To clarify the risk-benefit ratio involved in association of antiarrhythmic drugs, a combined therapy of amiodarone and propafenone was tested by means of continuous electrocardiographic monitoring, analysis of levels of the drug in the plasma and programmed electrical stimulation in a selected group of 10 patients who had left ventricular dysfunction and spontaneous relapses of sustained ventricular tachycardia despite treatment with amiodarone. Induction of sustained ventricular tachycardia, possible in each case during treatment with amiodarone, was suppressed after addition of propafenone in 2 patients (responders), who had the best ejection fractions of the entire group (greater than 45%). Worsening of spontaneous tachycardias developed in 4 cases during the combined therapy. These ventricular arrhythmias, although generally at a low rate, sometimes had the potential to degenerate into ventricular fibrillation and disappeared after both discontinuation of propafenone or increase of its dosage (1 patient). Of the six cases undergoing chronic combined treatment, only the responders to premature electrical stimulation were completely protected from recurrences of arrhythmia. Three cases, on the other hand, needed permanent endocardial pacing for symptomatic bradyarrhythmias. The combination of treatment with amiodarone and propafenone, although potentially useful in limiting dosages of and toxicity from amiodarone, is frequently associated with undesirable, and occasionally has severe, side-effects. The best candidates for this pharmacological association seem to be patients without severely depressed left ventricular function who have a greater probability of not presenting the inducibility of ventricular tachycardia after the addition of propafenone to the regimen for treatment. 相似文献
People with Prader-Willi syndrome (PWS) demonstrate social dysfunction and increased risk of autism spectrum disorder, especially those with the maternal uniparental disomy (mUPD) versus paternal deletion genetic subtype. This study compared the neural processing of social (faces) and nonsocial stimuli, varying in emotional valence, across genetic subtypes in 24 adolescents and adults with PWS.
Methods
Upright and inverted faces, and nonsocial objects with positive and negative emotional valence were presented to participants with PWS in an oddball paradigm with smiling faces serving as targets. Behavioral and event-related potential (ERP) data were recorded.
Results
There were no genetic subtype group differences in accuracy, and all participants performed above chance level. ERP responses revealed genetic subtype differences in face versus object processing. In those with deletions, the face-specific posterior N170 response varied in size for face stimuli versus inverted faces versus nonsocial objects. Persons with mUPD generated N170 of smaller amplitude and showed no stimulus differentiation. Brain responses to emotional content did not vary by subtype. All participants elicited larger posterior and anterior late positive potential responses to positive objects than to negative objects. Emotion-related differences in response to faces were limited to inverted faces only in the form of larger anterior late positive potential amplitudes to negative emotions over the right hemisphere. Detection of the target smiling faces was evident in the increased amplitude of the frontal and central P3 responses but only for inverted smiling faces.
Conclusion
Persons with the mUPD subtype of PWS may show atypical face versus object processes, yet both subtypes demonstrated potentially altered processing, attention to and/or recognition of faces and their expressions. 相似文献
There is controversy as to how responses to colour in the human brain are organized within the visual pathways. A key issue is whether there are modular pathways that respond selectively to colour or whether there are common neural substrates for both colour and achromatic (Ach) contrast. We used functional magnetic resonance imaging (fMRI) adaptation to investigate the responses of early and extrastriate visual areas to colour and Ach contrast. High‐contrast red–green (RG) and Ach sinewave rings (0.5 cycles/degree, 2 Hz) were used as both adapting stimuli and test stimuli in a block design. We found robust adaptation to RG or Ach contrast in all visual areas. Cross‐adaptation between RG and Ach contrast occurred in all areas indicating the presence of integrated, colour and Ach responses. Notably, we revealed contrasting trends for the two test stimuli. For the RG test, unselective processing (robust adaptation to both RG and Ach contrast) was most evident in the early visual areas (V1 and V2), but selective responses, revealed as greater adaptation between the same stimuli than cross‐adaptation between different stimuli, emerged in the ventral cortex, in V4 and VO in particular. For the Ach test, unselective responses were again most evident in early visual areas but Ach selectivity emerged in the dorsal cortex (V3a and hMT+). Our findings support a strong presence of integrated mechanisms for colour and Ach contrast across the visual hierarchy, with a progression towards selective processing in extrastriate visual areas. 相似文献
BACKGROUND: The identification of patients with idiopathic dilated cardiomyopathy (IDC) at higher risk of sudden death (SD) is still an unsolved issue, and the role of non-sustained ventricular tachycardia (NSVT) uncertain. METHODS: The effect of NSVT on total mortality, SD and life-threatening arrhythmias was evaluated in 554 patients with IDC on optimal medical treatment and at long-term follow-up (81 +/- 58 months). RESULTS: At diagnosis, 240 patients (43%) had NSVT at Holter monitoring and 314 (57%) did not. During follow-up, 189 patients (5/100 patients-year) died or underwent heart transplantation; SD occurred in 53 patients (1.4/100 patients-year); SD + non-fatal ventricular arrhythmias occurred in 75 patients (2/100 patients-year). Patients with and without NSVT at diagnosis had the same 5-year transplant-free survival rate (76 vs 76%, p = NS) and a similar incidence of SD (10 vs 7%, p = NS). The length and rate of NSVT did not show any significant relationship with the outcome. Only heart failure symptoms (NYHA class III-IV) (hazard ratio [HR] 1.9, p = 0.015) and severe left ventricular impairment (left ventricular ejection fraction < or = 0.30 and left ventricular end-diastolic diameter > or = 70 mm) (HR 2.7, p < 0.0001) were independently associated with higher SD risk. At multivariate analysis the presence of frequent NSVT episodes (> or = 3 runs/day) was associated with an increased risk of total mortality (HR 1.68, p = 0.041) and of major ventricular arrhythmias (HR 2.11, p = 0.037), but only in the subgroup of patients with severe left ventricular impairment. CONCLUSIONS: Patients with advanced heart failure symptoms, severe left ventricular dysfunction and dilation had a higher risk of SD independently of NSVT. The finding of more frequent NSVT was associated with an increased risk of all-cause mortality and of major ventricular arrhythmias in patients with severe left ventricular impairment. 相似文献
Culture-based studies have shown that Streptococcus mutans and lactobacilli are associated with root caries (RC). The purpose of the present study was to assess the bacterial diversity of RC in elderly patients by use of culture-independent molecular techniques and to determine the associations of specific bacterial species or bacterial communities with healthy and carious roots. Plaque was collected from root surfaces of 10 control subjects with no RC and from 11 subjects with RC. The bacterial 16S rRNA genes from extracted DNA were PCR amplified, cloned, and sequenced to determine species identity. From a total of 3,544 clones, 245 predominant species or phylotypes were observed, representing eight bacterial phyla. The majority (54%) of the species detected have not yet been cultivated. Species of Selenomonas and Veillonella were common in all samples. The healthy microbiota included Fusobacterium nucleatum subsp. polymorphum, Leptotrichia spp., Selenomonas noxia, Streptococcus cristatus, and Kingella oralis. Lactobacilli were absent, S. mutans was present in one, and Actinomyces spp. were present in 50% of the controls. In contrast, the microbiota of the RC subjects was dominated by Actinomyces spp., lactobacilli, S. mutans, Enterococcus faecalis, Selenomonas sp. clone CS002, Atopobium and Olsenella spp., Prevotella multisaccharivorax, Pseudoramibacter alactolyticus, and Propionibacterium sp. strain FMA5. The bacterial profiles of RC showed considerable subject-to-subject variation, indicating that the microbial communities are more complex than previously presumed. The data suggest that putative etiological agents of RC include not only S. mutans, lactobacilli, and Actinomyces but also species of Atopobium, Olsenella, Pseudoramibacter, Propionibacterium, and Selenomonas. 相似文献
To evaluate the clinical value of combining one-view mammography (cranio-caudal, CC) with the complementary view tomosynthesis (mediolateral-oblique, MLO) in comparison to standard two-view mammography (MX) in terms of both lesion detection and characterization.
Methods
A free-response receiver operating characteristic (FROC) experiment was conducted independently by six breast radiologists, obtaining data from 463 breasts of 250 patients. Differences in mean lesion detection fraction (LDF) and mean lesion characterization fraction (LCF) were analysed by analysis of variance (ANOVA) to compare clinical performance of the combination of techniques to standard two-view digital mammography.
Results
The 463 cases (breasts) reviewed included 258 with one to three lesions each, and 205 with no lesions. The 258 cases with lesions included 77 cancers in 68 breasts and 271 benign lesions to give a total of 348 proven lesions. The combination, DBT(MLO)+MX(CC), was superior to MX (CC+MLO) in both lesion detection (LDF) and lesion characterization (LCF) overall and for benign lesions. DBT(MLO)+MX(CC) was non-inferior to two-view MX for malignant lesions.
Conclusions
This study shows that readers’ capabilities in detecting and characterizing breast lesions are improved by combining single-view digital breast tomosynthesis and single-view mammography compared to two-view digital mammography.
Key Points
? Digital breast tomosynthesis is becoming adopted as an adjunct to mammography (MX) ? DBT(MLO)+MX(CC)is superior to MX(CC+MLO)in lesion detection (overall and benign lesions) ? DBT(MLO)+MX(CC)is non-inferior to MX(CC+MLO)in cancer detection ? DBT(MLO)+MX(CC)is superior to MX(CC+MLO)in lesion characterization (overall and benign lesions) ? DBT(MLO)+MX(CC)is non-inferior to MX(CC+MLO)in characterization of malignant lesions相似文献
Increasing evidence has shown that positive affect enhances many aspects of daily functioning. Yet, how dispositional positive affect is represented in the intrinsic brain networks remains unclear. Here, we used resting-state functional Magnetic Resonance Imaging to test how trait positive and negative affect of an individual were associated with the intrinsic connectivity of brain regions within the salience and emotion network and the default mode network in 70 healthy young adults. We observed that positive affect was negatively associated with connectivity within the salience and emotion network, particularly with the bidirectional connections spanning the left anterior insula and left nucleus accumbens. For connections between the salience and emotion network and the rest of the brain, we observed that positive affect was negatively related to the connectivity between the right amygdala and the right middle temporal gyrus. Affect-based modulations of connectivity were specific to positive affect and to the salience and emotion network. Our findings highlight the critical role of salience and emotion network in the neural relations of positive affect, and lay the groundwork for future studies on modeling the connectivity of salience and emotion network to predict mental well-being.
Computer-aided diagnosis (CAD) has been extensively reported to increase sensitivity by about 10% when added to a single reading while increasing recall rate by 12%, and its current use can be safely recommended in clinical practice. CAD has been suggested as a possible alternative to conventional double reading in screening. Uncontrolled comparison is consistent and suggests that CAD is comparable to double reading in incremental cancer detection rate (CAD +10.6%, double reading +9.1%) and possibly better in recall rate (CAD +12.5%, double reading +28.8%). However, controlled studies comparing single reading + CAD to conventional double reading are not consistent and on average suggest a lower cancer detection rate (?5.1%) and a lower recall rate (?9.8%) for CAD. Scientific evidence is not sufficient for a safe recommendation of single reading + CAD as a current alternative to conventional double reading. 相似文献
PurposeWe introduce a set of dichoptic training tasks that differ in terms of (1) the presence of external noise and (2) the visual feature implicated (motion, orientation), examining the generality of training effects between the different training and test cues and their capacity for driving changes in sensory eye dominance and stereoscopic depth perception.MethodsWe randomly assigned 116 normal-sighted observers to five groups (four training groups and one no training group). All groups completed both pre- and posttests, during which they were tested on dichoptic motion and orientation tasks under noisy and noise-free conditions, as well as a binocular phase combination task and two depth tasks to index sensory eye dominance and binocular function. Training groups received visual training on one of the four dichoptic tasks over 3 consecutive days.ResultsTraining under noise-free conditions supported generalization of learning to noise-free tasks involving an untrained feature. By contrast, there was a symmetric learning transfer between the signal-noise and no-noise tasks within the same visual feature. Further, training on all tasks reduced sensory eye dominance but did not improve depth perception.ConclusionsTraining-driven changes in sensory eye balance do not depend on the stimulus feature or whether the training entails the presence of external noise. We conjecture that dichoptic visual training acts to balance interocular suppression before or at the site of binocular combination. 相似文献
BACKGROUND: Lacunar stroke (L) is the most common stroke subtype associated with vascular dementia (VaD-L). OBJECTIVE: To evaluate the cognitive and behavioral course in patients with probable VaD-L. METHODS: We longitudinally measured rates of change on MMSE, digit span, logical memory, Controlled Oral Word Association, CERAD battery and neuropsychiatric inventory (NPI) in 77 patients (age at entry 69 +/- 8.1 years) with probable VaD-L for 25.75 +/- 11 months. RESULTS: The mean number of follow-up visits was 2.6 +/- 0.67 (range 2-4). Time interval between any two consecutive visits was at least 5 months (range 5-41). MMSE deteriorated by 1.44+/- 1.8 points annually and NPI increased by 6.01 +/- 13.7 points annually (p < 0.0001). The rates of cognitive and behavioral decline were predominantly influenced by the cognitive state at entry into the study and the occurrence of new vascular episodes during follow-up [(-0.95 +/- 1.7) MMSE and (+2.02 +/- 14.1) NPI points annually without vascular episodes vs. (-2.09 +/- 1.6) and (+11.3 +/- 11.4) points following vascular episodes (p < 0.0001)]. Impaired cognition was associated with impaired behavior (p < 0.001). VaD-L patients without additional vascular episodes at follow-up have a progressively deteriorating course as well (p < 0.0001). CONCLUSION: VaD-L is characterized by cognitive and behavioral decline. The rate of decline is determined mainly by the severity of the cognitive and behavioral impairment at baseline and by the occurrence of new vascular episodes. 相似文献