Search PubMed⌕ Search

Biomedical subjects

A Robinson

Publications and source records attributed to A Robinson.

At least 73 records · Page 4Linked to original sources
PubMed2001

How patients with atrial fibrillation value different health outcomes: a standard gamble study.

BACKGROUND AND PURPOSE: The assessment of any health care intervention should consider both risks and benefits and take patients' preferences about these into account. The study reported in this paper aimed to elicit patient valuations of health states relevant to assessment of the prevention of stroke by warfarin anticoagulation therapy for patients with atrial fibrillation. METHODS: A sample of patients over the age of 60 years with atrial fibrillation from three family practices in North-East England was interviewed. Their health state values were elicited using the standard gamble method for general practitioner (GP)-managed warfarin treatment, hospital-managed warfarin treatment, major bleed, mild stroke and severe stroke. RESULTS: Of 180 patients, 69 (38%) agreed to participate, of whom 57 (83%) completed interviews. Median (mean) utility values were for GP-managed warfarin treatment 0.986 (0.948), hospital-managed warfarin treatment 0.984 (0.941), major bleed 0.880 (0.841), mild stroke 0.675 (0.641) and severe stroke 0 (0.189). There was wide variation in values between patients and the distributions were highly skewed. CONCLUSIONS: The results are of value in applying decision analysis to groups of patients. They should be used with caution in reaching decisions about appropriate treatment for individual patients, but may provide a starting point for necessary further exploration of those patients' individual preferences.

Anticoagulants↗
PubMed2001

Brush biopsy for detection of nasopharyngeal cancer.

The technique described above for sampling the nasopharynx requires minimal equipment, instruction, and expertise and causes minimal morbidity. Hence, it may be a valuable tool in a widespread screening program for a far too common and debilitating cancer in certain parts of the world.

Biopsy↗
PubMed2001

Ethnicity and end-of-life care: the use of feeding tubes.

BACKGROUND: Blacks utilize many health care services at lower rates than do Whites. However, in end-of-life care, the situation is frequently reversed, with Blacks using life-sustaining interventions at higher rates than do Whites. We investigated the use of feeding tubes in very severely cognitively impaired nursing-home residents, and examined the findings in light of previous studies on the role of ethnicity in end-of-life decision making. DESIGN AND METHODS: We performed a descriptive, cross-sectional population-based study of residents in Kansas nursing homes from January 1994 through June 1998, using Minimum Data Set reports. A total of 4,920 nursing home residents (4,691 White and 229 Black) with very severe and irreversible cognitive impairment comprised the study population. Factors associated with tube use were examined using bivariate and logistic regression tests. RESULTS: Feeding tube use was strongly associated with swallowing difficulties, Black race, urban location of nursing home, stroke, and absence of dementia in multivariate analysis. Feeding tubes were used in 10.1% of White subjects and in 38.9% of Black subjects for an overall rate of 11.5%. Feeding tube use was greater (P<.001) among Black subjects in all demographic and clinical sub-populations examined. CONCLUSIONS: Feeding tube use is significantly more common in Blacks than in Whites. These findings are consistent with published studies of Black-White differences in preferences for medical treatment at the end of life. Future research efforts should examine end-of-life decision making processes directly. Qualitative methods may be useful in generating new hypotheses regarding the role of ethnicity in these decisions.

Black or African American↗
PubMed2000

The platelet integrin alpha IIbbeta 3 has an endogenous thiol isomerase activity.

Integrins are cysteine-rich heterodimeric cell-surface adhesion molecules that alter their affinity for ligands in response to cellular activation. The molecular mechanisms involved in this activation of integrins are not understood. Treatment with the thiol-reducing agent, dithiothreitol, can induce an activation-like state in many integrins suggesting that cysteine-cysteine dithiol bonds are important for the receptor's tertiary structure and may be involved in activation-induced conformational changes. Here we demonstrate that the platelet-specific integrin, alpha(IIb)beta(3), contains an endogenous thiol isomerase activity, predicted from the presence of the tetrapeptide motif, CXXC, in each of the cysteine-rich repeats of the beta(3) polypeptide. This motif comprises the active site in enzymes involved in disulfide exchange reactions, including protein-disulfide isomerase (EC ) and thioredoxin. Intrinsic thiol isomerase activity is also observed in the related integrin, alpha(v)beta(3), which shares a common beta-subunit. Thiol isomerase activity within alpha(IIb)beta(3) is time-dependent and saturable, and is inhibited by the protein-disulfide isomerase inhibitor, bacitracin. Furthermore, this activity is calcium-sensitive and is regulated in the EDTA-stabilized conformation of the integrin. This novel demonstration of an enzymatic activity associated with an integrin subunit suggests that altered thiol bonding within the integrin or its substrates may be locally modified during alpha(IIb)beta(3) activation.

Amino Acid Sequence↗
PubMed2000

Accessing and distributing EMBL data using CORBA (common object request broker architecture).

BACKGROUND: The EMBL Nucleotide Sequence Database is a comprehensive database of DNA and RNA sequences and related information traditionally made available in flat-file format. Queries through tools such as SRS (Sequence Retrieval System) also return data in flat-file format. Flat files have a number of shortcomings, however, and the resources therefore currently lack a flexible environment to meet individual researchers' needs. The Object Management Group's common object request broker architecture (CORBA) is an industry standard that provides platform-independent programming interfaces and models for portable distributed object-oriented computing applications. Its independence from programming languages, computing platforms and network protocols makes it attractive for developing new applications for querying and distributing biological data. RESULTS: A CORBA infrastructure developed by EMBL-EBI provides an efficient means of accessing and distributing EMBL data. The EMBL object model is defined such that it provides a basis for specifying interfaces in interface definition language (IDL) and thus for developing the CORBA servers. The mapping from the object model to the relational schema in the underlying Oracle database uses the facilities provided by PersistenceTM, an object/relational tool. The techniques of developing loaders and 'live object caching' with persistent objects achieve a smart live object cache where objects are created on demand. The objects are managed by an evictor pattern mechanism. CONCLUSIONS: The CORBA interfaces to the EMBL database address some of the problems of traditional flat-file formats and provide an efficient means for accessing and distributing EMBL data. CORBA also provides a flexible environment for users to develop their applications by building clients to our CORBA servers, which can be integrated into existing systems.

Computational Biology↗
PubMed2000

Use of a Rush pin to repair fractures of the distal femur in cats.

Nine fractures of the distal femur in eight cats were repaired by using a 2.4 mm Rush pin as an intramedullary nail, placed between the condyles via a lateral or medial parapatellar approach to the stifle joint. In all cases the fractures were reduced and stabilised accurately with good postoperative results.

Animals↗
PubMed2000

Decision analysis and guidelines for anticoagulant therapy to prevent stroke in patients with atrial fibrillation.

BACKGROUND: Clinical guidelines are needed on whether or not to use anticoagulant therapy to prevent stroke in patients with non-valvular atrial fibrillation. We did a Markov decision analysis to model decision-making with regard to warfarin treatment in patients with atrial fibrillation, and used the model to develop evaluative guidelines. METHODS: The decision analysis involved a systematic literature review supplemented by patients' estimates of the quality of life associated with different states of health, secondary analysis of stroke-registry data, and estimation of service costs; it also incorporated a sensitivity analysis. The derived guidelines were subsequently applied to a cohort of patients with atrial fibrillation. FINDINGS: We constructed decision tables for 12 age and sex groups. For most risk combinations, warfarin treatment would have decreased health-care costs and increased quality-of-life years, although the clinical decision was sensitive to patients' preferences and to the estimate of warfarin's effectiveness. 97% of women with atrial fibrillation older than 75 years, and 69% aged 65-74 would have been recommended for treatment; for men, the corresponding figures would have been 75% and 53%. With the upper quartile for the loss of quality of life associated with being on warfarin treatment (1.00), all but two of the 116 patients without contraindications would have been treated, whereas with the lower quartile (0.92), only 27 of 116 would have been treated. INTERPRETATION: Decision analysis is useful in the incorporation of complex probabilistic data into informed decision-making, the identification of factors influencing such decisions, and the subsequent development of evaluative guidelines.

Aged↗
PubMed2000

Analysis of muscle creatine kinase regulatory elements in recombinant adenoviral vectors.

Adenoviral gene transfer holds promise for gene therapy, but effective transduction of a large and distributed tissue such as muscle will almost certainly require systemic delivery. In this context, the use of muscle-specific regulatory elements such as the muscle creatine kinase (MCK) promoter and enhancer will avoid potentially harmful ectopic expression of transgenes. We describe here the development and testing of adenoviral vectors containing small, striated muscle-specific, highly active MCK expression cassettes. One of these regulatory elements (CK6) is less than 600 bp in length and is 12% as active as the CMV promoter/enhancer in muscle. A recombinant adenoviral vector containing this regulatory element retains very high muscle specificity, expressing 600-fold higher levels of transgene in muscle than in liver. Muscle-specific regulatory elements may also increase persistence of transduced muscle cells. Adenoviral transduction of dendritic cells has been shown to stimulate cytotoxic T-lymphocyte (CTL) responses directed against transgene epitopes. We show that human dendritic cells infected in vitro with MCK-containing adenoviruses do not express significant levels of transgene. Furthermore, while adenoviral vectors containing nonspecific promoters are normally cleared from muscle tissue within 1 month, we show that MCK-containing vectors express significant levels of transgene 4 months after intramuscular injection.

Adenoviridae↗
PubMed2000

A study of the efficacy of topical and systemic therapy for the treatment of feline Microsporum canis infection.

Microsporum canis infection was induced in 21 healthy SPF-derived cats. Once infection was established (4 weeks after inoculation) the cats were divided into three equal groups housed in separate rooms and monitored for 16 weeks. During this time, group A cats received oral griseofulvin at approximately 50 mg/kg daily and were shampooed twice weekly with a product containing chlorhexidine and miconazole. Group B cats were treated with griseofulvin alone, and group C cats served as untreated controls. The cats were examined on a weekly basis and the severity of lesions was scored semi-quantitatively. In addition, hair samples were collected from each cat on a weekly basis by the MacKenzie brush technique and by the sticky-tape method. A semi-quantitative scoring system was also used for the assessment of fungal (M canis) growth. Generally, significant differences in clinical scores were not seen between the groups although at weeks 3, 4 and 11 there was a significant difference (P< or =0.015) with cats in group A having significantly lower median scores than those in group C. Median times to clinical resolution (return of clinical scores to zero) in groups A, B and C were at treatment weeks 2, 9 and 12, respectively (P>0.05). Median times for mycological resolution (persistently negative culture results) for groups A, B and C were at treatment weeks 2, 9 and 12, respectively, for the MacKenzie brush technique and at weeks 4, 8 and 12 for the sticky-tape technique. For both these results, the groups differed significantly (P< or =0.001) and in both instances group A had significantly more rapid resolution than groups B or C. Median culture scores were significantly different between the three groups using one or both of the sampling techniques at week 2 through to week 12 of treatment with median scores for either group A alone, or groups A and B being significantly lower than group C (P< or =0.026). These results showed a benefit from the addition of twice-weekly chlorhexidine-miconazole shampooing to systemic griseofulvin therapy alone in the treatment of M canis infected cats.

Administration, Topical↗
PubMed2000

Survivors of childhood cancers: implications for obstetric anaesthesia.

Treatment of many childhood malignancies involves surgery, radiotherapy and chemotherapy. If the child survives, normal physical development can be impaired and abnormalities with anaesthetic implications may be present. We discuss two women with a range of problems who presented for obstetric anaesthesia, having survived childhood malignancies. Common features included anthracycline cardiotoxicity and short stature. Both patients received incremental spinal anaesthesia in order to titrate the dose of local anaesthetic required to produce an adequate block height and to minimize cardiovascular instability.

Adult↗
PubMed2000

Using (1)H magnetic resonance imaging and complementary analytical techniques to characterize developmental changes in the Zantedeschia Spreng. tuber.

Nuclear magnetic resonance imaging (MRI) and complementary analytical techniques were used to examine tissue structure and developmental changes occurring during active growth in the root tuber of ZANTEDESCHIA: Spreng. cv. Chianti, a commercially significant cut flower. Plants were observed during the period of leaf senescence and tuberization at the end of the first growth cycle of micropropagated plantlets and, following cool storage to break endodormancy, during development occurring after the replanting of ecodormant tubers. MRI distinguished two distinct regions within the tuber, and the differences in the binding state of water in the two regions were reflected in differences in tissue morphology and function. An abundance of free water was observed in tissue comprised of large parenchyma cells, at the base of the tuber. This tissue appeared to be involved in maintaining the viability of the plant during the period of dormancy, a function indicated primarily by increased metabolic activity in this tissue during dormancy, and reduced metabolic activity during periods of active growth. In contrast, water was more tightly bound in tissue comprised of small parenchyma cells. This tissue appeared to operate as a region for dynamic carbohydrate storage. The initial increase in the free water content of this tissue during the growth phase was linked to the mobilization of starch during canopy development. The subsequent decrease in free water in the remainder of the growth period was linked to the reaccumulation of starch while the tuber functioned as a sink for photosynthate prior to canopy senescence.

Carbohydrate Metabolism↗