CbiX: a novel metal-binding protein involved in sirohaem biosynthesis in Bacillus megaterium.
Explore the source record for details and available documents.
Amino Acid Sequence↗
Biomedical subjects
M Warren
Publications and source records attributed to M Warren.
Local repolarization abnormalities induced by transcatheter radiofrequency ablation in pigs.
Radiofrequency (RF) ablation alters action potential repolarization of myocardial cells and, theoretically, this should induce ST-T segment changes in the ECG. Since these ECG abnormalities have been rarely reported in patients submitted to RF ablation we assess the ability of the procedure to cause ST-T segment changes in local electrograms. Epicardial ECG mapping was performed in 17 anesthetized open chest pigs submitted to endocardial (n = 9) or to epicardial (n = 8) unipolar radiofrequency ablation (500 kHz, 20 W for 5-10 s). To characterize the cellular electrophysiological alterations induced by RF ablation transmembrane action potentials were recorded at various distances from the ablation lesion; these were compared with seven control pigs. Endocardial RF ablation induced a transient (< 5 min) change of 6.1 +/- 2.4 mV in T wave amplitude (baseline: 12.8 +/- 5.6 mV, P < 0.001) in 141 out of 269 epicardial electrodes. T wave changes were associated with shortening in local activation time (20.1 +/- 2.3 ms at baseline vs 18.5 +/- 2.5 ms at 60 s after ablation, P = 0.03). RF current caused persistent St segment elevation at the center of the ablation lesion with no transmural expansion. Intracellular potentials along a 2-6 mm wide myocardial band bordering the RF lesion lower amplitude (101 +/- 7.0 mV vs 71 +/- 23 mV, P < 0.01) and shorter duration (254 +/- 44 ms vs 156 +/- 29 ms, P < 0.01) than control hearts. The center of the ablation lesion was electrically unexcitable. We concluded that RF ablation alters cellular electrophysiology in small areas surrounding the ablation lesion and this causes short-lasting transmural changes in T 3 wave amplitude and nontransmural ST segment elevation.
Action Potentials↗
Addressing information security training and awareness within the European healthcare community.
This paper discusses the need to promote information security issues within modern healthcare establishments and the consequent need for appropriate training and awareness initiatives. Security is an area of extreme significance in healthcare information systems but, whilst the need is generally recognised, many personnel are not familiar with even basic concepts and procedures. As such, adequate promotion of security through training and awareness initiatives is viewed as a vital first step. The paper highlights a series of basic factors that healthcare establishments (HCEs) should consider in setting up a training and awareness framework. The discussion then examines a number of ways in which relevant information may be disseminated to staff, including security guidelines, training seminars and world-wide web based services. The paper is largely based upon work that is currently being conducted as part of the Health Telematics ISHTAR (Implementing Secure Healthcare Telematics Applications in euRope) project.
Awareness↗
Multilocus DNA fingerprinting and RAPD reveal similar genetic relationships between strains of Oreochromis niloticus (Pisces: Cichlidae).
Two molecular techniques which reveal highly variable DNA polymorphisms, RAPD and multilocus DNA fingerprinting, were used to evaluate genetic diversity between six aquacultural strains of Oreochromis niloticus (tilapia) from the Philippines. The results using both techniques were in close agreement. Within-strain heterozygosity values were similar and were correlated between the two data sets, but statistical errors associated with the RAPD data set were lower. Although genetic distances between strains were greater using DNA fingerprinting, the distances measured using both methods were significantly correlated. Both methods were useful in estimating variation between strains, but they offered different advantages. RAPD was technically easier to perform and produced results with low statistical error, whereas DNA fingerprinting detected greater genetic differentiation between strains. The theoretical basis for using RAPD and multilocus minisatellite markers for population studies is discussed.
Animals↗
Species identification of members of the Streptococcus milleri group isolated from the vagina by ID 32 Strep system and differential phenotypic characteristics.
The importance of bacterial vaginosis as a risk factor in obstetric and gynecological infections has recently been recognized. The bacterial vaginosis group of organisms includes members of the Streptococcus milleri group, the identification of which has caused much confusion. We prospectively surveyed the rates of carriage of S. milleri group organisms in 397 high vaginal swabs received in our laboratory. For the identification of 99 clinical isolates and 23 control strains, we compared the results obtained by the rapid ID 32 Strep system (Analytab Products) and by a scheme utilizing six differential phenotypic characteristics (presence of beta-N-acetylglucosaminidase, alpha-glucosidase, beta-D-fucosidase, beta-galactosidase, beta-N-acetylgalactosaminidase, and beta-glucosidase) as described by Whiley et al. (R. A. Whiley, H. Fraser, J. M. Hardie, and D. Beighton, J. Clin. Microbiol. 28:1497-1501, 1990). We identified Streptococcus anginosus in 18% and Streptococcus constellatus in 0.05% of the specimens examined. Of the isolates of S. anginosus that reacted with grouping antisera, 20 of 25 belonged to Lancefield group F. The incubation conditions for bacterial cultures and for reaction mixtures affected the results of phenotypic characterization in the production of alpha-glucosidase, beta-galactosidase, and beta-glucosidase. However, by using bacterial cultures grown under hypercapnic conditions and incubating the reaction mixtures aerobically, consistent phenotypic characteristics were obtained, allowing identification similar to that obtained by the ID 32 Strep system. We therefore recommend the phenotypic scheme as an inexpensive, reliable, and convenient method for the initial identification of species of the S. milleri group.
Antibodies, Bacterial↗
Including occupational therapy in low vision rehabilitation.
Explore the source record for details and available documents.
Humans↗
Providing low vision rehabilitation services with occupational therapy and ophthalmology: a program description.
This article describes a low vision rehabilitation program operating within a hospital-based outpatient rehabilitation clinic. The program uses a team approach combining ophthalmology and occupational therapy services. Patients are referred to the program by their primary care physician for a low vision evaluation completed jointly by the ophthalmologist and occupational therapist. The ophthalmology portion of the evaluation includes assessment of visual acuity, contrast sensitivity function, and macular perimetry with a scanning laser ophthalmoscope. The occupational therapy evaluation focuses on assessing the functional limitations experienced by the patient due to the vision loss and determining how the patient is best able to use remaining vision to complete daily activities. Occupational therapy treatment emphasizes training the patient to use remaining vision as efficiently and effectively as possible to complete daily activities and includes training in use of optical devices. Because of the specialized nature of the service provided, additional postgraduate preparation is needed to enable occupational therapists to provide effective low vision rehabilitation.
Activities of Daily Living↗
Nd: YAG laser thermocoagulation of the prostate: the barbecue effect.
OBJECTIVE: To determine systematically the depth of coagulation necrosis induced during Nd: YAG laser irradiation in the canine prostate model, and to define the correlation of laser dose with depth of the lesions. METHODS: We investigated the effect of various dosimetries on prostatic tissue of 17 mongrel canines using laser power in the range of 8 to 60 watts (W) at varying exposure times, from 20 to 300 seconds (S). Applied energy ranged from 1,000 to 5,500 Joules (J). RESULTS: Three distinct features were observed. First, deep coagulation necrosis was induced only with laser regimens of > or = 2,100J, suggesting that there is a threshold of energy that must be overcome in order to achieve significant coagulation depth. Second, the deepest coagulation necrosis was achieved with a low power slow-heating regimen (15W X 180S). Tissue surface changes appeared to be responsible for the reduced depth of coagulation necrosis seen with higher power regimens (> 20 W). Third, increasing the energy above 3,600J did not augment the depth of coagulation, suggesting that a steady state for temperature distribution is reached at that rate of heating. CONCLUSIONS: Our study suggests that in the canine prostate, a low power slow-heating regimen of 15W X 180S may yield larger volumes of coagulation necrosis than other regimens.
Animals↗
Low-power laser radiation for the treatment of benign prostatic hyperplasia: initial clinical experience.
Fifteen patients with significant bladder outlet obstruction secondary to benign prostatic hyperplasia (BPH) were entered in a Phase II open pilot study designed to evaluate the effectiveness of a low-power-slow-heating (15 W x 180 seconds) laser regimen. Laser prostatectomies were performed with a right-angle firing neodymium:YAG laser fiber. Perioperative morbidity was minimal. Nine patients (60%) were able to void on their own within 72 hours after the procedure. The mean postoperative need for catheter drainage was 3.8 days (range 1 to 12). With a mean follow-up of 5 months (range 3-15 months), the improvement of the mean peak urinary flow rate was from 12.8 to 29 mL/sec, the mean postvoiding residual volume was reduced from 100 to 35 mL, and the AUA Symptom Score improved from 28.5 to 6. None of the patients required retreatment, and all the patients were pleased with the outcome. These results suggest that the laser regimen used in our study is safe and effective for the treatment of BPH.
Aged↗
Cranial computed tomography of elderly patients: an evaluation of its use in acute neurological presentations.
We assessed the use of cranial computed tomography (CT) in elderly patients with acute neurological deficit and its influence on patient management. Clinical notes from 100 consecutive CT referrals from geriatric admissions presenting with acute neurological deficit were reviewed and categorized according to clinical presentation. CT results and subsequent therapy were recorded. Twenty of the patients had treatable lesions (in 6 out of 14 patients with signs atypical of stroke and 7 out of 19 patients with acute confusion). These two groups contained 68% of all treatable lesions found. Forty-four scans yielded no new diagnostic information; these included all scans for transient ischaemic attacks and for progression of stroke. The remaining scans yielded information regarding pathology but did not alter patient management. CT is a valuable first-line investigation in elderly patients presenting with signs atypical of stroke and unexplained confusion but may be less useful in patients with other presentations.
Acute Disease↗
A hierarchical model for evaluation and treatment of visual perceptual dysfunction in adult acquired brain injury, Part 1.
A developmental framework for evaluation and treatment of visual perceptual deficits in adults with acquired brain injury is presented. The framework is based on a review of research conducted on post-cerebrovascular accident subjects and subjects with traumatic brain injuries. Visual perceptual skill is conceptualized as a hierarchy of skill levels that interact and subserve each other. Higher level skills evolve from integration of lower level skills and are subsequently affected by disruption of lower level skills. Oculomotor control, visual field, and acuity form the foundation skills, followed by visual attention, scanning, pattern recognition, memory, and visual cognition. Brain injury can affect the integrity and interaction of each skill level and affect daily living function. Application of this framework dictates a bottom-up approach to evaluation and treatment, emphasizing identification and remediation of deficits in lower level skills to allow normal integration of higher level skill.
Adult↗
A hierarchical model for evaluation and treatment of visual perceptual dysfunction in adult acquired brain injury, Part 2.
A framework for evaluation and treatment of visual perceptual dysfunction in adults with acquired brain injury is presented. The framework is based on the concept of a hierarchical structure of perceptual skill levels that interact and subserve one another. Higher level skills in the structure evolve from the integration of lower level skills and are subsequently affected by disruption of the lower level skills. Oculomotor control, the visual fields, and visual acuity form the foundation skills in the framework, followed by visual attention, scanning, pattern recognition, memory, and visual cognition. The order of evaluation and treatment is dictated by the framework. Emphasis is placed on identification and remediation of deficits in the lower level skills that will cause spontaneous improvement of higher level skills. Three treatment principles and five training guidelines are presented that reflect this concept. Specific examples of treatment tasks are provided.
Adult↗
Rapid purification and reconstitution of a plant vacuolar ATPase using Triton X-114 fractionation: subunit composition and substrate kinetics of the H(+)-ATPase from the tonoplast of Kalanchoë daigremontiana.
A rapid procedure for the purification and reconstitution into proteoliposomes of the H(+)-translocating ATPase of plant vacuolar membranes is reported. It involves fractionation of the tonoplast with Triton X-114, resolubilization of the ATPase with octyl glucoside in the presence of a mixture of phosphatidylcholine, phosphatidylserine and cholesterol (27:53:20, by weight), and removal of the detergent by gel-filtration. Starting with partially purified vacuolar membranes, the procedure can be accomplished in about 2 hours. It has been applied to the H(+)-ATPase from the crassulacean plant Kalanchoë daigremontiana, from which it yields vesicles with a specific ATPase activity of about 3 mumol/min per mg protein. The purified enzyme contains polypeptides of apparent molecular mass 72, 57, 48, 42, 39, 33 and 16 kDa; these polypeptides also co-sediment on centrifugation of the solubilized ATPase through glycerol gradients. The 16-kDa subunit is labelled with [14C]dicyclohexylcarbodiimide. There is no evidence for a larger ATPase subunit in this preparation. The reconstituted ATPase proteoliposomes undergo ATP-dependent acidification, which can be measured by quenching of the fluorescence of 9-aminoacridine. The initial rate of fluorescence quenching is a measure of the rate of H+ translocation, and is directly proportional to the vesicle protein concentration, so the preparation is suitable for studying the kinetics of the tonoplast H(+)-ATPase. The dependence of the rate of fluorescence quenching on the concentration of MgATP is well fitted by the Michaelis equation, with a Km value about 30 microM. ATP can be replaced by dATP, ITP, GTP, UTP or CTP, and Mg2+ by Mn2+ or Ca2+; kinetic parameters for these substrates are reported. In contrast, hydrolysis of MgATP shows complex kinetics, suggestive either of negative cooperativity between nucleotide-binding sites, or of two non-interacting catalytic sites. Both the hydrolytic and the H(+)-translocating activities of the proteoliposomes are inhibited by nitrate, though not in parallel, the latter activity being the more sensitive. Both activities are inhibited in parallel by bafilomycin A1, which does not produce complete inhibition; the bafilomycin-insensitive component has complex ATPase kinetics similar to those of the uninhibited enzyme.
Adenosine Triphosphate↗
Reconstitution and kinetics of vacuolar H(+)-translocating ATPases from plants and animals.
Explore the source record for details and available documents.
Adenosine Diphosphate↗
Periodicity of presentations of drugs of abuse and overdose in an emergency department.
In order to determine whether temporal factors impact on drugs of abuse and overdose presentations to an urban emergency department, we studied the records of 630 consecutive drug overdose presentations over a period from October 1987 to March 1990. Particular note was made of the time of day of presentation along with the nature of the drug(s) ingested. A significant curve (p less than 0.0005) was obtained for a 24 h period with a peak time of presentation being 6:32 pm (95% confidence interval of 1 h 54 min). Significant periodic rhythms were noted for cocaine, opiates, alcohol, analgesics, marijuana, and benzodiazepines. A 4.8 h periodic rhythm was demonstrated for cocaine, marijuana and alcohol-in-combination. We conclude that the emergency department should be most prepared to treat the drug overdose patient in the early evening and emergency department staffing should reflect this peak in demand.
Alcoholism↗
Susceptibility of Macaca fascicularis monkeys from Mauritius to different species of Plasmodium.
Macaca fascicularis monkeys from Mauritius were shown to be susceptible via sporozoite inoculation to 7 species of Plasmodium (P. fragile, P. coatneyi, P. gonderi, P. inui, P. cynomolgi, P. knowlesi, and P. fieldi), indigenous to macaques in southeastern Asia. Four monkeys were sequentially infected with different species of Plasmodium to determine maximum and course of parasitemia. In 2 nonsplenectomized monkeys, P. fragile developed maximum parasite counts of only 134 and 155/microliters. For Plasmodium knowlesi, a parasite that is life-threatening to rhesus monkeys, maximum parasite counts were 4,278 and 7,440/microliters. Plasmodium coatneyi developed to what must be considered as moderate levels. After animals underwent splenectomy, parasite counts of P. coatneyi were 58,280, 89,094, 4,464, and 43,524/microliters. The maximum parasite counts for P. gonderi (13,508 and 21,576/microliters) and P. fieldi (1,767 and 17,836/microliters) were lower than would be expected in M. mulatta. In 2 monkeys that developed patent parasitemia with P. inui, the maximum parasite counts (95,046 and 728,748/microliters) indicated that this parasite may be the best adapted species for development in these animals once infection is established. Finally, the reinfection of 2 monkeys with P. cynomolgi suggested that some animals may be basically more resistant than others, whether splenectomized or not, to the production of high-density parasitemia.
Animals↗
The vacuolar H(+)-translocating ATPase of renal tubules contains a 115-kDa glycosylated subunit.
Kidney microsomes were fractionated with Triton X-114, to give a fraction enriched in the renal tubule H(+)-translocating ATPase, as judged by the sensitivity of its ATPase activity to bafilomycin A1, and its content of two polypeptides recognized by antibodies directed against subunits of plant tonoplast ATPases. This fraction contained a polypeptide of apparent molecular mass of 115 kDa, that was recognized by an antibody to the largest (120 kDa) subunit of chromaffin-granule membrane H(+)-ATPase, and, like this subunit, was reduced in molecular weight on treatment with glycopeptidase F. We conclude that, like other mammalian vacuolar H(+)-ATPases, the kidney H(+)-ATPase contains a large, glycosylated subunit.
Adrenal Gland Neoplasms↗
Comparison of two commercial kits for identifying and biotyping Haemophilus parainfluenzae.
The Minitek system and the more recently introduced Micro Scan HNID panels for the identification and biotyping of 98 V dependent Haemophilus isolates were compared. Identical results were obtained for 77 isolates. The discrepancy in the results of ornithine and urease was accounted for mainly by the mismatching of the identification by the two kits. When 13 isolates of H parainfluenzae with mismatched biotypes were re-examined, the results from Micro Scan correlated with 92% of those obtained by Christensen's urea broth and 100% by the ornithine test (Lab M); the corresponding figures for Minitek were 61% and 30%, respectively. Micro Scan was easy to handle on the bench and results were ready on the same day. These results suggest that further work is required to assess these two systems for the biotyping of H parainfluenzae.
Bacterial Typing Techniques↗