Pterygium and beta irradiation

The results of the combined use of Beta Irradiation, topical Thio-Tepa and dexamethasone in the post-operative treatment of pterygium in 169 patients (213 eyes) are reported. The recurrence rate has been evaluated statistically only in eyes with true pterygia, and for this purpose the material has been divided into 3 groups: group 1 includes all the bilateral cases who either had both eyes treated with Beta therapy or not, group 2 includes all the unilateral cases, and group 3 is made up of the total number of eyes operated. In the group comprising the bilateral cases, the recurrence rate was 2/60 in the eyes treated with Beta rays and 4/18 in the non-treated ones (P less than 0.10). In the group comprising the unilateral cases, the recurrence rate was 8/73 in the Beta rays treated eyes and 18/41 in the non-treated ones (P less than 0.025). When the total number of eyes was considered, the recurrence rate was 10/135 in the eyes treated with Beta rays and 22/61 in the non-treated ones (P less than 0.05). The difference in the recurrence rate between the eyes submitted to Beta therapy and those not submitted is considered statistically significant.     

Changes in autoimmune markers of the anti-cardiolipin syndrome on days of extreme geomamagnetic activity

The possible relation between various biological or medical phenomena and changes in environmental physical activity, such as Solar, Geomagnetic Activity (GMA); Cosmic Ray; Proton, and other particle flux, have been reported. These phenomena seem to be reflected, among others, in the immune system, resulting in changes in immunoglobulin (Ig) levels or outbursts of epidemics. AIM: to examine a possible association of GMA with another aspect of the immune system--autoimmunity. Fluctuations of levels of anticardiolipin (IgG; IgM, IgA subtypes) and lupus anticoagulant (Kaulin clotting time and Dilute Russell's viper venom time) autoantibodies, serving as anticardiolipin syndrome (ACLS) markers, were monitored during days of severe GMA storms and compared with those of lowest/quiet GMA days. Cosmophysical data were obtained from the NOAA National Space Service Center and the National Geophysical Data Center, USA. RESULTS: A significant rise in the levels of anti beta2Gp1-IgA (p = 0.0001); and KCT (p = 0.019) was observed on days of the GMA storms. CONCLUSION: On days of major GMA storms, significant changes in the autoimmune marker levels of ACLS were observed compared with quiet days. An involvement of those changes in clinical events related to GMA storms is possible.     

Epigenetic ontogeny of the Igk locus during B cell development

To become accessible for rearrangement, the immunoglobulin kappa locus must undergo a series of epigenetic changes. This begins in pro-B cells with the relocation of both immunoglobulin kappa alleles from the periphery to the center of the nucleus. In pre-B cells, one allele became preferentially packaged into an active chromatin structure characterized by histone acetylation and methylation of histone H3 lysine 4, while the other allele was recruited to heterochromatin, where it was associated with heterochromatin protein-gamma and Ikaros. These events in cis made only one allele accessible to trans-acting factors, such as RelB, which mediated DNA demethylation, to facilitate rearrangement. These results suggest that early B lymphoid epigenetic changes generate differential structures that serve as the basis for allelic exclusion.     

Large-scale preparation of human anti-third-party veto cytotoxic T lymphocytes depleted of graft-versus-host reactivity: a new source for graft facilitating cells in bone marrow transplantation

Induction of donor type chimerism in mildly prepared hosts without graft-versus-host disease (GvHD) is a most desirable goal in bone morrow transplantation. We have recently demonstrated in a mouse model that donor veto cytotoxic T lymphocytes (CTLs) can facilitate the induction of donor type chimerism in sublethally irradiated recipients without causing GvHD if they are effectively depleted of alloreactivity against host cells by means of stimulation against a third party. We extend this approach to human cells, by preparing CTLs in two major steps: primary culture in the absence of interleukin 2, leading to death by neglect of antihost clones, and addition of interleukin 2 and subsequent dilution of antihost clones as a consequence of the expansion of the anti-third-party clones. CTLs prepared in this way specifically suppress host cytotoxic T cells directed against antigens of the donor, but not against fourth-party antigens, as demonstrated in a standard (51)Cr release assay. We conclude that human anti-third-party CTLs afford a new source of veto cells that are depleted of potential graft-versus-host-reactive clones. The cells generated by this approach could potentially be used to facilitate engraftment of allogeneic hematopoietic stem cells.     

Inflammatory reaction in acute retinal artery occlusion: cytokine levels in aqueous humor and serum

PURPOSE: To investigate the role of inflammation in acute retinal artery occlusion (RAO). METHODS: Levels of interleukin (IL)-6, IL-8, and tumor necrosis factor alpha (TNF-alpha) were measured in serum (n = 14) and aqueous humor (AqH) (n = 8) samples from patients with RAO. Findings were compared with 24 age- and disease-matched patients, 10 healthy subjects (serum), and 16 patients undergoing cataract surgery (AqH). RESULTS: Patients who arrived early (within 4-6 hours of occlusion) had higher serum IL-8 and IL-6 levels than controls; the IL-6 level in the AqH was lower than that of controls, while the IL-8 level was higher. In seven patients for whom both serum and AqH samples were available, serum IL-6 levels were higher than their corresponding AqH levels in most patients arriving within 10 hours of occlusion, and AqH IL-8 levels were higher than the corresponding serum levels in all but one. TNF-alpha levels were consistently higher in the serum than in the AqH at all time points. CONCLUSIONS: Serum IL-8 and IL-6 and AqH IL-8 are elevated immediately following acute RAO. The early local suppression of IL-6 may be related to ocular immune mechanisms.     

Subject index

Purpose: To investigate the role of inflammation in acute retinal artery occlusion (RAO). Methods: Levels of interleukin (IL)-6, IL-8, and tumor necrosis factor alpha (TNF-α) were measured in serum (n = 14) and aqueous humor (AqH) (n = 8) samples from patients with RAO. Findings were compared with 24 age- and disease-matched patients, 10 healthy subjects (serum), and 16 patients undergoing cataract surgery (AqH). Results: Patients who arrived early (within 4–6 hours of occlusion) had higher serum IL-8 and IL-6 levels than controls; the IL-6 level in the AqH was lower than that of controls, while the IL-8 level was higher. In seven patients for whom both serum and AqH samples were available, serum IL-6 levels were higher than their corresponding AqH levels in most patients arriving within 10 hours of occlusion, and AqH IL-8 levels were higher than the corresponding serum levels in all but one. TNF-α levels were consistently higher in the serum than in the AqH at all time points. Conclusions: Serum IL-8 and IL-6 and AqH IL-8 are elevated immediately following acute RAO. The early local suppression of IL-6 may be related to ocular immune mechanisms.     

Epigenetic mechanisms that regulate antigen receptor gene expression

Functional immunoglobulin and T-cell receptor genes are generated from germline V, D and J gene segments by a series of site-specific recombination events. This process is regulated by the availability of recombination machinery and by the ordered accessibility of appropriate target gene segments. Recent studies highlight the importance of chromatin remodelling and locus positioning for controlling antigen receptor gene expression and recombination.