Feasibility of wearable activity trackers in cystectomy patients to monitor for postoperative complications.

BACKGROUND: To determine the feasibility of using wearables in patients undergoing radical cystectomy to monitor postoperative heart rate and activity and attempt to correlate these factors to complications and readmissions. MATERIALS AND METHODS: We conducted a prospective study of 20 patients undergoing radical cystectomy for bladder cancer between June 2017 and March 2018. Each patient was provided with a Garmin Vívofit heart rate (HR) activity tracker and instructed to wear it on their wrist for 30 days postoperatively. Heart rate, steps, and sleep data were collected during this time. Patients were called at 10-day intervals and surveyed for complications and device compliance. Univariable mixed effects logistic regression models were used to compare daily activity tracker measures with occurrence of an adverse event. Odds ratios, 95% confidence intervals, and p-values were reported. RESULTS: Median age was 65 (interquartile range 61-74) years. Patients had usable data for a median of 59.3% (interquartile range 25-71.7%) of the time. Five patients experienced a postoperative event (1 readmission for sepsis from urinary tract source, 1 inpatient rapid response called for tachycardic event, 3 unscheduled visits related to dehydration), where event data was recorded over a total of 17 days. Higher step count was associated with reduced odds of an adverse event (odds ratio 0.31, 95% confidence interval 0.10-0.98 per 1000 steps, p = 0.047). CONCLUSIONS: Postoperative activity and heart rate monitoring in cystectomy patients is feasible though current wearables are not well suited for this task.

18F-fluciclovine PET CT detection of biochemical recurrent prostate cancer at specific PSA thresholds after definitive treatment.

OBJECTIVES: To evaluate various Prostate-Specific Antigen (PSA) thresholds at which a 18F-fluciclovine PET scan could be considered in the setting of biochemical recurrent prostate cancer after definitive treatment. METHODS: We analyzed available records of men who underwent a 18F-fluciclovine PET scan after definitive therapy at a single academic institution between November 2016 to May 2018. The primary outcome was the rate of positive imaging findings at specific PSA thresholds. We then employed empiric strategies including a ROC curve and decision curve analysis to identify a specific threshold for which obtaining a positive result would be optimized. RESULTS: A total of 115 men underwent imaging with 18F-fluciclovine PET. No concerning lesions were identified in 25 (21.7%) patients, 32 (27.8%) had a solitary lesion identified, 45 (39.1%) had 2 to 5 lesions, and 13 (11.3%) had greater than 5 suspicious lesions identified. At PSA thresholds of less than 0.5, 0.5 to 2.0, and greater than 2, lesions were detected in 55.5% (12/22), 70.6% (24/34), and 91.5% (54/59) of patients respectively [P < 0.001]. Our ROC analysis yielded a PSA threshold of 2.10 while our decision curve analysis provided a PSA cutoff of 1.38. CONCLUSION: This study constitutes an early single institution series evaluating the use of 18F-fluciclovine PET scans in the assessment of biochemically recurrent prostate cancer after definitive treatment. The probability of having positive imaging findings and increasing numbers of suspicious lesions rises with increasing PSA. Utilization of a lower PSA threshold of 0.5 may allow earlier intervention with salvage therapies in biochemical recurrence. However, using a threshold below 1 carries a higher risk of negative scans. Employing a higher PSA threshold of 1 to 2 carries greater sensitivity and specificity and may maximize identifying individuals with early BCR who may benefit from early intervention, while minimizing negative scans.

A 96-well DNase I footprinting screen for drug-DNA interactions.

The established protocol for DNase I footprinting has been modified to allow multiple parallel reactions to be rapidly performed in 96-well microtitre plates. By scrutinizing every aspect of the traditional method and making appropriate modifications it has been possible to considerably reduce the time, risk of sample loss and complexity of footprinting, whilst dramatically increasing the yield of data (30-fold). A semi-automated analysis system has also been developed to present footprinting data as an estimate of the binding affinity of each tested compound to any base pair in the assessed DNA sequence, giving an intuitive 'one compound-one line' scheme. Here, we demonstrate the screening capabilities of the 96-well assay and the subsequent data analysis using a series of six pyrrolobenzodiazepine-polypyrrole compounds and human Topoisomerase II alpha promoter DNA. The dramatic increase in throughput, quantified data and decreased handling time allow, for the first time, DNase I footprinting to be used as a screening tool to assess DNA-binding agents.

Simulator sickness in a helicopter flight training school.

INTRODUCTION: Simulator sickness (SS) is a common problem during flight training and can affect both instructor pilots (IP) and student pilots (SP). This study was conducted in response to complaints about a high incidence of SS associated with use of new simulators for rotary-wing aircraft. METHODS: The problem was evaluated using the Simulator Sickness Questionnaire (SSQ) to collect data on 73 IP and 129 SP who used the new simulators. Based on analysis of these data, operator comments, and a search of the literature, we recommended limiting simulator flights to 2 h, removing unusual or unnatural maneuvers, turning off the sidescreens to reduce the field-of-view, avoiding use of improperly calibrated simulators until repaired, and stressing proper rest and health discipline among the pilots. The success of these measures was evaluated 1 yr later by collecting SSQ data on 25 IP and 50 SP. RESULTS: There was a main effect of time, in that after the recommendations were implemented, there was a significant reduction in nausea, oculomotor, and total SSQ scores from the pre-study to the post-study. There was also a main effect of experience, as IP reported significantly greater SS than SP for the same scores. DISCUSSION: Implementation of the recommendations reduced SS in the new simulators at the cost of limiting session duration and shutting down some simulator features. Although the optimal solution to the SS problem lies in addressing SS during a simulator's design stage, these recommendations can be used as interim solutions to reduce SS.

An asymmetric C8/C8'-tripyrrole-linked sequence-selective pyrrolo[2,1-c][1,4]benzodiazepine (PBD) dimer DNA interstrand cross-linking agent spanning 11 DNA base pairs.

A novel sequence-selective extended PBD dimer 4 has been synthesized that binds with high affinity to an interstrand cross-linking site spanning 11 DNA base pairs. Despite its molecular weight (984.07) and length, the molecule has significant DNA interstrand cross-linking potency (approximately 100-fold greater than the clinically used agent melphalan) and sub-micromolar cytotoxicity in a number of tumour cell lines, suggesting that it readily penetrates cellular and nuclear membranes to reach its DNA target.

Design, synthesis, and biophysical and biological evaluation of a series of pyrrolobenzodiazepine-poly(N-methylpyrrole) conjugates.

A novel series of methyl ester-terminated C8-linked pyrrolobenzodiazepine (PBD)-poly(N-methylpyrrole) conjugates (50a-f) has been synthesized and their DNA interaction evaluated by thermal denaturation, DNA footprinting, and in vitro transcription stop assays. The synergistic effect of attaching a PBD unit to a polypyrrole fragment is illustrated by the large increase in DNA binding affinity (up to 50-fold) compared to the individual PBD and pyrrole components. 50a-f were found to bind mainly to identical DNA sequences but with apparent binding site widths increasing with molecular length and the majority of sites conforming to the consensus motif 5'-XGXWz (z = 3 +/- 1; W = A or T; X = any base but preferably a purine). They also provided robust sequence-selective blockade of transcription at sites corresponding approximately to their DNA footprints. 50a-f were shown to have good cellular/nuclear penetration properties, and a degree of correlation between cytotoxicity and DNA-binding affinity was observed.

SG2285, a novel C2-aryl-substituted pyrrolobenzodiazepine dimer prodrug that cross-links DNA and exerts highly potent antitumor activity.

The pyrrolobenzodiazepines (PBD) are naturally occurring antitumor antibiotics, and a PBD dimer (SJG-136, SG2000) is in phase II trials. Many potent PBDs contain a C2-endo-exo unsaturated motif associated with the pyrrolo C-ring. The novel compound SG2202 is a PBD dimer containing this motif. SG2285 is a water-soluble prodrug of SG2202 in which two bisulfite groups inactivate the PBD N10-C11 imines. Once the bisulfites are eliminated, the imine moieties can bind covalently in the DNA minor groove, forming an interstrand cross-link. The mean in vitro cytotoxic potency of SG2285 against human tumor cell lines is GI(50) 20 pmol/L. SG2285 is highly efficient at producing DNA interstrand cross-links in cells, but they form more slowly than those produced by SG2202. Cellular sensitivity to SG2285 was primarily dependent on ERCC1 and homologous recombination repair. In primary B-cell chronic lymphocytic leukemia samples, the mean LD(50) was significantly lower than in normal age-matched B and T lymphocytes. Antitumor activity was shown in several human tumor xenograft models, including ovarian, non-small cell lung, prostate, pancreatic, and melanoma, with cures obtained in the latter model with a single dose. Further, in an advanced-stage colon model, SG2285 administered either as a single dose, or in two repeat dose schedules, was superior to irinotecan. Our findings define SG2285 as a highly active cytotoxic compound with antitumor properties desirable for further development.

Unusually strong positive cooperativity in binding of peptides to latent membrane protein-1 DNA fragments of the Epstein-Barr viral gene.

The DNA-binding preferences of two oligopeptide amides, (His-Pro-Arg-Lys)(3)NH(2) (HR-12) and (Ser-Pro-Arg-Lys)(3)NH(2) (SP-12), have been examined by quantitative DNase I footprinting studies. Two different DNA fragments were investigated: a pair of 5'-(32)P-labeled duplexes from pBR322 with one or other of the complementary strands labeled and a corresponding pair of 5'-(32)P-labeled duplexes representing fragments of the latent membrane protein (LMP-1) gene from a pathogenic Epstein-Barr virus variant derived from nasopharyngeal carcinoma. The major objective was to examine molecular recognition and cooperative features associated with sequence-selective binding of synthetic peptides to the LMP-1 fragments. At various binding sites on the pBR322 fragments, Hill coefficients (n(H)) ranging from 1.9-2.2 were observed; these results indicate modest positive cooperativity between binding sites for both peptides. By contrast, unusually high values of n(H), ranging from 4.0-9.3, were observed at various binding sites on the LMP-1 fragments. Allosteric models can be constructed to interpret the observed cooperative interactions between different DNA recognition sites in the LMP-1 gene upon binding of the peptide ligands. It is noteworthy that these models feature a novel network of cooperativity interconnecting multiple DNA allosteric sites. The evidence of sequence selectivity and strong cooperativity discovered in this work may prove to be a general feature of peptide interactions with some nucleic acids.

Preferential binding to DNA sequences of peptides related to a novel XPRK motif.

Two dodecapeptide amines: (WPRK)(3)NH(2)[WR-12] and (YPRK)(3)NH(2)[YR-12], and a 30-mer polypeptide amide (SP-30) were synthesized by solid-phase peptide methodology. DNase I footprinting studies on a 117-mer DNA showed that WR-12 and YR-12 bind selectively to DNA sequences in a manner similar to SP-30 which has a repeating SPK(R)K sequence. The most distinctive blockages seen with all three peptides occur at positions 26-30, 21-24 and 38-45 around sequences 5'-GAATT-3', 5'-TAAT-3' and 5'-AAAACGAC-3', respectively. However, it appears that YR-12 is better able to extend its recognition site to include CG pairs than is SP-30. At low concentrations YR-12 was able to induce enhanced rates of DNase I cleavage at regions surrounding some of its binding sites. To obtain further quantitative data supplementary to the footprinting work, equilibrium binding experiments were performed in which the binding of the two peptides to six decanucleotide duplexes was compared. Scatchard analyses indicated that WR-12 may be more selective for oligomers containing runs of consecutive purines or pyrimidines. On the other hand, YR-12 binds better to d(CTTAGACGTC)- d(GACGTCTAAG) than to the other oligomer duplexes, denoting selectivity for evenly distributed C/G and A/T sequences.