Association of the choline acetyltransferase gene with responsiveness to acetylcholinesterase inhibitors in Alzheimer's disease.

INTRODUCTION: The response to acetylcholinesterase inhibitors (AChEIs) of Alzheimer's disease (AD) patients varies depending on the genetic characteristics of the patient. We have examined the association of response to AChEIs and genetic polymorphisms in AD patients. METHODS: 158 patients with AD underwent treatment with AChEIs, and the therapeutic effect was assessed with the Korean version of the Mini Mental State Examination (K-MMSE). The association of 25 SNPs located in 3 genes (CHAT, CHT and ACHE) with changes in the K-MMSE score was analyzed. RESULTS: The response to AChEIs in AD patients was significantly associated with 2 SNPs on the intronic region of CHAT rs2177370 (uncorrected P=0.0025, FDR controlled P=0.026) and rs3793790 (uncorrected P=0.0024, FDR controlled P=0.026). CONCLUSION: The results of our study confirmed again that genetic polymorphism of CHAT has an influence on drug response in AD.

Pathophysiology of hypercortisolism in depression: pituitary and adrenal responses to low glucocorticoid feedback.

OBJECTIVE: To test three theories of hypercortisolemia in depression-hypothalamic overdrive, impaired glucocorticoid feedback, or autonomous cortisol production. METHOD: We applied an overnight low-cortisol feedback strategy by administering metyrapone to hypercortisolemic depressed in-patients and control subjects. RESULTS: Under metyrapone, the increases of plasma adrenocorticotropic hormone (ACTH) concentrations and of basal and pulsatile ACTH secretion were not exaggerated in hypercortisolemic depressed patients compared with control subjects. ACTH approximate entropy (ApEn) did not differ at baseline or under metyrapone. Thus, neither hypothalamic overdrive nor irregular ACTH secretion was seen. We did not detect impaired cortisol feedback: the ACTH response was not reduced, and ApEn measures that are sensitive to feedback changes were comparable in both groups. Metyrapone disrupted cortisol secretory regularity in depressed and control subjects. On the baseline day, basal cortisol secretion was significantly increased and was highly irregular (high ApEn), and ACTH-cortisol cross-ApEn was markedly elevated in high-cortisol patients. CONCLUSION: Classical feed-forward overdrive and impaired feedback theories of hypercortisolemia in depression were not supported. Depressive hypercortisolemia may result from alternative pathophysiological mechanisms involving irregular basal hypersecretion of cortisol, associated with adrenal enlargement, possibly through splanchnic sympathetic activation of the adrenal cortex.

Rubidium and lithium: opposite effects on amine-mediated excitement.

In mice the activation caused by morphine was antagonized by previous treatment with lithium and was potentiated by previous treatment with rubidium. Other antimanic drugs antagonized the morphine activation as well. The effect of rubidium was similar to that of the antidepressant drugs imipramine and pargyline. Rubidium may merit clinical evaluation as an antidepressant agent in man.

META060 inhibits multiple kinases in the NF-kappaB pathway and suppresses LPS--mediated inflammation in vitro and ex vivo.

OBJECTIVE: We investigated whether a novel candidate META060 targeted the inflammatory signal transduction without affecting constitutive COX-2 enzymatic activity in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. We also investigated its bioavailability in humans and its anti-inflammatory effect ex vivo. METHODS: We measured prostaglandin E(2), nitric oxide, TNFalpha and IL-6 by ELISA, COX-2 protein by Western blot, NF-kappaB nuclear binding by electrophoretic mobility shift assays, and NF-kappaB activation by luciferase assay. Kinase inhibitions were measured by cell-free assays. Bioavailability was tested in 4 human subjects consuming 940 mg META060. LPS-activated TNFalpha and IL-6 were measured in peripheral blood mononuclear cells (PBMC) isolated from 1 subject up to 6 hours post administration. RESULTS: META060 dose-dependently inhibited prostaglandin E(2) and nitric oxide formation, COX-2 abundance, and NF-kappaB activation. In cell-free assays, META060 inhibited multiple kinases in the NF-kappaB signaling pathway, including BTK, PI3K, and GSK3. META060 was detected in the plasma of the subjects; isolated PBMC were resistant to LPS-stimulated TNFalpha and IL-6 production. CONCLUSION: Without inhibiting COX-2 enzyme, META060 reduces the inflammation by inhibiting multiple kinases involved in NF-kappaB pathway, and may have potential as a safe anti-inflammatory therapeutic.

Sulodexide in venous disease.

Sulodexide is a glycosaminoglycan extracted from porcine intestinal mucosa. The purpose of this review is to discuss sulodexide's complex pharmacological profile and its clinical applications for venous disease. Sulodexide has wide-ranging biological effects on the vascular system, including antithrombotic, profibrinolytic, anti-inflammatory, endothelial protective and vasoregulatory effects. Sulodexide has emerged as a potential therapeutic option for the management of chronic venous insufficiency, including venous ulceration, and the prevention of recurrent venous thromboembolism, with a low rate of major bleeding complications. Sulodexide's pleiotropic vascular effects may facilitate the management of common venous disorders.

Distribution of unlinked transpositions of a Ds element from a T-DNA locus on tomato chromosome 4.

In maize, receptor sites for unlinked transpositions of Activator (Ac) elements are not distributed randomly. To test whether the same is true in tomato, the receptor sites for a Dissociation (Ds) element derived from Ac, were mapped for 26 transpositions unlinked to a donor T-DNA locus on chromosome 4. Four independent transposed Dss mapped to sites on chromosome 4 genetically unlinked to the donor T-DNA, consistent with a preference for transposition to unlinked sites on the same chromosome as opposed to sites on other chromosomes. There was little preference among the nondonor chromosomes, except perhaps for chromosome 2, which carried seven transposed Dss, but these could not be proven to be independent. However, these data, when combined with those from other studies in tomato examining the distribution of transposed Acs or Dss among nondonor chromosomes, suggest there may be absolute preferences for transposition irrespective of the chromosomal location of the donor site. If true, transposition to nondonor chromosomes in tomato would differ from that in maize, where the preference seems to be determined by the spatial arrangement of chromosomes in the interphase nucleus. The tomato lines carrying Ds elements at known locations are available for targeted transposon tagging experiments.

Germinal transpositions of the maize element Dissociation from T-DNA loci in tomato.

We have analyzed the pattern of germinal transpositions of artificial Dissociation (Ds) transposons in tomato. T-DNA constructs carrying Ds were transformed into tomato, and the elements were trans-activated by crossing to lines transformed with a stabilized Activator (sAc) that expressed the transposase gene. The sAc T-DNA carried a GUS gene to monitor its segregation. The Ds elements were inserted in a marker gene so that excision from the T-DNA could be monitored. The Ds elements also carried a genetic marker that was intended to be used for reinsertion selection of the elements after excision. Unfortunately, this gene was irreversibly inactivated on crossing to sAc. Germinal excision frequencies of Ds averaged 15-40%, but there was large variation between and within plants. Southern hybridization analysis of stable transposed Ds elements indicated that although unique transpositions predominate, early transposition events can lead to large clonal sectors in the germline of developing plants and to sibling offspring carrying the same transposition event. Multiple germinal transpositions from three different loci were examined for uniqueness, and 15 different transpositions were identified from each of three T-DNA loci that carried a single independent Ds. These were mapped relative to the donor T-DNA loci, and for each locus 70-80% of the transposed elements were closely linked to the donor site.

Intramolecular proton transfer in the cyclization of geranylgeranyl diphosphate to the taxadiene precursor of taxol catalyzed by recombinant taxadiene synthase.

BACKGROUND: The committed step in the biosynthesis of the anticancer drug taxol in yew (Taxus) species is the cyclization of geranylgeranyl diphosphate to taxa-4(5),11(12)-diene. The enzyme taxadiene synthase catalyzes this complex olefin cation cyclization cascade involving the formation of three rings and three stereogenic centers. RESULTS: Recombinant taxadiene synthase was incubated with specifically deuterated substrates, and the mechanism of cyclization was probed using MS and NMR analyses of the products to define the crucial hydrogen migration and terminating deprotonation steps. The electrophilic cyclization involves the ionization of the diphosphate with closure of the A-ring, followed by a unique intramolecular transfer of the C11 proton to the re-face of C7 to promote closure of the B/C-ring juncture, and cascade termination by proton elimination from the beta-face of C5. CONCLUSIONS: These findings provide insight into the molecular architecture of the first dedicated step of taxol biosynthesis that creates the taxane carbon skeleton, and they have broad implications for the general mechanistic capability of the large family of terpenoid cyclization enzymes.

Effects of dopamine agonists and antagonists in Tourette's disease.

The actions of haloperidol, dextroamphetamine sulfate, levamfetamine succinate, apomorphine, and piribedil were studied in two patients with Giles de la Tourette's disease in an attempt to clarify the catecholamine mechanisms involved in this condition. Both dextroamphetamine and levamfetamine increased the severity of the symptoms; dextroamphetamine was more potent. Haloperidol controlled the symptoms and also antagonized the effect of dextroamphetamine. Apomorphine injections reduced the severity of symptoms, even in the presence of dextroamphetamine. We conclude that dopamine rather than norepinephrine is the principal catecholamine responsible for the symptoms. The effect of apomorphine may be understood through its action on postulated presynaptic inhibitory dopamine receptors, or other presynaptic mechanisms of action.

Biological 'markers' for endogenous depression. Effect of age, severity of illness, weight loss, and polarity.

The dexamethasone suppression test (DST) can differentiate between endogenous and nonendogenous depression. Similarly, EEG sleep patterns can differentiate primary from secondary depression, and this technique has also been used to make the endogenous-nonendogenous discrimination. However, a number of physiological variables associated with this diagnostic distinction may also affect the DST results and sleep architecture. With the use of multivariate statistical procedures, we found that although age and weight loss affect the results of both tests, both the DST and sleep EEG differentiate endogenous from nonendogenous depression when these variables are taken into account. Severity of illness affected both proposed diagnostic markers, but did not account for the differences between diagnostic groups, alone or when added to the physiological variables. The DST was more sensitive in unipolar than in bipolar endogenous depression, but there were no significant differences in the sleep of unipolar and bipolar patients.

Neuroendocrine regulation in depression. II. Discrimination of depressed from nondepressed patients.

Forty-two patients with endogenomorphic depression (ED) and 42 patients with other psychiatric disorders received an overnight dexamethasone test of hypothalamopituitary-adrenal (HPA) suppressibility. Plasma and urinary cortisol measures showed that the ED patients had significantly greater HPA activity before dexamethasone and less complete HPA suppression after dexamethasone. High cortisol vlaues after dexamethasone correlated strongly with spontaneous HPA disinhibition, as indicated by high baseline midnight plasma cortisol levels. Criteria for defining normal suppression responses were developed. All patients with depressive neuroses and most patients with other nondepressive disorders had completely normal responses to dexamethasone. About half of the ED patients had abnormal responses, whether or not they were receiving other drugs at the time of the test. Drug-free patients with depressive neuroses or other disorders showed no abnormal responses to dexamethasone. The effects of psychotropic drugs on the test require further study. Patients with two or more abnormal cortisol values after administration of dexamethasone were identified correctly as ED at confidence levels close to 100%. The dexamethasone suppression test may be of value as a laboratory aid in the diagnosis of "endogenous" depression.

A factor analysis of the signs and symptoms of mania.

BACKGROUND: No adequate factor analyses of signs and symptoms of mania have been reported. From limited past reports, the view has arisen that 2 main symptom clusters (euphoric-grandiose and paranoid-destructive) occur in patients with mania, along with so-called core symptoms of psychomotor pressure. In this view, dysphoric mania is associated with paranoid-destructive symptoms and with psychosis. METHODS: We rated 237 patients with DSM-III-R-defined bipolar disorder, manic (n = 204) or mixed (n = 33), on 15 classic features of mania and 5 features related to dysphoric mood. Principal components factor analysis was applied to the ratings. RESULTS: Five clearly interpretable and clinically relevant factors were identified. The first and strongest factor represented dysphoria in mania, with strong positive loadings for depressed mood, lability, guilt, anxiety, and suicidal thoughts and behaviors and a strong negative loading for euphoric mood. Factors 2 through 5 represented psychomotor acceleration, psychosis, increased hedonic function, and irritable aggression, respectively. The distribution of weighted scores on factor 1 was bimodal, whereas the corresponding distributions of factors 2 through 5 were unimodal. Contrary to all past reports, no general factor denoting overall severity of mania was found. Factors previously proposed by Beigel and Murphy were not confirmed. CONCLUSIONS: Five independent factors representing dysphoric mood, psychomotor pressure, psychosis, increased hedonic function, and irritable aggression were identified. The conventional view of symptom factors in mania was not confirmed. Dysphoric features are statistically salient in patients with mania, and the bimodal distribution of the dysphoria factor is consistent with the possibility that mixed bipolar disorder is a distinct state.

Serum dopamine-beta-hydroxylase activity in the affective psychoses and schizophrenia. Decreased activity in unipolar psychotically depressed patients.

Serum dopamine-beta-hydroxylase (DBH) activity was studied in 125 psychiatric patients and 73 normal controls. Serum DBH activity in schizophrenic, bipolar manic, and neurotic depressive patients was not significantly different from that in controls. Although serum DBH activity in unipolar and bipolar depressed patients was also not significantly different from that in controls, the subgroup of psychotically depressed unipolar patients had significantly lower serum DBH levels than controls did. Serum DBH activity in bipolar psychotically depressed patients also tended to be low, but was not significantly less than in controls. Serum DBH activity in the patient group usually did not increase in the immediate period following successful treatment with drugs or electroconvulsive therapy, indicating that basal levels of serum DBH activity in psychiatric patients are not state-dependent. Low serum DBH levels in psychotically depressed patients must be verified in an independent group of patients before its significance can be appreciated. Our findings could be the result of the study of an atypical group of psychotically depressed patients.

Hypothalamic-pituitary-adrenocortical activity in patients with diabetes mellitus.

Several clinical and physiologic associations between depression and diabetes mellitus have been reported. In this study, a potential neuroendocrine association was studied by measuring hypothalamic-pituitary-adrenocortical (HPA) axis activity in patients with diabetes mellitus. Plasma cortisol levels and response to dexamethasone administration were determined in 54 diabetics. Twenty-three (55%) of forty-two 1-mg dexamethasone suppression tests (DSTs) performed in 34 subjects, with eight repeated tests, and two (10%) of twenty 2-mg DSTs demonstrated a blunting of normal suppression. None of a variety of potential demographic, physiologic, or mood factors predicted nonsuppression. This study replicates prior findings that HPA dysfunction occurs in association with diabetes, and invalidates the use of the 1-mg DST as a diagnostic marker for melancholia in patients with diabetes.

Opioid regulation of hypothalamic-pituitary-adrenal function in depression.

A morphine infusion paradigm was used to investigate opioid mechanisms in the regulation of the hypothalamic-pituitary-adrenal (HPA) axis in depression. The subjects were unmedicated psychiatric inpatients and healthy volunteers. Morphine suppressed cortisol secretion. Early resumption of cortisol secretion was associated with a diagnosis of major depression and abnormal dexamethasone suppression test results. Our data suggest that the hyperactivity of the HPA axis observed in depression is abnormally resistant to opioid inhibition as well as glucocorticoid feedback.

Plasma cortisol determination for the dexamethasone suppression test. Comparison of competitive protein-binding and commercial radioimmunoassay methods.

Quality control serum samples and postdexamethasone plasma pools were used to compare 16 commercial cortisol radioimmunoassay kits with the competitive protein-binding assay for plasma glucocorticoids that we used to standardize the dexamethasone suppression test (DST). Thirteen radioimmunoassays gave higher criterion values for the DST than those established using the competitive protein-binding assay. The range of radioimmunoassay criterion values was 4.34 to 8.70 mu mg/dL. Possible explanations are given for these findings, and their importance to the clinical utility of the DST are emphasized. Each laboratory should validate its own criterion cortisol value for depression based on local data, including appropriate control groups.

Dexamethasone suppression tests in antidepressant treatment of melancholia. The process of normalization and test-retest reproducibility.

Pilot studies suggest that changes in response to the dexamethasone suppression test (DST) in melancholic patients receiving antidepressants might represent a laboratory marker of clinical progress. We performed weekly DSTs in 31 hospitalized patients with major depressive disorder, primary and endogenous subtypes, during drug-free and subsequent treatment periods. Most nonsuppressors had progressive normalization of DST responses in conjunction with clinical improvement, DST normalization usually preceded or coincided with good clinical response, and failure to normalize was often associated with poorer clinical outcome. Occasional patients with baseline dexamethasone suppression become nonsuppressive after withdrawal from medication, but the DST has no apparent value as a serial marker in patients with well-documented normal DST findings. Our results extend the construct validity of the DST as a state-related marker in nonsuppressors and suggest future clinical applications.

A specific laboratory test for the diagnosis of melancholia. Standardization, validation, and clinical utility.

Four hundred thirty-eight subjects underwent an overnight dexamethasone suppression test (DST) to standardize the test for the diagnosis of melancholia (endogenous depression). Abnormal plasma cortisol concentrations within 24 hours after dexamethasone administration occurred almost exclusively in melancholic patients. The best plasma cortisol criterion concentration, above which a DST result may be considered abnormal, was 5 microgram/dL. The optimal dose of dexamethasone was 1 rather than 2 mg. Two blood samples obtained at 4 and 11 PM after dexamethasone administration detected 98% of the abnormal test results. This version of the DST identified melancholic patients with a sensitivity of 67% and a specificity of 96%. Baseline nocturnal plasma cortisol concentrations were not useful. Abnormal DST results were found with similar frequency among outpatients and inpatients with melancholia; but they were not related to age, sex, recent use of psychotropic drugs, or severity of depressive symptoms. Extensive evidence validates this practical test for the diagnosis of melancholia.

A genome-wide association study of antidepressant response in Koreans.

We conducted a three-stage genome-wide association study (GWAS) of response to antidepressant drugs in an ethnically homogeneous sample of Korean patients in untreated episodes of nonpsychotic unipolar depression, mostly of mature onset. Strict quality control was maintained in case selection, diagnosis, verification of adherence and outcome assessments. Analyzed cases completed 6 weeks of treatment with adequate plasma drug concentrations. The overall successful completion rate was 85.5%. Four candidate single-nucleotide polymorphisms (SNPs) on three chromosomes were identified by genome-wide search in the discovery sample of 481 patients who received one of four allowed selective serotonin reuptake inhibitor (SSRI) antidepressant drugs (Stage 1). In a focused replication study of 230 SSRI-treated patients, two of these four SNP candidates were confirmed (Stage 2). Analysis of the Stage 1 and Stage 2 samples combined (n = 711) revealed GWAS significance (P = 1.60 × 10(-8)) for these two SNP candidates, which were in perfect linkage disequilibrium. These two significant SNPs were confirmed also in a focused cross-replication study of 159 patients treated with the non-SSRI antidepressant drug mirtazapine (Stage 3). Analysis of the Stage 1, Stage 2 and Stage 3 samples combined (n = 870) also revealed GWAS significance for these two SNPs, which was sustained after controlling for gender, age, number of previous episodes, age at onset and baseline severity (P = 3.57 × 10(-8)). For each SNP, the response rate decreased (odds ratio=0.31, 95% confidence interval: 0.20-0.47) as a function of the number of minor alleles (non-response alleles). The two SNPs significantly associated with antidepressant response are rs7785360 and rs12698828 of the AUTS2 gene, located on chromosome 7 in 7q11.22. This gene has multiple known linkages to human psychological functions and neurobehavioral disorders. Rigorous replication efforts in other ethnic populations are recommended.