The dynamics of apparent horizons in Robinson-Trautman spacetimes

We present an alternative scheme of finding apparent horizons based on spectral methods applied to Robinson-Trautman spacetimes. We have considered distinct initial data such as representing the spheroids of matter and the head-on collision of two non-rotating black holes. The evolution of the apparent horizon is presented. We have obtained in some cases a mass gap between the final Bondi and apparent horizon masses, whose implications were briefly commented in the light of the thermodynamics of black holes.Comment: 9 pages, 7 figure

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

Kikuchi's disease associated with Epstein-Barr virus infection

info:eu-repo/semantics/publishedVersio

Riociguat for the treatment of pulmonary arterial hypertension associated with connective tissue disease: results from PATENT-1 and PATENT-2

BACKGROUND: The 12-week, phase III Pulmonary Arterial hyperTENsion sGC-stimulator Trial (PATENT)-1 study investigated riociguat in patients with pulmonary arterial hypertension (PAH). Here, we present a prospectively planned analysis of the safety and efficacy of riociguat in the subgroup of patients with PAH associated with connective tissue disease (PAH-CTD). METHODS: Patients with PAH-CTD were further classified post hoc as having PAH associated with systemic sclerosis or PAH-other defined CTD. In PATENT-1, patients received riociguat (maximum 2.5 or 1.5 mg three times daily) or placebo. Efficacy endpoints included change from baseline in 6-minute walking distance (6MWD; primary endpoint), haemodynamics and WHO functional class (WHO FC). In the long-term extension PATENT-2, patients received riociguat (maximum 2.5 mg three times daily); the primary endpoint was safety and tolerability. RESULTS: In patients with PAH-CTD, riociguat increased mean 6MWD, WHO FC, pulmonary vascular resistance and cardiac index. Improvements in 6MWD and WHO FC persisted at 2 years. Two-year survival of patients with PAH-CTD was the same as for idiopathic PAH (93%). Riociguat had a similar safety profile in patients with PAH-CTD to that of the overall population. CONCLUSIONS: Riociguat was well tolerated and associated with positive trends in 6MWD and other endpoints that were sustained at 2 years in patients with PAH-CTD. TRIAL REGISTRATION NUMBERS: PATENT-1 (NCT00810693), PATENT-2 (NCT00863681)

Aspectos da mortalidade atribuível ao tabaco: revisão sistemática

O artigo teve por objetivo analisar as metodologias publicadas e empregadas no cálculo da mortalidade atribuível ao fumo. Foram pesquisadas as bases de dados eletrônicas MEDLINE, LILACS entre 1990 e 2006. Foram encontrados 186 estudos que apresentaram a mensuração de mortalidade a partir do cálculo da fração atribuível ao fumo. Desses, foram selecionados 41 artigos. Os estudos realizados nos Estados Unidos e Canadá apresentaram metodologia uniformizada e taxas de mortalidade entre 18%-23%; 25%-29% no sexo masculino e 14%-17% no feminino. As variações metodológicas podem justificar as diferenças da mortalidade entre os estudos e nas estimativas para as principais doenças tabaco-relacionadas.The objective of the article was to assess methodologies published and applied in calculating mortality attributable to smoking. A review of the literature was made for the period 1990 to 2006, in the electronic databases MEDLINE and LILACS. A total of 186 studies were found, which measured mortality based on calculating the smoking-attributable risk. Of these, a total of 41 were selected. The studies that were carried out in the United States and Canada presented a more standard methodology and reported smoking attributable mortality to be 18%-23%, with male mortality being 25%-29% and female mortality 14%-17%. The variations can be attributed to methodological differences and to different estimates of the main tobacco-related illnesses

Visceral leishmaniasis and HIV infection in the HAART era

Visceral Leishmaniasis is an endemic infection in Portugal, as well as in other Mediterranean basin countries, where it has become a frequent complication of HIV infection. There are several studies published about Leishmania/HIV co-infection, however some particularities of its epidemiology, pathogenesis and especially of its treatment and prophylaxis remain unclear and undefined. The authors review some aspects of this co-infection, particularly epidemiology, clinical classic manifestations and laboratory features, diagnosis, treatment, prophylaxis and prevention and report the casuistic of the Infectious Diseases Department of the University Hospital of Coimbra during the last ten years (1996-2006) in the HAART (>) era. Visceral Leishmaniasis behaves as an opportunistic infection in HIV-infected patients and should be considered as an AIDS-defining disease. Nowadays and according to World Health Organization, VL is the second most important protozoan disease and one of the most neglected; therefore the establishment of treatment and prophylaxis guidelines is urgent

Microfluidic systems for the analysis of the viscoelastic fluid flow phenomena in porous media

In this study, two microfluidic devices are proposed as simplified 1-D microfluidic analogues of a porous medium. The objectives are twofold: firstly to assess the usefulness of the microchannels to mimic the porous medium in a controlled and simplified manner, and secondly to obtain a better insight about the flow characteristics of viscoelastic fluids flowing through a packed bed. For these purposes, flow visualizations and pressure drop measurements are conducted with Newtonian and viscoelastic fluids. The 1-D microfluidic analogues of porous medium consisted of microchannels with a sequence of contractions/ expansions disposed in symmetric and asymmetric arrangements. The real porous medium is in reality, a complex combination of the two arrangements of particles simulated with the microchannels, which can be considered as limiting ideal configurations. The results show that both configurations are able to mimic well the pressure drop variation with flow rate for Newtonian fluids. However, due to the intrinsic differences in the deformation rate profiles associated with each microgeometry, the symmetric configuration is more suitable for studying the flow of viscoelastic fluids at low De values, while the asymmetric configuration provides better results at high De values. In this way, both microgeometries seem to be complementary and could be interesting tools to obtain a better insight about the flow of viscoelastic fluids through a porous medium. Such model systems could be very interesting to use in polymer-flood processes for enhanced oil recovery, for instance, as a tool for selecting the most suitable viscoelastic fluid to be used in a specific formation. The selection of the fluid properties of a detergent for cleaning oil contaminated soil, sand, and in general, any porous material, is another possible application