Wild canids,domestic dogs and their pathogens in Southeast Brazil: disease threats for canid conservation

Wild canids are under many pressures, including habitat loss, fragmentation and disease. The current lack of information on the status of wildlife health may hamper conservation efforts in Brazil. In this paper, we examined the prevalence of canine pathogens in 21 free-ranging wild canids, comprising 12 Cerdocyon thous (crab-eating fox), 7 Chrysocyon brachyurus (maned wolf), 2 Lycalopex vetulus (hoary fox), and 70 non-vaccinated domestic dogs from the Serra do Cipó National Park area, Southeast Brazil. For wild canids, seroprevalence of antibodies to canine parvovirus, canine adenovirus, canine coronavirus and Toxoplasma gondii was 100 (21/21), 33 (7/21), 5 (1/19) and 68 (13/19) percent, respectively. Antibodies against canine distemper virus, Neospora caninum or Babesia spp. were not found. We tested domestic dogs for antibodies to canine parvovirus, canine distemper virus and Babesia spp., and seroprevalences were 59 (41/70), 66 (46/70), and 42 (40/70) percent, respectively, with significantly higher prevalence in domestic dogs for CDV (P < 0.001) and Babesia spp. (P = 0.002), and in wild canids for CPV (P < 0.001). We report for the first time evidence of exposure to canine coronavirus in wild hoary foxes, and Platynossomun sp. infection in wild maned wolves. Maned wolves are more exposed to helminths than crab-eating foxes, with a higher prevalence of Trichuridae and Ancylostomidae in the area. The most common ectoparasites were Amblyomma cajennense, A. tigrinum, and Pulex irritans. Such data is useful information on infectious diseases of Brazilian wild canids, revealing pathogens as a threat to wild canids in the area. Control measures are discussed.     

Angiogenic Activity of Breast Cancer Patients’ Monocytes Reverted by Combined Use of Systems Modeling and Experimental Approaches

Angiogenesis plays a key role in tumor growth and cancer progression. TIE-2-expressing monocytes (TEM) have been reported to critically account for tumor vascularization and growth in mouse tumor experimental models, but the molecular basis of their pro-angiogenic activity are largely unknown. Moreover, differences in the pro-angiogenic activity between blood circulating and tumor infiltrated TEM in human patients has not been established to date, hindering the identification of specific targets for therapeutic intervention. In this work, we investigated these differences and the phenotypic reversal of breast tumor pro-angiogenic TEM to a weak pro-angiogenic phenotype by combining Boolean modelling and experimental approaches. Firstly, we show that in breast cancer patients the pro-angiogenic activity of TEM increased drastically from blood to tumor, suggesting that the tumor microenvironment shapes the highly pro-angiogenic phenotype of TEM. Secondly, we predicted in silico all minimal perturbations transitioning the highly pro-angiogenic phenotype of tumor TEM to the weak pro-angiogenic phenotype of blood TEM and vice versa. In silico predicted perturbations were validated experimentally using patient TEM. In addition, gene expression profiling of TEM transitioned to a weak pro-angiogenic phenotype confirmed that TEM are plastic cells and can be reverted to immunological potent monocytes. Finally, the relapse-free survival analysis showed a statistically significant difference between patients with tumors with high and low expression values for genes encoding transitioning proteins detected in silico and validated on patient TEM. In conclusion, the inferred TEM regulatory network accurately captured experimental TEM behavior and highlighted crosstalk between specific angiogenic and inflammatory signaling pathways of outstanding importance to control their pro-angiogenic activity. Results showed the successful in vitro reversion of such an activity by perturbation of in silico predicted target genes in tumor derived TEM, and indicated that targeting tumor TEM plasticity may constitute a novel valid therapeutic strategy in breast cancer.     

Coordination chemistry of iron(III)-porphyrin-antibody complexes.

An artificial peroxidase-like hemoprotein has been obtained by associating a monoclonal antibody, 13G10, and its iron(III)-alpha,alpha,alpha,beta-meso-tetrakis(ortho-carboxyphenyl)porphyrin [Fe(ToCPP)] hapten. In this antibody, about two-thirds of the porphyrin moiety is inserted in the binding site, its ortho-COOH substituents being recognized by amino-acids of the protein, and a carboxylic acid side chain of the protein acts as a general acid base catalyst in the heterolytic cleavage of the O-O bond of H2O2, but no amino-acid residue is acting as an axial ligand of the iron.We here show that the iron of 13G10-Fe(ToCPP) is able to bind, like that of free Fe(ToCPP), two small ligands such as CN-, but only one imidazole ligand, in contrast to to the iron(III) of Fe(ToCPP) that binds two. This phenomenon is general for a series of monosubstituted imidazoles, the 2- and 4-alkyl-substituted imidazoles being the best ligands, in agreement with the hydrophobic character of the antibody binding site. Complexes of antibody 13G10 with less hindered iron(III)-tetraarylporphyrins bearing only one [Fe(MoCPP)] or two meso-[ortho-carboxyphenyl] substituents [Fe(DoCPP)] also bind only one imidazole. Finally, peroxidase activity studies show that imidazole inhibits the peroxidase activity of 13G10-Fe(ToCPP) whereas it increases that of 13G10-Fe(DoCPP). This could be interpreted by the binding of the imidazole ligand on the iron atom which probably occurs in the case of 13G10-Fe(ToCPP) on the less hindered face of the porphyrin, close to the catalytic COOH residue, whereas in the case of 13G10-Fe(DoCPP) it can occur on the other face of the porphyrin. The 13G10-Fe(DoCPP)-imidazole complex thus constitutes a nice artificial peroxidase-like hemoprotein, with the axial imidazole ligand of the iron mimicking the proximal histidine of peroxidases and a COOH side chain of the antibody acting as a general acid-base catalyst like the distal histidine of peroxidases does.     

Demography of a population of Moina micrura kurz (Crustacea: Cladocera) in a temporary pond,peninsula of paraguaná, Venezuela

A population of M. micrura Kurz from a shallow, muddy and temporary pond, located in Peninsula of Paraguaná, western Venezuela, was studied from filling to drying phase. Population density, age structure, fecundity, and length of females, were determined. This population showed a low population density (< 50 ind/1), a low and density-dependent fecundity (mean eggs/adults = 1.3; mean clutch size = 2.1 eggs + embryos), and low juveniles to adults ratio (0.71). No significant correlation was detected between mean clutch size and mean body length of ovigerous females. Our results suggest effects of food limitations, and fish predation on demographic parameters of this population. Still, in unfavourable conditions, some demographics features associated to opportunistic species were evident.     

Effects of peanut rhizobia on the growth and symbiotic performance ofArachis hypogaea under abiotic stress

The effects of saline and osmotic stress on four peanut rhizobia, plant growth and symbiotic N₂-fixation inArachis hypogaea were studied. Abiotic stress was applied by adding either 100 mM NaCl or 20 mM PEG6000. At the rhizobial level,Bradyrhizobium ATCC10317 and TAL1000 showed stronger tolerance to stress than TAL1371 and SEMIA6144. The effect of salinity on the bacterium-plant association was studied by using the variety Blanco Manfredi M68. In the absence of stresses, all the strains induced a significantly higher number of nodules on the roots, although TAL1371 and SEMIA6144 were more effective. Both stresses affected the interaction process, while TALl371 was the best partner.     

Solid-phase synthesis of two glycopeptides containing the amino acid sequence 5 to 9 of somatostatin

2,3,4,6 Tetra-O-acetyl-1-N-[N-(tert-butyloxycarbonyl)-l-aspart-4-oyl]-d-glucopyranosylamine and 2-acetamido-3,4,6-tri-O-acetyl-1-N-[N-(tert-butyloxycarbonyl)-l-aspart-4-oyl]-2-deoxy-d-glucopyranosylamine were introduced, respectively, by the solid-phase procedure in the amino acid sequence 5 to 9 of somatostatin. The two resulting glycopeptides β-d-Glcp-(1→4)- and β-d-GlcpNAc-(1→4)-Asn-Phe-Phe-Trp-Lys-OH were homogeneous on examination by t.l.c. and l.c., and their structures were confirmed by m.s. of the N-acetyl, permethyl derivatives.     

Effect of serum on organogenesis of the rat testis in vitro

Summary It was observed previously that primordia of fetal rat testes when explanted in vitro in a synthetic medium at the outset of sexual differentiation differentiate seminiferous cords during the following days, but that the addition of 15% fetal bovine serum prevents this morphogenesis. In the present study, human, horse, bovine calf, and rat sera were shown to exert the same effect. Very low concentrations of human or fetal bovine serum (0.5 or 1%) were sufficient to produce the serum effect, which was only slightly reduced when the serum was heated. The serum activity was not removed by dialysis (membrane cut-off 15 000), but it disappeared after treatment with trichloroacetic or perchloric acids or after trypsin digestion. Partial purification of the active factor(s) from human serum was achieved by successive gel filtration, affinity chromatography, and ion exchange chromatography. Analysis of the active fractions by electrofocusing and immunoelectrophoresis placed the activity within the α globulin group. Among a series of purified serum proteins tested, α₂-HS-glycoprotein was found to exhibit the serum effect, though this activity was heat labile.     

Maximal aerobic power and leg muscle mass and strength related to age in non-athletic males and females

To investigate the relationships between the age-associated decline in peak oxygen uptake (peak VO2), leg muscle mass (LMM) and leg strength (LS) under the modulating effect of gender and level of physical activity (LPA, as assessed by questionnaire), we evaluated 71 sedentary subjects [males(M):females(F), 34:37], aged 20-80 years. Peak VO2 at maximum cycle ergometry was related to LMM (dual energy X-ray absorptiometry) and LS (isokinetic dynamometry) using both standard (y x x(-1)) and power function ratios (allometry). Absolute values of all variables were higher in males and declined with age (P < 0.01). Differences between the genders disappeared after peak VO2 x LS(-1.46(M)or -1.62(F)) adjustment but remained significant between peak VO2 LMM-(-0.51 (M)or -0.45(F)) and LS LMM- (-091(M) or -1.10(F)) corrected values. Allometric correction of peak VO2 and LS by LMM slowed their age-related declines; the flattening effect however, was more evident in the females. Interestingly, while no age-related decrement in peak VO2 LS(-1) was found, power function ratio values also declined with age, and at a slower rate in females. These findings are consistent with those obtained following a multiple regression analysis using LPA as an independent covariate (P < 0.01). We conclude that using adequate scaling methods and controlling by LPA: (1) no gender differences are observed in peak VO2 adjusted for LS, (2) loss of LS and LMM are important determinants of the age-associated reduction in physical fitness in both genders but (3) age per se has an LS- and LMM-independent influence on the functional decline, although this intrinsic effect of senescence is less pronounced in females.     

Seasonality of some Chihuahuan Desert soil oribatid mites (Acari: Cryptostigmata)

1. Reproductive strategies of four species of oribatid mites were investigated in the Chihuahuan Desert from 1981 to 1984.
2. Breeding activity coincided with the summer rainfall period in three of the four cases: Passalozetes neomexicanus, P. californicus and Jornadia larreae. This pattern was not changed by the application of simulated rainfall at other times of the year. The strict seasonality of reproductive behaviour is interpreted as an outcome of strong selection pressure to recruit only when food quality and quantity and microclimate are most favourable.
3. Joshuella striata showed a more flexible pattern which was essentially bimodal. Periods of egg production occurred in winter and also during the summer rainfall period. This pattern is consistent with the known distribution of this species in winter- and summer-rainfall deserts in south-western USA.