Aspects of the early moments of interaction between tachyzoites of Toxoplasma gondii with neutrophils.

The interaction of the tachyzoite stage of Toxoplasma gondii with neutrophils was investigated. Morphological aspects of the initial moments of interaction were analyzed by transmission and scanning electron microscopy, revealing at least three types of reaction from the leukocytes to the parasite: the projection of filopodia, formation of a tunnel-like projection involving the parasite, and invagination of the leukocyte surface at the point of entry. The influence on infectivity of tyrosine kinase, phosphokinase C and phosphatidylinositol 3 kinase cell signaling pathways were studied with the aid of drugs affecting these enzymes in these cells.

v-Jun stimulates both cdk2 kinase activity and G1/S progression via transcriptional repression of p21 CIP1.

Previous studies have shown that the viral Jun (v-Jun) oncoprotein induces marked alterations in cell cycle control, which are associated with, and may be caused by, increased cdk2 kinase activity. Since p21 CIP1 is an important regulator of cdk2, we investigated whether aberrant expression of this cyclin-dependent kinase inhibitor might contribute to cell cycle deregulation by v-Jun. We find that the basal levels of p21 CIP1 mRNA and protein expression are greatly reduced in chick embryo fibroblasts (CEF) transformed by v-Jun, and that v-Jun blocks the increases in p21 CIP1 expression that normally accompany growth inhibition induced by serum deprivation or confluency in untransformed CEF. Importantly, ectopic expression of p21 CIP1 in v-Jun-transformed CEF inhibits both cdk2 kinase activity and cell cycle progression, indicating that these alterations in p21 CIP1 expression are likely to be functionally significant for growth deregulation. We also investigated the mechanism through which v-Jun disturbs p21 CIP1 expression and the possible involvement of a known p21 CIP1 regulator, p53, as an intermediate in this process. This analysis revealed that repression is mediated primarily at the level of p21 CIP1 gene transcription, however the mechanism is complex; both p53-dependent and -independent mechanisms contribute as judged by analysis of p21 CIP1 promoter mutants and other assays of p53 transcriptional activity.

Further studies on the interaction of Toxoplasma gondii with neutrophils and eosinophils.

Tachyzoites of Toxoplasma gondii are ingested by neutrophils and eosinophils through a process which can be significantly inhibited by previous incubation of the host cells with cytochalasin D. Although dividing zoites within the leukocytes could be observed, after 3 h of infection, killing of parasites within the parasitophorous vacuole was detected. Cytochemical studies showed that both in neutrophils and eosinophils there is a process of NADP(H) oxidase activation, which was higher in the latter.

Midlife women making hormone therapy decisions.

This study focuses on midlife women aged 40-65 years who were in transition to menopause, were menopausal or had a hysterectomy, to examine and better understand hormone therapy (HT) choices women make. Among the nationally representative sample of women in the Commonwealth Fund 1998 Survey of Women's Health (n = 884), 39% of the menopausal women reported current HT use. The two primary reasons for initiating HT are following a doctor's recommendation and seeking relief of menopausal symptoms. Age, education, race, hysterectomy status, having health insurance, use of calcium supplements and comfort in communicating with a doctor are important factors associated with HT use. This study underscores the importance of physicians and other health professionals providing accurate HT information to assist women in making HT decisions.

p53-dependent apoptosis induced by proteasome inhibition in mammary epithelial cells.

We have examined the effects of inhibition of the 26S proteasome in a murine mammary cell line, KIM-2 cells using the peptide aldehyde inhibitor MG132. These studies have demonstrated a clear requirement for proteasome function in cell viability. Induction of apoptosis was observed following MG132 treatment in KIM-2 cells and this death was shown to be dependent on the cell actively traversing the cell cycle. KIM-2 cells were generated using a temperature sensitive T-antigen (Tag) and studies at the permissive temperature (33 degrees C) have shown that a Tag binding protein was essential for this apoptotic response. Studies in two additional cell lines, HC11, which is a mammary epithelial cell line carrying mutant p53 alleles and p53 null ES cells suggest that p53 is actively required for the apoptosis induced as a consequence of proteasome inhibition. These results suggest a pivotal role for the 26S proteasome degradation pathway in progression through the cell cycle in proliferating cells.

v-Jun sensitizes cells to apoptosis by a mechanism involving mitochondrial cytochrome C release.

v-Jun shares the ability of the Myc, E1A, and E2F oncogenes to both sustain cell cycle progression and promote apoptosis in the absence of mitogenic stimulation. To gain an insight into the mechanism of apoptosis sensitization, we examined the possible involvement of key regulatory proteins previously implicated in oncogene-induced cell death during v-Jun-induced apoptosis triggered by serum withdrawal. We observed that ectopic expression of the anti-apoptotic Bcl-2 protein, or of two downstream effectors of growth factor signalling, v-PI 3-Kinase and v-Src, partially or completely suppressed apoptosis. Apoptosis was also observed in the presence of serum growth factors when endogenous PI3K activity was blocked using the synthetic inhibitor LY294002, further suggesting an important role for PI3-K in cell survival. Cytochrome C was released into the cytosol of apoptotic v-Jun expressing cells, and this release was inhibited by Bcl-2, suggesting an important role for mitochondrial dysfunction in v-Jun induced apoptosis. In contrast, inhibition of Fas signalling using dominant negative FADD did not inhibit apoptosis, nor was there any evidence for accumulation or activation of p53 in v-Jun transformed cells. Consistent with this latter observation, inhibition of p53 function by HPV16 E6 protein had no effect on v-Jun induced cell death. Taken together, these results suggest that mitochondrial dysfunction is an important component of the mechanism through which v-Jun sensitizes cells to apoptosis, but that the apoptotic signals elicited by v-Jun upstream of the mitochondria do not depend on increased levels of p53 activity or Fas signalling.

v-Jun overrides the mitogen dependence of S-phase entry by deregulating retinoblastoma protein phosphorylation and E2F-pocket protein interactions as a consequence of enhanced cyclin E-cdk2 catalytic activity.

v-Jun accelerates G(1) progression and shares the capacity of the Myc, E2F, and E1A oncoproteins to sustain S-phase entry in the absence of mitogens; however, how it does so is unknown. To gain insight into the mechanism, we investigated how v-Jun affects mitogen-dependent processes which control the G(1)/S transition. We show that v-Jun enables cells to express cyclin A and cyclin A-cdk2 kinase activity in the absence of growth factors and that deregulation of cdk2 is required for S-phase entry. Cyclin A expression is repressed in quiescent cells by E2F acting in conjunction with its pocket protein partners Rb, p107, and p130; however, v-Jun overrides this control, causing phosphorylated Rb and proliferation-specific E2F-p107 complexes to persist after mitogen withdrawal. Dephosphorylation of Rb and destruction of cyclin A nevertheless occur normally at mitosis, indicating that v-Jun enables cells to rephosphorylate Rb and reaccumulate cyclin A without exogenous mitogenic stimulation each time the mitotic "clock" is reset. D-cyclin-cdk activity is required for Rb phosphorylation in v-Jun-transformed cells, since ectopic expression of the cdk4- and cdk6-specific inhibitor p16(INK4A) inhibits both DNA synthesis and cell proliferation. Despite this, v-Jun does not stimulate D-cyclin-cdk activity but does induce a marked deregulation of cyclin E-cdk2. In particular, hormonal activation of a conditional v-Jun-estrogen receptor fusion protein in quiescent, growth factor-deprived cells stimulates cyclin E-cdk2 activity and triggers Rb phosphorylation and DNA synthesis. Thus, v-Jun overrides the mitogen dependence of S-phase entry by deregulating Rb phosphorylation, E2F-pocket protein interactions, and ultimately cyclin A-cdk2 activity. This is the first report, however, that cyclin E-cdk2, rather than D-cyclin-cdk, is likely to be the critical Rb kinase target of v-Jun.

Deciding about hormone therapy: validation of a model.

OBJECTIVE: The purposes of this study were to (1) validate components of a decision process regarding adoption of hormone therapy and (2) compare the decision processes women used with respect to their evaluation of decision quality. DESIGN: A sample of women participating in a population-based study of midlife women's health participated in individual in-depth interviews. RESULTS: Content analysis of 30 recorded interviews provided evidence that each component of the decision process (precontemplation, contemplation, commitment, critical evaluation, and continuance) was replicated. Few additional codes were identified, and these could be subsumed under the phases of the original decision model. CONCLUSIONS: Women's self-reported statuses on a screening questionnaire corresponded to the stages of the decision model coded from their interviews. What women actually decided to do (use hormone therapy or something else) was not associated with their decision process. Satisfaction with the decision, uncertainty about the decision, and other factors related to the decision were independent of the decision phases.

Current issues in the midwifery management of women living with HIV/AIDS.

Changes in the clinical management of women living with human immunodeficiency virus (HIV) have occurred as a result of significant gains in the scientific knowledge of this retrovirus. As the incidence of HIV/AIDS continues to escalate among female adults and adolescents in the United States, all primary health care providers must anticipate the likelihood of encountering clients with HIV infection. Midwives must be adequately prepared to meet the challenges of managing women with HIV in the early stages of the disease. This article presents a comprehensive review of current demographic trends related to the HIV/AIDS epidemic among U.S. women and a brief overview of the essential immunopathogenesis of HIV. Contemporary issues related to universal counseling, updated testing procedures, and reproductive decision-making are covered. Initial primary care concerns and the management of newly infected seropositive women are included, with a focus on gynecologic issues. Guidance in the current management of HIV-positive pregnant women is offered. Updated antiretroviral prophylaxis recommendations are presented, to prevent perinatal transmission and to delay maternal immunosuppression with subsequent opportunistic infections. The article concludes with implications for health care professionals who provide care for this unique cohort of women.

Primary care for women. Comprehensive sexual health assessment.

This article discusses the fundamentals of sexual functioning and describes the elements of a comprehensive, developmentally relevant sexual health assessment. Personal barriers that may prevent clinicians from comfortably addressing sexual issues are discussed, and useful strategies for facilitating effective, reciprocal communication during a sexual health history are presented. A therapeutic intervention model for counseling, referral, and sexual health assessment of women in the primary care setting is also included.

Ernestine Wiedenbach. Her professional legacy.

A descriptive, historical research study of the life and career path of Ernestine Wiedenbach was conducted. A productive career spanning five decades included accomplishments in prepared childbirth education, family-centered maternity care, nurse-midwifery education, and nursing theory. Wiedenbach's prescriptive theory of nursing with its focus on "clarity of central purpose" stands out as an important early professional achievement of this practitioner, educator, author, and theorist. It represents one of Wiedenbach's many pioneer contributions to nursing as well as to the foundation of the philosophy and goals of nurse-midwifery practice and education.

The value of remanipulating Colles' fractures.

The value of remanipulating a Colles' fracture which has redisplaced after primary reduction was assessed in 50 patients. In those over 60 years old, remanipulation failed to achieve a lasting improvement in position, while the majority of those under 60 years maintained a significant improvement in dorsal angulation. It is concluded that the elderly patient does not benefit from this procedure.