Studies on the relationship of tyrosine hydroxylase, dopamine and cyclic amp-regulated phosphoprotein-32 immunoreactive neuronal structures and d1 receptor antagonist binding sites in various brain regions of the male rat-mismatches indicate a role of d1 receptors in volume transmission

The relationship between tyrosine hydroxylase (TH), dopamine (DA) and cyclic AMP-regulated phosphoprotein-32 (DARPP-32) immunoreactive (IR) neuronal structures and D1 receptor antagonist binding sites has been analysed in various brain regions in the male rat, using immunocytochemistry and receptor autoradiography with the iodinated analogue of SCH 23390 ([(125)I]SCH 23982) as radioligand. Two-colour immunocytochemistry was used to establish in detail the relationship between DARPP-32 and the TH IR neuronal structures in mes-, di- and telencephalon. The analysis reveals complex matches and mismatches between central DARPP-32 immunoreactive neurones, DA neurones and D1 DA receptors. The results inter alia indicate a probable release of DA from the dendritic plexus of the zona reticulata of the substantia nigra to reach D1 DA receptors via extracellular pathways. DA released from the few DA terminals present in the entopeduncular nucleus and from adjacent dopamine axons may also reach D1 DA receptors in this nucleus by extracellular diffusion. A similar situation may also exist in the globus pallidus. Thus, DA may in some regions be released as a paracrine signal to reach distant D1 DA receptors. This type of chemical transmission has been called volume transmission and D1 receptors may thus participate in volume transmission. The mismatch obtained in, for example, the amygdaloid cortex and hypothalamus between D1 receptor antagonist binding sites and DARPP-32 IR nerve cell profiles, is compatible with the possibility that some D1 receptors linked to adenylate cyclase may not involve DARPP-32 as a substrate protein for the cyclic AMP-dependent protein kinase. In addition the possibility should be considered that D1 receptors may not always be linked to adenylate cyclase. Finally, the mismatch in the median eminence between [(125)I]SCH 23982 binding sites and DARPP-32 IR profiles may indicate the existence of D1 receptors which are masked under basal conditions in the male rat.

Entropy generation across Earth's collisionless bow shock

Earth's bow shock is a collisionless shock wave but entropy has never been directly measured across it. The plasma experiments on Cluster and Double Star measure 3D plasma distributions upstream and downstream of the bow shock allowing calculation of Boltzmann's entropy function H and his famous H theorem, dH/dt≤0. The collisionless Boltzmann (Vlasov) equation predicts that the total entropy does not change if the distribution function across the shock becomes nonthermal, but it allows changes in the entropy density. Here, we present the first direct measurements of entropy density changes across Earth's bow shock and show that the results generally support the model of the Vlasov analysis. These observations are a starting point for a more sophisticated analysis that includes 3D computer modeling of collisionless shocks with input from observed particles, waves, and turbulences.

Derivation of the uncontrolled donation after circulatory determination of death protocol for New York city

Evidence from Europe suggests establishing out-of-hospital, uncontrolled donation after circulatory determination of death (UDCDD) protocols has potential to substantially increase organ availability. The study objective was to derive an out-of-hospital UDCDD protocol that would be acceptable to New York City (NYC) residents. Participatory action research and the SEED-SCALE process for social change guided protocol development in NYC from July 2007 to September 2010. A coalition of government officials, subject experts and communities necessary to achieve support was formed. Authorized NY State and NYC government officials and their legal representatives collaboratively investigated how the program could be implemented under current law and regulations. Community stakeholders (secular and religious organizations) were engaged in town hall style meetings. Ethnographic data (meeting minutes, field notes, quantitative surveys) were collected and posted in a collaborative internet environment. Data were analyzed using an iterative coding scheme to discern themes, theoretical constructs and a summary narrative to guide protocol development. A clinically appropriate, ethically sound UDCDD protocol for out-of-hospital settings has been derived. This program is likely to be accepted by NYC residents since the protocol was derived through partnership with government officials, subject experts and community participants.

Second brain death examination may negatively affect organ donation

BACKGROUND

Little is known about the impact of the requirement for a second brain death examination on organ donation. In New York State, 2 examinations 6 hours apart have been recommended by a Department of Health panel.

METHODS

We reviewed data for 1,229 adult and 82 pediatric patients pronounced brain dead in 100 New York hospitals serviced by the New York Organ Donor Network from June 1, 2007, to December 31, 2009. We reviewed the time interval between the 2 clinical brain death examinations and correlated this brain death declaration interval to day of the week, hospital size, and organ donation.

RESULTS

None of the patients declared brain dead were found to regain brainstem function upon repeat examination. The mean brain death declaration interval between the 2 examinations was 19.2 hours. A 26% reduction in brain death examination frequency was seen on weekends when compared to weekdays (p = 0.0018). The mean brain death interval was 19.9 hours for 0-750 bed hospitals compared to 16.0 hours for hospitals with more than 750 beds (p = 0.0015). Consent for organ donation decreased from 57% to 45% as the brain death declaration interval increased. Conversely, refusal of organ donation increased from 23% to 36% as the brain death interval increased. A total of 166 patients (12%) sustained a cardiac arrest between the 2 examinations or after the second examination.

CONCLUSION

A single brain death examination to determine brain death for patients older than 1 year should suffice. In practice, observation time to a second neurologic examination was 3 times longer than the proposed guideline and associated with substantial intensive care unit costs and loss of viable organs.

Occurrence of somatostatin-like immunoreactivity in some peripheral sympathetic noradrenergic neurons

By means of the indirect immunofluorescence technique of Coons and collaborators, somatostatin-like immunoreactivity has been demonstrated in principal ganglion cells of some sympathetic ganglia. The noradrenergic nature of these cells was established by "staining" of the same or consecutive sections with antiserum to dopamine beta-hydroxylase [dopamine beta-monooxygenase; 3,4-dihydroxyphenylethylamine, ascorbate:oxygen oxidoreductase (beta-hydroxylating), EC 1.14.17.1], the enzyme converting dopamine to noradrenaline (norepinephrine). In guinea pigs the somatostatin immunoreactive material was found in almost two-thirds of all principal ganglion cells of the coeliac-superior mesenteric ganglion complex (anterior inferior part) and of the inferior mesenteric ganglion, but only in a few cells of the superior cervical ganglion. It appeared to be localized close to the Golgi complex. The present findings may represent a concomitant storage of a biogenic amine and a small peptide in a neuron. Because both noradrenaline and somatostatin may fulfill a role as a neurotransmitter or modulator, the sympathetic neurons described in this study may represent an example of mammalian nerve cells not conforming to Dale's hypothesis, i.e., the one neuronone transmitter concept.

An MMPI-Based Behavior Descriptor/Personality Trait List

Descriptive terms associated with elevated MMPI scales were abstracted from 10 MMPI reference works. Those corresponding to the 300-word Gough Adjective Check List were retained to construct a new behavior descriptor/personality trait list.

Fibroblast growth factor-21 may mediate growth hormone resistance in anorexia nervosa

CONTEXT

Anorexia nervosa (AN), a state of chronic nutritional deprivation, is characterized by GH resistance with elevated GH levels and decreased levels of IGF-I. Fibroblast growth factor (FGF)-21, a hormone produced in the liver and adipocytes, is induced in the liver by fasting and peroxisome proliferator-activated receptor-alpha agonists. In a transgenic mouse model, FGF-21 reduces IGF-I levels by inhibiting signal transducer and activator of transcription-5, a mediator of the intracellular effects of GH.

OBJECTIVE

The objective of the study was to investigate the relationship between FGF-21, GH, and IGF-I in AN.

DESIGN

This was a cross-sectional study.

SETTING

The study was conducted at a clinical research center.

PATIENTS

Patients included 23 girls: 11 with AN (16.5 +/- 0.6 yr) and 12 normal-weight controls (15.7 +/- 0.5 yr).

INTERVENTIONS

There were no interventions.

MAIN OUTCOME MEASURES

We measured fasting FGF-21, glucose, insulin, IGF-I, and total area under the curve for GH (GH-AUC) and leptin during 12-h overnight frequent sampling.

RESULTS

FGF-21 levels were significantly higher in AN compared with controls, and there was a positive correlation between FGF-21 and GH-AUC (P = 0.03) after controlling for percent body fat and insulin resistance. In subjects with elevated FGF-21 levels, there was a strong inverse association between FGF-21 and IGF-I (R = -0.88, P = 0.004). FGF-21 strongly correlated with total area under the curve for leptin (R = 0.67, P = 0.02).

CONCLUSIONS

FGF-21 levels are higher in AN independent of the effects of percent body fat and insulin resistance. The positive association between FGF-21 and GH-AUC and the inverse association between elevated FGF-21 levels and IGF-I suggests that above the normal range, FGF-21 may mediate a state of GH resistance in AN.

Prehospital 12-Lead ECG: Efficacy or Effectiveness?

INTRODUCTION

Previous literature has documented that prehospital 12-lead electrocardiography (ECG) decreases the time to reperfusion in patients with an acute ST-segment elevation myocardial infarction (STEMI).

OBJECTIVE

To compare time to ECG, time to angioplasty suite (laboratory), and time to reperfusion in emergency medical services (EMS) STEMI patients, who received care through three different processes.

METHODS

The setting was a large suburban community teaching hospital with emergency department (ED)-initiated single-page acute myocardial infarction (AMI) team activation for STEMI patients. The population was STEMI patients transported by EMS from January 2003 to October 2005. Not all EMS agencies had prehospital 12-lead ECG capability. Paramedics interpret and verbally report clinical assessment and ECG findings via radio. The AMI team is activated at the discretion of the emergency physician 1) before patient arrival to the ED based on EMS assessment, 2) after ED evaluation with EMS ECG, or 3) after ED evaluation and ED ECG. Time intervals were calculated from ED arrival. To assess the impact of interventions on performance targets, we also report the proportion of patients who arrived in laboratory within 60 minutes and reperfusion within 90 minutes of arrival. Parametric and nonparametric statistics are used for analysis.

RESULTS

During the study period, there were 164 STEMI patients transported by EMS; mean age was 66.1 years, and 56% were male. Of these, 93 (56.7%) had an EMS ECG and 31 (33%) had AMI team activation before ED arrival. Mean time to laboratory for all patients was 49.8 +/- 34.4 minutes and time to reperfusion was 93.2 +/- 34.5 min. Patients with prearrival activation were transported to laboratory sooner (mean, 24.3 vs. 53. 4 minutes; p < 0.001) and received reperfusion sooner than all other patients (mean, 70.4 vs. 96.3 minutes; p = 0.007). More prearrival activation patients met performance targets to laboratory (96.7% vs. 73.7%; p = 0.009) and reperfusion (85.2% vs. 51.0%; p = 0.003). There was no difference in time to laboratory or to reperfusion for patients who received EMS ECG but no prearrival activation compared with those who received EMS transport alone.

CONCLUSIONS

A minority of patients with EMS ECGs had prearrival AMI team activation. EMS ECGs combined with systems that activate hospital resources, but not EMS ECGs alone, decrease time to laboratory and reperfusion.