Clinical course of chronic hepatitis B (CHB) presented with normal ALT in Asian American patients

The clinical course for chronic hepatitis B (CHB) patients with normal ALT and with or without minimal histologic activity remains unclear. We assessed frequency, amplitude, disease activities, and associated factors of ALT and/or AST flares in this subpopulation. Forty-seven consecutive treatment naïve Asian patients with CHB were enrolled from two liver clinics between December 2003 and January 2013, who had normal baseline ALT by routine clinical biochemical testing performed 6 weeks before or after the liver biopsy. We defined a flare as elevation of ALT/AST above the upper limit of normal of ALT/AST. The mean follow-up was 37.6 (CI = 12, 88) months, and the mean age at entry into the study was 43.3 (CI = 19, 65); 22/47 (46.8%) were males; 15/45 (33.3%), HBeAg+; 68.1% had stage 0-1 fibrosis; 63.8% had grade 0-1 inflammation. During follow-up, 13/47 (27.7%) cases developed ALT flare at least once in a mean of 13.5 (CI = 2, 43) months after liver biopsy; ALT flare was not associated with baseline ALT level, fibrosis stage, inflammation grade, hepatitis B virus (HBV) DNA load, HBeAg status, HBV genotype, HBV precore and basal core promoter mutations. 11/13 (84/6%) of ALT flares resolved during follow-up. 13/13 (100%) of ALT flares met AASLD treatment criteria, but only 6/13 (46.2%) were on HBV treatment. Serum ALT and/or AST flares occur frequently in CHB carriers who initially presented with normal ALT during pretreatment period. Thus, regular follow-up is warranted despite status of ALT/AST. No clinical factors were found to be associated with ALT flares.

Scaled Quantum Mechanical scale factors for vibrational calculations using alternate polarized and augmented basis sets with the B3LYP density functional calculation model

The Scaled Quantum Mechanical (SQM) method of scaling calculated force constants to predict theoretically calculated vibrational frequencies is expanded to include a broad array of polarized and augmented basis sets based on the split valence 6-31G and 6-311G basis sets with the B3LYP density functional. Pulay's original choice of a single polarized 6-31G(d) basis coupled with a B3LYP functional remains the most computationally economical choice for scaled frequency calculations. But it can be improved upon with additional polarization functions and added diffuse functions for complex molecular systems. The new scale factors for the B3LYP density functional and the 6-31G, 6-31G(d), 6-31G(d,p), 6-31G+(d,p), 6-31G++(d,p), 6-311G, 6-311G(d), 6-311G(d,p), 6-311G+(d,p), 6-311G++(d,p), 6-311G(2d,p), 6-311G++(2d,p), 6-311G++(df,p) basis sets are shown. The double d polarized models did not perform as well and the source of the decreased accuracy was investigated. An alternate system of generating internal coordinates that uses the out-of plane wagging coordinate whenever it is possible; makes vibrational assignments via potential energy distributions more meaningful. Automated software to produce SQM scaled vibrational calculations from different molecular orbital packages is presented.

Radiofrequency ablation of the great saphenous vein, comparing one versus two treatment cycles for the proximal vein segment

Objective

To evaluate the results of radiofrequency ablation (RFA) of the great saphenous vein (GSV) using one versus two 20 s energy cycle treatment in the proximal 7 cm segment of the GSV.

Methods

All patients who underwent RFA of the GSV from 1 May 2013 to 30 September 2013 in eight of our vein centers were included. Duplex ultrasound scans (DUSs) were performed prior to treatment on all patients and 2–3 days, and 1 month after procedure. Demographic data, GSV diameters, and other relevant data were recorded. Clinical, Etiologic, Anatomic, Pathologic (CEAP) classification and Venous Clinical Severity Scores (VCSSs) were determined prior to ablation and one month later. Patients who developed endovenous heat induced thrombosis (EHIT) were followed till resolution.

Results

A total of 205 patients had one cycle treatment (group A) and 204 had two cycle treatment (group B). The two groups were comparable in their demography, CEAP classification, and VCSS scores. The rate of failure of ablation and incidence of EHIT were also not significantly different. The incidence of complications was low, <5% in both groups and all were minor.

Conclusion

Two cycle treatment of the proximal GSV for vein ablation does not improve the success rate of vein closure in the short term, compared to one cycle treatment. It also does not increase the risks of DVT, EHIT, major bleeding, and other complications. However, we do not know at what diameter two cycles may be superior to one cycle.

Precore and basal core promoter mutations in Asian American patients with hepatitis B e antigen-positive chronic hepatitis B

BACKGROUND

Prior studies have shown that precore mutations abolish and basal core promoter (BCP) mutations down-regulate hepatitis B e antigen (HBeAg) production. Thus, the presence of precore and BCP mutations in HBeAg-positive patients indicates an infection with a mixed viral population of wild-type and precore and/or BCP mutant hepatitis B virus (HBV). To date, there has been limited study of the prevalence and clinical significance of precore and BCP mutations in patients with HBeAg-positive chronic hepatitis B.

AIM

To determine the prevalence, predictors and clinical characteristics of mixed wild-type and precore/BCP HBV infection, through a cross-sectional study, in a US cohort of patients with chronic hepatitis B.

METHODS

We conducted a retrospective study of 828 chronic hepatitis B patients with HBV genotype and mutation panel testing seen at three US gastroenterology and liver clinics from June 2005 to September 2009.

RESULTS

A majority of our patients (92.3%) were either Vietnamese or Chinese American. In the HBeAg-positive cohort, 17% of patients had precore mutations only, 28% had BCP mutations only and 5% had both BCP and precore mutations. On multivariate analyses, HBV genotype C, increasing age, lower HBV DNA level and an ALT quotient >2 were independent predictors for the presence of precore and/or BCP mutations.

CONCLUSIONS

The current distinction and management recommendations for HBeAg-positive vs. HBeAg-negative patients with chronic hepatitis B should be reassessed. Additional biomarkers and treatment endpoints should be studied for their usefulness in predicting continued viral suppression after treatment discontinuation.

SU-E-T-254: Quantitative Evaluation of Three Mathematical Models for Radiation-Induced Secondary Cancer Risk for Lung in Stereotactic Body Radiotherapy

PURPOSE

Several mathematical models exist to predict secondary cancer risks from radiotherapy treatment. In this study, we aimed to compare three dosimetry-based models in the application of stereotactic body radiotherapy (SBRT) of early-stage non-small cell lung cancer (NSCLC) with three radiotherapy treatment modalities.

METHODS

Ten patients who received definitive SBRT for early-stage NSCLC were retrospectively selected. for each patient, a helical tomotherapy (HT) plan, a three-dimensional conformal radiotherapy (3D-CRT) plan, and a volumetric modulated arc therapy (VMAT) plan were generated to deliver 50 Gy to the planning target volume in five fractions. The excess absolute risk (EAR) for secondary lung cancer occurrence was calculated using three risk models: the linear-exponential model, the plateau model, and the linear model. The sensitivity of the EAR to the prescription dose was evaluated by varying the prescription dose in the range of 40 to 60 Gy.

RESULTS

Based on the linear-exponential model, the average EAR's (in occurrences per 10,000 patients per year) were 8.4+/-2.7, 8.3+/-2.1, and 8.4+/-1.9 for the HT plans, 3D-CRT plans, and VMAT plans respectively with 40 Gy prescription dose, and 9.4+/-2.5, 9.0+/-2.1, and 9.3+/-1.8 with 60 Gy. Based on the plateau model, the average EAR's were 10.7+/-3.9, 10.6+/-3.0, and 10.9+/-2.8 with 40 Gy, and 12.9+/-4.2, 12.6+/-3.4, 12.9+/-3.1 with 60 Gy. Based on the linear model, the average EAR's were 29.1+/-13.4, 29.4+/-11.4, and 30.0+/-11.1 with 40 Gy, and 43.8+/-20.1, 44.0+/-11.0, 45.1+/-16.6 with 60 Gy. The difference in EAR's were not statistically significant among the HT, 3D-CRT, and VMAT plans.

CONCLUSIONS

Three secondary cancer risk models, as well as three SBRT treatment modalities, were compared. There was no significant difference in secondary lung cancer risks among the three treatment modalities in this study.

Detection of atomic and molecular mega-electron-volt projectiles using an x-ray charged coupled device camera

We show that an x-ray charge coupled device (CCD) may be used as a particle detector for atomic and molecular mega-electron-volt (MeV) projectiles of around a few hundred keV per atomic mass unit. For atomic species, spectroscopic properties in kinetic energy measurements (i.e., linearity and energy resolution) are found to be close to those currently obtained with implanted or surface barrier silicon particle detectors. For molecular species, in order to increase the maximum kinetic energy detection limit, we propose to put a thin foil in front of the CCD. This foil breaks up the molecules into atoms and spreads the charges over many CCD pixels and therefore avoiding saturation effects. This opens new perspectives in high velocity molecular dissociation studies with accelerator facilities.