Standardization of evaluation method and prognostic significance of histological response to preoperative chemotherapy in high-grade non-round cell soft tissue sarcomas.

BACKGROUND: Preoperative chemotherapy is widely applied to high-grade localized soft tissue sarcomas (STSs); however, the prognostic significance of histological response to chemotherapy remains controversial. This study aimed to standardize evaluation method of histological response to chemotherapy with high agreement score among pathologists, and to establish a cut-off value closely related to prognosis. METHODS: Using data and specimens from the patients who had registered in the Japan Clinical Oncology Group study, JCOG0304, a phase II trial evaluating the efficacy of perioperative chemotherapy with doxorubicin (DOX) and ifosfamide (IFO), we evaluated histological response to preoperative chemotherapy at the central review board. RESULTS: A total of 64 patients were eligible for this study. The percentage of viable tumor area ranged from 0.1% to 97.0%, with median value of 35.7%. Regarding concordance proportion between pathologists, the weighted kappa coefficient (κ) score in all patients was 0.71, indicating that the established evaluation method achieved substantial agreement score. When the cut-off value of the percentage of the residual tumor area was set as 25%, the p-value for the difference in overall survival showed the minimum value. Hazard ratio of the non-responder with percentage of the residual tumor < 25%, to the responder was 4.029 (95% confidence interval 0.893-18.188, p = 0.070). CONCLUSION: The standardized evaluation method of pathological response to preoperative chemotherapy showed a substantial agreement in the weighted κ score. The evaluation method established here was useful for estimating of the prognosis in STS patients who were administered perioperative chemotherapy with DOX and IFO. TRIAL REGISTRATION: UMIN Clinical Trials Registry C000000096. Registered 30 August, 2005 (retrospectively registered).

[Improved QOL in a Case of Breast Cancer with Meningeal Carcinomatosis Treated with Radiation Therapy and Intrathecal Chemotherapy].

A 50's woman was diagnosed with left local-advanced breast cancer(pT4bN2aM0, stage ⅢB, estrogen-receptor positive and human epidermal growth factor-2 negative)in 2016. Neoadjuvant therapy consisting of 4 courses of epirubicin plus cyclophosphamide and 4 courses of docetaxel were administered. After neoadjuvant therapy, a mastectomy with axillary node dissection was performed. And after surgery, she was received radiation and endocrine therapy. In May 2019, multiple bone metastases were detected. We administered endocrine therapy. In February 2020, she developed leg paralysis and malignant cells were collected from the cerebrospinal fluid. She was diagnosed with meningeal carcinomatosis without brain metastasis from breast cancer. To improve quality of life, we started radiation therapy, intrathecal chemotherapy and systemic chemotherapy. After 3 months of these therapies, leg paralysis was improved and quality of life was maintained for 9 months. Herein, we report a case of meningeal carcinomatosis without brain metastasis from breast cancer which is improved by radiation therapy, intrathecal chemotherapy and systemic chemotherapy.

Aryl hydrocarbon receptor counteracts pharmacological efficacy of doxorubicin via enhanced AKR1C3 expression in triple negative breast cancer cells.

Triple-negative breast cancer (TNBC) is associated with poor prognosis, because of no effective targeted therapy. In the present study, we demonstrated the crucial role of the aryl hydrocarbon receptor (AhR) in mediating the effects of the chemotherapeutic agent doxorubicin (DOX) in the chemotherapeutic sensitivity of TNBC. Firstly, we established AhR knockout (KO) MDA-MB 231 TNBC cells. The cytotoxic effects of DOX were more pronounced in AhR KO cells than in parental cells. In addition, our results indicated that AhR KO cells showed downregulated expression of DOX-metabolism enzyme, aldo-keto reductase (AKR) 1C3, relative to those of parental cells. Furthermore, AhR was found to enhance AKR1C3 promoter reporter activity, suggesting that AKR1C3 mRNA transcription is activated by AhR. Additionally, our findings confirmed that the downregulation of AKR1C3 expression enhanced DOX sensitivity in MDA-MB 231 cells. Finally, AhR and AKR1C3 expression were positively correlated in human breast cancer. Taken together, our results suggested that AhR is involved in DOX sensitivity by regulating AKR1C3 expression in TNBC cells.

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.

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.

Development and external validation of a nomogram to predict high-grade papillary bladder cancer before first-time transurethral resection of the bladder tumor.

BACKGROUND: The aim of this study was to identify the clinical predictors related to the risk of high-grade papillary bladder cancer before first-time transurethral resection of a bladder tumor (TUR-Bt), and to develop and validate a nomogram predicting the risk of high-grade papillary bladder cancer. METHODS: A retrospective clinical study of consecutive patients who underwent first-time TUR-Bt for papillary bladder cancer was performed. Medical records were reviewed uniformly, and the following data were collected: age, sex, episodes of urinary symptoms, tumor size, number of tumors, location of the largest tumor (lateral walls, base, posterior wall, dome, and anterior wall), tumor appearance (papillary or non-papillary, pedunculated or sessile), and urinary cytology. Data from 254 patients (Group A) were used for the development of a nomogram, while data from 170 patients (Group B) were used for its external validation. RESULTS: High-grade papillary bladder cancer was pathologically diagnosed in 51.6 and 74.6% of Group A and Group B patients, respectively. Based on univariable analyses in Group A, macrohematuria, tumor size, multiple tumors, appearance, and positive urinary cytology were selected as variables to incorporate into a nomogram. The AUC value was 0.81 for the internal validation (Group A), and 0.78 for the external validation (Group B). This novel nomogram can predict high-grade papillary bladder cancer accurately. CONCLUSIONS: The present nomogram can help clinicians calculate the probability in patients with bladder cancer before TUR-Bt and decide on earlier intervention and priorities for the treatment of patients diagnosed with bladder cancer.

Detection of Ceramide, a Risk Factor for Coronary Artery Disease, in Human Coronary Plaques by Fluorescent Angioscopy.

BACKGROUND: The presence of ceramide in human coronary plaques is a risk factor for ischemic heart disease, but its visualization in the human vessel wall is currently beyond the scope of any available imaging techniques.Methods and Results:Deposition of ceramide was examined by fluorescent angioscopy (FA) and microscopy (FM) using golden fluorescence (Go) as a specific marker of ceramide in yellow plaques, which were obtained from 23 autopsy subjects and classified by conventional angioscopy and histology. Ceramide was observed by FM in 34 of the 41 yellow plaques with a necrotic core (NC) but rarely in the 28 without. Ceramide and macrophages/foam cells co-deposited mainly in the border zone of the NC and fibrous cap (FC). The Go of ceramide was seen when the fibrous cap thickness was ≤100 µm. FA was performed to detect coronary plaques exhibiting Go in patients with coronary artery disease. Ceramide was also detected by FA in 6 of 18 yellow plaques (33.3%) in 8 patients with stable angina and in 18 of 24 yellow plaques (75.0%, P<0.05 vs. stable angina) in 8 patients with old myocardial infarction. CONCLUSIONS: The Go of ceramide in human coronary plaques is detectable by FA and Go could be used as a marker of vulnerable plaque (i.e., thin FC with NC).

Soluble form of LR11 is highly increased in the vitreous fluids of patients with idiopathic epiretinal membrane.

PURPOSE: LR11 (also called SorLA or SORL1) is a migration regulator of adherent cells with the immature proliferative phenotype. The present study investigated the clinical and pathological involvement of the soluble form of LR11 (sLR11) in the idiopathic epiretinal membrane (iERM). METHODS: The subjects were 51 patients with iERM (24 cellophane macular reflex (CMR) and 27 preretinal macular fibrosis (PMF)) and 45 patients with macular holes as age and sex-matched controls. Vitreous sLR11 and transforming growth factor (TGF)ß2 levels were measured by ELISA. RESULTS: The sLR11 levels in the vitreous fluids of patients with iERM (20.2 ± 8.1 ng/mL) were significantly higher than those in controls (11.4 ± 4.7 ng/mL). Among the patients with iERM, the vitreous sLR11 levels were significantly higher in PMF (23.6 ± 8.2 ng/mL), than those in CMR (16.5 ± 5.9 ng/mL). Multivariate regression analysis of the studied factors showed that sLR11 was a unique factor independently contributing to the discrimination of the iERM patients against the control subjects (odds ratio [OR] 1.35 per 1-ng/mL increase, 95% CI 1.09-1.67; P = 0.004). ROC analysis showed that the sensitivity and the specificity of sLR11, but not of other studied factors, categorized into the rank of moderate accuracy. Finally, there was a positive correlation (R = 0.588; P = 0.003) between the vitreous levels of sLR11 and TGFß2 using the available samples. CONCLUSIONS: sLR11 levels in vitreous fluids were specifically increased in patients with iERM, suggesting the involvement in the pathology of proliferative and migrating cells for the development of iERM.

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.

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.

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.

[CLINICOPATHOLOGICAL STUDY OF PROSTATE BIOPSY IN PATIENTS RECEIVING DUTASTERIDE FOR BENIGN PROSTATIC HYPERPLASIA].

OBJECTIVE: Dutasteride is a 5-alpha reductase inhibitor used to treat benign prostatic hyperplasia. Dutasteride lowers prostate-specific antigen (PSA) levels, which may lead to delays in the diagnosis and treatment of prostate cancer (PCa). This study investigated patients who underwent prostate biopsy (PBx) while receiving dutasteride to investigate whether this agent affects the diagnosis and treatment of PCa. PATIENTS AND METHODS: PBx was performed on six patients receiving dutasteride for > 3 months at our medical institutions between January 2010 and June 2013. No patients underwent PBx before dutasteride administration. We performed PBx both for patients with high initial PSA levels and for those with elevated PSA levels with or without initial PSA decline after dutasteride administration. We also investigated clinicopathological findings. RESULTS: Mean age at the start of administration was 69.5 ± 5.9 years (range, 59-77 years), mean duration of administration was 14.1 ± 7.4 months (range, 4.0-23.5 months), mean prostate volume at the start of administration was 70.4 ± 30.7 ml (range, 18.8-104.6 ml), and mean PSA level at the start of administration was 7.7 ± 3.3 ng/ml (range, 4.9-14.2 ng/ml). PSA density was 0.098 ± 0.045 ng/ml/cm3 (range, 0.042-0.181 ng/ml/cm3), and PSA level at PBx was 5.4 ± 2.7 ng/ml (range, 2.5-10.7 ng/ml). We detected three PCa patients, and clinical stage in each case was cT1cN0M0. Radical retropubic prostatectomy was performed in two cases, and androgen-deprivation therapy was performed in one case. CONCLUSION: All PCa were detected in the early clinical stage. No delays in detection or treatment of PCa were seen in any cases. Careful observation of PSA levels is simple and useful for detecting PCa in patients under dutasteride administration.

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.

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.

A Case of Anti-Synthetase Syndrome With Anti-Glycyl tRNA Synthetases Antibody Developed After COVID-19.

Coronavirus disease 2019 (COVID-19) is a life-threatening respiratory disease characterized by severe acute infection. In some cases, COVID-19 symptoms may persist for a long term, posing a significant social problem. Long-term COVID-19 symptoms resemble those observed in various autoimmune diseases, such as dermatomyositis and polymyositis. In this report, we present the case of a 55-year-old woman who had been experiencing persistent dyspnea on exertion since contracting COVID-19 a month ago and was subsequently diagnosed with anti-synthetase syndrome (ASS). The patient presented with fever, dyspnea, rash, mechanic's hands, and arthritis. Computed tomography imaging revealed findings indicative of interstitial pneumonia. Immunological test results were positive for anti-EJ antibody, leading to a diagnosis of ASS based on Solomon's established criteria. The patient's condition improved following treatment with prednisolone, tacrolimus, and intravenous cyclophosphamide. Pathological findings of transbronchial biopsy revealed nonspecific interstitial pneumonia with organizing pneumonia, leading to speculation that ASS had developed after COVID-19. Given the scarcity of reports on ASS development post COVID-19, we conducted a literature review and compared our present case to previous ones. This report highlights the importance of considering ASS in the differential diagnosis of patients with long-term COVID-19 symptoms.

The association between CD34 expression status and the clinicopathological behavior of dedifferentiated liposarcoma.

Lipogenic and fibrous tumors are thought to originate from CD34-positive stromal fibroblastic/fibrocystic cells. Well-differentiated lipogenic tumors typically express CD34, whereas dedifferentiated liposarcoma (DDLPS) often loses it. We conducted survival analyses involving 59 patients with DDLPS. Males comprised 53% of the cohort, and the median age at the time of wide resection of primary DDLPS was 60 years. Loss of CD34 expression was defined as when ≥50% of the dedifferentiated area was immunohistochemically negative for CD34. As a result, 39 of the 59 patients showed loss of CD34 expression during the initial operation for DDLPS. In the univariate analyses, the tumor site in the retroperitoneum/abdominal cavity and loss of CD34 expression were significantly associated with poor overall survival. In the multivariate analyses, loss of CD34 expression (HR = 2.26; 95% CI = 1.02-5.02; p = 0.04) and the tumor site in the retroperitoneum/abdominal cavity (HR = 3.11; 95% CI = 1.09-8.86; p = 0.03) were retained as independent prognostic factors. Six CD34-positive cases lost CD34 expression when they developed metastasis and/or local recurrence, suggesting that the loss was associated with the later stage of the tumor. Therefore, an association existed between the loss of CD34 expression and clinicopathological behaviors such as poorer prognoses and recurrence.

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.

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.

Smooth muscle-like cells resident in the media participate in spasm-induced coronary intimal hyperplasia.

BACKGROUND: Coronary intimal hyperplasia occurs at the site of spasm in patients with vasospastic angina. The migration of vascular smooth muscle cells (VSMCs) from the media has been proposed as a potential mechanism; however, this has not been confirmed with supportive evidence. OBJECTIVE: To determine which cell types participate in spasm-induced coronary intimal hyperplasia. METHODS: Morphological changes in spastic coronary artery segments in beagles were examined using electron microscopy and immunohistochemical staining of cell markers at 1 h, 3 h and 6 h, and two and four weeks after spasm provocation. RESULTS: Small smooth muscle-like cells (SMLCs) were observed in the media of nonspastic coronary segments using electron microscopy. These cells attached side-to-side to large, known VSMCs. At 1 h to 6 h after spasm provocation, SMLCs separated from VSMCs, changed to an amoebic configuration and migrated through cleaved junctions or disrupted portions of the internal elastic lamina into the subendothelial space. The SMLCs expressed alpha-smooth muscle actin and N-cadherin, but not smooth muscle myosin heavy chain-1 and ß-actin, suggesting that they were myofibroblasts and not a synthetic phenotype of VSMCs. Intimal hyperplasia was observed in all preparations at two and four weeks after spasm provocation. Furthermore, alpha-smooth muscle actin-positive SMLCs, often amoebic in configuration, were observed in the hyperplastic intima. CONCLUSIONS: On coronary spasm provocation, SMLCs (ie, possible myofibroblasts) resident in the media migrate as a spearhead into the intima and play a role in coronary intimal hyperplasia.