Short Communication: Interaction of Nerve Growth Factor (NGF) and Vascular Endothelial Growth Factor (VEGF) in Healthy Individuals.

NGF and VEGF are known to be involved in different psychiatric diseases. In order to verify hints from basic research that both neurotrophines interact with each other, serum levels of NGF and VEGF were measured in a cohort of 33 healthy individuals and correlated. NGF level was 126.30 pg/mL (±155.43), and VEGF level was 57.28 pg/mL (±44.48). Both factors were significantly correlated, confirming their interaction and legitimising the usage of their respective ratio (0.8 (±0.42)) as a less varying additional marker in prospective studies.

Saliva: a reliable sample matrix in bioanalytics.

Saliva is gaining increasing attention as a bioanalytical sample matrix. Mostly because of the easy and noninvasive collection, it is not only beneficial in endocrinological and behavioral science, but also in pediatrics. Saliva also has the advantage of being the only body fluid which can be collected even during physical exercise, for example, during sportive activities, and there are physiological characteristics that make it superior to serum/plasma or urine for specific scientific questions. This review provides an insight into the physiology of saliva formation, explaining how certain compounds enter this bodily fluid, and gives advice for collection, storage and analytical methods. Finally, it presents a number of reliable and proven applications for saliva analysis from scientific fields including endocrinology, sports medicine, forensics and immunology.

Joint Effects of the Epigenetic Alteration of Neurotrophins and Cytokine Signaling: A Possible Exploratory Model of Affective Symptoms in Alcohol-Dependent Patients?

AIMS: Neurotrophins have been linked to the symptomatology of alcohol dependence. We aimed to investigate a possible association between the methylation of the promoters of both neurotrophins, the serum levels of the cytokines and core symptoms of alcohol dependence as withdrawal severity and anxiety. METHODS: In this study we investigated a possible association between alterations in the methylation of the BDNF IV/NGF I gene promoter and the cytokines tumor necrosis factor α (TNF-α) and interleukin-6 (IL-6) in 55 male alcohol-dependent patients. RESULTS: Mean methylation of the promoter of the BDNF gene was significantly associated with the TNF-α serum levels and the CIWA-score during withdrawal (P < 0.001). Moreover, mean methylation of the NGF I promoter was significantly associated with the IL-6 serum levels and STAI-I score during withdrawal (P < 0.001). CONCLUSION: Our results suggest an association between the epigenetic regulation of both neurotrophins, BDNF and NGF, cytokine release and the symptomatology of alcohol dependence. They imply that changes in the methylation of neurotrophins may contribute to the symptomatology of alcohol dependence by affecting relevant downstream signaling cascades.

Association of testosterone and BDNF serum levels with craving during alcohol withdrawal.

Preclinical and clinical studies show associations between testosterone and brain-derived neurotrophic growth factor (BDNF) serum levels. BDNF and testosterone have been independently reported to influence alcohol consumption. Therefore, we aimed to investigate a possible interplay of testosterone and BDNF contributing to alcohol dependence. Regarding possible interplay of testosterone and BDNF and the activity of the hypothalamic pituitary axis (HPA), we included cortisol serum levels in our research. We investigated testosterone and BDNF serum levels in a sample of 99 male alcohol-dependent patients during alcohol withdrawal (day 1, 7, and 14) and compared them to a healthy male control group (n = 17). The testosterone serum levels were significantly (p < 0.001) higher in the patients' group than in the control group and decreased significantly during alcohol withdrawal (p < 0.001). The decrease of testosterone serum levels during alcohol withdrawal (days 1-7) was significantly associated with the BDNF serum levels (day 1: p = 0.008). In a subgroup of patients showing high cortisol serum levels (putatively mirroring high HPA activity), we found a significant association of BDNF and testosterone as well as with alcohol craving measured by the Obsessive and Compulsive Drinking Scale (OCDS). Our data suggest a possible association of BDNF and testosterone serum levels, which may be relevant for the symptomatology of alcohol dependence. Further studies are needed to clarify our results.

BDNF serum levels and promoter methylation of BDNF exon I, IV and VI in depressed patients receiving electroconvulsive therapy.

We examined potential changes in brain-derived neurotrophic factor (BDNF) serum levels and promoter methylation of the BDNF gene in 11 patients with treatment-resistant major depressive disorder during a series of electroconvulsive therapy (ECT). Blood samples were taken before, 1 and 24 h after ECT treatment sessions 1, 4, 7 and 10. Patients remitting under ECT had significantly lower mean promoter methylation rates, especially concerning the exon I promoter, compared to non-remitters (both p < 0.002). These findings may point to a depression subtype in which ECT is particularly beneficial.

Alcohol-induced changes in methylation status of individual CpG sites, and serum levels of vasopressin and atrial natriuretic peptide in alcohol-dependent patients during detoxification treatment.

Disturbances of volume-regulating peptides like vasopressin (AVP) and atrial natriuretic peptide (ANP) have been described in early abstinent alcohol-dependent patients. In a longitudinal approach, we investigated whether changes in AVP and ANP serum levels correlated to cytosine-phosphatidyl-guanine (CpG) methylation of the respective gene promoters on days 1, 7 and 14 of alcohol withdrawal. We analyzed the blood samples of 99 patients suffering from alcohol dependence alongside age- and BMI-matched controls. Concerning AVP promoter methylation, we observed an interaction between time of measurement and CpG loci with CpG 2 showing a significant increase in methylation from day 1 to 14. Serum levels of AVP were significantly decreased in the patient group. Compared to healthy controls, promoter-related DNA methylation of the ANP promoter was significantly reduced on days 7 and 14. Moreover, we detected a significant interaction between CpG position and group. In both cases the difference was mainly observed at CpG 1. The present study shows significant changes in the methylation status of individual CpG sites of AVP and ANP. Observing respective alterations of AVP serum protein levels in alcohol-dependent patients during detoxification treatment, we consider methylation as a possible mode of regulation for these proteins during alcohol detoxification.

Atrial natriuretic peptide, arginine vasopressin peptide and cortisol serum levels in opiate-dependent patients.

Preclinical studies suggest that chronic drug abuse profoundly alters stress-responsive systems. The best studied of the stress-responsive systems in humans is the hypothalamic-pituitary-adrenal (HPA) axis. Apart from cortisol, arginine vasopressin peptide (AVP), and atrial natriuretic peptide (ANP) are known to directly impact upon the HPA axis in addictive behavior. We investigated alterations in ANP, AVP and cortisol serum levels in opiate-dependent patients who received diacetylmorphine treatment within a structured opiate maintenance program. ANP serum levels were significantly increased in opiate-dependent patients as compared to healthy controls, whereas AVP and cortisol serum levels were reduced. The ANP, AVP and cortisol serum levels were not significantly associated with the psychometric dimensions of heroin craving. In conclusion, chronic drug abuse profoundly alters stress-responsive systems like the HPA axis. Alterations of AVP, ANP and cortisol appear to constitute an important component in the neurobiology of opiate-dependent patients.

Comparison of salivary cortisol as measured by different immunoassays and tandem mass spectrometry.

Assessing the amount of bioavailable cortisol in saliva with immunoassays and thus sampling an endocrine marker of hypothalamus-pituitary-adrenal axis activity is of major interest in both research and clinical practice. However, absolute cortisol concentrations obtained with different immunoassays (IAs) are barely comparable precluding direct comparison between studies or individuals whenever cortisol analyses were not based on the same IA. The present technical report aims to solve this problem by evaluating the validity of, as well as agreement between the most commonly used immunoassays in psychoneuroendocrinological research (i.e., IBL, DRG, Salimetrics, DSL, and DELFIA) and a reference method (LC-MS/MS) in a sample of 195 saliva specimen covering the whole range of cortisol concentrations in adults. A structural equation modelling framework is applied to decompose systematic assay variance and estimate cortisol reference values, which are adjusted for measurement error and interference of salivary cortisone. Our findings reveal nonlinear relations between IAs and LC-MS/MS, which are discussed in terms of IA cross-reactivity with saliva matrix components. Finally guidelines for converting cortisol concentrations being obtained by these immunoassays into comparable reference values are proposed by providing conversion functions, a conversion table, and an online conversion tool.

Epigenetic down regulation of nerve growth factor during alcohol withdrawal.

We investigated the Cytosin-phosphatidyl-Guanin (CpG) island promoter methylation (mean and methylation of individual CpG-sites) of the nerve growth factor (NGF) gene in the blood of alcohol-dependent patients (57 male patients) during withdrawal (days 1, 7 and 14). Methylation and NGF serum levels did not change significantly from days 1-7. From days 7-14, mean methylation increased (F = 30.55, P < 0.001), whereas the NGF serum levels decreased significantly (days 7-14: F = 17.95, P < 0.001). The NGF serum levels were significantly associated with the mean methylation of the investigated CpG-sites (F = 1.55, P < 0.001). These results imply an epigenetic regulation of the NGF gene during alcohol withdrawal.

Association of nerve growth factor and vascular endothelial growth factor A with psychometric measurements of opiate dependence: results of a pilot study in patients participating in a structured diamorphine maintenance program.

Preclinical study results suggest that neurotrophic peptides like nerve growth factor (NGF) and vascular endothelial growth factor A (VEGF-A) may be associated with symptoms of addictive behavior like withdrawal symptoms and rewarding effects. We investigated alterations in NGF and VEGF-A serum levels in opiate-dependent patients (25 male patients), who received diamorphine (DAM, heroin) treatment within a structured opiate maintenance program, and compared the results with the NGF and VEGF-A serum levels of healthy controls (23 male controls). NGF and VEGF-A serum levels were assessed before and after DAM administration twice a day (in the morning (16 h after last application--t1) and in the afternoon (7 h after last application--t3)) in order to detect a possible immediate or summative (in the afternoon) heroin effect on these two neuropeptides. Moreover, we investigated possible associations between the serum levels of these neurotrophic growth factors and psychometric dimensions of addictive behavior, e.g. craving, withdrawal, depression. Whereas there was no direct effect of DAM application on the serum levels of both neurotrophic growth factors neither in the morning nor in the afternoon, the NGF serum levels of the patient group were found to be significantly increased at all four time points of investigation compared with the healthy controls. In contrast, VEGF-A serum levels did not differ significantly in the patient and control groups. We found a significant positive association between the NGF serum levels and several items of the short opiate withdrawal scale as well as a negative association between self-reported mood (measured by visual analogue scale) and mood before heroin application (in the morning as in the afternoon). Moreover, we found a significant positive association between the NGF serum levels (t1 and t3) and the self-reported craving for methadone. In contrast, we found a negative association between the VEGF-A serum levels and avoidance, anxiety, suicide intentions of the SCL-90 as well as a positive association between the VEGF-A serum levels and the subscales of the heroin craving questionnaire measuring the rewarding effects of heroin. In conclusion, the results of this pilot study show that there might be an association between symptoms of opiate dependence and withdrawal and serum levels of VEGF-A and NGF.

Salivary cytokines in cell proliferation and cancer.

While the presence of multiple systemic steroids, amines and peptides in saliva has been reported, other hormones of the circulation do not appear in saliva. Substances present within saliva may be classified in different groups: first, those which passively display blood plasma concentrations and constitute a promising alternative to evaluate certain systemic parameters. Second, molecules which seem to play a more active, regulatory role within the upper gastrointestinal tract. Concerning the latter, a growing awareness, especially with regards to salivary peptides has been established. Up to now, understanding the distinct effects of salivary peptides known so far is in its infancy. Various publications, however, emphasize important effects of their presence. Salivary peptides can influence inflammatory processes and cell proliferation in epithelia of the upper digestive tract. These include transforming growth factors (TGFs), epidermal growth factors (EGFs), vascular endothelial growth factors (VEGFs) as well as amines such as melatonin. Of those, candidate cytokines like interleukin 8, tumor necrosis factors (TNFs) and leptin are involved in neoplastic activities of salivary glands and the oral cavity. The exact mechanisms of action are not yet completely understood, but their presence can be utilized for diagnostic purposes. Salivary gland tumors in patients may, in certain circumstances, be identified by saliva diagnostics. Saliva samples of the concerned patients, for instance, reveal significantly higher leptin concentrations than those of healthy individuals. Numerous studies postulate that, beside single indicators, the establishment of salivary hormone profiles may assist clinicians and researchers in detecting tumors and other pathologies of the oral cavity, including adjacent tissues, with high sensitivity and specificity.

Decreased galanin serum levels are associated with alcohol-craving during withdrawal.

BACKGROUND: The hypothalamic galanin expression has been associated with increased intake of carbohydrates and fats in preclinical studies. The appetite stimulating effect of galanin is thought to underlie the positive association between alcohol consumption and hypothalamic galanin expression observed in preclinical studies. METHODS: In this pilot study we investigated alterations in galanin serum levels (33 male patients) in alcohol-dependent patients during alcohol withdrawal (days 1, 7 and 14) in comparison to healthy controls (19 male controls). In order to assess the putative association between appetite regulation, galanin serum levels and alcohol consumption we additionally investigated the serum levels of insulin, glucose and triglycerides. RESULTS: The galanin serum levels on day 1 of alcohol withdrawal were significantly reduced in the alcohol-dependent patients (T=-3.302, p=0.002) and increased significantly from day 1 to day 14 of alcohol withdrawal (F=6.437, p=0.002). We found a significant negative association between the galanin serum levels and alcohol craving measured by the Obsessive Compulsive Drinking Scale (OCDS) (r=-0.449, p=0.009) and the obsessive subscale of the OCDS (r=-0.521, p=0.002) on day 1 of alcohol withdrawal. There was no association between the galanin serum levels and the parameters of energy homeostasis (triglycerides, cholesterol, insulin, and glucose) investigated. CONCLUSIONS: Acute alcohol withdrawal was associated with decreased galanin serum levels in this pilot study. There was no association between the galanin serum levels and the parameters of energy homeostasis. Further research of galanin serum levels in active drinkers will be necessary to clarify the putative association between galanin serum levels, appetite regulation and alcohol consumption.

Prolactin serum levels during alcohol withdrawal are associated with the severity of alcohol dependence and withdrawal symptoms.

BACKGROUND: Prolactin serum levels have been described to be elevated during alcohol withdrawal in alcohol-dependent patients and normalize during abstinence. Alterations in prolactin levels may reflect disturbances of dopaminergic neurotransmission which is of crucial importance for alcohol-seeking behavior. METHODS: In this longitudinal observational study, we investigated prolactin serum levels in 99 male patients during the first 14 days of alcohol withdrawal and early abstinence and in 43 healthy controls. To assess the severity of alcohol dependence, the extent of withdrawal symptoms, craving, depressive symptoms, and anxiety, we employed a structured interview including psychologic measurements. RESULTS: Prolactin serum levels were elevated during the whole study period in alcohol-dependent patients compared to the healthy control group. Prolactin levels at admission (first day of alcohol withdrawal) were associated with the severity of alcohol withdrawal (CIWA-Ar) and of alcohol dependence (SESA) but not with the other assessed psychologic parameters. CONCLUSIONS: The presented findings confirm that prolactin is significantly elevated in alcohol-dependent patients during alcohol withdrawal and early abstinence, not showing a rapid decline after cessation of drinking. The association with the severity of withdrawal and dependence may reflect at least partially the individual alterations in the dopaminergic and glutamatergic pathways.

BDNF and GDNF serum levels in alcohol-dependent patients during withdrawal.

Preclinical study results suggest that brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF) modulate addictive behaviour. Therefore we investigated alterations in BDNF (81 male patients) and GDNF serum levels (52 male patients) in alcohol-dependent patients during alcohol withdrawal (day 1, 7 and 14) in comparison to healthy controls (41 male controls). BDNF serum levels were not significantly altered in alcohol-dependent patients compared to healthy controls (p=0.685). GDNF serum levels were significantly reduced in the alcohol-dependent patients (p<0.001). BDNF (p=0.265) and GDNF (p=0.255) serum levels did not change significantly during alcohol withdrawal. BDNF serum levels were significantly negatively associated with alcohol withdrawal severity on day 1 (CIWA-Ar score, p=0.004). GDNF serum levels were significantly negatively associated with individual estimation of alcohol tolerance (SESA-XT score, p=0.028). There was no further association with psychometric dimensions of alcohol withdrawal. In conclusion we found that GDNF serum levels are significantly reduced in alcohol-dependent patients. GDNF serum levels were negatively associated with alcohol tolerance. Moreover BDNF serum levels were found to be associated with withdrawal severity.

Influence of gestational age, cesarean section, and type of feeding on fecal human beta-defensin 2 and tumor necrosis factor-alpha.

OBJECTIVE: : Development of the mucosal immune system is essential for controlling antigenic response. External factors are known to influence the immune system, such as breast-feeding or the mode of delivery. The aim of the present study was to investigate maturation of the enteric immune system. PATIENTS AND METHODS: : In stool samples of 59 preterm and term-born infants we measured the concentration of human beta-defensin 2 (HBD 2), an endogenous antimicrobial peptide, and tumor necrosis factor-alpha (TNF-alpha), a cytokine playing a central role in mucosal inflammation, by enzyme-linked immunosorbent assay. RESULTS: : Mode of delivery as well as nutrition (breast-feeding or formula) had no influence on the fecal concentration of HBD-2 or TNF-alpha, but there was a significant increase in the concentration of HBD-2 in correlation with gestational age. TNF-alpha showed no change in concentration. CONCLUSIONS: : Low fecal HBD-2 may be a risk factor in preterm infants to develop neonatal enteric disease, such as necrotizing enterocolitis.

Serum levels of vascular endothelial growth factor A increase during alcohol withdrawal.

Vascular endothelial growth factor A (VEGF-A) is a key regulator of angiogenesis. This study investigated VEGF-A serum levels during alcohol withdrawal (days 1, 7 and 14, 76 male patients, 38 healthy controls). Patients showed significantly higher VEGF-A serum levels (t = 2.620, P = 0.010), which increased significantly during withdrawal (F = 4.484, P = 0.014, mean difference = -36.835, P = 0.037). The increase of VEGF-A serum levels was significantly associated with initial breath alcohol concentration and the sumscore of the severity scale of alcohol dependence (SESA questionnaire, F = 5.252, P = 0.008). Increase of VEGF-A serum levels is closely associated to alcohol intoxication and severity of alcohol dependence.

The physiological role of hormones in saliva.

The assessment of hormones in saliva has gained wide acceptance in clinical endocrinology. To date, there is no hypothesis as to why some hormones can be found in saliva, while others cannot, and whether there is a physiological consequence of this fact. A number of carefully performed studies give examples of important physiological hormonal activity in saliva. Steroids, such as androgens, act as pheromones in olfactory communication of various mammalian species, such as facilitating mating behavior in swine or serving as odor cues for rodent nestlings. Salivary peptide hormones, such as epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha), and amines such as melatonin, are involved in the regulation of inflammatory processes and in the promotion of cell proliferation, and contribute to a rapid wound healing in the oropharyngeal epithelia. Current data provide evidence of the involvement of salivary cytokines, such as interleukin-8 and leptin, in tumorgenesis in the oral cavity and the salivary glands. The tumor tissues express and release significantly more of these cytokines than healthy glands. Consequently, the assessment of salivary hormone profiles may provide promising targets for diagnostic tumor markers.