Soft granular particles sheared at a controlled volume: rate-dependent dynamics and the solid-fluid transition.

We study the responses of fluid-immersed soft hydrogel spheres that are sheared under controlled volume fractions. Slippery, deformable particles along with the density-matched interstitial fluid are sandwiched between two opposing rough cones, allowing studies for a wide range of volume fraction φ both above and below the jamming of granular suspension. We utilize sudden cessations of shearing, accompanied by refraction-matched internal imaging, to supplement the conventional flow-curve measurements. At sufficiently high volume fractions, the settling of particles after the cessations exhibits a continuous yet distinct transition over the change of the shear rate. Such changes back out the qualitative difference in the state of flowing prior to the cessations: the quasi-static yielding of a tightly packed network, as opposed to the rapid sliding of particles mediated by the interstitial fluid whose dynamics depends on the driving rate. In addition, we determine the solid-fluid transition using two independent methods: the extrapolation of stress residues and the estimated yield stress from high values of φ, and the settling of particles upon shear cessations as φ goes across the transition. We also verify the power law on values of characteristic stress with respect to the distance from jamming φ - φc, with an exponent close to 2. These results demonstrate a multitude of relaxation timescales behind the dynamics of soft particles, and raise questions on how we extend the existing paradigms of the flow of a densely packed system when the softness is actively involved.

[Study on improvement provided by water extracts of Polygoni Multiflori Radix and Polygoni Multiflori Radix Praeparata on non-alcoholic steatohepatitis in mice induced by MCD].

This study aims to observe the improvement of non-alcoholic steatohepatitis(NASH) after using water extracts of Polygoni Multiflori Radix and Polygoni Multiflori Radix Praeparata and explore their preliminary mechanism. Mice were fed with methionine-choline-deficent diet(MCD) for 6 weeks for modeling, and mice were orally given with 50, 100, 200 mg·kg~(-1) of Polygoni Multiflori Radix water extract(PMRWE) or Polygoni Multiflori Radix Praeparata water extract(PMRPWE) at the last 4 weeks. During the whole experimental procedure, the body weight changes of the mice were monitored and recorded. Serum alanine aminotransferase(ALT) and aspartate aminotransferase(AST) activities were detected; liver histopathological evaluation and NAFLD activity score(NAS) calculation were conducted, and the levels of reactive oxygen species(ROS) in liver tissues were analyzed. The contents of triglyceride(TG) and non-esterified fatty acids(NEFA) in liver tissues were detected, and oil red O staining of the liver tissues was conducted and observed. Quantitative polymerase chain reaction(qPCR) was used to detect hepatic mRNA expression of ß-oxidation-related genes in mice. The results showed that PMRWE(100, 200 mg·kg~(-1)) and PMRPWE(50, 100, 200 mg·kg~(-1)) alleviated liver damage in MCD-induced NASH in mice. PMRWE(100, 200 mg·kg~(-1)) and PMRPWE(50, 100, 200 mg·kg~(-1)) reduced hepatic li-pid accumulation in mice with NASH. Different doses of PMRPWE inversed the decreased hepatic mRNA expression of ß-oxidation-related genes in mice with NASH. This study indicated that PMRPWE and PMRWE could ameliorate MCD-induced NASH in mice by promoting fatty acid ß oxidation, reducing liver lipid accumulation, and alleviating liver damage. Moreover, the protective effect of PMRPWE against MCD-induced NASH was better than PMRWE.

Characterization of core-shell MOF particles by depth profiling experiments using on-line single particle mass spectrometry.

Materials with core-shell structures have distinct properties that lend themselves to a variety of potential applications. Characterization of small particle core-shell materials presents a unique analytical challenge. Herein, single particles of solid-state materials with core-shell structures were measured using on-line aerosol time-of-flight mass spectrometry (ATOFMS). Laser 'depth profiling' experiments verified the core-shell nature of two known core-shell particle configurations (<2 µm diameter) that possessed inverted, complimentary core-shell compositions (ZrO2@SiO2 versus SiO2@ZrO2). The average peak area ratios of Si and Zr ions were calculated to definitively show their core-shell composition. These ratio curves acted as a calibrant for an uncharacterized sample ­ a metal-organic framework (MOF) material surround by silica (UiO-66(Zr)@SiO2; UiO = University of Oslo). ATOFMS depth profiling was used to show that these particles did indeed exhibit a core-shell architecture. The results presented here show that ATOFMS can provide unique insights into core-shell solid-state materials with particle diameters between 0.2-3 µm.

An evaluation comparing Californium252 neutron brachytherapy with neoadjuvant intra-arterial embolism chemotherapy assisted surgery effect for treating advanced cervical carcinoma patients.

PURPOSE OF INVESTIGATION: To compare the therapeutic and side effects of using Californium252 (252Cf) neutron brachytherapy with neoadjuvant intra-arterial embolism chemotherapy in combination with surgery for treating Stage Ib2-IIb cervical cancers (CCs). MATERIALS AND METHODS: Thirty-two Stage Ib2-IIb CC patients were enrolled and randomly divided into two groups from January 2007 to April 2010 in the present Hospital. Prior to surgery within four weeks, a total of 17 cases were treated with 252Cf neutron brachytherapy (700-800 cGy doses at point A) once a week (Group A), and 15 cases were treated by neoadjuvant intra-arterial embolism chemotherapy using a combination of bleomycin, carboplatin, and cyclophosphamide twice (Group B). The clinical symptoms and signs, side effects, and relapse condition follow up until July 2013 were compared between the two groups for the perioperation. RESULTS: Reductions in tumor mass and CR+PR were not significantly different between the groups before the surgery (p > 0.05). Abdominal pain and pelvic adhesions were significantly more severe in Group B (p < 0.05). There were no significant differences in surgical time, blood loss or the other side effects between Groups A and B (p > 0.05). The percentage of pelvic tumor recurrences in Group A was lower than that of the patients in Group B (11.8% vs 20.0%) although with no significant difference at present. No distant metastasis has been found in both two groups. CONCLUSION: Except for less abdominal pain and pelvic adhesions, 252Cf neutron brachytherapy has perioperative effects similar to those of neoadjuvant intra-arterial embolism chemotherapy.

[A multiscale carotid plaque detection method based on two-stage analysis].

OBJECTIVE: To develop a method for accurate identification of multiscale carotid plaques in ultrasound images. METHODS: We proposed a two-stage carotid plaque detection method based on deep convolutional neural network (SM-YOLO).A series of algorithms such as median filtering, histogram equalization, and Gamma transformation were used to preprocess the dataset to improve image quality. In the first stage of the model construction, a candidate plaque set was built based on the YOLOX_l target detection network, using multiscale image training and multiscale image prediction strategies to accommodate carotid artery plaques of different shapes and sizes. In the second stage, the Histogram of Oriented Gradient (HOG) features and Local Binary Pattern (LBP) features were extracted and fused, and a Support Vector Machine (SVM) classifier was used to screen the candidate plaque set to obtain the final detection results. This model was compared quantitatively and visually with several target detection models (YOLOX_l, SSD, EfficientDet, YOLOV5_l, Faster R-CNN). RESULTS: SM-YOLO achieved a recall of 89.44%, an accuracy of 90.96%, a F1-Score of 90.19%, and an AP of 92.70% on the test set, outperforming other models in all performance indicators and visual effects. The constructed model had a much shorter detection time than the Faster R-CNN model (only one third of that of the latter), thus meeting the requirements of real-time detection. CONCLUSION: The proposed carotid artery plaque detection method has good performance for accurate identification of carotid plaques in ultrasound images.

Leptin levels in human and rodent: measurement of plasma leptin and ob RNA in obese and weight-reduced subjects.

Leptin, the gene product of the obese gene, may play an important role in regulating body weight by signalling the size of the adipose tissue mass. Plasma leptin was found to be highly correlated with body mass index (BMI) in rodents and in 87 lean and obese humans. In humans, there was variability in plasma leptin at each BMI suggesting that there are differences in its secretion rate from fat. Weight loss due to food restriction was associated with a decrease in plasma leptin in samples from mice and obese humans.

The validity of ICD-11 PTSD and Complex PTSD in East Asian cultures: findings with young adults from China, Hong Kong, Japan, and Taiwan.

Background: The ICD-11 classifies posttraumatic stress disorder (PTSD) and complex PTSD (CPTSD) as two distinct diagnoses. Few studies have tested the validity of ICD-11 CPTSD in non-Western settings, particularly in Asia. Objective: This study assessed the factorial, concurrent, and discriminant validity of CPTSD symptoms with four samples of young adults from mainland China, Hong Kong, Japan, and Taiwan. Method: Young adults aged 18-24 years were recruited by convenience sampling and provided their data anonymously online. Study measures included the International Trauma Questionnaire (ITQ) to measure PTSD and CPTSD, and measures of childhood adversity, depression, anxiety, age, and sex. Confirmatory factor analysis (CFA) was performed for each sample to evaluate the validity of two CPTSD measurement models. Structural equation modelling (SEM) was used to determine the multivariate associations between study variables for the full sample. Results: A total of 1,346 young adults completed the survey. CFA showed both models of CPTSD examined fit the data well across all four samples. SEM findings showed that number of childhood adversities significantly associated with both PTSD and CPTSD factors; depression significantly associated with CPTSD factors but not PTSD, whereas anxiety significantly associated with both. Conclusions: Study findings provide evidence for PTSD and CPTSD as separate and valid diagnoses in Asia. More cross-cultural comparisons are needed to understand whether risks for either condition differ by geographical or sociocultural norms.

Antecedentes: La CIE-11 clasifica el trastorno de estrés postraumático (TEPT) y el trastorno de estrés postraumático complejo (TEPT-C) como dos diagnósticos distintos. Pocos estudios han probado la validez del TEPT-C de la CIE-11 en escenarios no occidentales, particularmente en Asia.Objetivo: Este estudio evaluó la validez factorial, concurrente y discriminante de los síntomas de TEPT-C de 4 muestras de adultos jóvenes de China continental, Hong Kong, Japón y Taiwán.Método: Fueron reclutados adultos jóvenes entre 18 y 24 años de edad a través de una muestra por conveniencia y proveyeron sus datos en forma anónima en línea. Las mediciones del estudio incluyeron el Cuestionario Internacional de Trauma (ITQ por sus siglas en inglés) para medir TEPT y TEPT-C y mediciones de adversidad en la infancia, depresión, ansiedad, edad y sexo. Se realizó el análisis factorial confirmatorio (CFA por sus siglas en inglés) para cada muestra para evaluar la validez de los dos modelos de medición de TEPT-C. Se usó el modelado de ecuaciones estructurales (SEM por sus siglas en inglés) para determinar las asociaciones multivariadas entre las variables del estudio para la muestra completa.Resultados: un total de 1.346 adultos jóvenes completaron la encuesta. La CFA mostró que ambos modelos de TEPT-C examinados se ajustan bien los datos en las cuatro muestras. Los hallazgos del SEM mostraron que el número de adversidades en la infancia se asociaba significativamente tanto con los factores de TEPT y TEPT-C; la depresión se asociaba significativamente para TEPT-C pero no para TEPT; mientras que la ansiedad se asociaba significativamente con ambos.Conclusiones: los hallazgos del estudio proveen evidencia para TEPT y TEPT-C como dos diagnósticos separados y válidos en Asia. Se necesitan más comparaciones transculturales para comprender si los riesgos de cualquiera de estas condiciones difieren geográficamente o por normas socioculturales.

IL-1beta caused pancreatic beta-cells apoptosis is mediated in part by endoplasmic reticulum stress via the induction of endoplasmic reticulum Ca2+ release through the c-Jun N-terminal kinase pathway.

Endoplasmic reticulum (ER) homeostasis is crucial for beta-cell function and survival. Direct as well as indirect evidence has pointed toward Ca(2+) as an important determinant of interleukin-1beta (IL-1beta)-induced beta-cell dysfunction and apoptosis. In the present study, we show that IL-1beta-induced apoptosis and necrosis in primary rat beta-cells and MIN6 cells largely depends on ER stress, ER Ca(2+) release, and c-Jun N-terminal kinase (JNK) activation. beta-cells also showed marked sensitivity to apoptosis induced by sarcoendoplasmic reticulum Ca(2+) ATPase (SERCA) blockers, thapsigargin and cyclopiazonic acid (CPA). IL-1beta induced ER Ca(2+) release, which was paralleled by an IL-1beta-dependent induction of JNK activation and the ER stress response, including activation of PRK (RNA-dependent protein kinase)-like ER kinase (PERK). Furthermore, reduced activation of JNK, utilizing JNK inhibitor SP600125, resulted in significant protection from IL-1beta- or thapsigargin-induced apoptosis via ER stress. In conclusion, our results suggest that the IL-1beta-induced depletion of ER Ca(2+) and activation of the ER stress via JNK pathway are potential contributory mechanisms to beta-cell death.

A novel rat model of chronic heart failure following myocardial infarction.

In this report, we describe an improved method for the establishment of reproducible congestive heart failure (CHF) in a rat model. The area of myocardial infarction (MI) after ligation of the left anterior descending (LAD) coronary artery was quantified. Histological changes, heart function detected by echocardiography and isolated Langendorff perfusion, and selected biochemical factors were monitored after ligation of the LAD. Contrary to previous beliefs, thoracotomy in the second intercostal space provided a much better visualization of and easier access to the LAD and significantly reduced the mortality rate. Surface electrocardiogram (ECG) showed that the S-T interval was arched raised upward immediately after ligation. Typical morphological and functional changes of CHF were observed after LAD ligation. Cardiomyocytes in the infarcted zone were depleted and deranged. Biochemical analysis and enzyme-linked immunosorbent assay (ELISA) showed that superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and nitric oxide (NO) levels were significantly lowered in rats with MI than in the normal and sham groups, whereas serum malondialdehyde (MDA), MB isoenzyme of creatine kinase (CK-MB), cardiac troponin (cTnT) and C-reactive protein (CRP) levels were elevated. After MI, N-terminal pro-brain natriuretic peptide (NT-proBNP) was increased but insulin-like growth factor I (IGF-I) and vascular endothelial growth factor (VEGF) in culture supernatant were lower than in the normal and sham groups. We present an improved model for maximal reproducibility of experimental CHF in rats which allows the study of molecular and physiological variables in relation to CHF.

Association of CHADS2 and CHA2DS2-VASc Scores with Left Atrial Thrombus with Nonvalvular Atrial Fibrillation: A Single Center Based Retrospective Study in a Cohort of 2695 Chinese Subjects.

The main mechanism of the CHADS2 and CHA2DS2-VASc scores to predict stroke in nonvalvular atrial fibrillation (NVAF) is still controversial. We evaluated the association of the CHADS2 and CHA2DS2-VASc scores with left atrial thrombus (LAT) as detected by transesophageal echocardiographic (TEE) and compared the predictive ability of these risk stratification schemes with nonvalvular atrial fibrillation (NVAF). Data from 2,695 consecutive NVAF patients in whom TEE was performed for screening LAT from July 2007 to February 2014 were analyzed. Only 3% of the subjects had LAT. Presence of LAT was not significantly associated with either CHADS2 (P = 0.07) or CHA2DS2-VASc score (P = 0.12). The area under the curve (AUC) concerning LAT prediction using CHADS2 and CHA2DS2-VASc was 0.574 and 0.569, respectively. A composition model includes previous stroke or transient ischemic attack, nonparoxysmal AF, moderate to severe left ventricular systolic dysfunction, left atrial enlargement, and cardiomyopathy which improved the discrimination significantly (AUC = 0.743). In our cohort, both CHADS2 and CHA2DS2-VASc scores were of limited value for predicting LAT in patients with NVAF. This questions the CHADS2/CHA2DS2-VASc score predicting stroke mainly through the mechanism of cardiogenic embolism. A scoring scheme combining clinical and echocardiographic parameters may better predict LAT as a surrogate for cardioembolic risk in NVAF patients.

Mechanism of effective nocardioform foam control measures for non-selector activated sludge systems.

Solids retention time (SRT), biological scum trapping and recycle, and the dynamic equilibrium between Nocardioform populations in the foam and the mixed liquor are the controlling factors in activated sludge foaming events caused by Nocardioform bacteria. For the operating modes described in this paper, a cured mixed liquor foaming condition (filament counts of approximately 10(5) intersections/g volatile suspended solids) was only achieved when SRT control, selective wasting, and polymer addition were in effect. Solids retention time control, with the SRT remaining below 1.5 days, and selective wasting will cure a severely foaming mixed liquor, but effects will only be observed after 3 or 4 months after implementation. The combined wastage of Nocardioform bacteria from selective wasting and SRT control can ensure long-term foam control to the operation of a pure-oxygen activated sludge system with foam-trapping features. An SRT of 0.3 days will result in the complete washout of Nocardioform bacteria from the activated sludge system, which can then operate at an SRT of 3 days free of Nocardioform. Polymer addition to mixed liquor is only effective for foam control when a large portion of the system biomass exists as a heavy layer of foam above the mixed liquor.

Short granular chain under vibration: Spontaneous switching of states.

We study experimentally a short chain of N(≤8) loosely connected spheres bouncing against a horizontal surface that vibrates sinusoidally at intensity Γ. Distinct states are identified: a base state of uniform bouncing in-sync with the substrate prevails at low values of Γ, whereas increasing Γ can induce transitions to two excited states with appreciable storage of energy around one or both ends of the chain. We find that, in a transitional window of Γ, the chain can even switch spontaneously among states, resolving the mystery why different modes of motion can be initiated at the same position in our previous work along a gradient of vibration [Phys. Rev. Lett. 112, 058001 (2014)]. Preliminary interpretations on the parametric dependences and the optimal frequency window for seeing these transitions are offered, based on the microscopic and statistical evidence in our experiments up to date.

Reversal of reentry and acceleration due to double-wave reentry: two mechanisms for failure to terminate tachycardias by rapid pacing.

OBJECTIVES: We sought to demonstrate mechanisms by which rapid pacing can cause conduction block without terminating reentry. BACKGROUND: Rapid pacing can fail to terminate or can accelerate tachycardias in patients. Mechanisms for these responses are poorly understood. METHODS: We studied reentry in the canine atrial tricuspid ring and a left ventricular ring in vitro in 12 preparations. Activations were recorded from 10 sites around the ring, and monophasic action potentials were recorded from critical sites of block. Rapid pacing at cycle lengths that intermittently caused conduction block was performed at multiple sites. RESULTS: Action potential alternans contributed to block of an orthodromic impulse during rapid pacing. When pacing continued for two stimuli after orthodromic block, a second episode of block could reverse the direction of tachycardia. Continued pacing at this site was likely to produce block of an antidromic impulse, which may initiate double-wave reentry. Double-wave reentry could be sustained or nonsustained. Its cycle length was 56% to 77% of the single-wave cycle length. The ratio of double-wave cycle length to single-wave cycle length was inversely correlated with the relative excitable gap (p < 0.01). Double-wave reentry can be a mechanism for persistent cycle length alternation during tachycardia. CONCLUSIONS: Successful termination of reentry by rapid pacing required block of an othrodromic impulse and stopping pacing within one stimulus after orthodromic block. Reversal of reentry makes the circuit resistant to termination from this site of pacing. Antidromic block can cause acceleration due to double-wave reentry when there is a substantial excitable gap.

Bioinformatic analysis of the microarray gene expression profile in degenerative intervertebral disc cells exposed to TNF-α.

OBJECTIVE: We performed a bioinformatic analysis of the microarray data on the gene expression profiles of degenerative intervertebral disc cells after exposure to tumor necrosis factor-α (TNF-α) to uncover the key genes that were differentially expressed between cells with and without exposure, and to explore the related signaling pathways and interaction networks, providing clues for future investigations on the molecular mechanisms of disc degeneration. MATERIALS AND METHODS: The microarray data for degenerative intervertebral disc cells after stimulation with TNF-α were downloaded from a public database, the GEO (Gene Expression Omnibus), in order to identify the genes that were differentially expressed between untreated degenerative disc cells and those stimulated with TNF-α, and then analyses of the gene ontology, signaling pathways and interaction networks for the differentially expressed genes were conducted using the DAVID, STRING and other online tools. RESULTS: A total of 753 differentially expressed genes were found in the degenerative annulus fibrosus disci intervertebralis cells after stimulation with TNF-α, including 458 upregulated genes and 295 downregulated genes. The Gene Ontology annotation analysis showed that these differentially expressed genes were mainly associated with the extracellular matrix, damage reactions, inflammatory reactions, and the regulation of apoptosis. A signaling pathway analysis showed that these differentially expressed genes were mainly involved in the interactions of cytokines, apoptosis, NOD-like receptors, chemokines, and other signal transduction pathways. The interaction network analysis indicated that JUN, CCL3, ANHK and other genes may play key roles in intervertebral disc degeneration. CONCLUSIONS: The bioinformatic analysis of the gene expression profiles of degenerative intervertebral disc cells stimulated with TNF-α showed that CCL3 and other genes may play a role in the development of the disc degeneration induced by inflammatory reactions. This suggests that bioinformatics methods can be used to identify potential therapeutic target genes, and to provide new insight into intervertebral disc degeneration.

Efficacy of low-dose rituximab in combination with recombinant human thrombopoietin in treating ITP.

OBJECTIVE: This work aims to observe the efficacy and safety of low-dose rituximab in combination with recombinant human thrombopoietin in treating immune thrombocytopenia (ITP). PATIENTS AND METHODS: Fourteen ITP patients were treated four times with 100 mg qw of rituximab in combination with 300 µg/kg/d ih recombinant human thrombopoietin (rhTPO) for 14 d. Platelet count in peripheral blood, serum immunoglobulin, and lymphocyte subgroups by flow cytometry were detected regularly both pre- and post-treatment. RESULTS: Among the 14 patients, seven complete responses, six responses, and one no response were obtained, with an overall response of 93%. CONCLUSIONS: Low-dose rituximab in combination with rhTPO is effective in treating ITP.

Polymorphisms within the HLA-DRw6 haplotype. III. DQ alpha and DQ beta polymorphism associated with HLA-D.

We have studied HLA-DQ encoded antigens from HLA-DRw6 homozygous cells and analyzed the DQ region at the DNA level. HLA-DQ molecules were isolated from EBV transformed B-cell lines and analyzed for DQ alpha and DQ beta polymorphism. From the same set of cells, DNA was isolated and analyzed for RFLP. Polymorphism could be detected by both techniques, i.e., on the protein level and on the DNA. The variation in pI of the DQ alpha and beta chains correlated with the polymorphism as detected by HTC typing, as did the variation in molecular weight of the bands hybridizing to DQ specific cDNA probes; identical patterns were detected for cells of one HLA-D specificity and different patterns for different HLA-D types. Additionally, DQ reactive PLT reagents were raised against DRw6 positive cells. Panel studies revealed that these DQ reactive proliferative T cells can discriminate between the polymorphic DQ antigens on cells with different HLA-D specificities.

Characterization and localization of atriopeptin in rat atrium.

An antiserum specific for atriopeptin was used to characterize and localize atriopeptin-like immunoreactive material in rat atrium by radioimmunoassay and immunohistochemical techniques. The antiserum recognizes atriopeptin I, atriopeptin III, and alpha-human atrial natriuretic polypeptide, but does not recognize met-enkephalin, cholecystokinin, dynorphin A, bradykinin, substance P, or beta-endorphin. A high content of atriopeptin was found in crude extracts of rat atria, as compared to ventricles, and the atriopeptin-like immunoreactive material was found to be located exclusively in granules within atrial cardiocytes. Fractionation of the immunoreactive material by gel filtration and reverse-phase HPLC revealed the presence of multiple atriopeptins.

Met-enkephalin-Arg6-Phe7-like immunoreactive substances mediate electroacupuncture analgesia in the periaqueductal gray of the rabbit.

The present study was undertaken to investigate whether the C-terminal extended Met-enkephalin heptapeptide (Met-enkephalin-Arg6-Phe7, MEAP) played a role in mediating the analgesic effect of electroacupuncture in rabbits. MEAP and its degrading enzyme inhibitor captopril as well as antiserum against MEAP were injected into the periaqueductal gray (PAG) via a previously implanted cannula. Their effects on nociception were tested by the escape response latency (ERL) elicited by radiant heat applied on the skin of the snout. (1) Microinjection of MEAP (30-240 nmol) into PAG produced a dose-dependent analgesic effect which was 2.5 times more potent than Met-enkephalin (MEK) and 3 times less potent than morphine. The complete reversal of the analgesia elicited by 240 nmol of MEAP by a small dose of naloxone (0.1 mg/kg, i.v.) indicates that the effect of MEAP is mediated by naloxone sensitive opioid receptors. (2) In rabbits, a dose-dependent analgesia was elicited by an intra-PAG injection of captopril (60-240 nmol). A single dose of 240 nmol captopril increased ERL by more than 100%. This effect could be reversed by 30 nmol of naloxone injected into the same site, or by antiserum recognizing MEAP (1 microliter, titer 1:1500) but not by antiserum recognizing MEK (1 microliter, 1:8000) suggesting that captopril was able to protect MEAP from degradation. (3) Intra-PAG injection of 60 nmol of captopril significantly potentiated the after effect of electroacupuncture (EA) induced analgesia. This effect could be blocked either by 30 nmol (but not 7.5 nmol) of naloxone, or by 1 microliter (but not 0.1 microliter) of MEAP antiserum.(ABSTRACT TRUNCATED AT 250 WORDS)