Singular riemannian foliations with sections, transnormal maps and basic forms

A singular riemannian foliation F on a complete riemannian manifold M is said to admit sections if each regular point of M is contained in a complete totally geodesic immersed submanifold (a section) that meets every leaf of F orthogonally and whose dimension is the codimension of the regular leaves of F. We prove that the algebra of basic forms of M relative to F is isomorphic to the algebra of those differential forms on a section that are invariant under the generalized Weyl pseudogroup of this section. This extends a result of Michor for polar actions. It follows from this result that the algebra of basic function is finitely generated if the sections are compact. We also prove that the leaves of F coincide with the level sets of a transnormal map (generalization of isoparametric map) if M is simply connected, the sections are flat and the leaves of F are compact. This result extends previous results due to Carter and West, Terng, and Heintze, Liu and Olmos.Comment: Preprint IME-USP; The final publication is available at springerlink.com http://www.springerlink.com/content/q48682633730t831

FORCED CONVECTION IN DUCTS WITH PERMEABLE WALLS

A mixture theory model is employed in a local description of the energy transfer in a duct with permeable wall which is simulated by considering two distinct flow regions, one consisting of a Newtonian incompressible fluid and the other represented by a binary (solid-fluid) mixture. Compatibility conditions at the interface (pure fluid-mixture) for momentum and energy transfer are considered. The simulations are carried out by using a finite difference approach with an upwind strategy for the convective term discretization

Peritoneal and hepatic hydatid disease causing major bile duct destruction

Echinococcosis is endemic in Mediterranean regions and is found primarily in the liver. Biliary fistula is a common complication, but major biliary duct involvement is very rare, and occurs in 0.47% of patients with hepatic hydatid disease. Cyst rupture causing secondary peritoneal hydatidosis is a rare but serious complication. We report the case of a 27-year-old man with multiple peritoneal and hepatic hydatid cysts. The patient came to our attention with cholestatic jaundice. Imaging exams showed numerous peritoneal cysts and massive hydatid disease of the liver, which involved the hepatic confluence, with destruction of the right hepatic duct and fistula formation to the left hepatic duct. The patient was treated with pre-operative albendazole therapy and radical surgery, which consisted of resection of all peritoneal cysts and extended right hepatectomy with biliary reconstruction. No recurrence was seen on CT investigations on the 12th month following surgery. Radical surgical approach remains the treatment of choice

A Magma Accretion Model for the Formation of Oceanic Lithosphere: Implications for Global Heat Loss

A simple magma accretion model of the oceanic lithosphere is proposed and its implications for understanding the thermal field of oceanic lithosphere examined. The new model (designated VBA) assumes existence of lateral variations in magma accretion rates and temperatures at the boundary zone between the lithosphere and the asthenosphere. Heat flow and bathymetry variations calculated on the basis of the VBA model provide vastly improved fits to respective observational datasets. The improved fits have been achieved for the entire age range and without the need to invoke the ad-hoc hypothesis of large-scale hydrothermal circulation in stable ocean crust. The results suggest that estimates of global heat loss need to be downsized by at least 25%.Comment: 45 pages, 11 figure

Rupture of splenic angiosarcoma: a rare cause of spontaneous haemoperitoneum

Primary splenic angiosarcoma, a very rare mesenchymal tumour of endothelial cell origin, comprises 2.6% of all cases of angiosarcoma and 10% of all primitive splenic tumours. Clinical presentation is usually unspecific, with abdominal pain and anaemia. Rupture is a rare complication and should prompt emergency splenectomy. Prognosis is usually poor because of liver, lung or bone metastases. We describe the case of an 80-year-old woman admitted to the emergency room with syncope, hypotension and vomiting. She stabilised after fluid resuscitation. Investigations showed anaemia, a large, heterogeneous spleen and free fluid in the abdominal cavity. She underwent emergency splenectomy. Pathology revealed primary splenic angiosarcoma. The postoperative period was complicated by respiratory failure but the patient made an otherwise uneventful course and was discharged 2 weeks after surgery. Six months after the operation she remains free of disease with no adjuvant treatment

Locally advanced adenocarcinoma of the rectum presenting with necrotising fasciitis of the perineum: successful management with early aggressive surgery and multimodal therapy

Colorectal cancer is a common malignant neoplasm and its treatment usually involves surgery associated, in some cases, depending on the staging, with chemoradiotherapy. Necrotising fasciitis of the perineum is a highly lethal infection of the perineum, perirectal tissues and genitals, requiring emergency surgical debridement, broad-spectrum antibiotics and control of sepsis. We present the case of a 59-year-old man with necrotising fasciitis of the perineum as the first clinical manifestation of locally advanced adenocarcinoma of the rectum, in which successful management consisted of early and aggressive surgical debridement, followed by multimodal therapy with curative intent. 2 years and 6 months after surgery the patient is well, with no evidence of local or systemic relapse.info:eu-repo/semantics/publishedVersio

Oxaliplatin toxicity presenting as a liver nodule - case report

BACKGROUND: Oxaliplatin based chemotherapy is often used as adjuvant therapy in colon and rectal cancer. A reported side effect is Sinusoidal Obstruction Syndrome which is characterized by a spectrum of pathologic changes, from sinusoidal dilation, peri-sinusoidal haemorrhage, peliosis and nodular regenerative hyperplasia. Very rarely it can cause the development of liver nodules mimicking liver metastases. Herein, we report a case of Sinusoidal Obstruction Syndrome causing a liver nodule suspicious of liver metastasis on imaging. This is the third reported case of this complication of oxaliplatin toxicity, in which resection was performed and pathological diagnosis confirmed. CASE PRESENTATION: We report the case of a 59 year old man with stage III colon cancer who underwent sigmoidectomy followed by adjuvant chemotherapy with oxaliplatin. One year after surgery a liver nodule was detected and the patient underwent right hepatectomy. Pathology showed no liver nodule and diagnosed sinusoidal obstruction syndrome. CONCLUSION: We describe the third reported case of a liver lesion mimicking a liver metastasis after oxaliplatin-based chemotherapy for colon cancer. We suggest that in patients heavily treated with oxaliplatin with de novo liver nodules, this differential diagnosis should be considered. In particular, in this population of patients an intense imagiologic evaluation and even a preoperative biopsy should be pursued to confirm the diagnosis of malignancy and avoid overtreatment.info:eu-repo/semantics/publishedVersio

Colite pseudomembranosa : uma casuística de internamentos

Introduction: pseudomembranous colitis (PMC) is an infectious disease that generally begins after antibiotic treatment. Objectives: Characterize the patients with PMC in two Services of a Central Hospital. Material and Methods: we considered the patients admitted in a Medicine (MS) and in a Gastroenterology (GES) Service with primary or secondary diagnosis of PMC, between January/1995 and July/2003 and registered the age, gender, clinical presentation, antibiotics (AB) and other risk factors, diagnostic procedures, complications and treatment. Results: we considered 80 patients (43 - GES and 37 - MS); Mean age - 68,6 ± 17,7 years; 52,5% were male; Antibiotic treatment in the previous 3 months - 85%; Mean time of antibiotic treatment - 10,5 ± 6,1 days. Most Commonly Involved Antibiotics: cephalosporins, amoxicillin/clavulanic acid and quinolones. Associated risk factors: renal insufficiency (22,5%); cardiac insufficiency (22,5%); previously dependent patient ( 36,3%). Diagnostic procedures: toxin search-58 patients ( in 36 ), colonoscopy - 62 ( in 53); culture - 23 (in 17 ). The mortality rate was 18,8% (n = 15); recurrence rate - 10% (n = 8). Therapeutics: metronidazol - 37 patients (46,3%); vancomycin - 24 (30%); metronidazol + vancomycin – 12 (15%). Differences Between Services: mean age (MS - 72,9 and GES - 64,9); admission criteria (GES - intestinal disorders, MS – respiratory infections); diagnostic procedures (colonoscopy more frequent in GES); therapeutic options (MS - metronidazol; GES - vancomycin and metronidazol + vancomycin). Conclusions: PMC is more common in older patients that were generally submitted to previous antibiotic treatment, especially with ß-lactamics. Considering two distinct Services we observed differences concerning age, co-morbility and risk factors that implied distinct diagnostic and therapeutic approaches