Effect of Vesicle Size on the Cytolysis of Cell-Penetrating Peptides (CPPs)

A specific series of peptides, called a cell-penetrating peptide (CPP), is known to be free to directly permeate through cell membranes into the cytosol (cytolysis); hence, this CPP would be a potent carrier for a drug delivery system (DDS). Previously, we proposed the mechanism of cytolysis as a temporal and local phase transfer of membrane lipid caused by positive membrane curvature generation. Moreover, we showed how to control the CPP cytolysis. Here, we investigate the phospholipid vesicle's size effect on CPP cytolysis because this is the most straightforward way to control membrane curvature. Contrary to our expectation, we found that the smaller the vesicle diameter (meaning a higher membrane curvature), the more cytolysis was suppressed. Such controversial findings led us to seek the reason for the unexpected results, and we ended up finding out that the mobility of membrane lipids as a liquid crystal is the key to cytolysis. As a result, we could explain the cause of cytolysis suppression by reducing the vesicle size (because of the restriction of lipid mobility); osmotic pressure reduction to enhance positive curvature generation works as long as the membrane is mobile enough to modulate the local structure. Taking all the revealed vital factors and their effects as a tool, we will further explore how to control CPP cytolysis for developing a DDS system combined with appropriate cargo selection to be tagged with CPPs.

Glycaemic control boosts glucosylated nanocarrier crossing the BBB into the brain

Recently, nanocarriers that transport bioactive substances to a target site in the body have attracted considerable attention and undergone rapid progression in terms of the state of the art. However, few nanocarriers can enter the brain via a systemic route through the blood-brain barrier (BBB) to efficiently reach neurons. Here we prepare a self-assembled supramolecular nanocarrier with a surface featuring properly configured glucose. The BBB crossing and brain accumulation of this nanocarrier are boosted by the rapid glycaemic increase after fasting and by the putative phenomenon of the highly expressed glucose transporter-1 (GLUT1) in brain capillary endothelial cells migrating from the luminal to the abluminal plasma membrane. The precisely controlled glucose density on the surface of the nanocarrier enables the regulation of its distribution within the brain, and thus is successfully optimized to increase the number of nanocarriers accumulating in neurons.There are only a few examples of nanocarriers that can transport bioactive substances across the blood-brain barrier. Here the authors show that by rapid glycaemic increase the accumulation of a glucosylated nanocarrier in the brain can be controlled.

Orbital Glass State of the Nearly Metallic Spinel Cobalt Vanadate

Strain, magnetization, dielectric relaxation, and unpolarized and polarized neutron diffraction measurements were performed to study the magnetic and structural properties of spinel Co_{1-x}V_{2+x}O_{4}. The strain measurement indicates that, upon cooling, ΔL/L in the order of ∼10^{-4} starts increasing below T_{C}, becomes maximum at T_{max}, and then decreases and changes its sign at T^{*}. Neutron measurements indicate that a collinear ferrimagnetic order develops below T_{C} and upon further cooling noncollinear ferrimagnetic ordering occurs below T_{max}. At low temperatures, the dielectric constant exhibits a frequency dependence, indicating slow dynamics. These results indicate the existence of an orbital glassy state at low temperatures in this nearly metallic frustrated magnet.

Trapping and isolation of single prokaryotic cells in a micro-chamber array using dielectrophoresis

The vast majority of prokaryotic species are difficult or impossible to culture in laboratories, which makes it difficult to study these organisms using conventional biochemical techniques.

On-site measurement of trace-level sulfide in natural waters by vapor generation and microchannel collection

Aqueous sulfide plays an important role in the environment even at low concentrations. However, it is unstable, which means field samples cannot be transported to the laboratory for analysis without fixation. In this work, a novel method was developed to determine trace levels of sulfide on site. This method is based on vapor generation and collection in a special microchannel device followed by fluorescence measurement (VG-μGAS). The microchannel scrubber gave a high enrichment factor, and a high sensitivity was achieved, which allowed measurement of nanomolar (nM) levels of sulfide. The theoretical approach to vapor generation for several compounds is discussed to evaluate the applicability of the method to these analytes, and compounds having a low Henry's law constant (<1 M atm(-1)) are suitable to measure by VG-μGAS. Under optimized conditions, concentrations of 1.0-100 nM of sulfide could be measured. The sulfide contents of hot spring, aquarium, pond, and seawater were successfully measured by this method. Nanomolar levels of sulfide could be measured on site without loss of analyte, and results were obtained instantly in the field, both of which are advantageous for effective field surveys. The method was also applied to field measurements of aqueous sulfide in the Ariake Sea and Lake Baikal.

Phase Diagram and Anisotropic Transport Properties of Nd1-xSrxMnO3 Crystals

We have investigated electronic transport and magnetic properties of perovskite-type Nd1-xSrxMnO3 crystals with change of controlled hole-doping level (0.30≤x≤0.80). The electronic phase diagram of Nd1-xSrxMnO3 was obtained by systematic measurements of magnetization (magnetic structure), resistivity, and lattice parameter. We have also studied the anisotropie transport properties of x=0.50 and 0.55 crystals with different magnetic structures: CE-type antiferromagnetic (AF) structure for x=0.50 and A-type layered AF one for x=0.55. In the case of the x=0.55 crystal, the metallic behavior was observed within the ferromagnetic (F) layers, while along the AF-coupling direction the crystal remains insulating over the whole temperature region. The observed large anisotropy is due to the magnetic as well as orbital-ordering induced confinement of the spin-polarized carriers within the F sheets. The nearly isotropie transport behavior has been confirmed for the CE-type AF charge-ordered state in the x=0.50 crystal.

Development of high-speed polarizing imaging system for operation in high pulsed magnetic field

A high-speed polarizing microscope system combined with a 37 T pulse magnet has been developed. This system was applied to successfully visualize the field-induced collapse of charge-orbital ordering in a layered manganite La(1/2)Sr(3/2)MnO(4). Quantitative analyses of the obtained polarizing microscope images provided clear evidence of this transition in contrast to rather moderate changes in magnetization and magnetoresistance. The ability of this system to carry out quantitative analysis was further tested through the observation of Faraday rotation in a Tb(3)Ga(5)O(12) crystal. The Verdet constant determined from the polarizing images is in reasonable agreement with that in literature. Local intensity analyses of the images indicate that we can investigate magneto-optical signals within an accuracy of 0.85% in an area of 9.6 x 9.6 microm(2).

Adenovirus-mediated gene delivery of interleukin-10, but not transforming growth factor beta, ameliorates the induction of Graves' hyperthyroidism in BALB/c mice

Interleukin-10 (IL-10) and transforming growth factor-beta (TGF-beta) are well known anti-inflammatory cytokines. We have studied the effect of adenovirus-mediated IL-10 and TGF-beta gene delivery on the induction of Graves' hyperthyroidism in our mouse model that involves repeated injections of adenovirus expressing the thyrotropin receptor A subunit (AdTSHR). We first constructed adenoviruses encoding the two cytokines (AdIL10 and AdTGF(beta)) and confirmed expression by in vitro infection of COS cells. Susceptible BALB/c mice were injected twice with AdTSHR alone or together with AdIL10 or AdTGF(beta), and bled two weeks after the second immunization. Significantly elevated serum thyroxine levels were seen in 26% of mice immunized with AdTSHR and AdIL10 versus 61% with AdTSHR alone. Levels of thyroid stimulating antibody, but not nonstimulating antibody, were also decreased, and TSHR-specific splenocyte secretion of interferon-gamma in recall assays was impaired in mice treated with AdIL10. In contrast, AdTGF(beta) had little effect on hyperthyroidism. Overall, our findings demonstrate that gene delivery of IL-10, but not TGF-beta, suppresses the induction of Graves' hyperthyroidism in a mouse model. However, the effect of IL-10 is less powerful than we observed previously with T helper type 2-inducers including adenovirus expressing IL-4, Shistosoma mansoni infection or alpha-galactosylceramide.

Acute effects of ethanol on feeding behavior and leptin-induced STAT3 phosphorylation in rat hypothalamus

OBJECTIVE

Drinking ethanol stimulates the appetite, producing a positive energy balance. The mechanism by which ethanol regulates the appetite in the central nervous system, however, has not been fully understood. The aim of this study is to investigate the interaction of ethanol with the satiety effect of leptin, a hormone which suppresses the appetite in the hypothalamic region.

DESIGN

: Leptin (7.5 micro g) or the same dose of phosphate buffer saline (PBS) was administered into the third ventricle (i.c.v.), 30 min after an intraperitoneal injection (i.p.) of ethanol (0.5 g/kg body weight) or the same dose of PBS.

MATERIALS

Adult male Sprague-Dawley rats weighing 290-320 g were used.

MEASUREMENTS

Food intake was measured 2, 12 and 24 h after leptin i.c.v. infusion. The tyrosine phosphorylation of signal transducer and activator transcription factor 3 (STAT3) in the hypothalamus was analyzed by Western blotting.

RESULTS

The cumulative food intakes in the saline/leptin group (saline i.p.+leptin i.c.v.) were markedly reduced to about 45% of the saline/PBS group (saline i.p.+PBS i.c.v.) at 2, 12 and 24 h time points (P<0.05, 0.001, and 0.005, respectively). As compared with the saline/leptin group, those of the ethanol/leptin group (ethanol i.p.+leptin i.c.v.) were significantly increased to the level seen in the saline/PBS group at 12 and 24 h time points (P<0.05, and P<0.005 vs the saline/leptin group, respectively). Ethanol administration resulted in about a 50% reduction of the leptin-induced STAT3 tyrosine phosphorylation seen in the hypothalamic protein as compared to that of the saline/leptin group.

CONCLUSION

These findings suggest that ethanol-induced enhancement of the appetite may, in part, result from leptin resistance transiently caused by ethanol to attenuate the leptin signal transduction.

Decrease in the insulin receptor protein level by anti-insulin receptor antibodies: roles of tyrosine kinase activity and receptor internalization

To investigate the mechanism of severe impairment of insulin action in type B insulin resistance, we extracted IgG from the serum of a patient with type B insulin resistance (B-IgG) and analyzed the inhibiting effect of B-IgG not only on insulin signaling but also on IGF-I signaling in Chinese hamster ovary (CHO) cells expressing human insulin receptor or human IGF-I receptor. Preincubation with 1 mg/ml B-IgG prevented insulin-induced phosphorylation of insulin receptor and insulin receptor substrate-1 (IRS-1) but did not alter the IGF-I-induced phosphorylation of the IGF-I receptor and IRS-1. (125)I-insulin binding was inhibited by 93% after preincubation with B-IgG at 37 degrees C and was recovered up to 50% of the control value by acid washing. However, when cells were preincubated with B-IgG at 4 degrees C, the insulin binding completely recovered the control value by acid washing. (125)I-IGF-I binding was not altered by B-IgG preincubation. Immunoblot study revealed that the protein level of the insulin receptor was strongly decreased by preincubation with 1 mg/ml B-IgG at 37 degrees C, but never at 4 degrees C. The IRS-1 protein level did not change by B-IgG preincubation. In order to know the role of the insulin receptor internalization in the inhibiting effect of B-IgG, we employed CHO cells expressing mutant insulin receptors which do not undergo internalization (CHO-K1018R). B-IgG incubation of CHO-K1018R at 37 degrees C failed to decrease the protein level of the insulin receptor. The present data indicate that IgG from the diabetic patient with type B insulin resistance decreased insulin receptor protein level, probably due to the enhanced degradation rate of the insulin receptor, in which insulin receptor tyrosine kinase activity and internalization are required for this process. This effect of B-IgG was specific for the insulin receptor with no effect on either IGF-I receptor or IRS-1, as reflected by the IGF-I effectiveness on glycemic control in this patient.

Ferromagnetic domain structures and nanoclusters in Nd(1/2)Sr(1/2)MnO3

Magnetic domain structures of Nd(1/2)Sr(1/2)MnO3 were investigated by means of low-temperature Lorentz electron microscopy. On cooling, magnetic domain walls started to appear at 250 K, and they were oriented straight along the [100] and [110] directions. With a further decrease in temperature, the volume of each magnetic domain increased with discontinuous domain-wall jumps. A characteristic granular image was observed at around 140 K, near the charge-ordering transition temperature. We consider that this originated from ferromagnetic nanoclusters that appeared in the antiferromagnetic matrix.

The epidermal growth factor receptor regulates interaction of the human DF3/MUC1 carcinoma antigen with c-Src and beta-catenin

The DF3/MUC1 mucin-like, transmembrane glycoprotein is aberrantly overexpressed in most human carcinomas. The MUC1 cytoplasmic domain interacts with the c-Src tyrosine kinase and thereby increases binding of MUC1 and beta-catenin. In the present work, coimmunoprecipitation studies demonstrate that MUC1 associates constitutively with the epidermal growth factor receptor (EGF-R) in human ZR-75-1 breast carcinoma cells. Immunofluorescence studies show that EGF-R and MUC1 associate at the cell membrane. We also show that the activated EGF-R phosphorylates the MUC1 cytoplasmic tail on tyrosine at a YEKV motif that functions as a binding site for the c-Src SH2 domain. The results demonstrate that EGF-R-mediated phosphorylation of MUC1 induces binding of MUC1 to c-Src in cells. Moreover, in vitro and in vivo studies demonstrate that EGF-R increases binding of MUC1 and beta-catenin. These findings support a novel role for EGF-R in regulating interactions of MUC1 with c-Src and beta-catenin.

Nonlinear magneto-optical properties of colossal magnetoresistive manganites

Pr(1--x)CaxMnO(3) and Nd(1--x)SrxMnO(3) were investigated with three-photon difference frequency generation (DFG). This method allows one to determine both the crystalline and the magnetic symmetry. In the highly ordered low-temperature phase of Nd(0.50)Sr(0.50)MnO(3), a DFG contribution coupling simultaneously to antiferromagnetic and charge ordering was observed and used to reveal the formation of domains. Thus, magnetically induced three-photon processes are introduced into the fields of both nonlinear magneto-optics and colossal magnetoresistance as a powerful new method.

Therapeutic Effect of Novel Anti-Human Fas Antibody HFE7A on Graft-versus-Host Disease Model

In order to evaluate anti-human Fas antibody, we have established a new graft-versus-host disease (GVHD) model wherein splenocytes of human Fas transgenic mice (hFas-TgM) were transferred to immune-deficient SCID mice. In this model, although host SCID cells are not activated by or responsive to graft hFas-TgM cells, graft hFas-TgM cells are activated by and responsive to host SCID cells and thus cause GVHD symptoms. SCID mice that received hFas-TgM splenocytes had increased human Fas-positive lymphocytes in lymph nodes, decreased in body weight, and developed skin diseases, including rash and alopecia. Administration of novel anti-human Fas antibody HFE7A, which did not induce liver toxicity after administration to mice, decreased the level of the human Fas-positive lymphocytes, blocked the decrease of body weight, and suppressed development of skin diseases in this model. These results indicate that induction of apoptosis to activated graft cells with nontoxic anti-Fas antibody could reduce GVHD symptoms.

Examination of accuracy of sleep stages by means of an automatic sleep analysis system 'Sleep Ukiha'

We examined the differences between the results of an automatic sleep analysis system and inspection decision. Subjects were 10 males (average age 21.6 years). One section consists of 20 s records. The sections that deviated from the algorithm could not be decided. Each sleep stage decided by automatic analysis was compared with the inspection decision. The agreement ratio of stage 3 was 91.6% in the highest, and followed by stage 2, stage 4, stage W and stage 1. The lowest was 62.5% for movement time. The total agreement ratio was 85.8%. The agreement ratios of the apnea index (AI) and the apnea hypopnea index (AHI) were relatively high, but for types of sleep apnea, agreement ratios require improvement.

Hair follicle nevus occurring in frontonasal dysplasia: an electron microscopic observation

We report a rare hair follicle nevus that occurred in a three-month-old Japanese boy with mild frontonasal dysplasia. It had been present since birth. Histologically, numerous tiny vellus hair follicles were found within the dermis. The constituent cells of these follicles showed the features of follicular germ cells under the electron microscope. The fibroblasts around the follicles were active and merged with the colloid substance. Many myofibroblasts were found in a collagenous stroma in the atrophic lesion of the frontonasal dysplasia.

Study on withdrawal of hypnotics: questionnaire on hypnotic use and its withdrawal

To investigate the situation and problems contingent to hypnotic use and withdrawal, we conducted a questionnaire of outpatients. Only 41% of the patients were satisfied with their sleep and 53% of the patients took hypnotics. As regards the period, 83% of users had used them for more than 1 year and 19% had used them for more than 10 years. Although 90% of patients perceived efficacy of hypnotics, 67% felt more or less anxious about hypnotic use. Sixty-seven per cent of patients had actually withdrawn from the drugs or decreased dosage before. More than half the patients' conditions worsened after the withdrawal or reducing dosage.

Therapeutic effect of anti-Fas antibody on a collagen induced arthritis model

OBJECTIVE

To investigate the therapeutic effect of anti-Fas monoclonal antibody (Mab, RK-8) in collagen induced arthritis (CIA).

METHODS

CD1F1 mice were immunized with bovine type II collagen to induce CIA and were treated with RK-8 intravenously. The effect of RK-8 was monitored by visual scoring. ELISA to detect serum anti-type II collagen antibody was performed on Day 47 and 70. Histopathological analysis was performed on Days 31 and 72. Digital micrography was performed on Day 72.

RESULTS

RK-8 treatment almost completely prevented CIA. This suppressive effect continued after RK-8 was discontinued. RK-8 significantly suppressed the serum anti-type II collagen antibody level on Day 47. Histological analysis revealed that RK-8 significantly reduced joint histopathology, as determined by the infiltration of inflammatory cells and cartilage damage, consistent with digital micrography.

CONCLUSION

Administration of anti-Fas Mab may be a useful therapeutic strategy for rheumatoid arthritis if used early in the disease.

The c-Src tyrosine kinase regulates signaling of the human DF3/MUC1 carcinoma-associated antigen with GSK3 beta and beta-catenin

The DF3/MUC1 mucin-like glycoprotein is aberrantly overexpressed in most human carcinomas. The cytoplasmic domain of MUC1 interacts with glycogen synthase kinase 3 beta (GSK3 beta) and thereby decreases binding of MUC1 and beta-catenin. The present studies demonstrate that MUC1 associates with the c-Src tyrosine kinase. c-Src phosphorylates the MUC1 cytoplasmic domain at a YEKV motif located between sites involved in interactions with GSK3 beta and beta-catenin. The results demonstrate that the c-Src SH2 domain binds directly to pYEKV and inhibits the interaction between MUC1 and GSK3 beta. Moreover and in contrast to GSK3 beta, in vitro and in vivo studies demonstrate that c-Src-mediated phosphorylation of MUC1 increases binding of MUC1 and beta-catenin. The findings support a novel role for c-Src in regulating interactions of MUC1 with GSK3 beta and beta-catenin.

[Ganglioneuroma detected in a patient over age 60]

We report a case of ganglioneuroma in a 67-year-old woman who presented with an abnormal shadow at a medical examination. She was admitted and chest radiography disclosed a mass in the upper right mediastinum. We suspected a mediastinal tumor after chest CT, chest MRI and bronchofiberscopic examination, and so surgical treatment was performed. The histopathological diagnosis was ganglioneuroma. Ganglioneuroma is thought of as a children's disease and adult onset is rare. We reasoned that ganglioneuroma should be included among the mediastinal tumors in patients over 60.

[Results of questionnaire on open disclosure to patients with malignant lung tumors comparison of responses before and after chemotherapy]

To investigate patient attitudes towards open disclosure of malignant disease, we conducted a questionnaire survey of 17 patients with malignant lung tumors, to whom the nature of their disease was revealed. The questionnaire used a 100 mm analog scale. Ten of the patients were treated by chemotherapy and their questionnaire results before and after treatment were compared. It was found that they were mostly satisfied about being truthfully informed and that, indeed, they were anxious to know their true diagnoses. They were also keen to have their true prognosis revealed, but not as much as the diagnosis. They also wished to be informed about treatment and its effects. These attitudes showed no marked changes resulting from the administration of chemotherapy, and we therefore concluded that chemotherapy itself had no influence on patients' feelings about disclosure. The questionnaire was well accepted and was useful in judging attitudes to open disclosure.

Sub-populations of melanocytes in pigmented basal cell carcinoma: a quantitative, ultrastructural investigation

BACKGROUND

Pigmentation is a characteristic clinical feature of basal cell carcinomas (BCCs) in Japanese patients. The pathogenesis of melanin pigment in pigmented BCCs is poorly understood.

METHODS

We have combined the techniques of morphometric analysis and electron microscopy to assess accurately the morphologic aspects of melanocytes that occurred in pigmented and non-pigmented areas of pigmented BCCs.

RESULTS

In the pigmented areas melanocytes were not only located along the basal membrane but also interspersed between tumor cells in the central parts of the tumor nest, and had large and numerous dendrites. Those in a supra-basal location displayed some degree of degeneration due to mitochondrion and melanosome swelling. In the non-pigmented areas melanocytes were only basally located, showed fewer dendrites, and frequently showed abortive melanosomes. However, melanocytes in these two different portions were in the active state of melanogenesis and proliferation. Ultrastructural cytomorphometric analysis also showed significant differences in most of the nuclear and cell parameters including nuclear and cell area, the nuclear/cell area ratio, cell perimeter and cell form factor between these two types of melanocytes. Particularly melanocytes in the pigmented areas were twice the cell size of the latter. In addition, the melanosomes remained almost completely in the apoptotic tumor cells, and the phagocytosis of the melanosome-containing apoptotic cells by the neighboring tumor cells appeared to be followed by the formation of the melanosome complexes.

CONCLUSIONS

These findings suggest that different populations of melanocytes are probably present in pigmented BCCs, and repeated cycles of phagocytosis of melanosome-containing apoptotic cells may represent the predominant way of forming large melanosome complexes. The present morphological observation and quantitative analysis provide a morphological basis for further studies to interpret other pathologic changes in pigmented BCCs.

Transfer of platelet-derived growth factor-BB gene by gene gun increases contraction of collagen lattice by fibroblasts in diabetic and non-diabetic human skin

We have used an in vitro model of wound contraction, the fibroblast-populated collagen lattice, to examine the effect of platelet-derived growth factor BB (PDGF-BB) and PDGF-BB gene transfer by gene gun on the contraction of lattices composed of either diabetic or non-diabetic human fibroblasts. The area of collagen lattice and DNA synthesis were measured in 12 specimens. There were significant increases in lattice contraction with increasing doses of PDGF-BB and fibroblasts transfected with the PDGF-BB gene compared with control (p < 0.01). DNA synthesis of the non-diabetic and diabetic fibroblast lattices showed significantly increased incorporation of tritiated thymidine with increasing doses of PDGF-BB and fibroblasts transfected with the PDGF-BB compared with controls (p < 0.05). The effect of PDGF-BB gene transfer on diabetic and non-diabetic fibroblasts was similar to that of 20 ng/ml or less of PDGF-BB.

Intraarticular osteoid osteoma associated with synovitis: a possible role of cyclooxygenase-2 expression by osteoblasts in the nidus

To clarify the condition of development of synovitis associated with intraarticular osteoid osteoma (OO), expressions of cyclooxygenase-2 (COX-2) protein and its messenger ribonucleic acid were investigated both in the nidus and the synovial tissue using immunohistochemical and reverse transcription-polymerase chain reaction analyses. Diffuse and strong COX-2 immunoreactivity was found in osteoblast-like tumor cells in the nidus of all six cases of OO (three of six cases were intraarticular OO associated with synovitis) and one case of osteoblastoma associated with synovitis. Expression of COX-2 messenger ribonucleic acid was demonstrated in one case of OO associated with synovitis, and was higher in the nidus than that in the inflamed synovial tissue. However, there were no significant difference between the nidus and synovium in the expression of cytosolic phospholipase A2, one of the enzymes involved in arachidonic acid metabolism, and inflammatory cytokines such as interleukin-1beta and tumor necrosis factor alpha. Finally, as there was only one case in which the examinations of gene expression were performed, no definitive overall conclusions could be reached; rather it is suggested that COX-2 expressed primarily by osteoblasts in the nidus of intraarticular OO may play a role in activating the pathway of arachidonic acid metabolism, resulting in synovitis of the involved joint.

Helicobacter pylori urease suppresses bactericidal activity of peroxynitrite via carbon dioxide production

Helicobacter pylori can produce a persistent infection in the human stomach, where chronic and active inflammation, including the infiltration of phagocytes such as neutrophils and monocytes, is induced. H. pylori may have a defense system against the antimicrobial actions of phagocytes. We studied the defense mechanism of H. pylori against host-derived peroxynitrite (ONOO(-)), a bactericidal metabolite of nitric oxide, focusing on the role of H. pylori urease, which produces CO(2) and NH(3) from urea and is known to be an essential factor for colonization. The viability of H. pylori decreased in a time-dependent manner with continuous exposure to 1 microM ONOO(-), i.e., 0.2% of the initial bacteria remained after a 5-min treatment without urea. The bactericidal action of ONOO(-) against H. pylori was significantly attenuated by the addition of 10 mM urea, the substrate for urease, whereas ONOO(-)-induced killing of a urease-deficient mutant of H. pylori or Campylobacter jejuni, another microaerophilic bacterium lacking urease, was not affected by the addition of urea. Such a protective effect of urea was potentiated by supplementation with exogenous urease, and it was almost completely nullified by 10 microM flurofamide, a specific inhibitor of urease. The bactericidal action of ONOO(-) was also suppressed by the addition of 20 mM NaHCO(3) but not by the addition of 20 mM NH(3). In addition, the nitration of L-tyrosine of H. pylori after treatment with ONOO(-) was significantly reduced by the addition of urea or NaHCO(3), as assessed by high-performance liquid chromatography with electrochemical detection. These results suggest that H. pylori-associated urease functions to produce a potent ONOO(-) scavenger, CO(2)/HCO(3)(-), that defends the bacteria from ONOO(-) cytotoxicity. The protective effect of urease may thus facilitate sustained bacterial colonization in the infected gastric mucosa.

Effects of chemical modification of carboxyl groups in the hemolytic lectin CEL-III on its hemolytic and carbohydrate-binding activities

Effects of chemical modification of carboxyl groups in the hemolytic lectin CEL-III on its activities were investigated. When carboxyl groups were modified with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and glycine methyl ester, hemolytic activity of CEL-III decreased as the EDC concentration increased, accompanied by reduction of oligomerization ability and hemagglutinating activity. However, binding ability of CEL-III for immobilized lactose was retained fairly well after modification, suggesting that one of two carbohydrate-binding sites might be responsible for such inactivation of CEL-III.

Development and application of the 'Sleep Ukiha' automated sleep analysis system

We attempted to develop an automated sleep analysis system that uses a personal computer as an aid to the entire sleep research process. Analysis is based on electroencephalogram, chin muscle electromyogram and electrooculography, while other physiological phenomena can be handled arbitrarily. Major characteristics of the system include: (i) simultaneous gathering of physiological phenomena from up to three patients; (ii) high-speed waveform analysis; (iii) user-friendly operating environment through the use of a graphical user interface; and (iv) versatile utilization of analytical data in research.

NE-dlg, a mammalian homolog of Drosophila dlg tumor suppressor, induces growth suppression and impairment of cell adhesion: possible involvement of down-regulation of beta-catenin by NE-dlg expression

Membrane-associated guanylate kinases (MAGUKs) are known to function as scaffolds for forming multiprotein complexes at the synaptic junctions of neuronal cells and at sites of epithelial cell-cell contact. In Drosophila, mutations of the lethal (1)-discs large (dlg) gene, which encodes a MAGUK protein, leads to post-synaptic structure defects in neuronal cells and neoplastic overgrowth of epithelial cells. We previously showed that NE-dlg (neuronal and endocrine dlg), a human homolog of the dlg, plays a crucial role in formation of synaptic structure in human neuronal cells. Here we demonstrate that NE-dlg, similar to Drosophila dlg, is involved in regulation of cell cycle progression and adhesive ability of non-neuronal cells. Overexpression of NE-dlg in proliferating cells including various cancer cell lines induced growth suppression and impairment of cell adhesive ability. Furthermore, NE-dlg overexpression caused the down-regulation of beta-catenin in cancer cells regardless of mutations in the APC (adenomatous polyposis coli) gene. The PDZ domains of NE-dlg were found to be essential for the growth suppression, loss of adhesive property and down-regulation of beta-catenin. We propose that NE-dlg regulates the cell growth and adhesive ability by controlling the level of beta-catenin through an APC-independent pathway. Inactivation of NE-dlg may therefore contribute to development and/or progression of human neoplasms.

Anti-insulin receptor autoantibodies in a patient with type B insulin resistance and fasting hypoglycemia

We studied a patient with systemic lupus erythematosus and type B insulin resistance who showed almost complete normalization of postprandial plasma glucose in 3 months and a transient occurrence of fasting hypoglycemia from day 35 (i.e. the 35th day of hospitalization) to day 77. To determine the clinical relevance of the biological ability of anti-insulin receptor antibodies (anti-IRAb), we made multiple preparations of the patient's dialyzed serum and IgG. Dialyzed serum prepared on day 1 showed 95% inhibition of insulin binding. The binding inhibition was, however, decreased parallel to the normalization of insulin sensitivity. For 2DG uptake, 6.2 microM IgG purified on 3 different days (days 7, 35 and 78, designated IgG-NOV, -JAN, and -FEB, respectively) stimulated 2DG uptake into CHO-hIR at 3.4-, 3.1-, and 1.5-fold, respectively. Phosphotyrosine immunoblotting revealed that apparent insulin receptor autophosphorylation was visible only with IgG-NOV, not with the IgG-JAN or -FEB. Mutation of tyrosine-960 or lysine-1018 of the insulin receptor failed to transduce the IgG's stimulatory effect. IgG-NOV was not able to stimulate the autophosphorylation of the human IGF-I receptor. In the present study, the insulin binding inhibitory activities of the dialyzed sera prepared at different time points were shown to be altered parallel to insulin sensitivity in vivo. Stimulatory activities of the patient's IgG were, however, discordant for the occurrence of fasting hypoglycemia observed in vivo. Other pathogenic factors or mechanisms in addition to the insulin-like action of the anti-IRAb may be also required to fully understand the development of fasting hypoglycemia in type B insulin resistance.

A novel NE-dlg/SAP102-associated protein, p51-nedasin, related to the amidohydrolase superfamily, interferes with the association between NE-dlg/SAP102 and N-methyl-D-aspartate receptor

The membrane-associated guanylate kinase proteins have been known to interact various membrane receptors with their N-terminal segments designated the PDZ domains and to cluster these receptors at the target site of the cell membrane. NE-dlg/SAP102, a neuronal and endocrine tissue-specific MAGUK family protein, was found to be expressed in both dendrites and cell bodies in neuronal cells. Although NE-dlg/SAP102 localized at dendrites was shown to interact with N-methyl-D-aspartate receptor 2B via the PDZ domains to compose postsynaptic density, the binding proteins existing in the cell body of the neuron are still unknown. Here we report the isolation of a novel NE-dlg/SAP102-associated protein, p51-nedasin. Nedasin has a significant homology with amidohydrolase superfamily proteins and shows identical sequences to a recently identified protein that has guanine aminohydrolase activity. Nedasin has four alternative splice variants (S, V1, V2, and V3) that exhibited different C-terminal structures. NE-dlg/SAP102 is shown to interact with only the S form of nedasin which is predominantly expressed in brain. The expression of nedasin in neuronal cells increases in parallel with the progress of synaptogenesis and is mainly detected in cell bodies where it co-localizes with NE-dlg/SAP102. Furthermore, nedasin interferes with the association between NE-dlg/SAP102 and NMDA receptor 2B in vitro. These findings suggest that alternative splicing of nedasin may play a role in the formation and/or structural change in synapses during neuronal development by modifying clustering of neurotransmitter receptors at the synaptic sites.

Carbohydrate-dependent hemolytic activity of the conjugate composed of a C-type lectin, CEL-I, and an amphiphilic alpha-helical peptide, 4(3)-beta Ala2

A lectin-cationic peptide conjugate, 4(3)-CEL-I, was prepared from an invertebrate C-type lectin, CEL-I, and an amphiphilic alpha-helical peptide, 4(3)-beta Ala2 [Ac-(Leu-Ala-Arg-Leu)3-beta Ala2]. When 4(3)-CEL-I was incubated with rabbit erythrocytes, hemolysis was observed, especially at basic pH. Inhibition experiment using some carbohydrates suggested that hemolytic activity of 4(3)-CEL-I was caused by the interaction between 4(3)-beta Ala2 portion in the conjugate and the lipid bilayer after binding to the carbohydrate chains on the cell surface by the lectin activity of CEL-I.

Superiority of end-to-side anastomosis with the internal jugular vein: the experience of 80 cases in head and neck microsurgical reconstruction

The authors report their experience with 80 head and neck reconstructions using free-tissue transfer in which end-to-side anastomosis with the internal jugular vein was carried out. An end-to-side anastomosis with the internal jugular vein has the following advantages. Firstly, the technique overcomes the problems of vessel size discrepancy. It is effectively applied for free jejunal transfer or combined flap transfer based on a single vascular pedicle, of which the size of the proximal end of the drainage vein is very large. Secondly, the internal jugular vein has wide capacity to be the recipient of two or more end-to-side anastomoses. It is effectively used for free radial forearm or rectus abdominis myocutaneous flaps in which two or more drainage veins can be included. Thirdly, the respiratory venous pump effect may act directly on the venous drainage of the transferred flap through the internal jugular vein. In our institution, these advantages have made it the technique of choice in head and neck reconstructive microsurgery.

Interaction of NE-dlg/SAP102, a neuronal and endocrine tissue-specific membrane-associated guanylate kinase protein, with calmodulin and PSD-95/SAP90. A possible regulatory role in molecular clustering at synaptic sites

NE-dlg/SAP102, a neuronal and endocrine tissue-specific membrane-associated guanylate kinase family protein, is known to bind to C-terminal ends of N-methyl-D-aspartate receptor 2B (NR2B) through its PDZ (PSD-95/Dlg/ZO-1) domains. NE-dlg/SAP102 and NR2B colocalize at synaptic sites in cultured rat hippocampal neurons, and their expressions increase in parallel with the onset of synaptogenesis. We have identified that NE-dlg/SAP102 interacts with calmodulin in a Ca2+-dependent manner. The binding site for calmodulin has been determined to lie at the putative basic alpha-helix region located around the src homology 3 (SH3) domain of NE-dlg/SAP102. Using a surface plasmon resonance measurement system, we detected specific binding of recombinant NE-dlg/SAP102 to the immobilized calmodulin with a Kd value of 44 nM. However, the binding of Ca2+/calmodulin to NE-dlg/SAP102 did not modulate the interaction between PDZ domains of NE-dlg/SAP102 and the C-terminal end of rat NR2B. We have also identified that the region near the calmodulin binding site of NE-dlg/SAP102 interacts with the GUK-like domain of PSD-95/SAP90 by two-hybrid screening. Pull down assay revealed that NE-dlg/SAP102 can interact with PSD-95/SAP90 in the presence of both Ca2+ and calmodulin. These findings suggest that the Ca2+/calmodulin modulates interaction of neuronal membrane-associated guanylate kinase proteins and regulates clustering of neurotransmitter receptors at central synapses.

Characterization of the interaction of hemolytic lectin CEL-III from the marine invertebrate, Cucumaria echinata, with artificial lipid membranes: involvement of neutral sphingoglycolipids in the pore-forming process

The hemolytic lectin, CEL-III, is a Ca2+-dependent, galactose/N-acetylgalactosamine-specific lectin purified from the marine invertebrate, Cucumaria echinata (Holothuroidea). After binding to specific carbohydrates on the erythrocyte surface, CEL-III forms ion-permeable pores by oligomerizing in the membrane, which leads to colloid osmotic rupture of the cells. When incubated with liposomes composed of total lipids from the human erythrocyte membrane, CEL-III efficiently induced the leakage of carboxyfluorescein (CF) trapped in the vesicles, suggesting the presence of its receptor in the membrane lipids. The rate of CF-leakage increased with increasing temperature, although the hemolytic activity of CEL-III had been found to be much higher at lower temperatures (around 10 degrees C). Identification of the receptor for CEL-III was performed by examining the ability of individual lipids from human erythrocytes to induce CF-leakage from DOPC-liposomes. As a result, the most effective receptor was found to be lactosyl ceramide (LacCer), while globoside (Gb4Cer) also showed slight induction of CF-leakage. On the other hand, a binding assay involving CEL-III-horseradish peroxidase conjugate indicated that CEL-III exhibits similar affinity for LacCer and Gb4Cer, suggesting that the structure or length of the carbohydrate portion of sphingoglycolipids is also relevant as to their ability to induce CF-leakage in addition to their affinity. Electron micrographs of CEL-III-treated liposomes revealed that CEL-III induced considerable morphological changes in the vesicles, while a clearly distinguishable oligomeric structure of the protein was not observed.

The ultrastructural characteristics of eccrine sweat glands in a Fabry disease patient with hypohidrosis

As an investigation of the pathogenetic mechanism of diminished sweating in Fabry disease, an electron microscopy ultrastructural study was conducted on specimens of eccrine sweat glands from a typical patient with Fabry disease who had hypohidrosis, a low skin moisture content, and diminished thermoregulation ability. Numerous characteristic cytoplasmic inclusions were observed in the eccrine sweat glands, the lamellar pattern of which was considerably variable in various types of gland cells. Large vacuolar inclusions predominated in clear cells of secretory coil; lesser vacuoles were also seen in the coiled duct, and the basal cells of the straight duct toward the coiled duct displayed mulberry-like figures. There were some clear cells showing cell damage and necrosis in the secretory coil. Lamellated inclusions were noted in the unmyelinated axons innervating the eccrine sweat glands. The small blood vessels around the eccrine glands were narrowed by swollen endothelial cells with heavy inclusions. These intracytoplasmic deposits may be responsible for the decreased sweating ability in Fabry disease. The factors related to hypohidrosis are also discussed.

Chemical modification of the hemolytic lectin CEL-III by succinic anhydride: involvement of amino groups in the oligomerization process

CEL-III is a Ca(2+)-dependent lectin from a marine invertebrate, Cucumaria echinata, which shows strong hemolytic activity toward human and rabbit erythrocytes. After binding to carbohydrate receptors, CEL-III oligomerizes in the erythrocyte membrane to form ion-permeable pores, leading to the colloid osmotic rupture of the cells. Since hemolysis was greatly increased in the alkaline pH, especially above pH 9, involvement of amino groups of CEL-III in its hemolytic activity was evaluated using chemical modification by succinic anhydride. After modification of 7 amino groups per protein molecule, the hemolytic activity of CEL-III was reduced to 23% of the native protein, but hemagglutinating and carbohydrate-binding activities were only slightly affected even after modification of 14 amino groups. A circular dichroism spectrum of modified CEL-III showed almost no change in the secondary structure from that of the native protein, indicating that the decrease of hemolytic activity was not caused by partial unfolding of the protein. Immunoblotting analysis of the erythrocyte membrane treated with modified CEL-III showed a decrease in the formation of CEL-III oligomer in the membrane in parallel with the decrease in hemolytic activity. These results suggest that amino groups of CEL-III are involved in its oligomerization in the cell membrane, and their modification leads to inactivation of the protein without much influence on the carbohydrate-binding activity.