Infra-red laser irradiation enhances interleukin-1 receptor antagonist,increases 3H-thymidine incorporation and the release of [3H]arachidonic acid in human monocytes

The effect of infra-red laser irradiation has been experimented on various biological systems and particularly in human tissues, in vitro as well as in vivo. In order to examine the influence of laser irradiation on cells of the monocytic lineage we have irradiated human peripheral blood mononuclear cells with an infra-red laser at a wavelength of 904 nm, at 2000 Hz frequency and 15 mW for 2 min. Here, we report that laser irradiation for 2 min. at different preincubation times (T = 0 and T = 30 min) enhances LPS (10 g/ml or PHA (10 g/ml, suboptimal concentration) -stimulated monocytes by modifying cell proliferation, as judged by [3H] thymidine incorporation. IL-1 receptor antagonist (IL-1ra) along with an increased release of [3H] Arachidonic acid production, is also influenced by laser irradiated monocytes when treated for 2 min after 1 h incubation. IL-1RA production increased 4-5-fold after laser irradiation, while 3H-arachidonic acid incorporated from PMA-stimulated cellsased and the effect was significant at T = 0 and T = 30 min; while at T = 1 h the effect was negligible. These results may provide new information regarding the effect of laser irradiation on the immune system.     

Frequency of consanguineous marriages among parents and grandparents of Down patients

Summary The existence of a rare autosomal gene which in the homozygous state would cause mitotic nondisjunction in the Down zygote has been hypothesized in the past by Alfi et al. (1980). This hypothesis can be supported or contradicted by the study of the frequency of consanguineous marriages among parents of affected children. Our study on 242 children affected with Down syndrome does not show any increase in the frequency of consanguineous marriages among their parents with respect to the general population, and therefore does not support the hypothesis of an autosomal gene controlling mitotic nondisjunction. Our data do not show any increase in the frequency of consanguineaous marriages even among paternal and maternal grandparents of the affected children, thus not supporting the other possible explanation of an autosomal recessive condition in one of the patient's parents which would cause meiotic nondisjunction.     

Kringle 4 from human plasminogen:1H-nuclear magnetic resonance study of the interactions between ω-amino acid ligands and aromatic residues at the lysine-binding site

The interactions of theω-amino acid ligandsε-aminocaproic acid andp-benzylaminesulphonic acid with the isolated kringle 4 domain from human plasminogen have been investigated by¹H-nuclear magnetic resonance spectroscopy at 300 and 600 MHz. Overall, the data indicate that binding either ligand does not cause the kringle to undergo significant conformational changes. When p-benzylaminesulphonic acid is in excess relative to the kringles, progressive exchange-broadening and high field chemical shifts are observed for the proton resonances of the ligand. The largest effect is seen at the amino end of the molecule, which indicates that the — NH ₃ ⁺ group of the ligand penetrates deeper into the binding site than does the — SO ₃ ^- . Ligand-binding causes signals from the ring-current shifted Leu⁴⁶ CH ₃ ^δ .δ groups and from a number of aromatic side-chains to shift. Depending on the ligand, the latter include Tyr-II (Tyr⁵⁰), Tyr-V (an immobile ring), His-II and His-III imidazole groups and the three Trp indole groups present in kringle 4. In particular,p-benzylaminesulphonic acid-binding induces large high field shifts on the Trp-II H6 triplet and the Trp-III (Trp⁷²) H2 singlet. On the other hand,ε-aminocaproic acid bound to kringle 4 exhibits large chemical shifts of its CH₂ proton resonances, which indicates that the lysine-binding site is rich in aromatic side chains. Overhauser experiments centered on thep-benzylaminesulphonic acid H2,6 and H3,5 aromatic transitions as well as on the shifted Trp-II and Trp-III signals reveal efficient cross-relaxation between these two indole side chains and thep-benzylaminesulphonic acid ring. These experiments also show that the side chains from Phe⁶⁴, Tyr-II (Tyr⁵⁰), Tyr-IV, and His-II (His³¹) interact with the ligand. In combination with reported chemical modification experiments that show requirement of Asp⁵⁷, Arg⁷¹ and Trp⁷² integrity for ligand-binding, our study underscores the relevance of the Cys⁵¹-Cys⁷⁵ loop in defining the kringles’ lysine-binding site. Furthermore, the Cys²²-Cys⁶³ loop is folded so as to place His³¹, His³³, Tyr⁴¹ and Leu⁴⁶ in proximity to the binding site. The involvement of residues within the Cys⁵¹-Cys⁷⁵ loop in ligand-binding suggests that Trp-II and Tyr-IV may correspond to Trp⁶² and Tyr⁷⁴, respectively. As shown by Overhauser experiments, these two residues are in close contact with each other. From these studies and from the shielding and deshielding effects caused byp-benzylaminesulphonic acid, we suggest that the ligand is sandwiched between the indole rings of Trp-II and Trp-III, which form part of the hydrophobic binding site.     

A Comparative Analysis of Genetic Diversity and Structure in Jaguars (Panthera onca), Pumas (Puma concolor), and Ocelots (Leopardus pardalis) in Fragmented Landscapes of a Critical Mesoamerican Linkage Zone

With increasing anthropogenic impact and landscape change, terrestrial carnivore populations are becoming more fragmented. Thus, it is crucial to genetically monitor wild carnivores and quantify changes in genetic diversity and gene flow in response to these threats. This study combined the use of scat detector dogs and molecular scatology to conduct the first genetic study on wild populations of multiple Neotropical felids coexisting across a fragmented landscape in Belize, Central America. We analyzed data from 14 polymorphic microsatellite loci in 1053 scat samples collected from wild jaguars (Panthera onca), pumas (Puma concolor), and ocelots (Leopardus pardalis). We assessed levels of genetic diversity, defined potential genetic clusters, and examined gene flow for the three target species on a countrywide scale using a combination of individual- and population-based analyses. Wild felids in Belize showed moderate levels of genetic variation, with jaguars having the lowest diversity estimates (H_E = 0.57 ± 0.02; A_R = 3.36 ± 0.09), followed by pumas (H_E = 0.57 ± 0.08; A_R = 4.20 ± 0.16), and ocelots (H_E = 0.63 ± 0.03; A_R = 4.16 ± 0.08). We observed low to moderate levels of genetic differentiation for all three target species, with jaguars showing the lowest degree of genetic subdivision across the country, followed by ocelots and pumas. Although levels of genetic diversity and gene flow were still fairly high, we detected evidence of fine-scale genetic subdivision, indicating that levels of genetic connectivity for wild felids in Belize are likely to decrease if habitat loss and fragmentation continue at the current rate. Our study demonstrates the value of understanding fine-scale patterns of gene flow in multiple co-occurring felid species of conservation concern, which is vital for wildlife movement corridor planning and prioritizing future conservation and management efforts within human-impacted landscapes.     

Synthetic Naphthoquinone Derivatives as Anticancer Agents in Ovarian Cancer: Cytotoxicity Assay and Investigation of Possible Biological Mechanisms Action

In this study, eight naphthoquinone derivatives were synthesized in yields ranging from 52 to 96% using easy, fast, and low-cost methodologies. All naphthoquinone derivatives were screened for their in vitro anti-proliferative activities against OVCA A2780 cancer cell lines. Amongst all analysed compounds, derivatives 3 – 5 presented the most prominent cytotoxic potential. Naphthoquinones 3 and 4 , bearing sulfur-containing groups, were identified as having high potential for ROS production, in particular the superoxide anion. Furthermore, 3 and 4 compounds caused a decrease in the cell population in G0/G1 and induced more than 90% of the cell population to apoptosis. Compound 5 did not act in any of these processes. Finally, compounds 3 – 5 were tested for their inhibitory ability against PI3K and MAPK. Compounds 3 and 4 do not inhibit the PI3K enzyme. On the other hand, the naphthoquinone-polyphenol 5 was only able to inhibit the percentage of cells expressing pERK.