Virtual fractional flow reserve derived from coronary angiography – artery and lesion specific correlations

Introduction

Virtual Fractional flow reserve (vFFR) from standard non-hyperaemic invasive coronary angiography (ICA) has emerged as a promising non-invasive test to assess hemodynamic severity of coronary artery disease (CAD).

Purpose

To investigate the difference in vFFR analysis between vessels and specific lesions.

Methods

Retrospective analysis of consecutive patients (pts) who underwent invasive functional assessment (iFA) in a tertiary center between 2019 and 2020. vFFR was calculated using dedicated software (CAAS Workstation 8.4) based on coronary angiograms of the acquired in ≥2 different projections, by operators blinded to iFA results. Diagnostic performance of vFFR was evaluated and correlated with iFA, according to coronary vessel, vessel diameter at stenosis, diameter stenosis and area stenosis at lesion. vFFR was considered positive when <0.80. FFR <0.8 and iFR/RFR <0.90 were classified as positive according to current clinical standards.

Results

106 coronary arteries of 95 pts (78% male, mean age 67.8±9.7 years) underwent vFFR evaluation. ICA indications were chronic coronary syndrome in 63% or acute coronary syndrome (non-culprit lesion) in the remaining pts. VFFR accuracy was good (AUC 0.839 (p<0.001) and Pearson's correlation coefficient 0.533 (p<0.001) when vFFR was measured in the distal vessel segment. The correlation improved when vFFR were assessed at lesion site (r=0.631, p<0.001) or up to 1cm below the stenosis (0.610, p<0.001). Binary concordance of 89% were observed in RCA and LAD (Sensibility -S 68%, Specificity-Sp 96%, False positive -FP 3.8%, False negative - FN 31%, predictive positive value-PPV 87%, predictive negative value- PNV 89%), while in the circumflex coronary artery binary concordance were of 77% (S 50%; Sp 82%; FP 18%; FN 50%; PPV 33% and PNV 90%). Correlation between vFFR and iFA was higher in vessels ≥2mm (r=0.730, p<0.001). and in lesions in the extremes of the severity spectrum (Table 1).

Conclusion

vFFR has a moderate to high linear correlation to iFA, depending on the artery and type of lesion studied. The higher correlation was found when vFFR were measured at lesion site, in non-circumflex artery stenosis, in vessels ≥2mm and in vessels with mild or severe stenosis.

Funding Acknowledgement

Type of funding sources: None.

Feasibility of virtual fractional flow reserve derived from coronary angiography and its correlation with invasive functional assessment

Introduction

Invasive functional assessment (iFA) of coronary artery disease (CAD) needs expensive devices, has potential procedure-related complications and is still underutilized. Virtual Fractional Flow Reserve (vFFR) derived from invasive coronary angiography (ICA) has the potential to overcome these limitations.

Purpose

To investigate the feasibility of vFFR analysis and its correlation with iFA (iFR, RFR or FFR).

Methods

Retrospective analysis of consecutive patients (pts) who underwent iFA in a tertiary center between 2019 and 2020. vFFR was calculated using a dedicated software (CAAS Workstation 8.4) based on standard non-hyperaemic coronary angiograms acquired in ≥2 different projections, by operators blinded to iFA results. Diagnostic performance and accuracy of vFFR were evaluated. vFFR was considered positive when <0.80. FFR <0.8 and iFR/RFR <0.90 were classified as positive according to current clinical standards.

Results

Out of 113 coronary arteries of 102 pts, vFFR was successfully analysed in 106 (94%). Reasons for vFFR analysis failure were: vessel projection overlap (48%), <2 angiographic projections (28%) and table movement while acquisition (24%). From 106 coronary arteries of 95 pts with analysable vFFR (78% male, mean age 67.8±9.7 years), 90 (85%) showed agreement with the respective iFA result. The vFFR predicted which lesions were physiologically significant and which were not with accuracy, sensitivity, specificity, positive and negative predictive values of 73%, 73%, 83%, 53%, and 92% respectively. The mean difference between vFFR and iFA were −0.0484±0.096 and Pearson's correlation coefficient was 0.533 (p<0.001). The ROC area under the curve was 0.839 (0.751–0.928, p<0.001).

Conclusion

FFR were feasible in 94% of cases analysed retrospectively. As compared to gold-standard iFA, vFFR had an overall moderate accuracy in detecting ischemia-producing lesions and a negative predictive value >90%. vFFR has the potential to substantially simplify physiological coronary lesion assessment and thus improve its current uptake.

Funding Acknowledgement

Type of funding sources: None. Bland-Altman plot between vFFR and IFA

Spatial distribution of Toxoplasma gondii in cows and associated risk factors

The aim of the present study was to evaluate the spatial distribution of the prevalence of T. gondii in cows using the indirect immunofluorescence assay and determine associated risk factors. Serum samples were collected from 2970 cows on 263 rural farms in 223 municipalities. A questionnaire was administered to herd owners to collect data for the evaluation of risk factors associated with this disease. Mean seroprevalence of T. gondii in cows was 8.48% (95% CI: 7.48 to 9.49). The microregions with the greatest likelihood (p ≤ 0.05) of having infected animals were Anápolis, Ceres, São Miguel do Araguaia, the Federal District, Anicuns, and Vão do Paraná. The purchase of females or males for reproductive/breeding purposes was significantly associated (p ≤ 0.05) with the prevalence of T. gondii in these regions. A positive correlation (0.7618; p = 0.047) was found between the prevalence of T. gondii and total area in hectares of forests in these regions, suggesting that wild cats may be disseminating T. gondii at these sites. The present results highlight the importance of considering the meat from these animals to be an important infection route for humans who eat raw or undercooked food.

Non Type-1 Brugada pattern, diagnostic yield of 5 ECG criteria in a young adult cohort

Introduction

Distinguishing between non-Type 1 Brugada pattern (non-T1BrP) and an athlete's ECG remains challenging and may have important prognostic implications. We aimed to study prevalence and the diagnostic yield of experts and non-experts for the electrocardiographic non-T1BrP criteria in the young adults from the Sudden Cardiac Death-Screening Of risk factorS (SCD-SOS) cohort.

Methods

We performed a cross-sectional study in which we reviewed 14662 ECGs of SCD-SOS survey participants and selected 2494 that presented a rSr'-pattern in V1-V2. Among these, 98 were classified by experts in hereditary arrhythmic syndromes for the presence of non-T1BrP and by non-experts who performed manual measurements of the diagnostic criteria based on triangle formed by r'-wave. We estimated intra and interobserver concordance for each criterion, and used logistic regression and receiver operating characteristics (ROC) analysis and C-statistics for diagnostic accuracy and definition of the most appropriate cut-off values.

Results

We detected a rSr'-pattern in V1-V2 in 17% of the individuals and found that it was associated with higher PQ and QTc intervals, male gender and lower BMI. The manual measurements of non-T1BrP criteria were reproducible: we had high intraobserver concordance coefficients (CC) ranging from 0.90 to 0.94 (except for d(B) that had 0.66), but interobserver CC were lower (0.45–0.68). The measurements performed were highly correlated with non-T1BrP diagnosis and the criteria with higher discriminatory capacity were the distance d(B) (AUC 0.77; 95% CI0.69–0.84) and the degree of ST-ascent (AUC 0.79; 95% CI 0.72–0.86). The cut-offs defined by other authors had very low sensitivity (8–12%), despite high specificity (98%), so we defined new cut-offs: d(A) ≥2mm, d(B) ≥1.25mm, d(B)/h ≥0.38, β-angle ≥19° and ST-ascent ≥1mm. The addition of the degree of ST-ascent to a model with these 4 parameters presented an increase in C-statistics from 0.77 (95% CI: 0.68–0.86) to 0.83 (95% CI: 0.75–0.91) for the diagnosis of non-T1BrP by an expert in Sudden Arrhythmic Death and Channelopathies.

Conclusion

A rSr'-pattern in precordial leads V1-V2 is a frequent finding and the detection of non-T1BrP by using the aforementioned 5 measurements is reproducible and accurate. In this study, we describe new cut-off values that may help untrained clinicians to identify young individuals who should be referred for provocative drug testing for Brugada Syndrome.

Accuracy of non-T1 BrP criteria

Funding Acknowledgement

Type of funding source: None

Modelling approach to obtain regional respiratory mechanics using electrical impedance tomography and volume-dependent elastance model

OBJECTIVE

This paper presents a method for breath-by-breath estimation of regional respiratory mechanics without the need for special manoeuvres (such as inspiratory pause or low-flow inflation) using electrical impedance tomography (EIT) associated with pressure/airflow waveforms.

APPROACH

We developed a method to estimate regional parameters using the regional impedance fraction, by multiplying it by global flow and volume waveforms. A volume-dependent elastance model was used to obtain compliance, resistance, volume-independent (E ₁), and volume-dependent (E ₂) components. Three swine under invasive mechanical ventilation were used to assess internal consistency and illustrate potential applications of our method. One animal (case 1) was ventilated with a broad range of tidal volumes to compare the consistency between regional and global resistances and compliances. Two other animals (cases 2 and 3) had respiratory compliance decreased, respectively, by overdistension and collapse as quantified by x-ray computed tomography.

MAIN RESULTS

In case 1, derived global estimates obtained from the independent regional estimates were strongly associated with direct measurements of global mechanics (correlation coefficients of 0.9976 and 0.9981 for compliances and resistances, respectively), suggesting consistency of our modelling. In cases 2 and 3, the development of lung overdistension and collapse over time was captured by regional estimates.

CONCLUSIONS

Using EIT and pressure/airflow waveforms, regional respiratory parameters can be obtained cycle-by-cycle, refining lung function monitoring.

SIGNIFICANCE

The method allows real-time monitoring of regional parameters and their trends over time, which might be helpful to differentiate deterioration in lung compliance due to overdistension or collapse.

Long-term use of everolimus in lung transplant patients

Everolimus has been successfully used in solid organ transplantation, especially of the heart and kidney, but much less often in lung transplantation. The aim of this study was to evaluate the efficacy and safety of long-term use of everolimus in lung transplantation in Chile. We retrospectively analyzed patients receiving everolimus between 2005 and 2010 in terms of indication, lung and kidney function, rejection episodes, infections, malignancy appearance, and adverse events. Ten of 60 lung transplant recipients were converted to everolimus (16%) at some point after transplantation: four due to calcineurin inhibitor nephropathy (RD); four bronchiolitis obliterans syndrome (BOS); one lymphoma; and one, graft pulmonary fibrosis. Among patients with RD, at a mean follow-up of 25 months (range = 3-60), renal function remained stable with baseline of 42.7 mL/min and final creatinine clearance of 45.7 mL/min; lung function did not deteriorate. BOS patients, with an average of 30 months' follow-up (range = 12-48), showed baseline forced expiratory volume in the first second of 49% (r: 41-57) without variation in three patients, but with a decrease in another one after 12 months. One patient discontinued everolimus due to intolerance after 1 year. Two patients developed neoplasias: skin cancer and multiple myeloma. There were 14 infection episodes in seven patients, including 10 involving the respiratory tract infections. Only one patient developed dyslipidemia after everolimus initiation. Two patients died: one due to multiple myeloma and another to BOS. There was no rejection episode. Everolimus was effective and safe when used in combination with low doses of calcineurin inhibitor over long-term follow-up of lung transplant patients.

Processing of ovine cardiac valve allografts: 3. Implantation following antimicrobial treatment and preservation

It is known that a satisfactory clinical outcome can follow the implantation of cardiac valve allografts in spite of the loss of living cells in the tissue. If viable cells are not required for long term graft function, then effective disinfection of the tissue might become possible. In an earlier paper in this series we reported that peracetic acid (PAA) is an effective antimicrobial agent for the treatment of valve allografts; it was lethal to the cells but at a concentration of 0.21% had little effect on the mechanical properties or extracellular morphology of the valve leaflets. It was also found that PAA-treatment could be combined with storage in 85% glycerol at 4 degrees C, or cryopreservation with 10% Me(2)SO, without substantial further impairment of microscopic structure or mechanical properties. In this paper we describe the implantation of processed ovine aortic valves in the descending thoracic aorta of sheep. The experimental groups included control untreated valves and valves that had been treated with antibiotics or PAA and either cryopreserved, or stored in 85% glycerol. The recipient sheep showed good clinical appearances until the experiment was terminated at six months. The explanted grafts were examined by standard morphological and mechanical testing methods. The PAA-treated valves were clearly recognisable as valves: the leaflets had fair to medium morphology in both the unpreserved and the cryopreserved groups. All leaflets had a superficial overgrowth of cells. Microsatellite analysis for allelic differences were performed on samples of donor and recipient tissues using three markers of tissue source. Only one valve, which had been treated with PAA, revealed allelic differences between donor and recipient. It is suggested that DNA-fragments may have remained after the destruction of donor cells and six months of implantation: the overgrowing cells were almost certainly of recipient origin. We conclude that our experiments, in which PAA-treatment was combined with preservation, are sufficiently encouraging to justify further studies to refine the technique, but in our opinion they are not sufficient to justify a clinical trial at this time.

BCL10 deletions in haematological malignancies: a cloning artefact?

Mutations within the BCL10 gene, a gene involved in apoptosis, have recently been found to occur in a variety of cancers and it was suggested that BCL10 was involved in the pathogenesis of human malignancies. Our investigations of the involvement of this gene in various malignancies, however, do not uphold this suggestion. We would like to propose that, in fact, the original results were obtained as a result of a rare cloning artefact.

Endocardial and epicardial radiofrequency ablation in the treatment of atrial fibrillation with a new intra-operative device

OBJECTIVE

Atrial fibrillation has been a difficult problem to solve in many surgical patients, especially in those with mitral valve pathology. This study evaluates the results of endocardial and epicardial radiofrequency ablation with a new intra-operative device in the treatment of atrial fibrillation.

METHODS

We operated on 65 patients with atrial fibrillation, 58 of which had concomitant mitral surgery. Atrial fibrillation was chronic (over 1 year) in 46 patients (group A) and paroxysmal or recent onset in 12 (group B). Group C had lone atrial fibrillation (two), concomitant coronary artery disease (four) or a sarcoma (one). Bilateral pulmonary vein isolation with a new intra-operative device was performed through multiple dry lesions in all patients. Groups A and B had endocardial applications at 70 degrees C during 60 s and group C had epicardial applications at 75 degrees C. Three group C patients had epicardial applications off pump. Atrial wall biopsies were performed in nine patients from groups A and B.

RESULTS

There were no serious post-operative complications. At 1 month follow-up 54% of all patients were out of atrial fibrillation and 34% were in normal sinus rhythm with bilateral atrial contraction (Santa Crus Score 4). At 6 months follow-up, in spite of some crossover of patients among groups, similar results were obtained. The success of the procedure was 69% (Santa Crus scores 3 and 4) in mitral patients with a left atrial volume smaller than 200 cm(3). Preliminary data on the transmurality of the lesions is presented. The patients submitted to epicardial radiofrequency ablation (group C) have satisfactory results at 1 month (six out of seven were out of AF).

CONCLUSIONS

Both endocardial and epicardial RF applications are simple and quick to perform and do not pose an additional risk for most patients. Furthermore we believe that it is possible to perform bilateral epicardial radiofrequency ablation of the pulmonary veins without cardiopulmonary bypass. Further refinements of the technique are needed to assure transmurality of all lesions and better results.

Antibiotics are associated with lower relapse rates in outpatients with acute exacerbations of COPD

BACKGROUND

COPD is a complex disease with exacerbations characterized by worsening of symptoms resulting in deteriorating lung function.

STUDY OBJECTIVE

To assess predictive factors of relapse for patients with acute exacerbations of COPD (AECB).

DESIGN

Retrospective cohort analysis of visits for AECB.

SETTING

Veterans Affairs Medical Center.

PATIENTS

Three hundred sixty-two visits (173 patients) with documented COPD treated as outpatients for AECB.

MEASUREMENTS

Severity of underlying COPD, severity of AECB, comorbid conditions, therapy, and relapse rates (return visit within 14 days with persistent or worsening symptoms).

RESULTS

Each visit was analyzed individually (referred to as a patient-visit). One group received antibiotics (270 patient-visits), and the second group (92 patient-visits) did not. Both groups had similar demographics and severity of underlying COPD. The overall relapse rate was 22%. The majority of patient-visits (95%) with severe symptoms at presentation were prescribed antibiotics vs only 40% of those with mild symptoms. Twenty-nine of 92 patient-visits (32%) were followed by relapse in the group that was not given antibiotics, whereas only 50 of 270 (19%) treated with antibiotics relapsed (p < 0.001). Those treated with amoxicillin had an even higher relapse rate (20 of 37 patient-visits, or 54%) than those who did not receive antibiotics (p = 0.006).

CONCLUSIONS

Relapse from AECB was not related to the severity of underlying disease or to the severity of the acute exacerbation. Patients treated with antibiotics had significantly lower relapse rates than those who did not receive antibiotics. However, the specific choice of antibiotic is important because those treated with amoxicillin had the highest relapse rates of all groups.

Adenosine A2A receptors regulate the extracellular accumulation of excitatory amino acids upon metabolic dysfunction in chick cultured retinal cells

The role of endogenous extracellular adenosine as a tonic modulator of the extracellular accumulation of excitatory amino acids (glutamate and aspartate) caused by metabolic inhibition was investigated in cultured retinal cells. The selective adenosine A2A receptor antagonist, 4-[2-[7-amino-2-(2-furyl)(1,2,4)-triazin-5-ylamino]-ethyl]ph enol (ZM241385) (50 nM), increased the release of glutamate (three- to four-fold) and of aspartate (nearly two-fold) upon iodoacetic acid-induced glycolysis inhibition, in the presence or in the absence of Ca2+. Blockade of tonic activation of A2A receptors by ZM241385 also increased (nearly two-fold) the ischemia-induced release of glutamate and aspartate. Furthermore, another selective A2A receptor antagonist, 5-amino-7-(2-phenylethyl)-2-(2-furyl)pyrazolo[4,3-e]-1,2,4-triazolo[1,5- c] pyrimidine (SCH58261), also increased the release of aspartate and glutamate by about two-fold in cells submitted to glycolysis inhibition. In contrast, the selective adenosine A1 receptor antagonist, 1,3-dipropyl-8-cyclopentylxanthine (DPCPX) (100 nM), did not significantly modify the extracellular accumulation of either glutamate or aspartate caused by inducers of chemical ischemia or glycolytic inhibitors. Inhibition of glycolysis also increased (about three-fold) the extracellular accumulation of GABA, which was virtually unchanged by ZM241385. Furthermore, the GABAA receptor antagonist, bicuculline (10 microM), only increased (nearly two-fold) the iodoacetic acid-induced Ca(2+)-dependent release of glutamate, whereas the GABAB receptor antagonist, 3-aminopropyl(diethoxymethyl) phosphinic acid, CGP35348 (100 microM), was devoid of effects on the extracellular accumulation of glutamate and aspartate. These results show that endogenous extracellular adenosine, which rises under conditions of inhibited glycolysis, tonically inhibits the extracellular accumulation of excitatory amino acid through the activation of A2A, but not A1, adenosine receptors, and this effect is independent of GABAA and GABAB functions in the cultured retinal cells.

Pulmonary evaluation and prevalence of non-invasive ventilation in patients with amyotrophic lateral sclerosis: a multicenter survey and proposal of a pulmonary protocol

In order to evaluate the current standard of care for the management of respiratory failure in patients with amyotrophic lateral sclerosis (ALS), a questionaire was mailed to the Medical Directors of 48 multidisciplinary ALS centers in the United States. Twenty centers reported information on 2357 patients, mean of 124 patients per center. Pulmonary function tests were performed at each visit in 17/20 institutions. Arterial blood gases, maximal expiratory pressures and maximal inspiratory pressures were followed in three centers and serum chloride was monitored in only four centers. The use of non-invasive ventilation (NIV) was extremely variable (range 0-50%) and included 360 patients (15%). The majority of centers used symptoms/signs of hypoventilation and worsening forced vital capacity (FVC) to initiate NIV with no established protocol. A FVC between 20 and 40% was used by most centers to initiate NIV. Due to great variability in the approach to monitoring pulmonary function among ALS centers and the modest effects of current medications to slow disease progression, we propose the use of a structured protocol which can prospectively study the role of NIV in prolonging survival and improving quality of life.

No evidence of chaos in the heart rate variability of normal and cardiac transplant human subjects

INTRODUCTION

The variability observed in the heart rate may reflect fundamental aspects of cardiac activity. It has been under discussion whether heart rate variability (HRV) is due to noise or chaos, which is irregular behavior occurring in deterministic nonlinear systems.

METHODS AND RESULTS

Using chaos analysis techniques, we analyzed HRV of five normal and five human cardiac transplant subjects at rest. HRV is studied using the beat-to-beat RR interval time series extracted from the ECG. The cardiac transplant subjects exhibited a much smaller HRV than the normal subjects because of heart denervation. We present the map and correlation dimension estimation for the RR time series. To test for nonlinear correlations in the dynamics, we built surrogate time series that have the same power spectra as the experimental time series, but also have randomized phases. The experimental and the surrogate data were compared using the correlation integral. No correlation dimension was found for the RR time series of either the normal or the cardiac transplant subjects. Nevertheless, nonlinear correlations were detected in the HRV of the normal subjects but not in HRV of the cardiac transplant subjects. For the latter, no significant changes were observed in the correlation integral as a function of time after transplantation.

CONCLUSION

We found no evidence of low-dimensional chaos in the HRV of normal and cardiac transplant subjects. However, some nonlinear correlations were detected in the HRV of the normal subjects, which may be associated with autonomic nervous system influence.

Electrosurgical treatment of atrial fibrillation with a new intraoperative radiofrequency ablation catheter

BACKGROUND

To assess the efficacy of a new catheter for intraoperative radiofrequency ablation.

METHODS

We operated 35 mitral patients with atrial fibrillation of which 27 had chronic atrial fibrillation with a mean duration of 8 +/- 6 years. Most patients were in functional class III or IV. All patients were operated under cardiopulmonary bypass using sternotomy in 29 patients, right thoracotomy in 5 and left thoracotomy in 1.

RESULTS

Bilateral pulmonary vein isolation with radiofrequency catheter ablation was achieved in 7 +/- 4 minutes. There was no mortality or morbidity. Out of the 27 patients with one to three months follow-up 60% were out of atrial fibrillation and 48% had both atria contracting (scores 3 and 4). A longer time is required to assess the end result of these techniques, because the complete healing of the ablation lesions takes 3 to 6 months.

CONCLUSIONS

We conclude that with appropriate tools and settings the use of intraoperative radiofrequency catheter ablation is fast, safe and effective. Its indications can be extended to other types of atrial fibrillation patients.

Modelling a parasystolic rhythm in a heart-transplant patient

A parasystole from a heart-transplant patient is analysed using a beat-to-beat RR interval time series obtained from an electrocardiogram (ECG). The dysrhythmia, resulting from the co-existence of two pacemakers, the sinus node and an ectopic focus, presents distinctive regular patterns, with transitions from one pattern to another occurring abruptly. It is shown that the parasystolic rhythm can be simulated by a model involving two oscillators firing at fixed rates, under the restriction that neither is allowed to fire during the other's refractory period. It is found that the structure of the generated RR time series is essentially determined by the ratio of the periods of the two oscillators. In the case of a heart-transplant patient with a small heart-rate variability as a result of heart denervation, the model predicts the RR intervals with an error of less than 6% for an 80-beat sequence. From a physiological point of view, the results imply that the interaction between the two pacemakers in the heart is fairly weak, and hence the parasystole observed in the heart-transplant patient can be modelled as pure parasystole.

Surgery for atrial fibrillation using radiofrequency catheter ablation: assessment of results at one year

OBJECTIVE

The results obtained in 43 patients using direct intraoperative radiofrequency catheter ablation, as an alternative to surgical incisions, to perform atrial fibrillation surgery, are presented.

METHODS

Forty-three patients with ages ranging from 43 to 74 years (x = 59), with chronic atrial fibrillation with an average duration 6+/-5 years were operated. Eleven patients suffered from clinically relevant tachyarrythmia and eight had previous thromboembolic events. All but one patient had concomitant mitral valve surgery. Direct intraoperative radiofrequency catheter ablation was used to perform endocardial bilateral isolation of the pulmonary veins from the left atrium.

RESULTS

There were no local or general complications, namely bleeding or thromboembolic events. Of the 33 patients with more than 3 months of follow-up, 36% remained in atrial fibrillation (Santa Cruz score 0); 30% had Score 4; 18% had Score 3; 6% had Score 2; 9% had Score 1.

CONCLUSIONS

We conclude that the use of intraoperative radiofrequency catheter ablation is fast and safe. Presently, this is our method of choice for surgical treatment of atrial fibrillation in mitral patients.

Acute respiratory distress syndrome. Liquid ventilation

In summary, the use of partial liquid ventilation with perfluorocarbon seems to be safe in neonates, children, and adults with ALI or ARDS. Partial liquid ventilation can be used for the following goals: recruitment of lung volume; enhancement or uniformity of lung inflation; improved oxygenation; improved lung compliance; and prevention or minimization of lung damage induced by mechanical ventilation. Partial liquid ventilation improved gas exchange and lung mechanics in test subjects. Cardiopulmonary interaction and long-term safety require further study. Extrapolations from animal data, however, suggest that there are no long-term undesired effects. The current clinical data strongly suggest that close monitoring and adjustment of ventilator parameters during drug instillation are necessary to reduce hypoxia, bradycardia, and pneumothorax. Further studies are required to explore the efficacy of partial liquid ventilation with perfluorocarbon in ALI or ARDS subjects, in particular, to evaluate the safety and efficacy of smaller doses; mechanical ventilation strategies; and outcomes. Additional research including large randomized studies is clearly required to answer these and other questions.

[Prevalence of dyslipidemias in adult ambulatory laboratory tests from different health care providers]

OBJECTIVE

To detect differences in the prevalence of dyslipidemia in adult ambulatory laboratory tests from three different health care providers, in Salvador-Brazil, 1995.

METHODS

The study was carried out using a probabilistic sample of 24 out of 104 laboratories (approximately equal to 25%) which performed the same enzymatic method for lipid tests with the same quality control. Laboratory tests results were separated into three groups, according to health care provider: Sistema Unico de Saúde (SUS, governamental), Health Maintenance Organizations (HMO), and Private or Patients Health Insurance (PHI). Criteria for dyslipidemias in mg/dl were: total cholesterol > or = 240; LDL-c > or = 160; HDL-c < 35 and triglycerides > or = 200. Prevalence rates, 95% confidence intervals (CI) and chi (2) test were used in the analysis.

RESULTS

From the 5464 adult subjects, 14.8% were from SUS, 31.6%. from HMO and 53.6% PHI. The highest prevalence for hypercholesterolemia--28.0% (CI 24.0; 32.0) and for LDL-c > or = 160mg/dL--30.4% (CI 27.6; 33.2), were found in the HMO group. PHI had the highest prevalence for HDL-c < 35mg/dL--12.3% (CI 10.0; 13.8), and for hypertrygliceridemia--17.8% (CI 16.3; 19.3). Most of the differences among health providers were statistically significant.

CONCLUSION

The best lypid profile observed in subjects from SUS suggests social differences in the prevalence of dyslipidemias. As compared to other dyslipidemias, HDL-c < 35mg/dL prevalence was lower than expected in all three groups. The data may provide insights to medical doctors and other health care professionals regarding the questions of dyslipidemias. It can also provide objective information to the patients and encourage them to change their life styles.

[Prevalence of dyslipidemias in adults in laboratory tests from Salvador, Brazil]

PURPOSE

To determine the prevalence of dyslipidemia in non-hospital laboratory tests of adults from Salvador, Brazil.

METHODS

The study was carried out in subjects from a probabilistic sample of 25% of a total of 104 local laboratories that used the same enzymatic method for lipid analysis with the quality control as recommended by the Brazilian Society of Clinical Analyses. These represented 93% of all non-hospital laboratories of Salvador in 1995. The odd months of 1995 were selected for sampling in the present study. Criteria for dyslipidemias were: total cholesterol > or = 240; LDL > or = 160; HDL < 35 and triglycerides > or = 200 mg/dl. Prevalence rates and their 95% confidence intervals (CI) and chi 2 test were used in the analyses.

RESULTS

Tests from two of the 26 laboratories were not used in the analyses due to file problems or refusal. 7,392 adults were screened, 65% female. We observed prevalence (95% CI) of hypercholesterolemia in 30.0 (27.8; 32.2)%, high LDL in 30.1 (30.8; 35.4)% and hypertriglyceridemia in 30.4 (29.0; 31.4)% of the females. As to the male subjects, prevalences were; 24.0 (20.5; 27.5)% for hypercholesterolemia, 26.1 (22.4; 29.3)% for high LDL, 27.6 (25.7; 29.5)% for hypertriglyceridemia. All gender differences were significant. Low HDL occurred in 15.9 (14.2; 17.8)% of males and in 8.0 (7.1; 8.9)% of females.

CONCLUSION

Dyslipidemia is an important risk factor observed in non-hospital laboratory tests of men and women in Salvador. Our data may provide physicians and other health care professionals with objective information to encourage life-style changes.

Longstanding traumatic tricuspid regurgitation with severe right ventricular failure

A very unusual case of traumatic tricuspid regurgitation is reported, with severe symptoms of right ventricular failure, extreme dilatation of the right heart, echocardiographic and angiographic criteria of major tricuspid regurgitation, and severe right ventricular systolic dysfunction. The patient was referred for heart transplantation, on the assumption that conventional surgery was not possible. After careful evaluation, as the patient had normal pulmonary artery pressure and resistance, a tricuspid valve was replaced with good surgical outcome.

Pontocerebellar hypoplasia with microcephaly and dyskinesia: report of two cases

We present two clinically diagnosed cases of pontocerebellar hypoplasia with microcephaly and dyskinesia (pontocerebellar hypoplasia type 2) from two different Portuguese families. Both children presented neurological involvement from birth, progressive microcephaly, exuberant chorea and dystonia, myoclonic jerks, pontocerebellar hypoplasia, and progressive cerebral cortical atrophy. One child had consanguineous parents.

New insights in biology and current therapeutic options for patients with chronic myelogenous leukemia

BACKGROUND AND OBJECTIVE

From the discovery of the Ph-chromosome, there has been an extraordinary progress in our understanding of chronic myeloid leukemia (CML). During the last three decades, new findings arising from dissection of the genetic abnormalities at a molecular level have received the most attention, but there have also been important new observations arising from studies of the biologic behaviour of normal and leukemic stem cells and, more recently, from clinical investigations. In this review we first report the most important observations relevant to understanding the oncogenic potential of the BCR-ABL chimeric gene, and the behaviour and the relationships of normal and leukemic stem cells. From a clinical point of view, allogeneic stem cell transplantation is the only procedure able to cure CML. The main issues are: who can receive this procedure, and when and how it can be given. The situation is more complex in unrelated transplants. In patients without HLA compatible donors, many large trials in different countries have demonstrated that interferon alpha therapy is indicated and effective in the majority of patients. On the other hand, autologous stem cell transplantation is still an experimental procedure. These aspects will be analyzed in detail and, at the end, a therapeutic algorithm of a possible approach to the patients with untreated CML is provided.

EVIDENCE AND INFORMATION SOURCES

The method used for preparing this review was an informal consensus development. All the authors of the present review have been working in the field of chronic myeloid leukemia, and have contributed original papers in peer-reviewed journals. In addition, the material examined in the present review includes articles and abstracts published in journals covered by the Science Citation Index and Medline.

STATE OF ART AND PERSPECTIVES

The oncogenic potential of BCR-ABL has been demonstrated in a number of in vitro and in vivo model systems. Current research efforts are focused on defining the mechanism by which BCR-ABL transforms primary hematopoietic cells. The fact that BCR-ABL contains tyrosine residues, an SH2 domain, an SH3 domain, and proline-rich sequences raises the possibility of multiple protein-protein interactions. Indeed, BCR-ABL is reported to bind and/or phosphorylate more than 20 proteins. The insights into the signal transduction pathways activated by BCR-ABL will hopefully provide a new basis for the treatment of CML patients. Clinical evidence of the existence of a transplantable CML stem cell population has recently been extended to xenogeneic recipients of transplanted CML cells and by retroviral marking to autograft recipients. The potential of using immunodeficient mice as recipients of CML stem cells to create an in vivo model of chronic phase CML should be invaluable for testing novel therapies designed to eliminate residual disease in the patient. Current therapeutic options include conventional chemotherapy, IFN-a and allogeneic stem cell transplantation as established procedures, and autografting as an experimental procedure. While IFN-a as a first line therapy does not seem to jeopardize further treatments, autografting, according to the Genoa approach or other procedures, i.e. Ph-positive cells collected at diagnosis without mobilization therapy, raises the question of an ideal sequential strategy in the management of CML patients. There seems to be a general agreement that a patient less than 50 years old, with an HLA identical sibling, should receive an allogeneic stem cell transplant. This approach should be offered also to younger patients (< or = 40 years) who are able to find an unrelated matched donor. Since it seems that the normal hematopoietic reservoir declines with time, it may be desiderable to mobilize and collect peripheral stem cells in order to store Ph-negative progenitors as soon after diagnosis as possible when the WBC count has been controlled by hydroxyurea while searchin

L-2-Hydroxyglutaric aciduria: clinical, biochemical and magnetic resonance imaging in six Portuguese pediatric patients

We present clinical, biochemical and cranial magnetic resonance imaging data of six pediatric patients with L-2-hydroxyglutaric aciduria. All the children have the same ethic origin and lived in the northern area of Portugal. Our findings reinforce the described phenotype of this rare metabolic disease with mental deficiency, severe cerebellar dysfunction, mild extrapyramidal and pyramidal symptoms, progressive macrocephaly and seizures. Magnetic resonance imaging revealed subcortical leukoencephalopathy, cerebellar atrophy and signal changes in the putamina and dentate nuclei. These were similar to those of the previous reports in all patients. The urinary excretion of L-2-hydroxyglutaric acid was variably increased in all patients. The other persistent biochemical abnormality was hyperlysinemia. We have found a strong correlation between the severity of the clinical manifestations and the extension of the lesions in the neuroimaging studies. There was no correlation between the clinical findings and the amount of urinary excretion of L-2-hydroxyglutaric acid. We report the second case in the literature of a cerebral thalamic tumor in L-2-hydroxyglutaric aciduria; neuropathological examination of the surgical biopsy demonstrated a diffuse fibrillary astrocytoma.

Manometric study of the upper esophageal sphincter before and after endoscopic management of Zenker's diverticulum

BACKGROUND/AIM

Zenker's diverticulum treatment was done by endoscopic management of the elderly and debilitated patients without general anesthesia.

MATERIALS/METHODS

With this technique, the septum between the diverticulum and the esophageal lumen is sectioned with a diathermic knife. Since the upper esophageal sphincter (UES) is certainly included in the mass sectioned, this accounts for the success of the procedure.

RESULTS

Manometric assessment of the UES was done in 5 patients before the endoscopic treatment. The mean pressure was 54.6 cm H2O and the mean length of 3 cm. A significant (p < 0.05) reduction in maximum pressure occurred postoperatively--mean 26.8 cm H2O. There was no significant variation in length of the UES.

CONCLUSION

The maintenance of this basal pressure may be explained by the preservation of the circular muscle structure of the region, with sphincter-like characteristics.