Necesidades de tratamientos odontológicos de los ancianos del Asilo de la ciudad de León, segundo semestre 2004

Tesis (Dr. Cirujano Dentista)-Universidad Nacional Autónoma de Nicaragua, LeónUNAN-Leó

EEG Frequency Correlates with α₂-Receptor Density in Parkinson’s Disease

Introduction: Increased theta and delta power and decreased alpha and beta power, measured with quantitative electroencephalography (EEG), have been demonstrated to have utility for predicting the development of dementia in patients with Parkinson’s disease (PD). Noradrenaline modulates cortical activity and optimizes cognitive processes. We claim that the loss of noradrenaline may explain cognitive impairment and the pathological slowing of EEG waves. Here, we test the relationship between the number of noradrenergic α2 adrenoceptors and changes in the spectral EEG ratio in patients with PD. Methods: We included nineteen patients with PD and thirteen healthy control (HC) subjects in the study. We used positron emission tomography (PET) with [11C]yohimbine to quantify α2 adrenoceptor density. We used EEG power in the delta (δ, 1.5–3.9 Hz), theta (θ, 4–7.9 Hz), alpha (α, 8–12.9 Hz) and beta (β, 13–30 Hz) bands in regression analyses to test the relationships between α2 adrenoceptor density and EEG band power. Results: PD patients had higher power in the theta and delta bands compared to the HC volunteers. Patients’ theta band power was inversely correlated with α2 adrenoceptor density in the frontal cortex. In the HC subjects, age was correlated with, and occipital background rhythm frequency (BRF) was inversely correlated with, α2 adrenoceptor density in the frontal cortex, while occipital BRF was inversely correlated with α2 adrenoceptor density in the thalamus. Conclusions: The findings support the claim that the loss or dysfunction of noradrenergic neurotransmission may relate to the parallel processes of cognitive decline and EEG slowing

A robust method for the detection of small changes in relaxation parameters and free water content in the vicinity of the substantia nigra in Parkinson’s disease patients

Alterations in the substantia nigra are strongly associated with Parkinson’s disease. However, due to low contrast and partial volume effects present in typical MRI images, the substantia nigra is not of sufficient size to obtain a reliable segmentation for region-of-interest based analysis. To combat this problem, the approach proposed here offers a method to investigate and reveal changes in quantitative MRI parameters in the vicinity of substantia nigra without any a priori delineation. This approach uses an alternative method of statistical, voxel-based analysis of quantitative maps and was tested on 18 patients and 15 healthy controls using a well-established, quantitative free water mapping protocol. It was possible to reveal the topology and the location of pathological changes in the substantia nigra and its vicinity. Moreover, a decrease in free water content, T1 and T2* in the vicinity of substantia nigra was indicated in the Parkinson’s disease patients compared to the healthy controls. These findings reflect a disruption of grey matter and iron accumulation, which is known to lead to neurodegeneration. Consequently, the proposed method demonstrates an increased sensitivity for the detection of pathological changes—even in small regions—and can facilitate disease monitoring via quantitative MR parameters

Satisfaction of Family Physicians (FPs) about the Effective Factors on Activation of FP Program and Rural Insurance in the Northern Provinces of Iran

BACKGROUND AND OBJECTIVE: Successful implementation of FP program and rural insurance requires continuous collaboration among the intersectoral and intrasectoral organizations. FPs’ satisfaction from related institutions can lead to more motivation, longer activity and better services in the organization. This study was performed to evaluate the level of FPs’ satisfaction in Northern provinces of Iran. METHODS: This cross-sectional study was performed in winter 2013. Totally 139 health centers from 552 which implement the family physician program and rural insurance coverage in Mazandaran, Golestan and Guilan provinces were randomly selected. In each center all of available FPs included. A researcher-made questionnaire was used for data gathering. In this questionnaire, personal characteristics with 10 open and closed questions, satisfaction from human and physical resources available at the first level, the function of health center of the city, the function of specialists at the second level, the performance of underlying population of intersectional organizations were asked through 34 questions with Likert scales. Validity and reliability of the questionnaire were approved. FINDINGS: Mean of the level of 188 FPs’ satisfaction about health team, equipment and facilities in the centers (of 5 score) was 3±0.6, underlying population was 2.8±0.8, intersectoral collaboration was 2.8±1, the function of district health center was 2.7±0.9, the function of specialists was 2.1±0.9. The level of FPs’ satisfaction from the specialists of the functional second level showed a significant difference in the Northern provinces of Iran (p=0.001). There was not a significant relationship between age, underlying population, recorded services, the number of replacements and the level of FPs satisfaction. CONCLUSION: The results of this study showed that the level of FPs’ satisfaction was moderate therefore, interventional program at different levels should be planned and implemented to protect and promote it

Quantification of [¹¹C]yohimbine binding to α₂ adrenoceptors in rat brain <i>in vivo</i>

We quantified the binding potentials (BP(ND)) of [(11)C]yohimbine binding in rat brain to alpha-2 adrenoceptors to evaluate [(11)C]yohimbine as an in vivo marker of noradrenergic neurotransmission and to examine its sensitivity to the level of noradrenaline. Dual [(11)C]yohimbine dynamic positron emission tomography (PET) recordings were applied to five Sprague Dawley rats at baseline, followed by acute amphetamine administration (2 mg/kg) to induce elevation of the endogenous level of noradrenaline. The volume of distribution (V(T)) of [(11)C]yohimbine was obtained using Logan plot with arterial plasma input. Because alpha-2 adrenoceptors are distributed throughout the brain, the estimation of the BP(ND) is complicated by the absence of an anatomic region of no displaceable binding. We used the Inhibition plot to acquire the reference volume, V(ND), from which we calculated the BP(ND). Acute pharmacological challenge with amphetamine induced a significant decline of [(11)C]yohimbine BP(ND) of ~38% in all volumes of interest. The BP(ND) was greatest in the thalamus and striatum, followed in descending order by, frontal cortex, pons, and cerebellum. The experimental data demonstrate that [(11)C]yohimbine binding is sensitive to a challenge known to increase the extracellular level of noradrenaline, which can benefit future PET investigations of pathologic conditions related to disrupted noradrenergic neurotransmission