Publications by authors named "Ho-Joo Lee"

Background: Treatment effectiveness holds considerable importance in the association between service quality and satisfaction in medical service studies. While complementary and alternative medicine (CAM) use grows more prominent, comprehensive evaluations of the quality of medical service at CAM-oriented hospitals are scarce. This study assesses the quality of medical services provided at a CAM-oriented hospital of Korean medicine using the service encounter system approach and analyzes the influence of treatment effectiveness on patient loyalty.

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Article Synopsis
  • Olanzapine (OLZ) is an atypical antipsychotic used to treat bipolar disorder, but its exact way of working isn't fully understood.
  • This study investigated whether chronic OLZ treatment could lower arachidonic acid (AA) turnover in rat brains, similar to other mood stabilizers like lithium and valproate.
  • Results showed that chronic OLZ decreased levels of unesterified AA and its turnover in brain cells, and reduced the activity of cyclooxygenase and levels of the proinflammatory compound prostaglandin E₂, potentially linking these effects to its effectiveness in managing bipolar disorder.
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Arachidonic acid (AA) signaling is upregulated in the caudate-putamen and frontal cortex of unilaterally 6-hydroxydopamine (6-OHDA) lesioned rats, a model for asymmetrical Parkinson disease. AA signaling can be coupled to D(2)-like receptor initiated AA hydrolysis from phospholipids by cytosolic phospholipase A(2) (cPLA(2)) and subsequent metabolism by cyclooxygenase (COX)-2. In unilaterally 6-OHDA- and sham-lesioned rats, we measured brain expression of cPLA(2), other PLA(2) enzymes, and COX-2.

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Chronic administration to rats of mood-stabilizers that are effective against mania in bipolar disorder, is reported to downregulate markers of the brain arachidonic acid cascade. We hypothesized that chronic administration of lamotrigine, which is used to treat depression and rapid cycling in bipolar disorder, might do so as well. Male CDF rats were administered a therapeutically relevant dose of lamotrigine (10 mg/kg) or vehicle intragastrically once daily for 42 days.

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Bipolar disorder is a major medical, social and economic burden worldwide. However, the biochemical basis of the disorder and the mechanisms of action of effective antibipolar disorder drugs remain elusive. In this paper, we review how combining a kinetic approach to studying the turnover of fatty acids within brain phospholipids of unanesthetized rats along with chronic administration of antimanic drugs (lithium, valproate and carbamazepine) at therapeutically relevant doses, shows that the brain arachidonic acid cascade is a common target of these drugs.

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Whereas antibipolar drug administration to rats reduces brain arachidonic acid turnover, excessive N-methyl-d-aspartate (NMDA) signaling is thought to contribute to bipolar disorder symptoms and may increase arachidonic acid turnover in rat brain phospholipids. To determine whether chronic NMDA would increase brain arachidonic acid turnover, rats were daily administered NMDA (25 mg/kg, ip) or vehicle for 21 days. In unanesthetized rats, on day 21, [1-(14)C]arachidonic acid was infused intravenously and arterial blood plasma was sampled until the animal was euthanized at 5 min and its microwaved brain was subjected to chemical and radiotracer analysis.

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Objectives: Valproic acid (VPA) is used to treat bipolar disorder, but its mechanism of action is not clear. VPA shares many cellular and molecular targets with lithium, including reducing arachidonic acid turnover in rat brain phospholipids and cyclooxygenase-2 (COX-2) protein level and activity in rat brain.

Methods: We examined the effect of chronic VPA administration (200 mg/kg body weight for 30 days) to produce therapeutically relevant plasma concentrations, on transcription factors (NF-kappaB, AP-1, AP-2, C/EBP, CREB, and ETS) that are known to regulate the COX-2 gene.

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Cholinergic muscarinic receptors, when stimulated by arecoline, can activate cytosolic phospholipase A(2) (cPLA(2)) to release arachidonic acid (AA) from membrane phospholipid. This signal can be imaged in the brain in vivo using quantitative autoradiography following the intravenous injection of radiolabeled AA, as an increment in a regional brain AA incorporation coefficient k*. Arecoline increases k* significantly in brain regions having muscarinic M(1,3,5) receptors in wild-type but not in cyclooxygenase (COX)-2 knockout mice.

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Excessive N-methyl-D-aspartate (NMDA) signaling is thought to contribute to bipolar disorder symptoms. Lithium and carbamazepine, effective against bipolar mania, are reported in rats to reduce brain transcription of an arachidonic acid selective calcium-dependent cytosolic phospholipase A(2) (cPLA(2)), as well as expression of one of its transcription factors, activator protein (AP)-2. In this study, we determined if chronic administration of NMDA (25 mg/kg i.

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Neuroinflammation, caused by a 6-day intracerebroventricular infusion of lipopolysaccharide (LPS) in rats, is associated with the up-regulation of brain arachidonic acid (AA) metabolism markers. Because chronic LiCl down-regulates markers of brain AA metabolism, we hypothesized that it would attenuate increments of these markers in LPS-infused rats. Incorporation coefficients k* of AA from plasma into brain, and other brain AA metabolic markers, were measured in rats that had been fed a LiCl or control diet for 6 weeks, and subjected in the last 6 days on the diet to intracerebroventricular infusion of artificial CSF or of LPS.

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Rationale: Drugs that are effective in treating the manic phase of bipolar disorder (lithium, carbamazepine, and valproate) upon chronic administration to rats decrease the turnover of arachidonic acid in their brain phospholipids. Lamotrigine may not be effective in the manic phase, but is effective in delaying the depressive phase and for treating rapid cycling bipolar disorder. Thus, lamotrigine provides a pharmacological tool to differentiate if downregulation of arachidonic acid turnover is specific to drugs effective in the manic phase of bipolar disorder.

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Rationale: Fluoxetine is used to treat unipolar depression and is thought to act by increasing the concentration of serotonin (5-HT) in the synaptic cleft, leading to increased serotonin signaling. The 5-HT(2A/2C) receptor subtypes are coupled to a phospholipase A(2) (PLA(2)). We hypothesized that chronic fluoxetine would increase the brain activity of PLA(2) and the turnover rate of arachidonic acid (AA) in phospholipids of the unanesthetized rat.

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The extent to which the adult brain can derive some of its arachidonic acid (AA) through internalized synthesis from linoleic acid (LA) is uncertain. Thus, we determined for plasma-derived LA in vivo rates for brain incorporation, beta-oxidation, and conversion to AA. Adult male unanesthetized rats, reared on a diet enriched in LA but low in AA, were infused intravenously for 5 min with [1-(14)C]LA.

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This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy).

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Background: G-protein receptor kinases (GRKs) are a family of serine/threonine kinases involved in the homologous desensitization of agonist activated G-protein coupled receptors (GPCRs). G-protein coupled receptor supersensitivity, possibly as a result of decreased GRK, has been suggested in affective disorders.

Methods: We used immunobloting to determine if chronic, therapeutically relevant doses of lithium (Li+), carbamazepine (CBZ), and valproate (VPA), would increase GRK2/3 protein levels in rat frontal cortex.

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Tissues changes in FA metabolism can occur quite rapidly in response to ischemia and may require immediate microwave fixation to determine basal concentrations. The present study aimed to quantify the effects of immediate no-flow ischemia on concentrations of individual nonesterified FA (NEFA) and acyl-CoA species in the rat heart. Male CDF 344 rats were anesthetized and decapitated either 5 min prior to being microwaved (5.

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Background: The heart is rich in cardiolipin, a phospholipid acylated in four sites, predominately with linoleic acid. Whether or not aging alters the composition of cardiolipin acyl chains is controversial. We therefore measured the fatty acid concentration of cardiolipin in hearts of 4, 12 and 24 month old rats that consumed one diet, adequate in fatty acids for the duration of their life.

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Background: The basis for carbamazepine's efficacy in treating bipolar disorder is not agreed on. One hypothesis is that, similar to lithium and valproate (antibipolar drugs), carbamazepine might selectively decrease the kinetics of arachidonic acid (AA) in brain phospholipids.

Methods: To assess whether it targets brain AA kinetics, we administered carbamazepine (25 mg/kg/day, IP) to rats for 30 days and then determined its effect compared with that of vehicle on incorporation and turnover rates of AA and docosahexaenoic acid (DHA) in brain phospholipids.

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Interest in the potential therapeutic utility of topiramate for treating bipolar disorder was stimulated by published reports of investigator-initiated open label clinical studies. Because chronic lithium, carbamazepine and valproate decrease the turnover of arachidonic acid (AA) but not docosahexaenoic acid (DHA) in brain phospholipids of the awake rat, we tested if topiramate would produce similar results. Rats received either topiramate (20 mg/kg twice per day) or vehicle for 14 days and then while unanesthetized were infused intravenously with either [1-(14)C] AA or [1-(14)C] DHA for 5 min while blood was collected from the femoral artery at fixed times.

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Anandamide (N-arachidonoylethanolamine, AEA) is the putative endogenous ligand for the CB1 receptor. Despite being regulated enzymatically, brain AEA concentrations are quite variable and have been reported to increase in response to ischemia and post-mortem delay. Because these observations are similar to the effects of decapitation on brain concentrations of unesterified arachidonic acid and several of its metabolites, we propose that brain AEA concentrations also increase with decapitation and that immediate head-focused microwave irradiation is necessary to quantify basal brain AEA levels correctly.

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Rationale And Objectives: Signal transduction involving the activation of phospholipase A2 (PLA2) to release arachidonic acid (AA) from membrane phospholipids, when coupled to dopamine D1- and D2-type receptors, can be imaged in rats having a chronic unilateral lesion of the substantia nigra. It is not known, however, if the signaling responses occur in the absence of a lesion. To determine this, we used our in vivo fatty acid method to measure signaling in response to D1 and D2 receptor agonists given acutely to unanesthetized rats.

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Rationale: It has been reported that each of three drugs effective in treating bipolar disorder (lithium, carbamazepine, and valproate) decreases the turnover of arachidonic acid (AA, 20:4n-6) in brain phospholipids of the awake rat. It is also known that lithium and carbamazepine do so without decreasing the turnover of docosahexaenoic acid (DHA, 22:6n-3).

Objective: The aim of this study was to see whether valproate also specifically targets the turnover of AA but not of DHA in brain phospholipids.

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The intracellular degradation of polyhydroxyalkanoic acid (PHA) in pseudomonads was investigated by first-order kinetics analysis using the initial rate method. One type of PHA was accumulated in five Pseudomonas spp., P.

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