39 research outputs found
Metastases from renal cell carcinoma presenting as gastrointestinal bleeding: two case reports and a review of the literature
BACKGROUND: Bleeding from small bowel neoplasms account for 1–4% of cases of upper gastrointestinal haemorrhage. Renal cell carcinoma constitutes 3% of all adult malignancies and often presents insidiously. Consequently 25–30% of patients have metastases at the time of diagnosis. Gastrointestinal bleeding from renal cell carcinoma metastases is an uncommon and under-recognised manifestation of this disease. CASE REPORT: In this report we describe two cases of gastrointestinal bleeding from renal cell carcinoma metastases – in one patient bleeding heralded the primary manifestation of disease and in the other signified recurrence of disease following nephrectomy. CONCLUSION: These cases highlight the importance endoscopic vigilance in cases of undiagnosed upper gastrointestinal haemorrhage, especially in patients with a past history of renal cell carcinoma
Impact of global seismicity on sea level change assessment
We analyze the effect of seismic activity on sealevel variations,
by computing the time-dependent vertical crustal movement and geoid change
due to coseismic deformations and postseismic relaxation effects. Seismic activity
can affect both the absolute sealevel, by changing the Earth gravity
field and hence the geoid height, and the relative sealevel, i.e. the radial distance
between seafloor and geoid level. By using comprehensive seismic catalogues
we assess the net effect of seismicity on tidal relative sealevel measurements
as well as on the global oceanic surfaces, and we obtain an estimate
of absolute sealevel variations of seismic origin.
We improved the computational methods adopted in previous analyses considering
the issue of water volume conservation through the application of
the sealevel equation and enabling us to evaluate the effect of an extremely
large number of earthquakes on large grids covering the whole oceanic surfaces.
These new potentialities allow us to perform more detailed investigations
discovering a quantitative explanation for the overall tendency of earthquakes
to produce a positive global relative sealevel variation. Our results
confirm the finding of a previous analysis that, on a global scale, most of the
signal is associated with few giant thrust events, and that RSL estimates obtained
using tide-gauge data can be sensibly affected by the seismic driven
sealevel signal.
The recent measures of sealevel obtained by satellite altimetry show a wide
regional variation of sealevel trends over the oceanic surfaces, with the largest
deviations from the mean trend occurring in tectonically active regions. While our estimates of average absolute sealevel variations turn out to be orders
of magnitude smaller than the satellite measured variations, we can still argue
that mass redistribution associated with aseismic tectonic processes may
contribute to the observed regional variability of sealevel variations. A detailed
study of these tectonic contributions is important to acquire a complete
understanding of the global sealevel variations and will be subject of
future investigations