Insights into FcγR involvement in pain-like behavior induced by an RA-derived anti-modified protein autoantibody

Joint pain is one of the most debilitating symptoms of rheumatoid arthritis (RA) and patients frequently rate improvements in pain management as their priority. RA is hallmarked by the presence of anti-modified protein autoantibodies (AMPA) against post-translationally modified citrullinated, carbamylated and acetylated proteins. It has been suggested that autoantibody-mediated processes represent distinct mechanisms contributing to pain in RA. In this study, we investigated the pronociceptive properties of monoclonal AMPA 1325:01B09 (B09 mAb) derived from the plasma cell of an RA patient. We found that B09 mAb induces pain-like behavior in mice that is not associated with any visual, histological or transcriptional signs of inflammation in the joints, and not alleviated by non-steroidal anti-inflammatory drugs (NSAIDs). Instead, we found that B09 mAb is retained in dorsal root ganglia (DRG) and alters the expression of several satellite glia cell (SGC), neuron and macrophage-related factors in DRGs. Using mice that lack activating FcγRs, we uncovered that FcγRs are critical for the development of B09-induced pain-like behavior, and partially drive the transcriptional changes in the DRGs. Finally, we observed that B09 mAb binds SGC in vitro and in combination with external stimuli like ATP enhances transcriptional changes and protein release of pronociceptive factors from SGCs. We propose that certain RA antibodies bind epitopes in the DRG, here on SGCs, form immune complexes and activate resident macrophages via FcγR cross-linking. Our work supports the growing notion that autoantibodies can alter nociceptor signaling via mechanisms that are at large independent of local inflammatory processes in the joint.

Docosahexaenoic acid and etanercept could reduce functional and metabolic alterations during collagen-induced arthritis in rats without any synergistic effect

AIMS

Rheumatoid arthritis is an autoimmune disease which induces chronic inflammation and increases the risk for sarcopenia and metabolic abnormalities. Nutritional strategies using omega 3 polyunsaturated fatty acids could be proposed to alleviate inflammation and improve the maintenance of lean mass. Independently, pharmacological agents targeting key molecular regulators of the pathology such as TNF alpha could be proposed, but multiple therapies are frequently necessary increasing the risk for toxicity and adverse effects. The aim of the present study was to explore if the combination of an anti-TNF therapy (Etanercept) with dietary supplementation with omega 3 PUFA could prevent pain and metabolic effects of RA.

MATERIALS AND METHODS

RA was induced using collagen-induced arthritis (CIA) in rats to explore of supplementation with docosahexaenoic acid, treatment with etanercept or their association could alleviate symptoms of RA (pain, dysmobility), sarcopenia and metabolic alterations.

KEY FINDINGS

We observed that Etanercept had major benefits on pain and RA scoring index. However, DHA could reduce the impact on body composition and metabolic alterations.

SIGNIFICANCE

This study revealed for the first time that nutritional supplementation with omega 3 fatty acid could reduce some symptoms of rheumatoid arthritis and be an effective preventive treatment in patients who do not need pharmacological therapy, but no sign of synergy with an anti-TNF agent was observed.

A consensus protocol for functional connectivity analysis in the rat brain

Task-free functional connectivity in animal models provides an experimental framework to examine connectivity phenomena under controlled conditions and allows for comparisons with data modalities collected under invasive or terminal procedures. Currently, animal acquisitions are performed with varying protocols and analyses that hamper result comparison and integration. Here we introduce StandardRat, a consensus rat functional magnetic resonance imaging acquisition protocol tested across 20 centers. To develop this protocol with optimized acquisition and processing parameters, we initially aggregated 65 functional imaging datasets acquired from rats across 46 centers. We developed a reproducible pipeline for analyzing rat data acquired with diverse protocols and determined experimental and processing parameters associated with the robust detection of functional connectivity across centers. We show that the standardized protocol enhances biologically plausible functional connectivity patterns relative to previous acquisitions. The protocol and processing pipeline described here is openly shared with the neuroimaging community to promote interoperability and cooperation toward tackling the most important challenges in neuroscience.

Identification of Lipid Biomarkers for Chronic Joint Pain Associated with Different Joint Diseases

Lipids, especially lysophosphatidylcholine LPC16:0, have been shown to be involved in chronic joint pain through the activation of acid-sensing ion channels (ASIC3). The aim of the present study was to investigate the lipid contents of the synovial fluids from controls and patients suffering from chronic joint pain in order to identify characteristic lipid signatures associated with specific joint diseases. For this purpose, lipids were extracted from the synovial fluids and analyzed by mass spectrometry. Lipidomic analyses identified certain choline-containing lipid classes and molecular species as biomarkers of chronic joint pain, regardless of the pathology, with significantly higher levels detected in the patient samples. Moreover, correlations were observed between certain lipid levels and the type of joint pathologies. Interestingly, LPC16:0 levels appeared to correlate with the metabolic status of patients while other choline-containing lipids were more specifically associated with the inflammatory state. Overall, these data point at selective lipid species in synovial fluid as being strong predictors of specific joint pathologies which could help in the selection of the most adapted treatment.

Antibody-induced pain-like behavior and bone erosion: links to subclinical inflammation, osteoclast activity, and acid-sensing ion channel 3-dependent sensitization

ABSTRACT

Several bone conditions, eg, bone cancer, osteoporosis, and rheumatoid arthritis (RA), are associated with a risk of developing persistent pain. Increased osteoclast activity is often the hallmark of these bony pathologies and not only leads to bone remodeling but is also a source of pronociceptive factors that sensitize the bone-innervating nociceptors. Although historically bone loss in RA has been believed to be a consequence of inflammation, both bone erosion and pain can occur years before the symptom onset. Here, we have addressed the disconnection between inflammation, pain, and bone erosion by using a combination of 2 monoclonal antibodies isolated from B cells of patients with RA. We have found that mice injected with B02/B09 monoclonal antibodies (mAbs) developed a long-lasting mechanical hypersensitivity that was accompanied by bone erosion in the absence of joint edema or synovitis. Intriguingly, we have noted a lack of analgesic effect of naproxen and a moderate elevation of few inflammatory factors in the ankle joints suggesting that B02/B09-induced pain-like behavior does not depend on inflammatory processes. By contrast, we found that inhibiting osteoclast activity and acid-sensing ion channel 3 signaling prevented the development of B02/B09-mediated mechanical hypersensitivity. Moreover, we have identified secretory phospholipase A2 and lysophosphatidylcholine 16:0 as critical components of B02/B09-induced pain-like behavior and shown that treatment with a secretory phospholipase A2 inhibitor reversed B02/B09-induced mechanical hypersensitivity and bone erosion. Taken together, our study suggests a potential link between bone erosion and pain in a state of subclinical inflammation and offers a step forward in understanding the mechanisms of bone pain in diseases such as RA.

Single Subcutaneous Injection of Lysophosphatidyl-Choline Evokes ASIC3-Dependent Increases of Spinal Dorsal Horn Neuron Activity

Lysophosphatidyl-choline (LPC), a member of the phospholipid family, is an emerging player in pain. It is known to modulate different pain-related ion channels, including Acid-Sensing Ion Channel 3 (ASIC3), a cationic channel mainly expressed in peripheral sensory neurons. LPC potentiates ASIC3 current evoked by mild acidifications, but can also activate the channel at physiological pH. Very recently, LPC has been associated to chronic pain in patients suffering from fibromyalgia or osteoarthritis. Accordingly, repetitive injections of LPC within mouse muscle or joint generate both persistent pain-like and anxiety-like behaviors in an ASIC3-dependent manner. LPC has also been reported to generate acute pain behaviors when injected intraplantarly in rodents. Here, we explore the mechanism of action of a single cutaneous injection of LPC by studying its effects on spinal dorsal horn neurons. We combine pharmacological, molecular and functional approaches including in vitro patch clamp recordings and in vivo recordings of spinal neuronal activity. We show that a single cutaneous injection of LPC exclusively affects the nociceptive pathway, inducing an ASIC3-dependent sensitization of nociceptive fibers that leads to hyperexcitabilities of both high threshold (HT) and wide dynamic range (WDR) spinal neurons. ASIC3 is involved in LPC-induced increase of WDR neuron’s windup as well as in WDR and HT neuron’s mechanical hypersensitivity, and it participates, together with TRPV1, to HT neuron’s thermal hypersensitivity. The nociceptive input induced by a single LPC cutaneous rather induces short-term sensitization, contrary to previously described injections in muscle and joint. If the effects of peripheral LPC on nociceptive pathways appear to mainly depend on peripheral ASIC3 channels, their consequences on pain may also depend on the tissue injected. Our findings contribute to a better understanding of the nociceptive signaling pathway activated by peripheral LPC via ASIC3 channels, which is an important step regarding the ASIC3-dependent roles of this phospholipid in acute and chronic pain conditions.

Toll-like receptor 5 knock-out mice exhibit a specific low level of anxiety

While toll-like receptors (TLRs), which mediate innate immunity, are known to play an important role in host defense, recent work suggest their involvement in some integrated behaviors, including anxiety, depressive and cognitive functions. Here, we investigated the potential involvement of the flagellin receptor, TLR5, in anxiety, depression and cognitive behaviors using male TLR5 knock-out (KO) mice. We aobserved a specific low level of basal anxiety in TLR5 KO mice with an alteration of the hypothalamo-pituitary axis (HPA) response to acute restraint stress, illustrated by a decrease of both plasma corticosterone level and c-fos expression in the hypothalamic paraventricular nucleus where TLR5 was expressed, compared to WT littermates. However, depression and cognitive-related behaviors were not different between TLR5 KO and WT mice. Nor there were significant changes in the expression of some cytokines (IL-6, IL-10 and TNF-α) and other TLRs (TLR2, TLR3 and TLR4) in the prefrontal cortex, amygdala and hippocampus of TLR5 KO mice compared to WT mice. Moreover, mRNA expression of BDNF and glucocorticoid receptors in the hippocampus and amygdala, respectively, was not different. Finally, acute intracerebroventricular administration of flagellin, a specific TLR5 agonist, or chronic neomycin treatment did not exhibit a significant main effect, only a significant main effect of genotype was observed between TLR5 KO and WT mice. Together, those findings suggest a previously undescribed and specific role of TLR5 in anxiety and open original prospects in our understanding of the brain-gut axis function.

Clitoral reduction: Technical note

Clitoral hypertrophy is a rare genital malformation that can be congenital or acquired. In congenital forms, the most common cause is adrenal hyperplasia. The acquired forms are caused by endocrinological diseases, benign tumours or cysts. Idiopathic clitoral hypertrophies can be detected after the elimination of secondary causes. A complete assessment is needed to treat the origin of clitoridomegaly. The hypertrophy is often increased or unmasked during sexual arousal with the appearance of a true vulvar appendage in erection. It is often accompanied by a hypertrophy of the clitoral hood and can cause psychological suffering with an impact on the quality of sexual life. When the cause of clitoral hypertrophy is diagnosed, treated or stabilized, the plastic surgeon may be called upon for surgical correction. Reconstructive surgery in this area has evolved considerably since the historical clitoral amputations which led to the current technique of partial resection with sparing the dorsal neurovascular pedicle of the clitoris as described by Professor Paniel. We propose a modified conservative technique to treat clitoral hypertrophy and the clitoral hood and present two clinical cases: ventral reduction clitoridoplasty with preservation of the neurovascular pedicle associated with a chevron plasty of the clitoral hood and a lipofilling of the labia majora. The postoperative follow-up is simple with reports of great satisfaction from patients regarding their quality of life.

[Trauma and pregnancy: Is the Kleihauer-Betke test really useful?]

OBJECTIVE

To evaluate the pertinence of Kleihauer-Betke (KB) test, in case of abdominal trauma during pregnancy in forecast of fetal outcomes, according to trauma severity.

METHODS

A single-center retrospective study conducted between January 2014 and April 2016 in a maternity type III and a trauma center, which included the pregnant women admitted for abdominal trauma. The trauma's severity was assessed using the guidelines of the Society of Obstetricians and Gynaecologists of Canada. The impact of a positive KB test, defined as>0.1%, was analyzed. Adverse outcome was defined as one or more of the following complications: intrauterine fetal death, placental abruption, pre-term birth<37 weeks of gestation, and fetal or neonatal anemia.

RESULTS

During the study period, 265 pregnancies involved into an abdominal trauma were included: 69% with a minor trauma and 31% with a severe trauma. Of all patients, 5.6% presented a positive KB test, among then 15.4% had an adverse outcome. There was no significant difference in the rate of adverse outcomes in the positive KB group and the KB negative group either in the overall population (P=0.16), in the minor trauma population (P=1) or in the major trauma population (P=0.14). The predictive positive values were respectively in the global population, in the minor trauma group and in the severe trauma group 15.4%, 0% and 25%.

CONCLUSIONS

The KB test does not seem to be useful in case of trauma during pregnancy to define adverse outcome.

Effects of S 38093, an antagonist/inverse agonist of histamine H3 receptors, in models of neuropathic pain in rats

BACKGROUND

Histamine H3 receptors are mainly expressed on CNS neurons, particularly along the nociceptive pathways. The potential involvement of these receptors in pain processing has been suggested using H3 receptor inverse agonists.

METHODS

The antinociceptive effect of S 38093, a novel inverse agonist of H3 receptors, has been evaluated in several neuropathic pain models in rat and compared with those of gabapentin and pregabalin.

RESULTS

While S 38093 did not change vocalization thresholds to paw pressure in healthy rats, it exhibited a significant antihyperalgesic effect in the Streptozocin-induced diabetic (STZ) neuropathy model after acute and chronic administration and, in the chronic constriction injury (CCI) model only after chronic administration, submitted to the paw-pressure test. Acute S 38093 administration at all doses tested displayed a significant cold antiallodynic effect in a model of acute or repeated administration of oxaliplatin-induced neuropathy submitted to cold tail immersion, cold allodynia being the main side effect of oxaliplatin in patients. The effect of S 38093 increased following chronic administration (i.e. twice a day during 5 days) in the CCI and STZ models except in the oxaliplatin models where its effect was already maximal from the first administration The kinetics and size of effect of S 38093 were similar to gabapentin and/or pregabalin. Finally, the antinociceptive effect of S 38093 could be partially mediated by α2 adrenoreceptors desensitization in the locus coeruleus.

CONCLUSIONS

These results highlight the interest of S 38093 to relieve neuropathic pain and warrant clinical trials especially in chemotherapeutic agent-induced neuropathic pain.

SIGNIFICANCE

S 38093, a new H3 antagonist/inverse agonist, displays antiallodynic and antihyperalgesic effect in neuropathic pain, especially in oxaliplatin-induced neuropathy after chronic administration. This effect of S 38093 in neuropathic pain could be partly mediated by α2 receptors desensitization in the locus coeruleus.

Acid-Sensing Ion Channel 1a in the amygdala is involved in pain and anxiety-related behaviours associated with arthritis

Chronic pain is associated with anxiety and depression episodes. The amygdala plays a key role in the relationship between emotional responses and chronic pain. Here, we investigated the role of Acid-Sensing Ion Channels 1a within the basolateral amygdala (BLA), in pain and associated anxiety in a rat model of monoarthritis (MoAr). Administration within the BLA of PcTx1 or mambalgin-1, two specific inhibitors of ASIC1a-containing channels significantly inhibited pain and anxiety-related behaviours in MoAr rats. The effect of PcTx1 was correlated with a reduction of c-Fos expression in the BLA. We examined the expression profile of ASICs and other genes in the amygdala in MoAr and sham animals, and found no variation of the expression of ASIC1a, which was confirmed at the protein level. However, an increase in the BLA of MoAr rats of both PI3Kinase mRNA and the phosphorylated form of Akt, along with Bdnf mRNA, suggest that the BDNF/PI3-kinase/Akt pathway might regulate ASIC1a in BLA neurons as demonstrated in spinal sensitisation phenomenon. We also observed changes in several kinase mRNAs expression (PICK1, Sgk1) that are potentially involved in ASIC1a regulation. These results show a crucial role of ASIC1a channels in the BLA in pain and anxiety-related behaviours during arthritis.

Agomelatine: a new opportunity to reduce neuropathic pain-preclinical evidence

Antidepressants are first-line treatments of neuropathic pain but not all these drugs are really effective. Agomelatine is an antidepressant with a novel mode of action, acting as an MT1/MT2 melatonergic receptor agonist and a 5-HT2C receptor antagonist that involves indirect norepinephrine release. Melatonin, serotonin, and norepinephrine have been involved in the pathophysiology of neuropathic pain. Yet, no study has been conducted to determine agomelatine effects on neuropathic pain in animal models. Using 3 rat models of neuropathic pain of toxic (oxaliplatin/OXA), metabolic (streptozocin/STZ), and traumatic (sciatic nerve ligation/CCI [chronic constriction nerve injury]) etiologies, we investigated the antihypersensitivity effect of acute and repeated agomelatine administration. We then determined the influence of melatonergic, 5-HT2C, α-2 and β-1/2 adrenergic receptor antagonists in the antihypersensitivity effect of agomelatine. The effect of the combination of agomelatine + gabapentin was evaluated using an isobolographic approach. In STZ and CCI models, single doses of agomelatine significantly and dose dependently reduced mechanical hypersensitivity. After daily administrations for 2 weeks, this effect was confirmed in the CCI model and agomelatine also displayed a marked antihypersensitivity effect in the OXA model. The antihypersensitivity effect of agomelatine involved melatonergic, 5-HT2C, and α-2 adrenergic receptors but not beta adrenoceptors. The isobolographic analysis demonstrated that the combination of agomelatine + gabapentin had additive effects. Agomelatine exerts a clear-cut antihypersensitivity effect in 3 different neuropathic pain models. Its effect is mediated by melatonergic and 5-HT2C receptors and, although agomelatine has no affinity, also by α-2 adrenergic receptors. Finally, agomelatine combined with gabapentin produces an additive antihypersensitivity effect.

Cholinergic Neurotransmission in the Posterior Insular Cortex Is Altered in Preclinical Models of Neuropathic Pain: Key Role of Muscarinic M2 Receptors in Donepezil-Induced Antinociception

Neuropathic pain is one of the most debilitating pain conditions, yet no therapeutic strategy has been really effective for its treatment. Hence, a better understanding of its pathophysiological mechanisms is necessary to identify new pharmacological targets. Here, we report important metabolic variations in brain areas involved in pain processing in a rat model of oxaliplatin-induced neuropathy using HRMAS (1)H-NMR spectroscopy. An increased concentration of choline has been evidenced in the posterior insular cortex (pIC) of neuropathic animal, which was significantly correlated with animals' pain thresholds. The screening of 34 genes mRNA involved in the pIC cholinergic system showed an increased expression of the high-affinity choline transporter and especially the muscarinic M2 receptors, which was confirmed by Western blot analysis in oxaliplatin-treated rats and the spared nerve injury model (SNI). Furthermore, pharmacological activation of M2 receptors in the pIC using oxotremorine completely reversed oxaliplatin-induced mechanical allodynia. Consistently, systemic treatment with donepezil, a centrally active acetylcholinesterase inhibitor, prevented and reversed oxaliplatin-induced cold and mechanical allodynia as well as social interaction impairment. Intracerebral microdialysis revealed a lower level of acetylcholine in the pIC of oxaliplatin-treated rats, which was significantly increased by donepezil. Finally, the analgesic effect of donepezil was markedly reduced by a microinjection of the M2 antagonist, methoctramine, within the pIC, in both oxaliplatin-treated rats and spared nerve injury rats. These findings highlight the crucial role of cortical cholinergic neurotransmission as a critical mechanism of neuropathic pain, and suggest that targeting insular M2 receptors using central cholinomimetics could be used for neuropathic pain treatment.

SIGNIFICANCE STATEMENT

Our study describes a decrease in cholinergic neurotransmission in the posterior insular cortex in neuropathic pain condition and the involvement of M2 receptors. Targeting these cortical muscarinic M2 receptors using central cholinomimetics could be an effective therapy for neuropathic pain treatment.

99mTc-NTP 15-5 Imaging for Cartilage Involvement in Experimental Rheumatoid Arthritis: Comparison with Routinely Used Molecular Imaging Methods and Sensitivity to Chronic Nonsteroidal Antiinflammatory Drug Treatment

This study determined, using the intraarticular complete Freund adjuvant arthritis mice model, whether the radiotracer (99m)Tc-N-(triethylammonium)-3-propyl-[15]ane-N5 ((99m)Tc-NTP 15-5) targeting proteoglycans has a pathophysiologic validity for in vivo imaging of rheumatoid arthritis (RA) and its response to chronic nonsteroidal antiinflammatory drugs.

METHODS

We investigated the time course of cartilage remodeling by (99m)Tc-NTP 15-5 scintigraphy, bone damages by (99m)Tc-hydroxymethylene diphosphonate imaging, inflammation by (18)F-FDG PET, and joint proteoglycan content and pain behavior in animals, without and with meloxicam treatment. Paw circumference, thermal pain behavior, and histology as well as proteoglycan content of the whole joint were determined.

RESULTS

(99m)Tc-NTP 15-5 showed specific tracer accumulation within RA joints, with a significant increase in scintigraphic ratio observed in RA versus shams from day 3 to day 28. (18)F-FDG evidenced uptake in RA joints from day 15 to day 29. Animals treated with meloxicam (5 mg/kg) exhibited a dose-dependent decrease in both (99m)Tc-NTP 15-5 and (18)F-FDG uptake ratios versus saline-treated animals. (99m)Tc-hydroxymethylene diphosphonate bone scans were only positive at day 14 in RA versus shams, with a significant effect of meloxicam. An increase in proteoglycans of RA joint and thermal pain behavior were observed and were dose-dependently reduced by meloxicam.

CONCLUSION

These experimental results bring data in favor of the (99m)Tc-NTP 15-5 radiotracer for assessing, in vivo, cartilage remodeling in RA that could be used to monitor therapy.

Monoarthritis-induced emotional and cognitive impairments in rats are sensitive to low systemic doses or intra-amygdala injections of morphine

Chronic pain is a multidimensional experience that not only includes changes in nociception but also impairments in emotional and cognitive functions, not often taken into account in preclinical research. The present study investigated emotional and cognitive impairments in an animal model of persistent inflammatory pain as well as the involvement of the basolateral complex (BLC) of the amygdala in these components. Monoarthritis was induced by intra-articular injection of complete Freund׳s adjuvant. Mechanical hypersensitivity, anxiety and depressive-like behaviours as well as cognitive capacities were assessed using several tests, such as von Frey, social interaction, open field, saccharin preference, spatial and social recognition memory tests. The effects of morphine administered systemically or into the BLC of the amygdala were also studied. Monoarthritic rats exhibited mechanical hypersensitivity, anxiety and depressive-like behaviours as well as cognitive impairments. Whereas low systemic doses and intra-BLC infusion of morphine failed to reduce mechanical hypersensitivity, they reversed monoarthritis-induced anxiety-like behaviours and cognitive impairments. Our findings further support a crucial role of amygdala in the effect of morphine on emotional/cognitive components of pain and not on mechanical hypersensitivity. Finally, our study highlights the interest of a multi-behavioural approach in the assessment of pain and the analgesic effect of drugs.

Molecular mechanisms underlying the enhanced analgesic effect of oxycodone compared to morphine in chemotherapy-induced neuropathic pain

Oxycodone is a μ-opioid receptor agonist, used for the treatment of a large variety of painful disorders. Several studies have reported that oxycodone is a more potent pain reliever than morphine, and that it improves the quality of life of patients. However, the neurobiological mechanisms underlying the therapeutic action of these two opioids are only partially understood. The aim of this study was to define the molecular changes underlying the long-lasting analgesic effects of oxycodone and morphine in an animal model of peripheral neuropathy induced by a chemotherapic agent, vincristine. Using a behavioural approach, we show that oxycodone maintains an optimal analgesic effect after chronic treatment, whereas the effect of morphine dies down. In addition, using DNA microarray technology on dorsal root ganglia, we provide evidence that the long-term analgesic effect of oxycodone is due to an up-regulation in GABA_B receptor expression in sensory neurons. These receptors are transported to their central terminals within the dorsal horn, and subsequently reinforce a presynaptic inhibition, since only the long-lasting (and not acute) anti-hyperalgesic effect of oxycodone was abolished by intrathecal administration of a GABA_B receptor antagonist; in contrast, the morphine effect was unaffected. Our study demonstrates that the GABA_B receptor is functionally required for the alleviating effect of oxycodone in neuropathic pain condition, thus providing new insight into the molecular mechanisms underlying the sustained analgesic action of oxycodone.

PLAYING THE TRUMP OF DUALITY IN DISCUSS: UPGRADING POCER WITH QUESTIONNAIRE RESULTS

DISCUSS, the Dual Indicator Set for Sustainable Crop protection Sustainability Surveys, was designed to help farmers achieve more sustainable crop protection. The indicator set pairs risk indicators--POCER--, with response indicators--a management questionnaire. Both parts of DISCUSS are indicators in their own right, but the dual risk-response setup has the additional trump that the questionnaire reveals farm level information, by which POCER calculations are refined. Simulations with personal protection and drift mitigation measures illustrate how DISCUSS can be used to support the farmers' crop protection decisions.

Prediction of biological form at the adult stage of brown trout Salmo trutta using morphological or colorimetric criteria in migrating juveniles

To assess the correlation between four visual morphological types based on body colour and shape (fario trout, FT; shiny fario, SFT; presmolt trout, PST; typical smolt ST) of juvenile brown trout Salmo trutta during downstream spring migration and the biological form at the adult stage (river or sea), mark-recapture experiments were carried out over a period of 23 years. Evidence is provided that the visual SFT type is not a relevant one, while objective colorimetric measurements using a black basin are the best way to determine the morphological type in migrating juveniles.

Changes in obesity, cardiorespiratory fitness and habitual physical activity following a one-year intervention program in obese youth: a pilot study

AIM

The aim To assess the effects of a unique twelve month program of physical activity and health education on body mass index, cardiorespiratory fitness and physical activity habits in obese youth.

METHODS

Thirty-seven physician referred subjects, nineteen girls (12.7 ± 3.1 years) and eighteen boys (12.2 ± 2.8 years) participated in the study. Treatment consisted of a unique program of physical activity that emphasized playing games. Activity sessions were offered one time per week, two hours each session, for twelve months. A two hour health education class was provided every 3 months. Weight, height, Body Mass Index, cardiorespiratory fitness and habitual physical activity were measured.

RESULTS

Findings of the study demonstrated a significant improvement in body mass index, cardiorespiratory fitness (P<0.001), and habitual physical activity (P<0.05).

CONCLUSION

Results of the pilot study were favorable in addressing serious health issues in young obese boys and girls.

Specific involvement of atypical PKCζ/PKMζ in spinal persistent nociceptive processing following peripheral inflammation in rat

Background

Central sensitization requires the activation of various intracellular signalling pathways within spinal dorsal horn neurons, leading to a lowering of activation threshold and enhanced responsiveness of these cells. Such plasticity contributes to the manifestation of chronic pain states and displays a number of features of long-term potentiation (LTP), a ubiquitous neuronal mechanism of increased synaptic strength. Here we describe the role of a novel pathway involving atypical PKCζ/PKMζ in persistent spinal nociceptive processing, previously implicated in the maintenance of late-phase LTP.

Results

Using both behavioral tests and in vivo electrophysiology in rats, we show that inhibition of this pathway, via spinal delivery of a myristoylated protein kinase C-ζ pseudo-substrate inhibitor, reduces both pain-related behaviors and the activity of deep dorsal horn wide dynamic range neurons (WDRs) following formalin administration. In addition, Complete Freund's Adjuvant (CFA)-induced mechanical and thermal hypersensitivity was also reduced by inhibition of PKCζ/PKMζ activity. Importantly, this inhibition did not affect acute pain or locomotor behavior in normal rats and interestingly, did not inhibited mechanical allodynia and hyperalgesia in neuropathic rats. Pain-related behaviors in both inflammatory models coincided with increased phosphorylation of PKCζ/PKMζ in dorsal horn neurons, specifically PKMζ phosphorylation in formalin rats. Finally, inhibition of PKCζ/PKMζ activity decreased the expression of Fos in response to formalin and CFA in both superficial and deep laminae of the dorsal horn.

Conclusions

These results suggest that PKCζ, especially PKMζ isoform, is a significant factor involved in spinal persistent nociceptive processing, specifically, the manifestation of chronic pain states following peripheral inflammation.

Risk factors for peripheral fractures vary by age in older men--the prospective MINOS study

Identification of older men at high risk of peripheral fracture can be improved by assessing prevalent fractures (men aged ≤ 65), history of falls (men aged >65), bone width, and aortic calcifications.

INTRODUCTION

Low bone mineral density (BMD) identifies 20% of men who sustain osteoporotic fracture. We studied (1) if the assessment of bone width, aortic calcifications, prevalent falls and fractures improves identification of men at high risk of fracture and (2) if the predictive value of these parameters varies with age.

METHODS

Among 781 men aged 50 and over, 61 men sustained 66 low-trauma peripheral fractures during 10 years. History of falls and prevalent fractures was assessed by questionnaire. BMD and bone with were measured by dual X-ray absorptiometry. Abdominal aortic calcifications were assessed on the lateral radiographs of the lumbar spine.

RESULTS

Low BMD, low bone width, extended aortic calcifications, prevalent fractures (mainly multiple fractures) and frequent falls were all associated independently with higher risk of fracture. In men aged ≤ 65, prevalent fractures are associated with a significant increase in the risk of fracture (two- to threefold for one and four- to fivefold for multiple prevalent fractures). In men aged >65, history of falls is associated with a higher risk of fracture, e.g. frequent falls are associated with a sixfold increase in the risk of fracture.

CONCLUSIONS

Men aged ≤ 65 with multiple prevalent fractures and frequent fallers aged >65 are at particularly high risk of peripheral fracture regardless of BMD.

Systemic blockade of P2X3 and P2X2/3 receptors attenuates bone cancer pain behaviour in rats

Pain remains an area of considerable unmet clinical need, and this is particularly true of pain associated with bone metastases, in part because existing analgesic drugs show only limited efficacy in many patients and in part because of the adverse side effects associated with these agents. An important issue is that the nature and roles of the algogens produced in bone that drive pain-signalling systems remain unknown. Here, we tested the hypothesis that adenosine triphosphate is one such key mediator through actions on P2X3 and P2X2/3 receptors, which are expressed selectively on primary afferent nocioceptors, including those innervating the bone. Using a well-established rat model of bone cancer pain, AF-353, a recently described potent and selective P2X3 and P2X2/3 receptor antagonist, was administered orally to rats and found to produce highly significant prevention and reversal of bone cancer pain behaviour. This attenuation occurred without apparent modification of the disease, since bone destruction induced by rat MRMT-1 carcinoma cells was not significantly altered by AF-353. Using in vivo electrophysiology, evidence for a central site of action was provided by dose-dependent reductions in electrical, mechanical and thermal stimuli-evoked dorsal horn neuronal hyperexcitability following direct AF-353 administration onto the spinal cord of bone cancer animals. A peripheral site of action was also suggested by studies on the extracellular release of adenosine triphosphate from MRMT-1 carcinoma cells. Moreover, elevated phosphorylated-extracellular signal-regulated kinase expression in dorsal root ganglion neurons, induced by co-cultured MRMT-1 carcinoma cells, was significantly reduced in the presence of AF-353. These data suggest that blockade of P2X3 and P2X2/3 receptors on both the peripheral and central terminals of nocioceptors contributes to analgesic efficacy in a model of bone cancer pain. Thus, systemic P2X3 and P2X2/3 receptor antagonists with central nervous system penetration may offer a promising therapeutic tool in treating bone cancer pain.

Animal models of chemotherapy-evoked painful peripheral neuropathies

This review examines recent preclinical research on toxic peripheral neuropathy and potential therapeutic developments. Chemotherapy-induced peripheral neurotoxicity is a major clinical problem because it represents the dose-limiting side effects of a significant number of antineoplastic drugs. Patients are unable to complete full or optimal treatment schedules. The incidence of chemotherapy-induced peripheral neuropathy varies depending on the drugs and schedules used, and this can be quite high, particularly when neurophysiological methods are used to make a diagnosis. However, even when chemotherapy-induced peripheral neuropathy is not a dose-limiting side effect, its onset may severely affect the quality of life of cancer patients and cause chronic discomfort. As such, improved understanding of the pathophysiology of chemotherapy-induced neurotoxicity need for animal models is clinically relevant and will assist in the development of future neuroprotective strategies and also in the design of novel chemotherapies with improved toxicity profiles. In this review, the features of animal models of chemotherapy-induced painful neuropathy developed for 20 years, due to the administration of the most widely used drugs, such as platinum drugs, taxanes, and vinca alkaloids, will be discussed. In a second part, data available on neuroprotectants and treatment strategies, evaluated using these previous animal models in the attempt to prevent neuropathic pain, will be summarized.

[Essure implants for tubal sterilisation in France]

OBJECTIVES

Law no. 2001-588 of 4 July 2001 liberalised the practice of tubal sterilisation in France, at the same time as a new hysteroscopic method of female sterilization appeared. The growth of this method has been spurred by the reduced need for analgesia, absence of incision and scar, reduced duration of hospitalization and diminution of costs. The aim of this study was to analyse the use of the Essure procedure in France.

PATIENTS AND METHODS

This multicentre study covered seven French facilities from January 2004 through June 2006. This study included 1061 attempted placements of the Essure micro-insert, marketed by Conceptus SAS (France).

RESULTS

The first placement attempt was successful in 992 cases (94.4%). The success rate for second attempts was 59% (n = 23). Mean VAS was 3,23 +/- 0.19. Ninety-three percent of patients undergoing Essure placement were satisfied or very satisfied.

DISCUSSION AND CONCLUSION

Tubal sterilisation with Essure micro-inserts is a reliable and reproducible method that requires a short period of training. In the future, the hysteroscopic pathway will replace the laparoscopic route.

Future treatment strategies for neuropathic pain

The prevalence of people suffering from chronic pain is extremely high and pain affects millions of people worldwide. As such, persistent pain represents a major health problem and an unmet clinical need. The reason for the high incidence of chronic pain patients is in a large part due to a paucity of effective pain control. An important reason for poor pain control is undoubtedly a deficit in our understanding of the underlying causes of chronic pain and as a consequence our arsenal of analgesic therapies is limited. However, there is considerable hope for the development of new classes of analgesic drugs by targeting novel processes contributing to clinically relevant pain. In this chapter we highlight a number of molecular species which are potential therapeutic targets for future neuropathic pain treatments. In particular, the roles of voltage-gated ion channels, neuroinflammation, protein kinases and neurotrophins are discussed in relation to the generation of neuropathic pain and how by targeting these molecules it may be possible to provide better pain control than is currently available.

Effects of Etanercept and Minocycline in a rat model of spinal cord injury

Loss of function is usually considered the major consequence of spinal cord injury (SCI). However, pain severely compromises the quality of life in nearly 70% of SCI patients. The principal aim of this study was to assess the contribution of Tumor necrosis factor alpha (TNF-alpha) to SCI pain. TNF-alpha blockers have already been successfully used to treat inflammatory disorders but there are few studies on its effect on neuropathic pain, especially following SCI. Following T13 spinal cord hemisection, we examined the effects on mechanical allodynia and microglial activation of immediate and delayed chronic intrathecal treatment with etanercept, a fusion protein blocker of TNF-alpha. Immediate treatment (starting at the time of injury) with etanercept resulted in markedly reduced mechanical allodynia 1, 2, 3 and 4 weeks after SCI. Delayed treatment had no effect. Immediate etanercept treatment also reduced spinal microglial activation assessed by OX-42 immunostaining, a putative marker of activated microglia. To assess whether the effects of etanercept were mediated via decreased microglial activation, we examined the effects of the microglial inhibitor, minocycline which significantly reduced the development of pain behaviours at 1 and 2 weeks after SCI compared to saline treatment. Minocycline also significantly reduced microglial OX-42 expression. Furthermore, minocycline decreased the expression of noxious-stimulation-induced c-Fos, suggesting an effect on evoked neuronal activity. This study demonstrates that TNF-alpha plays an important role in the establishment of neuropathic pain following SCI, seemingly dependent on microglial activation. Pharmacological targeting of TNF-alpha may offer therapeutic opportunities for treating SCI pain.

Pathophysiology of peripheral neuropathic pain: immune cells and molecules

Damage to the peripheral nervous system often leads to chronic neuropathic pain characterized by spontaneous pain and an exaggerated response to painful and/or innocuous stimuli. This pain condition is extremely debilitating and usually difficult to treat. Although inflammatory and neuropathic pain syndromes are often considered distinct entities, emerging evidence belies this strict dichotomy. Inflammation is a well-characterized phenomenon, which involves a cascade of different immune cell types, such as mast cells, neutrophils, macrophages, and T lymphocytes. In addition, these cells release numerous compounds that contribute to pain. Recent evidence suggests that immune cells play a role in neuropathic pain in the periphery. In this review we identify the different immune cell types that contribute to neuropathic pain in the periphery and release factors that are crucial in this particular condition.

Inhibition of spinal microglial cathepsin S for the reversal of neuropathic pain

A recent major conceptual advance has been the recognition of the importance of immune system-neuronal interactions in the modulation of brain function, one example of which is spinal pain processing in neuropathic states. Here, we report that in peripheral nerve-injured rats, the lysosomal cysteine protease cathepsin S (CatS) is critical for the maintenance of neuropathic pain and spinal microglia activation. After injury, CatS was exclusively expressed by activated microglia in the ipsilateral dorsal horn, where expression peaked at day 7, remaining high on day 14. Intrathecal delivery of an irreversible CatS inhibitor, morpholinurea-leucine-homophenylalanine-vinyl phenyl sulfone (LHVS), was antihyperalgesic and antiallodynic in neuropathic rats and attenuated spinal microglia activation. Consistent with a pronociceptive role of endogenous CatS, spinal intrathecal delivery of rat recombinant CatS (rrCatS) induced hyperalgesia and allodynia in naïve rats and activated p38 mitogen-activated protein kinase (MAPK) in spinal cord microglia. A bioinformatics approach revealed that the transmembrane chemokine fractalkine (FKN) is a potential substrate for CatS cleavage. We show that rrCatS incubation reduced the levels of cell-associated FKN in cultured sensory neurons and that a neutralizing antibody against FKN prevented both FKN- and CatS-induced allodynia, hyperalgesia, and p38 MAPK activation. Furthermore, rrCatS induced allodynia in wild-type but not CX3CR1-knockout mice. We suggest that under conditions of increased nociception, microglial CatS is responsible for the liberation of neuronal FKN, which stimulates p38 MAPK phosphorylation in microglia, thereby activating neurons via the release of pronociceptive mediators.

Chondroitinase ABC promotes sprouting of intact and injured spinal systems after spinal cord injury

Chondroitin sulfate proteoglycans (CSPGs) are inhibitory extracellular matrix molecules that are upregulated after CNS injury. Degradation of CSPGs using the enzyme chondroitinase ABC (ChABC) can promote functional recovery after spinal cord injury. However, the mechanisms underlying this recovery are not clear. Here we investigated the effects of ChABC treatment on promoting plasticity within the spinal cord. We found robust sprouting of both injured (corticospinal) and intact (serotonergic) descending projections as well as uninjured primary afferents after a cervical dorsal column injury and ChABC treatment. Sprouting fibers were observed in aberrant locations in degenerating white matter proximal to the injury in regions where CSPGs had been degraded. Corticospinal and serotonergic sprouting fibers were also observed in spinal gray matter at and below the level of the lesion, indicating increased innervation in the terminal regions of descending projections important for locomotion. Spinal-injured animals treated with a vehicle solution showed no significant sprouting. Interestingly, ChABC treatment in uninjured animals did not induce sprouting in any system. Thus, both denervation and CSPG degradation were required to promote sprouting within the spinal cord. We also examined potential detrimental effects of ChABC-induced plasticity. However, although primary afferent sprouting was observed after lumbar dorsal column lesions and ChABC treatment, there was no increased connectivity of nociceptive neurons or development of mechanical allodynia or thermal hyperalgesia. Thus, CSPG digestion promotes robust sprouting of spinal projections in degenerating and denervated areas of the spinal cord; compensatory sprouting of descending systems could be a key mechanism underlying functional recovery.

The use of a decremental dose regimen in patients treated with a chronic low-dose step-up protocol for WHO Group II anovulation: a prospective randomized multicentre study

BACKGROUND

In women with chronic anovulation, the choice of the FSH starting dose and the modality of subsequent dose adjustments are critical in controlling the risk of overstimulation. The aim of this prospective randomized study was to assess the efficacy and safety of a decremental FSH dose regimen applied once the leading follicle was 10-13 mm in diameter in women treated for WHO Group II anovulation according to a chronic low-dose (CLD; 75 IU FSH for 14 days with 37.5 IU increment) step-up protocol.

METHODS

Two hundred and nine subfertile women were treated with recombinant human FSH (r-hFSH) (Gonal-f) for ovulation induction according to a CLD step-up regimen. When the leading follicle reached a diameter of 10-13 mm, 158 participants were randomized by means of a computer-generated list to receive either the same FSH dose required to achieve the threshold for follicular development (CLD regimen) or half of this FSH dose [sequential (SQ) regimen]. HCG was administered only if not more than three follicles >or=16 mm in diameter were present and/or serum estradiol (E(2)) values were <1200 pg/ml. The primary outcome measure was the number of follicles >or=16 mm in size at the time of hCG administration.

RESULTS

Clinical characteristics and ovarian parameters at the time of randomization were similar in the two groups. Both CLD and SQ protocols achieved similar follicular growth as regards the total number of follicles and medium-sized or mature follicles (>/=16 mm: 1.5 +/- 0.9 versus 1.4 +/- 0.7, respectively). Furthermore, serum E(2) levels were equivalent in the two groups at the time of hCG administration (441 +/- 360 versus 425 +/- 480 pg/ml for CLD and SQ protocols, respectively). The rate of mono-follicular development was identical as well as the percentage of patients who ovulated and achieved pregnancy.

CONCLUSIONS

The results show that the CLD step-up regimen for FSH administration is efficacious and safe for promoting mono-follicular ovulation in women with WHO Group II anovulation. This study confirms that maintaining the same FSH starting dose for 14 days before increasing the dose in step-up regimen is critical to adequately control the risk of over-response. Strict application of CLD regimen should be recommended in women with WHO Group II anovulation.

Rapid co-release of interleukin 1beta and caspase 1 in spinal cord inflammation

Mounting evidence supports the hypothesis that pro-inflammatory cytokines secreted by astrocytes and microglia modulate nociceptive function in the injured CNS and following peripheral nerve damage. Here we examine the involvement of interleukin-1beta (IL-1beta) and microglia activation in nociceptive processing in rat models of spinal cord inflammation. Following application of lipopolysaccharide (LPS) to an ex vivo dorsal horn slice preparation, we observed rapid secretion of IL-1beta which was prevented by inhibition of glial cell metabolism and by inhibitors of either p38 mitogen-activated protein kinase (MAPK) or caspase 1. LPS superfusion also induced rapid secretion of active caspase 1 and apoptosis-associated speck-like protein containing a caspase recruitment domain from the isolated dorsal horn. Extensive microglial cell activation in the dorsal horn, as determined by immunoreactivity for phosphorylated p38 MAPK, was found to correlate with the occurrence of IL-1beta secretion. In behavioural studies, intrathecal injection of LPS in the lumbar spinal cord produced mechanical hyperalgesia in the rat hind-paws which was attenuated by concomitant injections of a p38 MAPK inhibitor, a caspase 1 inhibitor or the rat recombinant interleukin 1 receptor antagonist. These data suggest a critical role for the cytokine IL-1beta and caspase 1 rapidly released by activated microglia in enhancing nociceptive transmission in spinal cord inflammation.