Characterization of Magnesium Sulfate as an Antiarrhythmic Agent

Background

Recently, intravenous magnesium therapy has been used for the treatment of ventricular arrhythmias, but data to establish a causal link between the electrophysiological properties and the antiarrhythmic actions are lacking.

Methods and Results

The acute antiarrhythmic effect of magnesium sulfate was assessed using epinephrine-, digitalis-, and coronary ligation-induced canine ventricular arrhythmia models. The intravenous administration of magnesium sulfate (100 mg/kg) reduced the incidence of the ventricular arrhythmias of all models. The antiarrhythmic effect on the epinephrine-induced arrhythmia was potent and long-lasting, while those on the other arrhythmia models were weak and transient. The direct cardiovascular effects were assessed using the canine isolated, blood-perfused sinus node, papillary muscle, and atrioventricular node preparations. The intracoronary administration of magnesium sulfate (0.1–30 mg) suppressed sinoatrial automaticity and ventricular contraction, while it increased atrio-His and His-ventricular conduction time, coronary blood flow, and the duration of monophasic action potential in a dose-dependent manner. The effects on His-ventricular conduction and monophasic action potential duration were less potent compared with the other cardiovascular effects.

Conclusion

These results suggest that magnesium sulfate possesses multiple electrophysiological properties and that the effects related to the calcium channel inhibition may be the most relevant for the antiarrhythmic actions.

Cytokine-related and sodium channel polymorphism as candidate predisposing factors for childhood encephalopathy FIRES/AERRPS

Febrile infection-related epilepsy syndrome (FIRES), or acute encephalitis with refractory, repetitive partial seizures (AERRPS), is an epileptic encephalopathy beginning with fever-mediated seizures. The etiology remains unclear. To elucidate the genetic background of FIRES/AERRPS (hereafter FIRES), we recruited 19 Japanese patients, genotyped polymorphisms of the IL1B, IL6, IL10, TNFA, IL1RN, SCN1A and SCN2A genes, and compared their frequency between the patients and controls. For IL1RN, the frequency of a variable number of tandem repeat (VNTR) allele, RN2, was significantly higher in the patients than in controls (p=0.0067), and A allele at rs4251981 in 5' upstream of IL1RN with borderline significance (p=0.015). Haplotype containing RN2 was associated with an increased risk of FIRES (OR 3.88, 95%CI 1.40-10.8, p=0.0057). For SCN1A, no polymorphisms showed a significant association, whereas a missense mutation, R1575C, was found in two patients. For SCN2A, the minor allele frequency of G allele at rs1864885 was higher in patients with borderline significance (p=0.011). We demonstrated the association of IL1RN haplotype containing RN2 with FIRES, and showed a possible association of IL1RN rs4251981 G>A and SCN2A rs1864885 A>G, in Japanese patients. These preliminary findings suggest the involvement of multiple genetic factors in FIRES, which needs to be confirmed by future studies in a larger number of FIRES cases.

Assessing the risk of observing multiple generations of Middle East respiratory syndrome (MERS) cases given an imported case

To guide risk assessment, expected numbers of cases and generations were estimated, assuming a case importation of Middle East respiratory syndrome (MERS). Our analysis of 36 importation events yielded the risk of observing secondary transmission events at 22.7% (95% confidence interval: 19.3–25.1). The risks of observing generations 2, 3 and 4 were estimated at 10.5%, 6.1% and 3.9%, respectively. Countries at risk should be ready for highly variable outcomes following an importation of MERS.

STAT3 integrates cooperative Ras and TGF-β signals that induce Snail expression

The epithelial-mesenchymal transition (EMT) is a crucial morphological event that occurs during the progression of epithelial tumors. EMT can be induced by transforming growth factor β (TGF-β) in certain kinds of cancer cells through the induction of Snail, a key regulator of EMT. We have previously found that TGF-β remarkably induces Snail expression in cooperation with Ras signals; however, the underlying mechanism of this synergism has not yet been determined. Here, we demonstrate that signal transducer and activator of transcription 3 (STAT3) acts as a mediator that synergizes TGF-β and Ras signals. The overexpression of STAT3 enhanced Snail induction, whereas siRNA-mediated knockdown of STAT3 inhibited it. The STAT3-YF mutant, which has Tyr 705 substituted with Phe, did not enhance Snail induction. Several STAT3 mutants lacking transcriptional activity also failed to enhance it; however, the putative STAT3-binding elements in the Snail promoter regions were not required for STAT3-mediated Snail induction. Protein inhibitor of activated STAT3 (PIAS3) inhibited the enhanced Snail promoter activity induced by TGF-β and Ras. The interaction between PIAS3 and STAT3 was reduced by TGF-β in cells harboring oncogenic Ras, whereas TGF-β promoted the binding of PIAS3 to Smad3, a crucial mediator of TGF-β signaling. Therefore, these findings suggest that STAT3 enhances Snail induction when it is dissociated from PIAS3 by TGF-β in cooperation with Ras signals.

Sialyl-lewis-x antigen immunoreaction of colorectal-cancer and its relationship to hematogenous metastasis

The adhesion of cancer cells to endothelial cells of the target organ is one of the most important steps of hematogenous metastasis. Especially, sialyl Le(X) plays an important role in defining the metastasis. The expression of sialyl Le(X) antigen in colorectal cancer and its usefulness not only as an indicator of metastatic potential but also as a prognostic factor was studied immunohistochemically. Fifty-five (32.4%) sialyl Le(X) antigen-positive tumors were found in 170 colorectal cancers. There was a significant correlation between the expression of sialyl Le(X) antigen and the histological tumor type, venous invasion, lymph node metastasis, as well as liver metastasis. Hematogenous metastases were significantly more frequent in patients with sialyl Le(X)-positive tumor than in those with sialyl Le(X)-negative tumor; and prognosis was significantly poorer in the former. The results suggest that sialyl Le(X) antigen plays a role in hematogenous metastasis of colorectal cancer, and that the expression of sialyl Le(X) is associated with poor prognosis.

TGF-β drives epithelial-mesenchymal transition through δEF1-mediated downregulation of ESRP

Epithelial-mesenchymal transition (EMT) is a crucial event in wound healing, tissue repair and cancer progression in adult tissues. We have recently shown that transforming growth factor (TGF)-β-induced EMT involves isoform switching of fibroblast growth factor receptors by alternative splicing. We performed a microarray-based analysis at single exon level to elucidate changes in splicing variants generated during TGF-β-induced EMT, and found that TGF-β induces broad alteration of splicing patterns by downregulating epithelial splicing regulatory proteins (ESRPs). This was achieved by TGF-β-mediated upregulation of δEF1 family proteins, δEF1 and SIP1. δEF1 and SIP1 each remarkably repressed ESRP2 transcription through binding to the ESRP2 promoter in NMuMG cells. Silencing of both δEF1 and SIP1, but not either alone, abolished the TGF-β-induced ESRP repression. The expression profiles of ESRPs were inversely related to those of δEF1 and SIP in human breast cancer cell lines and primary tumor specimens. Further, overexpression of ESRPs in TGF-β-treated cells resulted in restoration of the epithelial splicing profiles as well as attenuation of certain phenotypes of EMT. Therefore, δEF1 family proteins repress the expression of ESRPs to regulate alternative splicing during TGF-β-induced EMT and the progression of breast cancers.

New anomaly in the transverse acoustic impedance of superfluid 3He-B with a wall coated by several layers of 4He

We measured the transverse acoustic impedance of superfluid 3He-B with a wall coated by several layers of 4He. The coating is known to enhance the specularity in quasiparticle scattering by the wall. We found a new anomaly, a bump and a peak, in the temperature dependence of the transverse acoustic impedance. This agrees with a theoretical calculation using a partially specular wall boundary condition. The new anomaly is shown to arise from a change in the surface density of states by coating and the scattering of thermally occupied surface bound states to other states. The change is towards the density of states of Majorana cone in the specular limit.

First-principles calculation of oxygen K-electron energy loss near edge structure of HfO(2)

Oxygen K-electron energy loss near edge structures (ELNES) of monoclinic, tetragonal, and cubic HfO(2) were calculated by the first-principles full-potential augmented plane wave plus local orbitals (APW+lo) method. By considering the relativistic effect as well as the core-hole effect in the calculation, the experimental oxygen K ELNES was successfully reproduced. The first, second, third, and fourth peaks originate from oxygen p components hybridized with Hf d-e(g), d-t(2g), s, and p components, respectively. It was found that the spectral differences among the polymorphs are mainly caused by the local structure of the Hf in the crystal.

A case of primary erythermalgia, wintry hypothermia and encephalopathy

Primary erythermalgia is a rare neuropathy characterized by attacks of burning pain and redness in the extremities in response to warm stimuli. We describe here a boy with erythermalgia whose painful attacks began in infancy. We found a novel mutation of SCN9A, which is a responsible gene for primary erythermalgia in this case. In his teens, he developed wintry hypothermia with resultant neurological dysfunction and recurrent pneumonia. During the course of pneumonia, he had transient encephalopaty with a reversible lesion in the splenium of the corpus callosum. In addition to excessive cooling, a defect in central thermoregulation may have caused hypothermia in this patient.

Gene targeting by homologous recombination as a biotechnological tool for rice functional genomics

The modification of an endogenous gene into a designed sequence by homologous recombination, termed gene targeting (GT), has broad implications for basic and applied research. Rice (Oryza sativa), with a sequenced genome of 389 Mb, is one of the most important crops and a model plant for cereals, and the single-copy gene Waxy on chromosome 6 has been modified with a frequency of 1% per surviving callus by GT using a strong positive-negative selection. Because the strategy is independent of gene-specific selection or screening, it is in principle applicable to any gene. However, a gene in the multigene family or a gene carrying repetitive sequences may preclude efficient homologous recombination-promoted GT due to the occurrence of ectopic recombination. Here, we describe an improved GT procedure whereby we obtained nine independent transformed calli having the alcohol dehydrogenase2 (Adh2) gene modified with a frequency of approximately 2% per surviving callus and subsequently isolated eight fertile transgenic plants without the concomitant occurrence of undesirable ectopic events, even though the rice genome carries four Adh genes, including a newly characterized Adh3 gene, and a copy of highly repetitive retroelements is present adjacent to the Adh2 gene. The results indicate that GT using a strong positive-negative selection can be widely applicable to functional genomics in rice and presumably in other higher plants.

Fulde-Ferrell-Larkin-Ovchinnikov state in a perpendicular field of quasi-two-dimensional CeCoIn5

A Fulde-Ferrell-Larkin-Ovchinnkov (FFLO) state was previously reported in the quasi-2D heavy fermion CeCoIn5 when a magnetic field was applied parallel to the ab plane. Here, we conduct 115In NMR studies of this material in a perpendicular field, and provide strong evidence for FFLO in this case as well. Although the topology of the phase transition lines in the H-T phase diagram is identical for both configurations, there are several remarkable differences between them. Compared to H parallelab, the FFLO phase for H perpendicularab is confined in a much narrower region at the low-T-high-H corner in the H-T plane, and the critical field separating the FFLO and non-FFLO superconducting states almost ceases to have a temperature dependence. Moreover, directing H perpendicularab results in a notable change in the quasiparticle excitation spectrum within the planar node associated with the FFLO transition.

Chemical removal and recovery of phosphorus from excess sludge in a sewage treatment plant

We describe a process for the recovery of phosphorus from excess sludge in a sewage treatment plant that currently uses polyaluminium chloride for chemical phosphorus removal. Instead, we employed alkaline dissolution of excess sludge with calcium phosphate precipitation to recover phosphorus from sewage. The recovery ratio for phosphorus from sewage using the phosphorus recovery system is approximately 50%. In addition, the amount of excess sludge in the phosphorus recovery system is approximately half that of conventional chemical phosphorus removal. Alkaline dissolution of excess sludge resulted in dissolution of aluminium into the supernatant. Furthermore, since dissolved aluminium can be reused as a coagulant, the phosphorus recovery system could be used to economize coagulant consumption. Operation and maintenance costs of the phosphorus recovery system are 25.9 U.S. cents per 1 m3 of sewage compared to 32.0 U.S. cents per 1 m3 of sewage for conventional chemical phosphorus removal, representing a decrease of 20% in the operation and maintenance costs.

Isolation of cDNAs for R2R3-MYB, bHLH and WDR transcriptional regulators and identification of c and ca mutations conferring white flowers in the Japanese morning glory

The transcriptional regulators for anthocyanin biosynthesis include members of proteins containing an R2R3-MYB domain, a bHLH (basic helix-loop-helix) domain and conserved WD40 repeats (WDRs). Spacial and temporal expression of the structural genes encoding the enzymes for anthocyanin biosynthesis is thought to be determined by combinations of the R2R3-MYB, bHLH and WDR factors and their interactions. While the wild-type Japanese morning glory (Ipomoea nil) exhibits blue flowers with colored stems and dark-brown seeds, the c mutants display white flowers with red stems and colored seeds, and the ca mutants exhibit white flowers with green stems and ivory seeds. Here, we characterize the tissue-specific expression of three MYB genes, three bHLH genes and two WDR genes in I. nil. We also show that the recessive c-1 and ca alleles are frameshift mutations caused by a 2 bp deletion and 7 bp insertions in the genes for the R2R3-MYB and WDR transcriptional regulators designated as InMYB1 and InWDR1, respectively. In addition to defects in flower, stem and seed pigmentations, the ca mutants were found to show reduced trichome formation in seeds but to produce leaf and stem trichomes and root hairs normally. Except for the gene for chalcone synthase E in the ca mutant, all structural genes tested were coordinately reduced in both c-1 and ca mutant flower limbs. However, slight but significant expression of the genes for chalcone synthase D, chalcone isomerase and flavanone 3-hydroxylase in the pathway for flavonol biosynthesis was detectable in c-1 and ca mutants, whereas no such residual expression could be observed in other genes involved in the later anthocyanin biosynthesis pathway. The biological roles of the C-1 and Ca genes in I. nil epidermal traits and their evolutionary implications are also discussed.

Execution of BMP-4-induced apoptosis by p53-dependent ER dysfunction in myeloma and B-cell hybridoma cells

Bone morphogenic protein (BMP)-4 inhibits proliferation and induces the apoptosis of myeloma cells. However, little is known about the molecular mechanisms of how BMP-4 executes this apoptosis. In this report, we investigated the roles of p53 and the endoplasmic reticulum (ER) in BMP-4-induced apoptosis of mouse hybridoma HS-72 cells. We found that 3 ng/ml of BMP-4 is sufficient to induce the expression of proapoptotic proteins, puma and bax, in a p53-dependent mechanism, and facilitate Ca(2+) release from the ER to the cytosol, resulting in the activation of caspase-12 and ER dysfunction. Similarly to HS-72 cells, multiple myeloma cells with wild-type p53 genes show much higher sensitivity to BMP-4-induced apoptosis than cells without wild-type p53 genes, suggesting that wild-type p53 status is required for dysfunction of the ER during BMP-4-induced apoptosis in ER-enriched cells, such as hybridoma and myeloma cells. These findings demonstrate that the presence of wild-type p53 genes and enrichment of the ER determines the sensitivity to effective apoptosis by BMP-4, and suggest that ER stress-inducing agents would be valuable in the treatment of multiple myeloma.

Characteristics of an ammonia-oxidizing bacterium with a plasmid isolated from alkaline soils and its phylogenetic relationship

An ammonia-oxidizing bacterium, strain TCH716, was isolated from alkaline soil at Harbin city, China. The cells of strain TCH716 are lobate (0.8-1.5 x 1.0-2.0 microm), gram-negative, obligately aerobic, and nonmotile. Colonies (1-2 mm in diameter) on gellan gum plate culture are reddish, circular, and smooth. The G + C content of DNA is 54.78 mol%. Its percentage of 16S rRNA gene sequence similarity (%) to Nitrosolobus multiformis ATCC 25196T (type strain) is 98.56%. This bacterium has an optimal growth temperature and pH at 30 degrees C and 8.0-8.5, respectively. The concentration of ammonium sulfate in the HEPES medium for optimum growth of this bacterium is 38 mM. Strain TCH716 was found to have a plasmid (approximately 6.5 kbp) that possessed a plasmid-linked gene for sulfonamide resistance. Phosphoglycerate kinase, RubisCO and PEPC were found to possess high specific activities compared to the activities of these enzymes in strain ATCC 25978T. In identification of strain TCH716, both morphological characteristics (compartmentalized cells) and the phylogenetic relationship based on 16S rRNA gene sequence are important. Based on results obtained, strain TCH716 belongs to the genus Nitrosolobus, and designated as Nitrosolobus sp. TCH716.

A role for Id in the regulation of TGF-beta-induced epithelial-mesenchymal transdifferentiation

Epithelial-mesenchymal transdifferentiation (EMT) is a critical morphogenic event that occurs during embryonic development and during the progression of various epithelial tumors. EMT can be induced by transforming growth factor (TGF)-beta in mouse NMuMG mammary epithelial cells. Here, we demonstrate a central role of helix-loop-helix factors, E2A and inhibitor of differentiation (Id) proteins, in TGF-beta-induced EMT. Epithelial cells ectopically expressing E2A adopt a fibroblastic phenotype and acquire migratory/invasive properties, concomitant with the suppression of E-cadherin expression. Id proteins interacted with E2A proteins and antagonized E2A-dependent suppression of the E-cadherin promoter. Levels of Id proteins were dramatically decreased by TGF-beta. Moreover, NMuMG cells overexpressed Id2 showed partial resistance to TGF-beta-induced EMT. Id proteins thus inhibit the action of E2A proteins on the expression of E-cadherin, but after TGF-beta stimulation, E2A proteins are present in molar excess of the Id proteins, thus over-riding their inhibitory function and leading to EMT.

Observation of surface Andreev bound States of superfluid 3He by transverse acoustic impedance measurements

Complex transverse acoustic impedance of the superfluid (3)He-B was measured at the frequencies of 10 to 80 MHz at 17.0 bar by a cw bridge method. The observed temperature dependence was well explained by the quasiclassical theory with random S-matrix model for a diffusive surface. The temperature dependence was influenced by pair breaking and by quasiparticle density of states at the surface, which was drastically modified from the bulk one by the presence of surface Andreev bound states.

Identification and frequency of a new HLA-A allele, A*030104

We here identified a novel HLA-A allele, A*030104, which was found in a Japanese family. The direct sequencing revealed that A*030104 was identical to A*030101 except for a nucleotide substitution of GAG to GAA at codon 63 without an amino acid replacement. The frequencies of A*030104 and A*0301 including A*030104 in Japanese population (n = 22,360) were approximately 0.013 and 0.40%, respectively.

Texture in the superconducting order parameter of CeCoIn5 revealed by nuclear magnetic resonance

We present a 115In NMR study of the quasi-two-dimensional heavy-fermion superconductor CeCoIn5 believed to host a Fulde-Ferrel-Larkin-Ovchinnikov (FFLO) state. In the vicinity of the upper critical field and with a magnetic field applied parallel to the ab plane, the NMR spectrum exhibits a dramatic change below T*(H) which well coincides with the position of reported anomalies in specific heat and ultrasound velocity. We argue that our results provide the first microscopic evidence for the occurrence of a spatially modulated superconducting order parameter expected in a FFLO state. The NMR spectrum also implies an anomalous electronic structure of vortex cores.

Positive association of CYP11B2 gene polymorphism with genetic predisposition to essential hypertension

Predispositions to essential hypertension and cardiovascular diseases are possibly associated with gene polymorphisms of the renin-angiotensin system. Gene polymorphisms of angiotensinogen and angiotensin-converting enzyme genes have been suggested to be risk factors for hypertension and myocardial infarction. Concerning the polymorphism of aldosterone synthase (CYP11B2) gene, earlier studies have shown inconsistent results in terms of its relation to hypertension. In the present case-control study, we investigated the association of -344T/C polymorphism in the promoter region of human CYP11B2 gene with genetic predisposition to hypertension. The genotype of -344T/C polymorphism was determined in essential hypertension subjects (n=250) and normotensive subjects (n=221). The distributions of three genotypes (TT, TC, and CC) were significantly different between the hypertensive and the normotensive groups (chi(2)=9.61, P=0.008). Namely, the frequency of C allele was higher in the hypertensive patients than in the normotensive subjects (34.2 vs 26.5%, P=0.010). Our data suggest that the -344C allele of CYP11B2 gene polymorphism is associated with the genetic predisposition to develop essential hypertension.

New mathematical model for accurate description of absorption kinetics of paracetamol given orally with a high calorie liquid meal

OBJECTIVE

Gastric emptying (GE) of liquids is quantified as the rate of paracetamol absorption in clinical and research settings (paracetamol method). A conventional 1-compartment model assumes the first-order rate kinetics for paracetamol absorption. This assumption seems improper when paracetamol is coingested with a caloric liquid meal, because the caloric liquid leaves the stomach at a constant rate (zero-order process). Theories based on the 1-compartment model reveal that tmax and Cmax/AUCinfinity accurately reflect the rate of paracetamol absorption, but whether this is also the case when paracetamol is administered with a caloric liquid, has not been investigated. The aims of this study were to propose a new mathematical model for accurately describing absorptive behaviors of paracetamol added to a caloric liquid meal, and, using the model, to clarify the characteristics of tmax and Cmax/AUCinfinity as rate parameters.

METHODS

Based on the newly developed model, tamx and Cmax/AUCinfinity were mathematically expressed in terms of GE rates. Subsequently, the characteristics of tmax and Cmax/AUCinfinity were elucidated by simulation works.

RESULTS

The simulation study showed that both tamx and Cmax/AUCinfinity could reflect GE rates, tmax was a more sensitive index of GE than Cmax/AUCinfinity and tmax was less reliable than Cmax/AUCinfinity if GE is very rapid.

CONCLUSIONS

In the paracetamol method using a caloric liquid test meal, tmax and Cmax/AUCinfinity are suitable for detecting delayed and rapid GE, respectively.

[Postintubation tracheal stenosis; problems associated with choice of management]

We experienced a case with tracheal stenosis due to postintubation damage, or so-called cuff stenosis. A 50-year-old man who attempted suicide by pounding nails into his head and chest using carpenter's tools was treated by endotracheal intubation and immediately underwent emergency surgery in July 2000. The patient was placed on artificial ventilation with oral endotracheal intubation, and a tracheostomy was performed 4 days after the operation. After that, his respiration recovered and he was weaned from the respirator. He was discharged 22 days after surgery with no respiratory symptoms. Two days after discharge, he complained of wheezing and dyspnea. Medical examination revealed that the cervical trachea had a severe circumferential stenosis 2.5 cm from the second tracheal cartilage. On retrospective inspection, the region of stenosis was compatible with the cuff site of the endotracheal tube used for the emergency operation. At first we tried nonoperative treatment, considering his mental state. However, we found that surgical treatment was ultimately necessary. A 2.5 cm sleeve resection of the trachea (5 tracheal cartilage rings) was performed, followed by end-to-end suture using 21 stitches with 4-0 MEDIFIT C thread. Pathologically, the surgical specimen showed degeneration and necrosis of tracheal cartilage with excessive growth of granulation tissue. These findings revealed that the etiologic basis of the tracheal stenosis was attributed to pressure necrosis by the cuff. The postoperative course was uneventful. Sixteen months after the surgery, the granulation tissue had not recurred, and problematic stenosis was not visible in the trachea. In this report, we discussed a reasonable management of postintubation tracheal stenosis. Tracheoplasty has been proposed as the most reliable method for treating tracheal stenosis. However, the best treatment in each case is still somewhat controversial because various nonoperative treatment methods are recently available, including laser phototherapy, argon plasma coagulation, mechanical dilatation, stent replacement, and drug treatment. Therefore, it is very important to judge properly the absolute indication for surgical treatment. If granulations are removed successfully by the above-described nonoperative methods, attempts at repair lead only to regrowth of granulation tissue as long as there is necrotic tracheal cartilage. Thus, the determinant of treatment methods is whether postintubation damage extends to tracheal cartilage or not. For now, there is no accurate diagnostic study for viability of cartilage preoperatively. In the literature, symptoms due to airway stenosis occurred rapidly within one month in the case of patients with necrosis of tracheal cartilage. We concluded that the period between extubation and development of symptoms is very informative in the management of postintubation tracheal stenosis. Surgical approaches should be selected for a patient with a rapid and progressive course after extubation when the patient can tolerate it.

Amicrobial pustular dermatosis in two patients with immunological abnormalities

We report two patients with severe amicrobial pustular dermatosis with immunological abnormalities: a 63-year-old woman with a 30-year-history of discoid lupus erythematosus and sicca syndrome, and a 35-year-old woman with high levels of gamma-globulinemia and positive antinuclear antibodies. Both patients presented with crusty and eroded erythematous plaques studded with aseptic pustules on the back, face, and scalp. Histological examination showed acanthosis, neutrophilic exocytosis to the epidermis, and neutrophilic and lymphocytic infiltration with nuclear dust in the dermis. These patients were diagnosed as having "amicrobial pustulosis associated with autoimmune diseases". The eruptions improved with combination treatment of oral prednisolone with cyclosporin A or diaminodiphenylsulphone. Although the pathogenesis remains unclear, amicrobial pustular dermatosis might be one of the cutaneous complications in autoimmune diseases.

Cerebral artery selective inhibition of protein kinase c-mediated contraction by hns-32, a novel azulene-1-carboxamidine derivative

The vasorelaxant actions of a novel azulene-1-carboxamidine derivative, HNS-32, were investigated on the tension development evoked by phorbol 12, 13 dibutyrate (PDBu) in cerebral and femoral arteries isolated from the dogs. In basilar artery, HNS-32 inhibited almost completely PDBu-induced contraction in a concentration-dependent manner with potency about 10 times stronger than that of fasudil, a protein kinase inhibitor. In contrast, in femoral artery, HNS-32 failed to suppress the tension development in response to PDBu whereas fasudil inhibited it with a similar potency as in basilar artery. These findings indicate that HNS-32 selectively suppresses cerebral artery contraction mediated via an activation of protein kinase C.

Mitochondrial coupling factor 6 is present on the surface of human vascular endothelial cells and is released by shear stress

BACKGROUND

We showed that mitochondrial coupling factor 6 (CF6), an endogenous inhibitor of prostacyclin synthesis, is present in the systemic circulation as a pressor substance in rats. We investigated the possibility of vascular endothelial cells as a source of circulating CF6.

METHODS AND RESULTS

We used 2 cultured endothelial cell lines, human umbilical vein endothelial cells (HUVECs) and ECV 304 cells (transformed HUVECs), for this study. Immunofluorescence microscopy of both ECV 304 and HUVECs confirmed the surface-associated immunoreactivity of anti-CF6 antibody on the plasma membrane. The concentration of CF6 in the medium increased gradually with time in both ECV 304 and HUVECs in static conditions. Exposure of ECV 304 and HUVECs to a fluid shear stress enhanced the release of CF6: In ECV 304, the concentration of CF6 in the medium (ng. well(-1). 6 hours(-1)) was 2.1+/-0.8 at baseline, 4.3+/-0.8 after shear at 15 dynes/cm(2), and 57.7+/-8.4 after shear at 25 dynes/cm(2). CF6 contents in the cell homogenate and mitochondria were both significantly increased after exposure of ECV 304 to 6-hour shear at 15 dynes/cm(2), whereas they were unchanged after shear stress at 25 dynes/cm(2). The ratio of CF6 to GAPDH mRNA was enhanced significantly, by 1.8+/-0.2-fold, after 6-hour shear stress at 25 dynes/cm(2). Flow cytometry analysis revealed that the surface-associated CF6 was significantly increased in a 3-hour static condition after the previous exposure of the cells to shear stress for 3 hours.

CONCLUSIONS

Vascular endothelial cells are a source of CF6, and shear stress regulates the release of the surface-associated CF6.

The relation between plasma homocysteine concentration and methylenetetrahydrofolate reductase gene polymorphism in pregnant women

OBJECTIVE

Our purpose was to clarify the influence of methylenetetrahydrofolate reductase (MTHFR) gene polymorphism on plasma homocysteine (Hcy) concentrations during early pregnancy.

METHODS

Between 1996 and 1998, Hcy concentration and MTHFR gene polymorphism were studied in 840 pregnant women between 6 to 12 weeks' gestation. Hcy concentration was measured by amino acid autoanalyzer (DLC-300, Nihon Denshi), and MTHFR genotypes were determined by the PCR/RFLP methods. Pregnancy outcomes were compared in association with Hcy concentration and MTHFR genotypes.

RESULTS

A total of 816 of the 840 women were enrolled into the study because MTHFR genotypes were not available in 24 women. Genotypes of C677T in the MTHFR gene were CC: CT: TT (%) = 280 (34.3): 400 (49.0): 136 (16.7). Plasma Hcy concentration was significantly (p < 0.0001) higher in women with TT genotype than other genotypes [CC: CT: TT = 5.67 (2.8-10.6): 5.80 (2.5-20.1): 6.91 (3.5-20.9) nmol/ml, median (range)]. Women with hyperhomocysteinemia had severe preeclampsia (2 of 35 vs 5 of 714, p < 0.01) and stillbirth (2 of 35 vs 10 of 714, p < 0.05) more frequently than normohomocysteinemia.

CONCLUSIONS

Plasma Hcy concentration during early pregnancy was higher in women with homozygote for the T677 allele in the MTHFR gene than other genotypes.

Tributyltin or triphenyltin inhibits aromatase activity in the human granulosa-like tumor cell line KGN

The superimposition of male sex organs (penis and vas deferens) in a female gastropod, called imposex, is widely attributed to the exposure to tributyltin (TBT) compounds, used world-wide in antifouling paints for ships. It has been hypothesized that the TBT-induced imposex is mediated by an increasing androgen level relative to the estrogen level, namely a decreased conversion of androgens to estrogens (i.e., aromatization). In the present study, we tested this hypothesis by examining the effects of TBT or triphenyltin (TPT) on the aromatase activity in a cultured human granulosa-like tumor cell line, KGN, which was recently established by our group. Treatment with more than 1000 ng/ml TBT compounds was very toxic to the cells and caused immediate cell death within 24 h, while 200 ng/ml was found to cause apoptosis of the cells. Treatment of the KGN cells for more than 48 h with 20 ng/ml TBT or TPT, which is a concentration level reported to cause imposex in marine species, did not affect cell proliferation but significantly suppressed the aromatase activity determined by a [(3)H]H(2)O release assay. Treatment with 20 ng/ml TBT compounds for 7 days also resulted in a reduction of the E2 production from Delta 4-androstenedione stimulated by db-cAMP. The changes in the aromatase activity by TBT compounds were associated with comparable changes in P450arom mRNA assessed by RT-PCR. The luciferase activity of the P450arom promoter II (1 kb) decreased after the addition of 20 ng/ml TBT compounds in transfected KGN cells either in a basic state or in states stimulated by db-cAMP. The Ad4BP-dependent increase in the luciferase activity of P450arom promoter II was also downregulated by such treatments. These results indicate that TBT compounds inhibited the aromatase activity and also decreased the P450arom mRNA level at the transcriptional level in KGN cells. The direct inhibitory effect of TBT compounds on the aromatase activity may therefore partly explain the induction of imposex by these compounds in female species.

Mammalian TOR: a homeostatic ATP sensor

The bacterial macrolide rapamycin is an efficacious anticancer agent against solid tumors. In a hypoxic environment, the increase in mass of solid tumors is dependent on the recruitment of mitogens and nutrients. When nutrient concentrations change, particularly those of essential amino acids, the mammalian Target of Rapamycin (mTOR) functions in regulatory pathways that control ribosome biogenesis and cell growth. In bacteria, ribosome biogenesis is independently regulated by amino acids and adenosine triphosphate (ATP). Here we demonstrate that the mTOR pathway is influenced by the intracellular concentration of ATP, independent of the abundance of amino acids, and that mTOR itself is an ATP sensor.

[An unconscious patients with ascending aortic aneurysm accompanied by aortic regurgitation successfully treated by emergency operation after cardiopulmonary resuscitation]

A-37-year-old woman in shock condition was transferred to our hospital after cardiopulmonary resuscitation for ventricular fibrillation. She was unconscious and suspected of suffering ischemic brain damage, with pathologic reflexes and weak brain stem reflexes. Brain CT scan showed cerebral edema without hemorrhage or infarction and an electroencephalograph revealed slow alpha-theta waves. Chest CT scan and echocardiogram showed ascending aortic aneurysm with sever aortic regurgitation. An emergent operation was performed for progression of heart failure. There were no distortion or dilatation of the sinus of Valsalva and annuloaortic ectasia and aortic valve leaflets were almost normal. We considered that the aortic valve dysfunction was cause by dilatation of the sinotubular junction. Ascending aortic and aortic valve replacement were carried out to shorten cardiopulmonary bypass time and to prevent the progression of brain damage. Mild hypothermia was employed as a neuroprotective procedure for three days after surgery. The patient's neurological symptoms, which were right hemiparesis, facial apraxia and motor aphasia, improved and she was discharged from the hospital on foot without any neurological complications on the 47th postoperative day and returned to work after two months.

Helicobacter pylori infection and coronary heart disease in Japanese patients

Although several independent studies have claimed a link between Helicobacter pylori infection and coronary heart disease (CHD), this association has not been established conclusively. The aim was to determine whether an association between H. pylori infection and CHD can be demonstrated in Japanese patients. Three-hundred and four patients who underwent consecutive coronary arteriography were investigated. Ninety-four patients had single-vessel coronary stenosis and 112 had multi-vessel stenosis. The remaining 98 patients had no significant stenosis in any coronary arteries. H. pylori infection was diagnosed serologically and the association between infection and CHD was estimated by the odds ratio. The serum pepsinogen (PG) I-II ratio was used to estimate the degree of gastric atrophy. Seropositivity for H. pylori was significantly higher in the patients with CHD (67%) than in the controls (50%; p = 0.006). The odds ratio for CHD after having H. pylori infection was estimated as 1.35 (95% confidence interval 1.03-1.78; p = 0.028), after adjustment for the common risk factors of CHD in a logistic regression analysis. The association between CHD and H. pylori infection was more significant among patients without any history of diabetes or smoking. The PG I-II ratio in H. pylori-positive patients was significantly higher in the multi-vessel group (3.46) than in the control or single-vessel group (2.86, p = 0.030; 2.78, p = 0.008; respectively). H. pylori infection was shown to be an independent risk factor for CHD in Japanese patients, especially among those who did not have a history of diabetes or smoking. These data imply that the association between H. pylori infection and CHD is clinically relevant.

Disparate effects of interleukin 11 and thrombopoietin on megakaryocytopoiesis in vitro

The effects of interleukin-11 (IL-11) and thrombopoietin (TPO) on murine megakaryocytopoiesis were studied using a serum-free culture system. Acting alone, both IL-11 and TPO increased the number of acetylcholinesterase (AchE)(+)cells (megakaryocytes), the latter being more potent than the former. TPO, but not IL-11, increased the mean AchE activity per megakaryocyte (AchE activity/megakaryocyte). TPO increased both the number of megakaryocytes with high ploidy, and of those with low ploidy. In contrast, IL-11 increased only the number of megakaryocytes with high ploidy. The effect of TPO on megakaryocyte ploidy was stronger than that of IL-11. Both IL-11 and TPO increased the proportion of large megakaryocytes, but the latter was more potent than the former. While the stimulatory effects of IL-11 and TPO on the number of megakaryocytes were enhanced by IL-3 or stem cell factor (SCF), synergism of IL-11 or TPO with IL-3 or SCF in stimulating AchE activity/megakaryocyte was inconsistent. IL-11 and TPO stimulated the formation of colony-forming units of megakaryocyte in the presence of IL-3, but not alone, with similar maximum colony numbers for both cytokines. Our findings thus demonstrate that IL-11 principally stimulates megakaryocyte maturation rather than the proliferation of megakaryocytes, whereas TPO stimulates both.

Interleukin-11 induces osteoblast differentiation and acts synergistically with bone morphogenetic protein-2 in C3H10T1/2 cells

Interleukin-11 (IL-11) is a pleiotropic cytokine that supports various types of hematopoietic cell growth and is involved in bone resorption. We report here the involvement of recombinant human IL-11 (rHuIL-11) in osteoblast differentiation in mouse mesenchymal progenitor cells, C3H10T1/2. rHuIL-11 alone increased alkaline phosphatase (ALP) activity and upregulated expression levels of osteocalcin (OC), bone sialo protein (BSP), and parathyroid hormone receptor (PTHR) mRNA. rHuIL-11 had no effect on expression of type II collagen, peroxisome proliferator-activated receptor-gamma2 (PPAR-gamma2), adipocyte fatty acid-binding protein P2 (aP2), and myogenic MyoD protein (MyoD). Recombinant human bone morphogenetic protein (rHuBMP)-2 increased ALP activity and mRNA expression of these genes except for MyoD. The expression patterns of ALP activity and osteoblast-specific or chondrocyte-specific genes suggest that rHuIL-11 may be involved in early differentiation of osteoblasts at a step earlier than that which is affected by rHuBMP-2. In support of this hypothesis, combined treatment with rHuIL-11 and rHuBMP-2 synergistically increased ALP activity and mRNA expression of OC and type II collagen, rHuIL-11 also abrogated the increased levels of PPAR-gamma2, aP2 mRNA caused by rHuBMP-2. Our results suggest that rHuIL-11 alone and in combination with rHuBMP-2 can induce osteoblastic differentiation of progenitor cells and plays an important role in osteogenesis.

[Significance of nucleic acid extraction for the performance of COBAS AMPLICOR Mycobacterium-PCR assay]

On an AMPLICOR-PCR assay for the diagnosis of mycobacterial infections, it has been found that approximately 10% of the routinely performed assays appear as indefinable cases with internal control (IC)-negative, which is caused by contaminant PCR-inhibitory substances in the extracted nucleic sample. To decrease the number of indefinable cases, we studied the IC performance of four nucleic acid extraction methods in one manual method(A) and three commercial kits(B, C and D). Thirty samples from 10 kinds of specimens without mycobacterial infections were subjected to the four nucleic extraction methods and the nucleic extracts were compared on PCR-inhibitory. The frequency of IC-negative samples was different among the four methods and the rates were 33.3%(n = 10) in A, 30.0%(n = 9) in B, 16.7%(n = 5) in C and 6.7%(n = 2) in D. In the PCR-inhibitory experiments using serially diluted IC-negative samples, the recovery of IC positivity was also different according to the method used. Although the IC-negative nucleic samples by D method easily became IC-positive at the 1/5 range of dilution, some of the IC-negative nucleic samples by A, B or C method were still IC-negative in the 1/10 range. These results indicate that the occurrence rate of indefinable cases with IC-negative is markedly different in the nucleic extraction method, suggesting that utilizing a suitable nucleic acid extraction method is important when using the diagnostic AMPLICOR-PCR assay.

Lymphatics of the rat mammary gland during virgin, pregnant, lactating and post-weaning periods

The distribution and ultrastructure of the lymphatics of the rat mammary gland in virgin, pregnant, lactating and post-weaning periods were examined by enzyme-histochemistry for 5'-nucleotidase (5'-Nase) and transmission electron microscopy. Enzyme-histochemistry for 5'-Nase stained lymphatics in dark brown. In the lactating period, lymphatics abounded in the interlobular connective tissues, but in other periods they were few. The interlobular lymphatics drained into collecting lymphatics running along the mammary ducts. Gaps between lymphatic endothelial cells were significantly wider in lactating period than in other periods, while both number and area of vesicles in the lymphatic endothelial cells were significantly larger in the virgin period than in other periods. In the pregnant and lactating period, the lymphatics contained many lymphocytes and lipid droplets. The results show that during lactating period, the interlobular lymphatics increase and that gaps between lymphatic endothelial cells serve as a major route through which tissue fluids and particulate matters enter the lymphatics, while vesicles seem to be main trans-endothelial transport route during the virgin period. The results will provide basic information for our next investigation on lymphangiogenesis in association with breast cancer.

Direct Cardiac Potential Trigger for Chronic Control of a Ventricular Assist Device

As a new trigger method for chronic drive control of a ventricular assist device (VAD), a direct cardiac potential trigger was assessed under various conditions in a chronic experimental model. A pneumatic pulsatile VAD was implanted as circulatory support between the left ventricular apex and the ascending aorta in 12 adult pigs. Hemodynamic parameters and pump output were continuously monitored. Two tips of a bipolar electrode were set on the RV anterior wall and the LV posterior wall for recording direct cardiac potential. Counterpulsation drive of the VAD was applied by using the R wave in a standard electrocardiogram (ECG) or the direct cardiac potential as an ECG trigger. As special conditions, various artifacts on ECG, electromusculogram, arrhythmia, irregular ventilation, and passive vibration (simulation of exercise) were set for assessing the ECG trigger modes. Artifacts of irregular ventilation and passive vibration made the drive control poor using a standard ECG trigger. In contrast, the direct cardiac potential trigger maintained the counterpulsation control of the VAD well in all conditions of this study, and was a safe and reliable support for the native heart. It also supported animals for up to 48 hours after operation. The above results suggested that the direct cardiac potential trigger might be useful for monitoring native heart beats and adjusting the support cycle to the native heart cycle as a chronic control method for various VADs.

Surface fluctuations of normal and superfluid 3He probed by Wigner solid dynamics

Electron scattering from surface fluctuations on normal and superfluid 3He has been measured by its effect on the linewidth of the low-wave-vector transverse magnetophonon mode of the electron crystal (the Wigner solid) floating on the helium surface. The relaxation rate becomes anomalously low below 70 mK, and reaches a plateau at about 3 times less than its expected value before dropping further at the superfluid transition. The absence of such anomalous behavior on 4He suggests that the effect is specific to liquid 3He.

[Identification of Vibrio vulnificus from patients with otitis media and septicemia by PCR method]

Sucrose-negative colonies were isolated on TCBS agar plate from otorrhea specimens from otitis media patient in the Adult Diseases Examination Center, Hirosaki Medical Association. The isolate was identified as Vibrio vulnificus by nested PCR method which amplify V. vulnificus-specific sequences directed against 23S rRNA genes. The PCR method was applied to identify 6 strains originally isolated from septicemia patients in Kurashiki Central Hospital and formerly identified as V. vulnificus by phenotypic characteristics. When examined by the API20E system, the above PCR confirmed-V. vulnificus isolates were correctly identified as V. vulnificus with % ID 99.8, though this gave 3 different profiles. Cytotoxin-hemolysin gene was detected in otorrhea strain as well as septicemia strains by PCR method. The above results suggest that PCR method targeted cytotoxin-hemolysin gene is suitable for rapid and accurate identification of the isolate, because the result is obtained in less than 4 h. To our knowledge this is the first report on the V. vulnificus infection in Aomori Prefecture and the isolation from otorrhea.

Rap1 is involved in cell stretching modulation of p38 but not ERK or JNK MAP kinase

Mechanical force or mechanical stress modulates intracellular signal pathways, including the mitogen-activated protein kinase (MAP kinase) cascades. In our system, cell stretching activated and cell contraction inactivated all three MAP kinase pathways (MKK1/2-extracellular signal-regulated kinase (ERK), MKK4 (SEK1)-cJun N-terminal kinase (JNK) and MKK3/6-p38 pathways). However, little is known about the molecular mechanisms that link the mechanical force to the MAP kinase cascades. To test whether Ras and Rap1 are possible components in the stretch-activated MAP kinase pathways, we examined if Ras and Rap1 were activated by cell stretching and if inhibition of their activity decreased the stretch-enhanced MAP kinase activity. Rap1 was activated by cell stretching and inactivated by cell contraction, whereas Ras was inactivated by cell stretching and activated by cell contraction. Rap1GapII and SPA-1, downregulators of Rap1 activity, decreased the stretch-enhanced p38 activity, whereas a dominant-negative mutant of Ras (RasN17) did not inhibit the stretch-initiated activation of MAP kinases. Furthermore, overexpression of Rap1 enhanced p38 activity but not ERK or JNK activity. These results indicate that Rap1 is involved in transducing the stretch-initiated signal to the MKK3/6-p38 pathway, but not to the MEK1/2-ERK or the MKK4 (SEK1)/MKK7-JNK pathway. Thus, Rap1 plays a unique role in force-initiated signal transduction.

Kinetic analysis of megakaryopoiesis induced by recombinant human interleukin 11 in myelosuppressed mice

Recombinant human interleukin 11 (rhIL-11) has previously been shown to ameliorate thrombocytopenia in several animal models. To elucidate the mechanisms involved in rhIL-11-induced hematopoiesis, a kinetic analysis of megakaryopoiesis was performed in mitomycin C (MMC)-induced myelosuppressive mice. Mice intravenously injected with MMC (2 mg/kg) for two consecutive days from day -1 developed severe thrombocytopenia with a nadir of platelet counts at 24x10(4)/microl on day 12 and neutropenia. Treatment with rhIL-11 (500 microg/kg/day) from day 1 to 21 significantly ameliorated the degree and duration of thrombocytopenia and enhanced the platelet recovery, and also enhanced the recovery from neutropenia. In MMC-treated mice, the decreases in bone marrow megakaryocyte progenitors and megakaryocyte counts preceded the decrease in platelet counts by MMC treatment. RhIL-11 induced an increase in the number of megakaryocyte progenitors from day 4 to 14, followed by an increase in the megakaryocytes by day 20. There was a ploidy shift in megakaryocytes towards lower ploidy cells by day 9 in myelosuppressed mice. RhIL-11 caused a shift towards a higher ploidy with 32 and 64N on day 4, and 32N on day 14. These results suggest that rhIL-11 ameliorates the thrombocytopenia via the stimulation of both the maturation and commitment followed by the proliferation of megakaryocytic cells.

[A case report of hemiparesis due to compression of the medulla oblongata by an elongated vertebral artery]

The authors report a case of a 53-year-old woman who developed symptoms and signs of compression of the left medulla oblongata by the elongated and curved left vertebral artery with normal diameter. Twelve days before admission to the hospital, the patient suddenly noticed severe occipital-nuchal headache and nausea with vomiting, while she was unloading a burden. Neurological examination revealed left facial hyperalgesia, right hemihypesthesia and mild right hemiparesis. Hoarseness was observed, but the movement of the uvula and tongue was normal. Hypertension was noticed (180/100). Cerebral and vertebral angiography revealed no aneurysm, but demonstrated an elongated and curved V4 portion of the left vertebral artery with normal diameter. Coronal plain of T2 weighted image of MRI and CT scan with metrizamide administered into the CSF, clearly demonstrated an elongated and curved left vertebral artery compressing the ventro-lateral portion of the left medulla oblongata, neurovascular decompression of the V4 from the medulla oblongata was performed. Through the operating microscope, it was observed that the elongated and curved V4 portion of the left vertebral artery with normal configuration was compressing the left medulla oblongata ventro-laterally, making a compression notch at the outlets of the cranial nerves IX and X. Transposition of the V4 portion was impossible. Some pieces of Taflon felt, thick enough to prevent the pulsatile movement of the V4 from compressing the medulla oblongata, were inserted between the V4 and the medulla oblongata. Two months after the operation, the patient's right hemiparesis and sensory disturbances were gradually improving and her blood pressure had become normal. The authors emphasize that, among patients with symptoms and signs of compression of the medulla oblongata, there is at least one patient for whom neurovascular decompression was an effective treatment.

HNS-32, a novel azulene-1-carboxamidine derivative, inhibits nifedipine-sensitive and -insensitive contraction of the isolated rabbit aorta

The vasorelaxant profile of a novel azulene-1-carboxamidine derivative, HNS-32 [N1,N1-dimethyl-N2-(2-pyridylmethyl)-5-isopropyl-3,8-dimethyl-azulene-1-carboxamidine, CAS 186086-10-2], was investigated in the isolated rabbit aorta precontracted with high KCl, noradrenaline (NA) or phorbol 12, 13-dibutyrate (PDBu) and compared with those of nifedipine and nitroglycerin. In preparations without endothelium, HNS-32 elicited concentration-dependent, full inhibition of contractions elicited by high KCI (80 mM), NA (3x10(-6) M) or PDBu (10(-6) M). In contrast, nifedipine inhibited only the contraction elicited by membrane depolarization with high KCl. Nitroglycerin also attenuated high-KCl-, NA- and PDBu-elicited contractions effectively, although full suppression was obtained only for NA-elicited contraction. Whilst the relaxant effect of HNS-32 was not affected by the presence of endothelium, the relaxant response to acetylcholine was endothelium dependent. Addition of excess Ca2+ restored both the HNS-32-reduced tension in muscle precontracted with high KCI and the nifedipine-mediated tension decrease. Relaxation elicited by HNS-32 was not affected by the adenylate cyclase inhibitor, 9-(tetrahydro-2'-furyl)adenine (SQ 22,536, 10(-4) M), the soluble guanylate cyclase inhibitor, 1H-(1,2,4)-oxadiazolo-(4,3-a)-quinoxalin-1-one (ODQ, 10(-5) M) or a cocktail of K+ channel blockers (glybenclamide 10(-6) M, tetraethylammonium 2x10(-3) M, apamin 10(-7) M, 4-aminopyridine 10(-4) M and Ba2+ 10(-5) M). These findings indicate that HNS-32 inhibits both L-type Ca2+ channel-dependent and -independent vascular contraction. Blockade of Ca2+ entry through L-type Ca2+ channels may be involved in the inhibitory effect of HNS-32 on the contraction due to membrane depolarization with high KCl. On the other hand, HNS-32 seems to inhibit Ca2+ channel-independent contraction via mechanism(s) other than elevation of cyclic nucleotides (cAMP and cGMP) and opening of K+ channels.