Myocardial Bridge Bypass Graft: A Novel Surgical Procedure for Extensive Myocardial Bridges.

In patients with myocardial bridges (MBs) and insufficient medical management, the optimal surgical strategy remains undetermined. Based on computer simulations we developed a novel procedure, MB bypass grafting, that showed better hemodynamics compared with coronary artery bypass grafting in a simulation study. In this novel procedure the left internal mammary artery was used to connect the proximal and distal ends of the MB. For the first time we used MB bypass grafting to treat a patient with extensive MB. The patient recovered well after surgery, and the left internal mammary artery graft remained patent 3 months postoperatively.

Lipopolysaccharide impairs permeability of pulmonary microvascular endothelial cells via Connexin40.

The endotoxin lipopolysaccharide (LPS)-induced pulmonary endothelial barrier disruption is a key pathogenesis of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). However, the molecular mechanisms underlying LPS-impaired permeability of pulmonary microvascular endothelial cells (PMVECs) are not fully understood. Gap junctions, particularly Connexin40 (Cx40), are necessary for the maintenance of normal vascular function. In this study, we for the first time investigated the role of Cx40 in LPS-impaired permeability of PMVECs and provided potential therapeutic approaches based on mechanistic findings of Cx40 regulation by LPS stimuli. Rat PMVECs were isolated, cultured and identified with cell morphology, specific markers, ultrastructural characteristics and functional tests. Western blot analysis demonstrated that Cx40 is the major connexin highly expressed in PMVECs. Furthermore, by inhibiting Cx40 in a time-dependent manner, LPS impaired gap junction function and induced permeability injury of PMVECs. The key role of Cx40 decline in mediating detrimental effects of LPS was further confirmed in rescue experiments through Cx40 overexpression. Mechanistically, LPS stress on PMVECs inhibited the protein kinase C (PKC) pathway, which may synergize with the inflammatory nuclear factor kappaB (NFκB) signaling activation in suppressing Cx40 expression level and phosphorylation. Moreover, through pharmacological PKC activation or NFκB inhibition, Cx40 activity in PMVECs could be restored, leading to maintained barrier function under LPS stress. Our findings uncover a previously unrecognized role of Cx40 and its regulatory mechanisms in impaired endothelial integrity under endotoxin and inflammation, shedding light on intervention approaches to improve pulmonary endothelial barrier function in ALI and ARDS.

Macrophage micro-RNA-155 promotes lipopolysaccharide-induced acute lung injury in mice and rats.

Micro-RNA (miR)-155 is a novel gene regulator with important roles in inflammation. Herein, our study aimed to explore the role of miR-155 in LPS-induced acute lung injury(ALI). ALI in mice was induced by intratracheally delivered LPS. Loss-of-function experiments performed on miR-155 knockout mice showed that miR-155 gene inactivation protected mice from LPS-induced ALI, as manifested by preserved lung permeability and reduced lung inflammation compared with wild-type controls. Bone marrow transplantation experiments identified leukocytes, but not lung parenchymal-derived miR-155-promoted acute lung inflammation. Real-time PCR analysis showed that the expression of miR-155 in lung tissue was greatly elevated in wild-type mice after LPS stimulation. In situ hybridization showed that miR-155 was mainly expressed in alveolar macrophages. In vitro experiments performed in isolated alveolar macrophages and polarized bone marrow-derived macrophages confirmed that miR-155 expression in macrophages was increased in response to LPS stimulation. Conversely, miR-155 gain-of-function in alveolar macrophages remarkably exaggerated LPS-induced acute lung injury. Molecular studies identified the inflammation repressor suppressor of cytokine signaling (SOCS-1) as the downstream target of miR-155. By binding to the 3'-UTR of the SOCS-1 mRNA, miR-155 downregulated SOCS-1 expression, thus, permitting the inflammatory response during lung injury. Finally, we generated a novel miR-155 knockout rat strain and showed that the proinflammatory role of miR-155 was conserved in rats. Our study identified miR-155 as a proinflammatory factor after LPS stimulation, and alveolar macrophages-derived miR-155 has an important role in LPS-induced ALI.

[Measuring diet quality of labor workers in Shenzhen using Chinese diet balance index].

OBJECTIVE: To evaluate the overall diet quality and diet model of labor workers in Shenzhen using Chinese Diet Balance Index (DBI). METHODS: In May 2009, 14 canteens from Baoan, Longgang and Nanshan districts were selected by stratified random sampling and 60 workers were randomly selected from each canteen by using random number method. Diet measurements were carried out among the 840 labor workers. Diet quality was evaluated by using DBI scoring and evaluating system. RESULTS: The median values of labor workers' food intakes of cereal and meat & poultry were 483.8 and 121.7 g/d, which were more than the recommended amounts of their intakes of Chinese residents (cereal: 250 - 400 g/d, meat & poultry: 50 -70 g/d). The median values of the labor workers' intakes of fruit, dairy and eggs were 37.3, 20.6 and 23.5 g/d,which were less than recommended amounts in fruits (200 - 400 g/d), dairy (300 g/d) and eggs (25 - 50 g/d). The DBI-HBS scores of males and females in Shenzhen migrant workers were 24.4 +/- 6.1 and 22.6 +/- 6.3, respectively with a statistically significant difference (t = 4.21, P < 0.01). DBI-HBS scores of < 20 age group, 20 - 29 age group, 30 - 39 age group and > or = 40 age group in labor workers were 12.7 +/- 5.9, 11.3 +/- 6.3, 12.8 +/- 6.4 and 11.2 +/- 5.6 respectively (F = 3.67, P = 0.01). There were 7 dietary patterns among labor workers in this survey. Nearly 8.2% (68/830) of them belonged to Pattern A. Pattern B and E were the main dietary patterns, which accounted for 37.3% (310/830) and 31.0% (257/830) of the total population. CONCLUSION: DBI can describe and evaluate the overall dietary quality and the major problem of the dietary patterns in labor workers. It is necessary to strength nutritional education to increase the intake of fruits, milk and eggs to improve nutritional status in labor workers in Shenzhen.

Vardenafil ameliorates calcium mobilization in pulmonary artery smooth muscle cells from hypoxic pulmonary hypertensive mice.

BACKGROUND AND AIMS: Vardenafil has been found to be potent in pulmonary hypertension; however, the underlying mechanisms remain poorly understood. To address this issue, we investigated the underlying mechanisms of vardenafil in the contribution of Ca(2+) signaling and mobilization in modifying vasoconstriction of pulmonary arteries in hypoxic mice. METHODS: Hemodynamic measurements and morphological studies were performed. Muscle tension was measured by PowerLab system. I(Ca,L) was recorded using a perforated patch-clamp technique. [Ca(2+)](i) was measured using a fluorescence imaging system. RESULTS: Vardenafil greatly inhibited RVSP increases, RV hypertrophy and ameliorated pulmonary artery remodeling in response to chronic hypoxia. Membrane depolarization following 50 mM high K(+)-caused muscle contraction significantly decreased from 101.7 ± 10.1 in the hypoxia group to 81.8 ± 5.0 mg in hypoxia plus vardenafil arteries. Fifty mM high K(+)-elicited increase [Ca(2+)](i) was markedly decreased from 610.6 ± 71.8 in hypoxia cells to 400.3 ± 47.2 nM in hypoxia plus vardenafil cells. Application of vardenafil greatly inhibited the density of I(Ca,L) by 37.7% compared with that in the hypoxia group. Administration of 1 µM phenylephrine to stimulate α(1)-adrenergic receptor resulted in a smaller increase in [Ca(2+)](i) in hypoxia plus vardenafil cells than that in hypoxia cells. One hundred µM ATP-mediated increase in [Ca(2+)](i) was also inhibited in vardenafil-hypoxia group (from 625.8 ± 62.3 to 390.9 ± 38.1 nM), suggesting that internal calcium reserves contribute to neurotransmitter-induced Ca(2+) release from the SR through IP(3)Rs in PASMCs. CONCLUSIONS: Vardenafil may effectively block Ca(2+) influx through L-type Ca(2+) channel and inhibit the Ca(2+) release from SR through IP(3)Rs, thus enhancing its vasorelaxation of pulmonary arteries under hypoxia conditions.

Deletion of RBP-J in adult mice leads to the onset of aortic valve degenerative diseases.

Transcription factor RBP-J-mediated Notch signaling has been implicated in several inherited cardiovascular diseases including aortic valve diseases (AVD). But whether Notch signal plays a role in AVD in adults has been unclear. This study aims to test whether the deletion of RBP-J in adult mice would lead to AVD and to investigate the underlying mechanisms. Cre-LoxP-mediated gene deletion was employed to disrupt Notch signal in adult mice. Immunofluorescence and electron microscope observations showed that deletion of RBP-J in adult mice led to early morphological changes of AVD. The size of aortic valve was enlarged. The endothelial homeostasis was perturbed, probably due to the up-regulation of VEGFR2. The endothelial cells exhibited increased proliferation and loose endothelial junctions. The valvular mesenchyme displayed significant fibrosis, consistent with the up-regulation of TGF-ß1 and activation of endothelial-mesenchymal transition. We observed melanin-producing cells in aortic valves. The number of melanin-producing cells increased significantly, and their location changed from the mesenchyme to subendothelial layer of valve cusps in RBP-J deficient mice. These results suggest that RBP-J-mediated Notch signaling in aortic valves may be critically involved in valve homeostasis and valve diseases as well. These findings will be helpful for the understanding of the molecular mechanisms of AVD in adults.

Combined interventional and surgical treatment for acute aortic type a dissection.

Surgical repair and endovascular stent-graft placement are both therapies for thoracic aortic dissection. A combination of these two approaches may be effective in patients with type A dissection. In this study, we evaluated the prognosis of this combined technique. From December 2003 to December 2006, 15 patients with type A dissection were admitted to our institute; clinical data were retrospectively reviewed. Follow-up was performed at discharge and approximately 12 months after operation. Endovascular stent-graft placement by interventional radiology and surgical repair for reconstruction of aortic arch was performed in all patients. Total arch replacement for distal arch aneurysm was carried out under deep hypothermia with circulatory arrest; antegrade-selected cerebral perfusion was used for brain protection. Four patients concomitantly received a coronary artery bypass graft. Hospital mortality rate was 6.7%; the patient died of cerebral infarction. Neurological complications developed in two patients. Multi-detector-row computed tomography scans performed before discharge revealed complete thrombosis of the false lumen in six patients and partial thrombosis in eight patients. At the follow-up examination, complete thrombosis was found in another three patients, aortic rupture, endoleaks, or migration of the stent-graft was not observed and injuries of peripheral organs or anastomotic endoleaks did not occur. For patients with aortic type A dissection, combining intervention and surgical procedures is feasible, and complete or at least partial thrombosis of the false lumen in the descending aorta can be achieved. This combined approach simplified the surgical procedures and shortened the circulatory arrest time, minimizing the necessity for further aortic operation.

Combined interventional and surgical treatment for acute aortic type a dissection.

BACKGROUND: Surgical repair and endovascular stent-graft placement are both therapies for thoracic aortic dissection. A combination of these two approaches may be effective in patients with type A dissection. In this study, we evaluated the prognosis of this combined technique. METHODS: From December 2003 to December 2006, 15 patients with type A dissection were admitted to our institute; clinical data were retrospectively reviewed. Follow-up was performed at discharge and approximately 12 months after operation. RESULTS: Endovascular stent-graft placement by interventional radiology and surgical repair for reconstruction of aortic arch was performed in all patients. Total arch replacement for distal arch aneurysm was carried out under deep hypothermia with circulatory arrest; antegrade-selected cerebral perfusion was used for brain protection. Four patients concomitantly received a coronary artery bypass graft. Hospital mortality rate was 6.7%; the patient died of cerebral infarction. Neural complications developed in two patients. Multi-detector-row computed tomography scans performed before discharge revealed complete thrombosis of the false lumen in six patients and partial thrombosis in eight patients. At the follow-up examination, complete thrombosis was found in another three patients, aortic rupture, endoleaks or migration of the stent-graft was not observed and injuries of peripheral organs or anastomotic endoleaks did not occur. CONCLUSIONS: For patients with aortic type A dissection, combining intervention and surgical procedures is feasible, and complete or at least partial thrombosis of the false lumen in the descending aorta can be achieved. This combined approach simplified the surgical procedures and shortened the circulatory arrest time, minimizing the necessity for further aortic operation.

Is left ventriculotomy feasible for muscular ventricular septal defects in infants?

Optimal management of muscular ventricular septal defects (MVSDs) remains controversial. Left ventriculotomy is the cornerstone of surgical repair but is frequently complicated by residual shunts, left ventricular dysfunction, apical aneurysm, or arrhythmias. In this study, we evaluated the long-term outcomes of surgical repairs in infants with isolated MVSDs. We retrospectively analyzed clinical data from 56 children with MVSDs (31 males, 25 females). Follow-up by questionnaire and Doppler echocardiography was performed at discharge and between 2 and 124 months after surgery. Patient age was 2 to 40 months (median, 21 months) and weight was 3.0 to 15.3 kg (median, 5.3 kg). Two patients died after surgery (hospital mortality, 3.57%). One patient with MVSDs died of low cardiac output caused by the long duration of cardiopulmonary bypass. Another patient with Swiss cheese MVSD received a single patch closure but died of low cardiac output immediately after cardiopulmonary bypass. Immediate complications such as a third-degree atrial-ventriclar block occurred in 2 patients, but they recovered before discharge and showed no residual shunt. No deaths occurred during follow-up, but a residual shunt was found in 1 patient. Delayed complete heart block requiring a pacemaker occurred in 1 patient. One patient showed paroxysmal supraventricular tachycardia that was treated with amiodarone. The left ventricular ejection fraction was 0.45-0.55 in 8 patients and 0.55-0.73 in 46 patients. No apical aneurysm was found. All the surviving patients returned to normal school life. Our results indicate that surgery is a suitable treatment option in infants and children with isolated MVSDs and that preoperative diagnosis is crucial to a successful outcome. Infants can tolerate a left ventriculotomy incision for MVSDs in the lower or apical ventricular septum.

Immune responses to trichloroethylene and skin gene expression profiles in Sprague Dawley rats.

OBJECTIVE: To characterize the immune reaction in SD rats exposed to trichloroethylene (TCE) and to identify the gene expression profiles involved in skin after TCE exposure. METHODS: Fifteen percent of TCE was injected intradermally into the rat back (100 microL/120 g) at intervals of 7 days. Whole blood was collected 24 h after the fifth or seventh intradermic administration of TCE. The percentages of CD4+ and CD8+ of T lymphocytes were measured by a flow cytometer. The concentrations of IFN-gamma and IL-4 in the serum were semi-quantified by ELISA. Total RNAs of skin samples at 3 h or 24 h after the seventh dose of TCE in SD rats were extracted, and gene expression profiles of these tissues were analyszed by rat toxicology U34 array of Affymetrix. RESULTS: Obvious decline of CD4+ in T lymphocytes was observed in the TCE-administer group. No significant concentration differences in IFN-gamma and IL-4 were found between TCE-treated and control rats. Gadd45a and Mel were significantly up regulated in skin tissue 24 h after TCE exposure. The expression regulation of immune response factors was as active as proteins associated with lipid metabolism and synthesis process in these skin samples of SD rats exposed to TCE. CONCLUSION: T-helper type 1 cells mediate immune response can not be elicited in TCE-treated SD rats, but certain immune disorder can be induced.