Calibration of modified Liulin detector for cosmic radiation measurements on-board aircraft.

The annual effective doses of aircrew members often exceed the limit of 1 mSv for the public due to the increased level of cosmic radiation at the flight altitudes, and thus, it is recommended to monitor them. Aircrew dosimetry is usually performed using special computer programs mostly based on results of Monte Carlo simulations. Contemporary, detectors are used mostly for validation of these computer codes, verification of effective dose calculations and for research purposes. One of such detectors is active silicon semiconductor deposited energy spectrometer Liulin. Output quantities of measurement with the Liulin detector are the absorbed dose in silicon D and the ambient dose equivalent H*(10); to determine it, two calibrations are necessary. The purpose of this work was to develop a calibration methodology that can be used to convert signal from the detector to D independently on calibration performed at Heavy Ion Medical Accelerator facility in Chiba, Japan.

Microtron MT 25 as a source of neutrons.

The objective was to describe Microtron MT25 as a source of neutrons generated by bremsstrahlung induced photonuclear reactions in U and Pb targets. Bremsstrahlung photons were produced by electrons accelerated at energy 21.6 MeV. Spectral fluence of the generated neutrons was calculated with MCNPX code and then experimentally determined at two positions by means of a Bonner spheres spectrometer in which the detector of thermal neutrons was replaced by activation Mn tablets or track detectors CR-39 with a (10)B radiator. The measured neutron spectral fluence and the calculated anisotropy served for the estimation of neutron yield from the targets and for the determination of ambient dose equivalent rate at the place of measurement. Microtron MT25 is intended as one of the sources for testing neutron sensitive devices which will be sent into the space.

[Deep perforating trabeculectomy--results after up to six years follow-up]. / Hluboká perforujíci trabekulektomie--az sestileté výsledky.

AIM: The aim of this retrospective study was to establish intraocular pressure (IOP) values in patients after deep perforating trabeculectomy (TE) in time periods after the surgery (one month, 3 months, 1 year, 3 years, and 6 years). Furthermore, the pharmacotherapy after TE and complications after TE, especially consecutive cataract surgeries, were followed-up. MATERIAL AND METHODS: Altogether 110 patients were included into the study, which underwent TE in the years 2003 - 2008 at the Department of Ophthalmology, Kyjov Hospital, Czech republic. The TE procedure was performed in the standard manner with the base of the conjunctival flap located at the limbus. The non-parametric Wilcoxon pair test was used for the statistical evaluation. RESULTS: In all time periods after the surgeries, statistically significant decrease of the IOP comparing to the preoperative values occurred (test significance p < 0.0001 for all comparisons). The pharmacotherapy after the TE was reduced significantly: after 6 years, there were 27% of patients without any therapy, 39% of patients used the neuroprotective monotherapy only, 32% used combined therapy with two medications, and two patients only were treated by combined therapy with three medications. In two patients in which the target IOP was not reached, another TE was performed and the target IOP was achieved. CONCLUSIONS: TE is safe and effective method in the glaucoma therapy. After 6 years, two thirds of patients are without any therapy, or with neuroprotective monotherapy respectively.

[Our experience with sub-Tenon's anesthesia in ophthalmic surgery]. / Nase zkusenosti s ocní chirurgií v sub-Tenonské anestezii.

The goal of the paper is to refer to and to inform about our own experiences with the Sub-Tenon's anesthesia in the surgery of the anterior as well as posterior segment of the eye. In cataract surgery it is equally efficient as the retrobulbar, peribulbar or topic anesthesia, and it is safer because no sharp needle is used. We operate on the posterior segment in sub-Tenon's anesthesia in patients with contraindicated general anesthesia because of their advanced age, decompensated diabetes mellitus or hypertension, in whom the pars plana vitrectomy is the only possibility to improve the patients' vision. Using the sub-Tenon's anesthesia, about 13.000 cataract surgeries and 127 pars plana vitrectomies without complications were performed. The simple pars plana vitrectomy may be realized at the outpatient basis as well.

[Malignant lymphoma of the orbit]. / Maligní lymfom orbity.

The authors describe a non-Hodgkin malignant large-cell B lymphoma with ample lymphocytes in a female patient with foci in the left breast and right orbit, with suspect skin foci and enlarged nodes in the mediastinum as revealed by computed tomography. In the differential diagnosis the authors reflected according to the course of the disease in addition to malignant lymphoma also on orbitocellulitis or a pseudotumour of the orbit. The remarkable feature is that the patient had already treatment on account of a multiple myeloma. The authors emphasize comprehensive treatment of the patient and the necessity of consultations with specialist of other medical disciplines associated with this disease. After radiotherapy total regression of the orbital finding occurred in the patient.

Toward an optimal oligosaccharide ligand for rat natural killer cell activation receptor NKR-P1.

Aminosugars have a good affinity for the NKR-P1A protein, the major activating receptor at the surface of rat natural killer cells. We have systematically investigated the structural requirements of the recombinant soluble dimeric form of the receptor for its optimal carbohydrate ligands. While N-acetylD-mannosamine was the best neutral monosaccharide ligand, its participation in the context of an extended oligosaccharide sequence was equally important. The IC(50) value for the GalNAcbeta1 --> ManNAc disaccharide was nearly 10(-10) M with a further possible increase depending on the type of the glycosidic linkage and the aglycon nature. From the point of view of its availability, stability, and affinity for the receptor and a potential in vivo use, these studies are pivotal for the design of an oligosaccharide or glycomimetics suitable for further clustering into the multivalent glycodendrimers.

Synthesis of chitooligomer-based glycoconjugates and their binding to the rat natural killer cell activation receptor NKR-P1.

NKR-P1 protein is an important activating receptor at the surface of the rat natural killer cells. GlcNAc and chitooligomers were identified as strong activation ligands in vitro and in vivo. Their clustering brings about increase of their affinity to the NKR-P1 by 3-6 orders. Here we describe novel methodology for preparation of neoglycoproteins based on BSA carrying the chitooligomers (n = 2-5). Further on we developed novel methodology of the coupling of glycosylamines via aromatic-SCN activated linker both to protein or synthetic cores. Inhibition studies of chitooligomer glycoconjugates with the NKR-P1 receptor show that our neoglycoproteins are very strong ligands with high binding affinity (-log IC(50) = 13-15). In analogy with our previous observations with GlcNAc clustered on protein or PAMAM backbones the synthetic chitooligomer clusters should provide considerably better ligands in the in vivo antitumor treatment.