Modelling the medium-term dynamics of SARS-CoV-2 transmission in England in the Omicron era

England has experienced a heavy burden of COVID-19, with multiple waves of SARS-CoV-2 transmission since early 2020 and high infection levels following the emergence and spread of Omicron variants since late 2021. In response to rising Omicron cases, booster vaccinations were accelerated and offered to all adults in England. Using a model fitted to more than 2 years of epidemiological data, we project potential dynamics of SARS-CoV-2 infections, hospital admissions and deaths in England to December 2022. We consider key uncertainties including future behavioural change and waning immunity and assess the effectiveness of booster vaccinations in mitigating SARS-CoV-2 disease burden between October 2021 and December 2022. If no new variants emerge, SARS-CoV-2 transmission is expected to decline, with low levels remaining in the coming months. The extent to which projected SARS-CoV-2 transmission resurges later in 2022 depends largely on assumptions around waning immunity and to some extent, behaviour, and seasonality.

Potential implementation strategies, acceptability, and feasibility of new and repurposed TB vaccines

Recently, two Phase 2B tuberculosis vaccine trials reported positive efficacy results in adolescents and adults. However, experience in vaccinating these age groups is limited. We identified potential implementation strategies for the M72/AS01E vaccination and BCG-revaccination-like candidates and explored their acceptability and feasibility. We conducted in-depth semi-structured interviews among key decision makers to identify implementation strategies and target groups in South Africa, India, and China. Thematic and deductive analysis using a coding framework were used to identify themes across and within settings. In all three countries there was interest in novel TB vaccines, with school-attending adolescents named as a likely target group. In China and India, older people were also identified as a target group. Routine vaccination was preferred in all countries due to stigma and logistical issues with targeted mass campaigns. Perceived benefits for implementation of M72/AS01E were the likely efficacy in individuals with Mycobacterium tuberculosis (Mtb) infection and efficacy for people living with HIV. Perceived challenges for M72/AS01E included the infrastructure and the two-dose regimen required. Stakeholders valued the familiarity of BCG but were concerned about the adverse effects in people living with HIV, a particular concern in South Africa. Implementation challenges and opportunities were identified in all three countries. Our study provides crucial information for implementing novel TB vaccines in specific target groups and on country specific acceptability and feasibility. Key groups for vaccine implementation in these settings were identified, and should be included in clinical trials and implementation planning.

Vaccination coverage determinants in low uptake areas of China: a qualitative study of provider perspectives in Sichuan, Guangdong, and Henan Provinces

China’s immunization programme is relatively strong, with latest WHO-UNICEF monitoring rates for 2019 showing national vaccination coverage over 90%. However, vaccination coverage is heterogeneous, varying across geographic regions, rural–urban communities, and sub-populations. We conducted a qualitative study from a critical realist perspective, analyzing semi-structured interviews with 26 vaccination providers in three provinces, selected to represent regional socioeconomic disparities across Eastern, Central, and Western China. We analyzed data thematically, using deductive and inductive coding. Providers reported vaccination coverage in their areas had increased significantly, but remained lower among migrant and left-behind children. Main coverage determinants were child-related (i.e. gender, number, health status), caregiver-related (i.e. socioeconomic status, role, education level, ethnicity), institution-related (i.e. vaccinator numbers, information system, appointment process), and system-related (i.e. vaccine supply, intersectoral cooperation, vaccine ‘hesitancy’). Potentially effective measures to promote vaccination coverage included using routine maternal and child health-care visits for catch-up vaccination, providing additional health education, conducting follow-up family visits by village doctors, and requiring vaccination verification at school enrollment. This is the first qualitative study to examine potential determinants of low vaccination coverage in these areas of China. Findings can inform policies to strengthen the role of schools, develop the national immunization information system, and promote appointment apps. More consideration is needed to improve service quality and eliminating inequities, such as strengthening health education and service provision for migrant and left-behind children.

Regional-based within-year seasonal variations in influenza-related health outcomes across mainland China: a systematic review and spatio-temporal analysis

BACKGROUND

China experiences large variations in influenza seasonal activity. We aim to update and improve the current understanding of regional-based within-year variations of influenza activity across mainland China to provide evidence for the planning and optimisation of healthcare strategies.

METHODS

We conducted a systematic review and spatio-temporal meta-analysis to assess regional-based within-year variations of ILI outpatient consultation rates, influenza test positivity rates amongst both ILI outpatients and SARI inpatients, and influenza-associated excess mortality rates. We searched English and Chinese databases for articles reporting time-series data on the four influenza-related outcomes at the sub-national and sub-annual level. After synthesising the data, we reported on the mean monthly rate, epidemic onset, duration, peak and intensity.

RESULTS

We included 247 (7.7%) eligible studies in the analysis. We found within-year influenza patterns to vary across mainland China in relation to latitude and geographic location. High-latitude provinces were characterised by having short and intense annual winter epidemics, whilst most mid-latitude and low-latitude provinces experience semi-annual epidemics or year-round activity. Subtype activity varied across the country, with A/H1N1pdm09 and influenza B occurring predominantly in the winter, whereas A/H3N2 activity exhibited a latitudinal divide with high-latitude regions experiencing a winter peak, whilst mid and low-latitude regions experienced a summer epidemic. Epidemic onsets and peaks also varied, occurring first in the north and later in the southeast. We found positive associations between all influenza health outcomes. In addition, seasonal patterns at the prefecture and county-level broadly resembled their wider province.

CONCLUSIONS

This is the first systematic review to simultaneously examine the seasonal variation of multiple influenza-related health outcomes at multiple spatial scales across mainland China. The seasonality information provided here has important implications for the planning and optimisation of immunisation programmes and healthcare provision, supporting the need for regional-based approaches to address variations in local epidemiology.

Public Attitudes and Factors of COVID-19 Testing Hesitancy in the United Kingdom and China: Comparative Infodemiology Study

Background

Massive community-wide testing has become the cornerstone of management strategies for the COVID-19 pandemic.

Objective

This study was a comparative analysis between the United Kingdom and China, which aimed to assess public attitudes and uptake regarding COVID-19 testing, with a focus on factors of COVID-19 testing hesitancy, including effectiveness, access, risk perception, and communication.

Methods

We collected and manually coded 3856 UK tweets and 9299 Chinese Sina Weibo posts mentioning COVID-19 testing from June 1 to July 15, 2020. Adapted from the World Health Organization's 3C Model of Vaccine Hesitancy, we employed social listening analysis examining key factors of COVID-19 testing hesitancy (confidence, complacency, convenience, and communication). Descriptive analysis, time trends, geographical mapping, and chi-squared tests were performed to assess the temporal, spatial, and sociodemographic characteristics that determine the difference in attitudes or uptake of COVID-19 tests.

Results

The UK tweets demonstrated a higher percentage of support toward COVID-19 testing than the posts from China. There were much wider reports of public uptake of COVID-19 tests in mainland China than in the United Kingdom; however, uncomfortable experiences and logistical barriers to testing were more expressed in China. The driving forces for undergoing COVID-19 testing were personal health needs, community-wide testing, and mandatory testing policies for travel, with major differences in the ranking order between the two countries. Rumors and information inquiries about COVID-19 testing were also identified.

Conclusions

Public attitudes and acceptance toward COVID-19 testing constantly evolve with local epidemic situations. Policies and information campaigns that emphasize the importance of timely testing and rapid communication responses to inquiries and rumors, and provide a supportive environment for accessing tests are key to tackling COVID-19 testing hesitancy and increasing uptake.

Caregiver and service provider vaccine confidence following the Changchun Changsheng vaccine incident in China: A cross-sectional mixed methods study

INTRODUCTION

The Changchun Changsheng Vaccine Incident (CCVI) occurred mid-2018 and involved irregularities in the manufacture and quality control of diphtheria-tetanus-acellular-pertussis and rabies vaccines. This study investigates vaccine confidence amongst Chinese caregivers and vaccination-service providers (VSPs) six months after the CCVI.

METHODS

Quantitative surveys were conducted in January 2019 with 2124 caregivers of children and 555 VSPs in three areas in China. The proportions of respondents who agreed to the four statements from the Vaccine Confidence Index™ were used to measure vaccine confidence. Descriptive and univariate analyses were performed to study the level of vaccine confidence. Semi-structured interviews were conducted with 48 caregivers, 43 VSPs and 9 immunization program managers. Interviews were analyzed thematically using a combination of deductive and inductive coding. Media surveillance was conducted to monitor public responses to the CCVI.

RESULTS

Media surveillance indicated that public attention to vaccine-related issues increased sharply immediately post-CCVI but declined rapidly thereafter. Six months post-CCVI, 96.0% of caregivers and the same proportion of VSPs reported that vaccination was important and compatible with their religious beliefs. 82.7% and 88.2% of caregivers agreed that vaccines were safe and effective. 92.8% and 94.6% of VSPs agreed that vaccines were safe and effective. Both caregivers and VSPs reported an immediate decline in vaccine confidence post-CCVI. In most cases this trust was regained over time following government and public health responses, however some people remained hesitant about vaccinating their children. Many VSPs were overwhelmed by consultations, workload and psychological pressure after the CCVI.

CONCLUSION

After an initial decline, vaccine confidence recovered to pre-incident levels six months after the CCVI. However, some caregivers moved from the higher to the lower end of the vaccine confidence spectrum, pointing to the need to promote the acceptance of vaccination especially given the need for new vaccines to control the coronavirus epidemic.

[Relations between high risk sexual behavior and HIV infection among men who have sex with men in ways of meeting male partners]

Objective: To understand the relations between high risk sexual behavior and HIV infection among MSM in ways of finding male partners in Ningbo. Methods: A cross-sectional study was conducted in Ningbo between April and November in 2018. Data related to socio-demographics, ways of finding male partners, adoption of gay apps and sexual behaviors were collected by snowball method. Blood samples were drawn for HIV antibody testing. Classified data was evaluated by chi-square test. Related factors on HIV infection were analyzed by multivariate logistic regression. Results: A total of 735 participants were included in this study. Ways of finding male partners would through gay apps (60.8%, 447/735), QQ/Wechat (32.3%, 237/735) and gay-places (6.9%, 51/735). Related information on high risk sexual behavior and HIV infection among gay apps users were found as: 16.8%(75) had sexual behavior once per week in the past 6 months, 41.8% (187/447) had multiple sexual partners, 12.1% (54/447) had unprotected anal intercourse in the last time, 52.3% (234/447) having had unprotected anal intercourse in the past 6 months. The overall HIV prevalence rate was 12.1%(54/447). Among the HIV cases who got infected within the two years, 68.6%(24/35) of them had used gay apps for less than two years. Results from the, multivariate logistic regression analysis showed that gay apps users were more susceptible to infected HIV than those who used the QQ/Wechat (OR=3.03, 95%CI: 1.30-7.07). Conclusions: Gay apps was popularly known among the Ningbo MSM, and was associated with the high risk sexual behaviors and HIV infection. HIV control and prevention programs should be strengthened in the MSM population who used the gay apps. Related surveillance and intervention programs for MSM, who use the gay apps, need to be further reinforced.

[Clinical analysis of orbital and periorbital abscess in 17 patients]

Objective: To discuss the etiology, clinical features and treatment principles of the orbital and periorbital abscess. Methods: A retrospective case series of 17 cases with orbital and periorbital abscess between July 2010 and November 2015 were conducted. All patients(,) clinical data including medical history, etiology, abscess location, paranasal sinus involvement, eye involvement, microbiological test results, imaging features, treatment and prognosis were summarized and analyzed. Results: In all 17 patients, there were 10 males and 7 females with age from 3.0 to 71.0 years (the average age was 33.9 years).Eight patients(,) bacterial cultures of the pus and secretion were positive in all 17 patients. Orbital and periorbital abscess patients could manifest decreased vision, redness and swelling of eyelid, conjunctival congestion and edema, ocular motility disorders, displacement of eyeball, increased orbital pressure, abscess rupture etc. CT showed us the soft tissue mass, accompanied with sinusitis or paranasal sinus mass. MR performed with the long T(1) and T(2) signals. The signals of the abscess cavity were not uniform. For the etiology,11 cases were secondary to sinusitis, including 1 case of diabetes; 2 cases with orbital fractures.One case was secondary to orbital fracture repairment surgery. One case was secondary to the remnant of sequestrum and foreign bodys in the wound after repairment surgery. One case was injured by the hard object. One case was secondary to paranasal sinuses large B-cell lymphoma. One case had diabetic history and the blood sugar was controlled unstablly. For the treatment, 7 cases were treated by the drainage surgery which was performed via the sinus with endoscopic and abscess resection performed via the skin.Two cases were treatment by the abscess resection only.One case was treated by the drainage surgery performed via the sinus with endoscopic only. Six cases were treated by the drainage surgery performed via the skin. One case was only administered intravenous antibiotic. Sixteen cases acquired well prognosis without serious complications except 1 case which occurred central retinal artery and vein occlusion. Conclusions: The orbital and periorbital abscess is mainly a complication of paranasal sinus infection, or secondary to trauma, surgery, tumor, etc; Orbital and periorbital abscess always manifest inflammatory neoplastic clinical features, the key of the diagnosis is to make sure the etiology; Incision and drainage of the abscess is the main treatment method when necessary. We can do the surgery with other departments to avoid the occurrence of serious complications.(Chin J Ophthalmol, 2017, 53: 588-593).

[Clinical analysis of patients with orbital nonspecific inflammatory response diseases whose CT or MR images show enlargement of the infraorbital nerves]

Objective: To discuss the clinical features, imaging features, pathological patterns, treatment principles and prognosis of the orbital nonspecific inflammatory response diseases patients whose CT or MR images show enlargement of the infraorbital nerves. Methods: A retrospective case series study. Seven orbital disease patients who were treated at Tianjin Medical University Eye Hospital between March 2013 and May 2017 were included. All patients, imaging pictures showed enlargement of the infraorbital nerve. The medical histories, clinical featuers, imaging features, pathologies, serological examinations, therapeutic processes and prognosis were collected and analyzed. Results: The 7 patients included 4 males and 3 females aged from 55 to 68 years (the average age was 60). Bilateral involvement was present in 5 of 7 patients. The main clinical manifestations include proptosis, increasing of orbital pressure, impairment of visual functions, reduction in ocular motility, facial sensation, periocular ache, involvement of lymph node and salivary gland, etc. CT results showed enlargement of infraorbital nerve, accompanied with or without the destruction of bone. The inflammatory response may involve with extraocular muscles and lacrimal glands, or were shown as lesions with irregular shape and blurred borders. The MR images generally showed equal T(1) and equal T(2) signal, accompanied with evident enlargement of the infraorbital nerve. Of all the 7 patients, 6 underwent operation, and the pathology confirmed that 2 of the 6 were involved with inflammatory pseudotumors and the rest 4 were involved with IgG4-related ophthalmic disease (IgG4-ROD). The level of IgG4 in the serum were detected for 4 patients, the results of 3 were high and the other was normal. Of all the 7 patients,1 patient underwent conservative treatment, but disease recurred for several times, and the serum IgG4 level for the patient was higher than normal;1 inflammatory pseudotumor patient was cured completely only by surgery, and has a favourable prognosis; 1 IgG4-ROD patient accepted glucocorticoid, surgery, radiotherapy and chemotherapy, but disease recurred several times; The rest of the patients accepted glucocorticoid and operation, 2 were sensitive to glucocorticoid, 2 were not sensitive, and 1 involved with recurrence. Conclusions: If orbital nonspecific inflammation response was accompanied with enlargement of infraorbital nerve, it is suggested that patient is more likely to be involved with IgG4-ROD;Pathology and serological tests can be used for the diagnosis of IgG4-ROD, however treatment effect appears to be poor for most patients, and patients prone to relapse. (Chin J Ophthalmol, 2018, 54: 515-519).

[Bone marrow-derived fibrocytes and thyroid-associated opthalmopathy]

Thyroid-associated opthalmopathy(TAO) is a common autoimmune syndrome affecting the thyroid and orbit, which can result in the fibrosis of extraoular muscles and hyperplasia of adipose tissue. Advanced TAO patients could even lose vision caused by cornea ulcer and congestion of optic nerve from expansion of the extraocular muscles and orbit fat. Currently, there are no therapies shown to prevent it, because its cellular and molecular mechanisms are not clear. Some studies have recently implicated bone marrow-derived fibroblast-like, called fibrocytes are involved in the pathogenesis of TAO. We reviewed and summarized the research advances of TAO and also the relationship between the fibrocytes and pathogenesis of TAO in the paper. (Chin J Ophthalmol, 2017, 53: 470-473).

[The value of DCE-MRI in assessing the course of thyroid associated ophthalmopathy]

Objective: To explore the feasibility of the semi-quantitative rectus extraocular muscle (EOM) parameters of dynamic contrast-enhanced magetic resonance imaging (DCE-MRI) in assessing the clinical course of thyroid associated ophthalmopathy (TAO). Methods: It was a retrospective case series study. A total of 136 cases of TAO were recruited from March 2011 to October 2012 in the Tianjin the first center hospital including 63 males and 72 females, aged 24.0-65.0 years, with an average age of (40.5±10.9) years. Forty healthy volunteers were recruited as control group (CG). According to clinical activity score (CAS), all TAO patients were divided into 2 groups, activity group (AG) and inactivity group (IAG). MRI and DCE-MRI orbit scan were performed in each subject. Drew time-intensity curves (TIC) by Siemens 3.0 MR (syngo) post-processing workstation. The semi-quantitative parameters of DCE-MRI were calculated. The semi-quantitative paramters based on TIC include early enhancement coefficient (EEC), maximum enhancement coefficient (Emax) and wash-out coefficient (WC(5min)). Kruskal-Wallis H rank test was used for comparing signal intensity among 3 groups, and Nemenyi test for pairwise comparison between groups. The DCE-MRI parameters (EEC, Emax, WC(5 min)) among groups were compared by one-way ANOVA, and Bonferroni t test is for pairwise comparison between groups. The diagnostic value of mean EEC, mean Emax, WC(5min) for assessment of the clinical course in TAO was analyzed by ROC curve. Results: There were significant difference in signal intensity (SI) of rectus EOM on T(2)WI among CG, AG and IAG, which is significantly different in 88 cases of AG including 45 cases of high intensity 51.1%, 23 cases of moderate intensity 26.1%, and 20 cases of low intensity 22.7%,compared with CG and IAG. EEC (P<0.05), Emax and WC5min values of rectus EOM of TAO group were significantly lower than those of CG(P<0.05), which values of rectus EOM of TAO active group of EEC are 0.63±0.06、0.61±0.05、0.56±0.09、0.57±0.09, and values of rectus EOM of TAO inactive group of EEC are 0.49±0.05、0.50±0.08、0.57±0.10、0.55±0.09. The values of rectus EOM of TAO active group of Emax are 1.35±0.09、1.28±0.09、1.21±0.17、1.25±0.10, and the values of rectus EOM of TAO inactive group of Emax are 1.04±0.06、1.05±0.10、1.20±0.19、1.16±0.11. The values of rectus EOM of TAO active group of WC(5 min) are 0.13±0.03、0.13±0.03、0.13±0.06、0.13±0.03 and the values of rectus EOM of TAO inactive group of WC5min are 0.08±0.02、0.79±0.03、0.11±0.06、0.09± 0.03. EEC (χ(2)=9.20, P<0.05), Emax and WC(5min) values of rectus EOM of TAO group were significantly lower than those of CG (P<0.05). EEC, Emax and WC(5min) values of medial rectus and inferior rectus EOM of IAG were significantly lower than those of AG(P<0.05). WC(5min) values of superior rectus EOM of IAG were significantly lower than those of AG (P<0.05). There were no differences in EEC and Emax values of lateral rectus and superior rectus EOM between IAG and AG (P>0.05). There were no differences in WC(5min) values of lateral rectus EOM between IAG and AG (P>0.05). The area under the curve (AUC) were 0.771, 0.879, 0.898 for mean EEC, mean Emax, and mean WC(5min), respectively. Conclusion: The semi-quantitative paramters of DCE-MRI can show the clinical activity of TAO patients and can be considered as the quantitative index of TAO activity staging. (Chin J Ophthalmol, 2017, 53: 430-435).

Hybrid biofilm-membrane bioreactor (Bf-MBR) for minimization of bulk liquid-phase organic substances and its positive effect on membrane permeability

Four biofilm membrane bioreactors (Bf-MBRs) with various fixed carrier volumes (C:M) were operated in parallel to investigate the effect of attached-growth mode biomass involvement to the change of liquid-phase organics characteristics and membrane permeability, by comparing with conventional MBR. The experiments displayed that C:M and co-existence of biofilm with suspended solids in Bf-MBRs resulted in slight difference in pollutants removal effectiveness, and in rather distinct biomass properties and bacterial activities. The membrane permeability and specific resistance of bulk suspension of Bf-MBRs related closely with the liquid-phase organic substance, including soluble microbial products (SMP) and biopolymer cluster (BPC). Compared with conventional MBR, Bf-MBR with proper C:M had a low total biomass content and food-chain, where biofilm formation and its dominance affected liquid-phase organics, especially through reducing their content and minimizing strongly and weakly hydrophobic components with small molecular weight, and thus to mitigate membrane fouling significantly.

Immune protective mechanism of rMOMP protein ophthalmic vaccine regarding intraocular hypertension and retinal optic nerve injury in rats

The aim of this study was to explore the immune protective mechanism of rMOMP protein vaccine in intraocular hypertension and retinal optic nerve injury in rats. The rMOMP protein ophthalmic vaccine was prepared and quality-controlled. Sixty normal adult SD rats were randomly divided into two groups to establish a chronic ocular hypertension model and an optic nerve injury model. The model rats were vaccinated with rMOMP-CS ophthalmic vaccine. Fluorogold retrograde tracing was used to observe retinal ganglion cells, and an immunofluorescence method to determine the expression of retinal GAP43, CD3, BDNF, and GDNF. rMOMP protein ophthalmic vaccine met the requirements for medicinal use. The number of retinal ganglion cells (RGCs) of the rMOMP-CS group in the chronic ocular hypertension model was significantly higher than that of the CS group (P < 0.05). The count of RGCs of the rMOMP-CS group in the optic nerve clamping injury model was significantly higher than that of the CS group (P < 0.01). Thus, rMOMP protein ophthalmic vaccine can induce an increase in the expression of retinal neurotrophic factors, thereby exerting a protective effect on damaged retinal optic nerve.

Investigation of the shape change of bio-flocs and its influence on mass transport using particle image velocimetry

In this laboratory study, an advanced flow visualization technique - particle image velocimetry (PIV) - was employed to investigate the change of shape of activated sludge flocs in water and its influence on the material transport characteristics of the flocs. The continuous shape change of the bio-flocs that occurred within a very short period of time could be captured by the PIV system. The results demonstrate that the fluid turbulence caused the shift of parts of a floc from one side to the other in less than 200 ms. During the continuous shape change, the liquid within the floc was forced out of the floc, which was then refilled with the liquid from the surrounding flow. For the bio-flocs saturated with a tracer dye, it was shown that the dye could be released from the flocs at a faster rate when the flocs were swayed around in water. The experimental results indicate that frequent shape change of bio-flocs facilitates the exchange of fluid and materials between the floc interior and the surrounding water. This mass transfer mechanism can be more important than molecular diffusion and internal permeation to the function and behavior of particle aggregates, including bio-flocs, in natural waters and treatment systems.

Stabilization of source-separated urine by biological nitrification process: treatment performance and nitrite accumulation

A laboratory study on nitrification of high-strength source-separated urine was conducted by means of sequencing batch reactors (SBR) and membrane bioreactors (MBR). The highest influent ammonia concentration for SBR and MBR reached more than 2,400 and 1,000 mg N/L, while the maximum pH was about 9 and 8.9, respectively. The ammonia oxidizing efficiency in both SBRs and MBRs was around 50%, which was restrained mainly by the deficiency of alkalinity in bulks. Meanwhile, the nitrite accumulation did also dominate in these two systems, and the major factor to inhibit the nitrite oxidization was thought to be the high free ammonia and free nitrous acid content in bulks. Hence, an ammonia nitrite solution was achieved with concentration ratio of 1:1; after that ammonia oxidation was restrained owing to the deficiency of alkalinity in urine. The temperature and influent ammonia content have no great influence on the nitrification process in both kinds of bioreactors. The nitrification can be progressed under a solids retention time (SRT) longer than 30 d; however, termination of ammonia oxidization was observed as the SRT fell below 20 d. The nitrifier biomass showed an excellent settleability, such that the suspended solids (SS) in effluent was of a low average, about 60 mg/L. This study on the stabilization of human urine will be useful to understand the process of urine separation from source.

Evaluation of the importance of various operating and sludge property parameters to the fouling of membrane bioreactors

A single-fibre microfiltration system was employed to investigate the importance of various operating and sludge property parameters to the membrane fouling during sludge filtration. The sludge was obtained from a submerged membrane bioreactor (SMBR). A series of comparative and correlative filtration and fouling tests were conducted on the influence of the operating variables, sludge properties and the liquid-phase organic substances on the membrane fouling development. The test results were analysed statistically with Pearson's correlation coefficients and the stepwise multivariable linear regression. According to the statistical evaluation, the membrane fouling rate has a positive correlation with the biopolymer cluster (BPC) concentration, sludge concentration (mixed liquor suspended solids, MLSS), filtration flux and viscosity, a negative correlation with the cross-flow velocity, and a weak correlation with the extracellular polymeric substances and soluble microbial products. BPC appear to be the most important factor to membrane fouling development during the sludge filtration, followed by the filtration flux and MLSS concentration. The cross-flow rate also is important to the fouling control. It is argued that, during membrane filtration of SMBR sludge, BPC interact with sludge flocs at the membrane surface to facilitate the deposition of the sludge cake layer, leading to serious membrane fouling.

A membrane bioreactor for an innovative biological nitrogen removal process

A hybrid system has been developed for biological nitrogen removal through nitrification-denitrification. The system includes an aerobic tank and an anoxic tank with an intermediate sludge settler connected to a membrane bioreactor (MBR) with a submerged 0.4 microm hollow-fiber membrane module. The laboratory system has a total working volume of 6.5 L treating a glucose-based synthetic wastewater. The experimental results demonstrate that the new process is highly effective for simultaneous organic and nitrogen removal. During the stationary operation, a sludge SS (suspended solids) concentration of 6 g/L or higher can be maintained in the reactors. The system has a COD (chemical oxygen demand) loading rate of up to 2,100 mg/L-d and a total nitrogen loading rate of up to 170 mg N/L-d. More than 95% COD can be degraded, and the total nitrogen removal efficiency can be 90% or higher as the nitrogen is reduced from 100 to around 7.5 mg/L. A high quality effluent is produced with a SS of less than 1 mg/L. With the MBR, organic degradation, nitrogen removal and sludge-liquid separation can be well achieved within a short HRT of about 10 hr.

Cloning and characterization of a novel gene (C17orf25) from the deletion region on chromosome 17p13.3 in hepatocelular carcinoma

Using a combination of hybridization of PAC to a cDNA library and RACE technique, we isolated a novel cDNA, designated as C17orf25 (Chromosome 17 open reading frame 25, previously named it HC71A), from the deletion region on chromosome 17p13.3. The cDNA encodes a protein of 313 amino acids with a calculated molecular mass of 34.8 kDa. C17orf25 is divided into 10 exons and 9 introns, spanning 23 kb of genomic DNA. Northern blot analysis showed that the mRNA expression of C17orf25 was decreased in hepatocellular carcinoma samples as compared to adjacent noncancerous liver tissues from the same patients. The transfection of C17orf25 into the hepatocellular carcinoma cell SMMC7721 and overexpression could inhibit the cell growth. The above results indicate that C17orf25 is a novel human gene, and the cloning and preliminary characterization of C17orf25 is a prerequisite for further functional analysis of this novel gene in human hepatocellular carcinoma.

Role of excitatory amino acid transporter 1 in neonatal rat neuronal damage induced by hypoxia-ischemia

The role of excitatory amino acid transporter 1 in neonatal rat neuronal damage was studied following hypoxia-ischemia. To induce hypoxia-ischemia injury, rats on postnatal day 7 were exposed to 8 % oxygen for 2 h following unilateral common carotid artery ligation. According to brain damage scoring based on Cresyl Violet staining, the neuronal damage time-dependently changed in the ischemic regions following hypoxia-ischemia. Immunohistochemical studies showed that excitatory amino acid transporter 1 expression was mainly observed in the cerebral cortex ipsilateral to common carotid artery ligation and markedly increased at 24 h and 48 h following hypoxia-ischemia. Combined with confocal laser scanning microscopic analysis, double staining showed that excitatory amino acid transporter 1 positive staining appeared in neurons as well as astrocytes after hypoxia-ischemia. Most excitatory amino acid transporter 1 positive staining cells exhibited regular morphological characteristics and only a few were double-stained by terminal deoxynucleotidyl transferase-mediated deoxyuridinetriphosphate nick-end labeling. Down-regulation of excitatory amino acid transporter 1 expression by intraventricular administration of specific antisense oligonucleotide exacerbated neuronal damage in hypoxia-ischemia brain. These results suggest that the increase of excitatory amino acid transporter 1 expression may be involved in a pathophysiological process of hypoxia-ischemia brain damage and may reflect a self-compensative mechanism for protecting neurons from further injury.

Trichlorfon induces spindle disturbances in V79 cells and aneuploidy in male mouse germ cells

In order to assess the effects of trichlorfon on cell division and on aneuploidy induction, we conducted an in vitro assay for spindle disturbances using V79 cells and an in vivo assay for aneuploidy induction in meiosis of male mice using multicolour fluorescence in situ hybridization (FISH) with epididymal sperm. In the in vitro assay, the chemical caused a concentration-dependent increase in the incidence of initial and full c-mitoses in the dose range 40-120 microg/ml trichlorfon. The mitotic index (MI) was decreased between 40 and 100 microg/ml trichlorfon, whereas at 120 microg/ml the MI was back to the control level, coinciding with the dramatic increase in c-mitoses. The results confirm that trichlorfon is a potent spindle poison in V79 cells. In the in vivo multicolour FISH assay, administration of trichlorfon to male mice at single doses of 200, 300 and 405 mg/kg caused a dose-dependent increase of the frequencies of disomic sperm (0.068, 0.074 and 0.134%, respectively) compared with the corresponding controls (0.046, 0.042 and 0.056%, respectively). The prevalence of X-X-8 and Y-Y-8 sperm suggests that trichlorfon affected chromosome segregation predominantly during the second meiotic division. Diploid sperm were not induced by trichlorfon treatment, indicating that no meiotic block occurred. It is concluded that trichlorfon is a potent spindle poison in V79 cells and induces aneuploidy in mouse spermatocytes during meiosis.

[Melatonin decreases the release of amino acid transmitters in hypoxic rat cortical slice]

To study the effect of melatonin on changes in amino acid release following hypoxic stimulation, a RP-HPLC fluorometric method was used to measure the content of amino acids in the culture medium of rat brain slices. Hypoxic condition was instituted by a gas of 91.6% N2 and 8.4% O2. The results showed that the contents of amino acids, including aspartate, glutamate, glutamine, glycine, taurine and GABA, in the medium were significantly increased to 240.4%, 334.3%, 200.6%, 210.4%, 168.6% and 263.9%, respectively (P < 0.01 vs control) by 30 min hypoxic incubation. Melatonin can significantly reduce the increase of aspartate and glutamate, to 55.1% and 57.0% of the hypoxic group.

Protective effect of melatonin on injuried cerebral neurons is associated with bcl-2 protein over-expression

AIM

To study the protective effect of melatonin against neuronal injury and the possible roles of alteration in the expression of bcl-2 and bax following brain ischemia.

METHODS

Brain ischemia was induced by left middle cerebral artery occlusion (MCAO) for 60 min in rats. Brain damage was evaluated by the infarct area and the neuronal cell counting. The expression of bcl-2 and bax was analyzed by immunohistochemical method.

RESULTS

Melatonin decreased the infarct area and prevented the neuronal death after 24-h reperfusion following 1-h MCAO. Melatonin given before the ischemia enhanced the expression of bcl-2 in the penumbra area and had no significant effect on the expression of bax.

CONCLUSION

Melatonin effectively attenuated ischemic brain injury and increased the expression of neuronal bcl-2 in the ischemic brain, indicating that the protective effect of melatonin was associated with up-regulation of bcl-2 in ischemia-induced neuronal death.

Intraventricular vascular endothelial growth factor antibody increases infarct volume following transient cerebral ischemia

AIM

To clarify the role of vascular endothelial growth factor (VEGF) in neuronal damage induced by cerebral ischemia.

METHODS

Expression of VEGF in adult rat brain was measured by immunohistochemistry. Transient middle cerebral artery occlusion (MCAO) model was induced by placing a nylon thread in the lumen of the internal carotid artery. The infarct volume was shown with 2,3,5-triphenyltetrazolium chloride (TTC) staining and quantitated by computer image analyzer with and without VEGF antibody treatment.

RESULTS

VEGF expression was widely distributed in neuronal cells besides vascular endothelial cells, and the neuronal distribution of VEGF was specific. After intraventricular treatment with VEGF antibody (0.1 g.L-1 daily, for 7 d following the ischemia), infarct volume in the antibody treatment was increased versus vehicle-treated rats [(21.6 +/- 2.7 vs 16 +/- 6) mm3, P < 0.05] respectively.

CONCLUSION

Intraventricular injection of VEGF antibody increased the infarct volume after focal cerebral ischemia in rats, suggesting that expression of neuronal VEGF may be one of neuronal protective mechanisms.

Effect of melatonin on production of hydroxyl radical and lactate dehydrogenase during hypoxia in rat cortical slices

AIM

To study the effect of melatonin on the production of hydroxyl radical (.OH) and lactate dehydrogenase (LDH) following hypoxia in cortical slice.

METHODS

Cortical slice was incubated with artificial cerebrospinal fluid (ACSF) in tube. Hypoxia was achieved by substituting 91.6% N2 and 8.4% O2. The salicylate trapping method was used to measure hydroxyl radicals generated. The content of LDH in medium after hypoxia was measured by International Federation of Clinic Chemistry (IFCC) method.

RESULTS

The contents of dihydroxybenzoic acid (DHBA) were increased significantly during hypoxia and reoxygenation in cortical slice. The production of DHBA in reoxygenation was decreased concentration-dependently by melatonin, but not during hypoxia 30 min. The release of LDH during hypoxia was steadily elevated and melatonin decreased the content of LDH after hypoxia.

CONCLUSION

Melatonin decreased the injury and production of .OH after hypoxia.

Hypoxia-ischemia altered expression of glutamate transporter EAAT1 in neonatal rat brain

AIM

To observe altered expression of glutamate transporter EAAT1 after hypoxia-ischemia (H-I) in newborn rat brain.

METHODS

Expression levels of EAAT1 were detected with immunohistochemistry method.

RESULTS

EAAT1 was a little expressed in cerebral cortex at sham-operated group [(36 +/- 10) cells/slice]. Its expression in cerebral cortex increased at 24 h and 48 h following H-I [(314 +/- 162) cells/slice and (431 +/- 149) cells/slice, respectively], and recovered to control level at 72 h following H-I [(52 +/- 8) cells/slice]. The expression of EAAT1 in the ipsilateral cortex to common carotid artery (CCA) ligation was higher than that in the contralateral cortex.

CONCLUSION

After H-I, the expression of EAAT1 had a temporal change in cerebral cortex of newborn rat, and was mainly located in the ipsilateral cortex to CCA ligation.

Effect of dextromethorphan, a NMDA antagonist, on DNA repair in rat photochemical thrombotic cerebral ischemia

Photochemical thrombotic ischemia model was used to study the possible roles of excision repair cross-complementing group 6 (ERCC6), a DNA repair gene, in the neuroprotection of dextromethorphan (DM), a NMDA antagonist, in ischemic brain injury. The results showed that no obvious ERCC6 mRNA expression was found in the perifocal area of irradiated cerebral cortex before 24 h postischemia. Then, the number of ERCC6 mRNA positive cells gradually enhanced, and attained a peak value at 72 h after light irradiation, which followed a declined tendency at 7-day postlesion. These results suggest that DNA repair gene ERCC6 mRNA expression in the perifocal area may be involved in the pathophysiological processes following the photochemical thrombotic cerebral ischemia. By the administration of DM, we observed that it can significantly upregulate the expression of ERCC6 mRNA in the perifocal area at 48 h after ischemic event. The neuroprotective mechanisms of DM may be related to the upregulation of DNA repair gene ERCC6 mRNA.

Neuronal ERCC6 mRNA expression in rat brain induced by a transient focal cerebral ischemia

AIM

To study whether the excision repair cross-complementing group 6 (ERCC6) is involved in the neuronal pathophysiological process following cerebral ischemia-reperfusion injury.

METHODS

A transient middle cerebral artery occlusion (MCAO) was used to induce cerebral ischemia-reperfusion injury in rat brain. Northern blot was used to check a specific signal for oligonucleotide probe. The expression of ERCC6 mRNA in the rat brain was observed by in situ hybridization. The specific cellular distribution of ERCC6 mRNA in the neuron or glia of the rat brain was analyzed by double staining combined with confocal laser scanning microscopic analysis.

RESULT

The expression of ERCC6 mRNA in the penumbra area increased following ischemia and reperfusion with a time-dependent manner. ERCC6 was expressed on d 2, reached peak values on d 3, and kept high level even on d 14 of reperfusion following ischemia. Number of ERCC6 mRNA expressive cell in the penumbra area on d 1, d 2, d 3, d 7, d 14 of reperfusion following ischemia were (0 +/- 0), (253 +/- 56), (816 +/- 355), (341 +/- 185), (128 +/- 95) x 10(6) cells/m2, respectively. Confocal microscopic analysis showed that ERCC6 mRNA coexpressed with phosphopyruvate hydratase in the neurons and with glial fibrillary acidic protein (GFAP) in a few proliferation astrocyte glia.

CONCLUSION

The expression of transcription-repair coupling factor ERCC6 mRNA in the neuron and glia was induced by ischemia-reperfusion injury.

Neuroprotective action of dextromethorphan in rat photochemically-induced focal cerebral ischemia

AIM

To study the effects of dextromethorphan (Dex) on photochemically-induced focal cerebral ischemia in rats.

METHODS

Anesthetized rats undergone 10-min light irradiation on exposed skull after rose bengal injection were pretreated with saline and Dex at 3 doses (12.5, 25, and 50 mg.kg-1, i.p., 15 min before ischemia). The alteration of volume of lesioned cortical region, regional cerebral blood flow (CBF), bcl-2 and bax expression at penumbra area were studied.

RESULTS

Dex dose-dependently decreased the infarcted volume (17%, 26%, and 50% reduction, respectively). Pretreatment with Dex at a dose of 50 mg.kg-1 improved the postischemic hypoperfusion compared with the control at 20 and 30 min after lesion (both 31% increase), and also upregulated the expression of anti-apoptosis gene bcl-2.

CONCLUSION

Dex protects against ischemic neuronal damage in this model and its effects on CBF and bcl-2 expression may contribute to its neuroprotective action.

Altered expression of glutamate transporter GLAST mRNA in rat brain after photochemically induced focal ischemia

BACKGROUND

The neurotransmitter glutamate is involved in fast excitatory synaptic transmission in the mammalian brain. Glutamate released from presynaptic terminals must be removed rapidly from the synaptic cleft by high affinity, sodium-dependent glutamate transporters to keep the extracellular glutamate concentration low to protect neuron from glutamate excitotoxicity, which is the major pathological mechanism of brain ischemia. GLAST is one of the identified four subtypes of the glutamate transporter system and has been suggested to play an important role in some pathological conditions. But until recently, very little information existed the concerning relationship between GLAST expression and cerebral ischemia.

METHODS

Nonradioactive in situ hybridization was employed to evaluate the changes of glutamate transporter GLAST mRNA expression in rat cerebral cortex and hippocampus following photochemically induced focal cortical ischemia.

RESULTS

GLAST mRNA expression in cerebral pyramid cells below the infarcted area did not change at 3 h, significantly decreased at 12 h, recovered to the control level at 24 h, and significantly increased at 72 h following the ischemic lesion. No changes in GLAST mRNA expression were observed in all subfields of the hippocampal complex.

CONCLUSIONS

The present findings suggest that the time-course changes of GLAST mRNA expression after ischemia may be correlated with the pathogenesis of photosensitive ischemic brain damage.

Effect of glutamate transporter on neuronal damage induced by photochemical thrombotic brain ischemia

To study the effects of glutamate transporters on the pathogenesis of brain infarct, pharmacological and histological analyses were carried out on the thrombotic focal ischemic model. Expression of mRNA coding for the glutamate transporter GLAST increased significantly in the penumbra at 72 h following the ischemia. Combined with confocal laser scanning microscopic analysis, double staining showed expression of GLAST mRNA in both neurons and glial cells in the penumbra. L-trans-Pyrrolidine-2,4-dicarboxylate (L-trans-PDC), a glutamate uptake inhibitor, dose-dependently enhanced the volume of the infarct induced by the ischemia. The results suggest that a compensatory increase in the activity of glutamate transporter may accompany pathological changes after ischemic injury.

Melatonin decreases production of hydroxyl radical during cerebral ischemia-reperfusion

AIM

To study the effect of melatonin on hydroxyl radical (.OH) contents during cerebral ischemia-reperfusion in rats.

METHODS

Ischemia was induced by occluding left lateral middle cerebral artery for 30 min following reperfusion. The salicylate trapping method coupled with ipsilateral striatal microdialysis for measurement of hydroxyl radicals generated during ischemia and reperfusion.

RESULTS

The contents of dihydroxybenzoic acid (DHBA) were increased at 15 min after ischemia and remained high for 30 min after reperfusion. Melatonin (4 mg.kg-1, sc, 30 min before ischemia) decreased the production of DHBA during ischemia for 16-30 min and reperfusion for 1-30 min.

CONCLUSION

Melatonin inhibits the production of hydroxyl radicals in rat brain during ischemia and reperfusion.

Pretreatment with antisense oligodeoxynucleotides directed against the NMDA-R1 receptor enhances survival and behavioral recovery following traumatic brain injury in rats

Treatment with N-methyl-D-aspartate (NMDA) receptor antagonists limits tissue damage following CNS ischemia or trauma, supporting the hypothesis that NMDA receptors participate in the pathophysiology of such injuries. An alternative approach for evaluating this hypothesis is to examine the effects of selective inhibition of NMDA receptor synthesis, using antisense oligodeoxynucleotides. In the present studies, the effects of antisense oligodeoxynucleotides directed at NMDA-R1 receptor subunit, administered intracerebroventricularly (i.c.v.) prior to injury, were evaluated in a well-defined traumatic brain injury model in rats. Outcome measures included survival, motor recovery, and histological changes. Administration of antisense oligodeoxynucleotides (15 nmol/ml twice daily x 2 days) did not alter physiological variables or motor function prior to trauma. However, such treatment significantly decreased mortality and improved behavioral recovery at 2 weeks after trauma as compared to animals treated with the corresponding sense oligodeoxynucleotides. Although cell counts in hippocampus did not differ between treatment groups, astrocyte activation as reflected by glial fibrillary astrocytic protein (GFAP) immunocytochemistry was significantly reduced in antisense treated animals. These findings provide additional evidence that NMDA receptors contribute to secondary injury after brain trauma and may suggest an alternative treatment approach.

Neuroprotective effects of 619C89, a use-dependent sodium channel blocker, in rat traumatic brain injury

Release of the excitatory amino acid (EAA) neurotransmitter glutamate has been implicated in secondary tissue damage following central nervous system (CNS) trauma and ischemia. The present study evaluated the neuroprotective actions of 619C89, a sodium channel blocker that inhibits ischemia-induced glutamate release, on traumatic brain injury (TBI) in rats using a lateral fluid percussion model. Various motor-related behavioral outcomes were used to evaluate neurologic function. Glial fibrillary acidic protein (GFAP) immunostaining and Cresyl violet staining were used to assess the histological changes. Treatment with 619C89, at a dose of 30 mg/kg administered intravenously 15 min before brain injury, significantly attenuated behavioral deficits at 24 h and 1 week. At 2 weeks, neuronal loss in the CA1 and CA3 pyramidal cell layers of the hippocampus was significantly decreased by 619C89 administration. Treatment with this compound also significantly attenuated increases in GFAP-immunoreactivity in both ipsilateral and contralateral CA1 regions. The present results suggest a potential therapeutic role for sodium channel blockade and/or glutamate release inhibition in the treatment of TBI.

High- and low-affinity NMDA receptor-binding sites in rat spinal cord: effects of traumatic injury

N-methyl-D-aspartate (NMDA) receptor-mediated events have been implicated in the pathophysiology of posttraumatic spinal cord injury. In the present study, [3H]MK801 was used to analyse the changes in NMDA receptor-binding sites in rat spinal cord after impact trauma at T9. In contrast to brain, which showed only a single binding site, spinal cord showed both high-affinity (Kd1 = 0.47 +/- 0.24 nM) and low-affinity (Kd2 = 7.75 +/- 1.82 nM) binding sites with relatively low binding density (Bmax1 = 0.11 +/- 0.04 pmol/mg protein and Bmax2 = 0.84 +/- 0.11 pmol/mg protein). Time-course studies demonstrated significant decreases in the binding of [3H]MK801 at the thoracic and lumbar segments at 4 h after spinal cord injury with recovery by 24 h. Scatchard analyses indicate that these changes likely involve both high- and low-affinity binding sites. The transitory reduction in [3H]MK801-binding after trauma may reflect downregulation of NMDA receptors as a consequence of posttraumatic glutamate release and may serve to limit excitotoxin-induced injury.

Nerve fibers containing dynorphin A in cerebral arteries

Nerve fibers containing dynorphin (Dyn) A(1-17)-like immunoreactivity were identified around cerebral arteries of guinea pig. The immunoreactive nerve fibers were richly distributed in anterior and middle cerebral arteries, but sparsely in posterior cerebral and basilar arteries. Histofluorescent study showed that large and small cerebral arteries were abundantly innervated by monoamine nerve fibers. Pretreatment with 6-hydroxydopamine or reserpine reduced the concentration of Dyn A in the wall of arteries by about 60% and 30%, respectively. These results demonstrated that there exist Dyn A immunoreactive nerve fibers in cerebral arteries and Dyn A may coexist with monoamine in perivascular nerve fibers.

N-methyl-D-aspartate receptors mediate post-traumatic increases of protein kinase C in rat brain

Male Sprague-Dawley rats were subjected to traumatic brain injury (TBI) using a lateral fluid percussion-induced injury model. Effects of varying severities of TBI (mild = 1.1 +/- 0.1 atm; moderate = 2.2 +/- 0.2 atm; severe = 2.9 +/- 0.1 atm) on the levels of protein kinase C in rat cerebral cortex and hippocampus were investigated by quantitative autoradiography using [3H]phorboldibutyrate ester ([3H]PDBu) binding as a marker. Binding of [3H]PDBu in the cerebral cortex and hippocampus was increased bilaterally following TBI, with changes related to injury severity. Significant increases were observed in hippocampus of injured animals, as compared to sham-operated controls, at 1 h after trauma. Maximum levels of binding in both cerebral cortex and hippocampus were reached by 3 h, with a return to control levels at 6 h and 72 h, respectively. Treatment with MK-801 (1 mg/kg, i.v.) administered 15 min before trauma prevented the injury-induced increase of [3H]PDBu binding in hippocampus and cerebral cortex. These results demonstrate that TBI induces bilateral, time-dependent increases of protein kinase C in the hippocampus and cerebral cortex that are related to injury severity. Changes are mediated by actions at NMDA receptors, probably reflecting post-traumatic release of glutamate.

[Modern methods of examination in the diagnosis of orbital neurilemmoma]

The important symptoms in 58 cases of neurilemmoma were slow exophthalmos and visual impairment. The diagnosis was discussed and the values of B-scan, CT and MRI were analysed.

Effects of sigma and phencyclidine receptor ligands on electric field-stimulated rabbit ear artery constriction in vitro

Several ligands of phencyclidine (Phe) receptors: Phe, dizocilpine maleate (Diz, MK-801), 1-[1-(2-thionyl)cyclohexyl] piperidine (TCP), and ligands of sigma (sigma) receptors: dl-N-allylnormetazocine (dl-SK&F-10047), 1, 3-di-ortho-tylyl-guanidine (DTG), dl-pentazocine, were tested on rabbit ear arteries in vitro. It was found that the ligands of Phe receptors enhanced the electric field stimulated vasoconstriction (ESV). Their concentration-effect curves of these compounds were parallel in the order of potencies: Phe > Diz > TCP. The ligands of sigma receptors had no effect on ESV of the arteries, but 5 mumol.L-1 reduced or increased the effect of Phe (5 mumol.L-1) on ESV. d-SK&F-10047, d-pentazocine, and DTG inhibited the effect of Phe on ESV from 364 +/- 22 mg to 142 +/- 49 mg (n = 5, P < 0.01), 262 +/- 95 mg (n = 5, P < 0.05), and 291 +/- 80 mg (n = 5, P > 0.05), respectively. The levoisomers: l-SK&F-10047 and l-pentazocine enhanced the effect of Phe on ESV from 364 +/- 22 mg to 484 +/- 78 mg (n = 5, P < 0.05), and 466 +/- 95 mg (n = 5, P < 0.05), respectively. These results revealed that there were mainly Phe receptors but hardly any sigma receptors in the arteries.

Effects of kappa, sigma, and phencyclidine receptors agonists in rat tail arteries of spontaneously hypertensive rats

The effects of the kappa receptor agonist trans-4-dichloro-N-methyl-N-(2-(1-pyrrolidin)cyclohexyl)-benzen eacefamide methane sulfonate (U-50 488H), etorphine, the sigma (sigma) receptor agonists (+)-3-(3-hydroxychenyl)-N-(1-propyl) piperidine ((+)-3-PPP), 1, 3-di-o-tolyl-guanidine (DTG), and the phencyclidine (Phe) receptor agonists Phe, N-(1-(2-thienyl)cyclohexyl) piperidine (TCP), and dizocilipine maleate (MK-801) on electrically stimulated constriction (ESC) were investigated in the rat tail arteries (RTA) of spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats. Etorphine and U-50 488H inhibited the response to ESC in SHR more than that in WKY. The effects of U-50 488H were greater than those of etorphine. The IC50 and Kact of U-50 488H in SHR were 2.5 +/- 2.0 and 0.43 +/- 0.22 mumol.L-1, respectively, while the corresponding figures in WKY were 23 +/- 15 and 2.3 +/- 1.0 mumol.L-1, respectively (P < 0.05). The inhibitory effects of (+)-3-PPP on ESC in RTA of SHR were weaker than those in WKY. Its IC50 and Kact in SHR were 11.6 +/- 5.4 and 0.87 +/- 0.30 mumol.L-1, respectively, while the corresponding figures in WKY were 0.63 +/- 0.16 and 0.35 +/- 0.18 mumol.L-1, respectively (P < 0.05). But the inhibitory effect of DTG was very slight and the difference of Kact between WKY and SHR was not significant. The enhancing effects of Phe, TCP, and MK-801 in SHR were not at all different from those in WKY at each concentration tested.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal steroids mediate the increase of hippocampal nerve growth factor biosynthesis following bicuculline convulsions

Northern blot analysis of nerve growth factor (NGF) messenger ribonucleic acid (mRNA), together with a two-site enzyme immunoassay for NGF protein, showed that a convulsive dose of bicuculline (0.4 mg/kg, IV) induced a rapid (within 1 hour) three-fold increase in hippocampal NGF mRNA. This increase was followed by a significant increase in NGF protein 5 hours later. No changes were detected in the cerebral cortex. The increase of rat hippocampal NGF mRNA and protein content was associated with an increase in plasma corticosterone content. Both responses were completely prevented by a pretreatment with diazepam (5 mg/kg, IP), which suggested that adrenal steroids might be a stimulus underlying the rapid increase in NGF biosynthesis following bicuculline convulsions. Therefore, we tested to determine whether a convulsive dose of bicuculline could increase NGF mRNA in adrenalectomized and sham-operated rats. Bicuculline increases hippocampal NGF mRNA in sham-operated rats, but not in adrenalectomized rats despite the presence of convulsions in both experimental groups. Moreover, in adrenalectomized rats, dexamethasone (0.5 mg/kg, SC) could partly restore the increase in hippocampal NGF mRNA content induced by bicuculline convulsions; thus, adrenal steroids might have an essential role in the induction of hippocampal NGF biosynthesis elicited by bicuculline convulsions.

Neuroprotective effects of phencyclidine on acute cerebral ischemia and reperfusion injury of rabbits

Acute cerebral ischemia and reperfusion injury of rabbits was produced by permanently occluding the vertebral arteries and temporarily clamping the common carotid arteries for 30 min. Phencyclidine [1-(phenylcyclohexyl)piperidine, PCP] 40-80 micrograms.kg-1 icv 30 min before ischemia significantly attenuated the decrease of the total power of electroencephalogram (EEG) within 30 min of ischemia and improved the recovery of brain electric activity following reperfusion. PCP 20-80 micrograms.kg-1 dose-dependently suppressed the creatine kinase (CK) release during cerebral ischemia and reperfusion, and PCP 40-80 micrograms.kg-1 reduced brain ischemic damage. These improvements indicated that PCP has protective effects on acute cerebral ischemia and reperfusion injury.

[Effects of phencyclidine on rabbit basilar artery in vitro and rabbit cerebral blood flow in vivo]

The effect of phencyclidine [1-(1-phenylcyclohexyl)piperidine, PCP] on rabbit basilar arteries was studied with an in vitro model of ring segment arteries. PCP 0.05-500 mumol.L-1 caused vasoconstriction of basilar arteries in a concentration-dependent manner. Its maximal effect (Emax) was 94 +/- 21 mg and the concentration causing half maximal effect (EC50) was 25 +/- 18 mumol.L-1. PCP 0.01-10 mumol.L-1 also concentration-dependently augmented the vasoconstriction induced by electric stimulation in rabbit basilar arteries. Its Emax was 91 +/- 18 mg and EC50 was 0.27 +/- 0.17 mumol.L-1. The effects of PCP on mean arterial blood pressure (MABP) and heart rate (HR) of rabbits were observed. PCP iv 4 mg.kg-1 reduced MABP from 14.3 +/- 0.8 to 12.2 +/- 1.0 kPa and HR from 300 +/- 0 to 278 +/- 5 bpm in 5 min. Using the technique of radionuclide imaging in rabbit brain in vivo, we studied the effect of PCP on cerebral blood flow. After iv PCP 4 mg.kg-1, the tp of radiocerebrogram was increased from 4.5 +/- 1.1 to 6.1 +/- 1.0 s, the tg of radiocerebrogram was increased from 11.7 +/- 0.6 to 18.2 +/- 3.3 s and the rate of clearance was decreased. After iv PCP 2 mg.kg-1, only tg increased from 12.6 +/- 2.1 to 15.9 +/- 0.6 s. Hence PCP increased the transit time of nondiffusible indicators (99mTc) through the cerebral circulation. These results suggest that PCP causes constriction of basilar artery and slows down the cerebral blood flow.

[Antagonistic effect of phencyclidine on cerebral ischemic damage of rats]

Dynorphin and catecholamine were measured in ischemic rat produced by four-vessel (2 vertebral arteries and 2 common carotid arteries) occlusion for 10 min. The results showed that: (1) The contents of dynorphine (pg/mg tissue) in cerebral cortex were 5.5 +/- 0.6 (n = 7) in normal rats and decreased to 4.9 +/- 0.5 (n = 9, P less than 0.05) in cerebral ischemic rats; with immediate ip phencyclidine (1-(1-phenylcyclophexyl)piperidine, PCP, 1 mg.kg-1), the contents of dynorphin were increased to 5.3 +/- 0.4 (n = 5, P less than 0.05 vs the ischemic rats). (2) The contents of DOPAC (pg/mg tissue) in cerebral cortex were 38 +/- 6 (n = 7) and increased to 120 +/- 60 (n = 5, P less than 0.05) in 10 min cerebral ischemic rats; with immediately ip PCP (1 mg.kg-1), the contents of DOPAC were decreased to 26 +/- 13 (n = 7, P less than 0.05 vs the ischemic rats). (3) The release of DA (pg/mg tissue) in cortical slices in vitro, in high K+ solution were 24 +/- 3 (n = 5) and significantly increased to 57 +/- 15 (n = 5, P less than 0.05) in ischemic rat brain slices; with immediate ip PCP (1 mg.kg-1), the contents of DA were decreased to 38 +/- 10 (n = 5, P less than 0.05 vs the ischemic rats). These results suggest PCP play an antagonistic role in cerebral ischemic damage of rats.

[Antagonistic effects of dextromethorphan on vasoconstriction of phencyclidine in vitro]

Bioassay and spectrophotofluorometry were used to study the antagonistic effect of dextromethorphan (DM) on phencyclidine (PCP) vasoconstriction in rabbit ear artery. DM (5 mumols.L-1) antagonized enhancement of PCP, N-[1-(2-thienyl) cyclohexyl] piperidine (TCP) and dizocilpine maleate (MK-801) (5 mumols.L-1) on electrical stimulation-induced vasoconstriction by 86 +/- 18%, 84 +/- 17%, and 86 +/- 18%, respectively (n = 6, P less than 0.01), but had no obvious bioactivity itself at the same concentration. DM (1, 2.5, and 5 mumols.L-1) inhibited the PCP effect and reduced the maximal effect of PCP with pD2' = 5.3 +/- 0.3 (n = 4). The contents of norepinephrine (NE) in control, PCP, and DM + PCP groups were 5 +/- 6, 12 +/- 8, and 5 +/- 6 ng.ml-1, respectively (n = 9). PCP (10 mumols.L-1) increased the NE release (P less than 0.05) but DM (10 mumols.L-1) inhibited it (P less than 0.01). The results suggest DM may be a noncompetitive blockader for PCP receptors.

[Ultrasonic pachymetry of the cornea]

The DGH-2000 Ultrasonic Pachymeter was used in the measurement of the corneal thickness in 100 patients (200 eyes). The central and peripheral corneal thickness averaged 543.5 +/- 24.7 microns and 743.7 +/- 33.6 microns respectively. There was no significant difference between sexes or between the right and left eyes.

[Effects of phencyclidine analogs and phencyclidine/sigma ligands on vasoconstrictor response of rat mesenteric arteries induced by electrical field stimulation]

Using the model of perfused mesenteric arteries of rat, we studied the effect of phencyclidine (PCP), N-[1-(2-thienyl)cyclohexyl] piperidine (TCP), N,N-dimethylphenylcyclohexylamine (PCDA), N-(iso-propyl)-1-phenylcyclohexylamine (PCIPA), (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine maleate (MK-801), (+),(-)-N-allylnormetazocine (SKF 10 047), dextrorphan, and levorphanol on vasoconstrictor response induced by electrical field stimulation. PCP, TCP, PCDA, PCIPA, MK-801, levorphanol, and (-)-SKF 10 047 were found to increase the vasoconstrictor response in dose-dependent manner. The dose-effect curves of these compounds were similar to the curve of PCP. Although dextrorphan, an antagonist for PCP receptors, did not affect the vasoconstrictor response, it could non-competitively antagonize PCP's action. These studies suggest that some PCP analogs and PCP/sigma ligands may enhance the vasoconstrictor response induced by electrical field stimulation via action on PCP receptors.

[Phencyclidine receptors in porcine cerebral arteries]

A specific, saturable, reversible, and selective binding site with Kd = 87 +/- 33 nmol/L, Bmax = 0.78 +/- 0.11 pmol/mg protein was detected in the binding of [3H] phencyclidine (PCP) to porcine cerebral blood vessels. Only ligands of PCP/sigma series were able to bind to the PCP receptors. [3H]PCP bound to its receptors was not displaced by etorphine or norepinephrine 0.1 mmol/L. A specific [3H]PCP binding site was found in porcine brain with Kd = 75 +/- 34 nmol/L, Bmax = 0.61 +/- 0.23 pmol/mg protein. Bioassay in vitro showed PCP enhanced the perfusion pressure of porcine cerebral blood vessels in a dose-dependent manner. This study provides direct evidence for PCP receptors on cerebral blood vessels, and suggests that PCP may produce cerebral vasospasm via PCP receptor interaction.

[Mechanism of dynorphin inhibition on vasoconstriction in vitro]

Bioassay and HPLC detection were used to analyze the mechanism of inhibition of stimulation-induced vasoconstriction by dynorphin 1-13 (D1-13). Bioassay showed that D1-13 inhibited the contraction of rabbit ear artery and mesenteric artery induced by electrical field stimulation with IC50s of 8.5 +/- 1.2 x 10(-8) mol/L (n = 4) and 5.02 +/- 1.3 x 10(-7) mol/L (n = 5), respectively. D1-13 was ineffective in rabbit femoral artery at a concentration even larger than 10(-6) mol/L. D1-13 did not alter the basal tension of the blood vessel, nor the vasoconstriction induced by adding norepinephrine (NE) into the bath medium, and both constriction were markedly inhibited by phentolamine, an alpha-adrenoceptor blocker. With HPLC detection, the contents of NE in the bath medium were significantly reduced by D1-13 (5 x 10(-7) mol/L) from 340.56 +/- 73.13 pg/ml to 76.91 +/- 10.26 pg/ml as compared with control group (P less than 0.05). The effect could be completely reversed by naloxone at a concentration of 10(-6) mol/L (P less than 0.05). The results suggest that D1-13 reduces stimulation-induced vasoconstriction probably through a presynaptic inhibition of NE release from the nerve terminals.

[Autoradiographic study on etorphine and phencyclidine specific binding sites in rabbit mesenteric artery]

Autoradiography was used to study the localization of kappa and PCP/sigma receptors in the blood vessels. Slices of rabbit mesenteric arteries were incubated with 0.4 nmol/L [3H]etorphine or/and 10 mumol/L etorphine for 45 min at 25 degrees C, or incubated with 5.2 nmol/L [3H]PCP or/and 20 mumol/L PCP for 60 min at 4 degrees C. Then, slices were covered with emulsion coated coverslip and kept for 8-10 wk at 4 degrees C. The results were as follows: Microscopy Autoradiographic analysis indicated that etorphine and PCP specific binding sites were both located in the outer-layer and the smooth muscle of the artery. However, most of these binding sites were lost in the 6-OHDA pretreated arteries in which the adrenergic nerve endings were destroyed. Microspectrophotometry The absorbance (A) of [3H]etorphine autoradiographic density for total binding (TB) and nonspecific binding (NSB) in control group were 0.416 +/- 0.056 and 0.044 +/- 0.011, respectively (P less than 0.01), and for TB after incubation with 6-OHDA was 0.068 +/- 0.013 which was different from the A value of TB in the control (P less than 0.01). The A value of [3H]PCP autoradiographic density for TB and NSB in the control were 0.546 +/- 0.087 and 0.023 +/- 0.060, respectively (P less than 0.01), and for TB after incubation with 6-OHDA was 0.065 +/- 0.015 which was significantly less than that of TB in the control group (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)