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Publication
Journal: Archives of general psychiatry
February/11/2013
Abstract
CONTEXT Prospective studies of childhood attention-deficit/hyperactivity disorder (ADHD) have not extended beyond early adulthood. OBJECTIVE To examine whether children diagnosed as having ADHD at a mean age of 8 years (probands) have worse educational, occupational, economic, social, and marital outcomes and higher rates of ongoing ADHD, antisocial personality disorder (ASPD), substance use disorders (SUDs), adult-onset psychiatric disorders, psychiatric hospitalizations, and incarcerations than non-ADHD comparison participants at a mean age of 41 years. DESIGN Prospective, 33-year follow-up study, with masked clinical assessments. SETTING Research clinic. PARTICIPANTS A total of 135 white men with ADHD in childhood, free of conduct disorder, and 136 men without childhood ADHD (65.2% and 76.4% of original cohort, respectively). MAIN OUTCOME MEASURES Occupational, economic, and educational attainment; marital history; occupational and social functioning; ongoing and lifetime psychiatric disorders; psychiatric hospitalizations; and incarcerations. RESULTS Probands had significantly worse educational, occupational, economic, and social outcomes; more divorces; and higher rates of ongoing ADHD (22.2% vs 5.1%, P < .001), ASPD (16.3% vs 0%, P < .001), and SUDs (14.1% vs 5.1%, P = .01) but not more mood or anxiety disorders (P = .36 and .33) than did comparison participants. Ongoing ADHD was weakly related to ongoing SUDs (ϕ = 0.19, P = .04), as well as ASPD with SUDs (ϕ = 0.20, P = .04). During their lifetime, probands had significantly more ASPD and SUDs but not mood or anxiety disorders and more psychiatric hospitalizations and incarcerations than comparison participants. Relative to comparisons, psychiatric disorders with onsets at 21 years or older were not significantly elevated in probands. Probands without ongoing psychiatric disorders had worse social, but not occupational, functioning. CONCLUSIONS The multiple disadvantages predicted by childhood ADHD well into adulthood began in adolescence, without increased onsets of new disorders after 20 years of age. Findings highlight the importance of extended monitoring and treatment of children with ADHD.
Publication
Journal: Circulation Research
November/11/2002
Abstract
The orphan receptor APJ and its recently identified endogenous ligand, apelin, exhibit high levels of mRNA expression in the heart. However, the functional importance of apelin in the cardiovascular system is not known. In isolated perfused rat hearts, infusion of apelin (0.01 to 10 nmol/L) induced a dose-dependent positive inotropic effect (EC50: 33.1+/-1.5 pmol/L). Moreover, preload-induced increase in dP/dt(max) was significantly augmented (P<0.05) in the presence of apelin. Inhibition of phospholipase C (PLC) with U-73122 and suppression of protein kinase C (PKC) with staurosporine and GF-109203X markedly attenuated the apelin-induced inotropic effect (P<0.001). In addition, zoniporide, a selective inhibitor of Na+-H+ exchange (NHE) isoform-1, and KB-R7943, a potent inhibitor of the reverse mode Na+-Ca2+ exchange (NCX), significantly suppressed the response to apelin (P<0.001). Perforated patch-clamp recordings showed that apelin did not modulate L-type Ca2+ current or voltage-activated K+ currents in isolated adult rat ventricular myocytes. Apelin mRNA was markedly downregulated in cultured neonatal rat ventricular myocytes subjected to mechanical stretch and in vivo in two models of chronic ventricular pressure overload. The present study provides the first evidence for the physiological significance of apelin in the heart. Our results show that apelin is one of the most potent endogenous positive inotropic substances yet identified and that the inotropic response to apelin may involve activation of PLC, PKC, and sarcolemmal NHE and NCX.
Publication
Journal: Annals of the New York Academy of Sciences
August/14/2002
Abstract
Inflammation in the joint causes peripheral sensitization (increase of sensitivity of nociceptive primary afferent neurons) and central sensitization (hyperexcitability of nociceptive neurons in the central nervous system). The processes of sensitization are thought to be the basis of arthritic pain that appears as spontaneous pain (joints at rest) and hyperalgesia (augmented pain response on noxious stimulation and pain on normally nonpainful stimulation). Sensitization also facilitates efferent neuronal processes through which the nervous system influences the inflammatory process. Peripheral sensitization is produced by the action of inflammatory mediators such as bradykinin, prostaglandins, neuropeptides, and cytokines which activate corresponding receptors in proportions of nerve fibers. In addition, the expression of receptors, for example, bradykinin and neurokinin 1 receptors, is upregulated during inflammation. The development of hyperexcitability of spinal cord neurons is produced by various transmitter/receptor systems that constitute and modulate synaptic activation of the neurons. The key transmitter is glutamate that activates N-methyl-d-aspartate (NMDA) and non-NMDA receptors on spinal cord neurons. Blockade of these receptors prevents and reduces central sensitization. Excitatory neuropeptides (substance P and calcitonin gene-related peptide) further central sensitization. Central sensitization also is facilitated by mediators that have complex actions (e.g., prostaglandin E(2)). Spinal PGE(2) binds to receptors at presynaptic endings of primary afferent neurons (thus influencing synaptic release) and to receptors on postsynaptic spinal cord neurons. The administration of PGE(2) to the spinal cord surface produces changes of responsiveness of spinal neurons similar to peripheral inflammation, and spinal indomethacin to the spinal cord attenuates development of hyperexcitability significantly.
Publication
Journal: Pharmacological Reviews
October/29/2002
Abstract
The tachykinin peptide family certainly represents one of the largest peptide families described in the animal organism. So far, more than 40 tachykinins have been isolated from invertebrate (insects, worms, and molluscs), protochordate, and vertebrate (skin, gastrointestinal tract, peripheral and central nervous system) tissues. Substance P (SP), first identified by bioassay as early as 1931 but sequenced only in 1971, several years after the elucidation of the structure of eledoisin from molluscan tissues and of physalaemin from amphibian skin, may be considered as a prototype of the tachykinins. Hitherto, as many as 19 tachykinins have been isolated from amphibian integument, and eight additional peptides have been isolated from amphibian gut and brain. Counterparts of skin tachykinins in mammalian tissues are SP, neurokinin A, and neurokinin B. Three main receptor subtypes for the tachykinins have been identified (NK1, NK2, and NK3), but their number is probably destined to increase. It is obvious that the peripheral and central effects of the tachykinins may substantially vary depending on the activation of different receptor subtypes. Matters are further complicated by the frequent capacity of the single tachykinins to bind, although with different affinity, to more receptors. It has been recognized that tachykinins have a variety of effects in physiological and pathological conditions, and there is evidence suggesting intrinsic neuroprotective and neurodegenerative properties of these neuropeptides. This review provides an update on the current body of knowledge regarding tachykinin occurrence and distribution in the animal kingdom, from the lowest invertebrates to man, and the physiological and pharmacological actions of tachykinins outlining the pregnant importance of this large peptide family.
Publication
Journal: Biochimica et Biophysica Acta - General Subjects
August/13/1978
Abstract
The uptake of phosphate and phosphorylated compounds into the chloroplast stroma has been studied by silicone layer filtering centrifugation. 1. Inorganic phosphate, 3-phosphoglycerate, dihydroxyacetone phosphate and glyceraldehyde phosphate are transported across the envelope leading to an accumulation in the chloroplast stroma. This uptake proceeds by a counter exchange with phosphate and phosphorylated compounds present there. 2. The transport shows saturation characteristics allowing the determination of Km and V. 3. The phosphorylated compounds transported act as competitive inhibitors of the transport. From measurements of the Km and Ki the specificity of the transport is described. 4. The transport of inorganic phosphate and 3-phosphoglycerate is inhibited by p-chloromercuriphenyl sulfonate, pyridoxal 5'-phosphate and trinitrobenzene sulfonate. 5. The activation energy of phosphate transport as determined from the temperature dependence is evaluated to be 16 kcal (0--12 degrees C). 6. It is concluded that inorganic phosphate, 3-phosphoglycerate, dihydroxy-acetone phosphate and glyceraldehyde phosphate are transported by the same carrier, which has been nominated phosphate translocator. 7. Simultaneous measurements of the proton concentration in the medium and the transport into the chloroplasts show that the transfer of 3-phosphoglycerate involves a transfer of a proton into the same direction. 8. Measurements of the pH dependence of the transport indicate that all substances including 3-phosphoglycerate are transported by the phosphate translocator as divalent anions. 9. The physiological function of the phosphate translocator is discussed.
Publication
Journal: Experimental Brain Research
May/10/1999
Abstract
The nature of dorsal root reflexes (DRRs) and their possible role in peripheral inflammation and the consequent hyperalgesia are reviewed. The history of DRRs and the relationship of DRRs to primary afferent depolarization and presynaptic inhibition in pathways formed by both large and fine afferents are discussed. Emphasis is placed on the mechanisms underlying primary afferent depolarization, including the anatomical arrangement of the synapses involved, how depolarization can result in inhibition by decreasing transmitter release, the role of excitatory amino acids and GABA, the manner in which the equilibrium potential for chloride ions is determined in primary afferent fibers, and forms of presynaptic inhibition that do not utilize GABA(A) receptors. There is then a discussion of neurogenic inflammation, including the role of the release of neuropeptides such as substance P and calcitonin gene-related peptide from sensory nerve endings. Evidence is reviewed that links DRRs to a substantial part of the swelling of the knee joint in acute experimental arthritis and to the flare reaction in the skin following intradermal injection of capsaicin. Possible mechanisms by which the level of DRR activity might be enhanced following inflammation are suggested. The consequences of this increase in DRRs may include exacerbation of hyperalgesia as well as of peripheral inflammation. The conversion of an inhibitory process, presynaptic inhibition, to an excitatory one by DRRs can thus lead to pathological consequences.
Authors
Publication
Journal: Nature
September/28/1977
Publication
Journal: British Journal of Clinical Pharmacology
March/27/2011
Abstract
OBJECTIVE
Optimization of drug prescribing in older populations is a priority due to the significant clinical and economic costs of drug-related illness. This study aimed to: (i) estimate the prevalence of potentially inappropriate prescribing (PIP) in a national Irish older population using European specific explicit prescribing criteria; (ii) investigate the association between PIP, number of drug classes, gender and age and; (iii) establish the total cost of PIP.
METHODS
This was a retrospective national population study (n= 338 801) using the Health Service Executive Primary Care Reimbursement Service (HSE-PCRS) pharmacy claims database. The HSE-PCRS uses the WHO Anatomical Therapeutic Chemical (ATC) classification system and details of every drug dispensed and claimants' demographic data are available. Thirty PIP indicators (STOPP) were applied to prescription claims for those>>or=70 years in Ireland in 2007. STOPP is a physiological system based screening tool of older persons' potentially inappropriate prescriptions assessing drug-drug and drug-disease interactions, dose and duration.
RESULTS
In our study population PIP prevalence was 36% (121 454 claimants). The main contributors to this were: 56 560 (17%) prescribed proton pump inhibitors at maximum therapeutic dose for >8 weeks, 29 691 (9%) prescribed non-steroidal anti-inflammatories for >3 months, 17 676 (5%) prescribed long-acting benzodiazepines for >1 month and 16 201 (5%) prescribed duplicate drugs. The main determinant of PIP was polypharmacy. The likelihood of PIP increased with a significant linear and quadratic trend (P < 0.0001) with the number of drug classes.The maximum net ingredient cost of PIP was estimated to be euro38 664 640. Total PIP expenditure was estimated to be euro45 631 319, 9% of the overall expenditure on pharmaceuticals in those>>or=70 years in 2007.
CONCLUSIONS
The findings identify a high prevalence of PIP in Ireland with significant cost consequences.
Publication
Journal: Gastroenterology
August/29/2001
Abstract
OBJECTIVE
Gastrointestinal complications of long-standing diabetes include nausea, vomiting, abdominal pain, diarrhea, and constipation. The pathophysiology underlying these symptoms is poorly understood. Recent evidence suggests an important role for interstitial cells of Cajal in controlling gastrointestinal motility. The aim of this study was to determine changes in interstitial cells of Cajal and enteric innervation in a patient with insulin-dependent diabetes.
METHODS
A full thickness jejunal biopsy was obtained from a 38-year-old insulin-dependent diabetic with evidence for diabetic gastroenteropathy. Immunohistochemistry, confocal microscopy, and 3-dimensional reconstruction techniques were used to quantify changes in the volume of interstitial cells of Cajal and enteric innervation.
RESULTS
Interstitial cells of Cajal were markedly decreased throughout the entire thickness of the jejunum. A decrease in neuronal nitric oxide synthase, vasoactive intestinal peptide, PACAP, and tyrosine hydroxylase immunopositive nerve fibers was observed in circular muscle layer while substance P immunoreactivity was increased.
CONCLUSIONS
The data suggest that long-standing diabetes is associated with a decrease in interstitial cells of Cajal volume and a decrease in inhibitory innervation, associated with an increase in excitatory innervation. The changes in interstitial cells of Cajal volume and enteric nerves may underlie the pathophysiology of gastrointestinal complications associated with diabetes and suggest future therapeutic targets.
Publication
Journal: American Journal of Physiology - Regulatory Integrative and Comparative Physiology
June/4/2009
Abstract
Quercetin is one of a broad group of natural polyphenolic flavonoid substances that are being investigated for their widespread health benefits. These benefits have generally been ascribed to its combination of antioxidant and anti-inflammatory activity, but recent in vitro evidence suggests that improved mitochondrial biogenesis could play an important role. In addition, the in vivo effects of quercetin on mitochondrial biogenesis exercise tolerance are unknown. We examined the effects of 7 days of quercetin feedings in mice on markers of mitochondrial biogenesis in skeletal muscle and brain, and on endurance exercise tolerance. Mice were randomly assigned to one of the following three treatment groups: placebo, 12.5 mg/kg quercetin, or 25 mg/kg quercetin. Following 7 days of treatment, mice were killed, and soleus muscle and brain were analyzed for mRNA expression of peroxisome proliferator-activated receptor-gamma coactivator (PGC-1alpha) and sirtuin 1 (SIRT1), and mitochondrial DNA (mtDNA) and cytochrome c. Additional mice underwent a treadmill performance run to fatigue or were placed in voluntary activity wheel cages, and their voluntary activity (distance, time, and peak speed) was recorded. Quercetin increased mRNA expression of PGC-1alpha and SIRT1 (P < 0.05), mtDNA (P < 0.05) and cytochrome c concentration (P < 0.05). These changes in markers of mitochondrial biogenesis were associated with an increase in both maximal endurance capacity (P < 0.05) and voluntary wheel-running activity (P < 0.05). These benefits of querectin on fitness without exercise training may have important implications for enhancement of athletic and military performance and may also extend to prevention and/or treatment of chronic diseases.
Publication
Journal: Cochrane Database of Systematic Reviews
September/30/2015
Abstract
BACKGROUND
Neuraminidase inhibitors (NIs) are stockpiled and recommended by public health agencies for treating and preventing seasonal and pandemic influenza. They are used clinically worldwide.
OBJECTIVE
To describe the potential benefits and harms of NIs for influenza in all age groups by reviewing all clinical study reports of published and unpublished randomised, placebo-controlled trials and regulatory comments.
METHODS
We searched trial registries, electronic databases (to 22 July 2013) and regulatory archives, and corresponded with manufacturers to identify all trials. We also requested clinical study reports. We focused on the primary data sources of manufacturers but we checked that there were no published randomised controlled trials (RCTs) from non-manufacturer sources by running electronic searches in the following databases: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, MEDLINE (Ovid), EMBASE, Embase.com, PubMed (not MEDLINE), the Database of Reviews of Effects, the NHS Economic Evaluation Database and the Health Economic Evaluations Database.
METHODS
Randomised, placebo-controlled trials on adults and children with confirmed or suspected exposure to naturally occurring influenza.
METHODS
We extracted clinical study reports and assessed risk of bias using purpose-built instruments. We analysed the effects of zanamivir and oseltamivir on time to first alleviation of symptoms, influenza outcomes, complications, hospitalisations and adverse events in the intention-to-treat (ITT) population. All trials were sponsored by the manufacturers.
RESULTS
We obtained 107 clinical study reports from the European Medicines Agency (EMA), GlaxoSmithKline and Roche. We accessed comments by the US Food and Drug Administration (FDA), EMA and Japanese regulator. We included 53 trials in Stage 1 (a judgement of appropriate study design) and 46 in Stage 2 (formal analysis), including 20 oseltamivir (9623 participants) and 26 zanamivir trials (14,628 participants). Inadequate reporting put most of the zanamivir studies and half of the oseltamivir studies at a high risk of selection bias. There were inadequate measures in place to protect 11 studies of oseltamivir from performance bias due to non-identical presentation of placebo. Attrition bias was high across the oseltamivir studies and there was also evidence of selective reporting for both the zanamivir and oseltamivir studies. The placebo interventions in both sets of trials may have contained active substances. Time to first symptom alleviation. For the treatment of adults, oseltamivir reduced the time to first alleviation of symptoms by 16.8 hours (95% confidence interval (CI) 8.4 to 25.1 hours, P < 0.0001). This represents a reduction in the time to first alleviation of symptoms from 7 to 6.3 days. There was no effect in asthmatic children, but in otherwise healthy children there was (reduction by a mean difference of 29 hours, 95% CI 12 to 47 hours, P = 0.001). Zanamivir reduced the time to first alleviation of symptoms in adults by 0.60 days (95% CI 0.39 to 0.81 days, P < 0.00001), equating to a reduction in the mean duration of symptoms from 6.6 to 6.0 days. The effect in children was not significant. In subgroup analysis we found no evidence of a difference in treatment effect for zanamivir on time to first alleviation of symptoms in adults in the influenza-infected and non-influenza-infected subgroups (P = 0.53). Hospitalisations. Treatment of adults with oseltamivir had no significant effect on hospitalisations: risk difference (RD) 0.15% (95% CI -0.78 to 0.91). There was also no significant effect in children or in prophylaxis. Zanamivir hospitalisation data were unreported. Serious influenza complications or those leading to study withdrawal. In adult treatment trials, oseltamivir did not significantly reduce those complications classified as serious or those which led to study withdrawal (RD 0.07%, 95% CI -0.78 to 0.44), nor in child treatment trials; neither did zanamivir in the treatment of adults or in prophylaxis. There were insufficient events to compare this outcome for oseltamivir in prophylaxis or zanamivir in the treatment of children. Pneumonia. Oseltamivir significantly reduced self reported, investigator-mediated, unverified pneumonia (RD 1.00%, 95% CI 0.22 to 1.49); number needed to treat to benefit (NNTB) = 100 (95% CI 67 to 451) in the treated population. The effect was not significant in the five trials that used a more detailed diagnostic form for pneumonia. There were no definitions of pneumonia (or other complications) in any trial. No oseltamivir treatment studies reported effects on radiologically confirmed pneumonia. There was no significant effect on unverified pneumonia in children. There was no significant effect of zanamivir on either self reported or radiologically confirmed pneumonia. In prophylaxis, zanamivir significantly reduced the risk of self reported, investigator-mediated, unverified pneumonia in adults (RD 0.32%, 95% CI 0.09 to 0.41); NNTB = 311 (95% CI 244 to 1086), but not oseltamivir. Bronchitis, sinusitis and otitis media. Zanamivir significantly reduced the risk of bronchitis in adult treatment trials (RD 1.80%, 95% CI 0.65 to 2.80); NNTB = 56 (36 to 155), but not oseltamivir. Neither NI significantly reduced the risk of otitis media and sinusitis in both adults and children. Harms of treatment. Oseltamivir in the treatment of adults increased the risk of nausea (RD 3.66%, 95% CI 0.90 to 7.39); number needed to treat to harm (NNTH) = 28 (95% CI 14 to 112) and vomiting (RD 4.56%, 95% CI 2.39 to 7.58); NNTH = 22 (14 to 42). The proportion of participants with four-fold increases in antibody titre was significantly lower in the treated group compared to the control group (RR 0.92, 95% CI 0.86 to 0.97, I(2) statistic = 0%) (5% absolute difference between arms). Oseltamivir significantly decreased the risk of diarrhoea (RD 2.33%, 95% CI 0.14 to 3.81); NNTB = 43 (95% CI 27 to 709) and cardiac events (RD 0.68%, 95% CI 0.04 to 1.0); NNTB = 148 (101 to 2509) compared to placebo during the on-treatment period. There was a dose-response effect on psychiatric events in the two oseltamivir "pivotal" treatment trials, WV15670 and WV15671, at 150 mg (standard dose) and 300 mg daily (high dose) (P = 0.038). In the treatment of children, oseltamivir induced vomiting (RD 5.34%, 95% CI 1.75 to 10.29); NNTH = 19 (95% CI 10 to 57). There was a significantly lower proportion of children on oseltamivir with a four-fold increase in antibodies (RR 0.90, 95% CI 0.80 to 1.00, I(2) = 0%). Prophylaxis. In prophylaxis trials, oseltamivir and zanamivir reduced the risk of symptomatic influenza in individuals (oseltamivir: RD 3.05% (95% CI 1.83 to 3.88); NNTB = 33 (26 to 55); zanamivir: RD 1.98% (95% CI 0.98 to 2.54); NNTB = 51 (40 to 103)) and in households (oseltamivir: RD 13.6% (95% CI 9.52 to 15.47); NNTB = 7 (6 to 11); zanamivir: RD 14.84% (95% CI 12.18 to 16.55); NNTB = 7 (7 to 9)). There was no significant effect on asymptomatic influenza (oseltamivir: RR 1.14 (95% CI 0.39 to 3.33); zanamivir: RR 0.97 (95% CI 0.76 to 1.24)). Non-influenza, influenza-like illness could not be assessed due to data not being fully reported. In oseltamivir prophylaxis studies, psychiatric adverse events were increased in the combined on- and off-treatment periods (RD 1.06%, 95% CI 0.07 to 2.76); NNTH = 94 (95% CI 36 to 1538) in the study treatment population. Oseltamivir increased the risk of headaches whilst on treatment (RD 3.15%, 95% CI 0.88 to 5.78); NNTH = 32 (95% CI 18 to 115), renal events whilst on treatment (RD 0.67%, 95% CI -2.93 to 0.01); NNTH = 150 (NNTH 35 to NNTB>> 1000) and nausea whilst on treatment (RD 4.15%, 95% CI 0.86 to 9.51); NNTH = 25 (95% CI 11 to 116).
CONCLUSIONS
Oseltamivir and zanamivir have small, non-specific effects on reducing the time to alleviation of influenza symptoms in adults, but not in asthmatic children. Using either drug as prophylaxis reduces the risk of developing symptomatic influenza. Treatment trials with oseltamivir or zanamivir do not settle the question of whether the complications of influenza (such as pneumonia) are reduced, because of a lack of diagnostic definitions. The use of oseltamivir increases the risk of adverse effects, such as nausea, vomiting, psychiatric effects and renal events in adults and vomiting in children. The lower bioavailability may explain the lower toxicity of zanamivir compared to oseltamivir. The balance between benefits and harms should be considered when making decisions about use of both NIs for either the prophylaxis or treatment of influenza. The influenza virus-specific mechanism of action proposed by the producers does not fit the clinical evidence.
Publication
Journal: Journal of Immunology
April/19/1998
Abstract
We present data demonstrating the gene expression of substance P and its receptor in human peripheral blood-isolated monocytes and macrophages. Using the RT-PCR assay, preprotachykinin-A (substance P) mRNA is detected in human peripheral blood-isolated monocytes and macrophages. Among the alpha, beta, and gamma transcripts of the substance P gene, only the beta and gamma transcripts are detectable in these cells. By Southern blot assay these RT-PCR-amplified transcripts are recognized using a specific substance P probe. Sequence analysis of the RT-PCR products from both monocytes and macrophages also confirmed the structure of these transcripts, which are identical to those found in human neuronal cells. At the protein level, both human monocytes and macrophages produced endogenous substance P as determined by an enzyme immunoassay. Capsaicin, a vanillyl fatty acid amide (ingredient of hot pepper), released substance P from both human monocytes and macrophages. In addition, using nested RT-PCR analysis, we identified the presence of mRNA for neurokinin-1 receptor (the receptor for substance P) in human peripheral blood-isolated monocytes and macrophages, which was confirmed by DNA sequencing analysis. The demonstration that human monocytes and macrophages express substance P and its receptor support the notion that substance P is biologically involved in regulating the functions of these cells in an autocrine fashion.
Publication
Journal: Journal of Neuroscience
April/20/2009
Abstract
Brainstem serotonin (5-HT) neurons modulate activity of many neural circuits in the mammalian brain, but in many cases endogenous mechanisms have not been resolved. Here, we analyzed actions of raphé 5-HT neurons on respiratory network activity including at the level of the pre-Bötzinger complex (pre-BötC) in neonatal rat medullary slices in vitro, and in the more intact nervous system of juvenile rats in arterially perfused brainstem-spinal cord preparations in situ. At basal levels of activity, excitation of the respiratory network via simultaneous release of 5-HT and substance P (SP), acting at 5-HT(2A/2C), 5-HT(4), and/or neurokinin-1 receptors, was required to maintain inspiratory motor output in both the neonatal and juvenile systems. The midline raphé obscurus contained spontaneously active 5-HT neurons, some of which projected to the pre-BötC and hypoglossal motoneurons, colocalized 5-HT and SP, and received reciprocal excitatory connections from the pre-BötC. Experimentally augmenting raphé obscurus activity increased motor output by simultaneously exciting pre-BötC and motor neurons. Biophysical analyses in vitro demonstrated that 5-HT and SP modulated background cation conductances in pre-BötC and motor neurons, including a nonselective cation leak current that contributed to the resting potential, which explains the neuronal depolarization that augmented motor output. Furthermore, we found that 5-HT, but not SP, can transform the electrophysiological phenotype of some pre-BötC neurons to intrinsic bursters, providing 5-HT with an additional role in promoting rhythm generation. We conclude that raphé 5-HT neurons excite key circuit components required for generation of respiratory motor output.
Publication
Journal: Journal of Physiology
October/6/1975
Abstract
1. 45-Ca uptake by pinched-off nerve terminals (synaptosomes) of rat brain incubated in standard physiological saline (including 132 mM-Na + 5mM-K + 1-2 mM-Ca) at 30 degrees C averages about 0-5 mumole Ca per g protein per minute. This may be equivalent to a Ca influx of about 0-03 p-mole/cm-2 sec. 2. The rate of 45-Ca uptake is increased when the concentration of K in the medium is increased above 15-20 mM, K replacing Na isosmotically. Maximum stimulation, a three- to six-fold increase in the rate of Ca uptake, occurs when [K]o is about 60 mM. The effect of increased [K]o is reversible. 3. The K-stimulated Ca uptake is associated primarily with the nerve terminal fraction of brain homogenates. The entering Ca is not accompanied by extracellular markers such as mannitol or inulin. Replacement of external chloride by methylsulphate or sulphate does not prevent the stimulation by K. 4. The effects of external K are quantitatively mimicked by Rb. Caesium also stimulates Ca uptake, but is only about one fifth as effective as K or Rb; Li is ineffective. 5. Two other depolarizing agents also stimulate Ca uptake by synaptosomes: veratridine (7-5 times 10- minus 6 to 7-5 times 10- minus 5 M) and scorpion (Leirus quinquestriatus) venom (6-7 times 10- minus 7 to 6-7 times 10- minus g/ml.). The stimulatory effects of veratridine and scorpion venom, but not of increased [K] are blocked by 2 times 10- minus 7 M tetrodotoxin. 6. Internal K also influences the rate of 45-Ca uptake by synaptosomes: lowering [K]i reduces the stimulatory effect of external K and veratridine. 7. Replacement of external Na by choline markedly inhibits the response to veratridine, but has a much smaller effect on the response to increased [K]o. 8. The Ca uptake mechanism has an apparent dissociation constant for Ca (KCa) of about 0-8 mM. Increasing [K]o increases the maximal rate of Ca uptake, but has no effect on KCa. The K-induced 45-Ca uptake is competitively inhibited by Mg-2+, Mn-2+ and La-3+. 9. The release of acetylcholine and noradrenaline was also studied. Increasing [K]o stimulates external Ca-dependent acetylcholine release. Scorpion venom stimulates noradrenaline release from synaptosomes; this effect could be prevented by adding tetrodotoxin or removing external Ca. 10. These results indicate that synaptosomes may increase their permeability to Ca, accumulate Ca and release neural transmitter substances, when stimulated by depolarizing agents under appropriate physiological conditions.
Publication
Journal: Gastroenterology
January/1/1997
Abstract
Gastrointestinal motility and sensory perception are altered in a variety of mucosal inflammatory conditions of the gut, ranging from peptic esophagitis to ulcerative colitis. Studies in animal models now clearly indicate a causal relationship between the presence of mucosal inflammation and altered sensory-motor function. In many instances, these changes occur in the absence of any discernible encroachment of the deeper neuromuscular layers by the inflammatory infiltrate, which remains largely within the lamina propria. Accordingly, attention has focused on local sources of mediators, and recent studies indicate that smooth muscle cells and enteroglia are sources of and targets for cytokines such as interleukin 1 beta and interleukin 6. In several instances, neuromuscular dysfunction persists after mucosal inflammation has subsided; this state may be maintained by locally produced mediators. Studies also show the ability of enteric muscle to modulate lymphocyte function via major histocompatibility complex II-restricted antigen presentation. Clinical observation and experimental data also suggest that nerves modulate intestinal inflammation via local release of proinflammatory neuropeptides (substance P) and via the activation of extensive circuits that may involve the brain. Taken together, these findings provide plausible explanations for a variety of clinical scenarios ranging from inflammatory bowel disease to pseudo-obstruction syndromes and subgroups of functional bowel disorders.
Publication
Journal: Archives of general psychiatry
March/30/2009
Abstract
BACKGROUND
There has been a great deal of research on the comorbidity between alcohol abuse or dependence (AAD) and major depression (MD). However, it is unclear whether AAD increases the risk of MD or vice versa.
OBJECTIVE
To examine the associations between AAD and MD using fixed-effects modeling to control for confounding and using structural equation models to ascertain the direction of causality.
METHODS
Data were gathered during the course of the Christchurch Health and Development Study, a 25-year longitudinal study of a birth cohort of children from New Zealand (635 boys, 630 girls).
METHODS
General community sample.
METHODS
The analysis was based on a sample of 1055 participants with available data on AAD and MD at ages 17 to 18, 20 to 21, and 24 to 25 years.
METHODS
Symptom criteria for AAD and MD from the DSM-IV at ages 17 to 18, 20 to 21, and 24 to 25 years as well as measures of life stress, cannabis use, other illicit drug use, affiliation with deviant peers, unemployment, partner substance use, and partner criminality at ages 17 to 18, 20 to 21, and 24 to 25 years.
RESULTS
There were significant (P < .001) pooled associations between AAD and MD. Controlling for confounding factors using conditional fixed-effects models and time-dynamic covariate factors reduced the magnitude of these associations, but they remained statistically significant. Structural equation modeling suggested that the best-fitting causal model was one in which AAD led to increased risk of MD.
CONCLUSIONS
The findings suggest that the associations between AAD and MD were best explained by a causal model in which problems with alcohol led to increased risk of MD as opposed to a self-medication model in which MD led to increased risk of AAD.
Publication
Journal: Neuroscience
September/13/2000
Abstract
In order to investigate the sequence and pattern of neurodegeneration in Huntington's disease, the distribution and density of cannabinoid CB(1), dopamine D(1) and D(2), adenosine A(2a) and GABA(A) receptor changes were studied in the basal ganglia in early (grade 0), intermediate (grades 1, 2) and advanced (grade 3) neuropathological grades of Huntington's disease. The results showed a sequential pattern of receptor changes in the basal ganglia with increasing neuropathological grades of Huntington's disease. First, the very early stages of the disease (grade 0) were characterized by a major loss of cannabinoid CB(1), dopamine D(2) and adenosine A(2a) receptor binding in the caudate nucleus, putamen and globus pallidus externus and an increase in GABA(A) receptor binding in the globus pallidus externus. Second, intermediate neuropathological grades (grades 1, 2) showed a further marked decrease of CB(1) receptor binding in the caudate nucleus and putamen; this was associated with a loss of D(1) receptors in the caudate nucleus and putamen and a loss of both CB(1) and D(1) receptors in the substantia nigra. Finally, advanced grades of Huntington's disease showed an almost total loss of CB(1) receptors and the further depletion of D(1) receptors in the caudate nucleus, putamen and globus pallidus internus, and an increase in GABA(A) receptor binding in the globus pallidus internus. These findings suggest that there is a sequential but overlapping pattern of neurodegeneration of GABAergic striatal efferent projection neurons in increasing neuropathological grades of Huntington's disease. First, GABA/enkephalin striatopallidal neurons projecting to the globus pallidus externus are affected in the very early grades of the disease. Second, GABA/substance P striatonigral neurons projecting to the substantia nigra are involved at intermediate neuropathological grades. Finally, GABA/substance P striatopallidal neurons projecting to the globus pallidus internus are affected in the late grades of the disease. In addition, the finding that cannabinoid receptors are dramatically reduced in all regions of the basal ganglia in advance of other receptor changes in Huntington's disease suggests a possible role for cannabinoids in the progression of neurodegeneration in Huntington's disease.
Publication
Journal: Environmental Health Perspectives
February/25/2008
Abstract
BACKGROUND
Previous studies of DDT and breast cancer assessed exposure later in life when the breast may not have been vulnerable, after most DDT had been eliminated, and after DDT had been banned.
OBJECTIVE
We investigated whether DDT exposure in young women during the period of peak DDT use predicts breast cancer.
METHODS
We conducted a prospective, nested case-control study with a median time to diagnosis of 17 years using blood samples obtained from young women during 1959-1967. Subjects were members of the Child Health and Development Studies, Oakland, California, who provided blood samples 1-3 days after giving birth (mean age, 26 years). Cases (n = 129) developed breast cancer before the age of 50 years. Controls (n = 129) were matched to cases on birth year. Serum was assayed for p,p'-DDT, the active ingredient of DDT; o,p'-DDT, a low concentration contaminant; and p,p'-DDE, the most abundant p,p'-DDT metabolite.
RESULTS
High levels of serum p,p'-DDT predicted a statistically significant 5-fold increased risk of breast cancer among women who were born after 1931. These women were under 14 years of age in 1945, when DDT came into widespread use, and mostly under 20 years as DDT use peaked. Women who were not exposed to p,p'-DDT before 14 years of age showed no association between p,p'-DDT and breast cancer (p = 0.02 for difference by age).
CONCLUSIONS
Exposure to p,p'-DDT early in life may increase breast cancer risk. Many U.S. women heavily exposed to DDT in childhood have not yet reached 50 years of age. The public health significance of DDT exposure in early life may be large.
Publication
Journal: Gastroenterology
November/22/1983
Abstract
The regional and topographic distribution of endocrine cells in the human intestine was examined by immunohistochemistry. The frequency of endocrine cells was greatest in the small intestine with the rectum next in order. The duodenum and jejunum harbored a large number of different endocrine cell types; the spectrum of cell types gradually narrowed distally in the intestine. 5-Hydroxytryptamine-containing enterochromaffin cells were present in all regions of the intestine and comprised the single largest endocrine cell population. In addition, a minor proportion of these cells contained substance P. The second largest cell population consisted of the glicentin cells, which were notably numerous in the ileum and colon. The somatostatin cells also occurred throughout the digestive tract. Cells storing cholecystokinin, motilin, secretin, or gastric inhibitory polypeptide were more numerous in the proximal and middle small intestine than distally. Gastrin cells were few and occurred in the proximal duodenum only. Other cells in the small intestine reacted with antiserum directed against the common C-terminus of gastrin and cholecystokinin. The number of these cells greatly exceeded the sum of cells reactive to gastrin-specific or cholecystokinin-specific antisera. Cells displaying beta-endorphin, pro-gamma-melanocyte-stimulating hormone, or beta-lipotropin immunoreactivity, or a combination of these, were found in the small intestine. Cells storing neurotensin, glicentin, substance P, or pro-gamma-melanocyte-stimulating hormone increased in number distally in the small intestine. Enterochromaffin cells, glicentin cells, and somatostatin cells were the predominant endocrine cell types in the colon and rectum. The majority of the glicentin-immunoreactive cells also contained glucagon and pancreatic polypeptide-like immunoreactivity. Endocrine cells in the large intestine often possessed basal processes.
Publication
Journal: Applied and Environmental Microbiology
June/15/2000
Abstract
The effect of lactic acid on the outer membrane permeability of Escherichia coli O157:H7, Pseudomonas aeruginosa, and Salmonella enterica serovar Typhimurium was studied utilizing a fluorescent-probe uptake assay and sensitization to bacteriolysis. For control purposes, similar assays were performed with EDTA (a permeabilizer acting by chelation) and with hydrochloric acid, the latter at pH values corresponding to those yielded by lactic acid, and also in the presence of KCN. Already 5 mM (pH 4.0) lactic acid caused prominent permeabilization in each species, the effect in the fluorescence assay being stronger than that of EDTA or HCl. Similar results were obtained in the presence of KCN, except for P. aeruginosa, for which an increase in the effect of HCl was observed in the presence of KCN. The permeabilization by lactic and hydrochloric acid was partly abolished by MgCl(2). Lactic acid sensitized E. coli and serovar Typhimurium to the lytic action of sodium dodecyl sulfate (SDS) more efficiently than did HCl, whereas both acids sensitized P. aeruginosa to SDS and to Triton X-100. P. aeruginosa was effectively sensitized to lysozyme by lactic acid and by HCl. Considerable proportions of lipopolysaccharide were liberated from serovar Typhimurium by these acids; analysis of liberated material by electrophoresis and by fatty acid analysis showed that lactic acid was more active than EDTA or HCl in liberating lipopolysaccharide from the outer membrane. Thus, lactic acid, in addition to its antimicrobial property due to the lowering of the pH, also functions as a permeabilizer of the gram-negative bacterial outer membrane and may act as a potentiator of the effects of other antimicrobial substances.
Publication
Journal: American Journal of Gastroenterology
September/16/2004
Abstract
OBJECTIVE
Products of systemic lipid peroxidation are important in the pathogenesis of cardiovascular disease. Subjects with NASH have increased hepatic lipid peroxidation, but it is unknown if they have increased oxidative stress and lipid peroxidation systemically. Therefore, we conducted a study to measure the circulating levels of lipid peroxidation products and their metabolic and nutritional correlates in patients with NASH and controls.
METHODS
Systemic lipid peroxidation was assessed by measuring the levels of oxidized LDL (ox-LDL) and thiobarbituric acid-reacting substances (TBARS) in 21 subjects with NASH and 19 controls. Correlations were made between serum lipid peroxidation and nutritional determinants of oxidative stress and defense, serum lipids, insulin resistance, transaminases, and liver histology. The short-term nutrient intake was analyzed by maintaining a 3-wk dietary diary.
RESULTS
The serum levels of ox-LDL were significantly higher in NASH patients compared to controls (56 +/- 16 U/L vs 40 +/- 12 U/L, respectively, p < 0.001). Similarly, serum TBARS were significantly higher in NASH patients compared to controls (3.4 +/- 1.3 vs 1.8 +/- 0.9 nmols/ml, respectively, p= 0.0001). Insulin resistance was independently associated with ox-LDL (p= 0.01) and TBARS levels (p= 0.01). We found no differences in the intake of various macro- and micronutrients between the two groups and there was no association between nutrient intake and ox-LDL or TBARS.
CONCLUSIONS
Subjects with NASH have significantly higher systemic levels of lipid peroxidation products and this could indicate an increased risk of cardiovascular disease. More studies are needed to evaluate this possibility.
Publication
Journal: Cell
January/17/2007
Abstract
In type 1 diabetes, T cell-mediated death of pancreatic beta cells produces insulin deficiency. However, what attracts or restricts broadly autoreactive lymphocyte pools to the pancreas remains unclear. We report that TRPV1(+) pancreatic sensory neurons control islet inflammation and insulin resistance. Eliminating these neurons in diabetes-prone NOD mice prevents insulitis and diabetes, despite systemic persistence of pathogenic T cell pools. Insulin resistance and beta cell stress of prediabetic NOD mice are prevented when TRPV1(+) neurons are eliminated. TRPV1(NOD), localized to the Idd4.1 diabetes-risk locus, is a hypofunctional mutant, mediating depressed neurogenic inflammation. Delivering the neuropeptide substance P by intra-arterial injection into the NOD pancreas reverses abnormal insulin resistance, insulitis, and diabetes for weeks. Concordantly, insulin sensitivity is enhanced in trpv1(-/-) mice, whereas insulitis/diabetes-resistant NODxB6Idd4-congenic mice, carrying wild-type TRPV1, show restored TRPV1 function and insulin sensitivity. Our data uncover a fundamental role for insulin-responsive TRPV1(+) sensory neurons in beta cell function and diabetes pathoetiology.
Publication
Journal: Nature
December/9/1987
Abstract
The neuropeptide receptors which are present in very small quantities in the cell and are embedded tightly in the plasma membrane have not been well characterized. Mammals contain three distinct tachykinin neuropeptides, substance P, substance K and neuromedin K, and it has been suggested that there are multiple tachykinin receptors. By electrophysiological measurement, we have previously shown that Xenopus oocytes injected with brain and stomach mRNAs faithfully express mammalian substance-P and substance-K receptors, respectively. Here we report the isolation of the cDNA clone for bovine substance-K receptor (SKR) by extending this method to develop a new cloning strategy. We constructed a stomach cDNA library with a cloning vector that allowed in vitro synthesis of mRNAs and then identified a particular cDNA clone by testing for receptor expression following injection of the mRNAs synthesized in vitro into the oocyte system. Because oocytes injected with exogenous mRNAs can express numerous receptors and channels, our new strategy will be applicable in the general molecular cloning of these proteins. The result provides the first indication that the neuropeptide receptor has sequence similarity with rhodopsin-type receptors (the G-protein-coupled receptor family) and thus possesses multiple membrane-spanning domains.
Publication
Journal: Journal of Physiology
January/28/1977
Abstract
The possibility that L-glutamate is the excitatory transmitter at the Drosophila larval neuromuscular junction and the ionic basis of its action on the muscle membrane are examined. 2. Iontophoretically applied L-glutamate causes muscle depolarization (L-glutamate potential) if and only if the L-glutamate pipette is within a few mum of the nerve ending. D-glutamate, substance P, ACh and GABA are ineffective. 3. Bath-applied L-glutamate produces similar changes in the time course and amplitude of miniature excitatory junctional potential (m.e.j.p.), excitatory junctional potential (e.j.p.) and the L-glutamate potential. 4. Neuromuscular transmission and excitation-contraction coupling are operative in a haemolymph-like solution containing 1 mM L-glutamate. 5. The reversal potentials of the e.j.p. and the L-glutamate potential are identical to each other, changing similarly with changes in the ionic compositions of the external medium (twelve solutions). 6. The ionic dependence of the reversal potentials is predicted from an extended constant-field equation using a ratio of sodium:potassium permeabilities of PNa/PK=1-3, and a ratio of magnesium:potassium permeabilities of PMg/PK=4-7. 7. It is concluded that L-glutamate is, or is an agonist of, the excitatory transmitter at certain Drosophila larval neuromuscular junctions.
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