Thrombocytopenia as a surrogate marker of hepatosplenic schistosomiasis in endemic areas for Schistosomiasis mansoni

Introduction This study aimed to evaluate whether a low platelet count is a good surrogate marker of hepatosplenic schistosomiasis (HSS) in a rural area of Brazil. A small district in southeastern Brazil, with a population of 1,543 individuals and a 23% prevalence of schistosomiasis, was selected for this investigation. Methods In July 2012, 384 volunteers were subjected to clinical, ultrasonography (US), and laboratory examinations, including stool sample analysis. The HSS patients were classified into four groups: Group 1 consisted of patients with a spleen >13cm and liver fibrosis; Group 2 consisted of patients with a palpable spleen and spleen>13cm measured by US; Group 3 consisted of patients with a spleen >13cm measured by US; and Group 4 consisted of patients with a palpable spleen. Results Eight patients were in Group 1 (2.1%), twenty-one were in Group 2 (5.5%), eight were in Group 3 (2.1%), and eighteen were in Group 4 (4.7%). A significant difference in the mean platelet counts was observed between the patients with and without HSS (p<0.01). Based on the receiver operating characteristic (ROC) curve (platelet count <143,000/mm3), the sensitivity was greater than 92% in all groups, and the specificity varied from 44.4% to 75%. Conclusions We concluded that in endemic areas, thrombocytopenia demonstrates good sensitivity for detecting HSS and may be used as a screening tool to identify patients with HSS.

Histological and endoscopic features of the stomachs of patients with Chagas disease in the era of Helicobacter pylori

Introduction Most studies that have evaluated the stomachs of patients with Chagas disease were performed before the discovery of Helicobacter pylori and used no control groups. This study compared the gastric features of chagasic and non-chagasic patients and assessed whether gastritis could be associated with Chagas disease. Methods Gastric biopsy samples were taken from patients who underwent endoscopy for histological analysis according to the Updated Sydney System. H. pylori infection was assessed by histology, 16S ribosomal ribonucleic acid (rRNA) polymerase chain reaction (PCR), serology and the 13C-urea breath test. Patients were considered H. pylori-negative when all of these diagnostic tests were negative. Clinical and socio-demographic data were obtained by reviewing medical records and using a questionnaire. Results The prevalence of H. pylori infection (70.3% versus 71.7%) and chronic gastritis (92.2% versus 85%) was similar in the chagasic and non-chagasic groups, respectively; such as peptic ulcer, atrophy and intestinal metaplasia. Gastritis was associated with H. pylori infection independent of Chagas disease in a log-binomial regression model. However, the chagasic H. pylori-negative patients showed a significantly higher grade of mononuclear (in the corpus) and polymorphonuclear (PMN) (in the antrum) cell infiltration. Additionally, the patients with the digestive form of Chagas disease showed a significantly lower prevalence of corpus atrophy than those with other clinical forms. Conclusions The prevalence of H. pylori infection and of gastric histological and endoscopic features was similar among the chagasic and non-chagasic patients. Additionally, this is the first controlled study to demonstrate that H. pylori is the major cause of gastritis in patients with Chagas disease.

Ambulatory blood pressure monitoring of patients with heart failure: a new prognosis marker

OBJECTIVE: To evaluate the relationship between 24-hour ambulatory arterial blood pressure monitoring and the prognosis of patients with advanced congestive heart failure. METHODS: We studied 38 patients with NYHA functional class IV congestive heart failure, and analyzed left ventricular ejection fraction, diastolic diameter, and ambulatory blood pressure monitoring data. RESULTS: Twelve deaths occurred. Left ventricular ejection fraction (35.2±7.3%) and diastolic diameter (72.2±7.8mm) were not correlated with the survival. The mean 24-hour (SBP24), waking (SBPw), and sleeping (SBPs) systolic pressures of the living patients were higher than those of the deceased patients and were significant for predicting survival. Patients with mean SBP24, SBPv, and SBPs > or = 105mmHg had longer survival (p=0.002, p=0.01 and p=0.0007, respectively). Patients with diastolic blood pressure sleep decrements (dip) and patients with mean blood pressure dip <=6mmHg had longer survival (p=0.04 and p=0.01, respectively). In the multivariate analysis, SBPs was the only variable with an odds ratio of 7.61 (CI: 1.56; 3704) (p=0.01). Patients with mean SBP<105mmHg were 7.6 times more likely to die than those with SBP > or = 105 mmHg CONCLUSION: Ambulatory blood pressure monitoring appears to be a useful method for evaluating patients with congestive heart failure.

Evaluation of the marker of hypercoagulability prothrombin fragment F 1+2 in patients with mechanical or biological heart valve prostheses

OBJECTIVE: To investigate whether patients with heart valve prostheses and similar International Normalized Ratios (INR) have the same level of protection against thromboembolic events, that is, whether the anticoagulation intensity is related to the intensity of hypercoagulability supression. METHODS: INR and plasma levels of prothrombin fragment 1+2 (F1+2) were assessed in blood samples of 27 patients (7 with mechanical heart valves and 20 with biological heart valves) and 27 blood samples from healthy donors that were not taking any medication. RESULTS: Increased levels of F1+2 were observed in blood samples of 5 patients with heart valve prostheses taking warfarin. These findings reinforce the idea that even though patients may have INRs, within the therapeutic spectrum, they are not free from new thromboembolic events. CONCLUSION: Determination of the hypercoagulability marker F1+2 might result in greater efficacy and safety for the use of oral anticoagulants, resulting in improved quality of life for patients.

Reverse Cardiac Remodeling: A Marker of Better Prognosis in Heart Failure

In heart failure syndrome, myocardial dysfunction causes an increase in neurohormonal activity, which is an adaptive and compensatory mechanism in response to the reduction in cardiac output. Neurohormonal activity is initially stimulated in an attempt to maintain compensation; however, when it remains increased, it contributes to the intensification of clinical manifestations and myocardial damage. Cardiac remodeling comprises changes in ventricular volume as well as the thickness and shape of the myocardial wall. With optimized treatment, such remodeling can be reversed, causing gradual improvement in cardiac function and consequently improved prognosis.

Schistosomiasis mansoni: immunodiagnosis aspects and search for an immunological marker related to therapeutic efficacy

The recent findings on immunodiagnosis of schistosomiasis mansoni have shown that purified Schistosoma mansoni antigens do not provide maximum positivity. Therefore, the authors suggest the use of semi-purified antigens for diagnostic purposes. So far, no serological marker for cured patients as shown by negative stool examination was found. However, a tendency of IgG antibody titre decrease was observed, when egg antigen was used.

Multiple isolates from Aids patients: aspects of an analysis by a genotypic marker and antimicrobial susceptibilities variations

Twenty-one Mycobacterium avium multisolates, from ten human immunodeficiency virus-infected patients, were typed by restriction fragment length polymorphism using as marker the IS1245 and characterized by minimum inhibitory concentration for nine different antibiotics. Two out of four patients harboring multisolates with different fingerprint profile, were therefore considered as having a polyclonal infection, since their isolates were taken from sterile site. This result confirms that polyclonal infection caused by M. avium occurs with a nonnegligenciable frequency. Analyzing the multisolates susceptibility profile of each patient it was observed that most of them were infected with strains having appreciably different antimicrobial susceptibility patterns, no matter what the genotypic pattern of the strains was. These results have strong implication for the treatment of the patients.

Eye colour as a genetic marker for fertility and fecundity of Triatoma infestans (Klug, 1834) Hemiptera, Reduviidae, Triatominae

Eye colour of Triatoma infestans is controlled at a single autosomal locus, with black-eye as the dominant gene and red-eye as the recessive. Inheritance of these characters follows a classical Mendelian system, enabling eye colour to be used as a marker for studies of mating frequency. We found no significant differences in oviposition rates and egg hatching rates irrespective of parental phenotypes. Different mating schedules between red-eye and black-eye parents showed that eye colour did not affect mating competence. Females mated with a single male or with different males together or in succession produced similar numbers of fertile eggs, with the eye colour of the offspring reflecting exposure to the different males. We conclude that although a single mating can provide sufficient sperm for the whole reproductive life of the female, multiple matings can result in balanced assortative sperm usage from the spermatheca.

Dominant character of the molecular marker of a Biomphalaria tenagophila strain (Mollusca: Planorbidae) resistant to Schistosoma mansoni

Biomphalaria tenagophila population from Taim (state of Rio Grande do Sul, Brazil) is totally resistant toSchistosoma mansoni, and presents a molecular marker of 350 bp by polymerase chain reaction and restriction fragment length polymorphism of the entire rDNA internal transcriber spacer. The scope of this work was to determine the heritage pattern of this marker. A series of cross-breedings between B. tenagophila from Taim (resistant) and B. tenagophila from Joinville, state of Santa Catarina (susceptible) was carried out, and their descendants F1 and F2 were submitted to this technique. It was possible to demonstrate that the specific fragment from Taim is endowed with dominant character, since the obtained segregation was typically mendelian.

Pulmonary tuberculosis: evaluation of interferon-gamma levels as an immunological healing marker based on the response to the Bacillus Calmette-Guerin

Tuberculosis (TB) is a disease caused by Mycobacterium tuberculosis whose interaction with the host may lead to a cell-mediated protective immune response. The presence of interferon-g (IFN-gamma) is related to this response. With the purpose of understanding the immunological mechanisms involved in this protection, the lymphoproliferative response, IFN-g and other cytokines like interleukin (IL-5, IL-10), and tumor necrosis factor alpha (TNF-a) were evaluated before and after the use of anti-TB drugs on 30 patients with active TB disease, 24 healthy household contacts of active TB patients, with positive purified protein derivative (PPD) skin tests (induration > 10 mm), and 34 asymptomatic individuals with negative PPD skin test results (induration < 5 mm). The positive lymphoproliferative response among peripheral blood mononuclear cells of patients showed high levels of IFN-g, TNF-a, and IL-10. No significant levels of IL-5 were detected. After treatment with rifampicina, isoniazida, and pirazinamida, only the levels of IFN-g increased significantly (p < 0.01). These results highlight the need for further evaluation of IFN-g production as a healing prognostic of patients treated.

Evaluation of enzyme-linked immunosorbent assay using crude Leishmania and recombinant antigens as a diagnostic marker for canine visceral leishmaniasis

The performances of ELISA assays with different antigen preparations, such as Leishmania amazonensis or L. chagasi lysates and the recombinant antigens rK-39 and rK-26, were compared using sera or eluates from dried blood collected on filter paper to detect anti-Leishmania antibodies in dogs from a visceral leishmaniasis-endemic area in Brazil. Of 115 IFAT-reactive dogs at 1:40 titre, 106 (92.2%) were positive in parasitological exams (skin and/or spleen). These animals were compared to healthy animals (n = 25), negative for IFAT at a titre of 1:40 and parasitological exams. The sensitivities of crude and recombinant antigens were similar and remarkably high for both sera and eluates (97-100%). Specificity was higher than 96% for sera and eluates for different antigens, except for L. chagasi antigen using eluates (88%). Concordance values among the tests were higher either for sera or eluates (J = 0.95-1.00). High concordances were observed between sera and eluates tested with different antigens (kappa = 0.93-0.97). Crude and recombinant antigens identified different clinical phases of canine leishmaniasis. These results show that eluates could be used in canine surveys to identify L. chagasi infection. Recombinant antigens added little when compared to crude antigen in identifying positive dogs. Cross-reactivity with other diseases whose distribution often overlaps VL-endemic areas is a limitation of crude antigen use however.

Identification of a genetic marker associated with the resistance to Schistosoma mansoni infection using random amplified polymorphic DNA analysis

In schistosomiasis, the host/parasite interaction remains not completely understood. Many questions related to the susceptibility of snails to infection by respective trematode still remain unanswered. The control of schistosomiasis requires a good understanding of the host/parasite association. In this work, the susceptibility/resistance to Schistosoma mansoni infection within Biomphalaria alexandrina snails were studied starting one month post infection and continuing thereafter weekly up to 10 weeks after miracidia exposure. Genetic variations between susceptible and resistant strains to Schistosoma infection within B. alexandrina snails using random amplified polymorphic DNA analysis technique were also carried out. The results showed that 39.8% of the examined field snails were resistant, while 60.2% of these snails showed high infection rates.In the resistant genotype snails, OPA-02 primer produced a major low molecular weight marker 430 bp. Among the two snail strains there were interpopulational variations, while the individual specimens from the same snail strain, either susceptible or resistant, record semi-identical genetic bands. Also, the resistant character was ascendant in contrast to a decline in the susceptibility of snails from one generation to the next.

Application of PCR ribotyping and tDNA-PCR for Klebsiella pneumoniae identification

PCR analysis of 16S-23S internal transcribed spacer (PCR ribotyping) and tRNA intergenic spacer (tDNA-PCR) were evaluated for their effectiveness in identification of clinical strains of Klebsiella pneumoniae and differentiation with related species. For this purpose both methods were applied to forty-three clinical isolates biochemically identified as K. pneumoniae subsp. pneumoniae isolated from patients clinical specimens attended at five hospitals in three Brazilian cities. References strains of K. pneumoniae subsp. pneumoniae, K. pneumoniae subsp. ozaenae, K. oxytoca, K. planticola and Enterobacter aerogenes were also analyzed. Both PCR methods showed specific patterns for each species. A conserved PCR ribotype pattern was observed for all clinical K. pneumoniae isolates, while differing from other related analyzed species. tDNA-PCR revealed five distinct patterns among the K. pneumoniae clinical isolates studied, demonstrating a predominant group with 90,6% of isolates presenting the same pattern of K. pneumoniae type strain. Both PCR-based methods were not able to differentiate K. pneumoniae subspecies. On the basis of the results obtained, both methods were efficient to differentiate the Klebsiella species analyzed, as well as E. aerogenes. Meanwhile tDNA-PCR revealed different tRNA arrangements in K. pneumoniae, suggesting intra-species heterogeneity of their genome organization, the polymorphism of the intergenic spacers between 16S and 23S rRNA genes appears to be highly conserved whithin K. pneumoniae clinical isolates, showing that PCR ribotyping can be an useful tool for identification of K. pneumoniae isolates.

Characterization of 23S rRNA domain V mutations in gastric biopsy patients from the eastern Amazon

Resistance of Helicobacter pylori to clarithromycin is characterised by simple point mutations in the 23S ribosomal RNA (rRNA) gene and is responsible for the majority of cases of failure to eradicate this bacterium. In this paper, we characterised the variability of the 23S rRNA gene in biopsies of patients with gastric pathologies in the eastern Amazon (Northern Region of Brazil) using PCR and sequencing. A total of 49 sequences of H. pylori strains were analysed and of those, 75.6% presented nucleotide substitutions: A2142G (3.3%), T2182C (12.9%), G2224A (6.45%), T2215C (61.3%), A2192G (3.3%), G2204C (6.4%) and T2221C (6.4%). Of the mutations identified, four are known mutations related to cases of resistance and 16.1% are not yet described, revealing a high prevalence of mutations in the H. pylori 23S rRNA gene among the strains circulating in the in the eastern Amazon. The high prevalence in individuals with gastric pathologies in the Northern Region of Brazil demonstrates the need for characterising the profile of these strains to provide correct therapy for patients, considering that mutations in this gene are normally associated with resistance to the primary medication used in controlling H. pylori infection.

Phylogenetic analysis of Biomphalaria tenagophila (Orbigny, 1835) (Mollusca: Gastropoda)

Mitochondrial DNA of Biomphalaria tenagophila, a mollusc intermediate host of Schistosoma mansoni in Brazil, was sequenced and characterised. The genome size found for B. tenagophila was 13,722 bp and contained 13 messenger RNAs, 22 transfer RNAs (tRNA) and two ribosomal RNAs (rRNA). In addition to sequencing, the mitochondrial DNA (mtDNA) genome organization of B. tenagophila was analysed based on its content and localization of both coding and non-coding regions, regions of gene overlap and tRNA nucleotide sequences. Sequences of protein, rRNA 12S and rRNA 16S nucleotides as well as gene organization were compared between B. tenagophila and Biomphalaria glabrata, as the latter is the most important S. mansoni intermediate host in Brazil. Differences between such species were observed regarding rRNA composition. The complete sequence of the B. tenagophila mitochondrial genome was deposited in GenBank (accession EF433576). Furthermore, phylogenetic relationships were estimated among 28 mollusc species, which had their complete mitochondrial genome deposited in GenBank, using the neighbour-joining method, maximum parsimony and maximum likelihood bootstrap. B. tenagophila was positioned at a branch close to B. glabrata and Pulmonata molluscs, collectively comprising a paraphyletic group, contrary to Opistobranchia, which was positioned at a single branch and constituted a monophyletic group.