Bacterial community assessment of drinking water and downstream distribution systems in highland localities of Ecuador

Bacterial communities in drinking water provide a gauge to measure quality and confer insights into public health. In contrast to urban systems, water treatment in rural areas is not adequately monitored and could become a health risk. We performed 16S rRNA amplicon sequencing to analyze the microbiome present in the water treatment plants at two rural communities, one city, and the downstream water for human consumption in schools and reservoirs in the Andean highlands of Ecuador. We tested the effect of water treatment on the diversity and composition of bacterial communities. A set of physicochemical variables in the sampled water was evaluated and correlated with the structure of the observed bacterial communities. Predominant bacteria in the analyzed communities belonged to Proteobacteria and Actinobacteria. The Sphingobium genus, a chlorine resistance group, was particularly abundant. Of health concern in drinking water reservoirs were Fusobacteriaceae, Lachnospiraceae, and Ruminococcaceae; these families are associated with human and poultry fecal contamination. We propose the latter families as relevant biomarkers for establishing local standards for the monitoring of potable water systems in highlands of Ecuador. Our assessment of bacterial community composition in water systems in the Ecuadorian highlands provides a technical background to inform management decisions.

Prevalence and Risk Factors of Eimeria spp. in Broiler Chickens from Pichincha and Santo Domingo de los Tsáchilas, Ecuador

Coccidiosis in chickens is a parasitic disease of economic importance for the poultry industry. In Ecuador, there is limited information regarding the prevalence of Eimeria spp. on commercial broiler farms. Therefore, a total of 155 poultry farms in the provinces of Pichincha and Santo Domingo de los Tsáchilas were surveyed. The analysis of fresh fecal samples was conducted to determine the parasitic load of six of the seven chicken Eimeria species (excluding E. mitis) through multiplex PCR. Additionally, an epidemiological survey was performed to assess the risk factors associated with the infection using a multivariable logistic regression model. All samples tested positive for the presence of Eimeria spp., despite the farmers having implemented prophylactic measures, and no clinical coccidiosis cases were recorded. The parasitic load varied between 25 and 69,900 oocyst per gram. The species prevalence was as follows: Eimeria spp. 100%, E. maxima 80.4%, E. acervulina 70.6%, E. praecox 55.4%, E. tenella 53.6%, E. necatrix 52.2%, and E. brunetti 30.8%. The main species combination was E. cervuline, E. maxima, E. necatrix, and E. praecox (23.90%), followed by E. tenella, as a unique species (10.69%), and then E. acervulina, E. maxima, and E. praecox (8.81%). It was observed that farms operated by independent producers had a higher amount of Eimeria spp. and higher probability of the presence of E. brunetti, E. necatrix, E. praecox, and E. tenella. Poultry houses located below 1300 m above sea level were associated with a higher parasitic load and the presence of E. brunetti. Birds younger than 35 days of age and from open-sided poultry houses (with rudimentary environmental control) had a higher probability of presenting E. maxima. Drinking water from wells increased the risk of E. praecox presence. Research aimed at designing control strategies to improve health management on poultry farms in the region would help minimize the impact of coccidiosis.

Management of acute stroke. Specific nursing care and treatments in the stroke unit

OBJECTIVE

This study provides a series of updated, evidence-based recommendations for the management of acute stroke. We aim to lay a foundation for the development of individual centres' internal protocols, serving as a reference for nursing care.

METHODS

We review the available evidence on acute stroke care. The most recent national and international guidelines were consulted. Levels of evidence and degrees of recommendation are based on the Oxford Centre for Evidence-Based Medicine classification.

RESULTS

The study describes prehospital acute stroke care, the operation of the code stroke protocol, care provided by the stroke team upon the patient's arrival at hospital, reperfusion treatments and their limitations, admission to the stroke unit, nursing care in the stroke unit, and discharge from hospital.

CONCLUSIONS

These guidelines provide general, evidence-based recommendations to guide professionals who care for patients with acute stroke. However, limited data are available on some aspects, showing the need for continued research on acute stroke management.

Beta-Lactam Antibiotic Resistance Genes in the Microbiome of the Public Transport System of Quito, Ecuador

Multidrug-resistant bacteria present resistance mechanisms against β-lactam antibiotics, such as Extended-Spectrum Beta-lactamases (ESBL) and Metallo-β-lactamases enzymes (MBLs) which are operon encoded in Gram-negative species. Likewise, Gram-positive bacteria have evolved other mechanisms through mec genes, which encode modified penicillin-binding proteins (PBP2). This study aimed to determine the presence and spread of β-lactam antibiotic resistance genes and the microbiome circulating in Quito's Public Transport (QTP). A total of 29 station turnstiles were swabbed to extract the surface environmental DNA. PCRs were performed to detect the presence of 13 antibiotic resistance genes and to identify and to amplify 16S rDNA for barcoding, followed by clone analysis, Sanger sequencing, and BLAST search. ESBL genes bla_TEM-1 and bla_CTX-M-1 and MBL genes bla_OXA-181 and mecA were detected along QPT stations, blaTEM being the most widely spread. Two subvariants were found for bla_TEM-1, bla_CTX-M-1, and bla_OXA-181. Almost half of the circulating bacteria found at QPT stations were common human microbiota species, including those classified by the WHO as pathogens of critical and high-priority surveillance. β-lactam antibiotic resistance genes are prevalent throughout QPT. This is the first report of bla_OXA-181 in environmental samples in Ecuador. Moreover, we detected a new putative variant of this gene. Some commensal coagulase-negative bacteria may have a role as mecA resistance reservoirs.

The microbiome of the ice-capped Cayambe Volcanic Complex in Ecuador

A major challenge in microbial ecology is to understand the principles and processes by which microbes associate and interact in community assemblages. Microbial communities in mountain glaciers are unique as first colonizers and nutrient enrichment drivers for downstream ecosystems. However, mountain glaciers have been distinctively sensitive to climate perturbations and have suffered a severe retreat over the past 40  years, compelling us to understand glacier ecosystems before their disappearance. This is the first study in an Andean glacier in Ecuador offering insights into the relationship of physicochemical variables and altitude on the diversity and structure of bacterial communities. Our study covered extreme Andean altitudes at the Cayambe Volcanic Complex, from 4,783 to 5,583 masl. Glacier soil and ice samples were used as the source for 16S rRNA gene amplicon libraries. We found (1) effects of altitude on diversity and community structure, (2) the presence of few significantly correlated nutrients to community structure, (3) sharp differences between glacier soil and glacier ice in diversity and community structure, where, as quantified by the Shannon γ-diversity distribution, the meta-community in glacier soil showed more diversity than in glacier ice; this pattern was related to the higher variability of the physicochemical distribution of variables in the former substrate, and (4) significantly abundant genera associated with either high or low altitudes that could serve as biomarkers for studies on climate change. Our results provide the first assessment of these unexplored communities, before their potential disappearance due to glacier retreat and climate change.

Wyeomyia abebela Dyar & Knab, 1908 and W. coenonus Dyar & Knab, 1913: new mosquito records (Diptera, Culicidae) in the Choco Biosphere Reserve, Ecuador, a biodiversity hotspot

We report the first records of two mosquito species, Wyeomyia (Wyeomyia) abebela Dyar & Knab, 1908 and W. (Hystatomyia) coenonus Dyar & Knab, 1913, from the Choco Biosphere Reserve, a global biodiversity hotspot in Ecuador. We collected these mosquitoes in the Mashpi Lodge Reserve, a conserved natural area. Specimens were collected during their immature stages in bromeliads using a 375-ml absorber dropper. Our new data for W. abelela increases the geographical distribution of this species to include seven countries of America (Belize, Costa Rica, Guatemala, Honduras, Mexico, Panama, and Ecuador); W. coenonus is now known from two countries of America (Panama and Ecuador), and our records of W. abelela and W. coenonus are the first from South America.

B-type natriuretic peptide over N-terminal pro-brain natriuretic peptide to predict incident atrial fibrillation after cryptogenic stroke

BACKGROUND AND PURPOSE

B-type natriuretic peptide (BNP) and N-terminal pro-brain natriuretic peptide (NT-proBNP) are well-known surrogates of atrial fibrillation (AF) detection but studies usually present data on either BNP or NT-proBNP. The aim was to determine and directly compare the validity of the two biomarkers as a tool to predict AF and guide prolonged cardiac monitoring in cryptogenic stroke patients.

METHODS

Non-lacunar acute ischaemic stroke (<72 h) patients over 55 years of age with cryptogenic stroke after standard evaluation were included in the Crypto-AF study and blood was collected. BNP and NT-proBNP levels were determined by automated immunoassays. AF was assessed by 28 days' monitoring. Highest (optimizing specificity) and lowest (optimizing sensitivity) quartiles were used as biomarker cut-offs to build predictive models adjusted by sex and age. The integrated discrimination improvement index (IDI) and DeLong test were used to compare the performance of the two biomarkers.

RESULTS

From 320 patients evaluated, 218 were included in the analysis. AF was detected in 50 patients (22.9%). NT-proBNP (P < 0.001) and BNP (P < 0.001) levels were higher in subjects with AF and their levels correlated (r = 0.495, P < 0.001). BNP showed an increased area under the curve (0.720 vs. 0.669; P = 0.0218) and a better predictive capacity (IDI = 3.63%, 95% confidence interval 1.36%-5.91%) compared to NT-proBNP. BNP performed better than NT-proBNP in a specific model (IDI = 3.7%, 95% confidence interval 0.87%-6.5%), whilst both biomarkers performed similarly in the case of a sensitive model.

CONCLUSIONS

Both BNP and NT-proBNP were increased in cryptogenic stroke patients with AF detection. Interestingly, BNP outperforms NT-proBNP, especially in terms of specificity.

Management of acute stroke. Specific nursing care and treatments in the stroke unit

OBJECTIVE

This study provides a series of updated, evidence-based recommendations for the management of acute stroke. We aim to lay a foundation for the development of individual centres' internal protocols, serving as a reference for nursing care.

METHODS

We review the available evidence on acute stroke care. The most recent national and international guidelines were consulted. Levels of evidence and degrees of recommendation are based on the Oxford Centre for Evidence-Based Medicine classification.

RESULTS

The study describes prehospital acute stroke care, the operation of the code stroke protocol, care provided by the stroke team upon the patient's arrival at hospital, reperfusion treatments and their limitations, admission to the stroke unit, nursing care in the stroke unit, and discharge from hospital.

CONCLUSIONS

These guidelines provide general, evidence-based recommendations to guide professionals who care for patients with acute stroke. However, limited data are available on some aspects, showing the need for continued research on acute stroke management.

A parsimonious score with a free web tool for predicting disability after an ischemic stroke: the Parsifal Score

BACKGROUND

Most of the models to predict prognosis after an ischemic stroke include complex mathematical equations or too many variables, making them difficult to use in the daily clinic. We want to predict disability 3 months after an ischemic stroke in an independent patient not receiving recanalization treatment within the first 24 h, using a minimum set of variables and an easy tool to facilitate its implementation. As a secondary aim, we calculated the capacity of the score to predict an excellent/devastating outcome and mortality.

METHODS

Eight hundred and forty-four patients were evaluated. A multivariable ordinal logistic regression was used to obtain the score. The Modified Rankin Scale (mRS) was used to estimate disability at the third month. The results were replicated in another independent cohort (378 patients). The "polr" function of R was used to perform the regression, stratifying the sample into seven groups with different cutoffs (from mRS 0 to 6).

RESULTS

The Parsifal score was generated with: age, previous mRS, initial NIHSS, glycemia on admission, and dyslipidemia. This score predicts disability with an accuracy of 80-76% (discovery-replication cohorts). It has an AUC of 0.86 in the discovery and replication cohort. The specificity was 90-80% (discovery-replication cohorts); while, the sensitivity was 64-74% (discovery-replication cohorts). The prediction of an excellent or devastating outcome, as well as mortality, obtained good discrimination with AUC > 0.80.

CONCLUSIONS

The Parsifal Score is a model that predicts disability at the third month, with only five variables, with good discrimination and calibration, and being replicated in an independent cohort.

Identification, sequencing and comparative analysis of pBp15.S plasmid from the newly described entomopathogen Bacillus pumilus 15.1

The Bacillus pumilus 15.1 strain, a recently described entomopathogenic strain active against Ceratitis capitata, contains at least two extrachromosomal elements, pBp15.1S and pBp15.1B. Given that B. pumilus is not a typical entomopathogenic bacterium, the acquisition of this extrachromosomal DNA may explain why B. pumilus 15.1 is toxic to an insect. One of the plasmids present in the strain, the pBp15.1S plasmid, was sub-cloned, sequenced and analyzed using bioinformatics to identify any potential virulence factor. The pBp15.1S plasmid was found to be 7785 bp in size with a GC content of 35.7% and 11 putative ORFs. A replication module typical of a small rolling circle plasmid and a sensing and regulatory system specific for plasmids was found in pBp15.1S. Additionally, we demonstrated the existence of ssDNA in plasmid preparations suggesting that pBp15.1S replicates by the small rolling circle mechanism. A gene cluster present in plasmid pPZZ84 from a distantly isolated B. pumilus strain was also present in pBp15.1S. The plasmid copy number of pBp15.1S in exponentially growing B. pumilus cells was determined to be 33 copies per chromosome. After an extensive plasmid characterization, no known virulence factor was found so a search in the other extrachromosomal elements of the bacteria is needed.

Impact of blood pressure changes and course on hematoma growth in acute intracerebral hemorrhage

BACKGROUND AND PURPOSE

An association between high blood pressure (BP) in acute intracerebral hemorrhage (ICH) and hematoma growth (HG) has not been clearly demonstrated. Therefore, the impact of BP changes and course on HG and clinical outcome in patients with acute ICH was determined.

METHODS

In total, 117 consecutive patients with acute (<6 h) supratentorial ICH underwent baseline and 24-h CT scans, CT angiography for the detection of the spot sign and non-invasive BP monitoring at 15-min intervals over the first 24 h. Maximum and minimum BP, maximum BP increase and drop from baseline, and BP variability values from systolic BP (SBP), diastolic BP and mean arterial pressure (MAP) were calculated. SBP and MAP loads were defined as the proportion of readings >180 and >130 mmHg, respectively. HG (>33% or >6 ml), early neurological deterioration (END) and 3-month mortality were recorded.

RESULTS

Baseline BP variables were unrelated to either HG or clinical outcome. Conversely, SBP 180-load independently predicted HG (odds ratio 1.05, 95% CI 1.010-1.097, P = 0.016), whilst both SBP 180-load (odds ratio 1.04, 95% CI 1.001-1.076, P = 0.042) and SBP variability (odds ratio 1.2, 95% CI 1.047-1.380, P = 0.009) independently predicted END. Although none of the BP monitoring variables was associated with HG in the spot-sign-positive group, higher maximum BP increases from baseline and higher SBP and MAP loads were significantly related to HG in the spot-sign-negative group.

CONCLUSIONS

In patients with acute supratentorial ICH, SBP 180-load independently predicts HG, whilst both SBP 180-load and SBP variability predict END.

Decreased levels of angiogenic growth factors in intracranial atherosclerotic disease despite severity-related increase in endothelial progenitor cell counts

BACKGROUND

Intracranial atherosclerotic disease (ICAD) is an important cause of ischemic stroke (IS) and endothelial dysfunction plays a critical role in its onset and progression. Endothelial progenitor cells (EPCs) and endothelial production of angiogenic growth factors (AGFs) may play an essential role in this process. This study investigated the association of EPCs and AGFs with ICAD severity.

METHODS

A total of 42 patients who had experienced a transient ischemic attack (TIA) or IS attributable to symptomatic ICAD were included. Clinical and neurosonological evaluations were conducted between 2.4 and 8.7 years after the initial cerebrovascular event. Severe ICAD was defined as the presence of at least 1 severe intracranial stenosis, and extensive ICAD as 3 or more intracranial stenoses. Blood samples were obtained to determine EPC levels using flow cytometry (CD34+KDR+ cells), and the plasma levels of several growth factors were assessed with a protein array (Searchlight(®)). Twenty-two individuals without cerebrovascular disease and with normal ultrasonographic examination were also included.

RESULTS

No difference in the count of circulating EPCs was found between patients and controls, and a moderate increase in the number of EPCs/ml was noted in patients with extensive ICAD (p = 0.05). Patients presented decreased levels of fibroblast growth factor (FGF), vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF-BB) compared with controls (p = 0.002, p = 0.079 and p = 0.061, respectively). Higher levels of FGF, VEGF and PDGF-BB were found in patients with severe ICAD (p = 0.007, p = 0.07 and p = 0.07, respectively), but there was no correlation between any AGFs and EPCs.

CONCLUSIONS

Symptomatic ICAD patients have decreased levels of AGFs with no correlation to the number of circulating EPCs, while patients with severe ICAD have higher levels of EPCs, FGF, VEGF and PDGF-BBs. This suggests that reduced EPC and proangiogenic factor production capacity is implicated in ICAD pathogenesis, while the more severe forms of chronic brain hypoperfusion in ICAD patients might stimulate EPC mobilization and AGF production.

Brain natriuretic peptide is associated with worsening and mortality in acute stroke patients but adds no prognostic value to clinical predictors of outcome

BACKGROUND

At the present time, the determination of the outcome of stroke patients is based on the analysis of clinical and neuroimaging data. The use of prognostic blood biomarkers could aid in decision-making processes, e.g. admitting patients to specialized stroke units. Although the prognostic role of natriuretic peptides has been studied in heart failure and coronary diseases, the value of brain natriuretic peptide (BNP) is less known within the field of strokes.

OBJECTIVE

We aimed to study the relationship between plasma levels of BNP and acute neurological worsening or mortality after stroke in a large cohort of patients (investigating both ischemic and hemorrhagic disease).

METHODS

Consecutive stroke patients (ischemic and hemorrhagic) admitted to the Stroke Unit of our University Hospital within 24 h of the onset of symptoms were included. Stroke severity was assessed according to the National Institutes of Health Stroke Scale (NIHSS) at admission and at discharge. Neurological worsening was defined as an increase of 4 or more points in the NIHSS score or death during the patient's stay at the Stroke Unit. Blood samples were drawn upon admission to measure plasma levels of BNP (Biosite Inc., San Diego, Calif., USA). Statistical analysis was performed using SPSS 15.0 and R software.

RESULTS

Altogether, 896 patients were included in the study. BNP plasma levels were higher among patients who deteriorated the most over time (n = 112; 90.5 vs. 61.2 ng/l; p = 0.006) or died (n = 83; 118.2 vs. 60.9 ng/l; p < 0.001). Multivariate logistic regression analysis indicated that plasma BNP level was an independent predictor of neurological worsening [BNP >56.7 ng/l; odds ratio (OR) = 1.64; p = 0.04] and death after stroke (BNP >65.3 ng/l; OR = 1.97; p = 0.034). Adding BNP level to other well-known clinical predictors of bad outcome did not significantly increase the predictive value.

CONCLUSIONS

Plasma levels of BNP measured during the acute phase of stroke are associated both with early neurological worsening and mortality. However, this biological information does not supply prognostic information which would add to clinical variables, which limits its use as a biomarker. Further investigation and systematic reviews are needed to clarify the role of natriuretic peptides in stroke outcome.

[Endovenous thrombolysis in a district hospital using the telestroke system]

INTRODUCTION

In January 2007, a telestroke system was established between a community hospital lacking a neurologist on call and a stroke centre 70 km away for acute stroke care.

AIM

To study the impact of a telemedicine system for acute stroke care in a community hospital and the security of thrombolytic treatment.

PATIENTS AND METHODS

Observational study of acute stroke patients attended in the emergency room in a community hospital between 2007 and 2010.

RESULTS

662 acute stroke patients were attended. 133 'tele-consults' were done (37.6% ischemic stroke established). 39 patients (29.3%) were transferred to the stroke centre, 5 (12.8%) of them were considered unnecessary. 46 patients received thrombolytic treatment in the community hospital. The average time door-needle was 53.4 ± 38.2 minutes. 60.9% patients were treated during the first three hours since symptoms onset, and 100% in less than 4.5 hours. 9 patients received intra-arterial treatment. 4 patients (8.69%) presented hemorrhagic transformation 2 (4.3%) were symptomatic. 71.7% presented neurological improvement in 24 hours. 53.65% were functionally independent (mRS equal or less than 2) to three months. The mortality was 10.86%.

CONCLUSIONS

Tele-stroke allows a specialized attention for acute stroke in a community hospital, to administer thrombolytic treatment and could be an indispensable tool for select patient to transfer to the stroke centre for intra-arterial rescue procedures.

Leukoaraiosis is associated with genes regulating blood-brain barrier homeostasis in ischaemic stroke patients

BACKGROUND

The biologic agents causing leukoaraiosis are unknown. Our aim was to study the genetic basis of leukoaraiosis.

METHODS

We analyzed 212 single nucleotide polymorphisms (SNPs) in 142 patients with ischaemic stroke, generating a total of 30,104 genotypes. Seventy-nine subjects (55.6%) presented leukoaraiosis measured by the Fazekas scale and 69 (48.6%) by ARWMC scale. We analyzed the presence of synergic associations between SNPs using the hfcc software. Finally, functional studies were performed in 56 subjects. The Ingenuity Pathways software (ipa) was used to examine the role of the identified genes.

RESULTS

Six SNPs were associated with leukoaraiosis using both measuring scales. After logistic regression adjusted for leukoaraiosis risk factors, the rs2252070 of MMP13 (OR = 4.9, 95%CI: 1.34-17.9, P = 0.016), rs662 of PON1 (OR = 0.37, 95%CI: 0.15-0.87, P = 0.024) and rs1800779 of NOS3 (OR = 3.9, 95%CI: 1.38-11.38, P = 0.01) were independently associated with leukoaraiosis under a dominant/recessive model and the rs2290608 of IL5RA (OR = 0.46, 95%CI: 0.25-0.85, P = 0.013) and rs669 of A2M (OR = 2.5, 95%CI: 1.36-4.83, P = 0.004) under an additive model. Computational analysis showed a synergic association of rs10497212-AA of ITGB6 and rs2290608-GG of IL5RA with leukoaraiosis using both scales. (i) ARWMC (P = 1.3 × 10(-4) ) and (ii) Fazekas (P = 4.5 × 10(-5) ). Functional studies showed that the rs669 SNP was associated with plasma levels of A2M (P = 0.012) and A2M levels with leukoaraiosis in Fazekas scale (P = 0.02). ipa analysis revealed that the genes associated with leukoaraiosis were involved in blood-brain barrier (BBB) homeostasis.

CONCLUSIONS

Amongst patients with ischaemic stroke, several genes associated with BBB homeostasis could be involved with a higher risk of leukoaraiosis.

Strokes and their relationship with sleep and sleep disorders

INTRODUCTION

In the current population, strokes are one of the most important causes of morbidity and mortality, to which new risk factors are increasingly being attributed. Of late, there is increased interest in the relationship between sleep disorders and strokes as regards risk and prognosis.

DEVELOPMENT

This article presents the changes in sleep architecture and brain activity in stroke patients, as well as the interaction between stroke and sleep disorders, including those which may also influence the outcome and recovery from strokes. The different treatments discussed in the literature are also reviewed, as correct treatment of such sleep disorders may not only improve quality of life and reduce after-effects, but can also increase life expectancy.

CONCLUSIONS

Sleep disorders are becoming increasingly associated with stroke. In addition to being a risk factor, they can also interfere in the outcome and recovery of stroke patients. This article aims to present an exhaustive and current review on strokes and their relationship with sleep alterations and sleep disorders.

Bringing forward reperfusion with oxygenated blood perfusion beyond arterial occlusion during endovascular procedures in patients with acute ischemic stroke

BACKGROUND AND PURPOSE

High recanalization rates achieved with endovascular procedures are not always followed by the expected clinical improvement. These time-consuming procedures imply a delayed reperfusion despite the capacity of earlier intravascular microcatheter bypass to the ischemic tissue beyond the clot. We aimed to explore the safety and feasibility of MOB beyond the clot.

MATERIALS AND METHODS

We studied patients with stroke undergoing endovascular procedures. The timing of procedural steps was recorded. We then explored the safety and feasibility of repeated femoral artery MOB injections beyond the occlusion every time the clot was crossed in 17 patients. Pre- and postocclusion flow was continuously monitored with TCD.

RESULTS

We studied 60 patients (mean age, 70 ± 11 years; median NIHSS score, 20; IR, 18-21). Of them, 33 (55%) received IV-tPA before the endovascular procedure. The following arteries were occluded: the MCA (63.3%, n = 38) and the ICA (36.6%, n = 22). The TSO to arterial puncture was 193 ± 77 minutes. The occluding clot was successfully crossed with the microcatheter in 46 patients (76.6%; mean TSO, 228 ± 82 minutes). Recanalization was achieved in 44 patients (73.2%; mean TSO, 328 ± 144 minutes). Repeated MOB injections were performed in 17 patients. Patients with/without MOB presented with similar baseline characteristics. The median number of MOB injections was 2 (IR, 2-3), and the median injected blood volume was 40 mL (IR, 27.5-50). The mean time from first MOB to arterial recanalization was 136 ± 86 minutes. During MOB, a nonpulsatile flow appeared in previously nonvisible distal branches on TCD.

CONCLUSIONS

In this small series, oxygenated blood delivered through a microcatheter positioned distal to the site of occlusion was feasible and safe. Until final recanalization is achieved, MOB injections may generate intermittent reperfusion for up to 2 hours.

Selection of a Bacillus pumilus strain highly active against Ceratitis capitata (Wiedemann) larvae

Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), the Mediterranean fruit fly (medfly), is one of the most important fruit pests worldwide. The medfly is a polyphagous species that causes losses in many crops, which leads to huge economic losses. Entomopathogenic bacteria belonging to the genus Bacillus have been proven to be safe, environmentally friendly, and cost-effective tools to control pest populations. As no control method for C. capitata based on these bacteria has been developed, isolation of novel strains is needed. Here, we report the isolation of 115 bacterial strains and the results of toxicity screening with adults and larvae of C. capitata. As a result of this analysis, we obtained a novel Bacillus pumilus strain, strain 15.1, that is highly toxic to C. capitata larvae. The toxicity of this strain for C. capitata was related to the sporulation process and was observed only when cultures were incubated at low temperatures before they were used in a bioassay. The mortality rate for C. capitata larvae ranged from 68 to 94% depending on the conditions under which the culture was kept before the bioassay. Toxicity was proven to be a special characteristic of the newly isolated strain, since other B. pumilus strains did not have a toxic effect on C. capitata larvae. The results of the present study suggest that B. pumilus 15.1 could be considered a strong candidate for developing strategies for biological control of C. capitata.

Symptomatic intracerebral hemorrhage and recanalization after IV rt-PA: a multicenter study

BACKGROUND

Symptomatic intracerebral hemorrhage (sICH) is the most unfavorable complication after IV thrombolytic treatment. We aimed to determine the relationship between early recanalization and the risk of sICH.

METHODS

Patients with acute stroke received IV tissue plasminogen activator (rt-PA) within 3 hours of symptom onset with transcranial Doppler (TCD) monitoring at four academic centers. sICH was defined as parenchymal hemorrhage on CT in relation to neurologic worsening (NIH Stroke Scale [NIHSS] > or = 4) within 72 hours after treatment. Poor outcome was defined as modified Rankin Scale 3-6 at 3 months. Early recanalization was graded with Thrombolysis in Brain Ischemia (TIBI) system. Multiple logistic regression analyses were used to identify predictors of sICH.

RESULTS

A total of 349 patients received rt-PA at median 134 +/- 32 minutes (mean age 69 +/- 13 years, 186 men [53%]). Median pretreatment NIHSS score was 16 points (interquartile range: 12-20). Median time to TCD was 130 +/- 40 minutes. At the end of rt-PA infusion, 135 patients (38%) had no recanalization, 101 (29%) partial, and 113 (32%) complete recanalization. sICH occurred in 26 patients (7.4%). Of the 135 patients without early recanalization, 18 (13%) had sICH, as compared to 4 (4%) of the 109 subjects with partial recanalization and 4 (3.5%) of 113 with complete recanalization, p = 0.005. After adjustment for age, sex, baseline NIHSS score, glucose, blood pressure, and time to treatment, patients with persistent occlusion had sixfold higher risk of sICH (OR = 6, 95% CI 1.5-21.3, p = 0.01).

CONCLUSION

The risk of tPA-related symptomatic intracerebral hemorrhage (sICH) is low after early and complete restoration of blood flow. Arterial occlusion persistent beyond tissue plasminogen activator infusion emerges as an independent predictor of higher risk of sICH in patients treated with systemic thrombolysis.

Prognostic significance of blood pressure variability after thrombolysis in acute stroke

OBJECTIVE

To evaluate the impact of early blood pressure (BP) changes on diffusion-weighted imaging (DWI) lesion evolution and clinical outcome in patients with stroke treated with IV tissue plasminogen activator (tPA).

METHODS

We prospectively evaluated 80 patients with stroke with a documented middle cerebral artery occlusion treated with IV tPA. Multiple repeated systolic (SBP) and diastolic (DBP) BP measurements were obtained during 24 hours after admission. All patients underwent DWI, perfusion-weighted imaging, and magnetic resonance angiography before and 36-48 hours after thrombolysis. Recanalization was assessed on transcranial Doppler at 6 hours of stroke onset. NIH Stroke Scale scores were recorded at baseline and 24 hours. Modified Rankin Scale was used to assess 3-month outcome.

RESULTS

Recanalization occurred in 44 (55%) patients. BP variability, estimated as the SD of the mean, was associated with DWI lesion growth (r = 0.46, p = 0.0003 for SBP and r = 0.26, p = 0.02 for DBP), early clinical course (p = 0.06 for SBP and p = 0.01 for DBP), and 3-month outcome (p = 0.002 for SBP and 0.07 for DBP). However, the prognostic significance of BP changes differed depending on the presence of recanalization. SBP variability emerged as an independent predictor of DWI lesion growth (beta: 6.9; 95% CI, 3.2 to 10.7, p = 0.003) and worse stroke outcome (OR: 11; 95% CI: 2.2 to 56.1; p = 0.004) in patients without recanalization, but not in recanalized patients.

CONCLUSION

Blood pressure variability is associated with greater diffusion-weighted imaging lesion growth and worse clinical course in patients with stroke treated with IV tissue plasminogen activator. However, its impact varies depending on the occurrence of early recanalization after thrombolysis.

Simvastatin in the acute phase of ischemic stroke: a safety and efficacy pilot trial

Although statins are being used for secondary prevention of ischemic stroke, recent experimental data have shown new pleiotropic effects of these drugs responsible for their role in neuroprotection. We conducted a pilot, double-blind, randomized, multicenter clinical trial to study for the first time safety and efficacy of simvastatin in the acute phase of ischemic stroke. Simvastatin/placebo was given at 3-12 h from symptom onset to 60 patients with cortical strokes. Efficacy on the evolution of several inflammation markers [interleukin (IL)-6, IL-8, IL-10, monocyte chemoattractant protein-1, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, C-reactive protein, sApo/Fas, tumor necrosis factor-alpha, E-selectin, L-selectin and nitrites+nitrates] and neurological outcome was evaluated at baseline, day 1, 3, 5, 7 and 90. No differences were found amongst the biomarkers studied regarding treatment allocation. Although simvastatin patients improved significantly by the third day (46.4% vs. 17.9%, P = 0.022), a non-significant increase in mortality and greater proportion of infections (odds ratio 2.4, confidence interval 1.06-5.4) in the simvastatin group were the main safety concerns. Therefore, a larger clinical trial is needed to confirm the net benefit of this therapeutic approach.

Influence of thrombin-activatable fibrinolysis inhibitor and plasminogen activator inhibitor-1 gene polymorphisms on tissue-type plasminogen activator-induced recanalization in ischemic stroke patients

OBJECTIVE

Endogenous resistance to tissue-type plasminogen activator (t-PA) might decrease the benefit of thrombolysis-induced recanalization. Thrombin-activatable fibrinolysis inhibitor (TAFI) and plasminogen activator inhibitor-1 (PAI-1) are fibrinolysis inhibitors. TAFI removes residues from partially degraded fibrin that in turn eliminates plasminogen binding sites; PAI-1 directly inhibits the activity of t-PA. We aimed to study whether the presence of two common functional polymorphisms of the TAFI and PAI-1 genes influence rates of recanalization of the middle cerebral artery (MCA) among t-PA-treated stroke patients.

METHODS AND RESULTS

TAFI and PAI-1 polymorphism determinations were performed by restriction fragment length polymorphism mapping and conventional sequencing in 139 patients with strokes involving the MCA and who received t-PA within 3 h. Recanalization was diagnosed by means of transcranial Doppler. No association was found between PAI-1 4 G/5 G polymorphism and recanalization rate. Dyslipidemia and TAFI Thr325Ile polymorphism were the main variables associated with recanalization resistance by the end of t-PA infusion: odds ratio (OR) 4.1 [95% confidence interval (95% CI) 1.6-10.8, P = 0.003] and OR 5.6 (95% CI 1.2-20, P = 0.031), respectively. The combination of the two polymorphisms doubled the risk of absence of recanalization: OR 11.1 (95% CI 1.4-89.8, P = 0.025).

CONCLUSIONS

Polymorphic fibrinolysis inhibitor genes influence t-PA-induced recanalization resistance in ischemic stroke patients, especially when coexisting in the same patient. Efforts to individualize thrombolytic treatments are required.

Prognostic value of myocardial perfusion gated SPECT in patients with symptomatic intracranial large-artery atherosclerosis

BACKGROUND

We aimed to evaluate the prognostic value of myocardial perfusion gated SPECT in patients with symptomatic intracranial large-artery atherosclerosis (ILA).

METHODS

Seventy-two consecutive first-ever symptomatic ILA patients without known heart disease underwent a stress myocardial perfusion gated SPECT, and long-term follow-up was conducted thereafter.

RESULTS

During an average follow-up of 15.2 +/- 9 months, 9 patients (13.8%) presented major coronary events (CEs). Survival analyses (Kaplan-Meier and Cox regression) identified presence of moderate-to-severe myocardial perfusion defects (log rank p = 0.004) and ejection fraction <50% (p = 0.014) as predictors of future CEs. Neurovascular ischemic events were not predicted by SPECT variables.

CONCLUSION

Myocardial perfusion scintigraphy predicts future CEs in patients with symptomatic ILA and may be helpful to guide therapeutic strategies in this subgroup of stroke patients.

C-reactive protein predicts further ischemic events in transient ischemic attack patients

BACKGROUND AND PURPOSE

Although patients with transient ischemic attack (TIA) experience cardiovascular events frequently, strong clinical predictors of recurrence are lacking. High-sensitivity C-reactive protein (hs-CRP) has been shown to be a powerful predictor of future first-ever and recurrent coronary and cerebral ischemic events. We aimed to investigate the relationship between hs-CRP and the risk of further ischemic events in TIA patients.

METHODS

High-sensitivity C-reactive protein level was determined <24 h after symptom onset among 135 consecutive TIA patients and stroke recurrence or any new vascular event was recorded during 1 year follow-up period.

RESULTS

A total of 38 (28.1%) patients experienced an end point event: 28 (20.7%) cerebral ischemic events, six (4.4%) heart ischemic events, four (3%) peripheral arterial disease, and nine (6.7%) vascular deaths. Cox proportional hazards multivariate analyses identified age [hazard ratio (HR) 1.07, 95% confidence interval (CI) 1.01-1.12, P = 0.01], large-artery occlusive disease (HR 2.73, 95% CI 1.16 to 6.41, P = 0.02) and hs-CRP> 4.1 mg/l (HR 2.81, 95% CI 1.12-7.10, P = 0.03) as independent predictors of stroke. Moreover, age (HR 1.05, 95% CI 1.01-1.10, P = 0.02), large-artery occlusive disease (HR 3.12, 95% CI 1.48-6.58, P < 0.01), coronary disease (HR 2.39, 95% CI 1.11-5.16, P = 0.03), and hs-CRP> 4.1 mg/l (HR 2.71, 95% CI 1.16-6.30, P = 0.02) were also independent predictors of any vascular event.

CONCLUSIONS

High-sensitivity C-reactive protein serum level predicts further ischemic events following TIA. Routine CRP measurement might be a useful tool for identifying high-risk TIA patients in order to plan aggressive diagnostic protocols and prevention therapies.

Outcome in hyperglycemic stroke with ultrasound-augmented thrombolytic therapy

Hyperglycemia independently predicts poor outcome after acute ischemic stroke. CLOTBUST (Combined Lysis Of Thrombus in Brain ischemia using transcranial Ultrasound and Systemic tPA) demonstrated that ultrasound-augmented thrombolysis improves recanalization and 24-hour outcome in patients with acute ischemic stroke. We hypothesized that ultrasound would preferentially benefit hyperglycemic patients, and reviewed CLOTBUST with respect to admission glucose and good outcome. We found that ultrasound's benefit on 90-day outcome was primarily apparent at higher glucose levels, suggesting that ultrasound therapy may improve outcome following hyperglycemic stroke.

Plasma d-dimer predicts poor outcome after acute intracerebral hemorrhage

OBJECTIVE

To investigate if systemic d-dimer activation occurs after acute intracerebral hemorrhage (ICH) and to study its influence on clinical outcome.

METHODS

The authors determined plasma baseline d-dimer in 98 consecutive acute (<24 hours) ICH patients. Glasgow Coma Scale and NIH Stroke Scale scores were recorded to assess neurologic status on baseline and follow-up visits (24 hours, 48 hours, 7th day, and 3rd month). They also determined the d-dimer temporal profile at follow-up visits in a subgroup of 21 patients. ICH volume was measured on baseline and follow-up CT scans. Early neurologic deterioration (END) and mortality during the 1st week were recorded.

RESULTS

ICH patients showed higher plasma d-dimer level than reference laboratory values at baseline (1,780 vs 360 ng/mL; p = 0.013) and 3 months after ICH onset (1,530 vs 470 ng/mL; p = 0.013). The d-dimer level was related to baseline ICH volume (r = 0.23, p = 0.049) and to the presence of intraventricular (2,370 vs 1,360 ng/mL; p = 0.019) or subarachnoid (4,180 vs 1,520 ng/mL; p = 0.001) extension. Nearly one-fourth of patients presented END, and 20% died as a result of ICH. As predictors of END, the authors identified d-dimer level >1,900 ng/mL (odds ratio [OR] 4.5, 95% CI 1.03 to 20.26, p = 0.045) and systolic blood pressure >182 mm Hg (OR 6.8, 95% CI 1.25 to 36.9, p = 0.026). Moreover, ICH volume >30 mL (OR 19.13, 95% CI 2.06 to 177, p = 0.009) and d-dimer levels >1,900 ng/mL (OR 8.75, 95% CI 1.41 to 54.16, p = 0.020) emerged as independent predictors of mortality.

CONCLUSION

Increased plasma d-dimer level following acute intracerebral hemorrhage is associated with early neurologic deterioration and poor outcome.

[ApoE genotype influences on efficacy and safety of thrombolytic treatment for ischemic stroke]

INTRODUCTION

Apolipoprotein E has been associated with intracerebral hemorrhages and with neurological outcome of ischemic stroke patients treated with rt-PA. Therefore, we hypothesized that ApoE genotype might influence the appearance of post-tPA hemorrhagic transformation and that the favorable outcome of E2 patients might be due to better rates of recanalization.

PATIENTS AND METHODS

We analyzed the ApoE genotype of 77 patients with ischemic stroke involving the territory of the middle cerebral artery who received rt- PA within 3 h of symptoms onset. The hemorrhagic events were evaluated by computed tomography and the arterial recanalization by transcraneal doppler.

RESULTS

We did not observe any association between ApoE genotypes and the rates of hemorrhagic transformation following rt-PA treatment (E2 = 33.3 %, E3 = 32.7%, E4=11.8%; p=0.241). Rates of artery recanalization following thrombolysis were similar regarding ApoE genotypes at 1 hour post-tPA administration (E2=40%, E3+E4=45.9%; p=0.799), at 6 hours post-tPA (E2=80%, E3+E4=62.3 %; p=0.43) or at 24 hours post-tPA (E2= 100%, E3+E4=75%, p=0.203). No association was observed between ApoE genotypes and NIHSS scores at 48 hours (E2=8, E3+E4=12; p=0.811) nor with the modified ranking scale at 3 months (E2=1.5, E3+E4=4; p=0.350).

CONCLUSIONS

In our group of stroke patients, ApoE genotypes are not related with the presence of hemorrhagic transformations neither with the rates of recanalization following thrombolytic treatment.

Outcome in patients with basilar artery occlusion treated conventionally

BACKGROUND

Most data on the outcome of basilar artery occlusion are from recent case series of patients treated with intra-arterial thrombolysis. The limited knowledge on the outcome after a conventional treatment approach comes from a few small case series of highly selected patients.

OBJECTIVE

To provide more data on the outcome of conventional treatment.

METHODS

Data were analysed on patients from three centres with symptomatic basilar artery occlusion treated conventionally. Conventional therapy was defined as treatment with antiplatelets, anticoagulation, or both.

RESULTS

Data were available on 82 patients. The case fatality was 40%. Among survivors, 65% remained dependent (Rankin score 4-5). Patients younger than 60 years (odds ratio = 3.1 (95% confidence interval, 1.0 to 9.5)) and those with a minor stroke (OR = 3.1 (1.0 to 9.6)) were more likely to have a good outcome (Rankin score 0-3). Patients with a progressive stroke were less likely to have a good outcome (OR = 0.3 (0.08 to 1.2)) than patients with a maximum deficit at onset or fluctuating symptoms at presentation.

CONCLUSIONS

Conventional treatment of symptomatic basilar artery occlusion is associated with a poor outcome in almost 80% of patients, which emphasises the importance of the search for a more effective treatment approach.

High lipoprotein (a), diabetes, and the extent of symptomatic intracranial atherosclerosis

BACKGROUND

Lipoprotein (a) (Lp[a]) has important atherothrombogenic properties, but its role in intracranial atherosclerosis remains unclear.

OBJECTIVE

To investigate the relationship between Lp(a) level and the extent of intracranial large-artery occlusive disease.

METHODS

Between June 2001 and August 2003, 166 consecutive first-ever TIA or stroke patients had intracranial stenoses on transcranial Doppler, of which 100 fulfilled all inclusion criteria. The extent of intracranial large-artery occlusive disease was assessed by the number of angiographically confirmed intracranial stenoses. Serum Lp(a) was determined a minimum of 3 months after stroke onset.

RESULTS

Two hundred eighty-one intracranial stenoses were documented. Fifty-one (51%) patients had three or more stenoses (greater-extent group). Patients in the highest Lp(a) quartile had a higher adjusted odds ratio (OR) for a greater extent than those in the lowest quartile (OR 3.43, 95% CI 1.04 to 11.33, p = 0.04). A positive correlation was found between Lp(a) concentration and the number of stenoses (r = 0.310, p = 0.002). Moreover, Lp(a) level increased gradually with the number of stenoses (p = 0.02). A multiple logistic regression model identified diabetes (OR 2.4, 95% CI 1.04 to 5.57, p = 0.04) and high Lp(a) (OR 2.52, 95% CI 1.03 to 6.18, p = 0.043) as independent markers of a greater extent of intracranial large-artery occlusive disease.

CONCLUSIONS

High Lp(a) level and diabetes mellitus are independent markers of a greater extent of intracranial large-artery occlusive disease. These findings support a role for Lp(a) in intracranial stenotic atherogenesis and might be useful for the selection of high-risk patients.

Gabapentin in late-onset poststroke seizures

Stroke is a frequent cause of epileptic seizures (ES) in adults. The authors evaluated the long-term efficacy and tolerability of gabapentin (900 to 1,800 mg/day) in 71 patients with a first poststroke late ES during a mean follow-up time of 30 months. ES recurred in 18.3% of the patients and side effects were noted in 27 cases (38%), but only two (2.8%) required discontinuation or early withdrawal. Gabapentin monotherapy was useful and safe for late poststroke ES.

Matrix metalloproteinase expression is related to hemorrhagic transformation after cardioembolic stroke

BACKGROUND AND PURPOSE

In animal models of cerebral ischemia, matrix metalloproteinase (MMP) expression was significantly increased and related to blood-brain barrier disruption, edema formation, and hemorrhagic transformation (HT). MMP inhibitors reduce HT after embolic ischemia in tissue-type plasminogen activator-treated animals. We aimed to determine the relationship between MMPs and HT after human ischemic stroke.

METHODS

Serial MMP-2 and MMP-9 determinations were performed by means of ELISA in 39 cardioembolic strokes in the middle cerebral artery territory. Hemorrhagic events were classified according to clinical and CT criteria (hemorrhagic infarction [HI] and parenchymal hematoma [PH]). HT was evaluated on CT at 48 hours (early HT) and again between day 5 and 7 (late HT).

RESULTS

HT was present in 41% of the patients (43.75% early HI, 25% early PH and 31.25% late HI). MMP-2 values were within normal range and were unrelated to HT. Increased expression of MMP-9 (normal range <97 ng/mL) was found among patients with and without HT (159.3+/-82 versus 143.9+/-112.6 ng/mL; P=0.64). According to HT subtypes, the highest baseline MMP-9 levels corresponded to patients with late HI (240.4+/-111.2 versus 102.5+/-76.7 ng/mL for all other patients, P=0.002). Baseline MMP-9 was the only variable associated with late HI in the multiple logistic regression model (OR 9; CI 1.46, 55.24; P=0.010). Peak of MMP-9 at the 24-hour time point (250.6 ng/mL) was found before appearance of PH.

CONCLUSIONS

MMPs are involved in some subtypes of HT after human cardioembolic stroke. Baseline MMP-9 level predicts late HI and a 24-hour peak precedes early PH.

Time course of tissue plasminogen activator-induced recanalization in acute cardioembolic stroke: a case-control study

BACKGROUND AND PURPOSE

The relationship between arterial recanalization, infarct size, and outcome in patients treated with intravenous thrombolytics remains unclear. Therefore, we aimed to determine the time course of recombinant tissue plasminogen activator (rtPA)-induced recanalization in patients with cardioembolic stroke treated <3 hours from symptom onset and to investigate the relationship between arterial recanalization, infarct volume, and outcome.

METHODS

We prospectively studied 72 patients with an acute cardioembolic stroke in the middle cerebral artery territory: 24 treated with rtPA at <3 hours and 48 matched controls. Serial transcranial Doppler examinations were performed on admission and at 6,12, 24, and 48 hours. Infarct volume was measured by use of CT at day 5 to 7. Modified Rankin Scale score was used to assess outcome at 3 months.

RESULTS

Rate of 6-hour recanalization was higher (P<0.001) in the rtPA group (66%) than in the control group (15%). Five (20.8%) rtPA patients and 15 (31.2%) controls recanalized between 6 and 12 hours, and 2 (8.3%) patients and 12 (25%) controls between 12 and 48 hours, respectively. At 48 hours, 75% of rtPA patients and 27% of controls had improved (P<0.001). Infarct volume was 50.2+/-40.3 cm(3) in rtPA patients and 124.8+/-81.6 cm(3) in controls (P<0.001). Moreover, infarct volume was associated strongly (P<0.001) with duration of middle cerebral artery occlusion. At 3 months, 14 (58%) rtPA patients and 11 (23%) controls (P=0.037) became functionally independent (modified Rankin Scale score </=2). A close relationship (P=0.002) existed between modified Rankin Scale score at 3 months and time to reperfusion. In addition, clinical outcome was associated strongly (P=0.001) with degree of 6-hour recanalization. Logistic regression analysis identified National Institutes of Health Stroke Scale score <17 (odds ratio 12.1, 95% confidence interval 2.8 to 68, P=0.001) and early recanalization (odds ratio 23.4, 95% confidence interval 5.4 to 96, P=0.001) as independent predictors of functional independence at 3 months.

CONCLUSIONS

Intravenous rtPA is associated with early recanalization, which leads to lower infarct size and better clinical outcome. Early recanalization is a powerful independent predictor of functional independence at 3 months.

Progression and clinical recurrence of symptomatic middle cerebral artery stenosis: a long-term follow-up transcranial Doppler ultrasound study

BACKGROUND AND PURPOSE

Patients with symptomatic intracranial atherosclerotic stenosis have a high rate of recurrence. We conducted a prospective study to determine which factors are associated with the progression of symptomatic middle cerebral artery (MCA) stenosis and to evaluate the relationship between progression and clinical recurrence.

METHODS

Between January 1996 and February 2000, of a total of 2564 consecutive first-ever transient ischemic attack (TIA) or stroke patients admitted to our cerebrovascular unit, 145 showed an MCA stenosis signal on transcranial Doppler (TCD) on admission, and 40 fulfilled all criteria to enter this study, including angiographic confirmation. Patients were prescribed antiplatelet or anticoagulant agents following the criteria of the neurologist in charge. TCD recordings and clinical interviews were performed regularly during follow-up. Progression of MCA stenosis was defined as an increase >30 cm/s in TCD-recorded maximum mean flow velocity. Logistic regression analyses were used to identify predictors of progression and clinical recurrence.

RESULTS

With a median follow-up of 26.55 months, 13 (32.5%) MCA stenoses progressed, 3 (7.5%) regressed, and 24 (60%) remained stable. Absence of significant extracranial internal carotid artery (ICA) stenosis (P=0.049) and the use of oral anticoagulants (P=0.045) were significantly associated with a lower progression rate in univariate analysis, and anticoagulation remained an independent predictor when a logistic regression model was applied (OR 7.25, CI 1.1 to 48.1, P=0.019). A new ischemic event during follow-up in the territory supplied by the stenosed MCA occurred in 8 cases (20%), and 13 patients had a major vascular event. Progression of the MCA stenosis detected by TCD was independently associated with a new ipsilateral ischemic event (OR 2.89, CI 1.09 to 7.71, P=0.031) and with the occurrence of any major vascular event (OR 7.03, CI 1.6 to 30.9, P=0.0071).

CONCLUSIONS

Progression of symptomatic MCA stenosis detected by means of TCD predicts clinical recurrence. Anticoagulation is independently associated with a lower progression rate of symptomatic MCA stenosis.

Mitogen-activated protein kinase phosphorylates and targets inducible cAMP early repressor to ubiquitin-mediated destruction

Inducible cAMP early repressor (ICER) is an important mediator of cAMP antiproliferative activity that acts as a putative tumor suppressor gene product. In this study, we examined the regulation of ICER protein by phosphorylation and ubiquitination in human choriocarcinoma JEG-3 and mouse pituitary AtT20 cells. We found that cAMP stabilized ICER protein by inhibiting the mitogen-activated protein kinase (MAPK) cascade. Activation of the MAPK pathway increased ICER phosphorylation. ICER phosphorylation was abrogated by inhibition of the MAPK pathway either by cAMP or directly by the MAPK inhibitor PD098059. The MAPKs extracellular signal-regulated kinases 1 and 2 physically interact with ICER and mediated the phosphorylation of ICER on a critical serine residue (Ser-41). A mutant form of ICER in which Ser-41 was substituted by alanine had a half-life 4-5 h longer than its wild-type counterpart. This alteration in stability was due to the inability of the Ser-41-mutant ICER to be efficiently ubiquitinated and degraded via the ubiquitin-proteasome pathway. These results present a novel cell signaling cross-talk mechanism at the cell nucleus between the MAPK and cAMP pathways, whereby MAPK targets a repressor of the cAMP-dependent gene expression for ubiquitination and proteasomal degradation.

The expression of inducible cAMP early repressor (ICER) is altered in prostate cancer cells and reverses the transformed phenotype of the LNCaP prostate tumor cell line

Inducible cAMP early repressor (ICER) has been shown to be an important mediator of cAMP antiproliferative activity. In this report, it was found that cAMP retards LNCaP cell growth; in contrast, cAMP inhibits the growth of PC-3 and DU-145 cells. ICER protein levels were markedly reduced in prostate cancer epithelial cells and undetectable and uninducible by cAMP in LNCaP and DU 145 cells. Forced expression of ICER in LNCaP cells caused inhibition of cell growth and thymidine incorporation and halted cells at the G(1) phase of the cell cycle. These ICER-bearing LNCaP cells were rendered unable to grow in soft agar and unable to form tumors in nude mice. These results suggest that deregulation of ICER expression may be related to carcinogenesis of the prostate gland.

Timing of spontaneous recanalization and risk of hemorrhagic transformation in acute cardioembolic stroke

BACKGROUND AND PURPOSE

The relationship between reperfusion and hemorrhagic transformation (HT) remains uncertain. Therefore, we aimed to clarify the relationship between the time course of recanalization and the risk of HT in patients with cardioembolic stroke studied within 6 hours of symptom onset.

METHODS

Fifty-three patients with atrial fibrillation and nonlacunar stroke in the middle cerebral artery (MCA) territory admitted within the first 6 hours after symptom onset were prospectively studied. Serial TCD examinations were performed on admission and at 6, 12, 24, and 48 hours. CT was performed within 6 hours after stroke onset and again at 36 to 48 hours.

RESULTS

Proximal and distal MCA occlusions were detected in 32 patients (60.4%) and 18 patients (34%), respectively. Early spontaneous recanalization occurring within 6 hours was identified in 10 patients (18.8%). Delayed recanalization (>6 hours) occurred in 28 patients (52.8%). HT on CT scan was detected in 17 patients (32%) within the first 48 hours. Only large parenchymal hemorrhage (PH2) was significantly associated with an increase (P=0.038, Kruskal-Wallis test) in the National Institutes of Health Stroke Scale (NIHSS) score compared with the other subtypes of HT. Univariate analysis revealed that an NIHSS score of >14 on baseline (P=0.001), proximal MCA occlusion (P=0.004), hypodensity >33% of the MCA territory (P=0.012), and delayed recanalization occurring >6 hours of stroke onset (P=0.003) were significantly associated with HT. With a multiple logistic regression model, delayed recanalization (OR 8.9; 95% CI 2.1 to 33.3) emerged as independent predictor of HT.

CONCLUSIONS

Delayed recanalization occurring >6 hours after acute cardioembolic stroke is an independent predictor of HT.

Cerebral microembolism in acute spontaneous internal carotid artery dissection

The rate and risk factors for early ischemic recurrence in patients with internal carotid artery dissection (ICAD) are largely unknown. Serial transcranial Doppler (TCD) monitoring of microembolic signals (MES) was performed in 28 consecutive patients with acute ICAD. MES were identified in 13 patients, and early ischemic recurrence occurred in 7. Six of 13 patients with MES and 1 of 15 without MES experienced early ischemic recurrence (p = 0.029). MES detection on serial TCD monitoring may be associated with an increased risk of early ischemic recurrence in patients with acute ICAD.

Inducible cyclic AMP early repressor protein in rat pinealocytes: a highly sensitive natural reporter for regulated gene transcription

Rhythmic activity of arylalkylamine N-acetyltransferase (AANAT) determines melatonin synthesis in rat pineal gland. The transcriptional regulation of AANAT involves the activating and inhibiting transcription factors of the cyclic AMP (cAMP)-signaling pathway, cAMP response element-binding protein and inducible cAMP early repressor (ICER), respectively. Activation of this pathway is centered around norepinephrine, stimulating beta(1)-adrenergic receptors, but various other transmitters can modulate melatonin biosynthesis. To compare the transcriptional impact of norepinephrine with that of other neurotransmitters on melatonin synthesis, we determined ICER protein levels in pinealocytes and, in parallel, hormone secretion. The dose-dependent inductions of ICER protein by norepinephrine, the beta(1)-adrenergic receptor agonist isoproterenol, vasoactive intestinal peptide, pituitary adenylate cyclase-activating polypeptide, and adenosine are correlated to regulatory dynamics in melatonin production. Importantly, ICER protein induction required lower ligand concentrations than the induction of melatonin biosynthesis. Although neuropeptide Y, glutamate, and vasopressin altered norepinephrine-stimulated hormone production without affecting ICER levels, the activation of voltage-gated cation channels increased ICER without affecting hormone synthesis. Sensitivity and versatility of ICER induction in pinealocytes make these neuroendocrine cells a valuable model system in which to study molecular interactions determining a regulated gene expression.

Transcription factors in neuroendocrine regulation: rhythmic changes in pCREB and ICER levels frame melatonin synthesis

Neurotransmitter-driven activation of transcription factors is important for control of neuronal and neuroendocrine functions. We show with an in vivo approach that the norepinephrine cAMP-dependent rhythmic hormone production in rat pineal gland is accompanied by a temporally regulated switch in the ratio of a transcriptional activator, phosphorylated cAMP-responsive element-binding protein (pCREB), and a transcriptional inhibitor, inducible cAMP early repressor (ICER). pCREB accumulates endogenously at the beginning of the dark period and declines during the second half of the night. Concomitant with this decline, the amount of ICER rises. The changing ratio between pCREB and ICER shapes the in vivo dynamics in mRNA and, thus, protein levels of arylalkylamine-N-acetyltransferase, the rate-limiting enzyme of melatonin synthesis. Consequently, a silenced ICER expression in pinealocytes leads to a disinhibited arylalkylamine-N-acetyltransferase transcription and a primarily enhanced melatonin synthesis.

ICER-IIgamma is a tumor suppressor that mediates the antiproliferative activity of cAMP

The second messenger cAMP inhibits the proliferation of most cell types. The nuclear response of cAMP is mediated by transcription factors like the cAMP-Responsive Element Modulator (CREM) gene. One of the products of the CREM gene, the transcriptional repressor Inducible cAMP Early Repressor-IIgamma (ICER-IIgamma), is induced by cAMP. ICER-IIgamma blocks cells at the G2/M boundary of the cell cycle. Here we show that ICER-IIgamma dramatically inhibits the growth and DNA synthesis of mouse pituitary tumor cells and human choriocarcinoma cells. This alteration in cell growth is coupled with reduced ability of these cells to grow in an anchorage-independent manner and to form tumors in mice. These data demonstrate that ICER-IIgamma is a tumor suppressor gene product mediating the antiproliferative activity of cAMP.

Expression of DA11, a neuronal-injury-induced fatty acid binding protein, coincides with axon growth and neuronal differentiation during central nervous system development

DA11 is the first fatty acid binding protein (FABP) for which gene expression has been shown to be upregulated following neuronal injury in the adult peripheral nervous system. To understand better the potential regulatory role(s) of this unique FABP in axonal growth and neuronal differentiation, we undertook a temporal and spatial study of DA11 gene expression in the developing rat central nervous system (CNS). Transient upregulation of DA11 mRNA and protein levels in CNS tissues were quantified by Northern blot hybridization and Western immunoblot analyses at different developmental ages. Homogenates of embryonic and neonatal cerebral cortex, cerebellum, brain stem, and hippocampal tissues contained 100-fold more DA11 mRNA and protein than corresponding adult tissues. Significant increase in DA11 mRNA was observed as early as embryonic day (E) 14 in cerebral cortex and cerebellum and E19 in brain stem and hippocampus. Postnatal levels of DA11 remained elevated through postnatal day (P) 10 in cerebral cortex, P14 in brain stem and hippocampus, and P20 in cerebellum. Localization of DA11-like immunoreactivity to specific CNS tissues, cell types, and intracellular compartments at P9 revealed a spatial pattern of neuronal expression different than that reported for other FABPs. DA11 protein was detected in the nucleus, cytoplasm, axons, and dendrites of differentiating neurons in cerebral cortex, hippocampus, cerebellum, brain stem, spinal cord, and olfactory bulb. The strong association of DA11 gene expression with development throughout the CNS suggests that this unique FABP plays an important role in axonal growth and neuronal differentiation in many different neuronal populations.

Fatty acid binding protein is induced in neurons of the dorsal root ganglia after peripheral nerve injury

Peripheral nerve trauma induces the expression of genes presumed to be involved in the process of nerve degeneration and repair. In the present study, an in vivo paradigm was employed to identify molecules which may have important roles in these processes. A cDNA library was constructed with RNA extracted from rat dorsal root ganglia (DRG) 3 days after a sciatic nerve crush. After differential hybridization to this library, several cDNAs were identified that encoded mRNAs that were upregulated in the DRG ipsilateral to the crush injury, as opposed to the contralateral or naive DRG. Approximately 0.15% of all the clones screened were found to be induced. This report presents the types of induced sequences identified and characterizes one of them, DA11. The 0.7 kb DA11 full length cDNA clone contains a 405 nucleotide open reading frame that encodes a putative protein of 15.2 kDa (135 amino acid residues) and is a member of the family of fatty acid binding proteins (FABP). The DA11 protein differs by one amino acid residue from the sequence of the C-FAPB protein and by eight residues from the sequence of mal1, proteins found in rat and mouse skin, respectively. Northern and Western blot analyses showed that the DA11 mRNA and protein were induced in the injured DRG. Furthermore, studies using antibodies generated against DA11 found that the DA11-like immunoreactivity was more pronounced in the nuclei of neurons located in the DRG ipsilateral to the sciatic cut than those located in the contralateral DRG. The induction of DA11 mRNA and protein in DRG neurons suggests, for the first time, the involvement of a neuronal FABP in the process of degeneration and repair in the nervous system.