Effect of abrasion on protective properties of polyester and cotton/polyester blend fabrics.
Explore the source record for details and available documents.
Absorption↗
Biomedical subjects
A Shaw
Publications and source records attributed to A Shaw.
Perfusion corrections for ultrasonic heating in nonperfused media.
The linear bio-heat transfer equation proposed by Pennes is widely used to predict temperature rise in perfused media. In this article, a mathematical relationship between the predicted temperature increase under perfused and nonperfused conditions is derived based on an analysis of the Pennes equation. The perfused temperature at time t and position r, Tperf(r,t) can be calculated from the unperfused temperature history Tunperf(r,t) and the time constant for perfusion, tau: [formula: see text] When the full nonperfused temperature history is not available, a simpler approximate method of estimating the perfused temperature is also suggested, requiring only a knowledge of the time constant for perfusion. Results are given showing the effects of perfusion after different exposure times for a range of beamwidths and perfusion time constants.
Algorithms↗
Engineering enzymes for stability.
There have been many recent developments in elaborating the approaches for stabilizing enzymes by stabilizing the folding state, destabilizing the unfolded state and altering the kinetics of unfolding. However, these represent a series of rules of thumb rather than the reliable principles that would be expected of 'engineering'. Stability is taken to include thermodynamic stability as measured by reversible denaturation, and kinetic stability as measured by the unfolding rate for enzymes that are subject to irreversible denaturation. As such, the factors that affect stability of the folded state versus the unfolded state, as well as factors affecting rates of folding and unfolding, all play a role in maintaining stability. Recent studies on the role of kinetics and the effect that site-specific substitutions have on transition-state free energies add to our understanding of the factors that determine whether or not a particular substitution will result in the measurable stabilization of a protein.
Enzyme Stability↗
Breast screening: a randomised controlled trial in UK general practice of three interventions designed to increase uptake.
STUDY OBJECTIVES: To determine the relative effectiveness of three interventions designed to increase the uptake of breast screening. DESIGN: Randomised controlled trial of a nurse visit with health education (group A), nurse visit without health education (group B), and GP letter (group C). SETTING: The area of south east London served by the Butterfly Walk Breast Screening Unit in Camberwell. PARTICIPANTS: Women aged between 50 and 64 years who were registered with 27 GPs in the Lambeth, Southwark and Lewisham family health services authority and who had not attended for first round screening. MAIN RESULTS: Altogether 799 women were randomly allocated to the three groups. In general, delivering the nurse based interventions proved difficult. In group A, 11.4% (95% CI 7.9, 14.9%) of women subsequently attended for screening compared with 7.8% (95% CI 5.1, 11.4%) in group B and 13.1% (95% CI 7.9, 18.4%) in group C. The differences between the groups (95% CIs) were not statistically significant: A versus C, -1.7% (-8.0, +4.6%); B versus C, -5.3% (-11.3, +0.7%); A versus B, +3.6% (-1.0, +8.2%). CONCLUSIONS: A personal letter from the GP seems to be at least as effective at increasing the uptake of breast screening in non-attenders as a nurse making a home visit to discuss the issue of breast screening, and is not noticeably less effective than a visit at which a health education intervention is delivered. It is possible that the GP letter is considerably more effective than either of the two interview-based interventions. With regard to implementing strategies which will increase breast screening uptake and are cost effective, further trials of similar minimal interventions in primary care are required.
Breast Neoplasms↗
Quaternion contact ribbons: a new tool for visualizing intra- and intermolecular interactions in proteins.
Protein side chain interactions between residues separated by at least one loop or turn or break in the amino acid sequence are called 'nonlocal contacts' in this manuscript, and contiguous sets of such interactions located between segments of secondary structure are called 'contact zones.' A new interactive program, the quaternion contact ribbon tool, has been developed to help protein chemists identify, straighten if twisted, and display contact zones between two neighboring segments of helix.
Binding Sites↗
Resistance to fever induction and impaired acute-phase response in interleukin-1 beta-deficient mice.
We used gene targeting in embryonic stem cells to introduce an IL-1 beta null allele in mice. The IL-1 beta-deficient mice develop normally and are apparently healthy and fertile. The IL-1 beta null mice responded normally in models of contact and delayed-type hypersensitivity or following bacterial endotoxin LPS-induced inflammation. The IL-1 beta-deficient mice showed equivalent resistance to Listeria monocytogenes compared with wild-type controls. In contrast, when challenged with turpentine, which causes localized inflammation and tissue injury, the IL-1 beta mutant mice exhibited an impaired acute-phase inflammatory response and were completely resistant to fever development and anorexia. These results highlight a central role for IL-1 beta as a pyrogen and a mediator of the acute-phase response in a subset of inflammatory disease models, and support the notion that blocking the action of a single key cytokine can alter the course of specific immune and inflammatory responses.
Acute-Phase Reaction↗
Crystal structure and subunit dynamics of the abalone sperm lysin dimer: egg envelopes dissociate dimers, the monomer is the active species.
Lysin is a 16-kD acrosomal protein used by abalone spermatozoa to create a hole in the egg vitelline envelope (VE) by a nonenzymatic mechanism. The crystal structure of the lysin monomer is known at 1.9 A resolution. The surface of the molecule reveals two tracks of basic residues running the length of one surface of the molecule and a patch of solvent-exposed hydrophobic residues on the opposite surface. Here we report that lysin dimerizes via interaction of the hydrophobic patches of monomers. Triton X-100 dissociates the dimer. The crystal structure of the dimer is described at 2.75 A resolution. Fluorescence energy transfer experiments show that the dimer has an approximate KD of 1 microM and that monomers exchange rapidly between dimers. Addition of isolated egg VE dissociates dimers, implicating monomers as the active species in the dissolution reaction. This work represents the first step in the elucidation of the mechanism by which lysin enables abalone spermatozoa to create a hole in the egg envelope during fertilization.
Animals↗
Isoflavone intakes by Japanese were overestimated.
Explore the source record for details and available documents.
Diet↗
Postoperative neuroleptic malignant syndrome.
This report describes neuroleptic malignant syndrome in a previously healthy 6-year-old child. Droperidol and metoclopramide had been given, and hyponatraemia may have been a precipitating factor. Treatment with dantrolene sodium combined with a forced alkaline diuresis resulted in a full recovery.
Child↗
A combined hospital experience with fundoplication and gastric emptying procedure for gastroesophageal reflux in children.
BACKGROUND: Operative treatment of symptomatic gastroesophageal reflux (GER), often together with neurologic feeding disorders, is very common in infancy and childhood. Delayed gastric emptying (DGE) has been observed frequently in association with GER in children. STUDY DESIGN: A retrospective review was performed on 1,200 consecutive patients 18 years of age and younger operated upon for symptomatic GER or neurologic feeding disorders, or both, at two pediatric surgery centers in widely separated geographic areas in the United States of America, to compare the results after fundoplication with or without a gastric emptying procedure (GEP). RESULTS: Operations included gastroesophageal fundoplication (GEF) alone (871 patients), GEF plus GEP (286 patients), reoperative GEF plus GEP (30 patients), and GEP alone (13 patients). Thus, 27 percent of the total and 40 percent of the last 494 children with reflux had a GEP. Delayed gastric emptying with retention of more than 60 percent of an isotope meal appropriate for age at 90 minutes was present in 241 of the 451 children with reflux studied. Major neurologic disorders were present in 219 (25 percent) of 871 children who underwent GEF alone and in 247 (75 percent) of 329 children who had a GEP. All patients operated upon from both hospitals were relieved of recurrent emesis, and those with failure to thrive showed significant weight gain; pulmonary symptoms were relieved in 94 percent. Recurrent GER developed in 47 (5.2 percent) of 901 children who had GEF alone, but in only four (1.2 percent) of 329 patients who had a GEP. CONCLUSIONS: The excellent clinical results with low morbidity in this largest reported clinical experience with GEP in childhood suggest that a GEP should be combined with GEF for symptomatic children who have both GER and DGE. Minimal investigative studies are necessary for most neurologically impaired children who require a feeding gastrostomy.
Adolescent↗
The value of incorporating avoidable factors into perinatal audits.
OBJECTIVE: To assess whether incorporating a system of identifying, classifying and grading avoidable factors into a perinatal audit can be useful in identifying problem areas. DESIGN: Descriptive study. SETTING: Black urban population, Pretoria, South Africa. SUBJECTS: All perinatal deaths of infants weighing more than 1,000 g from urban areas served by Kalafong Hospital between August 1991 and July 1992. METHODS: All perinatal deaths were classified according to the primary obstetric cause of death and neonatal cause of death, and whether any avoidable factors were present which could have contributed to the death. RESULTS: The perinatal mortality rate was 26/1,000 deliveries. Avoidable factors occurred in 58% of perinatal deaths. Our problem areas which were immediately remedial were identified as labour management-related problems, administrative problems in obtaining syphilis results, and estimation of fetal weight. Other problem areas which need to be solved are patient education, early attendance at clinics, improved documentation and continuing education of medical personnel. CONCLUSION: The use of this classification of avoidable factors has enabled the detection of problem areas that can be improved immediately at very little cost.
Cause of Death↗
Perspectives for the control of tuberculosis.
The control of tuberculosis has become more elusive with the increased incidence of HIV, and the continued selection of multidrug-resistant organisms. The intracellular pathogenesis of, and host-response to Mycobacterium tuberculosis present challenges to both classical chemotherapeutic and vaccination approaches, with the organism able to replicate in an unrestricted manner in lung but not other tissues. Adequate control of this pathogen, that has evolved so successfully for its symbiotic exploitation of man, will require complex approaches including additional chemotherapeutics of more acceptable toxicity and efficacy, vaccination and commitment to public health measures. In this review, the worldwide scope of the disease is outlined, and its direct and indirect costs considered. The organism enjoys the protective advantages of a slow replication and of a specialized phagolysosomal intracellular niche, requiring a host-response capable of breaching these cellular barriers. The challenges of current vaccine approaches, including live vaccines, target antigen selection and the antigen delivery and adjuventation necessary to elicit adequate pulmonary responses are discussed. Our current understanding is inadequate to control TB and the rekindling of fundamental experimental approaches to the organism, and the host response it evokes, are essential to generate the preventative and therapeutic means necessary for its worldwide control.
Animals↗
Fitness to drive and the older patient: awareness among hospital physicians.
Explore the source record for details and available documents.
Aged↗
Diffraction quality crystals of protein X from Azotobacter vinelandii.
Protein X from Azotobacter vinelandii has recently been shown to be either a NADPH oxidase or a NADP+ reductase that interacts specifically with ferredoxin I. Single crystals have been obtained by vapor diffusion from polyethylene glycol 4000 solutions containing 100 mM citrate buffer (pH 5.5). The crystals belong to space group P2(1)2(1)2 with unit cell constants a = 68.9 A, b = 76.9 A, c = 52.8 A and one molecule (M(r) 29,000) per asymmetric unit. The crystals diffract to 2.5 A resolution.
Azotobacter vinelandii↗
Acid pH crystallization of the basic protein lysin from the spermatozoa of red abalone (Haliotis rufescens).
A new crystal form of dimeric red lysin, a distinctly basic protein (M(r) = 16 070) from the red abalone (Haliotis rufescens), has been obtained using ammonium sulfate as precipitant with a sodium citrate-boric acid-citric acid buffer at pH 4.5. The acid pH crystal form resulted from a study aimed at developing conditions favorable to the sitting-drop vapor-diffusion crystallization of other abalone lysins which do not crystallize at neutral or basic pH conditions. The space group is P222(1) with cell dimensions a = 51.2, b = 47.0, c = 123.8 A and two molecules per asymmetric unit.
Journal Article↗
2.2 A structure of oxy-peroxidase as a model for the transient enzyme: peroxide complex.
The Fe+3-OOH complex of peroxidases has a very short half life, and its structure cannot be determined by conventional methods. The Fe+2-O2 complex provides a useful structural model for this intermediate, as it differs by only one electron and one proton from the transient Fe+3-OOH complex. We therefore determined the crystal structure of the Fe+2-O2 complex formed by a yeast cytochrome c peroxidase mutant with Trp 191 replaced by Phe. The refined structure shows that dioxygen can form a hydrogen bond with the conserved distal His residue, but not with the conserved distal Arg residue. When the transient Fe+3-OOH complex is modelled in a similar orientation, the active site of peroxidase appears to be optimized for catalysing proton transfer between the vicinal oxygen atoms of the peroxy-anion.
Binding Sites↗
Achieving dietary recommendations: whole-grain foods in the Food Guide Pyramid.
The Food Guide Pyramid illustrates USDA's food guide developed to help people follow the Dietary Guidelines for Americans. Unlike earlier food guides, the new food guide specifies foods for a total diet; that is, it addresses both concerns about adequacy and moderation. The food guide recommends increased intakes of the vegetable, fruit, and grain groups with special emphasis on dark-green leafy vegetables, legumes, and whole-grain products. These foods are important sources of several vitamins and minerals, complex carbohydrates, and dietary fiber, and they are generally low in fat. Analyses of expected nutrient levels provided by the food guide diet patterns indicate that the nutrient contribution of whole-grain products is particularly important for diets at lower calorie levels. In these diets, it is recommended that at least half the number of servings in the grain group be whole-grain products. In all diets, it is recommended that several servings of whole-grain products be included each day. Average intakes of vegetables, fruits, and grain products are less than recommended. The pyramid graphic has been especially helpful in emphasizing to the public the importance of increased consumption of vegetables, fruits, and grain products for a healthful diet.
Diet↗