Enfrentamiento de la anafilaxia en el servicio de urgencia / Approach of Anaphylaxis in the emergency room

La anafilaxia es una reacción en su mayoría de hipersensibilidad tipo I, que estimula la activación generalizada de mastocitos, y provoca un cuadro clínico multisistémico que puede ser fatal. Se estima que tiene una incidencia de 0,03-0,1% y una prevalencia de vida de 0,5-2% en la población general. Generalmente, la reacción inmunológica ocurre posterior a la ingesta de alimentos, uso de medicamentos o picaduras de insectos, pero también se han descrito mecanismos no inmunológicos (no IgE) que actúan directamente sobre los mastocitos, llamadas en la literatura "reacciones anafilactoideas". La anafilaxia fue descrita por Paul Portier y Charles Robert Richet en 1902 en perros, los cuales desarrollaban esta reacción posterior a la inyección repetida de veneno de anémonas (medusas). Sin embargo, esta entidad no tuvo criterios diagnósticos ni pilares de manejo estructurado hasta el año 2006. En ese año en se publicó el segundo simposio de manejo de la anafilaxia, en donde se definieron criterios diagnósticos clínicos claros y el rol fundamental de la adrenalina en su manejo; la única droga que cambia el pronóstico del paciente.

Anaphylaxis is mainly a type I hypersensitivity reaction. It triggers a widespread activation of mast cells, causing a multisystemic clinical scenario that can be fatal. It is estimated to have an incidence of 0.03-0.1% and a lifetime prevalence of 0.5-2%. Most immunological reactions occur after food ingestion, medication, or insect stings, but non-immunological (non-IgE) mechanisms that act directly on mast cells, called Anaphylactoid Reactions, have been also described. Anaphylaxis was described by Paul Portier and Charles Robert Richet in 1902 in dogs, that developed this disease after repeated injections of anemones (jellyfish) venom. However, this entity didn't have established diagnostic criteria or an standarized management until 2006. In this year, the second anaphylaxis management sym-posium took place and clear clinical diagnostic criteria were defined. The fundamental role of adrenaline in its management was also established. The former is the only drug that has demonstrated to improve prognosis of the patient

Role of TrkB in the anxiolytic-like and antidepressant-like effects of vagal nerve stimulation: Comparison with desipramine.

A current hypothesis regarding the mechanism of antidepressant (AD) action suggests the involvement of brain-derived neurotrophic factor (BDNF). Consistent with this hypothesis, the receptor for BDNF (and neurotrophin 4/5 (NT-4/5)), Tropomyosin-related kinase B (TrkB), is activated in rodents by treatment with classical AD drugs. Vagal nerve stimulation (VNS), a therapy for treatment resistant depression (TRD), also activates TrkB in rodents. However, the role of this receptor in the therapeutic effects of VNS is unclear. In the current study, the involvement of TrkB in the effects of VNS was investigated in rats using its inhibitor, K252a. Anxiolytic-like and AD-like effects were analyzed using the novelty suppressed feeding test (NSFT) and forced swim test (FST), respectively. K252a blocked the anxiolytic-like effect of chronic VNS treatment and the AD-like effect of acute VNS treatment. By contrast, blocking TrkB did not prevent either the anxiolytic-like or AD-like effect of chronic treatment with desipramine (DMI), a selective noradrenergic reuptake inhibitor; it did, however, block the acute effect of DMI in the FST. To examine whether the activation of TrkB caused by either VNS or DMI is ligand-dependent, use was made of TrkB-Fc, a molecular scavenger for ligands of TrkB. Intraventricular administration of TrkB-Fc blocked the acute activation of TrkB induced by either treatment, indicating that treatment-induced activation of this receptor is ligand-dependent. The behavioral results highlight differences in the involvement of TrkB in the chronic effects of an AD drug and a stimulation therapy as well as its role in acute versus chronic effects of DMI.

Activation of a ventral hippocampus-medial prefrontal cortex pathway is both necessary and sufficient for an antidepressant response to ketamine.

A single sub-anesthetic dose of ketamine exerts rapid and sustained antidepressant effects. Here, we examined the role of the ventral hippocampus (vHipp)-medial prefrontal cortex (mPFC) pathway in ketamine's antidepressant response. Inactivation of the vHipp with lidocaine prevented the sustained, but not acute, antidepressant-like effect of ketamine as measured by the forced swim test (FST). Moreover, optogenetic as well as pharmacogenetic specific activation of the vHipp-mPFC pathway using DREADDs (designer receptors exclusively activated by designer drugs) mimicked the antidepressant-like response to ketamine; importantly, this was pathway specific, in that activation of a vHipp to nucleus accumbens circuit did not do this. Furthermore, optogenetic inactivation of the vHipp/mPFC pathway at the time of FST completely reversed ketamine's antidepressant response. In addition, we found that a transient increase in TrkB receptor phosphorylation in the vHipp contributes to ketamine's sustained antidepressant response. These data demonstrate that activity in the vHipp-mPFC pathway is both necessary and sufficient for the antidepressant-like effect of ketamine.

Thermally induced all-optical inverter and dynamic hysteresis loops in graphene oxide dispersions.

We experimentally study the temporal dynamics of amplitude-modulated laser beams propagating through a water dispersion of graphene oxide sheets in a fiber-to-fiber U-bench. Nonlinear refraction induced in the sample by thermal effects leads to both phase reversing of the transmitted signals and dynamic hysteresis in the input-output power curves. A theoretical model including beam propagation and thermal lensing dynamics reproduces the experimental findings.

[Control of postoperative pain in knee arthroplasty: single dose femoral nerve block versus continuous femoral block]. / Control del dolor postoperatorio en artroplastia de rodilla: bloqueo del nervio femoral con dosis única frente a bloqueo femoral continuo.

INTRODUCTION: To compare the efficacy of a multimodal analgesia with 2 different techniques (femoral nerve block with a single dose and continuous femoral nerve block) in the control of pain, use of opioids, and secondary effects in patients subjected to total knee replacement. MATERIAL AND METHODS: A prospective randomised study of patients subjected to knee replacement with subarachnoid anaesthesia. The postoperative analgesia consisted of tramadol, dexketoprofen and paracetamol, and one of the following techniques: Femoral nerve block with a single dose of 30mL of 0.5% ropivacaine, or that dose plus a continuous infusion via a femoral catheter of 0.375% ropivacaine 6ml/h for 48h. The demographic, anaesthetic and surgical variables were recorded, along with the pain intensity using a visual analogue scale, opioid use, and complications at 24 and 48h after surgery. RESULTS: A total of 104 patients were included. There no differences in the demographic data between the groups. The pain intensity was lower in the group that had continuous femoral block, particularly at 48h, compared to the single-dose block, and with a lower use of rescue analgesia in the continuous femoral block. The incidence in secondary effects was similar, with a lower long-term sensory block being observed in the femoral block with a single dose. CONCLUSIONS: The use of peripheral nerve block is accepted practice for analgesia after knee replacement surgery. Continuous femoral block is a valid alternative, decreasing the use of rescue opiates and pain intensity (particularly at 48h) compared to isolated femoral block.

Control del dolor postoperatorio en artroplastia de rodilla: bloqueo del nervio femoral con dosis única frente a bloqueo femoral continuo / Control of postoperative pain in knee arthroplasty: single dose femoral nerve block versus continuous femoral block

Introducción. Comparar la eficacia de un régimen analgésico multimodal con 2 técnicas diferentes (bloqueo del nervio femoral con dosis única y bloqueo continuo del nervio femoral) en el control del dolor, consumo de opioides y efectos secundarios en pacientes intervenidos de artroplastia total de rodilla. Material y métodos. Estudio prospectivo aleatorizado, de pacientes intervenidos de prótesis de rodilla con anestesia subaracnoidea. La analgesia postoperatoria consistió en tramadol, dexketoprofeno y paracetamol, y una de las 2 técnicas siguientes: bloqueo del nervio femoral con dosis única de 30ml de ropivacaína 0,5% o la anterior dosis más perfusión continua por un catéter femoral de ropivacaína 0,375%, 6ml/h durante 48h. Se registraron las variables demográficas, anestésicas y quirúrgicas, intensidad del dolor según escala visual analógica, consumo de opiáceos y complicaciones a las 24 y 48h. Resultados. Se incluyeó a 104 pacientes. No hubo diferencias demográficas entre los grupos. La intensidad del dolor fue menor en el grupo en el que se realizó bloqueo femoral continuo, especialmente a las 48h, frente al bloqueo con dosis única, con menor consumo de analgesia de rescate en el bloqueo femoral continuo. La incidencia de efectos secundarios fue similar, observándose un menor bloqueo sensitivo de larga duración en el bloqueo femoral con dosis única. Conclusiones. El uso de los bloqueos nerviosos periféricos está aceptado para la analgesia postoperatoria de las artroplastias de las rodillas. El bloqueo femoral continuo es una alternativa válida disminuyendo el consumo de opiáceos de rescate y la intensidad del dolor (especialmente a las 48h) respecto al bloqueo femoral aislado(AU)

Introduction. To compare the efficacy of a multimodal analgesia with 2 different techniques (femoral nerve block with a single dose and continuous femoral nerve block) in the control of pain, use of opioids, and secondary effects in patients subjected to total knee replacement. Material and methods. A prospective randomised study of patients subjected to knee replacement with subarachnoid anaesthesia. The postoperative analgesia consisted of tramadol, dexketoprofen and paracetamol, and one of the following techniques: Femoral nerve block with a single dose of 30mL of 0.5% ropivacaine, or that dose plus a continuous infusion via a femoral catheter of 0.375% ropivacaine 6ml/h for 48h. The demographic, anaesthetic and surgical variables were recorded, along with the pain intensity using a visual analogue scale, opioid use, and complications at 24 and 48h after surgery. Results. A total of 104 patients were included. There no differences in the demographic data between the groups. The pain intensity was lower in the group that had continuous femoral block, particularly at 48h, compared to the single-dose block, and with a lower use of rescue analgesia in the continuous femoral block. The incidence in secondary effects was similar, with a lower long-term sensory block being observed in the femoral block with a single dose. Conclusions. The use of peripheral nerve block is accepted practice for analgesia after knee replacement surgery. Continuous femoral block is a valid alternative, decreasing the use of rescue opiates and pain intensity (particularly at 48h) compared to isolated femoral block(AU)

Cathepsin B from the white shrimp Litopenaeus vannamei: cDNA sequence analysis, tissues-specific expression and biological activity.

Cathepsin B is a cystein proteinase scarcely studied in crustaceans. Its function has not been clearly described in shrimp species belonging to the sub-order Dendrobranchiata, which includes the white shrimp Litopenaeus vannamei and other species from the Penaeidae family. Studies on vertebrates suggest that these lysosomal enzymes intracellularly hydrolize protein, as other cystein proteinases. However, the expression of the gene encoding the shrimp cathepsin B in the midgut gland was affected by starvation in a similar way as other digestive proteinases which extracellularly hydrolyze food protein. In this study the white shrimp L. vannamei cathepsin B (LvCathB) cDNA was sequenced, and characterized. Its gene expression was evaluated in various shrimp tissues, and changes in the mRNA amounts were compared with those observed on other digestive proteinases from the midgut gland during starvation. By using qRT-PCR it was found that LvCathB is expressed in most shrimp tissues except in pleopods and eye stalk. Changes on LvCathB mRNA during starvation suggest that the enzyme participates during intracellular protein hydrolysis but also, after food ingestion, it participates in hydrolyzing food proteins extracellularly as confirmed by the high activity levels we found in the gastric juice and midgut gland of the white shrimp.

Region-specific changes in transient receptor potential vanilloid channel expression in the vasopressin magnocellular system in hepatic cirrhosis-induced hyponatraemia.

The present study aimed to measure the expression of transient receptor potential (TRP) channels in the magnocellular neurones of the paraventricular (PVN) and supraoptic nucleus (SON) in an animal model of hepatic cirrhosis associated with inappropriate vasopressin (AVP) release. In these studies, we used chronic bile duct ligation (BDL) in the rat, which is a commonly used model of hepatic cirrhosis, associated with elevated plasma AVP. The present study tested the hypothesis that changes in TRP vanilloid (TRPV) channel expression may be related to inappropriate AVP release in BDL rats. To test our hypothesis, we utilised laser capture microdissection of AVP neurones in the PVN and SON and western blot analysis from brain punches. Laser capture microdissection and quantitative reverse transcriptase-polymerase chain reaction demonstrated elevated TRPV2 mRNA in the PVN and SON of BDL compared to sham-ligated controls. AVP transcription was also increased as determined using intron specific primers to measure heteronuclear RNA. Immunohistochemistry demonstrated increased AVP and TRPV2 positive cells in both the PVN and SON after BDL. Also, there was an increased co-expression of TRPV2 and AVP cells after BDL. However, there was no change in the colocalisation counts of TRPV2 and oxytocin in both the magnocellular regions evaluated. In the SON but not the PVN, the transcription levels of TRPV4 were also significantly increased in BDL rats. Western blot analysis of punches containing the PVN and SON revealed that TRPV2 protein content was significantly increased in these brain regions in BDL rats compared to sham rats. Our data suggest that regionally specific changes in TRPV expression in the magnocellular neurosecretory cell AVP neurones could alter their osmosensing ability.

Brain-derived neurotrophic factor-tyrosine kinase B pathway mediates NMDA receptor NR2B subunit phosphorylation in the supraoptic nuclei following progressive dehydration.

We studied the effects of water deprivation (WD) on the phosphorylation of tyrosine kinase B (TrkB) and NMDA receptor subunits in the supraoptic nucleus (SON) of the rat. Laser capture microdissection and quantitative reverse transcriptase polymerase chain reaction was used to demonstrate brain-derived neurotrophic factor (BDNF) and TrkB gene expression in vasopressin SON neurones. Immunohistochemistry confirmed BDNF staining in vasopressin neurones, whereas staining for phosphorylated TrkB was increased following WD. Western blot analysis of brain punches containing the SON revealed that tyrosine phosphorylation of TrkB (pTrkBY(515)), serine phosphorylation of NR1 (pNR1S(866) or pNR1) and tyrosine phosphorylation of NR2B subunits (pNR2BY(1472) or pNR2B) were significantly increased in WD animals compared to controls. Access to water for 2 h reduced pTrkBY(515) content to control levels without affecting pNR1 or pNR2B. Four hours of rehydration was needed to reduce pNR1 and pNR2B to control levels. To test whether increased phosphorylation of TrkB in the present study is mediated by BDNF, a group of animals were instrumented with right SON cannula coupled to mini-osmotic pumps filled with vehicle or TrkB-Fc fusion protein, which prevents BDNF binding to TrkB. In the left SON contralateral to the cannula, TrkB phosphorylation was significantly enhanced following WD. Separate analysis of the right SON, which received TrkB-Fc, showed that the TrkB receptor phosphorylation following WD was significantly attenuated. Although increased pNR1S(866) following WD was not affected by local infusion of TrkB-Fc, pNR2BY(1472) was significantly reduced. Co-immunoprecipitation revealed an increased physical interaction between Fyn kinase and NR2B and TrkB in the SON following WD. Thus, activation of TrkB in the SON following WD may affect cellular excitability through the phosphorylation of NR2B subunits.

Functional properties of protein from frozen mantle and fin of jumbo squid Dosidicus gigas in function of pH and ionic strength.

Functional properties of protein from mantle and fin of the jumbo squid Dosidicus gigas were explained based on microscopic muscle fiber and protein fractions profiles as observed in SDS-PAGE. Fin has higher content of connective tissue and complex fiber arrangement, and we observed higher hardness of fin gels as expected. Myosin heavy chain (MHC) was found in sarcoplasmic, myofibril and soluble-in-alkali fractions of mantle and only in sarcoplasmic and soluble-in-alkali fractions of fin. An additive effect of salt concentration and pH affected the solubility and foaming properties. Fin and mantle proteins yielded similar results in solubility tests, but significant differences occurred for specific pH and concentrations of salt. Foaming capacity was proportional to solubility; foam stability was also affected by pH and salt concentration. Hardness and fracture strength of fin gels were significantly higher than mantle gels; gels from proteins of both tissues reached the highest level in the folding test. Structural and molecular properties, such as MHC and paramyosin solubility, arrangement of muscle fibers and the content of connective tissue were useful to explain the differences observed in these protein properties. High-strength gels can be formed from squid mantle or fin muscle. Fin displayed similar or better properties than mantle in all tests.

Modulation-frequency-controlled change from sub- to superluminal regime in highly doped erbium fibers.

We report a change from sub- to superluminal propagation upon increasing the modulation frequency of an amplitude-modulated 1,550 nm signal when propagating through highly doped erbium fibers pumped at 980 nm. We show that the interplay between the pump absorption and the pump-power broadening of the spectral hole induced by coherent population oscillations may drastically affect the fractional advancement or delay of the signal for the considered fibers.

ACE gene titration in mice uncovers a new mechanism for ACE on the control of body weight.

Mice harboring 1, 2, or 3 copies of the angiotensin-converting enzyme (ACE) gene were used to evaluate the quantitative role of the ACE locus on obesity. Three-copy mice fed with a high-fat diet had lower body weight and peri-epididymal adipose tissue than did 1- and 2-copy mice (P < 0.05). On regular diet, 3-copy mice had to eat more to maintain the same body weight; on a high-fat diet, they ate the same but weighed less than 1- and 2-copy mice (P < 0.05), indicating a higher metabolic rate in 3-copy mice that was not affected by ANG II AT(1) blocker treatment. A catalytically inactive form of thimet oligopeptidase (EC 3.4.24.15; EP24.15) was used to isolate ACE substrates from adipose tissue. Liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) identified 162 peptide peaks; 16 peptides were present in both groups (1- and 3-copy mice fed with a high-fat diet), whereas 58 of the 72 unique peptides were found only in the 3-copy mice. Peptide size distribution was shifted to lower molecular weight in 3-copy mice. Two of the identified peptides, LVVYPWTQRY and VVYPWTQRY, which are ACE substrates, inhibited in vitro protein kinase C phosphorylation in a concentration-dependent manner. In addition, neurolysin (EC 3.4.24.16; EP24.16) activity was lower in fat tissue from 3- vs. 1-copy mice (P < 0.05). Taken together, these results provide evidence that ACE is associated with body weight and peri-epididymal fat accumulation. This response may involve the generation of oligopeptides that inhibit the activity of EP24.16 and other oligopeptidases within the adipose tissue.

From nearly tilted waves to cavity phase solitons in broad area lasers with squeezed vacuum.

Phase domains and phase solitons in two-level amplifying media damped by a squeezed vacuum are predicted for the first time. Two different types of pattern formation are found depending on the relative value of the cavity detuning to the squeezed parameter: the usual one in lasers via a supercritical Hopf bifurcation and a new one via pitchfork bifurcation.

A comparative randomized study of three different IUDs in nulliparous Mexican women.

With the aim to evaluate the clinical performance of intrauterine devices (IUDs) especially designed for nulliparous women (TCu 380 Nul and ML Cu 375 sl), a prospective randomized, single-blind study comparing them with standard TCu 380 A, was carried out. We included 1170 healthy nulliparous women randomly allocated to receive any of the three types of IUDs and conducted follow-up for 1 year of use. Continuation and termination rates were evaluated by gross cumulative life table analysis and compared by the log-rank test. Continuation rates (95% confidence interval) at the end of the study for TCu 380 A, TCu 380 Nul and ML Cu 375 sl were 29.5% (+/-12.9), 85.9% (+/-5.3) and 85.4% (+/-5.8), respectively (p < 0.001). There were six pregnancies during the first 3 months of use, for a failure rate of 1% (+/-0.6) in the TCu 380 A group, 0.5% (+/-0.3) in TCu 380 Nul, and no pregnancy in ML Cu 375 sl (p < 0.05). Especially designed IUDs for nulliparous women had a better clinical profile compared with the standard IUD. This may improve the use of IUD in this population.

Digestive enzymes in juvenile green abalone, Haliotis fulgens, fed natural food.

Enzymes responsible for the digestion of food protein by juvenile green abalone (Haliotis fulgens) were studied when fed algae or a sea grass (Phyllospadix torreyi) naturally occurring in the habitat. The effect of food on the composition and activity of the enzymes was also evaluated. Acid, serine proteinases and aminopeptidases, as confirmed by pH profile of activity, specific inhibition and synthetic substrate hydrolysis were found in the digestive organs of juvenile green abalone. Algae and sea grass differentially affected the digestive system in abalone.

Parálisis diafragmática y artromialgia por enfermedad de Lyme / Diaphragmatic paralysis and arthromyalgias due to Lyme disease

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Digestive proteinases of Artemesia longinaris (Decapoda, Penaeidae) and relationship with molting.

Digestive proteinase activities of Artemesia longinaris were assayed at different stages of the molting cycle. Total proteolytic activity in the hepatopancreas was highest during postmolt. Trypsin and chymotrypsin activities were highest during intermolt. Specific inhibitors and zymograms of A. longinaris hepatopancreas extracts showed four trypsins (14.79, 15.49, 16.60, 17.38 kDa, respectively) and three chymotrypsins (21.38, 22.91, 27.54 kDa, respectively). Our results suggest that proteolytic activity in the hepatopancreas of A. longinaris is influenced by the molting cycle. Types and activity of prawn digestive enzymes constitute background information to further study the digestive abilities of these organisms and will lead to understanding their nutritional needs and feeding ecology.

Digestive proteinases of red shrimp Pleoticus muelleri (Decapoda, Penaeoidea): partial characterization and relationship with molting.

The present study describes the activity and some characteristics of proteinases in the hepatopancreas of red shrimp Pleoticus muelleri during the different stages of the molting cycle. Proteolytic activity was highest between pH 7.5 and 8. The hepatopancreatic protein content in the premolt stage was higher than in the other stages of the molting cycle (P<0.05). No significant differences were found in total proteolytic activity in the hepatopancreas when comparing molting stages. The proteolytic activity of the P. muelleri hepatopancreas enzyme preparations is the main responsibility of serine proteinases. TLCK, a trypsin inhibitor, reduced azocasein hydrolysis between 26% (intermolt) and 37% (premolt). TPCK, a chymotrypsin inhibitor, did not decrease hydrolytic activity, except for in postmolt. Low trypsin and chymotrypsin activities were found during intermolt, and increased in postmolt. The electrophoretogram of the enzyme extracts shows 12 bands of activity during intermolt (from 16.6 to 53.1 kDa). Some fractions were not detected in the postmolt and premolt stages. Three low molecular weight trypsin forms (17.4, 19.1 and 20 kDa) were found in all molting stages. One band of chymotrypsin (21.9 kDa) was observed in all molting stages. High molecular mass active bands (66-205 kDa) could not be characterized with inhibitors. Comparison of the protease-specific activity of the hepatopancreas of some species indicated a relationship between digestive enzyme activity and feeding habits of the shrimp. Omnivorous shrimp, such as Penaeus vannamei (syn: Litopenaeus vannamei) and Penaeus monodon, showed higher protease activity than the carnivorous shrimp, Penaeus californiensis (syn: Farfantepenaeus californiensis) and P. muelleri. In fact, the enzymatic activity in the hepatopancreas of P. muelleri showed variations in relation to feeding habit and molting cycle.