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91.
Postembolic colonic infarction 总被引:12,自引:0,他引:12
92.
Penetrance of the fragile X-associated tremor/ataxia syndrome in a premutation carrier population 总被引:8,自引:0,他引:8
Jacquemont S Hagerman RJ Leehey MA Hall DA Levine RA Brunberg JA Zhang L Jardini T Gane LW Harris SW Herman K Grigsby J Greco CM Berry-Kravis E Tassone F Hagerman PJ 《JAMA》2004,291(4):460-469
Context Premutation expansions (55-200 CGG repeats) of the fragile X mental retardation 1 (FMR1) gene are frequent in the general population, with estimated prevalences of 1 per 259 females and 1 per 813 males. Several articles have recently described the presence of late-onset neurological symptoms in male carriers of premutation (FMR1) alleles. The main clinical features described in this newly identified syndrome are cerebellar ataxia and intention tremor. Additional documented symptoms include short-term memory loss, executive functional deficits, cognitive decline, parkinsonism, peripheral neuropathy, lower-limb proximal muscle weakness, and autonomic dysfunction. Objective To study the penetrance of the fragile Xassociated tremor/ataxia syndrome (FXTAS) among premutation carriers. Design, Setting, and Participants Family-based study of 192 individuals (premutation carriers and controls) whose families belong to the Northern or Southern California Fragile X Associations. Data were collected (March 2002-April 2003) through a survey and a standardized neurological examination, which was videotaped and subsequently scored in a blinded fashion. Main Outcome Measures Penetrance of intention tremor and ataxia among adult carriers (aged =" BORDER="0">50 years) of premutation expansions of the FMR1 gene. Results Data from the survey of 192 individuals demonstrated an age-related penetrance of the combination of reported intention tremor and gait ataxia in male carriers (17%, 38%, 47%, and 75% [lower-bound estimates] for participants aged 50-59, 60-69, 70-79, and =" BORDER="0">80 years, respectively). The male carrier group had an age-adjusted 13-fold increased risk (95% confidence interval, 3.9-25.4; P = .003) of combined intention tremor and gait ataxia when compared with male controls. The clinical examination data from 93 individuals demonstrated that male carriers experienced more difficulties on each of 3 standardized neurological rating scales compared with controls (P<.05). Female carrier scores were also higher than those of female controls (P<.05) on 2 of the 3 neurological rating scales, but no participant was identified with probable or definite FXTAS. Conclusions The study demonstrates that older male carriers of premutation alleles of the FMR1 gene are at high risk of developing FXTAS. Since male premutation carriers are relatively common in the general population, older men with ataxia and intention tremor should be screened for the FMR1 mutation, especially if these signs are accompanied by parkinsonism, autonomic dysfunction, or cognitive decline, regardless of family history. 相似文献
93.
In this study, we present a new method to derive a single-number measure of the directivity of hearing aids. The method is an extension of the conventional directivity index (DI), and is called overall directivity index (ODI). The directivities of five different hearing aid styles were compared with that of the open ear. The behind-the-ear (BTE) style showed the lowest directionality compared to the other hearing aid styles and the open ear. There were only minor differences in directivity between any of the four different hearing aid styles placed in the ear and of the open ear canal. The conventional measure of DI is less suitable for hearing aids, because it ignores sound coming from other than the frontal direction. To quantify directionality of a hearing aid in a real-life situation, we suggest the single-number ODI, weighted with the articulation index and related to a listening segment of 0-30 degrees. An application of the data is shown for a BTE with a directional microphone. 相似文献
94.
Loesch DZ Huggins RM Bui QM Epstein JL Taylor AK Hagerman RJ 《Journal of developmental and behavioral pediatrics : JDBP》2002,23(6):416-423
The effect of the fragile X mental retardation 1 (FMR1) gene product (fragile X mental retardation protein [FMRP]) deficits on Full-Scale IQ (FSIQ) and FSIQ-adjusted Wechsler subtests and index scores in fragile X disorder were assessed using a robust modification of the maximum likelihood estimators for pedigree data. The results from 144 extended families have demonstrated a linear effect of progressively reduced levels of FMRP on the FSIQ and all subtest and summary scores in either gender. The effect of FMRP in decreasing FSIQ-adjusted subtest scores was highly significant for Digit Span, Symbol Search, Object Assembly, and Picture Arrangement, with a consistent trend in both genders. Heritability for FSIQ and unadjusted subtest scores estimated from the covariance model did not exceed 50% and varied widely from the highest for Verbal score to the lowest for Picture Completion score. Possible mechanisms by which FMRP deficit impacts on specific weaknesses in fragile X are considered on the basis of present data. 相似文献
95.
Fragile X syndrome: a model of gene-brain-behavior relationships 总被引:5,自引:0,他引:5
96.
Hyper-reactivity and anxiety to sensory stimuli have been described in patients with fragile X syndrome (FXS), and may be related to abnormal processing in afferent sensory pathways. We used magnetoencephalography (MEG) to measure auditory responses to pure tones in 11 adults with FXS and 11 non-FXS subjects. The amplitude for the N100m auditory evoked field component was significantly higher for patients with FXS than for subjects. FXS subjects also had less lateralized N100m anterior-posterior dipole locations. These data may suggest that more neurons are activated by acoustic stimuli in FXS, consistent with subjective experience of increased stimulus intensity. Anomalous cerebral lateralization may suggest an early critical window for effects on neocortical development of the fragile X mental retardation protein (FMRP) produced by the FMR1 gene in individuals with FXS. 相似文献
97.
Gould EL Loesch DZ Martin MJ Hagerman RJ Armstrong SM Huggins RM 《American journal of medical genetics》2000,95(4):307-315
Sleep patterns and endogenous melatonin profiles in 13 fragile X boys between the age of 4.7 and 11.0 years were compared to those of 8 age-matched, normal control boys. Parents recorded sleep patterns on a Sleep Diary Chart for 14 consecutive days. Twelve saliva samples were obtained from 8 fragile X participants and all of the controls over 48 hours for the assessment of salivary melatonin profiles. The results showed greater variability in total sleep time and difficulty in sleep maintenance in fragile X boys compared with the control participants. Nocturnal melatonin production, expressed as both peak level and area under the concentration-time curve between 20:00 h and 08:00 h, were found to be significantly larger in fragile X boys than in controls. Additionally, the mean of the minimum daytime melatonin levels recorded was significantly higher for the fragile X group. Elevated levels in some fragile X boys relative to the range seen in controls, occurring either during the day or at night, or in both segments of the secretory profile for some individuals, may be due in part to overactivity of the sympathetic nervous system. Alternative molecular mechanisms leading to changes in melatonin profiles in fragile X are also discussed. 相似文献
98.
HO Garland † K Hamilton S Freeman C Burns M Cusack RJ Balment 《Clinical and experimental pharmacology & physiology》1999,26(10):803-808
1. Infusion experiments were performed on chronically catheterized conscious rats to assess kidney function before and after the induction of diabetes mellitus with streptozotocin. 2. Two infusion regimens were used, a conventional constant-infusion protocol and a novel computer-driven, servo-controlled fluid replacement technique. The latter enables body fluid status to be maintained throughout a study occasion by servo-controlled replacement of spontaneous urinary fluid losses. 3. The chronically catheterized conscious rat infused using a servo-controlled system appears to be the optimum model for a study of diabetic renal function. The conscious preparation circumvents problems associated with anaesthesia and acute surgery. The servo-controlled infusion protocol maintains the altered fluid status of the diabetic condition. Both hyperfiltration and polyuria, characteristics of human diabetes often absent in anaesthetized and/or constantly infused diabetic rats, were seen in all conscious servo-controlled diabetic animals. 4. The new regimen enables a more accurate assessment of renal function in experimental diabetes than with previous protocols. It should prove useful in future studies, particularly those assessing the role of anti-diabetic drugs on the kidney. 相似文献
99.
L Stankler D Lloyd RJ Pollitt ES Gray H Thom G Russell 《Archives of disease in childhood》1982,57(3):212-216
A family is described in which 2 siblings born to healthy parents presented with abnormal facies, persistent diarrhoea, and early death. Exhaustive pathological and biochemical investigations failed to find a cause. The scalp hair of both babies had an abnormal amino-acid composition, and presented an appearance that was unique on scanning electron microscopical examination; this fact and the clinical picture probably represents a new syndrome. 相似文献
100.