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1.
Nature ; 604(7906): 447-450, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35444319

RESUMO

Nova explosions are caused by global thermonuclear runaways triggered in the surface layers of accreting white dwarfs1-3. It has been predicted4-6 that localized thermonuclear bursts on white dwarfs can also take place, similar to type-I X-ray bursts observed in accreting neutron stars. Unexplained rapid bursts from the binary system TV Columbae, in which mass is accreted onto a moderately strong magnetized white dwarf from a low-mass companion, have been observed on several occasions in the past 40 years7-11. During these bursts, the optical/ultraviolet luminosity increases by a factor of more than three in less than an hour and fades in around ten hours. Fast outflows have been observed in ultraviolet spectral lines7, with velocities of more than 3,500 kilometres per second, comparable to the escape velocity from the white dwarf surface. Here we report on optical bursts observed in TV Columbae and in two additional accreting systems, EI Ursae Majoris and ASASSN-19bh. The bursts have a total energy of approximately 10-6  times than those of classical nova explosions (micronovae) and bear a strong resemblance to type-I X-ray bursts12-14. We exclude accretion or stellar magnetic reconnection events as their origin and suggest thermonuclear runaway events in magnetically confined accretion columns as a viable explanation.

2.
Nature ; 603(7899): 52-57, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35236977

RESUMO

All disc-accreting astrophysical objects produce powerful disc winds. In compact binaries containing neutron stars or black holes, accretion often takes place during violent outbursts. The main disc wind signatures during these eruptions are blue-shifted X-ray absorption lines, which are preferentially seen in disc-dominated 'soft states'1,2. By contrast, optical wind-formed lines have recently been detected in 'hard states', when a hot corona dominates the luminosity3. The relationship between these signatures is unknown, and no erupting system has as yet revealed wind-formed lines between the X-ray and optical bands, despite the many strong resonance transitions in this ultraviolet (UV) region4. Here we report that the transient neutron star binary Swift J1858.6-0814 exhibits wind-formed, blue-shifted absorption lines associated with C IV, N V and He II in time-resolved UV spectroscopy during a luminous hard state, which we interpret as a warm, moderately ionized outflow component in this state. Simultaneously observed optical lines also display transient blue-shifted absorption. Decomposing the UV data into constant and variable components, the blue-shifted absorption is associated with the former. This implies that the outflow is not associated with the luminous flares in the data. The joint presence of UV and optical wind features reveals a multi-phase and/or spatially stratified evaporative outflow from the outer disc5. This type of persistent mass loss across all accretion states has been predicted by radiation-hydrodynamic simulations6 and helps to explain the shorter-than-expected duration of outbursts7.

4.
Tech Coloproctol ; 24(5): 421-448, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32172396

RESUMO

The Italian Society of Colorectal Surgery (SICCR) promoted the project reported here, which consists of a position statement of Italian colorectal surgeons to address the surgical aspects of Crohn's disease management. Members of the society were invited to express their opinions on several items proposed by the writing committee, based on evidence available in the literature. The results are presented, focusing on relevant points. The present paper is not an alternative to available guidelines; rather, it offers a snapshot of the attitudes of SICCR surgeons about the surgical treatment of Crohn's disease. The committee was able to identify some points of major disagreement and suggested strategies to improve quality of available data and acceptance of guidelines.


Assuntos
Colite , Cirurgia Colorretal , Doença de Crohn , Doenças Inflamatórias Intestinais , Doença de Crohn/cirurgia , Humanos , Itália
5.
Nature ; 552(7684): 210-213, 2017 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-29239355

RESUMO

White dwarfs are often found in binary systems with orbital periods ranging from tens of minutes to hours in which they can accrete gas from their companion stars. In about 15 per cent of these binaries, the magnetic field of the white dwarf is strong enough (at 106 gauss or more) to channel the accreted matter along field lines onto the magnetic poles. The remaining systems are referred to as 'non-magnetic', because until now there has been no evidence that they have a magnetic field that is strong enough to affect the accretion dynamics. Here we report an analysis of archival optical observations of the 'non-magnetic' accreting white dwarf in the binary system MV Lyrae, whose light curve displays quasi-periodic bursts of about 30 minutes duration roughly every 2 hours. The timescale and amplitude of these bursts indicate the presence of an unstable, magnetically regulated accretion mode, which in turn implies the existence of magnetically gated accretion, in which disk material builds up around the magnetospheric boundary (at the co-rotation radius) and then accretes onto the white dwarf, producing bursts powered by the release of gravitational potential energy. We infer a surface magnetic field strength for the white dwarf in MV Lyrae of between 2 × 104 gauss and 1 × 105 gauss, too low to be detectable by other current methods. Our discovery provides a new way of studying the strength and evolution of magnetic fields in accreting white dwarfs and extends the connections between accretion onto white dwarfs, young stellar objects and neutron stars, for which similar magnetically gated accretion cycles have been identified.

6.
J Chir (Paris) ; 145(1): 67-9, 2008.
Artigo em Francês | MEDLINE | ID: mdl-18438288

RESUMO

The mean age is 50. Symptoms include acute abdominal pain, hypotensive shock, GI bleeding, biliary colic, jaundice, and/or acute anemia. Less often, pancreatico-duodenal aneurysms may be fortuitously diagnosed by abdominal imaging. Rupture of a PDAA is a grave complication with high mortality and demands urgent intervention. Arterial embolization is the treatment of choice; surgical intervention should be reserved for failures of embolization. We report a case of PDAA successfully treated by arterial embolization but which posed problems in both diagnosis and treatment.


Assuntos
Aneurisma/terapia , Duodeno/irrigação sanguínea , Embolização Terapêutica/métodos , Pâncreas/irrigação sanguínea , Idoso , Aneurisma/diagnóstico , Artérias , Artéria Celíaca/patologia , Feminino , Humanos , Resultado do Tratamento
7.
Gastroenterol Clin Biol ; 32(1 Pt. 1): 69-73, 2008 Jan.
Artigo em Francês | MEDLINE | ID: mdl-18405651

RESUMO

Most pseudoaneurysms (PsA) of the peripancreatic arteries cause direct erosion of the arterial wall from pancreatic enzymes that are usually in contact with or in a pseudocyst (PC). Rupturing is a rare and serious complication (90% mortality if untreated). We report the case of a 56-year-old patient with chronic alcoholic pancreatitis who developed a cephaloisthmic PC, complicated with a PsA of the gastroduodenal artery revealed by pain and deglobulization associated with cholestasis. After a diagnostic scan, emergency selective arteriography with coil embolization was performed. Five days later, hemorrhage recurred and a cephalic duodenopancreatectomy was performed. PsA of the gastroduodenal artery occur in the first 10 years of chronic pancreatitis. They are revealed by abdominal pains and/or gastrointestinal hemorrhage or shock from rupture. A scan with arterial reconstruction provides diagnosis. Arteriography is the most sensitive technique to locate the aneurysm and its branches and to perform selective embolization with coils. The failure rate is between 0 and 23%. Surgical treatment (elective ligation of the artery or partial pancreatic excision) should be limited to when embolisation fails and/or recurrent hemorrhage.


Assuntos
Falso Aneurisma/etiologia , Duodeno/irrigação sanguínea , Pseudocisto Pancreático/complicações , Estômago/irrigação sanguínea , Aneurisma Roto/etiologia , Embolização Terapêutica , Hemorragia/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Pâncreas/irrigação sanguínea , Pancreaticoduodenectomia , Pancreatite Alcoólica/complicações , Pancreatite Crônica/complicações , Recidiva , Síndrome
8.
Eur J Surg Oncol ; 34(11): 1246-52, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18222622

RESUMO

INTRODUCTION: The aim of this article was to evaluate the role of hyperthermic intraperitoneal chemotherapy (HIPEC), associated or not to cytoreductive surgery (CS) in the treatment of different stages of advanced gastric cancer (AGC). PATIENTS AND METHODS: Thirty seven patients with AGC who underwent 43 HIPEC from June 1992 to February 2007 were included. HIPEC used Mitomycin-C and Cisplatin for 60-90 min at 41-43 degrees C intra-abdominal temperature. The main endpoints were long-term survivals, morbidity and mortality rates. RESULTS: Eleven patients had no demonstrable sign of PC and constituted the Prophylactic-group, while 26 patients had macroscopic PC (PC-group). Five patients were Gilly 1 or 2 (nodules <0.5 cm) and 21 Gilly 3 or 4 (nodules >or=0.5 cm). In the PC-group a complete curative CS was achieved before HIPEC in 8 (PC-curative subgroup) and a palliative HIPEC in 18 patients (PC-palliative subgroup). The overall 30-days mortality was 5% (2 patients). Two patients in the Prophylactic group died within 6 months after hospital discharge (overall mortality 11%). The estimated risk of death per procedure was 9%. Ten patients (27%) presented one or more complications. The median survival was 23.4 months in the Prophylactic group, and 6.6 months in the PC-group (p<0.05). The median survival in the PC-curative subgroup was 15 vs 3.9 months in the PC-palliative subgroup (p=0.007). The median survival according to Gilly classification was significantly different (Gilly 1&2 vs Gilly 3&4, 15 vs 4 months respectively, p=0.014). The global recurrence rates between the Prophylactic group and the PC-curative subgroup at 2years were 36% vs 50% respectively. The median delay to recurrence was 18.5 vs 9.7 months respectively. CONCLUSION: HIPEC might be useful to improve the survival in selected patients with ACG only when a complete cytoreduction can be achieved. Despite encouraging data, prospective studies, based on larger cohorts of patients are required to assess the role of this procedure as a prophylactic treatment in patients with AGC.


Assuntos
Carcinoma/terapia , Cisplatino/administração & dosagem , Hipertermia Induzida/métodos , Mitomicina/administração & dosagem , Neoplasias Peritoneais/terapia , Neoplasias Gástricas/terapia , Antineoplásicos/administração & dosagem , Carcinoma/mortalidade , Carcinoma/secundário , Quimioterapia Combinada , Feminino , Seguimentos , França/epidemiologia , Humanos , Injeções Intraperitoneais , Masculino , Pessoa de Meia-Idade , Neoplasias Peritoneais/mortalidade , Neoplasias Peritoneais/secundário , Estudos Retrospectivos , Neoplasias Gástricas/mortalidade , Neoplasias Gástricas/patologia , Taxa de Sobrevida/tendências , Fatores de Tempo , Resultado do Tratamento
9.
Eur J Surg Oncol ; 34(2): 154-8, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17640844

RESUMO

AIMS: To review our experience of laparoscopic hyperthermic intraperitoneal chemotherapy (HIPEC) in the treatment of malignant ascites from advanced gastric cancer in order to discuss benefits, problems and possible indications. METHODS: From June 2000 to May 2003 laparoscopic approach was used to perform HIPEC on five patients affected by malignant ascites secondary to unresectable peritoneal carcinomatosis of gastric origin, in order to associate the benefits of a definitive palliation of ascites with a minimal invasiveness. All patients had ascites related symptoms requiring iterative paracenteses. Intraperitoneal perfusion of mitomycin-C and cisplatin was delivered for 60-90min with an inflow temperature of 45 degrees C. RESULTS: Complete clinical regression of ascites and related symptoms was achieved in all the five patients treated. Intraoperative course was uneventful in all cases. Mean operative time was 181min. No postoperative deaths, related to the procedure, occurred. Only a case of delayed gastric empting was recorded as a minor postoperative complication. CONCLUSIONS: Laparoscopic HIPEC appears to be a safe and effective procedure to treat debilitating malignant ascites from unresectable peritoneal carcinomatosis.


Assuntos
Ascite/terapia , Carcinoma/complicações , Quimioterapia do Câncer por Perfusão Regional/métodos , Laparoscopia , Cuidados Paliativos/métodos , Neoplasias Peritoneais/complicações , Adulto , Idoso de 80 Anos ou mais , Ascite/etiologia , Ascite/patologia , Carcinoma/patologia , Carcinoma/terapia , Feminino , Seguimentos , Humanos , Hipertermia Induzida/métodos , Masculino , Pessoa de Meia-Idade , Neoplasias Peritoneais/patologia , Neoplasias Peritoneais/terapia , Estudos Retrospectivos , Medição de Risco , Análise de Sobrevida , Fatores de Tempo , Resultado do Tratamento
11.
J Chir (Paris) ; 144(4): 278-86, 2007.
Artigo em Francês | MEDLINE | ID: mdl-17925730

RESUMO

This Mini-review summarizes the epidemiology, predisposing and pre-cancerous conditions related to carcinoma of the gallbladder. In 75% of cases, gallbladder cancer is a cholangiocarcinoma, usually presenting in a late and advanced stage, and it carries one of the worst prognoses of all GI malignancies. Early stage disease is usually discovered incidentally by the pathologist in a gallbladder specimen removed for calculous cholecystitis. It occurs three times more frequently in women than in men and invasive forms usually occur after the age of 60. Incidence varies with geographic location. Besides genetic and geographic factors, the presence of one or more large gallstones is a major risk factor. Gallbladder polyps larger than 1.5 cm. (especially solitary sessile hypoechogenic polyps) are associated with a 50% risk of malignancy. Choledochal cysts and other variations of the biliopancreatic junction are also associated with high risk; cancer may occur at a much younger age in these patients and in the absence of gallstones. Porcelain gallbladder is a risk factor, particularly when there is calcification of the gallbladder mucosa. Chronic gallbladder infection has been implicated as a risk factor for malignant degeneration. Finally, cancer of both the gallbladder and the bile ducts is more frequent in patients suffering from primary biliary cirrhosis.


Assuntos
Neoplasias da Vesícula Biliar , Lesões Pré-Cancerosas , Adenocarcinoma/epidemiologia , Fatores Etários , Neoplasias dos Ductos Biliares/complicações , Neoplasias dos Ductos Biliares/epidemiologia , Neoplasias dos Ductos Biliares/patologia , Ductos Biliares Intra-Hepáticos , Colangiocarcinoma/complicações , Colangiocarcinoma/epidemiologia , Colangiocarcinoma/patologia , Colangite Esclerosante/complicações , Colecistite/complicações , Feminino , Vesícula Biliar/patologia , Doenças da Vesícula Biliar/complicações , Doenças da Vesícula Biliar/diagnóstico por imagem , Neoplasias da Vesícula Biliar/diagnóstico por imagem , Neoplasias da Vesícula Biliar/epidemiologia , Neoplasias da Vesícula Biliar/patologia , Cálculos Biliares/complicações , Humanos , Incidência , Cirrose Hepática Biliar/complicações , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Pólipos/complicações , Pólipos/diagnóstico por imagem , Lesões Pré-Cancerosas/diagnóstico por imagem , Lesões Pré-Cancerosas/epidemiologia , Lesões Pré-Cancerosas/patologia , Prognóstico , Fatores de Risco , Fatores Sexuais , Tomografia Computadorizada por Raios X , Ultrassonografia
12.
Minerva Chir ; 57(5): 649-55, 2002 Oct.
Artigo em Italiano | MEDLINE | ID: mdl-12370666

RESUMO

BACKGROUND: Helicobacter pylori is an identified carcinogen for gastric cancer, but the underlying mechanisms remain to be defined. The aim of this study is to analyze the incidence of Hp infection in our series of patients with gastric carcinoma. METHODS: Between 1988 and 1998, 60 patients with diagnosis of gastric adenocarcinoma underwent partial or total gastrectomy. Forty-one were males and 19 females with an average age of 62 years (range 36-79). Twenty-seven cancers (45%) were localized in the lower third of the stomach, 17 (28%) in the middle third and eight (13%) in the upper third or cardias. In six patients (10%) the tumor was multicentric, while a recurrence on gastric stump after subtotal gastrectomy was present in two cases (3%). According to Lauren's criteria 39 cancers (65%) were of intestinal type, 16 (27%) of diffuse type and five (8%) of mixed type. The histologic preparations have been re-examined in order to verify the presence or not of Hp on gastric mucosa around neoplasm. RESULTS: Hp was found in 35 (58%) of the analyzed specimens and therefore a significant percentage of patients was Hp-positive at the time of diagnosis and surgery. Between 35 Hp-positive samples, 24 were adenocarcinomas of intestinal type, nine of diffuse type and two of mixed type, with a prevalence of Hp in intestinal type cancer. CONCLUSIONS: This study confirmed the high incidence of Hp infection in patients with gastric carcinoma, particularly in those with intestinal type cancer.


Assuntos
Adenocarcinoma/etiologia , Mucosa Gástrica/microbiologia , Gastrite/complicações , Infecções por Helicobacter/complicações , Helicobacter pylori/isolamento & purificação , Neoplasias Gástricas/etiologia , Adenocarcinoma/microbiologia , Adenocarcinoma/patologia , Adenocarcinoma/cirurgia , Atrofia , Progressão da Doença , Feminino , Gastrectomia , Coto Gástrico , Gastrite/microbiologia , Infecções por Helicobacter/epidemiologia , Infecções por Helicobacter/microbiologia , Helicobacter pylori/patogenicidade , Humanos , Mucosa Intestinal , Itália/epidemiologia , Masculino , Metaplasia , Neoplasias Primárias Múltiplas , Prevalência , Estudos Retrospectivos , Neoplasias Gástricas/microbiologia , Neoplasias Gástricas/cirurgia
13.
J Surg Oncol ; 75(1): 55-8, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11025463

RESUMO

BACKGROUND AND OBJECTIVES: Primary Diffuse Malignant Peritoneal Mesothelioma is a rare disease, with an incidence of 2.2 cases in 1. 000.000 in the USA. It occupies 10% of all mesotheliomas referred in literature. METHODS: We describe a case of diffuse malignant peritoneal mesothelioma arising in a 54-year-old woman who presented a small bowel occlusion. A middle line laparotomy was done; multiple biopsies and an ileostomy were performed. There was not a history of exposure to asbestos. Histologic diagnosis was based on light microscopy, histochemistry, and immunohistochemistry. RESULTS: Patient had no further treatment because of her poor general conditions. She died 4 months later. CONCLUSIONS: Update of treatment is briefly described with particular attention to multimodality approach (surgery, chemotherapy, radiotherapy) and other new therapeutic options (iperthermochemotherapy, immunotherapy, gene therapy), currently in clinical trials.


Assuntos
Mesotelioma , Neoplasias Peritoneais , Feminino , Humanos , Ileostomia , Laparotomia , Mesotelioma/diagnóstico , Mesotelioma/patologia , Mesotelioma/cirurgia , Pessoa de Meia-Idade , Neoplasias Peritoneais/diagnóstico , Neoplasias Peritoneais/patologia , Neoplasias Peritoneais/cirurgia
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