Two Lamps or One? An Illusionary Mirror.

We asked 100 college students to view a picture ( Figure 1 ) and decide if there were two lamps or one lamp reflected in a mirror. Although the correct answer is two lamps, the vast majority (72%) answered seeing only one lamp. We discuss this illusion.

Chikungunya infection: self-reported rheumatic morbidity and impaired quality of life persist 6 years later.

This study presents the 6-year follow-up of French gendarmes exposed to the chikungunya (CHIK) infection in 2006 on Reunion Island. The aim was to see to what extent the subjective health differences observed in 2008 (30 months after infection) between CHIK infected (CHIK+) and noninfected (CHIK-) gendarmes still persisted in 2012, and to investigate a possible return to a pre-CHIK health status for CHIK+ subjects. Gendarmes were contacted by mail in 2012 and asked to complete a self-questionnaire asking for morbidity, health care and medicines consumption since the last follow-up in 2008. Quality of life (QoL) after 6 years was evaluated using the SF-36 scale. In comparison with CHIK- subjects (n = 171), CHIK+ (n = 81) presented with higher rheumatic but also nonspecific morbidity such as headaches and fatigue associated with a large psychological impact, frequent depressive moods and social disabilities, leading to a significant impairment of the QoL and higher health care consumption. When restricted to CHIK+ subjects, comparing the data with that of 2008 showed persistent but decreasing self-reported rheumatic morbidity, and an increase over time of chronic discomfort (headache, fatigue) and depressive moods, resulting in no overall improvement in QoL. Despite possible cohort attrition bias, the comparability of CHIK+/CHIK- subjects allows the assumption of a long-term impact of CHIK infection with less chance of returning to a previous health status. Although these results may be specific to the 2006 virus strain, we recommend that public health strategies in the epidemic-prone countries include a response to the consequences of chronic post-CHIK disorders.

More severe clinical course of cardiovascular dysfunction in intensive care unit patients with the 894TT eNOS genotype.

The endothelial nitric oxide synthase (eNOS) plays an important homeostatic role in the cardiovascular system (CVS) by maintaining appropriate blood pressure through production of nitric oxide. The 894TT genotype of 894G>T (Glu298Asp, rs1799983), a polymorphic variant of eNOS, has been associated with several vascular diseases. On the basis of this strong relationship, we monitored daily 585 critically ill adult patients according to their degree of CVS dysfunction and investigated their disease progression by the 894G>T genotype. To obtain information of the general population, we obtained the 894G>T genotypic and allelic frequencies in a random group of 149 healthy subjects. The patients were genotyped for the eNOS 894G>T polymorphism and daily evaluated according to their degree of CVS dysfunction through the Cardiovascular Sequential Organ Failure Assessment (SOFA) score. The mean value of the global CVS dysfunction score was significantly higher in 894TT patients (1.35 ± 0.57) than in non-894TT patients (1.23 ± 0.37; P = 0.035). This score remained significantly higher in 894TT patients, even in different patient clusters (all patients, septic, and non-septic patients) during the 1st week at the intensive care unit (1.86 ± 0.8 versus 1.63 ± 0.62, P = 0.005; 2.32 ± 0.10 versus 2.06 ± 0.08, P = 0.009; 0.84 ± 0.09 versus 0.64 ± 0.08, P = 0.027; respectively). This result shows that the mean values of the cardiovascular SOFA score were higher in 894TT patients in all subgroups. The present study provides evidence that the 894TT eNOS genotype is associated with a higher degree of CVS dysfunction in critically ill patients.

SP/AP area ratio in the diagnosis of Ménière's disease.

Conventional analysis of the click-evoked electrocochleogram includes measurement of the amplitudes of the cochlear summating potential (SP) and auditory nerve action potential (AP) to derive the SP/AP amplitude ratio. It is now well documented that an amplitude ratio where SP is elevated relative to AP may be a positive finding for endolymphatic hydrops in patients suspected of having Ménière's disease (MD). However, the incidence of an elevated SP/AP amplitude ratio in the general MD population is only approximately 60%. This relatively low value necessitates efforts to improve the diagnostic sensitivity of electrocochleography (ECochG) for MD. A review of early and more recent literature in this area indicates that consideration of both the amplitude and duration of ECochG components may help to achieve this goal. The present study combined these features to measure the "area" of the SP-AP complex in normal and MD populations. A software routine was used to measure the amplitude x duration area of the SP-AP complex in (a) normally hearing adults with normal SP/AP amplitude ratios (Group 1), (b) confirmed MD patients with elevated SP/AP amplitude ratios (Group 2), and (c) probable MD patients with normal SP/AP amplitude ratios (Group 3). Ninety percent of the confirmed MD patients in Group 2 displayed elevated SP/AP area ratios relative to the normative value established from Group 1. In addition, almost half of the probable MD patients from Group 3 displayed elevated area ratios. These findings indicate that measurement of the SP/AP area ratio holds promise for improving the sensitivity of ECochG in the diagnosis of MD.

Effect of American ginseng (Panax quinquefolium) on male copulatory behavior in the rat.

The effects of American ginseng (Panax quinquefolium) on male rat copulatory behavior were investigated. Adult Sprague-Dawley rats were administered either 10, 50 or 100 mg/kg of Panax quinquefolium or a sesame oil vehicle per os (p.o.) for 28 days and copulatory behavior parameters were measured. Ginseng-treated male rats demonstrated a significant decrease in mount, intromission and ejaculation latencies compared to vehicle controls. Hormone analyses revealed no difference in plasma luteinizing hormone or testosterone levels between ginseng- and vehicle-treated animals; however, plasma prolactin levels were significantly reduced by all doses of ginseng tested. When male rats were treated with the 100 mg/kg dose of ginseng for 1, 14 or 28 days, mount and intromission latencies were significantly reduced at 14 and 28 days of daily ginseng treatment, whereas ejaculation latency was significantly reduced after 1 day of ginseng treatment when compared to vehicle controls. Plasma prolactin levels were also significantly decreased after 14 and 28 days of daily ginseng administration. There were no differences in body weight or in testes, seminal vesicle, anterior pituitary or spleen weights between ginseng- and vehicle-treated rats. These results demonstrate that P. quinquefolium significantly facilitates male copulatory behavior. The reduction in plasma prolactin levels suggests that ginseng-induced alterations in dopaminergic neurotransmission may play a role in the ability of P. quinquefolium to stimulate copulatory behavior in the male rat.

Effects of in-situ calibration of click stimuli on the auditory brainstem response.

We studied the effects on the auditory brainstem response (ABR) of applying a computerized calibration procedure for click stimuli that corrects for individual transducer characteristics and ear canal acoustics. The "calibrated" signal at the eardrum possesses a nearly flat spectrum from 500 to 10,000 Hz. ABRs were recorded from normal-hearing subjects using both calibrated and uncalibrated clicks. The preponderance of energy for the latter stimulus was between 1000 and 4000 Hz. When compared to the responses evoked by the uncalibrated signal, ABRs to calibrated clicks displayed shorter component latencies, increased component amplitudes, and a more sensitive wave V relative to behavioral threshold.

An improved method for precise control of light exposure at a known circadian time during an animal's subjective night.

The paper describes an electronic device that improves the feedback lighting (LDFB) developed previously. LDFB links environmental lighting conditions to locomotor or other monitored behavior. Subjective Night Light (SNL) has the following advantages over LDFB: it eliminates the multiple transitions between light and dark; it allows for precise control over lighting so that a light signal of variable duration can be phase locked to any phase of the subjective night; it dissociates to a much greater extent any potential cognitive perception of the link between locomotor activity and lighting; and it can be programmed easily. Finally, SNL retains the significant advantage of LDFB in its ability to maintain phase relationship with the endogenous biologic rhythms even in circumstances of phase-shifting or free-running conditions. The SNL system is made from components that can be purchased at most electronics outlets for less than US$100.

Cochlear potentials in clinical audiology.

The recording of cochlear and auditory nerve potentials in humans via Electrocochleography (ECochG) has emerged as a valuable tool for a variety of clinical applications. This review consolidates current research on the use of cochlear potentials and ECochG in the clinical setting and identifies several areas in need of additional study. Methodological topics discussed include a review of ECochG recording approaches (i.e. transtympanic versus extratympanic) and issues related to choice of stimuli (clicks versus tonebursts). The review of current applications for cochlear potentials focuses primarily on the use of ECochG in the identification and treatment of Ménière's disease/endolymphatic hydrops (MD/ELH). Other uses for ECochG also are presented (e.g. intraoperative monitoring, enhancement of ABR wave I, estimation of hearing sensitivity). Several suggestions are offered to maximize the predictive value of ECochG in the diagnosis of MD/ELH.

Electrocochleographic effects of ear canal pressure change in subjects with Menière's disease.

This study examined the relationship between objective changes in electrocochleographic (ECochG) parameters and subjective changes in symptoms in a group of patients with Menière's disease/endolymphatic hydrops (MD/ELH) after application of positive and negative atmospheric pressure changes to the sealed ear canal. Our goals were to further examine the therapeutic effects of atmospheric pressure change on the treatment of MD/ELH, as reported by a series of Swedish studies, and to examine the utility of ECochG for monitoring these effects. By combining a clinical immittance unit and an evoked potential unit, ECochG responses were obtained from the tympanic membrane while different atmospheric pressures were applied indirectly to the middle ear via the external ear canal. For comparison, ECochG responses at various atmospheric pressures also were obtained for otologically normal subjects. For the MD/ELH group, there was a significant (p < 0.01) reduction in the abnormal summating potential/action potential (SP/AP) amplitude ratio, although the amplitude ratios did not become "normal." There was no significant effect of ear canal pressure change on ECochG components for the normative subjects. Although these findings were encouraging regarding the therapeutic effects of overpressure, they were not accompanied with changes in MD/ELH symptoms.

Alterations in growth rate associated with a normally persisting circadian rhythm during spaceflight.

BACKGROUND: Biological clocks time many physiological parameters with periodicities close to 24 h; those which persist in the absence of environmental cues are circadian. An earlier shuttle experiment (STS-9) examined circadian pacemaker function and growth rate of Neurospora crassa and demonstrated damped rhythm amplitudes, increased variability in period lengths and altered growth rates. HYPOTHESIS: Postflight studies suggested that accelerative forces of launch could have induced rhythm alterations. Differences in growth rate may have been due to an alteration of metabolic rate. METHODS: Race tubes inoculated with bd or csp strains were flown aboard STS-32, exposed to ambient mid-deck temperatures throughout flight, and exposed to light only during marking procedures. Period, rhythm amplitude, and growth rate were determined and compared to orbital environmental controls (OES) and 25 degrees C ground controls (GC). RESULTS: Unlike the previous flight exposurement, the rhythm persisted quite normally. bd flight and OES cultures each displayed lengthened periods of a similar magnitude when compared to GC. The lengthened periods of csp flight cultures while longer than GC, were shorter than OES. Shuttle temperatures were relatively warm, however the increased period length in space was greater than predicted by the known Q10. Growth rates also increased substantially during flight, which could not be accounted for by thermal mechanisms alone. CONCLUSION: It is likely that some of the cultures may have entrained to the unexpected diurnal temperature variations; however, other cultures did not entrain, yet retained rhythmicity with increased periods. The results also suggest an increased metabolic rate during spaceflight.

Progressive neural hearing impairment: case report.

This report describes a patient whose ability to understand speech had so deteriorated over 20 years time that she was being considered for a cochlear implant, despite the fact that pure-tone sensitivity loss had not deteriorated proportionately. An unusual combination of otoacoustic emissions (OAEs) and auditory evoked potential (AEP) results are described. Click-evoked and distortion product emissions were present and normal-appearing. Auditory brainstem and middle latency responses were totally absent but the N1-P2 complex of the long-latency response was present. The case illustrates the contribution of otoacoustic emissions to site of lesion testing. It also illustrates that the manifestations of pathology can appear in certain epochs of the family of AEPs without affecting the others.

Drenagem endoscópica transduodenal de pseudocisto da cabeça do pâncreas e de coleçäo peripancreática / Transduodenal endoscopic drainage of pancreatic pseudocysts and peripancreatic collection

Até recentemente, o tratamento do pseudocisto do pâncreas era basicamente cirúrgico. Entretanto, dois acessos näo-cirúrgicos säo atualmente possíveis: a aspiraçäo percutânea sob monitorizaçäo ultra-sonográfica ou tomográfica e drenagem endoscópica. OBJETIVO. Relatar os resultados obtidos com a drenagem endoscópica e pseudocisto pancreático. MÉTODOS. Foram estudados 11 doentes com pseudocisto da cabeça do pâncreas e um caso de coleçäo paraduodenal que se originou após surto de pancreatite aguda necrotizante. A cistoduodenostomia endoscópica foi realizada na parede duodenal em contato com o pseudocisto. Foi utilizado um duodenoscópio padräo Olympus para alcançar o abaulamento da parede duodenal e para realizar a fistula diatérmica. RESULTADOS. O percentual de sucesso foi 91,7 por cento. A hemorragia ocorreu em um caso (8,3 por cento), controlada sem transfusäo de sangue. A cistoduodenostomia endoscópica foi o tratamento definitivo em 10 pacientes examinados 36 meses após o procedimento. Um paciente foi submetido a gastrojejunostomia após 14 meses por obstruçäo duodenal consequüente a surto recidivante de pancreatite. Näo havia recidiva do cisto. Näo houve óbito decorrente do procedimento endoscópico. CONCLUSAO. A cistoduodenostomia endoscópica constitui um procedimento alternativo para a drenagem de pseudocisto paraduodenal sempre que estiver restrito a indicaçäo precisa morfológica de contigüidade com abaulamento da luz do duodeno

[Transduodenal endoscopic drainage of pancreatic pseudocysts and peripancreatic collection]. / Drenagem endoscópica transduodenal de pseudocisto da cabeça do pâncreas e de coleçäo peripancreática.

Until recently, the treatment of pancreatic pseudocysts was mainly surgical. However, two non-surgical invasive approaches are now possible: percutaneous aspiration under ultrasonic or CT monitoring and endoscopic drainage. PURPOSE--To report the result obtained using endoscopic drainage of pancreatic pseudocysts. METHODS--11 consecutive patients admitted with pancreatic pseudocyst had chronic pancreatitis and 1 patient had a well defined paraduodenal collection originated from acute necrotising pancreatitis. Endoscopic cystoduodenostomy was performed in the area of close contact with the digestive wall. A standard Olympus duodenoscope was used to reach the bulging wall and to allow the diatermic fistula. RESULTS--The success rate was 91.7%. Hemorrhage occurred in 1 patient (8.3%) controlled without blood transfusion. Endoscopic cystoduodenostomy was the definitive treatment in 10 patients 36 months after the procedure. One patient underwent gastrojejunostomy after 14 months for duodenal obstruction following relapsing pancreatitis. There was no relapsing cyst. There was no death following the endoscopic procedure. CONCLUSION--the endoscopic cystoduodenostomy constitutes an alternative procedure for the drainage of paraduodenal pseudocysts whenever restricted to the precise morphological indication of paraintestinal pseudocyst bulging into the duodenal lumen.

Normal summating potential to tone bursts recorded from the tympanic membrane in humans.

The use of tone-burst stimuli for electrocochleography (ECochG) may offer certain advantages over conventional broad-band clicks. Namely, the summating potential (SP) component can be examined at different frequencies and may be easier to define and measure. To apply these findings clinically, it would first be necessary to establish SP amplitudes as a function of tone-burst frequency in normal listeners. The purpose of the present study was to do this using the tympanic membrane (TM) as the primary ECochG recording site. ECochG was recorded from 20 normal ears. Stimuli included 500-, 1000-, 2000-, 4000-, and 8000-Hz tone bursts presented randomly at 90 dB nHL. Mean SP amplitudes at these frequencies were +0.19, +0.17, +0.08, +0.10, and +0.22 microvolts, respectively. Although mean amplitudes were slightly positive regarding baseline, individual amplitudes varied between -0.41 and +0.73 microvolts. This study offers additional evidence that the SP to tone bursts can be recorded from the TM. The normative data provided should be useful for extended studies involving clinical populations.

Human summating potential to tone bursts: observations on tympanic membrane versus promontory recordings in the same patients.

Electrocochleographic responses to tone bursts and clicks were recorded from the tympanic membranes (TMs) and promontories of six suspected Meniere's patients. Although the majority of ears had normal summating potentials (SPs), regardless of recording site and stimulus type, some displayed amplitude-enlarged SPs at both sites and to both types of stimuli. The following observations were made from these patients regarding the choice of recording approaches and stimuli for ECochG: (1) Although SP amplitudes at the promontory were approximately four times larger than corresponding TM values, response "patterns" leading to diagnostic interpretation were the same at both sites; (2) the majority of patients who displayed enlarged SP amplitudes to tone bursts also had enlarged SPs to clicks; and (3) with tone-burst stimuli, the amplitude of the SP alone was sufficient for diagnostic interpretation of the ECochG waveform.

Prolonged I-III interwave interval in cerebellar astrocytoma.

We are reporting the case of a 41-year-old female diagnosed with a cerebellar astrocytoma. The tumor was detected after the patient was referred for MRI scan because of an abnormal ABR. The ABR was unusual as the I-V interwave intervals (IWIs) were within normal limits bilaterally, but the I-III IWI was prolonged by .40 msec on the left ear in comparison to the right ear. This case report illustrates the importance of the I-III IWI in the detection of retrocochlear pathology and the nonsequential generation of the components of the ABR.

Delayed endolymphatic hydrops following acoustic tumor removal with intraoperative and postoperative auditory brainstem response improvements.

A 36-year-old female with delayed endolymphatic hydrops (ELH) after acoustic tumor removal of the same ear is reported. She presented at our clinic with pressure, fullness, and tinnitus involving her right ear. She had an abnormal auditory brainstem response (ABR), and a computed tomography showed a right acoustic tumor. She underwent a complete tumor removal from a suboccipital incision with significant intraoperative and postoperative ABR improvements. Preoperatively, there was no fluctuation in her hearing and her electrocochleography (ECoG) was normal. She did well postoperatively, but 18 months after the tumor surgery she complained of noticeable fluctuating hearing loss with increased tinnitus and aural fullness of her right operated ear and nausea but no vertigo. Neurotological examinations showed a positive right urea dehydration and positive right ECoG for enhanced summating potential to clicks. She was diagnosed as cochlear Meniere's disease with delayed ELH, failed medical management and then underwent a valved shunt surgery for ELH to stabilize her hearing. Eight years after her acoustic tumor surgery and 6 and a half years after her ELH surgery she has stabilized hearing with normal ABR and ECoG. Her clinical course is presented and a pathogenesis of ELH is discussed.

Thermoregulatory responses of rhesus monkeys during spaceflight.

This study examines the activity, axillary temperature (T(ax)), and ankle skin temperature (Tsk) of two male Rhesus monkeys exposed to microgravity in space. The animals were flown on a Soviet biosatellite mission (COSMOS 1514). Measurements on the flight animals, as well as synchronous flight controls, were performed in the Soviet Union. Additional control studies were performed in the United States to examine the possible role of metabolic heat production in the T(ax) response observed during the spaceflight. All monkeys were exposed to a 24-h light-dark cycle (LD 16:8) throughout these studies. During weightlessness, T(ax) in both flight animals was lower than on earth. The largest difference (0.75 degree C) occurred during the night. There was a reduction in mean heart rate and Tsk during flight. This suggests a reduction in both heat loss and metabolic rate during spaceflight. Although the circadian rhythms in all variables were present during flight, some differences were noted. For example, the amplitude of the rhythms in Tsk and activity were attenuated. Furthermore, the T(ax) and activity rhythms did not have precise 24.0 hour periods and may have been externally desynchronized from the 24-h LD cycle. These data suggest a weakening of the coupling between the internal circadian pacemaker and the external LD synchronizer.