Condition optimization of iron-air fuel cell to treat phosphate-containing wastewater regarding sustainable development.

Increasing use of phosphorus products and excessive exploitation of phosphorus resources become two major problems in perspective of phosphorus sustainable development. Phosphorus recovery is the shortcut to solve this dilemma. Combining electrochemistry, an iron-air fuel cell was adopted to recover phosphate and electricity from phosphate-containing wastewater in our previous studies. The present study focused on investigating the effects of catholyte/anolyte conductivity, external resistance, and anolyte pH on the performance of iron-air fuel cell, and obtaining the optimized conditions. Furthermore, the electrochemical methods of phosphate recovery were compared and assessed, and it is concluded that iron-air fuel cell has great potential for energy recovery. The phosphate removal efficiencies and vivianite yield roughly positively correlated with the catholyte conductivity and the anolyte pH, but negatively correlated with the external resistance and the anolyte conductivity. The electricity generation roughly positively correlated with the catholyte conductivity and anolyte conductivity, but showed limitations in the test range of anolyte pH and external resistance. To pursue high phosphate removal efficiencies and vivianite yield, the catholyte conductivity, external resistance, anolyte pH and anolyte conductivity were suggested to be 35 g-NaCl/L, 10 Ω, 8 and 0 g-NaCl/L. While if electricity generation was the primary goal, these parameters should be 35 g-NaCl/L, 220 Ω, 5 and 70 g-NaCl/L. The optimized conditions will help to improve the phosphate removal efficiency, vivianite yield and electricity generation, and to promote the development of iron-air fuel cell technology.

Corncob biocarriers with available carbon release for Chlamydopodium sp. microalgae towards enhanced nitrogen removal from low C/N rare earth element tailings (REEs) wastewater.

Low nitrogen (N) removal efficiency limits the potential of microalgae technology for the treatment of high nitrogen and low carbon rare earth tailings (REEs) wastewater. In this study, waste corncob was utilized as a biocarrier immobilizing Chlamydopodium sp. microalgae to realize high-efficient treatment of the REEs wastewater. In only 2.5 d, corncob-immobilized microalgae allowed the residual concentrations of N lower than the emission standards, and ammonia nitrogen (NH4+-N) removal rate is 83.3 mg L-1·d-1, total inorganic nitrogen (TIN) removal rate is 86.7 mg L-1·d-1, which was 18.5 times that of the previously-reported microalgae (4.68 mg L-1·d-1). Compared with other microalgae immobilization carriers, corncob possesses the ability to release available carbon sources for microalgae. Composition analysis and sugar verification experiments showed that the main content of TOC released by corncob was monosaccharide, and in a certain range, the removal rate of N was positively correlated with the TOC concentration. The utilization of biomass wastes with dual functions as biological carriers has great potential to improve the performance of microalgae, and is conducive to the development of engineering applications.

The impact of antenatal massage practice on intrapartum massage application and their associations with the use of analgesics during labour : Sub-analysis of a randomised control trial.

BACKGROUND: Massage during labour is one form of intrapartum non-pharmacological pain relief but it is not known whether the frequency of practicing these massage techniques among couples during the antenatal period could enhance the effectiveness of intrapartum massage. This study was to evaluate the association between compliance of antenatal massage practice with intrapartum application and their impact on the use of analgesics during labour. METHODS: This was a sub-analysis of a childbirth massage programme which was carried out in two public hospitals with total births of around 8000 per year. Data from women who were randomized to the massage group were further analysed. After attending the pre-birth training class on massage at 36 weeks gestation, couples would be encouraged to practice at home. Their compliance with massage at home was classified as good if they had practiced for at least 15 minutes for three or more days in a week, or as poor if the three-day threshold had not been reached. Application of intrapartum massage was quantified by the duration of practice divided by the total duration of the first stage of labour. Women's application of intrapartum massage were then divided into above and below median levels according to percentage of practice. Logistic regression was used to assess the use of epidural analgesia or pethidine, adjusted for duration of labour and gestational age when attending the massage class. RESULTS: Among the 212 women included, 103 women (48.6%) achieved good home massage compliance. No significant difference in the maternal characteristics or birth outcomes was observed between the good and poor compliance groups. The intrapartum massage application (median 21.1%) was inversely associated with duration of first stage of labour and positively associated with better home massage practice compliance (p = 0.04). Lower use of pethidine or epidural analgesia (OR 0.33 95% CI 0.12, 0.90) was associated with above median intrapartum massage application but not antenatal massage compliance, adjusted for duration of first stage of labour. CONCLUSIONS: More frequent practice of massage techniques among couples during antenatal period could enhance the intrapartum massage application, which may reduce the use of pethidine and epidural analgesia. TRIAL REGISTRATION: (CCRBCTR) Unique Trial Number CUHK_ CCRB00525 .

[Phosphorus Fractions and Quantitative Identification of Pollution Sources in Nanhai Wetland, Baotou].

In this study, total phosphorus (TP) and the phosphorus (P) fractions in the water and surface sediments of the Baotou Nanhai wetland in China were determined using molybdenum blue/ascorbic acid spectrophotometry and continuous extraction methods. An APCS-MLR receptor model was combined with correlation analysis (CA) and principal component analysis (PCA) to identify and quantify the pollution sources. The results showed ① differences in the pollution level of phosphorus between the surface sediments and water. The contribution of dissolved inorganic phosphorus (DIP) to TP in the water (WTP) was the lowest, while the contribution of calcium-bound phosphorus (HCl-P) to TP in the surface sediments (STP) was the largest in the study area. The surface sediments of the Nanhai Lake (L area) and the wetland plant area (P area) exhibited high bioavailability and the potential for releasing phosphorus into the water, which could result in eutrophication and is therefore of concern. ② The APCS-MLR receptor model indicated that the main pollution sources of phosphorus were industrial wastewater and domestic sewage (29.07%), and pesticides and fertilizers (29.00%). In addition, the degradation of animal and plant residues (18.49%) also contributed to pollution in the study area.

Hepatoprotective effect of total flavonoids of Mallotus apelta (Lour.) Muell.Arg. leaf against carbon tetrachloride-induced liver fibrosis in rats via modulation of TGF-ß1/Smad and NF-κB signaling pathways.

ETHNOPHARMACOLOGICAL RELEVANCE: The Mallotus apelta (Lour.) Muell.Arg. is a well-known traditional Chinese medicine (TCM) used for anti-inflammatory, hemostasis and chronic hepatitis. AIM: The purpose of this study was to explore the antifibrotic effect of total flavonoids of Mallotus apelta leaf (TFM) and its potential mechanism. METHODS: Hepatic fibrosis was induced by carbon tetrachloride (CCl4) in rats. The CCl4-induced rats received intragastric administration of colchicine (0.2 mg/kg per day), TFM (25, 50, 100 mg/kg per day) and the equal vehicle was given to normal rats. Pathological evaluation in hepatic tissue were examined by hematoxylin and eosin (HE) staining. And the levels of serum biochemical parameters were detected by automatic biochemical analysis. Meanwhile, the collagen deposition in liver was observed by staining with Masson's trichrome. Collagenic parameters and inflammatory factors were measured by enzyme-linked immunosorbent assay (ELISA) kits. Additionally, corresponding assay kit was used to estimate the antioxidant enzyme and lipid peroxidation. In order to explore the potential mechanism of anti-fibrotic effects in TFM, the expressions of liver fibrosis related gene and protein were analyzed by real-time quantitative reverse transcription polymerase chain reaction (RT-PCR) and Western blot. RESULTS: The CCl4-induced hepatic fibrosis were inhibited dose-dependently in rats by TFM. The results showed that the key hallmarks of liver injury including aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), albumin (ALB) and total protein (TP) in the serum were reversed in CCl4-induced hepatic fibrosis rats which were treated by TFM. Furthermore, TFM significantly alleviates collagen accumulation and reduces the contents of hydroxyproline (Hyp), Type III precollagen (PC-III), collagen I (Col I), hyaluronic acid (HA) and laminin (LN). RT-PCR and Western blot results showed that TFM markedly inhibits liver fibrosis hallmark factor α-smooth muscle actin (α-SMA) expressions in CCl4-induced hepatic fibrosis rats. Moreover, TFM alleviated the oxidative stress and lipid peroxidation in rats induced by CCl4. TFM also attenuated the pro-inflammatory cytokines including interleukin-1ß (IL-1ß), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) via inhibiting nuclear factor-κB (NF-κB) activation. Meanwhile, transforming growth factor-ß1 (TGF-ß1)/Smad signaling pathway was inhibited by TFM treatment. CONCLUSIONS: TFM can alleviate CCl4-induced hepatic fibrosis in rats, which potential mechanism may be due to its ability of reducing ECM accumulation, improving antioxidant and regulating TGF-ß1/Smad signaling pathways and NF-κB-dependent inflammatory response.

Clinical Characteristics of Patients with Drug-induced Liver Injury.

BACKGROUND: Drug is an important cause of liver injury and accounts for up to 40% of instances of fulminant hepatic failure. Drug-induced liver injury (DILI) is increasing while the diagnosis becomes more difficult. Though many drugs may cause DILI, Chinese herbal medicines have recently emerged as a major cause due to their extensive use in China. We aimed to provide drug safety information to patients and health carers by analyzing the clinical and pathological characteristics of the DILI and the associated drug types. METHODS: A retrospective analysis was conducted in 287 patients diagnosed with DILI enrolled in our hospital from January 2011 to December 2015. The categories of causative drugs, clinical and pathological characteristics were reviewed. RESULTS: Western medicines ranked as the top cause of DILI, accounting for 163 out of the 287 DILI patients (56.79%) in our study. Among the Western medicine, antituberculosis drugs were the highest cause (18.47%, 53 patients) of DILI.   Antibiotics (18 patients, 6.27%) and antithyroid (18 patients, 6.27%) drugs also ranked among the major causes of DILI. Chinese herbal medicines are another major cause of DILI, accounting for 36.59% of cases (105 patients). Most of the causative Chinese herbal medicines were those used to treat osteopathy, arthropathy, dermatosis, gastropathy, leukotrichia, alopecia, and gynecologic diseases. Hepatocellular hepatitis was prevalent in DILI, regardless of Chinese herbal medicine or Western medicine-induced DILI. CONCLUSIONS: Risks and the rational use of medicines should be made clear to reduce the occurrence of DILI. For patients with liver injury of unknown origin, liver tissue pathological examination is recommended for further diagnosis.

Impact of fetal and childhood mercury exposure on immune status in children.

BACKGROUND: Mercury exposure have been shown to affect immune status in animals as reflected by cytokine expression. It is unclear whether low levels of exposure during fetal and/or childhood periods could impact on immune status in humans. OBJECTIVES: To test the hypothesis that fetal and childhood mercury exposure is associated with childhood cytokine profiles and to investigate whether childhood selenium levels interact with any of the associations found. METHODS: Children were recruited from a previously established birth cohort between the ages of 6-9 years for assessment and measurement of blood mercury, selenium and cytokine profile (interleukin (IL)-4, IL-6, IL-8, IL-10, IL-13 and TNF-alpha). Multivariable linear regression models were used to assess the adjusted association of cord blood mercury concentration and current mercury concentrations with levels of the cytokine levels. We tested whether the association with current mercury level varied by current selenium level and cord blood mercury level. RESULTS: IL-10 was negatively associated with current blood mercury concentration. The effect was greatest in cases with low cord blood mercury and low current selenium concentrations. None of the other cytokine levels were associated with either cord blood or current blood mercury concentrations, except that cord blood mercury was negatively associated with IL-6. CONCLUSIONS: Childhood mercury exposure was negatively associated with childhood IL-10 levels. It is postulated that while selenium is protective, low levels of fetal mercury exposure may increase the degree of this negative association during childhood. Further studies into the clinical significance of these findings are required.

Use of second-line therapies for management of massive primary postpartum hemorrhage.

OBJECTIVE: To determine rates of use and success of second-line therapies for massive primary postpartum hemorrhage (PPH). METHODS: A retrospective cohort study was conducted among 91 women who gave birth at Kwong Wah Hospital, Hong Kong, between January 1, 2006, and December 31, 2011. Inclusion criteria were gestational age of at least 24 weeks and massive PPH (defined as blood loss ≥1500 mL within 24 hours after birth). Second-line therapies assessed were uterine compression sutures, uterine artery embolization, and balloon tamponade after failure of uterine massage and uterotonic agents to stop bleeding. RESULTS: The rate of massive PPH was 2.65 per 1000 births. Second-line therapies were used among 42 women with PPH, equivalent to a rate of 1.23 per 1000 births. Only 21.4% of the women who received second-line therapies required rescue hysterectomy. A rising trend was observed for the use of second-line therapies, whereas the incidence of rescue hysterectomy and estimated blood loss were found to concomitantly decrease. CONCLUSION: Increasing use of second-line therapies among women with massive PPH was associated with a decreasing trend for rescue hysterectomy. Obstetricians should, therefore, consider all available interventions to stop PPH, including early use of second-line options.

Capsaicin ameliorates stress-induced Alzheimer's disease-like pathological and cognitive impairments in rats.

Hyperphosphorylated tau aggregated into neurofibrillary tangles is a hallmark lesion of Alzheimer's disease (AD) and is linked to synaptic and cognitive impairments. In animal models, cold water stress (CWS) can cause cognitive disorder and tau hyperphosphorylation. Capsaicin (CAP), a specific TRPV1 agonist, is neuroprotective against stress-induced impairment, but the detailed mechanisms are still elusive. Here, we investigated whether CAP mitigates CWS-induced cognitive and AD-like pathological alterations in rats. The animals were administered CAP (10 mg/kg in 0.2 ml, 0.1% ethanol) or a control (0.2 ml normal saline, 0.1% ethanol) by intragastric infusion 1 h before CWS treatment. Our results showed that CAP significantly attenuated CWS-induced spatial memory impairment and suppression of PP-DG long-term potentiation; CAP abolished CWS-induced dendritic regression and enhanced several memory-associated proteins decreased by CWS, such as synapsin I and PSD93; CAP also prevented CWS-induced tau hyperphosphorylation by abolishing inhibition of protein phosphatase 2A. Taken together, this study demonstrated that activation of TRPV1 can mitigate CWS-induced AD-like neuropathological alterations and cognitive impairment and may be a promising target for therapeutic intervention in AD.

Flavonoid Myricetin Modulates GABA(A) Receptor Activity through Activation of Ca(2+) Channels and CaMK-II Pathway.

The flavonoid myricetin is found in several sedative herbs, for example, the St. John's Wort, but its influence on sedation and its possible mechanism of action are unknown. Using patch-clamp technique on a brain slice preparation, the present study found that myricetin promoted GABAergic activity in the neurons of hypothalamic paraventricular nucleus (PVN) by increasing the decay time and frequency of the inhibitory currents mediated by GABA(A) receptor. This effect of myricetin was not blocked by the GABA(A) receptor benzodiazepine- (BZ-) binding site antagonist flumazenil, but by KN-62, a specific inhibitor of the Ca(2+)/calmodulin-stimulated protein kinase II (CaMK-II). Patch clamp and live Ca(2+) imaging studies found that myricetin could increase Ca(2+) current and intracellular Ca(2+) concentration, respectively, via T- and L-type Ca(2+) channels in rat PVN neurons and hypothalamic primary culture neurons. Immunofluorescence staining showed increased phosphorylation of CaMK-II after myricetin incubation in primary culture of rat hypothalamic neurons, and the myricetin-induced CaMK-II phosphorylation was further confirmed by Western blotting in PC-12 cells. The present results suggest that myricetin enhances GABA(A) receptor activity via calcium channel/CaMK-II dependent mechanism, which is distinctively different from that of most existing BZ-binding site agonists of GABA(A) receptor.

[Clinical research on treatment of migraine with pine needle moxibustion].

OBJECTIVE: To observe the clinical effect and mechanism of migraine treated with pine needle moxibustion. METHODS: Forty-three patients were randomly divided into 2 groups of pine needle moxibustion group (group A, 21 cases) and medicated thread moxibustion of Zhuang medicine group (group B, 22 cases). Same acu-points were selected as the main points for both groups, namely Fengchi (GB 20), Baihui (GV 20), Taiyang (EX-HN 5), Shuaigu (GB 8), Cuanzhu (BL 2), Sizhukong (TE 23), Yanglingquan (GB 34), Waiguan (TE 5) and Ashi points. Pine needle moxibustion was applied for the group A. Processed lighted pine needles were banded together with one even head to do moxibustion on acupoints or pain points. While, lighted medicated thread was adopted for the group B to do moxibustion. Therapeutic effects, the content of high-sensitivity C-reactive protein (hs-CRP), Mg2+ in the serum and the degree of pain of the two groups were compared. RESULTS: (1) In the group A, the complete remission rate was 47.6% (10/21) and the effective rate was 90.5% (19/21). In the group B, the complete remission rate was 13.6% (3/22) and the effective rate was 50.0% (11/22). The two rates in the group A were superior to those in the group B (both P < 0.01); (2) In the group A, the content of hs-CRP was decreased from (4.29 +/- 0.98) mg/L to (2.11 +/- 0.87) mg/L, and Mg2+ was increased from (0.67 +/- 0.28) mmol/L to (1.07 +/- 0.16) mmol/L. In the group B, the contents of the above mentioned indices were respectively decreased from (4.30 +/- 1.07) mg/L to (3.38 +/- 1.15) mg/L and increased from (0.68 +/- 0.21) mmol/L to (0.88 +/- 0.25) mmol/L. There were significant differences between the two groups after treatment (both P < 0.05). (3) The degree of pain in the group A after treatment was much lower than that in the group B (P < 0.05). CONCLUSION: The clinical effect of migraine treated with pine needle moxibustion is better than that with the medicated thread moxibustion of Zhuang medicine. And it has obvious regulation effect on the levels of hs-CRP and Mg2+ in the serum of patients.

Bak Foong Pills induce an analgesic effect by inhibiting nociception via the somatostatin pathway in mice.

Dysmenorrhoea, defined as cramping pain in the lower abdomen occurring before or during menstruation, affects, to varying degrees, up to 90% of women of child-bearing age. We investigated whether BFP (Bak Foong Pills), a traditional Chinese medicine treatment for dysmenorrhoea, possesses analgesic properties. Results showed that BFP was able to significantly reduce pain responses following subchronic treatment for 3 days, but not following acute (1 h) treatment in response to acetic acid-induced writhing in C57/B6 mice. The analgesic effect was not due to inhibition of COX (cyclo-oxygenase) activity, evidenced by the lack of inhibition of prostacyclin and PGE2 (prostaglandin E2) production. Molecular analysis revealed that BFP treatment modulated the expression of a number of genes in the spinal cord of mice subjected to acetic acid writhing. RT-PCR (reverse transcription-PCR) analysis of spinal cord samples showed that both sst4 (somatostatin receptor 4) and sst2 receptor mRNA, but not µOR (µ-opiate receptor) and NK1 (neurokinin-1) receptor mRNA, were down-regulated following BFP treatment, thus implicating somatostatin involvement in BFP-induced analgesia. Administration of c-som (cyclo-somatostatin), a somatostatin antagonist, prior to acetic acid-induced writhing inhibited the analgesic effect. Thus subchronic treatment with BFP has anti-nociceptive qualities mediated via the somatostatin pathway.

Bak Foong protects dopaminergic neurons against MPTP-induced neurotoxicity by its anti-apoptotic activity.

Bak Foong pill (BFP) is a well-known traditional Chinese medicine used for treatment of various gynaecological disorders. In addition, it exerts beneficial effects on other functional systems including the central nervous system. In the present study, we have investigated the possible neuroprotective action of BFP upon the nigrostriatal dopaminergic system by examining its effect on the expression patterns of tyrosine hydroxylase (TH) and dopamine transporter (DAT) in the 1-methyl-4-phenyl-1,2,3,6-tetrahyrdropyridine (MPTP)-induced Parkinson's disease (PD) mouse model. MPTP significantly decreased TH and DAT mRNA levels in the striatum and midbrain of both female and male C57BL/6 mice. However, with BFP pre-treatment mice showed a reduced neurotoxicity, with TH and DAT mRNA levels either not affected by MPTP or affected to a lesser extent in the midbrain and striatum when compared to vehicle treated animals. Possible anti-apoptotic activity of BFP was further studied in a dopamine-secreting neuroendocrine cell line, PC12. In this assay, MPTP elevated the expression of a pro-apoptotic gene, Bax, while this expression was reduced by BFP pre-treatment. Flow cytometry results also revealed that the effect of MPTP-induced apoptosis in PC12 cell lines was significantly reduced by BFP. The present results suggest that BFP is able to protect dopaminergic neurons from neurotoxin-induced neuronal injury with anti-apoptotic activity being one of the possible mechanisms.

Polyacetylenes function as anti-angiogenic agents.

PURPOSE: To investigate the antiangiogenic effects of plant extracts and polyacetylenes isolated from Bidens pilosa Linn., which is a popular nutraceutical herbal tea and folk medicine in anti-inflammatory, antitumor, and other medications worldwide. METHODS: Anti-cell proliferation, anti-tube formation, and cell migration assays were used for the valuation of bioactivities of target plant extracts and phytocompounds against angiogenesis. Bioactivity-guided fractionation, HPLC, and various spectral analyses were used to identify active fraction and phytocompounds for anti-angiogenesis. RESULTS: We show that an ethyl acetate (EA) fraction of B. pilosa exhibited significant anti-cell proliferation and anti-tube formation activities against human umbilical vein endothelium cells (HUVEC). Bioassay-guided fractionation led to isolation of one new and one known polyacetylenes, 1,2-dihydroxytrideca-5,7,9,11-tetrayne (1) and 1,3-dihydroxy-6(E)- tetradecene-8,10,12-triyne (2), respectively, from the EA fraction. Compounds 1 and 2 manifested highly specific and significant activities against HUVEC proliferation with IC50 values of 2.5 and 0.375 microg/ml, respectively, however, compound 1 had a more potent effect on preventing tube formation of HUVEC than compound 2 at a dose of 2.5 microg/ml. Western blot analysis showed that both compounds upregulated p27(Kip) or p21(Cip1), cyclin-dependent kinase inhibitors, in HUVEC. CONCLUSIONS: This is the first report to demonstrate that polyacetylenes possess significant anti-angiogenic activities and the ability to regulate the expression of cell cycle mediators, for example, p27(Kip1), p21(Cip1), or cyclin E.

Improvement of barrier function and stimulation of colonic epithelial anion secretion by Menoease Pills.

AIM: Menoease Pills (MP), a Chinese medicine-based new formula for postmenopausal women, has been shown to modulate the endocrine and immune systems. The present study investigated the effects of MP and one of its active ingredients, ligustrazine, on epithelial barrier and ion transport function in a human colonic cell line, T84. METHODS: Colonic transepithelial electrophysiological characteristics and colonic anion secretion were studied using the short circuit current (ISC) technique. RT-PCR was used to examine the expression of cytoplasmic proteins associated with the tight junctions, ZO-1 (zonula occludens-1) and ZO-2 (zonula occludens-2). RESULTS: Pretreatment of T84 cells with MP (15 microg/mL) for 72 h significantly increased basal potential difference, transepithelial resistance and basal ISC. RT-PCR results showed that the expressions of ZO-1 and ZO-2 were significantly increased after MP treatment, consistent with improved epithelial barrier function. Results of acute stimulation showed that apical addition of MP produced a concentration-dependent (10-5,000 microg/mL, EC50 = 293.9 microg/mL) increase in ISC. MP-induced ISC was inhibited by basolateral treatment with bumetanide (100 micromol/L), an inhibitor of the Na+-K+-2Cl- cotransporter, apical addition of Cl- channel blockers, diphenylamine-2, 2'-dicarboxylic acid (1 mmol/L) or glibenclamide (1 mmol/L), but not 4, 4'-diisothiocyanostilbene-2, 2'-disulfonic acid or epithelial Na+ channel blocker, amiloride. The effect of MP on ZO-1 and ZO-2 was mimicked by Ligustrazine and the ligustrazine-induced ISC was also blocked by basolateral application of bumetanide and apical addition of diphenylamine-2, 2'-dicarboxylic acid or glibenclamide, and reduced by a removal of extracellular Cl-. CONCLUSION: The results of the present study suggest that MP and lligustrazine may improve epithelial barrier function and exert a stimulatory effect on colonic anion secretion, indicating the potential use of MP and its active ingredients for improvement of GI tract host defense and alleviation of constipation often seen in the elderly.

Use of double-potential barrier to identify functional isthmus at the cavotricuspid isthmus for facilitating catheter ablation of isthmus-dependent atrial flutter.

INTRODUCTION: The aim of the study was to identify an alternative target for more effective radiofrequency catheter ablation (RFCA) of isthmus-dependent atrial flutter (AFL). METHODS AND RESULTS: We hypothesized that a functional isthmus formed by preexisting double potential barrier at the cavotricuspid isthmus (CTI) could serve as a new target site for facilitating RFCA of AFL. Forty-three consecutive patients with recurrent isthmus-dependent AFL were studied using three-dimensional navigated magnetic mapping and ablation technique. Twenty patients (47%, group A) were shown to have a narrower functional channel at the CTI (functional isthmus). The remaining 23 patients did not have this feature (53%, group B). In group A, double potentials were clustered near the border of the inferior vena cava (IVC) of the CTI and served as a functional channel along the tricuspid annulus (TA). The interspike interval of double potentials was 87 +/- 26 ms near the IVC border and 45 +/- 17 ms (P < 0.0001) near the TA border of CTI. RFCA targeting at the functional isthmus in group A resulted in interruption of bidirectional transisthmus conduction with fewer radiofrequency pulses (6.7 +/- 4.7 in group A vs 21.1 +/- 17.1 pulses in group B, P < 0.001), shorter ablation line (11.6 +/- 4.0 mm vs 37.8 +/- 7.2 mm, P < 0.0001) with no arrhythmia recurrence. These functional isthmuses were found to be located at the lateral third of CTI in 12 patients, middle third in 7, and medial third in 1. This finding is different from that obtained by the conventional method in group B (lateral in 5, middle in 16, medial in 2, P < 0.038). CONCLUSION: In our study, a functional, rather than anatomic, isthmus formed by preexisting double-potential barrier at the CTI was identified in 47% of patients with isthmus-dependent AFL. It is a useful guide to facilitate RFCA of isthmus-dependent AFL.

Cardiovascular protective effects of traditional Chinese medicine bak foong pills in spontaneously hypertensive rats.

The cardiovascular protective effects of the traditional Chinese medicine Bak Foong Pills (BFP) were investigated. Spontaneously hypertensive rats (SHR) were treated (3 g/kg) over a 5-month period and blood pressure measurements periodically tested with a plethysmographic tail cuff. Following treatment, blood samples were analysed for serum electrolyte levels and lipid levels and brain tissue subjected to micro-array analysis. In vitro experiments were also conducted to identify possible direct vasorelaxatory effect. The results showed that BFP was able to significantly reduce both systolic and diastolic blood pressure by about 30 mmHg in SHR following 5 months of treatment, when compared to untreated animals. Investigation for possible mechanisms of actions revealed that BFP treated rats had elevated blood serum K(+) levels, and also demonstrated decreased serum triglyceride levels. Micro-array analysis of brain tissue showed altered expression of acetylcholine and lysosphingolipid receptor genes that are known to regulate blood pressure. In vitro experiments also showed that BFP caused a concentration-dependant vasorelaxation of isolated rat aortae when contracted with phenylepherine, which was partially inhibited by nitric oxide synthase inhibitor L-NAME (100 microM). These data suggest that BFP is able to significantly reduce hypertension in SHR through mechanisms probably involving a combination of increased serum K(+), vasorelaxatory action, reduced serum triglyceride and altered gene regulation in the higher centres.

Electrophysiological mapping and histological examinations of the swine atrium with sustained (> or =24 h) atrial fibrillation: a suitable animal model for studying human atrial fibrillation.

OBJECTIVES: Interventional elimination of chronic persistent atrial fibrillation (AFib) remains difficult. An animal model mimicking the clinical situation is important. METHODS AND RESULTS: Twenty-five adult pigs were implanted with a high-speed atrial pacemaker. After continuous pacing at 600 bpm for 6 weeks, 20 (91%) of the 22 survivals developed sustained AFib lasting for at least 24 h. Epicardial dense mapping revealed multiple coexisting reentrant wavelets in the left and the right atrium (LA and RA, respectively; 10.6 +/- 2.9 vs. 7.6 +/- 2.4 wavelets/cm(2)/s; p < 0.002). The mean local A-A intervals were 87.2 +/- 14.6 ms in the LA and 103.3 +/- 19.0 ms in the RA (p < 0.0002). Acute termination of sustained AFib was successful in 3 of the 5 pigs by propafenone, but in none of the 6 by dl-sotalol. Epicardial cryothermal ablation failed to terminate any AFib by compartmentalization of the RA free wall alone (4 pigs) or together with the LA appendage (4 pigs). Electron microscopic examination demonstrated diffuse perinuclear myolysis, myofibrillar fragmentation and mitochondrial crystal disruption in the atrium. CONCLUSIONS: Pacing-induced sustained AFib (> or =24 h) in adult pigs is a feasible and efficient animal model with electrophysiological and histological characteristics closely similar to those seen in humans.