Polymers arewidely utilized as protective coatings to prevent metal surfaces from wear, corrosion, or bio-fouling.Yet, stability and adhesive properties of polymer to metal bondings are not fully understood at themolecular level. Here,wemeasured the interaction forces between a gold electrode surface and amine-functionalized polymers (PEG) using a novel electrochemical surface forces apparatus. We examined the potential dependence of specific amine.gold interactions and measured that the binding strength of amine.gold bonds can range from 0.5 to 40 kBT per binding site, depending on the applied electrochemical potential. Notably, this interaction exhibits a pronounced minimum around the potential of zero charge, where the polymer.gold adhesion is dominated by non-specific interactions between the polymer backbone and electrode surface, consistent with the adhesion of PEG polymers with gold surfaces in the absence of amine functionalization. Further, repulsive hydration interactions were observed to be stronger for amine-terminated PEG compared to non-functionalized PEG, due to increased hydration and presence of counterions in the case of amine-terminated PEG. Our results provide molecular-scale insight into design and optimization of polymer coatings for numerous applications requiring strong, specific binding interactions between polymers and metals (or their native oxides), for example passivating layers in biomedical implants and electronic devices. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Purpose/objective(s)

Radiographic MRI response following prostate radiotherapy, particularly stereotactic body radiotherapy (SBRT), remains poorly understood. Our objective was to describe radiographic changes to the prostate gland and prostate tumor following SBRT of men treated on a prospective, randomized trial.

Materials/methods

MIRAGE (NCT04384770) is a single center, randomized phase III trial of patients receiving either CT or MRI guided SBRT for localized prostate cancer. Patients underwent pre-treatment and annual post-treatment MRIs, in addition to routine PSA surveillance. Outcomes reported include percent gland shrinkage, percent PSA response at one year, and presence of residual tumor based on radiographic interpretation. Patient characteristics were compared via two-sample t-test or Fischer's exact test. Both univariate and multivariable logistical analysis were employed to identify potential clinical predictors of residual tumor on 1-year follow up MRI.

Results

This study cohort included 94 eligible patients with baseline characteristics in Table 1. Residual lesions were seen in 13 patients (14%), 5/27 (18.5%) treated without ADT and 8/67 (12%) with ADT. PSA ablation was deep, with a 79% median decrease without ADT and 98% median decrease with ADT. Patients receiving ADT showed more gland shrinkage (17% vs. 34% shrinkage, p = 0.0001), while radiographic non-responders and responders experienced similar gland shrinkage (median 21% vs 29% shrinkage, p > 0.05). No significant clinical predictors of residual tumor were identified on univariate and multivariate analysis. No patient had any clinical or biochemical evidence of failure.

Conclusion

A total of 14% of patients were found to have residual tumor detected on MRI one year after SBRT. These data highlight the protracted nature of radiographic tumor response to radiation therapy, even with ablative radiation techniques. The analysis is limited by the lack of biopsy data to quantify whether visualized residual tumor harbor active cancer.

Background

Hepatitis B virus (HBV) infection is common with major clinical consequences. In Asian Americans, the HBsAg carrier rate ranges from 2% to 16% which approximates the rates from their countries of origin. Similarly, HBV is the most important cause of cirrhosis, hepatocellular carcinoma (HCC) and liver related deaths in HBsAg positive Asians worldwide.

Aim

To generate recommendations for the management of Asian Americans infected with HBV.

Methods

These guidelines are based on relevant data derived from medical reports on HBV from Asian countries as well as from studies in the HBsAg positive Asian Americans. The guidelines herein differ from other recommendations in the treatment of both HBeAg positive and negative chronic hepatitis B (CHB), in the approach to HCC surveillance, and in the management of HBV in pregnant women.

Results

Asian American patients, HBeAg positive or negative, with HBV DNA levels >2000 IU/mL (>10⁴ copies/mL) and ALT values above normal are candidates for anti-viral therapy. HBeAg negative patients with HBV DNA >2000 IU/mL and normal ALT levels but who have either serum albumin <3.5 g/dL or platelet count <130 000 mm³ , basal core promoter (BCP) mutations, or who have first-degree relatives with HCC should be offered treatment. Patients with cirrhosis and detectable HBV DNA must receive life-long anti-viral therapy. Indications for treatment include pregnant women with high viraemia, coinfected patients, and those requiring immunosuppressive therapy. In HBsAg positive patients with risk factors, life-long surveillance for HCC with alpha-fetoprotein (AFP) testing and abdominal ultrasound examination at 6-month intervals is required. In CHB patients receiving HCC treatments, repeat imaging with contrast CT scan or MRI at 3-month intervals is strongly recommended. These guidelines have been assigned to a Class (reflecting benefit vs. risk) and a Level (assessing strength or certainty) of evidence.

Conclusions

Application of the recommendations made based on a review of the relevant literature and the opinion of a panel of Asian American physicians with expertise in HBV treatment will inform physicians and improve patient outcomes.