Design of Ionic Liquid Formulations with Azone-Mimic Structures for Enhanced Drug Skin Permeation.

Although laurocapram (Azone) significantly enhances the skin permeation of drugs, its development was hindered by its skin irritation. We then developed an Azone-mimic ionic liquid (IL-Azone), composed of less irritating cationic ε-caprolactam and anionic myristic acid. IL-Azone dissociates to the original cation and anion in the presence of water in the formulation. We tried to select a formulation suitable for IL-Azone in the present study. Each formulation contained 5 % of either Azone or IL-Azone along with the model drug antipyrine, and skin permeation experiments of the drug were conducted. The results revealed that IL-Azone did not enhance skin permeation when combined with most formulations tested. However, a notable and rapid enhancement in skin permeation was observed when combined with white petrolatum. This effect could be attributed to the minimal water content in white petrolatum, which prevented IL-Azone degradation. Furthermore, its permeation-enhancing effects from IL-Azone in white petrolatum were more pronounced and rapid than Azone. The rapid onset observed with IL-Azone can be attributed to its degradation into its original components at the interface between the stratum corneum and the living epidermis, which results in a shorter lag time before achieving a steady-state concentration in the SC compared to Azone.

Altering the bio-inert properties of surfaces by fluorinated copolymers of mPEGMA.

Hydrophilic materials display "bio-inert properties", meaning that they are less recognized as foreign substances by proteins and cells. Such materials are often water soluble; therefore, one general approach to enable the use of these materials in various applications deals with copolymerizing hydrophilic monomers with hydrophobic ones to facilitate such resulting copolymers water insoluble. However, reducing the hydrophilic monomer amount may reduce the bio-inert properties of the material. The decrease in bio-inert properties can be avoided when small amounts of fluorine are used in copolymers with hydrophilic monomers, as presented in this article. Even in small quantities (7.9 wt%), the fluorinated monomer, 1,1,1,3,3,3-hexafluoropropan-2-yl 2-fluoroacrylate (FAHFiP), contributed to the improved hydrophobicity of the polymers of the long side-chain poly(ethylene glycol) methyl ether methacrylate (mPEGMA) bearing nine ethylene glycol units turning them water insoluble. As evidenced by the AFM deformation image, a phase separation between the FAHFiP and mPEGMA domains was observed. The copolymer with the highest amount of the fluorinated monomer (66.2 wt%) displayed also high (82 %) FAHFiP amount at the polymer-water interface. In contrast, the hydrated sample with the lowest FAHFiP/highest mPEGMA amount was enriched of three times more hydrophilic domains at the polymer-water interface compared to that of the sample with the highest FAHFiP content. Thus, by adding a small FAHFiP amount to mPEGMA copolymers, water insoluble in the bulk too, could be turned highly hydrophilic at the water interface. The high content of intermediate water contributed to their excellent bio-inert properties. Platelet adhesion and fibrinogen adsorption on their surfaces were even more decreased as compared to those on poly(2-methoxyethyl acrylate), which is typically used in medical devices.

Pharmacokinetic Approach for the Elucidation of Elevated Plasma Small Extracellular Vesicle (sEV) Concentration in Cancer.

The abundance of circulating plasma small extracellular vesicles (sEVs) has been reported to be elevated in cancer; however, the underlying mechanism remains unclear. In this study, a pharmacokinetic approach was used to determine the factors contributing to elevated plasma sEV levels during cancer in a tumor-bearing mouse model. Mouse plasma-derived sEVs (MP-sEVs) isolated from tumor-bearing mice showed increased protein concentrations and physicochemical characteristics comparable to MP-sEVs isolated from healthy mice. The steady-state concentration of sEVs is determined by the balance between the MP-sEV production and clearance. Thus, to determine whether tumorigenesis influences sEV clearance, isolated MP-sEVs were intravenously administered to either tumor-bearing or healthy mice. The results showed minimal differences in sEV clearance rates, suggesting that sEV production is the driving force of elevated MP-sEV concentrations. Lastly, CD63-gLuc stably expressing B16BL6-bearing mice were used to estimate the contribution of tumor cell-derived sEVs in the plasma. The gLuc activity of the MP-sEVs isolated was below the limit of detection, and it was estimated that the tumor cell-derived sEVs comprised at most 0.5% of the total MP-sEVs. Taken together, these results suggest that cells other than tumor cells contribute to elevated plasma sEV levels in cancer.

Simple Detection and Culture of Circulating Tumor Cells from Colorectal Cancer Patients Using Poly(2-Methoxyethyl Acrylate)-Coated Plates.

Here we aimed to establish a simple detection method for detecting circulating tumor cells (CTCs) in the blood sample of colorectal cancer (CRC) patients using poly(2-methoxyethyl acrylate) (PMEA)-coated plates. Adhesion test and spike test using CRC cell lines assured efficacy of PMEA coating. A total of 41 patients with pathological stage II-IV CRC were enrolled between January 2018 and September 2022. Blood samples were concentrated by centrifugation by the OncoQuick tube, and then incubated overnight on PMEA-coated chamber slides. The next day, cell culture and immunocytochemistry with anti-EpCAM antibody were performed. Adhesion tests revealed good attachment of CRCs to PMEA-coated plates. Spike tests indicated that ~75% of CRCs from a 10-mL blood sample were recovered on the slides. By cytological examination, CTCs were identified in 18/41 CRC cases (43.9%). In cell cultures, spheroid-like structures or tumor-cell clusters were found in 18/33 tested cases (54.5%). Overall, CTCs and/or growing circulating tumor cells were found in 23/41 CRC cases (56.0%). History of chemotherapy or radiation was significantly negatively correlated with CTC detection (p = 0.02). In summary, we successfully captured CTCs from CRC patients using the unique biomaterial PMEA. Cultured tumor cells will provide important and timely information regarding the molecular basis of CTCs.

Enrichment of Cancer Cells Based on Antibody-Free Selective Cell Adhesion.

Blood-compatible and cell-adhering polymer materials are extremely useful for regenerative medicine and disease diagnosis. (Meth)acryl polymers with high hydrophilicity have been widely used in industries, and attempts to apply these polymers in the medical field are frequently reported. We focused on crosslinked polymer films prepared using bifunctional monomers, which are widely used as coating materials, and attempted to alter the cell adhesion behavior while maintaining blood compatibility by changing the chemical structure of the crosslinker. Four bifunctional monomers were studied, three of which were found to be blood-compatible polymers and to suppress platelet adhesion. The adhesion behavior of cancer cells to polymer films varied; moreover, the cancer model cells MCF-7 [EpCAM(+)] and MDA-MB-231 [EpCAM (-)], with different expression levels of epithelial cell adhesion molecule (EpCAM), showed distinct adhesion behavior for each material. We suggest that a combination of these materials has the potential to selectively capture and enrich highly metastatic cancer cells.

The identification of novel small extracellular vesicle (sEV) production modulators using luciferase-based sEV quantification method.

Small extracellular vesicles (sEVs) are nano-sized vesicles secreted from various cells that contain bioactive metabolites and function as key regulators for intercellular communication. sEVs modulate diverse biological and pathological processes in the body, and the amount of circulating sEVs has been reported to correlate with certain disease progression. Therefore, the identification of small molecular compounds that can control sEV production may become a novel therapeutic strategy. In this study, a rapid, highly sensitive sEV quantification method utilizing fusion proteins consisting of Gaussia luciferase (gLuc) reporter protein and sEV markers (CD63 and CD82) was developed. A total of 480 compounds were screened to identify potent inducers and inhibitors of gLuc activity. Two novel compounds, KPYC08425 and KPYC12163, showed significant and dose-dependent changes in gLuc activity with minimal cytotoxicity based on the LDH assay. The efficacy of these two compounds was further evaluated by protein quantification of the isolated sEVs. Further evaluation of KPYC12163 suggested that the autolysosomal pathway may be involved in its inhibitory effect on sEV production.

Phosphatidylserine-deficient small extracellular vesicle is a major somatic cell-derived sEV subpopulation in blood.

Small extracellular vesicles (sEVs) are important mediators of intercellular communication with respect to diverse pathophysiological processes. Here, we determined novel phosphatidylserine (PS)-deficient sEV subpopulations as a major somatic cell-derived sEV subpopulation in blood because of long blood circulation half-life through escape from macrophage uptake. PS(-)-sEVs were identified in various cultured cells as a minor population. However, as a result of rapid uptake of PS(+)-sEVs by macrophages, circulating somatic cell-derived sEVs in the blood were found to be mainly PS(-)-sEVs. These results suggest that endogenous PS(-)-sEVs could indeed be the key player in sEV-mediated intercellular communication, a good target for sEV-based diagnosis, and a potent candidate for sEV-based drug delivery. Our findings bring a paradigm shift in the understanding of the biology and translational applications of sEVs.

Determining The Role of Surface Glycans in The Pharmacokinetics of Small Extracellular Vesicles.

Small extracellular vesicles (sEVs) are important mediators of intercellular communication and are thereby expected to be promising carriers for drug delivery. Understanding the factors that affect sEV pharmacokinetics is crucial for its application as a drug delivery carrier. In this study, the role of sEV surface glycans was investigated by evaluating the effects of enzymatic deglycosylation treatment on sEV pharmacokinetics. First, control glycoprotein fetuin was used to optimize the glycosidase treatment conditions. B16-BL6-derived sEVs labeled with fusion proteins comprising Gag protein and Gaussia luciferase (gLuc) (Gag-gLuc) were then treated with glycosidases, Peptide-N-Glycosidase F or O-glycosidase, which cleaves N- and O-glycans, respectively. Glycosidase-treated sEVs showed physicochemical characteristics comparable to those of the untreated sEVs. However, removal of N-glycans from B16-BL6 sEVs enhanced cellular uptake by the peritoneal macrophages, while the removal of O-glycans had minimal impact, as evaluated by flow cytometry. To determine the effect of surface glycans on the sEV pharmacokinetics, Gag-gLuc labeled B16-BL6 sEVs treated with or without glycosidases were then intravenously administered to mice. Glycosidase-treated sEVs showed almost identical clearance from the blood circulation as that of the untreated sEVs. These results suggest minimal impact of surface glycans on sEV pharmacokinetics, despites its effect on cellular uptake.

Blood concentrations of small extracellular vesicles are determined by a balance between abundant secretion and rapid clearance.

Small extracellular vesicles (sEVs) are important mediators of cell-cell communication with respect to diverse physiological processes. To further understand their physiological roles, understanding blood sEV homoeostasis in a quantitative manner is desired. In this study, we propose novel kinetic approaches to estimate the secretion and clearance of mouse plasma-derived sEVs (MP-sEVs) based on the hypothesis that blood sEV concentrations are determined by a balance between the secretion and clearance of sEVs. Using our specific and sensitive sEV labelling technology, we succeeded in analysing MP-sEV clearance from the blood after intravenous administration into mice. This revealed the rapid disappearance of MP-sEVs with a half-life of approximately 7 min. Moreover, the plasma sEV secretion rate, which is presently impossible to directly evaluate, was calculated as 18 µg/min in mice based on pharmacokinetic (PK) analysis. Next, macrophage-depleted mice were prepared as a model of disrupted sEV homoeostasis with retarded sEV clearance. MP-sEV concentrations were increased in macrophage-depleted mice, which probably reflected a shift in the balance of secretion and clearance. Moreover, the increased MP-sEV concentration in macrophage-depleted mice was successfully simulated using calculated clearance rate constant, secretion rate constant and volume of distribution, suggesting the validity of our PK approaches. These results demonstrate that blood sEV concentration homoeostasis can be explained by the dynamics of rapid secretion/clearance.

Somatosensory profile of a patient with mixed connective tissue disease and Sjögren syndrome.

BACKGROUND AND OVERVIEW: The authors report the case of a patient with mixed connective tissue disease (MCTD) and Sjögren syndrome, showing signs and symptoms of bilateral trigeminal neuropathy and aseptic meningitis. The patient was assessed by means of quantitative sensory testing (QST) according to the German Research Network on Neuropathic Pain standards, in both the gingiva and forearm, and the results were compared with those of healthy control participants. CASE DESCRIPTION: A 27-year-old woman, who had received a diagnosis of MCTD and Sjögren syndrome from a rheumatologist, sought treatment at an orofacial pain clinic for bilateral electriclike pain in the maxillary anterior gingiva, eyelids, and cheeks. QST indicated allodynia and hyperalgesia in response to mechanical and thermal stimuli in both her gingiva and forearm, and cold hyperalgesia in her forearm only. She had been prescribed an oral corticosteroid (prednisone, 7 milligrams per day) by the rheumatologist, and was given lidocaine gel and systemic pregabalin (400 mg/d) at the clinic. CONCLUSIONS AND PRACTICAL IMPLICATIONS: The cause of trigeminal neuropathy in MCTD and Sjögren syndrome (SS) is unknown. The QST data in this case showed that the somatosensory disturbance severity was higher in the gingiva than in the forearm, suggesting that the trigeminal nerve may be more susceptible than other parts of the nervous system in patients with MCTD. If reproducible in future studies, the finding of greater hypersensitivity in the gingiva than in the forearm may provide an opportunity for dentists to play a role in the detection, diagnosis, or both of MCTD and SS. Dentists must be sufficiently familiar with MCTD and SS to include them in their differential diagnoses and should consider performing simple neurosensory testing such as via intraoral cotton swab or pinprick test.

Persistent random deformation model of cells crawling on a gel surface.

In general, cells move on a substrate through extension and contraction of the cell body. Though cell movement should be explained by taking into account the effect of such shape fluctuations, past approaches to formulate cell-crawling have not sufficiently quantified the relationship between cell movement (velocity and trajectory) and shape fluctuations based on experimental data regarding actual shaping dynamics. To clarify this relationship, we experimentally characterized cell-crawling in terms of shape fluctuations, especially extension and contraction, by using an elasticity-tunable gel substrate to modulate cell shape. As a result, an amoeboid swimmer-like relation was found to arise between the cell velocity and cell-shape dynamics. To formulate this experimentally-obtained relationship between cell movement and shaping dynamics, we established a persistent random deformation (PRD) model based on equations of a deformable self-propelled particle adopting an amoeboid swimmer-like velocity-shape relationship. The PRD model successfully explains the statistical properties of velocity, trajectory and shaping dynamics of the cells including back-and-forth motion, because the velocity equation exhibits time-reverse symmetry, which is essentially different from previous models. We discuss the possible application of this model to classify the phenotype of cell migration based on the characteristic relation between movement and shaping dynamics.

Structural requirements of glycosaminoglycans for facilitating amyloid fibril formation of human serum amyloid A.

Serum amyloid A (SAA) is a precursor protein of amyloid fibrils. Given that heparan sulfate (HS), a glycosaminoglycan (GAG), is detected in amyloid deposits, it has been suggested that GAG is a key component of amyloid fibril formation. We previously reported that heparin (an analog of HS) facilitates the fibril formation of SAA, but the structural requirements remain unknown. In the present study, we investigated the structural requirements of GAGs for facilitating the amyloid fibril formation of SAA. Spectroscopic analyses using structurally diverse GAG analogs suggested that the fibril formation of SAA was facilitated irrespective of the backbone structure of GAGs; however, the facilitating effect was strongly correlated with the degree of sulfation. Microscopic analyses revealed that the morphologies of SAA aggregates were modulated by the GAGs. The HS molecule, which is less sulfated than heparin but contains highly sulfated domains, exhibited a relatively high potential to facilitate fibril formation compared to other GAGs. The length dependence of fragmented heparins on the facilitating effect suggested that a high density of sulfate groups is also required. These results indicate that not only the degree of sulfation but also the lengths of sulfated domains in GAG play important roles in fibril formation of SAA.

Trial using pig cells with the H-D antigen knocked down.

PURPOSE: This report describes an attempt to reduce the expression level of Hanganutziu-Deicher (H-D) antigens by small interfering RNA (siRNA) for pig cytidine monophospho-N-acetylneuraminic acid hydroxylase (pCMAH). METHODS: A pig endothelial cell (PEC) line, and PEC and fibroblasts from an α1,3galactosyltransferase knockout (GalT-KO) piglet were used. Real-time PCR was used to evaluate the degradation of mRNA by siRNA. The H-D antigen was stained, and then the cells were incubated with human serum for the FACS analysis. The extent of lysis in human serum was next calculated using an LDH assay. RESULTS: Suppression of the mRNA of pCMAH by each siRNA was first determined. The mixture of siRNAs for pCMAH reduced the expressions of the H-D antigen on the PEC and fibroblasts to a considerable extent. The further reduction in the xenoantigenicity for human serum of the GalT-KO cells was then confirmed. In addition, the PEC line showed a significant downregulation in complement-dependent cytotoxicity by the siRNAs, thus indicating that the anti-H-D antigen in human serum is capable of causing lysis of the pig cells. CONCLUSION: pCMAH silencing by siRNA reduced the expression of the H-D antigen and its antigenicity, thus confirming that the H-D antigen is one of the major non-Gal antigens in this situation.

Effects of a calcineurin inhibitor, FK506, and a CCR5/CXCR3 antagonist, TAK-779, in a rat small intestinal transplantation model.

The effects of FK506, and TAK-779, antagonists of CCR5 and CXCR3, were investigated using a rat intestinal transplantation model. Small intestines from DA rats were heterotopically transplanted into LEW rats. The recipients were treated with FK506 (1mg/kg/day, day 0-5) and TAK-779 (10mg/kg/day, day 0-10). Graft survival and immunological responses to these materials were estimated by mixed lymphocyte reactions and IFN-γ production. The expression of chemokine receptors on lymphocytes was also examined. The average duration of survival was 7.0±0.3, 12.0±1.0, 9.8±0.5 and 18.0±1.5days in the allogeneic, FK506, TAK-779 and the two-drug combined groups, respectively. Cell proliferative responses and IFN-γ production were suppressed to a significant extent in the FK506 group compared with the TAK-779 group. In addition, the two-drug combination showed a tendency for stronger suppression than FK506 alone, correlated with in vivo and histopathological data. The numbers of both CD4(+) and CD8(+) cells were significantly suppressed in the blood of the recipients of both the FK506 and the TAK-779 groups, and in Peyer's patches of the graft of the TAK-779 group, but the FK506 group was not, as evidenced by FACS analysis. In addition, double-staining of graft-infiltrating lymphocytes showed a significant reduction in lymphocyte numbers, expressing CCR5 and CXCR3 in the TAK-779 group, but not evident in the FK506 group, compared to the allogeneic group. While FK506 suppresses cell proliferation and effecter function, it has less effect on the expression of CCR5 and CXCR3 in lymphocytes. Further exploration of the effects of a combined therapy with TAK-779 could represent a novel treatment for intestinal transplantation.

Expression of complement regulatory protein on porcine endogenous retrovirus (PERV) depends on molecular size.

Expression of complement regulatory proteins (CRP) on pig cells is an effective means to avoid hyperacute rejection. However, pig endogenous retrovirus (PERV) from pig cells transfected with CRP may acquire resistance to human serum (HS). The present study investigated the size limitations of the transfected CRP that can be easily expressed and function on PERV particles. cDNAs of various sized DAF(CD55)s, including single-, double-, triple-, tetra-, as well as 2.1- and 2.2-DAF, were prepared. Pig endothelial cells (PEC) were transduced with the LacZ gene, and were then infected with PERV-B to produce PEC(Z)/PB. The extent of complement-mediated lysis by the transfectant molecules on PEC(Z)/PB was then determined. HEK293 cells were incubated with PEC(Z)/PB culture supernatants in the presence of HS and the LacZ pseudo-type assay was then carried out. Amelioration of complement-mediated lysis by the hybrid molecules was verified in each PEC(Z)/PB clone. All molecules appeared to effectively protect xenogeneic cells against complement-mediated lysis. While PERVs from the PEC(Z)/PB with both the single-DAF and double-DAF were resistant to HS, PERVs from the triple-DAF and tetra-DAF showed no significant increase in resistance. In addition, the PERVs from PEC(Z)/PB with 2.1-DAF and 2.2-DAF were less resistant than PEC with double-DAF. Resistance to HS was steadily attenuated with increasing size of the DAF molecule. The resistance to HS was disappeared by the anti-DAF blocking mAb, indicating that PERVs from the transfectants express DAF molecules on the surface of the PERV. The data clearly indicate that, to avoid the induction of resistance to HS in PERV particles, relatively large CRPs, such as triple-DAF and tetra-DAF or DAF with other large molecules, should be employed in the production of transgenic pigs.

Complement regulation in the GalT KO era.

A number of institutes have reported on the successful production of alpha-galactosyltransferase knockout (GalT-KO) pigs. After producing such pigs, hyperacute rejection appeared to no longer be a problem. However, acute vascular rejection (AVR)/acute humoral xenograft rejection (AHXR) is defined as a rejection that begins within 24 h after transplantation and gradually destroys the graft. The origin of AVR/AHXR continues to be a controversial topic, but is generally thought to be initiated by xeno-reactive antibodies, including non-Gal antibodies and subsequent activation of the graft endothelium, the complement and the coagulation systems. The complement is activated via the classical pathway by non-Gal antigens and ischemia-reperfusion injury, via the alternative pathway, especially on islets, and via the lectin pathway. Therefore the complement system is still an important recognition and effector mechanism of AVR/AHXR. In addition, quite recently, based on the relationship between complement and coagulation systems, a new pathway has been proposed. All complement regulatory proteins (CRPs) have the ability to regulate complement activation in different ways. Therefore, to effectively protect xenografts against AVR/AHXR, it appears reasonable to employ not only one but several CRPs including anti-complement drugs. Non-Gal antigens, such as the Hanganutziu-Deicher antigen, is still present on GalT-KO grafts. The further assessment of antigens continues to be an important issue in the area of clinical xenotransplantation. The above conclusions suggest that the expression of human CRPs on GalT-KO grafts is necessary. Moreover, multilateral inhibition of complement activation is required in conjunction with the regulation of the coagulation system.

Survey of glycoantigens in cells from alpha1-3galactosyltransferase knockout pig using a lectin microarray.

BACKGROUND: Glycoantigens represent major obstacles to successful xenotransplantation. Even after the alpha1-3galactosyltransferase (GalT) gene knockout (GalT-KO) pigs were produced, non-Gal antigens continue to be present. This study reports on lectin blot analyses for endothelial cells (EC) and fibroblasts from GalT-KO pigs. METHODS: Differences in glycoantigens that are produced on cell surfaces in humans and pigs were surveyed. Differences between ECs and fibroblasts from wild-type and GalT-KO pigs were also examined. EC and fibroblasts from GalT-KO pigs (heterozygous and homozygous) with N-acetylglucosaminyltransferase-III (GnT-III), a wild-type EC from the sibling, human EC lines, HUVEC (human EC from umbilical veins), & HAOEC (human EC from aortas), and human fibroblast line were used. EC and fibroblasts were cultured in gelatin-coated dishes for several days. After sonication and centrifugation, the supernatant protein from each cell was labeled with Cy3, applied to a lectin array and scanned with an SC Profiler, and analyzed using an Array Pro Analyzer. RESULTS: The pig EC showed higher signals in Euonymus Europaeus (EEL) & Griffonia simplicifolia I-B(4) (GSI-B4), binds alpha-Gal, and in Wisteria Floribunda (WFA), Helix pomatia (HPA), Glycine max (SBA), & Griffonia simplicifolia I-A(4) (GSI-A4), binds GalNAc including the Thomsen-Friedenreich precursor (Tn)-antigen, while the human EC showed strong signals in Ulex europaeus I (UEA-I), Maackia amurensis (MAL), Erythrina cristagalli (ECA), & Trichosanthes japonica I (TJA-I) instead. The EC from the GalT-KO pig signals for EEL & GSI-B4 disappeared and those for Bauhinia purpurea alba (BPL), HPA, SBA, & GSI-A4 were greatly diminished as well, while it up-regulated signals for Sambucus Nigra (SNA), Sambucus sieboldiana (SSA), & TJA-I, bind alpha2-6 sialic acid, compared to the wild-type pig EC. Concerning fibroblasts, the signals for HPA, SBA, & GSI-A4 were the most intense in the wild-type, and the intensities for homozygous-KO were less, approaching those of humans. In addition, the order of the intensities, as detected by Arachis hypogaea (PNA) & Maclura pomifera (MPA), binding Galbeta1-2GalNAc, indicates that the Thomsen-Friedenreich (T)-antigen is likely present on pig fibroblasts. CONCLUSION: It is possible that the T-antigen and Tn-antigen related to GalNAc are non-Gal antigens, but, fortunately, not only alpha-Gal but also GalNAc were found to be decreased in the KO-pig.

A newly cloned pig dolichyl-phosphate mannosyl-transferase for preventing the transmission of porcine endogenous retrovirus to human cells.

Porcine endogenous retrovirus (PERV) is a major problem associated with successful clinical xenotransplantation. In our previous study, reducing the high mannose type of N-glycan content proved to be very effective in downregulating PERV infectivity. In this study, dolichyl-phosphate mannosyltransferase (D-P-M), an enzyme related to the early stages of N-linked sugar synthesis was studied. The pig cDNA of the encoding D-P-M was newly isolated. The RNA interference (siRNA) for the D-P-M was applied and transfected to PEC(Z)/PB cells, a pig endothelial cell line with the Lac Z gene and PERV-B, to reduce the levels of high mannose type N-glycans. Compared with the mock line, the temporary PEC(Z)/PB lines showed a decreased mRNA expression for pig D-P-M, and each line then showed a clear destruction of PERV infectivity to human cells in the Lac Z pseudotype assay. The PEC(Z)/PB was next transfected with pSXGH-siRNA, H1-RNA gene promoter. The established PEC(Z)/PB clones with pSXGH-siRNA clearly led to the downregulation of PERV infectivity, as evidenced by the decreased levels of the mRNA for pig D-P-M. Reducing D-P-M enzyme activity represents a potentially useful approach to address the problem of PERV infections in clinical xenotransplantations.

Comparison of three measurement techniques for the normal absorption coefficient of sound absorbing materials in the free field.

Three different techniques for evaluating the absorption coefficient of sound absorbing materials in free field conditions are discussed. One technique measures the acoustic impedance at one point nearby a specimen, the other two techniques evaluate the impedance from the transfer function of two sound pressures and two particle velocities at two points. These are called "PU-method," "PP-method," and "UU-method," respectively. An iterative algorithm to estimate the acoustic impedance of the locally reactive specimen in the spherical wave field is also applied. First, the effect of receiver positions, specimen areas, and source heights to the measured normal absorption coefficient is investigated by the boundary element method. According to these investigations, the PU-method is most stable against the effect of specimen area, and the UU-method is easily affected by that effect. Closer source to the specimen distance is advantageous for the signal to noise ratio of these measurement techniques, but correction for the effect of the spherical wave field has to be applied. As a finding, the iterative algorithm works for all of three techniques. Finally, the PU-method is applied experimentally with a pressure-velocity sensor and a loudspeaker in a hemi-anechoic room. As a result, the calculated results have been verified.

Responses of hypothalamo-pituitary-adrenal axis to a cholinesterase inhibitor.

Acute gastrointestinal events (mostly manifested by nausea, vomiting, or loss of appetite) are class effects of all cholinesterase inhibitors, which are prescribed for the treatment of Alzheimer's disease. The underlying mechanism, however, has been unclear. Because corticotropin-releasing hormone is related to appetite control, we focused on the activation of the hypothalamo-pituitary-adrenal system and food intake following the administration of the cholinesterase inhibitor, donepezil, in rats. We monitored the plasma concentrations of adrenocorticotropic hormone, c-Fos, in the paraventricular nucleus, and intakes of rat chow for 3 h after the first administration of donepezil, and 2 weeks later, after daily administration of donepezil. The intragastric administration of 3 mg/kg of donepezil significantly increased the plasma adrenocorticotropic hormone levels and c-Fos expression in the paraventricular nucleus, and decreased the food intake on the first day. The increase in adrenocorticotropic hormone and loss of appetite after oral administration of the drug were attenuated after daily administration for 2 weeks.