"Two-step" technique with OsiriX™ to evaluate feasibility of C2 pedicle for surgical fixation

BACKGROUND

Surgical treatment of craniovertebral junction pathology has evolved considerably in recent decades with the implementation of short atlanto-axial fixation techniques, notwhithstanding increasing neurovascular risks. Also, there is strong evidence that fixation of C2 anatomical pedicle has the best biomechanical profile of the entire cervical spine. However, it is often difficult and misleading, to evaluate anatomical bony and vascular anomalies using the three orthogonal planes (axial, coronal, and sagittal) of CT.

OBJECTIVES

The authors describe an innovative and simple technique to evaluate the feasibility of C2 pedicle for surgical screw fixation using preoperative planning with the free DICOM (Digital Imaging and Communications in Medicine) software OsiriX™.

MATERIALS AND METHODS

The authors report the applicatin of this novel technique in 5 cases (3 traumatic, 1 Os Odontoideum, and 1 complex congenital malformation) collected from our general case series of the Department in the last 5 years.

RESULTS

In this proof of concept study, the pre-operative analysis with the two-step tecnique was detrimental for choosing the surgical tecnique. Detailed post-operative analysis confirmed correct position of C2 screws without cortical breach. There were no complications or mortality reported.

CONCLUSION

This two-step technique is an easy and reliable way to determine the feasibility of C2 pedicle for surgical fixation. The detailed tridimensional radiological preoperative evaluation of craniovertebral junction anatomy is critical to the sucess and safety of this surgeries, and can avoid, to certain degree, expensive intra-operative tridimensional imaging facilities.

Autoimmune hepatitis: trust in transaminases

A rational and appropriate evaluation of liver biochemical tests is essential, given the increased number of abnormal laboratory results in asymptomatic patients. Critical judgement allows early diagnosis in the absence of typical clinical signs. Autoimmune hepatitis is a rare disease with high clinical variability. We present a child investigated for unexplained increase in aminotransferases, discovered accidentally 2 months earlier in a standard laboratory panel approach. She was asymptomatic and no physical signs of chronic or acute liver disease were found. Laboratory investigation showed hypergammaglobulinaemia with selective elevation of IgG and a positive anti-liver cytosol type 1. Severe interface hepatitis was found on liver biopsy and treatment was initiated with steroids and azathioprine with good response. This case highlights the importance of trusting in any serum aminotransferase abnormality, even in asymptomatic children and emphasises the value of clinical suspicion and specific immunosuppressive therapy in prognosis.

Living versus cadaveric-donor renal transplant recipients: a comparison on sexual function

Erectile dysfunction is experienced by 50% of men with end-stage renal disease (ESRD) and uremia. The origin of this dysfunction is multifactorial. The aim of this study was to compare living donor versus cadaveric donor transplant recipients regarding male sexual function. Seventy-seven sexually active male kidney transplant recipients (44 from living donors; 33 from cadaveric donors) were randomly selected from our single-center prospective database of 2016 renal transplants. Epidemiological and clinical data were collected between June 2010 and June 2011. Male sexual function was evaluated with the International Index of Erectile Function questionnaire (IIEF-15). We assessed the prevalence of male sexual dysfunction according to established cutoff points for each of the IIEF-15 domains. Mann-Whitney and Pearson's chi- square statistical tests were used to compare continuous and categorical variables, respectively. The median age at the time of completion of the questionnaires was 43 and 51 years (P = .003) with median times from transplantation was of 36 and 42 months for living donor and cadaveric donor recipients, respectively (P = .31). Median durations of ESRD before surgery were 17.5 and 57 months for living donor and cadaveric donor recipients, respectively (P < .001). Living donor and cadaveric donor recipients had median creatinine clearance values of 55 and 57 mL/min, respectively (P = .44). Median time after renal transplantation for first sexual intercourse was 1 and 2 months for living donor and cadaveric donor recipients, respectively (P = .35). Median body mass indices for living donor and cadaveric donor recipients were 24.8 and 24, respectively (P = .31). Regarding sexual function domains, there were significant differences only for intercourse satisfaction. In our cohort, living donor recipients tended to be younger, have shorter time of ESRD, and less incidence of hypertension or diabetes mellitus but with greater tobacco use. In conclusion, living donor transplantation exerted a favorable impact on sexual function.

Functional graph alterations in schizophrenia: a result from a global anatomic decoupling?

During rest, the brain exhibits slow hemodynamic fluctuations (<0.1 Hz) that are correlated across spatially segregated brain regions, defining functional networks. Resting-state functional networks of people with schizophrenia were found to have graph properties that differ from those of control subjects. Namely, functional graphs from patients exhibit reduced small-worldness, increased hierarchy, lower clustering, improved efficiency and greater robustness. Notably, most of these parameters correlate with patients' cognitive performance.To test if a brain-wide coupling deficit could be at the origin of such network reorganization, we use a model of resting-state activity where the coupling strength can be manipulated. For a range of coupling values, the simulated functional graphs obtained were characterized using graph theory.For a coupling range, simulated graphs shared properties of healthy resting-state functional graphs. On decreasing the coupling strength, the resultant functional graphs exhibited a topological reorganization, in the same way as described in schizophrenia.This work shows how complex functional graph alterations reported in schizophrenia can be accounted for by a decrease in the structural coupling strength. These results are corroborated by reports of lower white matter density in schizophrenia.

[Pediatric inflammatory bowel disease: is it still increasing?]

INTRODUCTION

Crohn's disease (CD), Ulcerative Colitis (UC) and Indeterminate Colitis (IC), commonly known as Inflammatory Bowel Disease (IBD) represent a heterogeneous group of chronic diseases of unknown origin and varying course, diagnosed in pediatric age at 25 to 30% of cases. Epidemiological international studies studies show IBD incidence has increased exponentially in industrialized nations over the last 50 years.

OBJECTIVES

Characterization of the pediatric population diagnosed with IBD, followed at medical consultation in Gastroenterology at Hospital de Dona Estefânia (HDE).

MATERIAL AND METHODS

Descriptive and retrospective study by consulting the medical files of patients diagnosed with IBD followed between 1987 and 2009 (23 years). Clinical, radiological and histological criteria were used to define IBD. The following variables were studied: sex, family history, race, characterization of IBD, age at diagnosis, time from onset of symptoms to diagnosis and clinical presentation. Four different periods of time were compared: 1987-1992, 1993-1998, 1999-2004 and 2005-2009.

RESULTS

100 children were included (51 female), of which 59% are CD, 38% UC and 3% IC. Family history of IBD was present in 7 cases, with no sex difference between UC and CD. During the period of time between 2005-2009, it was registered the highest number of new cases (55 total, mean: 11 cases / year) and between 1987-1992 the lowest (9, 1.5 cases / year). Time from onset of symptoms to diagnosis was highly variable, ranging from 9 months (1987-1992) to 4 months (2005-2009). Children's age at the time of diagnosis varied from 14 months to 17 years, with a mean of 10.5 years. The most common symptoms at time of presentation were abdominal pain, diarrhea, and hematochezia.

CONCLUSION

IBD are a heterogeneous group of diseases, not always easy to diagnose and difficult to classify as diagnostic criteria are not always uniform. The results show the number of IBD new cases has been rising during the last two decades, mainly CD, with no difference between gender. Time from onset of symptoms to diagnosis has been decreasing although age at time of diagnosis and clinical presentation has showed no difference in the last 20 years.

Prevalence and incidence of Helicobacter pylori Infection in a healthy pediatric population in the Lisbon area

BACKGROUND

Helicobacter pylori is mainly acquired in childhood. Although adult studies reported a high prevalence of H. pylori infection in Portugal, the actual rate in children remains unknown. This study aimed to determine the prevalence and the incidence of H. pylori infection in an asymptomatic pediatric population of the Lisbon area and to correlate prevalence with sociodemographic determinants.

MATERIALS AND METHODS

Helicobacter pylori infection was determined by stool antigen test in 844 asymptomatic children (age 0-15 years; 49.4% boys). For the incidence study, H. pylori-negative children in the prevalence study were followed-up every 6 months over a 3-year period.

RESULTS

The global prevalence of H. pylori infection was 31.6%, increasing with age (19.9, 37.0 and 51.5%, in age groups 0-5, 6-10, and 11-15, respectively), but was similar among genders (34.5% in boys and 28.4% in girls). Older age and attendance of nursery/kindergarten during preschool constituted independent risk factors. The overall estimated incidence was 11.6 per 100 child-years (CY). Although 47.5% of children acquired H. pylori infection before 5 years of age, the mean age of acquisition was 6.3. The incidence of infection was similar among the three age groups (11.5, 13.0, and 10.5 per 100 CY, in age groups 0-5, 6-10, and 11-15, respectively).

CONCLUSIONS

The prevalence of H. pylori infection in the Portuguese pediatric population is still high. Although this study confirmed that the highest acquisition rate occurs at young age, it showed that in high-prevalence populations, older children can also acquire H. pylori infection at a rate similar to that of young children.

Diabetes and other glucose metabolism abnormalities in Mexican Zapotec and Mixe Indians

AIMS

Aboriginal populations are experiencing an explosive rise in the prevalence of Type 2 diabetes. The purpose of this study was to estimate the prevalence of diabetes and other glucose metabolism abnormalities in Mexican Zapotec and Mixe Indians and to determine their association with known risk factors.

METHODS

A cross-sectional study was conducted in the southern Mexican state of Oaxaca. Two communities of Zapotec population and three of Mixe population were randomly chosen. Mexican Indians>or=35 years old were invited to participate; 394 Zapotec and 730 Mixe Indians participated. Diabetes and other glucose metabolism abnormalities were diagnosed using standard World Health Organization criteria after an oral glucose tolerance test. Prevalence and odds ratio (OR) were estimated with 95% confidence intervals (95% CI).

RESULTS

The crude prevalence of diabetes was 8.19% (95% CI 6.7-9.9%) and the age- and sex-adjusted prevalence was 8.27%, significantly higher among Zapotec (8.71%) than among Mixe Indians (6.90%). The prevalence of impaired glucose tolerance was 9.9% and 4.7% of the studied subjects had impaired fasting glucose. The main risk factors related to the occurrence of diabetes were a family history of diabetes (OR 4.1; 95% CI 1.9-8.8), obesity (OR 3.0; 95% CI 1.6-5.6), hypertension (OR 2.6; 95% CI 1.5-4.7) and a high-risk waist-hip ratio (4.6; 95% CI 1.2-17.7).

CONCLUSIONS

The prevalence of diabetes is high in this population, the highest so far reported in Mexican Indians. Mexico's health system faces a huge challenge to avert the advanced spread of diabetes in this susceptible population.

[Hereditary pancreatitis in a child]

Hereditary pancreatitis is defined as a family history of two or more relatives with pancreatitis and clinical, biochemical, or radiologic evidence of pancreatitis. This is the fourth family described with hereditary pancreatitis related to mutation c.364C>T (p.R122C) of PRSS1 gene. The index case was a four year old child who had had his first episode of abdominal pain at age three. At that time he was admitted in hospital for two days and he improved with analgesic treatment only. One year later, in a second similar episode, he had been diagnosed with pancreatitis. His father was submitted to pancreato-duodenectomy (Whipple procedure) when he was 27 years old due to recurrent pancreatitis since age 19. Paternal grandfather and the parents of this grandfather had been diagnosed with diabetes mellitus. The mutation R122C was present in heterozigoty, in the exon 3 of PRSS1 gene, in the index case and also in his father. The importance of a long term follow-up is highlighted, taking into consideration the risk of ductal pancreatic adenocarcinoma.

[Paediatric Burkitt lymphoma presenting as acute pancreatitis]

Pancreatitis in children and adolescents is uncommon and its causes are more varied in this age group than in adults. A tumoral aetiology is particularly rare. We present the case of a 13-year-old boy who was admitted to our Intensive Care Unit with the diagnosis of acute pancreatitis, bilateral pleural effusion and ascites. Serial sonographic and computed tomography evaluations were suggestive of an infiltrative process of the gastric wall. Endoscopy showed an infiltrative tumor of the gastric mucosa and duodenum with a giant ulcer. Biopsies were compatible with Burkitt Lymphoma confirmed by ascitic fluid cytology and cytometry. Because of severe progressive cholestasis a temporary biliary stent was placed in the common bile duct. After staging (stage III), the patient was treated according to FAB LMB 96 chemotherapy protocol, achieving complete remission. Acute pancreatitis and cholestasis are rare presentations of lymphoma in the paediatric age group.

Limitations in knowledge of HIV transmission among HIV-positive patients accessing case management services in a resource-poor setting

HIV has increasingly become an infection of poverty. Adequate HIV transmission knowledge among HIV-positive patients is necessary to reduce the risk of secondary infection and protect those who are uninfected from transmission. This study was conducted among individuals enrolled in a program that serves impoverished HIV patients in the Boston area. Although the mean HIV transmission knowledge score was 80% for this group, a significant proportion of patients demonstrated limitations in knowledge of HIV transmission. Highly vulnerable patients, such as those who reported not accessing HIV medications, a history of sexual abuse, or problems getting clothing, had lower levels of HIV knowledge. This paper hopes to alert providers that their most vulnerable patients may be at an increased risk of re-infection or transmission due to limited HIV knowledge. Programs that serve HIV-positive patients coping with poverty and other serious problems need to ensure adequate knowledge of HIV transmission to reduce the overall burden of HIV in resource-poor settings.

Evaluation of rapid test Assure Helicobacter pylori for diagnosis of H. pylori in pediatric population

Non-invasive tests are needed to assess Helicobacter pylori infection, especially to screen a pediatric population. Assure H. pylori Rapid Test (Genelabs Diagnostics, Singapore) is an immunochromatographic assay device intended for the rapid detection of antibodies to H. pylori in human serum, plasma or whole blood. The aim of this study was to evaluate the performance of the rapid test, Assure H. pylori, in the diagnosis of H. pylori infection in children, using a Portuguese pediatric population. The study group included 130 children with age ranging from 1 to 14 years old (average age 9.2+/-3.1 years). According to the gold standard, 70 of the 130 patients studied were H. pylori positive and 60 were H. pylori negative. Using Assure H. pylori Rapid Test (Genelabs Diagnostics, Singapore), 53 sera had a positive result after 15 min (resulting in 17 false negatives) and 57 sera a negative result (resulting in 3 false positives). The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the test were 75.7%, 95.0%, 94.6% and 77.0% respectively. When a longer read time of 45 min is considered, the rapid test revealed a good performance (sensitivity 98.6% and specificity 95%) in the evaluation of the H. pylori infection in a pediatric population. In conclusion, the test showed a good performance, suggesting its applicability as a screening method for the H. pylori infection.

Helicobacter pylori virulence genotypes in Portuguese children and adults with gastroduodenal pathology

The aim of this study was to evaluate the prevalence of virulence genotypes, namely cagA, vacA and babA2, of Helicobacter pylori strains isolated from Portuguese adults and children presenting gastroduodenal pathology. One hundred thirty-six strains were studied, 82 isolated from adult patients (50 with nonulcerative gastritis and 32 with active peptic ulcer) and 58 isolated from children (54 with nonulcerative gastritis and 4 with duodenal ulcer). Genotyping of cagA, vacA and babA2 was assessed by polymerase chain reaction. Overall, Helicobacter pylori strains carrying more virulent genotypes were much more prevalent in adults than in children, particularly the type I ( vacAs1- and cagA-positive) and the triple-positive ( vacAs1-, cagA- and babA2-positive) strains ( P<0.001). A subpopulation of adults and children with nonulcerative gastritis was also studied, and differences in the prevalence of virulent genotypes were observed, either for individual genotypes ( P=0.017 for cagA, P=0.010 for vacAs1) or in combinations, i.e. the type I genotype ( P=0.005) and the triple-positive strains ( P=0.031). There was no difference between the two populations in the distribution of babA2 and m1/m2 genotypes. Considering the cohort effect in the epidemiology of Helicobacter pylori infection, these results suggest that different strains might circulate during different periods of time, or that, after infection in childhood, individual strains will undergo changes during the course of infection.

Study on the scale-up of human IgG3 purification using protein A affinity chromatography

The purification of human IgG3 subclass out of IgG (Immunoglobulin-G) was studied using protein A-Sepharose affinity chromatography. The effect of operational parameters such as flow rate, ionic strength, pH and size of sample was investigated, and the process was scaled-up 10-fold. The use of 0.5 m NaCl in the loading buffer had a dramatic effect in the purity of IgG3 recovered in the flowthrough fraction (values in the order of 97% were consistently obtained). This was attributed to a more effective binding of IgG subclasses 1, 2 and 4 to protein A (well known classical mechanism based in Fc fragment) and in some extent to a decrease in the binding of subclass 3 to protein A by the alternative mechanism based in the Fab fragment. The increase in residence time also increased in a relevant way the purity of IgG3. This is attributed to an increased effectiveness of the mechanisms mentioned above. The recovery yields in the IgG3 rich fraction were in the range 21-32% and are possibly a consequence of binding to protein A by the alternative mechanism and also due to deactivation during processing.

Dermatitis herpetiformis: should direct immunofluorescence be the only diagnostic criterion?

We describe a 7-year-old boy with dermatitis herpetiformis (DH) diagnosed on clinical and histologic evidence, negative direct immunofluorescence (DIF) findings for junctional IgA deposits in uninvolved skin, positive IgA endomysial and gliadin antibodies, and jejunal biopsy revealing a gluten-sensitive enteropathy. Treatment with dapsone led to the disappearance of cutaneous lesions and pruritus within 48 hours. Demonstration of IgA immune deposits in the dermal papillae has been the only acceptable criterion for the diagnosis of dermatitis herpetiformis. However, considering several reports in the literature of DH with a negative DIF and our own case, we believe that in the absence of the characteristic DIF pattern, one needs the combination of clinical, histologic, and immunologic data to support the diagnosis of DH. We also discuss recent developments in the diagnosis of DH.

Evaluation of a Western blot test, Helico blot 2.1, in the diagnosis of Helicobacter pylori infection in a pediatric population

BACKGROUND

Noninvasive diagnostic tests are useful as screening tools for Helicobacter pylori infection in pediatric populations. The aim of this study was to evaluate performance of the immunoblot assay, Helico Blot 2.1, for the diagnosis of H. pylori infection in symptomatic children.

MATERIALS AND METHODS

Immunoblot assay was used for detection of IgG antibodies to specific H. pylori proteins and to a recombinant H. pylori antigen, CIM marker. The study was performed on sera collected from 134 symptomatic, untreated children (mean age, 9.1 +/- 3.2 years; range, 1-14 years). H. pylori infection status was determined by culture, histology and rapid urease test.

RESULTS

Immunoblot assay yielded a positive result in 71 of the 72 infected patients (sensitivity 98.6%) and in eight of the 62 noninfected ones (specificity 87.1%). The predictive values for a positive and a negative result were 89.9% and 98.2%, respectively. The performance of the CIM band alone, as a marker for H. pylori infection status, was also evaluated. This band was present on the blot of 71 infected patients and on four of the 62 H. pylori-negative patients. The sensitivity, specificity, PPV and NPV of the CIM antigen were 98.6%, 93.5%, 94.7% and 98.3%, respectively.

CONCLUSIONS

The immunoblot assay Helico Blot 2.1 is a suitable noninvasive test for the serodiagnosis of H. pylori infection in children. The good level of performance demonstrated by the novel recombinant antigen CIM suggests it may be a useful contribution to the qualitative and quantitative performance of the Helico Blot 2.1 in pediatric populations.