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Biomedical subjects

B Dickinson

Publications and source records attributed to B Dickinson.

12 recordsLinked to original sources
PubMed2001

The multiple roles of major histocompatibility complex class-I-like molecules in mucosal immune function.

The human major histocompatibility complex (MHC) on chromosome 6 encodes three classical class-I genes: human leukocyte antigens (HLA) A, B, and C. These polymorphic genes encode a 43- to 45-kDa cell surface glycoprotein that, in association with the 12-kDa beta2-microglobulin molecule, functions in the presentation of nine amino acid peptides to the T-cell receptor of CD8-bearing T lymphocytes and killer inhibitory receptors on natural killer cells. In addition to these ubiquitously expressed, polymorphic proteins, the human genome also encodes several nonclassical MHC class-I-like, or class Ib, genes that, in general, encode nonpolymorphic molecules involved in various specific immunological functions. Many of these genes, including CD1, the neonatal Fc receptor for IgG, HLA-G, HLA-E, the MHC class-I chain-related gene A, and Hfe, are prominently displayed on epithelial cells, suggesting an important role in epithelial cell biology.

CD8 Antigens↗
PubMed2000

Expression of CD80 promoter in transgenic mice.

CD80 is a very potent co-stimulatory factor which is required for complete T-cell activation. Here, we use transgenic mice as a tool to map the promoter of the CD80 gene. We engineered three different CD80 promoter driven luciferase transgenes: -3084, -1073 and -215. With these transgenes, we have generated three groups of transgenic mice. Our results showed that the -3084 CD80 promoter/luciferase transgene was sufficient to confer tissue-specific expression of the CD80 gene. When the promoter sequence was deleted to -1073, the normal tissue-specific expression was lost. A brain-specific element was mapped between -1073 nt and -215 nt. This element caused up to ninefold higher expression of the CD80 promoter/luciferase in brain tissue of -1073 CD80 promoter/luciferase transgenic animals as compared to -3084 CD80 promoter/luciferase transgenic animals. In contrast to results with a cell culture system, little luciferase activity was detected in -215 CD80 promoter/luciferase transgenic animals.

Animals↗
PubMed2000

Weight loss is correlated with an improved lipoprotein profile in obese postmenopausal women.

BACKGROUND: Changes in plasma lipid and lipoprotein distributions that occur after menopause increase the risk of cardiovascular disease in women, especially in those who are overweight. OBJECTIVE: The purpose of this study was to evaluate the impact of a nine-month weight reduction program on plasma lipids, dietary intake and abdominal fat obesity. DESIGN: A partial crossover design was used to study a weight loss treatment consisting of Phentermine hydrochloride (Fastin, SmithKline Beecham Pharmaceuticals, Philadelphia, PA) therapy plus a low energy diet (5040 kJ/d). Forty-seven obese, postmenopausal Caucasian women (BMI of 30-38 kg/m2) were randomized into two groups, both of which received drug and diet treatment over six months. However, Group I started the intervention program three months later than Group II. Plasma total, HDL and LDL cholesterol and triacylglycerol were measured, body composition was assessed by anthropometry and dual energy x-ray absorptiometry, and food frequency records were collected at four timepoints. RESULTS: Over nine months, women in Group II reduced body weight (14.4%), lowered plasma concentrations of LDL cholesterol (14% to 26%) and triacylglycerol (15%) and raised plasma HDL cholesterol concentration (15%). These plasma lipid changes decreased the total cholesterol/HDL cholesterol ratio from 4.3 to 3.2. All subjects decreased abdominal fat measurements and energy and cholesterol intakes, as well as percentage of energy derived from total and saturated fat during the study. Most subjects also increased dietary fiber consumption. CONCLUSION: Both weight loss and diet modifications are associated with an improved plasma lipid profile in obese postmenopausal women.

Adult↗
PubMed1998

Scaling prison walls.

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Aspiration cytology of neoplastic and non-neoplastic ovarian cysts: is it accurate?

To evaluate the role of aspiration cytology in the distinction between neoplastic and non-neoplastic ovarian cysts, we examined the cytology of 81 aspirates from 80 women 14-67 years of age. We then correlated results with subsequent histology or the clinical follow-up. Aspiration were performed during laparoscopy (32 cases) or immediately after surgical removal of the tumors (49 cases). The cysts ranged in size from 1.0 to 43.0 cm. Papanicolaou-stained cytospin preparations of samples were evaluated, and the lesions were classified into non-neoplastic (68 cases), benign neoplasms (four cases), and malignant neoplasms (nine cases). Cytologic impressions were correlated with histologic findings in 74 cases and with the clinical follow-up in the remaining seven. Nine of the 12 (75%) cystadenocarcinomas, including two serous neoplasms of low malignant potential (LMP), were correctly diagnosed as malignant by cytology. There were no false-positive results. On the other hand, of the 26 benign neoplasms (19 cystadenomas and seven mature cystic teratomas), only four teratomas (15%) could be subclassified specifically. The remaining 68 aspirates were classified as non-neoplastic. Seventy-seven percent of all proven non-neoplastic cysts measured < 8.0 cm, whereas 77% of all benign and malignant neoplastic cysts were > 8.0 cm. The overall diagnostic accuracy was improved from 63% to 69% when cyst size was taken into consideration. In malignant cysts the diagnostic sensitivity was 75%, specificity 100%, and overall accuracy 96%. We arrived at the following conclusions: Aspiration cytology is an accurate predictor of malignancy in ovarian cystic lesions, but because the sensitivity of the technique is not high enough, one should not rely on aspiration cytology alone; The differential diagnosis between cystadenocarcinomas and tumors of low malignant potential cannot be made by cytology; Although it is difficult to distinguish between benign neoplasms and non-neoplastic benign cysts, diagnostic accuracy will improve when the size of the lesion is considered; Aspiration cytology can provide particularly useful information in young women with functional cysts of the ovary to avoid an unnecessary operation; Acellular cyst fluids should not be considered nondiagnostic because they represent benign cysts in the majority of cases; false-negative results of fine-needle aspiration of cystic ovarian lesions is usually due to low cellularity of the sample and secondary degenerative changes; negative fine-needle aspiration results should be followed clinically.

Adolescent↗
PubMed1994

VQLM: a Visual Query Language for Macromolecular structural databases.

Databases of macromolecular structures allow researchers to identify general principles of molecular behavior. They do this by providing a variety of data obtained under a number of different experimental conditions. Many new tools have been developed recently to aid in exploratory analysis of structural data. However, some queries of interest still require considerable manual filtering of data. In particular, studies attempting to make generalizations about complex arrangements of atoms or building blocks in macromolecular structures cannot be approached directly with existing tools. Such studies are frequently carried out on only a few structures or else require a labor-intensive process. To address this problem, we have developed a visual language, VQLM (Visual Query Language for Macromolecules). A query is formulated in this language by drawing an abstract picture of substructures to be searched for in the database and specifying constraints on the objects in them. To illustrate the usefulness of our language, we show how to encode a number of queries that were found scientifically interesting in the published literature in molecular biology. VQLM relies on VQL, a new database language, as its underlying engine for database retrieval and computation. We believe that VQLM will make macromolecular structural data more accessible to scientists, enabling faster and deeper data analysis.

Animals↗
PubMed1990

Alprazolam use and dependence. A retrospective analysis of 30 cases of withdrawal.

From 1986 to 1989, the Chemical Dependency Recovery Program at Kaiser Permanente Hospital, Fontana, California, admitted an increasing number of patients for alprazolam dependence. Severe withdrawal reactions and adverse consequences with use were reported in the literature. In this review of 30 cases of alprazolam dependence and subsequent withdrawal, there was a statistically significant increase in the number of patient hospital days, the subjective symptoms, and staff time spent with patients compared with those in alcoholic controls. Most patients with diagnosed alprazolam dependence used doses in the range recommended by the package information at the time of admission. Patients with low preadmission doses of 1 mg or less per day showed notable withdrawal symptoms. The average duration of use was 29.9 months, considerably longer than suggested effective ranges. Most patients (28) had a chemical dependence history before being placed on alprazolam therapy; 24 had a positive family history of chemical dependence; and 24 had previous or current psychiatric care.

Adult↗
PubMedDate not supplied

A novel stimulus, oncogene, induces expression of CD80 (B7-1) gene.

CD80, a cell surface molecule found on antigen-presenting cells which particpates in costimulatory signaling, is frequently detected on transformed and tumor cells. We examined the effect of transformation by v-myc, k-ras, and SV40 T antigen oncogenes on the expression of a CD80 promoter/luciferase gene as well as the endogenous CD80 promoter gene in murine fibroblast cell lines. All three transformed cell lines were tumorigenic in nude mice, however expression of the CD80/luciferase transgene or endogenous CD80 was detected only in the v-myc and k-ras transformed cell lines. In both cell lines, CD80 expression was first detected more than 30 passages after transformation. Therefore, induction of CD80 expression was a late event following transformation and was not essential for the establishment of the transformed phenotype.

Animals↗