Cardiopulmonary Protection for Bilateral Breast Irradiation: A Dosimetric Comparison between Proton and Photon Plans

PURPOSE/OBJECTIVE(S)

Recent advances in cancer treatment improve cancer survivorship. Cardiovascular disease has become the leading cause of non-cancer death in breast cancer survivors. Therefore, risk of cardiopulmonary toxicities during multimodality treatment should be assessed carefully. It remains to be defined the best scenario for proton therapy to confer meaningful cardiovascular protection in the setting of breast irradiation. We hypothesized proton therapy plan provides optimal cardiopulmonary protection during bilateral breast irradiation. The study aimed to compare cardiopulmonary dosimetric parameters of proton and photon radiotherapy plans.

MATERIALS/METHODS

We conducted a retrospective study and patients with bilateral breast cancer indicated for radiotherapy between January 01, 2010 and December 31, 2020 were included. All patients received whole breast or chest wall irradiation with or without regional nodal irradiation. The dose scheme was 50-50.4 Gy in 25-28 fractions. Boost was allowed if patients receiving breast conserving surgery or known risk factors. The dosimetric parameters included planning target volume, mean dose to the heart, the volume of whole lung receiving 5 Gy, 10 Gy, and 20 Gy. For photon therapy, volumetric modulated arc therapy using double partial arc plans was generated with Pinnacle 9.8, Elekta Synergy and tomotherapy helical plan was generated with Tomo Hi-Art planning system. For proton therapy, treatment planning was generated with Ray station 9A. All data was managed using SAS v.9.4 software. Analysis of variance (α = 0.05) was used to compute the dosimetry of different treatment modalities. The statistical significance was considered with a p-value <0.05.

RESULTS

Thirty-one patients with bilateral breast cancer were included, including 12 bilateral breast irradiation patients and 6 bilateral chest wall irradiation patients. The mean dose of heart was 53.0±43.3 cGy in proton therapy while 736.6±225.1 cGy and 869.67±241.0 cGy in Tomotherapy and volumetric modulated arc therapy respectively. The volume of whole lung receiving 5 Gy was 15.4±7.91% in proton therapy while 46.1±10.8% and 46.3±2.5% in Tomotherapy and volumetric modulated arc therapy respectively. The volume of whole lung receiving 20 Gy was 7.7±4.3% in proton therapy while 15.4±5.6% and 19±3.5% in Tomotherapy and volumetric modulated arc therapy respectively. The effects of cardiopulmonary protection were more significant for chest wall irradiation over breast irradiation.

CONCLUSION

Proton radiotherapy provided significant dose reduction for bilateral breast irradiation. The benefit is more significant is patients receiving bilateral chest wall irradiation. Further clinical validations will be warranted to confirm the clinical relevance of the finding.

Safety Profile of Combination Treatment with Radiotherapy and Immune Checkpoint Blockades: A Multi-Institute Real World Experience

PURPOSE/OBJECTIVE(S)

Immune checkpoint blockades have become widely used in recent years and have been approved as standard first-line and subsequent treatment for different types of malignancy. Combination treatment with irradiation also showed promising results in previous clinical studies. However, the treatment toxicities of this combination strategy have not been well defined. We hypothesized combination therapy does not add additional toxicities to immune checkpoint blockade alone. The study aims to investigate the safety profile of combination treatment with immune checkpoint blockade and radiotherapy in all type cancer patients.

MATERIALS/METHODS

We conducted a population-based retrospective cohort study using the electronic medical records from three hospitals in Taiwan from January 01, 2015, to December 31, 2020. Baseline demographic data, laboratory examination, and treatment history were collected. Patients with radiotherapy exposure and immune checkpoint blockade were enrolled. The primary endpoint was all grade toxicities. All patients were monitored from the date of initiating immune checkpoint blockade or irradiation until the event of death, loss follow-up, or any defined adverse events. All data was managed using SAS v.9.4 software. Kaplan-Meier estimators and cox proportional hazard regression models were used to compute the safety profile of combination treatment. The statistical significance was considered with a p-value <0.05.

RESULTS

A total of 305 cases, including 181 male patients and 124 female patients, received combination treatment with immune checkpoint blockade and radiotherapy with different time sequences. The most common cancer types are lung cancer (33.1%) followed by gastroesophageal cancer (16.7%) and hepatobiliary cancer (13.8%). The most common toxicities were arthralgia (25.9%), followed by enterocolitis (23.6%), and anemia (21%). 11 cases (3.6%) developed pneumonitis, 5 cases (1.6%) developed myocarditis, and 5 cases (1.6%) developed hepatitis during combination treatment.

CONCLUSION

There is no evidence leads to additional toxicities based on current real-world experience. Severe immune related adverse events were not increased with this combination strategy compared to historical data. This warrant further prospective analysis.

[To compare the efficacy and incidence of severe hematological adverse events of flumatinib and imatinib in patients newly diagnosed with chronic phase chronic myeloid leukemia]

Objective: To analyze and compare therapy responses, outcomes, and incidence of severe hematologic adverse events of flumatinib and imatinib in patients newly diagnosed with chronic phase chronic myeloid leukemia (CML) . Methods: Data of patients with chronic phase CML diagnosed between January 2006 and November 2022 from 76 centers, aged ≥18 years, and received initial flumatinib or imatinib therapy within 6 months after diagnosis in China were retrospectively interrogated. Propensity score matching (PSM) analysis was performed to reduce the bias of the initial TKI selection, and the therapy responses and outcomes of patients receiving initial flumatinib or imatinib therapy were compared. Results: A total of 4 833 adult patients with CML receiving initial imatinib (n=4 380) or flumatinib (n=453) therapy were included in the study. In the imatinib cohort, the median follow-up time was 54 [interquartile range (IQR), 31-85] months, and the 7-year cumulative incidences of CCyR, MMR, MR(4), and MR(4.5) were 95.2%, 88.4%, 78.3%, and 63.0%, respectively. The 7-year FFS, PFS, and OS rates were 71.8%, 93.0%, and 96.9%, respectively. With the median follow-up of 18 (IQR, 13-25) months in the flumatinib cohort, the 2-year cumulative incidences of CCyR, MMR, MR(4), and MR(4.5) were 95.4%, 86.5%, 58.4%, and 46.6%, respectively. The 2-year FFS, PFS, and OS rates were 80.1%, 95.0%, and 99.5%, respectively. The PSM analysis indicated that patients receiving initial flumatinib therapy had significantly higher cumulative incidences of CCyR, MMR, MR(4), and MR(4.5) and higher probabilities of FFS than those receiving the initial imatinib therapy (all P<0.001), whereas the PFS (P=0.230) and OS (P=0.268) were comparable between the two cohorts. The incidence of severe hematologic adverse events (grade≥Ⅲ) was comparable in the two cohorts. Conclusion: Patients receiving initial flumatinib therapy had higher cumulative incidences of therapy responses and higher probability of FFS than those receiving initial imatinib therapy, whereas the incidence of severe hematologic adverse events was comparable between the two cohorts.

A92 FEMALE AUTHORSHIP IN GASTROENTEROLOGY RANDOMIZED CONTROL TRIALS: 2011 - 2021

Background

Although tremendous strides have been made in the participation of women in medicine, female continues to be underrepresented in leadership positions and higher-level academic medicine. An important factor in determining career advancement in academic medicine is the quality and quantity of an individual’s scholarly publications. To date, no study has looked at female authorship in gastroenterology (GI) randomized control trials (RCTs), which remains the gold standard for evaluating intervention effectiveness.

Purpose

The primary outcome is to assess female authorship in gastroenterology randomized control trials from 2011 to 2021, and the secondary outcome is to assess female authorship within GI subspecialty RCT publications.

Method

In this observational study, the gender of the first and last author of gastroenterology RCTs from January 1, 2011 to December 31, 2021 was assessed. Python (v3.8.12) was used to extract publication data from PubMed. A validated algorithm, genderize.io, was used to determine gender. Author first names that cannot be determined by the algorithm were manually searched on publicly-available profiles.

Result(s)

A total of 5690 original gastroenterology RCTs were included from January 1, 2011 to December 31, 2021. The gender of the first and senior authors of the papers was determined for 5668 (99.6%) first authors and 5656 (99.4%) senior authors. Overall, 1937 (34.1%) of the first authors and 1138 (20.0%) of senior authors were female.

There was an increase in the proportion of female first authors over the past decade, from 25.4% in 2011 to 37.8% in 2021 (p<0.05). For senior authors, there was a more gradual increase in female authorship from 14.2% in 2011 to 21.6% in 2021 (p<0.05). (Figure 1)

Within GI subspecialties, 612 RCTs were included for inflammatory bowel disease, 1143 RCTs were included for hepatology, and 1856 RCTs were included for therapeutic endoscopy from January 1, 2011 to December 31, 2021. Further analysis will be performed to determine the gender trend for GI subspecialties.

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Conclusion(s)

Female authorship in gastroenterology RCTs has increased from 2011 to 2021, although the rate of senior authorship has increased to a slower extent compared to first authors. Across all years, female authorship in gastroenterology RCTs has been lower than males.

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Disclosure of Interest

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A127 TIMING OF CHOLECYSTECTOMY AFTER ENDOSCOPIC RETROGRADE CHOLANGIOPANCREATOGRAPHY IN A TERTIARY CENTRE: EVALUATION OF OUTCOMES

Background

Endoscopic retrograde cholangiopancreatography (ERCP) is the treatment of choice for patients with choledocholithiasis. Early cholecystectomy (within 24 to 72 hours) is recommended after the initial ERCP to reduce the risk of subsequent biliary events.

Purpose

To investigate the timing of cholecystectomy after ERCP in patients with choledocholithiasis and its associated outcomes in a single tertiary care centre.

Method

This is a retrospective analysis of adult patients who underwent cholecystectomy after ERCP from August 2021 to April 2022 at the University of Alberta Hospital. Outcomes data were stratified according to the length of time between ERCP and cholecystectomy, within 72 hours (early) or after 72 hours (delayed).

Result(s)

During the study period, 55 subjects were examined. Indications for ERCP included gallstone pancreatitis (24/55, 44%), choledocholithiasis (19/55, 34%), and acute cholangitis (12/55, 21%).

In total, 30 (55%) subjects received cholecystectomy within 72 hours, while 25 (45%) subjects received cholecystectomy after 72 hours. The two groups were comparable in age, sex ratios, and comorbidities. Out of the patients who received cholecystectomy after 72 hours, 8 (32%) subjects received their cholecystectomy on a subsequent admission. Of these, 2 subjects developed recurrent biliary events before their cholecystectomy, and 1 subject required a conversion to open cholecystectomy. There were no recurrent biliary events amongst the individuals with early cholecystectomy.

Subjects who received early cholecystectomy had a shorter total hospital stay compared to those with delayed cholecystectomy (4.5 days vs 7.3 days, p=0.0002). There was no significant difference between early and late cholecystectomy in conversion rate (3% vs 8%, p=0.58), average operating time (86min vs 83min, p=0.79), intraoperative complications including adhesions (13% vs 12%, p>0.05) and empyema (27% vs 28%, p>0.05), as well as histological rate of chronic cholecystitis (88% vs 92%, p=0.68).

Reasons associated with significantly delayed (>7 days) cholecystectomy after ERCP (n=12) include requiring coordination/consultation with other services prior to operation (3 subjects), prolonged course of gallstone pancreatitis (3 subjects), poor candidate for operation due to comorbidities (2 subjects), surgical cancellation/delays (2 subjects), post-ERCP pancreatitis (1 subject), and patient preference (1 subject).

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Conclusion(s)

Early cholecystectomy is associated with a shorter length of hospital stay and absence of recurrent biliary events. Other post-cholecystectomy outcomes were comparable. Early laparoscopic cholecystectomy should continue to be encouraged through an interdisciplinary approach.

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Disclosure of Interest

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Pharmacotherapy decisions among postmenopausal women attending a group medical consultation or a one-on-one specialist consultation at an osteoporosis center: an observational cohort study

Group medical visits for osteoporosis can improve access to care while being highly accepted by patients. In this study, a similar proportion of women planned to initiate pharmacotherapy after attending a group or traditional one-on-one osteoporosis consultation, indicating that the group consultation model does not produce unexpected treatment decisions.

INTRODUCTION

Group medical consultations for osteoporosis are time-efficient and highly accepted by patients, but effects on treatment decisions are unknown. We aimed to compare women's decisions to initiate or decline osteoporosis pharmacotherapy after attending either a group or transitional one-on-one osteoporosis consultation.

METHODS

In this observational study, we prospectively evaluated postmenopausal women referred to an osteoporosis clinic who attended a group medical visit and compared their decisions regarding pharmacologic osteoporosis treatment with retrospective data from a cohort of women who attended a traditional consultation. Both consultation types involved interaction with a specialist physician, individualized fracture risk estimation (using FRAX®), and education regarding fracture consequences and available osteoporosis medications. Both forms of consultation emphasized shared decision-making; however, group consultation attendees did not receive personalized treatment recommendations from the physician.

RESULTS

We reviewed the records of 125 women (median age 63 years) who attended a group consultation and 83 women (median age 64 years) who attended a traditional consultation between 2016 and 2019. Twenty-four (19%) of the group cohort and 16 (19%) of the traditional cohort were at high 10-year risk of major osteoporotic fracture (FRAX® ≥ 20.0%). A similar proportion planned to initiate pharmacologic therapy after the group and traditional consultations (23% vs 16%, p = 0.22); these proportions were comparable among women at high risk (42% vs 50%, p = 0.75) and moderate risk (19% vs 15%, p = 0.77), but a higher proportion of low-risk women planned to initiate therapy after the group consultation (18% vs 0%, p = 0.009).

CONCLUSION

Patient decisions to initiate pharmacologic treatment made during a group visit are similar to those made during traditional one-on-one consultation. The group consultation model represents an alternative to one-on-one assessment for delivering osteoporosis consultative services.

Randomized trial of radiotherapy with weekly cisplatin or cetuximab in low risk HPV associated oropharyngeal cancer (TROG 12.01): A Trans-Tasman Radiation Oncology Group study

6012

Background: The excellent prognosis of patients with low risk HPV associated oropharyngeal squamous cell carcinoma has led to concerns about overtreatment and excessive toxicity with radiotherapy and cisplatin, leading to interest in de-intensification trials. We investigated whether cetuximab, an EGFR targeting antibody, when combined with radiotherapy would result in a decrease in symptom burden and toxicity with similar efficacy when compared to weekly cisplatin. Methods: TROG 12.01, a randomised, multicentre trial involving 15 sites in Australia and New Zealand enrolled patients with HPV associated oropharyngeal squamous cell carcinoma, AJCC 7th edition Stage III (excluding T1-2N1) or stage IV (excluding T4 and/or N3 and/or N2b-c if smoking history >10 pack years and/or distant metastases). Patients were randomised (1:1) to receive radiotherapy (70Gy in 35 fractions) with either weekly cisplatin, 7 doses of 40mg/m2 or cetuximab, loading dose of 400mg/m2 followed by 7 weekly doses of 250 mg/m2. The primary outcome was symptom severity assessed by the MD Anderson Symptom Inventory Head and Neck Symptom Severity Scale from baseline to 13 weeks post completion of radiotherapy using the area under the time-severity curve (AUC). Sample size was 170 evaluable patients to provide at least 90% power to detect an effect size of 0.5, using a 2-sided test at 0.05 level of significance. Trial was registered on ClinicalTrials.gov: NCT01855451. Results: Between 17th June 2013 and 7th June 2018, 189 patients were enrolled and 182 were evaluable, with 92 on cisplatin arm and 90 on cetuximab included in the main analysis. The median follow-up was 4.1 years (0.4 - 5.3). Analyses were performed in all eligible randomised patients that commenced treatment (modified intention-to-treat population). There was no difference in the primary endpoint of symptom severity; difference in AUC cetuximab – cisplatin was 0.05 (95%CI: -0.19, 0.30), p= 0.66. The T-score (mean number of > grade 3 acute adverse events) was 4.35 (SD 2.48) in the cisplatin arm and 3.82 (SD 1.8) in the cetuximab arm, p= 0.108. The 3 -year failure-free survival rates were 93% (95% CI: 86-97%) in the cisplatin arm and 80% (95% CI: 70-87%) in the cetuximab arm (hazard ratio = 3.0 (95% CI: 1.2-7.7); p=0.015. The increase in failures in the cetuximab arm was evenly split between distant and locoregional failures. Conclusions: For patients with low risk HPV associated oropharyngeal cancer, radiotherapy and cetuximab had inferior failure-free survival without improvement in symptom burden or toxicity compared to radiotherapy and weekly cisplatin. Radiotherapy and cisplatin remains the standard of care. Clinical trial information: NCT01855451.

Predictive model of hydrogen trapping and bubbling in nanovoids in bcc metals

The interplay between hydrogen and nanovoids, despite long being recognized as a central factor in hydrogen-induced damage in structural materials, remains poorly understood. Here, focusing on tungsten as a model body-centred cubic system, we explicitly demonstrate sequential adsorption of hydrogen adatoms on Wigner-Seitz squares of nanovoids with distinct energy levels. Interaction between hydrogen adatoms on nanovoid surfaces is shown to be dominated by pairwise power-law repulsion. We establish a predictive model for quantitative determination of the configurations and energetics of hydrogen adatoms in nanovoids. This model, combined with the equation of states of hydrogen gas, enables the prediction of hydrogen molecule formation in nanovoids. Multiscale simulations, performed based on our model, show good agreement with recent thermal desorption experiments. This work clarifies fundamental physics and provides a full-scale predictive model for hydrogen trapping and bubbling in nanovoids, offering long-sought mechanistic insights that are crucial for understanding hydrogen-induced damage in structural materials.

The impacts of the quantum-dot confining potential on the spin-orbit effect

For a nanowire quantum dot with the confining potential modeled by both the infinite and the finite square wells, we obtain exactly the energy spectrum and the wave functions in the strong spin-orbit coupling regime. We find that regardless of how small the well height is, there are at least two bound states in the finite square well: one has the σ ^x [Formula: see text] = -1 symmetry and the other has the σ ^x [Formula: see text] = 1 symmetry. When the well height is slowly tuned from large to small, the position of the maximal probability density of the first excited state moves from the center to x ≠ 0, while the position of the maximal probability density of the ground state is always at the center. A strong enhancement of the spin-orbit effect is demonstrated by tuning the well height. In particular, there exists a critical height [Formula: see text], at which the spin-orbit effect is enhanced to maximal.

Peripheral cytokine and chemokine alterations in depression: a meta-analysis of 82 studies

OBJECTIVE

To conduct a systematic review and meta-analysis of studies that measured cytokine and chemokine levels in individuals with major depressive disorder (MDD) compared to healthy controls (HCs).

METHOD

The PubMed/MEDLINE, EMBASE, and PsycINFO databases were searched up until May 30, 2016. Effect sizes were estimated with random-effects models.

RESULT

Eighty-two studies comprising 3212 participants with MDD and 2798 HCs met inclusion criteria. Peripheral levels of interleukin-6 (IL-6), tumor necrosis factor (TNF)-alpha, IL-10, the soluble IL-2 receptor, C-C chemokine ligand 2, IL-13, IL-18, IL-12, the IL-1 receptor antagonist, and the soluble TNF receptor 2 were elevated in patients with MDD compared to HCs, whereas interferon-gamma levels were lower in MDD (Hedge's g = -0.477, P = 0.043). Levels of IL-1β, IL-2, IL-4, IL-8, the soluble IL-6 receptor (sIL-6R), IL-5, CCL-3, IL-17, and transforming growth factor-beta 1 were not significantly altered in individuals with MDD compared to HCs. Heterogeneity was large (I² : 51.6-97.7%), and sources of heterogeneity were explored (e.g., age, smoking status, and body mass index).

CONCLUSION

Our results further characterize a cytokine/chemokine profile associated with MDD. Future studies are warranted to further elucidate sources of heterogeneity, as well as biosignature cytokines secreted by other immune cells.

Econazole induces increases in free intracellular Ca2+ concentrations in human osteosarcoma cells

Econazole is an antifungal drug with different in vitro effects. However, econazole's effect on osteoblast like cells is unknown. In human MG63 osteosarcoma cells, the effect of econazole on intracellular Ca2+ concentrations ([Ca2+]i) was explored by using fura-2. At a concentration of 0.1 μM, econazole started to cause a rise in [Ca2+]i in a concentration-dependent manner. Econazole-induced [Ca2+]i rise was reduced by 74% by removal of extracellular Ca2+. The econazole-induced Ca2+ influx was mediated via a nimodipine-sensitive pathway. In Ca2+ free medium, thapsigargin, an inhibitor of the endoplasmic reticulum Ca2+ ATPase, caused a [Ca2+]i rise, after which the increasing effect of econazole on [Ca2+]i was abolished. Pretreatment of cells with econazole to deplete Ca2+ stores totally prevented thapsigargin from releasing Ca2+. U73122, an inhibitor of phospholipase C, abolished histamine (an inositol 1,4,5-trisphosphate dependent Ca2+ mobilizer)-induced, but not econazoleinduced, [Ca2+]i rise. Econazole inhibited 76% of thapsigargin-induced store-operated Ca2+ entry. These findings suggest that in MG63 osteosarcoma cells, econazole increases [Ca2+]i by stimulating Ca2+ influx and Ca2+ release from the endoplasmic reticulum via a phospholipase C-independent manner. In contrast, econazole acts as a potent blocker of store-operated Ca2+ entry.

Energetic and kinetic dataset on interaction of the vacancy and self-interstitial atom with the grain boundary in α-iron

We provide the dataset of the vacancy (interstitial) formation energy, segregation energy, diffusion barrier, vacancy-interstitial annihilation barrier near the grain boundary (GB) in bcc-iron and also the corresponding interactive range. The vacancy-interstitial annihilation mechanisms in the bulk, near the GB and at the GB at across scales were given.

Extraordinary high ductility/strength of the interface designed bulk W-ZrC alloy plate at relatively low temperature

The refractory tungsten alloys with high ductility/strength/plasticity are highly desirable for a wide range of critical applications. Here we report an interface design strategy that achieves 8.5 mm thick W-0.5 wt. %ZrC alloy plates with a flexural strength of 2.5 GPa and a strain of 3% at room temperature (RT) and ductile-to-brittle transition temperature of about 100 °C. The tensile strength is about 991 MPa at RT and 582 MPa at 500 °C, as well as total elongation is about 1.1% at RT and as large as 41% at 500 °C, respectively. In addition, the W-ZrC alloy plate can sustain 3.3 MJ/m² thermal load without any cracks. This processing route offers the special coherent interfaces of grain/phase boundaries (GB/PBs) and the diminishing O impurity at GBs, which significantly strengthens GB/PBs and thereby enhances the ductility/strength/plasticity of W alloy. The design thought can be used in the future to prepare new alloys with higher ductility/strength.

Nanostructured fuzz growth on tungsten under low-energy and high-flux He irradiation

We report the formation of wave-like structures and nanostructured fuzzes in the polycrystalline tungsten (W) irradiated with high-flux and low-energy helium (He) ions. From conductive atomic force microscope measurements, we have simultaneously obtained the surface topography and current emission images of the irradiated W materials. Our measurements show that He-enriched and nanostructured strips are formed in W crystal grains when they are exposed to low-energy and high-flux He ions at a temperature of 1400 K. The experimental measurements are confirmed by theoretical calculations, where He atoms in W crystal grains are found to cluster in a close-packed arrangement between {101} planes and form He-enriched strips. The formations of wave-like structures and nanostructured fuzzes on the W surface can be attributed to the surface sputtering and swelling of He-enriched strips, respectively.

Using hydrological simulation to detect human-disturbed epoch in runoff series

Runoff in major rivers in China has been decreasing in recent decades, mainly due to climate change and human activity. River basin managers have a critical interest in detecting and diagnosing non-stationaries in runoff time series. Here we use a rainfall runoff model-based approach to identify the human-disturbed periods of the record. The method is applied to the Kuye River catchment, located in the Loess Plateau, China. The SimHyd model performs well for simulation of monthly natural discharges, and the method suggests that discernable human influence began in 1980. Anthropogenic effects were detectable several years earlier at the downstream stations than the upstream stations, consistent with pace and timing of soil and water conservation measures implemented across the Kuye River catchment.

Origin of the crossover in dynamics of the sub-Rouse modes at the same temperature as the structural α-relaxation in polymers

The nature of the liquid-glass transition remains an unsolved fundamental problem. One aspect is the striking change in dynamics of the structural α-relaxation generally observed at a temperature T(B) above Tg in all glass-formers. More intriguing in the case of polymers is that the change of dynamics occurs not only in the structural α-relaxation but also in the sub-Rouse modes, i.e. chain modes in between the α-relaxation and the Rouse modes. However, the nature of the dynamic crossover of the sub-Rouse modes remains unclear. In this paper, the dynamics of a series of poly(n-alkyl methacrylates) with different molecular weights and microstructures studied by mechanical spectroscopy are reported. We demonstrate that the sub-Rouse modes exhibit a similar crossover of dynamics at the same T(B) as the α-relaxation. This property shared by the two viscoelastic mechanisms is remarkable. By invoking the results from the studies using positron annihilation spectroscopy and adiabatic calorimetry, we show that both viscoelastic mechanisms are coupled to density, correlated with the change of the configuration entropy, and are intermolecularly cooperative. The time scale of sub-Rouse modes at T(B) of the polymers studied is approximately independent of molecular weight and micro-structure of the polymers studied. The findings enhance the understanding of the sub-Rouse modes and their manifestation in the viscoelasticity of polymers in the glass-rubber transition region.

A universal scaling law of grain chain elasticity under pressure revealed by a simple force vibration method

The grain contact force, the key player in determining the mechanical properties of grain materials, depends on the elastic modulus and deformation (δ) of grains. However, our knowledge on their relationship in a three-dimensional granular medium is limited mainly owing to the difficulty of realizing direct experimental investigation. Using a simple force vibration technique, we measure the dissipation spectra (the frequency response) of three kinds of grains with different elastic moduli under different pressures (to change the grain deformation). The dissipation spectra exhibit multiple resonant peaks, indicative of the resonance of grain chains with different lengths. This allows us to quantitatively characterize the elastic behaviors of grain chains. A universal correlation of the resonant frequency (f) of a grain chain with deformation is observed for all granular systems with different material properties (Young's modulus E, density ρ and Poisson's coefficient ν): f(2) ∝ δ(1/2)E/ρ(1 - ν). The deformation of the grain chain under pressure follows a p(2/3) pressure dependence. This general behavior suggests that the pressure-induced deformation of the grain chain under low-frequency weak shear vibration is overwhelmed by the nonlinear Hertzian contact elasticity.

Unruptured saccular aneurysm presenting migraine

Headache can be attributed to cranial or cervical vascular disorders including ischemic stroke or transient ischemic attack, non-traumatic intracranial hemorrhage, unruptured vascular malformation, arteritis, carotid-vertebral artery pain, and cerebral venous thrombosis. Here, we present a case report of unruptured saccular aneurysm with migraine. The patient was a previously healthy 32-year-old man with repeated episodes of headache for 6 years. Findings for computed tomography and magnetic resonance imaging of the head were normal. Head magnetic resonance angiography revealed a small, nodule-like protuberance seen in the anterior communicating artery. Based on his clinical features and ancillary examinations, the patient was diagnosed with migraine without aura. The patient subsequently underwent digital subtraction angiography (DSA), which revealed a 2-mm cystic protuberance in the superoposterior anterior communicating artery. The patient underwent stent-assisted coil embolization of the aneurysm. Subsequent DSA results indicated no recurrence of aneurysm and no recurrence of headache was reported after surgical treatment.

Possible s±-wave pairing evidenced by midgap surface bound states in Fe-pnictide superconductors

A phenomenological theory of tunneling spectroscopy for Fe-pnictide superconductors is developed by taking into consideration asymmetric interface scattering between particle and holes. It is shown that, consistent with anti-phase s(±)-wave pairing, appreciable zero-energy surface bound states exist on the [100] surface of Fe-pnictide superconductors. However, in contrast to the [110] bound states in d-wave cuprate superconductors, these bound states arise as a result of non-conservation of momentum perpendicular to the interface for tunneling electrons and the s(±) pairing, and hence they can only exist in a small window (~ ± 6°) in the orientation of edges near the [100] direction. Our results explain why a zero-bias conductance peak is often observed in tunneling spectroscopy and why, when it disappears, two coherent peaks show up. These results provide unambiguous signals to test for possible s(±)-wave pairing in Fe-pnictide superconductors.

A bacteria injection scheme for in situ bioaugmentation

This article presents an innovative design for inoculating the desired organisms to stratified geological layers at desired rates during in-situ bioaugmentation. The new delivery system consists of intermittent porous tubes connected in series with impermeable polyethylene tubes that run horizontally in each stratified layer of a contaminated aquifer. A bioaugmentation test using the new delivery system was conducted to inject an enriched culture of Escherichia coli (E. coli). Results of the test indicated that the distribution of E. coli through each porous tube was fairly uniform. A mathematical model previously developed to calculate the distribution of water flow through each porous tube was modified to calculate the distribution of E. coli. Geological layers often have different hydraulic conductivities. By controlling the permeability and the length of porous tubes placed in stratified layers, the new design provides a means to selectively deliver aqueous bacteria to various layers at desired rates according to aquifer heterogeneity.

Interplay between periodicity and nonlinearity of indirect excitons in coupled quantum wells

Inspired by a recent experiment of localization-delocalization transition (LDT) of indirect excitons in lateral electrostatic lattices (Remeika et al 2009 Phys. Rev. Lett. 102 186803), we theoretically investigate the interplay between periodic potential and nonlinear interactions of indirect excitons in coupled quantum wells. It is shown that the model involving both attractive two-body and repulsive three-body interactions can lead to a natural account for the LDT of excitons across the lattice when reducing lattice amplitude or increasing particle density. In addition, the observations that the smooth component of the photoluminescent energy increases with increasing exciton density and that the exciton interaction energy is close to the lattice amplitude at the transition are also qualitatively explained. Our model provides an alternative way of understanding the underlying physics of the exciton dynamics in lattice potential wells.

Plasmoid ejection and secondary current sheet generation from magnetic reconnection in laser-plasma interaction

Reconnection of the self-generated magnetic fields in laser-plasma interaction was first investigated experimentally by Nilson et al. [Phys. Rev. Lett. 97, 255001 (2006)] by shining two laser pulses a distance apart on a solid target layer. An elongated current sheet (CS) was observed in the plasma between the two laser spots. In order to more closely model magnetotail reconnection, here two side-by-side thin target layers, instead of a single one, are used. It is found that at one end of the elongated CS a fanlike electron outflow region including three well-collimated electron jets appears. The (>1 MeV) tail of the jet energy distribution exhibits a power-law scaling. The enhanced electron acceleration is attributed to the intense inductive electric field in the narrow electron dominated reconnection region, as well as additional acceleration as they are trapped inside the rapidly moving plasmoid formed in and ejected from the CS. The ejection also induces a secondary CS.

Oxidative degradation of propachlor by ferrous and copper ion activated persulfate

The process of in situ chemical oxidation (ISCO) by persulfate (S(2)O(8)(2-)) can be accelerated by metal ion activation, which more effectively degrades subsurface pollutants by enhancing sulfate radical (SO(4)(-)) generation. This study compared the results of propachlor degradation by Cu(2+) and Fe(2+) activated persulfate and revealed differing degradation kinetics and mechanisms between the two types of activation system. The activation of persulfate by Fe(2+) ions generally resulted in rapid degradation in the early stage, but was accompanied by a dramatic decrease in efficiency due to the rapid depletion of Fe(2+) by the sulfate radicals generated. In contrast, the Cu(2+) activated persulfate had a longer lasting degradation effect and a proportionally greater degradation enhancement at elevated Cu(2+) concentrations. An optimal Fe(2+) concentration should be sought to activate the persulfate, as a high Fe(2+) concentration of 2.5mM or above, as was used in this study, may inhibit propachlor degradation due to the competitive consumption of sulfate radicals by the excess Fe(2+) ions. Higher temperatures (55°C compared with 30°C) resulted in enhanced metal activation, particularly with the Cu(2+) activated system. Furthermore, acidic conditions were found to be more favorable for propachlor degradation by metal activated persulfate. The ecotoxicity of degraded propachlor samples, which was indicated by average well color development (AWCD) for its microbial community activity, was confirmed to be decreased during the degradation processes with these two ions activated persulfate.

Kinetics and mechanism of propachlor reductive transformation through nucleophilic substitution by dithionite

Chloroacetanilide herbicides are extensively used in the control of weeds and have widely resulted in nonpoint contamination of groundwater and soil resources. In the attempt to achieve better remediation for herbicide-contaminated resources, we investigated the reductive transformation of propachlor through nucleophilic substitution by dithionite (S(2)O(4)(2-)). Results showed that propachlor underwent rapid dechlorination in the presence of dithionite. The reaction was of second-order kinetics and strongly influenced by pH and temperature. At pH 7.0 and temperature 308K, the rate constant of propachlor dechlorination was estimated at 123.4±0.7M(-1)h(-1). Within the pH range tested (3.0-9.5), higher pH promoted the ionization of dithionite, resulting in a more active nucleophilic reagent of S(2)O(4)(2-) to enhance the propachlor transformation rate. Similarly, higher reaction temperature overcame the activation barrier of steric hindrance in propachlor structure and accelerated the excitation of dithionite, in which higher rate constants of propachlor reductive dechlorination were obtained. Dechlorination was found to be the first and necessary step of propachlor nucleophilic substitution by dithionite. Sulfur nucleophile substituted compounds, including propachlor dithionite, propachlor ethanesulfonic acid (ESA), and hydroxyl propachlor, were identified as the dechlorination products of propachlor, indicating bimolecular nucleophilic substitution (S(N)2) as the mechanism for propachlor transformation initiated by dithionite.

Genetic evaluation and management of fetal chylothorax: review and insights from a case of Noonan syndrome

Fetal chylothorax is one of a very few syndromes that can be treated in utero with thoracoamniotic shunting or pleurodesis by OK-432 as two major therapeutic modalities. We report on a fetus with Noonan syndrome and a missense mutation c.182A > C (p.Asp61Ala) of PTPN11 who responded poorly to antenatal pleurodesis by OK-432. Based on our previous publication and this case study, we propose that fetal chylothorax of a distinct genetic origin may respond poorly to OK-432 pleurodesis.

Photodegradation of polycyclic aromatic hydrocarbon pyrene by iron oxide in solid phase

To better understand the photodegradation of polycyclic aromatic hydrocarbons (PAH) in solid phase in natural environment, laboratory experiments were conducted to study the influencing factors, kinetics and intermediate compound of pyrene photodegradation by iron oxides. The results showed that the pyrene photodegradation rate followed the order of alpha-FeOOH>alpha-Fe(2)O(3)>gamma-Fe(2)O(3)>gamma-FeOOH at the same reaction conditions. Lower dosage of alpha-FeOOH and higher light intensity increased the photodegradation rate of pyrene. Iron oxides and oxalic acid can set up a photo-Fenton-like system without additional H(2)O(2) in solid phase to enhance the photodegradation of pyrene under UV irradiation. All reaction followed the first-order reaction kinetics. The half-life (t(1/2)) of pyrene in the system showed the higher efficiencies of using iron oxide as photocatalyst to degrade pyrene. Intermediate compound pyreno was found during photodegradation reactions by gas chromatography-mass spectrometry (GC-MS). The photodegradation efficiency for PAHs in this photo-Fenton-like system was also confirmed by using the contaminated soil samples. This work provides some useful information to understand the remediation of PAHs contaminated soils by photochemical techniques under practical condition.

Effect of Celecoxib on Ca2+Fluxes and Proliferation in MDCK Renal Tubular Cells

The effect of celecoxib on renal tubular cells is largely unexplored. In Madin Darby canine kidney (MDCK) cells, the effect of celecoxib on intracellular CaCa2+ concentration ([Ca2+]i) and proliferation was examined by using the Ca(2 +)-sensitive fluorescent dye fura-2 and the viability detecting fluorescent dye tetrazolium, respectively. Celecoxib (> or =1 micro M) caused an increase of [CaCa2+]i in a concentration-dependent manner. Celecoxib-induced [CaCa2+]i increase was partly reduced by removal of extracellular CaCa2+. Celecoxib-induced CaCa2+ influx was independently suggested by MnCa2+ influx-induced fura-2 fluorescence quench. In Ca(2 +)-free medium, thapsigargin, an inhibitor of the endoplasmic reticulum Ca(2 +)-ATPase, caused a monophasic [CaCa2+]i increase, after which celecoxib only induced a tiny [CaCa2+]i increase; conversely, pretreatment with celecoxib completely inhibited thapsigargin-induced [CaCa2+]i increases. U73122, an inhibitor of phospholipase C, abolished ATP (but not celecoxib)-induced [CaCa2+]i increases. Overnight incubation with 1 or 10 micro M celecoxib decreased cell viability by 80% and 100%, respectively. These data indicate that celecoxib evokes a [CaCa2+]i increase in renal tubular cells by stimulating both extracellular CaCa2+ influx and intracellular CaCa2+ release and is highly toxic to renal tubular cells in vitro.

Chitosan/Cellulose Acetate Microspheres Preparation and Ranitidine Release In Vitro

New microspheres containing hydrophilic core and hydrophobic coating as a controlled-release system with no toxic reagents were proposed. Water in oil in water (W/O/W) emulsion and solvent evaporation methods were used to make chitosan/ cellulose acetate (CCA) microspheres sized 200 - 400 microm. Ranitidine hydrochloride, as a model drug, was investigated for its release properties in vitro. The loading efficiency and release rate of ranitidine were affected by chitosan concentration and molecular weight. Higher loadings were obtained at lower concentrations in the interval of 1% to 2%. With chitosan at a 2% concentration microspheres could be obtained with more spherical appearance, smaller size, and higher ranitidine loading efficiency microspheres than at other concentrations. Among the different molecular weight chitosan (47, 145, 308, 499, and 1130 KD) microspheres, the high molecular weight chitosan (1130 KD) microspheres had relatively high loading efficiency (10%). Molecular weight and concentration of chitosan as well as the size of microspheres affected the release of ranitidine. Microspheres smaller than 280 microm released the drug faster than did the bigger by about 10%. The optimal condition for the preparation of the microspheres was chitosan concentration 2%, molecular weight 1130 KD. The ranitidine release from the microspheres was 30% during 48 h in phosphate-buffer saline medium.

Characterization of reflection intermittency in a composite granular chain

The physical factors controlling the power-law behavior of impact energy in a composite granular chain remain elusive. Based on event-driven simulations and the on-off intermittency of wave reflections, we obtain the probability distribution functions of the waiting time tau and the energy leakage DeltaE . They exhibit lognormal distributions, which together with the relationship between DeltaE and tau allow one to explain directly the power-law behavior of the confined energy. This work may be extended to higher dimensions and help us understand the complex dynamics in granular materials.

Effect of alumina on photocatalytic activity of iron oxides for bisphenol A degradation

To study the photodegradation of organic pollutants at the interface of minerals and water in natural environment, three series of alumina-coupled iron oxides (Al(2)O(3)-Fe(2)O(3)-300, Al(2)O(3)-Fe(2)O(3)-420, and Al(2)O(3)-Fe(2)O(3)-550) with different alumina fraction were prepared and characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) and Barret-Joyner-Halender (BJH), and Fourier transform infrared spectra (FTIR). The XRD results showed that existence of alumina in iron oxides could hinder the formation of maghemite and hematite, and also the crystal transformation from maghemite to hematite during sintering. It has been confirmed that the BET surface area and micropore surface area of Al(2)O(3)-Fe(2)O(3) catalysts increased with an increased dosage of alumina and with decreased sintering temperature. The pore size distribution also depended on the fraction of alumina. Furthermore, all Al(2)O(3)-Fe(2)O(3) catalysts had a mixed pore structure of micropore, mesopore and macropore. FTIR results showed that FTIR peaks attributable to Fe-O vibrations of maghemite or hematite were also affected by alumina content and sintering temperature. It was confirmed that the crystal structure and crystalline, the surface area and pore size distribution of Al(2)O(3)-Fe(2)O(3) catalysts depend strongly on the content of alumina and also sintering temperature. Bisphenol A (BPA) was selected as a model endocrine disruptor in aquatic environment. The effects of alumina on the photocatalytic activity of iron oxides for BPA degradation were investigated in aqueous suspension. The experimental results showed that the dependence of BPA degradation on the alumina content was attributable to the crystal structure, crystalline and also the properties of their surface structures. It was confirmed that the mixed crystal structure of maghemite and hematite could achieve the higher photocatalytic activity than maghemite or hematite alone.

Crossover in the power-law behavior of confined energy in a composite granular chain

We present a numerical study of the impact energy decay in a composite granular chain containing two heavy and one light sections. We observe a marked crossover in the power-law behavior of the impact-energy decay. The average reflection frequency first increases with a decreasing acceleration, and arrives at its maximum at "crossing" time then decays almost exponentially. The analysis demonstrates that this phenomenon is related to the structural transition from compression to dilation state in both heavy-particle sections. The further calculations suggest the dependence relation of the power-law exponent (gammacb) in compression state on the mass ratio (m2/m1) and the Hertz law exponent (n) of the composite granular chain gammacb approximately (m2/m1)1/(n+1).

B-group vitamins, MTHFR C677T polymorphism and carotid intima-media thickness in clinically healthy subjects

OBJECTIVE

Plasma B-group vitamins and age may affect the carotid intima-media thickness (IMT) in subjects with different 677TT genotype of the methylenetetrahydrofolate reductase (MTHFR) gene.

DESIGN

A hospital-based cross-study.

SETTING

Genomic and Vascular Center, Changhua Christian Hospital, Changhua, Taiwan.

SUBJECTS

Five hundred and forty-one clinically healthy subjects.

INTERVENTION

Fasting plasma, homocysteine (Hcy), vitamin B(6), vitamin B(12), folate and B-mode carotid ultrasound.

RESULTS

MTHFR genotype, plasma concentrations of folate, vitamin B(6) and vitamin B(12) and age were significantly correlated to the plasma Hcy concentration. MTHFR 677TT carriers had higher concentrations of Hcy than did subjects with the CC and CT genotypes. Age, sex, body mass index and plasma Hcy were independent contributors to increase carotid IMT. However, with stratification by mean value of age and B-group vitamins concentrations, we found that at advanced age, lower plasma folate and vitamin B(12) were three risk factors involved in the enhancing effect of the MTHFR 677TT genotype on the increase of plasma Hcy and carotid IMT.

CONCLUSION

MTHFR 677TT-related carotid atherosclerosis was only identified in healthy elderly subjects with lower level of plasma folate and vitamin B(12).

SPONSORSHIP

Changhua Christian Hospital.

Development of a degradable cement of calcium phosphate and calcium sulfate composite for bone reconstruction

A new type of composite bone cement was prepared and investigated by adding calcium sulfate (CS) to calcium phosphate cement (CPC). This composite cement can be handled as a paste and easily shaped into any contour, which can set within 5-20 min, the setting time largely depending on the liquid-solid (L/S) ratio; adding CS to CPC had little effect on the setting time of the composite cements. No obvious temperature increase and pH change were observed during setting and immersion in simulated body fluid (SBF). The compressive strength of the cement decreased with an increase in the content of CS. The degradation rate of the composite cements increased with time when the CS content was more than 20 wt%. Calcium deficient apatite could form on the surface of the composite cement because the release of calcium into SBF from the dissolution of CS and the apatite of the cement induced the new apatite formation; increasing the content of CS in the composite could improve the bioactivity of the composite cements. The results suggested that composite cement has a reasonable setting time, excellent degradability and suitable mechanical strength and bioactivity, which shows promising prospects for development as a clinical cement.

Calculations of cellular microdosimetry parameters for alpha particles and electrons

The cellular microdosimetry parameters including the cellular S-value and the single-event specific energy distribution for alpha particles and electrons are important in radiation dosimetry and biology. These parameters may be used to determine the relative biological effectiveness of radiations in the boron neutron capture therapy. In the present work, such parameters were calculated for different source to target region combinations, i.e. cell surface, cytoplasm, nucleus and cell. Calculations were made using a semi-analytical model that simulated the emission of alpha particles or electrons by the Monte Carlo method and calculated the energy imparted to the target volume by the analytical method. Delta particle equilibrium and partial delta particle equilibrium were applied to alpha particles and electrons, respectively. Range-energy relations were employed to determine the incident and emerging energies of the primary particles. For electrons, the fraction in the energy loss resulting from the generation of bremsstrahlung and high-energy secondary electrons was estimated. The energy loss straggling of electrons entering and leaving a target volume was also estimated. Calculated cellular S-values were compared to corresponding data of the MIRD Committee. Calculated single-event specific energy distributions were also compared to results calculated using the Penelope code.

Epidemiological and genetic studies of myotonic dystrophy type 1 in Taiwan

To investigate the prevalence and genetic characteristics of myotonic dystrophy type 1 (DM1) in Taiwan, DM-suspected patients and their families identified during the period of 1990-2001 had their clinical records reevaluated and the CTG repeat sizes at the DM1 locus examined. A total of 96 subjects belonging to 26 families were identified as DM1 patients, which gave a minimal disease prevalence of 0.46/100,000 inhabitants. Clinical anticipation was frequently observed in affected families, even in some parent-child pairs with transmission contraction of the CTG repeat size. The inverse correlation between age at onset and CTG repeat length was significant only in patients with small expansions. In addition, a DM1 carrier with a childhood-onset son was found to have CTG length heterogeneity in the range of 40-50, indicating that premutation alleles could be unstable during gametogenesis as well as in somatic tissues. Our data demonstrated that DM1 is a rare disease in Taiwan and showed that transmission contraction of repeat size is more likely to occur in alleles with large repeats.

Electron- or hole-assisted reactions of H defects in hydrogen-bonded KDP

We present an ab initio study of the stability and defect reactions of neutral and charged H interstitial (H(i)) and H vacancy (H(v)) in KH2PO4 (KDP). We find that while there is no interaction between the neutral H(i) and the host, the addition of an electron leads to the ejection of a H host atom and the subsequent formation of an interstitial H2 molecule and a H(v). In sharp contrast, the addition of a hole results in the formation of a hydroxyl bond. Thus, H(i) in both charged states severs the H-bonded network. For the H(v), the addition of a hole leads to the formation of a peroxyl bridge. The neutral H(i) and the positively charged H(v) induce states in the gap. The results elucidate the underlying atomic mechanism for the defect reactions suggested by experiment.

[Study on the interaction between sparfloxacin and serum albumins by fluorescence]

The binding reaction between sparfloxacion (SPFX) and bovine serum albumin (BSA) or chicken egg albumin (CEA) in aqueous was studied using fluorescence and absorption spectra. Their binding constants are KCEA = 8.29 x 10(6) and KBSA = 4.41 x 10(7), and the binding sites are nCEA = 0.558, nBSA = 0.793 respectively. The action distances (RCEA = 1.99 nm, RBSA = 2.09 nm) and energy transfer efficiencies (ECEA = 0.766, EBSA = 0.714) between donor-acceptor and SPFX were obtained by Förster's nonradiative energy transfer mechanism. The experiment demonstrated that the higher the temperature is, the lower the slopes of quenching curves of BSA and CEA are in presence of different amounts of SPFX. It is confirmed that the combination for SPFX with BSA or CEA is a single static quenching process, their interaction may be interpreted with energy transfer mechanism. Through binding reaction of the two albumins with SPFX, the biological effects and action mechanism of SPFX with albumins in vivo were discussed.

Corneal decompensation and graft failure secondary to a broken posterior chamber poly(methyl methacrylate) intraocular lens haptic

A 66-year-old man developed an unexplained corneal decompensation 7 years after extracapsular cataract extraction and implantation of a single-piece poly(methyl methacrylate) (PMMA) posterior chamber intraocular lens (IOL). He had penetrating keratoplasty (PKP). Two years later, he developed corneal graft failure secondary to an IOL haptic fragment in the anterior chamber angle. The patient had a repeat corneal graft and IOL exchange. The broken haptic was examined with scanning electron microscopy. The findings were consistent with late fracture of the haptic within the capsular bag, which was presumably weakened by an improper implantation technique. Fracture of a PMMA haptic should be suspected as a cause of corneal decompensation and corneal graft failure after cataract surgery. This case emphasizes the importance of safe implantation techniques.

Functional magnetic resonance imaging of the visual system

Functional magnetic resonance imaging (fMRI), which is a technique useful for non-invasive mapping of brain function, is well suited for studying the visual system. This review highlights current clinical applications and research studies involving patients with visual deficits. Relevant reports regarding the investigation of the brain's role in visual processing and some newer fMRI techniques are also reviewed. Functional magnetic resonance imaging has been used for presurgical mapping of visual cortex in patients with brain lesions and for studying patients with amblyopia, optic neuritis, and residual vision in homonymous hemianopia. Retinotopic borders, motion processing, and visual attention have been the topics of several fMRI studies. These reports suggest that fMRI can be useful in clinical and research studies in patients with visual deficits.

[Study on high-efficiency gene transfer of pseudotyped HIV vector]

OBJECTIVE

To investigate the high-efficiency of pseudotyped HIV as gene transfer vector.

METHODS

Three plasmids of pseudotyped HIV gene transfer vector system were transferred into packaging cell line 293T by Ca3 (PO4)2 precipitation method. GFP (Green Fluorescence Protein) or HSV-tk gene was constructed in the plasmid pHR'CS respectively (pHR'CS.GFP or pHR'CS.HSV-tk). The pseudotyped HIV particles were observed through electronic microscopy and were measured through spectrofluorophotometer. High titer pseudotyped HIV was harvested from volume of virus-producing cell supernatant and concentrated. Ovarian epithelial cancer cell line SKOV3 and normal human gingival fibroblast cell GF were infected by pseudotyped HIV. PCR and RT-PCR were resorted to demonstrate the successful transduction and transcription of the HSV-tk gene. After administration of GCV, the changes of those cells and apoptosis were observed through optical microscopy. The cytotoxicity efficacy of HSV-tk/GCV system was evaluated by MTT method. The growth inhibition rate (GIR) of cells and inhibition concentration 50 (IC50) were counted.

RESULTS

The above plasmids were effectively transferred into 293T cell. A lot of pseudotyped HIV particles were observed through electronic microscopy. The virus supernatant had a high absorbing value at 510 nm through spectrofluorophotometer, which proved the existence of virus. After pseudotyped HIV infection, SKOV3 and GF had remarkable infection rate. 600 bp strand was seen through PCR and RT-PCR. Changes and apoptosis of cells followed by administration of GCV were observed. The MTT method showed that the cytotoxicity efficacy of GCV was high to SKOV3 and GF cell.

CONCLUSIONS

The pseudotyped HIV is a high-efficiency gene transfer vector.

Effect of genotoxic exposure to chromium among electroplating workers in Taiwan

The objective of this study was to investigate the association between chromium (Cr) concentrations and sister chromatid exchanges (SCE) formation in Cr workers and to assess the effects of susceptible genes (glutathione S-transferase M1 and T1) on the frequency of deletion and SCE/cell. Urinary Cr concentration was significantly elevated in Cr workers (3.67 +/- 3.89 microg/g creatinine) compared to control group (1.21 +/- 1.16 microg/g creatinine, P < 0.01). There was also a significant difference of superoxide dismutase (SOD) levels between Cr workers (6.86 +/- 0.80 U/mg Hb) and controls (7.16 +/- 0.53 U/mg Hb, P < 0.01). The frequencies of SCE and high frequency cells (HFC) were significantly correlated with smoking habits and with duration of exposure to Cr. A significantly higher percentage (50%) of Cr workers had both the null GSTM1 and GSTT1 genotype as compared to 10% of the controls (P < 0.01). However, the chromosomal DNA damage effect of GSTM1 and GSTT1 genotypes, individually or in combination, was not revealed in Cr exposed workers.

Distribution of enantiomers of trans-tramadol and trans-O-demethyltramadol in central nervous system of rats

AIM

To investigate the distribution of the enantiomers of trans-tramadol (trans-T) and its active metabolite, trans-O-demethyltramadol (M1), in the central nervous system (CNS).

METHODS

After a single ip dose of trans-T hydrochloride or M1, the rats were killed by decapitation. A high performance capillary electrophoresis (HPCE) method was used to determine the concentrations of enantiomers of trans-T and M1 in the serum and different brain tissues, including cerebrospinal fluid (CF), cerebral cortex (CC), corpus striatum (CS), hypothalamus (HY), cerebellum (CE), and medulla oblongata (MO).

RESULTS

After ip trans-T hydrochloride, the concentrations of (+)-trans-T were higher than those of (-)-trans-T in the serum and all tested brain tissues; The concentrations of (+)-M1 were lower than those of (-)-M1 in the all tested brain tissues; The concentrations of the enantiomers of trans-T and M1 were the highest in the CC, the lowest in the CF. After ip M1, the concentrations of (+)-M1 were higher than those of (-)-M1 in the serum and all tested brain tissues; The concentrations of the enantiomers of M1 were the highest in the CC, the lowest in the CF.

CONCLUSION

The concentrations of the enantiomers of trans-T and M1 varied in the serum and different brain tissues. The distribution of trans-T and M1 in the CNS of rats was stereoselective. The stereoselectivity in the distribution of M1 after M1 injection was different with that after trans-T injection.

Functional magnetic resonance imaging of eye dominance at 4 tesla

We studied eye dominance in visual cortex and lateral geniculate nucleus (LGN) using functional magnetic resonance imaging (fMRI) at a very high magnetic field (4 tesla). Eight normal volunteers were studied with fMRI at 4 tesla during alternating monocular visual stimulation. The acquisition was repeated twice in 4 subjects to confirm reproducibility. In addition, magnetic resonance signal intensities during three conditions (right eye stimulation, left eye stimulation, and control condition) were compared to determine whether the observed area was truly or relatively monocular in 2 subjects. In both the individual and group analyses, the anterior striate cortex was consistently activated by the contralateral eye more than the ipsilateral eye. Additionally, we found evidence that there were areas in the bilateral LGN which were more active during the stimulation of the contralateral eye than during the stimulation of the ipsilateral eye. The activated areas were reproducible, and the mean ratio of the overlapping area was 0.71 for the repeated scans. The additional experiment revealed that the area in the anterior visual cortex could be divided into two parts, one truly monocular and the other relatively monocular. Our finding confirmed previous fMRI results at 1.5 tesla showing that eye dominance was observed in the contralateral anterior visual cortex. However, the eye dominance in the visual cortex was found not only in the most anterior area corresponding to the monocular temporal crescent but also in the more posterior area, presumably showing the greater sensitivity of the temporal visual field (nasal retina) as compared with the nasal visual field (temporal retina) in the peripheral visual field (peripheral retina). In addition, it is suggested that the nasotemporal asymmetry of the retina and the visual fields is represented in the LGN as well as in the visual cortex.

Hepatic Schistosomiasis japonica in a patient with gallstones and bile duct stones--a case report

Schistosomiasis, a common parasitic disease in many countries, is found as imported cases in Taiwan. Responsible for human infections are five species, one of which, Schistosoma japonicum, is currently endemic in China and South-east Asia. Chronic infection with S. japonicum may lead to the development of liver fibrosis, calcification and portal hypertension. Under investigation by sonography and computed tomography (CT) scan, a peculiar "turtle-back" appearance of liver fibrosis and calcification may be found. Herein, we report a case referred to our department due to jaundice. The sonography of liver showed typical "turtle-back" appearance. Gallstones and bile duct stones were also found in this case. Surgical interventions with percutaneous transhepatic biliary drainage (PTBD), cholecystectomy and choledocholithotomy were performed to relieve the obstructive jaundice and remove the stones. There were no parasitic eggs in the extracted stones or in drained bile juice. However, deposits of calcified S. japonicum eggs in liver parenchyma and portal tracts were identified in liver biopsy. No special treatment was given for the schistosomiasis japonica because the calcified parasitic eggs were the sequelae of past infection.

Hypospadias repair using a double onlay preputial flap

From an anatomical view, a more reasonable blood supply can be achieved in hypospadias repair using a double-faced onlay flap. A urethroplasty was performed in 15 patients with middle or posterior hypospadias using a double-faced onlay preputial flap (DOPF). In this method, the urethral plate is preserved and a double-faced preputial flap is developed. The inner face of the flap is sutured to the urethral plate to create the neourethra and the outer face together with the rest of the dorsal prepuce is used for ventral skin coverage. Postoperative complications occurred in 2 patients: 1 developed a fistula in the subcoronal region and 1 had dorsal skin necrosis and suture disruption of the glanular wings. The overall complication rate was 13%. The DOPF provides a well-vascularized ventral skin cover and reduces the area of avascular dorsal skin. The viability of the neourethra can be evaluated by simply looking at the outer face of the flap. However, the complication rate is similar to that of other techniques.