Prospects of polyploidizing cassava, Manihot esculenta Crantz, by unreduced microspores

Eleven interspecific hybrids of cassava with the wild relatives Manihot glaziovii, M. pseudoglaziovii. M. dichotoma and M. anomala were examined to detect unreduced microspores. The frequency of dyads and triads was counted, as well as pollen viability. Of these hybrids, the second generation progeny of cassava×M. glaziovii showed a high frequency of unreduced microspores (3.7%) permitting their selection for further manipulation of this character. An association of vegetatively-reproduced genotypes and the occurrence of unreduced microspores has also been observed.     

Chromosome number in germplasm accessions of Paspalum (Plicatula group) from different regions in Brazil

We determined the chromosome number of 52 accessions of Paspalum from the germplasm collection of the Centro de Pesquisa de Pecuária do Sudeste (CPPSE/EMBRAPA) originating from different regions in Brazil. All accessions belonged to the Plicatula group, 13 of them being P. plicatulum, three P. guenoarum, two P. yaguaronense, two P. compressifolium, one P. atratum, and 31 still unidentified Paspalum sp. Except for a P. yaguaronense accession that presented 2n=60, all the remaining ones presented 2n=40 chromosomes. This is the first report of the chromosome number of P. atratum. Considering that the basic number for most species in the genus Paspalum is ×=10, the accessions analyzed are tetraploids (2n=4×=40) and hexaploids (2n=6×=60). This revised version was published online in July 2006 with corrections to the Cover Date.     

Detection, accumulation, distribution, and depletion of furaltadone and nifursol residues in poultry muscle, liver, and gizzard

Nitrofurans were broadly used as an extremely effective veterinary antibiotic especially in pig and poultry production farms. Because of fears of the carcinogenic effects on humans, the nitrofurans were banned from use in livestock production in many countries, including the European Union. The present study examines the accumulation, distribution, and depletion of furaltadone and nifursol and of their tissue-bound metabolites [3-amino-5-morpholinomethyl-2-oxazolidinone (AMOZ) and 3,5-dinitro-salicylic acid hydrazine (DNSAH), respectively, in poultry edible tissues (muscle, liver, and gizzards) following administration to chickens of therapeutic and subtherapeutic concentrations of both compounds. Nitrofurans determination was performed by high-performance liquid chromatography-diode array detection and liquid chromatography-tandem mass spectrometry, respectively, for feeds and for poultry tissues. Furaltadone and nifursol, in very low concentrations, were found in samples of muscle, liver, and chicken's gizzard collected from slaughtered animals after 5 weeks of treatment and no withdrawal time period. When a withdrawal time period of 3 weeks was respected, no detectable nitrofuran parent compounds was observed in all of the studied matrices. For AMOZ, concentrations of 270 μg/kg in meat, 80 μg/kg in liver, and 331 μg/kg in gizzard were determined after administration of a medicated feed with furaltadone (132 mg/kg), 3 weeks after withdrawal of treatment. For DNSAH, the concentration values obtained are much lower than those observed for AMOZ. For meat, liver, and gizzard, DNSAH concentrations of 2.5, 6.4, and 10.3 μg/kg, respectively, were determined, after administration of a medicated feed with nifursol (98 mg/kg), 3 weeks after withdrawal of treatment. The gizzard could be considered a selected matrix for nitrofuran residues evaluation in poultry, due to its capacity of retaining either nitrofuran parent compounds or metabolites in higher concentrations, regardless of the administered dose or of the respected withdrawal time period.     

Transmission of Leishmania infantum via blood transfusion in dogs: potential for infection and importance of clinical factors

Blood transfusion is an important routine practice in veterinary medicine that generally involves the use of whole blood. Permanent blood donors must be vaccinated against viral infections that affect dogs and submitted periodically to clinical and serological examinations to detect blood-transmitted diseases. There is a very high risk of transmission of infectious agents, particularly protozoans due to their long incubation periods, subclinical persistence in infected animals and likelihood of remaining viable in bloodstocks. The aim of the present study was to identify the potential of asymptomatic and oligosymptomatic dogs for Leishmania infantum transmission as a result of transfusional practice. Nineteen Leishmania-seropositive adult dogs of both sexes and indeterminate breeds were selected as donors. The animals were classified as symptomatic, oligosymptomatic or asymptomatic after clinical examination and evaluated by ELISA, IFAT and bone marrow puncture biopsies. Whole blood and monocyte cells were collected and used for dog's serological evaluation and inoculation in culture medium as well as in hamsters. All but three dogs were positive for IFAT, ELISA and parasite demonstration in bone marrow aspirates, irrespective of their clinical conditions. Parasites were detected in 77% of the whole blood and 90% of the monocyte cultures. Six months after inoculation with whole blood or monocytes, hamsters developed infection and clinical symptoms of visceral leishmaniasis, as well as positive titres measured by ELISA. These results suggest that blood donors should be monitored periodically and rigorously for Leishmania infection, to prevent dissemination of the disease through blood transfusion.     

Production,chemical composition,and economic viability of Minas Frescal cheese from buffaloes supplemented with açai seed

Tropical Animal Health and Production - We aimed to evaluate the chemical composition, production yield, and economic viability of Minas Frescal cheese produced with milk from buffaloes...     

Influence of wine pectic polysaccharides on the interactions between condensed tannins and salivary proteins

Alpha-amylase, a major human salivary protein, and IB8c, a representative of the proline-rich proteins, were obtained by isolation from saliva and by solid-phase synthesis, respectively. The interactions between these proteins and condensed tannins isolated from grape seeds were studied at different protein and tannin concentrations by measuring their aggregation. Pectic polysaccharides were isolated from wine, and their effect on protein tannin aggregation was assessed. The results presented in this study showed that the most acidic fractions of arabinogalactan proteins have the ability to inhibit the formation of aggregates between the grape seed tannins and the two different salivary proteins. Rhamnogalacturonan II has the same ability toward alpha-amylase but not IB8c under the conditions of the present study. Polysaccharides show effects at concentrations at which they are present in wine, which could mean an influence in wine astringency. The interaction between condensed tannins and alpha-amylase is differently affected by ionic strength when compared with IB8c.     

Ultraviolet-C and induced stilbenes control ochratoxigenic Aspergillus in grapes

This study investigated the efficacy of ultraviolet-C (254 nm) and induced stilbenes to inhibit Aspergillus carbonarius and Aspergillus tubingensis and control ochratoxin A production in grapes. In addition, the stilbene synthesis as a response to UV-C treatment and to infection of ochratoxigenic Aspergillus was compared. The initial microbial inactivation by a previously optimized UV-C illumination protocol for increasing trans-resveratrol content in grapes (50 W/m (2), 40 cm, 60 s) was similar on undamaged and damaged grapes, achieving 1.2 and 1.3 log conidia/100 g reductions, respectively. After 5 days of storage at 22 degrees C, UV-C treatment and the stilbenes induced by UV-C inhibited ochratoxigenic Aspergillus growth in undamaged grapes. UV-C elicited the biosynthesis of trans-resveratrol, while microbial infection and tissue damage triggered the biosynthesis of trans-piceid. trans-Resveratrol was not synthesized as a consequence of ochratoxigenic Aspergillus contamination. However, when trans-resveratrol was synthesized by UV-C, it contributed to inhibiting the development of ochratoxin A producing aspergilli. Furthermore, UV-C treatment also contributed to decrease ochratoxin A production by ochratoxigenic aspergilli. Therefore, UV-C is a promising emerging technology either for reducing the potential ochratoxigenic risk in grapes, which is of particular interest to the wine industry, and also for increasing trans-resveratrol content of grapes, which would provide an added value to the wine.