Venom Profiling of the Insular Species Bothrops alcatraz: Characterization of Proteome, Glycoproteome, and N-Terminome Using Terminal Amine Isotopic Labeling of Substrates.

Bothrops alcatraz, a species endemic to Alcatrazes Islands, is regarded as critically endangered due to its small area of occurrence and the declining quality of its habitat. We recently reported the identification of N-glycans attached to toxins of Bothrops species, showing similar compositions in venoms of the B. jararaca complex (B. jararaca, B. insularis, and B. alcatraz). Here, we characterized B. alcatraz venom using electrophoretic, proteomic, and glycoproteomic approaches. Electrophoresis showed that B. alcatraz venom differs from B. jararaca and B. insularis; however, N-glycan removal revealed similarities between them, indicating that the occupation of N-glycosylation sites contributes to interspecies variability in the B. jararaca complex. Metalloproteinase was the major toxin class identified in the B. alcatraz venom proteome followed by serine proteinase and C-type lectin, and overall, the adult B. alcatraz venom resembles that of B. jararaca juvenile specimens. The comparative glycoproteomic analysis of B. alcatraz venom with B. jararaca and B. insularis indicated that there may be differences in the utilization of N-glycosylation motifs among their different toxin classes. Furthermore, we prospected for the first time the N-terminome of a snake venom using the terminal amine isotopic labeling of substrates (TAILS) approach and report the presence of ∼30% of N-termini corresponding to truncated toxin forms and ∼37% N-terminal sequences blocked by pyroglutamic acid in B. alcatraz venom. These findings underscore a low correlation between venom gland transcriptomes and proteomes and support the view that post-translational processes play a major role in shaping venom phenotypes.

Functional variability of Bothrops atrox venoms from three distinct areas across the Brazilian Amazon and consequences for human envenomings.

Variability in the composition of snake venoms occurs in different taxa and is usually correlated to snake fitness. Here, we compared B. atrox venoms from three different geographic regions across the Brazilian Amazon and found remarkable functional differences particularly between venoms from two populations separated by the Amazon River, in specimens born, raised and maintained under the same conditions at Instituto Butantan serpentary. Venom from Presidente Figueiredo snakes induced stronger dermonecrosis, but was less procoagulant and lethal to mice; these activities were correlated to the presence of a PI-class SVMP and absence of a SVSP in the venom, respectively. Venom from São Bento snakes was more hemorrhagic, killed mice more efficiently, but induced lower signs of dermonecrosis, which was correlated to the higher proportion of SVMPs and the absence of a PI-class SVMP isoform. Belterra snakes, a reference of wild snakes, presented venoms with intermediate phenotypes. Commercial Bothrops antivenom was effective in neutralizing all biological activities evaluated in this study, including dermonecrosis and pro-coagulant, which are relevant for human snakebite accidents by B. atrox. Functional differences correlated to snake fitness may also imply in different symptomatology for B. atrox snakebite patients and deserve special attention from clinical toxicologists.

Coagulotoxicity of Bothrops (Lancehead Pit-Vipers) Venoms from Brazil: Differential Biochemistry and Antivenom Efficacy Resulting from Prey-Driven Venom Variation.

Lancehead pit-vipers (Bothrops genus) are an extremely diverse and medically important group responsible for the greatest number of snakebite envenomations and deaths in South America. Bothrops atrox (common lancehead), responsible for majority of snakebites and related deaths within the Brazilian Amazon, is a highly adaptable and widely distributed species, whose venom variability has been related to several factors, including geographical distribution and habitat type. This study examined venoms from four B. atrox populations (Belterra and Santarém, PA; Pres. Figueiredo, AM and São Bento, MA), and two additional Bothrops species (B. jararaca and B. neuwiedi) from Southeastern region for their coagulotoxic effects upon different plasmas (human, amphibian, and avian). The results revealed inter⁻ and intraspecific variations in coagulotoxicity, including distinct activities between the three plasmas, with variations in the latter two linked to ecological niche occupied by the snakes. Also examined were the correlated biochemical mechanisms of venom action. Significant variation in the relative reliance upon the cofactors calcium and phospholipid were revealed, and the relative dependency did not significantly correlate with potency. Relative levels of Factor X or prothrombin activating toxins correlated with prey type and prey escape potential. The antivenom was shown to perform better in neutralising prothrombin activation activity than neutralising Factor X activation activity. Thus, the data reveal new information regarding the evolutionary selection pressures shaping snake venom evolution, while also having significant implications for the treatment of the envenomed patient. These results are, therefore, an intersection between evolutionary biology and clinical medicine.

Ultrasonographic predictors of esophageal varices.

OBJECTIVE: The aim of this study was to identify ultrasonographic predictors of esophageal varices (EVs) in children and adolescents with chronic liver disease (CLD) and extrahepatic portal venous obstruction (EHPVO). METHODS: This study evaluates 53 patients younger than 20 years with CLD or EHPVO and no history of bleeding or prophylactic EVs treatment. They were divided into 2 groups: group I (35 with CLD) and group II (18 with EHPVO). Splenorenal shunt (SS), gallbladder wall varices, gallbladder wall thickening (GT), and lesser omental thickness (LOT) were compared with the presence of EVs, gastric varices, and portal hypertensive gastropathy (PHG). Univariate (χ² test, Fisher exact test, and Wilcoxon signed rank test) and multivariate (logistic regression) analyses were performed. The area under the receiver operating curve was calculated. RESULTS: EVs were observed in 48.5% of patients with CLD and in 83.3% of patients with EHPVO. SS (P = 0.0329) and LOT (P = 0.0151) predicted EV among patients with CLD. A median of 5.3 mm of LOT was considered a predictor of EVs among these patients. Multivariate analysis showed SS as an independent predictor of EVs in patients with EHPVO (odds ratio 15). Gallbladder varices (P = 0.0245) and GT (P = 0.0289) predicted EVs among patients with EHPVO. PHG occurred more often among patients with CLD who had SS (P = 0.0384) and greater LOT (P = 0.0226). CONCLUSIONS: SS and a greater LOT were indicative of EV among children and adolescents with CLD. Gallbladder varices and GT were indicative of EVs among patients with EHPVO. SS and a greater LOT were indicative of PHG among patients with CLD.

Rectal forceps biopsy procedure in cystic fibrosis: technical aspects and patients perspective for clinical trials feasibility.

BACKGROUND: Measurements of CFTR function in rectal biopsies ex vivo have been used for diagnosis and prognosis of Cystic Fibrosis (CF) disease. Here, we aimed to evaluate this procedure regarding: i) viability of the rectal specimens obtained by biopsy forceps for ex vivo bioelectrical and biochemical laboratory analyses; and ii) overall assessment (comfort, invasiveness, pain, sedation requirement, etc.) of the rectal forceps biopsy procedure from the patients perspective to assess its feasibility as an outcome measure in clinical trials. METHODS: We compared three bowel preparation solutions (NaCl 0.9%, glycerol 12%, mannitol), and two biopsy forceps (standard and jumbo) in 580 rectal specimens from 132 individuals (CF and non-CF). Assessment of the overall rectal biopsy procedure (obtained by biopsy forceps) by patients was carried out by telephone surveys to 75 individuals who underwent the sigmoidoscopy procedure. RESULTS: Integrity and friability of the tissue specimens correlate with their transepithelial resistance (r = -0.438 and -0.305, respectively) and are influenced by the bowel preparation solution and biopsy forceps used, being NaCl and jumbo forceps the most compatible methods with the electrophysiological analysis. The great majority of the individuals (76%) did not report major discomfort due to the short procedure time (max 15 min) and considered it relatively painless (79%). Importantly, most (88%) accept repeating it at least for one more time and 53% for more than 4 times. CONCLUSIONS: Obtaining rectal biopsies with a flexible endoscope and jumbo forceps after bowel preparation with NaCl solution is a safe procedure that can be adopted for both adults and children of any age, yielding viable specimens for CFTR bioelectrical/biochemical analyses. The procedure is well tolerated by patients, demonstrating its feasibility as an outcome measure in clinical trials.

Measurements of CFTR-mediated Cl- secretion in human rectal biopsies constitute a robust biomarker for Cystic Fibrosis diagnosis and prognosis.

BACKGROUND: Cystic Fibrosis (CF) is caused by ∼1,900 mutations in the CF transmembrane conductance regulator (CFTR) gene encoding for a cAMP-regulated chloride (Cl(-)) channel expressed in several epithelia. Clinical features are dominated by respiratory symptoms, but there is variable organ involvement thus causing diagnostic dilemmas, especially for non-classic cases. METHODOLOGY/PRINCIPAL FINDINGS: To further establish measurement of CFTR function as a sensitive and robust biomarker for diagnosis and prognosis of CF, we herein assessed cholinergic and cAMP-CFTR-mediated Cl(-) secretion in 524 freshly excised rectal biopsies from 118 individuals, including patients with confirmed CF clinical diagnosis (n=51), individuals with clinical CF suspicion (n=49) and age-matched non-CF controls (n=18). Conclusive measurements were obtained for 96% of cases. Patients with "Classic CF", presenting earlier onset of symptoms, pancreatic insufficiency, severe lung disease and low Shwachman-Kulczycki scores were found to lack CFTR-mediated Cl(-) secretion (<5%). Individuals with milder CF disease presented residual CFTR-mediated Cl(-) secretion (10-57%) and non-CF controls show CFTR-mediated Cl(-) secretion ≥ 30-35% and data evidenced good correlations with various clinical parameters. Finally, comparison of these values with those in "CF suspicion" individuals allowed to confirm CF in 16/49 individuals (33%) and exclude it in 28/49 (57%). Statistical discriminant analyses showed that colonic measurements of CFTR-mediated Cl(-) secretion are the best discriminator among Classic/Non-Classic CF and non-CF groups. CONCLUSIONS/SIGNIFICANCE: Determination of CFTR-mediated Cl(-) secretion in rectal biopsies is demonstrated here to be a sensitive, reproducible and robust predictive biomarker for the diagnosis and prognosis of CF. The method also has very high potential for (pre-)clinical trials of CFTR-modulator therapies.

Neuromuscular activity of Bothrops alcatraz snake venom in chick biventer cervicis preparations.

Venom (10-100 µg/ml) from Bothrops alcatraz, a pitviper from the Alcatrazes Archipelago off the coast of southeastern Brazil, caused progressive, irreversible neuromuscular blockade in chick isolated biventer cervicis preparations. The venom also inhibited contractures to exogenous ACh (110 µM) and KCl (20 mM), caused myofiber damage and increased creatine kinase release. Commercial bothropic antivenom raised against mainland Bothrops species neutralized the neuromuscular activity, depending on the venom concentration.

Application of real-time PCR stool assay for Helicobacter pylori detection and clarithromycin susceptibility testing in Brazilian children.

BACKGROUND: Helicobacter pylori ClariRes assay is a novel commercially available real-time PCR assay allowing H. pylori detection and clarithromycin susceptibility testing in either gastric biopsy or stool specimens. OBJECTIVE: The aim of this study was to validate the novel biprobe real-time assay in stool specimens from 217 dyspeptic children. METHODS: DNA from gastric biopsies and stool specimens were obtained and submitted to the biprobe real time assay for H. pylori detection and clarithromycin susceptibility testing. RESULTS: The sensitivity, specificity, and test accuracy were 69, 100 and 93.9% for the detection of H. pylori infection and 83.3, 100 and 95.6%, for detection of clarithromycin resistance. CONCLUSION: This assay proved to be appropriate for H. pylori clarithromycin susceptibility testing, particularly in children populations where a high prevalence of clarithromycin-resistant strains is suspected.

Corpo estranho em via aérea / Foreign body in the airway

A aspiração de corpo estranho (ACE) é um acidente grave e potencialmente fatal que pode ocorrer em qualquer fase da vida, mas é muito mais frequente em crianças. O diagnóstico precoce da ACE é essencial, pois o retardo no seu reconhecimento e tratamento pode incorrer em sequela definitiva ou dano fatal. O diagnóstico de ACE é facilmente estabelecido com radiografias simples quando o objeto é radiopaco, mas a maioria dos corpos estranhos aspirados não é radiopaca; aproximadamente 20% das radiografias em pacientes com ACE confirmada são normais. Portanto, uma radiografia normal não exclui a presença de corpo estranho. O passo mais importante no diagnóstico é levantar a hipótese diagnóstica de ACE, sendo a broncoscopia considerada o procedimento padrão ouro no diagnóstico e tratamento da ACE. A broncoscopia deve ser realizada em todos os casos de suspeita de ACE. As taxas de sucesso na extração de corpos estranhos são acima de 98%. Conscientizar pediatras, pais, crianças e cuidadores sobre o fornecimento de alimentos de tamanho e textura apropriados, com base na capacidade do paciente de mastigar e engolir, assim como afastar as crianças de brinquedos e objetos pequenos, inapropriados para sua idade, é essencial na prevenção de ACE.

Foreign body aspiration (FBA) is a serious and potentially fatal accident that can occur at any stage of life but is much more common in children. Early diagnosis of FBA is essential, because delayed recognition and treatment can result in permanent side effects or death.Although the diagnosis of FBA is easily established with routine X-rays when the object is radiopaque, most aspirated foreign bodies are radiolucent. Approximately 20% of patients with confirmed FBA present with normal X-rays. Therefore, a routine X-ray does not exclude FBA. The most important step is to suspect FBA. Bronchoscopy is considered the gold standard procedurein the diagnosis and treatment of FBA.Bronchoscopy should be performed in all suspected cases of FBA. Foreign bodies are successfully extracted in over 98% ofcases. To prevent FBA in children, pediatricians, parents, children, and caregivers should be educated regarding the appropriate types of foods and bite sizes, based on the chewing and swallowing capacities of the child, as well as to keep small objects and age-inappropriate toys away from young children.

High prevalence of clarithromycin resistance and cagA, vacA, iceA2, and babA2 genotypes of Helicobacter pylori in Brazilian children.

We isolated 45 Helicobacter pylori strains from 217 child patients. Resistance to clarithromycin, metronidazole, amoxicillin, and tetracycline was detected in 27%, 13%, 4%, and 0% of strains, respectively. The A2143G mutation was the most prevalent (67%) among clarithromycin-resistant strains. In addition, strain genotyping revealed a significant association between gastritis severity and the simultaneous presence of cagA, vacA s1m1, iceA2, and babA2 genes.

Early diagnostic and endoscopic dilatation for the treatment of acquired upper airway stenosis after intubation in children.

BACKGROUND: Upper airway stenosis (UAS) after endotracheal intubation is a common problem in children. Most literature refers to a surgical treatment for these lesions. Laryngotracheal reconstruction and cricotracheal resection are used for low- and high-grade stenosis, but decannulation is not always possible immediately after surgery. PURPOSE: The aim of this study was to verify the feasibility and results of endoscopic dilatations for treatment of subglottic stenosis. METHOD: The study encompassed a 12-year retrospective analysis of patients treated for UAS in a tertiary center. All children were symptomatic at the time of the endoscopic diagnosis. The stenosis was graded according to the Myer-Cotton criteria. Endoscopic dilatation was initiated immediately after the diagnosis. Children with grade IV stenosis underwent surgery. RESULTS: Children with tracheal stenosis and no involvement of the subglottic area did not respond to endoscopic dilatations and underwent surgery. There were 45 children with grade I stenosis, 12 with grade II, 7 with grade III, and 4 with grade IV lesions. Patients with grade I, II, and III stenosis were all treated by endoscopic dilatations alone and were decannulated when asymptomatic. The average time for decannulation was 18.90 +/- 26.07 months for grade I, 32.5 +/- 27.08 months for grade II, and 27.57 +/- 20.60 months for grade III stenosis (P < .01, for grade II vs grade III). CONCLUSION: Grade I, II, and III subglottic stenoses can be safely managed by early endoscopic dilatations with a high rate of success and low rate of morbidity but require a significantly long period of treatment.

Sex-based individual variation of snake venom proteome among eighteen Bothrops jararaca siblings.

Variation of venom proteome is relevant to basic research, to management of envenoming, and to studies on the evolution of poisonous snakes. In this study, we explored the venom proteomes of eighteen Bothrops jararaca specimens of a single litter born and raised in laboratory. Using electrophoretic techniques and various protocols for measuring the proteolytic activities of these venoms we have detected individual variability and highlighted sex-specific proteomic similarities and differences among sibling snakes. SDS-polyacrylamide gel electrophoresis under non-reducing conditions showed protein bands of approximately 100 kDa specific of male venoms. 2D-electrophoresis showed regions with varying spot complexity between pooled female and male venoms as well as spots that were gender specific. Gelatin zymography showed that female venoms contained proteinases of approximately 25 kDa absent from male venoms. Female venoms were more active than male venoms in degrading fibrinogen whereas on fibrin no significant differences were detected. Among various chromogenic peptide substrates tested, male venoms showed higher amidolytic activity than female venoms on D-Val-Leu-Lys-pNA and D-Phe-Pip-Arg-pNA. Taken together, these results show sex-based differences in the venom proteome of sibling snakes of a single litter raised under controlled conditions which seem to be genetically inherited and imposed by evolutionary forces.

Anéis vasculares na infância: dignóstico e tratamento / Vascular rings in childhood: diagnosis and treatment

Objetivo: apresentar a experiência do Serviço de Cirurgia Pediátrica do Instituto da Criança do HCFMUSP no diagnóstico e tratamento de crianças com anomalias do arco aórtico e definir a importância dos exames complementares para o diagnóstico. Método: estudo retrospectivo de 22 crianças com diagnóstico de compressão traqueoesofágica por anel vascular tratadas no Instituto da Criança, no período de 1985 a 2000, investigando-se dados clínicos pré e pós-operatórios, exames complementares e evolução.Resultados: a anomalia vascular mais freqüente foi artéria inominada direita anômala (10 casos), seguido de duplo arco aórtico (7 casos) e arco aórtico à direita (5 casos). Os sintomas predominantes foram respiratórios (86por cento) e de início precoce (76por cento desde o período neonatal). Entretanto, o diagnóstico definitivo na maioria dos casos (60por cento) só foi estabelecido após l ano de vida. O exame mais importante para o diagnóstico foi o esofagograma. A correção de todas anomalias foi realizada por toracotomia póstero-lateral esquerda. Não ocorreram complicações cirúrgicas. A evolução foi pior nos casos operados mais tardiamente. Todas as crianças permanece- ram sintomáticas por até 6 meses, apesar de significativa melhora no pós-operatório. Conclusão: o diagnóstico de anel vascular deve ser investigado nas crianças com sintomas respiratórios de início precoce e nas "chiadoras'. de difícil controle. O diagnóstico pode ser realizado de forma simples através do esofagograma. Os demais exames de imagem acrescentam poucas informações e são dispensáveis na maioria dos casos. Os sintomas respiratórios podem persistir com menor intensidade por períodos variáveis no pós-operatório

[Vascular rings in childhood: diagnosis and treatment]. / Anéis vasculares na infância: diagnóstico e tratamento.

OBJECTIVE: To present the study carried out by the Pediatric Surgery Department of Instituto da Criança at the Medical School of Universidade de São Paulo regarding the diagnosis and treatment of children with aortic arch abnormalities and to define the role of complementary exams for diagnosis. METHODS: Retrospective study of 22 patients with diagnosis of tracheoesophageal compression treated at Instituto da Criança from 1985 to 2000, analyzing pre- and postoperative clinical data, diagnostic exams and outcome. RESULTS: The most frequent diagnosis was right aberrant innominate artery (10 cases), followed by double aortic arch (7 cases) and right aortic arch (5 cases). Respiratory symptoms (86%) and early manifestation (76% since the neonatal period) were predominant. Nevertheless, most cases (60%) had the definitive diagnosis established only after 1 year of life. The most relevant examination for the diagnosis was the esophagogram. The correction of all the anomalies was carried out through left postero-lateral thoracotomy. There were no surgical complications. The outcome was worse in patients with delayed treatment. All children remained symptomatic for up to 6 months, although they had significant improvement in the postoperative period. CONCLUSIONS: The diagnosis of vascular rings should be considered in children with early respiratory symptoms and in the wheezing baby with difficult control. The diagnosis may be established just through the esophagogram. Other image studies add few information and they are unnecessary in most cases. Less severe symptoms may persist for variable periods.