Functional outcome in dogs undergoing hemilaminectomy for thoracolumbar disc extrusion but without nociception > 96 h: A prospective study

This prospective study investigated the functional recovery of surgically treated dogs with thoracolumbar intervertebral disc extrusion (IVDE) without deep pain perception (DPP) for > 96 h. Dogs (n = 36) with paraplegia secondary to thoracolumbar intervertebral disc extrusion with loss of deep pain perception ranging from 4 to 60 days were enrolled. All dogs underwent hemilaminectomy and fenestration of the affected intervertebral disc and postoperative follow-up was provided for a maximum of 180 days. Recovery of motor function was satisfactory (based on the owner's assessment) in 22 dogs, 61.1% (47.2% with DPP, and 13.9% without DPP) and unsatisfactory in 38.9% of cases (n = 14). Postoperative physiotherapy, preoperative anti-inflammatory drugs, and age had no effect on recovery. In this study, the longer the time taken to regain pain perception, the longer the recovery time. The median time to recovery was 30 days. A total of 47.2% of dogs with paraplegia and absence of DPP secondary to thoracolumbar IVDE lasting > 96 h, recovered functional ambulation after decompressive surgery.

Catecholaminergic polymorphic ventricular tachycardia: risk modulators in patients treated with beta-blockers

Background

Due to the catecholaminergic nature of arrhythmias that define the Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT), beta-blockers (BBs) represent the first line therapy for this severe arrhythmogenic syndrome. Despite optimal BB therapy, a proportion of patients continue to suffer breakthrough life-threatening arrhythmias (LAE).

Purpose

To evaluate the role different classes of BBs (β1-selective vs. non-selective) in LAE reduction and to identify risk factors for breakthrough LAE while on BB monotherapy.

Methods

We studied 238 consecutive patients with CPVT and treated with BB monotherapy followed-up prospectively. CPVT was diagnosed according to the 2015 European Society of Cardiology Guidelines. The endpoint was the occurrence of the first LAE (sudden cardiac death, aborted cardiac arrest, or hemodynamically non-tolerated ventricular tachycardia) in BB monotherapy. The follow-up for each patient was calculated from BB therapy start to the occurrence of the endpoint, death from non-arrhythmic cause, the date of last visit, or the initiation of other treatments (i.e.: other antiarrhythmics or left cardiac sympathetic denervation [LCSD]), whichever occurred first.

Multivariable Cox proportional hazards model was used to evaluate the effects of history of LAE before diagnosis of CPVT, occurrence of unexplained syncope before diagnosis of CPVT, genotype, and type of BB therapy, as a time-dependent variable, on the risk of experiencing an LAE during BB monotherapy.

Results

We enrolled 238 CPVT patients (135 probands, 135 females): 226 with typical CPVT (n=216 RYR2; n=10 CASQ2) and 12 with atypical CPVT (n=5 RYR2-Loss-of-Function, n=4 TRDN and n=3 TECRL).

Prior to BB monotherapy, 48/238 (20%) patients had survived an LAE, and 110/238 (46%) patients had experienced an unexplained syncope.

During 1,629 person-years of follow-up during BB monotherapy, 35 patients experienced an LAE (annual LAE rate 2.1%, 95% CI: 1.5%–3.0%; Figure A). Five-year cumulative probability of experiencing an LAE during BB monotherapy was 11.9% (95% CI: 7.0%-16.6%). In this population, multivariable analysis showed that history of LAE before diagnosis (HR 3.6; 95% CI: 1.6–8.1; p=0.002) and syncope before diagnosis (HR 6.1; 95% CI: 2.5–14.9; p<0.001) were clinical risk factors for LAE occurrence. Patients with TRDN mutations were significantly more likely to suffer LAE (HR 20.9; 95% CI: 2.2–196.3; p=0.008). Using nadolol as the gold standard, the use of β1-selective BBs (HR 3.4; 95% CI: 1.4–8.6; p=0.009), but not propranolol (HR: 0.9; 95% CI: 0.2–3.8; p=0.887), was associated with poorer outcome during BB monotherapy (Figure B).

Conclusions

In patients with CPVT, selective BBs are associated with a higher risk of LAE as compared to nadolol. Patients who have survived an LAE and/or experienced an unexplained syncope prior to diagnosis, as well as carriers of TRDN mutations are at high risk of BB failure.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Ricerca Corrente Funding scheme of the Italian Ministry of Health and Italian Ministry of Research and University Dipartimenti di Eccellenza 2018–2022 grant to the Molecular Medicine Department (University of Pavia).

Natural History of Patients with Typical and Atypical Catecholaminergic Polymorphic Ventricular Tachycardia

Background

Recently, a novel genetic-based classification for Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT) has been proposed to distinguish “typical” (RYR2 and CASQ2 genes) and “atypical” (TRDN, TECRL, CALM1–3, RYR2 loss-of-function [RYR2-LoF]) CPVT variants. Although some genetic forms were reported as malignant forms of CPVT, natural history data comparing typical and atypical CPVT variants are lacking.

Purpose

We compared the natural history of “typical” and “atypical” forms of CPVT in a large cohort of patients with genetically confirmed CPVT.

Methods

CPVT was diagnosed according to the criteria defined in the 2015 European Society of Cardiology Guidelines. Based on the genetic background, we classified the patients in two groups: 1) “Typical” CPVT (i.e., carriers of pathogenic or likely pathogenic mutations in RYR2 and CASQ2 genes); 2) “Atypical” CPVT (i.e., carriers of pathogenic or likely pathogenic mutations in TRDN, TECRL, CALM1–3 and RYR2-LoF). Patients with mutations in the CALM1, CALM2 or CALM3 were not identified in our cohort. The outcome was the occurrence of a life-threatening arrhythmic event (LAE), defined as: sudden cardiac death, aborted cardiac arrest or hemodynamically non-tolerated ventricular tachycardia. The Kaplan-Meier life-table method was used to determine the cumulative probability of experiencing a first LAE before the age of 40 years and in the absence of treatment. Outcomes in two groups were compared using the log-rank test.

Results

The study cohort included 238 patients (56% females, median age at diagnosis 14 years [IQR: 9–28 years]), of whom 226/238 (95%) patients with “typical” CPVT (216 RYR2, 10 CASQ2), and 12/238 (5%) patients with “atypical” CPVT (5 RYR2-LoF, 4 TRDN, 3 TECRL). In the entire population, the cumulative probability of experiencing a first LAE between birth and the diagnosis of CPVT was 2.3%, 21.2 and 40.8% at 5, 20, and 40 years, respectively. At any given age, the probability of a first LAE in the absence of therapy was significantly higher in patients with atypical CPVT (25%, 36%, and 100% at 5, 20, and 40 years, respectively), as compared to patients with typical CPVT (1%, 20%, and 39% at 5, 20, and 40 years, respectively; p=0.003, Figure 1). Patients with atypical CPVT suffered LAEs in early childhood (i.e., by the age of 5 years) significantly more often than patients with typical CPVT (3/5 patients [60%] in atypical CPVT vs. 2/43 patients [5%] in typical CPVT, p<0.001; Figure 2).

Conclusions

The natural history of CPVT is modulated by the genetic cause. Atypical CPVT variants are rare but are characterized by a worse outcome and a greater likelihood of experiencing an LAE since the early childhood, as compared to typical CPVT.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Ricerca Corrente funding scheme of the Italian Ministry of Health

Efficacy and safety of the ICD in patients with catecholaminergic polymorphic ventricular tachycardia

Background

Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT) is a potentially fatal genetic arrhythmia syndrome and, despite optimal beta-blocker (BB) therapy, patients often experience life-threatening arrhythmic events (LAE). The role of implantable cardioverter defibrillators (ICD) on reducing mortality in patients with CPVT is debated.

Purpose

1) To assess the survival benefit of ICD in the overall CPVT population; 2) to investigate the benefit-to-harm ratio in the population of CPVT patients carriers of ICD.

Methods

We followed-up consecutive patients with genetically-proven CPVT, treated with optimal BB mono-therapy. The probability of surviving at the occurrence of a first LAE (defined as: sudden cardiac death, aborted cardiac arrest or hemodynamically non-tolerated ventricular tachycardia) during BB mono-therapy was compared between ICD carriers and non-ICD carriers.

In the cohort of ICD carriers, we assessed the rate of a first major complication (i.e., a complication requiring surgical intervention) and we calculated the benefit-to-harm ratio of ICD (defined as rate of appropriate shocks on LAE over rate of major complications).

Results

We enrolled 228 CPVT patients with a pathogenic RYR2 (n=216) or CASQ2 (n=12) mutation, of whom 87 (38%) had an ICD implanted. Overall, during 1,558 person-years of follow-up, 31/228 (14%) patients experienced a first LAE on BB mono-therapy (annual LAE rate 2.0%, 95% CI: 1.4–2.8%).

Of the 31 individuals who experienced an LAE, 21 patients had an ICD when the LAE occurred, and all survived after ICD intervention. Of the remaining 10 patients who were not carriers of an ICD, 6/10 (60%) survived after external defibrillation or spontaneous arrhythmia termination, while 4/10 (40%) died suddenly. The probability of surviving at the occurrence of a first LAE in BB mono-therapy was thirty-fold higher (Odds Ratio: 30.0, 95% CI: 1.4–629.0; p=0.029) in patients with an ICD, as compared to patients without an ICD.

Overall, 15/87 (17%) patients with an ICD experienced a first major complication over 602 person-years of follow-up (2.5% per year, 95% CI: 1.4%-4.1%). Importantly, no patient died for a pro-arrhythmic effect or complications related to ICD. Comparing the rate of major complications to the rate of appropriate ICD shocks on LAE (LAE rate 4.7% per year, 95% CI: 3.1–7.0%), the benefit-to-harm ratio was 1.9, thus favouring the benefit of ICD therapy.

Conclusions

In our population, ICD therapy conferred a significant survival benefit in patients with CPVT at the occurrence of a first LAE. Overall, the benefit of ICD implant outweighed the harm, as shown by almost two times greater benefit-to-harm ratio. This study provides evidence supporting ICD implantation in patients with high-risk CPVT.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Ricerca Corrente Funding Scheme of the Italian Ministry of Health

Is mexiletine ready for prime time in patients with Type 2 Long QT Syndrome?

Background

Mexiletine has been proven effective in shortening the duration of ventricular repolarization and reducing the arrhythmic events in type 3 Long QT Syndrome (LQT3). Initial reports indicate that mexiletine might also be effective in patients with type 2 Long QT Syndrome (LQT2, caused by loss-of-functions variants on KCNH2 gene, coding for HERG potassium channel), but this issue has not been investigated in detail.

Purpose

We quantified the electrocardiographic (ECG) effects of mexiletine in a cohort of LQT2 patients.

Methods

Twelve-lead ECGs were collected before and after the administration of mexiletine to evaluate the drug's effect on the heart rate-corrected QT interval (QTc). QTc intervals were classified as being (1) at “high-risk” if >500 ms or (2) “normal” if <460 ms, before and after the administration of the drug. KCNH2 variants were defined as (1) trafficking-deficient or (2) non-trafficking-deficient, based on functional studies.

Results

We tested the maximum tolerated dose of mexiletine in 20 patients (11 males, 55%), who were 17±16 years old at diagnosis, affected by genetically established LQT2. The mean age at the beginning of mexiletine administration was 23±15 years and the mean daily dose administered was 9±2 mg/kg/day.

Before mexiletine, the mean QTc interval was 527±53 ms and 10/20 (50%) patients had high-risk QTc values (i.e. QTc >500 ms).

After mexiletine, the mean QTc interval shortened to 484±47 ms in the overall population (p=0.001). In the majority of patients (18/20, 90%; Figure 1) QTc interval shortened, with a mean shortening of 42±28 ms, and a high-interindividual variability (range of shortening from 86 ms to 8 ms). Just 2 (10%) patients did not show any reduction of the QTc, despite receiving the highest adult dosages of mexiletine in our cohort (up to 10 mg/kg/day).

As compared to baseline conditions, after mexiletine the proportion of patients with high risk QTc values (>500 ms) decreased non-significantly from 50% to 35% (p=0.52). Furthermore, in only 6/20 (30%) patients the QTc normalized (i.e. QTc <460 ms) after the initiation of treatment.

The effect of mexiletine was not influenced by gender (p=0.89) or by the functional effect of the KCNH2 mutation (trafficking-deficient vs. non-trafficking-deficient variants, p=0.41).

The effect of mexiletine in LQT2 patients was inferior to the one previously observed in a cohort of 34 LQT3 patients, who had similar QTc values at baseline and received similar dosages of mexiletine, but showed a significantly higher reduction of the average QTc interval (63±37 ms in LQT3 vs. 42±28 ms in LQT2, p=0.02).

Conclusions

Mexiletine induces a reduction of the QTc interval in most LQT2 patients, but many patients remain with high-risk QTc values after receiving the drug. The demonstration that an average QTc shortening of 42 ms is enough to reduce arrhythmic events is necessary, before the introduction of mexiletine in clinical practice for LQT2.

Figure 1

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Italian Ministry of Research and University Dipartimenti di Eccellenza 2018–2022 grant to the Molecular Medicine Department (University of Pavia)

Novel insights on Andersen-Tawil syndrome type 1

Background

Andersen-Tawil Syndrome type 1 (ATS1) in a rare arrhythmogenic disease caused by loss-of-function mutations in the KCNJ2 gene and characterized by ventricular arrhythmias, dysmorphic features and episodes of periodic paralysis. Although the prognosis of ATS1 patients is typically considered benign, definitive outcome data are lacking.

Purpose

We aimed to: 1) define the risk of life-threatening arrhythmic events (LAEs); 2) identify risk factors for such events; 3) assess the efficacy of anti-arrhythmic drugs in preventing LAEs.

Methods

We included 118 ATS1 patients from 57 families with confirmed pathogenic or likely pathogenic KCNJ2 mutations. Clinical and genetical data were acquired by investigators from 23 centers in 9 countries.

Results

Baseline characteristics of the population are presented in the Table. Over a follow-up of 6.2 years, 17/118 (14%) patients experienced a first LAE, with a 5-year cumulative probability of 7.9% (Figure). Cox multivariable analysis demonstrated that a previous history of syncope (HR 4.5, p=0.02), the documentation of sustained VT (HR 9.3, p=0.001) and the administration of amiodarone (HR 268, p<0.001) were associated with an increased risk of LAE. The baseline rate of LAE was not reduced by beta-blockers alone (1.37 per 100 py; p=1), or in combination with class Ic antiarrhythmic drugs (1.46 per 100 py, p=1).

Conclusions

Our data demonstrate that the clinical course of patients with ATS1 is characterized by a high rate of LAE. A history of unexplained syncope, and documentation of sustained ventricular tachycardia are independently associated with a higher risk of LAE. Amiodarone is proarrhythmic and should be avoided in ATS1 patients.

ATS1: Diagnosis, Outcome, Risk Factors

Funding Acknowledgement

Type of funding source: Public grant(s) – EU funding. Main funding source(s): ERN Guard-Heart European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart

Automated screening tool for Subcutaneous Implantable Defibrillator in Brugada syndrome has a high eligibility rate which is predicted by simple electrocardiographic parameters

Background

Manual electrocardiographic (ECG) screening tools for the use of subcutaneous cardiac defibrillator (S-ICD) have been associated with high ineligibility rates in Brugada syndrome patients (BrS). Although recent works identified ECG parameters for S-ICD eligibility in general population, automated screening tool (AST) for S-ICD eligibility have not even been assessed in large series of patients with BrS.

Purpose

This study evaluates the AST-derived eligibility rates for an S-ICD in patients with BrS, and ECG parameters associated with S-ICD eligibility.

Methods

Screening for S-ICD eligibility was performed using AST in 194 consecutive patients with BrS. Eligibility was defined when at least one of the three vectors was acceptable both in supine and standing position. Twelve-lead ECGs were registered during the screening. ECG parameters associated with AST eligibility were identified using multivariable logistical regression.

Results

Our study population consisted of 194 patients, with male preponderance (n=165/194; 85%); and were 43±12 years old at the time of screening. Majority of patients presented a spontaneous type 1 pattern during screening (n=128/194; 66%), with an average pattern height of 3±3 mm.

Remarkably, 93% of patients passed the screening with AST. No differences in eligibility rates in terms of gender (93% males vs. 93% females eligible; p=1) and age (48±9 years non-eligible vs. 42±12 eligible; p=0.07) existed. Notably, our eligibility rate was 2.5 times higher than rates reported in literature when using manual screening tools (p=0.023). Independent 12-lead ECG parameters (Table) associated with AST eligibility were duration of S wave <80 ms in aVF and R/T ratio ≥3 in lead II (Figure), which have a high positive predictive value (97% and 99%, respectively) for screening eligibility.

Conclusions

Most BrS patients (93%) are eligible for S-ICD when AST is used. S wave <80 ms in aVF, and R/T ratio ≥3 in lead II have a high positive predictive value for S-ICD eligibility.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): The Italian Ministry of Research and University Dipartimenti di Eccellenza 2018–2022 grant to the Molecular Medicine Department (University of Pavia)

Characterization of arrhythmic presentation in patients with arrhythmogenic cardiomyopathy

Background/Introduction

Arrhythmogenic cardiomyopathy (ACM) is one of the most arrhythmogenic conditions known to man. ACM is caused by desmosomal mutations in most cases, resulting in progressive replacement of the myocardium by adipose and fibrous tissue. It comes as no surprise that ACM is one of the leading causes of sudden cardiac death (SCD). Nonetheless, the characteristics of arrhythmic manifestations have not dissected after the release of most recent criteria.

Purpose

This study investigates different types of ventricular tachyarrhythmias which had occurred at first arrhythmic event in patients with ACM.

Methods

We investigated 91 consecutive patients with documented evidence of sustained ventricular tachyarrhythmias from 291 ACM patients followed at our center up to this date. Diagnosis of ACM was made using 2010 Task Force Criteria, and patients were defined as having an advanced disease if they had more than 4 TFC points at diagnosis. Presenting ventricular tachyarrhythmias were divided into (1) life-threatening arrhythmic event (LAE; ventricular fibrillation or hemodynamically unstable polymorphic ventricular tachycardia) and (2) hemodynamically stable monomorphic ventricular tachycardia (MMVT). Right ventricular (RV) involvement was defined as a presence of RV wall motion abnormalities and RV dilation at transthoracic echocardiography or cardiac magnetic resonance.

Results

Our study population was constituted of a predictably higher number of males (n=68; 75%), with an average age at the first arrhythmic event of 38±15 years of age.

At first documented arrhythmia, majority of patients studied experienced a stable MMVT (n=53; 58%), while 38 patients experienced an LAE (n=38; 42%). The patients suffering an LAE as first arrhythmic event were slightly younger than the patients who experienced a stable MMVT (35±14 years vs. 40±15 years; p=0.076) but there were no statistically significant gender differences (28/38 males with LAE vs. 40/53 males with stable MMVT; p= n.s.).

Interestingly, patients who presented with stable MMVT were more likely to have an advanced disease at diagnosis (OR=6.52; 95% CI 2.02–20.99; p=0.002). This is supported by the fact that RV involvement was significantly more common in patients presenting with stable MMVT (OR=4.38; 95% CI 1.26–15.26; p=0.021). Additionally, patients with stable MMVT were more commonly carriers of variants on PKP2 gene (OR=3.6; 95% CI 1.1–11.91; p=0.021).

Conclusions

Our data suggest that two types of arrhythmia reflect the two different stages of the disease. The early stage of the ACM is characterized by LAE in absence of RV structural involvement; while, stable MMVT is typical of PKP2 carriers and advanced stage of ACM with RV involvement.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): The Italian Ministry of Research and University Dipartimenti di Eccellenza 2018–2022 grant to the Molecular Medicine Department (University of Pavia)

Mutation site-specific risk profile in patients with Type 1 Long QT Syndrome

Background

Type 1 Long QT Syndrome (LQT1) is an arrhythmogenic disorder, caused by loss-of-function mutations on KCNQ1 gene, coding for Kv7.1 potassium channel. Although LQT1 is described as the most benign form of LQTS, patients still experience arrhythmic events and there is an unmet need for personalized risk stratification. Attempts have been made to correlate the location of mutations with outcome, but the results are unequivocal.

Purpose

We provide in the present study a new mutation site-specific risk profile obtained from a large cohort of LQT1 patients.

Methods

We gathered data on 963 patients with the diagnosis of LQT1 and divided the Kv7.1 channel into 5 functional regions: the N-terminus (NT), the voltage sensor (VS, including transmembrane segments S1 to S4), the cytoplasmic loops (CL), the pore (PO, including the transmembrane segments S5, S6 and the S5-S6 extracellular linker), the C-terminus (CT).

Results

We studied 963 LQT1 patients: 518 (54%) females; average age 20±17 years; mean QTc at baseline ECG 465±38ms. During a mean follow-up of 8±7 years, 172 (18%) patients experienced arrhythmic events: 31 (3%) experienced one or more cardiac arrests, while 141 (15%) experienced one or more syncopal spells. We identified 188 different variants in the KCNQ1 gene, with the following distribution: 15 (8%) in the NT, 33 (18%) in the VS, 27 (14%) in the CL, 43 (23%) in the PO, 70 (37%) in the CT. The frequency of pathogenic variants per number of amino acids (a.a.) was higher in the CL region, as compared to the other domains (1 mutation every 1.4 a.a.). The duration of QTc interval was significantly longer for patients with mutations in the PO region (473±40 ms) and in the CL region (468±38 ms) as compared to the other regions (p<0.01).

Importantly, in a multivariate analysis PO and CL regions were associated with a higher probability of experiencing arrhythmic events (OR 2.89, 95% CI 1.95–4.29, p=0.019 and OR 1.61, 95% CI 1.0–2.49, p=0.05, respectively. Figure) than the other regions. Interestingly, the risk was independent from QTc interval duration.

Conclusions

Mutations affecting the PO and the CL region of the Kv7.1. channel are associated with a higher probability of experiencing arrhythmic events. This finding is clinically relevant, because it will allow for a more personalized, mutation site-specific risk stratification.

Mutation site and arrhythmic events

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Italian Ministry of Research and University Dipartimenti di Eccellenza 2018–2022 grant to the Molecular Medicine Department (University of Pavia)

Role of CACNA1C variants in Brugada syndrome: clinical aspects and genetic testing strategies

Background

Inconsistent data support the role of CACNA1C as a disease-causing gene responsible for Brugada syndrome (BrS). As of today, the only gene consistently linked with BrS is SCN5A. Several CACNA1c genetic variants have been reported in association wirh BrS; however, due to the limited evidence, CACNA1C is not suggested for routine genetic screening for BrS.

Purpose

In this study, we carried out a systematic screening of CACNA1C gene, including a functional evaluation of the identified variants, in order to determine the yield of screening in a large series of BrS probands and to address the hypothesis that an appropriate clinical selection of patients would substantially improve the yield of genetic testing.

Methods and results

Overall 564 consecutive patients, referred for BrS genetic testing, were sequenced for CACNA1C gene. Patients were divided in two groups: discovery cohort (n=200 patients) and confirmation cohort (n=363 patients). Furthermore, analysis of the clinical phenotypes of a matched SCN5A positive BrS cohort (n=146) was included for phenotype characterization.

In the discovery cohort we identified 11 different genetic variants of whom 2 (18%) were considered as potentially causative based on ACMG guidelines. However, a large proportion (81%) was classified as variants of unknown significance (VUS). Functional evaluation of the identified variants, including pathogenic and VUS, was assessed by patch-clamp and immunofluorescence studies. Re-evaluation of the variants, including functional studies results, indicated an increase of pathogenic or likely pathogenic variants (81%) getting a yield of screening of 5% in the discovery cohort. Results from the confirmation cohort confirmed a low rate of CACNA1C carriers with a yield of screening of 2.2%.

Analysing the clinical phenotype of all CACNA1C carriers showed a significantly shorter QTc [371 ms ± 16 ms vs. 399±18 ms; p=0.000004]. Furthermore, the prevalence of CACNA1C variants was highest (12.9%) among patients with a QTc in the lowest quartile (QTc <390 ms). ROC curve showed an AUC of 0.91 for QTc a cut-off of 385 ms, suggesting a high predictive accuracy.

Conclusion

We confirmed that CACNA1C variants are not a common cause of BrS, with a yield of screening of 2–5%. However, pathogenic variants are more frequent (12.5%) in patients with a shorter QTc, suggesting a genetic testing strategy in this subgroup of BrS patients. Furthermore, our data highlights the impact of robust functional studies to improve variant classification and reduce uncertainties.

Funding Acknowledgement

Type of funding source: None

Proposta de sequenciamento das projeções mielográficas na identificação de compressão da medula espinhal em cães com doença do disco intervertebral cervical

RESUMO O objetivo deste trabalho foi verificar em quais projeções foi possível identificar compressão da medula espinhal em cães com doença do disco intervertebral (DDIV) cervical e propor um sequenciamento das projeções a ser realizado no exame mielográfico dessa região. Foram avaliadas quatro projeções mielográficas (lateral, ventrodorsal e oblíquas esquerda e direita) de 41 pacientes diagnosticados com DDIV cervical. Em 40 pacientes (97,5%), foi possível identificar compressão da medula espinhal na projeção lateral; em 22 (53,6%), nas oblíquas; e em 11 (26,8%), na ventrodorsal (P<0,05). Havia lateralização da compressão em 22 (53,6%) pacientes; 100% delas (n=22) foram detectadas pelas projeções oblíquas e 50% (n=11) pela ventrodorsal. Em 10 (24,4%) cães, foi observado mais que um local de compressão, tendo as projeções ventrodorsal e oblíquas auxiliado na definição do local de compressão em 50% e 70%, respectivamente. Pode-se concluir que todas as projeções mielográficas estudadas permitem identificar compressão na medula espinhal em cães com DDIV cervical, sendo a incidência lateral a que mais a revelou, seguida das oblíquas e da ventrodorsal, estabelecendo-se, assim, uma proposta de sequenciamento das projeções mielográficas a serem realizadas para essa região.

P3685Can 3D echocardiography give a contribute to the diagnosis of Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC)?

Background

The diagnosis of ARVC is based on the structural assessment of the heart with 2D echocardiography (2DE) and cardiovascular MRI (CMR) to detect the presence of global and segmental right ventricular (RV) abnormalities. Little is known about the diagnostic value of 3D echocardiography (3DE) in ARVC. The aim of this study was to assess whether a combination of 2DE and 3DE could replace 2DE and CMR combination with similar diagnostic accuracy in patients with suspected ARVC.

Methods

Thirty-nine subjects (59% males, 47±15 years, 41% with desmosomal mutations) with suspected or confirmed diagnosis of ARVC underwent evaluation of the RV with the use of CMR, 2DE, 3DE.

3DE and CMR were independently used to obtain RV volumes, ejection fraction and presence of segmental RV abnormalities. These studies were blindly classified as meeting none, minor, or major criteria for ARVC in accordance with the 2010 TFC. Kappa statistics were used to assess the concordance between 2DE-CMR and 2DE-3DE diagnostic approaches.

Results

Using the 2DE-CMR approach, patients were classified as follows: 5 not affected, 8 with possible, 9 with borderline and 17 with definite ARVC diagnosis. The evaluation of TFC criteria with the 2DE-3DE approach yielded a high degree of concordance with the standard of care (2DE-CMR approach, K=0.93 with 95% CI: 0.84–1.0). There was complete agreement between the 2DE-CMR and 2DE-3DE approaches for individuals with definite ARVC diagnosis (n=17) and in individuals not affected by ARVC (n=5). Two patients with possible and borderline ARVC diagnosis using the 2DE-CMR approach were confirmed as definite ARVC with 2DE-3DE approach.

Contribution of 3D echo to ARVC

Conclusions

The use of 2D and 3D echocardiography allows bedside evaluation of patients with suspected ARVC, which is diagnostically comparable to that obtained using the traditional combination of 2DE-CMR. This information is particularly relevant for patients who cannot undergo CMR such as patients with ICD.

6123A novel ECG parameter predicts lack of eligibility for Subcutaneous Implantable Cardioverter Defibrillator (S-ICD) in patients with Brugada Syndrome

Background

A conclusive estimate of the eligibility rate for the use of subcutaneous implantable cardioverter defibrillators (S-ICD) in patients with Brugada Syndrome (BrS) is lacking.

Objective

We aimed to: 1) evaluate the eligibility for S-ICD in patients with BrS using a novel automated tool; 2) investigate predictors of ineligibility for S-ICD, based on baseline 12-lead electrocardiogram.

Methods

Automated screening for S-ICD was performed in 118 consecutive BrS patients using the programmer provided by the S-ICD producer. The system automatically assessed the acceptability of each of the three sense vectors used by the S-ICD for the detection of cardiac rhythm. Eligibility was defined when at least one vector was acceptable both in supine and standing position.

Results

The clinical characteristics of 118 BrS patients were as follow: age 43±11 years; 89% males; 2% with aborted cardiac arrest; 14% with a history of syncope; 81% with spontaneous type 1 ECG pattern; 21% with a familial history of sudden cardiac death; 24% with an SCN5A mutation. No patients had an indication for pacing. Only 8/118 (7%) patients were ineligible for S-ICD. Of note, 5/8 (63%) patients who failed the screening exhibited a slurred S wave of ≥80 ms duration in the peripheral lead aVF on the 12-lead baseline electrocardiogram, vs. 4/110 (4%) of those who passed the screening (sensitivity of S wave in aVF for screening failure 63%, specificity 97%; p<0.001). Remarkably, the presence of a slurred S wave of ≥80 ms duration in lead aVF remained significantly associated to the failure of eligibility for S-ICD (odds ratio 50, p<0.001) in a multivariable analysis that included the previous history of symptoms, the presence of a spontaneous type 1 ECG pattern, the gender and the presence of SCN5A mutations.

ECG predictor of S-ICD screening

Conclusion

Up to 93% of BrS patients are eligible for S-ICD when the automated screening tool is used. The presence of a slurred S wave in lead aVF on the 12-lead electrocardiogram is a powerful predictor of screening failure.

6081Efficacy and limitations of quinidine therapy in patients with Brugada Syndrome

Background

Quinidine at high-dose is used in patients with Brugada Syndrome (BrS), but its efficacy to prevent life-threatening arrhythmic events (LAE) in BrS is unproven and its use is limited by side effects.

Objective

We assessed whether low-dose quinidine in BrS patients reduces: 1) the occurrence of a first LAE; 2) the arrhythmic burden in the high-risk group of cardiac arrest survivors.

Methods

We first compared the clinical course of 53 BrS patients treated with quinidine to that of 441 untreated controls, matched by sex, age, and symptoms. Furthermore, we calculated the annual incidence of LAEs off- and on-quinidine in 123 BrS patients who had survived a cardiac arrest.

Results

First, we compared the clinical course of 53 BrS patients treated with quinidine (i.e. “cases”: 89% males, median age 40 years) to that of 441 untreated, clinically-matched BrS patients (i.e. “controls”: 91% males, median age 41 years) present in our database of patients with inherited arrhythmias. Cases received quinidine (median dose of 450 mg per day) for 5.0±3.7 years. Quinidine was interrupted in only 3/53 cases (6%) for side effects and it conferred a nonsignificant reduction of the risk of a first LAE in cases versus controls (HR 0.74, 95% CI 0.22–2.48, P=0.62).

Secondly, we calculated the annual recurrence of LAE off- and on-quinidine in 123 BrS cardiac arrest survivors, 27 of whom were treated with quinidine for 7.0±3.5 years. The annual rate of recurrent LAEs decreased significantly from 14.7% while off-quinidine to 3.9% while on-quinidine (P=0.03). Notably, recurrent life-threatening arrhythmic events were recorded in 4/27 (15%) symptomatic patients while on-quinidine.

Conclusion

We demonstrated for the first time in the long-term that low-dose quinidine reduces the recurrence of life-threatening arrhythmias in symptomatic BrS patients, with few side effects. Remarkably, about one-fifth of symptomatic patients experience life-threatening arrhythmias while on-treatment, suggesting that quinidine cannot replace implantable defibrillators in high-risk subjects.

Modalidades fisioterapêuticas na reabilitação de cães com doença do disco intervertebral toracolombar submetidos à cirurgia descompressiva: 30 casos (2008-2016)

RESUMO Este estudo retrospectivo teve como objetivo demonstrar as modalidades fisioterapêuticas empregadas no tratamento de cães com doença do disco intervertebral (DDIV) toracolombar após descompressão cirúrgica da medula espinhal, bem como relatar os fatores que determinaram as alterações das modalidades. Foram incluídos 30 cães que apresentavam sinais neurológicos desde paraparesia ambulatória a paraplegia com dor profunda na primeira sessão de fisioterapia. As modalidades utilizadas nos protocolos de todos os pacientes foram a crioterapia, massagem, alongamento passivo, movimentação passiva articular, estímulo do reflexo flexor e estimulação elétrica neuromuscular. A inclusão ou exclusão de exercícios terapêuticos, como a tipoia corporal, a plataforma proprioceptiva circular, a natação, a hidroesteira, os obstáculos e a caminhada em colchão, foi de acordo com a evolução clínica e a adaptação de cada paciente. Oitenta por cento (80%) dos cães alteraram o grau de disfunção neurológica antes de iniciar a fisioterapia e 93% retornaram à habilidade de caminhar (paraparesia ambulatória) ao final da fisioterapia. O número de sessões e o tempo de recuperação foram maiores quanto pior foi o grau de lesão do paciente.

Viabilidade da técnica de transposição uretral pré-púbica mediante secção peniana em cadáveres de cães

RESUMO Descreve-se a viabilidade da técnica cirúrgica de transposição uretral pré-púbica em cadáveres de cães machos, adultos, advindos de um hospital veterinário, a fim de se avaliar a manutenção da luz uretral a partir de um desvio uretral pré-púbico, descrevendo-se detalhadamente a abordagem e as estruturas anatômicas envolvidas. A técnica consistiu inicialmente da orquiectomia, seguida de celiotomia retroumbilical, tração vesical cranial, secção transversa da uretra membranosa a 1cm caudal à próstata, espatulação e reparo da borda livre. A seguir, divulsão e secção do pênis 1,5cm caudal ao osso peniano, espatulação da borda uretral peniana e transposição desta em direção à cavidade abdominal, fazendo-se anastomose por meio de sutura interrompida simples à uretra membranosa. Foi mensurado o comprimento uretral desde o meato externo até o início da uretra prostática em dois momentos: pré e pós-transposição. Ao final, avaliou-se, por meio de uretrografia retrógrada de contraste positivo, o diâmetro e o selamento na anastomose uretral e o fluxo do contraste até a bexiga. A transposição uretral pré-púbica é uma técnica cirúrgica exequível, anatomicamente compatível com a espécie canina e capaz de manter o diâmetro uretral e o fluxo do contraste de forma satisfatória, com manutenção estética externa idêntica a um cão macho orquiectomizado.

Atropisomerism in 3-arylthiazolidine-2-thiones. A combined dynamic NMR and dynamic HPLC study

Sterically hindered 3-arylthiazolidine-2-thiones were prepared by a solvent-free reaction with arylisothiocyanates and 1,4-dithiane-2,5-diol. Atropisomerism was observed in two compounds (3 and 4, aryl = 1-naphthyl and 2-methylnaphth-1-yl), whose rotational energy barriers were measured using dynamic NMR and dynamic HPLC. The experimental analyses were supported by DFT calculations. Thermally stable atropisomers were obtained by dehydration of compounds 3 and 4 and the absolute configuration of the atropisomers of compound 6 was determined by theoretical simulation of the ECD and VCD spectra.

UceWeb: a Web-based Collaborative Tool for Collecting and Sharing Quality of Life Data

Objectives: This work aims at building a platform where quality-of-life data, namely utility coefficients, can be elicited not only for immediate use, but also systematically stored together with patient profiles to build a public repository to be further exploited in studies on specific target populations (e.g. cost/utility analyses).

Methods: We capitalized on utility theory and previous experience to define a set of desirable features such a tool should show to facilitate sound elicitation of quality of life. A set of visualization tools and algorithms has been developed to this purpose. To make it easily accessible for potential users, the software has been designed as a web application. A pilot validation study has been performed on 20 atrial fibrillation patients.

Results: A collaborative platform, UceWeb, has been developed and tested. It implements the standard gamble, time trade-off and rating-scale utility elicitation methods. It allows doctors and patients to choose the mode of interaction to maximize patients’ comfort in answering difficult questions. Every utility elicitation may contribute to the growth of the repository.

Conclusion: UceWeb can become a unique source of data allowing researchers both to perform more reliable comparisons among healthcare interventions and build statistical models to gain deeper insight into quality of life data.

Extrusão de disco intervertebral caudal (coccígea) em um Basset Hound: primeiro relato de caso

RESUMO Relata-se o primeiro caso no Brasil de doença do disco intervertebral (Hansen tipo I) entre as vértebras caudais (coccígeas) em uma cadela Basset Hound com seis anos de idade, castrada, pesando 16kg e com histórico de dor durante defecação e manipulação da região pélvica associada à inabilidade de mover, elevar ou abanar a cauda. Na radiografia simples, observou-se opacidade do forame intervertebral entre a quarta e a quinta vértebra caudal. O animal foi submetido à laminectomia dorsal modificada, seguida de fenestração do disco intervertebral afetado. Decorridos 15 dias da cirurgia, a paciente não demonstrava sinais de dor ao defecar e realizava movimentos de abano de cauda, mas ainda com desconforto na palpação e sem elevação da cauda acima da coluna vertebral, o que foi resolvido após 30 dias do procedimento cirúrgico. A relevância do caso está na inclusão, mesmo que rara, da doença do disco intervertebral caudal no diagnóstico diferencial em cães com dor durante a defecação e manipulação da cauda, sendo o exame radiográfico uma ferramenta auxiliar importante para o diagnóstico definitivo e o plano terapêutico.

Sonda uretral flexível como método alternativo para aferição invasiva da pressão intracraniana em trauma cranioencefálico induzido em coelhos

RESUMO O objetivo deste estudo foi utilizar a sonda uretral flexível como método alternativo para aferição da pressão intracraniana em coelhos com trauma cranioencefálico induzido pelo cateter de Fogarty 4 Fr (balão epidural) e comparar os dados obtidos com o método convencional de cateter de ventriculostomia. Foram utilizados 12 coelhos, machos, adultos, distribuídos aleatoriamente em dois grupos, denominados de G1: mensuração da PIC com cateter de ventriculostomia (n=6) e G2: mensuração com sonda uretral (n=6). Foram realizadas duas craniotomias na região parietal direita e esquerda para a implantação do cateter de ventriculostomia ou sonda uretral flexível e o balão epidural, respectivamente. A PAM, a PPC, a FC, a FR e a TR foram mensurados antes e após a craniotomia. A PIC foi avaliada após a craniotomia e a cada 10 minutos depois do preenchimento do balonete com 0,3mL de NaCl 0,9%, durante 40 minutos, e com 0,6mL, pelo mesmo período de tempo, totalizando 80 minutos. A PIC aumentou em ambos os grupos, sendo menores os valores registrados com a sonda uretral flexível. Foi possível reproduzir o aumento da PIC com o modelo experimental de TCE utilizando o cateter de Fogarty 4 Fr na região epidural e, embora haja a necessidade de outros estudos, a sonda uretral flexível demonstra ser um método alternativo de mensuração da PIC em coelhos com trauma cranioencefálico.

Tetrasubstituted cyclopentadienones as suitable enantiopure ligands with axial chirality

A series of thermally stable atropisomeric phencyclones has been successfully synthesized as ligands in new ruthenium-based enantioselective hydrogenation catalysts.

Gemistocytic astrocytoma in the spinal cord in a dog: a case report

ABSTRACT This paper reports a case of a rare variant of the cervical spinal cord astrocytoma diagnosed in a dog with progressive neurological signs, initially asymmetrical, not ambulatory tetraparesis, segmental reflexes and normal muscle tone in all four limbs and absence of pain upon palpation of the cervical spine. Myelography revealed attenuation of the ventral and dorsal contrast line in the third region of the fifth cervical vertebra. At necropsy intramedullary cylindrical mass that stretched from the third to the sixth cervical vertebra, which replaced all the gray matter of the spinal cord was observed. In the histological study, there was the replacement of the substance by neoplastic cells mantle arranged loosely. The cells were large and slightly rounded. The eosinophilic cytoplasm was well defined, sometimes forming processes interconnecting cells. The nucleus was eccentric, round, oval or kidney-shaped, and the nucleolus was evident. Thus, the microscopic changes observed in the cervical spinal cord were consistent with gemistocytic astrocytoma.

Gquest: modeling patient questionnaires and administering them through a mobile platform application

BACKGROUND

The use of surveys is becoming popular in the health care industry for acquiring information useful to the accomplishment of several studies. Besides their exploitation on a large scale for conducting epidemiological studies, surveys are being increasingly carried out on a narrower perspective through the administration of questionnaires aimed at assessing the quality of life perceived by patients or their clinical status during mid- or long-term treatments. This is useful for managing resources or optimizing and individualizing treatments.

OBJECTIVES

This paper describes Gquest, a platform for modeling, generating and administering questionnaires through mobile devices such as smartphones or tablets. Gquest was motivated by the need of administering questionnaires during home treatments, albeit its applicability is rather general. The main requirement was to have a very simple, clean and easy to use platform able to support (a) physicians in the design and delivery of questionnaires and (b) outpatients in sending self-recorded outcomes to the clinical staff.

METHODS

Gquest has two basic components. The first one is a model devised for representing questionnaires which is extremely flexible. It allows the generation of questions and answers of different types, supports adaptivity in the dialog with the user and enforces simple consistency rules for checking his input. The second component is an application able to run instances of those questionnaires. It downloads questionnaires over the air in terms of XML files from a server and stores them locally into the mobile repository. Questionnaires become then available to the user, who in our case is a patient or one of his relatives. The user can select which one to fill-in, according to his needs and/or the specific treatment protocol. The selected questionnaire may be filled-in all at once or be completed in subsequent steps over time since any input provided is persisted on a local database. Finally, when a questionnaire is closed all the answers are transparently synchronized to a server for further evaluation or statistical purposes.

RESULTS

The platform has been exploited and tested in two medical domains where questionnaires have very different purposes; a quality of life pilot survey involving patients with atrial fibrillation within the EU-funded project MobiGuide, and an investigation of the users' needs during the requirements elicitation phase of a telemedicine project for the safe discharge of fragile patients.

CONCLUSIONS

Gquest proved to be a suitable tool for dealing with a wide variety of question types and has been positively accepted by the patients enrolled in the pilot study.

Heating produced by therapeutic ultrasound in the presence of a metal plate in the femur of canine cadavers

The present study aimed to assess the heat generated by a therapeutic ultrasound (TUS) in a metal bone plate and adjacent structures after fixation to the femur of canine cadavers. Ten pairs of hind limbs were used, and they were equally distributed between groups that were subjected to 1- and 3-MHz frequencies, with each frequency testing 1- and 2-W/cm² intensities. The right hind limb was defined as the control group (absence of the metal plate), and the left hind limb was the test group (presence of the metal plate). Therefore, the control groups (CG) were denominated CGI, using TUS with 1-MHz frequency and 1-W/cm² intensity; CGII, using 1-MHz frequency and 2-W/cm² intensity; CGIII, using 3-MHz frequency and 1-W/cm² intensity; and CGIV, using 3-MHz frequency and 2-W/cm² intensity. For each control group, its respective test group (TG) was denominated TGI, TGII, TGIII and TGIV. The TUS was applied to the lateral aspect of the thigh using the continuous mode and a 3.5-cm² transducer in a 6.25-cm² area for 2 minutes. Sensors were coupled to digital thermometers that measured the temperature in different sites before (t0) and after (t1) of the TUS application. The temperatures in t1were higher in all tested groups. The intramuscular temperature was significantly higher (P<0.05) in the groups used to test the 3-MHz frequency in the presence of the metal plate. The therapeutic ultrasound in the continuous mode using frequencies of 1 and 3 MHz and intensities of 1 and 2 W/cm2 for 2 minutes caused heating of the metal plate and adjacent structures after fixation to the femur of canine cadavers.

Thermodynamic and kinetic investigation of monoketo-aldehyde-peroxyhemiacetal (MKA), a stereolabile degradation product of dihydroartemisinin

Theβ⇆αepimerization process ofMKAhas been studied under a thermodynamic and kinetic point of view in several solvents. LSER analyses and molecular modeling calculations allowed an effective rationalization of the findings.

Concentração plasmática de diclofenaco sódico em cães, submetidos à fonoforese

Com o objetivo de avaliar a concentração plasmática de diclofenaco sódico (DS) emulgel em cães com ou sem o uso de fonoforese e de verificar se a fonoforese induz à maior absorção desse fármaco, foram utilizados cinco cães, e todos eles passaram por oito grupos distintos. Um grupo recebeu, via oral, um comprimido de DS, 40mg, por animal, e sete grupos receberam aplicação transdérmica de diclofenaco sódico emulgel por ultrassom. Pela via transdérmica, a área de aplicação era de 20cm². A frequência do ultrassom foi de 1MHz, modo contínuo, com intensidade de 0,4Wcm-2. Colheram-se amostras de sangue antes de se executarem os protocolos - tempo zero -, após uma hora - tempo 1 - e após quatro horas da aplicação - tempo 2 - em todos os grupos, e realizou-se análise das amostras por cromatografia líquida de alta eficiência. Houve diferença (P<0,05) apenas nas amostras no tempo 1 do grupo que recebeu dose oral de DS em relação às outras amostras. Não foi possível verificar concentração plasmática de diclofenaco sódico com aplicação tópica em cães submetidos ou não à fonoforese, apenas quantificou-se o diclofenaco sódico pela administração via oral. A facilitação da penetração transdérmica pelo ultrassom não foi verificada sob o protocolo especificado nesta pesquisa.

Temperatura de polimerização da resina acrílica odontológica na medula espinhal de ratos Wistar

Objetivou-se investigar se a temperatura de polimerização da resina acrílica odontológica ocasiona sinais neurológicos e alteração histológica na medula espinhal de ratos. Foram utilizados 48 ratos, Wistar, distribuídos em dois grupos denominados GI ou cimento ósseo (controle positivo) e GII ou resina acrílica odontológica. Cada grupo foi redistribuído em seis subgrupos, de acordo com a quantidade do composto, o tempo de pós-operatório e o local de aferição da temperatura. O cimento ósseo ou a resina acrílica odontológica foram moldados e colocados sobre as lâminas ósseas dorsais e os processos espinhosos das vértebras L1 e L2. A temperatura de polimerização do composto foi aferida a cada 10 segundos. A temperatura máxima de polimerização e a diferença entre a temperatura externa e a interna ao canal vertebral foram maiores nos subgrupos que receberam 10 gramas. Não foi observada alteração neurológica em nenhum dos animais deste estudo. Na análise histológica, foi observada reação inflamatória de intensidade variável na meninge e no parênquima medular. Pode-se concluir que a temperatura de polimerização da resina acrílica odontológica nas quantidades de um e 10 gramas provoca alterações histológicas na meninge e no parênquima medular, sem ocasionar sinais neurológicos em ratos.

Immediate physical therapy in dogs with rupture of the cranial cruciate ligament submitted to extracapsular surgical stabilization

The study evaluated the influence of immediate physical therapy on the functional recovery of hind limbs of dogs with experimental cranial cruciate ligament rupture which underwent surgical extracapsular stabilization as well as to verify its interference in joint stability. Eight dogs were randomly divided into two groups: GI (control) (n=4) and GII (physical therapy) (n=4). The dogs in GII underwent the following therapeutic treatments in the postoperative period: cryotherapy, passive joint movement, massage, passive straightening, neuromuscular electrical stimulation, hydrotherapy (bath and aquatic mat) and therapeutic exercises. We performed evaluations of the thigh circumference, goniometry, X-ray, and knee stability (drawer test). Results did not demonstrate a significant difference between the groups nor between different post-operative times. Regarding gait analysis, we found that the 4 dogs in GI remained in degree 3 of lameness 45 and 90 days postoperatively. However, in GII, one dog remained in degree 3 45 and 90 days after surgery; one dog changed from degree 3 to 4 90 days after surgery and the other 2 dogs changed from degree 3 to 5 90 days after surgery. It is possible to conclude that dogs with CCL rupture that undergo immediate physical therapy demonstrate better results in regards to functional gait recovery. The therapeutic modalities used in the immediate post-operative period did not cause instability of the operated knee. Further studies are needed with a larger number of dogs to indicate the immediate physical therapy in dogs with CCL ligament rupture which underwent extracapsular stabilization.

Recuperação funcional em cães com doença do disco intervertebral toracolombar sem percepção à dor profunda: 37 casos (2002-2010)

O objetivo deste trabalho foi avaliar a recuperação funcional de 37 cães com diagnóstico de doença do disco intervertebral (DDIV) toracolombar, sem percepção da dor profunda superior a 48 horas e não submetidos ao tratamento cirúrgico. Os dados identificados foram: raça, idade, sexo, localização da lesão, perda da percepção da dor profunda, duração dos sinais clínicos, recuperação funcional, retorno da percepção da dor profunda, recidivas, eutanásias ou morte. Foi observada recuperação funcional em 11 cães (55%), sendo seis deles entre 30 e 60 dias após o início dos sinais clínicos. Dos onze cães que tiveram recuperação funcional satisfatória, dois (18%) não tiveram retorno da percepção à dor profunda. Pode-se concluir que cães com diagnóstico de DDIV sem percepção à dor profunda superior a 48 horas e não submetidos ao tratamento cirúrgico podem apresentar recuperação funcional satisfatória e são necessários, no mínimo, 30 dias do início dos sinais clínicos para estabelecer um prognóstico quanto ao retorno dos movimentos voluntários.

Repeat adverse events long after percutaneous coronary revascularization in diabetics

AIM

Diabetics with coronary artery disease face a high risk of adverse events following coronary revascularization. However, recurrence rates of after the first revascularization have never been appraised. The aim of this study was to evaluate recurrent events in diabetics undergoing percutaneous coronary intervention (PCI) in the current era.

METHODS

Authors collected baseline and outcome data of consecutive type-2 diabetics treated with PCI (July 2002-December 2005) . End-points of interest were the long-term rates of major adverse cardiac events (MACE: cardiac death, myocardial infarction [MI], percutaneous target vessel revascularization [TVR-PCI], or coronary artery bypass grafting [CABG]), non-TVR PCI, and stent thrombosis.

RESULTS

A total of 429 diabetics were included, 191 (44%) insulin-dependent, with drug-eluting stents implanted in 232 (54%). After a median of 38 months, events were as follows: MACE in 167 (38.9%) subjects, cardiac death in 38 (8.8%), MI in 42 (9.8%), TVR-PCI in 130 (30.3%), CABG in 11 (2.6%), non-TVR-PCI in 52 (12.1%), and definite stent thrombosis in 9 (2.1%). Among the 129 patients undergoing TVR-PCI as first event, as many as 28 (21.7%) underwent a second TVR-PCI, 7 (5.4%) underwent a third TVR-PCI, and a further 2 (1.5%) underwent a fourth TVR-PCI, whereas CABG was performed in 2 (1.5%) and non-TVR-PCI in 4 (3.1%).

CONCLUSIONS

This work, originally reporting on the risk of recurrent repeat revascularization events among diabetics treated with PCI, showed that adverse events occur frequently in these patients, but can be managed in most cases safely and successfully by means of repeat PCI only.

Activity of ectonucleotidases and adenosine deaminase in rats exposed to cigarette smoke

Cigarette smoke is a complex mixture of various toxic substances that are capable of initiating oxidative damage and promoting blood platelet alterations. In this study, we investigated the activities of the ectoenzymes NTPDase (ectonucleoside triphosphate diphosphohydrolase, CD39) and 5'-nucleotidase (CD73) in platelets as well as adenosine deaminase (ADA) in the plasma of rats exposed to aged and diluted sidestream smoke during 4 weeks. The rats were divided into two groups: I (control) and II (exposed to smoke). After the exposure period, blood was collected and the platelets and plasma were separated for enzymatic assay. The results demonstrated that NTPDase (with ATP as substrate) and 5'-nucleotidase (AMP as substrate) activities were significantly higher in group II (p < 0.05) as compared to group I, while no significant difference was observed for NTPDase with ADP as substrate. The ADA activity was significantly reduced in group II (p < 0.05) as compared with group I. Platelet aggregation was significantly increased in group II (p < 0.05) as compared with group I. We suggest that these alterations in the activity of enzymes from the purinergic system are associated with an increase in platelet aggregation. However, our study has demonstrated that the organism tries to compensate for this enhanced aggregation by increasing hydrolysis of AMP and reducing hydrolysis of adenosine, a potent inhibitor of aggregation and an important modulator of vascular tone.

Estimulação elétrica neuromuscular em cães com atrofia muscular induzida

Empregou-se a estimulação elétrica neuromuscular (EENM) de baixa freqüência no músculo quadríceps femoral de cães com atrofia induzida e avaliou-se a ocorrência de ganho de massa nessa musculatura. Foram utilizados oito cães com pesos entre 15 e 30kg, distribuídos aleatoriamente em dois grupos denominados de I ou controle e II ou tratado. A articulação femorotibiopatelar esquerda foi imobilizada por 30 dias pelo método de transfixação percutânea tipo II, com retirada de aparelho de imobilização após esse período. Decorridas 48 horas da remoção, foi realizada a EENM nos cães do grupo II, cinco vezes por semana, com intervalo de 24 horas cada sessão, pelo período de 60 dias. Foram avaliadas a circunferência da coxa, a goniometria do joelho, a análise clínica da marcha, as enzimas creatina-quinase (CK) e aspartato-amino-transferase (AST) e a morfometria das fibras musculares em cortes transversais do músculo vasto lateral colhido mediante biópsia muscular. A EENM foi empregada no músculo quadríceps femoral na freqüência de 50Hz, duração de pulso de 300 milisegundos e relação de tempo on/off de 1:2. Quanto à morfometria das fibras do músculo vasto lateral, no grupo tratado houve aumento significativo (P<0,05) da área transversal aos 90 dias em relação ao dia zero. A EENM de baixa freqüência ocasiona hipertrofia do músculo vasto lateral em cães após a imobilização rígida temporária da articulação do joelho.

Nódulos fibro-histiocíticos no baço de uma cadela: relato de caso

Descreve-se a ocorrência de múltiplos nódulos fibro-histiocíticos no baço de uma cadela Rottweiler, de sete anos. O diagnóstico foi feito por histopatologia e confirmado por imunoistoquímica positiva para ED1, CD18, vimentina e lisozima. O animal foi sacrificado três meses após o diagnóstico, por severo agravamento dos sinais clínicos.

Identification of an isomer impurity in piperaquine drug substance

A significant contaminant of the antimalarial drug piperaquine (1,3-bis-[4-(7-chloroquinolyl-4)-piperazinyl-1]propane) has been identified using liquid chromatography-mass spectrometry (LC-MS) and 2D NMR spectroscopy (1H-1H COSY, 1H-13C HSQC, 1H-13C HMBC). The impurity was identified as the positional isomer 1-[(5-chloroquinolin-4)-piperazinyl]-3-[(7-chloroquinolin-4)-piperazinyl]propane. The impurity is formed because of contamination of batches of 4,7-dichloroquinoline (a precursor in the synthesis of piperaquine) with 4,5-dichloroquinoline. The amount of impurity (peak area impurity/peak area piperaquine using LC-UV at 347 nm) in old batches of piperaquine and in Artekin (the combination of dihydroartemisinin-piperaquine) ranged from 1.5 to 5%.

Acetylcholinesterase Activity in Rats Experimentally Demyelinated with Ethidium Bromide and Treated with Interferon Beta

The ethidium bromide (EB) demyelinating model was associated with interferon beta (IFN-beta) to evaluate acetylcholinesterase (AChE) activity in the striatum (ST), hippocampus (HP), cerebral cortex (CC), cerebellum (CB), hypothalamus (HY), pons (PN) and synaptosomes from the CC. Rats were divided into four groups: I control (saline), II (IFN-beta), III (EB) and IV (EB and IFN-beta). After 7, 15 and 30 days rats (n = 6) were sacrificed, and the brain structures were removed for enzymatic assay. AChE activity was found to vary in all the brain structures in accordance with the day studied (7-15-30 days) (P < 0.05). In the group III, there was an inhibition of the AChE activity in the ST, CB, HY, HP and also in synaptosomes of the CC (P < 0.05). It was observed that IFN-beta per se was capable to significantly inhibit (P < 0.05) AChE activity in the ST, HP, HY and synaptosomes of the CC. Our results suggest that one of the mechanisms of action of IFN-beta is through the inhibition of AChE activity, and EB could be considered an inhibitor of AChE activity by interfering with cholinergic neurotransmission in the different brain regions.

Apyrase and 5'-nucleotidase activities in synaptosomes from the cerebral cortex of rats experimentally demyelinated with ethidium bromide and treated with interferon-beta

Apyrase and 5'-nucleotidase activities were analyzed in an ethidium bromide (EB) demyelinating model associated with interferon-beta (IFN-beta). The animals were divided in groups: I, control (saline); II, saline and IFN-beta; III, EB and IV, EB and IFN-beta. After 7, 15 and 30 days the animals (n = 5) were sacrificed and the cerebral cortex was removed for synaptosome preparation and enzymatic assays. Apyrase activity using ATP as substrate increased in groups II, III and IV (P < 0.001) after 7 days and in groups III and IV (P < 0.001) after 15 days. Using ADP as substrate, an activation of this enzyme was observed in group III (P < 0.05) after seven and 15 days. The 5'-nucleotidase activity increased in group III (P < 0.05) after 7 days and in groups II, III and IV (P < 0.001) after 15 days. After 30 days treatment, no significant alteration was observed in enzyme activities. Results showed that apyrase and 5'-nucleotidase activities are altered in demyelination events and that IFN-beta was able to regulate the adenine nucleotide hydrolysis.

Analgesia epidural com clonidina ou romifidina em cães submetidos à cirurgia coxofemoral

Avaliaram-se as alterações cardiorrespiratórias e a analgesia da administração epidural de clonidina ou romifidina em cães submetidos à cirurgia coxofemural. Foram utilizados 14 cães distribuídos em dois grupos: o grupo Cloni recebeu 150µg de clonidina e o grupo Romi, 20µg/kg de romifidina. A indução anestésica foi realizada com propofol e a anestesia cirúrgica mantida com halotano e O2 em respiração espontânea. A punção do espaço epidural foi feita logo após a indução. Antes da indução e a cada 10 minutos foram avaliadas as freqüências cardíaca e respiratória, a pressão arterial sistólica, a saturação de oxigênio da hemoglobina e a concentração de halotano. Após indução e ao término do procedimento cirúrgico coletou-se sangue arterial para avaliação gasométrica de pH, PaCO2, PaO2, SaO2, BE e HCO3-. Foi realizada avaliação pós-operatória do grau de analgesia (intensa, pouco intensa e inadequada) nas primeiras duas horas após término da cirurgia. Os animais do grupo Romi apresentaram bradicardia, bradiarritmias e hipertensão. A freqüência cardíaca e a pressão arterial sistólica no grupo Cloni mantiveram-se dentro da faixa de variação fisiológica para a espécie. A analgesia trans-operatória foi considerada intensa nos dois grupos. A administração epidural de clonidina ou romifidina produziu intensa analgesia transcirúrgica sem depressão respiratória e pouco intensa analgesia pós-operatória por duas horas

Hernioplastia diafragmática em cão com pericárdio bovino conservado em solução supersaturada de açúcar

Foram utilizados sete cães adultos, três machos e quatro fêmeas, sem raça definida, com pesos entre 10 e 22kg, para avaliação do processo cicatricial do músculo diafragma, na presença do implante de pericárdio bovino conservado em solução supersaturada de açúcar a 300%. Foi criado um defeito na porção muscular do hemidiafragma esquerdo de dimensões 8,0×5,0cm. Após a toracotomia no oitavo espaço intercostal esquerdo, o implante heterógeno foi fixado com fio poliamida nº 3-0 por meio de sutura simples contínua. Decorrido o período pré-estabelecido de pós-operatório, os animais foram submetidos a exames radiográficos simples e contrastado e a estudos macroscópico e histológico. Na avaliação radiográfica, foi verificada presença das silhuetas diafragmática e cardíaca, sem evidências de vísceras abdominais no interior do tórax. Macroscopicamente, notou-se a formação de tecido conjuntivo fibroso semi-transparente que ocluia o defeito diafragmático. O segmento de pericárdio bovino conservado em solução supersaturada de açúcar a 300%, em temperatura ambiente, é substituído por uma fina camada de tecido conjuntivo fibroso e promove a restauração do defeito no músculo diafragma de cão.

Bone mineral density and bone metabolism in Duchenne muscular dystrophy

Very few studies on bone mineral density and bone metabolism in Duchenne muscular dystrophy (DMD) have been reported. DMD is a severe, progressive muscular disease resulting in death at a young age. No specific therapies are available, but corticosteroids induce improvement and slower progression of the disease. However, long-term steroid therapy is a serious risk factor for osteoporosis. This study was aimed at evaluating bone mineral density and calciotropic hormones in a group of children affected by DMD, with or without steroid therapy. Bone mineral density was measured by DXA scan on lumbar spine and total body. Evaluation of calcium, phosphorus, bone turnover markers and calciotropic hormones was performed. Thirty-two children affected by DMD were studied: twenty-two on long-term prednisone therapy, ten not taking corticosteroids. Bone mineral density was lower than normal for age in all patients, and even lower in the group of steroid-treated children. Trunk and lower limb bone mineral densities were more reduced than upper limb mineral density, especially in the steroid-treated subjects. A marked reduction in spine bone mineral density, hypocalciuria, low 25-hydroxyvitamin D levels, and increased bone turnover markers were observed, and even these especially in the steroid-treated group. In conclusion, decreased bone mineral density and derangement of calcium metabolism were present in DMD patients, and were worsening during corticosteroid therapy. It is thus recommended that bone and mineral metabolism be carefully evaluated in patients with DMD, so that appropriate measures could be taken, especially now that chronic corticosteroid therapy is frequently given.

Conformational studies by dynamic NMR. 84.(1) structure, conformation, and stereodynamics of the atropisomers of N-aryl-tetrahydropyrimidines

The existence of stereolabile atropisomers for a number of N-aryl-tetrahydropyrimidines in solution has been deduced from the observation of the anisochronous NMR signals of prochiral methylene groups. The interconversion barriers for these atropisomers have been measured by line shape analysis of dynamic NMR spectra at various temperatures: a Molecular Mechanics modeling resulted in good agreement with these values. In an appropriate case, distinct NMR signals for the two enantiomeric forms could be observed at ambient temperature in a chiral environment. Evidence was also obtained for an exchange process occurring between two conformers experiencing a very biased equilibrium. Single-crystal X-ray diffraction of one such compound yielded a molecular structure in good agreement with the results obtained by ab initio calculations.

Conformational studies by dynamic NMR. 83. Correlated enantiomerization pathways for the stereolabile propeller antipodes of dimesityl substituted ethanol and ethers

Below -100 degrees C, the NMR spectra of dimesityl derivatives of ethanol and of various ethers reveal how these molecules exist as M and P propeller-like stereolabile enantiomers, owing to the restricted rotation about the Ar-C bond. Single-crystal X-ray diffraction of one such derivative confirmed the existence of a two-blade propeller structure. Computer analysis of the NMR line shape allowed the barriers for the enantiomerization process to be determined. Theoretical modeling (Molecular Mechanics) of the interconversion circuit produced good agreement between the computed and experimental barrier for a correlated dynamic process where a disrotatory one-ring flip pathway reverses the helicity of the conformational enantiomers. Introduction of a configurationally stable chiral center allowed two distinct NMR spectra to be detected at appropriate low temperature for two stereolabile diastereoisomers.

Solvent-free asymmetric aminoalkylation of electron-rich aromatic compounds: stereoselective synthesis of aminoalkylnaphthols by crystallization-induced asymmetric transformation

Electron-rich aromatic compounds such as 2-naphthol give a faster and asymmetric 1-aminoalkylation with high yields when treated with (R)-1-phenylethylamine and aromatic aldehydes in solvent-free conditions. An asymmetric transformation of a second kind, probably induced by the preferential crystallization of one diastereomer, affords the straightforward and stereoselective synthesis of aminoalkylnaphthols. Mechanisms predictable for this asymmetric reaction are reported. The absolute configurations and the conformations of the unknown aminonaphthols are widely ascertained.