ESCRT components ISTL1 andLIP5 are required for tapetal function and pollen viability

Pollen wall assembly is crucial for pollen development and plant fertility. The durable biopolymer sporopollenin and the constituents of the tryphine coat are delivered to developing pollen grains by the highly coordinated secretory activity of the surrounding tapetal cells. The role of membrane trafficking in this process, however, is largely unknown. In this study, we used Arabidopsis thaliana to characterize the role of two late-acting endosomal sorting complex required for transport (ESCRT) components, ISTL1 and LIP5, in tapetal function. Plants lacking ISTL1 and LIP5 form pollen with aberrant exine patterns, leading to partial pollen lethality. We found that ISTL1 and LIP5 are required for exocytosis of plasma membrane and secreted proteins in the tapetal cells at the free microspore stage, contributing to pollen wall development and tryphine deposition. Whereas the ESCRT machinery is well known for its role in endosomal trafficking, the function of ISTL1 and LIP5 in exocytosis is not a typical ESCRT function. The istl1 lip5 double mutants also show reduced intralumenal vesicle concatenation in multivesicular endosomes in both tapetal cells and developing pollen grains as well as morphological defects in early endosomes/trans-Golgi networks, suggesting that late ESCRT components function in the early endosomal pathway and exocytosis.

A seed coat-specific β-ketoacyl-CoA synthase, KCS12, is critical for preserving seed physical dormancy

Physical dormancy in seeds exists widely in seed plants and plays a vital role in maintaining natural seed banks. The outermost cuticle of the seed coat forms a water-impermeable layer, which is critical for establishing seed physical dormancy. We previously set up the legume plant Medicago truncatula as an excellent model for studying seed physical dormancy, and our studies revealed that a class II KNOTTED-like homeobox, KNOX4, is a transcription factor critical for controlling hardseededness. Here we report the function of a seed coat β-ketoacyl-CoA synthase, KCS12. The expression level of KCS12 is significantly downregulated in the knox4 mutant. The KCS12 gene is predominantly expressed in the seed coat, and seed development in the M. truncatula kcs12 mutant is altered. Further investigation demonstrated that kcs12 mutant seeds lost physical dormancy and were able to absorb water without scarification treatment. Chemical analysis revealed that concentrations of C24:0 lipid polyester monomers are significantly decreased in mutant seeds, indicating that KCS12 is an enzyme that controls the production of very long chain lipid species in the seed coat. A chromatin immunoprecipitation assay demonstrated that the expression of KCS12 in the seed coat is directly regulated by the KNOX4 transcription factor. These findings define a molecular mechanism by which KNOX4 and KCS12 control formation of the seed coat and seed physical dormancy.

Apoplastic lipid barriers regulated by conserved homeobox transcription factors extend seed longevity in multiple plant species

Cutin and suberin are lipid polyesters deposited in specific apoplastic compartments. Their fundamental roles in plant biology include controlling the movement of gases, water and solutes, and conferring pathogen resistance. Both cutin and suberin have been shown to be present in the Arabidopsis seed coat where they regulate seed dormancy and longevity. In this study, we use accelerated and natural ageing seed assays, glutathione redox potential measures, optical and transmission electron microscopy and gas chromatography-mass spectrometry to demonstrate that increasing the accumulation of lipid polyesters in the seed coat is the mechanism by which the AtHB25 transcription factor regulates seed permeability and longevity. Chromatin immunoprecipitation during seed maturation revealed that the lipid polyester biosynthetic gene long-chain acyl-CoA synthetase 2 (LACS2) is a direct AtHB25 binding target. Gene transfer of this transcription factor to wheat and tomato demonstrated the importance of apoplastic lipid polyesters for the maintenance of seed viability. Our work establishes AtHB25 as a trans-species regulator of seed longevity and has identified the deposition of apoplastic lipid barriers as a key parameter to improve seed longevity in multiple plant species.

PRX2 and PRX25, peroxidases regulated by COG1, are involved in seed longevity in Arabidopsis

Permeability is a crucial trait that affects seed longevity and is regulated by different polymers including proanthocyanidins, suberin, cutin and lignin located in the seed coat. By testing mutants in suberin transport and biosynthesis, we demonstrate the importance of this biopolymer to cope with seed deterioration. Transcriptomic analysis of cog1-2D, a gain-of-function mutant with increased seed longevity, revealed the upregulation of several peroxidase genes. Reverse genetics analysing seed longevity uncovered redundancy within the seed coat peroxidase gene family; however, after controlled deterioration treatment, seeds from the prx2 prx25 double and prx2 prx25 prx71 triple mutant plants presented lower germination than wild-type plants. Transmission electron microscopy analysis of the seed coat of these mutants showed a thinner palisade layer, but no changes were observed in proanthocyanidin accumulation or in the cuticle layer. Spectrophotometric quantification of acetyl bromide-soluble lignin components indicated changes in the amount of total polyphenolics derived from suberin and/or lignin in the mutant seeds. Finally, the increased seed coat permeability to tetrazolium salts observed in the prx2 prx25 and prx2 prx25 prx71 mutant lines suggested that the lower permeability of the seed coats caused by altered polyphenolics is likely to be the main reason explaining their reduced seed longevity.

Constructing functional cuticles: analysis of relationships between cuticle lipid composition, ultrastructure and water barrier function in developing adult maize leaves

BACKGROUND AND AIMS

Prior work has examined cuticle function, composition and ultrastructure in many plant species, but much remains to be learned about how these features are related. This study aims to elucidate relationships between these features via analysis of cuticle development in adult maize (Zea mays L.) leaves, while also providing the most comprehensive investigation to date of the composition and ultrastructure of adult leaf cuticles in this important crop plant.

METHODS

We examined water permeability, wax and cutin composition via gas chromatography, and ultrastructure via transmission electron microscopy, along the developmental gradient of partially expanded adult maize leaves, and analysed the relationships between these features.

KEY RESULTS

The water barrier property of the adult maize leaf cuticle is acquired at the cessation of cell expansion. Wax types and chain lengths accumulate asynchronously over the course of development, while overall wax load does not vary. Cutin begins to accumulate prior to establishment of the water barrier and continues thereafter. Ultrastructurally, pavement cell cuticles consist of an epicuticular layer, and a thin cuticle proper that acquires an inner, osmiophilic layer during development.

CONCLUSIONS

Cuticular waxes of the adult maize leaf are dominated by alkanes and alkyl esters. Unexpectedly, these are localized mainly in the epicuticular layer. Establishment of the water barrier during development coincides with a switch from alkanes to esters as the major wax type, and the emergence of an osmiophilic (likely cutin-rich) layer of the cuticle proper. Thus, alkyl esters and the deposition of the cutin polyester are implicated as key components of the water barrier property of adult maize leaf cuticles.

Functional Overlap of Long-Chain Acyl-CoA Synthetases in Arabidopsis

Long-chain acyl-CoA synthetases (LACSs) play diverse and essential roles in lipid metabolism. The genomes of model eukaryotic organisms encode multiple LACS genes, and the substrate specificities of LACS homologs often overlap substantially. Homologous LACSs tend to differ in their expression patterns, localizations, and, by extension, the metabolic pathways to which they contribute. The Arabidopsis genome encodes a family of nine LACS genes, which have been characterized largely by reverse genetic analysis of mutant phenotypes. Because of redundancy, distinguishing the contributions of some Arabidopsis LACS genes has been challenging. Here, we have attempted to clarify the functions of LACSs that functionally overlap by synopsizing the results of previous work, isolating a suite of higher-order mutants that were previously lacking, and analyzing oil, wax, cutin, cuticle permeability, fertility and growth phenotypes. LACS1, LACS2, LACS4, LACS8 and LACS9 all affect cuticular lipid metabolism, but have different precise roles. Seed set, seed weight and storage oil amounts of higher-order lacs1, lacs2, lacs4, lacs8 and lacs9 mutants vary greatly, with these traits subject to different effects of fertility and oil synthesis defects. LACS4, LACS8 and LACS9 have partially redundant roles in development, as lacs4 lacs8 and lacs4 lacs9 double mutants are dwarf. lacs4 lacs8 lacs9 triple mutants were not recovered, and are assumed to be non-viable. Together, these results sketch a complex network of functions and functional interactions within the Arabidopsis LACS gene family.

Translating Immunopeptidomics to Immunotherapy-Decision-Making for Patient and Personalized Target Selection

Immunotherapy is revolutionizing cancer treatment and has shown success in particular for tumors with a high mutational load. These effects have been linked to neoantigens derived from patient-specific mutations. To expand efficacious immunotherapy approaches to the vast majority of tumor types and patient populations carrying only a few mutations and maybe not a single presented neoepitope, it is necessary to expand the target space to non-mutated cancer-associated antigens. Mass spectrometry enables the direct and unbiased discovery and selection of tumor-specific human leukocyte antigen (HLA) peptides that can be used to define targets for immunotherapy. Combining these targets into a warehouse allows for multi-target therapy and accelerated clinical application. For precise personalization aimed at optimally ensuring treatment efficacy and safety, it is necessary to assess the presence of the target on each individual patient's tumor. Here we show how LC-MS paired with gene expression data was used to define mRNA biomarkers currently being used as diagnostic test IMADETECT™ for patient inclusion and personalized target selection within two clinical trials (NCT02876510, NCT03247309). Thus, we present a way how to translate HLA peptide presentation into gene expression thresholds for companion diagnostics in immunotherapy considering the peptide-specific correlation to its encoding mRNA.

A gateway towards non-collinear spin processing using three-atom magnets with strong substrate coupling

A cluster of a few magnetic atoms on the surface of a nonmagnetic substrate is one suitable realization of a bit for spin-based information technology. The prevalent approach to achieve magnetic stability is decoupling the cluster spin from substrate conduction electrons in order to suppress destabilizing spin-flips. However, this route entails less flexibility in tailoring the coupling between the bits needed for spin-processing. Here, we use a spin-resolved scanning tunneling microscope to write, read, and store spin information for hours in clusters of three atoms strongly coupled to a substrate featuring a cloud of non-collinearly polarized host atoms, a so-called non-collinear giant moment cluster. The giant moment cluster can be driven into a Kondo screened state by simply moving one of its atoms to a different site. Using the exceptional atomic tunability of the non-collinear substrate mediated Dzyaloshinskii–Moriya interaction, we propose a logical scheme for a four-state memory.

Information technology based on few atom magnets requires both long spin-energy relaxation times and flexible inter-bit coupling. Here, the authors show routes to manipulate information in three-atom clusters strongly coupled to substrate electrons by exploiting Dzyaloshinskii–Moriya interactions.

Abstract 2291: On- and off target toxicity profiling for adoptive cell therapy by mass spectrometry-based immunopeptidome analysis of primary human normal tissues

A major constraint for the broad and safe application of Adoptive Cellular Therapy (ACT) is the limited number of validated tumor targets, especially for solid tumors. For T-cell receptor (TCR)-based approaches, presentation of targeted HLA-peptides on normal tissues can lead to on-target toxicity, such as severe inflammatory colitis reported upon re-directing T cells to an HLA-A*02 restricted carcinoembryonic antigen (CEA) epitope. Independently, off-target cross-reactivity of TCRs occurred in previous ACT trials, e.g. when a MAGEA3-directed TCR cross-recognized an HLA-A*01 restricted epitope from titin expressed on heart, which led to fatal cardiac toxicities. Here we present a novel approach allowing the prediction of severe on- and off-target side effects before entering into clinical trials.

We used a target discovery engine (XPRESIDENT) combining highly sensitive, quantitative mass spectrometry (LC-MS/MS), RNA-Seq-based differential transcriptomics, immunology and bioinformatics to characterize the human immunopeptidome directly on shock frozen primary human tissues. Over the last years we have built an according database for > 600 tumor samples from > 20 different tumor types and, importantly, > 300 samples from > 40 different normal tissue types, resulting in hundreds of thousands of unique HLA-peptide sequences. These data allow conclusions on which HLA peptides are actually presented on primary normal tissues in a quantitative manner, taking into account relative differences between normal tissues and tumors as well as absolute peptide copy numbers per cell. In order to assess the off-target risk for a TCR, we predict all theoretical HLA- and TCR-binding peptides in the proteome, ideally based on the binding motif of the TCR, and specifically search for actual peptide presentation by normal tissues.

When analyzing the above described CEA case, we were able to detect the CEA-derived peptide IMIGVLVGV on HLA-A*02 positive colorectal cancer samples, but importantly also on normal colorectal samples. In the original study describing the titin case tremendous experimental efforts and sophisticated cell culture models were required to retrospectively identify cross-recognition of the peptide on cardiomyocytes as the cause of toxicity. In contrast, with our approach we easily and directly identified the critical peptide ESDPIVAQY as one of the most abundantly presented peptides on an HLA-A*01 positive primary human heart sample. We show that this approach can lead to noteworthy results also for other pre-clinical and clinical stage TCR candidates.

In conclusion our data demonstrate that ultrasensitive LC-MS/MS of primary tissue may represent a fast, straightforward and meaningful complementary method to common in vitro or animal models for the prediction of on- and off-target toxicities in TCR-based immunotherapy approaches.

Citation Format: Oliver Schoor, Jens Fritsche, Sarah Kutscher, Andrea Mahr, Lea Stevermann, Annika Sonntag, Franziska Hoffgaard, Dominik Vahrenhorst, Julia Leibold, Valentina Goldfinger, Leonie Alten, Sebastian Bunk, Dominik Maurer, Steffen Walter, Hans-Georg Rammensee, Harpreet Singh-Jasuja, Toni Weinschenk. On- and off target toxicity profiling for adoptive cell therapy by mass spectrometry-based immunopeptidome analysis of primary human normal tissues. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2291.

Thermal stability of an interface-stabilized skyrmion lattice

The thermal stability of the magnetic nano-skyrmion lattice in the monolayer Fe/Ir(111) is investigated using temperature dependent spin-polarized scanning tunneling microscopy. Our experiments show that the skyrmion lattice disappears at a temperature of T_{c}=27.8  K, indicating a loss of long-range magnetic order. At second-layer iron islands the lattice is pinned and local order persists at temperatures above T_{c}. The findings are explained in terms of the complex magnetic interactions involved in the formation of the skyrmion lattice.

Electric-field-induced magnetic anisotropy in a nanomagnet investigated on the atomic scale

Magnetoelectric coupling is studied using the electric field between the tip of a spin-polarized scanning tunneling microscope and a nanomagnet. Our experiments show that a negative (positive) electric field stabilizes (destabilizes) in-plane magnetization against thermal agitation, whereas it destabilizes (stabilizes) out-of-plane magnetization. We conclude that the electric field E induces a uniaxial anisotropy that favors in-plane magnetization for E<0 and out-of-plane magnetization for E>0. Our experiments demonstrate magnetic manipulation on the atomic scale without exploiting spin or charge currents.

Scanning noise microscopy

The paper describes a simple scheme enabling the real-time characterization of fluctuations, e.g., of the conductance in scanning tunneling microscopy. The technique can be used in parallel to other data acquisition, evaluating the rate, the amplitude, and the duty cycle of telegraphic noise in the tunneling current. This kind of scanning probe microscopy allows to evaluate the noise parameters as a function of the average tunneling current, the electron energy, and the lateral position. Images of the noise with Ångstrom spatial resolution are acquired simultaneously to the topographic information providing a direct correlation between the structural information and the noise. The method can be applied to a large variety of systems to monitor dynamics on the nanoscale, e.g., the localization of tunneling current induced switching within a single molecule. Noise spectroscopy may reveal the involved molecular orbitals, even if they cannot be resolved in standard scanning tunneling spectroscopy. As an example we present experimental data of the organic molecule copper phthalocyanine on a Cu(111) surface [J. Schaffert, M. C. Cottin, A. Sonntag, H. Karacuban, C. A. Bobisch, N. Lorente, J.-P. Gauyacq, and R. Möller, Nature Mater. 12, 223-227 (2013)].

[Quality management in psychiatry: evaluation of an ergotherapeutical questionnaire before and after treatment]

In analogy to somatic medicine, modern psychiatry strives to measure the outcome of treatment and care. In order to warrant an effective therapy, this request is reasonable from the standpoint of both the therapist and the patient as well as hospitals or insurance companies. However, how can I measure friendliness, empathy or humanity, the "being available for somebody"? For sure, psychiatric DRGs, which connote efficacy based on periods of time, are by no means suitable. The present study analyses routine clinical data of an ergotherapeutic questionnaire, as an aid to estimating treatment quality. The naturalistic character of this data collection during daily routine may be an advantage to assessing the quality of results in psychiatry.

Joule heating and spin-transfer torque investigated on the atomic scale using a spin-polarized scanning tunneling microscope

The influence of a high spin-polarized tunnel current onto the switching behavior of a superparamagnetic nanoisland on a nonmagnetic substrate is investigated by means of spin-polarized scanning tunneling microscopy. A detailed lifetime analysis allows for a quantification of the effective temperature rise of the nanoisland and the modification of the activation energy barrier for magnetization reversal, thereby using the nanoisland as a local thermometer and spin-transfer torque analyzer. Both the Joule heating and spin-transfer torque are found to scale linearly with the tunnel current. The results are compared to experiments performed on lithographically fabricated magneto-tunnel junctions, revealing a very high spin-transfer torque switching efficiency in our experiments.

[Presenile dementia in memory clinics--incidence rates and clinical features]

This study describes the clinical features of presenile dementia diagnosed in memory clinics. It further gives an estimate of the declared incidence for the German city of Munich and surrounding counties. Twelve memory clinics in Switzerland and Germany were considered, among them all of the four in Munich. A total of 267 patients with onset of illness under the age of 65 were included. Only 16 patients (6%) were younger than 50. Men and women were affected about equally often. The most common cause of dementia was Alzheimer's disease (67%), followed by frontotemporal degeneration (13.5%) and vascular (5.6%) dementia. The declared incidence was estimated at 8.3 new cases of dementia per year among 100,000 persons in the 50-64 age range, with an incidence rate of Alzheimer's disease at 6.3/100,000. It can be concluded that memory clinics fulfill an important function in the care of patients with presenile dementia, since they are highly utilized by younger patients in early stages of the illness.

Does the Context Matter? Utilization of Sedative Drugs in Nursing Homes - A Multilevel Analysis

BACKGROUND

The aim of this study is to assess the utilization of sedative drugs in nursing homes by means of a multilevel approach taking into account individual as well as institutional characteristics.

METHODS

A retrospective chart review of the drugs consumed in nursing homes in an urban region of Germany was conducted. Individual characteristics were measured by analyzing nursing home files, by staff assessment and by a structured interview conducted by trained psychologists and physicians. Institutional characteristics were assessed by interviewing the management of each facility and ward and by using a staff questionnaire survey. The sample consisted of 1903 residents from 27 nursing homes with a total of 96 wards. Data analysis was carried out by means of a multilevel analysis, a strategy for analyzing hierarchically structured data.

RESULTS

The utilization of sedative drugs (low potency neuroleptics, anxiolytics, hypnotics) in nursing homes is remarkably high. Thus, 33.3 % of the residents used sedative drugs on a regular basis. PRN prescriptions existed for 13.1 % of the residents, 5.3 % had been using sedative medication prescribed as PRN. Results indicate the influence of individual as well as institutional characteristics on residents' sedative drug utilization. In particular, the use of PRN medicine is determined by characteristics of the ward the individuals are living in.

CONCLUSION

Methodological implications: The data analysis concerning the drug utilization of residents of nursing homes requires multilevel models and a distinction between regular and PRN medicine. Further research should focus on explaining institutional variance.

PRACTICAL IMPLICATIONS

Staff training in nonpharmacological strategies to manage disturbing behavior of residents is required.

Depression during therapy with interferon alpha--how long should an antidepressant treatment last?

Although depressive symptoms are well-known side effects of interferon alpha (IFNalpha), it is uncertain if these symptoms decline with the cessation of IFNalpha therapy. We report on a 47-year-old man who, apart from former drug abuse, never had suffered from a psychiatric disorder. However, he had a family history burdened with the suicide of his mother and his twin sister. After a depressive symptomatology during the IFNalpha therapy, which had been tolerably treated by mirtazapine, he committed a suicide attempt six months after the parallel termination of IFNalpha and antidepressant treatment. Two aspects of this case report should be emphasised. First, patients with an increased risk for psychiatric complications of interferon therapy must be followed closely for a depressive symptomatology and treated aggressively if symptoms arise. Second, this case report shows the relapse of depressive symptoms far beyond the end of the interferon treatment. If an antidepressant treatment is necessary during IFNalpha therapy this should not be stopped prematurely with the termination of the interferon medication.

[Wishes of nursing home residents concerning their life situation--results of a qualitative study]

OBJECTIVE

This study examined the wishes of nursing home residents concerning their life situation in the nursing home.

METHODS

Using a qualitative study design, a representative sample of nursing home residents (n = 1656) of 24 nursing homes in a city situated in the eastern part of Germany were interviewed.

RESULTS

The analyses of residents' wishes lead to major domains such as the quality of care, interpersonal contact, architecture and organization of the house, diversification, financial support, as well as themes like health and death and the wish to leave the nursing home. Residents focus on an individualized approach to care.

CONCLUSIONS

Nursing home residents' views support the need to improve the psychological and social aspects of the quality of care. Implications of and consequences for the organization of care and concepts of nursing are discussed.

State markers of depression in sleep EEG: dependency on drug and gender in patients treated with tianeptine or paroxetine

Tianeptine enhances while paroxetine inhibits serotonin reuptake into neurons; however, both show an antidepressive action. A subgroup of 38 depressed patients from a drug trial comparing the efficacy of tianeptine with that of paroxetine was studied with regard to their effects on sleep regulation, especially in relation to treatment response. We recorded sleep EEGs at day 7 and day 42 after the start of treatment with either compound, which allows measurement of changes due to the antidepressive medication in relation to the duration of treatment. Spectral analysis of the non-REM sleep EEG revealed a strong decline in the higher sigma frequency range (14-16 Hz) in male treatment responders independent of medication, whereas nonresponders did not show marked changes in this frequency range independent of gender. The patients receiving paroxetine showed less REM sleep and more intermittent wakefulness compared to the patients receiving tianeptine. REM density after 1 week of treatment was a predictor of treatment response in the whole sample. Psychopathological features with regard to the score in single items of the HAMD revealed predictive markers for response, some of which were opposite in the gender groups, especially those related to somatic anxiety. Changes in REM density were inversely correlated to the changes in HAMD in the paroxetine, but not the tianeptine, group. Our data suggest the importance of taking gender into account in the study of the biological effects of drugs. The study further points to the importance of the higher sigma frequency range in the sleep EEG of non-REM sleep and REM density as a marker of treatment response.

Clinical outcome after trimipramine in patients with delusional depression - a pilot study

The treatment of delusional depression is a major challenge in psychopharmacology. Hypothalamic-pituitary-adrenocortical (HPA) overdrive may contribute, via increased dopaminergic activity, to the pathophysiology of the disorder. Trimipramine appears to be an interesting potential candidate, since it is an atypical antidepressant that is known to inhibit HPA activity. In a four-week open trial we investigated its effects in 15 inpatients with delusional depression. The dosage was increased within 7 days up to 300 - 400 mg/d and was then maintained for three weeks. Psychometric assessments and safety monitoring were conducted weekly. Assessment of the HPA activity was achieved by a combined dexamethasone suppression/corticotropin-releasing hormone stimulation (Dex/CRH) test before and after four weeks of treatment. Therapeutic response was defined as a decrease in the HAMD-score of at least 50 %. Eight out of 13 completers were rated as responders. Therapeutic response was associated with L, D-trimipramine concentrations higher than 160 ng/ml. Intent-to-treat analysis showed significant improvement in psychometric variables. Despite the high dosage, the substance was generally well tolerated, with the exception of one patient who suffered from a hypotensive reaction. Mean +/- SD concentration of L-trimipramine and D-trimipramine were 138 +/- 61 ng/ml and 119 +/- 50 ng/ml at a final dose of 346 +/- 50 mg/d. The ACTH and cortisol area under the curve in the Dex/CRH tests decreased significantly, reflecting a decrease of activity in the HPA system. We suggest that the clinical use of high-dose trimipramine in delusional depression seems to be a promising treatment strategy.

[Determinants of psychotropic drug utilization in homes for the elderly and in nursing homes]

A large proportion of the residential and nursing home population is mentally ill. The causes for increased prescription of psychotropic drugs other than mental disorders have been discussed. This study presents data on the role of the individual's characteristics and institutional conditions on psychotropic drug use in residents of residential and nursing homes. Therefore the psychotropic drug use of 4 old-people's homes in Leipzig (Germany) was reviewed. Sociodemographic characteristics and a number of behavioral patterns of the residents were examined. Regression analysis revealed associations of age, gender and certain behavioral patterns (e.g., agitation, insomnia with nightly disturbances) and psychotropic drug use. Beyond that, psychotropic drug use varied among the 4 institutions' practices. Further research should be aimed at gaining insight into the interplay of these individual and institutional influences on psychotropic drug use in order to develop specific interventions to optimize treatment.

Cortisol response in the combined dexamethasone/CRH test as predictor of relapse in patients with remitted depression. a prospective study

The development and course of depression is causally linked to impairment of central regulation of the hypothalamic-pituitary-adrenocortical (HPA) system. Previous research documented that the combined dexamethasone/corticotropin-releasing hormone (DEX/CRH) test identifies HPA dysfunction with high sensitivity. We evaluated the predictive validity for medium-term outcome of the cortisol response in the combined DEX/CRH test in 74 remitted patients previously suffering from major depressive disorder. Of the 74 patients, 61 remained in stable remission and 13 relapsed during the first 6 months after discharge from the hospital. Although the cortisol and ACTH responses in the DEX/CRH test did not differ between the two groups of patients on admission, the responses differed significantly just before discharge (P< 0.05). We defined two dichotomous variables as prediction rules indicating (1) the change between admission and discharge in the cortisol response to the DEX/CRH test, and (2) the effect of the CRH infusion on cortisol as compared to the baseline level in the DEX/CRH test prior to discharge only. An elevated cortisol response in the DEX/CRH test was correlated with a four- to six-fold higher risk for relapse than in individuals with a normal cortisol response. The two proposed rules for predicting relapse within the first 6 months after discharge could be optimized by including age and gender. Hence, an exaggerated cortisol response in the combined DEX/CRH test predicts the recurrence of depressive psychopathology. The test performance can be further optimized if gender and age are taken into account.

Involvement of CCK in the paraventricular nucleus of the hypothalamus in the CNS regulation of colonic motility

The effects of cholecystokinin octapeptide (CCK(8)), the CCK-A receptor antagonist, MK-329, and the CCK-B receptor antagonist, L-365, 260, microinfused into the paraventricular nucleus of hypothalamus (PVN) on colonic motor function was investigated in awake rats, chronically implanted with a microinjection cannula into the PVN and a catheter into the proximal colon. In fasted rats, bilateral microinfusion of CCK(8) at doses of 1.5 and 3.0 microg/rat into the PVN stimulated colonic transit, as shown by a significant increase in the geometric center by 47 and 54%, respectively. This effect of CCK(8) was site-specific to the PVN, since microinjection of the peptide into sites outside of but adjacent to PVN had no effect. In non-fasted rats, L-365,260 bilaterally microinjected into the PVN at a dose of 1.5 microg/rat inhibited propulsive colonic motor function; colonic transit time significantly increased by 73% in comparison to the control condition. Microinfusion of the CCK-A antagonist into in the PVN did not affect colonic transit. These results show that the PVN is a responsive site for the central CCK(8)-induced modulation of colonic motility. The data suggest, that endogenous CCK in the paraventricular nucleus of the hypothalamus unfolds a stimulatory effect on colonic transit through action on CCK-B receptors.

Enhanced long-latency somatosensory potentials in major depressive disorder

Bodily misperceptions are a frequent symptom in major depressive disorder. A reduced ability to deflect attention from somatosensory stimuli may contribute to the generation of unpleasant bodily sensations and co-occur with altered habituation of the brain electric reactions to somatosensory stimuli. The aim of the present study was to explore whether attention-related components of somatosensory evoked potentials (SSEP) and the habituation of these components are altered in major depression. Fifteen patients with major depressive disorder were compared to an age- and gender-matched group of 15 healthy controls. A series of identical, intrusive but not painful electric stimuli were applied to the left index finger for 48 min. Averaged SSEP were computed from multichannel EEG recordings for consecutive recording blocks of the experiment, each block containing 162 stimuli. Based on these data the habituation process of late components of the SSEP was analysed in two latency intervals (50-150, 170-370 ms). Patients showed significantly enhanced reactions throughout the entire experiment. The persistence of enhanced SSEP components throughout the habituation process may be caused by a deficit in reducing the activity of attention-related brain processes concerned with intrusive, yet behaviourally irrelevant, continued stimulation in the state of major depression.

Effects of the high-affinity corticotropin-releasing hormone receptor 1 antagonist R121919 in major depression: the first 20 patients treated

Clinical and preclinical data suggest that unrestrained secretion of corticoctropin-releasing hormone (CRH) in the CNS produces several signs and symptoms of depression and anxiety disorders through continuous activation of CRH(1) receptors. This led to the development of drugs that selectively antagonize CRH(1) receptors suppressing anxiety-like behavior in rats and also in monkey models of anxiety. These findings led to a clinical development program exploring the antidepressive potential of R121919, a water-soluble pyrrolopyrimidine that binds with high affinity to human CRH(1) receptors and is well absorbed in humans. This compound was administered to 24 patients with a major depressive episode primarily in order to investigate whether its endocrine mode of action compromises the stress-hormone system or whether other safety and tolerability issues exist. The patients were enrolled in two dose-escalation panels: one group (n=10) where the dose range increased from 5-40 mg and another group (n=10) where the dose escalated from 40 to 80 mg within 30 days each. Four patients dropped out because of withdrawal of consent to participate (three cases) or worsening of depressive symptomatoloy in one case. We found that R121919 was safe and well tolerated by the patients during the observation period. Moreover, the data suggested that CRH(1)-receptor blockade does not impair the corticotropin and cortisol secretory activity either at baseline or following an exogenous CRH challenge. We also observed significant reductions in depression and anxiety scores using both, patient and clinician ratings. These findings, along with the observed worsening of affective symptomatology after drug discontinuation, suggests that the pharmacological principle of CRH(1)-receptor antagonism has considerable therapeutic potential in the treatment and the prevention of diseases where exaggerated central CRH activity is present at baseline or following stress exposure.

[Dependency of non-benzodiazepine hypnotics. Two case reports]

With the introduction of the non-benzodiazepine hypnotics zopiclone and zolpidem it was expected to have hypnotics without side effects and risks characteristically seen with benzodiazepines. We report two cases with high-dose usage and dependency of non-benzodiazepine hypnotics. Both patients were prescribed the drugs to treat sleep disturbances occurring during a depressive episode. While one patient had a polysubstance abuse there was no evidence for an abuse history in the other patient. To reduce withdrawal symptoms long-acting benzodiazepines were given to both patients. Thus, it seems that not only patients with a history of substance abuse but also patients with a psychiatric disorder are at risk for abuse of non-benzodiazepine hypnotics. Considering the increasing number of case reports with abuse and dependence of zopiclone and zolpidem it seems necessary to reevaluate the dependency risk of the currently available non-benzodiazepine hypnotics.

[Determinations of MAG3 clearance according to the whole-body principle and to related methods]

To answer the question for the most effective use of all usually available information, the MAG3 clearance was determined by different methods: firstly in an optimated whole-body technique for reference, further for comparison by means of a camera background-curve and a dedicated evaluating procedure, and in addition according to the compartmental principle (Sapirstein), by the latter method also simultaneously together with the hippurate clearance. Two simplified methods were applied as well, a non-invasive one and a single-sample method. The results revealed the relatively unpretentious camera technique to be nearly equivalent to more expensive procedures, but qualitatively superior to those methods, which are unnecessarily oversimplified.

Trimipramine and imipramine exert different effects on the sleep EEG and on nocturnal hormone secretion during treatment of major depression

In a 4-week double-blind clinical trial we compared the effects of the tricyclic antidepressants trimipramine and imipramine on the sleep EEG and on nocturnal bormone secretion in 20 male inpatients with major depression. Both treatments produced rapid significant clinical improvement in depression without severe adverse effects. However, the two drugs had markedly different neurobiologic profiles. Trimipramine enhanced rapid eye movement (REM) sleep and slow wave sleep, whereas imipramine suppressed REM sleep and showed no effect on slow wave sleep. Total sleep time and the sleep efficiency index increased under trimipramine but not under imipramine. Nocturnal cortisol secretion decreased with trimipramine but remained unchanged with imipramine. In contrast to imipramine, trimipramine induced an increase in prolactin secretion compatible with its known antagonism at dopamine (D2) receptors. Imipramine induced a decrease in growth hormone secretion during the first half of the night. Neither of the drugs induced significant changes in plasma testosterone concentration. We conclude that trimipramine is an antidepressant with sleep-improving qualities that possibly acts through inhibition of hypothalamic-pituitary-adrenocortical system activity by a yet unknown mechanism.

Bestimmung der MAG3-Clearance nach dem Ganzkörperprinzip und nach verwandten Methoden

Zur Klärung der Frage, wie die gesamte im Regelfall vorhandene Information optimal genutzt werden kann, wurde die MAG3-Clearance nach verschiedenen Methoden bestimmt: zum ersten als Referenz in optimierter Ganzkörpertechnik, weiter zum Vergleich mittels Kamera-Untergrundkurve und eigens dafür entwickeltem Auswerteverfahren, außerdem nach dem Kompartimentprinzip (Sapirstein), dabei auch simultan mit der Hippuranclearance. Schließlich kamen noch zwei vereinfachte Methoden zur Anwendung, eine »unblutige« und eine Single-Sample-Methode. Das keine besonderen Anforderungen stellende Kameraverfahren erwies sich dabei den aufwendigeren Methoden gegenüber als nahezu gleichwertig, den unnötig stark vereinfachten Verfahren gegenüber aber als qualitativ überlegen.

Protective effect of taurine on hypoxia and reoxygenation-induced damage of human colon cells (HT 29)

In this experimental model, taurine administered during hypoxia markedly reduced the cell damage due to O2 deficiency, and the beneficial effect outlasted the period of reoxygenation. The mechanisms for the improved survival rates are postulated to be a reduced osmoregulatory disturbance of cellular integrity, improved Ca2+ homeostasis and induction of accelerated cellular growth processes. In our simplified cell culture model the UW solution seems to be the most appropriate solution for the cold (hypoxic) preservation of human colon cells. We conclude, that within this experimental model and under these experimental conditions, taurine supplementation of the conventionally used preservation solutions improved the solutions markedly. Considering our previous studies, taurine seems to be a potent endogenous protective agent against cellular deterioration due to hypoxia and reoxygenation.

Growth hormone-releasing hormone (GHRH)-induced effects on sleep EEG and nocturnal secretion of growth hormone, cortisol and ACTH in patients with major depression

Studies in normal human subjects and animals suggest that the neuropeptide growth hormone-releasing hormone (GHRH) is a common regulator of the sleep EEG and nocturnal hormone secretion. In healthy volunteers GHRH prompts an increase in the amount of slow wave sleep (SWS) and in growth hormone (GH) secretion and blunting of cortisol release. Inhibition of GHRH may contribute to sleep-endocrine aberrances during depression. We tested the effects of pulsatile application of 4 x 50 micrograms GHRH on the sleep EEG and simultaneously investigated nocturnal hormone secretion in 10 inpatients (four females, six males) with the acute episode of major depression. In contrast to the effects of placebo, GH secretion increased distinctly and rapid-eye-movement (REM) density decreased during the second half of night. No other significant changes in sleep-endocrine activity, including SWS, cortisol and ACTH secretion, could be observed. We assume that hypothalamic-pituitary-adrenocortical system activity and slow wave sleep are inert to the influence of GHRH during acute depression. Cortisol and ACTH remained unchanged even in a subsample of five younger (aged 19-28 years) patients. This observation is in contrast to our recent finding that cortisol secretion is blunted in young normal volunteers after GHRH. But on the other hand, GHRH is capable of stimulating GH and inducing a decrease in REM density in these subjects.

Correlates of cognitive impairment and depressive mood disorder in multiple sclerosis

The psychopathological status of 25 inpatients suffering from clinically definite multiple sclerosis (MS) according to Poser criteria was assessed by using standardized methods (Structured Clinical Interview for DSM-III-R, Inpatient Multidimensional Psychiatric Scale, Hamilton and Montgomery-Asberg Depression Rating Scales and the Structured Interview for the Diagnosis of Alzheimer Dementia and Dementias of other Aetiology (SIDAM). Magnetic resonance (MRT) (0.5 T; T2-weighted sequence) of the brain was analysed by measuring the ventricular brain ration (VBR), the area of the corpus callosum (CC) and the extension of hyperintense lesions of the brainstem, the temporal lobes and the brain at all. Six of 25 (24%) of these moderately disabled patients (mean Extended Disability Score (EDSS) 3.3) were diagnosed to suffer from depressive mood disorder (major depression or dysthymia); 2 were demented. In correlation analysis, depression was unrelated to age, gender, duration of illness, status of disability (EDSS) or the results of cognitive assessment. No relationship between the depression scores and the different MRT measures could be identified. The presence or absence of gadolinium enhancement was also uncorrelated to depressive symptoms. Fatigue as measured by the Fatigue Severity Scale was unrelated to depression or subcortical brain atrophy (increased VBR) but significantly correlated to the area of hyperintense MRT changes in brainstem and midbrain. Cognitive impairment (decreased SIDAM scores) was correlated to the total area of hyperintense MRT changes of the brain parenchyma. The type of clinical course (relapsing-remitting vs chronic progredient) was not found to influence the affective or cognitive state in our MS patient's sample.

Subtypes of panic attacks and ICD-9 classification

No single ICD-9 category corresponds to panic disorder (DSM-III). To investigate whether patients with panic attacks can be identified by means of ICD-9, 97 patients with three panic attacks within 3 weeks were recruited from various medical centers, and were classified independently according to DSM-III and ICD-9. The ICD-9 diagnoses were scattered over a broad range of categories, and it was impossible to identify patients with panic disorder in this manner. Anxiety state, affective psychosis, and depressive neurosis were the most frequent ICD-9 diagnoses. The boundary between affective psychosis on the one hand and anxiety state and depressive neurosis on the other hand was validated by present and previous symptomatology and by cluster analysis. The boundary between anxiety state and depressive neurosis could not be validated in this way. Correspondingly, modifications of the ICD-9 classifications are proposed.

[Comparison of simple nuclear medical methods of determining renal clearance]

Comparative clearance determinations with a partially shielded whole-body counter, a shoulder probe, a gamma camera and also exclusively by use of the plasma activity concentration at 45 min p.i. revealed the following results: The partially shielded whole-body counter can be substituted by the shoulder probe without major loss of quality, provided that this is taken into consideration in the subsequent calculations. However, values below 250 ml/min may possibly be wrong, i.e. too high, when the camera background-curve is used for clearance determination. The very simple 45-min-clearance is recommended mostly as a method in addition or in reserve.

Einfache nuklearmedizinische Nierenclearancemethoden im Vergleich

Vergleichende Clearancebestimmungen mit Ganzkörpermeßstand, Schultersonde, Gammakamera sowie auch allein mit Hilfe der Plasmaaktivitätskonzentration 45 min p.i. brachten folgende Ergebnisse: Der Ganzkörpermeßstand läßt sich ohne größere Qualitätseinbußen durch eine Schultersonde ersetzen, wenn dies bei der weiteren Auswertung in geeigneter Weise berücksichtigt wird. Hingegen können bei der Clearancebestimmung mittels Kamerauntergrundkurve schon Werte unterhalb von 250 ml/min unter Umständen eindeutig falsch, d.h. zu hoch, sein. Die sehr einfache 45-min-Clearance empfiehlt sich vor allem als Zusatz- oder Reservemethode.

[Determination of kidney clearance by reconstruction of the whole-body retention curves from later measurements]

Starting from routine renal clearance measurements in a partially shielded whole-body counter, generally applicable algorithms were developed empirically which permit the reconstruction of the total course of retention up to 28 min p.i. from e.g. the 12 min and 24 min values only. By formal differentiation the instantaneous slope of the decline in retention and thus the renal clearance can be calculated employing the whole-body counting principle. Integration yields the possibility of subtracting background from renograms to calculate single renal clearances. The method offers advantages in cases of reduced measurement geometry and/or low count rates.

Bestimmung der Nierenclearance durch Rekonstruktion der Ganzkörperretentionskurve aus späteren Meßwerten

Ausgehend von routinemäßigen Nierenclearancebestimmungen am teilabgeschirmten Ganzkörpermeßstand, wurden auf empirischem Wege allgemeingültige Algorithmen entwickelt, mit denen der gesamte Retentionsverlauf bis über 28 min p.i. beispielsweise lediglich aus dem 12-min- und dem 24-min-Wert rekonstruiert werden kann. Durch formale Differentiation läßt sich hieraus die momentane Steigung des Retentionsgefälles und damit auch die Nierenclearance nach dem Ganzkörperprinzip bestimmen. Durch Integration ergeben sich Möglichkeiten zur Untergrundsubtraktion der Nephrogramme für die Berechnung der seitengetrennten Clearance. Das Verfahren bietet vor allem Vorteile bei reduzierter Meßgeometrie und/oder bei niedrigen Zählraten.