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Biomedical subjects

A Sanders

Publications and source records attributed to A Sanders.

At least 19 recordsLinked to original sources
PubMed2000

Precise measurement of the J = 1 to J = 2 fine structure interval in the 2( 3)P state of helium

We measure the J = 1 to J = 2 fine structure interval in the ( 3)2P state of helium to be 2 291 175.9(1.0) kHz. We use laser excitation of an atomic beam along with an integrated electro-optic modulator technique to obtain this result. The result is consistent (2.9+/-3.2 kHz) with what could be considered an earlier version of this experiment but is not in good agreement ( 20+/-5 kHz and 22+/-8 kHz) with the two other precision determinations of this interval. The current theoretical prediction lies between and overlaps the experiments.

Journal Article↗
PubMed2000

Life-cycle stage morphology of Psoroptes mange mites.

Detailed life-cycle stage descriptions for the ectoparasitic mite Psoroptes ovis (Hering) (Acari: Psoroptidae) from rabbit hosts (syn. Psoroptes cuniculi) are presented. The results resolve a number of contradictions in the literature relating to the recognition of the life cycle stages of these mites. This study supports the view that there are two distinct male nymphal stages, both lacking dorsoposterior tubercles. The male tritonymph is significantly larger than the protonymph and has five pairs of metapodosomal setae rather than three. In addition, male tritonymphs have two pairs of cuticular pits on the central metapodosoma rather than the single pair of the protonymph. The results also show that the female protonymph can be distinguished from the male nymphal stages and the female tritonymph. Both female nymphal stages possess dorsoposterior tubercles, but the protonymph is significantly smaller than the tritonymph. In addition, the protonymph possesses three pairs of metapodosomal setae rather than five, one pair of cuticular pits rather than two, and a pulvillus on leg IV which is absent in the female tritonymph. The presence of dorsoposterior tubercles enables the female nymphs to be distinguished easily from the males. By contrast, distinguishing between the nymphal stages of the same sex relies on the identification of both the number of metapodosomal setae and cuticular pits. These descriptions are used to produce a key, which allows the various stages of both sexes to be distinguished.

Animals↗
PubMed1999

Interactions between American Indian ethnicity and health care.

Interventions in health care must be sensitive to the part that culture plays in treatment, recovery and healing of the American Indian patient. Cultural factors play an important part in how the family participates and copes with the intervention program. Interpreting communication and behavior from the perspective of the family's culture contributes to positive family-professional interaction. This paper addresses the most important cultural factors impinging on positive health care for American Indian families and addresses a process for assessment of cultural conflicts which may prevent positive outcomes in the delivery of health care to this population. In addition, this paper offers strategies throughout that can be used by health care professionals to assure culturally sensitive service delivery to American Indians.

Acculturation↗
PubMed1998

Effects of liposome-encapsulated drugs on macrophages: comparative activity of the diamidine 4',6-diamidino-2-phenylindole and the phenanthridinium salts ethidium bromide and propidium iodide.

Liposomes can be used for the intracellular delivery of drugs into macrophages. Previously, we developed a liposome-mediated macrophage 'suicide' technique based on the intraphagocytic accumulation of the liposomally delivered bisphosphonate clodronate. Later we found that the diamidine propamidine is even more effective in this approach. In the present study it is shown that liposome-encapsulated 4', 6-diamidino-2-phenylindole (L-DAPI), another well known DNA-binding diamidine, is the most effective drug in killing liver macrophages (Kupffer cells), when intravenously administered in rat. Compared to liposome-encapsulated propamidine (L-propamidine) it showed about 10-fold more activity on a molar basis. Furthermore, L-DAPI was found to induce cell death by inducing apoptosis. The structurally strongly related phenanthridinium salts ethidium bromide (EB) and propidium iodide (PI) exert marked differences in their efficacy. Whereas liposome-encapsulated PI (L-PI) was about 5 times more active in killing macrophages than L-propamidine, liposome-encapsulated EB (L-EB) showed a strongly reduced activity (10 times less than L-PI). As is shown here, PI remains mainly encapsulated in liposomes, while substantial amounts of EB leak out of liposomes. This may very well explain the differences in in vivo activity between L-EB and L-PI.

Animals↗
PubMed1998

The role of macrophages in the induction and regulation of immunity elicited by exogenous antigens.

Different delivery vehicles may target to different antigen presenting cells (APC) because of their composition, size and/or physical properties. In this study, we examined the priming of cytotoxic T lymphocyte (CTL) responses to a soluble exogenous protein in vivo, using various delivery vehicles. In addition, we determined the role of macrophages as APC in vivo for each of these delivery vehicles by comparing the induction of antigen-specific CTL and serum antibodies in normal and macrophage-depleted mice. Influenza A virus-derived virosomes, liposomes and monophosphoryl lipid A/squalene (MPLSQ) efficiently induced antigen-specific CTL as well as antibody responses, of which virosomes proved to be the most efficient inducers. In mice that were immunized with cell-associated antigen, strong CTL responses but no antigen-specific antibodies were detectable, while aluminium hydroxide and aluminium phosphate elicited antigen-specific antibodies but no CTL responses. Elimination of macrophages in vivo before immunization abrogated CTL responses induced with liposomes and MPL/SQ, but did not affect induction of antigen-specific CTL with virosomes or cell-associated antigen. Importantly, serum antibody levels were not altered after macrophage depletion, regardless of the delivery vehicle used, suggesting that in the absence of macrophages, other APC may phagocytose the exogenous antigens for major histocompatibility complex (MHC) class II processing and presentation. These results suggest that soluble exogenous antigens delivered in different carrier systems may be processed differently by different APC in vivo for MHC class I- or class II-restricted presentation.

Adjuvants, Immunologic↗
PubMed1998

Professionalism in emergency medicine. SAEM Ethics Committee. Society for Academic Emergency Medicine.

The Society for Academic Emergency Medicine (SAEM), with the support and participation of the American Board of Emergency Medicine (ABEM), the Council of Residency Directors (CORD), the American College of Emergency Physicians (ACEP), the Emergency Medicine Residents Association (EMRA), the American Academy of Emergency Medicine (AAEM), and the Association of Academic Chairs of Emergency Medicine (AACEM), initiated a project entitled Professionalism in Emergency Medicine. Its concepts were developed by the SAEM Ethics Committee, and are intended to describe proper behaviors and attitudes of the successful practitioner of emergency medicine. The behaviors described are not primarily scientific or technical, since those are defined by the core curriculum for residency training and are tested through certification examinations. This document identifies attitudes and behaviors that enhance trust by placing the patient's interest above other interests. This concept serves as the operative definition of professionalism. The purpose of this article is to clarify the professional attitudes and knowledge that are important to the emergency physician (EP). While no physician is likely to meet idealized standards, all EPs must meet basic standards while striving for the ideal. Awareness of these standards must begin early in the socialization process of emergency medical professionals. The standards must be integrated into residency training as well as the clinical practice of all EPs.

Attitude↗
PubMed1998

Gender and history of suicidality: are these factors related to U.S. college students' current suicidal thoughts, feelings, and actions?

Gender and history of suicidality (HS vs. NoHS) were related to current symptoms of depression, reasons for living, and reports of self-destructive and life-threatening behavior in a college student sample. Overall, college men reported engaging in more life-threatening and potentially suicidal behavior than college women on the Life Attitudes Schedule (LAS). No gender effects were obtained on the symptoms of depression and reasons for living measures. Results suggest that the LAS may be a particularly effective way to identify college students at risk for self-destructive and suicidal behavior. As expected, HS individuals were more depressed, had fewer reasons for living, and reported engaging in more current suicidal and life-threatening behavior than NoHS participants. However, gender and history of suicidality were found to interact. NoHS women reported avoiding a variety of injury-producing and health-diminishing behaviors that were common for all other groups of college students. Meanwhile, HS women endorsed fewer current reasons for living than did NoHS women, NoHS men, and NoHS men. These findings were interpreted both with regard to cultural and gender-specific expectations for the expression of self-destructive, suicidal, and life-threatening behavior. Implications for the prevention of college women's and men's suicidal behavior were also noted.

Adult↗