Modelling the bioelectric behaviour of halo pin-patient structures during magnetic resonance imaging

Bioelectric compatibility of electrically conductive halo fixation devices and magnetic resonance (MR) imaging has been largely based on resulting image quality. Previous studies have focused primarily on improving image quality and, although the electrical characteristics of the system during imaging may have been noted, they have not been studied in depth. Utilizing both a theoretical and experimental approximation, this study focuses on the bioelectric characteristics of the pin-patient structures typically enountered in clinical halo fixation systems. Results indicate that the halo pin-patient system can be modelled using a resistor-inductor-capacitor circuit and that simple attempts at improving compatibility through increasing interface resistance by the use of insulated pins may not be an effective approach to improving halo instrumentation compatibility with new, stronger magnetic and higher-frequency resonance imaging systems.     

Alkaline fuel cell: A test plant,measurements and analysis of the results

An experimental study of an alkaline fuel cell test plant with a 0.5 kW fuel cell module is presented in this paper. The characteristics of the fuel cell module are measured in different steady state load conditions and with different electrolyte temperatures. The results are analysed by calculating the different efficiencies of the module.     

Incidence and prevalence of different uveitis entities in Finland

A prospective, open, multicentre study was performed to investigate the efficacy and safety of long-term treatment with cyclosporin in adults with severe atopic dermatitis. Subjects were treated for a maximum of 48 weeks. For the first 8 weeks, cyclosporin was administered at 2.5 mg/kg per day. The dose was then adjusted according to response. Disease activity was monitored using the six-area, six-sign score and the proportion of skin involved. Pruritus and sleep disturbance were assessed using four-point scales. Response was further evaluated on a five-point scale. Adverse events, blood pressure and serum biochemistry were monitored. Tolerability was assessed on a five-point scale. One hundred subjects were enrolled and 65 completed 48 weeks of treatment. Withdrawals occurred due to remission (three), inadequate response (seven), protocol violations (11) and adverse events (14, of which seven were probably treatment related). Cyclosporin produced rapid and highly significant improvements in all indices of disease activity. Sixty-five subjects considered that they had shown a considerable improvement or complete clearance of disease. Most patients relapsed after cessation of treatment, but neither signs nor symptoms had returned to baseline severity 8 weeks later. Blood pressure and serum creatinine levels increased slightly, and in one subject renal impairment was a major factor contributing to withdrawal of the drug. Overall, 85 subjects rated the tolerability of cyclosporin as good or very good. The results indicate that cyclosporin has a place in the long-term treatment of severe atopic dermatitis provided that appropriate patients are selected and careful monitoring is performed.     

Molecular characterization of a novel short-chain dehydrogenase/reductase that reduces all-trans-retinal

The reduction of all-trans-retinal in photoreceptor outer segments is the first step in the regeneration of bleached visual pigments. We report here the cloning of a dehydrogenase, retSDR1, that belongs to the short-chain dehydrogenase/reductase superfamily and localizes predominantly in cone photoreceptors. retSDR1 expressed in insect cells displayed substrate specificities of the photoreceptor all-trans-retinol dehydrogenase. Homology modeling of retSDR1 using the carbonyl reductase structure as a scaffold predicted a classical Rossmann fold for the nucleotide binding, and an N-terminal extension that could facilitate binding of the enzyme to the cell membranes. The presence of retSDR1 in a subset of inner retinal neurons and in other tissues suggests that the enzyme may also be involved in retinol metabolism outside of photoreceptors.     

Detection and effects of helicobacters in healthy dogs and dogs with signs of gastritis

OBJECTIVES: To determine prevalence, colonization density, and distribution of helicobacters and gastric histologic findings in healthy dogs and dogs with signs of gastritis; to evaluate association of colonization density and gastric inflammation; and to compare the number of Helicobacter spp with degree of inflammation. DESIGN: Cross-sectional prevalence survey. ANIMALS: 25 healthy dogs and 21 dogs with signs of gastritis. PROCEDURE: During endoscopy, gastric mucosal biopsy specimens were obtained from healthy and affected client-owned dogs. Histologic and cytologic evaluation and results of a urease test were used for detecting helicobacters, which were identified definitively by use of transmission electron microscopy and bacterial culture. RESULTS: Helicobacters were detected in all 25 healthy and 20 of 21 affected dogs. Cytologic examination was a more sensitive method than histologic examination or the urease test. Helicobacters were found least frequently and in fewest number in the antrum in both groups of dogs. Gastric inflammation was evident in both groups of dogs and did not differ significantly between groups. A significant association was not detected between colonization density or the number of Helicobacter spp and degree of gastric inflammation. In both groups, H bizzozeronii, H felis, and H salomonis were cultured. CLINICAL IMPLICATIONS: Histologically verified chronic gastritis is common in dogs with signs of gastritis as well as in healthy dogs. Colonization density of helicobacters was not associated with degree of gastric inflammation in the dogs of our study. It remains to be determined whether certain strains of Helicobacter spp can induce gastritis in dogs.     

Cellular retinaldehyde-binding protein ligand interactions. Gln-210 and Lys-221 are in the retinoid binding pocket

Cellular retinaldehyde-binding protein (CRALBP) carries 11-cis-retinal and/or 11-cis-retinol as endogenous ligands in the retinal pigment epithelium (RPE) and Müller cells of the retina and has been linked with autosomal recessive retinitis pigmentosa. Ligand interactions determine the physiological role of CRALBP in the RPE where the protein is thought to function as a substrate carrier for 11-cis-retinol dehydrogenase in the synthesis of 11-cis-retinal for visual pigment regeneration. However, CRALBP is also present in optic nerve and brain where its natural ligand and function are not yet known. We have characterized the interactions of retinoids with native bovine CRALBP, human recombinant CRALBP (rCRALBP) and five mutant rCRALBPs. Efforts to trap and/or identify a Schiff base in the dark, under a variety of reducing, denaturing, and pH conditions were unsuccessful, suggesting the lack of covalent interactions between CRALBP and retinoid. Buried and solvent-exposed lysine residues were identified in bovine CRALBP by reductive methylation of the holoprotein followed by denaturation and reaction with [3H]acetic anhydride. Radioactive lysine residues were identified by Edman degradation and electrospray mass spectrometry following proteolysis and purification of modified peptides. Human rCRALBP mutants K152A, K221A, and K294A were prepared to investigate possible retinoid interactions with buried or partially buried lysines. Two other rCRALBP mutants, I162V and Q210R, were also prepared to identify substitutions altering the retinoid binding properties of a random mutant. The structures of all the mutants were verified by amino acid and mass spectral analyses and retinoid binding properties evaluated by UV-visible and fluorescence spectroscopy. All of the mutants bound 11-cis-retinal essentially like the wild type protein, indicating that the proteins were not grossly misfolded. Three of the mutants bound 9-cis-retinal like the wild type protein; however, Q210R and K221A bound less than stoichiometric amounts of the 9-cis-isomer and exhibited lower affinity for this retinoid relative to wild type rCRALBP. Residues Gln-210 and Lys-221 are located within a region of CRALBP exhibiting sequence homology with the ligand binding cavity of yeast phosphatidylinositol-transfer protein. The data implicate Gln-210 and Lys-221 as components of the CRALBP retinoid binding cavity and are discussed in the context of ligand interactions in structurally or functionally related proteins with known crystallographic structures.     

Pre- and postoperative factors associated with return to work following surgery for lumbar spinal stenosis

Low back disorders are an increasingly common and costly health problem in Western countries. It has been recommended that the return to work of patients should be the most important outcome measure of medical care. The aim of this study was to compare women's and men's working capacity after lumbar spinal stenosis (LSS) operations and to identify the factors related to it. The subjects of this study were 185 women (mean age 54 years, mean follow-up time 4.2 years) and 254 men (mean age 52 years, mean follow-up time 4.3 years). After the operation, 37% of the women and 41% of the men returned to work. None of the patients who had retired before the operation returned to work afterward. The variables that predicted postoperative ability to work for women were: being fit to work at the time of operation, age < 50 years at the time of operation, and duration of LSS symptoms < 2 years. For men, these variables were: being fit to work at the time of operation, age < 50 years at the time of operation, no prior surgery, and the extent of the surgical procedure equal to or less than 1 laminectomy. Women's and men's working capacity do not differ after LSS operation. If the aim is to maximize working capacity, then, when an LSS operation is indicated, it should be performed without delay. In LSS patients who are > 50 years old and on sick leave, it is unrealistic to expect that they will return to work. Therefore, after such an extensive surgical procedure, re-education of patients for lighter jobs could improve the chances of these patients returning to work.     

Role of mesenchymal collagenase in the loosening of total hip prosthesis

Fibroblast-type interstitial collagenase (E.C. 3.4.24.7) was associated with loosening of total hip prostheses in eight patients: there were four cemented stems and one cementless stem with the common type of loosening and two cemented stems and one cementless acetabular component with aggressive granulomatous lesions. The authors used a specific, well-characterized, heterologous, affinity-purified, polyclonal rabbit anti-human fibroblast collagenase antiserum applied in avidin-biotin-peroxidase-complex (ABC) staining. In the aggressive granulomatous type of loosening, collagenase was found in most of the fibroblast- and macrophagelike cells, including multinuclear giant cells and epithelioid cells in periprosthetic tissue. Collagenase-positive cells also were found in the periprosthetic tissue associated with common loosening. Collagenase was also found in capillary and postcapillary venule endothelial cells in the richly vascularized aggressive granulomatous tissue. Collagenase was extracted directly from the tissue samples and incubated with soluble Type I collagen. Collagen degradation products then were analyzed by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis, and the three-fourths length degradation product quantitated by gel scanning densitometry. In both aggressive granulomatosis and the common type of loosening, extractable collagenase was found in tissue. No significant differences between the sample groups were detected in respect to total measurable collagenase, however. The extractable collagenase was present in a latent form that could be activated by the organomercurial procollagenase activator, phenylmercuric chloride (PMC). It is likely that interstitial collagenase contributes to rapid growth of reactive infiltrative tissue, loosening of the prosthesis associated with aggressive granulomatosis, and the periprosthetic lytic process associated with the common type of hip prosthesis loosening.     

Picosecond spectrochronography

The general problem of extracting complete (amplitude and phase) information out of an optical signal is discussed. We have shown that the best one can do to determine all essential features of light pulses is to apply simultaneous temporal and spectral analysis to take spectrochronograms with the appropriate shape of the resolution cell on theomegat-plane. We use the term "spectrochronogram" instead of the much broader term "time-resolved spectrum" for a specific measurement result where the resolutionsDeltaomegaandDeltatused are transform correlated. A novel subtractive mount of monochromators has been proposed to overcome the obstacles to experimental realization of uncertainty-principle-limited setups for high spectral resolution picosecond spectrochronography. For the examples of perylene and anthracene molecules, experimental spectrochronograms revealing temporal behavior of hot luminescence lines and, correspondingly, picosecond kinetics of intramolecular vibrational relaxation have been presented. Some further applications of picosecond spectrochronography have been discussed.     

Effect of pre‐germination time of brown rice on serum cholesterol levels of hypercholesterolaemic rats

BACKGROUND: Brown rice is unpolished rice with immeasurable benefits for human health. Brown rice (BR) and pre‐germinated brown rice (PGBR) are known to contain various functional compounds such as γ‐oryzanol, dietary fibre and γ‐aminobutyric acid (GABA). In the present study, the experimental diets containing BR and PGBR (24, 48 h pre‐germination) were used to investigate the influence of pre‐germination time of brown rice on blood cholesterol in Sprague–Dawley male rats. RESULTS: Hypercholesterolaemia and elevation of LDL‐cholesterol were successfully ameliorated by the experimental diets containing BR and PGBR (24 and 48 h pre‐germination). As compared to the control sample, the pre‐germination time had a significant (P < 0.05) effect on blood cholesterol of Sprague–Dawley male rats. It was also found that the significantly (P < 0.05) better effect on lipid profile of hypercholesterolaemic rats was observed by prolonging the pre‐germination time. As compared to non‐germinated brown rice, the germinated brown rice showed the higher cardio‐protective effect on hypercholesterolaemic Sprague–Dawley male rats. CONCLUSION: The present study suggests that the changes of blood cholesterol can be mainly modulated by using the PGBR rather than BR. The prolonging of pre‐germination time led to an increase in the bioactive components, thereby providing a more efficient functional diet affecting the high blood cholesterol. This study suggests that PGBR can be used instead of BR and polished rice in the human diet. Copyright © 2009 Society of Chemical Industry