Dexmedetomidine oromucosal gel for noise-associated acute anxiety and fear in dogs-a randomised, double-blind, placebo-controlled clinical study.

The aim of this randomised, double-blind, placebo-controlled, clinical-field study was to evaluate the effect of dexmedetomidine oromucosal gel at subsedative doses in alleviation of noise-associated acute anxiety and fear in dogs. On New Year's Eve, 182 dogs with a history of acute anxiety and fear associated with fireworks received treatment as needed up to five times: 89 dogs received dexmedetomidine and 93 dogs received placebo. For the primary efficacy variables, dog owners assessed the overall treatment effect as well as signs and extent of anxiety and fear. The overall treatment effect was statistically significant (P<0.0001). An excellent or good treatment effect was reported for a higher proportion of dogs treated with dexmedetomidine (64/89, 72 per cent) than those receiving placebo (34/93, 37 per cent). Additionally, dexmedetomidine-treated dogs expressed significantly (P<0.0314) fewer signs of fear and anxiety despite the noise of fireworks. No local tolerance or clinical safety concerns occurred during the study. This study demonstrated that oromucosal dexmedetomidine at subsedative doses alleviates noise-associated acute anxiety and fear in dogs.

Differences in immune cell invasion into the cerebrospinal fluid and brain parenchyma during cerebral infusion of interleukin-1beta.

Cytokine-mediated inflammatory cell recruitment into the brain is a critical step in the response to diverse insults, including infection, trauma, and stroke. Hence, continous intra-cerebroventricular infusion of interleukin (IL)-1beta leads to an impressive cell invasion into the cerebrospinal fluid, as well as the brain parenchyma. Neither tumor necrosis factor-alpha nor IL-6 induced any significant cell invasion at all. However, the diverse immune cells (granulocytes, monocytes/macrophages) showed a different time course of invasion. Moreover, there was an association between the number of infiltrating immune cells and the infused IL-1 concentration. By analyzing intra-brain immune events, we demonstrated a time- and dose-dependent induction of intercellular adhesion molecule (ICAM)-1, whereas there were no differences for P-selectin, vascular cell adhesion molecule (VCAM)-1, and monocyte-chemotractant protein (MCP)-1, comparing vehicle and IL-1-infused animals. In conclusion, we assume IL-1beta to be a key cytokine for the granulocyte and monocyte recruitment into the central nervous system after various insults. However, granulocytes anticipate monocyte invasion.

Effects of tacrolimus on hemispheric water content and cerebrospinal fluid levels of glutamate, hypoxanthine, interleukin-6, and tumor necrosis factor-alpha following controlled cortical impact injury in rats.

OBJECT: Disturbance of calcium homeostasis contributes to evolving tissue damage and energetic impairment following traumatic brain injury (TBI). Calcium-mediated activation of calcineurin results in production of tissue-damaging nitric oxide and free oxygen radicals. Inhibition of calcineurin induced by the immunosuppressant tacrolimus (FK506) has been shown to reduce structural and functional damage after ischemia. The aims of the present study were to investigate time- and dose-dependent short-term antiedematous effects of tacrolimus following TBI. METHODS: A left temporoparietal contusion (controlled cortical impact injury [CCII]) was induced in 51 male Sprague-Dawley rats. Tacrolimus (1 or 3 mg/kg body weight) was administered by a single intraperitoneal injection at 5 minutes, 30 minutes, or 4 hours after CCII occurred. Control rats received physiological saline. Water contents of traumatized and nontraumatized hemispheres, as well as cerebrospinal fluid (CSF) levels of mediators reflecting tissue damage (the proinflammatory cytokines interleukin [IL]-6 and tumor necrosis factor [TNF]-alpha, the excitotoxin glutamate, and the adenosine triphosphate-degradation product hypoxanthine), were determined 24 hours after trauma. Although CSF levels of IL-6 and TNFalpha were completely suppressed by tacrolimus at all time points and at both concentrations, CSF levels of glutamate and hypoxanthine, as well as edema formation, were only marginally influenced. Significant reduction of cerebral water content was confined to nontraumatized hemispheres. In addition, the higher dose of tacrolimus failed to exert significant antiedematous effects on traumatized hemispheres. CONCLUSIONS: Under the present study design, the potency of tacrolimus in reducing edema formation following CCII seems limited. However, its immunosuppressive effects could be of value in influencing the posttraumatic inflammatory response known to aggravate tissue damage.

Temporal profile of cerebrospinal fluid glutamate, interleukin-6, and tumor necrosis factor-alpha in relation to brain edema and contusion following controlled cortical impact injury in rats.

Traumatic brain injury is associated with release of the excitotoxin glutamate and production of pro-inflammatory cytokines IL-6 and tumor necrosis factor-alpha (TNF-alpha). Following controlled cortical impact injury, cerebrospinal fluid (CSF) glutamate, IL-6, and TNF-alpha concentrations were measured to investigate their relationship to evolving tissue damage. Compared to non-traumatized rats CSF glutamate, IL-6 and TNF-alpha levels were significantly increased by 8 h after trauma (P<0.005). Parallel to increasing brain swelling and contusion CSF glutamate was significantly elevated over time, reaching highest levels by 48 h (33+/-4 microM) while IL-6 and TNF-alpha showed maximum values at 24 h after trauma (42+/-7 and 4.7+/-1 pg/ml) (P<0.005). The observed different temporal profile of CSF glutamate, IL-6, and TNF-alpha following focal traumatic brain injury could be of therapeutic importance.

Continuous infusion of proinflammatory cytokines into the brain to study brain cytokine induced local and systemic immune effects.

Proinflammatory cytokines are produced in the brain after various kinds of insult (ischemia, trauma, infection). In this process interleukin (IL)-1beta, IL-6 and tumor necrosis factor (TNF)-alpha are most important. These cytokines are key mediators of inflammation. Furthermore, these cytokines can act as neurotransmitters and develop direct effects on the central nervous system (CNS) including fever, sleep and stimulation of the neuroendocrine as well as sympathetic nervous system. Moreover, IL-1beta and TNF-alpha may also be involved in brain repair and regenerating processes. However, most of the data about the role of cytokines in the brain have been obtained from either in vitro studies or bolus injections into the brain parenchyma or cerebroventricular system. On the other hand, it is known that cytokines are released continuously into the brain after a cerebral insult over a period of 24 to 48 h. In order to further complete the knowledge about the interactions between neural and immune cells to overcome the primary insult and initiate repair and regeneration in the CNS, a new animal model of local inflammation reaction was established using chronic intracerebral infusion of rat recombinant cytokines.

Brain IL-1beta increases neutrophil and decreases lymphocyte counts through stimulation of neuroimmune pathways.

Leukocytosis after cerebral injury is well described and may participate in the generation of cerebral damage. However, the mechanisms of brain-induced leukocytosis are still speculative. Since it is known that proinflammatory cytokines are involved in neuroimmunomodulation and since others and we have demonstrated high cytokine levels in the cerebrospinal fluid following injury, we supposed that brain cytokines may also influence leukocyte counts. In order to evaluate this hypothesis, we established an animal model using continuous intracerebroventricular (i.c.v.), intrahypothalamic (i.h.), or intravenous infusion of the proinflammatory cytokines tumor necrosis factor (TNF)-alpha and IL-1beta. Controls received vehicle solution. With this experimental paradigm we could show that i.c.v. and i.h. infusion of IL-1beta but not TNF-alpha dramatically increased neutrophil counts, whereas lymphocytes dropped. Blocking the hypothalamic-pituitary-adrenal (HPA) axis by hypophysectomy abolished the neutrophilia, whereas the lymphopenia remained unchanged. Furthermore, application of the beta2-adrenoreceptor antagonist propranolol prevented the decrease of lymphocytes and diminished the neutrophilia. All parameters normalized within 48 h after termination of infusion. So, our results demonstrate that brain IL-1beta can modify blood leukocyte counts through stimulation of both the sympathetic nervous system (SNS) and the HPA axis.

Brain-IL-1beta induces local inflammation but systemic anti-inflammatory response through stimulation of both hypothalamic-pituitary-adrenal axis and sympathetic nervous system.

It is well established that systemic inflammation induces a counter-regulatory anti-inflammatory response particularly resulting in deactivation of monocytes/macrophages. However, recently we demonstrated a systemic anti-inflammatory response without preceding signs of systemic inflammation in patients with brain injury/surgery and release of cytokines into the cerebrospinal fluid (CSF). In order to analyze the mechanisms and pathways of systemic immunodepression resulting from sterile cerebral inflammation we established an animal model using continuous intra-cerebroventricular (i.c.v.) or intra-hypothalamic (i.h.) infusion of rat recombinant (rr) tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta for 48 h. Controls received intra-venous (i.v.) cytokine administration. Interestingly, i.c.v. and i.h. infusion of IL-1beta but not TNF-alpha produced distinct signs of central nervous system (CNS) inflammation. Correspondingly, i.c.v. infusion of IL-1beta particularly diminished the TNF-alpha but increased the IL-10 concentration in whole blood cultures after endotoxin stimulation. All parameters normalized within 48 h after termination of the infusion. Blocking the hypothalamic-pituitary-adrenal (HPA) axis by hypophysectomy (HPX) led to complete recovery of the diminished TNF-alpha concentration and temporarily inhibited the IL-10 increase. Blocking the sympathetic nervous system (SNS) transmission by application of the beta2-adrenoreceptor antagonist propranolol not only inhibited the increase but further downregulated the endotoxin induced IL-10 concentration in the media of whole blood cell cultures, whereas the TNF-alpha decrease was only partially prevented. Interestingly, HPX and propranolol also diminished the cell invasion into the CSF. In summary, activation of both the HPA axis and the SNS plays an important role in systemic anti-inflammatory response resulting from cytokines in brain and cerebral inflammation.

Mechanisms of brain-mediated systemic anti-inflammatory syndrome causing immunodepression.

Overwhelming inflammatory immune response can result in systemic inflammation and septic shock. To prevent excessive and deleterious action of proinflammatory cytokines after they have produced their initial beneficial effects, the immune system can release several anti-inflammatory mediators, including interleukin-10, interleukin-1 receptor antagonist, and soluble tumor necrosis factor receptors, thus initiating a compensatory anti-inflammatory response syndrome. However, in vivo the delicate balance between pro- and anti-inflammatory responses is additionally controlled by the central nervous system. Therefore, proinflammatory cytokines stimulate the hypothalamic-pituitary-adrenal axis and enhance sympathetic nerve system activity. The mediators of these neuroimmune pathways can again suppress immune cell functions to control systemic inflammation. The question is, however, what happens if the immunoinhibitory CNS pathways are activated without systemic inflammation? This can result from production of cytokines in the brain following infection, injury, or ischemia or in response to various stressors (e.g., life events, depression, anxiety) or directly from brainstem irritation. The answer is that this may generate a brain-mediated immunodepression. Many animal and clinical studies have demonstrated a stress and brain cytokine mediated decrease in the cellular immune response at the lymphocyte level. More recently, the importance of monocytes in systemic immunocapacity has been shown. Monocytic inactivation with decreased capability of antigen presentation and depressed secretion of proinflammatory cytokines increases the risk of infectious complications. Interestingly, cytokines in the brain and other stressors can also generate systemic immunodepression at the monocyte level. In this scenario the catecholamine-induced release of the potent anti-inflammatory cytokine interleukin-10 is a newly discovered mechanism of the brain-mediated monocyte deactivation in addition to the "well known" immunosuppressive action of glucocorticoids. Furthermore, other neuropeptides such as alpha-melanocyte-stimulating hormone and beta-endorphin which can be released in stressful situations have also inhibitory effects on immune cells. Thus mediators of the CNS are implicated in the regulation of immune functions and may play a role in both conditioning the host's response to endogenous or exogenous stimuli and generating a "brain-mediated" immunodepression.

Sympathetic activation triggers systemic interleukin-10 release in immunodepression induced by brain injury.

The mechanism of immunodepression after brain injury is not yet clear. Here we demonstrate rapid systemic release of the immunoinhibitory cytokine interleukin-10, monocytic deactivation and a high incidence of infection in patients with 'sympathetic storm' due to acute accidental or iatrogenic brain trauma. In vitro studies showed that within minutes catecholamines trigger the secretion of interleukin-10 from unstimulated monocytes through a beta-adrenoreceptor-mediated, cAMP/protein kinase A-dependent pathway. We found that in a rat model of acute brain injury, the beta-receptor antagonist propranolol prevented the increase of interleukin-10 plasma levels. Rapid monocytic interleukin-10 release after sympathetic activation may represent a common pathway for immunodepression induced by stress and injury.

Diminished monocytic HLA-DR expression and ex vivo cytokine secretion capacity in patients with glioblastoma: effect of tumor extirpation.

Severe immunodysregulation on lymphocyte level has been described in patients with glioblastoma and is likely involved into its unfavorable prognosis. Although the major importance of monocytic cells for immunoregulation is well established, only very limited data exist regarding the monocyte status in glioblastoma patients. Here we demonstrate a markedly diminished monocytic HLA-DR expression and ex vivo cytokine secretion capacity (TNF-alpha, IL-1beta, IL-10) as signs for monocyte deactivation in glioblastoma patients but not in patients with astrocytoma. As known in immunocompromised patients from other reasons, monocyte deactivation indicate global immunodepression associated with an enhanced risk of infectious complications. Interestingly, tumor resection resulted in partial recovery from the monocytic deactivation. This suggests that the glioblastoma itself contributed to this phenomenon. However, IL-10 and the active forms of transforming growth factor-beta2 and -beta1, which are produced by glioblastoma cells and known to inhibit monocyte function, were not detectable in plasma in our patients. Moreover, low levels of the adrenocorticotropic hormone and cortisol excluded hypothalamo-pituitary-adrenal axis involvement. So, further investigations are necessary to clarify the mechanism. The demonstrated severe glioblastoma-associated monocytic deactivation may contribute to its unfavorable prognosis. Therefore, monocytes may represent target cells for new adjuvant immunotherapies in glioblastoma.

IgE binding to a new cross-reactive structure: a 35 kDa protein in birch pollen, exotic fruit and other plant foods.

Food allergies in birch pollen allergic patients have been shown to be due to cross-reactivities of specific IgE antibodies which are directed against birch pollen allergens with related proteins in fruit, nuts and vegetables. We identified a new cross-reactive structure of 35 kDa in birch pollen and some plant food extracts by Enzyme Allergosorbent Test (EAST) and immunoblot inhibition studies. The 35 kDa birch pollen protein is a minor allergen to which approximately 10-15% of birch pollen allergic individuals have specific IgE. Our data demonstrate that there is cross-reactivity of this protein with proteins of comparable size from lychee, mango, banana, orange, apple, pear and carrot. While the 35 kDa protein is immunologically independent of the major birch pollen allergen Bet v 1, we also observed IgE binding to a 34 kDa structure which appears to be a Bet v 1 dimer.

Characterization of the 18-kDa apple allergen by two-dimensional immunoblotting and microsequencing.

A low-temperature extract taken from Golden Delicious apples was separated by two-dimensional polyacrylamide gel electrophoresis. By means of two-dimensional immunoblotting with patients' serum containing IgE specific to Bet v I, a rabbit polyclonal antiserum raised against Bet v I, and two Bet v I specific monoclonal antibodies, epitopes cross-reactive to Bet v I were identified on an apple allergen with a molecular mass of 18 kDa and pI 5.5. Furthermore, certain antibody reactivities with 4 isoproteins of a molecular mass of 16 kDa and pIs ranging from 4.9 to 5.5 were observed, which may indicate the presence of Bet v I related epitopes on these proteins. Based on 26 amino acid residues, N-terminal sequencing of the 18-kDa apple allergen revealed 62% sequence identity between Bet v I from birch pollen and the apple allergen. Our results therefore support the view that both proteins express common as well as non-related IgE-reactive epitopes.

Apple allergy: the IgE-binding potency of apple strains is related to the occurrence of the 18-kDa allergen.

Low-temperature, acetone powder extracts were prepared from mature fruit of 16 apple strains. SDS-PAGE and immunoblot analysis revealed great variation in the relative amounts of the 18-kDa apple allergen in these extracts. EAST (RAST) scores, measured with individual and pool sera from patients allergic to birch pollen and apples, ranged from 0.2 to 4.0 and were related to the relative amount of the 18-kDa protein. These findings were confirmed by ELISA-inhibition assays, dose-related histamine release, semiquantitative evaluation of immunoblots by absorption/reflection densitometry, and skin prick tests with extracts of Golden Delicious, Boskoop, and Jamba apples (corresponding to a high, low, and very low 18-kDa allergen content). Additional open oral challenge tests were performed with two apple-allergic patients and 15 and 16 apple strains. With all methods, the deduced allergenic potency decreased in the following order: Golden Delicious > Boskoop > Jamba. Therefore, we concluded that the IgE-binding potency of apple strains depends on the occurrence of the 18-kDa allergen.

Prediction of risk for pseudoallergic reactions and histamine release in patients undergoing anaesthesia and surgery: a computer-aided model using independence-Bayes.

A computer-aided model for the prediction of pseudoallergic reactions was developed using prospective data collected from 581 patients in a controlled clinical trial examining pseudoallergic reactions to the plasma substitute Haemaccel (outdated formulation). The multivariate analysis of 22 proposed risk factors was performed using Bayes theorem. This enabled the accurate prediction of 86% of the patients who had a systemic reaction. The clinical use of such system would enable a selection of patients to receive the effective prophylactic measure of pretreatment with H1 plus H2-receptor antagonists.

[Heart arrest during dextran infusion despite hapten blockade]. / Herzstillstand unter Dextraninfusion trotz Haptenhemmung.

In a running clinical prospective study on the incidence of adverse reactions to colloidal polysaccharides (randomised, single blind, n = 300) a bronchospasm followed by cardiac arrest occurred during dextran infusion although the necessary hapten blockage with monovalent dextran-1 had been effected. Resuscitation was successful. Directly after this, surgery was carried out as planned under general anaesthesia. The 69-year-old patient was discharged without noticeable sequelae. For the first time in the literature on dextran the studied sample allows a generalisation: The event occurred with an incidence of about 0.9% (of 116 patients who had received dextran infusion). This incidence corresponds to a confidence interval ranging from 0.02 to 4.96%. If the study would be continued as planned, the upper limit of this interval signals the probability of another case of severe intolerance. The diagnosis "dextran adverse reaction" can be made in this case by clinical symptoms. Since no previous or concomitant medication had been administered as provided in the protocol to confirm the diagnosis as an adverse reaction to dextran by determination of the titer of dextran antibodies prior to infusion is not required and it may be concluded that dextran was the causative agent.

Prophylaxis of anaphylactoid reactions to a polypeptidal plasma substitute by H1- plus H2-receptor antagonists: synopsis of three randomized controlled trials.

To demonstrate the efficacy of a premedication with H1- + H2-receptor antagonists against histamine-release responses in anaesthesia and surgery 3 randomized controlled trials were conducted in patients, volunteers and experimental animals (dogs). Cutaneous anaphylactoid reactions following infusion of polygeline (Haemaccel) in orthopedic patients were successfully abolished by premedication with 0.1 mg/kg dimethpyrindene (Fenistil) and 5 mg/kg cimetidine (Tagamet). Chlorpheniramine (Piriton) was also useful, but dimethpyrindene was more effective in the doses recommended and used. Side-effects of the premedication were not observed when the 2 drugs were slowly administered (2 min each). Systemic anaphylactoid reactions following infusion of polygeline were completely prevented in volunteers by the same premedication (0.1 mg/kg dimethpyrindene and 10 mg/kg cimetidine). Life-threatening reactions could not be tested in human subjects, but were elicited in experimental animals (dogs). In this species which resembles man in its sensitivity against histamine, in plasma histamine levels and in response to polygeline life-threatening reactions were prevented or in especially severe cases diminished to such an extent by the premedication with H1- + H2-blockers that this premedication was finally judged to be very effective against histamine-release responses of any grade of severity. To confirm this clinically very important hypothesis more clinical trials in patients at risk for anaphylactoid reactions to drugs are urgently needed.

[Limitation of heat loss in long-lasting paediatric operations by means of a metal foil--positive correlation between room and body temperature (author's transl)]. / Begrenzung des Wärmeverlustes bei langdauernden Kinderoperationen mittels einer Metallfolie unter dem Aspekt positiver Korrelation zwischen Raum- und Körpertemperatur.

A controlled clinical prospective study in 80 children showed the efficiency of an aluminium-coated polyester foil as a protection against heat loss during long-lasting (greater than or equal to 2 h) orthopaedic correcting operations. A pronounced correlation between theatre temperature and the body temperature of the children wrapped in foil could be demonstrated. This method is recommended as a safe and low-cost routine preventive measure for a major part of anaesthetics in paediatric surgery. The foil effect could be completed further by infusion solutions warmed to body temperature and an operation theatre temperature raised to 22-24 degrees C.