IoT Registration and Authentication in Smart City Applications with Blockchain.

The advent of 5G will bring a massive adoption of IoT devices across our society. IoT Applications (IoT Apps) will be the primary data collection base. This scenario leads to unprecedented scalability and security challenges, with one of the first areas for these applications being Smart Cities (SC). IoT devices in new network paradigms, such as Edge Computing and Fog Computing, will collect data from urban environments, providing real-time management information. One of these challenges is ensuring that the data sent from Edge Computing are reliable. Blockchain has been a technology that has gained the spotlight in recent years, due to its robust security in fintech and cryptocurrencies. Its strong encryption and distributed and decentralized network make it potential for this challenge. Using Blockchain with IoT makes it possible for SC applications to have security information distributed, which makes it possible to shield against Distributed Denial of Service (DDOS). IoT devices in an SC can have a long life, which increases the chance of having security holes caused by outdated firmware. Adding a layer of identification and verification of attributes and signature of messages coming from IoT devices by Smart Contracts can bring confidence in the content. SC Apps that extract data from legacy and outdated appliances, installed in inaccessible, unknown, and often untrusted urban environments can benefit from this work. Our work's main contribution is the development of API Gateways to be used in IoT devices and network gateway to sign, identify, and authorize messages. For this, keys and essential characteristics of the devices previously registered in Blockchain are used. We will discuss the importance of this implementation while considering the SC and present a testbed that is composed of Blockchain Ethereum and real IoT devices. We analyze the transfer time, memory, and CPU impacts during the sending and processing of these messages. The messages are signed, identified, and validated by our API Gateways and only then collected for an IoT data management application.

The nuclear receptors PXR and LXR are regulators of the scaffold protein PDZK1.

PDZK1 (NHERF3) interacts with membrane proteins whereby modulating their spatial arrangement, membrane stability, and function. One of the membrane proteins shown to be stabilized by interaction with PDZK1 is the HDL-receptor SR-BI (SCARB1). Testing the influence of TO 901317, a known activator of liver X receptor alpha (LXRα, NR1H3) which is a central regulator of the lipid homeostasis, Grefhorst et al. reported in 2012 that administration of TO 901317 did not affect PDZK1 expression and reduced the amount of SR-BI protein in mouse liver. Considering that TO 901317 also activates the xenosensor pregnane X receptor (PXR, NR1I2), it was aim of this study to further investigate the influence of LXRα and PXR activation on transcription of PDZK1. First, we tested the transactivation of PDZK1 by LXRα or PXR in cell-based reporter gene assays comparing the effect of prototypical ligands to that of TO 901317. Ligand mediated activation of LXRα increased, while that of PXR lowered luciferase activity. Further, we located the most likely binding site for LXRα and PXR on the PDZK1 promoter between -85 bp and -54 bp. The transcriptional regulation by LXRα was further supported showing enhanced mRNA expression of PDZK1 in HepG2 cells treated with the selective LXRα-agonist GW3965, while treatment with TO 901317 reduced the protein amount of PDZK1. Taken together, we provide evidence that both LXRα and PXR are transcriptional regulators of PDZK1 supporting the previous notion that the scaffold protein is part of cholesterol homeostasis and drug metabolism.

Thyroid Hormones Are Transport Substrates and Transcriptional Regulators of Organic Anion Transporting Polypeptide 2B1.

Levothyroxine replacement therapy forms the cornerstone of hypothyroidism management. Variability in levothyroxine oral absorption may contribute to the well-recognized large interpatient differences in required dose. Moreover, levothyroxine-drug pharmacokinetic interactions are thought to be caused by altered oral bioavailability. Interestingly, little is known regarding the mechanisms contributing to levothyroxine absorption in the gastrointestinal tract. Here, we aimed to determine whether the intestinal drug uptake transporter organic anion transporting polypeptide 2B1 (OATP2B1) may be involved in facilitating intestinal absorption of thyroid hormones. We also explored whether thyroid hormones regulate OATP2B1 gene expression. In cultured Madin-Darby Canine Kidney II/OATP2B1 cells and in OATP2B1-transfected Caco-2 cells, thyroid hormones were found to inhibit OATP2B1-mediated uptake of estrone-3-sulfate. Competitive counter-flow experiments evaluating the influence on the cellular accumulation of estrone-3-sulfate in the steady state indicated that thyroid hormones were substrates of OATP2B1. Additional evidence that thyroid hormones were OATP2B1 substrates was provided by OATP2B1-dependent stimulation of thyroid hormone receptor activation in cell-based reporter assays. Bidirectional transport studies in intestinal Caco-2 cells showed net absorptive flux of thyroid hormones, which was attenuated by the presence of the OATP2B1 inhibitor, atorvastatin. In intestinal Caco-2 and LS180 cells, but not in liver Huh-7 or HepG2 cells, OATP2B1 expression was induced by treatment with thyroid hormones. Reporter gene assays revealed thyroid hormone receptor α-mediated transactivation of the SLCO2B1 1b and the SLCO2B1 1e promoters. We conclude that thyroid hormones are substrates and transcriptional regulators of OATP2B1. These insights provide a potential mechanistic basis for oral levothyroxine dose variability and drug interactions.

The scaffold protein PDZK1 modulates expression and function of the organic anion transporting polypeptide 2B1.

The protein family of Organic Anion Transporting Polypeptides (OATPs) summarizes various transporters known to facilitate cellular uptake of xenobiotics. One member of this family is OATP2B1. This transporter is ubiquitously expressed and possesses a PDZ-binding motif at the C-terminus. PDZK1 (PDZ domain-containing 1) is a scaffold protein that influences function of different membrane proteins by sorting/stabilization of their membrane localization. It was aim of the herein reported study to investigate whether there is an interaction between OATP2B1 and PDZK1, and to further characterize its impact on transport function. At first expression of both OATP2B1 and PDZK1 was evaluated in liver, kidney and intestine. Based on the existence of a C-terminal PDZ-class I binding motif in OATP2B1 and the co-expression in all tested tissues an interaction was likely. Testing the influence of PDZK1 on OATP2B1 transport function revealed enhanced transport capacity for estrone 3-sulfate, thereby suggesting a change in OATP2B1 amount in the membrane. This assumption was validated by Western blot analysis. Finally, deletion of the C-terminal PDZ-binding motif in OATP2B1 lowered the impact of PDZK1 on transport function. Taken together, we report an interaction of PDZK1 with OATP2B1, which influences localization and function of the transporter. Changes in PDZK1 expression may therefore be one factor contributing to interindividual differences in OATP2B1 mediated pharmacokinetic processes.

PDZ domain containing protein 1 (PDZK1), a modulator of membrane proteins, is regulated by the nuclear receptor THRß.

Genome wide association studies revealed single nucleotide polymorphisms (SNP) located within the promoter of PDZ domain containing protein 1 (PDZK1) to be associated with serum uric acid levels. Since modulation of transporters and particularly of membrane proteins involved in uric acid handling by PDZK1 has previously been reported, the aim of this study was to analyze the impact of the polymorphisms rs1967017, rs1471633, and rs12129861 on promoter activity and thereby transcription of PDZK1. Cell-based reporter gene assays showed transactivation of the PDZK1-promoter by triiodothyronine mediated by thyroid hormone receptors (THR) α and ß. In silico analysis verified localization of the polymorphism rs1967017 within the most likely THR binding site whose deletion reduced THR-mediated transactivation. Furthermore, our study shows regulation of PDZK1 by thyroid hormones, thereby providing a mechanistic basis for the previously reported associations between thyroid hormone status and uric acid homeostasis.

Regulation of PDZ domain-containing 1 (PDZK1) expression by hepatocyte nuclear factor-1α (HNF1α) in human kidney.

In the renal proximal tubule the secretion and reabsorption of glomerularly filtrated compounds is realized by a functional network of uptake and efflux transporters. The activity and localization of several transporters expressed at the apical tubular membrane are regulated by the membrane-associated protein PDZ domain-containing 1 (PDZK1). We aimed to characterize the transcriptional regulation of this modulator of renal transport. Coexpression analyses of PDZK1 and putative regulators were performed using human kidney samples. Protein and mRNA expression of PDZK1 in renal proximal tubule epithelial cells after adenoviral transfer and siRNA knockdown of transcription factor hepatocyte nuclear factor-1α (HNF1α) was assessed by quantitative real-time PCR and Western blot analysis. Transactivation of the PDZK1 promoter was quantified in cell-based reporter gene assays. Subsequently, the binding of HNF1α to the PDZK1 promoter was verified by in silico analyses and chromatin immunoprecipitation assay. HNF1α positively regulated the promoter activity of PDZK1. Adenoviral overexpression of HNF1α in renal proximal tubule epithelial cells (RPTEC) increased PDZK1 mRNA and protein expression, whereas siRNA knockdown of HNF1α resulted in decreased expression of PDZK1. Our results show that HNF1α, which has previously been described as a modulator of several transporters of the renal transportosome, is also a key determinant of PDZK1 transcription.

Cannabidiol and endogenous opioid peptide-mediated mechanisms modulate antinociception induced by transcutaneous electrostimulation of the peripheral nervous system.

Transcutaneous electrical nerve stimulation (TENS) is a non-pharmacological therapy for the treatment of pain. The present work investigated the effect of cannabidiol, naloxone and diazepam in combination with 10 Hz and 150 Hz TENS. Male Wistar rats were submitted to the tail-flick test (baseline), and each rodent received an acute administration (intraperitoneal) of naloxone (3.0mg/kg), diazepam (1.5mg/kg) or cannabidiol (0.75 mg/kg, 1.5mg/kg, 3.0mg/kg, 4.5mg/kg, 6.0mg/kg and 12.0mg/kg); 10 min after the acute administration, 10 Hz or 150 Hz TENS or a sham procedure was performed for 30 min. Subsequently, tail-flick measures were recorded over a 90-min period, at 5-min intervals. 10 Hz TENS increased the nociceptive threshold during the 90-min period. This antinociceptive effect was reversed by naloxone pre-treatment, was not altered by diazepam pre-treatment and was abolished by cannabidiol pre-treatment (1.5mg/kg). Moreover, 150 Hz TENS increased tail-flick latencies by 35 min post-treatment, which was partially inhibited by naloxone pre-treatment and totally inhibited by cannabidiol (1.5mg/kg). These data suggest the involvement of the endogenous opioid system and the cannabinoid-mediated neuromodulation of the antinociception induced by transcutaneous electrostimulation at 10 Hz and 150 Hz TENS.

Evaluation of the noradrenergic pathway and alpha-2 and beta-receptors in the modulation of the analgesia induced by transcutaneous electric nerve stimulation of high and low frequencies / Evaluación de la vía noradrenérgica y de los receptores alfa-2 y beta en la modulación de analgesia inducida por la estimulación eléctrica nerviosa transcutánea con alta y baja frecuencia / Avaliação da via noradrenérgica e dos receptores alfa-2 e beta na modulação da analgesia induzida pela estimulação elétrica nervosa transcutânea de alta e de baixa frequência

Transcutaneous electric nerve stimulation is a noninvasive method used in clinical Physiotherapy to control acute or chronic pain. Different theories have been proposed to explain the mechanism of the analgesic action of transcutaneous electric nerve stimulation, as the participation of central and peripheral neurotransmitters. The aim of this study was to evaluate the involvement of noradrenergic pathway and of the receptors alfa-2 and beta in the modulation of analgesia produced by transcutaneous electric nerve stimulation of high and low frequency in Wistar rats after chronic treatment with propranolol or yohimbine intraperitoneally. Animals weighing 200 to 300 g were divided into 9 groups (n=8), which were obtained nociceptive thresholds through the Tail Flick before and after application of TENS for comparing the change of pain. The administration of yohimbine or propranolol at a dose of 3 mg/kg was effective in antagonizing the analgesia induced by high (150 Hz) and low (10 Hz) frequency transcutaneous electric nerve stimulation according to ANOVA test followed by Duncan post hoc test (p<0.05). Thus, it is suggested the involvement of alpha-2 and beta noradrenergic receptors in the modulation of transcutaneous electric nerve stimulation-induced analgesia.

La estimulación eléctrica nerviosa transcutánea es un método no invasivo utilizado en la clínica de Fisioterapia para controlar el dolor agudo y crónico. Diversas teorías son propuestas para explanar el mecanismo de acción analgésico de la estimulación eléctrica nerviosa transcutánea, como la participación de neurotransmisores centrales y periféricos. El objetivo del presente estudio fue evaluar la participación de la vía noradrenérgica y de los receptores alfa-2 y beta en la modulación de analgesia inducida por la estimulación eléctrica nerviosa transcutánea con alta y baja frecuencia en ratos del tipo Wistar, después del tratamiento crónico con yohimbina o propranolol por la vía intraperitoneal. Animales que pesaban 200 y 300 g fueron divididos en nueve grupos (n=8), por los cuales fueron obtenidos los umbrales nociceptivos por medio del Tail Flick, antes y después de la aplicación de la estimulación eléctrica nerviosa transcutánea con el intuito de comparar la alteración del cuadro álgico. La administración de yohimbina o propranolol en el dosis de 3 mg/kg fue eficaz en resultar en una antagonización de analgesia inducida por la estimulación eléctrica nerviosa transcutánea con alta (150 Hz) y baja (10 Hz) frecuencia, de acuerdo al test de ANOVA seguido del test post-hoc de Duncan (p>0,05). Por lo tanto, se sugiere el envolvimiento de los receptores noradrenergicos alfa-2 y beta en la modulación de analgesia inducida por la estimulación eléctrica nerviosa transcutánea.

Estimulação elétrica nervosa transcutânea é um método não invasivo utilizado na clínica de Fisioterapia para controlar dores aguda ou crônica. Diferentes teorias são propostas para explicar o mecanismo de ação analgésica da estimulação elétrica nervosa transcutânea, como a participação de neurotransmissores centrais e periféricos. O objetivo do presente estudo foi avaliar a participação da via noradrenérgica e dos receptores alfa-2 e beta na modulação da analgesia induzida pela estimulação elétrica nervosa transcutânea de alta e baixa frequência em ratos Wistar, após tratamento crônico com ioimbina ou propranolol por via intraperitoneal. Animais pesando entre 200 e 300 g foram divididos em 9 grupos (n=8), dos quais se obteve os limiares nociceptivos por meio do Tail Flick antes e após a aplicação da estimulação elétrica nervosa transcutânea para comparação de mudança do quadro álgico. A administração de ioimbina ou de propranolol na dose de 3 mg/kg foi efetiva em causar uma antagonização da analgesia induzida pela estimulação elétrica nervosa transcutânea de alta (150 Hz) e baixa frequência (10 Hz) segundo teste ANOVA seguido do teste post hoc Duncan (p<0,05). Dessa forma, sugere-se o envolvimento de receptores noradrenérgicos alfa-2 e beta na modulação da analgesia induzida pela estimulação elétrica nervosa transcutânea. .

Paradoxical effect of noradrenaline-mediated neurotransmission in the antinociceptive phenomenon that accompanies tonic-clonic seizures: role of locus coeruleus neurons and α(2)- and ß-noradrenergic receptors.

The postictal state is generally followed by antinociception. It is known that connections between the dorsal raphe nucleus, the periaqueductal gray matter, and the locus coeruleus, an important noradrenergic brainstem nucleus, are involved in the descending control of ascending nociceptive pathways. The aim of the present study was to determine whether noradrenergic mechanisms in the locus coeruleus are involved in postictal antinociception. Yohimbine (an α(2)-receptor antagonist) or propranolol (a ß-receptor antagonist) was microinjected unilaterally into the locus coeruleus, followed by intraperitoneal administration of pentylenetetrazole (PTZ), a noncompetitive antagonist that blocks GABA-mediated Cl(-) influx. Although the administration of both yohimbine and propranolol to the locus coeruleus/subcoeruleus area resulted in a significant decrease in tonic or tonic-clonic seizure-induced antinociception, the effect of yohimbine restricted to the locus coeruleus was more distinct compared with that of propranolol, possibly because of the presynaptic localization of α(2)-noradrenergic receptors in locus coeruleus neurons. These effects were related to the modulation of noradrenergic activity in the locus coeruleus. Interestingly, microinjections of noradrenaline into the locus coeruleus also decrease the postictal antinociception. The present results suggest that the mechanism underlying postictal antinociception involves both α(2)- and ß-noradrenergic receptors in the locus coeruleus, although the action of noradrenaline on these receptors causes a paradoxical effect, depending on the nature of the local neurotransmission.

5-HT1A/1B, 5-HT6, and 5-HT7 serotonergic receptors recruitment in tonic-clonic seizure-induced antinociception: role of dorsal raphe nucleus.

Pharmacological studies have been focused on the involvement of different neural pathways in the organization of antinociception that follows tonic-clonic seizures, including 5-hydroxytryptamine (5-HT)-, norepinephrine-, acetylcholine- and endogenous opioid peptide-mediated mechanisms, giving rise to more in-depth comprehension of this interesting post-ictal antinociceptive phenomenon. The present work investigated the involvement of 5-HT(1A/1B), 5-HT(6), and 5-HT(7) serotonergic receptors through peripheral pretreatment with methiothepin at doses of 0.5, 1.0, 2.0 and 3.0 mg/kg in the organization of the post-ictal antinociception elicited by pharmacologically (with pentylenetetrazole at 64 mg/kg)-induced tonic-clonic seizures. Methiothepin at 1.0 mg/kg blocked the post-ictal antinociception recorded after the end of seizures, whereas doses of 2.0 and 3.0 mg/kg potentiated the post-ictal antinociception. The nociceptive thresholds were kept higher than those of the control group. However, when the same 5-hydroxytryptamine receptors antagonist was microinjected (at 1.0, 3.0 and 5.0 microg/0.2 microL) in the dorsal raphe nucleus, a mesencephalic structure rich in serotonergic neurons and 5-HT receptors, the post-ictal hypo-analgesia was consistently antagonized. The present findings suggest a dual effect of methiothepin, characterized by a disinhibitory effect on the post-ictal antinociception when peripherally administered (possibly due to an antagonism of pre-synaptic 5-HT(1A) serotonergic autoreceptors in the pain endogenous inhibitory system) and an inhibitory effect (possibly due to a DRN post-synaptic 5-HT(1B), 5-HT(6), and 5-HT(7) serotonergic receptors blockade) when centrally administered. The present data also suggest that serotonin-mediated mechanisms of the dorsal raphe nucleus exert a key-role in the modulation of the post-ictal antinociception.

Involvement of 5-HT(2) serotonergic receptors of the nucleus raphe magnus and nucleus reticularis gigantocellularis/paragigantocellularis complex neural networks in the antinociceptive phenomenon that follows the post-ictal immobility syndrome.

The post-ictal immobility syndrome is followed by a significant increase in the nociceptive thresholds in animals and men. In this interesting post-ictal behavioral response, endogenous opioid peptides-mediated mechanisms, as well as cholinergic-mediated antinociceptive processes, have been suggested. However, considering that many serotonergic descending pathways have been implicated in antinociceptive reactions, the aim of the present work is to investigate the involvement of 5-HT(2)-serotonergic receptor subfamily in the post-ictal antinociception. The analgesia was measured by the tail-flick test in seven or eight Wistar rats per group. Convulsions were followed by statistically significant increase in the tail-flick latencies (TFL), at least for 120 min of the post-ictal period. Male Wistar rats were submitted to stereotaxic surgery for introduction of a guide-cannula in the rhombencephalon, aiming either the nucleus raphe magnus (NRM) or the gigantocellularis complex. In independent groups of animals, these nuclei were neurochemically lesioned with a unilateral microinjection of ibotenic acid (1.0 microg/0.2 microL). The neuronal damage of either the NRM or nucleus reticularis gigantocellularis/paragigantocellularis complex decreased the post-ictal analgesia. Also, in other independent groups, central administration of ritanserin (5.0 microg/0.2 microL) or physiological saline into each of the reticular formation nuclei studied caused a statistically significant decrease in the TFL of seizing animals, as compared to controls, in all post-ictal periods studied. These results indicate that serotonin input-connected neurons of the pontine and medullarly reticular nuclei may be involved in the post-ictal analgesia.

Descriptive and functional neuroanatomy of locus coeruleus-noradrenaline-containing neurons involvement in bradykinin-induced antinociception on principal sensory trigeminal nucleus.

The present study was carried out in Wistar rats, using the jaw-opening reflex and dental pulp stimulation, to investigate noradrenaline- and serotonin-mediated antinociceptive circuits. The effects of microinjections of bradykinin into the principal sensory trigeminal nucleus (PSTN) before and after neurochemical lesions of the locus coeruleus noradrenergic neurons were studied. Neuroanatomical experiments showed evidence for reciprocal neuronal pathways connecting the locus coeruleus (LC) to trigeminal sensory nuclei and linking monoaminergic nuclei of the pain inhibitory system to spinal trigeminal nucleus (STN). Fast blue (FB) injections in the locus coeruleus/subcoeruleus region retrogradely labeled neurons in the contralateral PSTN and LC. Microinjections of FB into the STN showed neurons labeled in both ipsilateral and contralateral LC, as well as in the ipsilateral Barrington's nucleus and subcoeruleus area. Retrograde tract-tracing with FB also showed that the mesencephalic trigeminal nucleus sends neural pathways towards the ipsilateral PSTN, with outputs from cranial and caudal aspects of the brainstem. In addition, neurons from the lateral and dorsolateral columns of periaqueductal gray matter also send outputs to the ipsilateral PSTN. Microinjections of FB in the interpolar and caudal divisions of the STN labeled neurons in the caudal subdivision of STN. Microinjections in the STN interpolar and caudal divisions also retrogradely labeled serotonin- and noradrenaline-containing nucleus of the brainstem pain inhibitory system. Finally, the gigantocellularis complex (nucleus reticularis gigantocellularis/paragigantocellularis), nucleus raphe magnus and nucleus raphe pallidus also projected to the caudal divisions of the STN. Microinjections of bradykinin in the PSTN caused a statistically significant long-lasting antinociception, antagonized by the damage of locus coeruleus-noradrenergic neuronal fibres with (N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine) (DSP4), a neurotoxin that specifically depleted noradrenaline from locus coeruleus terminal fields. These data suggest that serotonin- and noradrenaline-containing nuclei of the endogenous pain inhibitory system exert a key-role in the antinociceptive mechanisms of bradykinin and the locus coeruleus is crucially involved in this effect.

Dorsal raphe nucleus and locus coeruleus neural networks and the elaboration of the sweet-substance-induced antinociception.

In order to investigate the effects of monoaminergic neurons of the dorsal raphe nucleus (DRN) and locus coeruleus (LC) on the elaboration and control of sweet-substance-induced antinociception, male albino Wistar rats weighing 180-200 g received sucrose solution (250 g/L) for 7-14 days as their only source of liquid. After the chronic consumption of sucrose solution, each animal was pretreated with unilateral microinjection of ibotenic acid (1.0 microg/0.2 microL) in the DRN or in the LC. The tail withdrawal latencies of the rats in the tail-flick test were measured immediately before and 7 days after this treatment. The neurochemical lesion of locus coeruleus, but not of DRN neural networks with ibotenic acid, after the chronic intake of sweetened solution, decreased the sweet-substance-induced antinociception. These results indicate the involvement of noradrenaline-containing neurons of the LC in the sucrose-induced antinociception. We also consider the possibility of DRN serotonergic neurons exerting some inhibitory effect on the LC neural networks involved with the elaboration of the sweet-substance-induced antinociception.

Intrinsic neural circuits between dorsal midbrain neurons that control fear-induced responses and seizure activity and nuclei of the pain inhibitory system elaborating postictal antinociceptive processes: a functional neuroanatomical and neuropharmacological study.

The blockade of GABA-mediated Cl(-) influx with pentylenetetrazol (PTZ) was used in the present work to induce seizures in Rattus norvegicus. The aim of this work was to study the involvement of monoamines in the antinociception induced by convulsions elicited by peripheral administration of PTZ (64 mg/kg). The analgesia was measured by the tail-flick test in seven or eight Wistar rats per group. Convulsions were followed by statistically significant increase in the tail-flick latencies (TFL), at least for 120 min of the postictal period. Peripheral administration of methysergide (0.5, 1, 2, and 3 mg/kg) caused a significant decrease in the TFL in seizing animals, as compared to controls, in all postictal periods studied. These findings were corroborated by the pretreatment with ketanserin, a 5-HT(2A/2C)-serotonergic/alpha(1)-noradrenergic receptors antagonist, at the same doses. Peripheral administration of yohimbine (0.5, 1, 2, and 3 mg/kg), alpha(2)-noradrenergic antagonist, also decreased the postictal analgesia either at initial or more terminal periods of the postictal analgesia. These data were corroborated with peripheral administrations of propranolol, a beta-noradrenergic receptor blocker that caused a decrease in the postictal analgesia consistently in later stages (after the first 20-min post-tonic-clonic convulsive reactions) of the post-seizure analgesia, except for the highest dose. These results indicate that monoamines may be involved in the postictal analgesia. The blockade of 5-HT(2A/2C)-serotoninergic, alpha(1)-noradrenergic, or alpha(2)-noradrenergic receptors before tonic clonic seizure-induced analgesia antagonized the increase in the nociceptive threshold caused by seizures in initial steps of the temporal antinociceptive curve, as compared to the blockade of beta-noradrenergic ones. These findings suggest that the recruitment of alpha-noradrenergic receptor and serotonergic receptors was made immediately after convulsions and in other initial periods of the postictal analgesia, as compared to the involvement of beta-noradrenergic receptor. Neurochemical lesions of the locus coeruleus (LC) and neuronal damage of the dorsal raphe nucleus induced a significant decrease of the postictal analgesia, suggesting the involvement of these nuclei in this antinociceptive process. The functional neuroanatomical study of the neural link between the mesencephalic tectum and nuclei of the central pain inhibitory system showed evidence for the interconnection between superior colliculus, both dorsal and ventral periaqueductal gray matter (PAG), and inferior colliculus. Defensive substrates of the inferior colliculus, also involved with wild running and epilepsy, send inputs toward dorsal raphe nucleus and locus coeruleus. Since these nuclei are rich in monoamines and send neural connections toward other monoaminergic nuclei of the brainstem involved with the control of the nociceptive inputs in the dorsal horn of the spinal cord, the present results offer a neuroanatomical and psychopharmacological basis for the antinociceptive processes following tonic-clonic seizures.

Estudo do envolvimento de vias oradrenérgicas, e de receptores alfa beta das redes neurais do locus coeruleus na analgesia pós-ictal

Tem sido proposto que o estado pós-ictal geralmente é seguido de antinocicepção. Alguns trabalhos descrevem que este comportamento é eliciado pela estimulação de estruturas localizadas no tronco encefálico, como o núcleo dorsal da rafe, magno da rafe, gigantocelular e substância cinzenta periaquedutal, profundamente interconectados, através de uma via endógena inibitória da dor, que integra várias redes neurais em seu percurso descendente. Com efeito, demonstrou-se que há conexões entre o núcleo magno da rafe e a substância cinzenta periaquedutal com o locus coeruleus e, considerando ser este núcleo majoritariamente noradrenérgico, se aceita amplamente que tais neurônios monoaminérgicos participam na modulação da dor, exercendo um importante controle descendente da via nociceptiva ascendente. Nesse trabalho, objetivou-se estudar aspectos da neuroquímica da analgesia induzida por convulsões produzidas por drogas, utilizando-se lesão neurotóxica (ácido ibotênico) do locus coeruleus (LC). Também foi investigado o papel do mecanismo noradrenérgico neste processo antinociceptivo, com a administração de antagonistas noradrenérgicos -ioimbina (alfa IND.2) e propranolol (beta) -por via intraperitonial e central tendo esta, por alvo, as redes neurais do locus coeruleus. O pentilenotetrazol (PTZ), um antagonista não-competitivo, que impede o influxo de Cl POT. - mediado pelo GABA, foi usado em um modelo experimental de crises convulsivas para avaliar as características neuroquímicas da analgesia pós ictal. As lesões no locus coeruleus, com ácido ibotênico causaram uma diminuição estatisticamente significante da analgesia pós-ictal em todos os animais estudados, quando comparado ao grupo controle. A administração dos antagonistas noradrenérgicos ioimbina (alfa IND.2) e propanolol (beta), tanto por via intraperitonial, quanto central, produziu uma redução estatisticamente significante na analgesia...(AU)

Artroplastia total em quadril anquilosado / Total arthroplasty in the ankylosed hip

No período de fevereiro de 1990 a setembro de 1992, 11 pacientes com quadris anquilosados foram submetidos a 14 artroplastias totais. Todos foram reavaliados clínica e radiologicamente, com seguimento médio de 28 meses. As análises realizadas subjetiva e objetivamente, segundo o método de Merle D'Aubigné & Postel, mostraram em sua maioria bons resultados.