Mid-Term Outcomes of Aortic Valve Repair Without Aortic Root Replacement: A Single-Center Experience.

Background Aortic valve (AV) repair is a challenging procedure due to its complexity, lower reproducibility, and steep learning curve. To examine its durability and validity, we investigated mid-term outcomes following AV repair without aortic root replacement. Methods Between March 2007 and May 2018, we retrospectively identified 14 patients who underwent AV repair without aortic root replacement at our institution. We investigated their baseline characteristics and postoperative outcomes, including the reoperation rate due to aortic regurgitation (AR) recurrence. Furthermore, we divided them into two groups: those who required reoperation due to AR recurrence (Group R) and those who did not require reoperation (Group F), and statistically compared them. Results The median age was 52.5 years (IQR: 42.0-60.8), with 11 male patients (78.6%). Eight patients (57.1%) had a bicuspid AV. Five cases (35.7%) underwent reoperation due to AR recurrence during a median follow-up period of 5.5 years. There were no significant differences in baseline characteristics between Group R (n=5, 35.7%) and Group F (n=9, 64.3%), including AR etiology, AV repair procedure, and intraoperative AR grade after the final declamp. All cases in Group R had at least mild to moderate AR on the echocardiogram before discharge. Regarding the AR grade before discharge, Group R had a significantly higher grade than Group F (p = 0.013). Conclusions The indication for AV repair for AR might need to be reassessed due to the considerable mid-term reoperation rate. Cases of AV repair with more than mild AR at discharge should be carefully monitored, as they are likely to require future reoperation for AR.

A case of surgical treatment for recurrence of right ventricular metastasis due to renal cell carcinoma after molecular targeted therapy.

BACKGROUND: Cardiac metastasis including the right ventricle from renal cell carcinoma is rare. No standard treatment for cardiac metastasis and recurrence in renal cell carcinoma has been established. CASE PRESENTATION: We present the case of a 61-year-old man who underwent the resection of recurrent right ventricular metastasis caused by renal cell carcinoma following molecular targeted therapy. The first cardiac operation was performed for right ventricular metastasis due to renal cell carcinoma. The patient had a good postoperative course. Two years after the first operation, however, follow-up computed tomography revealed the recurrence of the right ventricular tumor and metastases in both lungs. Molecular targeted therapy was carried out and effectively controlled the lung metastasis but the right ventricular lesion remained unchanged, leading to reoperation. The recurrent right ventricular tumor was completely resected through a redo median sternotomy assisted by cardiopulmonary bypass. The patient had an uneventful postoperative course and was discharged on the 13th postoperative day. Follow-ups at 2 years showed no cardiac recurrence. CONCLUSION: Surgical intervention was considered useful in managing the recurrence of right ventricular metastasis from renal cell carcinoma after molecular targeted therapy.

Protocol improvement and multisite validation of a digital soft agar colony formation assay for tumorigenic transformed cells intermingled in cell therapy products.

BACKGROUND AIMS: The administration of human cell-processed therapeutic products (hCTPs) is associated with a risk of tumorigenesis due to the transformed cellular contaminants. To mitigate this risk, these impurities should be detected using sensitive and validated assays. The digital soft agar colony formation (D-SAC) assay is an ultrasensitive in vitro test for detecting tumorigenic transformed cells in hCTPs. METHODS: In this study, we first evaluated the colony formation efficiency (CFE) precision of tumorigenic reference cells in positive control samples according to a previously reported D-SAC assay protocol (Protocol I) from multiple laboratories. However, the CFE varied widely among laboratories. Thus, we improved and optimized the test protocol as Protocol II to reduce variability in the CFE of tumorigenic reference cells. Subsequently, the improved protocol was validated at multiple sites. Human mesenchymal stromal cells (hMSCs) were used as model cells, and positive control samples were prepared by spiking them with HeLa cells. RESULTS: Based on the previously reported protocol, the CFE was estimated using an ultra-low concentration (0.0001%) of positive control samples in multiple plates. Next, we improved the protocol to reduce the CFE variability. Based on the CFE results, we estimated the sample size as the number of wells (Protocol II) and assessed the detectability of 0.0001% HeLa cells in hMSCs to validate the protocol at multiple sites. Using Protocol I yielded low CFEs (mean: 30%) and high variability between laboratories (reproducibility coefficient of variance [CV]: 72%). In contrast, Protocol II, which incorporated a relatively high concentration (0.002%) of HeLa cells in the positive control samples, resulted in higher CFE values (mean: 63%) and lower variability (reproducibility CV: 18%). Moreover, the sample sizes for testing were estimated as the number of wells per laboratory (314-570 wells) based on the laboratory-specific CFE (42-76%). Under these conditions, all laboratories achieved a detection limit of 0.0001% HeLa cells in hMSCs in a predetermined number of wells. Moreover, colony formation was not observed in the wells seeded with hMSCs alone. CONCLUSIONS: The D-SAC assay is a highly sensitive and robust test for detecting malignant cells as impurities in hCTPs. In addition, optimal assay conditions were established to test tumorigenic impurities in hCTPs with high sensitivity and an arbitrary false negative rate.

Dentigerous cysts suspected the other odontogenic lesions on panoramic radiography and CT.

Dentigerous cysts are known as the second most common type of cyst in the jaws. The cyst is one of the lesions occurred frequently in the posterior body of the mandible and is often related to the unerupted third molar and forms around the crown of the unerupted tooth attaching at the cementoenamel junction. Such characteristic appearances are the diagnostic points differentiating from ameloblastoma or odontogenic keratocyst. However, it would be hard for us to diagnose it as a dentigerous cyst if the lesion does not show its typical appearance. We experienced two cases of dentigerous cysts which did not form around the crown of the unerupted tooth on radiologically. Both cysts were relatively large and resorbed adjacent teeth roots. Therefore, an ameloblastoma or an odontogenic keratocyst was suspected rather than a dentigerous cyst as the imaging diagnosis. The biopsy revealed that the lesion was a "dentigerous cyst" in one of the cases and "developmental cyst with inflammation" in another case. After the excision, the histopathological diagnosis was a dentigerous cyst with inflammation in both cases. This report shows the two cases of dentigerous cysts focusing on panoramic radiography and CT images. Also, we discuss the differential diagnosis by reconsidering those diagnostic points.

Thoracic Endovascular Aortic Repair on Zone 2 Landing for Uncomplicated Type B Aortic Dissection with Measurement of Intra-False Lumen Pressure.

BACKGROUND: This study aimed to evaluate the midterm results of zone 2 thoracic endovascular aortic repair (TEVAR) for uncomplicated type B aortic dissection (TBAD) by measuring the intra-false lumen pressure (IFLP) during TEVAR. METHODS: Fifteen patients (9 men; mean age, 57 years) who underwent zone 2 TEVAR for uncomplicated TBAD were reviewed. Delta systolic pressure (defined as the difference between systemic pressure and IFLP) was measured before and after primary entry closure, and aortic remodeling and thrombo-occlusion of the false lumen (FL) were evaluated 12 months after TEVAR at 5 different levels of the aorta. RESULTS: Median duration from onset to TEVAR was 34 days. The left subclavian artery was preserved in 13 patients (87%) by using stent graft fenestration. Although 1 patient (6%) had a transient cerebral infarction, there were no severe TEVAR-related complications. Entry closure significantly reduced delta systolic pressure (mm Hg) compared to preoperative pressure at all levels (distal arch: -22.2 ± 10.8 vs. -5.2 ± 9.6; Th8: -20.1 ± 12.4 vs. -6.9 ± 7.2; Th10: -14.3 ± 14.6 vs. -4.7 ± 7.5; Th12: -14.4 ± 14.5 vs. -4.9 ± 7.8; L2: -14.5 ± 14.2 vs. -3.4 ± 6.9). The percentages of aortic remodeling with expansion of the true lumen (distal arch: 82%; Th8: 80%; Th10: 54%; Th12: 45%; L2: 50%) and complete false lumen thrombosis (distal arch: 100%; Th8: 100%; Th10: 67%; Th12: 11%; L2: 0%) were approximately consistent with the change in delta systolic pressure. During a follow-up of 41 months, distal stent-induced new entry occurred in 2 patients (13%) requiring secondary intervention; however, there were no cases of FL enlargement or aorta-related mortality. CONCLUSIONS: Zone 2 TEVAR for uncomplicated TBAD may prevent TEVAR-related complications. Measuring IFLP could be a new predictive marker for assessing the extent of aortic remodeling.

Bacterial mutagenicity test data: collection by the task force of the Japan pharmaceutical manufacturers association.

BACKGROUND: Ames test is used worldwide for detecting the bacterial mutagenicity of chemicals. In silico analyses of bacterial mutagenicity have recently gained acceptance by regulatory agencies; however, current in silico models for prediction remain to be improved. The Japan Pharmaceutical Manufacturers Association (JPMA) organized a task force in 2017 in which eight Japanese pharmaceutical companies had participated. The purpose of this task force was to disclose a piece of pharmaceutical companies' proprietary Ames test data. RESULTS: Ames test data for 99 chemicals of various chemical classes were collected for disclosure in this study. These chemicals are related to the manufacturing process of pharmaceutical drugs, including reagents, synthetic intermediates, and drug substances. The structure-activity (mutagenicity) relationships are discussed in relation to structural alerts for each chemical class. In addition, in silico analyses of these chemicals were conducted using a knowledge-based model of Derek Nexus (Derek) and a statistics-based model (GT1_BMUT module) of CASE Ultra. To calculate the effectiveness of these models, 89 chemicals for Derek and 54 chemicals for CASE Ultra were selected; major exclusions were the salt form of four chemicals that were tested both in the salt and free forms for both models, and 35 chemicals called "known" positives or negatives for CASE Ultra. For Derek, the sensitivity, specificity, and accuracy were 65% (15/23), 71% (47/66), and 70% (62/89), respectively. The sensitivity, specificity, and accuracy were 50% (6/12), 60% (25/42), and 57% (31/54) for CASE Ultra, respectively. The ratio of overall disagreement between the CASE Ultra "known" positives/negatives and the actual test results was 11% (4/35). In this study, 19 out of 28 mutagens (68%) were detected with TA100 and/or TA98, and 9 out of 28 mutagens (32%) were detected with either TA1535, TA1537, WP2uvrA, or their combination. CONCLUSION: The Ames test data presented here will help avoid duplicated Ames testing in some cases, support duplicate testing in other cases, improve in silico models, and enhance our understanding of the mechanisms of mutagenesis.

Oxidative Synthesis of Acid Blue 7 Dye Catalyzed by CuO/Silicotungstic Acid in Water-Phase.

A catalytic oxidation reaction for Acid Blue 7 dye synthesis was evaluated in water. Without lead oxide or manganese oxide derivatives as oxidants, polyoxometalate catalysts were investigated to reduce the usage of harmful heavy metal. A catalyst was prepared by mixing silicotungstic acid with copper oxide, and aqueous hydrogen peroxide (30%) was used as an oxidizing agent. This reaction proceeded to produce Acid Blue 7 from the corresponding leuco acid after 45 min at 95 °C and was viable for a 10 g-scale synthesis.

Weight of evidence approach using a TK gene mutation assay with human TK6 cells for follow-up of positive results in Ames tests: a collaborative study by MMS/JEMS.

BACKGROUND: Conflicting results between bacterial mutagenicity tests (the Ames test) and mammalian carcinogenicity tests might be due to species differences in metabolism, genome structure, and DNA repair systems. Mutagenicity assays using human cells are thought to be an advantage as follow-up studies for positive results in Ames tests. In this collaborative study, a thymidine kinase gene mutation study (TK6 assay) using human lymphoblastoid TK6 cells, established in OECD TG490, was used to examine 10 chemicals that have conflicting results in mutagenicity studies (a positive Ames test and a negative result in rodent carcinogenicity studies). RESULTS: Two of 10 test substances were negative in the overall judgment (20% effective as a follow-up test). Three of these eight positive substances were negative after the short-term treatment and positive after the 24 h treatment, despite identical treatment conditions without S9. A toxicoproteomic analysis of TK6 cells treated with 4-nitroanthranilic acid was thus used to aid the interpretation of the test results. This analysis using differentially expressed proteins after the 24 h treatment indicated that in vitro specific oxidative stress is involved in false positive response in the TK6 assay. CONCLUSIONS: The usefulness of the TK6 assay, by current methods that have not been combined with new technologies such as proteomics, was found to be limited as a follow-up test, although it still may help to reduce some false positive results (20%) in Ames tests. Thus, the combination analysis with toxicoproteomics may be useful for interpreting false positive results raised by 24 h specific reactions in the assay, resulting in the more reduction (> 20%) of false positives in Ames test.

Recombinant Thrombomodulin Suppresses Histone-Induced Neutrophil Extracellular Trap Formation.

Histones, the major protein components of chromatin, are released into the extracellular space during sepsis, trauma, and ischemia-reperfusion injury, and subsequently mediate organ failure. Extracellular histones can promote endothelial damage and platelet aggregation, which can be suppressed by administration of recombinant thrombomodulin (rTM). The present study aimed to clarify whether histones can activate neutrophils to induce NET formation and whether rTM can prevent histone-induced NET formation. NET formation was analyzed in vitro by stimulating human neutrophils with histones in the absence or presence of rTM. NET formation was further analyzed in vivo by intravenous infusion of histones into rats with or without rTM. Histones induced NET release in a dose-dependent manner in vitro and NET release was induced as early as 1 h after stimulation. Histone-induced NET release was independent of NADPH oxidase. rTM suppressed histone-induced NET release in vitro as well as in vivo. The suppression might be mediated by rTM binding to histones, as suggested by analysis using a quartz crystal microbalance system. The present findings suggest that histones can activate neutrophils to form NETs and that rTM can inhibit histone-induced NET formation.

Application of high-mannose-type glycan-specific lectin from Oscillatoria Agardhii for affinity isolation of tumor-derived extracellular vesicles.

Tumor cells secrete membrane vesicles of various sizes, termed extracellular vesicles (EVs), which have gained increasing attention as potential tumor diagnostic markers. Tumor-derived EVs are enriched with high-mannose-type glycans. Here, we report the affinity isolation of EVs from human melanoma A375 cells by using high-mannose-type glycan-specific agglutinin from Oscillatoria Agardhii (OAA). Glycan analysis of melanoma EVs revealed the presence of high-mannose-type glycans with structural units preferred by OAA. We showed that in solution, OAA binds to melanoma EVs in a high-mannose-type glycan-dependent manner. Furthermore, OAA-immobilized beads were found to capture 60% of the particles and most proteinous components from melanoma EVs. Major EV glycoproteins that potentially interact with OAA were identified to be cluster of differentiation 109 (CD109), integrin α6 and a disintegrin and metalloproteinase domain-containing protein 10 (ADAM10). In addition to melanoma EVs, OAA captured EVs from human lung cancer, glioblastoma and colon cancer cells, but not those from endothelial cells and fibroblasts. These results indicate that OAA-immobilized beads may serve as a novel platform for affinity-capture of tumor-derived EVs.

Generation of the heterogeneity of extracellular vesicles by membrane organization and sorting machineries.

BACKGROUND: Cells secrete heterogeneous populations of extracellular vesicles (EVs) via unknown mechanisms. EV biogenesis has been postulated to involve lipid-protein clusters, also known as membrane microdomains. METHODS: Membrane properties and heterogeneity of melanoma-derived EVs were analyzed by a detergent solubilization assay, sucrose density gradient ultracentrifugation and immunoprecipitation. EV secretion was modulated by RNA interference and pharmacological treatments. RESULTS: We identified two EV membranes (low-density exosomal detergent-insoluble membranes [EV-DIMs]; EV detergent-soluble membranes [EV-DSMs]) and discovered an abundant, novel type of high-density EV-DIMs. The high-density EV-DIMs accumulated the microdomain-resident protein flotillin-1, as well as a disintegrin and metalloproteinase domain containing protein 10 (Adam10), the hepatocyte growth factor receptor Met and its proteolytic fragments. Low-density EV-DIMs also contained flotillin-1. EV-DSMs were enriched with tetraspanin CD81, melanogenic enzymes and proteolytic fragments of Adam10. Intact and fragmented forms of Adam10, which resided in distinct membrane types, were secreted by different EVs. The fragmented form of Met was associated with DIMs much more efficiently than the intact form and they were secreted by distinct EVs. We identified that the endosomal sorting complexes required for transport machinery was indispensable for EV secretion of both mature and fragmented forms of Adam10 and Met. CONCLUSION: The findings of this study reveal the role of the interplay between membrane organization and sorting machineries in generating the heterogeneity of EVs. GENERAL SIGNIFICANCE: This study provides novel insights into important aspects of EV biogenesis.

Evaluating the mandibular condyles of patients with osteoarthritis for bone marrow abnormalities using magnetic resonance T2 mapping.

OBJECTIVES: This study investigated whether erosion and osteophyte correlates with condyle bone marrow abnormalities (BMA), as detected with quantitative T2 mapping. METHODS: Fifty-six joints (in 44 patients) that demonstrated evidence of bony erosion (ER) or osteophytes (OS) related to disc displacement without reduction were studied with MR images. A control group of 50 joints (in 50 patients) was included. The subjects were divided into five groups; noAR (control), noBMA-ER, BMA-ER, noBMA-OS, and BMA-OS. T2 mapping was performed and the regions of interest were placed over the bone marrow at the top of the condyle. The mean T2 values of the bone marrow of the mandibular condyle were calculated for all mapping images. After assessing age-related changes in T2 values of noAR group using Pearson's product-moment, differences in median T2 values of five groups were analyzed using Kruskal-Wallis test, and Steel-Dwass test (p < 0.05). RESULTS: There was no significant correlation between age and T2 value in noAR group. The median T2 values of noBMA-ER and BMA-ER groups were significantly higher than those of noAR, noBMA-OS and BMA-OS groups. Those of noBMA-OS and BMA-OS groups were significantly lower than those of noAR, noBMA-ER and BMA-ER groups. There was no significant difference between noBMA and BMA groups. CONCLUSIONS: It is suggested that erosion and osteophyte of the condyle may correlate with bone marrow abnormalities. T2 mapping could be show slight marrow changes of the arthritic condyle.

Differences in signal intensities of temporomandibular joint (TMJ) effusion on fluid-attenuated inversion recovery (FLAIR) images.

OBJECTIVES: Joint effusion is demonstrated by high signal intensity in the upper and lower temporomandibular joint (TMJ) spaces on T2-weighted images. The fluid-attenuated inversion recovery (FLAIR) technique can be applied to analyze joint effusion in the TMJ. FLAIR signal intensity can be more sensitively influenced by the contents of joint effusion than T2-weighted signal intensity. The purpose of this study was to analyze the signal intensity of joint effusion on FLAIR images and to investigate the changes in joint effusion contents according to the status of TMJ disorders. METHODS: A total of 48 joints (45 patients) with joint effusion were investigated by magnetic resonance (MR) imaging. Regions of interest were placed over the joint effusion and gray matter on FLAIR images. The joints were categorized as normal disk position (NL), disk displacement with reduction (DWR), disk displacement without reduction (DWOR), and osteoarthritis (OA). The signal intensity ratio of joint effusion was calculated using gray matter as the reference point. The Kruskal-Wallis test and Steel test were applied. A probability of less than 0.05 was considered statistically significant. RESULTS: The median signal intensity ratios of joint effusion differed significantly among the four joint categories (p = 0.02, Kruskal-Wallis test). The median signal intensity ratio of joint effusion in the OA category was significantly higher than that in the NL category (p = 0.04, Steel test). CONCLUSIONS: The present findings suggest that FLAIR images can demonstrate the changes in joint effusion contents according to the status of TMJ disorders.

Evaluation of lateral pterygoid muscles in painful temporomandibular joints by signal intensity on fluid-attenuated inversion recovery images.

OBJECTIVES: Pathological changes of the lateral pterygoid muscle (LPM) have been investigated using various modalities, including magnetic resonance (MR) imaging and electromyography. Fluid-attenuated inversion recovery (FLAIR) is an MR sequence that we hypothesized can be used to evaluate abnormalities of the LPM. The purpose of this study was to analyze the FLAIR signal intensity of the LPM in painful temporomandibular joints (TMJs) and investigate the pathological changes of the muscle. METHODS: The study was based on 149 TMJs of 77 patients who were referred for MR imaging of the TMJ. Patients rated their degree of pain during chewing and mouth opening using a visual analog scale (VAS). Regions of interest were placed over the superior and inferior heads of the LPM and gray matter on FLAIR sagittal images. Using the signal intensity of gray matter as a reference, the signal intensity ratio (SIR) of the LPM was calculated. Spearman's rank-correlation coefficient was used to analyze the correlation between the SIR and the VAS score (p < 0.05). RESULTS: A significant correlation was present between the SIR on FLAIR images and the VAS score. CONCLUSIONS: These results suggest that the FLAIR signal intensity of the superior and inferior heads of the LPM significantly increases as TMJ pain becomes more severe. Thus, FLAIR could be useful in assessing the relationship between the MR signals of the LPM and clinical symptoms.

Uric acid enhances alteplase-mediated thrombolysis as an antioxidant.

Uric acid (UA) therapy may prevent early ischemic worsening after acute stroke in thrombolysis patients. The aim of this study was to examine the influence of UA on the thrombolytic efficacy of alteplase in human blood samples by measuring thrombolysis under flow conditions using a newly developed microchip-based flow-chamber assay. Human blood samples from healthy volunteers were exposed to UA, alteplase, or a combination of UA and alteplase. Whole blood and platelet-rich plasma were perfused over a collagen- and thromboplastin-coated microchip, and capillary occlusion was monitored with a video microscope and flow-pressure sensor. The area under the curve (extent of thrombogenesis or thrombolysis) at 30 minutes was 92% lower in the UA-alteplase-treated group compared with the alteplase-treated group. D-dimers were measured to evaluate these effects in human platelet-poor plasma samples. Although hydrogen peroxide significantly decreased the elevation of D-dimers by alteplase, UA significantly inhibited the effect of hydrogen peroxide. Meanwhile, rat models of thromboembolic cerebral ischemia were treated with either alteplase or UA-alteplase combination therapy. Compared with alteplase alone, the combination therapy reduced the infarct volume and inhibited haemorrhagic transformation. UA enhances alteplase-mediated thrombolysis, potentially by preventing oxidative stress, which inhibits fibrinolysis by alteplase in thrombi.

Atypical MRI and Histopathological Findings in Dermoid Cyst.

On images, a dermoid cyst is often described as resembling a "sack of marbles" or "marbles in a bag". Typically, it comprises an inhomogeneity filled with multiple nodules in a fluid matrix on both computed tomography and magnetic resonance imaging (MRI). How it appears, however, will vary depending on its histological contents, which may cause confusion in arriving at a diagnosis. This report describes a dermoid cyst in the floor of the mouth of a 55 year-old woman that showed an atypical internal appearance on MRI. Most of the lesion showed homogeneous high signal intensity on T1 - and T2-weighted images, suggesting that it was derived from fat. A small area within the mass, however, showed moderate signal intensity almost equal to that of muscle on T1-weighted images and high signal intensity on fat-suppressed T2-weighted images. Given the location of the lesion, a dermoid cyst was one possible diagnosis. A lipoma or lipoma variants were also considered, however, based on signal intensity. Histopathological section of the excised specimen revealed a dermoid cyst with sebaceous glands in its walls and keratin in its cavity. Dermoid cysts show variation in their internal structures and contents. Since MRI can reflect such histological variation, signal intensity requires careful interpretation.

Edaravone, a Synthetic Free Radical Scavenger, Enhances Alteplase-Mediated Thrombolysis.

The combination of alteplase, a recombinant tissue plasminogen activator, and edaravone, an antioxidant, reportedly enhances recanalization after acute ischemic stroke. We examined the influence of edaravone on the thrombolytic efficacy of alteplase by measuring thrombolysis using a newly developed microchip-based flow-chamber assay. Rat models of embolic cerebral ischemia were treated with either alteplase or alteplase-edaravone combination therapy. The combination therapy significantly reduced the infarct volume and improved neurological deficits. Human blood samples from healthy volunteers were exposed to edaravone, alteplase, or a combination of alteplase and edaravone or hydrogen peroxide. Whole blood was perfused over a collagen- and thromboplastin-coated microchip; capillary occlusion was monitored with a video microscope and flow-pressure sensor. The area under the curve (extent of thrombogenesis or thrombolysis) at 30 minutes was 69.9% lower in the edaravone-alteplase- than alteplase-treated group. The thrombolytic effect of alteplase was significantly attenuated in the presence of hydrogen peroxide, suggesting that oxidative stress might hinder thrombolysis. D-dimers were measured to evaluate these effects in human platelet-poor plasma samples. Although hydrogen peroxide significantly decreased the elevation of D-dimers by alteplase, edaravone significantly inhibited the decrease. Edaravone enhances alteplase-mediated thrombolysis, likely by preventing oxidative stress, which inhibits fibrinolysis by alteplase in thrombi.

Imaging Findings in AIDS-related Oral Kaposi's Sarcoma.

Kaposi's sarcoma (KS) is one of the most common diseases in patients with acquired immunodeficiency syndrome, but is rarely encountered in dental practice in Japan. We encountered a case of oral KS (OKS) presenting in the hard palate, gingiva, and tongue in a 41-year-old man. We report the results of imaging, including computed tomography (CT), magnetic resonance imaging, and positron emission tomography/CT in this case. The process leading to an imaging diagnosis of OKS is discussed, emphasizing the importance of collating clinical, laboratory, pathological, and radiological findings. The present results suggest that mapping of accurate tumors is very important in cases of OKS, and that multiple or bilateral manifestations, ill-defined margins, osteolysis, and swollen lymph nodes, in particular, need to be taken into account.

The PIGRET assay, a method for measuring Pig-a gene mutation in reticulocytes, is reliable as a short-term in vivo genotoxicity test: Summary of the MMS/JEMS-collaborative study across 16 laboratories using 24 chemicals.

The in vivo mutation assay using the X-linked phosphatidylinositol glycan class A gene (Pig-a in rodents, PIG-A in humans) is a promising tool for evaluating the mutagenicity of chemicals. Approaches for measuring Pig-a mutant cells have focused on peripheral red blood cells (RBCs) and reticulocytes (RETs) from rodents. The recently developed PIGRET assay is capable of screening >1×106 RETs for Pig-a mutants by concentrating RETs in whole blood prior to flow cytometric analysis. Additionally, due to the characteristics of erythropoiesis, the PIGRET assay can potentially detect increases in Pig-a mutant frequency (MF) sooner after exposure compared with a Pig-a assay targeting total RBCs (RBC Pig-a assay). In order to test the merits and limitations of the PIGRET assay as a short-term genotoxicity test, an interlaboratory trial involving 16 laboratories was organized by the Mammalian Mutagenicity Study Group of the Japanese Environmental Mutagenicity Society (MMS/JEMS). First, the technical proficiency of the laboratories and transferability of the assay were confirmed by performing both the PIGRET and RBC Pig-a assays on rats treated with single doses of N-nitroso-N-ethylurea. Next, the collaborating laboratories used the PIGRET and RBC Pig-a assays to assess the mutagenicity of a total of 24 chemicals in rats, using a single treatment design and mutant analysis at 1, 2, and 4 weeks after the treatment. Thirteen chemicals produced positive responses in the PIGRET assay; three of these chemicals were not detected in the RBC Pig-a assay. Twelve chemicals induced an increase in RET Pig-a MF beginning 1 week after dosing, while only 3 chemicals positive for RBC Pig-a MF produced positive responses 1 week after dosing. Based on these results, we conclude that the PIGRET assay is useful as a short-term test for in vivo mutation using a single-dose protocol.

Evaluation of in vivo gene mutation with etoposide using Pig-a and PIGRET assays.

The Pig-a assay detects the expression of the endogenous phosphatidylinositol glycan anchor biosynthesis, class A gene (Pig-a) as a reporter of mutations and shows promise for detecting mutations in vivo. This assay requires two to four weeks to detect mutations in erythrocytes after animals are administered a single dose of test compound. In contrast, the more recently developed PIGRET assay using reticulocytes detects mutation sensitively one week after dosing, which is an advantage for conducting short-term genotoxicity studies in vivo. As part of the Japanese Environmental Mutagen Society/Mammalian Mutagenicity Study Group collaborative study, we conducted Pig-a and PIGRET assays to detect Pig-a mutations in rats treated with etoposide. The DNA topoisomerase II-inhibitor, etoposide, causes DNA cleavage and subsequent protein-linked DNA double-strand breaks, induces chromosomal aberrations and micronuclei, and is classified as 2A (probably carcinogenic to humans) by IARC. Etoposide was intravenously given once to 7-week old SD rats at doses of 0, 5, 10, and 20mg/kg. Severe myelosuppression was induced 2days after dosing in all dosing groups. We conducted Pig-a mutant analysis in Pig-a and PIGRET assays 1, 2, and 4 weeks after dosing. Neither Pig-a nor PIGRET assays showed any statistically significant increases in Pig-a mutant frequency in any of the dose groups at any of the sampling times. It was concluded that etoposide was judged negative in Pig-a and PIGRET assays of bone marrow cells, and the results of the two assays showed hardly any differences.