Intrathecal phospholipase A2 (PLA2) and cyclooxygenase-2 (COX-2), but not COX-1, inhibitors attenuate facilitated pain states generated by peripheral injury/inflammation and by direct activation of spinal glutamate and substance P receptors. These results are consistent with the constitutive expression of PLA2 and COX-2 in spinal cord, the spinal release of prostaglandins by persistent afferent input, and the effects of prostaglandins on spinal excitability. Whereas the acute actions of COX-2 inhibitors are clearly mediated by constitutively expressed spinal COX-2, studies of spinal COX-2 expression indicate that it is upregulated by neural input and circulating cytokines. Given the intrathecal potency of COX-2 inhibitors, the comparable efficacy of intrathecal versus systemic COX-2 inhibitors in hyperalgesic states not associated with inflammation, and the onset of antihyperalgesic activity prior to COX-2 upregulation, it is argued that a principal antihyperalgesic mechanism of COX-2 inhibitors lies with modulation of constitutive COX-2 present at the spinal level.

Western blots show the constitutive expression of COX-1 and COX-2 in the rat spinal dorsal and ventral horns and in the dorsal root ganglia. Using selective inhibitors of cyclooxygenase (COX) isozymes, we show that in rats with chronic indwelling intrathecal catheters the acute thermal hyperalgesia evoked by the spinal delivery of substance P (SP; 20 nmol) or NMDA (2 nmol) and the thermal hyperalgesia induced by the injection of carrageenan into the paw are suppressed by intrathecal and systemic COX-2 inhibitors. The intrathecal effects are dose-dependent and stereospecific. In contrast, a COX-1 inhibitor given systemically, but not spinally, reduced carrageenan-evoked thermal hyperalgesia but had no effect by any route with spinal SP hyperalgesia. Using intrathecal loop dialysis catheters, we showed that intrathecal SP would enhance the release of prostaglandin E(2) (PGE(2)). This intrathecally evoked release of spinal PGE(2) was diminished by systemic delivery of nonspecific COX and COX-2-selective inhibitors, but not a COX-1-selective inhibitor. Given at systemic doses that block SP- and carrageenan-evoked hyperalgesia, COX-2, but not COX-1, inhibitors reduced spinal SP-evoked PGE(2) release. Thus, constitutive spinal COX-2, but not COX-1, is an important contributor to the acute antihyperalgesic effects of spinal as well as systemic COX-2 inhibitors.

The aim of this work was to investigate the possible effects of resveratrol on the mitochondrial respiratory chain in rat brains. Isolation of mitochondria was performed at 4 degrees C using differential centrifugation. Mitochondrial respiration rate (0.4 mg of protein/ml) was determined by measuring mitochondrial oxygen consumption with a Clark electrode at 37 degrees C. Respiratory control ratio (RCR) was evaluated as the state 3/state 4 ratio of oxidative phosphorylation with substrates adenosine 5'-diphosphate (ADP) and malate plus glutamate, respectively in the presence and in the absence of resveratrol. The rate of oxygen consumption by the different complexes was checked using rotenone (2 microM), malonate (10 mM), antimycin A (1 microM), potassium cyanide (KCN) (0.3 mM) and oligomycin (10 microM) to inhibit complexes II, III, IV, V and I, respectively. Moreover, enzyme activity determinations were checked as follows: the activities of complexes II-III were measured as the rate of cytochrome c reduction at 550 nm (37 degrees C) successively triggered either by succinate (complexes II and III) or by decylubiquinol (DUQH2) (complex III), in the presence and in the absence of resveratrol. Adenosine 5'-triphosphate (ATP) synthase activity was checked as ATP hydrolysis (ATPase) at 37 degrees C for 10 min from purified mitochondria on Percoll gradient. The inorganic phosphate (Pi) concentration was measured by the Fiske and Subbarow method. When complexes I to V were activated by glutamate plus malate, resveratrol (10(-11) - 10(-4) M) significantly decreased RC (p < 0.001) following a biphasic curve with two EC50 values, 0.162 +/- 0.072 microM and 24.5 +/- 4.0 microM, representing about 56% of total oxygen consumption inhibition. We also observed a concentration-dependent effect on state 3 with two EC50 values, 2.28 +/- 0.87 nM and 27 +/- 5 microM respectively. On the other hand, resveratrol inhibited state 4 following a concentration-dependent curve with an EC50 of 37 +/- 11 microM. When complex IV operated alone, resveratrol (100 microM) did not modify oxygen consumption compared with control, indicating that this molecule did not inhibit complex IV. Thus resveratrol inhibits the mitochondrial respiratory chain through complexes I to III. In order to confirm these data, we measured the enzymatic activity of ubiquinol cytochrome c reductase alone and in the presence of resveratrol. In the presence of disrupted mitochondria, after freeze thawing cycles (three times), resveratrol inhibited about 20% of complex III activity. These results suggest that resveratrol and DUQH2 could be competitive on complex III. Resveratrol significantly inhibited ATPase activity (p < 0.001) following a biphasic curve with two EC50 values, 0.39 +/- 0.15 nM and 23.1 +/- 6.4 microM, both representing about 80% of oligomycin-dependent ATPase total activity. Resveratrol was effective as a protecting agent on the three models of oxidation. On lipid peroxidation of brain synaptosomes induced by the Fenton reaction, it was three times more potent than DUQH2. Its effectiveness in reducing 1,1-diphenyl-2-picryl hydrazyl radical (DPPH degrees) showed a stoichiometry of two, indicating that two hydrogen atoms of resveratrol were abstracted by the process. Resveratrol was also able to scavenge the superoxide anion (O2 degrees) generated from rat forebrain mitochondria in a concentration dependent manner. In conclusion, resveratrol can decrease complex III activity by competition with coenzyme Q. This property is especially interesting as this complex is the site where reactive oxygen substances (ROS) are generated. By decreasing the activity of complex III, resveratrol cannot only oppose the production of ROS but can also scavenge them.

OBJECTIVE

This study evaluated the effectiveness of a brief intervention (BI) for illicit drugs (cannabis, cocaine, amphetamine-type stimulants and opioids) linked to the World Health Organization (WHO) Alcohol, Smoking and Substance Involvement Screening Test (ASSIST). The ASSIST screens for problem or risky use of 10 psychoactive substances, producing a score for each substance that falls into either a low-, moderate- or high-risk category.

METHODS

Prospective, randomized controlled trial in which participants were either assigned to a 3-month waiting-list control condition or received brief motivational counselling lasting an average of 13.8 minutes for the drug receiving the highest ASSIST score.

METHODS

Primary health-care settings in four countries: Australia, Brazil, India and the United States.

METHODS

A total of 731 males and females scoring within the moderate-risk range of the ASSIST for cannabis, cocaine, amphetamine-type stimulants or opioids.

METHODS

ASSIST-specific substance involvement scores for cannabis, stimulants or opioids and ASSIST total illicit substance involvement score at baseline and 3 months post-randomization.

RESULTS

Omnibus analyses indicated that those receiving the BI had significantly reduced scores for all measures, compared with control participants. Country-specific analyses showed that, with the exception of the site in the United States, BI participants had significantly lower ASSIST total illicit substance involvement scores at follow-up compared with the control participants. The sites in India and Brazil demonstrated a very strong brief intervention effect for cannabis scores (P < 0.005 for both sites), as did the sites in Australia (P < 0.005) and Brazil (P < 0.01) for stimulant scores and the Indian site for opioid scores (P < 0.01).

CONCLUSIONS

The Alcohol, Smoking and Substance Involvement Screening Test-linked brief intervention aimed at reducing illicit substance use and related risks is effective, at least in the short term, and the effect generalizes across countries.

We investigated (1) the prevalence of posttraumatic stress disorder (PTSD) in treatment-seeking subjects with substance use dependence (SUD), (2) the association between comorbid PTSD and the severity and course of addiction and psychopathology, and (3) this association in patients with subsyndromal PTSD, and in trauma exposure without PTSD.

In this cross-sectional study, 459 subjects in 14 German addiction treatment centers participated with alcohol-dependence (A) in 39.7%, drug-dependence (D) in 33.6%, or both (AD) 26.8%. The diagnostic measures included the International Diagnostic Checklists (IDCL), Posttraumatic Diagnostic Scale (PDS), Addiction Severity Index (ASI), and the Brief Psychiatric Rating Scale (BPRS). Associations between independent characteristics and outcomes were analysed by univariate and multivariate statistics.

25.3% of the subjects had PTSD confirmed by both IDCL and PDS with higher rates in the AD (34.1%) and D (29.9%) groups compared with group A (15.4%, p < 0.001). In 22.8%, PTSD was subsyndromal (either IDCL or PDS positive) without significant differences between SUD groups, and 18.3% met PTSD trauma criteria A without PTSD (exposure). After controlling for SUD and gender, trauma subgroups significantly differed regarding the onset of alcohol-related symptoms (p < 0.02), numbers of previous admissions (p < 0.03), severity of SUD (p < 0.001), current craving (p < 0.02), and psychopathology (p < 0.001). We observed the worst outcome in PTSD, while trauma exposure had no effects.

The prevalence of PTSD is higher in drug than in alcohol dependence. The more strictly PTSD is diagnosed (by interviewer and questionnaire) the more clearly are associations with characteristics of SUD. PTSD seems to be an independent risk factor for an unfavorable outcome of SUD.

BACKGROUND

Approximately 50% of patients diagnosed with major depressive disorder will experience a recurrent or chronic course of illness for which long-term treatment is recommended. Moreover, at least 20% of patients diagnosed with depression do not respond satisfactorily to several traditional antidepressant medication treatment trials. Very little is known about the health care costs of patients with treatment-resistant depression.

METHODS

Based on medical claims data (MarketScan Research Database, The MEDSTAT Group, Cambridge, Mass.) from January 1, 1995, to June 30, 2000, a naturalistic, retrospective analysis was conducted to study the characteristics and health care utilization of patients with treatment-resistant depression. All patients having an International Classification of Diseases, Ninth Revision (ICD-9), diagnosis code for unipolar or bipolar depression with specified antidepressant dosing and treatment durations were initially selected. Patients were then classified as "treatment resistant" if either they switched from or augmented initial antidepressant medication with other antidepressants at least twice (outpatient treatment-resistant group) or they switched from or augmented their initial antidepressant medication and also had a claim for either a depression-related hospitalization or suicide attempt (hospitalized treatment-resistant group). Those meeting the initial medication and diagnosis selection criteria but not meeting the treatment-resistance criteria constituted the comparison group. Members of the comparison group had comparatively stable antidepressant medication use patterns, consistent with an acceptable response to treatment. Patients were followed for a minimum of 9 months. Resource utilization was calculated from index date to last available claims data point and then annualized.

RESULTS

Treatment-resistant patients were more likely to be diagnosed with bipolar disorder or concurrent substance abuse or anxiety disorders than the comparison group (p <.001). Treatment-resistant patients were at least twice as likely to be hospitalized (general medical and depression related) and had at least 12% more outpatient visits (p <.02). Treatment resistance was also associated with use of 1.4 to 3 times more psychotropic medications (including antidepressants) (p <.001). Patients in the hospitalized treatment-resistant group had over 6 times the mean total medical costs of non-treatment-resistant depressed patients ($42,344 vs. $6512) (p <.001) and their total depression-related costs were 19 times greater than those of patients in the comparison group ($28,001 vs. $1455) (p <.001).

CONCLUSIONS

Treatment-resistant depression is costly and associated with extensive use of depression-related and general medical services. These findings underscore the need for early identification and effective long-term maintenance treatment for treatment-resistant depression.

BACKGROUND

Subarachnoid haemorrhage is commonly associated with natriuresis and hyponatraemia. One possible explanation for these features is a defect in the central regulation of renal sodium reabsorption with increased secretion of a natriuretic factor. We investigated whether excess sodium secretion in patients with subarachnoid haemorrhage is related to increased secretion of natriuretic peptides or to the presence of digoxin-like immunoreactive substances.

METHODS

We measured the plasma concentrations of digoxin-like immunoreactive substances (by a fluorescence polarisation immunoassay) and natriuretic peptides, aldosterone, renin, and antidiuretic hormone (by radioimmunoassay) in ten patients with aneurysmal subarachnoid haemorrhage, ten patients undergoing elective craniotomy for cerebral tumours, and 40 healthy controls of similar age and sex distribution. Samples were collected before surgery, 1 h, 4 h, and 12 h after surgery, then daily until 7 days postoperatively in the two groups of patients.

RESULTS

All patients with subarachnoid haemorrhage, but none of the tumour patients, showed increased urine output and urinary excretion of sodium (p = 0.018 for comparison of means of curves to 7 days). The patients with subarachnoid haemorrhage had much higher plasma concentrations of brain natriuretic peptide (BNP) than controls, on admission (mean 15.1 [SE 3.8] vs 1.6 [1.0] pmol/L, p < 0.001) and throughout the study period, accompanied by lower than normal aldosterone concentrations and normal plasma concentrations of atrial and C-type natriuretic peptides (ANP, CNP). The patients with tumours had similar plasma concentrations of ANP, BNP, and CNP to the controls. We did not detect digoxin-like immunoreactive substances in either group of patients.

CONCLUSIONS

Salt-wasting of central origin may induce hyponatraemia in patients with aneurysmal subarachnoid haemorrhage, possibly as a result of increased secretion of BNP with subsequent suppression of aldosterone synthesis.

The aim of this article is to provide an up-dated overview of the available information on the role played by tachykinins in recruiting/regulating the function of immune/inflammatory cells, an issue which has received considerable input from the recent availability of potent and selective antagonists for tachykinin receptors. It appears that NK1 receptors play a role in mediating the extravascular migration of granulocytes into inflamed tissues in response to various inflammatory stimuli, although this effect may not be due to the expression of NK1 receptors by granulocytes themselves. Several data also imply a role for NK1 and NK2 receptors in regulating immune function. No data are available to suggest the expression of NK3 receptors by inflammatory/immune cells. Mast cell degranulation by substance P appears to be a non-receptor dependent response which may take place in vivo during intense stimulation. An emerging concept in the field relates to the ability of certain immune cell types to synthesize and possibly release tachykinins. Immune cells could represent an additional source of tachykinins in inflamed tissues, providing a non-neurogenic tachykininergic contribution to the local inflammatory process.

BACKGROUND

Methamphetamine abuse is associated with neurotoxicity to frontostriatal brain regions with concomitant deleterious effects on cognitive processes.

METHODS

By using a computerized measure of selective attention and single-voxel proton magnetic resonance spectroscopy, we examined the relationship between attentional control and brain metabolite levels in the anterior cingulate cortex (ACC) and primary visual cortex (PVC) in 36 currently abstinent methamphetamine abusers and 16 non-substance-using controls.

RESULTS

The methamphetamine abusers exhibited reduced attentional control (i.e., increased Stroop interference) compared with the controls (p = .04). Bonferroni-adjusted comparisons revealed that ACC levels of N-acetyl aspartate (NAA)-creatine and phosphocreatine (Cr) were lower and that levels of choline (Cho)-NAA were higher in the methamphetamine abusers compared with the controls, at the adjusted p value of .0125. Levels of NAA-Cr, but not of Cho-NAA, within the ACC correlated with measures of attentional control in the methamphetamine abusers (r = -.41; p = .01) but not in controls (r = .22; p = .42). No significant correlations were observed in the PVC (methamphetamine abusers, r = .19; p = .28, controls, r = .38; p = .15).

CONCLUSIONS

Changes in neurochemicals within frontostriatal brain regions including ACC may contribute to deficits in attentional control among chronic methamphetamine abusers.

We compared the behavioral effects of treatment with pruritogenic and algesiogenic agents in mice. The animals were given subcutaneous injections of pruritogenic agents, compound 48/80 (3-100 micrograms), substance P (10-300 micrograms) and histamine (3-300 micrograms), and algesiogenic agents, capsaicin (30 and 100 micrograms) and dilute formalin (5 mg of formaldehyde), into the rostral back, and scratching of the injected site by the hind paws was counted. Compound 48/80 and substance P dose dependently elicited the scratching behavior, but histamine, capsaicin and dilute formalin were without significant effects at the doses examined. These results suggest that compound 48/80- and substance P-induced scratching of the injected site is due to itch, but not to pain. The data did not provide support for the idea that histamine produces itch in the mouse.

BACKGROUND

Hydrogen sulfide is a luminally acting, bacterially derived cell poison that has been implicated in ulcerative colitis. Sulfide generation in the colon is probably driven by dietary components such as sulfur-containing amino acids (SAAs) and inorganic sulfur (eg, sulfite).

OBJECTIVE

We assessed the contribution of SAAs from meat to sulfide production by intestinal bacteria with use of both a model culture system in vitro and an in vivo human feeding study.

METHODS

Five healthy men were housed in a metabolic suite and fed a sequence of 5 diets for 10 d each. Meat intake ranged from 0 g/d with a vegetarian diet to 600 g/d with a high-meat diet. Fecal sulfide and urinary sulfate were measured in samples collected on days 9 and 10 of each diet period. Additionally, 5 or 10 g bovine serum albumin or casein/L was added to batch cultures inoculated with feces from 4 healthy volunteers. Concentrations of sulfide, ammonia, and Lowry-reactive substances were measured over 48 h.

RESULTS

Mean (+/-SEM) fecal sulfide concentrations ranged from 0.22 +/- 0.02 mmol/kg with the 0-g/d diet to 3.38 +/- 0.31 mmol/kg with the 600-g/d diet and were significantly related to meat intake (P: < 0.001). Sulfide formation in fecal batch cultures supplemented with both bovine serum albumin and casein correlated with protein digestion, as measured by the disappearance of Lowry-reactive substances and the appearance of ammonia.

CONCLUSIONS

Dietary protein from meat is an important substrate for sulfide generation by bacteria in the human large intestine.

Neuropeptides are important mediators both within the nervous system and between neurons and other cell types. Neuropeptides such as substance P, calcitonin gene-related peptide and neuropeptide Y (NPY), vasoactive intestinal polypeptide, somatostatin and corticotropin-releasing factor are also likely to play a role in the bidirectional gut-brain communication. In this capacity they may influence the activity of the gastrointestinal microbiota and its interaction with the gut-brain axis. Current efforts in elucidating the implication of neuropeptides in the microbiota-gut-brain axis address four information carriers from the gut to the brain (vagal and spinal afferent neurons; immune mediators such as cytokines; gut hormones; gut microbiota-derived signalling molecules) and four information carriers from the central nervous system to the gut (sympathetic efferent neurons; parasympathetic efferent neurons; neuroendocrine factors involving the adrenal medulla; neuroendocrine factors involving the adrenal cortex). Apart from operating as neurotransmitters, many biologically active peptides also function as gut hormones. Given that neuropeptides and gut hormones target the same cell membrane receptors (typically G protein-coupled receptors), the two messenger roles often converge in the same or similar biological implications. This is exemplified by NPY and peptide YY (PYY), two members of the PP-fold peptide family. While PYY is almost exclusively expressed by enteroendocrine cells, NPY is found at all levels of the gut-brain and brain-gut axis. The function of PYY-releasing enteroendocrine cells is directly influenced by short chain fatty acids generated by the intestinal microbiota from indigestible fibre, while NPY may control the impact of the gut microbiota on inflammatory processes, pain, brain function and behaviour. Although the impact of neuropeptides on the interaction between the gut microbiota and brain awaits to be analysed, biologically active peptides are likely to emerge as neural and endocrine messengers in orchestrating the microbiota-gut-brain axis in health and disease.

Clinical isolates of Pseudomonas aeruginosa produce low molecular weight, hydrophobic substances which inhibit the growth of Staphylococcus aureus and other Gram-positive organisms. The active substances have been purified from a culture of P. aeruginosa and characterized as a mixture of 2-heptyl-4-hydroxyquinoline N-oxide and its homologues. The alkyl-hydroxyquinolines (derived through reduction of the N-oxide) were also produced by P. aeruginosa cultures but, in general, were less active against S. aureus. 2-Heptyl-4-hydroxyquinoline was identified in a sample of human bronchial secretions from a patient with cystic fibrosis who was heavily colonized with P. aeruginosa. Production of antibacterial alkyl-hydroxyquinoline N-oxides in human lung may explain the observation that the presence of P. aeruginosa in the sputum of patients with cystic fibrosis is correlated with the absence of S. aureus.

This report describes the development and evaluation of a behavioral measure of dietary patterns related to selecting low-fat diets. An 18-item questionnaire, based on an anthropological theory of dietary change, was developed to assess four relevant dimensions of dietary behavior: (a) excluding high-fat ingredients and preparation techniques, (b) modifying high-fat foods, (c) substituting specially manufactured low-fat foods for their higher-fat counterparts, and (d) replacing high-fat foods with low-fat alternatives. In this study, 99 women completed the diet behavior questionnaire twice and, to characterize precisely their dietary fat intake, also completed two 4-day food records and a food frequency questionnaire. Participants were aged 45 to 59 years and were selected to have a wide range of fat intakes (19.4% to 49.4% of calories from fat). Confirmatory factor analysis identified five scales that corresponded to those hypothesized, except for exclusion, which split into avoiding meat and avoiding fat as a seasoning. The scales had high test-retest and internal consistency reliabilities, and correlations with percent of calories from fat ranged from 0.34 to 0.57 (p less than .01). The correlation of the sum of the five scales (18 items) with percent of calories from fat was 0.68 (p less than .001) and, in multiple regression models, the multiple R2 using all factors to predict percent of calories from fat was 0.47. Overall, these findings supported the validity of the theoretical model of dietary patterns related to selecting diets low in fat. We conclude that a standardized, behavioral approach to measuring fat-related dietary behavior may be useful for designing and evaluating nutrition intervention programs.

The global pandemic of COVID-19 is colliding with the epidemic of opioid use disorders (OUD) and other substance use disorders (SUD) in the United States (US). Currently, there is limited data on risks, disparity, and outcomes for COVID-19 in individuals suffering from SUD. This is a retrospective case-control study of electronic health records (EHRs) data of 73,099,850 unique patients, of whom 12,030 had a diagnosis of COVID-19. Patients with a recent diagnosis of SUD (within past year) were at significantly increased risk for COVID-19 (adjusted odds ratio or AOR = 8.699 [8.411-8.997], P < 10^-30), an effect that was strongest for individuals with OUD (AOR = 10.244 [9.107-11.524], P < 10^-30), followed by individuals with tobacco use disorder (TUD) (AOR = 8.222 ([7.925-8.530], P < 10^-30). Compared to patients without SUD, patients with SUD had significantly higher prevalence of chronic kidney, liver, lung diseases, cardiovascular diseases, type 2 diabetes, obesity and cancer. Among patients with recent diagnosis of SUD, African Americans had significantly higher risk of COVID-19 than Caucasians (AOR = 2.173 [2.01-2.349], P < 10^-30), with strongest effect for OUD (AOR = 4.162 [3.13-5.533], P < 10^-25). COVID-19 patients with SUD had significantly worse outcomes (death: 9.6%, hospitalization: 41.0%) than general COVID-19 patients (death: 6.6%, hospitalization: 30.1%) and African Americans with COVID-19 and SUD had worse outcomes (death: 13.0%, hospitalization: 50.7%) than Caucasians (death: 8.6%, hospitalization: 35.2%). These findings identify individuals with SUD, especially individuals with OUD and African Americans, as having increased risk for COVID-19 and its adverse outcomes, highlighting the need to screen and treat individuals with SUD as part of the strategy to control the pandemic while ensuring no disparities in access to healthcare support.

The chapter reviews some of recent evidence which suggests that one neurotrophin, nerve growth factor (NGF), is a peripherally produced mediator of some persistent pain states, notably those associated with inflammation. The evidence for this proposal is as follows. 1. The endogenous production of NGF regulates the sensitivity of nociceptive systems. Behavioural and electrophysiological studies have shown that sequestration of constitutively produced NGF leads to decrease nociceptor sensitivity. 2. In a wide variety of experimental inflammatory conditions NGF levels are rapidly increased in the inflamed tissue. 3. The high-affinity NGF receptor, trkA, is selectively expressed by nociceptive sensory neurons particularly those containing sensory neuropeptides such as substance P and CGRP. 4. The systematic or local application of exogenous NGF produces a rapid and prolonged behavioural hyperalgesia in both animals and humans. Exogenous NGF has also been found to activate and sensitize fine calibre sensory neurons. 5. In a number of animal models, much of the hyperalgesia associated with experimental inflammation is blocked by pharmacological "antagonism' of NGF. The mechanisms by which NGF up-regulation in inflamed tissues might lead to sensory abnormalities is also discussed. In particular, evidence is reviewed which suggests that increased NGF levels leads to both peripheral sensitization of nociceptors and central sensitization of dorsal horn neurons responding to noxious stimuli.

The present study was carried out to investigate the effects of onion (Allium cepa Linn) and garlic (Allium sativum Linn) juices on biochemical parameters, enzyme activities and lipid peroxidation in alloxan-induced diabetic rats. Alloxan was administered as a single dose (120 mg/kg BW) to induce diabetes. A dose of 1 ml of either onion or garlic juices/100 g body weight (equivalent to 0.4 g/100 g BW) was orally administered daily to alloxan-diabetic rats for four weeks. The levels of glucose, urea, creatinine and bilirubin were significantly (p<0.05) increased in plasma of alloxan-diabetic rats compared to the control group. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), and alkaline and acid phosphatases (AlP, AcP) activities were significantly (p<0.05) increased in plasma and testes of alloxan-diabetic rats, while these activities were decreased in liver compared with the control group. Brain LDH was significantly (p<0.05) increased. The concentration of thiobarbituric acid reactive substances and the activity of glutathione S-transferase in plasma, liver, testes, brain, and kidney were increased in alloxan-diabetic rats. Treatment of the diabetic rats with repeated doses of either garlic or onion juices could restore the changes of the above parameters to their normal levels. The present results showed that garlic and onion juices exerted antioxidant and antihyperglycemic effects and consequently may alleviate liver and renal damage caused by alloxan-induced diabetes.

The distribution of perivascular nerve fibers displaying calcitonin gene-related peptide (CGRP) immunoreactivity and the effect of CGRP on vascular smooth muscle were studied in the guinea-pig. Perivascular CGRP fibers were seen in all vascular beds. Generally, they were more numerous around arteries than veins. Small arteries in the respiratory tract, gastrointestinal tract and genitourinary tract had numerous CGRP fibers. The gastroepiploic artery in particular received a rich supply of such fibers. Coronary blood vessels had a moderate supply of CGRP fibers. In the heart, a moderate number of CGRP fibers was seen running close to myocardial fibers. The atria had a richer supply than the ventricles. Numerous CGRP immunoreactive nerve cell bodies and nerve fibers were seen in sensory (trigeminal, jugular and spinal dorsal root) ganglia. Sequential or double immunostaining with antibodies against substance P and CGRP suggested co-existence of the two peptides in nerve cell bodies in the ganglia and in perivascular fibers. In agreement with previous findings CGRP turned out to be a strong vasodilator in vitro as tested on several blood vessels (e.g. basilar, gastroepiploic and mesenteric arteries). Conceivably, perivascular CGRP/SP fibers have a dual role as regulator of local blood flow and as carrier of sensory information.

Sickle cell disease causes severe pain. We examined pain-related behaviors, correlative neurochemical changes, and analgesic effects of morphine and cannabinoids in transgenic mice expressing human sickle hemoglobin (HbS). Paw withdrawal threshold and withdrawal latency (to mechanical and thermal stimuli, respectively) and grip force were lower in homozygous and hemizygous Berkley mice (BERK and hBERK1, respectively) compared with control mice expressing human hemoglobin A (HbA-BERK), indicating deep/musculoskeletal and cutaneous hyperalgesia. Peripheral nerves and blood vessels were structurally altered in BERK and hBERK1 skin, with decreased expression of mu opioid receptor and increased calcitonin gene-related peptide and substance P immunoreactivity. Activators of neuropathic and inflammatory pain (p38 mitogen-activated protein kinase, STAT3, and mitogen-activated protein kinase/extracellular signal-regulated kinase) showed increased phosphorylation, with accompanying increase in COX-2, interleukin-6, and Toll-like receptor 4 in the spinal cord of hBERK1 compared with HbA-BERK. These neurochemical changes in the periphery and spinal cord may contribute to hyperalgesia in mice expressing HbS. In BERK and hBERK1, hyperalgesia was markedly attenuated by morphine and cannabinoid receptor agonist CP 55940. We show that mice expressing HbS exhibit characteristics of pain observed in sickle cell disease patients, and neurochemical changes suggestive of nociceptor and glial activation. Importantly, cannabinoids attenuate pain in mice expressing HbS.

Surface components of virulent and attenuated Leptospira interrogans serovar grippotyphosa were compared by using Triton X-114 solubilization and phase partitioning, immunoprecipitation of intact organisms, and freeze-fracture electron microscopy. Removal of the leptospiral outer membrane by using 0.1% Triton X-114 was demonstrated by whole-mount electron microscopy and by essentially complete solubilization of a lipopolysaccharidelike substance (LLS) from the outer membrane. Triton X-114 (0.1%) did not solubilize subsurface proteins, such as endoflagellar filaments or penicillin-binding proteins, which are markers for the periplasmic space and inner membrane, respectively. Triton X-114 solubilized material from both the virulent and attenuated strains, which partitioned into the hydrophobic, detergent phase, contained LLS and major proteins of 41 and 44 kDa, which were also immunoprecipitable from intact organisms. The virulent strain contained greater amounts of an LLS component with an apparent molecular mass of 30 kDa (R(f) = 0.57), whereas the attenuated strain contained larger amounts of an LLS component with an apparent molecular mass of 20 kDa (R(f) = 0.74). Differences in protein components between virulent and attenuated organisms were also detected; whereas the 41- and 44-kDa proteins were immunoprecipitated in equal amounts from both the virulent and attenuated strains, a 33-kDa protein was immunoprecipitated in significantly greater amounts from the attenuated strain. Quantitation of outer membrane particle density by freeze-fracture electron microscopy showed that both strains had a low transmembrane outer membrane protein content compared with that of typical gram-negative bacteria. The virulent and attenuated strains had 443 and 990 particles (P less than 0.000001) per micron, respectively, in the concave outer membrane fracture face. These findings suggest that in vitro cultivation of L. interrogans is accompanied by quantitative and qualitative changes in both LLS and outer membrane-associated proteins.

Tissue repair following myocardial infarction (MI) eventuates in fibrous tissue formation at the site of myocyte necrosis. Following a large transmural MI, fibrosis appears remote to the infarct site. This is associated with extensive tissue remodeling that adversely affects ventricular diastolic function. Substances involved in promoting fibrous tissue formation at MI and remote sites are under investigation. Angiotensin II (AngII), generated at sites of repair, has been implicated. However, its regulatory role on fibrous tissue formation remains uncertain. In the present study we sought to determine whether AngII is correlated to transforming growth factor beta 1 (TGF-beta1) expression, a regulator of fibrous tissue formation, at these sites of tissue repair. We studied: (1) localization and expression of angiotensin converting enzyme (ACE), AngII receptors, TGF-beta1 mRNA and its receptors in the infarcted rat heart; and (2) effect of AngII on TGF-beta1 synthesis by chronic blockade of AT1 receptors began at the time of surgery by losartan in rats with MI. Hearts were studied at 4 weeks post-MI. We found: (1) low-density ACE, AngII and TGF-beta1 receptor binding and low mRNA for type I collagen and TGF-beta1 in the normal heart; (2) fibrosis at sites of MI and remote to it, including endocardium and fibrosis of intraventricular septum, interstitial fibrosis of non-infarcted myocardium and fibrosis of visceral pericardium; (3) markedly increased (P<0.01) and colocalized ACE, AngII and TGF-beta1 receptor binding, type I collagen and TGF-beta1 mRNA at MI and remote sites of repair; (4) increased TGF-beta1 concentration (P<0. 01) at these sites; and (5) attenuated TGF-beta1 and type I collagen gene expression (P<0.01) at these sites in rats receiving losartan. These observations suggest locally generated AngII via ATi receptor binding is correlated to TGF-beta1 expression and synthesis at sites of repair and remote sites in the infarcted rat heart. The mechanism responsible for the role of AngII in TGF-beta1 remains to be elucidated.

The effect of neuropeptides on plasma protein extravasation was investigated in the abdominal skin of rats. Substance P (SP), neurokinin A (NKA), and neurokinin B (NKB) induced extravasation with a threshold dose of about 1 pmol. Calcitonin gene-related peptide (CGRP) was ineffective up to 6 pmol. However, when CGRP was injected together with either of the tachykinins extravasation was potentiated. A dose of 6 pmol CGRP shifted the dose-response curve of SP to the left by a factor of about 100. The vasoconstrictor neuropeptide Y (NPY, 12 pmol) reduced the extravasation caused by SP or SP plus 6 pmol CGRP. These results indicate that all 3 tachykinins currently known to be present in sensory neurons induce plasma protein extravasation, i.e. mimic one sign of neurogenic inflammation. This activity is potentiated in the presence of CGRP which coexists with SP and NKA indicating that neurogenic inflammation may be augmented by these interactions.

The in vitro brainstem-spinal cord preparation of newborn rats is an established model for the analysis of respiratory network functions. Respiratory activity is generated by interneurons, bilaterally distributed in the ventrolateral medulla. In particular non-NMDA type glutamate receptors constitute excitatory synaptic connectivity between respiratory neurons. Respiratory activity is modulated by a diversity of neuroactive substances such as serotonin, adenosine or norepinephrine. Cl(-)-mediated IPSPs provide a characteristic pattern of membrane potential fluctuations and elevation of the interstitial concentration of (endogenous) GABA or glycine leads to hyperpolarisation-related suppression of respiratory activity. Respiratory rhythm is not blocked upon inhibition of IPSPs with bicuculline, strychnine and saclofen. This indicates that GABA- and glycine-mediated mutual synaptic inhibition is not crucial for in vitro respiratory activity. The primary oscillatory activity is generated by neurons of a respiratory rhythm generator. In these cells, a set of intrinsic conductances such as P-type Ca2+ channels, persistent Na+ channels and G(i/o) protein-coupled K+ conductances mediates conditional bursting. The respiratory rhythm generator shapes the activity of an inspiratory pattern generator that provides the motor output recorded from cranial and spinal nerve rootlets in the preparation. Burst activity appears to be maintained by an excitatory drive due to tonic synaptic activity in concert with chemostimulation by H+. Evoked anoxia leads to a sustained decrease of respiratory frequency, related to K+ channel-mediated hyperpolarisation, whereas opiates or prostaglandins cause longlasting apnea due to a fall of cellular cAMP. The latter observations show that this in vitro model is also suited for analysis of clinically relevant disturbances of respiratory network function.

1. The possible existence of multiple receptors for substance P (SP) was investigated by examining the relative pharmacological potencies of SP and related peptides in contracting guinea pig ileum, in potentiating electrically evoked contractions of rat vas deferens preparations and in competing for 3H-SP receptor binding in rat brain membranes, and by comparing the extent of cross-tachyphylaxis of various analogues with SP in the guinea pig ileum. 2. Different rank orders of potencies were observed among SP, its C-terminal fragments, analogues and related tachykinins in the different test systems, and these could not be explained by differential access to the target organ receptors. 3. In contrast to SP and physalaemin, both eledoisin and a metabolically stable SP analogue, [pGlu5, MePhe8, Sar9]-SPP tachyphylaxis in the guinea pig ileum, and part of their spasmogenic action in this preparation was atropine-sensitive. 4. The results suggest the possible existence of multiple SP receptors, and the specificity of those in the brain may be different from those in the gut. The structural and pharmacological basis for subdividing tachykinins into SP-physalaemin and eledoisin-kassinin families is also discussed.