Glucose metabolic changes in the prefrontal cortex are associated with HPA axis response to a psychosocial stressor

The prefrontal cortex (PFC) has been well known for its role in higher order cognition, affect regulation and social reasoning. Although the precise underpinnings have not been sufficiently described, increasing evidence also supports a prefrontal involvement in the regulation of the hypothalamus-pituitary-adrenal (HPA) axis. Here we investigate the PFC's role in HPA axis regulation during a psychosocial stress exposure in 14 healthy humans. Regional brain metabolism was assessed using positron emission tomography (PET) and injection of fluoro-18-deoxyglucose (FDG). Depending on the exact location within the PFC, increased glucose metabolic rate was associated with lower or higher salivary cortisol concentration in response to a psychosocial stress condition. Metabolic glucose rate in the rostral medial PFC (mPFC) (Brodman area (BA) 9 and BA 10) was negatively associated with stress-induced salivary cortisol increases. Furthermore, metabolic glucose rate in these regions was inversely coupled with changes in glucose metabolic rate in other areas, known to be involved in HPA axis regulation such as the amygdala/hippocampal region. In contrast, metabolic glucose rate in areas more lateral to the mPFC was positively associated with saliva cortisol. Subjective ratings on task stressfulness, task controllability and self-reported dispositional mood states also showed positive and negative associations with the glucose metabolic rate in prefrontal regions. These findings suggest that in humans, the PFC is activated in response to psychosocial stress and distinct prefrontal metabolic glucose patterns are linked to endocrine stress measures as well as subjective ratings on task stressfulness, controllability as well as dispositional mood states.

Review: Brain—immune communication psychoneuroimmunology of multiple sclerosis

The central nervous system (CNS) and the immune system are two extremely complex and highly adaptive systems. In the face of a real or anticipated threat, be it physical (eg, infection) or psychological (eg, psychosocial stress) in nature, the two systems act in concert to provide optimal adaptation to the demanding internal or environmental conditions. During instances of well being, the communication between these two systems is well tuned and balanced. However, a disturbed crosstalk between the CNS and the immune system is thought to play a major role in a wide series of disorders characterized by a hyporesponsive or hyperresponsive immune system. In multiple sclerosis (MS), a chronic inflammatory and neurodegenerative disease, an excess of inflammatory processes seems to be a hallmark and there is growing evidence for a disturbed communication between the CNS and the immune system as a crucial pathogenic factor. While the exact mechanisms for these phenomena are still poorly understood, the young discipline of psychoneuroimmunology (PNI), which focuses on the mechanism underlying the brain to immune crosstalk, might offer some insights into the existing pathogenic mechanisms. Findings from the field of PNI might also help to gain a better understanding regarding the origin and course of MS clinical symptoms such as fatigue and depression.

Psychoneuroimmunology--cross-talk between the immune and nervous systems

Psychoneuroimmunology is a relatively new field of study that investigates interactions between behaviour and the immune system, mediated by the endocrine and nervous systems. The immune and central nervous system (CNS) maintain extensive communication. On the one hand, the brain modulates the immune system by hardwiring sympathetic and parasympathetic nerves (autonomic nervous system) to lymphoid organs. On the other hand, neuroendocrine hormones such as corticotrophin-releasing hormone or substance P regulate cytokine balance. Vice versa, the immune system modulates brain activity including sleep and body temperature. Based on a close functional and anatomical link, the immune and nervous systems act in a highly reciprocal manner. From fever to stress, the influence of one system on the other has evolved in an intricate manner to help sense danger and to mount an appropriate adaptive response. Over recent decades, reasonable evidence has emerged that these brain-to-immune interactions are highly modulated by psychological factors which influence immunity and immune system-mediated disease.

Altered distribution of leukocyte subsets and cytokine production in response to acute psychosocial stress in patients with psoriasis vulgaris

Psoriasis (PSO) is a mainly T helper-type 1 (TH(1)) cell mediated chronic inflammatory skin disease characterized by epidermal hyperproliferation and psoriatic plaques. There is ample evidence that stress may trigger psoriatic eruption, however, the underlying mechanisms of stress-induced exacerbation of PSO are poorly understood. The specific goal of the present study was to investigate the impact of acute stress on pathologically relevant immune functions in PSO patients. PSO patients (n=23) and healthy controls (n=25) were exposed to a standardized laboratory stressor ("Trier Social Stress Test", TSST) including a free speech and mental arithmetics in front of an audience. Blood samples were collected 10min before and 1, 10, 20, and 60min after the TSST as well as 24h after the experiment at identical time points under resting conditions. Analyses of leukocyte subsets indicated a significantly increased number of leukocyte subpopulations (lymphocytes, granulocytes, CD3(+), CD8(+), CD16(+)/CD56(+), and CD3(+)/HLA-DR(+)) after the TSST (all p<.01) with no significant between-group differences. However, monocyte number (F(3,120)=2.7; p<.01) and number of CD4(+)cells (F(3,120)=3.09; p<.05) were found to be significantly higher in PSO sufferers than in controls. Moreover, a significant decrease of CD3(+)/CD25(+)cells was observed in the PSO, but not in the control group (F(3,120)=3.46; p<.05). After exposure to the TSST, stimulation of peripheral blood mononuclear cells (PBMCs) with phytohemagglutinin (PHA) resulted in elevated production of IFN-gamma (F(3,126)=6.9; p<.001) and IL-2 (F(3,123)=6.6; p<.001), and moreover, a decreased production of IL-10 (F(3,132)=5.22; p<.01) and IL-4 (F(3,129)=3.9; p<.01). No difference in stress-induced changes of cytokine production to PHA could be identified between the two experimental groups (all p>.05). The present findings suggest that acute psychosocial stress is associated with changes of immune functions known to be involved in PSO which may be one potential explanation of how stress may trigger psoriatic eruption.

Endocrine stress responses in TH1-mediated chronic inflammatory skin disease (psoriasis vulgaris)--do they parallel stress-induced endocrine changes in TH2-mediated inflammatory dermatoses (atopic dermatitis)?

In previous research we reported attenuated responsiveness of the hypothalamus-pituitary-adrenal (HPA) axis and further, an increased reactivity of the sympathetic adrenomedullary (SAM) system to stress in patients suffering from atopic dermatitis (AD). AD is a chronic inflammatory skin disease mainly triggered by TH(2)-dependent inflammatory processes. The specific goal of the present study was to investigate whether altered HPA axis and SAM system responsiveness to stress can also be found in TH(1)-mediated inflammatory conditions. Patients with psoriasis (PSO; n=23), a TH(1)-mediated inflammatory (autoimmune) skin disease and healthy controls (n=25) were exposed to a standardized laboratory stressor (TSST) which mainly consists of a free speech and a mental arithmetic task in front of an audience. To investigate HPA axis and SAM system responsiveness, cortisol, ACTH, and catecholamines were determined before and after the stress test. In addition, cortisol levels after awakening and cortisol levels during the day (short diurnal profile) were determined. In order to test feedback sensitivity of the HPA axis, a dexamethasone (DEX) suppression test (0.5 mg) was performed. Analysis of cortisol and ACTH levels after the stress test yielded no significant differences between PSO subjects and controls indicating no altered HPA axis function in this patient group. Further, no between-group differences were found in cortisol levels after awakening or during the day (short diurnal profile). Additionally, no difference between PSO and healthy subjects in the feedback sensitivity of the system could be found (DEX test). However, PSO patients showed elevated epinephrine (F(3,102)=4.7; p<0.005) and norepinephrine (F(3,135)=2.7; p<0.05) levels in response to the stress test when compared to the controls. These findings suggest no altered HPA axis responsiveness, but increased reactivity of the SAM system in TH(1)-mediated chronic inflammatory skin disease.

Complete elastic tensor through the first-order transformation in U2Rh3Si5

The complete elastic tensor of U(2)Rh(3)Si(5) has been determined over the temperature range of 5-300 K, including the dramatic first-order transition to an antiferromagnetic state at 25.5 K. Sharp upward steps in the elastic moduli as the temperature is decreased through the transition reveal the first-order nature of the phase change. In the antiferromagnetic state the temperature dependence of the elastic moduli scales with the square of the ordered moment on the uranium ion, demonstrating strong spin-lattice coupling. The temperature dependence of the moduli well above the transition indicates coupling of the ultrasonic waves to the crystal electric field levels of the uranium ion where the lowest state is a singlet. The elastic constant data suggest that the first-order phase change is magnetically driven by a bootstrap mechanism involving the ground state singlet and a magnetically active crystal electric field level.

Variability of duration of action of neuromuscular-blocking drugs in elderly patients

BACKGROUND

Steroid-based, non-depolarizing neuromuscular-blocking (NMB) drugs (e.g. rocuronium, vecuronium) are characterized by organ-dependent elimination and significantly longer durations of action in elderly compared to young patients. Cisatracurium is a benzylisoquinolinium NMB drug with a duration of action not altered by ageing. The objective of the study was to determine if elderly patients had less variability in duration of action with 2 x ED95 of cisatracurium compared to equipotent doses of rocuronium or vecuronium.

METHODS

Informed consent was obtained from 66 elderly patients with normal renal and liver function. Preoperative midazolam (1 mg) was given IV. The anaesthestic induction was with 5 mg kg(-1) thiopental and 2 microg kg(-1) fentanyl. The patients received 0.6 mg kg(-1) rocuronium, 0.1 mg kg(-1) vecuronium or 0.1 mg kg(-1) cisatracurium. Anaesthetic maintenance was with sevoflurane in oxygen/nitrous oxide. Neuromuscular-blocking duration of action was defined as the return of T1 twitch height to 25% of control. Variability was determined by subtracting the actual duration of action from the mean duration of action for each drug.

RESULTS

The durations of action (range, min) were: cisatracurium, 37-81; vecuronium, 35-137; and rocuronium, 33-119. The median of the variability of duration was significantly less with cisatracurium (7 min) compared to vecuronium (18 min) and rocuronium (18 min) (P < 0.05).

CONCLUSION

When used with sevoflurane/N(2)O, there was a two-fold greater variability of duration of neuromuscular blockade in elderly patients receiving rocuronium or vecuronium compared with cisatracurium.

Circadian regulation of cortisol after hippocampal damage in humans

BACKGROUND

There is substantial evidence that the hippocampus (HC) regulates the activity of the hypothalamic-pituitary-adrenocortical (HPA) axis. Damage to the HC in animals produces a transient alteration in diurnal and stress-related HPA activity. This study was designed to examine the effects of HC damage on basal cortisol secretion in humans.

METHODS

Salivary cortisol was measured in 22 patients with HC damage (12 with bilateral damage and 10 with unilateral damage), 7 brain-damaged comparison participants, 10 healthy, age-matched comparison participants, and 6 of the patients' caregivers. Salivary cortisol samples were taken immediately after awakening, 30 min after awakening, at 8:00 am, 11:00 am, 3:00 pm, 6:00 pm, and at bedtime on a single day. Brain-injured patients underwent a structural magnetic resonance imaging scan to examine quantitative volumes of the HC.

RESULTS

Both bilateral and unilateral HC damage abolished the cortisol response to awakening documented in the comparison groups. Caregivers of bilateral HC patients showed a reduced response to awakening. The remainder of the circadian pattern was not affected in the HC patients; all groups showed a significant diurnal variation. There was no association between HC volume and cortisol secretion.

CONCLUSIONS

Hippocampal damage in humans abolishes the cortisol response to awakening, whereas the remainder of the diurnal cycle is unaffected in these patients. These data suggest a unique role of the HC in the control of basal cortisol secretion.

Autologous concentrated platelet-rich plasma (cPRP) for local application in bone regeneration

Platelets are rich in growth factors that may contribute to an accelerated tissue regeneration process. The therapeutic osteogenic effect of local platelet administration probably depends on the amount of growth factors delivered within. To improve platelet-derived factor preparations, the platelets have to be concentrated without loss of the granular growth factor load. An autologous procedure according to the Good Manufacture Practice (GMP) guidelines to prepare a high concentrate from platelet-rich plasma (cPRP) for clinical application in bone regeneration is presented. Platelet-rich plasma (PRP) was generated from the centrifugation supernatant of 250 ml anticoagulated autologous blood. The PRP was then further centrifuged at the day of operation to generate concentrated PRP (cPRP) in 8 ml plasma. The data from 34 patients (9 m, 25 f), ageing from 21 to 71 years (median 50.4) were evaluated. Both, the platelet counts as well as the TGF-beta1 concentrations in the cPRP were found to be 12-fold increased compared to the PRP values. Overall, a 17-fold increase in platelet concentrations was achieved compared to the patients' whole bloods and platelet counts correlated with increased levels of TGF-beta1 within the cPRP. These results give rise to quality control specifications for a safe and cost effective preparation of cPRP. The method has proven to be suitable for blood services to support the needs for treatment in oral and maxillofacial surgery.

Respiratory syncytial virus infection of the lower respiratory tract: radiological findings in 108 children

For years the typical appearance of respiratory syncytial virus (RSV)-induced infection of the lower respiratory tract has been discussed. All available studies have led to different results. The aim of this study was to control these results, with 108 children. The age range was 1 day to 10 years (median 7 months). Within 72 h of admission, all children developed an RSV infection of the lower respiratory tract. Chest X-rays (pa-view) of 55 children under, and 53 children over, the age of 6 months (10/53>24 months) were evaluated. The diagnosis of RSV and the chest X-ray were mostly done on the same day. The major radiological findings of the two age-groups were compared by Wilcoxon's unpaired rank sum test. Major radiological findings were: normal chest X-ray (30%), central pneumonia (32%) or peribronchitis (26%). There was no statistical significance between the age-groups. Other findings were emphysema (11%), pleural effusion (6%), lobar- or broncho-pneumonia (each 6%), atelectasis (5%) or pneumothorax in one case. Therefore, the most common radiological findings in RSV-induced infection of the lower respiratory tract, supported by our results (RSV infection without bacterial superinfection) are central pneumonia, peribronchitis or normal chest X-ray. Thus an age-group separation into under or over 6 months is no longer necessary.

[Aspects of donation and processing of stem cell transplants from umbilical cord blood]

BACKGROUND

In 1996, the Institute of Transfusion Medicine and Immunology started the banking of unrelated cord blood (CB) transplants in collaboration with the Department of Gynecology and Obstetrics at the Mannheim University Hospital. Up to now, more than 2000 placental blood samples have been cryopreserved. We analyze the results of CB collection and processing, and describe the legal background of CB collection in Germany.

MATERIALS AND METHODS

CB is only collected with informed consent of the mothers, and without evidence of neither maternal infection nor deformity of the baby. Units with a volume of > 60 ml or > 5 x 10(8) total nucleated cells (NC) are processed as potential transplants. All specimens are evaluated for cell count, HLA typing, sterility testing, ABO/Rh blood groups and clonogenic capacity of hematopoietic progenitor cells. The maternal blood is screened for various infectious disease markers. To reduce the volume of the transplants, we perform buffy coat processing by centrifugation. Finally, we cryopreserve the transplant using a 5.5 percent final concentration of DMSO, and store it in the vapour phase of liquid nitrogen. Results We collected on average 86 +/- 21 ml CB containing 8.87 +/- 3.41 x 10(8) NC (mean +/- SD). 45 percent of the collected units had to be discarded for various reasons. We achieved a mean mononucleated cell recovery by the buffy coat preparation method of 93.4 percent. Defining a threshold dose of 3.0 x 10(7) NC per kg body weight (BW) for transplantation, the mean BW of patients to be sufficiently treated with the stored transplants showed to be 29.6 kg. Conclusions In a very close collaboration between transfusion medicine and obstetricians, a routine collection program for unrelated and related allogeneic CB transplants was established. The CB donation needs to be in accordance with the German drug law. On the other hand, in terms of evidence based medicine, it seems not to be reasonable to collect autologous placental blood for a future transplantation.

Decline in offspring viability as a manifestation of aging in Drosophila melianogaster

The evolutionary explanation of senescence proposes that selection against alleles with deleterious effects manifested only late in life is weak because most individuals die earlier for extrinsic reasons. This argument also applies to alleles whose deleterious effects are nongenetically transmitted from mother to progeny, that is, that affect the performance of progeny produced at late ages rather than of the aging individuals themselves. We studied the effect of maternal age on offspring viability (egg hatching success and larva-to-adult survival) in two sets of Drosophila melanogaster lines (HAM/LAM and YOUNG/OLD), originating from two long-term selection experiments. In each set, some lines (HAM and YOUNG, respectively) have been selected for early reproduction, whereas later reproduction was favored in their counterparts (LAM and OLD). In the HAM and LAM lines, both egg hatching success and larval viability declined with mother's age and did so with accelerating rates. The hatching success declined significantly faster with maternal age in HAM than in LAM lines, according to one of two statistical approaches used. Egg hatching success also declined with maternal age in YOUNG and OLD lines, with no difference between the selection regimes. However, the relationship between mother's age and offspring larva-to-adult viability differed significantly between these two selection regimes: a decline of larval viability with maternal age occurred in YOUNG lines but not in OLD lines. This suggests that the rate with which offspring viability declines with mother's age responded to selection for early versus late reproduction. We suggest broadening the evolutionary concept of senescence to include intrinsically caused declines in offspring quality with maternal age.

Comparison of a continuous glucose-insulin-potassium infusion versus intermittent bolus application of insulin on perioperative glucose control and hormone status in insulin-treated type 2 diabetics

STUDY OBJECTIVE

To compare the effect of two different perioperative insulin management regimes on patients undergoing either major surgery (vascular surgery) or minor surgery (vitrectomy).

DESIGN

Prospective, double-blind randomized trial.

PATIENTS

48 insulin-treated type 2 diabetics aged 18 to 85 years were studied.

SETTING

University medical center.

INTERVENTIONS

Patients were divided into four groups of 12 patients each: Groups A and B (major surgery), Groups C and D (minor surgery). Group A and C patients were treated with a continuous modified glucose-insulin-potassium infusion according to blood glucose levels after intubation. Patients assigned to Groups B and D were treated with intermittent intravenous (IV) insulin injections when glucose levels exceeded 12 mmol L(-1).

MEASUREMENTS

Glucose and potassium levels were measured every 15 minutes and 30 minutes during surgery and up to 4 hours post-surgery. Plasma levels of lactate, cortisol, glycerol, and free fatty acids were measured in arterial samples after intubation (S1), after extubation (S2), and 4 hours after surgery (S3).

MAIN RESULTS

There were no significant differences of the patient characteristics among the four groups. There was no significant difference in the time course of plasma glucose levels and hormone variables measured among the four groups. One episode of hyperglycemia in Group D during the postoperative period was treated with 12 IV units of insulin. One patient in Group A and one in Group B received potassium intraoperatively (15 and 29 mmoL, respectively). Postoperatively, two other patients of Group A received 19 and 12,5 mmoL, respectively, and one of Group B received 20 mmoL potassium.

CONCLUSIONS

Both regimens resulted in relatively stable and comparable blood glucose levels throughout the perioperative period of the minor and major surgeries without differences in metabolic control as measured by levels of lactate, cortisol, glycerol and free fatty acids. Simplicity would favor the intermittent regimen to manage insulin treated type 2 diabetics.

Efficacy and safety of thrombolytic therapy after initially unsuccessful cardiopulmonary resuscitation: a prospective clinical trial

BACKGROUND

During cardiopulmonary resuscitation (CPR), thrombolysis can help to stabilise patients with pulmonary embolism and myocardial infarction. Moreover, thrombolysis during CPR has beneficial effects on cerebral reperfusion after cardiac arrest. We investigated this new therapeutic approach in patients in whom conventional CPR had been unsuccessful.

METHODS

We assessed, in a prospective study, patients undergoing CPR after out-of-hospital cardiac arrest for cardiological reasons in whom return of spontaneous circulation was not achieved within 15 min. According to the Ustein criteria, our control group consisted of patients who were assessed during 1 year. After this year patients were treated with a bolus of 5000 U of heparin and 50mg, over 2 min, of tissue-type plasminogen activator (rt-PA treated group). This intervention was repeated if return of spontaneous circulation was not achieved within the following 30 min. For controls only CPR was given.

FINDINGS

Overall, 90 patients were included; heparin and rt-PA were given to 40 patients. There were no bleeding complications related to the CPR procedures. Of the rt-PA group, 68% (27) had return of spontaneous circulation and 58% (23) were admitted to a cardiac intensive care unit, compared with 44% (22; p=0.026) and 30% (15; p=0.009) of the controls, respectively. At 24 h after cardiac arrest a larger proportion of the rt-PA group than of the controls was alive (35% [14] vs 22% [11], p=0.171), and 15% (six) of rt-PA-treated patients and 8% (four) of controls could be discharged from hospital.

INTERPRETATION

After initially unsuccessful out-of-hospital CPR, thrombolytic therapy combined with heparin is safe and might improve patient outcome. On the basis of our data a randomised controlled trial might be regarded as ethical.