Search

Elastic properties of B2‐Fe0.67Ni0.06Si0.27(15 wt.% Si) alloy have been investigated by combined high‐resolution inelastic X‐ray scattering and powder X‐ray diffraction in diamond anvil cells up to 100 GPa at room temperature. Densities (ρ), compressional (VP) and shear (VS) wave velocities were extrapolated to inner core conditions to enable comparison with the preliminary reference Earth model. The modeled aggregate compressional and shear wave velocities and densities of the two‐phase mixture of B2‐Fe0.67Ni0.06Si0.27and hcp‐Fe‐Ni are consistent with inner core PREM values of VP,VS, and ρbased on a linear mixing model with 30(5) vol % B2‐Fe0.67Ni0.06Si0.27and 70(5) vol % hcpFe‐Ni, which corresponds to ∼3–5 wt.% Si and ∼5–12 wt.% Ni. The composition of the inner core holds key information about how Earth evolved and how current processes such as the geomagnetic field work. Because the core cannot be directly sampled, our best estimates of its composition are based on the comparison of geophysical data with laboratory measurements of candidate materials. Decades of study have shown the inner core to be composed mainly of iron (with a minor amount of nickel) alloyed with one or more light elements, such as silicon. However, the effect of Si on the geophysical properties of Fe‐Ni alloys is not well established. In this study, we performed laboratory experiments to determine the density and sound velocity of Fe‐Ni‐Si alloy under extreme pressure conditions. We compared our results with seismological determinations and found that Earth's inner core can be accounted for by a mechanical mixture of cubic Fe‐Ni‐Si and hexagonal Fe‐Ni alloys. This mixture has a bulk composition of ∼3–5 weight % Si and ∼5–12 weight % Ni and is consistent with geophysical constraints. Sound velocities and densities of B2‐Fe‐Ni‐Si alloy are determined at high pressure, up to 100 GPa, using inelastic X‐ray scattering and X‐ray diffractionSeismologically observed compressional and shear wave velocities and density of Earth's inner core can be accounted for by a two‐phase mixture of 30 vol % B2‐Fe‐Ni‐Si and 70 vol % hcpFe‐Ni alloysExtrapolated results at inner core boundary conditions are consistent with an inner core composition containing ∼3–5 wt.% Si and ∼5–12 wt.% Ni Sound velocities and densities of B2‐Fe‐Ni‐Si alloy are determined at high pressure, up to 100 GPa, using inelastic X‐ray scattering and X‐ray diffraction Seismologically observed compressional and shear wave velocities and density of Earth's inner core can be accounted for by a two‐phase mixture of 30 vol % B2‐Fe‐Ni‐Si and 70 vol % hcpFe‐Ni alloys Extrapolated results at inner core boundary conditions are consistent with an inner core composition containing ∼3–5 wt.% Si and ∼5–12 wt.% Ni

The direct joining between AZ31B Mg alloy and MC Nylon 6 using friction lap welding (FLW) was performed over a wide range of welding parameters to clarify the effect of welding parameters on bubble formation for the purpose of obtaining high strength hybrid joints without bubbles. The volume of bubbles in the FLW joints was influenced by the amount of gases generated due to the pyrolysis of Nylon 6 and the amount of gases squeezed out of the joints during welding. An appropriate increase in welding speed, tool rotation rate and plunge depth can reduce the volume of bubbles. Strong FLW joint with area fraction of bubbles <8% was obtained after welding process optimisation.

The strain induced martensitic transformation (SMT) of the austenite stainless steel (SUS 304) under cyclic loading and static loading was investigated directly using electron backscattered diffraction. Two different SMT characteristics are observed, which are attributed to the differences of plastic and twinning deformation. The maximum cyclic stress has a strong influence on the SMT. The total area fraction of the Fe-a' phase increases significantly when the maximum cyclic load is >80 sUTS. In other words, the SMT is apparently absent when the samples are loaded with less than smax?=?70 sUTS, although such samples are fractured completely. Moreover, there is a clear Rratio effect on the SMT. For example, the loading condition R?=?-1 gives rise to a strong SMT compared to R?=?0·1 due to the more severe strain caused by the compressive stress. In contrast, no clear frequency effect (1 versus 30 Hz) on the SMT is detected, which may be attributed to the same maximum cyclic stress. Like the SMT characteristics under cyclic loading, the proportion of Fe-a' phase shows no clear increase until the sample is loaded statically to a tensile stress <70 sUTS.

Angiogenesis plays a pivotal role in many pathological processes including chronic liver diseases. Various factors, such as renin-angiotensin-aldosterone system (RAAS), insulin resistance (IR), and reactive oxygen species (ROS) contribute reciprocally to promote angiogenesis. Blockade of RAAS by angiotensin-converting enzyme inhibitor (ACE-I) or angiotensin II (AngII) receptor blocker (ARB) markedly attenuates liver fibrosis and hepatocellular carcinoma (HCC) along with suppression of angiogenesis, IR, and ROS. Aldosterone (Ald), a downstream component of AngII, is also involved in these processes, and a selective Ald blocker (SAB) significantly suppressed the progression of chronic liver diseases. The IR status itself has shown to directly accelerate the progression of chronic liver diseases whereas inhibition of ROS by iron chelator suppressed it through augmentation and inhibition of neovascularization. The combination therapy of ACE-I/ARB/SAB with other clinically used agents, such as interferon, imatinib mesylate, vitamin K, iron chelator, and branched-chain amino acids (BCAA) exerted more potent inhibitory effects on the development of liver fibrosis and HCC than the treatment using a single agent alone. Collectively, the anti-angiogenic treatment targeting RAAS, IR, ROS with clinically available agents may become a new therapeutic strategy against the progression of chronic liver diseases.

Angiogenesis is a complex and critical process essential for supporting the growth of hepatocellular carcinoma (HCC) as well as hepatocarcinogenesis. Recent studies have revealed that renin-angiotensin system (RAS) is involved in many types of cancer including HCC. Some studies have proven that suppression of angiotensin-II (AT-II) by a clinically used angiotensin-converting enzyme inhibitor (ACE-I) significantly attenuated the HCC growth and hepatocarcinogenesis along with down-regulation of a potent angiogenic factor; namely, the vascular endothelial growth factor (VEGF). When used in combination with the clinical available drugs such as interferon (IFN) and vitamin K (VK), ACE-I exerted more potent anti-tumor activities as compared with either single agent in addition to suppression of the intra-tumoral angiogenesis both in experimental models and clinical practice. It is well known that AT-II plays an important role in the insulin resistance (IR), and IR is reportedly involved in the progression of HCC. The combination of ACE-I and branched-chain amino acids (BCAA) exerted a marked chemopreventive effect against HCC under the condition of IR. In addition to AT-II, aldosterone (Ald), which plays a role in the downstream of AT-II, is also involved in the HCC development, and a clinically used selective Ald blocker (SAB) significantly suppressed the HCC growth and hepatocarcinogenesis. Since ACE-I, IFN, VK, BCAA, and SAB are already in widespread clinical use without any serious adverse effects, they may represent a potential new strategy for cancer therapy and chemoprevention against HCC especially in combination with other angiostatic agents.

Cyclo(l-β-3,7-dimethyloctylasparaginyl-l-phenylalanyl) (1) and cyclo(l-β-2-ethylhexylasparaginyl-l-phenylalanyl) (2), prepared from l-asparaginyl-l-phenylalanine methyl ester, have been found to be specialist gelators for ionic liquids. They can gel a wide variety of ionic liquids, including imizazolium, pyridinium, pyrazolidinium, piperidinium, morpholinium, and ammonium salts. The mean minimum gel concentrations (MGCs) necessary to make gels at 25 °C were determined for ionic liquids. The gel strength increased at a rate nearly proportional to the concentration of added gelator. The strength of the transparent gel of 1-butylpyridinium tetrafluoroborate ([C4py]BF4), prepared at a concentration of 60 g L^-1 (gelator 1/[C4py]BF4), was ca. 1500 g cm^-2. FT-IR spectroscopy indicated that a driving force for gelation was intermolecular hydrogen bonding between amides and that the phase transition from gel to liquid upon heating was brought about by the collapse of hydrogen bonding. The gels formed from ionic liquids were very thermally stable; no melting occurs up to 140 °C when the gels were prepared at a concentration of 70 g L^-1 (gelator/ionic liquid). The ionic conductivities of the gels were nearly the same as those of pure ionic liquids. The gelator had electrochemical stability and a wide electrochemical window. When the gels were prepared from ionic liquids containing propylene carbonate, the ionic conductivities of the resulting gels increased to levels rather higher than those of pure ionic liquids. The gelators also gelled ionic liquids containing supporting electrolytes.

Background: Bone remodeling laws have been used to simulate the movement of a single tooth, but the calculations for simulating the movement of several teeth simultaneously are time-consuming. The purpose of this article is to discuss a method that allows the simulation of more complex tooth movements. Methods: A 3-dimensional finite element method was used to simulate the orthodontic tooth movement (retraction) of a maxillary canine by sliding mechanics and any associated movement of the anchor teeth. Absorption and apposition of the alveolar bone were produced in proportion to the stress of the periodontal ligament. Results: In a reference case, the canine was retracted by a 2N force with 0.016-in square wire. The frictional coefficient between wire and bracket was 0.2. The movement of both the canine and the anchor teeth could be calculated with the elastic deformation of wire. The canine tipped during the initial unsteady state and then moved bodily during the steady state. It became upright when the orthodontic force was removed. The anchor teeth moved in the steady state and tipped in the mesial direction. The decrease in applied force by friction was about 70%. The tipping of the canine decreased when the wire size was increased or when the applied force was decreased. Conclusions: Simple assumptions were used in this calculation to simulate orthodontic tooth movements. The calculated results were reasonable in mechanical considerations. This method might enable one to estimate various tooth movements clinically. However, precise comparisons between calculated and clinical results, and the improvement of the calculation model, are left for a future study.

Background & Aims: Although a significant amount of regenerating gene (REG) I@a protein is present not only in normal gastric mucosa but also in gastric cancer tissues, its pathophysiologic role in gastric cancer development remains unclear. We investigated REG I@a protein expression in early gastric cancers, and examined whether cytokines are responsible for REG I@a gene expression and whether REG I@a protein has a trophic and/or an antiapoptotic effect on gastric cancer cells. Methods: Early gastric cancer specimens were analyzed histologically using immunohistochemistry for REG I@a protein and proliferating cell nuclear antigen (PCNA). The effects of cytokines on REG I@a promoter activity and its messenger RNA (mRNA) expression in AGS (a kind of gastric cancer cell line) cells were examined by luciferase reporter assay and Northern blot analysis, respectively. Effects of REG I@a protein on cell growth and H"2O"2-induced apoptosis in AGS cells were examined by 3,-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphatase nick-end labeling (TUNEL) assays, respectively. Results: REG I@a-positive early gastric cancers showed a significantly higher PCNA labeling index and more severe inflammatory cell infiltration in adjacent gastric mucosa than the negative cancers. REG I@a gene expression and its promoter activity were enhanced by interferon (IFN)-@c and interleukin (IL)-6. REG I@a protein promoted cell growth and cell resistance to H"2O"2-induced apoptosis in AGS cells. These effects were abolished by concomitant treatment with anti-REG I@a antibody. REG I@a protein enhanced Akt phosphorylation and Bcl-xL expression in AGS cells. Conclusions: REG I@a gene is inducible by cytokine stimulation and its gene product may function as a mitogenic and/or an antiapoptotic factor in the development of early gastric cancer.

Background & Aims: Endoscopic variceal ligation (EVL) therapy has been performed widely to treat or prevent variceal bleeding. We sought to examine the influence of EVL for esophageal varices on collateral vessels in the vicinity of gastric cardia. Methods: In 42 patients with esophagogastric varices, conventional endoscopy and endoscopic ultrasonography with a 20-MHz probe (CUP-EUS) were performed before and at every 3 months after EVL for esophageal varices. By using conventional endoscopy, cardial variceal sizes were divided into 3 grades: F0, F1, and F2. The sizes of submucosal, perforating, and paracardial vessels at the cardia also were classified into 3 grades according to CUP-EUS findings. Results: Conventional endoscopy showed cardial varices in 33 (79%) patients before and 23 (55%) patients at 3 months after the treatment (P < 0.05). CUP EUS showed that 29 (69%) patients had severe grade cardial submucosal vessels before EVL, but only 13 (31%) patients did after the treatment (P < 0.01). Nineteen (45%) patients had severe grade cardial perforating vessels before EVL, but only 4 (10%) patients did after the treatment (P < 0.001). Furthermore, patients with severe grade residual submucosal or perforating vessels at the cardia had shorter recurrence-free times of esophageal varices (P < 0.01, 0.05, respectively). Conclusions: Collateral vessels in the vicinity of gastric cardia were improved significantly after EVL, indicating that esophageal varices can be treated by EVL even though they connect with cardial varices. Furthermore, eradication of such collateral vessels by EVL may lead to longer recurrence-free status of esophageal varices.

AbstractChronic inflammation contributes to the pathogenesis of several complications of hemodialysis therapy. It is thought that backfiltration of bacteria-derived contaminations during dialysis may induce a chronic inflammatory state. High-sensitivity C-reactive protein (hs-CRP) is one of the tools which can take a hold on such a chronic inflammatory condition. We examined the effect of ultrapure dialysate which contributes to chronic inflammation with hs-CRP and tried to reduce endotoxin (ET) levels at the end of the dialysate from 70 EU/l to &lt;1.0 EU/l (ultrapure dialysate). Other dialysis conditions, except ET level, were fixed. We investigated the hs-CRP of 23 patients receiving regular dialysis before the use of ultrapure dialysate and 1 year after use of it prospectively. The data showed a significant decrease in the median value of the hs-CRP from 0.16 to 0.07 mg/dl (p &lt; 0.05). The value of serum β2-microglobulin decreased from 33.2 to 28.4 mg/dl (p &lt; 0.01) and the hemoglobin level increased from 10.0 to 11.0 g/dl (p &lt; 0.05). These results indicate that even a dialysate containing 70 EU/l of ET level may induce a chronic inflammatory state. hs-CRP is a very useful marker of chronic inflammation and the use of ultrapure dialysate is necessary to improve a chronic inflammatory state. The targeted ET level at the end of the dialysate should be set at ≤1.0 EU/l.Copyright © 2004 S. Karger AG, Basel

An equation of state for Mg(OH) 2 brucite under high-pressure and high-temperature conditions has been obtained by measuring temperature dependence of volume up to 600 K at ambient pressure and pressure dependence of volume up to 16 GPa at 300, 473, 673, and 873 K with in situ X-ray diffraction. Pressure dependence of entropy of brucite has been calculated with thermal expansion coefficient and volume which are derived from the present EoS. This dependence indicates that generation of secondary OH dipoles affects entropy. The OH dipoles probably appear around 2 GPa and the number seems not to change over 8 GPa at 300 K.

Abstract: A 69-year-old man with chronic alcoholic pancreatitis developed a left-sided massive pleural effusion. Magnetic resonance cholangiopancreatography clearly demonstrated the pancreatic cyst and the fistula connecting the cyst with the left pleural cavity, resulting in the diagnosis of pancreatic pleural effusion with a pancreaticopleural fistula. Conservative somatostatin analogue treatment completely eradicated the pancreatic pleural effusion and closed the pancreaticopleural fistula.

The binding isotherms for the interaction of sodium dodecyl sulfate (SDS) with poly(diallyldimethylammonium chloride) in aqueous solutions of 1,8-octanediol, 1,2-octanediol, or 1-butanol (BuOH) were determined by potentiometry, using a functional membrane responsive to anionic surfactants. Each alcohol caused the binding isotherm to shift to a lower SDS concentration. The magnitude of the effect was 1,2-octanediol > 1,8-octanediol ~ BuOH. The binding isotherms were analyzed by a linear lattice model for cooperative binding. The effect of the alcohols was analyzed by thermodynamic treatment of mixtures based on the regular mixing model, and the interchange energies between alcohol and water (4.06 kT for 1,8-octanediol, 4.82 kT for 1,2-octanediol, and 3.63 kT for BuOH) and between alcohol and SDS (−1.21 kT for 1,8-octanediol, −3.52 kT for 1,2-octanediol, and −1.65 kT for BuOH) were estimated. The pronounced effect of 1,2-octanediol on the binding isotherms was ascribed to its instability in the water phase and its strong hydrophobic interaction with the SDS anion in the polyion domain. The effect of 1,8-octanediol was comparable to that of BuOH, but 1,8-octanediol was more unstable in both the water phase and the polyion domain by about kT ln 2 compared to BuOH. This phenomenon can be attributed to the fact that binding of one 1,8-octanediol molecule structurally approximates the binding of two BuOH molecules.

The phase relations and equations of state of ZrO 2 and HfO 2 high-pressure polymorphs have been investigated by means of in situ observation using multi-anvil type high-pressure devices and synchrotron radiation. Baddeleyite (monoclinic ZrO 2 ) transforms to two distorted fluorite (CaF 2 )-type phases at 3-4 GPa depending on temperature: an orthorhombic phase, orthoI, below 600 °C and a tetragonal phase, which is one of the high-temperature forms of ZrO 2 , above 600 °C. Both orthoI and tetragonal phases then transform into another orthorhombic phase, orthoII, with a cotunnite (PbCl 2 )-type structure above 12.5 GPa and the phase boundary is almost independent of temperature. OrthoII is stable up to 1800 °C and 24 GPa. In case of HfO 2 , orthoI is stable from 4 to 14.5 GPa below 1250-1400 °C and transforms to the tetragonal phase above these temperatures. OrthoII of HfO 2 appears above 14.5 GPa and is stable up to 1800 °C at 21 GPa. The unit cell parameters and the volumes of these high-pressure phases have been determined as functions of pressure and temperature. The orthoI/tetragonal-to-orthoII transition of both ZrO 2 and HfO 2 is accompanied by about 9% volume decrease. The bulk moduli of orthoII calculated using Birch-Murnaghan's equations of state are 296 GPa and 312 GPa for ZrO 2 and HfO 2 , respectively. Since orthoII of both ZrO 2 and HfO 2 are quenchable to ambient conditions, these are candidates for super-hard materials.

OBJECTIVE: Kallmann syndrome is defined by the association of hypogonadotropic hypogonadism and anosmia. The KAL1 gene is responsible for the X-linked form of Kallmann syndrome. In this study we describe monozygotic twins with Kallmann syndrome due to the same mutation in the KAL1 gene. DESIGN: We studied male monozygotic twins with Kallmann syndrome. METHODS: We analyzed the KAL1 gene using the PCR-direct sequencing method. The twins' mother was examined for the identified mutation. RESULTS: We identified a 14 bp deletion from codon 419 in exon 9 (Pro419del14) in both KAL1 genes of the twins. This was a novel mutation in the KAL1 gene and was responsible for Kallmann syndrome. As Pro419del14 was not detected in the mother of the twins, Pro419del14 was a germline mutation originating from them. These monozygotic twins showed different LH and FSH responses to LH-RH stimulation and different phenotypes such as complications, physiques and psychiatric characters. CONCLUSIONS: We report an identical KAL1 gene mutation in the monozygotic twins with Kallmann syndrome. As these monozygotic twins showed different phenotypes in some respects, we suggest that factors other than mutations in the KAL1gene affect the symptomatic features of Kallmann syndrome.

Abstract:  Using the high-pressure differential thermal analysis (HP-DTA) system in a cubic multianvil high-pressure apparatus, we measured the melting points of portlandite, Ca(OH)2, up to 6 GPa and 1000 °C. We detected endothermic behavior at the temperature and pressure conditions of 800 °C and 2.5 GPa, 769 °C and 3.5 GPa, 752 °C and 4.0 GPa, 686 °C and 5.0 GPa, and 596 °C and 6.0 GPa, respectively, due to melting of portlandite. By in situ X-ray studies under pressure, the melting of portlandite was observed at 730 °C and 4.32 GPa and at 640 °C and 5.81 GPa, respectively. Results of both HP-DTA and X-ray studies were consistent within experimental error. The melting is congruent and has a negative Clapeyron slope, indicating that liquid Ca(OH)2 has higher densities than crystalline portlandite in this pressure range.

Background & Aims: Leukotrienes are proinflammatory mediators. Ethanol inhibits the catabolism of both cysteinyl leukotrienes (leukotriene E"4 [LTE"4] and N-acetyl-LTE"4) and leukotriene B"4 (LTB"4) in hepatocytes. We examined the metabolic derangement of leukotriene inactivation by ethanol in humans in vivo. Methods: LTE"4, N-acetyl-LTE"4, LTB"4, and 20-hydroxy-LTB"4 were quantified in urine samples from 16 patients with acute alcohol intoxication (mean blood ethanol, 75 mmol/L). In 9 healthy volunteers, urinary LTE"4 was determined before and after ethanol consumption (mean blood ethanol, 14 mmol/L). Results: The excretion of LTE"4 during alcohol intoxication was 286 compared with 36 nmol/mol creatinine in healthy subjects (P < 0.01); the corresponding values for N-acetyl-LTE"4 were 101 and 11 nmol/mol creatinine, respectively (P < 0.001). This excretion of cysteinyl leukotrienes decreased when the blood ethanol concentration returned to normal. LTB"4 and 20-hydroxy-LTB"4 were detectable only in patients with excessive blood ethanol concentrations (mean, 95 mmol/L). In healthy volunteers, LTE"4 excretion increased 3-5 hours after ethanol consumption (mean peak concentration of 1.5 nmol/L compared with 0.5 nmol/L for basal values; P < 0.005). Conclusions: Ethanol at high concentration induces increased leukotriene excretion into urine. These changes are consistent with inhibition of leukotriene catabolism and inactivation induced by ethanol, as well as with a higher leukotriene formation caused by ethanol-induced endotoxemia. GASTROENTEROLOGY 2000;118:1140-1148

Background & Aims: Heregulins (HRGs) regulate the proliferation and differentiation of various cell types. However, very little is known about their function in the gastrointestinal tract. The aim of this study was to investigate the role of HRGs on gastrointestinal cells. Methods: We examined the expression of erbB receptors and HRG-@a in human gastric cancer cell lines, rat gastrointestinal epithelial cells, and human gastric fibroblasts by Western blot analysis or reverse-transcription polymerase chain reaction. Receptor phosphorylation and heterodimerization induced by HRG-@a were detected by Western blot analysis. We also evaluated the in vitro effects of HRG-@a on cell proliferation and restitution. Results: Cancer cell lines and rat epithelial cells expressed erbB2 and erbB3, but protein expression of erbB4 was not detected. HRG-@a was detected only in gastric fibroblasts. HRG-@a activated tyrosine phosphorylation of epidermal growth factor receptor (EGFR), erbB2, and erbB3 and induced not only erbB3/erbB2 but also erbB3/EGFR and erbB2/EGFR heterodimer formation in MKN-28 cancer cells. Simultaneous cultivation of MKN-28 cells with gastric fibroblasts resulted in tyrosine phosphorylation of erbB3 in MKN-28 cells. HRG-@a also stimulated proliferation of MKN-28 cells and gastric epithelial cells. Conclusions: The data suggest that HRG-@a may affect epithelial cell proliferation through mesenchymal-epithelial interaction in the gastric mucosa. GASTROENTEROLOGY 1999;117:1119-1127

We studied ageing effects of Thin Gap Chambers (TGC). The gas mixture was 55% of CO2and 45% of n-pentane. The TGCs were irradiated with β-rays of a 90Sr source. The maximum hit rate per wire was 41–84kHz/cm. The gas flow rate was equivalent to replacing 0.3–2.6 of the TGC volume per minute. We observed neither significant deterioration on pulse height nor time jitter up to an accumulated charge of 1C/cm. We also performed a beam test to study the TGC performance under a high radiation environment. The maximum background rate of approximately 3.8MHz/cm2was achieved using a 90Sr source. The pulse height did not change significantly up to background rates of 100kHz/cm2.

Ag–Pd–Cu–Au type alloys are low cost dental alloys used widely for inlays, crowns, clasps, bars and bridges. The various kinds of fracture characteristics of Ag–Pd–Cu–Au type alloys should be evaluated with respect to microstructure to prevent the catastrophic failure of the dental products mentioned above. The fracture characteristics evaluation of Ag–Pd–Cu–Au type alloys with respect to microstructure has not been carried out very often. In particular, the number of reports on fracture characteristics evaluated based on the fracture mechanics with respect to microstructure is extremely small. The tensile fracture characteristics, fracture toughness based on the fracture mechanics, effects of alloying elements on fracture characteristics, and fatigue characteristics of dental Ag–Pd–Cu–Au type alloys are therefore described with respect to microstructure in this paper.

The interaction of antihistaminics, including mepyramine, with rat hepatic cytochrome P450s (P450s) was investigated. We first investigated mepyramine binding to eight forms of rat hepatic P450s. Mepyramine bound specifically to P450 2D1, which suggests that it inhibits P450 2D activity. Histamine H1 receptor antagonists (mepyramine, diphenhydramine, chlorpheniramine and triprolidine) inhibited the lidocaine 3-hydroxylation activity catalyzed by P450 2D1 but did not inhibit the testosterone hydroxylation activities catalyzed by P450s other than P450 2D forms. The Ki values of these antagonists for the catalytic activity of P450 2D1 were low and were similar to those of quinine and quinidine, which are specific inhibitors of P450 2D forms. The Ki value of mepyramine was especially low, at 34 nM. Furthermore, the effects of mepyramine on human P450 2D6 were investigated. Among the ten forms of human P450 expressed in yeast, mepyramine bound specifically to P450 2D6 in a binding assay. In human hepatic microsomes, mepyramine inhibited the debrisoquine 4-hydroxylation activity catalyzed by P450 2D6. These results indicate that histamine H1 receptor antagonists such as mepyramine are potent inhibitors of P450 2D forms because of their high affinity for these enzymes.

Determination of coagulation Factor XIII (F XIII)-related parameters in 21 patients with Henoch-Schönlein purpura documented a significant decrease of F XIII activity as well as of the F XIII-related antigenic determinants. Subgroup analysis with regard to the clinical symptoms showed an even further decrease of these parameters in patients with gastrointestinal complications. Stimulated by these findings a substitution therapy with a F XIII concentrate was initiated in those patients whose F XIII activity in plasma remained low and who developed severe abdominal pain accompanied by persisting gastrointestinal bleeding. This therapeutic approach not only corrected the laboratory data, but more important led to a cessation of pain and bleeding. A rapid decrease of F XIII levels after transfusion below 40 U/ml was indicative of relapse of abdominal symptoms, while increasing values were associated with the recovery of the patients. In conclusion: F XIII activity determinations appear to have a predictive value in patients with Henoch-Schönlein purpura, and the administration of F XIII concentrates may contribute to the improvement of gastrointestinal complications.

1,3,5,7-Tetramethylcyclotetrasiloxane (H4) was deposited on silica gel at 80°C by utilizing a chemical vapor deposition (CVD) method, where it was catalytically polymerized to form a surface coating of polymethylsiloxane (PMS). Treated silica gel (PMS-Si) increased in weight up to a plateau level, and there was no further increase with increasing reaction time. The film of PMS was partially cross linked; typical values of crosslinking ratio and film thickness were 2% and 0.6 nm, respectively. An anionic ion exchanger containing diethylamino groups was synthesized from PMS-Si by hydrosilylation of allyl glycidyl ether followed by treatment with diethylamine. Its structure was confirmed by13C and29Si CP/MAS NMR spectroscopy and FT-IR spectrophotometry. Characterization of silica gel (DEA-Si) modified with diethylamino group was evaluated by a packing of the column for liquid chromatography. As a mixture of five nucleotides was completely separated, it was recognized that DEA-Si was operated by ion exchange action. Because the surface of the silica gel was covered with hydrophobic PMS, the peak heights and retention times did not change after washing of the column with alkaline solution.

The string effect in QCD is investigated using data from the OPAL detector at LEP. By comparing the charged particle flow in three-jet multihadronic events with that in events with two jets and a hard isolated photon, the sensitivity to particular models is reduced. A comparison with various Monte Carlo models is presented. The difference in particle flows in the interquark region is found to be well reproduced by a leading order calculation of soft gluon emission, in the spirit of the Local Parton Hadron Duality hypothesis.