Cocaine decreases self-control in rats: a preliminary report

Cocaine abuse is often associated with behavior that takes into account short-term, but not long-term consequences. However, there has been no empirical research concerning the effects of cocaine on self-control (choice of a larger, more delayed reinforcer over a smaller, less delayed reinforcer). In the present research, when food-deprived rats repeatedly chose between a larger, more delayed food reinforcer and a smaller, less delayed food reinforcer, chronic intraperitoneal injections of 15 mg/kg cocaine (but not 10 mg/kg fluoxetine) decreased the rats' choices of the larger, more delayed reinforcer. Cocaine can decrease rats' self-control.     

312例活动性肺结核延误诊断的临床分析

本文报告1986年12月至1988年5月在我科门诊确诊的312例新发现活动性肺结核延误诊断情况。结果表明,新发现活动性肺结核的及时诊断率为67.1％,总延误率为32.9％,平均延误时间为75天。提示我区肺结核的延误诊断情况较严重。如能采取多方面综合性措施,结核病的发现问題可望有所好转。     

Skin Conductance Conditioning to Potentially Phobic Stimuli as a Function of Interstimulus Interval and Delay Versus Trace Paradigm

Because prepared learning has been defined in terms of response acquisition in spite of degraded input, it was expected that differences in resistance to extinction between skin conductance responses conditioned to potentially phobic and neutral stimuli would increase with increased interstimulus interval (ISI) and be larger with a trace than with a delay conditioning paradigm. Twelve groups with 10 subjects each were observed in a differential conditioning experiment manipulating ISI (2, 8, or 16 sec), paradigm (delay versus trace), and fear-relevance of the conditioned stimulus (potentially phobic versus neutral). The results showed highly reliable resistance to extinction of first-interval anticipatory responses to phobic stimuli, and no resistance to extinction of the corresponding responses to the neutral stimuli. This difference did not interact either with the ISI or the paradigm factor. Thus, although underscoring the reliability of the difference in conditioning to potentially phobic and neutral stimuli, the results did not support the specific hypothesis of conditioning to phobic stimuli as being less dependent on the ISI parameters than conditioning to neutral stimuli.     

The effect of transcranial magnetic stimulation on the latencies of vertical saccades

In this study, we investigated the effect of transcranial magnetic stimulation (TMS) over the right posterior parietal cortex (PPC) on the latency of two different types of visually-guided vertical saccades: reflexive saccades triggered by the sudden onset of a target, and saccades towards target locations known in advance. For this reason, we used two oculomotor tasks: a gap and a delay task, respectively. Nine normal subjects performed vertical saccades at ±7.5 and ±15°. TMS was applied at 80 and 100 ms after target onset in the gap task, and after fixation offset in the delay task. Without TMS, we confirmed a latency asymmetry in the gap task favouring upward saccades at the lower eccentricity (7.5°), and a latency symmetry in the delay task. TMS increased the latencies of all saccades in the delay task, when delivered at 100 ms. This effect was mostly pronounced for downward saccades at 7.5°. As a result, saccade latencies showed an asymmetry in this condition, similar to the one observed in the gap task without TMS. The gap task with TMS resulted in a variable latency distribution and no significant overall effect on saccade latency. Our results indicate that the right PPC is involved in the initiation of vertical saccades in the delay task, and that this involvement appears to be enhanced for downward saccades. A conclusion for the involvement of this area in the gap task could not be drawn from this study.     

Impulsivity and cigarette smoking: delay discounting in current, never, and ex-smokers

Rationale: Impulsivity is implicated in drug dependence. Recent studies show problems with alcohol and opioid dependence are associated with rapid discounting of the value of delayed outcomes. Furthermore, discounting may be particularly steep for the drug of dependence. Objectives: We determined if these findings could be extended to the behavior of cigarette smokers. In particular, we compared the discounting of hypothetical monetary outcomes by current, never, and ex-smokers of cigarettes. We also examined discounting of delayed hypothetical cigarettes by current smokers. Methods: Current cigarette smokers (n=23), never-smokers (n=22) and ex-smokers (n=21) indicated preference for immediate versus delayed money in a titration procedure that determined indifference points at various delays. The titration procedure was repeated with cigarettes for smokers. The degree to which the delayed outcomes were discounted was estimated with two non-linear decay models: an exponential model and a hyperbolic model. Results: Current smokers discounted the value of delayed money more than did the comparison groups. Never- and ex-smokers did not differ in their discounting of money. For current smokers, delayed cigarettes lost subjective value more rapidly than delayed money. The hyperbolic equation provided better fits to the data than did the exponential equation for 74 out of 89 comparisons. Conclusions: Cigarette smoking, like other forms of drug dependence, is characterized by rapid loss of subjective value for delayed outcomes, particularly for the drug of dependence. Never- and ex-smokers could discount similarly because cigarette smoking is associated with a reversible increase in discounting or due to selection bias. Received: 3 March 1999 / Final version: 11 May 1999     

增城地区脑梗死患者就诊延迟的影响因素分析

目的探索造成脑梗死急性期就诊延迟的相关因素,从而寻找可能的解决办法。方法采用问卷调查的方法,随机选取2008年9月至2010年6月来院就诊的280例急性脑梗死患者,采用t检验、2检验和Logistic回归模型分析就诊延迟的相关因素。结果全部脑梗死患者均经头颅CT/MRI证实,与就诊延迟最重要的相关因素是患者对脑梗死的认识,其次分别为抵院方式、发病地点距医院距离。结论导致急性脑梗死患者就诊延迟的相关因素很多,其中最重要原因是患者对脑梗死早期诊治认识不足,加强公众相关医学知识教育对减少这些因素的影响将具有重要意义。     

Underutilization of the MSLT in sleepy patients with a short onset REM period (SOREMP) in the sleep clinic

Objective/BackgroundA nocturnal sleep onset REM period (defined as REM onset latency ≤ 15 min; SOREMP) occurs rarely and research has shown that the phenomenon is specific for type 1 and 2 narcolepsy. However, little is known about the meaningfulness of the phenotype in general sleep clinic patients because those that exhibit the phenomenon often present with few traditional narcolepsy symptoms. As such, this study aimed to (1) evaluate the rate of eventual MSLT testing for those with a SOREMP on routine PSG when the phenomenon occurred in the absence of potential explanatory factors and (2) quantify the stability of the SOREMP phenotype.Patients/MethodsThis was a retrospective analysis of a large repository of de-identified PSG and MSLT test results from 2008 to 2015. Patient records were retrieved from a repository of studies completed at a variety of sleep laboratories across the USA. A total of 118,046 baseline polysomnograms were evaluated for a PSG SOREMP (occurred in 0.7% of the sample). Patients were excluded if they indicated working either shift or night work at the time of the SOREMP or if their self-reported habitual weekday time in bed was less than 7 h. A final sample of 391 cases with a SOREMP were sequestered and previous or consecutive studies were searched for each individual.ResultsThe vast majority of patients (n = 347/391; 89%) with a PSG SOREMP never received MSLT testing. Patients that were evaluated by MSLT (n = 44; 11%) were typically very sleepy and 82% ended up with a diagnosis of narcolepsy or had MSLTs consistent with current narcolepsy criteria (ie, including the nocturnal SOREMP). Only seven of the 140 patients (n = 5%) that with OSA that first underwent one or more PAP titrations were subsequently seen for an MSLT. Compared to those that eventually received an MSLT, patients that did not receive MSLT testing were older (52 vs. 41 years, p < 0.001), more likely to have moderate to severe OSA (AHI ≥ 15; 39% vs. 16%, p < 0.001), and were generally less likely to report severe sleepiness (ESS ≥ 16; 25% vs. 55%, p < 0.001) and vehicle or workplace accidents or injuries. However, 12% of those that never received an MSLT reported such extreme sleepiness that they endorsed a near-miss car accident due to sleepiness, almost twice as prevalent than that found in a random sample of matched moderate-to-severe OSA patients (p < 0.01). Overall, the reliability of the SOREMP phenotype was low at 9.8%, but was much higher for those diagnosed with type 2 narcolepsy (31%) compared to those without narcolepsy (IH or normal MSLTs; 0%; p < 0.01) or where narcolepsy status was unknown because an MSLT was not conducted (7%; p < 0.01).ConclusionsThe MSLT has been historically underutilized for those exhibiting a SOREMP on diagnostic PSG, a potential marker of narcolepsy. This is presumably because patients with a PSG SOREMP reported variable levels of sleepiness (although some severe) and many had some degree of OSA, which may either be a partial factor in symptomology or even obscure true narcolepsy. Some patients with a PSG SOREMP were very sleepy and most, when an MSLT was conducted, received a diagnosis of type 2 narcolepsy despite few presenting with some of the associated features of narcolepsy. Well-controlled longitudinal studies with high quality data on cataplexy and hypocretin status are needed to understand where the PSG SOREMP phenomenon falls on the hypersomnolence spectrum and to establish which comorbidities share variance with and/or potentially mask narcolepsy. However because untreated narcolepsy can have high social, functional, and financial burden, until such studies are done, physicians should consider a narcolepsy workup when a SOREMP is observed (especially if multiple are seen) as well as close follow-up for symptom resolution when, for example, a patient is treated for sleep apnea.