Improved radioimmunodetection of carcinomas with a re-injection of monoclonal antibodies after formation of anti-mouse antibodies.

Scintigraphic imaging was satisfactory in animal experiments, i.e., in the radioimmunodetection with 125J anti-tissue polypeptide antigen monoclonal antibodies and implanted HELA cell carcinomas. Unlabeled anti-mouse antibodies (AMAB), in a surplus of 40:1, 200:1 and 4000:1 compared to the radioactive antibody, were administered five days after administering the 125I anti-TPA antibody (RAAB). In immunoscintigraphies, radioactivity accumulated in the liver immediately after administering the secondary antibody, and the tumor's imaging worsened. It can be expected that imunoscintigraphic imaging might improve when radioimmunodetection is re-performed after the formation of human anti-mouse antibodies (AMAB) and when the ratio of the primary to the secondary antibody is nearly equivalent because, in this ratio, the formation of immune complexes might be accelerated. It is possible to measure the quantity of formed anti-mouse antibodies (AMAB) with immunography measurements. A second administration of diagnostic or therapeutic monoclonal antibodies might lead to the formation of immune complexes if the quantities of the monoclonal antibodies and the anti-mouse antibodies have an equivalent ratio. A second performance of the radioimmunodetection four to eight weeks after the first radioimmunodetection can achieve better tumor imaging because human anti-mouse antibodies (AMAB) can be formed. Immune complexes of the radioactive antibody and the human anti-mouse antibody (AMAB) can be formed to concentrate radioactivity in the tumor.

Risk Genes in Schizophrenia and Their Importance in Choosing the Appropriate Antipsychotic Treatment.

BACKGROUND: Schizophrenia is a chronic mental illness that in 80% of cases has a genetic etiology. In the last years, 260 risk genes with a predisposition to schizophrenia have been discovered and correlations between risk genes and the therapeutic efficacy of an antipsychotic treatment/pharmacotherapy resistance have been reported. OBJECTIVE: The objective of this review is to update the main risk genes involved in schizophrenia and to establish an association between the single nucleotide polymorphisms (SNPs) of these genes and pharmacotherapy resistance/efficacy of a determined antipsychotic treatment. Besides, neural networks in the brain centers involved in schizophrenia will be updated to point out the altered functions of classical neurotransmitters and neuropeptides due to risk genes. METHODS: In schizophrenia, important risk genes, such as catechol-O-methyl transferase (COMT), monoamine oxidase (MAO A/B), glutamic acid decarboxylase 67 (GAD 67), dysbindin-1 and neuregulin-1 will be mentioned. To describe the function of these risk genes, neural networks in the ventral tegmental area, hippocampus and prefrontal cortex will also be developed. RESULTS: An association between the SNPs of some risk genes and the efficacy of an antipsychotic treatment is reported: SNPs such as rs165599 (COMT gene), rs1801028 (D2 receptor gene) and rsSer9Gly (D3 receptor gene) are associated with a better antipsychotic treatment efficacy (e.g., treatment of negative schizophrenic symptoms with risperidone). The rs4680 SNP (COMT and D2 receptor genes) is associated with antipsychoticinduced dopamine hypersensitivity and pharmacotherapy resistance. The function of risk genes is described: COMT and MAO A/B genes, with reduced activity in the corresponding enzymes, are associated with a decrease in dopamine degradation and hence dopamine hyperactivity occurred via D2 receptors. The GAD 67 risk gene is linked with GABAergic dysfunction and consequently GABAergic neurons weakly presynaptically inhibit D2 dopaminergic neurons. The D-amino acid oxidase activator (DAOA) risk gene is connected with glutamatergic dysfunction via NMDA receptors. Glutamatergic neurons might exert a weak presynaptic inhibition upon 5- HT2A serotonergic neurons located in the ventral tegmental area and hippocampus. Neural networks in the latter two regions and in the prefrontal cortex are updated. CONCLUSION: It is important to examine the SNPs of the risk genes involved in schizophrenia to establish a correlation between these SNPs and the efficacy of a determined antipsychotic drug. In the future, after examining these SNPs, it might be possible to choose the most appropriate antipsychotic drug. Thus, schizophrenic patients with a good response to a determined antipsychotic treatment and patients with resistance to this treatment could be well differentiated.

The Novel Antipsychotic Drug Cariprazine and Cognition Enhancing Drugs: Indications for their Use as the Add-on Therapy in Schizophrenia.

BACKGROUND: Schizophrenia and schizoaffective disorder are treated with antipsychotic drugs. Some patients show treatment-resistant forms of psychotic disorders, and in this case, they can be treated with clozapine. Based on the previous reviews on novel antipsychotic drugs, it is important to know whether the add-on therapy with the new drugs can ameliorate the positive and negative schizophrenic scale (PANSS) total score. OBJECTIVES: The aim of this review is to suggest an appropriate treatment for patients with treatment-resistant forms of psychotic disorders. A combination of the currently available antipsychotic drugs with novel antipsychotic or modulating drugs might improve negative schizophrenic symptoms and cognitive function and thereby social functioning and quality of life. RESULTS: The mechanisms of action, the therapeutic effects, and the pharmacokinetic profiles of novel antipsychotic drugs such as cariprazine, brexipiprazole, and lumateperone have been updated. Published case reports of patients with treatment-resistant psychoses have also been discussed in this study. These patients were treated only with clozapine, as a result of which a high PANSS total score was observed. Only the add-on therapy with cariprazine improved the score, and above all, the negative schizophrenic symptoms and cognitive functions were improved. For the ensurance of a constant antipsychotic drug concentration, long-acting injectable antipsychotic drugs might be a choice for the maintenance therapy in schizophrenia. New modulating drugs, such as receptor positive allosteric modulators (N-methyl-D-aspartate receptor; subtype 5 of the metabotropic glutamatergic receptor) and encenicline, an alpha7 nicotinic cholinergic receptor agonist, have been investigated in preclinical and clinical trials. CONCLUSION: In clinical trials, patients with treatment-resistant forms of psychosis should be examined to know whether combination therapy with clozapine and a novel antipsychotic drug can ameliorate the PANSS total score. In schizophrenia, long-acting injectable antipsychotic drugs are safe and tolerable maintenance therapy. In further clinical studies, it should be investigated whether patients with treatment-resistant forms of psychoses can improve negative schizophrenic symptoms and cognitive functions by the add-on therapy with cognitionenhancing drugs.

Therapeutic Effect of Novel Antidepressant Drugs Acting at Specific Receptors of Neurotransmitters and Neuropeptides.

BACKGROUND: Major depression is a frequent psychiatric disease. One- third of the depressive patients remain treatment-resistant; thus, it is urgent to find novel antidepressant drugs. OBJECTIVE: In major depression, in several brain areas the neural networks involved and the alterations of neurotransmitters and neuropeptides are updated. According to these networks, new pharmacological agents and effective combinations of antidepressant drugs achieving a more efficacious antidepressant treatment are suggested. RESULTS: In the neural networks, the prefrontal cortex has been included. In this brain area, glutamatergic neurons, which receive an activating potential from D2 dopaminergic neurons, presynaptically inhibit M1 muscarinic cholinergic neurons via NMDA receptors. Medium spiny GABAergic/somatostatin neurons, which receive projections from M1 muscarinic cholinergic neurons, presynaptically inhibit D2 dopaminergic neurons via GABAA/somatostatin1 receptors. The combination of an NMDA receptor antagonist with an M1 muscarinic cholinergic receptor antagonist can achive a rapid, long-lasting antidepressant effect. CONCLUSION: In preclinical studies, the antidepressant effect of orvepitant, an NK1 receptor antagonist, has been demonstrated: this antagonist reaches a complete blockade of NK1 receptors. In clinical studies, the combination of an NMDA receptor antagonist with an M1 muscarinic cholinergic receptor antagonist should be investigated indepth as well as the therapeutic effect of orvepitant. In clinical studies, the antidepressant effect of a triple reuptake inhibitor should be examined and compared to current antidepressant drugs.

Neural Networks in Generalized Epilepsy and Novel Antiepileptic Drugs.

BACKGROUND: In previous works, alterations of neurotransmitters and neuropeptides in the brain areas involved in generalized epilepsy have been reported. OBJECTIVE: We reviewed the alterations of these neurotransmitters and neuropeptides in the following brain areas involved in generalized epilepsy: hippocampus, hypothalamus, thalamus and cerebral cortex. In these brain areas, the neural networks are also actualized. The mechanisms of action of newer antiepileptic drugs in the treatment of generalized epilepsy are also discussed. RESULTS: Up-dating the neurotransmitter and neuropeptide alterations, we found that hippocampal GABAergic neurons presynaptically inhibit epileptogenic neurons via GABAB receptors. Epilepsy modulating neuropeptides (galanin, neuropeptide Y, dynorphin) are also involved. GABA deficiency, serotonin hyperactivity, dopamine hyperactivity and glutamate excitotoxicity can enhance ictogenesis: neurons containing these neurotransmitters form the main neural circuit. An increased excitability occurs when the alteration of these neurotransmitters is permanent. CONCLUSION: In preclinical studies, the GABAB receptor agonist GS 39,783 exerted a good antiepileptic effect. Perampanel, an AMPA receptor antagonist, showed good clinical effects in the treatment of partial-onset seizures and primary generalized tonic-clonic seizures. In this treatment, perampanel can be combined with other antiepileptic drugs. Brivaracetam, which shows a high affinity for the synaptic vesicle 2A, exerted a good efficacy in the treatment of adult focal seizures and secondarily generalized tonic-clonic seizures.

Long-term Administration of Antipsychotic Drugs in Schizophrenia and Influence of Substance and Drug Abuse on the Disease Outcome.

BACKGROUND: Many schizophrenic patients with a long-term administration of antipsychotic drugs do not regularly adhere to the prescribed pharmacotherapy. Antipsychotic drugs constitute a palliative, but not a curative treatment, and the long-term effect of these drugs is not secure. Patients tend to consume nicotine and alcohol, as well as some patients consume drugs such as cannabis and amphetamines. OBJECTIVE: The objective of this mini-review is to examine the reasons for the high tendency of schizophrenic patients to consume alcohol, nicotine and drugs and in addition to suggest measures to reduce the abuse of substances and drugs. The effects of substances such as alcohol and nicotine and drugs such as cannabis and amphetamines on the disease outcome will be mentioned. METHOD: Previous reviews on the psychotic disorders and the pharmacological treatment were used to examine the effects of substances and drugs on schizophrenic symptoms and to investigate appropriate measures to improve medication adherence and the renouncement of consuming substances and drugs. RESULTS: A possible coherence between the function of single susceptibility genes and the alteration of neurotransmitters is mentioned. The mechanism of action of the most important secondgeneration antipsychotic drugs and their indications are described. The tendency of schizophrenic patients to consume alcohol and nicotine and in addition the effect of both substances to possibly worsen psychotic symptoms are pointed out. The effect of nicotinergic agonists to support smoking cessation is described. The different compounds of cannabis, tetrahydrocannabidiol (a psychotomimetic) and cannabidiol (exerts antipsychotic actions), are mentioned. Because a reduced adherence to the pharmacotherapy is frequently combined with the abuse of substances, additional drugs, psychoeducation and the administration of long-acting injectable antipsychotic drugs could reduce the abuse of substances and drugs; these strategies could help to maintain the antipsychotic administration. CONCLUSION: The abuse of drugs and substances might be combined with a reduced adherence to the antipsychotic pharmacotherapy. Drugs and substances might in some cases worsen the psychotic symptoms. Appropriate measures to reduce substance and drug abuse as well as to improve the adherence to the antipsychotic pharmacotherapy are cognitive behavioral therapy, psychoeducation and the administration of long-acting injectable antipsychotic drugs. Some new drugs, for example the cannabis compound cannabidiol that shows antipsychotic properties and ß-varenicline, a nicotinergic cholinergic agonist, might be administered when substance abuse (cannabis, nicotine) occurs.

Classical neurotransmitters and neuropeptides involved in generalized epilepsy in a multi-neurotransmitter system: How to improve the antiepileptic effect?

Here, we describe in generalized epilepsies the alterations of classical neurotransmitters and neuropeptides acting at specific subreceptors. In order to consider a network context rather than one based on focal substrates and in order to make the interaction between neurotransmitters and neuropeptides and their specific subreceptors comprehensible, neural networks in the hippocampus, thalamus, and cerebral cortex are described. In this disease, a neurotransmitter imbalance between dopaminergic and serotonergic neurons and between presynaptic GABAergic neurons (hypoactivity) and glutaminergic neurons (hyperactivity) occurs. Consequently, combined GABAA agonists and NMDA antagonists could furthermore stabilize the neural networks in a multimodal pharmacotherapy. The antiepileptic effect and the mechanisms of action of conventional and recently developed antiepileptic drugs are reviewed. The GASH:Sal animal model can contribute to examine the efficacy of antiepileptic drugs. The issues of whether the interaction of classical neurotransmitters with other subreceptors (5-HT7, metabotropic 5 glutaminergic, A2A adenosine, and alpha nicotinic 7 cholinergic receptors) or whether the administration of agonists/antagonists of neuropeptides might improve the therapeutic effect of antiepileptic drugs should be addressed. This article is part of a Special Issue entitled "Genetic and Reflex Epilepsies, Audiogenic Seizures and Strains: From Experimental Models to the Clinic".

Serotonergic Drugs: Agonists/Antagonists at Specific Serotonergic Subreceptors for the Treatment of Cognitive, Depressant and Psychotic Symptoms in Alzheimer's Disease.

BACKGROUND: Alzheimer's disease is a neurodegenerative disease showing alterations in classical neurotransmitters, above all in the hippocampus and prefrontal/temporal cortices. In this disease, acetylcholine shows hypoactivity, noradrenaline first shows hyperactivity, and during the course of the disease an increasing hypoactivity, glutamate shows hyperactivity and excitotoxicity and GABA shows hypoactivity. In post-mortem studies, serotonin levels and the number of specific serotonergic subreceptors, for example 5-HT1B receptors, decreased. METHODS: We summarized the alterations of classical neurotransmitters in the brain regions involved in cognitive, depressive and psychotic symptoms in Alzheimer's disease. Starting from these neurotransmitter alterations, we describe neural networks including specific serotonergic subreceptors in the involved brain regions. RESULTS: In the hippocampus and prefrontal cortex, serotonin levels are associated with cognitive functions, whereas in the brainstem serotonin levels are related with affective symptoms. Psychotic symptoms which can occur in patients with Alzheimer's disease are associated with dopamine and serotonin hyperactivity in the mesolimbic system and hippocampus. The interaction between classical neurotransmitters and their specific subreceptors is shown in different brain areas. CONCLUSION: In clinical trials, the therapeutic effects of 5-HT4, 5-HT7 agonists and 5-HT3, 5-HT6 antagonists have been examined to improve cognitive symptoms in Alzheimer's disease. In these trials, 5-HT4 agonists and 5-HT4 antagonists showed a significant better effect in improving cognitive functions than placebo. The effect of such drugs on the formation of amyloid plaques is also examined. The appropriate use of antidepressant and antipsychotic drugs with an agonism or antagonism at specific serotonergic subreceptors is pointed out. Serotonin-selective antidepressant drugs significantly improve depressant symptoms and daily activities in Alzheimer patients and they are used to treat aggressive behaviour. Among the second-generations antipsychotic drugs (D2 and 5-HT2A antagonists), drugs with a favorable metabolic profile should be used.

New developments in the management of schizophrenia and bipolar disorder: potential use of cariprazine.

Cariprazine is a recently developed antipsychotic drug with a partial agonism for the D2 and D3 receptors. It shows a tenfold greater affinity for the D3 receptor. In clinical trials, its therapeutic effect has been tested in patients with an acute exacerbation of schizophrenia and in patients with acute mania in bipolar disorder. Like risperidone, cariprazine improves positive and negative schizophrenic symptoms, and ameliorates cognitive functions. Cariprazine induces extrapyramidal symptoms less often than risperidone and can cause acute akathisia. It is a prolactin-sparing antipsychotic drug and has a favorable metabolic profile. In acute mania in bipolar disorder, it treats manic symptoms significantly better than placebo. As a consequence of its improved adverse effects, cariprazine improves patients' quality of life to a greater extent than other second-generation antipsychotic drugs. Cariprazine is a promising antipsychotic drug in the treatment of schizophrenia, acute mania in bipolar disorder, and in schizophrenia with mania. In these patients, its long-term therapeutic effect and its action in comparison with other second-generation antipsychotic drugs, above all aripiprazole, remain to be tested in clinical trials.

Methicillin-Resistant Staphylococcus aureus: Treatment with Cultures of Non Drug-Resistant Staphylococcus epidermidis.

The colonization and infection with methicillin-resistant Staphylococcus aureus is a major health problem in hospitals and long-term care facilities. Although bacteriaemias with MRSA (methicillin-resistant Staphylococcus aureus) can be treated with vancomycin and other reserve antibiotics, 20% of patients cannot be successfully cured. Inpatients colonized with MRSA are isolated in hospitals according to the guidelines of the Robert-Koch-Institute, although in long-term care facilities these patients are not urgently isolated. Active decolonization measures are taken to eradicate colonization with MRSA. In order to reduce MRSA colonization, it could be possible to administer cultures of Staphylococcus epidermidis which have no antibiotic resistance, so that physiological genes could be conferred from Staphylococcus epidermidis to MRSA bacteria.

Methicillin-resistant Staphylococcus aureus: treatment with cultures of not drug-resistant Staphylocuccus epidermidis.

The colonization and infection with methicillin-resistant Staphylococcus aureus is a major health problem in hospitals and long-term care facilities. Although bacteriaemias with MRSA (methicillin-resistant Staphylococcus aureus) can be treated with vancomycin and other reserve antibiotics, 20% of patients cannot be successfully cured. Inpatients colonized with MRSA are isolated in hospitals according to the guidelines of the Robert-Koch-Institute, althouth in long-term care facilities these patients are not urgently isolated. Active decolonization measures are taken to eradicate colonization with MRSA. In order to reduce MRSA colonization, it could be possible to administer cultures of Staphylococcus epidermidis which have no anbitiotic resistance, so that physiological genes could be conferred from Staphylococcus epidermis to MRSA bacteria.

Safety of antipsychotic drugs: focus on therapeutic and adverse effects.

INTRODUCTION: Schizophrenia is a chronic psychiatric disease, which is treated by antipsychotic drugs. These drugs are mostly D2 and 5-HT2A antagonists and have extrapyramidal side effects depending on the D2 antagonistic effect. Recently admitted antipsychotic drugs also have systemic side effects. Clozapine, which has the strongest antipsychotic effect, can cause neutropenia. A problem in the treatment of schizophrenia is poor patient compliance leading to the recurrence of psychotic symptoms. AREAS COVERED: A search was carried out in Medline using the following terms: antipsychotic drugs, antipsychotic effect, risperidone, olanzapine, clozapine, ziprasidone, aripiprazol, asenapine, questiapine, cariprazine, lurasidone, arrythmia, diabetes mellitus, weight gain, epileptic activity, extrapyramidal symptoms, sexual activity, clinical trials and tolerability. EXPERT OPINION: Most clinical trials describe a good antipsychotic effect of the currently used antipsychotic drugs. The efficacy and safety of the antipsychotic drugs also depend on the form of schizophrenia, for example, the chronic recurrent form of schizophrenia. Clozapine and olanzapine have the safest therapeutic effect, while the side effect of neutropenia must be controlled by 3 weekly blood controls. If schizophrenia has remitted and if patients show a good compliance, the adverse effects can be controlled. The pharmacological treatment should be combined with social therapies and psychoeducation in order to reach a good therapeutic outcome.

Classical neurotransmitters and neuropeptides involved in major depression in a multi-neurotransmitter system: a focus on antidepressant drugs.

We summarize the alterations of classical neurotransmitters and neuropeptides and the corresponding subreceptors involved in major depression. Neuronal circuits in the brainstem, hippocampus and hypothalamus are developed, since they can be used to derive a multimodal pharmacotherapy. In this sense, serotonin hypoactivity could occur through a strong presynaptic inhibition of glutaminergic neurons via the subtype 5 of metabotropic glutaminergic receptors, and noradrenaline hypoactivity could be due to an enhanced presynaptic inhibition of GABAergic neurons via GABAB receptors. In the hippocampus, dopamine hypoactivity leads to a decreased positive effect. In clinical trials, the antidepressant effect of drugs interfering with the mentioned subreceptors, for example the triple reuptake inhibitor amitifadine, is being investigated. Moreover, the alterations of neuropeptides, such as corticotropin-releasing hormone, neuropeptide Y and galanin are pointed out. The additional antidepressant effect of analogs, agonists and antagonists of the mentioned neuropeptides should be examined.

Classical neurotransmitters and neuropeptides involved in major depression: a review.

We propose several pathways that could be involved in major depression. According to our proposal, noradrenaline hypoactivity could occur through a strong presynaptic GABAergic inhibition, via GABA(B) receptors, and serotonin hypoactivity through a strong glutaminergic inhibition via subreceptor 5 of the metabotropic glutaminergic receptor. In this sense, it is important to know whether the antagonists of such receptors might be able to improve the symptoms observed in major depression. Some neuropeptides are also altered in such states (corticotropin-releasing hormone, neuropeptide Y, galanin). It is also important to know whether in addition to current antidepressants the administration of neuropeptides and their agonists/antagonists could ameliorate depressive symptoms.