Notizen: We report successful fabrication and characteristics of submicron-size tunneling junctions using c-axis YBa2Cu3O7−y (YBCO) thin films of 800 nm thickness and Bi2Sr2CaCu2O8+δ(Bi-2212) single-crystal whiskers. The junctions were made using a three-dimensional focused-ion-beam etching method. First, a microbridge was patterned in a required junction width by normal direction etching. By tilting the sample stage up to 90°, two grooves on the bridge were etched from the lateral direction in order to create the required junction size. The 60 K YBCO junctions did not show any degradation of critical current density (Jc) down to an in-plane area of 0.5 μm2 and showed current–voltage (I–V) characteristics of the collective switching transition from the zero voltage state to the resistive state. For Bi-2212 stacks smaller than 1 μm2, we identified some of the features of charging effects on the I–V characteristics. © 2001 American Institute of Physics.

Notizen: We have observed that stress-induced leakage currents (SILC) in thin gate oxides (4.5 nm) could be reduced by applying a low gate bias to the oxides after stress, regardless of the polarity of the applied gate bias. The reduction of SILC increased with the applied gate bias and began to saturate after 105 s. In addition, the reduction of SILC was significantly enhanced in a hydrogen ambient, suggesting a strong link between the reduction of SILC and trapped-hole annealing. © 2000 American Institute of Physics.

Notizen: Downregulation of TGF-β receptors is implicated in colon cancer development. Inactivation of either of the two transmembrane serine/threonine kinases, TGF-β1 types I/II receptors, is now implicated in carcinogenesis, especially gastrointestinal carcinogenesis.〈section xml:id="abs1-2"〉〈title type="main"〉Methods:We generated transgenic mice, called pS2–dnRII or ITF–dnRII, of which the dominant negative mutant of the TGF-β type II receptor was expressed under the control of tissue-specific promoters, the pS2 promoter for stomach and ITF for intestine. They were either infected with H.pylori (ATCC 43504 strain, CagA+ and VacA+) or administered with azoxymethane to determine the significance of loss of TGF-β signalling in gastrointestinal carcinogenesis.〈section xml:id="abs1-3"〉〈title type="main"〉Results:Gastric adenocarcinoma developed in pS2–dnRII mice, whereas only chronic active gastritis was noted in wild-type littermates after 36 weeks of H.pylori infection. Mice lacking in TGF-β signalling specifically in the stomach showed a significantly higher proliferation cell nuclear antigen-labelling index when infected with H.pylori than wild-type littermates (P 〈 0.01). Development of colonic aberrant crypt foci was provoked in mice by intraperitoneal injections of azoxymethane, and ITF–dnRII mice showed significantly higher incidences of ACF and colon cancers than wild-type littermates.〈section xml:id="abs1-4"〉〈title type="main"〉Conclusions:Maintaining normal TGF-β signalling in the gastrointestinal tract seems to be important either for preventing abnormal mucosal proliferation, or for suppressing or retarding carcinogenesis.

Notizen: : From 5% w/v whey protein isolate (WPI), whey protein/lipid emulsion edible films were produced that were sorbitol- or glycerol-plasticized, containing butterfat (0.2% w/v) or candelilla wax (0.8% w/v). Thermal properties of the films determined by Differential Scanning Calorimetry (DSC) showed onset temperatures (To) of 126 to 127 °C for sorbitol- and 108 to 122 °C for glycerol-plasticized films. To values were used as the basis for heat sealing temperatures. Temperature (110, 120, 130 °C), pressure (296,445 kPa), and dwell time (1,3 s) affected seal strength. Optimum heat sealing temperature was 130 °C for sorbitol- and 110 °C for glycerol-plasticized films. All films were heat sealable with an impulse heat-sealer. Electron Spectroscopy for Chemical Analysis (ESCA) of the surfaces of both sealed and unsealed films showed increase in hydrogen and covalent bonds involving C-O-H and N-C, which may be the main forces responsible for the sealed joint formation of the films.

Notizen: : Whey protein isolate (5% w/v) films were plasticized with sorbitol or glycerol, and candelilla wax (0.8% w/ v) was added to produce whey protein isolate and candelilla wax emulsion edible films. The films were cut into 7.62 cm × 2.54 cm strips and evaluated by a 15-member trained sensory panel for milk odor, transparency/opaqueness, sweetness, and adhesiveness using a structured 9-point intensity scale. The films had no distinctive milk odor; however, they were perceived to be slightly sweet and adhesive by the trained sensory panel. Whey protein isolate films without candelilla wax were clear and transparent, whereas candelilla wax containing films were opaque.

Notizen: Experimentally induced wounds in animal models are useful in gaining a better understanding of the cellular and molecular processes of wound healing and in the initial evaluation of the safety and effectiveness of potential therapeutic agents. However, studying delayed healing has proven difficult in animals, whose wounds heal within a few days. In this report, we describe a novel method for establishing mouse wounds that require up to more than three weeks for complete closure, and we show the validity of this model in Smad3 null mice, which are known to display accelerated healing. Full-thickness wounds, measuring 0.3 by 1.0 cm, were made down to fascia on the dorsal aspect of the mouse tail in Smad3 KO mice and control littermates, approximately 1 cm distal to the body of the animal. The wounds were left to heal by secondary intention and were assessed histologically by computerized planimetry for wound closure at various times after wounding. These wounds in wild-type mice displayed delayed healing, with full closure occurring between 14 and 25 days after wounding. Complete closure of similar wounds in Smad3 null mice healed 30% faster (p 〈 0.01). By immunostaining with ki67, a marker for proliferation, Smad3 null animals also showed increased proliferation of dermal wound cells. Cultured dermal fibroblasts from Smad3 null mice showed increased baseline DNA synthesis and, interestingly, enhanced response to TGF-β1. By Western blot analysis, Smad3 null mice fibroblasts showed a compensatory increase in MAPK phosphorylation in response to TGF-β1, suggesting that MAPK overcompensation together with loss of Smad3 may be involved in the modulation of faster healing. We conclude that this novel tail wounding model can be useful for studying delayed or prolonged wound closure.Experimentally induced wounds in animal models can be useful in gaining a better understanding of the cellular and molecular processes of wound healing. Such models have also proven themselves valuable in the initial evaluation of the safety and effectiveness of potential therapeutic agents targeted for chronic non-healing wounds. (Gottrup, Agren et al. 2000). However, no ideal animal model exists which reliably reproduces delayed healing. In the mouse, a mammal whose genome has been completely cloned and which is easily manipulated genetically, wounds normally heal within a few days, and with a great deal of contraction. (Morris, Wu et al. 1997; Gottrup, Agren et al. 2000) There are models utilizing either genetically altered and inbred mice with certain characteristics that cause delayed healing. (Carmeliet 1995) However, it would be useful to have wound healing models that are applicable to most wild type mice used as controls and which would have a large enough window of observation before healing occurs. In this report, we describe a novel method for studying delayed healing in mice. This method utilizes full-thickness wounds made down to fascia on the dorsal and mostly hairless aspect of the mouse tail. The wounds are left to heal by secondary intention and assessed histologically by computerized planimetry for wound closure at various times after wounding. In this first report, the validity of the model was determined by studying control littermates and Smad3 null mice, which have been shown to display accelerated healing. The results shown here suggest that this is a useful model for studying delayed healing in mice.

Notizen: Background: We report a case of hypersensitivity pneumonitis (HP) in a 17-year-old male student caused by Fusarium napiforme found in his home environment. Methods: The patient was diagnosed according to history, chest radiograph, spirometry, high-resolution chest CT, and transbronchial lung biopsy. To identify the causative agent, cultured aeromolds were collected by the open-plate method. From the main fungi cultured, fungal antigens were prepared, and immunoblot analysis with the patient's serum and each fungal antigen was performed. Results: Five fungal species were isolated from the patient's home. Immunoblotting analysis with the patient's serum demonstrated more than 10 IgG-binding fractions to F. napiforme extract only, while little binding was noted with the other fungal antigens. Conclusions: We should be aware that HP may be caused by F. napiforme in the home environment.

Notizen: Aims:  PTEN is a recently identified tumour suppressor inactivated in a wide variety of human cancers, including endometrial cancers. Mutation of the PTEN tumour suppressor gene has been reported in approximately 50–83% of endometrial adenocarcinoma. Despite this fact, study of the expression of PTEN protein in human tumours is limited. PTEN protein functions as a tumour suppressor by regulating the cell cycle and survival through signal transduction pathway. PTEN protein was considered to have a dual-specificity phosphatase activity, but it is now known that its principal physiological activity is mainly derived from its lipid phosphatase activity. The cyclin-dependent kinase inhibitor, p27, has been suggested as a downstream target of cell cycle arrest of PTEN in various in vitro studies. In this study, we evaluated the alteration of PTEN protein expression in endometrial carcinoma and assessed its relationship to the expression of p27, the presumed downstream target of PTEN.Methods and results:  Immunohistochemical staining was performed on 66 cases of endometrial carcinoma including 61 endometrioid type and five serous type, using antibodies to PTEN and p27. Loss or decrease of PTEN expression was observed in 66% (40/61 cases) of uterine endometrioid carcinoma, whereas most uterine serous carcinoma (4/5 cases) showed intense PTEN expression. Four (30%) of 13 endometrial hyperplasia synchronous with endometrioid carcinoma demonstrated complete loss of PTEN expression. All endometrioid carcinoma synchronous with PTEN-negative endometrial hyperplasia showed loss of PTEN expression. Alteration of PTEN expression was not correlated with histological grade or stage. Decreased immunoreactivity of p27 was found in 48 cases (79%) of 61 endometrioid carcinoma, and 76% (36 cases) of them also showed loss or decrease of PTEN expression. Four of five uterine serous carcinoma revealed strong p27 immunoreactivity, all of which showed intense PTEN expression. A positive correlation between PTEN and p27 expression was statistically significant (Mantel–Haenszel χ2 test, P=0.001). Immunoreactivity of p27 was not related to histological grade and clinical stage.Conclusion:  These results show that PTEN and p27 are differentially expressed in endometrioid type carcinoma compared with those of the serous type, and suggest that the cyclin-dependent kinase inhibitor, p27, is a downstream target of PTEN-dependent cell cycle arrest in endometrial carcinoma.

Notizen: Capsaicin has been shown the different biologic and toxic effects on the non-neuronal celIs and serveral transformed cells. The present study aimed at evaluating the cytotoxic mechanism of capsacin on the cultured human skin fibroblast. Normal neonatal human fibroblasts were used for MTT assay to measure the changes of celI survival, while growth factors, receptor antagonist, antioxidants and calcium modulators were pretreated or co-treated with capsaicin. Fibroblast survival was significantly stimulated with EGF (10 ng/ml), bFGF (10 ng/ml) and capsazepine (10 µm) but inhibited by cycloheximide (1 µg/ml). When 200 µm capsaicin is given to fibroblasts, chromatin condensations were observed at 12 h, and cell survival rate was reduced to 25–50% at 24 h. Vanilloid receptor antagonists, capsazepine and ruthenium red did not prevent the toxic effect of capsaicin, and 10 µm capsazepine rather paradoxically enhanced the cytotoxicity. In contrast to bFGF (10 ng/ml), EGF (10, 100 ng/ml) enhanced the cytotoxicity of capsaicin. Neuropeptides, substance P (1, 10 nm) and CGRP (1, 10 nm), and a structural analogue to capsaicin, tyrosine (0.3–1.2 mm) did not affect the cytotoxicity. However, antioxidants trolox (100 µm) and ascorbic acid (0.1, 0.3 mm) reduced the capsaicin cytotoxicity. Of calcium-modulating agents, nifedifine, a Ca2+ channel blocker (10, 20 µm) and cyclopiazonic acid, a Ca2+-ATPase inhibitor in ER (10 µm) did not influence the cytotoxicity, but BAPTA/AM as a chelater for cytoplasmic free calcium ion (10 µm) significantly decreased capsaicin cytotoxicity. Unlike cycloheximide, a protein synthesis inhibitor, z-VAD-FMK, a non-specific caspase inhibitor, prevented the capsaicin cytotoxicity. The DNA ladder and TUNEL-positive cells were observed from the capsaicin-treated fibroblasts and Western blot revealed caspase-3 activity. Thus, capsaicin-induced cytotoxicity on human skin fibroblasts is more likely to suggest the mechanism of apoptotic pathway where antioxidants may play a role to prevent it.