Magnesium causes nitric oxide independent coronary artery vasodilation in humans

OBJECTIVE

To determine how magnesium affects human coronary arteries and whether endothelium derived nitric oxide (EDNO) is involved in the coronary arterial response to magnesium.

DESIGN

Quantitative coronary angiography and Doppler flow velocity measurements were used to determine the effects of the nitric oxide synthase inhibitorNG-monomethyl-L-arginine (L-NMMA) on magnesium induced dilation of the epicardial and resistance coronary arteries.

SETTING

Hiroshima University Hospital a tertiary cardiology centre.

PATIENTS

17 patients with angiographically normal coronary arteries.

INTERVENTIONS

Magnesium sulfate (MgSO4) (0.02 mmol/min and 0.2 mmol/min) was infused for two minutes into the left coronary ostium before and after intracoronary infusion of L-NMMA.

MAIN OUTCOME MEASURES

Diameter of the proximal and distal segments of the epicardial coronary arteries and coronary blood flow.

RESULTS

At a dose of 0.02 mmol/min, MgSO4 did not affect the coronary arteries. At a dose of 0.2 mmol/min, MgSO4 caused coronary artery dilation (mean (SEM) proximal diameter 3.00 (0.09) to 3.11 (0.09) mm; distal 1.64 (0.06) to 1.77 (0.07) mm) and increased coronary blood flow (79.3 (7.5) to 101.4 (9.9) ml/min, p < 0.001 vbaseline for all). MgSO4 increased the changes in these parameters after the infusion of L-NMMA (p < 0.001v baseline).

CONCLUSIONS

Magnesium dilates both the epicardial and resistance coronary arteries in humans. Furthermore, the coronary arterial response to magnesium is dose dependent and independent of EDNO.

Modulation of alpha-ENaC and alpha1-Na+-K+-ATPase by cAMP and dexamethasone in alveolar epithelial cells

cAMP and dexamethasone are known to modulate Na+ transport in epithelial cells. We investigated whether dibutyryl cAMP (DBcAMP) and dexamethasone modulate the mRNA expression of two key elements of the Na+ transport system in isolated rat alveolar epithelial cells: alpha-, beta-, and gamma-subunits of the epithelial Na+ channel (ENaC) and the alpha1- and beta1-subunits of Na+-K+-ATPase. The cells were treated for up to 48 h with DBcAMP or dexamethasone to assess their long-term impact on the steady-state level of ENaC and Na+-K+-ATPase mRNA. DBcAMP induced a twofold transient increase of alpha-ENaC and alpha1-Na+-K+-ATPase mRNA that peaked after 8 h of treatment. It also upregulated beta- and gamma-ENaC mRNA but not beta1-Na+-K+-ATPase mRNA. Dexamethasone augmented alpha-ENaC mRNA expression 4.4-fold in cells treated for 24 h and also upregulated beta- and gamma-ENaC mRNA. There was a 1.6-fold increase at 8 h of beta1-Na+-K+-ATPase mRNA but no significant modulation of alpha1-Na+-K+-ATPase mRNA expression. Because DBcAMP and dexamethasone did not increase the stability of alpha-ENaC mRNA, we cloned 3.2 kb of the 5' sequences flanking the mouse alpha-ENaC gene to study the impact of DBcAMP and dexamethasone on alpha-ENaC promoter activity. The promoter was able to drive basal expression of the chloramphenicol acetyltransferase (CAT) reporter gene in A549 cells. Dexamethasone increased the activity of the promoter by a factor of 5.9. To complete the study, the physiological effects of DBcAMP and dexamethasone were investigated by measuring transepithelial current in treated and control cells. DBcAMP and dexamethasone modulated transepithelial current with a time course reminiscent of the profile observed for alpha-ENaC mRNA expression. DBcAMP had a greater impact on transepithelial current (2.5-fold increase at 8 h) than dexamethasone (1.8-fold increase at 24 h). These results suggest that modulation of alpha-ENaC and Na+-K+-ATPase gene expression is one of the mechanisms that regulates Na+ transport in alveolar epithelial cells.

Virological properties and nucleotide sequences of Cas-E-type endogenous ecotropic murine leukemia viruses in South Asian wild mice, Mus musculus castaneus

Two types of endogenous ecotropic murine leukemia viruses (MuLVs), termed AKV- and Cas-E-type MuLVs, differ in nucleotide sequence and distribution in wild mouse subspecies. In contrast to AKV-type MuLV, Cas-E-type MuLV is not carried by common laboratory mice. Wild mice of Mus musculus (M. m.) castaneus carry multiple copies of Cas-E-type endogenous MuLV, including the Fv-4(r) gene that is a truncated form of integrated MuLV and functions as a host's resistance gene against ecotropic MuLV infection. Our genetic cross experiments showed that only the Fv-4(r) gene was associated with resistance to ecotropic F-MuLV infection. Because the spontaneous expression of infectious virus was not detected in M. m. castaneus, we generated mice that did not carry the Fv-4(r) gene but did carry a single or a few endogenous MuLV loci. In mice not carrying the Fv-4(r) gene, infectious MuLVs were isolated in association with three of six Cas-E-type endogenous MuLV loci. The isolated viruses showed a weak syncytium-forming activity for XC cells, an interfering property of ecotropic MuLV, and a slight antigenic variation. Two genomic DNAs containing endogenous Cas-E-type MuLV were cloned and partially sequenced. All of the Cas-E-type endogenous MuLVs were closely related, hybrid-type viruses with an ecotropic env gene and a xenotropic long terminal repeat. Duplications and a deletion were found in a restricted region of the hypervariable proline-rich region of Env glycoprotein.

Chromosomal mapping of 18S-28S rRNA genes and 10 cDNA clones of human chromosome 1 in the musk shrew (Suncus murinus)

The direct R-banding fluorescence in situ hybridization (FISH) method was used to map 18S-28S ribosomal RNA genes and 10 human cDNA clones on the chromosomes of the musk shrew (Suncus murinus). The chromosomal locations of 18S-28S ribosomal RNA genes were examined in the five laboratory lines and wild animals captured in the Philippines and Vietnam, and the genes were found on chromosomes 5, 6, 9, and 13 with geographic variation. The comparative mapping of 10 cDNA clones of human chromosome 1 demonstrated that human chromosome 1 consisted of at least three segments homologous to Suncus chromosomes (chromosomes 7, 10, and 14). This approach with the direct R-banding FISH method is useful for constructing comparative maps between human and insectivore species and for explicating the process of chromosomal rearrangements during the evolution of mammals.

Coronary atherosclerosis and oxidative stress as reflected by autoantibodies against oxidized low-density lipoprotein and oxysterols

Clinical studies and animal experiments have demonstrated that oxidized low-density lipoprotein (oxLDL) and oxysterols play important roles in atherogenesis. OxLDL is immunogenic, and autoantibodies (Ab) against oxLDL are detectable in serum. We investigated the relevance of oxysterols and Ab against-oxLDL to coronary artery disease (CAD) in 183 patients undergoing coronary angiography. Patient groups included angiographically normal subjects (< 75% stenosis), others with spasm (> 75% narrowing in response to acetylcholine), and some others with fixed stenosis (> 75%). The group with stenosis was subdivided into patients with stable and unstable angina. Serum concentrations of autoantibodies and 25-, 27-, and 7-beta-hydroxycholesterols were significantly higher in the stenotic group than in the normal group (P < 0.01, P < 0.05, P < 0.05, and P < 0.05, respectively). Antibodies, but not oxysterol concentrations, were significantly greater in subjects with unstable than with stable angina (P < 0.01). We conclude that anti-oxLDL antibody and oxysterol concentrations are associated with coronary artery stenosis, and that oxidative stress may be greatly increased in unstable angina.

A Robertsonian translocation, rob(2;28), found in Vietnamese cattle

A new Robertsonian translocation, rob(2;28), was discovered in a local population of the Vietnamese Cattle. The animal (2n = 59, XY) was found by Q- and R-banding to be a heterozygous carrier of a centric fusion translocation involving chromosomes 2 and 28. FISH analysis using a bovine satellite I DNA probe demonstrated that the centromeric heterochromatin block of the rob(2;28) chromosome become much smaller than its ancestors suggesting a monocentric nature of this centric fusion. This is the first report identifying a Robertsonian translocation in Southeast Asian cattle by karyotyping of banded chromosomes.

Nonredundant roles of the elongation factor MEN in postimplantation development

The MEN/ELL gene was cloned as a fusion partner of the MLL gene in the t(11;19)(q23;p13.1) translocation, which is found in adult myeloid leukemia. MEN belongs to a family of RNA polymerase II elongation factors and dysregulated production of MEN through the MLL promoter could cause malignant transformation of myeloid cells. To pursue the physiological role and determine the requirement of the MEN gene product in mouse development, we generated knockout mice (MEN-/-) by gene targeting in embryonic stem cells. After intercrossing heterozygous mice to generate homozygous mutants, we identified no homozygotes (MEN-/-) even at E9.5, as well as after birth, by Southern analysis. Moreover, histological examinations revealed degenerative changes in nearly one-fourth of E6.5 embryos, which were gradually resorbed by E8.5. Our findings demonstrated that MEN-/- mice are embryonic lethal, and die before E6.5 and after implantation. MEN should play a nonredundant role in postimplantation development of mice.

Azido glycoside primer: a versatile building block for the biocombinatorial synthesis of glycosphingolipid analogues

A lactoside primer, 12-azidododecyl beta-lactoside, was synthesized via the Koenigs-Knorr method by glycosylation of 1,12-dodecyldiol with perbenzoylated lactosyl bromide. The presence of the 2-O-acyl substituent in the donor gave the beta-lactoside, and an excess of acceptor ensured monoglycosylation of the diol. Mesylation of the omega-hydroxyl group in the aglycon, followed by displacement of the mesylate with azide and subsequent O-debenzoylation gave the desired omega-azidododecyl beta-lactoside. The azido glycoside primer was examined in mouse B16 melanoma cells for its feasibility as a building block for oligosaccharide biosynthesis. Uptake of the azido glycoside primer by B16 cells resulted in the sialylation of the galactose residue of the primer to give a glycosylated product having the same glycan as in ganglioside GM3. After 24 h incubation of B16 cells with the primers, the amount of sialylated omega-azidododecyl beta-lactoside primer was 75% of the amount of sialylated n-dodecyl beta-lactoside. However, after 48 h incubation, both primers gave equal amounts of the sialylated products. Interestingly, the remaining azido glycoside primer after 48 h incubation was 5.6-fold greater than that of the alkyl primer, indicating degradation of the alkyl primer to a larger extent than the omega-azido glycoside primer. The facile chemical synthesis and the efficient uptake in cells make the azido glycoside primer a versatile building block for the biocombinatorial synthesis of glycolipid oligosaccharides.

The preventive effect of magnesium on coronary spasm in patients with vasospastic angina

STUDY OBJECTIVES

Previous studies have reported that magnesium (Mg) deficiency is associated with coronary spasm. However, little is known about the preventive effect of Mg on coronary spasm. The present study investigated whether Mg prevents coronary spasm in patients with vasospastic angina (VSA).

DESIGN

Effectiveness trial.

SETTING

University medical center.

PATIENTS

Twenty-two patients with VSA.

INTERVENTION

Coronary spasm was induced with an intracoronary infusion of acetylcholine (Ach). After spontaneous relief of the coronary spasm, Mg sulfate (0.27 mmol/kg body weight) was infused IV over 20 min in 14 patients and isotonic glucose was infused in 8 patients as control subjects. Intracoronary infusion of Ach was then repeated, and the diameter of the coronary arteries was measured quantitatively.

MEASUREMENTS AND RESULTS

Mg infusion caused coronary artery dilatation at baseline in both the spastic (5. 9 +/- 2.3%) and nonspastic segments (5.5 +/- 1.5%). Mg infusion reduced the severity of chest pain and ST-segment deviations during coronary spasm. After the Mg infusion, the percent change in the diameter of the spastic segments improved from - 62.8 +/- 2.6% to - 43.7 +/- 4.7% during coronary spasm. Overall, 10 of 14 patients (71%) responded favorably to Mg infusion. Isotonic glucose infusion did not elicit changes in chest pain severity, ST-segment deviations, or the diameter of the coronary arteries during spasm.

CONCLUSIONS

Mg infusion produces nonsite-specific basal coronary dilatation and suppresses Ach-induced coronary spasm in patients with VSA.

Double ventricular response by a single ventricular extrastimulus to the inner loop of reentry in a patient without apparent heart disease

In a patient without apparent heart disease, a ventricular extrastimulus delivered from the left ventricular apex where the electrogram was recorded 30 ms after the onset of the QRS complex during VT advanced the second QRS complex, but not the first QRS complex. The morphology of the second QRS complex was the same as that of VT. The postpacing interval was the same as the cycle length of the VT. These findings indicated that the site of stimulation was at the inner loop of the reentry circuit of the VT. A ventricular extrastimulus with a shorter coupling interval advanced the first and second QRS complexes, indicating that the ventricle was activated by antidromic and orthodromic activation from the extrastimulus. Radiofrequency ablation at that site of stimulation terminated the VT and no further VT could be induced.

[A case of pulmonary cavernous hemangioma: immunohistological examination revealed its endothelial cell origin]

A 29-year-old woman was referred to our hospital for an abnormal shadow on chest roentgenogram. She had no symptom but its shadow was pointed out about 20 years ago. Chest CT scan showed a sharply demarcated homogenous mass measured 10 x 10 mm in the S4 segment. The tumor was resected with video-assisted thoracoscopic surgery under CT-guided marking wire inserted. Microscopic examination suspected cavernous hemangioma. Immunohistological staining demonstrated most lining cells of the cavernous structure stained positively for von Willebrand factor antibody, which suggests that this tumor was associated with endothelium. Then we decided that this tumor was pulmonary cavernous hemangioma.

Large expansion of the ATTCT pentanucleotide repeat in spinocerebellar ataxia type 10

Spinocerebellar ataxia type 10 (SCA10; MIM 603516; refs 1,2) is an autosomal dominant disorder characterized by cerebellar ataxia and seizures. The gene SCA10 maps to a 3.8-cM interval on human chromosome 22q13-qter (refs 1,2). Because several other SCA subtypes show trinucleotide repeat expansions, we examined microsatellites in this region. We found an expansion of a pentanucleotide (ATTCT) repeat in intron 9 of SCA10 in all patients in five Mexican SCA10 families. There was an inverse correlation between the expansion size, up to 22.5 kb larger than the normal allele, and the age of onset (r2=0.34, P=0.018). Analysis of 562 chromosomes from unaffected individuals of various ethnic origins (including 242 chromosomes from Mexican persons) showed a range of 10 to 22 ATTCT repeats with no evidence of expansions. Our data indicate that the new SCA10 intronic ATTCT pentanucleotide repeat in SCA10 patients is unstable and represents the largest microsatellite expansion found so far in the human genome.

Acetylation of GATA-3 affects T-cell survival and homing to secondary lymphoid organs

Acetylation of a transcription factor has recently been shown to play a significant role in gene regulation. Here we show that GATA-3 is acetylated in T cells and that a mutation introduced into amino acids 305-307 (KRR-GATA3) creates local hypoacetylation in GATA-3. Remarkably, KRR-GATA3 possesses the most potent suppressive effect when compared with other mutants that are disrupted in putative acetylation targets. Expressing this mutant in peripheral T cells results in defective T-cell homing to systemic lymphnodes, and prolonged T-cell survival after activation. These findings have significant implications in that the acetylation state of GATA-3 affects its physiological function in the immune system and, more importantly, provides evidence for the novel role of GATA-3 in T-cell survival and homing to secondary lymphoid organs.

Characterization and chromosomal distribution of a novel satellite DNA sequence of Japanese quail (Coturnix coturnix japonica)

A novel satellite DNA sequence of Japanese quail (Coturnix coturnix japonica) was isolated from genomic DNA digested with restriction endonuclease, Bg/II. Sequence analysis of three different-size clones revealed the presence of a tandem array of a GC-rich 41 bp repeated element. This sequence was localized by fluorescence in situ hybridization (FISH) primarily to microchromosomes of Japanese quail (2n = 78); approximately 50 of the 66 microchromosomes showed positive signals, although hybridization signals were also detected on chromosomes 4 and W. This satellite DNA did not cross-hybridize with genomic DNA of chicken (Gallus gallus) and Chinese painted quail (Excalfactoria chinensis) under moderately stringent conditions, suggesting that this class of repetitive DNA sequences was species specific and fairly divergent in Galliformes species.

Scanning electron microscopic study of the neuromuscular junctions of the cricothyroid and thyroarytenoid muscles in rats

Neuromuscular junctions were observed in the cricothyroid (CT) and thyroarytenoid (TA) muscles of adult rats by scanning electron microscopy after removing the intramuscular connective tissue components using the HCI hydrolysis method. Morphologically, the junctions were classified into three types in the CT muscle and two types in the TA muscle, based on the structural characteristics of the subneural apparatuses, including junctional folds. In the CT muscle, type 1 junctions (32%) consisted of more than 15 cup-like depressions with slit-like junctional folds. Type 2 junctions (20%) were characterized by approximately 10 cup-like depressions with a small number of pit- or slit-like junctional folds. Type 3 junctions (48%) had irregular labyrinthine gutters with slit-like junctional folds. In the TA muscle, type 1 (82%) and 2 (18%) junctions had similar structures to type 1 and 2 junctions in the CT muscle, respectively. Histochemical studies using myosin adenosine triphosphatase staining showed that both CT and TA muscles predominantly consisted of type II muscle fibers (78% and 82%, respectively), and that the diameter of type II fibers was larger than that of type I fibers. These findings suggest that the type 2 junction belongs to type I muscle fibers, while both type 1 and type 3 junctions belong to type II fibers, and that the type 3 junction is a structural variation of the type 1 junction. The significance of the structural differences of the subneural apparatuses in the intrinsic laryngeal muscles is discussed briefly.

Hereditary persistent right oviduct in the chicken PNP/DO line

Hereditary, persistent, right oviduct manifested in an inbred line (PNP/DO line) from the Fayoumi breed of chickens was investigated for form of expression and mode of inheritance. Females in the PNP/DO line have varying lengths of elongated right oviducts, besides the normal left ovary, and oviducts that generally possess, irrespective of their total length, regions similar to those normally observed in a left oviduct. Observations of embryos indicated that the existence of right oviduct in this line could be attributed to the slow regression of right Müllerian duct during the embryonic stage, and left-right asymmetry in female genital system is intrinsic in this line. Intracrosses of the PNP/DO line produced 93% of female embryos with persistent right Müllerian ducts at the next generation, and reciprocal crosses of the PNP/DO line and control strains produced 5 and 30% of female embryos with persistent right Müllerian ducts in the F1 and N2 generations, respectively. Mating results suggested that this mutant trait is controlled by two pairs of autosomal recessive genes with major effects and numerous loci that have minor effects. Thus, expression of this trait is due to the interaction of major loci and the background genotype.

Soft dipole resonance in the neutron-skin nucleus 6He

A candidate for a soft dipole resonance, a dipole oscillation mode between a core cluster and a neutron skin, was observed at Ex = 4+/-1 MeV and with a width of 4+/-1 MeV in 6He via the 6Li( 7Li, 7Be) reaction at an incident energy of 65A MeV and forward scattering angles including 0 degrees. Its cross section is deduced to be sigma(0 degrees ) = 0.9+/-0.2 mb/sr. This value is comparable to that of the giant dipole resonance simultaneously measured.

Postnatal morphodifferentiation of the subneural apparatuses of the posterior cricoarytenoid muscle in rats: a scanning electron microscopy study

The subneural apparatus, i. e., the post-synaptic component of the neuromuscular junction, in the posterior cricoarytenoid muscle of the rat was studied by scanning electron microscopy, with special attention given to its postnatal differentiation along with the functional development of the muscle. Primitive synaptic troughs observed in the first postnatal week consisted of single cup-like depressions 5-6 microm in diameter. On the 7th day, low sarcoplasmic ridges appeared in the trough. In the second postnatal week, muscle fibers could be classified into two groups: large (10-15 microm in diameter) and small (less than 10 microm in diameter). In the large muscle fibers, many low ridges became circular and protruded to transform the single trough into numerous cup-like depressions (2-5 microm in diameter). In contrast, the subneural apparatus in the small muscle fibers consisted of a small number of cup-like depressions. The two types of subneural apparatus differentiated into adult forms by the 28th postnatal day, although they remained smaller in size than those of adults. In the large muscle fibers, the number of pit-like or elongated invaginations increased and gradually transformed into slit-like junctional folds by the 28th postnatal day, while the small muscle fibers still possessed a few pit-like or elongated junctional folds at this point in time. The two types of morphodifferentiation of the subneural apparatus are thought to reflect the two types of muscle fibers in the rat posterior cricoarytenoid muscle.

The evi-1 oncoprotein inhibits c-Jun N-terminal kinase and prevents stress-induced cell death

Evi-1 encodes a nuclear protein involved in leukemic transformation of hematopoietic cells. Evi-1 possesses two sets of zinc finger motifs separated into two domains, and its characteristics as a transcriptional regulator have been described. Here we show that Evi-1 acts as an inhibitor of c-Jun N-terminal kinase (JNK), a class of mitogen-activated protein kinases implicated in stress responses of cells. Evi-1 physically interacts with JNK, although it does not affect its phosphorylation. This interaction is required for inhibition of JNK. Evi-1 protects cells from stress-induced cell death with dependence on the ability to inhibit JNK. These results reveal a novel function of Evi-1, which provides evidence for inhibition of JNK by a nuclear oncogene product. Evi-1 blocks cell death by selectively inhibiting JNK, thereby contributing to oncogenic transformation of cells.

Possible role of hepatocyte growth factor/scatter factor and activin A produced by the target organ in liver metastasis

The molecular mechanism of organ-specific metastasis to the liver remains largely unknown. However, it is conceivable that paracrine growth factors produced by a target organ induce migration and proliferation of malignant cells to that organ, and this is the cause of organ-specific metastasis. In this study, we investigated the effect of hepatocyte growth factor/scatter factor (HGF/SF) and activin A, which are known to be produced by the liver, on the motility and growth of liver-metastatic cell line FBJ-LL. HGF/SF and activin A induced motility synergistically, but they did not affect the proliferation of FBJ-LL cells. Expression of the HGF/SF receptor, the c-met gene, and the activin-receptor type IA, type IB, and type IIA genes in FBJ-LL cells was detected by reverse transcription polymerase chain reaction. These findings suggest that both HGF/SF and activin A promote organ-specific metastasis to the liver by induction of migration through their specific receptors on liver-metastatic cells.

Genomic rearrangement in NEMO impairs NF-kappaB activation and is a cause of incontinentia pigmenti. The International Incontinentia Pigmenti (IP) Consortium

Familial incontinentia pigmenti (IP; MIM 308310) is a genodermatosis that segregates as an X-linked dominant disorder and is usually lethal prenatally in males. In affected females it causes highly variable abnormalities of the skin, hair, nails, teeth, eyes and central nervous system. The prominent skin signs occur in four classic cutaneous stages: perinatal inflammatory vesicles, verrucous patches, a distinctive pattern of hyperpigmentation and dermal scarring. Cells expressing the mutated X chromosome are eliminated selectively around the time of birth, so females with IP exhibit extremely skewed X-inactivation. The reasons for cell death in females and in utero lethality in males are unknown. The locus for IP has been linked genetically to the factor VIII gene in Xq28 (ref. 3). The gene for NEMO (NF-kappaB essential modulator)/IKKgamma (IkappaB kinase-gamma) has been mapped to a position 200 kilobases proximal to the factor VIII locus. NEMO is required for the activation of the transcription factor NF-kappaB and is therefore central to many immune, inflammatory and apoptotic pathways. Here we show that most cases of IP are due to mutations of this locus and that a new genomic rearrangement accounts for 80% of new mutations. As a consequence, NF-kappaB activation is defective in IP cells.

CIZ, a zinc finger protein that interacts with p130(cas) and activates the expression of matrix metalloproteinases

p130(cas) (Cas) is a docking protein that contains an SH3 domain and multiple tyrosine residues. p130(cas) is located at focal adhesions, is tyrosine phosphorylated in response to integrin stimulation, and is thought to transmit signals, via c-Crk and other proteins, for the remodeling of actin stress fibers and cell movement. In a search for the ligands of the SH3 domain of p130(cas) by far-Western screening, we cloned a novel protein named CIZ (for Cas-interacting zinc finger protein). CIZ consists of the following: a putative leucine zipper; a serine/threonine-rich region; a proline-rich sequence; five, six, or eight Krüppel-type C(2)H(2) zinc fingers; and the glutamine-alanine repeat. CIZ binds Cas in cells and is located in the nucleus and at focal adhesions. We showed that CIZ is a nucleocytoplasmic shuttling protein, by using the transient interspecies heterokaryon formation assay. In order to search for the targets of CIZ in nucleus, we determined the DNA binding consensus of CIZ as (G/C)AAAAA(A) by cyclic amplification and selection of targets analysis. The consensus-like sequences are found in several promoters of matrix metalloproteinases (MMPs), which are the enzymes used to degrade the extracellular matrix proteins. CIZ binds to a consensus-like sequence in the MMP-1 (collagenase) promoter. Overexpression of CIZ upregulates the transcriptions from MMP-1, MMP-3 (stromelysin), and MMP-7 (matrilysin) promoters, and this transactivation was enhanced in the presence of Cas. Furthermore, the stable overexpression of CIZ promoted the production of MMP-7 in culture medium. In summary, CIZ, a novel zinc finger protein, binds Cas, is a nucleocytoplasmic shuttling protein, and regulates the expression of MMPs.

Comparison of properties of slow pathway potential between successful and unsuccessful radiofrequency applications in patients who underwent catheter ablation for atrioventricular nodal reentrant tachycardia

Findings concerning selective slow pathway radiofrequency ablation for atrioventricular nodal reentrant tachycardia (AVNRT) using the slow pathway potential (SPP) guided method are reported. The electrogram at the SPP recording site showed double potentials consisting of the atrial potential (A) and SPP. However, SPP is usually recorded widely in the right atrial posteroseptal region. To examine whether there was any characteristic marker in the electrogram at the SPP recording site specific to successful RF application, the properties of SPP and its anatomical locations in both successful (S) (38 sites) and unsuccessful (UN) (28 sites) application sites were analyzed in 38 patients who underwent SPP-guided ablation. The distance between the upper margin of the coronary sinus ostium (UCSO) and the ablation catheter (ABL) (DUCSO-ABL) was shorter in S than in UN (2.3 +/- 6.3 mm vs. 9.0 +/- 5.2 mm below the level of UCSO, p < 0.001). The interval between A and SPP (A-SPP) was longer in S than in UN (44.2 +/- 9.9 msec vs. 24.0 +/- 7.0 msec, p < 0.001). RF applications at the more anterior sites with longer A-SPP were more successful than at other sites. The sensitivity and specificity of A-SPP (more than 40 msec) were superior to those of DUCSO-ABL (within 5 mm) as the marker for the successful application (sensitivity; 73.7% v.s. 68.4%, specificity; 100% v.s. 82.1%, respectively). In conclusion, the sites with longer A-SPP might be specific for successful ablation.

Postnatal changes in the types of muscle fibre in the canine inferior pharyngeal constrictor

Deglutition is considered to be immature in infants and to mature postnatally. We evaluated postnatal changes in muscle fibre type composition in the canine inferior pharyngeal constrictor muscle, which consists of the thyropharyngeal (TP) and cricopharyngeal (CP) muscles, using ATPase staining with respect to the maturation of deglutition. In the TP muscle type IIA and type IIB fibres, the main components in the adult, were already predominant at 1 week postnatally. The percentage of primitive type IIC fibre showed a rapid reduction and reached the adult level within 6 weeks. In the CP muscle, the majority of fibres were type IIC at 2 weeks. At 2 months, more than 20% of the fibres were still type IIC and the proportion of type I fibres as a main component in the adult was smaller than that of the adult. None of the puppies younger than 9 weeks old had a fibre type composition similar to that of the adult. In the extensor digitorum longus and flexor digitorum superficialis, the compositions of muscle fibre types became similar to that of the adult at 6 and 9 weeks of age, respectively. Thus, the TP muscle matured more rapidly than the limb muscles, while the CP muscle matured more slowly. We speculated that the TP and CP muscles have specific individual differentiation patterns associated with their functional roles before and after birth, compared with the limb muscles.

Acute relapsing encephalopathy mimicking acute necrotizing encephalopathy in a 4-year-old boy

A 4-year-old boy showed two episodes of encephalitis/encephalopathy involving disturbed consciousness, convulsion, and paresis associated with the elevated levels of protein and myelin basic protein of the cerebrospinal fluid. MRI studies of the brain revealed symmetrical lesions in the brain stem and thalami at the first episode, and additional lesions were found in the cerebellum involving both the gray and white matter in the second episode. The intensities of MRI lesions were low in T I and high in T2. These episodes were followed by an elevation of the anti-viral antibody titers, for influenza A virus during the first episode and for adenovirus during the second. In the second episode, intravenous methylprednisolone therapy resulted in rapid improvement of his neurological signs.