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1.
J Appl Microbiol ; 130(1): 14-24, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32692438

RESUMO

The gut microbiome is well recognized to have a pivotal role in regulation of the health and behaviour of the host, affecting digestion, metabolism, immunity, and has been linked to changes in bones, muscles and the brain, to name a few. However, the impact of microgravity environment on gut bacteria is not well understood. In space environments, astronauts face several health issues including stress, high iron diet, radiation and being in a closed system during extended space missions. Herein, we discuss the role of gut bacteria in the space environment, in relation to factors such as microgravity, radiation and diet. Gut bacteria may exact their effects by synthesis of molecules, their absorption, and through physiological effects on the host. Moreover we deliberate the role of these challenges in the dysbiosis of the human microbiota and possible dysregulation of the immune system.


Assuntos
Meio Ambiente Extraterreno , Microbioma Gastrointestinal/fisiologia , Dieta/efeitos adversos , Disbiose/fisiopatologia , Humanos , Sistema Imunitário/fisiologia , Sistema Imunitário/efeitos da radiação , Radiação , Voo Espacial , Estresse Fisiológico/fisiologia , Estresse Fisiológico/efeitos da radiação , Ausência de Peso/efeitos adversos
2.
Clin Oral Investig ; 25(1): 295-310, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32495222

RESUMO

OBJECTIVES: Monocarboxylate transporters (MCT) 1, 2 and 4 play an important role in tumor metabolism. The amount of lactate transported by MCT's highly correlates with overall survival. Furthermore, glycolysis and hypoxia are possible causes for radiation resistance. MATERIALS AND METHODS: An oral squamous cell carcinoma cell line (CAL27, ATCC) was analyzed in an in vitro cell assay. After incubation with two different inhibitors for MCT1 (AR-C122982/SR-13800 and AR-C155858/SR-13801, Tocris) or for MCT4 (simvastatin, Sigma-Aldrich and 2-cyano-3-(4-hydroxyphenyl)-2-propenoic acid (CHC), Tocris), cells were irradiated with six gray with a Gammacell 2000 (Nuklear Data). For analysis, cell counting assay, wound healing assay, MTT assay and clonogenic assay were applied. RESULTS: Cell counting assay showed significant lower results for simvastatin, CHC and for the highest concentrations of AR-C122982 and AR-C155858 (p < 0.03). Additionally, cell counts decreased significantly with irradiation after 72 hours (p < 0.05) only for AR-C122982, CHC and simvastatin. The clonogenic assay confirmed these results with substantially reduced growth when incubated with CHC, simvastatin and AR-C155858 (p < 0.002). Furthermore, MCT1 and 4 inhibition led to highly reduced migration (p < 0.05). There again, comparing the wound healing assay of irradiated to non-irradiated tests showed contrary results (controls: p < 0.001; AR-C155858: p > 0.05; AR-C122982: p > 0.32; CHC: p > 0.1; simvastatin p > 0.1). The MTT assay presented significant effects with MCT1 and 4 inhibition (simvastatin/AR-C122982/CHC: p < 0.007). Irradiated cells showed significantly lower expression after only 48 h compared to non-irradiated cells (simvastatin/AR-C122982/CHC: p < 0.02). CONCLUSIONS: Inhibition of MCT, especially MCT4 may represent a possible tool to overcome radiation resistance in tumor cell lines. CLINICAL RELEVANCE: MCT Inhibitors may be used as a possible therapeutic approach to sensitize OSCC to radiation.


Assuntos
Carcinoma de Células Escamosas , Neoplasias Bucais , Radiação , Simportadores , Carcinoma de Células Escamosas/radioterapia , Contagem de Células , Linhagem Celular Tumoral , Humanos , Transportadores de Ácidos Monocarboxílicos
3.
Oral Dis ; 27(1): 52-63, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32531849

RESUMO

OBJECTIVE: Hyposalivation-related xerostomia is an irreversible, untreatable, and frequent condition after radiotherapy for head and neck cancer. Stem cell therapy is an attractive option of treatment, but demands knowledge of stem cell functioning. Therefore, we aimed to develop a murine parotid gland organoid model to explore radiation response of stem cells in vitro. MATERIALS AND METHODS: Single cells derived from murine parotid gland organoids were passaged in Matrigel with defined medium to assess self-renewal and differentiation potential. Single cells were irradiated and plated in a 3D clonogenic stem cell survival assay to assess submandibular and parotid gland radiation response. RESULTS: Single cells derived from parotid gland organoids were able to extensively self-renew and differentiate into all major tissue cell types, indicating the presence of potential stem cells. FACS selection for known salivary gland stem cell markers CD24/CD29 did not further enrich for stem cells. The parotid gland organoid-derived stem cells displayed radiation dose-response curves similar to the submandibular gland. CONCLUSIONS: Murine parotid gland organoids harbor stem cells with long-term expansion and differentiation potential. This model is useful for mechanistic studies of stem cell radiation response and suggests similar radiosensitivity for the parotid and submandibular gland organoids.


Assuntos
Neoplasias de Cabeça e Pescoço , Radiação , Xerostomia , Animais , Camundongos , Organoides , Glândula Parótida , Glândulas Salivares , Glândula Submandibular
4.
Nihon Hoshasen Gijutsu Gakkai Zasshi ; 76(12): 1281-1286, 2020.
Artigo em Japonês | MEDLINE | ID: mdl-33342947

RESUMO

In radiological examinations of patients, we often take stacked images and three-dimensional (3D) images of human bone radiological images such as X-ray images and CT images. In general, learning of bone structure using specialized anatomy books is currently performed at medical radiological technologist education facilities. In the anatomy education of the medical school, in order to understand the structure of human and the individual bone shapes in detail, a real human bone specimen is used to gain knowledge of skeleton, bone shape, bone name and bone function. But it is actually difficult for a radiological technologist to obtain such learning opportunities. Therefore, we had to depend on two-dimensional information from an anatomical atlas so far. Therefore, as a method to solve this, we devised this stereo-paired bone anatomical chart by stereoscopic photography of a real human bone specimen that is available only in the anatomy laboratory. In classical anatomy textbooks, there are no figures that enable us to view 3D structures of human bones. Our stereo-paired bone anatomical charts make it possible to observe accurate bone structures three-dimensionally. In addition, we saved the data as a PDF file and uploaded to an internet server so that we can freely download and readily observe 3D images of human bones at all times and all places with a tablet or a PC monitor.


Assuntos
Imageamento Tridimensional , Radiação , Compreensão , Humanos , Aprendizagem , Modelos Anatômicos
5.
Gan To Kagaku Ryoho ; 47(11): 1605-1608, 2020 Nov.
Artigo em Japonês | MEDLINE | ID: mdl-33268737

RESUMO

Severe stenosis rarely occurs with radiation esophagitis after irradiation. We report our recent experience of a case of recurrent breast cancer in which the patient developed severe esophageal stenosis after receiving combined bevacizumab (Bev)-paclitaxel(PTX)therapy following radiotherapy for a thoracic vertebral metastasis. A 59-year-old woman with Stage ⅢB left breast cancer had undergone total mastectomy with axillary lymph node dissection after receiving neoadjuvant therapy. Elevated carcinoembryonic antigen levels were observed 23 months postoperatively, and multiple bone metastases were detected on PET-CT. After 5 sessions of irradiation with 20 Gy at the Th8-L1 level, combined Bev and PTX plus zoledronic acid was administered. The patient developed dysphagia at the end of the 4 cycles of combined Bev and PTX therapy, and her condition exacerbated subsequently. Therefore, upper gastrointestinal endoscopy was performed, which revealed a circumferential stenosis 31-37 cm from the incisors. We decided to perform the endoscopic treatment. After 3 balloon dilatations, her condition improved, and oral ingestion was possible. The esophageal stenosis might have been caused by the exacerbation of esophagitis because of the delayed wound healing effect of Bev in addition to radiation.


Assuntos
Neoplasias da Mama , Estenose Esofágica , Esofagite , Radiação , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Bevacizumab/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/cirurgia , Esofagite/induzido quimicamente , Feminino , Humanos , Mastectomia , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Paclitaxel/efeitos adversos , Pacientes , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons
6.
Kyobu Geka ; 73(13): 1090-1093, 2020 Dec.
Artigo em Japonês | MEDLINE | ID: mdl-33271578

RESUMO

A male patient underwent radiation therapy for hypopharyngeal cancer and esophageal cancer at the age of 58 years without recurrence. At the age of 63 years, he started to experience fatigue, numbness of the left upper limb and dizziness. The symptom gradually worsened and he was admitted to our hospital for further investigation. By computed tomography scan and angiography, the subclavian artery (SCA) occlusion and a patent left vertebral artery with retrograde flow were revealed( subclavian steal syndrome). Subclavian artery occlusion could not be recanalized by percutaneous transluminal angioplasty. He underwent carotid-subclavian bypass. His symptoms clearly improved. Postopertive course was uneventful and no further symptoms developed after surgery.


Assuntos
Arteriopatias Oclusivas , Radiação , Síndrome do Roubo Subclávio , Humanos , Masculino , Recidiva Local de Neoplasia , Artéria Subclávia
7.
Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi ; 38(11): 826-830, 2020 Nov 20.
Artigo em Chinês | MEDLINE | ID: mdl-33287475

RESUMO

Objective: To explore the association between long-term low-dose radiation exposure and other influencing factors with the risk of lens opacity on medical radiation workers. Methods: In July 2019, a retrospective cohort study was conducted by collecting the basic demographic information, dose data and health inspection result of 2708 radiologists in 22 hospitals of Guangzhou from the Occupational Health Inspection Information System and the Personal Dose Monitoring System of the Guangdong Prevention and Treatment Center for Occupational Disease between 2010 to 2018. The association between the average annual effective dose and lens opacity risk was calculated by using Time-Dependent Cox Regression Model. Results: From 2010 to 2018, the incidence density of lens opacity was 185.90/10000 person years. Compared with the radiation workers in the age <30 years group (93.74%) , the 5-year normal rate of lens in the age ≥50 years group (72.51%) was lower (P<0.01) ; Compared with the radiation workers in the exposure age <10 years group (92.69%) , the 5-year normal rate of lens in more than 20 years exposed group (83.05%) was lower (P<0.01) . Multifactor analysis showed that age was an independent influencing factor for lens opacity in medical radiation workers (HR=14.485, P<0.01) . The risk of lens opacification increased by 4.9%, 10.1% and 15.5% in 30-, 40- and 50-years group, respectively. Gender, cigarette, alchol, type of work, length of service and annual effective dose had no significant effect on lens opacity (P>0.05) . Conclusion: Age is the main influencing factor of lens opacification in medical radiation workers, their radiation working time and intensity should be strictly controlled and radiation protection should be done.


Assuntos
Catarata , Cristalino , Exposição Ocupacional , Radiação , Catarata/epidemiologia , Catarata/etiologia , Humanos , Estudos Retrospectivos
8.
PLoS One ; 15(11): e0239321, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33175879

RESUMO

BACKGROUND: Testicular germ cell tumor (TGCT) incidence has increased in recent decades along with the use and dose of diagnostic radiation. Here we examine the association between reported exposure to diagnostic radiation and TGCT risk. METHODS: We conducted a case-control study of men with and without TGCT recruited from hospital- and population-based settings. Participants reported on exposures to 1) x-ray or CT below the waist and 2) lower GI series or barium enema, which consists of a series of x-rays of the colon. We also derived a combined measure of exposure. We used logistic regression to determine the risk of developing TGCT according to categories of exposures (0, 1-2, or ≥3 exposures) and age at first exposure, adjusting for age, year of birth, race, county, body mass index at diagnosis, family history of TGCT, and personal history of cryptorchidism. RESULTS: There were 315 men with TGCT and 931 men without TGCT in our study. Compared to no exposures, risk of TGCT was significantly elevated among those reporting at least three exposures to x-ray or CT (OR≥3 exposures, 1.78; 95% CI, 1.15-2.76; p = 0.010), lower GI series or barium enema (OR≥3 exposures, 4.58; 95% CI, 2.39-8.76; p<0.001), and the combined exposure variable (OR≥3 exposures, 1.59; 95% CI, 1.05-2.42; p = 0.029). The risk of TGCT was elevated for those exposed to diagnostic radiation at age 0-10 years, compared to those first exposed at age 18 years or later, although this association did not reach statistical significance (OR, 2.00; 95% CI, 0.91-4.42; p = 0.086). CONCLUSIONS: Exposure to diagnostic radiation below the waist may increase TGCT risk. If these results are validated, efforts to reduce diagnostic radiation doses to the testes should be prioritized.


Assuntos
Cavidade Abdominal/efeitos da radiação , Diagnóstico por Imagem/efeitos adversos , Neoplasias Embrionárias de Células Germinativas/etiologia , Pelve/efeitos da radiação , Lesões por Radiação/etiologia , Neoplasias Testiculares/etiologia , Adolescente , Adulto , Fatores Etários , Estudos de Casos e Controles , Criança , Pré-Escolar , Criptorquidismo/etiologia , Humanos , Lactente , Recém-Nascido , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Radiação , Fatores de Risco , Testículo/efeitos da radiação , Adulto Jovem
10.
Am J Bot ; 107(11): 1527-1541, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33079383

RESUMO

PREMISE: Plant genome size ranges widely, providing many opportunities to examine how genome size variation affects plant form and function. We analyzed trends in chromosome number, genome size, and leaf traits for the woody angiosperm clade Viburnum to examine the evolutionary associations, functional implications, and possible drivers of genome size. METHODS: Chromosome counts and genome size estimates were mapped onto a Viburnum phylogeny to infer the location and frequency of polyploidization events and trends in genome size evolution. Genome size was analyzed with leaf anatomical and physiological data to evaluate the influence of genome size on plant function. RESULTS: We discovered nine independent polyploidization events, two reductions in base chromosome number, and substantial variation in genome size with a slight trend toward genome size reduction in polyploids. We did not find strong relationships between genome size and the functional and morphological traits that have been highlighted at broader phylogenetic scales. CONCLUSIONS: Polyploidization events were sometimes associated with rapid radiations, demonstrating that polyploid lineages can be highly successful. Relationships between genome size and plant physiological function observed at broad phylogenetic scales may be largely irrelevant to the evolutionary dynamics of genome size at smaller scales. The view that plants readily tolerate changes in ploidy and genome size, and often do so, appears to apply to Viburnum.


Assuntos
Radiação , Viburnum , Evolução Molecular , Tamanho do Genoma , Genoma de Planta , Humanos , Filogenia , Poliploidia
11.
J Food Sci ; 85(11): 4070-4079, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33089532

RESUMO

Piperine, a bioactive alkaloid, is known to have anticancer activities. Hence, in this study, the effectiveness of piperine pretreatment as a strategy for radio-sensitizing colorectal adenocarcinoma cell line (HT-29) was analyzed. For this, HT-29 cells were pretreated with piperine (12.5 and 25 µg/mL) and exposed to γ-radiation (1.25 Gy) and analyzed for various effector pathways to elucidate the possible mode of action in comparison to individual treatments. The proliferation efficiency of the cells was analyzed by trypan blue dye exclusion assay and MTT assay. The synergistic effects of the combination treatment were analyzed with compuSyn software. Downstream signaling pathways leading to apoptosis were studied using flowcytometry, immunofluorescence, and immunoblot assays. It was observed that combination treatment arrested HT-29 cells at G2/M phase nearly 2.8 folds higher than radiation treatment alone, inducing the radio-resistant cells to undergo apoptosis through mitochondria-dependent pathway. In addition, activation of caspase-3 and cleavage of poly(ADP-ribose) polymerases-1, the key molecular events in apoptotic signaling, were significantly enhanced. Activation of estrogen receptor beta (ERß), a nuclear hormone transcription factor promoting tumor suppression represents a novel clinical advance towards management and prevention of cancers. Interestingly, the expression of ERß was increased in the cells treated with piperine. In conclusion, piperine pretreatment enhances radio-sensitization in HT-29 cells by inducing the cells to undergo apoptosis hence, can be used as a classic candidate for colon cancer sensitization towards radiotherapy. PRACTICAL APPLICATION: Piperine induces enhanced radiosensitization of colon cancer cell line (HT-29) by interfering with the cancer cell line proliferation, DNA damage, and apoptosis.


Assuntos
Alcaloides/farmacologia , Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Benzodioxóis/farmacologia , Neoplasias/fisiopatologia , Piperidinas/farmacologia , Alcamidas Poli-Insaturadas/farmacologia , Caspase 3/genética , Caspase 3/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , Células HT29 , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Mitocôndrias/efeitos da radiação , Neoplasias/genética , Neoplasias/metabolismo , Poli(ADP-Ribose) Polimerase-1/genética , Poli(ADP-Ribose) Polimerase-1/metabolismo , Radiação , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/efeitos da radiação
13.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 2602-2605, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018539

RESUMO

Rhythm regularity of the heart depends on how electrical impulses spread through the cardiac conduction system. Any abnormal activities in the electrical impulses can lead to serious cardiac disorders or sudden death. It is important to understand the electrical activities of the human heart in both healthy and diseased conditions to determine the cause of cardiac disorders and explore the best therapeutic designs. Mathematical models calibrated with clinical and/or in-vitro data are popularly used to study cardiac function and investigate treatment effects. Most of the current human heart models are highly integrated and couple over a hundred equations across different organizational scales of ion channel, cell, and muscle. The model complex poses a significant computational challenge on cardiac simulation. This study developed a metamodel to replace the time-consuming simulation model. Specifically, Gaussian Process (GP) is used to reconstruct the spatiotemporal variations of the cell membrane potential in left atrium. Four different covariance functions were used to infer the potential distributions. The GP model provides an accurate estimation of the spatiotemporal propagation of electrical waves with a small set of data and shows great advantage in computations as compared to traditional models.


Assuntos
Eletricidade , Radiação , Fenômenos Eletromagnéticos , Átrios do Coração , Humanos , Distribuição Normal
14.
BMC Oral Health ; 20(1): 242, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32873280

RESUMO

BACKGROUND: Radiotherapy, applied to the head and neck region, can cause radiation side effects such as reduction of saliva and radiation caries. The aim of this study was to perform an in vitro assessment of the effects of radiation therapy on the morphological, mechanical, and chemical properties of primary and permanent teeth. METHODS: One hundred four extracted human teeth (52 impacted wisdom teeth, 52 primary molar teeth) were used. The teeth were divided into two parts in the mesiodistal direction. Of the 98 teeth, the vestibular sections were used for the vickers analysis and lingual sections were used for the Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) analysis. The teeth in the experimental group were fixed to wax models. Each model had an equal number of teeth (n = 7). The doses were applied to the teeth for 6 weeks; 5 week days and 2Gy daily. After the radiotherapy was conducted weekly, a wax model was taken from radiation reception. Along with the elemental contents (Na, K, Mg, P, and Ca) of the teeth, enamel and dentin microhardness was evaluated, and SEM analyzes were performed on 6 teeth. RESULTS: Radiation caused a decrease in microhardness of enamel and dentin (p < 0.05). In the elemental analysis by ICP-OES, it was observed that there were decreases in all elements after 60Gy compared to the control group (p < 0.05). In the experimental groups, amorphous structures were encountered in SEM images. CONCLUSIONS: Radiation has negative effects on the teeth structure and additional studies are needed in this regard. This study indicates that radiotherapy patients are at a higher risk for dental caries.


Assuntos
Cárie Dentária , Radiação , Esmalte Dentário , Dentina , Humanos , Dente Molar , Dente Decíduo
15.
An. Fac. Cienc. Méd. (Asunción) ; 53(2): 165-168, 20200800.
Artigo em Espanhol | LILACS | ID: biblio-1119717

RESUMO

La enteritis por radiación o enteritis actínica es una complicación secundaria al uso de radioterapia para tratamiento de tumores pélvicos, que puede afectar con mayor frecuencia al intestino delgado (principalmente íleon) y al colon. La cirugía en pacientes con enteritis por radiación crónica debe reservarse ante la presencia de complicaciones, ya que está relacionada con una alta morbilidad y estancia hospitalaria prolongadas, así como posibilidad de re operación. Exponemos el caso de una paciente con oclusión intestinal secundaria a enteritis por radiación que desarrolló años después de la conclusión de su tratamiento por cáncer de cuello uterino, con el objetivo de que esta enfermedad sea sospechada en pacientes con antecedentes de radiación.


Radiation enteritis or actinic enteritis is a complication secondary to the use of radiotherapy to treat pelvic tumors, which can more frequently affect the small intestine (mainly ileum) and the colon. Surgery in patients with chronic radiation enteritis should be reserved in the presence of complications, since it is related to high morbidity and prolonged hospital stay, as well as the possibility of reoperation. We present the case of a patient with intestinal occlusion secondary to radiation enteritis who developed years after the conclusion of her treatment due to cervical cancer, with the objective that this disease has to be suspected in patients with history of radiation.


Assuntos
Trato Gastrointestinal/efeitos da radiação , Enterite , Radiação , Radioterapia/efeitos adversos
16.
Am J Physiol Gastrointest Liver Physiol ; 319(3): G412-G419, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32755305

RESUMO

A major component of gastric acid is hydrochloric acid (HCl), which can activate transient receptor potential vanilloid 1 (TRPV1). In the present study, we investigated how sustained laryngeal TRPV1 activation affects the frequency of the swallowing reflex. Experiments were carried out on 85 male Sprague-Dawley rats. The effects of short and sustained application of chemicals (3 µl of 0.1 N HCl or capsaicin) on the frequency of swallowing and on time-dependent changes in the occurrence of swallowing evoked by supralaryngeal nerve stimulation were determined. To evaluate vascular permeability of the larynx, Evans blue dye was intravenously injected after 5 or 60 min of sustained TRPV1 activation. SB366791 (a TRPV1 inhibitor) and Cap/QX-314 (a TRPV1-expressed neuronal inhibitor) significantly inhibited HCl/capsaicin-induced swallowing, but air flow-induced swallowing was not affected. Although the number of air flow-induced swallows followed by capsaicin stimulation was not affected within 5 min, it was significantly reduced by 60-min capsaicin or HCl application. The swallowing threshold associated with supralaryngeal nerve stimulation did not significantly change throughout the recording period. Evans blue dye concentrations in the larynx were significantly higher at 60 min in the 10-5 M capsaicin group than in the control group. Our results suggest that sustained TPRV1 activation not only desensitizes TRPV1 but also inactivates mechanoreceptors, which may be attributed to increases in vascular permeability and edema, as part of an inflammatory process.NEW & NOTEWORTHY Although a transient receptor potential vanilloid 1 (TRPV1) inhibitor or TRPV1-expressed neuronal inhibitor significantly inhibited HCl/capsaicin-evoked swallowing, air flow-induced swallowing was not affected. The number of air flow-induced swallows was significantly reduced within 60 min of TRPV1 activation. Evans blue dye concentration in the larynx increased 60 min after capsaicin application. TPRV1 activation not only desensitizes TRPV1 but also inactivates mechanoreceptors caused by increases in vascular permeability and edema.


Assuntos
Anestesia , Deglutição/efeitos dos fármacos , Laringe/metabolismo , Canais de Cátion TRPV/agonistas , Anilidas/farmacologia , Animais , Permeabilidade Capilar , Capsaicina/farmacologia , Cinamatos/farmacologia , Estimulação Elétrica , Nervos Laríngeos/fisiologia , Masculino , Mecanorreceptores/efeitos dos fármacos , Estimulação Física , Radiação , Ratos , Ratos Sprague-Dawley , Canais de Cátion TRPV/antagonistas & inibidores
19.
Physiol Plant ; 170(3): 357-372, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32639611

RESUMO

Photosynthetically active radiation (PAR) affects transpirational water loss, yet we do not know through which mechanisms root water uptake is adjusted in parallel. Here, we exposed hydroponically grown barley plants to three levels of PAR [Normal (control), Low, High] and focused on the role which aquaporins (AQPs), apoplastic barriers (Casparian bands, suberin lamellae) and root morphology play in the adjustment of root hydraulic conductivity (Lp). Plants were analyzed when they were 14-18 days (d) old. Root and cell Lp, which involves AQP activity, was determined through exudation and cell pressure probe measurements, respectively. Gene expression of AQPs was analyzed through qPCR. The formation of apoplastic barriers was studied through staining of cross-sections. The rate of transpirational water loss per plant and unit leaf area increased in response to high-PAR and decreased in response to low-PAR treatments, both during day and night. Hydraulic conductivity in roots decreased significantly at organ and cell level in response to Low-PAR, and increased (organ) or did not change (cell level) in response to High-PAR. The formation of apoplastic barriers was little affected by PAR. Gene expression of AQPs tended to be highest in the Low-PAR treatment. Lateral roots, showing few apoplastic barriers, contributed the least in Low- and the most to root surface area in High-PAR plants. It is concluded that barley plants which experience changes in shoot transpirational water loss in response to PAR adjust root water uptake through changes in root Lp, and that these changes are mediated through altered AQP activity and root morphology.


Assuntos
Aquaporinas , Radiação , Aquaporinas/genética , Aquaporinas/metabolismo , Transporte Biológico , Hordeum/genética , Hordeum/metabolismo , Raízes de Plantas/metabolismo , Água/metabolismo
20.
World Neurosurg ; 141: 318-322, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32592964

RESUMO

BACKGROUND: Radiation-induced spinal cord cavernous malformations (CMs) are rare pathologies compared with radiation-induced cerebral CMs. We present a case of a radiation-induced spinal cord CM developed 31 years after radiation therapy for medulloblastoma. CASE DESCRIPTION: A 37-year-old man developed a symptomatic spinal hemorrhagic lesion 31 years after radiation therapy for medulloblastoma. Magnetic resonance imaging revealed an intramedullary cystic lesion with a fluid-fluid level in the C7 area. Surgery was performed leading to an unclear diagnosis. Two years later, the patient had a relapse and underwent a second operation, allowing a definitive diagnosis of radiation-induced spinal cord CM. This is believed to be the second case of de novo intramedullary CM formation following spinal radiation therapy for medulloblastoma. CONCLUSIONS: Radiation-induced spinal cord CMs should be recognized as a possible late adverse effect in patients treated with radiation therapy for medulloblastoma.


Assuntos
Malformações Arteriovenosas/cirurgia , Neoplasias Cerebelares/cirurgia , Meduloblastoma/patologia , Recidiva Local de Neoplasia/patologia , Radiação , Adulto , Malformações Arteriovenosas/diagnóstico , Malformações Arteriovenosas/patologia , Neoplasias Cerebelares/diagnóstico , Neoplasias Cerebelares/patologia , Humanos , Masculino , Meduloblastoma/complicações , Meduloblastoma/cirurgia , Recidiva Local de Neoplasia/cirurgia , Neoplasias da Medula Espinal/diagnóstico , Neoplasias da Medula Espinal/etiologia , Neoplasias da Medula Espinal/cirurgia
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