Selective laser trabeculoplasty in the treatment of pseudoexfoliation glaucoma in patients allergic to all anti-glaucoma drops

Secondary chronic open-angle glaucoma associated with pseudoexfoliation (PEX) syndrome accounts for approximately 25% of all glaucomas and represents the most common identifiable cause of glaucoma overall. Selective laser trabeculoplasty (SLT) is effective in reducing intraocular pressure (IOP) in glaucomatous patients and has the advantage of preserving surrounding structures. We report here SLT treatment of a 82 year old female with a secondary developed open-angle pseudoexfoliation glaucoma allergic to all anti glaucoma eye drops especially those which contain bensalconium chloridum as preservative. Since patient was allergic also to methyl-cellulose, we performed SLT with water as a mediator. Patient had PEX syndrome for 10 years, immature cataracts on both eyes, and best corrected visual acuity (BCVA) 0.7 on the right and 0.2 on the left eye. We have monitored intraocular pressure (IOP), the changes in the visual field and optic nerve. Preoperative IOP was 28 mmHg on the right and 30 mmHg on the left eye. The follow up period was 24 months with time points for measured parameters every 3 months. After 18 months IOP remained in the normal values (average 17 mmHg) on the right eye, but on the left eye it increased up to 28 mmHg. SLT re-treatment was carried out on the left eye and the IOP stabilized again on the values between 16-18mmHg. There were no significant change in the visual field and optic nerve configuration before and after SLT (C/D value for right eye: 0.3-0.4; C/D left eye: 0.5). Based on this case report, SLT seems to be very effective treatment for maintaining regular IOP in patient with PEX who is allergic to all types of medications.     

Hip fractures in elderly--ten years analysis

Geriatric hip fractures (GHP) are the major problem in the geriatric traumatology and it is estimated that treatment of GHF will spend a large amount of health care resources. The aim of this retrospective study was to compare differences in incidence of operatively treated patients with GHF, type of treatment depending of the type of fracture, early postoperative mortality, length of stay and costs of used implants within a 10 years period. Surgically treated 2478 patients, older than 65 years with hip fractures were included in the study. Patients were grouped according to the type of fracture (femoral neck fracture or intertrochanteric femoral fracture) and used implant. Results showed increasing trend in GHF in our County in the last 10 years. There was a shifting trend in used implants, and new surgical techniques were used more commonly in the last few years. In observed period there were no significant changes in revision surgery and length of hospital stay. The mortality decreased, especially in males, but generally it was not in correlation with used implant. At the 10-years period increase in patients with GHF of 179% was followed with 4 time higher increase in implant prices. Present reimbursement in health care system does not calculate the difference of implant costs in hospital expenses, therefore proper usage of modern implants and careful planning in the treatment of GHF is necessary.     

Perfluoroalkylated derivatives of 6-deoxy-6-ethylamino-d-galactose, 1-deoxy-1-methylamino-d-glucitol, and 1-amino-1-deoxy-d-glucitol: syntheses, hemocompatibility, and effect on perfluorocarbon emulsion

N-Polyfluoroalkyl derivatives of 6-deoxy-6-ethylamino-1,2;3,4-di-O-isopropylidene-α-d-galactopyranose (8-10), 1-deoxy-1-methylamino-d-glucitol (13-15), and 1-amino-1-deoxy-d-glucitol (16-18), all possessing perfluoroalkyl segment, were prepared using nucleophilic epoxide ring opening of 2-[(perfluoroalkyl)methyl]oxiranes 1-3. Co-emulsifying properties and hemolytic activity of the new perfluoroalkylated amphiphiles were tested. Both types of the polyol derivatives 8-10 and 13-18 generally displayed good to excellent co-emulsifying properties on testing on perfluorodecalin/Pluronic F-68 microemulsions. Mono-perfluoroalkylated compounds 8-10 and 13-15 displayed high hemolysis, whereas acyclic bis-perfluoroalkylated compounds 16-18 were non-hemolytic even for short perfluorobutyl segment (16). The properties were generally improving with increasing perfluoroalkyl chain length.     

Subunit Symmetry at the Extracellular Domain-Transmembrane Domain Interface in Acetylcholine Receptor Channel Gating

Transmitter molecules bind to synaptic acetylcholine receptor channels (AChRs) to promote a global channel-opening conformational change. Although the detailed mechanism that links ligand binding and channel gating is uncertain, the energy changes caused by mutations appear to be more symmetrical between subunits in the transmembrane domain compared with the extracellular domain. The only covalent connection between these domains is the pre-M1 linker, a stretch of five amino acids that joins strand β10 with the M1 helix. In each subunit, this linker has a central Arg (Arg^3′), which only in the non-α-subunits is flanked by positively charged residues. Previous studies showed that mutations of Arg^3′ in the α-subunit alter the gating equilibrium constant and reduce channel expression. We recorded single-channel currents and estimated the gating rate and equilibrium constants of adult mouse AChRs with mutations at the pre-M1 linker and the nearby residue Glu⁴⁵ in non-α-subunits. In all subunits, mutations of Arg^3′ had similar effects as in the α-subunit. In the ϵ-subunit, mutations of the flanking residues and Glu⁴⁵ had only small effects, and there was no energy coupling between ϵGlu⁴⁵ and ϵArg^3′. The non-α-subunit Arg^3′ residues had Φ-values that were similar to those for the α-subunit. The results suggest that there is a general symmetry between the AChR subunits during gating isomerization in this linker and that the central Arg is involved in expression more so than gating. The energy transfer through the AChR during gating appears to mainly involve Glu⁴⁵, but only in the α-subunits.     

Physiological role of the alpha1- and alpha2-isoforms of the Na+-K+-ATPase and biological significance of their cardiac glycoside binding site

An interesting feature of Na+-K+-ATPase is that it contains four isoforms of the catalytic alpha-subunit, each with a tissue-specific distribution. Our laboratory has used gene targeting to define the functional role of the alpha1- and alpha2-isoforms. While knockout mice demonstrated the importance of the alpha1- and alpha2-isoforms for survival, the knockin mice, in which each isoform can be individually inhibited by ouabain and its function determined, demonstrated that both isoforms are regulators of cardiac muscle contractility. Another intriguing aspect of the Na+-K+-ATPase is that it contains a binding site for cardiac glycosides, such as digoxin. Conservation of this site suggests that it may have an in vivo role and that a natural ligand must exist to interact with this site. In fact, cardiac glycoside-like compounds have been observed in mammals. Our recent study demonstrates that the cardiac glycoside binding site of the Na+-K+-ATPase plays a role in the regulation of blood pressure and that it mediates both ouabain-induced and ACTH-induced hypertension in mice. Whereas chronic administration of ouabain or ACTH caused hypertension in wild-type mice, it had no effect on blood pressure in mice with a ouabain-resistant alpha2-isoform of Na+-K+-ATPase. Interestingly, animals with the ouabain-sensitive alpha1-isoform and a ouabain-resistant alpha2-isoform develop ACTH-induced hypertension to a greater extent than wild-type animals. Taken together, these results demonstrate that the cardiac glycoside binding of the Na+-K+-ATPase has a physiological role and suggests a function for a naturally occurring ligand that is stimulated by administration of ACTH.     

Comparison of bacterial flora and enzymatic activity in faeces of infants and calves

Sixty-four breast-fed infants and 23 calves were investigated for bacteria and enzymatic activity in their faecal samples. The bacteria were measured using cultivation and fluorescence in situ hybridization. Enzymatic activity was also examined. Forty-seven (64%) infants and all the calves had high numbers of bifidobacteria (usually >9 log CFU g-1) in their faeces, but 17 infants (36%) did not have a detectable amount of the bacteria. Most of the bifidobacteria-negative infants had significant quantities of clostridia in their faecal flora. While the infants did not have significantly higher counts of bifidobacteria, the samples from calves contained significantly (P<0.05) more coliform bacteria and lactobacilli. There were also significant differences in their enzymatic activities. Bifidobacteria-positive samples had a greater alpha-glucosidase activity, while bifidobacteria-negative samples had a lower activity of alpha-galactosidase, and calf samples had the highest beta-glucuronidase activity. A significant increase in bifidobacteria in calf faeces between days 3 and 7 was accompanied by a decrease in Escherichia coli. Our results show that the faecal flora of calves is similar to that of infants with regard to the occurrence of bifidobacteria as a dominant bacterial group.     

Prevalence of vancomycin-resistant enterococci in hospitalized patients and those living in the community in the Czech Republic

Between July 1, 2002 and December 31, 2003, rectal swabs from both hospitalized patients and community subjects in the Czech Republic were taken to ascertain the prevalence of vancomycin-resistant enterococci (VRE). The swabs were used for isolating and identifying enterococci and their susceptibility to antibiotics. Vancomycin resistance phenotypes were verified by PCR detection of vanA, vanB, vanC1 and vanC2 genes. A molecular biology analysis was performed in Enterococcus faecium VanA strains. During the observed period, 2691 rectal swabs from the hospitalized patients and 6529 rectal swabs from the subjects in community setting were examined. In total, 31 VRE of hospital origin and 13 community-population strains were isolated. The prevalence of VRE in the gastrointestinal tract was 1.9% in the hospitalized patients and 0.4% in the community subjects. The prevailing strains were Enterococcus faecium VanA (61.3%) in the VRE of hospital origin and Enterococcus gallinarum VanC (46.2%) in the community VRE. Mutual comparison between the hospital and community Enterococcus faecium VanA strains showed no similarity.     

Sources and pathways of spread of vancomycin-resistant enterococci in hemato-oncological patients

The presented study aims at analyzing an increasing prevalence of vancomycin-resistant enterococci (VRE) isolated from various kinds of clinical material obtained from patients in the Department of Hemato-oncology (DHO), University Hospital in Olomouc, Czech Republic. Between January 1 and March 31, 2005, enterococci were isolated by standard microbiological procedures using both clinical material obtained from hospitalized patients and samples from the department environment. Resistance to vancomycin and teicoplanin was determined by a standardized microdilution method. Phenotype determination of resistance to vancomycin was verified by PCR detection of vanA and vanB genes. In VanA Enterococcus faecium, macrorestriction analysis was performed by pulsed-field gel electrophoresis. During the monitored period, a total of 128 Enterococcus sp. strains were isolated, of which 38 (30 %) isolates from 22 different patients were determined as VRE. Dominating were Enterococcus faecium VanA (63 %) and Enterococcus casseliflavus VanC (16 %) strains. At the same time, one Enterococcus faecium VanA strain was acquired from a bed-side table used by a patient in whom a similar strain had been isolated repeatedly from various clinical materials including a rectal swab taken in 2004. Based on the macrorestriction analysis of genome DNA in 24 vancomycin-resistant Enterococcus faecium VanA strains isolated from the patients' clinical material, one strain from the bed-side table surface and one strain isolated from stools in 2004, 8 unique restriction profiles with similarity ranging from 90 % to 100 % were identified, which could be classified into 3 clonal types. Thus, we can assume not only the endogenous origin of the VRE in hemato-oncological patients and their potential selection caused by therapy with broad-spectrum antibiotics but also the ability of the strains to survive in a hospital setting and, subsequently, to be spread clonally by various vectors.     

Evolution of a carbohydrate binding module into a protein-specific binder

A carbohydrate binding module, CBM4-2, derived from the xylanase (Xyn 10A) of Rhodothermus marinus has been used as a scaffold for molecular diversification. Its binding specificity has been evolved to recognise a quite different target, a human monoclonal IgG4. In order to understand the basis for this drastic change in specificity we have further investigated the target recognition of the IgG4-specific CBMs. Firstly, we defined that the structure target recognised by the selected CBM-variants was the protein and not the carbohydrates attached to the glycoprotein. We also identified key residues involved in the new specificity and/or responsible for the swap in specificity, from xylan to human IgG4. Specific changes present in all these CBMs included mutations not introduced in the design of the library from which the specific clones were selected. Reversion of such mutations led to a complete loss of binding to the target molecule, suggesting that they are critical for the recognition of human IgG4. Together with the mutations introduced at will, they had transformed the CBM scaffold into a protein binder. We have thus shown that the scaffold of CBM4-2 is able to harbour molecular recognition for either carbohydrate or protein structures.