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101.
Resting tremor is the most specific sign for idiopathic Parkinson' disease. It has been proposed that parkinsonian tremor results from the activity of the central oscillators. One of the hypotheses, which have been proposed about the possible principles underlying such central oscillations, is the subthalamic nucleus (STN)-external globus pallidus (GPe)-pacemaker hypothesis. Activity from the central oscillator is proposed to be transmitted via trans-cortical pathways to the periphery. A computational model of the basal ganglia (BG) is proposed for simulating the effects of the internal globus pallidus (GPi)-pedunculopontine (PPN) loop activity on the transmission of the STN-GPe-pacemaker oscillatory activities to the cortex, based on known anatomy and physiology of the BG. According to the result of the simulation, the GPi-PPN loop activity can suppress the transmission of the STN-GPe-pacemaker oscillatory activities to the cortex. This suppressive effect is controlled by various factors such as the strength of the synaptic connection from the PPN to the GPi, the strength of the synaptic connection from the GPi to the PPN, the spontaneous tonic activities of the GPi and PPN, the direct excitatory projections from the STN to the PPN, the frequency of the STN oscillatory burst activity, the duration of the STN burst, and the maximum T-type calcium channel conductance in the type-I PPN neurons.  相似文献   
102.
Precise regulation of dopaminergic activity is of obvious importance for the physiology and pathology of basal ganglia. We report here that nanomolar concentrations of the astrocyte-derived neuroinhibitory metabolite kynurenic acid (KYNA) potently reduce the extracellular levels of striatal dopamine in unanesthetized rats in vivo. This effect, which is initiated by the KYNA-induced blockade of alpha7 nicotinic acetylcholine receptors, highlights the functional relevance of glia-neuron interactions in the striatum and indicates that even modest increases in the brain levels of endogenous KYNA are capable of interfering with dopaminergic neurotransmission.  相似文献   
103.
We present a novel automated strategy (PISTACHIO) for the probabilistic assignment of backbone and sidechain chemical shifts in proteins. The algorithm uses peak lists derived from various NMR experiments as input and provides as output ranked lists of assignments for all signals recognized in the input data as constituting spin systems. PISTACHIO was evaluate00000000d by comparing its performance with raw peak-picked data from 15 proteins ranging from 54 to 300 residues; the results were compared with those achieved by experts analyzing the same datasets by hand. As scored against the best available independent assignments for these proteins, the first-ranked PISTACHIO assignments were 80–100% correct for backbone signals and 75–95% correct for sidechain signals. The independent assignments benefited, in a number of cases, from structural data (e.g. from NOESY spectra) that were unavailable to PISTACHIO. Any number of datasets in any combination can serve as input. Thus PISTACHIO can be used as datasets are collected to ascertain the current extent of secure assignments, to identify residues with low assignment probability, and to suggest the types of additional data needed to remove ambiguities. The current implementation of PISTACHIO, which is available from a server on the Internet, supports input data from 15 standard double- and triple-resonance experiments. The software can readily accommodate additional types of experiments, including data from selectively labeled samples. The assignment probabilities can be carried forward and refined in subsequent steps leading to a structure. The performance of PISTACHIO showed no direct dependence on protein size, but correlated instead with data quality (completeness and signal-to-noise). PISTACHIO represents one component of a comprehensive probabilistic approach we are developing for the collection and analysis of protein NMR data.Electronic Supplementary Material Electronic Supplementary material is available for this article at and accessible for authorised users.  相似文献   
104.
The Bacillus subtilis bex gene complemented the defect in an Escherichia coli era mutant. The Bex protein showed 39 percent identity and 67 percent similarity to the E. coli Era GTPase. In contrast to era, bex was not essential in all strains. bex mutant cells were elongated and filled with diffuse nucleoid material. They grew slowly and exhibited severely impaired spore formation.  相似文献   
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107.
Immunotherapy has caused a paradigm shift in the treatment of several malignancies, particularly the blockade of programmed death-1 (PD-1) and its specific receptor/ligand PD-L1 that have revolutionized the treatment of a variety of malignancies, but significant durable responses only occur in a small percentage of patients, and other patients failed to respond to the treatment. Even those who initially respond can ultimately relapse despite maintenance treatment, there is considerable potential for synergistic combinations of immunotherapy and chemotherapy agents with immune checkpoint inhibitors into conventional cancer treatments. The clinical experience in the use of cytokines in the clinical setting indicated the efficiency of cytokine therapy in cancer immunotherapy. Combinational approaches to enhancing PD-L1/PD-1 pathways blockade efficacy with several cytokines such as interleukin (IL)-2, IL-15, IL-21, IL-12, IL-10, and interferon-α (IFN-α) may result in additional benefits. In this review, the current state of knowledge about PD-1/PD-L1 inhibitors, the date in the literature to ascertain the combination of anti-PD-1/PD-L1 antibodies with cytokines is discussed. Finally, it is noteworthy that novel therapeutic approaches based on the efficient combination of recombinant cytokines with the PD-L1/PD-1 blockade therapy can enhance antitumor immune responses against various malignancies.  相似文献   
108.

Objectives

Health-related quality of life (HRQoL) is considered a very important outcome indicator in patients with Parkinson’s disease (PD). A broad list of motor and non-motor features have been shown to affect HRQoL in PD, however, there is a dearth of information about the complexity of interrelationships between determinants of HRQoL in different PD phenotypes. We aimed to find independent determinates and the best structural model for HRQoL, also to investigate the heterogeneity in HRQoL between PD patients with different phenotypes regarding onset-age, progression rate and dominant symptom.

Methods

A broad spectrum of demographic, motor and non-motor characteristics were collected in 157 idiopathic PD patients, namely comorbidity profile, nutritional status, UPDRS (total items), psychiatric symptoms (depression, anxiety), fatigue and psychosocial functioning through physical examination, validated questionnaires and scales. Structural equation model (SEM) and multivariate regressions were applied to find determinants of Parkinson’s disease summary index (PDSI) and different domains of HRQoL (PDQ-39).

Results

Female sex, anxiety, depression and UPDRS-part II scores were the significant independent determinants of PDSI. A structural model consisting of global motor, global non-motor and co-morbidity indicator as three main components was able to predict 89% of the variance in HRQoL. In older-onset and slow-progression phenotypes, the motor domain showed smaller contribution on HRQoL and the majority of its effects were mediated through non-motor features. Comorbidity component was a significant determinant of HRQoL only among older-onset and non-tremor-dominant PD patients. Fatigue was not a significant indicator of non-motor component to affect HRQoL in rapid-progression PD.

Conclusions

Our findings showed outstanding heterogeneities in the pattern and determinants of HRQoL among PD phenotypes. These factors should be considered during the assessments and developing personalized interventions to improve HRQOL in PD patients with different phenotypes or prominent feature.  相似文献   
109.
Human-carnivore conflicts challenge biodiversity conservation and local livelihoods, but the role of diseases of domestic animals in their predation by carnivores is poorly understood. We conducted a human-leopard (Panthera pardus) conflict study throughout all 34 villages around Golestan National Park, Iran in order to find the most important conflict determinants and to use them in predicting the probabilities of conflict and killing of cattle, sheep and goats, and dogs. We found that the more villagers were dissatisfied with veterinary services, the more likely they were to lose livestock and dogs to leopard predation. Dissatisfaction occurred when vaccination crews failed to visit villages at all or, in most cases, arrived too late to prevent diseases from spreading. We suggest that increased morbidity of livestock makes them particularly vulnerable to leopard attacks. Moreover, conflicts and dog killing were higher in villages located closer to the boundaries of the protected area than in distant villages. Therefore, we appeal for improved enforcement and coordination of veterinary services in our study area, and propose several priority research topics such as veterinarian studies, role of wild prey in diseases of domestic animals, and further analysis of potential conflict predictors.  相似文献   
110.
Insects have evolved amazing methods of defense to ward off enemies. Many aphids release cornicle secretions when attacked by predators and parasitoids. These se cretions contain an alarm pheromone that alerts other colony members of danger, thereby providing indirect fitness benefits to the releaser. In addition, contact with cornicle se cretions could also threaten an attacker and could provide direct fitness to the releaser. However, cornicle secretions may also be recruited as a kairomonal cue by aphid natural enemies. In this study, we investigated the effect of the cornicle droplet volatiles of the cabbage aphid, Brevicoryne brassicae (L.), on the hostsearching behavior of naive and experienced female Diaeretiella rapae (M'Intosh) parasitoids in olfactometer studies. In addition, we evaluated the role ofB. brassicae cornicle droplets on the oviposition prefer ence of the parasitoid in a twochoice bioassay. Naive females did not exhibit any preference between volatiles from aphids secreting cornicle droplets over nonsecreting aphids, while experienced parasitoids exploited the secretions in their host location. Experienced females were also able to choose volatiles from both secreting and nonsecreting aphids over clean air, while this ability was not observed in naive females. Although secretion of cornicle droplets did not influence the percentage of first attack in either naive or experienced females, the success of attack (i.e. resulting in a larva) was significantly different between secreting and nonsecreting aphids in the case of experienced parasitoids.  相似文献   
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