An electrophysiological investigation of factors facilitating strategic recollection

Episodic memory is thought to be mediated by executive processes that facilitate the retrieval of task-relevant information at the expense of irrelevant information. The exclusion task [A process dissociation framework: Separating automatic from intentional uses of memory. Journal of Memory and Language, 30, 513-541, 1991] can be used to explore these processes. In this task, studied items from one source ("targets") are endorsed on one response key, whereas new and studied items from another source ("nontargets") are rejected on another key. Herron and Rugg [Strategic influences on recollection in the exclusion task: Electrophysiological evidence. Psychonomic Bulletin and Review, 10, 703-710, 2003] reported that nontargets elicited the ERP correlate of recollection (the "left parietal old/new effect") when target accuracy was low, but not when it was high. Their explanation for this was that participants only focused exclusively on the recollection of target information when the likelihood of target recollection was high, as under these conditions this strategy is one that that will give rise to accurate task performance. The fact, however, that targets were encoded in different tasks in the high- and low-accuracy groups means that the results can also be explained in terms of the encoding operations performed at study rather than in terms of target accuracy. This study was designed to distinguish between these competing accounts. All targets were encoded elaboratively. Target accuracy was reduced in one condition with a 40-min study-test interval. Nontargets elicited no left parietal effect in either condition, suggesting that target-specific strategic retrieval is facilitated by certain classes of encoding operations rather than simply high target accuracy per se.     

Septic, CD-30 positive febrile ulceronecrotic pityriasis lichenoides et varioliformis acuta

We report life-threatening febrile ulceronecrotic pityriasis lichenoides et varioliformis acuta in an 8-year-old girl. Hemorrhagic-crusted papules and plaques covered over 90% of the patient's body, leaving her susceptible to Pseudomonas aeruginosa and Staphylococcus epidermidis bacteremia as well as Candida parapsilosis fungemia. Sepsis delayed definitive treatment of the underlying cutaneous disease for 2 weeks. Combined therapy with methotrexate and cyclosporin caused remission of the process. Although immunohistochemistry revealed CD-30 positive cells, suggesting the diagnosis of lymphomatoid papulosis, the histopathology was most compatible with pityriasis lichenoides et varioliformis acuta. A partial loss of CD2 and CD5 in the predominant CD3 T-cell lymphocytes suggested a clonal proliferation. Elevated soluble interleukin-2 receptor levels reflected marked T-cell activation, and the downward trend of the levels during treatment coincided with clinical regression of this inflammatory dermatosis.     

Fractional photothermolysis: a new concept for cutaneous remodeling using microscopic patterns of thermal injury

BACKGROUND AND OBJECTIVES: We introduce and clinically examine a new concept of skin treatment called fractional photothermolysis (FP), achieved by applying an array of microscopic treatment zones (MTZ) of thermal injury to the skin. STUDY DESIGN/MATERIALS AND METHODS: Two prototype devices emitting at 1.5 microm wavelength provided a pattern of micro-exposures with variable MTZ density. Effects of different MTZ densities were tested on the forearms of 15 subjects. Clinical effects and histology were assessed up to 3 months after exposure. Treatment of photoaged skin on the periorbital area in an additional 30 subjects receiving four treatments over a period of 2-3 weeks was also tested. Tissue shrinkage and clinical effects were assessed up to 3 months after treatment. RESULTS: Pattern densities with spacing of 250 microm or more were well tolerated. Typical MTZ had a diameter of 100 microm and penetrated 300 microm into the skin. Reepithelialization was complete within 1 day. Clinical effects were assessed over a 3-month period. Histology at 3 months revealed enhanced undulating rete ridges and increased mucin deposition within the superficial dermis. Periorbital treatments were well tolerated with minimal erythema and edema. Linear shrinkage of 2.1% was measured 3 months after the last treatment. The wrinkle score improved 18% (P < 0.001) 3 months after the last treatment. CONCLUSIONS: FP is a new concept for skin restoration treatment. Safety and efficacy were demonstrated with a prototype device. Further clinical studies are necessary to refine the optimum parameters and to explore further dermatological applications.     

Sensory dysfunction in the great toe in hallux valgus

Injury to the dorsomedial cutaneous nerve in the foot may occur after operations for hallux valgus. Pressure neuropathy before operation is also described but remains largely unexplored. We have investigated the incidence of sensory deficit in the great toe before operating for hallux valgus and examined to what extent any deficit was related to the degree of angulation of the joint. Forty-three patients with a total of 61 great toes with hallux valgus presenting for consideration of surgical correction had their sensation tested in pre-designated zones using a five-filament set of Semmes-Weinstein monofilaments. These allowed good inter-observer reliability with an intra-class correlation coefficient of 0.84. Sensory symptoms were noted by only 21% of the patients, a measurable reduction in sensation by one monofilament grade or more was found in an additional 44%. No relationship was found between the degree of sensory loss and the degree of angulation. Patients with symptomatic hallux valgus may have sensory loss in the toe without being aware of it. Normal subjective sensation does not reliably predict normal sensory function. Given the potentially high rates of nerve damage following operations for hallux valgus, we recommend objective sensory testing as part of routine assessment before surgery.     

Sonovue improves endocardial border detection and variability in assessing wall motion score and ejection fraction during stress echocardiography

Background Stress echocardiography is useful for assessing patients with coronary artery disease unable to undergo formal exercise testing. Considerable skill is required to avoid large intra- and inter-observer variability due to poor endocardial definition. Intravenous ultrasound contrast agents are now available which may improve this variability. Aim To study intravenous Sonovue in assessing wall motion score and ejection fraction (EF) during stress echocardiography. Methods Thirty-eight patients undergoing arbutamine stress echocardiography for known or suspected coronary artery disease were studied. Echocardiographic analysis of wall motion score index, endocardial border detection (EBD) and EF was performed at rest and at peak stress before and after intravenous injection of Sonovue, by experienced and inexperienced observers. Results All three observers noted an improvement in endocardial border definition following Sonovue (p=<0.001). At baseline, there was a significant difference in wall motion score index between experienced and inexperienced observers at rest (p=0.01) and at peak stress (p=0.001). Following Sonovue administration this was no longer significant (p=0.07, p=0.114). Intra-observer variability of end diastolic, end systolic volumes (ESV) and EF improved following contrast (p<0.05) at rest and during stress. Conclusion Sonovue significantly improved EBD and reduced intra-observer variability of EF at rest and during peak arbutamine infusion.     

Residence,income and cancer hospitalizations in British Columbia during a decade of policy change

BACKGROUND: Through the 1990s, governments across Canada shifted health care funding allocation and organizational foci toward a community-based population health model. Major concerns of reform based on this model include ensuring equitable access to health and health care, and enhancing preventive and community-based resources for care. Reforms may act differentially relative to specific conditions and services, including those geared to chronic versus acute conditions. The present study therefore focuses on health service utilization, specifically cancer hospitalizations, in British Columbia during a decade of health system reform. METHODS: Data were drawn from the British Columbia Linked Health Data resource; income measures were derived from Statistics Canada 1996 Census public use enumeration area income files. Records with a discharge (separation) date between 1 January 1991 and 31 December 1998 were selected. All hospitalizations with ICD-9 codes 140 through 208 (except skin cancer, code 173) as principal diagnosis were included. Specific cancers analyzed include lung; colorectal; female breast; and prostate. Hospitalizations were examined in total (all separations), and as divided into first and all other hospitalizations attributed to any given individual. Annual trends in age-sex adjusted rates were analyzed by joinpoint regression; longitudinal multivariate analyses assessing association of residence and income with hospitalizations utilized generalised estimating equations. Results are evaluated in relation to cancer incidence trends, health policy reform and access to care. RESULTS: Age-sex adjusted hospitalization rates for all separations for all cancers, and lung, breast and prostate cancers, decreased significantly over the study period; colorectal cancer separations did not change significantly. Rates for first and other hospitalizations remained stationary or gradually declined over the study period. Area of residence and income were not significantly associated with first hospitalizations; effects were less consistent for all and other hospitalizations. No interactions were observed for any category of separations. CONCLUSIONS: No discontinuities were observed with respect to total hospitalizations that could be associated temporally with health policy reform; observed changes were primarily gradual. These results do not indicate whether equity was present prior to health care reform. However, findings concur with previous reports indicating no change in access to health care across income or residence consequent on health care reform.     

Safety of desloratadine syrup in children

BACKGROUND: Allergic rhinitis (AR) and acute urticaria are common childhood maladies. Typically, the firstline treatment options for both include non-sedating antihistamines. First-generation antihistamines, such as diphenhydramine and hydroxyzine, although useful, cause sedation. Desloratadine, an oral non-sedating antihistamine, has been shown in multiple studies to be safe and effective in relieving the symptoms of AR and chronic idiopathic urticaria (CIU) in adults and adolescents. OBJECTIVE AND METHODS: The current double-blind, placebo-controlled, parallel-group, single-center studies were undertaken to determine the safety and tolerability of desloratadine syrup in children aged 2 years-11 years with AR or CIU. Over 14 days, subjects aged 2 years-5 years were randomly assigned to receive once a day either 1.25 mg of desloratadine syrup (0.5 mg/mL) or matching placebo, and subjects aged 6 years-11 years were randomly assigned to receive once a day either 2.5 mg of desloratadine syrup or matching placebo. Safety evaluations included adverse event report collection, monitoring of vital signs, clinical laboratory measurements, and standard 12-lead electrocardiogram (ECG) measurements. RESULTS: In the study involving subjects aged 2 years-5 years (n = 111), the incidence of adverse events was 7/55 for the group treated with desloratadine and 6/56 for placebo. In the study involving subjects aged 6 years-11 years (n = 120), the incidence of adverse events was 1/60 for the group treated with desloratadine and 6/60 for placebo. No severe or serious adverse events occurred, and no clinically relevant changes were noted in median clinical laboratory test values or mean vital signs in either group. ECG results from both age groups demonstrated no significant changes (p = NS) in mean ventricular rate or PR, QRS, or QT. No subjects had a Fridericia QT(c) interval > 440 ms at day 8 or day 15. CONCLUSION: These studies demonstrate the safety of desloratadine syrup in children aged 2 years-11 years with AR or CIU.     

The surgical management of severe obesity

The prevalence of obesity in the United States is increasing to epidemic proportions. At present, more than 60% of Americans are overweight. While a variety of medications are available for the treatment of obesity, none results in the long-term loss of more than 10% of body weight. The current standard for the treatment of severe obesity, defined as a body mass index of greater than 35 40 kg/m 2, is surgical. Several surgical procedures are currently available, including gastric bypass, biliopancreatic diversion with duodenal switch, and the adjustable gastric band. These operations may be performed using laparoscopic surgical techniques to minimize perioperative morbidity and postoperative recovery time. To optimize the outcome of this type of procedure, bariatric surgery should be performed on carefully selected patients, in centers specially equipped to care for the obese, within a broadly based, multidisciplinary setting providing lifelong postoperative care.     

Nicotine enhances the depressive actions of A beta 1-40 on long-term potentiation in the rat hippocampal CA1 region in vivo

Hippocampal long-term potentiation (LTP) is a form of synaptic plasticity used as a cellular model of memory. Beta amyloid (A beta) is involved in Alzheimer's disease (AD), a neurode-generative disorder leading to cognitive deficits. Nicotine is also claimed to act as a cognitive enhancer. A beta is known to bind with high affinity to the alpha 7-nicotinic acetylcholine receptor (nAChR). Here we have investigated the effect of intracerebroventricular (i.c.v.) injection of the endogenous peptide A beta 1-40 on LTP in area CA1 of urethananesthetized rats. We also examined the effect of A beta 12-28 (i.c.v.), which binds with high affinity to the alpha 7-nAChR and the specific alpha 7-nAChR antagonist methyllycaconitine (MLA) on LTP. We found that A beta 12-28 had no effect on LTP, whereas MLA depressed significantly LTP, suggesting that activation of the alpha 7-nAChR is a requirement for LTP. Within the in vivo environment, where other factors may compete with A beta 12-28 for binding to alpha 7-nAChR, it does not appear to modulate LTP. To determine if the depressive action of A beta 1-40 on LTP could be modulated by nicotine, these agents were also co-applied. Injection of 1 or 10 nmol A beta 1-40 caused a significant depression of LTP, whereas nicotine alone (3 mg/kg) had no effect on LTP. Co-injection of nicotine with A beta 1-40 1 h prior to LTP induction caused a further significant depression of LTP compared with A beta 1-40 alone. These results demonstrate that nicotine enhances the deficit in LTP produced by A beta 1-40. This then suggests that nicotine may exacerbate the depressive actions of A beta on synaptic plasticity in AD.