Tiempos de llegada de pacientes con ataque cerebrovascular en un hospital regional de alta complejidad / Arrival times of patients with stroke to a public hospital

Background: Stroke is a time-dependent emergency. Most patients with acute ischemic stroke are excluded from reperfusion therapies due to late consultation. Aims: To estimate the arrival times of patients with stroke to the Emergency Room (ER) of a public hospital. To identify factors associated with early consultation. Material and Methods: A convenience sample, 583 patients aged 71 ± 13 years (55% males) consulting for stroke at an emergency room was analyzed in terms of delay between onset of symptoms and arrival to the ER, demographics and etiology of stroke. Results: The admission diagnoses were ischemic stroke in 76%, intracerebral hemorrhage in 12%, transient ischemic attack in 9% and subarachnoid hemorrhage in 3%. The median time of arrival was 8 hours and 11 minutes after the onset of symptoms. Nineteen percent of consultations for ischemic stroke occurred within 3 hours of symptom onset, and 38% within 6 hours. In the logistic regression analysis, having an address near the hospital and the severity of stroke were associated with early consultation with a combined odds ratio of 5.97 (95% confidence intervals 3.23-11.04). Conclusions: There were significant differences in the arrival times of patients with stroke. Only a low proportion of patients with ischemic stroke consulted within the window for reperfusion therapies. Severe strokes and living near the hospital were associated with early consultation.

Factores asociados a llegada y evaluación precoz de pacientes con ataque cerebrovascular en un hospital regional de alta complejidad / Factors associated with early arrival and evaluation of stroke patients in a regional tertiary hospital

Resumen Antecedentes: El ataque cerebrovascular (ACV) es una urgencia tiempo-dependiente. La mayoría de los pacientes con infarto cerebral quedan excluidos de las terapias de reperfusión por consultar tardíamente. Se desconocen los factores asociados a llegada y evaluación precoz de pacientes con ACV agudo en nuestra población. Objetivos: Identificar los factores asociados, llegada y evaluación precoz de pacientes con ACV agudo. Pacientes y Métodos: Muestra por conveniencia de las consultas por ACV realizadas en el Turno N° 1, del SU del Hospital Dr. Hernán Henríquez de Temuco, entre enero de 2016 y diciembre de 2017. El análisis estadístico se realizó con el software STATA 14.0. Resultados: Se registraron 584 consultas por ACV. La mediana del tiempo de llegada fue de 8 h y 11 min. La mediana del tiempo para la evaluación por neurólogo(a) fue de 66 min. Tener domicilio en Temuco-Padre Las Casas y una mayor severidad del ACV se asociaron a consultar precozmente con un OR = 5,97 (3,23-11,04). Para evaluación dentro de una hora, las variables severidad, llegada en ambulancia y consulta en menos de 3 h, fueron estadísticamente significativas, con un OR combinado de 10,86 (IC 95%: 5,15-22,94). Conclusiones: Los factores más fuertemente asociados a llegada y evaluación precoz incluyen residir en comunas cercanas al hospital y presentar síntomas más severos de ACV. Se sugiere implementar estrategias para aumentar el grado de reconocimiento de síntomas de ACV y para disminuir las barreras de acceso a hospitales que traten a este tipo pacientes.

Introduction: Stroke is a time-dependent emergency. The majority of patients with Acute Ischemic Stroke are excluded from reperfusion therapies due to late consultation. The factors associated with early arrival and evaluation of patients with acute stroke in our population are unknown. The aim of the study was to identify factors associated with early arrival and evaluation of patients with acute stroke. Methods: A convenience sample of the stroke consultations made during shift # 1 at the ER between January 2016 and December 2017, was analyzed. Results: There were 584 stroke consultations in the period. 55.1% were men. The median time of arrival was 8 hours and 11 minutes. The median time for evaluation by neurologist was 66 minutes. Having an address in Temuco-Padre Las Casas and the severity of stroke was associated with early consultation with a combined OR of 5.97 (CI 95% 3.23-11.04). For an evaluation within one hour, in the logistic regression model, the variables severity, arrival in ambulance and consultation in less than 3 hours were statistically significant with a combined OR of 10.86 (CI 95% 5.15-22.94). Conclusions: The factors associated with early consultation and evaluation include residing in communes near the hospital and presenting more severe symptoms of stroke. It is suggested to implement strategies to increase the degree of recognition of stroke symptoms and to reduce barriers to access hospitals that treat patients with stroke.

Molecular mechanisms involved in the protective actions of Selective Estrogen Receptor Modulators in brain cells.

Synthetic selective modulators of the estrogen receptors (SERMs) have shown to protect neurons and glial cells against toxic insults. Among the most relevant beneficial effects attributed to these compounds are the regulation of inflammation, attenuation of astrogliosis and microglial activation, prevention of excitotoxicity and as a consequence the reduction of neuronal cell death. Under pathological conditions, the mechanism of action of the SERMs involves the activation of estrogen receptors (ERs) and G protein-coupled receptor for estrogens (GRP30). These receptors trigger neuroprotective responses such as increasing the expression of antioxidants and the activation of kinase-mediated survival signaling pathways. Despite the advances in the knowledge of the pathways activated by the SERMs, their mechanism of action is still not entirely clear, and there are several controversies. In this review, we focused on the molecular pathways activated by SERMs in brain cells, mainly astrocytes, as a response to treatment with raloxifene and tamoxifen.

[Arrival times of patients with stroke to a public hospital]. / Tiempos de llegada de pacientes con ataque cerebrovascular en un hospital regional de alta complejidad.

BACKGROUND: Stroke is a time-dependent emergency. Most patients with acute ischemic stroke are excluded from reperfusion therapies due to late consultation. AIMS: To estimate the arrival times of patients with stroke to the Emergency Room (ER) of a public hospital. To identify factors associated with early consultation. MATERIAL AND METHODS: A convenience sample, 583 patients aged 71 ± 13 years (55% males) consulting for stroke at an emergency room was analyzed in terms of delay between onset of symptoms and arrival to the ER, demographics and etiology of stroke. RESULTS: The admission diagnoses were ischemic stroke in 76%, intracerebral hemorrhage in 12%, transient ischemic attack in 9% and subarachnoid hemorrhage in 3%. The median time of arrival was 8 hours and 11 minutes after the onset of symptoms. Nineteen percent of consultations for ischemic stroke occurred within 3 hours of symptom onset, and 38% within 6 hours. In the logistic regression analysis, having an address near the hospital and the severity of stroke were associated with early consultation with a combined odds ratio of 5.97 (95% confidence intervals 3.23-11.04). CONCLUSIONS: There were significant differences in the arrival times of patients with stroke. Only a low proportion of patients with ischemic stroke consulted within the window for reperfusion therapies. Severe strokes and living near the hospital were associated with early consultation.

[Waiting times for neurological emergencies in an emergency room]. / Tiempos de atención de urgencias neurológicas en un hospital regional de alta complejidad.

BACKGROUND: Neurological emergencies constitute 10-15% of medical emergencies. Doctor Hernán Henríquez Aravena Hospital has in house neurologists present permanently at the Emergency Room since July 2013. AIM: To estimate the waiting times for neurological consultations; to compare the waiting times between neurovascular (UV) and non-vascular (UNV) emergencies; and to compare the waiting times of two prioritization (triage) models. MATERIAL AND METHODS: A convenience sample of the consultations made during shift # 1 at the emergency room between January and December 2016, was analyzed. RESULTS: There were 859 consultations in the period, 570 for UNV and 289 for UV. Mean age of consultants was 57 years and 52% were women. The median time for having an evaluation by a neurologist was 106 min (132 and 81 min for UNV and UV respectively). Twenty seven percent of patients were evaluated in less than one hour (23 and 36% of UNV and UV, respectively). The change of the prioritization model decreased the waiting time by 81 and 32 min for UNV and UV, respectively. CONCLUSIONS: There were significant differences in waiting times between neurovascular and non-vascular emergencies. Most patients were not evaluated in less than 60 minutes. The change in the initial stratification model was associated with a significant reduction in the waiting times for neurological emergencies.

Tiempos de atención de urgencias neurológicas en un hospital regional de alta complejidad / Waiting times for neurological emergencies in an emergency room

Background: Neurological emergencies constitute 10-15% of medical emergencies. Doctor Hernán Henríquez Aravena Hospital has in house neurologists present permanently at the Emergency Room since July 2013. Aim: To estimate the waiting times for neurological consultations; to compare the waiting times between neurovascular (UV) and non-vascular (UNV) emergencies; and to compare the waiting times of two prioritization (triage) models. Material and Methods: A convenience sample of the consultations made during shift # 1 at the emergency room between January and December 2016, was analyzed. Results: There were 859 consultations in the period, 570 for UNV and 289 for UV. Mean age of consultants was 57 years and 52% were women. The median time for having an evaluation by a neurologist was 106 min (132 and 81 min for UNV and UV respectively). Twenty seven percent of patients were evaluated in less than one hour (23 and 36% of UNV and UV, respectively). The change of the prioritization model decreased the waiting time by 81 and 32 min for UNV and UV, respectively. Conclusions: There were significant differences in waiting times between neurovascular and non-vascular emergencies. Most patients were not evaluated in less than 60 minutes. The change in the initial stratification model was associated with a significant reduction in the waiting times for neurological emergencies.

The HLA-A*02:481 allele was identified in unrelated Brazilians sharing HLA-B*15:17, C*07:01P, DRB1*13:02 and DQB1*06:04.

HLA-A*02:481 differs from HLA-A*02:01:01:01 by one nucleotide and was found in four unrelated Brazilians.

Sorafenib inhibits nuclear factor kappa B, decreases inducible nitric oxide synthase and cyclooxygenase-2 expression, and restores working memory in APPswe mice.

Alzheimer's disease (AD) is characterized by memory loss and the upregulation of pro-neuroinflammatory factors such as cRaf-1, cyclooxygenase-2 (Cox-2), and the nuclear factor kappa B (NF-kappaB), as well as a downregulation of protein kinase A (PKA) activity and the activation by phosphorylation of its downstream factor CREB. We investigated the effect of the anti-cancer cRaf-1 inhibitor, sorafenib tosylate (Nexavar), on the expression of these factors and on the cognitive performance of aged APPswe mice. We found that chronic treatment with sorafenib stimulated PKA and CREB phosphorylation and inhibited cRaf-1 and NF-kappaB in the brains of APPswe mice. NF-kappaB controls the expression of several genes related to AD pathology, including iNOS and Cox-(2)Concurrent with NF-kappaB inhibition, sorafenib treatment decreased the cerebral expression of Cox-2 and iNOS in APPswe mice. It has recently been observed that Cox-2 inhibition prevents cognitive impairment in a mouse model of AD and amyloid beta peptide (Abeta)-induced inhibition of long-term potentiation (LTP). Consistent with the idea that Cox-2 inhibition can improve cognitive abilities, we found that sorafenib restored working memory abilities in aged APPswe mice without reducing Abeta levels in the brain. These findings suggest that sorafenib reduced AD pathology by reducing neuroinflammation.

Endogenous beta-amyloid peptide synthesis modulates cAMP response element-regulated gene expression in PC12 cells.

Extracellular-regulated kinases play a fundamental role in several neuroplasticity processes. In order to test whether endogenous beta-amyloid peptides play a role in the activation of extracellular-regulated kinase, we investigated the Rap1-extracellular-regulated kinase pathway in PC12 cells expressing human beta-amyloid precursor protein containing familial Alzheimer's disease mutations. In PC12 cells transfected with mutant human beta-amyloid precursor proteins that lead to higher levels of endogenous beta-amyloid, we observed an up-regulation of phospho-extracellular-regulated kinase and higher levels of activity-induced cAMP response element-directed gene expression. These results suggest that moderate levels of endogenous beta-amyloid peptides stimulate cAMP response element-directed gene expression. This stimulation was via a Rap1/MEK/extracellular-regulated kinase signaling pathway, as it was blocked by inhibition of Rap1 and MEK activities, and it requires beta-amyloid precursor protein cleavage at the gamma-site as it was abolished by a gamma-secretase inhibitor. Interestingly, in agreement with the previous observations, micromolar levels of extracellular fibrillar beta-amyloid blocked the cAMP response element-regulated gene expression stimulated by potassium and forskolin. This indicates that beta-amyloid can provoke different responses on cAMP response element-directed gene expression, such that low beta-amyloid levels may play a physiological role favoring synaptic plasticity under normal conditions while it would inhibit this mechanism under pathological conditions.

Altered mitogen-activated protein kinase signaling, tau hyperphosphorylation and mild spatial learning dysfunction in transgenic rats expressing the beta-amyloid peptide intracellularly in hippocampal and cortical neurons.

The pathological significance of intracellular Abeta accumulation in vivo is not yet fully understood. To address this, we have studied transgenic rats expressing Alzheimer's-related transgenes that accumulate Abeta intraneuronally in the cerebral and hippocampal cortices but do not develop extracellular amyloid plaques. In these rats, the presence of intraneuronal Abeta is sufficient to provoke up-regulation of the phosphorylated form of extracellular-regulated kinase (ERK) 2 and its enzymatic activity in the hippocampus while no changes were observed in the activity or phosphorylation status of other putative tau kinases such as p38, glycogen synthase kinase 3, and cycline-dependent kinase 5. The increase in active phospho-ERK2 was accompanied by increased levels of tau phosphorylation at S396 and S404 ERK2 sites and a decrease in the phosphorylation of the CREB kinase p90RSK. In a water maze paradigm, male transgenic rats displayed a mild spatial learning deficit relative to control littermates. Our results suggest that in the absence of plaques, intraneuronal accumulation of Abeta peptide correlates with the initial steps in the tau-phosphorylation cascade, alterations in ERK2 signaling and impairment of higher CNS functions in male rats.

The DREAM-DRE interaction: key nucleotides and dominant negative mutants.

Transcriptional repressor DREAM, an EF-hand containing calcium-binding protein, blocks basal expression of target genes through specific interaction with DRE sites in the DNA. The sequence GTCA forms the central core of the DRE site, whereas flanking nucleotides contribute notably to the affinity for DREAM. Release of binding of DREAM from the DRE results in derepression, a process that is regulated by Ca(2+). Change of two amino acids within an EF-hand in DREAM blocks Ca(2+)-induced derepression and results in potent dominant negative mutants of endogenous DREAM.

Mutagenesis in the switch IV of the helical domain of the human Gsalpha reduces its GDP/GTP exchange rate.

The Galpha subunits of heterotrimeric G proteins are constituted by a conserved GTPase "Ras-like" domain (RasD) and by a unique alpha-helical domain (HD). Upon GTP binding, four regions, called switch I, II, III, and IV, have been identified as undergoing structural changes. Switch I, II, and III are located in RasD and switch IV in HD. All Galpha known functions, such as GTPase activity and receptor, effector, and Gbetagamma interaction sites have been found to be localized in RasD, but little is known about the role of HD and its switch IV region. Through the construction of chimeras between human and Xenopus Gsalpha we have previously identified a HD region, encompassing helices alphaA, alphaB, and alphaC, that was responsible for the observed functional differences in their capacity to activate adenylyl cyclase (Antonelli et al. [1994]: FEBS Lett 340:249-254). Since switch IV is located within this region and contains most of the nonconservative amino acid differences between both Gsalpha proteins, in the present work we constructed two human Gsalpha mutant proteins in which we have changed four and five switch IV residues for the ones present in the Xenopus protein. Mutants M15 (hGsalphaalphaS133N, M135P, P138K, P143S) and M17 (hGsalphaalphaS133N, M135P, V137Y, P138K, P143S) were expressed in Escherichia coli, purified, and characterized by their ability to bind GTPgammaS, dissociate GDP, hydrolyze GTP, and activate adenylyl cyclase. A decreased rate of GDP release, GTPgammaS binding, and GTP hydrolysis was observed for both mutants, M17 having considerably slower kinetics than M15 for all functions tested. Reconstituted adenylyl cyclase activity with both mutants showed normal activation in the presence of AlF(4)(-), but a decreased activation with GTPgammaS, which is consistent with the lower GDP dissociating rate they displayed. These data provide new evidence on the role that HD is playing in modulating the GDP/GTP exchange of the Gsalpha subunit.

The C2 cytosolic loop of adenylyl cyclase interacts with the activated form of G alpha s.

Using the yeast two-hybrid system, we studied the physical interaction between the complete C1 and C2 cytosolic domains of Xenopus laevis type 9 (xl9C1, xl9C2) and the C2 domain of rat type 6 (r6C2) adenylyl cyclase (AC). Heterodimerization between xl9C1 and xl9C2 and homodimerization between C2 (but not C1) domains was observed. Interaction between C2 and human G alpha s (hG alpha s) was also detected and was dependent on G alpha s activation. In contrast X. laevis G alpha s (xlG alpha s), which is 92% identical to hG alpha s, was unable to interact with any of the three AC cytosolic domains tested, corroborating previous findings that showed no effector activation. Through the construction of chimeras, we demonstrated that the amino-terminal half of xlG alpha s was responsible for the lack of interaction with AC. Chimeras between mouse G alpha i2 and G alpha s (N-mG alpha i2/C-G alpha s), that have previously shown to activate AC to a higher extent than wild-type G alpha s, also interacted with the C2 cytosolic domain and with a higher affinity. Interestingly, N-mG alpha i2/C-xlG alpha s chimera was not only able to interact with C2 but also with the C1 cytosolic domain.

Molecular cloning and expression of an adenylyl cyclase from Xenopus laevis oocytes.

We have cloned a cDNA that encodes a novel Xenopus laevis oocyte adenylyl cyclase (xlAC) using oligonucleotides against conserved mammalian adenylyl cyclase regions. The isolated cDNA is 4372 bp long with an open reading frame of 4065 nucleotides which encodes a protein of 1355 amino acids. Comparison of the deduced amino acid sequence with previously cloned mammalian adenylyl cyclases shows a low identity, 19.7% with type 2 rat adenylyl cyclase and 24.2% with type 4 rat adenylyl cyclase, indicating that this Xenopus isoform represents a new member of this protein family. Gene expression studies of the xlAC by reverse PCR showed that this gene is expressed in all oogenesis stages but not during early embryogenesis. Expression of the xlAC in COS-7 cells resulted in increased basal AC activity, that was stimulated by forskolin, Gpp(NH)p and aluminium fluoride, and was insensitive to calcium and calcium-calmodulin (Ca2(+)-CaM).

Partial DNA sequence of a beta-lactamase produced by a Shigella flexneri strain.

A probe was constructed by radioactive labelling, and enzymatically a DNA fragment of plasmid pMAM-1, which codes for a beta-lactamase in Shigella flexneri UCSM 129, was obtained by amplification of a small part of the gene using the polymerase chain reaction technique (PCR). Since previous published work indicated that this beta-lactamase was of the TEM type, the primers used to amplify the gene were two highly conserved DNA regions in all TEM beta-lactamases. A 500 bp DNA probe was obtained which, by hybridization assays, facilitated the identification of restriction fragments of the plasmid containing the beta-lactamase gene. Two DNA fragments were sequenced by the Sanger method adapted to the PCR technique, and the sequence obtained showed a 100% homology with beta-lactamases TEM-1, TEM-2, TEM-13 and TEM-19. An intragenic restriction site, detected for Pst I, suggested that there is only one copy of the beta-lactamase gene per plasmid copy.

[Gelastic seizures, precocious puberty and hypothalamic hamartomas. A case report and the contributions of Single Photon Emission Computed Tomography (SPECT)]. / Síndrome de crisis gelásticas, pubertad precoz y hamartoma hipotalámico. Presentación de un caso y aportaciones del SPECT.

We present a patient with gelastic seizures, precocious puberty and a hypothalamic hamartoma. The diagnostic method of choice for hypothalamic hamartoma is new generation MRI. The characteristic MRI images along with lack of growth during the course of disease indicates a diagnosis of hamartoma firmly with no need for pathological studies. Although the physical nature of gelastic seizures in this syndrome is a subject of dispute, SPECT findings point to activity at a distance from nerve routes connecting the hypothalamus to the cortical regions (the temporal region in this case). Prognosis improves if the various components of the syndrome are treated early and when dysgenesis is less extensive.

Characterization of a plasmid codifying the synthesis of a beta-lactamase produced by Shigella flexneri.

The resistance to beta-lactam antibiotics shown by a strain of Shigella flexneri was plasmid-coded. This plasmid, pMAM-1, when transferred to Escherichia coli K-12 by conjugation, presented the same molecular weight (100 kbp) and conferred the same high level of resistance to ampicillin in the transconjugant as in the wild type strains (MIC, 2048-4096). Restriction analysis of the plasmid in transconjugants revealed various restrictive sites to some endonucleases (i.e. Bam HI, Eco RI, Pst I, Nco I, Cla I, Sf I and Sau 3AI, Nhe and Hin dIII), and no restrictive sites at all for other endonucleases (such as Xho I, Dra I, Kpn I, and Sal I). Some restricted DNA fragments were appropriate for cloning and isolation of the beta-lactamase gene present in Shigella flexneri UCSF 129. This work provides the first step in this direction.

Cytomorphologic differentiation of common acute lymphoblastic leukemia from other immunologic subtypes. Report of a case of peripheral relapse with cytochemical and immunochemical study.

Of the subtypes of acute lymphoblastic leukemia (ALL), the "common" subtype (c-ALL) bears the best prognosis. Nevertheless, there has been no report of cytologic criteria that can distinguish c-ALL from the B-cell (B-ALL) and T-cell (T-ALL) subtypes. We present a case of c-ALL with relapse, with cytochemical and immunocytochemical as well as cytologic studies. Certain cytologic observations in this case could serve to differentiate c-ALL from B-ALL and T-ALL; the morphologic criteria suggested have been seen by us in other c-ALL cases. We think they will be useful in future fine needle aspiration studies in order to demonstrate extramedullary relapses as well as to differentiate ALL subtypes without the need of more costly immunologic studies.