Annual fluctuations of sunlight and suicides in a region South of the Tropic of Cancer

Studies in temperate countries show a direct correlation between the hours of daily light and the frequency of suicides. This relationship is damped in countries at the equatorial level, and what happens near the tropic lines is unknown. In this paper the suicide rates as well as the monthly average of daily light were analyzed in hours from 1990 to 2016 in Campeche, Mexico, a place with a high rate of suicide deaths and near the latitude of the Tropic of Cancer. The results showed that total suicides and sunshine were positively correlated (r = 0.649; p = 0.022) and the peak of maximum light in June coincides with the maximum suicide peak. There were non-significant peaks of higher suicides in June and December for men and in May for women. However, a clear, significant peak (p = 0.003) showed up in spring. We recommend strengthening the prevention programs during these periods.     

Microglial immune response is impaired against the neurotropic fungus Lomentospora prolificans

Lomentospora (Scedosporium) prolificans is an opportunistic pathogen capable of causing invasive infections in immunocompromised patients. The fungus is able to disseminate via the bloodstream finally arriving at the central nervous system producing neurological symptoms and, in many cases, patient death. In this context, microglial cells, which are the resident immune cells in the central nervous system, may play an important role in these infections. However, this aspect of anti‐L. prolificans immunity has been poorly researched to date. Thus, the interactions and activity of microglial cells against L. prolificans were analysed, and the results show that there was a remarkable impairment in their performance regarding phagocytosis, the development of oxidative burst, and in the production of pro‐inflammatory cytokines, compared with macrophages. Interestingly, L. prolificans displays great growth also when challenged with immune cells, even when inside them. We also proved that microglial phagocytosis of the fungus is highly dependent on mannose receptor and especially on dectin‐1. Taken together, these data provide evidence for an impaired microglial response against L. prolificans and contribute to understanding the pathobiology of its neurotropism.     

Re-expression by Candida albicans germ tubes of antigens lost during subculture of blastospores

The effect of germ tube induction on the antigenic variability in C. albicans was studied in strains from blood cultures (Group I) and superficial candidiasis (Group II). When compared by immunoblotting with a rabbit antiserum, antigenic extracts from Group I strains grown as blastospores showed a higher reactivity than that of Group II strains. Major bands in Group I strains (45–47, 33, 30 kDa) were continuously expressed through the subcultures in vitro but, with the exception of the 45 kDa band, the reactivity of all of them decreased or disappeared after the tenth subculture in Group II strains. The induction of the germ tubes produced the re-expression of the antigens lost during subculture in the yeast form, the effect being very clear in Group II strains. The re-expression by C. albicans germ tubes of antigens lost during subculture of blastospores in vitro and the higher reactivity shown by Group I strains grown in mycelial phase should be taken into consideration when a test to detect anti-C. albicans antibodies is to be developed.Abbreviations GYE glucose-yeast extract agar     

Pectin Lyase Production by a Penicillium italicum Strain

Growth and concomitant production of an extracellular pectin lyase (PL) [poly(methoxylgalactosiduronate) endolyase; EC 4.2.2.10] were investigated in a group of 16 fungi grown in liquid medium containing pectin as a supplementary carbon source. Culture filtrates of both Penicillium italicum (CECT 2294) and P. expansum (CECT 2275) showed the highest PL activity and contained polygalacturonase but not pectinesterase activity. The effect of the inoculum size, the carbon source (sucrose and glucose syrup), and the presence of pectin on the production of PL by P. italicum was studied. The presence of 2.6 mM glycerophosphate in the culture medium enhanced the appearance of PL but was not inhibitory for the in vitro activity. However, glycerol inhibited the enzyme nearly 50% at such a concentration.     

Splanchnic and systemic hemodynamic alterations in chronic, progressive portal hypertensive rats

Systemic and splanchnic hemodynamics were studied by using the radioactive microsphere technique, in rats in which a chronic and progressive portal or intrahepatic hypertension was produced by the placement of a nonconstricting, well fitted ligature around the portal or suprahepatic vein when the rat weighted about 100 g. The hemodynamic measurements were performed 80-90 days after ligature placement. Suprahepatic ligated rats presented portal and intrahepatic hypertension, but nonportal-systemic shunts (PSS). The only hemodynamic disturbance observed was a decrease in renal blood flow. Portal ligated rats showed a wide range of PSS and were divided in two subgroups. The subgroups with high PSS rate (greater than 10%) showed increased cardiac output and plasma renin content, as well as decreased splanchnic blood flow, portal venous inflow, hepatic blood flow and renal blood flow. Low portal-systemic shunts subgroups showed decreased cardiac output while its distribution was similar to the control rats. There was no correlation between portal pressure and shunt rate. Low shunt groups, furthermore, showed increased levels of plasma renin concentration.     

Perturbing pro-survival proteins using quinoxaline derivatives: a structure-activity relationship study

In HeLa cells the combinatorial knockdown of Bcl-xL and Mcl-1 is sufficient to induce spontaneous apoptosis. Quinoxaline derivatives were screened for the induction of Mcl-1 dependent apoptosis using a cell line without functional Bcl-xL. Quinoxaline urea analog 1 h was able to specifically induce apoptosis in an Mcl-1 dependent manner. We demonstrate that even small changes to 1h results in dramatic loss of activity. In addition, 1 h and ABT-737 synergistically inhibit cell growth and induce apoptosis. Our results also suggest that 1h could have therapeutic potential against ABT-737 refractory cancer.