Comparison of Prediction Model for Cardiovascular Autonomic Dysfunction Using Artificial Neural Network and Logistic Regression Analysis

Background

This study aimed to develop the artificial neural network (ANN) and multivariable logistic regression (LR) analyses for prediction modeling of cardiovascular autonomic (CA) dysfunction in the general population, and compare the prediction models using the two approaches.

Methods and Materials

We analyzed a previous dataset based on a Chinese population sample consisting of 2,092 individuals aged 30–80 years. The prediction models were derived from an exploratory set using ANN and LR analysis, and were tested in the validation set. Performances of these prediction models were then compared.

Results

Univariate analysis indicated that 14 risk factors showed statistically significant association with the prevalence of CA dysfunction (P<0.05). The mean area under the receiver-operating curve was 0.758 (95% CI 0.724–0.793) for LR and 0.762 (95% CI 0.732–0.793) for ANN analysis, but noninferiority result was found (P<0.001). The similar results were found in comparisons of sensitivity, specificity, and predictive values in the prediction models between the LR and ANN analyses.

Conclusion

The prediction models for CA dysfunction were developed using ANN and LR. ANN and LR are two effective tools for developing prediction models based on our dataset.     

Factors associated with sexual violence against men who have sex with men and transgendered individuals in Karnataka, India

Objectives

There is a lack of information on sexual violence (SV) among men who have sex with men and transgendered individuals (MSM-T) in southern India. As SV has been associated with HIV vulnerability, this study examined health related behaviours and practices associated with SV among MSM-T.

Design

Data were from cross-sectional surveys from four districts in Karnataka, India.

Methods

Multivariable logistic regression models were constructed to examine factors related to SV. Multivariable negative binomial regression models examined the association between physician visits and SV.

Results

A total of 543 MSM-T were included in the study. Prevalence of SV was 18% in the past year. HIV prevalence among those reporting SV was 20%, compared to 12% among those not reporting SV (p = .104). In multivariable models, and among sex workers, those reporting SV were more likely to report anal sex with 5+ casual sex partners in the past week (AOR: 4.1; 95%CI: 1.2–14.3, p = .029). Increased physician visits among those reporting SV was reported only for those involved in sex work (ARR: 1.7; 95%CI: 1.1–2.7, p = .012).

Conclusions

These results demonstrate high levels of SV among MSM-T populations, highlighting the importance of integrating interventions to reduce violence as part of HIV prevention programs and health services.     

Simple Scoring System and Artificial Neural Network for Knee Osteoarthritis Risk Prediction: A Cross-Sectional Study

Background

Knee osteoarthritis (OA) is the most common joint disease of adults worldwide. Since the treatments for advanced radiographic knee OA are limited, clinicians face a significant challenge of identifying patients who are at high risk of OA in a timely and appropriate way. Therefore, we developed a simple self-assessment scoring system and an improved artificial neural network (ANN) model for knee OA.

Methods

The Fifth Korea National Health and Nutrition Examination Surveys (KNHANES V-1) data were used to develop a scoring system and ANN for radiographic knee OA. A logistic regression analysis was used to determine the predictors of the scoring system. The ANN was constructed using 1777 participants and validated internally on 888 participants in the KNHANES V-1. The predictors of the scoring system were selected as the inputs of the ANN. External validation was performed using 4731 participants in the Osteoarthritis Initiative (OAI). Area under the curve (AUC) of the receiver operating characteristic was calculated to compare the prediction models.

Results

The scoring system and ANN were built using the independent predictors including sex, age, body mass index, educational status, hypertension, moderate physical activity, and knee pain. In the internal validation, both scoring system and ANN predicted radiographic knee OA (AUC 0.73 versus 0.81, p<0.001) and symptomatic knee OA (AUC 0.88 versus 0.94, p<0.001) with good discriminative ability. In the external validation, both scoring system and ANN showed lower discriminative ability in predicting radiographic knee OA (AUC 0.62 versus 0.67, p<0.001) and symptomatic knee OA (AUC 0.70 versus 0.76, p<0.001).

Conclusions

The self-assessment scoring system may be useful for identifying the adults at high risk for knee OA. The performance of the scoring system is improved significantly by the ANN. We provided an ANN calculator to simply predict the knee OA risk.     

Noise reduction and image quality improvement of low dose and ultra low dose brain perfusion CT by HYPR-LR processing

Purpose

To evaluate image quality and signal characteristics of brain perfusion CT (BPCT) obtained by low-dose (LD) and ultra-low-dose (ULD) protocols with and without post-processing by highly constrained back-projection (HYPR)–local reconstruction (LR) technique.

Methods and Materials

Simultaneous BPCTs were acquired in 8 patients on a dual-source-CT by applying LD (80 kV,200 mAs,14×1.2 mm) on tube A and ULD (80 kV,30 mAs,14×1.2 mm) on tube B. Image data from both tubes was reconstructed with identical parameters and post-processed using the HYPR-LR. Correlation coefficients between mean and maximum (MAX) attenuation values within corresponding ROIs, area under attenuation curve (AUC), and signal to noise ratio (SNR) of brain parenchyma were assessed. Subjective image quality was assessed on a 5-point scale by two blinded observers (1:excellent, 5:non-diagnostic).

Results

Radiation dose of ULD was more than six times lower compared to LD. SNR was improved by HYPR: ULD vs. ULD+HYPR: 1.9±0.3 vs. 8.4±1.7, LD vs. LD+HYPR: 5.0±0.7 vs. 13.4±2.4 (both p<0.0001). There was a good correlation between the original datasets and the HYPR-LR post-processed datasets: r = 0.848 for ULD and ULD+HYPR and r = 0.933 for LD and LD+HYPR (p<0.0001 for both). The mean values of the HYPR-LR post-processed ULD dataset correlated better with the standard LD dataset (r = 0.672) than unprocessed ULD (r = 0.542), but both correlations were significant (p<0.0001). There was no significant difference in AUC or MAX. Image quality was rated excellent (1.3) in LD+HYPR and non-diagnostic (5.0) in ULD. LD and ULD+HYPR images had moderate image quality (3.3 and 2.7).

Conclusion

SNR and image quality of ULD-BPCT can be improved to a level similar to LD-BPCT when using HYPR-LR without distorting attenuation measurements. This can be used to substantially reduce radiation dose. Alternatively, LD images can be improved by HYPR-LR to higher diagnostic quality.     

The molecular subtype classification is a determinant of sentinel node positivity in early breast carcinoma

Introduction

Several authors have underscored a strong relation between the molecular subtypes and the axillary status of breast cancer patients. The aim of our work was to decipher the interaction between this classification and the probability of a positive sentinel node biopsy.

Materials and Methods

Our dataset consisted of a total number of 2654 early-stage breast cancer patients. Patients treated at first by conservative breast surgery plus sentinel node biopsies were selected. A multivariate logistic regression model was trained and validated. Interaction covariate between ER and HER2 markers was a forced input of this model. The performance of the multivariate model in the training and the two validation sets was analyzed in terms of discrimination and calibration. Probability of axillary metastasis was detailed for each molecular subtype.

Results

The interaction covariate between ER and HER2 status was a stronger predictor (p = 0.0031) of positive sentinel node biopsy than the ER status by itself (p = 0.016). A multivariate model to determine the probability of sentinel node positivity was defined with the following variables; tumour size, lympho-vascular invasion, molecular subtypes and age at diagnosis. This model showed similar results in terms of discrimination (AUC = 0.72/0.73/0.72) and calibration (HL p = 0.28/0.05/0.11) in the training and validation sets. The interaction between molecular subtypes, tumour size and sentinel nodes status was approximated.

Discussion

We showed that biologically-driven analyses are able to build new models with higher performance in terms of breast cancer axillary status prediction. The molecular subtype classification strongly interacts with the axillary and distant metastasis process.     

Sociodemographic and disease correlates of body image distress among patients with systemic sclerosis

Background

Body image concerns are infrequently studied in systemic sclerosis (SSc), even though significant visible disfigurement is common. The objective of this study was to identify sociodemographic and disease-related correlates of dissatisfaction with appearance and social discomfort among people with SSc.

Methods

SSc patients came from the 15-center Canadian Scleroderma Research Group Registry. Sociodemographic information was based on patient self-report. Disease characteristics were obtained via physician examinations. The Brief-SWAP was used to assess dissatisfaction with appearance and social discomfort. Structural equation models were conducted with MPlus to determine the relationship of dissatisfaction with appearance and social discomfort with age, sex, education, marital status, race/ethnicity, disease duration, skin involvement, telangiectasias, skin pigmentation changes, and hand contractures.

Results

A total of 489 SSc patients (432 female, 57 male) were included. Extent of skin involvement was significantly associated with both dissatisfaction with appearance and social discomfort (standardized regression coefficients = 0.02, p = 0.001; 0.02, p = 0.020, respectively), as was skin involvement in the face (0.18, p = 0.016; 0.23, p = 0.006, respectively). Greater social discomfort was robustly associated with younger age (−0.017, p<0.001) and upper-body telangiectasias (0.32, p = 0.021). Dissatisfaction with appearance was associated with hand contractures (0.07, p = 0.036).

Conclusion

This study found that dissatisfaction with appearance and social discomfort were associated with numerous disfiguring characteristics of SSc, in addition to age. These results underline that there are multiple factors contributing to body image distress in SSc, as well as the need to attend to both disease and social contexts in understanding the impact of disfigurement among patients.     

Renal Function Declines More in Tenofovir- than Abacavir-Based Antiretroviral Therapy in Low-Body Weight Treatment-Na?ve Patients with HIV Infection

Objective

To compare the rate of decline of renal function in tenofovir- and abacavir-based antiretroviral therapy (ART) in low-body weight treatment-naïve patients with HIV infection.

Design

We conducted a single-center retrospective cohort study of 503 Japanese patients who commenced on either tenofovir- or abacavir-based initial ART.

Methods

The incidence of renal dysfunction, defined as more than 25% fall in estimated glomerular filtration rate (eGFR) from the baseline, was determined in each group. The effect of tenofovir on renal dysfunction was estimated by univariate and multivariate Cox hazards models as the primary exposure. Changes in eGFR until 96 weeks were estimated in both groups with a repeated measures mixed model.

Results

The median body weight of the cohort was 64 kg. The estimated incidence of renal dysfunction in the tenofovir and the abacavir arm was 9.84 per 100 and 4.55 per 100 person-years, respectively. Tenofovir was significantly associated with renal dysfunction by univariate and multivariate analysis (HR = 1.747; 95% CI, 1.152–2.648; p = 0.009) (adjusted HR = 2.080; 95% CI, 1.339–3.232; p<0.001). In subgroup analysis of the patients stratified by intertertile baseline body weight, the effect of tenofovir on renal dysfunction was more evident in patients with lower baseline body weight by multivariate analysis (≤60 kg: adjusted HR = 2.771; 95%CI, 1.494–5.139; p = 0.001) (61–68 kg: adjusted HR = 1.908; 95%CI, 0.764–4.768; p = 0.167) (>68 kg: adjusted HR = 0.997; 95%CI, 0.318–3.121; p = 0.995). The fall in eGFR was significantly greater in the tenofovir arm than the abacavir arm after starting ART (p = 0.003).

Conclusion

The incidence of renal dysfunction in low body weight patients treated with tenofovir was twice as high as those treated with abacavir. Close monitoring of renal function is recommended for patients with small body weight especially those with baseline body weight <60 kg treated with tenofovir.     

Effects of DPP-4 inhibitors on the heart in a rat model of uremic cardiomyopathy

Background

Uremic cardiomyopathy contributes substantially to mortality in chronic kidney disease (CKD) patients. Glucagon-like peptide-1 (GLP-1) may improve cardiac function, but is mainly degraded by dipeptidyl peptidase-4 (DPP-4).

Methodology/Principal Findings

In a rat model of chronic renal failure, 5/6-nephrectomized [5/6N] rats were treated orally with DPP-4 inhibitors (linagliptin, sitagliptin, alogliptin) or placebo once daily for 4 days from 8 weeks after surgery, to identify the most appropriate treatment for cardiac dysfunction associated with CKD. Linagliptin showed no significant change in blood level AUC(0-∞) in 5/6N rats, but sitagliptin and alogliptin had significantly higher AUC(0-∞) values; 41% and 28% (p = 0.0001 and p = 0.0324), respectively. No correlation of markers of renal tubular and glomerular function with AUC was observed for linagliptin, which required no dose adjustment in uremic rats. Linagliptin 7 µmol/kg caused a 2-fold increase in GLP-1 (AUC 201.0 ng/l*h) in 5/6N rats compared with sham-treated rats (AUC 108.6 ng/l*h) (p = 0.01). The mRNA levels of heart tissue fibrosis markers were all significantly increased in 5/6N vs control rats and reduced/normalized by linagliptin.

Conclusions/Significance

DPP-4 inhibition increases plasma GLP-1 levels, particularly in uremia, and reduces expression of cardiac mRNA levels of matrix proteins and B-type natriuretic peptides (BNP). Linagliptin may offer a unique approach for treating uremic cardiomyopathy in CKD patients, with no need for dose-adjustment.     

Postoperative Chemoradiotherapy versus Postoperative Chemotherapy for Completely Resected Gastric Cancer with D2 Lymphadenectomy: A Meta-Analysis

Background

Both chemoradiotherapy and chemotherapy are used in postoperative adjuvant therapy for resected gastric cancer. However, it is controversial whether chemoradiotherapy or chemotherapy is the optimal strategy for patients with gastric cancer after D2 lymphadenectomy. The present meta-analysis aims to provide more evidence on the relative benefits of adjuvant therapies in this setting.

Methods

We conducted a systematic review of randomized controlled trials, extracted time-to-event data using Tierney methods (when not reported), and performed meta-analysis to obtain the relative hazards of adjuvant chemoradiotherapy to chemotherapy on efficacy and toxicities.

Results

A total of 895 patients from 3 randomized controlled trials were identified for this meta-analysis. All patients were from Asian countries. Our results showed that postoperative chemoradiotherapy significantly improved locoregional recurrence-free survival [LRRFS: hazard ratio (HR) = 0.53, 95% CI = 0.32–0.87, p = 0.01] and disease-free survival (DFS: HR = 0.72, 95% CI = 0.59–0.89, p = 0.002); however, the improvement of distant metastasis recurrence-free survival (DMRFS: HR = 0.86; 95% CI = 0.66–1.11, p = 0.25) and overall survival (OS: HR = 0.79, 95% CI = 0.61–1.03, p = 0.08) were non-significant. The main grade 3 or 4 toxicities were equivalent between the two groups.

Conclusion

In non-selected Asian patients with resected gastric cancer who underwent D2 lymphadenectomy, postoperative chemoradiotherapy improved LRRFS and DFS but might not improve OS compared to postoperative chemotherapy.     

Comparison of artificial neural network and logistic regression models for predicting in-hospital mortality after primary liver cancer surgery

Background

Since most published articles comparing the performance of artificial neural network (ANN) models and logistic regression (LR) models for predicting hepatocellular carcinoma (HCC) outcomes used only a single dataset, the essential issue of internal validity (reproducibility) of the models has not been addressed. The study purposes to validate the use of ANN model for predicting in-hospital mortality in HCC surgery patients in Taiwan and to compare the predictive accuracy of ANN with that of LR model.

Methodology/Principal Findings

Patients who underwent a HCC surgery during the period from 1998 to 2009 were included in the study. This study retrospectively compared 1,000 pairs of LR and ANN models based on initial clinical data for 22,926 HCC surgery patients. For each pair of ANN and LR models, the area under the receiver operating characteristic (AUROC) curves, Hosmer-Lemeshow (H-L) statistics and accuracy rate were calculated and compared using paired T-tests. A global sensitivity analysis was also performed to assess the relative significance of input parameters in the system model and the relative importance of variables. Compared to the LR models, the ANN models had a better accuracy rate in 97.28% of cases, a better H-L statistic in 41.18% of cases, and a better AUROC curve in 84.67% of cases. Surgeon volume was the most influential (sensitive) parameter affecting in-hospital mortality followed by age and lengths of stay.

Conclusions/Significance

In comparison with the conventional LR model, the ANN model in the study was more accurate in predicting in-hospital mortality and had higher overall performance indices. Further studies of this model may consider the effect of a more detailed database that includes complications and clinical examination findings as well as more detailed outcome data.     

Quality of data entry using single entry, double entry and automated forms processing--an example based on a study of patient-reported outcomes

Background

The clinical and scientific usage of patient-reported outcome measures is increasing in the health services. Often paper forms are used. Manual double entry of data is defined as the definitive gold standard for transferring data to an electronic format, but the process is laborious. Automated forms processing may be an alternative, but further validation is warranted.

Methods

200 patients were randomly selected from a cohort of 5777 patients who had previously answered two different questionnaires. The questionnaires were scanned using an automated forms processing technique, as well as processed by single and double manual data entry, using the EpiData Entry data entry program. The main outcome measure was the proportion of correctly entered numbers at question, form and study level.

Results

Manual double-key data entry (error proportion per 1000 fields = 0.046 (95% CI: 0.001–0.258)) performed better than single-key data entry (error proportion per 1000 fields = 0.370 (95% CI: 0.160–0.729), (p = 0.020)). There was no statistical difference between Optical Mark Recognition (error proportion per 1000 fields = 0.046 (95% CI: 0.001–0.258)) and double-key data entry (p = 1.000). With the Intelligent Character Recognition method, there was no statistical difference compared to single-key data entry (error proportion per 1000 fields = 6.734 (95% CI: 0.817–24.113), (p = 0.656)), as well as double-key data entry (error proportion per 1000 fields = 3.367 (95% CI: 0.085–18.616)), (p = 0.319)).

Conclusions

Automated forms processing is a valid alternative to double manual data entry for highly structured forms containing only check boxes, numerical codes and no dates. Automated forms processing can be superior to single manual data entry through a data entry program, depending on the method chosen.     

Validating a Scoring System for the Diagnosis of Smear-Negative Pulmonary Tuberculosis in HIV-Infected Adults

Background

The challenge of diagnosing smear-negative pulmonary TB (tuberculosis) in people living with HIV justifies the use of instruments other than the smear test for diagnosing the disease. Considering the clinical-radiological similarities of TB amongst HIV-infected adults and children, the proposal of this study was to assess the accuracy of a scoring system used to diagnose smear-negative pulmonary TB in children and adolescents, in HIV-infected adults suspected of having smear-negative pulmonary TB.

Methods

A Phase III validation study aiming to assess the diagnostic accuracy of a scoring system for diagnosing smear-negative pulmonary TB in HIV-infected adults. The study assessed sensitivity, specificity, positive and negative likelihood ratios, and positive and negative predictive values of the scoring system. Three versions of the scoring system were tested.

Results

From a cohort of 2,382 (HIV-infected adults), 1276 were investigated and 128 were diagnosed with pulmonary TB. Variables associated with the diagnosis of TB were: coughing, weight loss, fever, malnutrition, chest X-ray, and positive tuberculin test. The best diagnostic performance occurred with the scoring system with new scores, with sensitivity = 81.2% (95%-CI 74.5% –88%), specificity = 78% (75.6% –80.4%), PPV = 29.2% (24.5% –33.9%) and NPV = 97.4% (96.4% –98.4%), LR+ = 3.7 (3.4–4.0) and LR− = 0.24 (0.2–0.4).

Conclusion

The proposed scoring system (with new scores) presented a good capacity for discriminating patients who did not have pulmonary TB, in the studied population. Further studies are necessary in order to validate it, thus permitting the assessment of its use in diagnosing smear-negative pulmonary TB in HIV-infected adults.     

Prognostic Nomograms for Predicting Survival and Distant Metastases in Locally Advanced Rectal Cancers

Aim

To develop prognostic nomograms for predicting outcomes in patients with locally advanced rectal cancers who do not receive preoperative treatment.

Materials and Methods

A total of 883 patients with stage II–III rectal cancers were retrospectively collected from a single institution. Survival analyses were performed to assess each variable for overall survival (OS), local recurrence (LR) and distant metastases (DM). Cox models were performed to develop a predictive model for each endpoint. The performance of model prediction was validated by cross validation and on an independent group of patients.

Results

The 5-year LR, DM and OS rates were 22.3%, 32.7% and 63.8%, respectively. Two prognostic nomograms were successfully developed to predict 5-year OS and DM-free survival rates, with c-index of 0.70 (95% CI = [0.66, 0.73]) and 0.68 (95% CI = [0.64, 0.72]) on the original dataset, and 0.76 (95% CI = [0.67, 0.86]) and 0.73 (95% CI = [0.63, 0.83]) on the validation dataset, respectively. Factors in our models included age, gender, carcinoembryonic antigen value, tumor location, T stage, N stage, metastatic lymph nodes ratio, adjuvant chemotherapy and chemoradiotherapy. Predicted by our nomogram, substantial variability in terms of 5-year OS and DM-free survival was observed within each TNM stage category.

Conclusions

The prognostic nomograms integrated demographic and clinicopathological factors to account for tumor and patient heterogeneity, and thereby provided a more individualized outcome prognostication. Our individualized prediction nomograms could help patients with preoperatively under-staged rectal cancer about their postoperative treatment strategies and follow-up protocols.     

Risk factors associated with increased mortality among HIV infected children initiating antiretroviral therapy (ART) in South Africa

Objective

To identify demographic and clinical risk factors associated with mortality after initiation of antiretroviral therapy (ART) in a cohort of human immunodeficiency (HIV) infected children in KwaZulu-Natal, South Africa.

Methods

We performed a retrospective cohort study of 537 children initiating antiretroviral therapy at McCord Hospital in KwaZulu-Natal, South Africa. Data were extracted from electronic medical records and risk factors associated with mortality were assessed using Cox regression analysis.

Results

Overall there were 47 deaths from the cohort of 537 children initiating ART with over 991 child-years of follow-up (median 22 months on ART), yielding a mortality rate of 4.7 deaths per 100 child years on ART. Univariate analysis indicated that mortality was significantly associated with lower weight-for-age Z-score (p<0.0001), chronic diarrhea (p = 0.0002), lower hemoglobin (p = 0.002), age <3 years (p = 0.003), and CD4% <10% (p = 0.005). The final multivariable Cox proportional hazards mortality model found age less than 3 years (p = 0.004), CD4 <10% (p = 0.01), chronic diarrhea (p = 0.03), weight-for-age Z-score (<0.0001) and female gender as a covariate varying with time (p = 0.03) all significantly associated with mortality.

Conclusion

In addition to recognized risk factors such as young age and advanced immunosuppression, we found female gender to be significantly associated with mortality in this pediatric ART cohort. Future studies are needed to determine whether intrinsic biologic differences or socio-cultural factors place female children with HIV at increased risk of death following initiation of ART.     

Retinal ganglion cell loss is accompanied by antibody depositions and increased levels of microglia after immunization with retinal antigens

Background

Antibodies against retinal and optic nerve antigens are detectable in glaucoma patients. Recent studies using a model of experimental autoimmune glaucoma demonstrated that immunization with certain ocular antigens causes an immun-mediated retinal ganglion cell loss in rats.

Methodology/Principal Findings

Rats immunized with a retinal ganglion cell layer homogenate (RGA) had a reduced retinal ganglion cell density on retinal flatmounts (p = 0.007) and a lower number of Brn3⁺retinal ganglion cells (p = 0.0001) after six weeks. The autoreactive antibody development against retina and optic nerve was examined throughout the study. The levels of autoreactive antibodies continuously increased up to 6 weeks (retina: p = 0.004; optic nerve: p = 0.000003). Additionally, antibody deposits were detected in the retina (p = 0.02). After 6 weeks a reactive gliosis (GFAP density: RGA: 174.7±41.9; CO: 137.6±36.8, p = 0.0006; %GFAP⁺ area: RGA: 8.5±3.4; CO: 5.9±3.6, p = 0.006) as well as elevated level of Iba1⁺ microglia cells (p = 0.003) was observed in retinas of RGA animals.

Conclusions/Significance

Our findings suggest that these antibodies play a substantial role in mechanisms leading to retinal ganglion cell death. This seems to lead to glia cell activation as well as the invasion of microglia, which might be associated with debris clearance.     

When Tuberculosis Comes Back: Who Develops Recurrent Tuberculosis in California?

Background

Recurrent tuberculosis suggests potentially modifiable gaps in tuberculosis treatment and control activities. The frequency of late recurrences following treatment completion has not been well-studied. We determined the frequency of, and risk factors associated with, tuberculosis that recurs at least one year after completion of anti-tuberculosis therapy in California.

Methods

The study population included culture-positive, pulmonary tuberculosis patients reported to the California tuberculosis case registry from 1993 to 2007 who completed anti-tuberculosis therapy. A person with late recurrent tuberculosis was defined as an individual that appeared in the registry more than once, determined by match on name and date-of-birth, with at least one year between treatment completion of the first episode and treatment initiation of the second episode.

Results

Among 23,517 tuberculosis patients, 148 (0.63%) had a late recurrence. Independent risk factors for recurrence included: infection with a pyrazinamide mono-resistant isolate (adjusted hazard ratio, 2.93; p = 0.019); initiation of an isoniazid- and rifampin-only treatment regimen (adjusted hazard ratio, 2.55; p = 0.0412); sputum smear-positive disease (adjusted hazard ratio, 1.96; p = 0.0003); human immunodeficiency virus infection (adjusted hazard ratio, 1.81; p = 0.0149); and birth in the United States (adjusted hazard ratio, 1.88; p = 0.0002). Infection with an isoniazid mono-resistant isolate was protective (adjusted hazard ratio, 0.25; p = 0.0171).

Conclusions

The low frequency of late recurrent tuberculosis in California suggests that local TB control programs are largely successful at preventing this adverse outcome. Nonetheless, we identified subpopulations at increased risk of late tuberculosis recurrence that may benefit from additional medical or public health interventions.     

Detection of Microbial Translocation in HIV and SIV Infection Using the Limulus Amebocyte Lysate Assay is Masked by Serum and Plasma

Objective

Microbial translocation (MT) is thought to be a major contributor to the pathogenesis of HIV-related immune activation, and circulating lipopolysaccharide (LPS) from Gram-negative bacteria is the principle measurement of this process. However, related research has been impeded by inconsistent LPS test results.

Methods

Specimens were obtained from HIV-infected adults enrolled in the PEARLS study (ACTG A5175) and HIV-HCV co-infected participants enrolled in a study of liver disease staging using MRI elastography. Pig-tailed macaque specimens were obtained from SIV-infected and –uninfected animals. Samples were tested for LPS using the LAL assay with diazo-coupling modifications to improve sensitive detection.

Results

When exogenous LPS was added to macaque plasma, >25% inhibition of LPS detection was found in 10/10 (100%) samples at 20% plasma concentration compared to control; in contrast 5/10 (50%) samples at 2% plasma concentration (p = 0.07) and 0/10 (0%) at 0.1% plasma concentration (p = 0.004) showed >25% inhibition of LPS detection. Similarly, when LPS was added to human serum, >25% inhibition of LPS detection was found in 5/12 (42%) of samples at 2% serum concentration compared to control, while 0/12 (0%) of samples in 0.1% serum showed >25% inhibition of LPS detection (p = 0.07). Likewise, LPS detection in human sera without exogenous LPS was improved by dilution: LPS was detected in 2/12 (17%) human samples in 2% serum, ranging from 3,436–4,736 pg/mL, compared to 9/12 (75%) samples in 0.1% serum, ranging from 123 pg/mL –60,131 pg/mL (p = 0.016). In a separate validation cohort of HIV-HCV co-infected participants sampled at two different times on the same day, LPS measured in 0.2% plasma and with diazo-coupling was closely correlated between the first and second samples (R = 0.66, p<0.05).

Conclusions

Undiluted serum and plasma mask LPS detection. The extent of MT may be substantially underestimated.     

Impact of genetic variation in SORCS1 on memory retention

Objective

We previously reported that genetic variants in SORCS1 increase the risk of AD, that over-expression of SorCS1 reduces γ-secretase activity and Aβ levels, and that SorCS1 suppression increases γ-secretase processing of APP and Aβ levels. We now explored the effect of variation in SORCS1 on memory.

Methods

We explored associations between SORCS1-SNPs and memory retention in the NIA-LOAD case control dataset (162 cases,670 controls) and a cohort of Caribbean Hispanics (549 cases,544 controls) using single marker and haplotype analyses.

Results

Three SNPs in intron 1, were associated with memory retention in the NIA-LOAD dataset or the Caribbean Hispanic dataset (rs10884402(A allele:β = −0.15,p = 0.008), rs7078098(C allele:β = 0.18,p = 0.007) and rs950809(C allele:β = 0.17,p = 0.008)) and all three SNPs were significant in a meta-analysis of both datasets (0.002ConclusionsVariation in intron 1 in SORCS1 is associated with memory changes in AD.     

Safety and Tolerability of Lactobacillus reuteri DSM 17938 and Effects on Biomarkers in Healthy Adults: Results from a Randomized Masked Trial

Background

There are few carefully-designed studies investigating the safety of individual probiotics approved under Investigational New Drug policies.

Objectives

The primary aim of this prospective, double-blind placebo-controlled trial was to investigate if daily treatment of adults with Lactobacillus reuteri DSM 17938 (LR) for 2 months is safe and well-tolerated. Our secondary aim was to determine if LR treatment has immune effects as determined by regulatory T cell percentages, expression of toll-like receptors (TLR)-2 and −4 on circulating peripheral blood mononuclear cells (PMBCs), cytokine expression by stimulated PBMC, and intestinal inflammation as measured by fecal calprotectin.

Methods

Forty healthy adults were randomized to a daily dose of 5×10⁸ CFUs of LR (n = 30) or placebo (n = 10) for 2 months. Participants completed a daily diary card and had 7 clinic visits during treatment and observation.

Results

There were no severe adverse events (SAEs) and no significant differences in adverse events (AEs). There were no differences in PBMC subclasses, TLRs, or cytokine expression after treatment. The probiotic-treated group had a significantly higher fecal calprotectin level than the placebo group after 2 months of treatment: 50 µg/g (IQR 24–127 µg/g) vs. 17 µg/g (IQR 11–26 µg/g), p = 0.03, although values remained in the normal clinical range (0–162.9 µg/g). LR vials retained >10⁸ CFUs viable organisms/ml.

Conclusions

LR is safe and well tolerated in adults, without significant changes in immunologic markers. There was a small but significant increase in fecal calprotectin, perhaps indicating some element of immune recognition at the intestinal level.

Trial Registration

Clinical Trials.gov {"type":"clinical-trial","attrs":{"text":"NCT00922727","term_id":"NCT00922727"}}NCT00922727