Evaluation of coronary artery calcification by multi-detector row computed tomography for the detection of coronary artery stenosis in Japanese patients

BACKGROUND: The development of an efficient noninvasive examination to detect coronary atherosclerosis is needed as a strategy to prevent coronary heart disease. To evaluate the usefulness of calcium score measured by multi-detector row computed tomography (MDCT), we compared calcium score derived from MDCT with findings of coronary artery stenosis assessed by coronary angiography (CAG). METHODS: In 108 patients (94 men, 14 women; average age, 65.7 years), we performed unenhanced CT scans and calculated coronary artery calcium score in 259 vessels without previous intervention and severe motion artifact to determine the correlation with the degree of coronary stenosis by CAG. RESULTS: The sensitivity and the specificity of calcification (calcium score 0.1+) for severe stenosis (75+%) were 89% and 43%, respectively. All four vessels with calcium score 1000+ had a severe stenosis. The areas under the receiver operating characteristics curve of calcium score for severe stenosis were 0.80 +/- 0.04, indicating the efficacy of this technique. CONCLUSIONS: Coronary artery calcification and calcium score determined by MDCT were associated with coronary arteries with severe stenosis. This technique appears to be useful for the evaluation of coronary atherosclerosis.     

Opposing effects of isoflurane and sevoflurane on neurogenic pulmonary edema development in an animal model

BACKGROUND: The current study was undertaken to investigate the effects of pretreatment with isoflurane and sevoflurane on the development of neurogenic pulmonary edema in an animal model. METHODS: Rats were exposed to room air (control), 1.5% isoflurane, or 2.5% sevoflurane for 4 h. They were then anesthetized with intraperitoneal injections of pentobarbital sodium, and fibrinogen and thrombin were injected into the cisterna magna to induce neurogenic pulmonary edema. RESULTS: Consecutive injections of fibrinogen and thrombin caused increases in blood pressure, with the peak values obtained in the isoflurane and sevoflurane groups being lower than the control values. The incidence of significant neurogenic pulmonary edema was 58%, 100%, and 8% in the control, isoflurane, and sevoflurane groups, respectively. The lung water ratio, an index of severity of edema, was 4.86 +/- 0.78, 6.15 +/- 0.64, and 4.40 +/- 0.32 in the control, isoflurane, and sevoflurane groups, respectively. Furthermore, immunohistochemical staining for vascular endothelial growth factor demonstrated an increase of expression in the rat lungs exposed to isoflurane. Treatment with an anti-vascular endothelial growth factor antibody during exposure to isoflurane completely inhibited the effect of isoflurane to promote neurogenic pulmonary edema in this model. CONCLUSION: Exposure to 1.5% isoflurane enhances the development of neurogenic pulmonary edema development in this animal model, most likely via release of vascular endothelial growth factor from bronchial epithelial cells, an effect not observed with sevoflurane.     

Osteogenic potential of primed periosteum graft in the rat calvarial model

Repair of bone defects remains a major concern in plastic and maxillofacial surgery. Based on modern concepts of tissue engineering, periosteum has gained attention as a suitable osteogenic material. We tested the hypothesis that surgically released and immediately repositioned periosteum would exhibit high osteogenic capacity upon grafting in a rat calvarial defect. Seven days after periosteum was released from the tibia and immediately repositioned, the "primed periosteum graft" (PPG; n = 15) was placed into a critical-sized defect of rat calvaria and the process of bone formation was evaluated histologically, immunohistologically, and radiographically at 7, 14, and 21 days after grafting. Findings were compared with a nonprimed periosteal graft (NPG; n = 15).Endochondral ossification was observed in both the PPG and NPG. The PPG showed higher expression of proliferative cell nuclear antigen, bone morphogenetic protein, and vascular endothelial growth factor than the NPG. Three-dimensional radiographic examination revealed significantly increased bone formation in the PPG than in the NPG (P < 0.01). These findings suggested that surgical stimulation of the periosteum enhanced the osteogenic potential of periosteal cells. This method may be suitable for the clinical repair of bone defects.     

Cerebrospinal fluid neprilysin is reduced in prodromal Alzheimer's disease

Amyloid beta peptide (A beta) has been implicated in Alzheimer's disease (AD) as an initiator of the pathological cascades. Several lines of compelling evidence have supported major roles of A beta-degrading enzyme neprilysin in the pathogenesis of sporadic AD. Here, we have shown a substantial reduction of cerebrospinal fluid (CSF) neprilysin activity (CSF-NEP) in patients with AD-converted mild cognitive impairment and early AD as compared with age-matched control subjects. The altered CSF-NEP likely reflects changes in neuronal neprilysin, since transfer of neprilysin from brain tissue into CSF was demonstrated by injecting neprilysin-carrying viral vector into the brains of neprilysin-deficient mice. Interestingly, CSF-NEP showed an elevation with the progression of AD. Along with a close association of CSF-NEP with CSF tau proteins, this finding suggests that presynaptically located neprilysin can be released into CSF as a consequence of synaptic disruption. The impact of neuronal damages on CSF-NEP was further demonstrated by a prominent increase of CSF-NEP in rats exhibiting kainate-induced neurodegeneration. Our results unequivocally indicate significance of CSF-NEP as a biochemical indicator to pursue a pathological process that involves decreased neprilysin activity and A beta-induced synaptic toxicity, and the support the potential benefits of neprilysin up-regulation in ameliorating neuropathology in prodromal and early AD.     

Radiofrequency ablation of metastatic mediastinal lymph nodes during cooling and temperature monitoring of the tracheal mucosa to prevent thermal tracheal damage: initial experience

Institutional review board approval and patient informed consent were obtained. Radiofrequency ablation in a total of 10 sessions was performed for each mediastinal lymph node metastasis from esophageal cancer that had a mean largest diameter of 2.2 cm +/- 0.6 (standard deviation) in seven male patients (mean age, 59 years). During ablation, cooling and temperature of the tracheal mucosa were monitored in the proper position in eight of the 10 sessions; in the other two sessions, monitoring was not done because of tracheal stenosis (perforation resulted). Three of the four lymph nodes that were 2.0 cm or smaller in largest diameter showed no evidence of local progression for at least 1 year since ablation; all three of the nodes greater than 2.0 cm in largest diameter progressed within 6 months. The 1-year survival rate was 60%; the median survival time was 13 months. Radiofrequency ablation may be effective for local control of small metastatic mediastinal lymph nodes, and cooling and temperature monitoring of the tracheal mucosa in the proper position may prevent thermal tracheal damage.     

Sustained spatial disturbance of bile canalicular networks during regeneration of the steatotic rat liver

BACKGROUND: Although it is generally considered that livers with moderate steatosis can be safely used in the setting of living-donor liver transplantation, the effect of the regenerative process of such a graft on postoperative liver function is incompletely understood. We assessed the morphologic and functional alterations during the regeneration of fatty liver, with special reference to the biliary system. METHODS: Wistar rats with normal or fatty livers induced by a choline-deficient diet were subjected to 70% partial hepatectomy (PH). The regenerated liver weight and serum parameters were compared. Furthermore, to assess the spatial alterations of bile canalicular networks, the distribution of AGp110, a fibronectin receptor that localizes on the apical (bile canalicular) membrane of the hepatocytes, was analyzed immunohistochemically. RESULTS: The serum albumin levels of the fatty-liver rats decreased significantly after 24 hours, and this continued until day 7. The increase in the total bile acid levels of the fatty-liver group was higher and more prolonged compared with that of the normal-liver group. At 24 hours after PH, discontinuity of the AGp110-positive canalicular network was evident in both groups. At 7 days after PH, the typical AGp110-positive canalicular network was almost restored in the normal-liver group. In contrast, the fatty-liver group showed sustained discontinuity of canalicular networks at the same time point. CONCLUSIONS: The livers with moderate steatosis are associated with prolonged cholestasis after 70% PH, and this was caused, in part, by sustained spatial disturbance of bile canalicular networks during the regenerative process.