Clinical effects and mechanisms of a Chinese patent medicine, Tongxinluo capsule, as an adjuvant treatment in coronary heart disease.

Coronary heart disease (CHD) is the leading cause of death globally, posing a serious threat to human health. However, the current treatment approaches available for CHD fall short of the ideal results. Tongxinluo (TXL) is a traditional Chinese medicine (TCM) that has been employed in the clinical treatment of cardiovascular and cerebrovascular diseases (such as angina pectoris, stroke, etc.) in China for many years and holds great potential as a prospective treatment. TXL either as a standalone treatment or in combination with interventions recommended in CHD guidelines has been shown to be effective and well tolerated in clinical trials for CHD. Drawing on the evidence from clinical trials and experimental studies, this review will focus on the cardiovascular protective properties and related mechanisms of TXL. By searching 8 Chinese and English databases, more than 4000 articles were retrieved. These articles were categorized, then read, and finally written into this review. In this review, the pharmacological properties of TXL include regulation of blood lipids, improvement of endothelial function, anti-inflammatory, antioxidant, inhibition of apoptosis and regulation of autophagy, anti-fibrosis, promotion of angiogenesis, and modulation of exosome communication. The information provided in this review will help the reader to comprehend better the insights that TCM has developed over time in practice and provide new perspectives for the treatment of CHD.

Exploration of rich-club reorganization in facial synkinesis: insights from structural and functional brain network analysis.

Facial palsy therapies based on cortical plasticity are in development, but facial synkinesis progress is limited. Studying neural plasticity characteristics, especially network organization and its constitutive elements (nodes/edges), is the key to overcome the bottleneck. We studied 55 participants (33 facial synkinesis patients, 22 healthy controls) with clinical assessments, functional magnetic resonance imaging (fMRI), and diffusion tensor imaging (DTI). We analyzed rich-club organization and metrics of structural brain networks (rich-club coefficients, strength, degree, density, and efficiency). Functional brain network metrics, including functional connectivity and its coupling with the structural network, were also computed. Patients displayed reduced strength and density of rich-club nodes and edges, as well as decreased global efficiency. All nodes exhibited decreased nodal efficiency in patients. Patients had significantly increased functional connectivity and decreased structural-functional coupling strength in rich-club nodes, rich-club edges, and feeder edges. Our study indicates that facial synkinesis patients have weakened structural connections but enhanced functional transmission from rich-club nodes. The loss of connections and efficiency in structural network may trigger compensatory increases in functional connectivity of rich-club nodes. Two potential biomarkers, rich-club edge density and structural-functional coupling strength, may serve as indicators of disease outcome. These findings provide valuable insights into synkinesis mechanisms and offer potential targets for cortical intervention.

Changing epidemiology of hepatocellular carcinoma in Asia.

Liver cancer is the fifth most common cancer and the second leading cause of malignant death in Asia, and Asia reports 72.5% of the world's cases in 2020. As the most common histological type, hepatocellular carcinoma (HCC) accounts for the majority of incidence and mortality of liver cancer cases. This review presents the changing epidemiology of HCC in Asian countries in recent years. Globally, aged, male and Asian populations remain the group with the highest risk of HCC. Hepatitis B virus (HBV) and hepatitis C virus (HCV) are still the leading risk factors of HCC with a slight decline in most Asian countries, which is mainly attributed to HBV vaccination of newborns, prevention of HCV horizontal transmission and treatment of chronic hepatitis. However, the prevalence of HCC caused by metabolic factors, including metabolic syndrome, obesity and non-alcoholic fatty liver diseases, is increasing rapidly in Asian countries, which may eventually become the major cause of HCC. Excessive alcohol consumption continues to be an important risk factor as the average consumption of alcohol is still growing. Hopefully, great effort has been made to better prevention and treatment of HCC in most Asian regions, which significantly prolongs the survival of HCC patients. Asian countries tend to use more aggressive intervention than European and American countries, but it remains unclear whether this preference is related to a better prognosis. In conclusion, HCC remains a major disease burden in Asia, and the management of HCC should be adjusted dynamically based on the changing epidemiology.

Study on the Effect of Antiplatelet and Gastric Mucosal Protection of Traditional Chinese Medicine Invigorating Qi and Hemostasis.

BACKGROUND: To investigate the effects of Chinese herbal medicine in tonifying qi and attaining hemostasis caused by the metabolism of the drug clopidogrel and as a result of platelet and gastric mucosa injury in an ischemia-reperfusion rat model. METHODS: A pharmacokinetic model was established to record the drug metabolism parameters of clopidogrel metabolites. Then, absorption of the drug was compared with approaches using the traditional Chinese medicine (TCM) approach of tonifying qi and establishing hemostasis, to using the drug pantoprazole and applying these approaches in combination with clopidogrel. Intragastric administration was performed, and all indicators were tested. RESULTS: The area under the curve (AUC; 0-T, 300.342 ± 35.832 mg/L* h; AUC 0-∞, 320.462 ± 40.213 mg/L* h), the plasma peak concentration (30.622 ± 9.917 mg/L*), and the peak time and half-life (7.954 ± 1.121 h) in the clopidogrel and the TCM groups were higher than those in the clopidogrel and pantoprazole groups. In terms of antiplatelet aggregation, compared with model group, the platelet aggregation rate induced by arachidonic acid (AA) and adenosine diphosphate (ADP) was significantly decreased by the TCM approach of tonifying qi and stopping bleeding (p < 0.05). The ADP, thromboxane A2, GPII B/Pa-A, CD62P and platelet factor 4 content in the TCM yiqi decoction and hemostasis approach were significantly decreased (p < 0.01). Compared with the clopidogrel group, the gastrin and motilin in the serum, the cyclooxygenase (COX)-1 and prostaglandin E2 in gastric tissue, and expression of vascular endothelial growth factor messenger ribonucleic acid in the serum were all significantly increased using TCM approach to protect against gastric mucosal injury (p < 0.05). CONCLUSION: TCM invigorating qi and hemostasis has an inhibitory effect on platelet activation. It can reduce the local inflammatory reaction at the same time as protecting gastric mucosa.

Tai Chi for health and well-being: A bibliometric analysis of published clinical studies between 2010 and 2020.

The objective of this bibliometric review was to identify the volume, breadth, and characteristics of clinical studies evaluating Tai Chi published between January 2010 and January 2020. Five English and four Chinese language databases were searched. Following independent screening, 1018 eligible publications representing 987 studies were identified, which was a three-fold increase from the previous decade. Most common were randomized controlled trials (548/987, 55.5 %), followed by systematic reviews (157/987, 15.9 %), non-randomized controlled clinical studies (152/987, 15.4 %), case series (127/987, 12.9 %) and case reports (3/987, 0.3 %) that were conducted in China (730/987, 74.0 %), followed by the United States of America (123/987, 12.5 %) and South Korea (20/987, 2.0 %). Study participants were mostly in the adult (55.2 %) and/or older adult (72.0 %) age groups. The top ten diseases/conditions were hypertension, chronic obstructive pulmonary disease, diabetes, knee osteoarthritis, heart failure, depression, osteoporosis/osteopenia, breast cancer, coronary heart disease and insomnia. A quarter of the studies enrolled healthy participants to evaluate the effects of Tai Chi on health promotion/preservation, balance/falls, and physiological/biomechanical outcomes. Yang style Tai Chi was the most popular, followed by Chen and Sun style. Tai Chi was mostly commonly delivered face-to-face by a Tai Chi instructor in group settings for 60 min, three times a week, for 12 weeks. Most studies (93.8 %) reported at least one outcome in favor of Tai Chi. Adverse events were underreported (7.2 %). Over half fell short of expected intervention reporting standards, signalling the need for Tai Chi extensions to existing guidelines.

Systemic Therapy for Hepatocellular Carcinoma: Advances and Hopes.

The majority of patients with hepatocellular carcinoma (HCC) are diagnosed at an advanced stage that can only benefit from systemic treatments. Although HCC is highly treatmentresistant, significant achievements have been made in the molecular targeted therapy and immunotherapy of HCC. In addition to regorafenib, cabozantinib and ramucirumab were approved for the second- line targeted treatment by the FDA after disease progression on sorafenib. Nivolumab failed to demonstrate remarkable benefit in overall survival (OS) as first-line therapy, while pembrolizumab did not achieve pre-specified statistical significance in both OS and progression-free survival (PFS) as second-line treatment. Combinations of targeted agents, immune checkpoint inhibitors and other interventions showed favorable results. In this review, we summarized the progress of systemic therapy in HCC and discussed the future directions of the treatment of HCC.

Diffusional plasticity induced by electroacupuncture intervention in rat model of peripheral nerve injury.

Electroacupuncture (EA) is an adjuvant therapy for peripheral nerve injury (PNI). Both peripheral and central alterations contribute to the rehabilitation process. We employed diffusion tensor imaging (DTI) to investigate the diffusion plasticity of afferent and efferent pathways caused by EA in model of peripheral nerve injury and reparation. Twenty-four rats were divided into three groups: normal group, model group and intervention group. Rats of the model group and the intervention group underwent sciatic nerve transection and anastomosis. EA intervention was performed on the intervention group at ST-36 and GB-30 for three months. Gait assessment and DTI were conducted at days post-operative (DPO) 30, 60 and 90. We selected corticospinal tract, spinothalamic tract and internal capsule as regions of interest and analyzed diffusion metrics including fractional anisotropy (FA), axial diffusivity (AD) and radial diffusivity (RD). FA values and RD values displayed significant differences or obvious tendency while AD values maintained a stable level. RD values displayed better indicative performance than FA in internal capsule. The intervention group presented significant correlation between RD values and Regularity Index (RI) during the intervention period. The effect of EA on peripheral nerve injury repairing rats appeared to be accelerated recovery process of sensory and motor neural pathway. We proposed that RD was a potential in vivo indicator for structural plasticity caused by EA and PNI.

The efficacy of homemade tolcapone in the treatment of patients with Parkinsons disease.

The aim of the study was to investigate the efficacy of homemade tolcapone in treatment of patients with Parkinson's disease (PD). Eighty patients with PD were subjected to randomized, double-blind, placebo-controlled and parallel-group study. PD patients were randomly divided into the tolcapone treatment group (41 cases) and placebo group (39 cases). Each patient received 1 pill of tolcapone or placebo, 3 times per day for 26 weeks. Efficacy was evaluated using the internationally used unified Parkinson's disease rating scale (UPDRS) scoring system for PD symptoms. After the treatment for 26 weeks, the cognitive function, tremor, muscle stiffness, voluntary movement and autonomic nerve symptoms were compared between the two groups using UPDRS scores. Compared with the placebo group, cognitive function, muscle stiffness and voluntary movement reduction were significantly improved in patients of the tolcapone group (P<0.05). However, no significant differences in UPDRS scores of autonomic nerve symptoms and tremor were found between two groups after treatment (P>0.05). Tolcapone, a catechol-O-methyl transferase (COMT) inhibitor, can improve the motor function of patients with PD, especially exercise and muscle stiffness. Tolcapone can also improve the cognitive function of patients.

Genetics of Parkinson's disease and related disorders.

Parkinson's disease (PD) is a complex and heterogeneous neurological condition characterised mainly by bradykinesia, resting tremor, rigidity and postural instability, symptoms that together comprise the parkinsonian syndrome. Non-motor symptoms preceding and following clinical onset are also helpful diagnostic markers revealing a widespread and progressive pathology. Many other neurological conditions also include parkinsonism as primary or secondary symptom, confounding their diagnosis and treatment. Although overall disease course and end-stage pathological examination single out these conditions, the significant overlaps suggest that they are part of a continuous disease spectrum. Recent genetic discoveries support this idea because mutations in a few genes (α-synuclein, LRRK2, tau) can cause partially overlapping pathologies. Additionally, mutations in causative genes and environmental toxins identify protein homeostasis and the mitochondria as key mediators of degeneration of dopaminergic circuits in the basal ganglia. The evolving mechanistic insight into the pathophysiology of PD and related conditions will contribute to the development of targeted and effective symptomatic treatments into disease-modifying therapies that will reduce the burden of these dreadful conditions.

Efficacy and Safety of Intravenous Thrombolysis for the Treatment of Acute Ischemic Stroke Patients with Saccular Intracranial Aneurysms of ≤3 mm.

To explore the effectiveness and safety of intravenous thrombolysis (IVT) using recombinant tissue plasminogen activator in treating acute ischemic stroke patients with concomitant intracranial aneurysms (IA) of ≤3 mm. Clinical data of patients who were treated in Tianjin Huanhu Hospital from June 2012 to September 2013 were retrospectively analyzed. Patients were divided into the following groups: (a) IVT group, in which there were 30 acute ischemic stroke patients with IA of ≤3 mm and 30 patients without aneurysms; and (b) IA group, in which there were 30 patients who did not receive IVT and 30 patients who received IVT. The incidence of intracranial hemorrhage, case-fatality, and good outcome rate was compared within these two groups. Inside the IVT group, the incidence of systematic intracranial hemorrhage and case-fatality showed no significant differences between patients with concomitant IA and those without IA. The 3-month good outcome rate was also not significantly different (24 [80.0 %] vs. 27 [90 %]; P = 0.278). In IA group, patients who had received IVT showed significantly superior good outcome rate than those who had not received IVT (24 [80.0 %] vs. 16 [53.3 %]; P = 0.028).The incidence of intracranial hemorrhage and case-fatality rate were not significantly different between these two subgroups as well. IVT is effective and safe method for the treatment of acute ischemic stroke patients with saccular IA of ≤3 mm.

Use of Intravenous Thrombolytic Therapy in Acute Ischemic Stroke Patients: Evaluation of Clinical Outcomes.

The use of intravenous thrombolytic therapy (ITT) in acute ischemic stroke (AIS) patients is still debated in China. We present the analysis of clinico-demographic retrospective data of 646 AIS patients that were treated by alteplase ITT at our hospital. The data collected included age, gender, education, income, drug use before disease onset, and awareness of stroke/ITT. The risk factors studied were hypertension, diabetes, hyperlipidemia, atrial fibrillation, coronary heart disease, cerebral infarction, transient ischemic attack, valvular heart disease, thyroid disease, migraine, asymptomatic carotid stenosis, family history of stroke, hyperhomocysteinemia, smoking, drinking, and gingivitis. Pre-ITT patient data included blood pressure and time from onset to hospital. Post-ITT patient data included National Institutes of Health Stroke Scale (NIHSS) scores, clinical outcome, revascularization, hemorrhage, healing rate, and 90-day mortality. Hospital management information included monthly ITT cases, discharges, bed turnaround times, length of hospital stay, bed utilization, drug ratio, massive cerebral infarction decompressive craniectomy, and social impact. Prognosis evaluation was based on post-ITT NIHSS and modified Rankin Scale (mRS) scores. We found that ITT success rate was 75.85 %, with a bleeding rate of 1.55 % and a 90-day mortality rate of 2.01 %. Overall, the data suggest that the ITT therapy was highly successful in AIS patients treated at our hospital.

Safety and Effectiveness of Intravenous Thrombolysis with Recombinant Tissue Plasminogen Activator in 80 Years and Older Acute Ischemic Stroke Patients.

This study aims to explore the safety and efficacy of intravenous thrombolysis (IVT) with recombinant tissue plasminogen activator (rt-PA) in elderly (≥80 years old) acute ischemic stroke (AIS) patients. The clinical data of patients who were treated in Tianjin Huanhu Hospital from June 2012 to November 2013 were retrospectively analyzed; among them, 404 patients had received IVT with rt-PA and 200 patients had not received IVT. Among ≥80-year-old patients, 204 had received IVT and 200 had not. And the 404 patients who had received IVT were divided into two subgroups: elderly (≥80 years of age; n = 204) and controls (<80 years old; n = 200). The incidence of intracranial hemorrhage (ICH) and symptomatic intracranial hemorrhage, case fatality rate, and other prognostic indicators were compared. Among all ≥80-year-old patients, the IVT subgroup had significantly superior good outcome rates than the non-IVT subgroup at 24-h and 3-month along with significantly lower case fatality rate. But for the patients those who had received IVT, the incidence of ICH and the 7-day case fatality rate were not significantly increased in both the elderly and control subgroups. The 24-h and 3-month good outcome rates were not significantly different between these two subgroups as well. IVT with rt-PA is a safe and effective treatment for ≥80-year-old AIS patients.

The Relationship between Visual Field Global Indices and Retinal Nerve Fiber Layer Thickness in Healthy Myopes.

The aim of the current study was to investigate the association between the thickness of the retinal nerve fiber layer (RNFL) and central visual field indices in otherwise healthy myopes. In total, 57 otherwise healthy subjects were cross-sectionally studied. General ophthalmic examinations, refractive measurements, RNFL thickness by spectral domain optical coherence tomography (OCT), and central visual fields were examined. Linear models were used to assess the associations. In this young and mid-aged population, the mean spherical equivalent was -4.79 (SD 1.66) and -4.59 (SD 1.88) diopters in the right and left eyes, respectively. Approximately 7% to 14% of the eyes showed the average RNFL thickness out of the normal range. The temporal RNFL was remarkably thicker, whereas the nasal RNFL was thinner. The higher the refractive error, the thinner the RNFL thickness. A thicker overall RNFL was significantly associated with decreased mean sensitivity and increased mean defect, and further adjustments for age, sex, refractive error, optic disk area, or ocular magnification did not change the association. Although nonpathologic myopia does not significantly affect central visual field global indices, its effects on the RNFL may be linked with performance on the central visual field test.

Aberration changes of the corneal anterior surface following discontinued use of rigid gas permeable contact lenses.

AIM: To record aberrations with a corneal topographic device on the anterior surface of the cornea at different time-points prior to wearing and following discontinued use of rigid gas permeable (RGP) contact lenses. The effect of wearing RGP on the anterior surface of the cornea was discussed to provide guidance for clinical refractive error correction. METHODS: The study objects were 24 eyes from 24 patients. All patients underwent identical examination procedures prior to lens use, as well as afterwards, including slit-lamp examination, non-contact tonometer measurement, computer optometry and corneal curvature measurement, subjective refraction test, and corneal topography analysis. The patients wore contact lenses everyday for 1 month and then discontinued. Corneal topographies were recorded at certain time points of 30 minutes, 1 day, 3, 7 and 14 days following use. RESULTS: Total corneal aberration at each time point following discontinued use of RGP contact lenses was less than the time point prior to use. Detailed results were as follows: root mean square (RMS) (pre)=(1.438±0.328)µm, RMS (30 minutes)=(1.076±0.355)µm, RMS (1 day)=(1.362±0.402)µm, RMS (3 days)=(1.373±0.398)µm, RMS (7 days)=(1.387±0.415)µm, and RMS (14 days)=(1.430±0.423)µm. Results showed that at 30 minutes after discontinued use of RGP contact lenses, almost all 2(nd)- and 3(rd)-order aberrations change. Quadrafoil Z10 and spherical Z12 of the 4(th)-order were also changed. Alterations to Z5, Z6, and Z12 at 1 day after discontinued use were significant differences compared with the time period prior to RGP use: Z5 and Z6 decreased, and Z12 increased slightly. Z5 and Z6 remained decreased at 3 days after discontinued use, but Z9 and Z10 continued to increase and Z12 returned to levels prior to RGP use. At 14 days after discontinued use, all aberrations were not significantly different from the values prior to use. CONCLUSION: The use RGP contact lenses greatly reduced total aberration of the anterior surface of the cornea. Changes to 2(nd)- and 3(rd)-order aberrations (including Z3, Z4, Z5, Z6, Z7, and Z8) were more significant. Following discontinued use of RGP contact lenses, the majority of lower order aberrations returned to original levels in a short period of time. During this process, a transient higher order aberration appeared, but all changes disappeared within 14 days after discontinued use of RGP contact lenses.

[Analysis of aberration changes of the corneal anterior surface following discontinued use of rigid gas permeable contact lenses].

OBJECTIVE: The present study used a corneal topographic device to record aberrations on the anterior surface of the cornea at different time-points prior to wearing and following discontinued use of rigid gas permeable (RGP) contact lenses. The effect of wearing RGPCL on the anterior surface of the cornea was discussed to provide guidance for clinical refractive error correction. METHODS: The study objects were 60 eyes from 30 patients. All patients underwent identical examination procedures prior to lens use, as well as afterwards, including slit-lamp examination, non-contact tonometer measurement, computer optometry & corneal curvature measurement, subjective refraction test, and corneal topography analysis. The patients wore contact lenses every day for 1 month and then discontinued. Corneal topographies were recorded at certain time points of 30 min, 1 day, 3 days, 1 week, and 2 weeks following use. RESULTS: Total corneal aberration at each time point following discontinued use of RGP contact lenses was less than the time point prior to use. Detailed results are as follows; root mean square (RMS) (pre) = (1.438 ± 0.328), RMS (30 min) = (1.076 ± 0.355), RMS (1 day) = (1.362 ± 0.402), RMS (3 day) = (1.373 ± 0.398), RMS (7 day) = (1.387 ± 0.415), and RMS (14 day) = (1.448 ± 0.423). Results showed that at 30 minutes after discontinued use of RGP contact lenses, almost all 2(nd)- and 3(rd)-order aberrations were altered. Quadrafoil Z10 and spherical Z12 of the 4(th)-order were also changed. Alterations to Z5, Z6, and Z12 at 1 day after discontinued use were significant compared with the time period prior to RGP use: Z5 and Z6 decreased, and Z12 increased slightly (F = 2.869 ∼ 5.549, P = 0.001 ∼ 0.042). Z5 and Z6 remained decreased at 3 days after discontinued use, but Z9 and Z10 continued to increase and Z12 returned to levels prior to RGP use (P > 0.05). At 2 weeks after discontinued use, all aberrations were not significantly different from the values prior to use (P > 0.05). CONCLUSIONS: The use RGP contact lenses greatly reduced total aberration of the anterior surface of the cornea. Changes to 2(nd)- and 3(rd)-order aberrations (including Z3, Z4, Z5, Z6, Z7, and Z8) were more significant. Following discontinued use of RGP contact lenses, the majority of lower order aberrations returned to original levels in a short period of time. During this process, a transient higher order aberration appeared, but all changes disappeared within 2 weeks after discontinued use of RGP contact lenses.

[Application of molecular marker techniques in taxonomic identification of parasites].

Different subspecies or strains of the same species produce varied clinical manifestations. The clarification of parasite taxonomy is useful for the researches of their biology, epidemiology and control. DNA molecular markers have the advantages of high polymorphism, non-pleiotropy, and clear identifying alleles, etc. This paper summarizes the first generation (restriction fragment length polymorphism, random amplified polymorphic DNA), second generation (simple sequence repeat-anchored PCR, inter-simple sequence repeat) and third generation (single nucleotide polymorphism) molecular marker techniques, and their application in taxonomic identification of parasites.

Expression and localization of activin receptor-interacting protein 2 in mouse tissues.

Activin plays important roles in reproductive tissues as a stimulator of follicle-stimulating hormone (FSH) secretion. Activin receptor-interacting protein 2 (ARIP2) has been recently identified in mouse tissues as a regulatory protein of activin signal transduction. However, the localization and function of ARIP2 are not well characterized. In this study, we found that ARIP2 mRNA and protein were widely expressed in mouse tissues by reverse transcription-PCR (RT-PCR) and Western blotting. The immunoreactivities of ARIP2 were mainly localized at myocardial cells of heart, Leydig cells in testis, macrophages and epithelial cells of bronchus in lung, renal tubule and collecting tubule, pancreatic islet, adrenal gland, adenohypophysis and hypothalamus by immunohistochemical staining. Furthermore, ARIP2 overexpression down-regulated signal transduction induced by activin A in pituitary gonadotroph LbetaT2 cells and inhibited FSH secretion from primary cultured anterior pituitary cells induced by activin A. These findings suggest that ARIP2 is widely distributed in various tissues and may be a negative regulator of activin action in pituitary cells.

Effect of GNTI, a kappa opioid receptor antagonist, on MK-801-induced hyperlocomotion and stereotypy in mice.

AIM: To examine the effect of GNTI [5'-guanidinyl-17-(cyclopropylmethyl)-6,7- dehydro-4,5alpha-epoxy-3,14-dihydroxy-6,7-2',3'-indolomorphinan], a selective antagonist for the kappa opioid receptor, in the MK-801 (dizocilpine maleate)-induced behavioral model of psychosis in schizophrenia as a way to explore the involvement of the kappa opioid receptor in modulating psychotic symptoms of schizophrenia. METHODS: Two doses of MK-801 (0.3 mg/kg and 0.6 mg/kg) were administered by systemic injection in mice to induce psychosis-like behavior as a rodent schizophrenia model, preceded by an injection of different doses of GNTI. Both locomotion and stereotypy were measured as the behavioral endpoints for quantitative analysis. RESULTS: GNTI inhibited MK-801-induced hyperlocomotion and stereotypy. In particular, GNTI showed differential modulation of stereotypy induced by 0.3 mg/kg vs 0.6 mg/kg MK-801. CONCLUSION: Antagonism of kappa opioid receptors attenuates MK-801-induced behavior, suggesting a potential involvement of the kappa opioid receptor in psychosis-like symptoms of schizophrenia. GNTI appears to be a useful pharmacological tool to explore the kappa opioid receptor function in vivo.