Effects of Somatic, Depression Symptoms, and Sedentary Time on Sleep Quality in Middle-Aged Women with Risk Factors for Cardiovascular Disease.

Cardiovascular disease (CVD) is the second leading cause of death among Korean women, and its incidence is dramatically elevated in middle-aged women. This study aimed to identify the predictors of sleep quality, a CVD risk factor, in middle-aged women with CVD risk factors to provide foundational data for developing intervention strategies for the prevention of CVD. The subjects, 203 middle-aged women (40-65 years old) with one or more CVD risk factors were selected through convenience sampling and included in this descriptive correlational study. The effects of somatic symptoms, depression symptoms, and sedentary time on sleep quality were examined. CVD-related characteristics were analyzed using descriptive statistics, whereas the mean values of the independent variables were analyzed using t-tests and analysis of variance. Predictors of sleep quality were analyzed using multiple regression analysis. The results showed that sleep quality increased with decreasing somatic symptoms (ß = -0.36, p < 0.001), depression symptom score (ß = -0.17, p = 0.023), and daily sedentary time (ß = -0.13, p = 0.041), and the regression model was significant (F = 19.80, p < 0.001). Somatic symptoms are the most potent predictors of sleep quality in middle-aged women. Thus, intervention strategies that improve somatic symptoms are crucial for the enhancement of sleep quality, which deteriorates with advancing age.

Ameliorating effects of gypenosides on chronic stress-induced anxiety disorders in mice.

BACKGROUND: Ethanol extract from Gynostemma pentaphyllum (GP) shows anti-stress and anxiolytic functions in mice, and also protects dopamine neurons in 6-hydroxydopamine-lesioned rat model of Parkinson's disease. In addition, gypenosides (the gypenoside-enriched components of GP, GPS) have a protective effect on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced mouse model of Parkinson's disease. In this study, the ameliorating effects of GPS on chronic stress-induced anxiety disorders in mice were investigated. METHODS: Mice were orally treated with GPS (100 and 200 mg/kg) once a day for 10 days, followed by exposure to electric footshock (EF) stress (0.6 mA, 1 s every 5 s, 3 min). After the final administration of either GPS, water extract of GP (GP-WX) or ethanol extract of GP (GP-EX, positive control), the behavioral tests such as elevated plus-maze, marble burying and locomotor activity tests, and the biochemical parameters including dopamine, serotonin and corticosterone levels, and c-Fos expression were examined. RESULTS: Treatment with GPS (100 and 200 mg/kg) increased the number of open arm entries and the time spent on open arms in elevated plus-maze which were reduced by chronic EF stress. GPS (100 and 200 mg/kg) reduced the number of marbles buried which increased by chronic EF stress. In these states, the brain levels of dopamine and serotonin decreased by chronic EF stress and they were recovered by GPS. The serum levels of corticosterone increased by chronic EF stress were also reduced by GPS (100 and 200 mg/kg). Finally, chronic EF stress-induced c-Fos expression was markedly reduced by GPS (100 and 200 mg/kg) in the brain. GPS (100 and 200 mg/kg) also showed an equivalent efficacy on anxiolytic functions, as compared with GP-EX (50 mg/kg). However, GP-WX (50 mg/kg) showed a less effect on anxiety disorders than GP-EX (50 mg/kg) and GPS (100 and 200 mg/kg). CONCLUSION: These results suggest that GPS (100 and 200 mg/kg) has anxiolytic effects on chronic EF stress-induced anxiety disorders by modulating dopamine and serotonin neuronal activities, c-Fos expression and corticosterone levels. GPS may serve as a phytonutrient in chronic stress-induced anxiety disorders.

Effects of (-)-sesamin on 6-hydroxydopamine-induced neurotoxicity in PC12 cells and dopaminergic neuronal cells of Parkinson's disease rat models.

The present study investigated the effects of (-)-sesamin on 6-hydroxydopamine (6-OHDA)-induced neurotoxicity using PC12 cells and dopaminergic neuronal cells of 6-OHDA-lesioned rat model of Parkinson's disease (PD). In PC12 cells, treatment with (-)-sesamin (25 µM) reduced 6-OHDA (100 µM)-induced cell death and induced transient extracellular signal-regulated kinase (ERK1/2) phosphorylation and Bad phosphorylation at Ser112 (BadSer112). In contrast, sustained ERK1/2 phosphorylation, p38 mitogen-activated protein kinase (p38MAPK) and c-Jun N-terminal kinase (JNK1/2) phosphorylation, and cleaved-caspase-3 activity, all of which were induced by 6-OHDA (100 µM), were inhibited by treatment with (-)-sesamin (25 µM). Furthermore, co-treatment with (-)-sesamin (30 mg/kg, p.o.) once a day for 28 days significantly increased the number of tyrosine hydroxylase-immunopositive neuronal cells and the levels of dopamine, norepinephrine, 3,4-dihydroxyphenylacetic acid, and homovanillic acid in the substantia nigra-striatum of 6-OHDA-lesioned rat model of PD with or without L-DOPA treatment. These results suggest that (-)-sesamin protects 6-OHDA-induced cytotoxicity via the activation of transient ERK1/2-BadSer112 system and the inhibition of sustained ERK-p38MAPK-JNK1/2-caspase-3 system in PC12 cells. (-)-Sesamin also shows protective effects on long-term L-DOPA therapy in dopaminergic neuronal cells of PD rat models. (-)-Sesamin may serve as adjuvant therapeutics in PD.

Inexplicable Abdominal Pain due to Thoracic Spinal Cord Tumor.

Chronic, refractory abdominal pain without a metabolic or structural gastroenterological etiology can be challenging for diagnosis and management. Even though it is rare, it has been reported that such a recurrent abdominal pain associated with radicular pattern can be derived from structural neurologic lesion like spinal cord tumor. We experienced an unusual case of chronic recurrent abdominal pain that lasted for two years without definite neurologic deficits in a patient, who has been harboring thoracic spinal cord tumor. During an extensive gastroenterological workup for the abdominal pain, the spinal cord tumor had been found and was resected through surgery. Since then, the inexplicable pain sustained over a long period of time eventually resolved. This case highlights the importance of taking into consideration the possibility of spinal cord tumor in differential diagnosis when a patient complains of chronic and recurrent abdominal pain without other medical abnormalities.

Effects of gypenosides on anxiety disorders in MPTP-lesioned mouse model of Parkinson's disease.

Ethanol extract (GP-EX) of Gynostemma pentaphyllum (GP) ameliorates chronic stress-induced anxiety in mice. The present study investigated the effects of gypenoside-enriched components (GPS), GP-EX and water extract of GP (GP-WX) on MPTP lesion-induced affective disorders in C57BL/6 mice. GPS (50mg/kg) and GP-EX (50mg/kg) for 21 day-treatment period improved the symptom of anxiety disorders in the MPTP-lesioned mouse model of PD with or without L-DOPA treatment, which was examined by the elevated plus-maze and marble burying tests. In these states, treatments with GPS (50mg/kg) and GP-EX (50mg/kg) significantly increased the brain levels of dopamine and serotonin in the MPTP-lesioned mouse model of PD with or without l-DOPA treatment. In addition, treatments with GPS (50mg/kg) and GP-EX (50mg/kg) showed protective effects on dopaminergic neurons in MPTP-lesioned mouse model of PD with or without L-DOPA treatment. In contrast, GPS (30 mg/kg) and GP-WX (50mg/kg) showed anxiolytic effects in the same animal models, but it was not significant. These results suggest that GPS (50mg/kg) and GP-EX (50mg/kg) showed anxiolytic effects on affective disorders and protective effects on dopaminergic neurons by modulating the brain levels of dopamine and serotonin in the MPTP-lesioned mouse model of PD with or without l-DOPA treatment. Clinical trials of GPS and GP-EX need to be conducted further so as to develop adjuvant therapeutic agents for PD patients.

Compressive neuropathy of the posterior tibial nerve at the lower calf caused by a ruptured intramuscular baker cyst.

Baker cyst is an enlargement of the gastrocnemius-semimembranosus bursa. Neuropathy can occur due to either direct compression from the cyst itself or indirectly after cyst rupture. We report a unique case of a 49-year-old man with left sole pain and paresthesia who was diagnosed with posterior tibial neuropathy at the lower calf area, which was found to be caused by a ruptured Baker cyst. The patient's symptoms resembled those of lumbosacral radiculopathy and tarsal tunnel syndrome. Posterior tibial neuropathy from direct pressure of ruptured Baker cyst at the calf level has not been previously reported. Ruptured Baker cyst with resultant compression of the posterior tibial nerve at the lower leg should be included in the differential diagnosis of patients who complain of calf and sole pain. Electrodiagnostic examination and imaging studies such as ultrasonography or magnetic resonance imaging should be considered in the differential diagnosis of isolated paresthesia of the lower leg.

Association between radiculopathy and lumbar multifidus atrophy in magnetic resonance imaging.

BACKGROUND AND OBJECTIVES: Many studies have evaluated factors related to lumbar multifidus (MF) muscle atrophy. However, few studies have investigated radiculopathy and the MF muscle. In this study, the association between radiculopathy and lumbar MF muscle atrophy in magnetic resonance imaging (MRI) was evaluated. MATERIALS AND METHODS: In total, 100 patients with low back pain or radiating leg pain were examined. Their lumbar MRIs were visually analyzed semi-quantitatively for signs of lumbar MF muscle atrophy. The severity and extent of MF atrophy were compared between non-radiculopathy (Non-rad) and radiculopathy (Rad) groups. Asymmetry of MF atrophy was also compared between unilateral radiculopathy (UniR) and bilateral radiculopathy (BiR) groups. RESULTS: Significantly more severe and extensive MF atrophy was observed in the Rad group than in the Non-rad group (p< 0.01). However, no difference in the asymmetry of MF atrophy was found between the UniR and BiR groups (p> 0.05). CONCLUSION: More severe and extensive atrophy in the lumbar MF muscle was associated with radiculopathy. Thus, we might consider the presence of radiculopathy when severe and extensive multi-level involvement of MF atrophy is seen in MRI.

Anxiolytic effects of herbal ethanol extract from Gynostemma pentaphyllum in mice after exposure to chronic stress.

In this study, the effects of herbal ethanol extracts of Gynostemma pentaphyllum (GP-EX), on chronic electric footshock (EF) stress-induced anxiety disorders were investigated in mice, which were orally treated with GP-EX (30 mg/kg and 50 mg/kg) once a day for 14 days, followed by exposure to EF stress (2 mA, with an interval and duration of 10 s for 3 min). After the final exposure to EF stress, the elevated plus-maze and marble burying tests were performed, and the levels of dopamine and serotonin in the brain, the serum levels of corticosterone, and the expression of c-Fos in the paraventricular nuclei (PVN) were determined. Treatment with GP-EX (30 mg/kg and 50 mg/kg) significantly recovered the number of entries into open arms and time spent on open arms, which was reduced by chronic EF stress. GP-EX (30 mg/kg and 50 mg/kg) also reduced the number of marbles buried, which was increased by chronic EF stress. In addition, electric EF stress significantly decreased the levels of dopamine and serotonin in the brain, which was recovered by treatment with GP-EX (30 mg/kg and 50 mg/kg). The serum levels of corticosterone, which were markedly increased by chronic EF stress, were reduced by treatment with GP-EX (30 mg/kg and 50 mg/kg). Chronic EF stress-induced increases in c-Fos expression were also markedly reduced by GP-EX (30 mg/kg and 50 mg/kg) in the PVN. These results suggest that GP-EX shows anxiolytic functions, determined by the elevated plus-maze and marble burying tests, which are mediated by modulating the activity of dopamine and serotonin neurons as well as the expression of c-Fos in the brain, and the serum levels of corticosterone. Clinical trials of herbal GP-EX and its bioactive components need further investigation.

Neurotoxic effects of berberine on long-term L-DOPA administration in 6-hydroxydopamine-lesioned rat model of Parkinson's disease.

The effects of berberine on long-term administration of L-DOPA in 6-hydroxydopamine (6-OHDA)-lesioned rat model of Parkinson's disease (PD) were investigated. Rat models of PD were prepared by 6-OHDA lesions in the ipsilateral sides, and then were treated with berberine (5 and 15 mg/kg) and/or L-DOPA (10 mg/kg) once daily for 21 days. Treatments with either concentration of berberine (5 and 15 mg/kg) in 6-OHDA-lesioned groups decreased the numbers of tyrosine hydroxylase (TH)-immunopositive neurons in the substantia nigra and the levels of dopamine, norepinephrine, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in the striatum as compared to 6-OHDA-lesioned groups. In addition, dopaminergic neuronal cell death of the ipsilateral sides in 6-OHDA-lesioned groups was attenuated by L-DOPA administration. However, both concentrations of berberine in 6-OHDA-lesioned groups treated with L-DOPA aggravated the numbers of TH-immunopositive neurons in the substantia nigra and the levels of dopamine, norepinephrine, DOPAC and HVA in the striatum as compared to rats not treated with berberine. These results suggest that berberine leads to the degeneration of dopaminergic neuronal cells in the substantia nigra in the rat model of PD with chronic L-DOPA administration. Long-term L-DOPA therapy that may involve possibly neurotoxic isoquinoline agents including berberine should involve monitoring for adverse symptoms.

Restoration of electric footshock-induced immunosuppression in mice by Gynostemma pentaphyllum components.

The immunomodulatory effects of the ethanol extract of Gynostemma pentaphyllum (GP-EX) were examined in electric footshock (EFS)-stressed mice. The mice were orally administered various doses of GP-EX for 7 days before exposure to EFS (duration: 3 min, interval: 10 s, intensity: 2 mA) once a day from day 8 for 14 days with continuous daily feeding of GP-EX. Oral administration of GP-EX to mice prevented EFS stress-induced immunosuppression as determined by the lymphoid organ (thymus and spleen) weight and cellularity. In addition, oral administration of GP-EX restored EFS-suppressed functional properties of mature lymphocytes in terms of concanavalin A-induced proliferation of splenocytes and lipopolysaccharide-induced cytokine production (TNF-α, IL-1ß). Furthermore, we found that mice that were orally administered with GP-EX generated much more potent ovalbumin-specific cytotoxic T lymphocyte responses upon intravenous ovalbumin injection compared to the untreated controls. These results demonstrate that oral administration of the ethanol extract of Gynostemma pentaphyllum could increase host defense in immunocompromised situations such as stress-induced immunosuppression.

Modulation of PC12 cell viability by forskolin-induced cyclic AMP levels through ERK and JNK pathways: an implication for L-DOPA-induced cytotoxicity in nigrostriatal dopamine neurons.

The intracellular levels of cyclic AMP (cAMP) increase in response to cytotoxic concentrations of L-DOPA in PC12 cells, and forskolin that induces intracellular cAMP levels either protects PC12 cells from L-DOPA-induced cytotoxicity or enhances cytotoxicity in a concentration-dependent manner. This study investigated the effects of cAMP induced by forskolin on cell viability of PC12 cells, relevant to L-DOPA-induced cytotoxicity in Parkinson's disease therapy. The low levels of forskolin (0.01 and 0.1 µM)-induced cAMP increased dopamine biosynthesis and tyrosine hydroxylase (TH) phosphorylation, and induced transient phosphorylation of ERK1/2 within 1 h. However, at the high levels of forskolin (1.0 and 10 µM)-induced cAMP, dopamine biosynthesis and TH phosphorylation did not increase, but rapid differentiation in neurite-like formation was observed with a steady state. The high levels of forskolin-induced cAMP also induced sustained increase in ERK1/2 phosphorylation within 0.25-6 h and then led to apoptosis, which was apparently mediated by JNK1/2 and caspase-3 activation. Multiple treatment of PC12 cells with nontoxic L-DOPA (20 µM) for 4-6 days induced neurite-like formation and decreased intracellular dopamine levels by reducing TH phosphorylation. These results suggest that the low levels of forskolin-induced cAMP increased dopamine biosynthesis in cell survival via transient ERK1/2 phosphorylation. In contrast, the high levels of forskolin-induced cAMP induced differentiation via sustained ERK1/2 phosphorylation and then led to apoptosis. Taken together, the intracellular levels of cAMP play a dual role in cell survival and death through the ERK1/2 and JNK1/2 pathways in PC12 cells.

Modulatory effects of sesamin on dopamine biosynthesis and L-DOPA-induced cytotoxicity in PC12 cells.

The effects of sesamin on dopamine biosynthesis and L-DOPA-induced cytotoxicity in PC12 cells were investigated. Sesamin at concentration ranges of 20-75 µM exhibited a significant increase in intracellular dopamine levels at 24 h: 50 µM sesamin increased dopamine levels to 133% and tyrosine hydroxylase (TH) activity to 128.2% of control levels. Sesamin at 20-100 µM rapidly increased the intracellular levels of cyclic AMP (cAMP) to 158.3%-270.3% of control levels at 30 min. At 50 µM, sesamin combined with L-DOPA (50, 100 and 200 µM) further increased the intracellular dopamine levels for 24 h compared to L-DOPA alone. In the absence or presence of L-DOPA (100 and 200 µM), sesamin (50 µM) increased the phosphorylation of TH, cAMP-dependent protein kinase (PKA), and cAMP-response element-binding protein (CREB), as well as the mRNA levels of TH and CREB for 24 h, an effect which was reduced by L-DOPA (100 and 200 µM). In addition, 50 µM sesamin exhibited a protective effect against L-DOPA (100 and 200 µM)-induced cytotoxicity via the inhibition of reactive oxygen species (ROS) production and superoxide dismutase reduction, induction of extracellular signal-regulated kinase (ERK)1/2 and BadSer112 phosphorylation and Bcl-2 expression, and inhibition of cleaved-caspase-3 formation. These results suggested that sesamin enhanced dopamine biosynthesis and L-DOPA-induced increase in dopamine levels by inducing TH activity and TH gene expression, which was mediated by cAMP-PKA-CREB systems. Sesamin also protected against L-DOPA (100-200 µM)-induced cytotoxicity through the suppression of ROS activity via the modulation of ERK1/2, BadSer112, Bcl-2, and caspase-3 pathways in PC12 cells. Therefore, sesamin might serve as an adjuvant phytonutrient for neurodegenerative diseases.

[An experience of cyberknife treatment in patients with advanced pancreaticobilliary malignancy].

BACKGROUND/AIMS: CyberKnifeTM stereotactic body radiotherapy (SBRT) has been thought as a promising treatment modality for inoperable or recurred pancreaticobiliary malignancies. But, clinical course of CyberKnifeTM treatment have not been established yet, so we report the experience of CyberKnifeTM treatment in 19 patients with recurred or advanced pancreaticobilliary malignancies. METHODS: Between July 2008 and May 2009, 19 patients (gallbladder cancer 4, common bile duct cancer 5, and pancreatic cancer 10) with recurred (12) and advanced pancreaticobiliary cancer (7) underwent CyberKnifeTM treatment in Soonchunhyang University Hospital. Tumor size was evaluated at 1, 3, 6, 8 and every 3 months after SBRT. RESULTS: The mean age was 60.2 years, and the mean size of target lesions was 28.1±1.30 mm. After CyberKnifeTM treatment, the average size of target lesions was decreased; 2.53±4.18 mm from months 0-1 in 19 patients, 2.47±4.7 mm from months 1-3 in 15 patients, 0.08±5.11 mm from months 3-6 in 12 patients. However, the average size of target lesions was increased 3.67±8.98 mm from months 6-8 in 6 patients. There were 2 cases of massive duodenal ulcer bleeding after CyberKnifeTM treatment, one of them expired due to ulcer bleeding. Also, other minor complications appeared such as 1 case of abdominal pain and 1 case of diarrhea. CONCLUSIONS: CyberKnifeTM treatment seems to be effective in local control of pancreaticobiliary cancer, but we experienced serious complications. Further prospective studies will be needed for the proper evaluation of role of CyberknifeTM treatment in patients with advanced pancreaticobiliary malignancies.

Interstitial pneumonitis in a patient with chronic hepatitis C and chronic renal failure on interferon therapy.

After 4-months of alpha interferon (IFN-α), a 64-year old woman with chronic hepatitis C developed a cough and dyspnea and showed diffuse infiltrative opacities on her chest X-ray. Her symptoms persisted after stopping the IFN-α therapy. Pulmonary function testing revealed a reduced forced vital capacity. High-resolution computed tomography of the lung showed peripheral and peribronchovascular ground glass attenuation and consolidation associated with reticulation. Bronchoalveolar lavage was performed for further evaluation and showed a lymphocyte level of 8.2%, an uncommon finding in IFN-α-induced interstitial pneumonitis. We performed a lung biopsy to diagnose her disease and it suggested interstitial pneumonitis. This was considered to be due to the immunomodulatory effects of INF-α. Although rare, any sign of significant pulmonary involvement should be evaluated.

Effects of berberine on 6-hydroxydopamine-induced neurotoxicity in PC12 cells and a rat model of Parkinson's disease.

Protoberberine isoquinoline alkaloids including berberine inhibit dopamine biosynthesis and aggravate l-DOPA-induced cytotoxicity in PC12 cells. In this study, the effects of berberine on 6-hydroxydopamine (6-OHDA)-induced cytotoxicity in PC12 cells and on unilateral 6-OHDA-lesioned rats were investigated. In PC12 cells, berberine at 10 and 30µM associated with 6-OHDA (10, 20, and 50µM) enhanced cytotoxicity at 48h compared to 6-OHDA alone, indicated by an increase in apoptotic cell death. In addition, treatment with berberine (5 and 30mg/kg, i.p.) for 21 days in 6-OHDA-lesioned rats markedly depleted tyrosine hydroxylase-immunopositive cells in the substantia nigra as compared to berberine-untreated rats. Further, the levels of dopamine and norepinephrine were also significantly decreased by berberine administration (5 and 30mg/kg) in the striatal regions of 6-OHDA-lesioned rats. These results suggested that berberine aggravated 6-OHDA-induced cytotoxicity in PC12 cells, and led to the degeneration of dopaminergic neuronal cells in the substantia nigra of 6-OHDA-lesioned rats. It is, therefore, suggested that the use of long-term l-DOPA therapy with isoquinoline derivatives including berberine may need to be examined for the presence of adverse symptoms.

A case of asymptomatic aspiration of a capsule endoscope with a successful resolution.

Aspiration is a very rare complication of capsule endoscopy, but it is potentially life-threatening and should be considered an emergency requiring immediate intervention since it can evolve into major airway compromise and obstructive pneumonitis. We experienced a case of asymptomatic aspiration of a capsule in a 75-year-old man. The aspirated capsule was diagnosed on routine chest and abdomen X-rays to confirm its position after ingestion. The capsule was removed via bronchoscopy using a net, without sequelae, after inducing the patient to cough. To prevent this complication, a thorough history of swallowing disorders is needed before capsule ingestion, and patients with swallowing difficulties should have the capsule placed in the duodenum endoscopically. Moreover, on capsule aspiration, cough induction is the most effective method of capsule removal.

Neuroprotective effects of herbal ethanol extracts from Gynostemma pentaphyllum in the 6-hydroxydopamine-lesioned rat model of Parkinson's disease.

6-Hydroxydopamine administration for 28 days (8 microg/2 microL) reduced the number of tyrosine hydroxylase (TH)-immunopositive neurons to 40.2% in the substantia nigra compared to the intact contralateral side. Dopamine, 3,4-dihydroxyphenylacetic acid, homovanillic acid and norepinephrine levels were reduced to 19.1%, 52.3%, 47.1% and 67.4% in the striatum of 6-hydroxydopamine-lesioned rats compared to the control group, respectively. However, an oral administration of herbal ethanol extracts from Gynostemma pentaphyllum (GP-EX) (10 mg/kg and 30 mg/kg) starting on day 3 post-lesion for 28 days markedly ameliorated the reduction of TH-immunopositive neurons induced by 6-hydroxydopamine-lesioned rat brain from 40.2% to 67.4% and 75.8% in the substantia nigra. GP-EX administration (10 and 30 mg/kg) also recovered the levels of dopamine, 3,4-dihydroxyphenylacetic acid, homovanillic acid and norepinephrine in post-lesion striatum to 64.1% and 65.0%, 77.9% and 89.7%, 82.6% and 90.2%, and 88.1% and 89.2% of the control group. GP-EX at the given doses did not produce any sign of toxicity such as weight loss, diarrhea and vomiting in rats during the 28 day treatment period and four gypenoside derivatives, gynosaponin TN-1, gynosaponin TN-2, gypenoside XLV and gypenoside LXXIV were identified from GP-EX. These results suggest that GP-EX might be helpful in the prevention of Parkinson's disease.

Effects of scoparone on dopamine biosynthesis and L-DOPA-induced cytotoxicity in PC12 cells.

The effects of scoparone on dopamine biosynthesis and L-DOPA-induced cytotoxicity in PC12 cells were investigated. PC12 cells treated with scoparone at concentrations of 100-200 microM showed a 128-136% increase in dopamine levels over the course of 24 hr. Scoparone significantly increased the secretion of dopamine into the culture medium. Under the same conditions, the activities of tyrosine hydroxylase (TH) and aromatic L-amino acid decarboxylase (AADC) were enhanced by treatment with 200 microM scoparone for 6-48 hr, but the activity of TH was regulated for a longer period than that of AADC. The intracellular levels of cyclic AMP and Ca(2+) were increased by treatment with 200 microM scoparone. The levels of TH mRNA and the phosphorylation of cyclic AMP-response element-binding protein (CREB) were also significantly increased by treatment with 200 microM scoparone. In addition, scoparone at a concentration of 200 microM stimulated the activities of cyclic AMP-dependent protein kinase (PKA), protein kinase C (PKC), and Ca(2+)/calmodulin kinase II (CaMK II). Finally, pretreatment with 200 microM scoparone reduced the cytotoxicity induced by L-DOPA (20-100 microM) at 24 hr. These results suggest that scoparone enhances dopamine biosynthesis by regulating TH activity and TH gene expression, which is mediated by the PKA, CREB, PKC, and CaMK II pathways, and protects cells from L-DOPA-induced cytotoxicity by inducing cyclic AMP-PKA systems in PC12 cells.

Catalponol enhances dopamine biosynthesis and protects against L-DOPA-induced cytotoxicity in PC12 cells.

The effects of catalponol (1) on dopamine biosynthesis and L-DOPA-induced cytotoxicity in PC12 cells were investigated. Catalponol at concentration ranges of 1-5 microM increased the intracellular levels of dopamine at 12-48 h. Catalponol at concentrations of up to 10 microM did not alter cell viability. Tyrosine hydroxylase (TH) activity was enhanced by 1 at 3 microM in a time-dependent manner, but aromatic L-amino acid decarboxylase activity was not. Catalponol also increased the intracellular levels of cyclic AMP and TH phosphorylation. In addition, catalponol at 3 microM associated with L-DOPA (20-50 microM) further enhanced the increases in dopamine levels induced by L-DOPA (50-100 microM) at 24 h. Catalponol at 2-5 microM inhibited L-DOPA (100-200 microM)-induced cytotoxicity at 48 h. These results suggest that 1 enhanced dopamine biosynthesis by inducing TH activity and protected against L-DOPA-induced cytotoxicity in PC12 cells, which was mediated by the increased levels of cyclic AMP.

Effects of base changes at the transcription start site on stringent control of rnpB in Escherichia coli.

The GC-rich discriminator sequence between the -10 region and the transcription start site of the rnpB promoter is responsible for stringent control of M1 RNA synthesis. The rnpB promoter also contains a G nucleotide at the previously identified transcription start site. In this study, we examined by mutagenesis of G to A whether this +1G nucleotide is involved in the stringent response. We found that the change did not alter the stringent response. Since the +1 mutation might alter transcription initiation, we compared the transcription start sites of the wt and mutant promoters by primer extension analysis. Surprisingly, we found that wild type rnpB transcription starts at both the +1G position (70%) and the -1C position (30%), and that the +1A mutation led to transcription initiation exclusively at the -1C position. We also generated two transversion mutations at the -1 position, both of which led to transcription starting exclusively at that position. The -1G mutant promoter gave a stringent signal similar to the wild-type, whereas the -1A mutant generated a significantly less stringent signal. Base on these results, we propose that a short sequence, up to 7 bp downstream of the -10 region, is involved in the stringent response of the rnpB promoter.