Bortezomib overcomes cell-adhesion-mediated drug resistance through downregulation of VLA-4 expression in multiple myeloma.

Multiple myeloma (MM) is incurable, mainly because of cell adhesion-mediated drug resistance (CAM-DR). In this study, we performed functional screening using short hairpin RNA (shRNA) to define the molecule(s) responsible for CAM-DR of MM. Using four bona fide myeloma cell lines (KHM-1B, KMS12-BM, RPMI8226 and U266) and primary myeloma cells, we identified CD29 (beta1-integrin), CD44, CD49d (alpha4-integrin, a subunit of VLA-4), CD54 (intercellular adhesion molecule-1 (ICAM-1)), CD138 (syndecan-1) and CD184 (CXC chemokine receptor-4 (CXCR4)) as major adhesion molecules expressed on MM. shRNA-mediated knockdown of CD49d but not CD44, CD54, CD138 and CD184 significantly reversed CAM-DR of myeloma cells to bortezomib, vincristine, doxorubicin and dexamethasone. Experiments using blocking antibodies yielded almost identical results. Bortezomib was relatively resistant to CAM-DR because of its ability to specifically downregulate CD49d expression. This property was unique to bortezomib and was not observed in other anti-myeloma drugs. Pretreatment with bortezomib was able to ameliorate CAM-DR of myeloma cells to vincristine and dexamethasone. These results suggest that VLA-4 plays a critical role in CAM-DR of MM cells. The combination of bortezomib with conventional anti-myeloma drugs may be effective in overcoming CAM-DR of MM.

Expression of SR-PSOX, a novel cell-surface scavenger receptor for phosphatidylserine and oxidized LDL in human atherosclerotic lesions.

Receptor-mediated endocytosis of oxidized low density lipoprotein (Ox-LDL) by macrophages and the subsequent foam cell transformation in the arterial intima are key events in early atherogenesis. Recently, we have identified a novel macrophage cell-surface receptor for Ox-LDL by expression cloning from a cDNA library of phorbol 12-myristate 13-acetate-stimulated THP-1 cells, designated as the scavenger receptor for phosphatidylserine and oxidized lipoprotein (SR-PSOX). Here, we examined SR-PSOX expression in human atherosclerotic lesions. Total cellular RNA and fresh frozen sections were prepared from human carotid endarterectomy specimens (from 21 patients) and directional coronary atherectomy specimens (from 11 patients). Fragments of human aortas of 2 patients without visible atherosclerotic lesions served as negative controls. Quantitative reverse transcription-polymerase chain reaction demonstrated that SR-PSOX mRNA expression was prominent in atherosclerotic lesions but undetectable in normal aortas. Immunohistochemistry showed that SR-PSOX was predominantly expressed by lipid-laden macrophages in the intima of atherosclerotic plaques in carotid endarterectomy and directional coronary atherectomy specimens, although its expression was not detectable in normal arterial wall. Double-labeled immunohistochemistry confirmed that SR-PSOX is expressed by intimal macrophages. Taken together, SR-PSOX may be involved in Ox-LDL uptake and subsequent foam cell transformation in macrophages in vivo and thus may play important roles in human atherosclerotic lesion formation.

Long-term clinical outcomes after unprotected left main trunk percutaneous revascularization in 279 patients.

BACKGROUND: Percutaneous coronary revascularization (PCI) has been increasingly applied to unprotected left main trunk (LMT) lesions, with varied long-term success. This study attempts to define the predictors of outcome in this population. METHODS AND RESULTS: Two hundred seventy-nine consecutive patients who had LMT PCI at 1 of 25 sites between 1993 and 1998 were studied. Forty-six percent of these patients were deemed inoperable or at high surgical risk. Thirty-eight patients (13.7%) died in hospital, and the rest were followed up for a mean of 19 months. The 1-year incidence was 24.2% for all-cause mortality, 20.2% for cardiac mortality, 9.8% for myocardial infarction, and 9.4% for CABG. Independent correlates of all-cause mortality were left ventricular ejection fraction /=2.0 mg/dL, and severe lesion calcification. For the 32% of patients <65 years old with left ventricular ejection fraction >30% and without shock, the prevalence of these adverse risk factors was low. No periprocedural deaths were observed in this low-risk subset, and the 1-year mortality was only 3.4%. CONCLUSIONS: Patients undergoing unprotected LMT PCI have frequent serious comorbidities and consequently have high event rates. PCI may be an alternative to CABG for a select proportion of elective patients and may also be appropriate for highly symptomatic inoperable patients. Meticulous follow-up of hospital survivors is required because of the rather high mortality during the first few months after treatment.

[Detection of monoclonal plasma cells in bone marrow and spleen of primary amyloidosis].

A 53-year-old man was diagnosed as primary amyloidosis by biopsy specimens of the mucosa in rectum, spleen and bone marrow (BM). BM examination showed 5.5% of plasma cells with some dysplasia. Immunoglobulin heavy chain gene rearrangement was detected by polymerase chain reaction using third-complementary-determining region (CDR 3) specific primers in BM mononuclear cells and spleen cells embedded in paraffin. The sequence analysis revealed that monoclonal B cells existed in the both, BM and spleen. Flowcytometric analysis using two-color staining showed the phenotype of plasma cells with the expression of CD19+/-, CD27+/-, CD56+/- and CD138+ and CD38++. This phenotype is similar to those of monoclonal gammopathy of undetermined significance (MGUS). Therefore, primary amyloidosis is considered to have two plasma cell populations including normal plasma cells and monoclonal plasma cells in BM. Given that there are two types of plasma cells in patients with primary amyloidosis, amyloid protein is expected to originate from immunoglobulin light chain produced by monoclonal plasma cells.

Abundance of plaque microvessels is associated with constrictive remodeling in angioplastied human coronary arteries.

This study investigated if specific histological features correlate with remodeling in human coronary arteries treated by balloon angioplasty (PTCA). Segments of perfusion-fixed coronary arteries that had undergone antemortem PTCA were obtained from 15 patients and primary atherosclerotic (CAD) lesions obtained from these hearts were used as control lesions. Arterial segments were serially divided to yield 108 sub-segments for PTCA lesions and 38 sub-segments for CAD lesions. A linear regression analysis was used to determine the relationship between 14 histological parameters and an arbitrary index of compensatory arterial enlargement, the external elastic lamina (EEL) index (EELI), defined as the ratio of the area encompassed by the EEL to the sum of the intimal area (IA) + medial area (MA). In PTCA arteries the abundance of plaque microvessels negatively correlated with the EELI (p=0.04), but in CAD arteries there was no relationship between histology and the EELI. The abundance of plaque microvessels correlates with the magnitude of constriction in coronary artery lesions subjected to PTCA. This study provides descriptive insights into the biology of remodeling in human coronary arteries after angioplasty, and suggests that the endothelium may play an important role.

Arrest of human dendritic cells at the CD34-/CD4+/HLA-DR+ stage in the bone marrow of NOD/SCID-human chimeric mice.

Human dendritic cell (DC) precursors were engrafted and maintained in NOD/SCID- human chimeric mice (NOD/SCID-hu mice) implanted with human cord blood mononuclear cells, although no mature human DCs were detected in lymphoid organs of the mice. Two months after implantation, bone marrow (BM) cells of NOD/SCID-hu mice formed colonies showing DC morphology and expressing CD1a in methylcellulose culture with granulocyte-macrophage colony-stimulating factor (GM-CSF) and tumor necrosis factor alpha (TNF-alpha). The CD34-/CD4+/HLA-DR+ cell fraction in NOD/SCID-hu mouse BM generated CD1a(+) cells that were highly stimulatory in mixed leukocyte reactions in culture with GM-CSF and TNF-alpha. These results suggest a strong potential for NOD/SCID-hu BM to generate human DCs, although DC differentiation may be blocked at the CD34-/CD4+/HLA-DR+ stage. (Blood. 2001;97:3655-3657)

Differences in management and outcomes of acute myocardial infarction among four general hospitals in Japan.

OBJECTIVE: To ascertain the differences among hospitals in Japan in the management patterns and outcomes of patients with acute myocardial infarction (AMI). DESIGN: Retrospective cohort study by means of patient chart review. SETTING: Four tertiary-care teaching hospitals in Japan observed over a 1-year period. STUDY PARTICIPANTS: Consecutive patients (N=482) admitted for AMI. MAIN OUTCOME MEASURES: Clinical characteristics, rates of diagnostic and therapeutic procedures performed, cardiac complications, and length of stay. RESULTS: Patients' clinical characteristics differed significantly among the four hospitals in terms of age, gender, and prior cardiac history, but not in terms of comorbidity or infarct location. The frequency and type of diagnostic and therapeutic procedures were different, and in-hospital mortality varied (4-14%, P=0.022). Average length of hospital stay ranged from 15.8+/-12.6 days to 41.0+/-19.4 days (P=0.0001). After adjustment for the clinical characteristics, these differences remained significant among hospitals. CONCLUSION: Considerable differences in the management and outcomes of patients with AMI exist in Japan.

Usefulness of intracoronary angioscopy for elucidating the cause of subacute thrombosis after stenting.

Stent thrombosis is rare with anti-platelet therapy, which consists of aspirin and ticlopidine as a post-stenting administration. A 77-year-old man had repeated stent thrombosis, which was not predicted by coronary angiography, despite using contemporary periprocedural anti-platelet therapy. Only intravascular fiberscopy was able to detect the cause of the stent thrombosis.

Relation between preintervention remodeling and late arterial responses to coronary angioplasty or atherectomy.

We used the serial intravascular ultrasound (IVUS) data from the Serial Ultrasound REstenosis trial to explain why positive remodeling lesions have a higher rate of clinical restenosis after non-stent interventions. Serial IVUS was performed before intervention and immediately and 1 and 6 months after percutaneous transluminal coronary angioplasty (n = 35) or directional coronary atherectomy (n = 26). External elastic membrane, lumen, and plaque + media (external elastic membrane minus lumen) areas were measured at the reference and stenosis. Stenoses were divided into 3 groups: positive remodeling (lesion greater than proximal reference external elastic membrane), intermediate remodeling (lesion external elastic membrane smaller than proximal reference but larger than distal reference), and negative remodeling (lesion equal to or less than distal reference external elastic membrane). The early (postintervention to 1 month) and late (1- to 6-month) changes in lesion external elastic membrane and plaque + media areas were compared. An early increase in plaque + media area was associated with an equal or greater increase in external elastic membrane area in positive (r = 0.78, p < 0.0001), intermediate (r = 0.69, p < 0.0001), and negative (r = 0.59, p = 0.0003) remodeling lesions. A late (1- to 6-month) decrease in external elastic membrane area correlated inversely with the early increase in plaque + media area in positive (r = 0.77, p = 0.0002) and intermediate (r = 0.45, p = 0.0003), but not in negative (r = 0.02, p = 0.9) remodeling lesions. In positive remodeling lesions, the early increase in plaque + media area was associated with both an exaggerated early increase and late decrease in external elastic membrane area. Positive remodeling lesions have an exaggerated early increase in external elastic membrane area and, especially, an exaggerated late decrease in external elastic membrane area after percutaneous transluminal coronary angioplasty and directional coronary atherectomy. This may explain that the increased clinical restenosis after positive remodeling lesions is treated with non-stent interventions.

Diagnostic implications of elevated levels of smooth-muscle myosin heavy-chain protein in acute aortic dissection. The smooth muscle myosin heavy chain study.

BACKGROUND: A rapid 30-minute assay of circulating smooth-muscle myosin heavy-chain protein has been developed as a biochemical diagnostic tool for aortic dissection. OBJECTIVE: To determine the sensitivity and specificity of this assay. DESIGN: Cross-sectional study. SETTING: 8 major cardiovascular centers in Japan. PATIENTS: 95 patients with acute aortic dissection, 48 patients with acute myocardial infarction, and 131 healthy volunteers. MEASUREMENTS: Levels of circulating smooth-muscle myosin heavy-chain protein. RESULTS: Patients with acute aortic dissection who presented within 3 hours after onset had elevated levels of circulating smooth-muscle myosin heavy-chain protein. In these patients, the assay had a sensitivity of 90.9%, a specificity of 98% compared with healthy volunteers, and a specificity of 83% compared with patients who had acute myocardial infarction; the clinical decision limit was 2.5 microgram/L. All patients with proximal lesions had elevated levels of smooth-muscle myosin heavy-chain protein, and only patients with distal lesions had decreased levels (<2.5 microgram/L). CONCLUSIONS: Levels of smooth-muscle myosin heavy-chain protein can be used to diagnose aortic dissection soon after symptom onset. The assay had the greatest diagnostic value in patients with proximal lesions.

Review of immediate angioplasty after fibrinolytic therapy for acute myocardial infarction: insights from the RESCUE I, RESCUE II, and other contemporary clinical experiences.

BACKGROUND: Prompt restoration of Thrombolysis In Myocardial Infarction (TIMI) grade 3 flow improves survival in patients with acute ST-segment elevation myocardial infarction (MI). Fibrinolytic therapy fails to restore TIMI 3 flow within 90 minutes in 40% to 50% of patients. Because the results of percutaneous coronary intervention (PCI) for MI seem to be improving, a reevaluation of the role of PCI after fibrinolytic therapy for MI appears to be warranted. METHODS AND RESULTS: Data from all 9 randomized controlled trials (including new data from 4 trials) of rescue percutaneous transluminal coronary angioplasty (PTCA) versus conservative therapy after fibrinolytic therapy (1456 patients), 4 contemporary registries of PCI in this setting (977 patients), and other germane studies are reviewed. PTCA after failed fibrinolysis (TIMI 0 to 1 flow) appears to reduce early severe heart failure (3. 8% vs 11.7%, P =.04) and improve survival over 1 year in patients with moderate to large MI (92% vs 87%, P =.001) and possibly reduces early repeat MI (4.3% vs 11.3%, P =.08). Assessment of the possible benefit of PTCA for TIMI 2 flow is hampered by the small number of patients randomly assigned. Repeat MI may be decreased and left ventricular functional recovery enhanced. PTCA early after successful fibrinolysis is nearly always technically successful and may reduce repeat MI and hospital length of stay. However, it must be recalled that randomized trials from the 1980s suggested increased mortality rates with PTCA after restoration of TIMI 2 to 3 flow with fibrinolysis. Data from contemporary randomized studies of stents and glycoprotein IIb/IIIa inhibitors suggest that PCI as performed today may yield better results than those reviewed. CONCLUSIONS: These data suggest a probable benefit of rescue PTCA in several distinct scenarios and that the pivotal mid-1980s studies suggesting no benefit or harm for PTCA after fibrinolytic therapy may no longer be relevant. The role of mechanical intervention in the treatment of patients treated in these settings should be reassessed.

Clinical and angiographic follow-up after single long GFX coronary stent implantation.

In order to identify predictors of late restenosis after GFX stent implantation, procedural and 6-month clinical and angiographic follow-up data of prospectively entered 141 consecutive lesions treated with a single long (24 or 30 mm) GFX stent were compared to 66 consecutive lesions requiring a single short (12 or 18 mm) stent. The initial clinical success rate of 97% and thrombosis rate of 1.4% with long stents were similar to 97% and 0% with short stents (P = NS). Their respective binary restenosis rates were 34.7% and 23.3% for long and short stents as a whole (P = NS), but being 10.0% for 12 mm, 26.0% for 18 mm, 31.3% for 24 mm, and 39.2% for 30 mm. When proximal and distal reference diameters at baseline were compared between the lesions with and without restenosis, proximal reference diameters were not statistically different (3.02+/-0.42 mm vs. 3.18+/-0.62 mm) and the restenosis group had significantly smaller distal reference diameters (2.15+/-0.48 mm vs. 2.55+/-0.53 mm, P<0.0001). The treatment of long lesions with single long-stent implantation can be accomplished with high success and low complication rates. Single long-stent implantation may be effective, if the distal reference size of the long narrowing is big enough to accept the stent.

Ten-years clinical follow-up following successful percutaneous transvenous mitral commissurotomy: single-center experience.

The purpose of this study is to report the long-term follow-up outcome of patients undergoing percutaneous transvenous mitral commissurotomy (PTMC). The follow-up of 68 of 82 (83%) consecutive patients undergoing successful PTMC (mitral valve area of more than 1.5 cm(2) without major complications) in 1987 using the Inoue balloon was analyzed. The mean age at the time of PTMC was 52 +/- 11 years and 81% were female patients. The mean follow-up interval was 98 +/- 37 months (6 to 123). Actuarial survival rate was 98%, 97%, and 86% at 1, 5, and 10 years, respectively; the event-free (death, mitral valve replacement, and repeat PTMC) survival rate was 90%, 85%, and 66% at 1, 5, and 10 years, respectively. According to the echocardiographic findings, patients could be divided into three groups: pliable valve, semipliable valve, and rigid valve. Multivariable analysis identified echocardiographic subgrouping as the major significant predictor of any event: the event-free survival rate being 70% in group 1, 66% in group 2, and 20% in group 3 (P < 0.05). Echocardiographic follow-up was available in 49 of 68 patients (72%); the mitral valve area changed from 1.4 +/- 0.5 before to 2.1 +/- 0.4 immediately post-PTMC, and 1.8 +/- 0.4 cm(2) 10 years after the procedure. The long-term follow-up outcome following successful PTMC was favorable and seems to support it as a viable alternative to surgical commissurotomy in selected patients. Patients with rigid valves should be selected very carefully.

Preintervention lesion remodelling affects operative mechanisms of balloon optimised directional coronary atherectomy procedures: a volumetric study with three dimensional intravascular ultrasound.

AIMS: To classify atherosclerotic coronary lesions on the basis of adequate or inadequate compensatory vascular enlargement, and to examine changes in lumen, plaque, and vessel volumes during balloon optimised directional coronary atherectomy procedures in relation to the state of adaptive remodelling before the intervention. DESIGN: 29 lesion segments in 29 patients were examined with intravascular ultrasound before and after successful balloon optimised directional coronary atherectomy procedures, and a validated volumetric intravascular ultrasound analysis was performed off-line to assess the atherosclerotic lesion remodelling and changes in plaque and vessel volumes that occurred during the intervention. Based on the intravascular ultrasound data, lesions were classified according to whether there was inadequate (group I) or adequate (group II) compensatory enlargement. RESULTS: There was no significant difference in patient and lesion characteristics between groups I and II (n = 10 and 19), including lesion length and details of the intervention. Quantitative coronary angiographic data were similar for both groups. However, plaque and vessel volumes were significantly smaller in group I than in II. In group I, 9 (4)% (mean (SD)) of the plaque volume was ablated, while in group II 16 (11)% was ablated (p = 0.01). This difference was reflected in a lower lumen volume gain in group I than in group II (46 (18) mm(3) v 80 (49) mm(3) (p < 0.02)). CONCLUSIONS: Preintervention lesion remodelling has an impact on the operative mechanisms of balloon optimised directional coronary atherectomy procedures. Plaque ablation was found to be particularly low in lesions with inadequate compensatory vascular enlargement.