Stem Lesions Research Articles

DIPG-23. SINGLE CASE REPORT OF LOW DOSE RADIOTHERAPY AND CHEMOTHERAPY IN THE TREATMENT OF DIPG

A 3 year-old girl, was noted to have progressive gait problem since Nov. 2017 and brought to hospital for checkup. Brain MRI on Jan. 2018 showed T2 hyperintensity infiltrative pontine lesion, favoring diffuse infiltrative pontine glioma and mild obstructive hydrocephalus, received VP-shunting on Jan. 15, 2018. Due to the refusal of surgical biopsy for tissue proof, we started the radiotherapy from Jan. 24, 2018, using Rapidarc technique with 6MV photon energy to treat the brain stem lesion, ended on Feb. 24, 2018 with total dose of 25.5Gy in 17 fractions as our usual practice. Following the completion of radiotherapy, we started the adjuvant chemotherapy using 1-week on, 1-week off regimen of temozolomide using dosage of 75 mg/sq-m/day, and this patient’s general condition returned back to nearly normal. Serial follow-up images of brain MRI on 04/30/2018, 08/01/2018, 11/30/2018, 02/26/2019, 05/30/2019, 08/28/2019 showed slow progression of the pontine lesion, without the development of contrast enhanced new lesion. She maintained the functional independent until Sep. 2019, she was noted to have symptoms of ataxic gait, esotropia and choking on drinking liquid. We started the retreatment of radiotherapy from Oct.7, 2019, using same technique, ended on Nov. 5, 2019 with total dose of 30Gy in 20 fractions. The symptoms improved partially after the treatment, with residual weakness over left extremity. We are still treating the patient with adjuvant temozolomide, and she has survived most of time functionally independent in these 2 years.

First Report of Cercospora apiicola Causing Leaf Spots and Stem Lesions on Celery in China.

Celery (Apium graveolens L.) is a vegetable crop cultivated widely in the Mediterranean, Europe and parts of Asia. From March to May in 2014, leaf spots and stem lesions were observed on celery plants in Yanqing (116°03'E, 40°32'N), Beijing and Chengdu (104°06'E, 30°67'N), Sichuan Province. Plants developed 0.3-1.8 cm diameter subcircular leaf spots with brown centers surrounded by pale yellow halos. Spots on leaves were amphigenous. Necrotic areas on stems were subcircular to elongated, pale brown to brown. Plants in five greenhouses were surveyed with 30 to 60% disease incidence. Necrotic tissue from 8 stems and 12 leaves were cut from the margins of lesions and divided into two parts. One part was treated with lactophenol and used for microscopic examination. The other part was surface sterilized with 4% sodium hypochlorite for 2 min, rinsed three times in sterile water, placed onto 2% malt extract agar (MEA), and incubated at 26°C for seven days with natural daylight. Stromata on leaves and stems were not well developed. Four-to-ten conidiophores (15.3-56.5 × 2.8-5.5 μm) formed in fascicles, emerged through stomata or erupted through the cuticle. Conidia (n=50) were 60-135 × 2.5-4.5 μm, solitary, septate, cylindrical to obclavate-cylindrical, hila thickened and darkened. Colonies were white to smoke-gray, and aerial mycelia were sparse to moderate. Morphological characteristics of the pathogen were similar to Cercospora apiicola (Groenewald et al. 2006; Groenewald et al. 2013). The gDNA of 20 isolates was extracted from mycelium using the Plant Genomic DNA Kit (Tiangen, China). The internal transcribed spacers (ITS), actin (ACT), translation elongation factor 1-α (TEF1) and histone H3 (HIS3) regions were amplified with primer pairs ITS1/ITS4 (Groenewald et al. 2013), ACT-512F/ACT-783R (Carbone and Kohn 1999), EF1-728F/EF1-986R (Carbone and Kohn 1999), CYLH3F/CYLH3R (Crous et al. 2006). Phylogenetic analysis of multiple genes (Bakhshi et al. 2018) was conducted with the neighbor-joining method using MEGA7. The sequences of our isolate (QC14030702) and five published sequences of C. apiicola were clustered into one clade with a 99% confidence level. The sequences of QC14030702 have been deposited in GenBank with accessions KU870468 for ITS, KU870469 for ACT, KU870470 for TEF1, and KU870471 for HIS3. Pathogenicity of the isolates was tested on plants (cv. Jia Yuan Xi Yang Qin). Because the pathogen sporulated poorly on various media, mycelial fragments were sprayed on leaves in a suspension of 1×106 mL-1 in a greenhouse (temperature 26±0.5°C; RH 98%; photoperiod 12 h). Healthy plants were sprayed with sterilized water as controls. Three replicates of every isolate were conducted, and each replicate included 5 celery plants. After 7 days, leaf spots appeared on all inoculated plants, which were similar to those on celery in the field. All control plants remained asymptomatic. Re-isolation of the fungus from infected tissues showed same morphological and cultural characteristics of C. apiicola as the original isolates. C. apiicola has been reported in Greece, Korea, South Korea and Venezuela on celery, but never been reported in China (Farr and Rossman 2020). C. apiicola potential threatens celery production, and this the first report of the disease in China.

Operative findings and outcome of microvascular decompression/adhesiolysis for trigeminal neuralgia in multiple sclerosis without demyelinating brain stem lesions

ObjectiveTrigeminal neuralgia (TN) in multiple sclerosis (MS) poses several challenges for treatment. Although these patients often have typical attacks, they may not be considered as candidates for microvascular decompression (MVD). Here we report on surgical findings and long term follow-up of MVD/ adhesiolysis in a series of patients with multiple sclerosis but without demyelinating brain stem lesions. MethodsFifteen patients with MS-related TN underwent MVD/ adhesiolysis. Demyelinating brain stem lesions were excluded radiologically. Outcome of the intervention was assessed according to the Barrow Neurological Institute (BNI) pain intensity score at 3, 12, 24 months follow-up and at the last available follow-up (mean 88.2 months, range 38–146). ResultsAll 15 patients benefited from MVD/adhesiolysis and were pain free on the first day of surgery. Intraoperative findings included arterial contact in 7/15 (47 %) patients, venous contact in 9/15 (60 %), and prominent arachnoid thickening in 12/15 (80 %). The distribution of the BNI pain intensity scores showed marked improvement at all follow-up evaluations. Five patients underwent repeat MVD/adhesiolysis for pain recurrence at a mean of 43 months after the first surgery. Long term evaluation at the last available follow-up demonstrated favorable outcome in 13/15 patients (BNI I-IIIa) (87 %), while 2/15 patients had limited benefit (BNI IV). ConclusionsMS-related TN in patients without demyelinating brain stem lesions may be related either to vascular conflicts or to focal arachnoiditis at the trigeminal nerve entry zone. MVD/ adhesiolysis may be considered as a useful treatment option in this subgroup of patients with regard to long term outcome.

Resistance to Anthracnose (Colletotrichum lentis, Race 0) in Lens spp. Germplasm

Anthracnose, caused by the fungal pathogen Colletotrichum lentis, is a severe disease of lentil (Lens culinaris) causing premature defoliation, necrotic stem lesions that lead to plant wilting and death in susceptible varieties. Two races of C. lentis (0 and 1) have been described so far. Race 0 is the most virulent one and limited genetic resistance is available to date. To address this scarcity of resistance, we screened a germplasm collection covering different Lens spp. originating from different countries for C. lentis race 0 resistance. Leaf and stem damage and plant mortality were assessed on seedlings inoculated under controlled conditions. A significant variability was observed among accession. Most of the collection studied was highly susceptible, but some levels of resistance were identified in about 15% of the accessions. The highest levels of resistance were identified in L. ervoides accessions PI572330, PI572334 and PI572338. Moderate resistance was also identified in 10 L. culinaris ssp. culinaris accessions but not in the remaining species studied. Selected accessions showed potential to integrate several breeding programs.

Resistance of kiwifruit cultivars to ceratocystis wilt: An approach considering the genetic diversity and variation in aggressiveness of the pathogen

AbstractKiwifruit (Actinidia spp.) is native to southern China, but was first cultivated in New Zealand and then spread worldwide. Emerging diseases such as ceratocystis wilt have attracted the attention of kiwifruit growers due to the great losses observed in southern Brazil. Effective control can be achieved by screening for resistance, but the genetic variability of the pathogen must be considered. Thus, this study aimed to assess the genetic diversity and variation in aggressiveness of Ceratocystis isolates from kiwifruit in southern Brazil and then evaluate the resistance of kiwifruit cultivars with the most aggressive isolates. A collection of 46 isolates were obtained from southern Brazil and 14 simple‐sequence repeat (SSR) markers was successfully used for genotyping. Out of 14 markers, 13 were polymorphic and identified 26 genotypes. Fourteen distinct genotypes were tested on a susceptible cultivar to select the most aggressive ones. Finally, inoculation with an equal mixture of five of the most aggressive isolates was used to evaluate the resistance of seven kiwifruit cultivars: Red Arguta, Green Arguta, Allison, Chieftain, Hayward, Monty, and Tomury. Cultivars varied in levels of susceptibility, with disease severity ranging from 40% to 100%. Considering the length of stem lesions, Chieftain showed the lowest level of severity at 40%, while no wilt symptoms were observed at 45 days after inoculation. In addition to the seven cultivars, a half‐sibling progeny with 618 plants of the rootstock cv. Bruno was also assessed, but only seven individuals were resistant. These seven plants can be cloned and used as resistant rootstocks in commercial orchards.

First Report of Rhizoctonia solani AG 4 Causing Root and Stem Rot of Stevia in Delaware and Maryland

HomePlant DiseaseVol. 104, No. 11First Report of Rhizoctonia solani AG 4 Causing Root and Stem Rot of Stevia in Delaware and Maryland PreviousNext DISEASE NOTES OPENOpen Access licenseFirst Report of Rhizoctonia solani AG 4 Causing Root and Stem Rot of Stevia in Delaware and MarylandA. C. Kessler and A. M. KoehlerA. C. Kesslerhttp://orcid.org/0000-0002-4524-8056Department of Plant and Soil Sciences, University of Delaware, Newark, DE 19716Search for more papers by this author and A. M. Koehler†Corresponding author: A. M. Koehler; E-mail Address: [email protected]http://orcid.org/0000-0002-9514-9910Department of Plant and Soil Sciences, University of Delaware, Newark, DE 19716Search for more papers by this authorAffiliationsAuthors and Affiliations A. C. Kessler A. M. Koehler † Department of Plant and Soil Sciences, University of Delaware, Newark, DE 19716 Published Online:31 Aug 2020https://doi.org/10.1094/PDIS-01-20-0214-PDNAboutSectionsView articlePDFSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat View articleStevia (Stevia rebaudiana [Bertoni] Bertoni) is an emerging crop in the United States used as a nonnutritive sweetener. Stevia seedlings are established in greenhouses by propagative cuttings or from seeds. Seedlings are then transferred to the field approximately 12 to 15 weeks after sowing. Symptomatic seedlings were observed in newly transplanted field sites in Georgetown, Delaware, and Salisbury, Maryland, throughout May and June 2019. Symptoms included wilting, stem lesions, shredded stem tissue, and root necrosis that resulted in the death of approximately 3 to 5% of plants in each field. At the onset of disease, five symptomatic plants were collected at each site, and 3-cm pieces of root and stem tissue were surface disinfested and plated onto potato dextrose agar, amended with 50 µg/ml of penicillin G and streptomycin sulfate. Isolates were incubated at 23°C for 7 days and observed for colony morphology. Tan colonies had mycelia with right-angle branching, septations near the branch, and three to eight nuclei per cell, consistent with the description of Rhizoctonia solani Kuhn (Sneh et al. 1991). After extracting DNA, pathogen identification was confirmed for a representative isolate from each state by sequencing of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA using primers ITS4/ITS5 (White et al. 1990). All isolates were identified as R. solani AG 4 (99.5% sequence identity with GenBank accession no. MN106332.1). Sequences were deposited in GenBank as accession numbers MT009023 to MT009024 and MT009025 to MT009026, for Delaware and Maryland isolates, respectively. Koch’s postulates were confirmed twice for each of the isolates by inoculating 15-week-old greenhouse-grown stevia plants in 8-cm-diameter pots in sterile soilless media. Colonized oat grains served as the inoculum. Oats were sterilized on three consecutive days and then inoculated with colonized agar plugs of the Delaware or Maryland isolate. Oats were incubated at room temperature for 5 days to allow fungi to thoroughly colonize the oats. Three colonized oat grains were buried at a depth of 5 mm, 2 cm from the base of each plant, with four replicate plants for each isolate. Two noninoculated oat grains were buried in each of the four plants that served as the control. Plants were maintained at 26 ± 2°C, watered once daily with a 12-h/12-h light cycle, and observed over a 5-week period. Within 2 weeks, plants inoculated with the Delaware isolate exhibited symptoms of wilting, stem lesions, stem shredding, root necrosis, and plant death. Plants inoculated with the Maryland isolate developed symptoms at 4 weeks, and control plants did not develop symptoms. Stem and root pieces were collected and surface disinfested, and R. solani AG 4 was reisolated from all inoculated plants and confirmed by culture morphology and sequencing (99.5% sequence identity with GenBank accession no. MN106332.1). To our knowledge, this is the first report of R. solani AG 4 causing root and stem rot of stevia in North America. Hilal and Baiuomy (2000) reported root rot of stevia by R. solani in Egypt. Plant establishment is the most expensive component of U.S. production, so it is important to monitor pathogens with potential to kill transplanted stevia and reduce overall plant stands. Current practices aim for perennial production of stevia in the southeast United States, and diseases that reduce establishment affect yield not only in the first year but also in all subsequent years of production.The author(s) declare no conflict of interest.

White Leaf Spot Caused by Neopseudocercosporella capsellae: A Re-emerging Disease of Brassicaceae.

White leaf spot can cause significant damage to many economically important Brassicaceae crops, including oilseed rape, vegetable, condiment, and fodder Brassica species, and recently has been identified as a re-emerging disease. The causal agent, Neopseudocercosporella capsellae, produces foliar, stem, and pod lesions under favorable weather conditions. N. capsellae secretes cercosporin, a non-host specific, photo-activated toxin, into the host tissue during the early infection process. The pathogen has an active parasitic stage on the living host and a sexual or asexual saprobic stage on the dead host. Where the sexual stage exists, ascospores initiate the new disease cycle, while in the absence of the sexual stage, conidia produced by the asexual stage initiate new disease cycles. Distribution of the pathogen is worldwide; however, epidemiology and disease severity differ between countries or continents, with it being more destructive in Subtropical, Mediterranean, or Temperate climate regions with cool and wet climates. The pathogen has a wide host range within Brassicaceae. Brassica germplasm show varied responses from highly susceptible to completely resistant to pathogen invasion and significant susceptibility differences are observed among major crop species. Cultural practices only provide effective disease control when the climate is not conducive. An increase in the susceptible host population and favorable weather conditions have together favored the recent rise in white leaf spot disease occurrence and spread. The lack of understanding of variation in pathogen virulence and associated resistant gene sources within brassicas critically limits the potential to develop efficient control measures.

MRI features of intra-axial histiocytic brain mass lesions

To describe MRI features, including diffusion-weighted imaging (DWI), magnetic resonance spectroscopy (MRS), and perfusion-weighted imaging (PWI), of intra-axial tumour-like presentations of four different subtypes of histiocytosis. The brain MRI findings of 23 patients with histologically proven histiocytosis were reviewed retrospectively (11 Langerhans cell histiocytosis [LCH], eight Erdheim-Chester disease [ECD], one overlap form LCH/ECD, two Rosai-Dorfman disease [RDD], and one haemophagocytic lymphohistiocytosis [HLH]) with single or multiple enhancing intraparenchymal brain lesions. Histiocytic brain mass lesions show some similar MRI features including Supra and/or infratentorial and/or paraventricular subcortical well-delineated masses, linear ependymal enhancement along the ventricles and brain stem lesions. Masses always present with mixed hyper- and hypointense signal on T2-weighted imaging (WI). Their enhancement is often homogeneous. Apparent diffusion coefficient (ADC) values are often normal or elevated. The presence of multiple periventricular and subcortical enhancing lesions with mixed signal intensity on T2WI and normal or high ADC values should lead radiologists to consider the diagnosis of histiocytic lesions and search for associated systemic lesions.

First Report of Colletotrichum brevisporum Causing Soybean Anthracnose in China.

In March 2020, widespread anthracnose was observed on soybean (Glycine max) in southeastern Jiangsu (Nantong municipality; 120.53° E, 31.58° N) in China. Plants exhibited irregular brown necrotic lesions in stem and leaves, and pronounced wilting. The symptoms were detected in one soybean field, 0.42 ha, surrounded by healthy wheat fields. Approximately 65% of the soybean plants showed the disease symptoms, and crop yield was reduced by 28-35% with respect the yield achieved in previous years, when no symptoms were observed. The symptoms were consistent with those previously reported for anthracnose on soybean caused by Colletotrichum chlorophyti, C. cliviae and C. gloeosporioides (Barbieri et al. 2017; Mahmodi et al. 2013; Yang et al. 2012). Diseased, 3-week old plants were collected. Small pieces, approximately 1 cm2 in size, of symptomatic tissue were surface sterilized in 1.5% NaOCl for 1 min, and washed twice with sterile ddH2O. The pathogen was isolated and cultured on potato dextrose agar (Song et al. 2020), containing chloramphenicol (50 µg/mL), under darkness at 28 °C for 3 days. Sequence of internal transcribed spacer (ITS), actin (ACT), β-tubulin (TUB2) and glyceraldehyde 3-phosphate dehydrogenase (GAP/span>DH) genes was performed as reported by Yang et al. (2015). Sequences were submitted to GenBank under accession numbers MT361074 (ITS) and MT415548-MT415550 (ACT, TUB2 and GAPDH). Blast search revealed that the amplified sequences had 100% (ITS; C. brevisporum TCHD, MH883805), 97.66% (ACT; C. brevisporum S38, KY986905), 99.06% (TUB2; C. brevisporum PF-2, KY705061) and 100% (GAPDH; C. brevisporum LJTJ27, KP823797) matches to multiple C. brevisporum strains, whereas all reported C. chlorophyti, C. cliviae and C. gloeosporioides strains showed no similarity to at least 2 of the studied genes. Molecular phylogenetic tree constructed using MEGA7 confirmed the identity of the pathogen. ACT and ITS sequences were blasted separately in Muscle (https://www.ebi.ac.uk/Tools/msa/muscle/) and then combined together to make the phylogenetic tree. The evolutionary history was inferred by using the Maximum Likelihood method based on the Tamura 3-parameter model, and the tree with the highest log likelihood (-1749.2186) is shown in Figure 1. The Colletotrichum strains previously found causing anthracnoseon soybean, and other relevant strains used in taxonomic analyses were included in the phylogenetic tree. Microscope observations showed the presence of 15-µm-long cylindrical conidia and septate mycelium, and agree with those reported for the morphology of C. brevisporum by Damm et al. (2019). To confirm pathogenicity, the mycelia from a 2 day-old culture on PDA was collected and suspended in sterile ddH2O (≈ 106 cells/mL) to prepare the inoculum. The pathogen was sprayed-inoculated on stem and leaves of healthy soybean plants. In control plants, sterile ddH2O was used. Inoculated plants were maintained in growth chamber at 28 °C and 50% relative humidity. Typical anthracnose symptoms were obsered 20 days after inoculation (Figure 2). C. brevisporum was reported to produce anthracnose on pumpkin, papaya, mulberry, coffee, passion fruit and pepper in China (Liu et al. 2017; Liu et al. 2019; Xue et al. 2019). Here, we report for the first time C. brevisporum causing anthracnose on soybean, an economically-relevant crop in China.

Host range investigation of Phoma koolunga, a causal agent of ascochyta blight of field pea

Phoma koolunga is one of three species that cause ascochyta blight (synonym: blackspot) of field pea (Pisum sativum L.) in Australia. P. koolunga was first described in 2009 in South Australia and has since been reported in Western Australia and Victoria. However, the origin of the pathogen and its host range remain largely unknown. The aim of this study was to examine the host range of P. koolunga and to explore possible origin(s) of P. koolunga as a pathogen of field pea in Australia. Host range experiments were conducted in a growth room using 41 legumes comprising Australian native, naturalised, crop and pasture legumes, and wild type Pisum, Lathyrus and Vicia spp. Two isolates of P. koolunga from field pea in South Australia were compared. Disease incidence and severity were measured as number of leaves and percentage of leaf area diseased every 4 days up to 12 days post-inoculation. All legumes tested, except Cicer arietinum (chickpea), developed leaf lesions and some also had stem lesions. Disease incidence and severity differed significantly among species but not consistently between the P. koolunga isolates. The ability of the isolates to cause lesions on a wide range of legumes in controlled environment conditions suggests the fungus has a broad host range in humid and mild temperature conditions conducive for disease development. These results provide no evidence to suggest P. koolunga could have evolved with any of the 17 Australian native legume species tested and the fungus is, therefore, unlikely to have originated within Australia.

A dataset of necrotized cassava root cross-section images.

Cassava brown streak disease is a major disease affecting cassava. Along with foliar chlorosis and stem lesions, a very common symptom of cassava brown streak disease is the development of a dry, brown corky rot within the starch bearing tuberous roots, also known as necrosis. This paper presents a dataset of curated image data of necrosis bearing roots across different cassava varieties. The dataset contains images of cassava root cross-sections based on trial harvests from Uganda and Tanzania. The images were taken using a smartphone camera. The resulting dataset consists of 10,052 images making this the largest publicly available dataset for crop root necrosis.The data is comprehensive and contains different variations of necrosis expression including root cross-section types, number of necrosis lesions, presentation of the necrosis lesions. The dataset is important and can be used to train machine learning models which quantify the percentage of cassava root damage caused by necrosis.

The Spectrum of Brain Stem Lesions in Children

AbstractThe objective of this study was to describe the clinicodemographic profiles, management, and outcomes of brain stem lesions in 53 pediatric patients with brain stem lesions. Most of the patients were male, 6 to 10 years of age (8.66 ± 4.69). Out of 53 patients, there were 77.36% brain stem gliomas, 11.32% tuberculomas, 5.66% abscesses, 3.77% cavernomas, and 1.89% schwannomas. With advancement in neuroimaging (e.g., tractography), intraoperative technology (e.g., ultrasound, neurophysiological monitoring, and magnetic resonance imaging), and safe and precise incision for particular lesions, majority of brain stem lesions had improved outcomes (67.92%) with significant reduction in morbidity and mortality (11.32%).

Lesion Location Predicts Risk of Aspiration in Supratentorial Ischaemic Stroke

Stroke is defined as focal or global neurological deficit of non-traumatic vascular origin which lasts 24 hours or more if the patient survives. Many researchers showed that risk of aspiration after stroke has been related to brain stem lesions. Moreover, assessing the risk of aspiration pneumonia in supratentorial ischaemic stroke has been established in a few recent studies. Aims of study was to see the association of lesion location and of risk of aspiration pneumonia in supratentorial ischaemic stroke. The study was done by random sampling from hospital-based stroke patients. Out of these patients we collected data from 100 acute hemispheric infarct patients who got admitted in Dhaka Medical College Hospital from July 2013 to December 2013. Subcortical infarcts were associated with higher proportion of risk of aspiration on day 1 with relative risk 2.63 which was statistically significant (95 percent CI 1.43 - 4.86, pvalue 0.001). Extended risk of aspiration on day 7 was also found more in these patients (relative risk 8.29, 95 percent CI 1.96 - 35.09, p-value 0.0004). Moreover, risk of aspiration was found in 32 percent patients, of which 14 percent was proved to have extended risk at day 7. Subcortical infarction is associated with higher risk of aspiration pneumonia in supratentorial ischaemic stroke. Faridpur Med. Coll. J. Jul 2019;14(2): 79-81

Prevalence of Phytophthora species in macadamia orchards in Australia and their ability to cause stem canker

AbstractIn Australia, Phytophthora cinnamomi is the only species reported as the causal agent of stem canker and root rot in macadamia. In other countries, five Phytophthora species have been reported to cause diseases in macadamia, which led us to question if more than one Phytophthora species is responsible for poor tree health in macadamia orchards in Australia. To investigate this, samples were collected from the rhizosphere, stem, and root tissues of trees with and without symptoms, nurseries, and water sources from 70 commercial macadamia orchards in Australia. Phytophthora isolates were identified based on morphological characteristics and DNA sequencing. P. cinnamomi was the most predominant and widely distributed species, and was obtained from the different types of samples including symptomless root tissues. In addition to P. cinnamomi, only P. multivora was isolated from diseased tissue (stem canker) samples. Six other Phytophthora species were obtained from the rhizosphere samples: P. pseudocryptogea, P. citrophthora, P. nicotianae, P. gondwanense, P. sojae, and a new Phytophthora taxon. Only P. cinnamomi was obtained from macadamia nursery samples, while five Phytophthora species were obtained from water sources. Of the heterothallic Phytophthora species, mating type A2 isolates were dominant in P. cinnamomi isolates, whereas only mating type A1 isolates were obtained for P. nicotianae, P. pseudocryptogea, and P. citrophthora. Pathogenicity assays revealed that P. cinnamomi and P. multivora caused significantly larger stem and leaf lesions than P. citrophthora, P. nicotianae, and P. pseudocryptogea. Phytophthora sp. and P. sojae were nonpathogenic towards leaves and stems.

Fungal lesion length and expansion rate for the root pathogen Armillaria ostoyae in Douglas‐fir affecting root colonization and damage

AbstractPlant lesions affect disease impact, progression and host resistance. Root lesions caused by Armillaria ostoyae (Romagn.) Herink were inspected on 24‐ to 34‐year‐old planted Douglas‐fir (Pseudotsuga menziesii (Mirb.) Franco) pulled from the soil in five locations. Four hundred seventy‐nine lesions were measured for length (mm), expansion rate (mm/year) and lesion type. Lesion types were patch lesions on a root side, girdled lesions covering the root circumference and root collar lesions on the stem below ground. Non‐linear mixed modelling revealed that fungal lesion length at girdled and collar lesions increased but the expansion rate slowed as a power function of time, indicating increasing secondary inoculum and host resistance. Average fungal lesion expansion rate in girdled root and collar lesions was 127 mm the first year which then declined non‐linearly to 26 mm/year after 10 years. Fungal lesion length in patch lesions showed little change after the first year of infection. For girdled and collar lesions, fungal lesion length increased with tree size at the time of infection. Sites with a longer frost‐free period had shorter girdled root and stem lesions, probably because of more active host defence. Results indicate that mortality would be rare from one infection event. Furthermore, patch lesions pose a lower risk of mortality than other lesions because of a lower fungal lesion expansion rate and secondary inoculum. Tree size, lesion position, lesion type and fungal lesion expansion rate need to be considered when assessing the risk of lesions to individual tree survival. Techniques to minimize the disease impact are discussed.

Pine Stands as Bioindicators: Justification for Air Toxicity Monitoring in an Industrial Metropolis

Five permanent sample plots (SPs; 200–250 trees per plot) were established in middle-aged high-grade suburban pine stands near the industrial city of Krasnoyarsk, Siberia, Russia. Needle damage, inventory parameters of the stands, and the defense response of the stem phloem were evaluated annually for the years 2002–2019 and attributed to acute or chronic toxic exposures (creeping fire or industrial pollutants, respectively). The results form a basis for using trees as bioindicators. A newly elaborated stem lesion test was formed from a hypothesis on the upward sugar transport for the regeneration of an injured crown, based on Eschrich’s model of bidirectional sugar transport in the phloem. The formation of a phloem lesion was induced by inoculation of the stem with a mycelial extract of the ophiostomatoid fungus Ceratocystis laricicola. The lesion length and its shift relative to the inoculation hole were measured. An increase in the length of needles at early stages of stand weakening by pollutants was found to correspond to the hormesis model (Selye’s adaptation syndrome). A possibility of assessing the chronology of pollutant toxicity and the duration of the recovery period after creeping fire was shown.

Evaluation of cardiovascular autonomic dysfunction according to heart rate turbulence and variability in patients with relapsing remitting multiple sclerosis

Background/aim Multiple sclerosis (MS) is an autoimmune disease characterized by neurodegeneration or demyelination; the relapsing–remitting phase of MS is characterized by acute exacerbation of disease activity. The most commonly used noninvasive approach to assess autonomic function is the determination of heart rate turbulence (HRT) and heart rate variability (HRV). The aim of this study was to evaluate the presence of cardiovascular autonomic dysfunction using HRT and HRV parameters determined via 24-h Holter ECG monitoring in patients with relapsing–remitting MS without known heart disease.Materials and methods The study included 26 patients diagnosed with relapsing–remitting MS and 22 age- and sex-matched healthy controls. HRT and HRV parameters were analyzed via 24-h Holter ECG monitoring. Magnetic resonance imaging findings were reevaluated to identify any demyelinating lesions in the brain stem.Results The HRV parameters of SDNNI (mean of the standard deviations of all normal sinus RR intervals in all 5-min segments), rMSSD (root–mean–square successive difference), and sNN50 (percentage of successive normal sinus RR intervals >50 ms) were significantly lower in the MS group than in the control group (P < 0.05). Conclusion This study revealed that the patients with MS had reduced HRV; this was demonstrated by dysfunction with regard to parasympathetic and sympathetic parameters in HRV analysis.

Scolytinae species damaging Carya illinoinensis trees in southern Brazil

ABSTRACT This study aims to report two species of Scolytinae that have been damaging Carya illinoinensis trees in southern Brazil. In two Brazilian municipalities, Guarapuava in Parana State and Pantano Grande in the Rio Grande do Sul State, insects of the Scolytinae family were found damaging pecan trees. Infested tree samples were kept in the laboratory in glass tubes sealed with a voile tissue until the emergence of adults. After the adults’ emergence, the specimens were identified by their morphological characteristics and sent to a taxonomist specialized in Scolytinae family for identification. The species Xyleborus retusus was identified causing damages to pecan trees from Guarapuava while the species Xyleborus ferrugineus was identified in pecan trees from Pantano Grande. Trees injured by these insects displayed similar symptoms in both study areas. In Guarapuava and Pantano Grande, 13 and 10 trees, respectively, died due to stem lesions caused by Xyleborus spp. Thus, this study reports for Brazilian pecan growers the occurrence of Scolytinae species X. retusus and X. ferrugineus damaging C. illinoiensis plants in southern Brazil. It also emphasizes the importance of constant crop monitoring to minimize the risk of pest damage.

Student Project Environmental influences on box blight epidemics

Calonectria pseudonaviculata and C. henricotiae are two recently differentiated fungal species responsible for box blight, a disease that threatens the Buxus genus. Infection can be introduced to gardens on new plants and is spread through the use of tools. The fungus survives on stem lesions and fallen leaves when spores are dispersed by rainsplash. In this study, 195 Calonectria UK isolates collected by the Royal Horticultural Society (RHS) Advisory Service were identified to species level. Detached stem assays were performed to assess how long stem and leaf lesions remain infectious, and their sensitivity to fungicides. A survey was also carried out at three National Trust properties on the effect of clipping on box blight distribution and severity. It was found that C. henricotiae was only present in and after 2011. C. henricotiae is more thermotolerant, and the increase in prevalence may be a result of increasing temperature and longer dry spells in the UK. Sporulation could occur multiple times on both stem and leaf lesions in humid conditions, although spore production dropped markedly after six sporulation events. Fungicides were effective at preventing spore production on stem lesions. Long dry spells may also reduce Calonectria’s ability to sporulate, leading to limited box blight spread between plants.

Rescue aortic balloon valvuloplasty during procedural cardiac arrest while treating critical left main stem stenosis: a case report.

BackgroundBest timing for coronary revascularization in patients with severe aortic stenosis (AS) who was a candidate for transcatheter aortic valve implantation (TAVI) is still matter of debate.Case summaryWe here report the case of an 87-year-old man with severe AS presenting with non-ST-segment elevation myocardial infarction. Coronary angiography revealed a highly complex and calcific left main stem (LMS) lesion. Rotablation-assisted percutaneous coronary intervention (PCI) was attempted but was complicated by post-stenting rapidly evolving haemodynamic impairment. A rescue ‘pacing-free’ balloon aortic valvuloplasty (BAV) was performed to rescue the patients, allowing prompt restoration of cardiac output and coronary perfusion.DiscussionAccording to guidelines and preliminary evidence, decision should be performed case by case and based on the degree of severity and complexity of either AS or coronary disease. The strategy of treating coronary lesions first may limit the risk of potential ischaemic complications during TAVI. However, the downside of it is the risk of hemodynamic crash with potential catastrophic evolution in case of PCI complications in presence of severe AS. A ‘bailout BAV’ can be considered as a salvage-strategy in case of complex and complicated LMS-PCI in the context of severe AS and advanced status of haemodynamic impairment. This approach must be seen as very last resort, while appropriate pre-procedural planning is still highly recommended in order to prevent potentially fatal procedural complications in this fragile clinical setting.