Pain in alcohol use disorder: Evaluating effects of childhood trauma, perceived stress, and psychological comorbidity.

The relationship between pain and alcohol use disorder (AUD) is complex and bidirectional. The current study examines risk factors for pain in a large comprehensively phenotyped sample including individuals from across the spectrum of alcohol use and misuse. Participants (n = 1101) were drawn from the National Institute on Alcohol Abuse and Alcoholism Natural History Protocol and included treatment-seeking AUD inpatients (AUD+Tx, n = 369), individuals with AUD not seeking treatment (AUD+, n = 161), and individuals without AUD (AUD-, n = 571). General linear models were utilized to test the effects of AUD status, history of childhood trauma exposure, perceived stress, and psychological comorbidity on daily percent time in pain, as well as change in daily percent time in pain across the inpatient stay in AUD+Tx individuals. Overall, 60.2% individuals reported any pain, with a significantly higher prevalence in the AUD+Tx group (82.1%) compared to the AUD+ (56.5%) and AUD- (47.1%) groups. Daily percent time in pain was also highest in the AUD+Tx group (30.2%) and was further increased in those with a history of childhood abuse and comorbid posttraumatic stress disorder (PTSD). Years of heavy drinking and craving were also associated with increased percent time in pain in the AUD+Tx group. Percent time in pain decreased following acute withdrawal in the AUD+Tx group but plateaued around 25% just prior to discharge. Individuals seeking inpatient treatment for AUD, especially those with a history of childhood trauma and/or comorbid PTSD, report greater percent time in pain compared to those not seeking treatment and those without AUD. The prolonged experience of pain in abstinent AUD inpatients after the resolution of acute withdrawal may signal the early stages of protracted withdrawal. Integrative treatments targeting pain and other symptoms of protracted withdrawal may be effective in improving overall function in people with severe AUD.

Elevated stearoyl-CoA desaturase 1 activity is associated with alcohol-associated liver disease.

Chronic binge drinking induces hepatic lipid accumulation, but only certain individuals develop alcohol-associated liver disease (ALD). Specific patterns of lipid accumulation are thought to be associated with ALD, but this has not been comprehensively investigated to date. We analyzed plasma fatty acid levels, quantified by gas chromatography-mass spectrometry, in a sample of patients with alcohol use disorder (AUD). Given that elevation in serum alanine transaminase (ALT) levels are strongly associated with ALD, patients were stratified into two groups based on ALT levels: an ALD group (ALT >40 IU/L) and a non-ALD group (ALT ≤40 IU/L). There was a shift toward greater concentrations of monounsaturated fatty acids in the ALD group compared to the non-ALD group. Stearoyl-CoA desaturase (SCD1) activity in the ALD group was then estimated as the ratio of palmitoleic acid (16:1) to palmitic acid (16:0). SCD1 activity was greater in the ALD than the non-ALD group. A series of linear regression models demonstrated that SCD1 activity mediated the association between binge drinking and ALD. These findings provide initial evidence that SCD1 activity may be associated with ALD. If validated prospectively, elevated SCD1 activity could potentially be used as a biomarker to identify individuals at high risk for developing ALD.

Effects of manufactured nanomaterials on fishes: a target organ and body systems physiology approach.

Manufactured nanomaterials (NM) are already used in consumer products and exposure modelling predicts releases of ng to low µg l(-1) levels of NMs into surface waters. The exposure of aquatic ecosystems, and therefore fishes, to manufactured NMs is inevitable. This review uses a physiological approach to describe the known effects of NMs on the body systems of fishes and to identify the internal target organs, as well as outline aspects of colloid chemistry relevant to fish biology. The acute toxicity data, suggest that the lethal concentration for many NMs is in the mg l(-1) range, and a number of sublethal effects have been reported at concentrations from c. 100 µg to 1 mg l(-1). Exposure to NMs in the water column can cause respiratory toxicity involving altered ventilation, mucus secretion and gill pathology. This may not lead, however, to overt haematological disturbances in the short term. The internal target organs include the liver, spleen and haematopoietic system, kidney, gut and brain; with toxic effects involving oxidative stress, ionoregulatory disturbances and organ pathologies. Some pathology appears to be novel for NMs, such as vascular injury in the brain of rainbow trout Oncorhynchus mykiss with carbon nanotubes. A lack of analytical methods, however, has prevented the reporting of NM concentrations in fish tissues, and the precise uptake mechanisms across the gill or gut are yet to be elucidated. The few dietary exposure studies conducted show no effects on growth or food intake at 10-100 mg kg(-1) inclusions of NMs in the diet of O. mykiss, but there are biochemical disturbances. Early life stages are sensitive to NMs with reports of lethal toxicity and developmental defects. There are many data gaps, however, including how water quality alters physiological responses, effects on immunity and chronic exposure data at environmentally relevant concentrations. Overall, the data so far suggest that the manufactured NMs are not as toxic as some traditional chemicals (e.g. some dissolved metals) and the innovative, responsible, development of nanotechnology should continue, with potential benefits for aquaculture, fisheries and fish health diagnostics.

Concentrations of oxidized linoleic acid derived lipid mediators in the amygdala and periaqueductal grey are reduced in a mouse model of chronic inflammatory pain.

Chronic pain is both a global public health concern and a serious source of personal suffering for which current treatments have limited efficacy. Recently, oxylipins derived from linoleic acid (LA), the most abundantly consumed polyunsaturated fatty acid in the modern diet, have been implicated as mediators of pain in the periphery and spinal cord. However, oxidized linoleic acid derived mediators (OXLAMs) remain understudied in the brain, particularly during pain states. In this study, we employed a mouse model of chronic inflammatory pain followed by a targeted lipidomic analysis of the animals' amygdala and periaqueductal grey (PAG) using LC-MS/MS to investigate the effect of chronic inflammatory pain on oxylipin concentrations in these two brain nuclei known to participate in pain sensation and perception. From punch biopsies of these brain nuclei, we detected twelve OXLAMs in both the PAG and amygdala and one arachidonic acid derived mediator, 15-HETE, in the amygdala only. In the amygdala, we observed an overall decrease in the concentration of the majority of OXLAMs detected, while in the PAG the concentrations of only the epoxide LA derived mediators, 9,10-EpOME and 12,13-EpOME, and one trihydroxy LA derived mediator, 9,10,11-TriHOME, were reduced. This data provides the first evidence that OXLAM concentrations in the brain are affected by chronic pain, suggesting that OXLAMs may be relevant to pain signaling and adaptation to chronic pain in pain circuits in the brain and that the current view of OXLAMs in nociception derived from studies in the periphery is incomplete.

Perioperative immunotherapy with recombinant interleukin 2 in patients undergoing surgery for colorectal cancer.

Major surgery impairs the cellular immune response. We have therefore studied the immunological effects of low-dose recombinant interleukin 2 given to patients undergoing surgery for colorectal cancer to determine whether this agent has potential in perioperative adjuvant immunotherapy. Patients were randomly allocated to control (n = 13) or treatment groups (n = 12). Immunological studies of both lymphocyte function and subset number were performed preoperatively and on Days 1, 4, 7, and 10. Treatment with recombinant interleukin 2 prevented the postoperative fall in both natural killer and lymphokine-activated killer cell cytotoxicity, clearly demonstrated in the control group. The treatment group also showed in vivo T-cell activation with an initial lymphopenia followed by a rebound lymphocytosis and upregulation of the subset markers CD25 (interleukin 2 receptor) and CD45RO (T-memory cells). These combined effects may have important consequences in controlling metastatic dissemination of tumor during the vulnerable perioperative period.

Velocity and attenuation of sound in the isolated fetal lung as it is expanded with air.

We measured the velocity and attenuation of audible sound in the isolated lung of the near-term fetal sheep to test the hypothesis that the acoustic properties of the lung provide a measure of the volume of gas it contains. We introduced pseudorandom noise (bandwidth 70 Hz-7 kHz) to one side of the lung and recorded the noise transmitted to the surface immediately opposite, starting with the lung containing only fetal lung liquid and making measurements after stepwise inflation with air until a leak developed. The velocity of sound in the lung fell rapidly from 187 +/- 28.2 to 87 +/- 3.7 m/s as lung density fell from 0.93 +/- 0.01 to 0.75 +/- 0.01 g/ml (lung density = lung weight/gas volume plus lung tissue volume). For technical reasons, no estimate of velocity could be made before the first air injection. Thereafter, as lung density fell to 0.35 +/- 0.01 g/ml, there was a further decline in velocity to 69.6 +/- 4.6 m/s. High-frequency sound was attenuated as lung density decreased from 1.0 to 0.5 g/ml, with little change thereafter down to a density of 0.35 +/- 0.01 g/ml. We conclude that both the velocity of audible sound through the lung and the degree to which high-frequency sound is attenuated in the lung provide information on the degree of inflation of the isolated fetal lung, particularly at high lung densities. If studies of sound transmission through the lung in the intact organism were to confirm these findings, the acoustic properties of the lung could provide a means for monitoring lung aeration during mechanical ventilation of newborn infants.

The effect of modifying dietary LA and ALA intakes on omega-3 long chain polyunsaturated fatty acid (n-3 LCPUFA) status in human adults: a systematic review and commentary.

This paper presents a systematic review of human studies investigating the effect of altering dietary omega-3 polyunsaturated fatty acid (n-3 PUFA) alpha-linolenic acid (ALA) and omega-6 polyunsaturated fatty acid (n-6 PUFA) linoleic acid (LA) intakes on n-3 long-chain polyunsaturated fatty acid (LCPUFA) status in adult humans. The results suggest that it is possible to increase n-3 LCPUFA status by reducing LA and/or increasing ALA intake in humans, although decreasing LA intake to below 2.5%E may be required to specifically increase levels of the n-3 LCPUFA docosahexaenoic acid (DHA). The majority of studies in this area to date have been relatively poor in quality, which limits the ability to draw robust conclusions, and we present a series of recommendations to improve the quality of future studies in fatty acid nutrition in humans.

Affinity isolation of imidazoline binding proteins from rat brain using 5-amino-efaroxan as a ligand.

We have employed an amino derivative of the imidazoline ligand, efaroxan, to isolate imidazoline binding proteins from solubilised extracts of rat brain, by affinity chromatography. A number of proteins were specifically retained on the affinity column and one of these was immunoreactive with an antiserum raised against the ion conducting pore component of the ATP-sensitive potassium channel. Patch clamp experiments confirmed that, like its parent compound, amino-efaroxan blocks ATP-sensitive potassium channels in human pancreatic beta-cells and can stimulate the insulin secretion from these cells. The results reveal that a member of the ion conducting pore component family is strongly associated with imidazoline binding proteins in brain and in the endocrine pancreas.

Melanogenesis-targeted anti-melanoma pro-drug development: effect of side-chain variations on the cytotoxicity of tyrosinase-generated ortho-quinones in a model screening system.

A set of 26 substituted phenols, 10 of which were synthesised in our laboratories, were tested for their rate of oxidation by mushroom tyrosinase in vitro as determined by oximetry and spectrophotometry and for their cytotoxic action in a model system. With one exception (4-hydroxybenzoic acid) all the agents tested were oxidised to the corresponding ortho-quinones. The maximum rates of oxidation varied between 15.1 +/- 0.59 nmoles oxygen consumed per minute (4-(2-thioethylthio)phenol) and 372.9 +/- 5.61 nmoles O2/ min. (4-(2-Hydroxyethylthio)phenol) in a reaction system comprising 300 units tyrosinase and 200 microM substrate. The rates of generation of quinone were in close agreement with these oximetric data. Some anomalies in oxygen stoichiometry were observed due to reoxidation of reaction products. Four categories of compounds were tested: those known to undergo side-chain cyclisation (such as tyrosine) (Group A), alkylphenols of increasing chain length with or without terminal hydroxyl groups (Group B), compounds with charged or bulky side-chains (Group C) and agents with oxy-, thio- and selenyl-ether side-chains (Groups D, E and F). In the majority of cases, the cytotoxicity, measured by the reduction of thymidine incorporation in cells exposed for 30 min to the agent in the presence of tyrosinase, reflected the rate of oxidation and is ascribed to the toxic action of the derived ortho-quinone. Tyrosinase-dependent cytotoxicity was absent in cyclising (Group A) and in Group C compounds. Toxicity, expressed by comparison with 4-hydroxyanisole (4HA) (IC50 = 11.7 microM), ranged between 0.36 (4-hydroxybenzyl alcohol) and 1.07 (3-(4-hydroxyphenyl)propanol) for Group B compounds, and be-tween 0.83 (4-ethoxyphenol) and 2.08 (4-(2-hydroxyethylthio)phenol) for groups D, E and F. Addition of glutathione to the toxicity assay system abrogated the cytotoxic action and, on the basis of spectrophotometric data, this is ascribed to the prevention of cellular thiol depletion by the ortho-quinone products of tyrosinase oxidation of the phenolic substrates. The lack of toxicity of the group C compounds may be due to the inability of their derived quinones to gain access to the cells. Addition of catalase or deferoxamine to the incubation medium was without effect on tyrosinase-dependent toxicity.

Synthesis and quantitative structure-activity relationships of antiallergic 2-hydroxy-N-1H-tetrazol-5-ylbenzamides and N-(2-hydroxyphenyl)-1H-tetrazole-5-carboxamides.

The synthesis and antiallergic activity of a series of 2-hydroxy-N-1H-tetrazol-5-ylbenzamides and isomeric N-(2-hydroxyphenyl)-1H-tetrazole-5-carboxamides is described. A relationship between structure and intravenous antiallergic activity in the rat passive cutaneous anaphylaxis (PCA) test has been established using a Hansch/Free-Wilson model and used to direct studies toward potent derivatives. The contribution of physicochemical properties to activity is discussed. One member of this series, N-(3-acetyl-5-fluoro-2-hydroxyphenyl)-1H-tetrazole-5-carboxamide (3f), which was selected for further evaluation, has an ID50 value of 0.16 mg/kg po and is 130 times more potent than disodium cromoglycate (DSCG) on intravenous administration.

The response to interferon of NK and K cells from conventionally immunosuppressed and cyclosporine-treated renal allograft recipients.

Interferon is a potent stimulator of natural killer (NK) and killer (K) cell activity in human beings, both these cytotoxic functions representing host defense mechanisms against viral infections and lymphoid malignancy. Both NK and K cell functions are markedly impaired in conventionally immunosuppressed allograft recipients but coincubation of lymphocytes from these patients with purified human lymphoblastoid interferon considerably augments both these activities. Cyclosporine immunosuppression causes only a moderate, but significant, impairment of NK activity--but K cell activity appears to be normal. Again IFN increases NK activity of the lymphocytes of these patients but produces a fall or only moderate increases in K cell activity. We conclude that these data support the functional distinction between NK and K cells and suggest that immunosuppressive agents act at the pre-NK/K cell stage of maturation, though possibly via different mechanisms.

Changes in human natural killer activity early and late ater renal transplantation using conventional immunosuppression.

The natural killer (NK) cell activity of human peripheral blood lymphocytes falls following major surgical procedures including renal transplantation but in non-immunosuppressed individuals returns to normal levels within the first 72 hr after operation. In renal allograft recipients, if this early postoperative fall is excluded from the analysis, NK cell function appears to follow changes in allograft function, suggesting that in vivo, as has been reported in vitro, NK activity is generated during activation of the alloreactive process. In an additional group of patients whose grafts were functioning for between 3 and 102 months after cadaveric renal transplantation using conventional immunosuppression, NK function was depressed in comparison with that of control subjects. However, some patients who were more than 48 months post-transplant had normal NK cell activity. Collectively, these results suggest that NK cell function may recover despite the continued administration of conventional immunosuppressive agents.

Imidazolines and pancreatic hormone secretion.

A range of imidazoline derivatives are known to be effective stimulators of insulin secretion, and this response correlates with closure of ATP-sensitive potassium channels in the pancreatic beta-cell. However, mounting evidence indicates that potassium channel blockade may form only part of the mechanism by which imidazolines exert their effects on insulin secretion. Additionally, it remains unclear whether members of this class of drugs can bind directly to potassium channel components and whether occupation of a single binding site accounts for their functional activity. This review considers recent developments in the field and highlights evidence that does not fit readily with the concept that a single mechanism of action is sufficient to mediate the effects of imidazolines on pancreatic hormone secretion.

Dibutyryl cAMP induces a gestation-dependent absorption of fetal lung liquid.

The maturation of the adenosine 3',5'-cyclic monophosphate-(cAMP) dependent pathway controlling fetal lung liquid secretion was examined in experiments in which the lungs of chronically catheterized fetal lambs (123-141 days gestational age) were exposed to dibutyryl cAMP (DBcAMP, 10(-4) M). The effect of DBcAMP was markedly gestation dependent, with the greatest effect observed in the most mature fetuses. In immature fetuses (less than 130 days, mean age 125 days) DBcAMP caused slowing of secretion, with maximal effect at 5 h. With increasing maturity the effect of DBcAMP was more pronounced and occurred earlier so that in mature fetuses (mean age 140 days) lung liquid absorption took place, with maximal effect at 2 h. Changes in lung liquid volume flow induced by DBcAMP could be blocked by addition of 10(-4) M amiloride to lung liquid. It is concluded that 1) DBcAMP induces a change in lung liquid secretion that, like epinephrine, is mediated via an increase in Na+ permeability of the apical membrane of the lung epithelium and 2) the rate-limiting step in the maturation of this process must lie beyond the generation of intracellular cAMP.

Effect of I/E ratio on mean alveolar pressure during high-frequency oscillatory ventilation.

This study investigated factors contributing to differences between mean alveolar pressure (PA) and mean pressure at the airway opening (Pao) during high-frequency oscillatory ventilation (HFOV). The effect of the inspiratory-to-expiratory time (I/E) ratio and amplitude of oscillation on the magnitude of - Pao (Pdiff) was examined by using the alveolar capsule technique in normal rabbit lungs (n = 4) and an in vitro lung model. The effect of ventilator frequency and endotracheal tube (ETT) diameter on Pdiff was further examined in the in vitro lung model at an I/E ratio of 1:2. In both lung models, fell below Pao during HFOV when inspiratory time was shorter than expiratory time. Under these conditions, differences between inspiratory and expiratory flows, combined with the nonlinear relationship between resistive pressure drop and flow in the ETT, are the principal determinants of Pdiff. In our experiments, the magnitude of Pdiff at each combination of I/E, frequency, lung compliance, and ETT resistance could be predicted from the difference between the mean squared inspiratory and expiratory velocities in the ETT. These observations provide an explanation for the measured differences in mean pressure between the airway opening and the alveoli during HFOV and will assist in the development of optimal strategies for the clinical application of this technique.

Errors in estimating lung liquid volume in fetal lambs when using radiolabeled serum albumin and blue dextran.

Fetal lung liquid volume is usually determined by using radio-iodinated serum albumin (RISA) or blue dextran (BD) as volume tracers. We tested the reliability of both tracers at 124 (G124) and 142 days of gestation (G142; term = G147) when the labels were employed simultaneously. We measured the proportion of label bound reversibly to the lung, or apparently lost from the lung compartment, by washing out the lung with saline and 5% albumin. At G124, volume estimates with the two labels were similar. At G142, the volume estimate with BD (36.3 +/- 8.7 ml/kg of body wt) was higher (P < 0. 05) than with RISA (22.3 +/- 3.5 ml/kg). This difference resulted from reversible binding of BD, because 5% albumin washout released 38.5 +/- 4.0% of the BD added at the start of the experiment but a lesser amount of RISA (9.8 +/- 0.7%; P < 0.05). At G142, when RISA was used alone, its reversible binding was 1.3 +/- 0.2%. Background absorbance increased during experiments, giving rise to an apparent increase in BD concentration. We conclude that RISA is an effective tracer for lung liquid volume determination in the fetal lamb, whereas our findings of substantial epithelial binding of BD and large changes in background absorbance demonstrate that, under the conditions of our experiments, BD is a poor tracer close to term.

Interleukin-10. A role in the development of postoperative immunosuppression.

BACKGROUND: The cause of diminished monocyte major histocompatibility complex class II antigen expression after surgery or trauma is unclear. Interleukin-10 (IL-10) regulates inflammatory cytokine production and major histocompatibility complex class II (HLA-DR) expression in vitro. OBJECTIVES: To quantify in vivo IL-10 messenger RNA (mRNA) and protein and monocyte HLA-DR expression after major surgery and to investigate the effects of IL-10 neutralizing blockade on monocyte HLA-DR expression in vitro. DESIGN: Inception cohort study of 48 surgical patients from preoperative status to postoperative day 7 and 9 healthy volunteers (controls). SETTING: Large teaching hospital, Northern England. PATIENTS: Monocyte HLA-DR and cytokine mRNA expression was determined in 32 of 48 consecutive patients undergoing elective major resectional surgery. Mononuclear cells for in vitro studies and serum samples for IL-10 measurement were obtained from the remaining 16 patients. MAIN OUTCOME MEASURES: Monocyte HLA-DR expression determined by flow cytometry, IL-10, and tumor necrosis factor mRNA in peripheral blood mononuclear cells assayed by multiplex reverse transcriptase polymerase chain reaction, and serum IL-10 determined by enzyme-linked immunosorbent assay. RESULTS: Monocyte HLA-DR expression (in mean channel fluorescence units [MCF]) was significantly reduced 24 hours after surgery (MCF [+/- SEM], 32.6 +/- 2.3 vs 16.3 +/- 1.2; P < .001) and remained low during the first postoperative week. A relative increase in IL-10 to G3PDH mRNA ratio (mean [+/- SEM], 0.95 +/- 0.08 vs 0.59 +/- 0.06; P < .01) and serum IL-10 (mean [+/- SEM], 18.1 +/- 4.1 vs 5.4 +/- 0.8 pg/mL; P < .01) was noted on the first postoperative day. A significant correlation existed between HLA-DR antigen expression and the presence of IL-10 mRNA transcript on the first postoperative day (P < .01). Lipopolysaccharide-induced up-regulation of monocyte HLA-DR expression was significantly impaired on the first postoperative day (mean [+/- SEM], 151% +/- 24.4% vs 60% +/- 10.1%; P < .01), but this was partially reversed by IL-10 neutralizing antibody (mean [+/- SEM], 60% +/- 10.1% vs 115% +/- 11.6%; P < .01). CONCLUSIONS: Interleukin-10 gene expression correlates with the fall in monocyte HLA-DR antigen expression in patients undergoing major abdominal surgery and may account for the immunosuppression associated with surgical injury.

Evidence that the ability of imidazoline compounds to stimulate insulin secretion is not due to interaction with sigma receptors.

Recent studies have suggested that a variety of ion channels possess a binding site for ligands such as phencyclidine (PCP), dizocilpine and certain sigma ligands and that some imidazoline compounds can also bind to this site. We have investigated whether interaction with this binding site could account for the ability of imidazolines to stimulate insulin secretion from rat islets. Neither PCP nor dizocilpine shared the insulin secretory activity of the imidazoline efaroxan in rat islets suggesting that they do not have similar actions in the pancreatic B-cell. Further, we were able to define a new antagonist, KU14R (2(2-ethyl 2,3-dihydro-2-benzofuranyl)-2-imidazole), which selectively blocks the insulin secretory response to imidazolines. The results suggest that imidazolines do not stimulate insulin secretion by causing physical blockade of the K(+)-ATP channel in pancreatic B-cells and show that their effects are not reproduced by PCP or sigma receptor ligands.

Characterisation of new efaroxan derivatives for use in purification of imidazoline-binding sites.

The insulin secretagogue activity of certain imidazoline compounds is mediated by a binding site associated with ATP-sensitive K+ (K(ATP)) channels in the pancreatic beta-cell. We describe the effects of a series of structural modifications to efaroxan on its activity at this site. Substitution of amino-, nitro- or azide- groups onto the 5-position of the benzene ring of efaroxan did not significantly affect the functional interaction of the ligand with the islet imidazoline binding site. Modification of the imidazoline ring to an imidazole to generate 2-(2-ethyl-2,3-dihydrobenzo[b]furan-2-yl)-1H-imidazole (KU14R) resulted in loss of secretagogue activity. Indeed, this reagent appeared to act as an imidazoline antagonist since it blocked the secretory responses to imidazoline compounds and also inhibited the blockade of beta-cell K(ATP) channels by efaroxan in patch clamp experiments. Application of KU14R alone resulted in a modest reduction in K(ATP) channel opening, suggesting that it may display weak partial agonism, at least in patch-clamp experiments.