73-RefGen-v2) contain QTLs for Fusarium ear rot resistance and fumonisin content.

Genome-wide association analysis for fumonisin content in maize kernels

BACKGROUND

Plant breeding has been proposed as one of the most effective and environmentally safe methods to control fungal infection and to reduce fumonisin accumulation. However, conventional breeding can be hampered by the complex genetic architecture of resistance to fumonisin accumulation and marker-assisted selection is proposed as an efficient alternative. In the current study, GWAS has been performed for the first time for detecting high-resolution QTL for resistance to fumonisin accumulation in maize kernels complementing published GWAS results for Fusarium ear rot.

RESULTS

Thirty-nine SNPs significantly associated with resistance to fumonisin accumulation in maize kernels were found and clustered into 17 QTL. Novel QTLs for fumonisin content would be at bins 3.02, 5.02, 7.05 and 8.07. Genes with annotated functions probably implicated in resistance to pathogens based on previous studies have been highlighted.

CONCLUSIONS

Breeding approaches to fix favorable functional variants for genes implicated in maize immune response signaling may be especially useful to reduce kernel contamination with fumonisins without significantly interfering in mycelia development and growth and, consequently, in the beneficial endophytic behavior of Fusarium verticillioides.

The GBA p.Trp378Gly mutation is a probable French-Canadian founder mutation causing Gaucher disease and synucleinopathies

Biallelic GBA mutations cause Gaucher disease (GD), and heterozygous carriers are at risk for synucleinopathies. No founder GBA mutations in French-Canadians are known. GBA was fully sequenced using targeted next generation and Sanger sequencing in French-Canadian Parkinson disease (PD) patients (n = 436), rapid eye movement (REM)-sleep behavior disorder (RBD) patients (n = 189) and controls (n = 891). Haplotype, identity-by-descent (IBD) and principal component analyses (PCA) were performed using single nucleotide polymorphism-chip data. Data on GD patients from Toronto and Montreal were collected from patients' files. A GBA p.Trp378Gly mutation was identified in two RBD and four PD patients (1% of all patients combined), and not in controls. The two RBD patients had converted to DLB within 3 years of their diagnosis. Haplotype, IBD and PCA analysis demonstrated that this mutation is from a single founder. Out of 167 GD patients screened, 15 (9.0%) carried the p.Trp378Gly mutation, all in trans with p.Asn370Ser. Three (20%) of the GD patients with the p.Trp378Gly mutation had developed Parkinsonism, and 11 patients had family history of PD. The p.Trp378Gly mutation is the first French-Canadian founder GBA mutation to be described, which leads to synucleinopathies and to GD type 1 when in compound heterozygosity with p.Asn370Ser.

First Report of Phaeoacremonium inflatipes, P. iranianum, and P. sicilianum Causing Petri Disease of Grapevine in Spain

In 2008, four isolates of Phaeoacremonium, morphologically and genetically different from known Phaeoacremonium spp. in Spain, were isolated from rootstocks of young grapevine (Vitis vinifera) plants showing Petri disease symptoms including low vigor, reduced foliage, and dark streaking of the xylem in Badajoz Province (western Spain; cv. Syrah on SO4 rootstock), Tarragona Province (eastern Spain; cv. Garnacha on 161 49 C rootstock), and Balearic Islands (eastern Spain; cv. Tempranillo on Rupestris de Lot rootstock). Single-conidial isolates were obtained and grown on potato dextrose agar (PDA) and malt extract agar (MEA) at 25°C for 2 to 3 weeks in the dark until colonies sporulated (3). Identification was based on morphological characteristics (1-3). Phaeoacremonium inflatipes W. Gams, Crous & M. J. Wingf. and P. iranianum L. Mostert, Gräf., W. Gams & Crous were detected in Badajoz Province and P. sicilianum Essakhi, Mugnai, Surico & Crous in Tarragona Province and Balearic Islands. Colonies of P. inflatipes were gray on PDA and gray-brown on MEA. Conidiophores were branched, 15 to 37 (mean 25) μm long. Conidia were hyaline, oblong-ellipsoidal or obovoid, 3 to 5.5 (mean 4) μm long, and 1.2 to 1.9 (mean 1.6) μm wide. Colonies of P. iranianum were brownish gray on PDA and pale brown on MEA. Conidiophores were unbranched and 18 to 47.5 (mean 29) μm long. Conidia were hyaline, oblong-ellipsoidal, 3 to 5 (mean 4) μm long, and 1 to 1.8 (mean 1.5) μm wide. Colonies of P. sicilianum were pale brown on PDA and brown to pale orange on MEA. Conidiophores were branched and 13 to 55 (mean 32.5) μm long. Conidia were hyaline, allantoid, 3 to 8.5 (mean 6) μm long, and 1.5 to 2 (mean 1.8) μm wide. Identity of isolates Pin-2, Pir-4, Psi-1, and Psi-2 was confirmed by sequencing a fragment of the beta-tubulin gene with primers T1 and Bt2b (P. inflatipes, isolate Pin-2: GenBank Accession No. FJ872407, 100% similarity to Accession No. AY579323; P. iranianum, isolate Pir-4: GenBank Accession No. FJ872406, 99% similarity to Accession No. EU128077; P. sicilianum isolates Psi-1 and Psi-2: GenBank Accession Nos. FJ872408 and No. FJ872409, 100% similarity to Accession No. EU863489). Pathogenicity tests were conducted using Pin-2, Pir-4, and Psi-1 isolates. One-year-old callused and rooted cuttings of 110 R rootstock cultivated in sterile peat were wounded at the uppermost internode with an 8-mm cork borer. An 8-mm mycelium plug from a 2-week-old culture was placed into the wound. Wounds were wrapped with Parafilm. Ten cuttings per fungal isolate were used. Ten control plants were inoculated with 8-mm noncolonized PDA plugs. Plants were maintained in a greenhouse at 25°C. Within 2 months, all Phaeoacremonium-inoculated cuttings exhibited shoots with poor growth, small leaves, short internodes, and black streaks in the xylem. The mean shoot weight per plant was 1.8 g in P. inflatipes-inoculated plants, 1.9 g in P. iranianum-inoculated plants, and 1.6 g in P. sicilianum-inoculated plants, all lower than the control treatment (6.8 g). Control plants did not show any symptoms. All fungal species were reisolated from wood of all inoculated cuttings, completing Koch's postulates. Their identity was confirmed with the methods described above. To our knowledge, this is the first report of P. inflatipes, P. iranianum, and P. sicilianum causing Petri disease in Spain. References: (1) P. W. Crous et al. Mycologia 88:786, 1996. (2) S. Essakhi et al. Persoonia 21:119, 2008. (3) L. Mostert et al. Stud. Mycol. 54:1, 2006.

Is African descent an independent risk factor of peripartum cardiomyopathy?

Risk factors for peripartum cardiomyopathy (PPCM) are controversial. PPCM seems to be more prevalent in women of African descent, the highest observed incidence is in Haiti (1 per 300 live births). Our retrospective study conducted in Martinique showed an incidence of 1 per 5500 live births. This incidence is significantly lower than in Haiti. Women from Martinique and Haiti do not differ for most classical risk factors: African descent, age, pregnancy-associated hypertension, multiple pregnancy and pre-eclampsia. However, the parity rate and the socioeconomic level are different. Thus, African descent could be confounded by high parity rate and socioeconomic status.

Free phenols in maize pith and their relationship with resistance to Sesamia nonagrioides (Lepidoptera: Noctuidae) attack

The stem borer Sesamia nonagrioides (Lefèbvre) is the most important insect pest of maize, Zea mays L., in northwestern Spain. Among the metabolites present in maize, phenolic compounds could play an important role in resistance. The objective of this work was to determine whether a relationship between phenols and the amount of resistance exists. Amounts of free phenolic compounds in the pith of 13 inbred maize lines that differ in resistance were measured. The phenolic compounds identified were p-coumaric acid, cafeic acid, ferulic acid, vanillic acid, syringic acid, chorogenic acid, sinapic acid, p-hydroxybenzoic acid, and vanillin. The amount of free p-coumaric acid was correlated with the resistance level. Higher quantities of p-coumaric in the pith could contribute to general resistance to stem borer attack. Jointly with ferulic acid, p-coumaric could provide resistance mechanisms through cell wall fortification and lignification. The other compounds showed no or an unclear relationship with resistance. The vanillic acid showed a decreased tendency after silking, when maize is most attractive for S. nonagrioides, suggesting this acid could act as a chemoattractant for S. nonagrioides larvae or adults. Future studies that focus on these phenolic compounds could be useful in understanding S. nonagrioides resistance.

First Report of Tobacco as a Natural Host of Tomato yellow leaf curl virus in Spain

Two begomovirus species, Tomato yellow leaf curl Sardinia virus (TYLCSV) and Tomato yellow leaf curl virus (TYLCV), have been identified as causal agents of tomato yellow leaf curl disease (TYLCD) in Spain. TYLCSV was reported in Spain in 1992 and TYLCV in 1997 on tomato crops (3). TYLCV was also reported in common bean (Phaseolus vulgaris L.) and pepper (Capsicum annuum L.) crops in southern Spain in 1997 and 1999, respectively. During the summer of 2004, symptoms of yellowing, crumpling, and necrosis of new leaves were observed sporadically in young, field-grown tobacco (Nicotiana tabacum L.) plants in the Badajoz Province. These tobacco plants were next to tomato crops where TYLCV was detected for the first time in Badajoz in 2003. In September 2004, four symptomatic tobacco plants were selected for double antibody sandwich enzyme linked immunosorbent assay (DAS-ELISA) and polymerase chain reaction (PCR) identification analyses. Serological analyses were carried out in two repetitions and with the following polyclonal antisera: Potato virus Y (PVY) (Loewe Biochemica, Sauerlach, Germany); Tobacco mild green mosaic virus (produced in our laboratory); Tobacco mosaic virus (BIO-RAD, Marnes-La-Coquette, France); and Tomato spotted wilt virus (Loewe Biochemica). A simplified method of duplex PCR was used for a rapid, sensitive, and simultaneous detection of TYLCSV and TYLCV (2). Mixed infections of PVY and TYLCV were detected in all four tobacco samples tested. TYLCV infection was confirmed using the primer pair TY-1/TY-2 specific for the coat protein (CP) gene of begomoviruses (1). The CP fragment was digested with the restriction enzyme AvaII, and the pattern obtained corresponded to that obtained from TYLCV-infected tomato that served as a positive control. Two PCR products from different tobacco samples were sequenced and both showed 100% identity with the corresponding region (Almería) of TYLCV (GenBank Accession No. AJ489258) and 99% with TYLCV-Mild (Spain) (GenBank Accession No. AJ519441), confirming the diagnosis. The symptoms observed in the tobacco plants can not be attributed solely to TYLCV since the virus was present in a mixed infection with PVY. However, tobacco infected with TYLCV may serve as an important alternate host for TYLCV in the tomato cropping system. To our knowledge, this is the first report of N. tabacum as a natural host of TYLCV in Spain. References: (1) G. P. Accotto et al. Eur. J. Plant Pathol. 106:179, 2000. (2) P. Martínez-Culebras et al. Ann. Appl. Biol. 139:251, 2001. (3) J. Navas-Castillo et al. Plant Dis. 81:1461, 1997.

Relationship between maize stem structural characteristics and resistance to pink stem borer (Lepidoptera: Noctuidae) attack

The pink stem borer, Sesamia nonagrioides (Lefebvre), is one of the most important insect pests of maize (Zea mays L.) in northwestern Spain. The objectives of this work were to evaluate, at different times during the growth of maize, structural traits related to the entry point and tissues on which larvae feed and to determine the relationship between these structural traits and the stem borer resistance. Six inbred lines with different levels of stem resistance to S. nonagrioides were evaluated in several trials. Potential structural resistance factors included rind and pith puncture resistance (RPR and PPR), rind thickness, length of the meristematic area (LMA), and pith parenchyma interlumen thickness (PPIT). Surprisingly, the inbred lines that showed the strongest stalks, EP42 and EP47, were not stem resistant to pink stem borer attack, while the stem resistant inbreds A509, CM151, and PB130 were among the least resistant to rind puncture. There were no significant differences among resistant and susceptible inbreds for the rind thickness. However, the susceptible inbred EP42 had the softest internode pith, and the resistant inbred PB130 showed the hardest, as was expected. Susceptible inbred lines in general showed higher values for the LMA, while the PPIT was important for individual inbreds. The results suggest that the usefulness of these characters as estimators of pink stem borer resistance is limited to some genotypes. Besides, even among those genotypes, other mechanisms of resistance that do not involve stalk strength could be present. Among the traits considered, the LMA was the most promising as an indicator of resistance to pink stem borer, although further experimentation is necessary.

Biodegradation of simazine in olive fields

Simazine (2-chloro-4, bis ethylamino-1,3,5-triazine) is a herbicide of the s-triazine group used mainly to control broad-leaved weeds in different crops. Several papers report about simazine and other s-triazine derivates as being actual polluting agents. In fact, simazine has been detected in groundwater and soil. Since this herbicide has been extensively used in Andalusia (south of Spain), we are analyzing the levels of simazine residues found in the soil of olive fields. We are also simazine could be detected isolating live micro organisms able to degrade this compound, and are characterizing the metabolic pathways leading to this degradation and the fate of this compound in nature. With all these data in mind, we will try to develop a strategy for the bioremediation of contaminated soils. We have taken samples of soil from many olive orchards of Andalusia that have been treated with simazine. These samples were located with the help of a handheld GPS. The presence of simazine of these samples was detected by HPLC. In most of the samples taken no, and those where it could be, contained very low levels of this herbicide (lower than 0.5 ppm). Soil samples are being characterized to determine their physicochemical characteristics [pH, organic matter, texture, etc), and we are attempting to correlate all these parameters with the presence or absence of simazine. From some of the soils, we have isolated a group of micro organisms that can grow using simazine as the sole carbon and nitrogen sources. We are analyzing how the addition of carbon or nitrogen can influence the rate of the simazine degradation.

First Report of Bacterial Deep Bark Canker of Walnut Caused by Brenneria (Erwinia) rubrifaciens in Europe

During the summer of 1995 and subsequent years, bark cankers were observed in walnut trees (cv. Hartley grafted on Juglans hindsii) imported from California in 1978 growing in Badajoz, Spain. Two foci were found in an orchard of 200 ha where 80 walnut trees were affected. Cankers were observed on trunks and branches, and dark exudates staining the bark appeared mainly in summer. Isolations were performed from affected tissue using King's B medium, and Brenneria (Erwinia)-like colonies (1) were purified and characterized. Gram reaction, Kovacs' oxidase, O/F metabolism, aesculin hydrolysis, urease activity, and levan production were assayed for five isolates (1). Biochemical characterization was performed by the miniaturized API 20E, API 20NE, and API 50CH systems (BioMérieux, Marcy-l'Etoile, France) as recommended, except for incubations that were made at 25°C for 48 h. Analyses of the cellular fatty acids of selected isolates were performed as described by Sasser (2). They were also tested in indirect enzyme-linked immunosorbent assay (ELISA) using antisera obtained against the reference strain CFBP 1284 and one Spanish isolate. When compared to the reference strain from California, isolates were identified as Brenneria rubrifaciens (1,3) on the basis of physiological and biochemical characteristics, fatty acid profiles, and ELISA. Pathogenicity of two selected Spanish isolates was confirmed using three 2-year-old walnut trees per bacterial isolate by inoculating 10⁸ CFU of each isolate in deep wounds made in the trunk at 40 and 80 cm from the crown. The reference strain and water were also inoculated as controls. Two months later, removal of the outer bark of walnut revealed typical dark lesions in the inner bark at all the inoculation sites on trees inoculated with the Spanish and reference strains, but no external cankers were observed. Four years later, these plants showed internal lesions (20 to 80 cm), from which B. rubrifaciens was reisolated far away from the inoculation site. To our knowledge this is the first report of this bacterium in Europe. References: (1) L. Hauben et al. Syst. Appl. Microbiol 21:384, 1998. (2) M. Sasser. Pages 199-204 in: Methods in Phytobacteriology. Budapest, Hungary, 1990. (3) E. Wilson et al. Phytopathology 57:618, 1966.

[Epilepsy and pregnancy]

INTRODUCTION

Treatment of the epileptic patient during pregnancy poses a major clinical dilemma. For one thing the patient has to be kept free of seizures, but she also should be kept on monotherapy at the lowest possible dose, due to the effect such medication may have on the unborn child.

DEVELOPMENT

There is a syndrome related to intra uterine exposure to the classical antiepileptic drugs, but which is not associated with any particular drug. However, the effect of the new antiepileptic drugs on unborn children is still unknown. To date, no specific pattern of malformations has been described in relation to any of these drugs. Lamotrigine is the one with which there is most clinical experience. Although there are still not enough cases studied to permit definite conclusions to be drawn, at the moment the incidence of congenital anomalies is the same as in the general population.

CONCLUSIONS

The new anti-epileptic drugs have a major therapeutic advantage, not only in the management of epilepsy in different clinical situations, but also in the good results observed when using lamotrigine in patients of fertile age.

[Cerebral infarct in childhood as a complication of migraine with aura. A case report]

INTRODUCTION

A migrainous infarct is a complication which may occur during the course of an attack of migraine, especially during the phase of the aura. It is the cause of between 1 and 14% of the cerebral infarcts in children. Even today there is still controversy as to whether it occurs in childhood, in spite of a strongly based clinical suspicion of it, since it is difficult to prove the chain of clinicopathological events scientifically.

CLINICAL CASE

We report the clinical case of an adolescent girl of eleven years of age who complained of having attacks of migraine with aura for the previous two years and fulfilled the criteria of the International Headache Society (IHS). She was referred to us when a cranial CAT scan showed a hypodense area at the level of the ganglia of the left base, although neurological examination was still normal. The probable ischaemic nature of the lesion was confirmed using neuroimaging techniques (magnetic resonance). On electroencephalography there was a slow focal pattern which was moderately persistent in the left temporal cortex. Other causes of cerebral infarct were rules out on further complementary studies.

CONCLUSIONS

The patient therefore fulfilled the criteria of the IHS for diagnosis of a migrainous infarct. We also analyze the main findings regarding clinical history, epidemiology, clinical findings and diagnosis of migrainous infarct in childhood.

[Monitoring of lettuce crops of Ribeirão Preto, SP, Brazil]

The ingesting of raw vegetables plays an important role in the transmission of several infectious diseases due to the high frequency of irrigation with wastewater. The objective of this study was to evaluate the sanitary conditions of all lettuce producing crops in Ribeirão Preto through microbiological and parasitological analysis of both irrigation water and lettuce together with the implantation of an effective crop monitoring. Laboratory analysis of 129 crops showed irregularities in 26 (20.1%) of these: high concentration of fecal coliforms in 17% of the lettuce, presence of Salmonella in 3.1% and several enteroparasites (Ascaris sp, Ancylostomidae, Strongyloides sp, Hymenolepis nana, and Giardia sp ) in 13.1%. Persistent irregularities determined the definitive closing down of one producer; all of the remaining 128 crops were eventually approved, thus demonstrating the efficacy of lettuce crop monitoring. Crops approved in the laboratory analysis were awarded a Sanitary Inspection Certificate - an unprecedented procedure in our Country - that resulted in a better acceptance of the monitoring.

Cellular mechanisms of intestine regeneration in the sea cucumber, Holothuria glaberrima Selenka (Holothuroidea:Echinodermata)

Echinoderms are the deuterostome group with the most striking capacity to regenerate lost body parts. In particular, members of the class Holothuroidea are able to regenerate most of their internal organs following a typical evisceration process. Such formation of new viscera in an adult organism provides a unique model to study the process of organogenesis. We have studied this process in the sea cucumber Holothuria glabberrima by describing the spatial and temporal pattern of cellular events that occur during intestine regeneration following chemically induced evisceration. Regeneration begins as a thickening of the mesenteries that supported the autotomized organs to the body wall. The mesenterial thickening consists of tissues where most of the cellular populations found in the normal intestine are already present. However, the cell numbers differ, particularly those of hemocytes and amoebocytes, suggesting that some of these cells play an important role in the formation of the solid rod of hypertrophic mesentery that characterizes the intestinal primordia. The appearance of the luminal epithelium, together with the formation of the lumen, occurs during the second week of regeneration by proliferation and extensive migration of cells from the esophagus and cloacal ends into the thickenings. At this stage all tissue layers are present, but it takes an additional week for them to exhibit the proportions typical of the normal organ. Cell division, as determined by BrdU labeling, mainly occurs in the coelomic epithelia of the hypertrophic mesentery and in the regenerating luminal epithelium. Our study provides evidence that the process of new organ formation in holothurians can be described as an intermediate process showing characteristics of both epimorphic and morphallactic phenomena.

Transrectal ultrasonography: relationship with anorectal manometry, electromyography and sensitivity tests in irritable bowel syndrome

Irritable bowel syndrome is the most frequently diagnosed disorder in gastroenterology. It has been demonstrated with specialized motility studies that these patients compared to healthy subjects show changes in rectoanal electrical and mechanical activity and in rectoanal sensitivity. However, until now no report has been published on morphological alterations in the rectum or the internal anal sphincter. Twenty-five consecutive patients with irritable bowel syndrome (mean age 32, range 17-47 years; 24 females) were evaluated prospectively by transrectal ultrasonography, rectal sensitivity studies, and recordings of both electrical and mechanical activity of the distal rectum and internal anal sphincter during a 2-h inter-digestive period. Ten healthy volunteers (mean age 34.5, range 19-50 years) served as a control group. Paired and non-paired Student's two-tailed t test and linear regression analysis were used. It was shown that muscle thickness of the rectum during rest (4.7 +/- 0.1 mm) was correlated neither with its rectal spike amplitude (0.73 +/- 0.1 mV) nor with rectal spike frequency (17.06 +/- 3.6 spike/2 h). In addition, the diameter of the internal anal sphincter (1.2 +/- 0.1 mm) was correlated neither with its resting pressure, nor with frequency (17.1 +/- 3.2/2 h), duration (14.9 +/- 1.5 s), or amplitude (14.1 +/- 1.9 mmHg), of inhibition of the spontaneous rectoanal inhibitory reflex. No correlation was found between ultrasonographic parameters and rectal distension variables (r = 0.03). This study demonstrates for the first time morphological anorectal changes in patients with irritable bowel syndrome compared to healthy subjects, in addition to showing that morphological changes are independent of physiological ones. Therefore both transrectal ultrasonography to determine anorectal morphology and electromanometry to assess anorectal function are important measures in the evaluation of patients with irritable bowel syndrome.

The murine homolog of the interleukin-8 receptor CXCR-2 is essential for the occurrence of neutrophilic inflammation in the air pouch model of acute urate crystal-induced gouty synovitis

OBJECTIVE

Acute neutrophil-dependent inflammation is central to acute gout. Urate crystals induce different classes of neutrophil chemotaxins, including certain chemokines (e.g., interleukin-8 [IL-8], growth-related oncogene alpha [GROalpha]) that share CXCR-2 as a receptor. This study was undertaken to assess the role of CXCR-2 ligands in a model of acute gout.

METHODS

Urate crystals were injected into subcutaneous air pouches in mice that expressed or lacked the murine CXCR-2 homolog (mIL-8RH), and the development of neutrophilic inflammation was assessed.

RESULTS

In normal mice, urate crystals induced a 10-fold increase (P < 0.01) in pouch fluid leukocytes (principally neutrophils) at 4 hours. Leukocytes adhered to the pouch lining, where crystals, the mIL-8RH ligand KC/GROalpha, and cells bearing mIL-8RH were abundant. In mIL-8RH(-/-) mice, urate crystals induced a proteinaceous leukocyte-poor exudate at 4 hours, despite crystal-induced activation of resident cells (documented by KC/GROalpha expression).

CONCLUSION

Chemokines that bind the IL-8 receptor CXCR-2 are essential for the development of acute neutrophilic inflammation in response to urate crystals in the subcutaneous air pouch model.

Mitral valve replacement with glutaraldehyde preserved aortic allografts

OBJECTIVE

To present long-term results after mitral valve replacement with stent mounted glutaraldehyde preserved aortic allografts in patients older than 15 years. The clinical support for this study was to combine the glutaraldehyde technique of biological tissue preservation with the advantages of allografts when compared to xenografts. This was demonstrated in previous studies using other methods of tissue processing.

METHODS

Between September 1984 and November 1994, 70 patients aged 16-77 years (mean 35.4 years) underwent mitral valve replacement with this preserved and mounted allograft. Of these, 40 patients (57.2%) were aged 16-35 years and 15 (21.4%) were 20 years old or younger; 46 (65.7%) were females and 24 (34.3%) males. Single mitral valve replacement was performed in 60 patients and 10 were also subjected to other combined cardiac procedures. Human aortic valves were obtained during routine autopsy, processed in glutaraldehyde and mounted into flexible stents, using the same technique as that used for porcine bioprostheses.

RESULTS

Hospital mortality was 1.4%. Total follow-up was 543.1 patient-years, corresponding to a mean follow-up of 7.9 years per patient. Echocardiography demonstrated a hemodynamic performance similar to porcine bioprostheses. Late mortality was 0.7 +/- 0.6% per patient-year and the causes were congestive heart failure in 2, prosthetic endocarditis in 1 and acute myocardial infarction in 1. The 12-year actuarial survival was 92.4 +/- 3.2%. The incidence of late complications was 5.2 +/- 1.2% per patient-year, including congestive heart failure, prosthetic endocarditis, periprosthetic leak, thromboembolic episodes, recurrence of rheumatic disease, coronary artery disease and allograft failure. Complications related to heart disease represented 2.8 +/- 0.6% and allobioprosthesis-related 2.4 +/- 0.5% per patient-year. The 12-year actuarial freedom from primary valve failure was 81.0 +/- 15.0%. The incidence of reoperations was 1.5 +/- 0.8% per patient-year and the main indication was prosthetic endocarditis. Other causes were periprosthetic leak, aortic insufficiency in the native aortic valve and allobioprosthesis dysfunction. Functional results demonstrated a significant improvement in patients clinical condition.

CONCLUSION

This 12-year follow-up shows a very low incidence of primary allograft failure for patients older than 15 years undergoing mitral valve replacement, and much superior than our results with porcine bioprosthesis in the same age group. This supports our assumption that this investigational valve represents a new advance in cardiac valve surgery.

A leukocyte homologue of the IL-8 receptor CXCR-2 mediates the accumulation of macrophages in atherosclerotic lesions of LDL receptor-deficient mice

Chronic macrophage-mediated inflammation is central to atherosclerosis. A role of the monocyte chemotactic and activating C-C chemokine JE/monocyte chemotactic protein-1 has been proposed. However, the human C-X-C chemokines growth-regulated oncogene (GROalpha) and IL-8, and their shared receptor, CXCR-2, also can be expressed at sites of chronic inflammation. Because we detected CXCR-2 in the intima of human atherosclerotic lesions, we examined the role of leukocyte CXCR-2 expression in affecting lesion cellularity. Atherosclerosis-susceptible LDL receptor-deficient mice were irradiated, successfully repopulated with bone marrow cells that either lacked or expressed mIL-8RH (the homologue of CXCR-2), and fed an atherogenic diet for 16 wk. In recipients of mIL-8RH+/+ marrow, mIL-8RH colocalized with densely accumulated intimal MOMA-2 positive macrophages. In contrast, lesions in recipients of mIL-8RH-/- marrow lacked mIL-8RH, had little intimal MOMA-2 staining, and were less extensive. The mIL-8RH ligand KC/GROalpha was detected in the intima of all aortic atherosclerotic lesions. Thus, the capacity of leukocytes to express mIL-8RH, and associated intralesional expression of its ligands such as KC/GROalpha, mediated the intimal accumulation of macrophages in atherosclerotic lesions of LDL receptor-deficient mice.

Defaecography in patients with irritable bowel syndrome and healthy volunteers

BACKGROUND

In patients with IBS, many symptoms have their origin in the recto-anal segment, with motility changes in the rectum and in the internal anal sphincter, and alterations in rectal sensitivity. However, up to now, it is not known if these clinical and physiological changes are equated with morphological changes in the recto-anal segment.

METHODS

Sixteen consecutive patients with IBS (mean age 22, range 18-33 years; 13 females) and 10 healthy volunteers (mean age 34.5, range 19-50 yr.; 6 males) were evaluated prospectively with defaecography.

RESULTS

1) Anorectal angle: No significant differences were observed in the anorectal angle during rest (91.6 +/- 3.5 degrees vs 92.6 +/- 2.5 degrees) and during defaecation (92 +/- 5.5 degrees vs 98.7 +/- 2.6 degrees) between patients with IBS and healthy volunteers. However, patients with IBS were unable to widen the angle during defaecation, remaining the same at rest (91.6 +/- 3.5 degrees) as during defaecation (92 +/- 5.5 degrees). IBS patients with constipation (n = 2) compared to those with normal frequency defaecation (n = 13) showed no significant differences at rest (95 +/- 6 vs 89.8 +/- 4.1 degrees) and during defaecation (100 +/- vs 88.9 +/- 6.4 degrees). Healthy volunteers widened the angle by more than 5 degrees during defaecation. 2) Perineometry: although not significant, patients with IBS had less perineal descent during the simulated defaecation (1.98 +/- 0.37 cm) than healthy subjects (2.1 +/- 0.3 cm). Nevertheless, during squeeze there was significantly less mobility or perineal descent in patients with IBS than in control subjects (0.21 +/- 0.17 vs 0.95 +/- 0.21 cm; P = 0.01).

CONCLUSIONS

The findings of this study suggest that patients with IBS as a whole, whether constipation predominant or not, showed changes in pelvic-floor mobility.

Electron microscopy and biological properties of pBR322 DNA condensed with the trivalent cations spermidine and hexammine cobalt (III)

Electron microscopy and the biological properties of susceptibility to DNase I, genetic transcription, and transformation of pBR322 DNA compacted with spermidine or hexammine cobalt (III), were analyzed in order to characterize the association of DNA in its compacted form with these two different trivalent cations. Spermidine and hexammine cobalt (III) produced an average 4-fold reduction of the DNA perimeter in compact DNA forms, which were doughnut-shaped toroids and cylinders. Both compacted DNAs were resistant to the hydrolytic activity of DNase I. However, spermidine-condensed pBR322 DNA was 10-fold and 4 to 6-fold more active in transcription and transformation, respectively, than naked pBR322. I. Hexammine cobalt (III)-condensed pBR322 was inactive in both biological properties. An inhibitory effect of hexammine cobalt (III) on RNA polymerase and genetic transformation activities was discarded because at higher ionic strength, in which DNA is not compacted by hexammine cobalt (III), transcription and transformation were similar to those observed with naked DNA. This information showed that the interaction of hexammine cobalt (III) with the DNA converted the pBR322 DNA into an inert molecule. In contrast, pBR322 did not loose its biological properties after its interaction with the polyamine spermidine; i.e., experimental condensation of pBR322 DNA by spermidine produced compacted DNA that is more similar to compact native genomes than relaxed DNA. These experiments led us to conclude that spermidine-condensed DNA can be used to study the roll of the native supercoiling of DNA in the regulation of genetic replication and transcription, as well as to study the mechanisms that allow the accessibility of the supercoiled or condensed DNA substrate for enzymes.

Spermidine-condensed DNA and cone-shaped lipids improve delivery and expression of exogenous DNA transfer by liposomes

A new liposome system containing spermidine-condensed DNA and negative cone-forming lipids designed to improve gene delivery and expression is described. The compacted nature of condensed DNA forms permitted a higher extent of encapsulation of DNA in liposomes. These vesicles contained fusogenic cone-shaped lipids to increase fusion between liposomes and membranes to enhance the amount of DNA delivery into the cells. In addition, the insensitivity of condensed DNA forms to endonucleases and restriction enzymes, as well as their higher activity in both replication and transcription, improve foreign DNA expression. These improvements in condensed DNA encapsulation in liposomes, transfer into the cells, and DNA expression increase the number of transfected cells and produce a higher level of gene expression in most transfected cells. This is reflected in the 60-fold cell culture transfection increase compared with traditional liposome transfection systems. This liposome system does not cause any apparent damage to the transfected cells; furthermore, the liposomes are small, 400-500 nm, and have negative surface charges that can prolong their circulation half-lives in vivo, permitting their use for in vivo gene therapy applications.

Lithium toxicity and myxedema coma in an elderly woman

The development of hypothyroidism as a side effect of lithium therapy is a well recognized phenomenon. However, the presentation of myxedema coma after lithium intoxication has not been previously documented. In this case lithium toxicity may have exacerbated preexisting hypothyroidism to the point of respiratory arrest. Based on this case, we recommend periodic monitoring of thyroid function in an effort to detect preexisting hypothyroidism or lithium-induced hypothyroidism.

Concerted action of beta-glucuronidase and beta-acetylglucosaminidase on hyaluronodextrins

A kinetic analysis of the stepwise alternating action of beta-glucuronidase and beta-acetylglucosaminidase on oligosaccharides and dextrins derived from hyaluronic acid was undertaken, for better definition of the contribution of this process to hyaluronate catabolism. Production of monosaccharide from larger dextrins by action of either enzyme is powerfully inhibited by electrolyts. In the study, as in mammalian tissues, beta-glucuronidase is present in excess so that the concentration of beta-acetylglucosaminidase is rate controlling in the action on dextrin substrates. For this action, Vmax shows limited variation with ionic strength or molecular weight of substrate. At ionic strength 0.03, but not 0.18, Km decreases some 100-fold for increase of molecular weight from 2,000 to 15,000. It is specifically this decrease in Km that accounts for the prominent electrolyte inhibition observed with larger dextrins. The extremely low values of Km are attributed to multiple ionic enzyme-substrate interactions at sites remote from the catalytic center. The previously reported stimulation by electrolyte of the action of beta-glucuronidase and beta-acetylglucosaminidase on aryl glycosides, studied briefly, is apparently unrelated to the electrolyte effects seen with dextrins. The catabolic contribution of beta-glucuronidase and beta-acetylglucosaminidase appears to be restricted to hydrolysis of the smaller oligosaccharides produced by action of hyaluronidase, since, for any reasonable assumptions regarding cellular environment, the extent of their action on polymeric hyaluronate or larger dextrins must be limited.