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Biomedical subjects

M Fleming

Publications and source records attributed to M Fleming.

12 recordsLinked to original sources
PubMed1992

A national model of faculty development in addiction medicine.

Increasing the number of faculty with expertise in addiction medicine is one of the challenges facing the medical community in the 1990s. To meet this challenge, the Society of Teachers of Family Medicine created a faculty development course to increase the expertise of family practice faculty involved in teaching residents. The authors describe the development, implementation, and consequences of the five-day intensive course that was taught to 165 participants at ten sites in 1990. The participants' self-reporting before and three months after the course showed significant increases in the numbers of participants who taught addiction medicine in eight of 11 clinical situations. The authors conclude that the course represents a model of faculty development in addiction medicine that is applicable to other specialties and health professions.

Evaluation Studies as Topic↗
PubMed1991

Different epitope structures select distinct mutant forms of an antibody variable region for expression during the immune response.

Antibody variable (V) regions that initially differ from one another by only single amino acid residues at VH-D and D-JH segment junctions (termed canonical V regions) can be elicited in strain A/J mice by three different haptens. Among such V regions an amino acid substitution due to somatic mutation is recurrently observed at VH CDR2 position 58, regardless of which of these haptens is used for immunization. This substitution confers upon a canonical V region a generic increase in affinity for all the haptens. Conversely, the type of amino acid substitution at VH position 59 resulting from somatic mutation that is recurrently observed among such V regions changes with the eliciting hapten, in a manner that correlates directly with the cognate affinity increases (or decreases) for hapten conferred by the observed substitutions. This small subregion of VH CDR2 therefore plays a major role in determining both affinity and specificity for antigen. The data confirm that affinity for antigen is of pivotal importance in determining the degree of selection of different mutant forms of a V region. Moreover, during an immune response a sufficiently diverse mutant repertoire can be generated from a single canonical V region to allow adaptation to increase affinity for three different epitopes.

Amino Acid Sequence↗
PubMed1990

Isolation and characterization of abaecin, a major antibacterial response peptide in the honeybee (Apis mellifera).

Honeybee (Apis mellifera) are frequently exposed to and likely to be infected by plant-associated bacteria. We mimicked this process by injecting bees with live bacteria and isolated five induced antibacterial substances by comparative liquid chromatographic mapping of the hemolymph. Three of these antibiotics belong to a unique family of small (18 amino acids) peptides: the apidaecins [Casteels et al. (1989) EMBO J. 8, 2387-2391]. We have now characterized a fourth bee immune response peptide. The complete sequence was established by Edman degradation of the peptide and fragments thereof. It is 34 amino acids long and contains 10 proline residues. The amino-terminal half is related to the apidaecins; similar proline motifs are also present in the amino-terminal quarter of the much longer fly diptericins. The newly identified peptide's broad spectrum, lower specific activities against Gram-negative plant pathogens and its inability to inhibit bacterial growth at medium ionic strength are different from the apidaecins. Moreover, the highest observed specific activity was against an apidaecin-resistant Xanthomonas strain. In contrast to the immediate action of apidaecins, bactericidal activity is delayed. We propose the name 'abaecin' for this new antibacterial response peptide.

Amino Acid Sequence↗
PubMed1990

Internal sequence analysis of proteins separated on polyacrylamide gels at the submicrogram level: improved methods, applications and gene cloning strategies.

The fields of protein chemistry and molecular biology are currently merging for study of biologically relevant events and conditions. To obtain partial sequences of microamounts of protein, efficient integration of high resolution separation and sequencing technologies is required. We report here on improved methods that allow extensive internal sequencing of 10 to 20 picomoles protein recovered from one- or two-dimensional gels. Each step of the standard protocol of Aebersold et al. (Proc. Natl. Acad. Sci. USA 1987, 84, 6970-6974) and the required instrumentation were examined and specifically adapted for use with submicrogram amounts of protein. Optimizations of in situ microdigests and liquid chromatography were needed for improved peptide recovery. Subsequent automated sequencing required subpicomole analysis. New methods for S-alkylation of gel-separated proteins and accurate identification of tryptophan-containing peptides were introduced to insure overall higher efficiencies. The acquired internal sequences facilitated cloning of the genes and several strategies are discussed. Applying our method, several proteins of unknown structure were sequenced and successfully identified or cloned. Internal sequences of submicrogram protein amounts, recovered from a single two-dimensional gel of Escherichia coli total protein (120 micrograms), allowed unambiguous identification of the spots but pre-gel enrichment will be required for analysis of most (90-95%) other spots. Integration of comprehensive two-dimensional gel protein databases with methods and strategies outlined here could potentially be an abundant source of DNA probes and markers useful for guidance of the human genome sequencing project and for analysis of the emerging vast amounts of data.

Amino Acid Sequence↗
PubMed1989

Molecular analysis of original antigenic sin. I. Clonal selection, somatic mutation, and isotype switching during a memory B cell response.

To determine how the memory B cell population elicited to one epitope might be used in immune responses to other, structurally related epitopes, we explored the phenomenon of original antigenic sin. Strain A/J mice reproducibly respond to immunization with p-azophenylarsonate (Ars) by production of anti-Ars antibodies encoded predominantly by a single VH gene segment (VHIdCR). The structural analogue of Ars p-azophenylsulfonate (Sulf) fails alone to elicit such V regions, but can do so in A/J mice previously immunized with Ars, providing a means to specifically examine B cells capable of responding secondarily to a crossreactive antigen (i.e., memory cells). VHIdCR-expressing hybridomas were derived from the Ars-primed, Sulf-boosted original antigenic sin response of A/J mice at various times after Ars priming, and the properties of the antibodies they express and the structure of the genes encoding these antibodies were characterized. The data obtained support the following conclusions: (a) The Ars-induced memory B cell population capable of being crossreactively stimulated by Sulf is largely formed from a small fraction of all B cells participating in the anti-Ars primary response that express somatically mutated V regions; (b) the antibody repertoire and clonal composition of this population are stable over long periods of time; (c) memory B cells are capable of clonal expansion in the absence of a high rate of V gene somatic mutation; (d) the activation requirements for clonal selection of memory, versus naive B cells appear to differ; and (e) a major fraction of Ars-induced memory B cells express either IgM or IgG3 prior to and during the initial stages of the sin response.

Animals↗
PubMed1987

Quality of care for life-supported children who require prolonged mechanical ventilation at home.

Home care is now possible for ventilator-dependent children. It is crucial, however, to ensure that the children's conditions are medically stable and that their home care is carefully planned before they are discharged. The Ventilator-Dependent Discharge Program at Children's Memorial Hospital in Chicago uses a comprehensive, multidisciplinary approach to discharge planning. The program includes training for parent caregivers, organization of community resources, and arrangement for funding.

Chicago↗
PubMed1979

Draw-A-Person Test: implications for gender identification.

Human figure drawings were collected from 50 gender dysphoric adults and compared with the drawings of 84 adult evening-school students and college sophomores. The gender dysphoric males drew a person of the opposite sex first more often than the control group males (p less than 0.001). The gender dysphoric females drew a person of the opposite sex first more often than the control group females (p less than 0.05). Results are discussed in light of existing literature of the DAP and gender identity formation.

Adult↗
PubMed1976

Lesbian/feminist orientation among male-to-female transsexuals.

Autobiographical case studies of two male-to-female transsexuals reveal a pattern of strong female identity couples with lesbian sexual-affectional preference and feminist value orientation. For both informants there is evidence of social concern and activism from an early age, which led them to perceive their gender dilemmas in a political as well as personal way. This case material challenge the notion that transsexuals are necessarily "sexualy Uncle Toms" and demonstrated that male-to-female transsexuals (like genetic women) can achieve an affirmative lesbian identity; it suggests more generally that the development of sexual identity is an ongoing, lifelong process.

Adult↗
PubMed1975

Lowering of plasma cholesterol levels in free-living adolescent males; use of natural and synthetic polyunsaturated foods to provide balanced fat diets.

Two hundred and twenty-nine adolescent male pupils, attending two boarding schools, participated in a study, under free-living dietary conditions, designed to assess the effects on plasma lipids of altering only the type and not the amount of dietary fat. The students were monitored for 6 weeks on three different diets. During the first study period, dietary changes comprised substituting a polyunsaturated dried "filled" milk and products derived therefrom for conventional dairy products (diet A). The second dietary phase involved replacing all meat and dairy products with equivalent polyunsaturated ruminant fat products (diet B). The third period consisted of a control diet of conventional dairy and meat products. During both polyunsaturated diets a 14% reduction in plasma cholesterol was achieved compared with control levels. Low-density lipoprotein cholesterol was similarly suppressed. A greater decrease in plasma cholesterol of 19-21% was recorded in those pupils with initial cholesterol levels greater than 230 mg/dl. There was no significant difference in plasma triglycerides between diet A and the control diet whereas the triglyceride levels were 16.5% lower during diet B. The fall in plasma cholesterol coincided with an increase in plasma triglyceride linoleate from 8% to 19% of total triglyceride fatty acids. Dietary analysis of the pupils' diet indicated an increase in the ratio of polyunsaturates to saturates from 0.27 during the control period to 1.08 on the dried filled milk and 0.90 on the polyunsaturated ruminant fat products. A palatability survey showed that both the dried filled milk and the polyunsaturated ruminant fat products were as well accepted by the pupils as the conventional products. The results suggest that such products could, if introduced to the general population, play an important part in plasma cholesterol suppression in the hope that this would significantly reduce the incidence of coronary artery disease.

Adolescent↗