Molecular targets of lithium action

Li-Doped Bioactive Ceramics: Promising Biomaterials for Tissue Engineering and Regenerative Medicine

Lithium (Li) is a metal with critical therapeutic properties ranging from the treatment of bipolar depression to antibacterial, anticancer, antiviral and pro-regenerative effects. This element can be incorporated into the structure of various biomaterials through the inclusion of Li chloride/carbonate into polymeric matrices or being doped in bioceramics. The biocompatibility and multifunctionality of Li-doped bioceramics present many opportunities for biomedical researchers and clinicians. Li-doped bioceramics (capable of immunomodulation) have been used extensively for bone and tooth regeneration, and they have great potential for cartilage/nerve regeneration, osteochondral repair, and wound healing. The synergistic effect of Li in combination with other anticancer drugs as well as the anticancer properties of Li underline the rationale that bioceramics doped with Li may be impactful in cancer treatments. The role of Li in autophagy may explain its impact in regenerative, antiviral, and anticancer research. The combination of Li-doped bioceramics with polymers can provide new biomaterials with suitable flexibility, especially as bio-ink used in 3D printing for clinical applications of tissue engineering. Such Li-doped biomaterials have significant clinical potential in the foreseeable future.

A case of dose-dependent lithium-induced tardive dyskinesia

Tardive dyskinesia (TD) is a serious side effect that manifests itself mainly with choreiform and athetotic movement disorders, and generally occurs in the long term during antipsychotic treatments and is generally irreversible. We report a 67-year-old female patient having a diagnosis of Bipolar Disorder (BD) for 25 years, receiving 1200 mg/day lithium monotherapy for 10 years and in remission. The patient had been showing signs of TD-like syndrome for the last 6 months. Because the patient responded to lithium well and because other treatment options for TD were unsuccessful, the lithium dose was reduced to 600 mg/day and the patient was monitored. Three months after the dose reduction, the patient's remission state continued, and the TD findings regressed. TD mainly due to antipsychotics is known as irreversible. This case suggests that lithium-induced TD may be reversible in a dose-dependent manner.

A distinct D1-MSN subpopulation down-regulates dopamine to promote negative emotional state

Dopamine (DA) level in the nucleus accumbens (NAc) is critical for reward and aversion encoding. DA released from the ventral mesencephalon (VM) DAergic neurons increases the excitability of VM-projecting D1-dopamine receptor-expressing medium spiny neurons (D1-MSNs) in the NAc to enhance DA release and augment rewards. However, how such a DA positive feedback loop is regulated to maintain DA homeostasis and reward-aversion balance remains elusive. Here we report that the ventral pallidum (VP) projection of NAc D1-MSNs (D1^NAc-VP) is inhibited by rewarding stimuli and activated by aversive stimuli. In contrast to the VM projection of D1-MSN (D1^NAc-VM), activation of D1^NAc-VP projection induces aversion, but not reward. D1^NAc-VP MSNs are distinct from the D1^NAc-VM MSNs, which exhibit conventional functions of D1-MSNs. Activation of D1^NAc-VP projection stimulates VM GABAergic transmission, inhibits VM DAergic neurons, and reduces DA release into the NAc. Thus, D1^NAc-VP and D1^NAc-VM MSNs cooperatively control NAc dopamine balance and reward-aversion states.

When should mood stabilizers be withdrawn due to lack of efficacy? Some methodological considerations

Maintenance therapy in bipolar disorder is primarily aimed at preventing recurrence of acute episodes. Clinicians often decide on the basis of their own experience whether mood stabilizer (MS) is properly satisfying the objective of preventing a relapse/recurrence. Evidence-based data seem far from clinical practice in assessing a MS efficacy, as they mainly focus on a drug's efficacy to first relapse and not considering the patient's course of illness. The problem of assessing MS's efficacy seems further complicated when considering combination therapy, which, due to lack of evidence-based data, economical aspects, attitude of clinicians and legal issues may bring to cumulative prescriptions. Nowadays, the drug therapy for a bipolar patient is usually tailored after longitudinal observation of his specific course of illness. The course of illness should be considered also when choosing practical criteria for the suspension of a MS due to lack of efficacy. The authors propose some preliminary criteria which may help clinicians evaluating whether a mood stabilizer is being useful or not, dividing possible outcomes and suggesting subsequent therapeutic steps in the optimization of a patient's treatment.

Dopamine D3 receptor and GSK3β signaling mediate deficits in novel object recognition memory within dopamine transporter knockdown mice

BACKGROUND

Over-stimulation of dopamine signaling is thought to underlie the pathophysiology of a list of mental disorders, such as psychosis, mania and attention-deficit/hyperactivity disorder. These disorders are frequently associated with cognitive deficits in attention or learning and memory, suggesting that persistent activation of dopamine signaling may change neural plasticity to induce cognitive or emotional malfunction.

METHODS

Dopamine transporter knockdown (DAT-KD) mice were used to mimic a hyper-dopamine state. Novel object recognition (NOR) task was performed to assess the recognition memory. To test the role of dopamine D₃ receptor (D₃R) on NOR, DAT-KD mice were treated with either a D₃R antagonist, FAUC365 or by deletion of D₃R. Total or phospho-GSK3 and -ERK1/2 signals in various brain regions were measured by Western blot analyses. To examine the impact of GSK3 signal on NOR, wild-type mice were systemically treated with GSK3 inhibitor SB216763 or, micro-injected with lentiviral shRNA of GSK3β or GSK3α in the medial prefrontal cortex (mPFC).

RESULTS

We confirmed our previous findings that DAT-KD mice displayed a deficit in NOR memory, which could be prevented by deletion of D₃R or exposure to FAUC365. In WT mice, p-GSK3α and p-GSK3β were significantly decreased in the mPFC after exposure to novel objects; however, the DAT-KD mice exhibited no such change in mPFC p-GSK3α/β levels. DAT-KD mice treated with FAUC365 or with D₃R deletion exhibited restored novelty-induced GSK3 dephosphorylation in the mPFC. Moreover, inhibition of GSK3 in WT mice diminished NOR performance and impaired recognition memory. Lentiviral shRNA knockdown of GSK3β, but not GSK3α, in the mPFC of WT mice also impaired NOR.

CONCLUSION

These findings suggest that D₃R acts via GSK3β signaling in the mPFC to play a functional role in NOR memory. In addition, treatment with D₃R antagonists may be a reasonable approach for ameliorating cognitive impairments or episodic memory deficits in bipolar disorder patients.

Lithium monotherapy-induced tardive dyskinesia

Tardive dyskinesia is a movement disorder that develops during the course of long-term treatment with neuroleptic agents and is characterized primarily by choreiform and athetotic movements. We report the case of a 68-year old female suffering from Bipolar disorder, treated with lithium monotherapy 600 mg per day (serum levels 0.6) for the last 15 years. While her response was favorable she was rarely visiting the outpatient clinic. Over the last few months she developed a tardive dyskinesia-like syndrome. To our knowledge this is the first reported case of tardive dyskinesia with lithium monotherapy at low dosages.

A Dynamical Bifurcation Model of Bipolar Disorder Based on Learned Expectation and Asymmetry in Mood Sensitivity

Bipolar disorder is a common psychiatric dysfunction characterized by recurring episodes of mania and depression. Despite its prevalence, the causes and mechanisms of bipolar disorder remain largely unknown. Recently, theories focusing on the interaction between emotion and behavior, including those based on dysregulation of the so-called behavioral approach system (BAS), have gained popularity. Mathematical models built on this principle predict bistability in mood and do not invoke intrinsic biological rhythms that may arise from interactions between mood and expectation. Here we develop and analyze a model with clinically meaningful and modifiable parameters that incorporates the interaction between mood and expectation. Our nonlinear model exhibits a transition to limit cycle behavior when a mood-sensitivity parameter exceeds a threshold value, signaling a transition to a bipolar state. The model also predicts that asymmetry in response to positive and negative events can induce unipolar depression/mania, consistent with clinical observations. We analyze the model with asymmetric mood sensitivities and show that large unidirectional mood sensitivity can lead to bipolar disorder. Finally, we show how observed effects of lithium- and antidepressant-induced mania can be explained within the framework of our proposed model.

Outer dense fibers stabilize the axoneme to maintain sperm motility

Outer dense fibers (ODFs), as unique accessory structures in mammalian sperm, are considered to play a role in the protection of the sperm tail against shear forces. However, the role and relevant mechanisms of ODFs in modulating sperm motility and its pathological involvement in asthenozoospermia were unknown. Here, we found that the percentage of ODF defects was higher in asthenozoospermic samples than that in control samples and was significantly correlated with the percentage of axoneme defects and non-motile sperm. Furthermore, the expression levels of ODF major components (Odf1, 2, 3, 4) were frequently down-regulated in asthenozoospermic samples. Intriguingly, the positive relationship between ODF size and sperm motility existed across species. The conditional disruption of Odf2 expression in mice led to reduced sperm motility and the characteristics of asthenozoospermia. Meanwhile, the expression of acetylated α-tubulin was decreased in sperm from both Odf2 conditional knockout (cKO) mice and asthenozoospermic men. Immunofluorescence and biochemistry analyses showed that Odf2 could bind to acetylated α-tubulin and protect the acetylation level of α-tubulin in HEK293T cells in a cold environment. Finally, we found that lithium elevated the expression levels of Odf family proteins and acetylated α-tubulin, elongated the midpiece length and increased the percentage of rapidly moving sperm in mice. Our results demonstrate that ODFs are beneficial for sperm motility via stabilization of the axoneme and that hypo-expression of Odf family proteins is involved in the pathogenesis of asthenozoospermia. The lithium administration assay will provide valuable insights into the development of new treatments for asthenozoospermia.

Comparative neurocognitive effects of lithium and anticonvulsants in long-term stable bipolar patients

BACKGROUND

The aim of choosing a mood-stabilizing drug (lithium or anticonvulsants) or a combination of them with minimal neurocognitive effects is to stimulate the development of criteria for a therapeutic adequacy, particularly in Bipolar Disorder (BD) patients who are clinically stabilized.

METHOD

Three groups of BD patients were established according to their treatment: (i) lithium monotherapy (n=29); (ii) lithium together with one or more anticonvulsants (n=28); and (iii) one or more anticonvulsants (n=16). A group of healthy controls served as the control (n=25). The following tests were applied: Wechsler Adult Intelligence Scale, Trail Making Test, Wechsler Memory Scale, Rey Complex Figure Test, Stroop color-word test, Wisconsin Card Sorting Test, Tower of Hanoi, Frontal Assessment Battery, and Reading the Mind in the Eyes Test.

RESULTS

Relative to healthy controls, BD patients showed the following: (i) those on lithium monotherapy, but not other BD groups, had preserved short-term auditory memory, long-term memory, and attention; (ii) those who took only anticonvulsants showed worse findings in short-term visual memory, working memory, and several executive functions; and (iii) all BD patients showed worse performance in processing speed, resistance to interference, and emotion recognition.

LIMITATIONS

Medication alone cannot explain why all BD patients showed common cognitive deficits despite different pharmacological treatment.

CONCLUSION

The impairment on some executive functions and emotion recognition is an inherent trait in BD patients, regardless of their pharmacological treatment. However, while memory, attention, and most of the executive functions are preserved in long-term stable BD patients, these cognitive functions are impaired in those who take anticonvulsants.

Antiviral effect of lithium chloride on feline calicivirus in vitro

Feline calicivirus (FCV) is a highly contagious pathogen that causes oral and upper respiratory tract disease in cats. Despite widespread vaccination, the prevalence of FCV remains high. Furthermore, a high gene mutation rate has led to the emergence of variants, and some infections are lethal. To date, there is no effective antiviral drug available for treating FCV infection. Here, we show that lithium chloride (LiCl) effectively suppresses the replication of FCV strain F9 in Crandell-Reese feline kidney (CRFK) cells. The antiviral activity of LiCl occurred primarily during the early stage of infection and in a dose-dependent manner. LiCl treatment also inhibited the cytopathic effect. LiCl treatment exhibited a strong inhibitory effect against a panel of other two reference strains and two recent FCV isolates from China. These results demonstrate that LiCl might be an effective anti-FCV drug for controlling FCV disease. Further studies are required to explore the antiviral activity of LiCl against FCV replication in vivo.

(1)H NMR-based metabolomics investigation of Daphnia magna responses to sub-lethal exposure to arsenic, copper and lithium

Metal and metalloid contamination constitutes a major concern in aquatic ecosystems. Thus it is important to find rapid and reliable indicators of metal stress to aquatic organisms. In this study, we tested the use of (1)H nuclear magnetic resonance (NMR) - based metabolomics to examine the response of Daphnia magna neonates after a 48h exposure to sub-lethal concentrations of arsenic (49μgL(-1)), copper (12.4μgL(-1)) or lithium (1150μgL(-1)). Metabolomic responses for all conditions were compared to a control using principal component analysis (PCA) and metabolites that contributed to the variation between the exposures and the control condition were identified and quantified. The PCA showed that copper and lithium exposures result in statistically significant metabolite variations from the control. Contributing to this variation was a number of amino acids such as: phenylalanine, leucine, lysine, glutamine, glycine, alanine, methionine and glutamine as well as the nucleobase uracil and osmolyte glycerophosphocholine. The similarities in metabolome changes suggest that lithium has an analogous mode of toxicity to that of copper, and may be impairing energy production and ionoregulation. The PCA also showed that arsenic exposure resulted in a metabolic shift in comparison to the control population but this change was not statistically significant. However, significant changes in specific metabolites such as alanine and lysine were observed, suggesting that energy metabolism is indeed disrupted. This research demonstrates that (1)H NMR-based metabolomics is a viable platform for discerning metabolomic changes and mode of toxicity of D. magna in response to metal stressors in the environment.

Lithium attenuates peripheral neuropathy induced by paclitaxel in rats

As a cancer chemotherapeutic agent, paclitaxel (Taxol® ) causes dose-related peripheral neuropathy in human beings. The mechanisms underlying this toxicity are currently unknown, and there are no validated treatments for its prevention or control. To assess whether lithium as a pre-treatment and at subtherapeutic dose could prevent the peripheral neuropathy produced by it, rats were treated with paclitaxel (2 mg/kg i.p. every other day for a total of 16 times) and/or lithium chloride (300 mg/l) via water supply. General toxicity and body-weight were measured regularly during the experiment. To evaluate the sensory and motor neuropathy hot-plate, open-field test and nerve conduction velocity were used. In rats treated with only paclitaxel, there was behavioural, electrophysiological and histological evidence of a mixed sensorimotor neuropathy after 16 injections. Lithium robustly reduced the rate of mortality and general toxicity. Paclitaxel-induced sensorimotor neuropathy was significantly improved as indicated by changes in hotplate latency, total distance moved and a significant increase in sciatic, sural and tail sensory or motor nerve conduction velocity. The same results were observed in histopathological examinations; however, dorsal root ganglion neurons did not significantly change in the paclitaxel-treated groups. These results suggest that lithium, at subtherapeutic doses, can prevent both motor and sensory components of paclitaxel neuropathy in rats. Thus, lithium at these doses, as an inexpensive and relatively safe salt, may be useful clinically in preventing the neuropathy induced by paclitaxel treatment.

Treatment of psychotic symptoms in bipolar disorder with aripiprazole monotherapy: a meta-analysis

BACKGROUND

We present a systematic review and meta-analysis of the available clinical trials concerning the usefulness of aripiprazole in the treatment of the psychotic symptoms in bipolar disorder.

METHODS

A systematic MEDLINE and repository search concerning clinical trials for aripiprazole in bipolar disorder was conducted.

RESULTS

The meta-analysis of four randomised controlled trials (RCTs) on acute mania suggests that the effect size of aripiprazole versus placebo was equal to 0.14 but a more reliable and accurate estimation is 0.18 for the total Positive and Negative Syndrome Scale (PANSS) score. The effect was higher for the PANSS-positive subscale (0.28), PANSS-hostility subscale (0.24) and PANSS-cognitive subscale (0.20), and lower for the PANSS-negative subscale (0.12). No data on the depressive phase of bipolar illness exist, while there are some data in favour of aripiprazole concerning the maintenance phase, where at week 26 all except the total PANSS score showed a significant superiority of aripiprazole over placebo (d = 0.28 for positive, d = 0.38 for the cognitive and d = 0.71 for the hostility subscales) and at week 100 the results were similar (d = 0.42, 0.63 and 0.48, respectively).

CONCLUSION

The data analysed for the current study support the usefulness of aripiprazole against psychotic symptoms during the acute manic and maintenance phases of bipolar illness.

Temporal Variation in Drug Interaction Between Lithium and Morphine‐Induced Analgesia

The administration-time-dependent aspects of the drug interaction between lithium and morphine-induced analgesia were studied using the mouse hot-plate test at six different times of day, each scheduled at 4 h intervals. Lithium treatment alone, in doses of 1 to 10 mmol/kg administered intraperitoneally (i.p.) did not significantly alter test latencies compared to the corresponding clock-time in saline-injected controls. Basal pain sensitivity and morphine-induced antinociceptive activity displayed significant circadian rhythms as assessed by the hot-plate response latencies, with higher values occurring during the nocturnal activity than during the daytime rest span. Acute administration of lithium, in a dose of 3 mmol/kg, 30 min prior to morphine dosing did not influence morphine-induced analgesia compared to all the clock-time test-matched morphine groups, except the 9 HALO (Hours After Lights On) one. There was a prominent potentiation of the morphine-induced antinociception at this biological time during combined drug treatment. The latter finding demonstrates that administration-time-dependent differences in drug-drug interactions need to be considered in both experimental designs and clinical settings.

Cytoprotective effect of lithium against spontaneous and induced apoptosis of lymphoid cell line MOLT-4

Lithium (Li) is still useful in the treatment of bipolar disorder. Cellular mechanisms of Li action are not fully understood and include some cytoprotective properties. Data concerning Li effect on the apoptotic mechanisms in cells other than neurons are fragmentary and contradictory. We have investigated anti-apoptotic activity of Li in a lymphoid derived MOLT-4 cell line. Spontaneous and camptothecin-induced apoptosis was analyzed in cells treated with 0-20 mM Li carbonate. Early apoptosis was identified as significant mitochondrial depolarization (JC-1 staining). Later stages of apoptosis were estimated with annexin V binding and by the proportion of cells containing sub-G1 amounts of DNA (PI staining). We have observed a biphasic effect of Li on the proportion of spontaneously apoptotic cells;namely, low (therapeutic) concentrations of Li had a significant effect stabilizing the mitochondrial membrane polarization, while 10 and 20mM Li increased apoptosis. The latter could be seen both as mitochondrial depolarization as well as an increased proportion of sub-G1 cells, accompanied by reduced proportion of S phase cells. Li at concentrations above 2 mM had a significant, dose-dependent, anti-apoptotic effect on the cells undergoing camptothecin induced apoptosis. In conclusion, demonstrated cytoprotective effect of Li is at least partially related to stabilization of mitochondrial membrane potential and to the reduction of DNA damaging effects in proliferating cells; both may form part of the mechanism through which Li is useful in therapy of bipolar disorder, but may have more general consequences.

A systematic review of existing data on long-term lithium therapy: neuroprotective or neurotoxic?

Lithium is an efficacious agent for the treatment of bipolar disorder, but it is unclear to what extent its long-term use may result in neuroprotective or toxic consequences. Medline was searched with the combination of the word 'Lithium' plus key words that referred to every possible effect on the central nervous system. The papers were further classified into those supporting a neuroprotective effect, those in favour of a neurotoxic effect and those that were neutral. The papers were classified into research in humans, animal and in-vitro research, case reports, and review/opinion articles. Finally, the Natural Standard evidence-based validated grading rationale was used to validate the data. The Medline search returned 970 papers up to February 2006. Inspection of the abstracts supplied 214 papers for further reviewing. Eighty-nine papers supported the neuroprotective effect (6 human research, 58 animal/in vitro, 0 case reports, 25 review/opinion articles). A total of 116 papers supported the neurotoxic effect (17 human research, 23 animal/in vitro, 60 case reports, 16 review/opinion articles). Nine papers supported no hypothesis (5 human research, 3 animal/in vitro, 0 case reports, 1 review/opinion articles). Overall, the grading suggests that the data concerning the effect of lithium therapy is that of level C, that is 'unclear or conflicting scientific evidence' since there is conflicting evidence from uncontrolled non-randomized studies accompanied by conflicting evidence from animal and basic science studies. Although more papers are in favour of the toxic effect, the great difference in the type of papers that support either hypothesis, along with publication bias and methodological issues make conclusions difficult. Lithium remains the 'gold standard' for the prophylaxis of bipolar illness, however, our review suggests that there is a rare possibility of a neurotoxic effect in real-life clinical practice even in closely monitored patients with 'therapeutic' lithium plasma levels. It is desirable to keep lithium blood levels as low as feasible with prophylaxis.

Physiological and biochemical effects of lithium in rainbow trout

The physiological responses of juvenile rainbow trout (Oncorhynchus mykiss) to lithium (as LiCl) in moderately hard freshwater (CaCO(3) = 120-140 ppm, Na(+) = approximately 0.6 mM) were studied. The study employed a 15-day step-up exposure regime; 66 microg/L Li for the first 9 days and 528 microg/L for the next 6 days. The concentrations of plasma ions, apolipoprotein AI, total cholesterol, and fatty acids, as well as metabolic enzyme citrate synthase (CS) and Na(+),K(+)-ATPase activities in the gill were measured. Li affected fish by exacerbated diffusive Na(+) losses at the gills in the beginning of exposure and a decrease of branchial CS activity. Detrimental effects were shown in fish exposed to 528 microg Li/L. These included a reduction of gill Na(+),K(+)-ATPase activity, possibly related to observed lower concentrations of free fatty acids and cholesterol in gill tissue.

Prefrontal gray matter increases in healthy individuals after lithium treatment: a voxel-based morphometry study

The objective of this study was to test the hypothesis that 4 weeks of lithium administration would be associated with changes in brain gray and white matter volumes in healthy individuals. Thirteen right-handed healthy volunteers (6 females, mean age=25.9+/-10.0 years) were studied. 3D SPGR MRIs (TR=25 ms, TE=5 ms, slice-thickness=1.5 mm) were acquired using a 1.5 T GE Signa Imaging System, at baseline and after 4 weeks of lithium administration at therapeutically relevant doses. Optimized voxel-based morphometry (VBM) analyses were conducted. Left and right dorsolateral prefrontal cortex and left anterior cingulate gray matter volumes increased significantly following lithium administration. Total white matter volume was increased, whereas total brain volume and total gray matter volume were not significantly changed following 4 weeks of lithium. Lithium treatment resulted in prefrontal regional gray matter volume increases in healthy volunteers, as well as increases in total white matter volume. Whether these changes are mediated by neurotrophic/neuroprotective or osmotic effects remains unknown.

Restraint stress influences AP-1 and CREB DNA-binding activity induced by chronic lithium treatment in the rat frontal cortex and hippocampus

The therapeutic efficacy of mood stabilizers may involve the regulation of gene expression mediated by transcription factor activation. In this study, we investigated AP-1 and cAMP response element-binding protein (CREB) DNA-binding activity in the rat frontal cortex and hippocampus of rats fed a control diet, a lithium diet for 7 wk, or 6 wk of lithium, followed by withdrawal for 7 d. Subsequently, animals were exposed to restraint stress or no stress and the DNA-binding activities assessed at 2, 8 and 24 h post-stress. AP-1 activity was increased in both brain regions by lithium, an effect that persisted with lithium discontinuation. Restraint stress induced AP-1 activity in the frontal cortex of the control group. This stress-induced effect on AP-1 activity was attenuated in lithium-treated and lithium-withdrawn animals. AP-1 DNA binding was also induced by stress in the hippocampus of control animals and the activity diminished over time in the lithium and lithium-withdrawn groups. CREB activity also increased in the frontal cortex and hippocampus of the lithium-treated group. Stress increased CREB activity in the frontal cortex of the controls, and was slightly attenuated with lithium treatment. CREB activity in the hippocampus was insensitive to stress. The proteins involved in the AP-1 and CREB transcription complexes were also characterized. Our findings of increased AP-1 and CREB binding after lithium are consistent with lithium's inhibitory effect on glycogen synthase kinase-3beta, which has been show to negatively regulate AP-1 and CREB transcriptional activity.

Inhibitors of brain phospholipase A2 activity: their neuropharmacological effects and therapeutic importance for the treatment of neurologic disorders

The phospholipase A(2) family includes secretory phospholipase A(2), cytosolic phospholipase A(2), plasmalogen-selective phospholipase A(2), and calcium-independent phospholipase A(2). It is generally thought that the release of arachidonic acid by cytosolic phospholipase A(2) is the rate-limiting step in the generation of eicosanoids and platelet activating factor. These lipid mediators play critical roles in the initiation and modulation of inflammation and oxidative stress. Neurological disorders, such as ischemia, spinal cord injury, Alzheimer's disease, multiple sclerosis, prion diseases, and epilepsy are characterized by inflammatory reactions, oxidative stress, altered phospholipid metabolism, accumulation of lipid peroxides, and increased phospholipase A(2) activity. Increased activities of phospholipases A(2) and generation of lipid mediators may be involved in oxidative stress and neuroinflammation associated with the above neurological disorders. Several phospholipase A(2) inhibitors have been recently discovered and used for the treatment of ischemia and other neurological diseases in cell culture and animal models. At this time very little is known about in vivo neurochemical effects, mechanism of action, or toxicity of phospholipase A(2) inhibitors in human or animal models of neurological disorders. In kainic acid-mediated neurotoxicity, the activities of phospholipase A(2) isoforms and their immunoreactivities are markedly increased and phospholipase A(2) inhibitors, quinacrine and chloroquine, arachidonyl trifluoromethyl ketone, bromoenol lactone, cytidine 5-diphosphoamines, and vitamin E, not only inhibit phospholipase A(2) activity and immunoreactivity but also prevent neurodegeneration, suggesting that phospholipase A(2) is involved in the neurodegenerative process. This also suggests that phospholipase A(2) inhibitors can be used as neuroprotectants and anti-inflammatory agents against neurodegenerative processes in neurodegenerative diseases.

A pilot study of hormone modulation as a new treatment for mania in women with bipolar affective disorder

We tested and compared the use of two adjunctive hormonal agents, tamoxifen and medroxyprogesterone acetate (MPA), for the treatment of acute mania or hypomania. A total of 13 women with acute Bipolar Affective Disorder in the manic or hypomanic phase were recruited from a clinical population to participate in this 28-day, three-arm, double blind, placebo-controlled study. The women who received tamoxifen exhibited significant improvement in symptoms of mania from baseline to final assessment compared with the placebo group. The MPA group improved more than the placebo group. Further exploration of tamoxifen as a useful adjunct in the treatment of acute manic symptoms in women with Bipolar Affective Disorder is warranted.