Long-term follow-up of microvascular decompression for trigeminal neuralgia

We conducted a study to evaluate the follow-up characteristics of patients with trigeminal neuralgia (TN) and to evaluate the factors affecting long-term outcome of microvascular decompression (MVD) in TN. Between 1983 and 2003, 156 patients with TN treated with MVD by 4 neurosurgeons at University Medical Centre Groningen/the Netherlands were evaluated. Baseline data from operative outcome were evaluated using univariate and multivariate analysis. The group consisted of 156 patients with TN: 90 females and 66 males with a median follow-up period of 9.7 years. The average age of initial symptoms was 51 years. The average duration of symptoms was 58 months. Postoperative 22 patients had a facial hyperpathia or hyperesthesia. Postoperatively, 137 patients had immediate relief. Postoperatively 1 year, 140 patients still had a good outcome of the operation. Twenty-seven patients with good immediate postoperative results had recurrent pain. From the group of patients with typical TN, 82% had good long-term results after operation. Patients with typical TN and immediate postoperative remission, in univariate analysis, had significantly more often an excellent/good postoperative outcome. Immediate postoperative remission is an independent predictive factor for a good long-term outcome. The long-term results of MVD in majority of patients were good with no mortalities and no major morbidities. Patients with typical TN had better long-term outcomes and less recurrence.     

Antenatal clinic-based HIV prevalence in Zambia: declining trends but sharp local contrasts in young women

OBJECTIVES: To describe regional variation in human immunodefffeciency virus (HIV) prevalence trends in the period 1994-2002 and to assess the effects on prevalence trends of residence, educational level and age, and potential interaction between these variables. METHODS: The data were from the national HIV sentinel surveillance system comprising information collected using interviews and unlinked anonymous testing of blood among pregnant women attending antenatal clinics in 22 sites in 1994, 1998 and 2002. RESULTS: There was a decline in HIV prevalence in the age group 15-24 years in the period 1994-2002 both in rural (by 11%) and urban (by 26%) areas. The decline was strongest among highly educated women. However, this overall decline masked striking differences at community (site) levels with clearly declining epidemics in many sites contrasted by increasing epidemics in some and stability in others. Urban/rural residence, age, educational attainment, marital status and parity were factors closely associated with HIV infection. Having born many children was associated with lower risk of being infected by HIV, even in the age group 15-24. CONCLUSIONS: The HIV prevalence decline in young women is likely to reflect a drop in incidence during the period. However, there were sharp geographical contrasts in trends. Such local contrasts probably indicate differences in effectiveness of preventive interventions. Understanding factors and mechanisms explaining the differences will be of critical importance to better guide preventive interventions.     

Trends in adolescent emotional problems in England: a comparison of two national cohorts twenty years apart

Background: Evidence about trends in adolescent emotional problems (depression and anxiety) is inconclusive, because few studies have used comparable measures and samples at different points in time. We compared rates of adolescent emotional problems in two nationally representative English samples of youth 20 years apart using identical symptom screens in each survey. Methods: Nationally representative community samples of 16–17‐year‐olds living in England in 1986 and 2006 were compared. In 1986, 4524 adolescents and 7120 parents of young people participated in the age‐16‐year follow‐up of the 1970 British Cohort Study. In 2006, 719 adolescents and 734 parents participated in a follow‐up of children sampled from the 2002/2003 Health Surveys for England. Adolescents completed the Malaise Inventory and 12‐item General Health Questionnaire. Parents completed the Rutter‐A scale. Individual symptoms of depression and anxiety were coded combining across relevant questionnaire items. Young people also reported frequency of feeling anxious or depressed. Results: Youth‐ and parent‐reported emotional problems were more prevalent in 2006 for girls, and rates of parent‐reported problems increased for boys. Twice as many young people reported frequent feelings of depression or anxiety in 2006 as in 1986. Some symptoms showed marked change in prevalence over time (e.g., worry, irritability, fatigue), whereas others showed no change (e.g., loss of enjoyment, worthlessness). There was no evidence of differential trends in emotional problems for young people from socially advantaged and disadvantaged or intact and non‐intact families. Changes in family structure and ethnic composition did not account for trends in youth emotional problems. Conclusions: The study provides evidence for a substantial increase in adolescent emotional problems in England over recent decades, especially among girls.     

Induction of neocortical long-term depression results in smaller movement representations, fewer excitatory perforated synapses, and more inhibitory synapses

Long-term depression (LTD) is one of the most widely investigated models of the synaptic mechanisms underlying learning and memory. Previous research has shown that induction of LTD in the neocortex decreases measures of pyramidal cell dendritic morphology in both layers III and V. Here, we investigated the effects of LTD induction on 1) the time course of recovery of synaptic efficacy, 2) movement representations, 3) cortical thickness and layer V neuron density, and 4) the density of excitatory and inhibitory synapses in layer V of sensorimotor neocortex. Rats carried a stimulating electrode in the midline corpus callosum and a recording electrode in the right sensorimotor neocortex. Each rat received either low-frequency stimulation composed of 900 pulses at 1 Hz or handling daily for a total of 20-25 days. Callosal-neocortical evoked potentials were recorded in the right hemisphere before and after stimulation or handling. Our results show that LTD induction lasts for 3 weeks and results in smaller motor maps of the caudal forelimb area. We did not observe any reduction in neocortical thickness or neuron density. There was a reduction in the density of excitatory perforated synapses and an increase in the density of inhibitory synapses in layer V of the sensorimotor neocortex, thereby providing a general mechanism for the reduction in motor map size. This study sheds light on the interaction between an artificial model of learning, receptive field characteristics, and synaptic number in the sensorimotor cortex.     

Evidence for adaptive radiation from a phylogenetic study of plant defenses

One signature of adaptive radiation is a high level of trait change early during the diversification process and a plateau toward the end of the radiation. Although the study of the tempo of evolution has historically been the domain of paleontologists, recently developed phylogenetic tools allow for the rigorous examination of trait evolution in a tremendous diversity of organisms. Enemy-driven adaptive radiation was a key prediction of Ehrlich and Raven''s coevolutionary hypothesis [Ehrlich PR, Raven PH (1964) Evolution 18:586–608], yet has remained largely untested. Here we examine patterns of trait evolution in 51 North American milkweed species (Asclepias), using maximum likelihood methods. We study 7 traits of the milkweeds, ranging from seed size and foliar physiological traits to defense traits (cardenolides, latex, and trichomes) previously shown to impact herbivores, including the monarch butterfly. We compare the fit of simple random-walk models of trait evolution to models that incorporate stabilizing selection (Ornstein-Ulenbeck process), as well as time-varying rates of trait evolution. Early bursts of trait evolution were implicated for 2 traits, while stabilizing selection was implicated for several others. We further modeled the relationship between trait change and species diversification while allowing rates of trait evolution to vary during the radiation. Species-rich lineages underwent a proportionately greater decline in latex and cardenolides relative to species-poor lineages, and the rate of trait change was most rapid early in the radiation. An interpretation of this result is that reduced investment in defensive traits accelerated diversification, and disproportionately so, early in the adaptive radiation of milkweeds.     

Hippocampus-dependent and -independent theta-networks of active maintenance

Recent studies in humans and animals raise the possibility that actively maintaining a detailed memory of a scene within working memory may require the hippocampus, a brain structure better known for its role in long-term memory. We show that the hippocampus is behaviorally and functionally critical for configural-relational (CR) maintenance by orchestrating the synchrony of occipital and temporal brain regions in the theta-frequency range. Using magnetoencephalography in healthy adults and patients with bilateral hippocampal sclerosis, we distinguish this hippocampus-dependent theta-network from one that is independent of the hippocampus and used for non-CR scene maintenance. This non-CR theta-network involved frontal and parietal brain regions. We also show that the functional and topographical dissociation between these two networks cannot be accounted for by perceptual difficulty or the amount of information to be maintained (“load”). Also, we confirm in healthy adults that active maintenance of the CR arrangement of objects within a scene is impaired by task-interference during the delay in a manner akin to working-memory maintenance processes. Together, these findings demand reconsideration of the classical functional-anatomical distinctions between long- and short-term memory.     

马来丝虫病不同巩固防治与净化措施的远期效果分析

目的 了解基本消除丝虫病后实施不同巩固防治与净化措施的远期效果.方法 采取查治残存传染源和全民普服0.3%乙胺嗪药盐的巩固与净化措施,开展丝虫病的重点人群和横向、纵向监测及慢性丝虫病调查.结果 夹江县于基本消除丝虫病后次年监测原微丝蚴血症者349人,检出复阳9例;筠连和夹江县于基本消除丝虫病后前3年,横向监测各检出残存微丝蚴血症者2人和15人,其中新检出1人和12人;洪雅县未检出微丝蚴血症者.3个县均元新发慢性丝虫病发生.结论 筠连和夹江县基本消除丝虫病后的初期,丝虫病传播继续存在,经采用巩固防治与净化措施和重点人群为主的监测措施后,未检出微丝蚴.通过消除丝虫病后监测,未发现内源性传染源,表明实施不同巩固和净化措施后的远期效果显著.     

烟台市2004～2007年艾滋病监测及流行趋势分析

目的分析烟台市2004～2007年艾滋病流行病学特点和流行趋势,为制定艾滋病预防和控制策略提供科学依据。方法对全市2004～2007年部分重点人群及艾滋病常规监测和哨点监测的实验室资料进行分析。结果2004～2007年共检出艾滋病毒（HIV）感染者82例,以青壮年为主,20～40岁占85.36%;男性多于女性,分别占70.73%和29.27%;初中和小学以下文化程度者占73.16%,已婚者占52.44%;外省籍占59.76%;农民和无业人员最多,占68.29%,工人占24.39%;主要传播途径为性接触,占60.97%,静脉吸毒占23.17%,采供血占13.41%。结论烟台市重点人群HIV感染率较高,传播途径多样化,性接触已成为主要传播途径。应继续开展艾滋病防治宣传教育,加强对高危人群的行为干预。     

Thirty-one years of clinical experience with "nuclear-powered" pacemakers

From 1973 through 1987, 164 radioisotope powered ("nuclear") pacemakers were implanted in 139 patients at the Newark Beth Israel Medical Center. Patient survival was much as might be expected from an age group as selected for this program. At 31 years (January 2005), 12 of the 139 patients (9%) were still alive. The experience reported here encompassed a span of 16 years of implantation with a follow-up of slightly more than 31 years. The problems encountered along the way were not remarkably different from those encountered in general clinical experience with pacemakers, except that the number of reoperations was fewer. In fact, most patients died with the initial implant in place. Deaths most commonly were due to cardiac causes (54%). The frequency of malignancies was similar to that of the age-matched population; primary tumor sites were randomly distributed. These results show that nuclear pacemakers were safe and reliable. Their longevity and the resulting decrease in reoperations offset their greater initial cost.