Parametric Study of Pulsed Field Ablation With Biphasic Waveforms in an In Vivo Heart Model: The Role of Frequency.

BACKGROUND: Pulsed field ablation (PFA) is a novel nonthermal cardiac ablation technology based on irreversible electroporation. Unfortunately, the characteristics of the electric field waveforms used in clinical and experimental PFA are not typically reported. This study examines the effect of the frequency of biphasic waveforms and compares biphasic to monophasic waveforms. METHODS: A total of 29 Sprague-Dawley rats were treated with PFA using an epicardial monopolar electrode. Biphasic waveforms with three different frequencies, 90, 260, and 450 kHz (10 bursts of 100 µs duration at 500 V or 800 V) and monophasic waveforms (10 pulses of 100 µs duration at 500 V) were studied. Collateral neuromuscular stimulation and temperature increase in the point of application were directly measured. Lesion formation was assessed 3 weeks after treatment by histopathologic analysis. Computer simulations were used to estimate the electric field lethal threshold for each condition. A previous in vitro study was performed to draw a complete characterization of the studied dependencies. RESULTS: Morphometric analysis demonstrated a significant association between chronic lesion size and waveform characteristics. For the same voltage level, monophasic waveforms yielded the largest lesions compared with any of the biphasic protocols (P<0.05). Increasing PFA frequency was associated with reduced neuromuscular stimulation but also with reduced ablation efficacy. Maximum absolute temperature increase recorded along a complete treatment was 3 °C. Vascular structures inside the lesions were preserved for all conditions. Computer simulation-based analysis showed that waveform frequency had a graded effect on the lethal electric field threshold, with threshold of 600 V/cm for monophasic waveforms versus 2000 V/cm for biphasic waveforms with a frequency of 450 kHz. CONCLUSIONS: Frequency is a major determinant of efficacy in biphasic PFA. Our results highlight the critical need of disclosing waveform characteristics when reporting the results of different PFA systems.

Oral submucous fibrosis presenting with histopathological lichenoid changes as predominant feature: Report of five cases and review of the literature.

Oral submucous fibrosis (OSF) is a precancerous condition of the oral cavity associated with habitual chewing of quid, with a high incidence among populations of the Indian subcontinent and Southeast Asia. Clinically, its initial manifestation may mimic oral lichen planus or lichen sclerosus. If the habit is not halted, the mucosa gets leathery and thickened, and fibrous bands form causing significant morbidity. Microscopically, it is characterized by atrophic epithelium, loss of rete ridges, and hyalinization of lamina propria. Of note, these hallmark histopathological features may be overlooked in the unusual presence of lichenoid interface changes, which may lead to the wrong diagnosis. We present herein five cases in which the rare joint appearance of OSF and lichenoid reaction features posed a diagnostic challenge. Due to its progressive nature and malignant potential, the presence of oral lichenoid changes overlying submucous hyalinization, in the right clinical and demographic setting, should raise suspicion of OSF and prompt actions directed at quid-chewing discontinuation.

Thermoliquefaction of palm oil fiber (Elaeis sp.) using supercritical ethanol.

Thermoliquefaction of palm oil fiber was investigated using supercritical ethanol as solvent. A semi-continuous laboratory scale unit was developed to investigate the effects of temperature (300-500°C), heating rate (10-30°C.min-1) and cracking time (10-30min) on the conversion of biomass in bio-oil. The main advantage of the proposed process is that a pure solvent is pumping through the reactor that contains the biomass, dispensing the use of biomass slurries. The yield of bio-oil ranged from 56% to 84%, depending on the experimental conditions. It was observed that an increase in working temperature led to an increase in the bio-oil production. Cracking time and heating rate variation had not shown a considerable effect on the conversion of biomass. The chemical profiles of bio-oil determined by GC/MS, indicate that at low temperature mainly sugar derivatives are produced, while at higher temperatures alcohols and phenolic are the majority compounds of the bio-oil.

Maternal-child nutrition practices and pediatric overweight/obesity in the United States and Chile: a comparative study.

Childhood overweight/obesity is now epidemic in both developed countries and those undergoing economic transition. This study compared maternal and school-age child nutrition practices and body mass index in the United States and in Chile. Children (125 in the United States, 121 in Chile) and their mothers (116 in the United States, 101 in Chile) participated. Findings indicated that child nutrition practices were comparable, but mothers in the U.S. group demonstrated fewer healthy nutrition practices on behalf of their children. Significant associations were found between maternal and child nutrition practices. Substantially more children in the U.S. sample were overweight/obese. Implications for practice are presented.

Clinical features associated with treatment response in obsessive-compulsive disorder.

OBJECTIVE: This study aims to investigate the effect of sociodemographic and clinical features on the short-term response to pharmacological treatment in obsessive-compulsive disorder (OCD). We focused especially on investigating factors previously associated with poorer prognosis, such as comorbidity with tic disorders, early onset of symptoms, and sensory phenomena preceding compulsions, which have been described as common in both tic-related and early-onset OCD. METHOD: The study involved 41 consecutive adult patients with OCD diagnosed according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria and was conducted at the OCD Spectrum Disorders Clinic of the University of Sao Paulo School of Medicine in São Paulo, Brazil, between January of 2000 and December of 2001. All patients were treated exclusively with oral clomipramine for 14 weeks. Treatment response, measured for Yale-Brown Obsessive-Compulsive Scale score decrease from baseline, was assessed by an investigator blinded as to the variables of interest present. RESULTS: Linear regression analysis showed that having a partner and sensory phenomena preceding compulsions were associated with better response to clomipramine treatment (P = .04 and P = .002, respectively). Tic comorbidity and early onset of symptoms were not associated with poorer response. CONCLUSIONS: In OCD, having a partner and sensory phenomena preceding compulsions seem to be associated with a favorable response to pharmacological treatment.

Adaptive, emotional, and family functioning of children with obsessive-compulsive disorder and comorbid attention deficit hyperactivity disorder.

OBJECTIVE: The purpose of the study was to examine adaptive, emotional, and family functioning in a well-characterized group of children and adolescents with obsessive-compulsive disorder (OCD) and to evaluate the influence of comorbid attention deficit hyperactivity disorder (ADHD) on the levels of impairment in various functional domains. METHOD: The study group included 287 children and adolescents (191 boys, 96 girls) ages 7-18 years. Fifty-six subjects had a diagnosis of OCD only, 43 had both OCD and ADHD, 95 had ADHD, and 93 were unaffected comparison children. Best estimate DSM-IV diagnoses were assigned on the basis of structured interviews and clinical ratings. The children's functioning was evaluated with a comprehensive battery of well-established, standardized measures, including the Vineland Adaptive Behavior Scales, parents' ratings of social and family functioning, and children's self-reports of emotional adjustment. RESULTS: The children with OCD only were more impaired than were unaffected comparison subjects in most areas of adaptive functioning and emotional adjustment. Children with OCD plus ADHD had additional difficulties in social functioning, school problems, and self-reported depression. Impairment in daily living skills, reduced number of activities, and self-reported anxiety were uniquely associated with the diagnosis of OCD. Family dysfunction was associated with ADHD but not with OCD. CONCLUSIONS: Children and adolescents with OCD are impaired in multiple domains of adaptive and emotional functioning. When comorbid ADHD is present, there is an additional burden on social, school, and family functioning.

[Air temperature elevation as an alternative for the control of deltamethrin-resistant Triatoma infestans (Hemiptera, Reduviidae)]. / La aerotermia como alternativa para el control de Triatoma infestans (Hemiptera, Reduviidae) resistentes a deltametrina.

This study explores the effects of artificial air temperature elevation on the embryonic, nymphal, and adult forms of deltamethrin-resistant Triatoma infestans. In the laboratory, complete offspring of T. infestans were exposed to increasing air temperatures to determine the viability of eggs and survival of nymphs and adults; in the field, the experiment was conducted in a poor rural dwelling previously identified as infested with the vector. The laboratory phase showed 100% non-viability of eggs and 100% mortality of nymphs and adults exposed to airtight temperatures from 45 degrees C to 55 degrees C, while the field phase succeeded in reproducing the heat's ovicidal effect and negative conversion of entomological assays in the experimental dwelling, as conducted over the course of 72 hours at 30, 60, and 90 days from the baseline evaluation. Artificial elevation of airtight temperature on dwellings proved to be an acceptable, harmless, and technically simple control method.

La aerotermia como alternativa para el control de Triatoma infestans (Hemiptera, Reduviidae) resistentes a deltametrina / Air temperature elevation as an alternative for the control of deltamethrin-resistant Triatoma infestans (Hemiptera, Reduviidae)

Se exploraron los efectos de la elevación artificial de la temperatura del aire sobre las formas embrionarias, ninfales y adultas de Triatoma infestansresistentes a Deltametrina. En laboratorio, se expuso a temperaturas crecientes del aire la progenie completa de T. infestans, para determinar viabilidad de huevos y supervivencia en ninfas y adultos; sobre el terreno, la experimentación se llevó a cabo en una vivienda tipo rancho previamente evaluada como colonizada. Durante la fase de laboratorio se comprobó la inviabilidad del 100 por ciento de los huevos y la mortalidad del 100 por ciento de las ninfas y adultos expuestos a temperaturas del aire estanco de entre 45ºC y 55ºC, mientras que en la fase de terreno se logró reproducir el efecto ovicida del calor, como así también la negativización de las evaluaciones entomológicas de la vivienda de experimentación, llevadas a cabo a las 72 horas, a los 30, 60 y 90 días. La elevación artificial de la temperatura del aire estanco en las habitaciones resultó ser un método de control de eficacia aceptable, inocuo y técnicamente sencillo.

[The neurobiological bases of obsessive-compulsive disorder and Tourette syndrome]. / As bases neurobiológicas do transtorno obsessivo-compulsivo e da síndrome de Tourette.

OBJECTIVE: To describe and discuss evidence-based articles on the neurobiology of obsessive-compulsive disorder and Tourette syndrome. SOURCES OF DATA: A review of the most relevant papers on the phenomenology, neuroanatomy, neuroimaging, genetic and immunological aspects of these two disorders was performed. SUMMARY OF THE FINDINGS: Ritualistic behaviors and repetitive thoughts have been extensively studied in the last years. The definitions of obsessive-compulsive disorder and Tourette syndrome emphasize the existence of a continuum of symptoms, with high prevalence in the general population. Neurobiological findings have implicated genetic and immunological factors in the etiology of these two disorders. CONCLUSIONS: Advances in neuroscience triggered genetic and immunological research studies, allowing new perspectives on the treatment of obsessive-compulsive disorder and Tourette syndrome patients.

As bases neurobiológicas do transtorno obsessivo-compulsivo e da síndrome de Tourette / The neurobiological bases of obsessive-compulsive disorder and Tourette syndrome

OBJETIVO: Revisar as teorias e evidências das bases neurobiológicas do transtorno obsessivo-compulsivo e da síndrome de Tourette. FONTES DOS DADOS: Revisão dos estudos que investigam a neuroanatomia, neuroimagem, genética e imunologia desses transtornos. SíNTESE DOS DADOS: Os comportamentos ritualísticos e pensamentos repetitivos têm sido cada vez mais estudados em nosso meio. As definições dessas entidades formam um continuum espectral de sintomas com prevalência significativa na população. CONCLUSÕES: Os avanços das neurociências possibilitaram a exploração dos aspectos genéticos do sistema nervoso central e seu funcionamento, fornecendo novas perspectivas para o tratamento de pacientes com transtorno obsessivo-compulsivo e síndrome de Tourette.

Impact of age at onset and duration of illness on the expression of comorbidities in obsessive-compulsive disorder.

BACKGROUND: Obsessive-compulsive disorder (OCD) patients usually experience comorbidities including tics, trichotillomania, body dysmorphic disorder, and mood and anxiety disorders. The present report verifies how age at onset of obsessive-compulsive symptoms and duration of illness are associated with comorbid diagnoses in OCD patients. METHOD: Psychiatric comorbidity was assessed using a structured clinical interview in 161 consecutive outpatients referred for treatment between 1996 and 2001 who met DSM-IV criteria for OCD. Age at onset and duration of illness were retrospectively assessed by direct interviews. RESULTS: An earlier age at onset of obsessive-compulsive symptoms was associated with tic disorders, while longer illness duration was associated with depressive disorder (major depressive disorder or dysthymia) and social phobia. CONCLUSION: Age at onset and duration of OCD illness are meaningful variables affecting the expression of comorbidities in OCD. Tic disorders and OCD may share common etiologic pathways. Depressive disorders, in contrast, may be secondary complications of OCD.

Obsessive-compulsive symptom dimensions in affected sibling pairs diagnosed with Gilles de la Tourette syndrome.

Obsessive-compulsive disorder (OCD) is an etiologically heterogeneous disorder. Recent factor analyses have consistently identified several symptom dimensions, two of which are associated with increased familial risk for OCD; aggressive, sexual, and religious obsessions and checking compulsions (FACTOR 1) and symmetry and ordering obsessions and compulsions (FACTOR 2). Both of these symptom dimensions are also frequently seen in association with Gilles de la Tourette syndrome (GTS). The purpose of this study was to determine whether these obsessive-compulsive (OC) symptom dimensions are correlated within families (between sibs and between parent-child pairs). Using data collected by the Tourette Syndrome Association International Consortium for Genetics Affected Sibling Pair Study, the authors selected all available GTS sib pairs and their parents for which these OC symptom dimensions (factor scores) could be generated. This group included 128 full sibs and their mothers (54) and fathers (54). Four OC symptom dimension scores were computed for each family member using an algorithm derived from item endorsements from the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) symptom checklist. In addition to a series of univariate analyses, complex segregation analyses were also completed using these quantitative OC symptom dimension scores. FACTOR 1 and FACTOR 2 scores were significantly correlated in sib pairs concordant for GTS. The mother-child correlations, but not father-child correlations, were also significant for these two factors. Segregation analyses were consistent with dominant major gene effects for both FACTOR 1 and FACTOR 2. We conclude that familial factors contribute significantly to OC symptom dimension phenotypes in GTS families. This familial contribution could be genetic or environmental.