Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
1.
Proteomics ; 23(1): e2200251, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-35861729

RESUMO

Açaí palm (Euterpe oleracea Mart.) seeds are a rich source of mannans, which can be used to generate bioethanol or be converted to high-value D-mannose, in addition to being a source of polyphenols with beneficial health properties. Here, we present a quantitative proteome dataset of açaí seeds at four stages of development (S1, S2, S3, and S4 stages), in which 2465 high confidence proteins were identified and 524 of them show statistically different abundance profiles during development. Several enzymes involved in the biosynthesis of nucleotide-sugars were quantified, especially those dedicated to the formation of GDP-mannose, which showed an increase in abundance between stages S1 and S3. Our data suggest that linear mannans found abundantly in endosperm cell walls are initially deposited as galactomannans, and during development lose the galactosyl groups. Two isoforms of alpha-galactosidase enzymes showed significantly increased abundances in the S3 and S4 stages. Additionally, we quantified the enzymes participating in the central pathway of flavonoid biosynthesis responsible for the formation of catechin and epicatechin, which are subunits of procyanidins, the main class of polyphenols in the açaí seeds. These proteins showed the same pattern of deposition, in which higher abundances were seen in the S1 and S2 stages.


Assuntos
Euterpe , Mananas , Antioxidantes , Proteômica , Sementes/química , Polifenóis/análise , Extratos Vegetais
2.
Clin Gastroenterol Hepatol ; 20(2): 362-371.e23, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-33991691

RESUMO

BACKGROUND & AIMS: Nonpedunculated colorectal polyps are normally endoscopically removed to prevent neoplastic progression. Delayed bleeding is the most common major adverse event. Clipping the resection defect has been suggested to reduce delayed bleedings. Our aim was to determine if prophylactic clipping reduces delayed bleedings and to analyze the contribution of polyp characteristics, extent of defect closure, and antithrombotic use. METHODS: An individual patient data meta-analysis was performed. Studies on prophylactic clipping in nonpedunculated colorectal polyps were selected from PubMed, Embase, Web of Science, and Cochrane database (last selection, April 2020). Authors were invited to share original study data. The primary outcome was delayed bleeding ≤30 days. Multivariable mixed models were used to determine the efficacy of prophylactic clipping in various subgroups adjusted for confounders. RESULTS: Data of 5380 patients with 8948 resected polyps were included from 3 randomized controlled trials, 2 prospective, and 8 retrospective studies. Prophylactic clipping reduced delayed bleeding in proximal polyps ≥20 mm (odds ratio [OR], 0.62; 95% confidence interval [CI], 0.44-0.88; number needed to treat = 32), especially with antithrombotics (OR, 0.59; 95% CI, 0.35-0.99; number needed to treat = 23; subgroup of anticoagulants/double platelet inhibitors: n = 226; OR, 0.40; 95% CI, 0.16-1.01; number needed to treat = 12). Prophylactic clipping did not benefit distal polyps ≥20 mm with antithrombotics (OR, 1.41; 95% CI, 0.79-2.52). CONCLUSIONS: Prophylactic clipping reduces delayed bleeding after resection of nonpedunculated, proximal colorectal polyps ≥20 mm, especially in patients using antithrombotics. No benefit was found for distal polyps. Based on this study, patients can be identified who may benefit from prophylactic clipping. (PROSPERO registration number CRD42020104317.).


Assuntos
Pólipos do Colo , Pólipos do Colo/etiologia , Pólipos do Colo/cirurgia , Colonoscopia/efeitos adversos , Humanos , Hemorragia Pós-Operatória/epidemiologia , Hemorragia Pós-Operatória/etiologia , Hemorragia Pós-Operatória/prevenção & controle , Estudos Prospectivos , Estudos Retrospectivos , Instrumentos Cirúrgicos
3.
Surg Endosc ; 35(10): 5422-5429, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34076765

RESUMO

BACKGROUND: Colorectal endoscopic mucosal resection (EMR) is an effective, safe, and minimally invasive treatment for large lateral spreading and sessile polyps. The reported high recurrence rate of approximately 20% is however one of the major drawbacks. Several endoscopic interventions have been suggested to reduce recurrence rates. We conducted a systematic review and meta-analysis to assess the efficacy of endoscopic interventions targeting the EMR margin to reduce recurrence rates. METHODS: We searched in PubMed and Ovid for studies comparing recurrence rates after interventions targeting the EMR margin with standard EMR. The primary outcome was the recurrence rate at the first surveillance colonoscopy (SC1) assessed histologically or macroscopically. For the meta-analysis, risk ratios (RRs) were calculated and pooled using a random effects model. The secondary outcome was post-procedural complication rates. RESULTS: Six studies with a total of 1335 lesions were included in the meta-analysis. The techniques performed in the intervention group targeting the resection margin were argon plasma coagulation, snare tip soft coagulation, extended EMR, and precutting EMR. The interventions reduced the adenoma recurrence rate with more than 50%, resulting in a pooled RR of 0.37 (95% CI 0.18, 0.76) comparing the intervention group with the control groups. Overall post-procedural complication rates did not increase significantly in the intervention arm (RR 1.30; 95% CI 0.65, 2.58). CONCLUSION: Interventions targeting the EMR margin decrease recurrence rates and may not result in more complications.


Assuntos
Pólipos do Colo , Neoplasias Colorretais , Ressecção Endoscópica de Mucosa , Colonoscopia , Neoplasias Colorretais/cirurgia , Humanos , Recidiva Local de Neoplasia/epidemiologia , Recidiva Local de Neoplasia/prevenção & controle , Resultado do Tratamento
4.
Bratisl Lek Listy ; 122(12): 912-917, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34904854

RESUMO

OBJECTIVES: This study aimed to investigate the wound healing activity of liposomal Carpobrotus edulis powder extract (CEPE) formulation on incisional and excisional wounds in rat. BACKGROUND: In the event of any damage, the damaged tissue undergoes a process of regenerating itself, which is called wound healing. METHODS: Centella asiatica extract (CAE) was used as the reference molecule in the study. The wound healing process was tested by using the excisional and incisional wound model. On the 12th day of the study, maximum stress, stress, % of elongation values were evaluated in the incisional wound. Also; histological parameters and macroscopic photographic analyses were evaluated in the excisional wound. RESULTS: In the photo evaluations, the improvement was more prominent in both CAE and CEPE groups than in the control group. Histological evaluation showed that CEPE group had significant wound healing activity compared to the control and CAE groups. Axial tensile-elongation experiments in incisional wound tissue show that there was no significant difference between CAE and CEPE groups. CONCLUSION: Liposomal formulations of C.edulis extract were found to have positive effects on the healing process, both on excisional and incisional wound tissues (Tab. 2, Fig. 3, Ref. 30).


Assuntos
Pele , Cicatrização , Animais , Extratos Vegetais/farmacologia , Ratos
5.
Scand J Gastroenterol ; 55(6): 737-744, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32516002

RESUMO

Background: Delayed bleeding (DB) occurs in ∼10% after colorectal EMR. Prophylactic clipping (PC) was reported to significantly decrease DB-rate in proximal lesions ≥2 cm.Objective: Our aim was to determine which predefined variables contribute to using PC in clinical practice.Methods: We performed an international discrete choice experiment (DCE) among ∼500 endoscopists. Relevant variables for PC use were selected by EMR experts: previous DB, anticoagulants, polyp size, morphology, location, intraprocedural bleeding and visible vessel(s). Respondents answered case scenarios with various variable combinations, each time choosing only one scenario for PC, or the 'none' option. Part-worth utilities and importance weights were calculated using HB regression. Subsequently, a predictive model was created to calculate the likelihood of endoscopists choosing PC in any given case.Results: The survey was completed by 190 EMR endoscopists from 17 countries. In total, 8% would never use PC, whereas 30.9% never chose the 'none' option. All variables except polyp type were significant in decision-making for PC (p < .01). The most important factor was anticoagulant use, accounting for 22.5% in decision-making. Polyps <2 cm were considered eligible for PC by 14% in the presence of high-weighing factors such as anticoagulant use. No significant differences were found between high and low-to-moderately experienced endoscopists.Conclusions: PC after EMR is often considered useful by endoscopists, usually based on risk factors for DB. Anticoagulant use was the most important factor in decision-making for PC, independent of endoscopist experience. Although not considered cost-effective, one in seven endoscopists chose PC for adenomas <2 cm.


Assuntos
Comportamento de Escolha , Competência Clínica , Pólipos do Colo/cirurgia , Colonoscopia/métodos , Hemorragia Gastrointestinal/prevenção & controle , Adenoma/cirurgia , Colonoscopia/efeitos adversos , Colonoscopia/instrumentação , Neoplasias Colorretais/cirurgia , Hemorragia Gastrointestinal/etiologia , Humanos , Países Baixos , Fatores de Risco , Instrumentos Cirúrgicos
6.
Artigo em Inglês | MEDLINE | ID: mdl-31398391

RESUMO

The acid-base status is a tightly regulated physiological process, resulting from a balance of ions in the organism relevant to acid-base. The efficiency of the regulatory systems importantly determines the compensatory pH changes for a given disturb. Vertebrates minimize (or compensate) an acid-base disturb by general processes, which include ion transfer and/or PCO2 changes. Acid-base adjustment in fish is predominantly achieved by branchial exchange of acid-base relevant ions with correlated change in plasma HCO3- levels. Conversely, land vertebrates change blood PCO2 through ventilatory process and hence respiratory control of acid-base regulation plays an important role as a compensatory mechanism. Lungfishes (Dipnoi) have central position on vertebrate's evolution being considered as the sister group to the tetrapods. With an aquatic life mode, lungfish share similarities of respiratory function with tetrapods. This article reviews evidence showing that lungfish's respiratory system regulates acid-base status, like terrestrial ectothermic vertebrates. In the South American lungfish, Lepidosiren paradoxa, the presence of central CO2/pH chemoreceptors was unequivocally described. Also, the blood PCO2 and acid-base status are typical of a terrestrial vertebrate. These aspects are discussed under different environmental conditions that require respiratory acid-base adjustments, such as, exposure to hypercarbia, hypoxia, high temperature and aestivation. Interesting questions regarding the location and cell phenotype of CO2/pH central and peripheral chemoreceptors remain an open field to be explored in lungfish.


Assuntos
Equilíbrio Ácido-Base/fisiologia , Peixes/fisiologia , Pulmão/fisiologia , Vertebrados/fisiologia , Animais , Dióxido de Carbono/metabolismo , Hipóxia Celular/fisiologia , Células Quimiorreceptoras/metabolismo , Células Quimiorreceptoras/fisiologia , Peixes/sangue , Peixes/metabolismo , Brânquias/metabolismo , Brânquias/fisiologia , Temperatura Alta , Concentração de Íons de Hidrogênio , Transporte de Íons/fisiologia , Pulmão/metabolismo , Oxigênio/metabolismo , Respiração , Vertebrados/metabolismo
7.
Abdom Radiol (NY) ; 47(9): 3338-3344, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-34357434

RESUMO

OBJECTIVES: Over 2500 percutaneous transhepatic cholangiography and biliary drainage (PTCD) procedures are yearly performed in the Netherlands. Most interventions are performed for treatment of biliary obstruction following unsuccessful endoscopic biliary cannulation. Our aim was to evaluate complication rates and risk factors for complications in PTCD patients after failed ERCP. METHODS: We performed an observational study collecting data from a cohort that was subjected to PTCD during a 5-year period in one academic and four teaching hospitals. Primary objective was the development of infectious (sepsis, cholangitis, abscess, or cholecystitis) and non-infectious complications (bile leakage, severe hemorrhage, etc.) and mortality within 30 days of the procedure. Subsequently, risk factors for complications and mortality were analyzed with a multilevel logistic regression analysis. RESULTS: A total of 331 patients underwent PTCD of whom 205 (61.9%) developed PTCD-related complications. Of the 224 patients without a pre-existent infection, 91 (40.6%) developed infectious complications, i.e., cholangitis in 26.3%, sepsis in 24.6%, abscess formation in 2.7%, and cholecystitis in 1.3%. Non-infectious complications developed in 114 of 331 patients (34.4%). 30-day mortality was 17.2% (N = 57). Risk factors for infectious complications included internal drainage and drain obstruction, while multiple re-interventions were a risk factor for non-infectious complications. CONCLUSION: Both infectious and non-infectious complications are frequent after PTCD, most often due to biliary drain obstruction.


Assuntos
Colangite , Colecistite , Colestase , Sepse , Abscesso , Colangiografia/métodos , Colangite/diagnóstico por imagem , Colangite/etiologia , Colestase/diagnóstico por imagem , Colestase/terapia , Drenagem/métodos , Humanos
8.
Trials ; 22(1): 63, 2021 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-33461579

RESUMO

BACKGROUND: Endoscopic mucosal resection (EMR) for large colorectal polyps is in most cases the preferred treatment to prevent progression to colorectal carcinoma. The most common complication after EMR is delayed bleeding, occurring in 7% overall and in approximately 10% of polyps ≥ 2 cm in the proximal colon. Previous research has suggested that prophylactic clipping of the mucosal defect after EMR may reduce the incidence of delayed bleeding in polyps with a high bleeding risk. METHODS: The CLIPPER trial is a multicenter, parallel-group, single blinded, randomized controlled superiority study. A total of 356 patients undergoing EMR for large (≥ 2 cm) non-pedunculated polyps in the proximal colon will be included and randomized to the clip group or the control group. Prophylactic clipping will be performed in the intervention group to close the resection defect after the EMR with a distance of < 1 cm between the clips. Primary outcome is delayed bleeding within 30 days after EMR. Secondary outcomes are recurrent or residual polyps and clip artifacts during surveillance colonoscopy after 6 months, as well as cost-effectiveness of prophylactic clipping and severity of delayed bleeding. DISCUSSION: The CLIPPER trial is a pragmatic study performed in the Netherlands and is powered to determine the real-time efficacy and cost-effectiveness of prophylactic clipping after EMR of proximal colon polyps ≥ 2 cm in the Netherlands. This study will also generate new data on the achievability of complete closure and the effects of clip placement on scar surveillance after EMR, in order to further promote the debate on the role of prophylactic clipping in everyday clinical practice. TRIAL REGISTRATION: ClinicalTrials.gov NCT03309683 . Registered on 13 October 2017. Start recruitment: 05 March 2018. Planned completion of recruitment: 31 August 2021.


Assuntos
Pólipos do Colo , Ressecção Endoscópica de Mucosa , Colo/cirurgia , Pólipos do Colo/cirurgia , Colonoscopia , Ressecção Endoscópica de Mucosa/efeitos adversos , Humanos , Estudos Multicêntricos como Assunto , Países Baixos , Hemorragia Pós-Operatória/etiologia , Hemorragia Pós-Operatória/prevenção & controle , Ensaios Clínicos Controlados Aleatórios como Assunto , Instrumentos Cirúrgicos
9.
Indian J Pathol Microbiol ; 63(1): 19-24, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32031117

RESUMO

BACKGROUND: Metastasis associated colon cancer gene 1 (MACC1) is a gene that was first described as a c-Met transcription regulator causing the progression of colon cancer. In this study, protein and messenger RNA (mRNA) expression of MACC1 in breast cancer and its relationship with clinicopathological prognostic parameters were investigated. METHODS: Sixty-six cases with tumors underwent radical mastectomy for invasive ductal carcinoma and 25 control cases operated for mammoplasty were included in the study. In paraffin blocks of tumor and control tissues, MACC1 expression was investigated by the immunohistochemical method and Real-time polymerase chain reaction (Real-Time PCR). In addition, vascular endothelial growth factor (VEGF) expression was examined immunohistochemically in tumor tissues. The relationship between MACC1 expression in tumor tissues, clinicopathological prognostic parameters, and VEGF was investigated. RESULTS: In this study, protein and mRNA expressions of MACC1 were found to be higher in tumor tissues compared with normal breast tissues. MACC1 protein expression was also associated with significant poor prognostic markers, such as high histologic grade, ER negativity, and HER2 positivity. However, there was no correlation between MACC1 expression and VEGF. CONCLUSION: According to these results, MACC1 expression may be a marker of breast carcinoma as well as an independent predictor of poor prognosis. In addition, MACC1 may not affect angiogenesis in breast cancer or even if it has an effect, it may not be associated with VEGF. However, it would be appropriate to support these results in a larger series by investigating in vivo and in vitro studies.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/genética , Transativadores/genética , Adulto , Biomarcadores Tumorais , Carcinoma Ductal de Mama/cirurgia , Estudos de Casos e Controles , Feminino , Humanos , Imuno-Histoquímica , Mastectomia , Pessoa de Meia-Idade , Prognóstico , Fator A de Crescimento do Endotélio Vascular/genética
10.
Biotech Histochem ; 94(3): 180-188, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30409033

RESUMO

Laurocerasus officinalis Roem. (syn: Prunus laurocerasus L.) is a member of Rosaceae family. We investigated the antimicrobial and antioxidant activity of L. officinalis Roem in wound healing both in vivo and in vitro using an excisional wound model model in mice. We used four groups of eight mice as follows: untreated (control), empty gel, extract + gel (L. officinalis + gel), and Madecassol® groups. All treatments were applied topically once daily. The scar area, percentage wound closure and epithelization time were measured. L. officinalis promoted wound healing and increased granulation tissue, epidermal regeneration and angiogenesis. L. officinalis extract, which is known for its antioxidant and antimicrobial activities, may be useful for promoting wound healing.


Assuntos
Extratos Vegetais/farmacologia , Rosaceae/química , Cicatrização/efeitos dos fármacos , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Metanol , Camundongos , Camundongos Endogâmicos BALB C , Extratos Vegetais/química
11.
Sci Adv ; 4(10): eaap7567, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30324132

RESUMO

Very large eruptions (>50 km3) and supereruptions (>450 km3) reveal Earth's capacity to produce and store enormous quantities (>1000 km3) of crystal-poor, eruptible magma in the shallow crust. We explore the interplay between crustal evolution and volcanism during a volcanic flare-up in the Taupo Volcanic Zone (TVZ, New Zealand) using a combination of quartz-feldspar-melt equilibration pressures and time scales of quartz crystallization. Over the course of the flare-up, crystallization depths became progressively shallower, showing the gradual conditioning of the crust. Yet, quartz crystallization times were invariably very short (<100 years), demonstrating that very large reservoirs of eruptible magma were transient crustal features. We conclude that the dynamic nature of the TVZ crust favored magma eruption over storage. Episodic tapping of eruptible magmas likely prevented a supereruption. Instead, multiple very large bodies of eruptible magma were assembled and erupted in decadal time scales.

12.
Biotech Histochem ; 92(4): 274-282, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28426256

RESUMO

We investigated the wound healing efficacy of the Foeniculum vulgare compounds, fenchone and limonene, using an excisional cutaneous wound model in rats. An excision wound was made on the back of the rat and fenchone and limonene were applied topically to the wounds once daily, separately or together, for 10 days. Tissue sections from the wounds were evaluated for histopathology. The healing potential was assessed by comparison to an untreated control group and an olive oil treated sham group. We scored wound healing based on epidermal regeneration, granulation tissue thickness and angiogenesis. After day 6, wound contraction with limonene was significantly better than for the control group. Ten days after treatment, a significant increase was observed in wound contraction and re-epithelialization in both fenchone and limonene oil treated groups compared to the sham group. Groups treated with fenchone and with fenchone + limonene scored significantly higher than the control group, but the difference was not statistically significant compared to the olive oil treated group. Our findings support the beneficial effects of fenchone and limonene for augmenting wound healing. The anti-inflammatory and antimicrobial activities of fenchone and limonene oil increased collagen synthesis and decreased the number of inflammatory cells during wound healing and may be useful for treating skin wounds.


Assuntos
Cicloexenos/farmacologia , Foeniculum/química , Norbornanos/farmacologia , Óleos Voláteis/farmacologia , Terpenos/farmacologia , Cicatrização/efeitos dos fármacos , Animais , Canfanos , Cicloexenos/química , Imuno-Histoquímica , Limoneno , Masculino , Microscopia Eletrônica de Transmissão , Norbornanos/química , Azeite de Oliva/farmacologia , Extratos Vegetais/farmacologia , Ratos , Ratos Sprague-Dawley , Pele/efeitos dos fármacos , Terpenos/química
13.
Oncol Res ; 16(5): 225-33, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17294803

RESUMO

Tumor heterogeneity is an important feature that is especially involved in tumor aggressiveness. Multicellular tumor spheroids (MTS) may provide some benefits in different steps for investigation of the aggregation, organization, differentiation, and network formation of tumor cells in 3D space. This model offers a unique opportunity for improvements in the capability of a current strategy to detect the effect of an appropriate anticancer agent. The aim of this study was to investigate the cellular interactions and morphological changes following chemotherapy in a 3D breast cancer spheroid model. Distribution of the gap junction protein "connexin-43" and the tight junction protein "occludin" was investigated by immunohistochemistry. Cellular interactions were examined by using transmission and scanning electron microscopies as well as light microscopy with Giemsa staining after treating cells with doxorubicin, docetaxel, and doxorubicin/docetaxel combination. Statistical analyses showed significant changes and various alterations that were observed in all groups; however, the most prominent effect was detected in the doxorubicin/docetaxel combination group. Distinct composition as a vessel-like structure and a pseudoglandular pattern of control spheroids were detected in drug-administered groups. Immunohistochemical results were consistent with the ultrastructural changes. In conclusion, doxorubicin/docetaxel combination may be more effective than the single drug usage as shown in a 3D model. The MTS model has been found to be an appropriate and reliable method for the detection of the changes in the expression of cellular junction proteins as well as other cellular proteins occurring after chemotherapy. The MTS model can be used to validate the effects of various combinations or new chemotherapeutic agents as well as documentation of possible mechanisms of new drugs.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Neoplasias da Mama/tratamento farmacológico , Comunicação Celular , Doxorrubicina/farmacologia , Esferoides Celulares/efeitos dos fármacos , Taxoides/farmacologia , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Comunicação Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Terapia Combinada , Conexina 43/efeitos dos fármacos , Conexina 43/metabolismo , Docetaxel , Feminino , Humanos , Imuno-Histoquímica , Proteínas de Membrana/efeitos dos fármacos , Proteínas de Membrana/metabolismo , Microscopia Eletrônica de Transmissão e Varredura , Modelos Biológicos , Ocludina , Sensibilidade e Especificidade , Esferoides Celulares/metabolismo , Esferoides Celulares/patologia , Relação Estrutura-Atividade , Células Tumorais Cultivadas
14.
Oncol Rep ; 15(2): 335-40, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16391851

RESUMO

Multicellular tumor spheroid (MTS) represents a three-dimensional structural form of tumors in laboratory conditions, and it has the characteristics of avascular micrometastases or intervascular spaces of big tumors. Recent studies indicate that extracellular matrix (ECM) proteins play a critical role in tumor metastasis, therefore normal and cancer cells require an ECM for survival, proliferation and differentiation. Doxorubicin and Docetaxel are widely used in the therapy of breast cancer, as well as in in vivo and in vitro studies. In this study, we examined the effect of apoptosis and proliferation of cells on the human breast cancer cell line, MCF-7, by using p53, bcl-2 and Ki67 gene expression, and the tendency to metastasis with extracellular matrix proteins, laminin and type IV collagen after chemotherapy in the spheroid model. The apoptotic cell death in situ was detected by TUNEL method. TUNEL-positive cells and positive immunoreactivities of laminin, type IV collagen, p53 and, bcl-2 were detected in the control group. There was no laminin and type IV collagen immunoreactivities in spheroids of drug groups. While TUNEL-positive cells and p53 immunoreactivity were detected in Docetaxel, Doxorubicin and Docetaxel/Doxorubicin groups, p53 immunoreactivity was not observed in the Docetaxel group. There was no bcl-2 immunoreactivity in either drug group. In addition, we did not detect Ki67 immunoreactivity in both control and drug treatment groups. However, the absence of Ki67 protein in MCF-7 breast multicellular tumor spheroids is possibly related to the cells in G0 or S phase. These chemotherapeutic agents may affect the presence of ECM proteins in this in vitro model of micrometastasis of spheroids. These findings suggest that the possible mechanism of cell death in Doxorubicin and Docetaxel/Doxorubicin treatment groups is related to apoptosis through the p53 pathway. However, we considered the possibility that there is another control mechanism for the Docetaxel group.


Assuntos
Antineoplásicos/farmacologia , Apoptose/fisiologia , Doxorrubicina/farmacologia , Proteínas da Matriz Extracelular/metabolismo , Esferoides Celulares/efeitos dos fármacos , Taxoides/farmacologia , Apoptose/efeitos dos fármacos , Colágeno Tipo IV/efeitos dos fármacos , Docetaxel , Quimioterapia Combinada , Proteínas da Matriz Extracelular/efeitos dos fármacos , Feminino , Expressão Gênica/efeitos dos fármacos , Genes bcl-2/efeitos dos fármacos , Genes p53/efeitos dos fármacos , Humanos , Imuno-Histoquímica , Marcação In Situ das Extremidades Cortadas , Antígeno Ki-67/efeitos dos fármacos , Laminina/efeitos dos fármacos , Esferoides Celulares/metabolismo , Células Tumorais Cultivadas
15.
Oncol Rep ; 32(2): 641-9, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24927163

RESUMO

Cancer stem cells (CSCs) have the ability to self-renew similar to normal stem cells. This process is linked with metastasis and resistance to chemotherapy and radiotherapy. In the present study, we constructed an in vitro differentiation model for CSCs. CSCs isolated and proliferated for one passage were maintained as monolayers or spheroid-forming cells with serum included media for differentiation process. Differentiation of adhesion molecules and cellular ultrastructural properties were investigated and compared in both monolayer and spheroid cultures. CD133+/CD44+ cancer-initiating cells were isolated from DU-145 human prostate cancer cell line monolayer cultures and propagated as tumor spheroids and compared with the remaining heterogeneous cancer cell bulk population. Microarray-based gene expression analysis was applied to determine genes with differential expression and protein expression levels of candidates were analyzed by immunohistochemistry. Electron microscopy showed detailed analysis of morphology. TGFß1 was found to be significantly upregulated in monolayer CSCs. High expression levels of VCAN, COL7A1, ITGß3, MMP16, RPL13A, COL4A2 and TIMP1 and low expression levels of THBS1, MMP1 and MMP14 were detected when CSCs were maintained as serum-grown prostate CSC spheroids. Immunohistochemistry supported increased immunoreactivity of TGFß1 in monolayer cultures and VCAN in spheroids. CSCs were found to possess multipotential differentiation capabilities through upregulation and/or downregulation of their markers. TGFß1 is a triggering molecule, it stimulates versican, Col7A1, ITGß3 and, most importantly, the upregulation of versican was only detected in CSCs. Our data support a model where CSCs must be engaged by one or more signaling cascades to differentiate and initiate tumor formation. This mechanism occurs with intracellular and extracellular signals and it is possible that CSCc themselves may be a source for extracellular signaling. These molecules functioning in tumor progression and differentiation may help develop targeted therapy.


Assuntos
Colágeno Tipo VII/metabolismo , Integrina beta3/metabolismo , Células-Tronco Neoplásicas/metabolismo , Neoplasias da Próstata/patologia , Esferoides Celulares/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Versicanas/metabolismo , Antígeno AC133 , Antígenos CD/metabolismo , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Diferenciação Celular , Linhagem Celular Tumoral , Colágeno Tipo VII/genética , Regulação Neoplásica da Expressão Gênica , Glicoproteínas/metabolismo , Humanos , Receptores de Hialuronatos/metabolismo , Integrina beta3/genética , Masculino , Peptídeos/metabolismo , Neoplasias da Próstata/metabolismo , Fator de Crescimento Transformador beta1/genética , Versicanas/genética
16.
PLoS One ; 7(5): e37492, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22666359

RESUMO

Supereruptions violently transfer huge amounts (100 s-1000 s km(3)) of magma to the surface in a matter of days and testify to the existence of giant pools of magma at depth. The longevity of these giant magma bodies is of significant scientific and societal interest. Radiometric data on whole rocks, glasses, feldspar and zircon crystals have been used to suggest that the Bishop Tuff giant magma body, which erupted ~760,000 years ago and created the Long Valley caldera (California), was long-lived (>100,000 years) and evolved rather slowly. In this work, we present four lines of evidence to constrain the timescales of crystallization of the Bishop magma body: (1) quartz residence times based on diffusional relaxation of Ti profiles, (2) quartz residence times based on the kinetics of faceting of melt inclusions, (3) quartz and feldspar crystallization times derived using quartz+feldspar crystal size distributions, and (4) timescales of cooling and crystallization based on thermodynamic and heat flow modeling. All of our estimates suggest quartz crystallization on timescales of <10,000 years, more typically within 500-3,000 years before eruption. We conclude that large-volume, crystal-poor magma bodies are ephemeral features that, once established, evolve on millennial timescales. We also suggest that zircon crystals, rather than recording the timescales of crystallization of a large pool of crystal-poor magma, record the extended periods of time necessary for maturation of the crust and establishment of these giant magma bodies.


Assuntos
Quartzo/química , Erupções Vulcânicas , Cristalização , Difusão , Temperatura Alta , Termodinâmica , Fatores de Tempo , Temperatura de Transição
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA