Pretreatment Non-Invasive Biomarkers as Predictors to Estimate Portal Vein Tumor Thrombosis (PVTT) Risk and Long-Term Survival in HBV-Related Hepatocellular Carcinoma Patients Without PVTT

Background

PVTT is a hallmark of advanced hepatocellular carcinoma (HCC). We aim to explore the influence of non-invasive biomarkers on the occurrence of PVTT and develop and validate models for predicting prognosis in HBV-related HCC patients without PVTT.

Methods

A total of 1026 HBV-related HCC patients without PVTT were enrolled, with 515 in the training cohort, 216 in the internal validation cohort, and 295 in the external validation cohort. We conducted Cox regression analyses to discern the independent risk factors associated with PVTT events, PFS, and OS, then constructed and validated predictive models. The predictive and discriminatory capabilities of models were assessed using the calibration, time-dependent ROC, and DCA curves.

Results

In our study, 136 patients (13.3%) experienced PVTT events during the follow-up period. The Cox regression analysis unveiled that male gender, AAPR ≤0.49, APRI >0.48, extrahepatic metastasis, and multiple tumors were independent risk factors for PVTT. In the training cohort, non-invasive biomarkers (AAR and APRI), AFP, ascites, and tumor-related characteristics (extrahepatic metastasis, tumor diameter, tumor number, and PVTT event) were independent risk factors for both OS and PFS, whereas age and ALBI grade independently correlated with OS. The C-indexes of OS and PFS nomogram models were 0.795 and 0.733 in the training cohort, 0.765 and 0.716 in the internal validation cohort, and 0.780 and 0.722 in the external validation cohort, respectively. Our models demonstrated strong predictive and discriminative abilities in all cohorts and yielded a greater net benefit compared to three traditional staging systems.

Conclusion

Non-invasive biomarkers are expected to be reliable predictors for assessing PVTT risk and predicting prognosis among HBV-related HCC patients without PVTT.

Fas/FasL and Complement Activation are Associated with Chronic Active Epstein-Barr Virus Hepatitis

BACKGROUND AND AIMS

Chronic active Epstein-Barr virus hepatitis (CAEBVH) is a rare and highly lethal disease characterized by hepatitis and hepatomegaly. This study aimed to investigate the clinicopathological features and pathogenic mechanisms of CAEBVH.

METHODS

Ten patients with confirmed Epstein-Barr virus hepatitis infection were enrolled. The clinicopathological characteristics of these patients were summarized and analyzed. Flow cytometry was utilized to detect peripheral blood immune cell phenotypes and whole exome sequencing was used to explore pathogenic genetic mechanisms. Lastly, immunohistochemical staining was employed to verify pathogenic mechanisms.

RESULTS

Clinical features observed in all Epstein-Barr virus hepatitis patients included fever (7/10), splenomegaly (10/10), hepatomegaly (9/10), abnormal liver function (8/10), and CD8⁺ T cell lymphopenia (6/7). Hematoxylin and eosin staining revealed lymphocytic infiltration in the liver. Positive Epstein-Barr virus-encoded small RNA in-situ hybridization (EBER-ISH) of lymphocytes of liver tissues was noted. Whole exome sequencing indicated that cytotoxic T lymphocytes and the complement system were involved. The expression of CD8, Fas, FasL, and Caspase-8 expression as well as apoptotic markers was enhanced in the Epstein-Barr virus hepatitis group relative to the controls (p<0.05). Lastly, Complement 1q and complement 3d expression, were higher in CAEBVH patients relative to controls (p<0.05).

CONCLUSIONS

CAEBVH patients developed fever, hepatosplenomegaly, and lymphadenopathy. Histopathological changes were a diffuse lymphocytic sinusoidal infiltrate with EBER-ISH positivity. Fas/FasL and complement activation were involved in CAEBVH patients.

[Application and prospect of digital technology on personalized precision nutrition]

Nowadays in China, digital technology is sweeping all walks of life. To deal with the increasing incidence of chronic diseases and people's pursuit of a healthy life expectancy, modern nutrition, which is a core element in the prevention and treatment of chronic diseases, has gradually entered the digital age and raised broader needs and higher standards for achieving individualized precision nutrition. Artificial intelligence and augmented reality technologies have been used to improve the accuracy of dietary surveys. The digital dietary quality monitoring and evaluation system established by integrating multiple nutritional and health databases are conducive to scientifically and effectively assessing the overall dietary quality. Wearable devices and chemical sensors have made nutrition assessment more efficient. Digital and precise nutrition developed for different populations and different diseases are realized. Nutrition education has been carried out rapidly with the popularization of "Internet+", new media, and application software. The various digital intelligent technologies have gradually penetrated into the dietetics field and empowered personalized health management. In addition, the technologies of digital nutrition in China still face a lot of challenges from theory to practice. How to promote scientific and technological innovation in digital nutrition to stimulate and enhance people's nutritional health is the major task ahead of nutrition science nowadays. This article will briefly introduce digital nutrition survey and assessment, digital nutrition intervention, and intelligent nutrition education, in order to provide a reference for realizing national nutrition and health by digital means.

Specific PCR-based detection of Phomopsis heveicola the cause of leaf blight of Coffee (Coffea arabica L.) in China

Coffee (Coffea arabica L.) is currently grown in many tropical and subtropical areas countries and is a major traded commodity for the developing world. Coffee leaf blight, caused by Phomopsis heveicola, is one of the most important fungal diseases dangerous to coffee crops in China. This study aimed to develop a PCR-based diagnostic method for detecting P. heveicola in planta. Specific primers (CPHF/CPHR) were designed based on sequence data of region of internal transcribed spacer (ITS1 and ITS4) of P. heveicola. The efficiency and specificity of CPHF/CPHR were established by PCR analysis of DNA from P. heveicola strains isolated from China and fungal isolates of other genera. A single amplification product of 318 bp was detected from DNA P. heveicola isolates. No amplification product was observed with any of the other fungal isolates tested. The specific primers designed and employed in PCR detected P. heveicola up to 3 pg from DNA isolated. This is the first report on the development of a species-specific PCR assay for identification and detection of P. heveicola. Thus, the PCR-based assay developed was very specific, rapid and sensitive tool for the detection of pathogen P. heveicola.

Time Regularity of Morphology of Blood Pools

Abstract

Objective To provide reference indexes and theoretical basis for age estimation of blood pools by investigating the entire drying process and monitoring the change of morphology and mass. Methods Four 15 mL blood pool samples were prepared on the clean ceramic plate. The change of morphology and mass of blood pools in a closed dark environment with a temperature of （20.0±0.5） ℃ and a humidity of 35%-45% were dynamically observed from 0 h to 60 h. Images of the blood pools were recorded by digital camera. The area of blood pools was calculated by MATLAB R2014b, the length of cracks was measured by Image J and the statistical analysis was performed by SPSS 16.0. Results By summarizing and analyzing, the drying of blood pools was divided into five stages： coagulation （0-4.5 h）, gelation （>4.5-20.0 h）, gel-solid mixing （>20.0-37.0 h）, solid （>37.0-40.0 h） and final desiccation （>40.0-45.0 h）. From 0 to 45 h, the mass of the blood pools decreased linearly with time, and the decrease was not obvious from 45.0 to 60.0 h. The standardized mass （y₂） showed strong correlation with the time （x） y₂=0.018 2 x+0.271 4（R²=0.967 9）. The area change rate of blood pools, the distance that the edge of blood pools moved, the average length of radical cracks had little correlation with the time that passed. Conclusion The overall morphological characteristics of blood pools show a certain regularity with the time and the standardized indexes established provide a reference for the age estimation of blood pools.

[Role of microRNA and lncRNA in lens development and cataract formation]

Both microRNA (miRNA) and long noncoding RNA (lncRNA) fall within the category of noncoding RNA. MiRNA is a 20-24 nt long, highly conserved, single-stranded noncoding RNA. MiRNA can specifically bind to the 3' untranslated region of target mRNA, induce the transcript degradation or translation inhibition, and eventually impact the biological functions of the cell, such as proliferation, differentiation, and apoptosis. Whereas lncRNA is an over 200 bp long, single-stranded, noncoding RNA, which can regulate the important biological processes, such as cell division, growth, differentiation and apoptosis. Research has demonstrated that the abnormal expression of miRNA or lncRNA may result in disruption of normal lens development, apoptosis of lens epithelial cells, disarrangement of lens fibrocytes and treduced lens transparency, thereby causing cataract. This review summarizes the effects and the mechanisms of 7 miRNAs (miR-184, miR-204, let-7, miR-29, miR-16, miR-125b, miR-34a) and 2 lncRNAs (lncRNA-MIAT, LOXL1-AS1) during lens development and cataract formation, in the hope that it could provide insights for the novel interventional and therapeutic targets to cataract. (Chin J Ophthalmol, 2018, 54: 390-395).

Development of Integrated Device of Trace Bloodstains Imaging and Age Analysis

Abstract

Objective To develop a device of trace bloodstains imaging and age analysis, so as to provide a non-destructive, simple and objective method for age estimation of bloodstains at the crime scene. Methods Based on the principle of digital imaging and color pattern analysis, the mobile terminal of the device was used to collect images of bloodstains of different ages. The time-dependent pattern of 6 parameters （R, G, B, C, Y, M） reflecting the changes of color of images of different ages was obtained by computer image analysis. A multiparameter comprehensive inference equation of bloodstains age was established and embedded into the device software to realize the intelligent inference of the bloodstains age. Then the capability and reliability of the device was verified. Results This integrated device of bloodstains imaging and age analysis could quickly collect bloodstains at the crime scene and automatically analyze and infer the age of bloodstains combined with related intelligence software. In the blind test, the detection accuracy of this device was 95% in both natural light airtight group and dark airtight group, and 80% in the natural light ventilation group. Conclusion The integrated device of trace bloodstains imaging and age analysis can be used in a simple manner, which provides a new objective method for bloodstains age estimation.

Nonanatomic resection is not inferior to anatomic resection for primary intrahepatic cholangiocarcinoma: A propensity score analysis

Whether anatomic resection (AR) achieves better outcomes than nonanatomic resection (NAR) in patients with primary intrahepatic cholangiocarcinoma (ICC) is unclear. Data were retrieved for all consecutive patients who underwent liver resection for primary ICC from January 2007 to July 2017. The prognoses of the patients without direct invasion to contiguous organs or extrahepatic metastasis who underwent AR or NAR were compared. 85 patients underwent AR, and 65 patients underwent NAR. operation time were slightly decreased in the NAR group. The risk of Clavien-Dindo classification (CDC) IV in the AR group was significant higher than that in the NAR group. Cox regression analysis showed lymph node metastasis and adjuvant therapy were significant prognostic factors for overall survival (OS) and disease-free survival (DFS), respectively. After 1:1 propensity score matching (PSM), 29 pairs of patients were compared. The survival curves showed the NAR group had slightly improved DFS and OS than the AR group before and after matching. Thus, we conclude NAR was not inferior to AR in improving the survival outcomes for patients with primary solitary ICC lesions without direct invasion to contiguous organs or extrahepatic metastasis. Furthermore, patients may benefit from NAR.

[Association of epicardial adipose tissue with cardiovascular risk factors and coronary artery calcification in the community residents]

Objective: This cross-sectional study aimed to address the relationship between the volume of epicardial adipose tissue (EAT) with cardiovascular risk factors and coronary artery calcification(CAC) in the community residents. Methods: Individuals were recruited from the Jidong Community (Tangshan City, Northern China) which mainly comprised employees of the Jidong Co. Ltd. and their family members. From July 2013 to August 2014, 2 647 participants aged ≥40 years were included in this study. The volume of EAT and coronary artery calcification score (CAC score) were determined by a 64-slice CT. Carotid intima-media thickness (CIMT) was measured by a trained sonographer using a high-resolution B-mode topographic ultrasound system. Venous blood samples were analyzed by automated analyzers in the central laboratory. A validated questionnaire specifically designed for this study was used to collect demographic data from all participants by trained doctors. Characteristics of study cohort were compared according to quartiles of EAT volume (n=660, 663, 662, 662, repectively). Results: (1) The mean age of participants was (55.31±7.76) years and 49.94% (n=1 322) were men. The median EAT volume (interquartile) was 129.42 (95.66, 176.51)cm(3). (2) Age, BMI, waist circumference and hip circumference, systolic blood pressure, LDL-C, triglycerides, and fasting blood glucose were significantly higher, while HDL-C level was significantly lower in participants with higher EAT volume than participants with lower EAT volume (all P<0.05). Carotid intima-media thicken (CIMT) and higher CAC score were also significantly higher in participants with higher volume of EAT. Furthermore, percentage of diabetes mellitus, hypertension, hyperlipidemia increased in proportion with increasing EAT volume (P<0.05). (3) In the linear regression, significant positive relations were found for age (β=0.019 3, 95%CI 0.017-0.021, P<0.001), waist circumference (β=0.012 7, 95%CI 0.009-0.016, P<0.001), BMI (β=0.022 4, 95%CI 0.013-0.032, P<0.001), LDL-C (β=0.048 4, 95%CI 0.021-0.076, P<0.001), and HDL-C (β=-0.098 1, 95%CI-0.164--0.032, P<0.001) was inversely related to the EAT volume. (4) Logistic regression analysis indicated that EAT volume was an independent risk factor for CAC score>0 (OR=1.233, 95%CI 1.205-1.262, P<0.001) . Conclusions: Our findings indicate that EAT volume is strongly correlated to cardiovascular risk factors and coronary calcification and is an independent risk factor of increased coronary calcification in community residents.

[Long-term prognostic value of lowering in free triiodothyronine in patients with hypertrophic cardiomyopathy]

Objective: To determine whether thyroid hormone (TH) level could also be an independent and incremental predictor of adverse events in patients with hypertrophic cardiomyopathy (HCM). Methods: A total of 982 consecutive patients with HCM at the National Center for Cardiovascular Diseases (China) from October 2009 to December 2013 were included in the present study, and followed up till the end of December 2016. The patients were divided into three groups according to the levels of free triiodothyronine (FT₃): the group 1 (FT₃≤4.28 pmol/L, n=335), the group 2 (FT₃>4.28-<4.79 pmol/L, n=310), and the group 3 (FT₃ 4.79-6.30 pmol/L, n=337). Results: After a follow-up period of (53.8±14.1) months, 39 patients (4.0%) either suffered death with all causes or received a cardiac transplantation (7.8%, 2.9% and 1.2% of the patients in the group 1, group 2 and group 3, respectively). A multivariable Cox regression analysis revealed that FT₃≤4.28 pmol/L was associated with a significantly higher risk of all-cause mortality or cardiac transplantation (HR 8.83, 95% CI 1.115- 69.905,P=0.039) in HCM patients. Conclusions: Low levels of FT₃ is a risk factor of adverse events for patients with HCM, indicting a role of FT₃ as a marker for assessing the risk of long-term adverse events in these patients.

[Value of N-terminal pro-B-type natriuretic peptide on long-term outcome of patients with hypertrophic cardiomyopathy]

Objective: To determine the value of N-terminal pro-B-type natriuretic peptide (NT-proBNP) on predicting the long-term outcome of patients with hypertrophic cardiomyopathy (HCM) . Methods: NT-proBNP was measured in 831 consecutive patients with HCM at Fuwai Hospital from October 2009 to December 2013 and patients were followed up clinically for (53.3±15.4) months. Patients were divided into 3 groups according to NT-proBNP values: NT-proBNP<860 pmol/L (n=276) , 860 pmol/L≤NT-proBNP≤1 905 pmol/L (n=278) , NT-proBNP>1 905 pmol/L (n=277) . The related baseline data, laboratory examination and echocardiographic results were compared among groups. The primary endpoints of this study were all-cause mortality and cardiac transplantation. Cox proportional hazards model was used to estimate hazard ratio (HR) . Kaplan-Meier analysis was used to evaluate the survival status of patients among the 3 groups. Results: During a median follow-up of (53.3±15.4) months, all-cause mortality or cardiac transplantation occurred in 37 patients (4.5%) , event rate was 1.4% (4/276) , 4.0% (11/278) and 7.9% (22/277) in patients with NT-proBNP<860 pmol/L, 860 pmol/L≤NT-proBNP≤1 905 pmol/L and NT-proBNP>1 905 pmol/L, respectively. Multivariable Cox regression analysis identified that age (HR 1.066, 95%CI 1.027-1.107) and NT-proBNP (HR 1.026, 95% CI 1.010-1.042) were independent predictors of all-cause mortality or cardiac transplantation. Among the 3 groups, the survival rate of the NT-proBNP<860 pmol/L group was the highest,and that of the NT-proBNP>1 905 pmol/L group was the lowest (P<0.01) . Conclusions: The level of NT-proBNP provides clinically relevant information for long-term adverse events risk stratification in patients with HCM.

[Research Progress on Diagnosis of Drowning]

These external and internal signs of drowning are non-specific. Therefore, diagnosis of drowning is always one of the most difficult tasks in forensic pathology. This paper meticulously and comprehensively reviews research progress on the diagnosis of drowning in pathological signs, laboratory examination, immunohistochemistry test and virtopsy technology, and it also prospects the research direction of diagnosis of drowning.

[Visual impact of sub-tenon's anesthesia during surgery for retinal detachment]

Objective: To investigate the visual impact and influence factors of sub-Tenon's anesthesia in retinal detachment patients during pars plana vitrectomy (PPV) or combined phacoemulsification and PPV surgery. Methods: In this prospective case series study, 104 consecutive patients who underwent PPV or combined phacoemulsification and PPV under sub-Tenon's anesthesia between October 2012 and December 2013 were enrolled. Intraoperatively, the patients were asked whether they could see the light of the operating microscope or not at 5 minutes after sub-Tenon's anesthesia, and at the end of phacoemulsification, core vitreous removal, peripheral vitreous removal and the whole surgery, with their contralateral eyes being covered tightly and no photobleaching. The best corrected visual acuity and visual evoked potentials were examined and compared with each other preoperatively and at 1.5 months and 3 months postoperatively. Chi-square test was used to compare the detection rate of amaurosis between different modus operandi and whether covered contra-lateral eye. Student-t test was used to compare the difference of age and preoperative BCVA between the patients with or without experienced amaurois. Lastly, BCVA between different times were tested by one-way ANOVA analysis. Results: Without covering the contralateral eyes, the incidence of no light perception in various surgical steps was 0%, while it was 72.1%(75/104), 93.8%(75/80), 96.2%(100/104), 96.2%(100/104) and 86.5%(90/104) at the five timepoints, respectively, when the contralateral eyes were covered tightly. The incidence was 51.9%(54/104), 85.0%(68/80), 85. 6%(89/104), 84.6%(69/104) and 66.3%(88/104), respectively, after photobleaching was excluded. Approximately 95.2%(99/104) of patients reported no light perception at least once, 54.5%(54/99) reported no light perception 5 minutes after sub-Tenon's anesthesia, and 30.3%(30/99) recovered light perception when the surgery was finished. All eyes recovered to at least light perception on the first postoperative day. The best corrected visual acuity and visual evoked potentials at 1.5 months and 3 months postoperatively were significantly better than those before surgery. The BCVA was 1.75±0.78 preoperative, 0.96±0.63 1.5 months after operation, and 0.92±0.57 3 months after operation. There was a significant statistical difference between preoperative BCVA and postoperative BCVA (F=50.61, P<0.01) . In patients without waveform detection preoperatively, PVEP waveform could be found in 43.6% and 61.4% of the pactients at 1.5 months and 3 months after operation respectively. In those had certain waveform preoperatively, PVEP amplitudes rise significantly after surgery (t(1.5)=-2.69, t(3)=-2.97, P<0.05) . Conclusions: No light perception was detected in various surgical steps of vitrectomy under sub-Tenon's anesthesia in most patients. The blocking of optic nerve conduction may be caused by sub-Tenon' s anesthesia. Photobleaching can also have some effect. The incidence of no light perception during the surgery was not correlated with preoperative visual acuity, age and gender. Moreover, the effect was transient and harmless to visual function.(Chin J Ophthalmol, 2017, 53: 332-337).

[Analysis on antiretroviral therapy efficacy for HIV/AIDS in Zhejiang province, 2009-2014]

OBJECTIVE

To analyze the efficacy of highly active antiretroviral therapy(HAART)for HIV/AIDS in Zhejiang province from 2009 to 2014.

METHODS

A retrospective cohort study was conducted among patients with access to HAART aged <15 years from 2009 to 2014 through descriptive epidemiological analysis on the patients' demographic characteristics, HAART efficacy. The immune recovery Kaplan-Meier curves were drawn by using baseline CD(4) T lymphocytes cell(CD(4))data. The influencing factors for virus suppression were analyzed by using logistic regression model.

RESULTS

There were 9 594 patients with access to HAART in Zhejiang from 2009 to 2014. The' average age of the patients was 38.7 years old, the male to female ratio was 4.11∶1. Heterosexual(55.9%)and homosexual(40.0%)contacts were the main transmission routes. Baseline CD(4) count 200-349 cells/μl was found in 45.4% of the patients, the median of the CD(4) count was 221(IQR: 123-298). The median of time for CD(4) recovery in patients with baseline CD(4) count <200 cells/μl was 3.48 and 11.58 times higher than the patients with baseline CD(4) count 200-349 cells/μl and baseline CD(4) count ≥350 cells/μl. Univariate and multivariate logistic regression analyses showed that marital status, HAART regimen, treatment miss in last week and CD(4) recovery were major influencing factors for HAART efficacy.

CONCLUSIONS

HAART had good treatment effecacy in HIV/AIDS patients in Zhejiang. The baseline CD(4) count and adherence to HAART were the most important influencing factors. It is recommended to take measures to expand HIV screening and HAART coverage, conduct HAART adherence education, and strengthen the special care for high-risk groups to improve the HAART efficacy in Zhejiang province.

Alleviation of spinal cord injury by Ginkgolide B via the inhibition of STAT1 expression

Ginkgolide B has been known to inhibit cell apoptosis by modulating multiple cytokines and plays an important role in neuroprotection. Signal transducer and activator of transcription 1 (STAT1) has been studied in a spinal cord injury (SCI) model. However, the role of Ginkgolide B in SCI treatment remains unclear. This study investigated the potential mechanism of Ginkgolide B using an SCI rat model. SD rats were used to generate an SCI model followed by Ginkgolide B injection (4 mg/kg) for 14 days. Spinal cord tissue samples were examined using hematoxylin and eosin (H&E) staining. The expression of STAT1 was determined by western blot. Using a dyskinesia scale, intervention with Ginkgolide B significantly decreased the severity of SCI. H&E staining revealed less nuclear condensation and cell necrosis in SCI rats after treatment with Ginkgolide B. STAT1 expression was significantly increased in SCI model rats, but was lower after Ginkgolide B treatment. Therefore, Ginkgolide B can effectively inhibit STAT1 expression and alleviate SCI.

Association Between Post-Cancer Diagnosis Dietary Inflammatory Potential and Survival in WHI Observational Study and Dietary Modification Trial

Background: Inflammation regulates key biologic processes in chronic disease and can be modulated by diet. Our objective was to use the dietary inflammatory index (DII), a novel tool to characterize the inflammatory potential of diet, to examine how post-cancer diagnosis dietary quality is associated with overall survival in the Women's Health Initiative (WHI) Observational Study (OS) and Dietary Modification Trial (DM). Methods: After excluding baseline cancers and energy outliers, the analytical cohort had 4,241 postmenopausal women (19% of total cancer cases), aged 50 to 79 years at baseline, in the WHI OS (n = 1,852) and DM (n = 2,389), who developed invasive cancer during follow-up and completed a food frequency questionnaire after diagnosis. These women were followed from dietary assessment until death from any cause. Energy-adjusted DII scores from food only and from food plus supplement (any reported dietary supplement related to DII parameters) after cancer diagnosis for each subject were calculated by multiplying the inflammatory effect scores determined based on extensive literature review and intake values for each food parameter, and then summing across all the food parameters. Death was ascertained by clinical center follow-up or by searching the National Death Index with central or local adjudication. Cox proportional hazards models were fit to estimate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CI) for all-cause mortality comparing women in higher DII quartiles with those in the first quartile. Results: After a median 11.2 years of follow-up, 1,470 deaths occurred. After adjustment for key covariates, women who consumed a more pro-inflammatory diet (in higher quartiles of DII score from food only) after a cancer diagnosis had a significantly higher risk of death from any cause compared to women consuming a more anti- inflammatory diet (HR Q4:Q1 = 1.18; 95% CI, 1.01–1.38; P trend = 0.015). In analyses using DII score from both diet and supplements, a pro-inflammatory DII score was associated with even higher risk of all-cause mortality (HRQ4:Q1 = 1.63; 95% CI, 1.40–1.91; P trend &lt; 0.0001). Conclusions: Consuming a more pro-inflammatory diet after cancer diagnosis was associated with increased risk of death from any cause.

RIG-I detects HIV-1 infection and mediates type I interferon response in human macrophages from patients with HIV-1-associated neurocognitive disorders

The aim of this study was to explore the precise role of retinoic acid-inducible gene-I (RIG-I) signaling in human immunodeficiency virus type 1 (HIV-1)-infected macrophages from patients with HIV-1-associated neurocognitive disorders (HAND). Postmortem brain tissues were collected from patients with HIV-1-associated dementia and were compared to samples collected from HIV serum-positive patients without dementia and HIV serum-negative patients. A human monocyte-derived macrophage (MDM) primary culture system was established to evaluate the expression of RIG-I in these samples. Knockdown of RIG-I pathways genes was employed and STAT1 expression and phosphorylation levels were examined to explore the molecular mechanisms of HAND. The expression of RIG-I in postmortem brain tissue from HAND patients was significantly higher than in patients who were HIV serum-positive without dementia or HIV serum-negative. Moreover, we demonstrated that HIV-1 infection could result in a significant increase in the level of RIG-I in human MDMs. Moreover, a correlation was found between the increase in RIG-I expression and STAT1 expression and phosphorylation. Accordingly, knockdown of RIG-I decreased the phosphorylation of STAT1 and downregulated interferon-related genes. These observations highlight the importance of RIG-I signaling in anti-HIV innate immunity in macrophages, which may be beneficial for the treatment of HIV and aid in the understanding of the neuropathogenesis of HAND.

Cloning and prokaryotic expression of rat homolog of Serpina3n and its expression change during liver regeneration

A strikingly upregulated expressed sequence tag was screened from regenerating rat liver at 8 h in a 0-4-8-12 h short-interval successive partial hepatectomy model from a previous study. In the present study, a full-length open reading frame (ORF) corresponding to this expressed sequence tag was predicted through electronic cloning and was subsequently cloned from an 8-h rat regenerating liver and deposited in GenBank (accession No. HM448398). Sequence analysis of HM448398 and the predicted ORF revealed that the two ORFs may be different transcripts of a gene. The sequence of HM448398 was highly homologous to that of rat Serpina3n, suggesting that it may be a homolog of Serpina3n. The pGEX-2TK prokaryotic expression vector for this ORF was constructed, and the result of sodium dodecyl sulfate polyacrylamide gel electrophoresis manifested that the recombinant expression vector could express the glutathione-S-transferase-fused rat homolog of Serpina3n in an insoluble form in BL21. The target fusion protein was purified with affinity chromatography and was used as antigen to immunize rabbits for the production of polyclonal antibodies. Immunohistochemistry and real-time reverse transcription polymerase chain reaction analysis revealed that the gene was highly expressed in the priming and termination phases of liver regeneration. These findings lay a solid foundation for further study of roles of HM448398 using knock-in and RNA interference methods during liver regeneration.

Computerized errorless learning-based memory rehabilitation for Chinese patients with brain injury: A preliminary quasi-experimental clinical design study

AIM

To evaluate the effectiveness of a computerized, errorless learning-based memory rehabilitation program for Chinese patients with traumatic brain injury (TBI).

METHODS

This study adopted a pre- and post-test quasi-experimental design. A total of 37 patients with TBI were randomly assigned to a Computer-Assisted Memory Training Group (CAMG), a Therapist-administered Memory Training Group (TAMG) and a Control Group (CG). Except for the CG, the patients in both the CAMG and TAMG groups received, respectively, 1-month memory training programmes that were similar in content but differed in delivery mode. All patients were followed up 1 month after treatment. The outcome measures that were taken were the Neurobehavioural Cognitive Status Examination (NCSE or Cognistat), the Rivermead Behavioural Memory Test (RBMT) and The Hong Kong List Learning Test (HKLLT). Repeated measure analyses were performed to investigate differences among the three groups.

RESULTS

The patients in the Computer-assisted Memory Rehabilitation (CAMG) and Therapist-administered Memory Rehabilitation group (TAMG) were found to perform better than the CG in the NCSE and RBMT, but no significant differences were found between the CAMG and TAMG. The CAMG showed significant improvement in their HKLLT assessment as compared with the TAMG and CG. No statistically significant differences were found between the CAMG and TAMG when comparing the post-training outcome measures with the follow-up results.

CONCLUSION

There is no difference between CAMG and TAMG, but the efficacy has been demonstrated when comparing with CG. It is suggested that the combined use of an errorless learning and a computerized approach may be an effective way of enhancing the memories of patients with TBI. This new method may smooth the progress of the whole human memory process and produce a better carryover treatment effect.

Hes1 is a negative regulator of inner ear hair cell differentiation

Hair cell fate determination in the inner ear has been shown to be controlled by specific genes. Recent loss-of-function and gain-of-function experiments have demonstrated that Math1, a mouse homolog of the Drosophila gene atonal, is essential for the production of hair cells. To identify genes that may interact with Math1 and inhibit hair cell differentiation, we have focused on Hes1, a mammalian hairy and enhancer of split homolog, which is a negative regulator of neurogenesis. We report here that targeted deletion of Hes1 leads to formation of supernumerary hair cells in the cochlea and utricle of the inner ear. RT-PCR analysis shows that Hes1 is expressed in inner ear during hair cell differentiation and its expression is maintained in adulthood. In situ hybridization with late embryonic inner ear tissue reveals that Hes1 is expressed in supporting cells, but not hair cells, of the vestibular sensory epithelium. In the cochlea, Hes1 is selectively expressed in the greater epithelial ridge and lesser epithelial ridge regions which are adjacent to inner and outer hair cells. Co-transfection experiments in postnatal rat explant cultures show that overexpression of Hes1 prevents hair cell differentiation induced by Math1. Therefore Hes1 can negatively regulate hair cell differentiation by antagonizing Math1. These results suggest that a balance between Math1 and negative regulators such as Hes1 is crucial for the production of an appropriate number of inner ear hair cells.

Overexpression of Math1 induces robust production of extra hair cells in postnatal rat inner ears

For mammalian cochlear hair cells, fate determination is normally completed by birth. We report here that overexpression of Math1, a mouse homolog of the Drosophila gene atonal, in postnatal rat cochlear explant cultures resulted in extra hair cells. Surprisingly, we found that the source of the ectopic hair cells was columnar epithelial cells located outside the sensory epithelium in the greater epithelial ridge, which normally give rise to inner sulcus cells. Moreover, Math1 expression also facilitated conversion of postnatal utricular supporting cells into hair cells. Thus Math1 was sufficient for the production of hair cells in the ear, and immature postnatal mammalian inner ears retained the competence to generate new hair cells.

Heregulin enhances regenerative proliferation in postnatal rat utricular sensory epithelium after ototoxic damage

Hair cell loss due to acoustic and ototoxic damage often leads to hearing and balance impairments. Although a spontaneous event in chicks and lower vertebrates, hair cell replacement occurs at a much lower frequency in mammals presumably due to a very low rate of supporting cell proliferation following injury. We report here that heregulin, a member of the neuregulin family, dramatically enhances proliferation of supporting cells in postnatal rat utricular epithelial sheet cultures after gentamicin treatment, as revealed by bromo-deoxyuridine (BrdU) immunocytochemistry. A dose-dependent study shows that the maximal effects of heregulin are achieved at 3 nM. The mitogenic effects of heregulin are confirmed in utricular whole mount cultures. Autoradiography of the utricular whole mount cultures shows that heregulin also enhances the number of tritiated thymidine-labeled cells within the hair cell layer. TaqMan quantitative RT-PCR analysis and immunocytochemistry reveal that heregulin and its binding receptors (ErbB-2, ErbB-3 and ErbB-4) are expressed in the inner ear sensory epithelium. Of several ligands activating various ErbB receptors, including heregulin, neuregulin-3, beta-cellulin, heparin binding-epidermal growth factor (HB-EGF), transforming growth factor-alpha (TGF-alpha) and EGF, heregulin shows the most potent mitogenic effects on supporting cells. Because neuregulin-3 that signals only through ErbB-4 does not show an effect, these data suggest that activation of the ErbB-2-ErbB-3 heterodimeric complexes, rather than ErbB-4, is critical for the proliferative response in the utricular sensory epithelium. In addition, gentamicin treatment induces an upregulation of heregulin mRNA. Considered together, heregulin may play an important role in hair cell regeneration following ototoxic damage.

Concanavalin A protects hair cells against gentamicin ototoxicity in rat cochlear explant cultures

Degeneration of hair cells and spiral ganglion neurons due to acoustic trauma and various ototoxins is a major cause of hearing loss. Although our previous study demonstrates that specific neurotrophins protect spiral ganglion neurons from ototoxic insult, they do not protect hair cells. In the present experiments, we used postnatal rat cochlear explant cultures to identify molecules that protect hair cells from ototoxic damage. Of 51 compounds examined, only concanavalin A (Con A) significantly protected hair cells from gentamicin. A dose-dependent study of Con A showed that maximal protection occurred at 100 nM. The protective effects of Con A on hair cells were confirmed with confocal microscopy and paraffin sectioning of the cultures. Several experiments were performed to examine the mechanism of protection by Con A. Incubation of Con A with gentamicin did not form a complex and coaddition of Con A and gentamicin to Escherichia coli cultures did not interfere with the antibiotic activity of gentamicin. However, Lyso-Tracker staining and gentamicin immunocytochemistry provided evidence that preincubation with Con A blocked gentamicin uptake into hair cells. Considered together, these findings may help elucidate the ototoxic mechanism of aminoglycoside antibiotics, and suggest that Con A may be of therapeutic value in prevention of aminoglycoside-induced hearing loss.

Immunocytochemical and morphological evidence for intracellular self-repair as an important contributor to mammalian hair cell recovery

Although recent studies have provided evidence for hair cell regeneration in mammalian inner ears, the mechanism underlying this regenerative process is still under debate. Here we report immunocytochemical, histological, electron microscopic, and autoradiographic evidence that, in cultured postnatal rat utricles, a substantial number of hair cells can survive gentamicin insult even their stereocilia are lost. These partially damaged hair cells can survive for a prolonged time and regrow the stereocilia. Although the number of stereocilia-bearing hair cells increases over time after gentamicin insult, hair cell and supporting cell numbers remain essentially unchanged. Tritiated thymidine autoradiography and bromodeoxyuridine immunocytochemistry of the cultures demonstrate that cell proliferation in the sensory epithelium is very limited and is far below the number of recovered hair cells. Furthermore, terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end labeling analysis indicates that gentamicin-induced apoptosis in the sensory epithelium occurs mainly during a 2 d treatment period, and additional cell death is minimal 2-11 d after treatment. Considered together, intracellular repair of partially damaged hair cells can be an important contributor to spontaneous hair cell recovery in mammalian inner ears.

Regulation of hippocampal synaptic plasticity by the tyrosine kinase receptor, REK7/EphA5, and its ligand, AL-1/Ephrin-A5

The Eph-related tyrosine kinase receptor, REK7/EphA5, mediates the effects of AL-1/Ephrin-A5 and related ligands and is involved in the guidance of retinal, cortical, and hippocampal axons during development. The continued expression of REK7/EphA5 in the adult brain, in particular in areas associated with a high degree of synaptic plasticity such as the hippocampus, raises the question of its function in the mature nervous system. In this report we examined the role of REK7/EphA5 in synaptic remodeling by asking if agents that either block or activate REK7/EphA5 affect synaptic strength in hippocampal slices from adult mouse brain. We show that a REK7/EphA5 antagonist, soluble REK7/EphA5-IgG, impairs the induction of long-term potentiation (LTP) without affecting other synaptic parameters such as normal synaptic transmission or paired-pulse facilitation. In contrast, perfusion with AL-1/Ephrin-A5-IgG, an activator of REK7/EphA5, induces a sustained increase in normal synaptic transmission that partially mimics LTP. The sustained elevation of normal synaptic transmission could be attributable to a long-lasting binding of the AL-1/Ephrin-A5-IgG to the endogenous REK7/EphA5 receptor, as revealed by immunohistochemistry. Furthermore, maximal electrical induction of LTP occludes the potentiating effects of subsequent treatment with AL-1/Ephrin-A5-IgG. Taken together these results implicate REK7/EphA5 in the regulation of synaptic plasticity in the mature hippocampus and suggest that REK7/EphA5 activation is recruited in the LTP induced by tetanization.

Establishment of conditionally immortalized rat utricular epithelial cell lines using a retrovirus-mediated gene transfer technique

Supporting cells in the inner ear sensory epithelium are most likely hair cell progenitors. In an effort to establish an in vitro model system of hair cell differentiation, we developed immortalized epithelial cell lines by transferring the tsA58 allele of the SV40 large T antigen oncogene into neonatal rat utricular supporting cells using a retrovirus. The established cell lines have been stably maintained continuously for more than 25 passages and display many features similar to primary supporting cells. They grow in patches and assume a polygonal morphology. Immunocytochemical characterization of the established cell lines reveals that these cells can be labeled by epithelial cell markers, but not by fibroblast, glial or neuronal markers. The immortalized cells grow rapidly in serum medium at permissive temperature, but the majority cease proliferation when cultured in serum free medium at non-permissive temperature. These cells respond to mitogenic growth factors including bFGF, EGF and TGF-alpha and express growth factor receptors in a manner similar to the primary supporting cells. Furthermore, we find that the cells undergo a morphological differentiation when cultured in serum free medium at non-permissive temperature in the presence of bFGF. Under these conditions, the cells shrink in size, become elongated, and express early hair cell markers such as calretinin and calmodulin. The utricular epithelial cell line we have established may potentially provide an invaluable system for studying hair cell differentiation and regeneration.

Analysis of rat vestibular hair cell development and regeneration using calretinin as an early marker

Despite increased interest in inner ear hair cell regeneration, it is still unclear what exact mechanisms underlie hair cell regeneration in mammals because of our limited understanding of hair cell development and the lack of specific hair cell markers. In this report, we studied hair cell development using immunohistochemistry on sections prepared from embryonic day (E) 13 to postnatal day 7 rat inner ear tissues. Of many epithelial, neuronal, and glial markers, we found that calcium-binding protein antibodies recognizing calretinin, calmodulin, or parvalbumin labeled immature hair cells in rat vestibular end organs. In particular, calretinin antiserum labeled the initial differentiating hair cells at E15, a stage immediately after the terminal mitosis of hair cell progenitors. The selective immunoreactivity of postmitotic presumptive hair cells, but not supporting cells or peripheral epithelial cells, was confirmed in utricular epithelial sheet cultures. Double labeling with calretinin and bromodeoxyuridine antibodies in long-term cultures showed that only a few mitotic utricular supporting cells became calretinin positive. Thus, although proliferation-mediated regeneration of new hair cells might directly contribute to hair cell regeneration in rat utricles after injury, it is very limited. In addition, double labeling with calretinin and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) revealed that differentiated hair cells underwent apoptosis during normal development at late embryonic and early postnatal stages in vivo and in vitro. Therefore, these experiments lay the groundwork for the time course of differentiation, regeneration, and apoptosis of mammalian vestibular hair cells. This work also suggests that calcium-binding proteins are useful markers for studies on inner ear hair cell differentiation and regeneration.

Induction of cell proliferation by fibroblast and insulin-like growth factors in pure rat inner ear epithelial cell cultures

Proliferation of supporting cells in the inner ear is the early major event occurring during hair cell regeneration after acoustic trauma or aminoglycoside treatment. In the present study, we examined the possible influence of 30 growth factors on the proliferation of pure rat utricular epithelial cells in culture. Utricular epithelial sheets were separated and partially dissociated from early postnatal rats via a combined enzymatic and mechanical method. The cultured utricular epithelial cells expressed exclusively epithelial cell antigens, but not fibroblast, glial, or neuronal antigens. With tritiated thymidine incorporation assays, we found that several fibroblast growth factor (FGF) family members, insulin-like growth factor-1 (IGF-1), IGF-2, transforming growth factor-alpha (TGF-alpha), and epidermal growth factor (EGF), stimulated proliferation of the utricular epithelial cells. In contrast, neurotrophins and other growth factors did not elicit any detectable mitogenic effects. Among all of the growth factors examined, FGF-2 was the most potent mitogen. When FGF-2 was added in combination with IGF-1 or TGF-alpha to the medium, combined effects were seen. These results were confirmed with BrdU immunocytochemistry. Thus, the present culture system provides a rapid and reliable assay system to screen novel growth factors involved in proliferation of mammalian inner ear supporting cells. Furthermore, immunostainings revealed that the cultured utricular epithelial cells expressed FGF and IGF-1 receptors, and utricular hair cells produced FGF-2 in vivo. The addition of neutralizing antibodies against FGF-2 or IGF-1 to the cultures significantly inhibited the utricular epithelial cell proliferation. This work suggests that FGF-2 and IGF-1 may regulate the proliferation step during hair cell development and regeneration.

Differential damage to auditory neurons and hair cells by ototoxins and neuroprotection by specific neurotrophins in rat cochlear organotypic cultures

Therapeutic ototoxic drugs are one of the major causes of damage in the peripheral auditory system, leading to hearing loss. In this study, we have examined the toxic actions of three classes of ototoxins (sodium salicylate, gentamicin and cisplatin) in organotypic cultures of postnatal cochlear explants. In these cultures, afferent innervation of hair cells by primary auditory neurons remained intact. Double labelling with a monoclonal antibody against neurofilament protein and a phalloidin-fluorescein isothiocyanate conjugate revealed that the three types of drugs induced differential damage to auditory neurons and hair cells in the cochlea. While gentamicin preferentially caused hair cell death, sodium salicylate specifically induced degeneration of auditory neurons. In contrast, cisplatin resulted in destruction of both auditory neurons and hair cells. Neuronal degeneration was largely prevented by the addition of neurotrophin-4/5, brain-derived neurotrophic factor and neurotrophin-3 to the culture media together with the ototoxins, while nerve growth factor and other growth factors had no effect. In contrast, the hair cell loss caused by cisplatin or gentamicin was not attenuated by the presence of neurotrophins. These results suggest that ototoxic mechanisms of salicylates, aminoglycosides and chemotherapeutic agents are different. Auditory neuronal loss induced by ototoxins may be prevented by specific neurotrophins.

Effects of M1 and M2 receptor agonists and blockers on dog respiration

AIM

To study the effects of M1 and M2 receptor agonists and blockers on dog respiration.

METHODS

Using thoracic respiratory transducer and RM-86 multipurpose polygraph to determine respiratory rate (RR), tidal volume (TV), and minute ventilation volume (MVV), and DH-100G blood gas analysis instrument to analyze pO2, pCO2 and pH.

RESULTS

Pilocarpine (Pil, an M1-R subtype agonist) 0.5, 1, and 2 mg.kg-1 iv caused increases in RR, MVV, and pO2, and a decrease in pCO2. The excitatory effects of Pil were antagonized by pretreatment with pirenzepine (Pir, 3 mg.kg-1, iv) and scopolamine (Sco, 2 mg.kg-1, iv). The iv injections of a novel M2-R subtype agonist, 6 beta-acetoxy nortropane (6 beta-AN) 2, 5, and 20 micrograms.kg-1 caused decreases in RR, MVV, and pO2 and an increase of pCO2. The actions of 6 beta-AN were antagonized by iv pretreatment with AF-DX116 ¿11-2 [[2-[(diethylamino)methyl]-1-piperidinyl] acetyl]-5, 11-dihydro-6H[2,3-b][1,4]benzodiazepine-6-one, 0.5 mg.kg-1¿ and atropine (Atr, 2 mg.kg-1). Similar results were obtained when smaller doses of Pil (0.2, 0.4, and 0.8 mg.kg-1) and 6 beta-AN (0.25, 0.5, and 1 microgram.kg-1) were injected into the vertebral artery. Pir and Sco also antagonized the excitatory effects of Pil, and AF-DX116 and Atr antagonized the inhibitory effects of 6 beta-AN on respiration.

CONCLUSION

Stimulating M1-R of the respiratory center caused excitation of the respiration while stimulating the M2-R subtype caused inhibition of the respiration.

Neurotrophin-4/5, brain-derived neurotrophic factor, and neurotrophin-3 promote survival of cultured vestibular ganglion neurons and protect them against neurotoxicity of ototoxins

The ability of neurotrophin-4/5 (NT-4/5), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and nerve growth factor (NGF) to promote survival of postnatal rat vestibular ganglion neurons (VGNs) was examined in dissociated cell cultures. Of the four neurotrophins, NT-4/5 and BDNF were equally effective but more potent than NT-3 in promoting the survival of VGNs. In contrast, NGF showed no detectable effects. As expected, TrkB-IgG (a fusion protein of extracellular domain of TrkB and Fc domain of human immunoglobulin G) specifically inhibited the survival-promoting, effects by NT-4/5 or BDNF and TrkC-IgG fusion protein completely blocked that of NT-3. Immunohistochemistry with TrkB, TrkA, and p75 antisera revealed that VGNs made TrkB and p75 proteins, but not TrkA protein. Ototoxic therapeutic drugs such as cisplatin and gentamicin often induce degeneration of hair cells and ganglion neurons in both auditory and vestibular systems that leads to impairment of hearing and balance. When cisplatin and gentamicin were added to the dissociated VGN culture in which the hair cells were absent, additional cell death of VGNs was induced, suggesting that the two ototoxins may have a direct neurotoxic effect on ganglion neurons in addition to their known toxicity on hair cells. However, if the cultures were co-treated with neurotrophins, NT-4/5, BDNF, and NT-3, but not NGF, prevented or reduced the neurotoxicity of the two ototoxins. Thus, the three neurotrophins are survival factors for VGNs and are implicated in the therapeutic prevention of VGN loss caused by injury and ototoxins.

[Inhibitory effect and mechanism of scopolamine on respiration]

In conscious rabbits, dogs and anaesthetized dogs, the respiratory frequency (FR), tidal volume (Vt) and minute ventilation (Vm) were determined in order to confirm whether the respiratory effect of scopolamine is stimulatory or inhibitory. Arterial blood samples were taken intermittently and analyzed for Po2, Pco2 and pH. When scopolamine was injected i.c.v., i.a. and i.v., the decrease of FR, Vt, Vm and Po2 and the increase of Pco2 were observed in two animals. When the drug was given in clinical doses used for treating respiratory failure, the effect was seen still observable. The results indicate that scopolamine inhibits respiration. Moreover, it was observed that excitatory effect of pilocarpine on respiration can be antagonized by scopolamine, but the inhibitory effect of 6 beta-acetoxy nortropane can not be antagonized, on the contrary, can be coordinated. The above results suggest that respiratory inhibition induced by scopolamine may be related to blocking M1-R of the respiratory center.

Neurotrophin-4/5 enhances survival of cultured spiral ganglion neurons and protects them from cisplatin neurotoxicity

Destruction of spiral ganglion neurons (SGNs) induced by injury and toxins is one of the major causes for hearing loss. Here we report that neurotrophin-4/5 (NT-4/5), a member of the nerve growth factor family, promoted survival of postnatal rat SGNs up to threefold in dissociated cell cultures. The survival-promoting potency of NT-4/5 was equivalent to that of BDNF and stronger than that of NT-3. In contrast, NGF showed no detectable effects. Immunohistochemistry, with TrkB and TrkA antisera, revealed that these neurons produced TrkB protein, the functional receptor for NT-4/5 and BDNF, but not TrkA protein, the high-affinity receptor for NGF. The survival-promoting activity of NT-4/5 was completely inhibited by TrkB-IgG fusion protein. These results suggest that NT-4/5 is a specific survival factor for SGNs. In addition, NT-4/5 protected the SGNs from neurotoxic effects of the anti-cancer drug, cisplatin. Thus, NT-4/5 may have therapeutic value in preventing hearing impairment caused by damage to primary auditory afferent neurons.

Neurotrophin-4/5 (NT-4/5) and brain-derived neurotrophic factor (BDNF) act at later stages of cerebellar granule cell differentiation

The developing cerebellum expresses genes which encode for both neurotrophins and their receptors. The present study was designed to determine at what stages during cerebellar granule cell neurogenesis neurotrophin family molecules may act. We report here that in purified, well-characterized granule cell cultures (Gao et al., 1991; 1992), none of the neurotrophins stimulated proliferation of granule cell precursors or rescued phenotypic defect of mutant weaver granule cell precursors in the initiation of neuronal differentiation. However, neurotrophin-4/5 (NT-4/5) and BDNF, but not neurotrophin-3 (NT-3) or NGF, promoted neurite extension and survival of differentiated cerebellar granule cells. Both of these effects were blocked by the specific inhibitor for Trk tyrosine kinases, K-252a. NT-4/5 and BDNF also enhanced neurite extension by weaver granule cells which were rescued by wild-type granule cells during differentiation. Moreover, TrkB immunohistochemistry performed on sections of the developing wildtype and weaver cerebella revealed that only differentiated granule cells, but not the precursor cells, make high levels of TrkB receptor. These findings together suggest that NT-4/5 and BDNF promote the maturation and maintenance of differentiated granule cells, effects which are downstream to the weaver gene. Since no additive effects were seen with the combination of NT-4/5 and BDNF, it seems likely that the two neurotrophins activate the same receptor trkB for signal transduction.

[Muscarinic receptor subtypes in respiratory center and their functions]

Radioreceptor binding assays using [3H]quinuclidinyl benzilate and [3H]pirenzepine were performed on the pons and medulla oblongata (MeOb) of rat brain. The M1 cholinergic receptor (M1-R) was found to account for approximately 30-40% of the total muscarinic receptors (M-R) in the pons and MeOb, and the M2 accounted for about 60-70%. The receptor binding capacities of scopolamine and atropine were compared with those of pirenzepine (Pir) and AF-DX 116 on the 2 parts of the brain. The affinity values (pKi) suggest that the selectivity of scopolamine for M1-R is greater than for M2-R, and that of atropine for M2 is greater than for M1. In conscious rabbits, the respiratory frequency (FR), tidal volume (TV), and minute ventilation volume (MVV) were determined. Arterial blood samples were taken intermittently and analyzed for pO2, pCO2, and pH. When pilocarpine (a M1-R subtype selective agonist) was given, excitatory effects on respiration were seen through FR, TV, MVV, and the pO2, pCO2, and pH. When 6 beta-acetoxy nortropane (6 beta-AN, a novel M2-R subtype selective agonist) was given, the effects were inhibitory. These results were reversed after administration of Pir, scopolamine, AF-DX 116, and atropine. Thus, it shows that Pir and scopolamine inhibit respiration by blocking the M1-R subtype of the respiratory center, while the excitatory effects of AF-DX 116 and atropine are brought about by blocking the M2-R subtype of the respiratory center.

[Experimental study on the transplantation of demineralized bone and bone morphogenetic protein (BMP)]

Solid and powdered grafts of demineralized allogenic or xenogenic bone were implanted in rats and rabbits cranial defects and abdomen muscle. Demineralized bone powder (DBP) and bone morphogenetic protein (BMP) healed the defects, as judged by histology, 45Ca incorporation and culture of bone blastocyte (3H-TdR uptake) studies. Histologic evaluation demonstrated predictable osteoinduction by DBP, solid bone and BMP. It shows that BMP might also be a stimulation on the mesenchymal cells to induce their transformation into bone forming cells.