An investigation into the present status and influencing factors of nurse retention in grade-a tertiary general hospitals in Shanxi Province within the framework of the magnet hospital concept

BACKGROUND

The attrition of nursing staff significantly contributes to the shortage of healthcare professionals. This study entailed an examination of the propensity of nurses to sustain employment within Grade-A tertiary general hospitals and the various influencing factors.

METHODS

A total of 2,457 nurses from three grade-A tertiary general hospitals were surveyed. The survey instruments included a general information questionnaire, a scale measuring their willingness to continue working, and a Chinese version of the Magnet Hospital Factor scale.

RESULTS

The scores of the willingness to continue working scale and the Magnet Hospital Factor scale were 21.53 ± 4.52 and 145.46 ± 25.82, respectively. There were statistically significant differences in the scores of willingness of nurses to continue working across various factors, including the department, age, marital status, family location, length of service as nurses, professional title, position, and employment type, upon comparison (P < 0.001). The correlation analysis showed that there was a positive correlation between the willingness of nurses to continue working and the magnet hospital factors, with a correlation coefficient of 0.523 (P < 0.01). Regression analysis showed that department, length of service as nurses, professional title, position, average monthly income, number of night shifts, medical care relationship, educational support, and nursing manager support among the magnet hospital factors were important predictors of willingness to continue working (P < 0.001).

CONCLUSION

The willingness of nurses to continue working in grade-A tertiary general hospitals in Shanxi Province was determined to be at an upper-middle level. The magnet status of grade-A tertiary general hospitals needs to be improved, and there are many factors that influenced willingness of nurses to continue working. To cultivate a more favorable environment and bolster nurse recruitment and retention, all healthcare institutions should strive to establish a magnet nursing environment, thereby fostering the robust development of the nursing team.

[Screening of traditional Chinese medicine-derived snail control drug targets based on network pharmacology]

OBJECTIVE

To screen the targets of traditional Chinese medicine-derived potential plant molluscicides based on network pharmacology and explore the mechanisms of molluscicidal actions.

METHODS

The traditional Chinese medicines with molluscicidal actions were screened based on retrospective literature reviews, and their molluscicidal efficiency was summarized. The active ingredients and potential targets of traditional Chinese medicines were captured from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform, Unified Protein Database and literature mining using network pharmacology. The drug-active ingredient-target network was created using the software Cytoscape 3.7.2, and the key targets were subjected to Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis using the Metascape software.

RESULTS

A total of 27 types of snail control drugs derived from traditional Chinese medicines were screened from publications and classified into 14 categories. Network pharmacology identified 190 active ingredients, and the active ingredients with a high degree in the drug-active ingredient-target network included quercetin, linoleyl acetate, luteolin, beta-carotene, (24S)-ethylcholesta-5,22,25-trans-3beta-ol, fumarine and arctiin, with 181 corresponding potential targets screened. KEGG pathway enrichment analysis revealed that these targets were mainly located in 16 pathways, including the neuroactive ligand-receptor interactions, regulation of adipocyte lipolysis and adrenergic signal in myocardial cells.

CONCLUSIONS

This study preliminarily demonstrates the multi-ingredient, multi-target and multi-pathway mechanisms of action of 27 molluscicides. The screened key ingredient may provide the basis for isolation, purification and pharmacological studies of molluscicides, and the screened key targets and key pathways may facilitate the illustration of mechanisms of actions of traditional Chinese medicine-derived molluscicides and development of novel green molluscicides.

Effects of tai chi and qigong on rehabilitation after COVID-19: a protocol for systematic review and meta-analysis

INTRODUCTION

COVID-19 is a public health emergency of international concern, which is characterised by rapid and widespread transmission, high mortality and complications. Several studies have shown the benefits of tai chi and qigong for recovery after COVID-19; however, no meta-analysis has been reported. Therefore, the purpose of this study is to evaluate the efficacy and safety of tai chi and/or qigong on rehabilitation after COVID-19 through a systematic review and meta-analysis to provide a reference and basis for clinical application.

METHODS AND ANALYSIS

This study will use the Cochrane Library, PubMed, Web of Science, Embase, China Knowledge Network, China Biomedical Literature Database, Chinese Scientific Journal Database and Wanfang Database. The time period is from the inception of the database to November 2021, with no language restrictions. Searches will be conducted using the subject terms "Taichi","Qigong" and "COVID-19" plus free-text words. Articles will be screened and collected by two reviewers independently. Included studies will be assessed for quality using the Cochrane Risk of Bias Assessment Tool. Statistical analyses will be performed using the Revman V.5.3 software. The primary outcomes include 1-second forced expiratory volume and 1-second forced vital capacity, oxygen saturation, total white cell count and quality of life score. Secondary outcomes include time to remission of major symptoms, incidence of adverse events, clinical cure rate and mortality. Subgroup and sensitivity analyses will also be used to explore and interpret the heterogeneity. This protocol is written based on the guideline of the Preferred Reporting Items for Systematic Reviews and Meta-analyses Protocol.

ETHICS AND DISSEMINATION

Ethical approval and consent are unnecessary because no primary data will be collected. The results will be disseminated through peer-reviewed publications.

PROSPERO REGISTRATION NUMBER

CRD42021288962.

Time to Occurrence of Phlebitis After Continuous Infusion of Total Nutrient Admixture Through Peripheral Veins: An Experimental Animal Study

OBJECTIVE

To study the limit time of phlebitis caused by continuous infusion of KabivenTM Pl and TNA (KabivenTM Pl+ alanyl glutamine + potassium aspartate) through a peripheral vein, and to provide a reference for clinical formulation of preventive measures for phlebitis.

METHODS

White rabbits (n = 72) were randomly divided into three groups: group A (Normal saline), group B (Kabiven™ Pl), and group C (TNA). Blood was collected from the ear margin vein before administration and after three hours, four hours, five hours, and six hours of administration. CRP and TNF-ɑ were measured by enzyme-linked immunosorbent assay. Hematoxylin and eosin staining and immunohistochemical staining were performed on tissue samples taken from the insertion point of the indwelling needle, the tip of the indwelling needle, and 1 cm from the tip of the indwelling needle, closer to the heart, to analyze early pathological changes in blood vessels.

RESULTS

(1) There were no visible inflammatory symptoms in groups A, B, or C within 6 hours. (2) Four hours after starting intravenous administration, the levels of inflammatory markers in groups B and C were higher than in group A, and (3) the degree of inflammatory cell infiltration in groups B and C was more severe than in group A. (4) In all groups, the inflammatory reaction at the tip of the indwelling needle was more severe than at the other two sites.

CONCLUSION

When the emulsions TNA and Kabiven™ Pl are infused through a peripheral vein, (1) four hours may be considered as the maximum time for continuous intravenous infusion in the same vein before inflammatory changes become evident, and (2) systematic assessment of the tip of the indwelling needle should be considered for inclusion in the nursing plan for phlebitis monitorings.

Carbon emissions embodied in the global supply chain: Intermediate and final trade imbalances

By differentiating intermediate trade from final trade, this paper combines typical statistics for the world economy in 2012 to explore the transfer of embodied carbon emissions via the global supply chain and the related trade imbalance. The emission transfer embodied in interregional trade is in magnitude around 40% of global direct carbon emissions. The global intermediate trade volume of embodied carbon emissions is estimated to be 2.3 times as much as the final trade volume. While Mainland China obtains a considerable economic trade surplus, its carbon trade deficit is about twice the carbon trade surplus of the United States. Mainland China's final trade deficit is around 1.2 times as much as its intermediate trade deficit of embodied carbon emissions. EU27, the United States, ASEAN and Japan serve as the major contributors to China's intermediate and final trade deficits. For the United States, its intermediate carbon trade surplus is almost equal to its final trade surplus. The United States gains a carbon surplus with most of its trading partners in both intermediate and final trades. A future scenario analysis in terms of carbon emission projection is conducted. While the direct and embodied carbon emissions of the United States and Japan are estimated to change slightly from 2012 to 2040, India's carbon emissions are projected to experience a twofold increase during the period. In the long term, though with ups and downs, the economic globalization will be inevitably moving forward, leading to a highly sliced-up global supply chain and increasingly delicate regional specialization as well as frequent intermediate trade between regions. It is suggested that nations and regions should follow this trend and adapt themselves to the global value chain by carefully assessing their roles in intermediate and final trades in terms of both currency and embodied carbon emissions.

Energy use by globalized economy: Total-consumption-based perspective via multi-region input-output accounting

Within a single integrated globalized economy featuring robust fluxes of interregional trades, the world economy is like a giant bathtub containing the world inventory of energy use. Based on different norms or ethic percepts, the energy use of the world economy is reallocated to nations and regions via global supply chain using normative accounting schemes. By combining typical statistics for world economy 2012, a new perspective is presented in this study to look into the energy use of regional economies from the side of genuine final consumers. Parallel to the final-demand-based accounting method, a total-consumption-based multi-region input-output accounting method is developed following the norm of consumption being the ultimate end and purpose of all producing activities. From a total-consumption-based perspective, the energy use of the United States economy is shown in magnitude 1.8 times that of mainland China, compared to a ratio of 88% from a territorial-based perspective. The consumer-product-related trade imbalances of major economies in terms of both currency and energy use are analyzed, with major interregional net trade flows illustrated. While the United States and mainland China are respectively revealed as the leading net exporter and net importer of currency, the energy trade deficit of the latter is in magnitude around four times the energy trade surplus of the former. The trade structures by geography and sector are respectively presented for the United States and mainland China as two distinct economies. It is found that around half of the United States' exports of energy use originate from transport and service industries, while nearly 90% of mainland China's exports of energy use come from heavy industry. The findings are supportive for nations to identify their roles in the global supply chain from the perspective of genuine final consumers and adjust the trade patterns for sustained energy use.

Non-uniform Evolving Hypergraphs and Weighted Evolving Hypergraphs

Firstly, this paper proposes a non-uniform evolving hypergraph model with nonlinear preferential attachment and an attractiveness. This model allows nodes to arrive in batches according to a Poisson process and to form hyperedges with existing batches of nodes. Both the number of arriving nodes and that of chosen existing nodes are random variables so that the size of each hyperedge is non-uniform. This paper establishes the characteristic equation of hyperdegrees, calculates changes in the hyperdegree of each node, and obtains the stationary average hyperdegree distribution of the model by employing the Poisson process theory and the characteristic equation. Secondly, this paper constructs a model for weighted evolving hypergraphs that couples the establishment of new hyperedges, nodes and the dynamical evolution of the weights. Furthermore, what is obtained are respectively the stationary average hyperdegree and hyperstrength distributions by using the hyperdegree distribution of the established unweighted model above so that the weighted evolving hypergraph exhibits a scale-free behavior for both hyperdegree and hyperstrength distributions.

The Evolution of Hyperedge Cardinalities and Bose-Einstein Condensation in Hypernetworks

To depict the complex relationship among nodes and the evolving process of a complex system, a Bose-Einstein hypernetwork is proposed in this paper. Based on two basic evolutionary mechanisms, growth and preference jumping, the distribution of hyperedge cardinalities is studied. The Poisson process theory is used to describe the arrival process of new node batches. And, by using the Poisson process theory and a continuity technique, the hypernetwork is analyzed and the characteristic equation of hyperedge cardinalities is obtained. Additionally, an analytical expression for the stationary average hyperedge cardinality distribution is derived by employing the characteristic equation, from which Bose-Einstein condensation in the hypernetwork is obtained. The theoretical analyses in this paper agree with the conducted numerical simulations. This is the first study on the hyperedge cardinality in hypernetworks, where Bose-Einstein condensation can be regarded as a special case of hypernetworks. Moreover, a condensation degree is also discussed with which Bose-Einstein condensation can be classified.

Proteome analysis of the liver in the Chinese fire-bellied newt Cynops orientalis

The Chinese fire-bellied newt, Cynops orientalis, belonging to Amphibia, Caudata, Salamandridae is a species endemic to China. The liver, which is an important digestive gland and the largest amphibian organ, has various functions, including detoxification, glycogen storage, protein synthesis, and hormone production. However, the newt liver has rarely been studied at the molecular level. We performed histomorphology and high-throughput proteomic analysis of the Chinese fire-bellied newt liver, using hematoxylin and eosin (H&E) staining and two-dimensional electrophoresis coupled with mass spectrometry. The H&E staining showed that the newt liver nuclei are large and round, are located in the lateral cytoplasm, and contain a large quantity of lipid droplets. Melanins were abundantly present throughout the hepatic parenchyma. The proteome analysis showed a total of 545 proteins detected in the newt liver. Furthermore, a gene ontology analysis suggested that these proteins were associated with metabolism, immune response, cellular homeostasis, etc. Among these, proteins with metabolic functions were found to be the most abundant and highly expressed. This supports the role of the liver as the metabolic center. The proteomic results provide new insights into the aspects of the liver proteomes of the Chinese fire-bellied newt. The identification of a more global liver proteome in the newt may provide a basis for characterizing and comparing the liver proteomes from other amphibian species.

Brand effect versus competitiveness in hypernetworks

A few of evolving models in hypernetworks have been proposed based on uniform growth. In order to better depict the growth mechanism and competitive aspect of real hypernetworks, we propose a model in term of the non-uniform growth. Besides hyperdegrees, the other two important factors are introduced to underlie preferential attachment. One dimension is the brand effect and the other is the competitiveness. Our model can accurately describe the evolution of real hypernetworks. The paper analyzes the model and calculates the stationary average hyperdegree distribution of the hypernetwork by using Poisson process theory and a continuous technique. We also address the limit in which this model has a condensation. The theoretical analyses agree with numerical simulations. Our model is universal, in that the standard preferential attachment, the fitness model in complex networks and scale-free model in hypernetworks can all be seen as degenerate cases of the model.

The effectiveness of an integrated multicomponent program for adolescent smoking cessation in Taiwan

If adolescents do not receive appropriate assistance in quitting smoking, they are highly likely to become regular smokers when they enter adulthood. Thus, an effective smoking-cessation program is required. A program was designed based on both the smoking-cessation barriers reported by students and effective strategies derived from the literature. We assigned 143 student smokers from 6 vocational high schools to intervention (n=78) and comparison groups (n=65). Data were collected at the baseline, the end of the program, and 1- and 4-month follow-up time points. For the intervention group, the smoking-abstinence rates confirmed using the urine cotinine test were 22.73% at the end of the program and 20.75% at the 4-month follow-up point. Days smoked in the past month, number of cigarettes smoked per day, and the Fagerström Test for Nicotine Dependence score of the intervention group decreased at all of the time points. The group differences in these variables were statistically significant; the magnitude of effect sizes ranged from 0.44 to 0.95. Multicomponent programs addressing smoking-cessation barriers that students encounter can help adolescents quit smoking.

Isolation and characterization of polymorphic microsatellite loci from aerial yam (Dioscorea bulbifera L.)

Dioscorea bulbifera L. is widely distributed in pantropical regions along the equator. The taxonomic treatment of this species is ambiguous due to its extreme polymorphic morphological characters. In order to provide tools to facilitate the study of genetic diversity, population structure, patterns of gene flow, and the mating system of this species, and to assess intraspecific variability and relationships in D. bulbifera, 14 novel polymorphic microsatellite loci were developed using the dual-suppression PCR technique. The number of alleles per locus ranged from 4 to 17, with an average of 9.93. The mean observed heterozygosities were 0.7327 and 0.7223, and the mean Shannon-Wiener indices were 1.6431 and 1.811 in the Nanjing and Nanchong populations, respectively. All novel microsatellite loci showed high levels of polymorphism, indicating that these markers offer great potential significance and profound influence for future studies of this species.

Isolation and characterization of microsatellite DNA loci for wild Brassica juncea (Brassicaceae)

Wild Brassica juncea is a widespread weed in China with increasingly great impact on the yield of many crops. This study aimed to develop microsatellite markers for assessing the genetic diversity and population genetic structure of B. juncea, and to provide basic information for biological and chemical control of the weed. The compound microsatellite marker technique was used to develop markers for investigating population genetics of wild B. juncea. Twelve loci were obtained, each of which showed high polymorphisms when tested in two populations in Sichuan and Jiangsu Provinces. The number of alleles per locus ranged from 4 to 27, with an average of 15.2 alleles per locus. The newly developed microsatellite loci will be informative for further investigations of the population genetics and evolutionary patterns of wild B. juncea.

DNA barcoding of populations of Fallopia multiflora, an indigenous herb in China

Fallopia multiflora, locally known as Heshouwu, is one of the most important and widely used Chinese medicinal herbs. However, there is still considerable confusion concerning its different provenances. DNA barcoding is a recent aid to taxonomic identification and uses a short standardized DNA region to discriminate plant species. We assessed the applicability of 4 candidate DNA barcodes (matK, rbcL, psbA-trnH, and ITS2) to identify populations of F. multiflora. To our knowledge, this is the first attempt involving the plant kingdom to apply DNA barcoding at a level lower than species. Four DNA loci (matK, rbcL, psbA-trnH, and ITS2) of 105 samples, including the wild F. multiflora distributed in 17 provinces of China and 4 cultivated F. multiflora lines, were amplified by PCR and sequenced. The 4 loci were evaluated by PCR amplification for sequence quality, extent of genetic divergence, DNA barcoding gap, and the ability to discriminate between populations by BLAST1 and Nearest Distance. We found that psbA-trnH was the best barcode, with significant inter-population variability and best potential for identifying F. multiflora. The combination of loci gave better performance for distinguishing populations than a single locus. We recommend using matK + rbcL + psbA-trnH + ITS2 or psbA-trnH alone for this species. This research demonstrates the utility of DNA barcoding for geoherbalism identifications.

Estrogen receptor beta variants mRNA expressions in gastric cancer tissues and association with clinicopathologic parameters

BACKGROUNDS/AIMS

The aim of this study is to examine the expression of estrogen receptor beta-1, 2 ,5 in gastric cancer tissues and evaluate their correlation with clinicopathological features.

METHODOLOGY

Real-time quantitative PCR assay was applied to detect the expression of estrogen receptor beta-1, 2, 5 mRNAs in 44 gastric cancer tissues and their paired normal tissues and correlate their mRNA levels with the clinicopathological properties of the tumors. 2(deltaCT) method was used to obtain the relative quantity of target mRNA expression.

RESULTS

In almost all patients, estrogen receptor beta-1, 2, 5 mRNAs were expressed in gastric cancers and their matched normal tissues; however estrogen receptor beta-5 mRNA was not found in 8 normal gastric tissues. Estrogen receptor beta-5 had a much higher expression than estrogen receptor beta-1, 2 in gastric cancer tissues. Higher estrogen receptor beta-5 mRNAlevel was observed in gastric cancers than matched normal tissues (p = 0.001) and its increased expression was correlated with pTNM stage of the tumor (p = 0.032) and the lymph node metastasis (p = 0.026). Decreased mRNA level of estrogen receptor beta-1 was observed in gastric cancers compared to their matched normal tissues (p = 0.008). Estrogen receptor beta-1, 2 were not correlated with lymph node metastasis, gender, age, tumor size, tumor grade and pTNM stage (p > 0.05).

CONCLUSIONS

This is the first study investigating the clinicopathologic role of estrogen receptor beta variants in gastric cancer. Our study shows that estrogen receptor beta-5 is the most important factor for gastric cancer development and progression among the three estrogen receptor beta variants.

Prognostic role of estrogen receptor alpha and estrogen receptor beta in gastric cancer

BACKGROUND

The presence of estrogen receptor alpha (ERalpha) and estrogen receptor beta (ERbeta) have been reported in cell and tissue level in gastric cancer, but its impact on patients' survival remains unclear. This study was designed to investigate the expression level of ERalpha and ERbeta and to assess clinical significance of ERalpha and ERbeta expression in gastric cancer.

METHODS

The expression level of ERalpha and ERbeta were assessed by reverse-transcriptase polymerase chain reaction (RT-PCR) in 35 surgically resected gastric cancer and corresponding normal tissues and by immunohistochemical staining in 211 surgically resected gastric cancer and match normal tissues.

RESULTS

The expression level between ERalpha mRNA expression in gastric cancer tissues and match normal tissues had no statistically significant difference. The ERbeta mRNA level in normal tissues was significantly higher than that observed in gastric cancer tissues (P = 0.001). Neither ERalpha nor ERbeta mRNA expression levels had significant correlation with clinicopathologic parameters. Forty-eight of 211 (22.7%) gastric cancer tissues showed positive expression of ERalpha and ERbeta detected in gastric cancer. ERalpha-positive expression correlated with poorer overall survival (P = 0.014), as did the absence of ERbeta expression in patients with gastric cancer (P = 0.001). In multivariate analysis, the positive expression of ERalpha and the absence of ERbeta were significant independent prognostic factors for overall survival (hazard ratio 2.159, P = 0.013, and hazard ratio 2.016, P = 0.025 respectively).

CONCLUSIONS

Our results indicated that ERalpha and ERbeta were expressed in both gastric cancer and corresponding normal tissues. ERalpha expression and the absence of ERbeta expression are associated with poor survival.

Molecular cloning and expression analysis of a novel CONSTANS-like gene from potato

A full-length cDNA of a StCONSTANS-like (StCOL) gene was cloned from potato (Solanum tuberosum L.) by RT-PCR and RACE. The predicted amino acid sequence of this cDNA has a high degree of identity with other homologous members of the CO or COL family. Analysis of mRNA levels for StCOL shows that it is highly expressed in leaves and becomes weaker during tuberization; moreover, is independent of gibberellin A(3) and sucrose.

Individual and contextual factors related to family practice residents' assessment and counseling for tobacco cessation

BACKGROUND

Tobacco use is the chief avoidable cause of death in the United States. Physicians, however, are not routinely assessing this risk and providing counseling for risk reduction. This study examines tobacco cessation counseling practices among family practice residents and explores the determinants of residents' smoking-counseling behaviors and counseling duration.

METHODS

One hundred ten family practice residents (response rate = 93.2%) from four Texas residency training programs completed a survey designed to assess tobacco cessation counseling practices.

RESULTS

A high proportion of residents reported that they usually or always assessed tobacco use (59.3%) and advised their patients to quit smoking (80.9%), with a lower proportion reporting specific counseling behaviors (7.3% - 21.9%), referrals (1.8%), or follow-up visits (1.8%). Year of residency, perceived effectiveness, and the interaction between perceived effectiveness and residency year were significantly associated with number of counseling behaviors, and year of residency and perceived effectiveness were significantly associated with counseling duration.

CONCLUSIONS

Faculty physicians should assist residents to implement the Public Health Service-sponsored clinical practice guideline for tobacco control. There is a need to increase behavioral skills and perceived effectiveness for assessing and counseling smokers among first-year residents.

[Observation of the effectiveness of APFI gel to prevent dental caries]

OBJECTIVE

To observe the effectiveness of APFI Gel applied to pupils to prevent dental caries.

METHODS

2918 cases of 6 to 13 years old pupils from four urban and countryside primary schools were randomly divided into two groups,the experiment group and the control group. By theirs different school and classes and groups, APFI Gel was used to 2 160 cases of the experimental group to prevent dental caries. The control group consisted of 758 cases. The incidence of dental caries of the two groups were observed in the same time and using the same way.

RESULTS

Statistical analysis indicated that the incidence of dental caries in the experimental group decreased by 52.3%,the newly increased DMFT decreased by 60.14% (P<0.01). The incidence of dental caries of the first molar decreased by 52.43%,the newly increased DMFT decreased by 65.52% (P<0.01).

CONCLUSION

It is effective to use APFI Gel to prevent caries.

The impact of Put Prevention into Practice on selected clinical preventive services in five Texas sites

OBJECTIVE

To determine whether the implementation of the Put Prevention Into Practice (PPIP) office-based system would increase the delivery rates of specific clinical preventive services among demonstration clinics.

METHODS

Chart review was conducted before (n=372) and 33 to 39 months after (n=376) the implementation of the PPIP office-based system in two community health centers and three family practice residency programs in Texas. The population included all adult patients aged > or = 19 years who had presented to the clinic during the study periods.

RESULTS

Documentation of timely cholesterol screening increased from 70% to 84%; smoking assessment, from 56% to 80%; for women, up-to-date Papanicolaou smear, from 70% to 81%; annual mammograms (women aged > or =51), from 30% to 48%; and up-to-date tetanus-diphtheria immunizations, from 19% to 59%. For adults aged > or =66 years, documentation of pneumococcal immunization increased from 22% to 48%, while influenza immunizations improved, although not significantly (45% to 49%). Blood pressure screening was almost universal (99%) at baseline and at 33- to 39-month follow-up.

CONCLUSION

PPIP system changes were associated with an observed increase in delivery of selected clinical preventive services.

Role of peroxynitrite in [3H] gamma-aminobutyric acid release evoked by nitric oxide and its mechanism

Role of peroxynitrite in [3H] gamma-aminobutyric acid (GABA) release evoked by N-methyl-D-aspartate (NMDA) and S-nitroso-N-acetyl-penicillamine (SNAP) and mechanisms of [3H]GABA release induced by peroxynitrite in comparison with those induced by NMDA and SNAP were investigated using cerebrocortical neurons. NMDA dose dependently increased [3H]GABA release, which was significantly inhibited by hemoglobin and superoxide scavengers, Cu2+, Zn(2+)-superoxide dismutase and ceruloplasmin. The NMDA-evoked [3H]GABA release was significantly suppressed by GABA transport inhibitors and inhibitors of voltage-dependent L-typed Ca2+ channel. The SNAP-evoked [3H]GABA release was significantly reduced by Ca2+ withdrawal and by GABA transport inhibitors either in the presence or absence of Ca2+. Similar patterns of [3H]GABA release induced by peroxynitrite were observed. These results indicate that peroxynitrite formed by the reaction of NO with superoxide participates, in part, in the release of [3H]GABA induced by NMDA and SNAP.

Hydroxyl radical scavengers enhance nitric oxide-evoked acetylcholine release from mouse cerebral cortical neurons

The effect of hydroxyl radical scavengers on acetylcholine (ACh) release evoked by nitric oxide (NO) generators and N-methyl-D-aspartate (NMDA) was investigated. Dimethylthiourea enhanced dose-dependently NO generators-evoked ACh release. Similarly, uric acid and mannitol significantly facilitated ACh release evoked by NO generators. The NMDA-induced ACh release was also significantly facilitated by hydroxyl radical scavengers. These scavengers themselves showed no effects on ACh release. These results suggest that hydroxyl radicals may modify the mechanism for NO-evoked ACh release.

Involvement of peroxynitrite in N-methyl-D-aspartate- and sodium nitroprusside-induced release of acetylcholine from mouse cerebral cortical neurons

Functional roles of peroxynitrite in N-methyl-D-aspartate (NMDA)- and sodium nitroprusside (SNP)-evoked releases of acetylcholine (ACh) from cerebral cortical neurons in primary culture have been investigated. NMDA increased the release of ACh in a dose-dependent manner, which was significantly suppressed by (+)-5-methyl-10,11-dihydro-5H-dibenzo-[a,d]cycloheptan-5,10-imine (MK-801), a non-competitive antagonist specific for the NMDA receptor complex, and NO synthase inhibitors. SNP also showed a concentration-dependent increase in ACh release. Hemoglobin significantly abolished the stimulatory effects of both NMDA and SNP on ACh release. In addition, superoxide anion scavengers such as superoxide dismutase and ceruloplasmin significantly reduced the increased ACh release evoked by NMDA and SNP. Synthesized peroxynitrite dose-dependently elevated the release of ACh. These results indicate that the increased release of ACh by NMDA and SNP is mediated through peroxynitrite formed in the reaction of superoxide anion with nitric oxide produced by NMDA receptor activation and liberated from SNP rather than nitric oxide itself.

Participation of peroxynitrite in acetylcholine release induced by nitric oxide generators

Peroxynitrite is a product produced by spontaneous reaction of nitric oxide (NO) with superoxide. Functional roles of peroxynitrite in the release of endogenous acetylcholine evoked by NO generators has been examined using primary-cultured cerebral cortical neurons. NO generators, such as sodium nitroprusside and S-nitroso-N-acetylpenicillamine, dose-dependently increased the release of acetylcholine (ACh); such increase of the release was significantly suppressed by hemoglobin which has the capacity to abolish biological effects of NO. Two types of superoxide scavengers, Cu2+, Zn2+ superoxide dismutase and ceruloplasmin, significantly reduced the NO-evoked ACh release. These results indicate that NO requires superoxide to evoke the release of ACh. Synthesized peroxynitrite evoked the release of ACh from cerebral cortical neurons in a dose-dependent manner. Thus, it is indicated that the NO-evoked ACh release is mediated, at least in part, by peroxynitrite produced by the reaction of NO with superoxide.