Effect of short stem alignment on initial fixation, stress transfer, and failure risk.

BACKGROUND: Short stems are advantageous for revision as they preserve autogenous bone. At present, the method of short-stem installation is determined based on the surgeon's experience. OBJECTIVE: To provide the guideline for installing a short stem, we aimed to investigate the alignment effect on the initial fixation of the stem, stress transfer, and the risk of failure numerically. METHODS: Models in which the caput-collum-diaphyseal (CCD) angle and flexion angle were hypothetically changed based on the two clinical cases of hip osteoarthritis were analyzed using the non-linear finite element method. RESULTS: The medial settlement of the stem increased in the varus model and decreased in the valgus model. With varus alignment, the stresses acting on the femur were high in the distal to the femoral neck. In contrast, the stresses in the proximal to the femoral neck tend to be higher with valgus alignment, although the difference in the femur stress between varus and valgus alignment was slight. CONCLUSION: Both initial fixation and stress transmission are lower when the device was placed in the valgus model than in the actual surgical case. In order to obtain initial fixation and suppress stress shielding, it is essential to extend the contact area between the medial portion of the stem and the femur along the bone axis, and to ensure adequate contact between the lateral portion of the stem tip and the femur.

Clustering of metabolic syndrome components attenuates coronary plaque regression during intensive statin therapy in patients with acute coronary syndrome: the JAPAN-ACS subanalysis study.

BACKGROUND: The JAPAN-ACS (Japan Assessment of Pitavastatin and Atorvastatin in Acute Coronary Syndrome) trial showed that intensive statin therapy could induce significant coronary plaque regression in acute coronary syndrome (ACS). We evaluated the impact of metabolic syndrome (MetS) and its components on coronary plaque regression in the JAPAN-ACS patients. METHODS AND RESULTS: Serial intravascular ultrasound measurements over 8-12 months were performed in 242 ACS patients receiving pitavastatin or atorvastatin. Patients were divided into groups according to the presence of MetS or the number of MetS components. Although the percent change in plaque volume (%PV) was not significantly different between the MetS (n=119) and non-MetS (n=123) groups (P=0.50), it was significantly associated with an increasing number of MetS components (component 0: -24.0%, n=7; components 1: -20.8%, n=31; components 2: -16.1%, n=69; components 3: -18.7%, n=83; components 4: -13.5%, n=52; P=0.037 for trend). The percent change in body mass index (%BMI) significantly correlated with %PV (r=0.15, P=0.021), especially in the MetS components 4 group (r=0.35, P=0.017). In addition, %BMI was an independent predictor of plaque regression after adjustment for the changes of low- and high-density lipoprotein cholesterol, triglycerides and HbA(1c). CONCLUSIONS: The clustering of MetS components, but not the presence of MetS itself, could attenuate coronary plaque regression during intensive statin therapy in ACS patients. Therefore, to achieve a greater degree of plaque regression, it is necessary to treat to each MetS component and use lifestyle modification.

ME3738 enhances the effect of interferon and inhibits hepatitis C virus replication both in vitro and in vivo.

BACKGROUND & AIMS: ME3738 (22ß-methoxyolean-12-ene-3ß, 24-diol), a derivative of soyasapogenol B, attenuates liver disease in several animal models of acute and chronic liver injury. ME3738 is thought to inhibit replication of hepatitis C virus (HCV) by enhancing interferon (IFN)-ß production, as determined using the HCV full-length binary expression system. We examined the effect of ME3738 combined with IFN-α on HCV replication using the genotype 1b subgenomic replicon system and an in vivo mouse HCV model. METHODS: HCV replicon cells (ORN/3-5B/KE cells and Con1 cells) were incubated with ME3738 and/or IFN-α, and then intracellular IFN-stimulated genes (ISGs) and HCV RNA replication were analyzed by reverse-transcription-real time polymerase chain reaction and luciferase reporter assay. HCV-infected human hepatocyte chimeric mice were also treated with ME3738 and/or IFN-α for 4 weeks. Mouse serum HCV RNA titer, HCV core antigen, and ISGs expression in the liver were measured. RESULTS: ME3738 induced gene expression of oligoadenylate synthetase 1 and inhibited HCV replication in both HCV replicon cells. The drug enhanced the effect of IFN to significantly increase ISG expression levels, inhibit HCV replication in replicon cells, and reduce mouse serum HCV RNA and core antigen levels in mouse livers. The combination treatment was not hepatotoxic as evident histologically and did not reduce human serum albumin in mice. CONCLUSIONS: ME3738 inhibited HCV replication, enhancing the effect of IFN-α to increase ISG expression both in vitro and in vivo, suggesting that the combination of ME3738 and IFN might be useful therapeutically for patients with chronic hepatitis C.

Inheritance and alteration of genome methylation in F1 hybrid rice.

We analyzed the inheritance of DNA methylation in the first filial generation(F1) hybrid of Oryza sativa L. ("Nipponbare"x"Kasalath") by restriction landmark genome scanning (RLGS). Most parental RLGS spots were found in the F1, but eight spots (4%) showed abnormal inheritance: seven of the eight spots were missing in the F1, and one was newly detected in the F1. Here we show demethylation at restriction enzyme sites in the F1. We also found a candidate site of stable heterozygous methylation in the genome. These results show the applicability of the RLGS method for analysis of the inheritance and alteration of methylation in F1 hybrid plants.

Impact of lipid-lowering therapy with pitavastatin, a new HMG-CoA reductase inhibitor, on regression of coronary atherosclerotic plaque.

BACKGROUND: Recent lipid-lowering trials have reported that statin therapy may retard progression or stimulate regression of human coronary plaque. In the present study volumetric intravascular ultrasound (IVUS) analyses were performed to investigate the effect of pitavastatin, a newly developed statin, on regression of human coronary plaque. METHODS AND RESULTS: Eighty-two patients matched for age and gender from 870 consecutive patients undergoing IVUS guided percutaneous coronary intervention were retrospectively assigned to either lipid-lowering therapy (n=41; pitavastatin 2 mg/day) or control group (n=41; diet only). Serial volumetric IVUS analyses of a matched left main coronary arterial site were performed. A significant reduction in low-density lipoprotein-cholesterol (LDL-C) level of 33.2% (p<0.001) was observed in the pitavastatin group. Plaque volume index (PVI) was significantly reduced in the pitavastatin group (10.6+/-9.4% decrease) compared with the control group (8.1+/-14.0% increase, p<0.001). There were positive correlations between the percent change in the PVI and follow-up LDL-C level (r=0.500, p<0.001) and the percent change in LDL-C level (r=0.479, p<0.001). CONCLUSION: Lipid-lowering therapy with pitavastatin induced significant coronary plaque regression, associated with a significant reduction in the LDL-C level. The percent change in the PVI showed a significant positive correlation with the percent change in LDL-C level.

[Regression of a large lipid-rich pool in the coronary artery during treatment with statin detected by intravascular ultrasound: a case report].

A 54-year-old man with unstable angina presented with severe stenosis of the middle segment of the left anterior descending coronary artery. Percutaneous coronary stent implantation and serial intravascular ultrasound (IVUS) were performed. IVUS detected a non-culprit coronary plaque with a large lipid-rich pool in the proximal segment of the left anterior descending coronary artery. Atorvastatin 10 mg/day was given to reduce his cholesterol level for 2 years after the stent implantation. This patient had no cardiac events, and the low-density lipoprotein-cholesterol level reduced from 171 to 88 mg/dl at follow-up. Two-year follow-up IVUS examination revealed the reduction of plaque burden associated with regression of the lipid-rich pool size. This case may indicate that statin could contribute to the regression of lipid-rich plaque and to the stability of coronary plaque.

Restriction landmark genome scanning method using isoschizomers (MspI/HpaII) for DNA methylation analysis.

Restriction landmark genome scanning (RLGS) is a 2-DE of genomic DNA, which visualizes thousands of loci. In a conventional RLGS method for methylation analysis, we have used a methylation sensitive restriction enzyme, NotI as a landmark. However, it was unable to discriminate methylation polymorphism from sequence polymorphism. Here, we report an improved RLGS method to detect methylated sites directly. We employed isoschizomers, MspI and HpaII, that recognize the same sequence (CCGG) but have different methylation sensitivity. We carried out the RLGS analysis of Arabidopsis thaliana ecotype Columbia, and obtained a pair of spot patterns with MspI and HpaII. We detected 22 spots in both patterns. In comparison of them, 18% of the spots were polymorphic, which indicated the methylation of C(5m)CGG sites. Further analyses revealed an additional methylated site of NotI. Moreover, 52 and 54 restriction enzyme sites were also analyzed in two other ecotypes, Wassilewskija and Landsberg erecta, respectively. Consequently, 15% of the 52 common sites showed methylation polymorphism among the three ecotypes. The restriction sites analyzed in this study were located in or near genes, and contribute new data about the correlation between methylation status and gene expression. Therefore, this result strongly indicates that the improved RLGS method is readily applicable to practical analyses of methylation dynamics, and provides clues to the relationship between methylation and gene expression.

Pharmacological characterization and feeding-suppressive property of FMS586 [3-(5,6,7,8-tetrahydro-9-isopropyl-carbazol-3-yl)-1-methyl-1-(2-pyridin-4-yl-ethyl)-urea hydrochloride], a novel, selective, and orally active antagonist for neuropeptide Y Y5 receptor.

We evaluated the pharmacological profiles of FMS586 [3-(5,6,7,8-tetrahydro-9-isopropyl-carbazol-3-yl)-1-methyl-1-(2-pyridin-4-yl-ethyl)-urea hydrochloride], a novel tetrahydrocarbazole derivative as a neuropeptide Y (NPY) Y5 receptor antagonist. This compound showed a highly selective in vitro affinity for Y5 (IC(50) = 4.3 +/- 0.4 nM) relative to other NPY receptor subtypes like Y1 or Y2. Its binding to Y5 was found to be fully antagonistic from cyclic AMP accumulation assays in human embryonic kidney 293 cells. Pharmacokinetic analysis revealed sufficient oral availability and brain permeability of this compound accompanied with clear dose relation. We attempted to assess the selectivity of FMS586 and, thereby, to infer the physiological role of Y5 in the following feeding experiments in normal rats. An intracerebroventricular injection of NPY and Y5-selective agonist peptide induced acute and robust feeding responses in satiated rats, and prior administration of FMS586 at the doses from 25 to 100 mg/kg clearly inhibited these responses by approximately 55 and 90%, respectively. This compound also showed dose-dependent but transient suppression in natural feeding models of both overnight fasting-induced hyperphagia and spontaneous daily intake. FMS586 did not modulate food intake induced by the topical injection of norepinephrine, galanin, or gamma-aminobutyric acid receptor agonist muscimol to the paraventricular nucleus. In addition, we confirmed the Y5-specific activity profile of FMS586 by immunohistochemical analysis. Taken together, we propose not only that our compound potentially expresses specific blockade of central Y5 signals but also that Y5 receptor would certainly contribute to physiological regulation of food intake in normal rats, as suggested from its origin.

Effect of pacing mode on sleep disturbance.

The relationship between pacing mode and sleep is not yet known, and therefore polysomnography was used to evaluate the effect. A total of 16 patients (8 men and 8 women; mean age, 72 +/- 9 years) with DDD pacemakers made up the study population. Of these 16 patients, 8 patients had complete AV block and 8 patients had sick sinus syndrome. The recording was done twice in VVI and DDD modes. Between VVI mode and DDD mode, sleep latency time (VVI mode: 38 +/- 25, DDD mode 23 +/- 27 min), frequency of temporary waking (8.3 +/- 6.7, 3.7 +/- 2.9 times), the number of episodes of apnea (59 +/- 84, 36 +/- 55 times, the apnea-hypopnea index (AHI) (15 +/- 18, 10 +/- 13), and efficacy of sleep (72% +/- 10%, 81% +/- 11%) were significantly different. Also, the apnea index improved significantly in DDD mode. There was no significant difference in total sleep time and in total duration of temporary waking between the two groups. From the study results, a reduction in sleep disturbance was achieved when DDD pacing mode was chosen, rather than VVI mode. Furthermore, efficacy of sleep also improved significantly compared with VVI mode. Interestingly, sleep apnea syndrome in four patients with AHI > or = 15 notably ameliorated when DDD mode was chosen; however, the mechanism involved in amelioration is still ambiguous and needs further assessment.

Human group IVC phospholipase A2 (cPLA2gamma). Roles in the membrane remodeling and activation induced by oxidative stress.

To create the unique properties of a certain cellular membrane, both the composition and the metabolism of membrane phospholipids are key factors. Phospholipase A(2) (PLA(2)), with hydrolytic enzyme activities at the sn-2 position in glycerophospholipids, plays critical roles in maintaining the phospholipid composition as well as producing bioactive lipid mediators. In this study we examined the contribution of a Ca(2+)-independent group IVC PLA(2) isozyme (cPLA(2)gamma), a paralogue of cytosolic PLA(2)alpha (cPLA(2)alpha), to phospholipid remodeling. The enzyme was localized in the endoplasmic reticulum and Golgi apparatus, as seen using green fluorescence fusion proteins. Electrospray ionization mass spectrometric analysis of membrane extracts revealed that overexpression of cPLA(2)gamma increased the proportion of polyunsaturated fatty acids in phosphatidylethanolamine, suggesting that the enzyme modulates the phospholipid composition. We also found that H(2)O(2) and other hydroperoxides induced arachidonic acid release in cPLA(2)gamma-transfected human embryonic kidney 293 cells, possibly through the tyrosine phosphorylation pathway. Thus, we propose that cPLA(2)gamma is constitutively expressed in the endoplasmic reticulum and plays important roles in remodeling and maintaining membrane phospholipids under various conditions, including oxidative stress.

[Intravascular ultrasound guided polytetrafluoroethylene coronary stent graft implantation in a patient with a large coronary pseudoaneurysm at eight months after coronary intervention: a case report].

A 67-year-old man with exertional angina presented with a large pseudoaneurysm of the right coronary artery at eight months after balloon angioplasty. Intravascular ultrasound revealed a large saccular pseudoaneurysm of 10.9 x 5.7 mm diameter at the proximal segment of the right coronary artery. Complete closure of the coronary pseudoaneurysm was successfully obtained using a coronary stent graft consisting of a thin flexible polytetrafluoroethylene (PTFE) membrane placed between two stents using a unique sandwich technique. Follow-up angiography and intravascular ultrasound revealed no significant restenosis in the PTFE stent graft segment. PTFE coronary stent graft implantation is a feasible, safe and useful method to treat a large coronary pseudoaneurysm after coronary intervention.