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Notizen: Co–P powders were produced by chemical reduction. The powders had a spherical shape with an average diameter of about 1 μm. X-ray diffraction and differential scanning calorimetry studies confirmed that the powders were amorphous. The amorphous powders showed higher saturation magnetization than the crystalline counterparts. Heat treatment of the powders above the crystallization temperature resulted in the formation of fcc Co, hcp Co, and Co2P phases. The saturation magnetization of the annealed powders monotonically decreased as the annealing temperature increased. On the other hand, the coercivity of the annealed powders rapidly increased with increasing annealing temperature. The powders annealed at 600 °C had a saturation magnetization of 100 emu/g with a coercivity of 500 Oe. © 2000 American Institute of Physics.

Notizen: A detailed experimental investigation of plasma fluctuation and its modification due to radial electric field effects, both its shear and curvature, has been carried out on the Current Sustained Torus IV at Nagoya University [Takamura et al., J. Plasma Fusion Res. 74, 38 (1998)] through measurement with an array of Langmuir probes. The observed statistical dispersion relation indicates a drift-wave-type turbulence. An examination of the radial electric field shear and curvature effects on the fluctuations as well as comparisons to theoretical predictions are presented. The decorrelation of turbulence is found to be influenced by the radial electric field shear in our experiment. A modification of the poloidal correlation length and the two-poloidal-point coherency due to the radial electric field has also been identified. Nonlinear analysis of quadratic mode coupling indicates that the radial electric field can affect the fluctuation amplitudes by modifying the coupling between different spectral components of the fluctuations. © 2000 American Institute of Physics.

Notizen: The frequency dependence of the tokamak plasma response to the externally applied rotating helical field was investigated by measuring the radial profile of the perturbation field with small magnetic probes which were inserted in the plasma. The experimental results are discussed, directly comparing with the generally accepted linear theory, and taking into account the E×B drift and diamagnetic effect of the plasma. It was found that the experimental results are in good agreement with the simple linear analysis based on the single helicity approximation in a cylindrical geometry, except for the ergodic region, which comes from the overlapping of several sideband components of the perturbation. It is also found that the radial component of the perturbation field is still amplified inside the resonance surface (r〈rs), even when a partial shielding takes place at r(approximate)rs. © 2000 American Institute of Physics.

Notizen: Abstract— The concentrations of metabolites which reflect energy production or use (P-creatine, ATP. ADP. 5′AMP, glucose, glycogen and lactate) and cyclic nucleotides (cyclic AMP and cyclic GMP) were measured in gerbil cortex during ischemia and recirculation. Bilateral ischemia of the gerbil brain was chosen as a model to ensure the assessment of short periods of ischemia without ambiguity. The metabolites and cyclic nucleotides were measured after, 1, 5. 20. 30 and 60 min of ischemia; and 1, 5, 30, 60 and 360 min after circulation was reestablished. The greatest changes in metabolites and cyclic nucleotides due to ischemia occurred during the 1st min; ischemia of longer duration had little further effect. However, the restoration of the metabolic profile was altered by the duration of the ischemic period. In general, the longer the period of ischemia, the slower the replenishment of high-energy phosphate compounds and energy sources. Cyclic AMP increased 5- to 13-fold during ischemia; cyclic GMP decreased to as little as one-fifth control values 60min after occlusion. During recirculation, cyclic AMP increased as much as 100-fold, while cyclic GMP increased up to 6-fold. The temporal derangements in cyclic nucleotide concentrations coincide with the loss and restoration of cortical activity; a possible mechanism has been suggested.

Notizen: Summary Background Pemphigus is an antidesmoglein (Dsg) autoimmune disease that is divided into two major subtypes: pemphigus foliaceus (PF) and pemphigus vulgaris (PV). We previously developed enzyme-linked immunosorbent assays (ELISAs) using recombinant Dsg1 and Dsg3 to detect IgG autoantibodies in patients with pemphigus. The protocol for the ELISAs was optimized for serological diagnosis, but under the conditions used, these assays were not particularly useful for monitoring disease activity in certain patients. That is, the sera from some patients with high-titre antibodies continued to show high index values in the ELISA after clinical improvement. Objectives In the study reported here, we modified the ELISA protocol to obtain ‘true’ index values that exhibit a better correlation with disease activity. Methods We tested two cases of pemphigus foliaceus (PF) and four cases of pemphigus vulgaris (PV), each with ELISA index values greater than 150 for Dsg1 or Dsg3. We ran an ELISA with sera from these patients serially diluted from 1 : 100 to 1 : 12,800. We then performed ELISA with a series of PV No. 1 sera diluted to 1 : 800 and PV No. 2–4 and PF No. 1–2 sera diluted to 1 : 1600, after which we plotted the ELISA index values against the time course of disease activity. Results In each of these cases, there was no apparent decline, over the course of the disease activity, in the ELISA index values at a serum dilution of 1 : 100, probably because the antigen–antibody reaction was saturated at that dilution. After running an ELISA with sera serially diluted from 1 : 100 to 1 : 12,800 we found that a linear dose-dependency between the dilution value and the index value was only observed when sera were diluted to 1 : 800 or more in one case (PV No.1) and to 1 : 1600 or more in the other five cases (PV No. 2–4, PF No. 1–2). After performing ELISA with these series as outlined above we plotted the ELISA index values against the time course of disease activity and found that the index values obtained from these appropriately diluted sera fluctuated in parallel with disease activity, and declined with clinical improvement. Conclusions These findings indicate that when appropriate dilutions are used in Dsg1 and Dsg3 ELISA, these assays can provide useful serological information for assessing disease activity in PF and PV.

Notizen: Background  Photodynamic therapy (PDT), which employs a combination of a tumour-localizing photosensitizer and visible light, has been used to treat superficial malignancies in the epidermis.Objectives  To examine histological changes and the role of apoptosis in lesions of actinic keratosis (AK) after PDT using 5-aminolaevulinic acid (ALA) and excimer dye laser.Methods  After topical ALA-PDT, biopsy specimens were collected from 18 skin lesions in 15 patients with AK. Paraffin-embedded sections of the skin specimens were stained with haematoxylin and eosin. The detection of apoptosis was performed using a terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labelling (TUNEL) method, antiactivated caspase-3 antibody and anti-Fas antibody.Results  One hour after PDT, cells with eosinophilic cytoplasm and markedly stained nuclei were found, and vacuolation of some tumour cells was noted in the lower layer of the epidermis. An infiltrate of lymphocytes and neutrophils was observed in the upper layer of the dermis. One day after PDT, all layers of the epidermis exhibited slightly degenerative necrosis, with shadow cell formation and chromatin condensation around the nuclear membrane in the lower layer of the epidermis. Necrosis in all layers of the epidermis and lymphocyte infiltration in the dermis were found 3 days after PDT. Tumour cells had disappeared and regenerative thickening of the epidermis was observed 7 days after PDT. TUNEL staining revealed apoptosis-positive cells in the epidermis in 8 of 11 specimens obtained 1 day after PDT. Activated caspase-3 expression was noted in the lower layer of the epidermis in four of these eight TUNEL-positive specimens.Conclusions  Results suggested that apoptosis is involved in tumour cell death after PDT in patients with AK, and that it occurs within 1 day after PDT.

Notizen: Helicobacter pylori eradication markedly improves histological inflammation and decreases peptic ulcer recurrence, but little is known about the subsequent development of gastric mucosal injury.〈section xml:id="abs1-2"〉〈title type="main"〉Aim:To investigate whether acid suppression treatment after eradication influences the development of gastric erosions.〈section xml:id="abs1-3"〉〈title type="main"〉Methods:Eighty-one patients (gastritis or peptic ulcer) after successful H. pylori eradication were divided into two groups: 40 received an H2-blocker for 6 months (H2-blocker-positive) and 41 received no treatment (H2-blocker-negative). Endoscopy was performed before, and at 3 and 6 months after completion of eradication.〈section xml:id="abs1-4"〉〈title type="main"〉Results:Cumulative prevalence of gastric erosions in the H2-blocker-positive group was significantly lower than in the H2-blocker-negative group, 25% vs. 42%, respectively. In the H2-blocker-negative group but not the H2-blocker-positive group, the cumulative prevalence of gastric erosions after eradication was higher in patients with less severe corpus atrophy or more severe corpus gastritis.〈section xml:id="abs1-5"〉〈title type="main"〉Conclusions:Development of gastric erosions after H. pylori eradication may be controlled by acid suppression treatment. Less severe atrophy or more severe gastritis in oxyntic glands before eradication may be involved in the development of gastric erosions. These results support the idea that recovery of acid secretion may be one of factors for development of gastric mucosal erosions after successful eradication.

Notizen: Aim : To investigate the effect of different proton pump inhibitors, S-mephenytoin 4′-hydroxylase (CYP2C19) genotype and antibiotic susceptibility on the eradication rate of Helicobacter pylori.Methods : One hundred and eighty-seven H. pylori-infected peptic ulcer patients were randomly treated with either rabeprazole (10 mg b.d.) or lansoprazole (30 mg b.d.) plus amoxicillin (750 mg b.d.) and clarithromycin (400 mg b.d.) for 1 week. The antibiotic susceptibility and CYP2C19 genotype (extensive or poor metabolizer) were investigated.Results : The eradication rates in the rabeprazole–amoxicillin–clarithromycin (RAC) and lansoprazole–amoxicillin–clarithromycin (LAC) groups were 75% and 69%, respectively, on an intention-to-treat basis, and 80% and 75%, respectively, on a per protocol basis. The eradication rate for clarithromycin-resistant strains was significantly lower than that for clarithromycin-sensitive strains (24% vs. 86%, P 〈 0.05). For clarithromycin-sensitive strains in the LAC group, there was a tendency for a lower eradication rate in extensive than poor metabolizers. The eradication rate in extensive metabolizers in the RAC group tended to be higher than that in extensive metabolizers in the LAC group (89% vs. 78%, P = 0.079726).Conclusions : The success of the 1-week proton pump inhibitor–amoxicillin–clarithromycin regimen depends on the susceptibility of H. pylori to clarithromycin. Moreover, differences in CYP2C19 genotype influence the eradication rates of lansoprazole-based therapy, and the rabeprazole-based regimen has an advantage especially in extensive metabolizers.

Notizen: The effect of Helicobacter pylori infection on non-steroidal anti-inflammatory drug-induced gastric mucosal injury is controversial.〈section xml:id="abs1-2"〉〈title type="main"〉Aim:To examine the effect of the interaction between H. pylori and non-steroidal anti-inflammatory drugs on gastric mucosal injury.〈section xml:id="abs1-3"〉〈title type="main"〉Methods:Mongolian gerbils infected with H. pylori were treated with indometacin at 8 mg/kg for 2 days or 7 days. Mucosal damage was assessed by macroscopic and histological examination, and myeloperoxidase activity was measured as an index of neutrophil infiltration. The expression levels of cyclo-oxygenase proteins were determined by Western blot analysis and cyclo-oxygenase activity.〈section xml:id="abs1-4"〉〈title type="main"〉Results:A 2-day course of indometacin did not cause an increase in gastric damage in H. pylori-infected Mongolian gerbils compared to uninfected gerbils, while a 7-day course of indometacin caused additive gastric damage in H. pylori-infected animals. H. pylori infection induced cyclo-oxygenase-2 expression in the stomach. Treatment with indometacin for 2 days did not significantly affect cyclo-oxygenase activity in H. pylori-infected animals, while treatment for 7 days inhibited both cyclo-oxygenase-1 and cyclo-oxygenase-2 activities. Pre-treatment with a selective cyclo-oxygenase-2 inhibitor aggravated mucosal injury in H. pylori-infected animals treated or not treated with indometacin for 2 days.〈section xml:id="abs1-5"〉〈title type="main"〉Conclusions:Our results suggest that cyclo-oxygenase-2 protein induced by H. pylori infection may be involved in the defence of the gastric mucosa against damage caused by non-steroidal anti-inflammatory drugs. Therefore, inhibition of cyclo-oxygenase-2 activity may enhance non-steroidal anti-inflammatory drug-caused gastric damage in H. pylori-infected animals.