Long-Term Outcomes and Dynamics of Mutants Associated with Lamivudine-Adefovir Rescue Therapy in Patients with Lamivudine-Resistant Chronic Hepatitis B

Background/Aims

To investigate the association between the baseline profiles and dynamics of hepatitis B virus (HBV) DNA polymerase gene mutations and the long-term virological response of lamivudine (LAM)-adefovir (ADV) combination therapy in patients with LAM-resistant chronic hepatitis B.

Methods

Seventy-five patients who received LAM-ADV combination therapy for more than 12 months were analyzed. Restriction fragment mass polymorphism assays were used to detect and monitor the dynamics of LAM- and ADV-resistant mutations.

Results

The median duration of LAM-ADV combination therapy was 26 months (range, 12 to 58 months). The baseline mutation profiles, rtM204I (p=0.992), rtM204I/V (p=0.177), and rtL180M (p=0.051), were not correlated with the cumulative virological response, and the baseline HBV DNA level (p=0.032) was the only independent predictive factor for cumulative virological response. Tests for LAM- and ADV-resistant mutations were performed in 12 suboptimal responders in weeks 48 and 96. The population of rtM204 mutants persisted or increased in 8 of 12 patients, and rtA181T mutants newly emerged as a minor population in four patients until 96 weeks. Nevertheless, the viral loads progressively decreased during rescue therapy, and these dynamics did not correlate with virological response.

Conclusions

The baseline profile and dynamics of LAM-resistant mutations during LAM-ADV combination therapy are not associated with a virological response.     

Cytokine Expression of Microscopic Colitis Including Interleukin-17

Background/Aims

Microscopic colitis is characterized by chronic watery diarrhea with specific pathological changes that can be diagnosed by microscopic examination. We performed immunohistochemical analysis of proinflammatory cytokines to investigate the pathogenic mechanism of microscopic colitis.

Methods

This study consisted of six patients with lymphocytic colitis, six patients with collagenous colitis, and six patients with functional diarrhea but normal pathology. We performed an immunohistochemical analysis of the colonic mucosal biopsies to assess the expression of cyclo-oxygenase-2, interleukin-17, nuclear factor-κB, interferon-γ, inducible nitric oxide synthase, and tumor necrosis factor-α. We compared the quantity score of immunohistochemical staining among the groups.

Results

The microscopic colitis group showed significantly higher expression of cyclo-oxygenase-2, interleukin-17, nuclear factor-κB, and interferon-γ compared with the control group. Cytokine expression was similar between collagenous colitis and lymphocytic colitis. However, the expression of cyclo-oxygenase-2 was higher in collagenous colitis.

Conclusions

Proinflammatory cytokines, including interleukin-17 and interferon-γ, are highly expressed in microscopic colitis. The expression of cyclo-oxygenase-2 was higher in collagenous colitis than in lymphocytic colitis. This study is the first on interleukin-17 expression in microscopic colitis patients.     

The Effect of Niobium Doping on the Electrical Properties of 0.4(Bi0.5K0.5)TiO3-0.6BiFeO3 Lead-Free Piezoelectric Ceramics

Ceramics in the system (Bi_0.5K_0.5)TiO₃-BiFeO₃ have good electromechanical properties and temperature stability. However, the high conductivity inherent in BiFeO₃-based ceramics complicates measurement of the ferroelectric properties. In the present work, doping with niobium (Nb) is carried out to reduce the conductivity of (Bi_0.5K_0.5)TiO₃-BiFeO₃. Powders of composition 0.4(K_0.5Bi_0.5)Ti_1−xNb_xO₃-0.6BiFe_1−xNb_xO₃ (x = 0, 0.01 and 0.03) are prepared by the mixed oxide method and sintered at 1050 °C for 1 h. The effect of Nb doping on the structure is examined by X-ray diffraction. The microstructure is examined by scanning electron microscopy. The variation in relative permittivity with temperature is measured using an impedance analyzer. Ferroelectric properties are measured at room temperature using a Sawyer Tower circuit. Piezoelectric properties are measured using a d₃₃ meter and a contact type displacement sensor. All the samples have high density, a rhombohedral unit cell and equiaxed, micron-sized grains. All the samples show relaxor-like behavior. Nb doping causes a reduction in conductivity by one to two orders of magnitude at 200 °C. The samples have narrow P-E loops reminiscent of a linear dielectric. The samples all possess bipolar butterfly S-E loops characteristic of a classic ferroelectric material. Nb doping causes a decrease in d₃₃ and S_max/E_max.     

Effect of drug-loaded TiO<Subscript>2</Subscript> nanotube arrays on osseointegration in an orthodontic miniscrew: an <Emphasis Type="Italic">in-vivo</Emphasis> pilot study

Osseointegration was evaluated for the surface of miniscrews with TiO₂ nanotube arrays containing drugs in this in-vivo study. The diameter and length of the TiO₂ nanotube arrays were about 70 nm and 5 μm, respectively. Recombinant human bone morphogenetic protein-2 (rhBMP-2) or ibuprofen was loaded in the TiO₂ nanotube arrays with 12 miniscrews. The 12 drug-loaded miniscrews, 6 miniscrews with no drug-loaded TiO₂ nanotube arrays and 6 conventional miniscrews, were placed on the tibias of New Zealand white rabbits. Histological osseointegration was assessed 8 weeks after implantation by measuring the bone-to-implant contact (BIC) ratio. Ibuprofen-loaded miniscrews showed a significantly higher BIC of 71.6% over conventional miniscrews of 44.3% on average. The mean BIC ratios of rhBMP-2-loaded miniscrews and no drug-loaded miniscrews was 24.6% and 60.1%, respectively. Our results suggest that TiO₂ nanotube arrays on the surface of miniscrews could be used as carriers of drugs, and loading ibuprofen in TiO₂ nanotube arrays may improve osseointegration of miniscrews. However, the effect of rhBMP-2 loaded in TiO₂ nanotube arrays on osseointegration of miniscrews was questionable in this pilot study.     

Molecular and histological effects of MR-guided pulsed focused ultrasound to the rat heart

Background

Image-guided high intensity focused ultrasound has been used as an extracorporeal cardiac pacing tool and to enhance homing of stem cells to targeted tissues. However, molecular changes in the myocardium after sonication have not been widely investigated. Magnetic-resonance (MR)-guided pulsed focused ultrasound (pFUS) was targeted to the rat myocardium over a range of pressures and the microenvironmental and histological effects were evaluated over time.

Methods

Eight-to-ten-week-old Sprague–Dawley rats received T2-weighted MR images to target pFUS to the left ventricular and septum without cardiac or respiratory gating. Rats were sonicated through the thoracic wall at peak negative pressures (PNP) from 1 to 8 MPa at a center frequency of 1 MHz, 10 ms pulse duration and 1 Hz pulse repetition frequency for 100 pulses per focal target. Following pFUS, myocardium was harvested over 24 h and subjected to imaging, proteomic, and histological measurements.

Results

pFUS to the myocardium increased expression of cytokines, chemokines, and trophic factors characterized by an initial increase in tumor necrosis factor (TNF)-α followed by increases in pro- and anti-inflammatory factors that returned to baseline by 24 h. Immediately after pFUS, there was a transient (< 1 h) increase in N-terminal pro b-type natriuretic peptide (NT-proBNP) without elevation of other cardiac injury markers. A relationship between PNP and expression of TNF-α and NT-proBNP was observed with significant changes (p < 0.05 ANOVA) ≥ 4 MPa compared to untreated controls. Contrast-enhanced ex vivo T1-weighted MRI revealed vascular leakage in sonicated myocardium that was accompanied by the presence of albumin upon immunohistochemistry. Histology revealed infiltration of neutrophils and macrophages without morphological myofibril changes in sonicated tissue accompanied by pulmonary hemorrhage at PNP > 4 MPa.

Conclusions

MR-guided pFUS to myocardium induced transient proteomic and histological changes. The temporal proteomic changes in the myocardium indicate a short-lived sterile inflammatory response consistent with ischemia or contusion. Further study of myocardial function and strain is needed to determine if pFUS could be developed as an experimental model of cardiac injury and chest trauma.

     

Screening for Abdominal Aortic Aneurysm during Transthoracic Echocardiography in Patients with Significant Coronary Artery Disease

Purpose

Coronary artery disease (CAD) shares several risk factors with abdominal aortic aneurysm (AAA). We evaluated the prevalence during transthoracic echocardiography (TTE) and risk factors of AAA in patients with CAD.

Materials and Methods

A total of 1300 CAD patients were screened from August 2009 to May 2010, and measurement of abdominal aorta size was feasible in 920 patients (71%) at the end of routine TTE. An AAA was defined as having a maximal diameter of ≥30 mm.

Results

Of the 920 patients, 22 (2.4% of the study population) were diagnosed with AAA; of these AAA patients, 86% were male, and 82% were over 65 years-old. Abdominal aortic size was weakly correlated with aortic root diameter (r=0.22, p<0.01). Although the proportions of male gender, hypertension, and dyslipidemia were higher in AAA patients, such differences were not statistically significant. Advanced age [odds ratio (OR)=1.07; 95% confidence interval (CI): 1.01-1.12; p<0.01], smoking (OR=3.44; 95% CI: 1.18-10.04; p=0.02), and peripheral arterial disease (OR=5.88; 95% CI: 1.38-25.05; p=0.01) were found to be associated with AAA.

Conclusion

Although prevalence of AAA is very low in the Asian population, the prevalence of AAA in Asian CAD patients is higher than the general population. Therefore, opportunistic examination of the abdominal aorta during routine TTE could be effective, especially for male CAD patients over 65 years with a history of smoking or peripheral arterial disease.     

Effect of Triflusal on Primary Vascular Dysregulation Compared with Aspirin: A Double-Blind,Randomized, Crossover Trial

Purpose

Primary vascular dysregulation (PVD) is a condition in which the response to cold temperature or external stimuli is abnormal. We investigated whether triflusal use results in amelioration of PVD symptoms and improvement of several related parameters compared with aspirin.

Materials and Methods

Eighty-eight PVD patients (54% female, 56±8 years) were randomly selected to receive either triflusal (300 mg, b.i.d.) or aspirin (150 mg, b.i.d.) for a period of 6 weeks followed by crossover. PVD was defined as both red-blood-cell standstill in video-assisted microscopic capillaroscopy during cold stimulation using carbon dioxide gas and a score of more than 7 points in a validated questionnaire. Efficacy of treatment was assessed by 1) cold intolerance symptom severity (CISS) score, 2) finger Doppler indices, and 3) indocyanine green perfusion imaging.

Results

The use of triflusal resulted in a greater improvement in CISS score (44.5±18.4 vs. 51.9±16.2; p<0.001) and in mean radial peak systolic velocity (69.8±17.2 vs. 66.1±16.4; p=0.011) compared to aspirin. Furthermore, significant differences were also observed in perfusion rates on indocyanine green perfusion imaging between triflusal and aspirin (45.6±25.8 vs. 51.6±26.9; p=0.020).

Conclusion

Triflusal was more effective and demonstrated a more consistent impact on the improvement of symptoms and blood flow in patients with PVD than aspirin.