Hysterectomy and risk of osteoarthritis in women: a nationwide nested case-control study.

OBJECTIVE: Hysterectomy is the most common gynaecological surgery, performed mainly for benign uterine pathologies in women. Studies have suggested that hysterectomy is associated with osteoarthritis (OA); however, the association remains controversial. This study aimed to investigate the association between hysterectomy and the risk of OA. METHOD: We performed a population-based nested case-control study using the National Health Insurance programme database from 2000 to 2016 in Taiwan. All medical conditions for each case and control were categorized using the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) and ICD-10. A multiple conditional logistic regression model was applied to analyse the adjusted odds ratio (aOR) and 95% confidence interval (CI) for the association between hysterectomy and OA. RESULTS: Our analyses included 16 592 patients with OA and 66 368 matched controls. After adjustment for possible confounders, hysterectomy had a significant association with OA (aOR = 1.19, 95% CI = 1.09-1.30), especially knee OA (aOR = 1.25, 95% CI = 1.13-1.38). Furthermore, women who received oestrogen therapy (ET) alone and patients who underwent hysterectomy without ET showed a greater risk of OA development compared to women who did not receive ET (aOR = 1.14, 95% CI = 1.07-1.23, and aOR = 1.19, 95% CI = 1.08-1.31, respectively). CONCLUSION: Our findings indicate that hysterectomy is associated with OA, especially knee OA. We also found that women who received ET alone and patients who underwent hysterectomy without ET had an increased risk of OA.

Effects of fermented soybean meal with Bacillus velezensis, Lactobacillus spp. or their combination on broiler performance, gut antioxidant activity and microflora.

OBJECTIVE: A series of experiment were conducted to evaluate the effects of replacing a part of soybean meal (SBM) at 6% of broiler diets with fermented soybean meal (FSBM) obtained by single or two-stage fermentation by measuring growth performance, antioxidant activity in the jejunum and distal intestinal microflora. METHODS: Soybean meal samples were prepared by single-stage fermentation using Bacillus velezensis (Bv) (FSBMB), or Lactobacillus spp. (as commercial control) (FSBML). Additional SBM sample was prepared by two-stage fermentation using Bv and subsequently using Lactobacillus brevis ATCC 367 (Lb) (FSBMB+L). Enzyme activity, chemical composition, trichloroethanoic acid-nitrogen solubility index (TCA-NSI) and antioxidant activity were measured. Then, in an in vivo study, 320 Ross308 broilers were divided into four groups with ad libitum supply of feed and water. Four groups were fed either a corn-soybean meal diet (SBM), or one of fermented SBM diets (FSBMB+L, FSBMB, and FSBML). Growth, serum characteristics, microflora, and the mRNA expression of selected genes were measured. RESULTS: Compared to SBM, FSBMB+L contained lower galacto-oligosaccharide, allergic protein, and trypsin inhibitor, and higher TCA-NSI by about three times (p<0.05). Reducing power and 1,1-diphenyl-2-picrylhydrazyl free radical scavenging ability correlated positively with the TCA-NSI content in FSBM. Growth performances were not significantly different among four groups. In jejunum of 35-day-old broilers, partial replacement of SBM by FSBMB+L increased the activity of superoxide dismutase and catalase (CAT), and the FSBMB group had the highest catalase activity (p<0.05). Partial replacement of SBM by FSBM increased relative mRNA expressions of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and peptide transporter 1 (PepT1) (p<0.05); however, FSBMB+L increased CAT mRNA level to 5 times of the control (p<0.05). CONCLUSION: Using Bv- and Lb-processed SBM through two-stage fermentation to partially replace 6% of diets will improve the gut's antioxidant activity under commercial breeding in broilers.

Rapid detection of equine infectious anaemia virus nucleic acid by insulated isothermal RT-PCR assay to aid diagnosis under field conditions.

BACKGROUND: Control of equine infectious anaemia (EIA) currently depends on serological diagnosis of infected equids. However, recently infected equids may not produce detectable anti-EIAV antibodies up to 157 days post infection and so present a high transmission risk. Therefore, direct nucleic acid detection methods are urgently needed to improve EIAV surveillance and management programs in counties where the disease is endemic. OBJECTIVES: To evaluate a field-deployable, reverse transcription-insulated isothermal PCR (RT-iiPCR) assay targeting the conserved 5' untranslated region (5' UTR)/exon 1 of the tat gene of EIAV. STUDY DESIGN: The analytical and clinical performance of the newly developed EIAV RT-iiPCR was evaluated by comparison with a EIAV real-time RT-PCR (RT-qPCR) along with the AGID test. METHODS: Analytical sensitivity was determined using in vitro transcribed RNA containing the target area of the 5' UTR/tat gene and samples from two EIAV-positive horses. Specificity was verified using nine common equine viruses. Clinical performance was evaluated by comparison with EIAV RT-qPCR and AGID using samples derived from 196 inapparent EIAV carrier horses. RESULTS: EIAV RT-iiPCR did not react with other commonly encountered equine viruses and had equivalent sensitivity (95% detection limit of eight genome equivalents), with a concordance of 95.41% to conventional EIAV RT-qPCR. However, the RT-qPCR and RT-iiPCR had sensitivities of 43.75 and 50.00%, respectively, when compared to the AGID test. MAIN LIMITATIONS: Low viral loads commonly encountered in inapparent EIAV carriers may limit the diagnostic sensitivity of RT-PCR-based tests. CONCLUSIONS: Although EIAV RT-iiPCR is not sufficiently sensitive to replace the current AGID test, it can augment control efforts by identifying recently exposed or "serologically silent" equids, particularly as the latter often represent a significant transmission risk because of high viral loads. Furthermore, the relatively low cost and field-deployable design enable utilisation of EIAV RT-iiPCR even in remote regions.

Syncope caused by complete heart block and ventricular arrhythmia as early manifestation of systemic lupus erythematosus in a pregnant patient: a case report.

Systemic lupus erythematosus (SLE) can affect all heart structures including the conduction system, with either reversible or permanent derangement. However, only a few cases of adult SLE and complete atrioventricular (AV) block have been reported. We describe a young pregnant woman who initially presented with complete AV block on electrocardiography before the diagnosis of SLE. Syncope subsequently developed during the postpartum period due to frequent nonsustained polymorphic ventricular tachycardia, suggesting lupus myocarditis. The ventricular arrhythmia was successfully treated by intravenous corticosteroids, lidocaine and implantation of a permanent pacemaker. This may represent the first report of complete AV block with polymorphic ventricular tachycardia, which was identified before the other clinical features of SLE fully manifested. SLE should be considered if a patient presents with complete AV block without other clinical features. It may warn for early diagnosis and appropriate treatment of SLE including lupus-related heart disease.

Co-aggregation of major psychiatric disorders in individuals with first-degree relatives with schizophrenia: a nationwide population-based study.

A previous genetic study has suggested that schizophrenia, bipolar disorder, major depressive disorder, autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) share common disease-associated genes. However, whether individuals with first-degree relatives (FDRs) with schizophrenia have a higher risk of these major psychiatric disorders requires further investigation. This study used Taiwan's National Health Insurance Research Database and identified 151 650 patients with schizophrenia and 227 967 individuals with FDRs with schizophrenia. The relative risks (RRs) of schizophrenia and other major psychiatric disorders were assessed in individuals with FDRs with schizophrenia. The individuals with FDRs with schizophrenia exhibited higher RRs (95% confidence interval) of major psychiatric disorders, namely schizophrenia (4.76, 4.65-4.88), bipolar disorder (3.23, 3.12-3.35), major depressive disorder (2.05, 2.00-2.10), ASD (2.55, 2.35-2.77) and ADHD (1.31, 1.25-1.37) than were found in the total population. Several sensitivity analyses were conducted to confirm these results. A dose-dependent relationship was observed between the risks of major psychiatric disorders and the numbers of FDRs with schizophrenia. The increased risks of major psychiatric disorders were consistent in different family relationships, namely among parents, offspring, siblings and twins. Our study supports the familial dose-dependent co-aggregation of schizophrenia, bipolar disorder, major depressive disorder, ASD and ADHD, and our results may prompt governmental public health departments and psychiatrists to focus on the mental health of individuals with FDRs with schizophrenia.

Cognitive impairment and hippocampal atrophy in chronic kidney disease.

BACKGROUND: Cognition impairment is well known in patients with chronic kidney disease (CKD). The relationship between brain structure and cognitive performance in CKD patients is still under investigation. The study aimed to quantitatively assess the relationship between brain structure and cognitive performance in patients with CKD. METHODS: We recruited 39 patients with CKD and 39 age- and sex-matched control participants from a tertiary medical center. All participants underwent 3-T MRI scan neuropsychological assessments, and renal function tests. FreeSurfer software was used for imaging processing and analysis, including measurement of cortical thickness and gray matter (GM) and white matter volumes. RESULTS: Compared with control subjects (73.1±7.5 years old), patients with CKD (76.4±8.4 years old) had significantly lower scores on the Mini-Mental State Examination, and forward digit span test (P<.01). Patients with CKD had smaller cerebral GM volume, hippocampus, and decreased cortical thickness (P<.01) relative to the control group. Estimated glomerular filtration rate (eGFR) was correlated with cognitive performance, cortical thickness, GM volume, and hippocampal volume (P<.001). Linear regression analysis revealed that eGFR and GM volume were independently negatively associated with cognitive performance (P<.001), while eGFR and age were negatively associated with cortical thinning and GM volume after controlling for confounding factors. CONCLUSIONS: This study demonstrated that impaired kidney function is associated not only with poor cognitive performance, but also with small cerebral GM volume and reduced cortical thickness.

Increased serum interleukin-6, not minimal hepatic encephalopathy, predicts poor sleep quality in nonalcoholic cirrhotic patients.

BACKGROUND: Sleep-wake disturbances are common in patients with cirrhosis and have a considerable effect on health-related quality of life; however, the underlying mechanism behind the phenomenon is unclear. Cytokines are involved in the mediation of signalling pathways regulating fibrogenesis, leading to cirrhosis. In addition, increased cytokines could contribute to sleep disturbances. AIM: To determine the relationship between pro-inflammatory cytokines and sleep disturbance in cirrhotic patients. METHODS: Ninety-eight nonalcoholic cirrhotic patients without overt hepatic encephalopathy were enrolled in this cross-sectional study. The Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep quality. The Psychometric Hepatic Encephalopathy Score (PHES) was used to examine cognitive performance and define minimal hepatic encephalopathy (MHE). The Hospital Anxiety and Depression Scale (HADS) was used to evaluate the mood status of the patients. Pro-inflammatory cytokines that include interleukin 6 (IL-6) and tumour necrosis factor-α, as well as HBV-DNA or HCV-RNA levels were determined in patients. RESULTS: A total of 56 (57%) cirrhotic patients were identified as 'poor' sleepers (PSQI > 5). After multivariate analysis, IL-6 (P = 0.001) and HADS scores (P = 0.002) were found to be independent predictive factors of poor sleep quality. No significant relationships were observed between the sleep indices and the presence of MHE. HCV-RNA, but not HBV-DNA, viraemia was associated with sleep disturbance in cirrhotic patients. CONCLUSIONS: Sleep disturbance is found commonly in cirrhotic patients and a high serum IL-6 level is predictive of poor sleep quality. Minimal hepatic encephalopathy by itself may not contribute to sleep dysfunction in cirrhotic patients.

Risk of developing Parkinson's disease among patients with asthma: a nationwide longitudinal study.

BACKGROUND: A cross-sectional retrospective study suggested a link between allergic diseases and Parkinson's disease. However, the temporal association between asthma and Parkinson's disease remains unknown. METHODS: From the Taiwan National Health Insurance Research Database, 10 455 patients who were diagnosed with asthma between 1998 and 2008 and aged ≥45 years and 41 820 age- and sex-matched controls were selected for our study and observed until the end of 2011. Those who developed Parkinson's disease during the follow-up period were identified. We also examined the asthma severity, as indicated by the frequency of admission (times per year) for asthma exacerbation, and the risk of subsequent Parkinson's disease. RESULTS: Patients with asthma had an increased risk of developing Parkinson's disease (hazard ratio [HR]: 3.10, 95% confidence interval [CI]: 2.20-4.36) after we adjusted for demographic data, health system use, medical comorbidities, and medication use. Sensitivity tests yielded consistent findings after we excluded observations on the first year (HR: 2.90, 95% CI: 2.04-4.13) and first 3 years (HR: 2.46, 95% CI: 1.64-3.69). Patients with asthma who had more frequent admissions (times per year) during the follow-up period exhibited a greater risk of subsequent Parkinson's disease (>2: HR: 16.42, 95% CI: 5.88-45.91; 1-2: 12.69, 95% CI: 5.03-31.71; 0-1: HR: 2.92, 95% CI: 1.91-4.49). CONCLUSION: Patients with asthma had an elevated risk of developing Parkinson's disease later in life, and we observed a dose-dependent relationship between greater asthma severity and a higher risk of subsequent Parkinson's disease.

Differences in brain metabolism associated with agitation and depression in Alzheimer's disease.

OBJECTIVE: Agitation and depression are among the commonest behavioural and psychological symptoms exhibited by Alzheimer's disease patients. However, their pathophysiology remains unclear. We therefore investigated the relationship between the brain metabolism in the posterior cingulate gyrus and the dorsolateral prefrontal cortex, and agitation and depression in patients diagnosed with Alzheimer's disease. METHODS: We recruited 26 patients (14 women and 12 men) with a mean age of 75 years and probable Alzheimer's disease. All patients completed the Mini-Mental State Examination (MMSE), the Geriatric Depression Scale-Short Form (GDS) assessment, and the Cohen-Mansfield Agitation Inventory (CMAI) in order to evaluate cognition, depression, and agitation, respectively. All subjects underwent magnetic resonance imaging and (1)H-magnetic resonance spectroscopy of the brain. The ratios of N-acetylaspartate (NAA), choline (Cho), and myo-inositol (mI) to creatine (Cr) in the posterior cingulate gyrus and the dorsolateral prefrontal cortex were measured and compared with neuropsychological test results. RESULTS: The MMSE scores correlated positively with the NAA/Cr ratio in the left posterior cingulate gyrus (r = 0.56; p = 0.001). The CMAI scores correlated negatively with the NAA/Cr ratio in the left posterior cingulate gyrus (r = -0.46; p = 0.02). The GDS scores correlated positively with the Cho/Cr ratio in the left dorsolateral prefrontal cortex (r = 0.59; p = 0.01), and mI/Cr in both left (r = 0.47; p = 0.03) and right (r = 0.47; p = 0.03) cingulate gyri. CONCLUSIONS: Agitation and depression levels correlated with different neurochemical metabolites in specific brain areas. We conclude that various neuropsychiatric symptoms might have separate pathophysiologies.

The impact of number of drugs prescribed on the risk of potentially inappropriate medication among outpatient older adults with chronic diseases.

BACKGROUND: Older patients with chronic diseases often take multiple prescription drugs, increasing their risk of adverse health events. However, polypharmacy remains ill-defined. AIM: To investigate the impact of number of drugs prescribed on potentially inappropriate medication (PIM) and the associated risk factors in older outpatients with chronic diseases. DESIGN: Retrospective cross-sectional study. METHODS: We retrospectively assessed 780 older patients (mean, 75.5 ± 7.1 years) with long-term (≥ 28 days) prescriptions for chronic diseases at the geriatric clinics of a university hospital from January to June 2012 using the Screening Tool of Older Person's potentially inappropriate Prescriptions (STOPP). Clinical information for each patient was analyzed. Logistic regression and receiver operating characteristic curve (ROC) analyses were performed; number needed to harm (NNH) was also estimated. RESULTS: According to STOPP criteria, 302 patients (39%) had at least one PIM. Multivariate analysis revealed that PIM risk was associated with the number of medications prescribed (P < 0.001) and the presence of cardiovascular (P < 0.001) or gastrointestinal disease (P = 0.003). The estimated area under the ROC for the number of medications needed to predict PIM risk was 0.680 (P < 0.001) with the optimal cut-off value of five medications. After adjusting covariates, patients prescribed ≥ 5 drugs [adjusted odds ratio (OR) = 5.4; adjusted NNH = 4.25; P < 0.001] and those prescribed 4 drugs (adjusted OR = 3.5; adjusted NNH = 6.88; P = 0.003) had significantly higher PIM risk than those prescribed ≤ 2 drugs. CONCLUSIONS: The number of prescribed medications can be an index of PIM risk in older patients with chronic diseases. Clinicians should suspect high PIM risk in older outpatients with ≥ 5 prescriptions.

First Report of Cowpea mild mottle virus in Cowpea and French Bean in Taiwan.

In 2009, more than 50% of vine type French beans were found bearing severe viral symptoms in a vegetable garden in Nantou County, Taiwan. Infected plants were stunted and exhibited pronounced mottling symptoms on their leaves. The symptomatic plants were mechanically inoculated on Chenopodium quinoa and local lesions developed 7 to 10 days after inoculation. The virus source established by back isolation the single lesion from C. quinoa on French beans developed symptoms similar to those found in the field. Host range test showed that this isolate could only infect leguminous plants, including soybean, mung bean, pea, peanut, asparagus bean, cowpea, adzuki bean, and lima bean, but not cucurbitaceous and solanaceous plants. Since only Cucumber mosaic virus (CMV) has been reported in Taiwan to induce similar symptoms in French beans, we tested both the field collected and inoculated French beans by CMV antiserum in ELISA but obtained a negative result. Due to subsequent electron microscopy studies that found potyvirus and carlavirus like particles in the leaf dips of infected French beans, we conducted reverse transcription (RT)-PCR using generic degenerate primers for potyviruses (Hrp5/Pot1 (2) and PotZ/Pot1 (3)) and carlaviruses (Decarla-u2 (5'-TGCACTGARTCMGAYTATGARGCYTT-3' and Decarla-d1 (5'-GCACATRTCRTCVCCDGCAAA-3') previously designed in our lab. No amplification was found from the potyvirus primers, while the carlavirus one gave an expected amplicon of 285 bp, which was found sharing 81% nucleotide sequence identity with the replicase gene of Cowpea mild mottle virus (CpMMV) (GenBank Accession No. FJ560903). A primer pair (CpMMV-CPu: 5'-TTTACTCTTAggTWATggAgTC-3' and CpMMV-CPd: 5'-CCTATTAAAACACACAAHTCAAA-3') was thus designed to amplify the complete coat protein (CP) gene based on the reported CP sequences and obtained an expected 867-bp product from our French bean isolate. This 867-bp sequence (JX020701) was confirmed to have 97.6% amino acid sequence identities with the CP gene of a Puerto Rican CpMMV isolate (GU191840). In a separate survey, another isolate from asparagus bean (CpMMV-V) causing mild mottling symptom was obtained. Analyses of the CP gene of CpMMV-V (JX070669) confirmed that it shared 88.8% and 97.8% of nucleotide and amino acid sequence identities with the French bean isolate, respectively. Different from most carlaviruses with aphid transmissibility, CpMMV has been shown to be transmitted non-persistently by whiteflies (1). Both CpMMV isolates from Taiwan were confirmed to be transmitted by silver leaf whiteflies (Bemicia argentifolii Bellows and Perring). This is the first record of whitefly transmissible legume virus in Taiwan. Since whitefly has been a problem in agriculture worldwide, CpMMV can be a new emerging threat for Taiwan's legume crop production. References: (1) M. Iwaki et al. Plant Dis. 66:365, 1982. (2) S. S. Pappu et al. J. Virol. Methods 41:9, 1993. (3) F. M. Zerbini et al. Phytopathology 85:746.

Understanding nanoparticle self-assembly for a strong improvement in functionality in thin film nanocomposites.

The striking influence of the growth kinetics and substrate enhanced surface mobility on the control of the self-assembly of rare earth tantalate particles (1.5 mol% of nanoparticles in YBa(2)Cu(3)O(7) thin films) is demonstrated. Strongly enhanced flux pinning, control of the anisotropy property and superior critical current densities were achieved. Owing to the unique ability to probe nanoparticle self-assembly through determination of the nature and extent of the anisotropy of the superconducting properties, this system serves as the perfect model system for understanding how to tune and control functional nanocomposite nanostructures for a wide range of multifunctional applications.

Survey and risk assessment of trace elements in foods from Taiwan containing red mould rice (Monascus) by ICP-MS.

The concentrations of seven trace elements (As, Cd, Cr, Pb, Se, Cu and Zn) in 93 red mould rice (Monascus) food samples in Taipei, Taiwan, were determined by inductively coupled plasma-mass spectrometry (ICP-MS) after wet digestion. The results, calculated in mg kg(-1) (wet weight) for each sample, revealed the general scenario of food safety in Taiwan: As (0.005-12.04), Cd (<0.0005-2.22), Cr (0.014-6.95), Cu (0.012-8.70), Pb (0.001-0.64), Se (<0.001-1.29) and Zn (0.020-67.02). Three food samples were identified with As concentrations higher than regulatory limits: a dietary supplement sample and a seaweed sample with As concentrations that exceeded the limit of Taiwan's health food standard of 2 mg kg(-1), and a canned eel sample with an As concentration that exceeded the limit of Canada's fish standard of 3.5 mg kg(-1). This study suggests that the estimated intakes of these seven trace elements from the consumption of foods containing Monascus pose little risk, as the trace element contents in the majority of samples were lower than the permissible/tolerable intakes per week according to the guidelines recommended by the Food and Agricultural Organization/World Health Organization (FAO/WHO). Moreover, their concentrations in foods containing Monascus differ widely for different food varieties, suggesting that external contaminants and raw materials are the main sources of trace elements. This study shows that ICP-MS is a simple method proposed for the determination of As, Cd, Cr, Pb, Se, Cu, and Zn in foods containing Monascus.

Survey of total mercury in foods from Taiwan containing red mould rice (Monascus) using a direct mercury analyser (DMA).

Total mercury concentrations in 69 red mould rice (Monascus) food samples purchased in Taipei, Taiwan, were determined using the direct mercury analyser (DMA) method. The highest mean levels of total mercury in these samples were observed in samples of canned roast eel (20 µg kg(-1)), soy fibrous product (14 µg kg(-1)), red mould rice (8.5 µg kg(-1)), cereal (7.6 µg kg(-1)), dried pork fibre (7.5 µg kg(-1)), and dietary supplement (7.2 µg kg(-1)). All samples analysed had mercury levels below the limit of 50 µg kg(-1) for food standards in rice, edible oil, and fat of Taiwan. The mercury concentration in the Monascus foods differed widely between different food varieties, suggesting that external contamination and raw materials are the main sources of mercury. This study shows that DMA is a simple method proposed for the determination of total mercury in foods containing Monascus. The method requires no sample pre-treatment, and it minimizes potential sources of contamination. The data (42±2 µg kg(-1)) obtained from five analyses of a standard reference material (apple leaves, NIST-1515) showed good agreement with the certified reference value (44±4 µg kg(-1)) provided by the US National Institute of Standards and Technology (NIST). The precision based on the analysis of standard reference material was 4.1%; the average recovery was 95%.

Design and implementation of a system with a multielement thermopile for monitoring temperature of a plane.

In this paper, we report the design of a system equipped with a multielement thermopile for measuring the temperature of a given plane. We evaluate the performance of our measurement system, which comprises a microcontroller, an analog-to-digital converter, a liquid crystal display (LCD), light-emitting diodes (LEDs), a buzzer, laser pointers, and a rotary encoder. We use different types of display modes such as an LCD for displaying the measured temperature, LEDs which colors indicate the temperature range, and an RS-232 or a wireless interface that transmits the temperature values to be displayed as different colors on a PC screen. The buzzer/alarm in the system is activated when the threshold temperature is reached. The system is inexpensive, portable, and can be used for two-dimensional temperature measurements; further, its emissivity can be easily adjusted. The effective detection range of this system is from -20 to 115 degrees C, and the field of view is 41 degrees x32 degrees ; the measurement error is confined to +/-1 degrees C. The experimental results demonstrate the effectiveness of the system in monitoring the temperature of a remote plane. Hence, it is possible to identify a hot spot that occurred in the electrical heating equipment or a smoldering source hidden in upholstery.

Effects of cavotricuspid isthmus ablation on atrioventricular node electrophysiology in patients with typical atrial flutter.

BACKGROUND: The atrial musculature in the cavotricuspid isthmus is a part of posterior inputs to the AV node. In patients with typical atrial flutter, effects of radiofrequency ablation of this isthmus on AV node conduction are still unknown. METHODS AND RESULTS: This study included 16 patients with clinically documented typical atrial flutter. Group 1 had 8 patients without and group 2 had 8 patients with dual AV nodal pathway physiology. Electrical pacing from the interatrial septum and low right atrium was performed to evaluate antegrade AV node function before and after ablation of the cavotricuspid isthmus. In group 1, the AV node conduction properties were similar before and after ablation. In group 2, the AV node Wenckebach cycle length and maximal AH interval during low right atrium (356+/-58 versus 399+/-49 ms, P=0.008; 303+/-57 versus 376+/-50 ms, P=0.008) and interatrial septum (365+/-62 versus 393+/-59 ms, P=0.008; 324+/-52 versus 390+/-60 ms, P=0.008) pacing were significantly longer after ablation. Elimination of the slow pathway after ablation was noted in 2 patients, including 1 with AV nodal reentrant echo beats. CONCLUSIONS: Radiofrequency ablation of the cavotricuspid isthmus was effective in eliminating typical atrial flutter without injury of antegrade fast AV node conduction. The atrial musculature in the cavotricuspid isthmus significantly contributed to the slow AV node conduction.

Acquired pulmonary vein stenosis after radiofrequency catheter ablation of paroxysmal atrial fibrillation.

INTRODUCTION: Elimination of the initiating focus within the pulmonary vein (PV) using radiofrequency (RF) catheter ablation is a new treatment modality for treatment of drug-refractory atrial fibrillation. However, information on the long-term safety of RF ablation within the PV is limited. METHODS AND RESULTS: In 102 patients with drug-refractory atrial fibrillation and at least one initiating focus from the PV, series transesophageal echocardiography was performed to monitor the effect of RF ablation on the PV. There were 66 foci in the right upper PV and 65 foci in the left upper PV. Within 3 days of ablation, 26 of the ablated right upper PVs (39%) had increased peak Doppler flow velocity (mean 130+/-28 cm/sec, range 106 to 220), and 15 of the ablated left upper PVs (23%) had increased peak Doppler flow velocity (mean 140+/-39 cm/sec, range 105 to 219). Seven patients had increased peak Doppler flow velocity in both upper PVs. No factor (including age, sex, site of ablation, number of RF pulses, pulse duration, and temperature) could predict PV stenosis after RF ablation. Three patients with stenosis of both upper PVs experienced mild dyspnea on exertion, but only one had mild increase of pulmonary pressure. There was no significant change of peak and mean flow velocity and of PV diameter in sequential follow-up studies up to 16 (209+/-94 days) months. CONCLUSION: Focal PV stenosis is observed frequently after RF catheter ablation applied within the vein, but usually is without clinical significance. However, ablation within multiple PVs might cause pulmonary hypertension and should be considered a limiting factor in this procedure.

Effectiveness of a positive expiratory pressure device in conjunction with beta2-agonist nebulization therapy for bronchial asthma.

Patients with asthma often show increased airway hyperreactivity and mucus hypersecretion. Although beta2-agonist therapy is one of the most common and effective ways used to relieve airway obstruction, the use of a positive expiratory pressure device (PEPD) is also effective in mucus clearance. However, no previously reported study has examined the effectiveness of these two therapies used in combination. This study assessed the effectiveness of a PEPD on beta2-agonist nebulization therapy by measuring the pulmonary function before and after nebulization therapy in 54 asthmatic patients. The results show that the use of PEPD after beta2-agonist nebulization therapy improved pulmonary function compared with the use of beta2-agonist nebulization therapy alone, as shown by the increases in forced midexpiratory flow and forced vital capacity (FVC). Patients with forced expiratory volume in 1 sec (FEV1) below 85% FVC obtained a significant improvement in FEV1 and FVC after using PEPD. When PEPD was used before beta2-agonist nebulization therapy, there were no obvious direct bronchodilative effects. The use of PEPD after beta2-agonist therapy, however, significantly enhanced the bronchodilative effect of beta2-agonist therapy in patients with an FEV1 below 85% FVC. The additional effect of PEPD use in improving pulmonary function after beta2-agonist nebulization therapy might be a result of an enhancement in mucus clearance.

Effect of nitric oxide on strophanthidin-induced ventricular tachycardia.

Nitric oxide (NO) has been demonstrated to have several effects on the heart. Through the stimulation of guanylate cyclase, NO increases cyclic GMP and decreases intracellular calcium. The purpose of this study was to evaluate the effects of NO on ventricular arrhythmia induced by strophanthidin in guinea pigs and dogs. In experiment 1, after strophanthidin-induced ventricular tachycardia, guinea pigs received different doses of L-arginine (0, 25, 50, 100, 200, and 400 mg/kg; n = 10 for each dose), 200 mg/kg L-arginine combined with 100 mg/kg N(G)-nitro-L-arginine methylester (L-NAME, n = 10), or 200 mg/kg D-arginine (n = 10). In experiment 2, after strophanthidin-induced ventricular tachycardia, dogs (n = 7) received 200 mg/kg L-arginine. By 12-lead ECG, monophasic action potentials in left and right ventricles were recorded throughout the study. In experiment 1, guinea pigs which received 200 mg/kg or 400 mg/kg L-arginine had greater incidences of ventricular tachycardia termination (60 and 80%, respectively) than those which received 0, 25, 50, and 100 mg/kg L-arginine (0, 0, 20, and 30%, respectively), those which received L-arginine with L-NAME (0%), and those which received D-arginine (0%). In experiment 2, 5 (71%) of the dogs had successful termination of ventricular tachycardia. These findings suggest that L-arginine was effective in treating strophanthidin-induced ventricular tachycardia in vivo and that the underlying mechanism is through a NO pathway.