Impact of deep learning on radiologists and radiology residents in detecting breast cancer on CT: a cross-vendor test study

AIM

To investigate the effect of deep learning on the diagnostic performance of radiologists and radiology residents in detecting breast cancers on computed tomography (CT).

MATERIALS AND METHODS

In this retrospective study, patients undergoing contrast-enhanced chest CT between January 2010 and December 2020 using equipment from two vendors were included. Patients with confirmed breast cancer were categorised as the training (n=201) and validation (n=26) group and the testing group (n=30) using processed CT images from either vendor. The trained deep-learning model was applied to test group patients with (30 females; mean age = 59.2 ± 15.8 years) and without (19 males, 21 females; mean age = 64 ± 15.9 years) breast cancer. Image-based diagnostic performance of the deep-learning model was evaluated with the area under the receiver operating characteristic curve (AUC). Two radiologists and three radiology residents were asked to detect malignant lesions by recording a four-point diagnostic confidence score before and after referring to the result from the deep-learning model, and their diagnostic performance was evaluated using jackknife alternative free-response receiver operating characteristic analysis by calculating the figure of merit (FOM).

RESULTS

The AUCs of the trained deep-learning model on the validation and test data were 0.976 and 0.967, respectively. After referencing with the result of the deep learning model, the FOMs of readers significantly improved (reader 1/2/3/4/5: from 0.933/0.962/0.883/0.944/0.867 to 0.958/0.968/0.917/0.947/0.900; p=0.038).

CONCLUSION

Deep learning can help radiologists and radiology residents detect breast cancer on CT.

Cellular plasticity of the bone marrow niche promotes hematopoietic stem cell regeneration

Hematopoietic stem cells (HSCs) regenerate after myeloablation, a procedure that adversely disrupts the bone marrow and drives leptin receptor-expressing cells, a key niche component, to differentiate extensively into adipocytes. Regeneration of the bone marrow niche is associated with the resolution of adipocytes, but the mechanisms remain poorly understood. Using Plin1-creER knock-in mice, we followed the fate of adipocytes in the regenerating niche in vivo. We found that bone marrow adipocytes were highly dynamic and dedifferentiated to leptin receptor-expressing cells during regeneration after myeloablation. Bone marrow adipocytes could give rise to osteolineage cells after skeletal injury. The cellular fate of steady-state bone marrow adipocytes was also plastic. Deletion of adipose triglyceride lipase (Atgl) from bone marrow stromal cells, including adipocytes, obstructed adipocyte dedifferentiation and led to severely compromised regeneration of HSCs as well as impaired B lymphopoiesis after myeloablation, but not in the steady state. Thus, the regeneration of HSCs and their niche depends on the cellular plasticity of bone marrow adipocytes.

Antihypertensive drug prescription trends for pregnant women with hypertension in acute hospitals in Japan

Hypertensive disorders of pregnancy cause maternal organ damage. Therefore, appropriate management with antihypertensive medication is required from the first trimester. We aimed to clarify the antihypertensive drug prescription trends in pregnant women with hypertension in Japan. The administrative data of pregnant outpatients aged 16-49 years who visited acute hospitals between 2013 and 2020 were included. The annual antihypertensive drug prescription trends were evaluated based on their prescription proportions. The most prescribed drug in 2020 was nifedipine, followed by methyldopa and amlodipine. The proportion of nifedipine prescriptions significantly increased from 33.5 to 40.8% during the study period, whereas that of methyldopa significantly decreased from 16.6 to 11.6%. There was no change in the prescription trend of amlodipine. Dihydropyridine calcium channel blockers were the most commonly prescribed drug for pregnant women with hypertension.

Therapeutic efficacy of intra-arterial docetaxel and nedaplatin infusion concomitant with radiotherapy for T4 maxillary sinus squamous cell carcinoma

The aim of this study was to evaluate the efficacy of intra-arterial chemoradiotherapy with docetaxel and nedaplatin for T4 maxillary sinus squamous cell carcinoma (MSSCC). Data were retrospectively analysed for 22 consecutive patients with T4 MSSCC who underwent intra-arterial chemoradiotherapy. Participants received intensity-modulated radiotherapy (70 Gy in 35 fractions) concomitantly with docetaxel (60 mg/m²) and nedaplatin (80 mg/m²) administered every 4 weeks for a total of three sessions. The median follow-up period was 49 months (range 12-91 months). T4a tumours were found in 16 patients (73%) and T4b tumours in six patients (27%). Cervical metastasis was found in nine patients (41%; five N2b, four N2c). The 5-year loco-regional control, disease-free survival, and overall survival rates for patients with T4a disease were 92.3%, 92.3%, and 90.3%, respectively, compared to 83.3% (P = 0.42), 66.7% (P = 0.07), and 83.3% (P = 0.46), respectively, for those with T4b disease. The 5-year loco-regional control, disease-free survival, and overall survival rates for patients with cervical lymph node metastasis were all 87.5% compared to 92.3% (P = 0.86), 84.6% (P = 0.69), and 92.3% (P = 0.93), respectively, for those without cervical metastasis. Intra-arterial chemoradiotherapy with docetaxel and nedaplatin may provide favourable loco-regional control and increased survival in T4 MSSCC.

Spatiotemporal dynamics of SETD5-containing NCoR-HDAC3 complex determines enhancer activation for adipogenesis

Enhancer activation is essential for cell-type specific gene expression during cellular differentiation, however, how enhancers transition from a hypoacetylated "primed" state to a hyperacetylated-active state is incompletely understood. Here, we show SET domain-containing 5 (SETD5) forms a complex with NCoR-HDAC3 co-repressor that prevents histone acetylation of enhancers for two master adipogenic regulatory genes Cebpa and Pparg early during adipogenesis. The loss of SETD5 from the complex is followed by enhancer hyperacetylation. SETD5 protein levels were transiently increased and rapidly degraded prior to enhancer activation providing a mechanism for the loss of SETD5 during the transition. We show that induction of the CDC20 co-activator of the ubiquitin ligase leads to APC/C mediated degradation of SETD5 during the transition and this operates as a molecular switch that facilitates adipogenesis.

Ubiquitination-dependent and -independent repression of target genes by SETDB1 reveal a context-dependent role for its methyltransferase activity during adipogenesis

The lysine methyltransferase SETDB1, an enzyme responsible for methylation of histone H3 at lysine 9, plays a key role in H3K9 tri-methylation-dependent silencing of endogenous retroviruses and developmental genes. Recent studies have shown that ubiquitination of human SETDB1 complements its catalytic activity and the silencing of endogenous retroviruses in human embryonic stem cells. However, it is not known whether SETDB1 ubiquitination is essential for its other major role in epigenetic silencing of developmental gene programs. We previously showed that SETDB1 contributes to the formation of H3K4/H3K9me3 bivalent chromatin domains that keep adipogenic Cebpa and Pparg genes in a poised state for activation and restricts the differentiation potential of pre-adipocytes. Here, we show that ubiquitin-resistant K885A mutant of SETDB1 represses adipogenic genes and inhibits pre-adipocyte differentiation similar to wild-type SETDB1. We show this was due to a compensation mechanism for H3K9me3 chromatin modifications on the Cebpa locus by other H3K9 methyltransferases Suv39H1 and Suv39H2. In contrast, the K885A mutant did not repress other SETDB1 target genes such as Tril and Gas6 suggesting SETDB1 represses its target genes by two mechanisms; one that requires its ubiquitination and another that still requires SETDB1 but not its enzyme activity.

Myofiber androgen receptor increases muscle strength mediated by a skeletal muscle splicing variant of Mylk4

Androgens have a robust effect on skeletal muscles to increase muscle mass and strength. The molecular mechanism of androgen/androgen receptor (AR) action on muscle strength is still not well known, especially for the regulation of sarcomeric genes. In this study, we generated androgen-induced hypertrophic model mice, myofiber-specific androgen receptor knockout (cARKO) mice supplemented with dihydrotestosterone (DHT). DHT treatment increased grip strength in control mice but not in cARKO mice. Transcriptome analysis by RNA-seq, using skeletal muscles obtained from control and cARKO mice treated with or without DHT, identified a fast-type muscle-specific novel splicing variant of Myosin light-chain kinase 4 (Mylk4) as a target of AR in skeletal muscles. Mylk4 knockout mice exhibited decreased maximum isometric torque of plantar flexion and passive stiffness of myofibers due to reduced phosphorylation of Myomesin 1 protein. This study suggests that androgen-induced skeletal muscle strength is mediated with Mylk4 and Myomesin 1 axis.

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DHT increases muscle strength through myofiber AR

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Myofiber AR increases a fast-type muscle-specific novel splicing variant of Mylk4

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MYLK4 regulates muscle strength and muscle stiffness

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MYLK4 induces phosphorylation of MYOM1

Adipsin promotes bone marrow adiposity by priming mesenchymal stem cells

Background

Marrow adipose tissue (MAT) has been shown to be vital for regulating metabolism and maintaining skeletal homeostasis in the bone marrow (BM) niche. As a reflection of BM remodeling, MAT is highly responsive to nutrient fluctuations, hormonal changes, and metabolic disturbances such as obesity and diabetes mellitus. Expansion of MAT has also been strongly associated with bone loss in mice and humans. However, the regulation of BM plasticity remains poorly understood, as does the mechanism that links changes in marrow adiposity with bone remodeling.

Methods

We studied deletion of Adipsin, and its downstream effector, C3, in C57BL/6 mice as well as the bone-protected PPARγ constitutive deacetylation 2KR mice to assess BM plasticity. The mice were challenged with thiazolidinedione treatment, calorie restriction, or aging to induce bone loss and MAT expansion. Analysis of bone mineral density and marrow adiposity was performed using a μCT scanner and by RNA analysis to assess adipocyte and osteoblast markers. For in vitro studies, primary bone marrow stromal cells were isolated and subjected to osteoblastogenic or adipogenic differentiation or chemical treatment followed by morphological and molecular analyses. Clinical data was obtained from samples of a previous clinical trial of fasting and high-calorie diet in healthy human volunteers.

Results

We show that Adipsin is the most upregulated adipokine during MAT expansion in mice and humans in a PPARγ acetylation-dependent manner. Genetic ablation of Adipsin in mice specifically inhibited MAT expansion but not peripheral adipose depots, and improved bone mass during calorie restriction, thiazolidinedione treatment, and aging. These effects were mediated through its downstream effector, complement component C3, to prime common progenitor cells toward adipogenesis rather than osteoblastogenesis through inhibiting Wnt/β-catenin signaling.

Conclusions

Adipsin promotes new adipocyte formation and affects skeletal remodeling in the BM niche. Our study reveals a novel mechanism whereby the BM sustains its own plasticity through paracrine and endocrine actions of a unique adipokine.

Funding

This work was supported by the National Institutes of Health T32DK007328 (NA), F31DK124926 (NA), R01DK121140 (JCL), R01AR068970 (BZ), R01AR071463 (BZ), R01DK112943 (LQ), R24DK092759 (CJR), and P01HL087123 (LQ).

A novel electron emission-based cell culture device promotes cell proliferation and differentiation of pre-osteoblastic MC3T3-E1 cells

In this report we demonstrate the effect of a novel electron emission-based cell culture device on the proliferation and differentiation of pre-osteoblastic MC3T3-E1 cells. Our device has an electron emission element that allows, for the first time, stable emission of electrons into an atmosphere. Atmospheric electrons react with gas molecules to generate radicals and negative ions, which induce a variety of biochemical reactions in the attached cell culture system. In this study, we demonstrated the effect of this new electron emission-based cell culture device on cell proliferation and differentiation using pre-osteoblastic MC3T3-E1 cells. Electron emission stimulation (EES) was applied directly to culture medium containing plated cells, after which the number of living cells, the mRNA levels of osteogenesis-related genes, and the alkaline phosphatase (ALP) activity were evaluated. The growth rate of EES-exposed cells increased by approximately 20% in comparison with unexposed control cells. We also found the mRNA levels of osteogenic specific genes such as collagen type I α-1, core-binding factor α-1, and osteocalcin to be up-regulated following EES. ALP activity, a marker for osteogenic activity, was significantly enhanced in EES-treated cells. Furthermore, reactive oxygen species generated by EES were measured to determine their effect on MC3T3-E1 cells. These results suggest that our new electron emission-based cell culture device, while providing a relatively weak stimulus in comparison with atmospheric plasma systems, promotes cell proliferation and differentiation. This system is expected to find application in regenerative medicine, specifically in relation to bone regeneration.

Nedaplatin as a Single-Agent Chemotherapy May Support Palliative Therapy for Patients with Adenoid Cystic Carcinoma: A Case Report

Adenoid cystic carcinoma (ACC) is a rare form of adenocarcinoma, which is a broad term describing any cancer that begins in the glandular tissues. It can be found in the head and neck. We report a patient with recurrent ACC arising from the submandibular gland, treated with 100 mg/m² nedaplatin every 4 weeks. Although our patient's lactate dehydrogenase levels, which is produced by ACC, showed a rising trend throughout the treatment, the level decreased for approximately 2 weeks immediately after administration of nedaplatin every 4 weeks. Thus, there is a possibility that the agent may be effective. Complications such as anorexia and nausea were observed, but they were tolerated and manageable. Nedaplatin may be considered as a supportive agent during palliative therapy for patients with ACC. More clinical trials regarding nedaplatin are necessary, as this study may indicate that a medical approach works well for ACC.

[A Case of Merkel Cell Carcinoma Complicated with Severe Thrombocytopenia Treated with Carboplatin/Etoposide Regimen after Surgery]

Thrombocytopenia is often caused by myelosuppression during chemotherapy. However, when platelet transfusions are required, pathological conditions such as idiopathic thrombocytopenic purpura(ITP)and thrombotic thrombocytopenic purpura( TTP)also occur. We report a case of Merkel cell carcinoma complicated with severe thrombocytopenia treated with carboplatin/etoposide regimen after surgery. The patient's platelet count did not increase in spite of platelet transfusions. However, the platelet count increased after steroid treatment was chosen under the diagnosis of ITP. Subsequent examinations revealed that the patient had HLA antibody, which caused the platelet transfusion refractoriness. When the platelet count does not increase in spite of platelet transfusions during chemotherapy, the possibility that the platelet transfusion refractoriness is due to the presence of HLA antibody should be considered.

Abstract P2-01-31: Validation of novel diagnostic kits using the semi-dry dot-blot method for detecting metastatic lymph nodes in breast cancer; distinguishing macrometastases and micrometastases

Background: The semi-dry dot-blot (SDB) method is a diagnostic procedure for detecting lymph node (LN) metastases. Metastases are confirmed by the presence of cytokeratin (CK) in lavage fluid of sectioned LNs that contain anti-pancytokeratin antibody, based on the theory that epithelial components such as CK are not found in normal LNs. We evaluated two novel SDB kits that use the newly developed anti-CK19 antibody for diagnosing LN metastases in breast cancer.

Methods: We obtained 159 LNs dissected from 93 breast cancer patients from July 2013 to December 2015 at Nagasaki University Hospital, including 38 dissected axillary LNs and 121 sentinel LNs, sliced at 2-mm intervals and washed with phosphate-buffered saline. The suspended cells in the lavage fluid of sliced LNs were centrifuged and lysed to extract protein. This extracted protein was used with a low-power and a high-power kit to diagnose LN metastasis. The washed LNs were blindly diagnosed by pathologists using hematoxylin and eosin (H&E) stain. Diagnoses based on the kit were compared with their H&E counterparts.

Results: Of the 159 LNs, 68 were assessed as positive and 91 as negative by permanent pathological examination with H&E. Sensitivity, specificity, and accuracy of the low-power kit for detecting LN metastases was 83.8%, 100%, and 93.1%, respectively. In 11 false-negative cases, there were nine micrometastases, producing a sensitivity of 96.4% for detecting macrometastases. Sensitivity, specificity, and accuracy of the high-power kit for detecting LN metastases was 92.6%, 92.3%, and 92.5%, respectively. Combining the low- and high-power kit results, sensitivity, specificity and accuracy for distinguishing macrometastases from micrometastases was 94.5%, 95.2%, and 95.0%, respectively. Diagnosis was achieved in approximately 20 min using the kits, at a cost of less than 25 USD.

Conclusions: The kits in our study were accurate, quick, and cost-effective in diagnosing LN metastases without the loss of LN tissue. The kits' ability to distinguish macrometastases from micrometastases was excellent, which is important, clinically.

Citation Format: Otsubo R, Hirakawa H, Oikawa M, Inamasu E, Baba M, Matsumoto M, Yano H, Kinoshita N, Abe K, Fukuoka J, Nagayasu T. Validation of novel diagnostic kits using the semi-dry dot-blot method for detecting metastatic lymph nodes in breast cancer; distinguishing macrometastases and micrometastases [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-01-31.

Postcomparison of [(18) F]-fluorodeoxyglucose uptake in the brain after short-term bright light exposure and no intervention

OBJECTIVE

Bright light therapy is widely used as the treatment of choice for seasonal affective disorder. Nonetheless, our understanding of the mechanisms of bright light is limited and it is important to investigate the mechanisms. The purpose of this study is to examine the hypothesis that bright light exposure may increase [(18) F]-fluorodeoxyglucose (FDG) uptake in olfactory bulb and/or hippocampus which may be associated neurogenesis in the human brain.

METHOD

A randomized controlled trial comparing 5-day bright light exposure + environmental light (bright light exposure group) with environmental light alone (no intervention group) was performed for 55 participants in a university hospital. The uptake of [(18) F]FDG in olfactory bulb and hippocampus using FDG positron emission tomography was compared between two groups.

RESULTS

There was a significant increase of uptake in both right and left olfactory bulb for bright light exposure group vs. no intervention group. After adjustment of log-transformed illuminance, there remained a significant increase of uptake in the right olfactory bulb.

CONCLUSION

The present findings suggest a possibility that 5-day bright light exposure may increase [(18) F]FDG in the right olfactory bulb of the human brain, suggesting a possibility of neurogenesis. Further studies are warranted to directly confirm this possibility.

A Predictive Model of Plasma Lamotrigine Levels

Introduction: Lamotrigine is one of several mood stabilizers and its effects for the treatment and prevention of depressive episodes, particularly in bipolar disorder, are generally accepted. Although the findings about a therapeutic window of lamotrigine are yet to be determined, it seems important to obtain information on individual pharmacokinetic peculiarities. This study was conducted to formulate the predictive model of plasma lamotrigine levels. Methods: Using the data of 47 patients whose lamotrigine levels, liver function, and renal function were measured, predictive models of lamotrigine levels were formulated by stepwise multiple regression analyses. The predictive power of the models was compared using another dataset of 25 patients. Results: Two models were created using stepwise multiple regression. The first model was: plasma lamotrigine level (μg/mL)=2.308+0.019×lamotrigine dose (mg/day). The second model was: plasma lamotrigine level (μg/mL)=0.08+0.024×lamotrigine dose (mg/day)+4.088×valproate combination (no=0, yes=1). The predictive power of the second model was better than that of the first model. Discussion: The present study proposes a prompt and relatively accurate equation to predict lamotrigine levels.

Abstract P3-01-18: Validation of a novel diagnostic kit using the semi-dry dot-blot method for detecting metastatic lymph nodes in breast cancer

Background: The semi-dry dot-blot (SDB) method is a diagnostic procedure for detecting lymph node (LN) metastases. The metastases are visualized by the presence of cytokeratin (CK) with lavage fluid of sectioned LNs by anti-pancytokeratin antibody, based on the theory that epithelial components such as CK are not found in normal LNs. We previously reported 93.3% sensitivity, 96.9% specificity, and 96.6% accuracy for this method in detecting metastasis in sentinel LNs, compared with permanent pathological diagnosis in breast cancer. In this study, we evaluated a novel kit that applies the SDB method using the newly developed anti-CK19 antibody for diagnosing LN metastases in breast cancer.

Methods: We obtained 141 LNs dissected from 81 breast cancer patients from July 2013 to April 2015 at Nagasaki University Hospital and the Japanese Red Cross Nagasaki Genbaku Hospital, including 33 dissected axillary LNs and 108 sentinel LNs, which were sliced at 2-mm intervals and washed with phosphate-buffered saline. The suspended cells in the lavage fluid of sliced LNs were centrifuged to collect the cell pellet and lysed with lysis buffer to extract protein. This extracted protein was used with the kit to diagnose LN metastasis. The washed LNs were blindly diagnosed by pathologists using hematoxylin and eosin (H&E) stain. Diagnoses based on the kit were compared with their H&E counterparts.

Results: Of the 141 LNs, 57 were assessed as positive and 84 as negative by permanent pathological examination with H&E. Use of the kit resulted in correct diagnoses in 46 of the 57 pathologically positive cases and all of pathologically negative cases. Sensitivity, specificity and accuracy of the kit in detecting LN metastases were 80.7% (95% confidence interval [95% CI]: 75.6–80.7%), 100% (95% CI: 96.5–100%), and 92.2% (95% CI: 88.1–92.2%), respectively. In 11 false-negative cases, there were 9 micrometastases; therefore, sensitivity was 95.5% (95% CI: 90.1–95.5%) in cases of macrometastases. Diagnosis was achieved in approximately 20 min using the kit, reducing the diagnostic time by half compared with the original SDB method. The cost of this kit was within 8 USD, and we are currently developing an improved kit for the detection of smaller metastases.

Conclusions: The kit in our study is accurate, quick, and cost-effective in diagnosing LN metastases without the loss of LN tissue. Its sensitivity in detecting macrometastases is excellent, which is important in clinical practice.

Citation Format: Otsubo R, Hirakawa H, Oikawa M, Shibata K, Tanaka A, Matsumoto M, Yano H, Nagayasu T. Validation of a novel diagnostic kit using the semi-dry dot-blot method for detecting metastatic lymph nodes in breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-01-18.

Lymph node density predicts lung metastases in oral squamous cell carcinoma

The association between lymph node density and survival free of lung metastases in oral squamous cell carcinoma (SCC), has not been investigated so far to our knowledge. Lymph node density ≧ 0.07 has been reported by a multicentre international study to be a significant predictor of shorter survival in patients with oral SCC who have invaded nodes. We investigated whether a lymph node density of ≧ 0.07 correlates with shorter overall survival, survival free of distant metastases, and survival free of lung metastases, in patients with oral SCC and invaded lymph nodes. Thirty-five patients with histologically-confirmed invaded lymph nodes werestudied. Their density was calculated as the ratio of the number of invaded lymph nodes:total number of nodes. A density of ≧ 0.07 correlated significantly with shorter overall survival (p<0.02), survival free of distant metastases (p<0.01), and survival free of lung metastases (p<0.01) on log rank testing. On testing by Cox's proportional hazards model of multivariate survival analysis with adjustment for the pathological stage (pstage IV/pstage III), and invaded surgical margins or extracapsular spread, or both, we found that lymph node density ≧ 0.07 was associated with significantly shorter survival (p<0.02). We conclude that lymph node density predicts lung metastases in patients with oral SCC.

A DPP-4 inhibitor suppresses fibrosis and inflammation on experimental autoimmune myocarditis in mice

Myocarditis is a critical inflammatory disorder which causes life-threatening conditions. No specific or effective treatment has been established. DPP-4 inhibitors have salutary effects not only on type 2 diabetes but also on certain cardiovascular diseases. However, the role of a DPP-4 inhibitor on myocarditis has not been investigated. To clarify the effects of a DPP-4 inhibitor on myocarditis, we used an experimental autoimmune myocarditis (EAM) model in Balb/c mice. EAM mice were assigned to the following groups: EAM mice group treated with a DPP-4 inhibitor (linagliptin) (n = 19) and those untreated (n = 22). Pathological analysis revealed that the myocardial fibrosis area ratio in the treated group was significantly lower than in the untreated group. RT-PCR analysis demonstrated that the levels of mRNA expression of IL-2, TNF-α, IL-1β and IL-6 were significantly lower in the treated group than in the untreated group. Lymphocyte proliferation assay showed that treatment with the DPP-4 inhibitor had no effect on antigen-induced spleen cell proliferation. Administration of the DPP-4 inhibitor remarkably suppressed cardiac fibrosis and reduced inflammatory cytokine gene expression in EAM mice. Thus, the agents present in DPP-4 inhibitors may be useful to treat and/or prevent clinical myocarditis.

Psychosocial factors associated with suicidal ideation in clinical patients with depression

BACKGROUND

Depression is a major risk factor for suicide, but few studies have examined psychosocial risk factors for suicide in clinical patients with depression. The purpose of this study was to investigate psychosocial factors which could be associated with suicidal ideation in clinical patients with depression including: sick-leave, help-seeking behavior, and reluctance to admit mental health problems.

METHODS

A multi-center cross-sectional survey using self-report questionnaire was conducted at 54 outpatient psychiatric clinics in Tokyo in 2012. Adult outpatients who were diagnosed by psychiatrists as mood disorders (F30-F39) in the International Classification of Diseases-10 (ICD-10) were included in the study. Those who met the criteria for current hypomanic or manic episode were excluded from the study.

RESULTS

A total of 189 patients with depression participated in the survey. Multivariable logistic regression analysis showed that taking sick-leave and having sought help from family were associated with decreased odds of current suicidal ideation. Moderate or more severe depression was associated with increased odds of suicidal ideation, and reluctance to admit own mental health problem tended to increase odds of suicidal ideation.

LIMITATIONS

Living status and suicidal ideation before consultation with psychiatrist were not investigated. Severity of suicidal ideation and comorbid psychiatric disorders were not assessed.

CONCLUSIONS

Importance of treatment of more severe depression for suicide prevention was confirmed. Industrial health staffs should consider the possibility of positive effect of taking sick-leave when they see employees with depression. Promoting help-seeking for family and reducing stigma of mental illness may be effective for suicide prevention.

Intratumoral concentration of estrogens and clinicopathological changes in ductal carcinoma in situ following aromatase inhibitor letrozole treatment

Background:

Estrogens have important roles in ductal carcinoma in situ (DCIS) of the breast. However, the significance of presurgical aromatase inhibitor treatment remains unclear. Therefore, we examined intratumoral concentration of estrogens and changes of clinicopathological factors in DCIS after letrozole treatment.

Methods:

Ten cases of postmenopausal oestrogen receptor (ER)-positive DCIS were examined. They received oral letrozole before the surgery, and the tumour size was evaluated by ultrasonography. Surgical specimens and corresponding biopsy samples were used for immunohistochemistry. Snap-frozen specimens were also available in a subset of cases, and used for hormone assays and microarray analysis.

Results:

Intratumoral oestrogen levels were significantly lower in DCIS treated with letrozole compared with that in those without the therapy. A great majority of oestrogen-induced genes showed low expression levels in DCIS treated with letrozole by microarray analysis. Moreover, letrozole treatment reduced the greatest dimension of DCIS, and significantly decreased Ki-67 and progesterone receptor immunoreactivity in DCIS tissues.

Conclusion:

These results suggest that estrogens are mainly produced by aromatase in DCIS tissues, and aromatase inhibitors potently inhibit oestrogen actions in postmenopausal ER-positive DCIS through rapid deprivation of intratumoral estrogens.

Abstract P1-01-27: Novel diagnostic procedure of metastasis to the sentinel lymph node of breast cancer using a semi-dry dot-blot method

Background: Sentinel lymph node (SLN) biopsy is a common surgical procedure. However, novel diagnostic modalities are required because of a shortage of pathology specialists in Japan and discordance between the intraoperative and final pathological diagnosis of SLN metastasis. Efficient methods that use molecular markers for detecting SLN metastasis, such as one-step nucleic acid amplification, are commercially available, but special equipment (e.g., thermal cycler) is costly and the problem of false-negatives for CK19 non-expressing cells remains unresolved. Recently, we developed an easy, quick and cost-effective method for detection of cancer cells in lymph nodes by applying dot-blot analysis technology, called the “semi-dry dot-blot method (SDB method)”. The SDB method visualizes the presence of cancer cells with washing of sectioned lymph nodes by anti-pancytokeratin antibody (AE1/AE3) and chromogen on a dot-blot membrane. This method can detect 0.01 mg/mL protein extracted from cancer tissue and 20 suspension cells (MCF-7) in approximately 20 minutes. The current study evaluated the efficacy of our SDB method in the diagnosis of SLN metastasis in breast cancer.

Methods: (I) One hundred eighty dissected lymph nodes from 29 cases, including breast, lung, gastric and colorectal cancer, were analyzed. Each lymph node was sliced at the maximum diameter and washed by phosphate-buffered saline (PBS), and this lavage fluid (PBS) was used for diagnosis of LN metastasis by the SDB method, and washed lymph node was sent to pathological section for pathological diagnosis. The sensitivity, specificity and accuracy of the SDB method were determined to compare with the final pathology report.

(II) A multicenter prospective clinical trial was conducted, where 132 SLN samples from 78 cases of clinically node-negative breast cancer were analyzed. Each SLN was sliced at 2-mm intervals and washed by PBS. Lavage fluid of sliced SLNs was used for the diagnosis of SLN metastasis by the SDB method in a blinded manner. The sensitivity, specificity, accuracy and the time required for the SDB method were determined and compared with the intra-operative pathology report.

Results: (I) Lymph node metastasis was detected in 35 lymph nodes (19.4%). Comparison of the results between the final pathology and the SDB method showed complete concordance (accuracy: 100%).

(II) Of the 132 lymph nodes eligible for analysis, 13 (10.0%) were assessed as positive and 114 as negative by the SDB method and intra-operative pathological examination, with an accuracy of 96.2%. All pathologically positive nodes, which included one micro metastasis, were also detected by the SDB method; (sensitivity: 100%). One hundred fourteen of the 119 pathologically negative nodes were assessed as negative with the SDB method (specificity: 95.8%). The mean required times of 16 cases for intra-operative pathological diagnosis and simultaneous SDB method were 43.5 and 42.2 minutes, respectively.

Conclusions: The SDB method is simple, fast, accurate and cost-effective for the intra-operative diagnosis of SLN metastasis. Because there is no loss of lymph node tissue, the SDB method and pathological investigation can be performed simultaneously.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-01-27.

Effect of cervical sympathetic trunk transection on renal sympathetic nerve activity in rats

Stellate ganglion blockade (SGB) with a local anesthetic increases muscle sympathetic nerve activity in the tibial nerve in humans. However, whether this sympathetic excitation in the tibial nerve is due to a sympathetic blockade in the neck itself, or due to infiltration of a local anesthetic to adjacent nerves including the vagus nerve remains unknown. To rule out one mechanism, we examined the effects of cervical sympathetic trunk transection on renal sympathetic nerve activity (RSNA) in anesthetized rats. Seven rats were anesthetized with intraperitoneal urethane. RSNA together with arterial blood pressure and heart rate were recorded for 15 min before and 30 min after left cervical sympathetic trunk transection. The baroreceptor unloading RSNA obtained by decreasing arterial blood pressure with administration of sodium nitroprusside was also measured. Left cervical sympathetic trunk transection did not have any significant effects on RSNA, baroreceptor unloading RSNA, arterial blood pressure, and heart rate. These data suggest that there was no compensatory increase in RSNA when cervical sympathetic trunk was transected and that the increase in sympathetic nerve activity in the tibial nerve during SGB in humans may result from infiltration of a local anesthetic to adjacent nerves rather than a sympathetic blockade in the neck itself.

Morphological changes in the rat carotid body 1, 2, 4, and 8 weeks after the termination of chronically hypocapnic hypoxia

Morphological changes in the rat carotid bodies 1, 2, 4, and 8 weeks after the termination of chronically hypocapnic hypoxia (10% O2 for 8 weeks) were examined by means of morphometry and immunohistochemistry. The rat carotid bodies after 8 weeks of hypoxic exposure were enlarged several fold with vascular expansion. The carotid bodies 1 and 2 weeks after the termination of 8 weeks of hypoxic exposure were diminished in size, although their diameter remained larger than the normoxic controls. The expanded vasculature in chronically hypoxic carotid bodies returned to the normoxic control state. In the carotid bodies 1 week after the termination of chronic hypoxia, the density of NPY fibers was remarkably increased and that of VIP fibers was dramatically decreased in comparison with the density in chronically hypoxic carotid bodies. In the carotid bodies 2 and 4 weeks after the termination of hypoxia, the density of SP and CGRP fibers was gradually increased. In the carotid bodies 8 weeks after the termination of hypoxia, the appearance of the carotid body returned to a nearly normoxic state, and the density of SP, CGRP, VIP, and NPY fibers also recovered to that of normoxic controls. These results suggest that the morphological changes in the recovering carotid bodies start at a relatively early period after the termination of chronic hypoxia, and a part of these processes may be under the control of peptidergic innervation.

Immunohistochemical collagen analysis of the most superficial layer in adult articular cartilage

We investigated immunohistochemically the collagen type of the most superficial layer in 10 normal adult human articular cartilage specimens obtained from eight femoral heads and one each of the femoral condyle and the talus using routine light microscopy and polarizing microscopy. A membrane-like structure with strong bire-fringence covering the articular surface was observed under polarizing microscopy in each specimen. This structure was stained with anti-type I and anti-type III collagen antibodies but not with anti-type II collagen antibody. This immunohistochemical finding was identical to that in synovial tissue. The results of this study confirm that the most superficial layer of adult normal articular cartilage consists not of type II collagen but of types I and III, and that this layer is absolutely independent from its deeper layer.

Differences in catecholamine metabolism and behaviour in neonatal broiler and layer chicks

1. To clarify the difference in behavioural activities and catecholamine metabolism between layer and broiler-type chicks two experiments were conducted. 2. In experiment 1, 1-d-old male layer and broiler chicks were placed in an open-field area and their responses were investigated for 10 min. The responses of the two strains were remarkably different, with broilers being less active than layers. Vocalisations rapidly decreased in broilers whereas those of layers remained elevated during the 10 min. 3. In experiment 2, 1-d-old chicks of both strains were killed and brain catecholamine concentrations were determined in three parts of the brain: telencephalon, optic lobe and brain stem. 4. In the whole brain, dopamine (DA) and dihydroxyphenylacetic acid (DOPAC) were significantly higher in broilers. However, the values for norepinephrine (NE), epinephrine (E) and 4-hydroxy-3-methoxyphenylacetic acid (HVA) were similar between strains. The ratios of metabolite/precursor were also calculated: HVA/DOPAC was higher in layers, while NE/DA, E/NE and DOPAC/DA were not significantly different between strains. 5. These results suggest that behavioural activities differ greatly, while there are some differences in catecholamine metabolism between the two strains.

De novo uterine sarcoma with good response to neo-adjuvant chemotherapy

We report here the extremely rare case of a 28-year-old woman with advanced stage uterine sarcoma arising soon after a cesarean section. She underwent an abdominal cesarean section because of a breech presentation. At the time of the procedure, there were no abnormal findings such as leiomyoma of the uterus in the abdominal cavity. One year later, she was referred to our hospital because of a large abdominal tumor. Transabdominal power Doppler ultrasonography and magnetic resonance imaging (MRI) showed a large hypervascular tumor in the abdominal cavity. Her serum levels, for the two tumor markers carbohydrate antigen CA125 and LDH, were elevated, at 219 U/ml (< 35 U/ml) and 862 IU/l (115 U/ml-217 U/ml), respectively. On the basis of a diagnosis of malignant tumor of gynecological origin, exploratory laparotomy was performed, and through biopsy, the tumor was found to be advanced undifferentiated uterine sarcoma. She exhibited a good response to neoadjuvant chemotherapy consisting of cisplatin, epirubicin, and dimethyltriazenoimidazole carboxamide (DTIC) every 28 days, which was successfully followed by a hysterectomy.

Effect of Garcinia cambogia extract on serum leptin and insulin in mice

In this study we examined the effects of 3.3% Garcinia cambogia extract on 10% sucrose loading in mice for 4 weeks. Treatment was found to have no effect on body weight, fat pad weight or serum glucose level. On the other hand, serum total cholesterol, triglycerides, NEFA were observed. Levels of serum insulin and leptin, as well as the leptin/WAT ratio, were lower in the treated mice than in the control. These findings suggested that G. cambogia extract efficiently improved glucose metabolism and displayed leptin-like activity.

Peptidergic innervation in the rat carotid body after 2, 4, and 8 weeks of hypocapnic hypoxic exposure

The distribution and abundance of neuropeptide-containing nerve fibers were examined in the carotid bodies of rats exposed to hypocapnic hypoxia (10% O2 in N2) for 2, 4, and 8 weeks. The carotid bodies after 2, 4, and 8 weeks of hypoxic exposure were enlarged by 1.2-1.5 times in the short axis, and 1.3-1.7 times in the long axis in comparison with the normoxic control ones. The enlarged carotid bodies contained a number of expanded blood vessels. Mean density per unit area (10(4) microm2) of substance P (SP) and calcitonin gene-related peptide (CGRP) immunoreactive fibers was transiently high in the carotid bodies after 4 weeks of hypoxic exposure, and decreased significantly to nearly or under 50% after 8 weeks of hypoxic exposure. Density of vasoactive intestinal polypeptide (VIP) immunoreactive fibers increased significantly in all periods of hypoxic exposure observed, and was especially high in the carotid bodies after 4 weeks of hypoxic exposure. Density of neuropeptide Y immunoreactive fibers was unchanged in the carotid bodies during hypoxic exposure. These characteristic changes in the density of SP, CGRP, and VIP fibers in the carotid bodies after 4 weeks of hypoxic exposure suggest that the role of these neuropeptide-containing fibers may be different in the carotid bodies after each of three periods of hypoxic exposure, and that the peptidergic innervation after 8 weeks of hypoxic exposure may show an acclimatizing state.

Middle ear instillation of gentamicin and streptomycin in chinchillas: electrophysiological appraisal of selective ototoxicity

The purpose of this study was to investigate selective vestibular ototoxicity of gentamicin and streptomycin in the chinchilla model. In total, 10 chinchillas underwent left middle ear instillation of one of three agents: gentamicin, streptomycin and saline. Electrophysiological data (otoacoustic emissions (OAEs), auditory brainstem evoked response (ABRs), and ice-water electronystagmography were recorded before and after instillation. Animals were sacrificed for temporal bone studies using scanning electron microscopy. Morphological changes in the cochlear and vestibular neuroepithelia were correlated with electrophysiological changes. Widespread ipsilateral cochlear and vestibular neuroepithelial injuries were observed and correlated with loss of OAEs, ABRs and ice-water caloric response. This study provides no evidence of selective vestibular ototoxicity of gentamicin or streptomycin. Morphological damage correlates with, but precedes loss of electrophysiological parameters. Chinchillas, like other small mammals, may not be an ideal model for the study of human ototoxicity.

Electrical properties of chemoreceptor elements in the carotid body

The electrical properties of chemoreceptor afferent nerve fibers and glomus cells and the behavior of cytosolic Ca(2+) in glomus cells are reviewed. While this has not been confirmed, spontaneously depolarizing potentials (SDPs) recorded in a chemoreceptor afferent terminal may be the postsynaptic expression of presynaptic events. Glomus cells, which are presynaptic elements, either depolarized or hyperpolarized in response to natural and chemical stimulation. After-hyperpolarization following an initial depolarization and after-depolarization following an initial hyperpolarization were often seen. When a glomus cell depolarizes, voltage noise increases despite a decrease in input resistance in both intact and denervated carotid bodies. The voltage noise may be "receptor noise" generated in the glomus cell itself. The electrical properties of glomus cells change in the denervated carotid body, which suggests that the chemoreceptor afferent nerve exerts some trophic effect(s) on glomus cells. Hypoxia either increases or decreases cytosolic Ca(2+), while ACh or NaCN induces either an increase or no change in cytosolic Ca(2+) in glomus cells. There are at least two possible explanations for voltage changes in glomus cells: a chemical stimulus first depolarizes the glomus cell and induces Ca(2+) influx to release chemical substances, or a chemical stimulus induces an increase in [Ca(2+)](i) and then hyperpolarizes the glomus cell via potassium influx.

Changes in the peptidergic innervation in the carotid body of rats chronically exposed to hypercapnic hypoxia: an effect of arterial CO2 tension

The abundance of neuropeptide Y (NPY)-, vasoactive intestinal polypeptide (VIP)-, substance P (SP)-, and calcitonin gene-related peptide (CGRP)-immunoreactive nerve fibers in the carotid body was examined in chronically hypercapnic hypoxic rats (10% O2 and 6-7% CO2 for 3 months), and the distribution and abundance of these four peptidergic fibers were compared with those of previously reported hypocapnic- and isocapnic hypoxic carotid bodies to evaluate the effect of arterial CO2 tension. The vasculature in the carotid body of chronically hypercapnic hypoxic rats was found to be enlarged in comparison with that of normoxic control rats, but the rate of vascular enlargement was smaller than that in the previously reported hypocapnic- and isocapnic hypoxic carotid bodies. In the chronically hypercapnic hypoxic carotid body, the density per unit area of parenchymal NPY fibers was significantly increased, and that of VIP fibers was unchanged, although the density of NPY and VIP fibers in the previously reportetd chronically hypocapnic and isocapnic hypoxic carotid bodies was opposite to that in hypercapnic hypoxia as observed in this study. The density of SP and CGRP fibers was decreased. These results along with previous reports suggest that different levels of arterial CO2 tension change the peptidergic innervation in the carotid body during chronically hypoxic exposure, and altered peptidergic innervation of the chronically hypercapnic hypoxic carotid body is one feature of hypoxic adaptation.

A case of transverse testicular ectopia with müllerian duct remnant

Transverse testicular ectopia (TTE) associated with persistent müllerian duct (PMD) is a rare genitourinary anomaly. The authors report a case with a review of the literature and stress the importance of careful physical examination and ultrasonography in making a correct preoperative diagnosis of TTE. One should be careful not to miss the tiny PMD structure at the operation. Transseptal orchidopexy is the surgical treatment of choice.

Electrophoretic characterization of heat-stable squamous cell carcinoma antigen

The aim of this study was to investigate the heat stability of squamous cell carcinoma (SCC) antigen, a tumor-associated serine proteinase inhibitor (serpin), in tumor tissue extract by electrophoretic methods. After heat treatment at 70 degrees C for 2 h, the tumor tissue extract showed a single main protein band of 45 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) which reacted with a monoclonal antibody specific for SCC antigen. The heat-stable SCC antigen was separated by two-dimensional electrophoresis (2-DE) into four spots with pI 6.4-5.9 and Mr 44500-45 000 of SCC antigen-1. Furthermore, the SCC antigen-1 still showed its inhibitory activity against a cysteine proteinase, papain, by gelatin zymography. These results suggest that heat treatment of protein sample at 70 degrees C for 2 h may be a useful method for a partial purification of SCC antigen-1 which can inhibit lysosomal cysteine proteinases such as cathepsin L, S, and K.

[Follow-up survey of dioxins in the blood of Yusho patients (in 1998-1999)]

Follow-up survey of the blood concentration of PCDDs, PCDFs and non-ortho-chlorine substituted PCBs in Yusho patients is very important for their health control. We determined the blood concentration of these dioxin isomers in 119 blood samples collected in 1998 and 1999 using by a high-resolution gas chromatograph/high-resolution mass spectrometry (HRGC/HRMS). Thirty years had passed since the Yusho occurrence, and the total blood concentrations of PCDFs in the blood of Yusho patients were still as high as ever, except the patients with the PCB pattern C. Among the different groups of PCB patterns, the concentration of 2,3,4,7,8-PeCDF, 1,2,3,4,7,8-HxCDF and 1,2,3,6,7,8-HxCDF showed significant differences, excluding the group BC because of the small number of cases. The findings indicate that these isomers are not decomposed in human body since they had highly contaminated the causal rice oil at the onset. In typical Yusho patients (Group A of PCB pattern), the mean TEQ concentrations of PCDDs, PCDFs and non-ortho-chlorine substituted PCBs in the blood collected in 1998 were 21, 206, and 14 pg-TEQ/g lipid, respectively, and in 1999, 30, 308 and 14 pg-TEQ/g lipid, respectively. The toxic contribution rate of PCDFs TEQ was still at high levels for total TEQ in both years. The patients of the group C, however, the mean blood levels of the dioxins TEQ in 1998 and 1999 did not differ from those of the normal controls determined in 1996 although some patients in this group showed a high toxic contribution rate of PCDFs TEQ for total TEQ. We will try the PCB isomer specific analysis of the Yusho patients blood, and will investigate the difference from normal controls blood.

Comparison between "Yusho" patients and healthy Japanese in contamination level of dioxins and related chemicals and frequency of sister chromatid exchanges

Highly toxic organochlorine chemicals such as polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and coplanar polychlorinated biphenyls (CoPCBs) were determined in the peripheral blood and sebum from the face of 16 "Yusho" patients of about 27 yr after the outbreak of Yusho accident, and 39 healthy Japanese people. The mean total toxic equivalent (TEQ) levels of PCDDs, PCDFs and CoPCBs in the blood were still about seven times higher in Yusho patients than in healthy Japanese at the age of 45 yr and more. The sebum excretion of these chemicals seemed proportional to their blood levels in Yusho patients. These toxic chemicals, however, did not enhance frequencies of sister chromatid exchanges (SCEs) in the control and 7,8-benzoflavone (ANF) treated cultures in Yusho patients. Hence, no significant difference was observed in the mean SCE rates between the Yusho patients and general Japanese people of more than 45 yr of age. In this study, the number of Yusho patients examined is limited, so further large-scale investigations are needed to get more conclusive results concerning the genotoxic potency such as SCE induction.