Leucine/glutamic acid/lysine protein 1 is localized to subsets of myonuclei in bovine muscle fibers and satellite cells.

Skeletal muscle growth is accomplished chiefly through the actions of satellite cells, a heterogeneous population that includes the adult muscle stem cell. Located adjacent to a mature muscle fiber, satellite cells typically reside in a quiescent state. Little information exists detailing satellite cell regulation of reversible G(0). One member of the mitosin family of centromere proteins, LEK1 (leucine/glutamic acid/lysine protein 1), is present in the nucleus of nondividing mouse satellite cells. The objective of this study was to evaluate LEK1 as a marker of quiescent bovine satellite cells (BSC) in vitro and in vivo. The BSC were isolated from young bull calves (< or =7 d) and cultured in vitro for up to 9 d before fixation and immunostaining for LEK1. Results demonstrated that all myogenic cells contain the protein, with immunostaining primarily within the nucleus and immediate perinuclear region. Immunocytochemical detection of LEK1 in cryosections of mature cows revealed that the protein was present in a fraction of satellite cells and muscle fiber nuclei. Approximately 20% of Pax7-expressing satellite cells contained LEK1. An equivalent percentage of myonuclei, as defined by nuclei within a dystrophin boundary, contained nuclear LEK1. To gain insight into the functional role of LEK1, BSC were transiently transfected with plasmids coding for putative dominant inhibitory LEK1 proteins [DeltaLEK1(991) and DeltaLEK1(911)] and evaluated for cell proliferation. Both forms of DeltaLEK1 inhibited (P < 0.05) BSC proliferation, as indicated by a decrease in Ki67 immunopositive cells. In C2C12 myoblasts, DeltaLEK1(911) inhibited (P < 0.05) myoblast determination protein 1 (MyoD)-directed muscle gene transcriptional activity; DeltaLEK1(991) had no effect on TnI-Luc transcription. By contrast, both DeltaLEK1 fusion proteins inhibited myogenin expression in BSC without disrupting myoblast fusion. These results provide evidence that LEK1 serves to coordinate proliferation and differentiation in myogenic cells. Coupling the immunostaining pattern and functional data, we propose that LEK1 may serve as a useful marker for satellite cells that are preparing to fuse into adjacent fibers as well as an indicator of recently added myonuclei.

Effect of ractopamine-hydrochloride on the fiber type distribution and shelf-life of six muscles of steers.

The goal of this study was to evaluate the effects of ractopamine-hydrochloride (RAC) supplementation on the myosin heavy chain isoform distribution and shelf-life properties of muscles from beef top round, knuckle, and loin. Thirty-four steer carcasses were selected from 4 separate slaughter groups. Within each slaughter group (3 groups, n = 8; 1 group, n = 10), steers were separated into pens (n = 8) and fed 0 or 200 mg x animal(-1) x d(-1) of RAC for the final 28 d of feeding. Seventy-two hours postmortem, the longissimus lumborum, semimembranosus (SM), adductor, gracilis, vastus lateralis (VL), and rectus femoris were removed from each carcass. A subsample of each muscle was collected for immunohistochemical analysis. Whole muscles were vacuum packaged and wet aged at 1 +/- 2 degrees C for 13 d before processing into steaks for a 5-d simulated retail display study. Daily, steaks were analyzed for reduction of nitric oxide metmyoglobin, lean color, fat color, and surface discoloration. Objective measures of metmyoglobin, oxymyoglobin, L*, a*, and b* values were recorded daily. Ractopamine significantly (P < 0.05) changed the fiber type isoform distribution in all muscles except the SM. The VL and gracilis presented the greatest fiber type switch with approximately 21% of type I fibers switching to type IIA fibers. However, the fiber type shifts induced by RAC supplementation had little to no effect on subjective and objective color measurements during the 5-d retail display period. Metmyoglobin and oxymyoglobin accumulation, L*, a*, and b*-values were not affected (P > 0.05) by RAC supplementation. Percent nitric oxide metmyoglobin reduction data indicate that reducing ability of RAC-treated steaks from the adductor and longissimus lumborum were significantly affected (P < 0.05). Visual panel data suggest that RAC tended (P < 0.10) to have the most detrimental effect on the lean color and surface discoloration scores of steaks from the VL during the last 3 d of display. Ractopamine significantly (P < 0.05) increased the surface discoloration of the rectus femoris and SM on d 5. Although RAC supplementation had no effect on objective color measurements, subjective measurements indicate that it may have some effect on surface discoloration of some muscles.

Effect of ractopamine-hydrochloride and trenbolone acetate on longissimus muscle fiber area, diameter, and satellite cell numbers in cull beef cows.

The objective of this study was to evaluate the effects of coadministration of ractopamine-HCl (RAC) and trenbolone acetate plus estradiol (TBA) on LM fiber cross-sectional area (CSA), diameter, fiber-associated myonuclei, and satellite cell number. Culled crossbred beef cows (n = 98; 11 +/- 1.8 yr old; BCS 4.3 +/- 0.03) from a single ranch in south Florida were fed a concentrate diet for 92 d in a 2 x 2, randomized block design. Cows were blocked by BW on arrival into light (initial BW = 369.75 +/- 2.68 kg and end BW = 501.96 +/- 6.90 kg) and heavy (initial BW = 418.31 +/- 2.75 kg and end BW = 522.15 +/- 7.09 kg) groups before assignment to treatment. Factors included dietary treatment (0 or 15 ppm) and implant status (0 or 80 mg of trenbolone acetate + 16 mg of estradiol). Ractopamine was provided in the diet to 2 pens or half the treatments during the final 35 d of feeding. Cows were slaughtered on d 92. Forty-eight hours postmortem, the 6th-rib portions of the LM were obtained from 10 randomly selected carcasses from each treatment group (n = 40). Cryosections (12 mum) were immunostained for dystrophin and myosin heavy chain I or II for the measurement of fiber CSA and type, respectively. Fiber-associated nuclei and satellite cell numbers were measured in serial cryosections. There was a RAC x TBA interaction (P < 0.05). Type I fiber CSA and diameter were increased (P < 0.05) by TBA and RAC. Type I CSA and diameter were larger (P < 0.05) in TBA + RAC than RAC only. Type II fiber CSA and diameter were not affected by TBA (P = 0.48), RAC (P = 0.15), or TBA + RAC (P = 0.60). Satellite cell numbers and fiber-associated nuclei were not affected (P > 0.05) by implant status or ractopamine supplementation. These results indicate that TBA and RAC preferentially increase the size of type I fibers in cull cows.

Chlamydia pneumoniae expresses genes required for DNA replication but not cytokinesis during persistent infection of HEp-2 cells.

Chlamydia pneumoniae causes community-acquired pneumonia and is associated with several chronic diseases, including asthma and atherosclerosis. The intracellular growth rate of C. pneumoniae slows dramatically during chronic infection, and such persistence leads to attenuated production of new elementary bodies, appearance of morphologically aberrant reticulate bodies, and altered expression of several chlamydial genes. We used an in vitro system to further characterize persistent C. pneumoniae infection, employing both ultrastructural and transcriptional activity measurements. HEp-2 cells were infected with C. pneumoniae (TW-183) at a multiplicity of infection of 3:1, and at 2 h postinfection gamma interferon (IFN-gamma) was added to the medium at 0.15 or 0.50 ng/ml. Treated and untreated cultures were harvested at several times postinfection. RNA was isolated and reverse transcribed, and reverse transcription (RT)-PCR analyses targeting primary transcripts from chlamydial rRNA operons as well as dnaA, polA, mutS, minD, ftsK, and ftsW mRNA were done. Some cultures were fixed and stained for electron microscopic analysis, and a real-time PCR assay was used to assess relative chlamydial chromosome accumulation under each culture condition. The latter assays showed that bacterial chromosome copies accumulated severalfold during IFN-gamma treatment of infected HEp-2 cells, although less accumulation was observed in cells treated with the higher dose. Electron microscopy demonstrated that high-dose IFN-gamma treatment elicited aberrant forms of the bacterium. RT-PCR showed that chlamydial primary rRNA transcripts were present in all IFN-gamma-treated and untreated cell cultures, indicating bacterial metabolic activity. Transcripts from dnaA, polA, mutS, and minD, all of which encode products for bacterial chromosome replication and partition, were expressed in IFN-gamma-treated and untreated cells. In contrast, ftsK and ftsW, encoding products for bacterial cell division, were expressed in untreated cells, but expression was attenuated in cells treated with low-dose IFN-gamma and absent in cells given the high dose of cytokine. Thus, the development of persistence included production of transcripts for DNA replication-related, but not cell division-related, genes. These results provide new insight regarding molecular activities that accompany persistence of C. pneumoniae, as well as suggesting requirements for reactivation from persistent to productive growth.

Chlamydia trachomatis persistence in the female mouse genital tract: inducible nitric oxide synthase and infection outcome.

It was previously reported that female mice resolve a primary Chlamydia trachomatis urogenital infection independent of inducible nitric oxide synthase (iNOS). We now report that although iNOS-deficient (NOS2(-/-)) mice resolve culture-apparent infection in a fashion similar to that of normal control (NOS2(+/+)) mice, they sustain significantly increased rates of disease, as assessed by hydrosalpinx formation. PCR amplification of ompA followed by Southern blot detection of amplicands revealed the presence of chlamydial DNA in the lower genital tracts of both NOS2(-/-) and NOS2(+/+) mice at > or =120 days postinfection and in upper genital tract tissues at >120 days postinfection. However, only NOS2(-/-) mice shed low numbers of viable chlamydiae from the lower genital tract after immunosuppressive treatment at 120 days postinfection. When cultured primary murine lung fibroblasts were activated in the presence of gamma interferon (IFN-gamma), inhibition of chlamydial growth occurred in both NOS2(+/+) and NOS2(-/-) cells, but the inhibition was reversible after removal of the cytokine in the NOS2(-/-) primary cell culture only. The iNOS-independent inhibition was microbistatic but was independent of 2,3-indoleamine dioxygenase activity. We conclude that chlamydial DNA and antigens persist in mice subsequent to culture-apparent resolution. In addition, IFN-gamma induces in vivo inhibition of chlamydial growth through microbistatic mechanisms in the absence of iNOS activity, but in the presence of iNOS activity, IFN-gamma is microbicidal and effects eradication.

Patients tell of their images, expectations, and experiences with physicians and nurses on an AIDS-designated unit.

Throughout the 1980s and 1990s, there were only a few studies addressing the relationship of health care professionals and patients with AIDS from the patient's viewpoint. This descriptive, qualitative study explored patients' perceptions and experiences with physicians and nurses on an AIDS-designated unit in New York City. The data reveal patients' physical and emotional images and expectations of physicians and nurses. In meeting their needs, patients expect physicians and nurses to attend to their physical needs as the priority but do not expect them to address their emotional and social needs. Although patients appreciate recognition of their spiritual needs, they attempt to avoid discussions about religion. Patients characterized "special" and "difficult" physicians and nurses. Patients emphasized the importance of establishing a caring relationship through the professionals' therapeutic use of self. With knowledge of what is valued by patients in their relationship with physicians and nurses, health professionals have an opportunity to reflect on their own caregiving experiences and learn ways of enriching and supporting those relationships with the intent of improving the quality of care.

TheNational Commission on Nurse Anesthesia Education 10 years later--Part 1: The commission years (1989-1994).

The significant decrease in the number of anesthesia providers during the late 1980s prompted American Association of Nurse Anesthetists (AANA) leaders to establish the National Commission on Nurse Anesthesia Education (NCNAE). The NCNAE was charged with scrutinizing all aspects of nurse anesthesia educational programs and developing strategies to reverse the critical shortage of nurse anesthetists. The tactics outlined by the commissioners were implemented, and they resulted in an increase of annual nurse anesthesia program graduates. Although there has been continued realization of NCNAE strategies, 10 years later the critical shortage of CRNAs has resurfaced. This 2-part article describes the commission years, the years that followed, and the current status of Certified Registered Nurse Anesthetist (CRNA) manpower.

The National Commission on Nurse Anesthesia Education 10 years later--Part 2: Years following the commission (1994 to present).

In 1989, the National Commission on Nurse Anesthesia Education was implemented to reverse a severe shortage of CRNAs. The Commission, charged with scrutinizing all aspects of nurse anesthesia educational programs, developed 8 goals with corresponding strategies that were used by the Commission Implementation Task Force to actualize its charge. These goals and strategies contributed to an increase of annual graduates from nurse anesthesia programs and the development of 10 new programs. These activities were documented in Part 1 of this article, which appeared in the October 2001 AANA Journal. Following completion of the 3-year project, the Council on Accreditation of Nurse Anesthesia Educational Programs (COA) and the AANA Education Committee began carrying out the final recommendations made by the Commission. Part 2 addresses the accomplishments of the Education Committee and COA in implementing the recommendations of the Commission, discusses current status of educational programs and CRNA manpower, and identifies roles for both educators and practitioners in protecting the future of the profession.

The International Federation of Nurse Anesthetists: 10 years later.

In 1978, 2 European nurse anesthetists attended the Annual Meeting of the American Association of Nurse Anesthetists (AANA). Their interest in international cooperation among nurse anesthetists and AANA's agreement planted the seed for what would later become the International Federal of Nurse Anesthetists (IFNA). In this article we describe the history, philosophy, objectives, and functions of the IFNA. We also address the role of a nurse anesthetist worldwide, educational and research activities, and the importance of networking with other organizations. The article concludes with steps toward globalization of the profession and the future of the IFNA.

Physicians reflect on their lived experiences in long-term AIDS care.

Throughout the history of the acquired immunodeficiency syndrome (AIDS) epidemic, the theoretical and empirical literature has emphasized the stressors related to the care of patients with AIDS, and the reluctance of health professionals, including physicians, to provide care to patients with AIDS. However, from the beginning, there have been individuals who have dedicated themselves to the care of patients with AIDS. This descriptive, qualitative study explores the perceptions and experiences of five physicians, specializing in AIDS care, within a large medical center in New York City. Using principles of qualitative data analyses set forth by Carini, the data reveal important themes related to how they became involved in AIDS care; the stresses associated with AIDS caregiving and ways of coping; the rewards of AIDS care; aspects of the physician-AIDS patient relationship and patient characteristics that promote their willingness to care; and recommendations to fellow physicians in caring for patients with AIDS. From what they have said, and not said, palliative care clinicians, educators, and administrators can learn ways of promoting physicians' caregiving potential, and understand the value and intimacy of the physician-patient relationship, particularly within the context of life-threatening illness. This has further implications in promoting the quality of care offered to patients with AIDS and to all patients with an incurable illness, as well as insuring "safe passage" for patients and for the physicians committed to their care.

The International Federation of Nurse Anesthetists: its role in the globalization of nurse anesthesia education and practice.

Since its beginning in 1989, the International Federation of Nurse Anesthetists (IFNA) has had as its major goal in the advancement of educational standards and practices that support and enhance patient care and safety. This article highlights the development of the IFNA, its purpose, and its structure. Educational and practice standards are discussed and quality assurance in international education highlighted.

Newer trends in the prevention or treatment of postoperative nausea and vomiting.

Postoperative nausea and vomiting are common and distressing postsurgical complications. Prevention or early treatment of this complication should be a goal of all anesthesia providers. This article addresses the pathophysiology of nausea and vomiting and identifies patients at risk for this complication. Pharmacological actions and side effects of commonly used antiemetics are addressed. The new serotonin antagonists and combined antiemetic therapy are highlighted.

The application process for nurse anesthesia programs: is there room for improvement?

In summary, we have observed that competition among programs for applicants has been strong in recent years. We believe the answers to preparation of adequate numbers of CRNAs in the future should be based upon cooperation and major recruitment activities within our geographical area. In addition, the results of this study will help us focus on strengths and areas needing improvement in our application process and programs. This is important to attract well-qualified students and maintain our reputation for excellence.

Intracellular tryptophan pool sizes may account for differences in gamma interferon-mediated inhibition and persistence of chlamydial growth in polarized and nonpolarized cells.

Gamma interferon (IFN-gamma) is an important factor in the modulating inhibition of intracellular chlamydial growth and persistence. In human epithelial cells and macrophages, this inhibition is the result of depletion of the essential amino acid tryptophan via the IFN-gamma-induced enzyme indoleamine 2, 3-dioxygenase. Under these conditions, chlamydiae must successfully compete with the host cell for limited resources in order to maintain viability. We provide evidence to support the hypothesis that the host cell polarization state influences the host-pathogen interplay and outcome of IFN-gamma-mediated inhibition. In polarized cells, intracellular soluble tryptophan pools were larger than those in nonpolarized cells despite only small differences in the initial uptake rate of this amino acid compared to that in nonpolarized cells. Furthermore, in Chlamydia trachomatis-infected cells, the amounts of tryptophan consumed by the organisms were similar for cells grown in either state. We propose that intracellular tryptophan pool sizes can account for differences in IFN-gamma-mediated chlamydial persistence and growth inhibition in polarized and nonpolarized cells. Collectively, these results argue that polarized cell models, which more accurately reflect the conditions in vivo, may be more relevant than conventionally cultured cells in the study of intimate intracellular host-parasite interactions.

Moving beyond fear: lessons learned through a longitudinal review of the literature regarding health care providers and the care of people with HIV/AIDS.

This article examines the literature regarding the health care provider/AIDS patient relationship for a 14 year period from 1984 through 1998. For each of the four time periods (1984-1989, 1990-1992, 1992-1995, 1996-1998), we present the general themes and concerns of the literature at that time. We begin the review of each time period with a depiction of what was happening in biomedical circles and in the broader society around HIV/AIDS. To provide a closer look at the setting for the work completed within each time period, we draw on research interviews conducted by the first author with nurses involved in AIDS care since the early days of the epidemic. Nurses'retrospective comments on what it was like to do the work at various times reveal the local reality and provide an important rationale for the work that we review. Each time period closes with a discussion of the lessons learned and suggestions of new possibilities for future efforts to enhance the well-being of both health care providers and patients with HIV/AIDS.

Monitoring for intraoperative awareness.

Despite advances in anesthetic technique and technology, intraoperative awareness continues to occur with alarming regularity. The psychological effects on patients and the medicolegal consequences to providers have created the need for a reliable monitor of the hypnotic component of anesthesia. A new technology known as bispectral analysis (BIS) has the potential to put an end to the devastating occurrence of intraoperative awareness, as well as improve the overall effectiveness of anesthetic delivery and the surgical experience. Applicable to almost any situation requiring sedation or general anesthesia, BIS's reliability is a real-time measure of hypnosis levels.

T-cell receptor Vbeta gene expression in experimental lupus nephritis.

A limited T-cell receptor (TCR) Vbeta repertoire employed by autoreactive T cells may be related to the development and course of autoimmune diseases. Vbeta repertoire skewing has been observed not only in man, but also in animal models of several human autoimmune diseases, such as MRL-lpr mice, which spontaneously develop a systemic lupus erythematosus (SLE)-like disease. Murine chronic graft-versus-host disease (GVHD) is an inducible model for SLE, involving direct interaction between donor T cells and recipient B cells. It is not known whether Vbeta-specific T-cell subsets are pathogenically involved in this model. Retroviral superantigens such as Mls-1 are known to have a profound impact on the TCR Vbeta repertoire in mice. Restriction of the peripheral TCR repertoire may result from intrathymic expression of Mls-1, which causes deletion of T cells expressing Vbeta6, -7, -8.1, or -9. Mls-1 incompatibility between donor and recipient can be used to determine the involvement of these TCR Vbeta families in GVHD. In the present study we induced GVHD in several strain combinations to investigate TCR Vbeta gene expression during GVHD, and the effect of Mls-1 incompatibility on the TCR Vbeta repertoire. TCR Vbeta gene expression was determined using an RNase protection assay. Our results indicate that T cells expressing the Vbeta2 or Vbeta16 chain play an important pathogenetic role, while T cells bearing the Vbeta1 or Vbeta6 chain may be related to self-limitation of the lupus-like disease in this model.

AANA Journal course: update for nurse anesthetists--diabetes mellitus: overview and current concepts in anesthetic management.

Diabetes mellitus is one of the more common endocrine disorders encountered in the anesthetic management of surgical and obstetrical patients. These patients often have complications associated with the disease process which may increase perioperative morbidity and mortality. Optimal management depends upon an understanding of the disease process as well as special considerations unique to the diabetic. This AANA Journal course reviews the pathophysiology of diabetes and common complications associated with the disease. Perioperative considerations include assessment and metabolic control during the time of surgical stress. In concludes with acute complications and their recognition and management.