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1.
Gastric Cancer ; 26(5): 763-774, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37285071

RESUMO

BACKGROUND: In trials evaluating perioperative chemotherapy for gastric cancer, which serve as the basis for treatment guidelines, patients are selected. The generalizability of these trial findings to older patients is uncertain. METHODS: This population-based retrospective cohort study compared the survival outcomes of patients ≥ 75 years with gastric adenocarcinoma treated with or without neoadjuvant chemotherapy between 2015 and 2019. Additionally, the percentage of patients < 75 years and ≥ 75 years who did not proceeded to surgery after receiving neoadjuvant chemotherapy were examined. RESULTS: A total of 1995 patients, of whom 1249 aged < 75 years and 746 aged ≥ 75 years, were included. In the group of patients ≥ 75 years, 275 patients received neoadjuvant chemotherapy and 471 patients were directly scheduled for gastrectomy. Patients ≥ 75 years treated with or without neoadjuvant chemotherapy differed significantly from one and another in characteristics. Overall survival of patients ≥ 75 years treated with or without neoadjuvant chemotherapy was not significantly different (median 34.9 vs. 32.3 months; P = 0.506), also after adjusting for potential confounders (HR 0.87; P = 0.263). Of patients ≥ 75 years who received neoadjuvant chemotherapy, 43 (15.6%) did not proceed to surgery compared to 111 (8.9%) patients < 75 years (P < 0.001). CONCLUSION: Patients ≥ 75 years treated with or without chemotherapy were highly selected, and overall survival was not significantly different between both groups. Nonetheless, the proportion of patients who did not proceed to surgery following neoadjuvant chemotherapy was higher in patients ≥ 75 years compared to patients < 75 years. Therefore, neoadjuvant chemotherapy should be considered with more caution in patients ≥ 75 years, while identifying those who may benefit.


Assuntos
Terapia Neoadjuvante , Neoplasias Gástricas , Humanos , Idoso , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/cirurgia , Neoplasias Gástricas/patologia , Estudos de Coortes , Estudos Retrospectivos , Quimioterapia Adjuvante , Gastrectomia , Estadiamento de Neoplasias
2.
Dig Surg ; 40(1-2): 76-83, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37231877

RESUMO

INTRODUCTION: Curative therapy for gastric cancer usually consists of perioperative chemotherapy combined with a radical (R0) gastrectomy. In addition to a modified D2 lymphadenectomy, a complete omentectomy is recommended. However, there is little evidence for a survival benefit of omentectomy. This study presents the follow-up data of the OMEGA study. METHODS: This multicenter prospective cohort study included 100 consecutive patients with gastric cancer undergoing (sub)total gastrectomy with complete en bloc omentectomy and modified D2 lymphadenectomy. Primary outcome of the current study was 5-year overall survival. Patients with or without omental metastases were compared. Pathological factors associated with locoregional recurrence and/or metastases were tested with multivariable regression analysis. RESULTS: Of 100 included patients, five had metastases in the greater omentum. Five-year overall survival was 0.0% in patients with omental metastases and 44.2% in patients without omental metastases (p = 0.001). Median overall survival time for patients with or without omental metastases was 7 months and 53 months. A (y)pT3-4 stage tumor and vasoinvasive growth were associated with locoregional recurrence and/or metastases in patients without omental metastases. CONCLUSION: The presence of omental metastases in gastric cancer patients who underwent potentially curative surgery was associated with impaired overall survival. Omentectomy as part of radical gastrectomy for gastric cancer might not contribute to a survival benefit in case of undetected omental metastases.


Assuntos
Neoplasias Peritoneais , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/cirurgia , Neoplasias Gástricas/patologia , Estudos Prospectivos , Seguimentos , Recidiva Local de Neoplasia/cirurgia , Excisão de Linfonodo , Neoplasias Peritoneais/cirurgia , Neoplasias Peritoneais/secundário , Gastrectomia/métodos , Estudos Retrospectivos
3.
Ann Surg Oncol ; 28(9): 4805-4813, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33830357

RESUMO

BACKGROUND: Many hospitals postponed elective surgical care during the first wave of the coronavirus disease 2019 (COVID-19) pandemic. Some centers continued elective surgery, including esophageal cancer surgery, with the use of preoperative screening methods; however, there is no evidence supporting the safety of this strategy as postoperative outcomes after esophageal cancer surgery during the COVID-19 pandemic have not yet been investigated. METHODS: This multicenter study in four European tertiary esophageal cancer referral centers included consecutive adult patients undergoing elective esophageal cancer surgery from a prospectively maintained database in a COVID-19 pandemic cohort (1 March 2020-31 May 2020) and a control cohort (1 October 2019-29 February 2020). The primary outcome was the rate of respiratory failure requiring mechanical ventilation. RESULTS: The COVID-19 cohort consisted of 139 patients, versus 168 patients in the control cohort. There was no difference in the rate of respiratory failure requiring mechanical ventilation (13.7% vs. 8.3%, p = 0.127) and number of pulmonary complications (32.4% vs. 29.9%, p = 0.646) between the COVID-19 cohort and the control cohort. Overall, postoperative morbidity and mortality rates were comparable between both cohorts. History taking and reverse transcription polymerase chain reaction (RT-PCR) were used as preoperative screening methods to detect a possible severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in all centers. No patients were diagnosed with COVID-19 pre- or postoperatively. CONCLUSION: Esophageal cancer surgery during the first wave of the COVID-19 pandemic was not associated with an increase in pulmonary complications as no patients were diagnosed with COVID-19. Esophageal cancer surgery can be performed safely with the use of adequate preoperative SARS-CoV-2 screening methods.


Assuntos
COVID-19 , Neoplasias Esofágicas , Adulto , Neoplasias Esofágicas/epidemiologia , Neoplasias Esofágicas/cirurgia , Humanos , Pandemias , Complicações Pós-Operatórias/epidemiologia , SARS-CoV-2
4.
BMC Emerg Med ; 21(1): 61, 2021 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-33980150

RESUMO

BACKGROUND: During the COVID-19 pandemic, a decrease in the number of patients presenting with acute appendicitis was observed. It is unclear whether this caused a shift towards more complicated cases of acute appendicitis. We compared a cohort of patients diagnosed with acute appendicitis during the 2020 COVID-19 pandemic with a 2019 control cohort. METHODS: We retrospectively included consecutive adult patients in 21 hospitals presenting with acute appendicitis in a COVID-19 pandemic cohort (March 15 - April 30, 2020) and a control cohort (March 15 - April 30, 2019). Primary outcome was the proportion of complicated appendicitis. Secondary outcomes included prehospital delay, appendicitis severity, and postoperative complication rates. RESULTS: The COVID-19 pandemic cohort comprised 607 patients vs. 642 patients in the control cohort. During the COVID-19 pandemic, a higher proportion of complicated appendicitis was seen (46.9% vs. 38.5%; p = 0.003). More patients had symptoms exceeding 24 h (61.1% vs. 56.2%, respectively, p = 0.048). After correction for prehospital delay, presentation during the first wave of the COVID-19 pandemic was still associated with a higher rate of complicated appendicitis. Patients presenting > 24 h after onset of symptoms during the COVID-19 pandemic were older (median 45 vs. 37 years; p = 0.001) and had more postoperative complications (15.3% vs. 6.7%; p = 0.002). CONCLUSIONS: Although the incidence of acute appendicitis was slightly lower during the first wave of the 2020 COVID-19 pandemic, more patients presented with a delay and with complicated appendicitis than in a corresponding period in 2019. Spontaneous resolution of mild appendicitis may have contributed to the increased proportion of patients with complicated appendicitis. Late presenting patients were older and experienced more postoperative complications compared to the control cohort.


Assuntos
Apendicite/epidemiologia , COVID-19/epidemiologia , Adulto , Apendicectomia , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Países Baixos/epidemiologia , Pandemias , Complicações Pós-Operatórias/epidemiologia , Estudos Retrospectivos , SARS-CoV-2 , Índice de Gravidade de Doença , Tempo para o Tratamento
5.
Ann Surg ; 272(6): 919-924, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33021367

RESUMO

OBJECTIVE: To determine the yield of preoperative screening for COVID-19 with chest CT and RT-PCR in patients without COVID-19 symptoms. SUMMARY OF BACKGROUND DATA: Many centers are currently screening surgical patients for COVID-19 using either chest CT, RT-PCR or both, due to the risk for worsened surgical outcomes and nosocomial spread. The optimal design and yield of such a strategy are currently unknown. METHODS: This multicenter study included consecutive adult patients without COVID-19 symptoms who underwent preoperative screening using chest CT and RT-PCR before elective or emergency surgery under general anesthesia. RESULTS: A total of 2093 patients without COVID-19 symptoms were included in 14 participating centers; 1224 were screened by CT and RT-PCR and 869 by chest CT only. The positive yield of screening using a combination of chest CT and RT-PCR was 1.5% [95% confidence interval (CI): 0.8-2.1]. Individual yields were 0.7% (95% CI: 0.2-1.1) for chest CT and 1.1% (95% CI: 0.6-1.7) for RT-PCR; the incremental yield of chest CT was 0.4%. In relation to COVID-19 community prevalence, up to ∼6% positive RT-PCR was found for a daily hospital admission rate >1.5 per 100,000 inhabitants, and around 1.0% for lower prevalence. CONCLUSIONS: One in every 100 patients without COVID-19 symptoms tested positive for SARS-CoV-2 with RT-PCR; this yield increased in conjunction with community prevalence. The added value of chest CT was limited. Preoperative screening allowed us to take adequate precautions for SARS-CoV-2 positive patients in a surgical population, whereas negative patients needed only routine procedures.


Assuntos
Infecções Assintomáticas , COVID-19/diagnóstico , Tratamento de Emergência , Programas de Rastreamento/estatística & dados numéricos , Cuidados Pré-Operatórios/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , SARS-CoV-2 , Procedimentos Cirúrgicos Operatórios , Tórax/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Procedimentos Cirúrgicos Eletivos , Humanos , Estudos Retrospectivos
7.
Plant Dis ; 100(3): 617-624, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30688594

RESUMO

Puccinia psidii (Myrtle rust) is an emerging pathogen that has a wide host range in the Myrtaceae family; it continues to show an increase in geographic range and is considered to be a significant threat to Myrtaceae plants worldwide. In this study, we describe the development and validation of three novel real-time polymerase reaction (qPCR) assays using ribosomal DNA and ß-tubulin gene sequences to detect P. psidii. All qPCR assays were able to detect P. psidii DNA extracted from urediniospores and from infected plants, including asymptomatic leaf tissues. Depending on the gene target, qPCR was able to detect down to 0.011 pg of P. psidii DNA. The most optimum qPCR assay was shown to be highly specific, repeatable, and reproducible following testing using different qPCR reagents and real-time PCR platforms in different laboratories. In addition, a duplex qPCR assay was developed to allow coamplification of the cytochrome oxidase gene from host plants for use as an internal PCR control. The most optimum qPCR assay proved to be faster and more sensitive than the previously published nested PCR assay and will be particularly useful for high-throughput testing and to detect P. psidii at the early stages of infection, before the development of sporulating rust pustules.

8.
J Cancer Res Clin Oncol ; 149(13): 11105-11115, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37344606

RESUMO

INTRODUCTION: Diffuse-type gastric cancer (DTGC) is associated with poor outcome. Surgical resection margin status (R) is an important prognostic factor, but its exact impact on DTGC patients remains unknown. The aim of this study was to assess the prognostic value of microscopically positive margins (R1) after gastrectomy on survival and tumour recurrence in DTGC patients. METHODS: All consecutive DTGC patients from two tertiary centers who underwent curative oncologic gastrectomy from 2005 to 2018 were analyzed. The primary endpoint was overall survival (OS) for R0 versus R1 patients. Secondary endpoints included disease-free survival (DFS), recurrence patterns as well as the overall survival benefit of chemotherapy in this DTGC patient cohort. RESULTS: Overall, 108 patients were analysed, 88 with R0 and 20 with R1 resection. Patients with negative lymph nodes and negative margins (pN0R0) had the best OS (median 102 months, 95% CI 1-207), whereas pN + R0 patients had better median OS than pN + R1 patients (36 months 95% CI 13-59, versus 7 months, 95% CI 1-13, p < 0.001). Similar findings were observed for DFS. Perioperative chemotherapy offered a median OS of 46 months (95% CI 24-68) versus 9 months (95% CI 1-25) after upfront surgery (p = 0.022). R1 patients presented more often early recurrence (< 12 postoperative months, 30% vs 8%, p = 0.002), however, no differences were observed in recurrence location. CONCLUSION: DTGC patients with microscopically positive margins (R1) presented poorer OS and DFS, and early tumour recurrence in the present series. R0 resection should be obtained whenever possible, even if other adverse biological features are present.


Assuntos
Neoplasias Gástricas , Humanos , Neoplasias Gástricas/cirurgia , Recidiva Local de Neoplasia/patologia , Margens de Excisão , Estudos Retrospectivos , Prognóstico , Gastrectomia , Taxa de Sobrevida
9.
Phytopathology ; 102(11): 1034-44, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22877312

RESUMO

ABSTRACT Pseudomonas syringae pv. actinidiae, the causal agent of canker in kiwifruit (Actinidia spp.) vines, was first detected in Japan in 1984, followed by detections in Korea and Italy in the early 1990s. Isolates causing more severe disease symptoms have recently been detected in several countries with a wide global distribution, including Italy, New Zealand, and China. In order to characterize P. syringae pv. actinidiae populations globally, a representative set of 40 isolates from New Zealand, Italy, Japan, South Korea, Australia, and Chile were selected for extensive genetic analysis. Multilocus sequence analysis (MLSA) of housekeeping, type III effector and phytotoxin genes was used to elucidate the phylogenetic relationships between P. syringae pv. actinidiae isolates worldwide. Four additional isolates, including one from China, for which shotgun sequence of the whole genome was available, were included in phylogenetic analyses. It is shown that at least four P. syringae pv. actinidiae MLSA groups are present globally, and that marker sets with differing evolutionary trajectories (conserved housekeeping and rapidly evolving effector genes) readily differentiate all four groups. The MLSA group designated here as Psa3 is the strain causing secondary symptoms such as formation of cankers, production of exudates, and cane and shoot dieback on some kiwifruit orchards in Italy and New Zealand. It is shown that isolates from Chile also belong to this MLSA group. MLSA group Psa4, detected in isolates collected in New Zealand and Australia, has not been previously described. P. syringae pv. actinidiae has an extensive global distribution yet the isolates causing widespread losses to the kiwifruit industry can all be traced to a single MLSA group, Psa3.


Assuntos
Actinidia/microbiologia , Doenças das Plantas/microbiologia , Pseudomonas syringae/genética , Ásia , Australásia , DNA Bacteriano/química , DNA Bacteriano/genética , Europa (Continente) , Evolução Molecular , Frutas/microbiologia , Genes Bacterianos/genética , Família Multigênica , Tipagem de Sequências Multilocus , Filogenia , Pseudomonas syringae/classificação , Pseudomonas syringae/isolamento & purificação , América do Sul
10.
Eur J Surg Oncol ; 48(2): 362-369, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34384656

RESUMO

BACKGROUND: Most studies exploring the role of staging laparoscopy in gastric cancer are limited by low sample size and are predominantly conducted in Asian countries. This study sets out to determine the value of staging laparoscopy in patients with advanced gastric cancer in a Western population. METHODS: All patients with gastric cancer from a tertiary referral center without definite evidence of non-curable disease after initial staging, and who underwent staging laparoscopy between 2013 and 2020, were identified from a prospectively maintained database. The proportion of patients in whom metastases or locoregional non-resectability was detected during staging laparoscopy was established. Secondary outcomes included the avoidable surgery rate (detection of non-curable disease during gastrectomy with curative intent) and diagnostic accuracy (sensitivity, specificity, accuracy, negative and positive predictive value). RESULTS: A total of 216 patients were included. Staging laparoscopy revealed metastatic disease in 46 (21.3 %) patients and a non-resectable tumor in three (1.4 %) patients. During intended gastrectomy, non-curable disease was revealed in 13 (8.6 %) patients. Overall sensitivity, specificity and diagnostic accuracy were 76.6 %, 100 % and 92.6 %, respectively. The positive predictive value was 100 % and the negative predictive value was 90.3 %. CONCLUSION: Staging laparoscopy is valuable in the staging process of gastric cancer with a high accuracy in detecting non-curable disease, thereby preventing futile treatment and its associated burden.


Assuntos
Adenocarcinoma/patologia , Laparoscopia/métodos , Neoplasias Hepáticas/diagnóstico , Estadiamento de Neoplasias/métodos , Neoplasias Peritoneais/diagnóstico , Neoplasias Gástricas/patologia , Adenocarcinoma/diagnóstico , Adenocarcinoma/secundário , Adenocarcinoma/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Ascite/diagnóstico , Estudos de Coortes , Feminino , Gastrectomia , Humanos , Neoplasias Hepáticas/secundário , Masculino , Pessoa de Meia-Idade , Lavagem Peritoneal , Neoplasias Peritoneais/secundário , Neoplasias Gástricas/diagnóstico , Neoplasias Gástricas/cirurgia , Adulto Jovem
11.
Front Microbiol ; 12: 739995, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34552577

RESUMO

There is a real and urgent need for new antibiotics able to kill Mycobacteria, acid-fast bacilli capable of causing multiple deadly diseases. These include members of the Mycobacterium tuberculosis complex, which causes the lung disease tuberculosis (TB) as well as non-tuberculous Mycobacteria (NTM) a growing cause of lung, skin, soft tissue, and other infections. Here we describe a medium-throughput bioluminescence-based pipeline to screen fungi for activity against Mycobacteria using the NTM species Mycobacterium abscessus and Mycobacterium marinum. We used this pipeline to screen 36 diverse fungal isolates from the International Collection of Microorganisms from Plants (ICMP) grown on a wide variety of nutrient-rich and nutrient-poor media and discovered that almost all the tested isolates produced considerable anti-mycobacterial activity. Our data also provides strong statistical evidence for the impact of growth media on antibacterial activity. Chemical extraction and fractionation of a subset of the ICMP isolates revealed that much of the activity we observed may be due to the production of the known anti-mycobacterial compound linoleic acid. However, we have identified several ICMP isolates that retained their anti-mycobacterial activity in non-linoleic acid containing fractions. These include isolates of Lophodermium culmigenum, Pseudaegerita viridis, and Trametes coccinea, as well as an unknown species of Boeremia and an isolate of an unknown genus and species in the family Phanerochaetaceae. Investigations are ongoing to identify the sources of their anti-mycobacterial activity and to determine whether any may be due to the production of novel bioactive compounds.

12.
Clin Transl Sci ; 14(3): 847-858, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33278334

RESUMO

Positron emission tomography (PET) using 2-deoxy-2-[18 F]fluoro-d-glucose ([18 F]FDG), a marker of energy metabolism and cell proliferation, is routinely used in the clinic to assess patient response to chemotherapy and to monitor tumor growth. Treatment with some tyrosine kinase inhibitors (TKIs) causes changes in blood glucose levels in both nondiabetic and diabetic patients. We evaluated the interaction of several classes of TKIs with human glucose transporter-1 (hGLUT-1) in FaDu and GIST-1 cells by measuring [3 H]2-deoxy-d-glucose ([3 H]2-DG) and [3 H]FDG uptake. Uptake of both was inhibited to varying extents by the TKIs, and representative TKIs from each class showed competitive inhibition of [3 H]2-DG uptake. In GIST-1 cells, [3 H]FDG uptake inhibition by temsirolimus and nilotinib was irreversible, whereas inhibition by imatinib, gefitinib, and pazopanib was reversible. Molecular modeling studies showed that TKIs form multiple hydrogen bonds with polar residues of the sugar binding site (i.e., Q161, Q282, Q283, N288, N317, and W388), and van der Waals interactions with the H-pocket site. Our results showed interaction of TKIs with amino acid residues at the glucose binding site to inhibit glucose uptake by hGLUT-1. We hypothesize that inhibition of hGLUT-1 by TKIs could alter glucose levels in patients treated with TKIs, leading to hypoglycemia and fatigue, although further studies are required to evaluate roles of other SLC2 and SLC5 members. In addition, TKIs could affect tumor [18 F]FDG uptake, increasingly used as a marker of tumor response. The hGLUT-1 inhibition by TKIs may have implications for routine [18 F]FDG-PET monitoring of tumor response in patients.


Assuntos
Fluordesoxiglucose F18/farmacologia , Transportador de Glucose Tipo 1/metabolismo , Glucose/metabolismo , Tomografia por Emissão de Pósitrons/métodos , Inibidores de Proteínas Quinases/farmacologia , Sítios de Ligação , Linhagem Celular Tumoral , Interações Medicamentosas , Transportador de Glucose Tipo 1/ultraestrutura , Humanos , Simulação de Acoplamento Molecular , Ligação Proteica
13.
Eur J Surg Oncol ; 47(6): 1441-1448, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33234483

RESUMO

BACKGROUND: Studies on the value of a staging laparoscopy in detecting metastases in gastric cancer patients show great variation. This study investigates the avoidable surgery rate in patients with and without a staging laparoscopy scheduled for surgery with curative intent. METHODS: This population-based cohort study included all patients with an intentional resection for a potentially curable gastric adenocarcinoma, between 2011 and 2016, registered in the Dutch Upper GI Cancer audit. Patients with and without a staging laparoscopy were compared. The primary outcome was the avoidable surgery rate (detection of metastases and/or locoregional non-resectable tumor during intentional gastrectomy). Secondary outcomes were the negative predictive value, postoperative morbidity and pathology parameters. RESULTS: 2849 patients who underwent an intentional gastrectomy were included. 414 of 2849 (14.5%) patients underwent a staging laparoscopy before initiation of treatment. The avoidable surgery rate was 16.2% in the staging laparoscopy group, compared to 8.5% in the non-staging group (P < 0.001), resulting in a negative predictive value of 83.8%. The avoidable surgery rate remained significantly different after correction for possible confounders. The main reason for not executing the gastrectomy was the presence of distant metastasis in both groups. cT and cN stage were significantly higher in patients who underwent a staging laparoscopy. CONCLUSIONS: The staging laparoscopy group had a higher cTN and pTN stage, implicating selection of patients with more advanced disease for a staging laparoscopy. Despite the staging laparoscopy, a higher rate of avoidable surgery was found, suggesting a low sensitivity for detecting metastases or locoregional non-resectability in this patient group.


Assuntos
Adenocarcinoma/secundário , Adenocarcinoma/cirurgia , Gastrectomia/estatística & dados numéricos , Estadiamento de Neoplasias , Neoplasias Gástricas/patologia , Neoplasias Gástricas/cirurgia , Procedimentos Desnecessários/estatística & dados numéricos , Contraindicações de Procedimentos , Técnicas de Diagnóstico por Cirurgia , Feminino , Gastrectomia/efeitos adversos , Humanos , Laparoscopia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Retrospectivos , Fatores de Risco
14.
Plant Dis ; 94(6): 781, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30754319

RESUMO

In December 2008 (austral summer), a new disease of Dracaena reflexa Lam. cv. Anita was observed in a postentry quarantine greenhouse near Auckland, New Zealand on plants imported from Costa Rica. Symptoms included rust-colored, water-soaked lesions with chlorotic margins approximately 5 by 10 mm. When the disease was first noticed, incidence approached 80%, but subsequent reduction in greenhouse temperature dramatically reduced symptom expression and lesions were only visible on some leaf tips. Bacteria consistently isolated from the lesions on King's medium B (KB) were cream-colored, shiny, and produced a yellow, diffusible, nonfluorescent pigment. All isolates were able to rot onion slices. On the basis of BIOLOG (Hayward, CA) carbon utilization profiles, isolates were initially identified as Burkholderia gladioli (Severini 1913) Yabuuchi et al. 1993 with a probability index of 100% and a similarity index of 0.85. For molecular identification, a near full-length sequence of the 16S rDNA gene was amplified from all isolates using primers fD2 and rP1 (1), obtaining a PCR product of approximately 1,500 bp. The nucleotide sequences were 100% identical to a number of B. gladioli GenBank entries, including Accession Nos. EF193645 and EF088209. To confirm pathogenicity, three isolates (two isolated prior to greenhouse temperature reduction and one after) were used. Three D. reflexa plants were inoculated per bacterial isolate by wounding three young fully expanded leaves on each plant (four wounds per leaf) and spraying the leaves with a bacterial suspension in sterile distilled water at 108 CFU/ml. At the same time, Gladiolus nanus plants were inoculated in a similar manner. Control plants (D. reflexa and G. nanus) were wounded and sprayed with sterile distilled water. All inoculated plants were covered with plastic bags to maintain humidity and placed in a growth chamber at 25°C. At 3 days, all inoculated plants began to show water soaking and reddish coloration around the inoculation sites, and by 7 days, the lesions had expanded to resemble natural infection. Bacteria isolated on KB from the leading edge of each lesion were morphologically identical to the initial isolates. No bacteria were recovered from the wound sites on the control plants. The 16S rDNA sequences of selected isolates from inoculated plants showed 100% identity to the sequences of the initial isolates, thereby fulfilling Koch's postulates. To our knowledge, this is the first report of B. gladioli causing leaf spot of D. reflexa in the world. Reference: (1) W. G. Weisburg et al. J. Bacteriol. 173:697, 1991.

15.
Biomacromolecules ; 10(12): 3215-26, 2009 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-19883046

RESUMO

Block copolymers poly(trimethylsilyl propargyl methacrylate)-block-poly(poly(ethylene glycol) methyl ether methacrylate) (P(TMS-PAMA)-b-P(PEGMA)) were synthesized using reversible addition-fragmentation chain transfer (RAFT) polymerization. Subsequent removal of the trimethylsilyl protective groups on the P(TMS-PAMA)(24)-b-P(PEGMA)(40) polymer with tetra-n-butylammonium fluoride hydrate lead to the polymer P(PAMA)(24)-b-P(PEGMA)(40) with pendant alkyne groups, which self-assembled in aqueous solution into micelles with hydrodynamic diameters of less than 20 nm. The alkyne groups in the core took on two functions, acting as a ligand for Co(2)(CO)(8) to generate a derivative of the antitumor agents based on (alkyne)Co(2)(CO)(6) as well as an anchor point for the cross-linking of micelles via click chemistry. The click process was shown to be highly efficient with the two types of cross-linker employed: 1,2-bis-(2-azidoethoxy)ethane and bis-(azidoethyl)disulfide, with almost all of the cross-linker reacting with the micelle at room temperature. The cross-linking density was influenced by the amount of added cross-linker leaving a well-defined amount of alkyne groups that were utilized in the formation of the cobalt complexes. The successful complexation was confirmed via UV/vis and FT-IR spectroscopy. With the formation of (alkyne)Co(2)(CO)(6) moieties in the core, the un-cross-linked and cross-linked micelles were found to almost double in size. The resulting Co-loaded un-cross-linked micelles were observed to be highly toxic to L929 fibroblast cells, while the cross-linking of the micelle was shown to reduce the toxicity.


Assuntos
Antineoplásicos/administração & dosagem , Cobalto/administração & dosagem , Portadores de Fármacos , Micelas , Nanopartículas/química , Ácidos Polimetacrílicos/química , Animais , Antineoplásicos/química , Linhagem Celular Tumoral , Cobalto/química , Fibroblastos/efeitos dos fármacos , Camundongos
16.
Plant Dis ; 93(4): 430, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30764231

RESUMO

In August of 2005, seeds of wheat (Triticum aestivum) breeding line 6065.3 tested positive for Wheat streak mosaic virus (WSMV; genus Tritimovirus) by a WSMV-specific reverse transcription (RT)-PCR assay (2). The sequence of the 200-bp amplicon (GenBank Accession No. FJ434246) was 99% identical with WSMV isolates from Turkey and the United States (GenBank Accession Nos. AF454455 and AF057533) and 96 to 97% identical to isolates from Australia (GenBank Accession Nos. DQ888801 to DQ888805 and DQ462279), which belong to the subclade D (1). As a result, an extensive survey of three cereal experimental trials and 105 commercial wheat crops grown on the South Island of New Zealand was conducted during the 2005-2006 summer to determine the distribution of WSMV. Wherever possible, only symptomatic plants were collected. Symptoms on wheat leaf samples ranged from very mild mosaic to symptomless. In total, 591 leaf samples suspected to be symptomatic were tested for WSMV by a double-antibody sandwich (DAS)-ELISA (DSMZ, Braunschweig, Germany). Of the 591 symptomatic samples, 81 tested positive. ELISA results were confirmed by RT-PCR with novel forward (WSMV-F1; 5'-TTGAGGATTTGGAGGAAGGT-3') and reverse (WSMV-R1; 5'-GGATGTTGCCGAGTTGATTT-3') primers designed to amplify a 391-nt fragment encoding a region of the P3 and CI proteins. Total RNA was extracted from the 81 ELISA-positive leaf samples using the Plant RNeasy Kit (Qiagen Inc., Chatsworth, CA). The expected size fragment was amplified from each of the 81 ELISA-positive samples. The positive samples represent 30 of 56 wheat cultivars (54%) collected from 28 of 108 sites (26%) sampled in the growing regions from mid-Canterbury to North Otago. These results suggest that WSMV is widespread in New Zealand both geographically and within cultivars. WSMV is transmitted by the wheat curl mite (Aceria tosichella) (3), which had not been detected in New Zealand despite repeated and targeted surveys. WSMV is of great economic importance in some countries, where the disease has been reported to cause total yield loss (3). Although WSMV is transmitted by seeds at low rates (0.1 to 0.2%) (4), it is the most likely explanation of the spread of the disease in New Zealand. References: (1) G. I. Dwyer et al. Plant Dis. 91:164, 2007. (2) R. French and N. L. Robertson. J. Virol. Methods 49:93, 1994. (3) R. French and D. C. Stenger. Descriptions of Plant Viruses. Online publication. No. 393, 2002. (4) R. A. C. Jones et al. Plant Dis. 89:1048, 2005.

17.
Plant Dis ; 92(3): 486, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30769711

RESUMO

Passiflora latent virus (PLV) naturally infects cultivated and wild Passiflora species in Australia, Germany, Israel and the United States (1-3). In March 2004, chlorotic lesions were observed on leaves of three vines of Passiflora tarminiana on one site in Auckland, New Zealand. Chenopodium amaranticolor and C. quinoa inoculated with sap from symptomatic leaves developed chlorotic local spots, followed by systemic leaf chlorosis and necrosis. Local symptoms appeared more quickly on C. quinoa (12 days) than on C. amaranticolor (20 days). No symptoms were observed on inoculated plants of Nicotiana benthamiana, N. clevelandii, N. occidentalis, N. tabacum, or Phaseolus vulgaris. Electron microscopy of crude sap preparations from infected C. quinoa, C. amaranticolor, N. occidentalis, and P. tarminiana showed flexuous, filamentous virus particles approximately 650 nm long. Plants of P. tarminiana and the three inoculated indicator species containing virus particles tested positive by PLV polyclonal antiserum in double-antibody sandwich (DAS)-ELISA (DSMZ, Braunschweig, Germany) and immunosorbent electron microscopy (Stephan Winter, DSMZ, personal communication). Nucleic acid was extracted from leaves of plants of each of the four viruliferous species with an RNeasy Plant Mini Kit (Qiagen, Doncaster, Australia) and then used in reverse transcription (RT)-PCR tests with novel forward (5'-CGAGACACACGCAAACGAA-3') and reverse (5'-CAGCAAAGCAAAGACACGA-3') primers specific to a 523-bp fragment of the PLV polyprotein. PCR products of the expected size were obtained, and an amplicon from P. tarminiana was directly sequenced (GenBank Accession No. EU257510). A BLAST search in GenBank showed 94% nucleotide sequence identity with a PLV isolate from Israel (GenBank Accession No. DQ455582). To our knowledge, this is the first finding of PLV in P. tarminiana and the first report of the virus in New Zealand. Chenopodium spp. have been reported previously as experimental hosts (2,3), and this study revealed that N. occidentalis also can be infected latently with PLV. P. tarminiana is a weed in New Zealand and subject to active control measures to manage the species. Economically important species such as P. edulis and P. ligularis are potentially susceptible to the virus. These species are not grown commercially in the surrounding area but are common in domestic Auckland gardens. Infected vines were removed from the site and destroyed, and symptomatic vines have not been observed at other sites. References: (1) R. D. Pares et al. Plant Dis. 81:348, 1997. (2) S. Spiegel et al. Arch. Virol. 152:181, 2007. (3) A. A. Stihll et al. Plant Dis. 76:843, 1992.

18.
Plant Dis ; 92(9): 1367, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30769434

RESUMO

Hibiscus spp. are popular ornamental plants in New Zealand. The genus is susceptible to Hibiscus chlorotic ringspot virus (HCRSV), a member of the genus Carmovirus, which has been reported in Australia, El Salvador, Singapore, the South Pacific Islands, Taiwan, Thailand, and the United States (1-4). In May of 2004, chlorotic spotting and ringspots were observed on the leaves of two H. rosa-sinensis plants in a home garden in Auckland, New Zealand. When inoculated with sap from symptomatic leaves, Chenopodium quinoa and C. amaranticolor developed faint chlorotic local lesions 12 to 15 days later. Phaseolus vulgaris exhibited small necrotic local spots 10 days postinoculation. No symptoms were observed on inoculated plants of Cucumis sativus, Gomphrena globosa, Nicotiana Clevelandii, N. tabacum, or N. sylvestris. Plants of H. rosa-sinensis and the three symptomatic indicator species tested positive for HCRSV using polyclonal antiserum (Agdia Inc., Elkhart, IN) in a double antibody sandwich (DAS)-ELISA. Forward (5'-GGAACCCGTCCTGTTACTTC-3') and reverse (5'-ATCACATCCACATCCCCTTC-3') primers were designed on the basis of a conserved region in the coat protein gene (nt 2722-3278) of HCRSV isolates in GenBank (Accession Nos. X86448 and DQ392986). A product of the expected size (557 bp) was amplified by reverse transcription (RT)-PCR with total RNA extracted from the four infected species. Comparison of the sequence of the amplicon from H. rosa-sinensis (GenBank Accession No. EU554660) with HCRSV isolates from Singapore and Taiwan (GenBank Accession Nos. X86448 and DQ392986) showed 99 and 94% nucleotide identity, respectively. From 2006 to 2008, samples from a further 25 symptomatic hibiscus plants were collected from different locations in the Auckland region. Nineteen, including plants of H. diversifolius, H. rosa-sinensis, and H. syriacus, tested positive for HCRSV by RT-PCR. To our knowledge, this is the first report of HCRSV in New Zealand and of the virus in H. diversifolius and H. syriacus. HCRSV is considered to be widespread in New Zealand. References: (1) A. A. Brunt et al. Plant Pathol. 49:798, 2000. (2) S. C. Li et al. Plant Pathol. 51:803, 2002. (3) H. Waterworth. No.227 in: Descriptions of Plant Viruses. CMI/AAB, Surrey, UK, 1980. (4) S. M. Wong et al. Acta Hortic. 432:76, 1996.

19.
Plant Dis ; 91(12): 1682, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30780622

RESUMO

Apium virus Y (ApVY) has been detected for the first time in New Zealand. In January 2006, leaf mosaic and vein-banding symptoms were observed on cultivated celery (Apium graveolens cv. Tongo) in Wanganui, New Zealand. Symptoms were widespread and seen in several paddocks. Similar symptoms were also observed in poison hemlock (Conium maculatum), a weed commonly found growing along the edges of the crop. Chenopodium amaranticolor and C. quinoa plants inoculated with leaf sap from a single, symptomatic celery or hemlock plant developed necrotic local spots after 9 and 12 days, respectively. Six Nicotiana spp. did not develop symptoms and were not tested further. Electron microscopy of sap from the celery, hemlock, and C. quinoa plants revealed the presence of elongated flexuous virus particles, 650 to 850 nm long. Symptomatic plants of these three species were tested for ApVY by reverse transcription (RT)-PCR using novel forward (5'-ATGATGCGTGGTTTGAAGG-3') and reverse (5'-CTTGGTGCGTGAGTTCTTG-3') primers specific to the coat protein gene (GenBank Accession No. AF203529). Amplicons of the expected size (approximately 425 bp) were obtained from all samples, and an amplicon from celery was sequenced (GenBank Accession No. EU127499). Comparison with ApVY sequences in GenBank confirmed the identity of the product, which had 97 to 99% nucleotide identity with GenBank Accession Nos. AF 203529, AF207594, and AY049716. The effect of ApVY on celery is unknown. ApVY has recently been described and infects three species of Apiaceae in Australia (2). In this study, diseased celery, but not the hemlock plants, were found to be coinfected with Celery mosaic virus (CeMV) by enzyme-linked immunsorbent assays with CeMV-specific antibodies (Loewe Biochemica GmbH, Sauerlach, Germany). Therefore, the symptoms observed in celery may be induced by ApVY or CeMV. CeMV is a serious disease of celery in New Zealand (1) and CeMV symptoms may mask the presence of ApVY. References: (1) P. R. Fry and C. H. Procter. N. Z. Commer. Grower 24:23, 1968. (2) J. Moran et al. Arch. Virol. 147:1855, 2002.

20.
Plant Dis ; 91(1): 110, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30781078

RESUMO

Euphorbia pulcherrima (poinsettias) are commonly infected with Poinsettia mosaic virus (PnMV), which resembles the Tymovirus genus in its morphology and viral properties (2) but is closer to the Marafivirus genus at the sequence level (1). Symptoms induced by PnMV range from leaf mottling and bract distortion to symptomless (2). The presence of PnMV in plants imported into New Zealand had never been proven. Leaves of 10 E. pulcherrima samples and six samples from other Euphorbia spp. (E. atropurpurea, E. lambii, E. leuconeura, E. mellifera, E. milii, and E. piscatorial) were collected in the Auckland area, North Island in 2002. Isometric particles of 26 to 30 nm in diameter were observed with electron microscopy in 3 of 10 E. pulcherrima samples. These three samples produced systemic chlorosis and crinkling symptoms on mechanically inoculated Nicotiana benthamiana, which tested PnMV positive by double-antibody sandwich (DAS)-ELISA (Agdia, Elkart, IN). No particles or symptoms on N. benthamiana were observed with the other Euphorbia spp., which were also PnMV-negative by DAS-ELISA. A reverse transcription-polymerase chain reaction (RT-PCR) was developed to further characterize PnMV. Specific primers were designed from the PnMV complete genome sequence (Genbank Accession No. AJ271595) using the Primer3 web-based software (4). Primer PnMV-F1 (5'-CCTGTATTGTCTCTTGCCGTCC-3') and primer PnMV-R1 (5'-AGAGGAAAGGAAAAGGTGGAGG-3') amplified a 764-bp product from nt 5291 of the 5'-end RNA polymerase gene to nt 6082 of the 3'-untranslated region (UTR). Total RNA was extracted from leaf samples using the Qiagen Plant RNeasy Kit (Qiagen Inc., Chastworth, CA). RT was carried out by using PnMV-R1 primer and MMLV reverse transcriptase (Promega, Madison, WI). The PCR was performed in a 20-µl volume reaction containing 2 µl cDNA, 1× Taq reaction buffer, 1.5 mM MgCl2, 0.2 mM dNTPs, 0.2 µM PnMV-F1 primer, and 1 U of Taq polymerase (Promega) with a denaturation step (94°C for 5 min), 30 amplification cycles (94°C for 30 s; 55°C for 30 s; 72°C for 1 min), and a final elongation (72°C for 5 min). The sequence of the RT-PCR product (Genbank Accession No. DQ462438) had 98.7% amino acid identity to PnMV. PCR products were obtained from two of three PnMV ELISA-positive E. pulcherrima and three of three PnMV ELISA-positive symptomatic N. benthamiana. The failure to amplify the fragment from all ELISA-positive PnMV is likely because of the presence of inhibitors and latex in E. pulcherrima (3) that make the RNA extraction difficult. Thus, while RT-PCR may be useful for further characterizing PnMV isolate sequences, ELISA may be more reliable for virus detection. In conclusion, to our knowledge, this is the first report of PnMV in E. pulcherrima but not in other Euphorbia spp. in New Zealand. E. pulcherrima plants have been imported into New Zealand for nearly 40 years, and the virus is probably widespread throughout the country via retail nursery trading. References: (1) B. G. Bradel et al. Virology 271:289, 2000. (2) R. W. Fulton and J. L. Fulton. Phytopathology 70:321, 1980. (3) D.-E. Lesemann et al. Phytopathol. Z. 107:250, 1983. (4) S. Rozen and S. Skaletsky. Page 365 in: Bioinformatics Methods and Protocols: Methods in Molecular Biology. S. Krawetz and S. Misener, eds. Humana Press, Totowa, NJ, 2000.

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