The balance between antibiotic resistance and fitness/virulence in Pseudomonas aeruginosa: an update on basic knowledge and fundamental research.

The interplay between antibiotic resistance and bacterial fitness/virulence has attracted the interest of researchers for decades because of its therapeutic implications, since it is classically assumed that resistance usually entails certain biological costs. Reviews on this topic revise the published data from a general point of view, including studies based on clinical strains or in vitro-evolved mutants in which the resistance phenotype is seen as a final outcome, i.e., a combination of mechanisms. However, a review analyzing the resistance/fitness balance from the basic research perspective, compiling studies in which the different resistance pathways and respective biological costs are individually approached, was missing. Here we cover this gap, specifically focusing on Pseudomonas aeruginosa, a pathogen that stands out because of its extraordinary capacity for resistance development and for which a considerable number of recent and particular data on the interplay with fitness/virulence have been released. The revised information, split into horizontally-acquired vs. mutation-driven resistance, suggests a great complexity and even controversy in the resistance-fitness/virulence balance in the acute infection context, with results ranging from high costs linked to certain pathways to others that are seemingly cost-free or even cases of resistance mechanisms contributing to increased pathogenic capacities. The elusive mechanistic basis for some enigmatic data, knowledge gaps, and possibilities for therapeutic exploitation are discussed. The information gathered suggests that resistance-fitness/virulence interplay may be a source of potential antipseudomonal targets and thus, this review poses the elementary first step for the future development of these strategies harnessing certain resistance-associated biological burdens.

Pollen analysis reveals the effects of uncovered interactions, pollen-carrying structures, and pollinator sex on the structure of wild bee-plant networks.

Pollination networks are increasingly used to model the complexity of interactions between pollinators and flowering plants in communities. Different methods exist to sample these interactions, with direct observations of plant-pollinator contacts in the field being by far the most common. Although the identification of pollen carried by pollinators allows uncovering interactions and increasing sample sizes, the methods used to build pollen-transport networks are variable and their effect on network structure remains unclear. To understand how interaction sampling influences the structure of networks, we analyzed the pollen found on wild bees from eight communities across Mallorca Island and investigated the differences in pollen loads between bee body parts (scopa vs. body) and sexes. We then assessed how these differences, as well as the uncovered interactions not detected in the field, influenced the structure of wild bee-plant networks. We identified a higher quantity and diversity of pollen in the scopa than in the rest of the female body, but these differences did not lead to differences in structure between plant-pollination (excluding scopa pollen) and bee-feeding interaction (including scopa pollen) networks. However, networks built with pollen data were richer in plant species and interactions and showed lower modularity and specialization (H2 '), and higher nestedness than visitation networks based on field observations. Female interactions with plants were stronger compared to those of males, although not richer. Accordingly, females were more generalist (low d') and tended to be more central in interaction networks, indicating their more key role structuring pollination networks in comparison to males. Our study highlights the importance of palynological data to increase the resolution of networks, as well as to understand important ecological questions such as the differences between plant-pollination and bee-feeding interaction networks, and the role of sexes in pollination.

Extra-criteria antiphospholipid antibodies in patients with small vessel brain lesions and clinical manifestations associated with antiphospholipid syndrome.

OBJECTIVES: Neurological manifestations compatible with small vessel brain lesions (SVBL), such as migraine, cognitive impairment, seizures, and transverse myelitis, may be related to antiphospholipid syndrome (APS) and patients could need APS therapies even though they do not fit into thrombosis or obstetric morbidity. Furthermore, extra-criteria antiphospholipid antibodies (aPL) provide an increase in sensitivity in patients with clinical manifestations related to APS but negative for IgG/IgM anticardiolipin (aCL), anti-ß2 glycoprotein I (aß2GPI), and lupus anticoagulant, which are the antibodies included in the classification criteria for APS. METHODS: We determined extra-criteria aPL in 65 SVBL patients with neurological traits and Magnetic Resonance Imaging suggestive of APS but negative for APS classification criteria, 47 of whom were prospectively followed and tested over three years. A group of 95 patients with autoimmune diseases (AD) but without clinical traits of APS was also studied. RESULTS: A persistent presence of extra-criteria aPL was detected in 27.7% of patients: 12.77% IgM anti- prothrombin (PT), 6.38% IgG anti-PT, 6.38% IgM anti-phosphatidylethanolamine (PE), 4.26% IgA aß2GPI, 2.13% IgG anti-phosphatidylserine/prothrombin (PS/PT) and 2.13% IgM anti-PS/PT. There was a tendency towards a higher prevalence of these aPL in SVBL patients than in AD - especially for IgA aß2GPI - and a lack of IgG aPS/PT positivity in the AD group. We found no SVBL patient positive for IgA aCL, IgG anti-PE, annexin V, or aß2GPI domain I. CONCLUSIONS: Extra-criteria aPL can improve sensitivity for APS diagnosis in patients with SVBL, especially IgA aß2GPI and IgG anti-PS/PT antibodies.

Effects of habitat disturbance on the reproductive ecology of Arum pictum ssp. sagittifolium: from pollination to seedling recruitment.

BACKGROUND AND AIMS: The loss of natural habitats may strongly affect the fitness of plants that depend on animals for reproduction. However, very little is known regarding the differential effects of habitat disturbance on the distinct phases of the reproductive cycle of plants, especially in non-rewarding species. METHODS: We assessed the effects of habitat disturbance on the entire reproductive cycle of Arum pictum ssp. sagittifolium, a species with deceptive pollination that is endemic to the western Mediterranean Basin. For this, we performed hand-pollination and bagging experiments, evaluated the role of pollinators and dispersers on reproduction, and estimated seedling recruitment in three natural and three disturbed populations (according to their surrounding natural habitat) in Mallorca Island. KEY RESULTS: Pollinators were sphaerocerid flies (mainly Coproica, with ~50 % of visits) and staphylinid beetles, and were required for sexual reproduction. Habitat disturbance differently affected the reproductive phases of A. pictum ssp. sagittifolium. Habitat disturbance had a positive effect on Shannon pollinator diversity (but not on pollinator richness), and total pollinator and Coproica abundance were three times higher in disturbed habitats, where overall seed production was also ~30 % higher in natural habitats. Seed production increased with Coproica abundance, but only in natural habitats. Seed dispersers of A. pictum ssp. sagittifolium were birds, mainly Sylvia atricapilla. Although habitat disturbance did not influence disperser diversity or abundance, the majority of seedlings appeared under adult plants and in natural habitats. CONCLUSIONS: Overall recruitment was higher in natural habitats, but this effect could have been masked by only assessing pollinator and disperser numbers, as processes related to the quality of these interactions might be influencing fitness. Our study highlights the need to study different reproductive phases and their multiple components and processes to properly understand the effects of habitat disturbance on the regeneration of plant populations.

Pollinator richness, pollination networks, and diet adjustment along local and landscape gradients of resource diversity.

Loss of habitats and native species, introduction of invasive species, and changing climate regimes lead to the homogenization of landscapes and communities, affecting the availability of habitats and resources for economically important guilds, such as pollinators. Understanding how pollinators and their interactions vary along resource diversity gradients at different scales may help to determine their adaptability to the current diversity loss related to global change. We used data on 20 plant-pollinator communities along gradients of flower richness (local diversity) and landscape heterogeneity (landscape diversity) to understand how the diversity of resources at local and landscape scales affected (1) wild pollinator abundance and richness (accounting also for honey bee abundance), (2) the structure of plant-pollinator networks, (3) the proportion of actively selected interactions (those not occurring by neutral processes), and (4) pollinator diet breadth and species' specialization in networks. Wild pollinator abundance was higher overall in flower-rich and heterogeneous habitats, while wild pollinator richness increased with flower richness (more strongly for beetles and wild bees) and decreased with honeybee abundance. Network specialization (H2 '), modularity, and functional complementarity were all positively related to floral richness and landscape heterogeneity, indicating niche segregation as the diversity of resources increases at both scales. Flower richness also increased the proportion of actively selected interactions (especially for wild bees and flies), whereas landscape heterogeneity had a weak negative effect on this variable. Overall, network-level metrics responded to larger landscape scales than pollinator-level metrics did. Higher floral richness resulted in a wider taxonomic and functional diet for all the study guilds, while functional diet increased mainly for beetles. Despite this, specialization in networks (d') increased with flower richness for all the study guilds, because pollinator species fed on a narrower subset of plants as communities became richer in species. Our study indicates that pollinators are able to adapt their diet to resource changes at local and landscape scales. However, resource homogenization might lead to poor and generalist pollinator communities, where functionally specialized interactions are lost. This study highlights the importance of including different scales to understand the effects of global change on pollination service through changes in resource diversity.

Case Reports Showing a Long-Term Effect of Subanesthetic Ketamine Infusion in Reducing l-DOPA-Induced Dyskinesias.

Ketamine is an FDA-approved drug with a known safety profile. Low-dose subanesthetic intravenous ketamine infusion treatment has led to long-term reduction of treatment-resistant depression and of chronic pain states. We report on low-dose subanesthetic intravenous ketamine infusion treatment in Parkinson's disease (PD) patients by 5 case studies and show a long-lasting therapeutic benefit to reduce l-DOPA-induced dyskinesia (LID), improve on time, and reduce depression. Based on the literature we hypothesize that low-dose ketamine may act as a 'chemical deep brain stimulation', by desynchronizing hypersynchronous oscillatory brain activity, including in the basal ganglia and the motor cortex. The presented PD case reports indicate tolerability, safety and long-term beneficial effects of low-dose ketamine infusion that should be further investigated in a properly controlled prospective clinical trial for treatment of LID, as well as the prevalent nonmotor features pain and depression in PD patients.

Long-term effect of sub-anesthetic ketamine in reducing L-DOPA-induced dyskinesias in a preclinical model.

Low-dose sub-anesthetic ketamine infusion treatment has led to a long-term reduction of treatment-resistant depression and posttraumatic stress disorder (PTSD) symptom severity, as well as reduction of chronic pain states, including migraine headaches. Ketamine also is known to change oscillatory electric brain activity. One commonality between migraine headaches, depression, PTSD, Parkinson's disease (PD) and l-DOPA-induced dyskinesias (LID) is hypersynchrony of electric activity in the brain, including the basal ganglia. Therefore, we investigated the use of low-dose sub-anesthetic ketamine in the treatment of LID. In a preclinical rodent model of LID, ketamine (5-20mg/kg) led to long-term dose-dependent reduction of abnormal involuntary movements, only when low-dose ketamine was given for 10h continuously (5× i.p. injections two hours apart) and not after a single acute low-dose ketamine i.p. injection. Pharmacokinetic analysis of plasma levels showed ketamine and its major metabolites were not detectable any more at time points when a lasting anti-dyskinetic effect was seen, indicating a plastic change in the brain. This novel use of low-dose sub-anesthetic ketamine infusion could lead to fast clinical translation, and since depression and comorbid pain states are critical problems for many PD patients could open up the road to a new dual therapy for patients with LID.

Síndrome HELLP: morbilidad-mortalidad materna y perinatal / HELLP syndrome: maternal morbidity and mortality perinatal

Objetivo: Evaluar la morbimortalidad materno fetal y neonatal en pacientes con síndrome HELLP. Métodos: Estudio retrospectivo, descriptivo y longitudinal que fue hecho en 128 pacientes con síndrome HELLP en el período comprendido entre enero 2004 y abril 2009 en el Servicio de Medicina Materno Fetal de la Maternidad “Concepción Palacios”. Resultados: De las 128 pacientes estudiadas, el síndrome HELLP se presentó antes del parto en 85 casos (66,4%) y después del parto en 43 casos (33,6%), el 43,8% de las pacientes fueron primigestas y el 73,4% presentaron el síndrome antes de las 37 semanas. No se presentaron casos de muerte materna. El síndrome se asoció a una alta tasa de morbilidad materna (62,5%) siendo la principal complicación la insuficiencia renal aguda (46%). No hubo ningún caso de hematoma subcapsular hepático. El 100% de las pacientes presentaron algún grado de hipertensión arterial. Hubo una alta tasa de mortalidad perinatal (18%) asociada principalmente a prematuridad. El peso promedio al nacer fue de 1 654 ± 728 g. Conclusión: El síndrome HELLP se asocia a una alta tasa de morbilidad materna extrema y alta tasa de morbimortalidad perinatal, esta última asociada principalmente a complicaciones de prematuridad.

Objective: To evaluate the maternal fetal and neonatal morbidity and mortality in patients with HELLP syndrome. Methods: Retrospective, descriptive and longitudinal study which was developed in 128 patients with HELLP syndrome in the period between January 2004 and April 2009 in the Maternal Fetal Medicine service the Maternity Concepción Palacios. Results: Of the 128 patients studied, the HELLP syndrome was presented before delivery in 85 % cases (66.4 %) and postpartum in 43 cases (33.6 %), 43.8 % of the patients were primiparous and 73.4 % had the syndrome before 37 weeks. No cases of maternal death. Syndrome is associated to a high rate of maternal morbidity (62.5 %) being the main complication of acute renal failure (46 %). There were no cases of hepatic subcapsular hematoma. 100 % of the patients had some degree of arterial hypertension. There was a high perinatal mortality rate (18 %) mainly associated with prematurity. The average birth weight was 1 654 ± 728g. Conclusion: HELLP syndrome is associated with a high rate of near miss maternal morbidity and high rates in perinatal morbidity and mortality, the latter mainly associated with complications of prematurity.

In vitro differentiation of murine hematopoietic progenitor cells toward the myeloid lineage occurs in response to Staphylococcus aureus and yeast species.

We have studied the effect of inactivated microbial stimuli (Candida albicans, Candida glabrata, Saccharomyces boulardii, and Staphylococcus aureus) on the in vitro differentiation of lineage negative (Lin(-)) hematopoietic progenitor mouse cells. Purified Lin(-) progenitors were co-cultured for 7 days with the stimuli, and cell differentiation was determined by flow cytometry analysis. All the stimuli assayed caused differentiation toward the myeloid lineage. S. boulardii and particularly C. glabrata were the stimuli that induced in a minor extent differentiation of Lin(-) cells, as the major population of differentiated cells corresponded to monocytes, whereas C. albicans and S. aureus induced differentiation beyond monocytes: to monocyte-derived dendritic cells and macrophages, respectively. Interestingly, signaling through TLR2 by its pure ligand Pam3CSK4 directed differentiation of Lin(-) cells almost exclusively to macrophages. These data support the notion that hematopoiesis can be modulated in response to microbial stimuli in a pathogen-dependent manner, being determined by the pathogen-associated molecular patterns and the pattern-recognition receptors involved, in order to generate the populations of mature cells required to deal with the pathogen.

The neurodegenerative effects of selenium are inhibited by FOXO and PINK1/PTEN regulation of insulin/insulin-like growth factor signaling in Caenorhabditis elegans.

Exposures to high levels of environmental selenium have been associated with motor neuron disease in both animals and humans and high levels of selenite have been identified in the cerebrospinal fluid of patients with amyotrophic lateral sclerosis (ALS). We have shown previously that exposures to high levels of sodium selenite in the environment of Caenorhabditis elegans adult animals can induce neurodegeneration and cell loss resulting in motor deficits and death and that this is at least partially caused by a reduction in cholinergic signaling across the neuromuscular junction. Here we provide evidence that reduction in insulin/insulin-like (IIS) signaling alters response to high dose levels of environmental selenium which in turn can regulate the IIS pathway. Most specifically we show that nuclear localization and thus activation of the DAF-16/forkhead box transcription factor occurs in response to selenium exposure although this was not observed in motor neurons of the ventral cord. Yet, tissue specific expression and generalized overexpression of DAF-16 can partially rescue the neurodegenerative and behavioral deficits observed with high dose selenium exposures in not only the cholinergic, but also the GABAergic motor neurons. In addition, two modifiers of IIS signaling, PTEN (phosphatase and tensin homolog, deleted on chromosome 10) and PINK1 (PTEN-induced putative kinase 1) are required for the cellular antioxidant reduced glutathione to mitigate the selenium-induced movement deficits. Studies have suggested that environmental exposures can lead to ALS or other neurological diseases and this model of selenium-induced neurodegeneration developed in a genetically tractable organism provides a tool for examining the combined roles of genetics and environment in the neuro-pathologic disease process.

Selenium induces cholinergic motor neuron degeneration in Caenorhabditis elegans.

Selenium is an essential micronutrient required for cellular antioxidant systems, yet at higher doses it induces oxidative stress. Additionally, in vertebrates environmental exposures to toxic levels of selenium can cause paralysis and death. Here we show that selenium-induced oxidative stress leads to decreased cholinergic signaling and degeneration of cholinergic neurons required for movement and egg-laying in Caenorhabditis elegans. Exposure to high levels of selenium leads to proteolysis of a soluble muscle protein through mechanisms suppressible by two pharmacological agents, levamisole and aldicarb which enhance cholinergic signaling in muscle. In addition, animals with reduction-of-function mutations in genes encoding post-synaptic levamisole-sensitive acetylcholine receptor subunits or the vesicular acetylcholine transporter developed impaired forward movement faster during selenium-exposure than normal animals, again confirming that selenium reduces cholinergic signaling. Finally, the antioxidant reduced glutathione, inhibits selenium-induced reductions in egg-laying through a cellular protective mechanism dependent on the C. elegans glutaredoxin, GLRX-21. These studies provide evidence that the environmental toxicant selenium induces neurodegeneration of cholinergic neurons through depletion of glutathione, a mechanism linked to the neuropathology of Alzheimer's disease, amyotrophic lateral sclerosis, and Parkinson's disease.

Enhancement of the inhibitory effect of an IL-15 antagonist peptide by alanine scanning.

IL-15 is a proinflammatory cytokine that acts early in the inflammatory response and has been associated with several autoimmune diseases including rheumatoid arthritis, where it had been proposed as a therapeutic target. We recently reported an IL-15 antagonist peptide corresponding to sequence 36-45 of IL-15 (KVTAMKCFLL) named P8, which specifically binds to IL-15Rα and inhibits IL-15 biological activity with a half maximal inhibitory concentration (IC50) of 130 µ m in CTLL-2 proliferation assay. In order to improve binding of peptide P8 to the receptor IL-15Rα, we used an Ala scan strategy to study contribution of each individual amino acid to the peptide's antagonist effect. Here, we found that Phe and Cys are important for peptide binding to IL-15Rα. We also investigated other single site mutations and replaced the second Lys in the sequence by the polar non-charged amino acid threonine. The resulting peptide [K6T]P8 exhibited a higher activity than P8 with an IC50 of 24 µm. We also found that this peptide was more active than peptide P8 in the inhibition of TNFα secretion by synovial cells from rheumatoid arthritis patients. The peptide [K6T]P8 described in this work is a new type of IL-15 antagonist and constitutes a potential therapeutic agent for rheumatoid arthritis.

The glutaredoxin GLRX-21 functions to prevent selenium-induced oxidative stress in Caenorhabditis elegans.

Selenium is an essential micronutrient that functions as an antioxidant. Yet, at higher concentrations, selenium is pro-oxidant and toxic. In extreme cases, exposures to excess selenium can lead to death or selenosis, a syndrome characterized by teeth, hair and nail loss, and nervous system alterations. Recent interest in selenium as an anti- tumorigenic agent has reemphasized the need to understand the mechanisms underlying the cellular consequences of increased selenium exposure. We show here, that in the nematode, Caenorhabditis elegans, selenium has a concentration range in which it functions as an antioxidant, but beyond this range it exhibits a dose- and time-dependent lethality. Oxidation-induced fluorescence emitted by the dye, carboxy-H(2)DCFDA, indicative of reactive oxygen species formation was significantly higher in animals after a brief exposure to 5mM sodium selenite. Longer-term exposures lead to a progressive selenium-induced motility impairment that could be partially prevented by coincident exposure to the cellular antioxidant-reduced glutathione. The C elegans glrx-21 gene belongs to the family of glutaredoxins (glutathione-dependent oxidoreductases) and the glrx-21(tm2921) allele is a null mutation that renders animals hypersensitive for the selenium-induced motility impairment, but not lethality. In addition, the lethality of animals with the tm2921 mutation exposed to selenium was unaffected by the addition of reduced glutathione, suggesting that GLRX-21 is required for glutathione to moderate this selenium-induced lethality. Our findings provide the first description of selenium-induced toxicity in C elegans and support its use as a model for elucidating the mechanisms of selenium toxicity.

Identification of a CREB-dependent serotonergic pathway and neuronal circuit regulating foraging behavior in Caenorhabditis elegans: a useful model for mental disorders and their treatments?

The cAMP-response element binding protein (CREB)-mediated cell signaling pathway is conserved through evolution and participates in a broad range of complex behaviors of divergent species including man. This study describes the integration of genetic, pharmacologic, and anatomic methods to elucidate a serotonergic signaling pathway by which the CREB homolog CRH-1 controls foraging rate (FR) in the model organism Caenorhabditis elegans, along with the complete neuronal circuit through which this pathway operates. In the anterior afferent arm of the circuit, CRH-1 controls FR by regulating the expression of tph-1, the sole structural gene for tryptophan hydroxylase, in serotonergic sensory (ADF) neurons whose post-synaptic effects are mediated through 5HT(2)-like SER-1 receptors. The posterior afferent limb of the circuit includes an interneuron (RIH) that does not express tph-1 and whose serotonergic phenotype is dependent on the contribution of this neurotransmitter from another source, probably the ADF neurons. The postsynaptic effects of the RIH interneuron are mediated through 5HT(1)-like SER-4 receptors. This model has potential utility for the study of clinical disorders and experimental therapeutics. Furthermore, the discovery of serotonergic neurons that depend on other sources for their neurotransmitter phenotype could provide a mechanism for rapidly altering the number and distribution of serotonergic pathways in developing and adult nervous systems, providing a dimension of functional complexity that has been previously unrecognized.

Factor reumatoide: asociación con la erosión radiológica y actividad de la artritis reumatoide / Rheumatoid factor: association with the radiological erosion and with the rheumatoid arthritis activity

Objetivo: Definir la relación del factor reumatoide (FR) con la erosión articular radiológica, la actividad de la enfermedad y la discapacidad funcional de la artritis reumatoide (AR). Métodos: Se realizó un estudio transversal con 209 pacientes con AR establecida, de estos, 74 con AR de corta evolución (= 2 años). Se evaluaron los indicadores siguientes: FR por aglutinación del látex (FR-A), FR por inmunoturbidimetría automatizada (FR-T), velocidad de eritrosedimentación (VSG), proteína C reactiva (PCR), índice de actividad de la enfermedad (Disease Activity Score 28, DAS28), índice de discapacidad funcional (Health Assessment Questionnaire score, HAQ) y la presencia de erosiones radiológicas. Resultados: El 77 por ciento de los pacientes positivos de FR-A y el 73 por ciento de los positivos para el FR-T presentaron erosiones radiológicas, opuestamente al 38 por ciento de los negativos para el FR-A (p<0,001) y al 14 por ciento de los negativos para el FR-T (p<0,001). Las cifras medias del FR-A de los pacientes según los 4 grados de afectación articular (máximo: > 6 articulaciones erosionadas; mínimo: 0 erosión, < 6 articulaciones inflamadas) fueron de: 484; 162; 57 y 17 UI/mL (p<0,001); y las del FR-T de: 277; 185; 22 y 33 UI/mL (p<0,01). El valor predictivo positivo (VPP) para la erosión del FR-A >512 UI/mL fue de 92 por ciento y el del FR-T >97 UI/mL fue de 96 por ciento. Los valores medios del DAS28 en los pacientes positivos de FR-A y FR-T fueron de 5,04 y 4,94, respectivamente, mientras que, en los negativos fueron de 4,26 y 3,97 (p<0,001 para ambos); y los del HAQ de 1,31 y 1,29 en los positivos de FR-A y FR-T, respectivamente, mientras que en los negativos de 0,99 y 0,89 (p<0,01 para ambos). Se encontró correlación entre las cifras del FR por ambos métodos y las de VSG, PCR, DAS28 y HAQ (p<0,05 o p<0,01). Conclusiones: Niveles altos del FR se corresponden con un grado mayor de inflamación y destrucción articular en la AR.

Objective: to define the relation of the rheumatoid factor with the radiological articular erosion, the activity of the disease and the functional disability of rheumatoid artritis (RA). Methods: A cross-sectional study was conducted among 209 patients with RA. Of them, 74 with RA of short evolution (= 2 years). The following indicators were evaluated: RhF by latex agglutination (RhF-A), RhF by automated immunoturbidimetry (RhF-T), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), Disease Activity Score 28 (DAS 28), functional disability index (Health Assessment Questionnaire score, HAQ), and the presence of radiological erosions. Results: 77 percent of the RhF-A positive patients and 73 percent of the RhF-T positive patients presented radiological erosions in contrast with 38 percent of the RhF-A negative patients (p<0.001) and with 14 percent of the RhF-T negative cases (p<0.001). The mean RhF-A figures of the patients according to the 4 grades of articular affectation (maximum: > 6 eroded articulations; minimum: 0 erosion; < 6 swollen articulations) were 484, 162, 57 and 17 UI/mL (p<0.001), whereas those of RhF-T were 277, 185, 22 and 33 UI/mL (p<0,01). The positive predictive value (PPV) for the erosion of RhF-A >512 UI/mL was 92 percent, and that of RhF-T >97 UI/mL was 96 percent. The mean values of DAS28 in the RhF-A and RhF-T positive patients were 5.04 and 4.94, respectively. In the negative, these values were 4.26 and 3.97 (p<0.001 for both). The HAQ values were 1.31 and 1.29 in the RhF-A and RhF-T positive patients, respectively, while in the negative they were 0.99 and 0.89 (p<0.01 for both). Correlation was found between the RhF figures by both methods and those of ESR, CRP, DAS28 and HAQ (p<0.05 or p<0.01). Conclusions: High levels of RhF correspond with a higher degree of inflammation and articular destruction in the rheumatoid arthritis.

Espondilitis anquilosante primaria: patrones clínicos en pacientes cubanos / Primary ankylosing spondylitis: clinical patterns in Cuban patients

Se estudiaron retrospectivamente 70 pacientes con diagnóstico de espondilitis anquilosante (EA) primaria, según los criterios de Nueva York modificados, para investigar sus patrones clínicos en pacientes cubanos. Los datos demográficos, clínicos y radiológicos fueron comparados según sexo, raza, edad de inicio de la EA y status del antígeno HLA-B27. Se encontró predominio de pacientes del sexo masculino (80,0 por ciento), de raza caucásica (82,9 por ciento), de inicio de la EA en la adultez (90,0 por ciento), y positivos de HLA-B27 (90,0 por ciento). Los antecedentes familiares de EA se registraron en 17,1 por ciento de los pacientes. La afectación axial pura se observó en 4,3 por ciento; la entesopatía, en 81,4 por ciento; y la artritis periférica, en 58,6 por ciento. La uveítis anterior aguda fue la manifestación extraarticular más frecuente (17,1 por ciento). El sexo masculino se asoció con insuficiencia aórtica y el femenino, con fibromialgia (p = 0,11); también el sexo se asoció con la ubicación de los pacientes, mientras los hombres procedieron del medio urbano, las mujeres lo hicieron del medio rural (p = 0,001). La raza no caucásica, a diferencia de la caucásica, fue sometida al reemplazo total de cadera (p = 0,027). Los pacientes con EA de inicio juvenil presentaron con mayor frecuencia artritis periférica (p = 0,019), y necesitaron reemplazo total de cadera (p = 0,003). Los pacientes positivos de HLA-B27 presentaron con mayor frecuencia, sacroileítis bilateral grados 3 y 4 (p = 0,009), dolor bajo de espalda (p = 0,023), entesopatía (p = 0,006), y un tiempo de duración más largo de la EA que los pacientes negativos para este alelo (8,1 y 3,6 años, p = 0,021). Se concluyó que el sexo marcó diferencias en las manifestaciones extraarticulares de la EA, la raza caucásica y la no caucásica presentaron manifestaciones clínicas similares, el inicio juvenil de la EA se caracterizó por la artritis periférica, y la presencia del HLA-B27 se asoció a manifestaci...

Utilización y valor predictivo de la determinación de anticuerpos antinucleares en un Hospital de Referencia Nacional de Salud / Use and predictive value of the determination of antinuclear antibodies in a national health reference hospital

Se hizo una revisión retrospectiva de datos clínicos y demográficos en un Hospital de Referencia Nacional de Salud de 950 camas. Se tomó una muestra consecutiva de pacientes hospitalizados y ambulatorios con solicitud médica de anticuerpos antinucleares por inmunofluorescencia indirecta (AAN-IFI) en un período de 18 meses para definir el valor predictivo positivo (VPP) y negativo (VPN) de los AAN-IFI, anticuerpos anti-DNA de doble cadena (anti-DNAdc) y anti-antígenos nucleares extraíbles (anti-ENA) para el diagnóstico del LES y de las conectivopatías, y el VPP y VPN de los AAN-IFI para la detección de los anticuerpos anti-DNAdc y anti-ENA. Se halló que 2 113 pacientes han sido referidos para la determinación de AAN-IFI, de los cuales a 273 se les determinó además anticuerpos anti-DNA de doble cadena (anti-DNAdc) y a 233 anti-antígenos nucleares extraíbles (anti-ENA); 651fueron registrados con el diagnóstico de enfermedad del tejido conectivo (ETC) y de estos, 97 con lupus eritematoso sistémico (LES). Los valores predictivos de los resultados positivos de AAN-IFI para las ETC y el LES fueron de 59,8 y 22,8 por ciento, respectivamente, mientras que el de anti-ENA para las ETC fue 99,0 por ciento, y el de anti-DNAdc para el LES fue 97,3 por ciento. Los valores predictivos de los resultados negativos de AAN-IFI para las ETC y el LES fueron de 76,0 y 99,7 por ciento, respectivamente, mientras que el de anti-ENA para las ETC fue 28,4 por ciento, y el de anti-DNAdc para el LES fue 87,9 por ciento. Se concluyó que la mayor parte de los resultados de AAN-IFI fueron negativos y solicitados en pacientes sin conectivopatías, lo que dio lugar a valores predictivos bajos y una utilidad clínica cuestionable. Estos datos sugieren una sobreutilización inadecuada de la prueba de AAN-IFI, fuera de un contexto clínico lógico. Esta situación puede corregirse con una esmerada preselección de los pacientes basada en la presencia de varios criterios clínicos reconocidos...

Invertebrate modeling of a migraine channelopathy.

Migraine is a chronic episodic disorder that has been linked to abnormalities in serotonin signaling and abnormal function of a presynaptic voltage-gated calcium channel, CACNA1A. Although the importance of serotonin to migraine tendency suggests a link between serotonergic signaling and CACNA1A function, the nature of this connection remains unclear in vertebrate studies. This article reviews findings, based on an invertebrate model of CACNA1A dysfunction, which suggest a potential connection between serotonergic and calcium channel abnormalities in migraine. Neurons of the invertebrate species Caenorhabditis elegans express a voltage-gated calcium channel, UNC-2, which is the closest ortholog in C. elegans of human CACNA1A. Mutations in unc-2, the gene that encodes this invertebrate channel, cause the animals to be lethargic and uncoordinated. By identifying the genes that could be altered in such a way as to suppress the lethargic phenotype of unc-2, a signaling pathway has been identified through which UNC-2 calcium channel function antagonizes a transforming growth factor-beta (TGF-beta) pathway modulating locomotion. In C. elegans, serotonergic signaling can inhibit the rate of movement. The UNC-2/transforming growth factor-beta pathway identified regulates the expression of a gene encoding the rate-limiting enzyme for serotonin synthesis, tryptophan hydroxylase. The evolutionary and functional relationship between the UNC-2 channel and the migraine-associated CACNA1A channel was further confirmed through experiments showing that transgenic expression of human CACNA1A can suppress the lethargic and serotonin-deficient phenotypes of unc-2 mutant animals. The findings in this invertebrate model constitute the first direct demonstration of how CACNA1A function might affect the levels of serotonin, a neurotransmitter known to be important in migraine.

Both insulin and calcium channel signaling are required for developmental regulation of serotonin synthesis in the chemosensory ADF neurons of Caenorhabditis elegans.

Proper calcium channel and insulin signaling are essential for normal brain development. Leaner mice with a mutation in the P/Q-type voltage-gated calcium channel, Cacna1a, develop cerebellar atrophy and mutations in the homologous human gene are associated with increased migraine and seizure tendency. Similarly, abnormalities in insulin signaling are associated with abnormal brain growth and migraine tendency. Previously, we have shown that in the ADF chemosensory neurons of Caenorhabditis elegans UNC-2/Ca(2+) channel function affects TGF-beta-dependent developmental regulation of tryptophan hydroxylase, the rate-limiting enzyme in serotonin synthesis. Here we show that developmental expression of a tryptophan hydroxylase: :GFP reporter construct is similarly decreased by reduction-of-function mutations in the daf-2/insulin receptor. This decreased expression of tryptophan hydroxylase observed in both the daf-2 and unc-2 mutant backgrounds is suppressible either genetically by reduction-of-function mutations in the daf-16/forkhead transcription factor, an effector of the DAF-2/insulin receptor, or pharmacologically by the serotonin receptor antagonist cyproheptadine. Overall, these data suggest that both UNC-2 and DAF-2 function are required in the developmental regulation of DAF-16 and serotonin-dependent inhibition of tryptophan hydroxylase expression.

The voltage-gated calcium channel UNC-2 is involved in stress-mediated regulation of tryptophan hydroxylase.

Migraine is an episodic pain disorder whose pathophysiology is related to deficiency of serotonin signaling and abnormal function of the P/Q-type calcium channel, CACNA1A. Because the relationship of the CACNA1A channel to serotonin signaling is unknown and potentially of therapeutic interest we have used genetic analysis of the Caenorhabditis elegans ortholog of this calcium channel, UNC-2, to help identify candidate downstream effectors of the human channel. By genetic dissection of the lethargic mutant phenotype of unc-2, we have established an epistasis pathway showing that UNC-2 function antagonizes a transforming growth factor (TGF)-beta pathway influencing movement rate. This same UNC-2/TGF-beta pathway is required for accumulation of normal serotonin levels and stress-induced modulation of tryptophan hydroxylase (tph) expression in the serotonergic chemosensory ADF neurons, but not the NSM neurons. We also show that transgenic expression of the migraine-associated Ca2+ channel, CACNA1A, in unc-2 animals can functionally substitute for UNC-2 in stress-activated regulation of tph expression. The demonstration that these evolutionarily related channels share a conserved ability to modulate tph expression through their effects on TGF-beta signaling provides the first specific example of how CACNA1A function may influence levels of the critical migraine neurotransmitter serotonin.