Social support of virtual characters reduces pain perception

BACKGROUND

Psychosocial factors, such as social support, can reduce pain. Virtual reality (VR) is a powerful tool to decrease pain, but social factors in VR-based pain analgesia have rarely been studied. Specifically, it is unclear whether social support by virtual characters can reduce pain and whether the perceived control behind virtual characters (agency) and varying degrees of social cues impact pain perception.

METHODS

Healthy participants (N = 97) received heat pain stimulation while undergoing four within-subject conditions in immersive VR: (1) virtual character with a low number of social cues (virtual figure) provided verbal support, (2) virtual character with a high number of social cues (virtual human) provided verbal support, (3) no social support (hearing neutral words), (4) no social support. Perceived agency of the virtual characters served as between-subjects factor. Participants in the avatar group were led to believe that another participant controlled the virtual characters. Participants in the agent group were told they interacted with a computer. However, in both conditions, virtual characters were computer-controlled. Pain ratings, psychophysiological measurements and presence ratings were recorded.

RESULTS

Virtual social support decreased pain intensity and pain unpleasantness ratings but had no impact on electrodermal activity nor heart rate. A virtual character with a high number of social cues led to lower pain unpleasantness and higher feelings of presence. Agency had no significant impact.

CONCLUSIONS

Virtual characters providing social support can reduce pain independent of perceived agency. A more human visual appearance can have beneficial effects on social pain modulation by virtual characters.

SIGNIFICANCE

Social influences are important factors in pain modulation. The current study demonstrated analgesic effects through verbal support provided by virtual characters and investigated modulating factors. A more human appearance of a virtual character resulted in a higher reduction of pain unpleasantness. Importantly, agency of the virtual characters had no impact. Given the increasing use of digital health interventions, the findings suggest a positive impact of virtual characters for digital pain treatments.

Effects of glabellar botulinum toxin injections on resting-state functional connectivity in borderline personality disorder

Meta-analyses suggest a sustained alleviation of depressive symptoms through glabellar botulinum toxin (BTX) injections. This can be explained by the disruption of facial feedback loops, which may moderate and reinforce the experience of negative emotions. Borderline personality disorder (BPD) is characterized by excessive negative emotions. Here, a seed-based resting-state functional connectivity (rsFC) analysis following BTX (N = 24) or acupuncture (ACU, N = 21) treatment in BPD is presented on areas related to the motor system and emotion processing. RsFC in BPD using a seed-based approach was analyzed. MRI data were measured before and 4 weeks after treatment. Based on previous research, the rsFC focus was on limbic and motor areas as well as the salience and default mode network. Clinically, after 4 weeks both groups showed a reduction of borderline symptoms. However, the anterior cingulate cortex (ACC) and the face area in the primary motor cortex (M1) displayed aberrant rsFC after BTX compared to ACU treatment. The M1 showed higher rsFC to the ACC after BTX treatment compared to ACU treatment. In addition, the ACC displayed an increased connectivity to the M1 as well as a decrease to the right cerebellum. This study shows first evidence for BTX-specific effects in the motor face region and the ACC. The observed effects of BTX on rsFC to areas are related to motor behavior. Since symptom improvement did not differ between the two groups, a BTX-specific effect seems plausible rather than a general therapeutic effect.

Botulinum Toxin Therapy for Psychiatric Disorders in Clinical Practice: A Retrospective Case Study

Inhibiting the facial expression of negative emotions via botulinum toxin A (BTX) has been shown to mitigate symptoms of clinical depression in randomized controlled trials. This retrospective case study sought to reproduce the beneficial effects of BTX in a naturalistic setting for major depressive disorder and collect casuistic data on its effect on other mental disorders. Moreover, we describe symptom development across multiple treatment cycles with BTX, and assess the implementation of additional injection targets in the lower face region. Participants were N = 51 adult psychiatric outpatients mainly seeking treatment for depression. Over 50% suffered from comorbid psychiatric conditions, predominantly generalized anxiety disorder (GAD) or borderline personality disorder (BPD). A pre-post case series design was adapted. All participants received BTX-injections in the glabellar region on at least one occasion. Some received additional injections in the mouth region and over multiple treatment cycles. Treatment response was followed up by self-rated scales at varying time intervals post treatment. The results showed that BTX may yield favorable outcomes across multiple and comorbid mental disorders, especially, however, for patients suffering from depression. It potentially prevents the recurrence of clinical symptoms if applied regularly. Adding additional regions of the face does not seem to be superior over applying it to the glabellar region alone. The results add to the growing evidence that BTX therapy is effective in alleviating symptoms of depression. Positive effects can be sustained and reinstated, when applied over multiple treatment cycles. Observed symptom reduction in other psychiatric disorders was less pronounced. Further research is needed to understand the mechanisms by which BTX therapy reduces psychiatric symptoms.

Neuronal effects of glabellar botulinum toxin injections using a valenced inhibition task in borderline personality disorder

Previous studies have indicated that glabellar botulinum toxin (BTX) injections may lead to a sustained alleviation of depression. This may be accomplished by the disruption of a facial feedback loop, which potentially mitigates the experience of negative emotions. Accordingly, glabellar BTX injection can attenuate amygdala activity in response to emotional stimuli. A prototypic condition with an excess of negative emotionality and impulsivity accompanied by elevated amygdala reactivity to emotional stimuli is borderline personality disorder (BPD). In order to improve the understanding of how glabellar BTX may affect the processing of emotional stimuli and impulsivity, we conducted a functional magnetic resonance imaging (fMRI) study. Our hypotheses were (1) glabellar BTX leads to increased activation in prefrontal areas during inhibition performance and (2) BTX decreases amygdala activity during the processing of emotional stimuli in general. Using an emotional go-/no-go paradigm during fMRI, the interference of emotion processing and impulsivity in a sample of n = 45 women with BPD was assessed. Subjects were randomly assigned to BTX treatment or serial acupuncture (ACU) of the head. After 4 weeks, both treatments led to a reduction in the symptoms of BPD. However, BTX treatment was specifically associated with improved inhibition performance and increased activity in the motor cortex. In addition, the processing of negative emotional faces was accompanied by a reduction in right amygdala activity. This study provides the first evidence that glabellar BTX injections may modify central neurobiological and behavioural aspects of BPD. Since the control treatment produced similar clinical effects, these neurobiological findings may be specific to BTX and not a general correlate of symptomatic improvement.

Clinical effects of glabellar botulinum toxin injections on borderline personality disorder: A randomized controlled trial

BACKGROUND

Inhibition of frowning via injections of botulinum toxin A (BTX) into the glabellar region has shown beneficial effects in the treatment of major depression. Preliminary research suggests that improvements in the affective domain are not depression-specific, but may also translate to other psychiatric disorders.

AIM

This 16-week, single-blind, two-center randomized controlled trial investigated the influence of BTX on clinical symptoms of borderline personality disorder (BPD).

METHODS

Fifty-four patients with BPD were randomly assigned to treatment with BTX (n = 27) or a minimal acupuncture (ACU) control condition (n = 27). Clinical outcomes were followed at 2, 4, 6, 8, 12, and 16 weeks. Primary endpoint was the relative score change on the Zanarini Rating Scale for Borderline Personality Disorder (ZAN-BPD) 8 weeks after baseline relative to the control group and adjusted for treatment center. Secondary and additional outcome variables were self-rated borderline symptoms, comorbid symptoms of depression, psychological distress, and clinical global impression.

RESULTS

Participants showed significant improvements at the primary efficacy endpoint in both treatment groups (BTX: M = -0.39, SD = 0.39; ACU: M = -0.35, SD = 0.42), but no superior effect of the BTX condition in comparison with the control intervention was found-F(1,5323) = 0.017, p = 0.68). None of the secondary or additional outcomes yielded significant group differences. Side effects were mild and included headache, transient skin or muscle irritations, and dizziness.

CONCLUSION

Evidence regarding the efficacy of BTX for BDP remains limited, and the design of adequate control conditions presents an opportunity for further research.ClinicalTrials.gov registry: Botulinum Toxin A for Emotional Stabilization in Borderline Personality Disorder (BPD), NCT02728778, https://clinicaltrials.gov/ct2/show/NCT02728778.

Botulinum toxin for the management of depression: An updated review of the evidence and meta-analysis

Botulinum toxin (BTX) treatment of glabellar frown lines is one of the most common procedures in aesthetic medicine. In addition to its cosmetic effect, the neurotoxin has been shown to have a positive influence on mood and affect. Several randomized clinical trials (RCTs) have examined the effect of botulinum toxin on the treatment of depression. Combining the results of the five RCTs in a random effects meta-analysis revealed that patients treated with BTX showed a more intense improvement of depressive symptoms in comparison to subjects that received placebo injections (d = 0.98). Despite methodological limitations, the results of this study emphasize the effectiveness of BTX in the treatment of depression and therefore pave the way for its use in the field of psychiatry.

Development and Assessment of a Simulator for in Vivo Confocal Microscopy in Fungal and Acanthamoeba Keratitis

BACKGROUND AND PURPOSE

In vivo confocal microscopy (IVCM) is a non-invasive imaging technique that allows morphological analysis as a diagnostic approach of the cornea in real time, thus providing a suspected diagnosis of fungal or amoebic keratitis immediately, whereas culture or PCR require several days or even weeks. Since these infections are rare, it is difficult for ophthalmologists to gain the experience necessary to differentiate infection from normal findings or artefacts. The purpose of this project was to establish a simulator, on which physicians could practice as well as acquiring a database of IVCM images of fungal or amoebic keratitis and respective analyses.

PATIENTS AND METHODS

An IVCM simulator was set up with cadaver human corneas, infected with either acanthamoeba, candida or aspergillus. Twenty-one ophthalmologists were trained in IVC microscopy first in a Dry Lab, then practically on the simulator. For evaluation, the participants were asked to fill out a standardized questionnaire, with a pre- and post-course self-assessment.

RESULTS

The self-assessed theoretical and practical skills in differentiating infectious from non-infectious keratitis in IVCM significantly increased (p = 0.0001, p = 0.0002, respectively). The barrier to use this technique decreased (p = 0.0474).

CONCLUSION

A very simple protocol based on a model of ex vivo corneal mycotic and amoebic infections can be used to train novices in the structured approach and diagnostic use of IVCM for corneal infections.

Determinants of Dropout From Correctional Offender Treatment

Research indicates that approximately one third of offenders admitted to social-therapeutic correctional facilities in Germany fail to complete treatment and that treatment dropout is linked to higher recidivism in both sexual and violent offenders. The purpose of this study was to examine determinants of treatment dropout in a social-therapeutic correctional facility in Germany. The sample consisted of 205 incarcerated adult male offenders (49.8% sexual, 38.1% non-sexual violent) admitted to correctional treatment. Completers and dropouts were compared on variables pertaining to demographics, offense type, substance abuse, psychopathy, risk, and protective factors. Univariate analyses showed that treatment dropouts demonstrated significantly higher scores on measures of risk and psychopathy and lower scores on protective factors. Logistic regression analyses identified unemployment, non-sexual violent index offense, higher risk scores (HCR-20), and Facet 1 (interpersonal deficits) of the Psychopathy Checklist-Revised (PCL-R) as significant predictors of treatment dropout. Surprisingly, substance abuse disorder was a negative predictor of dropout. With the exception of substance abuse, the results support the notion that treatment dropouts represent a group of high-risk offenders with particular treatment needs. Practical implications and suggestions for further research are discussed.

Shrink that frown! Botulinum toxin therapy is lifting the face of psychiatry

Treating glabellar frown lines with injections of botulinum toxin is the most frequently applied procedure in aesthetic medicine. In addition to its cosmetic effect, botulinum toxin may also positively modulate mood and affect, which may contribute to its popularity. A series of clinical studies has shown that this modulation can be used in the treatment of major depression. After a single glabellar treatment with botulinum toxin, patients suffering from unipolar depression experienced a quick, strong and sustained improvement in the symptoms of depression. Preliminary data suggest that botulinum toxin therapy may also be effective in the treatment of other mental disorders characterized by an excess of negative emotions, such as borderline personality disorder. Thus, the extreme bottom-up approach of paralyzing the facial muscles to influence the emotional brain via proprioceptive feedback mechanisms may represent a paradigm shift in psychiatric therapy.

Effect of CYP3A5*3 on kidney transplant recipients treated with tacrolimus: a systematic review and meta-analysis of observational studies

The highly variable pharmacokinetics of tacrolimus can hamper the optimal management of kidney transplant patients. This variability has been attributed to the genetic polymorphism of CYP3A5 6986A>G, but the evidence is not clear. We conducted a meta-analysis of studies evaluating the effect of CYP3A5 polymorphism on kidney transplant recipients with tacrolimus plasma concentration divided by daily dose per body weight (C/D) and clinical outcomes. We searched in MEDLINE and EMBASE. We found evidence suggesting a significantly lower C/D among CYP3A5*1 allele carriers compared with carriers of the CYP3A5*3/*3 genotype at weeks 1 and 2, and months 1, 3, 6 and 12. We demonstrated that the expresser genotype might have higher risk of acute rejection and chronic nephrotoxicity. In conclusion, CYP3A5 6986A>G polymorphism can affect tacrolimus pharmacokinetics and the incidence of acute rejection and chronic nephrotoxicity on kidney transplant recipients. Patients at high risk of developing tacrolimus-related complications could be detected even before their kidney transplant.

New approaches in nuclear medicine for early diagnosis of Alzheimer's disease

Dementia, Alzheimer's disease (AD) being the most common cause of it, is a major and growing medical and social problem, particularly in the advanced age, with the highest rate in the population over 75 y. Recent sophisticated therapeutic measures require more sensitive diagnostic tests to recognize early stages of the disease. In this paper, the current neuronuclear imaging literature is reviewed with regard to early and differential diagnosis of dementia. Functional imaging with single photon emission computed tomography (SPECT) and positron emission tomography (PET) could provide the clinician with additional information complementary to morphological assessments, thus contributing to achieve a more adequate diagnosis, and also with information regarding prodromal stages of AD.

Abnormalities of CD4 T cell subpopulations in ANCA-associated vasculitis

In patients with ANCA-associated vasculitis (AAV), CD25 expression is increased on circulating T cells. Although in animal experiments the role of CD4(+) CD25(+) T-regulatory-cells (T(reg)) in protection against autoimmunity is well established, the role of these cells in AAV is unknown. To investigate the hypothesis that an increased expression of CD25 on T cells is related to persistent T cell activation and not to disturbances in T(reg) cells in AAV (34 patients, six of them after renal transplantation), we investigated CD25 expression in different subpopulations of CD4(+) cells and FOXP3 mRNA expression by reverse transcription-polymerase chain reaction (RT-PCR). In addition, T cell proliferation and cytokine secretion after stimulation with anti-CD3 and anti-CD28 and intracellular cytokine production after stimulation with phorbol myristate acetate (PMA)-ionomycin was determined. Controls were non-vasculitic renal transplant patients (n = 9) and healthy controls (HC) (n = 13). In AAV the total number of lymphocytes, CD4(+) lymphocytes and the percentage of naive T cells are lower than in HC and RTX. An increased percentage of CD25(+) cells was found in AAV and AAV/RTX, irrespective of disease activity, but not in HC or RTX. This was confined to the naive (CD4(+) CD45RB(high)) population only. FOXP3 mRNA expression in CD4(+) T cells did not differ between AAV patients and healthy controls. In vitro T cell proliferation was enhanced in AAV patients compared to HC (P < 0.01). PBMC of AAV patients produced significantly less interleukin (IL)-10 and interferon (IFN)-gamma after anti-CD3/CD28 stimulation. The percentage of IL-10 and IL-12, but not IFN-gamma, IL-4 or tumour necrosis factor (TNF)-alpha-producing cells was significantly higher in patients compared to HC. These findings were confined to the memory population of CD4(+) cells. We conclude that AAV patients are lymphopenic and have low numbers of CD4(+) T cells, which seem to be in a persistent state of activation.

Appropriateness of Invasive Cardiovascular Interventions in German Hospitals (2000 - 2001): An Evaluation Using the RAND Appropriateness Criteria

OBJECTIVE

Germany has the highest per capita rate of percutaneous transluminal coronary angioplasties (PTCAs) in Europe and the third highest per capita rate of heart surgeries requiring a heart-lung machine. The goal of this study was to evaluate the appropriateness of PTCA, coronary artery bypass graft (CABG), and carotid endarterectomy (CEA) in German hospitals using RAND appropriateness criteria.

METHODS

A retrospective study in 121 randomly selected German hospitals (52 % of all hospitals contacted) was performed from December 2000 to August 2001. A total of 361 patients were enrolled providing information on the appropriateness of 128 PTCAs, 92 CABGs, and 141 CEAs.

RESULTS

Inappropriateness rates were 2 % (95 % CI 0 - 5 %), 4 % (95 % CI 1 - 9 %), and 3 % (95 % CI 1 - 7 %) for PTCA, CABG, and CEA, respectively. The overall rate of uncertain procedures was 42 % (95 % CI 36 - 47 %). Only 38 % (95 % CI 32 - 45 %) of patients who received a coronary intervention had had a pre-interventional stress test.

CONCLUSIONS

The study yielded little overt overuse in the performance of PTCAs, CABGs, and CEAs, but potentially large underuse of stress tests. Despite a high per capita rate of invasive cardiovascular interventions in Germany, the rate of inappropriate procedures was not larger than in other countries.

Expression of somatostatin receptors in inflammatory lesions and diagnostic value of somatostatin receptor scintigraphy in patients with ANCA-associated small vessel vasculitis

OBJECTIVE

To assess the usefulness of somatostatin receptor (SSTR) scintigraphy for the evaluation of disease activity in the upper and lower respiratory tract in ANCA-associated vasculitis (AASV).

METHODS

Thirty-two consecutive patients with AASV were subjected to SSTR scintigraphy as part of their initial diagnostic evaluation and follow-up. The presence of SSTRs in inflammatory lesions was evaluated with immunohistochemistry in selected cases.

RESULTS

In AASV, specificity of SSTR scintigraphy for active vs non-active disease was 96% for pulmonary disease and 100% for ear, nose and throat (ENT) involvement, while sensitivity was 86% and 68%, respectively. Absence of previously present tracer accumulation characterized treatment responders, and treatment resistance was reflected by repeated positive scintigraphy. We could demonstrate the expression of SSTRs in lung and mucosal biopsies obtained from patients with active Wegener's granulomatosis and with microscopic polyangiitis.

CONCLUSION

SSTR scintigraphy is useful for the assessment of AASV, indicating disease activity, disease extent and treatment efficacy. SSTRs are expressed in both granulomatous as well as non-granulomatous AASV.

Effects of suckling on hypothalamic-pituitary-adrenal axis responses to psychosocial stress in postpartum lactating women

In several studies lactation has been shown to be associated with a hypothalamic-pituitary-adrenal axis hyporesponsiveness to physical and psychological stressors. As it is not known whether the marked blunting of endocrine stress reactivity in women can be ascribed to suckling as a short-term effect or to lactation in general, the acute effects of suckling on the hypothalamic-pituitary-adrenal axis and the sympathetic-adrenal-medullary system responses to mental stress were investigated in lactating women. Forty-three lactating women were randomly assigned either to breast-feed or to hold their infants for a 15-min period with the onset 30 min before they were exposed to a brief psychosocial stressor (Trier Social Stress Test). Both breast-feeding and holding the infant yielded significant decreases in ACTH, total plasma cortisol, and salivary free cortisol (all P < 0.01). There were no significant differences in baseline hormone levels between the groups 1 min before the stress test. In response to stress exposure, ACTH, total plasma cortisol, salivary free cortisol, norepinephrine, and epinephrine were significantly increased in all lactating women (all P < 0.001). However, total cortisol and free cortisol responses to stress were attenuated in breast-feeding women (P = 0.001 and P = 0.067, respectively), who also showed significantly decreasing PRL levels during the stress test (P = 0.005). In addition, there was no change in plasma oxytocin or vasopressin in response to the stressor. Breast-feeding as well as holding led to decreased anxiety (P < 0.05), whereas, in contrast, stress exposure worsened mood, calmness, and anxiety in the total group (all P < 0.001). From these data we conclude that lactation in women, in contrast to that in rats, does not result in a general restraint of the hypothalamic-pituitary-adrenal axis response to a psychosocial stressor. Rather, suckling is suggested to exert a short-term suppression of the cortisol response to mental stress.

Positive imaging of an inflammatory process at an arteriovenous access site with 111 Indium-labeled platelets

Complications associated with the vascular access for hemodialysis represent one of the most important causes of morbidity among patients with renal replacement therapy. Early detection of arteriovenous fistula (AVF) dysfunction is of great interest. We present the case of a 70 year old woman who underwent 111In-oxine-labeled-platelet scintigraphy to evaluate thrombogenicity at 3 weeks and 3 months after surgery of a new AVF. In the first post-operative scintigraphy 4 hours after reinjection of autologous 111In-labeled platelets, enhanced focal activity was visible in the AVF projection which could not be detected after 24 hours. Since early platelet accumulation may reflect hyperemia in inflammation, this diagnosis was verified by anti-granulocyte antibody scintigraphy. The platelet scintigraphy performed 3 months later was negative, with persistence of sufficient AVF function. These data show an intense early accumulation of 111In-oxine-labeled-platelets in unspecific inflammation of an AVF.

Ectopic lobular breast cancer of the vulva

BACKGROUND

Primary breast cancer of the vulvar region is a rare tumor entity. Only 12 cases have been published so far in the literature.

PATIENT AND METHODS

We report on a case of a 60-year old woman with an invasive lobular breast cancer localized to the vulva. The woman with elevated CA 15-3 and CEA markers underwent local wide excision of the tumor and bilateral inguinal lymphonodectomy, adjuvant anthracycline containing chemotherapy and locoregional irradiation including both inguinal regions and subsequent endocrine therapy with tamoxifen.

RESULTS

The resected specimen showed an estrogen receptor-positive diffuse infiltrating lobular breast cancer of the vulva with metastases in both groins. Original tissue of the breast adjacent to the malignant vulvar transformation was lacking. Imaging of the breast was lacking any pathology. Our patient has been followed up for 20 months without any signs of progressive disease.

CONCLUSION

Due to the rare occurrence, we are not able to give general guidelines for the treatment of ectopic breast cancer. However, adjustment of treatment to the therapeutic recommendations for orthotopic breast cancer seems reasonable and effective.

Induction of cell proliferation arrest and apoptosis in hepatoma cells through adenoviral-mediated transfer of p53 gene

BACKGROUND/AIM

Loss of p53 function is common in hepatocellular carcinoma and is associated with an extremely poor prognosis. The aim of the study was to evaluate the biologic effect of adenoviral-mediated gene transfer of wild-type p53 gene in four hepatoma cell lines with different p53 genetic makeup.

METHODS

Recombinant adenovirus expressing wild-type p53 was used. Recombinant adenoviruses with either an empty expression cassette or expressing beta-galactosidase gene served as controls.

RESULTS

High-level expression of wild-type p53 was achieved with adenoviral-mediated gene transfer. The expressed p53 protein showed nuclear localization and its expression was associated with an induction of p21 and bax expression. Expression of the p53 gene was associated with inhibition of tumor cell proliferation and induction of apoptosis. Expression of p53 was also associated with an upregulation of CD95 (Apo-1/Fas) gene expression, which may predispose the tumor cells to undergo apoptosis induced by the Fas Ligand/Fas cytolytic pathway. An additional anti-tumor effect, in terms of allowing the replication-defective adenovirus to replicate, was observed in hepatoma cells with homozygous deletion of p53 genes and to a lesser extent, hepatoma cells with mutated p53 genes.

CONCLUSIONS

These data showed that adenoviral-mediated gene transfer is effective in delivering p53 gene to tumor cells, and the multiple pathways involved in their antitumor activities.

A new liquid homogeneous assay for the determination of HDL-cholesterol. A comparison to precipitation with phosphotungstic acid/MgCl2 and a lyophilized homogeneous assay

We evaluated a new ready to use liquid assay for the homogeneous determination of HDL-cholesterol (HDL-C; Merck, Darmstadt, Germany) in comparison to phosphotungstic acid precipitation and a homogeneous assay, based on sulfated alpha-cyclodextrin and polyethylene glycol-modified enzymes (Roche Diagnostics/Boehringer Mannheim, Germany). The new liquid homogeneous HDL-C assay had inter-assay coefficients' of variation of less than 2.1%. The method is linear up to at least 3.11 mmol/I HDL-C, but even at 4.40 mmol/I the deviation from the expected value is less than 5%. Spinking experiments with low density lipoproteins and very low density lipoproteins proved that the new assay was specific for high density lipoproteins up to cholesterol associated with low density lipoproteins (LDL-C) and very low density lipoproteins (VLDL)-triglyceride concentrations of 18.13 and 22.60 mmol/l, respectively. Free fatty acids above 2mmol/l did not interfere. Icteric samples with bilirubin concentrations between 170 and 400 micromol/l did not show any systematic deviation compared to the precipitation procedure. In addition, serum hemoglobin concentrations up to 7.0 mmol/l and ascorbic acid up to 3000 micromol/l did not interfere with the HDL-C assay. An intermethod comparison including 120 samples revealed good agreement of the liquid HDL-C assay and the precipitation procedure (y = 0.943x + 0.074 mmol/l; r = 0.992). The new homogeneous HDL-C assay is thus precise, comparable and robust. Due to its ease of handling this assay will significantly facilitate attempts to include the differentiation between HDL-C and LDL-C in the routine screening for cardiovascular risk factors and in the monitoring of lipid lowering therapy.

111In-labelled platelets for assessment of thrombogenicity of new haemodialysis vascular access

Using platelet scintigraphy to evaluate early thrombogenicity, we examined 39 new vascular accesses 4 weeks and 3 months after surgery. We found a significant association between platelet deposition and Doppler flow (P < 0.01) and blood pressure (P < 0.01). Compared with arteriovenous fistulae, prosthetic grafts showed significantly higher platelet uptake (after 4 h: 2.4 +/- 1.1 vs 1.2 +/- 1.1 eU, P < 0.05; after 24 h: 2.1 +/- 1.0 vs 0.6 +/- 0.8 eU, P < 0.01) and a higher Doppler flow (1184 +/- 202 vs 609 +/- 342 ml.min-1, P < 0.001). In 8 of 39 accesses, a thrombosis occurred. Accumulation of activity was not related to shunt thrombosis (specificity 61%, sensitivity 71%). We conclude that 111In-platelet scintigraphy is not suitable for the early detection of shunt thrombosis or for identifying patients at risk.

Polycythemia vera megakaryocytes store and release lysozyme to a higher extent than megakaryocytes in secondary polycythemia (polyglobuly)

Lysozyme, a myelomonocytic marker not only exerts bacteriolytic, but also immunomodulatoric properties and was found to bind to the glycosaminoglycan serglycin, an important constituent of the extracellular matrix (ECM). Pathological serum lysozyme levels were described in chronic myeloproliferative disorders (CMPDs) and other hematological conditions. In this context it is remarkable that in polycythemia rubra vera (PV), characterized by a proliferation particularly of the megakaryo- and erythropoiesis, serum lysozyme levels behave independently of the numbers of myelomonocytic cells in peripheral blood. To elucidate whether megakaryopoiesis might be the source of the increased serum lysozyme, we performed an experimental study on isolated and enriched megakaryocytes derived from bone marrow of patients with PV. Findings were compared to a group of patients with reactive (smoker's) polyglobuly (PG). In confirmation of previous results, quantification of serum lysozyme levels showed a slight elevation in the cohort of PV patients which was not correlated with the leukocyte count. Applying an immunohistochemical assay we were able to demonstrate intracytoplasmic lysozyme storage in megakaryocytes. Moreover, performing the reverse hemolytic plaque assay (RHPA), a technique which enables detection of secreted proteins at the single cell level, we found that 54% of the PV, but only 3% of the PG megakaryocytes spontaneously secreted lysozyme. After rhIL-3 treatment the secretion of lysozyme remained unchanged in PV but increased to 14% in PG. These findings suggest that the extent of megakaryocytic lysozyme secretion might discriminate PV from reactive conditions. Although a direct involvement of lysozyme in the regulation of aberrant megakaryopoiesis in PV is not likely, the results of the present study point to the possibility that lysozyme could be involved in the interactions of PV megakaryocytes with ECM. Moreover, the response to rhIL-3 significantly discriminates PV megakaryocytes from megakaryocytes of the PG group.

Polycythemia vera megakaryocytes but not megakaryocytes from normal controls and patients with smokers polyglobuly spontaneously express IL-6 and IL-6R and secrete IL-6

Polycythemia rubra vera (PV) represents a clonal hematological disorder defined by an abnormal expansion of erythroid precursors and megakaryopoiesis, in particular. Ample evidence has been provided that the IL-6/1L-6R complex may be responsible for the proliferation of normal and neoplastic megakaryocytes in vitro and this fact lead us to the hypothesis, that defects in the regulation of IL-6 synthesis take part in the pathogenesis of PV. The study was carried out to determine the IL-6 serum levels and the megakaryocytic IL-6 production in patients with PV and to compare these data with the situation in hematologically healthy donors as well as in patients suffering from spurious polycythemia--smokers polyglobuly (PG). For this purpose, IL-6 serum levels were measured by ELISA and the megakaryocytic production studied by immunohistochemistry, reverse hemolytic plaque assay (RHPA) together with reverse transcription/polymerase chain reaction (RT-PCR) in highly enriched megakaryocyte preparations. In additional experiments, the influence of IL-3 stimulation and the expression of IL-6R were tested. Serum levels of IL-6 did not differ between the three groups under study. In contrast, immunohistochemistry revealed a raised proportion of megakaryocytes expressing IL-6 in PV as compared to normal donors and patients suffering from PG. The percentage of megakaryocytes actively secreting this cytokine as detected by the RHPA was 20 times greater than in both the other groups. This phenomenon was further substantiated by the fact that IL-6 mRNA could only be shown in PV megakaryocyte preparations. The regulation of IL-6 secretion appears to be abnormal in PV. Whereas in the normal and in the PG group IL-3 stimulation exerts a marked increase in megakaryocytic IL-6 secretion, PV megakaryocytes responded with a paradoxical down-regulation of IL-6 synthesis combined with the loss of IL-6R. Our data describe for the first time an abnormally raised IL-6 production by PV megakaryocytes and point towards fundamental regulatory alterations of the IL-6 synthesis in this disease.

Effects of prostaglandin E1 metabolites on the induction of arterial thromboresistance

Prostaglandin (PG) E1 has been shown to induce arterial thromboresistance in experimental animals and in man. It is known to be degraded in vivo to metabolites which have comparable (13,14-dihydro-PGE1) or no (15-keto-PGE1, 15-keto-13,14-dihydro-PGE1) biological activity. It was the goal of this study to examine whether 13,14-dihydro-PGE1 and its derivatives might share biological activity in rendering the arterial wall less thrombogenic. Using a cross-perfusion technique the aorta and iliac artery surface were exposed to a donor rabbits' blood. We examined the intact endothelial lining and a surface which had been deendothelialized before by means of a Fogarty catheter. Donor animals and/or receiver animals were treated daily for 1 week with 13,14-dihydro-PGE1, PGE1, 15-keto-PGE1, 15-keto-13,14-dihydro-PGE1, or the vehicle only, respectively. From the group of the receiver animals, a subgroup of 6 animals each was treated for the same period of time with either 13,14-dihydro-PGE1, PGE1, 15-keto-PGE1, 15-keto-13,14-dihydro-PGE1, or the vehicle. Immediately after the last administration of the respective PG or solvent, native blood from a donor rabbit was circulated [30 mL/min. under in vivo flow conditions (60 Hz)] over an arterial segment of a receiver animal. Deposition of 111Indium-oxine labeled autologous platelets per surface unit was quantitatively assessed. In vitro perfusion data were morphometrically analysed. In animals pretreated with 13,14-dihydro-PGE1 the thromboresistance was almost comparable to that achieved with PGE1. In contrast, pretreatment of the donor animals (platelet) had only minor effects on the thromboresistance. The other compounds showed no effects. In vitro perfusion of human saphenous vein segments revealed PGE1 and 13,14-dihydro-PGE1 again to be of comparable potency, while 15-keto-PGE1 and 15-keto-13,14-dihydro-PGE1 were only active at concentrations being several orders of magnitude higher. Not only PGE1 but also its in vivo formed metabolite PGE0 may play an important role in inducing improvement of haemostatic balance via the vascular wall rather than the platelets. The other metabolites, however, are unlikely to exhibit an effect at biologically relevant concentrations.

Antisense oligonucleotides in neuroendocrinology: enthusiasm and frustration

Antisense oligodeoxynucleotides (ODN) offer the potential advantage to manipulate neuropeptide or neuropeptide receptor expression within the brain transiently and site-specifically, thus providing a tool for neuroendocrinological research into the physiological function of a particular neuropeptide system. In this study, various approaches are introduced which reveal that antisense ODN may exert acute, short-term effects on neuronal responsiveness to afferent stimuli, as well as long-term effects on neuropeptide/receptor protein availability in a given system depending on the duration of treatment. Short-term effects were seen in that oxytocin (OXT) and vasopressin (AVP) antisense ODN affected electrophysiological and secretory parameters of oxytocinergic and vasopressinergic neurons, respectively, as well as their ability to express the Fos protein in response to afferent stimulation a few hours after a single infusion into the hypothalamic supraoptic nucleus. In this study, two methodological approaches to study long-term effects of the antisense ODN are exemplified, in which antisense ODN directed against the mRNA coding for the neuropeptide itself or its receptor were used. The repeated infusion of corticotropin releasing hormone (CRH) antisense ODN into the paraventricular nucleus resulted in reduced immunoreactive CRH, but not AVP, in the external zone of the median eminence. Furthermore, in order to evaluate the receptor-mediated effects of CRH and AVP released locally within the paraventricular nucleus on adrenocorticotropin (ACTH) release from the pituitary, CRH receptor (and also AVP receptor) antisense ODN were repeatedly infused into the hypothalamic nuclei; this treatment resulted in an elevation of stimulated, but not basal, ACTH release into the blood. However, in addition to these obvious antisense effects, results are discussed which demonstrate sequence-unspecific effects of phosphorothioated ODN, suggesting that some of their mechanisms of action are not yet understood.

PGE1-induced arterial thromboresistance is a vascular property as identified by cross-perfusion technique

Prostaglandin (PG) E1 has been shown to improve thromboresistance. This experiment was designed to examine whether an effect on the arterial wall or the platelets is responsible for this phenomenon. Using a cross-perfusion model, the aortic and iliac artery endothelium of rabbits was removed by a balloon catheter before being perfused with blood of donor rabbits. Donor and/or receiver animals were treated with 20 microg PGE1 or vehicle (cyclodextrin) intravenously daily for 1 week. After the last administration of PGE1 or its vehicle, the animals were killed and native blood from a donor rabbit was recirculated (30 ml/min) via a deendothelialized segment of a receiver rabbit. The contact (C) and spread (S) platelets as well as the denuded surface covered with platelet aggregates (> 5 microm in height) were quantified by morphometry. Deposition of (111)In-oxine labeled autologous platelets was quantitatively determined per surface unit. In addition, PGI(2)- and TXB2-formation by the denuded aortic and iliac artery segments was determined. Pretreatment of receiver rabbits with PGE1 resulted in morphometrically assessed decreased platelet adhesion and aggregation, even when the donor rabbit was vehicle-treated. A vehicle-treated receiver rabbit, in contrast, shows platelet deposition comparable to controls, even if the donor rabbit was PGE1-pretreated. Treatment of donor animals with PGE1 did not result in a reduction in thrombogenicity. The beneficial in vivo PGE1 action of decreased arterial thrombogenicity is thus mediated by an effect on the vascular wall rather than on circulating platelets.

Direct hypertonic stimulation of the rat supraoptic nucleus increases c-fos expressionin glial cells rather than magnocellular neurones

We investigated whether hypertonicity acts directly on supraoptic neurones to activate c-fos expression. Hypertonic artificial cerebrospinal fluid was infused into the supraoptic nucleus (SON) via a microdialysis probe implanted 24 h previously. The rats were decapitated after 90 min for immunohistochemistry with a Fos protein antibody. Direct hypertonic stimulation increased Fos protein expression in glial cells, identified by glial fibrillary acidic protein immunoreactivity, but not in magnocellular neurones. Similarly, with in situ hybridisation c-fos mRNA expression was predominantly seen in glial cells. Fos expression in SON neurones was stimulated by systemic hypertonicity even with a microdialysis probe in the SON, and magnocellular neurones expressed Fos after direct microinjection of cholecystokinin-8S into the SON. Thus, while direct hypertonic stimulation of SON neurones activates secretion of vasopressin and oxytocin, the c-fos gene is not activated, unlike following systemic hypertonic stimulation. This indicates that excitation of neuronal electrical and secretory activity does not necessarily lead to activation of the c-fos gene. Activation of c-fos expression in glial cells by direct hypertonic stimulation may reflect their role in regulating brain extracellular fluid composition.

The prostacyclin stimulating plasma factor activity improves thromboresistance only if vascular PGI2-production is intact

PGI2 is important in regulating platelet vessel wall interaction (1). In perfusion chamber experiments the amount of PGI2 formed was inversely related to the amount of platelets deposited (2). In 1978 a plasma factor was described which stimulates vascular PGI2-production (3). In later years, this activity has been monitored in different patient groups (for review see 4). Interestingly, it has been found that diseases associated with an increased bleeding tendency such as uraemia (5) or hepatic failure (6) were associated with an increased PF-activity while others with an enhanced thrombophilia sometimes show an absence of PF-activity (7). Recently, the PGI2 stimulating plasma factor has been purified and cloned (8). It was the aim of these experiments to assess whether PF-activity plays a role in local hemostasis regulation under in-vivo flow conditions and whether this is dependent on the presence of an intact PGI2-formation.

Release of vasopressin within the rat paraventricular nucleus in response to emotional stress: a novel mechanism of regulating adrenocorticotropic hormone secretion?

The effects of emotional stressors on the release of arginine vasopressin (AVP) and oxytocin (OXT) within the rat hypothalamus and the origin and physiological significance of AVP released within the hypothalamic paraventricular nucleus (PVN) were investigated. First, adult male Wistar rats with a microdialysis probe aimed at the PVN or the supraoptic nucleus were exposed to either a dominant male rat (social defeat) or a novel cage. Release of AVP within the PVN was significantly increased in response to social defeat but not to novelty. In contrast to an activation of the hypothalamic-pituitary-adrenal (HPA) system, neither stressor stimulated the hypothalamic-neurohypophysial system (unchanged plasma AVP and OXT and unchanged release within the supraoptic nucleus [AVP] and the PVN [OXT]). Next, we demonstrated by simultaneous microdialysis of the suprachiasmatic nucleus and the PVN that AVP measured in PVN dialysates during social defeat was probably of intranuclear origin. Finally, a mixture of a V1 AVP and the alpha-helical corticotropin-releasing hormone (CRH) receptor antagonists administered via inverse microdialysis into the PVN caused a significant increase in the plasma adrenocorticotropic hormone (ACTH) concentration compared with vehicle-treated controls both under basal conditions and during social defeat, indicating inhibitory effects of intra-PVN-released AVP and/or CRH on HPA system activity. The antagonists failed to affect anxiety-related behavior of the animals as assessed with the elevated plus-maze. Taken together, our results show for the first time that AVP is released within the PVN in response to an emotional stressor. We hypothesize that this intranuclear release provides a negative tonus on ACTH secretion.

[Mechanical/prosthetic protrusion of the mandible: effects on the pharynx]

Pharyngeal Effects: The protrusion of the mandible by prosthetic appliances ("Esmarch-prosthesis") may be a simple therapy for obstructive sleep apnea, but is effective only in rare cases. Aim of this study was the cephalometric investigation of pharyngeal changes by mechanic-/prosthetic mandibular protrusion in respect of the amount of protrusion. Cephalometric investigation was performed in 46 patients before and after mandibular protrusion, subdivided into 3 groups with protrusion of less than 7 mm, 7 to 10 mm, and more than 10 mm. A significant pharyngeal enlargement was found in all patients, but there was no correlation between the amount of protrusion and the amount of pharyngeal enlargement. Mandibular protrusion of more than 10 mm did not necessarily lead to more pharyngeal enlargement. A reliable prognosis of pharyngeal enlargement in respect of the amount of mandibular protrusion is not possible by cephalometric evaluation, even less a reliable prognosis of treatment success in respect of obstructive sleep apnea.

Combined dexamethasone/CRH test in rats: hypothalamo-pituitary-adrenocortical system alterations in aging

Alterations of the hypothalamo-pituitary-adrenocortical (HPA) system are well-known phenomena in human aging as well as under stressful conditions and in psychiatric disorders. Among the various neuroendocrine function tests developed so far, the combined dexamethasone (DEX)/corticotropin-releasing hormone (CRH) test, in which DEX-pretreated subjects receive a single dose of CRH, has proved to be the most sensitive measure of subtle changes in HPA system regulation. To further explore the mechanisms underlying these neuroendocrine abnormalities in an animal model, a combined DEX/CRH test was established in young male Wistar rats. Five days before the experiment, the jugular vein was catheterized under halothane anesthesia for subsequent drug infusion and blood sampling. DEX (30 micrograms/kg) administered at 12.00 h, during the diurnal trough, suppressed the diurnal increase in circulating corticotropin (ACTH) and corticosterone between 18.00 and 20.00 h, during the acrophase. Subsequent CRH (50 ng/kg) infused at 20.00 h provoked a minimal escape from DEX suppression, indicated by a slight increase in ACTH and corticosterone secretion. Therefore, the combination of 30 micrograms/kg DEX given at 12.00 h followed by pituitary-adrenal system stimulation with 50 ng/kg CRH at 20.00 h was defined as the standard DEX/CRH test procedure and was then used in young (3-6 months) and aged male Wistar rats (20-24 months). After DEX treatment, basal ACTH levels between 18.00 and 20.00 h were significantly higher in aged than in young rats (77.6 +/- 23.2 vs. 19.9 +/- 0.9 pg/ml; p < 0.01), indicating resistance of the HPA system to the suppressive effect of DEX. In addition, the ACTH response to subsequent CRH was significantly higher in aged than in young animals (area under the concentration time curve: 3,670 +/- 2,230 vs. 294 +/- 112; p < 0.05). Thus, the HPA system appeared to be profoundly dysregulated in aged male Wistar rats. The elevated basal ACTH levels reflect glucocorticoid nonsuppression, suggesting negative feedback impairment. This is further supported by the elevated ACTH response to a subsequent CRH challenge, which, in addition, may indicate changes in the endogenous synergistic mechanisms of CRH with other corticotropic factors, for instance vasopressin. In summary, the DEX/ CRH test revealed HPA system alterations in aging and can be applied in future studies to further explore the mechanisms underlying the neuroendocrine disturbances during (psycho) pathological states.

Oxytocin released within the supraoptic nucleus of the rat brain by positive feedback action is involved in parturition-related events

Oxytocin is released within the supraoptic nucleus during parturition and suckling. During suckling, such release is important in positive feedback stimulation of oxytocin neurons. We have investigated whether oxytocin released within this hypothalamic nucleus during parturition (1) acts on local receptors to further amplify its own release in a positive feedback manner and (2) is critically involved in the regulation of the delivery process. To examine the effect of the oxytocin antagonist on oxytocin release within the supraoptic nucleus, microdialysates were sampled before and during parturition and either vehicle or the antagonist was infused adjacent to the microdialysis probe directly into the supraoptic nucleus after delivery of the second pup. Intranuclear infusion of an oxytocin receptor antagonist (des-Gly-NH2d(CH2)5[Tyr(Me)2Thr4]OVT; 50 ng/0.5 microliters) significantly (P < 0.01) diminished the parturition-related rise in oxytocin release within the supraoptic nucleus and reduced the number of pups delivered during the first and second 30-min dialysis period compared to vehicle-treated controls. Bilateral infusion of the oxytocin receptor antagonist into the supraoptic nucleus after delivery of the second pup significantly slowed parturition (P < 0.05), although the parturition-related rise in plasma oxytocin concentration was unchanged. In addition, the onset of suckling was significantly affected by the antagonist as indicated by fewer liver pups and fewer surviving pups with milk in their stomachs 24 hours after parturition (P < 0.05). To seek other, periventricular sites of oxytocin action during parturition, oxytocin or the oxytocin antagonist was infused into the lateral cerebral ventricle from the birth of pup 2. Via this route, oxytocin speeded up parturition, but the antagonist was ineffective; thus it appears that periventricular oxytocin-sensitive sites are not normally active in promoting parturition, and can do so. The findings indicate a receptor-mediated positive feedback action of oxytocin on its own release within the supraoptic nucleus during parturition, which seems to be involved in the progress of parturition without significantly affecting circulation oxytocin levels. Oxytocin released within the supraoptic nucleus might be important for the coordinated activation of oxytocin neurons and for the synergistic central and peripheral oxytocin effects involved in the regulation of parturition-related events necessary for the survival of the newborn, including the onset of lactation.

Prenatal diagnosis of diffuse mesangial glomerulosclerosis by ultrasonography: a longitudinal study of a case in an affected family

The 4th child of an Arabian consanguineous family with 2 previous infant deaths due to diffuse mesangial glomerulosclerosis (at the ages of 1 and 44 days) and 1 healthy 3-year old child was followed up by ultrasonography from the 9th until the 35th week of gestation. Ultrasound showed enlarged hyperechogenic kidneys from the 14th week onwards, and the amniotic fluid level was increased to the upper normal limit. An amniocentesis at 14+ weeks of gestation showed a normal male karyotype and normal alpha-fetoprotein levels in amniotic fluid and maternal serum. Albumin and alpha 1-microglobulin levels in the amniotic fluid were within the normal range and not useful for diagnostic purposes. The child was born at the 36th week of gestation and died of renal failure 21 days later. A postmortem renal biopsy specimen revealed diffuse mesangial glomerulosclerosis.

Behavioral consequences of intracerebral vasopressin and oxytocin: focus on learning and memory

Since the pioneering work of David de Wied and his colleagues, the neuropeptides arginine vasopressin and oxytocin have been thought to play a pivotal role in behavioral regulation in general, and in learning and memory in particular. The present review focuses on the behavioral effects of intracerebral arginine vasopressin and oxytocin, with particular emphasis on the role of these neuropeptides as signals in interneuronal communication. We also discuss several methodological approaches that have been used to reveal the importance of these intracerebral neuropeptides as signals within signaling cascades. The literature suggests that arginine vasopressin improves, and oxytocin impairs, learning and memory. However, a critical analysis of the subject indicates the necessity for a revision of this generalized concept. We suggest that, depending on the behavioral test and the brain area under study, these endogenous neuropeptides are differentially involved in behavioral regulation; thus, generalizations derived from a single behavioral task should be avoided. In particular, recent studies on rodents indicate that socially relevant behaviors triggered by olfactory stimuli and paradigms in which the animals have to cope with an intense stressor (e.g., foot-shock motivated active or passive avoidance) are controlled by both arginine vasopressin and oxytocin released intracerebrally.

Acute, sequence-specific effects of oxytocin and vasopressin antisense oligonucleotides on neuronal responses

Antisense oligodeoxynucleotides (antisense) are short length single strands of DNA with base sequences complementary to a length of messenger RNA of a specific gene. They can be taken up by neurons and hybridize with a complementary messenger RNA to selectively interrupt the expression of a particular gene. We now describe neuropeptide-specific, short-latency (within 2-6 h) effects of antisense infused into the supraoptic nucleus on the responses of rat neurohypophysical neurons, in vivo, to various stimuli. Oxytocin antisense specifically (i) reduced the electrophysiological responses of putative oxytocin, but not vasopressin neurons, (ii) inhibited cholecystokinin-induced and electrically stimulated release of oxytocin from the neurohypophysis, and (iii) reversibly abolished cholecystokinin-induced expression of Fos within the supraoptic nucleus. Vasopressin antisense reduced the excitatory responses of vasopressin neurons, but not of oxytocin neurons. As neuropeptide content within the supraoptic nucleus and neurohypophysis remains unaltered at this time, antisense may induce anticipatory, feed-forward alterations in electrical activity in addition to any possible effects on peptide synthesis.