[Influential factors of non-motor symptoms prognosis in Parkinson's disease patients undergoing deep brain stimulation].

Objective: To investigate the effects of electrode activated contact location, volume of tissue activated (VTA) and age on non-motor symptoms, such as emotional symptoms and cognitive function, in Parkinson's disease (PD) patients with deep brain stimulation (DBS). Methods: PD patients who underwent DBS of subthalamic nucleus (STN) at the Department of Functional Neurosurgery of Beijing Tiantan Hospital from September 1, 2020 to August 31, 2022 were retrospectively enrolled. The International Parkinson and Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS), Hamilton Anxiety Scale (HAMA), Hamilton Depression Scale (HAMD), Montreal Cognitive Assessment (MoCA), and Mini-Mental State Examination Scales (MMSE) were used at the preoperative, 1-month and 12-month postoperative time points. In this study, patients were divided into middle-aged (age<60 years,n=39) and elderly (age≥60 years,n=62) groups to investigate the effect of age factor on the clinical outcome of surgery. Lead-DBS software was used to convert the patients' electrode reconstruction results into Montreal standard space, and the patients were divided into sensorimotor(n=43) and combined groups(n=53) according to the distribution of activation contact locations in the subzones of the STN. In addition, the patients were divided into a cognitive improvement group(n=57)and a cognitive deterioration group(n=44) based on the results of MoCA at 12 months. The positional information of the electrode activation contacts was collected and the VTA was calculated to analyze the effects on electrode activation electroshock location and activated tissue volume on patients' non-motor symptoms. Results: A total of 101 patients with PD were enrolled, including 46 males and 55 females, aged (62.6±8.4) years. Middle-aged patients had significantly higher MoCA scores, delayed recall scores, attention scores, and naming scores than older patients at 12 months postoperatively (all P<0.05). At 12-month follow-up, the improvement rate of MoCA score, HAMA score and HAMD score were -1.77%±20.36%, 39.65%±42.91% and 36.23%±45.45% respectively in sensorimotor group. At 12-month follow-up, the improvement rate of MoCA score, HAMA score and HAMD score was 11.69%±22.24%, 16.62%±68.10% and 2.30%±95.04% respectively in the combined group, and the difference between the two groups was statistically significant (MoCA: P=0.002; HAMA: P=0.040; HAMD: P=0.033) The distribution of VTA in the sensory motor area and marginal area of the left hemisphere STN in patients with improved cognitive function was significantly smaller than that in the deterioration group [(60.53±52.04)mm³vs (84.55±61.00)mm³, P=0.035; (41.81±33.36)mm³vs (59.05±45.46)mm³, P=0.030]. Conclusion: The effect of STN-DBS on emotional symptoms and cognitive function in PD patients is influenced by various factors and is closely related to the patient's age, electrode activation contact location and VTA.

[Influence of phosphoglycerate kinase 1 on metastasis and invasion of hepatoma cells and prognosis of liver cancer].

Objective: To investigate the association between expression of phosphoglycerate kinase 1 (PGK1) in liver cancer tissue and prognosis, as well as its influence on metastasis and invasion of hepatocellular carcinoma (HCC) cells. Methods: Overexpression and downregulated expression of PGK1 in HCC cells were mediated by lentivirus to establish hepatoma cell lines with different expression levels of PGK1. The Transwell chamber invasion assay, wound healing assay, and colony-forming assay were used to investigate the influence of PGK1 on metastasis, invasion, and proliferation of HCC cells. Immunohistochemistry was used to measure the expression of PGK1 in liver cancer tissue samples from 116 patients with hepatocellular carcinoma who underwent radical surgery, and the Kaplan-Meier method and the log-rank test were used to determine the association between PGK1 expression and prognosis of patients with liver cancer. Results: HCCLM3 and MHCC97H HCC cells with high metastatic potential had significantly higher expression of PGK1 than Hep3B and Huh7 HCC cells with low metastatic potential. Downregulation of PGK1 expression significantly inhibited the migration (31.2% ± 2.4% vs 12.0% ± 1.3%, t = 21.57, P < 0.01), invasion (58 ± 11 vs 21 ± 8, t = 4.687, P < 0.05), and colony-forming ability (168.6 ± 15.1 vs 118.4 ± 8.1, t = 6.650, P < 0.05) of MHCC97H cells, while overexpression of PGK1 enhanced the migration (62.8% ± 4.4% vs 83.6% ± 6.1%, t = 20.56, P < 0.01), invasion (80 ± 12 vs 121 ± 15, t = 4.603, P < 0.05), and colony-forming ability (52.3 ± 8.6 vs 84.7 ± 9.0, t = 27.18, P < 0.01) of Hep3B cells. The high PGK1 expression group had significantly shorter median disease-free survival time and mean survival time than the low PGK1 expression group (22.00 ± 8.51 vs not reached, P < 0.05; 46.00 ± 16.87 vs not reached, P < 0.01). Conclusions: PGK1 is involved in the regulation of metastasis and invasion of HCC cells and can promote the migration and invasion of HCC cells. Therefore, PGK1 may be an important predictor of prognosis and postoperative recurrence in patients with liver cancer.

Galectin-1 induces hepatocellular carcinoma EMT and sorafenib resistance by activating FAK/PI3K/AKT signaling.

Galectin-1 (Gal-1) is involved in several pathological activities associated with tumor progression and chemoresistance, however, the role and molecular mechanism of Gal-1 activity in hepatocellular carcinoma (HCC) epithelial-mesenchymal transition (EMT) and sorafenib resistance remain enigmatic. In the present study, forced Gal-1 expression promoted HCC progression and sorafenib resistance. Gal-1 elevated αvß3-integrin expression, leading to AKT activation. Moreover, Gal-1 overexpression induced HCC cell EMT via PI3K/AKT cascade activation. Clinically, our data revealed that Gal-1 overexpression is correlated with poor HCC survival outcomes and sorafenib response. These data suggest that Gal-1 may be a potential therapeutic target for HCC and a biomarker for predicting response to sorafenib treatment.

Unilateral lesion of the nigrostriatal pathway induces a transient decrease of firing rate with no change in the firing pattern of neurons of the parafascicular nucleus in the rat.

Electrophysiological recordings of thalamic parafascicular nucleus neurons were done in normal rats and in three groups of rats at different time intervals after injection of 6-hydroxydopamine into the pars compacta of substantia nigra. In normal rats, parafascicular neurons exhibited low firing rates (3.88+/-0.80 spikes/s). Concerning the pattern, 59% of the units discharged irregularly and 41% exhibited bursty pattern. In rats with 6-hydroxydopamine lesions, the firing rate decreased significantly during the first week post-lesion (1.15+/-0.36 spikes/s, P<0.01). During the second week, the firing rate was slightly, but not significantly, lower (2.59+/-0.41 spikes/s, P>0.05) than that of normal rats to return to the basal level three weeks post-lesion (3. 66+/-0.41 spikes/s, P>0.05). In these three groups of 6-hydroxydopamine-lesioned rats, the firing pattern showed no change when compared to control animals. These results show that the lesion of nigral dopaminergic neurons induced a transient decrease of the firing rate of parafascicular neurons with no change in the firing pattern demonstrating the absence of a stable influence of the dopaminergic system on the spontaneous activity of parafascicular neurons.

Effect of high-frequency stimulation of the subthalamic nucleus on the neuronal activities of the substantia nigra pars reticulata and ventrolateral nucleus of the thalamus in the rat.

Electrophysiological recordings were made in anaesthetized rats to investigate the mode of function of high-frequency stimulation of the subthalamic nucleus used as a therapeutic approach for Parkinson's disease. High-frequency electrical stimulation of the subthalamic nucleus (130 Hz) induced a net decrease in activity of all cells recorded around the site of stimulation in the subthalamic nucleus. It also caused an inhibition of the majority of neurons recorded in the substantia nigra pars reticulata in normal rats (94%) and in rats with 6-hydroxydopamine lesions of the substantia nigra pars compacta (90%) or with ibotenic acid lesions of the globus pallidus (79.5%). The majority of cells recorded in the ventrolateral nucleus of the thalamus responded with an increase in their activity (84%). These results show that high-frequency stimulation of the subthalamic nucleus induces a reduction of the excitatory glutamatergic output from the subthalamic nucleus which results in deactivation of substantia nigra pars reticulata neurons. The reduction in tonic inhibitory drive of nigral neurons induces a disinhibition of activity in the ventrolateral motor thalamic nucleus, which should result in activation of the motor cortical system.

High-frequency stimulation of the subthalamic nucleus suppresses experimental resting tremor in the monkey.

The effect of high-frequency stimulation of the subthalamic nucleus on parkinsonian-like resting tremor was investigated in two monkeys (Macaca fascicularis). Unilateral tremor of the arm and leg was induced by electrical coagulation of the brainstem area including the substantia nigra and the red nucleus. The tremor was only seen at rest condition with a very stable frequency of 4.46+/-0.59 Hz (mean+/-S.D.). Apomorphine (0.10-0.4 mg/kg, s.c.) completely blocked the tremor, suggesting that it was a dopaminergic-dependent symptom just like the parkinsonian tremor. When the stimulating frequency varied from 20 to 1000 Hz, both mono- and bipolar stimulation (square pulses, 0-5 mA, 0.06 ms) of the subthalamic nucleus suppressed resting tremor in a frequency-dependent manner but monopolar stimulation was more effective. These effects remained stable for more than two years. The present results suggest that the subthalamic nucleus is involved in the control and mechanism of resting tremor and that the high-frequency stimulation of the subthalamic nucleus can be used as an alternative therapy in parkinsonian patients with akinesia, rigidity and resting tremor.

Metastatic models of human liver cancer in nude mice orthotopically constructed by using histologically intact patient specimens.

In this study of orthotopic implantation of histologically intact surgical specimens, the authors constructed metastatic models of human hepatocellular carcinoma (HCC) in nude mice. Histologically intact human liver cancer specimens, derived from patients, were implanted directly into the liver of nude mice, and their orthotopic growth and metastases were observed. The transplantability and metastatic rate of two specimen groups (primary and metastatic lesions) were analysed. alpha-Fetoprotein (AFP) was also determined in transplanted tumours by an immunohistochemical method. Orthotopic growth was observed in 14 of 30 transplanted specimens and formation of metastases in 7 cases, which exhibited the variety of clinical behaviours seen in patients with HCC. These behaviours included local growth, regional invasion, spontaneous intrahepatic, lymph node and lung metastasis and peritoneal seeding. In two groups the growth rate of metastatic lesions following implantation was clearly higher than that of primary tumours. Chromosome analysis from locally growing tumours confirmed their morphologically human origin. An immunohistochemical study showed that implanted tumours originating from AFP-positive specimens maintained AFP expression. These results indicated that the animal models should prove valuable for developing new treatment modalities and studying the mechanism of metastasis of human HCC.

Inhibitory effect of the angiogenesis inhibitor TNP-470 on tumor growth and metastasis in nude mice bearing human hepatocellular carcinoma.

The antitumor and anti-metastatic effects of a potent angiogenesis inhibitor, O-(chloroacetyl-carbamoyl)fumagillol (TNP-470), was investigated in a highly metastatic model of human hepatocellular carcinoma-LCI-D20. Small pieces of LCI-D20 tumor tissue were implanted subcutaneously into the right axillary region of 24 nude mice; the mice were then randomized into two groups. To one group, TNP-470 30 mg/kg was given as a subcutaneous injection every other day from day 1 to day 15 and the mice were sacrificed on day 26. An antitumor effect of TNP-470 was clearly demonstrated by tumor weight (0.97 +/- 0.34 g compared to 2.04 +/- 0.34 g, P < 0.001) and alpha-Fetoprotein value (93 +/- 59 micrograms/L compared to 769 +/- 282 micrograms/L, P < 0.001). There was also an anti-metastatic effect of TNP-470. Lung metastases developed in only 1 of 12 mice in the treated group, while they developed in 6 of mice of the control group. No severe side-effect of TNP-470 was found in this study. In vitro study revealed that the purified hepatoma cells were insensitive to TNP-470 (the 50% inhibitory concentration was 43 micrograms/ml). These results suggest that the angiogenesis inhibitor TNP-470 has both strong antitumor and anti-metastatic effects on a human hepatocellular carcinoma model in nude mice.

Intensity-dependent nociceptive responses from presumed dopaminergic neurons of the substantia nigra, pars compacta in the rat and their modification by lateral habenula inputs.

The characteristics of nociceptive responses from presumed dopaminergic (DAergic) neurons in the SN were investigated in the anesthetized rat with extracellular recordings. 194 presumed DAergic neurons were recorded. A majority of these neurons (78%) were inhibited by intensive electrical stimulation performed at the tail (PNS) and 15% were excited. Both inhibitory and excitatory responses were intensity-dependent. Single shock stimulation of the lateral habenula (LHb) inhibited 89% of the tested DAergic neurons, most of which (83.8%) were also inhibited by PNS. LHb stimulation increased PNS-induced inhibition of DAergic neurons and electrical destruction of ipsilateral LHb depressed their nociceptive responses. Our results strongly suggest that DAergic neurons encode the nociceptive stimulation intensity and that the LHb shares a step in nociceptive projection to the SN.

Time-course of changes in firing rates and firing patterns of subthalamic nucleus neuronal activity after 6-OHDA-induced dopamine depletion in rats.

The subthalamic nucleus (STN) plays a key role in motor control. Disorganization of its neuronal activity is implicated in the manifestation of parkinsonian motor symptoms. The aim of the present work was to study the time-course of changes in the firing activity of STN neurons in a rat model of parkinsonism. Electrophysiological recordings were done in normal rats and four groups of rats at different time points after 6-hydroxydopamine (6-OHDA) microinjection into the pars compacta of substantia nigra (SNc). Results showed a significant decrease in firing rate during the first and second weeks post lesion (5.53+/-0.56 and 7.66+/-0.73 spikes/s, respectively) compared to normal rats (11.13+/-0.59 spikes/s). From the 3rd week after 6-OHDA injection the firing rates returned toward baseline, with an average of 9.71+/-0.51 spikes/s during the 3rd week and 11.13+/-0.71 spikes/s during the 4th week. With regard to firing pattern, the majority of STN cells (90%) discharged regularly or slightly irregularly in normal animals. Only 4% exhibited burst activity and 6% had mixed firing patterns. After SNc-lesion, the percentage of cells exhibiting burst and mixed patterns increased progressively from 35% during the first week to 56% at week 4 post-lesion. In sum, these experiments revealed that the firing rate of STN neurons was altered only transiently following nigral lesions, whereas a progressive and stable change in the firing pattern was observed up to 4 weeks post lesion, suggesting that the persistence of bursts firing more closely relates to the motor pathologies of this rat model of parkinsonism.

Overproduction of nitric oxide inhibits vascular reactivity in portal hypertensive rats.

AIM: To evaluate the relationship between nitric oxide (NO) and hyperdynamic circulatory status in portal hypertension. METHODS: Twenty male Sprague Dawley rats (weighing 200 ± 20 g) were randomized into two groups: portal hypertension group (n = 12) and sham-operated control group (n = 8). The portal hypertensive model was established by means of graded constriction of the portal vein. The concentrations of nitrite (NO2 (-)) in the portal vein and peripheral blood were measured by fluorometric assay to reflect NO levels. The reactivity of isolated abdominal aortic rings from rats with partial portal vein constriction and controls was determined by assessing response to administration of potassium chloride (KCl) (10-80 mmol/L) and phenylephrine (10(-9)-10(-4) mol/L) with or without preincubation with NO synthase inhibitor Nω-nitro-L-arginine (L-NNA). RESULTS: Serum concentrations of NO2 (-) in the portal vein blood (0.766 ± 0.097 µmol/L) and peripheral blood (0.687 ± 0.092 µmol/L) were elevated in portal hypertensive rats, as compared with the concentrations in controls (0.613 ± 0.084 µmol/L and 0.591 ± 0.045 µmol/L respectively, both P < 0.01). In addition, the rates of NO2 (-) in portal vein blood were markedly higher than those in peripheral blood (P < 0.05) in the portal hypertensive rats. Abdominal aortic rings from rats with portal vein constriction exhibited significantly impaired contractility to phenylephrine and KCl, as compared with the control rats. The EC50 values of KCl were markedly higher in the portal hypertensive rings (26.5 ± 0.9 mmol/L) than in the control rings (22.3 ± 1.7 mmol/L, P < 0.01), as were the EC50 values of phenylephrine (37.2 ± 0.4 nmol/L vs control rings: 28.1 ± 0.2 nmol/L, P < 0.01). After preincubation of rings with L-NNA, the difference in EC50 values between portal hypertensive and control rings was no longer statistically significant for either KCl (20.18 ± 0.8 mmol/L vs 19.4 ± 1.2 mmol/L, P > 0.05) or phenylephrine (22.4 ± 1.8 nmol/L vs 21.8 ± 1.4 nmol/L, P > 0.05). However, the maximal concentrations of KCl and phenylephrine for inducing contractions were still significantly lower in the portal hypertensive rings (1.08 ± 0.1 g and 1.43 ± 0.14 g) than in the control rings (1.21 ± 0.11 g and 1.72 ± 0.11 g respectively, both P < 0.05). Thus, addition of the NO synthase inhibitor L-NNA could partially restore contractile responses to KCl and phenylephrine in portal hypertensive rings. CONCLUSION: NO overproduction inhibits the vascular reactivity to vasoconstrictors, and it might be one of the main causes of vasodilatation and hyperdynamic circulatory status in portal hypertension.

Establishment of cell clones with different metastatic potential from the metastatic hepatocellular carcinoma cell line MHCC97.

AIM: To establish clone cells with different metastatic potential for the study of metastasis-related mechanisms. METHODS: Cloning procedure was performed on parental hepatocellular carcinoma (HCC) cell line MHCC97, and biological characteristics of the target clones selected by in vivo screening were studied. RESULTS: Two clones with high (MHCC97-H) and low (MHCC97-L) metastatic potential were isolated from the parent cell line. Compared with MHCC97-L, MHCC97-H had smaller cell size (average cell diameter 43 microm vs 50 microm) and faster in vitro and in vivo growth rate (tumor cell doubling time was 34.2h vs 60.0h). The main ranges of chromosomes were 55-58 in MHCC97-H and 57-62 in MHCC97-L. Boyden chamber in vitro invasion assay demonstrated that the number of penetrating cells through the artificial basement membrane was (37.5 +/- 11.0) cells/field for MHCC97-H vs (17.7 +/- 6.3)/field for MHCC97-L. The proportions of cells in G0-G1 phase, S phase, and G2-M phase for MHCC97-H/MHCC97-L were 0.56/0.65, 0.28/0.25 and 0.16/0.10, respectively, as measured by flow cytometry. The serum AFP levels in nude mice 5wk after orthotopic implantation of tumor tissue were (246 +/- 66) microg.L(-1) for MHCC97-H and (91 +/- 66) microg.L(-1) for MHCC97-L. The pulmonary metastatic rate was 100% (10/10) vs 40% (4/10). CONCLUSION: Two clones of the same genetic background but with different biological behaviors were established, which could be valuable models for investigation on HCC metastasis.

Effects of matrix metalloproteinase inhibitor BB-94 on liver cancer growth and metastasis in a patient-like orthotopic model LCI-D20.

BACKGROUND/AIMS: The aim of this study was to try to understand the effects of the synthetic matrix metalloproteinase inhibitor Batimastat (BB-94) on hepatocellular carcinoma (HCC). METHODOLOGY: An orthotopic metastatic human hepatocellular carcinoma in nude mice model (LCI-D20) was used to study primary tumor growth, local invasion and metastasis of HCC. MTT assay was used to study the effects of BB-94 on cytotoxin and proliferation of HCC cell line SMMC-7721 in vitro. A gelatine zymograph was used to study the expression of MMPs in the LCI-D20 tumor tissue. RESULTS: BB-94 can inhibit primary tumor growth, local invasion, intrahepatic and lung metastasis, as well as prolong survival. BB-94 did not affect the proliferation of HCC cells in vitro. LCI-D20 tumor tissue expresses MMP-2 and MMP-9. CONCLUSIONS: BB-94 has a cytostatic therapeutic effect on HCC.

Direct vision controlled gastric coronary vein embolization for the treatment of portal hypertension.

Complications of gastric mucosal bleeding and ectopic embolism occurred in gastric coronary embolization under direct vision in treating hemorrhage from ruptured esophageal varices though it has been widely used with satisfactory results. 40 patients with portal hypertension were treated by splenectomy and gastric coronary vein embolization under direct vision in this hospital. On the basis of Liu's operative method, 20 of the 40 patients underwent controlled embolization of the gastric coronary vein with satisfactory results. The technic not only occluded the predicted bleeding sites of the veins at the esophageal and gastric fundic regions but also blocked its communication with surrounding veins. Thus serious complications were reduced or prevented. The effectiveness of devascularization derived from the technic in question, the detailed maneuver of the procedure, and prevention of complications are discussed.

[Effects of the stimulation of the subthalamic nucleus in Parkinson disease]. / Effets de la stimulation du noyau sous-thalamique dans la maladie de Parkinson.

In Parkinson's disease, experimental studies favour a neuronal hyperactivity of the subthalamic nucleus. We carried out a subthalamic nucleus electrical stimulation in a patient aged 51, suffering for 8 years from a severe akineto-rigid form of Parkinson's disease, complicated with an on-off effect. Stereotaxic surgery was done under local anaesthesia on one side. Within the theoretical target, a 130 Hz stimulation induced akinesia alleviation mainly on the contralateral limbs. No abnormal movement was noticed. Then a long-term quadripolar DBS Medtronic electrode was inserted in that area. The study of the effects of chronic stimulation is in progress to determine the best temporal and electrical stimulation variables.

[Synthesis and cardiovascular activities of peptidyl dopamine derivatives].

Amino acids and small peptides with different steric configurations and lipophilicities were appended to dopamine. Eighteen compounds have been synthesized. The attachment of D-amino acids or N-methyl amino acids onto the dopamine molecule caused a marked decrease in cardiovascular activity by intravenous injection, while the introduction of lipophilic amino acids caused a marked increase in myocardial contractility and blood pressure in anesthetized dogs. The durations of action were also prolonged.

[A technic of limited gastric coronary vein embolization under direct vision for treatment of portal hypertension].

Venous embolism of the gastro-cardiac area for the purpose of controlling hemorrhage, as suggested at Liu Xiougong in 1984, was adopted widely by some institutes in our country with a satisfactory outcome although some complications did happen. Forty cases of portal hypertension was treated in this institute since May 1985 with coronary vein embolism plus splenectomy under direct vision. Based on modified Liu's technique and animal experiment, the authors practiced limited gastric coronary vein embolism in 20 cases with a satisfactory result. This procedure may not only block the veins where bleeding may incidentally occur, but also cut off the communications between the veins of the lower esophagus, the fundus of the stomach and the adjacent venous system to minimize the possibility of postoperative complications. The mechanism of blockade and technique of this procedure were described and the ways to prevent complications presented in detail.

Simultaneous recording of spontaneous activities and nociceptive responses from neurons in the pars compacta of substantia nigra and in the lateral habenula.

Using simultaneous extracellular single-unit recording in the pars compacta of the substantia nigra and in the lateral habenula of rats, 45 pairs of neurons responding to peripheral nociceptive stimulation were recorded. In 41 of these pairs, nigral dopaminergic neurons were inhibited by peripheral nociceptive stimulation, while lateral habenula neurons were excited. Moreover, in 14 pairs, when sweeps were triggered randomly by spontaneous spikes from lateral habenula neurons the spontaneous firing rate of the dopaminergic neurons during the first 250 ms after the sweep was much lower than rates after this time period. In this case, the sweep was often triggered by burst-firing of lateral habenula neurons. Our results indicate a cross-correlation between the spontaneous activities of these two nuclei, suggesting that the excitation of lateral habenula neurons induced by peripheral nociceptive stimulation might be directly responsible for inhibition of nigral dopaminergic neurons.

Structure of the nucleocapsid protein gene of rice yellow stunt rhabdovirus.

The complete nucleotide sequence of the N protein gene of rice yellow stunt rhabdovirus (RYSV) was determined by sequencing of cDNA clones derived from the viral genomic RNA. The 3' end of the N gene (messenger sense) was defined by sequence analysis of cDNA clones generated from the N protein mRNA by 3'RACE. The 5' end sequence of the gene was putatively assigned as 5'-AACAC-3'; this sequence is found in the presumed 3' leader/N gene junction region. The mRNA encoding the RYSV N protein is 1714 nt comprising a 15-nt untranslated 5' leader sequence followed by an open reading frame (ORF) of 1563 nt and a 136-nt untranslated 3' region. The calculated molecular mass of the N protein encoded by the ORF is 58,400 Da, which is larger in size than N proteins of other rhabdoviruses. Amino acid composition analysis shows that the RYSV N protein is rather basic with a predicted isoelectric point of 10.04; indeed, a large highly basic region could be found at the carboxy terminal portion of the protein. Amino acid sequence comparison between N proteins of RYSV and sonchus yellow net virus, both of which belong to the same genus Nucleorhabdovirus, revealed an overall 30% identity, with three relatively conserved blocks of 14-20 amino acid residues. Moreover, the hydropathy profiles of the two proteins are generally similar. The structural similarities between the N protein of RYSV and that of lettuce necrotic yellows virus, the type member of the genus Cytorhabdovirus, and those of animal rhabdoviruses, are less significant. Nucleotide sequence determination of 5' and 3' regions flanking the RYSV N gene identified a 14-nt common sequence that is very similar to the consensus gene junction sequences of other plant and animal rhabdoviruses.