Gastric Pathology Image Classification Using Stepwise Fine-Tuning for Deep Neural Networks

Deep learning using convolutional neural networks (CNNs) is a distinguished tool for many image classification tasks. Due to its outstanding robustness and generalization, it is also expected to play a key role to facilitate advanced computer-aided diagnosis (CAD) for pathology images. However, the shortage of well-annotated pathology image data for training deep neural networks has become a major issue at present because of the high-cost annotation upon pathologist's professional observation. Faced with this problem, transfer learning techniques are generally used to reinforcing the capacity of deep neural networks. In order to further boost the performance of the state-of-the-art deep neural networks and alleviate insufficiency of well-annotated data, this paper presents a novel stepwise fine-tuning-based deep learning scheme for gastric pathology image classification and establishes a new type of target-correlative intermediate datasets. Our proposed scheme is deemed capable of making the deep neural network imitating the pathologist's perception manner and of acquiring pathology-related knowledge in advance, but with very limited extra cost in data annotation. The experiments are conducted with both well-annotated gastric pathology data and the proposed target-correlative intermediate data on several state-of-the-art deep neural networks. The results congruously demonstrate the feasibility and superiority of our proposed scheme for boosting the classification performance.

External validation of two web-based postoperative nomograms predicting the probability of early biochemical recurrence after radical prostatectomy: a retrospective cohort study

The present study aimed to validate and compare the predictive accuracies of the Memorial Sloan Kettering Cancer Center (MSKCC) and Johns Hopkins University (JHU) web-based postoperative nomograms for predicting early biochemical recurrence (BCR) after radical prostatectomy (RP) and to analyze clinicopathological factors to predict early BCR after RP using our dataset. The c-index was 0.72 (95% confidence (CI): 0.61-0.83) for the MSKCC nomogram and 0.71 (95% CI: 0.61-0.81) for the and JHU nomogram, demonstrating fair performance in the Japanese population. Furthermore, we statistically analyzed our 174 patients to elucidate prognostic factors for early BCR within 2 years. Lymphovascular invasion (LVI) including lymphatic vessel invasion (ly) was a significant predictor of early BCR in addition to common variables (pT stage, extraprostatic extension, positive surgical margin and seminal vesicle invasion). LVI, particularly ly, may provide a good predictor of early BCR after RP and improve the accuracy of the nomograms.

Susceptibilities of epicardial and subcutaneous fat tissue for browning-gene expression and diet-induced volume reduction are different

The upregulation of brown or brown-like beige adipocytes is a potential strategy for the prevention or treatment of diabetes and coronary artery diseases in obese patients. Epicardial adipose tissue (EAT) differs significantly from subcutaneous fat tissue (SAT) in metabolic properties. To investigate properties of EAT further, thermogenesis gene expression was investigated in human autopsy and murine samples, and adipocytes differentiated from EAT mesenchymal cells. Subsequently, analyzed EAT volume alterations were observed to be associated with weight reduction in obese patients by imaging. Gene expression analyses of autopsy samples revealed that UCP‑1 mRNA levels in EAT were significantly increased compared with SAT, and β3‑adrenergic receptor (AR) levels tended to be increased; this finding was verified in comparing EAT with SAT in mice. Browning stimulation of human EAT‑derived MCs increased uncoupling protein‑1 and β3‑AR levels by 3.2 fold‑ and 12.6‑fold compared with SAT‑derived MCs, respectively. Subsequent imaging for EAT volume measurement using multi‑detector computed tomography in 10 obese patients revealed that mean EAT volumes did not significantly decrease following weight loss therapy. The EAT volume alterations were not correlated with weight changes, whereas positive correlations were observed in SAT and visceral adipose tissue. Therefore, the studies in man and mouse on EAT properties demonstrated that susceptibilities of EAT and SAT for browning‑gene expression and diet‑induced volume reduction were grossly different. The data suggest a potential association of EAT with local thermogenetic and metabolic homeostasis in cardiac and/or cardiovascular cells, in conjunction with systemic energy metabolism.

Heregulin-induced cell migration is promoted by aryl hydrocarbon receptor in HER2-overexpressing breast cancer cells

HER2 overexpression accounts for approximately 15-20% of all breast cancers. We have shown that HER2 overexpression leads to elevated expression of the aryl hydrocarbon receptor (AhR) in breast cancer cells. In this study, firstly, we showed that AhR expression was up-regulated by treatment with the HER3 ligand heregulin (HRG) in HER2-overexpressing breast cancer cell lines. Induction of AhR was mediated by transcriptional activation of the region of AhR promoter corresponding to - 190 to - 100 bp. In addition, HRG treatment elicited nuclear translocation of AhR. To investigate the role of AhR in HRG-HER2/HER3 signaling in HER2-overexpressing cells, we established AhR knockout (KO) HER2-overexpressing cells to perform wound-healing assays. HRG-induced cell migration was markedly attenuated by AhR KO. HRG-induced cell migration was associated with increased expression of the inflammatory cytokines interleukin (IL)-6 and IL-8 in wild type cells, but not in AhR KO cells. These results elucidate that AhR is an important factor for the malignancy in HER2 overexpressing breast cancers.

Syndrome of Inappropriate Antidiuretic Hormone Secretion in a Patient with Mucosa-associated Lymphoid Tissue Lymphoma

Syndrome of inappropriate antidiuretic hormone secretion (SIADH) may develop in association with several malignancies. However, as an immunohistochemical analysis is not performed in the majority cases, its true cause is often uncertain. We herein report a case of SIADH following chemotherapy due to tumor-derived ADH production in a patient with mucosa-associated lymphoid tissue (MALT) lymphoma. A retrospective immunohistochemical analysis demonstrated ADH expression by lymphoma cells. These findings highlight the importance of using an immunohistochemical analysis to determine ADH production by tumor cells in patients with SIADH. Such analyses play an important role in elucidating the pathogenesis of SIADH and determining the most appropriate treatment.

Severely impaired activity of lipoprotein lipase Arg243His is partially ameliorated by emulsifying phospholipids in in vitro triolein hydrolysis analysis

Background We investigated the in vitro effects of various phospholipids as emulsifiers on the hydrolysing activities of lipoprotein lipase (LPL) Arg243His against triolein as substrate. LPL Arg243His, identified in a patient with hyperchylomicronaemia, displays severely diminished activity for triolein when emulsified with Triton X-100. Methods Lipolytic activities of plasma obtained by heparin injection from a homozygous patient with LPL Arg243His were analysed using triolein emulsified with phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS), phosphatidylinositol (PI), lysophosphatidylcholine (LPC), or Triton X-100 as substrates. Results The hydrolysing activities of the patient's plasma for triolein emulsified with PC, PE, PS, PI, LPC and Triton X-100 were 9.22 ± 1.06  μmol/ml/h/ngLPL, 2.94 ± 1.60  μmol/ml/h/ng LPL, 3.72 ± 1.63  μmol/ml/h/ng LPL, 3.40 ± 1.20  μmol/ml/h/ngLPL, 3.72 ± 1.96  μmol/ml/h/ngLPL and 7.80 ± 4.48  μmol/ml/h/ng LPL, respectively. Thus, the specific activities of the patient's LPL determined with triolein emulsified with PC were significantly higher than those with PE, PS, PI or LPC as emulsifiers. Relative to the activities of normal plasma measured with PC, PE, PS, PI and LPC as emulsifiers, the mutant's activities were 49.1 ± 5.2%, 44.1 ± 5.7%, 31.7 ± 12.6%, 19.2 ± 6.9% and 23.8 ± 11.3%, respectively. Using PC, PE, PS, PI and LPC as emulsifiers, the mutant's activities for triolein-lipolysis relative to normal were significantly increased in comparison to the relative activity measured with the classical emulsifier, Triton X-100 (12.9 ± 6.7%). Conclusions Impaired triolein hydrolysis by LPL Arg243His was partially ameliorated by triolein emulsification with phospholipids. The in vitro analysis of triolein hydrolysis using various phospholipid emulsifiers may be useful for the further understanding of impaired LPL function.

Imaging of Triglycerides in Human Coronary Plaques by Color Fluorescent Angioscopy and Microscopy

Native triglycerides (TG) deposited in the human vascular wall is not measurable or visible in vivo to date. We discovered that by exciting fluorescence at 345 nm and emitting at 420 nm, 3-amino-4-hydroxy-5-nitrobenzene sulfonic acid monohydrate (3-ANA) elicits a brown fluorescence that is characteristic of just TG. Therefore, localization of TG in coronary plaques and normal segments that were obtained from 19 human autopsy cases was examined by color fluorescent angioscopy (CFA) and microscopy using 3-ANA as a biomarker of TG. By CFA, the percentage (%) incidence of TG in 23 normal segments, 13 white plaques without lipid deposition, 18 white plaques (growth stage) with lipid deposition, 11 yellow plaques without necrotic core (mature stage), and 12 yellow plaques with necrotic core (advanced mature stage) was 95, 92, 50, 27, and 25, respectively. By color fluorescent microscopy, TG deposited mostly in the fibrotic area of the plaques. Contrary to the general belief that TG amount increases with plaque maturation, the results indicated that TG was deposited in most of the normal coronary segments, but the amount decreased with plaque maturation. If 3-ANA becomes applicable clinically, the CFA system could be used for imaging TG within coronary plaques in patients in vivo.

Measuring local immunoglobulin E in the inferior turbinate nasal mucosa in patients with allergic rhinitis

BACKGROUND

Studies show that immunoglobulin E (IgE) is produced in the local nasal mucosa in allergic rhinitis patients. However, no study involved the measurement of IgE levels in the local nasal mucosal tissue in allergic rhinitis patients. This study aimed to measure the local IgE levels in the nasal mucosal tissue and to compare the levels of total IgE and specific IgEs in the serum and the inferior turbinate nasal mucosa in allergic rhinitis patients using the AlaSTAT 3gAllergy assay (Siemens Healthcare Diagnostics AG, Erlangen, Germany).

METHODS

Total IgE antibodies and allergen-specific IgE antibodies in each sample of nasal mucosal tissue from 11 allergic rhinitis patients were measured with the AlaSTAT 3gAllergy assay. We compared the levels of total IgE and IgEs specific for house dust (HD), mites, and cedar pollen in the serum and the inferior turbinate.

RESULTS

The total IgE levels and the cedar pollen-specific IgE levels in the inferior turbinate mucosal tissue correlated significantly with their respective levels in serum. The HD- and mite-specific IgE levels in the inferior turbinate mucosal tissue did not correlate significantly with their respective levels in the serum.

CONCLUSIONS

Our results evaluating the correlations between nasal mucosal and serum levels of antigen-specific IgE indicate that IgE produced in the nasal mucosa affects the IgE levels in the serum, especially the cedar pollen-specific IgE.

Clinical predictors for high-grade bladder cancer before first-time transurethral resection of the bladder tumor: a retrospective cohort study

The aim of this study was to identify the clinical predictors related to the risk of high-grade bladder cancer before first-time transurethral resection of the bladder tumor (TUR-Bt) and to externally validate the accuracy of Shapur's nomogram predicting the risk of high-grade bladder cancer in Japanese patients. As a result, episode of gross hematuria (odds ratio: 2.68, P = 0.02), larger tumor size (odds ratio: 1.89, P < 0.01) and positive urinary cytology (odds ratio: 8.34, P < 0.01) were found to be significant predictors for high-grade bladder cancer. Furthermore, the nomogram showed a high predictive accuracy in our Japanese population (area under the curve: 0.79). Clinicians will be able to predict high-grade bladder cancer using the common factors in Shapur's study and ours, such as tumor size and urinary cytology, and gross hematuria as the additional factor first identified here to decide priorities for the treatment of patients diagnosed with bladder cancer.

Human pericoronary adipose tissue as storage and possible supply site for oxidized low-density lipoprotein and high-density lipoprotein in coronary artery

BACKGROUND

Thickening of the pericoronary adipose tissue (PCAT) is a proven risk factor for coronary artery disease, but it is poorly understood whether PCAT stores pro-atherogenic substances with oxidized low-density lipoprotein (oxLDL) and low-density lipoprotein (LDL), and an anti-atherogenic substance with high-density lipoprotein (HDL) and supply them to the coronary intima.

METHODS

Using immunohistochemical techniques, the localization of oxLDL, LDL and HDL in PCAT and its adjacent coronary segments was examined in 30 epicardial coronary arteries excised from 11 human autopsy cases.

RESULTS

PCAT stored oxLDL and HDL in all, but LDL rarely, in 77 specimens examined, irrespective of the presence or absence of coronary plaques and underlying disease. The percentage (%) incidence of oxLDL, HDL and LDL deposits in intima was, respectively, 28, 10, 35 in 29 normal segments, 80 (p<0.05 vs. normal segments), 12, 75 in 19 white plaques (growth stage), 57, 36, 90 in 15 yellow plaques without necrotic core (NC; mature stage), and 40, 21, 100 (p<0.05 vs. normal segments) in 14 yellow plaques with NC (end-stage of maturation) as classified by angioscopy and histology. In coronary intima, oxLDL deposited in either a dotted or diffuse pattern whereas HDL and LDL showed diffuse patterns. Dotted oxLDL deposits were contained in CD68(+)-macrophages traversing the border of PCAT and adventitia, external and internal elastic laminae. Diffuse oxLDL and HDL deposits colocalized with intimal vasa vasorum.

CONCLUSIONS

The results suggested that, as a hitherto unrecognized supplying route, the human PCAT stores oxLDL and HDL and oxLDL is supplied to coronary intima either by CD68(+)-macrophages or vasa vasorum and HDL by vasa vasorum, and that deposition of oxLDL and HDL in the intima increased with plaque growth but the former decreased while the latter increased further with plaque maturation. Molecular therapy targeting PCAT before plaque maturation could be effective in preventing atherosclerosis.

Levels of soluble LR11/SorLA are highly increased in the bile of patients with biliary tract and pancreatic cancers

BACKGROUND

The utility of molecules derived from cancer cells as biomarkers of the pathological status in biliary tract and pancreatic cancers is still limited. Soluble LDL receptor relative with 11 ligand-binding repeats (sLR11), a molecule released from immature cells, has been shown to be a circulating biomarker for early stage hematological malignancies.

METHODS

We have evaluated the pathological significance of bile sLR11 levels in 147 samples from 72 patients with biliary tract cancer (BTC), pancreatic cancer (PC), or benign diseases.

RESULTS

The bile sLR11 levels in the cancer patients were significantly increased compared with those in patients without cancer, independent of cytological detection of cancer cells in bile. The average bile sLR11 levels in cancer patients were significantly higher than in those with benign diseases, while levels of bile carbohydrate antigen 19-9 (CA19-9) and carcinoembryonic antigen (CEA) were not different. LR11 protein was found to be highly expressed in the BTC and PC cells. The LR11 transcript levels in cholangiocarcinoma and pancreatic cancer cell lines were sharply induced during proliferation and significantly increased under hypoxic conditions.

CONCLUSIONS

Therefore, sLR11 levels in bile may be indicative of cancer cell conditions and may serve as potential novel biomarker in patients with BTC and PC.

Pericoronary Adipose Tissue as Storage and Supply Site for Oxidized Low-Density Lipoprotein in Human Coronary Plaques

OBJECTIVES

It is generally believed that low-density lipoprotein enters the vascular wall from its lumen and oxidized (oxLDL), after which it plays an important role in atherosclerosis. Because voluminous epicardial adipose tissue is a risk factor for coronary events, there is a possibility that the pericoronary adipose tissue (PCAT), which is a part of epicardial adipose tissue, acts as a risk factor by supplying oxLDL to the coronary arterial wall. The present study was performed whether PCAT stores and supplies oxLDL to the coronary wall.

METHODS

Localization of oxLDL in PCAT and its relation to plaque morphology were examined by immunohistochemical techniques in 27 epicardial coronary arteries excised from 9 human autopsy cases.

RESULTS

OxLDL deposited in all PCAT of the studied cases. The percent (%) incidence of oxLDL in the intima of 25 normal segment, 19 white plaques, 15 yellow plaques without necrotic core (NC) and 10 yellow plaques with NC, was 32, 84, 93 (p<0.05 vs normal segments and yellow plaques with NC), and 30, respectively. OxLDL deposited either in dotted or diffuse pattern. Double immunohistochemical staining revealed that the dotted oxLDL was that contained in CD68(+)-macrophages. The oxLDL-containing macrophages were observed in the interstitial space but not inside of the vasa vasorum, and they traversed PCAT, adventitia, external and internal elastic laminae, suggesting their migration towards the intima. Diffuse oxLDL deposits were observed in 17 preparations, the majority of which were co-localized with the vasa vasorum in outer or in both inner and outer halves of intima, and rarely in the inner half alone.

CONCLUSIONS

The results suggested that PCAT is a supply source of oxLDL to coronary intima and acts as a risk factor for coronary events, that oxLDL increasingly deposits in the intima with plaque growth and decreases after plaque maturation, and therefore molecular therapies targeting the PCAT before plaque growth could be effective in preventing human coronary atherosclerosis.

External validation and comparison of two nomograms predicting the probability of Gleason sum upgrading between biopsy and radical prostatectomy pathology in two patient populations: a retrospective cohort study

The aim of this study is to validate and compare the predictive accuracy of two nomograms predicting the probability of Gleason sum upgrading between biopsy and radical prostatectomy pathology among representative patients with prostate cancer. We previously developed a nomogram, as did Chun et al. In this validation study, patients originated from two centers: Toho University Sakura Medical Center (n = 214) and Chibaken Saiseikai Narashino Hospital (n = 216). We assessed predictive accuracy using area under the curve values and constructed calibration plots to grasp the tendency for each institution. Both nomograms showed a high predictive accuracy in each institution, although the constructed calibration plots of the two nomograms underestimated the actual probability in Toho University Sakura Medical Center. Clinicians need to use calibration plots for each institution to correctly understand the tendency of each nomogram for their patients, even if each nomogram has a good predictive accuracy.

Primary retroperitoneal mucinous cystic tumors with borderline malignancy: a case report and literature review

Primary retroperitoneal mucinous cystic tumors with borderline malignancy are rarely encountered. To date, only 12 cases have been reported in the literature. In this report, we present an additional case. A 65-year-old nulliparous woman complained of abdominal fullness. Her medical history included a hysterectomy and a single salpingo-oophorectomy performed 25 years prior to the present event. Physical examination revealed a large cystic mass in the abdomen and pelvis. During laparotomy, a cystic tumor measuring 21×14 cm in size was observed in the left retroperitoneal space. The tumor was resected, and the final diagnosis was primary retroperitoneal mucinous cystic cancer with borderline malignancy.

Migration of intraocular silicone oil from the vitreous cavity into the upper eyelid causing ptosis

Introduction

To report a case in which intraocular silicone oil migrated into the upper eyelid and caused ptosis.

Methods

A 65-year-old woman presented with proliferative vitreoretinopathy in the right eye. Vitrectomies, injection of silicone oil and encircling were performed. Two months after the last operation, swelling of her right eyelid occurred.

Result

Magnetic resonance imaging revealed moisture in the palpebral fat tissue. We incised the bulbar conjunctiva and confirmed silicone oil leakage from the vitreous cavity through the scleral button hole of the encircling suture. Postoperatively, the right upper eyelid swelling decreased. Histopathologically, dense macrophage infiltration was seen in the palpebral tissues.

Conclusions

We report a rare case with a postoperative complication caused by silicone oil. In cases with swelling of the eyelid and decreased silicon oil in the vitreous cavity postoperatively, clinicians should consider the possibility of silicone oil leakage.

Evaluation of plasma vascular endothelial growth factor levels after intravitreal injection of ranibizumab and aflibercept for exudative age-related macular degeneration

BACKGROUND

To evaluate the plasma vascular endothelial growth factor (VEGF) levels after one intravitreal injection of aflibercept or ranibizumab in patients with exudative age-related macular degeneration (AMD).

METHODS

Twenty-four Japanese with exudative AMD, polypoidal choroidal vasculopathy, and retinal angiomatous proliferation were included. Fourteen patients received an intravitreal injection of aflibercept, and ten patients received an intravitreal injection of ranibizumab. Plasma VEGF levels were evaluated within 7 days before the intravitreal injections and 1 day, 1 week, and 1 month after the intravitreal injection.

RESULTS

In the ranibizumab group, the mean plasma VEGF levels were 245.7 ± 233.4 pg/ml before the injection, 246.6 ± 304.8 pg/ml after 1 day, 217.8 ± 212.9 pg/ml after 1 week, and 260.0 ± 290.1 pg/ml after 1 month. The plasma VEGF levels did not decrease significantly in patients in the ranibizumab group at any time point. In the aflibercept group, the mean plasma VEGF levels were 280.0 ± 170.3 pg/ml before the intravitreal injection and 8.2 ± 12.9 pg/ml after 1 day, 9.1 ± 9.1 pg/ml after 1 week, and 41.9 ± 41.4 pg/ml after 1 month (p < 0.0001, vs before injection).

CONCLUSION

Intravitreally injected aflibercept reduced plasma VEGF over at least 1 month. In contrast, intravitreal injection of ranibizumab did not cause a significant reduction in the plasma VEGF levels.

Imaging of native high-density lipoprotein in human coronary plaques by color fluorescent angioscopy

BACKGROUND

High-density lipoprotein (HDL) plays a key role in reverse cholesterol transport, and halts the progression of atherosclerosis. The aim of the present study was to visualize native HDL in the human coronary arterial wall.

METHODS AND RESULTS

The fluorescence characteristics of HDL were investigated by color fluorescent microscopy (CFM) using excitation at 470 nm and emission at 515 nm with Fast green dye (FG) as the biomarker. HDL in 30 normal coronary segments, and in 25 white and 25 yellow plaques in excised human coronary arteries, was visualized by color fluorescent angioscopy (CFA) and CFM. Localization of HDL visualized by CFM was compared with that stained by immunostaining using an anti-HDL antibody. FG elicited a characteristic brown fluorescence of HDL. By CFA, the percent incidence of HDL in normal segments, white (early stage of plaque growth) and yellow (advanced stage of plaque growth) plaques was, respectively, 33%, 76% (P<0.05 vs. normal segments and yellow plaques) and 21%. Localization of HDL visualized by CFM did not differ from that stained by immunostaining.

CONCLUSIONS

In the human coronary arterial wall, HDL deposits infrequently in normal segments, but increasingly deposits with plaque formation, and decreases in the advanced stage of plaque growth.

Localization of native high-density lipoprotein and its relation to plaque morphology in human coronary artery

High-density lipoprotein (HDL) plays a key role in reverse cholesterol transport, and halts the progression of atherosclerosis. However, its localization in human vascular wall is not well understood. We discovered that by exciting at 470-nm and emitting at 515-nm light wavelengths, Fast green dye (FG) elicits brown fluorescence characteristic of HDL only. Therefore, the localization of native HDL in normal segments and plaques in excised human coronary artery was investigated by scanning their transected surface with color fluorescent microscopy (CFM) using FG as a biomarker, and the relationships between the localization of HDL and morphology of plaques and normal segments classified by conventional angioscopy and histology were examined. The % incidence of HDL in 13 normal segments (NS) with thin (≤ 200 µm) intima, 28 NS with thick (200 µm <) intima, 41 white plaques (early stage of plaque growth), 15 yellow plaques (Y) without necrotic core (NC), and 20 Y with NC (advanced stage of plaque growth), was 30, 71 (P < 0.05 versus NS with thin intima and Y with NC), 83 (P < 0.05 versus NS with thin intima and Y with NC), 60, and 35, respectively. HDL begins to deposit in human coronary arterial wall in the early stage of atherosclerosis and deposits increase with plaque growth, but HDL decreases in plaques at an advanced stage of growth.

Tumor-like growth of giant inflammatory polyposis in a patient with ulcerative colitis

We report a unique case of giant obstructing inflammatory polyposis associated with ulcerative colitis (UC). A 25-year-old Japanese man with an UC history of 2 years and 6 months was referred to our institution because of diarrhea and melena. His computed tomography scan showed marked dilation of the transverse and descending colon; therefore, we performed total colectomy. Macroscopic evaluation of the excised specimen indicated constricting lesions with giant polyposis in the transverse and descending colon. The polyposis consisted of narrow worm- or noodle-like polyps that bridged over the irregular ulcers. Histologic evaluation of the excised specimen indicated transmural inflammation with a thickened proper muscular layer overlaid with inflammatory polyposis. Based on these data, a diagnosis of giant inflammatory polyposis should be considered in patients who have had UC. Although giant inflammatory polyposis is considered benign, surgical treatment may be indicated to avoid serious complications.

Molecular imaging of apolipoprotein B-100 in human coronary plaques by color fluorescent angioscopy and microscopy

Apolipoprotein B-100 (ApoB-100) is an important risk factor for coronary artery disease. However, its localization in human coronary plaques is not well understood. The present study was performed to visualize ApoB-100 in human coronary artery wall. Deposition of native ApoB-100 in excised human coronary plaques and normal segments classified by conventional angioscopy was investigated by color fluorescent angioscopy (CFA) and microscopy (CFM) using Nile blue dye (NB) which elicits a golden fluorescence characteristic of ApoB-100 as a biomarker. By CFA, the % incidence of ApoB-100 was 20 in 40 normal segments, 38 in 42 white, and 11 in 35 yellow plaques (P < 0.05 versus white plaques). There was no significant difference in detection sensitivity between CFA and luminal surface scan by CFM. By CFM transected surface scan, ApoB-100 deposited in superficial, deep, and/or in both layers. Deposition in both layers was frequently observed in white plaques and yellow plaques without necrotic core (NC), less frequently in normal segments, and rarely in yellow plaques with NC. (1) Taking into consideration the well known process of plaque growth, the results suggest that ApoB-100 begins to deposit before plaque formation, increasingly deposits with plaque growth, and disappears after necrotic core formation. (2) CFA is feasible for imaging of ApoB-100 in human coronary artery wall.

Localization of oxidized low-density lipoprotein and its relation to plaque morphology in human coronary artery

OBJECTIVES

Oxidized low-density lipoprotein (oxLDL) plays a key role in the formation of atherosclerotic plaques. However, its localization in human coronary arterial wall is not well understood. The present study was performed to visualize deposition sites and patterns of native oxLDL and their relation to plaque morphology in human coronary artery.

METHODS

Evans blue dye (EB) elicits a violet fluorescence by excitation at 345-nm and emission at 420-nm, and a reddish-brown fluorescence by excitation at 470-nm and emission at 515-nm characteristic of oxLDL only. Therefore, native oxLDL in excised human coronary artery were investigated by color fluorescent microscopy (CFM) using EB as a biomarker.

RESULTS

(1) By luminal surface scan with CFM, the % incidence of oxLDL in 38 normal segments, 41 white plaques and 32 yellow plaques that were classified by conventional angioscopy, was respectively 26, 44 and 94, indicating significantly (p<0.05) higher incidence in the latter than the former two groups. Distribution pattern was classified as patchy, diffuse and web-like. Web-like pattern was observed only in yellow plaques with necrotic core. (2) By transected surface scan, oxLDL deposited within superficial layer in normal segments and diffusely within both superficial and deep layers in white and yellow plaques. In yellow plaques with necrotic core, oxLDL deposited not only in the marginal zone of the necrotic core but also in the fibrous cap.

CONCLUSION

Taken into consideration of the well-known process of coronary plaque growth, the results suggest that oxLDL begins to deposit in human coronary artery wall before plaque formation and increasingly deposits with plaque growth, exhibiting different deposition sites and patterns depending on morphological changes.