RESUMEN
Diblock copolymers confined to a two-dimensional surface may produce uniform features of macromolecular dimensions (approximately 10-100 nm). We present a mathematical model for nanoscale pattern formation in such polymers that captures the dynamic evolution of a solution of poly(styrene)-b-poly(ethylene oxide), PS-b-PEO, in solvent at an air-water interface. The model has no fitting parameters and incorporates the effects of surface tension gradients, entanglement or vitrification, and diffusion. The resultant morphologies are quantitatively compared with experimental data.
RESUMEN
Rapid technologic advances in radiologic imaging and laparoscopic surgery are redefining the indications for endoscopic retrograde cholangiopancreatography (ERCP). The diagnostic role of ERCP continues to diminish in favor of newer imaging modalities such as magnetic resonance cholangiopancreatography (MRCP) and endoscopic ultrasonography. Laparoscopic surgery recaptures some of the indications for therapeutic intervention. The spectrum of diagnostic and therapeutic applications of ERCP, however, continues to expand, enabling a more differentiated diagnosis and treatment of biliopancreatic disease. These applications include ongoing developments of cholangioscopy, pancreatoscopy, and molecular analysis of biliary and pancreatic secretions, photodynamic therapy, and gene therapy.
Asunto(s)
Colangiopancreatografia Retrógrada Endoscópica/tendencias , Bilis/química , Enfermedades de las Vías Biliares/diagnóstico , Enfermedades de las Vías Biliares/terapia , Endosonografía , Predicción , Terapia Genética , Humanos , Laparoscopía , Imagen por Resonancia Magnética , Biología Molecular , Enfermedades Pancreáticas/diagnóstico , Enfermedades Pancreáticas/terapia , Jugo Pancreático/química , Fotoquimioterapia , Tecnología RadiológicaAsunto(s)
Endoscopios Gastrointestinales , Endoscopios , Hemorragia Gastrointestinal/cirugía , Hemostasis Quirúrgica/instrumentación , Endoscopía/métodos , Endoscopía Gastrointestinal/métodos , Seguridad de Equipos , Femenino , Enfermedades Gastrointestinales/diagnóstico , Enfermedades Gastrointestinales/cirugía , Hemorragia Gastrointestinal/diagnóstico , Hemostasis Quirúrgica/métodos , Humanos , Masculino , Sensibilidad y Especificidad , Instrumentos QuirúrgicosRESUMEN
Epstein-Barr (EB) virus infection is common, with up to 90% of individuals demonstrating positive titers by age 20. Although elevated liver function tests commonly occur, severe hepatitis is rare. Only six cases of ascites complicating Epstein-Barr infection are reported, but none clearly demonstrate the absence of other causes of hepatic dysfunction. A 37-yr-old male presented with a 4-wk history of upper respiratory tract symptoms. Over 3 days before admission he developed jaundice and right upper quadrant pain. After hospitalization, the patient developed tense ascites requiring paracentesis. Serum-ascitic albumin gradient was 0.3 g/dL. Liver function tests peaked at the following values: prothrombin time of 24.5 s, total bilirubin of 18.0 mg/dL, and transaminases in excess of 5000 IU/L. EB Virus IgG and IgM titers were 1:640 and >1:40, respectively. Other viral serologies and polymerase chain reactions were negative. The patient experienced a complete clinical and laboratory recovery over the next 6 months. This represents the first documentation of ascites complicating Epstein-Barr infection without other sources of hepatic dysfunction. It demonstrates a narrow serum-ascitic albumin gradient in these patients, and that complete recovery can occur with supportive care.
Asunto(s)
Ascitis/etiología , Infecciones por Virus de Epstein-Barr/complicaciones , Hepatitis Viral Humana/complicaciones , Adulto , Infecciones por Virus de Epstein-Barr/diagnóstico , Hepatitis Viral Humana/diagnóstico , Hepatitis Viral Humana/virología , Humanos , Mononucleosis Infecciosa/complicaciones , MasculinoRESUMEN
I report a case of tick-borne ehrlichiosis in which the primary presentation suggested an infectious diarrhea, with impressive leukopenia and thrombocytopenia. Ehrlichiosis must be included in the differential diagnosis of febrile diarrhea in endemic areas because delay in therapy allows complications and sometimes death. In patients with apparent febrile diarrhea, the presence of leukopenia and thrombocytopenia or elevated aminotransferase values should alert the physician to look for a history of tick bites and consider treatment with doxycycline or tetracycline.
Asunto(s)
Diarrea/etiología , Ehrlichiosis/diagnóstico , Fiebre/complicaciones , Monocitos/microbiología , Adulto , Animales , Mordeduras y Picaduras , Diagnóstico Diferencial , Humanos , Masculino , GarrapatasRESUMEN
Heterotopic gastric mucosa has been identified in all levels of the gastrointestinal tract but is a rare finding in the rectum. We describe a patient with heterotopia found during a routine evaluation of persistent symptoms, possibly due to an irritable bowel syndrome, and provide a complete review of the literature through 1992. Of the 29 reported cases, the most common presentation was painless rectal bleeding, with the heterotopia usually identified on pathologic examination of a rectal polyp. The heterotopic tissue was frequently located in the posterolateral region of the rectum between 5 and 8 cm from the anal verge. The definitive treatment was excision, either by endoscopy or surgery, although H2 may also provide symptom relief. Our patient was treated with H2 with resolution of symptoms.