A yeast-based system to study SARS-CoV-2 Mpro structure and to identify nirmatrelvir resistant mutations

The SARS-CoV-2 main protease (Mpro) is a major therapeutic target. The Mpro inhibitor, nirmatrelvir, is the antiviral component of Paxlovid, an orally available treatment for COVID-19. As Mpro inhibitor use increases, drug resistant mutations will likely emerge. We have established a non-pathogenic system, in which yeast growth serves as a proxy for Mpro activity, enabling rapid identification of mutants with altered enzymatic activity and drug sensitivity. The E166 residue is known to be a potential hot spot for drug resistance and yeast assays showed that an E166R substitution conferred strong nirmatrelvir resistance while an E166N mutation compromised activity. On the other hand, N142A and P132H mutations caused little to no change in drug response and activity. Standard enzymatic assays confirmed the yeast results. In turn, we solved the structures of Mpro E166R, and Mpro E166N, providing insights into how arginine may drive drug resistance while asparagine leads to reduced activity. The work presented here will help characterize novel resistant variants of Mpro that may arise as Mpro antivirals become more widely used.

Naturally occurring mutations of SARS-CoV-2 main protease confer drug resistance to nirmatrelvir

The SARS-CoV-2 main protease (Mpro) is the drug target of Pfizers oral drug Paxlovid. The emergence of SARS-CoV-2 variants with mutations in Mpro raised the alarm of potential drug resistance. In this study, we identified 100 naturally occurring Mpro mutations located at the nirmatrelvir binding site, among which 20 mutants, including S144M/F/A/G/Y, M165T, E166G, H172Q/F, and Q192T/S/L/A/I/P/H/V/W/C/F, showed comparable enzymatic activity to the wild-type (kcat/Km <10-fold change) and resistance to nirmatrelvir (Ki >10-fold increase). X-ray crystal structures were determined for seven representative mutants with and/or without GC-376/nirmatrelvir. Viral growth assay showed that Mpro mutants with reduced enzymatic activity led to attenuated viral replication. Overall, our study identified several drug resistant hot spots that warrant close monitoring for possible clinical evidence of Paxlovid resistance. One Sentence SummaryPaxlovid resistant SARS-CoV-2 viruses with mutations in the main protease have been identified from clinical isolates.

The P132H mutation in the main protease of Omicron SARS-CoV-2 decreases thermal stability without compromising catalysis or small-molecule drug inhibition

The ongoing SARS-CoV-2 pandemic continues to be a significant threat to global health. First reported in November 2021, the Omicron variant (B.1.1.529) is more transmissible and can evade immunity better than previous SARS-CoV-2 variants, fueling an unprecedented surge in cases. To produce functional proteins from this polyprotein, SARS-CoV-2 relies on the cysteine proteases Nsp3/papain-like protease (PLpro) and Nsp5/Main Protease (Mpro)/3C-like protease to cleave at three and more than 11 sites, respectively.1 Therefore, Mpro and PLpro inhibitors are considered to be some of the most promising SARS-CoV-2 antivirals. On December 22, 2021, the Food and Drug Administration (FDA) issued an Emergency Use Authorization (EUA) for PAXLOVID, a ritonavir-boosted formulation of nirmatrelvir. Nirmatrelvir is a first-in-class orally bioavailable SARS-CoV-2 Mpro inhibitor.2 Thus, the scientific community must vigilantly monitor potential mechanisms of drug resistance, especially because SARS-CoV-2 is naive to Mpro inhibitors. Mutations have been well identified in variants to this point.3 Notably, Omicron Mpro (OMpro) harbors a single mutation- P132H. In this study we characterize the enzymatic activity, drug inhibition, and structure of OMpro while evaluating the past and future implications of Mpro mutations.

Adverse reactions of linezolid in the treatment of multidrug-resistant pulmonary tuberculosis / 中华传染病杂志

Objective:To analyze the adverse reactions of patients with multidrug-resistant pulmonary tuberculosis treated with linezolid, and to provide reference for clinical rational use of drugs.Methods:A total of 189 patients with multidrug-resistant pulmonary tuberculosis who were admitted to Hunan Chest Hospital between June 2019 and June 2020 were retrospectively included, and were divided into the linezolid group and the control group. The control group was given a standardized anti-tuberculosis treatment without linezolid, and the linezolid group was given linezolid in addition to standardized regimens. The occurrences of hematological toxicity, peripheral neuritis, optic neuritis and other adverse reactions in the two groups after anti-tuberculosis treatment were recorded. The risk factors for adverse reactions of linezolid were analyzed. Statistical analysis was performed using independent samples t test and chi-square test, and logistic regression was used to analyze the risk factors for adverse reactions of linezolid. Results:A total of 189 patients with MDR-TB were included in this study, including 108 in the linezolid group and 81 in the control group. There were no significant differences in baseline characteristics between the linezolid and control groups. The frequencies of leukopenia, anemia, thrombocytopenia, peripheral neuritis and optic neuritis in the linezolid group were 20.4%(22/108), 47.2%(51/108), 21.3%(23/108), 20.4%(22/108) and 13.9%(15/108), respectively, which were all significantly higher than those in the control group (8.6%(7/81), 27.2%(22/81), 9.9%(8/81), 1.2%(1/81) and 4.9%(4/81), respectively), and the differences were all statistically significant ( χ2=4.90, 7.86, 4.40, 15.86 and 4.10, respectively, all P<0.050). Patients older than 45 years of age was independent risk factor for leukopenia (odds ratio ( OR)=3.08, 95% confidence interval ( CI) 1.03 to 9.25, P<0.050) and thrombocytopenia ( OR=2.41, 95% CI 1.09 to 5.35, P<0.050) after linezolid administration. The higher value of white blood cell at baseline ( OR=0.48, 95% CI 0.30 to 0.76, P=0.002) was an independent protective factor for leukopenia associated with linezolid. Conclusions:Pancytopenia, peripheral neuritis and optic neuritis are prone to appear when linezolid is used to treat patients with multidrug-resistant pulmonary tuberculosis. In clinical practice, closely monitoring the adverse reactions during the use of linezolid for anti-tuberculosis treatment is needed.

Brilacidin, a COVID-19 Drug Candidate, demonstrates broad-spectrum antiviral activity against human coronaviruses OC43, 229E and NL63 through targeting both the virus and the host cell

Brilacidin, a mimetic of host defense peptides (HDPs), is currently in phase 2 clinical trial as an antibiotic drug candidate. A recent study reported that brilacidin has antiviral activity against SARS-CoV-2 by inactivating the virus. In this work, we discovered an additional mechanism of action of brilacidin by targeting heparan sulfate proteoglycans (HSPGs) on host cell surface. Brilacidin, but not acetyl brilacidin, inhibits the entry of SARS-CoV-2 pseudovirus into multiple cell lines, and heparin, a HSPG mimetic, abolishes the inhibitory activity of brilacidin on SARS-CoV-2 pseudovirus cell entry. In addition, we found that brilacidin has broad-spectrum antiviral activity against multiple human coronaviruses (HCoVs) including HCoV-229E, HCoV-OC43, and HCoV-NL63. Mechanistic studies revealed that brilacidin has a dual antiviral mechanism of action including virucidal activity and binding to coronavirus attachment factor HSPGs on host cell surface. Brilacidin partially loses its antiviral activity when heparin was included in the cell cultures, supporting the host-targeting mechanism. Drug combination therapy showed that brilacidin has a strong synergistic effect with remdesivir against HCoV-OC43 in cell culture. Taken together, this study provides appealing findings for the translational potential of brilacidin as a broad-spectrum antiviral for coronaviruses including SARS-CoV-2.

Discovery of SARS-CoV-2 papain-like protease inhibitors through a combination of high-throughput screening and FlipGFP-based reporter assay

The papain-like protease (PLpro) of SARS-CoV-2 is a validated antiviral drug target. PLpro is involved in the cleavage of viral polyproteins and antagonizing host innate immune response through its deubiquitinating and deISG15ylating activities, rendering it a high profile antiviral drug target. Through a FRET-based high-throughput screening, several hits were identified as PLpro inhibitors with IC50 values at the single-digit micromolar range. Subsequent lead optimization led to potent inhibitors with IC50 values ranging from 0.56 to 0.90 {micro}M. To help prioritize lead compounds for the cellular antiviral assay against SARS-CoV-2, we developed the cell-based FlipGFP assay that is suitable for quantifying the intracellular enzymatic inhibition potency of PLpro inhibitors in the BSL-2 setting. Two compounds selected from the FlipGFP-PLpro assay, Jun9-53-2 and Jun9-72-2, inhibited SARS-CoV-2 replication in Caco-2 hACE2 cells with EC50 values of 8.89 and 8.32 {micro}M, respectively, which were 3-fold more potent than GRL0617 (EC50 = 25.1 {micro}M). The X-ray crystal structures of PLpro in complex with GRL0617 showed that binding of GRL0617 to SARS-CoV-2 induced a conformational change in the BL2 loop to the more closed conformation. Overall, the PLpro inhibitors identified in this study represent promising starting points for further development as SARS-CoV-2 antivirals, and FlipGFP-PLpro assay might be a suitable surrogate for screening PLpro inhibitors in the BSL-2 setting.

Current status of prevention and treatment of esophagogastric variceal bleeding in cirrhotic portal hypertension patients in Ningxia region: a multicenter study / 中华消化外科杂志

Objective:To investigate the current status of prevention and treatment of esophagogastric variceal bleeding (EVB) in cirrhotic portal hypertension patients in Ningxia region.Methods:The retrospective and descriptive study was conducted. The clinical data of 820 cirrhotic portal hypertension patients who were admitted to 21 medical centers in Niangxia region from January 2018 to December 2020 were collected, including 85 cases in Ningxia Hui Autonomous Region People′s Hospital, 73 cases in the Fifth People′s Hospital of Ningxia Hui Autonomous Region, 59 cases in the Wuzhong People′s Hospital, 52 cases in the Qingtongxia People′s Hospital, 50 cases in the Guyuan People′s Hospital, 47 cases in the Yuanzhou District People′s Hospital of Guyuan City, 47 cases in the Yinchuan Second People′s Hospital, 40 cases in the General Hospital of Ningxia Medical University, 40 cases in the Tongxin People′s Hospital, 35 cases in the Yinchuan First People′s Hospital, 34 cases in the Third People′s Hospital of Ningxia Hui Autonomous Region, 32 cases in the Zhongwei People′s Hospital, 30 cases in the Lingwu People′s Hospital, 30 cases in the Wuzhong New District Hospital, 30 cases in the Yanchi People′s Hospital, 29 cases in the Ningxia Hui Autonomous Region Academy of Traditional Chinese Medicine, 28 cases in the Shizuishan Second People′s Hospital, 25 cases in the Shizuishan First People′s Hospital, 21 cases in the Haiyuan People′s Hospital, 20 cases in the Pengyang People′s Hospital, 13 cases in the Longde People′s Hospital. There were 538 males and 282 females, aged (56±13)years. Observation indicators: (1) clinical charac-teristics of cirrhotic portal hypertension patients; (2) overall prevention and treatment of EVB in cirrhotic portal hypertension patients; (3) prevention and treatment of EVB in cirrhotic portal hypertension patients from different grade hospitals. Measurement data with normal distribution were represented as Mean± SD. Count data were described as absolute numbers, and comparison between groups was analyzed using the chi-square test. Results:(1) Clinical characteristics of cirrhotic portal hypertension patients: of 820 cirrhotic portal hypertension patients, 271 cases were in compensated stage and 549 cases were in decompensated stage. Of the 271 cases in compensated stage, there were 183 maels and 88 females, aged (53±12)years. There were 185 Han people, 85 Hui people and 1 case of other ethic group. The etiological data of liver cirrhosis showed 211 cases of viral hepatitis B, 4 cases of alcoholic liver disease, 8 cases of viral hepatitis C, and 48 cases of other etiology. There were 235 cases of Child-Pugh grade A and 36 cases lack of data. Of the 549 cases in decompensated stage, there were 355 males and 194 females, aged (57±14) years. There were 373 Han people, 174 Hui people and 2 cases of other ethic group. The etiological data of liver cirrhosis showed 392 cases of viral hepatitis B, 33 cases of alcoholic liver disease, 10 cases of viral hepatitis C, and 114 cases of other etiology. There were 80 cases of Child-Pugh grade A, 289 cases of grade B, 170 cases of grade C and 10 cases lack of data. (2) Overall prevention and treatment of EVB in cirrhotic portal hypertension patients: of 271 patients in compensated stage, 38 cases received non-selective β-blocker (NSBB) therapy, 16 cases received endoscopic treatment, 6 cases received interventional therapy. Of 549 patients in decompensated stage, 68 cases received NSBB therapy, 46 cases received endoscopic treatment, 28 cases received interventional therapy. (3) Prevention and treatment of EVB in cirrhotic portal hypertension patients from different grade hospitals: of 271 patients in compensated stage, 181 cases came from tertiary hospitals, of which 28 cases received NSBB therapy, 15 cases received endoscopic treatment, 6 cases received interventional therapy. Ninety cases came from secondary hospitals, of which 10 cases received NSBB therapy, 1 cases received endoscopic treatment. There was no significant difference in NSBB for prevention of EVB between tertiary and secondary hospitals ( χ2=0.947, P>0.05), while there was a significant difference in endoscopic treatment for prevention of EVB between tertiary and secondary hospitals ( χ2=5.572, P<0.05). Of 549 patients in decompensated stage, 309 cases came from tertiary hospitals, of which 22 cases received NSBB therapy, 29 cases received endoscopic treatment, 22 cases received interventional therapy. Two hundreds and fourty cases came from secondary hospitals, of which 46 cases received NSBB therapy, 17 cases received endoscopic treatment, 6 cases received interven-tional therapy. There were significant differences in NSBB and interventional therapy for prevention of EVB between tertiary and secondary hospitals ( χ2=18.065, 5.956, P<0.05). Conclusions:The proportion of receiving EUB prevention in cirrhotic portal hypertension in Ningxia is relatively low. For patients with compensated liver cirrhosis, the proportion of NSBB therapy and endoscopic treatment in the secondary hospitals was lower than that in tertiary hospitals. For patients with decompensated liver cirrhosis, the proportion of interventional treatment in secondary hospitals is lower than that of tertiary hospitals, but the proportion of NSBB in secondary hospitals taking is higher than that of tertiary hospitals.

An expedited approach towards the rationale design of non-covalent SARS-CoV-2 main protease inhibitors with in vitro antiviral activity

The main protease (Mpro) of SARS-CoV-2 is a validated antiviral drug target. Several Mpro inhibitors have been reported with potent enzymatic inhibition and cellular antiviral activity, including GC376, boceprevir, calpain inhibitors II and XII, each containing a reactive warhead that covalently modifies the catalytic Cys145. In this study, we report an expedited drug discovery approach by coupling structure-based design and Ugi four-component (Ugi-4CR) reaction methodology to the design of non-covalent Mpro inhibitors. The most potent compound 23R had cellular antiviral activity similar to covalent inhibitors such as GC376. Our designs were guided by overlaying the structure of SARS-CoV Mpro + ML188 (R), a non-covalent inhibitor derived from Ug-4CR, with the X-ray crystal structures of SARS-CoV-2 Mpro + calpain inhibitor XII/GC376/UAWJ247. Binding site analysis suggests a strategy of extending the P2 and P3 substitutions in ML188 (R) to achieve optimal shape complementary with SARS-CoV-2 Mpro. Lead optimization led to the discovery of 23R, which inhibits SARS-CoV-2 Mpro and SARS-CoV-2 viral replication with an IC50 of 0.31 M and EC50 of 1.27 M, respectively. The binding and specificity of 23R to SARS-CoV-2 Mpro were confirmed in a thermal shift assay and native mass spectrometry assay. The co-crystal structure of SARS-CoV-2 Mpro with 23R revealed the P2 biphenyl fits snuggly into the S2 pocket and the benzyl group in the -methylbenzyl faces towards the core of the enzyme, occupying a previously unexplored binding site located in between the S2 and S4 pockets. Overall, this study revealed the most potent non-covalent SARS-CoV-2 Mpro inhibitors reported to date and a novel binding pocket that can be explored for Mpro inhibitor design.

Boceprevir, calpain inhibitors II and XII, and GC-376 have broad-spectrum antiviral activity against coronaviruses in cell culture

As the COVID-19 pandemic continues to fold out, the morbidity and mortality are increasing daily. Effective treatment for SARS-CoV-2 is urgently needed. We recently discovered four SARS-CoV-2 main protease (Mpro) inhibitors including boceprevir, calpain inhibitors II and XII and GC-376 with potent antiviral activity against infectious SARS-CoV-2 in cell culture. Despite the weaker enzymatic inhibition of calpain inhibitors II and XII against Mpro compared to GC-376, calpain inhibitors II and XII had more potent cellular antiviral activity. This observation promoted us to hypothesize that the cellular antiviral activity of calpain inhibitors II and XII might also involve the inhibition of cathepsin L in addition to Mpro. To test this hypothesis, we tested calpain inhibitors II and XII in the SARS-CoV-2 pseudovirus neutralization assay in Vero E6 cells and found that both compounds significantly decreased pseudoviral particle entry into cells, indicating their role in inhibiting cathepsin L. The involvement of cathepsin L was further confirmed in the drug time-of-addition experiment. In addition, we found that these four compounds not only inhibit SARS-CoV-2, but also SARS-CoV, MERS-CoV, as well as human coronaviruses (CoVs) 229E, OC43, and NL63. The mechanism of action is through targeting the viral Mpro, which was supported by the thermal shift binding assay and enzymatic FRET assay. We further showed that these four compounds have additive antiviral effect when combined with remdesivir. Altogether, these results suggest that boceprevir, calpain inhibitors II and XII, and GC-376 are not only promising antiviral drug candidates against existing human coronaviruses, but also might work against future emerging CoVs.

Ebselen, disulfiram, carmofur, PX-12, tideglusib, and shikonin are non-specific promiscuous SARS-CoV-2 main protease inhibitors

There is an urgent need for vaccines and antiviral drugs to combat the COVID-19 pandemic. Encouraging progress has been made in developing antivirals targeting SARS-CoV-2, the etiological agent of COVID-19. Among the drug targets being investigated, the viral main protease (Mpro) is one of the most extensively studied drug targets. Mpro is a cysteine protease that hydrolyzes the viral polyprotein at more than 11 sites and it is highly conserved among coronaviruses. In addition, Mpro has a unique substrate preference for glutamine in the P1 position. Taken together, it appears that Mpro inhibitors can achieve both broad-spectrum antiviral activity and a high selectivity index. Structurally diverse compounds have been reported as Mpro inhibitors, with several of which also showed antiviral activity in cell culture. In this study, we investigated the mechanism of action of six previously reported Mpro inhibitors, ebselen, disulfiram, tideglusib, carmofur, shikonin, and PX-12 using a consortium of techniques including FRET-based enzymatic assay, thermal shift assay, native mass spectrometry, cellular antiviral assays, and molecular dynamics simulations. Collectively, the results showed that the inhibition of Mpro by these six compounds is non-specific and the inhibition is abolished or greatly reduced with the addition of reducing reagent DTT. In the absence of DTT, these six compounds not only inhibit Mpro, but also a panel of viral cysteine proteases including SARS-CoV-2 papain-like protease, the 2Apro and 3Cpro from enterovirus A71 (EV-A71) and EV-D68. However, none of the compounds inhibits the viral replication of EV-A71 or EV-D68, suggesting that the enzymatic inhibition potency IC50 values obtained in the absence of DTT cannot be used to faithfully predict their cellular antiviral activity. Overall, we provide compelling evidence suggesting that ebselen, disulfiram, tideglusib, carmofur, shikonin, and PX-12 are non-specific SARS-CoV-2 Mpro inhibitors, and urge the scientific community to be stringent with hit validation. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=92 SRC="FIGDIR/small/299164v1_ufig1.gif" ALT="Figure 1"> View larger version (13K): org.highwire.dtl.DTLVardef@1e68820org.highwire.dtl.DTLVardef@1f31c02org.highwire.dtl.DTLVardef@1b406e1org.highwire.dtl.DTLVardef@2fa8e8_HPS_FORMAT_FIGEXP M_FIG C_FIG

Structure and inhibition of the SARS-CoV-2 main protease reveals strategy for developing dual inhibitors against Mpro and cathepsin L

The main protease (Mpro) of SARS-CoV-2, the pathogen responsible for the COVID-19 pandemic, is a key antiviral drug target. While most SARS-CoV-2 Mpro inhibitors have a {gamma}-lactam glutamine surrogate at the P1 position, we recently discovered several Mpro inhibitors have hydrophobic moieties at the P1 site, including calpain inhibitors II/XII, which are also active against human cathepsin L, a host-protease that is important for viral entry. To determine the binding mode of these calpain inhibitors and establish a structure-activity relationship, we solved X-ray crystal structures of Mpro in complex with calpain inhibitors II and XII, and three analogues of GC-376, one of the most potent Mpro inhibitors in vitro. The structure of Mpro with calpain inhibitor II confirmed the S1 pocket of Mpro can accommodate a hydrophobic methionine side chain, challenging the idea that a hydrophilic residue is necessary at this position. Interestingly, the structure of calpain inhibitor XII revealed an unexpected, inverted binding pose where the P1 pyridine inserts in the S1 pocket and the P1 norvaline is positioned in the S1 pocket. The overall conformation is semi-helical, wrapping around the catalytic core, in contrast to the extended conformation of other peptidomimetic inhibitors. Additionally, the structures of three GC-376 analogues UAWJ246, UAWJ247, and UAWJ248 provide insight to the sidechain preference of the S1, S2, S3 and S4 pockets, and the superior cell-based activity of the aldehyde warhead compared with the -ketoamide. Taken together, the biochemical, computational, structural, and cellular data presented herein provide new directions for the development of Mpro inhibitors as SARS-CoV-2 antivirals.

Boceprevir, GC-376, and calpain inhibitors II, XII inhibit SARS-CoV-2 viral replication by targeting the viral main protease

A novel coronavirus SARS-CoV-2, also called novel coronavirus 2019 (nCoV-19), started to circulate among humans around December 2019, and it is now widespread as a global pandemic. The disease caused by SARS-CoV-2 virus is called COVID-19, which is highly contagious and has an overall mortality rate of 6.96% as of May 4, 2020. There is no vaccine or antiviral available for SARS-CoV-2. In this study, we report our discovery of inhibitors targeting the SARS-CoV-2 main protease (Mpro). Using the FRET-based enzymatic assay, several inhibitors including boceprevir, GC-376, and calpain inhibitors II, and XII were identified to have potent activity with single-digit to submicromolar IC50 values in the enzymatic assay. The mechanism of action of the hits was further characterized using enzyme kinetic studies, thermal shift binding assays, and native mass spectrometry. Significantly, four compounds (boceprevir, GC-376, calpain inhibitors II and XII) inhibit SARS-CoV-2 viral replication in cell culture with EC50 values ranging from 0.49 to 3.37 M. Notably, boceprevir, calpain inhibitors II and XII represent novel chemotypes that are distinct from known Mpro inhibitors. A complex crystal structure of SARS-CoV-2 Mpro with GC-376, determined at 2.15 [A] resolution with three monomers per asymmetric unit, revealed two unique binding configurations, shedding light on the molecular interactions and protein conformational flexibility underlying substrate and inhibitor binding by Mpro. Overall, the compounds identified herein provide promising starting points for the further development of SARS-CoV-2 therapeutics.

Fear memory and heart rate and blood pressure during conditioned fear in rats with hippocampal lesion or fimbria-fornix transection / 中华行为医学与脑科学杂志

Objective To investigate the effects of dorsal hippocampal lesions (DH) or fimbria-fornix transection (FF) on the learning and memory of conditioned fear and the heart rate and blood pressure in rats.Methods Nineteen male adult Wistar rats were used in this experiment.They were implanted telemetry sensors in their abdominal aortas.Two week later,six of the rats were subjected to permanent NMDA-induced neurotoxic lesions to the dorsal hippocampus (DH) and seven for the fimbria-fornix transection (FF)through stereotactic brain surgery,the left six were treated with saline as the control (Sham).All rats were subjected to a conditioned fear experiment.Meanwhile,changes in heart rate and blood pressure were measured.Results There was no significant difference in heart rate and blood pressure among the rats with the hippocampal operation or fimbria-fornix transection.In the acquisition of conditioned fear,there were significant difference in freezing time among the three group in both inter-trial-interval (ITI) and conditioned stimulus (CS) process (all P＜0.05).The freezing time of the FF group showed significantly lower than that of the Sham group (P＜0.05).There was no significant difference in heart rate and blood pressure among the three group(P＞0.05).In the test of conditioned contextual fear memory,the freezing time percentage in the FF group ((0.31±0.16) ％) significantly lower than that in the Sham group ((2.78± 1.23) ％) (P＜0.05)at the first 3 min of the test.There was a significant difference in heart rate among the three group.The heart rate of FF group ((436.42± 10.16) times/min) was significantly lower than that of the Sham group ((472.48±4.43) times/min,P＜0.01) and the DH group ((469.94 ±7.36)times/min,P＜0.01).In the test of conditioned tone fear memory.The freezing time percentage in FF group ((18.78±6.29) ％) was significantly lower than that in the Sham ((51.77±9.33)％,P＜0.01) and DH group ((59.19±8.13)％,P＜0.01),but the freezing time percentage between the later two groups had no difference (P=0.52).The synchronous telemetry measurement showed there was no significant difference both in the heart rate and the blood pressure among the groups (all P＞0.05) during the conditioned tone test.Conclusion The dorsal hippocampal lesions and fimbria-fornix transection in rats can significantly reduce the learning and memory ability in conditioned fear and scene fear in rats,and the effect of fimbria-fornix transection is more obvious.The decrease in,fear memory is not synchronously reflected in heart rate and blood pressure in rats.

Effect of Acupuncture plus Acupoint Injection on the Hyperhomocystinemia in the Convalescent Stage of Cerebral Infarction patients / 上海针灸杂志

Objective To observe the effect of acupuncture plus acupoint injection on the hyperhomocystinemia in the convalescent stage of cerebral infarction patients.Method A total of 120 patients in the convalescent stage of cerebral infarction with hyperhomocystinemia were randomized into group A, group B, and group C, 40 cases in each group. The three groups were intervened by conventional western medicine treatment and rehabilitation therapy, the group A was byXing Nao Kai Qiao acupuncture treatment in addition, the group B was by acupoint injection with cobamamide for injection and the group C was byXing Nao Kai Qiao acupuncture plus acupoint injection treatment. The change of the plasma homocysteine (HCY) level, the Barthel Index (BI) score and National Institutes of Health Stroke Scale (NIHSS) score were observed before and after treatment.ResultEach index(the HCY level, BI score and NIHSS score) in the three groups was significantly changed after treatment(P<0.01). Each index in the group C was significantly different from that in the group A and group B after treatment(P<0.05,P<0.01). The HCY level of the group B after the treatment was significantly different from that of the group A.Conclusion Acupuncture plus acupoint injection can significantly change the HCY level of the convalescent stage of cerebral infarction patients with hyperhomocystinemia, improve the activity of daily living and nerve function.