[Discussion on the composition and implementation of diagnosis and treatment strategies for whole field pain management strategy]

Pain is the fifth major vital sign, and chronic pain is a large category of diseases that affects health seriously. At present, the incidence of chronic pain is high, but the overall treatment satisfaction is low. It is necessary to continuously optimize pain diagnosis and treatment strategies and improve the connotation of pain management. Based on the clinical practice of our pain center, combined with relevant literature, the article proposes a diagnosis and treatment strategy of "whole field pain management" should be carried out from the four dimensions of feeling, emotion, cognition, and behavior. Innovative digital pain diagnosis and treatment technologies such as VR/MR and brain-computer interface are used to regulate emotional, cognitive, and behavioral regulation, and combined with lifestyle changes, rehabilitation physiotherapy, drugs, and minimally invasive interventional therapy to constitute a " whole field pain management strategy" to explore the new development direction of further improving the management of chronic pain.

[Impact of different diagnostic criteria for assessing mild micro-hepatic encephalopathy in liver cirrhosis: an analysis based on a prospective, multicenter, real-world study]

Objective: To compare the differences in the prevalence of mild micro-hepatic encephalopathy (MHE) among patients with cirrhosis by using the psychometric hepatic encephalopathy score (PHES) and the Stroop smartphone application (Encephal App) test. Methods: This prospective, multi-center, real-world study was initiated by the National Clinical Medical Research Center for Infectious Diseases and the Portal Hypertension Alliance and registered with International ClinicalTrials.gov (NCT05140837). 354 cases of cirrhosis were enrolled in 19 hospitals across the country. PHES (including digital connection tests A and B, digital symbol tests, trajectory drawing tests, and serial management tests) and the Stroop test were conducted in all of them. PHES was differentiated using standard diagnostic criteria established by the two studies in China and South Korea. The Stroop test was evaluated based on the criteria of the research and development team. The impact of different diagnostic standards or methods on the incidence of MHE in patients with cirrhosis was analyzed. Data between groups were differentiated using the t-test, Mann-Whitney U test, and χ (2) test. A kappa test was used to compare the consistency between groups. Results: After PHES, the prevalence of MHE among 354 cases of cirrhosis was 78.53% and 15.25%, respectively, based on Chinese research standards and Korean research normal value standards. However, the prevalence of MHE was 56.78% based on the Stroop test, and the differences in pairwise comparisons among the three groups were statistically significant (kappa = -0.064, P < 0.001). Stratified analysis revealed that the MHE prevalence in three groups of patients with Child-Pugh classes A, B, and C was 74.14%, 83.33%, and 88.24%, respectively, according to the normal value standards of Chinese researchers, while the MHE prevalence rates in three groups of patients with Child-Pugh classes A, B, and C were 8.29%, 23.53%, and 38.24%, respectively, according to the normal value standards of Korean researchers. Furthermore, the prevalence rates of MHE in the three groups of patients with Child-Pugh grades A, B, and C were 52.68%, 58.82%, and 73.53%, respectively, according to the Stroop test standard. However, among the results of each diagnostic standard, the prevalence of MHE showed an increasing trend with an increasing Child-Pugh grade. Further comparison demonstrated that the scores obtained by the number connection test A and the number symbol test were consistent according to the normal value standards of the two studies in China and South Korea (Z = -0.982, -1.702; P = 0.326, 0.089), while the other three sub-tests had significant differences (P < 0.001). Conclusion: The prevalence rate of MHE in the cirrhotic population is high, but the prevalence of MHE obtained by using different diagnostic criteria or methods varies greatly. Therefore, in line with the current changes in demographics and disease spectrum, it is necessary to enroll a larger sample size of a healthy population as a control. Moreover, the establishment of more reliable diagnostic scoring criteria will serve as a basis for obtaining accurate MHE incidence and formulating diagnosis and treatment strategies in cirrhotic populations.

Endogenous corticotropin-releasing factor potentiates the excitability of presympathetic neurons in paraventricular nucleus via activation of its receptor 1 in spontaneously hypertensive rats

It is well established that increased excitability of the presympathetic neurons in the hypothalamic paraventricular nucleus (PVN) during hypertension leads to heightened sympathetic outflow and hypertension. However, the mechanism underlying the overactivation of PVN presympathetic neurons remains unclear. This study aimed to investigate the role of endogenous corticotropin-releasing factor (CRF) on the excitability of presympathetic neurons in PVN using Western blot, arterial blood pressure (ABP) and renal sympathetic nerve activity (RSNA) recording, CRISPR/Cas9 technique and patch-clamp technique. The results showed that CRF protein expression in PVN was significantly upregulated in spontaneously hypertensive rats (SHRs) compared with normotensive Wistar-Kyoto (WKY) rats. Besides, PVN administration of exogenous CRF significantly increased RSNA, heart rate and ABP in WKY rats. In contrast, knockdown of upregulated CRF in PVN of SHRs inhibited CRF expression, led to membrane potential hyperpolarization, and decreased the frequency of current-evoked firings of PVN presympathetic neurons, which were reversed by incubation of exogenous CRF. Perfusion of rat brain slices with artificial cerebrospinal fluid containing CRF receptor 1 (CRFR1) blocker, NBI-35965, or CRF receptor 2 (CRFR2) blocker, Antisauvagine-30, showed that blocking CRFR1, but not CRFR2, hyperpolarized the membrane potential and inhibited the current-evoked firing of PVN presympathetic neurons in SHRs. However, blocking CRFR1 or CRFR2 did not affect the membrane potential and current-evoked firing of presympathetic neurons in WKY rats. Overall, these findings indicate that increased endogenous CRF release from PVN CRF neurons enhances the excitability of presympathetic neurons via activation of CRFR1 in SHRs.

[Epidemiological distribution of genotypes and sub-genotypes of hepatitis B virus in 15 ethnic groups in China]

Objective: To understand the distribution of genotypes and sub-genotypes of HBV in different ethnic groups in China. Methods: The HBsAg positive samples were selected by stratified multi-stage cluster sampling from the sample base of national HBV sero-epidemiological survey in 2020 for the amplification of S gene of HBV by nested PCR. A phylogeny tree was constructed to determine the genotypes and sub-genotypes of HBV. The distribution of genotypes and sub-genotypes of HBV were analyzed comprehensively by using laboratory data and demographic data. Results: A total of 1 539 positive samples from 15 ethnic groups were successfully amplified and analyzed, and 5 genotypes (B, C, D, I and C/D) were detected. The proportion of genotype B was higher in ethnic group of Han (74.52%, 623/836), Zhuang (49.28%, 34/69), Yi (53.19%, 25/47), Miao (94.12%, 32/34), Buyi (81.48%, 22/27). The proportions of genotype C were higher in ethnic groups of Yao (70.91%, 39/55). Genotype D was the predominant genotype in Uygur (83.78%, 31/37). Genotype C/D were detected in Tibetan (92.35%,326/353). In this study, 11 cases of genotype I were detected, 8 of which were distributed in Zhuang nationality. Except for Tibetan, sub-genotype B2 accounted for more than 80.00% in genotype B in all ethnic groups. The proportions of sub-genotype C2 were higher in 8 ethnic groups, i.e. Han, Tibetan, Yi, Uygur, Mongolian, Manchu, Hui and Miao. The proportions of sub-genotype C5 were higher in ethnic groups of Zhuang (55.56%, 15/27) and Yao (84.62%, 33/39). For genotype D, sub-genotype D3 was detected in Yi ethnic group and sub-genotype D1 was detected in both Uygur and Kazak. The proportions of sub-genotype C/D1 and C/D2 in Tibetan were 43.06% (152/353) and 49.29% (174/353). For all the 11 cases of genotype I infection, only sub-genotype I1 was detected. Conclusions: Five genotypes and 15 sub-genotypes of HBV were found in 15 ethnic groups. There were significant differences in the distribution of genotypes and sub-genotypes of HBV among different ethnic groups.

[Effect of China Children's Asthma Action Plan on exercise in school-age children with bronchial asthma]

Objective: To investigate the effect of China Children's Asthma Action Plan (CCAAP) on the exercise status of school-age children with asthma. Methods: We included 400 school-age asthmatic children as research objects from CCAAP asthma management platform of the Affiliated Hospital of Qingdao University during March 1, 2018 to February 28, 2021 by simple random sampling method. The questionnaires of basic information and international physical activity were applied through WeChat or face to face investigation to collect the basic information and exercise status of the object. There were 346 valid questionnaires included in the study to compare the differences in exercise status and incidence of exercise-related asthma-like symptoms between the good and poor CCAAP application groups. Results: There were 232 (67.05%) and 114 (32.95%) cases in good and poor CCAAP application group, respectively. Age, female proportion and BMI of good CCAAP application group were (8±2) years, 47.0% (109/232) and (19.79±2.32) kg/m², respectively, no statistic difference comparing to poor CCAAP application group [(8±2) years, 46.5% (53/114) and (19.87±2.43) kg/m², respectively] (all P values>0.05). In good CCAAP application group, 30.18% (70/232) achieved the standard of moderate (high) intensity exercise per day, no statistic difference comparing to poor CCAAP application group [29.82% (34/112)] (P=0.947); 31.90% (74/232) participated in high-intensity exercise per week, higher than that of poor CCAAP application group [17.54% (20/112)] (P=0.005); incidence of exercise-related asthma-like symptoms was 19.83% (46/232), lower than that of poor CCAAP application group [29.82% (34/112)] (P=0.038). Conclusion: CCAAP promotes the exercise of school-age children with asthma.

P–412 Low serum hCG levels adjusted for the hCG trigger dose in fresh cycles may be associated with a poor clinical pregnancy rate of FET cycles

Study question

Is there any association between serum human chorionic gonadotropin (hCG) levels after trigger at previous fresh cycles and pregnancy outcomes of frozen-thawed embryo transfer (FET) cycles?

Summary answer

Low adjusted serum hCG level after hCG trigger at fresh cycles is negatively associated with clinical pregnancy rates (CPR) of hormone replacement treatment-FET (HRT-FET). What is known already: Literature showed that low serum hCG levels after the same dose of hCG trigger was associated with reduced pregnancy outcomes of the fresh cycles. However, the relationship between hCG levels after trigger at fresh cycles and pregnancy outcomes of FET cycles remains unknown.

Study design, size, duration

This matched retrospective study was conducted at a Reproductive Medicine Center between 2016 and 2018. Subjects performing HRT-FET cycles, whose previous fresh cycles used a bolus of hCG alone or a bolus of GnRHa combined with hCG for trigger were included. A total of 186 HRT-FET cycles with complete data was included for the final analysis.

Participants/materials, setting, methods

The study population was grouped into women with intramuscular injection of hCG prior to secretory transformation (hCG group, n = 93) and a comparison group (control group, n = 93) of women without hCG addition matched for patients’ age and duration of infertility. At the previous fresh cycles, serum hCG levels were measured 12 hours later after hCG trigger (defined as the “hCG+12 h” timepoint), and were adjusted for doses (defined as adjusted hCG levels). Main results and the role of chance: For patients achieving clinical pregnancy, the adjusted hCG level significantly increased (P &lt; 0.05). Meanwhile, the ROC curve also showed a significantly predictive value of adjusted serum hCG levels at the “hCG+12 h” timepoint for CPR in HRT- FET cycles (AUC=0.626, 95%CI: 0.512–0.740) and the optimal hCG threshold proposed by ROC for CPR was 46.31 mIU/mL with sensitivity of 71.4% and specificity of 56.9%. For all patients, the CPR in hCG group was significantly higher than that in control group (61.3% vs. 44.1%). Furthermore, all cycles were then divided into four groups based on the injection of hCG prior to secretory transformation in HRT-FET cycles and this cut-off value of hCG levels at the “hCG+12 h” timepoint. For patients with adjusted hCG levels ≤46.31 mIU/mL, the CPR was significantly improved in hCG group compared with control group (61.1% vs. 29.3%). But for patients with adjusted hCG levels &gt;46.31 mIU/mL, no statistically significant difference was observed between the hCG and control group (61.4% vs. 55.8%).

Limitations, reasons for caution

Although the results achieved statistically significant, the sample size was relatively small, which limits our ability to draw a definitive conclusion. The reason of the small sample size may be that to reduce the risk of OHSS, doctors would give preference to trigger with GnRH agonist in our center.

Wider implications of the findings: Adjusted serum hCG levels might represent a potential factor to guide adequate support in the subsequent HRT-FET cycles. Meanwhile, for patients with low adjusted serum hCG levels, intramuscular hCG injection prior to secretory transformation may be a good compensation way to rescue pregnancy impair in the subsequent HRT-FET cycles.

Trial registration number

N/A.

CIHH protects the heart against left ventricular remodelling and myocardial fibrosis by balancing the renin-angiotensin system in SHR

AIM

The aim of our study was to clarify the cardioprotection of chronic intermittent hypobaric hypoxia (CIHH) and the underlying mechanism in spontaneously hypertensive rats (SHR).

MAIN METHODS

Adult male rats were divided into normal blood pressure Wistar-Kyoto rats (WKY) control (WKY-CON), WKY rats with CIHH treatment (WKY-CIHH), SHR control (SHR-CON) and SHR with CIHH treatment (SHR-CIHH) groups. SHR-CIHH and WKY-CIHH rats were subjected to hypobaric hypoxia simulating 4000-m altitude for 35 days, 5 h per day. Arterial blood pressure and cardiac function parameters, including ejection fraction, fractional shortening and left ventricular (LV) wall thickness, were evaluated. Cardiac pathomorphology and myocardial fibrosis were determined. The expression of angiotensin-converting enzyme (ACE), ACE2, Ang II, Ang1-7, AT1 receptor, Mas receptor, IL-6, TNF-α，IL-10, SOD and MDA were assayed in myocardium.

KEY FINDINGS

CIHH significantly decreased arterial blood pressure, alleviated LV hypertrophy, and improved cardiovascular function in SHR (P < 0.05-0.01). Also, CIHH protected SHR heart against morphological changes and fibrosis. In addition, CIHH significantly down-regulated the ACE/Ang II/AT1 receptor axis and up-regulated the ACE2/Ang1-7/Mas axis of renin-angiotensin system (RAS) in SHR (P < 0.05-0.01). CIHH significantly reduced IL-6, TNF-α, and MDA levels, but increased IL-10 and SOD in SHR myocardium (P < 0.05-0.01).

SIGNIFICANCE

The CIHH treatment protected the heart of SHR against LV remodelling and myocardial fibrosis, which might be carried out through a balance in the ACE/Ang II/AT1 axis and the ACE2/Ang1-7/Mas axis of the RAS to reduce inflammation, and inhibit oxidative stress.

Development of a prognostic model based on an immunogenomic landscape analysis of colorectal cancer

Screening and therapeutic programs for colorectal cancer (CRC) are invasive or not effective and unable to meet patient needs. Major advances in immunogenomics may change this status but need more exploration. Differentially expressed genes and immune-related genes (IRGs) were identified by computational methods. A prognostic model was established and validated based on survival-related IRGs via stepwise multivariate Cox regression analysis. Nine IRGs were selected and identified as survival-related genes. A 7-gene prognostic model could offer a preliminary and valid determination of risk in CRC patients. The area under the curve of the receiver operating characteristic was 0.672. The 7-gene prognostic model might be used as a novel prognostic tool in CRC patients.

[Hearing assessment and follow-up study of aeonatal deafness gene screening homozygous mutation infants]

Objective:To analyze the hearing assessment characteristics and follow-up of some deafness gene screening homozygous infants in Zhuhai. Method:The clinical data of 28 newborns with homozygous mutations transferred to Zhuhai Maternal and Child Health Hospital from Feb. 1, 2015 to Oct. 25, 2018 in hospitals of Zhuhai City were retrospectively analyzed. All the children were screened for hearing. The hearing characteristics and long-term follow-up results of homozygous mutations at different gene sites were analyzed by auditory diagnosis and behavioral follow-up from 1 to 3 years. Result:Fourteen cases of GJB2 c.109G>A with a homozygous mutation, 11 cases passed the hearing screening, the audiological diagnosis was normal, and the behavior test and follow-up were normal from 1 to 3 years. Hearing screening was not passed in 3 newborns, mild to moderate abnormalities of single or bilateral ears were diagnosed by audiology, 1 000 Hz without positive, and middle ear lesions were diagnosed. Eight cases of GJB2 c.235del C homozygous mutation were followed up by behavioral audiometry and follow-up from 1 to 3 years after cure. Among them, 5 cases were diagnosed as severe hearing impairment of bilateral ears and 3 cases as mild and moderate hearing impairment. One case of GJB3 547G>A homozygous mutation was followed up for 1-3 years, and all of them failed to pass the follow-up of behavioral audiometry and follow-up. Four cases of SLC26A4 IVS7-2A>G, 1 case of SLC26A4 1229C>T homozygous mutation, all of them failed to pass the neonatal hearing screening. All the patients were diagnosed as severe hearing impairment of binaural hearing, and the follow-up of 1-3 years' follow-up did not pass the follow-up tests. Conclusion:GJB2 C.235del C, SLC26A4 IVS7-2A>G locus homozygous mutation infant hearing impairment was mainly severe hearing impairment in bilateral ears, and there was no change in 1-3 years follow-up. GJB2 C.109G A homozygous mutant infants had normal hearing, and it was suggested that they should be followed up closely. It is very important to give correct and reasonable genetic counseling to parents with GJB2 C.109G A homozygous mutation without unnecessary panic.

[A follow-up study of abnormal mutation in neonatal deafness gene screening]

Objective: To screen, diagnose and follow up the abnormal mutation in the gene screening of neonatal deafness. Methods: A total of 24161 newborns born in Zhuhai Maternal and Child Health Hospital from February 1, 2015 to January 31, 2008 were screened for hearing and deafness genes, and audiological screening, diagnosis and 1-3 years follow-up were carried out for the newborns with positive gene screening. Results: There were 991 cases of deafness gene mutation (533 males and 458 females), and the rate of abnormal mutation was 4.10%(991/24 161). Among them, 921 cases were single heterozygous mutation, 130 cases were failed in primary hearing screening, 11 cases were failed in secondary hearing screening, 8 cases were abnormal in audiological diagnosis finally. In these 8 cases, 3 were diagnosed as otitis media and passed audiological follow-up after cure, 2 cases of single ear sensorineural injury caused by high-risk factors, passed after close audiological follow-up, and the other 3 cases were closely audiological follow-up while none of them were successfully sequenced. All of them were moderate to severe sensorineural deafness, 1 case was heterozygous mutation at 3 loci of GJB2(c.235delC,c.408C>A,c.134G>A), 1 case was heterozygous mutation at 2 loci of GJB2(c.235delC, c.109G>A), and 1 case was single heterozygous mutation of GJB2(c.235delC). The remaining 913 cases who passed the primary screening, secondary screening or hearing diagnosis were followed up for 1 to 3 years. Three cases of multiple heterozygous mutation were found in gene screening(2 cases were SLC26A4 2168A>G, IVS7-2A>G, 1 case was GJB2 c.176_191del 16bp, c.299_300del AT), all of them passed both primary and secondary hearing screening. In these 3 cases, the final audiological diagnosis was moderate sensorineural deafness in both ears, with no improvement in the follow-up of 1-3 years. There were 9 monogenic homozygous mutations, 7 failed in primary hearing screening, 3 failed in secondary hearing screening and also failed in audiological diagnosis and 1-3 years' audiological follow-up, all of whom were GJB2 c.235 del C homozygous mutations, and one of whom had a definite family history of deafness. The remaining 6 cases of homozygous mutation diagnosed by primary screening, secondary screening or hearing diagnosis were GJB2 c109G>A homozygous mutation, and passed the 1-3 years' hearing follow-up. 58 children with mtDNA mutations, including 2 with 12S rRNA 1494C>T homozygous mutation, 47 with 1555A>G homozygous mutation, and 9 with 1555A>G heterozygous mutation, all passed the primary or secondary hearing screening, and were instructed to ban ototoxic drugs for the whole life, and passed the 1-3 years' hearing follow-up. Conclusions: The audiological follow-up of children with monogenic heterozygous mutations in deafness gene screening is generally normal. In case of abnormality, the influencing factors such as otitis media should be excluded at first. In case of unexplained moderate to severe sensorineural deafness, the whole-gene sequencing should be performed to find possible pathogenic factors. The children with homozygous mutation or compound heterozygous mutation in gene screening, most of whom show different degrees of hearing loss, should be followed up for a long time, and provide parents with scientific and reasonable genetic counseling according to the mutation genes and loci,. The hearing of drug-induced deafness gene carriers is normal after birth. Parents should be advised to strengthen prevention and follow-up is generally enough.

Chronic intermittent hypobaric hypoxia attenuates skeletal muscle ischemia-reperfusion injury in mice

AIM

The aim of this study was to investigate the protective effect of chronic intermittent hypobaric hypoxia (CIHH) against skeletal muscle ischemia-reperfusion (IR) injury and to determine the underlying mechanism.

MAIN METHODS

C57BL/6 mice were randomly divided into 3 groups: skeletal muscle IR injury group (IR), CIHH pretreatment following IR group (IR + CIHH), and sham operation group (Sham). The skeletal muscle IR injury model was induced by the unilateral application of a tourniquet on a hind limb for 3 h and then releasing it for 24 h. CIHH pretreatment simulating a 5000-m altitude was applied 6 h per day for 28 days. The functional and morphological performance of IR-injured gastrocnemius muscle was evaluated using contraction force, H&E staining, and transmission electron microscopy. IR injury-induced CD68⁺ macrophage infiltration was assessed by immunofluorescence. TNFα levels in serum and muscle were measured by ELISA and western blotting, respectively. Apoptosis was examined by TUNEL staining and Cleaved Caspase-3 protein expression.

KEY FINDINGS

Acute IR injury resulted in reduced contraction tension, morphological destruction, macrophage infiltration, increased TNFα levels, and apoptosis in gastrocnemius muscle. CIHH pretreatment significantly ameliorated contraction function and morphological performance in IR-injured skeletal muscle. In addition, CIHH pretreatment resulted in marked decreases in CD68⁺ macrophage infiltration, TNFα levels, and apoptosis.

SIGNIFICANCE

These data demonstrated that CIHH has a protective effect against acute IR injury in skeletal muscle via inhibition of inflammation and apoptosis.

[Congenital ear deformity screening and non-invasive correction effect analysis]

Objective:To synchronously perform external auricle examination during neonatal hearing screening, follow up auricle deformity with neonatal disease screening system, and calculate the incidence of auricle deformity, self-healing rate, correction rate, incidence of complications and the relationship with hearing loss in Zhuhai area. Method:According to the diagnostic criteria of auricle deformity, the newborns in Zhuhai Maternal and Child Health Hospital were examined on the spot within 2 months. The deformity auricle was registered and uploaded into the newborn hearing screening system. The newborns were followed up by short message notification 7 days after birth, and then compared with the photo uploading system again. At 14 days, the ears of those who could not self-heal were went on non-invasive correction, and collect of relevant data for summary analysis. Result:Among the 1 073 newborns(2 146 ears), 26(37 ears) with malformed ears were treated with auricular pattern correction.The corrective rates of newborns less than 14 days, 14-30 days and 31-60 days were 95%, 90% and 87% respectively, and the incidence of complications were 50%, 58% and 69%, respectively. Conclusion:The incidence of auricular deformities in neonates is high. The earlier correction the better. The ear deformity can be detected at the earliest stage and missed diagnosis can be avoided by simultaneous hearing screening and ear deformity screening. During the window period of 7-14 d, by monitoring the self-healing rate of the affected ear excessive medical correction can be avoided. By hearing screening system statistics, ear shape malformation is not directly related to hearing loss.

[Efficacy of Yisaipu tapering in the treatment of ankylosing spondylitis]

Objective: To assess the efficacy of Yisaipu tapering in patients with ankylosing spondylitis (AS). Methods: A total of 87 cases of AS patients from Guangdong Second Provincial General Hospital who were treated with Yisaipu and celecoxib were retrospectively analyzed from February 2013 to April 2017.All patients received full dose Yisaipu and celecoxib in the initial 12 weeks.After that, the patients in the full dose group maintained Yisaipu (50 mg/w) treatment from the 13(rd) to 24(th) week, while tapering group received Yisaipu 50 mg subcutaneous injection once every other week.By using AS disease activity score (ASDAS), Bath AS functional index (BASFI) and magnetic resonance (MR) score of sacroiliac joint (SIJ) plus recording adverse events, differences of efficacy and safety between groups were compared. Results: ASDAS and BASFI of tapering group were 1.1±0.7 and 1.3±1.1, while those of full dose group were 1.0±0.7 and 1.1±1.0, respectively.No significant difference of ASDAS or BASFI was found between groups.Besides, the MR scores of tapering and full dose groups were 8±7 and 8±6 respectively before therapy, while they were significantly lower in the 24(th) week (4±4 and 4±3, P<0.05). However, changes of MR score between groups were similar (P>0.05). Conclusion: Dose tapering of Yisaipu subcutaneous injection might be effective for keeping stable of disease activity and function in patients with AS.Its efficacy is similar to those of full dose Yisaipu.

14-3-3 gene expression in regenerating rat liver after 2/3 partial hepatectomy

14-3-3 Proteins are a ubiquitous family of molecules that participate in protein kinase signaling pathways in all eukaryotic cells. Functioning as phosphoserine/phosphothreonine-binding modules, 14-3-3 proteins participate in the phosphorylation-dependent protein-protein interactions that control progression through the cell cycle, initiation and maintenance of DNA damage checkpoints, activation of MAP kinases, prevention of apoptosis, and coordination of integrin signaling and cytoskeletal dynamics. During liver regeneration after partial hepatectomy, normally quiescent hepatocytes undergo hypertrophy and proliferation to restore the liver mass. In this study, we investigated the expression patterns of 14-3-3 mRNAs in regenerating rat liver after 2/3 partial hepatectomy using real-time quantitative reverse transcription-polymerase chain reaction. All mRNAs of the 14-3-3 7 isotypes were expressed at 10 time points. Upregulation of 14-3-3x mRNA expression and downregulation of 14-3-3s mRNA expression from 0 to 6 h may play important roles in the entry into S-phase. Downregulation of 14-3-3b, g, s, h, and t mRNA expression from 24 to 30 h, when compared to 0 h, was closely related to entry into mitosis.

Paenibacillus susongensis sp. nov., a mineral-weathering bacterium

A Gram-stain-positive, rod-shaped, endospore-forming, aerobic bacterial strain, designated M327T, was isolated from the weathered surfaces of rock (mica schist) from Susong, Anhui Province, PR China. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain M327T belonged to the genus Paenibacillus and was related most closely to Paenibacillus terrigena A35T (98.6 % similarity) and Paenibacillus selenitireducens ES3-24T (98.3 %). Strain M327T contained meso-diaminopimelic acid in the cell wall and MK-7 as the major menaquinone. The main fatty acids of strain M327T were anteiso-C15 : 0 and iso-C16 : 0. The polar lipid profile contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, three unknown aminophospholipids and an unknown lipid. The total DNA G+C content of strain M327T was 48.6 mol%. Based on the low level of DNA–DNA relatedness (ranging from 26.6 to 33.1 %) to these type strains of species of the genus Paenibacillus and unique phenotypic characteristics, it is suggested that strain M327T represents a novel species of the genus Paenibacillus , for which the name Paenibacillus susongensis sp. nov. is proposed. The type strain is M327T ( = CCTCC AB 2014058T = LMG 28236T = JCM 19951T).

Human primary corneal fibroblasts synthesize and deposit proteoglycans in long-term 3-D cultures

Our goal was to develop a 3-D multi-cellular construct using primary human corneal fibroblasts cultured on a disorganized collagen substrate in a scaffold-free environment and to use it to determine the regulation of proteoglycans over an extended period of time (11 weeks). Electron micrographs revealed multi-layered constructs with cells present in between alternating parallel and perpendicular arrays of fibrils. Type I collagen increased 2-4-fold. Stromal proteoglycans including lumican, syndecan4, decorin, biglycan, mimecan, and perlecan were expressed. The presence of glycosaminoglycan chains was demonstrated for a subset of the core proteins (lumican, biglycan, and decorin) using lyase digestion. Cuprolinic blue-stained cultures showed that sulfated proteoglycans were present throughout the construct and most prominent in its mid-region. The size of the Cuprolinic-positive filaments resembled those previously reported in a human corneal stroma. Under the current culture conditions, the cells mimic a development or nonfibrotic repair phenotype.

DNA methylation and loss of protein expression in esophageal squamous cell carcinogenesis of high-risk area

DNA methylation is an important mechanism for gene silence. The purpose of this study was to investigate aberrant promoter methylation of the p16 and FHIT genes in tissues and plasma and loss of protein expression in esophageal precancerous conditions (EPC) and esophageal squamous cell carcinoma (ESCC) of high-risk area. Methylation-specific PCR(MSP) was employed to examine the DNA methylation in the plasma and tissues of 95 patients of EPC, ESCC and 10 chronic esophagitis (CE). Loss of protein expression of p16 and FHIT was detected immunohistochemically. In total 95 lesion tissues of EPC and ESCC, p16 methylation was found in 53 (55.79%) cases, and 41 of 53 (77.36%) cases were demonstrated deletion of the p16 protein immunohistochemically. FHIT methylation was found in 49 (51.58%) cases, and 40 of 49 (81.63%) were demonstrated deletion of the FHIT protein. Only 1 (10%) case of 10 CE p16 methylation was found in the tissues. In the plasma of total 105 samples, 2 of 23 high grade intraepithelial neoplasia (HGIN) and 12 of 37 ESCC were detected p16 methylation, and 2 of 23 HGIN and 14 of 37 ESCC were detected FHIT methylation. These results indicate that p16 and FHIT methylation may be one of the earliest events and an important mechanism for gene silencing in esophageal squamous cell carcinogenesis. This study may be helpful for screening the candidate molecular markers for early diagnosis of ESCC in high-risk area.

Investigation of the anthracene-nitroxide hybrid molecule as a probe for hydroxyl radicals

A new method for the determination of hydroxyl radicals is proposed. The method is based on the use of a hybrid molecule consisting of a fluorescent chromophore, anthracene, and a nitroxide radical. In the hybrid molecule, the nitroxide quenches the fluorescence of anthracene strongly. The reaction of hydroxyl radicals with dimethyl sulfoxide generates quantitatively methyl radicals, which then combine with the nitroxide moiety of the hybrid molecules to result in an increase in the fluorescence intensity. The fluorescence increase is proportional to the concentration of hydroxyl radicals. The proposed method is capable of detecting hydroxyl radicals generated in the Fenton system. It is a simple and sensitive technique for the determination of hydroxyl radicals.

Reduced-glutathione concentrations in Boleophthalmus pectinirostris tissues exposed to benzo(a)pyrene

The concentrations of reduced-glutathione (GSH) in liver and ovary of Boleophthalmus pectinirostris are quantified. The concentrations of GSH in the ovary are much higher than that of GSH in the liver(nearly 3 times of the liver). The study also investigates the changes of GSH contents in the two organs while the fishes were exposed to benzo(a)pyrene(BaP) at concentrations of 0, 0.05, 0.2 and 0.5 mg/L respectively for up to a week. The concentrations of GSH in the liver of BaP-exposed fish increased significantly with dose, whereas the concentrations of GSH in the ovary decreased significantly compared to controls. The results suggested that both the liver and the ovary are the primary organ in BaP metabolism, and that the changes of GSH levels may represent an adaptive response or toxic effect to BaP exposure.

Fe(II)-EDTA chelate-induced aromatic hydroxylation of terephthalate as a new method for the evaluation of hydroxyl radical-scavenging ability

The investigation of Fe(II)-EDTA chelate-induced aromatic hydroxylation of terephthalate in pH 7.4 phosphate buffer solution and a new method for the evaluation of hydroxyl radical-scavenging ability are reported. The method is based on attack of the hydroxyl radical on the terephthalate to produce highly fluorescent 2-hydroxyterephthalate, which is detected fluorimetrically. The formation of hydroxyl radical is believed to be the result of the reduction of molecular oxygen by Fe(II)-EDTA to form superoxide radical, which in turn dismutates to hydrogen peroxide, and then Fe(II)-EDTA catalyzes the decomposition of hydrogen peroxide to produce hydroxyl radical. The mechanism of the generation of hydroxyl radical in the proposed system was confirmed. This study established a simple and inexpensive method for the evaluation of the scavenging ability of some compounds on hydroxyl radicals.

[AVP-ergic mechanism in the rostral ventrolateral medulla:a possible role in stress-induced hyperviscosity]

The study was undertaken to find whether microinjection of vasopressin (AVP) into the rostral ventrolateral medulla (rVLM) affects blood pressure (BP) and blood viscosity in rats and to analyze the effects of AVP-ergic mechanism in the rVLM on stress-induced hyperviscosity of rats. The results are as follows. (1) Microinjection of AVP into the rostral ventrolateral medulla (rVLM) of normal rats resulted in a significant increase in BP and plasma viscosity, which was blocked by bilateral microinjection of AVP V(1) receptor antagonist (d(CH2)5 Tyr(Me)(2) AVP) into the same area. (2) The stress-induced pressor response and hyperviscosity was abolished by microinjection of AVP V(1) receptor antagonist into the rVLM, but not by AVP V(2) receptor antagonist ( adamantaneacetyl(1),O-Et-D-Tyr(2),Val(4),aminobutyryl(6),Arg(8,9) -vasopressin). Microinjection of AVP V(1) receptor antagonist of the same dosage into bilateral caudal ventrolateral medulla (cVLM) or intravenous injection of the antagonist of the same dosage had no effect. The above results suggest that the increase of BP and plasma viscosity induced by microinjection of AVP into rVLM and the stress-induced pressor response and hyperviscosity caused by restraining may be mediated by activation of the AVP V(1) receptor in the rVLM.

[Role of paraventricular nucleus in pressor response induced by dorsol part of midbrain periaqeductal gray stimulation]

Experiments were carried out on male SD rats anesthetized with urethane (700 mg/kg) and chloralose (35 mg/kg). The results were as follows: (1) The pressor response could be elicited by electrical stimulation of dorsol part of midbrain periaqueductal gray (dPAG) for 5 s every 5 min. The pressor response for each series of dPAG stimulation within 50 min was constant. This pressor response could be decreased by electrolytic cauterization of paraventricular (PVN) area, but unaffected by electrolytic lesion of fornix, anterior hypothalamic area, nucleus dorsomedialis hypothalami and nucleus ventromedicalis hypothalami. (2) Microinjection of an AVP-V1 receptor antagonist (CH2)5 [Tyr(Me)2AVP] (each side 0.1 nmol/0.1 microliter) into the bilateral rostral ventrolateral medulla (rVLM) partially inhibited the pressor response induced by PVN stimulation or by microinjection of D,L-homocysteric acid (DLH) (0.1 mol/0.2 microliter) into the PVN, but the mean artrtial pressure (MBP) and heart rate (HR) did not show any change when an AVP-V1 receptor antagonist or DLH was only used. (3) Microinjection of an AVP-V1 receptor antagonist into the bilateral rVLM partially inhibited the pressor response induced by dPAG stimulation. Therefore it is suggested that the effect of vasopression (AVP) released from PVN on the pressor response induced by dPAG stimulation is partly mediated by activation of AVP-V1 receptor in the rVLM.

A long-lifetime Ru(II) metal-ligand complex as a membrane probe

A luminescent metal-ligand complex, [Ru(bpy)2(dppz)]2+, (where dppz is dipyrido[3,2-a:2',3'-c] phenazine), was used as a photoluminescence probe for investigating submicrosecond lipid dynamics in a dipalmitoyl-L-alpha-phosphotidylglycerol (DPPG) model bilayer system. The luminescence of [Ru(bpy)2(dppz)]2+ in buffer is completely quenched but becomes luminescent when intercalated into DPPG vesicles. The experimental results show that the emission intensity of [Ru(bpy)2(dppz)]2+ intercalated into DPPG vesicles increases dramatically as temperature is increased towards the lipid phase transition temperature. This effect is abolished in bilayers containing a high concentration (> 30 mol%) of cholesterol, suggesting this probe is sensitive to the membrane composition. Frequency-domain emission intensity decays, measured as a function of increasing temperature towards the lipid phase transition temperature (2 to 57 degrees C), display two major lifetime components. The short lifetime disappears at temperatures well above the phase transition temperature. A comparison of oxygen quenching with iodide quenching suggests the heterogeneity of probe location at temperatures well below the lipid phase transition temperature and the homogeneity of probe location at temperature well above the lipid phase transition temperature. [Ru(bpy)2(dppz)]2+ displays polarized emission, enabling the study of membrane dynamics. The long decay time displayed by this probe allows measurement of the overall rotational correlation time of lipid vesicles on the microsecond time-scale. Because of the long lifetime, polarized emission, and background free nature of the photoluminescence measurements, [Ru(bpy)2(dppz)]2+ has numerous applications in the biophysical studies of membranes.

Use of a long-lifetime Re(I) complex in fluorescence polarization immunoassays of high-molecular-weight analytes

We describe a new class of fluorescence polarization immunoassays based on the luminescence from a Re(I) metal-ligand complex. Re(I) complexes are extremely photostable and possess useful photophysical properties including long lifetimes, high quantum yields, and high emission polarization in the absence of rotational diffusion. In the present study, a conjugatable, highly luminescent Re(I) metal-ligand complex, [Re(bcp)(CO)3(4-COOHPy)](ClO4), where bcp is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline and 4-COOHPy is isonicotinic acid, has been evaluated for use in fluorescence polarization immunoassays (FPIs) with high-molecular-weight antigens. This Re(I) complex (Re) displays highly polarized emission (with a maximum anisotropy near 0.3) in the absence of rotational diffusion and a long average lifetime (2.7 microseconds) when bound to human serum albumin (HSA) in oxygenated aqueous solution. The emission polarization of the Re-HSA conjugate is sensitive to the binding of anti-HSA, resulting in a significant increase in anisotropy. The labeled HSA was also used in a competition immunoassay where unlabeled HSA was also used as an antigen. These experimental results, combined with theoretical predictions, demonstrate the potential of this Re(I) metal-ligand complex as a luminescence probe in FPIs of high-molecular-weight analytes (10(5)-10(8) Da).

A long-lived, highly luminescent Re(I) metal-ligand complex as a biomolecular probe

A highly luminescent rhenium (I) metal-ligand complex [Re(bcp)(CO)3(4-COOHPy)](ClO4), where bcp is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline and 4-COOHPy is isonicotinic acid, has been synthesized and characterized. High quantum yields (> 0.5) and long excited-state lifetimes (0.3-10 micronseconds) in fluid solutions at room temperature were found for this complex, with remarkable emission sensitivity to microenvironment. This compound also displays highly polarized emission with a maximum anisotropy near 0.3 in the absence of rotational diffusion. This Re complex was conjugated to several biomolecules, including the proteins human serum albumin and bovine immunoglobulin G, as well as an amine-containing lipid. When bound to a protein or lipid, the decay time is near 3 microseconds and the quantum yield is approximately 0.12 in aqueous oxygenated solution at room temperature. This compound's unique spectral properties along with its conjugatability allowed us to utilize it as biomolecular probe in a variety of environments.

In-situ photochemical spectrofluorimetric detection of 9,10-anthraquinone-labeled bovine serum albumin

Bovine serum albumin (BSA) labeled with 9,10-anthraquinone (AQ) shows a greatly enhanced photochemical fluorometric activity compared with that of free AQ. The spectral characteristics of the photoreduction product of conjugated AQ was investigated and large blue shifts in the excitation and emission bands compared with those of free AQ were observed. The enhancement in the photochemical reactivity can be employed for sensitive detection of labeled BSA by a simple in-situ photochemical kinetic fluorimetric method. The kinetic behavior of the photochemical reaction and the effects of some experimental conditions were investigated. The calibration graph was linear over the range 0-1.8 x 10(-7) M BSA. The detection limit was 1.2 x 10(-10) M BSA and the relative standard deviation was 2.24% for the 1.42 x 10(-8) M BSA (n = 7).

In-situ photochemical spectrofluorimetric detection of 9,10-anthraquinone-labeled bovine serum albumin

Bovine serum albumin (BSA) labeled with 9,10-anthraquinone (AQ) shows a greatly enhanced photochemical fluorimetric activity compared with that of free AQ. The spectral characteristics of the photoreduction product of conjugated AQ were investigated and large blue shifts in the excitation and emission bands compared with those of free AQ were observed. The enhancement in the photochemical reactivity can be employed for sensitive detection of labeled BSA by a simple in-situ photochemical kinetic fluorimetric method. The kinetic behavior of the photochemical reaction and the effects of some experimental conditions were investigated. The calibration graph was linear over the range 0-1.8 x 10(-7) M BSA. The detection limit was 1.2 x 10(-10) M BSA and the relative standard deviation was 2.24% for 1.42 x 10(-8) M BSA (n = 7).

[Effect of vasopressin in the rostral ventrolateral medulla on pressor response induced by dPAG stimulation]

Experiments were performed on male SD rats anaesthetized with urethane (700 mg/kg) and chloralose (35 mg/kg). The results showed that mean arterial pressure (MBP) increased signifigantly and heart rate (HR) had no signifigant change by bilateral microinjection AVP(10 pmol/0.1 microliter/site) into the rostral ventrolateral medulla (rVLM), while both MBP and HR were not changed by application of an AVP-V1 receptor antagnoist. Microinjection of an AVP-V1 receptor antagonist into the bilateral rVLM inhibited partially the pressor response induced by midbrain defence area stimulation. The above results suggest that AVP in the rVLM can elevate MBP and midbrain defence area stimulation can cause pressor response. Both these effects are related to activation of AVP-V1 receptors in the rVLM.

Application of a novel fluorescence probe in the determination of nucleic acids

A novel fluorimetric method has been developed for rapid determination of DNA and RNA with hypocrellin A (HA) as a fluorescence probe, based on the fluorescence enhancement of HA in the presence of DNA or RNA. Maximum fluorescence is produced in the pH range 3.4-4.0, with maximum excitation and emission wavelengths at 470 and 600 nm, respectively. Under optimal conditions, the calibration graphs are linear over the range 0-200.0 ng cm-3 for calf thymus DNA and 13.0-200.0 ng cm-3 for yeast RNA, respectively. The corresponding detection limits are 5.0 ng cm-3 for calf thymus DNA and 13.0 ng cm-3 for yeast RNA. The relative standard deviation of six replicate measurements is 4.5% for 100 ng cm-3 calf thymus DNA. DNA could be determined in the presence of 20% m/m yeast RNA. The mechanism for the binding of HA to DNA is also studied.

Multiplexed DNA sequencing and diagnostics by hybridization with enriched stable isotope labels

A new DNA diagnostic and sequencing system has been developed that uses time-of-flight resonance ionization mass spectrometry (TOF-RIMS) to provide a rapid method of analyzing stable isotope-labeled oligonucleotides in form 1 sequencing by hybridization (SBH). With form 1, the DNA is immobilized on a nylon membrane and enriched isotope-labeled individual oligonucleotide probes are free to seek out complementary DNAs during hybridization. The major advantage of this new approach is that multiple oligonucleotides can be labeled with different enriched isotopes and can all be simultaneously hybridized to the genosensor matrix. The probes can then be simultaneously detected with TOF-RIMS with high selectivity, sensitivity, and efficiency. By using isotopically enriched tin labels, up to 10 labeled oligonucleotides could be examined in a single hybridization to the DNA matrix. Greater numbers of labels are available if rare earth isotopes are employed. In the present study, matrices containing three different DNAs were prepared and simultaneously hybridized with two different probes under a variety of conditions. The results show that DNAs, immobilized on nylon surfaces, can be specifically hybridized to probes labeled with different enriched in isotopes. Discrimination between complementary and noncomplementary sites of better than 100 was obtained in multiplexed samples. This new SBH method, which employs stable isotopic labels to locate target DNAs and TOF-RIMS to detect the labels, will be a very versatile and extensive multiplexing method.

[Effect of microinjection of adrenaline (E) into the rostral ventrolateral medulla on the parameters of the hemorrheology]

Experiments were performed on SD rats. It was found that hyperviscosity could be induced by restrained conscious rats. Microinjection of adrenaline (E) into the rostral ventrolateral medulla (rVLM) resulted in a facilitatory increase in blood viscosity, which was blocked by bilateral microinjection of alpha-adrenoceptor antagonist (phentola mine) into the same area, but not by beta-adrenocetor antagonist (propranolol). Pretreatment of rVLM area with 6-hydroxydopamine (6-OHDA) or microinjection of phentolamine abolished stress-induced hyperviscosity, while propranolol was without effect. Apparently the E caused increase of the blood viscosity or stress-induced hyperviscosity may be mediated by activation of alpha-adrenoceptor in the rVLM.

[Effect of acute hypoxia on blood catecholamine and whole blood platelet aggregation]

Experiments were performed on 250-300 g male Sprague-Dawley rats under urethane (700 mg/kg) and alpha-chloralose (35 mg/kg) anesthesia. Plasma catecholamine concentration and the whole blood platelet aggregation were measured during normoxia, acute hypoxia, reoxygenation, acute hypoxia immediately after bilateral adrenalectomy and acute hypoxia at the end of 15 and 30 min after bilateral adrenalectomy. The plasma adrenaline concentration and the whole blood platelet aggregation increased markedly (P < 0.01), while the plasma noradrenaline concentration tended to increase (P > 0.05) during acute hypoxia. The plasma adrenaline concentration and the whole blood platelet aggregation are capable of restoring to the normal level during reoxygenation. The plasma noradrenaline concentration did not change, while the plasma adrenaline concentration and the whole blood platelet aggregation decreased significantly (P < 0.001 or 0.05) during acute hypoxia for 15 min immediately after bilateral adrenalectomy. On the other hand, plasma adrenaline and noradrenaline were not detectable during acute hypoxia 30 min after bilateral adrenalectomy while the whole blood platelet aggregation deceased markedly (P < 0.01). When adrenaline (1 ng/ml) was added to the blood (in vitro), the whole blood platelet aggregation increased significantly (P < 0.01). All the above results indicate that acute hypoxia leads to increament of whole blood platelet aggregation and plasma adrenaline concentration due to release from the adrenal gland and the increament of the whole blood platelet aggregation may be partly mediated by increased plasma adrenaline.

[Effect of acute hypoxia on blood viscosity, red blood cell deformability and the left ventricular function in rats]

Experiments were performed on SD rats anaesthetized with urethane and chloralose. The left ventricular function and the parameters of hemorrheology during acute hypoxia were investigated. It was found that during acute hypoxia of 15 min, arterial blood gas value PaO2 decreased markedly. The parameters of the left ventricular function such as +/- dP/dtmax, Peak, HR, Vce40, Vmp, Vmax, L0 (CFU), decreased markedly either. At the same time, hyperviscosity was induced and red blood cell filtration (IF) increased. All these parameters recovered to normal control level after reoxygenation of 15 min. By intravenous injection of propranolol (0.5 mg/kg) and then hypoxia, the left ventricular function were suppressed markedly; and so were to the elevation of blood viscosity and IF. Preinjection of regitine (3 mg/kg) prior hypoxia has the same effect on the blood viscosity and IF. Acute hypoxia induced hyperviscosity and elevation of IF could be suppressed by destruction of carotid sinus region with phenol, but the left ventricular function decreased markedly. These results suggest that acute hypoxia induces hyperviscosity and decreases of red blood cell deformability and left ventricular function, which is probably mediated via the sympathetic nervous system and carotid sinus region.

[Inhibitory effect of diazepam or flurazepam on pressor response induced by the stimulation of midbrain in the rabbit]

Experiments were performed on 32 rabbits anaesthetized with alpha-chloralose and urethane, paralyzed with flaxidil and artificially ventilated. The pressor response was elicited by stimulation of dorsal part of midbrain periaqueductal gray (dPAG). Intravenous injection of diazepam (2 mg/kg) or intracerebroventricular application of flurazepam (2 mg/50 microliters) resulted in attenuation of the pressor response induced by the stimulation of midbrain. Bilateral microinjection of flurazepam (100 micrograms in 0.25 microliter) into rostral ventrolateral medulla (rVLM) depressed the pressor response to midbrain stimulation. Microinjection of flurazepam of the same dosage into caudal ventrolateral medulla (cVLM), however, had no depressant effect. Pretreatment with bicuculline in rVLM prevented the inhibitory effect of flurazepam on the pressor response. These results mentioned above suggest that diazepam or flurazepam inhibits the pressor response evoked by midbrain stimulation, and the effect may be mediated by the activation of the GABAA receptor in rVLM.

[Inhibitory effect of intraventricular administration of morphine on the hyperviscosity and elevation of blood pressure induced by stress in the rat]

Experiments were performed on 99 Wistar rats. It was found that hyperviscosity and elevation of blood pressure (BP) could be induced by hanging and restraining conscious rats with their four limbs tied on a frame. These effects were unaffected by bilateral vagotomy. By intravenous injection of propranolol or phentolamine, elevation of BP could be reduced, while stress-induced hyperviscosity could only be reduced by propranolol (i.v.). Stress-induced hyperviscosity and elevation of BP could be inhibited by electroacupuncture applied to the right hind leg or microinjection of morphine into 4th ventricle of the brain. On the other hand, if opiate receptor antagonist naloxone was given into the 4th-ventricle, the stress-induced hyperviscosity and elevation of BP could no longer be inhibited by electroacupuncture. It is suggested that the hyperviscosity and elevation of BP induced by hanging and restraining are mediated by excitatory cardiovascular sympathetic outflow with the result of activation of adrenoreceptors. Activation of the opiate receptors in the hindbrain may be responsible for decrease in stress-induced hyperviscosity and elevation of BP and for the inhibitory effect of electroacupuncture of the right hind leg on stress-induced hyperviscosity and elevation of BP.

Effects of electroacupuncture of "zusanli" acupoint on high blood pressure and blood hyperviscosity in stress rats

Elevation of blood pressure (BP) and blood viscosity (BV) was induced in unanesthetized Wistar rats by fixing and hanging. Electroacupuncture of "Zusanli" acupoint or microinjection of GABA (60 micrograms/10 microliters) into the IV ventricle of the brain could lower the high BP and BV induced by fixed-hanging, which could be blocked by a microinjection of GABAA receptor antagonist bicuculline (60 micrograms/10 microliters). The results showed that the depressant effect of electroacupuncture of "Zusanli" acupoint on high BP and blood hyperviscosity induced by fixed-hanging might be mediated by the activation of GABAA receptors in the brain.

[Influence of microinjection of bicuculline into ventrolateral medulla on the suppression of cardiac function induced by diazepam in rabbits]

Experiments were carried out on 48 rabbits anaesthetized with urethane (1 g/kg). The animals were immobilized with gallamine triethiodide and ventilated artificially. Both intravenous injection of diazepam (0.5 mg/kg) and intracerebroventricular injection of flurazepam (2 mg in 50 microliters) or gamma-aminobutyric acid (GABA) (300 micrograms in 50 microliters) decreased the peak value of left ventricular pressure area of cardiac force loop and dp/dtmax. These suppressive effects of diazepam and flurazepam were prevented by intracerebroventricular injection of picrotoxin (15 micrograms in 50 microliters) or microinjection of bicuculline (3 micrograms in 0.5 microliter) into bilateral rostral ventrolateral medulla (gamma VLM). The results suggest that the inhibitory effects of diazepam on cardiac function may be mediated by activation of GABA receptor in gamma VLM.

[Mechanism of depressing effect of diazepam on the blood pressure and on ventricular extrasystoles induced by hypothalamic stimulation in the rabbit]

Experiments were carried out on 62 rabbits anesthetized with urethane and chloralose and immobilized with gallamine triethiodide under artificial ventilation. Ventricular extrasystoles were induced by electrical stimulation of the hypothalamic defence area (HVE). Following intravenous administration of diazepam (0.5 mg/kg), the pressor response and HVE induced by electrical stimulation of the hypothalamus were attenuated, as blood pressure (BP) dropped. Bilateral microinjection of flurazepam (200 micrograms in 0.5 microliters) or GABA (3 micrograms in 0.5 microliters) into the rostral ventrolateral medulla (rVLM) resulted in a significant decrease in BP, and pressor response during hypothalamic stimulation as well as reduction in the amount of HVE. Bilateral microinjection of picrotoxin (7.5 micrograms in 0.5 microliters) into the rVLM facilitated HVE and increased BP. Microinjection of flurazepam, GABA of the same doses into the caudal ventrolateral medulla (cVLM), however, had no such effect. The depressant effect of intravenous injection of diazepam could be prevented by bilateral microinjection of GABA receptor antagonist bicuculline (3 micrograms in 0.5 microliters) or picrotoxin (7.5 micrograms in 0.5 microliters) into the rVLM. Whereas bilateral microinjection of atropine (0.25 micrograms in 0.5 microliters), scopolamine (0.15 micrograms in 0.5 microliters), naloxone (0.5 micrograms in 0.5 microliters), strychnine (1 microgram in 0.5 microliters) into the rVLM no depressant effect was observed. These results suggest that the depressant effect of diazepam on BP, the pressor response and HVE may be mediated by activation of the GABA receptors in the rVLM.