Biomedical subjects
Publications and source records attributed to E Cuevas.
Three cases of lymphomas with splenomegaly onset, without peripheric adenopathies, which required laparotomy to be diagnosed, are discussed. One of the cases was a primary splenic lymphoma and the other two were associated with reactive hemophagocytosis. Other malign lymphoproliferative processes of predominant splenic onset are discussed.
Surface soil samples from various altitudes on Tenerife Island, ranging from sea level up to 3400 m above mean sea level, were analyzed to study the distribution of 26 polycyclic aromatic hydrocarbons (PAHs) in a remote subtropical area. The stable atmospheric conditions in this island define three vertically stratified layers: marine boundary, trade-wind inversion, and free troposphere. Total PAH concentrations, 1.9 to 6000 microg/kg dry wt., were high when compared with those in tropical areas and in a similar range to those in temperate areas. In the marine boundary layer, fluoranthene (Fla), pyrene (Pyr), benz [a]anthracene (BaA), and chrysene (C + T) were largely dominant. The predominance of Fla over Pyr may reflect photo-oxidative processes during atmospheric transport, although coal combustion inputs cannot be excluded. The PAHs found in higher concentration in the soils from the inversion layer were benzo[b + j]fluoranthene (BbjF) + benzo[k]fluoranthene (BkF) > benzo[e]pyrene (BeP) approximately indeno[1,2, 3-cd]pyrene (Ind) > benzo[a]pyrene (BaP) approximately benzo[ghi]perylene (Bghi) > coronene (Cor) approximately dibenz[a,h]anthracene (Dib), reflecting that high temperatures and insolation prevent the accumulation of PAHs more volatile than BbjF in significant amounts. These climatic conditions involve a process of standardization that prevents the identification of specific PAH sources such as traffic, forest fires, or industrial inputs. Only soils with high total organic carbon (TOC) (e.g., 10-30%) preserve the more volatile compounds such as phenanthrene (Phe), methylphenanthrenes (MPhe), dimethylphenanthrenes (DMPhe), and retene (Ret). However, no relation between PAHs and soil TOC and black carbon (BC) was found. The specific PAH distributions of the free tropospheric region suggest a direct input from pyrolytic processes related to the volcanic emission of gases in Teide.
Semen samples of 190 men attending an andrology clinic were evaluated with bacteriological culture and categorized as negative (group I) and positive (group II); the effect of bacteriospemia on semen characteristics was also analyzed. Semen samples from both groups were simultaneously analyzed for routine parameters such as volume, sperm count, motility, viability and morphology. The semen culture was negative in 34% and positive in 66% of the samples. From 123 samples, 157 aerobes and 8 anaerobes were recovered. The most commonly isolated organism was Staphylococchs epidermidis (in 63% of the samples), followed by Streptococchs viridans (28%), Escherichia coli (9%), Staphylococcus aureus (5%), Streptococcus faecalis (5%), beta-hemolytic Streptococcus (4%), and Enterobacter agglomerans (4%). Other microorganisms, including Klebsiella sp, Candida sp., and Proteus mirabilis, were recovered in fewer than 4% of the specimens. The comparison of semen characteristics between infected and noninfected men showed that motile spermatozoa and viability were lower when the microorganisms were present in the semen. It would appear that the bacteria can have a direct effect on semen quality with negative consequences in fertility.
We report here on the anatomy, histology, and development of the three sets of cardiac valves in embryonic and adult elasmobranch fishes. The sinus venosus is the first segment of the heart to receive blood, and a pair of sinoatrial (SA) valves prevent backward flow of blood into the sinus venosus. The SA valves derive from two dorsolateral infoldings of the cardiac wall and consist of a simple endocardium covering transverse sheets rich in collagen. The SA valves are simple flaps of tissue without papillary muscles or chordae tendineae. Blood from the atrium passes the atrioventricular (AV; semilunar) valves, which are attached to papillary muscles in the ventricle by way of the chordae tendineae. A series of rows of conal or pocket valves (CV) in the conus arteriosus, equipped with chordae tendineae but no papillary muscles, prevent blood from reentering the ventricle. Chordae tendineae form in a similar fashion in both chambers. Elevations from the chamber wall emerge as a sheet covered on both surfaces with endocardium and separated by a core of connective tissue. Endocardial cells extend basal projections toward the opposing epithelium through their basal laminae. Basal cell projections make contact to create perforations that enlarge to produce spaces between the nascent chordae. Fibroblasts in the core of the chordae enlarge and strengthen the chordae by producing linear arrays of collagen fibers.