Large-scale cranial window for in vivo mouse brain imaging utilizing fluoropolymer nanosheet and light-curable resin

Two-photon microscopy enables in vivo imaging of neuronal activity in mammalian brains at high resolution. However, two-photon imaging tools for stable, long-term, and simultaneous study of multiple brain regions in same mice are lacking. Here, we propose a method to create large cranial windows covering such as the whole parietal cortex and cerebellum in mice using fluoropolymer nanosheets covered with light-curable resin (termed the 'Nanosheet Incorporated into light-curable REsin' or NIRE method). NIRE method can produce cranial windows conforming the curved cortical and cerebellar surfaces, without motion artifacts in awake mice, and maintain transparency for >5 months. In addition, we demonstrate that NIRE method can be used for in vivo two-photon imaging of neuronal ensembles, individual neurons and subcellular structures such as dendritic spines. The NIRE method can facilitate in vivo large-scale analysis of heretofore inaccessible neural processes, such as the neuroplastic changes associated with maturation, learning and neural pathogenesis.

Photoluminescent Layered Crystal Consisting of Anderson-Type Polyoxometalate and Surfactant toward a Potential Inorganic-Organic Hybrid Laser

The hybridization of inorganic and organic components is a promising strategy to build functional materials. Among several functions, luminescence is an important function which should be considered for practical usage. Inorganic-organic hybrid luminescent materials have been investigated as phosphors, sensors, and lasers. Organic luminescent centers such as dye molecules have often been hybridized with inorganic matrices. Polyoxometalate anions (POMs) are effective inorganic luminescent centers due to their luminescent properties and structural designability. However, most luminescent POM components are limited to lanthanide-based POMs. In this report, a photoluminescent inorganic-organic hybrid crystal based on a non-lanthanide POM was successfully synthesized as a single crystal. Anderson-type hexamolybdochromate ([CrMo6O18(OH)6]3-, CrMo6) anion exhibiting emission derived from Cr3+ was utilized with n-dodecylammonium ([C12H25NH3]+, C12NH3) surfactant cation to obtain a photoluminescent hybrid crystal. The grown single crystal of C12NH3-CrMo6 comprised a distinct layered structure consisting of inorganic CrMo6 layers and interdigitated C12NH3 layers. In the CrMo6 layers, the CrMo6 anions were associated with water molecules by hydrogen bonding to form a densely packed two-dimensional network. Steady-state and time-resolved photoluminescence spectroscopy revealed that the C12NH3-CrMo6 hybrid crystal exhibited characteristic emission from the CrMo6 anion. Preliminary lasing properties were also observed for C12NH3-CrMo6, which shows the possibility of using the C12NH3-CrMo6 hybrid crystal as an inorganic-organic hybrid laser.

Nanosheet coating improves stability of human pluripotent stem cell culture on glass substrates

High-resolution imaging analysis using various types of cells is an essential tool for dissecting cell functions. Generally, obtaining such images requires the cells to be cultured on glass substrates; however, it often results in the unstable status of cells. In this study, we report that coating the glass substrate using nanosheet composed of hydrophobic polystyrene, with Matrigel, significantly improves the viability of human pluripotent stem cells (hPSCs). Moreover, the nanosheet coating does not affect the transcriptome status of hPSC and enables researchers to perform the high-resolution imaging assay. These results indicate that the nanosheet coating is beneficial to the cells vulnerable to glass substrate culture. Using the nanosheet coating, we revealed that the spreading status of lnc RNA XIST, essential for X-chromosome inactivation (XCI) in female cells, in the nuclei significantly differs in each hPSC line. Taken together, our study provides a novel method to investigate biological questions using high-resolution imaging techniques.

An Inorganic-Organic Hybrid Framework Composed of Polyoxotungstate and Long-Chained Bolaamphiphile

Surfactants are functional molecules utilized in various situations. The self-assembling property of surfactants enables several molecular arrangements that can be employed to build up nanometer-sized architectures. This is beneficial in the construction of functional inorganic-organic hybrids holding the merits of both inorganic and organic components. Among several surfactants, bolaamphiphile surfactants with two hydrophilic heads are effective, as they have multiple connecting or coordinating sites in one molecule. Here, a functional polyoxotungstate inorganic anion was successfully hybridized with a bolaamphiphile to form single crystals with anisotropic one-dimensional alignment of polyoxotungstate. Keggin-type metatungstate ([H₂W₁₂O₄₀]^6-, H₂W₁₂) was employed as an inorganic anion, and 1,12-dodecamethylenediammonium (C₁₂N₂) derived from 1,12-dodecanediamine was combined as an organic counterpart. A simple and general ion-exchange reaction provided a hybrid crystal consisting of H₂W₁₂ and C₁₂N₂ (C₁₂N₂-H₂W₁₂). Single crystal X-ray structure analyses revealed a characteristic honeycomb structure in the C₁₂N₂-H₂W₁₂ hybrid crystal, which is possibly effective for the emergence of conductivity due to the dissociative protons of C₁₂N₂.

Biodegradable Polymer Nanosheets Incorporated with Zn-Containing Nanoparticles for Biomedical Applications

So far, poly(L-lactic acid), PLLA nanosheets proved to be promising for wound healing. Such biodegradable materials are easy to prepare, bio-friendly, cost-effective, simple to apply and were shown to protect burn wounds and facilitate their healing. At the same time, certain metal ions are known to be essential for wound healing, which is why this study was motivated by the idea of incorporating PLLA nanosheets with Zn²⁺ ion containing nanoparticles. Upon being applied on wound, such polymer nanosheets should release Zn²⁺ ions, which is expected to improve wound healing. The work thus focused on preparing PLLA nanosheets embedded with several kinds of Zn-containing nanoparticles, their characterization and ion-release behavior. ZnCl₂ and ZnO nanoparticles were chosen because of their different solubility in water, with the intention to see the dynamics of their Zn²⁺ ion release in liquid medium with pH around 7.4. Interestingly, the prepared PLLA nanosheets demonstrated quit similar ion release rates, reaching the maximum concentration after about 10 h. This finding implies that such polymer materials can be promising as they are expected to release ions within several hours after their application on skin.

The World Organisation for Animal Health - current and potential roles in safe international trade of bees and other insects

The World Organisation for Animal Health (WOAH, founded as OIE) is the recognised intergovernmental standard-setting organisation for animal health and welfare. The WOAH mandate is to support its members in the prevention of the spread of animal diseases of concern, as listed in the Terrestrial Animal Health Code (Terrestrial Code). Once a disease, infection or infestation is listed, national Veterinary Authorities have the obligation regularly to notify WOAH of the presence or absence of the listed disease. In regard to insects, the scope of the Terrestrial Code limits its recommendations to preserving the health of bees (species of the genus Apis, extended to the genus Bombus and to the stingless bees for one disease). However, it does not include standards to mitigate the potential animal health risks associated with the international trade of other insects. A description of the standard-setting process and a review of the history of the standards for bee health highlight the resources and requirements to expand the scope of the Terrestrial Code to include recommendations for animal health risk mitigation measures for the safety of international trade in insects. Any initiative to develop guidance on insect trade should include WOAH in its role as the sole global standard-setting organisation on animal health and welfare matters. This aligns with the WOAH commitment to a One Health approach.

Potential UV-Protective Effect of Freestanding Biodegradable Nanosheet-Based Sunscreen Preparations in XPA-Deficient Mice

Xeroderma pigmentosum (XP) is a rare autosomal recessive hereditary disorder. As patients with XP are deficient in nucleotide excision repair, they show severe photosensitivity symptoms. Although skin protection from ultraviolet (UV) radiation is essential to improve the life expectancy of such patients, the optimal protective effect is not achieved even with sunscreen application, owing to the low usability of the preparations. Nanosheets are two-dimensional nanostructures with a thickness in the nanometer range. The extremely large aspect ratios of the nanosheets result in high transparency, flexibility, and adhesiveness. Moreover, their high moisture permeability enables their application to any area of the skin for a long time. We fabricated preparations containing avobenzone (BMDBM) based on freestanding poly (L-lactic acid) (PLLA) nanosheets through a spin-coating process. Although monolayered PLLA nanosheets did not contain enough BMDBM to protect against UV radiation, the layered nanosheets, consisting of five discrete BMDBM nanosheets, showed high UV absorbance without lowering the adhesive strength against skin. Inflammatory reactions in XPA-deficient mice after UV radiation were completely suppressed by the application of BMDBM-layered nanosheets to the skin. Thus, the BMDBM layered nanosheet could serve as a potential sunscreen preparation to improve the quality of life of patients with XP.

Major hepatectomy with combined vascular resection for perihilar cholangiocarcinoma

Background

Hepatectomy with vascular resection (VR) for perihilar cholangiocarcinoma (PHCC) is a challenging procedure. However, only a few reports on this procedure have been published and its clinical significance has not been fully evaluated.

Methods

Patients undergoing surgical resection for PHCC from 2002–2017 were studied. The surgical outcomes of VR and non-VR groups were compared.

Results

Some 238 patients were included. VR was performed in 85 patients. The resected vessels were hepatic artery alone (31 patients), portal vein alone (37 patients) or both (17 patients). The morbidity rates were almost the same in the VR (49.4 per cent) and non-VR (43.8 per cent) groups (P = 0.404). The mortality rates of VR (3.5 per cent) and non-VR (3.3 per cent) were also comparable (P > 0.999). The median survival time (MST) was 45 months in the non-VR group and 36 months in VR group (P = 0.124). Among patients in whom tumour involvement was suspected on preoperative imaging and whose carbohydrate antigen 19-9 (CA19-9) value was 37 U/ml or less, MST in the VR group was significantly longer than that in the non-VR group (50 versus 34 months, P = 0.017). In contrast, when the CA19-9 value was greater than 37 U/ml, MST of the VR and non-VR groups was comparable (28 versus 29 months, P = 0.520).

Conclusion

Hepatectomy with VR for PHCC can be performed in a highly specialized hepatobiliary centre with equivalent short- and long-term outcomes to hepatectomy without VR.

External administration of moon jellyfish collagen solution accelerates physiological wound healing and improves delayed wound closure in diabetic model mice

Introduction

Artificial dermis is an effective therapeutic method for full-thickness dermal defects. However, the currently available artificial dermis made of porcine or bovine type I collagen has several limitations such as incomplete epithelialization and delayed migration of fibrogenic and angiogenic cells into the graft. We previously developed a composite dermal graft containing a mixture of moon jellyfish collagen and porcine type I collagen, and reported its stimulatory effect on both the re-epithelialization of the epidermis and the migration of fibrogenic and angiogenic cells into the graft. In the present study, we examined whether the same effect was observed by administering jellyfish collagen solution externally onto an artificial dermal graft made of bovine type I collagen.

Methods

We used a 6 mm full-thickness wound defect model. Moon jellyfish collagen was prepared as a concentrated 0.5% solution and dripped externally onto a transplanted artificial dermal graft made of bovine type I collagen. Wound repair and long-term dermal tissue remodeling were compared between mice administered jellyfish collagen solution on the bovine collagen graft and those transplanted with a composite dermal graft containing the same amounts of jellyfish and bovine collagens. The stimulatory effect of jellyfish collagen solution was also evaluated using diabetic dB/dB mice.

Results

External administration of jellyfish collagen solution onto the bovine collagen graft significantly accelerated wound closure compared to control saline. It also decreased the number of inflammatory cells infiltrating the wound and suppressed absorption of the transplanted graft, as well as reduced subsequent scar formation. Furthermore, external administration of jellyfish collagen solution onto the bovine collagen graft improved the delayed wound healing in diabetic model mice, and this effect was superior to that of the currently used basic fibroblast growth factor.

Conclusions

External administration of moon jellyfish collagen solution onto a bovine collagen graft significantly accelerated physiological wound healing and prevented excessive scar formation. It also improved wound closure in diabetic model mice, confirming its therapeutic application for intractable skin ulcers caused by impaired wound healing.

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Impaired wound healing is frequently observed in elderly and diabetic patients.

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Moon jellyfish collagen accelerates wound closure after full-thickness dermal defect in mice.

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Jellyfish collagen used as an external medicine stimulates the elongation of regenerating epithelial cells.

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Externally applied jellyfish collagen improves wound healing in diabetic model mice.

Protocol for constructing an extensive cranial window utilizing a PEO-CYTOP nanosheet for in vivo wide-field imaging of the mouse brain

Large-scale optical measurements have revealed the anatomical and functional connectivity among brain regions underlying brain functions. Here, we describe how to construct a cranial window utilizing a polyethylene-oxide-coated CYTOP (PEO-CYTOP) nanosheet that suppresses bleeding on the brain surface of mice. We demonstrate in vivo two-photon imaging through the PEO-CYTOP nanosheet at the subcellular resolution in the parietal region of the mouse brain. This protocol improves the surgical procedure and expands the optically observable regions, thereby promoting understanding of brain function.

For complete details on the use and execution of this protocol, please refer to Takahashi et al. (2020).

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Detailed protocol for constructing a vast cranial window for in vivo mouse brain imaging

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Preparation and brain-sealing method of PEO-CYTOP nanosheet

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Instruction to make a large cranial hole with a depressant for intracranial pressure

Utility of remnant liver volume for predicting posthepatectomy liver failure after hepatectomy with extrahepatic bile duct resection

BACKGROUND

Hepatectomy with extrahepatic bile duct resection is associated with a high risk of posthepatectomy liver failure (PHLF). However, the utility of the remnant liver volume (RLV) in cholangiocarcinoma has not been studied intensively.

METHODS

Patients who underwent major hepatectomy with extrahepatic bile duct resection between 2002 and 2018 were reviewed. The RLV was divided by body surface area (BSA) to normalize individual physical differences. Risk factors for clinically relevant PHLF were evaluated with special reference to the RLV/BSA.

RESULTS

A total of 289 patients were included. The optimal cut-off value for RLV/BSA was determined to be 300 ml/m2. Thirty-two patients (11.1 per cent) developed PHLF. PHLF was more frequent in patients with an RLV/BSA below 300 ml/m2 than in those with a value of 300 ml/m2 or greater: 19 of 87 (22 per cent) versus 13 of 202 (6.4 per cent) (P < 0.001). In multivariable analysis, RLV/BSA below 300 ml/m2 (P = 0.013), future liver remnant plasma clearance rate of indocyanine green less than 0.075 (P = 0.031), and serum albumin level below 3.5 g/dl (P = 0.015) were identified as independent risk factors for PHLF. Based on these risk factors, patients were classified into three subgroups with low (no factors), moderate (1-2 factors), and high (3 factors) risk of PHLF, with PHLF rates of 1.8, 14.8 and 63 per cent respectively (P < 0.001).

CONCLUSION

An RLV/BSA of 300 ml/m2 is a simple predictor of PHLF in patients undergoing hepatectomy with extrahepatic bile duct resection.

PEO-CYTOP Fluoropolymer Nanosheets as a Novel Open-Skull Window for Imaging of the Living Mouse Brain

In vivo two-photon deep imaging with a broad field of view has revealed functional connectivity among brain regions. Here, we developed a novel observation method that utilizes a polyethylene-oxide-coated CYTOP (PEO-CYTOP) nanosheet with a thickness of ∼130 nm that exhibited a water retention effect and a hydrophilized adhesive surface. PEO-CYTOP nanosheets firmly adhered to brain surfaces, which suppressed bleeding from superficial veins. By taking advantage of the excellent optical properties of PEO-CYTOP nanosheets, we performed in vivo deep imaging in mouse brains at high resolution. Moreover, PEO-CYTOP nanosheets enabled to prepare large cranial windows, achieving in vivo imaging of neural structure and Ca²⁺ elevation in a large field of view. Furthermore, the PEO-CYTOP nanosheets functioned as a sealing material, even after the removal of the dura. These results indicate that this method would be suitable for the investigation of neural functions that are composed of interactions among multiple regions.

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PEO-CYTOP nanosheet enables in vivo deep brain imaging in a vast field of view

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The 130 nm thickness and the hydrophilized surface realize the strong adhesiveness

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Suppressions of bleeding from the surface and inflammation in long-term are achieved

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The vast and transparent cranial window with natural curvature of the surface

Giant magneto-optical responses in magnetic Weyl semimetal Co3Sn2S2

The Weyl semimetal (WSM), which hosts pairs of Weyl points and accompanying Berry curvature in momentum space near Fermi level, is expected to exhibit novel electromagnetic phenomena. Although the large optical/electronic responses such as nonlinear optical effects and intrinsic anomalous Hall effect (AHE) have recently been demonstrated indeed, the conclusive evidence for their topological origins has remained elusive. Here, we report the gigantic magneto-optical (MO) response arising from the topological electronic structure with intense Berry curvature in magnetic WSM Co₃Sn₂S₂. The low-energy MO spectroscopy and the first-principles calculation reveal that the interband transitions on the nodal rings connected to the Weyl points show the resonance of the optical Hall conductivity and give rise to the giant intrinsic AHE in dc limit. The terahertz Faraday and infrared Kerr rotations are found to be remarkably enhanced by these resonances with topological electronic structures, demonstrating the novel low-energy optical response inherent to the magnetic WSM.

A Novel Composite Biomaterial Made of Jellyfish and Porcine Collagens Accelerates Dermal Wound Healing by Enhancing Reepithelization and Granulation Tissue Formation in Mice

Background and Objective: Impaired dermal wound healing represents a major medical issue in today's aging populations. Granulation tissue formation in the dermis and reepithelization of the epidermis are both important and necessary for proper wound healing. Although a number of artificial dermal grafts have been used to treat full-thickness dermal loss in humans, they do not induce reepithelization of the wound, requiring subsequent epithelial transplantation. In the present study, we sought a novel biomaterial that accelerates the wound healing process. Approach: We prepared a composite biomaterial made of jellyfish and porcine collagens and developed a hybrid-type dermal graft that composed of the upper layer film and the lower layer sponge made of this composite biomaterial. Its effect on dermal wound healing was examined using a full-thickness excisional wound model. Structural properties of the dermal graft and histological features of the regenerating skin tissue were characterized by electron microscopic observation and immunohistological examination, respectively. Results: The composite biomaterial film stimulated migration of keratinocytes, leading to prompt reepithelization. The regenerating epithelium consisted of two distinct cell populations: keratin 5-positive basal keratinocytes and more differentiated cells expressing tight junction proteins such as claudin-1 and occludin. At the same time, the sponge made of the composite biomaterial possessed a significantly enlarged intrinsic space and enhanced infiltration of inflammatory cells and fibroblasts, accelerating granulation tissue formation. Innovation: This newly developed composite biomaterial may serve as a dermal graft that accelerates wound healing in various pathological conditions. Conclusion: We have developed a novel dermal graft composed of jellyfish and porcine collagens that remarkably accelerates the wound healing process.

Efficient differentiation and polarization of primary cultured neurons on poly(lactic acid) scaffolds with microgrooved structures

Synthetic biodegradable polymers including poly(lactic acid) (PLA) are attractive cell culture substrates because their surfaces can be micropatterned to support cell adhesion. The cell adhesion properties of a scaffold mainly depend on its surface chemical and structural features; however, it remains unclear how these characteristics affect the growth and differentiation of cultured cells or their gene expression. In this study, we fabricated two differently structured PLA nanosheets: flat and microgrooved. We assessed the growth and differentiation of mouse primary cultured cortical neurons on these two types of nanosheets after pre-coating with poly-D-lysine and vitronectin. Interestingly, prominent neurite bundles were formed along the grooves on the microgrooved nanosheets, whereas thin and randomly extended neurites were only observed on the flat nanosheets. Comparative RNA sequencing analyses revealed that the expression of genes related to postsynaptic density, dendritic shafts, and asymmetric synapses was significantly and consistently up-regulated in cells cultured on the microgrooved nanosheets when compared with those cultured on the flat nanosheets. These results indicate that microgrooved PLA nanosheets can provide a powerful means of establishing a culture system for the efficient and reproducible differentiation of neurons, which will facilitate future investigations of the molecular mechanisms underlying the pathogenesis of neurological disorders.

Porous nanosheet wrapping for live imaging of suspension cells

In the field of cell imaging, it is still a practical challenge to obtain the high quality live imaging of suspension cells, mainly due to undesirable cell movement in the imaging field during observation. This study describes a porous nanosheet wrapping method to noninvasively immobilize suspension cells for their live imaging. Perforated nanopores are fabricated on a nanosheet to enable the addition of external chemicals to cells, ranging from small molecules to macromolecules. Through several case studies, such as the live imaging of membrane staining of liposomes, transferrin endocytosis of B cells, and activation of platelets, it is verified that the confined space made by the nanosheet could provide a hydrodynamically stable environment for suspension cells, even if an aqueous stimulus is added through the nanopores in a static or a flowing condition. With this method, the live imaging of the whole activation process on a specific suspension cell in the imaging field is achieved, which is not feasible with the existing cell immobilization methods. This study suggests that the method of porous nanosheet wrapping will facilitate the visualization of the dynamic functions of suspension cells.

Propagation dynamics of spin excitations along skyrmion strings

Magnetic skyrmions, topological solitons characterized by a two-dimensional swirling spin texture, have recently attracted attention as stable particle-like objects. In a three-dimensional system, a skyrmion can extend in the third dimension forming a robust and flexible string structure, whose unique topology and symmetry are anticipated to host nontrivial functional responses. Here we experimentally demonstrate the coherent propagation of spin excitations along skyrmion strings for the chiral-lattice magnet Cu₂OSeO₃. We find that this propagation is directionally non-reciprocal and the degree of non-reciprocity, as well as group velocity and decay length, are strongly dependent on the character of the excitation modes. These spin excitations can propagate over a distance exceeding 50 μm, demonstrating the excellent long-range ordered nature of the skyrmion-string structure. Our combined experimental and theoretical analyses offer a comprehensive account of the propagation dynamics of skyrmion-string excitations and suggest the possibility of unidirectional information transfer along such topologically protected strings.

Nanosheet wrapping-assisted coverslip-free imaging for looking deeper into a tissue at high resolution

In order to achieve deep tissue imaging, a number of optical clearing agents have been developed. However, in a conventional microscopy setup, an objective lens can only be moved until it is in contact with a coverslip, which restricts the maximum focusing depth into a cleared tissue specimen. Until now, it is still a fact that the working distance of a high magnification objective lens with a high numerical aperture is always about 100 μm. In this study, a polymer thin film (also called as nanosheet) composed of fluoropolymer with a thickness of 130 nm, less than one-thousandth that of a 170 μm thick coverslip, is employed to replace the coverslip. Owing to its excellent characteristics, such as high optical transparency, mechanical robustness, chemical resistance, and water retention ability, nanosheet is uniquely capable of providing a coverslip-free imaging. By wrapping the tissue specimen with a nanosheet, an extra distance of 170 μm for the movement of objective lens is obtained. Results show an equivalently high resolution imaging can be obtained if a homogenous refractive index between immersion liquid and mounting media is adjusted. This method will facilitate a variety of imaging tasks with off-the-shelf high magnification objectives.

P175 Prognostic value of 99mTc-ECD brain perfusion SPECT in patients with atrial fibrillation and dementia

Background

Atrial fibrillation (AF) is the most common cardiac arrhythmia, and those afflicted have reduced quality of life, functional status, and cardiac performance. The patients with AF have a high risk of coronary heart disease and cardiovascular disease. Although the prevalence of AF is increasing, cognitive disorders are also on the rise in tandem with the aging of the population. The patients with dementia have also experienced lower the quality of life and have increased mortality. Technetium 99m ECD brain perfusion single photon emission computed tomography (99mTc-ECD brain perfusion SPECT) is a useful modality for diagnosing dementia and identifying high risk patients with mild cognitive impairment. However, there are few reports about the relationship between the value of Z score calculated by 99mTc-ECD brain perfusion SPECT and prognosis of patients with AF and dementia.

Purpose

The aim of this study was to evaluate the prognostic values of brain perfusion using 99mTc-ECD SPECT in patients with AF and dementia.

Methods

Among 405 consecutive patients who were diagnosed as AF in cardiac outpatients and subsequently diagnosed as dementia using Mini-Mental State Examination by neurologists or psychiatrists, we identified 170 patients (81 ± 10 years) who underwent 99mTc-ECD brain perfusion SPECT for the current study. Of those, 73, 73, and 24 were diagnosed as Alzheimer’s dementia (AD), vascular dementia (VD), and non-specified dementia respectively. Multivariate Cox model was used to assess if higher Z score by 99mTc-ECD brain perfusion SPECT and clinical parameters were associated with major adverse cardiovascular events (MACE) including cardiac death, myocardial infarction, hospitalization for heart failure, and stroke. Sub-analyses of multivariate Cox models by AD or VD were also assessed. The cut-off values of Z score were determined using area under the curve by a receiver operating characteristic analysis based on MACE occurrences.

Results

During a mean follow-up of 1258 ± 1044 days, 62 MACE occurred. There was not significant difference of MACE between AD and VD (33%, vs. 44%, p = 0.153). By multivariable Cox model, the higher Z score of temporal-occipital-pariental lobe was associated with increased MACE compared to the lower group (HR 2.521, 95% CI 1.465–4.337, p &lt; 0.001). In a sub-analysis of patients with AD, Z score was the most significant prognostic factor for MACE (HR 3.969, 95% CI 1.374–11.468, p = 0.011). The similar trend was observed in those with VD (HR 2.247, 95% CI 1.028–4.913, p = 0.043). Conclusion: This study demonstrated that the Z score of temporal-occipital-pariental lobe by 99mTc-ECD brain perfusion SPECT could be a potential prognostic value among patients with AF and dementia, regardless of type of dementia.

Prognostic role of the length of tumour-vein contact at the portal-superior mesenteric vein in patients having surgery for pancreatic cancer

BACKGROUND

The length of tumour-vein contact between the portal-superior mesenteric vein (PV/SMV) and pancreatic head cancer, and its relationship to prognosis in patients undergoing pancreatic surgery, remains controversial.

METHODS

Patients diagnosed with pancreatic head cancer who were eligible for pancreatoduodenectomy between October 2002 and December 2016 were analysed. The PV/SMV contact was assessed retrospectively on CT. Using the minimum P value approach based on overall survival after surgery, the optimal cut-off value for tumour-vein contact length was identified.

RESULTS

Among 491 patients included, 462 underwent pancreatoduodenectomy for pancreatic head cancer. PV/SMV contact with the tumour was detected on preoperative CT in 248 patients (53·7 per cent). Overall survival of patients with PV/SMV contact exceeding 20 mm was significantly worse than that of patients with a contact length of 20 mm or less (median survival time (MST) 23·3 versus 39·3 months; P = 0·012). Multivariable analysis identified PV/SMV contact longer than 20 mm as an independent predictor of poor survival, whereas PV/SMV contact greater than 180° was not a predictive factor. Among patients with a PV/SMV contact length exceeding 20 mm on pretreatment CT, those receiving neoadjuvant therapy had significantly better overall survival than patients who had upfront surgery (MST not reached versus 21·6 months; P = 0·002).

CONCLUSION

The length of PV/SMV contact predicts survival, and may be used to suggest a role for neoadjuvant therapy to improve prognosis.

The tumor diameter cut-off for predicting microscopic intrahepatic metastasis of hepatocellular carcinoma patients without treatment history differs from that of hepatocellular carcinoma patients with a treatment history

BACKGROUND AND AIM

Intrahepatic metastasis (IM) of hepatocellular carcinoma (HCC) occurs via vascular invasion; the tumor diameter that affects the risk of micro intra-hepatic metastasis (MIM) should be larger than that which affects the risk of micro vessel invasion (MVI). The aim of the present study was to determine the optimum tumor diameter cut-off value for predicting the presence of MIM in HCC patients without treatment history and HCC patients with a treatment history and to compare these diameters between cases of MVI and MIM.

METHODS

This retrospective study included 621 patients without macroscopic vessel invasion or intrahepatic metastasis on preoperative imaging who underwent hepatectomy. The cut-off tumor diameter for predicting the presence of MIM was determined by a receiver operating characteristic curves analysis.

RESULTS

The optimum cut-off value for predicting the presence of MIM in HCC patients without treatment history was 43 mm. In contrast, the optimum cut-off value for predicting the presence of MIM in HCC patients with a treatment history was 20 mm. Among 46 HCC patients with MIM without treatment history, there were 20 patients with MIM without MVI who were considered to have potential multi-centric (MC) tumors rather than IM. The cumulative overall survival rates in patients with MIM without MVI (potential MC) was significantly better than that in patients with both MIM and MVI (P = 0.022).

CONCLUSIONS

The tumor diameter cut-off value for predicting MIM differed between HCC patients without treatment history and with a treatment history and slightly smaller than those for predicting MVI beyond our expectation.

Microwave Directional Dichroism Resonant with Spin Excitations in the Polar Ferromagnet GaV_{4}S_{8}

We have investigated the directional dichroism of magnetic resonance spectra in the polar ferromagnet GaV_{4}S_{8}. While four types of structural domains are energetically degenerated under a zero field, the magnetic resonance for each domain is well separated by applying magnetic fields due to uniaxial magnetic anisotropy. Consequently, a directional dichroism as large as 20% is clearly observed without domain cancellation. The present observation therefore demonstrates that not only magnetoelectric monodomain crystals but also magnetoelectric multidomain specimens can be used to realize microwave (optical) diodes owing to the lack of inversion domains.

Controlled introduction of metal cations into polymerizable ionic liquid-polyoxomolybdate hybrid crystals

The first syntheses of polyoxomolybdate hybrid crystals were achieved by using polymerizable ionic-liquid.

Propensity score-matched comparison of non-anatomical resection and radiofrequency ablation for hepatocellular carcinoma in patients with up to three tumours, each measuring up to 3 cm in diameter

Background

Non‐anatomical liver resection (NAR) and radiofrequency ablation (RFA) are treatment options for early‐stage hepatocellular carcinoma (HCC). The aim was to compare the outcomes of NAR and RFA for HCC in patients with three or fewer tumour nodules, each measuring not more than 3 cm in maximum diameter.

Methods

Eligible patients undergoing NAR or RFA with curative intent between September 2002 and December 2014 were identified. A propensity score‐matching analysis was performed to reduce bias, and outcomes in these patients were analysed.

Results

From a total of 199 patients, 1:1 propensity score matching identified 70 matched pairs. Patients having NAR had a longer hospital stay (median 10 days versus 4 days for those who had RFA; P < 0·001) and a higher morbidity rate (24 versus 10 per cent respectively; P = 0·042). Patients who had NAR had slightly better recurrence‐free survival but this failed to reach statistical significance in univariable analysis (P = 0·064). There was no significant difference in overall survival between the two groups (P = 0·475). RFA was identified as an independent risk factor for recurrence‐free survival (hazard ratio (HR) 1·57; P = 0·041) in multivariable analysis. Local recurrence was significantly more common in patients receiving RFA (23 versus 1 per cent; P < 0·001).

Conclusion

RFA was an independent risk factor for shorter recurrence‐free survival, with a significantly higher local recurrence rate than NAR. Despite these differences, overall survival was not affected.

Elongated phase separation domains in spin-cast polymer blend thin films characterized using a panoramic image

Polymer thin films with micro/nano-structures can be prepared by a solvent evaporation induced phase separation process via spin-casting a polymer blend, where the elongated phase separation domains are always inevitable. The striation defect, as a thickness nonunifomity in spin-cast films, is generally coexistent with the elongated domains. Herein, the morphologies of polymer blend thin films are recorded from the spin-cast center to the edge in a panoramic view. The elongated domains are inclined to appear at the ridge regions of striations with increasing radial distance and align radially, exhibiting a coupling between the phase separation morphology and the striation defect that may exist. We demonstrate that the formation of elongated domains is not attributed to shape deformation, but is accomplished in situ. A possible model to describe the initiation and evolution of the polymer blend phase separation morphology during spin-casting is proposed.

Treatment of cervical pregnancy with ultrasound-guided local methotrexate injection

OBJECTIVES

Cervical pregnancy (CP) is a rare type of ectopic pregnancy. While methotrexate (MTX) is generally the first-line method of choice for clinically stable women, there is still no consensus on the most appropriate treatment for this abnormal pregnancy. The aim of this study was to investigate the efficacy of a single local MTX injection under transvaginal ultrasound guidance for the initial treatment of CP and to assess post-treatment fertility.

METHODS

We reviewed retrospectively 15 patients with CP treated with local MTX injection under transvaginal ultrasound guidance. In all patients, the serum human chorionic gonadotropin (hCG) levels were monitored and the gestational sac was evaluated using ultrasonography after treatment. Magnetic resonance imaging (MRI) was performed as necessary. We evaluated the patients' clinical characteristics and clinical course after treatment, the efficacy of the treatment and the post-treatment fertility in patients desiring subsequent pregnancy.

RESULTS

The median estimated gestational age at the time of MTX injection was 6 + 2 (range, 5 + 2 to 11 + 0) weeks. All 15 patients were treated successfully, without the need for blood transfusion or surgical procedures; however, three patients required an additional local MTX injection due to a poor decline in serum hCG level following the initial injection, while one patient required uterine artery embolization due to persistent vaginal bleeding and an enlarging gestational sac with blood vessels visible on contrast-enhanced MRI. The mean time following initial MTX injection for hCG normalization was 43.8 (95% CI, 33.3-54.3) days and for resumption of menses was 68.4 (95% CI, 51.9-84.9) days. Seven of the 10 women desiring subsequent pregnancy following treatment had uneventful pregnancy, one became pregnant but miscarried spontaneously at 8 weeks of gestation, one was treated by laparoscopic surgery after diagnosis of a tubal pregnancy and one did not conceive.

CONCLUSIONS

A single, ultrasound-guided, local MTX injection is apparently effective for the treatment of CP without the need for concomitant procedures or surgical intervention. Furthermore, this conservative technique both preserves fertility and allows for the possibility of subsequent uneventful pregnancy. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Fluoropolymer Nanosheet as a Wrapping Mount for High-Quality Tissue Imaging

In the field of biological microscopy technology, it is still a practical challenge to obtain high-quality tissue images, due to the tissue desiccation that occurs during observations without an effective sample mounting. Inspired by the use of plastic food wrap, this study proposes the use of polymer thin films (also known as nanosheets) to fix the tissue samples. Water-repellent nanosheets composed of the amorphous fluoropolymer CYTOP are prepared with adjustable thicknesses and their hydrophobicity, transparency, and adhesion strength are evaluated. They show excellent water-retention effect and work well for sample fixation. By wrapping cleared mouse brain slices with a 133 nm thick CYTOP nanosheet, this study achieves high spatial resolution neuron images while scanning over a large area for a long period of time. No visible artifacts arising from sample shrinkage can be detected. This study also expects that nanosheet wrapping could be effective over a longer time span by combination with conventional agarose embedding.

Sandwich-type PLLA-nanosheets loaded with BMP-2 induce bone regeneration in critical-sized mouse calvarial defects

To overcome serious clinical problems caused by large bone defects, various approaches to bone regeneration have been researched, including tissue engineering, biomaterials, stem cells and drug screening. Previously, we developed a free-standing biodegradable polymer nanosheet composed of poly(L-lactic acid) (PLLA) using a simple fabrication process consisting of spin-coating and peeling techniques. Here, we loaded recombinant human bone morphogenetic protein-2 (rhBMP-2) between two 60-nm-thick PLLA nanosheets, and investigated these sandwich-type nanosheets in bone regeneration applications. The PLLA nanosheets displayed constant and sustained release of the loaded rhBMP-2 for over 2months in vitro. Moreover, we implanted the sandwich-type nanosheets with or without rhBMP-2 into critical-sized defects in mouse calvariae. Bone regeneration was evident 4weeks after implantation, and the size and robustness of the regenerated bone had increased by 8weeks after implantation in mice implanted with the rhBMP-2-loaded nanosheets, whereas no significant bone formation occurred over a period of 20weeks in mice implanted with blank nanosheets. The PLLA nanosheets loaded with rhBMP-2 may be useful in bone regenerative medicine; furthermore, the sandwich-type PLLA nanosheet structure may potentially be applied as a potent prolonged sustained-release carrier of other molecules or drugs.

STATEMENTS OF SIGNIFICANCE

Here we describe sandwich-type poly(L-lactic acid) (PLLA) nanosheets loaded with recombinant human bone morphogenetic protein-2 (rhBMP-2) as a novel method for bone regeneration. Biodegradable 60-nm-thick PLLA nanosheets display strong adhesion without any adhesive agent. The sandwich-type PLLA nanosheets displayed constant and sustained release of the loaded rhBMP-2 for over 2months in vitro. The nanosheets with rhBMP-2 markedly enhanced bone regeneration when they were implanted into critical-sized defects in mouse calvariae. In addition to their application for bone regeneration, PLLA nanosheets may be useful for various purposes in combination with various drugs or molecules, because they displays excellent capacity as a sustained-release carrier.

Impact of Patient Age on the Postoperative Survival in Pancreatic Head Cancer

BACKGROUND

Some reports have stated that pancreatoduodenectomy for elderly patients have comparable morbidity and mortality to that of young patients. However, the long-term outcomes of these patients have not been fully evaluated, especially for pancreatic head cancer.

METHODS

A total of 227 patients who underwent pancreatoduodenectomy for pancreatic head cancer between 2007 and 2014 were included. They were stratified according to age: young (<70 years), elderly (70 to <80 years), and very elderly (≥80 years). The short- and long-term outcomes were evaluated.

RESULTS

There were no significant differences in terms of morbidity among the three groups. The median disease-free survival times were 15 months in the young, 11 months in the elderly, and 7 months in the very elderly. The disease-free survival of the young patients was significantly better than that in both the elderly and the very elderly (p = 0.012 and p = 0.016). The median overall survival times were 30 months in the young, 20 months in the elderly, and 14 months in the very elderly. The overall survival of the young patients was significantly better than that in both the elderly and the very elderly (p = 0.007 and p < 0.001). The difference was marginal between the elderly and the very elderly (p = 0.053). Multivariate analysis revealed that lymph node metastasis (p < 0.001), age ≥80 years (p = 0.013), lack of adjuvant chemotherapy (p = 0.003), blood transfusion (p = 0.015), and CA 19-9 ≥300 U/ml (p = 0.040) were significant prognostic factors.

CONCLUSIONS

Patient age influenced the survival after pancreatoduodenectomy for pancreatic cancer.

Impact of Subnormothermic Machine Perfusion Preservation in Severely Steatotic Rat Livers: A Detailed Assessment in an Isolated Setting

The current drastic shortage of donor organs has led to acceptance of extended-criteria donors for transplantation, despite higher risk of primary nonfunction. Here, we report the impact of subnormothermic machine perfusion (SMP) preservation on the protection of >50% macrosteatotic livers. Dietary hepatic steatosis was induced in Wistar rats via 2-day fasting and subsequent 3-day re-feeding with a fat-free, carbohydrate-rich diet. This protocol induces 50-60% macrovesicular steatosis, which should be discarded when preserved via cold storage (CS). The fatty livers were retrieved and preserved for 4 h using either CS in histidine-tryptophan-ketoglutarate or SMP in polysol solution. Graft functional integrity was evaluated via oxygenated ex vivo reperfusion for 2 h at 37°C. SMP resulted in significant reductions in not only parenchymal alanine aminotransferase (p < 0.001), but also mitochondrial glutamate dehydrogenase (p < 0.001) enzyme release. Moreover, portal venous pressure (p = 0.047), tissue adenosine triphosphate (p = 0.001), bile production (p < 0.001), high-mobility group box protein-1 (p < 0.001), lipid peroxidation, and tissue glutathione were all significantly improved by SMP. Electron microscopy revealed that SMP alleviated deleterious alterations of sinusoidal microvasculature and hepatocellular mitochondria, both of which are characteristic disadvantages associated with steatosis. SMP could protect 50-60% macrosteatotic livers from preservation/reperfusion injury, and may thus represent a new means for expanding available donor pools.

Massive Fabrication of Polymer Microdiscs by Phase Separation and Freestanding Process

We present a facile method to fabricate polymer thin films with tens of nanometers thickness and several micrometers size (also called "microdiscs" herein) by applying phase separation of polymer blend. A water-soluble supporting layer is employed to obtain a freestanding microdisc suspension. Owing to their miniaturized size, microdiscs can be injected through a syringe needle. Herein, poly(d,l-lactic acid) microdiscs were fabricated with various thicknesses and sizes, in the range from ca. 10 to 60 nm and from ca. 1.0 to 10.0 μm, respectively. Magnetic nanoparticles were deposited on polymer microdiscs with a surface coating method. The magnetic manipulation of microdiscs in a liquid environment under an external magnetic field was achieved with controllable velocity by adjusting the microdisc dimensions and the loading amount of magnetic components. Such biocompatible polymer microdiscs are expected to serve as injectable vehicles for targeted drug delivery.

Adhesive and robust multilayered poly(lactic acid) nanosheets for hemostatic dressing in liver injury model

Freestanding biodegradable nanosheets composed of poly(l-lactic acid) (PLLA) have been developed for various biomedical applications. These nanosheets exhibit unique properties such as high adhesiveness and exquisite flexibility; however, they burst easily due to their nanometer thickness. We herein describe a freestanding, multilayered nanosheet composed of PLLA fabricated using a simple combination procedure: (i) multilayering of PLLA and alginate, (ii) gelation of the alginate layers, (iii) fusion-cut sealing, and (iv) elution of the alginate layers. The multilayered nanosheets not only reinforced the bursting strength but also provided a high level of adhesive strength. In fact, they were found to show potential as a hemostatic dressing, and they tended to show reduced tissue adhesion that accompanies liver injury. Therefore, we propose this biomaterial as a candidate for an alternative to conventional therapy in hemorrhage. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1747-1757, 2017.

Neutrophil to lymphocyte ratio as an indicator of the malignant behaviour of hepatocellular carcinoma

Background

The preoperative serum neutrophil to lymphocyte ratio (NLR) has been associated with survival in patients with hepatocellular carcinoma (HCC). However, it is still unclear what the NLR reflects precisely. This study aimed to elucidate the relationship between the NLR and TNM stage, and the role of NLR as a prognostic factor after liver resection for HCC.

Methods

This retrospective study enrolled patients who underwent liver resection as initial treatment for HCC. The best cut-off value of serum NLR was determined, and overall survival was compared among patients grouped according to TNM stage (I, II and III).

Results

The best cut-off value for NLR was 2·8. A high preoperative NLR was more frequently associated with poor overall survival than a low preoperative NLR after resection for TNM stage I tumours (5-year survival 45·0 versus 76·4 per cent, P &lt; 0·001), but not stage II (P = 0·283) or stage III (P = 0·155) tumours. Among patients with TNM stage I disease, the proportion of patients with extrahepatic recurrence was greater in the group with a high preoperative NLR than in the low-NLR group (P = 0·006). In multivariable analysis, preoperative NLR was the strongest independent prognostic risk factor for overall survival in TNM stage I (hazard ratio 2·69, 95 per cent c.i. 1·57 to 4·59; P &lt; 0·001).

Conclusion

Preoperative NLR was an important prognostic factor for TNM stage I HCC after liver resection with curative intent. These results suggest that the NLR may reflect the malignant potential of HCC.

Surface modification on polydimethylsiloxane-based microchannels with fragmented poly(l-lactic acid) nanosheets

Surface modification is a critical issue in various applications of polydimethylsiloxane (PDMS)-based microfluidic devices. Here, we describe a novel method through which PDMS-based microchannels were successfully modified with fragmented poly(l-lactic acid) (PLLA) nanosheets through a simple patchwork technique that exploited the high level of adhesiveness of PLLA nanosheets. Compared with other surface modification methods, our method required neither complicated chemical modifications nor the use of organic solvents that tend to cause PDMS swelling. The experimental results indicated that the modified PDMS exhibited excellent capacity for preventing the adhesion and activation of platelets. This simple yet efficient method can be used to fabricate the special PDMS microfluidic devices for biological, medical, and even hematological purposes.

Impact of bacterial contamination of the abdominal cavity during pancreaticoduodenectomy on surgical-site infection

Background

Several risk factors for complications after pancreaticoduodenectomy have been reported. However, the impact of intraoperative bacterial contamination on surgical outcome after pancreaticoduodenectomy has not been examined in depth.

Methods

This retrospective study included patients who underwent pancreaticoduodenectomy and peritoneal lavage using 7000 ml saline between July 2012 and May 2014. The lavage fluid was subjected to bacterial culture examination. The influence of a positive bacterial culture on surgical-site infection (SSI) and postoperative course was evaluated. Risk factors for positive bacterial cultures were also evaluated.

Results

Forty-six (21·1 per cent) of 218 enrolled patients had a positive bacterial culture of the lavage fluid. Incisional SSI developed in 26 (57 per cent) of these 46 patients and in 13 (7·6 per cent) of 172 patients with a negative lavage culture (P &lt; 0·001). Organ/space SSI developed in 32 patients with a positive lavage culture (70 per cent) and in 43 of those with a negative culture (25·0 per cent) (P &lt; 0·001). Grade B/C pancreatic fistula was observed in 22 (48 per cent) and 48 (27·9 per cent) respectively of patients with positive and negative lavage cultures (P = 0·010). Postoperative hospital stay was longer in patients with a positive lavage culture (28 days versus 21 days in patients with a negative culture; P = 0·028). Multivariable analysis revealed that internal biliary drainage, combined colectomy and a longer duration of surgery were significant risk factors for positive bacterial culture of the lavage fluid.

Conclusion

Intraoperative bacterial contamination has an adverse impact on the development of SSI and grade B/C pancreatic fistula following pancreaticoduodenectomy.

Microwave Magnetochiral Dichroism in the Chiral-Lattice Magnet Cu_{2}OSeO_{3}

Through broadband microwave spectroscopy in Faraday geometry, we observe distinct absorption spectra accompanying magnetoelectric (ME) resonance for oppositely propagating microwaves, i.e., directional dichroism, in the multiferroic chiral-lattice magnet Cu_{2}OSeO_{3}. The magnitude of the directional dichroism critically depends on the magnetic-field direction. Such behavior is well accounted for by considering the relative direction of the oscillating electric polarizations induced via the ME effect with respect to microwave electric fields. Directional dichroism in a system with an arbitrary form of ME coupling can be also discussed in the same manner.