Randomized Controlled Trial of Rise, A Community-Based Culturally Congruent Counseling Intervention to Support Antiretroviral Therapy Adherence Among Black/African American Adults Living with HIV.

Structural inequities have led to HIV disparities, including relatively low antiretroviral therapy adherence and viral suppression rates among Black Americans living with HIV. We conducted a randomized controlled trial of Rise, a community-based culturally congruent adherence intervention, from January 2018 to December 2021 with 166 (85 intervention, 81 control) Black adults living with HIV in Los Angeles County, California [M (SD) = 49.0 (12.2) years-old; 76% male]. The intervention included one-on-one counseling sessions using basic Motivational Interviewing style to problem solve about adherence, as well as referrals to address unmet needs for social determinants of health (e.g., housing services, food assistance). Assessments included electronically monitored adherence; HIV viral load; and baseline, 7-month follow-up, and 13-month follow-up surveys of sociodemographic characteristics, HIV stigma, medical mistrust, and HIV-serostatus disclosure. Repeated-measures intention-to-treat regressions indicated that Rise led to significantly (two-fold) higher adherence likelihood, lower HIV stigmatizing beliefs, and reduced HIV-related medical mistrust. Effects on HIV viral suppression, internalized stigma, and disclosure were non-significant. Moreover, Rise was cost-effective based on established standards: The estimated cost per person to reach optimal adherence was $335 per 10% increase in adherence. Interventions like Rise, that are culturally tailored to the needs of Black populations, may be optimal for Black Americans living with HIV (ClinicalTrials.gov #NCT03331978).

RESUMEN: Las desigualdades estructurales han dado lugar a disparidades relacionadas con el VIH, incluyendo la relativamente baja adherencia a la terapia antirretroviral (TAR) y las tasas de supresión viral entre los afroamericanos que viven con el VIH. Conducimos una prueba controlada aleatoria de Rise, una intervención de adherencia culturalmente congruente basada en la comunidad, desde Enero de 2018 hasta Diciembre de 2021 con 166 (85 intervención, 81 controlada) adultos afroamericanos que viven con el VIH en el condado de Los Ángeles, California [M (SD) = 49.0 (12,2) años; 76% de hombres]. La intervención incluyó sesiones de asesoramiento individualizadas, usando el estilo básico Motivacional para las entrevistas, para resolver los problemas de adherencia como también referencias para confrontar sus necesidades insatisfechas de los determinantes sociales de la salud (por ejemplo, servicios de vivienda y asistencia de alimentos). Las evaluaciones incluyeron la adherencia monitoreada electrónicamente; la carga viral del VIH; y encuestas de referencia, seguimiento a los 7 meses y seguimiento a los 13 meses sobre características sociodemográficas, el estigma del VIH, la desconfianza médica y divulgación del estado serológico respecto al VIH. Los efectos sobre la supresión viral del VIH, el estigma interiorizado y la revelación de información no fueron significativos. Además, Rise fue rentable según los estándares establecidos: El costo estimado por persona para alcanzar la adherencia óptima fue de 335 dólares por cada 10% de aumento en la adherencia. Las intervenciones como Rise, que se adaptan culturalmente a las necesidades de las poblaciones afroamericana, podrían ser óptimas para los estadounidenses afroamericanos que viven con el VIH.

Comparing advance care planning between older adults with and without HIV.

We compared completion of advance directives (AD), designation of a healthcare proxy, and stage in the advance care planning process (pre-contemplation/contemplation, preparation/action) between older adults with (N = 110) and without (N = 50) HIV. Participants' mean age was 61.3, most identified as male (82%) and sexual minorities (74%), were racially/ethnically diverse (44% white, 28% Latinx, 16% Black); 37% had an AD and 44% had a healthcare proxy. In adjusted logistic regressions, HIV- individuals had higher odds of being in preparation/action for having an AD (aOR: 2.6) and healthcare proxy (aOR: 3.6) compared to people living with HIV. Older age (aOR: 1.1) and having a sense of greater purpose in life (aOR: 2.1) were also positively associated with being in the preparation/action stage for having a healthcare proxy.

Ebola Virus RNA in Semen from an HIV-Positive Survivor of Ebola.

Ebola virus is known to persist in semen of male survivors of Ebola virus disease (EVD). However, maximum duration of, or risk factors for, virus persistence are unknown. We report an EVD survivor with preexisting HIV infection, whose semen was positive for Ebola virus RNA 565 days after recovery from EVD.

Implementation of a National Semen Testing and Counseling Program for Male Ebola Survivors - Liberia, 2015-2016.

According to World Health Organization (WHO) data, the Ebola virus disease (Ebola) outbreak that began in West Africa in 2014 has resulted in 28,603 cases and 11,301 deaths (1). In March 2015, epidemiologic investigation and genetic sequencing in Liberia implicated sexual transmission from a male Ebola survivor, with Ebola virus detected by reverse transcription-polymerase chain reaction (RT-PCR) 199 days after symptom onset (2,3), far exceeding the 101 days reported from an earlier Ebola outbreak (4). In response, WHO released interim guidelines recommending that all male survivors, in addition to receiving condoms and sexual risk reduction counseling at discharge from an Ebola treatment unit (ETU), be offered semen testing for Ebola virus RNA by RT-PCR 3 months after disease onset, and every month thereafter until two consecutive semen specimens collected at least 1 week apart test negative for Ebola virus RNA (5). Male Ebola survivors should also receive counseling to promote safe sexual practices until their semen twice tests negative. When these recommendations were released, testing of semen was not widely available in Liberia. Challenges in establishing and operating the first nationwide semen testing and counseling program for male Ebola survivors included securing sufficient resources for the program, managing a public health semen testing program in the context of ongoing research studies that were also collecting and screening semen, identification of adequate numbers of trained counselors and appropriate health communication messages for the program, overcoming Ebola survivor-associated stigma, identification and recruitment of male Ebola survivors, and operation of mobile teams.

Roles of hepatocyte and myeloid CXC chemokine receptor-2 in liver recovery and regeneration after ischemia/reperfusion in mice.

UNLABELLED: Previous studies have demonstrated the significance of signaling through the CXC chemokine receptor-2 (CXCR2) receptor in the process of recovery and regeneration of functional liver mass after hepatic ischemia/reperfusion (I/R). CXCR2 is constitutively expressed on both neutrophils and hepatocytes; however, the cell-specific roles of this receptor are unknown. In the present study, chimeric mice were created through bone marrow transplantation (BMT) using wild-type and CXCR2-knockout mice, yielding selective expression of CXCR2 on hepatocytes (Hep) and/or myeloid cells (My) in the following combinations: Hep+/My+; Hep-/My+; Hep+/My-; and Hep-/My-. These tools allowed us to assess the contributions of myeloid and hepatocyte CXCR2 in the recovery of the liver after I/R injury. Flow cytometry confirmed the adoption of the donor phenotype in neutrophils. Interestingly, Kupffer cells from all chimeras lacked CXCR2 expression. Recovery/regeneration of hepatic parenchyma was assessed by histologic assessment and measurement of hepatocyte proliferation. CXCR2(Hep+/My+) mice showed the least amount of liver recovery and hepatocyte proliferation, whereas CXCR2(Hep-/My-) mice had the greatest liver recovery and hepatocyte proliferation. CXCR2(Hep+/My-) mice had enhanced liver recovery, with hepatocyte proliferation similar to CXCR2(Hep-/My-) mice. Myeloid expression of CXCR2 directly regulated CXC chemokine expression levels after hepatic I/R, such that mice lacking myeloid CXCR2 had markedly increased chemokine expression, compared with mice expressing CXCR2 on myeloid cells. CONCLUSION: The data suggest that CXCR2 on myeloid cells is the predominant regulator of liver recovery and regeneration after I/R injury, whereas hepatocyte CXCR2 plays a minor, secondary role. These findings suggest that myeloid cell-directed therapy may significantly affect liver regeneration after liver resection or transplantation.

Is group A thawed plasma suitable as the first option for emergency release transfusion? (CME).

BACKGROUND: Group AB plasma, which lacks anti-A and anti-B isohemagglutinins, is issued for emergency transfusion when a patient's ABO group is unknown, but the relative scarcity of group AB blood donors limits its availability. We sought to establish a thawed plasma inventory to improve the rapid availability of plasma in the emergency release setting but were concerned about potential wastage of group AB plasma. STUDY DESIGN AND METHODS: Recognizing that plasma-incompatible apheresis platelets are routinely transfused and only rarely result in hemolytic reactions if the donor is blood group O, and considering that group A plasma would be compatible with approximately 85% of our patient population, we instituted an emergency release policy whereby thawed group A plasma is issued to all patients of unknown blood group or if compatible plasma is not available. ABO-compatible plasma is then issued, if needed, once the patient's blood group is determined. We prospectively assessed the outcomes of all patients who received incompatible plasma under our policy. RESULTS: During the first 5 years under this policy, 385 emergency release requests for plasma were received by our blood bank. Among them, 23 group B or AB patients met criteria for receiving a median of 2 units of incompatible group A plasma. No hemolytic transfusion reactions or other adverse events related to transfusion were seen in any of these 23 patients. CONCLUSION: We propose that group A plasma may be an acceptable alternative to AB plasma as the first option in the emergency release setting.

Safety and efficacy of autologous hemopoietic progenitor cell collection in tandem with hemodialysis in multiple myeloma with myeloma cast nephropathy.

Autologous hemopoietic progenitor cell (HPC) collection is the most frequent indication for an apheresis procedure in patients with multiple myeloma, up to 10% of whom may also require hemodialysis because of myeloma kidney. We investigated whether HPC collection could be performed in tandem with hemodialysis, to avoid extra outpatient visits for extracorporeal procedures, without compromising the efficacy of the hemodialysis, the HPC collection efficiency (CE) or patient safety. Four dialysis-dependent patients with multiple myeloma underwent 5 large volume leukapheresis HPC collections in tandem with hemodialysis. Under our protocol, all of the blood processed through the apheresis instrument was dialyzed against a standard calcium-rich bath prior to being returned to the patient, therefore no supplemental calcium was needed. No significant changes in pulse rate (P = 0.625) or mean arterial pressure (P = 0.188) were noted between the start and end of the procedures. The patients exhibited no signs or symptoms of hypocalcemia or other adverse effects. Calculated urea reduction ratios ranged between 62.5 and 73.9%, and HPC CE was between 53 and 84% for 4 of the 5 procedures, indicating that there was no compromise of either procedure when performed in tandem. Ionized calcium measured at the beginning, midpoint and end of every procedure did not change (P = 0.954). The two patients who proceeded to autologous HPC transplant engrafted on Days 11 and 10, respectively. We conclude that autologous HPC collection can safely be performed in tandem with hemodialysis without compromising the efficacy of dialysis, HPC CE, or patient safety.

Differential CXCR4 expression on hematopoietic progenitor cells versus stem cells directs homing and engraftment.

Gene therapy involves a substantial loss of hematopoietic stem and progenitor cells (HSPC) during processing and homing. Intra-BM (i.b.m.) transplantation can reduce homing losses, but prior studies have not yielded promising results. We studied the mechanisms involved in homing and engraftment of i.b.m. transplanted and i.v. transplanted genetically modified (GM) human HSPC. We found that i.b.m. HSPC transplantation improved engraftment of hematopoietic progenitor cells (HPC) but not of long-term repopulating hematopoietic stem cells (HSC). Mechanistically, HPC expressed higher functional levels of CXCR4 than HSC, conferring them a retention and homing advantage when transplanted i.b.m. Removing HPC and transplanting an HSC-enriched population i.b.m. significantly increased long-term engraftment over i.v. transplantation. Transient upregulation of CXCR4 on GM HSC-enriched cells, using a noncytotoxic portion of viral protein R (VPR) fused to CXCR4 delivered as a protein in lentiviral particles, resulted in higher homing and long-term engraftment of GM HSC transplanted either i.v. or i.b.m. compared with standard i.v. transplants. Overall, we show a mechanism for why i.b.m. transplants do not significantly improve long-term engraftment over i.v. transplants. I.b.m. transplantation becomes relevant when an HSC-enriched population is delivered. Alternatively, CXCR4 expression on HSC, when transiently increased using a protein delivery method, improves homing and engraftment specifically of GM HSC.

Survival of an HLA-mismatched, bioengineered RPE implant in dry age-related macular degeneration.

Cell-based therapies face challenges, including poor cell survival, immune rejection, and integration into pathologic tissue. We conducted an open-label phase 1/2a clinical trial to assess the safety and preliminary efficacy of a subretinal implant consisting of a polarized monolayer of allogeneic human embryonic stem cell-derived retinal pigmented epithelium (RPE) cells in subjects with geographic atrophy (GA) secondary to dry age-related macular degeneration. Postmortem histology from one subject with very advanced disease shows the presence of donor RPE cells 2 years after implantation by immunoreactivity for RPE65 and donor-specific human leukocyte antigen (HLA) class I molecules. Markers of RPE cell polarity and phagocytosis suggest donor RPE function. Further histologic examination demonstrated CD34+ structures beneath the implant and CD4+, CD68+, and FoxP3+ cells in the tissue. Despite significant donor-host HLA mismatch, no clinical signs of retinitis, vitreitis, vasculitis, choroiditis, or serologic immune response were detected in the deceased subject or any other subject in the study. Subretinally implanted, HLA-mismatched donor RPE cells survive, express functional markers, and do not elicit clinically detectable intraocular inflammation or serologic immune responses even without long-term immunosuppression.

Ectopic HOXB4 overcomes the inhibitory effect of tumor necrosis factor-{alpha} on Fanconi anemia hematopoietic stem and progenitor cells.

Ectopic delivery of HOXB4 elicits the expansion of engrafting hematopoietic stem cells (HSCs). We hypothesized that inhibition of tumor necrosis factor-alpha (TNF-alpha) signaling may be central to the self-renewal signature of HOXB4. Because HSCs derived from Fanconi anemia (FA) knockout mice are hypersensitive to TNF-alpha, we studied Fancc(-/-) HSCs to determine the physiologic effects of HOXB4 on TNF-alpha sensitivity and the relationship of these effects to the engraftment defect of FA HSCs. Overexpression of HOXB4 reversed the in vitro hypersensitivity to TNF-alpha of Fancc(-/-) HSCs and progenitors (P) and partially rescued the engraftment defect of these cells. Coexpression of HOXB4 and the correcting FA-C protein resulted in full correction compared with wild-type (WT) HSCs. Ectopic expression of HOXB4 resulted in a reduction in both apoptosis and reactive oxygen species in Fancc(-/-) but not WT HSC/P. HOXB4 overexpression was also associated with a significant reduction in surface expression of TNF-alpha receptors on Fancc(-/-) HSC/P. Finally, enhanced engraftment was seen even when HOXB4 was expressed in a time-limited fashion during in vivo reconstitution. Thus, the HOXB4 engraftment signature may be related to its effects on TNF-alpha signaling, and this pathway may be a molecular target for timed pharmacologic manipulation of HSC during reconstitution.

Toward extended phenotype matching: a new operational paradigm for the transfusion service.

BACKGROUND: Conventional pretransfusion testing uses hemagglutination to ensure donor-recipient compatibility for ABO/D status and recipient alloantibodies. While screening large numbers of donor units for multiple antigens by hemagglutination is impractical, novel methods of DNA analysis permit the rapid determination of an extended human erythrocyte antigen (xHEA) phenotype. A prospective observational study was conducted at four hospital transfusion services to test an alternative paradigm of identifying xHEA-typed units for patients in three cohorts by utilizing DNA analysis and a novel inventory management model. STUDY DESIGN AND METHODS: xHEA typing of recipient samples and donor units of known ABO/D status was performed by HEA analysis (BeadChip, BioArray Solutions). xHEA-typed units were assigned to pending transfusion requests using an inventory management system designed to simulate blood order processing. The fraction of requests fulfilled, or "fill fraction" (FF) was determined at four levels of matching stringency. RESULTS: For alloimmunized patients, all but one participating site observed an FF of more than 95% when matching for ABO, D, and known alloantibodies and an FF of more than 90% when additionally matching for C, c, E, e, and K; the site handling the most challenging requests still observed FFs of 62 and 51%, respectively. FF was found to correlate positively with the ratio of available donor units to units requested and negatively with the degree of recipient alloimmunization. CONCLUSION: This study demonstrates that substantial fill fractions can be achieved by selecting existing donor units for xHEA analysis and operating an inventory management system for efficient allocation of units to recipients.

The structure and evolution of centromeric transition regions within the human genome.

An understanding of how centromeric transition regions are organized is a critical aspect of chromosome structure and function; however, the sequence context of these regions has been difficult to resolve on the basis of the draft genome sequence. We present a detailed analysis of the structure and assembly of all human pericentromeric regions (5 megabases). Most chromosome arms (35 out of 43) show a gradient of dwindling transcriptional diversity accompanied by an increasing number of interchromosomal duplications in proximity to the centromere. At least 30% of the centromeric transition region structure originates from euchromatic gene-containing segments of DNA that were duplicatively transposed towards pericentromeric regions at a rate of six-seven events per million years during primate evolution. This process has led to the formation of a minimum of 28 new transcripts by exon exaptation and exon shuffling, many of which are primarily expressed in the testis. The distribution of these duplicated segments is nonrandom among pericentromeric regions, suggesting that some regions have served as preferential acceptors of euchromatic DNA.

Developing evidence-based practice: experiences of senior and junior clinical nurses.

AIM: This paper is a report of a study to compare factors influencing the development of evidence-based practice identified by junior and senior nurses. BACKGROUND: Assessing factors influencing the achievement of evidence-based practice is complex. Consideration needs to be given to a range of factors including different types of evidence, the skills nurses require to achieve evidence-based practice together with barriers and facilitators. To date, little is known about the relative skills of junior and senior clinical nurses in relation to evidence-based practice. METHOD: A cross-sectional survey was undertaken at two hospitals in England, using the Developing Evidence-Based Practice Questionnaire administered to Registered Nurses (n = 1411). A useable sample of 598 (response rate 42%) was achieved. Data were collected in 2003, with comparisons undertaken between junior and senior nurses. FINDINGS: Nurses relied heavily on personal experience and communication with colleagues rather than formal sources of knowledge. All respondents demonstrated confidence in accessing and using evidence for practice. Senior nurses were more confident in accessing all sources of evidence including published sources and the Internet, and felt able to initiate change. Junior nurses perceived more barriers in implementing change, and were less confident in accessing organizational evidence. Junior nurses perceived lack of time and resources as major barriers, whereas senior nurses felt empowered to overcome these constraints. CONCLUSION: Senior nurses are developing skills in evidence-based practice. However, the nursing culture seems to disempower junior nurses so that they are unable to develop autonomy in implementing evidence-based practice.

Implementation and Operational Research: The Navigation Program: An Intervention to Reengage Lost Patients at 7 HIV Clinics in Los Angeles County, 2012-2014.

The Navigation Program is a health department-community agency collaboration to reengage lost HIV clinic patients in Los Angeles County using best practices from disease investigator services locator activities and the Antiretroviral Treatment Access Study (ARTAS), a CDC-recommended intervention. Clinic databases were reviewed to identify HIV patients who: (1) had no HIV care visits in 6-12 months and last viral load was greater than 200 copies per milliliter; (2) had no HIV care visits in >12 months; (3) were newly diagnosed and never in care; or (4) were recently released from jail/prison/other institution with no regular HIV medical provider. Patients were contacted by trained Navigators using locator information from clinic medical records, HIV/sexually transmitted disease surveillance, and people-finder databases and offered enrollment in a modified ARTAS intervention. Among the 1139 lost clinic patients identified, 36% were in care elsewhere, 29% could not be located, 8% returned to the clinic independently, 4% declined enrollment, and 7% (n = 78) were located and enrolled in the intervention. Participants received an average of 4.5 Navigator sessions over 11.6 hours. Among reengaged patients, 68% linked within 3 months, 85% linked within 6 months, and 94% linked within 12 months, and 82% of linked patients were retained in care 12 months after study enrollment. The percentage of linked patients virally suppressed was compared at time of linkage by the Navigators (52%) with a second viral load measure after linkage to care (63%) (χ(2) = 11.8; P = 0.01). The combined disease investigator services/ARTAS model of reengagement was effective for locating and reengaging lost HIV clinic patients. Access to HIV surveillance data is critical for the efficient identification of persons truly in need of reengagement.

Group-level interventions for persons living with HIV: a catalyst for individual change.

This study describes the perceived influence of group-level HIV interventions on persons living with HIV in Los Angeles, California. Funded by the Centers for Disease Control and Prevention and developed by a broad range of community organizations, group-level interventions ranged from small skills-building workshops to large educational forums and to intensive weekend gatherings. Recognizing the relationship between psychosocial factors and HIV-related risk taking, these interventions were designed not only to provide HIV prevention education and develop risk reduction skills but also to bring people together to facilitate the formation of supportive relationships. The formative data presented here are based on 35 qualitative interviews conducted with a sample of intervention participants. Interviews highlight the experiential opportunities that group interventions offer with respect to HIV knowledge, social support, HIV disclosure skills, and HIV risk reductions. Participants talked highly of their experiences in group-level interventions, suggesting that they should be considered an important prevention strategy for people living with HIV.

Efficacy of intranasal naloxone as a needleless alternative for treatment of opioid overdose in the prehospital setting.

Prehospital providers are at increased risk for blood-borne exposure and disease due to the nature of their environment. The use if intranasal (i.n.) medications in high-risk populations may limit this risk of exposure. To determine the efficacy of i.n. naloxone in the treatment of suspected opiate overdose patients in the prehospital setting, a prospective, nonrandomized trial of administering i.n. naloxone by paramedics to patients with suspected opiate overdoses over a 6-month period was performed. All adult patients encountered in the prehospital setting as suspected opiate overdose (OD), found down (FD), or with altered mental status (AMS) who met the criteria for naloxone administration were included in the study. i.n. naloxone (2 mg) was administered immediately upon patient contact and before i.v. insertion and administration of i.v. naloxone (2 mg). Patients were then treated by EMS protocol. The main outcome measures were: time of i.n. naloxone administration, time of i.v. naloxone administration, time of appropriate patient response as reported by paramedics. Ninety-five patients received i.n. naloxone and were included in the study. A total of 52 patients responded to naloxone by either i.n. or i.v., with 43 (83%) responding to i.n. naloxone alone. Seven patients (16%) in this group required further doses of i.v. naloxone. In conclusion, i.n. naloxone is a novel alternative method for drug administration in high-risk patients in the prehospital setting with good overall effectiveness. The use of this route is further discussed in relation to efficacy of treatment and minimizing the risk of blood-borne exposures to EMS personnel.

Rac1 is essential for intraembryonic hematopoiesis and for the initial seeding of fetal liver with definitive hematopoietic progenitor cells.

Definitive hematopoietic stem and progenitor cells (HSCs/Ps) originating from the yolk sac and/or para-aorta-splanchno-pleura/aorta-gonad-mesonephros are hypothesized to colonize the fetal liver, but mechanisms involved are poorly defined. The Rac subfamily of Rho GTPases has been shown to play essential roles in HSC/P localization to the bone marrow following transplantation. Here, we study the role of Rac1 in HSC/P migration during ontogeny and seeding of fetal liver. Using a triple-transgenic approach, we have deleted Rac1 in HSCs/Ps during very early embryonic development. Without Rac1, there was a decrease in circulating HSCs/Ps in the blood of embryonic day (E) 10.5 embryos, while yolk sac definitive hematopoiesis was quantitatively normal. Intraembryonic hematopoiesis was significantly impaired in Rac1-deficient embryos, culminating with absence of intra-aortic clusters and fetal liver hematopoiesis. At E10.5, Rac1-deficient HSCs/Ps displayed decreased transwell migration and impaired inter-action with the microenvironment in migration-dependent assays. These data suggest that Rac1 plays an important role in HSC/P migration during embryonic development and is essential for the emergence of intraembryonic hematopoiesis.

Reciprocal relationship between O6-methylguanine-DNA methyltransferase P140K expression level and chemoprotection of hematopoietic stem cells.

Retroviral-mediated delivery of the P140K mutant O(6)-methylguanine-DNA methyltransferase (MGMT(P140K)) into hematopoietic stem cells (HSC) has been proposed as a means to protect against dose-limiting myelosuppressive toxicity ensuing from chemotherapy combining O(6)-alkylating agents (e.g., temozolomide) with pseudosubstrate inhibitors (such as O(6)-benzylguanine) of endogenous MGMT. Because detoxification of O(6)-alkylguanine adducts by MGMT is stoichiometric, it has been suggested that higher levels of MGMT will afford better protection to gene-modified HSC. However, accomplishing this goal would potentially be in conflict with current efforts in the gene therapy field, which aim to incorporate weaker enhancer elements to avoid insertional mutagenesis. Using a panel of self-inactivating gamma-retroviral vectors that express a range of MGMT(P140K) activity, we show that MGMT(P140K) expression by weaker cellular promoter/enhancers is sufficient for in vivo protection/selection following treatment with O(6)-benzylguanine/temozolomide. Conversely, the highest level of MGMT(P140K) activity did not promote efficient in vivo protection despite mediating detoxification of O(6)-alkylguanine adducts. Moreover, very high expression of MGMT(P140K) was associated with a competitive repopulation defect in HSC. Mechanistically, we show a defect in cellular proliferation associated with elevated expression of MGMT(P140K), but not wild-type MGMT. This proliferation defect correlated with increased localization of MGMT(P140K) to the nucleus/chromatin. These data show that very high expression of MGMT(P140K) has a deleterious effect on cellular proliferation, engraftment, and chemoprotection. These studies have direct translational relevance to ongoing clinical gene therapy studies using MGMT(P140K), whereas the novel mechanistic findings are relevant to the basic understanding of DNA repair by MGMT.

Factors influencing the development of evidence-based practice: a research tool.

AIM: The paper reports a study to develop and test a tool for assessing a range of factors influencing the development of evidence-based practice among clinical nurses. BACKGROUND: Achieving evidence-based practice is a goal in nursing frequently cited by the profession and in government health policy directives. Assessing factors influencing the achievement of this goal, however, is complex. Consideration needs to be given to a range of factors, including different types of evidence used to inform practice, barriers to achieving evidence-based practice, and the skills required by nurses to implement evidence-based care. METHODS: Measurement scales currently available to investigate the use of evidence in nursing practice focus on nurses' sources of knowledge and on barriers to the use of research evidence. A new, wider ranging Developing Evidence-Based Practice questionnaire was developed and tested for its measurement properties in two studies. In study 1, a sample of 598 nurses working at two hospitals in one strategic health authority in northern England was surveyed. In study 2, a slightly expanded version of the questionnaire was employed in a survey of 689 community nurses in 12 primary care organizations in two strategic health authorities, one in northern England and the other in southern England. FINDINGS: The measurement characteristics of the new questionnaire were shown to be acceptable. Ten significant, and readily interpretable, factors were seen to underlie nurses' relation to evidence-based practice. CONCLUSION: Strategies to promote evidence-based practice need to take account of the differing needs of nurses and focus on a range of sources of evidence. The Developing Evidence-Based Practice questionnaire can assist in assessing the specific 'evidencing' tendencies of any given group of nurses.