Identification of myeloid-derived growth factor as a mechanically-induced, growth-promoting angiocrine signal for human hepatocytes

Recently, we have shown that after partial hepatectomy (PHx), an increased hepatic blood flow initiates liver growth in mice by vasodilation and mechanically-triggered release of angiocrine signals. Here, we use mass spectrometry to identify a mechanically-induced angiocrine signal in human hepatic endothelial cells, that is, myeloid-derived growth factor (MYDGF). We show that it induces proliferation and promotes survival of primary human hepatocytes derived from different donors in two-dimensional cell culture, via activation of mitogen-activated protein kinase (MAPK) and signal transducer and activator of transcription 3 (STAT3). MYDGF also enhances proliferation of human hepatocytes in three-dimensional organoids. In vivo, genetic deletion of MYDGF decreases hepatocyte proliferation in the regenerating mouse liver after PHx; conversely, adeno-associated viral delivery of MYDGF increases hepatocyte proliferation and MAPK signaling after PHx. We conclude that MYDGF represents a mechanically-induced angiocrine signal and that it triggers growth of, and provides protection to, primary mouse and human hepatocytes.

Bispecific soluble cytokine receptor-nanobody fusions inhibit Interleukin (IL-)6 trans-signaling and IL-12/23 or tumor necrosis factor (TNF) signaling

At least 0.5% of people in the Western world develop inflammatory bowel disease (IBD). While antibodies that block tumor necrosis factor (TNF) α and Interleukin (IL-)23 have been approved for the treatment of IBD, IL-6 antibodies failed in the phase II clinical trial due to non-tolerable side effects. However, two clinical phase II studies suggest that inhibiting IL-6/soluble IL-6R (sIL-6R)-induced trans-signaling via the cytokine receptor gp130 benefit IBD patients with fewer adverse events. Here we develop inhibitors targeting a combination of IL-6/sIL-6R and TNF or IL-12/IL-23 signaling, named cs130-TNFVHHFc and cs130-IL-12/23VHHFc. Surface plasmon resonance experiments showed that recombinant cs130-TNFVHHFc and cs130-IL-12/23VHHFc bind with high affinity to IL-6/sIL-6R complexes and human TNFα (hTNFα) or IL-12/IL-23, respectively. Immunoprecipitation experiments have verified the higher ordered complex formation of the inhibitors with IL-6/sIL-6R and IL-12. We demonstrated that cs130-TNFVHHFc and cs130-IL-12/23VHHFc block IL-6/sIL-6R trans-signaling-induced proliferation and STAT3 phosphorylation of Ba/F3-gp130 cells, as well as hTNFα- or IL-23-induced signaling, respectively. In conclusion, cs130-TNFVHHFc and cs130-IL-12/23VHHFc represent a class of dimeric and bispecific chimeric cytokine inhibitors that consist of a soluble cytokine receptor fused to anti-cytokine nanobodies.

Respiratory syncytial virus-approved mAb Palivizumab as ligand for anti-idiotype nanobody-based synthetic cytokine receptors

Synthetic cytokine receptors can modulate cellular functions based on an artificial ligand to avoid off-target and/or unspecific effects. However, ligands that can modulate receptor activity so far have not been used clinically because of unknown toxicity and immunity against the ligands. Here, we developed a fully synthetic cytokine/cytokine receptor pair based on the antigen-binding domain of the respiratory syncytial virus-approved mAb Palivizumab as a synthetic cytokine and a set of anti-idiotype nanobodies (AIPVHH) as synthetic receptors. Importantly, Palivizumab is neither cross-reactive with human proteins nor immunogenic. For the synthetic receptors, AIPVHH were fused to the activating interleukin-6 cytokine receptor gp130 and the apoptosis-inducing receptor Fas. We found that the synthetic cytokine receptor AIPVHHgp130 was efficiently activated by dimeric Palivizumab single-chain variable fragments. In summary, we created an in vitro nonimmunogenic full-synthetic cytokine/cytokine receptor pair as a proof of concept for future in vivo therapeutic strategies utilizing nonphysiological targets during immunotherapy.

Cytokimera GIL-11 rescued IL-6R deficient mice from partial hepatectomy-induced death by signaling via non-natural gp130:LIFR:IL-11R complexes

All except one cytokine of the Interleukin (IL-)6 family share glycoprotein (gp) 130 as the common β receptor chain. Whereas Interleukin (IL-)11 signal via the non-signaling IL-11 receptor (IL-11R) and gp130 homodimers, leukemia inhibitory factor (LIF) recruits gp130:LIF receptor (LIFR) heterodimers. Using IL-11 as a framework, we exchange the gp130-binding site III of IL-11 with the LIFR binding site III of LIF. The resulting synthetic cytokimera GIL-11 efficiently recruits the non-natural receptor signaling complex consisting of gp130, IL-11R and LIFR resulting in signal transduction and proliferation of factor-depending Ba/F3 cells. Besides LIF and IL-11, GIL-11 does not activate receptor complexes consisting of gp130:LIFR or gp130:IL-11R, respectively. Human GIL-11 shows cross-reactivity to mouse and rescued IL-6R^-/- mice following partial hepatectomy, demonstrating gp130:IL-11R:LIFR signaling efficiently induced liver regeneration. With the development of the cytokimera GIL-11, we devise the functional assembly of the non-natural cytokine receptor complex of gp130:IL-11R:LIFR.

Constitutive Activation of gp130 in T Cells Results in Senescence and Premature Aging

IL-6 family members contribute to host defense through the stimulation of acute-phase signaling, hematopoiesis, immune reactions, and regenerative processes. To investigate essential mechanisms that are linked toward a constitutively activated gp130 signaling, we generated and characterized a mouse model that reflects a constitutive and cytokine-independent activation of JAK/STAT3 signaling by Lgp130 in CD4- and CD8-positive T cells. Lgp130 is an engineered form of gp130 in which dimerization and activation are forced by a leucine zipper. T cell-specific Lgp130 activation resulted in massive phenotypical abnormalities, including splenomegaly, lymphadenopathy, and an upregulation of innate immune system components shown by hyperinflammatory signatures in several organs. Moreover, T cell-restricted expression of Lgp130 resulted in increased numbers of cytotoxic and regulatory T cells, especially in lymph nodes. Consistent with this, we found an elevated platelet production and increase in megakaryocytes in the spleen and bone marrow that are causative for an acute thrombocytosis accompanied by anemia. Due to a shortened life span of T cell-specific Lgp130 mice, we could also show that next to an overall increase in regulatory cell-cycle genes, an activation of p53 and increased expression of p21 provide evidence for a senescence-like phenotype. Together, these data suggest that T cell-restricted gp130 activation is not only involved in autoimmune processes but also in senescence-associated aging. Therefore, Lgp130 expression in T cells might be a suitable model to study inflammation and disease.

Interleukin 6 receptor is not directly involved in regulation of body weight in diet-induced obesity with and without physical exercise

High level of interleukin 6 (IL-6), released by adipocytes in an obesity-induced, low grade inflammation state, is a regulator of insulin resistance and glucose tolerance. IL-6 has also regenerative, anti-inflammatory and anti-diabetogenic functions, when secreted as myokine by skeletal muscles during physical exercise. IL-6 mainly activates cells via two different receptor constellations: classic and trans-signalling, in which IL-6 initially binds to membrane-bound receptor (IL-6R) or soluble IL-6 receptor (sIL-6R) before activating signal transducing gp130 receptor. Previously, we generated transgenic soluble IL-6 receptor ^+/+ (sIL-6R^+/+) mice with a strategy that mimics ADAM10/17 hyperactivation, reflecting a situation in which only IL-6 trans-signalling is active, whereas classic signalling is completely abrogated. In this study, we metabolically phenotyped IL-6R deficient mice (IL-6R-KO), sIL-6R^+/+ mice and wild-type littermates fed either a standard chow (SD) or a high-fat diet (HFD) in combination with a 6-weeks treadmill exercise protocol. All mice were subjected to analyses of body weight and body composition, determination of blood glucose and insulin level under fasting conditions, as well as determination of substrate preference by indirect calorimetry. Neither classic IL-6 nor trans-signalling do influence the outcome of diet-induced obesity, insulin sensitivity and glycaemic control. Furthermore, IL-6R deficiency is not impairing the beneficial effect of physical exercise. We conclude that the IL-6R does not play a requisite role in regulation of body weight and glucose metabolism in diet-induced obese mice.

Efficiently Restored Thrombopoietin Production by Ashwell-Morell Receptor and IL-6R Induced Janus Kinase 2/Signal Transducer and Activator of Transcription Signaling Early After Partial Hepatectomy

BACKGROUND AND AIMS

Thrombocytopenia has been described in most patients with acute and chronic liver failure. Decreased platelet production and decreased half-life of platelets might be a consequence of low levels of thrombopoietin (TPO) in these patients. Platelet production is tightly regulated to avoid bleeding complications after vessel injury and can be enhanced under elevated platelet destruction as observed in liver disease. Thrombopoietin (TPO) is the primary regulator of platelet biogenesis and supports proliferation and differentiation of megakaryocytes.

APPROACH AND RESULTS

Recent work provided evidence for the control of TPO mRNA expression in liver and bone marrow (BM) by scanning circulating platelets. The Ashwell-Morell receptor (AMR) was identified to bind desialylated platelets to regulate hepatic thrombopoietin (TPO) production by Janus kinase (JAK2)/signal transducer and activator of transcription (STAT3) activation. Two-thirds partial hepatectomy (PHx) was performed in mice. Platelet activation and clearance by AMR/JAK2/STAT3 signaling and TPO production were analyzed at different time points after PHx. Here, we demonstrate that PHx in mice led to thrombocytopenia and platelet activation defects leading to bleeding complications, but unaltered arterial thrombosis, in these mice. Platelet counts were rapidly restored by up-regulation and crosstalk of the AMR and the IL-6 receptor (IL-6R) to induce JAK2-STAT3-TPO activation in the liver, accompanied by an increased number of megakaryocytes in spleen and BM before liver was completely regenerated.

CONCLUSIONS

The AMR/IL-6R-STAT3-TPO signaling pathway is an acute-phase response to liver injury to reconstitute hemostasis. Bleeding complications were attributable to thrombocytopenia and platelet defects induced by elevated PGI₂ , NO, and bile acid plasma levels early after PHx that might also be causative for the high mortality in patients with liver disease.

Lactate and IL6 define separable paths of inflammatory metabolic adaptation

Lactate is an end point of Warburg-type metabolism found in inflammatory macrophages. Recently, lactate was shown to modify histones of lipopolysaccharide (LPS)-activated macrophages in a time-dependent way and promote the expression of genes linked to tissue repair, including arginase-1 (Arg1). We tested the interrelationships between histone lactylation (Kla) and tissue reparative gene expression and found that Kla was uncoupled from changes in gene expression linked to resolving M2 macrophage activation but correlated with Arg1 expression. LPS-induced Arg1 was instead dependent on autocrine-paracrine interleukin-6 (IL6) production, the IL6 receptor, and Stat3 signal transduction. We found that Kla increases as macrophages prepare to die under inflammatory stress, and Kla was absent in macrophages that cannot generate reactive nitrogen or have defects in diverse macrophage death pathways. Thus, Kla is a consequence rather than a cause of macrophage activation but occurs coincidently with an IL6- and Arg1-dependent metabolic rewiring under inflammatory duress.

Responsiveness of observer rating scales by analysis of number of days until improvement in patients with major depression

Several well-known observer scales, including the Hamilton Depression Scale (HAM-D), Montgomery-Åsberg Scale (MADRS), Major Depression Rating Scale (MDS), Melancholia Scale (MES), and Inventory for Depressive Symptomatology (IDS) used for measuring severity of depressive states have been compared by their responsiveness in an open trial including patients treated with a combination of citalopram and mianserin. The patients fulfilled the Diagnostic and Statistical Manual (DSM)-IV criteria for major depressive episode, and all scored 18 or more on the HAM-D before treatment. Onset of antidepressant action was defined as an improvement of rating scale scores of 25% or more of pre-treatment scores. A response to treatment was defined as a reduction of 50% or more on the pre-treatment scores. The results showed that the number of treatment days until improvement was 11 to 13 with no difference between the scales. The days until response were between 18 and 21 with no difference between the scales. In conclusion, the depression scales were found to be equal in their ability to detect changes in depressive symptoms during treatment. The mean of days to response was 19 for the combination of citalopram and mianserin. This is similar to the response for the combination of fluoxetine and pinolol.

Fragile X mental retardation protein protects against tumour necrosis factor-mediated cell death and liver injury

OBJECTIVE

The Fragile X mental retardation (FMR) syndrome is a frequently inherited intellectual disability caused by decreased or absent expression of the FMR protein (FMRP). Lack of FMRP is associated with neuronal degradation and cognitive dysfunction but its role outside the central nervous system is insufficiently studied. Here, we identify a role of FMRP in liver disease.

DESIGN

Mice lacking Fmr1 gene expression were used to study the role of FMRP during tumour necrosis factor (TNF)-induced liver damage in disease model systems. Liver damage and mechanistic studies were performed using real-time PCR, Western Blot, staining of tissue sections and clinical chemistry.

RESULTS

Fmr1^null mice exhibited increased liver damage during virus-mediated hepatitis following infection with the lymphocytic choriomeningitis virus. Exposure to TNF resulted in severe liver damage due to increased hepatocyte cell death. Consistently, we found increased caspase-8 and caspase-3 activation following TNF stimulation. Furthermore, we demonstrate FMRP to be critically important for regulating key molecules in TNF receptor 1 (TNFR1)-dependent apoptosis and necroptosis including CYLD, c-FLIP_S and JNK, which contribute to prolonged RIPK1 expression. Accordingly, the RIPK1 inhibitor Necrostatin-1s could reduce liver cell death and alleviate liver damage in Fmr1^null mice following TNF exposure. Consistently, FMRP-deficient mice developed increased pathology during acute cholestasis following bile duct ligation, which coincided with increased hepatic expression of RIPK1, RIPK3 and phosphorylation of MLKL.

CONCLUSIONS

We show that FMRP plays a central role in the inhibition of TNF-mediated cell death during infection and liver disease.

IL-6 Trans-signaling Controls Liver Regeneration After Partial Hepatectomy

Interleukin-6 (IL-6) is critically involved in liver regeneration after partial hepatectomy (PHX). Previous reports suggest that IL-6 trans-signaling through the soluble IL-6/IL-6R complex is involved in this process. However, the long-term contribution of IL-6 trans-signaling for liver regeneration after PHX is unknown. PHX-induced generation of the soluble IL-6R by ADAM (a disintegrin and metallo) proteases enables IL-6 trans-signaling, in which IL-6 forms an agonistic complex with the soluble IL-6 receptor (sIL-6R) to activate all cells expressing the signal-transducing receptor chain glycoprotein 130 (gp130). In contrast, without activation of ADAM proteases, IL-6 in complex with membrane-bound IL-6R and gp130 activates classic signaling. Here, we describe the generation of IL-6 trans-signaling mice, which exhibit boosted IL-6 trans-signaling and abrogated classic signaling by genetic conversion of all membrane-bound IL-6R into sIL-6R proteins phenocopying hyperactivation of ADAM-mediated shedding of IL-6R as single substrate. Importantly, although IL-6R deficient mice were strongly affected by PHX, survival and regeneration of IL-6 trans-signaling mice was indistinguishable from control mice, demonstrating that IL-6 trans-signaling fully compensates for disabled classic signaling in liver regeneration after PHX. Moreover, we monitored the long-term consequences of global IL-6 signaling inhibition versus IL-6 trans-signaling selective blockade after PHX by IL-6 monoclonal antibodies and soluble glycoprotein 130 as fragment crystallizable fusion, respectively. Both global IL-6 blockade and selective inhibition of IL-6 trans-signaling results in a strong decrease of overall survival after PHX, accompanied by decreased signal transducer and activator of transcription 3 phosphorylation and proliferation of hepatocytes. Mechanistically, IL-6 trans-signaling induces hepatocyte growth factor production by hepatic stellate cells. Conclusion: IL-6 trans-signaling, but not classic signaling, controls liver regeneration following PHX.

iRhom2 inhibits bile duct obstruction-induced liver fibrosis

Chronic liver disease can induce prolonged activation of hepatic stellate cells, which may result in liver fibrosis. Inactive rhomboid protein 2 (iRhom2) is required for the maturation of A disintegrin and metalloprotease 17 (ADAM17, also called TACE), which is responsible for the cleavage of membrane-bound tumor necrosis factor-α (TNF-α) and its receptors (TNFRs). Here, using the murine bile duct ligation (BDL) model, we showed that the abundance of iRhom2 and activation of ADAM17 increased during liver fibrosis. Consistent with this, concentrations of ADAM17 substrates were increased in plasma samples from mice after BDL and in patients suffering from liver cirrhosis. We observed increased liver fibrosis, accelerated disease progression, and an increase in activated stellate cells after BDL in mice lacking iRhom2 (Rhbdf2^-/- ) compared to that in controls. In vitro primary mouse hepatic stellate cells exhibited iRhom2-dependent shedding of the ADAM17 substrates TNFR1 and TNFR2. In vivo TNFR shedding after BDL also depended on iRhom2. Treatment of Rhbdf2^-/- mice with the TNF-α inhibitor etanercept reduced the presence of activated stellate cells and alleviated liver fibrosis after BDL. Together, these data suggest that iRhom2-mediated inhibition of TNFR signaling protects against liver fibrosis.

B Cell-Mediated Maintenance of Cluster of Differentiation 169-Positive Cells Is Critical for Liver Regeneration

The liver has an extraordinary capacity to regenerate through activation of key molecular pathways. However, central regulators controlling liver regeneration remain insufficiently studied. Here, we show that B cell-deficient animals failed to induce sufficient liver regeneration after partial hepatectomy (PHx). Consistently, adoptive transfer of B cells could rescue defective liver regeneration. B cell-mediated lymphotoxin beta production promoted recovery from PHx. Absence of B cells coincided with loss of splenic cluster of differentiation 169-positive (CD169⁺ ) macrophages. Moreover, depletion of CD169⁺ cells resulted in defective liver regeneration and decreased survival, which was associated with reduced hepatocyte proliferation. Mechanistically, CD169⁺ cells contributed to liver regeneration by inducing hepatic interleukin-6 (IL-6) production and signal transducer and activator of transcription 3 activation. Accordingly, treatment of CD169⁺ cell-depleted animals with IL-6/IL-6 receptor rescued liver regeneration and severe pathology following PHx. Conclusion: We identified CD169⁺ cells to be a central trigger for liver regeneration, by inducing key signaling pathways important for liver regeneration.

Storage of Erythrocytes Induces Suicidal Erythrocyte Death

BACKGROUND/AIMS

Similar to apoptosis of nucleated cells, red blood cells (RBC) can undergo suicidal cell death - called eryptosis. It is characterized by cell shrinkage and phosphatidylserine translocation. Eryptosis is triggered by an increase of intracellular calcium concentration due to activation of nonselective cation channels. The cation channels and consequently eryptosis are inhibited by erythropoietin. Eryptotic RBC are engulfed by macrophages and thus rapidly cleared from circulating blood. In this study, we explored whether storage of RBC influences the rate of eryptosis.

METHODS

Flow cytometry was employed to quantify phosphatidylserine exposing erythrocytes from annexin V binding and cytosolic Ca2+ activity from Fluo-3 fluorescence. Clearance of stored murine RBC was tested by injection of carboxyfluorescein succinimidyl ester (CFSE)-labelled erythrocytes.

RESULTS

Storage for 42 days significantly increased the percentage of phosphatidylserine exposing and haemolytic erythrocytes, an effect blunted by removal of extracellular calcium. Phosphatidylserine exposure could be inhibited by addition of erythropoietin. Upon transfusion, the clearance of murine CFSE-labelled RBC from circulating blood was significantly higher following storage for 10 days when compared to 2 days of storage.

CONCLUSION

Storage of RBC triggers eryptosis by Ca2+ and erythropoietin sensitive mechanisms.

Cooperative role of lymphotoxin β receptor and tumor necrosis factor receptor p55 in murine liver regeneration

BACKGROUND & AIMS

The liver exhibits a unique capacity for regeneration in response to injury. Lymphotoxin-β receptor (LTβR), a core member of the tumor necrosis factor (TNF)/tumor necrosis factor receptor (TNFR) superfamily is known to play an important role in this process. However, the function of LTβR during pathophysiological alterations and its molecular mechanisms during liver regeneration are so far ill-characterized.

METHODS

LTβR(-/-) mice were subjected to 70% hepatectomy and liver regeneration capacity, bile acid profiles, and transcriptome analysis were performed.

RESULTS

LTβR(-/-) deficient mice suffered from increased and prolonged liver tissue damage after 70% hepatectomy, accompanied by deregulated bile acid homeostasis. Pronounced differences in the expression patterns of genes relevant for bile acid synthesis and recirculation were observed. LTβR and TNFRp55 share downstream signalling elements. Therefore, LTβR(-/-) mice were treated with etanercept to create mice functionally deficient in both signalling pathways. Strikingly, the combined blockade of TNFRp55 and LTβR signalling leads to complete failure of liver regeneration resulting in death within 24 to 48h after PHx. Transcriptome analysis revealed a marked disparity in gene expression programs in livers of LTβR(-/-) and etanercept-treated LTβR(-/-) vs. wild-type animals after PHx. Murinoglobulin 2 was identified as a significantly differentially regulated gene.

CONCLUSIONS

LTβR is essential for efficient liver regeneration and cooperates with TNFRp55 in this process. Differences in survival kinetics strongly suggest distinct functions for these two cytokine receptors in liver regeneration. Failure of TNFR and LTβR signalling renders liver regeneration impossible.

Isoprene function in two contrasting poplars under salt and sunflecks

In the present study, biogenic volatile organic compound (BVOC) emissions and photosynthetic gas exchange of salt-sensitive (Populus x canescens (Aiton) Sm.) and salt-tolerant (Populus euphratica Oliv.) isoprene-emitting and non-isoprene-emitting poplars were examined under controlled high-salinity and high-temperature and -light episode ('sunfleck') treatments. Combined treatment with salt and sunflecks led to an increased isoprene emission capacity in both poplar species, although the photosynthetic performance of P. × canescens was reduced. Indeed, different allocations of isoprene precursors between the cytosol and the chloroplast in the two species were uncovered by means of (13)CO2 labeling. Populus × canescens leaves, moreover, increased their use of 'alternative' carbon (C) sources in comparison with recently fixed C for isoprene biosynthesis under salinity. Our studies show, however, that isoprene itself does not have a function in poplar survival under salt stress: the non-isoprene-emitting leaves showed only a slightly decreased photosynthetic performance compared with wild type under salt treatment. Lipid composition analysis revealed differences in the double bond index between the isoprene-emitting and non-isoprene-emitting poplars. Four clear metabolomics patterns were recognized, reflecting systemic changes in flavonoids, sterols and C fixation metabolites due to the lack/presence of isoprene and the absence/presence of salt stress. The studies were complemented by long-term temperature stress experiments, which revealed the thermotolerance role of isoprene as the non-isoprene-emitting leaves collapsed under high temperature, releasing a burst of BVOCs. Engineered plants with a low isoprene emission potential might therefore not be capable of resisting high-temperature episodes.

Cutting edge: Inhibition of IL-6 trans-signaling protects from malaria-induced lethality in mice

Circulating IL-6 levels correlate with the severity of blood-stage malaria in humans and mouse models, but the impact of IL-6 classic signaling through membrane IL-6Rα, as well as IL-6 trans-signaling through soluble IL-6Rα, on the outcome of malaria has remained unknown. In this study, we created IL-6Rα-deficient mice that exhibit a 50% survival of otherwise lethal blood-stage malaria of the genus Plasmodium chabaudi. Inducing IL-6 trans-signaling by injection of mouse recombinant soluble IL-6Rα in IL-6Rα-deficient mice restores the lethal outcome to malaria infection. In contrast, inhibition of IL-6 trans-signaling via injection of recombinant sGP130Fc protein in control mice results in a 40% survival rate. Our data demonstrate that IL-6 trans-signaling, rather than classic IL-6 signaling, contributes to malaria-induced lethality in mice, preceded by an increased inflammatory response. Therefore, inhibition of IL-6 trans-signaling may serve as a novel promising therapeutic basis to combat malaria.

Poplar volatiles - biosynthesis, regulation and (eco)physiology of isoprene and stress-induced isoprenoids

Plants interact with their environment through a wide variety of biogenic volatile organic compounds (BVOCs), with isoprenoids ( identical with terpenes), i.e. isoprene, mono- and sesquiterpenes, playing an important role. Isoprene, a hemiterpene, is the simplest isoprenoid compound mainly emitted by tree species like poplars, oaks and willows. Woody plants alone comprise 75% of the global isoprene emitted to the atmosphere. Due to its significant influence on atmospheric chemistry, research has been focused on this C5 compound, with poplar being the most prominent model system. Recent studies indicate that isoprene can enhance thermotolerance or quench oxidative stress, while also interfering with the attraction of herbivores and parasitoids to plants. In this paper, we report on biosynthesis, regulation and function of isoprene and other stress-induced volatile isoprenoids in poplar, and discuss the future scientific challenges in this genus with respect to the importance of plant volatiles in high-density poplar biomass plantations.

Randomized, double-blind comparison of venlafaxine and sertraline in outpatients with major depressive disorder. Venlafaxine 631 Study Group

BACKGROUND

This 8-week, double-blind, randomized trial compared the efficacy and tolerability of venlafaxine and sertraline in patients with major depression.

METHOD

Outpatients (N = 147) with DSM-IV major depressive disorder and a baseline 21-item Hamilton Rating Scale for Depression (HAM-D) score of at least 18 were randomly assigned to venlafaxine, 37.5 mg b.i.d., or sertraline, 50 mg once daily. From day 15, the doses could be increased to venlafaxine, 75 mg b.i.d., or sertraline, 50 mg b.i.d. Efficacy was assessed with the 21-item HAM-D, the Montgomery-Asberg Depression Rating Scale (MADRS), and the Clinical Global Impressions scale (CGI) using a modified intent-to-treat analysis.

RESULTS

No significant differences were noted between treatments for mean HAM-D, MADRS, or CGI scores. At week 8, the HAM-D response rate was 83% with venlafaxine (N = 75) and 68% with sertraline (N = 72) (p = .05). A HAM-D score less than 10 was recorded in 68% of venlafaxine-treated and 45% of sertraline-treated patients at week 8 (p = .008). Among patients who increased their dose, the remission rate (HAM-D score < 10) was 67% with venlafaxine and 36% with sertraline at week 8 (p < .05). The overall discontinuation rate was 21% with venlafaxine and 17% with sertraline. The most common adverse events with venlafaxine were nausea, headache, and sweating and with sertraline were nausea, headache, and diarrhea.

CONCLUSION

Among patients who increased their dose, approximately twice as many experienced a remission with venlafaxine, which is a more clinically relevant endpoint than response and represents the proportion of patients who have recovered or are well.

A 12-week study comparing moclobemide and sertraline in the treatment of outpatients with atypical depression

One hundred and ninety-seven outpatients with atypical depression [Atypical Depression Diagnostic Scale (ADDS) score=4] were randomized to 12 weeks of double-blind treatment with sertraline or moclobemide in a multicentre, parallel-group clinical trial. Patients were started on either 50 mg/day sertraline or 300 mg/day moclobemide. If the therapeutic response was not satisfactory after 4 weeks, the dose could be increased to either 100 mg/day sertraline or 450 mg/day moclobemide. Primary efficacy evaluations were the 29-item Hamilton Psychiatric Rating Scale for Depression (HAM-D) and the Clinical Global Impression of Improvement (CGI-I) response rate (much or very much improved) at study endpoint. Secondary efficacy evaluations included the ADDS, the Hamilton Anxiety Scale (HAMA), the Leeds Sleep Scale, and the Battelle Quality of Life Battery (BQOLB). In the analysis of the 172 patient efficacy-evaluable population, there was significant baseline to endpoint improvement in all primary and secondary efficacy assessments after treatment with either sertraline or moclobemide. At the endpoint, the proportion of responders on CGI-I, was 77.5% in the sertraline group and 67.5% in the moclobemide group (p=0.052). The baseline to endpoint mean 29-item HAM-D score decreased from 35.9 to 14.5 in the sertraline group and from 36.3 to 16.1 in the moclobemide group. Sertraline also resulted in a significantly (p < 0.05) greater degree of improvement at the endpoint, compared with moclobemide, in the proportion of remitters on the HAMA (total score < or = 7), ADDS Category IID (Rejection Sensitivity), Leeds Sleep Factor 4 (Integrity of Behaviour Following Awakening), and on three dimensions of the BQOLB (Energy/Vitality, Social Interaction and Life Satisfaction). There were no other significant differences between treatment groups. Overall, both medications were well tolerated. In this study, both sertraline and moclobemide improved the symptoms of atypical depression.

Efficacy and tolerability of mirtazapine versus citalopram: a double-blind, randomized study in patients with major depressive disorder. Nordic Antidepressant Study Group

We aimed to compare the antidepressant and anxiolytic effects, tolerability and effects on quality of life of mirtazapine and citalopram in a randomized, double-blind, multicentre, 8-week study. Patients with a Major Depressive Episode (DSM-IV) and a baseline score of > or = 22 on the Montgomery-Asberg Depression Rating Scale (MADRS) were randomized to 8 weeks treatment with either mirtazapine (n = 137, 15-60 mg/day) or citalopram (n = 133, 20-60 mg/day). Efficacy was evaluated by the MADRS, Hamilton Anxiety Scale (HAM-A), Clinical Global Impression scales (CGI), the Leeds Sleep Evaluation Questionnaire (LSEQ) and Quality of Life Enjoyment and Satisfaction Questionnaire (QLESQ). The efficacy analyses were performed on the Intent-To-Treat Group using the Last Observation Carried Forward method. Vital signs and laboratory variables are measured and adverse events recorded at each weekly visit. The magnitude of reduction from baseline in group mean MADRS scores was large in both groups, reaching after 8 weeks of treatment mean scores of 9.1 in the mirtazapine group and 8.9 in the citalopram group. Both treatments also resulted in a substantial improvement in anxiety symptoms, sleep disturbances and quality of life, and high percentage of responders. However, at day 14, statistically significantly larger magnitudes of change favouring mirtazapine were present in the group mean MADRS, HAM-A and CGI-Severity of illness and Quality of life scores. A difference of 2.3 points on MADRS favouring mirtazapine is considered indicative for a clinically relevant superiority between two proven antidepressants. Mirtazapine treatment was also related to faster improvement of sleep, quality of sleep and improved alertness following awakening, as shown by statistically significant differences on the self-rating LSEQ at various time points. There were no differences between two treatment groups on self-rating QLSEQ. Both drugs were well tolerated, with a low number of patients in either group prematurely terminating the study due to adverse events (mirtazapine: 3.6%, citalopram, 3.0%). Sweating and nausea were statistically significantly more frequent in the citalopram group and increased appetite and complaints of weight increase in the mirtazapine group. There were no clinically relevant changes in laboratory parameters and vital sign variables with either treatment, except for clinically relevant increase in body weight, occurring more frequently in mirtazapine patients. In this study, mirtazapine and citalopram were equally effective in reducing symptoms of depression and anxiety, and well tolerated. However, mirtazapine was significantly more effective than citalopram after 2 weeks of treatment on the MADRS, HAM-A and CGI Severity of illness and Quality of life scales. This finding, consistently present at all major efficacy variables, suggests potentially faster onset of efficacy of mirtazapine over citalopram.

Moclobemide and fluoxetine for panic disorder. International Panic Disorder Study Group

An international, multicentre, double blind parallel group study compared the tolerability and efficacy of moclobemide with the selective serotonin reuptake inhibitor (SSRI) fluoxetine for panic disorder. SSRIs have been shown effective for panic. The target dose of moclobemide was 450 mg and of fluoxetine was 20 mg. There were two consecutive studies. An eight week study of acute adverse events, tolerability and efficacy was followed by a long-term extension study to 1 year. The efficacy data showed no significant difference between moclobemide and fluoxetine. Both had acute efficacy, with 63% moclobemide and 70% fluoxetine patients (ns) panic free at 8 weeks. Both agents were well tolerated to 8 weeks, but moclobemide had fewer severe adverse events (5) than fluoxetine (9). There were no severe adverse events in the extension phase with either drug, and almost all patients completing 1 year extension treatment (moclobemide 61 patients, fluoxetine 65) were much or very much improved. These data suggest moclobemide and fluoxetine are tolerated and effective for both acute panic treatment and maintenance therapy.

Moclobemide for anxiety disorders: a focus on moclobemide for panic disorder

Moclobemide is a reversible selective inhibitor of monoamine oxidase A. It has proven efficacy in a wide range of depressive disorders, including agitated anxious depression. In an international, multicentre, double-blind parallel-group study, the tolerability and efficacy of moclobemide were compared with that of the selective serotonin reuptake inhibitor fluoxetine. The target dose of moclobemide was 450 mg/day in the dose range of 300-600 mg/day, while the target dose for fluoxetine was 20 mg/day in the dose range of 10-30 mg/day. There were two consecutive studies. The first was an 8-week short-term study of acute adverse events, tolerability and efficacy. The efficacy data showed no significant difference between moclobemide and fluoxetine. Evaluation of the tolerability in a long-term study of up to 1 year is still in progress. A review of the moclobemide safety database for panic disorder with 624 patients showed a marginal increase in events with moclobemide compared with placebo for insomnia (11.2%), dizziness (4.5%) and dry mouth (3.7%), with rates for headaches and nausea lower for moclobemide than placebo. These data suggest moclobemide is a well tolerated and effective treatment for panic disorder.

Paroxetine and amitriptyline in the treatment of depression in general practice

A total of 144 outpatients in general practice in Denmark, aged 18-65 years and diagnosed as suffering from depression with a HAMD-17 score of 15 or more, were included in this 8-week double-blind, randomised, multicentre, controlled, parallel group comparison of paroxetine versus amitriptyline. The purpose of the study was primarily to evaluate efficacy and tolerance of treatment. In addition, focus was added on weight change and subjective well-being. The efficacy results showed equal effect of both drugs. However, paroxetine was tolerated better than amitriptyline, and this difference reached the level of significance when four non-evaluable patients were taken out of the analysis. Moreover, there was a significant weight increase in the amitriptyline group and no significant weight change in the paroxetine group. There was no difference between the groups as regards subjective well-being as measured by the VAS. In conclusion, paroxetine is an effective and well-tolerated antidepressant, and well-suited for the treatment of depression in general practice.

Paroxetine in the treatment of panic disorder. A randomised, double-blind, placebo-controlled study

BACKGROUND

This study compared the efficacy and tolerability of paroxetine with placebo in the treatment of panic disorder.

METHOD

After three weeks of placebo, patients received 12 weeks of treatment with paroxetine (20, 40, or 60 mg) or placebo, and finally two weeks of placebo. Dosages were adjusted according to efficacy and tolerability. Standardised cognitive therapy was given to all patients. The primary measure of outcome was reduction in the number of panic attacks.

RESULTS

Analysis of the results showed statistically significant differences in favour of paroxetine between the two treatment groups in two out of the three primary measures of outcome, i.e. 50% reduction in total number of panic attacks and number of panic attacks reduced to one or zero over the study period. For the third measure of outcome, the mean change in the total number of attacks from baseline, there was a positive trend in favour of paroxetine. The results of the primary measures of outcome were strongly supported by the results of the secondary efficacy measures of outcome. In addition, paroxetine, at all doses, was very well tolerated.

CONCLUSION

Paroxetine plus cognitive therapy was significantly more effective than placebo plus cognitive therapy in the treatment of panic disorder.

A comparison of fluoxetine and imipramine in the treatment of outpatients with major depressive disorder

A double-blind clinical trial was undertaken to evaluate the clinical efficacy and safety of fluoxetine compared with imipramine in the treatment of 59 outpatients suffering from major depressive disorder. The mean scores of all depression rating scales showed that the drugs had comparable efficacy. The side effect profile of imipramine was found to be mainly anticholinergic, which was not the case for fluoxetine, where it was mainly found to be gastrointestinal, such as nausea and diarrhoea. In both groups the total number of adverse events reported were the same. Fluoxetine treatment resulted in weight loss, whereas imipramine treatment resulted in a slight but significant weight increase.

Agreement in psychiatric assessment

In 103 schizophrenic patients we investigated the extent of practice needed in the use of the Brief Psychiatric Rating Scale (BPRS) to enable its reliability to be assessed. The agreement level of the 7 raters was analysed. Generally, the lowest mean agreement found was for the negative symptoms of the BPRS schizophrenia subscale. A high degree of agreement was attained both for the positive symptoms of the BPRS schizophrenia subscale and for the symptoms of the depression--and of the mania subscale. The degree of disagreement observed was due to both individual differences in assessment ability and the rating procedure. These results indicate that it is necessary to state the degree of agreement achieved in studies in which several raters are taking part.

The Brief Psychiatric Rating Scale. Dimension of schizophrenia--reliability and construct validity

This study has focussed on a 10-item Brief Psychiatric Rating Scale (BPRS) subscale for the quantification of schizophrenic states. Seven psychiatrists interviewed jointly patients who all fulfilled the DSM-III criteria of schizophrenia, and in a subsequent pencil-and-paper procedure a judgment analysis was performed. The reliability analysis showed that less experienced BPRS raters made less consistent judgments implying the cautionary statement that the proper use of a scale for schizophrenia requires specialized training with the scale. The validity analysis showed that the BPRS items had an additive relationship implying that the sum of these items is a sufficient statistic for the measurement of severity of schizophrenic states. Finally, the results seem to indicate, that the underlying dimension defined by the 10-items BPRS subscale includes hierarchically the negative and positive symptoms of schizophrenia.

An ethological analysis of depression: comparison between ethological recording and Hamilton rating of five endogenously depressed patients

Five patients who had all been diagnosed as endogenously depressed at admission were rated twice a week and observed ethologically for 4 h/week during the entire hospitalization (4-11 weeks). Observations were carried out in the actual social environment of the ward. Data were analysed based on the parameters of behaviour diversity, behaviour activity, and marker elements. Depression was scored as low values of diversity and activity; improvement corresponded to higher values of these parameters. As possible markers of improvement, 8 behavioural elements have been singled out. One patient constituted a special case: at discharge she was rated as completely recovered; however, the ethological data indicated a serious aggravation. The day after discharge the patient attempted to commit suicide. It is concluded that ethological psychiatric research may be able to supplement traditional psychiatry with decisive information in the areas of diagnosis and treatment assessment.

An ethological description of depression

During the last 20 years ethological psychiatric research has developed a working method for the systematic and quantitative recording and analysis of the nonverbal behaviour of psychiatric patients in their actual hospital environment. In this study this method was used to follow changes in the behaviour pattern of 5 depressed, hospitalized patients during their entire hospital stay. Parallel to ethological recording, patients were rated according to Hamilton twice a week. The patients who were most depressed at admission showed the greatest behavioural changes; the changes were most conspicuous in the behavioural elements representing social contact and communication. One patient who obviously developed a new depression during the observation period without this being recognized by the Hamilton rating or the clinical control, seemed to have been better described by the behaviour recording. This study shows that ethological psychiatric methods are very suitable for obtaining a better basis for the observations of the staff in the ward environment.

Altered balance in the autonomic nervous system in schizophrenic patients

The aim of the present study was to evaluate the autonomic nervous function in schizophrenic patients. Twenty-eight patients (29 +/- 6 years) diagnosed as schizophrenics and in stable medication were included, together with ten schizophrenic patients (25 +/- 5 years) who were unmedicated. Eleven healthy subjects (32 +/- 7 years) served as controls. Immediate heart-rate responses to a single deep inspiration was used as a measure of parasympathetic function. Heart-rate response to standing was used as a measure of sympathetic function. Supine blood pressure, heart-rate and orthostatic changes in blood pressure did not differ between groups. Heart-rate response to standing was greater in both medicated and non-medicated schizophrenics compared to normal subjects (P less than 0.01). Heart-rate response to standing was greater in non-medicated compared to medicated schizophrenics (P less than 0.05). Heart-rate response to inspiration was greater in non-medicated schizophrenics compared to normal subjects (P less than 0.05), whereas no difference was found between medicated and non-medicated schizophrenics. The results show that the balance in the autonomic nervous system is altered in schizophrenic patients with a hyperexcitability in both the sympathetic and the parasympathetic division. Our study has thus indicated a dysfunction in the autonomic nervous system per se and the previous interpretations of attentional orienting responses in schizophrenia is questioned. Medication with neuroleptics seems to partly normalize the autonomic reactivity rather than being the cause of autonomic dysfunction.

[Angiography findings following myocardial infarct in young females: the role of oral contraceptives]

In 173 women less than 50 years of age with myocardial infarction, angiographic evidence of coronary sclerosis was observed in only 108 (62%). Completely normal coronary arteries were found in 15 patients (9%) and in 50 patients (29%) an isolated poorly delineated stenosis was found in the presence of otherwise completely normal coronary arteries. Of the 65 patients with myocardial infarction but without typical coronary sclerosis, 47 (72%) were taking oral contraceptives at the time of infarction. In 60% of the oral contraceptive users with infarction, angiographically, there was no evidence of typical coronary sclerosis. With the exception of cigarette smoking, the number of atherogenic risk factors in these patients was low such that myocardial infarction during treatment with oral contraceptives may possibly represent a separate disease entity distinguishable from coronary sclerosis. In support of this, in some cases, repeat angiography demonstrated spontaneous regression of the isolated stenosis. Etiologically, possible thromboembolic vascular occlusion has been assumed. In women in the premenopausal years, coronary sclerosis is uncommon and usually associated with a substantial number of atherogenic risk factors. In this case, 29% of the women had used oral contraceptives, the causal role of which remains uncertain. Even though oral contraceptive use is associated with a higher risk of myocardial infarction, apparently, it cannot be regarded as a typical atherogenic risk factor.

Sulpiride and haloperidol in schizophrenia: a double-blind cross-over study of therapeutic effect, side effects and plasma concentrations

In a double-blind cross-over trial, 20 chronic schizophrenic patients were treated with sulpiride and haloperidol in two 12-week periods. The final median dose of sulpiride was 2000 mg/day (range 800-3200) and of haloperidol 12 mg/day (range 6-24). Sulpiride had an antipsychotic effect and therapeutic profile not significantly different from that of haloperidol. In spite of the high doses of sulpiride, extrapyramidal side-effects were seen less frequently during the first four weeks of the sulpiride period than during the corresponding haloperidol period (P less than 0.05), whereas autonomic side-effects were equally rare for both drugs. A positive correlation was found between daily dose and plasma concentration of both sulpiride (P less than 0.001) and haloperidol (P less than 0.05), but no correlation could be established between clinical effects and plasma levels of either neuroleptic.

Sulpiride versus haloperidol, a clinical trial in schizophrenia. A preliminary report

Sixteen out of 25 hebephrenic and paranoid schizophrenic patients completed a double-blind cross-over study with sulpiride and haloperidol. The patient sample was relatively chronic: Median age was 35 years (range 26-53 years), median duration of illness 10 years (4-35 years), and median duration of neuroleptic treatment 5 years (1-28 years). Each patient was treated with sulpiride/haloperidol in random order for 12 weeks with a drug-free period before each treatment phase. Mean total BPRS (Brief Psychiatric Rating Scale) score was reduced from 25 to 15 (P less than 0.05) during sulpiride (800-2800 mg/day, median 1600 mg/day), and from 28 to 15 (P less than 0.01) during haloperidol (6-18 mg/day, median 12). There were no significant differences between the groups with respect to total BPRS score, single items or symptom clusters. However, in a few, very "chronic", disturbed, and long-term treated patients, haloperidol appeared more beneficial than sulpiride. Autonomic side effects and parkinsonism tended to occur more frequently during haloperidol than during sulpiride, but no significant differences were found. It is concluded that sulpiride, a specific dopamine-2 receptor blocker, has antipsychotic effect, not significantly different from haloperidol, but may produce slightly less side effects.

[Is there any evidence that the maternal HPL serum-concentration is of prognostic value in cases of threatened abortion? (author's transl)]

The mean values of the maternal HPL are significantly decreased in cases of threatened abortion from the 10th to the 16th week post menstruation. But the HPL concentration is only of prognostic value after the 13th week because only after that time the HPL concentration is significantly decreased in cases with following abortion. The common therapy with gestagens or with a combination of estrogens and gestagens has no influence of the mean HPL concentrations. For the first time it could be shown an influence of an exogen estrogen-gestagen combination on the individual values of HPL serum-concentrations.

[The treatment of threatened abortion (author's transl)]

In a prospective study 265 patients with threatened abortions were divided into 2 groups. One group of 134 patients received treatment with Oestradiol benzoat and hydroxyprogesterone capronat. The other group of 131 patients received no hormonal treatment. Of the group treated with hormones 40.7% of the women had an abortion. Of the group treated with placebos 39.7% of the patients had an abortion. There was therefore no difference in the success rate of the treatment of threatened abortion irrespective of the administration of hormones or placebos. The value of hormonal therapy in the treatment of threatened abortion is therefore questionable.