Electrohydrodynamics of diffuse porous colloids

The present article deals with the electrohydrodynamic motion of diffuse porous particles governed by an applied DC electric field. The spatial distribution of monomers as well as the charge distribution across the particle are considered to follow sigmoidal distribution involving decay length. Such a parameter measures the degree of inhomogeneity of the monomer distribution across the particle. The diffuse porous particles resemble several colloidal entities which are often seen in the environment as well as in biological and pharmaceutical industries. Considering the impact of bulk pH and ion steric effects, we modelled the electrohydrodynamics of such porous particulates based on the modified Boltzmann distribution for the spatial distribution of electrolyte ions and the Poisson equation for electric potential as well as the conservation of mass and momentum principles. We adopt regular perturbation analysis with weak field assumption and the perturbed equations are solved numerically to calculate the electrophoretic mobility and neutralization fraction of the particle charge during its motion as well as fluid collection efficiency. We further deduced the closed form relation between the drag force experienced by the charged porous particle and the fluid collection efficiency. In addition to the numerical results, we further derived the closed form analytical results for all the intrinsic parameters indicated above derived within the Debye-Hückel electrostatic framework and homogeneous distribution of monomers within the particle for which the decay length vanishes. The deduced mathematical results as indicated above will be useful to analyze several electrostatic and hydrodynamic features of a wide class of porous particulate and environmental entities.

Loss of Autophagy Disrupts Stemness of Ameloblast-Lineage Cells in Aging

Autophagy is one of the intracellular degradation pathways and maintains cellular homeostasis, regulating the stress response, cell proliferation, and signal transduction. To elucidate the role of autophagy in the maintenance of dental epithelial stem cells and the subsequent enamel formation, we analyzed autophagy-deficient mice in epithelial cells (Atg7f/f;KRT14-Cre mice), focusing on the influence of aging and stress environments. We also performed in vitro cell and organ culture experiments with an autophagy inhibitor. In young Atg7f/f;KRT14-Cre mice, morphological change was not obvious in maxillary incisors, except for the remarkable cell death in the stratum intermedium of the transitional stage. However, under stress conditions of hyperglycemia, the incisor color changed to white in diabetes Atg7f/f;KRT14-Cre mice. Regarding dental epithelial stem cells, the shape of the apical bud region of the incisor became irregular with age, and odontoma was formed in aged Atg7f/f;KRT14-Cre mice. In addition, the shape of apical bud culture cells of Atg7f/f;KRT14-Cre mice became irregular and enlarged atypically, with epigenetic changes during culture, suggesting that autophagy deficiency may induce tumorigenesis in dental epithelial cells. The epigenetic change and upregulation of p21 expression were induced by autophagy inhibition in vivo and in vitro. These findings suggest that autophagy is important for the regulation of stem cell maintenance, proliferation, and differentiation of ameloblast-lineage cells, and an autophagy disorder may induce tumorigenesis in odontogenic epithelial cells.

Diffusiophoresis of Weakly Charged Fluid Droplets in a General Electrolyte Solution: An Analytical Theory

Owing to the importance of analytical results for electrokinetics of colloidal entities, we performed a mathematical analysis to determine the closed form analytical results for the diffusiophoretic velocity of a hydrophobic and polarizable fluid droplet. A comprehensive mathematical model is developed for diffusiophoresis, considering the background aqueous medium as general electrolytes (e.g., binary valence-symmetric/asymmetric electrolytes and a mixed solution of binary electrolytes). We performed our analysis under a weak concentration gradient, and the analytical results for diffusiophoretic velocity are calculated within the Debye-Hückel electrostatic framework. The exact form of the diffusiophoretic velocity is further approximated with negligible error, and the approximate form is found to be free from any of the cumbersome exponential integrals and thus very convenient for practical use. The present theory also covers the diffusiophoresis of perfectly dielectric as well as perfectly conducting droplets as its limiting case. In addition, we have further derived a number of closed form expressions for diffusiophoretic velocity pertaining to several particular cases, and we observed that the derived limit correctly recovers the available existing analytical results for diffusiophoretic velocity. Thus, the present analytical theory for diffusiophoresis can be applied to a wide class of fluidic droplets, e.g., hydrophobic and dielectric oil/conducting mercury droplets, air bubbles, nanoemulsions, as well as any polarizable and hydrophobic fluidic droplet suspended in a solution of general electrolytes.

Cuspal Shape Alterations by Bmp4 Directing Cell Proliferation and Apoptosis

The enamel knot (EK), located at the center of cap stage tooth germs, is a transitory cluster of nondividing epithelial cells. The EK acts as a signaling center that provides positional information for tooth morphogenesis and regulates the growth of tooth cusps. To identify species-specific cuspal patterns, this study analyzed the cellular mechanisms in the EK that were related to bone morphogenetic protein (Bmp), which plays a crucial role in cell proliferation and apoptosis. To understand the cellular mechanisms in the EK, the differences between 2 species showing different cuspal patterning, mouse (pointy bunodont cusp) and gerbil (flat lophodont cusp), were analyzed with quantitative reverse transcriptase polymerase chain reaction and immunofluorescent staining. Based on these, we performed protein-soaked bead implantation on tooth germs of the 2 different EK regions and compared the cellular behavior in the EKs of the 2 species. Many genes related with cell cycle, cell apoptosis, and cell proliferation were involved in BMP signaling in the EK during tooth development. A comparison of the cell proliferation and apoptosis associated with Bmp revealed distinctive patterns of the cellular mechanisms. Our findings indicate that the cellular mechanisms, such as cell proliferation and apoptosis, in the EK are related to Bmp4 and play an important role in tooth morphogenesis.

Electrophoresis of Dielectric and Hydrophobic Spherical Fluid Droplets Possessing Uniform Surface Charge Density

The present article deals with the theoretical study on electrophoresis of hydrophobic and dielectric spherical fluid droplets possessing uniform surface charge density. Unlike the ideally polarizable liquid droplet bearing constant surface ζ-potential, the tangential component of the Maxwell stress is nonzero for dielectric fluid droplets with uniform surface charge density. We consider the continuity of the tangential component of total stress (sum of the hydrodynamic and Maxwell stresses) and jump in dielectric displacement along the droplet-to-electrolyte interface. The typical situation is considered here for which the interfacial tension of the fluid droplet is sufficiently high so that the droplet retains its spherical shape during its motion. The present theory can be applied to nanoemulsions, hydrophobic oil droplets, gas bubbles, droplets of immiscible liquid suspended in aqueous medium, etc. Based on weak field and low charge assumptions and neglecting the Marangoni effect, the resultant electrokinetic equations are solved using linear perturbation analysis to derive the closed form expression for electrophoretic mobility applicable for the entire range of Debye-Hückel parameter. We further deduced an alternate approximate expression for electrophoretic mobility without involving exponential integrals. Besides, we have derived analytical results for mobility pertaining to various limiting cases. The results are further illustrated to show the impact of pertinent parameters on the overall electrophoretic mobility.

Gel Electrophoresis of a Hydrophobic Liquid Droplet with an Equipotential Slip Surface

A theoretical study has been carried out on the electrophoresis of charged dielectric liquid droplets with an equipotential and hydrodynamically slipping surface moving in a quenched polymeric charged hydrogel medium. The liquid inside the droplet is electrically neutral. The Brinkman-Debye-Bueche model is employed to study the gel electrophoresis of such a hydrophobic and equipotential liquid droplet considering the long-range hydrodynamic interaction between a migrating droplet and the gel skeleton. Within the weak field and Debye-Hückel electrostatic framework, we derive an original closed-form expression for electrophoretic mobility, which further recovers the existing mobility expressions derived under several limiting conditions. The derived expressions for electrophoretic mobility explicitly involve exponential integrals, which are not so convenient for practical applications. Thus, the exact forms of the electrophoretic mobility under various electrohydrodynamic conditions are further approximated to make them free from exponential integrals. The approximate forms are found to be in excellent agreement with the exact results with maximum relative errors of about 1.5%.

Electrophoresis of Liquid-Layer Coated Particles: Impact of Ion Partitioning and Ion Steric Effects

The biomimetic core-shell nanoparticles coated with membranes of various biological cells have attracted significant research interest, because of their extensive applications in targeted drug delivery systems. The cell membrane consists of a lipid bilayer, which can be regarded as a two-dimensional oriented viscous liquid with low dielectric permittivity, compared to a bulk aqueous medium. Such a liquid layer comprised of cell membrane may bear additional mobile charges, because of the presence of free lipid molecules or charged surfactant molecules, which further results in nonzero charge along the surface of the peripheral layer. In this article, we present an analytical theory for electrophoresis of such cell membrane coated functionalized nanoparticles in the extent of electrolyte solution, considering the combined effects of finite ion size and of ion partitioning. Going beyond the Debye-Huckel approximations, we propose an analytical theory for Donnan potential and electrophoretic mobility. The derived expressions are applicable for moderate to highly charged undertaken core-shell particles when the thickness of the peripheral liquid layer greatly exceeds the electric double layer thickness. The impact of pertinent parameters on the electrophoretic response of such a particle is further discussed.

A simplified model for gel electrophoresis of a hydrophobic rigid colloid

Electrophoresis of a charged dielectric hydrophobic colloid embedded in a charged hydrogel medium is addressed. A slip velocity condition at the particle surface is considered. The characteristic of the gel electrophoresis is different compared with the free-solution electrophoresis due to the presence of immobile charges of the gel medium, which induces a strong background electroosmotic flow and modifies the Debye layer of the colloid. The gel electrophoresis of the dielectric hydrophobic charged colloid is made based on first-order perturbation analysis. A closed form solution involving simple exponential integrals for the mobility is derived, which reduces to several existing mobility expressions under limiting conditions such as for the gel electrophoresis of hydrophilic particles and a hydrophobic colloid in free-solution electrophoresis. We find that the mobility reversal is achieved by varying the Debye length or gel permeability. For the present first-order perturbation analysis, unlike free-solution electrophoresis, the particle dielectric permittivity is found to influence the mobility. One of the intriguing features of the present study is the derivation of the simplified mobility expression, which can be easily computed for a given set of parameter values.

Effect of core hydrophobicity on the electrophoresis of pH-regulated soft particles

We propose a theoretical study on the electrophoresis of core-shell composite soft particles considering the effect of hydrodynamic slip length of the hydrophobic inner core. The surface of the inner core as well as the soft polymeric shell bear zwitterionic functional groups and the charged conditions depend on the nearby micro-environment. Within a low potential and weak electric field framework, the mathematical equations of the generalized electrokinetic theory for soft surfaces are solved analytically subject to appropriate boundary conditions, and a general electrophoretic mobility expression in an integral form involving the pH-dependent electrostatic potential is derived. With the help of suitable numerical schemes, electrophoretic mobility can easily be obtained. The effect of hydrophobicity of the inner core on the electrophoretic mobility of pH-regulated soft particles is illustrated for a wide range of pertinent parameters.

Electrokinetics of Concentrated Suspension of Soft Particles with pH-Regulated Volumetric Charges

This article presents a theoretical study on the electrokinetics of concentrated suspension of charge-regulated soft particles under a weak electric field and low potential assumptions. The inner core of the undertaken particle is "semisoft" in nature, which allows ion penetration while the fluid cannot flow within it, and the outer soft polymeric shell allows the flow of the ionized fluid. In addition, the inner core and the outer polyelectrolyte layer (PEL) bear pH-regulated basic and acidic functional groups, respectively. The Poisson-Boltzmann equation-based mathematical model was adopted here for electric potential. The fluid flow across the electrolyte medium and PEL is governed by the Stokes equation and the Darcy-Brinkman equation, respectively. The Kuwabara's unit cell model (J. Phys. Soc. Japan, 1959, 14, 522-527) was invoked to observe the effect of the interaction between the neighboring particles in a concentrated suspension. A first order perturbation technique was used to determine the mean electrophoretic mobility of the undertaken soft particles in a concentrated suspension. The effect of pH and concentration of bulk electrolyte, electrohydrodynamic properties of both the inner core and PEL, on the mean electrophoretic mobility has been studied extensively. In addition, the results have been presented for the neutralization factor that measures the fraction of fixed charges neutralized by the mobile counterions.

Electrophoresis of dielectric and immiscible-liquid-layer-encapsulated colloids in aqueous media

In this paper we consider the electrophoresis of a functionalized nanoparticle in electrolyte solution. The undertaken particle is comprised of a rigid inner core encapsulated with a layer of dielectric liquid (e.g., oil or lipid layer), which is immiscible to the bulk aqueous medium. The peripheral liquid layer of the undertaken nanoparticle contains mobile charges due to presence of solubilized surfactants. The mobile electrolyte ions can penetrate across the peripheral layer depending on the difference in the Born energy of the both phases. Such types of nanoparticles have received substantial attention due to their widespread applications in biomedical research. The electric double layer (EDL) is governed by the linearized Poisson-Boltzmann equation under a low potential limit and the electroosmotic flow field is governed by modified Stokes equation. We adopt the flat-plate formalism to obtain the closed analytical expression for the electrophoretic mobility of the undertaken particle under a thin EDL approximation. The dependence of electrophoretic mobility on the pertinent parameters is also illustrated.

Impact of ion-steric and ion-partitioning effects on electrophoresis of soft particles

A theoretical study on the electrophoresis of a soft particle is made by taking into account the ion steric interactions and ion partitioning effects under a thin Debye layer consideration with negligible surface conduction. Objective of this study is to provide a simple expression for the mobility of a soft particle which accounts for the finite-ion-size effect and the ion partitioning arise due to the Born energy difference between two media. The Donnan potential in the soft layer is determined by considering the ion steric interactions and the ion partitioning effect. The volume exclusion due to the finite ion size is considered by the Carnahan-Starling equation and the ion partitioning is accounted through the difference in Born energy. The modified Poisson-Boltzmann equation coupled with Stokes-Darcy-Brinkman equations are considered to determine the mobility. A closed-form expression for the electrophoretic mobility is obtained, which reduces to several existing expressions for mobility under various limiting cases.

Electrokinetic ion transport and fluid flow in a pH-regulated polymer-grafted nanochannel filled with power-law fluid

In this article, we have discussed extensively electrokinetic ion transport and fluid flow through a slit polymer-grafted nanochannel filled with power-law fluid. The rigid walls of the channel are coated with the ion and fluid penetrable polymer layer containing a pH-regulated zwitterionic functional group (e.g., succinoglycan). The mathematical model is based on the non-linear Poisson-Boltzmann equation for electric double layer potential and the flow field within the polymer layer is governed by a modified Darcy-Brinkman equation; the Cauchy momentum equation governs the fluid flow outside of the polymer layer along with the equation of continuity for incompressible fluid. In order to consider a wide range of pertinent parameters, we adopt a finite difference based numerical tool to solve the coupled set of governing equations. We have analyzed several interesting features of electrokinetic transport phenomena through such a polymer-grafted nanochannel for a wide range of electrostatic and hydrodynamic properties of the polymer layer, parameters describing the non-Newtonian rheology of the background fluid, and the pH and concentration of the bulk electrolyte. In addition, we have also illustrated the ionic current across the undertaken nanochannel and observed that it can be either cation selective, anion selective or non-selective, depending on the critical choice of the pertinent parameters.

Functional Expression of Sodium-Dependent Glucose Transporter in Amelogenesis

Glucose is an essential source of energy for mammalian cells and is transported into the cells by glucose transporters. There are 2 types of glucose transporters: one is a passive glucose transporter, GLUT (SLC2A), and the other is a sodium-dependent active glucose transporter, SGLT (SLC5A). We previously reported that the expression of GLUTs during tooth development is precisely and spatiotemporally controlled and that the glucose uptake mediated by GLUT1 plays a crucial role in early tooth morphogenesis and tooth size determination. This study aimed to clarify the localization and roles of SGLT1 and SGLT2 in murine ameloblast differentiation by using immunohistochemistry, immunoelectron microscopy, an in vitro tooth organ culture experiment, and in vivo administration of an inhibitor of SGLT1/2, phloridzin. SGLT1, which has high affinity with glucose, was immunolocalized in the early secretory ameloblasts and the ruffle-ended ameloblasts in the maturation stage. However, SGLT2, which has high glucose transport capacity, was observed in the stratum intermedium, papillary layer, and ameloblasts at the maturation stage and colocalized with Na⁺-K⁺-ATPase. The inhibition of SGLT1/2 by phloridzin in the tooth germs induced the disturbance of ameloblast differentiation and enamel matrix formation both in vitro (organ culture) and in vivo (mouse model). The expression of SGLT1 and SGLT2 was significantly upregulated in hypoxic conditions in the ameloblast-lineage cells. These findings suggest that the active glucose uptake mediated by SGLT1 and SGLT2 is strictly regulated and dependent on the intra- and extracellular microenvironments during tooth morphogenesis and that the appropriate passive and active glucose transport is an essential event in amelogenesis.

[A Case of Hepatocellular Carcinoma with Portal Vein Tumor Thrombus Successfully Treated by Three-Dimensional Conformal Radiotherapy]

A man in his 50s was referred to our hospital with a liver tumor detected by ultrasonography during a medical checkup. Enhanced CT scan and MRI showed hepatocellular carcinoma(HCC)in S8 of the liver. Laparoscopic partial hepatectomy was performed. The histopathological findings showed well differentiated HCC. Two years later, his serum PIVKA-Ⅱ levels were slightly elevated. A new lesion was detected by US, CT, and MRI at S5 of the liver. A second laparoscopic partial hepatectomy was performed. The histopathological findings showed moderately differentiated HCC. After 1 year, MRI detected 2 new HCCs(S4, S8). The tumor at S8 had invaded the right branch of the portal vein. There was no indication for right hepatectomy because of liver dysfunction. Lipiodol-TACE followed by DEB-TACE was not effective on the tumor. The HCC at S8 had enlarged and formed a portal vein tumor thrombus. PIVKA- / Ⅱ levels increased to 3,596 mAU/mL. The patient was adminis- tered Three-dimensional conformal radiotherapy(45 Gy/15 Fr)and his PIVKA-Ⅱ levels decreased to the normal range. He has been followed-up without recurrences for 2 years and 9 months.

Resistive exercise in astronauts on prolonged spaceflights provides partial protection against spaceflight-induced bone loss

Bone loss in astronauts during spaceflight may be a risk factor for osteoporosis, fractures and renal stone formation. We previously reported that the bisphosphonate alendronate, combined with exercise that included an Advanced Resistive Exercise Device (ARED), can prevent or attenuate group mean declines in areal bone mineral density (aBMD) measured soon after ~ 6-month spaceflights aboard the International Space Station (ISS). It is unclear however if the beneficial effects on postflight aBMD were due to individual or combined effects of alendronate and ARED. Hence, 10 additional ISS astronauts were recruited who used the ARED (ARED group) without drug administration using similar measurements in the previous study, i.e., densitometry, biochemical assays and analysis of finite element (FE) models. In addition densitometry data (DXA and QCT only) were compared to published data from crewmembers (n = 14-18) flown prior to in-flight access to the ARED (Pre-ARED). Group mean changes from preflight (± SD %) were used to evaluate effects of countermeasures as sequentially modified on the ISS (i.e., Pre-ARED vs. ARED; ARED vs. Bis+ARED). Spaceflight durations were not significantly different between groups. Postflight bone density measurements were significantly reduced from preflight in the Pre-ARED group. As previously reported, combined Bis+ARED prevented declines in all DXA and QCT hip densitometry and in estimates of FE hip strengths; increased the aBMD of lumbar spine; and prevented elevations in urinary markers for bone resorption during spaceflight. ARED without alendronate partially attenuated declines in bone mass but did not suppress biomarkers for bone resorption or prevent trabecular bone loss. Resistive exercise in the ARED group did not prevent declines in hip trabecular vBMD, but prevented reductions in cortical vBMD of the femoral neck, in FE estimate of hip strength for non-linear stance (NLS) and in aBMD of the femoral neck. We conclude that a bisphosphonate, when combined with resistive exercise, enhances the preservation of bone mass because of the added suppression of bone resorption in trabecular bone compartment not evident with ARED alone.

[A Case of Advanced Cardia Gastric Cancer with Pernicious Anemia]

A 70s male was referred to our hospital with anemia that was detected during a medical checkup. Upper gastrointestinal endoscopy showed advanced cardia gastric cancer. A diagnosis of pernicious anemia was made due to the macrocytic hyperchromic anemia and detection of intrinsic factor antibody. A CT scan showed fundic wall thickening and regional lymph node metastasis. After anemia improved following vitamin B12 injection, total gastrectomy with lymphadenectomy was performed. The histopathological findings showed adenocarcinoma(tub1>tub2), Type2 , pT3(SS), pN1(2/24), Stage ⅡB, INF b, ly1, v2, PM0, DM0, EW(+), pR1. He was administered systematic chemotherapy using S-1 for one year after surgery and has been followed up without recurrence for 5 years.

Ion partitioning effect on the electrophoresis of a soft particle with hydrophobic core

A theoretical study on the electrophoresis of a soft particle made up of a charged hydrophobic inner core surrounded by polyelectrolyte layer (PEL) is made. The dielectric permittivity of the PEL and aqueous solution are considered to be different, which creates the ion partitioning effect. The ion partitioning effect, which is accounted by the Born energy difference, modifies the distribution of mobile ions in the PEL and hence alters the particle electrophoresis. The combined effects of core hydrophobicity and the ion partitioning effect on the mobility are determined based on the Debye-Huckel approximation under a thin Debye layer assumption. An analytic expression for the electrophoretic mobility taking into account the core hydrophobicity and ion partitioning effect is obtained. The occurrence of zero mobility and reversal of mobility of the soft particle is illustrated.

Msx2 Prevents Stratified Squamous Epithelium Formation in the Enamel Organ

Tooth enamel is manufactured by the inner enamel epithelium of the multilayered enamel organ. Msx2 loss-of-function mutation in a mouse model causes an abnormal accumulation of epithelial cells in the enamel organ, but the underlying mechanism by which Msx2 regulates amelogenesis is poorly understood. We therefore performed detailed histological and molecular analyses of Msx2 null mice. Msx2 null ameloblasts and stratum intermedium (SI) cells differentiated normally in the early stages of amelogenesis. However, during subsequent developmental stages, the outer enamel epithelium (OEE) became highly proliferative and transformed into a keratinized stratified squamous epithelium that ectopically expressed stratified squamous epithelium markers, including Heat shock protein 25, Loricrin, and Keratin 10. Moreover, expression of hair follicle-specific keratin genes such as Keratin 26 and Keratin 73 was upregulated in the enamel organ of Msx2 mutants. With the accumulation of keratin in the stellate reticulum (SR) region and subsequent odontogenic cyst formation, SI cells gradually lost the ability to differentiate, and the expression of Sox2 and Notch1 was downregulated, leading to ameloblast depolarization. As a consequence, the organization of the Msx2 mutant enamel organ became disturbed and enamel failed to form in the normal location. Instead, there was ectopic mineralization that likely occurred within the SR. In summary, we show that during amelogenesis, Msx2 executes a bipartite function, repressing the transformation of OEE into a keratinized stratified squamous epithelium while simultaneously promoting the development of a properly differentiated enamel organ competent for enamel formation.

[Jejunal Interposition after Totally Laparoscopic Proximal Gastrectomy Using Overlap Method]

There are several reconstruction methods in laparoscopic proximal gastrectomy(LPG)for earlygastric cancer at the upper part of the stomach. To prevent the esophageal reflux after gastrectomy, we chose jejunal interposition(JI)via the retrocolic route for LPG. We performed totallyLPG with JI using overlap method.

METHODS

Five ports were placed. After the lymph nodes dissection bythe standard procedure, the esophagus and the proximal side of the stomach were transected byliner staplers. The jejunum was moved to the upper abdomen through the small hole of the mesocolon. The interposing jejunum was made, and the esophagojejunostomyand jejunogastrostomywere done byusing overlap method. At the end, the jujunum was pulled under the mosocolon escluding the interposing jejunum. The JI reconstruction via a retrocolic route after LPG was completed.

DISCUSSION

Following LPG, the JI reconstruction is not so popular because the surgical procedure is complicated. In our technique, the JI reconstruction accomplished easier byoverlap method.

CONCLUSION

Our procedure is a considerable operation of reconstruction following LPG.

[A Case of Long-Term Survival of Breast Cancer with Lymph Node and Liver Metastases Treated with Sequential Anti-HER2 Drugs, Chemotherapy, and Endocrine Therapy]

A 50s-year-old woman underwent left partial mastectomy with axillary lymphadenectomy for breast cancer. Histological examination indicated invasive ductal carcinoma, pT1c, pN0, Stage I , ly(+), ER(+), PgR(+). She received adjuvant therapy with tamoxifen and 50 Gy of irradiation to the residual breast. Four years after mastectomy, she was found to have left Rotter lymph node metastasis; then, anastrozole was administered instead of tamoxifen. Nine months later, she was found to have liver metastasis. Immunohistostaining revealed that the breast cancer was HER2-positive; she received AC followed by paclitaxel(PTX)with trastuzumab(T), and achieved complete response(CR). Subsequently, abdominal, cervical lymph node, and liver metastases appeared. Letrozole followed by lapatinib with capecitabine, FEC100, PTX with T, eribulin, S-1, docetaxel with pertuzumab and T, everolimus with exemestane, bevacizumab, and PTX were then administered, resulting in long-term disease control. Sixteen years after mastectomy, she receives outpatient chemotherapy in performance status 1 state.

[Two Cases of Stage IV Pancreatic Cancer Has Gained Relatively Long Free Survival in Multimodality Therapy]

We experienced 2 cases in which Stage IV pancreatic cancer(General rules for the study of pancreatic cancer, The 6th edition, Japanese Pancreas Society)underwent chemotherapy and radiotherapy after surgical operation and had relatively long term relapse-free survival. Local control by adding radiation therapy to surgical resection and suppressing the distant metastases in adjuvant chemotherapy may improve the prognosis.

Effect of hydrophobic core on the electrophoresis of a diffuse soft particle

Electrophoresis of a diffuse soft particle with a charged hydrophobic core is considered under the weak field and low charge density assumptions. The hydrophobic surface of the core is coated with a diffuse polyelectrolyte layer (PEL) in which a gradual transition of the polymer segment distribution from the impenetrable core to the surrounding electrolyte medium is considered. A mathematical model is adopted to analyse the impact of the core hydrophobicity on the diffuse soft particle electrophoresis. The mobility based on the present model for the limiting cases such as bare colloids with hydrophobic core and soft particles with no-slip rigid cores are in good agreement with the existing results. The presence of PEL charges produces the impact of the core hydrophobicity on the soft particle mobility different from the corresponding bare colloid with hydrophobic surface in an electrolyte medium. The impact of the core hydrophobicity is subtle when the hydrodynamic screening length of the PEL is low. Reversal in mobility can be achieved by tuning the core hydrophobicity for an oppositely charged core and PEL.

[A Case of Recurrent Inflammatory Breast Cancer Treated Using Multidisciplinary Therapy]

The patient was a 65-year-old woman who underwent segmental mastectomy for left breast cancer 5 years ago. The pathological diagnosis ofthe tumor was noninvasive ductal carcinoma, TisN0M0 and Stage 0. Postoperative radiation therapy was performed, but chemotherapy and hormone therapy were not administered. The patient presented with redness of the residual left breast. Skin biopsy showed lymphatic invasion of adenocarcinoma, and the patient was diagnosed with inflammatory carcinoma ofthe breast. After 4 cycles ofAC followed by 4 cycles ofdocetaxel, the mass was diminished and the redness disappeared. Total mastectomy with wide skin resection and axillary lymph node dissection was performed. The pathological diagnosis revealed scirrhous carcinoma ofthe left residual breast(T3N0, Stage II B, s, f, g, margin[-], ly0, v0, ER[+], PgR[+], HER2[1+]). She received treatment with an aromatase inhibitor, and 2 years after the operation is alive with no recurrence.

[A Case of Squamous Cell Carcinoma of the Breast]

A 67-year-old woman presented with a 3 cm palpable mass in the lower lateral quadrant of her right breast. Mammography and ultrasonography showed a mass with an irregular border. Using fine needle aspiration biopsy and cytology, we detected malignant cells with keratosis, and made a diagnosis of squamous cell carcinoma(SCC). We performed total mastectomy with axillary lymph node dissection. Histologically, the tumor was identified as SCC with keratinization and a component of scirrhous adenocarcinoma; estrogen and progesterone receptor expression were not elevated. The tumor tested negative for HER2. The patient did not receive any adjuvant chemotherapy and is alive with no recurrence 13 years after surgery.

Osteopontin Is Essential for Type I Collagen Secretion in Reparative Dentin

Osteopontin (OPN) is a highly phosphorylated glycoprotein that is a prominent component of the mineralized extracellular matrix of bone. The secretion of OPN by immunocompetent cells plays a role in the differentiation of odontoblast-like cells during pulpal healing following tooth transplantation. This study aimed to clarify the role of OPN during reparative dentinogenesis. A groove-shaped cavity was prepared on the mesial surface of the upper first molars of wild-type (WT) and Opn knockout (KO) mice, and the samples were collected at intervals of 1 to 14 d. The demineralized sections were processed for immunohistochemistry for Ki67, nestin, OPN, dentin sialoprotein (DSP), integrin αvβ3, and type I collagen; in situ hybridization for Opn, col1a1, and dentin sialophosphoprotein (Dspp); and apoptosis assay. For the loss and gain of function experiments, an in vitro culture assay for evaluating dentin-pulp complex regeneration was performed. On day 1 in WT mice, odontoblasts beneath the affected dentin lost nestin immunoreactivity. On day 3, the expression of Opn was recognized at the mesial dental pulp, and OPN was deposited along the predentin-dentin border. Nestin-positive newly differentiated odontoblast-like cells expressed both Dspp and col1a1 and showed positive immunoreactivity for integrin αvβ3, DSP, and type I collagen. Until day 14, reparative dentin formation continued next to the preexisting dentin at the mesial coronal pulp. In contrast, there was no reparative dentin in the Opn KO mice where nestin- and DSP-positive newly differentiated odontoblast-like cells lacked immunoreaction for type I collagen. The in vitro organ culture demonstrated that the administration of recombinant OPN rescued the type I collagen secretion by odontoblast-like cells in the Opn KO mice. The results suggested that the deposition of OPN at the calcification front is essential for the type I collagen secretion by newly differentiated odontoblast-like cells to form reparative dentin during pulpal healing following cavity preparation.

GaAlAs laser-induced pulp mineralization involves dentin matrix protein 1 and osteopontin expression

OBJECTIVES

GaAlAs lasers induce pulp mineralization by promoting reparative dentinogenesis. This study analyzed the expression of dentin matrix protein 1 (DMP1) and osteopontin in GaAlAs laser-irradiated rat molars, to examine the hypothesis that these proteins play a role in the laser-induced reparative dentinogenic process.

MATERIALS AND METHODS

The mesial surfaces of the upper first molars of 8-week-old Wistar rats were irradiated with a pulsed GaAlAs laser. After 1-14 days, mRNA expression of DMP1 and osteopontin in the coronal pulp was analyzed using real-time PCR. DMP1, osteopontin, and heat shock protein 25 (HSP25) were immunolocalized at 1-21 days.

RESULTS

The pulp exhibited a degenerative zone in its mesial portion on days 1-3, and progressive formation of reparative dentin lined with HSP25-immunoreactive odontoblast-like cells, from day 7 onwards. DMP1 and osteopontin mRNA expression were significantly upregulated on days 1-7 and 3-7, respectively. From day 7 onwards, DMP1 and osteopontin immunoreactivity colocalized along the boundary between the primary and reparative dentin.

CONCLUSION

GaAlAs laser irradiation of rat molars induced upregulated DMP1 and osteopontin mRNA expression in the coronal pulp, followed by the formation of reparative dentin and the colocalization of DMP1 and osteopontin immunoreactivity at the site at which this tissue first appeared.

[A Case of Laparoscopic Gastrectomy for Gastric GIST after Neoadjuvant Chemotherapy with Imatinib Mesylate]

We report the case of a 68-year-old woman who underwent laparoscopic gastrectomy for a gastric gastrointestinal stromal tumor (GIST) after neoadjuvant chemotherapy with imatinib mesylate. After conducting gastroscopy because of weight loss and anemia, we identified a submucosal tumor in the cardia. A GIST of 8 cm in diameter invaded the pancreatic tail and excluded the splenic vein. We administered imatinib 400 mg/day as neoadjuvant chemotherapy. We performed laparoscopic partial gastrectomy 5 months after the initiation of chemotherapy. According to the histopathological diagnosis, the surgical margin was positive. As an additional excision, we performed laparoscopic proximal gastrectomy. Without postoperative complications, it passes smoothly as of 5 months after surgery.

Recombinant soluble thrombomodulin for postoperative disseminated intravascular coagulation

BACKGROUND

Thrombomodulin is a thrombin receptor on the endothelial cell surface that plays an important role in the regulation of intravascular coagulation. The purpose of this study was to evaluate the efficacy and safety of treatment with recombinant human soluble thrombomodulin (rhTM) for patients with septic-disseminated intravascular coagulation (DIC) associated with gastroenterological surgery.

MATERIALS AND METHODS

From April 2011-September 2013, 201 patients with DIC associated with gastroenterological surgery were treated in 16 institutions in Kumamoto, Japan. The patients were diagnosed according to the Japanese Association for Acute Medicine DIC scoring system. The clinical course, mortality rate at 28 d, and adverse events were evaluated retrospectively.

RESULTS

Forty-five patients were excluded because they did not meet the Japanese Association for Acute Medicine DIC criteria or had an insufficient duration of drug administration. Thus, 156 patients were analyzed. Of these patients, 107 received rhTM at the discretion of the attending surgeon and 49 did not. The most common reason for surgery in both groups was peritonitis due to perforation of the colon. Within 7 d, the platelet count, prothrombin time-international normalized ratio, DIC score, neutrophil count, and C-reactive protein level significantly improved in the rhTM group compared with those in the control. Treatment with rhTM was significantly associated with reduced inhospital mortality at 28 d. The incidence of adverse events did not differ between the two groups.

CONCLUSIONS

Therapy with rhTM may be associated with reduced inhospital mortality in patients with septic DIC associated with gastroenterological surgery without increasing adverse events.

Loss of p53 in stromal fibroblasts enhances tumor cell proliferation through nitric-oxide-mediated cyclooxygenase 2 activation

Overexpression of cyclooxygenase 2 (COX-2) by stromal fibroblasts plays a critical role in the early stage of carcinogenesis. COX-2 expression is thought to be positively or negatively regulated by inflammatory chemical mediators or tumor suppressors. In this study, the contributions of inducible nitric oxide synthase (iNOS) and p53 to COX-2 expression were examined using mouse embryonic fibroblasts (MEFs) from wild-type, p53-deficient, iNOS-deficient, and p53/iNOS-deficient mice. These MEFs were treated with 1 μg/mL of lipopolysaccharide and 100 IU/mL of interferon gamma for up to 72 h. iNOS and COX-2 expression were analyzed by Western blotting. iNOS was induced earlier (16 h) in p53-deficient MEFs than in wild-type MEFs (48 h). Elevated expression of COX-2 was sustained for a longer duration in the p53-deficient MEFs. In contrast, COX-2 expression was reduced earlier in the iNOS-deficient MEFs. Addition of an exogenous NO donor (0.8 mM of S-nitroso-l-glutathione) to the iNOS-deficient MEFs augmented COX-2 expression. Co-culture with stimulated p53-deficient MEFs promoted cell proliferation of mouse rectal polyploid carcinoma CMT93 cells, but treatment with a COX-2-specific inhibitor counteracted this effect. These results suggest that loss of function of the p53 gene in stromal fibroblasts enhances COX-2 expression by enhancing iNOS expression and the resultant production of NO, contributing to the promotion of tumor growth.

Contribution of Donor and Host Mesenchyme to the Transplanted Tooth Germs

Autologous tooth germ transplantation of immature teeth is an alternative method of tooth replacement that could be used instead of dental implants in younger patients. However, it is paramount that the dental pulp remain vital and that root formation continue in the transplanted location. The goal of this study is to characterize the healing of allogenic tooth grafts in an animal model using GFP-labeled donor or host postnatal mice. In addition, the putative stem cells were labeled before transplantation with a pulse-chase paradigm. Transplanted molars formed cusps and roots and erupted into occlusion by 2 wk postoperatively. Host label-retaining cells (LRCs) were maintained in the center of pulp tissue associating with blood vessels. Dual labeling showed that a proportion of LRCs were incorporated into the odontoblast layer. Host cells, including putative dendritic cells and the endothelium, also immigrated into the pulp tissue but did not contribute to the odontoblast layer. Therefore, LRCs or putative mesenchymal stem cells are retained in the transplanted pulps. Hertwig’s epithelial root sheath remains vital, and epithelial LRCs are present in the donor cervical loops. Thus, the dynamic donor-host interaction occurred in the developing transplant, suggesting that these changes affect the characteristics of the dental pulp.

[A case report of scirrhous gastric cancer with peritoneal dissemination treated effectively with various chemotherapy regimens after laparoscopic distal subtotal gastrectomy]

We report a 44-year-old male patient who was diagnosed with scirrhous gastric cancer with peritoneal dissemination using laparoscopy. The patient underwent a non-curative resection with laparoscopic distal subtotal gastrectomy. In addition, we placed a port into the patient's abdomen for intraperitoneal chemotherapy administration. Postoperatively, we administered capecitabine (per os)+ paclitaxel (intraperitoneally) and, after 2 cycles, the oral anticancer agent 5-FU was given. The patient died of peritonitis carcinomatosa 25 months after the operation. The combined therapies contributed to improve the quality of life, specifically oral ingestion, for 2 years.

[A case of rectal cancer treated with aggressive surgery for liver and anal metastases]

A 64-year-old man underwent laparoscopic surgery for rectal cancer and lateral lymph node dissection. The histopathological findings indicated adenocarcinoma (moderate>well), pA, pN3(4/25No 263 1/1), pM0, Stage IIIb. After the surgery, he received 12 courses of adjuvant chemotherapy with modified 5-fluorouracil Leucovorin oxaliplatin (mFOLFOX6). Liver metastasis( S8)was present, and open hepatectomy was performed 1 year after the first surgery. Three months after the second surgery, the carcinoembryonic antigen (CEA) level increased and chemotherapy TS-1 was started. However, the CEA level continued to increase, and positron emission tomography-computed tomography revealed peritoneal dissemination, and multiple lymph node, bone, and local metastases(in the liver and rectum). Accordingly, 11 courses of chemotherapy with 5- fluorouracil Leucovorin irinotecan (FOLFIRI) and bevacizumab was administered. The patient recently experienced anal bleeding during each bowel evacuation, which developed owing to the recurrence of the cancer in the anus. To improve his quality of life, the anal tumor was excised 2 years 6 months after the first surgery. Chemotherapy with FOLFIRI and bevacizumab was restarted. The CEA level stopped increasing. We think that the anal surgery did not affect our patient's prognosis but helped improve his quality of life.

[Lymphadenectomy performed along the left recurrent laryngeal nerve after anterior detachment of the esophagus via thoracoscopic esophagectomy in the prone position under artificial pneumothorax]

Thoracoscopic esophagectomy was performed in the prone position under artificial pneumothorax and did not affect the surgical area during lung ventilation; tracheal mobility was also improved. Lymphadenectomy around the left recurrent laryngeal nerve was performed by separating the left main bronchus and trachea between the esophagus and pericardium before detaching the dorsal side of the esophagus.

Temporospatial localization of dentine matrix protein 1 following direct pulp capping with calcium hydroxide in rat molars

AIM

To examine the temporospatial expression of dentine matrix protein 1 (DMP1; a noncollagenous protein involved in mineralized tissue formation), osteopontin (another noncollagenous protein detected during reparative dentinogenesis) and nestin (a marker of differentiating/differentiated odontoblasts), following direct pulp capping with calcium hydroxide in rat molars.

METHODOLOGY

The maxillary first molars of 8-week-old Wistar rats had their pulps exposed and capped with calcium hydroxide. The pulp-capped teeth were collected from 6 h to 14 days postoperatively and processed for immunohistochemistry for DMP1, osteopontin and nestin. Cell proliferation was monitored using 5-bromo-2'-deoxyuridine (BrdU) labelling.

RESULTS

The capped pulps initially exhibited superficial necrotic changes followed by the formation of new matrix and its mineralization. DMP1 immunoreactivity was observed in the matrix beneath the necrotic layer from 6 h onwards and present in the outer portion of the newly formed mineralized matrix from 7 days onwards. Osteopontin displayed a similar expression pattern, although it occupied a narrower area than DMP1 at 6 and 12 h. Nestin-immunoreactive cells appeared beneath the DMP1-immunoreactive area at 1 day, were distributed beneath the newly formed matrix at 5 days and exhibited odontoblast-like morphology by 14 days. BrdU-positive cells significantly increased at 2 and 3 days (P < 0.05) and then decreased.

CONCLUSIONS

The deposition of DMP1 at exposed pulp sites preceded the appearance of nestin-immunoreactive cells, active cell proliferation and new matrix formation after pulp capping with calcium hydroxide in rat molars, suggesting that DMP1 acts as a trigger of pulp repair. The colocalization of DMP1 and osteopontin suggests that these two proteins play complementary roles.

Facile gold nanorod purification by fractionated precipitation

An efficient and facile size- and shape-selective separation of gold nanorod (GNR) solutions is developed using a fractionated precipitation strategy. This convenient method has the benefit of eliminating nanoparticulate side products that can substantially deteriorate the quality of self-assembled nanostructures. The fabrication of advanced plasmonic metamaterials crucially depends on the capacity to supply feedstocks of high-purity building blocks.

Quantification of allergic and irritant patch test reactions using ImageJ

BACKGROUND/AIMS

It is often difficult to differentiate between allergic and irritant patch test reactions by visual inspection. The purpose of this study was to test an image analysis-based method that differentiates between the two reactions by quantifying the degree of erythema at the patch test site.

METHODS

A total of 172 Japanese patients were patch-tested with sodium lauryl sulfate (SLS) and nickel sulfate, followed by digital photography and visual evaluation of the patch test areas by dermatologists at 48 and 72 h. The digital images were converted to erythema index (EI) images by image processing, and changes in ΔEI (the difference in the EI between the patch test site and the adjacent normal skin) values were analyzed.

RESULTS

The ΔEI was significantly increased at 72 h relative to that at 48 h for positive nickel sulfate reactions (P < 0.0001), while no significant difference in the ΔEI was found for SLS reactions.

CONCLUSION

Using image analysis, allergic patch test reactions may be distinguished from irritant reactions by evaluating the change in the degree of erythema at 48 and 72 h.

Bisphosphonates as a supplement to exercise to protect bone during long-duration spaceflight

We report the results of alendronate ingestion plus exercise in preventing the declines in bone mass and strength and elevated levels of urinary calcium and bone resorption in astronauts during 5.5 months of spaceflight.

INTRODUCTION

This investigation was an international collaboration between NASA and the JAXA space agencies to investigate the potential value of antiresorptive agents to mitigate the well-established bone changes associated with long-duration spaceflight.

METHODS

We report the results from seven International Space Station (ISS) astronauts who spent a mean of 5.5 months on the ISS and who took an oral dose of 70 mg of alendronate weekly starting 3 weeks before flight and continuing throughout the mission. All crewmembers had available for exercise a treadmill, cycle ergometer, and a resistance exercise device. Our assessment included densitometry of multiple bone regions using X-ray absorptiometry (DXA) and quantitative computed tomography (QCT) and assays of biomarkers of bone metabolism.

RESULTS

In addition to pre- and post-flight measurements, we compared our results to 18 astronauts who flew ISS missions and who exercised using an early model resistance exercise device, called the interim resistance exercise device, and to 11 ISS astronauts who exercised using the newer advanced resistance exercise device (ARED). Our findings indicate that the ARED provided significant attenuation of bone loss compared with the older device although post-flight decreases in the femur neck and hip remained. The combination of the ARED and bisphosphonate attenuated the expected decline in essentially all indices of altered bone physiology during spaceflight including: DXA-determined losses in bone mineral density of the spine, hip, and pelvis, QCT-determined compartmental losses in trabecular and cortical bone mass in the hip, calculated measures of fall and stance computed bone strength of the hip, elevated levels of bone resorption markers, and urinary excretion of calcium.

CONCLUSIONS

The combination of exercise plus an antiresoptive drug may be useful for protecting bone health during long-duration spaceflight.

Pure laparoscopic hepatectomy for hepatocellular carcinoma patients with severe liver cirrhosis

Hepatocellular carcinoma often arises in cirrhotic livers. Patients with severe liver cirrhosis who undergo hepatectomy often develop postoperative liver failure, even if the hepatectomy is limited. Here, we report six patients with severe liver cirrhosis (Child-Pugh B/C and indocyanine green retention rate at 15 min ≥ 40%) who underwent pure laparoscopic hepatectomy. Their perioperative course was favorable and comparable to that of other hepatocellular carcinoma patients with mild-moderate liver cirrhosis. In patients with severe liver cirrhosis, pure laparoscopic hepatectomy minimizes the disturbance in collateral blood and lymphatic flow caused by laparotomy and liver mobilization, as well as the mesenchymal injury caused by compression of the liver. It limits complications such as massive ascites, which can lead to severe postoperative liver failure. Good candidates for the procedure include patients with severe liver cirrhosis who have tumors on the liver surface and in whom adaptation to ablation therapy is difficult and/or who experience local recurrence after repeat treatments.