BK Channels in the Vascular System.

Autoregulation of blood flow is essential for the preservation of organ function to ensure continuous supply of oxygen and essential nutrients and removal of metabolic waste. This is achieved by controlling the diameter of muscular arteries and arterioles that exhibit a myogenic response to changes in arterial blood pressure, nerve activity and tissue metabolism. Large-conductance voltage and Ca(2+)-dependent K(+) channels (BK channels), expressed exclusively in smooth muscle cells (SMCs) in the vascular wall of healthy arteries, play a critical role in regulating the myogenic response. Activation of BK channels by intracellular, local, and transient ryanodine receptor-mediated "Ca(2+) sparks," provides a hyperpolarizing influence on the SMC membrane potential thereby decreasing the activity of voltage-dependent Ca(2+) channels and limiting Ca(2+) influx to promote SMC relaxation and vasodilation. The BK channel α subunit, a large tetrameric protein with each monomer consisting of seven-transmembrane domains, a long intracellular C-terminal tail and an extracellular N-terminus, associates with the ß1 and γ subunits in vascular SMCs. The BK channel is regulated by factors originating within the SMC or from the endothelium, perivascular nerves and circulating blood, that significantly alter channel gating properties, Ca(2+) sensitivity and expression of the α and/or ß1 subunit. The BK channel thus serves as a central receiving dock that relays the effects of the changes in several such concomitant autocrine and paracrine factors and influences cardiovascular health. This chapter describes the primary mechanism of regulation of myogenic response by BK channels and the alterations to this mechanism wrought by different vasoactive mediators.

Aging effect on plasma metabolites and hormones concentrations in riding horses.

Age effects on plasma metabolites, hormone concentrations, and enzyme activities related to energy metabolism were investigated in 20 riding horses. Animals were divided into two groups: Young (3-8 years) and aged (11-18 years). They were clinically healthy, and not obese. Plasma adiponectin (ADN) concentrations in aged horses were significantly lower than those in young horses (mean±SE, 6.5±1.3 µg mL(-1) vs, 10.9±1.7 µg mL(-1), Mann-Whitney U test, respectively; P=0.0233). Plasma non-esterified fatty acid levels and Insulin and malondialdehyde concentrations in aged group tended to increase compared to those in young group although there were not significant differences statistically. In aged group, malate dehydrogenase/lactate dehydrogenase (M/L) ratio, which is considered an energy metabolic indicator, did not change significantly compared to that in young group. Present data suggest that aging may negatively affect nutrition metabolism, but not induce remarkable changes in M/L ratio in riding horses.

Legionella pneumophila contamination in a steam towel warmer in a hospital setting.

For prevention of nosocomial legionellosis, environmental investigation to identify possible infectious sources is essential. An environmental study in a ward of our hospital revealed that a steam towel warmer was contaminated with legionella whereas no legionella was detected in tap water supplies and shower heads. Water in the apparatus may be a reservoir of legionella. We abandoned the use of all steam towel warmers in our hospital. Based on this finding, we recommend that steam towel warmers in hospital settings be avoided. Otherwise, the apparatus should be drained, cleaned and dried every day.

[Full-thickness resection of the focus site for adolescent idiopathic ventricular tachycardia].

We present a case of a 14-year-old male with incessant idiopathic ventricular tachycardia for which both pharmacological and catheter ablation treatments failed. Curative surgery was performed on this patient. By intraoperative epicardial isochronous mapping, arrhythmogenic focus was identified in the right ventricular infundibulum between the large conus branch and the proximal right ventricular coronary branch. After cryoablation both from the epi- and endo-cardial sides failed to terminate the arrhythmia, subsequent full-thickness resection of the identified focus was performed. There was no postoperative recurrence of tachyarrhythmia In idiopathic ventricular tachycardia, arrhythmogenic focus is not always situated on the endo- or epicardial side. Full-thickness resection of the focus site might be necessary in such patients as we experienced this time.

[Volume reduction surgery for giant coronary sinus with valvular heart disease; report of a case].

A 64-year-old male with giant left atrium and giant coronary sinus, who had aortic valve regurgitation, prosthesis valve paravalvular leakage in mitral position and prosthesis valve malfunction in tricuspid valve position, was successfully treated with double valve replacement, paravalvular leakage repair and volume reduction of left atrium and coronary sinus. Giant coronary sinus was about 70 mm in diameter and was thought to be induced by persistent left superior vena cava, high right atrium pressure and prosthesis valve malfunction in tricuspid valve position. Lung volume was so much increased by volume reduction of left atrium and coronary sinus and patient's symptoms were much improved.

[Reoperation for postoperative pseudoaneurysm after repair for acute aortic dissection associated with disseminated intravascular coagulation and chronic renal failure].

We report a very high risk case of reoperation for pseudoaneurysm after ascending aortic replacement for acute aortic dissection in a 78-year-old man with chronic renal failure and disseminated intravascular coagulation (DIC). Computed tomography 5 years after the 1st operation showed huge pseudoaneurysm originated from the distal anastomosis and the angiogram showed moderate aortic regurgitation. Hemodialysis and congestive heart failure associated with DIC complicated his general condition. Preoperative DIC score was 7 with D-dimer of 39.8 microg/ml. The patient underwent reoperation through night anterior thoracotomy. At 20 degrees C of urinary bladder temperature, we started re-median sternotomy and ablated the adhesion. When the pseudoaneurysm ruptured, we started hypothermic circulatory arrest with selective cerebral perfusion immediately. And Bentall operation and hemi-arch replacement were performed. Postoperative recovery required long period and he was transferred to another hospital at 3 months after the surgery. Postoperative data showed reduction of DIC score to 3.

Soluble interleukin-1 receptor type II levels in gingival crevicular fluid in aggressive and chronic periodontitis.

BACKGROUND: Interleukin (IL)-1 is closely related to the initiation and progression of periodontal disease. IL-1 levels in the gingival crevicular fluid (GCF) of subjects with periodontitis are higher than those in periodontally healthy controls, and the levels of IL-1 correlate with disease severity. However, soluble IL-1 receptor type II (sIL-1RII), which acts as a decoy receptor for IL-1s, has not been investigated in detail in periodontal disease. The purpose of this study was to measure sIL-1RII levels in the GCF of subjects with chronic or aggressive periodontitis; the correlation between the sIL-1RII levels in GCF and clinical parameters also was examined. METHODS: IL-1beta and sIL-1RII were measured in 64 GCF samples collected from 47 subjects with chronic periodontitis (CP) and 17 subjects with aggressive periodontitis (AgP). The clinical characteristics of each site were recorded at the time of GCF sampling. IL-1beta and sIL-1RII were measured by specific non-cross-reactive enzyme-linked immunosorbent assay. RESULTS: The disease severity was comparable in CP and AgP. IL-1beta was detected in 98% of CP GCF samples and 88% of AgP GCF samples. sIL-1RII was detected in 55% of CP GCF samples and 35% of AgP GCF samples. However, the concentrations of IL-beta and sIL-1RII detected in GCF from subjects with CP or AgP were similar. CONCLUSION: sIL-1RII was detected more often in CP GCF than in AgP GCF, and there was no correlation between GCF sIL-1RII concentration and clinical parameters.

[Mitral valve plasty for a 91-year-old woman with mitral valve prolapse].

We reported a successful mitral valve plasty for a 91-year-old woman with mitral valve prolapse. She has lived healthfully and independently without a big problem. She was admitted to another hospital for acute heart failure. Echo cardiography revealed prolapse of posterior mitral valve leaflet and severe mitral regurgitation. Drug therapy was not enough to control her complaint In spite of her age, the patient was able to support herself, and she and her family desired to have a surgical treatment. Therefore she referred to our hospital and underwent mitral valve plasty. Post operative course was almost uneventful. She discharged the hospital 3 months after the operation. If a selective criteria for individual patients is applied, the nonagenarian can safety undergo cardiac surgery.

Detection of legionella species in clinical samples: Comparison of polymerase chain reaction and urinary antigen detection kits.

BACKGROUND: Recently, two excellent methods have been used for the diagnosis of Legionnaires' disease: urinary antigen detection and PCR. The purpose of the present study is to analyze and evaluate the sensitivity and specificity of three different urinary antigen detection kits as well as PCR. MATERIALS AND METHODS: A total of 148 samples were collected from 33 patients between 1993 and 2004. These consisted of 73 urine samples obtained from 33 patients, 57 serum samples provided by 29 patients, and 18 respiratory tract specimens from 13 patients. Three commercially available kits were used to detect urinary antigen. For the 5S PCR reaction, primers L5SL2 and L5SR84 were used. RESULTS: Positive results were shown in all patients' urine (representing 79.5% of total samples) using the Binax EIA kit, in 93.9% patients (representing 75.3% samples) using the Binax NOW immunochromatographic kit, and in 90.9% (representing 72.6% samples) using the Biotest EIA kit. Urine samples from 12.1% patients (representing 6.8% of total samples), serum samples from 41.4% patients (representing 35.1% of total samples), and respiratory samples from 84.6% patients (representing 88.9% of total samples) showed positive results with PCR. CONCLUSION: In testing urine of legionellosis patients, it was suggested that three kits were all valuable tools for diagnosis of legionellosis. Since over one-third of patients' serum samples and most respiratory specimens showed positive results with PCR, the addition of PCR for testing of these samples might be useful, particularly in cases of culture negative and serum antibody negative patients.

[Valve-in-valve replacement of primary tissue valve failure of bovine pericardial valve minor].

A 73-year-old woman who underwent mitral valve replacement with a 31 mm Carpentier Edwards Pericardial Xenograft 19 years ago. She revealed sudden onset of a grade IV/VI a seagull like diastolic murmur at the apex, and severe hematuria. Echocardiography demonstrated severe mitral regurgitation. These findings were consistent with acute primary tissue valve failure. Therefore we performed emergency reoperation. At operation, valve leaflet was torn at the commissural stitch, and bioprosthesis strut was buried in the left posterior ventricular wall. The mitral prosthetic valve replaced with a 25 mm CarboMedics OptiForm using a technique of valve-in-valve replacement. This procedure would be one option for replacement of bioprosthetic mitral valve.

Actinobacillus actinomycetemcomitans Y4 capsular polysaccharide induces IL-1beta mRNA expression through the JNK pathway in differentiated THP-1 cells.

Capsular polysaccharide from Actinobacillus actinomycetemcomitans Y4 (Y4 CP) induces bone resorption in a mouse organ culture system and osteoclast formation in mouse bone marrow cultures, as reported in previous studies. We also found that Y4 CP inhibits the release of interleukin (IL)-6 and IL-8 from human gingival fibroblast (HGF). Thus Y4 CP induces various responses in localized tissue and leads to the secretion of several cytokines. However, the effects of Y4 CP on human monocytes/macrophages are still unclear. In this study, THP-1 cells, which are a human monocytic cell line, were stimulated with Y4 CP, and we measured gene expression in inflammatory cytokine and signal transduction pathways. IL-1beta and tumour necrosis factor (TNF)-alpha mRNA were induced from Y4 CP-treated THP-1 cells. IL-1beta mRNA expression was increased according to the dose of Y4 CP, and in a time-dependent manner. IL-1beta mRNA expression induced by Y4 CP (100 microg/ml) was approximately 7- to 10-fold greater than that in the control by real-time PCR analysis. Furthermore, neither PD98059, a specific inhibitor of extracellular signal-regulated kinase nor SB203580, a specific inhibitor of p38 kinase prevented the IL-1beta expression induced by Y4 CP. However, JNK Inhibitor II, a specific inhibitor of c-Jun N-terminal kinase (JNK) prevented the IL-1beta mRNA expression induced by Y4 CP in a concentration-dependent manner. These results indicate that Y4 CP-mediated JNK pathways play an important role in the regulation of IL-1beta mRNA. Therefore, Y4 CP-transduced signals for IL-1beta induction in the antibacterial action of macrophages may provide a therapeutic strategy for periodontitis.

In vitro biocompatibility of a new titanium-29niobium-13tantalum-4.6zirconium alloy with osteoblast-like MG63 cells.

BACKGROUND: Titanium-29niobium-13tantalum-4.6zirconium (TiNb) has recently been developed as a new implant material. TiNb is composed of non-toxic elements and has a lower modulus of elasticity than the other titanium alloys. However, its biocompatibility has not been adequately characterized. The aim of this study was to evaluate the biocompatibility of TiNb using an osteoblast-titanium co-culture system. METHODS: MG63 cells were cultured on three kinds of titanium disks: TiNb, pure titanium (pTi), and titanium-6aluminum-4vanadium (TiAl), prepared with two different surfaces, a polished and acid-etched surface and a machined-grooved surface. The surface topography and roughness were evaluated by scanning electron microscopy (SEM). After 48 hours culture, the number of proliferating cells and prostaglandin E2 (PGE2) production in the culture supernatant were determined. RESULTS: There was no significant difference in surface roughness among the three titanium disks with a polished and acid-etched surface. After 48 hours of culture, the number of cells was significantly reduced on pTi and TiAl compared to TiNb and the control. PGE2 production was significantly higher on pTi than on TiAl, TiNb, and the control. We further examined the effect of surface roughness on PGE2 production using machine-grooved titanium disks. While pTi and TiAl stimulated the production of PGE2 depending on surface roughness, roughened TiNb did not affect PGE2 production. CONCLUSIONS: These results suggest that TiNb may exhibit favorable biocompatibility because it has an efficient surface topography for cell proliferation, and the level of PGE2 production does not depend on surface roughness. We conclude that TiNb may be useful as an implant material.

Cdc6 expression as a marker of proliferative activity in brain tumors.

Antibodies against human proteins that regulate DNA replication such as Cdc6 and Mcm5 became available as a new marker of proliferation. We performed immunohistochemical analysis with MIB-1 and antibody against Cdc6 on 35 brain tumors, including tumors of neuroepithelial tissue, vestibular schwannomas, meningiomas, and pituitary adenomas. Median reactivity for MIB-1 was 8.8%, and that for Cdc6 was 55%. Reactivity in most brain tumors was significantly higher for Cdc6 than for MIB-1, but reactivity of Cdc6 was independent of tumor grade. Detection of Cdc6 expression might be useful for the estimation of proliferative activity in brain tumors.

Role of FK506-binding protein 12 in development of the chick embryonic heart.

A cDNA encoding chicken FK506-binding protein 12 (FKBP12) was isolated and sequenced. The predicted amino acid sequence of the chicken protein shows high homology to those of FKBP12 proteins of other species ranging from human to frog. The possible role of FKBP12 in chick embryonic cardiac development was examined. Northern blot analysis revealed that FKBP12 mRNA is distributed widely in chick embryos, being especially abundant in the heart; the amount of FKBP12 mRNA in the embryonic heart decreased with time. Administration of FK506 to chick embryos at 7 to 9 days resulted in marked cardiac enlargement. FK506 also reduced the expression of myosin, induced a more elongated cell morphology, and impaired network formation in cultured chick embryonic cardiomyocytes. These results suggest that FKBP12 is important in the regulation of contractile function and phenotypic expression in chick cardiomyocytes during embryonic development.

Effect of repeated local minocycline administration on periodontal healing following guided tissue regeneration.

BACKGROUND: Infection after a periodontal surgical site has been prepared for guided tissue regeneration (GTR) is one of the common complications that can compromise healing. The purpose of this study was to assess the effect of repeated local antimicrobial therapy following GTR for improving clinical attachment gains, and to histologically evaluate the various cell populations and bacterial contamination of the retrieved expanded polytetrafluoroethylene membrane (ePTFE). METHODS: Forty periodontal intrabony defects in 40 patients were treated by a flap procedure that included the use of ePTFE membranes to allow GTR. Patients were randomly assigned to 2 treatment groups: 20 patients were treated with the ePTFE alone (control group), and the other 20 were treated with the ePTFE combined with the administration of a weekly repeated local application of minocycline ointment for 8 weeks after membrane placement (test group). The membranes were retrieved 6 weeks after the initial surgery and sectioned serially in a coronal-apical plane. The sections were then divided into 9 fields and examined by light microscopy for the presence of inflammatory cells and oral bacteria. Clinical measurements were taken at the time of baseline examination and at a 6-month follow-up examination after removal of the ePTFE. RESULTS: At the 6-month follow-up examination, control and test groups showed significant improvement; i.e., reduction in the probing depth and increased clinical attachment gain compared with the values at the baseline examination. However, the mean clinical attachment gain of the test group (3.0+/-0.3 mm) was significantly (P = 0.03) greater than that of the control group (2.0+/-0.5 mm). Histologically, the total number of the cells of both groups was similar. In both groups, mononuclear cells were dominant and fibroblasts, neutrophils, and plasma cells were rarely encountered. There was a tendency for the number of macrophages to be somewhat higher in the control group. The total number of bacteria in the test group was significantly less than that in the control group. The number of bacteria in both control and test groups decreased toward the apical portion. CONCLUSIONS: In the present study, clinical attachment gain of intrabony defects following GTR was favorable with repeated local administration of minocycline ointment. However, a complete microbial eradication was not achieved.

Macrophage inflammatory protein-1alpha is an osteoclastogenic factor in myeloma that is independent of receptor activator of nuclear factor kappaB ligand.

A complementary DNA expression library derived from marrow samples from myeloma patients was recently screened and human macrophage inflammatory protein-1alpha (hMIP-1alpha) was identified as an osteoclastogenic factor expressed in these samples. hMIP-1alpha enhanced osteoclast (OCL) formation in human marrow cultures and by highly purified OCL precursors in a dose-dependent manner (5-200 pg/mL). Furthermore, hMIP-1alpha enhanced OCL formation induced by human interleukin-6 (IL-6), which is produced by marrow stromal cells when they interact with myeloma cells. hMIP-1alpha also enhanced OCL formation induced by parathyroid hormone-related protein (PTHrP) and receptor activator of nuclear factor kappaB ligand (RANKL), factors also implicated in myeloma bone disease. Time-course studies revealed that the hMIP-1alpha acted during the last 2 weeks of the 3-week culture period. Reverse transcription-polymerase chain reaction analysis showed that the chemokine receptors for hMIP-1alpha (CCR1 and CCR5) were expressed by human bone marrow and highly purified early OCL precursors. Furthermore, hMIP-1alpha did not increase expression of RANKL. These data demonstrate that hMIP-1alpha is an osteoclastogenic factor that appears to act directly on human OCL progenitors and acts at the later stages of OCL differentiation. These data further suggest that in patients with myeloma, MIP-1alpha produced by myeloma cells, in combination with RANKL and IL-6 that are produced by marrow stromal cells in response to myeloma cells, enhances OCL formation through their combined effects on OCL precursors. (Blood. 2001;97:3349-3353)

Distribution of Legionella longbeachae and other legionellae in Japanese potting soils.

The distribution of Legionella longbeachae and Legionella spp. in Japanese potting soils was examined. Thirty samples were collected: 13 were composted wood products, 11 were potting mixes (containing composted wood products, sand, mineral fertilizer, and manure), 2 were peatmoss, 3 were peatmoss-sand mixes (containing peatmoss and sand), and 1 was a sample of hydroponic clay balls. A suspension of each sample was made in sterile distilled water and acidified, and 100 microl was plated on buffered charcoal yeast extract alpha (BCYEalpha) agar containing modified wadowsky yee (MWY) supplement and pimaricin (direct method). In parallel, each suspension was incubated at 33 degrees C for several months to allow for amebic enrichment, if present; the suspensions were then plated onto culture media as described above (enrichment method). A total of 46 strains of legionellae were isolated from 22 of the 24 samples (13 composted wood products, 11 potting mixes). L. longbeachae was isolated from 9 samples. The most predominant species of legionellae in potting soils was Legionella bozemanii, which was isolated from 13 samples. Legionella spp. and L. micdadei were isolated from 8 and 7 samples each. Compared with findings in potting soils in Australia (26/45; 58%), Japanese potting soils had an only 8.3% (2/24) isolation rate for L. longbeachae by the direct method. The components of composted wood products were broadleaves such as oak and Japanese oak, in contrast to the pine and eucalypt used in Australia, which may account for the different isolation rates. However, the amebic enrichment method was useful in increasing the recovery of legionellae in potting soils. Legionellae were not isolated from the peatmoss samples, a result identical to findings in surveys of similar material in Europe.

Expression pattern of novel chick T-box gene, Tbx20.

Little is known about the molecular mechanisms involved with the initial specifications of the cardiac mesoderm. In order to identify potential regulatory factors that play important roles in early heart specification, we attempted to isolate the chick H15-related T-box gene and analyze its expression pattern during early development. The chick Tbx20 gene was found to be highly homologous to human, mouse, and zebrafish hrT/Tbx20. Its expression was initially detected in the posterior lateral mesoderm, after which it expanded to the anterior and was intensively co-expressed with a cardiogenic gene, Nkx2.5, in the anterior lateral mesoderm.