Search deficits in neglect patients are dependent on size of the visual scene.

Patients with hemispatial neglect are impaired at moving their attention to a target on the contralesional display side. In the present study, visual display area was varied independently of the number of items displayed within the area. Patients searched for the absence of a simple visual feature in displays that produce serial search performance in normals. The contralesional delay was enhanced for stimulus arrays that were distributed over a larger display area, which suggests that neglect is more severe when attention has to be moved over a larger distance. The directional disengage deficit in neglect therefore depends on the target's relative position within a display, the number of ipsilesional items competing for attention, and the distance of the contralesional attention movements. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cell binding and internalization by filamentous phage displaying a cyclic Arg-Gly-Asp-containing peptide

Ligands that bind mammalian cell surface integrins with high affinity can mediate cellular internalization. We show that particles of the bacteriophage fd that display the cyclic integrin-binding peptide sequence GGCRGDMFGC in a proportion of their major coat protein subunits bind to cells and are efficiently internalized. In the displayed peptide the conformation of the RGD motif is restricted within a hairpin loop formed by a disulfide bridge between the 2 cysteine residues. Cellular internalization of phage was demonstrated by confocal and non-confocal immunofluorescence microscopy of tissue-cultured cells incubated with phage particles. The phage were contained in juxtanuclear vesicles in the same serial sections as transferrin receptor but were not colocalized with the cell surface marker alkaline phosphatase. Cell binding and internalization was inhibited by preincubation of cells with the integrin-binding peptide GRGDSP, whereas the control peptide GRGESP had no inhibitory effect. These results indicate that cyclic integrin-binding peptides can be used to target and enter cells and that it should be possible to exploit such peptides for the introduction of DNA, drugs, or other macromolecules.     

HIV-1 and bleach

The high proportion of diabetic patients is partly responsible for the high frequency of chronic renal failure in Reunion. The confection and maintenance of an arterio-venous fistule is a major problem in those patients. We report herein our experience with temporary vascular access by internal jugular vein catherization with subcutaneous tunnelization using silastic catheters. The mean duration of utilisation of these accesses is 107 days for diabetic patients and 98 days for nondiabetic patients. The major complication observed is sepsis (18.36%). Diabetes mellitus which represent a traditional risk factor does not seem to be responsible here, the climatic and hygienic conditions prevailing in this part of the world could be a contributing factor. Nevertheless, we find the utilisation of these catheters a suitable solution during the waiting period because it is an easy operation, of the good quality of the material used and the comfort brought to the patient.     

Report of the Second Equine Leucocyte Antigen Workshop, Squaw valley, California, July 1995

The final assignment of antibody clusters for leucocyte antigens and immunoglobulins, as described in detail in Sections 3 and 4, is summarized in Table 4. Together with other mAbs developed outside of ELAW II (Table 9) this pool of reagents represent a powerful array of tools for the study of equine immunity. The Second Equine Leucocyte Antigen Workshop made considerable advances in pursuing the objectives of establishing the specificities of mAbs and achieving consensus on the nomenclature for equine leucocyte and immunoglobulin molecules. Of equal importance, several productive collaborations were fostered among the participating laboratories and observers. Overall, enormous advances have been made in the past decade since mAbs specific for equine leucocyte antigens and immunoglobulins were first reported. There remains enormous scope and need for further studies of equine leucocyte antigens and immunoglobulins, both for the purposes of comparative immunology and for the good of the horse. In the future novel techniques will be required to develop reagents for specific target antigens such as the orthologues of the CD25 or CD45 isoforms. In studies of equine immunoglobulins the functional role of the IgG isotypes must be better established, reagents for IgE must be developed, and cloning of the immunoglobulin heavy chain genes will be essential if the complexities of the IgG sub-isotypes are to be elucidated. The tasks still facing the currently small group of equine immunologists throughout the world remain formidable, and will only be tackled successfully in a spirit of collaboration.     

Eicosanoid generating capacities of different tissues from the rainbow trout,Oncorhynchus mykiss

The eicosanoid generating potential of the brain, gills, skin, ovary, muscle, eye, liver, spleen, heart, and alimentary canal in the rainbow trout,Oncorhynchus mykiss, was examined. All the organs/tissues examined synthesized the 12-lipoxygenase products, 12-hydroxyeicosatetraenoic acid (12-HETE), and 12-hydroxyeicosapentaenoic acid (12-HEPE), implying the widespread nature of this enzyme in trout. Both prostaglandin E and LTC were also found in variable amounts in the organs, with the greatest amount of PGE found in the gill. Leukotriene (LT) B₄ and LTB₅ were found in supernatants from calcium ionophore-challenged brain, skin, ovary, liver, spleen, and heart, but the lipoxins A₄ and A₅ were only present in brain, ovary, and spleen in relatively small amounts. As lipoxins have previously been shown to be synthesized by macrophages in rainbow trout [Pettittet al., J. Biol. Chem. 266, 8720–8726 (1991)], and related cells (microglial cells) are found in the brain of mammals, the localization of macrophage-like cells in trout brain was investigated immunocytochemically. Monoclonal antibodies specific for trout leucocytes failed to identifity any microglial-like cells in sections of the brain, although microvessels containing immuno-positive reaction products were observed. A number of distinct lipoxygenase products were found in supernatants of ionophore-challenged gill, including 14-hydroxydocosahexaenoic acid, 12-HETE, and 12-HEPE, and a large number of dihydroxy fatty acid derivatives with conjugated triene chromophores. One of these products was tentatively identified as 8(R),15(S)-dihydroxyeicosatetraenoic acid, a dual 12- and 15-lipoxygenase product, but apparently no LTB₄ was generated by this tissue.     

A clinicopathologic analysis of AIDS-related cryptosporidiosis

OBJECTIVE: To characterize the histology of AIDS-associated cryptosporidiosis and identify features that explain the clinical variability. DESIGN: A retrospective analysis of HIV-positive individuals with cryptosporidiosis who underwent endoscopy at the Johns Hopkins Hospital between 1985 and 1996. METHODS: The histologic features (intensity of Cryptosporidium infection, inflammation, mucosal damage, copathogens) of gastrointestinal biopsies from 37 HIV-positive individuals with cryptosporidiosis were systematically graded. These histologic features were correlated with the severity of the diarrheal illness obtained from a patient chart review. RESULTS: Histologic features associated with Cryptosporidium infection include a neutrophilic infiltrate in the stomach, villus blunting in the duodenum, cryptitis and epithelial apoptosis in the colon, and reactive epithelial changes in the stomach and duodenum. The nature and intensity of the inflammatory response varied widely; however, duodenal biopsies from a subset of patients (37%) revealed marked acute inflammation that was associated with concomitant cytomegalovirus infection. Although duodenal infection was common (93% of individuals), infection of other sites was variable (gastric cryptosporidiosis in 40% and colonic cryptosporidiosis in 74%). Widespread infection of the intestinal tract, which included both the large and small intestine, was associated with the most severe diarrheal illness. CONCLUSIONS: Cryptosporidium infection produces histologic evidence of gastrointestinal mucosal injury. The inflammatory response to the infection is variable, and may be modified by copathogens such as cytomegalovirus. The clinical manifestations are influenced, in part, by the anatomic distribution of the infection, with extensive infections involving both small and large intestines producing the most severe illness.     

Evaluation of acute physiology and chronic health evaluation III predictions of hospital mortality in an independent database

OBJECTIVE: To assess the accuracy and validity of Acute Physiology and Chronic Health Evaluation (APACHE) III hospital mortality predictions in an independent sample of U.S. intensive care unit (ICU) admissions. DESIGN: Nonrandomized, observational, cohort study. SETTING: Two hundred eighty-five ICUs in 161 U.S. hospitals, including 65 members of the Council of Teaching Hospitals and 64 nonteaching hospitals. PATIENTS: A consecutive sample of 37,668 ICU admissions during 1993 to 1996; including 25,448 admissions at hospitals with >400 beds and 1,074 admissions at hospitals with <200 beds. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We used demographic, clinical, and physiologic information recorded during ICU day 1 and the APACHE III equation to predict the probability of hospital mortality for each patient. We compared observed and predicted mortality for all admissions and across patient subgroups and assessed predictive accuracy using tests of discrimination and calibration. Aggregate hospital death rate was 12.35% and predicted hospital death rate was 12.27% (p =.541). The model discriminated between survivors and nonsurvivors well (area under receiver operating curve = 0.89). A calibration curve showed that the observed number of hospital deaths was close to the number of deaths predicted by the model, but when tested across deciles of risk, goodness-of-fit (Hosmer-Lemeshow statistic, chi-square = 48.71, 8 degrees of freedom, p< .0001) was not perfect. Observed and predicted hospital mortality rates were not significantly (p < .01) different for 55 (84.6%) of APACHE III's 65 specific ICU admission diagnoses and for 11 (84.6%) of the 13 residual organ system-related categories. The most frequent diagnoses with significant (p < .01) differences between observed and predicted hospital mortality rates included acute myocardial infarction, drug overdose, nonoperative head trauma, and nonoperative multiple trauma. CONCLUSIONS: APACHE III accurately predicted aggregate hospital mortality in an independent sample of U.S. ICU admissions. Further improvements in calibration can be achieved by more precise disease labeling, improved acquisition and weighting of neurologic abnormalities, adjustments that reflect changes in treatment outcomes over time, and a larger national database.