Fast neutron activation of ubiquitous materials.

Nuclear explosions expose ubiquitous materials to large numbers of neutrons, producing a variety of radioactive isotopes. To simulate such phenomena from both fission and thermonuclear explosions, we irradiated 29 different targets with approximately 3 and 14 MeV neutrons and measured the beta-delayed gamma rays using germanium detectors. For each neutron energy, the expected radioisotopes, half-lives, and gamma ray energies were deduced. From measurements of the ratios of activities of the radionuclides produced by neutron irradiations, we were able to identify several materials that are particularly sensitive to the neutron energy spectra.

Evidence of anhedonia and differential reward processing in prefrontal cortex among post-withdrawal patients with prescription opiate dependence.

Anhedonia is an important but understudied element of a neuroadaptive model underlying vulnerability to relapse in opioid dependence. Previous research using fMRI has shown reduced activation to pleasant stimuli in rostral prefrontal cortex among heroin-dependent patients in early recovery. This study evaluated the presence of anhedonia among recently withdrawn prescription opiate dependent patients (PODP) in residential treatment compared to control subjects. Anhedonia was assessed using self-report, affect-modulated startle response (AMSR), and a cue reactivity task during which participant's rostral prefrontal cortex (RPFC) and ventrolateral prefrontal cortex (VLPFC) was monitored with functional near infrared spectroscopy (fNIRS). The cue reactivity task included three distinct categories of natural reward stimuli: highly palatable food, positive social situations, and intimate (non-erotic) interactions. PODP reported greater anhedonia on self-report (Snaith-Hamilton Pleasure Scale), and showed reduced hedonic response to positive stimuli in the AMSR task relative to controls. PODP also exhibited reduced neural activation in bilateral RPFC and left VLPFC in response to food images and reduced left VLPFC in response to images depicting positive social situations relative to controls. No differences were found for emotionally intimate stimuli. When patients were divided into groups based on the Snaith-Hamilton criteria for the presence or absence of anhedonia, patients endorsing anhedonia showed reduced neural responses to images depicting positive social stimuli and food relative to patients who did not endorse anhedonia. Activations were in areas of RPFC that support the retrieval of episodic memories. The results suggest the presence of anhedonia in a subsample of PODP.

Pharmacokinetics and pharmacodynamics comparison between subcutaneous and intravenous butorphanol administration in horses.

The study objective was to compare butorphanol pharmacokinetics and physiologic effects following intravenous and subcutaneous administration in horses. Ten adult horses received 0.1 mg/kg butorphanol by either intravenous or subcutaneous injections, in a randomized crossover design. Plasma concentrations of butorphanol were measured at predetermined time points using highly sensitive liquid chromatography-tandem mass spectrometry assay (LC-MS/MS). Demeanor and physiologic variables were recorded. Data were analyzed with multivariate mixed-effect model on ranks (P ≤ 0.05). For subcutaneous injection, absorption half-life and peak plasma concentration of butorphanol were 0.10 ± 0.07 h and 88 ± 37.4 ng/mL (mean ± SD), respectively. Bioavailability was 87%. After intravenous injection, mean ± SD butorphanol steady-state volume of distribution and clearance was 1.2 ± 0.96 L/kg and 0.65 ± 0.20 L/kg/h, respectively. Terminal half-lives for butorphanol were 2.31 ± 1.74 h and 5.29 ± 1.72 h after intravenous and subcutaneous administrations. Subcutaneous butorphanol reached and maintained target plasma concentrations >10 ng/mL for 2 ± 0.87 h (Mean ± SD), with less marked physiologic and behavioral effects compared to intravenous injection. Subcutaneous butorphanol administration is an acceptable alternative to the intravenous route in adult horses.

[Do behavioural problems existing at referral become worse in subsequent years? A study of young persons referred to the outpatient unit of the mental health service]. / Wordt het probleemgedrag bij aanmelding in de loop der jaren erger? Een onderzoek bij jeugdigen verwezen naar de ambulante ggz.

BACKGROUND: Although young persons with severe and complex emotional and behavioural problems are often referred to the outpatient unit of the mental health service, little information is available about whether these problems increase over the years. This information is urgently needed in order to ensure that the mental health service provides adequate care. AIM: To obtain more insight into any increase in young persons' emotional and behavioural problems that may occur over a period of six years following referral to an outpatient unit of the mental health service. METHOD: The nature, severity and complexity of the emotional and behavioural problems of 123 young persons (1999) and of 149 young persons (2005) at the time of the referral - as rated by their parents on the basis of the Child Behavior Checklist (CBCL) - were assessed; the young persons' records were also checked for background characteristics. RESULTS: Compared to 1999, the year 2005 saw a slight decrease in the severity of the problems existing at referral; social problems also declined significantly compared to 1999. Problems identified in the 2005 group often seemed less complex than in 1999. The severity of delinquent behaviour as measured on the Delinquent Behaviour Scale seems to have risen in the 12 to 18 age group in 2005, whereas the severity declined in the 4 to 11-year olds. CONCLUSION: Emotional and behavioural problems as reported by the parents at the time their children were referred to the mental health service do not increase.

Sex differences in the effect of finasteride on acute ethanol withdrawal severity in C57BL/6J and DBA/2J mice.

The neurosteroid allopregnanolone (ALLO) is a potent positive modulator of GABAA receptors that can modulate ethanol (EtOH) withdrawal. The 5alpha-reductase inhibitor finasteride can block the formation of ALLO and other GABAergic neurosteroids and also reduce certain effects of EtOH. Treatment with finasteride during chronic EtOH exposure decreased EtOH withdrawal severity and blood EtOH concentrations (BECs), suggesting an additional effect of finasteride on EtOH pharmacokinetics. Thus, the purpose of the present study was to determine the effect of finasteride on acute EtOH withdrawal severity, to minimize the effect of finasteride on EtOH metabolism. Male and female C57BL/6J and DBA/2J mice received a pretreatment of finasteride (50 mg/kg i.p.) or vehicle 24 h prior to an injection of EtOH (4 g/kg i.p.) or saline. Handling-induced convulsions (HICs) were scored at baseline, and then over a 24 h period after EtOH or saline injection. In another experiment, plasma estradiol and corticosterone levels were assessed at selected time points (0, 2, 8, and 24 h). In a final study, retro-orbital blood samples were collected at 30, 60, 120, and 240 min post-EtOH administration to access finasteride's effects on EtOH clearance parameters. Pretreatment with finasteride increased acute EtOH withdrawal severity in female C57BL/6J and DBA/2J mice but decreased withdrawal severity in male mice of both strains. Finasteride did not alter BECs, EtOH clearance, estradiol, or corticosterone concentrations in a manner that appeared to contribute to the sex difference in finasteride's effect on acute EtOH withdrawal severity. These findings suggest that male and female C57BL/6J and DBA/2J mice differ in their sensitivity to changes in ALLO or other GABAergic neurosteroid levels during acute EtOH withdrawal. Sex differences in the modulation of GABAergic 5alpha-reduced steroids may be an important consideration in understanding and developing therapeutic interventions in alcoholics.

Immunohistochemical assays in prostatic biopsies processed in Bouin's fixative.

AIMS: To investigate the problems involved in undertaking immunohistochemistry (IHC) and nuclear morphometry using Bouin's fixed prostate biopsies. METHODS: Archival Bouin's fixed and formalin fixed, paraffin wax embedded prostatic biopsies were immunostained for three nuclear biomarkers (minichromosome maintenance protein 2 (MCM-2), p27, and Ki-67), one membrane localised biomarker (C-erb-B2), CD34, and alpha methylacyl-CoA racemase (AMACR). The quality of IHC staining was compared between tissues prepared separately in both fixatives. Feulgen staining was also performed on Bouin's fixed tissues to check its suitability for nuclear morphometry. RESULTS: MCM-2 staining was completely negative in Bouin's fixed tissues, whereas p27 showed more background and excess cytoplasmic staining in Bouin's fixed versus formalin fixed tissues. C-erb-B2 showed non-specific, strong luminal cell staining in the Bouin's fixed tissue. Feulgen staining was also very weak in Bouin's fixed tissue. However, Ki-67, AMACR, and CD34 worked equally well in Bouin's and formalin fixed tissues. CONCLUSIONS: Bouin's fixed tissues may be unsuitable when subsequent IHC and morphometry are contemplated. An awareness of which antibodies are suitable for use in Bouin's fixed biopsies is essential.

Effect of calcitonin gene related peptide vs sodium nitroprusside to increase temperature in spontaneous canine tumours during local hyperthermia.

The objectives of this study were to compare the effects of two vasodilators, sodium nitroprusside (SNP) and calcitonin gene-related peptide (CGRP) on mean arterial pressure (MAP), heart rate (HR) and temperatures in tumour and surrounding normal tissue during local hyperthermia treatment. Eleven tumour-bearing pet dogs with spontaneous soft tissue sarcomas were given SNP intravenously during local hyperthermia. The drug infusion rate was adjusted to maintain a 20% decrease in MAP. The median (95% CI) increase in the temperature distribution descriptors T(90) and T(50) was 0.2 degrees C (0.0-0.4 degrees C, p = 0.02) and 0.4 degrees C (0.1-0.7 degrees C, p = 0.02), respectively, in tumour. Normal subcutaneous tissue temperatures were mildly increased but remained below the threshold for thermal injury. The effects of CGRP were investigated in six tumour-bearing dogs following a protocol similar to that used for SNP. The median (interquartile (IQ) range) decrease in mean arterial pressure was 19% (15-26%) after CGRP administration and a significant increase was seen in tumour but not normal subcutaneous tissue temperatures. The median (95% CI) increase in the temperature distribution descriptors T(90) and T(50) was 0.5 degrees C (0.1-1.6 degrees C, p = 0.03) and 0.8 degrees C (0.1-1.6 degrees C, p = 0.13), respectively. Administration of SNP or CGRP did not result in local or systemic toxicity in tumour-bearing dogs. However, the magnitude of increase in tumour temperatures was not sufficient to improve the likelihood of increased response rates. Therefore, there is little justification for translation of this approach to human trials using conventional local hyperthermia.

Finding paradigms for the future of alcoholism research: an interdisciplinary perspective.

This is a review article and critique of current research strategies in the alcohol field. Although the alcohol field is proud of its multidisciplinary tradition and scientific findings within specific disciplines, there are very few models of cross-disciplinary research and communication. Currently, the favored model of risk is genetic; the favored model of pathophysiology is molecular neuroscience; and the favored model of clinical investigation is narrowly categorical. If there is a hierarchy within science that is based on explanatory power, then models of alcoholism emerging from neuroscience, molecular biology, and genetics should be able to accommodate (if not account for) the findings on clinical aspects of alcohol dependence, as well as data on differential risk, course, and recovery that come from the behavioral and social sciences. The first section of this article reviews the most popular models of alcohol dependence over the past 40 years. I argue that the currently fashionable categorical approach to diagnosis in DSM-IV (and ICD-10) has failed to serve as a framework for interdisciplinary research and has failed to meet the needs of human geneticists, population-based researchers, psychosocial researchers, basic scientists working in animal models, and patient-oriented researchers. I argue for a return to the dimensional approach to diagnosis in the alcohol dependence syndrome construct. In the second section of the article, I lay out an agenda for revitalized patient-oriented research in the alcohol field, as a bridge between basic biological research and innovations in clinical practice, as well as the key to a valid diagnostic system that can inform research strategies in genetics and population-based research. In the third section of the article, I highlight the interface between genetic and psychosocial models of risk and propose a possible structure for future collaboration. I conclude with a plea to funding agencies and investigators to translate discipline-based scientific findings into a science relevant to alcoholism by addressing the challenges and opportunities of an interdisciplinary research agenda on the pathophysiology of alcohol dependence and the multidimensional sources of risk.

Craving: what can be done to bring the insights of neuroscience, behavioral science and clinical science into synchrony.

Alcohol self-administration behavior is the common thread that is necessary to bring the insights of neuroscience, behavioral science and clinical science into synchrony around the concept of craving. Animal models should address the molecular and cellular changes that take place in behaviorally relevant brain regions of rats consequent to chronic self-administration of ethanol. Animal models can focus on the biology of the anticipatory state in alcohol preferring/consuming rats, as well as studies of the effects of possible medications on this state in the animal model, on actual alcohol consuming behavior, and on the residual effects of chronic alcohol on the non-human mammalian brain. In human studies of craving, cue-reactivity in the absence of the opportunity to drink alcohol does not have the same salience as cue-reactivity in which drinking is possible. Moreover, actual drinking behavior serves to validate self-reports of craving. Studies of limited alcohol self-administration in the laboratory are an essential element in screening new medications for the treatment of alcoholism. Studies to date suggest no adverse reaction to the participation of alcoholic subjects in limited alcohol self-administration studies, but the research community should continue to monitor carefully the outcomes of alcohol-dependent subjects who participate in this type of research, and efforts should always be made to encourage these subjects to enter active treatment. In outpatient clinical trials of new treatments for alcoholism, the assessment of craving should include queries regarding symptoms and signs of protracted abstinence such as sleep disturbances, as well as questions regarding situational craving. Field observations of alcoholics in their favorite drinking environments would contribute greatly to our understanding of the real-world phenomenology of craving.

Local 42 degrees C hyperthermia improves vascular conductance of the R3230Ac rat mammary adenocarcinoma during sodium nitroprusside infusion.

The effect of sodium nitroprusside-induced hypotension on the perfusion of the R3230 adenocarcinoma during local 42 degrees C hyperthermia was studied using a combination of intravital microscopy and laser Doppler flowmetry. Fischer 344 rats were implanted with dorsal skin flap window chambers containing the R3230Ac tumor and allocated to three treatment groups (34 degrees C with nitroprusside, 42 degrees C with nitroprusside, and 42 degrees C with 0.9% saline). After baseline observation at 34 degrees C, tumors were locally heated to 42 degrees C using a water bath and either 0.9% saline or nitroprusside sufficient to reduce blood pressure 20% below pretreatment baseline was infused. Nitroprusside at 34 degrees C decreased tumor vascular conductance 40% with no effect on the diameter of arterioles entering the tumor. The diameter of arterioles entering 42 degrees C heated tumors increased 35% independent of blood pressure change. Saline at 42 degrees C had no effect on tumor vascular conductance; however, nitroprusside at 42 degrees C increased tumor vascular conductance 55%. Local 42 degrees C tumor heating, combined with a moderate reduction in blood pressure with nitroprusside, overrides the vascular steal effect associated with reduced perfusion pressure alone and results in improved tumor perfusion. Observations of the effect of vasodilator substances on normothermic tumor perfusion cannot be extrapolated to situations where moderate hyperthermia is used.

Temperature-dependent changes in physiologic parameters of spontaneous canine soft tissue sarcomas after combined radiotherapy and hyperthermia treatment.

PURPOSE: The objectives of this study were to evaluate effects of hyperthermia on tumor oxygenation, extracellular pH (pHe), and blood flow in 13 dogs with spontaneous soft tissue sarcomas prior to and after local hyperthermia. METHODS AND MATERIALS: Tumor pO2 was measured using an Eppendorf polarographic device, pHe using interstitial electrodes, and blood flow using contrast-enhanced magnetic resonance imaging (MRI). RESULTS: There was an overall improvement in tumor oxygenation observed as an increase in median pO2 and decrease in hypoxic fraction (% of pO2 measurements <5 mm Hg) at 24-h post hyperthermia. These changes were most pronounced when the median temperature (T50) during hyperthermia treatment was less than 44 degrees C. Tumors with T50 > 44 degrees C were characterized by a decrease in median PO2 and an increase in hypoxic fraction. Similar thermal dose-related changes were observed in tumor perfusion. Perfusion was significantly higher after hyperthermia. Increases in perfusion were most evident in tumors with T50 < 44 degrees C. With T50 > 44 degrees C, there was no change in perfusion after hyperthermia. On average, pHe values declined in all animals after hyperthermia, with the greatest reduction seen for larger T50 values. CONCLUSION: This study suggests that hyperthermia has biphasic effects on tumor physiologic parameters. Lower temperatures tend to favor improved perfusion and oxygenation, whereas higher temperatures are more likely to cause vascular damage, thus leading to greater hypoxia. While it has long been recognized that such effects occur in rodent tumors, this is the first report to tie such changes to temperatures achieved during hyperthermia in the clinical setting. Furthermore, it suggests that the thermal threshold for vascular damage is higher in spontaneous tumors than in more rapidly growing rodent tumors.

Acute pancreatitis associated with administration of a nitric oxide synthase inhibitor in tumor-bearing dogs.

BACKGROUND: Nitric oxide synthase (NOS) inhibitors have been investigated as potential cytotoxic agents to treat tumors lacking p53 function. Furthermore, their ability to reduce tumor blood flow can be combined with drugs that are specifically designed to kill cells that are hypoxic or to improve temperatures during local heat (hyperthermia) treatment of tumors. This paper reports the unexpected development of acute pancreatitis in two tumor-bearing pet dogs that were treated with the NOS inhibitor, NG-nitro-L-arginine methyl ester (L-NAME) during administration of local hyperthermia. METHODS: Prior to the use of L-NAME in tumor-bearing dogs, purpose-bred beagles were studied. Following induction of inhalation anesthesia, local hyperthermia was applied to either normal thigh muscle (beagles) or tumors (tumor-bearing dogs). Once a thermal steady state was achieved, L-NAME was administered and temperature monitoring continued. Animals were observed after treatment for evidence of toxicity. RESULTS: The beagles tolerated the treatment well, with no side effects noted either clinically or by routine CBC or blood chemistry analyses. In contrast, the first two tumor-bearing dogs accrued onto the phase I study developed acute pancreatitis in the immediate post-treatment period which necessitated hospitalization and intensive care. The trial was stopped. Both dogs had intercurrent risk factors which predisposed them to development of pancreatitis, although neither had a history of symptoms of pancreatitis at the time the hyperthermia + L-NAME treatment was given. CONCLUSIONS: We conclude that caution should be exercised when considering NOS inhibition for cancer treatment. Careful evaluation of history and health status as well as recognition of potential risk factors may be key in avoiding potentially fatal complications. This study demonstrates the value of performing potentially harmful treatments in tumor-bearing dogs prior to introduction into the human clinic.