Neurophilic herpesvirus: a powerful tool for neuroscience research / 生物工程学报

Viruses are powerful tools for the study of modern neurosciences. Most of the research on the connection and function of neurons were done by using recombinant viruses, among which neurotropic herpesvirus is one of the most important tools. With the continuous development of genetic engineering and molecular biology techniques, several recombinant neurophilic herpesviruses have been engineered into different viral tools for neuroscience research. This review describes and discusses several common and widely used neurophilic herpesviruses as nerve conduction tracers, viral vectors for neurological diseases, and lytic viruses for neuro-oncology applications, which provides a reference for further exploring the function of neurophilic herpesviruses.

Study on reverse transsynaptic virus tracing targeting Shenmen (HT7) and heart in mice / 针灸推拿医学（英文版）

Objective: To investigate the neural connections between Shenmen (HT7)-heart and the brain by observing the tracing viruses co-labeled brain nuclear groups after injection of the pseudorabies viruses (PRV), the reverse transsynaptic virus tracer carrying different fluorescent protein genes, into the myocardium and Shenmen (HT7) point, respectively.Methods: Pseudorabies virus 531 (PRV531) carrying the green fluorescent protein gene and pseudorabies virus 724 (PRV724) carrying the red fluorescent protein gene were injected into the left ventricular wall and Shenmen (HT7) point area of the left forelimb of six C57BL/6 mice, respectively. After 120 h, whole brain tissue was extracted under 4％ paraformaldehyde perfusion to prepare brain sections. Neuronal co-labeling with the tracing viruses was observed under fluorescence microscopy. Results: Co-labeled signals from the mouse ventricular wall and Shenmen (HT7) point region were found at all levels of the mouse central nervous areas, such as the cerebral cortex, hypothalamus, midbrain, pons, and medulla oblongata. The number of co-labeled neurons was higher in the primary motor area, the hypothalamic paraventricular nucleus, the subceruleus nucleus, and the paramedian reticular nucleus. Conclusion: There is a neural connection between Shenmen (HT7), the heart, and the brain, which may be most closely related to the autonomic nervous system.

Progress in pathogenic mechanisms of neurotropic viruses crossing blood-brain barrier and invading central nervous system / 中华微生物学和免疫学杂志

Blood-brain barrier is a natural barrier between blood and brain tissue that can protect the brain from invasion by infectious pathogens in blood and maintain the homeostasis of the brain environment. However, neurotropic viruses can escape or disrupt blood-brain barrier and then invade the brain, causing serious complications in the central nervous system such as encephalitis and meningitis, which seriously threaten human life. This paper mainly summarized the research progress in the pathogenic mechanisms of common neurotropic viruses crossing blood-brain barrier and invading the central nervous system.

Atorvastatin ameliorates viral burden and neural stem/ progenitor cell (NSPC) death in an experimental model of Japanese encephalitis

Japanese encephalitis virus, a neurotropic flavivirus, causes sporadic encephalitis with nearly 25% fatal casereports. JEV infects neural stem/progenitor cells (NSPCs) and decreases their proliferation. Statin, a commonlyused class of cholesterol lowering drug, has been shown to possess potent anti-inflammatory and neuroprotective effects in acute brain injury and chronic neurodegenerative conditions. Here, we aimed to check theefficacy of atorvastatin in alleviating the symptoms of Japanese encephalitis (JE). Using BALB/c mouse modelof JEV infection, we observed that atorvastatin effectively reduces viral load in the subventricular zone (SVZ)of infected pups and decreases the resultant cell death. Furthermore, atorvastatin abrogates microglial activation and production of proinflammatory cyto/chemokine production post JEV infection in vivo. It alsoreduced interferon-b response in the neurogenic environs. The neuroprotective role of atorvastatin is againevident from the rescued neurosphere size and decreased cell death in vitro. It has also been observed that uponatorvastatin administration, cell cycle regulatory proteins and cell survival proteins are also restored to theirrespective expression level as observed in uninfected animals. Thus the antiviral, immunomodulatory andneuroprotective roles of atorvastatin reflect in our experimental observations. Therefore, this drug broadens apath for future therapeutic measures against JEV infection.

Ataxias cerebelosas e infecciones virales: caracterización clínica y mecanismos neuropatogénicos / Cerebellar ataxias and viral infections: clinical characterization and neuropathogenic mechanisms

Introducción: La ataxia constituye una alteración en la coordinación de los movimientos, resultado de una disfunción del cerebelo, sus conexiones, así como alteraciones en la médula espinal, nervios periféricos o una combinación de estas condiciones. Las ataxias se clasifican en hereditarias, esporádicas y en adquiridas o secundarias, en las cuales los virus neurotrópicos constituyen los principales causantes. Objetivo: Actualizar los conocimientos relacionados con las ataxias causadas por virus neurotrópicos y los mecanismos neurodegenerativos que pudieran tener relación con la ataxia. Métodos: Se realizó una revisión bibliográfica incluyendo artículos publicados en las principales bases de datos bibliográficas (Web of Sciences, Scopus, SciELO). Se utilizaron las palabras claves: ataxia, virus neurotrópicos, ataxias cerebelosas, ataxias infecciosas, en inglés y español. Análisis e integración de la información: Los virus más conocidos que provocan ataxias infecciosas son el virus de inmunodeficiencia humana, virus del herpes simple, virus del herpes humano tipo 6, virus de la varicela zoster, virus Epstein-Barr, virus del Nilo Occidental, y enterovirus 71, aunque existen otros virus que causan esta afectación. Los mecanismos neuropatogénicos sugeridos son la invasión directa del virus y procesos inmunopatogénicos desencadenados por la infección. Estos virus pueden causar ataxia cerebelosa aguda, ataxia aguda posinfecciosa, síndrome opsoclono-mioclono-atáxico y ataxia por encefalomielitis aguda diseminada. Aunque la mayoría de los reportes de casos informan la evolución satisfactoria de los pacientes, algunos refieren complicaciones neurológicas e incluso la muerte. Conclusiones: Actualmente existe la necesidad de profundizar en el estudio de este tipo de ataxia para favorecer su diagnóstico y tratamiento(AU)

Introduction: Ataxia is an alteration in the coordination of movements caused by a dysfunction of the cerebellum and its connections, as well as alterations in the spinal cord, the peripheral nerves, or a combination of these factors. Ataxias are classified into hereditary, sporadic and acquired or secondary, in which neurotropic viruses are the main causative agents. Objective: Update knowledge about ataxias caused by neurotropic viruses and the neurodegenerative mechanisms which could bear a relationship to ataxia. Methods: A review was conducted of papers published in the main bibliographic databases (Web of Sciences, Scopus, SciELO), using the search terms ataxia, neurotropic virus, cerebellar ataxias, infectious ataxias, in English and in Spanish. Discussion: The best known viruses causing infectious ataxias are the human immunodeficiency virus, herpes simplex virus, human herpesvirus 6, varicella zoster virus, Epstein-Barr virus, Western Nile virus and enterovirus 71, though other viruses may also cause this condition. The neuropathogenic mechanisms suggested are direct invasion of the virus and immunopathogenic processes triggered by the infection. These viruses may cause acute cerebellar ataxia, acute postinfectious ataxia, opsoclonus-myoclonus-ataxia syndrome and ataxia due to acute encephalomyelitis disseminata. Though most case reports describe a satisfactory evolution of patients, some refer to neurological complications and even death. Conclusions: There is a current need to carry out further research about this type of ataxia to improve its diagnosis and treatment(AU)

Fatal dengue encephalitis in a recruit: lessons learnt

Dengue infections may present within a widely variable spectrum of clinical manifestations. However, neurologic complications in general are rare and unusual. A 19 yrs old healthy male army recruit was brought to a service hospital in South India in a state of unresponsiveness, following 12 km route march. Despite aggressive and prompt management, his condition progressively deteriorated and he finally passed away about 10 hrs after reporting to the hospital. The final cause of death was acute dengue encephalitis with raised intracranial pressure. Epidemio-clinico-pathological correlation in this case led to the conclusion that vigorous exertion with a hyper-metabolic state of fever in a setting of encephalitis led to metabolic injury, multi-organ failure, cerebral edema and intracranial hemorrhage. Encephalitis following dengue virus (DENV) infection is a rare phenomenon with the incidence ranging from 0.5% to 6.2%. Neurological features associated with DENV were first reported by Sanguansermsri et al in 1976. The rare neurologic presentations reported with DENV infection are transverse myelitis, acute encephalomyelitis, myositis, and gullain barre syndrome. As encephalitis caused by DENV mimics that caused by other pathogens it should always be kept in mind while managing encephalitis of unknown origin. Medical officers should maintain a high index of suspicion of DENV encephalitis. Training of medical officers; therefore, needs to be undertaken with regular refresher cadres, besides equipping of all peripheral facilities with rapid diagnostic kits for dengue. The same will ensure prompt detection of cases and timely referral to higher medical centres in chain. The instant case reflects an important, potentially fatal, complication of dengue. Pathophysiology of DENV encephalitis needs to be elucidated on priority through research involving all stakeholders.

A self-controlled study on corneal nerve invasion phenomenon of Bowman's membrane in patients with ⅢA lattice corneal dystrophy / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To analyze and study the corneal nerve invasion phenomenon of Bowman's membrane in patients with IIIA lattice corneal dystrophy by confocal laser scanning microscopy. Quantitative analysis of 10a continuous observation image data was performed, followed by self-control studies.<p>METHODS: A total of 10 patients(13 eyes)with IIIA Lattice corneal dystrophy were continuously examined by confocal laser scanning microscopy. The data were observed and analyzed. <p>RESULTS: The normal corneal nerve of Bowman's membrane(Grade 0)of IIIA LCD patients gradually decreased with the prolongation of observation time. The nerves of grade I to V involved(amyloid-wrapped nerve fibers)gradually increased correspondingly. So suggested that the corneal nerve invasion of Bowman's membrane(amyloid deposits)in patients with IIIA LCD were gradually increasing with time. <p>CONCLUSION: In patients with type ⅢA lattice corneal dystrophy, there is a neurotropic phenomenon in Bowman's membrane, which gradually worsens with the aggravation of the lesion. This lesion can explain the recurrent epithelial damage of the IIIA LCD from some degrees. Continuous observation of patients with type IIIA LCD by corneal laser confocal microscopy can well understand the development of the lesion and explain its clinical manifestations.

Trans-synaptic Neural Circuit-Tracing with Neurotropic Viruses / 神经科学通报·英文版

A central objective in deciphering the nervous system in health and disease is to define the connections of neurons. The propensity of neurotropic viruses to spread among synaptically-linked neurons makes them ideal for mapping neural circuits. So far, several classes of viral neuronal tracers have become available and provide a powerful toolbox for delineating neural networks. In this paper, we review the recent developments of neurotropic viral tracers and highlight their unique properties in revealing patterns of neuronal connections.

Cortical Organization of Centrifugal Afferents to the Olfactory Bulb: Mono- and Trans-synaptic Tracing with Recombinant Neurotropic Viral Tracers / 神经科学通报·英文版

Sensory processing is strongly modulated by different brain and behavioral states, and this is based on the top-down modulation. In the olfactory system, local neural circuits in the olfactory bulb (OB) are innervated by centrifugal afferents in order to regulate the processing of olfactory information in the OB under different behavioral states. The purpose of the present study was to explore the organization of neural networks in olfactory-related cortices and modulatory nuclei that give rise to direct and indirect innervations to the glomerular layer (GL) of the OB at the whole-brain scale. Injection of different recombinant attenuated neurotropic viruses into the GL showed that it received direct inputs from each layer in the OB, centrifugal inputs from the ipsilateralanterior olfactory nucleus (AON), anterior piriform cortex (Pir), and horizontal limb of diagonal band of Broca (HDB), and various indirect inputs from bilateral cortical neurons in the AON, Pir, amygdala, entorhinal cortex, hippocampus, HDB, dorsal raphe, median raphe and locus coeruleus. These results provide a circuitry basis that will help further understand the mechanism by which olfactory information-processing in the OB is regulated.

The clinical profile and outcome of children with Dengue Encephalitis at the Philippine Children’s Medical Center: A retrospective study from January 2011-June 2017

Background@#Dengue, a mosquito-borne flavivirus, is hyperendemic in the Philippines. One of its rare complication is dengue encephalitis, characterized by altered sensorium, elevated liver enzymes, and high dengue-specific antibody titers. Previously known as non-neurotropic, dengue presents with an increasing incidence of neurologic manifestations. @*Objective@#To describe the clinico-demographic profile and outcome of laboratory-confirmed dengue encephalitis patients. @*Methods@#This is a retrospective study that used purposive sampling to describe laboratory-confirmed dengue encephalitis cases aged 0-18 years. The clinico-demographic profiles and outcomes were collected using chart review, and variables were analyzed using descriptive statistics. @*Results@#14 laboratory-confirmed cases were reviewed. Most (57%) were males aged 3 days-15 years. Fever lasted 3-11 days. Following nonspecific signs and symptoms, neurological manifestations developed within 1-5 days, the most common being seizures (71%). Majority (57%) had anemia. All, except one, exhibited leukopenia and thrombocytopenia. Elevated liver enzymes, bleeding parameter derangements, electrolyte, and glucose imbalances were noted. All were seropositive for dengue IgM, and 5 dengue IgM in the CSF. Most common EEG findings showed generalized slowing. Neuroimaging reports were normal in some or showed cerebral edema in the others. Half of the patients recovered fully, 3 showing partial recovery from neurologic changes, and 3 others had neurologic sequelae. One infant expired. @*Conclusions and Recommendations@#Dengue encephalitis should be considered in patients living in an endemic country, presenting with fever with neurologic changes or elevated liver enzymes, with a risk for developing neurologic sequelae or death.

Effects of propofol sedation on BDNF-TrkB/p75 signal and cognitive function in rat hippocampus / 上海交通大学学报（医学版）

Objective·To detect the effects of propofol sedation on cognitive function in rats and its mechanism. Methods?·?Forty-eight SD rats were randomly divided into three groups, i.e. control group, 100?mg/kg group and 300?mg/kg group. Rats were administrated intraperitoneally with propofol (10?mg/mL, 100?mg/kg or 300?mg/kg). The mRNA levels of brain derived neurotropic factor (BDNF)-TrkB/p75 signal molecules in rat hippocampus were evaluated by realtime PCR 45 min after propofol treatment. Learning and memory ability was examined by inhibitory avoidance (IA) test after propofol treatment. Results?·?The mRNA levels of BDNF in the hippocampal tissue were (1.20±0.13) fold (P=0.002) and (88±12) % (P=0.044) of that in control group, respectively, in 100?mg/kg group and 300?mg/kg group after injection of propofol. The mRNA levels of TrkB were (1.01±0.11) fold ( P=0.982) and (86±11) % (P=0.018) of that in control group, respectively, in 100?mg/kg group and 300?mg/kg group. The mRNA levels of p75 were (1.02±0.10) fold (P=0.778) and (1.59±0.18) fold (P=0.000) of that in control group, respectively, in 100?mg/kg group and 300?mg/kg group. There was no significant difference of the 24 h IA memory retention latency between 100?mg/kg group and control group. The 24 h IA memory retention latency in 300?mg/kg group was significantly decreased compared with control group (P=0.028) and 100?mg/kg group (P=0.020). Conclusion?·?Propofol dose-dependently regulates the expression of BDNF-TrkB/p75 signal molecules, and high dose propofol may reduce cognitive function via BDNF-TrkB/p75 signal.

Association between the Brain-Derived Neurotropic Factor and Attention Deficit Hyperactivity Disorder

Attention deficit hyperactivity disorder (ADHD) is a common childhood psychiatric disorder. Recently, it has been suggested that brain-derived neurotropic factor (BDNF) may play a role in the pathogenesis of ADHD. Our aim of this review is to understand the physiological functions of BDNF and its potential relationship with ADHD and therapeutic approaches of ADHD. Searches were conducted in Pubmed and Research Information Service System (RISS). In this review, we summarized important literatures for the physiological functions of BDNF in neurodevelopment, change of serum BDNF level in ADHD, association of BDNF polymorphism and ADHD and potential association of treatment of ADHD with serum BDNF level. Further studies are required to more clearly understand the source and the role of BDNF in ADHD and to develop BDNF based-ADHD treatement.

Effects of propofol sedation on BDNF-TrkB/p75 signal and cognitive function in rat hippocampus / 上海交通大学学报（医学版）

Objective • To detect the effects of propofol sedation on cognitive function in rats and its mechanism. Methods • Forty-eight SD rats were randomly divided into three groups, i.e. control group, 100 mg/kg group and 300 mg/kg group. Rats were administrated intraperitoneally with propofol (10 mg/mL, 100 mg/kg or 300 mg/kg). The mRNA levels of brain derived neurotropic factor (BDNF)-TrkB/p75 signal molecules in rat hippocampus were evaluated by realtime PCR 45 min after propofol treatment. Learning and memory ability was examined by inhibitory avoidance (IA) test after propofol treatment. Results • The mRNA levels of BDNF in the hippocampal tissue were (1.20±0.13) fold (P=0.002) and (88±12)% (P=0.044) of that in control group, respectively, in 100 mg/kg group and 300 mg/kg group after injection of propofol. The mRNA levels of TrkB were (1.01±0.11) fold (P=0.982) and (86±11)% (P=0.018) of that in control group, respectively, in 100 mg/kg group and 300 mg/kg group. The mRNA levels of p75 were (1.02±0.10) fold (P=0.778) and (1.59±0.18) fold (P=0.000) of that in control group, respectively, in 100 mg/kg group and 300 mg/kg group. There was no significant difference of the 24 h IA memory retention latency between 100 mg/kg group and control group. The 24 h IA memory retention latency in 300 mg/kg group was significantly decreased compared with control group (P=0.028) and 100 mg/kg group (P=0.020). Conclusion • Propofol dose-dependently regulates the expression of BDNF-TrkB/p75 signal molecules, and high dose propofol may reduce cognitive function via BDNF-TrkB/p75 signal.

Infección por virus del Zika en el embarazo, impacto fetal y neonatal / Zika virus infection in pregnancy, fetal and neonatal impact

Zika virus (ZV) is an arbovirus transmitted by Aedes aegypti and A. albopictus. The neurotropic profile of this virus is known since 1952. The main finding related to ZV in America is microcephaly. Two hypotheses are tested on its involvement in the central nervous system: its neurotropic feature and the direct effect of ZV on the placenta. Malformations and clinical findings on fetal development comprise congenital Zika syndrome. RT-PCR and serology (IgM) are useful for definitive diagnosis. However, we should keep in mind first that the viremia in pregnant women can stay for a longer period of time, and second, a positive IgM for Zika should be properly interpreted in an endemic area to other flavivirus. It is suggested to be part of TORCHS-Z complex the ZV infection in endemic areas.

El virus del Zika (VZ), arbovirus, es transmitido por Aedes aegypti y A. albopictus. Desde 1952 se conoce su perfil neurotrópico. El principal hallazgo relacionado con la infección en las Américas, es la microcefalia. Dos hipótesis se plantean sobre su afectación en el sistema nervioso central: su característica neurotrópica per se, y el efecto directo del virus sobre la placenta. Las malformaciones y hallazgos clínicos sobre el desarrollo fetal conforman el síndrome de Zika congénito. La reacción de polimerasa en cadena-transcriptasa reversa (RPC-TR) y serología (IgM) son útiles para el diagnóstico definitivo; sin embargo, debe tenerse en cuenta, primero, que la viremia en las mujeres embarazadas puede permanecer por un período más prolongado y segundo, que una IgM positiva para Zika, debe ser adecuadamente interpretada en un medio endémico para otros flavivirus. Se propone a la infección por el VZ, en zonas endémicas, como parte del complejo TORCHS-Z.

Cognitive-Enhancing Effect of Dianthus superbus var. Longicalycinus on Scopolamine-Induced Memory Impairment in Mice

Dianthus superbus (D. superbus) is a traditional crude drug used for the treatment of urethritis, carbuncles and carcinomas. The objective of this study was to confirm the cognitive enhancing effect of D. superbus in memory impairment induced mice and to elucidate the possible potential mechanism. Effect of D. superbus on scopolamine induced memory impairment on mice was evaluated using the Morris water maze and passive avoidance tests. We also investigated acetylcholinesterase (AChE) activity and brain-derived neurotropic factor (BDNF) expression in scopolamine-induced mice. HPLC-DAD analysis was performed to identify active compounds in D. superbus. The results revealed that D. superbus attenuated the learning and memory impairment induced by scopolamine. D. superbus also inhibited AChE levels in the hippocampi of the scopolamine-injected mice. Moreover, D. superbus increased BDNF expression in the hippocampus. Eight compounds were identified using HPLC-DAD analysis. The content of 4-hydroxyphenyl acetic acid was higher than contents of other compounds. These results indicated that D. superbus improved memory functioning accompanied by inhibition of AChE and upregulation of BDNF, suggesting that D. superbus may be a useful therapeutic agent for the prevention or treatment of Alzheimer's disease.

Adverse drug reactions and cost effectiveness of non-steroidal antiinfl ammatory drugs, muscle relaxants, and neurotropic drugs in patients with low back pain.

Background: The objective was to evaluate the adverse drug reactions (ADRs) and cost effectiveness of different classes of drugs in therapy of low back pain. Methods: A prospective observational study was carried out over a period of 12 months (November 2012 to November 2013) in which a total of 300 patients with low back pain were enrolled and divided equally into three groups – Group 1 (nonsteroidal anti-infl ammatory drugs [NSAIDs]), Group 2 (NSAIDs ± muscle relaxant), and Group 3 (NSAIDs ± muscle relaxant ± neurotropic drugs). Any ADR developed after the initiation of treatment at 3 weeks and 6 weeks was noted. Prescription cost per day was also calculated. Results: There was a male predominance in the study population with a mean age of 39.76±9.40 years. A total of 262 ADRs were noted among which most were seen in Group 3 (119 ADRs). Gastritis was the most common ADR in Group 1. Drowsiness was the most common ADR in Group 2 (30%) and 3 (46%). Prescription cost per day was highest in Group 3 (30.28±11.24 Indian Rupee [INR]) followed by Group 2 (25.92±8.66 INR) and Group 1 (12.22±3.38 INR). Conclusion: Patient on combination of three drugs (NSAIDs, muscle relaxants, and neurotropic agents) had maximum ADRs and their prescription cost per day was highest among the three groups.

Polymorphisms of BDNF Gene and Autism Spectrum Disorders: Family Based Association Study with Korean Trios

OBJECTIVE: Autism spectrum disorders (ASDs) are a group of early childhood-onset neurodevelopmental disorders characterized by deficits in social interaction and language skills, and repetitive behaviors. Brain-derived neurotrophic factor (BDNF) plays a critical role in the differentiation of normal neuronal cells during embryonic and postnatal neuronal development through its neurotrophic effects. METHODS: In this study, we performed a family-based association test (FBAT) between single nucleotide polymorphisms (SNPs; rs6265, rs11030101, rs7103411, and rs7103873) or haplotypes in the BDNF gene and affection status or several quantitative traits characterized by ADI-R with151 Korean trios, including a child diagnosed as ASDs. RESULTS: While no significant association was found between SNPs or haplotypes and the ASDs disease status, a quantitative transmission disequilibrium test (QTDT) by using quantitative traits identified associations of the SNPs (rs6265 and rs11030101) with a domain score for "Restricted, Repetitive and Stereotyped patterns of behavior" (C domain), especially at the subdomain scores for "encompassing preoccupation or circumscribed pattern of interest" (C1) (rs6265A allele, dominant model, p-value=0.019; rs11030101 A allele, additive model, p-value=0.015) and "preoccupations with part of objects or non-functional elements of material" (C4) (rs11030101 A allele, additive model, p-value=0.015) within the ADI-R diagnostic algorithm. In addition, significant associations were also identified between the haplotypes and these quantitative traits (C1, p-value=0.016; C4, p-value=0.012). CONCLUSION: We conclude that BDNF gene polymorphisms have a possible role in the pathogenesis of ASDs.

Characterization and comparison of the pathogenicity of viscerotropic velogenic Newcastle disease virus isolates in Korea / 대한수의학회지

A total of 18 Newcastle disease virus (NDV) isolates that were recovered from 1949 through 1997 were characterized and pathotyped. All viruses were highly virulent as determined by intracerebral pathogenicity indices > or = 1.81 in day-old. These pathotypes are typical for viscerotropic velogenic NDV (VVNDV) pathotype viruses. Some differences were observed for the chicken red blood cell elution rate and thermostability of the hemagglutinin at 56degrees C. Three antigenic groups were identified by a hemagglutination-inhibition assay using NDV monoclonal antibodies. And the predominant gross lesions were as follows: discharge from the nasal cavity, tracheal mucus, petechial hemorrhage in the heart fat, kidney urates and hemorrhage with or without necrosis in the gastrointestinal tract. Severe hemorrhagic or necrotic lesions were also noted in the lymphoid organs and were localized primarily in the spleen and cecal tonsil. However, differences in the occurrence and frequency of the gross lesions were observed between the virus strains. Among them, NDV strains that induced neurological symptoms belonged only to genotype VI. This strain had spread throughout Korea during the late 1980s to the 1990s, which suggests that specific VVNDVs genotypes might result in neurological symptoms.

Comparison of a conventional polymerase chain reaction with real-time polymerase chain reaction for the detection of neurotropic viruses in cerebrospinal fluid samples.

Purpose : To compare a conventional polymerase chain reaction (PCR) and real-time PCR for the detection of neurotropic DNA viruses. Materials and Methods : A total of 147 cerebrospinal fluid (CSF) samples was collected from patients attending a tertiary care hospital in South India for a period from 2005 to 2008. All these samples were tested using a conventional multiplex/uniplex PCR and a real-time multiplex/uniplex PCR. This technique was used to detect a large number of herpes viruses responsible for central nervous system infections, including HSV-1, HSV-2, VZV, CMV and EBV and the polyoma virus JCV. Results : Overall, in the entire set of samples, the real-time PCR yielded 88 (59.9%) positives and conventional PCR had six (4.1%) positives. Conclusion : Our results suggest that the real-time PCR assay was more sensitive compared with the conventional PCR. The advantage of real-time PCR is that it can be performed much faster than conventional PCR. Real-time PCR is less time-consuming, less labour-intensive and also reduces the chance of contamination as there is no post-amplification procedure. In the entire study population, the major viruses detected using real-time PCR were EBV (34%), HSV-2 (10.8%) and VZV (6.8%).