[Attention should be paid to the application of regional citrate anticoagulation in blood purification]

Compared with traditional low-molecular-weight heparin anticoagulation or non-anticoagulant hemodialysis, regional citrate anticoagulation (RCA) has emerged as a promising anticoagulant method considering its satisfactory efficacy, reduced incidence of bleeding, extended life of the dialyzer and increased removal of the toxin. RCA has received more and more attention in recent years which contributes as a first-line anticoagulant regimen for continuous renal replacement therapy, and it gradually gains wide clinical application in maintenance hemodialysis (MHD). In addition, RCA has been reported to be successfully used in plasma exchange and hemoperfusion. This article elaborates on mechanism of RCA and the problems in clinical application, in order to further expand the application of RCA and improve the effect of blood purification in the future.

[Current status of hyperkalemia in dialysis patients in China]

Objective: To investigate the prevalence and associated factors of hyperkalemia in dialysis patients. Methods: Patients underwent hemodialysis (HD) and peritoneal dialysis (PD) from multi-center databases were recruited from January 2017 to December 2019, and those aged ≥18 years and with dialysis duration ≥3 months were included to analyze the prevalence and related factors of hyperkalemia. Results: A total of 12 364 patients were enrolled in the study, and 6 836 cases were men. The average age of the patients was (51±15) years. Among these patients, 4 230 cases underwent HD while 8 134 received PD. Hyperkalemia was detected in 20.7% (2 554/12 364) of the patients while hypokalemia was found in 17.0%(2 102/12 364) of the patients. Multivariate logistic regression showed that HD (OR=2.25, 95%CI: 1.54-3.30), diabetes mellitus (DM) (OR=1.65, 95%CI: 1.17-2.32), high body mass index (BMI) (OR=1.06, 95%CI: 1.03-1.09), high levels of serum albumin (OR=1.04, 95%CI: 1.01-1.07) and phosphorus (OR=3.12, 95%CI: 2.44-4.00), low levels of serum bicarbonate (OR=0.89, 95%CI: 0.87-0.92), triglycerides (OR=0.76, 95%CI: 0.68-0.85) and creatinine (OR=0.95, 95%CI: 0.90-0.99), usage of angiotensin converting enzyme inhibitor/Angiotensin Ⅱ receptor antagonist (ACEI/ARB, OR=1.38, 95%CI: 1.11-1.72) and beta-blocker (OR=1.32, 95%CI: 1.07-1.64) were associated with hyperkalemia. Conclusions: Hyperkalemia occurred in 20.7% of the dialysis patients. HD, DM, high BMI, high levels of serum albumin and phosphorus, low levels of serum bicarbonate, triglycerides and creatinine, use of ACEI/ARB were associated with hyperkalemia.

Computational insights into the interaction mechanism of triazolyl substituted tetrahydrobenzofuran derivatives with H(+),K(+)-ATPase at different pH

The interaction mechanism of triazolyl substituted tetrahydrobenzofuran derivatives (compound 1 (N, N-Dipropyl-1-(2-phenyl-4,5,6,7-tetrahydrobenzofuran-4-yl)-1H-1,2,3-triazole-4-methanamine) and 2 (1-(2-Phenyl-4,5,6,7-tetrahydrobenzofuran-4-yl)-4-(morpholin-4-ylmethyl)-1H-1,2,3-triazole)) with H(+),K(+)-ATPase at different pH were studied by induced-fit docking, QM/MM optimization and MM/GBSA binding free energy calculations of two forms (neutral and protonated form) of compounds. The inhibition activity of compound 1 is measured and almost unchanged at different pH, while the activity of compound 2 increases significantly with pH value decreased. This phenomenon could be explained by their protonated form percentages and the calculated binding free energies of protonated and neutral mixture of compounds at different pH. The binding free energy of protonated form is higher than that of neutral form of compound, and the protonated form could be a powerful inhibitor of H(+),K(+)-ATPase. By the decomposed energy comparisons of residues in binding sites, Asp137 should be the key binding site to protonated form of compound because of the hydrogen bond and electrostatic interactions. These calculation results could help for further rational design of novel H(+),K(+)-ATPase inhibitors.

A D–π–A–π–A type dye for highly efficient dye-sensitized solar cells

We proposed and synthesized a novel D–π–A–π–A type dye (C321) and demonstrated its application in dye-sensitized solar cells.

Efficient fixation of CO2 by a zinc-coordinated conjugated microporous polymer

Zinc-coordinated conjugated microporous polymers (Zn-CMPs), prepared by linking salen zinc and 1,3,5-triethynylbenzene, exhibit extraordinary activities (turnover frequencies of up to 11600 h(-1) ), broad substrate scope, and group tolerance for the synthesis of functional organic carbonates by coupling epoxides with CO2 at 120 °C and 3.0 MPa without the use of additional solvents. The catalytic activity of Zn-CMP is comparable to those of homogeneous catalysts and superior to those of other heterogeneous catalysts. This catalyst could be reused more than ten times without a significant decrease in performance.

Tupisteroide A-C, three new polyhydroxylated steroidal constituents from the roots of Tupistra chinensis

Three new steroidal compounds with polyhydroxy groups, tupisteroide A-C (1-3), were obtained from the roots of Tupistra chinensis, together with one known compound (4) that was isolated from this plant for the first time. The structures of tupisteroide A-C were determined on the basis of one- and two-dimensional NMR spectroscopy, including (1) H-(1) H Correlation Spectroscopy, Heteronuclear Multiple Bond Correlation, and Heteronuclear Single Quantum Coherence experiments. The isolated compounds were evaluated for their cytotoxic activities against A549, HepG2, and CaSki cancer cell lines in vitro. Among them, compounds 1, 2, and 4 did not show significant inhibitory activity, but compound 3 showed cytotoxicity against A549 cancer cell lines with IC(50) values of 25.0 μM.

Five new furostanol saponins from the rhizomes of Tupistra chinensis

Five new furostanol saponins (1-5), together with three known compounds (6-8) were obtained from the n-butanol soluble fraction of ethanol extract from Tupistra chinensis. Their structures were determined on the basis of chemical methods and spectral data. The isolated compounds were tested in vitro for their cytotoxic activities against the A549, HepG 2 and Caski cancer cell lines. Among them, compounds 6, 7, and 8 showed cytotoxicity against A549 cancer cell lines with IC(50) values of 6.6, 6.7 and 29.1 μM, respectively.

[Clinical study of 1949 cases of port wine stains treated with vascular photodynamic therapy (Gu's PDT)]

BACKGROUND

Complete fading of port wine stains (PWS) is difficult to achieve with current laser treatments. Photodynamic therapy (Gu's PDT) could offer a very efficient alternative for PWS therapy.

PATIENTS AND METHOD

1949 lesions in 1385 patients were treated by PDT. Each patient received an intravenous injection of hematoporphyrin derivative (HpD) or hematoporphyrin monomethyl ether (HMME) at 3-7 mg/kg. Laser irradiation was performed on a 2 to 8 cm spot size. Different wavelengths (488.0 nm to 578.2 nm) were evaluated with a power density of 50-100 mW/cm2. Fluences ranged from 90 to 540 J/cm2.

RESULTS

Among the 1942 lesions, PWS clearance was observed in 99.7% of cases. Excellent results were achieved in 128 lesions (6.6%) (100% clearance), 746 lesions (38.3%) yielded to good results (clearance > 75%), 923 lesions (47.4%) showed moderate results (clearance 50-75%), 145 lesions (7.4%) showed poor results (clearance<50%) and in 7 lesions (0.3%) no visible change was observed. The pink port wine stains revealed better response to Gu's PDT with only one session. Conversely, purple stains in adult patients required 2 sessions or more.

CONCLUSION

This new PDT technique is effective and highly selective, with almost no risk of scarring.

A survey of microbial contamination of food contact surfaces at broiler slaughter plants in Taiwan

Microbial contamination levels at broiler slaughter plants were investigated at three major slaughter plants in Taiwan during the summer and winter. The microbial contamination levels in chicken carcasses and on food contact surfaces were examined using the swab method. The results indicated that the bacterial counts were affected by the slaughter processing plant, processes, and season (P < 0.05). The bacterial counts on food contact surfaces of the equipment before operation were not significantly lower than those after processing. Regardless of the bacterial type, bacterial counts of chicken carcasses generally decreased from the scalding step to the washing step before evisceration and then increased. The cleaning procedures for food contact surfaces should be evaluated, and special attention should be given to utensils used during processing, such as gloves, baskets, and hand tools.

Mechanism responsible for initiating carbon nanotube vacuum breakdown

We report a physical mechanism responsible for initiating a vacuum breakdown process of a single carbon nanotube (CNT) during field emission. A quasidynamic method has been developed to simulate the breakdown process and calculate the critical field, critical emission current density and critical temperature beyond which thermal runaway occurs before the CNT temperature reaches its melting point. This model is in good agreement with experiments carried out with a single CNT on a silicon microtip.

Chronic antidepressant treatments increase cytochrome b mRNA levels in mouse cerebral cortex

Antidepressant therapies include drugs with a remarkable structural diversity and non-pharmacological interventions, such as electroconvulsive shock. Although the primary neurochemical effects of these treatments may differ, the > or = 2- to 3-wk lag in therapeutic onset has led to the hypothesis that adaptive changes in a final common pathway are required for an antidepressant action. Based on this hypothesis, we sought to identify and characterize common changes in gene expression following chronic antidepressant treatments. We utilized a differential display strategy to identify genes that were differentially expressed in mice following chronic treatment with imipramine and electroconvulsive shock. Differential display PCR followed by subcloning, screening by reverse Northern blot, and confirmation by Northern blot revealed a significant increase in the expression of one gene candidate from mouse cortex following antidepressant treatments. The sequence of this 193-bp gene candidate was an exact match to the DNA sequence of mouse mitochondrial cytochrome b. In contrast to the increased mRNA levels of cytochrome b found in cortex, chronic treatment with these antidepressants did not alter mRNA levels in hippocampus, cerebellum, or liver. Moreover, no differences in cortical levels of cytochrome b mRNA were observed after either acute antidepressant treatments or chronic treatment with nonantidepressant drugs (haloperidol and morphine). The observation that chronic, but not acute treatment with imipramine and electroconvulsive shock produces a region-specific change in the levels of mRNA encoding cytochrome b suggests that this enzyme may be involved in the sequence of events resulting in an antidepressant action.

Extraneuronal uptake inhibitor U-0521 decreases contractile responses in rat vas deferens

1. The influence of catechol-O-methyltransferase inhibitor U-0521 on isotonic contraction of isolated rat vas deferens was examined to determine optimal concentration and nonspecific effects. 2. Maximum responses to (-)-epinephrine were increased at 0.4 microM and 1 microM concentrations of U-0521. Epinephrine responses were progressively decreased in the presence of higher concentrations (10 microM, 30 microM and 100 microM) of U-0521. 3. The response to the nonadrenergic agonist neurokinin A was similarly depressed in the presence of 100 microM U-0521. 4. U-0521 not only inhibits COMT, at concentrations above 1 microM it nonspecifically depresses contraction of the rat vas deferens by both adrenergic and nonadrenergic agonists.

Persistent spontaneous oral dyskinesias in haloperidol-withdrawn rats neonatally lesioned with 6-hydroxydopamine: absence of an association with the Bmax for [3H]raclopride binding to neostriatal homogenates

To investigate the influence of dopamine (DA) nerves on haloperidol (HAL)-induced oral dyskinesias, rats were first injected at 3 days after birth with 6-hydroxydopamine HBr (200 micrograms i.c.v., salt form; 6-OHDA) or vehicle, after desipramine HCl (20 mg/kg i.p., 1 hr) pretreatment. Two months later HAL (1.5 mg/kg/day, 2 days a week for 4 weeks, then daily for 10 months) was added to the drinking water of half the rats. Numbers of vacuous chewing movements, recorded in 1-min increments every 10 min for 1 hr, increased from < 5 to about 17 oral movements per session in intact rats, 14 weeks after instituting HAL (P < .01 vs. intact rats drinking tap water). In HAL-treated 6-OHDA-lesioned rats, oral activity increased to > 30 oral movements per session (P < .01 vs. HAL-treated intact rats). These levels of oral activity persisted in intact and 6-OHDA-lesioned rats as long as HAL was administered. After 11 months of HAL treatment, but 8 or 9 days after HAL withdrawal, DA was found to be reduced 97%, whereas serotonin was increased 29% in the striatum of 6-OHDA-lesioned rats. In HAL-treated intact and lesioned rats the Bmax for DA D2 binding sites was elevated about 70%. With reverse transcription polymerase chain reaction, the mRNA level for DA D2L but not D2S receptors was also found to be elevated about 70%. In a fraction of 6-OHDA-lesioned rats that were observed for 8 months after HAL withdrawal, oral activity persisted without decrement and was not accompanied by a change in the Bmax or mRNA level for DA D2 receptors. These findings demonstrate that in rats largely DA-denervated as neonates, long-term HAL treatment produces an unusually high number of oral movements that persists for 8 months after HAL withdrawal and is not accompanied by an increase in DA D2 receptor expression.

Persistent oral dyskinesias in haloperidol-withdrawn neonatal 6-hydroxydopamine-lesioned rats

Because chronic haloperidol-treated rats demonstrate an increased incidence of spontaneous oral activity, while neonatal 6-hydroxydopamine-lesioned rats demonstrate an increased incidence of dopamine agonist-induced oral activity, we studied the influence of haloperidol in 6-hydroxydopamine-lesioned rats. At 3 days after birth rats received 6-hydroxydopamine hydrobromide (200 micrograms intracerebroventricularly; desipramine pretreatment, 20 mg/kg i.p., 1 h) or vehicle. Two months later haloperidol (1.5 mg/kg per day x 2 days per week, for 4 weeks; then 1.5 mg/kg per day, every day for 10 months) was added to the drinking water. After 15 weeks the level of spontaneous oral activity was stable. At 11 months there were 35.8 +/- 4.9 vs. 18.4 +/- 2.1 oral movements in 6-hydroxydopamine-lesioned vs. intact rats receiving haloperidol. This effect persisted unabated in lesioned rats for 4 months after haloperidol withdrawal. This stable high frequency of oral dyskinesias is an advantage for studying putative therapeutic drugs for tardive dyskinesia.

Enhanced oral activity response to A77636 in neonatal 6-hydroxydopamine-lesioned rats

To study the role of dopamine D1 receptors in enhanced oral activity effects of SKF 38393 ((+-)-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine-7,8-diol) in neonatal 6-hydroxydopamine-lesioned rats, SKF 38393 was compared to the full agonist, A77636 ((1R,3S)-3-(1'-adamantyl)-1-aminomethyl-3,4-dihydro-5,6-dihydroxy- 1H-2-benzopyran). At 3 days after birth rats were treated with 6-hydroxydopamine HBr (200 micrograms salt form, i.c.v.; desipramine (20 mg/kg i.p.), 1 h) or vehicle. At 6-8 months a 0.01 mg/kg dose of A77636 HCl increased oral activity in 6-hydroxydopamine vs. control rats (P < 0.01). A77636 and SKF 38393 produced identical maximal responses of 35-36 oral movements at 0.1 and 1.0 mg/kg, respectively. SCH 23390 (R-(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benz azepine ) HCl (0.3 mg/kg i.p.) attenuated the response to A77636. Neither A77636 HCl (0.01-1.0 mg/kg i.p.) nor SKF 38393 HCl (0.03-3.0 mg/kg i.p.) induced oral activity in intact rats. The findings demonstrate that A77636 is more potent than SKF 38393, and that supersensitized dopamine D1 receptors are involved in the induction of oral behavior in neonatal 6-hydroxydopamine-lesioned rats.