Mapping brain size and cortical gray matter changes in elderly depression.

BACKGROUND: In elderly depression, volumetric brain imaging findings suggest abnormalities of the frontal lobe, particularly the orbitofrontal cortex, and the hippocampus. No studies to date have mapped cortical abnormalities over the entire brain surface in major depression. Here, we conducted detailed spatial analyses of brain size and gray matter within the cortical mantle in elderly patients with major depression. METHODS: High-resolution, three-dimensional, structural magnetic resonance imaging data and cortical pattern matching methods were used in 24 depressed elderly patients and 19 group-matched controls to measure local brain size and proportions of gray matter at thousands of homologous cortical surface locations. RESULTS: Prominent brain size reductions were observed in the depressed subjects in the orbitofrontal cortex bilaterally. Cortical gray matter measurements revealed significant gray matter increases in the orbitofrontal cortex, adjacent to focal trend level significant decreases of gray matter in the same region. Depressed patients also exhibited significant gray matter increases in parietal cortices, as well as the left temporal cortex. CONCLUSIONS: Complex cortical changes may contribute to the brain size reduction of the orbitofrontal cortex and to the gray matter abnormalities detected in orbitofrontal cortex and temporoparietal cortices, thereby providing a potentially new window into the pathophysiology of elderly depression.     

Palatal implants: a new approach for the treatment of obstructive sleep apnea.

OBJECTIVE: To evaluate the short-term safety and efficacy of palatal implants in patients with mild and moderate obstructive sleep apnea (OSA). STUDY DESIGN AND SETTING: A prospective, non-randomized study conducted at 5 clinical sites. Three polyester implants were placed in the soft palate under local anesthesia during a single-stage office procedure. Polysomnography was conducted at baseline and 90 days post-procedure. Subjective quality of life data were collected. RESULTS: Fifty-three patients were evaluated; the apnea hypopnea index (AHI) decreased from 25.0 +/- 13.9 to 22.0 +/- 14.8 events/hour (P = 0.05). The Epworth Sleepiness Scale (ESS) decreased from 11.0 +/- 5.1 to 6.9 +/- 4.5 (P < 0.001), and the snore score decreased from 7.9 +/- 2.1 to 4.0 +/- 3.0 (P < 0.001). No serious complications occurred during the study. CONCLUSION: Palatal implants can be an effective initial low morbidity treatment option for patients diagnosed with mild to moderate OSA.     

喷雾(冰冻)干燥法制备钠、锂快离子导体

对两种性能较好的快离子导体Na_3Zr_2Si_2P_3O_(12)(Nasicon)和Li_(1.8)Ti_(1.2)·Cr_(0.8)P_3O_(12)用喷雾干燥法和冰冻干燥法制备粉料和陶瓷烧结,并对样品进行了X射线衍射分析,形貌和显微结构观察以及阻抗谱测量等。实验结果表明:两种方法制备的粉料具有颗粒细,均匀性好,合成温度低等优点。在300℃时,两种样品的电阻半分别为10.05 Ω.cm和94.8 Ω.cm。激活能分别为0.25 eV和0.27ev。     

Development of integrated provision for pre-fives in the UK

This paper analyses the diverse services currently available for children under five in the UK, and considers the nature of the demand for them. It recounts the initiative made by Strathclyde Region to co-ordinate and integrate pre-five provision, administratively and at a service level. It then considers the efforts of other local authorities to integrate administratively and looks at some of the complexities of attempting to do so at a service level.     

Melatonin Levels in the Gastrointestinal Tissues of Fish, Amphibians, and a Reptile

Melatonin was detected by radioimmunoassay in the gastrointestinal tract (GIT) of several species of fish (sturgeon, rainbow trout, carp), amphibians (axolotl, leopard frog, bullfrog), and one reptile (red-sided garter snake), which were sacrificed during the daytime. The highest levels of melatonin were detected in the snake [means = 1018 pg/g stomach, 328 pg/g proximal gut (PG), 511 distal gut (DG)] and carp (means = 102 pg/g stomach, 146 pg/g PG and 141 pg/g DG). Lowest levels were found in the axolotl (means = 44 pg/g stomach and PG, 92 pg/g DG) and the bullfrog (means = 73 pg/g esophagus, 78 pg/g stomach, 20 pg/g PG, and 152 pg/g DG). In most cases there were no statistically significant differences in the melatonin levels among various GIT tissues of the same species but there were differences in tissue levels between different species.     

Going, going, gone . . . ? Implicit and explicit tests of conceptual knowledge in a longitudinal study of semantic dementia

Patients suffering from semantic dementia provide important constraints on theories of the structure and organisation of semantic memory. In this article we report one such patient, AM, whose progressive deterioration of semantics enables us to address the much-debated issue of whether conceptual structure is hierarchically organised. The hierarchical account predicts that brain damage should impair lower levels of the hierarchy (property information) before affecting higher level (category) information (Warrington and Shallice, Q. J. Exp. Psychol. 1975, 27, 635–657). We evaluate this prediction by repeated testing of AM in two studies—a semantic priming task and a verification task—over an 18 month period, contrasting the progressive deterioration of properties (functional and perceptual) and category relations (category co-ordinates and category labels). Properties were preserved longer than category information, arguing against a hierarchical account of semantic memory. In addition, functional properties were most robust to brain damage, supporting our claim that functional information plays a special role in semantic representations (Durrant-Peatfield et al., Proc. 19th Ann. Conf. of the Cognitive Science Society. Erlbaum, Mahwah, NJ, 1997, pp. 193–198. Tyler et al., Cognitive Neuropsychol. 1997, 14, 511–545).     

The Results of Water Fluoridation in Ireland

The visit of Dr. Trendley Dean to Dublin in the mid-1950s helped accelerate the decision to introduce water fluoridation as a public health measure in the prevention of caries in the Republic of Ireland. A challenge to the constitutional validity of the Health (Fluoridation of Water Supplies) Act 1960 failed and in 1964 the water supplies of Dublin city were fluoridated. Over the next seven to eight years all the major urban communities in the Republic of Ireland were fluoridated. Currently, 67 percent of the 3.5 million people in the country reside in fluoridated communities. Studies conducted over the last 20 years show that residents of fluoridated communities have better dental health than those in nonfluoridated communities—the mean dmft is lower in children and the number of natural teeth present in adults is higher.