PubMed Health⌕ Search

Biomedical subjects

Jian-Jun Wang

Publications and source records attributed to Jian-Jun Wang.

At least 19 recordsLinked to original sources

Cerebellar modulation of feeding-related neurons in rat dorsomedial hypothalamic nucleus.

Cerebellum has newly been implicated in many more nonsomatic functions other than motor control. Previous studies indicate that the cerebellum is involved in feeding regulation and that the gastric vagal nerves transmit short-term meal-related visceral signals, including cholecystokinin (CCK), into the hypothalamus. Recently, the dorsomedial hypothalamic nucleus (DMN) has been thought to play an important role in feeding control. Here we investigate whether the inputs from cerebellar interpositus nucleus (IN) can reach and converge onto single DMN neurons with some feeding-related visceral signals, including gastric vagal inputs, CCK, and blood glucose, whose concentration is closely linked to food intake. Among the 259 DMN neurons recorded, 120 (46.3%) and 169 (65.3%) responded to the cerebellar IN and gastric vagal stimulations, respectively. Within the 120 DMN neurons responsive to the cerebellar IN stimulation, 98 (81.7%) also responded to the gastric vagal stimulus, and a summation of the responses was observed further (n = 20), suggesting a convergence and interaction of cerebellar and gastric vagal inputs on the cells. Moreover, among the 98 cells receiving convergent inputs from cerebellar IN and gastric vagal nerves, 69 (70.4%) were identified to be glycemia sensitive, and 22 (68.8%) of the 32 tested neurons were also sensitive to systemic CCK. These results demonstrate that the DMN integrates somatic information forwarded by the cerebellar IN and visceral signals related to food intake, including gastric vagal, CCK and glycemia, and electrophysiologically reveal a novel cerebellohypothalamic IN-DMN pathway through which the cerebellum may actively participate in short-term feeding regulation.

Action Potentials↗

Immunoregulatory role of endogenous catecholamines synthesized by immune cells.

It has been well known that catecholamines (CAs) in the body, including norepinephrine (NE), epinephrine (E) and dopamine (DA), are synthesized and secreted by neurons and endocrine cells and mainly modulate visceral activities such as cardiovascular, respiratory and digestive functions. The studies over the past nearly 30 years have shown that CAs can also regulate immune function. The immunomodulation of CAs is generally considered as a role mediating the regulation of nervous and endocrine systems. However, recent studies reveal that immune cells can also synthesize CAs, which is an update of traditional concept. A classical metabolic pathway of CAs shared by the nervous and endocrine systems is present in the immune cells, i.e., the immunocytes have the enzymes for synthesis of CAs [e.g. tyrosine hydroxylase (TH)] and the enzymes for degradation of CAs [e.g. monoamine oxidase (MAO) and catechol-O-methyl transferase (COMT)]. The endogenous CAs synthesized by immune cells can regulate many immune functions, including cellular proliferation, differentiation, apoptosis and cytokine production. These roles of the endogenous CAs may be mediated by an autocrine/paracrine pathway via relevant receptors on the immunocytes and intracellular cAMP. Intracellular oxidative mechanism may also be involved in immunoregulation of endogenous CAs in immune cells. In addition, some metabolic abnormalities of CAs in the immune cells probably induce some autoimmune diseases, such as multiple sclerosis (MS) and rheumatoid arthritis. These findings not only provide evidence for the new concept that the immune system is possible to become the third CA system other than the nervous and endocrine systems, but also extend our comprehension on functional significance of the endogenous CAs synthesized by immune cells.

Animals↗

[The application of diminished criminal responsibility rating scale to schizophrenia offenders].

OBJECTIVE: To explore the feasibility of Diminished Criminal Responsibility Rating Scale(DCRRS) to schizophrenia offenders. METHODS: The DCRRS were used respectively to 325 cases of schizophrenia offender which were divided into three groups according to the degree of criminal responsibility. RESULTS: There were significant differences in rating score among three groups (mild group 21.16 +/- 4.17, moderate group 25.87 +/- 5.43, major group 29.35 +/- 4.60), and all items have good correlation with the total score of the scale. 6 factors were extracted by the factor analysis, and their cumulative squared loadings is 68.485%. CONCLUSION: The diminished criminal responsibility in schizophrenia offenders could be divided into three grades.

Adolescent↗

Cerebellar interposed nucleus lesions suppress lymphocyte function in rats.

We previously reported that the cerebellar fastigial nucleus, output nucleus of the spinocerebellum, modulates lymphocyte function. To further explore the role of the cerebellum in neuroimmunomodulation, we here lesioned bilaterally the cerebellar interposed nuclei (IN) of rats with kainic acid (KA) injections. On days 8, 16 and 32 after IN lesions, lymphocyte percentage in peripheral white blood cells was examined. Furthermore, proliferation of lymphocytes from mesenteric lymph nodes induced by concanavalin A, sheep red blood cell-specific IgM antibody in the serum and cytotoxicity of natural killer cells from spleen against YAC-1 cells were measured by methyl-thiazole-tetrazolium assay, enzyme-linked immunosorbent assay and flow cytometric assay, respectively. On days 8, 16 and 32 after KA injection in the IN, the lymphocyte percentage in the peripheral white blood cells was notably diminished with respect to control rats injected with saline in the IN. Concanavalin A-induced lymphocyte proliferation, serum sheep red blood cell-specific IgM antibody and natural killer cell toxicity of the IN-lesioned rats were significantly attenuated with respect to IN-saline control rats at all the post-lesion time points. The findings reveal that KA-induced neuronal loss in the IN of both sides exerts an inhibitory effect on number and functions of T, B and natural killer lymphocytes, and indicate that the cerebellar IN participates in regulating immune function. Thus, the data suggest that the cerebellum may be an important brain area for neuroimmunomodulation, besides its well-known role in motor control.

Animals↗

Doxycycline-regulated co-expression of GDNF and TH in PC12 cells.

Current gene therapy models for Parkinson's disease (PD) have adapted two treatment strategies. One is to restore dopamine (DA) production by delivering the genes of DA-synthesizing enzymes such as tyrosine hydroxylase (TH) to the striatum to relieve motor symptoms of PD. Another is to block or slow down progressive degenerative changes by delivering neurotrophic factors such as glial cell line-derived neurotrophic factor (GDNF) to protect the remained neurons. To test the assumption that the combination of the two strategies may have a compound or synergistic effect, we had constructed tetracycline-inducible (tet-off) AAV vector carrying GDNF and TH. After co-transfection of PC12 cells with this vector and the inducer plasmid, the expression of GDNF and TH protected these cells from 1-methyl-4-phenyl-pyridinium-induced injury, and significantly increased the content of dopamine in GDNF/TH-expressing cells compared with the control. Furthermore, mRNA expression of GDNF and TH could be effectively and reversibly regulated by doxycycline (Dox) and the function of GDNF and TH could be repressed by Dox. These results suggest that the tet-off AAV vector carrying GDNF and TH may be a useful tool for gene therapy in the treatment of PD.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗

The cerebellar-hypothalamic circuits: potential pathways underlying cerebellar involvement in somatic-visceral integration.

The cerebellum has been considered only as a classical subcortical center for motor control. However, accumulating experimental and clinical evidences have revealed that the cerebellum also plays an important role in cognition, for instance, in learning and memory, as well as in emotional behavior and in nonsomatic activities, such as visceral and immunological responses. Although it is not yet clear through which pathways such cerebellar nonsomatic functions are mediated, the direct bidirectional connections between the cerebellum and the hypothalamus, a high autonomic center, have recently been demonstrated in a series of neuroanatomical investigations on a variety of mammals and indicated to be potential pathways underlying the cerebellar autonomic modulation. The direct hypothalamocerebellar projections originate from the widespread hypothalamic nuclei/areas and terminate in both the cerebellar cortex as multilayered fibers and the cerebellar nuclei. Immunohistochemistry studies have offered fairly convincing evidence that some of these projecting fibers are histaminergic. It has been suggested that through their excitatory effects on cerebellar cortical and nuclear cells mediated by metabotropic histamine H(2) and/or H(1) receptors, the hypothalamocerebellar histaminergic fibers participate in cerebellar modulation of somatic motor as well as non-motor responses. On the other hand, the direct cerebellohypothalamic projections arise from all cerebellar nuclei (fastigial, anterior and posterior interpositus, and dentate nuclei) and reach almost all hypothalamic nuclei/areas. Neurophysiological and neuroimaging studies have demonstrated that these connections may be involved in feeding, cardiovascular, osmotic, respiratory, micturition, immune, emotion, and other nonsomatic regulation. These observations provide support for the hypothesis that the cerebellum is an essential modulator and coordinator for integrating motor, visceral and behavioral responses, and that such somatic-visceral integration through the cerebellar circuitry may be fulfilled by means of the cerebellar-hypothalamic circuits.

Animals↗

The role of secretin in the cerebellum.

There is increasing interest in the role played by secretin in the central nervous system. Recent evidence suggests that this peptide is widely expressed in the brain but some areas, notably the cerebellum, show a prominent expression of the peptide and its specific receptor. In this article we summarize our current understanding of the expression pattern and action of secretin in the cerebellum. We discuss the findings supporting the endogenous release of this peptide from Purkinje neurons and its role as a retrograde messenger modulating GABAergic synaptic transmission via multiple mechanisms. In addition, we would like to propose other possible, but still to be confirmed, functions of secretin in the cerebellum..

Animals↗

[The leakage radiation testing method for mammographic X-ray equipments].

This article introduces a new testing method for mammographic x-ray equipments. The films placed around the x-ray tube assembly are exposured to find the location of leakage radiation and then the accurate testing for the leakage radiation of the mammographic x-ray equipment is carried out with a radiation dosimeter.

Equipment Design↗

[Space-time dependent variances of ammonia and phosphorus flux on sediment-water interface in Lake Taihu].

Monthly research of ammonia and phosphorus fluxes in water-sediment interface in East Lake Taihu (ELT, macrophyte dominated) and Meiliang Bay (MB, algae dominated) was processed with intact sediment cores' incubation and pore water diffusive model. The ammonia and phosphorus fluxes calculated with intact sediment cores' incubation (F(i)) showed discrepancy in different lake zones with different ecotype. The yearly average fluxes of ammonia and dissolved phosphorus in ELT were (44.9 +/- 21.9) mg x (m2 x d)(-1) (Mean +/- SD) and (2.06 +/- 1.71) mg x (m2 x d)(-1); and (16.2 +/- 12.0) mg x (m2 x d)(-1) and (0.53 +/- 0.52) mg x (m2 x d)(-1) in MB. The molecular diffusive fluxes (F(m)) of the two lake zones showed the same pattern, but the absolute value difference may as high as an order of magnitudes. So this molecular diffusive model cannot be used to evaluate the nutrients fluxes in sediment-water interface in Lake Taihu, a lake vulnerable with wind and wave affection and benthic bio-disturbation. Compared with the two lake zones with different ecotypes, macrophyte dominated one had higher nutrients fluxes than the algae one. ELT had higher bio-disturbation, which was revealed by the F(i)/F(m) ratio. When the dissolved oxygen (DO) remained in high concentration, known as aerobic condition, the nutrients' fluxes were not correlated with the DO. Similarly, the fluxes were not correlated with the nutrients' concentration of the overlying water at the existing condition. The discrepancy between higher nutrients' fluxes and lower nutrients loading in ELT suggested the higher particulate settlement rate and assimilate rate promoted by the macrophyte. This is the important theoretical basis of rebuilding the healthy ecosystems with restoring the water plants.

Ammonia↗

Role of GABAB receptors in GABA and baclofen-induced inhibition of adult rat cerebellar interpositus nucleus neurons in vitro.

Previous studies suggested that the postsynaptic GABA(B) receptors of deep cerebellar nuclear neurons of adult rats were not activated by selective GABA(B) receptor agonist baclofen or endogenous GABA released by cerebellar cortical Purkinje cells, although the receptors have been demonstrated to exist in the deep cerebellar nuclei. In this study, cerebellar slices of adult rats were prepared for testing effects of GABA, baclofen and muscimol (selective GABA(A) receptor agonist) on cerebellar interpositus nucleus (IN) neurons. Perfusing slices with GABA (10-1000 microM), baclofen (1-30 microM) and muscimol (1-100 microM) respectively produced a dose-dependent inhibitory response on the IN neurons (n = 39, 62 and 50), which was not blocked by low-Ca(2+)/high-Mg(2+) medium (n = 5, 6 and 6), supporting a direct postsynaptic action of these GABAergic agonists. Moreover, both selective GABA(B) receptor antagonist CGP35348 and selective GABA(A) receptor antagonist bicuculline were capable of partially blocking the inhibitory response of IN neurons to GABA (n = 14 and 11), suggesting that the GABA-induced inhibition may contain two components, a GABA(B) receptors-mediated component and a GABA(A) receptors-mediated one. Further experiments revealed that not only muscimol (n = 50) but also baclofen (n = 62) suppressed IN cells' activity. The baclofen-induced inhibition was selectively blocked by CGP35348 (n = 12) but not by bicuculline (n = 8), whereas the muscimol-induced inhibition was selectively antagonized by bicuculline (n = 8) instead of CGP35348 (n = 9). These results indicate that GABA(B) receptors in the IN neurons can be activated not only by GABA but also by baclofen, suggesting that besides GABA(A) receptors, GABA(B) receptors may also be involved in mediating the inhibitory effect of GABA on cerebellar IN neurons of adult rats.

Action Potentials↗

Excitatory effect of histamine on neuronal activity of rat globus pallidus by activation of H2 receptors in vitro.

Previous studies have revealed distribution of histaminergic fibers and presence of histamine receptors in globus pallidus (GP). In this study, the brain slice preparation of adult rats was used to examine the effect of histamine on the spontaneous unitary discharge of GP neurons and the underlying receptor mechanism. Ninety-five GP neurons were extracellularly recorded from 42 slices containing the GP, of which 87 (91.6%) were excited by the stimulation of histamine. The histamine-induced excitation was concentration-dependent and persisted in low Ca2+/high Mg2+ medium (n = 9), demonstrating that the action of histamine on the GP neurons was postsynaptic. The excitatory effect of histamine on the GP neurons was not blocked by selective histamine H1 receptor antagonist triprolidine (n = 16) or chlorpheniramine (n = 6), but was effectively suppressed by ranitidine, a highly selective histamine H2 receptor antagonist (n = 21). On the other hand, highly selective histamine H2 receptor agonist dimaprit mimicked the excitatory effect of histamine on the GP neurons (n = 23), while histamine H1 receptor agonists, including 2-pyridylethylamine (n = 22), 2-thiazolyethylamine (n = 9) and betahistine (n = 9), did not cause GP neurons any response. The dimaprit-induced GP neuronal excitation was effectively antagonized by selective histamine H2 receptor antagonist ranitidine (n = 14) but not influenced by selective histamine H1 receptor antagonist triprolidine (n = 12). Moreover, adenylate cyclase (AC) activator forskolin (n = 7) was observed to evoke GP neurons an excitatory response, whereas the histamine-induced excitation was effectively reduced by H-89 (n = 9), a selective and potent inhibitor of protein kinase A (PK(A)). Finally, it was noted that neurons of both subdivisions of the GP, the internal (GPi, n = 35) and external (GPe, n = 60) segment, showed no differences in their responses to stimulations of the tested histaminergic reagents. These results demonstrated that histamine excited GP (including GPi and GPe) neurons via histamine H2 receptors and H2 receptors linked intracellular G-protein-AC-PK(A) signaling pathway, suggesting that the hypothalamic histaminergic afferent fibers innervating GP may play an important modulatory role in motor control through its excitatory effect on GP neurons.

Action Potentials↗

Tissue distribution of a plasmid DNA containing epitopes of foot-and-mouth disease virus in mice.

It is known that only the minority of plasmid DNAs effect a cure or prevention after intramuscular injection into host. But what is the fate of the majority? And indeed how many of the injected DNAs work? Till now, little is known about it. To answer these questions, two methods including PCR and autoradiography were used in distribution study in mice that had received a single muscular inoculation of plasmid DNA containing antigenic epitopes of foot-and-mouth disease virus. The results showed that the plasmid DNAs were distributed by blood circulation and degraded soon. The degradation ratio of super coiled plasmid DNA was 20.9% in 10 min, 34.1% in 1h, 86.8% in 1 day and 97.8% in 1 week in sera in vivo. And over a half of the whole were output in urine and faeces. The rest resided most in muscles as 'antigen pool', next in immune organs, kidney, liver, heart, lung and little in brain or gonad. About 40% or 0.5% of total plasmid DNAs, inferring to be effective, resided in muscles or immune organs, respectively. Collective results suggested that 'nude' DNA, as water injection, was characterized as quick absorbent, extensive distribution, but low utilization rate. Finally, the immune mechanism for the DNA vaccine was discussed.

Animals↗

The methods for determining the purity and in vitro or in vivo activity of recombinant human endostatin.

In order to establish the methods of high-performance liquid chromatography (HPLC) for determining the purity of recombinant human endostatin (rhEndostatin) and in vitro or in vivo activity of rhEndostatin, two columns were firstly used in HPLC analysis for determining the purity of rhEndostatin, including Waters Symmetry 300C4 (4.6 mm x 250 mm, 5 microm) and the Superdex75 HR 10/30. Cell lines, bovine capillary endothelial cells (BCEs) or human umbilical vein endothelial cells (HUVECs) expression human vascular endothelial growth factor (hVEGF) were used in method MTT or LDH as substrate, respectively. The bioactivity in vivo was assayed by the anti-tumor proliferation rate in H22 liver tumor-bearing mice. The results showed that the retention time of rhEndostatin sample was stable at 19.066 min or 11.506 min in reverse phase HPLC (RP-HPLC) or gel filtering HPLC (GF-HPLC). The stableness, repeat and recovery rates were over 99% in both methods and there was no statistical difference between these two methods (p > 0.05). In nonserum culture medium, rhEndostatin can sensitively and stably inhibit the proliferation of the HUVEC cells that were transfected with plasmid encoding hVEGF. LDH substrate methods is the most sensitive and stable method. The anti-tumor activity in H22 tumor-bearing mice was also highly repeatable and had an inhibition rate over 50% at 20 mg kg(-1) weight. As a conclusion, the RP-HPLC and GF-HPLC set up in this paper are highly repeatable, accurate and sensitive for detecting the purity of rhEndostatin. The bioactivity of rhEndostatin can be measured through detection the proliferation-inhibition on HUVECs transfectants with hVEGF in vitro or on H22 liver tumor in vivo.

Animals↗

Effect of lesions of cerebellar fastigial nuclei on lymphocyte functions of rats.

The cerebellum, probably owing to its traditional concept limited to motor control, is less well studied in immunoregulation. To obtain more comprehension and knowledge on cerebellar functions, we investigated effect of cerebellar fastigial nucleus (FN), an output nucleus of the spinocerebellum, on lymphocyte functions, and explored central and peripheral pathways involved in the effect. Kainic acid (KA) was microinjected into bilateral FN of rats (0.4 microg KA in 0.4 microl saline for each side) to destroy neurons of the nuclei. On days 8, 16 and 32 following the FN lesions, methyl-thiazole-tetrazolium (MTT) assay and flow cytometry were used to measure proliferation of concanavalin A (Con A)-induced lymphocytes and cytotoxicity of natural killer (NK) cells against YAC-1 cells, respectively. Meanwhile, glutamate and monoamine neurotransmitters, including norepinephrine (NE), dopamine (DA) and 5-hydroxytryptamine (5-HT), in the hypothalamus and the spleen were determined by means of high-performance liquid chromatography (HPLC) assay. Adrenocorticotropic hormone (ACTH) and cortisol in the plasma were also detected respectively by radioimmunoassay and chemiluminescent immunoassay after the FN lesions. We found that the Con A-induced lymphocyte proliferation and the NK cell cytotoxicity were both significantly enhanced on days 8, 16 and 32 following the effective lesions of the bilateral FN in comparison with those of matching control rats microinjected with saline in their FN. Contents of glutamate and NE, not DA and 5-HT, in the hypothalamus, and concentration of NE, not DA, in the spleen were all remarkably reduced on the 16th day following the FN lesions, when both the T lymphocyte proliferation and the NK cell cytotoxicity were dramatically increased. However, levels of ACTH and cortisol in the plasma had no notable differences between FN lesion rats and FN saline ones when the enhanced T and NK cell functions occurred. These findings reveal that the cerebellar FN participates in the modulation of lymphocyte functions and that the hypothalamus and sympathetic nerves innervating lymphoid organs are involved in this neuroimmunomodulation. Thus, a possible central and peripheral pathway for the spinocerebellum to regulate lymphocyte functions is suggested, i.e. cerebellum-hypothalamus-sympathetic nerves-lymphocytes, while the functional axis of hypothalamus-pituitary-adrenal gland may not contribute to mediation of the spinocerebellar immunomodulation.

Animals↗

The development and identification of constructing tissue engineered bone by seeding osteoblasts from differentiated rat marrow stromal stem cells onto three-dimensional porous nano-hydroxylapatite bone matrix in vitro.

The purposes of this study were to develop a new cultural method for the rat bone marrow stromal cells (MSCs) to differentiate into osteoblasts well in vitro, and to investigate the feasibility of using MSCs as seed cells and three-dimensional porous nano-hydroxylapatite as scaffolds for constructing tissue-engineered bone. MSCs of rats were isolated, cultured, induced to differentiate into osteoblasts, and then observed with inverted microscopy. Histochemical staining and radio-immunological analysis were applied for identifying MSCs. Whereafter MSCs were seeded onto three-dimensional porous nano-hydroxylapatite scaffolds, and scanning electron microscopy was applied to evaluate their growth on scaffolds. Results showed that MSCs were typical fibroblast-like and possessed a better proliferating capability; the activity of alkaline phosphatase (ALP) and the secretion of osteocalcin of MSCs were produced gradually and increased continuously; the cells seeded on three-dimensional porous nano-hydroxylapatite scaffolds adhered, proliferated and differentiated well. These results demonstrated that the new improved culture method had the advantages of short isolating time, less risk of contamination and higher efficiency and accordingly was conducive to MSCs proliferating and differentiating into osteoblasts, and that it was advantageous to constructing tissue-engineered bone using MSCs as seed cells and three-dimensional porous nano-hydroxylapatite as scaffolds.

Animals↗

Neurons in the rat lateral hypothalamic area integrate information from the gastric vagal nerves and the cerebellar interpositus nucleus.

Previous investigations have demonstrated that the neuronal activity in the lateral hypothalamic area (LHA) is respectively modulated by afferent inputs from the gastric vagal nerves innervating the upper gastrointestinal tract, as well as the cerebellar interpositus nucleus (IN). The aim of this study was to examine whether the gastric vagal and cerebellar IN inputs converge onto single LHA neurons in rats, especially those sensitive to glycemia. Of the 114 LHA neurons recorded, 60 (52.6%) and 51 (44.7%) responded to gastric vagal and cerebellar IN stimulation, respectively. Of the 60 LHA neurons responsive to gastric vagal stimulation, 30 also responded to the cerebellar IN stimulus, indicating a convergence of gastric vagal and cerebellar inputs onto single hypothalamic cells. When the gastric vagal nerves and cerebellar IN were stimulated simultaneously, a summation of the responses was observed in all 6 neurons tested. Moreover, of 24 neurons that responded to both the gastric vagal and cerebellar IN stimuli, 15 (62.5%) were identified as glycemia-sensitive. These results demonstrate that the visceral information transmitted by the gastric vagal nerves and the somatic information forwarded by the cerebellar IN converge onto single LHA neurons, especially those sensitive to glycemia. The findings also suggest that integration of somatic-visceral responses related to short-term feeding regulation may take place in the LHA.

Animals↗

[Identification and analysis of a mouse gene homologous to human hepatitis B virus pre-S1 protein-binding protein using the bioinformatics method].

OBJECTIVE: To clone and identify the mouse gene homologous to human hepatitis B virus (HBV) pre-S1 protein-binding protein (PS1BP). METHODS: The human PS1BP cDNA sequence was used as the reference sequence to search homologous mouse cDNA sequence from GenBank established by National Center for Biotechnology (NCBI), National Institute of Health (NIH), for its homologous cDNA sequences of mouse by BLASTn tool. The characteristics of mouse PS1BP protein primary structure were predicted by online software. Finally the genomic DNA structure of mouse PS1BP was deduced and compared. RESULTS: The mouse PS1BP was identified and consisted of 1455 nt, coding a protein of 484 aa. The identity of human and mouse PS1BP protein is 84.92% (411/484). The genomic DNA of mouse PS1BP consisted of 3 exons and 2 introns. CONCLUSION: The identification and characterization of mouse PS1BP cDNA and genomic DNA pave a way for further study of their structures and functions.

Amino Acid Sequence↗