Pleural Fluid Cytokine Levels at Baseline and Over Time are Associated With Time to IPC Removal: An Exploratory Study.

BACKGROUND: The behavior of pleural fluid cytokine (PFCs) levels and their association with pleurodesis after indwelling pleural catheter (IPC) placement is unknown. OBJECTIVE: A prospective exploratory study was conducted to obtain preliminary data on PFC levels after IPC placement. METHODS: The PFC panel consisted of 4 cytokines [interleukin -8 (IL-8), vascular endothelial growth factor, total (but not activated) transforming growth factor betas, and basic fibroblast growth factor], measured across 5 time points (T0: insertion; T1: 24 to 48 h; T2: 72 to 96 h; T3: 1 wk; and T4: 2 wk). Profile plots were used to identify patterns of change of PFC levels. Correlation matrices for each PFC over time were computed, and area under the curve (AUC) categories were used to compare the cumulative incidence of IPC removal. Auto pleurodesis was defined as elective catheter removal because of decreased drainage within 90 days of insertion. RESULTS: A total of 22 patients provided complete data. Except for IL-8, the majority of PFCs demonstrated strong positive correlations across measurement time points. Patients with high AUCs for IL-8, basic fibroblast growth factor, and vascular endothelial growth factor had a higher cumulative incidence of IPC removal by 90 days than did patients with low AUCs. CONCLUSION: This is the first study to evaluate longitudinal changes of pleural cytokine levels with respect to the likelihood of IPC removal and provide early evidence that the cytokine profile may be associated with the outcome of pleurodesis induced by IPCs. However, this is an exploratory study and further studies are needed to assess if these findings can be validated in further studies.

Predicting Lung Function Following Lobectomy: A New Method to Adjust for Inherent Selection Bias.

BACKGROUND: Predictions that overestimate post-lobectomy lung function are more likely than underestimates to lead to lobectomy. Studies of post-lobectomy lung function have included only surgical patients, so overestimates are overrepresented. This selection bias has led to incorrect estimates of prediction bias, which has led to inaccurate threshold values for determining lobectomy eligibility. OBJECTIVE: The objective of this study was to demonstrate and adjust for this selection bias in order to arrive at correct estimates of prediction bias, the 95% limits of agreement, and adjusted threshold values for determining when exercise testing is warranted. METHODS: We conducted a retrospective study of patients evaluated for lobectomy. We used multiple imputations to determine postoperative results for patients who did not have surgery because their predicted postoperative values were low. We combined these results with surgical patients to adjust for selection bias. We used the Bland-Altman method and the bivariate normal distribution to determine threshold values for surgical eligibility. RESULTS: Lobectomy evaluation was performed in 114 patients; 79 had lobectomy while 35 were ineligible based on predicted values. Prediction bias using the Bland-Altman method changed significantly after controlling for selection bias. To achieve a postoperative FEV1 > 30% and DLCO ≥30%, a predicted FEV1 > 46% and DLCO ≥53% were required. Compared to current guidelines, using these thresholds would change management in 17% of cases. CONCLUSION: The impact of selection bias on estimates of prediction accuracy was significant but can be corrected. Threshold values for determining surgical eligibility should be reassessed.

Viral associated diarrhea in immunocompromised and cancer patients at a large comprehensive cancer center: a 10-year retrospective study.

BACKGROUND: Viral associated diarrhea (VAD) due to Norovirus (NV), Rotavirus (RV) and Adenovirus (AV) is common in immunocompromised and cancer patients. We sought to determine if the clinical characteristics, morbidity and seasonality of infection differed according to the type of enteric virus identified. METHODS: Cases of NV, RV and AV were identified in stool specimens submitted to the clinical microbiology laboratory between November 2005 and February 2015. Clinical characteristics of patients, potential risk factors and outcomes were compared. RESULTS: A total of 97 VAD cases were identified: NV (n = 49), RV (n = 34) and AV (n = 14). The majority of cases were in patients with leukemia and lymphoma. NV (59%), RV (74%) and AV (78%) were identified in hematopoietic stem cell transplant (HSCT) recipients; and in patients with graft versus host disease (GVHD): NV (34%), RV (46%) and AV (57%). Nine cases of NV were genotyped; all were due to genotype II. Nine of 49 (18%) cases of NV, 7 of 34 (20%) cases of RV and 2 of 14 (14%) cases of AV were considered to be health care acquired (HCA). In multivariate analysis, immunosuppression (OR 2.8 95% CI 1.26-6.60, p = .01) and neutropenia (OR 4.8 95% CI 1.27-18.5, p = .01) were identified as risk factors for NV diarrhea compared to RV and AV. CONCLUSIONS: In our study, agents responsible for VAD occurred year round but predominated in the winter time; caused prolonged illness and were frequently health care associated. Presentations were atypical in many cases without upper gastrointestinal symptoms such as nausea and vomiting.

Transfer to intermediate forms following concept discrimination by pigeons: chimeras and morphs.

Two experiments examined pigeons' generalization to intermediate forms following training of concept discriminations. In Experiment 1, the training stimuli were sets of images of dogs and cats, and the transfer stimuli were head/body chimeras, which humans tend to categorize more readily in terms of the head part rather than the body part. In Experiment 2, the training stimuli were sets of images of heads of dogs and cats, and the intermediate stimuli were computer-generated morphs. In both experiments, pigeons learned the concept discrimination quickly and generalized with some decrement to novel instances of the categories. In both experiments, transfer tests were carried out with intermediate forms generated from both familiar and novel exemplars of the training sets. In Experiment 1, the pigeons' transfer performance, unlike that of human infants exposed to similar stimuli, was best predicted by the body part of the stimulus when the chimeras were formed from familiar exemplars. Spatial frequency analysis of the stimuli showed that the body parts were richer in high spatial frequencies than the head parts, so these data are consistent with the hypothesis that categorization is more dependent on local stimulus features in pigeons than in humans. There was no corresponding trend when the chimeras were formed from novel exemplars. In Experiment 2, when morphs of training stimuli were used, response rates declined smoothly as the proportion of the morph contributed by the positive stimulus fell, although results with morphs of novel stimuli were again less orderly.