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Age-related memory decline is the consequence of multiple biological factors that lead to brain structural and functional change, including gray matter atrophy, white matter injury, and loss of functional coordination between regions. However, the independent roles that each of these brain changes play in mediating memory decline is not clear. Therefore, we used magnetic resonance imaging (MRI) to measure gray matter (GM) volume, white matter hyperintensity (WMH) volumes, and blood oxygen level-dependent (BOLD) functional magnetic resonance imaging-based functional connectivity among default mode network nodes in 76 cognitive normal older adults. We found that GM, WMH, and connectivity between left inferior parietal and medial prefrontal cortex (MPF_LIP) were independently associated with episodic memory performance. Within the group with GM volumes below the median, greater MPF_LIP connectivity was associated with better memory performance, whereas this association was not present for individuals with GM volume above the median. These findings confirm the heterogeneous nature of brain-behavior relationships in cognitive aging. In addition, the relationship between resting state functional connectivity and memory performance, particularly amongst those individuals with more brain atrophy, strongly suggests compensation against the effects of neuronal injury.  相似文献   
513.
Porcine reproductive and respiratory syndrome (PRRS) is a swine disease of major economic importance that causes reproductive and respiratory problems in pigs. PRRSV strains are divided into European (Type 1) and North-American (Type 2) genotypes. Within the European PRRSV genotype, three subtypes have been delineated. Full genome sequences for North American and European subtype 1 strains have been described. Here, the first complete genomic characterization of a European subtype 3 strain (Lena) is described. Amplification of Orf1a and Orf1b fragments was achieved using a set of degenerate oligonucleotides. Using RT-PCR with Lena-specific primers, the full length sequence (15001 nt) was obtained. Alignment of Lena with European subtype 1 reference strain Lelystad showed variation over the entire length (84% identity/89% similarity at amino acid level) with the most variation in Orf1a (Nsp2/NSP2) with a deletion of 29 amino acids. Phylogenetic relationships using different Orfs supported Lena’s genetic distinction from European subtype 1 strains. The availability of the European subtype 3 PRRSV full genome may be important for the understanding of PRRSV evolution and the more pronounced pathogenic nature of Lena.  相似文献   
514.
Macrophomina phaseolina (Tassi) Goid. is an important phytopathogenic fungus, infecting a large number of plant species and surviving for up to 15 years in the soil as a saprophyte. Although considerable research related to the biology and ecology of Macrophomina has been conducted, it continues to cause huge economic losses in many crops. Research is needed to improve the identification and characterization of genetic variability within their epidemiological and pathological niches. Better understanding of the variability within the pathogen population for traits that influence fitness and soil survival will certainly lead to improved management strategies for Macrophomina. In this context, the present review discusses various biological aspects and distribution of M. phaseolina throughout the world and their importance to different plant species. Accurate identification of the fungus has been aided with the use of nucleic acid-based molecular techniques. The development of PCR-based methods for identification and detection of M. phaseolina are highly sensitive and specific. Early diagnosis and accurate detection of pathogens is an essential step in plant disease management as well as quarantine. The progress in the development of various molecular tools used for the detection, identification and characterization of Macrophomina isolates were also discussed.  相似文献   
515.
Osteoporosis and fractures associated with it constitute a real and serious socio-medical problem, which only recently has come to the forefront of social consciousness. With increasing number of exservicemen and their dependents, osteoporosis management has become very important in our setup. Currently available pharmacological therapies for prevention of fragility fractures are limited in scope, efficacy and acceptability to patients. Oral bisphosphonates are the standard treatment for osteoporosis which are associated with significant gastrointestinal side effects and thus poor patient compliance. Newer regimens, including intravenous (IV) formulations of bisphosphonates, have successfully come in vogue with greater patient compliance and equal or better benefits. The real need in osteoporosis treatment is for additional anabolic drugs. The only currently approved anabolic agent for treating osteoporosis is teriparatide (recombinant human parathyroid hormone 1–34), which stimulates new bone formation. Considerable efforts are being made to develop new, more effective treatment for osteoporosis. These novel drugs under trial include those primarily inhibiting osteoclastic bone resorption (like bisphosphonates) such as inhibitors of receptor activator of nuclear factor-kappa B ligand (RANKL) signalling, cathepsin K inhibitors, c-Src kinase inhibitors, integrin inhibitors, chloride channel inhibitors and the drugs with osteo-anabolic actions such as orally active parathyroid hormone (PTH) analogues, calcium sensing receptor antagonists, PTH-related peptide analogues and agents that induce osteoblast anabolism via pathways involving key, recently identified, molecular targets (wnt low-density lipoprotein receptor-related protein-5 signalling; sclerostin antibodies).Key Words: Osteoporosis, Prevalent, Emerging therapies  相似文献   
516.
For patients who gain a troublesome amount of weight on antipsychotics, switching to a less obesogenic agent is an option. Aripiprazole appears to cause less weight gain than many other antipsychotics. We report on changes in weight, and other risk factors for heart disease, in thirty-three schizophrenia patients who agreed to switch from other antipsychotics to aripiprazole in an open, flexible-dose, eight-week trial. All patients were successfully switched. There were no significant changes in PANSS symptom scores or in CGI. Weight (Wt), waist circumference (WC), and low-density lipoprotein (LDL) decreased significantly in the group as a whole. In patients switched from olanzapine to aripiprazole, Wt, WC, LDL, fasting glucose, and triglycerides were significantly decreased as compared to baseline. Substantial decreases in several risk factors were also seen in patients switched from quetiapine, but these changes did not reach statistical significance.  相似文献   
517.

Background  

Optic nerve head drusen (ONHD) are white calcareous deposits, seen either superficially on the optic nerve head or buried within it. Diagnosis of ONHD is made by one or more ways: clinical exam, autofluorescence, ultrasound of the optic nerve, CT scan and/or visual field examination. The present study describes features of ONHD based on another diagnostic modality, the spectral-domain OCT (Spectralis).  相似文献   
518.
OBJECTIVES: This pilot study evaluated the efficacy and safety of adjunctive topiramate compared with placebo in the treatment of patients with a diagnosis of schizoaffective disorder, bipolar type (SAD-BT). METHODS: A sample of 48 adult patients with a Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision (DSM-IV-TR) diagnosis of SAD-BT (supported by the Structured Clinical Interview for DSM-IV Axis I Disorder, Patient Edition) were randomly assigned in a 2:1 ratio (favoring topiramate) to 8 weeks of double-blind treatment with topiramate (100-400 mg/day) or placebo. Patients who had achieved a > or =20% decrease from baseline in their Positive and Negative Syndrome Scale (PANSS) total scores were given the opportunity to continue for an additional 8 weeks of double-blind treatment. The dosage of the study medicine was continued unchanged from the earlier 8-week study period. At the end of the study period, the study medicine was tapered and discontinued over a 2-week period. Primary efficacy was assessed at 8 weeks using the mean change between treatment groups of the PANSS total scores in the intent-to-treat population of randomized patients. Several secondary measures were also assessed. Safety analyses included monitoring of adverse events, vital signs, electrocardiogram (ECG) and laboratory values. RESULTS: Even though both treatments reduced scores on various psychopathology rating scales, adjunctive topiramate treatment (nearly 275 mg/day) did not show increased efficacy relative to placebo on the primary outcome measure (PANSS scale) or any of the secondary outcome measures. Topiramate-treated patients lost significantly more body weight than placebo-treated patients, which led to a significant reduction in body mass index (BMI). Relative to adjunctive placebo, topiramate-treated patients experienced higher rates of paresthesia, sedation, word-finding difficulty, sleepiness, and forgetfulness, but these differences were not statistically significant. There were no clinically significant abnormalities in either the ECG or laboratory results. There were no serious adverse events in the study. Further, there was no worsening of the PANSS total scores (to > or =10% from baseline), and no significant differences between the treatments on worsening of total Montgomery-Asberg Depression Rating Scale (MADRS) scores [1/13 (7.7%) for placebo; 1/25 (4.0%) for topiramate]. CONCLUSIONS: This pilot study did not support clinical efficacy for adjunctive topiramate treatment in patients with SAD-BT. There were no major safety or tolerability issues in this study. Confirming the results of other studies, topiramate-treated patients did experience greater body weight loss and reduction in BMI.  相似文献   
519.
520.
The combination of noninvasive treatments in the periorbital area can be used to achieve dramatic and long-lasting results. New technologies and current therapies may supplement or even delay traditional surgical procedures.  相似文献   
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