[Research progress on novel antiviral therapeutic drugs for chronic hepatitis B]

The ideal goal of hepatitis B treatment is to achieve a functional cure, and the persistent cccDNA in the liver is a barrier to functional cure. Currently, antiviral drugs represented by pegylated interferon-α and nucleos (t) ide analogues cannot eliminate cccDNA, which is difficult to achieve functional cure. With the deepening of the exploration of various mechanisms and drug targets, significant progress has been made in the research and development of several novel drugs targeting the hepatitis B virus's life cycle and immune system, offering hope for a functional cure. This article presents an overview of the new progress in clinical research on antiviral therapy for chronic hepatitis B based on the literature published in recent years and international conference materials.

Effectiveness of Taohong Siwu decoction in the prevention of deep vein thrombosis in hip surgery patients: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

This systematic review and meta-analysis aimed to evaluate the effects of Taohong Siwu Decoction (THSWD) combined with low molecular weight heparin (LMWH), as well as THSWD alone, on the incidence of Deep vein thrombosis (DVT), D-dimer levels, prothrombin time (PT), activated partial thromboplastin time (APTT), visual analogue scale (VAS) pain score, and calf swelling in patients undergoing hip fracture or replacement surgery, compared to LMWH.

METHODS

According to the predefined inclusion criteria, we conducted a comprehensive search for randomized controlled trials (RCTs) examining the efficacy of THSWD combined with LMWH or THSWD compared to LMWH in patients with hip fractures or undergoing replacement surgery. The search was performed across multiple databases including China National Knowledge Internet, WanFang, Sinomed, Duxiu, PubMed, Embase, Google Scholar, Cochrane, and Web of Science from their inception until December 2023. Additionally, relevant literature references were retrieved and hand searching of pertinent journals was conducted. The methodological quality assessment of the included trials was carried out following the guidelines outlined in the Cochrane Handbook. Review Manager 5.4 was applied in analyzing and synthesizing.

RESULTS

A total of 18 RCTs with 1353 patients were included. The results of meta-analysis showed that compared with the control group, the combined group had a better effect on the incidence of DVT [RR = 0.32, 95% CI(0.17, 0.58; P = .0002], D-dimer [SMD = -5.88, 95% CI(-7.66, -4.11); P < .00001], VAS [MD = -1.16, 95% CI(-1.81, -0.50); P = .0005], Calf circumference difference [MD = -0.56, 95% CI(-1.05, -0.08); P = .02]. There was no significant difference in PT and APTT between the combined group and the control group. Meta-analysis results show that the D-dimer, incidence of DVT, PT, and APTT did not significantly differ between the THSWD and the LMWH groups.

CONCLUSION

This meta-analysis shows that compared with LMWH, THSWD combined with LMWH has a better efficacy in the treatment of DVT after hip surgery, without a significant increase in the incidence of adverse events. Additionally, the combined therapy can also reduce D-dimer, VAS, and swelling. However, due to the limitations of the included studies (such as small sample size and low-quality evidence), the results need to be further verified in more rigorous multicenter clinical trials with a large sample size.

Comparison of postoperative complications in mediastinal lymph node dissection versus mediastinal lymph node sampling for early stage non-small cell lung cancer: Protocol for a systematic review and meta-analysis

INTRODUCTION

Lung cancer is the primary cause of cancer-related deaths worldwide, with high rates of morbidity and mortality. The most effective treatment for early stage (I-II) non-small cell lung cancer (NSCLC) is surgical resection. However, the extent of mediastinal lymph nodes removal required and the impact of their removal remains controversial. This systematic review and meta-analysis aimed to evaluate the postoperative complications in patients with stage I-II NSCLC who received mediastinal lymph node dissection (MLND) or mediastinal lymph node sampling (MLNS).

METHODS AND ANALYSIS

According to the predefined inclusion criteria, we will conduct a comprehensive search for randomized controlled trials (RCTs) and observational studies examining the postoperative complications of MLND compared to MLNS in patients with stage I-II NSCLC. The search will be performed across multiple databases including PubMed, Embase, the Cochrane Library, CNKI, WanFang, Sinomed, VIP, Duxiu, and Web of Science from inception to February 2024. Additionally, relevant literature references will be retrieved and hand searching of pertinent journals will be conducted. Screening, data extraction, and quality assessment will be performed by two independent reviewers. Review Manager 5.4 will be applied in analyzing and synthesizing. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) will be used to assess the quality of evidence for the whole RCTs and used Newcastle-Ottawa scale to assess the methodologic quality of observational studies.

ETHICS AND DISSEMINATION

This study did not include personal information. Ethical approval was not required for this study. This study is based on a secondary analysis of the literature, so ethical review approval is not required. The final report will be published in a peer-reviewed journal.

CONCLUSION

This systematic review will contribute to compare the safety and survival benefits of these two surgical techniques for the treatment of early stage NSCLC, to further guide the selection of surgical approaches.

TRIAL REGISTRATION

The protocol of the systematic review has been registered on Open Science Framework, with a registration number of DOI https://doi.org/10.17605/OSF.IO/N2Y5D.

The levels of IL1RN is a factor influencing the onset of rheumatoid arthritis in non-alcoholic fatty liver disease

With the improvement of global dietary conditions, non-alcoholic fatty liver disease (NAFLD) has gradually become prevalent. As the number of NAFLD patients increases, the coexistence of diseases associated with it has come into focus. In this study, based on immune phenotypes, intercellular communication activities, and clinical manifestations of NAFLD patients, IL1RN was identified as a central pro-inflammatory factor. Subsequently, potential downstream biological pathways of IL1RN in liver tissues and various cell types were enriched to describe its functions. Transcription factors Nfkb1, Jun, and Sp1, significantly associated with these functions, were also enriched. Functional studies of IL1RN suggest its potential to trigger autoimmune diseases. Given this, Mendelian randomization analysis was used to explore the causal relationship between NAFLD and various autoimmune diseases, with IL1RN considered as an intermediary introduced into Mendelian randomization studies. The results indicate that IL1RN and its partially related proteins play a certain mediating role in the process of NAFLD inducing rheumatoid arthritis (RA). Finally, additional research results suggest that intrahepatic ALT levels may influence IL1RN levels, possibly through amino acid metabolism.

Phosphoantigens glue butyrophilin 3A1 and 2A1 to activate Vγ9Vδ2 T cells

In both cancer and infections, diseased cells are presented to human Vγ9Vδ2 T cells through an 'inside out' signalling process whereby structurally diverse phosphoantigen (pAg) molecules are sensed by the intracellular domain of butyrophilin BTN3A11-4. Here we show how-in both humans and alpaca-multiple pAgs function as 'molecular glues' to promote heteromeric association between the intracellular domains of BTN3A1 and the structurally similar butyrophilin BTN2A1. X-ray crystallography studies visualized that engagement of BTN3A1 with pAgs forms a composite interface for direct binding to BTN2A1, with various pAg molecules each positioned at the centre of the interface and gluing the butyrophilins with distinct affinities. Our structural insights guided mutagenesis experiments that led to disruption of the intracellular BTN3A1-BTN2A1 association, abolishing pAg-mediated Vγ9Vδ2 T cell activation. Analyses using structure-based molecular-dynamics simulations, 19F-NMR investigations, chimeric receptor engineering and direct measurement of intercellular binding force revealed how pAg-mediated BTN2A1 association drives BTN3A1 intracellular fluctuations outwards in a thermodynamically favourable manner, thereby enabling BTN3A1 to push off from the BTN2A1 ectodomain to initiate T cell receptor-mediated γδ T cell activation. Practically, we harnessed the molecular-glue model for immunotherapeutics design, demonstrating chemical principles for developing both small-molecule activators and inhibitors of human γδ T cell function.

Identify the key emission sources for mitigating ozone pollution: A case study of urban area in the Yangtze River Delta region, China

Ozone (O₃) has become the most critical air pollutant in the Yangtze River Delta (YRD) region of China. Research on the O₃ formation mechanism and its precursor sources (including nitrogen oxides (NO_X) and volatile organic compounds (VOCs)) could provide a theoretical basis for mitigating O₃ pollution in this region. In this study, simultaneous field experiments were conducted for air pollutants in a typical urban area (Suzhou) in the YRD region in 2022. The capacity of in-situ O₃ formation, O₃-NO_X-VOCs sensitivities and sources of O₃ precursors were analyzed. The results showed that in-situ formation contributed 22 % of the O₃ concentration in the warm season (April to October) of the Suzhou urban area. Compared with the warm season average, the concentrations of various O₃ precursors increased on pollution days. The O₃-NO_X-VOCs sensitivity was the VOCs-limited regime based on the average concentrations during the warm season. O₃ formation was most sensitive to anthropogenic VOCs, of which oxygenated VOCs, alkenes and aromatics were the key species. There was a VOCs-limited regime in spring and autumn, while a transitional regime in summer due to the changes in NO_X concentrations. This study considered NO_X emission from VOCs sources and calculated the contribution of various sources to O₃ formation. The results of VOCs source apportionment showed that diesel engine exhaust and fossil fuel combustion had a dominant proportion, but O₃ formation presented significant negative sensitivities to the above two sources because of their high NO_X emissions. There were significant sensitivities of O₃ formation to gasoline vehicle exhaust and VOCs evaporative emissions (gasoline evaporation and solvent usage). The contribution of VOCs evaporative emissions during the O₃ pollution episode was significantly higher than the average; therefore, controlling VOCs evaporative emissions during the O₃ pollution episode is critical. These results provide feasible strategies to mitigate O₃ pollution.

The carbon components in indoor and outdoor PM2.5 in winter of Tianjin

To study the carbon components in indoor and outdoor PM2.5, the samples of PM2.5 were collected from Nankai University in December 2015. The contents of eight carbon components were analyzed to use the thermo-optical reflection method. The results indicated that organic carbon (OC) mass concentration was 17.01, 19.48 and 18.92 µg/m3 in outdoor, dormitory and laboratory; elemental carbon (EC) mass concentration was 7.97, 3.56 and 3.53 µg/m3 in outdoor, dormitory and laboratory; and the total carbon aerosol was the proportion of more than 23% of PM2.5 samples. Lower wind speed and higher relative humidity were helpful to the accumulation of PM2.5. The ratio of OC/EC was > 2, and the SOC/OC ratio was > 30%, indicating that SOC was a crucial component indoors and outdoors. About 72% and 85% of the outdoor OC entering dormitory and laboratory environment, and about 59% and 71% of the outdoor EC entering dormitory and laboratory environment. Factor analysis of the eight carbon fractions indicated that the sources of OC and EC in outdoor, dormitory and laboratory is different.

Docking Complete: A Step Further toward the Holy Grail of γδ T Cell Biology

The direct ligands recognized by γδ T cell receptors (γδ TCRs) remain uncertain and controversial. In a study appearing in this issue, Willcox et al. use surface plasmon resonance and isothermal titration calorimetry to demonstrate that B7-like molecule BTNL3 makes physical contact with V4γ-bearing TCRs on γδ T cells.

MiR-17-5p promotes cervical cancer cell proliferation and metastasis by targeting transforming growth factor-β receptor 2

OBJECTIVE

MicroRNAs (miRNAs) play critical roles in post-translational gene expression. The aim of the current study was to investigate the effects of miR-17-5p in cervical cancer.

PATIENTS AND METHODS

Fifteen clinical cervical cancer tissue samples, as well as their paired adjacent noncancerous tissues, were collected. The microarray was performed to identify differential miRNAs in cervical cancer. Luciferase reporter assay was conducted to identify the target gene of selected miRNA. SiHa was transfected with mimics, inhibitors as well as negative controls of miR-17-5p and Targeting Transforming Growth Factor-β Receptor 2 (TGFBR2) open reading frame or siRNA. Cell counting kit-8 (CCK-8) assay and transwell experiment were performed to detect the proliferation rate and metastasis, respectively. Western blotting and quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) analysis were used to analyze TGFBR2 expression. Balb/c nude mice were utilized to verify the effect of miR-17-5p in vivo.

RESULTS

Microarray analysis identified miR-17-5p as our interesting miRNA, and luciferase reporter assay identified TGFBR2 as its target gene. MiR-17-5p overexpression significantly enhanced cervical cancer cell proliferation and metastasis. In-vivo study also verified that miR-17-5p overexpression stimulated cervical cancer growth.

CONCLUSIONS

MiR-17-5p enhances cervical cancer proliferation and metastasis via targeting TGFBR2. It is proposed that targeting miR-17-5p may be a promising therapeutic approach for cervical cancer.

[Predictive value of neutrophil-to-lymphocyte ratio in 30-day mortality of patients with acute paraquat poisoning]

Objective: To investigate the predictive value of neutrophil-to-lymphocyte Ratio (NLR) in 30-day mortality of patients with acute paraquat poisoning. Methods: We respectively reviewed the clinical parameters of 115 patients with acute paraquat poisoning. They were divided into survival (n=64) and non-survival (n=51) groups based on their 30-day outcome. Multivariate logistic regression was performed to identify risk factors of 30-day mortality. Receiver operating curve (ROC) test was applied to analysis to the predictive value of NLR in 30-day mortality ofacute paraquat poisoning patients. The correlations between NLR and severity index of paraquat poisoning (SIPP) were analyzed using Spearman's rank correlation coefficient. Results: Of the 115patients included in the study, 54 (46.96%) patients were males and 61 (53.04%) were females with a mean age of 38.96±13.58 years. The total mortality in 30-day was 44.35% (51/115) . The NLR at admission was an independently risk factor of 30-day mortality of patients with acute paraquat poisoning (OR 1.477, 95%CI 1.035-2.107, P<0.05) . The NLR to predict the death of the area under the ROC curve was 0.894 (95%CI: 0.8212-0.9663, P<0.01) ; the optimal cutoff threshold was 11.71; the sensitivity was 71.79% and the specificity was 94.29%; the positive predictive value was 93.33%and negative predictive value of 75.00%. Meanwhile, the positive likelihood ratio was 12.57 and the negative likelihood ratio was 0.30. The NLR was significantly associated with SIPP (Spearman rho 0.525; P<0.01) and it was significantly higher in patients with SIPP of ten or higher than in those with an SIPP less than 10 (15.02±12.40 vs. 6.19±2.54, P<0.05) . Conclusion: The increased NLR at admission was an independently risk factor of 30-day mortality of patients with acute paraquat poisoning and it was significantly correlated with SIPP score. Therefore, NLR was useful for predicting prognosis of patients with acute paraquat poisoning.

Duloxetine use in chronic painful conditions--individual patient data responder analysis

Background

Duloxetine has been studied in four distinct chronic pain conditions – osteoarthritis (OA), fibromyalgia, chronic low back pain (CLBP) and diabetic peripheral neuropathic pain (DPNP). These trials have involved large numbers of patients with at least moderate pain, and have used similar methods for recording pain intensity, over about 12 weeks.

Methods

Data from the trials were pooled according to painful condition, and reanalysed at the level of the individual patient and using increasing levels of pain intensity reduction (<15%, 15–29%, 30–49%, ≥50%), with different imputation methods on withdrawal.

Results

The proportion of patients recording at least 50% pain intensity reduction plateaued after 2–6 weeks in fibromyalgia, and 8–12 weeks in other conditions. The duloxetine-specific benefit [number needed to treat (NNT) for at least 50% pain intensity reduction] was fairly constant after about 2 weeks for DPNP and fibromyalgia and after about 4 or 5 weeks for OA and CLBP. In all conditions, responses were bimodal, with patients generally experiencing either very good or very poor pain relief. Last-observation-carried-forward imputation produced numerically and occasionally statistically better (lower) NNTs than use of baseline-observation-carried-forward (true response).

Conclusions

Baseline-observation-carried-forward (true response), which combines the success of high levels of pain relief with the failure to experience pain relief on withdrawal of the drug is conservative and probably reflective of clinical practice experience. The distribution of effect was not normal; few patients had the average response and averages are not an appropriate descriptor for these data.

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Paradoxical role of autophagy in the dysplastic and tumor-forming stages of hepatocarcinoma development in rats

Many reports have shown that autophagy has a role as both a promoter and inhibitor in tumor development. However, the mechanism of this paradox is unknown. Tumor development is a multistep process. Therefore, we investigated whether the role of autophagy in hepatocarcinoma formation depended on the stage of tumor development. Based on our results, autophagy inhibition by chloroquine had a tumor-promotive effect in the rat model with N-diethylnitrosamine-induced hepatocarcinogenesis in its dysplastic stage (Ds) and a tumor-suppressive effect in its tumor-forming stage (Ts). In the Ds, autophagy inhibition enhanced cell proliferation, DNA damage and inflammatory cytokines expression in liver. These changes were dependent on the upregulation of reactive oxygen species (ROS) that was resulted from autophagy inhibition, and ultimately accelerated the process of hepatocarcinogenesis. However, in the Ts, autophagy inhibition restrained tumor formation by decreasing tumor cell survival and proliferation. In this stage, autophagy inhibition led to excessive ROS accumulation in the tumor, which promoted cell apoptosis, and prominently suppressed tumor cell metabolism. Taken together, our data suggested that autophagy suppressed hepatocarcinogenesis in the Ds by protecting normal cell stability and promoted hepatocarcinogenesis in the Ts by supporting tumor cells growth. Autophagy always had a role as a protector throughout the process of hepatocarcinoma development.

Long-term protective effects of methamphetamine preconditioning against single-day methamphetamine toxic challenges

Methamphetamine (METH) use is associated with neurotoxic effects which include decreased levels of dopamine (DA), serotonin (5-HT) and their metabolites in the brain. We have shown that escalating METH dosing can protect against METH induced neurotoxicity in rats sacrificed within 24 hours after a toxic METH challenge. The purpose of the current study was to investigate if the protective effects of METH persisted for a long period of time. We also tested if a second challenge with a toxic dose of METH would cause further damage to monoaminergic terminals. Saline-pretreated rats showed significant METH-induced decreases in striatal DA and 5-HT levels in rats sacrificed 2 weeks after the challenge. Rats that received two METH challenges showed no further decreases in striatal DA or 5-HT levels in comparison to the single METH challenge. In contrast, METH-pretreated rats showed significant protection against METH-induced striatal DA and 5-HT depletion. In addition, the METH challenge causes substantial decreases in cortical 5-HT levels which were not further potentiated by a second drug challenge. METH preconditioning provided almost complete protection against METH -induced 5-HT depletion. These results are consistent with the idea that METH pretreatment renders the brain refractory to METH-induced degeneration of brain monoaminergic systems.

Novel biophysical techniques for investigating long-term cell adhesion dynamics on biomaterial surfaces

Cell adhesion on biomaterial surface is crucial for the regeneration and function of clinically viable cell and tissues. In turn, the cellular phenotypes, following the mechanochemical transduction of adherent cells on biomaterials, are directly correlated to the biophysical responses of cells. However, the lack of an integrated bio-analytical system for probing the cell-substrate interface poses significant obstacles to understanding the behavior of cells on biomaterial surface. We have developed a novel method, based on the principle of confocal reflectance interference contrast microscopy (C-RICM) that has enabled us to study the biomechanical deformation of cells on biomaterial surfaces. In this article, we would like to describe our recent development of the C-RICM system that integrates a confocal fluorescence microscope, phase contrast microscope and GFP expression system. We shall demonstrate the system by determining the adhesion contact kinetics, initial deformation rate, cytoskeleton structures of adherent cells on extracellular matrices (e.g., collagen and fibronectin) and biodegradable polymer (e.g., poly(lactic acid)) during long-term culture. We shall demonstrate that this unique approach could provide valuable biophysical information necessary for designing optimized biomaterial surfaces for cell/tissue regeneration applications.

A tumor-specific conditionally replicative adenovirus vector expressing TRAIL for gene therapy of hepatocellular carcinoma

We constructed a novel hepatocellular carcinoma-specific conditionally replicative adenovirus (CRAd). This adenovirus, designated Ad.HS4.AFP.E1A/TRAIL, expresses E1A to mediate viral replication and TRAIL to enhance HCC-killing efficacy under the control of a modified AFP promoter. An insulator HS-4 was placed in front of the AFP promoter to enhance the fidelity of the heterologous promoter. This virus was shown to have specific cytolytic activity in AFP-expressing HCC cells in vitro. Furthermore, the replication efficiency of Ad.HS4.AFP.E1A/TRAIL correlated well with AFP expression of the host cells, showing a 100-fold and 1 000 000-fold decrease in the low-and non-AFP-expressing HCC cells, respectively, compared to the high AFP-expressing HCC cells. An increase in mRNA of TRAIL and the elevated Caspase-3 activity were also observed in Ad.HS4.AFP.E1A/TRAIL-infected HCC cells. These results indicated that TRAIL expression from the viral vector activated the Caspase-3 enzymatic capacity and the HCC cells were sensitive to TRAIL. In vivo, Ad.HS4.AFP.E1A/TRAIL effectively prevented the growth of low AFP-expressing BEL-7404 xenografts. These results indicate that Ad.HS4.AFP.E1A/TRAIL could provide a new strategy of gene therapy for HCC.

Automatic analysis of image of surface structure of cell wall-deficient EVC

Some computer applications for cell characterization in medicine and biology, such as analysis of surface structure of cell wall-deficient EVC (El Tor Vibrio of Cholera), operate with cell samples taken from very small areas of interest. In order to perform texture characterization in such an application, only a few texture operators can be employed: the operators should be insensitive to noise and image distortion and be reliable in order to estimate texture quality from images. Therefore, we introduce wavelet theory and mathematical morphology to analyse the cellular surface micro-area image obtained by SEM (Scanning Electron Microscope). In order to describe the quality of surface structure of cell wall-deficient EVC, we propose a fully automatic computerized method. The image analysis process is carried out in two steps. In the first, we decompose the given image by dyadic wavelet transform and form an image approximation with higher resolution, by doing so, we perform edge detection of given images efficiently. In the second, we introduce many operations of mathematical morphology to obtain morphological quantitative parameters of surface structure of cell wall-deficient EVC. The obtained results prove that the method can eliminate noise, detect the edge and extract the feature parameters validly. In this work, we have built automatic analytic software named "EVC.CELL".

Endogenous BDNF protein is increased in adult rat hippocampus after a kainic acid induced excitotoxic insult but exogenous BDNF is not neuroprotective

Systemic administration of the excitotoxin kainic acid to adult rats results in a well defined pattern of loss of the CA1 and CA3 pyramidal neurons of the hippocampus. Prior to this neuronal loss, brain-derived neurotrophic factor (BDNF) mRNA is substantially increased. We show here that BDNF protein is increased after excitotoxic insult in specific areas of the hippocampus, reaching maximal levels 24 h after the insult. BDNF protein levels in the hippocampus increase in direct relation to the severity of seizure. Up to 7 days after injection of kainic acid, levels of full-length TrkB protein were unchanged, whereas levels of truncated TrkB protein were significantly increased by 12 h. To determine whether elevations in BDNF protein levels are potentially beneficial to hippocampal neurons exposed to an excitotoxic stress, we infused exogenous BDNF prior to and during the period of neuronal death caused by kainic acid. We find that administration of high levels of exogenous BDNF does not affect severity of seizure, but does in fact, exacerbate the injury caused by kainic acid, specifically to CA3 pyramidal neurons. Although there was a trend toward sparing of CA1 pyramidal neurons on the side infused with BDNF, this was not significant. In the same paradigm, infusion of exogenous NT-3 had no effect.

Anterograde transport of brain-derived neurotrophic factor and its role in the brain

The role of neurotrophins as target-derived proteins that promote neuron survival following their retrograde transport from the terminals to the cell bodies of neurons has been firmly established in the developing peripheral nervous system. However, neurotrophins appear to have more diverse functions, particularly in the adult central nervous system. Brain-derived neurotrophic factor (BDNF), for example, produces a variety of neuromodulatory effects in the brain that are more consistent with local actions than with long-distance retrograde signalling. Here we show that BDNF is widely distributed in nerve terminals, even in brain areas such as the striatum that lack BDNF messenger RNA, and that inhibition of axonal transport or deafferentation depletes BDNF. The number of striatal neurons that contain the calcium-binding protein parvalbumin was decreased in BDNF+/- and BDNF-/- mice in direct proportion to the loss of BDNF protein, which is consistent with anterogradely supplied BDNF having a functional role in development or maintenance. Thus the anterograde transport of BDNF from neuron cell bodies to their terminals may be important for the trafficking of BDNF in the brain.

[The clinical features and long-term follow-up of atrial fibrillation or atrial flutter complicating Wolff-Parkinson-White syndrome]

Twenty six patients (20 male, 6 female, aged 50 +/- 14) with recurrent episodes of atrial fibrillation or atrial flutter (Af/AF) associated with WPW syndrome were retrospectively studied and followed. During Af/AF, 17 patients showed ventricular preexcitation. Of them, 15 patients had hypotention, 8 syncope, 4 precipitating acute heart failure and 4 spontanous degenerated into ventricular fibrillation. Hypotention was found only in 2 of the 9 patients without pre-excited ventricular beats. The mean shortest prexcited R-R intervals of the former were shorter (247 +/- 47 ms) and the average ventricular rates (198 +/- 43 beat/min) were faster than those of the latter (393 +/- 80 ms & 144 +/- 22 beat/min) respectively (P < 0.01). When pre-excited Af/AF occurred, both cardioversion and antiarrhythmic agents of class I and II had marked effect in terminating the Af/AF or slowing pre-exicted ventricular responses. Digitalis and verapamil caused deterioration in the clinical condition of 6 patients (4 with hypotention, one syncope, and one ventricular fibrillation). Management of patients for WPW complicating Af/AF without pre-excited QRS was the same as for the ordinary Af/AF. Over a period of 53 +/- 44 months of follow-up, 5 died (3 of sudden death, one of heart failure, and one of noncardiac cause) in the group with preexcited Af/AF, but all of the patients without preexcited QRS during Af/AF were alive. Conclusion, clinical severity, response to the treatment, and long-term prognosis of patients of WPW with preexcited Af/AF are different from those without.

Neurotrophin-4/5 maintains the cholinergic phenotype of axotomized septal neurons

We examined the effect of intraseptal or intracerebroventricular (i.c. v.) infusions of NT-4/5 or intraseptal infusions of NGF on the level of immunohistochemical staining of choline acetyltransferase (ChAT)and the low-affinity nerve growth factor receptor (LNGFR)in the rat medial septum following unilateral transection of the fimbria. The extent of cell loss in the septum ipsilateral to the lesion, determined by cell counts of ChAT-immunopositive neurons and expressed as a ratio comparing the lesioned to the intact sides, was 0.28 in animals that received an infusion of phosphate-buffered saline (PBS). The ratios were 0.97 and 1.07 in animals that received an infusion of NT-4/5 into the ipsilateral ventricle and septum respectively. Septal infusions of NGF produced a ratio of ChAT-immunopositive cells of 1.03. The ratios of LNGFR-immunopositive neurons increased from 0.50 in PBS-infused animals to 0.79 and 0.83 in animals infused with NT-4/5 via the i.c. v. infusion of NT-4/5 or septal infusion of NT-4/5 or NGF. As determined by immunohistochemical staining, NT-4/5 infused into the lateral ventricle was detected in the periventricular portions of the forebrain ipsilateral to the infusion, while NT-4/5 or NGF infused intraseptally was detected in much of the septum, bilaterally. Furthermore, exogenous NT-4/5 or NGF was detected in numerous neuronal perikarya in the medial septal and diagonal band nuclei. These data demonstrate that, as with NGF, i.c.v. as well as septal infusions of NT-4/5 can maintain the phenotype of basal forebrain cholinergic neurons following axotomy.

Brain-derived neurotrophic factor (BDNF) prevents the degeneration of medial septal cholinergic neurons following fimbria transection

Brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family, supports the survival of developing basal forebrain cholinergic neurons in vitro and is retrogradely transported by cholinergic neurons of the medial septum and diagonal band following intrahippocampal injections in vivo. To substantiate a potential role for BDNF in the maintenance of forebrain cholinergic neurons in the adult brain, we assessed the ability of BDNF to sustain the phenotype of medial septal cholinergic neurons following a unilateral transection of the fimbria. BDNF, NGF, or vehicle solutions were infused continuously in adult female rats either into the lateral ventricle (intracerebroventricularly) or directly into the septum for 2 weeks beginning at the time of the transection. In vehicle-infused animals, only 28% of the ChAT-immunoreactive neurons remained on the side ipsilateral to the lesion compared to the contralateral intact side. When infused intracerebroventricularly, both BDNF and NGF reduced the extent of the phenotypic loss, in that 44% and 68%, respectively, of the ChAT-immunopositive neurons remained on the lesioned side. Intraseptal infusion proved even more effective, in that following BDNF and NGF treatment 60% and 86%, respectively, of the normal complement of ChAT-immunopositive neurons were apparent on the side ipsilateral to the lesion. Similar results were obtained when an antibody to the low-affinity NGF receptor was used to identify the cholinergic neurons. To determine if the apparent greater efficacy of NGF compared to BDNF might be related to differences in delivery, we examined the patterns of distribution of radiolabeled BDNF and NGF injected into the lateral ventricle. 125I-BDNF showed only very little diffusion from the ventricles into the adjacent neural tissue and negligible retrograde labeling of the neurons within the basal forebrain. 125I-NGF, however, diffused readily into the brain, resulting in widespread retrograde labeling of basal forebrain neurons. A similarly limited distribution pattern was observed where BDNF was detected immunohistochemically in animals infused intracerebroventricularly (12 micrograms/d) for 2 weeks. In contrast, when delivered intraseptally, the same dose of BDNF exhibited a widespread diffusion within the surrounding neuropil and retrograde labeling of neurons in the medial septum and the vertical limb of the diagonal band. Thus, when delivered effectively, BDNF has a substantial capacity to rescue axotomized cholinergic neurons.

Medium-dependent dissociation of cytotoxic and GABA-releasing effects of N-methyl-D-aspartate (NMDA), alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) and kainate in rat cortical cultures

The excitotoxic cell death and the release of gamma-amino-butyric acid (GABA) evoked by excitatory amino acids (EAAs) were comparatively examined in rat cortical sister cultures grown in serum-free (N2) and serum-supplemented (SSM) media. Cell death was induced by 24 h exposure to 1 mM N-methyl-D-aspartate (NMDA), alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) or kainate. [3H]GABA release was evoked by 5 min exposure of preloaded cultures to 0.5 mM NMDA, AMPA or kainate. EAAs evoked remarkable GABA release in both N2 and SSM cultures, but caused toxic cell death in SSM cultures, only. Our findings indicate that functionally active EAA receptors do not necessarily mediate neurotoxicity and suggest that excitotoxicity can be prevented without blocking excitatory transmission.

[The clinical manifestation of arrhythmogenic right ventricular dysplasia]

Five patients, 4 male, 1 female with age ranging from 25 to 65 were included in the study. All the cases admitted into the hospital because of episodes of ventricular tachycardia (VT). Four associated with history of Adams-Stokes attacks. Their common manifestations are as followed: 1. Sustained LBBB VT associated with history of syncope and/or Adams-Stokes-Syndrome. 2. Inverted T waves in right precordial leads. 3. Positive ventricular late potential. 4. Relatively normal heart on physical examination and X-ray film. 5. Enlargement and dysfunction of right ventricle, 3 with a diverticulum-like bulging lesion at apex of right ventricle, proved by echocardiographic and nuclear angiocardiographic study. 6. Repeatedly induced VT during electrophysiological study. Our data suggest that arrhythmogenic right ventricular dysplasia (ARVD) should be suspected in patients with recurrent LBBB VT and relatively normal heart, especially, those with positive ventricular late potential. Right ventricle should be carefully investigated with echocardiography and nuclear angiocardiography to confirm the diagnosis. Four cases in the study were refractory to antiarrhythmic drug therapy and 2 of them were treated successfully with transcatheter electrical ablation, 1 with surgical intervention.

Prediction of terminal atrial myocardial repolarisation from incomplete phase 3 data

The duration of the monophasic action potential (MAP) carries prognostic antiarrhythmic information when the recording is done during sinus rhythm (SR) after DC conversion of atrial fibrillation (AF). This study analyses whether it is possible to predict MAP duration during sinus rhythm by analysing the atrial MAP during AF, even though complete myocardial repolarisation is never reached during this arrhythmia. We have therefore evaluated the estimated duration of the action potential (AP) and MAP by exponential extrapolation of phase 3 data. (1) AP studies were done on 11 human atrial myocardial specimens. Resting membrane potential (RMP) and AP duration were better identified when more data obtained during repolarisation were used for prediction. Thus the predicted RMP deviated on average by -0.4% of AF amplitude from the real RMP level when data to 90% repolarisation were used for extrapolation. AP duration at 90% repolarisation correlated well with the real AP duration (r = 0.88) at this level of data aquisition. (2) Continuous recording of atrial MAPs was done in 15 patients during AF and in 12 of these during SR after DC conversion. Resting myocardial repolarisation level during AF, RP(EST), and estimated MAP duration, MAPD(EST), could be calculated by exponential extrapolation in 12 patients. The actual repolarisation during fibrillation reached below 90% of the RP(EST) level in eight patients and below 70% in all 12. The MAP duration during SR could be predicted with increasing precision when data closer to the RP(EST) were used for calculation of MAPD(EST). Thus MAPD(EST) correlated well with SR MAP duration when data reaching at least 90% of RP were used (r = 0.85).(ABSTRACT TRUNCATED AT 250 WORDS)

Noninvasive support for and characterization of multiple intranodal pathways in patients with mitral valve disease and atrial fibrillation

Twenty-four-hour ambulatory ECG recordings were made in 22 patients with mitral valve disease and sustained atrial fibrillation. Computer analysis was used to stratify 64-beat periods according to the average ventricular rate levels. The distribution of pooled RR-intervals from heart-rate levels 50-60, 60-70 ... 160-170 were then presented as histograms, using a 20 ms width. This heart-rate stratified analysis revealed a bi- or trimodal RR-distribution in 16 of the 22 patients. This finding was interpreted as indicating the presence of two separate atrionodal pathways and in some cases nodal escape activity in addition. A limited heart-rate range may have obscured this phenomenon in 5 of the 6 cases without signs of bimodality. At high heart rates, AV-nodal conduction occurred via a 'fast pathway' whilst at successively lower heart rates, this conduction was blocked and a 'slower pathway' was used instead. In addition, at successively slower rates, the dominant cycle of conduction via either pathway tended to lengthen according to a linear relationship. The change of dominance from the fast to the slow pathway occurred between 90 and 120 beats per minute in almost all cases. The further electrophysiological characterization of patients with 2 pathways was done by calculation of differences and ratios between lengths of dominant cycles of different pathways at the rate of change of dominance. The findings may serve as reference data for further studies of AV-nodal conduction using the same method. Furthermore, the study strongly indicates that dual AV-nodal pathways are an ubiquitous phenomenon and supports the hypothesis that even in man, AV-nodal input follows two main routes: along the crista terminals between the coronary sinus and the tricuspid valve and from the interatrial septum.