Visualization and automatic detection of defect distribution in GaN atomic structure from sampling Moiré phase.

Quantitative detection of defects in atomic structures is of great significance to evaluating product quality and exploring quality improvement process. In this study, a Fourier transform filtered sampling Moiré technique was proposed to visualize and detect defects in atomic arrays in a large field of view. Defect distributions, defect numbers and defect densities could be visually and quantitatively determined from a single atomic structure image at low cost. The effectiveness of the proposed technique was verified from numerical simulations. As an application, the dislocation distributions in a GaN/AlGaN atomic structure in two directions were magnified and displayed in Moiré phase maps, and defect locations and densities were detected automatically. The proposed technique is able to provide valuable references to material scientists and engineers by checking the effect of various treatments for defect reduction.

Combined effects of starvation and butyrate on autophagy-dependent gingival epithelial cell death.

BACKGROUND AND OBJECTIVE: Bacteria in the dental biofilm surrounding marginal gingival grooves cause periodontal diseases. Numerous bacteria within the biofilm consume nutrients from the gingival crevicular fluid. Furthermore, some gram-negative bacteria in mature dental biofilms produce butyrate. Thus, gingival epithelial cells in close proximity to mature dental biofilms are at risk of both starvation and exposure to butyrate. In the present study, we determined the combined effects of starvation and butyrate exposure on gingival epithelial cell death and the underlying mechanisms. MATERIAL AND METHODS: The Ca9-22 cell line was used as an in vitro counterpart of gingival epithelial cells. Cell death was measured as the amount of total DNA in the dead cells using SYTOX Green dye, which penetrates through membranes of dead cells and emits fluorescence when it intercalates into double-stranded DNA. AMP-activated protein kinase (AMPK) activity, the amount of autophagy, and acetylation of histone H3 were determined using western blot. Gene expression levels of microtubule-associated protein 1 light chain 3b (lc3b) were determined using quantitative reverse transcription-polymerase chain reaction. RESULTS: Butyrate-induced cell death occurred in a dose-dependent manner whether cells were starved or fed. However, the induction of cell death was two to four times higher when cells were placed under starvation conditions compared to when they were fed. Moreover, both starvation and butyrate exposure induced AMPK activity and autophagy. While AMPK inactivation resulted in decreased autophagy and butyrate-induced cell death under conditions of starvation, AMPK activation resulted in butyrate-induced cell death when cells were fed. Combined with the results of our previous report, which demonstrated butyrate-induced autophagy-dependent cell death, the results of this study suggest that the combination of starvation and butyrate exposure activates AMPK inducing autophagy and subsequent cell death. Notably, this combination markedly induced LC3B production and the induction was attenuated by AMPK inhibition. LC3B knockdown, in turn, significantly decreased butyrate-induced cell death. Therefore, AMPK-dependent LC3B induction apparently plays an important role in butyrate-induced cell death. There was a lack of correspondence between the levels of AMPK activation and LC3B induction; this may reflect the histone deacetylase-inhibitory capacity of butyrate on histone proteins. CONCLUSION: Taken together, starvation and butyrate exposure promote autophagy via AMPK signaling, while the histone deacetylase-inhibitory effects of butyrate alter chromatin to transcriptionally active state, resulting in strong LC3B induction and subsequent cell death. These findings may help improve the understanding of the cellular processes underlying periodontal disease initiation.

A Distinct Subpopulation of Bone Marrow Mesenchymal Stem Cells, Muse Cells, Directly Commit to the Replacement of Liver Components.

Genotyping graft livers by short tandem repeats after human living-donor liver transplantation (n = 20) revealed the presence of recipient or chimeric genotype cases in hepatocytes (6 of 17, 35.3%), sinusoidal cells (18 of 18, 100%), cholangiocytes (15 of 17, 88.2%) and cells in the periportal areas (7 of 8, 87.5%), suggesting extrahepatic cell involvement in liver regeneration. Regarding extrahepatic origin, bone marrow mesenchymal stem cells (BM-MSCs) have been suggested to contribute to liver regeneration but compose a heterogeneous population. We focused on a more specific subpopulation (1-2% of BM-MSCs), called multilineage-differentiating stress-enduring (Muse) cells, for their ability to differentiate into liver-lineage cells and repair tissue. We generated a physical partial hepatectomy model in immunodeficient mice and injected green fluorescent protein (GFP)-labeled human BM-MSC Muse cells intravenously (n = 20). Immunohistochemistry, fluorescence in situ hybridization and species-specific polymerase chain reaction revealed that they integrated into regenerating areas and expressed liver progenitor markers during the early phase and then differentiated spontaneously into major liver components, including hepatocytes (≈74.3% of GFP-positive integrated Muse cells), cholangiocytes (≈17.7%), sinusoidal endothelial cells (≈2.0%), and Kupffer cells (≈6.0%). In contrast, the remaining cells in the BM-MSCs were not detected in the liver for up to 4 weeks. These results suggest that Muse cells are the predominant population of BM-MSCs that are capable of replacing major liver components during liver regeneration.

High-temperature-required protein A2 as a predictive marker for response to chemotherapy and prognosis in patients with high-grade serous ovarian cancers.

BACKGROUND: High-temperature-required protein A2 (HtrA2), a protein relating with apoptosis in a caspases-dependent and non-dependent manner, has been reported to be associated with chemosensitivity in several human cancers. METHODS: Tissue microarrays made from 142 patients with high-grade serous ovarian adenocarcinoma were evaluated to assess whether HtrA2 expression was related with several clinical parameters. RESULTS: Negative HtrA2 expression was observed in 36 cases (25%) of the patients, and related with significantly lower response rates of primary chemotherapy than those with positive HtrA2 expression (56% vs 83%, P<0.01). In addition, negative HtrA2 expression was identified as an independent worse prognostic factor for progression-free survival and overall survival by multivariate analyses. Furthermore, HtrA2 downregulation modulated sensitivity to platinum in serous ovarian cancer cells in vitro. CONCLUSIONS: HtrA2 expression was a predictor for sensitivity to chemotherapy, and could be a candidate of molecular target in the treatment of high-grade serous ovarian cancers.

Overexpression of SMYD2 contributes to malignant outcome in gastric cancer.

BACKGROUND: SET and MYND domain-containing protein 2 (SMYD2) is a lysine methyltransferase for histone H3, p53 and Rb and inhibits their transactivation activities. In this study, we tested whether SMYD2 (1q42) acts as a cancer-promoting factor by being overexpressed in gastric cancer. METHODS: We analysed 7 gastric cancer cell lines and 147 primary tumor samples of gastric cancer, which were curatively resected in our hospital. RESULTS: SET and MYND domain-containing protein 2 was detected in these cell lines (five out of seven cell lines; 71.4%) and primary tumor samples (fifty-six out of one hundred and forty-seven cases; 38.1%). Knockdown of SMYD2 using specific small interfering RNA inhibited proliferation, migration and invasion of SMYD2-overexpressing cells in a TP53 mutation-independent manner. Overexpression of SMYD2 protein correlated with larger tumor size, more aggressive lymphatic invasion, deeper tumor invasion and higher rates of lymph node metastasis and recurrence. Patients with SMYD2-overexpressing tumours had a worse overall rate of survival than those with non-expressing tumours (P=0.0073, log-rank test) in an intensity and proportion score-dependent manner. Moreover, multivariate analysis demonstrated that SMYD2 was independently associated with worse outcome (P=0.0021, hazard ratio 4.25 (1.69-10.7)). CONCLUSIONS: These findings suggest that SMYD2 has a crucial role in tumor cell proliferation by its overexpression and highlight its usefulness as a prognostic factor and potential therapeutic target in gastric cancer.

Anti-huCD20 antibody therapy for antibody-mediated rejection of renal allografts in a mouse model.

We have reported that B6.CCR5(-/-) mice reject renal allografts with high serum donor-specific antibody (DSA) titers and marked C4d deposition in grafts, features consistent with antibody-mediated rejection (AMR). B6.huCD20/CCR5(-/-) mice, where human CD20 expression is restricted to B cells, rejected A/J renal allografts by day 26 posttransplant with DSA first detected in serum on day 5 posttransplant and increased thereafter. Recipient treatment with anti-huCD20 mAb prior to the transplant and weekly up to 7 weeks posttransplant promoted long-term allograft survival (>100 days) with low DSA titers. To investigate the effect of B cell depletion at the time serum DSA was first detected, recipients were treated with anti-huCD20 mAb on days 5, 8, and 12 posttransplant. This regimen significantly reduced DSA titers and graft inflammation on day 15 posttransplant and prolonged allograft survival >60 days. However, DSA returned to the titers observed in control treated recipients by day 30 posttransplant and histological analyses on day 60 posttransplant indicated severe interstitial fibrosis. These results indicate that anti-huCD20 mAb had the greatest effect as a prophylactic treatment and that the distinct kinetics of DSA responses accounts for acute renal allograft failure versus the development of fibrosis.

Pathological factors associated with omental metastases in endometrial cancer.

PURPOSE OF INVESTIGATION: This study aimed to assess the role of omentectomy in the surgical therapy of endometrial cancer. MATERI- ALS AND METHODS: A retrospective study was performed in 98 patients who were pathologically diagnosed with endometrial cancer and had initially undergone surgical therapy at the present institution. This study analyzed the relationship between omental metastasis and clinicopathological factors. RESULTS: Omental metastasis was detected in nine patients (9%). On univariate analysis, significant number of omental metastatic lesions were detected in few cases by positive peritoneal cytology, adnexal metastasis, gross dissemination, and lymphovascular space involvement. On multivariate analysis, adnexal metastasis were a significant risk factor. The sensitivity of the spe- cial histological type and the specificity of the macroscopic peritoneal dissemination and adnexal metastasis were all high. CONCLUSION: Omentectomy plays a significant role in determining the exact surgical staging in cases with non-endometrioid cancer, adnexal metas- tasis, and macroscopic peritoneal dissemination.

Effectiveness of third-line chemotherapy in recurrent ovarian cancer patients.

OBJECTIVE: Despite recent advances in the treatment of recurrent ovarian cancer, little evidence exists describing the benefit of third- line chemotherapy. The present authors previously reported that the treatment-free interval (TFI) after second-line chemotherapy may predict a survival benefit of third-line chemotherapy, however the length of TFI was uncertain due to limited cases. In this study, the authors evaluated the length of TFI, which is correlated with the effectiveness of third-line chemotherapy and a prognostic factor of third-line chemotherapy. MATERIALS AND METHODS: The authors reviewed the medical records of 85 women with recurrent ovarian cancer who received third-line chemotherapy after a paclitaxel/carboplatin (PC) regimen as first-line chemotherapy. RESULTS: The response rate [complete response (CR) + partial response (PR)] and clinical benefit rate [(CBR): CR + PR + stable disease (SD)] during the TFI after second-line chemotherapy for 0-3 months, 3-6 months, and 6-12 months and ≥ 12 months were 9.8%, 0%, 0%, 43.8% and 15.7%, 50%, 66.7%, and 93.8%, respectively. The median overall survival (OS) from the onset of third-line chemotherapy was longer for TFI ≥ 3 months than for TFI 0-3 months (795 days vs. 281 days, p < 0.001). Finally, according to univariate (HR = 0.256; p < 0.001) and multivariate (HR = 0.264; p < 0.001) analyses, TFI was the independent significant prognostic factor for OS. CONCLUSIONS: TFI less than three months after second-line chemotherapy may predict little survival benefit of third-line chemotherapy.

Activated PI3K/AKT and MAPK pathways are potential good prognostic markers in node-positive, triple-negative breast cancer.

BACKGROUND: Triple-negative breast cancer (TNBC) patients are a poor prognostic subgroup, and currently, there is no biomarker for targeted therapy. PATIENTS AND METHODS: Tissue samples were obtained from 75 TNBC patients with lymph-node metastases who had received adjuvant chemotherapy. We examined 11 biomarkers, including PIK3CA and AKT1mutation, with regard to event-free survival (EFS) and overall survival (OS) of patients. RESULTS: In the tumor tissues, phospho-AKT (pAKT) expression was significantly related to HER4 expression. Expression of each of these biomarkers was significantly related to longer EFS (P = 0.024 and 0.03, respectively). pERK expression was also a good prognostic factor regarding EFS and OS in TNBC (P = 0.002 and 0.006, respectively). We also identified a correlation between epidermal growth factor receptor positivity and insulin-like growth factor receptor type 1 positivity (P = 0.001). pERK and T-stage (1-3 versus >3) were independent good prognostic factors by multivariate analysis. CONCLUSIONS: We determined that tumors expressing pAKT or pERK are a good prognostic subtype in node-positive TNBC. Different targeted therapies may be necessary for TNBC that involves activation of PI3K/AKT or MAPK pathways.

Discontinuation of leisure time impact-loading exercise is related to reduction of a calcaneus quantitative ultrasound parameter in young adult Japanese females: a 3-year follow-up study.

UNLABELLED: A 3-year follow-up study on 334 young Japanese females enrolled in a university at the age of 18 years revealed that discontinuation of leisure time impact-loading exercises performed in junior high and/or high school was associated with increased risk of reduction in calcaneus osteo-sono assessment index (OSI). INTRODUCTION: Bone strength rapidly increases during puberty and reaches its peak by the end of adolescence. The aim of this study was to determine the lifestyle factors that influence the maintenance of calcaneus OSI in young adult females around the time when peak bone mass is attained. METHODS: Annual health checkups including OSI measurements, anthropometrics, lifestyle analysis, and blood examination were performed 4 times on 334 Japanese females enrolled in a university at the age of 18 years. According to the slope of OSI change during the 3-year follow-up, the subjects were grouped into two categories: OSI loss (the lowest tertile) and OSI gain/stable (the second and third tertiles). RESULTS: At the baseline assessment, the OSI loss group had higher OSI and height and an earlier menarche age than the OSI gain/stable group. Performing leisure time impact-loading exercise in junior high and/or high school but discontinuing it at university was associated with increased risk of OSI loss, independent of OSI, height and weight at the age of 18 years, weight change during follow-up, age of menarche, energy-adjusted nutrient intake, and alcohol drinking; the odds ratios were 4.1-4.9 compared with those performing impact-loading exercise at university. In particular, duration, frequency, and subjective intensity of impact-loading exercise during high school were positively associated with OSI loss. CONCLUSION: Discontinuation of leisure time impact-loading exercises performed during late adolescence is associated with an increased risk of OSI loss in young adult females during the 3-year follow-up period.

Uterine sutures at prior caesarean section and placenta accreta in subsequent pregnancy: a case-control study.

OBJECTIVE: To clarify the effects of uterine myometrial suture techniques at prior caesarean section on the incidence of pathologically diagnosed placenta accreta in placenta praevia with prior caesarean section (PPPC). DESIGN: Case-control study. SETTING: Eleven tertiary referral hospitals in central Japan. POPULATION: A total of 98 cases of placenta praevia, a history of one or more prior caesarean sections, and a history of uterine transverse incision and usage of only absorbable thread for myometrial sutures at the prior caesarean section. Exclusions were a history of myomectomy or Strassmann's operation. METHODS: Cases were grouped into a pathologically diagnosed placenta accreta group (38 cases) and a no accreta group (60 cases). Clinical characteristics including uterine suture methods at prior caesarean section were compared (single-layer versus double-layer closure; continuous versus interrupted sutures in the inner myometrial layer). MAIN OUTCOME MEASURE: The incidence of placenta accreta. RESULTS: No difference was found comparing single-layer with double-layer closure in the incidence of placenta accreta (37.1 versus 39.7%, P = 0.805); however, a significant difference was found comparing continuous with interrupted sutures (58.1 versus 29.9%, P = 0.008). Multivariable logistic regression analysis with stepwise selection for the eight factors meeting the criterion of P < 0.10 in univariate analysis was used, and four independent factors were selected, as follows: gravidity ≥ 3 (adjusted odds ratio, aOR, 3.4, 95% confidence interval, 95% CI, 0.99-11.6, P = 0.050); total praevia (versus non-total, aOR 18.4, 95% CI 3.2-107.0, P = 0.001); anterior/centre placenta (versus posterior, aOR 16.4, 95% CI 3.7-72.2, P < 0.001); and continuous sutures (versus interrupted, aOR 6.0, 95% CI 1.4-25.2, P = 0.015). CONCLUSIONS: In this limited study, a history of continuous sutures on the inner side of the uterine wall showed potential to influence the development of placenta accreta in PPPC patients.

Molecular detection of lymph node metastasis in breast cancer patients treated with preoperative systemic chemotherapy: a prospective multicentre trial using the one-step nucleic acid amplification assay.

BACKGROUND: For patients with breast cancer treated with preoperative chemotherapy, residual tumour burden in lymph nodes is the strongest prognostic factor. However, conventional pathological examination has limitations that hinder the accurate and reproducible measurement. The one-step nucleic acid amplification (OSNA) assay is a novel molecular method for detecting nodal metastasis. In this prospective multicentre trial, we assessed the performance of the OSNA assay in detecting nodal metastasis after chemotherapy. METHODS: In total, 302 lymph nodes from 80 breast cancer patients who underwent axillary dissection after chemotherapy were analysed. Each node was cut into two or four slices. One piece or alternate pieces were evaluated by pathology, and the other(s) were examined using the OSNA assay. The results of the two methods were compared. Stromal fibrosis, histiocytic aggregates, and degenerated cancer cells were regarded as chemotherapy-induced histological changes. RESULTS: The overall accuracy, sensitivity, and specificity of the OSNA assay compared with the reference pathology were 91.1%, 88.3%, and 91.7%, respectively. Of the 302 lymph nodes, 66 (21.9%) exhibited chemotherapy-induced histology. For these nodes, the accuracy, sensitivity, and specificity were 90.9%, 88.9%, and 93.3%, respectively. CONCLUSION: The OSNA assay can detect the residual tumour burden as accurately as conventional pathology, although chemotherapy-induced histological changes are present.

Frequent GNAS mutations in low-grade appendiceal mucinous neoplasms.

BACKGROUND: The molecular basis for the development of appendiceal mucinous tumours, which can be a cause of pseudomyxoma peritonei, remains largely unknown. METHODS: Thirty-five appendiceal mucinous neoplasms were analysed for GNAS and KRAS mutations. A functional analysis of mutant GNAS was performed using a colorectal cancer cell line. RESULTS: A mutational analysis identified activating GNAS mutations in 16 of 32 low-grade appendiceal mucinous neoplasms (LAMNs) but in none of three mucinous adenocarcinomas (MACs). KRAS mutations were found in 30 LAMNs and in all MACs. We additionally analysed a total of 186 extra-appendiceal mucinous tumours and found that GNAS mutations were highly prevalent in intraductal papillary mucinous tumours of the pancreas (88%) but were rare or absent in mucinous tumours of the colorectum, ovary, lung and breast (0-9%). The prevalence of KRAS mutations was quite variable among the tumours. The introduction of the mutant GNAS into a colorectal cancer cell line markedly induced MUC2 and MUC5AC expression, but did not promote cell growth either in vitro or in vivo. CONCLUSION: Activating GNAS mutations are a frequent and characteristic genetic abnormality of LAMN. Mutant GNAS might play a direct role in the prominent mucin production that is a hallmark of LAMN.

Overexpression of YWHAZ relates to tumor cell proliferation and malignant outcome of gastric carcinoma.

BACKGROUND: Several studies have demonstrated that YWHAZ (14-3-3ζ), included in the 14-3-3 family of proteins, has been implicated in the initiation and progression of cancers. We tested whether YWHAZ acted as a cancer-promoting gene through its activation/overexpression in gastric cancer (GC). METHODS: We analysed 7 GC cell lines and 141 primary tumours, which were curatively resected in our hospital between 2001 and 2003. RESULTS: Overexpression of the YWHAZ protein was frequently detected in GC cell lines (six out of seven lines, 85.7%) and primary tumour samples of GC (72 out of 141 cases, 51%), and significantly correlated with larger tumour size, venous and lymphatic invasion, deeper tumour depth, and higher pathological stage and recurrence rate. Patients with YWHAZ-overexpressing tumours had worse overall survival rates than those with non-expressing tumours in both intensity and proportion expression-dependent manner. YWHAZ positivity was independently associated with a worse outcome in multivariate analysis (P=0.0491, hazard ratio 2.3 (1.003-5.304)). Knockdown of YWHAZ expression using several specific siRNAs inhibited the proliferation, migration, and invasion of YWHAZ-overexpressing GC cells. Higher expression of the YWHAZ protein was significantly associated with the lower expression of miR-375 in primary GC tissues (P=0.0047). CONCLUSION: These findings suggest that YWHAZ has a pivotal role in tumour cell proliferation through its overexpression, and highlight its usefulness as a prognostic factor and potential therapeutic target in GC.

Diagnostic and prognostic significance of the alternatively spliced ACTN4 variant in high-grade neuroendocrine pulmonary tumours.

BACKGROUND: High-grade neuroendocrine tumours (HGNTs) of the lung manifest a wide spectrum of clinical behaviour, but no method for predicting their outcome has been established. MATERIALS AND METHODS: We newly established a monoclonal antibody specifically recognizing the product of the alternatively spliced ACTN4 transcript (namely, variant actinin-4), and used it to examine the expression of variant actinin-4 immunohistochemically in a total of 609 surgical specimens of various histological subtypes of lung cancer. RESULTS: Variant actinin-4 was expressed in 55% (96/176) of HGNTs, but in only 0.8% (3/378) of non-neuroendocrine (NE) lung cancers. The expression of variant actinin-4 was significantly associated with poorer overall survival in HGNT patients (P=0.00021, log-rank test). Multivariate analysis using the Cox proportional hazards model showed that the expression of variant actinin-4 was the most significant independent negative predictor of survival in HGNT patients (hazard ratio (HR), 2.15; P=0.00113) after the presence of lymph node metastasis (HR, 2.25; P=0.00023). CONCLUSIONS: The expression of variant actinin-4 is an independent prognostic factor for patients with HGNTs. This protein has a high affinity for filamentous actin polymers and likely promotes aggressive behaviour of cancer cells. The present clinical findings clearly support this notion.

Distinct outcome of stage I lung adenocarcinoma with ACTN4 cell motility gene amplification.

BACKGROUND: Even if detected at an early stage, a substantial number of lung cancers relapse after curative surgery. However, no method for distinguishing such tumors has yet been established. PATIENTS AND METHODS: The copy number of the actinin-4 (ACTN4) gene was determined by fluorescence in situ hybridization on tissue microarrays comprising 543 surgically resected adenocarcinomas of the lung. RESULTS: Amplification (an increase in the copy number by ≥ 2.0 fold) of the ACTN4 gene was detected in two of seven lung adenocarcinoma cell lines and 79 (15%) of 543 cases of pathological stage I-IV lung adenocarcinoma. Multivariate analysis revealed that ACTN4 gene amplification was the most significant independent factor associated with an extremely high risk of death (hazard ratio, 6.78; P = 9.48 × 10(-5), Cox regression analysis) among 290 patients with stage I lung adenocarcinoma. The prognostic significance of ACTN gene amplification was further validated in three independent cohorts totaling 1033 patients. CONCLUSIONS: Amplification of the ACTN4 gene defines a small but substantial subset of patients with stage I lung adenocarcinoma showing a distinct outcome. Such patients require intensive medical attention and might benefit from postoperative adjuvant chemotherapy.

Human epidermal growth factor receptor 2 protein overexpression and gene amplification in extramammary Paget disease.

BACKGROUND: Several recent studies have reported on the overexpression of human epidermal growth factor receptor (HER)2 in extramammary Paget disease (EMPD). However, there are only a few cases in which both overexpression and gene amplification of HER2 have been examined. OBJECTIVES: To evaluate the overexpression and gene amplification of HER2 using a standardized method with a large number of cases of EMPD. METHODS: Immunohistochemically, the overexpression of the HER2 protein was examined in 104 cases of EMPD, including 31 intraepithelial cases and 73 invasive cases (35 superficially invasive and 38 deeply invasive). When the HER2 protein was overexpressed or potentially overexpressed, further analysis of amplification of the gene encoding HER2, ERBB2, was undertaken using fluorescence in situ hybridization. RESULTS: The HER2 protein was overexpressed in 16 cases (15%) in total, and in 13 of 73 cases (18%) of invasive EMPD. The ERBB2 gene was amplified in all cases with a HER2 score of 3+. A HER2 score of 3+ or 2+, and ERBB2 amplification were significantly more frequent in the cases of deeply invasive EMPD than in intraepithelial/superficially invasive EMPD (24% vs. 6%/3%, P=0·012) and were correlated with a larger number of lymph-node metastases (P=0·047). Log-rank tests for survival curves showed that lymph-node metastasis and ERBB2 amplification were significant prognostic factors (P=0·0001 and P=0·043, respectively). However, by a multivariate analysis, only lymph-node status was a significant indicator of Paget-disease-specific survival (P=0·0001). CONCLUSIONS: A subset of EMPD, both intraepithelial and invasive, showed HER2 overexpression and gene amplification. These HER2 alterations were correlated with biologically aggressive EMPDs, i.e. those with deep invasion and lymph-node metastasis. Clinical trials of HER2-targeted therapy are awaited for improvement of the prognosis of patients with aggressive EMPD.

Antigen-specific human monoclonal antibodies from mice engineered with human Ig heavy and light chain YACs.

We describe a strategy for producing human monoclonal antibodies in mice by introducing large segments of the human heavy and kappa light chain loci contained on yeast artificial chromosomes into the mouse germline. Such mice produce a diverse repertoire of human heavy and light chains, and upon immunization with tetanus toxin have been used to derive antigen-specific, fully human monoclonal antibodies. Breeding such animals with mice engineered by gene targeting to be deficient in mouse immunoglobulin (Ig) production has led to a mouse strain in which high levels of antibodies are produced, mostly comprised of both human heavy and light chains. These strains should provide insight into the adoptive human antibody response and permit the development of fully human monoclonal antibodies with therapeutic potential.