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1.
Tech Coloproctol ; 27(12): 1387-1392, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37358669

RESUMO

PURPOSE: Stoma site marking is an important preoperative intervention for preventing various stoma-associated complications. In our institution, standardized stoma site marking is routinely performed before rectal cancer surgery with stoma creation, and various stoma-associated factors are recorded in the ostomy-record template. The present study investigated risk factors for stoma leakage. METHODS: Our stoma site marking is standardized so that it can be performed by non-stoma specialists. To identify risk factors of stoma leakage at 3 months after surgery, various preoperative factors associated with stoma site marking in our ostomy-record template were retrospectively analyzed in 519 patients who underwent rectal cancer surgery with stoma creation from 2015 to 2020. RESULTS: Stoma leakage was seen in 35 of the 519 patients (6.7%). The distance between the stoma site marking and the umbilicus was less than 60 mm in 27 of the 35 patients (77%) who experienced stoma leakage, so a distance of less than 60 mm was identified as an independent risk factor for stoma leakage. Aside from preoperative factors, stoma leakage was also caused by postoperative skin wrinkles or surgical scars near the stoma site in 8 of 35 patients (23%). CONCLUSION: Preoperative standardized stoma site marking is necessary to achieve reliable marking that is easy to perform. To reduce the risk of stoma leakage, a distance of 60 mm or more between the stoma site marking and the umbilicus is ideal, and surgeons need to contrive ways to keep surgical scars away from the stoma site.


Assuntos
Laparoscopia , Neoplasias Retais , Procedimentos Cirúrgicos Robóticos , Estomas Cirúrgicos , Humanos , Estudos Retrospectivos , Cicatriz , Estomas Cirúrgicos/efeitos adversos , Laparoscopia/efeitos adversos , Neoplasias Retais/cirurgia , Padrões de Referência
2.
J Dairy Sci ; 106(10): 6710-6722, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37211485

RESUMO

Yogurt is made by fermenting milk with 2 lactic acid bacteria, Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus. To comprehensively understand the protocooperation mechanism between S. thermophilus and L. bulgaricus in yogurt fermentation, we examined 24 combinations of cocultures comprising 7 fast- or slow-acidifying S. thermophilus strains with 6 fast- or slow-acidifying L. bulgaricus strains. Furthermore, 3 NADH oxidase (Nox)-deficient mutants (Δnox) and one pyruvate formate-lyase deficient mutant (ΔpflB) of S. thermophilus were used to evaluate the factor that determines the acidification rate of S. thermophilus. The results revealed that the acidification rate of S. thermophilus monoculture determined the yogurt fermentation rates, despite the coexistence of L. bulgaricus, whose acidification rate was either fast or slow. Significant correlation was found between the acidification rate of S. thermophilus monoculture and the amount of formate production. Result using ΔpflB showed that the formate was indispensable for the acidification of S. thermophilus. Moreover, results of the Δnox experiments revealed that formate production required Nox activity, which not only regulated dissolved oxygen, but also the redox potential. The Nox provided the large decrease in redox potential required by pyruvate formate-lyase to produce formate. A highly significant correlation was found between formate accumulation and Nox activity in S. thermophilus. In conclusion, the formate production ability provided by the action of Nox activity determines the acidification rate of S. thermophilus, and consequently, regulates yogurt coculture fermentation.


Assuntos
Lactobacillus delbrueckii , Iogurte , Animais , Iogurte/microbiologia , Streptococcus thermophilus/fisiologia , NAD , Oxirredutases , Fermentação , Formiatos , Concentração de Íons de Hidrogênio
5.
Clin Exp Immunol ; 198(3): 416-429, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31429073

RESUMO

Tumor necrosis factor (TNF) receptor-associated periodic syndrome (TRAPS) is an autoinflammatory disease that is caused by heterozygous mutations in the TNFRSF1A gene. Although more than 150 TNFRSF1A mutations have been reported to be associated with TRAPS phenotypes only a few, such as p.Thr79Met (T79M) and cysteine mutations, have been functionally analyzed. We identified two TRAPS patients in one family harboring a novel p.Gly87Val (G87V) mutation in addition to a p.Thr90Ile (T90I) mutation in TNFRSF1A. In this study, we examined the functional features of this novel G87V mutation. In-vitro analyses using mutant TNF receptor 1 (TNF-R1)-over-expressing cells demonstrated that this mutation alters the expression and function of TNF-R1 similar to that with the previously identified pathogenic T79M mutation. Specifically, cell surface expression of the mutant TNF-R1 in transfected cells was inhibited with both G87V and T79M mutations, whereas the T90I mutation did not affect this. Moreover, peripheral blood mononuclear cells (PBMCs) from TRAPS patients harboring the G87V and T90I mutations showed increased mitochondrial reactive oxygen species (ROS). Furthermore, the effect of various Toll-like receptor (TLR) ligands on inflammatory responses was explored, revealing that PBMCs from TRAPS patients are hyper-responsive to TLR-2 and TLR-4 ligands and that interleukin (IL)-8 and granulocyte-macrophage colony-stimulating factor (GM-CSF) are likely to be involved in the pathogenesis of TRAPS. These findings suggest that the newly identified G87V mutation is one of the causative mutations of TRAPS. Our findings based on unique TRAPS-associated mutations provide novel insight for clearer understanding of inflammatory responses, which would be basic findings of developing a new therapeutic and prophylactic approach to TRAPS.


Assuntos
Febre/genética , Predisposição Genética para Doença/genética , Doenças Hereditárias Autoinflamatórias/genética , Mutação de Sentido Incorreto , Receptores Tipo I de Fatores de Necrose Tumoral/genética , Adulto , Idoso , Sequência de Aminoácidos , Sequência de Bases , Análise Mutacional de DNA/métodos , Feminino , Febre/diagnóstico , Doenças Hereditárias Autoinflamatórias/diagnóstico , Humanos , Masculino , Linhagem , Homologia de Sequência de Aminoácidos
7.
Diabet Med ; 34(4): 586-589, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-27859559

RESUMO

AIM: To examine the contribution of the FUT2 gene and ABO blood type to the development of Type 1 diabetes in Japanese children. METHODS: We analysed FUT2 variants and ABO genotypes in a total of 531 Japanese children diagnosed with Type 1 diabetes and 448 control subjects. The possible association of FUT2 variants and ABO genotypes with the onset of Type 1 diabetes was statistically examined. RESULTS: The se2 genotype (c.385A>T) of the FUT2 gene was found to confer susceptibility to Type 1A diabetes in a recessive effects model [odds ratio for se2/se2, 1.68 (95% CI 1.20-2.35); corrected P value = 0.0075]. CONCLUSIONS: The FUT2 gene contributed to the development of Type 1 diabetes in the present cohort of Japanese children.


Assuntos
Diabetes Mellitus Tipo 1/genética , Fucosiltransferases/genética , Sistema ABO de Grupos Sanguíneos/genética , Povo Asiático/genética , Estudos de Casos e Controles , Predisposição Genética para Doença , Humanos , Japão , Galactosídeo 2-alfa-L-Fucosiltransferase
8.
Diabet Med ; 33(12): 1717-1722, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27352912

RESUMO

AIMS: The aim of this study was to clarify the significance of previously reported susceptibility variants in the development of autoimmune Type 1 diabetes in non-white children. Tested variants included rs2290400, which has been linked to Type 1 diabetes only in one study on white people. Haplotypes at 17q12-q21 encompassing rs2290400 are known to determine the susceptibility of early-onset asthma by affecting the expression of flanking genes. METHODS: We genotyped 63 variants in 428 Japanese people with childhood-onset autoimmune Type 1 diabetes and 457 individuals without diabetes. Possible association between variants and age at diabetes onset was examined using age-specific quantitative trait locus analysis and ordered-subset regression analysis. RESULTS: Ten variants, including rs2290400 in GSDMB, were more frequent among the people with Type 1 diabetes than those without diabetes. Of these, rs689 in INS and rs231775 in CTLA4 yielded particularly high odds ratios of 5.58 (corrected P value 0.001; 95% CI 2.15-14.47) and 1.64 (corrected P value 5.3 × 10-5 ; 95% CI 1.34-2.01), respectively. Age-specific effects on diabetes susceptibility were suggested for rs2290400; heterozygosity of the risk alleles was associated with relatively early onset of diabetes, and the allele was linked to the phenotype exclusively in the subgroup of age at onset ≤ 5.0 years. CONCLUSIONS: The results indicate that rs2290400 in GSDMB and polymorphisms in INS and CTLA4 are associated with the risk of Type 1 diabetes in Japanese children. Importantly, cis-regulatory haplotypes at 17q12-q21 encompassing rs2290400 probably determine the risk of autoimmune Type 1 diabetes predominantly in early childhood.


Assuntos
Cromossomos Humanos Par 17/genética , Diabetes Mellitus Tipo 1/genética , Haplótipos/genética , Polimorfismo de Nucleotídeo Único/genética , Adolescente , Adulto , Idade de Início , Idoso , Alelos , Criança , Pré-Escolar , Feminino , Frequência do Gene/genética , Predisposição Genética para Doença/genética , Humanos , Lactente , Japão/etnologia , Masculino , Pessoa de Meia-Idade , Adulto Jovem
9.
Clin Genet ; 88(3): 261-6, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25171146

RESUMO

Approximately 20% of Beckwith-Wiedemann syndrome (BWS) cases are caused by mosaic paternal uniparental disomy of chromosome 11 (pUPD11). Although pUPD11 is usually limited to the short arm of chromosome 11, a small minority of BWS cases show genome-wide mosaic pUPD (GWpUPD). These patients show variable clinical features depending on mosaic ratio, imprinting status of other chromosomes, and paternally inherited recessive mutations. To date, there have been no reports of a mosaic GWpUPD patient with an autosomal recessive disease caused by a paternally inherited recessive mutation. Here, we describe a patient concurrently showing the clinical features of BWS and autosomal recessive cystinuria. Genetic analyses revealed that the patient has mosaic GWpUPD and an inherited paternal homozygous mutation in SLC7A9. This is the first report indicating that a paternally inherited recessive mutation can cause an autosomal recessive disease in cases of GWpUPD mosaicism. Investigation into recessive mutations and the dysregulation of imprinting domains is critical in understanding precise clinical conditions of patients with mosaic GWpUPD.


Assuntos
Síndrome de Beckwith-Wiedemann/diagnóstico , Síndrome de Beckwith-Wiedemann/genética , Cistinúria/genética , Genes Recessivos , Dissomia Uniparental , Sistemas de Transporte de Aminoácidos Básicos/genética , Sistemas de Transporte de Aminoácidos Neutros/genética , Feminino , Genótipo , Humanos , Lactente , Rim/patologia , Mutação , Polimorfismo de Nucleotídeo Único , Ultrassonografia
10.
Free Radic Res ; 48(11): 1322-33, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25096805

RESUMO

Previous studies have suggested that carbon monoxide (CO) poisoning stimulates cAMP production via purine P2Y11-like receptors in the rat striatum, activating cAMP signaling pathways, resulting in hydroxyl radical ((•)OH) production. Extracellular ATP was thought likely to trigger the cascade, but the present study has failed to demonstrate a clear increase in the extracellular ATP due to CO poisoning. The CO-induced (•)OH production was attenuated by the P2Y11 receptor antagonist NF157, in parallel with its abilities to suppress the CO-induced cAMP production. The (•)OH production was more strongly suppressed by a non-selective P2 receptor antagonist, PPADS, which had no effect on cAMP production. More selective antagonists toward the respective P2 receptors susceptible to PPADS, including NF279, had little or no effect on the CO-induced (•)OH production. The intrastriatal administration of exogenous ATP dose-dependently stimulated (•)OH production, which was dose-dependently antagonized by PPADS and NF279 but not by NF157. Exogenous GTP and CTP dose-dependently stimulated (•)OH production, though less potently. The GTP-induced (•)OH production was susceptible to both of NF279 and PPADS, but the CTP-induced (•)OH production was resistant to PPADS. The mechanism of (•)OH production may differ between CO poisoning and exogenous ATP, while multiple P2 receptors could participate in (•)OH production. The CO-induced (•)OH production was susceptible to the inhibition of NADPH oxidase, but not xanthine oxidase. Also, the NADPH oxidase inhibition suppressed (•)OH production induced by forskolin, a stimulator of intracellular cAMP formation. It is likely that (•)OH is produced by NADPH oxidase activation via cAMP signaling pathways during CO poisoning.


Assuntos
Trifosfato de Adenosina/farmacologia , Intoxicação por Monóxido de Carbono/fisiopatologia , Corpo Estriado/metabolismo , Radical Hidroxila/metabolismo , Antagonistas Purinérgicos/farmacologia , Suramina/análogos & derivados , Animais , Corpo Estriado/efeitos dos fármacos , Masculino , Microdiálise , Ratos , Ratos Sprague-Dawley , Suramina/farmacologia
11.
Leg Med (Tokyo) ; 16(2): 84-8, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24369859

RESUMO

Anomalous origin of the right coronary artery from the pulmonary artery (ARCAPA) is a rare anomaly. It may contribute to myocardial ischemia or sudden death, although the lesion is usually asymptomatic. We report a sudden death case of a 58-year-old man with ARCAPA coexisting with severe atherosclerotic coronary artery disease. He had been healthy until he complained of chest pain, several days before death, despite the discovery of heart murmur in childhood and suspicion of valvular heart disease. The autopsy revealed not only typical findings of the right coronary anomaly with well-developed collateral circulations but also severe atherosclerotic lesions of the left coronary artery, and ischemic change of the myocardium in the left and right coronary arterial perfusion territory. In addition to the "coronary steal" phenomenon primarily caused by ARCAPA, the reduced flow of both coronary arteries and further increase of "coronary steal" due to atherosclerotic obstructive coronary disease might have contributed to the patient's death.


Assuntos
Doença da Artéria Coronariana/patologia , Anomalias dos Vasos Coronários/patologia , Morte Súbita/etiologia , Artéria Pulmonar/anormalidades , Circulação Colateral , Estenose Coronária/patologia , Fibrose , Ventrículos do Coração/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Artéria Pulmonar/patologia
12.
Med Sci Law ; 54(1): 51-3, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24052003

RESUMO

We report a case in which identification of a deceased individual was established using multiple lot numbers printed on a body implantable device. Autopsy of an unknown woman revealed an intramedullary nail inserted within her right femur. The device manufacturer was identified from the configuration of the intramedullary nail, and the "use history" was traced from lot numbers printed on the device's multiple parts. The deceased individual was thus identified as a woman who had attempted suicide by jumping from a height about a year previously and had been transported to a hospital and undergone surgery that included implantation of the intramedullary nail. The main factor contributing to the rapid identification was the manufacturer's and distributor's record of the use history (traceability) of the product, because of their accountability for purposes of quality control. A second contributing factor was multiple lot numbers, resulting in extremely low probability of the same combination of lot numbers being present in multiple individuals. This case confirmed the utility of multiple lot numbers of body implantable devices in forensic identification.


Assuntos
Pinos Ortopédicos , Rotulagem de Produtos , Adulto , Feminino , Fêmur/lesões , Fêmur/cirurgia , Patologia Legal , Fixação Intramedular de Fraturas/instrumentação , Humanos
13.
Endoscopy ; 45(8): 627-34, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23807806

RESUMO

BACKGROUND AND STUDY AIMS: Only a few large cohort studies have evaluated the efficacy and safety of endoscopic necrosectomy for infected walled-off pancreatic necrosis (WOPN). Therefore, a multicenter, large cohort study was conducted to evaluate the efficacy and safety of endoscopic necrosectomy and to examine the procedural details and follow-up after successful endoscopic necrosectomy. PATIENTS AND METHODS: A retrospective review was conducted in 16 leading Japanese institutions for patients who underwent endoscopic necrosectomy for infected WOPN between August 2005 and July 2011. The follow-up data were also reviewed to determine the long-term outcomes of the procedures. RESULTS: Of 57 patients, 43 (75 %) experienced successful resolution after a median of 5 sessions of endoscopic necrosectomy and 21 days of treatment. Complications occurred in 19 patients (33 %) during the treatment period. Six patients died (11 %): two due to multiple organ failure and one patient each from air embolism, splenic aneurysm, hemorrhage from a Mallory - Weiss tear, and an unknown cause. Of 43 patients with successful endoscopic necrosectomy, recurrent cavity formation was observed in three patients during a median follow-up period of 27 months. CONCLUSIONS: Endoscopic necrosectomy can be an effective technique for infected WOPN and requires a relatively short treatment period. However, serious complications can arise, including death. Therefore, patients should be carefully selected, and knowledgeable, skilled, and experienced operators should perform the procedure. Further research into safer technologies is required in order to reduce the associated morbidity and mortality.


Assuntos
Endoscopia do Sistema Digestório , Pâncreas/patologia , Pâncreas/cirurgia , Pancreatopatias/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Drenagem , Endoscopia do Sistema Digestório/efeitos adversos , Feminino , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Necrose/microbiologia , Necrose/cirurgia , Recidiva , Estudos Retrospectivos , Stents , Irrigação Terapêutica , Adulto Jovem
14.
Endoscopy ; 45(5): 362-9, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23616126

RESUMO

BACKGROUND AND STUDY AIMS: No prospective comparison of endoscopic ultrasonography-guided direct celiac ganglia neurolysis (EUS - CGN) vs. EUS-guided celiac plexus neurolysis (EUS - CPN) has been reported. The aim of the current study was to compare the effectiveness of EUS - CGN and EUS - CPN in providing pain relief from upper abdominal cancer pain in a multicenter randomized controlled trial. PATIENTS AND METHODS: Patients with upper abdominal cancer pain were randomly assigned to treatment using either EUS - CGN or EUS - CPN. Evaluation was performed at Day 7 postoperatively using a pain scale of 0 to 10. Patients for whom pain decreased to ≤ 3 were considered to have a positive response, and those experiencing a decrease in pain to ≤ 1 were considered to be completely responsive. Comparison between the two groups was performed using intention-to-treat analysis. The primary endpoint was the difference in treatment response rates between EUS - CGN and EUS - CPN at postoperative Day 7. Secondary endpoints included differences in complete response rates, pain scores, duration of pain relief, and incidence of adverse effects. RESULTS: A total of 34 patients were assigned to each group. Visualization of ganglia was possible in 30 cases (88 %) in the EUS - CGN group. The positive response rate was significantly higher in the EUS - CGN group (73.5 %) than in the EUS - CPN group (45.5 %; P = 0.026). The complete response rate was also significantly higher in the EUS - CGN group (50.0 %) than in the EUS - CPN group (18.2 %; P = 0.010). There was no difference in adverse events or duration of pain relief between the two groups. CONCLUSIONS: EUS - CGN is significantly superior to conventional EUS - CPN in cancer pain relief. CLINICAL TRIAL REGISTRATION: http://www.umin.ac.jp/ctr/index.htm (ID: UMIN-000002536).


Assuntos
Dor Abdominal/terapia , Bloqueio Nervoso Autônomo/métodos , Plexo Celíaco , Gânglios Simpáticos , Manejo da Dor/métodos , Neoplasias Pancreáticas/complicações , Dor Abdominal/etiologia , Idoso , Idoso de 80 Anos ou mais , Anestésicos Locais , Bupivacaína , Endossonografia , Etanol/uso terapêutico , Feminino , Humanos , Análise de Intenção de Tratamento , Masculino , Pessoa de Meia-Idade , Ultrassonografia de Intervenção
15.
Eur Surg Res ; 47(4): 248-53, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22067527

RESUMO

BACKGROUND: Sodium hyaluronate/carboxymethylcellulose (HA/CMC) is difficult to use in a moist environment because of its susceptibility to moisture. METHODS: We developed the three-layered nDM-14R membrane. The surface layers are composed of 1-lactide, glycolide and e-caprolactone copolymers. HA/CMC and nDM-14R were used in all these studies. (1) The central region of 1 × 10 cm specimens (n = 5) was moistened for 0, 5, 10, 20, 30 or 60 s, after which the tensile strength was determined; (2) one side of specimens of 1 × 10 cm (n = 5) was moistened with agar gel for 5, 10, 15 or 30 s, after which the adhesion strength was determined, and (3) Rat cecum (n = 10) was scratched, 3 × 3 cm specimens were placed on the scratched area, and adhesions were evaluated on postoperative day 14. RESULTS AND CONCLUSION: (1) The tensile strength of nDM-14R after contact for 10-30 s was greater than that of HA/CMC. (2) The adhesive strength of HA/CMC after contact for 5-10 s was greater than that of nDM-14R. (3) Adhesion scores in treatment groups were significantly lower than in the control group. The results suggest that nDM-14R has the same antiadhesive effect and allows easier placement under moist conditions than HA/CMC.


Assuntos
Membranas Artificiais , Complicações Pós-Operatórias/prevenção & controle , Aderências Teciduais/prevenção & controle , Animais , Teste de Materiais , Ratos , Solubilidade , Resistência à Tração
16.
Endoscopy ; 43(12): 1070-5, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21971925

RESUMO

BACKGROUND AND STUDY AIMS: Recent studies have evaluated the efficacy of peroral cholangioscopy (POCS) for diagnosis of biliary diseases. In order to obtain clear images with POCS, saline irrigation, which is performed to replace yellow bile, is carried out for an extended duration. The aim of this study was to evaluate the feasibility of replacing saline irrigation with CO2 insufflation during POCS. PATIENTS AND METHODS: A total of 36 patients who had bile duct lesions and were due to undergo POCS were enrolled in the study. Of these patients, 18 underwent POCS using saline irrigation followed by CO2 insufflation, and 18 patients underwent the reverse approach. The two methods were compared with regard to the time required to obtain a clear endoscopic image and the quality of the images. RESULTS: The median time required to obtain a clear endoscopic image using CO2 insufflation (5.0 min) was significantly shorter than that required for saline irrigation (22.5 min; P < 0.001). The quality of the endoscopic images obtained was similar in 27 cases. However, CO2 insufflation provided better images in four cases that showed an abundance of mucin or biliary sludge, and saline irrigation was superior to CO2 insufflation in five cases that showed severe stricture with bleeding and tall papillary lesions. CONCLUSIONS: CO2 insufflation during POCS can reduce procedure time and simplify cholangioscopy. The overall image quality was similar to that obtained with conventional saline irrigation.


Assuntos
Doenças dos Ductos Biliares/diagnóstico , Ductos Biliares , Dióxido de Carbono/administração & dosagem , Endoscopia do Sistema Digestório , Cloreto de Sódio/administração & dosagem , Gravação em Vídeo , Idoso , Feminino , Humanos , Insuflação , Masculino , Pessoa de Meia-Idade , Irrigação Terapêutica
17.
Science ; 333(6046): 1119-21, 2011 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-21868669

RESUMO

A single grain (~3 micrograms) returned by the Hayabusa spacecraft was analyzed by neutron activation analysis. This grain is mainly composed of olivine with minor amounts of plagioclase, troilite, and metal. Our results establish that the Itokawa sample has similar chemical characteristics (iron/scandium and nickel/cobalt ratios) to chondrites, confirming that this grain is extraterrestrial in origin and has primitive chemical compositions. Estimated iridium/nickel and iridium/cobalt ratios for metal in the Itokawa samples are about five times lower than CI carbonaceous chondrite values. A similar depletion of iridium was observed in chondrule metals of ordinary chondrites. These metals must have condensed from the nebular where refractory siderophile elements already condensed and were segregated.

18.
Science ; 333(6046): 1121-5, 2011 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-21868670

RESUMO

The reflectance spectra of the most abundant meteorites, ordinary chondrites, are different from those of the abundant S-type (mnemonic for siliceous) asteroids. This discrepancy has been thought to be due to space weathering, which is an alteration of the surfaces of airless bodies exposed to the space environment. Here we report evidence of space weathering on particles returned from the S-type asteroid 25143 Itokawa by the Hayabusa spacecraft. Surface modification was found in 5 out of 10 particles, which varies depending on mineral species. Sulfur-bearing Fe-rich nanoparticles exist in a thin (5 to 15 nanometers) surface layer on olivine, low-Ca pyroxene, and plagioclase, which is suggestive of vapor deposition. Sulfur-free Fe-rich nanoparticles exist deeper inside (<60 nanometers) ferromagnesian silicates. Their texture suggests formation by metamictization and in situ reduction of Fe(2+).

19.
Appl Radiat Isot ; 69(12): 1706-9, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21596575

RESUMO

As well known, it is difficult to know the exact treatment effect of boron neutron capture therapy (BNCT). It depends on the irradiation time, which is changed rather flexibly. At present, it is once fixed before BNCT. Then the actual stopping time is adjusted during BNCT by some means like activation foils. The author's group hence started development of a single-photon emission computed tomography (SPECT) system for BNCT to know the effect of BNCT in real time. By adopting a side surface (1×2 mm(2)) of a CdTe detector (1×2×20 mm(3)) as radiation entrance window, acceptable spatial resolution and high detection efficiency were simultaneously achieved. Also in about 30 min acceptable number of counts for 478 keV gamma-rays could be expected. In addition, employing a Schottky type detector the energy resolution could be improved. Discrimination of 478 keV and annihilation gamma-rays would thus be successfully made. In the next phase, it is planned to design and develop an array type detector to be implemented in the BNCT-SPECT system.


Assuntos
Terapia por Captura de Nêutron de Boro/instrumentação , Compostos de Cádmio , Telúrio , Tomografia Computadorizada de Emissão de Fóton Único/instrumentação
20.
Endoscopy ; 43(4): 369-72, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21360425

RESUMO

Severe bleeding following endoscopic biliary sphincterotomy (EBS) can sometimes be difficult to manage, resulting in the need for an invasive intervention. The aim of this study was to retrospectively evaluate the feasibility and efficacy of endoscopic hemostasis using covered self-expandable metallic stents (SEMSs) for severe post- EBS bleeding. Eleven patients with bile duct stones underwent standard EBS using a standard sphincterotome-based technique at 4 endoscopic units of a university-affiliated hospital and a general hospital. Monotherapy or combined therapy were used to achieve hemostasis with either balloon tamponade, hypertonic saline epinephrine injection, or endoclip placement. When active bleeding could not be controlled, covered SEMSs were placed across the major papilla. Emergency endoscopy was performed on the day of admission or the subsequent day (ranging from 6 to 35 h after admission). Bleeding was classified as mild in 6 cases (54.5 %) and moderate in 5 (45.5 %). A covered SEMS 10mm in diameter and 6 cm long was placed across the papilla. After placement, complete hemostasis was achieved. The mean duration of stent placement was 8.2 days (range 5­10 days), and the SEMS was successfully removed in all cases. Although the present study has the limitations of a small sample size and lack of control patients, covered SEMS placement for endoscopic hemostasis may be useful in selected patients with uncontrolled post-EBS bleeding.


Assuntos
Hemorragia/terapia , Hemostase Endoscópica , Esfinterotomia Endoscópica/efeitos adversos , Stents , Idoso , Idoso de 80 Anos ou mais , Materiais Revestidos Biocompatíveis , Emergências , Feminino , Hemorragia/diagnóstico , Hemorragia/etiologia , Humanos , Masculino , Pessoa de Meia-Idade
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