[Effectiveness of empirical Helicobacter pylori eradication therapy with furazolidone in Russia: results from the European Registry on Helicobacter pylori Management (Hp-EuReg)]

BACKGROUND

First-line therapy does not always provide a high level of Helicobacter pylori eradication due to the increase of H. pylori resistance to antibiotics; therefore, it remains necessary to identify the most effective rescue treatments. The purpose of this study was to evaluate the efficacy and safety of empirical H. pylori furazolidone-containing regimens.

MATERIALS AND METHODS

Adult H. pylori infected patients empirically treated with furazolidone-containing eradication regimens were registered in an international, prospective, multicenter non-intervention European registry on H. pylori management (Hp-EuReg). Data were collected at AEG-REDCap e-CRF from 2013 to 2021 and the quality was reviewed. Modified intention-to-treat (mITT) effectiveness analyses were performed.

RESULTS

Overall 106 patients received empirical furazolidone-containing therapy in Russia. Furazolidone was prescribed in a sequential scheme along with amoxicillin, clarithromycin and a proton pump inhibitor in 68 (64%) cases, triple regimens were prescribed in 28 (26%) patients and quadruple regimens in 10 (9.4%). Treatment duration of 7 days was assigned to 2 (1.9%) patients, 10-day eradication therapy in case of 80 (75%) and 14 days - in 24 (23%) patients. Furazolidone was mainly used in first- (79%) and second-line (21%) regimens. The methods used to diagnose H. pylori infection were: histology (81%), stool antigen test (64%), ¹³C-urea breath test (6.6%), and rapid urease test (1.9%). The mITT effectiveness of sequential therapy was 100%; 93% with the triple therapy and 75.5% with quadruple therapy. Compliance was reported in 98% of cases. Adverse events were revealed in 5.7% of patients, mostly nausea (3.8%). No serious adverse events were reported.

CONCLUSION

Furazolidone containing eradication regimens appear to be an effective and safe empirical therapy in Russia.

Radiotherapy skin marking with lancets versus electric marking pen - Comfort, satisfaction, effectiveness and cosmesis results from the randomized, double-blind COMFORTATTOO trial

INTRODUCTION

Set-up skin markings are performed, in several centers, for radiotherapy (RT) treatments. This study aimed to compare two permanent methods: lancets and an electric marking pen, the Comfort Marker 2.0® (CM).

METHODS

This was a prospective, unicentric, randomized study. Patients aged 18 years or older referred to our department to receive RT were recruited. Patients were randomly assigned, in a 1:1 ratio, to receive set-up markings using lancets or CM. The markings arrangement followed our departmental protocols. The coprimary endpoints were patients' comfort and effectiveness. Secondary endpoints included radiation therapists (RTTs) satisfaction and cosmesis.

RESULTS

Between October 2021 and January 2022, 100 patients were enrolled (50 received lancets and 50 CM) and assessed for the comfort and satisfaction outcomes. CM was significantly less painful than the lancets, with 44% and 16% of the patients, respectively, considering the tattooing process painless (RR = 2.75; 95% IC: 1.36 - 5.58). On the RTT-reported satisfaction, CM had significantly easier processes than lancets (98.0% vs. 78.0%, respectively; RR = 1.26; 95% CI: 1.08 - 1.46). For effectiveness and cosmesis assessment, 98 patients were analyzed (48 received lancets and 50 CM). Patients receiving CM had a significantly higher proportion of markings graded as good and excellent compared to those receiving lancets (98.0% and 50.0%, respectively, had ≥75% of the tattoos assessed as good/excellent, RR = 1.96; 95% CI: 1.47 - 2.61). On the cosmetic evaluation, patients receiving CM had significantly better cosmetic markings, with a median score of 4.4 (vs. 3.5 for lancets, p <0.001).

CONCLUSION

The trial results demonstrated that tattooing with the CM is significantly less painful, more effective, easier to apply, and cosmetically superior to tattooing with lancets.

IMPLICATIONS FOR PRACTICE

Tattooing with CM allows for better results regarding pain, quality, ease and cosmesis.

A comparison of harmonic and traditional sharp staphylectomy techniques in 15 brachycephalic dogs

OBJECTIVES

The objective was to compare sharp staphylectomy and staphylectomy using harmonic focus shears, assess surgical time, intraoperative haemorrhage and outcome. Our hypothesis was that harmonic staphylectomy would result in reduced surgical time, decreased intraoperative haemorrhage and greater relative improvement.

MATERIALS AND METHODS

Dogs that were presented to Highcroft Veterinary Referrals between July 2020 and September 2021 with brachycephalic obstructive airway syndrome and underwent surgical correction were prospectively enrolled. Surgical technique was randomised, and surgical time, staphylectomy time, intraoperative haemorrhage, hospitalisation and change in patients' Cambridge BOAS Grade at a 14-day recheck were recorded.

RESULTS

Fifteen dogs were enrolled: seven dogs underwent sharp and eight underwent harmonic staphylectomy. Nine patients returned for follow-up, four of seven and five of eight, respectively. Harmonic staphylectomy was associated with less haemorrhage (0 versus 9 cotton buds) and a shorter average staphylectomy time (3 minutes 36 seconds versus 14 minutes 50 seconds). No statistically significant differences were observed in total surgery time, number of nights hospitalised, or change in Cambridge BOAS Grade. An average of 0.68 mm of thermal necrosis was seen at the cut edges of soft palates removed by harmonic staphylectomy.

CLINICAL SIGNIFICANCE

Harmonic staphylectomy can result in a reduction in staphylectomy time and degree of intraoperative haemorrhage compared to sharp staphylectomy, with no deleterious impact on postoperative recovery or the long-term outcome of patients.

Computer-aided classification of colorectal segments during colonoscopy: a deep learning approach based on images of a magnetic endoscopic positioning device

OBJECTIVE

Assessment of the anatomical colorectal segment of polyps during colonoscopy is important for treatment and follow-up strategies, but is largely operator dependent. This feasibility study aimed to assess whether, using images of a magnetic endoscope imaging (MEI) positioning device, a deep learning approach can be useful to objectively divide the colorectum into anatomical segments.

METHODS

Models based on the VGG-16 based convolutional neural network architecture were developed to classify the colorectum into anatomical segments. These models were pre-trained on ImageNet data and further trained using prospectively collected data of the POLAR study in which endoscopists were using MEI (3930 still images and 90,151 video frames). Five-fold cross validation with multiple runs was used to evaluate the overall diagnostic accuracies of the models for colorectal segment classification (divided into a 5-class and 2-class colorectal segment division). The colorectal segment assignment by endoscopists was used as the reference standard.

RESULTS

For the 5-class colorectal segment division, the best performing model correctly classified the colorectal segment in 753 of the 1196 polyps, corresponding to an overall accuracy of 63%, sensitivity of 63%, specificity of 89% and kappa of 0.47. For the 2-class colorectal segment division, 1112 of the 1196 polyps were correctly classified, corresponding to an accuracy of 93%, sensitivity of 93%, specificity of 90% and kappa of 0.82.

CONCLUSION

The diagnostic performance of a deep learning approach for colorectal segment classification based on images of a MEI device is yet suboptimal (clinicaltrials.gov: NCT03822390).

87Sr/86Sr isotopic ratios in vineyard soils and varietal wines from Douro Valley

The assessment of wine authenticity is of utmost importance in the current context of a growing market globalization. The strontium isotopic ratio 87Sr/86Sr is a well-established tool for dating and tracing the origin of rocks and minerals with special interest for wine traceability. A study was developed to examine the variation of 87Sr/86Sr in wines from Douro Valley taking into account the effects of vineyard location and grape variety. The 87Sr/86Sr of soils and wines from six vineyards were determined by using an ICP-MS based analytical procedure. A total of twenty-two monovarietal wines, obtained at micro vinification scale, from relevant white and red grapevine varieties for Douro region, were analysed. The range of 87Sr/86Sr values observed in soils and wines was of 0.708–0.725 and 0.711–0.717, respectively. The present study updates the scarce knowledge available on strontium isotopic ratios in soils and wines from Douro Valley, and its results will enlarge global databank on wine composition and support comparison with other world regions.

Correction to: The Cancer, Educate to Prevent Model-the Potential of School Environment for Primary Prevention of Cancer

The affiliation address of Dr. Helena Santos should be Faculty of Economics, University of Porto, Portugal and Dr. Luís Moreira's should be Research Unit in Education and Community Intervention - RECI & Health School of Vila Nova de Gaia - Piaget Institute.

Infección de la orquídea terrestre Phaius tankervilliae (Orchidaceae) con el potexvirus del mosaico del Cymbidium (CymMV) en Costa Rica

En 1996, en un pequeño vivero comercial en la zona oeste del Valle Central de Costa Rica se observaron plantas de la orquídea terrestre Phaius tankervilliae que mostraban síntomas foliares de leves a severos de un estriado clorótico sistémico. En algunas flores los sépalos presentaron además manchas cloróticas y anillos blancos. Posteriormente en invernadero se observó que ocurría una senescencia más rápida en flores de plantas sintomáticas que en las flores de plantas sanas de la misma especie. Mediante tinción negativa de muestras purificadas se observaron electrónico de transmisión, partículas virales filamentosas poco flexuosas, con un tamaño aproximado a 500 nm de largo y 17 nm de ancho. Al analizar las partículas virales purificadas en geles desnaturalizantes de proteínas (SDS-PAGE), se determinó la presencia de una sola proteína de cápside cercana a los 28 kDa. En geles nativos de agarosa se determinó que el virus filamentoso observado contiene un ARN con una talla aproximada a los 7kb. Tanto el tamaño de la proteína de cápside como el ARN de este virus purificado concuerdan con los valores informados para el grupo de los potexvirus. Mediante la prueba de ELISA se comprobó que el potexvirus purificado corresponde  al virus del mosaico del Cymbidium (CymMV)

The Cancer, Educate to Prevent Model-the Potential of School Environment for Primary Prevention of Cancer

Cancer represents one of the main causes of death worldwide; consequently, preventive interventions are of utmost importance in public health education. The leading model of cancer prevention campaigns is based on general and undifferentiated actions mediated by health professionals, focusing on the technical and scientific information but rather ineffective in changing the symbolic, cognitive and practical relationship with the disease. New intervention models are thus required to address cancer literacy, being early interventions targeted to specific groups an elective counterpoint to contribute to positive and durable changes in cancer prevention. Our aim is to evaluate the feasibility and impact of cancer prevention programmes planned as focused interventions in restricted targets and mediated by non-healthcare professionals to increase cancer literacy and promote preventive behaviours. This pilot study evaluates schools' potential as a vehicle for cancer prevention education in a reality shaped by traditional health prevention campaigns. We developed a protocol of systematic surveying in order to review and, in the future, optimize and replicate this ecological model of intervention to other groups and contexts. The implementation of this model has been successful in which concerns to the effectiveness of the training programme for teachers. This led to the development of impactful cancer prevention education projects by trainees targeted to their students, allowing us to argue that it contributes to knowledge and practice in this complex as consensual priority area of intervention.

Brachial plexus injuries: diagnosis performance and reliability of everyday tools

PURPOSE

Determining the patterns of brachial plexus injuries is challenging. Diagnostic methods have been used to facilitate diagnosis, but there is no consensus regarding which tool best complements physical examination (PE). Magnetic resonance imaging (MRI) and nerve conduction studies (NCSs) are instruments with widespread use and feasibility for everyday assessment. In this study, we evaluated the diagnostic performance of these diagnostic instruments and PE. We also assessed the agreement in the PE and diagnostic instrument findings of two experienced and certified hand surgeons.

METHODS

We reviewed data gathered from medical records and compared these data with the results of operative findings. We divided data according to the site of injury and the root injury patterns for all three diagnostic instruments (PE, MRI, and NCSs).

RESULTS

We considered 102 assessments. We found poor inter-observer agreement for the PE assessments and poor agreement among the PE, NCS, and MRI assessments. Diagnostic performance was higher for PE: sensitivity = 97.8 [95% confidence interval (C.I.) = 92.1-99.7]; specificity = 30.8 [95% C.I. = 9.1-61.4], and NCSs (sensitivity = 98.9 [95% C.I. = 93.9-100]; specificity = 23.1 [95% C.I. = 5-53.8]. MRI had inferior performance for all measurements. Separate analysis using pre- and post-ganglionic injuries revealed that PE had the lowest sensitivity, 46.7 (95% C.I. = 21.3-73.4) despite having the highest specificity, 81.6 (95% C.I. = 71.9-89.1).

DISCUSSION

Low agreement among the findings using different diagnostic instruments demonstrated that PE is the most specific tool, despite its low sensitivity. Detailed PE is cornerstone for evaluating brachial plexus injuries and NCSs are better than MRI for scrutinizing injuries not found in PE.

CLINICAL RELEVANCE

In our study, NCSs exhibited superior performance to MRI, and should be considered a more reliable supporting tool after detailed PE.

'Candidatus Phytoplasma costaricanum' a novel phytoplasma associated with an emerging disease in soybean (Glycine max)

A novel phytoplasma, designated strain SoyST1c1, associated with a newly emerging disease in soybean (Glycine max), known as soybean stunt (SoyST), was found in 2002 in a soybean plantation in Alajuela Province, Costa Rica. The same phytoplasma, or a very closely related strain, also infected sweet pepper (Capsicum annuum) with purple vein syndrome (SwPPV) and passion fruit vine (Passiflora edulis) with bud proliferation disease (PasFBP) in the same region. Sequence analysis of cloned 16S rRNA gene sequences (GenBank accession nos FJ226068-FJ226073 and HQ225624-HQ225635) indicated that all three affected plants were infected by phytoplasmas that shared <97.5% sequence similarity with previously described phytoplasmas. The SoyST-causing phytoplasma represents a new taxon, most closely related to phytoplasma group 16SrI and 16SrXII strains. Virtual RFLP analysis indicated that the SoyST-causing phytoplasma and its closely related strains represent a novel 16Sr group, designated 16SrXXXI. Phylogenetic analysis of 16S rRNA gene sequences from the new phytoplasma strains, those previously described as 'Candidatus Phytoplasma spp.' and other distinct, as yet unnamed, phytoplasmas indicated that the SoyST-causing phytoplasma represents a distinct lineage within the aster yellows/stolbur branch on the phylogenetic tree. On the basis of its unique 16S rRNA gene sequence and biological properties, strain SoyST1c1 represents a novel taxon, for which the name 'Candidatus Phytoplasma costaricanum' is proposed with SoyST1c1 as the reference strain.

Staphylococcus aureus nasal and hand carriage among students from a Portuguese health school

This study aims to compare the frequency of Staphylococcus aureus nasal carriage among students from a Portuguese higher health school. Antimicrobial susceptibility testing was also assayed in order to detect methicillin-resistant S. aureus (MRSA) strains among the isolates. Nasal swabs and fingerprints from 60 healthy nursing and pharmacy students were collected, followed by inoculation and incubation at 37 degrees C for 24 h. All suspected S. aureus isolates were identified by routine laboratory procedures. The susceptibility to antimicrobial agents (tetracycline, gentamicin, chloramphenicol, amoxicillin/clavulanic acid, trimethoprim/sulphamethoxazole, oxacillin and vancomycin) of confirmed isolates was determined by a disc-diffusion method. Results showed 41.7% S. aureus colonisation among participants, and that the difference between nursing and pharmacy students was statistically significant. Antibiotic susceptibility testing demonstrated that S. aureus isolates showed variable sensitivity to antibiotics but, most importantly, were resistant to oxacillin and vancomycin. Although the frequency and prevalence of colonisation found is within the range previously described in healthy populations, increased resistance to antimicrobials and higher prevalence of MRSA among the student community was found.

First Report of New Phytoplasma Diseases Associated with Soybean, Sweet Pepper, and Passion Fruit in Costa Rica

A new soybean disease outbreak occurred in 2002 in a soybean (Glycine max) plantation in Alajuela Province, Costa Rica. Symptoms on the affected plants included general stunting, small leaves, formation of excessive buds, and aborted seed pods. In the same region, two other diseases, one in sweet pepper (Capsicum annuum) fields and another affecting passion fruit (Passiflora edulis) vines, were also found. Symptoms on sweet pepper plants included unusually dark green leaves, some of which exhibited a rugose symptom with a zigzag pattern to the midvein, and purple vein discoloration. Passion fruit vines exhibited bud proliferation. Collectively, symptoms resembled those commonly attributed to phytoplasmal infections. Total nucleic acid was extracted from veinal tissues of leaves or buds (soybean). A nested PCR assay using primer pair P1/P7 followed by R16F2n/R16R2 (1) was employed for the detection of putative phytoplasmas that might be associated within symptomatic plants. All seven symptomatic plants (three soybean, three sweet pepper, and one passion fruit) tested, but not healthy controls, yielded positive results. Restriction fragment length polymorphism (RFLP) analysis of nested PCR products using restriction enzymes AluI, BfaI, HhaI, MseI, and RsaI indicated that the three diseases were associated with a very similar or identical phytoplasma. RFLP patterns and sequence analysis of cloned 16S rDNAs (GenBank Accession Nos. FJ226068-FJ226073) revealed that the phytoplasma shared less than 97.5% sequence homology with all previously classified phytoplasmas, and, as such, represents a new taxon most closely related to 16SrXII group (1) strains. To our knowledge, this is the first report of a new phytoplasma associated with diseases of soybean, sweet pepper, and passion fruit in Costa Rica. Reference: (1) I.-M. Lee et al. Int. J. Syst. Bacteriol. 48:1153, 1998.

First Report of Xylella fastidiosa in Nerium oleander in Costa Rica

Oleander (Nerium oleander L.) shrubs presenting mottling, leaf tip and margin scorch, short internodes, defoliation, and branch dieback were observed at different localities in the Central Valley in Costa Rica. Severity of the symptoms ranged widely, and most plants showed both diseased and healthy branches. In severe cases, entire sections of the plant were defoliated. Symptoms resembled those described for oleander leaf scorch (OLS) caused by the bacterium Xylella fastidiosa in the United States (3). This bacterium has been reported in coffee and citrus plants in Costa Rica. Sixty plants from five different places were sampled and tested using ELISA (Agdia Inc., Elkhart, IN) against X. fastidiosa. Thirty-five plants showed absorbance mean value of duplicate wells greater than the mean of control wells plus three times the standard deviation, and therefore were considered positive. Thirty-three of the sixty samples were processed for an immunofluorescence assay modified from Carbajal et al. (1) with antibody to X. fastidiosa (Agdia Inc.). Thirteen samples showed fluorescent rod-shaped bacilli with morphology similar to those observed from a pure culture of X. fastidiosa obtained from coffee. Ten of these thirteen samples were positive by ELISA. DNA extracts (2) from three of the oleander plants with high ELISA absorbance values were tested by nested PCR with primer pair 272-1/272-2 followed by the pair 272-1 int/272-2 int (4). Two of the samples were positive for the bacterium and one of the PCR products was cloned and sequenced in both directions (GenBank Accession No. EU009615). The negative (PCR mix) and positive (pure culture of X. fastidiosa isolated from grapevine) controls for nested-PCR were indeed negative and positive, respectively. The BLAST program was used to compare the sequence to the nucleotide collection (nr/nt) and Microbe Assembled Genomes databases in GenBank. All matches corresponded to X. fastidiosa sequences. The sequence showed 97% similarity with strains Found-4 (coffee strain from Brazil) and Found-5 (citrus strain from Brazil) and 96% similarity with strain Ann-1 from oleander in California. On the basis of serological, microscopic, and molecular detection of X. fastidiosa from oleander exhibiting symptoms of OLS similar to those reported in the literature, this pathogen likely is causing the symptoms we observed in Costa Rica. References: (1) D. Carbajal et al. Curr. Microbiol. 49:372, 2004. (2) M. J. Green et al. Plant Dis. 83:482, 1999. (3) Q. Huang et al. Plant Dis. 88:1049, 2004. (4) M. R. Pooler and J. S. Hartung. Curr. Microbiol. 31:377, 1995.

Novel lipoarabinomannan-like lipoglycan (CdiLAM) contributes to the adherence of Corynebacterium diphtheriae to epithelial cells

The genus Corynebacterium is part of the phylogenetic group nocardioform actinomycetes. Members of this group have a characteristic cell envelope structure composed primarily of branched long-chain lipids, termed mycolic acids, and a rich number of lipoglycans such as lipoarabinomanans (LAM) and lipomannans. In this study, we identified a novel LAM variant isolated from Corynebacterium diphtheriae named CdiLAM. The key structural features of CdiLAM are a linear alpha-1-->6-mannan with side chains containing 2-linked alpha-D-Manp and 4-linked alpha-D-Araf residues. The polysaccharide backbone is linked to a phosphatidylinositol anchor. In contrast to the LAMs of other members of actinomycetales, CdiLAM presents an unusual substitution at position 4 of alpha-1-->6-mannan backbone by alpha-D-Araf. Unlike the non-fimbrial adhesin 62-72p, CdiLAM did not function as a hemagglutinin to human red blood cells. Experimental evidences pointed to CdiLAM as an adhesin of C. diphtheriae to human respiratory epithelial cells, thereby, contributing to the pathogenesis of diphtheria.

First Report of Xylella fastidiosa in Avocado in Costa Rica

Since the late 1990s, chlorotic mottling, marginal scorch, deformation of leaves, defoliation, shortening of internodes, and branch dieback have been observed in avocado trees (Persea americana Mill.) in Costa Rica. The symptoms are not uniformly distributed in the tree, so some branches are symptomatic while others are not. These symptoms are similar to several leaf scorch diseases caused by the bacterium Xylella fastidiosa Wells (2,4). This bacterium has been detected in coffee and citrus plants in Costa Rica. Of 227 avocado trees tested by double-antibody sandwich (DAS)-ELISA with X. fastidiosa specific antiserum (Agdia Inc., Elkhart, IN) from 2000-2004, 188 were positive. Results of ELISA tests of individual trees varied with the season and branches tested. Fifteen greenhouse-grown, ELISA-negative avocado seedlings were grafted with budwood from an ELISA-positive tree. Eight of these developed scorch symptoms and one also showed chlorotic mottling and deformation, showing that the disease is graft transmitted. All of these features are characteristic of diseases caused by X. fastidiosa (2,4). Transmission electron microscopy of leaf petioles from three field trees positive by ELISA, revealed rod-shaped bacilli approximately 1.6 to 2.0 μm long and 0.3 μm in diameter with a rippled cell wall inside xylem vessels and embedded in a matrix; morphology and measurements that are consistent with those reported for X. fastidiosa (2). DNA extraction and PCR attempts have been limited by mucilaginous sap from avocado. Positive PCR results (approximately 472-bp band) were obtained from two of the grafted seedlings and seven field trees from two distinct geographical locations (Alajuela and San José provinces) with DNA extractions from the plant sap using DNeasy Plant Mini Kit (Qiagen GmbH, Hilden, Germany) following a modified protocol (1) and nested PCR (3). Four of the PCR products, including one from the grafted seedlings, were cloned and sequenced in duplicate. GenBank sequences EU021997 to EU022000 present 99 to 100% sequence identity to a Pierce's disease strain from California (Temecula1) and 94 to 95% to a citrus variegated chlorosis strain from Brazil (Found-5). Several attempts have been made to isolate the bacterium in 'periwinkle wilt' and buffered cysteine-yeast extract media with negative results, probably because of the rapid production of mucilaginous sap when the avocado tissues were sampled. To our knowledge, this is the first report of X. fastidiosa in avocado trees. References: (1) M. J. Green et al. Plant Dis. 83:482, 1999. (2) S. S. Hearon et al. Can. J. Bot. 58:1986, 1980. (3) M. R. Pooler and J. S. Hartung. Curr. Microbiol. 31:377, 1995. (4) A. H. Purcell et al. Phytopathology 89:53, 1999.

Aspectos histopatológicos da adenomiose em úteros bovinos nas diferentes fases do ciclo estral

Relacionaram-se as características da adenomiose com as fases do ciclo estral em 61 peças de úteros de bovinos colhidas em matadouros. A adenomiose foi classificada em superficial e profunda. A fase do ciclo estral foi estimada pela morfologia, pela coloração e pela vascularização do corpo lúteo e presença ou não de folículos ovarianos maiores que 8mm. Os animais que estavam em anestro (n=11) apresentaram a menor ocorrência de adenomiose (8,2%), e os que estavam na fase lútea média (n=21), a maior (31,0%). Nas fases lútea inicial (n=13) e folicular (n=16) as ocorrências foram semelhantes, 18,0 e 22,9%, respectivamente. A maior porcentagem de adenomiose profunda ocorreu nas fases lútea inicial e média, 45,0 e 47,4%, respectivamente, e durante o anestro e a fase folicular foram de 20,0 e 14,3%, respectivamente. Os resultados sugerem que a fase do ciclo estral influencia na ocorrência de adenomiose e no grau de infiltração miometrial das glândulas endometriais.

Active control of type-I edge-localized modes with n=1 perturbation fields in the JET tokamak

Type-I edge-localized modes (ELMs) have been mitigated at the JET tokamak using a static external n=1 perturbation field generated by four error field correction coils located far from the plasma. During the application of the n=1 field the ELM frequency increased by a factor of 4 and the amplitude of the D(alpha) signal decreased. The energy loss per ELM normalized to the total stored energy, DeltaW/W, dropped to values below 2%. Transport analyses shows no or only a moderate (up to 20%) degradation of energy confinement time during the ELM mitigation phase.

Driving midgut-specific expression and secretion of a foreign protein in transgenic mosquitoes with AgAper1 regulatory elements

The Anopheles gambiae adult peritrophic matrix protein 1 (AgAper1) regulatory elements were used to drive the expression of phospholipase A2 (PLA2), a protein known to disrupt malaria parasite development in mosquitoes. These AgAper1 regulatory elements were sufficient to promote the accumulation of PLA2 in midgut epithelial cells before a blood meal and its release into the lumen upon blood ingestion. Plasmodium berghei oocyst formation was reduced by approximately 80% (74-91% range) in transgenic mosquitoes. Blood-seeking behaviour and survival of AgAper1-PLA2 transgenic mosquitoes were comparable to sibling wild-type mosquitoes, while fertility was substantially lower. Ultrastructural studies suggest that decreased fitness is a consequence of internal damage to midgut epithelial cells.

First Report of Xylella fastidiosa Infecting Citrus in Costa Rica

Citrus variegated chlorosis (CVC) is an important disease mainly of sweet orange (Citrus sinensis (L.) Osbeck) cultivars. It was first described in Brazil in the state of Sā Paulo in 1987 (4). The disease has spread to all Brazilian states that grow citrus and is affecting more than one-third of the orange trees grown in Brazil. CVC is caused by Xylella fastidiousa, a xylem-limited, gram-negative bacterium. During the last 4 years, symptoms including leaf interveinal chlorosis, stunting, canopy dieback, and hard and undersized fruits, similar to those caused by CVC (3), appeared in sweet orange trees used as shade plants for coffee plantations and as fence posts in Costa Rica. Necrotic lesions on the abaxial side of the leaves as reported in Brazil were rarely observed. Leaf petiole samples from 25 symptomatic sweet orange trees reacted positively with a X fastidiosa-specific antiserum (AGDIA Inc., Elkart, IN) in a double-sandwich antibody enzyme-linked immunosorbent assay (DAS-ELISA). A fastidious, gram-negative bacterium identified as X. fastidiosa using DAS-ELISA was isolated on perwinkle wilt (PW) medium plates (1) from citrus stems showing CVC symptoms, but not from asymptomatic trees. The isolated colonies were circular and opalescent with diameters of 2 to 3 mm and were clearly visible within 6 to 7 days after streaking. Petiole sections from symptomatic plants observed with scanning electron microscopy showed rod-shaped bacteria with rippled cell walls tightly packed in xylem vessels, as described for X. fastidiosa previously (2), and with transmission electron microscopy, the bacteria were morphologically similar to those reported previously for CVC (2). To our knowledge, this is the first report of X. fastidiosa associated with citrus in Costa Rica. References: (1) M. J. Davis et al. Curr. Microbiol. 6:309, 1981. (2) J. S. Hartung et al. Phytopathology 84:591, 1994. (3) R. F. Lee et al. Summa Phytopathol. 19:123, 1993. (4) V. Rossetti et al. 1990, C.R. Acad. Sci. (Paris) 310:345-349.

First Report of Citrus Blight in Costa Rica

Citrus blight (CB), causing a chronic decline of citrus, has been an important disease in Florida for over 100 years. CB was first reported in Brazil in the 1980s and is now responsible for the removal of nearly 10% of the trees from production annually. No causal agent has been identified, but CB has been root-graft transmitted to healthy trees, suggesting that the causal agent is infectious (3). Since 1997, CB symptoms were observed in several groves in northern Costa Rica, the most important citrus area of approximately 25,000 ha. Symptoms observed include a general decline and wilt of the tree canopy, off-color leaves, leaf drop, twig dieback, small fruit, delayed blossom, poor growth, and death. A survey near Guanacaste revealed CB symptoms in 7-yr-old Valencia and Pineapple orange trees (Citrus sinensis (L.) Osbeck) grafted on Carrizo citrange (C. sinensis (L.) Osbeck × Poncirus trifoliata (L.) Raf.) rootstock. Since 1997, 6% of the trees in this area have been replanted annually because of CB symptoms. Similar situations were observed in other groves in the northern citrus area. Dot immunobinding assays (DIBA) (1) were used to detect the P12 protein associated with CB with 20 of 22 trees showing CB-like symptoms giving a positive test. Zinc (Zn) accumulation in trunk wood and water uptake tests were done according to Roistacher (2) in 8 healthy and 20 symptomatic trees which were positive for CB using DIBA. The average Zn concentration of 16 declining trees was 4.6 ± 1.9, whereas the average concentration for 8 healthy trees was 2.0 ± 0.9. The average water uptake in 1 min was 14 ml for healthy trees, and virtually zero for the 20 symptomatic trees. These diagnostic tests confirm the presence of CB in the northern citrus area of Costa Rica, and the surveys indicate the disease is beginning to spread and become economically important. To our knowledge, this is the first report of CB in commercial citrus in Costa Rica. References: (1) K. S. Derrick et al. Plant Dis. 74:168, 1990. (2) C. N. Roistacher. Pages 57-66 in: Graft-Transmissible Diseases of Citrus. Handbook for Detection and Diagnosis. C.N. Roistacher, ed. Food and Agriculture Organization, Rome, 1991. (3) D. P. H. Tucker et al. Plant Dis. 68:979, 1984.

Occurrence of Coffee ringspot virus, a Brevipalpus Miteborne Virus in Coffee in Costa Rica

Coffee ringspot virus (CoRSV) (family Rhabdoviridae) is transmitted by Brevipalpus phoenicis (Geijskes) (Acari: Tenuipalpidae). Coffee ringspot disease was first reported in coffee plants from Brazil in 1939 (1). In August 2000, severe symptoms of concentric ringspots and "oak leaf" patterns on coffee leaves (Coffea arabica L. cv. Catuai) were observed during field inspections conducted in two areas of San Gabriel de Desamparados, Costa Rica. The disease caused premature fruit and leaf drop in the affected plants. Some areas within the ringspot lesions remained green on senescent leaves. Because CoRSV particles remain restricted to lesion areas (1), this virus has not been purified, and antiserum for virus detection is not available. Therefore, leaves with symptoms were collected and examined by transmission electron microscopy. In ultrathin sections of symptomatic leaves, arrays of rhabdovirus-like particles were associated with the nucleus as described for CoRSV (2). Healthy tissues did not contain similar arrays of bacilliform and bullet-shaped particles. Twenty mites collected from the infected plants at the same locations and time were slide-mounted and identified as B. phoenicis. High populations of this mite were also observed infesting plants of Cajanus cajan L. that were intercropped with coffee at the same location. Sweet orange trees growing in the same fields as shade for the coffee did not show symptoms of citrus leprosis, a disease caused by another Brevipalpus-transmitted virus that was recently reported in Panama (3). To our knowledge, this is the first report of a virus similar to CoRSV in Costa Rica. The spread of this virus, presumably CoRSV, could seriously affect the coffee industry throughout Central America by increasing production costs. It may be necessary to apply one or more foliar acaricides to effectively control the mite vector. References: (1) A. Bitancourt. O. Biol. 5:33, 1939. (2) C. M. Chagas et al. Phytopathol. Z. 102:100, 1981. (3) F. S. Dominguez et al. Plant Dis. 85:228, 2001.

First Report of an Aster Yellows Subgroup 16SrI-B Phytoplasma Infecting Chayote in Costa Rica

An outbreak of a witches' broom disease affected approximately 20% of plants in several chayote (Sechium edule (Jacq.) Schwartz) fields in the commercial production area of the Ujarrás Valley, Cartago Province, Costa Rica during 2000 and 2001. Affected chayote plants exhibited symptoms, including basal proliferation with severe foliage reduction, aborted flowers, and deformed fruits, suggestive of phytoplasmal infection. Two other symptomatic cucurbit species growing near the chayote fields were also identified. These species were tacaco plants (S. tacaco (Pitt.) C. Jeffrey), an edible cucurbit for domestic marketing in Costa Rica, showing severe size reduction of leaves and fruits, and Rytidostylis carthaginensis (Jacq.) Kuntze, a weed in chayote and tacaco fields, exhibiting abnormal tendril proliferation. Plants were analyzed for phytoplasma infection by a nested polymerase chain reaction (PCR) assay, using the universal rRNA primer pair P1/P7 followed by R16F2n/R16R2 (2). Phytoplasmas were detected in all symptomatic samples (18 chayote, 6 tacaco, and 3 weed) tested but were undetectable in all asymptomatic samples (10 chayote, 6 tacaco, and 2 weed). Restriction fragment length polymorphism (RFLP) analysis of PCR products (16S rDNA sequences) by separate digestion with eight restriction enzymes (RsaI, HhaI, KpnI, BfaI, HaeIII, HpaII, AluI, MseI) revealed that a phytoplasma belonging to subgroup 16SrI-B in the aster yellows phytoplasma group (16SrI) was associated with chayote witches' broom (CWB). The same or very similar phytoplasmas were found in both symptomatic tacaco and R. carthaginensis plants. Phylogenetic analysis of 16SrDNA sequences also confirmed the CWB phytoplasma to be most similar to members of subgroup 16SrI-B. Similar diseases in chayote and other cucurbits have been reported in Brazil (3), Taiwan (1), and Mexico (4). The CWB phytoplasma differs from the phytoplasma (16SrIII-J subgroup) associated with chayote in Brazil. The identities of phytoplasmas associated with cucurbits in Taiwan and Mexico are unknown. The occurrence of an aster yellows group phytoplasma in chayote may pose a potential threat to continued production and exportation of this cash crop. To our knowledge, this is the first report of 16SrI-B subgroup phytoplasmas in naturally infected cucurbits in Costa Rica. References: (1) T. G. Chou et al. Plant Dis. Rep. 60:378, 1976. (2) I.-M. Lee et al. Int. J. Syst. Bacteriol. 48:1153, 1998. (3) H. G. Montano et al. Plant Dis. 84:429, 2000. (4) E. Olivas. Rev. Fitopatol. (Lima) 13:14, 1978.

First Report of Xylella fastidiosa Infecting Coffee in Costa Rica

In 1995, severe symptoms were observed on 'Caturra' and 'Catuaí' coffee (Coffea arabica L.) varieties in farms in the southern part of the Central Valley in Costa Rica. Symptoms were reduced leaf size, malformation of leaves, curling of leaf edges, shortening of internodes, and severe leaf chlorotic mosaic, which sometimes became necrotic. Abortion of flowers and young beans was also observed, with a reduction in yield. Plants also showed irregular growth with an atypical curling appearance that gave rise to the Spanish name "crespera." Ten and three healthy plants were inoculated by grafting in the greenhouse, using infected and healthy budwoods, respectively. Approximately 6 months after inoculation, 3 of 10 grafted plants with infected budwoods showed symptoms of leaf chlorosis, curling, and malformation of leaves and bunched new flushes. Samples of 39 symptomatic plants collected from the field and samples of 3 healthy plants maintained in the greenhouse were tested by enzyme-linked immunosorbent assay (ELISA). All (100%) analyzed symptomatic samples were positive for X. fastidiosa, and all healthy controls were negative. The symptoms observed in Costa Rica are different from those described for coffee leaf scorch in Brazil (1,2), but the climatological conditions and soil type present in Costa Rica are also very different from the areas where X. fastidiosa occurs in Brazil. Leafhoppers were collected randomly in one of the most affected regions. Graphocephala permagna and Erythrogonia sonora were the most frequent insect species found associated with coffee. In ELISA, 34.5% (10 of 29) and 23.8% (5 of 21) of the collected specimens belonging to G. permagna and E. sonora, respectively, tested positive for X. fastidiosa. These positive ELISAs do not necessarily mean that the insect is a vector. The results presented here extend the known geographic distribution of X. fastidiosa. To our knowledge, this is the first report of X. fastidiosa in coffee in Costa Rica. References: (1) M. J. G. Beretta et al. Plant Dis. 80:821, 1996. (2) de Lima et al. Plant Dis. 82:94, 1998.

[Progressive multifocal leukoencephalopathy. Role of imaging in its diagnosis. Perspectives]

We review five cases of Progressive Multifocal Leukoencephalopathy (PML), confirmed by biopsy in three cases and by LCR JC virus research by PCR (polymerase chain reaction) in two cases. We analysed the lesions and different forms of imagiological presentation, concerning location, mass effect, contrast enhancement and progress, and emphasize the importance of some atypical patterns. Reference is also made to the role of imaging in its diagnosis and new techniques, such as Spectroscopy and Transfer Magnetization, to avoid brain biopsy.

Lymphoproliferative responses to mitogens and prepared antigens of M. avium complex in patients with HIV infection

Published reports have demonstrated that antigens of Mycobacterium avium complex (MAC) can suppress the normal response to mitogens in lymphoproliferation assays. We therefore studied the lymphoproliferative (LP) function of PBMC from 55 HIV-infected patients and 16 controls in response to mitogens with and without MAC antigen. As expected, LP responses decline with progressive decline in CD4 count; MAC antigen in combination with PHA further suppresses that response in a dose-dependent manner. More relevant were the LP responses in those with CD4 counts less than 100. All patients with MAC disease had poor responses (stimulation index, SI < 10) to PHA or anti-CD3 with or without MAC antigen. Those who did not have nor subsequently developed MAC were both good (SI > 10) or poor responders (SI < 10). The suppressive effect of MAC on lymphocyte function may serve as a weak virulence factor which is only relevant in severely immunocompromised HIV patients.

Retroviral vector-mediated gene transfer into keratocytes in vitro and in vivo

PURPOSE

To determine the potential of somatic gene transfer as a technique for modulating corneal wound healing after superficial keratectomy.

METHODS

The transduction of human and rabbit keratocytes with beta-galactosidase and herpes simplex virus thymidine kinase genes was performed. In vitro, human and rabbit keratocytes were transduced with retroviral vectors bearing beta-galactosidase or HStk (herpes simplex virus thymidine kinase) genes. In vivo, rabbit keratocytes were transduced by topical application of vector supernatant after a superficial keratectomy. In vitro and in vivo, expression of the beta-galactosidase gene was examined with histochemical staining. In vitro, ganciclovir cytotoxicity in HStk gene-transduced keratocytes and bystander effect in co-cultures of HStk(+) and HStk(-) keratocytes were measured by determining the degree of confluency of cells in 6-well plates after 10 days of incubation. Corneal haze in rabbits was measured after transduction with Hstk and subsequent treatment with topical ganciclovir.

RESULTS

In vitro, both human and rabbit keratocytes were transduced successfully with both beta-galactosidase and HStk genes. Transduction efficiency was greater with human (22%) than with rabbit (16%) cells, and both HStk-transduced cell lines showed dose-dependent ganciclovir cytotoxicity and a significant bystander effect. In vivo, expression of beta-galactosidase within vimentin-positive corneal stromal cells confirmed transduction of keratocytes in the rabbit after superficial stromal keratectomy with an efficiency of 25% to 40%. Postoperative application of topical ganciclovir reduced corneal stromal haze in rabbits.

CONCLUSIONS

The ability to genetically transduce stromal keratocytes provides a new strategy for understanding the important cellular and molecular events that influence corneal wound healing, thus offering a potential approach to decrease or prevent corneal haze and scarring after superficial keratectomy.

First Report of the Cymbidium Mosaic Potexvirus (CymMV) Infecting the Terrestrial Orchid Phaius tankervilliae in Costa Rica

In 1996, plants of the terrestrial orchid Phaius tankervilliae from a nursery in the Central Valley of Costa Rica were observed with mild to severe foliar symptoms of chlorotic streak. No differences were observed in growth, bulb production, flowers, or flowering time between symptomatic and asymptomatic plants, except the symptomatic plants had earlier senescence. Occasionally, the flowers displayed symptoms of chlorosis and white rings in the sepals. Extracts from symptomatic leaves were concentrated by differential centrifugation and analyzed after sucrose gradients. Negative staining of fractions from gradients from symptomatic plants showed the presence of filamentous viral particles 500 by 17 nm. Purified particles contained a single major protein of about 28 kDa as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and a single RNA of about 7 kb, which is greater than the 6.2 kb reported (GenBank). These data suggest the presence of a potexvirus in symptomatic plants (1,2). In enzyme-linked immunosorbent assays, symptomatic plants reacted strongly with antiserum specific for Cymbidium mosaic potexvirus (CymMV). This is the first report of CymMV in P. tankervilliae in Costa Rica. References: (1) J. A. Frowd and J. H. Tremaine. Phytopathology 67:43, 1977. (2) H. T. Hsu et al. Phytopathology 82:491, 1992.

Survival of allochthonous bacteria in still mineral water bottled in polyvinyl chloride (PVC) and glass

The mortality of Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae and Pseudomonas aeruginosa, based on the culturability of these bacteria, was assessed in non-carbonated mineral water, bottled in polyvinyl chloride (PVC) containing the indigenous flora, sterile mineral water bottled in PVC, sterile mineral water in glass containers, and sterile tap water in glass containers. There was a general decrease in the culturability of these organisms in the four test waters, except that Ps. aeruginosa grew in sterile tap water. Escherichia coli and Kl. pneumoniae had the highest mortality rates under the conditions tested, while Ent. cloacae had a very low and constant mortality rate that would have resulted in the persistence of this organism in mineral water for a long period of time. After a sharp initial decrease in culturability, Ps. aeruginosa also had a very low mortality rate in mineral water bottled in PVC.

Pathological changes induced by BaH1, a hemorrhagic proteinase isolated from Bothrops asper (Terciopelo) snake venom, on mouse capillary blood vessels

The pathological changes induced in capillaries by BaH1, a hemorrhagic metalloproteinase isolated from the venom of Bothrops asper, were studied after i.m. injection in mouse gastrocnemius. Hemorrhage was observed macroscopically, and corroborated histologically, within the first 5 min. At the ultrastructural level, the earliest changes in endothelial cells, observed 1 min after toxin administration, consisted of a decrease in the number of pinocytotic vesicles, the presence of blebs and cytoplasmic projections pinching off to the vascular lumen and the detachment of endothelial cells from the surrounding basal lamina. These processes occurred concomitantly with a thinning of endothelial cells. In capillaries undergoing more advanced degenerative stages, there were gaps or breaks in endothelial cells through which erythrocytes were escaping to the extravascular space. In these cells, the basal lamina was usually absent. Throughout this process, intercellular junctions remained apparently intact and no evidence was found of extravasation through widened intercellular junctions. In addition to this morphological pattern of degeneration, some capillaries presented swollen endothelial cells with dilated endoplasmic reticulum and lacking pinocytotic vesicles. Many capillaries contained platelet plugs and fibrin. Thus, hemorrhage induced by BaH1 occurs per rhexis, as has been also described for other venoms and hemorrhagic toxins.

Ultrastructural alterations in mouse capillary blood vessels after experimental injection of venom from the snake Bothrops asper (Terciopelo)

Histological and ultrastructural alterations in capillary blood vessels were studied at various time intervals after im injection of 50 micrograms of Bothrops asper snake venom in mouse gastrocnemius muscle. Hemorrhage was observed as early as 5 min after envenomation, as abundant erythrocytes appeared in the interstitial space. Ultrastructural observations revealed two different patterns of pathological changes: in the majority of damaged capillaries, endothelial cells had blebs and cytoplasmic projections pinching off to the lumen. This phenomenon was observed together with a decrease in the number of pinocytotic vesicles, with endothelial cells becoming very thin. As an apparent consequence of this process, some endothelial cells had evident gaps in their continuity. In addition, basal laminae surrounding these capillaries were altered and discontinuous. Other endothelial cells underwent a morphologically different process of degeneration, characterized by swelling of the endoplasmic reticulum and of the cytosol. These cells had a diffuse appearance and their basal laminae were discontinuous or absent. No major changes in the intercellular junctions were noticed in damaged endothelial cells. Samples obtained 30 and 60 min after venom injection were devoid of normal capillaries in many areas, and only diffuse remnants of their structure were found. Many altered capillaries had platelet aggregates and fibrin, the latter also being observed in the interstitial space. It is concluded that B. asper venom induces rapid and drastic pathological effects on capillaries leading to hemorrhage per rhexis i.e., erythrocytes probably escape through gaps in damaged endothelial cells and not through widened intercellular junctions.

[Use of the plasma coagulation method for ultrastructural analysis of biological specimens]

Biological particulate specimens, including Saccharomyces cerevisiae yeast, bovine spermatozoa and human blood cells (normal erythrocytes and leukemic cells) were processed for scanning and transmission electron microscopy using the coagulated plasma technique. The specimens were suspended in frozen and thawed plasma; later, coagulation was induced by adding CaCl2. The clot was cut into small pieces and processed as tissue fragments. The technique is an useful tool when processing biological particulate specimens for electron microscopy.