Assuntos

Assuntos

Assuntos

RESUMO

The use of bi-allelic markers such as retrotransposable element insertion polymorphisms or Innuls (for insertion/null) can overcome some limitations of short tandem repeat (STR) loci in typing forensic biological evidence. This study investigated the efficiency of the InnoTyper® 21 Innul markers in an urban admixed population sample in Rio de Janeiro (n = 40) and one highly compromised sample collected as evidence by the Rio de Janeiro police. No significant departures from Hardy-Weinberg equilibrium were detected after the Bonferroni correction (α' ≈ 0.05/20, p < 0.0025), and no significant linkage disequilibrium was observed between markers. Assuming loci independence, the cumulative random match probability (RMP) was 2.3 × 10-8. A lower mean Fis value was obtained for this sample population compared with those of three North American populations (African-American, Southwest Hispanic, US Caucasian). Principal component analysis with the three North American populations and one from 21 East Asian population showed that African Americans segregated as an independent group while US Caucasian, Southwest Hispanic, East Asian, and Rio de Janeiro populations are in a single large heterogeneous group. Also, a full Innuls profile was produced from an evidence sample, despite the DNA being highly degraded. In conclusion, this system is a useful complement to standard STR kits.

Assuntos

RESUMO

Cannabis sativa, known by the common name marijuana, is the psychoactive drug most widely distributed in the world. Identification of Cannabis cultivars may be useful for association to illegal crops, which may reveal trafficking routes and related criminal groups. This study provides evidence for the performance of a segment of the rbcL gene, through genetic signature, as a tool for identification for C. sativa samples apprehended by the Rio de Janeiro Police, Brazil. The PCR amplified and further sequenced the fragment of approximately 561 bp of 24 samples of C. sativa rbcL gene and showed the same nucleotide sequences, suggesting a possible genetic similarity or identical varieties. Comparing with other Cannabaceae family sequences, we have found 99% of similarity between the Rio de Janeiro sequence and three other C. sativa rbcL genes. These findings suggest that the fragment utilized at this study is efficient in identifying C. sativa samples, therefore, useful in genetic discrimination of samples seized in forensic cases.

Assuntos

RESUMO

AIM: To assess the discolouration of teeth with closed and open apices after placement of triple antibiotic paste (TAP, ciprofloxacin, metronidazole and minocycline) in the pulp chamber and whether discolouration could be reversed by internal bleaching procedures. METHODOLOGY: Twenty extracted human mandibular premolars were divided into 2 groups (n = 10): teeth with closed apices (CA) and teeth with open apices (OA). After conventional access, the TAP was sealed in the pulp chamber for 3 weeks. The paste was removed by a rinse with sodium hypochlorite (NaOCl) and a mixture of sodium perborate and distilled water was sealed in the pulp chamber for 1, 2 and 3 weeks. The shade was measured by a spectrophotometer at six time periods: baseline (T0), after 3 weeks of placement of TAP (T1), after removal of TAP with a NaOCl rinse (T2) and after 1 (T3), 2 (T4) and 3 (T5) weeks of internal bleaching with sodium perborate paste. Data were collected based on the CIELAB-CIE1976 (L*a*b*) system and analysed using t-tests and anova. RESULTS: A significant decrease in the mean values of L* (lightness) was observed after treatment with TAP (T1, P < 0.05). Considerable increases in these values after bleaching with sodium perborate (T3 < T4 < T5) were found in both groups. The only significant difference in the intergroup analysis was between T1 and T2, in which ΔE values in the OA group were higher (P = 0.04). CONCLUSIONS: TAP discoloured the tooth structure, but discolouration could be reversed with sodium perborate paste. In general, teeth with closed and open apices had the same rates of discolouration and bleaching.

Assuntos

RESUMO

The majority of STR loci are not ideal for the analysis of forensic samples with degraded and/or low template DNA. One alternative to overcome these limitations is the use of bi-allelic markers, which have low mutation rates and shorter amplicons. Human identification (HID) InDel marker panels have been described in several countries, including Brazil. The commercial kit available is, however, mostly suitable for Europeans, with lower discrimination power for other population groups. Recently, a combination of 49 InDel markers used in four different ethnic groups in the USA has been shown to be more informative than another panel from Portugal, already tested in a Rio de Janeiro sample. However, these 49 InDels have yet to be applied to other admixed or isolated populations. We assessed the efficiency of this panel in two urban admixed populations (Rio de Janeiro, Brazil; Tripoli, Libya) and one isolated Native Brazilian community. All markers are in Hardy-Weinberg equilibrium (HWE) after the Bonferroni correction, and no Linkage disequilibrium was detected. Assuming loci independence and no substructure effect, cumulative RMP was 2.7×10(-18), 1.5×10(-20), and 4.5×10(-20) for Native Brazilian, Rio de Janeiro, and Tripoli populations, respectively. The overall Fst value was 0.05512. Rio de Janeiro and Tripoli showed similar admixture levels, however for Native Brazilians one parental cluster represented over 60 % of the total parental population. We conclude that this panel is suitable for HID on these urban populations, but is less efficient for the isolated group.

Assuntos

Assuntos

RESUMO

In vitro tests were performed to evaluate the ability of 6 isolates of the nematophagous fungus Pochonia chlamydosporia to infect immature and mature Toxocara canis eggs on cellulose dialysis membrane. There was a direct relationship between the number of eggs colonized and the increase in the days of interaction, as well as between the number of eggs colonized and the increase in the concentration of chlamydospores (P<0.05). Immature eggs were more susceptible to infection than mature eggs. The isolate Pc-04 was the most efficient egg parasite until the 7th day, and showed no difference in capacity to infect mature and immature eggs in comparison to Pc-07 at 14 and 21 days of interaction, respectively. Isolate Pc-04 was the most infective on the two evolutionary phases of the eggs at most concentrations, but its ability to infect immature eggs did not differ from that presented by the isolates Pc-07 and Pc-10 at the inoculum level of 5000 chlamydospores. Colonization of infective larvae inside or outside the egg was observed in treatments with the isolates Pc-03, Pc-04, Pc-07 and Pc-10. The isolate Pc-04 of P. chlamydosporia has great biological capacity to destroy immature and mature T. canis eggs in laboratory conditions.

Assuntos

RESUMO

Hepatitis C virus (HCV) infection frequently persists despite substantial virus-specific immune responses and the combination of pegylated interferon (INF)-α and ribavirin therapy. Major histocompatibility complex class I restricted CD8(+) T cells are responsible for the control of viraemia in HCV infection, and several studies suggest protection against viral infection associated with specific HLAs. The reason for low rates of sustained viral response (SVR) in HCV patients remains unknown. Escape mutations in response to cytotoxic T lymphocyte are widely described; however, its influence in the treatment outcome is ill understood. Here, we investigate the differences in CD8 epitopes frequencies from the Los Alamos database between groups of patients that showed distinct response to pegylated α-INF with ribavirin therapy and test evidence of natural selection on the virus in those who failed treatment, using five maximum likelihood evolutionary models from PAML package. The group of sustained virological responders showed three epitopes with frequencies higher than Non-responders group, all had statistical support, and we observed evidence of selection pressure in the last group. No escape mutation was observed. Interestingly, the epitope VLSDFKTWL was 100% conserved in SVR group. These results suggest that the response to treatment can be explained by the increase in immune pressure, induced by interferon therapy, and the presence of those epitopes may represent an important factor in determining the outcome of therapy.

Assuntos

RESUMO

OBJECTIVES: To determine the prevalence of clue cells suggestive for Gardnerella vaginalis in population-based cervical screening in the public (SUS) versus private (RP) health care utilization in Maringá, Paraná, Brazil. METHODS: A retrospective study on the results of 133,966 cytology examinations of patients from the Brazilian Public Health System-SUS (better socio-economic status-SES) and from the Private Network-RP (low SES) done by the Souza Anatomy Laboratory in Maringá, Brazil, from 2004 to 2007. RESULTS: In patients using the SUS, the prevalence of clue cells was 6.75% (n = 3,573), higher (p < 0.05) than for RP users (3.53%, n = 2,813). The clue cells predominated in age range of the 20-49 years from the SUS and RP (p > 0.05). In both the populations, the prevalence and age range did not vary among the 4 years (p > 0.05) and the prevalence declines in age above 45 years (p < 0.05). CONCLUSIONS: The prevalence of clue cells was low and stable in both populations in the 4 years, indicating equilibrium in terms of numbers of bacterial vaginosis (BV) in this localization. The results indicate that SES may influence the epidemiology of BV and that the prevalence declines expressively in older women.

Assuntos

RESUMO

Hepatitis C virus (HCV) infection frequently persists despite substantial virus-specific immune responsesand the combination of pegylated interferon (INF)-a and ribavirin therapy. Major histocompatibility complex class Irestricted CD8+ T cells are responsible for the control of viraemia in HCV infection, and several studies suggestprotection against viral infection associated with specific HLAs. The reason for low rates of sustained viral response (SVR) in HCV patients remains unknown. Escape mutations in response to cytotoxic T lymphocyte are widely described; however, its influence in the treatment outcome is ill understood. Here, we investigate the differences in CD8 epitopes frequencies from the Los Alamos database between groups of patients that showed distinct response to pegylated a-INF with ribavirin therapy and test evidence of natural.

Assuntos

RESUMO

The genotypes of hepatitis B (HBV) and delta (HDV) viruses circulating among fulminant hepatitis cases from the western Amazon Basin of Brazil were characterized in this study. HBV and HDV isolates were obtained from liver samples from 14 patients who developed fulminant hepatitis and died during 1978-1989. HBV DNA and HDV RNA were detected in all samples. Phylogenetic analyses of HDV sequences showed that they all clustered with previously characterized sequences of HDV genotype 3 (HDV-3). HBV genotypes F, A and D were found in 50.0, 28.6 and 21.4 % of cases, respectively. These results confirm the predominance of HDV-3 in South America and its association with the severe form of hepatitis, and the finding of the co-infection of HDV-3 with different genotypes of HBV suggests that the association between HDV-3 and HBV-F is not necessarily causally related to a more severe clinical course of infection.

Assuntos

RESUMO

As a consequence of selective pressure exerted by the immune response during hepatitis C virus (HCV) infection, a high rate of nucleotide mutations in the viral genome is observed which leads to the emergence of viral escape mutants. The aim of this study was to evaluate the evolution of the amino acid (aa) sequence of the HCV nonstructural protein 3 (NS3) in viral isolates after liver transplantation. Six patients with HCV-induced liver disease undergoing liver transplantation (LT) were followed up for sequence analysis. Hepatitis C recurrence was observed in all patients after LT. The rate of synonymous (dS) nucleotide substitutions was much higher than that of nonsynonymous (dN) ones in the NS3 encoding region. The high values of the dS/dN ratios suggest no sustained adaptive evolution selection pressure and, therefore, absence of specific NS3 viral populations. Clinical genotype assignments were supported by phylogenetic analysis. Serial samples from each patient showed lower mean nucleotide genetic distance when compared with samples of the same HCV genotype and subtype. The NS3 samples studied had an N-terminal aa sequence with several differences as compared with reference ones, mainly in genotype 1b-infected patients. After LT, as compared with the sequences before, a few reverted aa substitutions and several established aa substitutions were observed at the N-terminal of NS3. Sites described to be involved in important functions of NS3, notably those of the catalytic triad and zinc binding, remained unaltered in terms of aa sequence. Rare or frequent aa substitutions occurred indiscriminately in different positions. Several cytotoxic T lymphocyte epitopes described for HCV were present in our 1b samples. Nevertheless, the deduced secondary structure of the NS3 protease showed a few alterations in samples from genotype 3a patients, but none were seen in 1b cases. Our data, obtained from patients under important selective pressure during LT, show that the NS3 protease remains well conserved, mainly in HCV 3a patients. It reinforces its potential use as an antigenic candidate for further studies aiming at the development of a protective immune response.

Assuntos

RESUMO

OBJECTIVES: To determine the association of public versus private health care utilization and prevalence of Trichomonas vaginalis in Maringá, Paraná, Brazil. METHODS: A retrospective study on the results of 133,966 cytology examinations of patients from the Brazilian Public Health System (better socio-economic status, SES) and from the Private Network (low SES) done by the Souza Anatomy Laboratory in Maringá, Brazil, from 2004 to 2007. RESULTS: In patients using the SUS, the prevalence of trichomoniasis was 1.44% (n = 782), higher (P < 0.0001) than for RP users (0.18%, n = 147). The infection predominated in age ranges of the 30-39 years and 40-49 years old from the SUS (P < 0.0001) and in ages ranges from 40 to 49 years old from the RP (P < 0.0001). The infection prevalence and age range did not vary among the 4 years (P > 0.05). CONCLUSIONS: The prevalence of Trichomonas spp. was low and stable in both populations in the 4 years, indicating an equilibrium in terms of numbers of this agent in Maringá, Paraná, Brazil. The results corroborate the hypothesis that SES may influence the epidemiology of trichomoniasis. The prevalence of the infection increases with age, a phenomenon not observed with other sexually transmitted infections, such as gonorrhoea or Chlamydia trachomatis.

Assuntos

RESUMO

OBJECTIVES: To determine the prevalence of Candida sp. by cervical-vaginal cytology in patients from the Brazilian Public Health System (SUS) and from the Private Network (RP). METHODS: A retrospective study on the results of cytology exams from the Souza Anatomy Laboratory of Maringá, Paraná state, Brazil, from 2004 to 2006. RESULTS: A total of 94,203 reports of cytology were evaluated, with a prevalence of Candida sp. of 4.94% (n = 4,655), with no significant variation in the two populations or among the 3 years studied (P > 0.05). Candida sp. predominated in both populations, aged between 20 and 39 years (P < 0.0001). The bacterial flora linked to Candida sp. was of lactobacilli (P < 0.05). CONCLUSIONS: With the results obtained, it was noticed that the socio-economical level does not seem to influence the epidemiology of the Candida sp. and pointed to a balance in terms of numbers of this agent in Maringá, Paraná, Brazil.

Assuntos

RESUMO

Occult hepatitis B virus (HBV) infection has been reported among patients with hepatitis C virus (HCV) infection and hepatocellular carcinoma (HCC). Our aim was to evaluate the presence of occult HBV infection in patients with HCV-related liver cirrhosis (LC) with or without HCC in São Paulo, Brazil. Serum and liver tissue samples from 50 hepatitis B surface antigen-negative patients with HCV-related LC who underwent liver transplantation at the University of São Paulo School of Medicine Hospital from 1993 to 2004 were divided into groups with LC only (N = 33) and with LC plus HCC (N = 17). HBV DNA was assayed for serum and paraffin-embedded liver tissue (tumoral and non-tumoral) using real time PCR and only 1 case with HCC had HBV DNA-positive serum. All liver samples were negative. HCV genotype 3 was detected in 17/39 (43.7 percent) cases. In conclusion, using a sensitive real time PCR directed to detect HBV variants circulating in Brazil, occult hepatitis B infection was not found among HCV-positive cirrhotic patients and was rarely found among HCV-positive HCC patients. These results are probably related to the low prevalence of HBV infection in our population. Furthermore, we have also shown that HCV genotype 3 is frequently found in Brazilian cirrhotic patients, particularly when they also have HCC. More studies involving a large number of cases should be carried out to confirm these data and to further characterize Brazilian HCV genotype isolates to elucidate genetic features that might be related to its carcinogenic potential.

Assuntos

RESUMO

Occult hepatitis B virus (HBV) infection has been reported among patients with hepatitis C virus (HCV) infection and hepatocellular carcinoma (HCC). Our aim was to evaluate the presence of occult HBV infection in patients with HCV-related liver cirrhosis (LC) with or without HCC in São Paulo, Brazil. Serum and liver tissue samples from 50 hepatitis B surface antigen-negative patients with HCV-related LC who underwent liver transplantation at the University of São Paulo School of Medicine Hospital from 1993 to 2004 were divided into groups with LC only (N = 33) and with LC plus HCC (N = 17). HBV DNA was assayed for serum and paraffin-embedded liver tissue (tumoral and non-tumoral) using real time PCR and only 1 case with HCC had HBV DNA-positive serum. All liver samples were negative. HCV genotype 3 was detected in 17/39 (43.7%) cases. In conclusion, using a sensitive real time PCR directed to detect HBV variants circulating in Brazil, occult hepatitis B infection was not found among HCV-positive cirrhotic patients and was rarely found among HCV-positive HCC patients. These results are probably related to the low prevalence of HBV infection in our population. Furthermore, we have also shown that HCV genotype 3 is frequently found in Brazilian cirrhotic patients, particularly when they also have HCC. More studies involving a large number of cases should be carried out to confirm these data and to further characterize Brazilian HCV genotype isolates to elucidate genetic features that might be related to its carcinogenic potential.

Assuntos