Short coupling with high burden of atrial ectopy in twenty-four hour holter recording predicts recurrence of atrial arrhythmia after atrial fibrillation ablation

Background

Atrial arrhythmia recurrence is experienced in up to 20% of patients after initially receiving a catheter ablation for atrial fibrillation (AF). Therefore, it is important to define predictors of atrial arrhythmia recurrence. Atrial ectopy (AE) with short coupling interval (S-AE) has been reported to be a trigger of AF. On the other hand, high burden of AE has been reported to be a useful predictor of atrial arrhythmia recurrences after AF ablation. Thus, the combination of the incidence of S-AE and AE burden during a 24-hour Holter recording could be a useful predictor of atrial arrhythmia recurrence after AF ablation.

Purpose

To investigate this hypothesis, we performed a retrospective case-controlled study.

Methods

We enrolled 180 patients who underwent their first catheter ablation procedure for AF and performed a 24-hour Holter recording between 90 to 365 days after their ablation procedure. Patients who performed an additional ablation procedure before the Holter recording were excluded. Finally, we analyzed 173 patients (age: 65±10 years, female: 28.3%, non-paroxysmal: 27.7%). The Holter recordings were analyzed by the same experienced technicians. We defined AE as a narrow QRS complex occurring >25% than prior R-R interval, and S-AE as AE occurring >55% earlier than expected. The relationship between the characteristics of AE during the Holter recording and atrial arrhythmia recurrences was investigated.

Results

The Holter recordings were performed at a median of 103 (IQR: 98–138) days after ablation. The median number of AE were 144 (IQR: 54–699) beats per day, and S-AE was recorded in 49 patients (28.3%). Forty-two patients (24.3%) had a recurrence of atrial arrhythmia during a median 488-day follow up period. Patients with S-AE had a recurrence of atrial arrhythmia more frequently than those without S-AE (44.9% vs 16.1%, p<0.001). We found the cut-off point of AE burden as 241 beats per day by the receiver operating characteristic curve with 74% sensitivity and 70% specificity to predict atrial arrhythmia recurrence. We divided the patients into four groups according to the presence or absence of S-AE and high AE burden. In the Kaplan-Meier analysis, patients with S-AE and high AE burden had the highest atrial arrhythmia recurrence rate (Log-rank test: p<0.001). In the Cox multivariate analysis, S-AE with high AE burden was an independent predictor of atrial arrhythmia recurrence (HR: 4.27, 95% CI: 2.32–7.85, p<0.001).

Conclusion

For AF patients who underwent their first catheter ablation, S-AE (>55% earlier than expected) with high AE burden (>241 beats per day) during the 24-hour Holter recording predicted recurrences of atrial arrhythmia. These results can help to develop follow-up strategies after AF ablation.

Funding Acknowledgement

Type of funding source: None

Beijing family Mycobacterium tuberculosis isolated from throughout Japan: phylogeny and genetic features

To estimate the current population genetic structure of Mycobacterium tuberculosis in Japan, phylogenetic traits were analysed for 237 Beijing family strains isolated from tuberculosis patients throughout the country. Unlike previous reports from other countries, the ancient Beijing sublineage was predominant throughout Japan. Clustering analysis based on JATA-VNTR (Japan Anti-Tuberculosis Association variable numbers of tandem repeats), a specialised set of VNTR for the discrimination of Japanese M. tuberculosis strains, revealed high similarity of the modern Beijing sublineage strains, irrespective of their geographic origin. JATA-VNTR might be useful for the phylogenetic classification in populations where ancient Beijing strains are frequently isolated.

Two novel Salp15-like immunosuppressant genes from salivary glands of Ixodes persulcatus Schulze tick

Salp15, a 15-kDa tick salivary gland protein, is known for several suppressive activities against host immunity and critical functions for the transmission of Lyme borrelia in Ixodes scapularis and Ixodes ricinus, the major vectors found in North America and Western Europe. Salp15 inhibits the activation of cluster of differentiation (CD)4(+)T-cells through the repression of T-cell receptor (TCR)-triggered calcium fluxes and interleukin (IL)-2 production. Furthermore, Salp15 adheres to the spirochaeta and specifically interacts with its outer surface protein C. The binding of Salp15 to Borrelia burgdorferi protects it from antibody-mediated killing in vitro. The aim of this study is to identify the Salp15 genes in Ixodes persulcatus Schulze, the specific vector for human Lyme borreliosis in Japan. Two cDNA clones encoding the Salp15-like sequence were obtained from salivary glands of fed female ticks. These genes encode 135- and 132-amino acid proteins, designated Salp15 Iper-1 and Salp15 Iper-2, respectively, both having signal peptide sequences and predicted to be secretory proteins. Salp15 Iper-1 and -2 showed 51.8 and 68.2% similarity to I. scapularis Salp15, respectively. Reverse transcriptase PCR analysis showed that Salp15 Iper genes were expressed specifically in the salivary glands throughout life cycle stages of the ticks and were up-regulated by blood feeding. In the I. persulcatus-derived sequences, the C-terminal part, which is the binding domain to the CD4 molecule of T-cells in I. scapularis Salp15, was well conserved. In the future, it will be necessary to analyse immunosuppressive functions of I. persulcatus Salp15 and their interaction with Borrelia spp. in Japan.

Scoring of reflux symptoms associated with scleroderma and the usefulness of rabeprazole

OBJECTIVE

The high frequency of gastroesophageal reflux disease (GERD) as a complication of scleroderma (systemic sclerosis, SSc) calls for treatment with powerful acid suppressants such as proton pump inhibitors (PPI). The present study used a GERD-specific questionnaire to assess the symptoms of GERD in SSc patients, and examine the effectiveness of rabeprazole (RPZ) for treating the symptoms of GERD.

METHODS

The Frequency Scale for the Symptoms of GERD (FSSG), a medical questionnaire developed in Japan for evaluating GERD, and the Visual Analogue Scale (VAS) were used to evaluate GERD symptoms and the degree of pain, respectively, in 151 SSc subjects. These tools were also used to assess the effect of 8 weeks' treatment with the PPI RPZ (10 mg/day).

RESULTS

Data on age and gender, and FSSG and VAS scores before treatment and after 4 and 8 weeks' RPZ treatment, were available for 84 subjects. The mean FSSG score was 13.9+/-9.7 before treatment, 8.3+/-8.1 after 4 weeks of treatment, and 7.0+/-7.0 after 8 weeks of treatment; the score reduction was significant (p<0.001) indicating the effectiveness of RPZ in improving subjective GERD symptoms. The VAS scores revealed a significant improvement in pain after both 4 and 8 weeks compared with baseline scores. Six subjects experienced adverse effects and five discontinued the analysis during the period.

CONCLUSION

Administration of RPZ 10 mg/day is effective for the control of the symptoms of GERD associated with SSc. In addition to assessing the symptoms of GERD, the FSSG questionnaire can be used to evaluate the therapeutic effect of drugs.

Molecular epidemiology of Mycobacterium tuberculosis in an urban area in Japan, 2002-2006

SETTING

Shinjuku City, Tokyo, Japan.

OBJECTIVE

To evaluate the status of transmission of Mycobacterium tuberculosis in Shinjuku City to allocate resources efficiently and effectively for a successful tuberculosis (TB) control programme.

DESIGN

Observational descriptive study combining the genotype data of M. tuberculosis with TB patient profiles.

RESULTS

The genotype clustering rate was significantly higher in males (adjusted odds ratio [aOR] 1.94, 95%CI 1.04-3.65, P = 0.038), patients aged <40 years (aOR 2.09, 95%CI 1.17-3.71, P = 0.012) and the homeless (aOR 2.72, 95%CI 1.42-5.20, P = 0.002), and was lower for the foreign-born (aOR 0.21, 95%CI 0.06-0.76, P = 0.017). Among 45 genotype clusters containing 152 TB patients, 26 clusters containing 102 patients (67.1%) were composed of a mix of homeless and non-homeless patients. One of the mixed clusters included an 8-month-old infant born in Japan.

CONCLUSION

The study revealed that M. tuberculosis transmission occurred more frequently among the homeless than in non-homeless persons. However, transmission by casual contact between the homeless and the general population was also shown to occur.

Fulminant type 1 diabetes as a high risk group for diabetic microangiopathy--a nationwide 5-year-study in Japan

AIMS/HYPOTHESIS

The aim of the present study was to assess the development of microangiopathy in patients with fulminant type 1 diabetes, a novel subtype of type 1B diabetes.

MATERIALS AND METHODS

In a nationwide survey, we followed 41 patients with fulminant type 1 diabetes and 76 age- and sex-matched patients with type 1A diabetes for 5 years. The following data were recorded every 12 months after the onset of diabetes: seven-point blood glucose concentrations, HbA1c level, urinary albumin excretion, serum C-peptide level, blood pressure, daily dosages of insulin, frequency of severe hypoglycaemic episodes, and neurological and fundoscopic examination.

RESULTS

The 5-year cumulative incidence of microangiopathy was 24.4% in fulminant type 1 diabetes and 2.6% in type 1A diabetes. In longitudinal studies using the Kaplan-Meier method, the cumulative incidence of each form of microangiopathy was significantly higher in fulminant type 1 diabetes than in type 1A diabetes; retinopathy was 9.8% vs 0% (p=0.014), nephropathy 12.2% vs 2.6% (p=0.015) and neuropathy 12.2% vs 1.3% (p=0.010), respectively. Mean HbA1c levels were similar in the fulminant and type 1A diabetes groups during the follow-up periods. However, the mean M-value, mean insulin dosages and the frequency of severe hypoglycaemic episodes were significantly higher, and the mean postprandial C-peptide level was significantly lower in the fulminant type 1 diabetes group.

CONCLUSIONS/INTERPRETATION

These data suggest that patients with fulminant type 1 diabetes are a high-risk subgroup for diabetic microangiopathy associated with the lack of endogenous insulin secretion from the onset of diabetes.

Relationship of lipoprotein lipase and hepatic triacylglycerol lipase activity to serum adiponectin levels in Japanese hyperlipidemic men

OBJECTIVE

The aim of this study was to determine how lipoprotein lipase (LPL) and hepatic triacylglycerol lipase (HTGL) activity relate to serum adiponectin levels.

RESEARCH DESIGN AND METHODS

Fifty-five hyperlipidemic Japanese men were recruited for this study. LPL and HTGL activity in post-heparin plasma (PHP) was measured using Triton X-100 emulsified-[14C] triolein. The remaining activity in the presence of 1M NaCl was defined as HTGL activity. Serum adiponectin levels were determined by an enzyme-linked immunosorbent assay system.

RESULT

LPL activity had a positive relationship with HDL2, but had no relation with HDL3, while HTGL had positive relationship with HDL3, but had no relationship with HDL2. LPL activity showed a positive relationship [r = 0.345, p = 0.010] to serum adiponectin levels, while and HTGL activity showed an inverse relationship [r = - 0.365 p = 0.006]. Multiple regression analysis with LPL and HTGL as dependent variables and age, BMI, serum adiponectin and the homeostasis model assessment of insulin resistance (HOMA-IR) as independent variables showed LPL and HTGL's association to adiponectin did not persist after adjustments for these covariants. However, the association of LPL activity to HOMA-IR was found to persist after adjustments of age, BMI, and serum adiponectin.

CONCLUSIONS

There was a co-linearity between insulin sensitivity and adiponectin as well as insulin sensitivity and LPL/HTGL activity.

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.

Possible involvement of protein kinases and Smad2 signaling pathways on osteoclast differentiation enhanced by activin A

Bone tissues reportedly contain considerable amounts of activin A and follistatin, an activin A-binding protein. In the present study, we found that follistatin strongly inhibited osteoclast formation in cocultures of mouse bone marrow cells and primary osteoblasts induced by 1alpha,25 dihydroxyvitamin D(3), prostaglandin E(2), and interleukin-1alpha. Antibody aganist activin A also inhibited the osteoclast formation. Furthermore, activin A synergistically stimulated osteoclast differentiation mediated by receptor activator NF-kappaB ligand (RANKL). RT-PCR analysis revealed that osteoblasts produced not only activin A but also follistatin. Western blot analysis of a panel of phosphorylated proteins revealed that activin A stimulated the phosphorylation of p44/42 mitogen activated protein (MAP) kinase (ERK1/2) and p38 MAP kinase in macrophage colony-stimulating factor-dependent bone marrow macrophages (M-BMMPhis). In addition, phosphorylation of Smad2 was observed in M-BMMPhis stimulated with activin A. These findings indicate that the phosphorylation of p44/42 MAP kinase, p38 MAP kinase, and Smad2 is involved in activin A-enhanced osteoclast differentiation induced by RANKL. Taken together, these results suggest that both activin A and follistatin produced by osteoblasts may play an important role in osteoclast differentiation through MAP kinases and Smad2 signaling pathways.

Osteoclast differentiation is associated with transient upregulation of cyclin-dependent kinase inhibitors p21(WAF1/CIP1) and p27(KIP1)

Osteoclasts, bone-resorbing multinucleated cells, develop from monocyte-macrophage lineage cells in the presence of osteoclast differentiation factor (ODF, also called RANKL/TRANCE/OPGL) and macrophage colony-stimulating factor (M-CSF). M-CSF-dependent bone marrow macrophages (M-BMMPhis) from mouse bone marrow cells have been shown to differentiate into osteoclast-like multinucleated cells (OCLs) in the presence of soluble ODF/RANKL (sODF/RANKL) and M-CSF within 3 days. In this study, we found that stimulation of M-BMMPhis with sODF/RANKL induced a transient expression of cyclin-dependent kinase inhibitors (CDK inhibitors) p21(WAF1/CIP1) and p27(KIP1) by 24 h. The CDK inhibitor proteins disappeared by 48 h. Tumor necrosis factor alpha (TNF-alpha), which is reported to stimulate OCL differentiation, stimulated p21(WAF1/CIP1) and p27(KIP1) expression in M-BMMPhis as well. However, M-CSF alone did not stimulate the expression of the two CDK inhibitors. To clarify the role of p21(WAF1/CIP1) and p27(KIP1) in osteoclastogenesis, accumulation of these CDK inhibitors was aborted by antisense oligonucleotides. Treatment with p21(WAF1/CIP1) antisense oligonucleotide alone, or p27(KIP1) antisense oligonucleotide alone, showed a limited inhibitory effect on OCL formation. However, treatment with a mixture of these two antisense oligonucleotides strongly inhibited OCL formation. These results suggest that a combined modulation of the CDK inhibitors p21(WAF1/CIP1) and p27(KIP1) may be involved in osteoclast differentiation induced by ODF/RANKL.

Comparison of urine cytology between the ileal conduit and Indiana pouch

OBJECTIVE

To compare the cytomorphologic features of urine obtained from two different kinds of urinary diversions constructed after total bladder resection.

STUDY DESIGN

The smears of urine from 11 ileal conduits and 6 Indiana pouches were evaluated. All patients underwent total bladder resection due to transitional cell carcinoma (TCC) or other kinds of cancer before urine diversion.

RESULTS

The cytologic features of Indiana pouch urine include degenerated, small, round cells without columnar cells derived from intestinal epithelium. In ileal conduit urine, well-preserved columnar cells and degenerated, small, round cells were frequently observed. The columnar cells in ileal conduit urine exhibited cytologic features that should be distinguished from TCC cells.

CONCLUSION

The method of reconstructing the urinary tract is important in urine cytology from urine diversions because the cytomorphologic features of urine are different between the two kinds of urinary diversions. Since columnar cells in ileal conduit urine might lead to misdiagnosis as TCC, special consideration is required to examine ileal conduit urine.

Bone morphogenetic protein-2 enhances osteoclast formation mediated by interleukin-1alpha through upregulation of osteoclast differentiation factor and cyclooxygenase-2

Bone morphogenic protein-2 (BMP-2) is a member of the transforming growth factor beta (TGF-beta) superfamily. While BMP-2 is capable of inducing bone formation ectopically, little is known about its role on osteoclastogenesis. In this study, we examined the effect of BMP-2 on osteoclast-like multinucleated cell (OCL) formation in cocultures of osteoblast-like cells and hematopoietic cells of bone marrow origin. BMP-2 alone did not stimulate OCL formation in this culture system; however, it strongly enhanced OCL formation in a dose-dependent fashion in the presence of interleukin-1alpha (IL-1alpha). Western blot analysis showed that a simultaneous addition of BMP-2 and IL-1alpha synergistically enhanced cyclooxygenase-2 (COX-2) expression in osteoblast-like cells. Moreover, Northern blot analysis revealed that the level of osteoclast differentiation factor (ODF) mRNA increased by treatment with BMP-2 and IL-1alpha in osteoblast-like cells. It is noted that BMP-2 alone did cause an increase in the expression of both COX-2 and ODF genes. The stimulatory effect of BMP-2 was abolished by adding nonsteroidal anti-inflammatory drugs, such as indomethacin and a selective COX-2 inhibitor NS-398. Addition of NS-398 inhibited the expression of the ODF gene in osteoblast-like cells treated with BMP-2 and IL-1alpha. These results indicated that the combination of BMP-2 and IL-1alpha stimulated osteoblast-like cells to elevate the expression of both COX-2 and ODF genes, resulting in an enhanced OCL formation. Since BMP-2 alone induced the expression of COX-2 and ODF genes in osteoblast-like cells, it appears to be one of the regulating factors of osteoclastogenesis.

Assay of 222Rn in water samples by a modified integral counting method

22Rn activity concentrations in water collected from 163 private wells and 14 springs in Tokyo were measured with a liquid scintillation spectrometer using a modified integral counting method. The activity concentrations of 222Rn range from 0.2 to 22.9 Bq/L and average 4.8 Bq/L. The errors due to the air luminescence counts and the interferences from 220Rn and 219Rn are discussed and evaluated. 222Rn samples of 0.2 Bq/L can be assayed within an overall uncertainty of 3.1%. The liquid scintillation method involving agitation of the sample water directly with a liquid scintillation cocktail was compared with the present method and evaluated.

Cord blood IgE against milk and egg antigens

The aim of the present study was to reevaluate the prenatal production of specific IgE for eggs and milk and, in those cases, to determine whether there is a relation to the amount of maternal egg and milk intake. Total and specific IgEs from 160 cord blood-samples were determined by immunoassays using a paramagnetic particle solid phase and an enzyme-mediated chemiluminescent reaction for signal detection. The levels of cord blood IgE for total, egg, and milk were 0.63 +/- (SD) 1.10 IU/ml, 0.020 +/- 0.055, and 0.036 +/- 0.053 IU/ml, respectively. IgE levels specific to egg and milk over 0.03 IU/ml were observed in 33 and 70 out of 160 cases, respectively. To address whether the maternal intake of eggs and milk affects the level of cord blood IgEs, all mothers except 9 were interviewed, and the amount of eggs and milk taken during pregnancy was recorded. No correlation was seen between egg and milk intakes and cord blood IgE levels. Our data demonstrate a high incidence of the prenatal production of specific IgE for eggs and milk which is independent of maternal egg and milk intakes.

[Effect of posture strategies on preventing aspiration]

The purpose of this study was to determine the effect of postural change on preventing aspiration, and the types of swallowing disorder that were influenced by posture. Ninety-five patients that were examined by aspiration of barium during videofluoroscopic examination of oropharyngeal swallow assumed one of four postures (chin down, head rotation, chin down + head rotation, and head back to chin down). Postural strategies were successful in eliminating aspiration in 68(72%) of the 95 patients. Twenty five of the 68 patients, however, needed an additional change in bolus volume to eliminate aspiration. Effective postures eliminating aspiration were chin down for 43 patients, head rotation for 10 patients, chin down + head rotation for 12 patients, and head back to chin down for 3 patients. The successes rates of posture changes for each swallowing abnormality were 76% for reduced tongue base retraction, 74% for delay in triggering pharyngeal swallow, 74% for reduced laryngeal elevation, 73% for laryngeal paralysis, 68% for inefficient oral transit, and in 57% for cricopharyngeal dysfunction. Among individuals with cricopharyngeal dysfunction or with than three swallowing motility problems, the frequency of unsuccessful swallow despite postural change was significantly higher than that of successful swallow. These results indicated that the posture strategies in addition to control of bolus volume could prevent aspiration in more than 70% of patients, but the efficacy of posture techniques differed with the different types of swallowing disorder identified as causing the aspiration, and suggested that the posture strategies were less beneficial in individuals with cricopharyngeal dysfunction or exhibiting multiple swallowing disorders.