Induction of aggression and anxiety-like responses by perfluorooctanoic acid is accompanied by modulation of cholinergic- and purinergic signaling-related parameters in adult zebrafish.

Perfluorooctanoic acid (PFOA) is a contaminant of global concern owing to its prevalent occurrence in aquatic and terrestrial environments with potential hazardous impact on living organisms. Here, we investigated the influence of realistic environmental concentrations of PFOA (0, 0.25, 0.5, or 1.0 mg/L) on relevant behaviors of adult zebrafish (Danio rerio) (e.g., exploration to novelty, social preference, and aggression) and the possible role of PFOA in modulating cholinergic and purinergic signaling in the brain after exposure for 7 consecutive days. PFOA significantly increased geotaxis as well as reduced vertical exploration (a behavioral endpoint for anxiety), and increased the frequency and duration of aggressive episodes without affecting their social preference. Exposure to PFOA did not affect ADP hydrolysis, whereas ATP and AMP hydrolysis were significantly increased at the highest concentration tested. However, AChE activity was markedly decreased in all PFOA-exposed groups when compared with control. In conclusion, PFOA induces aggression and anxiety-like behavior in adult zebrafish and modulates both cholinergic and purinergic signaling biomarkers. These novel data can provide valuable insights into possible health threats related to human activities, demonstrating the utility of adult zebrafish to elucidate how PFOA affects neurobehavioral responses in aquatic organisms.

Taurine modulates behavioral effects of intermittent ethanol exposure without changing brain monoamine oxidase activity in zebrafish: Attenuation of shoal- and anxiety-like responses, and abolishment of memory acquisition deficit.

Prolonged alcohol consumption has been considered as an important risk factor for various diseases. Chronic ethanol (EtOH) intake is associated with deleterious effects on brain functions culminating in robust behavioral changes. Notably, drugs available to treat the effects of EtOH have low therapeutic efficacy so far. Taurine (TAU) appears as a promising neuroprotective molecule due to its pleiotropic action in the brain. Here, we investigated whether TAU plays a beneficial role in different behavioral domains of zebrafish submitted to an intermittent EtOH exposure model, specially focusing on social behavior, anxiety-like responses, and memory. Moreover, since monoamines play a role in EtOH-mediated responses, we also evaluated the influence of both TAU and EtOH exposures on brain monoamine oxidase (Z-MAO) activity. Fish were exposed to non-chlorinated water or 1% EtOH for 8 consecutive days (20 min per day). From the 5th day until the end of the experimental period (8th day), animals were kept in the absence or presence of TAU (42, 150, or 400 mg/L) 1 h per day immediately after EtOH exposure. Behavioral measurements started 24 h after the last EtOH exposure. We observed that TAU showed modest attenuating effects on shoaling behavior and anxiety-like responses, while 42 and 150 mg/L TAU abolished the memory acquisition deficit in the inhibitory avoidance task. Biochemical analysis revealed that TAU did not modulate EtOH-induced increase on brain Z-MAO activity. Collectively, our novel data show a potential beneficial effect of TAU in an intermittent EtOH exposure model in zebrafish. Moreover, these findings foster the growing utility of this aquatic species to investigate the neurobehavioral basis of EtOH- and TAU-mediated responses in vertebrates.

Acute effects of ethanol on behavioral responses of male and female zebrafish in the open field test with the influence of a non-familiar object.

In this report, we investigate whether the acute effects of different ethanol (EtOH) concentrations are sex-dependent in zebrafish subjected to the open field test (OFT) with the influence of a non-familiar object. Male and female zebrafish were separated into four groups and exposed to EtOH (0%, 0.25%, 0.5%, or 1.0% v/v) for 1 h. Fish were tested individually in the OFT and the tank was divided into three areas: periphery, intermediate, and center area. An object (black sphere; diameter: 1 cm) was placed in the center of the tank and behaviors were recorded for 5 min. At the baseline, females had a distinct exploratory activity and interaction pattern with the object, reflecting a more anxious and shyer behavior in relation to males. Females exposed to 0.5% EtOH performed more rapid investigation to the object than males, while 1.0% EtOH reduced locomotion in both sexes and increased immobility only in males. Principal component analyses revealed that anxiety-like behaviors, exploratory activity, and locomotion were the components that most accounted for total variances. Collectively, our novel findings show the existence of a sex-dependent effect in the zebrafish models acutely exposed to EtOH tested in the OFT with a non-familiar object.

Taurine prevents MK-801-induced shoal dispersion and altered cortisol responses in zebrafish.

Schizophrenia is a chronic neuropsychiatric disorder characterized by a shortened lifespan and significant impaired social and vocational functioning. Schizophrenic patients can present hypothalamic-pituitary-adrenal (HPA) axis dysfunctions and cortisol dysregulation, which play an important role on the etiology onset, exacerbation, and relapsing of symptoms. Based on its intrinsic neuroprotective properties, taurine is considered a promising substance with beneficial role on various brain disorders, including schizophrenia. Here, we evaluated the effects of taurine on shoaling behavior and whole-body cortisol levels in zebrafish treated with dizocilpine (MK-801), which elicits schizophrenia-like phenotypes in animal models. Briefly, zebrafish shoals (4 fish per shoal) were exposed to dechlorinated water or taurine (42, 150, or 400 mg/L) for 60 min. Then, saline (PBS, pH 7.4 or 2.0 mg/kg MK-801) were intraperitoneally injected and zebrafish behavior was recorded 15 min later. In general, MK-801 disrupted shoaling behavior and reduced whole-body cortisol levels in zebrafish. All taurine pretreatments prevented MK-801-induced increase in shoal area, while 400 mg/L taurine prevented the MK-801-induced alterations in neuroendocrine responses. Moreover, all taurine-pretreated groups showed increased geotaxis, supporting a modulatory role in the overall dispersion pattern of the shoal. Collectively, our novel findings show a potential protective effect of taurine on MK-801-induced shoal dispersion and altered neuroendocrine responses, fostering the use of zebrafish models to assess schizophrenia-like phenotypes.

Stress increases susceptibility to pentylenetetrazole-induced seizures in adult zebrafish.

Stress is the body's reaction to any change that requires adaptive responses. In various organisms, stress is a seizure-related comorbidity. Despite the exposure to stressors eliciting aversive behaviors in zebrafish, there are no data showing whether stress potentiates epileptic seizures in this species. Here, we investigated whether a previous exposure to an intense acute stressor positively modulates the susceptibility to seizures in pentylenetetrazole (PTZ)-challenged zebrafish. The conspecific alarm substance (CAS) was used to elicit aversive responses (3.5 mL/L for 5 min), observed by increased bottom dwelling and erratic movements. Then, fish were immediately exposed to 7.5 mM PTZ for 10 min to induce seizure-like behaviors. Stress increased the seizure intensity, the number of clonic-like seizure behaviors (score 4), as well as facilitated the occurrence of score 4 episodes by decreasing the latency in which fish reached the score 4. Moreover, fish with heightened anxiety showed increased susceptibility to PTZ, since positive correlations between anxiety- and seizure-like behaviors were found. Overall, since CAS also increased whole-body cortisol levels in zebrafish, our novel findings show a prominent response to PTZ-induced seizures in previously stressed zebrafish. Moreover, we reinforce the growing utility of zebrafish models to assess seizure-related comorbidities aiming to elucidate how stress can affect epileptic seizures in vertebrates.

Taurine-mediated aggression is abolished via 5-HT1A antagonism and serotonin depletion in zebrafish.

Taurine is one of the most abundant amino acids in vertebrates involved in important physiological functions, including osmoregulation, membrane stability, and neuronal activity. The pleiotropic effects of taurine support the existence of different mechanisms of action (e.g., modulation of GABAA, strychnine-sensitive glycine, and NMDA receptors), which can play a role in aggressive-related responses. However, the mechanisms underlying the effects of taurine on aggression are still poorly understood. Because aggression has been associated with diverse central mechanisms, especially serotonergic activity, we aimed to investigate the involvement of this system in taurine-induced aggression in zebrafish. We treated adult zebrafish with ρ-chlorophenylalanine (ρCPA), an inhibitor of the serotonin synthesis, as well as 5-HT1A receptor antagonist and agonist (WAY100135 and buspirone, respectively). Taurine effects were tested individually at three concentrations (42, 150, and 400 mg/L) for 60 min. We further analyzed the effects on aggression and locomotion using the mirror-induced aggression test. Taurine concentration that changed behavioral responses was selected to the succeeding pharmacological experiments using ρCPA, WAY100135, and buspirone. We found that buspirone did not alter the aggression. Yet, 42 mg/L taurine increased aggression, which was abolished by ρCPA and WAY100135, indicating the involvement of 5-HT1A receptors in taurine-mediated aggression. These set of data support an indirect mechanism mediating taurine-induced aggression via serotonin release and activation of 5-HT1A receptors in zebrafish. While the exact mechanisms underlying aggression are still unclear, our novel findings reveal a key role of the serotonergic system in the effects of taurine, supporting the use of zebrafish models to understand the neural basis of aggression in vertebrates.

Perinatal management of trisomy 18: a survey of obstetricians in Australia, New Zealand and the UK.

OBJECTIVE: The objective of this study was to explore the attitudes of obstetricians in Australia, New Zealand and the UK towards prenatally diagnosed trisomy 18 (T18). METHOD: Obstetricians were contacted by email and invited to participate in an anonymous electronic survey. RESULTS: Survey responses were obtained from 1018/3717 (27%) practicing obstetricians/gynaecologists. Most (60%) had managed a case of T18 in the last 2 years. Eighty-five per cent believed that T18 was a 'lethal malformation', although 38% expected at least half of liveborn infants to survive for more than 1 week. Twenty-one per cent indicated that a vegetative existence was the best developmental outcome for surviving children. In a case of antenatally diagnosed T18, 95% of obstetricians would provide a mother with the option of termination. If requested, 99% would provide maternal-focused obstetric care (aimed at maternal wellbeing rather than fetal survival), whereas 80% would provide fetal-oriented obstetric care (to maximise fetal survival). Twenty-eight per cent would never discuss the option of caesarean; 21% would always discuss this option. Management options, attitudes and knowledge of T18 were associated with location, practice type, gender and religion of obstetricians. CONCLUSION: There is variability in obstetricians' attitudes towards T18, with significant implications for management of affected pregnancies.

Fatally flawed? A review and ethical analysis of lethal congenital malformations.

Prenatally diagnosed abnormalities that are associated with death in the newborn period are often referred to as 'lethal malformations'. Yet, for many of the commonly described lethal malformations long-term survival is possible if supportive interventions are provided. In this paper we analyse and review fetal or congenital lethal abnormalities. The designation 'lethal' overlaps with the concept of 'medical futility'. The term is used for a heterogenous group of conditions, and hinders clear communication and counselling. We argue that the term should be avoided, and propose in its place a set of key questions that should be addressed by counselling.

Signal transduction of erythropoietin in endothelial cells.

Erythropoietin (EPO) induces endothelin expression in endothelial cells (EC) and has angiogenic effects. We investigated the intracellular signal transduction of EPO in EC and tested the hypothesis that the proliferative effects of EPO may be mediated by cytosolic calcium, changes in intracellular pH, or tyrosine phosphorylation. Cytosolic calcium and pH were measured with fura-2 and BCECF. Protein phosphorylation was assessed with 32P-labeled EC and two-dimensional (2D) gel chromatography. Tyrosine phosphorylation was measured using specific antityrosine antibodies and confocal microscopy. Proliferation was measured by thymidine incorporation and cell count. No effects of EPO on cytosolic calcium and pH were observed. In contrast, erythropoietin increased phosphorylation of 94, 70, 42, 40, 29 and 25 kDa proteins at five minutes and 60 minutes. Most of the early proteins were tyrosine phosphorylated. Confocal microscopy showed cytosolic as well as membrane-bound tyrosine phosphorylation in resting cells and an EPO-induced translocation of immunoreactivity to the nucleus. Immunostaining for the transcription factor STAT-5 showed that EPO induced a nuclear translocation of STAT-5. EPO 0.5, 2, and 4 U/ml increased proliferation, an effect that was prevented by incubation with the tyrosine kinase inhibitor genistein. We conclude that EPO induces proliferation in EC initially via tyrosine phosphorylation of six distinct proteins, and that the phosphorylation and nuclear translocation of the transcription factor STAT-5 is important for the effects of EPO on EC.

[Expert assessment of chronic venous insufficiency]. / Die Begutachtung der chronisch-venösen Insuffizienz.

In the expertise of a chronic venous insufficiency kind and stage of the venous disease must be proved as objectively as possible. The diagnostic demands in the individual step programmes serve for the exact assessment of the remaining part of efficiency. The criteria of valuation are summarized, in which case we also deal with several possibilities of combination with other vascular diseases. The expert opinion of an accident is discussed. References to the inability to work, rating of nursing money, increased material benefit in impairments of health and to the acknowledgement of an identity card for injured persons supplement the statements.

[Current therapy of chronic arterial occlusive diseases of the lower extremities]. / Aktuelle Therapie chronischer arterieller Verschlusskrankheiten der unteren Extremitäten.

Angiologists, vascular surgeons, and angiographers inform about the actual state of the therapy of the arterial occlusive diseases of the legs. The degree I of therapy comprises the conservative treatment for the improvement of the macrocirculation and the normalisation of the disturbed microcirculation, taking into particular consideration the therapy with antiviscositant drugs. The main chapter ends with the possibilities of the influence on the arteriosclerotic vascular processes as well as with the necessary rehabilitative measures. In the paragraph about the degree II of therapy the indications, contraindications, methods and results of the isolated and combined percutaneous transluminal angioplasty, the systemic and local fibrinolysis as well as the reconstructive vascular operations are represented.

[Whole blood viscosity in patients with acral arterial occlusive diseases and their modification by rheologically active drugs]. / Die Vollblutviskosität bei Patienten mit akralen arteriellen Durchblutungsstörungen und ihre Beeinflussung durch rheologisch wirksame Medikamente.

Measurements of the whole-blood viscosity in patients with organic and functional disturbances of the acral blood supply were performed. In comparison with the whole-blood viscosity in normal persons patients with acral occlusive diseases showed a significantly increased viscosity. On the other hand, in patients with functional disturbances of the acral blood supply no differences could be established. In a therapy study the good efficacy of rheologically effective medicaments could be demonstrated particularly as combination therapy of pentoxifylline, acetylsalicylic acid and tolazoline in patients with acral occlusive diseases. These medicaments should by all means be used together with the basic therapy. In functional disturbances of the blood supply should predominantly be maintained physiotherapeutic methods of treatment.

[Theses on the evaluation of arterial circulatory disorders of the extremities]. / Thesen zur Begutachtung arterieller Durchblutungsstörungen der Extremitäten.

In an expert opinion of disturbance of the arterial blood supply concerning invalidity the vascular disease must be proved with sufficient ascertainment as well as the functional capacity remained must be estimated. Every expert opinion should contain as far as possible concrete data already in the angiologic-diagnostic minimum programme. In problematic cases supplementations by a special angiological diagnostics are necessary. The criteria of evaluation of arterial obstructive diseases for an expert opinion concerning invalidity are also summarized in theses. Also the relations between disturbances of the peripheral blood supply and effects of injury are discussed. The paper concludes with references to the acknowledgement of a disability card in arterial obstructive diseases and to the motor-car driving ability of patients with vascular diseases.

Species-dependent variables in blood cerebrospinal fluid barrier for proteins.

Cerebrospinal fluid/plasma concentration quotients for immunoglobulin G (I) and albumin (A) were determined in guinea pigs. Age and sex-dependent influences on these quotients (I/A) were analyzed and compared with the values for human lumbar, cisternal and ventricular cerebrospinal fluid. The ratio I/A, which characterizes the molecular size-dependent selectivity of the blood cerebrospinal fluid barrier function for proteins, was found to be a constant in a single species, but showed marked interspecies differences.

[Significance and taxonomy of functional and organic acral circulatory disorders and cutaneous microangiopathies]. / Bedeutung und Systematik funktioneller und organischer akraler Durchblutungsstörungen und kutaner Mikroangiopathien.

Acral disturbances of the blood supply and cutaneous microangiopathies may be associated with functional as well as with organic vascular disturbances. The primary angiopathies are independent clinical pictures, the causes of which are still unknown. In numerous diseases secondary forms of the disturbances of the acral blood supply and the microangiopathies can occur. The systematics represented corresponds to the relevant ambulatory view-points. On the basis of the frequency of several clinical pictures is referred to the importance for the policlinical practice.

[Clinical aspects and differential diagnosis of primary acral circulatory disorders]. / Klinik und Differentialdiagnose der primären akralen Durchblutungsstörungen.

The disturbances of the primary acral blood supply show fluent transitions from the angiopathic position of the reaction over the digitus mortuus to Raynaud's disease. The functional vascular disturbances at stage II of Raynaud's disease change even to an organic arterial process. The various clinical pictures of the angioneuropathies can be differentiated in every ambulatory surgery in the majority of cases with the help of an aimed anamnesis on the basis of the clinical findings and by simple functional tests. When there are facts unclear, various apparative methods of diagnostics or the acral arteriography must be used.

[Conservative therapy of acral circulatory disorders and cutaneous microangiopathies]. / Konservative Therapie akraler Durchblutungsstörungen und kutaner Mikroangiopathien.

Despite the different pathological value of disturbances of the acral blood supply and cutaneous microangiopathies there is a need of treatment of these clinical pictures. It can extend from a simple therapeutic consultation of the patient up to the complex use of adequate rules of life, of physiotherapeutic and pharmacological measures. Under this angle of view the treatment of the angiopathic reactive position, of the digitus mortuus and Raynaud's disease is demonstrated. Of particular interest is the use of new antiviscositants in organic disturbances of the acral blood supply. The treatment of the microangiopathies should also be derived from a complex way of consideration in the sense of therapy step programmes. Taking into consideration the severity of the clinical picture the therapy of acrocyanosis, erythrocyanosis drurum puellarum, cutis marmorata, erythromelalgy, livedo racemosa, perniones, hypertensive and diabetic microangiopathy is discussed. In the secondary forms of the disturbances of the acral blood supply the treatment of the basic disease is in the foreground. The accompanying disturbances of the blood circulation may on principle be treated by means of the same measures, which are promising in the primary clinical pictures.

[Epidemiology of hyperuricemia and gout]. / Epidemiologie der Hyperurikämie und Gicht.

Also in the GDR during the last 10 years the frequency of the disturbances of the purine metabolism increased. With a rate of prevalence of about 20% this anomaly of metabolism reaches the highest percentage of the metabolic disturbances. The increasing accumulation of the disturbances of the purine metabolism on account of complex examinations depends above all on the changed eating and drinking habits of the population. Also influences on body-weight, blood pressure and bodily activities are to be taken into consideration. Sex, age and genetic loads belong to the non-correctable factors of influence. The influences of methodical problems must particularly be taken into consideration in long-term studies. The accumulation of uric arthritis is still relatively small in the GDR in contrast to other industrial countries. However, in our county exact epidemiologic investigations are still necessary.