AIMTo study the determination of dopamine (DA) in the presence of ascorbic acid (AA) using poly (isonicotinic acid) film modified electrode.

METHODSThe cyclic voltammetry and differential pulse voltammetry were used to study the electrochemical behavior of DA at the poly (isonicotinic acid) film modified electrode.

RESULTSThe poly (isonicotinic acid) film modified electrode showed an electrocatalytic effect on DA, and shifted the oxidation of AA to negative potential. The difference between the oxidation potentials of DA and AA was 204 mV, thus, AA did not interfere with the determination of DA. The linear range between the anodic currents and DA concentration was: 1.0 x 10(-7)-2.0 x 10(-5) and 2.0 x 10(-5)-1.0 x 10(-4) mol.L-1. The detection limit was 8.0 x 10(-9) mol.L-1.

CONCLUSIONThe useful life period of the modified electrode is three weeks at least. The modified electrode can be used to the determination of DA in the sample.

Ascorbic Acid ; analysis ; Dopamine ; analysis ; Electrochemistry ; methods ; Electrodes ; Isonicotinic Acids ; chemistry

Sodium dodecyl benzenesulfonate (SDBS) self-assembled monolayers in situ modified electrode (SDBS/CPE) was prepared. The electrochemical behaviors of dopamine (DA) on SDBS/CPE were studied. Electrochemical behaviors and kinetic parameters of DA were investigated at SDBS/CPE by cyclic voltammetry (CV), chronoamperometry (CA) and chronocoulometry (CC). The changes of the oxidation peak currents with concentration of DA were examined by square wave voltametry (SWV). The difference of peak potential at CPB/CPE was less than 149 mV comparing with that at CPE. The charge transfer coefficient alpha, diffusion coefficient D and the apparent reaction rate constant k(f) are 0.61, 3.6 x 10(-5) cm2 x s(-1) and 4.2 x 10(-3) cm x s(-1), respectively. The oxidation peak currents of DA versus its concentration have a good linear relationship in the concentration range of 2.0 x 10(-6)-1.0 x 10(-3) mol x L(-1) with the correlation coefficient of 0.9979 and the detection limit of 9.0 x 10(-7) mol x L(-1) by square wave voltammetry (SWV) response. The modified electrode showed an excellent electrocatalytic activity for the DA electrochemical oxidation. The method can be applied in the determination of DA in injection samples with the satisfactory results.
Benzenesulfonates ; chemistry ; Catalysis ; Dopamine ; analysis ; chemistry ; Electrochemistry ; methods ; Electrodes ; Oxidation-Reduction

Amisulpride, a substituted benzamide derivative, is a newer atypical antipsychotics. It mainly blocks presynaptic dopamine D2/D3 autoreceptors which is preferentially located in prefrontal area and blocks postsynaptic dopamine D2/D3 receptors in the limbic system. By these mechanism, amisulpride can improve both negative and positive symptoms. In addition to these action, its property of fast dissociation (Koff) and selectivity to D2/D3 receptors can explain more favorable side effects profiles. A lot of studies showed that amisulpride has equivalent or better efficacy and safety to other atypical antipsychotics. Meta-analysis studies is very informative because it contains many cases of previous studies. So we reviewed some meta-analysis studies which compared amisulpride with placebo or other antipsychotics. On positive symptoms of acute schizophrenia, the most pooled analyses of amisulpride have shown to be equally effective with conventional antispychotics. One meta-analysis study have shown that amisulpride is more effective than conventional drugs. On primary negative symptoms, amisulpride is only agents which is investigated for the efficacy in patients with predominantly negative symptoms. as a results of meta-analysis, amisulpride was shown to be more effective than placebo in primary negative symptoms and have a trend of superiority to conventional agents. The safety and tolerability of amisulpride was equal to or better than other atypical drugs on pooled analysis. The drop out rate was also more favorable than conventional antipsychotics. In Summary, amisulpride showed efficacy similar to that of other atypical antipsychotics in reducing positive symptoms. Moreover, its better properties for negative and affective symptoms, and favorable side effects profiles provides another alternative for treatment of schizophrenia. These results show that amisulpride is a favorable `atypical' antipsychotics, and that 5-HT2/D2 antagonism is not only mechanism of `atypicality'.
Affective Symptoms ; Antipsychotic Agents ; Autoreceptors ; Dopamine ; Humans ; Limbic System ; Meta-Analysis as Topic ; Schizophrenia

BACKGROUND: The basal ganglia plays a major role in regulating motor, cognitive and emotional functions. In addition, it has been proposed that the functions of the basal ganglia is also related to control of sensory discrimination and sensorimotor integration. One possible way to test this hypothesis would be to investigate sensory functions in patients with various diseases affecting basal ganglia functions. Since idiopathic Parkinson's disease (IPD) is caused by selective impairment of basal ganglia functions, it could be a good model for this purpose. METHODS: We measured the grating resolution threshold (GRT) using the JVP (Johnson-Van Boven-Phillips) dome in 52 patients with IPD and 25 age-matched healthy controls. Statistical analysis employed unpaired t-test, paired t-test and simple regression analysis. P-values less than 0.05 were considered as significant. RESULTS: Patients showed significantly higher GRT than controls (3.07 +/- 0.74 vs 2.03 +/- 0.80; p<0.05). In patients, the mean GRT was not different between symptomatically dominant and non-dominant hands (3.10 +/- 0.95 vs 2.93 +/- 0.82). In the patients with hemiparkinsonism, GRT was also significantly higher in asymptomatic hands compared with controls (3.00 +/- 0.71 vs 2.03 +/- 0.80; p<0.05). The severity of sensory dysfunction in patients was not correlated with symptom duration or to symptom severity, measured by the modified Columbia rating scale (MCRS). CONCLUSIONS: The present results demonstrate that spatial discrimination is impaired in IPD, suggesting the basal ganglia plays a role in sensory regulation.
Basal Ganglia ; Discrimination (Psychology)* ; Dopamine ; Hand ; Humans ; Parkinson Disease* ; Regression Analysis ; Sensation

The self-made high sensitivity and selectivity micro-biosensor was applied to monitor the change of dopamine in cerebral nucleus in rats in vivo. The micro-biosensor was prepared and used to detect dopamine level in vitro and monitor the dynamic change of dopamine in different cerebral nucleus in vivo. The results showed the lowest concentration of dopamine that could be detected by the biosensor was 32.5 nmol/L. Its positive peak was significantly different from that of AA, 5-HTP and E. The biosensor could keep working for monitoring the dopamine concentration in the cerebral tissue for more than 10 h. It was concluded that the microsensor has high sensitivity and selectivity to dopamine and can be used to dynamically monitor the change of dopamine in vivo.
Biosensing Techniques/*instrumentation ; Biosensing Techniques/methods ; Brain Chemistry ; Corpus Striatum/*metabolism ; Dopamine/*analysis ; Microelectrodes ; Monitoring, Physiologic

We present a 33-year-old male patient with cerebellar ataxia. He was first considered to have a psychiatric conversion disorder but finally found to have chromosomal deletion in 7q31.2-31.32 involving Ca2⁺-dependent activator protein for secretion (CADPS) gene. When a targeted gene sequencing using next-generation sequencing panel and chromosomal microarray analysis were performed, an 8.6 Mb deletion within chromosome 7q31.2-31.32 was discovered. Deletion of CADPS gene in the 7q31.2-31.32 was suggested as the causative factor of cerebellar ataxia. Functional levels evaluated by Berg balance scale and modified Barthel index were improved via comprehensive rehabilitation including balance training and a dopamine agonist medication. To the best of our knowledge, this is the first report of chromosomal deletion in 7q31.2-31.32 including CADPS gene detected in patients with cerebellar ataxia.
Adult ; Cerebellar Ataxia ; Chromosome Disorders ; Conversion Disorder ; Dopamine Agonists ; Humans ; Male ; Microarray Analysis ; Rehabilitation

OBJECTIVE: The definite causes of obsessive-compulsive disorder (OCD) are still unknown. Evidences from familial, twin and segregation studies support the role of a genetic component in the etiology of OCD. There are growing evidences that OCD has specific neurochemical and neuroanatomical basis. It has been shown that serotonergic neurons play the predominant pathophysiological role in OCD. Recently, it has also been proposed that neurotransmitters other than serotonin play a role in the pathophysiology of OCD, and a series of studies have provided evidence that dopamine is involved in some OCD patients. Therefore, the aims of this study were to investigate the association between dopamine receptor D4 (DRD4) and OCD. METHODS: One hundred and fifteen OCD patients and 160 normal controls participated in this study. Genomic DNA was extracted from their blood. The genotypes and allele frequencies of the DRD4 polymorphism between OCD group and control group were compared. OCD patients were classified into early onset group (age of onset <17) and late onset group (age of onset > or =17) according to their onset age and the genotype and allele frequency were compared between two groups. Using principal component analysis, we had already derived 4 factors from 13 main contents of YBOCS checklist in the previous study and in this study, we investigated the association between these three factors and DRD4 genotypes. RESULTS: In this case-control study, we could find that the L-genotype frequencies of DRD4 were significantly higher in OCD than in normal control groups (chi2 test, p=0.04). There were no difference in genotype frequencies between early onset OCD group and late onset OCD group. In OCD group, patients with L-genotype had higher scores for the religious/somatic factor than the other groups (t test, p=0.009). CONCLUSIONS: The L-genotype of DRD4 may have negative effects on the development of OCD and religious/somatic factor of the obsessive-compulsive symptoms.
Age of Onset ; Case-Control Studies ; Checklist ; DNA ; Dopamine Plasma Membrane Transport Proteins ; Dopamine* ; Gene Frequency ; Genotype ; Humans ; Neurotransmitter Agents ; Obsessive-Compulsive Disorder* ; Principal Component Analysis ; Receptors, Dopamine* ; Serotonergic Neurons ; Serotonin

OBJECTIVETo compare therapeutic effects of acupuncture and embedding thread on depression and to probe the mechanism.

METHODSThirty-two adult SD rats, 16 females and 16 males, were randomly divided into a normal group, a model group, an acupuncture group and an embedding thread group, 8 rats in each group. Separated feeding, long-term unpredictable and middle stimulation stress were used for development of depression rat model. At the same time, the treatment groups were treated for 21 days. The changes of norepinephrine (NE), 5-hydoxytryptamine (5-HT) and dopamine (DA) contents in the brain were detected by high performance liquid chromatography-electrochemical detector.

RESULTSCompared with the normal group, 5-HT, NE and DA contents in the hypothalamus and hippocampus decreased significantly in the model group (P < 0.05, P < 0.01); compared with the model group, the contents of the central monoamine neurotransmitters increased in both the acupuncture group and the embedding thread group, but the embedding thread group had more obvious action in improvement of 5-HT and DA levels in the hypothalamus and DA level in the hippocampus than the acupuncture group with no significant difference between the two groups.

CONCLUSIONBoth acupuncture and embedding thread therapy are effective for the depression model rat. They play the therapeutic role through regulating central monoamine neurotransmitters.

Acupuncture Therapy ; methods ; Animals ; Biogenic Monoamines ; analysis ; Depression ; metabolism ; therapy ; Dopamine ; analysis ; Female ; Hippocampus ; chemistry ; Hypothalamus ; chemistry ; Male ; Norepinephrine ; analysis ; Rats ; Rats, Sprague-Dawley ; Serotonin ; analysis

OBJECTIVE: The objective of this study was to describe and characterize the clinical course of treatment for invasive prolactinoma patients using bromocriptine. METHODS: The study group included 23 patients who were treated with bromocriptine for their invasive prolactinomas. Clinical histories, serum prolactin level and pituitary hormone assessments, tumor diameter and signal intensity on sella magnetic resonance imaging (MRI), visual field exams and the dosage of medications were reviewed for each patient. RESULTS: During 30 months (median, range 6-99) of follow-up period, 19 patients treated with bromocriptine alone achieved biochemical remission. Four patients changed the medication to cabergoline due to the adverse effects or observed resistance of bromocriptine treatment. All of five patients who had visual symptoms improved after the course of medication. Four surgically treated patients were not able to discontinue medication because they could not maintain biochemical remission state without medication. Multivariate analysis showed that decreased enhancement on the initial followed MRI after medication and longer follow-up periods were associated with higher radiologic response. CONCLUSION: We reassure that the dopamine agonist is safe and effective for the treatment of invasive pituitary adenomas. Meanwhile, surgery has a limited role on biochemical remission. Decreased enhancement on the initial follow-up MRI after medication may reflect the treatment response. Further study is required to validate the role of MRI or other factors on the actual prognosis.
Bromocriptine* ; Dopamine Agonists ; Follow-Up Studies ; Humans ; Magnetic Resonance Imaging ; Multivariate Analysis ; Pituitary Neoplasms ; Prognosis ; Prolactin ; Prolactinoma* ; Visual Field Tests

Neural stem cells (NSCs) are multipotent and widely used in many research fields such as transplantation. Hypoxia not only improves the proliferation of various stem cells in vitro but also plays an important role in the differentiation of stem cells. The aim of the present study was to investigate the effect of hypoxia on the differentiation of NSCs. NSCs were isolated from the midbrain of embryonic Wistar rats (E13.5d), and cultured in serum-free DMEM/F12 medium (containing 20 ng/mL EGF, 20 ng/mL bFGF, 1% N2 and B27). The neurospheres were passaged every 3-5 d, and the third generation of NSCs was used for the following experiments. NSCs were induced under normoxia (20% O2) and hypoxia (3% O2), respectively, for 3 d, and then differentiated under normoxia for 5-7 d (DMEM/F12 medium containing 1% FBS, N2 and B27). Immunohistochemistry of nestin, NeuN and TH was used for NSC identification and differentiation assay. The number of TH-positive cells was evaluated by flow cytometry. Dopamine (DA) content in the supernatant of culture medium was detected by HPLC. The results showed that NSCs could self-renew and were all nestin-positive. NSCs under hypoxic condition differentiated more neurons than those under normoxic condition. The percentage of TH-positive cells differentiated from NSCs under normoxia and hypoxia was (10.25+/-1.03) % and (19.88+/-1.44) %, respectively. In addition, DA content in the supernatant of culture medium in hypoxia group increased significantly, about twice of that in normoxia group (P<0.05, n=8). The results demonstrate that hypoxia (3% O2) promotes the differentiation of NSCs into neurons, especially dopaminergic neurons. It is suggested that hypoxia may be a potential clinical tool to treat Parkinson's disease.
Animals ; Cell Differentiation ; Cell Hypoxia ; Cells, Cultured ; Dopamine ; analysis ; Female ; Neurons ; chemistry ; cytology ; Rats ; Rats, Wistar ; Stem Cells ; cytology ; Tyrosine 3-Monooxygenase ; analysis