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Biomedical subjects

M C Davis

Publications and source records attributed to M C Davis.

At least 37 records · Page 2Linked to original sources
PubMed1996

Family behavior, adaptation, and treatment adherence of pediatric nephrology patients.

In this exploratory study we investigated the relationships among family behavior variables (e.g., family expressiveness), adaptive functioning skills, maladaptive behavior, and adherence to treatment in pediatric renal failure patients. The study included 22 pediatric outpatients with renal failure who had not yet received dialysis or transplantation (RF) and their parents, and 12 pediatric outpatients with kidney transplants (TX) and their parents. For the RF patients, significant correlations were found between some of their adaptive functioning skills and measures of their medication adherence, diet adherence, and clinic appointment adherence; however, for the TX patients significant correlations were found only between some of their adaptive functioning skills and measures of their medication adherence. For the RF patients only, some measures of their family behavior were significantly correlated with measures of their medication adherence and diet adherence. Additionally, some measures of the RF patients' family behavior were significantly related to their communication skills, socialization skills, overall adaptive functioning skills, and maladaptive behavior. For the TX patients, only their socialization skill level was significantly correlated with one measure of their family behavior. It is concluded that facilitation of adaptive and physical functioning among renal pediatric patients likely requires multidimensional training and/or counselling interventions with the children and their families, and that some of the content and/or emphasis of this training likely needs to differ for RF patients versus TX patients.

Adaptation, Psychological↗
PubMed1996

Do gender-relevant characteristics determine cardiovascular reactivity? Match versus mismatch of traits and situation.

This study tested the hypothesis that individuals exhibit heightened cardiovascular reactivity to a challenging task that is consistent vs. inconsistent with their gender-relevant attributes. In all, 82 men and women categorized as either highly instrumental or expressive engaged in an interpersonal task designed to tap instrumental or expressive characteristics. Results failed to confirm the hypothesis. Expressive individuals tended to exhibit larger increases in systolic blood pressure during an instrumental, relative to an expressive, interaction. Instrumental individuals tended to show larger increases in diastolic blood pressure during an expressive, relative to an instrumental, interaction. These results are consistent with the post hoc interpretation that environmental demands that fall outside of one's perceived areas of competency may result in exaggerated cardiovascular responsivity.

Adolescent↗
PubMed1995

Are job characteristics related to fibrinogen levels in middle-aged women?

This study examined whether employment status or job characteristics thought to be stressful were related to fibrinogen level in a sample of 161 healthy middle-aged women. Employed women had higher fibrinogen levels than did nonemployed women. Moreover, among employed women, those who perceived high levels of job stress or low support from their bosses had elevated fibrinogen, independent of menopausal status. Perception of low support from one's boss was related to higher fibrinogen levels only among premenopausal women or postmenopausal women who were not using hormone replacement therapy. These results are consistent with the notion that stress associated with some job characteristics influences levels of fibrinogen in women.

Adult↗
PubMed1995

Effects of nullisomic chromosome deficiencies on conjugation events in Tetrahymena thermophila: insufficiency of the parental macronucleus to direct postzygotic development.

Conjugation fails postzygotically after mating of Tetrahymena cells that have wild-type parental macronuclei but harbor noncomplementing nullisomic parental germline deficiencies. Failures begin shortly after formation of the new macronuclear precursor (anlage) and completion of the first step in elimination of the parental macronucleus (pycnosis). Conjugants fail to complete pair separation, to eliminate one new micronucleus, and to amplify anlage DNA, and they eventually die. Some deficiencies block resorption of the pycnotic parental macronucleus, but we find no evidence for its regeneration. Some deficiencies cause aberrant anlage DNA loss. Those that do not cause DNA loss are epistatic to those that do, indicating that normal anlage development requires the dependent function of at least two types of genes. The possibility that these genes are involved in developmentally regulated anlage DNA rearrangements is discussed. Each observed conjugation defect indicates insufficiency of the parental macronucleus to direct postzygotic development and can be explained by the deficiency of essential conjugation genes that are expressed from the anlage. The failure of nullisomic conjugants to complete pair separation indicates a requirement for gene products, expressed from the early anlage or its precursors, soon after anlage first differentiate.

Animals↗
PubMed1994

Identification of a novel polypeptide involved in the formation of DNA-containing vesicles during macronuclear development in Tetrahymena.

An abundant phosphoprotein with an apparent molecular mass of 65 kDa (p65) has been identified that is enriched in developing new macronuclei (or anlagen) isolated from the holotrichous ciliate, Tetrahymena thermophila. During early stages of macronuclear development, p65 is actively synthesized and deposited into young (4C) anlagen and is not found in micronuclei or parental macronuclei. p65 is not detected in older (8C) anlagen or in vegetatively growing or starved cells, and thus p65 is under stringent developmental control. In situ analyses, using polyclonal antibodies generated against p65, demonstrate that p65 undergoes a pronounced change in distribution during anlagen differentiation. Initially, anlagen are uniformly stained with these antibodies. However, following separation of conjugants, this staining pattern converts to one that is punctate and fragmented. As development proceeds, most, if not all, of these p65-based particles become peripherally located in anlagen and appear as well-defined vesicles surrounding a discrete central core of DNA of yet undetermined origin. This remarkable cytological distribution suggests an involvement of p65 in the elimination or processing of DNA during anlagen differentiation. If the above is correct, p65 provides the first inroad into the protein machinery involved in the well-known DNA rearrangements that characterize ciliate macronuclear development.

Animals↗
PubMed1993

Battling for national health reform.

At stake are the futures of all health care providers, including those that provide home care and hospice care. Who in Washington holds the ammunition to wage a winning war? Here is your insider's guide to the health reform leaders and their likely strategies. Be assured only that their battles will be intense.

Attitude to Health↗
PubMed1993

Understanding AIDS.

This discussion of AIDS' history, its growth, its victims, its costs, and the medical community's latest efforts to combat it is the cornerstone of this issue of CARING, featuring some of the myriad ways in which home care and hospice are responding to the AIDS crisis.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Managed competition: origins & implications.

It seems one can't read an article or watch a newspiece about health care reform without encountering the words managed competition. Where did the concept come from? What will it mean if it is implemented? This article discusses the basics of this plan.

Competitive Medical Plans↗
PubMed1992

Programmed nuclear death: apoptotic-like degradation of specific nuclei in conjugating Tetrahymena.

During conjugation in the ciliated protozoan Tetrahymena, new macronuclei differentiate from germinal zygotic micronuclei while parental (old) macronuclei are eliminated in two stages, condensation or pycnosis coincident with cessation of transcription followed by resorption. We show that pycnosis is accompanied by degradation of old macronuclear DNA into oligonucleosome-sized fragments, a hallmark of programmed cell death, or apoptosis, in a variety of eukaryotic systems. As expected, oligonucleosome formation does not occur in the new micro- and macronuclei, confirming the coordination of different developmental fates for different nuclei in a common cytoplasm. NULLI 3 conjugants have wild-type old macronuclei but lack chromosome 3 germinally and hence in the new macronucleus. In NULLI 3 conjugants, old macronuclear pycnosis and oligonucleosome fragmentation occur normally but the resorption step fails, and the pycnotic old macronucleus is retained, demonstrating that the two steps are genetically separable and thus distinct and implying that genes on chromosome 3 in the new macronucleus are required for the resorption step. Comparison of whole cell polypeptides synthesized during stages of macronuclear development in both wild-type and NULLI 3 crosses reveal similar profiles. However, a polypeptide (apparent M(r) of 53 kDa) synthesized during old macronuclear elimination is not observed in NULLI 3 conjugants; its role, if any, in elimination of the old macronucleus is unknown. The results show that the old macronucleus is selectively destroyed by a mechanism which is remarkably similar to apoptosis in other eukaryotes and that the zygotic genome is required for the resorption step.

Animals↗
PubMed1992

The client's right to self-determination.

Home care providers must integrate clients' best interests with their right to self-govern their plan of care. This balancing act poses myriad ethical dilemmas for caregivers.

Decision Making↗
PubMed1992

A joint Department of Defense/American Cancer Society health promotion project.

A joint venture expanding cancer control programs and services to overseas activities is described. A pilot project tests the feasibility of using the U.S.-based American Cancer Society programs and techniques at overseas sites. Volunteer-led service-specific organizations deliver services, and recruit and maintain volunteers. Primary focus is tobacco control programs. Periodic evaluations identify problems, successes, and on-going needs. Demonstrated benefits to the community include resources for public and professional education, public information, tobacco use cessation, nutrition education, and DoDDS (youth) programs. The major challenge to success and expansion is to establish and maintain a stable volunteer force.

American Cancer Society↗
PubMed1991

Does the gender relevance of the stressor influence sex differences in psychophysiological responses?

Sex differences in psychophysiological responses to stress may be important to understanding sex differences in risk for coronary heart disease. This investigation tested the hypothesis that the gender relevance of the stressor influences the extent of sex differences in cardiovascular, neuroendocrine, and lipid responses during stress. Participants performed two tasks that were described as masculine oriented, feminine oriented, or not gender relevant. Although these descriptions influenced the participants' perceptions of the tasks, they did not influence the extent of sex differences in physiological responses in a manner consistent with the study hypothesis. Future directions for research are discussed regarding sex differences in psychophysiological responses.

Achievement↗
PubMed1990

T-lymphocyte reactivity during the menstrual cycle in women.

Reactivity of blood lymphocytes to nonspecific mitogenic stimulation with phytohemagglutinin (PHA) was measured in nine healthy, regularly cycling women at three phases of their menstrual cycles corresponding to peak levels of estradiol (midfollicular phase), peak levels of progesterone (midluteal phase), and the lowest levels of both hormones (menstrual phase). Sampling points were verified by radioimmunoassay of estrogen, progesterone, luteinizing hormone, and follicle-stimulating hormone. There were significant increases in reactivity associated with an increasing concentration of PHA and with autologous plasma vs AB plasma. However, no differences were found in reactivity to PHA over the three menstrual cycle phases and correlational analyses indicated no relationship between counts and any of the hormones measured.

Adolescent↗
PubMed1990

Cigarette smoking and oral contraceptive use influence women's lipid, lipoprotein, and cardiovascular responses during stress.

Investigated the effects of behavioral stress and smoking cigarettes on the lipid, lipoprotein, neuroendocrine, and cardiovascular responses of female smokers who either used or did not use oral contraceptives (OC). Thirty-five healthy female smokers (20 of whom used OC) relaxed, smoked, or sham smoked and then prepared, delivered, and reviewed a speech presented in front of a video camera. Results show that behavioral stress increased total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol, triglyceride, and free fatty acid levels, with significant increases in cholesterol, LDL-C, and free fatty acids apparent only among women who smoked during the session. In addition, OC users exhibited larger increases in triglyceride and blood pressure responses during stress than did nonusers whether or not they smoked during the protocol. Possible physiological mechanisms for each of the effects, as well as implications of the findings for understanding epidemiological associations among OC use, smoking, and coronary heart disease in women are discussed.

Adolescent↗
PubMed1990

Influences of the normal menstrual cycle on physiologic functioning during behavioral stress.

The purpose of this study was to evaluate the influence of the normal menstrual cycle on lipoprotein, cardiovascular, and neuroendocrine stress responses. Fifteen normally-cycling, healthy women participated in a series of behavioral tasks during the menstrual, follicular, and luteal phases of their menstrual cycle. These women had established menstrual cycle regularity for the three months prior to enrollment in this study, were free from menstrual cycle disturbances, biochemically confirmed that they ovulated, and displayed appropriate patterns of reproductive hormone fluctuations during the study period. Heart rate, blood pressure, low density lipoprotein-cholesterol, and total cholesterol all demonstrated significant elevations from baseline levels during tasks. No differences in the magnitude of stress responses during the three menstrual cycle phases were noted for any physiological variable. We conclude that the hormonal fluctuations that occur in healthy, normally-cycling women during the menstrual cycle do not influence the stress responses that were investigated here. Significant influences of menstrual cycle phase previously reported in the literature, albeit not in a consistent direction, may have been due to the recruitment of women with menstrual cycle irregularities, and to the failure to adequately verify menstrual cycle phase.

Adult↗