Muscular Tissue Engineering: Capillary-Incorporated Hybrid Muscular Tissues in Vivo Tissue Culture

Requirements for a functional hybrid muscular tissue are 1) a high density of multinucleated cells, 2) a high degree of cellular orientation, and 3) the presence of a capillary network in the hybrid tissue. Rod-shaped hybrid muscular tissues composed of C2C12 cells (skeletal muscle myoblast cell line) and type I collagen, which were prepared using the centrifugal cell-packing method reported in our previous article, were implanted into nude mice. The grafts, comprised three hybrid tissues (each dimension, diameter, approximately 0.3 mm, length, approximately 1 mm, respectively), were inserted into the subcutaneous spaces on the backs of nude mice. All nude mice that survived the implantation were sacrificed at 1, 2, and 4 wk after the implantation. The grafts were easily distinguishable from the subcutaneous tissues of host mice with implantation time. The grafts increased in size with time after implantation, and capillary networks were formed in the vicinities and on the surfaces of the grafts. One week after implantation, many capillaries formed in the vicinities of the grafts. In the central portion of the graft, few capillaries and necrotic cells were observed. Mononucleated myoblasts were densely distributed and a low number of multinucleated myotubes were scattered. Two weeks after implantation, the formation of a capillary network was induced, resulting in the surfaces of the grafts being covered by capillaries. Numerous elongated multinucleated myotubes and mononucleated myoblasts were densely distributed and numerous capillaries were observed throughout the grafts. Four weeks after implantation a dense capillary network was formed in the vicinities and on the surfaces of the grafts. In the peripheral portion of the graft, multinucleated myotubes in the vicinities of the rich capillaries were observed. Thus, hybrid muscular tissues in vitro preconstructed was remodeled in vivo, which resulted in facilitating the incorporation of capillary networks into the tissues. © 1998 Elsevier Science Inc.

Venous Reconstruction Using Hybrid Vascular Tissue Composed of Vascular Cells and Collagen: Tissue Regeneration Process

In this study, a tubular hybrid vascular tissue composed of vascular cells and collagen was implanted as a venous substitute, and its remodeling process was histologically investigated. First, a hybrid medial tissue was prepared by pouring a cold mixed solution of canine jugular smooth muscle cells (SMCs) and Type I collagen into a tubular glass mold and subsequent incubation at 37°C. Culture in medium for 10 days produced a dense tubular tissue. Seeding of jugular endothelial cells (ECs) onto the luminal surface of the tissue produced a hybrid vascular tissue with a hierarchical structure. These vascular tissues (inner diameter, 7 mm; length, 3 cm; wall thickness, 1 mm; n = 14) were implanted autologously in the canine posterior vena cava wrapped in Dacron mesh for up to 24 wk. Nine of 14 grafts were patent throughout implantation. In patent grafts, monolayered ECs were oriented in the direction of blood flow at 1 wk. Circumferentially oriented SMCs accumulated at the subendothelial layer and ingrown fibroblasts were sparsely distributed throughout the wall at 12 wk. Contractile phenotype of SMCs was evident at 24 wk. Collagen fibrils, which were sparsely distributed at an early period of implantation, gradually assembled to form fibrous meshes at 24 wk. Sheet-like elastic lamellae were also observed at this time. Marked wall thinning was observed at 12 and 24 wk. The resultant tissues became highly dense. The specific gravity of tissues increased with time, and reached those of natural vessels at 24 wk. Tissue remodeling progressed in a time-dependent manner and appeared to be almost complete within 6 mo of implantation.

Quantitative Analysis of Unidirectional 2-D Tissue Formation of Endothelial Cells

We developed a reliable and quantitative method for measuring the dynamic process of unidirectional two-dimensional (2-D) tissue formation of endothelial cells (ECs) in vitro. The culturing of bovine ECs in an assembled culture chamber provided a square monolayered cell sheet with a linear margin when disassembled at the confluency. The cell sheet maintained in culture showed a unidirectional endothelialization in vitro. The cell population-distance histogram, which was determined from the daily observation of tissue, allowed us to determine quantitatively the dynamic process of unidirectional endothelialization in vitro. The endothelialized distance and the endothelializing zone on a glass slide were found to be nearly 500 μm/day and 750 μm in width, respectively. Thus, the method developed here provided information of the 2-D tissue formation process. This model would be useful as an in vitro model which simulates the anastomotic endothelialization of an artificial vascular graft.

Hybrid Muscular Tissues: Preparation of Skeletal Muscle Cell-Incorporated Collagen Gels

We prepared three different types of hybrid muscular tissues in which C2C12 cells (skeletal muscle myoblast cell line) were incorporated in type I collagen gels and then differentiated to myotubes upon culture: a disctype, a polyester mesh-reinforced sheet-type, and a tubular type. A cold mixed solution of the cells and type I collagen was poured into three different types of molds and was kept at 37°C in an incubator to form C2C12 cell-incorporated gels. A polyester mesh was incorporated into a gel to form the sheet-type tissue. The tubular hybrid tissue was prepared by pouring a mixed solution into the interstitial space of a tubular mold consisting of an outer sheath and a mandrel and subsequently culturing after removal of the outer sheath. Hybrid tissues were incubated in a growth medium (20% fetal bovine serum medium) for the first 4 days and then in a differentiation medium (2% horse serum medium) to induce formation of myotubes. Transparent fragile gels shrank with time to form opaque gels, irrespective of type, resulting in the formation of quite dense hybrid tissues. On day 14 of incubation, myoblasts fused and differentiated to form multinucleated myotubes. For a tubular type hybrid tissue, both cells and collagen fiber bundles became circumferentially oriented with incubation time. Periodic mechanical stress loading to a mesh-reinforced hybrid tissue accelerated the cellular orientation along the axis of the stretch. The potential applications for use as living tissue substitutes in damaged and diseased skeletal and cardiac muscle and as vascular grafts are discussed.

Phenotypic Reversion of Smooth Muscle Cells in Hybrid Vascular Prostheses

Our purpose was to evaluate whether or not and when phenotypic modulation of smooth muscle cells (SMCs) in hybrid vascular prostheses preincorporated with SMCs occurs upon implantation. Two types of hybrid vascular grafts incorporated with vascular cells derived from canine jugular veins were prepared: grafts containing a collagen gel layer covered with an endothelial monolayer at the luminal surface (Model I graft) and those containing an endothelial monolayer and SMC multilayer (Model II graft). They were bilaterally implanted into carotid arteries of the same dogs from which the cells had been harvested for 2 wk (n = 3) and 12 wk (n = 3). The time-dependent changes in populations of three SMC phenotypes (synthetic, intermediate, and contractile) in the neoarterial layers were quantified by morphometric evaluation using a transmission electron microscope in hybrid vascular grafts. Before implantation, all the SMCs were of the synthetic phenotype. In Model II grafts at 2 wk, synthetic and intermediate SMCs were dominant especially in the luminal layer. On the other hand, neoarterial layers at 12 wk were dominated by contractile SMCs, which were evenly distributed throughout the entire neoarterial tissues. A markedly delayed phenotypic reversion was noted for the Model I grafts at 12 wk. In the hybrid grafts, during about 3 mo of implantation, neoarterial SMCs transformed from the synthetic to the contractile phenotypes, which was promoted by SMC incorporation.

Tissue Engineered Skeletal Muscle: Preparation of Highly Dense, Highly Oriented Hybrid Muscular Tissues

We prepared highly dense, highly oriented hybrid muscular tissues that are composed of C2C12 cells (skeletal muscle myoblast cell line) and type I collagen. A cold mixture of C2C12 cells suspended in DMEM and type I collagen solution was poured into capillary tube molds of two different sizes (inner diameters; 0.90 and 0.53 mm, respectively). One end of each mold was sealed. Upon centrifugation (1000 rpm, 5 min) and subsequent thermal gelation, a rod-shaped gel was obtained. It was cultured in an agarose gel-coated dish for 7 days (first for 3 days in a growth medium and then for 4 days in a differentiation medium), during which time it shrank to become a highly dense tissue. Small-diameter rod-shaped, highly dense cellular assemblages with multinucleated myotubes were formed and only few necrotic cells at the core of the tissue were observed. On the other hand, a ring-shaped tissue prepared using a specially devised agarose gel mold was subjected to cyclic stretching at 60 rpm, resulting in the formation of a highly dense, highly oriented hybrid muscular tissue in which both densely accumulated cells and collagen fiber bundles tended to be aligned in the direction of stretching. The hybrid muscular tissues that were prepared using via sequential procedures of a centrifugal cell packing method and a mechanical stress-loading method became closer to native muscular tissues in terms of cell density and orientation.

Self-Organized, Tubular Hybrid Vascular Tissue Composed of Vascular Cells and Collagen for Low-Pressure-Loaded Venous System

A tubular, hierarchically structured hybrid vascular tissue composed of vascular cells and collagen was prepared. First, a cold mixed solution of bovine aortic smooth muscle cells (SMCs) and Type I collagen was poured into a tubular glass mold composed of a mandrel and a sheath (example of dimensions: inner diameter, 1.5 mm; outer diameter, 7 mm; length, 7 cm). Upon incubation at 37°C, an SMC-incorporated collagenous gel was formed. After the sheath was removed, the resulting fragile tissue, when cultured in medium, thinned in a time-dependent manner to form an opaque, dense tissue. Higher SMC seeding density and lower initial collagen concentration induced more rapid and prominent shrinkage of the tissue. Morphologic investigation showed that over time, bipolarly elongated SMCs and collagen fiber bundles became positioned around the mandrel. Both components became circumferentially oriented. When the mandrel was removed, a tubular hybrid medial tissue was formed. A hybrid vascular tissue with a hierarchical structure was constructed by seeding endothelial cells onto the inner surface of the hybrid medial tissue. Prepared tissues tolerated luminal pressures as great as 100 mmHg and mechanical stress applied during an anastomotic procedure. This method allowed us to prepare a tubular hybrid medial tissue of predetermined size (inner diameter, wail thickness, and length) by selecting appropriate mold design, initial collagen concentration, and SMC seeding density. Such hybrid vascular tissues may provide physiological functions when implanted into the venous system.

Measurement of the τ Lepton Polarization and R(D^{*}) in the Decay B[over ¯]→D^{*}τ^{-}ν[over ¯]_{τ}

We report the first measurement of the τ lepton polarization P_{τ}(D^{*}) in the decay B[over ¯]→D^{*}τ^{-}ν[over ¯]_{τ} as well as a new measurement of the ratio of the branching fractions R(D^{*})=B(B[over ¯]→D^{*}τ^{-}ν[over ¯]_{τ})/B(B[over ¯]→D^{*}ℓ^{-}ν[over ¯]_{ℓ}), where ℓ^{-} denotes an electron or a muon, and the τ is reconstructed in the modes τ^{-}→π^{-}ν_{τ} and τ^{-}→ρ^{-}ν_{τ}. We use the full data sample of 772×10^{6}  BB[over ¯] pairs recorded with the Belle detector at the KEKB electron-positron collider. Our results, P_{τ}(D^{*})=-0.38±0.51(stat)_{-0.16}^{+0.21}(syst) and R(D^{*})=0.270±0.035(stat)_{-0.025}^{+0.028}(syst), are consistent with the theoretical predictions of the standard model.

Lepton-Flavor-Dependent Angular Analysis of B→K^{*}ℓ^{+}ℓ^{-}

We present a measurement of angular observables and a test of lepton flavor universality in the B→K^{*}ℓ^{+}ℓ^{-} decay, where ℓ is either e or μ. The analysis is performed on a data sample corresponding to an integrated luminosity of 711  fb^{-1} containing 772×10^{6} BB[over ¯] pairs, collected at the ϒ(4S) resonance with the Belle detector at the asymmetric-energy e^{+}e^{-} collider KEKB. The result is consistent with standard model (SM) expectations, where the largest discrepancy from a SM prediction is observed in the muon modes with a local significance of 2.6σ.

Observation of D^{0}→ρ^{0}γ and Search for CP Violation in Radiative Charm Decays

We report the first observation of the radiative charm decay D^{0}→ρ^{0}γ and the first search for CP violation in decays D^{0}→ρ^{0}γ, ϕγ, and K[over ¯]^{*0}(892)γ, using a data sample of 943  fb^{-1} collected with the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. The branching fraction is measured to be B(D^{0}→ρ^{0}γ)=(1.77±0.30±0.07)×10^{-5}, where the first uncertainty is statistical and the second is systematic. The obtained CP asymmetries A_{CP}(D^{0}→ρ^{0}γ)=+0.056±0.152±0.006, A_{CP}(D^{0}→ϕγ)=-0.094±0.066±0.001, and A_{CP}(D^{0}→K[over ¯]^{*0}γ)=-0.003±0.020±0.000 are consistent with no CP violation. We also present an improved measurement of the branching fractions B(D^{0}→ϕγ)=(2.76±0.19±0.10)×10^{-5} and B(D^{0}→K[over ¯]^{*0}γ)=(4.66±0.21±0.21)×10^{-4}.

Anti-anhedonic effect of selective serotonin reuptake inhibitors with affinity for sigma-1 receptors in picrotoxin-treated mice

BACKGROUND AND PURPOSE

Prefrontal dopamine release by the combined activation of 5-HT1A and sigma-1 (σ1 ) receptors is enhanced by the GABAA receptor antagonist picrotoxin in mice. Here, we examined whether this neurochemical event was accompanied by behavioural changes.

EXPERIMENTAL APPROACH

Male mice were treated with picrotoxin to decrease GABAA receptor function. Their anhedonic behaviour was measured using the female encounter test. The expression of c-Fos was determined immunohistochemically.

KEY RESULTS

Picrotoxin caused an anxiogenic effect on three behavioural tests, but it did not affect the immobility time in the forced swim test. Picrotoxin decreased female preference in the female encounter test and attenuated the female encounter-induced increase in c-Fos expression in the nucleus accumbens. Picrotoxin-induced anhedonia was ameliorated by fluvoxamine and S-(+)-fluoxetine, selective serotonin reuptake inhibitors with high affinity for the σ1 receptor. The effect of fluvoxamine was blocked by a 5-HT1A or a σ1 receptor antagonist, and co-administration of the σ1 receptor agonist (+)-SKF-10047 and the 5-HT1A receptor agonist osemozotan mimicked the effect of fluvoxamine. By contrast, desipramine, duloxetine and paroxetine, which have little affinity for the σ1 receptor, did not affect picrotoxin-induced anhedonia. The effect of fluvoxamine was blocked by a dopamine D2/3 receptor antagonist. Methylphenidate, an activator of the prefrontal dopamine system, ameliorated picrotoxin-induced anhedonia.

CONCLUSION AND IMPLICATIONS

Picrotoxin-treated mice show anhedonic behaviour that is ameliorated by simultaneous activation of 5-HT1A and σ1 receptors. These findings suggest that the increased prefrontal dopamine release is associated with the anti-anhedonic effect observed in picrotoxin-treated mice.

What factor within the Japanese Association for Acute Medicine (JAAM) disseminated intravascular coagulation (DIC) criteria is most strongly correlated with trauma induced DIC? A retrospective study using thromboelastometry in a single center in Japan

Purpose

The diagnostic criteria for disseminated intravascular coagulation (DIC) established by the Japanese Association for Acute Medicine (JAAM) is able to diagnose DIC accurately and promptly. The aim of this retrospective study is to evaluate the degree of association between each parameter of JAAM DIC criteria and the diagnosis of trauma induced DIC (T-DIC) utilizing thromboelastometry (ROTEM).

Methods

Trauma patients transported to our hospital with ROTEM performed in the emergency department between January 2013 and December 2015 were enrolled in this study. We evaluated (1) the characteristics of T-DIC, (2) the relationships between T-DIC and each parameter of the JAAM DIC criteria and (3) the diagnostic accuracies of each parameter for T-DIC by statistical measurement.

Results

All 72 patients (21 T-DIC and 51 control) were included in primary analysis. T-DIC was significantly related to younger age, more severe trauma scores, more cases of massive transfusions, and remarkable coagulation abnormality detected by standard coagulation tests. In the cases of T-DIC, ROTEM showed longer clotting time, lower acceleration, lower clot firmness, and inhibited fibrinolysis in EXTEM/INTEM. Within the JAAM DIC score, PT-INR ≥1.2 was the most accurate factor for T-DIC diagnosis; sensitivity 60.0%, specificity 100.0%, and accuracy 88.7%. PT-INR ≥1.2 was statistically correlated with the JAAM DIC score (p < 0.001, r = 0.709). The univariate analysis based on 1.2 of PT-INR indicated statistical differences in most categories of ROTEM, which is similar to analysis performed for the presence and absence of T-DIC.

Conclusions

Among JAAM DIC criteria, the PT-INR ≥1.2 was the most accurate factor for both the diagnosis of T-DIC and the evaluation of its severity.

Comparison of Cosmesis and Body Image After Laparoendoscopic Single-Site Versus Conventional Laparoscopic Donor Nephrectomy

BACKGROUND

This study used a questionnaire to objectively assess the body image of donors who underwent conventional laparoscopic donor nephrectomy (L-DN) or laparoscopic single-site donor nephrectomy (LESS-DN). Surgical outcomes were compared between the two groups.

METHODS

Twenty patients underwent L-DN and 20 underwent LESS-DN. The postoperative outcomes of the two approaches were retrospectively compared and evaluated for differences in cosmesis and body image. The questionnaire comprised a body image questionnaire, including a body image scale (BIS) and cosmetic scale (CS), and a photo-series questionnaire (PSQ). A higher score indicated a more favorable assessment. Pain was assessed by comparing the number of times an analgesic was administered during hospitalization.

RESULTS

There were no significant differences in operative outcomes between L-DN and LESS-DN. The average BIS score (maximum possible, 20 points) was 18.5 points for patients who underwent L-DN and 19.5 points for patients who underwent LESS-DN (P = .025). Patients who underwent L-DN had a median CS score (maximum possible, 24 points) of 17.5 points, whereas patients who underwent LESS-DN had a median CS score of 19.0 points (P = .113). The average PSQ score was 7.1 points for patients who underwent L-DN and 8.8 points for patients who underwent LESS-DN (P = .01). Patients who underwent LESS-DN were administered an analgesic was significantly number of times less than patients who underwent DN (P = .01).

CONCLUSIONS

LESS-DN results in a better body image and better cosmetic appearance than does L-DN, indicating the clinical usefulness of LESS-DN.

Increased expression of αv integrin as a regulator of fibrosis in Dupuytren's nodules

Although Dupuytren's contracture is characterized by increased transforming growth factor-β1 (TGF-β1) and fibrosis in the palmar fascia, the relationship between TGF-β1 and integrins, which are considered to be related to fibrosis, remains unclear. We investigated the involvement of TGF-β1 and integrins in the pathological palmar fascia of Dupuytren's contracture. Seven patients underwent partial fasciectomy for treatment of this disease. The nodule and cord were isolated from the fascial tissues of the patients. Control fasciae were obtained from seven patients with carpal tunnel syndrome. Immunohistochemical analysis was performed to detect the fibrosis marker α-smooth muscle actin and integrins in the fascial tissues. The expression of TGF-β1 and integrins was assessed by real-time polymerase chain reaction. The results suggest that nodules may be areas involved in activation of fibrosis in the fascia, associated with increased expression of TGF-β1 and αv integrin. Thus, αv integrin may contribute to fibrosis in Dupuytren's contracture by activating TGF-β1.

LEVEL OF EVIDENCE

IV.

Energy Scan of the e^{+}e^{-}→h_{b}(nP)π^{+}π^{-} (n=1, 2) Cross Sections and Evidence for ϒ(11020) Decays into Charged Bottomoniumlike States

Using data collected with the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider, we measure the energy dependence of the e^{+}e^{-}→h_{b}(nP)π^{+}π^{-} (n=1, 2) cross sections from thresholds up to 11.02 GeV. We find clear ϒ(10860) and ϒ(11020) peaks with little or no continuum contribution. We study the resonant substructure of the ϒ(11020)→h_{b}(nP)π^{+}π^{-} transitions and find evidence that they proceed entirely via the intermediate isovector states Z_{b}(10610) and Z_{b}(10650). The relative fraction of these states is loosely constrained by the current data: The hypothesis that only Z_{b}(10610) is produced is excluded at the level of 3.3 standard deviations, while the hypothesis that only Z_{b}(10650) is produced is not excluded at a significant level.

Temporomandibular Joint Movement

Ten temporomandibular joints (TMJs) of 5 healthy volunteers and 19 TMJs of internal derangements in 16 patients with splint therapy were examined with MR imaging. T1-weighted images were obtained only in the closed mouth position, and gradient recalled acquisition in steady state (GRASS) images were obtained in active opening and closing phases, allowing a pseudodynamic display of TMJ movement. All patients received protrusive splint treatment. The usefulness of MR imaging to assess the efficacy of splint therapy was evaluated. Corrected disk position with the splint in place was clearly demonstrated in 9 TMJs, corresponding with elimination of reciprocal clicking. Ten other TMJs of anterior disk displacement without reduction showed uncorrected disk position by the splint. This information could confirm the therapeutic efficacy, or suggest other treatment alternatives. GRASS MR imaging can provide accurate and physiologic information about disk function in initial and follow-up assessment of protrusive splint therapy.

Interference Effect between ϕ and Λ(1520) Production Channels in the γp→K^{+}K^{-}p Reaction near Threshold

The ϕ-Λ(1520) interference effect in the γp→K^{+}K^{-}p reaction has been measured for the first time in the energy range from 1.673 to 2.173 GeV. The relative phases between ϕ and Λ(1520) production amplitudes were obtained in the kinematic region where the two resonances overlap. The measurement results support strong constructive interference when K^{+}K^{-} pairs are observed at forward angles but destructive interference for proton emission at forward angles. Furthermore, the observed interference effect does not account for the sqrt[s]=2.1  GeV bump structure in forward differential cross sections for ϕ photoproduction. This fact suggests possible exotic structures such as a hidden-strangeness pentaquark state, a new Pomeron exchange, or rescattering processes via other hyperon states.

Elucidation of the mechanism of suppressed steroidogenesis during androgen deprivation therapy of prostate cancer patients using a mouse model

Androgen deprivation therapy (ADT) is the standard medical approach to the management of prostate cancer. Patients switched from a GnRH antagonist to a GnRH agonist, did not experience a testosterone surge in spite of the occurrence of luteinizing hormone (LH) surge in our protocol of clinical study. To clarify this observation, male mice pre-treated with two different doses of the GnRH antagonist degarelix for 28 days were further administered the GnRH agonist leuprolide or chorionic gonadotropin, and testosterone production of the mice was studied. Serum LH and testosterone levels, the size of Leydig cells, and expression level of steroidogenesis-related genes in the testis were analyzed. Treatment of mice with a high dose of degarelix (0.1 μg/mouse; HDG), but not a low dose (0.05 μg/mouse; LDG), for 28 days reproduced declined steroidogenesis observed in prostate cancer patients during ADT switched from a GnRH antagonist to a GnRH agonist. The size of the Leydig cells in the HDG mice was not significantly different from that in naive mice. Although expression levels of StAR, P450scc, and 17β HSD increased significantly in the LDH testis, those in the HDG testis did not change. Treatment of mice with a high dose of degarelix for 28 days reproduced the decline in steroidogenesis observed in prostate cancer patients during ADT. In this animal model, we demonstrated that initial ADT may inhibit the ability of Leydig cells to produce testosterone by suppressing the expression of genes involved in steroidogenesis, such as StAR, P450scc, and 17βHSD.

Spontaneous Polarization and Bulk Photovoltaic Effect Driven by Polar Discontinuity in LaFeO_{3}/SrTiO_{3} Heterojunctions

Structurally coherent and chemically abrupt interfaces formed between polar and nonpolar perovskite oxides provide an ideal platform for examining the purely electronic reconstruction known as the polar catastrophe and the emergence of mobile or bound charges at the interface. The appearance of mobile charges induced by the polar catastrophe is already established in the LaAlO_{3}/SrTiO_{3} heterojunctions. Although not experimentally verified, the polar catastrophe can also lead to the emergence of spontaneous polarization. We report that thin films of originally nonpolar LaFeO_{3} grown on SrTiO_{3} are converted to polar as a consequence of the polar catastrophe. The induced spontaneous polarization evokes photovoltaic properties distinct from conventional p-n junctions, such as a switching of the photocurrent direction by changing the interfacial atomic sequence. The control of the bulk polarization by engineering the interface demonstrated here will expand the possibilities for designing and realizing new polar materials with photovoltaic functions.