Structural insights reveal interplay between LAG-3 homodimerization, ligand binding, and function

Lymphocyte activation gene-3 (LAG-3) is an inhibitory receptor expressed on activated T cells and an emerging immunotherapy target. Domain 1 (D1) of LAG-3, which has been purported to directly interact with major histocompatibility complex class II (MHCII) and fibrinogen-like protein 1 (FGL1), has been the major focus for the development of therapeutic antibodies that inhibit LAG-3 receptor-ligand interactions and restore T cell function. Here, we present a high-resolution structure of glycosylated mouse LAG-3 ectodomain, identifying that cis-homodimerization, mediated through a network of hydrophobic residues within domain 2 (D2), is critically required for LAG-3 function. Additionally, we found a previously unidentified key protein-glycan interaction in the dimer interface that affects the spatial orientation of the neighboring D1 domain. Mutation of LAG-3 D2 residues reduced dimer formation, dramatically abolished LAG-3 binding to both MHCII and FGL1 ligands, and consequentially inhibited the role of LAG-3 in suppressing T cell responses. Intriguingly, we showed that antibodies directed against D1, D2, and D3 domains are all capable of blocking LAG-3 dimer formation and MHCII and FGL-1 ligand binding, suggesting a potential allosteric model of LAG-3 function tightly regulated by dimerization. Furthermore, our work reveals unique epitopes, in addition to D1, that can be targeted for immunotherapy of cancer and other human diseases.

Recent progress of exciton transport in two-dimensional semiconductors

Spatial manipulation of excitonic quasiparticles, such as neutral excitons, charged excitons, and interlayer excitons, in two-dimensional semiconductors offers unique capabilities for a broad range of optoelectronic applications, encompassing photovoltaics, exciton-integrated circuits, and quantum light-emitting systems. Nonetheless, their practical implementation is significantly restricted by the absence of electrical controllability for neutral excitons, short lifetime of charged excitons, and low exciton funneling efficiency at room temperature, which remain a challenge in exciton transport. In this comprehensive review, we present the latest advancements in controlling exciton currents by harnessing the advanced techniques and the unique properties of various excitonic quasiparticles. We primarily focus on four distinct control parameters inducing the exciton current: electric fields, strain gradients, surface plasmon polaritons, and photonic cavities. For each approach, the underlying principles are introduced in conjunction with its progression through recent studies, gradually expanding their accessibility, efficiency, and functionality. Finally, we outline the prevailing challenges to fully harness the potential of excitonic quasiparticles and implement practical exciton-based optoelectronic devices.

Comparison of Early Outcomes of Stereotactic Accelerated Partial Breast Irradiation vs. Volumetric Modulated Arc Therapy-Based FAST-FORWARD Whole Breast Irradiation for Breast Cancer

PURPOSE/OBJECTIVE(S)

Despite evidence supporting APBI from 8 published prospective randomized trials enrolling over 10,000 women, the uptake of APBI in clinical practice is surprisingly low. This is being exacerbated by a new, convenient, and safe shortened WBI schedule. Here, we report the dosimetric and early outcome analyses of the first >1000 patients treated at our institution since the first adoption of stereotactic APBI and the ultra-hypofractionated WBI regimen.

MATERIALS/METHODS

From 2016 to 2022, 801 women with breast cancers in the suitable or cautionary categories according to the ASTRO APBI consensus panel guidelines, received 30 Gy in 5 fractions (92%) either using a robotic stereotactic radiation system (83%) or stereotactic volumetric-based arc therapy (VMAT, 17%). Between 2020 and 2022, 468 women, who were not candidates for APBI and not undergoing any regional irradiation received 26 Gy in 5 fractions using VMAT to the whole breast with the addition of cardiac sparing technique in left-sided breast cancer patients. Tumor bed boosts were delivered in 99% of FF-WBI patients. We evaluated dose-volume histogram parameters for target volumes and organs-at-risk and radiation-related toxicities during RT or within 6 months after the end of RT.

RESULTS

Target volume coverage was acceptable in both groups, with mean 96% of the target volumes receiving 95% of the prescribed doses and 0 cm3 within target volumes exceeding 105% of the prescribed doses. S-APBI resulted in small, but statistically significant, reductions in the radiation dose delivered to the ipsilateral breast, contralateral breast, lungs, heart, and coronary artery compared with FF-WBI. Comparing WBI to APBI, the mean contralateral breast dose, ipsilateral lung V20 Gy, mean contralateral lung dose, and mean heart dose, were reduced by 89%, 78%, 73%, and 29%, respectively. With median follow-up periods of 32 months for s-APBI and 19 months for FF-WBI, acute toxicity was assessable in all patients. The risks of any grade acute toxicity were 21% for s-APBI and 25% for FF-WBI (p = .117). Among them, grade 2 rates were 1.3% in both groups and no severe toxicity has been reported.

CONCLUSION

We found s-APBI and VMAT-based FF WBI were associated with favorable dosimetric and acute toxicity profiles. However, considering significantly less irradiated volume in the breast, lungs, and heart, APBI with advanced available technique options should be considered over any WBI-based approach for patients at low risk for local recurrence.

Patterns and Longitudinal Changes in The Practice of Breast Cancer Radiotherapy in Korea: Korean Radiation Oncology Group 22-01

PURPOSE/OBJECTIVE(S)

To analyze contemporary practice patterns in breast cancer radiotherapy (RT) and to assess longitudinal changes therein over 5 years in Korea.

MATERIALS/METHODS

A nationwide survey was conducted among board-certified radiation oncologists in Korea by the Division for Breast Cancer of the Korean Radiation Oncology Group in March 2022. The survey consisted of 44 questions related to six domains: hypofractionated (HypoFx) whole breast RT, accelerated partial breast RT (APBI), regional nodal irradiation (RNI), RT for ductal carcinoma in situ (DCIS), postmastectomy RT (PMRT), and tumor bed boost.

RESULTS

In total, 70 radiation oncologists from 61 of 101 (60%) institutions participated in the survey. HypoFx RT was used by 62 respondents (89%), which has significantly increased from 36% in 2017. The HypoFx RT was commonly administered at 40-42.5 Gy in 15-16 fractions. APBI was used by 12 respondents (17%), which has increased from 5% in 2017. The use of RNI did not change significantly: ≥ pN2 (6%), ≥ pN1 (33%), and ≥ pN1 with pathological risk factors (61%). However, the indications for use of internal mammary lymph node (IMN) irradiation have expanded. In particular, the rates of routine treatment of IMN (11% from 6% in 2017) and treatment in cases of ≥ pN2 (27% from 14% in 2017) have doubled; however, the rate of treatment for only IMN involvement, identified on imaging, has decreased to 31% from 47% in 2017. With regard to DCIS, the use of hypoFx RT increased to 75% from 25%, and the rate of omission on of RT after breast-conserving surgery decreased to 38% from 48% in 2017. The use of hypoFx RT for PMRT also increased to 36% from 8% in 2017.

CONCLUSION

The adoption of HypoFx RT after breast-conserving surgery in invasive breast cancer and DCIS has increased significantly, whereas that for PMRT has increased moderately, compared to 2017. Further studies are required to determine the optimal use of RNI.

Direct 3D-printed CdSe quantum dots via scanning micropipette

The micropipette, pencil-shaped with an aperture diameter of a few micrometers, is a potentially promising tool for the three-dimensional (3D) printing of individual microstructures based on its capability to deliver low volumes of nanomaterial solution on a desired spot resulting in micro/nanoscale patterning. Here, we demonstrate a direct 3D printing technique in which a micropipette with a cadmium selenide (CdSe) quantum dot (QD) solution is guided by an atomic force microscope with no electric field and no piezo-pumping schemes. We define the printed CdSe QD wires, which are a composite material with a QD-liquid coexistence phase, by using photoluminescence and Raman spectroscopy to analyze their intrinsic properties and additionally demonstrate a means of directional falling.

Ulnar positive variance associated with TFCC foveal tear

OBJECTIVE

The ulnar positive variance (UPV) can be observed on simple radiography due to a triangular fibrocartilage complex (TFCC) foveal tear. This study investigated to identify how much radiographic UPV occurs due to a TFCC foveal tear, which may be misdiagnosed as an ulnar impaction syndrome (UIS).

MATERIALS AND METHODS

One hundred forty patients who underwent arthroscopic transosseus TFCC foveal repair from March 2013 to March 2019 in our institution were enrolled in this study. Ulnar variances were measured in preoperative, postoperative 6 weeks, 1-year follow-up wrist posteroanterior (PA) radiograph, and power grip PA radiograph of the affected wrist and were compared with those of the same patient's unaffected wrist.

RESULTS

In the neutral wrist PA radiograph, ulnar variance increased by 0.56 mm (p < 0.001) after TFCC foveal tear compared to the unaffected side. In the power grip view, ulnar variance also increased by 0.39 mm (p < 0.001) in the affected wrist. The preoperative ulnar positive variance was reduced after an arthroscopic transosseous TFCC foveal repair from 0.56 to 0 mm (p < 0.001). No significant statistical difference was observed between an Atzei class 2 and 3 TFCC tear (0.56 mm vs. 0.41 mm, p = 0.263).

CONCLUSION

This study revealed that TFCC foveal tear induces 0.56 mm of radiologic UPV, which was successfully corrected after arthroscopic transosseous TFCC foveal repair. Therefore, UPV associated with TFCC foveal tear should not be misdiagnosed as an UIS. Also, when ulnar shortening osteotomy is planned in case of UIS combined with TFCC foveal tear, the amount of UPV induced by TFCC foveal tear should be considered to prevent over-shortening.

Safety and Efficacy of Stent-Assisted Coiling of Unruptured Intracranial Aneurysms Using Low-Profile Stents in Small Parent Arteries

BACKGROUND AND PURPOSE

Stent-assisted coiling of intracranial aneurysms arising from small vessels (≤ 2.0 mm) is a common procedure. However, data regarding its treatment outcomes are scarce. This study evaluated the clinical and radiologic outcomes of stent-assisted coiling using low-profile stents for aneurysms of small parent arteries.

MATERIALS AND METHODS

From November 2015 to October 2020, sixty-four patients with 66 aneurysms arising from parent arteries of ≤2.0 mm were treated with stent-assisted coiling using a Low-Profile Visualized Intraluminal Support Junior (LVIS Jr) or the Neuroform Atlas stent in a single institution. The clinical and radiologic data were retrospectively reviewed, and the risk factors for procedure-related complications were evaluated.

RESULTS

The LVIS Jr and Neuroform Atlas stents were used in 22 (33.3%) and 44 (66.7%) cases, respectively. Technical success was achieved in 66 cases (100%). Immediate postprocedural aneurysm occlusion grades assessed by the Raymond-Roy occlusion classification were I (57.6%), II (19.7%), and III (22.7%), respectively. Procedure-related complications occurred in 10 cases (15.2%), with 8 thromboembolic complications (12.1%) and 2 hemorrhagic complications (3.0%). Procedure-related morbidity was 4.5% without mortality. On multivariate analysis, current smoking (odds ratio = 7.1, P = .021) had a statistically significant effect on procedure-related complications.

CONCLUSIONS

Stent-assisted coiling of intracranial aneurysms with low-profile stents in small vessels (≤ 2.0 mm) had a 100% success rate and a 15.2% overall complication rate with 4.5% morbidity. Current smoking was a significant risk factor associated with procedure-related complications.

Efficacy and Safety of Flow-Diverter Therapy for Recurrent Aneurysms after Stent-Assisted Coiling

BACKGROUND AND PURPOSE

Flow-diverter treatment for previously stented aneurysms has been reported to be less effective and prone to complications. In this study, we evaluated the effectiveness and safety of flow diverters for recurrent aneurysms after stent-assisted coiling.

MATERIALS AND METHODS

Patients who underwent flow-diverter placement for recurrent aneurysms after stent-assisted coiling between March 2015 and March 2019 were recruited. Clinical and radiographic characteristics and clinical and angiographic outcomes were retrospectively evaluated.

RESULTS

Among 133 patients who underwent flow-diverter insertion, 17 (male/female ratio = 5:12; mean age, 53.8 years) were treated for recurrent aneurysms after stent placement with (n = 16) or without (n = 1) coiling. Eight patients initially presented with subarachnoid hemorrhage; 7, with headache; and 2, with visual field defects. Angiographic morphology included large/giant saccular in 12 patients, dissecting in 2, fusiform in 1, traumatic pseudoaneurysm in 1, and ruptured blood blister-like aneurysm in 1. The duration between the first treatment and flow-diverter placement ranged from 2 weeks to 15 months (median, 6 months). Flow-diverter placement was successful in all cases without any complications. All patients had favorable outcomes (mRS, 0-2), without any newly appearing symptoms. Aneurysms were followed up with conventional angiography at least once in 6-18 months. Sixteen aneurysms showed complete occlusion, and 1 aneurysm was enlarged.

CONCLUSIONS

Results from this case series investigating flow-diverter placement for recurrent aneurysms after stent-assisted coiling suggested that the procedure is safe and effective. Further study in a larger population may be warranted.

Abstract P3-12-12: Impact of regional nodal irradiation for breast cancer patients with supraclavicular and/or internal mammary lymph node involvement: A multicenter, retrospective study (KROG 16-14)

Purpose: To evaluate the treatment outcomes of radiotherapy (RT) for breast cancer with ipsilateral supraclavicular (SCL) and/or internal mammary (IMN) lymph node involvement.

Methods: A total of 353 patients from 11 institutions were included. One hundred and thirty-six patients had SCL involvement, 148 had IMN involvement, and 69 had both. All patients received neoadjvant systemic therapy followed by breast conserving surgery or mastectomy, and postoperative RT to whole breast/chest wall. As for regional lymph node irradiation, SCL RT was given to 344 patients, and IMN RT to 236 patients. The median RT dose was 50.4 Gy.

Results: The median follow-up duration was 61 months (range, 7-173). In-field progression was present in SCL (n=20) and/or IMN (n=7). The 5-year disease-free survival (DFS) and overall survival rates were 57.8% and 75.1%, respectively. On multivariate analysis, both SCL/IMN involvement, number of axillary lymph node ≥4, triple negative subtype, and mastectomy were significant adverse prognosticators for DFS (p = 0.022, 0.001, 0.001, and 0.004, respectively). Regarding the impact of regional nodal irradiation, SCL RT dose ≥54 Gy was not associated with DFS (5-yr rate, 52.9% vs. 50.9%, p = 0.696) in SCL-involved patients, and the receipt of IMN RT was not associated with DFS (5-yr rate, 56.1% vs. 78.1%, p = 0.099) in IMN-involved patients.

Conclusion: Neoadjuvant chemotherapy followed by surgery and postoperative RT achieved an acceptable in-field regional control rate in patients with SCL and/or IMN involvement. However, a higher RT dose to SCL or IMN RT was not associated with the improved DFS in these patients.

Citation Format: Kim K, Jeong Y, Shin KH, Kim JH, Ahn SD, Kim SS, Suh C-O, Kim YB, Choi DH, Park W, Cha J, Chun M, Lee DS, Lee SY, Kim JH, Park HJ. Impact of regional nodal irradiation for breast cancer patients with supraclavicular and/or internal mammary lymph node involvement: A multicenter, retrospective study (KROG 16-14) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-12-12.

Reuse of Living-Donor Liver Graft in Second Recipient with Long-Term Survival

Brain death is a rare situation after living-donor liver transplantation. However, the recipient who suffers from brain death and has functional liver graft is a potential liver donor. We report the 1st case of successful reuse of extended right living-donor liver graft after brain death of the first recipient. The first recipient, who had acute liver failure caused by hepatitis A virus, experienced brain death on the 2nd day after the transplantation. The allograft had a favorable regeneration and functional recovery. On the 7th day, the allograft was procured with a patent hepatic artery, bile duct, portal vein, and reconstructed outflow (right hepatic vein and middle hepatic vein) and successfully implanted into the second recipient. The second recipient has experienced a long-term survival without any complications.

Clinical Implication of Tests for Prostate-specific Antigen in Brain-dead Organ Donors

BACKGROUND

Although cancer screening tests are not mentioned under brain-dead organ donor care guidelines in Korea, we assessed the level of prostate-specific antigen (PSA), an important prostate cancer marker, and performed prostate biopsies when needed in brain-dead organ donors. We believe that insisting on a screening test for cancer diagnosis in donors' organs is important.

MATERIALS AND METHODS

Data were collected between January 2010 and July 2015 from Ajou University Hospital. We retrospectively analyzed the PSA levels and prostate biopsy results in 111 male brain-dead organ donors (mean age, 48.4 years).

RESULTS

The mean PSA level was 7.395 ng/mL (range, 0.062 to 61.780; reference, 0 to 4 ng/mL). Ultrasonography or computed tomographic examination did not reveal prostate cancer, and a rectal examination was not performed. After checking the PSA levels, prostate biopsies were performed in 16 patients based on the recommendations of a urologist, and 4 patients (3.6% of 111) were diagnosed with prostate cancer. All cancers involved adenocarcinomas (acinar type) histopathologically. In 2 patients, the Gleason score was 6 (3 + 3), whereas the other 2 showed a score of 7 (3 + 4). Among the patients diagnosed with prostate cancer, 1 donated his liver and corneas, and the remaining 3 could not donate.

CONCLUSION

Well-defined cancer screening tests are needed in Korea. Additionally, when the probability of organ transplantation-induced cancer metastasis is low or a recipient is at a high risk owing to not receiving organs, the law should allow organ donation even if prostate cancer is diagnosed in the donor.

Interregional correlations of glucose metabolism between the basal ganglia and different cortical areas: an ultra-high resolution PET/MRI fusion study using 18F-FDG

Basal ganglia have complex functional connections with the cerebral cortex and are involved in motor control, executive functions of the forebrain, such as the planning of movement, and cognitive behaviors based on their connections. The aim of this study was to provide detailed functional correlation patterns between the basal ganglia and cerebral cortex by conducting an interregional correlation analysis of the ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET) data based on precise structural information. Fifteen participants were scanned with 7-Tesla magnetic resonance imaging (MRI) and high resolution research tomography (HRRT)-PET fusion system using ¹⁸F-FDG. For detailed interregional correlation analysis, 24 subregions of the basal ganglia including pre-commissural dorsal caudate, post-commissural caudate, pre-commissural dorsal putamen, post-commissural putamen, internal globus pallidus, and external globus pallidus and 80 cerebral regions were selected as regions of interest on the MRI image and their glucose metabolism were calculated from the PET images. Pearson's product-moment correlation analysis was conducted for the interregional correlation analysis of the basal ganglia. Functional correlation patterns between the basal ganglia and cerebral cortex were not only consistent with the findings of previous studies, but also showed new functional correlation between the dorsal striatum (i.e., caudate nucleus and putamen) and insula. In this study, we established the detailed basal ganglia subregional functional correlation patterns using ¹⁸F-FDG PET/MRI fusion imaging. Our methods and results could potentially be an important resource for investigating basal ganglia dysfunction as well as for conducting functional studies in the context of movement and psychiatric disorders.

Immune-camouflaged graphene oxide nanosheets for negative regulation of phagocytosis by macrophages

Signal regulatory protein alpha (SIRPα) is highly expressed in macrophages of the reticuloendothelial system and in tumor-associated macrophages, whereas tumor cells express the surface membrane protein, CD47, which interacts with SIRPα to negatively regulate phagocytosis. In this study, we modified the surfaces of graphene oxide (GO) nanosheets with a CD47-like SIRPα-binding peptide (SP). The presence of SP on GO nanosheets reduced the macrophage uptake to a greater extent than the PEGylation of such nanosheets. This reduced uptake was found to be mediated by the activation of Src homology region 2 domain-containing phosphatase 1 (SHP-1) and the downstream inhibition of myosin assembly, which is necessary for phagosome formation. Unlike SP-coated GO nanosheets, PEGylated GO nanosheets did not affect myosin assembly or phagocytosis. After in vivo systemic administration, the clearance of SP-coated GO nanosheets was slower than that of PEGylated GO nanosheets, and this difference increased with repeated administration. Finally, SP-coated GO nanosheets showed a higher distribution to tumor tissues than PEGylated GO nanosheets or a physical mixture of SP and GO nanosheets. Our findings indicate that immune-camouflaged GO nanosheets with natural CD47-like SIRPα-binding molecules can reduce the nonspecific loss of such nanosheets through macrophage uptake, thereby enhancing their blood circulation and tumor delivery after multiple injections.

Imaging of regional air distributions in porcine lungs using high-performance electrical impedance tomography system

Electrical impedance tomography (EIT) allows functional imaging of regional lung ventilation for real-time bedside monitoring of mechanically ventilated patients. Images showing time-changes of regional air distributions in the lungs can provide valuable diagnostic information for lung protective mechanical ventilation. This paper reports in vivo porcine imaging experiments of regional lung ventilation using a 16-channel parallel EIT system. Real-time time-difference chest images of 10 animals were reconstructed during mechanical ventilations with a temporal resolution of 50 frame/s. Analyzing the images together with the airway volume-pressure information from the mechanical ventilator, we could successfully produce regional compliance images at PEEP (positive end expiratory pressure) titration. From in vivo animal experiments, we propose the method as a continuous monitoring means for LPV (lung protective ventilation).

Tumor-related leukocytosis is associated with poor radiation response and clinical outcome in uterine cervical cancer patients

BACKGROUND

To evaluate response to radiation and clinical outcome of uterine cervical cancer patients with tumor-related leukocytosis (TRL) at initial diagnosis and during definitive radiotherapy.

PATIENTS AND METHODS

We retrospectively analyzed 2456 patients with stage IA-IVA uterine cervical cancer who received definitive radiotherapy with (37.4%) or without (62.6%) platinum-based chemotherapy between 1986 and 2012. TRL was defined as two or more occurrences of leukocytosis over 9000/μl at the time of diagnosis and during the course of treatment. Locoregional failure-free survival (LFFS) and overall survival (OS) were compared between patients with or without TRL.

RESULTS

The median age of all patients was 55 years, and the median follow-up time was 65.1 months. TRL was observed in 398 patients (16%) at initial diagnosis; TRL (+) patients were younger and had larger tumors, advanced stage, and more frequent lymph node metastases (all P < 0.05). TRL (+) patients showed a significantly lower rate of complete remission than TRL (-) patients (89.9% versus 96.3%, respectively, P = 0.042). Ten-year LFFS and OS for all patients were 84% and 78%, respectively. LFFS and OS were significantly lower in TRL (+) patients than TRL (-) patients (10-year LFFS: 69% versus 87% respectively, P < 0.001; 10-year OS: 63% versus 81% respectively P < 0.001). After propensity score matching, LFFS and OS rates in TRL (+) patients remained significantly lower than for TRL (-) patients; this significant difference was also observed on multivariate analysis. Twenty-six percent of patients with locoregional failure (n = 345) were TRL (+) and had significantly poorer median OS (6 versus 12 months, P = 0.001).

CONCLUSION

This study reveals the aggressive nature of cervical cancer with TRL and its poor response to radiation therapy. Given the unfavorable prognosis and higher probability of treatment failure, optimal diagnostic and therapeutic approaches and careful monitoring for early detection of recurrence should be considered for these patients.

Distribution of Porcine Endogenous Retrovirus in Different Organs of the Hybrid of a Landrace and a Jeju Domestic Pig in Korea

Xenotransplantation offers a solution to the shortage of available organs for transplantation, and the pig represents an ideal source of such organs. However, porcine endogenous retrovirus (PERV), whose genome is integrated in pigs, has been suggested to pose a potential risk of xenotransmission. Expression of PERVs in different organs of pigs was carefully measured at DNA, mRNA, and protein levels, providing information valuable for the application of pig organs in xenotransplantation. An analysis of PERV DNA showed that a very similar number of PERV copies was present in the genome of all organs, whereas mRNA and protein levels of PERV varied depending on the organ, with kidney, liver, and spleen expressing high levels of both mRNA and protein. In contrast, mRNA and protein levels were dissimilar in the lung and brain, where mRNA levels were low but protein levels were high. This discrepancy indicates that mRNA levels are not always reflected in protein expression. In addition, the difference between mRNA and protein highlights the importance of choosing the proper analysis method for diagnosing viral infection. In summary, this study provides insight into the distribution of PERV in various organs at the DNA, mRNA, and protein levels, and also informs the proper selection of tissues or organs for future clinical xenotransplantation.

Decontamination method using heat and relative humidity for radish seeds achieves a 7-log reduction of Escherichia coli O157:H7 without affecting product quality

We developed a novel decontamination method to inactivate Escherichia coli O157:H7 on radish seeds without adversely affecting seed germination or product quality. The use of heat (55, 60, and 65 °C) combined with relative humidity (RH; 25, 45, 65, 85, and 100%) for 24h was evaluated for effective microbial reduction and preservation of seed germination rates. A significant two-way interaction of heat and RH was observed for both microbial reduction and germination rate (P<0.0001). Increases in heat and RH were associated with corresponding reductions in E. coli O157:H7 and in germination rate (P<0.05). The order of lethality for the different treatments was generally as follows: no treatment <55 °C/25-65% RH ≒60 °C/25-45% RH ≒65 °C/25% RH <55 °C/85% RH =60 °C/65% RH <55 °C/100% RH =60 °C/85-100% RH =65 °C/45-100% RH. The most effective condition, 65 °C/45% RH, completely inactivated E. coli O157:H7 on the seeds (7.0 log CFU/g reduction) and had no significant effect on the germination rate (85.4%; P>0.05) or product quality. The method uses only heat and relative humidity without chemicals, and is thus applicable as a general decontamination procedure in spout producing plants where the use of growth chambers is the norm.

Short communication: antiviral activity of subcritical water extract of Brassica juncea against influenza virus A/H1N1 in nonfat milk

Subcritical water extract (SWE) of Brassica juncea was studied for antiviral effects against influenza virus A/H1N1 and for the possibility of application as a nonfat milk supplement for use as an "antiviral food." At maximum nontoxic concentrations, SWE had higher antiviral activity against influenza virus A/H1N1 than n-hexane, ethanol, or hot water (80°C) extracts. Addition of 0.5mg/mL of B. juncea SWE to culture medium led to 50.35% cell viability (% antiviral activity) for Madin-Darby canine kidney cells infected with influenza virus A/H1N1. Nonfat milk supplemented with 0.28mg/mL of B. juncea SWE showed 39.62% antiviral activity against influenza virus A/H1N1. Thus, the use of B. juncea SWE as a food supplement might aid in protection from influenza viral infection.

Dopaminergic manipulations and its effects on neurogenesis and motor function in a transgenic mouse model of Huntington's disease

Huntington's disease (HD) is an inherited neurodegenerative disorder that is classically defined by a triad of movement and cognitive and psychiatric abnormalities with a well-established pathology that affects the dopaminergic systems of the brain. This has classically been described in terms of an early loss of dopamine D2 receptors (D2R), although interestingly the treatments most effectively used to treat patients with HD block these same receptors. We therefore sought to examine the dopaminergic system in HD not only in terms of striatal function but also at extrastriatal sites especially the hippocampus, given that transgenic (Tg) mice also exhibit deficits in hippocampal-dependent cognitive tests and a reduction in adult hippocampal neurogenesis. We showed that there was an early reduction of D2R in both the striatum and dentate gyrus (DG) of the hippocampus in the R6/1 transgenic HD mouse ahead of any overt motor signs and before striatal neuronal loss. Despite downregulation of D2Rs in these sites, further reduction of the dopaminergic input to these sites by either medial forebrain bundle lesions or receptor blockade using sulpiride was able to improve both deficits in motor performance and adult hippocampal neurogenesis. In contrast, a reduction in dopaminergic innervation of the neurogenic niches resulted in impaired neurogenesis in healthy WT mice. This study therefore provides evidence that D2R blockade improves hippocampal and striatal deficits in HD mice although the underlying mechanism for this is unclear, and suggests that agents working within this network may have greater effects than previously thought.

Multidetector CT imaging features of solid pseudopapillary tumours of the pancreas in male patients: distinctive imaging features with female patients

OBJECTIVE

To describe multidetector CT imaging features of solid pseudopapillary tumours (SPTs) in male patients and to compare these imaging features with those found in female patients.

METHODS

The institutional review board approved this retrospective study. We included the CT images of 72 patients (M:F = 12:60; mean age, 35.0 years) diagnosed with SPT by histology. CT images were reviewed on the following: location of the tumour, maximal diameter, shape, margin and the fraction of the tumour composition. Statistical differences in CT imaging features were analysed.

RESULTS

Male patients with SPTs were significantly older than female patients (42.4 years vs 33.4 years, p = 0.0408) and the mean size of the SPTs in male patients was larger (6.3 cm vs 4.6 cm, p = 0.0413) than that of SPTs in female patients. Lobulated shape of the SPTs was most frequent in male patients, whereas oval shape was most frequent in female patients (p = 0.0133). SPTs in male patients tended to have a solid component (p = 0.0434). Progressive enhancement in the solid portion of the tumour was seen in 9 (81.8%) of 11 SPTs in male patients and in 30 (79.0%) of 38 SPTs in female patients on multiphasic CT.

CONCLUSION

The imaging features of SPTs in male patients usually appeared as a somewhat large-sized solid mass with a lobulated margin and progressive enhancement. These imaging features may help to differentiate SPTs from other pancreatic tumours for their proper management.

ADVANCES IN KNOWLEDGE

SPTs in male patients appear as somewhat large-sized solid masses with lobulated margins, and this form occurs more frequently in older male patients than in female patients.

Is elective nodal irradiation beneficial in patients with pathologically negative lymph nodes after neoadjuvant chemotherapy and breast-conserving surgery for clinical stage II-III breast cancer? A multicentre retrospective study (KROG 12-05)

BACKGROUND

To evaluate the effects of elective nodal irradiation (ENI) in clinical stage II-III breast cancer patients with pathologically negative lymph nodes (LNs) (ypN0) after neoadjuvant chemotherapy (NAC) followed by breast-conserving surgery (BCS) and radiotherapy (RT).

METHODS

We retrospectively analysed 260 patients with ypN0 who received NAC followed by BCS and RT. Elective nodal irradiation was delivered to 136 (52.3%) patients. The effects of ENI on survival outcomes were evaluated.

RESULTS

After a median follow-up period of 66.2 months (range, 15.6-127.4 months), 26 patients (10.0%) developed disease recurrence. The 5-year locoregional recurrence-free survival and disease-free survival (DFS) for all patients were 95.5% and 90.5%, respectively. Pathologic T classification (0-is vs 1 vs 2-4) and the number of LNs sampled (<13 vs ≥13) were associated with DFS (P=0.0086 and 0.0012, respectively). There was no significant difference in survival outcomes according to ENI. Elective nodal irradiation also did not affect survival outcomes in any of the subgroups according to pathologic T classification or the number of LNs sampled.

CONCLUSIONS

ENI may be omitted in patients with ypN0 breast cancer after NAC and BCS. But until the results of the randomised trials are available, patients should be put on these trials.

Nicastrin overexpression in transgenic mice induces aberrant behavior and APP processing

Nicastrin (NCT) is a component of the presenilin protein complex, which is involved in the cleavage of β-amyloid precursor protein (βAPP) and Notch. The aim of this study was to determine the manner in which overexpression of wild-type human nicastrin (hNCTw) or mutant human nicastrin (hNCTm, D336A/Y337A) regulates brain functions and amyloid precusor protein (APP) processing. For this, we created transgenic (Tg) mice expressing neuron-specific enolase (NSE)-controlled hNCTw or hNCTm and measured their phenotypes as time passed. The NSE/hNCTw and NSE/hNCTm Tg groups exhibited greater behavioral dysfunction from 10 months of age than the non-Tg group, although their severities differed. Further, activity and component levels of the γ-secretase complex were significantly elevated in NSE/hNCTw Tg mice, expect for PEN-2. These alterations induced stimulation of APP processing, resulting in overproduction of Aβ-42 peptide in the NSE/hNCTw Tg group, whereas the NSE/hNCTm Tg group showed a comparatively weaker effect. Furthermore, the highest expression levels of β-secretase and NICD were observed in the NSE/hNCTw Tg group, similar to other phenotypes. Especially, a significances interference on the interaction between NCT and γ-secretase substrates was detected in NSE/hNCTm Tg groups compare with NSE/hNCTw Tg group. These results indicate that hNCTw overexpression in Tg mice promoted active assembly of the γ-secretase complex through modulation of APP processing and behavior, whereas the lesser effect in NSE/hNCTm Tg mice was due to reduced expression of hNCTm. These Tg mice could be useful for the development and application of therapeutic drugs in an animal model of Alzheimer's disease.

Reconstructive endovascular treatment of fusiform or ultrawide-neck circumferential aneurysms with multiple overlapping enterprise stents and coiling

BACKGROUND AND PURPOSE

Fusiform aneurysms and ultrawide-neck circumferential aneurysms are still some of the most challenging lesions. The aim of this study was to investigate the efficacy and feasibility of the use of multiple overlapping Enterprise stents with coiling for the treatment of fusiform or ultrawide-neck circumferential aneurysms.

MATERIALS AND METHODS

Twelve consecutive patients (9 men and 3 women; mean age, 56 years) with fusiform (n = 5) or ultrawide-neck circumferential (n = 7) aneurysms were treated with 2-3 overlapping Enterprise stents and coiling. The feasibility of this procedure and the clinical and angiographic outcomes of this technique were retrospectively evaluated.

RESULTS

All patients were successfully treated by using this technique without any complications. Posttreatment angiographic results revealed grade 4 occlusion of the aneurysm in 6, grade 3 in 4, and grade 2 in 2 patients. Clinical follow-up was performed in all patients (mean, 16 months; range, 5-24 months). Nine patients had an mRS score of 0. Two had an mRS score of 1, one of whom had an initial mRS score of 2 due to the mass effect of a giant aneurysm; the other had a recurrent aneurysm presenting with SAH 5 years after clipping. Angiographic follow-up was performed in 10 patients at 6-20 months posttreatment. Nine had stable or improved occlusion, while 1 had a minor recurrence.

CONCLUSIONS

In this small series, multiple overlapping Enterprise stents with coiling were a feasible and effective option for the treatment of fusiform and ultrawide-neck circumferential aneurysms. Further experience and follow-up are required to document the long-term efficacy of this treatment.

High voltage ultrawide band pulse generator using Blumlein pulse forming line

A high voltage ultrawide band pulse generation system has been developed to radiate intense and ultrawide band electric fields for the examination of effects of the electric fields on the operation of electronic devices. As major components of the system, a helical strip∕wire type of air-cored pulse transformer and a triaxial type of Blumlein pulse forming line have been designed and fabricated to amplify and shape the output pulse, respectively. For the construction of a compact system, the pulse transformer and the Blumlein line are installed in a single cylindrical container. An ultrawide band TEM horn antenna has been fabricated to radiate the Blumlein output pulses to electronic devices. A number of experimental results demonstrate that the system is capable of providing an output pulse whose voltage is greater than 300 kV, pulse duration is ~5 ns, and rise time is ~500 ps with repetition rate of 10 Hz. The peak-to-peak value of electric field intensity of a radiated pulse is also measured to be approximately 42 kV/m at a distance of 10 m away from the antenna.

Reduction of N-tropic mutant porcine endogenous retrovirus infectivity by human tripartite motif-containing 5-isoform alpha

In cases of retroviral infection, the host cell deploys antiviral proteins as a type of innate immunity. Tripartite motif-containing 5-isoform alpha (TRIM5α) is a potent antiviral protein. TRIM5α has been reported to restrict human immunodeficiency virus (HIV) 1 infection in rhesus monkey cells by targeting the incoming viral capsid at the postentry or preintegration stage of the viral life cycle. As a consequence, virus replication and reverse transcription are interrupted. TRIM5α of human origin has also been shown to inhibit N-tropic murine leukemia virus infection. To investigate the inhibitory effect of TRIM5α on porcine endogenous retrovirus (PERV) infection in humans, we constructed a 293T cell line stably expressing human TRIM5α (293T-huTRIM5α) and tested the infectivity of vesicular stomatitis virus glycoprotein envelope pseudotyped viruses (wild-type PERV [wt-PERV], N-tropic mutant PERV, N-tropic murine leukemia virus, and MoMLV). Infectivity of N-tropic mutant PERV was reduced by 43.3% in 293T-huTRIM5α cells, a decrease in efficiency that was more than 3-fold greater than that of wt-PERV in 293T-huTRIM5α cells. Human TRIM5α exhibited inhibitory activity against N-tropic MLV and N-tropic mutant PERV, but showed no antiviral activity against Moloney murine leukemia virus or wt-PERV.

MRI features of serous oligocystic adenoma of the pancreas: differentiation from mucinous cystic neoplasm of the pancreas

OBJECTIVES

The purpose of this study was to describe the MRI features of the benign pancreatic neoplasm serous oligocystic adenoma (SOA) that differ from those of mucinous cystic neoplasm (MCN), a neoplasm with the potential for malignant degeneration.

METHODS

Seven patients with SOA (seven women; mean age 36.6 years) and eight patients with MCN (eight women: mean age 39.9 years) were included. Several imaging features were reviewed: mass size, location, shape, wall thickness, cyst configuration (Type I, unilocular; Type II, multiple clustered cyst; Type III, cyst with internal septation) and signal intensity of the lesion with heterogeneity.

RESULTS

SOA lesions were smaller (3.4 cm) than those of MCN (9.3 cm) (p=0.023). The commonest lesion shape was lobulated (85.7%) for SOA, but oval (50.0%) or lobulated (37.5%) for MCN (p=0.015). The most common cyst configuration was Type II (85.7%) for SOA and Type III (75.0%) for MCN (p=0.008). Heterogeneity of each locule in T(1) weighted images was visible in all cases of MCN, but in no case for SOA (p=0.004).

CONCLUSION

SOA could be differentiated from MCN by identifying the imaging features of lobulated contour with multiple clustered cyst configurations and homogeneity of each locule in T(1) weighted MR images.

Papillary adenocarcinoma arising in a tubular duplication of the jejunum

Alimentary tract duplications are uncommon congenital anomalies containing a normal gastrointestinal mucosa and smooth muscle layer. Intestinal duplication in the jejunum is rare, and any malignancy arising in the jejunal duplication is extremely rare. In this report, we present the first case of papillary adenocarcinoma arising in a tubular duplication of the jejunum. Coronal reformatted images from contrast-enhanced CT revealed a well-enhanced tubular mass in the distal jejunum with small bowel obstruction. There were multiple enlarged lymph nodes in the small bowel mesentery around the superior mesenteric artery. The typical macroscopic and histological findings were present.

Transmissible infection of human 293T cells with porcine endogenous retroviruses subgroup a from NIH-miniature pig

In pig-to-human xenotransplantation, zoonotic infections have been an important barrier. The risk of zoonosis has been emphasized in xenotransplantation after finding that porcine endogenous retroviruses (PERVs) can infect human cells in vitro. Until now, transmissions of PERVs from PK15 cells have been studied in vitro and in vivo, but transmission of PERVs originating from miniature pigs have not been extensively reported. Peripheral blood mononuclear cells from miniature swine showed PERV transmission to human cells. In contrast, specific pathogen-free (SPF) pig islet cells showed no PERV transmission when co-incubated with 293T cells. To evaluate the risk of zoonosis with our experimental mini pigs, we tested the infectivity of PERVs from NIH-miniature pig primary ear cells for human 293T cells. As a result, all subgroups of infectious PERV virion (PERV-A, -B, and -C) were detected in the primary cell culture media. Unlike PERV-C, PERV-A and -B infected human 293T cells. Interestingly, only proviral PERV-A replicated in 293T cells to produce virions after infection. Our results suggested that a prevention study of PERV xenotransmission from experimental miniature pigs should concentrate on PERV-A control.

Preparation of doxorubicin-containing chitosan microspheres for transcatheter arterial chemoembolization of hepatocellular carcinoma

A new form of doxorubicin hydrochloride (DRH)-containing chitosan microspheres (CMs) was prepared by employing an expanding-loading-shrinking (E-L-S) process. One hundred mg of pre-formed CMs were soaked in absolute ethanol and then placed in reduced pressure (the expanding process). Ten mg of DRH (2 mg ml(-1)) were added into the expanded CMs (the loading process). Next the microspheres were freeze-dried (the shrinking process). As a result of this E-L-S process, 10% (w/w) DRH-containing CMs (DRH-CM) were made. During 7 days, 22.6% of the DRH was observed to be released on the in vitro drug release study. In addition, these new DRH-CMs could be used for transcatheter arterial chemoembolization (TACE) procedure in VX2 hepatic tumour models of rabbit and the anti-tumour effects of DRH-CMs were investigated. On the post-CT scan 7 days after the TACE, total infarctions of the VX2 tumour were observed in 5 rabbits among the 6 total rabbits.

The optimum bolus dose of remifentanil to facilitate laryngeal mask airway insertion with a single standard dose of propofol at induction in children

The purpose of this study was to determine the optimal bolus dose of remifentanil required for the successful insertion of the laryngeal mask airway during propofol induction in children without a neuromuscular blocking agent. Twenty-six paediatric patients, aged 3-10 years, requiring anaesthesia for short ambulatory surgery were recruited. A predetermined bolus dose of remifentanil was injected over 30 s, followed by propofol 2.5 mg.kg(-1) over 10 s. The bolus dose of remifentanil was determined by a modified Dixon's up-and-down method, starting from 0.5 microg.kg(-1) (0.1 microg.kg(-1) as a step size). Laryngeal mask insertion was attempted 90 s after the end of remifentanil injection and the response of patients was classified as either 'movement' or 'no movement'. The bolus dose of remifentanil at which there was a 50% probability of successful laryngeal mask insertion (ED(50)) during induction with 2.5 mg.kg(-1) propofol was 0.56 (0.07) microg.kg(-1) in children without a neuromuscular blocking agent. From probit analysis, the ED(50) and ED(95) of remifentanil were 0.52 microg.kg(-1) (95% confidence limits, 0.42-0.62 microg.kg(-1)) and 0.71 microg.kg(-1) (95% confidence limits, 0.61-1.40 microg.kg(-1)), respectively.

Solid pseudopapillary carcinoma of the pancreas: differentiation from benign solid pseudopapillary tumour using CT and MRI

AIM

To describe the computed tomography (CT) and magnetic resonance imaging (MRI) findings that differentiate solid pseudopapillary carcinomas (SPC) from benign solid pseudopapillary tumours (SPT) of the pancreas.

MATERIALS AND METHODS

Preoperative CT or MRI images for 26 patients (eight patients with SPC and 18 patients with SPT) were retrospectively reviewed. In addition to the general morphological features, the presence of pancreatic duct dilation, vascular invasion, and extrapancreatic metastases were comparatively assessed.

RESULTS

There were no significant differences between pancreatic SPC and benign SPT with respect to tumour size, location, capsule thickness, internal composition, and pattern of calcification, nor was there any correlation with the age and gender of the patients. Pancreatic duct dilation was present in four of the eight (50%) SPC patients, and was absent in all benign SPT patients (p=0.005). Vascular encasement by the tumour (n=2) and hepatic metastases (n=2) were also exclusively demonstrated in SPC patients. Multivariate logistic regression analysis showed that pancreatic duct dilation (p=0.001), vessel encasement (p=0.027), and metastasis (p=0.027) were the variables that can be used to differentiate SPC from benign SPT.

CONCLUSION

SPC of the pancreas may help to differentiate from benign SPT using the imaging features of aggressive behaviour of pancreatic duct dilation and vessel encasement with or without extrapancreatic metastases.

Toxicity of repeated intravenous injection of gene therapeutics for X-CGD in mice

We made gene therapeutics for X-chronic granulomatous disease (CGD) by transducing murine bone marrow-derived stem cells with MT-gp91 retrovirus and evaluated possible toxicity in mice as a prerequisite for human clinical trials. Male C57BL/6 mice were injected intravenously with gene therapeutics for X-CGD twice at an interval of two weeks at 5 × 107 cells/kg and sacrificed 2 weeks after the last administration. Significant changes noted in gene therapeutics for X-CGD-treated animals were an increase in white blood cell counts and a slight decrease in albumin/globulin ratio. The red pulp hyperplasia in the spleen accompanied with an increase in organ weight was considered to result from the accumulation of gene therapeutics for X-CGD, bone marrow-derived stem cells, in the spleen. No anti-gp91 antibody was detected in the sera collected from the animals treated with gene therapeutics for X-CGD. No integration of gp91 DNA from retroviral vector was detected in chromosomal DNA of gonads in animals dosed with the test substance, indicating no potential of genomic integration. In conclusion, the repeated dose of gene therapeutics for X-CGD exerted no toxicity. The splenic red pulp hyperplasia and the increase observed in white blood cell counts and in spleen weights were considered as pharmacological changes induced by the treatment.

Durability of recycled aggregate concrete using pozzolanic materials

In this study, pulverized fuel ash (PFA) and ground granulated blast furnace slag (GGBS) were used to compensate for the loss of strength and durability of concrete containing recycled aggregate. As a result, 30% PFA and 65% GGBS concretes increased the compressive strength to the level of control specimens cast with natural granite gravel, but the tensile strength was still lowered at 28 days. Replacement with PFA and GGBS was effective in raising the resistance to chloride ion penetrability into the concrete body, measured by a rapid chloride ion penetration test based on ASTM C 1202-91. It was found that the corrosion rate of 30% PFA and 65% GGBS concretes was kept at a lower level after corrosion initiation, compared to the control specimens, presumably due to the restriction of oxygen and water access. However, it was less effective in increasing the chloride threshold level for steel corrosion. Hence, it is expected that the corrosion time for 30% PFA and 65% GGBS concrete containing recycled aggregate mostly equates to the corrosion-free life of control specimens.

Novel entry point for intraoperative ventricular puncture during the transsylvian approach

OBJECTIVE

In dealing with cases of oedematous brain, relaxation during the transsylvian approach to supratentorial aneurysms has been accomplished by ventricular drainage by using the anatomic point defined by Dr. Paine. However, we have experienced patient complications when using this point. We propose a novel anatomic point to reduce catheter-related complications and facilitate adequate ventricular puncture during ruptured aneurysm operations.

METHODS

Ten patients underwent aneurysmal neck clipping for ruptured aneurysm by means of the transsylvian approach. The use of a novel anatomic point for intraoperative drainage was examined using a neuronavigation system.

RESULTS

Using the novel point of entry for ventricular cannulation proved to be reliable for puncture and reduced chance of malpositioning.

CONCLUSION

Secure intraoperative ventricular cannulation is reliably achieved by pointing the catheter approximately 2 cm beyond a line extending from the anterior limb of the triangle described by Paine. This technique reduces injury to the deep brain and enhances preciseness and safety of ventricular cannulation.

The P2Y1 receptor is essential for ADP-induced shape change and aggregation in mouse platelets

Adenosine diphosphate (ADP) is an important platelet agonist, causing the shape change and aggregation required for physiological hemostasis. We have recently demonstrated that the P2Y1 receptor plays an important role in ADP-induced shape change and aggregation in human platelets. The role of the P2Y1 receptor in these physiological responses can be conclusively delineated with gene-knockout approaches in transgenic mice. However, before proceeding to the P2Y1 gene-knockout mice generation, it is important to demonstrate that the P2Y1 receptor plays an essential role in ADP-induced shape change and aggregation in mouse platelets. We examined platelets pooled from twenty 129J mice, a strain used in the generation of knockout mice. Immunofluorescence experiments using P2Y1 specific antiserum detected the presence of the P2Y1 receptor on mouse platelets. ARL 66096, a potent P2T(AC) receptor antagonist, caused a dose-dependent inhibition of both ADP-induced aggregation and ADP-induced inhibition of adenylyl cyclase, without affecting shape change or calcium mobilization. On the other hand, adenosine-2'-phosphate-5'-phosphate (A2P5P), a P2Y1 receptor-selective antagonist, caused a dose-dependent inhibition of ADP-induced aggregation and shape change, as well as inhibiting the mobilization of calcium from intracellular stores. A2P5P had no effect on the inhibition of adenylyl cyclase by ADP. These findings clearly demonstrate the existence of two distinct ADP receptors, the P2Y1 and P2T(AC), in mouse platelets with similar function as in human platelets.

Ultra fast symmetry and SIMD-based projection-backprojection (SSP) algorithm for 3-D PET image reconstruction

Remarkable progress in positron emission tomography (PET) development has occurred in recent years, in hardware, software, and computer implementation of image reconstruction. Recent development in PET scanners such as the high-resolution research tomograph (HRRT) developed by CTI (now Siemens) represents such a case and is capable of greatly enhanced resolution as well as sensitivity. In these PET scanners, the amount of coincidence line data collected contains more than 4.5 x 10(9) coincidence lines of response generated by as many nuclear detectors as 120 000. This formidable amount of data and the reconstruction of this data set pose a real problem in HRRT and have also been of the major bottle neck in further developments of high resolution PET scanners as well as their applications. In these classes of PET scanners, therefore, obtaining one set of reconstructed images often requires many hours of image reconstruction. For example, in HRRT with full data collection in a normal brain scan (using SPAN 3), the image reconstruction time is close to 80 min, making it practically impossible to attempt any list-mode-based dynamic imaging since the image reconstruction time would take many days (as much as 43 h or more for 32-frame dynamic image reconstruction). To remedy this data-handling problem in image reconstruction, we developed a new algorithm based on the symmetry properties of the projection and backprojection processes, especially in the 3-D OSEM algorithm where multiples of projection and back-projection are required. In addition, the single-instruction multiple-data (SIMD) technique also allowed us to successfully incorporate the symmetry properties mentioned above, thereby effectively reducing the total image reconstruction time to a few minutes. We refer to this technique as the symmetry and SIMD-based projection-backprojection (SSP) technique or algorithm and the details of the technique will be discussed and an example of the application of the technique to the HRRT's OSEM algorithm will be presented as a demonstration.

Molecular epidemiologic study of a human immunodeficiency virus 1 outbreak in haemophiliacs B infected through clotting factor 9 after 1990

BACKGROUND AND OBJECTIVES

Twenty haemophiliacs were diagnosed as infected with human immunodeficiency virus 1 (HIV-1), 1 to 2 years after exposure to clotting factor 9 manufactured in Korea, beginning in early 1990. This study assessed the genetic relationships between viruses found in plasma donors and haemophiliacs.

MATERIALS AND METHODS

Sequencing of the nef and pol genes of viruses from infected haemophiliacs, plasma donors whose plasma was used in domestic clotting factor manufacture, haemophiliacs infected outside Korea, and local controls were determined by nested polymerase chain reactions and direct DNA sequencing. Phylogenetic analysis was used to investigate the relationships among the sequences.

RESULTS

Both plasma donors and the haemophiliacs were infected with a subclade of subtype B that is a founder effect lineage in Korea.

CONCLUSION

Our data indicate that HIV-1 transmission to 20 haemophiliacs occurred through intravenous injection of Korean-made clotting factor.

SUMMARY

A clotting factor made in Korea from blood from cash-paid donors infected at least 20 haemophiliacs with HIV-1 subtype B.

Evaluation of developmental toxicity of amitraz in Sprague-Dawley rats

This study investigated the potential adverse effects of amitraz on the initiation and maintenance of pregnancy in Sprague-Dawley rats as well as its effects on embryo-fetal development after maternal exposure during the entire pregnancy period. Amitraz was administered to pregnant rats by gavage from days 1 to 19 of gestation at dose levels of 0, 3, 10, and 30 mg/kg/day. All dams underwent a caesarean section on day 20 of gestation and their fetuses were examined for any external, visceral, and skeletal abnormalities. At 30 mg/kg, maternal toxicity manifested as an increase in the incidence of abnormal clinical signs and a lower body weight gain and food intake. Developmental toxicity included an increase in the fetal death rate, a decrease in the litter size, and a reduction in the fetal body weight. In addition, there was an increase in the incidence of fetal external, visceral, and skeletal abnormalities. At 10 mg/kg, maternal toxicity observed included a decrease in the body weight gain and a decrease in food intake. In addition, minimal developmental toxicity, including a decrease in the fetal body weight, an increase in the visceral and skeletal aberrations, and a delay in fetal ossification. There were no signs of either maternal toxicity or developmental toxicity at 3 mg/kg. These results show that amitraz administered during the entire pregnancy period in rats is embryotoxic and teratogenic at the maternally toxic dose (i.e., 30 mg/kg/day) and is minimally embryotoxic at a minimally maternally toxic dose (i.e., 10 mg/kg/day). Under these experimental conditions, the no-observed-adverse-effect level of amitraz for both dams and embryo-fetal development is estimated to be 3 mg/kg/day.

Molecular characterization of the porcine endogenous retrovirus subclass A and B envelope gene from pigs

Xenotransplantation of porcine organs has the potential to overcome the current critical shortage of allogenic organs for transplantation in humans. However, the existence of porcine endogenous retroviruses (PERVs) presents a problem for the clinical use of xenografts from pigs. In an attempt to understand the molecular characteristics of PERVs, we cloned the PERV env gene from six pig breeds (ie, Berkshire, Duroc, Landrace, Yorkshire, and two types of miniature pigs) in Korea. A total of 141 env clones were isolated and their sequences were analyzed. Phylogenetic analyses of these genes revealed the presence of PERVs, from both classes A and B, in 54% and 46% of the env clones, respectively. Among these clones, 37 isolates had the correct open reading frame (ORF; 27 clones in subclass A and 10 clones in subclass B), while the others had premature termination. These PERV nucleotide sequences can be used in a database for comparisons of PERV distribution among different pig breeds and for monitoring PERV infection using isolates with functional ORFs. Recombinant envelope of subclass A and B with functional ORF was expressed by vaccinia virus systems. Additionally isolated env clones can be used for various experiments, such as PERV control and infectivity tests, and may enhance the understanding of molecular mechanisms through pseudotyped PERV viruses.

Pretreatment with remifentanil to prevent withdrawal after rocuronium in children

BACKGROUND

Pain from rocuronium injection is a common side-effect reported to occur in 50-80% of the patients. This randomized, double-blind, placebo-controlled study was designed to evaluate the efficacy of pretreatment with i.v. remifentanil on prevention of withdrawal response during rocuronium injection in paediatric patients.

METHODS

After obtaining parental consents, 70 paediatric patients were randomly allocated into two groups to receive either i.v. remifentanil 1 mug kg(-1) (remifentanil group, n=35) or i.v. saline 5 ml (saline group, n=35). Anaesthesia was induced with thiopental sodium 2.5% (5 mg kg(-1)) and the test drug was injected over 30 s. One minute after the test drug injection, rocuronium 1% (0.6 mg kg(-1)) was injected over 5 s and the response was recorded. Mean arterial pressure (MAP) and heart rate were recorded on arrival in the operating theatre, before and 1 min after the tracheal intubation.

RESULTS

The overall incidence of withdrawal movements was significantly higher in the saline group (33 patients; 94%) than that in the remifentanil group (8 patients; 23%) (P<0.001). No patient in the remifentanil group showed generalized movement, whereas 51% of patients in the saline group did. Remifentanil prevented significant increase in MAP after intubation.

CONCLUSION

This study demonstrated that pretreatment with remifentanil 1 microg kg(-1) provided a safe and simple method for reducing the incidence of rocuronium-associated withdrawal movement with haemodynamic stability in children.

Comparison between Transuncal Approach and Upper Vertebral Transcorporeal Approach for Unilateral Cervical Radiculopathy - A Preliminary Report

OBJECTIVE

The surgical treatments for unilateral cervical radiculopathy have been performed by either the anterior or posterior approach. The anterior approach has usually been used more than the posterior approach. The authors compared the results of newly advanced upper vertebral transcorporeal (UVTC) approach with those of the original transuncal (TU) approach in the anterior approach.

METHODS

The anterior cervical microforaminotomy was performed for 60 patients (male:female=40:20) from June, 2000 to October, 2003. 40 patients were treated by the TU approach while 20 patients were operated on by the new UVTC approach. The authors analyzed postoperative changes of disc height, the spinal instability, the average length of hospital stay, the degree of patients' satisfaction and complications from each approach. The mean follow-up period was 9.5 months.

RESULTS

In the TU approach, postoperative intervertebral disc height was decreased from 7.1+/-0.65 mm to 6.2+/-0.61 mm. In the UVTC approach, postoperative intervertebral disc height was decreased from 6.6+/-0.43 mm to 6.3+/-0.41 mm. The average length of hospital stay was 5.2 days for the TU approach and 3.4 days for the UVTC approach. In the TU approach, 28 patients experienced excellent results, 11 patients experienced good results, one patient who experienced a fair result was operated by anterior cervical fusion because of a recurrent herniated disc. In the UVTC approach, 16 patients had excellent results and four patients experienced good results.

CONCLUSIONS

This comparative study demonstrates that the UVTC approach is a better surgical technique than the TU approach considering the preservation of disc height, spinal stability, length of hospital stay, degree of satisfaction and complications.

Neural substrates, experimental evidences and functional hypothesis of acupuncture mechanisms

OBJECTIVES

Although acupuncture therapy has demonstrated itself to be effective in several clinical areas, the underlying mechanisms of acupuncture in general and the analgesic effect in particular are, however, still not clearly delineated. We, therefore, have studied acupuncture analgesic effect through fMRI and proposed a hypothesis, based on the obtained result, which will enlighten the central role of the brain in acupuncture therapy.

METHODS

The proposed model, termed as a broad sense hypothalamus-pituitary-adrenal (BS-HPA) axis, was based on our observed neuroimaging results. The model incorporates the stress-induced HPA axis model together with neuro-immune interaction including the cholinergic anti-inflammatory model.

RESULTS

The obtained results coupled with accumulating evidence suggest that the central nervous system is essential for the processing of these effects via its modulation of the autonomic nervous system, neuroimmune system and hormonal regulation.

CONCLUSIONS

Based on our fMRI study, it appears that understanding the effects of acupuncture within a neuroscience-based framework is vital. Further, we have proposed the broad sense-HPA axis hypothesis which incorporates the experimental results.

Novel action of gastric proton pump inhibitor on suppression of Helicobacter pylori induced angiogenesis

BACKGROUND

Although activation of mitogen activated protein kinases (MAPKs) by Helicobacter pylori infection is associated with induction of host angiogenesis, which may contribute to H pylori associated gastric carcinogenesis, the strategy for its prevention has not been identified. As we previously reported a strong inhibitory action of gastric proton pump inhibitors (PPIs) on MAPK extracellular signal regulated kinase (ERK)1/2 phosphorylation, we investigated whether PPIs could suppress the H pylori induced angiogenesis via inhibition of MAPK ERK1/2.

METHODS

To address the relationship between H pylori infection and angiogenesis, comparative analysis of density of CD34(+) blood vessel was performed in tissues obtained from 20 H pylori positive gastritis and 18 H pylori negative gastritis patients. Expression of hypoxia inducible factor 1 (HIF-1alpha) and vascular endothelial growth factor (VEGF) was tested by reverse transcription-polymerase chain reaction and secretion of interleukin 8, and VEGF was measured by ELISA. To evaluate the direct effect of H pylori infection on the tubular formation of human umbilical vein endothelial cells (HUVEC), an in vitro angiogenesis assay was employed. Activation of MAPK and nuclear factor kappaB (NFkappaB) was detected by immunoblotting.

RESULTS

H pylori positive gastritis patients showed a higher density of CD34(+) blood vessels (mean 40.9 (SEM 4.4)) than H pylori negative gastritis patients (7.2+/-0.8), which was well correlated with expression of HIF-1alpha. Conditioned media from H pylori infected gastric epithelial cells directly induced tubular formation of HUVEC and the increase of in vitro angiogenesis was suppressed by PPI treatment. Infection of H pylori significantly upregulated expression of HIF-1alpha and VEGF in gastric epithelial cells and expression of proangiogenic factors was mediated by MAPK activation and partially responsible for NFkappaB activation. PPIs effectively inhibited the phosphorylation of MAPK ERK1/2 that is a principal signal for H pylori induced angiogenesis.

CONCLUSIONS

The fact that PPIs could downregulate H pylori induced angiogenesis indicates that antiangiogenic treatment using a PPI could be a promising protective therapeutic approach for H pylori associated carcinogenesis.

Evaluation of spermatogenesis and fertility in F1 male rats after in utero and neonatal exposure to extremely low frequency electromagnetic fields

AIM

To determine whether in utero and neonatal exposure to a 60 Hz extremely low frequency electromagnetic field (EMF) results in spermatotoxicity and reproductive dysfunction in the F1 offspring of rats.

METHODS

Age-matched, pregnant Sprague-Dawley rats were exposed continuously (21 h/day) to a 60 Hz EMF at field strengths of 0 (sham control), 5, 83.3 or 500 microT from day 6 of gestation through to day 21 of lactation. The experimentally generated magnetic field was monitored continuously (uninterrupted monitoring over the period of the study) throughout the study.

RESULTS

No exposure-related changes were found in exposed or sham-exposed animals with respect to the anogenital distance, preputial separation, testis weight, testicular histology, sperm count, daily sperm production, sperm motility, sperm morphology and reproductive capacity of F1 offspring.

CONCLUSION

Exposure of Sprague-Dawley rats to a 60 Hz EMF at field strengths of up to 500 microT from day 6 of gestation to day 21 of lactation did not produce any detectable alterations in offspring spermatogenesis and fertility.

Decreased Helicobacter pylori associated gastric carcinogenesis in mice lacking inducible nitric oxide synthase

BACKGROUND AND AIMS

Overproduction of nitric oxide via inducible nitric oxide synthase (iNOS) is suggested to be a significant pathogenic factor in Helicobacter pylori induced gastritis. The purpose of this study was to examine the role of iNOS in H pylori associated gastric carcinogenesis.

METHODS

Two types of mice were used in this study: iNOS deficient mice (iNOS-/-) and wild-type littermates. Gastric cancer was generated in mice using a combination treatment comprising N-methyl-N-nitrosourea administration and H pylori infection. Fifty weeks after treatment, tumours in gastric tissues from both types of mice were examined using histopathology, immunohistochemistry, and immunoblotting for iNOS and 3-nitrotyrosine.

RESULTS

The overall incidence of gastric cancer at week 50 was significantly lower in iNOS-/- compared with iNOS wild-type mice (p<0.05). When analysed according to tumour pathology, the incidence of gastric adenocarcinoma was significantly lower in iNOS-/- compared with iNOS wild-type mice (p<0.05). Immunostaining for iNOS was clearly observed in adenocarcinoma cells of iNOS wild-type mice, and was characterised by a strong cytoplasmic expression pattern. 3-Nitrotyrosine was expressed mostly in the area of the lamina propria of gastritis and adenoma lesions in iNOS wild-type mice. Immunoblotting analyses showed that iNOS and 3-nitrotyrosine were also expressed in both adenoma and adenocarcinoma tissues from iNOS wild-type mice. iNOS and 3-nitrotyrosine expression was greater in tumour tissues than in non-tumour tissues.

CONCLUSIONS

These findings suggest that iNOS contributes to H pylori associated gastric carcinogenesis in mice.

Estimation of the daily exposure of Koreans to aflatoxin B1 through food consumption

A survey for aflatoxin B(1) (AFB(1)) was conducted on 88 food-grade rice samples randomly collected during July and August 2002 in Seoul, Korea. The presence of AFB(1) was determined by enzyme-linked immunosorbent assay, and the positive samples from enzyme-linked immunosorbent assay were confirmed using high-performance liquid chromatography. Besides this, from the surveying data from the literature published since 1997, the intake of AFB(1) from food in Korea was calculated and compared with the provisional maximum tolerable daily intakes. Naturally occurring AFB(1) was found in 5/88 (6%) samples of rice with an average of 4.8 ng g(-1). A calculated probable daily intake of AFB(1) for Koreans fell into the range 1.19-5.79 ng kg(-1) bw day(-1), hence exceeding the estimated provisional maximum tolerable daily intakes. In conclusion, the exposure of Koreans to AFB(1) could bring about health concerns. This is the first report discovering that rice is the major contributor to the dietary intake of AFB(1) in Korea.

Preferential expression of L-type amino acid transporter 1 in ameloblasts during rat tooth development

Certain amino acid transport systems play an important role in supplying organic nutrients to each cell and for cell proliferation during tooth development. However, the mechanisms responsible for such actions are unclear. This study demonstrated for the first time that LAT1 and 4F2hc are expressed during tooth development in prenatal and postnatal rats, and that the transporters show cell-specific expression in ameloblasts, which are the epithelium-derived dental cells. LAT1 and 4F2hc expression was not observed in other dental cells of the developing teeth such as odontoblasts and cementoblasts. Overall, these results suggest that LAT1 and 4F2hc might play an important role in enamel formation.