Polymorphisms and haplotypes of TOLLIP and MUC5B are associated with susceptibility and survival in patients with fibrotic hypersensitivity pneumonitis

INTRODUCTION AND OBJECTIVES

Hypersensitivity pneumonitis (HP) is an interstitial lung disease with diverse clinical features that can present a fibrotic phenotype similar to idiopathic pulmonary fibrosis (IPF) in genetically predisposed individuals. While several single nucleotide polymorphisms (SNPs) have been associated with IPF, the genetic factors contributing to fibrotic HP (fHP) remain poorly understood. This study investigated the association of MUC5B and TOLLIP variants with susceptibility, clinical presentation and survival in Portuguese patients with fHP.

MATERIAL AND METHODS

A case-control study was undertaken with 97 fHP patients and 112 controls. Six SNPs residing in the MUC5B and TOLLIP genes and their haplotypes were analyzed. Associations with risk, survival, and clinical, radiographic, and pathological features of fHP were probed through comparisons among patients and controls.

RESULTS

MUC5B rs35705950 and three neighboring TOLLIP variants (rs3750920, rs111521887, and rs5743894) were associated with increased susceptibility to fHP. Minor allele frequencies were greater among fHP patients than in controls (40.7% vs 12.1%, P<0.0001; 52.6% vs 40.2%, P = 0.011; 22.7% vs 13.4%, P = 0.013; and 23.2% vs 12.9%, P = 0.006, respectively). Haplotypes formed by these variants were also linked to fHP susceptibility. Moreover, carriers of a specific haplotype (G-T-G-C) had a significant decrease in survival (adjusted hazard ratio 6.92, 95% CI 1.73-27.64, P = 0.006). Additional associations were found between TOLLIP rs111521887 and rs5743894 variants and decreased lung function at baseline, and the MUC5B SNP and radiographic features, further highlighting the influence of genetic factors in fHP.

CONCLUSION

These findings suggest that TOLLIP and MUC5B variants and haplotypes may serve as valuable tools for risk assessment and prognosis in fibrotic hypersensitivity pneumonitis, potentially contributing to its patient stratification, and offer insights into the genetic factors influencing the clinical course of the condition.

Frequency, spatial distribution, and genetic diversity of Blastocystis among referred individuals to a clinical laboratory: First report of subtype 9 in Brazil

The enteric protist Blastocystis has a worldwide distribution, however its prevalence in the human population is still underestimated, especially in developing countries where proper diagnosis is not performed in the routine of clinical laboratories. In this study, we aimed to assess the frequency, genetic diversity, and spatial distribution of Blastocystis isolates detected in fecal samples referred to a clinical laboratory for routine examination in inner São Paulo State, Brazil. A total of 348 leftover stool samples available for disposal from female and male individuals with age ranging from 3 months to 88 years were analyzed by both microscopic examination and PCR/sequencing of the SSU rRNA gene. The overall frequency of Blastocystis sp. was 31% (108/348), including 20.1% (70/348) and 31% (108/348) by microscopic examination and PCR/sequencing, respectively. Significant association was found only between Blastocystis infection and age, since the highest rate of positive samples was detected among 5-9 years old individuals (p < 0.0001). In addition, spatial distribution revealed a wide distribution of the positive samples, however they were densely concentrated in more populated areas. Seven subtypes were identified, namely ST1 (40.7%), ST2 (9.2%), ST3 (45.3%), ST4 (0.9%), ST6 (1.8%), ST7 (0.9%) and ST9 (0.9%). The intra-subtype analysis revealed a total of 25 different alleles previously reported. Here, the findings lead us to highlight the following aspects: (1) the identification of a ST9 isolate is a relevant finding since it is considered a very rare subtype in human infections as well as this is the first report in Brazil; (2) the high frequency of Blastocystis in fecal samples submitted for examination in a clinical laboratory points to the need to consider its search in routine parasitological examinations, (3) the spatial distribution of Blastocystis infection was not homogeneous but concentrated in more populated areas where the access for population to diagnostic services in healthcare is likely to be easier and, (4) the genetic variability of Blastocystis isolates suggests exposure of inhabitants living in inner municipalities to different sources of contamination involving anthroponotic and zoonotic transmission pathways.

Molecular identification of hookworm species infecting free-roaming and owned dogs from an urban area in inner São Paulo State, Brazil

Dogs are the most popular pet animals worldwide, but on the other hand, they are main hosts of pathogens potentially transmissible to humans. The aim of this study was to assess the occurrence of intestinal parasites in free- roaming and owned dogs in an urban area in southeastern Brazil and to identify the hookworm species infecting them. Faecal samples (80 from free-roaming and 53 from owned dogs) were examined for intestinal parasites using concentration methods. DNA extracted from hookworm microscopy-positive samples were tested by PCR targeting the ITS1-5.8S-ITS2 region and the amplicons retrieved were sequenced. Intestinal parasites were detected in 43.60% (58/133) of the dogs and hookworm infection was found at the highest prevalence rate (38.30%), followed by Toxocara canis (10.50%), Trichuris vulpis (2.25%), Giardia spp. (0.75%) and Cystoisospora spp. (0.75%). Out of the 51 samples positive for hookworm eggs, 26 (50.90%) were successfully amplified and sequenced. Single infections with Ancylostoma caninum and Ancylostoma braziliense were recorded in 18 (69.20%) and two (7.70%) isolates, respectively, and mixed infections were found in the remaining six samples (23.10%). Both species were found infecting free-roaming and owned animals, but A. caninum was more common. These findings highlight the public health relevance of dogs as reservoirs of zoonotic parasites, with emphasis on hookworm species commonly implicated in cutaneous larva migrans (CLM) in poor and deprived areas.

Prevalence and genetic characterization of Dientamoeba fragilis in asymptomatic children attending daycare centers

In order to provide additional data on the prevalence and genetic diversity of Dientamoeba fragilis in human populations, we conducted a study in children from low-income communities in Sao Paulo State, Brazil. Fecal samples from daycare center attendees up to 6 years old (n=156) and staff members (n=18) were submitted to PCR and sequencing of D. fragilis as well as to microscopic examination for the presence of other intestinal parasites. All children assessed were asymptomatic and 10.3% (16/156) were positive for D. fragilis. No worker was found to be positive. An association between Dientamoeba and coinfection with other intestinal parasites was observed. Concerning the genetic diversity, 14 and only two isolates were genotype 1 and genotype 2, respectively. Our findings outline interesting aspects: (1) asymptomatic children as carriers of Dientamoeba in communities in which environmental conditions ensure parasite transmission and, (2) association between Dientamoeba infection in young children and coinfection with other enteric parasites, reinforcing its transmission via the fecal-oral route.

Coexistence of DIPNECH and carotid body paraganglioma: is it just a coincidence?

SUMMARY

We describe the case of a 56 year-old woman with the almost simultaneous appearance of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) and a carotid body paraganglioma. Of interest, 6 years earlier, the patient underwent total thyroidectomy due to papillary thyroid carcinoma and, in the meantime, she was submitted to mastectomy to treat an invasive ductal carcinoma of the breast. In order to explain these lesions, an extensive genetic study was performed. Results showed positivity for the presence of the tumor suppressor gene PALB2, whose presence had already been detected in a niece with breast cancer. The patient underwent different procedures to treat the lesions and currently she is symptom-free over 2 years of follow-up.

LEARNING POINTS

The presence of two rare neoplasms in a single person should raise the suspicion of a common etiology. To the best of our knowledge, this is the first case that shows the coexistence of DIPNECH and paraganglioma. The contribution of the PALB2 gene in the etiology of these rare neoplasms is a possibility.

Genetic analysis of Giardia duodenalis isolates from children of low-income families living in an economically successful region in Southeastern Brazil

Giardia duodenalis is one of the most important and widespread gastrointestinal parasites in the world. Despite its relevance as a causative agent of diarrhea, asymptomatic giardiasis occurs frequently, especially in low resources settings in which children are exposed to many risk factors. Based on microscopic examination and the polymerase chain reaction (PCR) amplification and sequencing of beta-giardin (bg), triose phosphate isomerase (tpi) and glutamate dehydrogenase (gdh) genes, we assessed G. duodenalis occurrence and genetic diversity in isolates of children attending a daycare center and living in low income families, in an economically successful region. Considering both, microscopic examination and PCR/sequencing methods, the overall prevalence of Giardia infection was 51.4%, with the highest frequency in children aged 1-4 years old (p<0.05). Genotyping of 50 isolates revealed that the assemblage A was found in 60% of the samples (30/50), followed by the assemblage B in 38% (19/50) and 2% of mixed-assemblage infections (1/50). At the sub-assemblage level, isolates genotyped as A were AII and among isolates B, BIII and BIV were identified. Both assemblages A and B were detected in children of all age groups, however assemblage A was more prevalent. The detection of anthroponotic assemblages and sub-assemblages (AII, BIII and BIV) reinforces human-to-human transmission, mainly in children of all age groups when they have not yet received toilet training, making them more vulnerable to infection.

Diversity of Blastocystis subtypes in wild mammals from a zoo and two conservation units in southeastern Brazil

The enteric protist Blastocystis is one of the most commonly parasite reported in humans and a variety of animal hosts worldwide. Regarding genetic diversity, at least 17 subtypes (STs) have been identified in mammals and birds, with eight of them (ST1-8) infecting both humans and animals. Recently, isolates from wild mammalian species have been genetically characterized, however data is still scarce, mainly in Latin America. Here, we aimed to verify the occurrence and genetic diversity of Blastocystis in captive wild mammals kept in one zoo and in two units of protection and conservation in southeastern Brazil. A total of 78 fecal samples (14 pooled and 64 individual samples) were recovered from 102 wild mammals of 35 species included in the following orders: Primates, Carnivora, Artiodactyla, Pilosa, Rodentia and Marsupialia. Zoo and units staff were invited to participated but only 16 fecal samples could be screened. Based on the sequence analyses of SSUrDNA gene, out of 29 PCR products from animal samples, 51.7% (15/29) were successfully sequenced and five Blastocystis subtypes were identified as follows: ST1 (2/15; 13.3%), ST2 (2/15; 13.3%), ST3 (4/15; 26.6%), ST5 (2/15; 13.3%) and ST8 (5/14; 33.3%). Only four isolates from humans were sequenced and identified as ST1 (2 isolates), ST2 and ST3. It was observed that Blastocystis infecting non-human primates belong to ST1 and ST2 and mainly to ST3 and ST8, artiodactyls ST5, carnivores ST1 and ST5 and rodents ST1. In addition, this present study reports some interesting findings: (1) 63% (12/19) of Blastocystis isolates from animals and employees belonged to the potentially zoonotic subtypes ST1-ST3; (2) most of these isolates displayed high identity with publicly available DNA sequences from non-human primates and humans, including primate handlers; (3) Blastocystis ST5 was found infecting the northern tiger cat, a native South American felid and one of the species facing a high risk of extinction in Brazil.

Heterozygous TERT gene mutation associated with familial idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic interstitial lung disease of unknown cause that occurs sporadically, but it can also occur in families and so named as Familial Pulmonary Fibrosis (FPF). Some forms of FPF overlaps IPF features, namely the radiological and histological pattern of usual interstitial pneumonia (UIP). Genetic and environmental factors commonly play an important role in the pathogenesis of FPF and the most commonly identified mutations involve the telomerase complex. Here, we report a rare case of FPF in a male at the age of 44, in whom genetic testing showed heterozygous variants for the telomerase reverse transcriptase gene (TERT). Our report highlights the importance of compiling a thorough family history in younger patients identified with UIP serving as a resource for identifying the current and future genetic links to disease. Families with UIP hold a great promise in defining UIP pathogenesis, potentially suggesting targets for the development of future therapies.

Organizing pneumonia revisited: insights and uncertainties from a series of 67 patients

Background: Organizing pneumonia (OP) is classified as an acute/subacute pneumonia according to the American Thoracic Society/European Respiratory Society statement (2013 update). Although its clinical presentation, radiologic and histologic features are well established, data on the relevance of potential causes, corticosteroid doses and length, or management of relapses are based on heterogeneous series of patients. Objectives: The aims of this study were to describe clinical presentation, diagnosis and treatment of OP, explore potential causes, discuss strategies for managing relapses, and analyze prognostic factors. We also discuss our findings in relation to relevant data in the literature. Methods: We performed a cross-sectional study of all patients diagnosed with OP at a tertiary referral center in northern Portugal between 2008 and 2015. Results: Sixty-seven patients were diagnosed with OP over the 7-year study period. Dyspnea and cough were the most common presenting symptoms and approximately 30% of patients were hospitalized at the time of diagnosis. Approximately half of the patients were receiving drugs described as potential causes of OP. Microorganisms were isolated in approximately one-third of patients. Other potential causes identified were hematologic disorders, neoplasms, connective tissue diseases, myelodysplastic syndromes, immunodeficiencies, radiotherapy, and bird exposure. Cryptogenic OP was diagnosed in just 16 patients (23.8%). Corticosteroids were the most common treatment and 11 patients (16.4%) experienced relapse. Conclusions: The findings for this series of patients confirm the extreme variability of the contexts in which OP can occur and suggest that rather than a distinct, homogeneous clinicopathologic entity, OP is a non-specific reaction whose outcomes are dependent on the cause. (Sarcoidosis Vasc Diffuse Lung Dis 2018; 35: 129-138).

Learning curve for transbronchial lung cryobiopsy in diffuse lung disease

INTRODUCTION

Transbronchial lung cryobiopsy (TBLC) is increasingly used in the diagnosis of diffuse lung disease (DLD), but no data have yet been published on the learning curve associated with this technique.

AIM

To evaluate diagnostic yield, lung tissue sample length and area, and procedure-related complications in a cohort of TBLC procedures to define the learning curve and threshold for proficiency.

METHODS

Retrospective analysis of the first 100 TBLCs performed in different segments of the same lobe in patients with suspected DLD. We compared diagnostic yield, sample length and area, and complications between consecutive groups of patients.

RESULTS

The overall diagnostic yield for TBLC was 82%. Median sample length was 5.4mm (IQR, 5-6) and median area was 19.5mm2 (IQR, 13.3-25). Pneumothorax was the most common complication (18%). On comparing the two groups of 50 consecutive patients, a significant difference was found for diagnostic yield (74% vs 90%; p=0.04), sample length (5.0mm [2.5-16] vs 6.0mm [4-12;] p<0.01) and area (17.5mm2 [6-42] vs 21.5mm2 [10-49]; p<0.01). Logarithm regression was applied to median diagnostic yield and sample length and area for groups of 10 consecutive patients to define the learning curve, which plateaued after approximately 70 procedures.

CONCLUSIONS

Our findings suggest that proficiency in TBLC is achieved at approximately the 70th procedure; however they need to be validated in more series and cohorts.

Blastocystis genetic diversity among children of low-income daycare center in Southeastern Brazil

Blastocystis, an unicellular anaerobic eukaryote, is known to be a very common intestinal parasite found in humans and animals fecal samples worldwide. Currently, there is an increasing interest to yield insights into its prevalence and diversity in human populations living in poor and deprived areas. In this study, we describe the prevalence and genetic variability of Blastocystis isolates obtained from daycare center attendees aged 0 to 6years and staff, as well as some children family members and their dogs in a low-income community in São Paulo State, Brazil. A total of 181 stool samples (123 from daycare children, 14 from workers, 44 from household members and 20 from dogs) were submitted to DNA extraction, tested by polymerase chain reaction (PCR) targeting the SSUrDNA gene and the amplicons retrieved were sequenced. The prevalence of Blastocystis was 40.7% (50/123) in children, 28.6% (4/14) in workers and 50% (22/44) in household members. No dog was found positive. Of the 76 PCR products generated, 57 were successfully sequenced. Four subtypes were identified and the most common were ST1 (54.4%) and ST3 (33.3%), followed by ST2 (7.0%) and ST7 (5.3%). The intra-subtype analysis revealed a total of 10 different alleles previously reported. No statistically significant correlation was observed between subtypes and sociodemographic variables analyzed. Here, the following findings must be highlighted: (1) predominance of subtypes 1 and 3, a pattern that has been observed in many populations worldwide; (2) absence of ST4, a common subtype in Europe but rarely detected in South America's human populations and, (3) human infection with ST7, a subtype primarily found in birds but occasionally seen in human infections, raising the possibility of zoonotic transmission.

Tissue iron quantification in chronic liver diseases using MRI shows a relationship between iron accumulation in liver, spleen, and bone marrow

AIM

To investigate iron loading within the liver, pancreas, spleen, and bone marrow using magnetic resonance imaging (MRI) transverse relaxation rate (R2*), in patients with diffuse liver diseases; to evaluate the relationships between iron accumulation in these tissue compartments; and to assess the association between tissue iron overload and the pattern of hepatic cellular iron distribution (hepatocytes versus Kupffer cells).

MATERIAL AND METHODS

Fifty-six patients with diffuse liver diseases had MRI-derived R2* values, using a multi-echo chemical-shift encoded MRI sequence, of the liver, pancreas, spleen, and vertebral bone marrow. All patients had liver biopsy samples scored for hepatic iron grading (0-4) and iron cellular distribution (within hepatocytes only or within both hepatocytes and Kupffer cells).

RESULTS

Liver R2* increased with histological iron grade (R_S=0.58, p<0.001) and correlated with spleen (R_S=0.71, p<0.001) and bone marrow R2* (R_S=0.66, p<0.001), but not with pancreatic R2* (R_S=0.22, p=0.096). Splenic and bone marrow R2* values were also correlated (R_S=0.72, p<0.001). Patients with iron inside Kupffer cells had the highest R2* in liver, spleen and bone marrow.

CONCLUSIONS

Patients with chronic diffuse liver diseases have concomitant hepatic, splenic, and bone marrow iron loading. The highest hepatic iron scores and iron inside Kupffer cells were associated with the highest splenic and bone marrow deposits, suggesting systemic iron accumulation in the mononuclear phagocytic system.

Analysis of sarcoidosis in the Oporto region (Portugal)

BACKGROUND

Sarcoidosis is a systemic granulomatous disease of unknown etiology. Epidemiological studies of different populations are essential because clinical presentation, organ involvement, disease severity, and prognosis vary significantly according to region and population. The aim of this study was to assess epidemiological and clinical characteristics, staging factors, and clinical course in patients with sarcoidosis from a tertiary hospital in Oporto, Portugal.

METHODS

A retrospective analysis of patients with sarcoidosis and at least 2 years of follow-up evaluated at the Centro Hospitalar de São João between 2000 and 2014.

RESULTS

We identified 409 patients with sarcoidosis (females, 58.9%; mean age at diagnosis, 38.9±13.4 years; smokers, 14.4%]. All the patients were diagnosed according to the ERS/ATS/WASOG consensus statement and 64.1% had evidence of noncaseating epithelioid cell granulomas in biopsy specimens. Bronchoalveolar lavage was performed as part of the diagnostic work-up in 289 patients and 90.2% had lymphocytosis (CD4/CD8 ratio ≥3.5 in 60.9% of cases). Exertion dyspnea, cough, and constitutional symptoms were the most common presenting symptoms; 10.1% of patients were asymptomatic, 22.8% had Löfgren syndrome, and 50.5% had extrathoracic involvement. Radiographic stages of disease according to the Scadding criteria were as follows: stage 0 (5.2%), stage I (33.7%), stage II (47.0%), stage III (8.4%), and stage IV (5.7%). Impaired respiratory function was observed in 45.6% patients and was mostly mild. Systemic treatment was administered in 58.6% of cases. Overall, 45.3% of patients experienced disease resolution.

CONCLUSION

The epidemiological and clinical characteristics of this cohort of patients with sarcoidosis from the Oporto region in northern Portugal revealed epidemiological and clinical characteristics that were generally similar to those described in other Western Europe populations and in the US ACCESS study. However, we found a higher proportion of patients who progressed to chronic forms.

Proteolytic activity of excretory/secretory products of Cochliomyia hominivorax larvae (Diptera: Calliphoridae)

Abstract: The protein profiles and proteolytic activity of the excretory secretory products (E/SP) of the first (L1), second (L2) and third (L3) larval stages of Cochliomyia hominivorax were studied in the laboratory. Analysis on the E/SP protein profile was carried out using polyacrylamide gel containing sodium dodecyl sulfate (SDS-PAGE). The E/SP of each larval stage (L1, L2 and L3) treated with protease inhibitors, containing 30μg, 40μg and 50μg of protein, was applied to the 10% polyacrylamide gel. The proteolytic activity of the crude E/SP was analyzed in gels copolymerized with gelatin and by colorimetric assays using azocasein as a substrate, with the characterization of the proteases using synthetic inhibitors. Different protein profiles were observed for the larval instars, with L1 presenting the most complex profile. Nevertheless, various protein bands were observed that were common to all the larval instars. The E/SP of all the instars showed proteolytic activity on gelatin, evidenced by proteolysis zones, predominantly with apparently higher molecular masses in L1, while for L2 and L3 the proteolysis zones could also be observed in regions with lower masses. Tests with protease inhibitors using gelatin as substrate showed that the E/SP of larvae were mainly composed of serine proteases. Additionally, inhibition was observed in L2 E/SP treated previously with EDTA, an inhibitor of metalloproteases. The assays with azocasein revealed a gradual increase of proteolytic activity on this substrate with larval development progress, with the strongest inhibitions being observed after treatments with 3,4-dichloroisocoumarin (DCI) for E/SP of L1, L2 and L3. These results suggest that C. hominivorax larvae produce different proteases, a fact that can be related to the parasite's vital processes for survival, such as penetration into the host's tissues and nutrition during the larval stage.

Molecular characterization of intestinal protozoa in two poor communities in the State of São Paulo, Brazil

Background

Several species of protozoa cause acute or chronic gastroenteritis in humans, worldwide. The burden of disease is particularly high among children living in developing areas of the world, where transmission is favored by lower hygienic standards and scarce availability of safe water. However, asymptomatic infection and polyparasitism are also commonly observed in poor settings. Here, we investigated the prevalence of intestinal protozoa in two small fishing villages, Porto Said (PS) and Santa Maria da Serra (SM), situated along the river Tietê in the State of São Paolo, Brazil. The villages lack basic public infrastructure and services, such as roads, public water supply, electricity and public health services.

Methods

Multiple fecal samples were collected from 88 individuals in PS and from 38 individuals in SM, who were asymptomatic at the time of sampling and had no recent history of diarrheal disease. To gain insights into potential transmission routes, 49 dog fecal samples (38 from PS and 11 from SM) and 28 river water samples were also collected. All samples were tested by microscopy and PCR was used to genotype Giardia duodenalis, Blastocystis sp., Dientamoeba fragilis and Cryptosporidium spp.

Results

By molecular methods, the most common human parasite was Blastocystis sp. (prevalence, 45% in PS and 71% in SM), followed by D. fragilis (13.6% in PS, and 18.4% in SM) and G. duodenalis (18.2% in PS and 7.9% in SM); Cryptosporidium spp. were not detected. Sequence analysis revealed large genetic variation among Blastocystis samples, with subtypes (STs) 1 and 3 being predominant, and with the notable absence of ST4. Among G. duodenalis samples, assemblages A and B were detected in humans, whereas assemblages A, C and D were found in dogs. Finally, all D. fragilis samples from humans were genotype 1. A single dog was found infected with Cryptosporidium canis. River water samples were negative for the investigated parasites.

Conclusions

This study showed a high carriage of intestinal parasites in asymptomatic individuals from two poor Brazilian villages, and highlighted a large genetic variability of Blastocystis spp. and G. duodenalis.

Idiopathic pleuroparenchymal fibroelastosis: a rare but increasingly recognized entity

Idiopathic pleuroparenchymal fibroelastosis (IPPFE) is a recently described rare entity, characterized by pleural and subpleural parenchymal fibrosis and elastosis mainly in the upper lobes. The etiology and pathophysiology are unknown. The prognosis is poor, with no effective therapies other than lung transplantation. IPPFE should be properly identified so that it can be approached correctly. This report describes two clinical cases with clinical imaging and histological features compatible with IPPFE.

Effect of Bifidobacterium animalis on mice infected with Strongyloides venezuelensis

The administration of viable Bifidobacterium animalis was tested to induce resistance against Strongyloides venezuelensis infection in mice. Effects on parasite burden, worm length, egg output, and intestinal mucosal histology were evaluated. The oral administration of B. animalis, strain 04450B, starting 14 days before the inoculation of nematode larvae significantly decreased the worm burden and egg output. In probiotic treated animals, the percent reduction of adult worms in the intestine was of 33% and the reduction of egg production was of 21%, compared with those of the control group. The duodenum villous height and villous/crypt ratio were significantly higher in probiotic-treated mice, indicating that this group could be experiencing less intestinal damage. The present findings revealed that the administration of B. animalis for the amelioration of host response to nematode infections is biologically plausible and could have some potential for impacting public health. Meanwhile, further study is needed to delineate the nature and identity of the factor(s) involved in these beneficial effects.

Molecular typing of Giardia duodenalis isolates from nonhuman primates housed IN a Brazilian zoo

Giardia infections in captive nonhuman primates (NHP) housed at a Brazilian zoo were investigated in order to address their zoonotic potential. Fresh fecal samples were collected from the floors of 22 enclosures where 47 primates of 18 different species were housed. The diagnosis of intestinal parasites after concentration by sedimentation and flotation methods revealed the following parasites and their frequencies: Giardia (18%); Entamoeba spp. (18%); Endolimax nana (4.5%); Iodamoeba spp. (4.5%); Oxyurid (4.5%) and Strongylid (4.5%). Genomic DNA extracted from all samples was processed by PCR methods in order to amplify fragments of gdh and tpi genes of Giardia. Amplicons were obtained from samples of Ateles belzebuth, Alouatta caraya, Alouatta fusca and Alouatta seniculus. Clear sequences were only obtained for the isolates from Ateles belzebuth (BA1), Alouatta fusca (BA2) and Alouatta caraya (BA3). According to the phenetic analyses of these sequences, all were classified as assemblage A. For the tpi gene, all three isolates were grouped into sub-assemblage AII (BA1, BA2 and BA3) whereas for the gdh gene, only BA3 was sub-assemblage AII, and the BA1 and BA2 were sub-assemblage AI. Considering the zoonotic potential of the assemblage A, and that the animals of the present study show no clinical signs of infection, the data obtained here stresses that regular coproparasitological surveys are necessary to implement preventive measures and safeguard the health of the captive animals, of their caretakers and of people visiting the zoological gardens.

In vitro antigiardial activity of the cysteine protease inhibitor E-64

The quest for new antiparasitic alternatives has led researchers to base their studies on insights into biology, host-parasite interactions and pathogenesis. In this context, proteases and their inhibitors are focused, respectively, as druggable targets and new therapy alternatives. Herein, we proposed to evaluate the in vitro effect of the cysteine protease inhibitor E-64 on Giardia trophozoites growth, adherence and viability. Trophozoites (10⁵) were exposed to E-64 at different final concentrations, for 24, 48 and 72 h at 37 °C. In the growth and adherence assays, the number of trophozoites was estimated microscopically in a haemocytometer, whereas cell viability was evaluated by a dye-reduction assay using MTT. The E-64 inhibitor showed effect on growth, adherence and viability of trophozoites, however, its better performance was detected in the 100 µM-treated cultures. Although metronidazole was more effective, the E-64 was shown to be able to inhibit growth, adherence and viability rates by ≥ 50%. These results reveal that E-64 can interfere in some crucial processes to the parasite survival and they open perspectives for future investigations in order to confirm the real antigiardial potential of the protease inhibitors.

Influence of inhibition of extraneuronal uptake and of O-methylation on the hyperglycaemia caused by sympathomimetic amines in depancreatized rats

This study aimed at testing whether the O-methylating system (extraneuronal uptake + O-methylation) modulates, in-vivo, β-adrenoceptor-mediated responses. The influences of U-0521 (3,4-dihydroxymethylpropiophenone, an inhibitor of catechol-O-methyl transferase (COMT)) and hydrocortisone (an inhibitor of extraneuronal uptake) on the hyperglycaemia evoked by isoprenaline and adrenaline were compared. Both inhibitors enhanced the increase of the plasma glucose level induced by either isoprenaline (0·36 nmol kg−1 min−1) or adrenaline (0·55 nmol kg−1 min−1). The enhancement caused by U-0521 developed faster than that caused by hydrocortisone, but was of the same magnitude. This is the first report of supersensitivity to sympathomimetic amines caused by inhibition of either COMT or extraneuronal uptake in-vivo and for a response not involving smooth muscle cells.

Partial characterization of proteolytic activity in Giardia duodenalis purified proteins

This report describes a preliminary characterization of proteolytic activity of proteins isolated from lysate of Giardia trophozoites of an axenic Brazilian strain. Fractions obtained by high-performance liquid chromatography (FPLC) were tested in SDS-polyacrylamide gel for the protein profiles, and the proteases activity was analyzed using gelatin impregnated SDS-PAGE. The proteases characterization was based on inhibition assays employing synthetic inhibitors for cysteine (E-64, IAA), serine (PMSF, TPCK, TLCK, and elastatinal), metalo (EDTA) and aspartic (pepstatin) proteases. Among thirty eluted fractions, polypeptide bands were observed in eight of them, however, proteolytic activity was detected in four ones (F23, F24, F25 and F26). Protein profiles of these fractions showed a banding pattern composed by few bands distributed in the migration region of 45 to < 18 kDa. The zymograms revealed proteolytic activity in all the four fractions assayed, mainly distributed in the migration region of 62 to 35 kDa. Among the profiles, the main pronounced zones of proteolysis were distinguished at 62, 55, 53, 50, 46 and 40 kDa. In inhibition assays, the protease activities were significantly inhibited by cysteine (E-64) and serine proteases (TPCK, TLCK and elastatinal) inhibitors. Gels incubated with other cysteine and serine protease inhibitors, IAA and PMSF, respectively, showed a decrease in the intensity of hydrolysis zones. Indeed, in the assays with the inhibitors EDTA for metalloproteases and pepstatin for aspartic proteases, none inhibition was detected against the substrate. These observations are relevants, especially if we consider that to define the real role of the proteases in host-parasite interaction, the purification of these enzymes for detailed studies may be warranted.

Intragastric balloon for obesity

BACKGROUND

Obesity is one of the major public health problems of modern society. Intragastric balloon (IGB) treatment for obesity has been developed as a temporary aid. Its primary objective is the treatment of obese people, who have had unsatisfactory results in their clinical treatment for obesity, despite of being cared for by a multidisciplinary team, and super obese patients with a higher surgical risk. However, the effects of different IGB procedures compared with conventional treatments and with each other are uncertain.

OBJECTIVES

To assess the effects of intragastric balloon in people with obesity.

SEARCH STRATEGY

Studies were obtained from computerised searches of MEDLINE, EMBASE, LILACS, The Cochrane Library and other electronic databases. Furthermore, reference lists of relevant articles and hand searches of selected journals were performed. Experts in the field were contacted.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials fulfilling the inclusion criteria were used. Short term weight loss is common, so studies were included if they reported measurements after a minimum of four weeks follow-up.

DATA COLLECTION AND ANALYSIS

Data were extracted by one reviewer and checked independently by two reviewers. Two reviewers independently assessed the quality of trials.

MAIN RESULTS

Nine randomised controlled trials involving 395 patients were included. Six out of nine studies had a follow-up of less than one year, the longest study duration was 24 months. Only a third of the analysed studies revealed a low risk of bias. No information was available on quality of life, all-cause mortality and morbidity. Compared with conventional management, IGB did not show convincing evidence of a greater weight loss. On the other hand, complications of intragastric balloon placement occurred, however few of a serious nature. The relative risks for minor complications like gastric ulcers and erosions were significantly raised.

AUTHORS' CONCLUSIONS

Evidence from this review is limited for decision making, since there was large heterogeneity in IGB trials, regarding both methodological and clinical aspects. However, a co-adjuvant factor described by some authors in the loss and maintenance of weight has been the motivation and the encouragement to changing eating habits following a well-organized diet and a program of behavioural modification. The IGB alone and the technique of positioning appear to be safe. Despite the evidence for little additional benefit of the intragastric balloon in the loss of weight, its cost should be considered against a program of eating and behavioural modification.

Giardia duodenalis: protein substrates degradation by trophozoite proteases

The present investigation was undertaken to identify and characterize trophozoite proteases of five axenic strains of Giardia duodenalis isolated in Brazil and the reference strain Portland 1 isolated in the United States. Trophozoite cell lysates of each strain were analysed for the pattern of proteins and for proteolytic activity. Samples were tested in SDS-polyacrylamide gel electrophoresis for the protein profiles, and the detection of proteases in cell lysates was performed using substrate gel electrophoresis [gelatin, collagen, bovine serum albumin (BSA) and haemoglobin] and azocasein assays. Indeed, synthetic inhibitors were included in the assays to characterize the protease classes. Differences on the hydrolysis patterns of protein substrates were observed in relation to the substrate composition as much as the Giardia trophozoite strain. The substrate-containing gels revealed hydrolysis bands with molecular masses ranging from >97 to 20-15 kDa, and most zones were common to the five strains. However, some pronounced differences could be detected in the BTU-11 pattern. Azocasein was also degraded; however, depending on the lysate assayed, the degree of substrate degradation was variable. It was observed that inhibitory effects are substrate-dependent since the activity was predominantly due to cysteine proteases against gelatin, collagen, BSA and azocasein substrates and due to serine against haemoglobin. The presence of aspartic protease and aminopeptidase activity in the lysates was also indicated.

In vitro effects of propolis on Giardia duodenalis trophozoites

In order to improve the current chemotherapy of Giardia infection, potential antigiardial agents have been screened, including natural products. Propolis, a resinous hive product collected by bees, has attracted attention as a useful and popular substance with several therapeutic activities. The present study was carried out aiming to evaluate the in vitro effects of an ethanolic extract of propolis on the growth and adherence of Giardia duodenalis trophozoites. Propolis inhibited the growth of trophozoites and the level of inhibition varied according to the extract concentration and incubation times. The highest reduction of parasite growth was observed in cultures exposed to 125, 250 and 500 microg/ml of propolis, in all incubation periods (24, 48, 72 and 96 h). Growth reduction by 50% was observed in 125 microg/ml propolis-treated cultures, while the concentrations of 250 and 500 microg/ml were able to inhibit growth by more than 60%. Propolis also inhibited parasite adherence and all assayed propolis concentrations promoted the detachment of trophozoites. Light microscope observations revealed changes of the pear-shaped aspect of the cell and reduction of flagellar beating frequency in the great part of the trophozoites. Our results hold the perspective for the utilization of propolis as an antigiardial agent.

In vitro effects of Crotalus durissus terrificus and Bothrops jararaca venoms on Giardia duodenalis trophozoites

Considering the snake venoms' pharmacological properties and chemotherapeutic potential as well as the need for new alternatives for Giardia infection treatment, the present study was carried out aiming to evaluate the in vitro effects of crude Crotalus durissus terrificus and Bothrops jararaca venoms on the growth and adherence of Giardia duodenalis trophozoites. Trophozoites (10(6)) were exposed to serial twofold dilutions of C. durissus terrificus and B. jararaca venoms that ranged from 3.125 to 200 microg/ml and from 5 to 320 microg/ml, respectively. The two venoms inhibited the growth of trophozoites, and the level of inhibition varied according to the assayed concentrations and incubation times. The highest reduction of parasite growth was observed with increasing concentrations of the venoms. No effect on parasite adherence was observed. Light microscope observations revealed changes of the pear-shape aspect of the cell and reduction of flagellar beating frequency in the great part of the trophozoites. This is the first attempt to evaluate the in vitro effects of snake venoms on Giardia trophozoites. The findings stress the need for more investigations and prompt us to perform further studies to identify active principles with antigiardial effect.

Losartan and atenolol on hypertension induced by adenosine receptor blockade

1. The prolonged infusion of 1,3-dipropyl-8-sulfophenylxanthine (DPSPX), a non-selective antagonist of adenosine receptors, induces hypertension, an increase in plasma renin activity and morphological cardiovascular changes. 2. The aim of this work was to evaluate the effects of losartan, a selective AT1 receptor antagonist, and atenolol, a beta-adrenoceptor antagonist, on DPSPX-induced hypertension. 3. Male Wistar rats (250-300 g, n = 4-6) were treated for 1 or 4 weeks with: saline i.p.; DPSPX (90 microg kg(-1) h(-1)) i.p.; losartan (15 mg kg(-1) day(-1)) p.o.; atenolol (25 mg kg(-1) day(-1)) p.o.; DPSPX (90 microg kg(-1) h(-1)) i.p. + losartan (15 mg kg(-1) day(-1)) p.o.; DPSPX (90 microg kg(-1) h(-1)) i.p. + atenolol (25 mg kg(-1) day(-1)) p.o. Blood pressure was measured by the 'tail-cuff' method in conscious animals. Fragments of the mesenteric and tail arteries were processed for morphological study and the mean diameter of the vascular smooth muscle cells was determined. 4. DPSPX increased blood pressure. Losartan and atenolol prevented this rise but had no effect on blood pressure of control rats. DPSPX-treated groups showed hypertrophy of the vascular smooth muscle cells and proliferation of subintimal cells. Losartan but not atenolol prevented these changes. Losartan had no effect on the vascular morphology of control rats, while treatment with atenolol for 4 weeks induced hypertrophy of the vascular smooth muscle cells. 5. Both losartan and atenolol counteract the development of DPSPX-induced hypertension but only losartan prevents the alterations in vascular morphology.

Protease activity in Giardia duodenalis trophozoites of axenic strains isolated from symptomatic and asymptomatic patients

We have examined by gelatin-SDS-PAGE the protease activity in cell lysates of Giardia duodenalis trophozoites of two axenic strains isolated in Brazil from a symptomatic patient (BTU-11) and an asymptomatic carrier (BTU-10), and the reference strain Portland 1 (P1). The proteolysis band patterns showed differences among strains isolated from asymptomatic and symptomatic individuals. The lysate of the strain BTU-10, showed only five hydrolysis bands, while a greater number of bands (10-11 bands) was seen in strains BTU-11 and P1. The protease activity in all lysates was inhibited by cysteine (E-64 and iodoacetamide) and serine proteases (TPCK and TLCK) inhibitors, but not by PMSF and EDTA. In general, the results revealed protease activities in G. duodenalis trophozoites of Brazilian axenic strains and the predominance of cysteine proteinases. It should be stressed the inter-strain difference in hydrolysis band patterns observed between strains isolated from symptomatic patients and the strain obtained from an asymptomatic carrier.

A comparison of AT1 angiotensin II antagonists at pre- and postjunctional angiotensin II receptors of the rat tail artery

A comparison was made of the influence of candesartan, ZD7155, losartan and eprosartan on angiotensin II effects at pre- and postjunctional AT(1) receptors of the rat tail artery. To study the anti-angiotensin II effect at prejunctional receptors, the tissues were preincubated with [(3)H]noradrenaline and then superfused and electrically stimulated (1 Hz, 2 ms, 50 mA, during 5 min); to study the angiotensin II effect at postjunctional receptors, non-cumulative concentration-response curves to angiotensin II were determined in the absence and in the presence of the antagonist. p A(2) values were calculated for competitive antagonists and p D'(2) values for insurmountable antagonists. At the prejunctional level, losartan and eprosartan displayed competitive antagonism with p A(2) values of 6.50 and 8.08, respectively, whereas candesartan and ZD7155 displayed non-competitive antagonism with p D'(2) values of 8.71 and 7.98, respectively. At the postjunctional level, the four antagonists displayed the same kind of antagonism as prejunctionally with p A(2) values for losartan and eprosartan of 8.52 and 8.22, respectively, and p D'(2) values of 10.62 and 9.01, for candesartan and ZD7155, respectively. The ratios between post- and prejunctional potencies were: losartan 101, candesartan 81, ZD7155 11, and eprosartan 1.4. We conclude that, at least functionally, pre- and postjunctional angiotensin II AT(1) receptors are different and propose that the prejunctional receptors in this tissue belong to the AT(1B)-subtype.

Analysis of proteins from membrane and soluble fractions of Giardia duodenalis trophozoites of two Brazilian axenic strains

In the present study, we have analyzed by sodium docecyl sulphate - polyacrilamide gel electrophoresis (SDS-PAGE), immunoblotting and Concanavalin A blotting (Con A blotting) proteins of membrane fractions and soluble fractions obtained from Giardia duodenalis trophozoites of two axenic strains isolated in Brazil from a symptomatic (BTU-11) and an asymptomatic patient (BTU-10), as compared to the reference strain Portland 1. Both Brazilian strains showed a complex and homogeneous electrophoretic pattern of proteins, but some differences could be observed. Several glycoproteins were detected, particularly the proteins of 81, 72, 59 kDa and the protein of 62 kDa in the membrane proteins and cytosol, respectively. Many antigenic components were revealed by anti-Giardia rabbit IgG antibodies in the immunoblotting analysis. Among these components, the membrane protein of 32 kDa and the cytosol protein of 30 kDa could be related to giardin, as previously demonstrated.

Lupus nephritis: a retrospective review of 78 cases from a single center

Lupus nephritis (LN) is a frequent and serious manifestation of systemic lupus erythematosus. However, the outcome has progressively improved in the last 3 decades and this was due to more efficient and early treatment of LN and comorbid situations. The aim of our study was to analyze our experience and outcome in LN, to evaluate clinicopathologic and clinicolaboratory correlations and to search for risk factors for renal and patient survival.

PATIENTS AND METHODS

We conducted a retrospective study of 78 patients with biopsy-proven LN.

RESULTS

Acute renal failure and subnephrotic proteinuria with microhematuria occurred each one in 39.7% of the patients, nephrotic syndrome in 16.7% and nephritic syndrome in 3.8%. The mean serum creatinine at presentation was 1.45 +/- 1.03 mg/dl and the creatinine clearance was 68.2 +/- 40.3 ml/min. Class IV LN existed in 71.8%, Class III in 20.5%, Class V in 6.4% and Class VI in 1.3%. The treatment included steroids and cytotoxic agents in 87.5% of the patients with proliferative LN. Hypertension, serum creatinine and acute renal failure at presentation, as well as significant chronicity on renal biopsy, were significantly correlated with the progression to chronic renal failure in our population. Males were more prone to develop renal flares. 3.8% of the patients died, 9% lost their renal function, 26.9% are in remission, 33.3% still have subnephrotic proteinuria and microhematuria, 7.7% have nephrotic syndrome and 19.2% have chronic renal failure. The mean global follow-up was 102 +/- 74 months and 96.2% of the patients survived. The actuarial renal survival was 96.1% in the first year; 89.9% at 5 years; and 83.7% at 10 and 20 years.

CONCLUSION

We can say that hypertension, serum creatinine and acute renal failure at the onset and significant chronicity on renal biopsy, proved to be risk factors for chronic renal failure in our study population. Male gender was a risk factor for renal flares. The achieved global outcome can be considered a good result.

Detection of anti-Giardia lamblia serum antibody among children of day care centers

OBJECTIVES

To detect anti-Giardia lamblia serum antibodies in healthy children attending public day care centers and to assess serological tests as tools for estimating the prevalence of G. lamblia in endemic areas.

METHODS

Three separate stool specimens and filter paper blood samples were collected from 147 children ranging from 0 to 6 years old. Each stool sample was processed using spontaneous sedimentation and zinc sulfate flotation methods. Blood samples were tested by indirect immunofluorescence (IIF) and enzyme-linked immunosorbent assay (ELISA) for Giardia IgG.

RESULTS AND CONCLUSIONS

Of 147 individuals tested, 93 (63.3%) showed Giardia cysts in their feces. Using IIF and ELISA, serum antibodies were detected in 93 (63.3%) and 100 (68%) samples, respectively. Sensitivity of IIF and ELISA was 82% and 72%, respectively. However, ELISA revealed to be less specific (39%) than IIF (70%). IIF also showed a higher concordance with microscopic examination than ELISA.

Vascular adrenoceptors: an update

The total and regional peripheral resistance and capacitance of the vascular system is regulated by the sympathetic nervous system, which influences the vasculature mainly through changes in the release of catecholamines from both the sympathetic nerve terminals and the adrenal medulla. The knowledge of the targets for noradrenaline and adrenaline, the main endogenous catecholamines mediating that influence, has recently been greatly expanded. From two types of adrenoceptors (alpha and beta), we have now nine subtypes (alpha1A, alpha1B, alpha1D, alpha2A/D, alpha2B, alpha2A/D, beta1, beta2, and beta3) and two other candidates (alpha1L and beta4), which may be conformational states of alpha1A and beta1-adrenoceptors, respectively. The vascular endothelium is now known to be more than a pure anatomical entity, which smoothly contacts the blood and forms a passive barrier against plasma lipids. Instead, the endothelium is an important organ possessing at least five different adrenoceptor subtypes (alpha2A/D, alpha2C, beta1, beta2, and beta3), which either directly or through the release of nitric oxide actively participate in the regulation of the vascular tone. The availability of transgenic models has resulted in a stepwise progression toward the identification of the role of each adrenoceptor subtype in the regulation of blood pressure and fine-tuning of blood supply to the different organs: alpha2A/D-adrenoceptors are involved in the central control of blood pressure; alpha1-(primarily) and alpha2B-adrenoceptors (secondarily) contribute to the peripheral regulation of vascular tone; and alpha2A/D- and alpha2C-adrenoceptors modulate transmitter release. The increased knowledge on the involvement of vascular adrenoceptors in many diseases like Raynaud's, scleroderma, several neurological degenerative diseases (familial amyloidotic polyneuropathy, Parkinson disease, multiple-system atrophy), some kinds of hypertension, etc., will contribute to new and better therapeutic approaches.

Differential effects of eprosartan and losartan at prejunctional angiotensin II receptors

A comparison was made of the influence of losartan and eprosartan on angiotensin II effects at pre- and postjunctional receptors of the canine pulmonary artery and at prejunctional receptors of the rat left ventricle. To study postjunctional contractile responses to angiotensin II, non-cumulative concentration-response curves were determined; to study prejunctional effects of angiotensin II, the tissues were preincubated with [3H]noradrenaline and then superfused and electrically stimulated (1 Hz, 2 ms, 50 mA, 5 min). Postjunctionally, both losartan and eprosartan caused a parallel shift of the concentration-response curve of angiotensin II to the right (pKd of 8.15 and 8.28, respectively). At the prejunctional level, while eprosartan, in concentrations similar to those which were effective postjunctionally (30-100 nM), antagonized the facilitatory effect on noradrenaline release in both the dog pulmonary artery and the rat ventricle, losartan was ineffective in concentrations up to 1 microM. It is concluded that pre-junctional receptors for angiotensin II in the canine pulmonary artery and in the rat left ventricle are different from postjunctional receptors of the canine pulmonary artery. It is proposed that the prejunctional receptors of these tissues are atypical AT1 or "AT1B-like" receptors.