Training of vertical versus horizontal reading in patients with hemianopia - a randomized and controlled study.

HYPOTHESIS: Patients with hemianopic field defects (HFD) might benefit from reading text in vertical orientation if they place the text in the seeing hemifield along the vertical midline. METHODS: We assigned 21 patients with HFD randomly to either vertical or horizontal reading training. They trained reading single lines of texts from a computer screen at home for 2 × 30 min/day, 5 days/week, for 4 weeks. The main outcome variable was reading speed (RS) during reading standardized paragraphs of printed text (IReST) aloud. RS was assessed before training (T1), directly after training (T2) and 4 weeks later (T3). Quality of life (QoL) was assessed by Impact of Visual Impairment (IVI) questionnaire. RESULTS: Vertical training improved RS in the vertical direction significantly. Only patients with right HFD benefited. Horizontal training improved RS in horizontal diection significantly, but much more in patients with left than in those with right HFD. Both effects remained stable at T3. RS during training at the computer improved highly significantly and correlated strongly with RS of printed text (Pearson r= > 0.9). QoL: Vertical training showed a statistically significant improvement in the complete IVI-score, patients with right HFD in the emotional IVI-score. CONCLUSIONS: The improvements of RS were specific for the training. The stable effect indicates that the patients can apply the newly learned strategies to everyday life. The side of the HFD plays an essential role: Left-HFD patients benefitted from horizontal training, right-HFD patients from vertical training. However, the vertical RS did not reach the level of horizontal RS. The study was registered in the German Clinical Trials register (DRKS-ID: DRKS00018843).

Effects of home reading training on reading and quality of life in AMD-a randomized and controlled study.

BACKGROUND: Age-related macular degeneration (AMD) causes reading impairment, reduced quality of life (QoL), and secondary depression. We have shown that support with magnifying aids improved reading speed (RS), emotional and cognitive status, and QoL. The present study investigates whether additional reading training (RT) (after adapting to appropriate visual aids) can further improve vision rehabilitation. METHODS: Patients with dry AMD were randomly assigned to 2 groups. The primary RT group (P-RTG, n = 25) trained with sequentially presented text (RSVP), and the control group (CG, n = 12) performed placebo training (crossword puzzles) and later crossed over to RT, so that altogether 37 participants performed reading training. Patients trained at home on a PC for 6 weeks. RS was assessed during reading printed paragraphs of text aloud. Using a scanning laser ophthalmoscope, we examined fixation stability and preferred retinal locus (PRL) for fixating a cross, as well as PRL and eye movements during reading single words. We assessed emotional status by Montgomery-Åsberg Depression Rating Scale (MADRS), cognitive status by dementia detection test ( DemTect ) and QoL by Impact of Vision Impairment (IVI) profile. Visual acuity and magnification requirement were examined by standard procedures. All variables were measured before and after placebo training, before and after RT, and after 6 weeks without training (follow-up). RESULTS: RS improved significantly in the P-RTG during RT, but not in the CG during placebo training. The effect remained stable at follow-up. Fixation performance and eye movement variables did not change. Emotional status (MADRS) improved in P-RTG during RT and showed a significant difference of the change of scores between the 2 groups. Complete IVI scores improved significantly during RT and remained stable. CONCLUSION: The results indicate that patients with AMD, who already use magnifying aids, benefit from additional RT and that it can contribute in preventing depression and improve QoL. TRIAL REGISTRATION: The study was registered at the German Clinical Trials Register (DRKS00015609).

Eye movement involvement in Parry-Romberg Syndrome: a clinicopathologic case report.

We report the case of a 38-year-old woman who developed a progressive bilateral disease in which the eye motility disorder-diplopia-is the outstanding feature over a period of 12 years. The muscle biopsy of the medial rectus muscle did not show any trace of striated muscle. To the best of our knowledge, this is the first pathological report in an affected extraocular muscle of a patient with Parry-Romberg syndrome (PRS). Previous rare reports of diplopia in PRS have been attributed to enophthalmos, progressive atrophy of the orbit, ocular motor nerve dysfunction, or mechanical restrictions.

Monocyte adhesion to activated aortic endothelium: role of L-selectin and heparan sulfate proteoglycans.

This study examines the role of L-selectin in monocyte adhesion to arterial endothelium, a key pathogenic event of atherosclerosis. Using a nonstatic (rotation) adhesion assay, we observed that monocyte binding to bovine aortic endothelium at 4 degrees C increased four to nine times upon endothelium activation with tumor necrosis factor (TNF)-alpha. mAb-blocking experiments demonstrated that L-selectin mediates a major part (64 +/- 18%) of monocyte attachment. Videomicroscopy experiments performed under flow indicated that monocytes abruptly halted on 8-h TNF-alpha-activated aortic endothelium, approximately 80% of monocyte attachment being mediated by L-selectin. Flow cytometric studies with a L-selectin/IgM heavy chain chimeric protein showed calcium-dependent L-selectin binding to cytokine-activated and, unexpectedly, unactivated aortic cells. Soluble L-selectin binding was completely inhibited by anti-L-selectin mAb or by aortic cell exposure to trypsin. Experiments with cycloheximide, chlorate, or neuraminidase showed that protein synthesis and sulfate groups, but not sialic acid residues, were essential for L-selectin counterreceptor function. Moreover, heparin lyases partially inhibited soluble L-selectin binding to cytokine-activated aortic cells, whereas a stronger inhibition was seen with unstimulated endothelial cells, suggesting that cytokine activation could induce the expression of additional ligand(s) for L-selectin, distinct from heparan sulfate proteoglycans. Under flow, endothelial cell treatment with heparinase inhibited by approximately 80% monocyte attachment to TNF-alpha-activated aortic endothelium, indicating a major role for heparan sulfate proteoglycans in monocyte-endothelial interactions. Thus, L-selectin mediates monocyte attachment to activated aortic endothelium, and heparan sulfate proteoglycans serve as arterial ligands for monocyte L-selectin.

P-selectin glycoprotein ligand 1 is a ligand for L-selectin on neutrophils, monocytes, and CD34+ hematopoietic progenitor cells.

Selectins play a critical role in initiating leukocyte binding to vascular endothelium. In addition, in vitro experiments have shown that neutrophils use L-selectin to roll on adherent neutrophils, suggesting that they express a nonvascular L-selectin ligand. Using a L-selectin/IgM heavy chain (mu) chimeric protein as an immunocytological probe, we show here that L-selectin can bind to neutrophils, monocytes, CD34+ hematopoietic progenitors, and HL-60 and KG-1 myeloid cells. The interaction between L-selectin and leukocytes was protease sensitive and calcium dependent, and abolished by cell treatment with neuraminidase, chlorate, or O-sialoglycoprotein endopeptidase. These results revealed common features between leukocyte L-selectin ligand and the mucin-like P-selectin glycoprotein ligand 1 (PSGL-1), which mediates neutrophil rolling on P- and E-selectin. The possibility that PSGL-1 could be a ligand for L-selectin was further supported by the ability of P-selectin/mu chimera to inhibit L-selectin/mu binding to leukocytes and by the complete inhibition of both selectin interactions with myeloid cells treated with mocarhagin, a cobra venom metalloproteinase that cleaves the amino terminus of PSGL-1 at Tyr-51. Finally, the abrogation of L- and P-selectin binding to myeloid cells treated with a polyclonal antibody, raised against a peptide corresponding to the amino acid residues 42-56 of PSGL-1, indicated that L- and P-selectin interact with a domain located at the amino-terminal end of PSGL-1. The ability of the anti-PSGL-1 mAb PL-1 to inhibit L- and P-selectin binding to KG-1 cells further supported that possibility. Thus, apart from being involved in neutrophil rolling on P- and E-selectin, PSGL-1 also plays a critical role in mediating neutrophil attachment to adherent neutrophils. Interaction between L-selectin and PSGL-1 may be of major importance for increasing leukocyte recruitment at inflammatory sites.

Cleaved L-selectin concentrations in meningeal leukaemia.

Involvement of the central nervous system has important therapeutic implications in acute leukaemia. Because the identification of blast cells in cerebrospinal fluid (CSF) is often difficult, there is a need for sensitive markers of leukaemic infiltration. Since the shed form of L-selectin (sL-selectin) is frequently increased in acute leukaemia (sL-selectin+ leukaemia), we examined whether assay of sL-selectin in CSF could improve our ability to detect such meningeal involvement. CSF sL-selectin was significantly (p < 0.001) higher in 15 patients with sL-selectin+ meningeal leukaemia (median 60 ng/mL, range 34-150) than in 20 patients with acute leukaemia without meningeal involvement (12 ng/mL, 1-39) or 88 control patients (14 ng/mL, 0-37). Serial measurements of sL-selectin in patients with sL-selectin+ leukaemic meningitis showed increased CSF concentrations of the cleaved receptor in 4 patients with therapy-resistant meningeal leukaemia and sustained normal concentrations in 9 patients in remission. Our results suggest that CSF sL-selectin may be a useful marker in the detection of meningeal involvement by blast cells in patients with sL-selectin+ leukaemia.

High levels of the shed form of L-selectin are present in patients with acute leukemia and inhibit blast cell adhesion to activated endothelium.

L-selectin is expressed by most leukocytes and mediates the initial step of adhesion to vascular endothelium. A feature of this adhesion receptor is to be shed from the cell surface. We report here the presence of high levels of the shed form of L-selectin (sL-selectin) in plasma from patients with acute leukemia. We also show that sL-selectin purified from acute leukemia plasma exhibits functional activity. The mean (+/- 1 SD) plasma level of sL-selectin among 100 healthy individuals was 2.1 +/- 0.7 micrograms/mL. This value was increased (> 2 SD above the mean) in 63% of 58 patients with acute lymphoblastic leukemia (ALL) and 59% of 93 patients with acute myelogenous leukemia ([AML] P < .001). Repeated measurements in 24 patients showed normal-range levels in 16 of 16 patients in complete remission and high levels in eight of eight patients with therapy-resistant acute leukemia or leukemia relapse. Furthermore, elevated sL-selectin levels were detected in cerebrospinal fluid of three patients with ALL suffering from a relapse limited to the central nervous system. Epitope mapping with monoclonal antibodies demonstrated that L-selectin shedding from leukemic blasts was accompanied by conformational changes of its epidermal growth factor-like domain. A functional role for sL-selectin purified from leukemic plasma was supported by its ability to completely inhibit L-selectin-dependent adhesion of blast cells to tumor necrosis factor-alpha (TNF-alpha)-activated endothelium in vitro. These results suggest that sL-selectin may have an important role in the regulation of leukemic cell adhesion to endothelium. In addition, monitoring of the sL-selectin level may be useful for evaluating leukemia activity, in particular for the detection of leukemia relapse.

Highly diverse T cell recognition of a single Plasmodium berghei peptide presented by a series of mutant H-2Kd molecules.

We have tested 21 independent CTL clones for recognition of a single peptide derived from the Plasmodium berghei circumsporozoite protein in the context of 13 mutants of the murine MHC class I molecule H-2Kd. In this series of Kd mutants, amino acid residues located on the upper surface of the alpha-helices were individually substituted by alanine. Remarkably, most clones displayed individual recognition patterns on the Kd mutants. We had previously found that this series of CTL clones was likewise highly diverse in terms of both TCR primary structure and peptide fine specificity. Our data thus reinforce the concept that multiple T cell epitopes are available on the surface of a single peptide-MHC class I complex for recognition by specific TCR.

Immunization with synthetic peptides containing a defined malaria epitope induces a highly diverse cytotoxic T lymphocyte response. Evidence that two peptide residues are buried in the MHC molecule.

In the present study, we have explored ways of inducing a CTL response to a previously defined H-2Kd MHC class I restricted epitope in the circumsporozoite (CS) protein of Plasmodium berghei, and studied in detail the fine specificity of the response. We found that the s.c. injection of a variety of synthetic peptides emulsified in Freund's adjuvant efficiently induced a specific CTL response in (BALB/c x C57BL/6)F1 (H-2d x H-2b) mice. In contrast, BALB/c mice responded only marginally, consistent with the possible requirement for a concomitant Th response that would be provided by the C57BL/6 strain. Similar to our previous observations in analyzing CTL clones from sporozoite-immunized mice, the CTL response induced by peptide immunization was in part cross-reactive with an epitope from the Plasmodium yoelii species. The minimal P. berghei CS epitope, the octapeptide PbCS 253-260, was studied in detail by the analysis of a series of variant CS peptides containing single Ala substitutions. The relative antigenic activity for each variant peptide was calculated for 28 different CTL clones. Overall, the response to this P. berghei CTL epitope appeared to be extremely diverse in terms of fine specificity. This was evident among the CTL derived from sporozoite-immunized mice, as well as among those from peptide-immunized animals. The heterogeneity found at the functional level correlates with the highly diverse TCR repertoire that we have found for the same series of CTL clones in a study that is reported separately. The relative competitor activity for each Ala-substituted peptide was also determined in a quantitative functional competition assay. For the residues (Tyr253 and Ile260) within the 8-mer CS peptide, substitution with Ala reduced competitor activity by at least 40-fold, and for two others the reduction was 5- to 10-fold. When the relative antigenic activity for each CTL/peptide combination was normalized to the relative competitor activity of the peptide, a striking pattern emerged. The two residues that most affected competitor activity showed no additional effect on recognition beyond that observed for competition. In marked contrast, Ala substitutions at the other five positions tested varied widely, depending on the CTL/peptide combination. This pattern not only supports a model whereby the Tyr253 and Ile260 residues anchor the peptide to the Kd molecule, but also implies that they are virtually inaccessible to the TCR.

CD8+ cytolytic T cell clones derived against the Plasmodium yoelii circumsporozoite protein protect against malaria.

Immunization of BALB/c mice with radiation-attenuated Plasmodium yoelii sporozoites induces cytotoxic T lymphocytes (CTL) specific for an epitope located within the amino acid sequence 277-288 of the P. yoelii circumsporozoite (CS) protein. Several CD8+ CTL clones were derived from the spleen cells of sporozoite-immunized mice, all displaying an apparently identical epitope specificity. All the clones induced high levels of cytolysis in vitro upon exposure to peptide-incubated MHC-compatible target cells. The adoptive transfer of two of these clones conferred complete protection against sporozoite challenge to naive mice. This protection is species and stage specific. Using P. yoelii specific ribosomal RNA probes to monitor the in vivo effects of the CTL clones, we found that their target was the intrahepatocytic stage of the parasite. The protective clones completely inhibited the development of the liver stages of P. yoelii. Some CTL clones were only partially inhibitory in vivo, while others failed completely to alter liver stage development and to confer any detectable degree of protection. The elucidation of the effector mechanism of this CTL mediated protection against rodent malaria should facilitate the design of an effective malaria vaccine. From a broader perspective this model may provide further insight into the mechanism(s) of CTL mediated killing of intracellular non-viral pathogens in general.

Isolation and characterization of protective cytolytic T cells in a rodent malaria model system.

Protective immunity against malaria is induced by immunization with irradiation-attenuated sporozoites. Here we report the isolation of cytolytic T-cell (CTL) clones from BALB/c (H-2d) mice immunized with either Plasmodium berghei or Plasmodium yoelii sporozoites. The epitopes recognized by these CTL can be mimicked by synthetic peptides corresponding to a homologous region in the CS proteins of both rodent malaria species. Both peptides are recognized by the CTL in the context of the same MHC class I molecule, H-2 Kd. In vivo adoptive transfer of the CTL clones into non-immune syngeneic mice protected them from a lethal challenge of infectious sporozoites.