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Biomedical subjects

D Gilbert

Publications and source records attributed to D Gilbert.

At least 199 records · Page 11Linked to original sources
PubMedDate not supplied

Species differences in the generation of reactive oxygen species by microglia.

Although a variety of potential sources for reactive oxygen species (ROS) exist in the CNS, brain macrophages, i.e., the microglia, generate large quantities of these reactive species, particularly in response to injury or inflammatory signals. In order to understand how microglia contribute to changes in oxidative status of the CNS and how this might related to disease states, such as Alzheimer disease (AD), we have examined the regulation of superoxide anion and nitric oxide production from rodent and human microglia. Our results indicate that microglia from all species we have studied release superoxide anion, but produce significantly different amounts in response to the same activating agents. Species differences are also found in the ability to generate nitric oxide (NO). In particular, mouse microglia generate large quantities of NO when stimulated, but human and hamster microglia do not produce measurable amounts under the same stimulation conditions. These species differences are important to consider when modeling human disease processes from rodent studies.

Animals↗
PubMedDate not supplied

MRI assisted treatment planning for radiation therapy of the head and neck.

Improved visualization of head and neck tumors has been demonstrated with the use of magnetic resonance imaging (MRI). Using standard plastic radiation therapy immobilization casts and an MR positive surface marker system developed in this institution, we have utilized MRI as an adjunct to the simulation of complex radiation treatments for tumors of the head and neck. This technique includes an indirect display of field margins and/or isodose curves over selected MR images. The lack of induced artifact from the immobilization cast, improved delineation of tumor extension from normal anatomy and the ability to image in arbitrary planes without changing patient positioning favor the use of MR over CT for radiation therapy planning in the head and neck, while ensuring reproducibility of the treatment plan at subsequent therapy sessions.

Aged↗
PubMedDate not supplied

Interactions of the third component of human complement (C3) with tumour cells: evidence for presence of C3b acceptor sites and direct activation of C3 by tumour cells.

The interaction of C3 with different tumour cell lines was investigated. Our results indicated that nearly all the cell lines had C3b acceptors on their membranes. The binding of C3b was visualized by the detection of this protein on the cell surface with fluoresceinated anti-C3c serum. The involvement of proteases in the activation of C3 was demonstrated: complement-membrane fluorescence occurred in the presence of EDTA but was completely abolished with epsilon-aminocaproic acid. Experiments performed with purified C3 led to the conclusion that the protease activity might be the initial event for the activation of the alternative pathway by tumour cells.

Burkitt Lymphoma↗
PubMedDate not supplied

The MMPI as a predictor of outcome in low-back surgery.

Between 1965 and 1975, 103 low-back patients were rated preoperatively for general level of functioning, and each completed a Minnesota Multiphasic Personality Inventory (MMPI) test. Following surgery, patients were rated in terms of treatment effectiveness at 6 months and 1 year. The MMPI hypochondriasis and hysteria scales were moderately related to surgical success, as were the severity of initial restriction in the level of functioning and the number of operations performed during the study. However, the MMPI profiles were strikingly similar for all patients. Factors which were not predictive of surgical outcome included age, sex, duration of symptoms, number of back surgeries prior to entering this clinic, and the degree of pathologic condition discovered at operation. The failure to find a potent prediction scheme confirms that MMPI information must be used with considerable caution in treatment planning and only as an adjunct to other clinical and psychological data.

Adult↗
PubMedDate not supplied

Representing and analysing molecular and cellular function using the computer.

Determining the biological function of a myriad of genes, and understanding how they interact to yield a living cell, is the major challenge of the post genome-sequencing era. The complexity of biological systems is such that this cannot be envisaged without the help of powerful computer systems capable of representing and analysing the intricate networks of physical and functional interactions between the different cellular components. In this review we try to provide the reader with an appreciation of where we stand in this regard. We discuss some of the inherent problems in describing the different facets of biological function, give an overview of how information on function is currently represented in the major biological databases, and describe different systems for organising and categorising the functions of gene products. In a second part, we present a new general data model, currently under development, which describes information on molecular function and cellular processes in a rigorous manner. The model is capable of representing a large variety of biochemical processes, including metabolic pathways, regulation of gene expression and signal transduction. It also incorporates taxonomies for categorising molecular entities, interactions and processes, and it offers means of viewing the information at different levels of resolution, and dealing with incomplete knowledge. The data model has been implemented in the database on protein function and cellular processes 'aMAZE' (http://www.ebi.ac.uk/research/pfbp/), which presently covers metabolic pathways and their regulation. Several tools for querying, displaying, and performing analyses on such pathways are briefly described in order to illustrate the practical applications enabled by the model.

Cell Physiological Phenomena↗
PubMedDate not supplied

African-American women who always use condoms: attitudes, knowledge about AIDS, and sexual behavior.

Given the alarming increase in the incidence of sexually transmitted diseases (STDs), including AIDS, among African-American women, it is apparent that many people are engaging in sexual intercourse without using condoms. The current study examined the interrelationships among attitudes about condom use, knowledge about AIDS, sexual behavior, and drug use among 121 adult African-American women who varied in their intentions to use condoms: 21 (17%) were classified as Steady Users, 75 (62%) did not use condoms but they had High Intentions to, while 25 (21%) did not use condoms and had Low Intentions to use them. Results indicate that the three groups did not differ in their overall knowledge about AIDS or their attitudes toward using condoms as contraceptives. Significant group differences were noted for other scales that assessed attitudes about condoms. Attitudes about the use of condoms were very similar for the Steady Users and the women in the High Intentions group. However, these two groups were significantly (p < .01) different in their belief that condoms are uncomfortable and interrupt sex. Women with Low Intentions to use condoms had significantly (p < .05) more intense angry reactions regarding the negotiation of condom use and significantly more negative attitudes about the use of condoms than women in the other groups. The three groups were not differentiated by drug use, previous treatment for STDs, or their perceived risk for being exposed to AIDS. The present study is cross-sectional in nature and future research using better methodology is needed to establish causal relationships.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Selective deficiencies in complement component : a family with hereditary C2 deficiency.

We report herein a new case of C2 deficiency in a patient with systemic lupus. The subject and one of her brothers, who shows no clinical manifestations, are hymozygous C2 deficient. All other family members are heterozygous for the C2 deficiency. Gene for C2 deficiency (C2d) was shown to be inherited with HLA-A9, B7/Bfs and HLA-A10, B27/Bfs haplotypes. This association has not previously been described.

Adolescent↗
PubMedDate not supplied

[Nutritional recommendations and risk of death from all causes].

This study evaluated the relationship between meeting the Nutrition Recommendations and mortality from all causes in a cohort of 1,623 men from the Quebec City area followed from 1985 to 1991. The usual dietary intake was assessed by a self-administered semi-quantitative food frequency questionnaire. Most participants did not meet the Nutrition Recommendations. During the follow-up 69 men died. The mortality was significantly lower among those who did not meet the recommendations for total fat (RR = 0.45, CI: 0.25-0.81) or for carbohydrates (RR = 0.49, CI: 0.26-0.92). This unexpected result could be attributable to an excessive alcohol intake or to dietary changes in the direction of the Nutrition Recommendations, made prior to the dietary assessment often because of illness. It would be interesting to continue the follow-up of this cohort to evaluate the long-term effect of a diet meeting the Nutrition Recommendations on mortality from all causes.

Aged↗
PubMedDate not supplied

[Secondary malignant tumors of the vestibulocochlear and facial nerves].

INTRODUCTION: Neuromas and meningiomas represent by far the most frequent tumors of the cerebellopontine cistern (respectively over 80% and over 10%). Secondary malignant tumors are exceptional. METHOD: Presentation of four cases of malignant tumors of the cerebellopontine cistern, either revealing or complicating a primary tumor: a bronchial cancer, a cancer of the kidney, a medulloblastoma and a lymphoma. Patients were studied in T2- and T1-weighted high-field MRI sequences before and after gadolinium injection. RESULTS: The four tumors were enhanced by gadolinium and shown to invade the internal auditory canal, including one bilateral involvement. In most cases, the tumors were slightly heterogeneous and had irregular margins. CONCLUSION: These observations suggest that other diagnoses than acoustic neuroma should be taken into account.

Adenocarcinoma↗
PubMedDate not supplied

Involving patients: lessons from PACE.

In the fourth part of our PACE series, based on the King's Fund Promoting Action on Clinical Effectiveness programme, the first article reviews the experiences of 16 PACE projects that offer tips for involving patients in programmes to implement evidence-based practice, quality initiatives and clinical governance arrangements. The second article provides a more detailed example of one project.

Evidence-Based Medicine↗