Effect of pancreatic and/or renal transplantation on diabetic autonomic neuropathy

Thirty-nine Type 1 (insulin-dependent) diabetic patients were studied prospectively after simultaneous pancreas and kidney (n=26) and kidney grafting alone (n=13) by measuring heart rate variation during various manoeuvers and answering a standardized questionnaire every 6 to 12 months post-transplant. While age, duration of diabetes, and serum creatinine (168.1±35.4 vs 132.7±17.7 mgrmol/l) were comparable, haemoglobin A1 levels were significantly lower (6.6±0.2 vs 8.5±0.3%; p<0.01) and the mean observation time longer (35±2 vs 25±3 months; p<0.05) in the pancreas recipients when compared with kidney transplanted patients. Heart rate variation during deep breathing, lying/standing and Valsalva manoeuver were very similar in both groups initially and did not improve during follow-up. However, there was a significant reduction in heart rate in the pancreas recipient group. Autonomic symptoms of the gastrointestinal and thermoregulatory system improved more in the pancreas grafted subjects, while hypoglycaemia unawareness deteriorated in the kidney recipients. This study suggests that long-term normoglycaemia by successful pancreatic grafting is able to halt the progression of autonomic dysfunction

Standard Measures are Inadequate to Monitor Pediatric Adherence in a Resource-Limited Setting

This study aims to compare the use and cost of objective and subjective measures of adherence to pediatric antiretroviral treatment in a primary care facility in South Africa. In a 1-month longitudinal study of 53 caregiver-child dyads, pharmacy refill (PR), measurement of returned syrups (RS), caregiver self-report (3DR) and Visual Analogue Scale (VAS) were compared to Medication Event Monitoring System (MEMS). Adherence was 100% for both VAS and 3DR; by PR and RS 100% and 103%, respectively. MEMS showed that 92% of prescribed doses were administered, but only 66% of these within the correct 12-hourly interval. None of the four measures correlated significantly with MEMS. MEMS data suggest that timing of doses is often more deviant from prescribed than expected and should be better addressed when monitoring adherence. Of all, MEMS was by far the most expensive measure. Alternative, cheaper electronic devices need to be more accessible in resource-limited settings

Serial MR diffusion to predict treatment response in high-grade pediatric brain tumors: a comparison of regional and voxel-based diffusion change metrics

Background Assessment of treatment response by measuring tumor size is known to be a late and potentially confounded response index. Serial diffusion MRI has shown potential for allowing earlier and possibly more reliable response assessment in adult patients, with limited experience in clinical settings and in pediatric brain cancer. We present a retrospective study of clinical MRI data in children with high-grade brain tumors to assess and compare the values of several diffusion change metrics to predict treatment response. Methods Eighteen patients (age range, 1.9–20.6 years) with high-grade brain tumors and serial diffusion MRI (pre- and posttreatment interval range, 1–16 weeks posttreatment) were identified after obtaining parental consent. The following diffusion change metrics were compared with the clinical response status assessed at 6 months: (1) regional change in absolute and normalized apparent diffusivity coefficient (ADC), (2) voxel-based fractional volume of increased (fiADC) and decreased ADC (fdADC), and (3) a new metric based on the slope of the first principal component of functional diffusion maps (fDM). Results Responders (n = 12) differed significantly from nonresponders (n = 6) in all 3 diffusional change metrics demonstrating higher regional ADC increase, larger fiADC, and steeper slopes (P < .05). The slope method allowed the best response prediction (P < .01, η2 = 0.78) with a classification accuracy of 83% for a slope of 58° using receiver operating characteristic (ROC) analysis. Conclusions We demonstrate that diffusion change metrics are suitable response predictors for high-grade pediatric tumors, even in the presence of variable clinical diffusion imaging protocols

Risky sexual practices among youth attending a sexually transmitted infection clinic in Dar es Salaam, Tanzania

\ud Youth have been reported to be at a higher risk of acquiring STIs with significant adverse health and social consequences. Knowledge on the prevailing risky practices is an essential tool to guide preventive strategies. Youth aged between 18 and 25 years attending an STI clinic were recruited. Social, sexual and demographic characteristics were elicited using a structured standard questionnaire. Blood samples were tested for syphilis and HIV infections. Urethral, high vaginal and cervical swabs were screened for common STI agents. A total of 304 youth were studied with mean age of 21.5 and 20.3 years for males and females respectively. 63.5% of youth were seeking STI care. The mean age of coitache was 16.4 and 16.2 years for males and females respectively. The first sexual partner was significantly older in females compared to male youth (23.0 vs 16.8 years) (p < 0.01). 93.2% of male youth reported more than one sexual lifetime partner compared to 63.0% of the females. Only 50% of males compared to 43% of females had ever used a condom and fewer than 8.3% of female youth used other contraceptive methods. 27.1% of pregnancies were unplanned and 60% of abortions were induced. 42.0% of female youth had received gifts/money for sexual favours. The HIV prevalence was 15.3% and 7.5% for females and males respectively. The prevalence of other STIs was relatively low. Among male youth, use of alcohol or illicit drugs was associated with increased risk of HIV infection. However, the age of sexual initiation, number of sexual partners or the age of the first sexual partner were not associated with increased risk of being HIV infected. Most female youth seen at the STI clinic had their first sexual intercourse with older males. Youth were engaging in high risk unprotected sexual practices which were predisposing them to STIs and unplanned pregnancies. There is a great need to establish more youth-friendly reproductive health clinics, encourage consistent and correct use of condoms, delay in sexual debut and avoid older sexual partners in females.\u

Classification of paediatric brain tumours by diffusion weighted imaging and machine learning

To determine if apparent diffusion coefficients (ADC) can discriminate between posterior fossa brain tumours on a multicentre basis. A total of 124 paediatric patients with posterior fossa tumours (including 55 Medulloblastomas, 36 Pilocytic Astrocytomas and 26 Ependymomas) were scanned using diffusion weighted imaging across 12 different hospitals using a total of 18 different scanners. Apparent diffusion coefficient maps were produced and histogram data was extracted from tumour regions of interest. Total histograms and histogram metrics (mean, variance, skew, kurtosis and 10th, 20th and 50th quantiles) were used as data input for classifiers with accuracy determined by tenfold cross validation. Mean ADC values from the tumour regions of interest differed between tumour types, (ANOVA P < 0.001). A cut off value for mean ADC between Ependymomas and Medulloblastomas was found to be of 0.984 × 10-3 mm2 s-1 with sensitivity 80.8% and specificity 80.0%. Overall classification for the ADC histogram metrics were 85% using Naïve Bayes and 84% for Random Forest classifiers. The most commonly occurring posterior fossa paediatric brain tumours can be classified using Apparent Diffusion Coefficient histogram values to a high accuracy on a multicentre basis

Metrics and textural features of MRI diffusion to improve classification of pediatric posterior fossa tumors

BACKGROUND AND PURPOSE: Qualitative radiologic MR imaging review affords limited differentiation among types of pediatric posterior fossa brain tumors and cannot detect histologic or molecular subtypes, which could help to stratify treatment. This study aimed to improve current posterior fossa discrimination of histologic tumor type by using support vector machine classifiers on quantitative MR imaging features. MATERIALS AND METHODS: This retrospective study included preoperative MRI in 40 children with posterior fossa tumors (17 medulloblastomas, 16 pilocytic astrocytomas, and 7 ependymomas). Shape, histogram, and textural features were computed from contrast-enhanced T2WI and T1WI and diffusivity (ADC) maps. Combinations of features were used to train tumor-type-specific classifiers for medulloblastoma, pilocytic astrocytoma, and ependymoma types in separation and as a joint posterior fossa classifier. A tumor-subtype classifier was also produced for classic medulloblastoma. The performance of different classifiers was assessed and compared by using randomly selected subsets of training and test data. RESULTS: ADC histogram features (25th and 75th percentiles and skewness) yielded the best classification of tumor type (on average >95.8% of medulloblastomas, >96.9% of pilocytic astrocytomas, and >94.3% of ependymomas by using 8 training samples). The resulting joint posterior fossa classifier correctly assigned >91.4% of the posterior fossa tumors. For subtype classification, 89.4% of classic medulloblastomas were correctly classified on the basis of ADC texture features extracted from the Gray-Level Co-Occurence Matrix. CONCLUSIONS: Support vector machine–based classifiers using ADC histogram features yielded very good discrimination among pediatric posterior fossa tumor types, and ADC textural features show promise for further subtype discrimination. These findings suggest an added diagnostic value of quantitative feature analysis of diffusion MR imaging in pediatric neuro-oncology

SIOP Ependymoma I: Final results, long term follow-up and molecular analysis of the trial cohort: A BIOMECA Consortium Study

BACKGROUND: SIOP Ependymoma I was a non-randomised trial assessing event free and overall survival (EFS/OS) of non-metastatic intracranial ependymoma in children aged 3 to 21 years treated with a staged management strategy. A further aim was to assess the response rate (RR) of subtotally resected (STR) ependymoma to vincristine, etoposide and cyclophosphamide (VEC). We report final results with 12-year follow-up and post hoc analyses of recently described biomarkers. METHODS: 74 participants were eligible. Children with gross total resection (GTR) received radiotherapy, whilst those with STR received VEC before radiotherapy. DNA methylation, 1q, hTERT, ReLA, Tenascin-C, H3K27me3 and pAKT status were evaluated. RESULTS: Five- and ten-year EFS was 49.5% and 46.7%, OS was 69.3% and 60.5%. GTR was achieved in 33/74 (44.6%) and associated with improved EFS (p=0.003, HR=2.6, 95% confidence interval (CI) 1.4-5.1). Grade 3 tumours were associated with worse OS (p=0.005, HR=2.8, 95%CI 1.3-5.8). 1q gain and hTERT expression were associated with poorer EFS (p=0.003, HR=2.70, 95%CI 1.49-6.10 and p=0.014, HR=5.8, 95%CI 1.2-28) and H3K27me3 loss with worse OS (p=0.003, HR=4.6, 95%CI 1.5-13.2). Methylation profiles showed expected patterns. 12 participants with STR did not receive chemotherapy; a protocol violation. However, best chemotherapy RR was 65.5% (19/29, 95%CI 45.7-82.1), exceeding the prespecified 45%. CONCLUSIONS: Participants with totally resected ependymoma had the best outcomes. RR of STR to VEC exceeded the pre-specified efficacy criterion. However, cases of inaccurate stratification highlighted the need for rapid central review. 1q gain, H3K27me3 loss and hTERT expression were all associated with poorer survival outcomes

Treatment outcomes in HIV-infected adolescents attending a community-based antiretroviral therapy clinic in South Africa

<p>Abstract</p> <p>Background</p> <p>Very few data are available on treatment outcomes of adolescents living with HIV infection (whether perinatally acquired or sexually acquired) in sub-Saharan Africa. The present study therefore compared the treatment outcomes in adolescents with those of young adults at a public sector community-based ART programme in Cape Town, South Africa.</p> <p>Methods</p> <p>Treatment outcomes of adolescents (9-19 years) were compared with those of young adults (20-28 years), enrolled in a prospective cohort between September 2002 and June 2009. Kaplan-Meier estimates and Cox proportional hazard models were used to assess outcomes and determine associations with age, while adjusting for potential confounders. The treatment outcomes were mortality, loss to follow-up (LTFU), immunological response, virological suppression and virological failure.</p> <p>Results</p> <p>883 patients, including 65 adolescents (47 perinatally infected and 17 sexually infected) and 818 young adults, received ART. There was no difference in median baseline CD4 cell count between adolescents and young adults (133.5 vs 116 cells/μL; <it>p </it>= 0.31). Overall mortality rates in adolescents and young adults were 1.2 (0.3-4.8) and 3.1 (2.4-3.9) deaths per 100 person-years, respectively. Adolescents had lower rates of virological suppression (< 400 copies/mL) at 48 weeks (27.3% vs 63.1%; <it>p </it>< 0.001). Despite this, however, the median change in CD4 count from baseline at 48 weeks of ART was significantly greater for adolescents than young adults (373 vs 187 cells/μL; <it>p </it>= 0.0001). Treatment failure rates were 8.2 (4.6-14.4) and 5.0 (4.1-6.1) per 100 person-years in the two groups. In multivariate analyses, there was no significant difference in LTFU and mortality between age groups but increased risk in virological failure [AHR 2.06 (95% CI 1.11-3.81; <it>p </it>= 0.002)] in adolescents.</p> <p>Conclusions</p> <p>Despite lower virological suppression rates and higher rates of virological failure, immunological responses were nevertheless greater in adolescents than young adults whereas rates of mortality and LTFU were similar. Further studies to determine the reasons for poorer virological outcomes are needed.</p

Development of a pre-operative scoring system for predicting risk of post-operative paediatric cerebellar mutism syndrome

BACKGROUND: Despite previous identification of pre-operative clinical and radiological predictors of post-operative paediatric cerebellar mutism syndrome (CMS), a unifying pre-operative risk stratification model for use during surgical consent is currently lacking. The aim of the project is to develop a simple imaging-based pre-operative risk scoring scheme to stratify patients in terms of post-operative CMS risk. METHODS: Pre-operative radiological features were recorded for a retrospectively assembled cohort of 89 posterior fossa tumour patients from two major UK treatment centers (age 2-23yrs; gender 28 M, 61 F; diagnosis: 38 pilocytic astrocytoma, 32 medulloblastoma, 12 ependymoma, 1 high grade glioma, 1 pilomyxoid astrocytoma, 1 atypical teratoid rhabdoid tumour, 1 hemangioma, 1 neurilemmoma, 2 oligodendroglioma). Twenty-six (29%) developed post-operative CMS. Based upon results from univariate analysis and C4.5 decision tree, stepwise logistic regression was used to develop the optimal model and generate risk scores. RESULTS: Univariate analysis identified five significant risk factors and C4.5 decision tree analysis identified six predictors. Variables included in the final model are MRI primary location, bilateral middle cerebellar peduncle involvement (invasion and/or compression), dentate nucleus invasion and age at imaging >12.4 years. This model has an accuracy of 88.8% (79/89). Using risk score cut-off of 203 and 238, respectively, allowed discrimination into low (38/89, predicted CMS probability <3%), intermediate (17/89, predicted CMS probability 3-52%) and high-risk (34/89, predicted CMS probability ≥52%). CONCLUSIONS: A risk stratification model for post-operative paediatric CMS could flag patients at increased or reduced risk pre-operatively which may influence strategies for surgical treatment of cerebellar tumours. Following future testing and prospective validation, this risk scoring scheme will be proposed for use during the surgical consenting process