Glucocorticoid Receptor Gene (NR3C1) Polymorphisms and Metabolic Syndrome: Insights from the Mennonite Population

The regulation of the hypothalamic-pituitary-adrenal (HPA) axis is associated with polymorphisms and the methylation degree of the glucocorticoid receptor gene (NR3C1) and is potentially involved in the development of metabolic syndrome (MetS). In order to evaluate the association between MetS with the polymorphisms, methylation, and gene expression of the NR3C1 in the genetically isolated Brazilian Mennonite population, we genotyped 20 NR3C1 polymorphisms in 74 affected (MetS) and 138 unaffected individuals without affected first-degree relatives (Co), using exome sequencing, as well as five variants from non-exonic regions, in 70 MetS and 166 Co, using mass spectrometry. The methylation levels of 11 1F CpG sites were quantified using pyrosequencing (66 MetS and 141 Co), and the NR3C1 expression was evaluated via RT-qPCR (14 MetS and 25 Co). Age, physical activity, and family environment during childhood were associated with MetS. Susceptibility to MetS, independent of these factors, was associated with homozygosity for rs10482605*C (OR = 4.74, pcorr = 0.024) and the haplotype containing TTCGTTGATT (rs3806855*T_ rs3806854*T_rs10482605*C_rs10482614*G_rs6188*T_rs258813*T_rs33944801*G_rs34176759*A_rs17209258*T_rs6196*T, OR = 4.74, pcorr = 0.048), as well as for the CCT haplotype (rs41423247*C_ rs6877893*C_rs258763*T), OR = 6.02, pcorr = 0.030), but not to the differences in methylation or gene expression. Thus, NR3C1 polymorphisms seem to modulate the susceptibility to MetS in Mennonites, independently of lifestyle and early childhood events, and their role seems to be unrelated to DNA methylation and gene expression.

The Second Highest Prevalence of Celiac Disease Worldwide: Genetic and Metabolic Insights in Southern Brazilian Mennonites

Celiac disease (CD), despite its high morbidity, is an often-underdiagnosed autoimmune enteropathy. Using a modified version of the Brazilian questionnaire of the 2013 National Health Survey, we interviewed 604 Mennonites of Frisian/Flemish origin that have been isolated for 25 generations. A subgroup of 576 participants were screened for IgA autoantibodies in serum, and 391 participants were screened for HLA-DQ2.5/DQ8 subtypes. CD seroprevalence was 1:29 (3.48%, 95% CI = 2.16-5.27%) and biopsy-confirmed CD was 1:75 (1.32%, 95% CI = 0.57-2.59%), which is superior to the highest reported global prevalence (1:100). Half (10/21) of the patients did not suspect the disease. HLA-DQ2.5/DQ8 increased CD susceptibility (OR = 12.13 [95% CI = 1.56-94.20], p = 0.003). The HLA-DQ2.5 carrier frequency was higher in Mennonites than in Brazilians (p = 7 × 10^-6). HLA-DQ8 but not HLA-DQ2.5 carrier frequency differed among settlements (p = 0.007) and was higher than in Belgians, a Mennonite ancestral population (p = 1.8 × 10^-6), and higher than in Euro-Brazilians (p = 6.5 × 10^-6). The glutathione pathway, which prevents reactive oxygen species-causing bowel damage, was altered within the metabolic profiles of untreated CD patients. Those with lower serological positivity clustered with controls presenting close relatives with CD or rheumatoid arthritis. In conclusion, Mennonites have a high CD prevalence with a strong genetic component and altered glutathione metabolism that calls for urgent action to alleviate the burden of comorbidities due to late diagnosis.

Depression and Health Self-perception: Associations Within the Isolated Mennonite Population in South Brazil

The Mennonite population suffered several bottlenecks due to religious/political persecution, increasing the frequency of diseases with a strong genetic component. We evaluated health self-perception in 430 Mennonites from South Brazilian settlements (two rural, one urban), along with life habits, xenobiotic exposure, and chronic ilnesses, using a modified version of the 2013 Brazilian National Health Survey and eight psychometric tests (applied in 2016-2018). Mennonites from rural settlements considered their health worse (P < 0.0001). This was independently associated with any psychiatric disease (OR 3.10, P = 0.037), depression diagnosis (OR 2.39, P = 0.002), spinal pain (OR 1.76, P = 0.015), waist circumference (OR 1.02, P = 0.009) and geographic origin (OR 0.64, P = 0.003). In the multivariate analysis including the scales, independent association also occurred with higher anxiety (ASI-R: OR 6.48, P = 0.014) and depression scores (BDI: OR 6.72, P = 0.008). Thus, a worse health self-perception was unequivocally associated with diagnosed or present depression/anxiety, independent of other contributors, suggesting a strong link between both.

Lack of Association between LCT_rs140433552*CA>del Indel Polymorphism and Lactose Intolerance in a Southern Brazilian Population

BACKGROUND/AIMS

Polymorphisms in the enhancer of the lactase gene (LCT) are strongly associated with lactase persistence, but not always predictive of the phenotype. We investigated a possible association between the regulatory rs140433552*CA>del variant of LCT and lactose intolerance (LI).

METHODS

We genotyped 122 individuals for rs140433552 and rs4988235 (-13910*C>T).

RESULTS

Associations of rs140433552*CA>del with LI depend on -13910*C>T. Homozygous individuals for the C-CA haplotype, as well as C-CA+/C individuals, seem more likely to manifest LI (OR 3.33 [95% CI 1.32-8.35], p = 0.011, and OR 3.93 [95% CI 1.61-9.61], p = 0.003, respectively), while homozygous individuals for the T-CA haplotype seem more likely to be lactose tolerant (OR 0.04 [95% CI 0.002-0.70], p = 8 × 10-4).

CONCLUSIONS

rs140433552*CA>del is not independently associated with LI.

First Report of CR1 Polymorphisms and Soluble CR1 Levels Associated with Late Onset Alzheimer's Disease (LOAD) in Latin America

The CR1 gene has been widely studied in Alzheimer's disease (AD), since its first association with the disease in 2009. Even after 11 years of this discovery, the role of this gene in AD has not yet been fully elucidated and the association of its variants was not validated in Latin American populations. We genotyped five CR1 single nucleotide polymorphisms (SNPs rs6656401, rs3849266, rs2274567, rs4844610, and rs12034383) in up to 162 AD patients and 137 controls through PCR-SSP and iPLEX MassARRAY Platform (Sequenom), and measured soluble CR1 (sCR1) levels in plasma of 40 AD patients and 39 controls with an enzyme-linked immunosorbent assay (ELISA). Homozygosity for haplotype rs3849266*C_rs2274567*A (CA/CA genotype) was associated with susceptibility to AD (OR = 2.94, p = 0.018). Patients presented higher sCR1 levels in plasma than controls (p = 0.038). Furthermore, patients that carry the rs2274567*G allele (p.1208Arg) presented higher sCR1 levels than A/A (p.1208His/His) homozygotes (p = 0.036). This is the first study to validate the association of CR1 polymorphisms with late-onset Alzheimer's disease, as well as to evaluate sCR1 levels in a Latin American population. SNPs present in the regulatory and coding regions of this gene may be playing a key role in the observed association, probably by interfering in Aβ plaques clearance. Inhibition may be due to the increase in local sCR1 levels observed in patients, which may result from polymorphisms leading to larger isoforms of CR1 and/or structural alterations of the protein that makes it less functional, as well as increased vesiculation of the molecules.

Complement Receptor 1 (CR1, CD35) Polymorphisms and Soluble CR1: A Proposed Anti-inflammatory Role to Quench the Fire of "Fogo Selvagem" Pemphigus Foliaceus

Pemphigus foliaceus is an autoimmune disease that is sporadic around the world but endemic in Brazil, where it is known as fogo selvagem (FS). Characterized by autoantibodies against the desmosomal cadherin desmoglein 1, FS causes painful erosions, and crusts that may be widespread. The recognition of antigens, including exposed sugar moieties, activates the complement system. Complement receptor 1 (CR1, CD35), which is responsible for the Knops blood group on erythrocytes (York and McCoy antigens), is also expressed by antigen-presenting cells. This regulates the complement system by removing opsonized antigens, blocking the final steps of the complement cascade. Membrane-bound CR1 also fosters antigen presentation to B cells, whereas soluble CR1 has anti-inflammatory properties. CR1 gene polymorphisms have been associated with susceptibility to complex diseases. In order to investigate the association of CR1 polymorphisms with FS susceptibility, we developed a multiplex sequence-specific assay to haplotype eleven polymorphisms in up to 367 FS patients and 242 controls from an endemic area and 289 from a non-endemic area. We also measured soluble CR1 (sCR1) in the serum of 53 FS patients and 27 controls and mRNA levels in the peripheral blood mononuclear cells of 63 genotyped controls. The haplotypes CR1^*3B2B (with the York antigen–encoded by p.1408Met) and CR1^*3A2A (with p.1208Arg) were associated with protection against FS (OR = 0.57, P = 0.027, and OR = 0.46, P = 0.014, respectively). In contrast, the CR1^*1 haplotype (with the McCoy antigen – encoded by p.1590Glu) was associated with FS susceptibility (OR = 4.97, P < 0.001). Heterozygote rs12034383^*A/G individuals presented higher mRNA expression than homozygotes with the G allele (P = 0.04). The lowest sCR1 levels occurred in patients with active disease before treatment (P = 0.036). Patients in remission had higher levels of sCR1 than did healthy controls (P = 0.013). Among those under treatment, patients with localized lesions also presented higher sCR1 levels than those with generalized lesions (P = 0.0073). In conclusion, the Knops blood group seems to modulate susceptibility to the disease. Furthermore, corticosteroid treatment might increase sCR1 serum levels, and higher levels may play an anti-inflammatory role in patients with FS, limiting the distribution of lesions. Based on these results, we suggest CR1 as a potential new therapeutic target for the treatment of FS.

Long non-coding RNAs in cancer: Another layer of complexity

We review the most well characterized long non-coding RNAs (lncRNAs) with important roles in hallmarks of cancer, additionally including lncRNAs with a higher potential for clinical application. LncRNAs are transcripts larger than 200 nucleotides in length that do not appear to have protein-coding potential, although some of those may produce small functional peptides. These transcripts have attracted significant attention from researchers as a result of their role in genetic regulation, including epigenetic, transcriptional and post-transcriptional regulation, being involved in numerous biological processes, as well as being associated with multifactorial diseases, including tumorigenesis. The hallmarks of cancer include sustaining proliferative signaling, evading growth suppressors, resisting cell death, enabling replicative immortality, inducing angiogenesis and activating invasion/metastasis. Additionally, genome instability, inflammation, reprogramming of energy metabolism and evading immune destruction and lncRNAs are implicated in all hallmarks of cancer. Based on the great number of studies describing lncRNAs associated with diverse aspects of most tumor types, lncRNAs have essential roles in potentially all biological features of cancer cells and show great utility as diagnostic and prognostic markers, as exemplified by PCA3 lncRNA detection in prostate cancer diagnosis.

Surveillance of Arboviruses in Primates and Sloths in the Atlantic Forest, Bahia, Brazil

From 2006 through 2014, we conducted seroepidemiological surveys on non-human primates and sloths to investigate the possible circulation of arboviruses in Bahia Atlantic Forest, Brazil. We collected a total of 196 samples from 103 Leontopithecus chrysomelas, 7 Sapajus xanthosternos, 22 Bradypus torquatus and 7 Bradypus variegatus. Serum samples were tested using neutralization test and hemagglutination inhibition test to detect total antibodies against 26 different arboviruses. The overall prevalence of arboviruses was 36.6% (51/139), with the genus Flavivirus having the highest prevalence (33.1%; 46/139), followed by Phlebovirus (5.0%; 7/139), Orthobunyavirus (4.3%; 6/139) and Alphavirus (0.7%; 1/139). Monotypic reactions suggest that the wild animals were exposed naturally to at least twelve arboviruses. Added results from the neutralization test, animals were exposed to thirteen arboviruses. Most of these viruses are maintained in transmission cycles independent of human hosts, although antibodies against dengue virus serotypes 1, 2 and 3 were found in this study. To our knowledge, this is the first study reporting exposure to arboviruses in L. chrysomelas, S. xanthosternos and B. torquatus. Our results also highlight that the Southern Bahia Atlantic Forest has a variety of vertebrate hosts and potential vectors, which may support the emergence or re-emergence of arboviruses, including those pathogenic to humans.

Complement receptor 1 (CR1, CD35) association with susceptibility to leprosy

Background

Pathophysiological mechanisms are still incompletely understood for leprosy, an urgent public health issue in Brazil. Complement receptor 1 (CR1) binds complement fragments C3b/C4b deposited on mycobacteria, mediating its entrance in macrophages. We investigated CR1 polymorphisms, gene expression and soluble CR1 levels in a case-control study with Brazilian leprosy patients, aiming to understand the role of this receptor in differential susceptibility to the disease.

Methodology

Nine polymorphisms were haplotyped by multiplex PCR-SSP in 213 leprosy patients (47% multibacillary) and 297 controls. mRNA levels were measured by qPCR and sCR1 by ELISA, in up to 80 samples.

Principal findings

Individuals with the most common recombinant haplotype harboring rs3849266*T in intron 21 and rs3737002*T in exon 26 (encoding p.1408Met of the York Yk^a+ antigen), presented twice higher susceptibility to leprosy (OR = 2.43, p = 0.017). Paucibacillary patients with these variants presented lower sCR1 levels, thus reducing the anti-inflammatory response (p = 0.040 and p = 0.046, respectively). Furthermore, the most ancient haplotype increased susceptibility to the multibacillary clinical form (OR = 3.04, p = 0.01) and presented the intronic rs12034383*G allele, which was associated with higher gene expression (p = 0.043), probably increasing internalization of the parasite. Furthermore, there was an inverse correlation between the levels of sCR1 and mannose-binding lectin (initiator molecule of the lectin pathway of complement, recognized by CR1) (R = -0.52, p = 0.007).

Conclusions

The results lead us to suggest a regulatory role for CR1 polymorphisms on mRNA and sCR1 levels, with haplotype-specific effects increasing susceptibility to leprosy, probably by enhancing parasite phagocytosis and inflammation.

The reasons for which some individuals resist Mycobacteria leprae infection, whereas others contract leprosy and only a subgroup of them become severely affected, are still poorly understood. The complement receptor 1 (CR1) serves as a gate for bacterial entry in macrophages, but its importance in the spread of infection and emergence of symptoms is unknown. Despite having many common structural and regulatory variants, the CR1 gene was investigated only once in a leprosy association study in Malawi. In order to fill in this gap, we investigated if CR1 polymorphisms are co-responsible for differential disease susceptibility in 213 leprosy patients and 297 controls, also measuring mRNA and soluble CR1 levels. Associations were dependent on specific combinations of variants in regulatory and coding regions, which were also associated with gene and protein expression. Thus, this study corroborates the importance of the CR1 receptor in the susceptibility to leprosy and is the first to bring information about CR1 polymorphisms in the Brazilian population, as well as to show the relationship between genotypes and mRNA and sCR1 levels.

Latex sensitization in patients with myelomeningocele: contribution of microarray technique

Summary

Background. Microarray technique employing molecular allergens is pointed out as a new method to evaluate allergic patients. Objective. To evaluate if microarray technique (ImmunoCAP-ISAC®; I-ISAC®) is similar to fluorescence enzyme immunoassay (FEIA; ImmunoCAP®) in the diagnosis of latex allergy (specific IgE to latex plus symptoms) and latex sensitization (only antibody) in pediatric (9-mo to 14-yrs) patients with myelomeningocele undergone to surgical repair. Methods. Patients underwent skin prick testing (SPT) to latex and food (prick to prick), and dosage of serum specific IgE to latex and recombinant latex allergens (rHev b 1, rHev b 3, rHev b 5, rHev b 6.01, rHev b 6.02, rHev b 8, rHev b 9, and rHev b 11) by ImmunoCAP® and I-ISAC®. Results. The comparison between the two methods showed high level of concordance considering positive and negative results. A statistically significant correlation for rHev b 3 and rHev b 6.01 for the allergic patients, and for rHev b5 and rHev b6.01 for those sensitized to latex, was observed. I-ISAC® is limited to 5 recombinant latex allergens (rHev b 1, 3, 5, 6.01 and 8). Despite the presence of antibodies against pollens, LTP and profilins (I-ISAC®) in some patients, none of them reported symptoms related with intake of fruits and/or vegetables. Conclusion. Both methods are effective in assisting the diagnosis of latex allergy, but differ in the assessment of sensitized pediatric patients with myelomeningocele. The assessment of latex sensitized patients is more complete using the 8 recombinant latex fractions available for ImmunoCAP®, instead of I-ISAC®.

Effects of whole body vibration on bone mineral density in postmenopausal women: a systematic review and meta-analysis

This systematic review and meta-analysis of randomized controlled trials (RCTs) identified significant effects of whole body vibration (WBV) on bone mineral density (BMD) of the lumbar spine (in the sensitivity analysis and seven subgroup analyses), femoral neck (in one subgroup analysis), and trochanter (four subgroup analyses) in postmenopausal women, but not other measurements of BMD.

INTRODUCTION

Interventions using WBV training have been conducted in postmenopausal women, aimed at increasing BMD; however, the results are contradictory. Our objective is to conduct a systematic review and meta-analysis of RCTs examining WBV effect on BMD.

METHODS

RCTs were considered eligible, with follow-up ≥6 months, which verified the effects of WBV on the BMD of postmenopausal women. The calculations of the meta-analysis were performed through the weighted mean difference between the WBV and control groups, or the WBV and combined training, through the absolute change between pre- and post-intervention in the areal bone mineral density (aBMD) or trabecular volumetric bone mineral density (vBMDt).

RESULTS

Fifteen RCTs were included in the meta-analysis. No differences were observed in the primary analysis. WBV was found to improve aBMD compared with the control group, after exclusion of studies with low quality methodological (lumbar spine), when excluding the studies which combined WBV with medication or combined training (lumbar spine), with the use of low frequency and high magnitude (lumbar spine and trochanter), high frequency and low magnitude (lumbar spine), high cumulative dose and low magnitude (lumbar spine), low cumulative dose and high magnitude (lumbar spine and trochanter), with semi-flexed knee (lumbar spine, femoral neck, and trochanter), and side-alternating type of vibration (lumbar spine and trochanter).

CONCLUSIONS

Despite WBV presenting potential to act as a coadjuvant in the prevention or treatment of osteoporosis, especially for aBMD of the lumbar spine, the ideal intervention is not yet clear. Our subgroup analyses helped to demonstrate the various factors which appear to influence the effects of WBV on BMD, contributing to clinical practice and the definition of protocols for future interventions.

Electromyographic analysis of rectus femoris activity during seated to standing position and walking in water and on dry land in healthy children and children with cerebral palsy

PURPOSE

To analyze rectus femoris activity during seated to standing position and walking in water and on dry land comparing a group of children with the spastic diparesis type of cerebral palsy (CP) and a group of children without neurological disorders.

METHODS

This study included a group of nine children with CP and a control group of 11 children. The study compared the electromyographic activity of the rectus femoris during seated to standing position and walking, in water and on land.

RESULTS

A greater activation of the rectus femoris was observed in the group of children with CP compared with the control group when moving from a seated position to a standing position in water (p=0.0039) and while walking on land (p=0.0014) or in the pool (p=0.007).

CONCLUSION

This study demonstrated the activation of the rectus femoris while walking or standing up from a seated position in water was greater in the group of children with CP. Further studies should be performed to better understand the extent of muscular activation during body immersion in individuals with neurological disorders.

In silico prediction of conserved vaccine targets in Streptococcus agalactiae strains isolated from fish, cattle, and human samples

Streptococcus agalactiae (Lancefield group B; group B streptococci) is a major pathogen that causes meningoencephalitis in fish, mastitis in cows, and neonatal sepsis and meningitis in humans. The available prophylactic measures for conserving human and animal health are not totally effective and have limitations. Effective vaccines against the different serotypes or genotypes of pathogenic strains from the various hosts would be useful. We used an in silico strategy to identify conserved vaccine candidates in 15 genomes of group B streptococci strains isolated from human, bovine, and fish samples. The degree of conservation, subcellular localization, and immunogenic potential of S. agalactiae proteins were investigated. We identified 36 antigenic proteins that were conserved in all 15 genomes. Among these proteins, 5 and 23 were shared only by human or fish strains, respectively. These potential vaccine targets may help develop effective vaccines that will help prevent S. agalactiae infection.

Primate community of the tropical rain forests of Saracá-Taqüera National Forest, Pará, Brazil

Brazil is the richest country in the world in terms of primate species and the Amazonian rain forest is one of the richest biomes containing 15 (ca. 90%) of the Neotropical primate genera. Although considered key elements in conservation strategies, there is only anecdotal information on primates for several protected areas within the region. Here we present new data on the community composition of the primates in the Saracá-Taqüera National Forest (429,600 ha), an actively mined, bauxite rich area, in Pará, Brazil. We used information from the literature, technical reports, museum data, and interviews conducted with agents from the Brazilian Institute of the Environment and Natural Renewable Resources (Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis - IBAMA) and members of the local 'Quilombo' community. In addition, from July 2003 to June 2007, we carried out 19 field trips ranging from 10 to15 days each, amounting to a total effort of 1,230 hours and 1,420 km of censuses, resulting in 1,034 records of eight primate species (Saguinus martinsi, Saguinus midas, Saimiri sciureus, Cebus apella, Pithecia pithecia, Chiropotes sagulatus, Ateles paniscus, and Alouatta macconelli). Two other species (Cebus olivaceus and Aotus trivirgatus) were recorded only indirectly, through interviews and literature data. In all, Alouatta macconelli was the most frequently recorded species (43% of all records); while Saguinus midas and P. pithecia were the least (ca. 0.4 and 0.6% of all records). Based on our results, we discuss group sizes as well as taxonomic problems concerning the genera Pithecia and Chiropotes, for which we registered individuals displaying phenotypic geographical variation and two different forms, respectively. Despite the deforestation inherent in bauxite mining, the Saracá-Taqüera National Forest still has a remarkable richness of primate species. Our study results place this National Forest amongst the richest reserves, in terms of primate species, in the Amazon region.

Collection tubes with or without gel separator did not interfere with detection of rubella virus antibodies IgM and IgG

Rubella infection is an exanthematic disease, with high prevalence in the adult population. The only modality of disease that causes serious consequences is congenital rubella syndrome (CRS), which happens when a pregnant woman seronegative to rubella virus acquires the infection during early pregnancy. Due to the lack of signals and characteristic symptoms of disease, diagnosis of rubella is based essentially on laboratory tests: antibodies detection and/or virus isolation. Results of serologic tests should always be interpreted with caution, because they can be affected by the quality of blood samples, processing and storage of sera, the equipment and reagents used to perform tests, and finally by the technical expertise and training of biologists. The collection tubes with gel seem to facilitate serum separation, but on the other hand gels can retain and consequently decrease antibody titers. Therefore, we decided to investigate whether the use of collection tubes containing gel separator might interfere with rubella virus antibody detection in blood samples from children. We did not observe statistically significant differences with respect to rubella virus antibody detection (immunoglobulin M [IgM] and immunoglobulin G [IgG]) for samples collected in tubes with or without gel separator, from the two evaluated manufacturers.

Autoimmune hepatitis in Brazil: an overview

Autoimmune hepatitis is an immune cell-mediated chronic liver disease of unknown cause that leads, when untreated, to cirrhosis and liver failure. Importantly, this disease affects not only adults but children as well. Genetic susceptibility is clearly important and the major susceptibility factor identified up to now is the HLA-DRB1 locus, but other genes may play a role as well. HLA-DRB1 alleles present in South American patients differ from those found in patients in other parts of the world. In addition, we have recently identified two chromosomal regions where additional susceptibility factors may be found in Brazilian patients, namely, the class III MHC region and the 5q31 region where the IL-4 and IL-13 genes are located. This review discusses the current knowledge of the pathogenesis of this autoimmune disease occurring in the setting of an immune-privileged organ, the liver, and compares the data on gene polymorphisms studied in Brazil and in other parts of the world.

Comparison of Two Commercial Immunoassays for the Detection of Anti‐Rubella IgM and IgG in Pediatric Patients

The only threatening modality of rubella is the Congenital Rubella Syndrome that affects fetuses of women who acquire infection during early pregnancy. Laboratory diagnosis is based on serological parameters. We compared anti-rubella IgM and IgG detection of two commercial immunoassay kits (Abbott and Roche). Although we observed an agreement of 97.8% for IgM and 95.7% for IgG when the categories positive, negative and indeterminate were considered, mean titers of IgG and the absorbance/cut off of IgM were statistically different for both kits, thus corroborating the idea that serological results depend very much on the methodology and must be carefully interpreted.

Peptides of arachnid venoms with insecticidal activity targeting sodium channels

Arachnids have a venom apparatus and secrete a complex chemical mixture of low molecular mass organic molecules, enzymes and polypeptide neurotoxins designed to paralyze or kill their prey. Most of these toxins are specific for membrane voltage-gated sodium channels, although some may also target calcium or potassium channels and other membrane receptors. Scorpions and spiders have provided the greatest number of the neurotoxins studied so far, for which, a good number of primary and 3D structures have been obtained. Structural features, comprising a folding that determines a similar spatial distribution of charged and hydrophobic side chains of specific amino acids, are strikingly common among the toxins from spider and scorpion venoms. Such similarities are, in turn, the key feature to target and bind these proteins to ionic channels. The search for new insecticidal compounds, as well as the study of their modes of action, constitutes a current approach to rationally design novel insecticides. This goal tends to be more relevant if the resistance to the conventional chemical products is considered. A promising alternative seems to be the biotechnological approach using toxin-expressing recombinant baculovirus. Spider and scorpion toxins having insecticidal activity are reviewed here considering their structures, toxicities and action mechanisms in sodium channels of excitable membranes.

Host-parasite relationships of monogeneans in gills ofAstyanax altiparanaeandRhamdia quelenof the São Francisco Verdadeiro River, Brazil

This study investigates the ecology of monogenean gill parasites of Aslyanax altiparanae Garutti & Britski, 2000 and Rhamdia quelen (Quoy & Gaimard, 1824) in a stretch of the Sao Francisco Verdadeiro River, Parana, Brazil. Statistical and ecological indices were used to examine observed levels of parasitism in relation to host and environmental characteristics. A. altiparance and R. quelen had infestation intensities of 2.8 and 23.1 parasites per fish, respectively. The only significant environmental influence was observed at the upstream station for R. quelen. For both host species, parasitized and non-parasitized individuals presented similar weight-ength relationships. Parasitized individuals had dispersed K,, values indicating abnormal conditions. The low levels of parasitism observed in this study suggest that the environment is relatively undisturbed. Additional studies should compare these two species and their respective parasites following completion of the hydroelectric headquarters planned for construction in this stretch of the Sao Francisco Verdoadeiro River.

Butyrylcholinesterase and obesity in individuals with the CHE2 C5+ and CHE2 C5− phenotypes

OBJECTIVE

To investigate the association between butyrylcholinesterase (BChE) activities (total and band specific) and body mass index (BMI) in obese and nonobese individuals, considering other variables (anthropometric, biochemical and hormonal) and the leanness process.

SUBJECTS

Obese (BMI> or =30 kg/m(2); N=181) and nonobese individuals (N=265), classified according to the CHE2 locus phenotypes, with the obese patients being followed-up when submitted to a weight-loss program.

MEASUREMENTS

Anthropometric (weight, height, BMI, waist, waist/hip ratio-WHR, triceps and subscapular skinfolds, percentage of body fat and arterial pressures), hormonal (insulin, estradiol-E(2), triiodothyronine-T(3) and thyroxine-T(4)) and biochemical (glucose, total cholesterol, HDL-C, triglycerides, uric acid, urea, creatinine, sodium, potassium and BChE activities) variables.

RESULTS

Although obese CHE2 C5- individuals presented higher mean BChE activities than their CHE2 C5- controls and diminished mean activities with leanness, similar comparisons did not show any difference in the CHE2 C5+ group. Furthermore, the mean serum potassium values of obese individuals were significantly higher in the CHE2 C5+ than in the CHE2 C5- phenotype. The BChE activities were less related to BMI in obese CHE2 C5- individuals than in their controls. In the CHE2 C5- obese group, significant regression coefficients were found between BChE activity variables and BMI (+), ethnic origin (higher in Euro-Brazilians), sex (higher in males), diastolic pressure (-), triceps skinfold (+), total cholesterol (+), T(3) (+) and E(2) (-). The main findings in the CHE2 C5+ obese group: mean insulin levels decreased with leanness and a significant correlation was detected between the C(5) complex activity and creatinine (+), insulin (-) and WHR (-); a significantly higher frequency of weight loss occurred compared to the CHE2 C5- group.

CONCLUSION

In the present study, different relations between obesity and some of the studied variables were found when CHE2 C5+ and CHE2 C5- individuals were compared.

Midline nasal mass in infancy: a nasal glioma case report

Congenital midline nasal masses are rare anomalies that occur in about one in 20,000-40,000 live births. The most common are dermoid/epidermoid tumors, nasal cerebral heterotopias (nasal gliomas), and nasal encephaloceles; some have an actual or potential central nervous system connection. Nasal gliomas are CNS masses of neurogenic origin which have lost their intracranial connections and present as an obvious external or intranasal mass at birth without associated surgical symptoms. Careful evaluation is required to confirm the diagnosis and appropriate management. The interpretation of CT and MR images can be difficult but is useful in differentiating nasal gliomas from other congenital nasal masses. The presence of a fibrous stalk may be associated with cranial defects and CSF leak. Excisional biopsy allows histopathologic diagnosis and is the definitive treatment. They are benign lesions, and recurrences are rare, so conservative cosmetic surgical techniques should be chosen for gliomas where there is no proven intracranial extension. The authors report an illustrative nasal glioma case in a one-year-old male infant with extranasal and intranasal components, and discuss the therapeutic options.

Association of the CHE2 locus with body mass index and butyrylcholinesterase activity

The butyrylcholinesterase (BChE; EC 3.1.1.8) activities of two electrophoretic bands of the CHE2 C5+ phenotype--C5 and C(OF) (other forms)--were quantified by densitometry in 100 individuals. The activity data suggested that, in addition to determining C5, the CHE2*C5+ allele also increases the level of other BChE forms. Since the relative activity of C5 showed the highest correlation coefficient with weight when compared with the other BChE activity variables (total, absolute C5, and absolute C(OF)), its median activity level was used for the classification of CHE2 C5+ phenotypes (faint and intense). Mean body mass index (BMI) was compared among the CHE2 locus phenotypes-controlled by sex, age, and ethnic group. It was shown that the intense CHE2 C5+ phenotype presents a significantly lower (p < 0.001) mean BMI (23.2) than the other phenotypes (faint CHE2 C5+ = 25.2; CHE2 C5- = 25.4). It seems that the relative COF activity is positively associated with fat storage, since CHE2 C5- and faint CHE2 C5+ phenotypes showed higher mean BMI than the intense CHE2 C5+ phenotype. Our hypothesis is that the presence of C5 in a relatively high proportion leads to less fat storage.

Delay in gallbladder emptying during the perimenopausal period

A pilot study has ascribed an important role in gallbladder motility and emptying to the perimenopausal period. To assess the effect of this period on gallbladder emptying and cholelithogenesis, 25 women in the perimenopausal period without gallbladder disease were submitted to cholangiography and two ultrasound exams. The time for gallbladder emptying and the presence of cholelithiasis were assessed. All patients presented a delay in gallbladder emptying with no relationship to the pre- or postmenopausal period. This finding was not related to lithogenesis. Gallbladder emptying time is longer during the perimenopausal period.

Serologic testing for Trypanosoma cruzi: comparison of radioimmunoprecipitation assay with commercially available indirect immunofluorescence assay, indirect hemagglutination assay, and enzyme-linked immunosorbent assay kits

The radioimmunoprecipitation assay (RIPA) has been used as a confirmatory test in several ongoing and published studies of Trypanosoma cruzi in blood donors in the United States. Despite its use as a confirmatory test, few studies are available comparing RIPA to commercially available serologic test methods. Thus, we compared RIPA with two indirect hemagglutination assays (Biolab Diagnostica SA, São Paulo, Brazil; Hemagen Diagnostics, Inc., Waltham, Mass.) and four different enzyme-linked immunosorbent assays (Abbott Laboratories, Abbott Park, Ill.; Embrabio, São Paulo, Brazil; Organon Teknika, São Paulo, Brazil; and Gull Laboratories, Salt Lake City, Utah) using a panel of 220 serum specimens from Brazilian blood donors with a range of T. cruzi antibody titers as determined by indirect immunofluorescence assay (IFA). A titer of 1:20 was used as the baseline for seropositivity. All IFA-negative serum specimens (n = 19) were nonreactive on all tests. At a titer of 1:20 (n = 9), reactivity rates varied considerably among the tests, with only the RIPA and the Organon and Gull assays identifying reactive specimens. For specimens at a 1:40 titer (n = 35), most assays identified at least 32 of 35 (91%) specimens as reactive, but the Biolab assay only identified 24 (69%). At higher titers (1:80, n = 56; 1:160, n = 101) the assays were comparable, with the exception of the Biolab assay, demonstrating rates of agreement with IFA of >/=98%. Overall, when compared with several other test formats, RIPA demonstrated equivalent or superior rates of agreement with IFA-positive specimens across all titers examined. In particular, at titers of >1:40, the RIPA compared favorably with other test methods currently in use, supporting its application as a confirmatory test, particularly in a research setting.

Frequency of cholelithiasis in alcoholics

In order to determine the frequency of biliary lithiasis in alcoholic patients without signs of hepatic cirrhosis, we submitted 106 male alcoholics (mean age, 42.2 +/- 11.2 years) to ultrasound examination of the biliary system. Cholelithiasis was present in 6 (5.6%). We did not observe any association between the quantity of ethanol consumed and/or the time of consumption and the presence of cholelithiasis. There was no significant difference between the frequency of cholelithiasis in these patients and that found in autopsies carried out on 716 male patients (6%) at the Hospital de Clínicas, Universidade Federal de Uberlândia, during the period 1982 to 1993. Thus, we conclude that in the cases we examined, alcoholism did not represent a risk factor for biliary lithogenesis.

Blood glucose and insulin response to intravenous glucose by patients with chronic Chagas' disease and alcoholism

Blood glucose and insulin responses to intravenous glucose 500 mg/kg in a group of alcoholic chagasic patients (Group I, N = 15) were assessed and compared to those of a group of patients with Chagas' disease without alcoholism (Group II, N = 16), a group of alcoholics without Chagas' disease (Group III, N = 22), and a group of non-alcoholics without Chagas' disease (Group IV, N = 15). Determinations of serum glucose and insulin were done under fasting conditions, 5 and 10 min after the injection of 50% glucose. There was no difference in mean serum glucose levels between groups. Mean serum insulin levels at times 5 and 10 min and for the total integrated response were lower (P < 0.05) in Groups I and II as compared to Group IV; at time 10 min the mean was lower (P < 0.05) in Group III as compared to Group IV. There was a nonsignificant trend for a lower insulinemic response in Group I as compared to Group II. These data suggest denervation of or injury to pancreatic B cell by Chagas' disease.

A case of acute poisoning by methyl demeton in a female 5 months pregnant

During the last decade the number of poisonings by pesticides in Portugal has been steadily rising. Out of 140 patients treated in our Intensive Care Unit (I.C.U.), 86 were male and 54 were female, one of whom was 5 months pregnant. Besides all the care and surveillance required by every case of acute poisoning, pregnant females raise particular problems. Four months later, she gave birth to a normal child. Its follow-up has shown a normal morpho-physiological and psycho-motor development.