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1.
Br J Surg ; 108(2): 168-173, 2021 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-33711128

RESUMO

BACKGROUND: Although patients with schizophrenia have a higher risk of developing breast cancer than the general population, studies that have investigated postoperative complications after breast cancer surgery in patients with schizophrenia are scarce. This study examined associations between schizophrenia and short-term outcomes following breast cancer surgery. METHODS: Patients who underwent surgery for stage 0-III breast cancer between July 2010 and March 2017 were identified from a Japanese nationwide inpatient database. Multivariable analyses were conducted to compare postoperative complications and hospitalization costs between patients with schizophrenia and those without any psychiatric disorder. Three sensitivity analyses were performed: a 1 : 4 matched-pair cohort analysis with matching for age, institution, and fiscal year at admission; analyses excluding patients with schizophrenia who were not taking antipsychotic medication; and analyses excluding patients with schizophrenia who were admitted to hospital involuntarily. RESULTS: The study included 3660 patients with schizophrenia and 350 860 without any psychiatric disorder. Patients with schizophrenia had a higher in-hospital morbidity (odds ratio (OR) 1.37, 95 per cent c.i. 1.21 to 1.55), with more postoperative bleeding (OR 1.34, 1.05 to 1.71) surgical-site infections (OR 1.22, 1.04 to 1.43), and sepsis (OR 1.20, 1.03 to 1.41). The total cost of hospitalization (coefficient €743, 95 per cent c.i. 680 to 806) was higher than that for patients without any psychiatric disorder. All sensitivity analyses showed similar results to the main analyses. CONCLUSION: Although causal inferences remain premature, multivariable regression analyses showed that schizophrenia was associated with greater in-hospital morbidity and higher total cost of hospitalization after breast cancer surgery than in the general population.


Assuntos
Neoplasias da Mama/complicações , Esquizofrenia/complicações , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/cirurgia , Feminino , Humanos , Japão , Pessoa de Meia-Idade , Análise Multivariada , Resultado do Tratamento , Adulto Jovem
2.
Br J Surg ; 108(2): 205-213, 2021 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-33711144

RESUMO

BACKGROUND: In patients with rectal cancer, enlarged lateral lymph nodes (LLNs) result in increased lateral local recurrence (LLR) and lower cancer-specific survival (CSS) rates, which can be improved with (chemo)radiotherapy ((C)RT) and LLN dissection (LLND). This study investigated whether different LLN locations affect oncological outcomes. METHODS: Patients with low cT3-4 rectal cancer without synchronous distant metastases were included in this multicentre retrospective cohort study. All MRI was re-evaluated, with special attention to LLN involvement and response. RESULTS: More advanced cT and cN category were associated with the occurrence of enlarged obturator nodes. Multivariable analyses showed that a node in the internal iliac compartment with a short-axis (SA) size of at least 7 mm on baseline MRI and over 4 mm after (C)RT was predictive of LLR, compared with a post-(C)RT SA of 4 mm or less (hazard ratio (HR) 5.74, 95 per cent c.i. 2.98 to 11.05 vs HR 1.40, 0.19 to 10.20; P < 0.001). Obturator LLNs with a SA larger than 6 mm after (C)RT were associated with a higher 5-year distant metastasis rate and lowered CSS in patients who did not undergo LLND. The survival difference was not present after LLND. Multivariable analyses found that only cT category (HR 2.22, 1.07 to 4.64; P = 0.033) and margin involvement (HR 2.95, 1.18 to 7.37; P = 0.021) independently predicted the development of metastatic disease. CONCLUSION: Internal iliac LLN enlargement is associated with an increased LLR rate, whereas obturator nodes are associated with more advanced disease with increased distant metastasis and reduced CSS rates. LLND improves local control in persistent internal iliac nodes, and might have a role in controlling systemic spread in persistent obturator nodes.Members of the Lateral Node Study Consortium are co-authors of this study and are listed under the heading Collaborators.


Assuntos
Metástase Linfática/patologia , Neoplasias Retais/patologia , Idoso , Feminino , Humanos , Excisão de Linfonodo/mortalidade , Linfonodos/patologia , Metástase Linfática/diagnóstico por imagem , Metástase Linfática/terapia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Pelve , Neoplasias Retais/mortalidade , Neoplasias Retais/cirurgia , Estudos Retrospectivos , Análise de Sobrevida
3.
Br J Surg ; 104(2): e158-e164, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28121044

RESUMO

BACKGROUND: Open total gastrectomy carries a high risk of surgical-site infection (SSI). This study evaluated the non-inferiority of antimicrobial prophylaxis for 24 compared with 72 h after open total gastrectomy. METHODS: An open-label, randomized, non-inferiority study was conducted at 57 institutions in Japan. Eligible patients were those who underwent open total gastrectomy for gastric cancer. Patients were assigned randomly to continued use of ß-lactamase inhibitor for either 24 or 72 h after surgery. The primary endpoint was the incidence of SSI, with non-inferiority based on a margin of 9 percentage points and a 90 per cent c.i. The secondary endpoint was the incidence of remote infection. RESULTS: A total of 464 patients (24 h prophylaxis, 228; 72 h prophylaxis, 236) were analysed. SSI occurred in 20 patients (8·8 per cent) in the 24-h prophylaxis group and 26 (11·0 per cent) in the 72-h group (absolute difference -2·2 (90 per cent c.i. -6·8 to 2·4) per cent; P < 0·001 for non-inferiority). However, the incidence of remote infection was significantly higher in the 24-h prophylaxis group. CONCLUSION: Antimicrobial prophylaxis for 24 h after total gastrectomy is not inferior to 72 h prophylaxis for prevention of SSI. Shortened antimicrobial prophylaxis might increase the incidence of remote infection. Registration number: UMIN000001062 ( http://www.umin.ac.jp).


Assuntos
Antibioticoprofilaxia , Gastrectomia , Neoplasias Gástricas/cirurgia , Infecção da Ferida Cirúrgica/prevenção & controle , Idoso , Ampicilina/administração & dosagem , Esquema de Medicação , Feminino , Humanos , Japão/epidemiologia , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Infecções Respiratórias/epidemiologia , Sulbactam/administração & dosagem , Infecção da Ferida Cirúrgica/epidemiologia , Inibidores de beta-Lactamases/administração & dosagem
4.
Br J Surg ; 103(12): 1608-1615, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27550722

RESUMO

BACKGROUND: The use of oral prophylactic antibiotics for the prevention of surgical-site infection (SSI) in patients undergoing laparoscopic surgery for colorectal cancer is controversial. The aim of this RCT was to evaluate whether intravenous perioperative antibiotics are inferior to combined preoperative oral and perioperative intravenous antibiotics in this setting. METHODS: Patients undergoing elective laparoscopic colorectal resection in a single cancer centre were assigned randomly to combined preoperative oral antibiotics (metronidazole and kanamycin) and perioperative intravenous antibiotics (cefmetazole) (oral/IV group) or to perioperative intravenous antibiotics (cefmetazole) alone (IV-only group). Patients were stratified for the analyses based on type of operation (colonic surgery, anterior resection or abdominoperineal resection), preoperative use of mechanical bowel preparation, preoperative chemoradiotherapy and the presence of diabetes mellitus. The primary endpoint was the overall rate of SSI. Secondary endpoints were the rates of incisional site infection, organ/space infection, anastomotic leakage, intra-abdominal abscess, adverse events and postoperative complications. RESULTS: Of 540 patients offered participation in the trial in 2013-2014, 515 agreed to take part and were randomized. Some 256 patients in the IV-only group and 255 in the oral/IV group completed the treatment per protocol. The overall rate of SSI was 7·8 per cent (20 of 256) in the IV-only group and 7·8 per cent (20 of 255) in the oral/IV group, confirming that perioperative administration of intravenous antibiotics alone was not inferior to the combined regimen (P = 0·017). There were no differences in rates of incisional site infection (5·5 versus 5·9 per cent respectively), organ/space infection (2·3 versus 2·0 per cent) or other secondary endpoints between the two groups. CONCLUSION: Intravenous perioperative antimicrobial prophylaxis alone is not inferior to combined preoperative oral and intravenous perioperative prophylaxis with regard to SSI in patients with colorectal cancer undergoing elective laparoscopic resection. Registration number: UMIN000019339 ( http://www.umin.ac.jp/ctr/).


Assuntos
Antibacterianos/administração & dosagem , Antibioticoprofilaxia/métodos , Neoplasias Colorretais/cirurgia , Laparoscopia/métodos , Infecção da Ferida Cirúrgica/prevenção & controle , Administração Oral , Adulto , Idoso , Idoso de 80 Anos ou mais , Fístula Anastomótica/etiologia , Cefmetazol/administração & dosagem , Colectomia/métodos , Quimioterapia Combinada , Feminino , Humanos , Infusões Intravenosas , Cuidados Intraoperatórios/métodos , Canamicina/administração & dosagem , Laparoscopia/efeitos adversos , Masculino , Metronidazol/administração & dosagem , Pessoa de Meia-Idade , Complicações Pós-Operatórias/etiologia , Cuidados Pré-Operatórios/métodos
7.
Colorectal Dis ; 17(10): O213-6, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26277783

RESUMO

AIM: The lateral pelvic lymph nodes are one of the major sites and sources of local recurrence (LR) after surgery for rectal cancer. Salvage lateral pelvic lymph node dissection (LPLD) is potentially curative, but the value of laparoscopic surgery in such cases is unknown. Our aim was to report the technical details of laparoscopic salvage LPLD for LR at these nodes after rectal cancer surgery. METHOD: The study was based on nine patients who underwent laparoscopic salvage LPLD for LR at the lateral pelvic lymph nodes after surgery for rectal cancer. The safety and feasibility of this procedure were determined. RESULTS: The median operation time was 381 min and the median estimated blood loss was 130 ml. There were no conversions. Adjacent structures removed en bloc were the pelvic plexus in four patients, the internal iliac artery in seven patients and the seminal vesicle in one patient. The median number of metastatic lymph nodes was 1 (range 1-11). CONCLUSION: Our novel technique of laparoscopic salvage LPLD for LR at the lateral pelvic lymph nodes is safe and feasible.


Assuntos
Laparoscopia/métodos , Excisão de Linfonodo/métodos , Linfonodos/cirurgia , Recidiva Local de Neoplasia/cirurgia , Neoplasias Retais/cirurgia , Terapia de Salvação , Idoso , Estudos de Coortes , Feminino , Seguimentos , Humanos , Linfonodos/patologia , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/mortalidade , Recidiva Local de Neoplasia/patologia , Pelve , Neoplasias Retais/patologia , Estudos Retrospectivos , Medição de Risco , Taxa de Sobrevida , Resultado do Tratamento
9.
Environ Sci Technol ; 47(12): 6368-76, 2013 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-23668636

RESUMO

We employed embryos of the zebrafish, Danio rerio, for our studies on the in vivo bystander effect between embryos irradiated with high-dose X-rays and naive unirradiated embryos. The effects on the naive whole embryos were studied through quantification of apoptotic signals at 25 h post fertilization (hpf) through the terminal dUTP transferase-mediated nick end-labeling (TUNEL) assay followed by counting the stained cells under a microscope. We report data showing that embryos at 5 hpf subjected to a 4-Gy X-ray irradiation could release a stress signal into the medium, which could induce a bystander effect in partnered naive embryos sharing the same medium. We further demonstrated that this bystander effect (induced through partnering) could be successfully suppressed through the addition of the nitric oxide (NO) scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO) into the medium but not through the addition of the CO liberator tricarbonylchloro(glycinato)ruthenium(II) (CORM-3). This shows that NO was involved in the bystander response between zebrafish embryos induced through X-ray irradiation. We also report data showing that the bystander effect could be successfully induced in naive embryos by introducing them into the irradiated embryo conditioned medium (IECM) alone, i.e., without partnering with the irradiated embryos. The IECM was harvested from the medium that had conditioned the zebrafish embryos irradiated at 5 hpf with 4-Gy X-ray until the irradiated embryos developed into 29 hpf. NO released from the irradiated embryos was unlikely to be involved in the bystander effect induced through the IECM because of the short life of NO. We further revealed that this bystander effect (induced through IECM) was rapidly abolished through diluting the IECM by a factor of 2× or greater, which agreed with the proposal that the bystander effect was an on/off response with a threshold.


Assuntos
Efeito Espectador/efeitos da radiação , Raios X/efeitos adversos , Animais , Benzoatos/farmacologia , Efeito Espectador/efeitos dos fármacos , Imidazóis/farmacologia , Marcação In Situ das Extremidades Cortadas , Óxido Nítrico/metabolismo , Compostos Organometálicos/farmacologia , Peixe-Zebra
10.
J Mater Sci Mater Med ; 24(2): 437-45, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23160913

RESUMO

Hydroxyapatite (HA) is a synthetic biomaterial and has been found to promote new bone formation when implanted in a bone defect site. However, its use is often limited due to its slow osteointegration rate and low antibacterial activity, particularly where HA has to be used for long term biomedical applications. This work will describe the synthesis and detailed characterization of zinc-substituted HA (ZnHA) as an alternative biomaterial to HA. ZnHA containing 1.6 wt% Zn was synthesized via a co-precipitation reaction between calcium hydroxide, orthophosphoric acid and zinc nitrate hexahydrate. Single-phase ZnHA particles with a rod-like morphology measuring ~50 nm in length and ~15 nm in width, were obtained and characterized using transmission electron microscopy and X-ray diffraction. The substitution of Zn into HA resulted in a decrease in both the a- and c-axes of the unit cell parameters, thereby causing the HA crystal structure to alter. In vitro cell culture work showed that ZnHA possessed enhanced bioactivity since an increase in the growth of human adipose-derived mesenchymal stem cells along with the bone cell differentiation markers, were observed. In addition, antibacterial work demonstrated that ZnHA exhibited antimicrobial capability since there was a significant decrease in the number of viable Staphylococcus aureus bacteria after in contact with ZnHA.


Assuntos
Antibacterianos , Materiais Biocompatíveis/farmacologia , Durapatita/química , Zinco/química , Antibacterianos/síntese química , Antibacterianos/química , Antibacterianos/farmacologia , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/química , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Fenômenos Químicos/efeitos dos fármacos , Durapatita/síntese química , Durapatita/farmacologia , Humanos , Teste de Materiais , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/fisiologia , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus aureus/fisiologia
11.
Eur J Surg Oncol ; 48(11): 2315-2322, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-34802862

RESUMO

Half of the local regional recurrences from rectal cancer are nowadays located in the lateral compartments, most likely due to lateral lymph node (LLN) metastases. There is evidence that a lateral lymph node dissection (LLND) can lower the lateral local recurrence rate. An LLND without neoadjuvant (chemo)radiotherapy in patients with or without suspected LLN metastases has been the standard of care in the East, while Western surgeons believed LLN metastases to be cured by neoadjuvant treatment and total mesorectal excision (TME) only. An LLND in patients without enlarged LLNs might result in overtreatment with low rates of pathological LLNs, but in patients with enlarged LLNs who are treated with (C)RT and TME only, the risk of a lateral local recurrence significantly increases to 20%. Certain Eastern and Western centers are increasingly performing a selective LLND after neoadjuvant treatment in the presence of suspicious LLNs due to new scientific insights, but (inter)national consensus on the indication and surgical approach of LLND is lacking. An LLND is an anatomically challenging procedure with intraoperative risks such as bleeding and postoperative morbidity. It is therefore essential to carefully select the patients who will benefit from this procedure and where possible to perform the LLND in a minimally invasive manner to limit these risks. This review gives an overview of the current evidence of the assessment of LLNs, the indications for LLND, the surgical technique, pitfalls in performing this procedure and the future studies are discussed, aiming to contribute to more (inter)national consensus.


Assuntos
Recidiva Local de Neoplasia , Neoplasias Retais , Humanos , Recidiva Local de Neoplasia/patologia , Neoplasias Retais/cirurgia , Neoplasias Retais/patologia , Excisão de Linfonodo/métodos , Linfonodos/cirurgia , Linfonodos/patologia , Terapia Neoadjuvante/métodos , Metástase Linfática/patologia , Estudos Retrospectivos , Estadiamento de Neoplasias
12.
Phys Rev Lett ; 107(26): 266402, 2011 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-22243170

RESUMO

Synchrotron x-ray diffraction experiment shows that the metal-insulator transition occurring in a ferromagnetic state of a hollandite K(2)Cr(8)O(16) is accompanied by a structural distortion from the tetragonal I4/m to monoclinic P112(1)/a phase with a √2×√2×1 supercell. Detailed electronic structure calculations demonstrate that the metal-insulator transition is caused by a Peierls instability in the quasi-one-dimensional column structure made of four coupled Cr-O chains running in the c direction, leading to the formation of tetramers of Cr ions below the transition temperature. This provides a rare example of the Peierls transition of fully spin-polarized electron systems.

13.
Cephalalgia ; 30(4): 496-9, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19515123

RESUMO

Patients with severe primary headache may benefit from consultation with headache specialists, but doctor attendance rates in Japan are very low. More headache patients might consult headache specialists if these specialists were more widely recognized by the public. To determine what information prompted patients to seek consultation with a headache specialist, we questioned 256 primary headache patients about the source of the helpful information concerning consultation with headache specialists. From 191 patients, a total of 235 responses to the questionnaire were obtained. The most common response was 'websites' (33.2%), followed by 'professionals' (23.8%), 'acquaintances' (20.9%), 'print media' (6.8%) and 'TV/radio' (3.4%). Patients who indicated websites showed the most severe pain and highest impact of headache, and accounted for 52.4% of those with cluster headaches. Development of websites concerning headache specialists would seem likely to increase doctor attendance rates for patients with primary headache.


Assuntos
Cefaleia Histamínica/terapia , Transtornos da Cefaleia Primários/terapia , Internet/estatística & dados numéricos , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Educação de Pacientes como Assunto/estatística & dados numéricos , Encaminhamento e Consulta/estatística & dados numéricos , Adulto , Povo Asiático/estatística & dados numéricos , Cefaleia Histamínica/etnologia , Feminino , Transtornos da Cefaleia Primários/etnologia , Humanos , Disseminação de Informação , Japão/epidemiologia , Masculino , Meios de Comunicação de Massa/estatística & dados numéricos , Pessoa de Meia-Idade , Neurologia/estatística & dados numéricos , Satisfação do Paciente , Inquéritos e Questionários , Adulto Jovem
14.
Kyobu Geka ; 63(8 Suppl): 612-7, 2010 Jul.
Artigo em Japonês | MEDLINE | ID: mdl-20715427

RESUMO

Diagnosis and treatment of pericardial effusion need to be performed frequently by pericardiocentesis or surgical pericardiotomy. Large retention of the effusion is treated conventionally by percutaneous blind puncture, while possible injuries to the myocardium are avoided feasibly by ultrasonically-guided puncture even in case that the effusion remains moderately or unevenly inside the pericardial space. Along with the puncture, drainage tube introduced into the pericardial sac using coaxial method contributes to relieving coexistent pericardial or chronic exudation. The pericardium is also surgically approached traditionally via parasternal, subxiphoid, or lateral-thoracic route. Specimen of the pericardium is optionally sampled to promote analyzing the pathogenesis, and drainage tubes of larger diameter facilitate evacuating the purulent substance in the settings of infectious origins. The lateral thoracotomy is occasionally applied to the effusion around the posterior aspect of the heart, which is preferably replaced by less-invasive video-assisted procedure. Those several measures would facilitate the treatment for pericardial effusion.


Assuntos
Pericardiocentese/métodos , Drenagem/métodos , Humanos , Derrame Pericárdico/cirurgia
15.
J Cell Biol ; 37(2): 231-43, 1968 May.
Artigo em Inglês | MEDLINE | ID: mdl-4385346

RESUMO

In hepatocytes of fetal rats, cytoplasmic organelles identifiable as microbodies appeared, although only a few of them showed nucleoids and most of them generally had an electronlucent appearance due to the low density of their matrices. Some of these microbodies, especially those lacking the nucleoid, showed a substantial connection with granular endoplasmic reticulum (ER), suggesting that microbodies might be formed from granular ER. Agranular tubular profiles projecting from the surface of microbodies were found with a high frequency in fetal and neonatal rats; however, this phenomenon may not provide crucial evidence suggestive of the derivation of microbodies from agranular ER. Growth and maturation of microbodies are considered to be brought about by an enlargement of these organelles, an increase in their matrices, an appearance and enlargement of the nucleoids, and an increase in the enzyme involved. The specific activity of urate oxidase in the isolated nucleoid fraction was significantly lower in the earlier stages of postnatal growth than later. Increases in the enzyme activity per nucleoid (maturation of the nucleoid), in the number of microbodies containing nucleoids (formation of the nucleoid), and in the size of nucleoids (growth of the nucleoid), may contribute to increases in the enzyme activity of the tissues.


Assuntos
Citoplasma , Desenvolvimento Embrionário e Fetal , Crescimento , Fígado/citologia , Animais , Animais Recém-Nascidos , Catalase/metabolismo , Núcleo Celular , D-Aminoácido Oxidase/metabolismo , Retículo Endoplasmático , Feminino , Fígado/enzimologia , Microscopia Eletrônica , Morfogênese , Gravidez , Ratos , Urato Oxidase/metabolismo
16.
Science ; 172(3982): 483-4, 1971 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-5550503

RESUMO

Electrical stimulation of crossed olivocochlear bandles resulted in increase of the positive summating potential in response to high-frequency tone bursts when the summating potential was recorded in the basal turn of the cochlea in anesthetized and immobilized guinea pigs. Strychnine locally applied suppressed the changes of the summating potential.


Assuntos
Cóclea/fisiologia , Estimulação Elétrica , Potenciais Evocados , Núcleo Olivar/fisiologia , Som , Potenciais de Ação , Animais , Vias Auditivas/fisiologia , Depressão Química , Cobaias , Vias Neurais/fisiologia , Estricnina/farmacologia
18.
J Phys Condens Matter ; 21(12): 124211, 2009 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-21817453

RESUMO

An x-ray magnetic circular dichroism study of a polycrystalline Co/CoO bilayer is presented. Using both the chemical specificity and surface sensitivity in the core level techniques, we find that uncompensated Co(2+) spin moments participate in the remanent ferromagnetic response of the bilayer that has oxygen nearest neighbors. These are likely located at the Co/CoO interface. As intermixing of magnetic species is not present in Co/CoO, it is concluded that the observed interface moments are due to interface roughness. Given their direction, these moments appear to not directly correlate to the exchange bias in these bilayers.

19.
Radiat Prot Dosimetry ; 183(1-2): 219-222, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30566666

RESUMO

It is believed that the dose-rate of radiation will have an influence on cell sensitivity. The dose-rate effects on cell survival can be expressed by the change of the ß term in the linear quadratic model. The value at a high-dose-rate decreases below 60 Gy/h and reaches zero at 0.2 Gy/h or less for photons. However, the effect for a high-LET ion-beam is not well known. At HIMAC, cells were exposed to 70 keV/µm carbon-ion beams at different dose-rates between 0.5 and 600 Gy/h at room temperature. The ß values for all survival curves show no significant differences among the dose-rates tested for HSG, V79 and CHO cells. Changing the ion-beam dose-rate had no effect on cell survival. This suggests that high-LET particle beams, such as galactic cosmic rays, may not exhibit a dose-rate effect on cell survival. Low-dose-rate radiation showed an effect similar to high-dose-rate radiation.


Assuntos
Sobrevivência Celular/efeitos da radiação , Células Cultivadas/efeitos da radiação , Transferência Linear de Energia , Animais , Carbono , Radiação Cósmica , Cricetinae , Relação Dose-Resposta à Radiação , Humanos , Íons
20.
Radiat Prot Dosimetry ; 183(1-2): 242-246, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30521045

RESUMO

Uranium is renowned as a global contaminant, and attracts major concern with regards to the health risks involved because its nephrotoxicity. This paper discusses the development of a simple method to identify accumulated regions or localized sites of uranium within kidneys using the CR-39 plastic nuclear track detector. To demonstrate the proposed method, renal cryo-sections (5 µm-t) from Wistar male rats, subcutaneously administered with uranyl acetate (2 mg/kg), were prepared on day one after administration. Concerned sections were subsequently placed on CR-39, stored for 1.25 years, and then etched in a 7 M NaOH solution at 70°C for 3 h. α-tracks were then detected in the form of etch pits, corresponding to uranium, and also the tissue shape and structure were transferred as a roughness on the surface of CR-39. As observed, the proposed method served to facilitate simultaneous detection and identification of localized regions of uranium accumulation within kidneys.


Assuntos
Rim/efeitos da radiação , Radiometria/métodos , Urânio/toxicidade , Animais , Masculino , Compostos Organometálicos , Polietilenoglicóis , Ratos , Ratos Wistar
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