Distortional effects of separate accounting and formula apportionment on factor allocation

We examine distortions caused by tax base allocation systems-separate accounting (SA) or formula apportionment (FA)-with respect to the allocation of assets and workforce within multinational entities (MNEs). The effects of both systems are intensively debated by EU Member States as they are striving to implement a European tax system. Its introduction would lead to a switch from SA to FA. Moreover, Pillar One of the recent global tax reform includes a mix of both tax base allocation systems. We find that, against the claims of the EU, FA does not necessarily create lower distortions of the factor allocation. Decisive for that assessment is the level of profit shifting under SA. Our results indicate that, in tendency, the factor allocation is more severely distorted by FA when the profit shifting possibilities were rather low under SA. In contrast to former studies, we highlight the importance of analyzing the status quo under the recently applied system (SA) in order to be able to assess the consequences of a switch from SA to FA. Our results are interesting for policy-makers as they help anticipating reactions of MNEs to a change in the applied tax base allocation system and for companies as a basis for future tax planning.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11573-022-01133-5.

COVID-19 and investor behavior

How do retail investors respond to the outbreak of COVID-19? We use transaction-level trading data to show that investors significantly increase their trading activities as the COVID-19 pandemic unfolds, both at the extensive and at the intensive margin. Investors, on average, increase their brokerage deposits and open more new accounts. The average weekly trading intensity increases by 13.9% as the number of COVID-19 cases doubles. The increase in trading is especially pronounced for male and older investors, and affects stock and index trading. Following the 9.99%-drop of the Dow Jones on March 12, investors significantly reduce the usage of leverage.

SAT0152 EFFICACY OF BARICITINIB IN PATIENTS WITH MODERATE-TO-SEVERE RHEUMATOID ARTHRITIS WITH 3 YEARS OF TREATMENT: RESULTS FROM A LONG-TERM STUDY

Background:

Baricitinib (Bari) is an oral, selective and reversible Janus kinase 1 and 2 inhibitor approved for the treatment of adults with active RA. In addition to long-term safety which has been disclosed previously with data up to 7 years [1], an important clinical consideration is whether treatment efficacy can be maintained over the long term.

Objectives:

To evaluate the long-term efficacy of once-daily Bari 4 mg in patients with active rheumatoid arthritis (RA) who were either naïve to or who had inadequate response (IR) to methotrexate (MTX)

Methods:

Post hoc analyses of data from two phase 3 studies, RA-BEGIN (MTX-naïve) and RA-BEAM (MTX-IR) for 52 weeks, and one long-term extension (LTE) study (RA-BEYOND) for an additional 96 weeks were conducted (148 weeks in total). At week 52, MTX-naïve patients initially treated with MTX monotherapy, Bari 4 mg monotherapy, or Bari 4 mg +MTX in RA-BEGIN were switched to open-label Bari 4 mg monotherapy for treatment in the LTE. Similarly, at week 52, MTX-IR patients initially treated with Bari 4 mg [+ background MTX noted as (+MTX) for RA-BEAM] or adalimumab (ADA) (+MTX) in RA-BEAM were switched to open-label Bari 4 mg (+MTX) for treatment in the LTE. Patients who received placebo (+MTX) were switched to open-label Bari 4 mg (+MTX) at week 24. The analyses of efficacy (SDAI) and physical function (HAQ-DI) were conducted on all patients who were randomized into the RA-BEGIN and RA-BEAM studies and had received ≥1 dose of study drug after randomization (mITT population). The proportion of patients who reached low disease activity (LDA), as measured by SDAI ≤11, was evaluated along with change from baseline in HAQ-DI. The non-responder imputation (NRI) method was used for the categorical analysis.

Results:

By week 24 in RA-BEGIN (N=584), 62% of patients treated with Bari 4 mg monotherapy or Bari 4 mg +MTX achieved SDAI LDA in comparison to 40% of pts in the MTX monotherapy group; response rates seen at week 24 in the Bari treatment groups were maintained through week 148 (Fig 1A). Similarly, by week 24 in RA-BEAM (N=1,305), 52% of patients treated with Bari 4 mg (+MTX) and 50% of patients treated with ADA (+MTX) achieved a SDAI LDA in comparison to 26% of patients from the PBO (+MTX) group. The response rate seen at week 24 with Bari 4 mg and ADA were maintained through week 148, even after patients switched from ADA to Bari 4 mg at week 52 (Fig 1B). Similar improvement and maintenance patterns in physical function measured by HAQ-DI were demonstrated. The overall discontinuation rate across treatment groups from RA-BEGIN (19.5%) and RA-BEAM (14.2%) have been published. In the LTE, the discontinuation rate from Bari treatment was 13.7% for patients originating from RA-BEGIN (1.1% due to lack of efficacy, 6.4% due to safety) and 12.6% for patients originating from RA-BEAM (1.8% due to lack of efficacy, 5.9% due to safety).

Figure 1.

Proportion of patients achieving SDAI ≤11 in the NRI analysis†In RA-BEGIN, rescue to Bari 4 mg + MTX was offered at week 24.‡In RA-BEAM, rescue to Bari 4 mg (+ MTX) was offered at week 16. At week 24, all PBO + MTX patients were switched to Bari 4 mg + MTX.§Upon entering RA-BEYOND at week 52, MTX and ADA patients were switched to Bari 4 mg.

Conclusion:

Long-term treatment with Bari 4 mg demonstrated the maintenance of clinically-relevant outcomes for up to 3 years. Low discontinuation rates during the LTE indicated that Bari 4 mg treatment was well-tolerated.

References:

[1]Genovese et al.Annals of the Rheumatic Diseases. 2019;78:308-309.

Disclosure of Interests: :

Josef S. Smolen Grant/research support from: AbbVie, AstraZeneca, Celgene, Celltrion, Chugai, Eli Lilly, Gilead, ILTOO, Janssen, Novartis-Sandoz, Pfizer Inc, Samsung, Sanofi, Consultant of: AbbVie, AstraZeneca, Celgene, Celltrion, Chugai, Eli Lilly, Gilead, ILTOO, Janssen, Novartis-Sandoz, Pfizer Inc, Samsung, Sanofi, Li Xie Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Bochao Jia Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Peter C. Taylor Grant/research support from: Celgene, Eli Lilly and Company, Galapagos, and Gilead, Consultant of: AbbVie, Biogen, Eli Lilly and Company, Fresenius, Galapagos, Gilead, GlaxoSmithKline, Janssen, Nordic Pharma, Pfizer Roche, and UCB, Gerd Rüdiger Burmester Consultant of: AbbVie Inc, Eli Lilly, Gilead, Janssen, Merck, Roche, Pfizer, and UCB Pharma, Speakers bureau: AbbVie Inc, Eli Lilly, Gilead, Janssen, Merck, Roche, Pfizer, and UCB Pharma, Yoshiya Tanaka Grant/research support from: Asahi-kasei, Astellas, Mitsubishi-Tanabe, Chugai, Takeda, Sanofi, Bristol-Myers, UCB, Daiichi-Sankyo, Eisai, Pfizer, and Ono, Consultant of: Abbvie, Astellas, Bristol-Myers Squibb, Eli Lilly, Pfizer, Speakers bureau: Daiichi-Sankyo, Astellas, Chugai, Eli Lilly, Pfizer, AbbVie, YL Biologics, Bristol-Myers, Takeda, Mitsubishi-Tanabe, Novartis, Eisai, Janssen, Sanofi, UCB, and Teijin, Ayesha Elias Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Anabela Cardoso Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Robert Ortmann Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Chad Walls Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Maxime Dougados Grant/research support from: AbbVie, Eli Lilly, Merck, Novartis, Pfizer and UCB Pharma, Consultant of: AbbVie, Eli Lilly, Merck, Novartis, Pfizer and UCB Pharma, Speakers bureau: AbbVie, Eli Lilly, Merck, Novartis, Pfizer and UCB Pharma

FR-900098, an antimalarial development candidate that inhibits the non-mevalonate isoprenoid biosynthesis pathway, shows no evidence of acute toxicity and genotoxicity

FR-900098 is an inhibitor of 1-deoxy-d-xylulose-5-phosphate (DXP) reductoisomerase, the second enzyme in the non-mevalonate isoprenoid biosynthesis pathway. In previous studies, FR-900098 was shown to possess potent antimalarial activity in vitro and in a murine malaria model. In order to provide a basis for further preclinical and clinical development, we studied the acute toxicity and genotoxicity of FR-900098. We observed no acute toxicity in rats, i.e. there were no clinical signs of toxicity and no substance-related deaths after the administration of a single dose of 3000 mg/kg body weight orally or 400 mg/kg body weight intravenously. No mutagenic potential was detected in the Salmonella typhimurium reverse mutation assay (Ames test) or an in vitro mammalian cell gene mutation test using mouse lymphoma L5178Y/TK(+/-) cells (clone 3.7.2C), both with and without metabolic activation. In addition, FR-900098 demonstrated no clastogenic or aneugenic capability or significant adverse effects on blood formation in an in vivo micronucleus test with bone marrow erythrocytes from NMRI mice. We conclude that FR-900098 lacks acute toxicity and genotoxicity, supporting its further development as an antimalarial drug.

Resistance of the Burkholderia cepacia complex to fosmidomycin and fosmidomycin derivatives

The Burkholderia cepacia complex (BCC) is a group of 17 closely related opportunistic pathogens that are able to infect the respiratory tract of cystic fibrosis patients. BCC bacteria are intrinsically resistant to many antibiotics and are therefore difficult to eradicate. Fosmidomycin could be a new therapeutic agent to treat BCC infections as it inhibits 1-deoxy-d-xylulose-5-phosphate reductoisomerase (Dxr), a key enzyme in the non-mevalonate pathway essential in BCC bacteria for isoprenoid synthesis. In this study, the antimicrobial activity of fosmidomycin and eight fosmidomycin derivatives towards 40 BCC strains was investigated. All BCC strains were resistant to fosmidomycin, although addition of glucose-6-phosphate reduced the minimum inhibitory concentration values of FR900098, the fosmidomycin acetyl derivative, from 512 mg/L to 64 mg/L for Burkholderia multivorans and B. cepacia. This enhanced activity was linked to increased expression of the genes involved in glycerol-3-phosphate transport, which appears to be the only route for fosmidomycin import in BCC bacteria. Furthermore, upregulation of a fosmidomycin resistance gene (fsr) encoding an efflux pump was observed during fosmidomycin and FR900098 treatment. These results strongly suggest that the observed resistance in BCC bacteria is due to insufficient uptake accompanied by fosmidomycin and FR900098 efflux.

2-Acylamino-5-chlorobenzophenones with enhanced selectivity towards malaria parasites

Previously we described a series of 5-acylaminobenzophenones with considerable antimalarial activity. Unfortunately, most compounds also displayed high cytotoxicity resulting in low selectivity towards malaria parasites. Through the replacement of the 5-acylamino moiety by simple chlorine and further modifications of the 2-acylamino residue we could obtain inhibitors with improved selectivity towards malaria parasites combined with an acceptable reduction of antimalarial activity.

Double ester prodrugs of FR900098 display enhanced in-vitro antimalarial activity

Fosmidomycin and FR900098 are inhibitors of the 1-deoxy-D-xylulose 5-phosphate reductoisomerase (DXR; IspC), a key enzyme of the mevalonate-independent isoprenoid biosynthesis pathway. We have determined the in-vitro antimalarial activity of two double ester prodrugs 2, 3 in direct comparison with the unmodified FR900098 1 against intraerythrocytic forms of Plasmodium falciparum. Temporarily masking the polar properties of the phosphonate moiety of the DXR inhibitor FR900098 1 enhanced not only its oral bioavailability but also the intrinsic activity of this series against the parasites.

Novel Deoxyxylulosephosphate-Reductoisomerase Inhibitors: Fosmidomycin Derivatives with Spacious Acyl Residues

1-deoxy-D-xylulose-5-phosphate reductoisomerase (Dxr) represents an essential enzyme of the mevalonate-independent pathway of the isoprenoid biosynthesis. Using fosmidomycin as a specific inhibitor of Dxr, this enzyme was previously validated as target for the treatment of malaria and bacterial infections. The replacement of the formyl residue of fosmidomycin by spacious acyl residues yielded inhibitors active in the micromolar range. As predicted by flexible docking, evidence was obtained for the formation of a hydrogen bond between an appropriately placed carbonyl group in the acyl residue and the main-chain NH of Met214 located in the flexible catalytic loop of the enzyme.

Alkoxycarbonyloxyethyl ester prodrugs of FR900098 with improved in vivo antimalarial activity

FR900098 represents a derivative of the new antimalarial drug fosmidomycin with enhanced activity. The mechanism of action is the inhibition of the 1-desoxy-D-xylulose 5-phosphate (DOXP) reductoisomerase, an essential enzyme of the mevalonate independent pathway of isoprenoid biosynthesis. Prodrugs with increased oral activity in mice infected with the rodent malaria parasite Plasmodium vinckei were obtained by masking the phosphonate moiety of FR900098 as alkoxycarbonyloxyethyl esters.

Benzophenone-based farnesyltransferase inhibitors with high activity against Trypanosoma cruzi

Less toxic drugs are needed to combat the human parasite Trypanosoma cruzi (Chagas's disease). One novel target for antitrypanosomal drug design is farnesyltransferase. Several farnesyltransferase inhibitors based on the benzophenone scaffold were assayed in vitro and in vivo with the parasite. The common structural feature of all inhibitors is an amino function which can be protonated. Best in vitro activity (LC50 values 1 and 10 nM, respectively) was recorded for the R-phenylalanine derivative 4a and for the N-propylpiperazinyl derivative 2f. These inhibitors showed no cytotoxicity to cells. When tested in vivo, the survival rates of infected animals receiving the inhibitors at 7 mg/kg body weight/day were 80 and 60% at day 115 postinfection, respectively.

2-(aminoacylamino)benzophenones: farnesyltransferase inhibition and antimalarial activity

The use of amino acids as acyl substitutents at the 2-amino group of our benzophenone core structure yielded compounds with mainly good to moderate farnesyltransferase inhibitory and moderate antimalarial activity. However, these farnesyltransferase inhibitors display some degree of selectivity towards malarial parasites since there was no cytotoxic activity observed at 70-80 microM.

Novel lead structures for antimalarial farnesyltransferase inhibitors

Through the combination of nitrophenylfurylacryloyl moiety which has been designed to occupy an aryl binding site of farnesyltransferase with several AA(X)-peptidomimetic substructures some novel farnesyltransferase inhibitors were obtained. Evaluation of their antimalarial activity and some initial modifications yielded a 4-benzophenone- and a sulfonamid-based novel lead for antimalarial farnesyltransferase inhibitors.

Non-thiol farnesyltransferase inhibitors: N-(4-aminoacylamino-3-benzoylphenyl)-3-[5-(4-nitrophenyl)-2 furyl]acrylic acid amides and their antimalarial activity

Water solubility was previously found to be essential for in vivo-antimalarial activity of a novel type of benzophenone-based farnesyltransferase inhibitors. Introduction of a alpha-amino group into the phenylacetic acid substructure provided more soluble compounds with high farnesyltransferase inhibitory activity. The in vitro-antimalarial activity was detrimentally influenced by this structural modification.

2-(Arylpropionylamino)- and 2-(arylacryloylamino)benzophenones: farnesyltransferase inhibition and antimalarial activity

Structural variation of the 2-acylamino moiety of some benzophenone farnesyltransferase inhibitors led to the para-trifluoromethylphenylpropionyl derivative with relatively low farnesyltransferase inhibition but considerable antimalarial activity and no cytotoxicity.

New antimalarial drugs

Approximately 40% of the world population live in areas with the risk of malaria. Each year, 300-500 million people suffer from acute malaria, and 0.5-2.5 million die from the disease. Although malaria has been widely eradicated in many parts of the world, the global number of cases continues to rise. The most important reason for this alarming situation is the rapid spread of malaria parasites that are resistant to antimalarial drugs, especially chloroquine, which is by far the most frequently used. The development of new antimalarial drugs has been neglected since the 1970s owing to the end colonialism, changes in the areas of military engagement, and the restricted market potential. Only in recent years, in part supported by public funding programs, has interest in the development of antimalarial drugs been renewed. New data available from the recently sequenced genome of the malaria parasite Plasmodium falciparum and the application of methods of modern drug design promise to bring significant development in the fight against this disease.

Structure-activity relationships of novel anti-malarial agents part 8. Effect of different central aryls in biarylacryloylaminobenzophenones on antimalarial activity

Replacement of the 2,5-disubstituted furyl residue present in the known antimalarial agents 8 by other aryl residues resulted in a more or less reduced antimalarial activity in most cases. The only exemption was the 2,4-thienylene compound 11a displaying activity with an IC50 value of 120 nM. In conclusion, the 2,5-furylene compound 8e remains to represent the most active antimalarial agent in this series of farnesyltransferase inhibitors.

Acyloxyalkyl ester prodrugs of FR900098 with improved in vivo anti-malarial activity

FR900098 represents an improved derivative of the new antimalarial drug fosmidomycin and acts through inhibition of the 1-deoxy-D-xylulose 5-phosphate (DOXP) reductoisomerase, an essential enzyme of the mevalonate independent pathway of isoprenoid biosynthesis. Prodrugs with increased activity after oral administration were obtained by chemical modification of the phosphonate moiety to yield acyloxyalkyl esters. The most successful compound demonstrated 2-fold increased activity in mice infected with the rodent malaria parasite Plasmodium vinckei.

Structure-activity relationships of novel anti-malarial agents. Part 6: N-(4-arylpropionylamino-3-benzoylphenyl)-[5-(4-nitrophenyl)-2-furyl]acrylic acid amides

We have demonstrated that the p-trifluoromethylphenylpropionylamino residue at the 2-position of the core structure leads to an active benzophenone-type anti-malarial agent. The attempt to improve water solubility by introduction of an amino group into the alpha-position of the arylpropionyl residue resulted in decreased activity.

Structure-activity relationships of novel anti-malarial agents: part 5. N-(4-acylamino-3-benzoylphenyl)-[5-(4-nitrophenyl)-2-furyl]acrylic acid amides

We have developed the [5-(4-nitrophenyl)-2-furyl]acrylic acid substituted benzophenone 4g as a novel lead for anti-malarial agents. Here, we demonstrated that the acyl residue at the 2-amino group of the benzophenone core structure has to be a phenylacetic acid substructure substituted in its para-position with methyl or other substituents of similar size. The trifluoromethyl substituted derivative displayed an IC(50) of 47 nM against the multi-drug resistant Plasmodium falciparum strain Dd2.

A heritable defect in IL-12 signaling in B10.Q/J mice. II. Effect on acute resistance to Toxoplasma gondii and rescue by IL-18 treatment

This study documents a defect in IL-12-dependent IFN-gamma responses in a substrain (B10.Q-H2-(q)/SgJ) of B10.Q mice that manifests as an acute susceptibility to infection by the intracellular protozoan pathogen, Toxoplasma gondii. Despite robust systemic production of IL-12, infected B10.Q/J animals fail to mount an early IFN-gamma response after parasite inoculation. Genetic experiments revealed that the host resistance and IFN-gamma production defects are determined by a single autosomal recessive locus distinct from the Stat4 gene. Nonetheless, a delayed IL-12-mediated IFN-gamma response emerges in later stages of acute infection but is unable to prevent host mortality. IL-18 administration restores, in an IL-12-dependent manner, the early IFN-gamma response and host resistance of B10.Q/J animals. These in vivo studies indicate that the partially impaired IL-12 responsiveness in B10.Q/J mice can result in defective host resistance and demonstrate a therapeutic function for IL-18 in reversing a genetically based immunodeficiency in IL-12-dependent IFN-gamma production.

A heritable defect in IL-12 signaling in B10.Q/J mice. I. In vitro analysis

B10.Q mice are normally susceptible to the induction of collagen-induced arthritis. We noted that one subline of B10.Q mice, B10.Q/J, was completely resistant to disease induction when immunized with collagen in CFA. B10.Q/J mice have a global defect in the generation of Th1 responses, and Ag-specific T cells derived from this strain failed to produce IFN-gamma. Because T cells from these mice could produce normal amounts of IFN-gamma when activated by IL-12/IL-18-independent stimuli, the defect appeared to be a failure to respond to IL-12. This defect extended to NK cells, which also failed to produce IFN-gamma when stimulated by IL-12. The capacity of NK cells, but not activated T cells, to produce IFN-gamma in response to IL-12 could be partially restored by IL-18. The expression of the IL-12R beta1- and beta2-chains on T cells and NK cells from B10.Q/J mice was normal. However, activated T cells from B10.Q/J mice did not signal normally through the IL-12R and manifested a defect in their capacity to phosphorylate Stat4. This defect was partial in that it could be overcome by increasing both the concentration of IL-12 and the incubation times in the Stat4 phosphorylation assays. Because Stat4 function is apparently intact in B10.Q/J mice, the defect in IL-12 signaling can be localized between the IL-12R complex and Stat4. This subtle abnormality in IL-12 responsiveness results in a profound defect in the generation of Th1 cells and the development of autoimmune disease.

Position-independent expression of a human nerve growth factor-luciferase reporter gene cloned on a yeast artificial chromosome vector

Two yeast artificial chromosomes containing the entire human nerve growth factor gene were isolated and mapped. By homologous recombination a luciferase gene was precisely engineered into the coding portion of the NGF gene and a neomycin selection marker was placed adjacent to one of the YAC telomeres. Expression of the YAC-based NGF reporter gene and a plasmid-based NGF reporter gene were compared with the regulation of endogenous mouse NGF protein in mouse L929 fibroblasts. In contrast to the plasmid-based reporter gene, expression and regulation of the YAC-based reporter gene was independent of the site of integration of the transgene. Basic fibroblast growth factor and okadaic acid stimulated expression of the YAC transgene, whereas transforming growth factor-beta and dexamethasone inhibited it. Although cyclic AMP strongly stimulated production of the endogenous mouse NGF, no effect was seen on the human NGF reporter genes. Downregulation of the secretion of endogenous mouse NGF already occurred at an EC50 of 1-2 nM dexamethasone, but downregulation of the expression of NGF reporter genes occurred only at EC50 of 10 nM. This higher concentration was also required for upregulation of luciferase genes driven by the dexamethasone-inducible promoter of the mouse mammary tumor virus in L929 fibroblasts.

Is there a long-lasting effect of a short-term nerve growth factor application on axotomized rat septohippocampal neurons?

Loss of choline acetyltransferase (ChAT)-immunoreactive neurons in the medial septum (MS) following fimbria transection can be prevented by nerve growth factor (NGF) application. Here we have studied the long-term effects of a short-term NGF treatment starting immediately after lesion and lasting for the first 3 weeks. We demonstrate that this NGF treatment rescues many ChAT neurons after short survival time (3 weeks) but does not have a long-lasting (6 months) effect on both ChAT- and parvalbumin-immunopositive (GABAergic) MS neurons.

Astrocyte-derived TGF-beta 2 and NGF differentially regulate neural recognition molecule expression by cultured astrocytes

Because of the importance of neural recognition molecules expressed by glial cells to mediate interactions with neurons, growth factors and cytokines known to be functional during morphogenesis and in diseases of the nervous system were studied for their effects on recognition molecule expression by cultured immature and mature astrocytes from several brain regions. In cultures of immature astrocytes, transforming growth factors-beta 1 (TGF-beta 1) and -beta 2 (TGF-beta 2) and nerve growth factor (NGF) increased expression of the neural adhesion molecule L1, leading to a glia-mediated L1-specific increase in neurite outgrowth of dorsal root ganglion neurons on the astrocyte substrate. L1 expression induced by TGF-beta was inhibited by addition of antibodies to NGF, suggesting that TGF-beta influences L1 expression by modulating production of NGF by astrocytes. TGF-beta 1 and -beta 2 decreased expression of N-CAM by immature astrocytes. Since N-CAM expression was not affected by NGF and antibodies to NGF did not abolish the TGF-beta-induced decrease in N-CAM expression, NGF did not appear to be the mediator for regulating expression of N-CAM. Expression of the adhesion molecule on glia (AMOG) was not affected by any factor. NGF and TGF-beta 2 in latent form, but not TGF-beta 1 were found in the culture supernatants. Addition of interferon-gamma (IFN-gamma), interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6), platelet-derived growth factor (PDGF), or basic fibroblast growth factor (bFGF) to the cultures did not change recognition molecule expression. REcognition molecule expression by mature astrocytes was not found to be modified by any of the factors tested. In view of the observation that levels of L1 and N-CAM expression correlated with the presence of TGF-beta 2 and NGF in the culture supernatants of immature astrocytes, an autocrine regulatory mechanism for recognition molecule expression by these cells is suggested to play a crucial role in regulation of neuron-glia interactions.

Induction of glia-derived nexin after lesion of a peripheral nerve

Glia-derived nexin (GDN), also known as protease nexin I, is a serine protease inhibitor of deduced relative molecular mass 41,700, identified in conditioned media of glioma cells by its neurite-promoting activity. GDN can promote neurite outgrowth in vitro from neuroblastoma cells, sympathetic neurons and hippocampal neurons (L. Farmer et al., manuscript in preparation). In vivo, GDN is constitutively expressed in all parts of the olfactory system, where axonal regeneration and neurogenesis occur continuously throughout life. This observation indicates that GDN could be important for axonal regeneration in vivo. To investigate this possibility, we have taken advantage of the fact that damage to nerves in the peripheral nervous system leads to their regeneration, whereas in the central nervous system no such regeneration can occur. Here we report that after lesion of the rat sciatic nerve there is a large transient increase in the amount of GDN messenger RNA and of released GDN. The cells showing GDN immunoreactivity are mainly localized distal to the lesion site. These results further support the suggestion that GDN is important for axonal regeneration in vivo, and indicate that protease inhibitors could have a role in Wallerian degeneration and peripheral nerve regeneration.

[The sensory cells of the fetal vomeronasal organ in the human. A contribution to the variability of their differentiation and rudimentary development]

Serial cranial sections of seven human fetuses between 11 and 18 weeks were studied using Palmgren's silver impregnation technique. The vomeronasal organ revealed receptor cells in four cases. This is the first demonstration of functional elements in the vomeronasal organ in man. They may also be present in old-world monkeys. It is evident that the human vomeronasal organ is frequently present in man, but differentiation of the organ and its individual constituents shows considerable variation.

Cholinomimetics induce theta rhythm and reduce hippocampal pyramidal cell excitability

The actions of cholinomimetics and of physostigmine were tested on two parameters reflecting hippocampal activity, namely theta activity and pyramidal cell excitability. In rats pretreated with methylscopolamine and anaesthetized with urethane i.v. administration of the cholinomimetics oxotremorine and arecoline and the cholinesterase blocker physostigmine evoked theta wave activity in the hippocampus, which was blocked by scopolamine. Spectral analysis demonstrated that the frequency of the theta waves induced was dose-related, ranging from about 3 Hz to between 5 and 6 Hz. theta Activity could not be induced by arecoline in animals with large septal lesions. Pyramidal cell excitability is known to be increased by endogenous acetylcholine released from cholinergic fibres. In the present study, however, i.v. injections of oxotremorine, arecoline and physostigmine in doses that induce theta activity diminished the excitability of CA1 pyramidal cells in a dose-dependent manner, as judged by the reduction in the amplitude of the population spike and the dendritic epsp. These depressant effects were attenuated by scopolamine but not by methylscopolamine. The depressant effect of arecoline was attenuated in rats with extensive lesions in the medial septal area. The present findings demonstrate that exogenously administered cholinomimetics only partly mimic the action of endogenous acetylcholine in the hippocampus. The central sites of action of exogenously administered cholinomimetics for mediation of theta activity and alteration of pyramidal cell excitability remain to be elucidated.

Behavioral effects and general pharmacology of 4-(5-chloro-benzofuranyl-2)-1-methylpiperidine HC1, an antidepressant inhibiting both monoamine oxidase A and 5-hydroxytryptamine uptake

In psychopharmacological tests in rats and mice, 4-(5-chloro-benzofuranyl-2)-1-methylpiperidine HC1 (CGP 4718 A) was found to exert behavioral effects typical of both monoamine oxidase (MAO)-A and 5-hydroxytryptamine (5-HT) uptake inhibitors (reserpine antagonism, L-5-HTP potentiation, antiaggressive activity in isolated mice). The potential antidepressant activity of the drug was indicated in rats by antagonism of reserpine and its effect in the social-conflict test. CGP 4718 A did not impair motor coordination and had no influence on locomotor activity up to high doses in mice and rats. In monkeys, it increased directed individual activities, including sex-related behaviors and diminished locomotor activity and passivity. Electroencephalographic studies in cats revealed a significant decrease in paradoxical sleep after treatment with CGP 4718 A. In isolated organs, no significant antagonism of norepinephrine, 5-HT, acetylcholine or histamine was found. Cardiovascular studies in cats showed only transient effects on blood pressure and no effect on heart rate. In conscious dogs no cardiovascular effects were found. No potentiation of the pressor effect of tyramine in rats was detectable after repeated doses of up to 300 mg/kg p.o. A weak cardiodepressant effect was seen in isolated guinea pig atria. In conclusion, in animal experiments CGP 4718 A combines an interesting spectrum of antidepressant, activating and antiaggressive properties with a lack of cardiovascular and tyramine-potentiating effects.