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1.
Hong Kong Med J ; 29(1): 39-48, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36810239

RESUMEN

INTRODUCTION: This study evaluated the arched bridge and vacuole signs, which constitute morphological patterns of lung sparing in coronavirus disease 2019 (COVID-19), then examined whether these signs could be used to differentiate COVID-19 pneumonia from influenza pneumonia or bacterial pneumonia. METHODS: In total, 187 patients were included: 66 patients with COVID-19 pneumonia, 50 patients with influenza pneumonia and positive computed tomography findings, and 71 patients with bacterial pneumonia and positive computed tomography findings. Images were independently reviewed by two radiologists. The incidences of the arched bridge sign and/or vacuole sign were compared among the COVID-19 pneumonia, influenza pneumonia, and bacterial pneumonia groups. RESULTS: The arched bridge sign was much more common among patients with COVID-19 pneumonia (42/66, 63.6%) than among patients with influenza pneumonia (4/50, 8.0%; P<0.001) or bacterial pneumonia (4/71, 5.6%; P<0.001). The vacuole sign was also much more common among patients with COVID-19 pneumonia (14/66, 21.2%) than among patients with influenza pneumonia (1/50, 2.0%; P=0.005) or bacterial pneumonia (1/71, 1.4%; P<0.001). The signs occurred together in 11 (16.7%) patients with COVID-19 pneumonia, but they did not occur together in patients with influenza pneumonia or bacterial pneumonia. The arched bridge and vacuole signs predicted COVID-19 pneumonia with respective specificities of 93.4% and 98.4%. CONCLUSION: The arched bridge and vacuole signs are much more common in patients with COVID-19 pneumonia and can help differentiate COVID-19 pneumonia from influenza and bacterial pneumonia.


Asunto(s)
COVID-19 , Gripe Humana , Neumonía Bacteriana , Humanos , Vacuolas , SARS-CoV-2 , Estudios Retrospectivos , Pulmón , Tomografía Computarizada por Rayos X/métodos
2.
Clin Radiol ; 75(9): 711.e13-711.e18, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32571521

RESUMEN

AIM: To evaluate whether there is an association between persistently positive plasma Epstein-Barr virus (EBV) DNA and the presence and the change in benign hyperplasia. MATERIALS AND METHODS: One hundred and seventeen participants with positive-plasma EBV-DNA, but without NPC from previous nasopharyngeal carcinoma (NPC) screening, underwent follow-up magnetic resonance imaging (MRI) and plasma EBV-DNA after 2 years. Logistic regression was used to analyse associations between MRI (benign hyperplasia on the follow-up MRI and change from 2 years earlier), and plasma EBV-DNA, smoking, and age. RESULTS: At follow-up, EBV-DNA positivity and smoking were independent parameters for the presence of benign hyperplasia (p=0.027 and 0.023 respectively). Compared with participants in whom EBV-DNA became negative (n=44/117 37.6%), those in whom EBV-DNA remained positive (n=73/117 62.4%) had a greater risk of benign hyperplasia developing (previous MRI normal), being stable or processing (52/73 71.2% versus 18/44 40.9%; p=0.001). CONCLUSION: These results suggest a potential link between benign hyperplasia on MRI and the EBV. As EBV contributes to NPC oncogenesis, future MRI research is warranted to determine if persistent benign hyperplasia is a risk marker for development of NPC.


Asunto(s)
Detección Precoz del Cáncer/métodos , Infecciones por Virus de Epstein-Barr/diagnóstico , Imagen por Resonancia Magnética/métodos , Neoplasias Nasofaríngeas/diagnóstico , Nasofaringe/patología , Adulto , Anciano , ADN Viral/análisis , Infecciones por Virus de Epstein-Barr/virología , Femenino , Herpesvirus Humano 4/genética , Humanos , Hiperplasia/diagnóstico , Masculino , Persona de Mediana Edad , Neoplasias Nasofaríngeas/virología , Nasofaringe/virología , Estudios Prospectivos
5.
Euro Surveill ; 22(13)2017 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-28382915

RESUMEN

Understanding Middle East respiratory syndrome coronavirus (MERS-CoV) transmission in dromedary camels is important, as they consitute a source of zoonotic infection to humans. To identify risk factors for MERS-CoV infection in camels bred in diverse conditions in Burkina Faso, Ethiopia and Morocco, blood samples and nasal swabs were sampled in February-March 2015. A relatively high MERS-CoV RNA rate was detected in Ethiopia (up to 15.7%; 95% confidence interval (CI): 8.2-28.0), followed by Burkina Faso (up to 12.2%; 95% CI: 7-20.4) and Morocco (up to 7.6%; 95% CI: 1.9-26.1). The RNA detection rate was higher in camels bred for milk or meat than in camels for transport (p = 0.01) as well as in younger camels (p = 0.06). High seropositivity rates (up to 100%; 95% CI: 100-100 and 99.4%; 95% CI: 95.4-99.9) were found in Morocco and Ethiopia, followed by Burkina Faso (up to 84.6%; 95% CI: 77.2-89.9). Seropositivity rates were higher in large/medium herds (≥51 camels) than small herds (p = 0.061), in camels raised for meat or milk than for transport (p = 0.01), and in nomadic or sedentary herds than in herds with a mix of these lifestyles (p < 0.005).


Asunto(s)
Camelus/virología , Infecciones por Coronavirus/veterinaria , Brotes de Enfermedades/veterinaria , Reservorios de Enfermedades/virología , Coronavirus del Síndrome Respiratorio de Oriente Medio/genética , Zoonosis/diagnóstico , Animales , Burkina Faso , Infecciones por Coronavirus/sangre , Infecciones por Coronavirus/diagnóstico , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/virología , Etiopía , Humanos , Datos de Secuencia Molecular , Marruecos , ARN Viral/análisis , Factores de Riesgo , Análisis de Secuencia de ARN , Zoonosis/epidemiología , Zoonosis/virología
6.
Hong Kong Med J ; 23(1): 54-62, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27966431

RESUMEN

INTRODUCTION: The use of adjuvant chemotherapy with S-1 (tegafur, gimeracil, and oteracil potassium) has been shown to improve the outcome of patients with gastric cancer. There are limited data on the tolerability of S-1 in Chinese patients. In this multicentre retrospective study, we assessed the toxicity profile in local patients. METHODS: Patients with stage II-IIIC gastric adenocarcinoma who had undergone curative resection and who had received S-1 adjuvant chemotherapy were included in the study. Patient demographics, tumour characteristics, chemotherapy records, as well as biochemical, haematological, and other toxicity profiles were extracted from medical charts. Potential factors associated with grade 2-4 toxicities were identified. RESULTS: Adjuvant S-1 was administered to 30 patients. Overall, 19 (63%) patients completed eight cycles. The most common grade 3-4 adverse events included neutropaenia (10%), anaemia (6.7%), septic episode (16.7%), diarrhoea (6.7%), hyperbilirubinaemia (6.7%), and syncope (6.7%). Dose reductions were made in 22 (73.3%) patients and 12 (40.0%) patients had dose delays. Univariate analyses showed that patients who underwent total gastrectomy were more likely to experience adverse haematological events (P=0.034). Patients with nodal involvement were more likely to report adverse non-haematological events (P=0.031). Patients with a history of regular alcohol intake were more likely to have earlier treatment withdrawal (P=0.044). Lower body weight (P=0.007) and lower body surface area (P=0.017) were associated with dose interruptions. CONCLUSIONS: The tolerability of adjuvant S-1 in our patient population was similar to that in other Asian patient populations. The awareness of S-1-related toxicities and increasing knowledge of potential associated factors may enable optimisation of S-1 therapy.


Asunto(s)
Adenocarcinoma/terapia , Antimetabolitos Antineoplásicos/administración & dosificación , Quimioterapia Adyuvante , Ácido Oxónico/administración & dosificación , Neoplasias Gástricas/terapia , Tegafur/administración & dosificación , Adulto , Anciano , Anciano de 80 o más Años , Anemia/etiología , Antimetabolitos Antineoplásicos/efectos adversos , Quimioterapia Adyuvante/efectos adversos , Combinación de Medicamentos , Femenino , Estudios de Seguimiento , Gastrectomía , Hong Kong , Humanos , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/tratamiento farmacológico , Neutropenia/etiología , Ácido Oxónico/efectos adversos , Estudios Retrospectivos , Factores de Riesgo , Análisis de Supervivencia , Tegafur/efectos adversos , Resultado del Tratamiento
8.
Eur J Clin Microbiol Infect Dis ; 33(1): 55-9, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24062235

RESUMEN

This study was performed to evaluate the clinical features of community-onset levofloxacin-nonsusceptible pneumococcal pneumonia and to identify risk factors for levofloxacin resistance. Using the database of a surveillance study of community-acquired pneumococcal infections in Asian countries, we conducted a nested case-control study to identify risk factors for levofloxacin-nonsusceptible S. pneumoniae in community-acquired pneumonia in adults. Of 981 patients with pneumococcal pneumonia, 46 (4.7 %) had levofloxacin-nonsusceptible S. pneumoniae, of whom 39 evaluable cases were included in the analysis. All cases were from Korea, Taiwan, and Hong Kong. Among patients with levofloxacin-susceptible S. pneumoniae, 490 controls were selected based on patient country. Of the 39 cases of levofloxacin-nonsusceptible pneumococcal pneumonia, 23 (59.0 %) were classified as healthcare-associated, while 164 (33.5 %) of the 490 controls of levofloxacin-susceptible S. pneumoniae (P = 0.001) were classified as healthcare-associated. Multivariate analysis showed that previous treatment with fluoroquinolones, cerebrovascular disease, and healthcare-associated infection were significantly associated with levofloxacin-nonsusceptible pneumococcal pneumonia (all P < 0.05). Levofloxacin-nonsusceptible pneumococci pose an important new public health threat in our region, and more information on the emergence and spread of these resistant strains will be necessary to prevent spread throughout the population.


Asunto(s)
Infecciones Comunitarias Adquiridas/epidemiología , Infecciones Comunitarias Adquiridas/microbiología , Levofloxacino/farmacología , Neumonía Neumocócica/epidemiología , Neumonía Neumocócica/microbiología , Streptococcus pneumoniae/aislamiento & purificación , Resistencia betalactámica , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Antibacterianos/farmacología , Estudios de Casos y Controles , Femenino , Hong Kong/epidemiología , Humanos , Corea (Geográfico)/epidemiología , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Factores de Riesgo , Streptococcus pneumoniae/efectos de los fármacos , Taiwán/epidemiología , Adulto Joven
9.
Infection ; 41(1): 151-7, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22821428

RESUMEN

OBJECTIVE: This study was conducted to identify risk factors for mortality and to evaluate the impact of antimicrobial resistance on outcome in adult patients with invasive pneumococcal disease (IPD). METHODS: A post hoc analysis of an observational cohort study on community-acquired pneumococcal infections was conducted and a total of 136 adult patients with IPD were analyzed in this study. RESULTS: Pneumonia was the most common type of infection (n = 84, 61.8 %), followed by primary bacteremia (n = 15, 11.0 %) and meningitis (n = 15, 11.0 %). One hundred and three patients (75.7 %) had concomitant pneumococcal bacteremia. The overall 30-day mortality rate was 26.5 % (36/136), and factors associated with 30-day mortality were corticosteroid use, presentation with septic shock, and development of acute respiratory distress syndrome (ARDS) (all P < 0.05). While penicillin and erythromycin resistance were associated with a lower mortality, an association between levofloxacin resistance and increased mortality was found in the univariate analysis; however, statistical significance was not reached (P = 0.083). Multivariable analysis showed that presentation with septic shock, corticosteroid use, development of ARDS, and levofloxacin resistance were independent factors associated with 30-day mortality. Of the five patients with IPD caused by levofloxacin-resistant Streptococcus pneumoniae, three (60 %) died within 30 days of diagnosis. CONCLUSION: Levofloxacin resistance was associated with increased mortality, along with septic shock, prior use of corticosteroids, and development of ARDS, in adult patients with IPD. Our data suggest that the emergence of levofloxacin resistance among invasive pneumococcal isolates is now becoming a challenge for clinicians managing community-acquired bacterial infections.


Asunto(s)
Antibacterianos/farmacología , Farmacorresistencia Bacteriana , Levofloxacino , Ofloxacino/farmacología , Infecciones Neumocócicas/epidemiología , Streptococcus pneumoniae/efectos de los fármacos , Adulto , Anciano , Antibacterianos/uso terapéutico , Infecciones Comunitarias Adquiridas/tratamiento farmacológico , Infecciones Comunitarias Adquiridas/epidemiología , Infecciones Comunitarias Adquiridas/mortalidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Ofloxacino/uso terapéutico , Infecciones Neumocócicas/tratamiento farmacológico , Infecciones Neumocócicas/mortalidad , Vigilancia de la Población , Estudios Prospectivos , Factores de Riesgo , Resultado del Tratamiento
10.
Lung Cancer ; 159: 18-26, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34303276

RESUMEN

INTRODUCTION: Acquired resistance to TKI is an important unmet need in the management of EGFR mutated lung cancer. Recent clinical trial IMPower150 suggested that combination approach with VEGF inhibitor, check point inhibitor immunotherapy and platinum-based chemotherapy was effective in oncogene driven lung cancer. The current trial examined the efficacy of a modified regimen in an EGFR mutated cohort. METHODS: An open-labelled, single arm, phase II study was conducted in patients with EGFR mutated NSCLC who had progressed on at least one EGFR TKI. For those with T790M mutation, radiological progression on osimertinib was required for enrolment. Patients were treated with combination atezolizumab (1200 mg), bevacizumab (7.5 mg/kg), pemetrexed (500 mg/m2) and carboplatin (AUC 5) given once every 3 weeks until progression. RESULTS: Forty patients were enrolled. Median age was 62 (range 45-76) years. More than one half (23/40, 57.5%) had progressed on osimertinib. PD-L1 expression was < 1% in 52.5%. Median follow-up time was 17.8 months. ORR was 62.5%. Median PFS was 9.4 months (95% CI: 7.6 - 12.1). One year OS was 72.5% (95% CI: 0.56-0.83). Treatment related grade 3 or above adverse events (AE) occurred in 37.5% (15/40). Immune-related AE occurred in 32.5% (13/40) patients. Quality of life measures of function and symptoms did not change significantly throughout the course of treatments. Post-trial rechallenge with EGFR TKI containing regimen resulted in PFS of 5.8 months (95% CI 3.9-10.0 months). CONCLUSION: Combination approach of atezolizumab, bevacizumab, pemetrexed and carboplatin achieved promising efficacy in metastatic EGFR mutated NSCLC after TKI failure. The results were comparable with taxane based regimen of IMPower150 while toxicity profile was improved.


Asunto(s)
Receptores ErbB , Neoplasias Pulmonares , Anciano , Anticuerpos Monoclonales Humanizados , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Bevacizumab/uso terapéutico , Carboplatino/uso terapéutico , Receptores ErbB/genética , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/genética , Persona de Mediana Edad , Mutación , Pemetrexed/uso terapéutico , Inhibidores de Proteínas Quinasas/uso terapéutico , Calidad de Vida
11.
AJNR Am J Neuroradiol ; 41(12): 2339-2344, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33122214

RESUMEN

BACKGROUND AND PURPOSE: T1ρ imaging is a new quantitative MR imaging pulse sequence with the potential to discriminate between malignant and benign tissue. In this study, we evaluated the capability of T1ρ imaging to characterize tissue by applying T1ρ imaging to malignant and benign tissue in the nasopharynx and to normal tissue in the head and neck. MATERIALS AND METHODS: Participants with undifferentiated nasopharyngeal carcinoma and benign hyperplasia of the nasopharynx prospectively underwent T1ρ imaging. T1ρ measurements obtained from the histogram analysis for nasopharyngeal carcinoma in 43 participants were compared with those for benign hyperplasia and for normal tissue (brain, muscle, and parotid glands) in 41 participants using the Mann-Whitney U test. The area under the curve of significant T1ρ measurements was calculated and compared using receiver operating characteristic analysis and the Delong test, respectively. A P < . 05 indicated statistical significance. RESULTS: There were significant differences in T1ρ measurements between nasopharyngeal carcinoma and benign hyperplasia and between nasopharyngeal carcinoma and normal tissue (all, P < . 05). Compared with benign hyperplasia, nasopharyngeal carcinoma showed a lower T1ρ mean (62.14 versus 65.45 × ms), SD (12.60 versus 17.73 × ms), and skewness (0.61 versus 0.76) (all P < .05), but no difference in kurtosis (P = . 18). The T1ρ SD showed the highest area under the curve of 0.95 compared with the T1ρ mean (area under the curve = 0.72) and T1ρ skewness (area under the curve = 0.72) for discriminating nasopharyngeal carcinoma and benign hyperplasia (all, P < .05). CONCLUSIONS: Quantitative T1ρ imaging has the potential to discriminate malignant from benign and normal tissue in the head and neck.


Asunto(s)
Imagen por Resonancia Magnética/métodos , Carcinoma Nasofaríngeo/diagnóstico por imagen , Neoplasias Nasofaríngeas/diagnóstico por imagen , Nasofaringe/diagnóstico por imagen , Nasofaringe/patología , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Cabeza/diagnóstico por imagen , Humanos , Hiperplasia/diagnóstico por imagen , Interpretación de Imagen Asistida por Computador/métodos , Masculino , Persona de Mediana Edad , Cuello/diagnóstico por imagen , Curva ROC , Estadísticas no Paramétricas
12.
AJNR Am J Neuroradiol ; 41(3): 515-521, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-32184223

RESUMEN

BACKGROUND AND PURPOSE: We evaluated modifications to our contrast-enhanced MR imaging grading system for symptomatic patients with suspected nasopharyngeal carcinoma, aimed at improving discrimination of early-stage cancer and benign hyperplasia. We evaluated a second non-contrast-enhanced MR imaging grading system for asymptomatic patients from nasopharyngeal carcinoma plasma screening programs. MATERIALS AND METHODS: Dedicated nasopharyngeal MR imaging before (plain scan system) and after intravenous contrast administration (current and modified systems) was reviewed in patients from a nasopharyngeal carcinoma-endemic region, comprising 383 patients with suspected disease without nasopharyngeal carcinoma and 383 patients with nasopharyngeal carcinoma. The modified and plain scan systems refined primary tumor criteria, added a nodal assessment, and expanded the system from 4 to 5 grades. The overall combined sensitivity and specificity of the 3 systems were compared using the extended McNemar test (a χ2 value [Formula: see text]> 5.99 indicates significance). RESULTS: The current, modified, and plain scan MR imaging systems yielded sensitivities of 99.74%, 97.91%, and 97.65%, respectively, and specificities of 63.45%, 89.56% and 86.42%, respectively. The modified system yielded significantly better performance than the current ([Formula: see text] = 122) and plain scan ([Formula: see text] = 6.1) systems. The percentages of patients with nasopharyngeal carcinoma in grades 1-2, grade 3, and grades 4-5 for the modified and plain scan MR imaging systems were 0.42% and 0.44%; 6.31% and 6.96%; and 90.36% and 87.79%, respectively. No additional cancers were detected after contrast administration in cases of a plain scan graded 1-2. CONCLUSIONS: We propose a modified MR imaging grading system that improves diagnostic performance for nasopharyngeal carcinoma detection. Contrast was not valuable for low MR imaging grades, and the plain scan shows potential for use in screening programs.


Asunto(s)
Detección Precoz del Cáncer/métodos , Interpretación de Imagen Asistida por Computador/métodos , Imagen por Resonancia Magnética/métodos , Carcinoma Nasofaríngeo/diagnóstico por imagen , Neoplasias Nasofaríngeas/diagnóstico por imagen , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Sensibilidad y Especificidad , Adulto Joven
13.
Clin Oncol (R Coll Radiol) ; 31(8): 578-588, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31178347

RESUMEN

Chinese medicine therapies in cancer treatment are very common in the East. Although it is usually classified as a form of complementary and alternative therapy in the West, Chinese medicine is an independent medical profession in Hong Kong and mainland China. It has a different perspective in understanding health and diseases compared with Western medicine. In oncology practice, whereas Western medicine focuses on direct tumour eradication by surgery, radiation therapy and systemic therapies, Chinese medicine focuses on restoring body balance and enhancing the body's defences (immunity), in addition to some cytotoxic herbal therapies. Most often patients, especially those in the East, receive both treatments. Chinese medicine is also commonly used to reduce side-effects from chemotherapy or radiation therapy, to aid recovery after an operation, to palliate symptoms and to address survivorship issues. However, this raises concerns of drug-herb interactions and toxicity in combination therapies. Commonly used Chinese medicine treatment modalities include acupuncture, moxibustion, diet therapy, prescribed Chinese medicine herbal decoction, single Chinese medicine herbs or supplements and tai chi. Although there is an increasing trend of Chinese medicine use in cancer patients in both the East and the West, the scientific evidence of safety and efficacy is often questioned by oncologists. This article reviews the current evidence in different Chinese medicine therapies in cancer management in both the East and the West.


Asunto(s)
Medicina Tradicional China/métodos , Neoplasias/tratamiento farmacológico , Neoplasias/epidemiología , Humanos
14.
Clin Oncol (R Coll Radiol) ; 31(8): 570-577, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31178345

RESUMEN

Gastric cancers are highly prevalent in both the East and the West, although they differ in aetiology and prognostic outcome. Management of gastric cancer from screening to definitive treatment varies substantially between Eastern and Western countries and regions, owing to numerous factors, including government incentives to carry out population-wide screening programmes to detect early disease, differences in clinical and biological tumour behaviours and responsiveness to treatment, patient accessibility to effective treatment, etc. This review highlights and contrasts the differences in tumour aetiology and histology, as well as the management approaches between the East and the West, which gives important insights and inspirations on future international multicentre research collaboration to combat this dreadful malignancy.


Asunto(s)
Neoplasias Gástricas , Humanos , Pronóstico , Neoplasias Gástricas/epidemiología , Neoplasias Gástricas/etiología , Neoplasias Gástricas/patología , Neoplasias Gástricas/terapia
16.
Plant Dis ; 92(11): 1588, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30764464

RESUMEN

Asiatic citrus canker caused by Xanthomonas citri pv. citri (X. citri pv. citri-A) is detrimental to citrus production in tropical and subtropical areas. The bacterium can cause severe infection on many citrus species, initially causing water-soaked leaf lesions that become erumpent and necrotic, often with a chlorotic halo. Severe infection causes premature fruit drop and twig dieback. X. citri pv. citri-A has consequently been subject to eradication and international quarantine regulations. In the 1990s, strains with a host range restricted to Mexican lime (Citrus aurantifolia), but not infecting grapefruit (C. paradisi), were described in different areas of Southwest Asia (4). This variant was designated X. citri pv. citri-A* because of its phenotypic and genetic similarities with X. citri pv. citri. Lime leaves with canker lesions were collected in 2007 from a citrus nursery in Kandal Province, Cambodia and isolations were performed with KC semiselective medium (3). Four Xanthomonas-like strains were further characterized by PCR alongside positive control strain CFBP 2525 from New Zealand. The expected DNA fragment was obtained using primer pair 4/7 (2) from the bacterial strains but not when distilled water was used as a template. Amplified fragment length polymorphism (AFLP) analysis of the four X. citri pv. citri strains from Cambodia and reference strains X. citri pv. citri-A (CFBP 2525, CFBP 2900, LMG 9322), -A* (CFBP 2911, JF90-2, JK2-10, JK143-1, JM47-2), and X. citri pv. aurantifolii (CFBP 2866, CFBP 2868, CFBP 2901) using SacI/MspI and four primer pairs (1) separated the Cambodian strains into two distinct haplotypes (i.e., AFLP fingerprint patterns). One haplotype was closely related (evolutionary genome divergences [EGD] ≤0.006 [1]) to X. citri pv. citri-A strains with a wide host range and the other was most genetically related to a strain of X. citri pv. citri-A* from Thailand (EGD of 0.003). On the basis of AFLP, the Cambodian isolates were not related to X. citri pv. aurantifolii (EGD values of >0.060). When inoculated to Mexican lime and Duncan grapefruit using a detached leaf assay in which inoculum droplets containing ∼1 × 106 CFU were deposited on wounds (4), the strains genetically related to X. citri pv. citri-A produced typical canker lesions on both citrus species a week after inoculation, whereas the Cambodian strains related to X. citri pv. citri-A* by AFLP analysis only produced canker lesions on lime. Our finding extended the geographical distribution of pathotype A*. Identification of both pathotypes from a few samples collected in a nursery suggests a potential for large-scale distribution of these strains within the citrus orchards in Cambodia, where the most important citrus crop is sweet orange, suggesting that the occurrence of X. citri pv. citri-A* is of moderate economic significance, in contrast with X. citri pv. citri-A strains with a wide host range. Diseased citrus nursery plants are a major source of primary inoculum in developing countries. Sanitation of citrus nurseries against citrus canker in Cambodia is a prerequisite for improved management of the disease. References: (1) N. Ah-You et al. Phytopathology 97:1568, 2007. (2) J. S. Hartung et al. Phytopathology 86:95, 1996. (3) O. Pruvost et al. J. Appl. Microbiol. 99:803, 2005. (4) C. Vernière et al. Eur. J. Plant Pathol. 104:477, 1998.

17.
J Hazard Mater ; 141(1): 86-91, 2007 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-16916576

RESUMEN

Chlorinated anilines are frequently used in the industry as starting materials for chemical synthesis. This type of compounds can end up as pollutants in wastewater. 2-Chloroaniline (2-ClA) was selected irradiating under monochromatic UV light at 300nm. The reaction rate could be enhanced by introducing low level of H(2)O(2) into the UV/TiO(2) system. Excess H(2)O(2) could not increase the HO* generation but retarded the reaction rate. The pH effect was also investigated in UV/TiO(2) and UV/TiO(2)/H(2)O(2) systems. All the experimental results show that pH is a sensitive parameter to the rate of degradation. Low reaction rate at acidic pH could be accounted by the dark adsorption test which has also proven the photocatalysis of TiO(2) may contribute to a two-step process: (1) 2-ClA pre-adsorbed onto TiO(2) and (2) photoexcitation of TiO(2). At high pH, rate enhancement could be observed at UV/TiO(2) system because of the increase generation of HO*. However, the introduction of H(2)O(2) slowdown the decay rate at such alkaline medium.


Asunto(s)
Compuestos de Anilina/química , Peróxido de Hidrógeno/química , Fotólisis , Titanio/química , Adsorción/efectos de la radiación , Compuestos de Anilina/efectos de la radiación , Oscuridad , Concentración de Iones de Hidrógeno , Rayos Ultravioleta , Eliminación de Residuos Líquidos/métodos
18.
Cancer Res ; 61(5): 2022-30, 2001 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-11280762

RESUMEN

Adhesion molecules are involved in intracellular signaling in various physiological and pathological processes including metastasis and growth of tumor cells. Tumor cells interact with various host cells as well as with extracellular matrices through certain adhesion molecules such as integrins. We here propose that stimulation of beta1 integrin reduces intercellular adhesion molecule (ICAM)-1-mediated interaction of lung cancer cells with CTLs. This concept is based on the following findings: (a) engagement of beta1 integrins on certain lung cancer cells by a specific antibody or by ligand matrices such as fibronectin and collagen markedly reduced ICAM-1 expression on the cell surface and induced sICAM-1; (b) down-regulation of ICAM-1 by stimulation of beta1 integrins was abrogated by tyrosine kinase inhibitors or by transfection of dominant negative truncations of focal adhesion kinase (FAK); (c) engagement of beta1 integrins also reduced ICAM-1-dependent adhesion of lung cancer cells to T cells, a process completely inhibited by tyrosine kinase inhibitors and by transfection of dominant negative forms of FAK; and (d) stimulation of beta1 integrins prevented killing of lung cancer cells by autologous CTLs. In malignant tumors, cancer cells, including lung cancer cells, are surrounded by extracellular matrix proteins such as fibronectin and collagen. This suggests that the engagement of beta1 integrins by matrix proteins potentially occurs in cancer cells in vivo and that continuous stimulation via beta1 integrins reduces ICAM-1-expression, ICAM-1-mediated adhesion of cancer cells to CTLs and their killing by CTLs. Our results suggest that such processes can lead to the escape of lung cancer cells in vivo from immunological surveillance.


Asunto(s)
Integrina beta1/fisiología , Molécula 1 de Adhesión Intercelular/biosíntesis , Neoplasias Pulmonares/patología , Proteínas Tirosina Quinasas/fisiología , Anticuerpos Monoclonales/farmacología , Adhesión Celular/fisiología , Colágeno/metabolismo , Colágeno/farmacología , Citotoxicidad Inmunológica , Regulación hacia Abajo , Fibronectinas/metabolismo , Fibronectinas/farmacología , Quinasa 1 de Adhesión Focal , Proteína-Tirosina Quinasas de Adhesión Focal , Regulación Neoplásica de la Expresión Génica , Humanos , Integrina beta1/biosíntesis , Molécula 1 de Adhesión Intercelular/genética , Molécula 1 de Adhesión Intercelular/fisiología , Neoplasias Pulmonares/metabolismo , Antígeno-1 Asociado a Función de Linfocito/fisiología , Fosforilación , Proteínas Tirosina Quinasas/metabolismo , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiología , Linfocitos T/inmunología , Linfocitos T/metabolismo , Linfocitos T/patología , Linfocitos T Citotóxicos/inmunología , Linfocitos T Citotóxicos/patología
19.
J Am Coll Cardiol ; 27(5): 1278-85, 1996 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-8609356

RESUMEN

OBJECTIVES: This study investigated whether an antibody against neutrophil adhesion protein CD18 could limit myocardial infarct size and preserve left ventricular function after prolonged reperfusion in a canine model. BACKGROUND: Myocardial reperfusion injury is mediated in part by accumulation of activated neutrophils. Although antibodies against CD18 have been shown to reduce neutrophil influx and infarct size after ischemia and 3 to 4 h of reperfusion, it is unknown whether protection is sustained beyond this time or whether there is meaningful preservation of ventricular function. METHODS: Dogs undergoing 90-min circumflex coronary artery occlusion and 48-h reperfusion were randomized to receive 1 mg/kg bodyweight of R15.7 (an anti-CD18 antibody, n = 12) or saline (control, n =12) 10 min before reperfusion. Contrast left ventriculography was used to measure left ventricular ejection fraction and regional chord shortening at baseline, during occlusion and at 48 h. Microspheres injected during occlusion were used to measure collateral flow and risk region size. Postmortem infarct size was measured with triphenyltetrazolium chloride. RESULTS: In the dose administered, R15.7 bound to neutrophils in vivo, with >85% saturation of CD18 for >24 h, with sustained antibody excess in the plasma. R15.7 significantly reduced infarct size after adjusting for the effect of collateral flow (p = 0.0002, analysis of covariance). In a subgroup of dogs with collateral flow <30% of nonischemic flow, infarct size was reduced from 34.6 +/- 3.9% (mean +/- SE) of the region at risk in the control group to 19.5 +/- 3.3% in the antibody group (p = 0.008). Ejection fraction and regional chord shortening did not differ between the two groups at baseline or during occlusion, but after 48-h reperfusion, ejection fraction and inferior wall regional cord shortening (representing the infarct zone) were both higher in the R15.7 group than the control group (43.6 +/- 2.9% vs. 28.5 +/- 1.8%, p < 0.01; 2.55 +/- 0.29% vs. 1.06 +/- 0.18%, p < 0.05). CONCLUSIONS: A single injection of an anti-CD18 antibody given before reperfusion can limit myocardial infarct size by nearly 50% and preserve global and regional left ventricular function after 48 h of reperfusion.


Asunto(s)
Anticuerpos/uso terapéutico , Antígenos CD18/inmunología , Infarto del Miocardio/tratamiento farmacológico , Isquemia Miocárdica/fisiopatología , Daño por Reperfusión/fisiopatología , Función Ventricular Izquierda/efectos de los fármacos , Animales , Anticuerpos/inmunología , Perros , Femenino , Masculino , Infarto del Miocardio/patología , Infarto del Miocardio/fisiopatología
20.
Aliment Pharmacol Ther ; 21(9): 1163-71, 2005 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-15854180

RESUMEN

BACKGROUND: Treatment with interferon-alpha has been shown to be effective in one-third of hepatitis B e antigen-positive chronic hepatitis B patients, but is clinically associated with relevant adverse events. AIM: To investigate the safety of pegylated interferon alpha-2b in 300 hepatitis B e antigen-positive patients with compensated liver disease. METHODS: Patients were treated with pegylated interferon alpha-2b for 52 weeks combined with either lamivudine 100 mg/day or placebo. Pegylated interferon alpha-2b was administered for 100 microg once a week for 32 weeks; thereafter, the dose was reduced to 50 microg once a week. Adverse events and their effect on study medication were reported at monthly visits in a standardized way. RESULTS: The most frequently reported side-effects were flu-like syndrome (68%), headache (40%), fatigue (39%), myalgia (29%) and local reaction at the injection site (29%). These symptoms typically occurred within the first month of therapy and subsided during the course of therapy. Neutropenia and thrombocytopenia induced by pegylated interferon alpha-2b increased the risk of infections and bleeding complications, but these complications were rare and mild. The frequency of all side-effects was not different between patients treated with pegylated interferon alpha-2b combined with lamivudine or placebo. In 69 (22%) patients the dose of pegylated interferon alpha-2b was reduced prematurely. Of these dose reductions, 36 (52%) were because of neutropenia. Therapy was discontinued in 28 (8%) patients. The most frequent reasons for early discontinuation were psychiatric side-effects (depression, psychosis) and flu-like symptoms. Multivariate Cox regression analysis showed that low neutrophil count at baseline and cirrhosis were independent predictors of dose reduction or therapy discontinuation. CONCLUSION: We conclude that in patients with chronic hepatitis B and compensated liver disease prolonged pegylated interferon alpha-2b therapy is safe, and that pre-existent cirrhosis and neutropenia are the most important predictors of dose reduction or early treatment discontinuation.


Asunto(s)
Antivirales/efectos adversos , Hepatitis B Crónica/tratamiento farmacológico , Interferón-alfa/efectos adversos , Adulto , Antivirales/administración & dosificación , Infecciones Bacterianas/complicaciones , Método Doble Ciego , Femenino , Hemorragia/etiología , Hepatitis B Crónica/complicaciones , Humanos , Interferón alfa-2 , Interferón-alfa/administración & dosificación , Masculino , Polietilenglicoles , Proteínas Recombinantes , Factores de Riesgo
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