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Biomedical subjects

C J Atkins

Publications and source records attributed to C J Atkins.

At least 19 recordsLinked to original sources
PubMed2001

An expressed GNRP-like gene shares a bi-directional promoter with SF3A2 (SAP62) immediately upstream of AMH.

A region of homology, containing the contiguous SF3A2 (formerly called SAP62) and AMH genes, exists between human chromosome 19 (HSA19p) and mouse chromosome 10 (MMU10). In a previous study it was shown that SF3A2/Sf3a2 is very highly conserved between the two species and that AMH/Amh is somewhat less conserved although both human and mouse genes encode a protein (AMH) playing the same critical role during early male sex differentiation. The close association between SF3a2/Sf3a2 and AMH/Amh was thought to maintain open chromatin in the AMH/Amh promoter region, thus facilitating the necessary precise timing of AMH/Amh expression following that of SRY/Sry at the onset of testis differentiation. Further investigation of DNA upstream of Amh has revealed that there is another gene, in close association (about 400 bp) with Sf3a2, which has significant similarities to the N-terminus of a known guanine nucleotide releasing protein (GNRP) and consequently is provisionally named GNRPx/Gnrpx. The Gnrpx-Sf3a2-Amh (GSA) locus of the mouse (MMU10) is conserved in the human (HSA19p). Mapping the Sf3a2 transcription start site eventually led us to locate and characterize its promoter. We found that Sf3a2 and Gnrpx share a bi-directional promoter, with the latter being transcribed in an antisense direction. It has now been shown by RT-PCR analysis that both Sf3a2 and Gnrpx are widely expressed and therefore are likely to be 'housekeeping' genes. GNRPx/Gnrpx messenger RNA codes for a C-terminally truncated protein (149/164 aa), which contains an as yet uncharacterized domain common to GNRPs (and related proteins) and which may therefore act as a specific antagonist of a complete GNRP protein (>1200 aa) involved in the regulation of the GTPase (G-protein/Ras) cycle.

Amino Acid Sequence↗
PubMed1997

In vivo gene therapy of malignant tumours with heat shock protein-65 gene.

We have previously shown that ex vivo insertion of a gene encoding the mycobacterial heat shock protein-65 into tumour cells results in their inability to form tumours in mice. We report regression of highly malignant reticulum cell sarcomas (J774) after liposome-mediated gene transfer in vivo. Heat shock gene transfer resulted in tumour regression both in immunocompetent and immunodeficient SCID mice. Complete tumour eradication, however, was detected only in immunocompetent animals, confirming the role of T cells in tumour rejection. Treatment of tumour bearing mice with the heat shock gene-liposome complex resulted in the production of antibodies against the tumour cells, indicating an increase in the antigenicity of the tumour after gene transfer. These results suggest that the heat shock protein-65 gene could provide a novel approach for the treatment of established tumours.

Animals↗
PubMed1996

Expression of bcl-x during mouse B cell differentiation and following activation by various stimuli.

We have studied the expression of the novel anti-apoptotic protein bcl-x during mouse B cell differentiation and activation. We find that bcl-x is expressed throughout all stages of B cell differentiation in the bone marrow, and is only down-regulated in mature (sIgD+) B cells. Immature peripheral B cells express low levels of bcl-x even in adult animals, whereas mature resting B cells do not. Mature B cells re-express the protein following activation, achieving maximal levels after 36-48 h. The highest levels of bcl-x are observed with potent mitogenic stimuli (such as anti-CD40 + anti-Ig): B cells first express bcl-x in the G1 phase of the cell cycle and contain maximal levels in S phase. In addition, B cells from CBA/N mice, which do not proliferate when stimulated with anti-Ig, anti-CD40 or both, exhibited only low levels of the protein following culture with these stimuli. To investigate the functional significance of bcl-x in activated B cells, we tested their sensitivity to apoptosis induced by the Ca2+ ATPase inhibitor thapsigargin: B cell blasts activated with anti-CD40 and anti-Ig were resistant to this agent. The available data therefore suggest that bcl-x fulfils two roles in B cells: it promotes survival of immature B cells (which lack bcl-2) and secondly, it apparently plays an additional role in protecting activated mature B cells (perhaps those in germinal centers) from apoptotic stimuli.

Animals↗
PubMed1994

Properties of mouse CD40: cellular distribution of CD40 and B cell activation by monoclonal anti-mouse CD40 antibodies.

We describe here the derivation of a rat monoclonal antibody (mAb) against mouse CD40 (designated 3/23), which stains 45-50% of spleen cells of adult mice, approximately 90% of which are B cells. Interestingly, some 5-10% of both CD4+ and CD8+ T cells in the spleens of (some, but not all) adult, unimmunized mice are also CD40+, whereas CD40+ cells were not detectable in the thymus, even following collagenase digestion. Some 35-40% of lymphoid cells in the bone marrow of adult mice are CD40+ and virtually all of these are B220+, and hence of the B cell lineage: triple-color flow cytometry showed that CD40 is expressed at low levels on some 30% of pre-B cells, at intermediate levels on 80% of immature B cells and on essentially all mature B cells in the bone marrow. These results, therefore, suggest that in the mouse CD40 is expressed relatively late during the process of B cell differentiation. The mAb induced marked up-regulation of major histocompatibility complex class II molecules, CD23 and B7.2 antigens on mature B cells. It also stimulated modest levels of DNA synthesis in mature B cells by itself: this was markedly enhanced by suboptimal concentrations of mitogenic (but not non-mitogenic) anti-mu and anti-delta mAb, and moderately enhanced by co-stimulation with interleukin-4. Hypercross-linking of CD40 (using biotinylated mAb and avidin) also enhanced the proliferative response to anti-CD40.

Animals↗
PubMed1993

Relationship between self-monitoring of diet and exercise change and subsequent risk factor changes in children and adults.

Self-monitoring is often used in health behaviour change programs; but it is not known to what extent self-monitoring data are valid and useful in predicting changes in cardiovascular disease (CVD) risk. Subjects included 72 Anglo adults, 68 Anglo children, 80 Mexican-American adults and 94 Mexican-American children. Subjects were families with fifth and sixth grade children who participated in an 18-session family-based diet and exercise change program designed to reduce CVD risk. During the intervention, each participant self-monitored diet and aerobic physical activity. Families were measured at baseline, 3, 12, and 24 months. For adults, self-monitored changes in diet correlated with changes in body mass index, systolic blood pressure, total cholesterol and LDL 1 and 2 years later. Correlations between self-monitored diet and diet-related risk factor changes were not observed among children. Correlations between self-monitored exercise and subsequent risk factor changes were not observed among adults. For children, self monitored changes in aerobic physical activity correlated significantly with changes in VO2Max and HDL/LDL ratio 1 and 2 years later. Thus, this study provides some support for the predictive validity of diet self-monitoring in adults and exercise self-monitoring in children.

Adult↗
PubMed1993

Process variables as predictors of risk factor changes in a family health behavior change program.

The purpose of the present study was to determine the extent to which intervention process measures are useful in predicting changes in cardiovascular disease (CVD) risk factors among subjects exposed to interventions. Subjects were 99 adult and 105 children who participated in an 18 session, family-based diet and exercise change program. During the intervention, each participant self-monitored diet and exercise for 12 weeks. Additionally, attendance, session evaluation, confidence to achieve goals and goal achievement data were collected each week. The intervention was successful in changing diet, blood pressure and cholesterol levels, but did not produce significant changes in exercise or body mass index. Stepwise multiple regression analyses were conducted for each outcome variable at the 1 and 2 year follow-ups. Ethnicity and sex were first forced into each regression. None of the process measures consistently predicted multiple outcomes in adults and children. The pattern of results provides limited support for the hypothesis that intervention process variables such as attendance, adherence to self-monitoring, achievement of goals and attitude toward sessions partially mediate intervention effects. It is concluded that process measures should be collected in health behavior change programs so that process-outcome relationships can be further explored.

Adolescent↗
PubMed1993

Analyses of DNA content of living spermatozoa using flow cytometry techniques.

A two-dimensional fluorescence analysis of spermatozoa stained with Hoechst 33342 was carried out using an Epics V flow cytometer. This analysis involved the measurement of fluorescence both in the conventional manner at 90 degrees and at a narrow forward angle (nominally 0 degree) to the direction of the interrogating laser beam. The arrangement provided an optical means of distinguishing the orientation of flattened particles passing through the interrogation system and enabled the verification and reinterpretation of one-dimensional (90 degree) fluorescence histogram data obtained previously. We now consider that the distinction between live and dead spermatozoa was over simplified and that the observed differences are due partly to an artefact of orientation. It has been confirmed that our earlier use of the low fluorescence peak, consisting of (bull, rabbit, sheep and pig) spermatozoa passing through the interrogation point obliquely to both detectors, as criterion for sorting X- from Y-bearing spermatozoa, is more practical than the use of a very much smaller subpopulation, based on limits imposed by selecting only spermatozoa accurately orientated with their narrow edges to one detector, while measurement of total fluorescence (DNA content) was made simultaneously from a broad face by the other detector. We report marked differences in the rate of staining and in attainment of a staining equilibrium between spermatozoa from different animals or from different ejaculates collected on the same or different days from the same animal. This variation introduces an element of subjectivity into the use of flow cytometry for sorting X- and Y-spermatozoa.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Reduction of secondary smoke exposure in asthmatic children: parent counseling.

Epidemiological evidence shows that children's exposure to secondhand tobacco smoke increases their risk of respiratory illness. This study evaluated five families and their asthmatic children (aged 5-14 years) in an outpatient counseling program for reducing the children's exposure to passive smoking. Intervention included biweekly counseling/instructions for parents to limit their children's tobacco exposure. A multiple-baseline, quasiexperimental design was used for self-reported measures of the children's smoke exposure and the parent's smoking frequency. Counseling was associated with smoke exposure reduction of 40-80% from baseline for each of 5 children, with most improvements sustained during follow-up. This study provides support for the development of tobacco exposure prevention programs for children with pulmonary disease.

Adolescent↗
PubMed1992

An electronic method for measuring joint tenderness in rheumatoid arthritis.

OBJECTIVE: To test the precision of a new electronic method for measuring joint tenderness. METHOD: Joint tenderness was measured in 30 patients with rheumatoid arthritis, using an electronic dolorimeter. The results were compared with joint tenderness counts, which were made according to the American Rheumatism Association (ARA) methods. RESULTS: The intra-observer variability using the electronic method was significantly decreased compared with the conventional ARA joint tenderness counts. CONCLUSION: The electronic method is more efficient for use in clinical trials than is the conventional ARA joint tenderness count.

Arthritis, Rheumatoid↗
PubMed1991

BEACHES: an observational system for assessing children's eating and physical activity behaviors and associated events.

An integrated system for coding direct observations of children's dietary and physical activity behaviors was developed. Associated environmental events were also coded, including physical location, antecedents, and consequences. To assess the instrument's reliability and validity, 42 children, aged 4 to 8 years, were observed for 8 consecutive weeks at home and at school. Results indicated that four 60-min observations at home produced relatively stable estimates for most of the 10 dimensions. Interobserver reliabilities during live and videotaped observations were high, with the exception of "consequences" categories that occurred in less than 1% of observed intervals. Evidence of validity was provided by findings that antecedents were associated with respective dietary and physical activity behaviors. The five physical activity categories were validated by heartrate monitoring in a second study. The Behaviors of Eating and Activity for Children's Health Evaluation System is appropriate for studying influences on diet and physical activity in children in a variety of settings.

Behavior Therapy↗
PubMed1990

Attendance at health promotion programs: baseline predictors and program outcomes.

As part of a family cardiovascular health promotion project, 111 Mexican-American and 95 Anglo-American families with fifth- or sixth-grade children were assigned to either a primary prevention program involving 18 sessions or to a control condition. This article evaluates predictors of attendance at the year long sequence of sessions in the intervention group. In addition it considers the relationship between attendance and program outcomes. Low baseline scores on physical activity and cardiovascular fitness measures were associated with higher attendance for both children and adults. High initial health knowledge and self-motivation were also associated with attendance. Multiple regression analysis showed that adult attendance was significantly predicted by a model including completion of a three-day food record, low exercise, higher socioeconomic status, family adaptability, and self-motivation. Attendance was correlated with greater knowledge gains and larger reductions in blood pressure. The results indicate that motivated families who are in greater need of conditioning attended more sessions in a health promotion program.

Adult↗
PubMed1989

The well-year of life as a basis for patient decision-making.

Medical decision-making requires the integration on costs, risks, and benefits of treatment. Clinical side effects and benefits are typically expressed in terms of symptoms and clinical states of diseases. Integrating probabilistic information about different categories is often difficult from both the patient's and the clinician's perspectives. We offer a General Health Policy Model that expresses the benefits and side effects of treatment within a common unit. The model takes into consideration mortality, function (morbidity), and preference for health states. In addition, the model uses probability information to describe the prognosis or likelihood of transition among states over the course of time. The output of the model is a well-year which is defined as the equivalent of a completely well-year of life. The well-year is a comprehensive expression of benefits minus side effects that may be useful for individual patient decision-making.

Activities of Daily Living↗
PubMed1989

Familial similarities of changes in cognitive, behavioral, and physiological variables in a cardiovascular health promotion program.

A number of studies have demonstrated that physiological and behavioral cardiovascular disease (CVD) risk factors aggregate within families. This fact, and the potential mediating role that the family plays in behavior change, have led to the development of family-based CVD risk reduction programs, including the San Diego Family Health Project. The aggregation of behavioral, physiological, and cognitive changes within families was assessed during a 1-year intervention. We found evidence of modest but significant aggregation of change. There was more aggregation of change in behavioral variables than in physiological or cognitive variables. More significant correlations were found among 3-day food record measures than among 24-hour recall dietary measures, suggesting an influence of assessment method. Aggregation of change within families was stronger within generations than across generations. These data point to the importance of involving all age groups in health promotion programs.

Adult↗
PubMed1989

Anti-Au: the antithetical antibody to anti-Au.

Anti-Au, the first example of the antithetical antibody to anti-Au, was identified in the serum of a blood donor who had been transfused 16 years previously. Au has a gene frequency of 0.4326 in an American black population and 0.2994 in a southern English donor population. The expression of Au is suppressed by In(Lu). XS2 also suppresses Auberger antigen expression.

Black People↗
PubMed1989

A family approach to cardiovascular risk reduction: results from the San Diego Family Health Project.

The effectiveness of a family-based cardiovascular disease risk reduction intervention was evaluated in two ethnic groups. Participants were 206 healthy, volunteer low-to-middle-income Mexican-American and non-Hispanic white (Anglo-American) families (623 individuals), each with a fifth or a sixth-grade child. Families were recruited through elementary schools. Half of the families were randomized to a year-long educational intervention designed to decrease the whole family's intake of high salt, high fat foods, and to increase their regular physical activity. Eighty-nine percent of the enrolled families were measured at the 24-month follow-up. Both Mexican- and Anglo-American families in the experimental groups gained significantly more knowledge of the skills required to change dietary and exercise habits than did those in the control groups. Experimental families in both ethnic groups reported improved eating habits on a food frequency index. Anglo families reported lower total fat and sodium intake. There were no significant group differences in reported physical activity or in tested cardiovascular fitness levels. Significant differences for Anglo-American experimental vs. control adult subjects were found for LDL cholesterol. Significant intervention-control differences ranging from 2.2 to 3.4 mmHg systolic and/or diastolic blood pressure were found in all subgroups. Direct observation of diet and physical activity behaviors in a structured environment suggested generalization of behavior changes. There was evidence that behavior change persisted one year beyond the completion of the intervention program. It is concluded that involvement of families utilizing school based resources is feasible and effective. Future studies should focus on the most cost-effective methods of family involvement, and the potential for additive effects when family strategies are combined with other school health education programs.

Adolescent↗