mRNA nuclear retention reduces AMPAR expression and promotes autistic behavior in UBE3A-overexpressing mice

UBE3A is a common genetic factor in ASD etiology, and transgenic mice overexpressing UBE3A exhibit typical autistic-like behaviors. Because AMPA receptors (AMPARs) mediate most of the excitatory synaptic transmission in the brain, and synaptic dysregulation is considered one of the primary cellular mechanisms in ASD pathology, we investigate here the involvement of AMPARs in UBE3A-dependent ASD. We show that expression of the AMPAR GluA1 subunit is decreased in UBE3A-overexpressing mice, and that AMPAR-mediated neuronal activity is reduced. GluA1 mRNA is trapped in the nucleus of UBE3A-overexpressing neurons, suppressing GluA1 protein synthesis. Also, SARNP, an mRNA nuclear export protein, is downregulated in UBE3A-overexpressing neurons, causing GluA1 mRNA nuclear retention. Restoring SARNP levels not only rescues GluA1 mRNA localization and protein expression, but also normalizes neuronal activity and autistic behaviors in mice overexpressing UBE3A. These findings indicate that SARNP plays a crucial role in the cellular and behavioral phenotypes of UBE3A-induced ASD by regulating nuclear mRNA trafficking and protein translation of a key AMPAR subunit.

[Epidemiological characteristics of typhoid fever in Fujian Province, 2011-2022]

Objective: To analyze the incidence trend and epidemiological characteristics of typhoid fever in Fujian Province from 2011 to 2022, and understand the high-incidence population and hotspot areas, and provide evidences to develop more targeted prevention and control measures. Methods: The surveillance data of typhoid fever during 2011-2022 in Fujian Province were obtained from the National Disease Reporting Information System and analyzed with SAS 9.4. The spatial autocorrelation analysis of typhoid fever incidence at county/district levels was performed with ArcGlS 10.8. Results: A total of 5 126 cases of typhoid fever were reported in Fujian Province from 2011 to 2022, with an average annual incidence rate of 1.10/100 000. The average annual incidence rate was 0.96/100 000 from 2011 to 2015, 1.49/100 000 from 2016 to 2019, and 0.81/100 000 from 2020 to 2022. The disease occurred all the year round, with high epidemic season from May to September. A total of 23.59% (1 209/5 126) of the cases occurred at the age of 0-4, and 9.62% (493/5 126) at the age of 5-9. The male to female ratio of the cases was 0.97∶1 (2 524∶2 602) for the whole population, 1.19∶1 (925∶777) for people under 10 years old, 0.75∶1 (1 060∶1 404) for people between 10 and 54 years old, and 1.28∶1 (539∶421) for people over 55 years old. Cases in Ningde City accounted for 30.65% (1 571/5 126) of the total cases. Most hotspots were occurred in Ningde City. Recurrent and clustered cases were found in family members. Conclusions: Typhoid fever was prevalent at a low level in Fujian Province during 2011-2022, indicating that strengthening the prevention and control measures should target key areas and populations. The incidence of typhoid fever in Fujian Province showed spatial aggregation phenomenon, and most cases gathered in Ningde City. Intensive study for the influencing factors of spatial clustering should be conducted.

Ultrasound-Induced Membrane Hyperpolarization in Motor Axons and Muscle Fibers of the Crayfish Neuromuscular Junction

OBJECTIVE

Focused ultrasound (FUS) can modulate neuronal activity by depolarization or hyperpolarization. Although FUS-evoked depolarization has been studied extensively, the mechanisms underlying FUS-evoked hyperpolarization (FUSH) have received little attention. In the study described here, we developed a procedure using FUS to selectively hyperpolarize motor axons in crayfish. As a previous study had reported that these axons express mechano- and thermosensitive two-pore domain potassium (K2P) channels, we tested the hypothesis that K2P channels underlie FUSH.

METHODS

Intracellular recordings from a motor axon and a muscle fiber were obtained simultaneously from the crayfish opener neuromuscular preparation. FUSH was examined while K2P channel activities were modulated by varying temperature or by K2P channel blockers.

RESULTS

FUSH in the axons did not exhibit a coherent temperature dependence, consistent with predicted K2P channel behavior, although changes in the resting membrane potential of the same axons indicated well-behaved K2P channel temperature dependence. The same conclusion was supported by pharmacological data; namely, FUSH was not suppressed by K2P channel blockers. Comparison between the FUS-evoked responses recorded in motor axons and muscle fibers revealed that the latter exhibited very little FUSH, indicating that the FUSH was specific to the axons.

CONCLUSION

It is not likely that K2P channels are the underlying mechanism for FUSH in motor axons. Alternative mechanisms such as sonophore and axon-specific potassium channels were considered. Although the sonophore hypothesis could account for electrophysiological features of axonal recordings, it is not consistent with the lack of FUSH in muscle fibers. An axon-specific and mechanosensitive potassium channel is also a possible explanation.

Epidemiology of Severe Fever with Thrombocytopenia Syndrome in Dogs and Cats in Taiwan

Severe Fever with Thrombocytopenia Syndrome (SFTS), caused by the SFTS Virus (SFTSV), is a global health threat. SFTSV in Taiwan has only been reported in ruminants and wild animals. Thus, we aimed to investigate the infection statuses of dogs and cats, the animals with closer human interactions. Overall, the SFTSV RNA prevalence was 23% (170/735), with dogs showing a 25.9% (111/429) prevalence and cats at 19.3% (59/306) prevalence. Noticeably, the prevalence in stray animals (39.8% 77/193) was significantly higher than in domesticated ones (17.2%, 93/542). Among the four categories analyzed, the highest SFTSV prevalence was found in the stray dogs at 53.9% (120/193), significantly higher than the 24.2% prevalence noted in stray cats. In contrast, domesticated animals exhibited similar prevalence rates, with 17.1% for dogs and 17.2% for cats. It is noteworthy that in the domesticated animal groups, a significantly elevated prevalence (45%, 9/20) was observed among cats exhibiting thrombocytopenia compared to those platelet counts in the reference range (4.8%, 1/21). The high infection rate in stray animals, especially stray dogs, indicated that exposure to various outdoor environments influences the prevalence of infections. Given the higher human interaction with dogs and cats, there is a need for proactive measures to reduce the risk associated with the infection of SFTSV in both animals and humans.

Effects of Osmolarity on Ultrasound-Induced Membrane Depolarization in Isolated Crayfish Motor Axon

We have previously identified a novel non-selective membrane conductance (g_US) opened by focused ultrasound (FUS) in crayfish motor axons. In the work described here, we studied g_US properties further by comparing FUS-evoked depolarization (FUSD) in control and hypotonic saline with 75% of control osmolarity. The FUS was a train of 20 FUS bursts (2.1 MHz and 50 µs per burst) delivered at 1 kHz. The amplitude, onset latency, frequency of occurrence and duration of FUSD were compared in a 15-min time window before and after switching to hypotonic saline. Significant increases were observed for amplitude (p < 0.001) and frequency of occurrence (p < 0.01) while the onset latency exhibited a significant decrease (p < 0.001). FUSD duration did not significantly differ. These results support predictions based on our hypothesis that g_US is mediated by opening of nanopores in the lipid bilayer and that stretching of axonal membrane caused by swelling at low osmolarity should increase the probability of nanopore formation under FUS. The FUSD parameters, in addition, exhibited time-dependent trends when the window of observation was expanded to 45 min in each saline. The statistical significance of amplitude and duration differed between 15- and 45-min time windows, indicating the presence of adaptive responses of axonal membrane to osmotic manipulation.

Bidirectional modulation of evoked synaptic transmission by pulsed infrared light

Infrared (IR) neuromodulation (INM) has been demonstrated as a novel modulation modality of neuronal excitability. However, the effects of pulsed IR light on synaptic transmission have not been investigated systematically. In this report, the IR light (2 μm) is used to directly modulate evoked synaptic transmission at the crayfish opener neuromuscular junction. The extracellularly recorded terminal action potentials (tAPs) and evoked excitatory postsynaptic currents (EPSCs) modulated by localized IR light illumination (500 ms, 3–13 mW) aimed at the synapses are analyzed. The impact of a single IR light pulse on the presynaptic Ca²⁺ influx is monitored with Ca²⁺ indicators. The EPSC amplitude is enhanced, and its rising phase is accelerated under relatively low IR light power levels and localized temperature rises. Increasing the IR light power reversibly suppresses and eventually blocks the EPSCs. Meanwhile, the synaptic delay, tAP amplitude, and presynaptic Ca²⁺ influx decrease monotonously with higher IR light power. It is demonstrated for the first time that IR light illumination has bidirectional effects on evoked synaptic transmission. These results highlight the efficacy and flexibility of using pulsed IR light to directly control synaptic transmission and advance our understanding of INM of neural networks.

Functions of potassium channels blocked by low micromolar 4-aminopyridine in the crayfish nervous system

4-aminopyridine (4-AP) is a potassium channel blocker that has been used to treat patients with multiple sclerosis and Lambert-Eaton disease. The concentration of this drug in the blood of patients was estimated to be in low or submicromolar range. Animal studies have shown that 4-AP at such low concentration selectively blocks a subset of channels in Kv1 or Kv3 families. The crayfish opener neuromuscular junction and ventral superficial flexor (VSF) preparations were used to examine functions of K⁺ channels blocked by low concentrations of 4-AP. At opener motor axons, intracellular recordings show that 4-AP could increase action potential (AP) amplitude, duration and after-depolarization (ADP) at 10 μM. As 4-AP concentration was increased, in two-fold steps, AP amplitude did not increase further up to 5 mM. AP duration and ADP increased significantly mainly in two concentration ranges, 10-50 μM and 1-5 mM. The effects of 50 μM 4-AP on the VSF were less consistent than that observed at the opener motor axons. 4-AP did not change AP amplitude of motor axons recorded with an extracellular electrode and changes in AP repolarizing potential was observed in ∼25% of the axons. EPSP recorded simultaneously with AP showed an increase in amplitude with 4-AP treatment only in 30% of the axon-EPSP pairs. 4-AP also increased firing frequencies of ∼50% of axons. In four animals, 4-AP "awakened" the firing of APs from an axon that was silent before the drug. The mixture of positive and negative 4-AP effects summarized above was observed in the same VSF preparations in all cases (n = 8). We propose that there is a significant diversity in the density 4-AP sensitive potassium channels among motor axons of the VSF. Functional significance in the differences of 4-AP sensitivity of the two motor systems is discussed. This article is protected by copyright. All rights reserved.

[Analysis on repetitive reporting of hepatitis B in Fujian province, 2016-2020]

Objective: To analyze the repetitive reporting of hepatitis B in Fujian province during 2016-2020, and provide evidence for the improvement of hepatitis B surveillance. Methods: The reporting cards from the China Information System for Disease Control and Prevention were collected and divided into repetitive reporting cards and non-repetitive reporting cards from the report cards collected according to the valid ID number on the cards, and the proportion of repetitive report cards and related factors were analyzed by using software SAS 9.4. Results: A total of 314 551 hepatitis B reporting cards were submitted in Fujian from 2016 to 2020, in which 90.93% (286 020/314 551) were included in the analysis. The repetitive reporting cards accounted for 10.48% (29 982/286 020). The annual proportion of the repetitive reporting cards from 2016 to 2020 was between 2.98% and 3.71%, showing an overall increasing trend year by year (Z=2.26, P=0.024). The proportions of the repetitive reporting cards in 1-5 years were 3.17%, 5.40%, 7.74%, 9.27% and 10.48%, respectively, showing an increase trend with year (Z=128.16, P<0.001). The proportions of the repetitive reporting cards in 10 areas of Fujian ranged from 5.44% to 13.48% with significant difference (χ²=2 050.41, P<0.001) and increased with the increase of reported incidence of hepatitis B (Z=26.92, P<0.001). There were significant differences in relationships between repetitive reporting proportion and sex, age and type of the cases between the areas with high incidence and low incidence of hepatitis B. Conclusions: The reported incidence of hepatitis B was seriously affected by the repetitive reporting in Fujian from 2016 to 2020. A cross-year and cross-area surveillance mechanism for hepatitis B should be established and targeted measures should be taken to strengthen the control of the repetitive reporting and improve the surveillance for hepatitis B.

Single infrared light pulses induce excitatory and inhibitory neuromodulation

The excitatory and inhibitory effects of single and brief infrared (IR) light pulses (2 µm) with millisecond durations and various power levels are investigated with a custom-built fiber amplification system. Intracellular recordings from motor axons of the crayfish opener neuromuscular junction are performed ex vivo. Single IR light pulses induce a membrane depolarization during the light pulses, which is followed by a hyperpolarization that can last up to 100 ms. The depolarization amplitude is dependent on the optical pulse duration, total energy deposition and membrane potential, but is insensitive to tetrodotoxin. The hyperpolarization reverses its polarity near the potassium equilibrium potential and is barium-sensitive. The membrane depolarization activates an action potential (AP) when the axon is near firing threshold, while the hyperpolarization reversibly inhibits rhythmically firing APs. In summary, we demonstrate for the first time that single and brief IR light pulses can evoke initial depolarization followed by hyperpolarization on individual motor axons. The corresponding mechanisms and functional outcomes of the dual effects are investigated.

Analysis of persistent organochlorine pesticides in shellfish and their risk assessment from aquafarms in Taiwan

In Taiwan, freshwater clams (Corbicula fluminea) and hard clams (Meretrix lusoria) are the most frequently raised shellfish in land-based pond aquaculture, but research on the accumulation of organochlorine pesticides (OCPs) in these shellfish is limited. We detected the levels of 14 OCPs in 62 shellfish from Taiwanese aquafarms by performing gas chromatography-tandem mass spectrometry. OCP residues were detected in 4.84% of the samples including readings of 0.04 mg/kg chlordane (in a freshwater clam), 0.03 mg/g p,p'-DDE (in a freshwater clam), and 0.02 mg/g p,p'-DDE (in a hard clam). However, the associated estimated daily intake values were less than the acceptable daily intake levels of chlordane and p,p'-DDE Therefore, the consumption of these shellfish presents no immediate health risks. Our findings contribute to food safety and serve as a reference for OCP screenings for aquatic shellfish.

Imipramine Accelerates Nonalcoholic Fatty Liver Disease, Renal Impairment, Diabetic Retinopathy, Insulin Resistance, and Urinary Chromium Loss in Obese Mice

Imipramine is a tricyclic antidepressant that has been approved for treating depression and anxiety in patients and animals and that has relatively mild side effects. However, the mechanisms of imipramine-associated disruption to metabolism and negative hepatic, renal, and retinal effects are not well defined. In this study, we evaluated C57BL6/J mice subjected to a high-fat diet (HFD) to study imipramine’s influences on obesity, fatty liver scores, glucose homeostasis, hepatic damage, distribution of chromium, and retinal/renal impairments. Obese mice receiving imipramine treatment had higher body, epididymal fat pad, and liver weights; higher serum triglyceride, aspartate and alanine aminotransferase, creatinine, blood urea nitrogen, renal antioxidant enzyme, and hepatic triglyceride levels; higher daily food efficiency; and higher expression levels of a marker of fatty acid regulation in the liver compared with the controls also fed an HFD. Furthermore, the obese mice that received imipramine treatment exhibited insulin resistance, worse glucose intolerance, decreased glucose transporter 4 expression and Akt phosphorylation levels, and increased chromium loss through urine. In addition, the treatment group exhibited considerably greater liver damage and higher fatty liver scores, paralleling the increases in patatin-like phospholipid domain containing protein 3 and the mRNA levels of sterol regulatory element-binding protein 1 and fatty acid-binding protein 4. Retinal injury worsened in imipramine-treated mice; decreases in retinal cell layer organization and retinal thickness and increases in nuclear factor κB and inducible nitric oxide synthase levels were observed. We conclude that administration of imipramine may result in the exacerbation of nonalcoholic fatty liver disease, diabetes, diabetic retinopathy, and kidney injury.

Clozapine Worsens Glucose Intolerance, Nonalcoholic Fatty Liver Disease, Kidney Damage, and Retinal Injury and Increases Renal Reactive Oxygen Species Production and Chromium Loss in Obese Mice

Clozapine is widely employed in the treatment of schizophrenia. Compared with that of atypical first-generation antipsychotics, atypical second-generation antipsychotics such as clozapine have less severe side effects and may positively affect obesity and blood glucose level. However, no systematic study of clozapine’s adverse metabolic effects—such as changes in kidney and liver function, body weight, glucose and triglyceride levels, and retinopathy—was conducted. This research investigated how clozapine affects weight, the bodily distribution of chromium, liver damage, fatty liver scores, glucose homeostasis, renal impairment, and retinopathy in mice fed a high fat diet (HFD). We discovered that obese mice treated with clozapine gained more weight and had greater kidney, liver, and retroperitoneal and epididymal fat pad masses; higher daily food efficiency; higher serum or hepatic triglyceride, aspartate aminotransferase, alanine aminotransferase, blood urea nitrogen, and creatinine levels; and higher hepatic lipid regulation marker expression than did the HFD-fed control mice. Furthermore, the clozapine group mice exhibited insulin resistance, poorer insulin sensitivity, greater glucose intolerance, and less Akt phosphorylation; their GLUT4 expression was lower, they had renal damage, more reactive oxygen species, and IL-1 expression, and, finally, their levels of antioxidative enzymes (superoxide dismutase, glutathione peroxidase, and catalase) were lower. Moreover, clozapine reduced the thickness of retinal cell layers and increased iNOS and NF-κB expression; a net negative chromium balance occurred because more chromium was excreted through urine, and this influenced chromium mobilization, which did not help overcome the hyperglycemia. Our clozapine group had considerably higher fatty liver scores, which was supported by the findings of lowered adiponectin protein levels and increased FASN protein, PNPLA3 protein, FABP4 mRNA, and SREBP1 mRNA levels. We conclude that clozapine can worsen nonalcoholic fatty liver disease, diabetes, and kidney and retinal injury. Therefore, long-term administration of clozapine warrants higher attention.

The Ameliorative Effects of Fucoidan in Thioacetaide-Induced Liver Injury in Mice

Liver disorders have been recognized as one major health concern. Fucoidan, a sulfated polysaccharide extracted from the brown seaweed Fucus serratus, has previously been reported as an anti-inflammatory and antioxidant. However, the discovery and validation of its hepatoprotective properties and elucidation of its mechanisms of action are still unknown. The objective of the current study was to investigate the effect and possible modes of action of a treatment of fucoidan against thioacetamide (TAA)-induced liver injury in male C57BL/6 mice by serum biochemical and histological analyses. The mouse model for liver damage was developed by the administration of TAA thrice a week for six weeks. The mice with TAA-induced liver injury were orally administered fucoidan once a day for 42 days. The treated mice showed significantly higher body weights; food intakes; hepatic antioxidative enzymes (catalase, glutathione peroxidase (GPx), and superoxide dismutase (SOD)); and a lower serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and C-reactive protein (CRP) levels. Additionally, a reduced hepatic IL-6 level and a decreased expression of inflammatory-related genes, such as cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) mRNA was observed. These results demonstrated that fucoidan had a hepatoprotective effect on liver injury through the suppression of the inflammatory responses and acting as an antioxidant. In addition, here, we validated the use of fucoidan against liver disorders with supporting molecular data.

The Role of Ginkgo biloba in Human Diseases

Ginkgo biloba is a large, deciduous tree that matures to 100' tall and is considered to be a living fossil. It is the only surviving member of a group of ancient plants believed to have inhabited the earth up to 150 million years ago. In traditional Chinese medicine, G. biloba preparations have been used for centuries for the management of disorders such as anxiety, allergy, dementia, eye problems, peripheral artery disease, tinnitus, liver fibrosis, hepatocellular carcinoma, and cardiovascular health. Centuries of experience has also shown it to be safe and effective to be used as herbal medicine. This short review, dedicated to the memory of Prof. Keith A. Wesnes, summarizes in vitro and in vivo human studies documenting therapeutic effects of G. biloba preparations for human health.

Infrared inhibition impacts on locally initiated and propagating action potentials and the downstream synaptic transmission

Significance: Systematic studies of the physiological outputs induced by infrared (IR)-mediated inhibition of motor nerves can provide guidance for therapeutic applications and offer critical insights into IR light modulation of complex neural networks. Aim: We explore the IR-mediated inhibition of action potentials (APs) that either propagate along single axons or are initiated locally and their downstream synaptic transmission responses. Approach: APs were evoked locally by two-electrode current clamp or at a distance for propagating APs. The neuromuscular transmission was recorded with intracellular electrodes in muscle cells or macro-patch pipettes on terminal bouton clusters. Results: IR light pulses completely and reversibly terminate the locally initiated APs firing at low frequencies, which leads to blocking of the synaptic transmission. However, IR light pulses only suppress but do not block the amplitude and duration of propagating APs nor locally initiated APs firing at high frequencies. Such suppressed APs do not influence the postsynaptic responses at a distance. While the suppression of AP amplitude and duration is similar for propagating and locally evoked APs, only the former exhibits a 7% to 21% increase in the maximum time derivative of the AP rising phase. Conclusions: The suppressed APs of motor axons can resume their waveforms after passing the localized IR light illumination site, leaving the muscular and synaptic responses unchanged. IR-mediated modulation on propagating and locally evoked APs should be considered as two separate models for axonal and somatic modulations.

Examining the association between oral health status and dementia: A nationwide nested case-controlled study

Alzheimer’s disease as a consequence of chronic brain inflammation mediated by infectious microbes including the oral microbiome continues to attract support. Taiwan’s National Insurance database was used to evaluate associations between dental health and Alzheimer’s disease; 209,112 new cases of Alzheimer’s disease were matched 1:4 with 836,448 dementia-free controls to test the hypothesis that better dental health would be associated with less occurrence of dementia. Ten year dental records and conditional logistic regression models were used to estimate the odds ratios associated with Alzheimer’s disease. Subgroup analyses compared vascular Alzheimer’s disease and sporadic Alzheimer’s disease. As the population aged, Alzheimer’s disease diagnoses were more frequent with a 10 fold upward inflection after 60. Nearly 56% of sporadic Alzheimer’s disease patients were women but less than 50% had vascular Alzheimer’s disease. Comorbidities were 10–20% higher in the Alzheimer’s disease patients than in controls, but stroke, chronic infection, and pneumonia were 40–45% more common in the vascular Alzheimer’s disease patients. Heart disease, hypertension, diabetes, stroke, peripheral artery disease, pneumonia, and herpetic disease (HSV) were all associated with higher odds of Alzheimer’s disease. HSV was not a factor in the vascular Alzheimer’s disease. Routine dental procedures tended to lower odds ratios. Root canals and extractions that restore oral homeostasis were associated with lower odds of dementia. However, when extractions exceeded four, the odds of Alzheimer’s disease rose. The fact that Alzheimer’s disease was not associated with periodontal procedures per se but with more frequent periodontal emergencies suggested again a chronic issue. Dental health costs suggest that good dental care was associated with lower odds of Alzheimer’s disease except for radiographic costs which were consistently associated with higher odds, independent of oral health. Common comorbid conditions were associated with higher odds of Alzheimer’s disease and oral health care was associated with lower odds, providing support for the hypothesis that the oral microbiome is a factor in the development of Alzheimer’s disease.

Impact statement

This study clearly demonstrates the power and value of a nationally applied digital medical record. Longitudinal studies of gradually developing pathologies like dementia have often been limited by sample size and narrow and incomplete medical histories. The Taiwan National Insurance database provides an unparalleled opportunity for detailed analyses of associations between current medical conditions and a spectrum of prior medical and dental events. The temporal impact of the database will only become more important as the past historical record progressively expands going forward. The inclusion of dental records in assessing the relationship with subsequent dementia is very important because this information is often unavailable or dependent on subject recall. This study clearly establishes associations between a variety of suspected cardiovascular and metabolic factors and the odds of dementia. A critical outcome should include the design of targeted interventions and the subsequent assessment of their efficacy.

P38 Developing a model for predicting in-hospital death in patients with the use of extracorporeal membrane oxygenation

Funding Acknowledgements

Minister of Science and Technology

Background

The objective of this study was to develop a predicting model for estimating the odds of in-hospital death in the patients who receive extracorporeal membrane oxygenation (ECMO).

Methods

Adult patients who received ECMO for a variety of etiologies in our National University Hospital from 2005 and 2016 were included. The demographic, anthropometric, hemodynamic, and laboratory data when ECMO was instituted were recorded for each individual. A logistic regression model was applied to find the risk variables that were independently associated with in-hospital mortality. The predicted probability derived from the model was used to plot a receiver-operating-characteristic (ROC) curve, and area under curve (AUC) was found to represent the differentiating capacity of this approach.

Results

A total of 919 patients (659 men and 260 women) were included in the analysis. The mean age was 53.7[SD 15.9] years. The analysis showed that age (odds ratio [OR]: 1.018, 95% confidence interval [CI]: 1.008-1.028 per year), blood urea nitrogen (1.008 [1.001-1.014] per mg/dL), use of inotropic agent in terms of inotropic equivalent (1.007 [1.002-1.013]), the presence of cardiogenic shock (1.910 [1.097-3.327]), and the need of hemodialysis (2.262 [1.304-3.926]) were positively associated with mortality. In addition, body surface area (OR: 0.414 [0.204-0.840] per square meter), systolic blood pressure (0.995 [0.990-0.999] per mmHg), Glasgow Coma Scale (0.928 [0.899-0.957] per unit), pH value (0.395 [0.158-0.988] for each unit), and urine output (OR: 0.974 [0.964-0.985] per dL) were negatively associated with the probability of in-hospital death. The AUC in ROC analysis was 0.754 (95% CI: 0.722-0.787).

Conclusion

The predicting model that used a simple set of physiological parameters could substantially discriminate whether the patients receiving ECMO could survive the in-hospital course. Further studies are needed to examine why false positive and false negative predictions took place.

Abstract P38 Figure.

Infrared inhibition and waveform modulation of action potentials in the crayfish motor axon

The infrared (IR) inhibition of axonal activities in the crayfish neuromuscular preparation is studied using 2 µm IR light pulses with varying durations. The intracellular neuronal activities are monitored with two-electrode current clamp, while the IR-induced temperature changes are measured by the open patch technique simultaneously. It is demonstrated that the IR pulses can reversibly shape or block locally initiated action potentials. Suppression of the AP amplitude and duration and decrease in axonal excitability by IR pulses are quantitatively analyzed. While the AP amplitude and duration decrease similarly during IR illumination, it is discovered that the recovery of the AP duration after the IR pulses is slower than that of the AP amplitude. An IR-induced decrease in the input resistance (8.8%) is detected and discussed together with the temperature dependent changes in channel kinetics as contributing factors for the inhibition reported here.

NS2B/NS3 mutations enhance the infectivity of genotype I Japanese encephalitis virus in amplifying hosts

Genotype I (GI) virus has replaced genotype III (GIII) virus as the dominant Japanese encephalitis virus (JEV) in the epidemic area of Asia. The mechanism underlying the genotype replacement remains unclear. Therefore, we focused our current study on investigating the roles of mosquito vector and amplifying host(s) in JEV genotype replacement by comparing the replication ability of GI and GIII viruses. GI and GIII viruses had similar infection rates and replicated to similar viral titers after blood meal feedings in Culex tritaeniorhynchus. However, GI virus yielded a higher viral titer in amplifying host-derived cells, especially at an elevated temperature, and produced an earlier and higher viremia in experimentally inoculated pigs, ducklings, and young chickens. Subsequently we identified the amplification advantage of viral genetic determinants from GI viruses by utilizing chimeric and recombinant JEVs (rJEVs). Compared to the recombinant GIII virus (rGIII virus), we observed that both the recombinant GI virus and the chimeric rJEVs encoding GI virus-derived NS1-3 genes supported higher replication ability in amplifying hosts. The replication advantage of the chimeric rJEVs was lost after introduction of a single substitution from a GIII viral mutation (NS2B-L99V, NS3-S78A, or NS3-D177E). In addition, the gain-of-function assay further elucidated that rGIII virus encoding GI virus NS2B-V99L/NS3-A78S/E177E substitutions re-gained the enhanced replication ability. Thus, we conclude that the replication advantage of GI virus in pigs and poultry is the result of three critical NS2B/NS3 substitutions. This may lead to more efficient transmission of GI virus than GIII virus in the amplifying host-mosquito cycle.

Flaviviral vertebrate amplifying host(s), invertebrate vector(s), genetics, and environmental factors shape the viral geographical distribution and epidemic disease pattern. Newly emerging dengue virus genotypes, West Nile virus clades, or Zika virus strains exhibited an enhancement in mosquito vector competence. However, hosts and viral determinants responsible for the occurrence of JEV genotype replacement remains unclear. Here, we demonstrated that emerging GI viruses with enhanced transmission potential in amplifying hosts such as pigs and avian species was encoded by three critical GI-specific mutations in NS2B/NS3 proteins. This discovery provides insight into the viral genetic mechanism underlying the GI virus advantage and adaptation in the pig/avian species-mosquito cycle. Our results also emphasize the importance of monitoring viral evolution in amplifying vertebrate hosts to clarify the role of avian species in local transmission of GI virus in JE endemic and epidemic countries.

[Analysis on association between incidence of hand foot and mouth disease and meteorological factors in Xiamen, 2013-2017]

Objective: To study the influence of meteorological factors on the incidence of hand foot and mouth disease (HFMD) in Xiamen, Fujian province, and provide scientific evidence for the early warning, prediction, prevention and control of HFMD. Methods: Correlation analysis and distribution lag nonlinear models (DLNM) analysis of meteorological factors such as daily average pressure, daily average relative humidity, daily average temperature and sunshine hours and the incidence of HFMD in Xiamen during 2013 to 2017 were conducted by using R3.4.3 software. Results: A total of 36 464 cases of HFMD were reported in Xiamen during 2013-2017, and the incidence showed an upward trend (F=40.359, P=0.008). The daily average relative humidity, daily average temperature and sunshine hours were positively correlated with the incidence of HFMD (r>0), and the daily average site pressure was negatively correlated with the incidence of HFMD (r<0). In the case of a lag of 0-5 days, when the daily average pressure of the station was higher than 1 005 hPa, the risk of HFMD gradually increased with the increase of air pressure, and the risk of disease decreased with the increase of lag days. The risk was highest when air pressure was 1 017 hPa and at the lag of 0 day (RR=1.14, 95%CI: 0.67-1.94). When the relative humidity was higher than 95%, the risk of HFMD gradually increased with the increase of relative humidity, and the lag time ranged from 0 day to 10 days, which was most obvious on the 4(th) and 5(th) days. The risk was highest when relative humidity was 100% and at the lag of 5 days (RR=1.32, 95%CI: 1.02-1.71). When the air temperature was >28 ℃ and <8 ℃, the risk of HFMD existed, but the lag time was inconsistent. The relative risk was highest during 15-20 days at low air temperature, and the lag time at high air temperature was mainly during 5-15 days. The risk was highest when air temperature was 28 ℃ and at the lag of 4 days (RR=1.10, 95%CI: 0.94-1.29). The sunshine time was >12 h and lag of 0-3 days was a risk factor for the incidence of HFMD. The risk was highest when sunshine time was 13 h and the lag of 0 day (RR=1.20, 95%CI: 1.05-1.36). Conclusion: Meteorological factors such as daily average pressure, daily average relative humidity, daily average temperature and sunshine hours were associated with the incidence of HFMD with certain lag in Xiamen. So, it is suggested to use these data in the early warning system of HFMD.

Focused ultrasound transiently increases membrane conductance in isolated crayfish axon

We report a novel phenomenon produced by focused ultrasound (US) that may be important for understanding its effects on cell membranes. When a US burst (2.1 MHz, 1-mm focal diameter, 0.1-1 MPa) was focused on a motor axon of the crayfish neuromuscular junction, it consistently produced a fast hyperpolarization, which was followed or superseded by subthreshold depolarizations or action potentials in a stochastic manner. The depolarization persisted in the presence of voltage-gated channel blockers [1 µM TTX ( I_Na), 50 µM ZD7288 ( I_h), and 200 µM 4-aminopyridine ( I_K)] and typically started shortly after the onset of a 5-ms US burst, with a mean latency of 3.35 ± 0.53 ms (SE). The duration and amplitude of depolarizations averaged 2.13 ± 0.87 s and 10.1 ± 2.09 mV, with a maximum of 200 s and 60 mV, respectively. The US-induced depolarization was always associated with a decrease in membrane resistance. By measuring membrane potential and resistance during the US-induced depolarization, the reversal potential of US-induced conductance ( g_us) was estimated to be -8.4 ± 2.3 mV, suggesting a nonselective conductance. The increase in g_us was 10-100 times larger than the leak conductance; thus it could significantly influence neuronal activity. This change in conductance may be due to stimulation of mechanoreceptors. Alternatively, US may perturb the lateral motion of phospholipids and produce nanopores, which then increase g_us. These results may be important for understanding mechanisms underlying US-mediated modulation of neuronal activity and brain function. NEW & NOTEWORTHY We report a specific increase in membrane conductance produced by ultrasound (US) on neuronal membrane. When a 5-ms US tone burst was focused on a crayfish motor axon, it stochastically triggered either depolarization or a spike train. The depolarization was up to 60 mV in amplitude and 200 s in duration and therefore could significantly influence neuronal activity. Depolarization was still evoked by US burst in the presence of Na⁺ and Ca²⁺ channel blockers and had a reversal potential of -8.4 ± 2.3 mV, suggesting a nonselective permeability. US can be applied noninvasively in the form of a focused beam to deep brain areas through the skull and has been shown to modulate brain activity. Understanding the depolarization reported here should be helpful for improving the use of US for noninvasive modulation and stimulation in brain-related disease.

Virulence of Japanese Encephalitis Virus Genotypes I and III, Taiwan

The virulence of genotype I (GI) Japanese encephalitis virus (JEV) is under debate. We investigated differences in the virulence of GI and GIII JEV by calculating asymptomatic ratios based on serologic studies during GI- and GIII-JEV endemic periods. The results suggested equal virulence of GI and GIII JEV among humans.

Genotype I of Japanese Encephalitis Virus Virus-like Particles Elicit Sterilizing Immunity against Genotype I and III Viral Challenge in Swine

Swine are a critical amplifying host involved in human Japanese encephalitis (JE) outbreaks. Cross-genotypic immunogenicity and sterile protection are important for the current genotype III (GIII) virus-derived vaccines in swine, especially now that emerging genotype I (GI) JE virus (JEV) has replaced GIII virus as the dominant strain. Herein, we aimed to develop a system to generate GI JEV virus-like particles (VLPs) and evaluate the immunogenicity and protection of the GI vaccine candidate in mice and specific pathogen-free swine. A CHO-heparan sulfate-deficient (CHO-HS(-)) cell clone, named 51-10 clone, stably expressing GI-JEV VLP was selected and continually secreted GI VLPs without signs of cell fusion. 51-10 VLPs formed a homogeneously empty-particle morphology and exhibited similar antigenic activity as GI virus. GI VLP-immunized mice showed balanced cross-neutralizing antibody titers against GI to GIV viruses (50% focus-reduction micro-neutralization assay titers 71 to 240) as well as potent protection against GI or GIII virus infection. GI VLP-immunized swine challenged with GI or GIII viruses showed no fever, viremia, or viral RNA in tonsils, lymph nodes, and brains as compared with phosphate buffered saline-immunized swine. We thus conclude GI VLPs can provide sterile protection against GI and GIII viruses in swine.

Magnetic correlations in the intermetallic antiferromagnet Nd3Co4Sn13

Specific heat, magnetic susceptibility, and neutron scattering have been used to investigate the nature of the spin system in the antiferromagnet Nd₃Co₄Sn₁₃. At room temperature Nd₃Co₄Sn₁₃ has a cubic, Pm-3n structure similar to Yb₃Rh₄Sn₁₃. Antiferromagnetic interactions between, Nd³⁺ ions dominate the magnetic character of this sample and at 2.4 K the Nd spins enter a long range order state with a magnetic propagation vector q  =  (0 0 0) with an ordered moment of 1.78(2) µ_B at 1.5 K. The magnetic Bragg intensity grows very slowly below 1 K, reaching ~2.4 µ_B at 350 mK. The average magnetic Nd³⁺ configuration corresponds to the 3D irreducible representation Γ₇. This magnetic structure can be viewed as three sublattices of antiferromagnetic spin chains coupled with each other in the 120°-configuration. A well-defined magnetic excitation was measured around the 1 1 1 zone centre and the resulting dispersion curve is appropriate for an antiferromagnet with a gap of 0.20(1) meV.

Effects of Deltamethrin on crayfish motor axon activity and neuromuscular transmission

Deltamethrin (DM) is a widely used pesticide known to target sodium channels. Although this compound has been studied extensively at molecular and behavioral levels, the detailed action of DM on cellular and synaptic function is less well documented. In this report, we show that DM at nanomolar concentrations can silence tonic motor output of the crayfish ventral superficial flexor (VSF) within ∼10 min. Action potential (AP) amplitude was consistently reduced before silencing occurred, whereas AP duration and AP firing frequency did not change. In some synapses EPSP amplitude and synaptic delay were modified by DM, but the direction of change was not consistent. In order to better understand these diverse effects, intracellular recordings from motor axons of the crayfish opener were used for a detailed analysis. DM caused an initial, slow depolarization of resting membrane potential (Vm), which was accompanied by reduced AP amplitude but not AP duration. Resting Vm then underwent a step depolarization of ∼20 mV, which we propose corresponds to the onset of the depolarization block. In addition, DM shifted the AP initiation site in some opener axons during prolonged firing. This shift occurred concomitantly with a reduction in synaptic delay. A similar reduction in synaptic delay was also detected at some VSF axons, and can be attributed to the same mechanism. Results reported here suggest that DM at low concentrations result in: (i) depolarization block of motor axons before changes in network output can be detected, (ii) variable effects on synaptic transmission, with this variability presumably due to the diverse morphology and excitability of motor axons.

Na+ current in presynaptic terminals of the crayfish opener cannot initiate action potentials

Action potential (AP) propagation in presynaptic axons of the crayfish opener neuromuscular junction (NMJ) was investigated by simultaneously recording from a terminal varicosity and a proximal branch. Although orthodromically conducting APs could be recorded in terminals with amplitudes up to 70 mV, depolarizing steps in terminals to -20 mV or higher failed to fire APs. Patch-clamp recordings did detect Na(+) current (INa) in most terminals. The INa exhibited a high threshold and fast activation rate. Local perfusion of Na(+)-free saline showed that terminal INa contributed to AP waveform by slightly accelerating the rising phase and increasing the peak amplitude. These findings suggest that terminal INa functions to "touch up" but not to generate APs.

Factors associated with adherence to low-tidal volume strategy for acute lung injury and acute respiratory distress syndrome and their impacts on outcomes: an observational study and propensity analysis

BACKGROUND

The purpose of this study was to investigate the factors affecting adherence to the low-tidal volume (LTV) strategy in acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) and their impacts on outcomes.

METHODS

This prospective observational study included 111 patients with ALI/ARDS admitted to six intensive care units between March 2010 and February 2011. The patients were divided into the LTV group, which received a TV ≤7.5 mL/kg predicted body weight (PBW), and the non-LTV group, which received a TV >7.5 mL/kg PBW. We studied the association of selected clinical factors and adherence to the LTV strategy, and evaluated their impacts on 28-day mortality and 1-year mortality by the propensity-match process.

RESULTS

Adherence to the LTV strategy was only 44%, which was related to lung injury severity (odds ratio [OR]: 3.15, P=0.038), muscle relaxant use (OR: 3.28, P=0.031), and depth of sedation (OR: 0.65, P=0.008). Propensity score-based analysis showed that the LTV group had modestly better 28-day survival (P=0.081) and 1-year survival (P=0.067) than the non-LTV group. Moreover, muscle relaxant use was strongly associated with reducing the risk of death at both 28 days (hazard ratio [HR]: 0.122, 95% confidence interval [CI]: 0.027-0.542, P=0.006) and 1 year ([HR]: 0.111, 95% [CI]: 0.030-0.408, P=0.001).

CONCLUSION

Adherence to the LTV strategy was strongly associated with the lung injury score, muscle relaxant use, and depth of sedation. Propensity score-based analysis showed that the use of LTV ventilation and muscle relaxants reduced 28-day and 1-year mortality in ALI/ARDS patients.

Evaluating the potential risks of bubble studies during echocardiography

Objective:

Cardiac shunts are often identified using bubble studies in echocardiography, with agitated saline. Previous studies have recommended various safe amounts of agitated saline. This poses a potential risk for air microembolism. The purpose of this study was to quantify the bubbles created by various quantities of agitated saline.

Methods:

A closed circuit was constructed with a HeartMate pneumatic ventricular assist pump and a cardiotomy reservoir to remove air during recirculation. One empty 10 mL syringe and one 10 mL syringe containing 1 mL of air and 9 mL of saline were attached to a three-way stopcock. The air/saline bolus was then agitated between the two syringes five times to create bubbles and injected into the tubing proximal to the HeartMate. An EDAC bubble detector sensor was attached prior to the saline injection site and distal to the HeartMate I to measure the size and volume of the bubbles. This technique was repeated using 0.5 mL of air and 9.5 mL of saline bolus and 2 mL of air and 8 mL of saline bolus. Each bolus was tested 20 times.

Results:

This study identifies the potential risks of air administration and proposes a safer air volume to agitate for the administration of a bubble study.

Conclusions:

Further studies should be conducted to create either a guideline or a standard for agitated saline administration by the Intersocietal Commission for the Accreditation of Echocardiography Laboratories (ICAEL) in order to minimize the risk of air microembolism

Application of a spike sorting procedure to analyze recordings in the crayfish ventral superficial flexor preparation: A high resolution approach to the study of neuromodulators on axons and synapses

The crayfish ventral superficial flexor (VSF) is innervated by the ventral branch of the third nerve. This nerve and muscle system is tonic, and is responsible for posture control of the animal. The easy accessibility of the third nerve and its muscle fibers, along with its display of tonic activity in vitro, make this preparation ideal for observing axonal action potentials and synaptic responses. As a result, this preparation has often been adopted for undergraduate electrophysiology laboratories. This report describes application of a spike sorting procedure to simultaneously recorded traces from the third nerve and associated muscle fiber. This procedure allows for isolation of action potentials arising from each of the six axons in the third nerve. Separation of action potentials and their corresponding synaptic responses from large data sets, with sample sizes in the thousands, enables us to perform averaging and to analyze waveforms of action potentials and synaptic responses with a high resolution. With this high resolution approach, we document variations in the shape of action potentials in the third nerve and in synaptic potential in muscle fibers. The approach described here can be used for detailed study of the effects mediated by neuromodulators and drugs. An example of such an application is illustrated using 50 μM GABA. Several possible student projects using this approach are outlined and discussed.

Neuroprotective effect of agmatine in rats with transient cerebral ischemia using MR imaging and histopathologic evaluation

PURPOSE

This study aimed to further investigate the effects of agmatine on brain edema in the rats with middle cerebral artery occlusion (MCAO) injury using magnetic resonance imaging (MRI) monitoring and biochemical and histopathologic evaluation.

MATERIALS AND METHODS

Following surgical induction of MCAO for 90min, agmatine was injected 5min after beginning of reperfusion and again once daily for the next 3 post-operative days. The events during ischemia and reperfusion were investigated by T2-weighted images (T2WI), serial diffusion-weighted images (DWI), calculated apparent diffusion coefficient (ADC) maps and contrast-enhanced T1-weighted images (CE-T1WI) during 3h-72h in a 1.5T Siemens MAGNETON Avanto Scanner. Lesion volumes were analyzed in a blinded and randomized manner. Triphenyltetrazolium chloride (TTC), Nissl, and Evans Blue stainings were performed at the corresponding sections.

RESULTS

Increased lesion volumes derived from T2WI, DWI, ADC, CE-T1WI, and TTC all were noted at 3h and peaked at 24h-48h after MCAO injury. TTC-derived infarct volumes were not significantly different from the T2WI, DWI-, and CE-T1WI-derived lesion volumes at the last imaging time (72h) point except for significantly smaller ADC lesions in the MCAO model (P<0.05). Volumetric calculation based on TTC-derived infarct also correlated significantly stronger to volumetric calculation based on last imaging time point derived on T2WI, DWI or CE-T1WI than ADC (P<0.05). At the last imaging time point, a significant increase in Evans Blue extravasation and a significant decrease in Nissl-positive cells numbers were noted in the vehicle-treated MCAO injured animals. The lesion volumes derived from T2WI, DWI, CE-T1WI, and Evans blue extravasation as well as the reduced numbers of Nissl-positive cells were all significantly attenuated in the agmatine-treated rats compared with the control ischemia rats (P<0.05).

CONCLUSION

Our results suggest that agmatine has neuroprotective effects against brain edema on a reperfusion model after transient cerebral ischemia.

First detection of the Africa/Caribbean/Latin American subtype of Culex flavivirus in Asian country, Taiwan

Culex flavivirus (CxFV), a member of the genus flavivirus, is a novel insect-specific flaviviruses that can be divided into two subtypes, the cytopathic Asia/U.S. and the noncytopathic Africa/Caribbean/Latin American subtypes. The CxFV circulates in several Asian countries, and here we conducted the first study investigating CxFV in Taiwan. A total of 14,016 mosquitoes were collected between 2010 and 2012 and 3.4% (6/179) of the pools were CxFV-positive. The phylogenetic analyses indicate that the Taiwan isolates are closely related to the Africa/Caribbean/Latin American subtype, but form an independent cluster. In the cytology experiments, the CxFV Taiwan isolate infected only mosquito cells and caused cell-cell fusion that might be associated with a unique glycine residue at position 117 within the envelope protein, which is shared with the cytopathic effect-causing Asia/US subtype. This study marks the first time the Africa/Caribbean/Latin American subtype of CxFV has been identified in an Asian country and grouped into a novel cluster.

Detection and differentiation of genotype I and III Japanese encephalitis virus in mosquitoes by multiplex reverse transcriptase-polymerase chain reaction

Japanese encephalitis (JE) is a disease that threatens both human and animal populations in Asian countries, and the causative agent of JE, Japanese encephalitis virus (JEV), has recently changed from genotype III (GIII) to genotype I (GI). However, a test for the rapid differentiation of GI and GIII JEV is still unavailable, especially one that can be used for mosquito-based surveillance. We have designed GI- and GIII-specific primer sets for the rapid detection and differentiation of GI and GIII JEV by multiplex reverse transcriptase-polymerase chain reaction (multiplex RT-PCR). The GI-specific and GIII-specific primer sets were able to specifically amplify the target gene from GI and GIII JEV, respectively. The limitations of detection were 0.00225 and 0.225 pfu for the GI-specific and GIII-specific primers, respectively. Using a mixture of GI-specific and GIII-specific primers, the multiplex RT-PCR was able to specifically detect and differentiate GI and GIII JEV. The multiplex RT-PCR was able to successfully differentiate GI and GIII virus in JEV-infected mosquitoes. Thus, a sensitive and specific multiplex RT-PCR system for the rapid detection and differentiation of GI and GIII JEV has been developed, and this test is likely to be valuable when carrying out mosquito-based JEV surveillance.

Spatial gradient in TTX sensitivity of axons at the crayfish opener neuromuscular junction

At the crayfish opener neuromuscular junction, axons branch repeatedly before synapsing onto muscle fibers as varicosities. Excitability of these axons was examined with two-electrode current clamp before and after partial block of Na(+) channels with 1 nM tetrodotoxin. 4-Aminopyridine (200 μM) was added to homogenize nonuniformity in K(+) channel density. The impact of tetrodotoxin was evaluated in terms of action potential (AP) amplitude, rate of rise, and threshold. All three parameters were more severely affected at the secondary than the primary branching point (BP). Both BPs fired continuously during 1-s current steps before tetrodotoxin. After tetrodotoxin, the secondary BP fired only in brief bursts, whereas the primary BP still fired continuously. Despite this diminished excitability at the secondary BP, no failure in orthodromic AP conduction was observed. AP waveform at terminals (AP(f)) was examined with voltage indicators. For orthodromic APs, reduction in AP amplitude and prolongation of AP rise time in tetrodotoxin were more pronounced in terminals than at the secondary BP. For APs initiated at the secondary BP, AP(f) sometimes failed to show a spikelike waveform in tetrodotoxin. This degraded AP(f) was not due to averaging variable AP invasion into terminals, because the variance of AP(f) traces did not increase in tetrodotoxin. Tetrodotoxin applied in the absence of 4-aminopyridine showed an impact on the distal axon similar but less distinct than that recorded with 4-aminopyridine. In conclusion, the distal axon is more sensitive to tetrodotoxin than the proximal axon, such that AP waveform degrades as it propagates toward terminals in tetrodotoxin.

Partially neutralizing potency against emerging genotype I virus among children received formalin-inactivated Japanese encephalitis virus vaccine

Background

Genotype I (GI) Japanese encephalitis virus (JEV) that replaced GIII virus has become the dominant circulating virus in Asia. Currently, all registered live and inactivated JEV vaccines are derived from genotype III viruses. In Taiwan, the compulsory JEV vaccination policy recommends that children receives four doses of formalin-inactivated Nakayama (GIII) JEV vaccine.

Methodology/Principal Findings

To evaluate the influence of genotype replacement on the post-vaccination viral neutralizing ability by GIII and GI viruses, the small panel of vaccinated-children serum specimens was assembled, and the reciprocal 50% plaque-reduction neutralizing antibody titers (PRNT₅₀) were measured against Nakayama vaccine strain, CJN GIII human brain isolate and TC2009-1 GI mosquito isolate. The seropositivity rate (PRNT₅₀≥1∶10) and geometric mean titers (GMT) against the TC2009-1 virus were the lowest among the three viruses. The protective threshold against the CJN and TC2009-1 viruses could only be achieved when the GMT against Nakayama virus was ≥1∶20 or ≥1∶80, respectively. Using undiluted vaccinees' sera, the enhancement of JEV infection in K562 cells was observed in some low or non-neutralizing serum specimens.

Conclusions/Significance

Our preliminary study has shown that neutralizing antibodies, elicited by the mouse brain-derived and formalin-inactivated JEV Nakayama vaccine among a limited number of vaccinees, have reduced neutralizing capacity against circulating GI virus, but more detailed studies are needed to address the potential impact on the future vaccine policy.

Genotype I (GI) Japanese encephalitis virus (JEV) that replaced GIII virus has become the dominant circulating virus in Asia; however, all available JEV vaccines are derived from genotype III viruses, and no study has been conducted on the cross-neutralization and protection elicited by GIII JEV vaccines against GI viruses using vaccinated children’s serum specimens collected from the general population. Genotype I virus was first detected in Taiwan in 2008, and became the dominant circulating JEV, and was island-wide within a year. In the present study, the small panel of GIII virus vaccinated-children serum specimens were not only showed lower strain-specific neutralization against GI virus as compared to the GIII vaccine and human isolates but also observed the enhancement of GI virus infection in K562 cells in some low or non-neutralizing serum specimens. These preliminary results indicated the reduced neutralization potency due to genotype replacement should be closely monitored in the JE epidemic/endemic regions in the future.

Spatial variation in membrane excitability modulated by 4-AP-sensitive K+ channels in the axons of the crayfish neuromuscular junction

Current-clamp recordings were made from the primary (1°) and secondary (2°) branching points (BPs) of axons at the crayfish neuromuscular junction. Action potential (AP) firing initiated by current injected at the 2° BP showed strong adaptation or high-frequency firing at threshold current, whereas AP firing frequency at the 1° BP exhibited a gradual rise with increasing current amplitude. The voltage threshold for AP (V(TH)) was higher at the 2° BP than the 1° BP. 4-Aminopyridine (4-AP) at 200 μM increased AP amplitude and duration at both BPs but reduced threshold current at the 2° BP more than at the 1° BP. This blocker lowered V(TH) at both BPs, but the difference between the BPs remained. Firing patterns evoked at the 2° BP became similar to those evoked at the 1° BP in 4-AP. Thus 4-AP-sensitive channels may be more concentrated in the distal axon and control AP initiation and firing patterns there. Orthodromic APs between the two BPs were also compared. There was no difference in AP amplitude between the two BPs, but AP half-width recorded at the 2° BP was longer than that at the 1° BP. AP duration at both BPs increased gradually, by ∼17%, during a 100-Hz, 500-ms train (in-train rise). Normalized AP half-widths revealed a smaller fractional in-train rise at the 2° BP. Thus, although distal APs were broader, AP duration there was under more stringent control than that of the proximal axon. 4-AP increased AP amplitude and duration of the entire orthodromic train and reduced the magnitude of the in-train rise in AP half-width at both BPs. However, this blocker did not uncover a clear difference between the two BPs. Thus 4-AP-sensitive channels concentrated in distal axon may be essential in preventing unintended firing and modulating AP waveform without interfering with orthodromic AP propagation.

Early postnatal surge of serum Clara cell secretory protein in newborn infants

BACKGROUND

Clara cell secretory protein (CCSP) is an anti-inflammatory mediator, but its role in neonatal lung adaptation and diseases is uncertain.

OBJECTIVE

To characterize postnatal changes in serum CCSP in relation to gestation, respiratory disease (RDS) and bronchopulmonary dysplasia (BPD) in comparison with other anti-inflammatory cytokines (IL-4, -10 and -13).

METHODS

Blood was collected from 76 infants (26 of 23-29 weeks' gestation, 33 of 30-36 weeks' gestation and 17 term infants) at birth (preterm cord blood); on admission; at 12, 24 and 48 h; and on days 3-4 and 7 of life. CCSP was assayed by ELISA and cytokines by Bio-Plex.

RESULTS

Median serum CCSP in extremely and moderately preterm infants rose from a baseline of 13.6 and 15.9 to 33.4 ng/ml (p = 0.04) and 59.8 ng/ml (p = 0.03) at 12 h of age, respectively. CCSP levels were highest in term infants (80.7 ng/ml at 12 h). CCSP then decreased to 22.5 ng/ml on days 3-4 (p = 0.001). CCSP of 37 RDS infants fell to a lower baseline on days 4 and 7 than that of the 22 non-RDS preterms. The 8 infants who developed BPD had persistently low serum CCSP (12.7 ng/ml at 12 h). In contrast, early postnatal changes were not seen in IL-4, -10 and -13 levels, but low IL-10 and -13 levels were found on day 7 in BPD infants.

CONCLUSIONS

Serum CCSP levels were characterized by an early postnatal surge. This apparent gestation-influenced surge may represent an initiation of a protective cascade against postnatal lung injury during extrauterine adaptation.

Identification of novel Bartonella spp. in bats and evidence of Asian gray shrew as a new potential reservoir of Bartonella

Many studies indicated that small mammals are important reservoirs for Bartonella species. Using molecular methods, several studies have documented that bats could harbor Bartonella. This study was conducted to investigate the relationship of Bartonella spp. identified in bats and small mammals living in the same ecological environment. During May 2009 and March 2010, a total of 102 blood specimens were collected. By whole blood culture and molecular identification, a total of 6 bats, 1 rodent and 9 shrews were shown to be infected by Bartonella species. After sequencing and phylogenetic analyses of the sequences of gltA, ftsZ, rpoB and ribC genes, these specific isolates from bats were not similar to the known Bartonella species (the similarity values were less than 91.2%, 90.5%, 88.8%, and 82.2%, respectively); these isolates formed an independent clade away from other known Bartonella type strains. The Bartonella spp. isolated from small mammals, which were closely related to Bartonella tribocorum, Bartonella elizabethae, Bartonella grahamii, Bartonella rattimassiliensis and Bartonella queenslandensis, were similar to the findings in previous studies worldwide. Therefore, the results implied that the species of Bartonella strains isolated from small mammals were different from those identified in bats. Our results strongly suggested that the bat isolate could be a new Bartonella species. This study is also the first one to isolate Bartonella organisms from Asian gray shrews, Crocidura attenuata tanakae.

Unknown fever and back pain caused by Bartonella henselae in a veterinarian after a needle puncture: a case report and literature review

Bartonella henselae, the etiologic agent of cat-scratch disease, rarely causes back pain and is considered to be transmitted through animal scratches and bites. Here we report a cat-scratch disease case possibly with an unusual route of transmission. The patient was a 32-year-old man, and he was working as a veterinarian in a private veterinary clinic. He sought for clinical help because of unknown fever and persistent back pain for at least a month after an accidental needle puncture. Through serological testing and molecular identifications, this clinical case was confirmed to be caused by B. henselae.

Isolation of Bartonella species from rodents in Taiwan including a strain closely related to 'Bartonella rochalimae' from Rattus norvegicus

An increasing number of Bartonella species originally isolated from small mammals have been identified as emerging human pathogens. During an investigation of Bartonella infection in rodent populations carried out in Taiwan in 2006, a total of 58 rodents were tested. It was determined that 10.3 % (6/58) of the animals were Bartonella bacteraemic. After PCR/RFLP analysis, four isolates were identified as Bartonella elizabethae and one isolate as Bartonella tribocorum. However, there was one specific isolate with an unrecognized PCR/RFLP pattern. After further sequence and phylogenetic analyses of the gltA, ftsZ and rpoB genes, and the 16S-23S rRNA intergenic spacer region, the results indicated that this specific isolate from Rattus norvegicus was closely related to human pathogenic 'Bartonella rochalimae'. Further studies need to be conducted to evaluate whether this rodent species could be a reservoir for 'B. rochalimae'.

Intracranial pressure fluctuation during hemodialysis in renal failure patients with intracranial hemorrhage

Coagulopathy in renal failure patients often makes them vulnerable to intracranial hemorrhage. Emergency decompression to remove the hematoma and to stop bleeding is always indicated. After the surgery, hemodialysis (HD) should be arranged to maintain the BUN/Cr. level, and I/O balance. During HD, intracranial pressure in all of the patients in this study fluctuated. This phenomenon always resulted in neurological deterioration in acute or chronic renal failure. We present intracranial pressure (ICP) changes during HD in five acute or chronic renal failure patients with intracranial hemorrhage. They all underwent craniectomy or craniotomy with ICP monitors implantation. Different HD protocols were arranged for these patients and then we observed clinical results. ICP elevated during HD and resulted in severe brain swelling. This situation was one of the clinical presentations of dialysis disequilibrium syndrome (DDS). Four patients died because of this complication and one survived. ICP fluctuation seemed to be correlated with the fluid amount and frequency of HD. The prevalence and pathophysiology of DDS remain unclear. Renal failure patient with intracranial hemorrhage may be complicated with DDS when HD was performed. An attempt to reduce the fluid amount and to increase the frequency of HD might help these patients.

Phylogenetic analysis of parapoxviruses and the C-terminal heterogeneity of viral ATPase proteins

Two outbreaks of orf virus (a parapoxvirus) infection in goats found in Nantou and Taiping of central Taiwan were investigated. The nucleotide and the amino acid sequences of viral B2L, E3L and A32L genes in these two outbreaks were analyzed, and each of their phylogenetic trees were also constructed. In the A32L gene, an unexpected deletion of 24 nucleotides was found in the Taiping strain. The A32L gene can encode an ATPase and is supposed to be involved in virion DNA packaging. The 24 nucleotides correspond to 8 amino acids residues of the viral ATPase, which are located near the C-terminal region of the enzyme. Moreover, two copies of the RGD sequence at C-terminal region of ATPase were found in the Nantou strain. The 24-nucleotide difference in the A32L gene indicated that the Nantou strain and the Taiping strain were two separate strains, and it can be used in differential molecular diagnosis. Moreover, the C-terminal heterogeneity was found to be a general feature of the viral ATPase. Lastly, similar functional motifs of the ATPase and the Ras proto-oncoprotein (a GTPase) are discussed.

Electrophysiological events recorded at presynaptic terminals of the crayfish neuromuscular junction with a voltage indicator

The water-soluble voltage indicator JPW1114 was used to stain thin axons and terminal varicosities of the crayfish neuromuscular junction. A slow, overnight injection protocol was developed to brightly stain fine structures without cytotoxicity. Fluorescence transients filtered at 2 kHz showed that the duration of terminal action potentials was shorter than that of those recorded in the main trunk of the axons. In addition, the repolarization phases of the terminal and axonal action potentials overlapped in time, suggesting that the entire axonal arborization repolarizes simultaneously. Manipulating resting membrane potential, +/-15-20 mV, did not alter the peak level or duration of action potentials if they fired in isolation. A prolongation of action potential, by 23%, could be induced if a 10-spike burst at 100 Hz was fired from depolarized membrane potential. No such change was observed when the high frequency train was fired from resting or hyperpolarized levels. Microelectrodes in the main trunk of axons typically recorded a depolarizing after-potential (DAP) following an action potential initiated from resting membrane potential. The DAP could be inverted and enlarged by depolarization and hyperpolarization, respectively. Fluorescence transients recorded from terminals exhibited similar DAP characteristics. The ratio of DAP to action potential amplitude recorded from terminals was similar to that recorded from the main axon. Thus, the entire axonal arborization returned to resting level in a spatially uniform manner during the DAP. The functional significance of DAP is discussed in the light of these observations.

Hypofractionated CyberKnife stereotactic radiosurgery for acoustic neuromas with and without association to neurofibromatosis Type 2

CyberKnife stereotactic radiosurgery (CKSRS) has been proved effective in treating intra-cranial lesions. To treat acoustic neuroma (AN) patients with or without neurofibromatosis Type 2 (NF2) associations, the functional preservation of hearing, trigeminal nerve, and facial nerve are important. Twenty-one patients were treated with hypofractionated CKSRS. Fourteen non-NF2 and seven NF2 patients were enrolled. Cranial nerve function, audiograms, and magnetic resonance images (MRI) were monitored. Mean follow-up was 15 month. Tumors with volumes ranging from 0.13 to 24.8 cm3 (mean 5.4 cm3) were irradiated with the marginal dose 1800-2000 cGy/3 fractions. Tumors were treated with an 80 to 89% isodose line (mean 83%) and mean 97.9% tumor coverage. Two patients experienced hearing deterioration (16.7%) in the non-NF2 group, and 3 patients (50%) in the NF2 group. No facial or trigeminal dysfunction, brain stem toxicity, or cerebellar edema occurred. Tumor regression was seen in 9 patients (43%) and stable in 12 patients (57%). 100% tumor control rate was achieved. Hypofractionated CKSRS was not only effective in tumor control but also excellent in hearing preservation for non-NF2 AN. But for NF2 patients, although the tumor control was remarkable, hearing preservation was modest as in non-NF2 patients.

Evaluation of optimal cerebral perfusion pressure in severe traumatic brain injury

Traumatic brain injury (TBI) is a major cause of death and disability. In the 2000 guidelines, one of the suggestions for TBI treatment was to maintain cerebral perfusion pressure (CPP) < or = 70 mmHg. But in the 2003 guidelines, the suggestion was changed to < or = 60 mmHg. There have been some discrepancies of opinions about this recommendation in recent publications. In this study, we retrospectively reviewed 305 severe TBI (STBI) patients with Glasgow Coma Scales (GCS) < or = 8 between January 1, 2002 and March 31, 2003. The study group was stratified according to use or nonuse of intracranial pressure (ICP) monitoring, ICP levels, ages, and GCS levels in order to test the correlation between CCP and the prognosis. The patients < 50-year-old, with higher GCS level, with ICP monitoring, and with ICP levels < 20 mmHg had lower mortality rates and better prognosis (GOS) (p < 0.05 or 0.001). The patients in the GCS 3-5 subgroup had a significantly lower mortality and better prognosis if the CPP value was maintained higher than 70 mmHg (p < 0.05) The optimal CPP maintained < or = 60 mmHg did not fit in all STBI patients. Our study concludes that it is critical to maintain CPP substantially higher in lower GCS level patients.

Effect of hyperbaric oxygen on patients with traumatic brain injury

Hyperbaric oxygen therapy (HBOT) is the medical therapeutic use of oxygen at a higher atmospheric pressure. The United States Food and Drug Administration have approved several clinical applications for HBOT, but HBOT in traumatic brain injury (TBI) patients has still remained in controversial. The purpose of our study is to evaluate the benefit of HBOT on the prognosis of subacute TBI patients. We prospectively enrolled 44 patients with TBI from November 1, 2004 to October 31, 2005. The study group randomly included 22 patients who received HBOT after the patients' condition stabilization, and the other 22 corresponding condition patients were assigned into the matched control group who were not treated with HBOT. The clinical conditions of the patients were evaluated with the Glasgow Coma Scale (GCS) and Glasgow Outcome Scale (GOS) before and 3 to 6 months after HBOT. The GCS of the HBOT group was improved from 11.1 to 13.5 in average, and from 10.4 to 11.5 (p < 0.05) for control group. Among those patients with GOS = 4 before the HBOT, significant GOS improvement was observed in the HBOT group 6 months after HBOT. Based on this study, HBOT can provide some benefits for the subacute TBI patients with minimal adverse side effects.

Neurotrauma research in Taiwan

Because of the rapid industrial and economic growth, Taiwan and other developing countries have faced an enormous increase in the number of motorcycles, which has subsequently caused a rapid increase of the motorcycle-related traumatic brain injuries (TBI). In order to tackle this serious problem, stepwise approaches for TBI were implemented in Taiwan from 1991 to 2007. Step 1 was to do a nationwide TBI registry in order to identify the risk factors and determinants. We found that the major cause of TBI in Taiwan was motorcycle-related injury, and very few motorcyclists wore a helmet. Step 2 was to launch the implementation of the helmet use law on June 1, 1997. A rapid decline of TBI hospitalizations and deaths was demonstrated soon thereafter. Step 3 was to enroll into international collaborations with the Global Spine and Head Injury Prevention Project (Global SHIP Project) groups for TBI. The comparative results thus obtained could be used to develop prevention strategies for developing countries. Step 4 was to implement clinical researches for TBI, which included a Propofol study, hyperbaric oxygen therapy (HBOT), brain parenchymal oxygen (PbtO2) monitoring, etc. Step 5 was to develop guidelines for the management of severe TBI in Taiwan. Through a 2-year period of review, discussion, and integration, a 9-chapter guideline was published in June 2007. In summary, our experience and process for management of TBI in Taiwan can be used as a reference for other developing countries.

Identification and phylogenetic analysis of orf virus from goats in Taiwan

An outbreak of contagious ecthyma in goats in central Taiwan was investigated. The disease was diagnosed by physical and histopathologic examinations, and the etiology of the disease was identified as orf virus by electron microscopy and polymerase chain reaction (PCR) and sequence of major envelope protein (B2L) gene. The entire protein-coding region of B2L gene were cloned and sequenced. Phylogenetic analysis of B2L amino acid sequences showed that the orf virus identified in this outbreak was closer to the Indian ORFV-Mukteswar 59/05 isolate. This is the first report on the molecular characterization of orf virus in Taiwan.

Separation, cultivation and biological characteristics of oral carcinoma-associated fibroblasts

OBJECTIVES

Carcinoma-associated fibroblasts (CAFs) have been suggested to regulate the initiation and progression of many types of solid tumors. The aim of the study was to separate, cultivate, identify oral CAFs, and to investigate their biological characteristics.

MATERIALS AND METHODS

The primary CAFs and normal fibroblasts (NFs) of the tongue were obtained by tissue culture. Then cells were dissociated by 0.25% trypsin and purified by curettage method combining with trypsinization. The cells were verified according to morphological observation and immunohistochemical staining of certain proteins. Multiple proliferation indexes and karyotype of the cells were assayed.

RESULTS

Third passage purified oral CAFs and NFs were attained successfully. The morphological characteristics of the CAFs changed significantly comparing to the NFs. The CAFs showed positive staining for vimentin, alpha-smooth muscle actin and matrix metalloproteinases-2. The proliferation and mitosis ability of the CAFs were significantly increased compared with the NFs (P < 0.05). No karyotypic abnormalities were found in the CAFs.

CONCLUSIONS

There were obvious differences in the biological characteristics between oral CAFs and NFs. The results may provide us an experimental foundation for further studies on the roles of CAFs in the initiation and progression of oral cancer.