Breaking the Limit of Cardiovascular Regenerative Medicine: Successful 6-Month Goat Implant in World's First Ascending Aortic Replacement Using Biotube Blood Vessels.

This study investigated six-month outcomes of first models of ascending aortic replacement. The molds used to produce the Biotube were implanted subcutaneously in goats. After 2-3 months, the molds were explanted to obtain the Biotubes (inner diameter, 12 mm; wall thickness, 1.5 mm). Next, we performed ascending aortic replacement using the Biotube in five allogenic goats. At 6 months, the animals underwent computed tomography (CT) and histologic evaluation. As a comparison, we performed similar surgeries using glutaraldehyde-fixed autologous pericardial rolls or pig-derived heterogenous Biotubes. At 6 months, CT revealed no aneurysmalization of the Biotube or pseudoaneurysm formation. The histologic evaluation showed development of endothelial cells, smooth muscle cells, and elastic fibers along the Biotube. In the autologous pericardium group, there was no evidence of new cell development, but there was calcification. The histologic changes observed in the heterologous Biotube group were similar to those in the allogenic Biotube group. However, there was inflammatory cell infiltration in some heterologous Biotubes. Based on the above, we could successfully create the world's first Biotube-based ascending aortic replacement models. The present results indicate that the Biotube may serve as a scaffold for aortic tissue regeneration.

Change of dexmedetomidine and midazolam concentrations by simultaneous injection in an in vitro extracorporeal circuit.

PURPOSE: Patient sedation and analgesia are vital for safety and comfort during extracorporeal membrane oxygenation (ECMO). However, adsorption by the circuit may alter drug pharmaco-kinetics and remains poorly characterized. This study is the first to examine the concentrations of DEX and MDZ in the presence of drug-drug interactions using an in vitro extracorporeal circuit system that incorporates a polymer-coated polyvinyl chloride tube, but not a membrane oxygenator. METHODS AND RESULTS: Nine in vitro extracorporeal circuits were prepared using polymer-coated PVC tubing. Once the circuits were primed and running, either a single drug or two drugs were injected as boluses into the circuit with three circuits per drug. Drug samples were drawn following injection at 2, 5, 15, 30, 60, and 120 min and at 4, 12, and 24 h. They were then analyzed using high-performance liquid chromatography with mass spectrometry. When compared with an injection of DEX alone, the combination of DEX and MDZ is highly changed, with DEX and MDZ affecting the availability of free drugs in the circuit. CONCLUSIONS: The change of DEX and MDZ concentrations was confirmed by a combination of both drugs as compared with either single-infusion DEX or MDZ in an in vitro extracorporeal circuit. Drug-drug interactions developed between DEX and MDZ through albumin in an extracorporeal circuit; as a result, the unbounded drugs might change in the circuit.

A new anticoagulation strategy using recombinant human thrombomodulin in patients on veno-venous extracorporeal membrane oxygenation: a retrospective study.

BACKGROUND: During veno-venous extracorporeal membrane oxygenation (VV-ECMO), systemic anticoagulation is required to prevent thrombotic complications within the circuit and oxygenator. The unfractionated heparin (UFH) is commonly administered as a standard anticoagulant, but in our institute recombinant human thrombomodulin (rhTM), instead of UFH, is used as an anticoagulant for VV-ECMO. In the present study, we reviewed whether rhTM could be applied effectively and safely as an anticoagulant agent during VV-ECMO. METHODS: All 15 patients with severe respiratory failure on VV-ECMO were analyzed retrospectively. The following data were collected: age, gender, underlying disease, APACHE-II score, SOFA score, Japanese association for acute medicine (JAAM) DIC score, the usage of anticoagulants, time course of coagulationrelated parameters during ECMO, hemorrhagic and thrombotic complications. RESULTS: The median age of the patients was 73 years. The median JAAM DIC score at day 0 was 5 points, indicating that 13 patients were diagnosed with DIC at the initiation of VV-ECMO. The total number of days of VV-ECMO runs combined was 193 days, with a median duration of VV-ECMO of 9 days. Among the 15 VV-ECMO runs, rhTM was used as monotherapy in 5 runs, and a combination of rhTM and (antithrombin) AT was used in 8 runs. UFH was used in combination with rhTM in only 2 runs. Median ACT and aPTT remained a little longer than normal range over the course of the 14 days of a VV-ECMO run. Bleeding events were observed in 6 cases (40%) and no major thromboses were observed in all patients. CONCLUSIONS: In this retrospective study, we analyzed 15 patients with severe respiratory failure who were administered rhTM as an anticoagulant during VV-ECMO and found that anticoagulation therapy with rhTM is maybe a feasible option which allows for effective and safe VV-ECMO.

In vitro evaluation of the hemostatic effect of method involving the combined use of Hydrofit® and Spongel®.

OBJECTIVE: We developed an effective hemostatic method using Hydrofit® and a hemostatic gelatin sponge (Spongel®). We evaluated the hemostatic effect in comparison to the conventional silicone sheet method. METHODS: A simulated circuit was created using the pump of a Nipro ventricular assist system and a prosthetic graft. A hole was made in the graft by a needle and three hemostatic methods were applied: the silicone sheet method (SS) using Hydrofit® and a silicone sheet, the bread and butter method (BB) using Hydrofit® and a gelatin sponge instead of a silicone sheet, and French toast method (FT) using Hydrofit® and a gelatin sponge over which water was poured before compression. The amount of leakage before and after the application each of the methods was measured according to the compression time. RESULTS: In the 60 s compression, the amount of leakage after SS, BB, and FT was 0.4 ± 0.8, 0.2 ± 0.6, and 0 ± 0.0 ml, respectively, and FT showed no leakage. In the 30 s compression, the amount of leakage after SS, BB, and FT was 14.2 ± 27.9, 1.0 ± 3.2, and 7.8 ± 22.6 ml, respectively, and did not differ to a statistically significant extent. CONCLUSIONS: The method of combining Hydrofit® and Spongel® could obtain reliable hemostasis in 60 s.

Potential utility of new surgical hemostatic film using Hydrofit®: a preliminary study.

We developed a surgical hemostatic film using Hydrofit® (Hydrofit® film). This film is prepared by reacting Hydrofit® with water in advance, and it can be used in the same way as an accessory silicone sheet. In addition, unlike the silicone sheet, there is no need to remove the Hydrofit® film from the body. In the present study, we describe the hemostatic effect of our new method using Hydrofit® film. We created a pulsatile flow circuit model using a ventricular assist device and a vascular graft. The circuit was filled with water, and the systolic pressure was adjusted to ≥ 130 mmHg. The artificial blood vessel was punctured by an 18-G needle. Operations to prevent water from leaking were attempted through either a conventional method using a silicone sheet or our new method using Hydrofit® film. In the 180-s trial, 14 attempts (93.3%) with the Hydrofit® film were successful. In the silicone sheet group, 13 attempts (86.7%) were successful before the silicone sheet was peeled off, and hemostasis was maintained in 10 (66.5%) cases after the silicone sheet was removed. After short-duration hemostasis for 60 s, good waterproofing was obtained in the Hydrofit® film group (success in 17 cases [85%]). In contrast, in the silicone sheet group, 10 attempts (50%) were successful before the silicone sheet was peeled off, and hemostasis was maintained in only 7 (35%) cases after the silicone sheet was removed. Hydrofit® film showed good hemostatic performance in the pulsatile flow circuit model.

Toll ligand Spätzle3 controls melanization in the stripe pattern formation in caterpillars.

A stripe pattern is an aposematic or camouflage coloration often observed among various caterpillars. However, how this ecologically important pattern is formed is largely unknown. The silkworm dominant mutant Zebra (Ze) has a black stripe in the anterior margin of each dorsal segment. Here, fine linkage mapping of 3,135 larvae revealed a 63-kbp region responsible for the Ze locus, which contained three candidate genes, including the Toll ligand gene spätzle3 (spz-3). Both electroporation-mediated ectopic expression and RNAi analyses showed that, among candidate genes, only processed spz-3 induced melanin pigmentation and that Toll-8 was the candidate receptor gene of spz-3 This Toll ligand/receptor set is also involved in melanization of other mutant Striped (pS ), which has broader stripes. Additional knockdown of 5 other spz family and 10 Toll-related genes caused no drastic change in the pigmentation of either mutant, suggesting that only spz-3/Toll-8 is mainly involved in the melanization process rather than pattern formation. The downstream pigmentation gene yellow was specifically up-regulated in the striped region of the Ze mutant, but spz-3 showed no such region-specific expression. Toll signaling pathways are known to be involved in innate immunity, dorsoventral axis formation, and neurotrophic functions. This study provides direct evidence that a Toll signaling pathway is co-opted to control the melanization process and adaptive striped pattern formation in caterpillars.

siRNAs induce efficient RNAi response in Bombyx mori embryos.

Short interference RNA (siRNA) is widely used in mammalian cells. In insects, however, reports concerning the suitablility of siRNA in vivo is very limited compared with that of long dsRNA, which is thought to be more effective. There is insufficient information on the essential rules of siRNA design in insects, as very few siRNAs have been tested in this context. To establish an effective method of gene silencing using siRNA in vivo in insects, we determined the effects of siRNA on seven target genes. We designed siRNAs according to a new guideline and injected them into eggs of Bombyx mori. At the mRNA level, the expression of most of these genes was successfully silenced, down to less than half the constitutive level, which in some cases led to the development of distinctive phenotypes. In addition, we observed stronger effect of siRNA both on the mRNA level and the phenotype than that of long dsRNA under comparable conditions. These results indicate that direct injection of siRNA is an effective reverse-genetics tool for the analysis of embryogenesis in vivo in insects.

Novel strategy for orbital tumor resection: surgical "displacement" into the maxillary cavity.

Surgical intervention consisting of lateral orbitotomy, the indication of which is extremely wide for orbital tumor surgery, has been applied in cases of large, retrobulbar cavernous hemangioma. However, no method exists involving displacement of the tumor from the crowded orbital contents, with the exception of tumor traction toward the outer side. The impact of traction force on the fragile hemangioma is extremely traumatic and dangerous. The authors examined how a tumor might be "displaced" in the absence of traction force effect, into an appropriate cavity neighboring the orbit. The maxillary sinus may afford the most suitable space to shift the laterally situated orbital tumor. Thus, the osteotomy level was extended to the lateral half of the inferior orbital floor and orbital rim in order to displace the tumor through an "escape window" of sufficient size between the orbit and maxilla. This report describes the treatment of two cases with long histories of progressive proptosis associated with retrobulbar large cavernous hemangiomas. This novel procedure resulted in a successful outcome. The current approach and management, which involves displacement of the tumor into the maxillary sinus through the orbital floor escape window, is a novel procedure for orbital tumor surgery.