Spontaneous coronary artery dissection mimicking coronary spasm diagnosed by intravascular ultrasonography.

Spontaneous coronary artery dissection (SCAD) is a rare and occasionally life-threatening cause of acute coronary syndrome. Patients may present with clinical scenarios ranging from angina pectoris to cardiogenic shock to sudden cardiac death, and it may be a potentially life-threatening condition if not recognized. However, its etiology, pathophysiology and optimal therapeutic strategies have not been well understood. SCAD is diagnosed on the basis of coronary angiography, but complementary techniques as such intravascular ultrasound (IVUS) and optical coherence tomography should be considered for diagnostic clarification where appropriate. Likewise, the selection of treatment strategy depends upon the clinical manifestation, location and the extent of dissection and amount of ischemic myocardium at risk. Herein, we present the case of a 35-year-old woman who presented with acute myocardial infarction. She was diagnosed by IVUS with spontaneous diffuse dissection of the left anterior descending artery without atheroma, treated with percutaneous coronary stenting, and had a favorable clinical course and was discharged on medical therapy.

Quantitative assessment of aortic elasticity with aging using velocity-vector imaging and its histologic correlation.

OBJECTIVE: Velocity-vector imaging (VVI) represents a valuable new method for noninvasive quantification of vascular properties associated with aging. The purpose of this study was to assess the correlations between VVI parameters and histological changes with aging. APPROACH AND RESULTS: Fourteen mongrel dogs were classified as either young (n=7; age, 1-2 years; female; weighing 22-29 kg) or senescent (n=7; age, 8-12 years; female; weighing 36-45 kg). The short-axis image of the descending thoracic aorta was obtained for VVI analysis with transesophageal echocardiography. The location of the image was identified using fluoroscopic guidance, and the aortic tissue was extracted. After dividing the aortic wall into 6 segments, both regional and segmental tissue collagen and elastin contents were quantified and correlated with the aortic elastic properties. In the regional analysis, the M-mode-derived aortic dimensions and elastic moduli except for intima-media thickness were not significantly different between the groups, whereas the VVI-derived aortic area and fractional area changes showed more dilated and stiffer aorta in senescent dogs. Also, fractional area change was significantly correlated with the tissue collagen content unlike the M-mode-derived elastic moduli. In the segmental analysis, the radial velocity, circumferential strain, and strain rates of VVI were more reduced in senescent dogs than young dogs, and the radial velocity and circumferential strain showed independent associations with the collagen content of the corresponding aortic wall. CONCLUSIONS: VVI was a feasible method for direct quantification of aortic elastic properties with a significant histological correlation.

C-reactive protein induces p53-mediated cell cycle arrest in H9c2 cardiac myocytes.

C-reactive protein (CRP) is one of the most important biomarker for cardiovascular diseases. Recent studies have shown that CRP affects cell survival, differentiation and apoptosis. However, the effect of CRP on the cell cycle has not been studied yet. We investigated the cell cycle alterations and cellular mechanisms induced by CRP in H9c2 cardiac myocytes. Flow cytometry analysis showed that CRP-treated H9c2 cells displayed cell cycle arrest in G0/G1 phase. CRP treatment resulted in a significant reduction in the levels of CDK4, CDK6 and cyclin D1 in a concentration-dependent manner. Interestingly, CRP caused an increase in the p53 accumulation and its phosphorylation on Ser15, leading to induce p21 upregulation. Treatment with a specific p53 inhibitor, PFT-α restored the levels of CDK4 and CDK6. A significant increase of ERK1/2 phosphorylation level was detected in CRP-treated cells. Furthermore, pretreatment of a specific ERK inhibitor resulted in decreased p53 phosphorylation and p21 induction. ERK inhibitor pretreatment induced significant restoration of protein levels of CDK4 and CDK6, leading to re-entry into the cell cycle. In addition, increased phosphorylation of p53 and ERK induced by CRP was considerably reversed by Fc gamma receptor IIIa (FcγRIIIa) knock-down using siRNA. FcγRIIIa siRNA transfection also restored the levels of cell cycle proteins. Our study has provided the first proposal on the novel insights into how CRP directly affects cell cycle in cells.

Recurrent dissociation of the tibial insert after mini-subvastus posterior-stabilized total knee arthroplasty: a case report.

We report here on an unusual case of recurrent dissociation of a polyethylene tibial insert from its metal baseplate after high-flex posterior-stabilized (PS) Genesis II total knee arthroplasty with using the mini-subvastus approach. After the 1st episode of dissociation, which had happened 1 month after the primary surgery, we changed the tibial insert and found damages on the dovetails and the post of the retrieved insert. Unfortunately, the patient suffered the same dissociation 1 month after the tibial insert was changed. This case illustrates that incomplete seating of the insert due to limited surgical exposure and anterior impingement of the high-flex PS post may contribute to the risk of dissociation.

Factors affecting patients' graft choice in anterior cruciate ligament reconstruction.

BACKGROUND: Multiple studies have reported that allografts are acceptable alternatives to autografts for anterior cruciate ligament (ACL) reconstructions. Our clinical practice allows patient involvement in graft decision-making. This study examined the patients' preference for graft selection and the factors affecting their decision. METHODS: Patients scheduled to undergo an ACL reconstruction surgery (n = 129) at a university medical center in Korea were enrolled in this study. Information leaflets with graft descriptions were provided prior to hospital admission, and the patients were allowed to choose one of two surgical graft types. The patients were asked to complete a questionnaire that reflected their decision-making processes, and the patients' trends and factors affecting their choice of graft were analyzed based on their responses. RESULTS: Most patients (54.3%) selected autografts for the ACL reconstruction. The surgeon's explanation was the most important factor affecting the final patient decision followed by the information derived from Internet searches. Patients who derived the majority of their understanding of the graft types from the Internet chose allografts at significantly higher rates. CONCLUSIONS: Patient graft selection is a reasonable way of designating the type of surgical procedure. Most patients selected autografts for their ACL reconstruction. However, patients who performed significant Internet-based research tended to prefer allografts.

Inter- and intra-observer variability of a cervical OPLL classification using reconstructed CT images.

BACKGROUND: The lateral radiograph-based system described by Tsuyama is used widely to classify ossification of the posterior longitudinal ligament (OPLL) of the cervical spine. However, OPLL is a complex 3-dimensional (3-D) lesion, not a simple and uniplanar one, which is often difficult to identify on a lateral radiograph. Furthermore, its reliability among spine surgeons has not been investigated. Given the popularity of a reconstructed computed tomography (CT), this study examined the inter- and intra-observer reliability of lateral radiograph-based OPLL classification using that modality. METHODS: Five spine surgeons independently reviewed the lateral radiograph, axial CT, 2-D (sagittal) and 3-D reconstructed CT images of 108 OPLL patients on 2 separate occasions. Based on these images, the reviewers classified each OPLL case according to the Tsuyama's system. The kappa values were used to assess the statistical reliability. RESULTS: The inter- and intra-observer kappa values were only 0.51 and 0.67 for the lateral radiograph, even in combination with the axial CT images, 0.70 and 0.85 for 2-D CT images, and 0.76 and 0.86 for 3-D CT images, respectively. These kappa values showed a good-to-excellent range for the 2-D and 3-D reconstructed CT images while those of the lateral radiograph indicated a fair range. According to the OPLL types, the inter- and intra-observer reliability was low in the continuous type and high in the circumscribed type on the lateral radiograph. However, the low reliability of the continuous type on lateral radiograph was overcome somewhat using 2-D and 3-D reconstructed CT images. CONCLUSIONS: The inter- and intra-observer kappa values were only 0.51 and 0.67 for the lateral radiograph, even in combination with the axial CT images, 0.70 and 0.85 for 2-D CT images, and 0.76 and 0.86 for 3-D CT images, respectively. These kappa values showed a good-to-excellent range for the 2-D and 3-D reconstructed CT images while those of the lateral radiograph indicated a fair range. According to the OPLL types, the inter- and intra-observer reliability was low in the continuous type and high in the circumscribed type on the lateral radiograph. However, the low reliability of the continuous type on lateral radiograph was overcome somewhat using 2-D and 3-D reconstructed CT images.

Effect of hyperglycemia on apoptosis of notochordal cells and intervertebral disc degeneration in diabetic rats.

OBJECT: Diabetes mellitus is thought to be an important etiologic factor in intervertebral disc degeneration. It is known that notochordal cells gradually disappear from the nucleus pulposus (NP) of the intervertebral disc with age by undergoing apoptosis. What is not known is whether diabetes has an effect on apoptotic rates of notochordal cells. The purpose of this study was to investigate the effect of hyperglycemia on apoptosis of notochordal cells and intervertebral disc degeneration in age-matched OLETF (diabetic) and LETO (control) rats. METHODS: Lumbar disc tissue (L1-2 through L5-6), including cranial and caudal cartilaginous endplates, was obtained from 6- and 12-month-old OLETF and LETO rats (40 rats, 10 in each of the 4 groups). The authors examined the NP using TUNEL, histological analysis, and Western blot for expression of matrix metalloproteinase (MMP)-1, -2, -3, and -13, tissue inhibitor of metalloproteinase (TIMP)-1 and -2, and Fas (apoptosis-related protein). The apoptosis index of notochordal cells was calculated. The degree of transition of notochordal NP to fibrocartilaginous NP was classified on a scale ranging from Grade 0 (no transition) to Grade 4 (transition > 75%). The degree of expression of MMP-1, -2, -3, and -13, TIMP-1 and -2, and Fas was evaluated by densitometry. RESULTS: At 6 and 12 months of age, OLETF rats showed increased body weight and abnormal 2-hour glucose tolerance tests compared with LETO rats. The apoptosis index of notochordal cells was significantly higher in the OLETF rats than in the LETO rats at both 6 and 12 months of age. The degree of transition of notochordal NP to fibrocartilaginous NP was significantly higher in the OLETF rats than in the LETO rats at 6 and 12 months of age. The expression of MMP-1, -2, -3, and -13, TIMP-1, and Fas was higher in the OLETF rats at 6 and 12 months of age. The expression of TIMP-2 was significantly higher in the OLETF rats than in the LETO rats at 6 months of age, but not at 12. CONCLUSIONS: The findings suggest that diabetes is associated with premature, excessive apoptosis of NP notochordal cells. This results in an accelerated transition of a notochordal NP to a fibrocartilaginous NP, which leads to early intervertebral disc degeneration. It remains to be determined if these premature changes are due to hyperglycemia or some other factors associated with diabetes. Understanding the mechanism by which diabetes affects disc degeneration is the first step in designing therapeutic modalities to delay or prevent disc degeneration caused by diabetes mellitus.

Serum Levels of TGF-beta1, TIMP-1 and TIMP-2 in Patients with Lumbar Spinal Stenosis and Disc Herniation.

STUDY DESIGN: The serum levels of transforming growth factor-beta 1 (TGF-beta1), tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) and TIMP-2 were measured by enzyme-linked immunosorbent assay. PURPOSE: To compare the serum levels of TGF-beta1, TIMP-1 and TIMP-2 between patients with lumbar spinal stenosis and disc herniation. OVERVIEW OF LITERATURE: It has been reported that increased concentrations of TGF-beta1, TIMP-1 and TIMP-2 in the ligamentum flavum might be a possible pathogenesis for ligamentum flavum hypertrophy in spinal stenosis. However, it is not determined whether this phenomenon in spinal stenosis is a local or systemic problem. METHODS: The concentrations of TGF-beta1, TIMP-1 and TIMP-2 were quantitatively analyzed by ELISA in the ligamentum flavum and serum of patients with lumbar spinal stenosis (n=16) and disc herniation (n=16). The thickness of ligamentum flavum was measured on axial T1-weigted magnetic resonance image. The biochemical and radiological results were compared for the two conditions. RESULTS: The thickness of the ligamentum flavum was larger in patients with spinal stenosis compared with that with disc herniation (p=0.001). The mean concentrations of TGF-beta1, TIMP-1, and TIMP-2 in the ligamentum flavum were significantly higher in patients with spinal stenosis than those with disc herniation (all, p < 0.05). However, the difference in serum levels of TGF-beta1 (p=0.464), TIMP-1 (p=0.146) and TIMP-2 (p=0.794) was not significant between the lumbar spinal stenosis and disc herniation patients. CONCLUSIONS: Despite increased levels of TGF-beta1, TIMP-1, and TIMP-2 in the ligamentum flavum of spinal stenosis patients compared to disc herniation patients, the serum levels of TGF-beta1, TIMP-1 and TIMP-2 were very similar in both groups. These results indicate that the role of TGF-beta1, TIMP-1 and TIMP-2 on hypertrophy of the ligamentum flavum in spinal stenosis patients is a local phenomenon, not systemic.