Lipidomics Profiling Reveals Serum Phospholipids Associated with Albuminuria in Early Type 2 Diabetic Kidney Disease.

Early screening and administration of DKD are beneficial for renal outcomes of type 2 diabetic patients. However, the current early diagnosis using the albuminuria/creatine ratio (ACR) contains limitations. This study aimed to compare serum lipidome variation between type 2 diabetes and early DKD patients with increased albuminuria through an untargeted lipidomics method to explore the potential lipid biomarkers for DKD identification. 92 type 2 diabetic patients were enrolled and divided into two groups: DM group (ACR < 3 mg/mmol, n = 49) and early DKD group (3 mg/mmol ≤ ACR < 30 mg/mmol, n = 43). Fasting serum was analyzed through an ultraperformance liquid mass spectrometry tandem chromatography system (LC-MS). Orthogonal partial least-squares discriminant analysis (OPLS-DA) and univariate and multivariate analysis were performed to filter differentially depressed lipids. Receiver operating characteristic (ROC) curves were used to estimate the diagnostic capability of potential lipid biomarkers. We found that serum phospholipids including phosphatidylserine (PS), sphingomyelin (SM), and phosphatidylcholine (PC) were significantly upregulated in the DKD group and were highly correlated with the ACR. In addition, a panel of two phospholipids including PS(27:0)-H and PS(30:2e)-H showed good performance to help clinical lipids in early DKD identification, which increased the area under the curve (AUC) from 0.568 to 0.954. The study exhibited the serum lipidome variation in early DKD patients, and the increased phospholipids might participate in the development of albuminuria. The panel of PS(27:0)-H and PS(30:2e)-H could be a potential biomarker for DKD diagnosis.

Self-Reported Insufficient Sleep Is Associated With Clinical and Inflammatory Features of Asthma: A Prospective Cohort Study.

BACKGROUND: A few studies have explored the association between short sleep duration and worse asthma outcomes in patients with self-reported asthma; however, all of them were cross-sectional. OBJECTIVES: To investigate the association between self-reported sleep duration and asthma-related clinical and inflammatory characteristics and whether sleep duration is associated with asthma exacerbations (AEs) in the following year. METHODS: A prospective cohort study consecutively recruited participants with asthma, who were classified into short (n = 58), normal (n = 380), and long (n = 84) sleep duration groups. We investigated the clinical and inflammatory characteristics and exacerbations within a 1-year follow-up. RESULTS: Patients with short sleep duration were older and had significantly lower total IgE and FeNO levels and higher airway inflammation, characterized by increased levels of IL-6 and TNF-α in sputum than those of patients with normal sleep duration. Furthermore, they had a significantly increased risk for poorly controlled asthma (adjusted odds ratio = 2.741; 95% CI, 1.379-5.447; P = .004) and moderate to severe AEs (adjusted incidence rate ratio = 1.798; 95% CI, 1.098-2.942; P = .020). CONCLUSIONS: Short sleep duration was associated with non-type 2 inflammation and is an independent risk factor for future AEs. Therefore, as a potentially treatable trait, sleep duration may have clinical implications for asthma management.

Reduced bronchodilator reversibility correlates with non-type 2 high asthma and future exacerbations: A prospective cohort study.

BACKGROUND: Given that airway obstruction in asthma is not always fully reversible, reduced bronchodilator reversibility (BDR) may be a special asthma phenotype. OBJECTIVE: To explore the characteristics of BDRhigh/low phenotypes (defined using two BDR criteria) and their associations with asthma exacerbations (AEs). METHODS: After baseline assessments, all patients were classified into BDRhigh or BDRlow phenotypes. This study consisted of 2 parts. Part I was a 12-month prospective observational cohort study designed to identify the clinical characteristics and associations with future AEs in BDRhigh/low phenotypes (n = 456). Part II, designed as a post hoc analysis of the data obtained in Part I, was conducted to assess the association between BDRhigh/low phenotypes and treatment responsiveness (n = 360). RESULTS: Subjects with BDRlow phenotypes had better baseline asthma symptom control and was negatively associated with eosinophilic asthma and type 2 (T2) high asthma. During the 12-month follow-up, those with BDRlow phenotypes had a higher risk of severe AEs (SAEs) (guideline-based criterion: RRadj = 2.24, 95% CI = [1.25, 3.68]; Ward's criterion: RRadj = 2.46, 95% CI = [1.40, 4.00]) and moderate-to-severe AEs (MSAEs) (guideline-based criterion: RRadj = 1.83, 95% CI = [1.22, 2.56]; Ward's criterion: RRadj = 1.94, 95% CI = [1.32, 2.68]) in the following year according to logistic regression models. Similar findings were obtained with negative binominal regression models. BDRlow phenotype was a risk factor for an insensitive response to anti-asthma treatment (guideline-based criterion: ORadj = 1.96, 95% CI = [1.05, 3.65]; Ward's criterion: ORadj = 2.01, 95% CI = [1.12, 3.58]). CONCLUSION: We identified that BDRlow phenotype was associated with non-T2 high asthma and future AEs. These findings have clinically relevant implications for asthma management.

Elevated Serum Uric Acid Increases the Risk of Ischemic Stroke Recurrence and Its Inflammatory Mechanism in Older Adults.

Background: Serum uric acid (UA) has been reported to be associated with ischemic stroke and inflammation. However, whether or not UA is related to the recurrence of ischemic stroke, and whether inflammation plays a role in the relationship between them remain inconclusive. Objective: We sought to explore the relationship between UA and the recurrence of ischemic stroke and to define the role of neutrophil-to-lymphocyte ratio (NLR) in the aforementioned relationship. Methods: A total of 8,995 patients were included in this study. Basic information and blood samples were collected, and whether or not each participant experienced ischemic stroke recurrence within 3 years was documented. Patients were stratified into three groups according to their UA level, as follows: ≤ 266, 267-339, and ≥ 340 µmol/L. COX regression and restricted cubic spline regression models were used to evaluate the clinical correlation between UA and ischemic stroke recurrence, mediation analysis and interaction and joint analysis were used to evaluate the role of NLR in the association of UA and ischemic stroke recurrence, and sensitivity and subgroup analyses were performed to test the robustness of the data. Results: Ischemic stroke recurrence was related to male sex, older age, higher UA level, higher NLR, hypertension, diabetes, and cardiovascular disease. Following adjustment for potential confounders, a high level of UA (≥ 340 µmol/L) increased the risk of recurrence by 92.6% in patients with previous ischemic stroke. We also found that NLR affects the association between UA and the recurrence of ischemic stroke in older adults, suggesting that patients with high NLR and high UA levels are at greater risk for ischemic stroke recurrence. Conclusion: UA level is non-linearly associated with recurrence, and NLR has an additive interaction between UA and ischemic stroke recurrence.

Individual and joint effects of trehalose and glutamate on diabetic retinopathy: a propensity score-matched case-control study.

Although previous studies demonstrate that trehalose can help maintain glucose homeostasis in healthy humans, its role and joint effect with glutamate on diabetic retinopathy (DR) remain unclear. We aimed to comprehensively quantify the associations of trehalose and glutamate with DR. This study included 69 pairs of DR and matched type 2 diabetic (T2D) patients. Serum trehalose and glutamate were determined via ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry system. Covariates were collected by a standardized questionnaire, clinical examinations and laboratory assessments. Individual and joint association of trehalose and glutamate with DR were quantified by multiple conditional logistic regression models. The adjusted odds of DR averagely decreased by 86% (odds ratio (OR): 0.14; 95% CI: 0.06, 0.33) with per interquartile range increase of trehalose. Comparing with the lowest quartile, adjusted OR (95% CI) were 0.20 (0.05, 0.83), 0.14 (0.03, 0.63) and 0.01 (<0.01, 0.05) for participants in the second, third and fourth quartiles of trehalose, respectively. In addition, as compared to their counterparts, T2D patients with lower trehalose (

Treatable Traits in Elderly Asthmatics from the Australasian Severe Asthma Network: A Prospective Cohort Study.

BACKGROUND: Data on treatable traits (TTs) in different populations are limited. OBJECTIVE: To assess TTs in elderly patients with asthma and compare them to younger patients, to evaluate the association of TTs with future exacerbations, and to develop an exacerbation prediction model. METHODS: We consecutively recruited 521 participants at West China Hospital, Sichuan University based on the Australasian Severe Asthma Network, classified as elderly (n = 62) and nonelderly (n = 459). Participants underwent a multidimensional assessment to characterize the TTs and were then followed up for 12 months. TTs and their relationship with future exacerbations were described. Based on the TTs and asthma control levels, an exacerbation prediction model was developed, and the overall performance was externally validated in an independent cohort. RESULTS: A total of 38 TTs were assessed. Elderly patients with asthma had more chronic metabolic diseases, fixed airflow limitation, emphysema, and neutrophilic inflammation, whereas nonelderly patients with asthma exhibited more allergic characteristics and psychiatric diseases. Nine traits were associated with increased future exacerbations, of which exacerbation prone, upper respiratory infection-induced asthma attack, cardiovascular disease, diabetes, and depression were the strongest. A model including exacerbation prone, psychiatric disease, cardiovascular disease, upper respiratory infection-induced asthma attack, noneosinophilic inflammation, cachexia, food allergy, and asthma control was developed to predict exacerbation risk and showed good performance. CONCLUSIONS: TTs can be systematically assessed in elderly patients with asthma, some of which are associated with future exacerbations, proving their clinical utility of evaluating them. A model based on TTs can be used to predict exacerbation risk in people with asthma.

[Survey of Online Outpatient Clinic Usage Experiences and Analysis of Factors Influencing Retreatment].

BACKGROUND: Because of the COVID-19 epidemic, people are mostly isolated at home and must seek medical advice over the internet. In addition, government authorities are currently investing greater efforts in developing internet hospitals. PURPOSE: The purpose of this essay was to assess how outpatients feel about online outpatient clinics and to analyze the factors that affect their satisfaction and willingness to return to these clinics. The results provide advice regarding how to more effectively encourage patients to use online outpatient clinics. METHODS: A self-developed questionnaire was used to survey 191 patients who had visited the online outpatient clinic of a tertiary hospital in Sichuan Province from January to July 2019. A descriptive analysis was conducted on the collected data, and factors influencing satisfaction were identified. RESULTS: The majority of the surveyed patients were young or middle-aged (92.7%) and 42.9% held a college degree or higher. Nearly three-quarters (72.2%) expressed feeling satisfied or better with the online outpatient clinic, with 31.4% of these expressing feeling very satisfied. Nearly all (91.1%) expressed the opinion that the online outpatient clinic had improved their awareness of health self-management . Furthermore, 176 (92.1%) were willing to use the online outpatient clinic again. The results of univariate analysis showed that the main factors negatively influencing re-use of the online outpatient clinic were: failure to solve the problem in a timely manner (χ2 = 8.603, p = .045), the complicated process of online registration (χ2 = 8.322, p = .016), the failure of the online physical examination (χ2 = 8.958, p = .015), and unreliable quality (χ2 = 15.373, p = .004). CONCLUSIONS: The participants surveyed in this study reported a lower satisfaction for their online outpatient clinic experience than reported in similar surveys of traditional outpatient services. However, many reported that their health-related self-management awareness had improved after use, indicating that they feel better about the online outpatient clinic. The factors that affected willingness to reuse to the online outpatient clinic related mainly to imperfections related to the clinic and its inability to adequately meet patient needs. Online outpatient clinics should simplify the process of registration, improve functions, and increase service functions such as online examination appointments and follow-up visits to improve patient satisfaction.

Association of n-6 PUFAs with the risk of diabetic retinopathy in diabetic patients.

Diabetic retinopathy (DR), the most common microvascular complication of diabetes and leading cause of visual impairment in adults worldwide, is suggested to be linked to abnormal lipid metabolism. The present study aims to comprehensively investigate the relationship between n-6 polyunsaturated fatty acids (PUFAs) and DR. This was a propensity score matching based case-control study, including 69 pairs of DR patients and type 2 diabetic patients without DR with mean age of 56.7 ± 9.2 years. Five n-6 PUFAs were determined by UPLC-ESI-MS/MS system. Principle component regression (PCR) and multiple conditional logistic regression models were used to investigate the association of DR risk with n-6 PUFAs depending on independent training and testing sets, respectively. According to locally weighted regression model, we observed obvious negative correlation between levels of five n-6 PUFAs (linoleic acid, γ-linolenic acid, eicosadienoic acid, dihomo-γ-linolenic acid and arachidonicacid) and DR. Based on multiple PCR model, we also observed significant negative association between the five n-6 PUFAs and DR with adjusted OR (95% CI) as 0.62 (0.43,0.87). When being evaluated depending on the testing set, the association was still existed, and PCR model had excellent classification performance, in which area under the curve (AUC) was 0.88 (95% CI: 0.78, 0.99). In addition, the model also had valid calibration with a non-significant Hosmer-Lemeshow Chi-square of 9.44 (P = 0.307) in the testing set. n-6 PUFAs were inversely associated with the presence of DR, and the principle component could be potential indicator in distinguishing DR from other T2D patients.

Correlations between age, biomedical variables, and cognition in patients with schizophrenia.

OBJECTIVE: To illustrate the influence of clinical variables on cognition performance in patients with schizophrenia (SCZ). METHODS: Using the 66nao Brain Training device (a novel measurement tool), the cognitive performance of 99 patients with SCZ was evaluated. Patients were diagnosed by the ICD-10 diagnostic criteria for SCZ, and their age were 16-68 years old. Furthermore, we explored the relationship between age, biomedical variables and specific cognitive domains in patients with SCZ. Patients were divided into two groups: various of cognitive domains impairment group and non-impairment group according to the norm scores. All data were analyzed using RStudio Version 1.0.44 (RStudio, Inc.). RESULTS: Patients with SCZ had obvious cognitive impairment in total and five subdomains of cognitive function. We found that 1) SCZ patients with impaired cognitive total score experienced significant older age and longer illness duration compared with those with normal cognitive total score. 2) SCZ patients with impaired memory experienced significant older age compared with those with normal memory. 3) SCZ patients with impaired attention showed significant lower serum triglyceride (TG) level compared with those with normal attention. 4) SCZ patients with impaired flexibility performed significant longer illness duration compared with those with normal flexibility. 5) SCZ patients with impaired cognitive agility performed significant older age, longer duration, and higher systolic blood pressure (SBP) compared with those with normal cognitive agility. 6) The age, illness duration and SBP in patients with impaired time perception were marginally different from those of subjects with normal time perception. CONCLUSION: There are five dimensions (memory, attention, flexibility, cognitive agility, and time perception) of cognitive dysfunction in SCZ patients. Age, illness duration, TG, and SBP might play vital roles in various subdomains of the cognitive deficits respectively in patients with SCZ.

The AAA-ATPase MIDASIN 1 Functions in Ribosome Biogenesis and Is Essential for Embryo and Root Development.

Ribosome biogenesis is an orchestrated process that relies on many assembly factors. The AAA-ATPase Midasin 1 (Mdn1) functions as a ribosome assembly factor in yeast (Saccharomyces cerevisiae), but the roles of MDN1 in Arabidopsis (Arabidopsis thaliana) are poorly understood. Here, we showed that the Arabidopsis null mutant of MDN1 is embryo-lethal. Using the weak mutant mdn1-1, which maintains viability, we found that MDN1 is critical for the regular pattern of auxin maxima in the globular embryo and functions in root meristem maintenance. By detecting the subcellular distribution of ribosome proteins, we noted that mdn1-1 impairs nuclear export of the pre-60S ribosomal particle. The processing of ribosomal precusor RNAs, including 35S, 27SB, and 20S, is also affected in this mutant. MDN1 physically interacts with PESCADILLO2 (PES2), an essential assembly factor of the 60S ribosome, and the observed mislocalization of PES2 in mdn1-1 further implied that MDN1 plays an indispensable role in 60S ribosome biogenesis. Therefore, the observed hypersensitivity of mdn1-1 to a eukaryotic translation inhibitor and high-sugar conditions might be associated with the defect in ribosome biogenesis. Overall, this work establishes a role of Arabidopsis MDN1 in ribosome biogenesis, which agrees with its roles in embryogenesis and root development.

A role of GUNs-Involved retrograde signaling in regulating Acetyl-CoA carboxylase 2 in Arabidopsis.

In Arabidopsis thaliana (Arabidopsis), Acetyl-CoA Carboxylase 2 (ACC2) is a nuclear DNA-encoded and plastid-targeted enzyme that catalyzes the conversion of acetyl-CoA to malonyl-CoA. ACC2 improves plant growth and development when chloroplast translation is impaired. However, little is known about the upstream signals that regulate ACC2. Here, through analyzing the transcriptome changes in brz-insensitive-pale green (bpg) 2-2, a pale-green mutant with impaired chloroplast gene expression resulting from loss of the BPG2 function, we found that the level of ACC2 was significantly up-regulated. Through performing genetic analysis, we further demonstrated that loss of the GENOMES UNCOUPLED 1 (GUN1) or GUN5 function partly perturbed the up-regulation of ACC2 in the bpg2-2 mutant, whereas ABA INSENSITIVE 4 (ABI4)-function-loss had no clear effect on the ACC2 expression. Furthermore, when plants were treated with plastid translation inhibitors, such as lincomycin and spectinomycin, the ACC2 transcriptional level was also markedly increased in a GUN-dependent manner. In conclusion, our results suggested that the GUN-involved plastid-to-nucleus retrograde communication played a role in regulating ACC2 in Arabidopsis.

Online Appointment Scheduling for a Nuclear Medicine Department in a Chinese Hospital.

Nuclear medicine, a subspecialty of radiology, plays an important role in proper diagnosis and timely treatment. Multiple resources, especially short-lived radiopharmaceuticals involved in the process of nuclear medical examination, constitute a unique problem in appointment scheduling. Aiming at achieving scientific and reasonable appointment scheduling in the West China Hospital (WCH), a typical class A tertiary hospital in China, we developed an online appointment scheduling algorithm based on an offline nonlinear integer programming model which considers multiresources allocation, the time window constraints imposed by short-lived radiopharmaceuticals, and the stochastic nature of the patient requests when scheduling patients. A series of experiments are conducted to show the effectiveness of the proposed strategy based on data provided by the WCH. The results show that the examination amount increases by 29.76% compared with the current one with a significant increase in the resource utilization and timely rate. Besides, it also has a high stability for stochastic factors and bears the advantage of convenient and economic operation.

Preoperative platelet-albumin-bilirubin grades predict the prognosis of patients with hepatitis B virus-related hepatocellular carcinoma after liver resection: A retrospective study.

Minimal information is available concerning platelet-albumin-bilirubin (PALBI) grades in patients with hepatocellular carcinoma (HCC) following liver resection. This study aimed to investigate the predictive ability of PALBI grades in patients with a Child-Pugh class A score and hepatitis B virus-related (HBV-related) HCC after liver resection.The data of patients with HBV-related HCC who underwent liver resection from 2010 to 2017 at our center were reviewed (n = 785). Cox regression was used to determine factors independently associated with postoperative recurrence and mortality. The area under the receiver operating characteristic curve (AUC) was used to estimate the predictive accuracy of different tools.During the follow-up period, 505 (64.3%) patients experienced recurrence, and 374 (47.6%) patients died. Multivariate analysis revealed that the tumor-node-metastasis (TNM) stage (HR = 1.591, 95%CI = 1.414-1.789, P < .001), PALBI grade (HR = 1.326, 95%CI = 1.139-1.544, P < .001), a high AFP level (HR = 1.382, 95%CI = 1.158-1.649, P < .001) and transfusion (HR = 1.364, 95%CI = 1.087-1.712, P = 0.007) were independently associated with recurrence. Additionally, microvascular invasion (HR = 1.674, 95%CI = 1.292-2.169, P < .001), beyond the Milan criteria (HR = 0.477, 95%CI = 0.346-0.657, P < .001), PALBI grade (HR = 1.356, 95%CI = 1.151-1.598, P < .001), a high AFP level (HR = 1.542, 95%CI = 1.252-1.900, P < .001), and transfusion (HR = 1.548, 95%CI = 1.199-1.999, P = 0.001) adversely impacted the overall survival. The AUCs of the PALBI grades for postoperative recurrence and mortality were significantly higher than the albumin-bilirubin grade and Child-Pugh score. The prognostic significance of the PALBI grade for postoperative recurrence and mortality was maintained when stratified by the TNM stage.The preoperative PALBI grade is a surrogate marker for the postoperative prognosis in patients with HBV-related HCC after liver resection.

Pharmacokinetics of silybin nanoparticles in mice bearing SKOV-3 human ovarian carcinoma xenocraft.

The particle fabrication technique was used to fabricate monodisperse size and shape specific poly (lactide-co-glycolide) particles loaded with the silybin. Response surface methodology (RSM) using the central composite rotatable design (CCRD) model was used to optimize formulations of silybin nanoparticles. Further the optimized nanoparticles are characterized for particle size, zeta potential, surface morphology, entrapment efficiency, in-vitro drug release, silybin availability for tumor, plasma, lung, spleen, liver were determined. The significant findings were the optimal formulation of PLGA concentration 10 mg, PVA concentration 2000 and PET width of 6 gave rise to the EE of 88%, mean diameter of 223 nm and zeta potential of 25-mV. Release studies were investigated at pH 1.2 and pH 6.8. It was studied that lower the pH, faster the release of sylibin. The nanoparticles had~15-fold higher plasma exposure as measured by AUC contrasted to pure silybin. The nanoparticles had a 60% increase altogether tumor silybin presentation contrasted with pure silybin. Nanoparticles had higher silybin presentation in the spleen and liver contrasted with pure silybin suspension as expected for a nanoparticle formulation. The lung silybin presentation for the nanoparticle was additionally 2-fold higher than that of the pure silybin suspension. The results of pharmacokinetic parameters and oral bioavailability data exhibited that drug-nanoparticle complex could enhance the oral absorption of silybin and as well as the use of particles with smaller feature size may be preferred to decrease clearance by organs of the mononuclear phagocyte system.

Microinjection of l-glutamate into the nucleus ambiguus partially inhibits gastric motility through the NMDA receptor - nitric oxide pathway.

We have previously reported that both l-glutamate (l-Glu) and nitric oxide (NO) modulate gastric motility in the nucleus ambiguus (NA). The aim of this study is to explore the potential correlation between the l-Glu and NO. A latex balloon connected to a pressure transducer was inserted into the pylorus through the fundus of anesthetized male Wistar rats to continuously record changes in gastric smooth muscle contractile curves. Pretreatment with the NO-synthase inhibitor N-nitro-l-arginine methylester (l-NAME) did not completely abolish the inhibitory effect of l-Glu on gastric motility, but intravenous injection of the ganglionic blocker hexamethonium bromide (Hb) did. By using a specific N-methyl-d-aspartic acid (NMDA) receptor antagonist, we blocked the inhibitory effect of the NO-donor sodium nitroprusside (SNP) on gastric motility. These results suggest that microinjections of l-Glu into the NA inhibits gastric motility by activating the cholinergic preganglionic neurons, partially through the NMDA receptor - NO pathway.

[Complications with peripherally inserted central catheters - observations and nursing experiences at one medical center in Chengdu].

Its peripheral vein puncture point, safe insertion procedure and high rate of success have made the peripherally inserted central catheter (PICC) a particularly suitable medical device for cancer patients who require long-term intravenous chemotherapy. PICC can help avoid the pain of repeat punctures as well as reduce incidence of cytotoxic drug extravasation-induced phlebitis and tissue necrosis. With PICC, patient activity is not limited, which improves quality of life. This paper reported on complications and subsequent nursing care provided to 400 cancer patients who received PICC in our center between September 2007 and October 2008. A total of 395 cases had successful PICC insertion on the first attempt and 5 cases achieved success immediately following the second insertion attempt (overall success rate: 98.8%). The average catheter dwell-in time was 122 days (range 2-350 days), during which time no patient required repeat puncture. During the insertion process, arrhythmia occurred in 1.5% (6/400), difficult catheter propelling in 3.75% (15/400), and excessive oozing of blood in 0.3% (1/400) of subjects. During the catheter dwell-in period, sensitizing dermatitis occurred in 8% (38/400), mechanical phlebitis in 7.5% (30/400), catheter occlusion in 9.5% (38/400) (including 2% [8/400] complete and 7.5% [30/400] partial occlusions), catheter associated hematogenous infection in 3% (12/400) and venous thrombosis in 2% (8/400) of subjects. All complications were well controlled with active and effective management. In conclusion, the safety of PICC can be maximized and complications reduced when nurses fully evaluate patients prior to their operation, strictly adhere to PICC operating guidelines, detect complications early, and manage problems promptly.

Effects and mechanisms of L-glutamate microinjected into nucleus ambiguus on gastric motility in rats.

BACKGROUND: L-glutamate (L-GLU) is a major neurotransmitter in the nucleus ambiguus (NA), which can modulate respiration, arterial pressure, heart rate, etc. This study investigated the effects and mechanisms of L-GLU microinjected into NA on gastric motility in rats. METHODS: A latex balloon connected with a pressure transducer was inserted into the pylorus through the forestomach for continuous recording of the gastric motility. The total amplitude, total duration, and motility index of gastric contraction waves within 5 minutes before microinjection and after microinjection were measured. RESULTS: L-GLU (5 nmol, 10 nmol and 20 nmol in 50 nl normal saline (PS) respectively) microinjected into the right NA significantly inhibited gastric motility, while microinjection of physiological saline at the same position and the same volume did not change the gastric motility. The inhibitory effect was blocked by D-2-amino-5-phophonovalerate (D-AP5, 5 nmol, in 50 nl PS), the specific N-methyl-D-aspartic acid (NMDA) receptor antagonist, but was not influenced by 6-cyaon-7-nitroquinoxaline-2,3-(1H,4H)-dione (CNQX) (5 nmol, in 50 nl PS), the non-NMDA ionotropic receptor antagonist. Bilateral subdiaphragmatic vagotomy abolished the inhibitory effect by microinjection of L-GLU into NA. CONCLUSIONS: Microinjection of L-GLU into NA inhibits the gastric motility through specific NMDA receptor activity, not non-NMDA receptor activity, and the efferent pathway is the vagal nerves.

Hindbrain Effects of L-Glutamate on Gastric Motility in Rats.

BACKGROUND: There are no unanimous standpoints about the dorsal motor nucleus of the vagus (DMV) and nucleus of solitary tract (NTS) involving in the regulation of gastric motility up to now. METHODS: In this study, we injected L-Glutamate (L-Glu), an incitant neurotransmitter in the central neural system, into DMV and NTS to further investigate the effects of the two nuclei on gastric motility. A latex balloon connected with a pressure transducer was inserted into the pylorus through the fundus for continuous recording of the change of gastric smooth muscle contractile curves. RESULTS: L-Glu (10 nmol in 0.1 µl) microinjected into right DMV and NTS significantly inhibited gastric motility. We compared the effects of L-Glu (10 nmol) microinjected into the two nuclei, the L-Glu microinjected into right NTS had the greater inhibitory effect on gastric motility than microinjected into the right DMV. The physiological saline microinjection evoked no significant effect on gastric motility. CONCLUSIONS: L-Glu microinjected into right DMV and NTS evoked significant inhibition on gastric motility in rats. At equal dose of L-Glu, NTS had the greater inhibitory effect than DMV.