Psychometric properties of the Japanese version of the standardised assessment of personality abbreviated scale

This study was undertaken to translate the Standardised Assessment of Personality - Abbreviated Scale (SAPAS) into Japanese and to evaluate its validity and reliability. SAPAS is one of the most rapid tools for assessing personality disorder (PD) and has excellent sensitivity and good specificity, whereas other PD assessment tools require such a significant investment of time that they are infeasible for large surveys or routine clinical practice. Customary assessment in clinical practice ideally incorporates screening for PD, as it is associated with a substantial public health burden, including premature mortality and increased health service utilization. Furthermore, PD's status as a key prognostic variable of mental disorders also drives PD screening. While SAPAS has been translated into several languages, there has been no Japanese version. Therefore, we translated SAPAS into Japanese (SAPAS-J) and evaluated its reliability and validity. Study 1 recruited undergraduates to reveal its test-retest reliability. Although its internal consistency was not high, since the intent of the original SAPAS was to assess the broad character of personality disorder with the fewest possible items, minimal correlations between items were reasonable. We tested two factorial models, the single-factor model and the higher-order-single-factor model, and the latter offered better fitting. This higher-order model contained a three-factor structure corresponding to clusters described in DSM-5. It measures general PD traits as a common higher-order latent variable comprising those factors. Correlations of SAPAS-J with the much longer PD screening questionnaire in Study 1 and depressive and anxiety symptoms in Study 2 from the general population support its validity. Although validation for the clinical use of SAPAS-J is limited, our research with non-clinical populations demonstrated sufficient validity to justify its use in the context of psychopathological analog research. Since PD is understood as a continuum, the severity of which is distributed dimensionally, the analog study recruiting from the general population and attempting to reveal psychopathological mechanisms of PD is meaningful.

Validity, reliability, and correlates of the Smartphone Addiction Scale-Short Version among Japanese adults

BACKGROUND

The short version of the smartphone addiction scale (SAS-SV) is widely used to measure problematic smartphone use (PSU). This study examined the validity and reliability of the SAS-SV among Japanese adults, as well as cross-sectional and longitudinal associations with relevant mental health traits and problems.

METHODS

Datasets from a larger project on smartphone use and mental health were used to conduct two studies. Participants were adults aged over 20 years who carried a smartphone.

RESULTS

Study 1 (n = 99,156) showed the acceptable internal consistency and structural validity of the SAS-SV with a bifactor model with three factors. For the test-retest reliability of the SAS-SV, the intraclass correlation coefficient (ICC) was .70, 95% CI [.69, 70], when the SAS-SV was measured seven and twelve months apart (n = 20,389). Study 2 (n = 3419) revealed that when measured concurrently, the SAS-SV was strongly positively correlated with another measure of PSU and moderately correlated with smartphone use time, problematic internet use (PIU), depression, the attentional factor of impulsiveness, and symptoms related to attention-deficit hyperactivity disorder and obsessive-compulsive disorder. When measured 12 months apart, the SAS-SV was positively strongly associated with another measure of PSU and PIU and moderately associated with depression.

DISCUSSION

The structural validity of the SAS-SV appeared acceptable among Japanese adults with the bifactor model. The reliability of the SAS-SV was demonstrated in the subsequent seven- and twelve-month associations.

CONCLUSION

The cross-sectional and longitudinal associations of the SAS-SV provided further evidence regarding PSU characteristics.

Ecological momentary assessment of mind-wandering: meta-analysis and systematic review

Mind-wandering (MW) is a universal human phenomenon and revealing its nature contributes to understanding consciousness. The ecological momentary assessment (EMA), in which subjects report a momentary mental state, is a suitable method to investigate MW in a natural environment. Previous studies employed EMA to study MW and attempted to answer the most fundamental question: How often do we let our minds wander? However, reported MW occupancies vary widely among studies. Further, while some experimental settings may induce bias in MW reports, these designs have not been explored. Therefore, we searched PubMed and Web of Science for articles published until the end of 2020 and systematically reviewed 25 articles, and performed meta-analyses on 17 of them. Our meta-analysis found that people spend 34.504% of daily life in mind-wandering, and meta-regression revealed that using subject smartphones for EMA, frequent sampling, and long experimental duration significantly affect MW reports. This result indicates that EMA using subject smartphones may tend to collect sampling under habitual smartphone use. Furthermore, these results indicate the existence of reactivity, even in MW research. We provide fundamental knowledge of MW and discuss rough standards for EMA settings in future MW studies.

Effects of the Attention Training Technique on Brain Activity in Healthy University Students Assessed by EEG Source Imaging

This study aimed to investigate the neurocognitive effects of the Attention Training Technique (ATT) on brain activity in healthy participants. The participants included 20 university students who were asked to practice ATT as a homework assignment for 20 days. The intracerebral source localization of their electroencephalogram during rest and the ATT task, which comprised selective attention, attention switching, and divided attention conditions, was evaluated by standardized low-resolution brain electromagnetic tomography. Brain activity during rest was subtracted from that during the ATT task, and that was compared before and after the homework assignment. The results for the divided attention condition indicated significantly decreased alpha 1 frequency band power in the left orbital frontal cortex (OFC) and alpha 2 power in the right inferior temporal cortex. Further, decreased alpha 1 power in the left OFC correlated with reduced subjective difficulty during the divided attention condition. One possibility is that the brain activity changed as the effect of ATT practice, although this study cannot confirm causality. Further studies are required which include a control group that would complete similar training without the ATT task.

Changes in Mind-Wandering and Cognitive Fusion Through Mindfulness Group Therapy for Depression and Anxiety

The mechanisms of efficacy in mindfulness-based interventions for depression and anxiety are not fully understood. To clarify these mechanisms, we tested the hypotheses that mind-wandering, daydreaming, cognitive fusion, and experiential avoidance will decrease through mindfulness group therapy, and this decrease will correlate with improvements in depression and anxiety. Participants self-reported depression and/or anxiety (N = 28) took part in an 8-week mindfulness group therapy program. They were assessed using self-report scales at pre- and post-intervention, and at 2-month follow-up. Results indicated that depression and trait-anxiety decreased between pre- and post-intervention with moderate effect sizes, which were maintained at follow-up. Mind-wandering and cognitive fusion also decreased between pre- and post-intervention with small to moderate effect sizes, and maintained at follow-up. The decreases in mind-wandering and cognitive fusion moderately correlated with improvements in depression and anxiety, suggesting that decreases in mind-wandering and cognitive fusion might underlie efficacious mechanisms of mindfulness group therapy.

Dispositional Mindfulness Mediates the Relationship Between Sensory-Processing Sensitivity and Trait Anxiety, Well-Being, and Psychosomatic Symptoms

Recent studies have suggested that sensory-processing sensitivity correlates to poor psychological and physical health. However, it remains unclear how this occurs. Sensory-processing sensitivity can be understood as sensitivity to sensations without the presence of intentional awareness and a nonreactive attitude, which are the components of mindfulness. We tested the hypothesis that dispositional mindfulness mediates the relationship between sensory-processing sensitivity and trait anxiety, well-being and psychosomatic symptoms. We analyzed data from 563 participating young adults living in Japan. Multiple mediation analysis showed that the four facets (nonreactivity, nonjudging, describing, and acting with awareness) of mindfulness partially mediated the effects of sub-factors of sensory-processing sensitivity (low sensory threshold and ease of excitation) on trait anxiety. Nonreactivity, describing, and acting with awareness partially mediated the effect of low sensory threshold on well-being and fully mediated the effect of ease of excitation. Nonjudging and acting with awareness partially mediated the effects of low sensory threshold and ease of excitation on psychosomatic symptoms. As a whole, the mediation hypotheses were supported, and it was determined that the improvement of dispositional mindfulness may prove effective for the psychological and physical problems of people with high sensory-processing sensitivity.

Changes in depression and anxiety through mindfulness group therapy in Japan: the role of mindfulness and self-compassion as possible mediators

Background

Mindfulness-based interventions are increasingly being implemented worldwide for problems with depression and anxiety, and they have shown evidence of efficacy. However, few studies have examined the effects of a mindfulness-based group therapy based on standard programs for depression and anxiety until follow-up in Japan. This study addresses that gap. Furthermore, this study explored the mechanisms of action, focusing on mindfulness, mind wandering, self-compassion, and the behavioral inhibition and behavioral activation systems (BIS/BAS) as possible mediators.

Methods

We examined 16 people who suffered from depression and/or anxiety in an 8-week mindfulness group therapy. Measurements were conducted using questionnaires on depression and trait-anxiety (outcome variables), mindfulness, mind wandering, self-compassion, and the BIS/BAS (process variables) at pre- and post-intervention and 2-month follow-up. Changes in the outcome and process variables were tested, and the correlations among the changes in those variables were explored.

Results

Depression and anxiety decreased significantly, with moderate to large effect sizes, from pre- to post-intervention and follow-up. In process variables, the observing and nonreactivity facets of mindfulness significantly increased from pre- to post-intervention and follow-up. The nonjudging facet of mindfulness and self-compassion significantly increased from pre-intervention to follow-up. Other facets of mindfulness, mind wandering, and the BIS/BAS did not significantly change. Improvements in some facets of mindfulness and self-compassion and reductions in BIS were significantly correlated with decreases in depression and anxiety.

Conclusions

An 8-week mindfulness group therapy program may be effective for people suffering from depression and anxiety in Japan. Mindfulness and self-compassion may be important mediators of the effects of the mindfulness group therapy. Future studies should confirm these findings by using a control group.

Trial registration

University Hospital Medical Information Network (UMIN CTR) UMIN000022966. Registered July 1, 2016, https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000026425

Prediction of Mind-Wandering with Electroencephalogram and Non-linear Regression Modeling

Mind-wandering (MW), task-unrelated thought, has been examined by researchers in an increasing number of articles using models to predict whether subjects are in MW, using numerous physiological variables. However, these models are not applicable in general situations. Moreover, they output only binary classification. The current study suggests that the combination of electroencephalogram (EEG) variables and non-linear regression modeling can be a good indicator of MW intensity. We recorded EEGs of 50 subjects during the performance of a Sustained Attention to Response Task, including a thought sampling probe that inquired the focus of attention. We calculated the power and coherence value and prepared 35 patterns of variable combinations and applied Support Vector machine Regression (SVR) to them. Finally, we chose four SVR models: two of them non-linear models and the others linear models; two of the four models are composed of a limited number of electrodes to satisfy model usefulness. Examination using the held-out data indicated that all models had robust predictive precision and provided significantly better estimations than a linear regression model using single electrode EEG variables. Furthermore, in limited electrode condition, non-linear SVR model showed significantly better precision than linear SVR model. The method proposed in this study helps investigations into MW in various little-examined situations. Further, by measuring MW with a high temporal resolution EEG, unclear aspects of MW, such as time series variation, are expected to be revealed. Furthermore, our suggestion that a few electrodes can also predict MW contributes to the development of neuro-feedback studies.

Use of Multichannel Near Infrared Spectroscopy to Study Relationships Between Brain Regions and Neurocognitive Tasks of Selective/Divided Attention and 2-Back Working Memory

While dichotic listening (DL) was originally intended to measure bottom-up selective attention, it has also become a tool for measuring top-down selective attention. This study investigated the brain regions related to top-down selective and divided attention DL tasks and a 2-back task using alphanumeric and Japanese numeric sounds. Thirty-six healthy participants underwent near-infrared spectroscopy scanning while performing a top-down selective attentional DL task, a top-down divided attentional DL task, and a 2-back task. Pearson's correlations were calculated to show relationships between oxy-Hb concentration in each brain region and the score of each cognitive task. Different brain regions were activated during the DL and 2-back tasks. Brain regions activated in the top-down selective attention DL task were the left inferior prefrontal gyrus and left pars opercularis. The left temporopolar area was activated in the top-down divided attention DL task, and the left frontopolar area and left dorsolateral prefrontal cortex were activated in the 2-back task. As further evidence for the finding that each task measured different cognitive and brain area functions, neither the percentages of correct answers for the three tasks nor the response times for the selective attentional task and the divided attentional task were correlated to one another. Thus, the DL and 2-back tasks used in this study can assess multiple areas of cognitive, brain-related dysfunction to explore their relationship to different psychiatric and neurodevelopmental disorders.

Heat treatment effects on electrochemical corrosion parameters of high-Pd alloys

This research determined the effect oxidation, as that occurs during porcelain firing, has upon the corrosion parameters of Pd-based ceramic alloys and how it may relate to Pd allergy. The 20 h open circuit potential (OCP), 20 h corrosion rate (Icorr), and anodic polarization (E-i) curves of 11 commercial Pd alloys were measured in a phosphate buffered saline solution. The alloys were divided into the following four groups based upon composition: PdGa(Ag), PdCu, PdAg, and AuPd and tested in both as-cast and oxidized conditions. In both the as-cast and oxidized conditions, the OCP of Ag-containing Pd alloys is significantly lower than non Ag-containing high-Pd alloys. The OCP of all alloys increased after oxidation. With regard to corrosion rate, the Ag-containing alloys showed a decrease in Icorr with oxidation. In contrast, three of the four non Ag-containing high-Pd (>or=74 wt%) alloys exhibited a higher Icorr. A comparison of the anodic polarization curves showed only the alloys containing larger amounts (>or=16 wt%) of Ag displayed a notable difference between as-cast and oxidized states. Oxidation as required during porcelain-fused-to-metal device preparation alters the electrochemical characteristics of the alloys studied. This alteration may be of importance with regard to their potential for Pd allergy.

Physicochemical basis of the biologic properties of mineral trioxide aggregate

This study characterized the interactions of mineral trioxide aggregate with a synthetic tissue fluid composed of a neutral phosphate buffer saline solution and root canal dentin in extracted human teeth using inductively coupled plasma-atomic emission spectroscopy, scanning electron microscopy, energy dispersive X-ray analysis, and X-ray diffraction. Mineral trioxide aggregate exposed to synthetic tissue fluid at 37 degrees C released its metallic constituents and produced precipitates with a composition and structure similar to that of hydroxyapatite [Ca10(PO4)6(OH)2-HA]. Endodontically prepared teeth filled with mineral trioxide aggregate and stored in synthetic tissue fluid at 37 degrees C for 2 months produced at the dentin wall an adherent interfacial layer that resembled hydroxyapatite in composition. The authors conclude that Ca, the dominant ion released from mineral trioxide aggregate, reacts with phosphates in synthetic tissue fluid, yielding hydroxyapatite. The dentin-mineral trioxide aggregate interfacial layer results from a similar reaction. The sealing ability, biocompatibility, and dentinogenic activity of mineral trioxide aggregate is attributed to these physicochemical reactions.

Micro-X-ray diffraction observation of nickel–titanium orthodontic wires in simulated oral environment

A micro-X-ray diffraction (micro-XRD) technique has been employed to determine the phases in two superelastic nickel-titanium orthodontic wires that exhibit shape memory in the oral environment and one superelastic nickel-titanium wire that does not exhibit shape memory in vivo. The micro-XRD analyses were performed over the clinically relevant temperature range of 0-55 degrees C, which corresponds to the ingestion of cold and hot liquids, and both straight and bent (135 degrees ) test samples were analyzed. The results showed that for straight (as-received) test samples, the rhombohedral phase (R-phase) was definitely present in one shape memory wire product and perhaps in the other shape memory wire product, but was apparently absent in the superelastic wire product that did not display shape memory. Martensite was observed in all three wire products after bending. Phase transformations occurred with temperature changes simulating the oral environment for straight test samples of the two shape memory wires, but the micro-XRD pattern changed minimally with temperature for straight test samples of the superelastic wire and for bent test samples of all three wire products. The phase transformations revealed by micro-XRD were consistent with results recently found by temperature-modulated differential scanning calorimetry.

Micro X-ray diffraction study of superelastic nickel-titanium orthodontic wires at different temperatures and stresses

The phase transformation behavior in three commercial nickel-titanium orthodontic wires having different transformation temperatures was studied by micro X-ray diffraction (micro-XRD). Micro-XRD spectra were obtained at three different included bending angles (135 degrees, 146 degrees and 157 degrees) and three different temperatures (25 degrees C, 37 degrees C and 60 degrees C). The regions analyzed by micro-XRD were within the separate areas of a given wire specimen that experienced only tensile or compressive strain. The intensity ratio (M002/A110) between the 002 peak for martensitic NiTi and the 110 peak for austenitic NiTi was employed as the index to the proportions of the martensite and austenite phases. The ratio of martensite to austenite increased in all three nickel-titanium wires with decreasing included bending angle (greater permanent bending deformation), and was lower within the compression area for all wires at all bending angles than within the tension area. Micro-XRD provides an effective method for quantitative evaluation of the proportions of these two phases in nickel-titanium orthodontic wires, even though considerable preferred crystallographic orientation exists because of the wire drawing process.

Mechanical behavior at different temperatures and stresses for superelastic nickel-titanium orthodontic wires having different transformation temperatures

OBJECTIVE

The purpose of this study was to investigate the mechanical properties of superelastic nickel-titanium orthodontic wires under controlled stress and temperature.

METHODS

Three different superelastic nickel-titanium wires were examined using differential scanning calorimetry (DSC), three-point bending test and micro X-ray diffraction (micro-XRD). The three-point bending test was carried out at constant temperature (23, 37 and 60 degrees C) and stepwise temperature changes (37-60 degrees C and to 37 degrees C) (37-2 degrees C and to 37 degrees C). Five specimens of each wire were tested. Micro-XRD spectra were measured at the tension side of the wire when the temperature changed from 37 to 60 degrees C or 2 degrees C.

RESULTS

The load during the stepwise temperature changes (37-2 degrees C and to 37 degrees C) was consistent with that measured at a corresponding constant temperature. The micro XRD spectrum clearly showed that the austenite phase was transformed to martensite phase when the temperature is decreased from 37 to 2 degrees C. In a stepwise temperature change (37-60 degrees C and to 37 degrees C), the load became higher than the original load at each corresponding constant temperature. However, there was no detectable change in the micro-XRD spectrum when the temperature was increased from 37 to 60 degrees C.

SIGNIFICANCE

The superelastic nickel-titanium wires exhibited complicated and unexpected mechanical properties under stepwise temperature change. This study shows the possibility of qualitative analysis using micro-XRD to understand mechanical properties of these nickel-titanium wires.

Carbohydrate-carbohydrate binding of ganglioside to integrin alpha(5) modulates alpha(5)beta(1) function

Gangliosides GT1b and GD3, components of keratinocyte membranes, inhibit keratinocyte adhesion to fibronectin. Although ganglioside sialylation is known to be important, the mechanism of inhibition is unknown. Using purified insect recombinant alpha(5) and beta(1) proteins and alpha(5)beta(1) integrin from lysed keratinocyte-derived SCC12 cells, we have shown that GT1b and GD3 inhibit the binding of alpha(5)beta(1) to fibronectin. Co-immunoprecipitation of GT1b and alpha(5)beta(1) from SCC12 cells and direct binding of GT1b and GD3 to affinity-purified alpha(5)beta(1) from SCC12 cells and insect recombinant alpha(5)beta(1), particularly the alpha(5) subunit, further suggest interaction between ganglioside and alpha(5)beta(1). The carbohydrate moieties of integrin appear to be critical since gangliosides are unable to bind deglycosylated forms of alpha(5)beta(1) from SCC12 and insect cells or poorly glycosylated recombinant alpha(5)beta(1) from Escherichia coli cells. The GT1b-alpha(5)beta(1) interaction is inhibited by concanavalin A, suggesting that GT1b binds to mannose structures in alpha(5)beta(1). The preferential binding of GT1b to high mannose rather than reduced mannose ovalbumin further implicates the binding of GT1b to mannose structures. These data provide evidence that highly sialylated gangliosides regulate alpha(5)beta(1)-mediated adhesion of epithelial cells to fibronectin through carbohydrate-carbohydrate interactions between GT1b and the alpha(5) subunit of alpha(5)beta(1) integrin.

XPS study on the weakest zone in the adhesion structure between resin containing 4-META and precious metal alloys treated with different surface modification methods

Three precious metal alloys, Type IV gold alloy, 14 K gold alloy, and silver-based alloy, were treated with different surface modifications including a metal primer (VBATDT) application, a SiOx coating method, high-temperature oxidation, modification method with a liquid Ga-Sn alloy, and tin electroplating. Then thin PMMA films were bonded with a resin containing 4-META. Water durability at the adhesion interface was evaluated after water immersion, followed by thermal cycling used liquid nitrogen. The weakest zone at the interface was investigated using XPS only for the Ag-Pd alloy specimens that had been surface-treated with as-polishing, adhesive primer, and the SiOx coating method, since peeling of the PMMA film on the surface of specimens surface-treated by other methods was not observed. Metal elements were detected from the resin side at the adhesion interface. The chemical states of Cu in the resin before argon ion etching were characterized as metal oxides and/or states of chemical interaction with 4-META, VBATDT, or SiOx.

[A case of AIDS complicated with liver tuberculosis]

We experienced a double infection of tuberculosis and amebiasis of the liver. A 28 year old male with AIDS was admitted to our hospital because of severe diarrhea and liver abscess by Entamoeba histolytica. In spite of improvement of the diarrhea and liver abscess by the therapy against E. historicica, serum levels of gamma-GTP and ALP remained high and hepatosplenomegaly gradually increased. A liver biopsy was performed. Pathology showed a granulomatous lesion with Langhans' giant cells. From this specimen, IS6110 gene, a specific DNA for Mycobacterium tuberculosis was detected by PCR method. After anti-tuberculosis treatment was given for 6 months the increased serum gamma-GTP, ALP decreased and hepatosplenomegaly diminished.

Electrochemical characteristics of high-Pd alloys in relation to Pd-allergy

OBJECTIVE

The aim of this study was to determine whether the Pd-Cu-based dental ceramic alloys possess any electrochemical characteristics distinguishable from that of other Pd-containing alloys. Of all Pd-containing alloys, this particular alloy group has been linked to frequent incidence of allergy and hypersensitivity reactions. Electrochemical corrosion may instigate these reactions.

METHODS

Four groups of alloys, Pd-Cu, Pd-Ga-(with and without Ag), Pd-Ag, and Au-Pd, were evaluated by traditional corrosion measurement techniques in a phosphated buffer saline solution at 20 degrees C. The electrochemical characteristics measured were: (1) 20 h open circuit potential (OCP); (2) 20 h corrosion rate (Icorr); and (3) anodic polarization (E-i) curves.

RESULTS

The OCP values (232 +/- 25 mV) of the Ag-free Pd-Ga and Pd-Cu-based alloys were higher than and distinctly different from that (144 +/- 52 mV) of the Ag-containing alloys. The Icorr values of different alloys, despite varied compositions, were indistinguishable from one another. The E-i curves of all alloys were essentially similar, with the Ag-containing (> 5 wt%) alloys showing a subtle difference in their anodic slope within 100 mV above their corrosion potentials.

SIGNIFICANCE

The OCP values of Pd-Cu alloys and the Ag-free Pd-Ga alloy are comparable to that reported for pure Pd (239 +/- 21 mV), which indicates that during corrosion these alloys undergo dealloying and consequent Pd-enrichment on their surface. Such a condition is conducive to the release of allergenic Pd++ ions and offers a plausible explanation for the frequent incidence of hypersensitivity reactions associated with the Pd-Cu alloys. The OCP values in other alloys are attributed to dealloying followed by surface enrichment with Ag and/or Au and the possible formation of an insoluble AgCl surface film on the respective alloy surfaces. These events have the potential to suppress or prevent Pd++ ion release. Alloys showing these characteristics have seldom been linked to allergic reactions.

Effect of Pd or Au addition on age-hardening in AgMn-based alloys

OBJECTIVE

The objective of this research was to characterize the age-hardening behavior of AgMn alloys modified with Au or Pd. These alloys are being studied as possible alternatives to Type III dental alloys.

METHODS

The age-hardening reactions in Ag-37 at % Mn alloys with 5 at% Au or Pd were investigated by optical microscopy, electrical resistivity, X-ray diffraction and hardness tests.

RESULTS

Optical microscopy showed no grain boundary precipitates formed after overaging. The maximum hardness reached by aging in all alloys is about 260 (Hv) and identical to that of traditional AgPdCu dental alloys. The precipitation reactions were retarded with the addition of 5 at% Au or Pd. X-ray diffraction studies suggest a fine precipitate, alpha-Mn, is dispersed within the grain interior. The activation energy for the precipitation reaction is 114 kJ/mol for the AgMn and AgMnAu alloys. This value is about one-half of the activation energy for volume diffusion of manganese in AgMn alloys.

SIGNIFICANCE

The age-hardenable AgMn-based alloys modified with Au or Pd can achieve hardness values comparable to those of traditional AgPdCu alloys. Provided the in vivo corrosion resistance of these alloys is adequate, they show promise as a Cu-free alternative material for cast restorations.

Relationship between Af temperature and load changes in Ni-Ti orthodontic wire under different thermomechanical conditions

Simple three point bending tests were performed on Ni-Ti wires with three different Af points (1 degree C, 13 degrees C and 34 degrees C) to clarify the relationship between Af temperature and load changes under constant deformation. Each wire was deformed at 37 degrees C and then thermal changes were imposed by temperatures of 2 degrees C or 60 degrees C. The load changes with thermal changes from 37 degrees C to 2 degrees C or 60 degrees C showed the same tendency on the wires with different Af points: In the loading stage, the load became lower than the initial level at 37 degrees C and in the unloading stage, the load became higher than the initial load. The largest load change in the unloading stage was measured with the 13 degrees C Af point wire. Care must be taken when handling Ni-Ti wire with an Af point of less than 1 degree C in order to prevent it from reaching the limit of critical stress of slip deformation when the temperature in the mouth rises to above 40 degrees C.

Identification of HLA-A3-restricted cytotoxic T lymphocyte epitopes from carcinoembryonic antigen and HER-2/neu by primary in vitro immunization with peptide-pulsed dendritic cells

The human carcinoembryonic antigen (CEA) and HER-2/neu are potential target antigens for CTL specific immunotherapy for common malignancies such as breast, lung, colon, and gastric carcinomas. Several CTL epitopes restricted by HLA-A2, the most common human histocompatibility molecule, have been previously reported. However, to develop CTL-based immunotherapies for the general population, it is necessary to identify epitopes restricted by other common histocompatibility alleles. Here, we describe two HLA-A3-restricted CTL epitopes from the CEA and HER-2/neu antigens. HLA-A3 binding synthetic peptides from CEA and HER-2/neu were tested for immunogenicity by in vitro primary CTL induction protocol using peripheral blood mononuclear cells from normal healthy volunteers. One peptide from CEA (CEA[9(61)]: HLFGYSWYK) and one peptide from HER-2/neu (HER2[9(754)]: VLRENTSPK) were shown to induce CTL that was capable of killing a tumor cell line expressing HLA-A3 and the corresponding tumor-associated antigen. Additional MHC binding studies with the most common HLA molecules belonging to the HLA-A3 superfamily (HLA-A*1101, -A*3101, -A*3301, and -A*6801), demonstrated that CEA[9(61)] binds five of five A3 supertype molecules with high affinity, and the HER2[9(754)] epitope was able to bind to four of the same five alleles. These results indicate that these two new CTL epitopes should be immunogenic in individuals expressing either HLA-A3, or other members of the HLA-A3 superfamily.

Adhesion of adhesive resin to dental precious metal alloys. Part II. The relationship between surface structure of Au-In alloys and adhesive ability with 4-META resin

Adhesion of 4-META to Au-In alloy was improved by adding In equivalent to .15% of Au content. On the basis of the results of Au-In alloys analyzed by XPS, the present study investigated the reason why adhesion of the Au-In alloy was improved. The O 1s spectrum could be separated into three oxygen chemical states, In2O3, chemisorbed H2O, and physisorbed H2O. The amount of chemisorbed H2O decreased remarkably with increasing amount of In. It is considered that the poor adhesive ability of the pure gold and alloys containing only small amounts of In was due to the chemisorbed H2O molecules and insufficient indium oxide on the alloy surface. It was established that excellent adhesion requires an oxide with chemical affinity for 4-META to cover at least 50% of the alloy surface.

Identification of gp100-derived, melanoma-specific cytotoxic T-lymphocyte epitopes restricted by HLA-A3 supertype molecules by primary in vitro immunization with peptide-pulsed dendritic cells

The human melanocyte lineage-specific antigen gp100 contains several epitopes recognized by cytotoxic T lymphocytes (CTL). However, most of the epitopes reported to date are HLA-A2.1-restricted. Despite the high frequency of HLA-A2.1 in melanoma patients, effective population coverage requires the identification of epitopes restricted by other frequent HLA alleles. Herein, HLA-A3 binding, gp100-derived synthetic peptides were tested for their capacity to elicit anti-melanoma CTL in vitro using CD8+ T cells from healthy donors as responders and peptide-pulsed autologous dendritic cells as antigen-presenting cells. Of 7 peptides tested, 2 (gp100[9(87)] and gp100[10(86)]) induced CTLs that killed melanoma cell lines expressing HLA-A3 and gp100. Additional MHC-binding studies to various HLA molecules belonging to the HLA-A3 superfamily (HLA-A*1101, -A*3101, -A*3301 and -A*6801) were performed to determine whether these CTL epitopes could further increase potential population coverage. Further experiments indicated that the peptide gp100[9(87)], which bound to HLA-A11 with high affinity, was capable of inducing specific CTLs that killed melanoma cells expressing gp100 and HLA-A11 molecules. Our results indicate that the gp100[9(87)] peptide corresponds to a CTL epitope which may be restricted by either the HLA-A3 or HLA-A11 allele, emphasizing its utility for the design and development of epitope-based therapies for melanoma.

Corrosion of three experimental AgMn-based casting alloys

OBJECTIVE

Alloys based on AgMn are being evaluated in our laboratory for their possible use as an alternative to Type III dental alloys. They respond to heat treatment and develop hardness values comparable to that of Type III alloys. The objective of the present research was to evaluate their corrosion characteristics.

METHODS

The three experimental silver-based alloys of the following composition (at%): (1) 63Ag37Mn, (2) 60Ag35Mn5Au and (3) 60Ag35Mn5Pd, were tested in their peak-hardened condition. Following 0.5 h open-circuit potential (OCP) measurement of each alloy in a phosphated buffer saline (PBS) solution, its current-potential profile was generated by the cyclic voltammetry technique within -1300 and +200 mV (SCE) at 1 mV s-1. In a separate test, the OCP of each alloy was monitored over a 24 h period.

RESULTS

Each of the three alloys showed ennoblement of their OCP over time due to dissolution of Mn and consequent enrichment with Ag (Au or Pd). At 24 h, the two ternary alloys were the most noble followed by the binary alloy. With respect to the cyclic voltammetry, oxidation of Ag was noted during forward scans at around 0 mV. The reverse scan was associated with a reduction current peak between -37 and -128 mV. The values for this peak, which is a measure of Ag oxidation, were highest (11.5 mA cm-2) for the binary alloy followed by the Au- (2.9 mA cm-2) and Pd-containing (0.04 mA cm-2) alloys, respectively. This indicates that, for equivalent concentration, Pd is more effective in reducing Ag corrosion than Au.

SIGNIFICANCE

Alloys based on the AgMn system are as hard as Type III dental alloys. Information on the corrosion characteristics of the AgMn-based alloys presented here is of value in further development of this alloy system.

[A case of bacillary dysentery caused by new quinolone-resistant Shigella flexneri 2a]

A 73-year-old male was admitted to our hospital because of detection of Shigella flexneri 2a from his stool. Antimicrobial treatment with levofloxacin (LVFX) was started, but could not eliminate the organism in the stool. In the examination of drug susceptibility, this strain was highly resistant to all new quinolones. The minimal inhibitory concentration of norfloxacin, ofloxacin and ciprofloxacin to this strain was 12.5 micrograms/ml, 6.25 micrograms/ml and 6.25 micrograms/ml, respectively. The dual mutations were detected in the codon 83 and 87 of the gyrA gene by sequencing the quinolone-resistance determining region (QRDR). There was, however, no significant difference between the intracellular uptake of ciprofloxacin in this strain and in the ciprofloxacin-sensitive strain. The amount of ciprofloxacin in this strain unchanged when carbonyl cyanide m-chlorophenyl hydrazone (CCCP) was added. These results suggest that the advanced resistance in Shigella flexneri against new quinolones could be acquired by only this dual mutations without the change of the active efflux mechanism.

Delineation of the epitope recognized by an antibody specific for N-glycolylneuraminic acid-containing gangliosides

P3 is a mouse monoclonal antibody (mAb) that binds to several NeuGc-containing gangliosides. It also reacts with antigens expressed in human breast tumors (Vázquez et al. (1995) Hybridoma , 14, 551-556). In this work, the binding specificity of P3 has been characterized in more detail using a panel of glycolipids that included several disialylated gangliosides and several chemical derivatives of NeuGc-GM3. The carboxyl group and the nitrogen function of sialic acid were found to play important roles in the antibody binding, whereas the glycerol tail appears to be nonrelevant. Molecular modeling was used to analyze the binding data, including the finding that P3 selectively recognizes the internal NeuGc in GD3. For this purpose, conformational studies of GD3 were performed using molecular dynamics. It was concluded that sialic acid binds the P3 antibody through its upper face (the one on which the carboxyl group is exposed) and the C4-C5 side of the sugar ring, whereas none or very little contact between the galactose residue and the protein is evident. Conformational analysis of GD3 revealed that, despite the large flexibility of the NeuGcalpha8NeuGc linkage, the P3 binding epitope on the external sialic acid is not well exposed for any of the possible conformations this linkage can adopt, whereas the internal sialic acid presents the epitope in a proper way for several of these conformations. As a final result, a coherent picture of the epitope that fits the wide binding data was obtained.

An immunocytochemical technique with monoclonal antibodies to glycosphingolipids in rat primary cerebellar cultures: influence of detergent permeabilization

Glycosphingolipids (GSLs) are highly expressed in the vertebrate central nervous system. GSLs have been implicated in a variety of phenomena involving cell-cell recognition, neurite outgrowth, synaptogenesis, transmembrane signalling and cell growth and differentiation. We recently determined the distribution of GSLs in rat brain tissues and in primary rat cerebellar cultures as well as using a number of MAbs to GSLs, which were generated and characterized in our laboratory. These results suggested that (i) the expression of GSLs was highly localized to a specific cell type and layer in the rat brain tissues and (ii) some GSLs may be useful markers for identifying cells in the primary cultures. In the present paper, we describe in detail an immunofluorescence technique for the detection of GSL expression in the primary cultures. We demonstrate that the localization of GSLs can be greatly influenced by detergent treatments.

In vitro immunization and expansion of antigen-specific cytotoxic T lymphocytes for adoptive immunotherapy using peptide-pulsed dendritic cells

The design of an effective procedure to sensitize and expand antigen-specific cytotoxic T lymphocytes (CTL) in vitro is essential for the development of effective adoptive cellular immunotherapy protocols for cancer. We have analyzed the capacity of tissue culture-derived dendritic cells (DC) to present specific peptide epitopes to CTL precursors. Our results demonstrate that peptide-pulsed DC were efficient in generating CTL responses specific for various viral and tumor epitopes. Furthermore, IL-7 and IL-10 potentiated the ability of the peptide-pulsed DC to trigger antigen-specific CTL responses. The CTL generated using this procedure efficiently recognized the naturally processed antigens and could be expanded approximately 100- to 1000-fold in tissue culture in 10 to 15 days without a loss of activity and specificity. The results and procedures described herein may facilitate the development of effective CTL-based adoptive immunotherapy for chronic viral diseases and cancer.

The multi-epitope approach for immunotherapy for cancer: identification of several CTL epitopes from various tumor-associated antigens expressed on solid epithelial tumors

One approach to development of specific cancer immunotherapy relies on the induction of cytotoxic T lymphocytes (CTL) specific for tumor-associated antigens (TAA). Induction of TAA-specific CTL could be used towards the eradication of established tumors, or to prevent their dissemination or recurrence after primary treatment. The present study identifies a set of CTL epitopes from TAA frequently found on solid epithelial tumors such as breast, lung and gastro-intestinal tumors. Specifically, HLA-A2.1 binding peptides from the MAGE2, MAGE3, HER-2/neu and CEA antigens were tested for their capacity to elicit in vitro anti-tumor CTL using lymphocytes from normal volunteers and autologous dendritic cells as antigen-presenting cells. A total of 6 new epitopes (MAGE2[10(157)], MAGE3[9(112)], CEA[9(691)], CEA[9(24)], HER2[9(435)] and HER2[9(5)]) were identified which were capable of specifically recognizing tumor cell lines lines expressing HLA-A2.1 and the corresponding TAA. In one case (CEA[9(24)]), induction of vigorous anti-tumor CTL responses required epitope engineering to increase HLA-A2.1 binding affinity. Finally, most of the newly identified epitopes (5 out of 6) were found to be highly crossreactive with other common HLA alleles of the A2 supertype (A2.2, A2.3, A2.6 and A6802), thus demonstrating their potential in providing broad and non-ethnically biased population coverage. The results are discussed in the context of the development of multi-epitope-based therapies with broad applicability for patients suffering from commonly found tumors.

Changes in composition of newly synthesized sphingolipids of HeLa cells during the cell cycle -- suppression of sphingomyelin and higher-glycosphingolipid synthesis and accumulation of ceramide and glucosylceramide in mitotic cells

Sphingolipid biosynthesis in synchronized HeLa cells was studied by pulse labeling with [14C]Ser or [14C]Gal and a simple TLC method. The major HeLa cell sphingolipids are ceramide (Cer), sphingomyelin, glucosylceramide (GlcCer), lactosylceramide (LacCer), globotriaosylceramide (Gb3Cer), N-acetylneuraminosylgangl iotriaosylceramide (GM2) and sialylparagloboside (G[M1-GlcNAc]). The sphingolipid biosynthetic profiles of HeLa cells in the G1, G1/S boundary, S and G2 phases were similar, but significant changes occurred during M phase, when incorporation of radioactivity into sphingomyelin, Gb3Cer and a mixture of GM2 and G(M1-GlcNAc) decreased, and those of Cer and GlcCer increased. These data indicate that transfer of phosphocholine and galactose to Cer and GlcCer, respectively, decreased in mitotic cells, resulting in accumulation of Cer and GlcCer. Analysis of LacCer synthase activity revealed that GlcCer accumulation was not due to reduced activity of this enzyme. The results suggest that Cer and GlcCer accumulation in mitotic cells resulted from suppression of sphingomyelin and LacCer synthesis, probably caused by vesiculation of membranous organelles, such as the endoplasmic reticulum and Golgi apparatus.

[A case report--typhoid fever complicated with liver and gallbladder abscess, treated for long-time as fever of unknown origin]

A 25-year-old male admitted to Kawasaki municipal hospital with the diagnosis of typhoid fever. He had noticed high fever since one month ago, and had been treated with prednisolone with the diagnosis of fever of unknown origin in a hospital. Then he had admitted to St. Marianna University Hospital, and Salmonella Typhi had been detected from his blood and stool. On admission, multiple liver abscess were detected by abdominal ultrasonography. S. Typhi in bile was not eliminated with CP and AMPC, but he was successfully treated with cholecystectomy and the chemotherapy of LVFX. Abscess formation was found in the resected gall bladder wall. Typhoid nodule in the lymph node, liver or other organs is a well known pathological change in the typhoid fever. But abscess formation in the liver or other organs is rare. In this case, multiple abscess is characteristic and this cause is thought to be induced by the factors that the period from onset of typhoid fever to beginning of effective therapy was too long, and that steroid therapy was done without antibiotic therapy.

Cloning and characterization of a novel oxidoreductase KDRF from a human bone marrow-derived stromal cell line KM-102

A cDNA clone coding for a novel oxidoreductase was cloned from a human bone marrow-derived stromal cell line KM-102. We screened a cDNA library constructed from the mRNA of KM-102 cells stimulated with phorbol 12-myristate 13-acetate and calcium ionophore A23187 using a 32P-labeled 15-mer synthetic oligonucleotide (5'-TAAATAAATAAATAA-3') probe. This probe was designed as a complementary sequence to the three reiterated AUUUA sequences, which are contained in the 3'-untranslated regions of cytokine and some proto-oncogene mRNAs and correlate with rapid mRNA turnover. Then, we obtained one cDNA clone, and further sequence analysis revealed that it coded for a new protein exhibiting 30 to approximately 40% homology with glutathione reductase. By fusion protein analysis, this protein showed reducing activities on 2, 6-dichlorophenol-indophenol and 5,5'-dithio-bis(2-nitrobenzoic acid) but only a weak reducing activity on oxidized glutathione. Although it lacked a stretch of hydrophobic amino acids in its N terminus, it was secreted by monkey kidney-derived COS-1 cells when we introduced the expression plasmid into them and also secreted by a human lung carcinoma cell line A549. Northern blot analysis revealed that the mRNA turnover of this protein was regulated by inflammatory stimuli in KM-102 cells. These results show that this protein may have scavenging enzyme properties and has its mRNA expression regulated in a similar fashion to cytokine genes or proto-oncogenes. Thus, we named it KDRF (KM-102-derived reductase-like factor), and KDRF may play a role in scavenging reactive oxygen intermediates, which are possibly toxic to cells, in response to inflammatory stimuli.

Evaluation of water durability at adhesion interfaces by peeling test of resin film

The water durability at adhesion interfaces was investigated by measurement of the peeled area of thin resin films bonded with 4-META resin on metal surfaces after imposing thermal stress using liquid nitrogen. Thermal stress at the adhesion interface was calculated by a computer-aided finite element method. On 18-8 stainless-steel specimens which bond strongly with 4-META resin, total interface failure occurs on specimens with resin thicker than 0.55 mm in dry condition. A resin layer of 0.25 mm was chosen to study degradation of the adhesion interface by water. The shearing stress was calculated as 16 MPa for a 0.25 mm thick resin layer. On mild-steel adherent interface with 4-META resin which degrades rapidly by water molecule, the relationship between water immersion time and degradation at the adhesion interface was discussed together with the amount of water penetrated at the interface. The method proposed in the present study is effective as a quick evaluation method for water durability at the adhesion interface.

Immunocytochemical analysis of gangliosides in rat primary cerebellar cultures using specific monoclonal antibodies

We studied the expression of ganglioside antigens in primary cultures of rat cerebellum using an immunocytochemical technique with mouse monoclonal antibodies (MAbs) specific for various gangliosides. Twelve MAbs that specifically recognize each ganglioside were used. Our study revealed that there is a cell type-specific expression of ganglioside antigens in the primary cultures. A number of b-series gangliosides were detected in the granule cells, whereas a-series gangliosides were not intensely expressed. GD1b was detected in the granule cells. GD2 appeared to be present in a subset of the granule cells or a type of small neurons. GD3 was associated not only with the granule cells, but also with both astrocytes and oligodendrocytes. An O-Ac-disialoganglioside, which was suggested to be O-Ac-LD1, was restrictedly detected in Purkinje cells. The other gangliosides were not detected clearly in these cells. These results suggest that several gangliosides may be useful markers for identifying cells in primary cultures of the rat cerebellum; particularly b-series gangliosides such as GD2 and GD1b for the granule cells and O-Ac-LD1 for Purkinje cells.

Acceptor substrate specificity of a cloned GD3 synthase that catalyzes the biosynthesis of both GD3 and GD1c/GT1a/GQ1b

To address the role of alpha2,8-sialyltransferase (GD3 synthase) in the biosynthesis of gangliosides, we examined the substrate specificity of the enzyme. In the ganglioside synthesis pathway, it has been generally accepted that sialyltransferase II (SAT II) catalyzes the production of GD3 from GM3, and sialyltransferase V (SAT V) catalyzes the production of GD1c/GT1a/GQ1b from GM1h/GD1a/GT1b. However, acceptor specificity of the clones GD3 synthase that was isolated from human melanoma cells [Nara, K., Watanabe, Y., Maruyama, K., Kasahara, K., Nagai. Y. & Sanai, Y. (1994) Proc. Natl Acad. Sci. USA 91, 7952-7956] has revealed that this enzyme utilized the gangliosides containing the terminal Sia(alpha2-3)Gas structure of the carbohydrate moiety, which includes GM3, GM1b, GD1a and GT1B as exogenous substrates. Kinetic data also showed that the enzyme was able to utilize both GM3 and GM1b/GD1a/GT1b as acceptor substrates. These data indicate that the enzyme catalyzes the formation of not only GD3 but also GD1c, GT1a, and GQ1B in vitro. Furthermore, by transfection of the cloned human alpha2,8-sialyltransferase cDNA, transient and stable expression of GT1a and GQ1b wa also observed in COS-7 cells and Swiss 3T3 cells that originally lacked SAT II and SAT V activities. These observations indicate that the enzyme has both SAT II and SAT V activities in vivo.

Generation and characterization of anti-sulfoglucuronosyl paragloboside monoclonal antibody NGR50 and its immunoreactivity with peripheral nerve

Sulfoglucuronosyl paragloboside (SGPG) is a member of the sulfated glucuronic acid-containing glycolipid (SGGL) family found primarily in peripheral nerves. These glycolipids contain the HNK-1 carbohydrate epitope and are recognized by monoclonal IgM from patients with chronic demyelinating neuropathy and paraproteinemia. Recent studies indicate that SGGLs may serve as ligands for selectins, amphoterin, and laminin, suggesting that these glycolipids may play an important role in cellular adhesion. To elucidate the biological function of these glycolipids, we produced a murine monoclonal antibody (mAb) and studied its antigenic specificity. Using an enzyme-linked immunosorbent assay (ELISA), we found that the mAb designated as NGR50 belonged to the IgG2a subclass, and that the minimal titer (2 SD above the mean optical density value of control) of this mAb was 1:640, with 20 ng of purified SGPG as the antigen. Thin-layer chromatography (TLC) immunoblotting revealed that this mAb reacted specifically with SGPG and sulfoglucuronosyl lactosaminyl paragloboside (SGLPG), which is a structural analogue of the former, but not with other glycolipids. Desulfated derivates of SGPG and SGLPG did not react with mAb NGR50. Western blot analysis showed crossreactivity with human myelin-associated glycoprotein (MAG), but not with rat MAG or rat glycoprotein P0. Unlike anti-HNK-1 monoclonal antibody, however, NGR50 reacted only weakly with several proteins in the 20-30-kD regions, including human P0, suggesting that mAb50 has a different fine specificity as an anti-HNK-1 antibody. Immunocytochemical study of rat sciatic nerve using mAb NGR50 revealed positive staining at the outer surface of the myelin sheath and Schwann cells, as well as in the intervening connective tissues. Faint staining was also visible at the axolemmal-myelin interface; however, compact myelin was not stained.

CD34+ human marrow cells that express low levels of Kit protein are enriched for long-term marrow-engrafting cells

Using in utero transplantation into fetal sheep, we examined the capability of human bone marrow CD34+ cells fractionated based on Kit protein expression to provide long-term in vivo engraftment. Twelve hundred to 5,000 CD34+ Kit-, CD34+ Kit(low), and CD34+ Kit(high) cells were injected into a total of 14 preimmune fetal sheep recipients using the amniotic bubble technique. Six fetuses were killed in utero 1.5 months after bone marrow cell transplantation. Two fetuses receiving CD34+ Kit(low) cells showed signs of engraftment according to analysis of CD45+ cells in their bone marrow cells and karyotype studies of the colonies grown in methylcellulose culture. In contrast, two fetuses receiving CD34+ Kit(high) cells and two fetuses receiving CD34+ Kit- cells failed to show evidence of significant engraftment. Two fetuses were absorbed. A total of six fetuses receiving different cell populations were allowed to proceed to term, and the newborn sheep were serially examined for the presence of chimerism. Again, only the two sheep receiving CD34+ Kit(low) cells exhibited signs of engraftment upon serial examination. Earlier in studies of murine hematopoiesis, we have shown stage-specific changes in Kit expression by the progenitors. The studies of human cells reported here are in agreement with observations in mice, and indicate that human hematopoietic stem cells are enriched in the Kit(low) population.

Importance of the carboxy-terminus of human interleukin-11 in conserving its biological activity

Biological activities of the carboxy-terminal (C-terminal) deletion mutants of human interleukin-11 (IL-11) were analyzed. Removal of only 1 amino-acid residue (leucine) from the C-terminus caused nearly an 80% loss of its biological activity. This shows the importance of C-terminus of human IL-11 in terms of conserving the biological activity.

Characterization of c-kit expression by primitive hematopoietic progenitors in umbilical cord blood

Human umbilical cord blood (CB) appears to be an exciting new source of transplantable stem cells for a variety of clinical conditions. In this study, we have attempted to further characterize the primitive progenitors in CB. First we analyzed the effects of early-acting growth factors on blast cell colony formation from CD34+ progenitors. Addition of Steel factor (SF), interleukin-6 (IL-6), or granulocyte colony-stimulating factor (G-CSF) to cultures containing interleukin-3 enhanced blast cell colony formation. These results indicated that cell cycle-dormant progenitors are present in CB. Next, based on results obtained in the murine system, we tested whether c-kit expression could separate the CB progenitors into cycle-dormant vs. cycle-active progenitors. Cells were separated into CD34+ c-kit-, c-kitlow, and c-kithigh. The results suggested that the c-kitlow population contains the majority of cycle-dormant progenitors and the c-kithigh population contains most of the forming cells were in the c-kitlow population, while the opposite is true for other colony-forming cells. Expression of c-kit may be useful in identifying CB progenitors with long-term engraftment capability.

Malignant transformation of rat embryo fibroblasts by cotransfection with eleven human mutant p53 cDNAs and activated H-ras gene

Eleven different missense and one nonsense mutant-type p53 cDNAs, which have been frequently detected in human colorectal carcinomas, were constructed and examined for their ability to cooperate with activated human H-ras genes, pSK2 and pHs49, in transfection of rat embryo fibroblasts (REF). Each missense mutant-type p53 cDNA with either of the two activated H-ras genes transformed REF with a different frequency of transformation depending on the different kind of mutation, whereas wild-type p53 (with ras), nonsense mutant-type p53 (with ras), as well as mutant-type p53 (alone) and ras (alone), did not transform REF. Six transformed REF cell lines were established from cotransfection with missense mutant-type p53 cDNA and ras gene; all of them exhibiting exogenous human p53 DNA, RNA, protein, and H-ras DNA and RNA. All six transformed cell lines showed both tumorigenicity and lung metastatic potential in nude mice. They also exhibited 92 kilodalton gelatinase activity, which was not detected in parental REF. These results suggest that missense mutations in p53 gene have a role in malignant transformation as well as metastatic potential.

Expression of de-N-acetyl-gangliosides in human melanoma cells is induced by genistein or nocodazole

Neuraminic acid is the core structure of most known sialic acids. In natural systems, the amino group at the 5 position of neuraminic acid residues is usually assumed to be acylated. Previously, synthetic de-N-acetyl-gangliosides (with free amino groups at the 5 position of neuraminic acids) have been shown to modulate cellular proliferation and tyrosine phosphokinase reactions. While indirect evidence has suggested that traces of these molecules exist naturally in certain tumor cells, further exploration has been hampered by the lack of a system showing consistent expression at an easily detectable level. Using synthetic compounds as antigens, we have developed highly specific monoclonal antibodies against de-N-acetyl-GM3 and de-N-acetyl-GD3 that require both the free amino group and the exocyclic side chain of sialic acids for recognition. Cultured human melanoma cells showed low but variably detectable levels of reactivity with these antibodies. The ability of various biologically active molecules to stimulate this reactivity was explored. Of many compounds tested, only the tyrosine kinase inhibitor genistein induced reactivity in a dose-dependent manner. Antibody reactivity with ganglioside extracts from genistein-treated cells was abolished by chemical re-N-acetylation and/or truncation of sialic acid side chains by mild periodate oxidation. High performance thin layer chromatography immuno-overlay analysis confirmed the presence of the novel compound de-N-acetyl-GD3 in these extracts. Several other tyrosine kinase inhibitors tested did not give the same increase in de-N-acetyl-ganglioside expression. However, the microtubule inhibitor nocodazole caused a similar accumulation of these molecules, particularly in non-adherent cells expected to be arrested at metaphase. Thus, genistein may induce de-N-acetyl-ganglioside expression by virtue of its known ability to arrest cells in the G2M phase, rather than as a general consequence of tyrosine kinase inhibition. These studies also provide a system in which to analyze the enzymatic basis of de-N-acetyl-ganglioside expression and their potential roles as growth regulating molecules.

Polysialogangliosides expressed by amelanotic melanoma: a possible explanation for the poor response to anti-monosialoganglioside antibody 202 in a patient with melanoma

A 52-year-old Japanese woman developed numerous amelanotic metastatic melanomas on the skin and in various organs three years after a surgical operation for primary melanoma on the right axilla. The patient was treated with monosialoganglioside specific monoclonal antibody 202; however, no apparent clinical effects were observed. Ganglioside analysis of a metastatic tumor demonstrated that it expressed GM3, GM2, GD3, GD2, and polysialogangliosides. Since polysialogangliosides rarely appear in melanomas, their expression may explain the patient's poor response to MAb 202. The relationship between ganglioside composition and the effect of anti-ganglioside monoclonal antibody is discussed.

Expression of sialylparagloboside in a case of liposarcoma: aberrant glycosylation in tumors arising in adipose tissues

Gangliosides of liposarcoma, lipoma and lipids from omental tissues were analyzed. By immunostaining after thin layer chromatography, gangliosides of liposarcoma were identified as GM3, sialylparagloboside and GD3, whereas those of lipoma were GM3 and GD3, and those of fat in omental tissues were GM3, GD1a, GD3 and some unknown ones. Expression of sialylparagloboside is thought to be very rare.

Thioredoxin h is one of the major proteins in rice phloem sap

Sieve tubes play important roles in the transfer of nutrients as well as signals. Hundreds of proteins were found in pure phloem sap collected from rice (Oryza sativa L. cv. Kantou) plants through the cut ends of insect stylets. These proteins may be involved in nutrient transfer and signal transduction. To characterize the nature of these proteins, the partial amino-acid sequence of a 13-kDa protein, named RPP13-1, that was abundant in the pure phleom sap was determined. A cDNA clone of 687 bp, containing an open reading frame of 122 amino acids, was isolated using corresponding oligonucleotides as a probe. The deduced amino-acid sequence was very similar to that of the ubiquitous thiol redox protein, thioredoxin. The consensus sequences of thioredoxins are highly conserved. No putative signal peptide was identified. Antiserum against wheat thioredoxin h cross-reacted with RPP13-1 in the phloem sap of rice plants. RPP13-1 produced in Escherichia coli was reactive to antiserum against wheat thioredoxin h. Both E. coli-produced RPP13-1 and the phloem sap proteins catalyzed the reduction of the disulfide bonds of insulin in the presence of dithiothreitol. These results indicate that an active thioredoxin is a major protein translocating in rice sieve tubes.