Diagnostic accuracy of research criteria for prodromal frontotemporal dementia

BACKGROUND

The Genetic Frontotemporal Initiative Staging Group has proposed clinical criteria for the diagnosis of prodromal frontotemporal dementia (FTD), termed mild cognitive and/or behavioral and/or motor impairment (MCBMI). The objective of the study was to validate the proposed research criteria for MCBMI-FTD in a cohort of genetically confirmed FTD cases against healthy controls.

METHODS

A total of 398 participants were enrolled, 117 of whom were carriers of an FTD pathogenic variant with mild clinical symptoms, while 281 were non-carrier family members (healthy controls (HC)). A subgroup of patients underwent blood neurofilament light (NfL) levels and anterior cingulate atrophy assessment.

RESULTS

The core clinical criteria correctly classified MCBMI vs HC with an AUC of 0.79 (p < 0.001), while the addition of either blood NfL or anterior cingulate atrophy significantly increased the AUC to 0.84 and 0.82, respectively (p < 0.001). The addition of both markers further increased the AUC to 0.90 (p < 0.001).

CONCLUSIONS

The proposed MCBMI criteria showed very good classification accuracy for identifying the prodromal stage of FTD.

Longitudinal Cognitive Changes in Genetic Frontotemporal Dementia Within the GENFI Cohort

BACKGROUND AND OBJECTIVES

Disease-modifying therapeutic trials for genetic frontotemporal dementia (FTD) are underway, but sensitive cognitive outcome measures are lacking. The aim of this study was to identify such cognitive tests in early stage FTD by investigating cognitive decline in a large cohort of genetic FTD pathogenic variant carriers and by investigating whether gene-specific differences are moderated by disease stage (asymptomatic, prodromal, and symptomatic).

METHODS

C9orf72, GRN, and MAPT pathogenic variant carriers as well as controls underwent a yearly neuropsychological assessment covering 8 cognitive domains as part of the Genetic FTD Initiative, a prospective multicenter cohort study. Pathogenic variant carriers were stratified according to disease stage using the global Clinical Dementia Rating (CDR) plus National Alzheimer's Coordinating Center (NACC) FTLD score (0, 0.5, or ≥1). Linear mixed-effects models were used to investigate differences between genetic groups and disease stages as well as the 3-way interaction between time, genetic group, and disease stage.

RESULTS

A total of 207 C9orf72, 206 GRN, and 86 MAPT pathogenic variant carriers and 255 controls were included. C9orf72 pathogenic variant carriers performed lower on attention, executive function, and verbal fluency from CDR plus NACC FTLD 0 onwards, with relatively minimal decline over time regardless of the CDR plus NACC FTLD score (i.e., disease progression). The cognitive profile in MAPT pathogenic variant carriers was characterized by lower memory performance at CDR plus NACC FTLD 0.5, with decline over time in language from the CDR plus NACC FTLD 0.5 stage onwards, and executive dysfunction rapidly developing at CDR plus NACC FTLD ≥1. GRN pathogenic variant carriers declined on verbal fluency and visuoconstruction in the CDR plus NACC FTLD 0.5 stage, with progressive decline in other cognitive domains starting at CDR plus NACC FTLD ≥1.

DISCUSSION

We confirmed cognitive decline in the asymptomatic and prodromal stage of genetic FTD. Specifically, tests for attention, executive function, language, and memory showed clear differences between genetic groups and controls at baseline, but the speed of change over time differed depending on genetic group and disease stage. This confirms the value of neuropsychological assessment in tracking clinical onset and progression and could inform clinical trials in selecting sensitive end points for measuring treatment effects as well as characterizing the best time window for starting treatment.

Optimization of a Quantitative PCR Methodology for Detection of Aspergillus spp. and Rhizopus arrhizus

Introduction

Multiplex quantitative polymerase chain reaction (qPCR) methods for the detection of Aspergillus spp. based only on SYBR Green and melting curve analysis of PCR products are difficult to develop because most targets are located within ITS regions. The aim of this study was to adapt our previously developed methodology based on a multiplex PCR assay coupled with GeneScan analysis to provide a qPCR method.

Methods

A SYBR Green-based real-time PCR assay was optimized to detect A. fumigatus, A. flavus, A. niger, A. terreus, and R. arrhizus in a multiplex assay and applied to cultured fungi and spiked plasma.

Results

Different melting temperatures allowed identification of all five pathogens and discrimination between them, even in samples with low amounts of fungal gDNA (from 1.3 to 33.0 pg/μL), which has been reported previously as problematic. No false-positive results were obtained for non-target species, including bacteria and human DNA. This method allowed detection of fungal pathogens in human plasma spiked with fungal DNA and in coinfections of A. niger/R. arrhizus.

Discussion

This work provides evidence for the use of a qPCR multiplex method based on SYBR Green and melting curve analysis of PCR products for the detection of A. fumigatus, A. flavus, A. niger, A. terreus, and R. arrhizus. The proposed method is simpler and less expensive than available kits based on fluorescent probes and can be used for aiding diagnosis of the most relevant invasive filamentous fungi, particularly in low-income health care institutions.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40291-022-00595-1.

Fungal infections diagnosis - Past, present and future

Despite the scientific advances observed in the recent decades and the emergence of new methodologies, the diagnosis of systemic fungal infections persists as a problematic issue. Fungal cultivation, the standard method that allows a proven diagnosis, has numerous disadvantages, as low sensitivity (only 50% of the patients present positive fungal cultures), and long growth time. These are factors that delay the patient's treatment and, consequently, lead to higher hospital costs. To improve the accuracy and quickness of fungal infections diagnosis, several new methodologies attempt to be implemented in clinical microbiology laboratories. Most of these innovative methods are independent of pathogen isolation, which means that the diagnosis goes from being considered proven to probable. In spite of the advantage of being culture-independent, the majority of the methods lack standardization. PCR-based methods are becoming more and more commonly used, which has earned them an important place in hospital laboratories. This can be perceived now, as PCR-based methodologies have proved to be an essential tool fighting against the COVID-19 pandemic. This review aims to go through the main steps of the diagnosis for systemic fungal infection, from diagnostic classifications, through methodologies considered as "gold standard", to the molecular methods currently used, and finally mentioning some of the more futuristic approaches.

Use of mild cognitive impairment and prodromal AD/MCI due to AD in clinical care: a European survey

Introduction

The diagnosis of mild cognitive impairment (MCI) refers to cognitive impairment not meeting dementia criteria. A survey among members of the American Association of Neurology (AAN) showed that MCI was considered a useful diagnosis. Recently, research criteria have been proposed for the diagnosis of Alzheimer’s disease (AD) in MCI based on AD biomarkers (prodromal AD/MCI due to AD). The aim of this study was to investigate the attitudes of clinicians in Europe on the clinical utility of MCI and prodromal AD/MCI due to AD criteria. We also investigated whether the prodromal AD/MCI due to AD criteria impacted management of MCI patients.

Methods

An online survey was performed in 2015 among 102 members of the European Academy of Neurology (EAN) and the European Alzheimer’s Disease Consortium (EADC). Questions were asked on how often criteria were used, how they were operationalized, how they changed patient management, and what were considered advantages and limitations of MCI and prodromal AD/MCI due to AD. The questionnaire consisted of 47 questions scored on a Likert scale.

Results

Almost all respondents (92%) used the MCI diagnosis in clinical practice. Over 80% of the EAN/EADC respondents found a MCI diagnosis useful because it helped to label the cognitive problem, involve patients in planning for the future, and start risk reduction activities. These findings were similar to those reported in the AAN survey. Research criteria for prodromal AD/MCI due to AD were used by 68% of the EAN/EADC respondents. The most common reasons to use the criteria were increased certainty of diagnosis (86%), increased possibilities to provide counseling (51%), facilitation of follow-up planning (48%), start of medical intervention (49%), and response to patients’ wish for a diagnosis (41%). Over 70% of the physicians considered that a diagnosis of prodromal AD/MCI due to AD had an added value over the MCI diagnosis.

Conclusions

The diagnostic criteria of MCI and prodromal AD/MCI due to AD are commonly used among EAN/EADC members. The prodromal AD/MCI due to AD were considered clinically useful and impacted patient management and communication.

Electronic supplementary material

The online version of this article (10.1186/s13195-019-0525-9) contains supplementary material, which is available to authorized users.

Functional network resilience to pathology in presymptomatic genetic frontotemporal dementia

The presymptomatic phase of neurodegenerative diseases are characterized by structural brain changes without significant clinical features. We set out to investigate the contribution of functional network resilience to preserved cognition in presymptomatic genetic frontotemporal dementia. We studied 172 people from families carrying genetic abnormalities in C9orf72, MAPT, or PGRN. Networks were extracted from functional MRI data and assessed using graph theoretical analysis. We found that despite loss of both brain volume and functional connections, there is maintenance of an efficient topological organization of the brain's functional network in the years leading up to the estimated age of frontotemporal dementia symptom onset. After this point, functional network efficiency declines markedly. Reduction in connectedness was most marked in highly connected hub regions. Measures of topological efficiency of the brain's functional network and organization predicted cognitive dysfunction in domains related to symptomatic frontotemporal dementia and connectivity correlated with brain volume loss in frontotemporal dementia. We propose that maintaining the efficient organization of the brain's functional network supports cognitive health even as atrophy and connectivity decline presymptomatically.

Variation in Venoms of Polybia Paulista Von Ihering and Polybia Occidentalis Olivier (Hymenoptera: Vespidae), Assessed by the FTIR-PAS Technique

Wasps are able to synthesize toxic compounds known as venoms, which form a part of a mechanism to overcome prey and also to defend their colonies. Study of the compounds that constitute these substances is essential in order to understand how this defense mechanism evolved, since there is evidence that the venoms can vary both intra- and interspecifically. Some studies have used liquid and gas chromatography as a reliable technique to analyze these compounds. However, the use of Fourier transform infrared photoacoustic spectroscopy (FTIR-PAS) to analyze the variations in venom's chemical profile has been proposed recently. This study evaluated whether the FTIR-PAS technique is effective for assessing the role of environmental factors on intra- and interspecific differences in the venom of the wasps Polybia paulista Von Ihering and Polybia occidentalis Olivier by FTIR-PAS. The colonies were collected in three municipalities of Mato Grosso do Sul, Brazil, in different types of environments. The results showed that the venoms of P. paulista and P. occidentalis differed significantly in profile. In addition, the intraspecific differences in the venom's chemical profile of P. paulista are related to the type of environment where they nested, regardless of the geographical distance between the nests. The FTIR-PAS technique proved to be reliable and effective to evaluate the variations in the venom's chemical profile in social wasps.

Integrative biomarker discovery in neurodegenerative diseases

Data mining has been widely applied in biomarker discovery resulting in significant findings of different clinical and biological biomarkers. With developments in technology, from genomics to proteomics analysis, a deluge of data has become available, as well as standardized data repositories. Nonetheless, researchers are still facing important challenges in analyzing the data, especially when considering the complexity of pathways involved in biological processes and diseases. Data from single sources appear unable to explain complex processes, such as those involved in brain-related disorders, including Alzheimer's disease, Parkinson's disease and amyotrophic lateral sclerosis, thus raising the need for a more comprehensive perspective. A possible solution relies on data and model integration, where several data types are combined to provide complementary views. This in turn can result in the discovery of previously unknown biomarkers by unraveling otherwise hidden relationships between data from different sources, and/or validate such composite biomarkers in more powerful predictive models.

Coexistence of tuberculosis and mammary carcinoma in a goat

Synchronic occurrence of tuberculosis mastitis and mammary cancer is rare in humans and, to the best of our knowledge, not reported in domestic animals. Here, we present a case of a female adult goat of Serrana breed with simultaneous occurrence of a granulomatous mastitis, due to Mycobacterium caprae, and a mammary carcinoma. Both pathological conditions are rare in goats and should be included in differential diagnosis of mammary lesions.

Nucleic acid and protein extraction from electropermeabilized E. coli cells on a microfluidic chip

Due to the extensive use of nucleic acid and protein analysis of bacterial samples, there is a need for simple and rapid extraction protocols for both plasmid DNA and RNA molecules as well as reporter proteins like the green fluorescent protein (GFP). In this report, an electropermeability technique has been developed which is based on exposing E. coli cells to low voltages to allow extraction of nucleic acids and proteins. The flow-through electropermeability chip used consists of a microfluidic channel with integrated gold electrodes that promote cell envelope channel formation at low applied voltages. This will allow small biomolecules with diameters less than 30 A to rapidly diffuse from the permeabilized cells to the surrounding solution. By controlling the applied voltage, partial and transient to complete cell opening can be obtained. By using DC voltages below 0.5 V, cell lysis can be avoided and the transiently formed pores can be closed again and the cells survive. This method has been used to extract RNA and GFP molecules under conditions of electropermeability. Plasmid DNA could be recovered when the applied voltage was increased to 2 V, thus causing complete cell lysis.

EuroFlow standardization of flow cytometer instrument settings and immunophenotyping protocols

The EU-supported EuroFlow Consortium aimed at innovation and standardization of immunophenotyping for diagnosis and classification of hematological malignancies by introducing 8-color flow cytometry with fully standardized laboratory procedures and antibody panels in order to achieve maximally comparable results among different laboratories. This required the selection of optimal combinations of compatible fluorochromes and the design and evaluation of adequate standard operating procedures (SOPs) for instrument setup, fluorescence compensation and sample preparation. Additionally, we developed software tools for the evaluation of individual antibody reagents and antibody panels. Each section describes what has been evaluated experimentally versus adopted based on existing data and experience. Multicentric evaluation demonstrated high levels of reproducibility based on strict implementation of the EuroFlow SOPs and antibody panels. Overall, the 6 years of extensive collaborative experiments and the analysis of hundreds of cell samples of patients and healthy controls in the EuroFlow centers have provided for the first time laboratory protocols and software tools for fully standardized 8-color flow cytometric immunophenotyping of normal and malignant leukocytes in bone marrow and blood; this has yielded highly comparable data sets, which can be integrated in a single database.

EuroFlow antibody panels for standardized n-dimensional flow cytometric immunophenotyping of normal, reactive and malignant leukocytes

Most consensus leukemia & lymphoma antibody panels consist of lists of markers based on expert opinions, but they have not been validated. Here we present the validated EuroFlow 8-color antibody panels for immunophenotyping of hematological malignancies. The single-tube screening panels and multi-tube classification panels fit into the EuroFlow diagnostic algorithm with entries defined by clinical and laboratory parameters. The panels were constructed in 2-7 sequential design-evaluation-redesign rounds, using novel Infinicyt software tools for multivariate data analysis. Two groups of markers are combined in each 8-color tube: (i) backbone markers to identify distinct cell populations in a sample, and (ii) markers for characterization of specific cell populations. In multi-tube panels, the backbone markers were optimally placed at the same fluorochrome position in every tube, to provide identical multidimensional localization of the target cell population(s). The characterization markers were positioned according to the diagnostic utility of the combined markers. Each proposed antibody combination was tested against reference databases of normal and malignant cells from healthy subjects and WHO-based disease entities, respectively. The EuroFlow studies resulted in validated and flexible 8-color antibody panels for multidimensional identification and characterization of normal and aberrant cells, optimally suited for immunophenotypic screening and classification of hematological malignancies.

Flow cytometric immunobead assay for the detection of BCR-ABL fusion proteins in leukemia patients

BCR-ABL fusion proteins show increased signaling through their ABL tyrosine kinase domain, which can be blocked by specific inhibitors, thereby providing effective treatment. This makes detection of BCR-ABL aberrations of utmost importance for diagnosis, classification and treatment of leukemia patients. BCR-ABL aberrations are currently detected by karyotyping, fluorescence in situ hybridization (FISH) or PCR techniques, which are time consuming and require specialized facilities. We developed a simple flow cytometric immunobead assay for detection of BCR-ABL fusion proteins in cell lysates, using a bead-bound anti-BCR catching antibody and a fluorochrome-conjugated anti-ABL detection antibody. We noticed protein stability problems in lysates caused by proteases from mature myeloid cells. This problem could largely be solved by adding protease inhibitors in several steps of the immunobead assay. Testing of 145 patient samples showed fully concordant results between the BCR-ABL immunobead assay and reverse transcriptase PCR of fusion gene transcripts. Dilution experiments with BCR-ABL positive cell lines revealed sensitivities of at least 1%. We conclude that the BCR-ABL immunobead assay detects all types of BCR-ABL proteins in leukemic cells with high specificity and sensitivity. The assay does not need specialized laboratory facilities other than a flow cytometer, provides results within approximately 4 h, and can be run in parallel to routine immunophenotyping.

Fluorescence and DOC contents of estuarine pore waters from colonized and non-colonized sediments: effects of sampling preservation

The influence of the colonization of salt marsh sediments with Halimione portulacoides was evaluated by analysing the fluorescent dissolved organic matter (FDOM) in sediment pore waters from a salt marsh at different depths. Cores of sediments at colonized and non-colonized sites were collected from a coastal lagoon (Ria de Aveiro, Portugal). The DOC content of extracted pore waters was determined and characterized by synchronous molecular fluorescence (Deltalambda=60nm) and UV-visible spectroscopies. The common practice of freezing sediment cores for further and later chemical investigation was shown not to be an appropriate methodology of sample preservation. On the contrary, freezing of extracted and filtered pore water seemed not to affect either the DOC content or the fluorescence properties of pore waters. Two types of fluorescent substances were found in the pore waters spectra; one corresponding to humic-like substances and another one resembling proteins. However, major differences were found in the spectra of pore waters depending on both depth and the presence/absence of vegetation colonization.

Casein Breakdown in Terrincho Ovine Cheese: Comparison with Bovine Cheese and with Bovine/Ovine Cheeses

Terrincho cheese is an uncooked, pressed cheese made from raw whole ovine milk from the "Churra da Terra Quente" breed. It requires a minimum ripening time of 30 d. A detailed evaluation of the effect of ripening time on the breakdown of the casein fractions, along with the formation of major breakdown products of casein hydrolysis, was monitored by HPLC to contribute to a more complete characterization of this product. In 30-d-old cheeses, only 20% of alpha(S1)-casein remained intact; the beta-casein fraction was more resistant to hydrolysis. The ripening time of Terrincho cheese can be predicted using 2 variables of normalized peak areas of alpha(S1)-casein and alpha(S1)-I peptide, and a constant; the estimation error is 2.5 d. The pH 4.3-insoluble fraction of Terrincho and cheeses manufactured with bovine milk and with ovine milk combined with 2 levels of bovine milk (10 and 20%) revealed different chromatographic and electrophoretic profiles, especially the alpha(S1)-casein fraction. Similar proteolysis progress was observed, particularly in the percentage of casein fraction degradation. However, using both analytical methods, the detection of 10% bovine milk at 30 d of ripening was no longer possible as result of alpha(S1)-casein hydrolysis. The discriminate analysis applied to HPLC data indicated that at 30 d of ripening, differences between the casein fractions of Terrincho cheese and mixture cheeses were mainly from beta1-casein content. The function thus obtained was able to correctly classify all the samples according to cheese type. Using the descriptive sensory profile, Terrincho cheese at 30 d of ripening could be distinguished from bovine and mixture cheeses owing to its higher fracturability and adhesiveness and lower elasticity and hardness, which correlated with its lower total casein content.

Kindling induces a long-term enhancement in the density of N-type calcium channels in the rat hippocampus

How seizures arise and recur in epilepsy is unknown. Recent genetic, pharmacological and electrophysiological data indicate a significant but undisclosed role for voltage-dependent calcium channels. Since the contribution such channels make to nerve function reflects the targeting of discrete subtypes to distinct cellular regions, we hypothesized that epilepsy reflects alterations in their spatiotemporal patterns of expression at the cell surface. To test this possibility, we examined the expression and distribution of hippocampal N-type calcium channels in an animal seizure model: kindling. Confocal microscopy of N-type calcium channels labeled with a new fluorescent ligand, coupled with a novel technique for analysing multiple images, revealed a 20-40% increase in their expression in CA1 and CA3 within 24 h post-seizure. These increases persisted in the dendritic fields of CA1, but had dissipated in CA3 by 28 days post-seizure. Such changes correlate poorly with cell number or synaptogenesis, but are consistent with increased N-type calcium channel expression on presynaptic terminals or, more likely, dendrites. These data rationalize recent electrophysiology and in situ hybridization data, and suggest that kindling alters N-type calcium channel trafficking mechanisms to cause a persistent, local, remodeling of their distributions in CA1 dendrites. The persistent induction of N-type calcium channels may be part of a mechanism for, and a hallmark of, synaptic plasticity, in which kindling represents a reinforcement of synapses en masse.

Ketamine and phenobarbital do not reduce the evoked-potential enhancement induced by electroconvulsive shock seizures in the rat

Electroconvulsive shock (ECS) seizures provide an animal analog of electroconvulsive therapy (ECT). Repeated ECS seizures cause a long-lasting, and perhaps permanent, enhancement of entorhinal-dentate evoked potentials (EPs) in the rat. Recently it has been reported that ketamine protects against ECS-induced EP enhancement. The present study was designed to replicate these findings and to extend them by incorporating a phenobarbital group (to control for ketamine's partial diminution of seizures) and an animal test of antidepressant activity (the Porsolt test). Unexpectedly, we found that neither ketamine nor phenobarbital protected against ECS-induced enhancement of EPs. Both, however, diminished the 'therapeutic' effects of ECS, as modeled by the Porsolt test. These data suggest that the use of ketamine would not eliminate the unwanted effects of ECT and that it might diminish ECT's therapeutic benefits.

The use of maximum SOFA score to quantify organ dysfunction/failure in intensive care. Results of a prospective, multicentre study. Working Group on Sepsis related Problems of the ESICM

OBJECTIVE

To evaluate the performance of total maximum sequential organ failure assessment (SOFA) score and a derived measure, delta SOFA (total maximum SOFA score minus admission total SOFA) as a descriptor of multiple organ dysfunction/failure in intensive care.

DESIGN

Prospective, multicentre and multinational study.

SETTING

Forty intensive care units (ICUs) from Australia, Europe, North and South America.

PATIENTS

Data on 1,449 patients, evaluated at admission and then consecutively every 24 h until ICU discharge (11,417 records) during May 1995. Excluded from data collection were all patients with a length of stay in the ICU less than 2 days following uncomplicated scheduled surgery.

MAIN OUTCOME MEASURE

Survival status at ICU discharge.

INTERVENTIONS

The collection of raw data necessary for the computation of a SOFA score on admission and then every 24 h, and basic demographic and clinical statistics.

MEASUREMENTS AND MAIN RESULTS

Mean total maximum SOFA score presented a very good correlation to ICU outcome, with mortality rates ranging from 3.2% in patients without organ failure to 91.3% in patients with failure of all the six organs analysed. A maximum score was reached 1.1 +/- 0.2 days after admission for all the organ systems analysed. The total maximum SOFA score presented an area under the ROC curve of 0.847 (SE 0.012), which was significantly higher than any of its individual components. The cardiovascular score (odds ratio 1.68) was associated with the highest relative contribution to outcome. No independent contribution could be demonstrated for the hepatic score. No significant interactions were found. Principal components analysis demonstrated the existence of a two-factor structure that became clearer when analysis was limited to the presence or absence of organ failure (SOFA score > or = 3 points) during the ICU stay. The first factor comprises respiratory, cardiovascular and neurological systems and the second coagulation, hepatic and renal systems. Delta SOFA also presented a good correlation to outcome. The area under the receiver operating characteristic (ROC) curve was 0.742 (SE 0.017) for delta SOFA, lower than the total maximum SOFA score or admission total SOFA score. The impact of delta SOFA on prognosis remained significant after correction for admission total SOFA.

CONCLUSIONS

The results show that total maximum SOFA score and delta SOFA can be used to quantify the degree of dysfunction/failure already present on ICU admission, the degree of dysfunction/failure that appears during the ICU stay and the cumulative insult suffered by the patient. These properties make it a good instrument to be used in the evaluation of organ dysfunction/failure.

Kindling induces an asymmetric enhancement of N-type Ca2+ channel density in the dendritic fields of the rat hippocampus

The mechanisms underlying epilepsy are largely unknown. Recent genetic, pharmacological and electrophysiological data indicate a significant, but poorly understood, role for voltage-dependent calcium channels (VDCCs). Since the contribution of ion channels to nerve function depends on their cell surface distribution, we hypothesized that epilepsy might alter VDCC surface densities. To test this idea we mapped the expression and distribution of fluorescent-labeled hippocampal N-type VDCCs (N-VDCCs) in an animal model of epilepsy, amygdala kindling. Image analysis demonstrated that kindling induced a 21-40% increase in N-VDCC expression in CA1 but not CA3. This increase occurred in the stratum radiatum and was twice as high in tissues contra- versus ipsi-lateral to the stimulating electrode. These data rationalize recent electrophysiology and argue that a persistent alteration in N-VDCC trafficking in dendrites or nerve termini may contribute to seizure-induced synaptic plasticity.

Amygdala-kindled and electroconvulsive seizures alter hippocampal expression of the m1 and m3 muscarinic cholinergic receptor genes

Expression of m1 and m3 muscarinic cholinergic receptors mRNAs was examined in rat hippocampus following either: (1) kindling to five Stage 5 amygdala-kindled seizures; or (2) eight electroconvulsive shock (ECS) seizures. Twenty-four hours after the last seizure of either type, there was a significant decrease in both m1 and m3 mRNAs in CA1, CA3 and the dentate gyrus subfields of the hippocampus. Twenty-eight days after the last seizure of either type, there was a significant increase in m1 mRNAs in CA1, CA3, and the dentate gyrus; for m3 mRNAs, there was a significant increase in CA3 28 days after the last ECS seizure, and in CA1 and CA3 28 days after the last kindled seizure. These results suggest that seizures alter the cholinergic system in the hippocampus, and that some of the alterations are very long-lasting.

Long-term enhancement of entorhinal-dentate evoked potentials following 'modified' ECS in the rat

Electroconvulsive therapy (ECT) is widely used as a treatment for drug-resistant depression. The animal analogue of ECT is electroconvulsive shock (ECS) seizures. We have recently shown that repeated ECS seizures cause a long-lasting, perhaps permanent, enhancement in entorhinal-dentate evoked potentials in the rat. Our study, however, involved 'unmodified' ECS, whereas in clinical practice ECT is now usually given in its 'modified' form (with near-threshold currents, a short-acting barbiturate, muscle relaxant and oxygen). We have therefore repeated our experiments using modified ECS. Entorhinal-dentate evoked potentials were measured in Long-Evans rats before and after: (1) eight modified ECS seizures; or (2) eight sham modified ECS trials. Despite the use of the modified procedure, a significant and long-lasting enhancement in population spike amplitude was seen in the ECS group. We conclude that the modified procedure does not protect rats against the long-lasting enhancement of evoked potentials. Similar changes may be occurring in the brains of patients subjected to modified ECT.

[Preferential projections for mapping and ablation of tachycardia of the right ventricle outflow. Anatomoradiological study]

PURPOSE

To select ideal radiologic projections for mapping and ablation of tachycardias of right ventricular outflow tract (RVOT).

METHODS

Ten hearts from human corpses were studied utilizing radiopaque material to identify the pulmonary valve and three distinct sites on this valve: septal anterior (A), septal posterior (P) and free-wall (L). Next, the hearts were filmed in the frontal plane and in oblique projections with 15 degrees increments to the right and to the left. The projections in which the sites were lateralized on the valve, eased radiologic interpretation and were considered ideal for mapping and ablation. Depending on the proximity of the sites to the lateral extremes of the pulmonary valve, the projections were considered ideal ( ), intermediary (++) and inadequate (+).

RESULTS

Projections [table: see text]

CONCLUSION

The A site of RVOT was best indicated in the 60 and 45 degrees left anterior oblique projections; the 0 degree postero anterior projection was best for mapping the P site; the L region was best explored in the 60 degrees right anterior oblique projection.

[Analysis of the junctional rhythm characteristics in patients with nodal reentry tachycardia treated with slow pathway radiofrequency ablation]

PURPOSE

To study the quantitative and qualitative aspects of junctional rhythm (JR) during radiofrequency (RF) catheter ablation of slow pathway in atrioventricular nodal reentrant tachycardia.

METHODS

Twenty five patients, 5 males, ages ranging from 15 to 76 years, with recurrent atrioventricular nodal reentrant tachycardia, underwent to RF catheter ablation of slow pathway. During RF applications (40V, duration 60s) electrocardiographic was continuously recorded. The recordings were posteriorly used to study the presence and characteristics of JR (number of episodes, frequency and time of onset) at the effective and ineffective RF sessions. All variables were expressed as median and mean +/- SD. Univariate analysis of the effects of each variable on success or failure of ablation were performed using x2 test. A p value < 0.05 was considered significant.

RESULTS

One hundred forty nine RF sessions were performed, 25 effective and 124 ineffective (mean per patient 6, range 1 to 22). JR was present in 18 of 25 effective and 44 of 124 ineffective sessions (p < 0.05). Mean time of appearance was 12s, occurring later this time in 9 of 18 effective and in 10 of 44 ineffective sessions (p < 0.05). Mean number of episodes was 3, occurring higher number in 7 of 18 effective and in 4 of 44 ineffective sessions (p < 0.05). Median of frequency of JR was 100bpm; 11 of 18 effective and 15 of 44 ineffective sessions presented higher frequencies (p < 0.05).

CONCLUSION

JR during slow pathway ablation is a sensitive marker of ablation success. JR predictor of success has higher number of episodes, higher frequency and later time of appearance than that one of ineffective sessions.

Medical treatment of cardiac arrhythmias in Chagas' heart disease

There are no controlled clinical trials evaluating drug therapy in patients with ventricular arrhythmias and chronic chagasic cardiomyopathy. Empirical treatment with disopyramide (400-1, 1,000mg/d), phenytoin (4-6mg/d), mexiletine 600-1,200mg/d), propafenone (900mg/d), amiodarone (loading: 1,000mg/d, 10-14 days; maintenance 200-600mg/d), and sotalol (320mg/d) had efficacy and tolerance ranging from 18% to 90% with heterogeneous criteria for efficacy definition. Further studies with homogenous criteria are required to determine which is most appropriate drug therapy for patients with chronic chagasic cardiomyopathy and ventricular arrhythmias.

[Catheter ablation of ectopic incessant atrial tachycardia using radiofrequency. Reversion of tachycardiomyopathy]

A 8-year-old female patient with refractory incessant atrial tachycardia, very symptomatic and with left ventricular ejection fraction of 0.25. Electrophysiological study and endocardial mapping localized the site of the origin of atrial tachycardia in the superior right atrium. In this site 2 applications of radiofrequency current (25V, 20 and 50 seconds) resulted in termination of the atrial tachycardia. She was discharged off antiarrhythmic drugs and after 2 months ejection fraction was 0.52. She was completely asymptomatic 6 months after ablation procedure.

[Catheter ablation of tachycardia of the outlet right ventricle using radiofrequency as power source]

Two female patients, 54 and 38 years-old with refractory ventricular tachycardia were undertaken to electrophysiologic study for diagnosis and radiofrequency ablation of their arrhythmias. The tachycardias were only inducible with intravenous isoproterenol infusion. The site of the origin of ventricular tachycardia was localized in the right ventricular outflow tract in both cases. Radiofrequency current was delivered at 40V (40-60s) in each patient and was followed by complete abolition of ventricular arrhythmias.

[Radioisotopic mapping of the arrhythmogenic focus in patients with chronic chagasic cardiomyopathy and sustained ventricular tachycardia]

PURPOSE

To localize the site of the origin of sustained ventricular tachycardia in chronic chagasic cardiomyopathy patients refractory to antiarrhythmic therapy by radionuclide angiography techniques.

METHODS

Five patients underwent radionuclide angiography by intravenous administration of 25mCi 99mTc. The images were obtained in sinus rhythm and during sustained ventricular tachycardia induced in the electrophysiologic laboratory for endocardial mapping. Amplitude and phase images were obtained resulting in a contraction wave synchronic to ventricular dispolarization.

RESULTS

All patients had haemodynamic stability during the arrhythmia. One patient had incessant ventricular tachycardia. Mean ejection fraction was 0.38. In 4 patients the site of the origin of ventricular tachycardia was posterior and in one it was localized in the interventricular septum. There was identity in the site of the origin of ventricular tachycardia obtained by endocardial mapping or radionuclide angiography in all patients. The therapy was chemical ablation in 3 patients, surgical aneurysmectomy in one and pharmacologic therapy in the last patient.

CONCLUSION

The site of the origin of ventricular tachycardia can be estimated by analyzing the contraction wave obtained by radionuclide angiography techniques in patients with hemodynamic stable sustained ventricular tachycardia.

[Catheter ablation in patients with refractory cardiac arrhythmias with radiofrequency techniques]

PURPOSE

evaluate the efficacy of radiofrequency catheter ablation in patients with refractory cardiac arrhythmias.

METHODS

twenty patients with refractory cardiac arrhythmias were undertaken to electrophysiologic studies for diagnosis and radiofrequency catheter ablation of their reentrant arrhythmias. Ten patients were men and 10 women with ages varying from 13 to 76 years (mean = 42.4 years). Nineteen patients had supraventricular tachyarrhythmias: One patient had atrial tachycardia and 1 atrial fibrillation with rapid ventricular rate, 5 patients had reentrant nodal tachycardia, 12 patients had reentrant atrioventricular tachycardia and 1 patient had right ventricular outflow tract tachycardia.

RESULTS

the mean time of the procedure was 4.1 hours. The radiofrequency current energy applied was 40-50 V for 30-40 seconds. Ablation was successful in 18/20 (90%) patients; in 15/18 (83%) of successfully treated patients the same study was done for diagnosis and radiofrequency ablation. One patient had femoral arterial occlusion and was treated with no significant sequelae. During a mean follow-up of 4 months no preexcitation or reentrant tachycardia occurred.

CONCLUSIONS

the results of our experience with radiofrequency catheter ablation of cardiac arrhythmias suggest that this technique can benefit an important number of patients with cardiac arrhythmias.