Response-time corrected averaging of event-related potentials.

OBJECTIVE: The present study presents a novel approach to averaging of event-related potentials (ERPs). Acknowledging latency variability of late ERP components as related to performance fluctuations across trials should improve the assessment of late portions of the ERP. METHODS: Prior to the averaging procedure stimulus-to-response epochs in the electroencephalogram (EEG) were expanded/compressed in time to match mean RT in a certain condition and participant. By means of several mathematical functions RT variability was differentially distributed over late vs. early portions of the ERP. Data from 20 participants from two conditions of an identity-based priming task were analyzed using traditional stimulus- and response-locked averaging, as well as four different RT-corrected averaging procedures. RESULTS: Area under the curve as an index of precision of LPC assessment was reliably enhanced for certain RT-corrected procedures relative to traditional ERP averaging. Moreover, a priming effect on amplitude of a distinct LPC subcomponent which could not be confirmed with traditional stimulus-locked averaging was reliably born out using a cubic RT-correction procedure. CONCLUSIONS: RT-corrected ERP averaging can outperform traditional ERP averaging in the assessment of late portions of the ERP, and experimental effects upon. SIGNIFICANCE: Cognitive ERP researchers may take advantage of the improved capability of RT-corrected averaging to establish experimental effects on amplitudes in the late ERP range.     

Self‐Neglect: A Proposed New NANDA Diagnosis

PURPOSE. To propose a new NANDA diagnosis, self‐neglect. DATA SOURCES. Research studies and literature published from a variety of disciplines including nursing as well as primary research. DATA SYNTHESES. This diagnosis can be used to describe a constellation of self‐care problems of varying severity and impact on the health and well‐being of people who self‐neglect. Included are two subtypes of self‐neglect based on the degree of intentionality. Clarification of self‐neglect is long overdue because self‐neglect presents conceptual, identification, and intervention problems for nurses, healthcare workers, and for medicolegal systems across settings and in many countries. CONCLUSION. The proposed diagnosis, self‐neglect, fills a gap in current standardized terminology. This diagnosis will contribute significantly to nurses leading the way in the explication of an interdisciplinary and international health concern. PRACTICE AND POLICY IMPLICATIONS. Developing self‐neglect as a recognized nursing label is vital to clinicians and policy makers within and across countries. Appreciating less serious/non‐life‐threatening presentations will give nurses a care perspective to improve the health and well‐being of those in earlier stages of self‐neglect. Definitions for this phenomenon will contribute to care planning and interventions, leading to consistency in practice and research.     

Incidence of cervical dyskaryosis in Ireland: report of a five-year audit

The implementation of a national cervical screening programme in Ireland will require agreement on achievable standards in reporting cervical cytology similar to those published by the NHS cervical screening programme. Due to the opportunistic nature of screening in the Republic of Ireland, national incidence figures for uterine cervical disease are not available. An audit of our practice was performed to find the incidence of human papilloma virus related cervical disease in our population. Our laboratory reported 158,066 cases from 1996-2000. The overall rate of dyskaryosis increased from 3.6% to 7.9%, mostly due to increased low grade dyskaryosis (up from 2.3% to 6.0%). High grade dyskaryosis also increased (from 1.3% to 1.9%), particularly in the under-25 year age group who account for a growing proportion of high grade dyskaryosis (from 15.4% of all high grade diagnoses in 1996 to 23.0% in 2000). The positive predictive value of a diagnosis of high grade dyskaryosis remained stable between 76.0 and 79.5%. While opportunistic screening data may not be directly applicable to the entire screening population it is hoped that these data may form a foundation on which to estimate national incidence figures and define achievable standards for cervical screening cytology in Ireland.     

Morphine Stimulates Mesangial Cell TNF-α and Nitrite Production

Background: Intravenous opiate abusers are susceptible to develop heroin and HIV-associated nephropathies; however, the role of opiates in the development of these kidney lesions is not clear. Patients with opiate addiction are prone to recurrent infections. Methods: The effect of morphine was studied on the generation of TNF- with or without LPS (lipopolysaccharide) by cultured mouse mesangial cells. In addition, the effect of morphine was evaluated on mesangial cell nitrite production. To evaluate the role of opiate receptors, we studied the effect of naloxone and naltrexone on mesangial cell TNF- and nitrite production. To determine the role of TNF- on mesangial cell nitrite production, we examined the effect of anti-TNF- antibody on morphine-induced nitrite production. Assay of TNF- and nitrite production was carried by ELISA and Griess method respectively. Results: Morphine alone did not enhance the generation of TNF- by mesangial cells, however, an enhanced (P < 0.001) TNF- production was observed when mesangial cells were first treated with morphine for 18 h and then activated further with LPS. Maximum release of TNF- was seen at a concentration of 10^–12 M of morphine. Opiate receptor antagonists (naloxone and naltrexone) inhibited the effect of morphine. Morphine also amplified (P < 0.0002) the effect of LPS on mesangial cell nitrite production. Anti-TNF- antibody attenuated morphine induced nitrite generation. Conclusion: We conclude that morphine stimulates the generation of TNF- by LPS-activated mesangial cells. This effect of morphine seems to be opiate receptor mediated and has a downstream effect in the form of mesangial cell nitrite generation. The present in vitro study provides the basis for a hypothesis that morphine may be playing a role in the development of heroin and HIV-associated nephropathies.     

Eosinophil-enriched inflammatory response to schistosomula in the skin of mice immune to Schistosoma mansoni.

Exposure of the mouse skin to Schistosoma mansoni cercariae gives rise to acute, exudative inflammation in both normal and immune mice, but the immune response is anamnestically accelerated and is oesinophil-enriched, thereby enhancing opportunities for tegumental contact of schistosomula with host leukocytes, particularly with eosinophils. Many of the inflammatory changes occurring within the first 48 hours after exposure are due to cercarial products, e.g., "penetration tracts," but some remain demonstrable when schistosomula metamorphosed in vitro are injected intradermally and are therefore directed against the schistosomula themselves, such as the leukocyte "streaming patterns" seen in their pathways. In contrast to earlier observations in primates, cellular responses to schistosomula in the mouse lung 4 days after penetration are minimal in either normal or immune mice. Thus, immune cellular responses to schistosomula in mice are limited to an early time period after cercarial penetration and are morphologically suggestive of an antibody-mediated response rather than of delayed hypersensitivity. Our observations complement earlier evidence suggesting that antibody-mediated host leukocyte contact with schistosomula initiates the killing of challenge parasites in immune mice, with the eosinophil probably playing a crucial role.     

Altered monocyte function in uremia

Uremia appears to suppress immune function predisposing patients to infections. When the defect in cellular immunity was studied by exposing mononuclear cells (MNC) from uremic patients and controls to tetanus toxoid, diptheria toxoid, or Candida albicans antigen in vitro, the uremic cells were far less responsive. Monocytes and T cells, which are both involved in the proliferative response to soluble antigens, were isolated from MNC of uremic patients and HLA class II matched controls and incubated with tetanus toxoid. Tetanus toxoid-pulsed uremic monocytes were unable to stimulate the proliferation of HLA identical control T lymphocytes. Lymphocytes from uremic patients, however, were stimulated by tetanus toxoid-pulsed control monocytes. Therefore, the ability of monocytes to function as accessory cells is severely affected by uremia. The uremic monocytes were FcR+, produced IL-1 beta, and expressed levels of HLA class II antigens comparable to controls. Although the biochemical defect in uremic monocytes remains unknown, the abnormality could explain many of the immunological changes of uremia.     

Experimental mechanical and histologic evaluation of the Kennedy ligament augmentation device

Reconstruction of the knee with a chronic injury to the anterior cruciate ligament is an unsolved problem. Biologic graft substitutes have failed to maintain knee stability in the longer postreconstruction intervals. In an attempt to overcome the limitations in graft performance, synthetic materials have been proposed to augment the biologic tissue. In this study, a 6-mm polypropylene braid Ligament Augmentation Device (LAD) possessing a tensile strength of 1500 N and excellent fatigue and creep properties was investigated as an adjunct to the MacIntosh/Marshall Over-the-Top repair. A two-year animal study of 54 adult goats was conducted in which experimental ACL defects were created and reconstructed with a transplant consisting of a portion of the rectus femoris tendon, prepatellar tissue, and the central one-third of the patellar tendon. The goats were equally divided between nonaugmented and LAD-augmented groups and sacrificed at three, six, 12, and 24 months after surgery. Mechanically, the augmented transplants were substantially stronger at the time of initial implantation (364N versus 26N) and again at two years (841N versus 528N). Intermediate times did not demonstrate a difference in strength. Histologically, the augmented transplants consisted of a loosely organized fibrous capsule surrounding the LAD. At 24 months, "insertion fibers" were noted to provide continuity between the fibrous tissue and bone on both the tibia and femur.