Growth-mediated metabolic activation of promutagens in Aspergillus nidulans

7 procarcinogens belonging to different chemical classes (nitrosamines, hydrazoalkanes, oxazaphosphorines and aromatic amines) were tested in A. nidulans for the induction of point mutations with two genetic systems (8-AG resistance and induction of methionine suppressors).

Dimethylnitrosamine, diethylnitrosamine, nitrosomorpoline, dimethyl-hydrazine, procarbazine and cyclophosphamide gave positive results with a good dose—effect relationship in the growth-mediated assay, whereas they gave negative or borderline positive results in the plate incorporation assay. 2-Aminoanthracene was completely negative with both experimental procedures.

DMN, DEN and NM were also tested for their ability to induce somatic segregation: all were positive when assayed in the growth-mediated assay.     

Amino acids,sugars and sterols of some Mediterranean brown algae

Free amino acids, amino sulfonic acids, sugars and sterols have been examined and quantitatively determined in 10 brown seaweeds. Acidic amino acids and their amides are the main components of the amino acid fraction. Cysteinolic acid, taurine and its N-methyl derivatives have been identified in most of the species examined. In all the algae, mannitol is present, sometimes in very large amounts. The sterol fractions of all the species contain fucosterol, cholesterol and 24-methylenecholesterol; minute amounts of 22-dehydrocholesterol and 24-methylcholesta-5, 22-dien-3β-ol have also been frequently detected.     

The Mutyh Base Excision Repair Gene Influences the Inflammatory Response in a Mouse Model of Ulcerative Colitis

Background

The Mutyh DNA glycosylase is involved in the repair of oxidized DNA bases. Mutations in the human MUTYH gene are responsible for colorectal cancer in familial adenomatous polyposis. Since defective DNA repair genes might contribute to the increased cancer risk associated with inflammatory bowel diseases, we compared the inflammatory response of wild-type and Mutyh^−/− mice to oxidative stress.

Methodology/Principal Findings

The severity of colitis, changes in expression of genes involved in DNA repair and inflammation, DNA 8-oxoguanine levels and microsatellite instability were analysed in colon of mice treated with dextran sulfate sodium (DSS). The Mutyh^−/− phenotpe was associated with a significant accumulation of 8-oxoguanine in colon DNA of treated mice. A single DSS cycle induced severe acute ulcerative colitis in wild-type mice, whereas lesions were modest in Mutyh^−/− mice, and this was associated with moderate variations in the expression of several cytokines. Eight DSS cycles caused chronic colitis in both wild-type and Mutyh^−/− mice. Lymphoid hyperplasia and a significant reduction in Foxp3⁺ regulatory T cells were observed only in Mutyh^−/− mice.

Conclusions

The findings indicate that, in this model of ulcerative colitis, Mutyh plays a major role in maintaining intestinal integrity by affecting the inflammatory response.     

Molecular identification of small cetacean samples from Peruvian fish markets

In the last 60 years, incidental entanglement in fishing gears (so called by-catch) became the main cause of mortality worldwide for small cetaceans and is pushing several populations and species to the verge of extinction. Thus, monitoring and quantifying by-catches is an important step towards proper and sustainable management of cetacean populations. Continuous studies indicated that by-catches and directed takes of small cetaceans in Peru greatly increased since 1985. Legal measures banning cetacean takes, enforced in 1994 and 1996, ironically made monitoring highly problematic as fishers continue catching these animals but utilize or dispose of carcasses clandestinely. Hence, in locations where cetaceans are landed covertly or already butchered, molecular genetic methods can provide the only means of identification of the species, sex, and sometimes the population of each sample. Here, we generate and analyse a fragment of the mitochondrial DNA cytochrome b gene and 5 nuclear microsatellite markers from 182 meat and skin samples of unidentified small cetaceans collected at three Peruvian markets between July 2006 and April 2007. Our results, compared to past surveys, indicate that Lagenorhynchus obscurus, Phocoena spinipinnis, Tursiops truncatus, Delphinus capensis, and D. delphis continue to be caught and marketed, but that the relative incidence of P. spinipinnis is highly reduced, possibly because of population depletion. The small number of possible sampling duplicates demonstrates that a high monitoring frequency is required for a thorough evaluation of incidental catches in the area. A wide public debate on by-catch mitigation measures is greatly warranted in Peru.     

Coordination properties towards palladium(II) of a tridentate dianionic ligand acting as a N- or a N,O-donor

The new palladium(II) complex Pd[C₅H₃N-2,6-(CONPh)₂](η¹-NCMe) (1), prepared from N,N′-diphenyl-2,6-pyridinedicarboxamide and Pd(OAc)₂ in acetonitrile, has been characterized via IR, ¹H NMR and single-crystal X-ray diffraction. In this compound the palladium centre is coordinated to three nitrogen donors of the anionic ligand and to the nitrogen atom of acetonitrile.Moreover, the already known Pd[C₅H₃N-2,6-(CONCH₂CH₂Ph)₂](η¹-NCMe) (2) has been studied by ¹H NMR spectrometry and found to readily convert into the macrocyclic tetranuclear species 3, {Pd[C₅H₃N-2,6-(CONCH₂CH₂Ph)₂]}₄ which has been isolated and characterized by IR, ¹H and ¹³C{¹H} NMR, ¹H-¹³C HETCOR and mass spectrometry, as well as by single-crystal X-ray diffraction. In 3, of S₄ symmetry, each palladium atom is coordinated to the three nitrogen atoms of the anionic ligand, while the fourth coordination position is occupied by the amidato oxygen atom of an adjacent unit. This structure is apparently maintained in CDCl₃ solution. The substitution reactions of acetonitrile in 2 with the ligands EEt₂ (E = S, Se) afford Pd[C₅H₃N-2,6-(CONCH₂CH₂Ph)₂](EEt₂) (4, E = S; 5, E = Se); these products can also be obtained by the addition of EEt₂ to 3, as shown by means of ¹H- and, in the case of E = Se, ⁷⁷Se{¹H} NMR spectroscopy in CDCl₃ solution. These results show that the Pd-O bonds of the tetranuclear species are readily broken by weakly coordinating ligands such as acetonitrile and diethylchalcogenides. Nevertheless, we are dealing with equilibrium reactions and, in some solvents, 3 can be obtained from 2, 4 or 5 being favoured by its low solubility.     

S100A7, Jab1, and p27kip1 expression in psoriasis and S100A7 CRISPR-activated human keratinocyte cell line

Psoriasis, a chronic immune-mediated inflammatory skin disease, is characterized by dysregulated keratinocyte proliferation. The EF-hand calcium binding protein S100A7 has been found to be overexpressed in psoriatic keratinocytes. It is know that S100A7 may interact with Jab1, a cofactor that stabilizes c-Jun. Jab1 is known to downregulate the expression of the cell cycle inhibitor p27^Kip1 in some cancer models. In this study, we aimed to investigate the possible interaction between S100A7 and Jab1 and the downstream effects on p27 ^Kip1 expression in normal human keratinocyte cells transfected with S100A7 CRISPR activation plasmid and in archival psoriatic skin samples. Our results showed that the upregulated S100A7 colocalizes with Jab1 at the nuclear level in transfected cells and psoriatic skin samples. We also showed a differential protein expression of Jab1 between cytoplasmic and nuclear compartments, thus suggesting Jab1 translocation from nucleus to cytoplasm. p27 ^Kip1 protein expression patterns would imply a translocation from nucleus and a subsequent degradation of this protein. The upregulation of S1007 and its interaction with Jab1 would contribute to the p27 ^Kip1-dependent impaired proliferation that characterizes psoriatic skin.     

Spermatocyte chromosome analysis of Helicella virgata (Pulmonata: Helicidae): silver-stained and C-banded chromosomes.

Chromosome numbers of the snail Helicella virgata from the fields of Castellammare del Golfo (Sicily) are n = 26 and 2n = 52. Silver-staining analyses of testicular cells suggest that both mitotic and meiotic chromosomes are involved in nucleolus organization. A within-individual variability in NOR-banding pattern is present in each of the 20 specimens analyzed.     

Levels of spending and resource allocation to HIV programs and services in Latin America and the Caribbean

Background

An estimated 1.86 million people are living with HIV in Latin America and the Caribbean (LAC). The region is comprised of mainly middle-income countries with steady economic growth while simultaneously there are enormous social inequalities and several concentrated AIDS epidemics. This paper describes HIV spending patterns in LAC countries including analysis of the levels and patterns of domestic HIV spending from both public and international sources.

Methods and Findings

We conducted an extensive analysis of the most recently available data from LAC countries using the National AIDS Spending Assessment tool. The LAC countries spent a total of US$ 1.59 billion on HIV programs and services during the latest reported year. Countries providing detailed information on spending showed that high percentages are allocated to treatment and care (75.1%) and prevention (15.0%). Domestic sources accounted for 93.6 percent of overall spending and 79 percent of domestic funds were directed to treatment and care. International funds represented 5.4 percent of total HIV funding in the region, but they supplied the majority of the effort to reach most-at-risk-populations (MARPs). However, prevalence rates among men who have sex with men (MSM) still reached over 25 percent in some countries.

Conclusions

Although countries in the region have increasingly sustained their response from domestic sources, still there are future challenges: 1) The growing number of new HIV infections and more people-living-with-HIV (PLWH) eligible to receive antiretroviral treatment (ART); 2) Increasing ART coverage along with high prices of antiretroviral drugs; and 3) The funding for prevention activities among MARPs rely almost exclusively on external donors. These threats call for strengthened actions by civil society and governments to protect and advance gains against HIV in LAC.     

Survival of the Replication Checkpoint Deficient Cells Requires MUS81-RAD52 Function

In checkpoint-deficient cells, DNA double-strand breaks (DSBs) are produced during replication by the structure-specific endonuclease MUS81. The mechanism underlying MUS81-dependent cleavage, and the effect on chromosome integrity and viability of checkpoint deficient cells is only partly understood, especially in human cells. Here, we show that MUS81-induced DSBs are specifically triggered by CHK1 inhibition in a manner that is unrelated to the loss of RAD51, and does not involve formation of a RAD51 substrate. Indeed, CHK1 deficiency results in the formation of a RAD52-dependent structure that is cleaved by MUS81. Moreover, in CHK1-deficient cells depletion of RAD52, but not of MUS81, rescues chromosome instability observed after replication fork stalling. However, when RAD52 is down-regulated, recovery from replication stress requires MUS81, and loss of both these proteins results in massive cell death that can be suppressed by RAD51 depletion. Our findings reveal a novel RAD52/MUS81-dependent mechanism that promotes cell viability and genome integrity in checkpoint-deficient cells, and disclose the involvement of MUS81 to multiple processes after replication stress.     

Modulation of Chitotriosidase During Macrophage Differentiation

Macrophages as a principal component of immune system play an important role in the initiation, modulation, and final activation of the immune response against pathogens. Upon stimulation with different cytokines, macrophages can undergo classical or alternative activation to become M1 or M2 macrophages, which have different functions during infections. Although chitotriosidase is widely accepted as a marker of activated macrophages and is thought to participate in innate immunity, particularly in defense mechanisms against chitin containing pathogens, little is known about its expression during macrophages full maturation and polarization. In this study we analyzed CHIT-1 modulation during monocyte-to-macrophage maturation and during their polarization. The levels of CHIT-1 expression was investigated in human monocytes obtained from buffy coat of healthy volunteers, polarized to classically activated macrophages (or M1), whose prototypical activating stimuli are interferon-γ and lipopolysaccharide, and alternatively activated macrophages (or M2) obtained by interleukin-4 exposure by real-time PCR and by Western blot analysis. During monocyte–macrophage differentiation both protein synthesis and mRNA analysis showed that CHIT-1 rises significantly and is modulated in M1 and M2 macrophages.Our results demonstrated that variations of CHIT-1 production are strikingly associated with macrophages polarization, indicating a different rule of this enzyme in the specialized macrophages.