Protein therapy holds great promise for treating a variety of diseases. To act on intracellular targets, therapeutic proteins must cross the plasma membrane. This has previously been achieved by covalent attachment to a variety of cell-penetrating peptides (CPPs). However, there is limited information on the relative performance of CPPs in delivering proteins to cells, specifically the cytosol and other intracellular locations. Here we use green fluorescent protein (GFP) as a model cargo to compare delivery capacity of five CPP sequences (Penetratin, R8, TAT, Transportan, Xentry) and cyclic derivatives in different human cell lines (HeLa, HEK, 10T1/2, HepG2) representing different tissues. Confocal microscopy analysis indicates that most fusion proteins when incubated with cells at 10 µM localise to endosomes. Quantification of cellular uptake by flow cytometry reveals that uptake depends on both cell type (10T1/2 > HepG2 > HeLa > HEK), and CPP sequence (Transportan > R8 > Penetratin≈TAT > Xentry). CPP sequence cyclisation or addition of a HA-sequence increased cellular uptake, but fluorescence was still contained in vesicles with no evidence of endosomal escape. Our results provide a guide to select CPP for endosomal/lysosomal delivery and a basis for developing more efficient CPPs in the future.
Readmission rates after radical cystectomy are significant, approaching 27% within the first 90 days. Gender and age adjusted Charlson comorbidity index were independent predictors providing preoperative information identifying patients more likely to require readmission or possibly to benefit from a longer initial hospital stay.
Background
Despite the documented survival benefit conferred by neoadjuvant (NAC) and adjuvant chemotherapy (AC), there has been a slow adoption of guideline recommendations for the use of perioperative chemotherapy (POC) in patients with muscle-invasive bladder cancer (MIBC).
Objective
To evaluate temporal trends in POC utilization and identify factors influencing POC delivery in a representative cohort of patients with MIBC.
Design, setting, and participants
Retrospective cohort study identifying factors associated with receipt of POC and evaluating temporal changes in NAC and AC utilization. We included patients from the National Cancer Data Base (NCDB) with no prior malignancy who ultimately underwent radical cystectomy for ≥cT2/cN0/cM0 MIBC between 2006 and 2010.
Outcome measurements and statistical analysis
Relationships between demographic and hospital factors and the likelihood of receiving POC were evaluated using Pearson chi-square and Wilcoxon rank-sum tests, and multivariable logistic regression. Temporal changes in NAC and AC use were detected using a linear test of trend.
Results and limitations
A total of 5692 patients met our inclusion criteria. POC use increased from 29.5% in 2006 to 39.8% in 2010 (p < 0.001). NAC use increased from 10.1% in 2006 to 20.8% in 2010 (p = 0.005); AC remained stable between 18.1% and 21.3% (p = 0.68). Multivariable modeling revealed advanced age, increasing comorbidity, lack of insurance, increased travel distance, geographic location outside the northeastern United States, and lower income as negatively associated with POC receipt (all p < 0.05). Limitations include retrospective design and potential sampling bias, excluding patients treated at non-NCDB facilities.
Conclusions
POC use for MIBC increased from 2006 to 2010, with this increase disproportionately due to rising NAC utilization. Nonetheless, there is persistent variation in the likelihood of receiving POC secondary to nonclinical factors.
Patient summary
When retrospectively analyzing a representative cohort of patients undergoing radical cystectomy for muscle-invasive bladder cancer between 2006 and 2010, we noted that preoperative chemotherapy rates increased steadily while use of chemotherapy after surgery remained stable. Factors related to access to care significantly influenced receipt of chemotherapy.
Objectives: To evaluate the accuracy of routinely available non-invasive tests (spiral computed tomographic angiography (CTA), time of flight magnetic resonance angiography (MRA), and colour Doppler ultrasound (DUS)), individually and together, compared with intra-arterial digital subtraction angiography (DSA) in patients with symptomatic tight carotid stenosis; and to assess the effect of substituting non-invasive tests for DSA on outcome, interobserver variability, and patient preference. Methods: Patients referred from a neurovascular clinic were subjected prospectively to DUS imaging. The operator was blind to symptoms. Patients with a tight carotid stenosis on the symptomatic side were admitted for DSA. CTA and MRA were performed during the admission. The CTA, MRA, and DSA films were each read independently by two of six experienced radiologists, blind to all other data. Results: 67 patients were included (34 had all four imaging procedures). DUS, CTA, and MRA all agreed with DSA in the diagnosis of operable v non-operable disease in about 80% of patients. CTA tended to underestimate (sensitivity 0.65, specificity 1.0), MRA to overestimate (sensitivity 1.0, specificity 0.57), and DUS to agree most closely with (sensitivity 0.85, specificity 0.71) the degree of stenosis as shown by DSA. When using any two of the three non-invasive tests in combination, adding the third if the first two disagreed would result in very few misdiagnoses (about 6%). MRA had similar interobserver variability to CTA (both worse than DSA). Patients preferred CTA over MRA and DSA. Conclusions: DUS, CTA, and MRA all show similar accuracy in the diagnosis of symptomatic carotid stenosis. No technique on its own is accurate enough to replace DSA. Two non-invasive techniques in combination, and adding a third if the first two disagree, appears more accurate, but may still result in diagnostic errors.
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