Why is there a left side underestimation in rod bisection?

Subjects set the extremities of a horizontal rod to appear equidistant from a central reference point, with or without central fixation. On either side, the contrast (salience) of the rod against the background was high or low. Extents to the left were set smaller than those to the right, an effect (LSU) which was stronger with central fixation, indicating that both hemispatial and anatomical pathway factors contribute. Reduced salience on the left increased rather than decreased the LSU, indicating the importance of attentional factors.     

Grading static versus dynamic images of contact lens complications

Background: This study was conducted to investigate grading performance when estimating the severity of static versus dynamic images of contact lens‐related ocular pathology. Methods: Thirty‐eight subjects used the Efron Grading Scales for Contact Lens Complications to grade the severity of ocular pathological changes depicted in static and dynamic (movie clip) computer‐displayed images of each of the following contact lens complications: bulbar conjunctival redness, limbal redness, papillary conjunctivitis, corneal staining, corneal infiltrates and meibomian gland dysfunction. The viewing of static and dynamic images was separated by seven weeks. Results: Grades assigned to dynamic images were 0.6 and 0.7 grading scale units higher than those assigned to static images for limbal redness and papillary conjunctivitis, respectively (p < 0.0001 for both). No difference was observed for the other four complications. There was an apparent trend for grading variability to be reduced (that is, observers grading in closer agreement) when grading dynamic versus static images. Conclusions: Absolute grades based on an assessment of signs of pathology represented in static images may, in some instances, underestimate the true severity of the condition.     

The clinical utility of provocative radionuclide oesophageal transit in the evaluation of non-cardiac chest pain.

We combined edrophonium provocative testing with the technique of radionuclide oesophageal transit (RET) in 30 consecutive patients with non-cardiac chest pain (NCCP) and 12 controls. The oesophageal transit time of aqueous technetium-99m sulfur colloid was determined before and after intravenous infusion of 80 micrograms/kg edrophonium chloride (ED). Patient symptoms during provocative RET (P-RET) were recorded. Thirteen (43%) of the patients had abnormal study results, whereas all control subjects had normal results. Three groups considered abnormal were observed: (a) in two patients (6%), the pain was reproduced and transit pre- and post-ED administration was prolonged (greater than 15 s); (b) in six patients (20%), the pain was reproduced, but transit was normal pre- and post-ED; (c) in five patients (17%), transit pre- and post-ED was prolonged, but no pain was reproduced. In five patients (17%), ED prolonged the transit time greater than 15 s without pain, but the baseline transit was normal. Transit time was measurable in 23 patients. Mean pre-ED transit time was 10.2 +/- 7.4 s (mean +/- SD) and post-ED, 12.4 +/- 8.0 s (P = 0.3). We conclude that ED has no significant effect on transit time, and the pain induced by ED rarely correlates with an abnormal transit; P-RET provides additional information to baseline RET, increasing sensitivity, and may be a useful screening method in the evaluation of patients with NCCP.     

Cosmetic rhinoplasty using the external approach

Although the external rhinoplasty remains controversial it is difficult to understand why. The columella scar is of little significance since this becomes nearly invisible if the closure is carefully performed. There is a relative postoperative prolongation of nasal tip swelling in comparison with the closed technique, however this also becomes negligible with time. On the other hand, in our experience the open approach will achieve better understanding of the patient's individual anatomy and thus lead to a more predictable result through increased exposure and precision tailoring. The external technique facilitates the application of the great variety of tip refinements that have been developed over the years to allow facial plastic surgeons to get consistently excellent results in rhinoplasty.     

Old and homeless: a review and survey of older adults who use shelters in an urban setting.

OBJECTIVES: Research on the mental health and service needs of homeless seniors has been scant. This paper reviews the available literature and presents findings of a Toronto survey in an effort to describe the demographics of homeless seniors, their level of impairment, and their mental and physical health needs. METHODS: We searched the Medline, AgeLine, and PsycINFO databases, using the following key words: elderly homeless, elderly hostel users, and urban geriatrics. To better describe the service needs of the elderly homeless, we obtained demographic data from the Community and Neighbourhood Services Department and distributed a survey questionnaire to 11 Toronto hostel directors. The questionnaire elicited data relating to reasons for shelter use, problem behaviours, and mental health needs of those over age 65 years. RESULTS: Although seniors represent a small percentage of the homeless population, their numbers are growing. The available literature suggests a high prevalence of psychiatric disorders and cognitive impairment in this population, with a greater proportion of older women than men having severe mental illness. Further, our survey suggests that the service needs of elderly hostel users in Toronto differ from those of their younger counterparts. CONCLUSION: The homeless elderly are the most vulnerable of this impoverished population. Although more research is needed to define their mental and physical health needs and ways of meeting them, their characteristics appear to be unique. Geriatric psychiatrists could play a significant role in evaluating and treating this population more comprehensively.     

Postoperative naproxen after coronary artery bypass surgery: a double-blind randomized controlled trial.

OBJECTIVE: Non-steroidal anti-inflammatory drugs (NSAIDs) are routinely used after coronary artery bypass surgery (CABG), yet their effects have seldom been evaluated in randomized controlled settings. The aim of this study was to examine the efficacy and safety of a commonly used NSAID, naproxen. We hypothesized that naproxen would reduce postoperative pain following CABG without increasing complications. METHODS: Patients (N=98) undergoing primary CABG were randomized to receive naproxen (500 mg q12hX5 doses via suppository started 1h after operation, followed by oral 250 mg q8hX6 doses) or placebo. Standard analgesic and anti-emetic regimens were available to both patient groups. Interventions were double-blinded. Primary end-points were postoperative pain measured before and after chest physiotherapy by visual analog scale and pulmonary slow vital capacity (SVC). RESULTS: Baseline characteristics were equivalent between the two groups. Over the first 4 postoperative days, naproxen decreased pain by 47+/-17% on average before chest physiotherapy (P=0.034), and 44+/-13% after chest physiotherapy (P=0.0092). Patients who received naproxen also had better preservation of SVC over the first 4 postoperative days (mean loss of SVC from baseline: 2.1+/-0.1 vs. 2.5+/-0.1l, naproxen vs. placebo, P=0.0032). This was concomitant with a lower white blood cell count observed in naproxen patients (9.2+/-0.3 vs. 12.7+/-1.5x10(9)/l, naproxen vs. placebo, P=0.03). Patients who received naproxen had more chest tube drainage after 4h postoperatively, but there was no difference in the incidence or amount of transfusions. There was no difference in medication use, length of stay, or in the incidence of atrial fibrillation, azotemia, and other complications. CONCLUSIONS: Naproxen is an effective and low-cost adjunct for optimization of pain control and lung recovery after CABG. Its use may result in increased chest tube drainage, but no apparent increase in other complications.     

Influence of Hemorrhagic Shock Followed by Crystalloid Resuscitation on Propofol: A Pharmacokinetic and Pharmacodynamic Analysis

Background: Previous work has demonstrated that ongoing hemorrhagic shock dramatically alters the distribution, clearance, and potency of propofol. Whether volume resuscitation after hemorrhagic shock restores drug behavior to baseline pharmacokinetics and pharmacodynamics remains unclear. This is particularly relevant because patients suffering from hemorrhagic shock are typically resuscitated before surgery. To investigate this, the authors studied the influence of an isobaric bleed followed by crystalloid resuscitation on the pharmacokinetics and pharmacodynamics of propofol in a swine model. The hypothesis was that hemorrhagic shock followed by resuscitation would not significantly alter the pharmacokinetics but would influence the pharmacodynamics of propofol.

Methods: After approval from the Animal Care Committee, 16 swine were randomly assigned to control and shock-resuscitation groups. Swine randomized to the shock-resuscitation group were bled to a mean arterial blood pressure of 40 mm Hg over a 20-min period and held there by further blood removal until 42 ml/kg of blood had been removed. Subsequently, animals were resuscitated with lactated Ringer's solution to maintain a mean arterial blood pressure of 70 mm Hg for 60 min. After resuscitation, propofol (750 [mu]g[middle dot]kg-1[middle dot]min-1) was infused for 10 min. The control group underwent a sham hemorrhage and resuscitation and received propofol at the same dose and approximate time as the shock-resuscitation group. Arterial samples (20 from each animal) were collected at frequent intervals until 180 min after the infusion began and were analyzed to determine drug concentrations. Pharmacokinetic parameters for each group were estimated using a three-compartment model. The electroencephalogram Bispectral Index Scale was used as a measure of drug effect. Pharmacodynamics were characterized using a sigmoid inhibitory maximal effect model.

Results: The raw data demonstrated minimal differences in the mean plasma propofol concentrations between groups. The compartment analysis revealed some subtle differences between groups in the central and slow equilibrating volumes, but the differences were not significant. Hemorrhagic shock followed by resuscitation shifted the concentration effect relationship to the left, demonstrating a 1.5-fold decrease in the effect-site concentration required to achieve 50% of the maximal effect in the Bispectral Index Scale.     

Does the Amygdala Mediate Anesthetic-induced Amnesia?: Basolateral Amygdala Lesions Block Sevoflurane-induced Amnesia

Background: Amnesia for aversive events caused by benzodiazepines or propofol depends on the basolateral amygdala (BLA). Whether the amnesia of volatile anesthesia is also mediated through the BLA is unknown. If so, a general principle of anesthetic-induced amnesia may be emerging. Here, using an inhibitory avoidance paradigm, the authors determine whether BLA lesions prevent sevoflurane-induced amnesia.

Methods: Male Sprague-Dawley rats were separated into two groups: sham-operated controls (n = 22) and rats given bilateral N-methyl-d-aspartate lesions of the BLA (n = 32). After a 1-week recovery, the rats were randomly assigned to be trained during either air or sevoflurane (0.3% inspired, 0.14 minimum alveolar concentration) exposure. Animals learned to remain in the starting safe compartment of a step-through inhibitory avoidance apparatus for 100 consecutive seconds by administering foot shock (0.3 mA) whenever they entered an adjacent shock compartment. Memory was assessed at 24 h. Longer latencies to enter the shock compartment at 24 h imply better memory.

Results: Sham-air (n = 10) animals had a robust memory, with a median retention latency of 507 s (interquartile range, 270-600 s). Sham-sevoflurane (n = 6) animals were amnesic, with a latency of 52 s (27-120 s) (P < 0.01, vs. sham-air). Both the air-exposed (n = 5) and the sevoflurane-exposed (n = 8) animals with BLA lesions showed robust memory, with latencies of 350 s (300-590 s) and 378 s (363-488 s), respectively. The latencies for both did not differ from the performance of the sham-air group and were significantly greater than the latency of the sham-sevoflurane group (both P < 0.01).