RESUMO
The use of nonhost, tolerant, or resistant plants, to manage plant parasitic nematodes (PPNs), is an appealing, economic, and environmentally friendly agronomic practice, which is effective when precise information on the identification of PPN species and their virulence to target host crops is available. This chapter describes suggested protocols to evaluate the reaction of the most important crops and fruit trees to infestation by the most damaging PPN with sedentary endoparasitic habits, with the aim of assessing resistance and tolerance traits, sources of resistance in progenies from breeding programs, the reaction to nematodes of newly released cultivars, and the virulence of the most noxious PPNs. These protocols consist of classical screening techniques not involving biochemical and molecular analyses. PPN species and genera considered in this chapter include (i) the most important species of root-knot nematodes Meloidogyne spp., including also M. chitwoodi, M. enterolobii, and M. graminicola, and (ii) the cyst-forming nematodes of the genera Globodera and Heterodera, such as the potato cyst nematodes (PCNs) Globodera rostochiensis and G. pallida, and also Heterodera avenae group, H. ciceri, H. glycines, and H. schachtii. Schemes are given to identify virulence groups for most of these nematodes.
Assuntos
Melhoramento Vegetal , Tylenchoidea , Animais , Virulência , Produtos AgrícolasRESUMO
Once a nematode has been identified, to conduct studies for screening programs or pathogenicity tests, it is necessary a supply of large numbers of nematodes from field crops or reproduced and stored to be used in periods of the year when they are not available from fields. Therefore, nematodes must be reared in greenhouse or under in vitro conditions and stored for future needs. In this chapter, suggestions are given on how to obtain nematodes from fields and reproduce most of them on host plants in greenhouse (mainly Meloidogyne spp. and Globodera spp.) or in vitro. Reproductions in vitro include: On suitable callus of host plants (Pratylenchus spp., Ditylenchus spp.) On fungal cultures mainly of Botrytis cinerea or Alternaria spp. for Aphelenchoides spp. and other aphelenchids, including Bursaphelenchus xylophilus. On carrot disks for Pratylenchus spp. and Ditylenchus spp. Other specific media, such as garlic, potato, and sweet potato for D. destructor, and cocoyam disks for Radopholus similis. Guidelines are also given to store different nematodes for rather long times, including in vitro methods and in infected seeds, hay, and other plant parts. No information is given on how to prepare and store fixed materials.
Assuntos
Tylenchida , Tylenchoidea , Animais , PlantasRESUMO
The study of nematodes requires availability of nematode specimens and their population densities in plants and soil. This can be achieved using adequate sampling schemes and extraction methods. In this chapter, the most common and suitable sampling and extraction procedures and equipment are described. These include the use of Baermann's funnels, Cobb's decanting and sieving, floating methods such as the Oostenbrink method and Fenwick can, elutriators such as Seinhorst methods, centrifugation methods including that of Coolen, and mechanical and enzymatic maceration. The combination of different methods for cleaning the nematode suspensions is described, such as Cobb's sieving with Baermann's funnels or centrifugation, and for cysts combining Seinhorst's elutriator or Fenwick can with the alcohol methods. Methods for extraction of eggs and/or juveniles of cyst and egg mass forming nematodes, to be used as inoculum or to ascertain egg viability, are also described. Only little information is also noted on the use of molecular tools to identify and quantify nematode populations in soil and roots.
Assuntos
Nematoides , Tylenchida , Animais , Plantas , Solo , Raízes de Plantas/parasitologiaRESUMO
This chapter is a continuation of Chap. 3 . Initially, protocols for the screening of several host plants to their major migratory and semi-endoparasitic nematodes are presented. Then the problems related to assessment of tolerance to these nematodes are described, followed by the determination of nematode races. The main plant-nematode interactions considered are annuals and perennials to Pratylenchus spp.; banana to Radopholus similis; potato to Nacobbus aberrans; several crop plants, including onion, alfalfa, clovers, and potato, to Ditylenchus dipsaci; broad bean to D. giga; potato and sweet potato to D. destructor; peanut to D. africanus; rice to D. angustus and Aphelenchoides besseyi; wheat to Anguina tritici; different plants to Rotylenchulus reniformis; and citrus to Tylenchulus semipenetrans. Schemes to identify races or biotypes are only presented for D. dipsaci and T. semipenetrans. The occurrence of pathotypes in other nematode species is also discussed. Finally, comments are made on ectoparasitic nematodes.
Assuntos
Tylenchida , Tylenchoidea , Animais , Virulência , Plantas/parasitologiaRESUMO
OBJECTIVE: The objective of this study is to compare the effectiveness of lower limb low-load blood flow restriction training (LL-BFRT) with high-load strength training (HL-ST) as part of an outpatient pulmonary rehabilitation programme on leg strength in patients with chronic obstructive pulmonary disease (COPD). METHODS: Participants were randomised to LL-BFRT or HL-ST (24 sessions). LL-BFRT was done at 30% 1-repetition maximum (1-RM) with 70% arterial occlusion pressure. HL-ST was done at 70% 1-RM. Primary outcome was isometric strength of knee extensors and flexors. Secondary outcomes were 1-RM, functional exercise capacity, physical activity, symptom burden and health-related quality of life. Perceptions of dyspnoea and leg fatigue were recorded after every exercise. We compared groups with t-tests. RESULTS: We included 30 participants (13 women, 17 men, 64 (9) years, forced expiratory volume in 1 s 47 (18)% pred.), 24 completed the study. Isometric knee extensor strength improved to a clinically relevant degree in both legs in both groups (LL-BFRT: right leg 9 (20) Nm, left leg 10 (18) Nm; HL-ST: right leg 15 (26) Nm, left leg 16 (30) Nm, data are mean (SD)), without statistically significant or clinically relevant between-group differences (right leg mean difference= -6.4, 95% CI= -13.20 to 25.92 Nm, left leg mean difference= -5.6, 95% CI= -15.44 to 26.55 Nm). 1 min sit-to-stand test performance improved to a clinically relevant degree only in the LL-BFRT group (4 (4) vs 1 (5) repetitions). Interestingly, physical activity improved to a clinically relevant degree only in the LL-BFRT group (1506 (2441) vs -182 (1971) steps/day). LL-BFRT lowered perceived in-exercise dyspnoea and increased leg fatigue compared with HL-ST in the initial 12 trainings. CONCLUSION: In patients with stable COPD undergoing outpatient pulmonary rehabilitation, LL-BFRT was not superior to HL-ST in improving leg strength. LL-BFRT led to similar strength gains as HL-ST while reducing perceptions of dyspnoea in the initial training phase. TRIAL REGISTRATION NUMBER: NCT04151771.
Assuntos
Doença Pulmonar Obstrutiva Crônica , Treinamento Resistido , Masculino , Humanos , Feminino , Projetos Piloto , Qualidade de Vida , Terapia de Restrição de Fluxo Sanguíneo , Método Simples-Cego , Doença Pulmonar Obstrutiva Crônica/reabilitação , Dispneia/etiologia , Fadiga , Força MuscularRESUMO
We investigated how the extracellular matrix (ECM) affects LoVo colorectal cancer cells behavior during a spatiotemporal invasion. Epithelial-to-mesenchymal transition (EMT) markers, matrix-degrading enzymes, and morphological phenotypes expressed by LoVo-S (doxorubicin-sensitive) and higher aggressive LoVo-R (doxorubicin-resistant) were evaluated in cells cultured for 3 and 24 h on Millipore filters covered by Matrigel, mimicking the basement membrane, or type I Collagen reproducing a desmoplastic lamina propria. EMT and invasiveness were investigated with RT-qPCR, Western blot, and scanning electron microscopy. As time went by, most gene expressions decreased, but in type I Collagen samples, a strong reduction and high increase in MMP-2 expression in LoVo-S and -R cells occurred, respectively. These data were confirmed by the development of an epithelial morphological phenotype in LoVo-S and invading phenotypes with invadopodia in LoVo-R cells as well as by protein-level analysis. We suggest that the duration of culturing and type of substrate influence the morphological phenotype and aggressiveness of both these cell types differently. In particular, the type I collagen meshwork, consisting of large fibrils confining inter fibrillar micropores, affects the two cell types differently. It attenuates drug-sensitive LoVo-S cell aggressiveness but improves a proteolytic invasion in drug-resistant LoVo-R cells as time goes by. Experimental studies on CRC cells should examine the peri-tumoral ECM components, as well as the dynamic physical conditions of TME, which affect the behavior and aggressiveness of both drug-sensitive and drug-resistant LoVo cells differently.
RESUMO
BACKGROUND: accumulating evidence indicates that during tail regeneration in lizards the initial stage of regenerative blastema is a tumor-like proliferative outgrowth that rapidly elongates into a new tail composed of fully differentiated tissues. Both oncogenes and tumor-suppressors are expressed during regeneration, and it has been hypothesized that an efficient control of cell proliferation avoids that the blastema is turned into a tumor outgrowth. METHODS: in order to determine whether functional tumor-suppressors are present in the growing blastema we have utilized protein extracts collected from early regenerating tails of 3-5 mm that have been tested for a potential anti-tumor effect on in-vitro culture by using cancer cell lines from human mammary gland (MDA-MB-231) and prostate cancer (DU145). RESULTS: at specific dilutions, the extract determines a reduction of viability in cancer cells after 2-4 days of culture, as supported by statistical and morphological analyses. While control cells appear viable, treated cells result damaged and produce an intense cytoplasmic granulation and degeneration. CONCLUSIONS: this negative effect on cell viability and proliferation is absent using tissues from the original tail supporting the hypothesis that only regenerating tissues synthesize tumor-suppressor molecules. The study suggests that the regenerating tail of lizard at the stages here selected contains some molecules that determine inhibition of cell viability on the cancer cells analyzed.
Assuntos
Lagartos , Neoplasias , Masculino , Animais , Humanos , Lagartos/fisiologia , Regeneração/fisiologia , Diferenciação CelularRESUMO
Aim of the study was to understand the behavior of colon cancer LoVo-R cells (doxorubicin-resistant) vs. LoVo-S (doxorubicin sensitive) in the initial steps of extracellular matrix (ECM) invasion. We investigated how the matrix substrates Matrigel and type I collagen-mimicking the basement membrane (BM) and the normal or desmoplastic lamina propria, respectively-could affect the expression of epithelial-to-mesenchymal transition (EMT) markers, matrix-degrading enzymes, and phenotypes. Gene expression with RT-qPCR, E-cadherin protein expression using Western blot, and phenotypes using scanning electron microscopy (SEM) were analyzed. The type and different concentrations of matrix substrates differently affected colon cancer cells. In LoVo-S cells, the higher concentrated collagen, mimicking the desmoplastic lamina propria, strongly induced EMT, as also confirmed by the expression of Snail, metalloproteases (MMPs)-2, -9, -14 and heparanase (HPSE), as well as mesenchymal phenotypes. Stimulation in E-cadherin expression in LoVo-S groups suggests that these cells develop a hybrid EMT phenotype. Differently, LoVo-R cells did not increase their aggressiveness: no changes in EMT markers, matrix effectors, and phenotypes were evident. The low influence of ECM components in LoVo-R cells might be related to their intrinsic aggressiveness related to chemoresistance. These results improve understanding of the critical role of tumor microenvironment in colon cancer cell invasion, driving the development of new therapeutic approaches.
Assuntos
Colágeno Tipo I , Neoplasias do Colo , Transição Epitelial-Mesenquimal , Microambiente Tumoral , Humanos , Caderinas/genética , Caderinas/metabolismo , Linhagem Celular Tumoral , Movimento Celular/genética , Neoplasias do Colo/patologia , Doxorrubicina/uso terapêutico , Colágeno Tipo I/metabolismoRESUMO
Environmental concerns raised by synthetic nematicides are encouraging integrated management strategies based on their combination with non-chemical control tools, such as biocontrol agents and/or organic amendments. In this study, the combination of the fumigant 1,3-dichloropropene (1,3-D) with a commercial formulation of the biocontrol agent Trichoderma harzianum (TH) and an organic fertilizer (OF) was investigated in two consecutive tomato crops for its effect on the root-knot nematode Meloidogyne incognita and plant growth and yield. The application of 1,3-D was only performed on the first crop, while TH and OF were provided to both crops. Almost all treatments significantly reduced nematode infestation in both crops, though the greatest nematicidal effect was caused by a combination of the three products. The treatment with 1,3-D limited its nematicidal efficacy to the first crop only. Fumigant integration with TH and OF also resulted in the greatest increases of plant growth and yield. Therefore, the integrated management of root-knot nematodes with a soil fumigant, a bionematicide as T. harzianum and a source of organic matter demonstrated effective nematode suppression though limiting the number of chemical applications.
RESUMO
The activation of TNF receptors can lead to cell death with a mechanism of cell necrosis regulated genetically and distinct from apoptosis which is defined as necroptosis. Necroptosis has been one of the most studied emerging cell death/signaling pathways in recent years, especially in light of the role of this process in human disease. However, not all regulatory components of TNF signaling have been identified in relation to both physiological and pathological conditions. In 2008, Spata2 (Spermatogenesis-associated protein 2) was identified as one of the seven fundamental genes for the cellular signaling network that regulates necroptosis and apoptosis. This gene had been cloned by our group and named Spata2 as its expression was found to be elevated in the testis compared to other tissues, localized at the Sertoli cell level and FSH-dependent. More recently, it has been demonstrated that deletion of Spata2 gene causes increased inhibin α expression and attenuated fertility in male mice. However, more importantly, five recently published reports have highlighted that SPATA2 is crucial for recruiting CYLD to the TNFR1 signaling complex thus promoting its activation leading to TNF-induced cell death. Loss of SPATA2 increases transcriptional activation of NF-kB and limits TNF-induced necroptosis. Here we will discuss these important findings regarding SPATA2 and, in particular, focus attention on the evidence that suggests a role for this protein in the TNF signaling pathway.
Assuntos
Neoplasias , Espermatogênese , Humanos , Masculino , Camundongos , Animais , Espermatogênese/genética , Transdução de Sinais , NF-kappa B/genética , NF-kappa B/metabolismo , Receptores do Fator de Necrose Tumoral/metabolismo , ProteínasRESUMO
The surface of all animal cells is coated with a layer of carbohydrates linked in various ways to the outer side of the plasma membrane. These carbohydrates are mainly bound to proteins in the form of glycoproteins and proteoglycans and together with the glycolipids constitute the so-called glycocalyx. In particular, the endothelial glycocalyx that covers the luminal layer of the endothelium is composed of glycosaminoglycans (heparan sulphate -HS and hyaluronic acid -HA), proteoglycans (syndecans and glypicans) and adsorbed plasma proteins. Thanks to its ability to absorb water, this structure contributes to making the surface of the vessels slippery but at the same time acts by modulating the mechano-transduction of the vessels, the vascular permeability and the adhesion of leukocytes in thus regulating several physiological and pathological events. Among the various enzymes involved in the degradation of the glycocalyx, heparanase (HPSE) has been shown to be particularly involved. This enzyme is responsible for the cutting of heparan sulfate (HS) chains at the level of the proteoglycans of the endothelial glycocalyx whose dysfunction appears to have a role in organ fibrosis, sepsis and viral infection. In this mini-review, we describe the mechanisms by which HPSE contributes to glycocalyx remodeling and then examine the role of glycocalyx degradation in the development of pathological conditions and pharmacological strategies to preserve glycocalyx during disease pathogenesis.
RESUMO
BACKGROUND: Currently, there are solely weak recommendations in the enhanced recovery after surgery (ERAS) protocol regarding the role of preoperative physical activity and prehabilitation in patients undergoing colorectal surgery. Studies in heterogenous groups showed contradictory results regarding the impact of prehabilitation on the reduction of postoperative complications. The aim of this study was to assess the impact of prehabilitation on postoperative complications in patients undergoing colorectal surgery within an ERAS protocol. METHODS: Between July 2016 and June 2019, a single-center, blinded, randomized controlled trial designed to test whether physiotherapeutic prehabilitation vs. normal physical activities prior to colorectal surgery may decrease morbidity within a stringent ERAS protocol was carried out. The primary endpoint was postoperative complications assessed by Comprehensive Complications Index (CCI®). Primary and secondary endpoints for both groups were analyzed and compared. RESULTS: A total of 107 patients (54 in the prehabilitation enhanced recovery after colorectal surgery [pERACS] group and 53 in the control group) were included in the study and randomized. Dropout rate was 4.5% (n = 5). Baseline characteristics were comparable between the pERACS and control groups. The percentage of colorectal adenocarcinoma was low in both groups (pERACS 32% vs. control 23%, p = 0.384). Almost all patients underwent minimally invasive surgery in both groups (96% vs. 98%, p = 1.000). There was no between-group difference in the primary outcome, as the mean CCI at 30-day postoperative in the pERACS group was 18 (SD 0-43) compared to 15 (SD 0-49) in the control group (p = 0.059). Secondary outcome as complications assessed according to Clavien-Dindo, length of hospital stay, reoperation rate, and mortality showed no difference between both groups. CONCLUSIONS: Routine physiotherapeutic prehabilitation has no additional benefit for patients undergoing colorectal surgery within an ERAS protocol. TRIAL REGISTRATION: ClinicalTrial.gov: ID: NCT02746731; Institution Ethical Board Approval: KEK-ZH Nr. 2016-00,229.
Assuntos
Cirurgia Colorretal , Procedimentos Cirúrgicos do Sistema Digestório , Procedimentos Cirúrgicos do Sistema Digestório/efeitos adversos , Humanos , Tempo de Internação , Morbidade , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/prevenção & controle , Exercício Pré-OperatórioRESUMO
PURPOSE: Growing evidence suggests that early mobilization benefits intensive care unit (ICU) patients. However, national practices and the culture of individual ICUs influence mobilization activities. MATERIALS AND METHODS: In a 1-day, Swiss point prevalence study conducted in 35 ICUs (representing 45% of all ICUs), the highest level of mobilization for mechanically ventilated patients was characterized using the validated ICU Mobility Scale, along with data collection for potential safety events and mobilization barriers. RESULTS: Among 161 mechanically ventilated patients, a total of 33% (n = 53) had active mobilization, with walking achieved by only 2% (n = 4). More severe organ failure was associated with lower mobilization (respiratory Sequential Organ Failure Assessment score: P = .037, cardiac: P = .008, neurology: P < .001). Barriers to mobilization were reported in 71% (n = 115), with deep sedation significantly higher among patients receiving passive versus active mobilization (14% vs 0%, P = .005). Potential safety events occurred in 20% (n = 33) of patients without significant differences between passive and active mobilization. Availability of physiotherapists and appropriate equipment were not reported barriers. CONCLUSION: Mobilization during mechanical ventilation occurred infrequently with greater organ failure associated with lower mobilization. Addressing the identified modifiable barriers via structured efforts to achieve multidisciplinary culture change is essential to decrease the common use of bed rest in Swiss ICUs.
Assuntos
Deambulação Precoce , Unidades de Terapia Intensiva/estatística & dados numéricos , Limitação da Mobilidade , Respiração Artificial/estatística & dados numéricos , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Escores de Disfunção Orgânica , SuíçaRESUMO
BACKGROUND: A key element in the postoperative phase of the standardized Enhanced Recovery After Surgery (ERAS) treatment pathways is mobilization. Currently, there are no recommendations in the ERAS guidelines for preoperative physical activity. Patients undergoing major surgery are prone to functional decline due to the impairment of muscle, cardiorespiratory, and neurological function as a response to surgical stress. It has been shown that preoperative physical training reduces postoperative complications. To date, there are limited studies that investigate preoperative physical training combined with ERAS. OBJECTIVE: The aim of this study is to assess the impact of tailored physical training prior to colorectal surgery conducted according to an ERAS protocol on overall morbidity. This study proposes the initial hypothesis that 3-6 weeks of prehabilitation before elective colorectal surgery may improve postoperative outcome and reduce complication rates, assessed using the Comprehensive Complication Index. The primary objective is to evaluate overall morbidity due to postoperative complications. Additionally, complications are assessed according to the Clavien-Dindo classification, length of stay, readmission rate, mortality rate, and treatment-related costs. METHODS: The prehabilitation Enhanced Recovery After colorectal Surgery (pERACS) study is a single-center, single-blinded prospective randomized controlled trial. Patients scheduled for colorectal resections are randomly assigned either to the prehabilitation group or the control group. All patients are treated with the ERAS pathway for colorectal resections according to a standardized study schedule. Sample size calculation performed by estimating a clinically relevant 25% reduction of postoperative complications (alpha=.05, power 80%, dropout rate of 10%) resulted in 56 randomized patients per group. RESULTS: Following ethical approval of the study protocol, the first patient was included in June 2016. At this time, a total of 40 patients have been included; 27 patients terminated the study by the end of March 2017. Results are expected to be published in 2018. CONCLUSIONS: The pERACS trial is a single-center, single-blinded prospective randomized controlled trial to assess the impact of tailored physical training prior to colorectal surgery, conducted according to an ERAS protocol, in order to evaluate overall morbidity. TRIAL REGISTRATION: Clinicaltrials.gov NCT02746731; https://clinicaltrials.gov/ct2/show/NCT02746731 (Archived by WebCite at http://www.webcitation.org/6tzblGwge).
RESUMO
BACKGROUND: Physical activity promotion in people with Chronic Obstructive Pulmonary Disease (COPD) is focus of research and public health. Patient-centred interventions like counselling are promising approaches to help patients reducing sedentary behaviour. Aim of the present study is to investigate if a physical activity counselling program during pulmonary rehabilitation increases physical activity level in daily life in people with COPD. METHODS: A two-armed, single blind randomised controlled trial including 56 people with COPD will be conducted in an outpatient pulmonary rehabilitation. Patients will participate in a 12-week-rehabilitation program; individuals randomized to the interventional group will additionally participate in five counselling sessions with a physiotherapist, based on the principles of motivational interviewing. The participants' physical activity level will be measured using an accelerometer (SenseWear Pro®) before, directly and 3 months after pulmonary rehabilitation. Semi-structured interviews will be conducted to learn more about barriers and facilitators regarding daily physical activity. DISCUSSION: If the strategy successfully improves the physical activity level in people with COPD, counselling might be implemented in pulmonary rehabilitation. TRIAL REGISTRATION: Clinical Trials.gov NCT02455206 (05/21/2015), Swiss National Trails Portal SNCTP000001426 (05/21/2015).
Assuntos
Aconselhamento/métodos , Exercício Físico , Motivação , Doença Pulmonar Obstrutiva Crônica/reabilitação , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Qualidade de Vida , Projetos de Pesquisa , Método Simples-Cego , Suíça , Teste de CaminhadaRESUMO
BACKGROUND: We report the radiation-induced late morbidity observed in our prospective series of Wilms tumor patients treated at the Second University of Naples. METHODS: From April 1981 to April 2000, 98 patients were referred at our institution for treatment of Wilms tumor. Among them, 51 underwent radiotherapy and 34 patients had a minimum follow-up of 5 years. Doses of irradiation and treatment portals were those recommended by the guidelines of the Italian Association of Haematology and Paediatric Oncology according to risk stratification. All eligible patients were reviewed for follow-up every 6 months. Median follow-up was 181 months (range 60 to 264 months). RESULTS: Eleven out of 34 patients (32%) did not suffer from any significant late side effect. Out of the remaining 23 (68%), 14 (41%) suffered from scoliosis presenting between 60 and 180 months from completion of treatment. Muscular hypoplasia, length inequality, kyphosis, and iliac wing hypoplasia were seen respectively, in 4 (12%), 4 (12%), 5 (15%), and 3 (9%) patients. The incidence of intestinal occlusion was 20%. One patient had chronic renal insufficiency. Four out of 13 female patients reported ovarian failure. Three out of the 7 patients who had radiotherapy to the lung developed radiation-pneumonitis. Radiation-induced heart disease was seen in 3 (9%) patients. Three patients (9%) suffered from second malignancies arising within the irradiated volume. CONCLUSIONS: Our data confirm the high incidence of late radiation morbidity in patients undergoing adjuvant radiotherapy for Wilms tumor. For most organ systems there is a correlation between total dose, morbidity rates, and degree of severity.
Assuntos
Neoplasias Renais/epidemiologia , Neoplasias Renais/radioterapia , Neoplasias Induzidas por Radiação/epidemiologia , Lesões por Radiação/epidemiologia , Tumor de Wilms/epidemiologia , Tumor de Wilms/radioterapia , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Incidência , Lactente , Masculino , Morbidade , Radioterapia/efeitos adversos , Radioterapia/estatística & dados numéricos , Fatores de Risco , Índice de Gravidade de Doença , Fatores de TempoRESUMO
The full-length cDNA and the corresponding gene of the heat shock protein 90, Mt-Hsp90, were isolated and characterized in the plant parasitic nematode Meloidogyne artiellia. The full-length Mt-Hsp90 cDNA contained a 5' untranslated region (UTR) of 45 bp with the 22 bp trans-spliced leader SL1, an ORF of 2172 bp encoding a polypeptide of 723 amino acids and a 3' UTR of 191 bp. The deduced amino acid sequence of Mt-hsp90 showed high similarity with other known Hsp90s. Five conserved amino acid signatures indicated that Mt-hsp90 is a cytosolic member of the Hsp90 family. The gene consists of 10 exons and 9 introns, a more expanded gene structure compared to the corresponding Caenorhabditis elegans gene, daf-21. Mt-hsp90 gene was constitutively expressed at high levels in all developmental stages of M. artiellia. Egg masses and second stage juveniles (J2s) were exposed at 5 degrees and 30 degrees C for different periods of times in order to explore the impact of adverse temperature on Mt-hsp90 gene expression. Expression levels of Mt-hsp90 were examined by fluorescent real-time PCR. At 30 degrees C a burst of expression for Mt-hsp90 was observed in J2s after 2 h of heat shock treatment, then expression dropped with longer exposing times, although remaining still relatively high after 24 h. This temperature did not affect Mt-hsp90 gene expression in the egg masses. However, egg masses exposed at 5 degrees C showed a little but gradual increase in the mRNA level with time. By contrast, no significant changes in the Mt-hsp90 level were observed in J2s exposed to cold. These data show that egg masses and J2s exposed to cold and heat stresses have different expression profiles suggesting that Mt-Hsp90 may provide a link between environmental conditions and the life cycle of the nematode.
Assuntos
Proteínas de Choque Térmico HSP90/genética , Proteínas de Helminto/genética , Temperatura , Tylenchoidea/crescimento & desenvolvimento , Tylenchoidea/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , DNA Complementar/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Genes de Helmintos , Íntrons , Dados de Sequência Molecular , Tylenchoidea/genéticaRESUMO
ABSTRACT The effect of different combinations of temperatures and exposure times on the mortality of Heterodera schachtii eggs was assessed in two different experiments under laboratory conditions. In the first experiment, cysts in water were exposed to 25, 35, 37.5, 40, 42.5, 45, 47.5, 50, or 52.5 degrees C for a maximum period of 2 h. In the second experiment, cysts in naturally infested soil were exposed to 25, 32.5, 35, 37.5, 40, 42.5, or 45 degrees C for a minimum period of 2 h to a maximum of 2,048 h. Viability of eggs in cysts was assessed by a hatching test in 3 mM zinc chloride solution. Viability in water was suppressed after 2-h exposure at 50 degrees C and inhibited after 1 to 2 h at 52.5 degrees C. Emergence of juveniles from cysts in soil was greater at the lower temperature x exposure time combinations and suppressed at higher combinations. Egg mortality started after exposure for 256 h at 40 degrees C, 32 h at 42.5 degrees C, and 16 h at 45 degrees C, and 81, 31, and 7 h of exposure were necessary to kill 50% of the nematode egg population at 40, 42.5, and 45 degrees C, respectively. The data fitted the models P(t) = P(0)10(-t/ (q + mT)) and P(T1) = P(T0)10(-T/(z - pt)) for m = -0.0111, q = 0.8238, z = 2.444, and p = -0.23.
RESUMO
Progressive or recurrent high-grade gliomas are characterized by a very poor prognosis, and the relevance of second-line chemotherapy is still unassessed. Although it has been reported that liposomal anthracyclines and carboplatin show some activity in these patients, their association has never been investigated. We have treated six children with recurrent high-grade glioma after surgery, radiotherapy and chemotherapy, and one child with progressive teratoid/rhabdoid tumor with the combination of liposomal daunorubicin and carboplatin plus etoposide. Five out of seven children showed a major response and the 29 month progression-free survival was 38%. The above regimen was feasible and children showed only little and transient hematological toxicity. In our opinion, these results justify further investigation of the above combination chemotherapy for recurrent or progressive malignant brain tumors in children.