Agmatine reverses pain induced by inflammation, neuropathy, and spinal cord injury

Antagonists of glutamate receptors of the N-methyl-d-aspartate subclass (NMDAR) or inhibitors of nitric oxide synthase (NOS) prevent nervous system plasticity. Inflammatory and neuropathic pain rely on plasticity, presenting a clinical opportunity for the use of NMDAR antagonists and NOS inhibitors in chronic pain. Agmatine (AG), an endogenous neuromodulator present in brain and spinal cord, has both NMDAR antagonist and NOS inhibitor activities. We report here that AG, exogenously administered to rodents, decreased hyperalgesia accompanying inflammation, normalized the mechanical hypersensitivity (allodynia/hyperalgesia) produced by chemical or mechanical nerve injury, and reduced autotomy-like behavior and lesion size after excitotoxic spinal cord injury. AG produced these effects in the absence of antinociceptive effects in acute pain tests. Endogenous AG also was detected in rodent lumbosacral spinal cord in concentrations similar to those previously detected in brain. The evidence suggests a unique antiplasticity and neuroprotective role for AG in processes underlying persistent pain and neuronal injury.

A dichotomous role for nitric oxide during acute Toxoplasma gondii infection in mice

Production of nitric oxide by macrophages is believed to be an important microbicidal mechanism for a variety of intracellular pathogens, including Toxoplasma gondii. Mice with a targeted disruption of the inducible nitric oxide synthase gene (iNOS) were infected orally with T. gondii tissue cysts. Time to death was prolonged compared with parental controls. Histologic analysis of tissue from infected mice showed scattered small foci of inflammation with parasites in various tissues of iNOS−/− mice, whereas tissue from the parental C57BL/6 mice had more extensive tissue inflammation with few visible parasites. In particular, extensive ulceration and necrosis of distal small intestine and fatty degeneration of the liver was seen in the parental mice at day 7 postinfection, as compared with the iNOS−/− mice where these tissues appeared normal. Serum interferon γ and tumor necrosis factor α levels postinfection were equally elevated in both mouse strains. Treatment of the parental mice with a NO synthase inhibitor, aminoguanidine, prevented early death in these mice as well as the hepatic degeneration and small bowel necrosis seen in acutely infected control parentals. These findings indicate that NO production during acute infection with T. gondii can kill intracellular parasites but can be detrimental, even lethal, to the host.

Deprivation and emergency admissions for cancers of colorectum, lung, and breast in south east England: ecological study

Objectives: To examine the relation between deprivation and acute emergency admissions for cancers of the colon, rectum, lung, and breast in south east England.

Excitotoxicity in the lung: N-methyl-D-aspartate-induced, nitric oxide-dependent, pulmonary edema is attenuated by vasoactive intestinal peptide and by inhibitors of poly(ADP-ribose) polymerase.

Excitatory amino acid toxicity, resulting from overactivation of N-methyl-D-aspartate (NMDA) glutamate receptors, is a major mechanism of neuronal cell death in acute and chronic neurological diseases. We have investigated whether excitotoxicity may occur in peripheral organs, causing tissue injury, and report that NMDA receptor activation in perfused, ventilated rat lungs triggered acute injury, marked by increased pressures needed to ventilate and perfuse the lung, and by high-permeability edema. The injury was prevented by competitive NMDA receptor antagonists or by channel-blocker MK-801, and was reduced in the presence of Mg2+. As with NMDA toxicity to central neurons, the lung injury was nitric oxide (NO) dependent: it required L-arginine, was associated with increased production of NO, and was attenuated by either of two NO synthase inhibitors. The neuropeptide vasoactive intestinal peptide and inhibitors of poly(ADP-ribose) polymerase also prevented this injury, but without inhibiting NO synthesis, both acting by inhibiting a toxic action of NO that is critical to tissue injury. The findings indicate that: (i) NMDA receptors exist in the lung (and probably elsewhere outside the central nervous system), (ii) excessive activation of these receptors may provoke acute edematous lung injury as seen in the "adult respiratory distress syndrome," and (iii) this injury can be modulated by blockade of one of three critical steps: NMDA receptor binding, inhibition of NO synthesis, or activation of poly(ADP-ribose) polymerase.

Desfechos tardios de sobreviventes de ensaio clínico randomizado controlado (protocolo ARDSnet vs. Open Lung Approach para o manejo ventilatório da síndrome do desconforto respiratório agudo moderado-grave)

Apesar da utilização da ventilação mecânica protetora como estratégia para o tratamento da síndrome do desconforto respiratório agudo, ao menos um quarto dos pacientes com essa síndrome ainda apresentam redução na função pulmonar após 6 meses de seguimento. Não se sabe se esta redução está relacionada com a gravidade da síndrome ou associada com a forma de ventilar o paciente. Nosso objetivo neste trabalho foi avaliar a associação entre alterações funcionais e estruturais do pulmão com parâmetros de gravidade clínica e de ventilação mecânica. Foi realizada uma análise secundária dos dados obtidos em estudo randomizado e controlado que incluiu pacientes com síndrome do desconforto respiratório agudo moderada/grave, internados em seis unidades de terapia intensiva em um hospital terciário da cidade de São Paulo. Foram analisados dados de pacientes que tinham ao menos um teste de função pulmonar no seguimento. O teste funcional incluiu a medida da capacidade vital forçada, volumes pulmonares e a capacidade de difusão do monóxido de carbono após 1, 2 e 6 meses de seguimento. Foram considerados variáveis independentes o volume corrente, a pressão de distensão e a pressão positiva ao final da expiração (todos medidos após 24 horas da randomização) e um sistema de classificação de prognóstico (APACHE II), a relação PaO2/FIO2 e a complacência respiratória estática (todos medidos antes da randomização). Também foi realizada tomografia de alta resolução do tórax juntamente com os testes de função pulmonar, e posterior análise quantitativa das imagens. Na avaliação de 6 meses também foi realizado teste de caminhada de 6 minutos e um questionário de qualidade de vida (SF-36). Um total de 21 pacientes realizaram o teste de função pulmonar após 1 mês e 15 pacientes realizaram após 2 e 6 meses de seguimento. A capacidade vital forçada foi relacionada inversamente com a pressão de distensão na avaliação de 1, 2 e 6 meses (p < 0,01). A capacidade de difusão do monóxido de carbono relacionou-se inversamente com a pressão de distensão e com o APACHE II (ambos p < 0,01) na avaliação de 1 e 2 meses. Após 6 meses de seguimento, houve correlação inversa entre a pressão de distensão e a capacidade vital forçada independente do volume corrente, da pressão de platô e da complacência estática respiratória após ajustes (R2 = 0,51, p = 0,02). A pressão de distensão também se relacionou com o volume pulmonar total, a densidade pulmonar media e a porcentagem de volume pulmonar não aerado ou pobremente aerado medidos através da análise quantitativa da tomografia computadorizada de tórax realizada na avaliação de 6 meses. Também foi observada relação entre a qualidade de vida após 6 meses de seguimento e a pressão de distensão considerando o domínio estado geral de saúde. Nós concluímos que mesmo em pacientes ventilados com reduzido volume corrente e pressão de platô limitada, maiores valores de pressão de distensão relacionaram-se com menores valores de função pulmonar no seguimento de longo prazo

The Role of IL-25 in Colitis-Associated Colon Cancer and Pulmonary Inflammation

Thesis (Ph.D.)--University of Washington, 2016-06

Differential expression of muscle damage in humans following acute fast and slow velocity eccentric exercise

We sought to determine if the velocity of an acute bout of eccentric contractions influenced the duration and severity of several common indirect markers of muscle damage. Subjects performed 36 maximal fast (FST, n=8: 3.14 rad center dot s(-1)) or slow (SLW, n=7: 0.52 rad center dot s(-1)) velocity isokinetic eccentric contractions with the elbow flexors of the non-dominant arm. Muscle soreness, limb girth, plasma creatine kinase (CK) activity, isometric torque and concentric and eccentric torque at 0.52 and 3.14 rad center dot s(-1) were assessed prior to and for several days following the eccentric bout. Peak plasma CK activity was similar in SLW (4030 +/- 1029 U center dot l(-1)) and FST (5864 +/- 2664 U center dot l(-1)) groups, (p > 0.05). Both groups experienced similar decrement in all strength variables during the 48 hr following the eccentric bout. However, recovery occurred more rapidly in the FST group during eccentric (0.52 and 3.14 rad center dot s(-1)) and concentric (3.14 rad center dot s(-1)) post-testing. The severity of muscle soreness was similar in both groups. However, the FST group experienced peak muscle soreness 48 hr later than the SLW group (24 hr vs. 72 hr). The SLW group experienced a greater increase in upper arm girth than the FST group 20 min, 24 hr and 96 hr following the eccentric exercise bout. The contraction velocity of an acute bout of eccentric exercise differentially influences the magnitude and time course of several indirect markers of muscle damage.

Inflammatory markers are associated with ventilatory limitation and muscle dysfunction in obstructive lung disease in well functioning elderly subjects

Background: Inflammatory markers are increased in chronic obstructive pulmonary disease ( COPD) and are hypothesised to play an important part in muscle dysfunction and exercise intolerance. Methods: The Health Aging and Body Composition ( Health ABC) study is a prospective observational cohort of well functioning individuals aged 70 - 79 years. A cross sectional analysis of the baseline data was conducted to examine the association between inflammatory markers and ventilatory limitation, muscle strength, and exercise capacity. These associations were compared in participants with and without obstructive lung disease ( OLD). Results: Of the 3075 participants enrolled in the Health ABC cohort, OLD was identified by spirometric testing in 268 participants and 2005 participants had normal spirometric results. Of the participants with OLD, 35%, 38%, and 27% participants had mild, moderate, and severe OLD, respectively. Participants with OLD had lower quadriceps strength (102.5 Nm v 108.9 Nm, p = 0.02), lower maximum inspiratory pressure (64.7 cm H2O v 74.2 cm H2O, p< 0.0001), higher systemic interleukin (IL)-6 levels (2.6 pg/ml v 2.2 pg/ml, p< 0.0001), and higher C-reactive protein (CRP) levels (3.5 mg/l v 2.5 mg/l, p< 0.0001) than those with normal spirometry. In participants with OLD and those with normal spirometry, forced expiratory volume in 1 second (FEV1) was associated with IL-6 ( adjusted regression coefficients (beta) = -5.3 (95% CI -9.1 to -1.5) and -3.1 (95% CI -4.3 to -1.9), respectively). IL-6 and TNF were also associated with quadriceps strength among participants with OLD and those with normal spirometry (beta = -6.4 (95% CI -12.8 to -0.03) and -3.4 (95% CI -5.4 to -1.3), respectively, for IL-6 and beta = -10.1 (95% CI -18.7 to -1.5) and -3.8 (95% CI -7 to -0.6), respectively, for TNF). IL-6, quadriceps strength, and maximum inspiratory pressures were independent predictors of reduced exercise capacity in both groups. Conclusions: In well functioning elderly subjects with or without OLD, IL-6 is associated with reduced FEV1, quadriceps strength, and exercise capacity.

Macrophage-specific expression of human lysosomal acid lipase corrects inflammation and pathogenic phenotypes in lal(-/-) mice

Lysosomal acid lipase (LAL) hydrolyzes cholesteryl esters and triglycerides to generate free fatty acids and cholesterol in the cell. The downstream metabolites of these compounds serve as hormonal ligands for nuclear receptors and transcription factors. Genetic ablation of the lal gene in the mouse caused malformation of macrophages and inflammation-triggered multiple pathogenic phenotypes in multiple organs. To assess the relationship between macro phages and lal(-/-) pathogenic phenotypes, a macrophage-specific doxycycline-inducible transgenic system was generated to induce human LAL (hLAL) expression in the lal(-/-) genetic background under control of the 7.2-kb c-fins promoter/intron2 regulatory sequence. Doxycycline-induced hLAL expression in macrophages significantly ameliorated aberrant gene expression, inflammatory cell (neutrophil) influx, and pathogenesis in multiple organs. These studies strongly support that neutral lipid metabolism in macrophages contributes to organ inflammation and pathogenesis.

Physiological and haematological findings and clinical observations in a model of acute systemic anaphylaxis in Dirofilaria immitis-sensitised cats

Objective This study aims to understand the pathophysiology of anaphylaxis in Dirofflaria immitis-sensitised cats by analysing objective physiological and haematological measurements after challenge. Design Nineteen healthy D immitis-naive cats were sensitised using weekly injections of aluminium hydroxide-adjuvanted D immitis antigen, administered subcutaneously over 6 weeks. After sensitisation, cats (n = 16) were anaesthetised and challenged with intravenous D immitis antigen. A control group (n = 3) was sham-challenged using intravenous sterile 0.9% saline. Systolic blood pressure (measured non-invasively/indirectly), respiratory rate, degree of dyspnoea, blood 0, saturation, expired CO2, and heart rate and were measured immediately before and at 10 to 15 min intervals after challenge until terminal apnoea occurred or euthanasia at 140 mins post-challenge. Blood was collected for complete blood count immediately before and at 10, 20 and 35 mins after challenge. Clinical observations were recorded as they occurred. Results Antigen-challenged cats were divided into two groups: acute (apnoea occurred within 25 mins of challenge) and subacute (breathing at 25 mins after challenge). In both groups, the degree of dyspnoea increased and blood O-2 saturation and blood pressure decreased. Respiratory rate increased in the subacute group. Expired CO2 decreased in both Ag-challenged and control groups. Haematocrit increased in the subacute group. Neutrophil count decreased in the acute group and platelet count decreased in the subacute group. Eosinophil count decreased in the subacute and control groups. Sustained dyspnoea and gastrointestinal signs were the most common clinical manifestations of anaphylaxis in the antigen-challenged cats. Conclusions Intravenous challenge with D immitis antigen in sensitised cats results in dyspnoea, hypoxaemia and systemic hypotension accompanied by haemoconcentration.

Segmental lung lobe torsion in a 7-week-old Pug

Case summary: A 7-week-old, intact female Pug was referred with an acute history of expiratory dyspnea, tachypnea, and pyrexia. Radiologic evaluation revealed bilateral pleural effusion and a poorly demarcated area of soft tissue opacity cranial to the heart. The presence of air bronchograms in the cranial lung lobes suggested alveolar parenchymal pathology consistent with pulmonary edema, congestion, or cellular infiltration. Exploratory thoracotomy revealed a segmental torsion of the left cranial lung lobe. The affected lobe was removed and the puppy recovered uneventfully. Unique information: Lung lobe torsion tends to occur more frequently in mature large breed dogs at a mean age of 3 years. The age, breed, and segmental nature of the torsion in the reported case are contrary to most of the previously documented cases of lung lobe torsion. To the authors' knowledge, this is the first report of lung lobe torsion in a 7-week-old dog.

Downregulation of IgE antibody and allergic responses in the lung by epidermal biolistic microparticle delivery

Background: Biolistic injections provide a needle-free delivery of antigen-laden microparticles to the epithelium. The precision of the injection preferentially targets the Langerhans cell network, which, although ideal for vaccination, might not be suitable for the downregulation of immune responses in immunotherapy. Objective: We sought to determine the ability of biolistic injection of antigen into the epithelium of sensitized mice to inhibit IgE antibody and lung inflammatory responses produced by further exposure to antigen. Methods: Mice were sensitized by means of a needle injection of ovalbumin (OVA) in alum and given a series of biolistic injections of OVA or vehicle control, followed by a boost of OVA in alum. Serum IgE and IgG antibodies were measured before and after the boost. The mice were then challenged intranasally, and the infiltration of inflammatory cells was measured by means of bronchoalveolar lavage. Airway reactivity of the challenged mice was measured by examining responses to methacholine with forced oscillatory techniques. Results: Biolistic injection of OVA into the dorsal skin of sensitized mice markedly inhibited IgE and IgG1 antibody responses induced by boosting. IgG2a antibody responses were reduced rather than stimulated. The eosinophilic inflammation in the bronchoalveolar lavage fluid induced by intranasal challenge was also markedly inhibited. Lung hyperreactivity showed an initial increase and then a decrease of responsiveness to methacholine, with elastance returning to the level of unsensitized mice. Biolistic injection into the buccal epithelium was also inhibitory. Conclusions: Biolistic injection of allergen inhibited the boosting of IgE antibody and eosinophilic lung inflammatory responses without inducing TO immunity.

Mediators of monocyte activity in inflammation

C-reactive protein (CRP) is the prototypic acute phase serum protein in humans. CRP is currently one of the best markers of inflammatory disease and disease activity. One of the keys cells involved in inflammation within chronic inflammatory diseases is the monocyte. Monocytes are able to modulate inflammation through cytokine expression, cytosolic peroxide formation, adhesion molecule expression and subsequent adhesion/migration to sites of inflammation. CRP has been previously shown to bind directly to monocytes through Fc receptors. However this observation is not conclusive and requires further investigation. The effects of incubation of CRP with human primary and monocytic cell lines were examined using monocytic cytokine expression, adhesion molecule expression and adhesion to endothelial cells and intracellular peroxide formation, as end points. Monocytic intracellular signalling events were investigated after interaction of CRP with specific CRP receptors on monocytes. These initial signalling events were examined for their role in modulating monocytic adhesion molecule and cytokine expression. Monocyte recruitment and retention in the vasculature is also influenced by oxidative stress. Therefore the effect of 6 weeks of antioxidant intervention in vivo was examined on monocytic adhesion molecule expression, adhesion to endothelial cells ex vivo and on serum CRP concentrations, pre- and post- supplementation with the antioxidants vitamin C and vitaInin E. In summary, CRP is able to bind FcγRIIa. CRP binding FcγR initiates an intracellular signalling cascade that phosphorylates the non-receptor tyrosine kinase, Syk, associated with intracellular tyrosine activating motifs on the cytoplasmic tail of Fcγ receptors. CRP incubations increased phosphatidyl inositol turnover and Syk phosphorylation ultimately lead to Ca2+ mobilisation in monocytes. CRP mediated Syk phosphorylation in monocytes leads to an increase in CD 11b and IL-6 expression. CRP engagement with monocytes also leads to an increase in peroxide production, which can be inhibited in vitro using the antioxidants α-tocopherol and ascorbic acid. CRP mediated CD 11b expression is not redox regulated by CRP mediated changes in cytosolic peroxides. The FcyRIla polymorphism at codon 131 effects the phenotypic driven changes described in monocytes by CRP, where R/R allotypes have a greater increase in CD11b, in response to CRP, which may be involved in promoting the monocytic inflammatory response. CRP leads to an increase in the expression of pro-inflammatory cytokines, which alters the immune phenotype of circulating monocytes. Vitamin C supplementation reduced monocytic adhesion to endothelial cells, but had no effect on serum levels of CRP. Where long-term antioxidant intervention may provide benefit from the risk of developing vascular inflammatory disease, by reducing monocytic adhesion to the vasculature. In conclusion CRP appears to be much more than just a marker of ongoing inflammation or associated inflammatory disease and disease activity. This data suggests that at pathophysiological concentrations, CRP may be able to directly modulate inflammation through interacting with monocytes and thereby alter the inflammatory response associated with vascular inflammatory diseases.

Studies on bacterial lung infections in cystic fibrosis

The major cause of death in CF is a continuous inflammation of the lungs colonised with Pseudomonas aeruginosa and occasionally also with Burkholderia cepacia. A combination of serum IgG to LPS and serum PCT levels were found to be good markers for detection of early colonisation with P. aeruginosa. Colomycin sulphomethate (colistin E) is one of the antibiotics used to treat P. aeruginosa infections in CF. Electrophoretic methods were developed to monitor the rate of conversion of colomycin sulphomethate to the active form of the drug. Antimicrobial activity towards P. aeruginosa was generated as the sulphomethate substituents were released. Clinical resistance of P. aeruginosa to colomycin is rare, but a number of isolates have been isolated. Twelve colomycin-resistant clinical isolates were investigated to determine the mechanism of resistance. It was found that the low level of resistance was due to over expression of outer membrane protein H (OprH) in 5 isolates. A novel mechanism of resistance involving modification of the phosphate groups in LPS was identified in one of the isolates. Drugs which reduce inflammation in infected CF lungs would be of great advantage for therapy. Reducing inflammation would preserve the lung function and increase the quality of life for CF patients. Antibiotics like tetracyclines, macrolides and polymyxins were tested for their potential anti-inflammatory effects using cultured human monocytic (U937) cells which secrete the pro-inflammatory cytokines IL1- and TNF- in response to LPS from P. aeruginosa and B. cepacia. It was found that tetracyclines, and especially doxycycline, are good inhibitors of cytokine release by U937 cells and therefore could reduce the inflammatory cascade.