Predictive Clinical Factors of In-Hospital Mortality in Women Aged 85 Years or More with Acute Ischemic Stroke

INTRODUCTION

There are limited data on the outcome of acute ischemic stroke oldest old women. We assessed clinical risk factors for in-hospital mortality in women aged 85 years or more with acute ischemic stroke.

METHODS

This single-center retrospective cohort study included 506 women aged ≥ 85 years collected from a total of 4,600 patients with acute cerebral infarction registered in an ongoing 24-year hospital stroke database. The identification of clinical risk factors for in-hospital mortality was the primary endpoint of the study.

RESULTS

The mean (± standard deviation) age of the patients was 88.6 ± 3.2 years. Stroke subtypes were cardioembolic infarcts in 37.7% of patients, atherothrombotic infarcts in 30.8%, infarcts of unknown cause and lacunar infarcts in 26.1% each, and infarcts of unusual cause in 11.5%. The in-hospital mortality rate was 20.4% (n = 103). Cardioembolic infarct accounted for 67% of all deaths (n = 69). Sudden stroke onset (OR 1.87, 95% CI 1.14-3.06), altered consciousness (OR 7.05, 95% CI 4.36-11.38) and neurological, cardiac, respiratory, and hemorrhagic events during hospitalization were independent risk factors for death, whereas lacunar infarction was a protective factor (OR 0.10, 95% CI 0.01-0.82).

CONCLUSION

The oldest old age segment of women with acute ischemic infarction is a subgroup of stroke patients with unfavorable prognosis and high in-hospital mortality associated with sudden stroke onset, altered consciousness and medical complications developed during hospitalization. Lacunar infarction as stroke subtype showed a favourable prognosis.

Biochemical precursor effects on the fatty acid production in cell suspension cultures of Theobroma cacao L

Cocoa butter (CB) is composed of 96% palmitic, stearic, oleic, linoleic and linolenic fatty acids that are responsible for the hardness, texture and fusion properties of chocolate. Through in vitro plant cell culture it is possible to modify CB lipid profiles and to study the fatty acid biosynthesis pathway on a subcellular level, evaluating fundamental aspects to enhance in vitro fatty acid production in a specific and controlled way. In this research, culture media was supplemented with acetate, biotin, pyruvate, bicarbonate and glycerol at three different concentrations and the effects on the biomass production (g/L), cell viability, and fatty acids profile and production was evaluated in in vitro cell suspensions culture. It was found that biotin stimulated fatty acid synthesis without altering cell viability and cell growth. It was also evident a change in the lipid profile of cell suspensions, increasing middle and long chain fatty acids proportion, which are unusual to those reported in seeds; thus implying that it is possible to modify lipid profiles according to the treatment used. According to the results of sucrose gradients and enzyme assays performed, it is proposed that cacao cells probably use the pentose phosphate pathway, mitochondria being the key organelle in the carbon flux for the synthesis of reductant power and fatty acid precursors.

Stroke and sleep-disordered breathing: A relationship under construction

The association between sleep-disordered breathing (SDB) and cardiovascular risk has been the focus of attention in recent years. Sleep disorders are emerging risk factors for cardiovascular disease and have been related to the whole spectrum of stroke, including transient ischemic attack, ischemic cerebral infarction and intracerebral haemorrhage. It has been shown that lacunar stroke or lacunar infarctions affecting the internal capsule or the protuberance are associated with a higher frequency of SDB. Acute stroke patients with associated SDB have a worse prognosis and a higher mortality as compared to patients with first-ever stroke without SDB. Preliminary studies provide evidence of the usefulness of treatment with continuous positive airway pressure when SDB is present in stroke patients.

A Bayesian cost-effectiveness analysis of a telemedicine-based strategy for the management of sleep apnoea: a multicentre randomised controlled trial

BACKGROUND

Compliance with continuous positive airway pressure (CPAP) therapy is essential in patients with obstructive sleep apnoea (OSA), but adequate control is not always possible. This is clinically important because CPAP can reverse the morbidity and mortality associated with OSA. Telemedicine, with support provided via a web platform and video conferences, could represent a cost-effective alternative to standard care management.

AIM

To assess the telemedicine impact on treatment compliance, cost-effectiveness and improvement in quality of life (QoL) when compared with traditional face-to-face follow-up.

METHODS

A randomised controlled trial was performed to compare a telemedicine-based CPAP follow-up strategy with standard face-to-face management. Consecutive OSA patients requiring CPAP treatment, with sufficient internet skills and who agreed to participate, were enrolled. They were followed-up at 1, 3 and 6 months and answered surveys about sleep, CPAP side effects and lifestyle. We compared CPAP compliance, cost-effectiveness and QoL between the beginning and the end of the study. A Bayesian cost-effectiveness analysis with non-informative priors was performed.

RESULTS

We randomised 139 patients. At 6 months, we found similar levels of CPAP compliance, and improved daytime sleepiness, QoL, side effects and degree of satisfaction in both groups. Despite requiring more visits, the telemedicine group was more cost-effective: costs were lower and differences in effectiveness were not relevant.

CONCLUSIONS

A telemedicine-based strategy for the follow-up of CPAP treatment in patients with OSA was as effective as standard hospital-based care in terms of CPAP compliance and symptom improvement, with comparable side effects and satisfaction rates. The telemedicine-based strategy had lower total costs due to savings on transport and less lost productivity (indirect costs).

TRIAL REGISTER NUMBER

NCT01716676.

Professions and Working Conditions Associated With Community-Acquired Pneumonia

INTRODUCTION

Community-acquired pneumonia (CAP) is not considered a professional disease, and the effect of different occupations and working conditions on susceptibility to CAP is unknown. The aim of this study is to determine whether different jobs and certain working conditions are risk factors for CAP.

METHODOLOGY

Over a 1-year period, all radiologically confirmed cases of CAP (n=1,336) and age- and sex-matched controls (n=1,326) were enrolled in a population-based case-control study. A questionnaire on CAP risk factors, including work-related questions, was administered to all participants during an in-person interview.

RESULTS

The bivariate analysis showed that office work is a protective factor against CAP, while building work, contact with dust and sudden changes of temperature in the workplace were risk factors for CAP. The occupational factor disappeared when the multivariate analysis was adjusted for working conditions. Contact with dust (previous month) and sudden changes of temperature (previous 3 months) were risk factors for CAP, irrespective of the number of years spent working in these conditions, suggesting reversibility.

CONCLUSION

Some recent working conditions such as exposure to dust and sudden changes of temperature in the workplace are risk factors for CAP. Both factors are reversible and preventable.

Gender differences and woman-specific trends in acute stroke: results from a hospital-based registry (1986-2009)

OBJECTIVE

We assessed gender differences and women-specific secular trends in stroke.

METHODS

Data from 2318 women and 2274 men with first-ever stroke collected from the Sagrat Cor Hospital Stroke Registry of Barcelona between 1986 and 2009 were analyzed.

RESULTS

Patient's age increased significantly from a mean of 74.5 years in 1986-1992 to 81.2 years in 2004-2009 (P < 0.001). Patients aged ≥ 85 years increased from 18.5% to 38.5% (P = 0.0001) as were patients with hypertension, atrial fibrillation, and cardioembolic stroke. The in-hospital death decreased from 17.6% to 11% (P = 0.02), median length of hospital from 14 to 9 days (P = 0.0001) and prolonged hospital stay (> 12 days) from 59.7% to 33.7% (P = 0.0001). Lacunar infarction was more frequent in men (21.5% vs. 16.2%, P = 0.0003) and cardioembolic infarction in women (26% vs. 15.6%, P = 0.0001). Acute stroke in women continues to be a severe disease with high risk of death in the immediate post-stroke phase (13.5%) and low probability of early full neurological recovery (13.9% vs. 11.8%, P = 0.029).

CONCLUSION

Women differ from men in the distribution of risk factors and stroke subtype, stroke severity, and outcome. An increase in the patient's age, hypertension, atrial fibrillation and cardioembolic infarction, as well as a decrease mortality and length of hospitalization over a 24-year period was recorded.

Management of sleep apnea without high pretest probability or with comorbidities by three nights of portable sleep monitoring

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) diagnosis using simplified methods such as portable sleep monitoring (PM) is only recommended in patients with a high pretest probability. The aim is to determine the diagnostic efficacy, consequent therapeutic decision-making, and costs of OSA diagnosis using polysomnography (PSG) versus three consecutive studies of PM in patients with mild to moderate suspicion of sleep apnea or with comorbidity that can mask OSA symptoms.

DESIGN AND SETTING

Randomized, blinded, crossover study of 3 nights of PM (3N-PM) versus PSG. The diagnostic efficacy was evaluated with receiver operating characteristic (ROC) curves. Therapeutic decisions to assess concordance between the two different approaches were performed by sleep physicians and respiratory physicians (staff and residents) using agreement level and kappa coefficient. The costs of each diagnostic strategy were considered.

PATIENTS AND RESULTS

Fifty-six patients were selected. Epworth Sleepiness Scale was 10.1 (5.3) points. Bland-Altman plot for apnea-hypopnea index (AHI) showed good agreement. ROC curves showed the best area under the curve in patients with PSG AHI ≥ 5 [0.955 (confidence interval = 0.862-0.993)]. For a PSG AHI ≥ 5, a PM AHI of 5 would effectively exclude and confirm OSA diagnosis. For a PSG AHI ≥ 15, a PM AHI ≥ 22 would confirm and PM AHI < 7 would exclude OSA. The best agreement of therapeutic decisions was achieved by the sleep medicine specialists (81.8%). The best cost-diagnostic efficacy was obtained by the 3N-PM.

CONCLUSIONS

Three consecutive nights of portable monitoring at home evaluated by a qualified sleep specialist is useful for the management of patients without high pretest probability of obstructive sleep apnea or with comorbidities.

CLINICAL TRIAL REGISTRATION

http://www.clinicaltrials.gov, registration number: NCT01820156.

CITATION

Guerrero A, Embid C, Isetta V, Farre R, Duran-Cantolla J, Parra O, Barbé F, Montserrat JM, Masa JF. Management of sleep apnea without high pretest probability or with comorbidities by three nights of portable sleep monitoring.

Efficacy of continuous positive airway pressure treatment on 5-year survival in patients with ischaemic stroke and obstructive sleep apnea: a randomized controlled trial

The main purpose of the present analysis is to assess the influence of introducing early nasal continuous positive airway pressure (nCPAP) treatment on cardiovascular recurrences and mortality in patients with a first-ever ischaemic stroke and moderate-severe obstructive sleep apnea (OSA) with an apnea-hypopnea index (AHI) ≥20 events h(-1) during a 5-year follow-up. Patients received conventional treatment for stroke and were assigned randomly to the nCPAP group (n = 71) or the control group (n = 69). Cardiovascular events and mortality were registered for all patients. Survival and cardiovascular event-free survival analysis were performed after 5-year follow-up using the Kaplan-Meier test. Patients in the nCPAP group had significantly higher cardiovascular survival than the control group (100 versus 89.9%, log-rank test 5.887; P = 0.015) However, and also despite a positive tendency, there were no significant differences in the cardiovascular event-free survival at 68 months between the nCPAP and control groups (89.5 versus 75.4%, log-rank test 3.565; P = 0.059). Early nCPAP therapy has a positive effect on long-term survival in ischaemic stroke patients and moderate-severe OSA.

Cognitive profile in patients with a first-ever lacunar infarct with and without silent lacunes: a comparative study

BACKGROUND

The detection of early neuropsychological abnormalities as precursors of cognitive decline of vascular origin in patients with lacunar stroke is a subject of increasing interest. The objective of this study was to assess whether there were differences in the performance of a battery of neuropsychological tests in first-ever lacunar stroke patients with and without associated silent multiple lacunar infarctions found incidentally on the brain magnetic resonance imaging (MRI) scan.

METHODS

A total of 72 consecutive patients with first-ever lacunar infarction were studied 1 month after stroke. All patients underwent a comprehensive neuropsychological evaluation, which included the California Verbal Learning Test (CVLT), Phonetic Verbal Fluency Test (PMR), Semantic Verbal Fluency Test (category "animals"), Digit Span Forward and Backward from the Wechsler Adult Intelligence Scale (WAIS-III), and Mini-Mental State Examination (MMSE).

RESULTS

A total of 38 patients (52.7%) had silent multiple lacunar infarcts, with corona radiata as the most frequent topography (P < 0.023). White matter hyperintensities (leukoaraiosis) were observed in 81.1% of patients with silent multiple lacunar infarcts and in 50% with a single lacunar infarction (P < 0.007). Patients in both groups showed similar scores in the MMSE, but those with associated silent lacunar infarctions showed a poorer performance in the semantic fluency test (P < 0.008) and in short delayed verbal memory (P < 0.001). In both cases, however, leukoaraiosis was not statistically significant in multivariate linear regression models adjusted by confounding covariates. In these models, multiple silent lacunar infarctions and education were independent predictors of poor performance in the semantic fluency test and in short delayed verbal memory.

CONCLUSIONS

The presence of silent multiple lacunar infarctions documented on brain MRI scans in patients with first-ever lacunar stroke was associated with mild neuropsychological abnormalities, particularly in the performance of executive functions (semantic fluency) and short delayed verbal memory. According to these findings, in the initial stages of small vessel disease, mild neuropsychological abnormalities appear to be related to lacunes rather than to leukoaraiosis or perivascular hyperintensities of vascular cause.

Trends in clinical features and early outcome in patients with acute cardioembolic stroke subtype over a 19-year period

OBJECTIVES

To assess changing trends in clinical characteristics and early outcome of patients with acute cardioembolic stroke (ACS) over a 19-year period.

MATERIALS AND METHODS

Data of 575 patients with first-ever ACS included in the Sagrat Cor Hospital of Barcelona Stroke Registry were analyzed. Changing trends for 1986-1992, 1993-1998, and 1999-2004 periods were compared.

RESULTS

A statistically significant increase (P < 0.001) in the age of patients (74.6 years in 1986-1992 vs. 81.4 years in 1999-2004) and the percentage of patients older than 85 years of age (16% vs. 38.2%) was observed. Patients with hypertension increased from 40.5 to 60.8% (P = 0.001) as were patients with diabetes, chronic bronchitis, and obesity (P = NS). The median length of hospital stay decreased from 18 to 12 days (P = 0.031) and prolonged hospital stay (>12 days) from 18.3 to 13.1 (P = 0.033). In-hospital death rate remained around 20%.

CONCLUSIONS

ACS continues to be a severe ischemic stroke subtype with high risk of in-hospital death. The lack of improvement in the early prognosis over a 19-year period may be explained by an increase in the prevalence of major cardiovascular risk factors and progressive aging of the population.

Infarctions in the vascular territory of the posterior cerebral artery: clinical features in 232 patients

Background

Ischemic stroke caused by infarction in the territory of the posterior cerebral artery (PCA) has not been studied as extensively as infarctions in other vascular territories. This single centre, retrospective clinical study was conducted a) to describe salient characteristics of stroke patients with PCA infarction, b) to compare data of these patients with those with ischaemic stroke due to middle cerebral artery (MCA) and anterior cerebral artery (ACA) infarctions, and c) to identify predictors of PCA stroke.

Findings

A total of 232 patients with PCA stroke were included in the "Sagrat Cor Hospital of Barcelona Stroke Registry" during a period of 19 years (1986-2004). Data from stroke patients are entered in the stroke registry following a standardized protocol with 161 items regarding demographics, risk factors, clinical features, laboratory and neuroimaging data, complications and outcome. The characteristics of these 232 patients with PCA stroke were compared with those of the 1355 patients with MCA infarctions and 51 patients with ACA infarctions included in the registry.

Infarctions of the PCA accounted for 6.8% of all cases of stroke (n = 3808) and 9.6% of cerebral infarctions (n = 2704). Lacunar infarction was the most frequent stroke subtype (34.5%) followed by atherothrombotic infarction (29.3%) and cardioembolic infarction (21.6%). In-hospital mortality was 3.9% (n = 9). Forty-five patients (19.4%) were symptom-free at hospital discharge. Hemianopia (odds ratio [OR] = 6.43), lacunar stroke subtype (OR = 2.18), symptom-free at discharge (OR = 1.92), limb weakness (OR = 0.10), speech disorders (OR = 0.33) and cardioembolism (OR = 0.65) were independent variables of PCA stroke in comparison with MCA infarction, whereas sensory deficit (OR = 2.36), limb weakness (OR = 0.11) and cardioembolism as stroke mechanism (OR = 0.43) were independent variables associated with PCA stroke in comparison with ACA infarction.

Conclusions

Lacunar stroke is the main subtype of infarction occurring in the PCA territory. Several clinical features are more frequent in stroke patients with PCA infarction than in patients with ischaemic stroke due to infarction in the MCA and ACA territories. In-hospital mortality in patients with PCA territory is low.

Early treatment of obstructive apnoea and stroke outcome: a randomised controlled trial

The aim of the present study was to assess the impact of nasal continuous positive airway pressure (nCPAP) in ischaemic stroke patients followed for 2 yrs. Stroke patients with an apnoea-hypopnoea index ≥ 20 events·h⁻¹ were randomised to early nCPAP (n = 71; 3-6 days after stroke onset) or conventional treatment (n = 69). The Barthel Index, Canadian Scale, Rankin Scale and Short Form-36 were measured at baseline, and at 1, 3, 12 and 24 months. The percentage of patients with neurological improvement 1 month after stroke was significantly higher in the nCPAP group (Rankin scale 90.9 versus 56.3% (p < 0.01); Canadian scale 88.2 versus 72.7% (p < 0.05)). The mean time until the appearance of cardiovascular events was longer in the nCPAP group (14.9 versus 7.9 months; p = 0.044), although cardiovascular event-free survival after 24 months was similar in both groups. The cardiovascular mortality rate was 0% in the nCPAP group and 4.3% in the control group (p = 0.161). Early use of nCPAP seems to accelerate neurological recovery and to delay the appearance of cardiovascular events, although an improvement in patients' survival or quality of life was not shown.

Clinical predictors of lacunar syndrome not due to lacunar infarction

BACKGROUND

Lacunar syndrome not due to lacunar infarct is poorly characterised. This single centre, retrospective study was conducted to describe the clinical characteristics of patients with lacunar syndrome not due to lacunar infarct and to identify clinical predictors of this variant of lacunar stroke.

METHODS

A total of 146 patients with lacunar syndrome not due to lacunar infarction were included in the "Sagrat Cor Hospital of Barcelona Stroke Registry" during a period of 19 years (1986-2004). Data from stroke patients are entered in the stroke registry following a standardized protocol with 161 items regarding demographics, risk factors, clinical features, laboratory and neuroimaging data, complications and outcome. The characteristics of these 146 patients with lacunar syndrome not due to lacunar infarct were compared with those of the 733 patients with lacunar infarction.

RESULTS

Lacunar syndrome not due to lacunar infarct accounted for 16.6% (146/879) of all cases of lacunar stroke. Subtypes of lacunar syndromes included pure motor stroke in 63 patients, sensorimotor stroke in 51, pure sensory stroke in 14, atypical lacunar syndrome in 9, ataxic hemiparesis in 5 and dysarthria-clumsy hand in 4. Valvular heart disease, atrial fibrillation, sudden onset, limb weakness and sensory symptoms were significantly more frequent among patients with lacunar syndrome not due to lacunar infarct than in those with lacunar infarction, whereas diabetes was less frequent. In the multivariate analysis, atrial fibrillation (OR = 4.62), sensorimotor stroke (OR = 4.05), limb weakness (OR = 2.09), sudden onset (OR = 2.06) and age (OR = 0.96) were independent predictors of lacunar syndrome not due to lacunar infarct.

CONCLUSIONS

Although lacunar syndromes are highly suggestive of small deep cerebral infarctions, lacunar syndromes not due to lacunar infarcts are found in 16.6% of cases. The presence of sensorimotor stroke, limb weakness and sudden onset in a patient with atrial fibrillation should alert the clinician to the possibility of a lacunar syndrome not due to a lacunar infarct.

Determinants of early outcome in spontaneous lobar cerebral hemorrhage

OBJECTIVE

To identify determinants of early outcome in spontaneous lobar hemorrhage.

MATERIALS AND METHODS

From 2500 acute stroke patients included in a prospective hospital-based stroke registry over a 12-year period, 97 cases of lobar hematoma were selected. Determinants of in-hospital mortality were studied in multiple regression models.

RESULTS

Lobar hematomas accounted for 3.9% of all acute stroke patients and 35.9% of intracerebral hemorrhages. The presence of chronic obstructive pulmonary disease (COPD) was a significant predictive variable in the model based on demographic variables and vascular risk factors [odds ratio (OR): 17.18; 95% CI: 1.77-166.22] and in the model based on these variables plus clinical data (OR: 15.12; 95% CI: 1.27-179.59). Other predictive variables included altered consciousness, previous cerebral infarct and chronic liver disease.

CONCLUSIONS

COPD appeared as the most important predictor of death during hospitalization after lobar cerebral hemorrhage, a finding not generally acknowledged earlier.

Effects of pulp and paper mill effluents on the microplankton and microbial self-purification capabilities of the Biobío River, Chile

Most studies focus on the ecotoxicity of pulp and paper mill effluents, rather than on how they affect the physicochemical and biological structure and the intrinsic ecological capabilities of the receiving watercourses. We investigated the impact of such effluents on the water quality, microplankton system and microbial self-purification capacity (degradation of polymeric organic compounds via extracellular enzymes) of the Biobío River in Chile. The physicochemical impact on the water quality was indicated by raised conductivity, by the pollution of the water body with nitrate, nitrite and soluble reactive phosphorus, by the appearance of tannin and lignin, and by the steady accumulation of inorganic and organic suspended matter (SPM) along the river. From the biological structure of the microplankton system, very low and declining concentrations of chlorophyll a and heterotrophic flagellate densities were determined. The pulp and paper mill effluents introduced high bacterial abundances and biomass concentrations into the river water. This reflects the effective use made of the abundantly available inorganic and organic nutrients within this industrial and municipal process water by bacteria adapted to these extreme environments, additionally supported by concomitant low grazing pressure derivable from low heterotrophic flagellate abundances. Indeed, in one section of the river affected by a pulp mill, the plant was found to significantly contribute to the self-cleaning capacity of the river. However, this elevated degradation capacity was not enough to compensate for the additionally discharged organic material which, together with the toxic effects of the paper plant effluents, significantly interferes with the ecological status of the Biobío River.

Sleep-related breathing disorders: impact on mortality of cerebrovascular disease

The aim of the study was to analyse the impact of sleep-related breathing disorders in a 2-yr survival follow-up of patients with a first ever stroke or transient ischaemic attack. The study followed 161 patients. Complete neurological assessment was performed in order to determine cerebrovascular risk factors, functional disability, and parenchymatous and vascular localisation, as well as stroke subtype categorisation. A sleep study was carried out using a portable respiratory recording device, The entire cohort was followed over a mean period of 22.8 months. The main outcome event was death and time of survival since the neurological event. A multivariate Cox's model was estimated. The patients were ages 72+/-9 yrs (mean+/-SD), and had a body mass index of 26.6+/-3.9 kg x m(-2) and apnoea/hypopnoea index (AHI) of 21.2+/-15.7. Overall, mortality occurred in 22 cases, and the survival rate was 86.3%. Vascular disease accounted for 63.6% of deaths. Multivariate analysis selected four independent variables associated with mortality: 1) age; 2) AHI, with an implied 5% increase in mortality risk for each additional unit of AHI; 3) involvement of the middle cerebral artery; and 4) the presence of coronary disease. In conclusion, the findings suggest that sleep-related breathing disorders are an independent prognostic factor related to mortality after a first episode of stroke.

Preliminary study of prairies forested with Eucalyptus sp. at the northwestern Uruguayan soils

The land cover change of Uruguayan Forestal Plan provoked biogeochemical changes on horizon Au(1) of Argiudols; in native prairies which were replaced by monoculture Eucalyptus sp. plantation with 20 year rotations as trees. Five fields forested and six natural prairies were compared. The results not only show a statistical significant soil acidification, diminution of soil organic carbon, increase of aliphaticity degree of humic substances, and increase of affinity and capacity of hydrolytic activity from soil microbial communities for forested sites with Eucalyptus sp. but also, a tendency of podzolization and/or mineralization by this kind of land cover changes, with a net soil organic lost of 16.6 tons ha(-1) in the horizon Au(1) of soil under Eucalyptus sp. plantation compared with prairie. Besides, these results point out the necessity of correction of the methodology used by assigned Uruguayan commission to assess the national net emission of greenhouse gases, since the mineralization and/or podzolization process detected in forested soil imply a overestimation of soil organic carbon. The biochemical parameters show a statistical significant correlation between the soil organic carbon status and these parameters which were presented as essential for the correct evaluation of Uruguayan soil carbon sink.

Ehrlichia platys (Anaplasma platys) in dogs from Maracaibo, Venezuela: an ultrastructural study of experimental and natural infections

Since 1982 Ehrlichia platys, now emended as Anaplasma platys, has been diagnosed in dogs from Maracaibo, Venezuela, using buffy coat smears stained with Dip Quick. Three dogs were inoculated with an A. platys strain. When parasitemia reached 60-97%, blood samples obtained from the inoculated dogs and from two naturally infected dogs were centrifuged to obtain platelet-rich plasma, which was mixed with 0.1% glutaraldehyde at 37 C for 10 minutes. Platelet pellets were fixed in 3% glutaraldehyde for 72 hours and processed for conventional transmission electron microscopy. Platelets contained pleomorphic organisms with a distinct double membrane that was not observed when the bodies were in a determinate developmental stage. There were 1-15 individual bodies included in a host cell vacuole. The organisms had an electron-lucent inner area, whereas the internal surface of their inner plasma membranes exhibited an electron-dense rough substance. In naturally infected dogs, organisms with different ultrastructural features were found inside the same platelet. Some organisms contained central dense material surrounded by a pale zone, which was in turn surrounded by a moderately dense peripheral area. Other organisms contained an eccentrically electron-dense material. The intravacuolar space appeared fully electron-lucent. Each organism usually exhibited inner fine strands. Empty structures displaying junctions with the vacuolar membrane were observed. Our results indicate that distinct ultrastructural characteristics are associated with different stages of A. platys development and may differ among A. platys strains.

Bioavailability of PAHs in the Biobio river (Chile): MFO activity and biliary fluorescence in juvenile Oncorhynchus mykiss

Cytochrome P450-dependent monooxygenase (MFO) activity and levels of bile PAH metabolites were measured in fish (Oncorhynchus mykiss) exposed to Biobio river (Chile) water. Experiments were performed simultaneously in both the field and laboratory to investigate whether the river water contained notable bioavailable PAH fractions. The field experiment was conducted using fish caged for 41 days at La Mochita (Biobio river mouth) whereas the laboratory experiment involved a 21-day exposure treatment with water collected in the same area. Induction of hepatic MFO, assayed by benzo(a)pyrene monooxygenase activity (BaPMO), and levels of PAH metabolites in the bile were measured in groups of eight (field experiment) and four specimens (laboratory experiment) sampled after 5, 10, 21 and 41 days of exposure. BaPMO was induced by a factor of 23 and 25 in fish caged for 21 and 41 days, respectively. Likewise, a significant BaPMO induction was found in the fish group experimentally exposed to river water for 21 days. Biliary fluorescence measurements, recorded by fixed wavelength fluorescence (FF) and synchronous fluorescence spectroscopy (SFS), revealed significantly high levels of PAH metabolites in bile samples of fish caged for 21 and 41 days. A positive relationship was found between BaPMO activity and biliary PAH metabolites. This study provides evidences that (i) Biobio river water contains a significant bioavailable PAH fraction in terms of marked effects on fish and (ii) the biological indicators MFO activity and bile PAH metabolites represent an excellent screening methodology to assess PAH exposure.

First report on chlorinated pesticide deposition in a sediment core from a small lake in central Chile

This paper presents a first report on chlorinated pesticide deposition analyzed through sedimentary records in a small mesotrophic lake (Chica de San Pedro) in central Chile. The sediment core was sliced and dated using 210Pb, 137Cs and pollen analyses. Organochlorine pesticides were analyzed by gas chromatography with electron capture detection (GC-ECD). From these results, pesticide deposition over the last 50 years was estimated. No pesticides were detected below the 1940 slice of the core. Concentrations were in the range 0.640-1.4 ng/g d.w. for total DDTs, 0.046-0.362 ng/g d.w. for lindane and 0.015-0.310 ng/g d.w. for alpha-hexachlorohexane. Highest concentrations of pp'DDT were found in 1993-1996 and higher concentrations of pp'-DDE and pp'-DDD were found in the seventies (1972-1978). Total organic carbon (TOC) normalized data were used for statistical analysis. Although significant correlation was observed between concentrations of DDE and DDD, no correlation was found for DDT, suggesting that it had a different source. Factorial analysis grouped DDE together with DDD, while DDT was grouped together with gamma- and alpha-HCH. Total DDT fluxes were highest during the 1970s, while those for HCHs have been increasing in the 1990s. In Chile, organochlorine compounds were banned in 1985, and the historical deposition patterns seem to indicate that such measures have been effective. On the other hand, results point out a relatively new occurrence of pp'-DDT in the watershed, but the source remains unknown.

Porphyrin levels in excreta of sea birds of the Chilean coasts as nondestructive biomarker of exposure to environmental pollutants

In this preliminary study on sea birds we propose the use of porphyrins in excreta as a biomarker of exposure to contaminants. Samples of excreta were obtained from colonies of brown pelicans (Pelecanus occidentalis thagus), neotropic cormorants (Phalacrocorax olivaceus), and kelp gulls (Larus dominicanus) in three areas of the south coast of Chile with different human impact (Tubul, Talcahuano, and Valdivia). They were analyzed for porphyrin content (copro-, uro-, and protoporphyrins and total porphyrins) by a rapid fluorimetric method and by HPLC. The main outcomes of the study were: (a) kelp gulls and neotropic cormorants living in areas with high human impact showed a clear capacity to accumulate and eliminate porphyrins in the excreta; (b) species-related accumulation capacities are likely, as shown by the different levels found in different species living in the same area; (c) the porphyrin profile obtained by fluorimetry and HPLC showed a higher percentage of protoporphyrin than the other porphyrins; (d) although the fluorimetric method of Grandchamp is semiquantitative, it was found to be sensitive enough to detect differences in samples from field studies. The positive results of this preliminary study make it possible to propose this nondestructive method for a variety of field applications.

Time course of sleep-related breathing disorders in first-ever stroke or transient ischemic attack

To investigate the prevalence and behavior of sleep-related breathing disorders (SRBDs) associated with a first-ever stroke or transient ischemic attack (TIA), we prospectively studied 161 consecutive patients admitted to our stroke unit. Complete neurological assessment was performed to determine parenchymatous and vascular localization of the neurological lesion. Stroke subtype was categorized as TIA, ischemic (IS), or hemorrhagic (HS). A portable respiratory recording (PRR) study was performed within 48-72 h after admission (acute phase), and subsequently after 3 mo (stable phase). During the acute phase, 116 patients (71.4%) had an apnea-hypopnea index (AHI) > 10 events/h and 45 (28%) had an AHI > 30. No relationships were found between sleep-related respiratory events and the topographical parenchymatous location of the neurological lesion or vascular involvement. Cheyne-Stokes breathing (CSB) was observed in 42 cases (26.1%). There were no significant differences in SRBD according to the stroke subtype except for the central apnea index (CAI). During the stable phase a second PRR was performed in 86 patients: 53 of 86 had an AHI > 10 and 17 of 86 had an AHI > 30. The AHI and CAI were significantly lower than those in the acute phase (16.9 +/- 13.8 versus 22.4 +/- 17.3 and 3.3 +/- 7.6 versus 6.2 +/- 10.2, respectively) (p < 0.05) while the obstructive apnea index (OAI) remained unchanged. CSB was observed in 6 of 86 patients. The prevalence of SRBD in patients with first-ever stroke or TIA is higher than expected from the available epidemiological data in our country. No correlation was found between neurological location and the presence or type of SRBD. Obstructive events seem to be a condition prior to the neurological disease whereas central events and CSB could be its consequence.

Blood metabolites and their relationship with production variables in dual-purpose cows in Venezuela

A survey was carried out on 79 lactating Bos taurus/indicus cross-bred cows on three dual-purpose cattle farms to measure the blood concentration of metabolites and to evaluate possible relationships with nutritional status and productive variables. A rotational grazing system on Star grass and other tropical pastures (10-12% CP in leaves) was used and 2-3 kg/cow/day of concentrate were fed on two farms. Restricted calf suckling was used in two herds. Average milk yield sold per farm was 6 kg/day/cow and body condition scores (BCS) were between 3.0 and 3.8 on a scale of one-to-five. On two farms, the average interval from calving to conception (ICC) was more than 145 days. Mean blood concentrations of albumin, globulin, urea, beta-hydroxybutyrate and phosphorus were generally within reference values, but a significant group of cows had low levels of albumin and urea and high levels of globulin. Packed cell volume (PCV) was below normal values, with anemia in 63% of cows during the second trimester of lactation, which was negatively correlated to milk yield. The high incidence of anemia could be related to factors such as hematophagic parasites, not evaluated in this study. ICC values were negatively related to albumin level and could be associated with protein deficiency in the diet or with disease, as globulin values were high in many cows. Based on these diagnoses, an experiment was carried out on one of the farms to evaluate the influence of supplementation with 0.5 kg/cow/day of fish meal. Total milk yield was not influenced by the fish meal and reproductive efficiency was high in the two supplemental treatments. It was shown that supplementation with undergraded protein is not required in these cows.

Should patients with sleep apnoea/hypopnoea syndrome be diagnosed and managed on the basis of home sleep studies?

The purpose of this study was to analyse the validity and the economic efficiency of a portable monitor of respiratory parameters (PMRP), used in a home setting for the diagnosis of sleep apnoea/hypopnoea syndrome (SAHS). Eighty nine patients with suspected SAHS were studied in two settings: in the sleep laboratory using full-polysomnography (full-PSG); and at the patient's home using a PMRP. In the home setting, 50 patients were assisted by a technician and 39 set up the equipment themselves. SAHS (apnoea/hypopnoea index (AHI) >10 events x h(-1) by means of full-PSG) was diagnosed in 75 of the 89 patients. An acceptable agreement was obtained between the AHI measured by full-PSG and PMRP, according to the Bland and Altman method of concordance (mean bias 2.56; 95% confidence interval 3.25). Sensitivity and specificity of PMRP were adequate for diagnostic purposes; however, their values rely on the prior PMRP-AHI cut-off point selected with reference to full-PSG-AHI >10. The clinical therapeutic decision taken after PMRP agreed with that taken with full-PSG in 79 patients (89%). Although 10% of the studies with an individual set-up needed repetition, both of the domiciliary modalities (with and without a technician's intervention) were, economically, about three times more efficient than full-PSG. In conclusion, we believe that patients with a suspected sleep apnoea/hypopnoea syndrome should initially be studied in a home setting with a portable monitor of respiratory parameters, since it is a reliable method with an acceptable cost-effective profile.

Persistent organochlorine residues in fish and water birds from the Biobio river, Chile

Concentrations of polychlorinated biphenyls (PCBs), DDT and its metabolites, HCH isomers and hexachlorobenzene (HCB) were determined in fish and birds from different locations in the Biobio river basin (central Chile). Samples collected near the mouth of the river contained high concentrations of PCBs, reflecting the massive use of these xenobiotics in the urban and industrial areas of Concepcion and Talcauano. Samples collected in the central part of the basin contained very high concentrations of lindane that coincide with the widespread use of lindane-based pesticides (purified γ-HCH) in this area. DDT was distributed homogeneously throughout the basin, except at Laguna Icalma, the source of the river in the Andes. Most PCB residues in fish and birds consisted of congeners between penta- and hepta-chlorobiphenyls. In fish, the predominant congeners were the pentachlorobiphenyl 23'44'5 (IUPAC number 118) and the hexachlorobiphenyl 22'344'55' (PCB-153); in birds 22'44'55' (PCB-180) prevailed.

Comparison of partially attended night time respiratory recordings and full polysomnography in patients with suspected sleep apnoea/hypopnoea syndrome

BACKGROUND

Laboratory full polysomnography (PSG) is considered to be the gold standard for the diagnosis of the sleep apnoea/hypopnoea syndrome (SAHS), but it is expensive and time consuming. A study was undertaken to evaluate the diagnostic usefulness of a partially attended night time respiratory recording (NTRR) and a clinical questionnaire in patients with suspected SAHS in comparison with full PSG.

METHODS

Seventy six patients (54 men) of mean (SD) age 51 (11.5) years with a body mass index of 31 (5.7) kg/m2 were studied at random on two different nights with full PSG at the sleep laboratory and with NTRR on a respiratory ward. NTRR records oximetry, airflow, chest and abdominal motion. All signals were continuously displayed on a computer screen throughout the night and respiratory events were scored automatically the following morning. All patients completed a clinical questionnaire.

RESULTS

Mean values of the apnoea/hypopnoea index (AHI) using NTRR were lower than those obtained with full PSG (22.7 (2.4) versus 32.2 (3) events/hour) which was mainly due to underrecognition of hypopnoeas. Sensitivity and specificity of NTRR for the diagnosis of SAHS were 82% and 90%, respectively, taking as reference AHI > 10 on full PSG (AHI-PSG > 10). The mean (+/-2SD) difference in AHI between the two methods was 9.6 (range -5.4-24.6) (95% confidence interval 6.2 to 13). Symptoms of witnessed apnoeas, impotence, the overall clinical impression of a trained physician, and a neck size over 40 cm were significantly more prevalent in patients with AHI-PSG of > 10, but impotence was the only clinical feature significantly more prevalent in patients with false negative compared with true negative NTRR results that helped to distinguish patients with NTRR < 10 but AHI-PSG > 10.

CONCLUSIONS

NTRR is a helpful and easy complementary diagnostic tool in clinical practice because it detects patients with moderate to severe SAHS reasonably well and therefore can be useful for confirming a diagnosis of SAHS and also for treatment decisions. It is suggested that patients with suspicion of SAHS should be initially studied by NTRR. When NTRR is negative, a full PSG should be performed if witnessed apnoeas, impotence, systemic hypertension, ischaemic heart disease, and a trained physician's clinical impression of SAHS are present.

Determination of aromatic metabolites in ruminant urine by high-performance liquid chromatography

A method based on reversed-phase HPLC is reported for the separation and quantification of various urinary aromatic metabolites: hippuric, phenylaceturic, salicyluric, benzoic, phenylacetic, salicylic, 3-phenylpropionic and cinnamic acids and several phenols in ruminant urine. In this method, a Nova-Pak C18 (4 microns) 150 x 3.9 mm I.D. column, two solvents [A: 15% methanol in 20 mM acetic acid (pH 3.3); B: methanol) in a gradient mode at a flow-rate of 0.8 ml/min, and UV detection at 210 nm were used. Quantification of the total (free and conjugated) benzoic, phenylacetic and salicylic acids present in urine was achieved by hydrolysis of the samples in 3 M HCl at 100 degrees C for 24 h prior to HPLC analysis. The lowest detection concentration was 50 mumol/l. This method is useful for scanning the profile of aromatic metabolites in urine of ruminants, which provides information on the diets the animals receive.

[Human ehrlichiosis: report of the 1st case in Venezuela]

Human ehrlichiosis is a zoonotic disease, caused by a rickettsia that infects leukocytes. It was described for the first time in the United States of America in 1986. More than 300 cases have been reported in that country. One case has been reported in Portugal, two in France and one more in a tourist coming from Mali (Africa). In Venezuela, a tropical country, where ehrlichiosis is endemic in dogs and horses, the first case of human ehrlichiosis is reported in a seventeen month old girl. She initially had symptoms compatible with a viral illness. Then she developed a rash, acute respiratory failure, hepato-splenomegaly, neurologic abnormalities, renal failure and hematologic alterations including pancytopenia and disseminated intravascular coagulation (DIC). Different diagnoses were given before it was concluded that it was a case of ehrlichiosis. She was treated with tetracycline and very soon recovered. The initial diagnosis was made using buffy coat blood smears stained with Diff Quick Stain. Indirect Immunofluorescence (IFA) test was used to detect antibodies against Ehrlichia chaffeensis (1:126) but not to other rickettsias. Also the presence of platelets with ehrlichia bodies similar to E. platys from dogs, it was demonstrated, in peripheral blood from the child. The presence of these bodies in human platelets has not been previously reported. In this case, it could not be proved that the disease was transmitted by a tick bite. The presence of ehrlichia bodies in platelets from the girl's peripheral blood is also described.

Prognostic factors of pneumonia requiring admission to the intensive care unit

All patients with severe pneumonias (community-acquired and nosocomial) who required treatment in the intensive care unit (ICU) were included in a 3-year prospective study. Predictive factors for a fatal outcome were analyzed in 127 patients. An etiologic diagnosis was made in 70 (55.1%) patients. Culture of sputum or tracheobronchial secretions were used only as criteria for microbiologic diagnosis of Legionella pneumophila. The pathogens most frequently identified were L pneumophila, Streptococcus pneumoniae, and Pseudomonas aeruginosa. Viruses were not detected as causative agents. A total of 54 patients died (mortality rate, 42.5%). The univariate analysis showed the following factors associated with mortality: advanced age (> or = 70 years); presence of septic shock, requirement of mechanical ventilation, and Simplified Acute Physiology Score [SAPS] index > 12 at the time of admission to the ICU or when symptoms appeared in patients already admitted to the ICU; development of any complication during ICU hospitalization; and P aeruginosa as the etiologic agent of the pneumonia. When all variables were introduced by a stepwise method, the final model included advanced age (> or = 70 years), SAPS index > 12, presence of septic shock, requirement of mechanical ventilation, bilateral pulmonary involvement, and P aeruginosa as the etiologic agent of pneumonia as prognostic factors associated with a fatal outcome.

[A decrease in the level of CPAP required after prolonged treatment in patients with the obstructive sleep apnea syndrome]

Application of continuous positive upper airway pressure (CPAP) is the treatment of choice in obstructive sleep apnea syndrome (OSAS). CPAP keeps the upper airway open by providing a "pneumatic splint" on the pharyngeal walls. However, it has been suggested that prolonged nasal CPAP treatment may also improve the physiopathological mechanisms responsible for OSAS by a variety of mechanisms such as the reduction of edema of the pharyngeal mucosa, modification of upper airway muscle dynamics; there may even be a reduction in the intensity of phenomena responsible for brief awakening and ending of apneic episodes. The objective of this study was to determine whether prolonged nasal CPAP is associated to a reduction of CPAP pressure required for eliminating apnea in patients with OSAS. We studied 22 patients (4 women) with OSAS diagnosed by conventional polysomnography, including study of neurological variables during sleep (electroencephalogram, ocular movement, submental electromyogram), respiratory variables (nasal air flow, thoracic-abdominal movement, O2 saturation in the blood), and others (electrocardiogram, leg movement). Treatment was exclusively with nasal CPAP. All 22 patients were middle-aged (52.3 +/- 10 years), presented a mean apnea/hypoapnea index of 65.2 +/- 24 per hour. CPAP levels needed to eliminate episodes of apnea, blood O2 desaturation and snoring at the time of diagnosis and after long-term treatment (8.5 +/- 4.6 months) were applied. Weight was recorder at both measurement times. Eighteen of the 22 patients (1 woman, mean age 53.1 +/- 11.4 years and apnea/hypopnea index 64.8 +/- 23.4 per hour) experienced no weight change during treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Hygroscopic condenser humidifier as a solution to nasal dryness due to nasal CPAP treatment for obstructive sleep apnea syndrome

We report an apparent solution to nasal dryness for patients with obstructive sleep apnea syndrome treated with nasal continuous positive airway pressure (CPAP) when a hygroscopic condenser humidifier is introduced into the CPAP circuit. Six patients underwent a 5-h test period of nasal CPAP therapy with a mask containing a hygroscopic humidifier. The water vapor showed a statistically significant increase in both inspired and expired gases. The relative humidity of the inspired gases increased significantly. The levels of O2 and CO2 in the respired gases did not change. When patients were asked about nasal dryness at the end of the test, all of them reported marked improvement.

Amiodarone toxicity: recurrence of interstitial pneumonitis after withdrawal of the drug

Amiodarone hydrochloride, an iodinated benzofuran derivative, is effective for treatment of supraventricular and ventricular arrhythmias. Pulmonary fibrosis has been reported after treatment with this drug. We present a patient with amiodarone pulmonary toxicity, who initially responded to corticosteroid therapy, but who developed a clinical relapse two months after withdrawal of the drug.

Amiodarone toxicity: recurrence of interstitial pneumonitis after withdrawal of the drug

Amiodarone hydrochloride, an iodinated benzofuran derivative, is effective for treatment of supraventricular and ventricular arrhythmias. Pulmonary fibrosis has been reported after treatment with this drug. We present a patient with amiodarone pulmonary toxicity, who initially responded to corticosteroid therapy, but who developed a clinical relapse two months after withdrawal of the drug.

[Early detection of tuberculosis by the evaluation of contacts]

We have evaluated the close contacts of 191 patients diagnosed of tuberculosis in our center between 1984 and 1987. The overall number of evaluated contacts was 666, and the mean number of contacts for each index case was 3.7. In 55% of the evaluated population PPD reaction was positive, and their mean age was 33.3 years. In 132 cases chemoprophylaxis was given during one year (22%). Forty-one new cases of tuberculosis were detected, with a mean age of 25.6 years. In ten new cases the source of infection was familial. When the contacts were distributed according to the bacteriologic status of the index case (direct investigation of tubercle bacilli positive in 103 cases and negative in 167), the rate of disease and infection was significantly higher among those related to positive patients. In the group related to negative patients we discovered 7 new cases of active tuberculosis. Our results confirm the usefulness of the systematic evaluation of the contacts of tuberculous patients in our area, as it permits the identification of an important number of new patients which should be adequately treated. This practice contributes to interrupt the epidemiologic transmission chain of the disease and to facilitate its eradication.