Yellow fever outbreak affecting Alouatta populations in southern Brazil (Rio Grande do Sul State), 2008-2009

The natural transmission cycle of Yellow Fever (YF) involves tree hole breeding mosquitoes and a wide array of nonhuman primates (NHP), including monkeys and apes. Some Neotropical monkeys (howler monkeys, genus Alouatta) develop fatal YF virus (YFV) infections similar to those reported in humans, even with minimum exposure to the infection. Epizootics in wild primates may be indicating YFV circulation, and the surveillance of such outbreaks in wildlife is an important tool to help prevent human infection. In 2001, surveillance activities successfully identified YF-related death in a black-and-gold howler monkey (Alouatta caraya), Rio Grande do Sul State (RGS) in southern Brazil, and the YFV was isolated from a species of forest-dwelling mosquito (Haemagogus leucocelaenus). These findings led the State Secretariat of Health to initiate a monitoring program for YF and other 18 arboviral infections in Alouatta monkeys. The monitoring program included monkey captures, reporting of monkey casualties by municipalities, and subsequent investigations. If monkey carcasses were found in forests, samples were collected in a standardized manner and this practice resulted in increased reporting of outbreaks. In October 2008, a single howler monkey in a northwestern RGS municipality was confirmed to have died from YF. From October 2008 to June 2009, 2,013 monkey deaths were reported (830 A. caraya and 1,183 A. guariba clamitans). Viruses isolation in blood, viscera, and/or immunohistochemistry led to the detection of YF in 204 of 297 (69%) (154 A. g. clamitans and 50 A. caraya) dead Alouatta monkeys tested. The number of municipalities with confirmed YFV circulation in howlers increased from 2 to 67 and 21 confirmed human cases occurred. This surveillance system was successful in identifying the largest YF outbreak affecting wild NHP ever recorded.     

Changes in mammary uptake and metabolic fate of glucose with once-daily milking and feed restriction in dairy cows

The aim of this review is to better understand the regulation of milk yield in response to once-daily milking and feed restriction. Glucose is the principal precursor for the synthesis of lactose (a major osmotic agent in milk), and participates in determining the milk volume produced. When applying these two breeding factors, reductions in milk yield are associated with a reduction in milk lactose yield and in the arterial flow of glucose, due to a decrease in the mammary blood flow. The ability of the udder to extract glucose is altered with once-daily milking but not necessarily with feed restriction. Lactose synthesis is down-regulated in response to once-daily milking and feed restriction but the percentage of the extracted glucose which is converted into lactose is differently affected in response to treatments. No marked change is observed with once daily milking whereas this would be increased with feed restriction and in contrast, depressed with fasting.     

Design and synthesis of novel N-sulfonyl-2-indole carboxamides as potent PPAR-gamma binding agents with potential application to the treatment of osteoporosis

The synthesis and structure-activity relationships of a novel series of N-sulfonyl-2-indole carboxamides that bind to peroxisome proliferator-activated receptor gamma (PPAR-gamma) are reported. Chemical optimization of the series led to the identification of 4q (IC(50)=50 nM) as a potent binding agent of PPAR-gamma. Also reported is preliminary cell based data suggesting the use of these compounds in the treatment of osteoporosis.     

Structural Basis for Bivalent Smac-Mimetics Recognition in the IAP Protein Family

XIAP is an apoptotic regulator protein that binds to the effector caspases -3 and -7 through its BIR2 domain, and to initiator caspase-9 through its BIR3 domain. Molecular docking studies suggested that Smac-DIABLO may antagonize XIAP by concurrently targeting both BIR2 and BIR3 domains; on this basis bivalent Smac-mimetic compounds have been proposed and characterized. Here, we report the X-ray crystal structure of XIAP-BIR3 domain in complex with a two-headed compound (compound 3) with improved efficacy relative to its monomeric form. A small-angle X-ray scattering study of XIAP-BIR2BIR3, together with fluorescence polarization binding assays and compound 3 cytotoxicity tests on HL60 leukemia cell line are also reported. The crystal structure analysis reveals a network of interactions supporting XIAP-BIR3/compound 3 recognition; moreover, analytical gel-filtration chromatography shows that compound 3 forms a 1:1 stoichiometric complex with a XIAP protein construct containing both BIR2 and BIR3 domains. On the basis of the crystal structure and small-angle X-ray scattering, a model of the same BIR2-BIR3 construct bound to compound 3 is proposed, shedding light on the ability of compound 3 to relieve XIAP inhibitory effects on caspase-9 as well as caspases -3 and -7. A molecular modeling/docking analysis of compound 3 bound to cIAP1-BIR3 domain is presented, considering that Smac-mimetics have been shown to kill tumor cells by inducing cIAP1 and cIAP2 ubiquitination and degradation. Taken together, the results reported here provide a rationale for further development of compound 3 as a lead in the design of dimeric Smac mimetics for cancer treatment.     

Enhancement of <Emphasis Type="Italic">Candida albicans</Emphasis> Virulence After Exposition to Cigarette Mainstream Smoke

The habit of cigarette smoking is associated with higher oral candidal carriage and possible predisposition to oral candidosis. The effects of exposure to smoke on the virulence properties of oral yeasts remain obscure. Hence, we showed in vitro the effect of cigarette smoke condensate (CSC) on ten clinical isolates of Candida albicans obtained from nonsmoking volunteers, as well the type-strain CBS562. CSC was generated by complete burn of five commercial cigarettes in an in-house smoking machine and used to prepare the culture broth in which the strains were grown. In 24-h intervals (T₂₄, T₄₈, and T₇₂), the cells were harvested, washed, subcultured, and the resultant growth were evaluated for possible variations for secreted aspartyl protease, phospholipase, chondroitinase, and hemolysins, adhesion to acrylic and cell surface hydrophobicity (CSH). The results indicated a temporal increase in the secretion rates of enzymes, particularly when yeast cells were exposed to CSC for 48–72 h (P < 0.05). Similarly, adhesion to acrylic and CSH increased with exposure period (P < 0.05). Based on foregoing, we concluded that CSC may promote significant enhance in the secretion of candidal histolytic enzymes and adherence to denture surfaces, thereby promoting oral yeast carriage and possible infection.     

Designing Smac-mimetics as antagonists of XIAP, cIAP1, and cIAP2

Inhibitor of apoptosis proteins (IAPs) such as XIAP, cIAP1, and cIAP2 are upregulated in many cancer cells. Several compounds targeting IAPs and inducing cell death in cancer cells have been developed. Some of these are synthesized mimicking the N-terminal tetrapeptide sequence of Smac/DIABLO, the natural endogenous IAPs inhibitor. Starting from such conceptual design, we generated a library of 4-substituted azabicyclo[5.3.0]alkane Smac-mimetics. Here we report the crystal structure of the BIR3 domain from XIAP in complex with Smac037, a compound designed according to structural principles emerging from our previously analyzed XIAP BIR3/Smac-mimetic complexes. In parallel, we present an in silico docking analysis of three Smac-mimetics to the BIR3 domain of cIAP1, providing general considerations for the development of high affinity lead compounds targeting three members of the IAP family.     

The influence of dietary vitamin C and E supplementation on the physiological response of pirarucu, Arapaima gigas, in net culture

This study evaluated the efficacy of dietary vitamin C (ascorbic acid or AA), vitamin E (alpha-tocopherol or alpha-T), and C+E supplementation on the blood parameters of Arapaima gigas grown in net cages for 45 days. Four treatments were tested: control (commercial feed); C800; E500 and C+E (800+500) with supplementation of 800 mg AA kg(-1), 500 mg alpha-T kg(-1) and 800+500 mg AA+alpha-T kg(-1), respectively. Hematocrit (Ht), red blood cells (RBC), and hemoglobin concentration (Hb) (oxidative status indicators), thrombocytes and leukocytes (immunological indicators), plasma protein and glucose were evaluated. Fish fed vitamin C and C+E supplemented diets showed greater weight gain and survival. Dietary vitamin C and C+E diet supplementation resulted in increased Ht, Hb, RBC, MCHC, total leukocytes, total proteins, thrombocytes and eosinophils compared to the control and alpha-T. The alpha-tocopherol-supplemented diet reduced the number of total thrombocytes, lymphocytes and neutrophils and increased glucose and eosinophils relatively to the control. In general, leukocytes and thrombocytes were good indicators of the efficiency of vitamin on the defense mechanism of the A. gigas reared in cages. Results indicate that high alpha-T diet supplementation provides no benefit for the maintenance of the oxidative or the immunological status of A. gigas. However, it was demonstrated that high dietary AA improves A. gigas immunological status. Red blood cell indices and immune system indicators showed no synergistic effect between the vitamins after supplementing the A. gigas diet with alpha-T+AA.     

Mini-and microsatellite mutations in children from Chernobyl accident cleanup workers

Knowledge about possible genotoxic effects of low-dose radiation on the human germline is limited and relies primarily on extrapolations from high-dose exposures. To test whether ionizing radiation can cause paternal genetic mutations that are transmitted to offspring, we enrolled families of 88 Chernobyl cleanup workers exposed to ionizing radiation. We analyzed DNA isolated from lymphocytes for mutations via DNA blotting with the multi-locus minisatellite probes 33.6 and 33.15 and via PCR in a panel of six tetranucleotide repeats. Children conceived before and children conceived after their father's exposure showed no statistically significant differences in mutation frequencies. We saw an increase in germline microsatellite mutations after radiation exposure that was not statistically significant. We found no dependence of mutation rate on increasing exposure. A novel finding was that the tetranucleotide marker D7S1482 demonstrated germline hypermutability. In conclusion, our results do not support an increased level of germline minisatellite mutations but suggest a modest increase in germline mutations in tetranucleotide repeats. Small sample size, however, limited statistical power.     

Nuclear protein 780BP from cauliflower binds an element in the 780 gene promoter of T-DNA

A 16 bp site of protein binding has been identified in the promoter of the 780 gene of T-DNA. Specific DNA-protein interactions were demonstrated between a double-stranded oligonucleotide containing this element (5-TTGAAAAATCAACGCT-3) and a protein isolated from nuclear extracts of cauliflower inflorescences. Specific bases required for this binding activity (780 binding protein; 780BP) were defined by kinetic competition studies with mutated oligonucleotides, methylation interference assays and DNAse I footprinting. 780BP binding was not competed with up to 1000-fold excess of previously characterized plant regulatory elements such as as-1, the LRE, and the ocs, G-box, and AT-rich elements. In addition, 780BP was shown to bind sequences overlapping a mammalian hormone receptor element with greater affinity than the 780 element.