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Biomedical subjects

R Evans

Publications and source records attributed to R Evans.

At least 91 records · Page 5Linked to original sources
PubMed2001

Commercially available ocular hypotensive products: preservative concentration, stability, storage, and in-life utilization.

PURPOSE: With the recent addition of several new ocular hypotensive agents to the pharmacopeia, glaucomatologists have more choices in selection of pharmacotherapy. Several of these new agents have special storage requirements or a limited shelf-life when stored under certain conditions. METHODS: To better inform physicians and patients about pharmaceutical issues relating to the correct usage or storage of ophthalmic products used to manage glaucoma, the authors reviewed the US Food and Drug Administration requirements for sterile ophthalmic preparations, together with the United States Pharmacopeia 24. They also reviewed the Ophthalmic Physicians Desk Reference (2000 edition) for pharmaceutical information regarding branded glaucoma-solution products. RESULTS: The US Food and Drug Administration requires that both analytical tests (e.g., concentration of preservative) and functional tests (e.g., preservative efficacy tests) be undertaken to show the sterility of liquid products. In addition, extensive chemical testing of the potency and stability of the active molecule and other physicochemical properties of the formulation are needed to justify expiration dates and determine the shelf-life of the product. Of the 19 products that met the search criteria, 17 (89%) used benzalkonium chloride as the primary preservative agent, in weight-to-volume ratios ranging from 0.004% (Betagan, Optipranolol) to 0.020% (Xalatan). Five products had a warning against freezing, and 12 required protection from light. Only one product required refrigerated storage before opening, though most products specify an upper range for temperature exposure during storage. CONCLUSIONS: Physicians and their patients need to be aware of the special requirements of each product to assure that they receive the dose of medication as prescribed. The distinction between stability during storage before dispensing (shelf-life) and the acceptable "in-use life" after opening of the dispensed product are essential for the safe and efficacious management of glaucoma.

Antihypertensive Agents↗
PubMed2001

Creating a peaceful school learning environment: a controlled study of an elementary school intervention to reduce violence.

OBJECTIVE: The impact of a manual-based antiviolence program on the learning climate in an elementary school over 4 years was compared with the outcome in a control school. METHOD: The two schools were matched for demographic characteristics. The intervention in the experimental school was based on zero tolerance for bullying; the control school received only regular psychiatric consultation. Disciplinary and academic achievement data were collected in both schools. RESULTS: The experimental school showed significant reductions in discipline referrals and increases in scores on standardized academic achievement measures. CONCLUSIONS: A low-cost antiviolence intervention that does not focus on individual pathology or interfere with the educational process may improve the learning environment in elementary schools.

Achievement↗
PubMed2001

The dental health and caries-related microflora in children with craniosynostosis.

OBJECTIVE: To compare levels of dental caries, bacterial dental plaque, gingivitis, enamel defects, and caries-related microflora in children with and without craniosynostosis. STUDY GROUP: Fifty-seven children with craniosynostosis and their matched controls. OUTCOME MEASURES: The decayed, missing, and filled teeth and surfaces in both the deciduous (dmfs and dmft) and the permanent dentition (DMFS and DMFT). The plaque and gingivitis scores and developmental enamel defects were also recorded. The caries-related microflora was sampled using an alginate swab and the prevalence of Streptococcus mutans and Lactobacillus and Candida species were recorded. RESULTS: The dmfs (p <.02) and dmft (p <.01) were significantly greater in the control children. The plaque score for the deciduous dentition only (p <.02) and also the gingivitis score for the permanent teeth only (p <.008) in the craniosynostosis group were significantly greater. The total aerobic bacterial count (p <.004), anaerobic count (p <.002), and Candida count (p <.05) were significantly greater in the control group. The proportion of S. mutans both as a percentage of the total anaerobic count (p <.04) and the total streptococcal count (p <.05) was significantly greater in the control group.

Acrocephalosyndactylia↗
PubMed2001

Tasco-Forage: IV. Influence of a seaweed extract applied to tall fescue pastures on sensory characteristics, shelf-life, and vitamin E status in feedlot-finished steers.

Tasco-Forage is an Ascophyllum nodosum seaweed-based product that has increased antioxidant activity in both plants and animals. Endophyte (Neotyphodium coenophialum ([Morgan-Jones and Gams] Glenn, Bacon, and Hanlin)-infected and uninfected tall fescue (Festuca arundinacea Schreb.) pastures in Virginia and Mississippi during 1997 were treated or not with 3.4 kg Tasco/ha in April and July. There were two replications of each treatment at each location. Forty-eight steers (6/replication) grazed pastures at each location (n = 96) from April to October prior to transportation to Texas Tech, Lubbock, for finishing during a 160-d period in the feedlot. Blood (antemortem) and liver (postmortem) samples were collected. After slaughter and chilling, the left strip loins (IMPS #180) were collected from three randomly selected steers from within each pasture replication (n = 48). Strip loins were vacuum-packaged and stored at 2 degrees C. At postmortem d 7, 14, 21, and 28, strip loins were removed from packaging and fabricated into 2.54-cm steaks. Following each fabrication day postmortem, the strip loins were repackaged and stored at 2 degrees C until the following postmortem time. After the prescribed fabrication, steaks were overwrapped with polyvinyl chloride film, subjected to simulated retail display at 2 degrees C for up to 3 d, and subjective and objective color were evaluated daily by a trained panel. Steaks from Mississippi steers that had grazed Tasco-treated fescue retained higher (P < 0.05) CIE a* color scores throughout retail display. Steaks were more uniform and had less discoloration and less browning (P < 0.05) if they were from steers that had grazed Tasco-treated fescue, and the effect was greatest for steers from Mississippi (location x Tasco interaction; P < 0.05). The endophyte in tall fescue may decrease uniformity and increase lean discoloration and two-toning of beef steaks when removed from vacuum packaging on or beyond d 21 postmortem (endophyte x Tasco x postmortem day interaction: P < 0.05). Vitamin E in liver was increased (P < 0.06) and serum vitamin E was decreased (P < 0.09) in steers that had grazed the treated pastures. These experiments indicated that Tasco applied to tall fescue during the grazing season can improve color stability and extend beef shelf-life, particularly in cattle grazing infected tall fescue. The mode of action of Tasco is not clear, but antioxidants and specific vitamins may be involved.

Aging↗
PubMed2001

The UK education of overseas students in speech and language therapy.

Informal evidence suggests that many overseas speech and language therapists (SLTs) either do not return to their home country on qualification or do not work as SLTs in the public sector. Many factors may contribute to this situation. However, concern that it may result in part from a poor match between UK SLT education and the demands of the role in other countries, led the Royal College of Speech and Language Therapists (RCSLT) to fund a study of overseas SLT students' experiences of UK qualifying courses. The study involved questionnaires and interviews with current students and those qualifying since May 1994. The focus of this paper is the respondents' experiences of studying and working in the UK, their views of the advantages and disadvantages of working in their home countries and the UK and supportive strategies that UK universities and other agencies might adopt. Implications of the findings are discussed.

Consumer Behavior↗
PubMed2001

Development of a residency/MPH program.

BACKGROUND AND OBJECTIVES: Public health complements the care physicians provide to patients. Few residencies, with the exception of preventive medicine residencies, offer trainees the opportunity to obtain a public health degree. The University of California, San Francisco-Fresno (UCSF-Fresno) Family Practice Program and California State University-Fresno (CSU-Fresno) spearheaded the creation of a combined residency/MPH program at the UCSF-Fresno Medical Education Program. METHODS: We developed a combined residency/MPH program that allows family practice residents to obtain an MPH degree during their residency training years. We describe the development process, which included initiation of the program, setting goals and objectives, identifying MPH course content and funding, and selecting applicants for entry into the program. RESULTS: The program was successfully funded, and the course content was developed. Participant selection, registration, and enrollment procedures have now been developed. Performance standards have been established, and scheduling conflicts have been addressed. The program has thus far enrolled 29 residents and faculty. Nearly one third have dropped out of the MPH component of the program, mostly because of the workload involved in simultaneous residency and MPH training. CONCLUSIONS: Other training programs can replicate a combined residency/MPH program if a strong relationship with a nearby university offering a MPH degree can be forged. The experience at UCSF-Fresno can help guide others contemplating a combined residency/MPH program.

California↗
PubMed2001

Efficacy of spinal manipulation for chronic headache: a systematic review.

BACKGROUND: Chronic headache is a prevalent condition with substantial socioeconomic impact. Complementary or alternative therapies are increasingly being used by patients to treat headache pain, and spinal manipulative therapy (SMT) is among the most common of these. OBJECTIVE: To assess the efficacy/effectiveness of SMT for chronic headache through a systematic review of randomized clinical trials. STUDY SELECTION: Randomized clinical trials on chronic headache (tension, migraine and cervicogenic) were included in the review if they compared SMT with other interventions or placebo. The trials had to have at least 1 patient-rated outcome measure such as pain severity, frequency, duration, improvement, use of analgesics, disability, or quality of life. Studies were identified through a comprehensive search of MEDLINE (1966-1998) and EMBASE (1974-1998). Additionally, all available data from the Cumulative Index of Nursing and Allied Health Literature, the Chiropractic Research Archives Collection, and the Manual, Alternative, and Natural Therapies Information System were used, as well as material gathered through the citation tracking, and hand searching of non-indexed chiropractic, osteopathic, and manual medicine journals. DATA EXTRACTION: Information about outcome measures, interventions and effect sizes was used to evaluate treatment efficacy. Levels of evidence were determined by a classification system incorporating study validity and statistical significance of study results. Two authors independently extracted data and performed methodological scoring of selected trials. DATA SYNTHESIS: Nine trials involving 683 patients with chronic headache were included. The methodological quality (validity) scores ranged from 21 to 87 (100-point scale). The trials were too heterogeneous in terms of patient clinical characteristic, control groups, and outcome measures to warrant statistical pooling. Based on predefined criteria, there is moderate evidence that SMT has short-term efficacy similar to amitriptyline in the prophylactic treatment of chronic tension-type headache and migraine. SMT does not appear to improve outcomes when added to soft-tissue massage for episodic tension-type headache. There is moderate evidence that SMT is more efficacious than massage for cervicogenic headache. Sensitivity analyses showed that the results and the overall study conclusions remained the same even when substantial changes in the prespecified assumptions/rules regarding the evidence determination were applied. CONCLUSIONS: SMT appears to have a better effect than massage for cervicogenic headache. It also appears that SMT has an effect comparable to commonly used first-line prophylactic prescription medications for tension-type headache and migraine headache. This conclusion rests upon a few trials of adequate methodological quality. Before any firm conclusions can be drawn, further testing should be done in rigorously designed, executed, and analyzed trials with follow-up periods of sufficient length.

Chiropractic↗
PubMed2001

A cultural gap.

Explore the source record for details and available documents.

Cultural Diversity↗
PubMed2000

A rapid method to detect dried saliva stains swabbed from human skin using fluorescence spectroscopy.

Saliva on skin is important in forensic trace evidence. If areas where saliva is present can be outlined, this may lead to DNA analysis and identification. This study describes a rapid and non-destructive method to detect dried saliva on the surface of the skin by fluorescence spectroscopy. Eighty-two volunteers deposited samples of their own saliva on the skin of their ventral forearm. A control sample of water was deposited at three different sites on the contralateral arm. Saliva and water control were then allowed to air-dry. Swab samples were taken from dried saliva and control sites and were dissolved in 0.1M KCl solution. Emission spectra were obtained from the solution and were characterized by a principal maximum at 345-355nm with excitation at 282nm. The fluorescence emission intensity was greater than background readings obtained from the control swab site in 80 of 82 volunteers (approximately 97.6%). The fluorescence profile of saliva samples were similar to those obtained from aqueous samples of pure amylase and tryptophan, an endogenous fluorophore in alpha-amylase. The presence of an emission peak at 345-355nm with excitation at 282nm could provide a strong presumptive indication of saliva deposition.

Adult↗
PubMed2000

Influence of capillary condensation on the near-critical solvation force.

We argue that in a fluid, or magnet, confined by adsorbing walls which favor liquid, or the (+) phase, the solvation (Casimir) force in the vicinity of the critical point is strongly influenced by capillary condensation which occurs below the bulk critical temperature T(c). At T slightly below and above T(c), a small bulk field h<0, which favors gas, or the (-) phase, leads to residual condensation and a solvation force which is much more attractive (at the same large wall separation) than that found exactly at the critical point. Our predictions are supported by results obtained from density-matrix renormalization-group calculations in a two-dimensional Ising strip subject to identical surface fields.

Journal Article↗
PubMed2000

Density functional for a model colloid-polymer mixture

We present a density functional theory for mixtures of (hard sphere) colloidal particles and ideal polymers. For this extreme nonadditive system we employ a fundamental measures approach to construct a functional which incorporates the correct dimensional crossover and the exact low density limit. In bulk fluid mixtures the functional yields the same free energy and, therefore, the same gas-liquid (demixing) transition as given by free-volume theory. It generates consistent pair correlation functions; the partial structure factors S(ij)(k) diverge, as k-->0, at the critical point obtained from the free energy. Our results for the structure agree well with those from simulation and Percus-Yevick theory.

Journal Article↗
PubMed2000

How much blood is really lost in total knee arthroplasty?. Correct blood loss management should take hidden loss into account.

In total knee arthroplasty (TKA) the total blood loss is composed of 'visible' blood loss from the surgical field and wound drainage, and blood loss into the tissues which is hidden. Blood management should be aimed at addressing the total blood loss. The measured loss is generally an underestimation of the 'true' loss, which can be calculated. Sixty-three TKAs were prospectively studied at the Avon Orthopaedic Centre, Bristol, UK. All but two TKAs were performed under a tourniquet. Thus the intraoperative blood loss was usually zero. Reinfusion of drained blood was carried out when appropriate. The drainage and volume reinfused were recorded. None of the patients studied received a bank blood transfusion. All patients had FBC including haematocrit (Hct) pre- and post-operatively. Each patients height and weight were recorded pre-operatively. The true total blood loss was calculated using height, weight and pre- and post-op Hct. Subtracting the visible loss gives the hidden loss. As the object of the study was to determine the proportion of blood loss that is hidden, rather than document blood loss in general, seven patients with very large blood losses were excluded from the study to minimise the effect of haemodilution on our calculation. The threshold chosen was 1.5 l. In TKA, the mean total calculated blood loss was 1474 ml. The mean hidden loss was 735 ml. It can be seen that the hidden loss is 50% of the total loss, making the true loss following TKA twice the volume usually recorded. This is due to bleeding into the tissues and haemolysis when reinfusion is carried out. It is concluded that when planning blood management after TKA, account should be taken of the probable substantial hidden blood loss.

Journal Article↗
PubMed2000

The conformation of the transcription factor TFIIB modulates the response to transcriptional activators in vivo.

The general transcription factor TFIIB plays a crucial role in the assembly of the transcriptional preinitiation complex and has also been proposed as a target of transcriptional activator proteins (reviewed in [1]). TFIIB is composed of two domains which are engaged in an intramolecular interaction that is disrupted upon interaction with the activation domain of the Herpesvirus VP16 protein in vitro [2] [3]. The significance of this event for transcriptional activation is not known, however. The amino-terminal intramolecular interaction domain is the most conserved region of TFIIB and plays a role in transcription start-site selection [4] [5] [6]. In addition, we have shown previously that the integrity of this region is required for transcriptional activation in vivo [4]. Here, we have defined a charge cluster at the amino terminus of TFIIB that is required for transcriptional activation in vivo. We found that this domain determines the affinity of the TFIIB intramolecular interaction and the ability of TFIIB to interact with a transcriptional activation domain, but not with components of the holoenzyme. Our results suggest that the intramolecular interaction in TFIIB regulates transcriptional activation in vivo.

Amino Acid Sequence↗
PubMed2000

Alpha2 macroglobulin and the risk of Alzheimer's disease.

BACKGROUND: alpha2 Macroglobulin is a panproteinase inhibitor that is found immunohistochemically in neuritic plaques, a requisite neuropathologic feature of AD. Recently, a pentanucleotide deletion near the 5' end of the "bait region" of the alpha2 macroglobulin (A2M) gene was reported to be associated with AD in a large cohort of sibpairs, in which the mutation conferred a similar odds ratio with AD as the APOE-epsilon4 allele for carriers of at least one copy of the A2M gene (Mantel-Haenszel odds ratio, 3.56). METHODS: We studied three independent association samples of AD patients (n = 309) with an age range of 50 to 94 years and representative controls (n = 281) to characterize the allele frequency of the pentanucleotide deletion in this cohort. We detected the mutation near the 5' splice site of exon 18 using standard PCR and restriction fragment length polymorphism methods. The results were adjusted for age, gender, education, and APOE polymorphism. RESULTS: We found that the A2M gene polymorphism conferred an increased risk for AD, with an estimated Mantel-Haenszel ratio of 1.5 (95% CI 1.1 to 2.2; p = 0.025). There was no age- or gender-dependent increase in A2M gene allele frequencies in AD patients compared with controls. The combined sample showed the expected association between AD and APOE-epsilon 4. In one of our three samples there was an interaction between the A2M and APOE-epsilon4 genes, but the other two samples showed no interaction between the two risk factors. CONCLUSIONS: Our data support an association between the A2M gene and AD. This association is less pronounced, however, in our cohort than in the previously reported sample of sibpairs.

Aged↗
PubMed2000

Sustained kilowatt lasing in a free-electron laser with same-cell energy recovery

Jefferson Laboratory's kW-level infrared free-electron laser utilizes a superconducting accelerator that recovers about 75% of the electron-beam power. In achieving first lasing, the accelerator operated "straight ahead" to deliver 38-MeV, 1.1-mA cw current for lasing near 5 &mgr;m. The waste beam was sent directly to a dump while producing stable operation at up to 311 W. Utilizing the recirculation loop to send the electron beam back to the linac for energy recovery, the machine has now recovered cw average currents up to 5 mA, and has lased cw with up to 1720 W output at 3.1 &mgr;m.

Journal Article↗