Direct Oral Anticoagulants (DOACs) for Therapeutic Targeting of Thrombin, a Key Mediator of Cerebrovascular and Neuronal Dysfunction in Alzheimer's Disease.

Although preclinical research and observer studies on patients with atrial fibrillation concluded that direct oral anticoagulants (DOACs) can protect against dementia like Alzheimer's disease (AD), clinical investigation towards therapeutical approval is still pending. DOACs target pathological thrombin, which is, like toxic tau and amyloid-ß proteins (Aß), an early hallmark of AD. Especially in hippocampal and neocortical areas, the release of parenchymal Aß into the blood induces thrombin and proinflammatory bradykinin synthesis by activating factor XII of the contact system. Thrombin promotes platelet aggregation and catalyzes conversion of fibrinogen to fibrin, leading to degradation-resistant, Aß-containing fibrin clots. Together with oligomeric Aß, these clots trigger vessel constriction and cerebral amyloid angiopathy (CAA) with vessel occlusion and hemorrhages, leading to vascular and blood-brain barrier (BBB) dysfunction. As consequences, brain blood flow, perfusion, and supply with oxygen (hypoxia) and nutrients decrease. In parenchymal tissue, hypoxia stimulates Aß synthesis, leading to Aß accumulation, which is further enhanced by BBB-impaired perivascular Aß clearance. Aß trigger neuronal damage and promote tau pathologies. BBB dysfunction enables thrombin and fibrin(ogen) to migrate into parenchymal tissue and to activate glial cells. Inflammation and continued Aß production are the results. Synapses and neurons die, and cognitive abilities are lost. DOACs block thrombin by inhibiting its activity (dabigatran) or production (FXa-inhibitors, e.g., apixaban, rivaroxaban). Therefore, DOAC use could preserve vascular integrity and brain perfusion and, thereby, could counteract vascular-driven neuronal and cognitive decline in AD. A conception for clinical investigation is presented, focused on DOAC treatment of patients with diagnosed AD in early-stage and low risk of major bleeding.

Alzheimer's Disease-Rationales for Potential Treatment with the Thrombin Inhibitor Dabigatran.

Alzheimer's disease (AD) is caused by neurodegenerative, but also vascular and hemostatic changes in the brain. The oral thrombin inhibitor dabigatran, which has been used for over a decade in preventing thromboembolism and has a well-known pharmacokinetic, safety and antidote profile, can be an option to treat vascular dysfunction in early AD, a condition known as cerebral amyloid angiopathy (CAA). Recent results have revealed that amyloid-ß proteins (Aß), thrombin and fibrin play a crucial role in triggering vascular and parenchymal brain abnormalities in CAA. Dabigatran blocks soluble thrombin, thrombin-mediated formation of fibrin and Aß-containing fibrin clots. These clots are deposited in brain parenchyma and blood vessels in areas of CAA. Fibrin-Aß deposition causes microvascular constriction, occlusion and hemorrhage, leading to vascular and blood-brain barrier dysfunction. As a result, blood flow, perfusion and oxygen and nutrient supply are chronically reduced, mainly in hippocampal and neocortical brain areas. Dabigatran has the potential to preserve perfusion and oxygen delivery to the brain, and to prevent parenchymal Aß-, thrombin- and fibrin-triggered inflammatory and neurodegenerative processes, leading to synapse and neuron death, and cognitive decline. Beneficial effects of dabigatran on CAA and AD have recently been shown in preclinical studies and in retrospective observer studies on patients. Therefore, clinical studies are warranted, in order to possibly expand dabigatran approval for repositioning for AD treatment.

Universal and culturally specific aspects of sensitive responsiveness to young children.

Human newborn infants are evolutionarily predisposed to communicate. Caretakers may interpret their signals, more or less correctly, as meaningful and intentional. Reliable responsiveness is the essence of the attachment system; appropriate and prompt responses to instant's' signals support secure quality of attachment. Other signals, if sensitively responded to, support curiosity for the world. From birth onward infants experience and learn whether their signals will be answered, and in what way, by whom, and when, thereby developing into their own culture. Videos from seven cultures, presented here, demonstrate the ubiquity of maternal responsiveness. They present a solid basis for future data from cultural and from biological anthropology. Carefully videotaped observations elucidate differences in meaning and function of sensitive caregiver-infant interactions for the emotional and cultural development of children in various cultures.

Anticoagulants for Treatment of Alzheimer's Disease.

Alzheimer's disease (AD) is a multifactorial syndrome with a plethora of progressive, degenerative changes in the brain parenchyma, but also in the cerebrovascular and hemostatic system. A therapeutic approach for AD is reviewed, which is focused on the role of amyloid-ß protein (Aß) and fibrin in triggering intra-brain vascular dysfunction and connected, cognitive decline. It is proposed that direct oral anticoagulants (DOACs) counteract Aß-induced pathological alterations in cerebral blood vessels early in AD, a condition, known as cerebral amyloid angiopathy (CAA). By inhibiting thrombin for fibrin formation, anticoagulants can prevent accumulations of proinflammatory thrombin and fibrin, and deposition of degradation-resistant, Aß-containing fibrin clots. These fibrin-Aß clots are found in brain parenchyma between neuron cells, and in and around cerebral blood vessels in areas of CAA, leading to decreased cerebral blood flow. Consequently, anticoagulant treatment could reduce hypoperfusion and restricted supply of brain tissue with oxygen and nutrients. Concomitantly, hypoperfusion-enhanced neurodegenerative processes, such as progressive Aß accumulation via synthesis and reduced perivascular clearance, neuroinflammation, and synapse and neuron cell loss, could be mitigated. Given full cerebral perfusion and reduced Aß- and fibrin-accumulating and inflammatory milieu, anticoagulants could be able to decrease vascular-driven progression in neurodegenerative and cognitive changes, present in AD, when treated early, therapeutically, or prophylactically.

Essentials when studying child-father attachment: A fundamental view on safe haven and secure base phenomena.

The most relevant functions of an attachment figure for a child from evolutionary, cultural, and individual perspectives are being a safe haven and secure base for the child. The concepts of behavioral systems and emotional security are delineated. Central to a child's emotional security is her smooth transition between seeking a safe haven when distressed and a secure base when at ease with her attachment figures. The special quality of the child-father attachment relationship is marked by an emphasis on supporting the child's exploration and her emotional intensity during agitated play. Systematic analysis of child-father attachment requires careful, realistic, and lengthy natural, ethological observations of behaviors that indicate the child's attachment to father. Such observations would result in a fuller understanding of the infants' or children's contribution to their development of psychological security.

Universal and culturally specific aspects of sensitive responsiveness to young children.

This article describes the earliest processes involved in socializing infants into cultural beings, that are thought to set the stage for the type of interactions described in this special issue. From birth onwards, infants experience and learn whether their signals will be answered, and in what way, by whom, and when. Infants learn about their own culture from the persons around them through the meaning and interpretations these persons give to their behaviors. Many questions remain about how these processes link to infant brain development, and how insights from cultural and biological anthropology can be used to elucidate the meaning and function of sensitive caregiver-infant interactions.

Inhibition of saturated very-long-chain fatty acid biosynthesis by mefluidide and perfluidone, selective inhibitors of 3-ketoacyl-CoA synthases.

The trifluoromethanesulphonanilides mefluidide and perfluidone are used in agriculture as plant growth regulators and herbicides. Despite the fact that mefluidide and perfluidone have been investigated experimentally for decades, their mode of action is still unknown. In this study, we used a cascade approach of different methods to clarify the mode of action and target site of mefluidide and perfluidone. Physiological profiling using an array of biotests and metabolic profiling in treated plants of Lemna paucicostata suggested a common mode of action in very-long-chain fatty acid (VLCFA) synthesis similar to the known 3-ketoacyl-CoA synthase (KCS) inhibitor metazachlor. Detailed analysis of fatty acid composition in Lemna plants showed a decrease of saturated VLCFAs after treatment with mefluidide and perfluidone. To study compound effects on enzyme level, recombinant KCSs from Arabidopsis thaliana were expressed in Saccharomyces cerevisiae. Enzyme activities of seven KCS proteins from 17 tested were characterized by their fatty acid substrate and product spectrum. For the KCS CER6, the VLCFA product spectrum in vivo, which consists of tetracosanoic acid, hexacosanoic acid and octacosanoic acid, is reported here for the first time. Similar to metazachlor, mefluidide and perfluidone were able to inhibit KCS1, CER6 and CER60 enzyme activities in vivo. FAE1 and KCS2 were inhibited by mefluidide only slightly, whereas metazachlor and perfluidone were strong inhibitors of these enzymes with IC(50) values in µM range. This suggests that KCS enzymes in VLCFA synthesis are the primary herbicide target of mefluidide and perfluidone.

On the mode of action of the herbicides cinmethylin and 5-benzyloxymethyl-1, 2-isoxazolines: putative inhibitors of plant tyrosine aminotransferase.

BACKGROUND: The mode of action of the grass herbicides cinmethylin and 5-benzyloxymethyl-1,2-isoxazolines substituted with methylthiophene (methiozolin) or pyridine (ISO1, ISO2) was investigated. RESULTS: Physiological profiling using a series of biotests and metabolic profiling in treated duckweed (Lemna paucicostata L.) suggested a common mode of action for the herbicides. Symptoms of growth inhibition and photobleaching of new fronds in Lemna were accompanied with metabolite changes indicating an upregulation of shikimate and tyrosine metabolism, paralleled by decreased plastoquinone and carotenoid synthesis. Supplying Lemna with 10 µM of 4-hydroxyphenylpyruvate (4-HPP) reversed phytotoxic effects of cinmethylin and isoxazolines to a great extent, whereas the addition of L-tyrosine was ineffective. It was hypothesised that the herbicides block the conversion of tyrosine to 4-HPP, catalysed by tyrosine aminotransferase (TAT), in the prenylquinone pathway which provides plastoquinone, a cofactor of phytoene desaturase in carotenoid synthesis. Accordingly, enhanced resistance to ISO1 treatment was observed in Arabidopsis thaliana L. mutants, which overexpress the yeast prephenate dehydrogenase in plastids as a TAT bypass. In addition, the herbicides were able to inhibit TAT7 activity in vitro for the recombinant enzyme of A. thaliana. CONCLUSION: The results suggest that TAT7 or another TAT isoenzyme is the putative target of the herbicides.

Physionomics and metabolomics-two key approaches in herbicidal mode of action discovery.

BACKGROUND: For novel herbicides identified in greenhouse screens, efficient research is important to discover and chemically optimise new leads with new modes of action (MoAs). RESULTS: The metabolic and physiological response pattern to a herbicide can be viewed as the result of changes elicited in the molecular and biochemical process chain. These response patterns are diagnostic of a herbicide's MoA. At the starting point of MoA characterisation, an array of bioassays is used for comprehensive physiological profiling of herbicide effects. This physionomics approach enables discrimination between known, novel or multiple MoAs of a compound and provides a first clue to a new MoA. Metabolic profiling is performed with the use of treated Lemna paucicostata plants. After plant extraction and chromatography and mass spectrometry, changes in levels of approximately 200 identified and 300 unknown analytes are quantified. Check for known MoA assignment is performed by multivariate statistical data analyses. Distinct metabolite changes, which can direct to an affected enzymatic step, are visualised in a biochemical pathway view. Subsequent target identification includes metabolite feeding and molecular, biochemical and microscopic methods. CONCLUSION: The value of this cascade strategy is exemplified by new herbicides with MoAs in plastoquinone, auxin or very-long-chain fatty acid synthesis.

Auxin herbicides: current status of mechanism and mode of action.

Synthetic compounds that act like phytohormonal 'superauxins' have been among the most successful herbicides used in agriculture for more than 60 years. These so-called auxin herbicides are more stable in planta than the main natural auxin, indole-3-acetic acid (IAA), and show systemic mobility and selective action, preferentially against dicot weeds in cereal crops. They belong to different chemical classes, which include phenoxycarboxylic acids, benzoic acids, pyridinecarboxylic acids, aromatic carboxymethyl derivatives and quinolinecarboxylic acids. The recent identification of receptors for auxin perception and the discovery of a new hormone interaction in signalling between auxin, ethylene and the upregulation of abscisic acid biosynthesis account for a large part of the repertoire of auxin-herbicide-mediated responses, which include growth inhibition, senescence and tissue decay in sensitive dicots. An additional phenomenon is caused by the quinolinecarboxylic acid quinclorac, which also controls grass weeds. Here, the accumulation of phytotoxic levels of tissue cyanide, derived ultimately from quinclorac-stimulated ethylene biosynthesis, plays a key role in eliciting the herbicidal symptoms in sensitive grasses.

The herbicide flamprop-M-methyl has a new antimicrotubule mechanism of action.

BACKGROUND: The herbicidal mode of action of flamprop-M-methyl [methyl N-benzoyl-N-(3-chloro-4-fluorophenyl)-D-alaninate] was investigated. RESULTS: For initial characterization, a series of bioassays was used, which indicated a mode of action similar to that of mitotic disrupter herbicides. Cytochemical fluorescence studies, which included monoclonal antibodies against polymerized tubulin, were applied to elucidate effects on mitosis and microtubule assembly in maize roots. When seedlings were root treated with 50 microM of flamprop-M-methyl, cell division activity in meristematic root tip cells ceased within 4 h. The compound severely disturbed the orientation of spindle and phragmoblast microtubules, leading to defective spindle and phragmoblast structures. Cortical microtubules were only slightly affected. In late anaphase and early telophase cells, phragmoblast microtubules were disorganized in multiple arrays that hampered regular cell plate deposition in cytokinesis. Microtubules of the spindle apparatus were found attached to chromosomal kinetochores, but did not show regular organization associated with a zone of microtubule-organizing centres at the opposite ends of the cell. On account of this loss of spindle organization, chromosomes remained in a condensed state of prometaphase or metaphase. Unlike known microtubule disrupter herbicides, flamprop-M-methyl and its biologically active metabolite flamprop did not inhibit soybean tubulin polymerization to microtubules in vitro at 50 microM. In contrast, soybean plants responded sensitively to the compounds. CONCLUSION: The results indicate that flamprop-M-methyl is a mitotic disrupter herbicide with a new antimicrotubule mechanism of action that affects orientation of spindle and phragmoblast microtubules, possibly by minus-end microtubule disassembly.

On the mechanism of action and selectivity of the corn herbicide topramezone: a new inhibitor of 4-hydroxyphenylpyruvate dioxygenase.

Topramezone is a new, highly selective herbicide of pyrazole structure for the post-emergence control of broadleaf and grass weeds in corn. The biokinetic properties and mode of action of topramezone were investigated in plants of Setaria faberi Herrm, Sorghum bicolor (L.) Moench, Solanum nigrum L. and the crop species corn (Zea mays L.). Within 2-5 days after treatment, topramezone caused strong photobleaching effects on the shoot, followed by plant death of sensitive weeds. The selectivity of topramezone between corn and the weed species has been quantified as above 1000-fold. By virtue of the plant symptoms and the reversal of the effects in Lemna paucicostata L. by adding homogentisate, it was hypothesized that topramezone blocks the formation of homogentisate, possibly through inhibition of 4-hydroxyphenylpyruvate dioxygenase (4-HPPD). Indeed, topramezone strongly inhibited 4-HPPD activity in vitro, with I(50) values of 15 and 23 nM for the enzyme isolated from S. faberi and recombinant enzyme of Arabidopsis thaliana L. respectively. The enzyme activity from corn was approximately 10 times less sensitive. After root and foliar application of [(14)C]topramezone, equivalent to field rates of 75 g ha(-1), the herbicide was rapidly absorbed and systemically translocated in the plant. Only marginal differences between leaf uptake and translocation of topramezone by the weeds and corn were found. Metabolism of foliar-applied [(14)C]topramezone was far more rapid in corn than in the weeds. A more rapid metabolism combined with a lower sensitivity of the 4-HPPD target enzyme contributes to the tolerance of corn to topramezone.

[The development of psychological security in attachment--results and conclusions for therapy]. / Die Entwicklung psychischer Sicherheit in Bindungen - Ergebnisse und Folgerungen für die Therapie.

Attachment is a biological propensity of primate infants to form close protective relationships with their mothers. In humans it is the special relationship in which the organization of emotions, empathy and knowledge about oneself and others is combined and represented in inner working models. For this, it is innate to human nature to form joint attention structures in which language develops for learning individual and particularly emotional and cultural meanings by narrative interpretations of various experiences. These processes are essential for the development of human beings. Joint attention is initially and primarily formed between infants and attachment persons. Fathers in particular can be additional supportive attachment persons, as well as teachers, grandmothers etc. Sensitivity to infants' attachment needs is the key to understanding the development of secure or insecure attachment strategies. These strategies highly influence the development of psychological security in mature and adaptive, or psychological insecurity in less mature and less flexibly adapted adolescents and adults.

Indole-3-acetic acid and auxin herbicides up-regulate 9-cis-epoxycarotenoid dioxygenase gene expression and abscisic acid accumulation in cleavers (Galium aparine): interaction with ethylene.

Interaction between auxin and auxin-induced ethylene was suggested in previous work to up-regulate abscisic acid (ABA) biosynthesis in cleavers (Galium aparine) through stimulated cleavage of xanthophylls to xanthoxin, catalysed by 9-cis-epoxycarotenoid dioxygenase (NCED). Here, the effects of auxin on NCED gene expression were studied in relation to changes in ethylene synthesis and ABA levels. A gene from G. aparine shoot tissue was cloned based on sequence similarity to cloned NCED genes from tomato (LeNCED1), potato, Phaseolus, and Arabidopsis. When the roots of G. aparine plants were treated with 0.5 mM indole-3-acetic acid (IAA), IAA concentrations increased from 0.2 microM to 65 microM IAA in the shoot tissue after 3 h. Transient increases in GaNCED1 mRNA levels were detectable as early as 1 h after treatment and reached maximum values of 40-fold, relative to the control, after 3 h. Increases in GaNCED1 mRNA preceded increases in 1-aminocyclopropane-1-carboxylic acid and ethylene. Levels of ABA began to increase more slowly and, significantly, with a lag phase of 2 h, and reached levels 24-fold higher than those in controls after 24 h. GaNCED1 gene expression was also stimulated by auxin herbicides. The ethylene-releasing compound ethephon induced GaNCED1 transcript levels only moderately. In accordance with this, aminoethoxyvinylglycine and cobalt ions, which inhibit ethylene synthesis, only slightly affected the increase in GaNCED1 transcript levels by IAA. However, both ethylene inhibitors decreased IAA-induced ABA accumulation by up to 70%. This suggests that auxin and auxin-induced ethylene are involved in ABA accumulation. While auxin is the primary trigger for NCED gene expression, ethylene appears to enhance ABA biosynthesis, possibly by up-regulation of NCED activity post-transcriptionally.

Auxin herbicide action: lifting the veil step by step.

Over decades, the so-called growth regulator or auxin herbicides had resisted all efforts to elucidate their molecular interactions and the biochemical and physiological basis of their phytotoxicity.1-3 The identification and crystal structure analysis of receptors for auxin perception4-8 and the discovery of a new hormone interaction in signalling between auxin, ethylene and the up-regulation of 9-cis-epoxycarotenoid dioxygenase (NCED) in abscisic acid (ABA) biosynthesis,9 leading to ABA accumulation,3 are long steps towards understanding of auxin herbicide action in dicot plants.

Metrafenone: studies on the mode of action of a novel cereal powdery mildew fungicide.

Powdery mildew fungi are among the major pathogens causing diseases of cereals in the world. The mode of action of a novel systemic benzophenone fungicide, metrafenone, which is based on a precursor that is discussed in the preceding paper, has been analysed on the powdery mildew fungi of barley (Blumeria graminis Speer f. sp. hordei Marchal) and wheat (Blumeria graminis Speer f. sp. tritici Marchal). Preventive treatments reduced germination and blocked development beyond formation of appressoria, which penetrated less often. Moreover, metrafenone turned out to be an efficient curative fungicide, which rapidly affected fungal survival at low concentrations. The fungicide induced swelling, bursting and collapse of hyphal tips, resulting in the release of globules of cytoplasm. Bifurcation of hyphal tips, secondary appressoria and hyperbranching were also frequently observed. A histochemical analysis showed that metrafenone caused disruption of the apical actin cap and apical vesicle transport as well as weakening of the cell wall at hyphal tips. Finally, metrafenone strongly reduced sporulation. Reduced sporulation was associated with malformation of conidiophores that showed irregular septation, multinucleate cells and delocalisation of actin. Microtubules appeared to be only secondarily affected in metrafenone-treated B. graminis. The results suggest that the mode of action of metrafenone interferes with hyphal morphogenesis, polarised hyphal growth and the establishment and maintenance of cell polarity. Metrafenone likely disturbs a pathway regulating organisation of the actin cytoskeleton.

Herbicidal cyanoacrylates with antimicrotubule mechanism of action.

The herbicidal mode of action of the new synthetic cyanoacrylates ethyl (2Z)-3-amino-2-cyano-4-ethylhex-2-enoate (CA1) and its isopropyl ester derivative CA2 was investigated. For initial characterization, a series of bioassays was used indicating a mode of action similar to that of mitotic disrupter herbicides such as the dinitroaniline pendimethalin. Cytochemical fluorescence studies including monoclonal antibodies against polymerized and depolymerized tubulin and a cellulose-binding domain of a bacterial cellulase conjugated to a fluorescent dye were applied to elucidate effects on cell division processes including mitosis and microtubule and cell wall formation in maize roots. When seedlings were root treated with 10 microM of CA1 or CA2, cell division activity in meristematic root tip cells decreased within 4 h. The chromosomes proceeded to a condensed state of prometaphase, but were unable to progress further in the mitotic cycle. The compounds caused a complete loss of microtubular structures, including preprophase, spindle, phragmoplast and cortical microtubules. Concomitantly, in the cytoplasm, an increase in labelling of free tubulin was observed. This suggests that the herbicides disrupt polymerization and microtubule stability, whereas tubulin synthesis or degradation appeared not to be affected. In addition, cellulose labelling in cell walls of root tip cells was not influenced. The effects of CA1 and CA2 were comparable with those caused by pendimethalin. In transgenic Arabidopsis plants expressing a green fluorescent protein-microtubule-associated protein4 fusion protein, labelled arrays of cortical microtubules in living epidermal cells of hypocotyls collapsed within 160 min after exposure to 10 microM CA1 or pendimethalin. Moreover, a dinitroaniline-resistant biotype of goosegrass (Eleusine indica (L) Gaertn) with a point mutation in alpha-tubulin showed cross-resistance against CA1 and CA2. The results strongly indicate that the cyanoacrylates are a new chemical class of herbicide which possess the same antimicrotubule mechanism of action as dinitroanilines, probably including interaction with the same binding site in alpha-tubulin.

Attachment state of mind and perceptual processing of emotional stimuli.

This study aimed to investigate the relationship between attachment state of mind and perceptual processing of social and non-social, affective, and neutral material. A total of 57 young adults completed the Adult Attachment Interview (AAI) plus an experimental task in which their perceptual thresholds to different types of pictures were assessed. Significant correlations were found between the AAI dimensions and perceptual thresholds for social stimuli such as social interactions or human faces displaying emotional expressions. As expected, no relationships were found between the AAI and perception of neutral stimuli. The pattern of correlations was especially clear for the dismissing dimension. The results suggest that higher vigilance to social stimuli is related to dismissing attachment tendencies and, to a milder degree, to preoccupied tendencies.