Generation of functional human vascular network

BACKGROUND

One of the major obstacles in regenerating thick, complex tissues such as the liver is their need for vascularization, which is essential to maintain cell viability during tissue growth and to induce structural organization. Herein, we have described a method to engineer a functional human vascular network.

METHODS

Enhanced green fluorescence protein-labeled human umbilical vein endothelial cells (GFP-HUVECs) were cocultivated with kusabira orange-labeled human mesenchymal stem cells (KO-hMSCs) inside a collagen/fibronectin matrix. Premature vascular network formation was visualized by fluorescence microscopy imaging. Furthermore, constructs prevascularized in vitro were implanted into a transparency window in immunodeficient mice.

RESULTS

Following several days of cultivation, GFP-HUVECs formed vessel-like structures that were stabilized by pericytes differentiated from KO-hMSCs. After implantation in vivo, the patency of human vascular structures was proved by rhodamine dextran infusion. These functional vascular structures remained for over 2 months.

DISCUSSION

Vascularization is the key challenge to organ generation. We successfully generated human vascular networks inside a matrix. Integration of parenchymal cells using our engineering technique should facilitate future efforts to reconstitute vascularized human organ systems in vitro.

CT evaluations of focal liver reactions following stereotactic body radiotherapy for small hepatocellular carcinoma with cirrhosis: relationship between imaging appearance and baseline liver function

This study aimed to assess the imaging appearances of focal liver reactions following stereotactic body radiotherapy (SBRT) for small hepatocellular carcinoma (HCC) and to examine relationships between imaging appearance and baseline liver function. We retrospectively studied 50 lesions in 47 patients treated with SBRT (30-40 Gy in 5 fractions) for HCC, who were followed up for more than 6 months. After SBRT, all patients underwent regular follow-ups with blood tests and dynamic CT scans. At a median follow-up of 18.1 months (range 6.2-43.7 months), all lesions but one were controlled. 3 density patterns describing focal normal liver reactions around HCC tumours were identified in pre-contrast, arterial and portal-venous phase scans: iso/iso/iso in 4 patients (Type A), low/iso/iso in 8 patients (Type B) and low/iso (or high)/high in 38 patients (Type C). Imaging changes in the normal liver surrounding the treated HCC began at a median of 3 months after SBRT, peaked at a median of 6 months and disappeared 9 months later. Liver function, as assessed by the Child-Pugh classification, was the only factor that differed significantly between reactions to treatment showing "non-enhanced" (Type A and B) and "enhanced" (Type C) appearances in CT. Hence, liver tissue with preserved function is more likely to be well enhanced in the delayed phase of a dynamic contrast-enhanced CT scan. The CT appearances of normal liver seen in reaction to the treatment of an HCC by SBRT were therefore related to background liver function and should not be misread as recurrence of HCC.

[Aortic dissection and annulo-aortic ectasia complicating systemic lupus erythematousus; report of a case]

A 31-year-old man with systemic lupus erythematosus had received long term steroid therapy. He had no compliant, but magnetic resonance imaging showed aortic dissection and annulo-aortic ectasia. Echocardiogram showed severe aortic regurgitation. Therefore aortic root replacement was performed. A histological study of the aortic wall demonstrated myxomatous degeneration in the media. He recovered uneventfully, except for receiving continious hemodia filtration during 4 days after the operation

[Infective endocarditis with the fistula from sinus Valsalva to right atrium and ventricle; report of a case]

A 77-year-old man complained general fatigue and fever. Preoperative echocardiography revealed vegetation of aortic valve, abnormal shunt flow from the sinus of Valsalva was detected in the right atrium and ventricle without perivalvular abscess cavity or aneurysm of the sinus of Valsalva. He diagnosed aortic valve endocarditis with aorto-right atrium and ventricle fistula. He received aortic valve replacement and patch closure at the sinus of Valsalva using the pericardium. Residural aortic-right atrium and ventricle shunt was not detected after the operation, the post operative course was uneventful without congestive heart failure nor signs of infection.

[Large coronary aneurysm after coronary intervention for acute myocardial infarction; report of a case]

A 59-year-old man was admitted to our hospital because of angina pectoris and a large right coronary aneurysm. Two years previously, he underwent percutaneous coronary balloon angioplasty for a stenotic lesion in right coronary artery (RCA) #3. Angiography and computed tomography showed a large right coronary aneurysm. On-pump coronary artery bypass grafting (CABG), ligation of RCA proximal and distal to the aneurysm, resection of the aneurysm was performed successfully. Postoperative course was uneventful with satisfactory angiographic results.

[Perforation due to new myocardial infarction long time; report of a case]

A 65-year-old man was admitted to the hospital because of effort chest pain, 8 years after he received coronary artery bypass grafting [CABG: left internal thoracic artery (LITA) to left anterior descending artery (LAD), saphenous vein graft (SVG) to first diagonal branch (D1) and SVG to postero-lateral branch (PL)]. Emergent coronary angiography revealed right coronary artery occlusion with well patent bypass grafts. Percutaneus coronary intervention (PCI) was performed successfully, but 9 hours later, ventricular septal perforation (VSP) was occurred. Swan-Ganz catheter revealed that pulmonary to systemic blood flow ratio (Qp/Qs) was 2.6. In spite of intensive medical care, his hemodynamics was gradually exacerbated. Subsequent intracavitary repair with equine pericardial patch, sutured using interrupted mattress sutures with felt pledgets, was performed. He had an uneventful recovery thereafter, extubated and weaned from an intra-aortic balloon pumping at the 1st day. He was discharged from hospital on the 27th postoperative day.

[Endovascular stent-grafting for mycotic thoracic aortic aneurysm]

We report 3 cases of endovascular stent-grafting (ESG) for mycotic thoracic aortic aneurysm. The case 1 was a rupture of pseudoaneurysm of the descending aorta caused by mediastinitis due to perforation of esophageal ulcer. The patient underwent emergent ESG for temporary control of the rupture. He underwent esophagus reconstruction 5 month after ESG. The case 2 was admitted due to inflammatory reaction. She was diagnosed with mycotic descending aortic aneurysm and underwent elective ESG because of her old age. Her postoperative course was uneventful and no infection recurred. The case 3 underwent ESG for a ruptured mycotic descending aortic aneurysm. But 113 days after ESG, he underwent ESG again for a ruptured endoleak of the stentgraft. His blood culture demonstrated methillin-resistant Staphylococcus aureus (MRSA). He died of rupture to bronchus and esophagus at 18th day after ESG. We believe that ESG is useful in high risk patients for temporary management of the rupture.

[Successful consecutive seven time's surgical repair of Marfan syndrome]

We report a patient with Marfan syndrome who received successful 7 consecutive operations during 11 years. She underwent descending aortic replacement for chronic type B dissection at the age of 24. Mitral valve replacement (MVR) was performed for mitral regurgitation (MR) at the age of 30, and abdominal aortic replacement was done for persistent dissection at the age of 31, aortic root and arch replacement was done at the age of 34. The 9 months later, she received re-MVR for dysfunction of bioprosthesis and tricuspid valve anuloplasty (TAP) for tricuspid regurgitation (TR). But severe paravalvuler leakage of mitral valve necessitated direct closure of detachment. Thoracoabdominal replacement was performed for rupture of persistent dissection at the age of 35. She was discharged on the 54th day after the 7th surgery.

[Left atrial myxoma combined with coronary artery bypass grafting]

We experienced 2 cases of surgical treatment for left atrial myxoma combined with coronary artery bypass grafting (CABG) using only in situ arterial grafts. A 58-year-old man who had undergone CABG [left internal thoracic artery (LITA)-right coronary artery (RCA) and saphenous vein graft (SVG)-left anterior descending artery (LAD)] 14 years before was admitted to our hospital, complaining of anterior chest pain. Coronary arteriography demonstrated total occlusion of the LAD and RCA, as well as the stenosis of high lateral branch (HL) and SVG. Left atrial myxoma was incidentally detected by echocardiography. Myxoma was resected at first, and then the right internal thoracic artery (RITA) was anastomosed to the LAD. The postoperative course was uneventful. A 69-year-old woman was admitted to another hospital, complaining of chest pain and dyspnea. Coronary arteriography revealed stenosis of LAD, left circumflex artery (LCx) and HL, as well as left main trunk (LMT). Left atrial myxoma was incidentally detected by echocardiography. Myxoma was resected at first, and then CABG [LITA-HL, gastroepiploic artery (GEA)-RCA and RITA-LAD] was carried out. The postoperative course was uneventful. The priority between CABG and the surgical treatment for cardiac myxoma remains controversial from the point of view of myocardial protection and prevention of systemic embolism of myxomal fragment.

MUC 1 core protein as a marker of gallbladder malignancy

AIM

The significance of MUC 1 expression in the gallbladder tissues in relation to cancer and non-cancer disease is not well understood. The aim of this study was to clarify the significance of MUC 1 expression.

MATERIALS AND METHODS

A monoclonal antibody (CA 15--3; DF 3) was applied to stain MUC 1 core protein in surgical specimens.

RESULTS

MUC 1 expression is significantly higher (p<0.0001) in gallbladder cancer (69/88) compare to non-cancerous tissue, while, very trace in normal and inflammatory tissues. The expression rate was significantly lower (p<0.0001) when the cancer did not penetrate the mucosal layer than when cancers did penetrate this layer. The MUC 1 expression rate was (4/14) in T1 tumours, (11/14) in T4, (40/45) in T3, and (14/15) in T2, respectively. Every cell of normal and inflammatory mucosa, and T1 cancers had the polarized pattern. The depolarized pattern was dominant in cancer cells from the advanced tumours of T2, T3 and T4. That is, (45/74) of cancer cells from the mucosal layer and (58/74) of penetrating cancer cells in submucosal layer had the depolarized pattern. There was no significant correlation of MUC 1 expression rate and staining pattern with cancer differentiation and microscopic venous invasion. On the other hand, lymphatic vessel invasion was significantly correlated with the staining pattern but not with expression rate.

CONCLUSION

MUC 1 core protein expression rate and pattern are suggesting that MUC 1 core protein would be a marker of malignant transformation of gallbladder epithelium and its depolarized expression would also be a marker of invasion of gallbladder cancer.

Augmentation of antitumor immune responses after adoptive transfer of bone marrow derived from donors immunized with tumor lysate-pulsed dendritic cells

We demonstrated previously that tumor lysate-pulsed dendritic cells (TP-DC) could mediate a specific and long-lasting antitumor immune response against a weakly immunogenic breast tumor during early lymphoid reconstitution. The purpose of this study was to examine the potential therapeutic efficacy of bone marrow transplants from TP-DC-vaccinated donors. In 2 aggressive metastatic models, bone marrow transplantation with donor bone marrow cells from TP-DC-immunized mice mediated a tumor-specific immune response in the recipient, and this caused regressions of preexisting tumor metastases. After vaccination with TP-DC, donors harbored increased numbers of both activated CD4+ and CD8+ T-cell populations in the bone marrow. Adoptive transfer of T cells purified from the bone marrow of TP-DC-vaccinated mice led to a reduction in preestablished lung metastases, whereas depletion of T cells from bone marrow abolished this effect. By using T cells derived from the bone marrow of TP-DC-vaccinated major histocompatibility complex class I and class II knockout mice, the effector cells required for the observed antitumor effect were determined to be major histocompatibility complex class I-restricted CD8+ T cells. Additionally, the tumor burden in TP-DC-immunized transplant recipients could be reduced further by repetitive TP-DC immunizations after bone marrow transplantation. Collectively, these results demonstrate an important therapeutic role of bone marrow from TP-DC-immunized donors and raise the potential for this approach in patients with advanced cancer.

Industry forum: Progress in pursuit of therapeutic A2A antagonists: The adenosine A2A receptor selective antagonist KW6002: Research and development toward a novel nondopaminergic therapy for Parkinson's disease

Research and development of the adenosine A2A receptor selective antagonist KW6002 have focused on developing a novel nondopaminergic therapy for Parkinson's disease (PD). Salient pharmacologic features of KW6002 were investigated in several animal models of PD. In rodent and primate models, KW6002 provides symptomatic relief from parkinsonian motor deficits without provoking dyskinesia or exacerbating existing dyskinesias. The major target neurons of the A2A receptor antagonist were identified as GABAergic striatopallidal medium spiny neurons. A possible mechanism of A2A receptor antagonist action in PD has been proposed based on the involvement of striatal and pallidal presynaptic A2A receptors in the "dual" modulation of GABAergic synaptic transmission. Experiments with dopamine D2 receptor knockout mice showed that A2A receptors can function and anti-PD activities of A2A antagonists can occur independent of the dopaminergic system. Clinical studies of KW6002 in patients with advanced PD with L-dopa-related motor complications yielded promising results with regard to motor symptom relief without motor side effects. The development of KW6002 represents the first time that a concept gleaned from A2A biologic research has been applied successfully to "proof of concept" clinical studies. The selective A2A antagonist should provide a novel nondopaminergic approach to PD therapy.

Synthesis and antiherpesvirus activities of 5-alkyl-2-thiopyrimidine nucleoside analogues

Twenty 5-alkyl-2-thiopyrimidine nucleosides were newly synthesized and examined for antiviral activities against herpes simplex virus (HSV), varicella-zoster virus (VZV) and human cytomegalovirus (HCMV). In this study, 2'-deoxy-5-alkyl-2-thiocytidine analogues had lower 50% effective concentration (EC50) values against HSV-1, and 2'-deoxy-5-alkyl-2-thiouridine analogues showed lower EC50 against VZV than their congeners of arabinoside form. Among the compounds examined, 2'-deoxy-5-ethyl and 5-propyl-2-thiocytidine (TN-53 and TN-54) were most potent and selective anti-HSV compounds. Their EC50s were 0.04 and 0.15 microM, and selectivity indexes were more than 7,215 and 1,849, respectively. On the other hand, 2'-deoxy-5-propyl-2-thiouridine (TN-51), 5-bromovinyl-2-thiouracil arabinoside (TN-65) and 5-styryl-2-thiouracil arabinoside (TN-67) were most potent and selective anti-VZV compounds. Their EC50s were 3.1, 3.8 and 2.6 pM for CaQu strain of VZV, respectively, and 2.1 to 3.0 times lower than that of acyclovir. All 2-thiopyrimidine nucleoside analogues did not show antiviral activities against thymidine kinase (TK) negative strains of HSV-1 and VZV. Only three 2-thiocytosine arabinoside compounds showed marginal anti-CMV activities (EC50s were 57-159 pM). All of the five alkyl-2-thio-pyrimidine nucleoside analogues examined were not cytotoxic to human lymphoblastoid cells (RPM18226) and human embryonic fibroblast cells (MRC-5) at 240 microM (100 microg/ml) or more. Regarding the structure-activity relationship of 5-alkyl-2-thiopyrimidine nucleoside analogues, the following remarks will be noted. Elongation of 5-alkyl chain (methyl to ethyl) of 2-thiocytosine in both deoxyribosyl and arabinosyl nucleosides increased anti-HSV-1 activity but not anti-VZV activity. Furthermore, elongation of the same chain (ethyl to propyl) of 2-thiodeoxyuridine increased anti-VZV activity whereas it did not in the case of 2-thiouracil arabinosides.

Transition and improvement in surgical treatment for rectal cancer during the last 21 years in our department

The subject of this study was to examine the net effect of numerous changes in basic strategies, personnel and devices, upon the clinical courses and outcomes of rectal cancer patients. A total of 151 rectal cancer patients who underwent low anterior resection were divided into 4 groups (period 1 to 4) based upon the time period of the operation. They were compared among groups based upon the following parameters: blood loss, operation time, incidence of leakage and urinary dysfunction, incidence of ileus, duration of naso-gastric tube insertion, timing of initial oral feeding and survival. The blood loss during the operations, urinary dysfunction and duration of naso-gastric tube insertion tended to decrease in every period. Timing of initial oral feeding became faster. The operation times, incidence of leakage and ileus were nearly the same in each period. The 5-year survival rates on Dukes' C cases were 100% in period 4, 82.4% in period 3 and 50% in period 2. Survival rates became better. Our net outcome for rectal cancer treatment was satisfactory, because the survival rates became better under function preserving strategies.

[Right ventricular outflow tract reconstruction using a three-valved extracardiac conduit of expanded polytetrafluoroethylene vessel graft in the Ross operation: a pediatric case report]

A 16-year-old boy was diagnosed as having severe aortic regurgitation and moderate aortic stenosis due to congenital aortic bicuspid valve. A chest X-ray film showed the cardiothoracic ratio (CTR) of 64% and echocardiography revealed severe dilation of the left ventricular dimension with severe wall thickness. An electrocardiogram showed multiple ventricular arrhythmias. The patient underwent the Ross operation with the reconstruction between the right ventricle and the pulmonary arteries using a three-valved conduit which was made by an expanded polytetrafuloroethylene vessel graft. Ventricular arrhythmia disappeared just after the operation and left ventricular dimensions improved with the CTR of 53% except mild regurgitation of the neo-aortic valve three months later.

Pim-1 translocates sorting nexin 6/TRAF4-associated factor 2 from cytoplasm to nucleus

Pim-1, an oncogene product of serine/threonine kinase, has been found to play roles in apoptosis induction/suppression, cell-cycle progression and transcriptional regulation by phosphorylating the target proteins involved in these processes. The target proteins phosphorylated by Pim-1, including p100, Cdc25A, PAP-1 and heterochromatin protein 1, have been identified. The precise functions of Pim-1, however, are still poorly understood. In this study, we identified tumor necrosis factor receptor-associated factor 4-associated factor 2/sorting nexin 6 (TFAF2/SNX6) as a Pim-1-binding protein, and we found that TFAF2/SNX6 was phosphorylated and translocated from the cytoplasm to nucleus by Pim-1. This translocation of the protein was not affected by Pim-1-dependent phosphorylation. Since sorting nexins, including TFAF2/SNX6, have been reported to be located in the cytoplasm or membrane by association with several receptors of tyrosine- or serine/threonine-kinase, this is the first report of TFAF2/SNX6 being located in the nucleus after binding to Pim-1.

[Chemoradiotherapy and salvage surgery in a patient with advanced esophageal cancer]

We report a case of advanced esophageal cancer, which was treated by chemoradiotherapy combined with surgical treatment. Moreover, 14 advanced esophageal cancer patients treated by chemoradiotherapy are discussed. The chemoradiotherapy showed beneficial control of the tumor; however, it sometimes leads to esophageal stenosis and ulcer. We conclude that additional salvage surgery is needed for such complications.

Cellular integration of thyrocytes and thyroid folliculogenesis: a perspective for thyroid tissue regeneration and engineering

Thyroid gland is composed of many spheroid structures called thyroid follicles, in which thyrocytes are integrated in their specific structural and functional polarization. In conventional monolayer and floating cultures, the cells cannot reorganize follicle structures with normal polarity. By contrast, in a 3-D collagen gel culture thyrocytes easily and stably reconstruct follicles with physiological polarity. Integration of thyrocyte growth and differentiation appears to result in eventual thyroid folliculogenesis. 3-D collagen gel culture and subacute thyroiditis, a specific thyroid disorder, are the promising models for addressing the mechanism of thyroid folliculogenesis. Because formation of 3-D follicles actively occurs both in this culture system and at the regenerative stage of the disease. The understanding of the mechanistic basis of folliculogenesis is prerequisite for establishment of an artificial thyroid tissue, which would enable a more physiological approach to the treatment of hypothyroidism caused by various diseases and surgical processes than conventional hormone replacement therapy. In this review, we have discussed thyrocyte integration, and thyroid folliculogenesis and tissue regeneration, to further thyroid biology. Also, we briefly discussed a perspective on thyroid tissue regeneration and engineering.

Thyrocyte integration, and thyroid folliculogenesis and tissue regeneration: perspective for thyroid tissue engineering

The thyroid gland is composed of many ball-like structures called thyroid follicles, which are supported by the interfollicular extracellular matrix (ECM) and a capillary network. The component thyrocytes are highly integrated in their specific structural and functional polarization. In conventional monolayer and floating culture systems, thyrocytes cannot organize themselves into follicles with normal polarity. In contrast, in 3-D collagen gel culture, thyrocytes easily form stable follicles with physiological polarity. Integration of thyrocyte growth and differentiation results ultimately in thyroid folliculogenesis. This culture method and subacute thyroiditis are two promising models for addressing mechanisms of folliculogenesis, because thyroid-follicle formation actively occurs both in the culture system and at the regenerative phase of the disorder. The understanding of the mechanistic basis of folliculogenesis is prerequisite for generation of artificial thyroid tissue, which would enable a more physiological strategy to the treatment of hypothyroidism caused by various diseases and surgical processes than conventional hormone replacement therapy. We review here thyrocyte integration, and thyroid folliculogenesis and tissue regeneration. We also briefly discuss a perspective for thyroid tissue regeneration and engineering.

Light-use properties in two sun-adapted shrubs with contrasting canopy structures

We investigated the impact of high solar irradiance and elevated temperature on carbon gain by two, co-occurring, sun-adapted, dwarf shrub species, Planchonella obovata var. dubia (Koidz.) Hatusima and Hibiscus glaber Matsumura, growing on sun-exposed ridges in the Bonin Islands, in the subtropical Pacific Ocean. Planchonella had steeply inclined, longer lived, sclerophyllous leaves, whereas Hibiscus has thinner, more horizontally oriented, and shorter lived leaves. We tested the hypothesis that leaf physiological tolerance to high light is lower in Planchonella than in Hibiscus. Under relatively high irradiances (photosynthetic photon flux density, PPFD, > 500 micromol m(-2) s(-1)), net photosynthetic rate (P(n)) was about 8.0 and 0.4 micromol m(-2) s(-1) in mature and young leaves of Planchonella, and about 12.4 and 10.3 micromol m(-2) s(-1) in mature and young leaves of Hibiscus, respectively. Both P(n) and photosystem II (PSII) quantum yield at a given PPFD were lower in Planchonella than in Hibiscus, whereas non-photochemical quenching (NPQ) at a given PPFD was higher in Planchonella. When leaf discs were exposed to high light (1900 micromol m(-2) s(-1) PPFD) at 37, 40 or 43 degrees C for 3 h, the recovery of PSII quantum yield (F(v)/F(m)) in the following 60-min dark period was slower in Planchonella than in Hibiscus, indicating that the ability of PSII to tolerate high light and high temperature was less in Planchonella than in Hibiscus. We postulate that there is a linkage between leaf display and leaf photochemical ability in sun-adapted shrub species.