New parameters for in vitro development of cell lines of the species Astyanax bimaculatus (Linnaeus, 1758) and Geophagus proximus (Castelnau, 1855).

Intending to compare in vitro cell growth in different conditions, we established cell cultures using fin biopsies of two freshwater fishes, Astyanax bimaculatus and Geophagus proximus. Three different culture media (Leibovitz-L-15, Dulbecco's Modified Eagle Medium [DMEM], and 199) were employed, with or without the addition of AmnioMax, maintaining a standard temperature of 29°C. Based on the results obtained, we standardized a cell growth protocol in which medium 199 was less efficient for both species.

Comparative cytogenetics of microsatellite distribution in two tetra fishes (Linnaeus, 1758) and (Jenyns, 1842).

Background: The main cytogenetic studies of the Characidae family comprise the genera and involving the use of repetitive DNA probes. However, for the microsatellite classes, studies are still scarce and the function of these sequences in the genome of these individuals is still not understood. Thus, we aimed to analyze and compare the distribution of microsatellite sequences in the species and .

Characterization of a new cytotype and ocurrence of a B microchromosome in two spot astyanax, Astyanax bimaculatus Linnaeus, 1758 (Characiformes: Characidae).

Although Astyanax bimaculatus is the most representative species of the genus in the Amazon region, there are no cytogenetic studies of A. bimaculatus species in Amazon region. Thus, we aimed to analyse the chromosome complements of specimens from this area using classic and molecular cytogenetic approaches.

Evolutionary Dynamics of Two Classes of Repetitive DNA in the Genomes of Two Species of Elopiformes (Teleostei, Elopomorpha).

The order Elopiformes includes fish species of medium to large size with a circumglobal distribution, in both the open sea, coastal, and estuarine waters. The Elopiformes are considered an excellent model for evolutionary studies due to their ample adaptive capacity, which allow them to exploit a range of different ecological niches. In this study, we analyzed the karyotype structure and distribution of two classes of repetitive DNA (microsatellites and transposable elements) in two Elopiformes species ( and ).

Oral HPV among people who use crack-cocaine: prevalence, genotypes, risk factors, and key interventions in a remote Northern Brazilian region.

Objectives: This study estimated the prevalence, genotype distribution, and the factors associated with oral human papillomavirus (HPV) in people who use crack-cocaine (PWUCC) in a remote Brazilian region.

Materials And Methods: This cross-sectional study used community-based snowball sampling methods for participant recruitment. Socio-demographic, economic, drug use, and health-related information was collected from 278 PWUCC in the cities of Bragança and Capanema in northern Brazil.

Treponema pallidum in female sex workers from the Brazilian Marajó Archipelago: prevalence, risk factors, drug-resistant mutations and coinfections.

Background: Female sex workers (FSWs) are an especially vulnerable group for syphilis and other sexually transmitted infection (STIs). This study determined the prevalence of syphilis in FSWs and factors associated with this disease in the Marajó Archipelago (northern Brazil), as well as the frequency of point mutations (A2058G and A2059G) in the 23S rRNA gene of Treponema pallidum and coinfections with hepatitis B virus (HBV), hepatitis C virus (HCV) and hepatitis D virus (HDV).

Methods: FSWs were diagnosed using a rapid qualitative test and the isolates were evaluated for the presence of point mutations by real-time PCR.

Range distribution and contributions to taxonomy of Elops smithi (ELOPIFORMES: ELOPIDAE).

This study presents the first record of Elops smithi for northern Brazil. The evidence suggests this species is being misidentified incorrectly as Elops saurus in estuaries of the Western Atlantic Ocean. Here, morphological, molecular, and cytogenetic evidence identified all ladyfish specimens from one estuary in the region as E.

Prevalence and risk factors for HIV-1 infection in people who use illicit drugs in northern Brazil.

Background: People who use illicit drugs (PWUDs) have a high risk of viral infections. To date, there is a paucity of information on HIV infection among PWUDs in remote Brazilian regions. This study determined the prevalence and factors associated with HIV-1 infection among PWUDs in northern Brazil.

Hepatitis C Virus among Female Sex Workers: A Cross-Sectional Study Conducted along Rivers and Highways in the Amazon Region.

Background: Previous studies found a high prevalence of pathogens among female sex workers (FSWs) in the Amazon region, and established their parenteral and sexual transmission. This study estimated the prevalence of hepatitis C virus (HCV) infection and associated risk factors, and the frequency of HCV genotypes and resistance-associated substitutions (RASs) in this vulnerable group.

Methods: Distinct sampling methods were used to access 412 FSWs in cities and riverside communities in the Amazon region from 2015 to 2018.

Human T-lymphotropic virus 1 and 2 among people who used illicit drugs in the state of Pará, northern Brazil.

People who used illicit drugs (PWUDs) represent an important population group for acquisition and viral dispersion. In Brazil, high rates of the human T lymphotropic virus 1 (HTLV-1) and 2 (HTLV-2) have been reported in epidemiological studies. However, the epidemiological scenario of HTLV-1/2 infections in PWUDs is still poorly understood.

Hepatitis C virus infection status and associated factors among a multi-site sample of people who used illicit drugs in the Amazon region.

Background: Elevated rates of Hepatitis C Virus (HCV) infection have been reported in epidemiological studies with people who used illicit drugs (PWUIDs) in different Brazilian regions. In Brazil's Amazon region, studies have already identified the common use of illicit drugs among adolescents and the high prevalence of HCV infections among PWUIDs. However, all studies done with PWUIDs were conducted with small samples and within limited geographic coverage.

Prevalence and Risk Factors for Human Immunodeficiency Virus Infection Among Female Sex Workers: Distinct Offers of Sexual Services in a Municipality of the Brazilian Amazon.

This study determined the prevalence of human immunodeficiency virus (HIV) infection and its associated factors in female sex workers (FSWs) from the municipality of Bragança in the state of Pará, Brazil. A cross-sectional study using a respondent-driven sampling method was used to investigate 137 FSWs. They were interviewed using a questionnaire for the collection of data on their characteristics and risk behavior.

Genomic Organization of the Repetitive Sequences in (Perciformes, Centropomidae): Implications for Hybridization and Aquaculture Programs.

The family Centropomidae includes a number of fish species of high commercial value. One of these species, , is a target of artisanal, industrial, and sports fisheries and has also considerable potential for captive breeding, which has led to its inclusion in several aquaculture programs. While the biology and ecology of are relatively well documented, few karyological data are available on this species, and they are still scarce for other centropomids.

Syphilis in female sex workers: an epidemiological study of the highway system of the state of Pará, northern Brazil.

Introduction: Female sex workers (FSWs) are considered a bridge for transmission of pathogens from high-risk to general populations. We assessed the epidemiological status of syphilis in FSWs along the Pará highway system.

Methods: Two hundred and twenty-two FSWs were interviewed and samples were analyzed using rapid qualitative tests and real-time polymerase chain reaction.

Prevalence of HCV infection and associated factors among illicit drug users in Breves, State of Pará, northern Brazil.

Introduction: Illicit drug users (DUs) are vulnerable to hepatitis C virus (HCV) infection. The shared use of illicit drugs is the main method of HCV transmission.

Methods: A cross-sectional study was conducted in Breves, in northern Brazil.

The history of the introduction of the giant river prawn, Macrobrachium cf. rosenbergii (Decapoda, Palaemonidae), in Brazil: New insights from molecular data.

The giant river prawn, Macrobrachium cf. rosenbergii, is one of the most cultivated freshwater prawns in the world and has been introduced into more than 40 countries. In some countries, this prawn is considered an invasive species that requires close monitoring.