Single-cell transcriptomics reveals an angiogenic cell population for therapeutic angiogenesis in adipose tissue

Background

Therapeutic angiogenesis mediated by stem/progenitor cells is an attractive therapeutic option against cardiovascular disease (CVD). Adipose tissue (AT) can be safely obtained even in CVD patients with anti-platelet medications, and it is a readily available source of culture-expanded adipose-derived stem cells (ADSCs) for transplantation. Single-cell transcriptome enables us to screen all the surface markers at once, while conventional strategies have been limited for the number of target markers. Furthermore, gene profiling at single-cell resolution can be used for the quantification of each marker by how many favorable cells can be purified without mixing of detrimental cells.

Purpose

We aimed to identify and characterize a cell population with in vivo angiogenic potential by single-cell RNA sequencing (scRNA-seq) analysis and xenograft experiments.

Methods

We revisited scRNA-seq datasets of single cell fraction from AT, bone-marrow (BM), and umbilical-cord blood (UCB, n=6/organ) to find cell populations with pro-angiogenic potential. Next, we collected AT from CVD patients (n=23) and used multicolor flow cytometry to quantify and sort the specific populations. PBS, the specific marker-negative and unsorted ADSCs were used as controls. Xenograft models of PKH26 pre-labeled human ADSC transplantation in limb ischemia were used to evaluate the lectin capillary density, PKH+ engrafted ADSCs, and blood flow recovery.

Results

Clustering divided CD45–CD31–CD34+ progenitor fraction into 3 clusters. We identified pro-/anti-angiogenic clusters based on the expressions of well-known pro-/anti-angiogenic factors. All genes encoding cell-surface proteins were compared in this functional clustering, resulted in 17 markers screened (Fig. 1A, B). Taken together with enrichment analysis, CD271+ cells showed predominant and pro-angiogenic gene profile from the other top candidates including CD36 and CD54 (Fig. 1C, D). Next, we evaluated the number and gene profile of CD271+ cells in well-known stem cell sources including BM and UCB. Surprisingly, the number of CD271 expressing cells were significantly lower and did not show angiogenic gene profile in BM and UCB (Fig. 2A). In analysis of AT from 23 CVD patients, CD271+ cells were significantly decreased by donor insulin resistance (Fig. 2B). Cell therapy using CD271+ ADSCs demonstrated in vivo angiogenic capacity compared to those of CD271– ADSCs and PBS in limb ischemia model. Furthermore, CD271+ ADSC transplantation showed enhanced efficacy compared to unsorted ADSCs from the same donors (Fig. 2C–E).

Conclusion

In this study, we identified CD271+ cell population in AT as an angiogenic cell population through scRNA-seq analysis and cell therapy experiments. AT obtained from donors without insulin resistance would be the most suitable for CD271+ ADSC isolation. CD271+ ADSC transplantation with a promising angiogenic capacity could contribute better cell-based therapy tackling CVD.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Japan Society for the Promotion of Science (JSPS) KAKENHI (Tokyo, Japan)

Long-term Outcome 10 Years After Free Gastroepiploic Artery Graft for Coronary Artery Bypass Surgery

BACKGROUND

The long-term benefits of "free" gastroepiploic artery (GEA) grafts remain unclear. The aim of this study is to investigate the long-term patency and clinical results of en bloc free GEA grafts.

METHODS

Of the 1478 patients undergoing coronary artery bypass graft surgery at our institution between January 1997 and December 2009, 137 patients underwent en bloc free GEA grafting. Graft patency, late survival, and freedom from major adverse cardiovascular events were examined. Propensity score matching was used to compare the patency of free GEA grafts with the saphenous vein grafts, and 134 matched pairs were generated.

RESULTS

The early patency rate of free GEA grafts was 98.6%. The long-term patency rates of the free GEA grafts was 96.5% at 5 years, 95% at 10 years, and 86.6% at 15 years. In the 134 matched pairs, the long-term patency rates of free GEA grafts anastomosed to the right coronary artery were significantly higher than those of saphenous vein grafts to the right coronary artery (97% vs 91.8% at 5 years; 95.3% vs 79.6% at 10 years; 85.9% vs 61.7% at 15 years; P < .001). Survival was 94% at 5 years, 86.6% at 10 years, and 66.8% at 15 years; and freedom from major adverse cardiovascular events was 93.2% at 5 years, 91.3% at 10 years, and 73.1% at 15 years.

CONCLUSIONS

En bloc free GEA grafts had favorable long-term performance and can be considered as an effective option for patients who need to receive as many arterial grafts as possible.

Hypothermic preservation of rat hearts using antifreeze glycoprotein

Antifreeze proteins are an effective additive for low-temperature preservation of solid organs. Here, we compared static hypothermic preservation with and without antifreeze glycoprotein (AFGP), followed by nonfreezing cryopreservation of rat hearts. The heart was surgically extracted and immersed in one of the cardioplegia solutions after cardiac arrest. Control rat hearts (n=6) were immersed in University of Wisconsin (UW) solution whereas AFGP-treated hearts (AFGP group) (n=6) were immersed in UW solution containing 500 ?g/ml AFGP. After static hypothermic preservation, a Langendorff apparatus was used to reperfuse the coronary arteries with oxygenated Krebs-Henseleit solution. After 30, 60, 90, and 120 min, the heart rate (HR), coronary flow (CF), cardiac contractile force (max dP/dt), and cardiac diastolic force (min dP/dt) were measured. Tissue water content (TWC) and tissue adenosine triphosphate (ATP) levels in the reperfused preserved hearts were also assessed. All the parameters were compared between the control and AFGP groups. Compared with the control group, the AFGP group had significantly (p<0.05) higher values of the following parameters: HR at 60, 90, and 120 min; CF at all four time points; max dP/dt at 90 min; min dP/dt at 90 and 120 min; and tissue ATP levels at 120 min. TWC did not differ significantly between the groups. The higher HR, CF, max dP/dt, min dP/dt, and tissue ATP levels in the AFGP compared with those in control hearts suggested that AFGP conferred superior hemodynamic and metabolic functions. Thus, AFGP might be a useful additive for the static/nonfreezing hypothermic preservation of hearts.

A modified technique for supra-annular implantation of prosthetic tricuspid valve

In conventional tricuspid valve replacement, there is a risk of valve detachment because stitches are placed on relatively fragile tissues. In the supra-annular implantation technique, stitches are placed lateral to the triangle of Koch and the coronary sinus instead of the anterior and septal leaflets as in conventional tricuspid valve replacement. This procedure relieves stress at the antero-septal commissural area, as well as avoids injury to the conduction system. However, there are a few drawbacks: (1) the valve sits obliquely at the annular surface, (2) the suture line becomes extremely long, and (3) the venous return to the coronary sinus may be impeded. We modified the suture line, which travels lateral to the triangle of Koch and medial to the coronary sinus, to solve these problems. We herein report the technique and results of four cases.

Routine presternotomy extracorporeal circulation for redo surgery

To reduce the risk of adverse events, presternotomy extracorporeal circulation (ECC) is routinely performed at our institution for patients who require resternotomy. We report our 10-year experience of performing presternotomy ECC for cardiac reoperation and the clinical results. Fifty-seven consecutive cardiac reoperations involving resternotomy were performed between January 2006 and December 2015. ECC was established prior to median sternotomy in all patients. Two patients sustained injury to the right ventricle during sternotomy. Eleven patients sustained injury to the mediastinal structures during dissection (right atrium in 3; superior vena cava in 2; inferior vena cava in 3; left internal thoracic artery in 1; and saphenous vein graft in 2 patients). Longer ECC time and greater transfusion volume were necessary. Two patients (3.5%) died within 30 days of operation. Perioperative morbidity included reexploration for bleeding in 4 (7.0%), stroke in 1 (1.8%), acute renal failure that required hemodialysis in 5 (8.8%), sepsis in 5 patients (8.8%), prolonged ventilation in 9 (15.8%) and tracheostomy in 5 (8.8%). Routine establishment of presternotomy ECC reduces the risk of injury to the mediastinal structures during reentry and facilitates easier repair in the event of structural injury during reentry or dissection. However, longer ECC time and significantly greater transfusion volume requires attention.

P3495Long-term engraftment of human CD271-positive adipose-derived stem cells with pericytic and less-aged gene profile in a mouse model of hindlimb ischemia

Background

Therapeutic angiogenesis using adipose-derived stem cells (ADSCs) is an attractive strategy for ischemic cardiovascular diseases. We previously reported that human CD271+ population of adipose-derived stem cells (ADSCs) promoted neovascularization with enhanced engraftment in a mouse model of hindlimb ischemia. However, whether and how CD271+ ADSCs promote the long-term engraftment is still uncertain.

Purpose

We aimed to examine whether the angiogenic effect and cell engraftment capacity of CD271+ ADSCs would be sustained in long-term period. Then, comparative gene profiling between CD271+ and CD271- ADSCs were analyzed. Finally, cell proliferation and endothelial differentiation assays were conducted.

Methods

ADSCs were isolated from subcutaneous adipose tissue of 5 patients received cardiovascular surgery. CD271+ and CD271- ADSCs were sorted from CD45-CD31-CD34+ ADSCs fraction by FACS sorting (Fig. A). Cultured CD271+ and CD271- ADSCs at passage 6 were labeled by PKH26 cell linker dye and used for xenograft experiments. Briefly, athymic nude mice were subjected to hindlimb ischemia and one million of human ADSCs were injected into the ischemic muscles. In control group, PBS was solely injected. At 2 and 5 weeks, neovascularization was evaluated by immunohistochemistry (capillary density using lectin perfusion). Cell engraftment was assessed by counting PKH26-positive cells. Furthermore, we compared gene profiling between CD271+ and CD271- ADSCs by microarray. Proliferative capacity was evaluated by colony-forming unit (CFU) assay with Giemsa staining. In endothelial differentiation assay, CD271+ and CD271- ADSCs were cultured in differentiation induction medium containing vascular endothelial growth factor for 2 weeks and stained with anti-human CD31 antibody.

Results

Cell therapy using CD271+ ADSCs demonstrated approximately 3-fold more enhanced neovascularization than those using CD271- ADSCs or PBS in histological analysis of capillary density at 2 weeks from cell therapy (Fig. B and C). At 5 weeks, mice treated with CD271+ ADSCs were significantly rescued from limb ischemia and this was accompanied by sustained engraftment of ADSCs (Fig. D). In microarray analysis, the differentially expressed 2167 genes were extracted to classify CD271+ and CD271- ADSCs. Pathway analysis demonstrated CD271 expression on ADSCs was associated with the pathways related to stemness and cell differentiation. Indeed, we found that genes related to cell proliferation (PI3K, Cyclin D, and Cyclin D2) were up-regulated in CD271+ ADSCs. Additionally, we found the pericytic marker nestin which was significantly up-regulated in CD271+ ADSCs. Consistent with these findings, CD271+ ADSCs were more proliferative and capable for endothelial differentiation while CD271- ADSCs were not.

FACS and cell therapy experiments

Conclusion

These results suggest that CD271+ ADSCs possess long-term engraftment and angiogenic capacity due to their less-aged and more pericytic gene profile.

Acknowledgement/Funding

Japan Society for the Promotion of Science (JSPS) KAKENHI (Tokyo, Japan) Grant Number JP16H06828

Implementation of bundled interventions greatly decreases deep sternal wound infection following cardiovascular surgery

OBJECTIVE

Surgical site infection (SSI), particularly deep sternal wound infection (DSWI), is a serious complication after cardiovascular surgery because of its high mortality rate. We evaluated the effectiveness of an SSI bundle to reduce DSWI and identify the risk factors for DSWI.

METHODS

During the period January 2004 to February 2012, 1374 consecutive patients undergoing cardiovascular surgery via sternotomy were included. The cohort was separated into periods from January 2004 through February 2007 (period I, 682 patients) and March 2007 through February 2012 (period II, 692 patients). During period II, all preventive measures for DSWI were completed as an SSI bundle. We compared the DSWI rate between the 2 periods. Univariate and multivariate analyses were performed for the entire period to identify the risk factors for DSWI.

RESULTS

DSWI occurred in 13 patients (1.9%) during period I and in 1 patient (0.14%) during period II. The DSWI rate during period II was significantly decreased by 93%, compared with period I (P=.001). Independent risk factors for DSWI included obesity (odds ratio [OR], 3.4; 95% confidence interval [CI], 1.00-11.75; P=.049), the use of 4 sternal wires (OR, 8.2; 95% CI, 1.39-48.14; P=.020), long operative time (OR, 4.4; 95% CI, 1.20-16.23; P=.026), and postoperative renal failure (OR, 9.0; 95% CI, 2.44-33.30; P=.001).

CONCLUSIONS

Complete implementation of simple multidisciplinary prevention measures as a bundle can greatly decrease the incidence of DSWI.

Behçet's disease accompanied by myelodysplastic syndrome with trisomy 8: two case reports and a review of 15 Japanese cases

Abstract We describe two cases of Behçet's disease associated with myelodysplastic syndrome (MDS) with trisomy 8. Both cases developed ulceration in the cecum as a gastrointestinal complication of Behçet's disease, after a diagnosis of MDS. We summarized recent case reports of Behçet's disease associated with myelodysplastic syndrome, and studied the clinical manifestations. Most cases showed trisomy 8 as a chromosomal abnormality. Gastrointestinal involvement without eye lesions seems to be characteristic of Behçet's disease associated with MDS.

Retrograde cardioplegia revisited: open technique for long aortic cross clamping

BACKGROUND

The efficacy of retrograde cardioplegia for myocardial protection is still controversial. In our institution, we exclusively use intermittent administration of tepid, undiluted blood supplemented with potassium and magnesium for the cases with aortic insufficiency, requiring aortotomy, or undergoing mitral valve repair. In using this retrograde technique, we make a point of cannulating a retrograde perfusion catheter under direct vision following right atriotomy. The purpose of this retrospective study is to evaluate the clinical outcome of using this technique.

METHODS

This study comprises 49 patients who underwent elective valve surgery using direct-vision retrograde cardioplegia exclusively, requiring more than 3h aortic cross-clamping. Their clinical outcome was reviewed retrospectively.

RESULTS

There was no hospital mortality in this study. No patient was noted to have evidence of mediastinitis, myocardial infarction, or cerebral complications in the postoperative period. The case requiring the longest aortic cross-clamping time (380 min) survived the operation without the use of intra-aortic balloon pumping or percutaneous cardiopulmonary support, and the postoperative course was uneventful.

CONCLUSIONS

Our result suggests that direct-vision retrograde cardioplegia is a safe and effective method of cardioplegia delivery, and provides a longer period of myocardial protection than previously thought.

Persistent spontaneous pneumothorax for four years: a case report

Pneumothorax, defined as the presence of air in the pleural space, is usually classified as spontaneous or traumatic; it is unusual for pneumothorax to be categorized as being acute or chronic. Even if conservative treatment is chosen, the pneumothorax is cured when air in the pleural space dissolves into the venous blood. A 50-years-old Japanese man with no prior medical history was referred to our department with a right pneumothorax and two rightsided pulmonary nodules on chest X-ray and CT. The chest radiographs of past mass screening which was taken four years ago showed right pneumothorax and right-sided pulmonary nodules. From then, all chest radiograph and chest computed tomography showed right pneumothorax and pulmonary nodules. But he underwent no medical interventions. We designed to perform an operation for a treatment of right pneumothorax and the diagnosis of pulmonary tumors. We underwent right upper lobectomy and pleural decortication under video assisted thoracic surgery. We obtained pathological diagnosis of inflammatory pseudotumor and surrounding atelectasis. He was cured from pneumothorax and pulmonary tumors. A unique case of spontaneous pneumothorax presenting with a pleural air space that was confirmed by chest radiographs and computed tomography examinations over a 4-year period is reported.

Selective blockade of apoptosis by in vivo electroporation-mediated gene transfer combined with portal infusion of plasmid DNA attenuates liver cirrhosis

AIM

The purpose of the present study was to determine whether in vivo electroporation could achieve selective blockade of apoptosis in a rat liver cirrhosis model.

METHODS

A dimethylnitrosamine (DMN)-induced rat liver cirrhosis model was used. In vivo electroporation was performed after portal vein infusion of plasmid DNA. pFas-Fc plasmid DNA was used to block the apoptotic pathway. pUC/HGF and pCAGGS/EGFP were used as positive and negative controls, respectively. Liver collagen content was evaluated by hydroxyproline assay two weeks after gene transfer. Terminal deoxynucleotidyltransferase dUTP nick end-labeling was simultaneously performed in the liver to evaluate suppression of apoptosis. Survival analysis was performed using 10 rats that received the sFas gene, 10 that received the HGF gene, and 13 that received the GFP gene.

RESULTS

The apoptotic cell index in the DMN-injected liver was significantly lower in rats that received the sFas gene compared with the negative control. The collagen content of the DMN-injected liver was also lower in rats that received the sFas gene compared with the negative control. There was no significant difference in the apoptotic cell index and collagen content of rats that received the sFas and HGF genes. Ten weeks after the initiation of DMN treatment, the survival rates with the sFas, HGF, and GFP genes were 56%, 100%, and 0, respectively.

CONCLUSION

Selective blockade of apoptosis by in vivo electroporation-mediated gene transfer improved the apoptotic cell index, hydroxyproline content, and survival rate. Soluble Fas gene therapy using in vivo electroporation can be a safe and efficient therapy for liver cirrhosis in rats.

[Reconstruction of the left common carotid artery for dissective occlusion detected by intra-operative ultrasonography]

We describe a case of Stanford type A acute aortic dissection. Replacement of the ascending aorta and aortic arch was performed using an "arch 1st technique". Following the completion of replacement, hypotension of the left superficial temporal artery pressure was detected. Ultrasonography revealed dissection of the left common carotid artery (LCCA) and compressive occlusion of the true lumen. Reconstruction of the LCCA was performed in the neck. The patient did well after the operation without any neurological abnormalities.

[Severe coronary artery spasm immediately after aortic valve replacement]

We report a case of 72-year-old man with severe manifestations of coronary artery spasm immediately after aortic valve replacement (AVR), which was associated with hemodynamic and arrhythmic instability. The AVR was performed under mild hypothermic cardiopulmonary bypass (34 degrees C), and retrograde blood cardioplegia was intermittently delivered at the same temperature. Immediately after the operation, the patient suddenly developed severe bradycardia and hypotension, and repeated ventricular fibrillation. Percutaneous cardiopulmonary support system (PCPS) and intra-aortic balloon pumping (IABP) were required for this circulatory collapse. Echocardiography revealed left ventricular segmental dysfunction, and coronary artery bypass grafting (CABG) to the right coronary artery and the left ascending artery was performed [during CABG, coronary spasm was strongly suspected by repetitive ST elevation and depression on electrocardiogram (ECG) monitor]. Eventually, the spasm subsided with the intravenous infusion of nitrates, nicorandil, and diltiazem. The remaining postoperative course was uneventful and the patient was discharged on the 24th postoperative day in good clinical condition.

The intracellular accumulation of phagocytic and epithelial cells and the inhibitory effect on Chlamydophila (Chlamydia) pneumoniae of telithromycin and comparator antimicrobials

The intracellular accumulation of telithromycin was measured and compared with ciprofloxacin, clarithromycin, minocycline and erythromycin. The activities of telithromycin, clarithromycin and minocycline against Chlamydophila (Chlamydia) pneumoniae were compared in an intracellular killing assay. Maximal telithromycin accumulation (mean intracellular/extracellular concentration ratio) ranged from 6.7 (A549 lung epithelial cells) to 11.8 (THP-1 monocytic cells). This ratio was similar to that of clarithromycin, but less than for minocycline. Minimum inhibitory and minimum lethal telithromycin concentrations against six clinical strains of C. pneumoniae were <0.015-0.03 mg/L and 0.03-0.06 mg/L, respectively, which were lower than those found for minocycline. These results show that telithromycin accumulates rapidly into epithelial cells, similar to previously reported results for phagocytic cells. Intracellular accumulation of telithromycin was lower than that observed for minocycline, but telithromycin demonstrated substantially more potent antichlamydial activity.

Spontaneous Restoration of Patency in the Free Gastroepiploic Artery Graft: The Living Transplanted Vascular System for Coronary Revascularization

We report an incidence of coronary revascularization with the gastroepiploic artery in which angiography demonstrated patency at 1 month, severe narrowing at 1 year, and restoration of patency associated with progression of proximal coronary disease at 8 years. This report documents the reversibility of the free gastroepiploic artery.

[Anaphylactic shock related to aprotinin induced by anti-aprotinin immunoglobulin G antibody alone; report of a case]

Anaphylactic shock related to aprotinin has been reported to be induced exclusively in the presence of IgE antibody. And the possibility of anaphylactic shock induced by anti-aprotinin IgG antibody alone was controversial. In this paper, we describe the first case of anaphylactic shock induced by aprotinin-specific IgG antibody alone. A 55-year-old man underwent surgical repair of the descending aorta with the use of aprotinin at 2 months after first aprotinin usage. Immediately after initiation of cardiopulmonary bypass with the continuous infusion of aprotinin, clinical symptoms of anaphylactic reaction were found. Postoperative drug lymphocyte stimulation test for aprotinin and aprotinin-specific IgE antibody were negative, but aprotinin-specific IgG antibody was 163 mg/l and positive.

[New method for preparing proximal anastomotic system]

Heartstring is a useful device. However, the device failure at the time of loading the seal into the delivery device is a troublesome issue. To avoid this problem, we invent a new method using 2 tourniquets made of 5 mm-wide woven Teflon tapes and plastic tubes. Using our method, the loading procedure became easier and more reliable.

p21CDKN1A allows the repair of replication-mediated DNA double-strand breaks induced by topoisomerase I and is inactivated by the checkpoint kinase inhibitor 7-hydroxystaurosporine

This study provides evidence for the importance of p21(CDKN1A) for the repair of replication-mediated DNA double-strand breaks (DSBs) induced by topoisomerase I. We report that defects of p21(CDKN1A) and p53 enhance camptothecin-induced histone H2AX phosphorylation (gammaH2AX), a marker for DNA DSBs. In human colon carcinoma HCT116 cells with wild-type (wt) p53, gammaH2AX reverses after camptothecin removal. By contrast, gammaH2AX increases after camptothecin removal in HCT116 cells deficient for p53 (p53-/-) or p21(CDKN1A) (p21-/-) as the cells reach the late-S and G2 phases. Since p21-/- cells exhibit similar S-phase arrest as wt cells in response to camptothecin and aphidicolin does not abrogate the enhanced gammaH2AX formation in p21-/- cells, we conclude that enhanced gammaH2AX formation in p21-/- cells is not due to re-replication. The cell cycle checkpoint abrogator and Chk1/Chk2 inhibitor 7-hydroxystaurosporine (UCN-01) also increases camptothecin-induced gammaH2AX formation and inhibits camptothecin-induced p21(CDKN1A) upregulation in HCT116 wt cells. TUNEL (terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labeling) assays demonstrate that gammaH2AX formation in late S and G2 cells following CPT treatment corresponds to DNA breaks. However, these breaks are not related to apoptotic DNA fragmentation. We propose that p21(CDKN1A) prevents the collapse of replication forks damaged by stabilized topoisomerase I cleavage complexes.

Evaluation of a fully automated system (RAISUS) for rapid identification and antimicrobial susceptibility testing of Staphylococci

RAISUS is a system for rapid bacterial identification and antimicrobial susceptibility testing. RAISUS and VITEK showed 97.8% and 75.9% agreement in identification of 45 Staphylococcus aureus strains and 58 coagulase-negative staphylococci (CoNS), respectively, and RAISUS and CLSI (formerly NCCLS) methods showed 87.2% and 87.9% agreement in the MICs for S. aureus and CoNS, respectively. RAISUS provided these data within 3.75 h, suggesting its utility for clinical bacteriological laboratories.

[Arch first technique using handmade branched graft]

We created a method using handmade branched graft to do the aortic arch surgery easier and safer. We made the branched graft using 12 and 8 mm vascular graft. A 77-year-old man with Stanford type A aortic dissection was operated with this method under deep hypothermia. After aortic root manipulation, perfusion of the aortic arch was stopped and selective cerebral perfusion was established. Left subclavian artery (LSCA) was anastomosed to one of the branches. The perfusion of the LSCA was re-started via one of its branches. Respectively, left common carotid artery and brachiocephalic artery reconstruction and reperfusion were performed in a same fashion. After distal anastomosis, anastomosis between the branched graft and main graft was performed consecutively. Postoperative course was uneventful and there was no complication. The treatment of our branched graft was easier than that of ready-made 4-branched graft. We could perform the operation under clear view for its movability with minimal cerebral ischemic time.

Comparison of NSP4 protein between group A and B human rotaviruses: detection of novel diarrhea-causing sequences in group B NSP4

The human group B rotavirus is a causative agent of severe adult diarrhea. In this study, we analyzed the NSP4 structure of a group B rotavirus strain, CAL-1, and determined whether enterotoxin activity was present in CAL-1 NSP4. CAL-1 NSP4 was comprised of 219 amino acids which was longer than group A and C rotavirus NSP4, and the primary structures of their sequences differed considerably. However, CAL-1 NSP4 had an enterotoxin-like sequence (residues 106-127) that was only 27% identical to the enterotoxin region of NSP4 of KUN (a group A rotavirus strain) at residues 114-135. Interestingly, both of the synthetic peptides, one (residues 99-128) containing the enterotoxin-like sequence and the other (residues 191-219) containing 29 C-terminal amino acids of CAL-1 NSP4, induced diarrhea in 5.5-day-old mice, but not in 17.5-day-old mice, when administered parenterally. Thus, rotavirus "enterotoxin" sequences could be considerably divergent.

Average P/F ratio during donor management for finding out the potential donor of lung procurement

We investigated the potential donors from cases without lung procurement in spite of considering procurement as the donor. We reviewed 207 cases considered for lung procurement. Donors were divided into 2 groups according to whether or not their lungs were harvested: 50 did and 157 did not. We investigated their age, gender, donor management periods, blood pressure, heart rate, P/F ratio, PCO2, HCO3, positive end-expiratory pressure (PEEP), respiratory rate, abnormal findings in the chest X-ray, blood chemistries, sputum culture, and intravenous administration of steroid. Univariable or multivariable logistic regression analysis was used to predict lung harvesting by various factors. Univariable logistic regression analysis revealed maximum heart rate (HR) and respiratory rate (RR), maximum, minimum, and average P/F ratio, and abnormal findings in the chest X-ray, to be predictors to perform transplant. The maximum HR and RR of the non-harvest group are higher than those of the harvest group. Multivariable logistic regression analysis revealed average P/F ratio only to be a predictor to transplant. We divided the non-harvest group into 2 groups according to whether or not their P/F ratio was >300: 55 did (P/F 300 group) and 102 did not (P/F 299 group). Between P/F 299 group and the harvest group, univariable logistic regression analysis revealed maximum HR, maximum and minimum RR, maximum PEEP, maximum, minimum, and average P/F ratio, and abnormal findings in the chest X-ray to be predictors to transplant. Maximum HR, PEEP, and maximum and minimum RR of the P/F 299 group are higher than those of the harvest group. Maximum, minimum, and average P/F ratio of the P/F 299 group are lower than those of the harvest group. The average PCO2 of P/F 299 group is higher than that of the harvest group. The rate of abnormal findings in the chest X-ray of the P/F 299 group is higher than that of the harvest group. Multivariable logistic regression analysis revealed average P/F ratio only to be a predictor to transplant. There were no predictors between the P/F 300 group and the harvest group in both univariable and multivariable logistic regression analyses. Furthermore, there were no different factors between the P/F 300 group and the harvest group. Our study showed that 35.5% of the non-harvest group had a P/F ratio of >300 and had no difference compared with the harvest group. Our data suggest that potential donors existed in the non-harvest group and increased the number of lung procurement to 27.3% from 13.0% of all donors.

[Clinical experience with aortic connector system]

From April to December 2002, 40 patients underwent coronary artery bypass grafting (CABG) using the St. Jude Medical (Minneapolis) Symmetry bypass system (aortic connector system: ACS). 59 proximal anastomoses (51 saphenous vein grafts, 8 radial artery grafts) were performed with the ACS. One saphenous vein graft occluded during operation. Postoperative evaluation of the anastomotic patency was carried out by angiography in 45 grafts. Five of the saphenous vein grafts were occluded (5/38). One patient who was shock state before operation presented with postoperative unconsciousness. Another patient died at 8th postoperative day caused by ventricular fibrillation. We conclude that the ACS produces a simple, quick way of performing the proximal anastomosis without the need for clamping the aorta, allows reducing risk of embolization by aortic manipulation. However, it is necessary to discuss sufficiently using the ACS, because the graft patency with the ACS is lower than with standard suturing technique.

Pathophysiological Significance of T-type Ca2+ Channels: Expression of T-type Ca2+ Channels in Fetal and Diseased Heart

Re-expression of fetal genes has been considered to underlie ionic remodeling in diseased heart. T-type Ca(2+) channels have been reported to be functionally expressed in embryonic hearts. In this review, we summarize developmental changes of T-type Ca(2+) channels in mouse ventricles from 9.5 days postcoitum (dpc) to adulthood, using patch clamp and quantitative PCR. In addition, we introduced T-type Ca(2+) channel expression in hypertrophied ventricles caused by myocardial infarction (MI) and aortic banding (AOB). Substantial T-type Ca(2+) channel current was recorded at both 9.5 and 18 dpc. The currents were inhibited by Ni(2+) at low concentrations. The current was not detectable in the adult stage. Ca(v)3.2 (alpha(1H)) mRNA is expressed dominantly at both 9.5 and 18 dpc. Ca(v)3.1 (alpha(1G)) increases from 9.5 to 18 dpc, but remains at low level compared with Ca(v)3.2. In contrast, Ca(v)3.1 is greater than Ca(v)3.2 at the adult stage. In MI, Ca(v)3.1 mRNA correlates negatively with brain natriuretic peptide (BNP) mRNA, whereas Ca(v)3.2 mRNA correlates positively with BNP mRNA. In AOB, these correlations are weak. We also analyzed the neuron-restrictive silencer factor (NRSF) in these hearts because it is the suppressor of transcription of the fetal cardiac gene program. The negative correlation between NRSF and BNP was stronger in MI than in AOB. Our findings show that Ca(v)3.2 underlies the functional T-type Ca(2+) channel in embryonic heart and suggest that NRSF may regulate Ca(v)3.2 expression in diseased hearts.

Subtype Switching of L-Type Ca 2+ Channel From Cav1.3 to Cav1.2 in Embryonic Murine Ventricle

BACKGROUND

Embryonic hearts exhibit spontaneous electrical activity, which depends on Ca2+ influx through L-type Ca2+ channels. In this study the expression of the L-type Ca2+ channel alpha1 subunit gene in the developing mouse heart was investigated.

METHODS AND RESULTS

Mouse cardiac ventricles 9.5 days post coitum (dpc), 18 dpc and adult were used. At 9.5 dpc the level of Cav1.3 mRNA was higher than that of Cav1.2 mRNA. With development, Cav1.2 mRNA increased and Cav1.3 mRNA decreased. Analysis of Cav1.3 splicing variants showed that Cav1.3(1b) mRNA was expressed at a higher density than Cav1.3(1a) mRNA. Cav1.3 protein was detected only at 9.5 dpc, whereas Cav1.2 protein was expressed from 9.5 dpc and its expression increased with development. L-type Ca2+ currents were prominent at 9.5 dpc. The Ca2+ current amplitude at 9.5 dpc was comparable to that at 18 dpc, and was larger in adults than at the embryonic stage. L-type Ca2+ current at 9.5 dpc was activated and/or inactivated at more negative membrane potentials than at 18 dpc or adult. L-type Ca2+ channels at 9.5 dpc were less sensitive to inhibition by nisoldipine than at adult.

CONCLUSIONS

The Cav1.3 channel is functionally expressed in early embryonic mouse ventricular myocytes and potentially underlies ventricular automaticity.

[Surgery for acute aortic dissection concomitant with preceding axillofemoral bypass to prevent malperfusion of visceral organs and limb ischemia]

A 52-year-old man was admitted with sudden onset of epigastralgia. Abdominal X-ray showed dilated intestine and computed tomography (CT) revealed extended type A aortic dissection. Marked abdominal distention and weak pulse of right femoral artery were recognized so malperfusion of visceral organs due to narrowing true lumen compressed by thrombosed false lumen was suggested. In the operation, right axillo-right femoral bypass was established preceding to median sternotomy. This graft was used as an arterial perfusion site of cardiopulmonary bypass, and replacement of the ascending aorta was performed under hypothermic circulatory arrest and retrograde cerebral perfusion. Sign of malperfusion of visceral organs was showed for several days after the operation but it disappeared without further intervention. Axillofemoral inflow of cardiopulmonary bypass may be effective procedure in these cases.

Cav3.2 subunit underlies the functional T-type Ca2+ channel in murine hearts during the embryonic period

T-type Ca2+ channels are implicated in cardiac automaticity, cell growth, and cardiovascular remodeling. Two voltage-gated Ca2+ subtypes (Ca(v)3.1 and Ca(v)3.2) have been cloned for the pore-forming alpha(1)-subunit of the T-type Ca2+ channel in cardiac muscle, but their differential roles remain to be clarified. The aim of this study was to elucidate the relative contribution of the two subtypes in the normal development of mouse hearts. A whole cell patch clamp was used to record ionic currents from ventricular myocytes isolated from mice of early (E9.5) and late embryonic days (E18) and from adult 10-wk-old mice. Large T-type Ca2+ current (I(Ca,T)) was observed at both E9.5 and E18, displaying similar voltage-dependence and kinetics of activation and inactivation. The current was inhibited by Ni2+ at relatively low concentrations (IC(50) 26-31 microM). I(Ca,T) was undetectable in adult myocytes. Quantitative PCR analysis revealed that Ca(v)3.2 mRNA is the predominant subtype encoding T-type Ca2+ channels at both E9.5 and E18. Ca(v)3.1 mRNA increased from E9.5 to E18, but remained low compared with Ca(v)3.2 mRNA during the whole embryonic period. In the adulthood, in contrast, Ca(v)3.1 mRNA is greater than Ca(v)3.2 mRNA. These results indicate that Ca(v)3.2 underlies the functional T-type Ca2+ channels in the embryonic murine heart, and there is a subtype switching of transcripts from Ca(v)3.2 to Ca(v)3.1 in the perinatal period.

Effects of vitamin supplementation on microcirculatory disturbance in hemodialysis patients without peripheral arterial disease

AIMS

Dysfunctional endothelium caused by oxidative stress is thought to play a role in pathogenesis of a variety of conditions including atherosclerosis. We investigated whether a microcirculatory disturbance in hemodialysis (HD) patients was associated with increased oxidative stress and endothelial injury.

PATIENTS AND METHODS

Transcutaneous oxygen tension (TcPO2) on the dorsum of the foot at rest was measured as a marker of microcirculation in 33 patients undergoing HD without clinical manifestations of peripheral arterial disease and 20 healthy controls. Furthermore, in order to examine whether TcPO2 was affected by antioxidants, oral supplementation with a combination of vitamin C (200 mg daily) and vitamin E (600 mg daily) was administered for 6 months to 8 patients with microcirculatory disturbance (TcPO2 values of 50 mmHg or less). Serum biochemical parameters including vitamins were also measured.

RESULTS

Mean TcPO2 value was significantly lower in HD patients than in control subjects (47.9 +/- 13.5 mmHg versus 62.4 +/- 11.9 mmHg, p < 0.001). After vitamin supplementation, TcPO2 values remarkably increased (40.6 +/- 10.0 mmHg versus 57.4 +/- 6.5 mmHg, p < 0.005). Serum vitamin C and vitamin E levels increased significantly as well, while serum levels of thrombomodulin, a marker of endothelial injury, and thiobarbituric acid reactants, a marker of lipid peroxidation, were significantly decreased in comparison with those before supplementation.

CONCLUSIONS

Our results suggest that the microcirculatory disturbance in HD patients seems to be associated with endothelial damage caused by oxidative stress. Combined supplementation with vitamin C and vitamin E may be of clinical benefit in improving the cutaneous microcirculation by reducing oxidative stress.

Multiple minimally invasive direct CABG for the complete revascularization: the figure L approach

BACKGROUND

Coronary artery bypass grafting on the beating heart via median sternotomy causes significant hemodynamic compromise during displacement of the heart, especially in patients with low ejection fraction or those who have potential catastrophic sternal reentry injuries. We have developed an innovative minimally invasive surgical approach (figure L Approach) for the treatment of multi-vessel coronary artery disease; especially in cases with huge hearts (> CTR 50 %) including tracheostomy requiring COLD, and redo cases. The objective of this study was to assess the efficacy and safety of this alternative surgical incision.

METHODS

From January 1998 to March 2001, 22 patients underwent complete revascularization using this figure L Approach. Left submammary anterior thoracotomy incisions are made with the medial part of the incision vertically extending downward to the upper abdomen. The costal margin was divided. The pleural and peritoneal spaces were then entered. A chest retractor was placed to elevate the chest wall, exposing the heart and stomach. Two to four arterial grafts including LIT A, RGEA, RA and IEA were harvested. Revascularization of the LAD, LCX and distal RCA were performed in 22 patients without cardiopulmonary bypass on complex performed arterial grafts using this approach. In four patients, triple and quadruple vessel grafting was performed.

RESULTS

No early deaths or postoperative complications occurred. The mean coronary clamp time was 12.5 +/- 5.1 minutes for the LAD, 10.8 +/- 1.8 minutes for diagonal branch, 14.1 +/- 2.9 minutes for the LCX and 16.0 +/- 5.1 minutes RCA time. There were no late deaths or angina during the mean follow-up of 37.3 +/- 9.0 months. Postoperative coronary angiography demonstrated widely patent grafts in all but one patient. Hemodynamics did not change significantly during the distal anastomoses. No wound-healing problems were experienced.

CONCLUSIONS

Multiple MIDCABG using the figure L Approach represents a novel way of approaching both the LAD, CX and distal RCA in patients with multi-vessel disease, especially in those with low ejection fraction, huge heart (> CTR 50 %), or hemodynamically unstable patients, without any hemodynamic deterioration or sternal related complication.

An HLA-B27-positive patient diagnosed with ulcerative colitis 15 years after the onset of arthropathy

Abstract A 28-year-old woman had persistent pain of both hip joints since the age of 13 years. X-ray analysis showed destructive changes in both hip joints and ossification of sacroiliitic joints. The patient had mild diarrhea and slight abdominal pain for 8 years. Blood-stained stool was not noticed. Barium enema showed changes consistent with the diagnosis of ulcerative colitis (UC). Inflammatory bowel syndrome should be considered in patients with persistent coxitis, even in the absence of severe abdominal symptoms.

Ionic mechanisms of acquired QT prolongation and torsades de pointes in rabbits with chronic complete atrioventricular block

BACKGROUND

The ionic basis of acquired QT prolongation and torsade de pointes (TdP) unrelated to drugs is not fully understood.

METHODS AND RESULTS

We created a rabbit model with chronic complete atrioventricular block (AVB) (n=34), which showed prominent QT prolongation (by 120%), high incidence of spontaneous TdP (71%), and cardiac hypertrophy. Patch-clamp experiments were performed in left ventricular myocytes from 9 rabbits (8 with TdP, 1 without TdP) at approximately 21 days of AVB and from 8 sham-operated controls with sinus rhythm. Action potential duration was prolonged in AVB myocytes compared with control (+61% at 0.5 Hz, +21% at 3 Hz). Both rapidly and slowly activating components of the delayed rectifier K(+) current (I(Kr) and I(Ks)) in AVB myocytes were significantly smaller than in control by 50% and 55%, respectively. There was no significant difference in Ca(2+)-independent transient outward current (I(to1)). L-type Ca(2+) current (I(Ca,L)) in control and AVB myocytes was similar in peak amplitude, but the half voltage for activation was shifted to the negative direction (5.9 mV) in AVB myocytes. Voltage dependence of I(Ca,L) inactivation was not different in control and AVB myocytes. The inward rectifier K(+) current (I(K1)) significantly increased in AVB myocytes compared with control.

CONCLUSIONS

In the rabbit, chronic AVB leads to prominent QT prolongation and high incidence of spontaneous TdP. Downregulation of both I(Kr) and I(Ks) in association with altered I(Ca,L) activation kinetics may underlie the arrhythmogenic ventricular remodeling.

Optimal Size of Prostheses for Functioning of the Aortic Prosthetic Valve in Aortic and Mitral Valve Replacement with Annular Enlargement through Manouguian's Technique

There is not yet agreement about the optimal size of the prostheses in aortic and mitral valve replacement with Manouguian's technique. In this technique, the aortic prosthetic valve can be pushed upon the mitral prosthesis which may cause dysfunction of the aortic prosthetic valve. The aim of this study was to clarify the size of the prostheses needed to avoid dysfunction of the aortic prosthetic valve. Three patients underwent aortic and mitral valve replacement through this procedure. Two of them had active aortic and mitral valve endocarditis. Aortomitral continuity involved with abscesses could be approached and completely excised using this technique. All patients survived the operation, but 1 of them suffered aortic mechanical valve dysfunction for the reason stated. Anatomical analysis of the geometrical relation of the 2 prosthetic valves suggests that the mitral annulus should be enlarged less than 25 mm to avoid dysfunction of the aortic prosthetic valve.