Polymorphisms of CCR5, IL-6, IFN-γ and IL-10 genes in Cuban HIV/AIDS patients.

INTRODUCTION: Genetic studies have shown associations of several single nucleotide polymorphisms (SNP) with different rates of progression and variation in susceptibility to HIV infection. This study aimed to estimate the frequency of ccr5Δ32, IL-6-174G/C, IFN-γ+874T/A and IL-10-1082A/G polymorphisms in Cuban HIV-infected patients and a group of sero-discordant couples to assess their influence on risk and disease progression. METHODS: A cross-sectional study was carried out on 120 subjects registered at the Institute of Tropical Medicine «Pedro Kour¼ (IPK) and the Ameijeiras Hospital from June 2018 until December 2019. The amplification of fragments of the ccr5, IL-6, IFN-γ and IL-10 genes was performed by polymerase chain reaction followed by identification of polymorphisms using the restriction fragment length polymorphism analysis for IL-6 with the restriction enzymes Nla III. Amplification Refractory Mutation System was used for IFN-γ and IL-10 genes. RESULTS: The allelic and genotypic distributions of the genes ccr5, IL-6, IFN-γ and IL-10 did not differ significantly between the two groups. Cell counts and plasma viral load values did not differ significantly between genotypes of the ccr5, IL-6, IFN-γ and IL-10 genes. Only the IL-6 GC genotype was associated with higher viral load values. The combination of alleles of the four considered SNPs showed a highly significant increase in the risk of HIV infection for one of them, but with a very low frequency (<1%). CONCLUSION: This study contributes to evaluating the frequency of these polymorphisms and their influence on biomarkers of the progression of HIV infection in the Cuban HIV-population.

Characterization of kidney complications in patients with sickle cell anemia. / Caracterización de las complicaciones renales en pacientes con anemia de células falciformes.

INTRODUCTION: Sickle cell nephropathy (SCN) is a poorly studied complication of pediatric patients. It appears in different forms, including glomerulopathy, and tubulopathies. OBJECTIVE: To describe acute and chronic renal complications in patients with sickle cell anemia (SCA). PATIENTS AND METHOD: Re trospective study. Pediatric patients with confirmed diagnosis of sickle cell disease were included who had a nephro-urology study. Hemoglobin electrophoresis pattern, presence and type of renal involvement, and presence of cardiac involvement were recorded. Bivariate analysis was perfor med to compare patients with and without SCN. RESULTS: 79 patients were included, 59.5% of them were men, and the most frequent electrophoresis pattern was Hb-SS (60.9%). The SCN oc curred in 70% of patients with an average age of 114 months (RIQ 65-157). The most frequently observed alterations were glomerular hyperfiltration, microalbuminuria, acute kidney injury, ar terial hypertension, and hyposthenuria. In the bivariate analysis, an abnormal echocardiogram result was presented more frequently in patients with SCN (84.8% vs. 54.3% p = 0.01), as well as more frequent use of nephrotoxic drugs (74.5% vs. 54.2% p = 0.07). CONCLUSIONS: Our findings suggest that sickle cell nephropathy may occur at an early age, where glomerular hyperfiltration is very common. Cardiopulmonary complications in patients with SCA may be related to the presence of SCN.

Análisis de la distribución del tiempo en materia de cuidado crítico por profesionales de enfermería mediante TISS-28 / Analysis of the distribution of time in critical care by nursing professionals using TISS-28 / Análise da distribuição do tempo em cuidados intensivos por profissionais de enfermagem usando o TISS-28

RESUMEN Introducción: Hoy en día, las intervenciones terapéuticas son más especializadas y complejas. Se ha identificado que el Therapeutic Intervention Scoring System-28 (TISS-28) es un instrumento adecuado para planear las actividades de enfermería. Objetivo: Determinar mediante la aplicación del instrumento TISS-28 el grado de complejidad de las intervenciones realizadas al brindar cuidados de enfermería a pacientes en estado crítico. Métodos: Estudio descriptivo, 270 pacientes (adultos, pediátricos y neonatales) en estado crítico; se recabó información sociodemográfica tanto del personal de enfermería como de los pacientes a través de un instrumento, se aplicó el TISS-28 para identificar el grado de complejidad de las intervenciones que se le brindaron al paciente. El análisis estadístico fue descriptivo para variables sociodemográficas y laborales, para las acciones realizadas por enfermería mediante niveles de grados de complejidad se hizo uso del análisis bivariado y la regresión logística. Resultados: Las intervenciones brindadas por el personal de enfermería en el servicio de medicina interna en el Grado II es de 9.8 veces más que en el resto de los pacientes, grado III aumenta 68 veces cuando el paciente tiene una sobre estancia hospitalaria. Discusión: Los pacientes que se encuentran en los servicios de cuidados intensivos o quirúrgicos requieren mayores cuidados. Conclusión: El TISS-28 permite predecir el estado del paciente crítico y su evolución. Determina el tiempo de atención requerido según la gravedad de este, además facilita la asignación idónea de enfermera-paciente.

ABSTRACT Introduction: Currently, therapeutic interventions have become more complex and specialized, but the Therapeutic Intervention Scoring System-28 (TISS-28) has been identified as an adequate tool in the planning of the corresponding nursing activities. Objective: To estimate through the Therapeutic Intervention Scoring System-28 (TISS-28) the degree of complexity of the necessary nursing interventions to provide care to patients in critical status. Methods: This is a descriptive study on 270 adult, pediatric, and neonatal patients in critical status. The TISS-28, and nursing and patient sociodemographic instruments were used. A descriptive statistical analysis using the sociodemographic and work-related variables was carried out. Bi-variate analysis and logistic regression were calculated in order to analyze the nursing performance by levels of complexity. Results: The interventions provided by the nursing staff in the internal medicine service in Grade II is 9.8 times more than in the rest of the patients, grade III increases by 68 times when the patient has an excess hospital stay. Discussion: Patients in the intensive care or surgical services require more care. Conclusion: The TISS-28 offers an estimate on the evolution and attention time required by patients in critical status as well as the corresponding ideal nurse-patient ratios.

RESUMO Introdução: Atualmente as intervenções terapêuticas são mais especializadas e complexas, identificou-se que o Therapeutic Intervention Scoring System-28 (TISS-28) é um instrumento adequado para planejar as atividades de enfermagem. Objetivo: Determinar mediante a aplicação do instrumento TISS-28, o grau de complexidade das intervenções realizadas na assistência de cuidados de enfermagem a pacientes em estado crítico. Métodos: Estudo descritivo, 270 pacientes (adultos, pediátricos e neonatais) em estado crítico; foi coletada informação sociodemográfica tanto do pessoal de enfermagem quanto dos pacientes através de um instrumento, aplicou-se o TISS-28 para identificar o grau de complexidade das intervenções que foram prestadas ao paciente. A análise estatística foi descritiva para variáveis sociodemográficas e laborais; a análise bivariada e a regressão logística foi utilizada para as ações realizadas por enfermagem mediante níveis de graus de complexidade. Resultados: As intervenções realizadas pela equipe de enfermagem no serviço de clínica médica do Grau II são 9,8 vezes mais do que no restante dos pacientes, o grau III aumenta em 68 vezes quando o paciente tem um tempo de internação excessivo. Discussão: Os pacientes que se encontram nos serviços de cuidados intensivos ou cirúrgicos requerem maiores cuidados. Conclusão: O TISS-28 permite prever do estado do paciente crítico e sua evolução. Determina o tempo de atenção requerido conforme a gravidade deste, aliás facilita a atribuição idónea de enfermeira-paciente.

Detection and differentiation of Entamoeba histolytica and Entamoeba dispar in clinical samples through PCR-denaturing gradient gel electrophoresis.

Amebiasis is one of the twenty major causes of disease in Mexico; however, the diagnosis is difficult due to limitations of conventional microscopy-based techniques. In this study, we analyzed stool samples using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) to differentiate between Entamoeba histolytica (pathogenic) and E. dispar (non-pathogenic). The target for the PCR amplification was a small region (228 bp) of the adh112 gene selected to increase the sensitivity of the test. The study involved 62 stool samples that were collected from individuals with complaints of gastrointestinal discomfort. Of the 62 samples, 10 (16.1%) were positive for E. histolytica while 52 (83.9%) were negative. No sample was positive for E. dispar. These results were validated by nested PCR-RFLP (restriction fragment length polymorphism) and suggest that PCR-DGGE is a promising tool to differentiate among Entamoeba infections, contributing to determine the specific treatment for patients infected with E. histolytica, and therefore, avoiding unnecessary treatment of patients infected with the non-pathogenic E. dispar.

Quality of life in patients with different constipation subtypes based on the Rome III criteria.

BACKGROUND: Functional constipation and irritable bowel syndrome with constipation are highly prevalent and affect the quality of life of those who suffer from them. AIMS: To evaluate quality of life in patients with functional constipation and irritable bowel disease in accordance with the Rome III criteria, using the PAC-QOL and SF-36 questionnaires. MATERIALS AND METHODS: A cross-sectional study was conducted using self-administered questionnaires. The PAC-QOL, SF-36, and Rome III constipation module questionnaires were applied to patients that complained of constipation at the outpatient clinic of a tertiary care hospital. The constipation subtypes were: functional constipation (no pain), irritable bowel syndrome with constipation (pain and/or discomfort ≥3 days/month), and unclassifiable constipation (pain ≤2 days/month). Data were summarized in proportions, and group comparisons were made between the scores of each of the areas of the PAC-QOL and SF-36 questionnaires using parametric tests (Student's t test and ANOVA). RESULTS: A total of 43 PAC-QOL surveys were analyzed, resulting in cases of irritable bowel syndrome with constipation (14%), functional constipation (37%), and unclassifiable constipation (49%). There were statistically significant differences (P<.05) in Physical discomfort (irritable bowel syndrome with constipation vs. functional constipation and unclassifiable constipation vs. irritable bowel syndrome with constipation), Worries and concerns (irritable bowel syndrome with constipation vs. functional constipation), and Treatment satisfaction (irritable bowel syndrome with constipation vs. functional constipation and unclassifiable constipation vs. irritable bowel syndrome with constipation). A total of 93 SF-36 questionnaires were analyzed, describing cases of irritable bowel syndrome with constipation (23%), functional constipation (27%), and unclassifiable constipation (51%). Lower physical energy was found in relation to irritable bowel syndrome with constipation vs. functional constipation (P<.0221) and unclassifiable constipation (P<.0086), respectively, and there was greater physical pain in the cases of irritable bowel syndrome with constipation vs. unclassifiable constipation (P<.0362). CONCLUSIONS: Differences in quality of life of patients presenting with constipation subtypes were identified using the PAC-QOL and SF-36 questionnaires. The patients that had the irritable bowel syndrome with constipation subtype experienced poorer quality of life in all the evaluated domains.

Trypanosoma cruzi genotyping supports a common source of infection in a school-related oral outbreak of acute Chagas disease in Venezuela.

Trypanosoma cruzi I, a discrete typing unit (DTU) found in human infections in Venezuela and other countries of the northern region of South America and in Central America, has been recently classified into five intra-DTU genotypes (Ia, Ib, Ic, Id, Ie) based on sequence polymorphisms found in the spliced leader intergenic region. In this paper we report the genotype identification of T. cruzi human isolates from one outbreak of acute orally acquired Chagas disease that occurred in a non-endemic region of Venezuela and from T. cruzi triatomine and rat isolates captured at a guava juice preparation site which was identified as the presumptive source of infection. The genotyping of all these isolates as TcId supports the view of a common source of infection in this oral Chagas disease outbreak through the ingestion of guava juice. Implications for clinical manifestations and dynamics of transmission cycles are discussed.

Towards a paradigm shift in the treatment of chronic Chagas disease.

Treatment for Chagas disease with currently available medications is recommended universally only for acute cases (all ages) and for children up to 14 years old. The World Health Organization, however, also recommends specific antiparasite treatment for all chronic-phase Trypanosoma cruzi-infected individuals, even though in current medical practice this remains controversial, and most physicians only prescribe palliative treatment for adult Chagas patients with dilated cardiomyopathy. The present opinion, prepared by members of the NHEPACHA network (Nuevas Herramientas para el Diagnóstico y la Evaluación del Paciente con Enfermedad de Chagas/New Tools for the Diagnosis and Evaluation of Chagas Disease Patients), reviews the paradigm shift based on clinical and immunological evidence and argues in favor of antiparasitic treatment for all chronic patients. We review the tools needed to monitor therapeutic efficacy and the potential criteria for evaluation of treatment efficacy beyond parasitological cure. Etiological treatment should now be mandatory for all adult chronic Chagas disease patients.

Molecular characterization of calcineurin B from the non-virulent Trypanosoma rangeli kinetoplastid indicates high gene conservation.

Calcineurin B, the regulatory subunit of calcineurin, a serine/threonine protein phosphatase, is highly conserved throughout the evolutionary scale including trypanosomatids such as Trypanosoma cruzi, and Leishmania major. Thus, in these flagellates the protein is required for mammalian host cell invasion and virulence and stress responses. With the aim of determining the presence of calcineurin B in Trypanosoma rangeli, a non-virulent trypanosome for mammals, the respective gene was amplified by PCR, cloned and sequenced. Two sequences of 531 bp in length showing a nucleotide polymorphism (314A>C) were obtained in spite of a single-copy gene was revealed by Southern blot. These sequences, probably the alleles from the gene, showed a 79% of identity with those from T. cruzi and clustered as the sister group of this trypanosome species in a Maximum Parsimony analysis. Deduced amino acid sequence comparison with trypanosomatids and other organisms through the phylogenetic scale as well as the obtained protein structural homology model suggested the presence of the four potential EF-hand regions and the corresponding calcium binding sites of the last three of these domains. Having assessed the expression of this protein in T. rangeli epimastigotes, and taking into account the following facts: (i) calcineurin inhibitors have inhibitory effect on the in vitro replication of T. cruzi, (ii) L. major promastigote growth is inhibited by chelating agents, and (iii) T. rangeli does not seem to productively infect mammalian cells, it is hypothesized herein that the function of this protein in T. rangeli is required for epimastigote growth.

Oral transmission of Chagas disease: typing of Trypanosoma cruzi from five outbreaks occurred in Venezuela shows multiclonal and common infections in patients, vectors and reservoirs.

In Venezuela six episodes of oral transmission of Chagas disease (OChD) have been described, being the one reported in 2007 with a total of 103 people infected the largest worldwide. This work shows the use of three molecular markers (mini-exon gene and domains 24Sα and 18S of the ribosomal RNA) to characterize the infecting Trypanosoma cruzi strain of patients, reservoirs and vectors involved in five of the six OChD outbreaks. For this, 28 T. cruzi isolates were characterized by PCR, and the products of these reactions cloned and sequenced to reveal the existence of different TcI SL-IR genotypes. We also describe a new PCR assay able to discriminate between TcIb and TcId parasite populations. In summary, we have identified mostly parasites with the TcId haplotype and multiclonal populations with predominance of haplotype TcId (65.2%). Additionally, populations of haplotypes TcIb, TcIa and mixtures (TcId+TcIb, TcId+TcIa, TcIb+TcIa) are recurrent in samples obtained from children. The analysis of the SL-IR motif showed two clones depicting a different motif that could be an evidence for a possible hybrid haplotype between TcIa and TcIb (haplotype TcIa/Ib). Interestingly, in a single patient haplotype differences between T.cruzi isolates obtained pre and post-treatment were found. In conclusion, our findings show that in order to understand the pathogenic mechanisms involved in the orally acquired Chagas disease there is a need to join efforts to study T. cruzi haplotypes, their tissue tropisms and their susceptibility to chemoteraphy.

Effects of Pepper (Capsicum annuum) Cultivars on the Biology and Life Table Parameters of Myzus persicae (Sulz.) (Hemiptera: Aphididae).

Green peach aphids, Myzus persicae (Sulz.) (Hemiptera: Aphididae), obtained from pepper fields, were colonized on susceptible pepper plants in a growth chamber. The development, survivorship, and life table parameters of the green peach aphid were evaluated on nine peppers cultivars as follows: Almuden, Bilano, Bird, Cabezo, de la Sierra, Eppo, Jaen, Raza, and Yatasto at controlled conditions (20 ± 1°C; about 70% RH; 14h photophase). The development times of immatures ranged from 6.1 days on Yatasto to 11.4 days on Jaen, whereas immature survival was close to 100% on all cultivars. The intrinsic rate of increase (r m ) for green peach aphid on Bilano and Yatasto were the highest. Jackknife estimates of r m varied from 0.281 to 0.174 females/female/day on Yatasto and Jaen, respectively. The mean population generation times (T) on these hosts ranged from 13.7 to 22.7 days. The highest net reproductive rates (R 0 ) were on Bird and Bilano (63.8 and 62.89 females/female/generation, respectively) and the lowest on De la Sierra and Almuden (34.1 and 38.7, respectively). Because of the high coefficient of determination (R (2)) values in Gompertz and Weibul models, survival data from different cultivars had a good fit to both models. The results pointed Jaen, Almuden, and Raza cultivars as the least suitable host plants, indicating that they were the most resistant to M. persicae among the cultivars we tested.

Use of time-of-flight mass spectrometry for large screening of organic pollutants in surface waters and soils from a rice production area in Colombia.

The irrigate district of Usosaldaña, an important agricultural area in Colombia mainly devoted to rice crop production, is subjected to an intensive use of pesticides. Monitoring these compounds is necessary to know the impact of phytosanitary products in the different environmental compartments. In this work, surface water and soil samples from different sites of this area have been analyzed by applying an analytical methodology for large screening based on the use of time-of-flight mass spectrometry (TOF MS) hyphenated to liquid chromatography (LC) and gas chromatography (GC). Several pesticides were detected and unequivocally identified, such as the herbicides atrazine, diuron or clomazone. Some of their main metabolites and/or transformation products (TPs) like deethylatrazine (DEA), deisopropylatrazine (DIA) and 3,4-dichloroaniline were also identified in the samples. Among fungicides, carbendazim, azoxystrobin, propiconazole and epoxiconazole were the most frequently detected. Insecticides such as thiacloprid, or p,p'-DDT metabolites (p,p'-DDD and p,p'-DDE) were also found. Thanks to the accurate-mass full-spectrum acquisition in TOF MS it was feasible to widen the number of compounds to be investigated to other families of contaminants. This allowed the detection of emerging contaminants, such as the antioxidant 3,5-di-tertbutyl-4-hydroxy-toluene (BHT), its metabolite 3,5-di-tert-butyl-4-hydroxy-benzaldehyde (BHT-CHO), or the solar filter benzophenone, among others.

Genome-wide linkage scan of bipolar disorder in a Colombian population isolate replicates Loci on chromosomes 7p21-22, 1p31, 16p12 and 21q21-22 and identifies a novel locus on chromosome 12q.

BACKGROUND/AIMS: Bipolar disorder (BP) is a severe psychiatric illness, characterised by alternating episodes of depression and mania, which ranks among the top ten causes of morbidity and life-long disability world-wide. We have previously performed a whole-genome linkage scan on 6 pedigrees segregating severe BP from the well-characterised population isolate of Antioquia, Colombia. We recently collected genotypes for the same set of 382 autosomal microsatellite markers in 9 additional Antioquian BP pedigrees. Here, we report the analysis of the combined pedigree set. METHODS: Linkage analysis using both parametric and nonparametric approaches was conducted for 3 different diagnostic models: severe BP only (BPI); mood disorders (BPI, BPII and major depression); and psychosis (operationally defined by the occurrence of at least 1 episode of hallucinations and/or delusions). RESULTS AND CONCLUSION: For BPI only, the most interesting result was obtained for chromosome 7p21.1-p22.2 under a recessive model of inheritance (heterogeneity LOD score = 2.80), a region that had previously been linked to BP in a study on Portuguese Island families. For both BPI and mood disorders, nonparametric analyses identified a locus on chromosome 12ct-q14 (nonparametric linkage = 2.55 and 2.35, respectively). This locus has not previously been reported as a candidate region for BP. Additional candidate regions were found on chromosomes 1p22-31 (mood disorders) and 21q21-22 (BPI), 2 loci that have repeatedly been implicated in BP susceptibility. Linkage analysis of psychosis as a phenotype identified candidate regions on chromosomes 2q24-31 and 16p12-q12. The finding on chromosome 16p is noteworthy because the same locus has been implicated by genome-wide association analyses of BP.

Frequency of specific CD8+ T cells for a promiscuous epitope derived from Trypanosoma cruzi KMP-11 protein in chagasic patients.

The K1 peptide is a CD8(+)T cell HLA-A*0201-restricted epitope derived from the Trypanosoma cruzi KMP-11 protein. We have previously shown that this peptide induces IFN-gamma secretion by CD8(+)T cells. The aim of this study was to characterize the frequency of K1-specific CD8(+)T cells in chagasic patients. Nineteen HLA-A2(+)individuals were selected from 50 T. cruzi infected patients using flow cytometry and SSP-PCR assays. Twelve HLA-A*0201(+)noninfected donors were included as controls. Peripheral blood mononuclear cells were stained with HLA-A2-K1 tetramer, showing that 15 of 19 infected patients have K1-specific CD8(+)T cells (0.09-0.34% frequency) without differences in disease stages or severity. Of note, five of these responders were A*0205, A*0222, A*0226, A*0259 and A*0287 after molecular typing. Thus, a phenotypic and functional comparison of K1-specific CD8(+)T cells from non-HLA-A*0201 and HLA-A*0201(+)infected patients was performed. The results showed that both non-HLA-A*0201 and HLA-A*0201(+)individuals have a predominant effector memory CD8(+)T cell phenotype (CCR7-, CD62L-). Moreover, CD8(+)T cells from non-HLA-A*0201 and HLA-A*0201(+)individuals expressed IL-2, IFN-gamma and perforin without any differences. These findings support that K1 peptide is a promiscuous epitope presented by HLA-A2 supertype molecules and is highly recognized by chagasic patients.

Prevalence of Salmonella in a poultry slaughterhouse.

The prevalence of Salmonella on surfaces, water, and broiler chicken (carcasses, parts, viscera, and spoils) taken from a poultry slaughterhouse located in the south of Brazil was studied. The automated mini-VIDAS system (a variation of the basic enzyme-linked immunosorbent assay) was used to screen for the presence of this microorganism in 615 samples, and the traditional culture method was used in 470 samples. We detected Salmonella in the following sampling points by the VIDAS Salmonella test: transport cages (16.7%), boxes (10%), scalding water (16.7%), chilled water (6.7%), carcass before evisceration (6.7%), carcass after chilling (3.3%), fresh breast (3.3%), fresh leg (10%), frozen wing (13.3%), frozen leg (13.3%), intestines (6.7%), skin of breast and leg (10%), and skin of neck (6.7%). Nevertheless, with the traditional culture method we only detected salmonellae in the following sampling points: scalding water (10%), fresh leg (6.7%), frozen wing (10%), skin of breast and leg (20%), and skin of neck (10%). Finally, 5.4% (33 of 615) of the samples analyzed by the VIDAS Salmonella system were positive, whereas the positive percentage with the traditional method was 2.6% (12 of 470). The results showed that transport cages, scalding water, frozen wing, frozen leg, and skin of breast and leg were the sampling points that demonstrated the greatest prevalence.

Immunological and structural characterization of an epitope from the Trypanosoma cruzi KMP-11 protein.

The K1 peptide is an HLA-A*0201-restricted cytotoxic epitope derived from the Trypanosoma cruzi KMP-11 protein, this being the etiological agent of Chagas' disease. This work describes the K1 peptide's secondary structure and its recognition by sera from chagasic patients. Circular dichroism and NMR spectroscopy analysis revealed that the K1 peptide adopts an alpha-helical conformation. Fifty-six percent of individuals had anti-K1 and 86% anti-KMP-11 antibodies by ELISA in the chronic Chagas' group and 28 and 68% in the indeterminate Chagas' group, respectively. By contrast, no reactivity was observed in sera from healthy individuals and tuberculosis patients. Antibody response subclass specificity to the K1 peptide was IgG1 and IgG3. Taken together these results support the idea that the K1 peptide acts as a B-cell-inducer epitope during Chagas' disease.

Evaluation of IFN-gamma production by CD8 T lymphocytes in response to the K1 peptide from KMP-11 protein in patients infected with Trypanosoma cruzi.

The cellular response mediated by MHC class I restricted CD8+ T cells has been shown to be crucial in the control of Chagas disease. The K1 peptide derived from T. cruzi KMP-11 protein has a high binding affinity to the HLA-A*0201 molecule. Nevertheless, it is not known whether this peptide is processed and displayed as an MHC class I epitope during natural infection by T. cruzi. The aim of this study was to evaluate, by ELISPOT assay, the ability of K1 peptide to activate CD8+ T lymphocytes to produce IFN-gamma. Therefore, CD8+ T lymphocytes from 22 HLA-A*0201+ individuals, 12 chronic chagasic patients and 10 uninfected controls, were analysed. The results revealed that two of the chagasic patients had IFN-gamma-secreting CD8+ T cells that were able to respond to K1 peptide with a relative frequency of 110 and 230 per million CD8+ T cells. In contrast, none of HLA-A*0201+ uninfected controls responded to K1 peptide. Responses to HLA-A*0201 restricted peptide from the influenza matrix protein were found in six chagasic patients and four uninfected controls with an average frequency of 175 and 111 cells per million CD8+ T cells, respectively. Moreover, a flow cytometric assay for degranulation showed that chagasic responders had K1-specific cytotoxic CD8+ T cells. It is shown here for the first time that the K1 peptide is efficiently processed, presented and recognized by CD8+ T lymphocytes during the natural course of Chagas disease.

Molecular characterization of the kinetoplastid membrane protein-11 genes from the parasite Trypanosoma rangeli.

Trypanosomatids are early divergent parasites which include several species of medical interest. Trypanosoma rangeli is not pathogenic for humans but shows a high immunological cross-reactivity with Trypanosoma cruzi, the causative agent of Chagas' disease that affects more than 17 million people throughout the world. Recent studies have suggested that T. cruzi KMP-11 antigen could be a good candidate for the induction of immunoprotective cytotoxic responses against T. cruzi natural infection. In the present paper the genes coding for the T. rangeli kinetoplastid membrane protein-11 have been characterized. The results show that the locus encoding this protein is formed by 4 gene units measuring 550 nucleotides in length, organized in tandem, and located in different chromosomes in KP1(+) and KP1(-) strains. The gene units are transcribed as a single mRNA of 530 nucleotides in length. Alignment of the T. rangeli KMP-11 deduced amino acid sequence with the homologous KMP-11 protein from T. cruzi revealed an identity of 97%. Interestingly, the T and B cell epitopes of the T. cruzi KMP-11 protein are conserved in the T. rangeli KMP-11 amino acid sequence.

Genotoxic differences by sex in nasal epithelium and blood leukocytes in subjects residing in a highly polluted area.

We describe differences by sex in genotoxic damage found in a population of medical students exposed to a highly oxidative atmosphere, compared with a control group, measured by the single-cell gel electrophoresis assay and histological changes in nasal epithelium smears. Cells were obtained from the nasal epithelium and blood leukocytes. Higher DNA damage in nasal cells and leukocytes was found in males compared to females and control subjects. The percentage of squamous metaplastic changes in the nasal epithelium was also higher in males compared with females and controls. The co-mutation of normal nasal epithelium by squamous cells might modify its protective function in the nose, increasing the risk of damage to the lower respiratory tract. Although, as medical students, males and females were exposed to the same environment and activity patterns, male genotoxicity damage was higher in control and exposed subjects. More research should be done in order to identify direct or indirect sexual hormone intervention.

Molecular and immunological characterization of L14 ribosomal protein from Leishmania braziliensis.

The isolation and molecular characterization of the gene coding for L14 ribosomal protein from L. braziliensis is described. There are 2 copies of the gene per haploid genome, repeated in a head-to-tail tandem orientation and located in a single chromosome of approximately 950 kb. Northern blot analyses indicate the presence of a single transcript of 0.95 kb which is up-regulated when parasites reach the stationary growth phase. L. braziliensis L14 gene codes for a 175 amino acid long polypeptide showing 75-83% sequence identity with L14 proteins from trypanosomatids and approximately 25% with its counterparts from higher eukaryotic organisms. L14 ribosomal proteins from trypanosomatids and higher eukaryotes share along their molecules a similar distribution pattern of theoretically functional domains. L. braziliensis L14 recombinant protein is not recognized by sera from cutaneous leishmaniasis patients. Immunization of mice with one dose of L14 recombinant protein and a second dose of L14 protein covalently linked to the HSP70 from Trypanosoma cruzi induces a high antibody level against this L14 protein, which is mostly of the IgG2a subtype, as well as a strong increase in splenocyte proliferation index.