Molecular characterization of Brazilian FeLV strains in São Luis, Maranhão Brazil

The feline leukemia virus (FeLV) belongs to the Retroviridae family and Gammaretrovirus genus, and causes a variety of neoplastic and non-neoplastic diseases in domestic cats (Felis catus), such as thymic and multicentric lymphomas, myelodysplastic syndromes, acute myeloid leukemia, aplastic anemia, and immunodeficiency. The aim of the present study was to carry out the molecular characterization of FeLV-positive samples and determine the circulating viral subtype in the city of São Luís, Maranhão, Brazil, as well as identify its phylogenetic relationship and genetic diversity. The FIV Ac/FeLV Ag Test Kit (Alere™) and the commercial immunoenzymatic assay kit (Alere™) were used to detect the positive samples, which were subsequently confirmed by ELISA (ELISA - SNAP® Combo FeLV/FIV). To confirm the presence of proviral DNA, a polymerase chain reaction (PCR) was performed to amplify the target fragments of 450, 235, and 166 bp of the FeLV gag gene. For the detection of FeLV subtypes, nested PCR was performed for FeLV-A, B, and C, with amplification of 2350-, 1072-, 866-, and 1755-bp fragments for the FeLV env gene. The results obtained by nested PCR showed that the four positive samples amplified the A and B subtypes. The C subtype was not amplified. There was an AB combination but no ABC combination. Phylogenetic analysis revealed similarities (78% bootstrap) between the subtype circulating in Brazil and FeLV-AB and with the subtypes of Eastern Asia (Japan) and Southeast Asia (Malaysia), demonstrating that this subtype possesses high genetic variability and a differentiated genotype.

Genetic differentiation in the populations of red piranha, Pygocentrus nattereri Kner (1860) (Characiformes: Serrasalminae), from the river basins of northeastern Brazil

The red piranha, Pygocentrus nattereri, is an important resource for artisanal and commercial fisheries. The present study determines the genetic differentiation among P. nattereri populations from the northeastern Brazilian state of Maranhão. The DNA was isolated using a standard phenol-chloroform protocol and the Control Region was amplified by PCR. The PCR products were sequenced using the didesoxyterminal method. A sequence of 1039 bps was obtained from the Control Region of 60 specimens, which presented 33 polymorphic sites, 41 haplotypes, һ =0.978 and π =0.009. The neutrality tests (D and Fs) were significant (P < 0.05) for most of the populations analyzed. The AMOVA indicated that most of the molecular variation (72%) arises between groups. The fixation index was highly significant (FST = 0.707, P < 0.00001). The phylogenetic analyses indicated that the specimens represented a monophyletic group. Genetic distances between populations varied from 0.8% to 1.9%, and were <0.5% within populations. The degree of genetic differentiation found among the stocks of P. nattereri indicates the need for the development of independent management plans for the different river basins in order to preserve the genetic variability of their populations.

[Pharmaceutical companies as sponsors of clinical trials--advantages and limitations]

The therapeutic progress achieved in the second half of this century was made possible only due to the interest taken by the pharmaceutical industry in the research field. It can be considered as the primum movens of the therapeutic revolution which has strongly benefited the humanity in these last decades. The clinical trials of new drugs constitute an integral part of the pharmaceutical and medical research. However its complexity and the costs involved make its execution impossible without the help or sponsorship of the pharmaceutical firms. Even in the more advanced countries it would be unthinkable that clinical trials could be carried out without the assistance of the pharmaceutical industry. The sponsorship by the pharmaceutical firms turns the relationship doctor-firm into a symbiotic association as both the parties reap benefits thereof: the physician because he is able to satisfy his inquisitiveness and his interest for the clinical research and the pharmaceutical firm because through these trials it will collect the information it requires. Besides having to bear the expenses inherent to the research, the sponsoring firms equally contribute for other pursuits usually of academical character and of interest to the investigator. Therefore it is not rare that these firms assume the costs of presence of these investigators in scientific meetings or to contribute for the arrangements of such meetings or even subsidise the acquisition of the equipment for the hospital services, etc.--measures which in countries with poor investments in research sector, such as Portugal, may constitute the only possibility to be carried out.(ABSTRACT TRUNCATED AT 250 WORDS)