周期性内斜视

本文报告3例周期性内斜视,其变化周期均为48小时,即斜位相24小时,正位相24小时。病例1发病年龄为40岁,是国内所报道的发病年龄最大者,对该病例进行了脑电图检查,结果为“界限性脑电图”。此外,还于讨论中,对本病的临床表现及手术矫正方法等,进行了简要叙述。     

Temporal Coding of Amplitude and Frequency Modulation in the Rat Auditory Cortex

The rat primary auditory cortex was explored for neuronal responses to pure tones and sinusoidally amplitude-modulated (SAM) and frequency-modulated (SFM) stimuli. Units showed phase-locked responses to SAM stimulation (55%) and SFM stimulation (80%), with modulation frequencies up to 18 Hz. Tuning characteristics to the modulation frequency were mainly band-pass with best modulation frequencies (BMFs) between 4 and 15 Hz. Units with synchronized activity to SFM stimulation showed three response types with respect to the direction of the frequency modulation: 52% were selective to the upward direction, 30% to the downward direction, and 18% had no preference. Triangular frequency modulations were used to test if units were tuned to specific modulation frequencies or to specific rates of frequency change. In the vast majority of units tested the response characteristics were strongly influenced by varying the modulation frequency, whereas varying the rate of frequency change had little effect in the stimulus range used. Units that showed phase-locked responses to SAM and SFM stimulation had similar activity patterns in response to both types of stimuli. BMFs for SAM and SFM stimulation were significantly correlated. Intrinsic oscillations of up to 20 Hz could be seen in the spontaneous activity and after the stimuli independent of the stimulus type. Oscillation frequencies were significantly correlated with the BMFs of the respective units. The results are discussed in terms of a mechanism for periodicity detection based on a temporal code. This could be important for the recognition of complex acoustic signals.     

Broadening the Evidence Base for Evidence-Based Guidelines: A Research Agenda Based on the Work of the U.S. Preventive Services Task Force

Evidence-based evaluations of clinical preventive services help define priorities for research in prevention as part of primary health care. In this article, we draw on our experiences with the U.S. Preventive Services Task Force (USPSTF) to outline some major areas where research is needed to define the appropriate use of specific screening tests, counseling interventions, immunizations, and chemoprophylaxis. Areas of particular importance included research to: (1) Identify effective and practical primary care interventions for modifying personal health practices of patients, especially around issues such as diet, exercise, alcohol and drug use, and risky sexual behavior; (2) Clarify the optimal periodicity for certain screening tests and counseling interventions; (3) Identify practical ways to allow patients to share decision-making about preventive care, especially for services of possible but uncertain benefit; (4) Examine the most sensitive and efficient ways to identify high-risk groups who may need different services than the average population; and (5) Expand the use of decision-analysis and cost-effectiveness analysis to help identify optimal use of clinical preventive services. Given the difficulty of large, prospective trials, we discuss the use of alternative research designs to fill in critical gaps in the evidence for the effectiveness of specific services. Finally, we note several issues of increasing importance that may need to be addressed by future work of the USPSTF: what are the most reliable and effective ways to (1) measure and (2) improve the delivery and quality of preventive care provided in the primary care setting.     

Epidemiological chronorisk of stroke

A retrospective study was undertaken on onset of symptoms in 667 cases of stroke. All strokes occurred out of hospital. There were 382 males and 285 females, observed from 1971-1988. The 667 cases of stroke consisted of 508 cases of cerebral infarction and 159 cases of cerebral hemorrhage. The data, analyzed by the single cosinor method, demonstrate a significant circadian, circaseptan, and circannual rhythmicity in the occurrence of stroke. The peaks occur in the morning hours, in the weekend, and in winter. Cerebral hemorrhages do not have a circadian rhythmicity in their occurrence, while they do present circaseptan and circannual rhythmicity. Cerebral infarctions present circadian, circaseptan, and circannual rhythms. No difference was found between males and females. The possible factors involved in temporal distribution of stroke are discussed. These observations could be useful for a better understanding of the pathogenesis and treatment of stroke.     

Ibutilide Induced Intraatrial Wenckebach Periodicity in the Neonatal Canine Heart

PICKOFF, A.S., et al. : Ibutilide Induced Intraatrial Wenckebach Periodicity in the Neonatal Canine Heart. In nine anesthetized canine neonates, the high right atrium was paced at progressively shorter cycle lengths while recording high right atrial electrograms and left atrial appendage monophasic action potentials before and after the administration of the new Class III agent, ibutilide. Prior to ibutilide administration, 1:1 conduction was maintained from the high right atrium to the left atrial appendage at all paced cycle lengths, down to 160 ms. Following ibutilide, a pattern of intraatrial conduction was observed in two of nine neonates at a cycle length of 160 ms that was consistent with the development of intraatrial Wenckebach periodicity. This represents one of the only demonstrations of drug induced intraatrial Wenckebach periodicity in vivo and suggests that this rarely reported form of atrial conduction block might play a role in ibutilide's clinical efficacy against atrial arrhythmias.     

Age-period-cohort analysis of suicide rates in Rio de Janeiro, Brazil, 1979–1998

Abstract Background Recent studies in Brazil have demonstrated that suicide rates have been rising over the last years. The objective of this study was to investigate trends in suicide from 1979 to 1998 in Rio de Janeiro State, with emphasis on age, period, and cohort effects. Method Age-specific suicide rates from 1979 to 1998 were estimated for males and females based on mortality data obtained from the Brazilian Mortality Information System, and population counts from the 1980, 1991 and 2000 censuses. Poisson regression and graphical methods were used to evaluate age, period and cohort effects. Results Suicide rates increased steadily with age, particularly among males. In both males and females, age-adjusted suicide rates decreased until 1992. In 1993, rates started to rise. Cohort effects showed that younger generations had significantly lower rates of suicide than older ones. Conclusion The recent rise in suicide rates might be a result of the increasing levels of firearm availability, drug use, and unemployment. Follow-up over longer periods and powerful epidemiological studies are needed to sustain the implication of socio-economic changes in the observed features.     

Persistent elevation of urinary free cortisol and loss of circannual periodicity in recovered depressive patients. A trait finding

By comparing a group of 8 normal subjects with 7 recovered depressive patients who had been dexamethasone suppression test (DST) nonsuppressors while depressed, the following differences were identified: (1) mean urinary free cortisol (UFC) levels were significantly higher for recovered depressive patients than for controls in the summer and fall as well as for the year; (2) patients who had recovered from depression lost their circannual pattern of cortisol excretion; and (3) there was a positive correlation between depressive symptoms as reflected on the Beck Depression Inventory and UFC levels in recovered patients but not controls. The elevated UFC levels in depressed patients with DST nonsuppression represents the first trait marker which persists over time. The implications of the close association between UFC levels and depressive symptoms is discussed.     

Molecular and epidemiological features of GIIb norovirus outbreaks in Victoria,Australia, 2002–2005

The epidemiology of GIIb norovirus outbreaks and the characteristics of GIIb open reading frame (ORF) 2 recombinant forms are poorly understood and this study examined these questions using norovirus‐associated gastroenteritis outbreaks in Victoria, Australia, during 2002–2005. Twenty‐one GIIb outbreaks were detected and were the second most common ORF 1 norovirus outbreak genotype (5%) after GII.4 (90%). Both GIIb and GII.4 outbreaks peaked in warmer months of the year but their periodicity was different. ORF 2 sequencing analysis was carried out in the two regions previously designated C and D. RT‐PCR region D primers were less sensitive than region C primers. No evidence of recombination between regions C and D was found. ORF 2 genotypes for the 21 GIIb outbreaks were: GII.1 (10 outbreaks), GII.3 (10 outbreaks) and, apparently for the first time, GII.13 (1 outbreak). GIIb outbreaks could occur in a broad range of settings and there was no correlation between ORF 2 genotype and setting except that all 5 outbreaks involving mainly young children were associated with GIIb/GII.3. J. Med. Virol. 81:1652–1660, 2009. © 2009 Wiley‐Liss, Inc.