Safety and efficacy of tenecteplase in patients with wake-up stroke assessed by non-contrast CT (TWIST): a multicentre, open-label, randomised controlled trial

BACKGROUND

Current evidence supports the use of intravenous thrombolysis with alteplase in patients with wake-up stroke selected with MRI or perfusion imaging and is recommended in clinical guidelines. However, access to advanced imaging techniques is often scarce. We aimed to determine whether thrombolytic treatment with intravenous tenecteplase given within 4·5 h of awakening improves functional outcome in patients with ischaemic wake-up stroke selected using non-contrast CT.

METHODS

TWIST was an investigator-initiated, multicentre, open-label, randomised controlled trial with blinded endpoint assessment, conducted at 77 hospitals in ten countries. We included patients aged 18 years or older with acute ischaemic stroke symptoms upon awakening, limb weakness, a National Institutes of Health Stroke Scale (NIHSS) score of 3 or higher or aphasia, a non-contrast CT examination of the head, and the ability to receive tenecteplase within 4·5 h of awakening. Patients were randomly assigned (1:1) to either a single intravenous bolus of tenecteplase 0·25 mg per kg of bodyweight (maximum 25 mg) or control (no thrombolysis) using a central, web-based, computer-generated randomisation schedule. Trained research personnel, who conducted telephone interviews at 90 days (follow-up), were masked to treatment allocation. Clinical assessments were performed on day 1 (at baseline) and day 7 of hospital admission (or at discharge, whichever occurred first). The primary outcome was functional outcome assessed by the modified Rankin Scale (mRS) at 90 days and analysed using ordinal logistic regression in the intention-to-treat population. This trial is registered with EudraCT (2014-000096-80), ClinicalTrials.gov (NCT03181360), and ISRCTN (10601890).

FINDINGS

From June 12, 2017, to Sept 30, 2021, 578 of the required 600 patients were enrolled (288 randomly assigned to the tenecteplase group and 290 to the control group [intention-to-treat population]). The median age of participants was 73·7 years (IQR 65·9-81·1). 332 (57%) of 578 participants were male and 246 (43%) were female. Treatment with tenecteplase was not associated with better functional outcome, according to mRS score at 90 days (adjusted OR 1·18, 95% CI 0·88-1·58; p=0·27). Mortality at 90 days did not significantly differ between treatment groups (28 [10%] patients in the tenecteplase group and 23 [8%] in the control group; adjusted HR 1·29, 95% CI 0·74-2·26; p=0·37). Symptomatic intracranial haemorrhage occurred in six (2%) patients in the tenecteplase group versus three (1%) in the control group (adjusted OR 2·17, 95% CI 0·53-8·87; p=0·28), whereas any intracranial haemorrhage occurred in 33 (11%) versus 30 (10%) patients (adjusted OR 1·14, 0·67-1·94; p=0·64).

INTERPRETATION

In patients with wake-up stroke selected with non-contrast CT, treatment with tenecteplase was not associated with better functional outcome at 90 days. The number of symptomatic haemorrhages and any intracranial haemorrhages in both treatment groups was similar to findings from previous trials of wake-up stroke patients selected using advanced imaging. Current evidence does not support treatment with tenecteplase in patients selected with non-contrast CT.

FUNDING

Norwegian Clinical Research Therapy in the Specialist Health Services Programme, the Swiss Heart Foundation, the British Heart Foundation, and the Norwegian National Association for Public Health.

Proton pump inhibitor use and the risk of peritoneal dialysis associated peritonitis

BACKGROUND

The use of proton-pump inhibitors (PPI) has been associated with an increased risk of developing spontaneous bacterial peritonitis in patients with cirrhosis. Whether PPI use confers a similar risk in developing peritonitis in peritoneal dialysis (PD) patients remains unclear.

METHODS

Patients on PD were retrospectively identified. Data such as PPI use during PD, underlying diagnoses, comorbidities, and baseline serum tests were collected. Univariable and multivariable analysis was conducted using logistic regression to assess whether PPI use and other factors were associated with PD peritonitis.

RESULTS

57 patients were identified with a median(interquartile range(IQR)) age of 65.0(51.5-74.0) years. The median(IQR) time on PD was 29.0(17.5-45.0) months. 28 patients were on a PPI during PD. 57% of the PPI group went on to develop peritonitis, compared to 31% of patients without PPI exposure (OR=2.96, 95% CI:[1.00, 8.78], p=0.050). Months on PD (OR=1.03, 95% CI:[1.00, 1.06], p=0.026), serum urea (OR=0.88, 95% CI:[0.80, 0.97], p=0.017), congestive cardiac failure (OR=5.44, 95% CI:[1.29, 23.00], p=0.021) and renovascular disease (OR=14.59, 95% CI:[1.68, 126.67], p=0.015) were identified as possible risk factors for peritonitis on univariable analysis. Following adjustment for covariates, serum urea, but not PPI use, was associated with PD peritonitis (OR=0.87, 95% CI:[0.78,0.98], p=0.020).

CONCLUSION

PPI use during PD was not associated with peritonitis. Due to the small number of patients and the limited number of studies investigating the effect of PPI use on PD peritonitis, further research is needed. This article is protected by copyright. All rights reserved.

Abstract PO009: Epigenetic silencing by SETDB1 represses tumor-cell intrinsic immunogenicity

Epigenetic alterations are defining features of many tumor types and have recently been implicated in tumor immunity. However, the epigenetic mechanisms that mediate immune sensitivity or resistance in cancer cells are poorly characterized. To systematically identify epigenetic regulators of immune evasion in cancer, we performed in vivo loss of function CRISPR screens against 936 chromatin regulator genes in syngeneic murine tumor models treated with immune checkpoint blockade. These screens identified SETDB1, an H3K9-methyltransferase, and associated members of the HUSH and KAP1 complexes as intrinsic mediators of immune evasion in cancer cells. We also found that amplification of SETDB1 (1q21) in certain human tumors is associated with immune exclusion and resistance to immune checkpoint blockade. Mechanistically, we find that SETDB1 targets broad domains, hundreds of kilobases in size, that are predominantly located within the open genome compartment “A” (i.e., euchromatin). These SETDB1 domains show strong enrichment for transposable elements (TEs) of the LTR family, and gene loci that arose through segmental duplication events, a key driver of mammalian genome evolution. Setdb1 KO derepresses latent regulatory elements at TEs within these regions and leads to the transcriptional up-regulation of nearby immune genes, including canonical stimulatory ligands of the NKG2D receptor. SETDB1 loss also triggers the activation of hundreds of TEs with the potential to encode retroviral proteins (Gag, Pol, Env), and promotes immune responses dependent on CD8+ T cells and tumor expression of MHC Class I. Our study establishes SETDB1 as an epigenetic checkpoint that represses intrinsic immunogenicity in cancer cells, and thus represents a novel target to enhance the efficacy and scope of immunotherapy.

Citation Format: Jingyi Wu, Arvin Iracheta-Vellve, James Patti, Jeffrey Hsu, Thomas Davis, Deborah Dele-Oni, Peter Du, Jeffrey Ishizuka, Sarah Kim, Susan Klaeger, Nelson Knudsen, Brian Miller, Tung Nguyen, Emily Robitschek, Emily Schneider, Margaret Zimmer, Jacob Jaffe, John Doench, W. Nicholas Haining, Kathleen Yates, Robert Manguso, Bradley Bernstein, Gabriel K. Griffin. Epigenetic silencing by SETDB1 represses tumor-cell intrinsic immunogenicity [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2020 Oct 19-20. Philadelphia (PA): AACR; Cancer Immunol Res 2021;9(2 Suppl):Abstract nr PO009.

Integrating nursing informatics into undergraduate nursing education in Africa: A scoping review

Background

Information and communication technologies have become omnipresent in healthcare systems globally, and since nurses comprise the majority of the health sector workforce, they are expected to be adequately skilled to work in a technology‐mediated environment. Integrating nursing informatics into undergraduate nursing education is a cornerstone to nursing education and practice in Africa.

Aim

This scoping review aimed to evidence the integration of nursing informatics into undergraduate nursing education in Africa.

Methods

A scoping review of the literature used electronic databases including CINAHL Plus databases; EmCare; MEDLINE Ovid; Scopus; ERIC ProQuest; Web of Science; Google; and Google Scholar to locate papers specific to the African context. From a total of 8723 articles, 19 were selected for critique and synthesis.

Results

Selected studies indicated that nursing students used several information and communication technologies tools primarily for academic purposes, and rarely for clinical practice. In Africa, the challenges for teaching informatics in nursing education included: limited information and communication technologies skills among faculty and students; poor teaching strategies; and a lack of standardization of nursing informatics competencies. Successful integration of nursing informatics into undergraduate nursing education in African countries depends on restructuring nursing informatics content and teaching strategies, capacity building of the faculty and students in information and communication technologies, political commitment, and collaborative partnership.

Conclusion

Nursing informatics is scarce in undergraduate nursing education in Africa due to the implementation and adoption challenges. Responding to these challenges requires a multi‐sectoral approach in the revision of undergraduate nursing curricula.

Implication for nursing education, practice, policy and research

This study highlights the importance of nursing informatics in undergraduate nursing education, with its challenges and success. Nursing education policies should support the development of well‐standardized nursing informatics content and appropriate teaching strategies to deliver it. Further research is needed to establish which aspects of nursing informatics are integrated into undergraduate nursing education and nursing practice, implementation process, challenges and possible solutions. Collaborative partnerships are vital to developing nursing informatics policies to better prepare graduate nurses for the African healthcare workforce in the digital era.

Abstract B47: CHIME screening identifies PTPN2 as a novel regulator of antitumor immunity

Despite the significant clinical responses observed with checkpoint blockade, there is an urgent need to identify new therapeutic targets in immune cells for combination therapies. However, the use of functional genomic approaches in immune cells to discover immunotherapy targets is limited by inefficient vector delivery or perturbation of cell states. To circumvent these limitations, we developed CHIME: CHimeric IMmune Editing, a bone marrow chimeric CRISPR-Cas9 delivery system, to rapidly evaluate gene function in innate and adaptive immune cells in vivo without prior ex vivo manipulation. This approach enables efficient deletion of genes of interest in major immune lineages without altering immune development or function. To discover novel immunotherapy targets we performed an in vivo pooled genetic screen for negative regulators of CD8+ T-cell responses to LCMV Clone 13 viral infection. We found that deletion of the phosphatase Ptpn2 enhances CD8+ T-cell responses to chronic pathogens and cancer. In models of both chronic viral infection and transplantable tumors, Ptpn2 null CD8+ T cells expand more and show increased expression of effector genes compared to wild-type cells. Consistent with this, in the LCMV Clone 13 model, Ptpn2 deletion in CD8+ T cells affects the differentiation and expansion of exhausted subpopulations by increasing IFN-I signaling. Furthermore, deletion of Ptpn2 in the immune system induces a CD8+ T cell-dependent clearance of tumors and synergizes with PD-1 immune checkpoint blockade. Our results suggest that therapeutic inhibition of Ptpn2 in immune cells may enhance CD8+ T-cell effector function and mediate antitumor immunity to improve tumor control. More generally, these findings suggest that this genetic platform can enable rapid target discovery through pooled loss-of-function screening in immune cell lineages in vivo and presents a novel target for potential immune based therapies.

Citation Format: Martin LaFleur, Thao Nguyen, Matthew Coxe, Brian Miller, Kathleen Yates, Jacob Gillis, Debattama Sen, John Doench, Nicholas Haining, Arlene Sharpe. CHIME screening identifies PTPN2 as a novel regulator of antitumor immunity [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2019 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(3 Suppl):Abstract nr B47.

9-O-acetyl sialic acid levels identify committed progenitors of plasmacytoid dendritic cells

The origins of plasmacytoid dendritic cells (pDCs) have long been controversial and progenitors exclusively committed to this lineage have not been described. We show here that the fate of hematopoietic progenitors is determined in part by their surface levels of 9-O-acetyl sialic acid. Pro-pDCs were identified as lineage negative 9-O-acetyl sialic acid low progenitors that lack myeloid and lymphoid potential but differentiate into pre-pDCs. The latter cells are also lineage negative, 9-O-acetyl sialic acid low cells but are exclusively committed to the pDC lineage. Levels of 9-O-acetyl sialic acid provide a distinct way to define progenitors and thus facilitate the study of hematopoietic differentiation.

PI3K activated tumors evade tumor immunity by promoting an inhibitory myeloid microenvironment

Oncogenes act in a cell-intrinsic way to promote tumorigenesis. Whether oncogenes also have a cell-extrinsic effect on suppressing the immune response to cancer is less well understood. Here we use an in vivo screen of known cancer-associated somatic mutations in immunocompetent mouse tumor models treated with checkpoint blockade to identify oncogenes that confer immune evasion. We found that a catalytically active mutation in Phospho-Inositol 3 Kinase (PI3K), PIK3CA c.3140A>G (H1047R) confers selective growth advantage after immunotherapy. Pharmacologic PI3K inhibition resensitizes mutant tumors to immunotherapy with anti-PD-1. The tumor microenvironment (TME) in PIK3CA H1047R-expressing tumors has fewer infiltrating CD8+ T cells after immunotherapy but is enriched for immune inhibitory myeloid cells. Inhibition of myeloid infiltration in PIK3CA H1047R tumors results in increased sensitivity to PD-1 checkpoint blockade. Thus PI3K has a role in tumor immune evasion mediated by establishment of an inhibitory myeloid microenvironment in addition to its well-described, cell-intrinsic oncogenic role. Activating mutations in PI3K may be useful as a biomarker of poor response to immunotherapy. More generally, our data suggest a rationale to combine PI3K inhibition with immunotherapy of PI3KCA mutant tumors.

Abstract 706: In vivo tumor-associated mutation screen identifies PI3K activation as a mechanism of resistance to PD-1 blockade

Known genomic correlates of response to immunotherapy do not perfectly predict clinical outcome, supporting the existence of unknown mechanisms of resistance to tumor immunity. We hypothesize that somatic, cancer-associated mutations account for heterogeneity in spontaneous response to tumors and response to immunotherapy. We have undertaken a systematic in vivo screen to identify mechanisms of resistance to tumor immunity in order to define a comprehensive set of therapeutic targets and provide biomarkers of sensitivity to immunotherapy. Mouse tumor cell lines (MC38 colon carcinoma or B16 melanoma) were engineered to express a library of barcoded open reading frames (ORFs) mutagenized to encode known cancer-associated somatic mutations. Tumor-bearing animals were treated with anti-PD-1. A mutation in Phospho-Inositol 3 Kinase (PI3K), PIK3CA c.3140A>G, increased in representation in anti-PD-1 treated tumors but not in immunodeficient animals, suggesting that activity of the mutant allele conferred selective growth advantage in the setting of tumor immunity. This mutation encodes a constitutively active mutant catalytic domain, PIK3CA H1047R. MC38 tumors homogeneously expressing H1047R and implanted into wild-type mice failed to respond to anti-PD-1 therapy, while tumors expressing a control gene regressed. Pharmacologic PI3K inhibition resensitized tumors to treatment with anti-PD-1. PD-1-treated PIK3CA H1047R tumors had fewer infiltrating CD8+ T cells as measured by immunohistochemistry and flow cytometry. Single-cell RNA-seq of tumor-infiltrating immune cells revealed a population of myeloid cells expressing known immune inhibitory proteins that differentially enriched in PIK3CA H1047R-expressing tumors. Our data suggest that PI3K has, in addition to its well-described oncogenic role, a role in tumor immune evasion mediated by establishment of an inhibitory myeloid microenvironment. As such, activating mutations in PI3K may be useful as a biomarker of poor response to immunotherapy, and these studies provide a rationale for therapeutic combination trials of PI3K inhibition with checkpoint blockade and other myeloid-targeting immunotherapies.

Citation Format: Natalie B. Collins, Brian C. Miller, Kevin Bi, Rose Al Abosy, Kathleen Yates, Yashaswi Shrestha, John Doench, Jesse Boehm, W Nicholas Haining. In vivo tumor-associated mutation screen identifies PI3K activation as a mechanism of resistance to PD-1 blockade [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 706.

CDK4/6 Inhibition Augments Antitumor Immunity by Enhancing T-cell Activation

Immune checkpoint blockade, exemplified by antibodies targeting the PD-1 receptor, can induce durable tumor regressions in some patients. To enhance the efficacy of existing immunotherapies, we screened for small molecules capable of increasing the activity of T cells suppressed by PD-1. Here, we show that short-term exposure to small-molecule inhibitors of cyclin-dependent kinases 4 and 6 (CDK4/6) significantly enhances T-cell activation, contributing to antitumor effects in vivo, due in part to the derepression of NFAT family proteins and their target genes, critical regulators of T-cell function. Although CDK4/6 inhibitors decrease T-cell proliferation, they increase tumor infiltration and activation of effector T cells. Moreover, CDK4/6 inhibition augments the response to PD-1 blockade in a novel ex vivo organotypic tumor spheroid culture system and in multiple in vivo murine syngeneic models, thereby providing a rationale for combining CDK4/6 inhibitors and immunotherapies.Significance: Our results define previously unrecognized immunomodulatory functions of CDK4/6 and suggest that combining CDK4/6 inhibitors with immune checkpoint blockade may increase treatment efficacy in patients. Furthermore, our study highlights the critical importance of identifying complementary strategies to improve the efficacy of immunotherapy for patients with cancer. Cancer Discov; 8(2); 216-33. ©2017 AACR.See related commentary by Balko and Sosman, p. 143See related article by Jenkins et al., p. 196This article is highlighted in the In This Issue feature, p. 127.

LCMV-specific CD4 T cells induce immunopathology and impair immune protection following chronic LCMV infection (VIR1P.1132)

CD4 T cells promote memory immune responses, but it is unclear whether vaccine-induced CD4 T cells contribute to immune protection. We interrogated if virus-specific CD4 T cells would protect mice against infection with chronic lymphocytic choriomeningitis virus (LCMV). Immunization with vaccines that induced CD4 T cell responses resulted in mortality following infection with persistent strains of LCMV. Immunopathology was associated with high levels of virus-specific CD4 T cells, generalized inflammation and collapse of adaptive immunity. Interestingly, virus-specific CD8 T cells or antibodies abrogated these lethal effects of CD4 T cell vaccines. Our data demonstrate the importance of tightly regulating CD4 T cell responses following vaccination, and suggest that CD4 T cells in the absence of effective antiviral immune responses could induce lethal immunopathology.

The kallikrein-kinin system in the kidney

To understand the role of the kallikrein-kinin system in the kidney all components of the system and their localization need to be considered. About half the kallikrein in urine occurs as the proenzyme which arises in the distal tubule. Kinins are formed in the distal tubule and collecting duct from urokinnogen which is found throughout the tubule. Urine contains about twice as much lysyl-brandykinin as bradykinin. A third kinin, methionyl-lysyl-bradykinin, also can occur in urine. It is probably produced by uropepsin as the kinin is largely formed in acidified urine and its formation is inhibited by pepstatin. The significance of the three kinins is unknown. Kinins are normally slowly (few hours) destroyed in urine. The importance of kallikrein, urokinogen and kininases in regulating the level of kinins needs to be determined.

Isolation of RNA and the synthesis and amplification of cDNA from antigen-specific T cells for genome-wide expression analysis

Genome-wide gene expression analysis has become a very powerful routine tool for the study of distinct differentiation states. However, the examination of total populations of cells that contain high levels of heterogeneity, such as the total CD8(+) T cell population during an immune response, is limited because that complexity hampers accurate interpretation. The gene expression signatures from populations represent the average of all cells within the populations, which will smooth out large expression changes within small subpopulations and virtually eliminate any small changes. However, small expression changes within a minor subpopulation, such as antigen-specific CD8(+) T cells responding to an infection, can have relevant biological consequences. Although very limited amounts of RNA can be isolated from small subpopulations of cells, there are now methods to synthesize and amplify cDNA from this limited RNA in sufficient quantities needed for microarray analysis. Here, we describe a complete protocol to extract RNA from small numbers of cells, synthesize cDNA from that RNA, and amplify that cDNA in an unbiased method. This protocol is a useful tool for the study of genome-wide expression signatures from many of the subpopulations that are numerically small but important in immune responses and homeostasis.

Propagation of a laser-driven relativistic electron beam inside a solid dielectric

Laser probe diagnostics: shadowgraphy, interferometry, and polarimetry were used for a comprehensive characterization of ionization wave dynamics inside a glass target induced by a laser-driven, relativistic electron beam. Experiments were done using the 50-TW Leopard laser at the University of Nevada, Reno. We show that for a laser flux of ∼2 × 10(18) W/cm2 a hemispherical ionization wave propagates at c/3 for 10 ps and has a smooth electron-density distribution. The maximum free-electron density inside the glass target is ∼2 × 10(19) cm-3, which corresponds to an ionization level of ∼0.1%. Magnetic fields and electric fields do not exceed ∼15 kG and ∼1 MV/cm, respectively. The electron temperature has a hot, ringlike structure with a maximum of ∼0.7 eV. The topology of the interference phase shift shows the signature of the "fountain effect", a narrow electron beam that fans out from the propagation axis and heads back to the target surface. Two-dimensional particle-in-cell (PIC) computer simulations demonstrate radial spreading of fast electrons by self-consistent electrostatic fields driven by laser. The very low ionization observed after the laser heating pulse suggests a fast recombination on the sub-ps time scale.

Geographic variation in tissue accumulation of endocrine disrupting compounds (EDCs) in grazing sheep

Muscle tissue was collected from ewes and lambs derived from farms throughout Scotland and sample concentrations of five endocrine disrupting compound groups were determined. Farms of origin were categorised according to geographic region. There were few statistically-significant differences with region or distance from cities. However, the magnitude of the difference between the highest and lowest mean values in ewe muscle from different regions exceeded 30% for 13 of the 15 compounds that were consistently detected in muscle, with animals derived from the industrialised region having the highest mean values for 11 of the 13 compounds. A less marked trend was apparent in the lamb muscle (8 of 13 highest were in the industrialised region). The physiological effects of such small differences in exposure to mixtures of pollutants remain to be determined.

Outcome of children with neuromuscular disease admitted to paediatric intensive care

AIMS

To determine the outcome of children with neuromuscular disease (NMD) following admission to a tertiary referral paediatric intensive care (PICU).

METHODS

All children with chronic NMD whose first PICU admission was between July 1986 and June 2001 were followed up from their first PICU admission to time of study. The outcomes recorded were death in or outside of PICU, duration of PICU admission, artificial ventilation during admission and following discharge from PICU, and readmission to PICU.

RESULTS

Over 15 years, 28 children were admitted on 69 occasions. Sixteen (57%) children had more than one admission. The median duration of PICU admission was 4 days (range 0.5-42). Twenty three per cent of unplanned admissions resulted in the commencement of respiratory support that was continued after discharge from the PICU. Severity of functional impairment was not associated with longer duration of stay or higher PRISM scores. Ten children (36%) died, with four (14%) deaths in the PICU. A higher proportion of children with severe limitation of function were among children that died compared to survivors.

CONCLUSION

Most children with NMD admitted to the PICU recover and are discharged without the need for prolonged invasive ventilation. However, in this group of children, the use of non-invasive home based ventilation is common and they are likely to require further PICU admission.

Sequence changes in the human adenovirus type 5 DNA polymerase associated with resistance to the broad spectrum antiviral cidofovir

Although there is currently no FDA approved antiviral treatment for adenovirus (Ad) infections, the broad spectrum antiviral cidofovir (CDV) has demonstrated potent inhibitory activity against many Ad serotypes in vitro and in an in vivo ocular replication model. The clinical potential of CDV prompted the assessment for the emergence of CDV resistance in Ad5. Serial passage of Ad5 in increasing concentrations of CDV resulted in derivation of four different Ad5 variants with increased resistance to CDV. CDV resistance was demonstrated by ability to replicate viral DNA in infected cells at CDV concentrations that inhibit the parental virus, by ability to form plaques in CDV concentrations of >20 microg/ml and by increased progeny release following infection and growth in media containing CDV. Using marker rescue, the loci for CDV resistance in variant R1 was shown to be mediated by one residue change L741S, one of two mutations within the R1 encoded DNA polymerase. The CDV-resistant variants R4, R5 and R6 also contained mutations in their respective DNA polymerase sequences, but these were different from R1; variant R4 contained two changes (F740I and V180I), whereas both R5 and R6 variants contained the non-conserved mutation A359E. R6 contained additional alterations L554F and V817L. The location of the R1 change is close to a region of the DNA polymerase which is conserved with other polymerases that is predicted to involve nucleotide binding.

A managed behavioral health organization operated by an academic psychiatry department

As a means of adapting to managed care, the psychiatry department at Wake Forest University developed a managed behavioral health organization (MBHO) to manage the care of enrollees in QualChoice, the health maintenance organization of the Wake Forest University Baptist Medical Center. Before the academic MBHO was created, care was managed by a for-profit MBHO. In this case study, financial and utilization data were obtained from both MBHOs and from QualChoice. The data confirm that the academic MBHO was able to offer competitive rates for its services. It also was able to increase enrollees' use of the medical center's own providers and facilities by making more referrals than were made by the for-profit MBHO. Developing a managed behavioral health organization can allow academic psychiatry departments, either individually or as consortia, to preserve the patient base they require for teaching, research, and financial stability.

Service use and financial performance in a replication program on adult day centers

The authors describe results from Partners in Caregiving: The Dementia Services Program, and present information on service utilization and financial performance among a group of 48 adult day centers across the United States from 1992 to 1996. Centers, with nonrandom assignment, received either grant support (average value: $93,000) or intensive technical assistance (average value: $39,000). Sites reported baseline data and submitted utilization information (enrollment and census) and financial data (revenue and expenses) quarterly. Overall, there were significant increases in enrollment, census, and financial performance (percent of cash expenses met through operating revenue) over the 4-year period. The grant-supported and technical-assistance sites had similar rates of improvement. Results provide data on service utilization and financial performance and demonstrate gains that can be achieved in these areas through improved marketing and financial management.

Glycerol hyperhydration improves cycle time trial performance in hot humid conditions

Eight competitive cyclists [mean peak oxygen consumption, (VO2(peak)) = 65 ml x min(-1) x kg(-1)] undertook two 60-min cycle ergometer time trials at 32 degrees C and 60% relative humidity. The time trials were split into two 30-min phases: a fixed-workload phase and a variable-workload phase. Each trial was preceded by ingestion of either a glycerol solution [1 g x kg(-1) body mass (BM) in a diluted carbohydrate (CHO)-electrolyte drink] or a placebo of equal volume (the diluted CHO-electrolyte drink). The total fluid intake in each trial was 22 ml x kg(-1) BM. A repeated-measures, double blind, cross over design with respect to glycerol was employed. Glycerol ingestion expanded body water by approximately 600 ml over the placebo treatment. Glycerol treatment significantly increased performance by 5% compared with the placebo group, as assessed by total work in the variable-workload phase (P < 0.04). There were no significant differences in rectal temperature, sweat rate or cardiac frequency between trials. Data indicate that the glycerol-induced performance increase did not result from plasma volume expansion and subsequently lower core temperature or lower cardiac frequencies at a given power output as previously proposed. However, during the glycerol trial, subjects maintained a higher power output without increased perception of effort or thermal strain.

Cardiovascular and respiratory effects of endothelin in the ventrolateral medulla of the normotensive rat

We studied the relevance of the ventrolateral medulla for the cardiovascular and respiratory effects of endothelin-1 in urethane-anesthetized rats. Microinjection of endothelin-1 into the rostral ventrolateral medulla (RVLM) evoked pressor and bradycardic effects followed by sustained decreases in blood pressure, bradycardia, and respiratory depression. These effects were inhibited by endothelin-A receptor antagonists (BQ-123 and BQ-610) but not by endothelin-B antagonists. In the caudal ventrolateral medulla (CVLM) endothelin-1 decreased blood pressure, renal sympathetic nerve activity, respiratory frequency, and phrenic nerve activity, whereas heart rate increased. Pretreatment with BQ-123 in the CVLM increased respiratory frequency by 15 +/- 6 breaths per minute and prevented the effects of intra-CVLM administration of endothelin-1. In separate experiments, the intracisternal administration of endothelin-1 (20 pmol) to rats pretreated with saline in both RVLM and CVLM resulted in a hypotensive and bradycardic phase that was followed by hypertension (50 +/- 15 mm Hg), bradycardia, and 100% mortality. In a separate group, pretreatment with BQ-123 in the RVLM and CVLM completely inhibited the hypotensive phase and reduced by 83% the subsequent rise in blood pressure evoked by endothelin-1. Cardiorespiratory arrest was prevented in all the rats in this group. Selective endothelin receptor blockade in the RVLM attenuated the hypertensive period of intracisternal administration of endothelin-1 and prevented mortality by 33%, whereas in the CVLM the endothelin receptor antagonist inhibited the initial hypotension and reduced mortality by 25%. Our results support the concept that in the ventral medulla, endothelin-1 can modulate cardiovascular and respiratory function.

Effects of two caregiver-training programs on burden and attitude toward help

The purpose of this research was to determine which caregiver-training program (CTP) was most beneficial to caregivers. Two types of CTPs, a behavior management program and a social skills program, were implemented. The effects of the CTPs on attitude toward asking for help, attitude about using adult day care, are caregiving burden were explored. Thirty-three caregivers volunteered to participate. Of the caregivers, the majority were female spouses (n = 22), 76% were over age 60, and 68% had some college education. Subjects were randomly assigned to one of two CTPs or a control group. Pretest was completed during the first phase of the training program. Both CTPs met for six sessions. The control group received no training. The posttest was conducted 1 month after completion of the CTPs. Differences between the three groups were analyzed by using ANOVA. No differences were observed between groups. Six of the subjects chose the alternate training program when given the opportunity for further training. Caregivers who participated in both CTPs experienced a decrease in objective burden and a more positive attitude toward asking for help and using adult day care.

Massive transfusion: outcome in blunt trauma patients

Over a 54-month period 6,142 patients were consecutively admitted to our Level I trauma center. Ninety-two blunt trauma patients required massive transfusion (MT) of 20 or more units of packed red blood cells (range, 20-126). Eighty-two per cent of all transfused blood was given within 24 hours of admission. Forty-eight patients (52%) were long-term survivors. Twenty-six patients died (28%) within 24 hours and 21 of these exsanguinated. Eighteen patients died greater than 24 hours: nine (50%) died from multiple organ failure, and nine (50%) died from severe closed head injury (CHI). Clinical predictors of increased mortality were: shock on admission, closed head injury, and age. Forty-three survivors were followed for a mean of 2.5 years (range, 1-5 years). No patient died during followup. All patients were home at 1 year; only four patients required continued medical assistance. Thirty-two patients (74%) returned to work. We conclude that: 1) blunt and penetrating trauma patients receiving MT have similar survival rates of 50%; 2) shock, closed head injury, and age predict increased mortality but do not preclude survival; 3) long-term outcome in blunt patients requiring MT is excellent. Post-discharge death is rare and 3/4 of the survivors return to work, justifying the high cost of acute care.

A cascading development model for amphibian embryos

The mesodermal tissue of some amphibian gastrula develops into a dorsal-to-ventral sequence of notochord, somite, pronephros, and lateral plate cell types. The cellular proportions regulate with respect to embryo size. The dorsal blastoporal lip appears to function as an organizer for the embryo. The transplantation of a donor lip to the ventral side of a host causes a second, opposed embryo to form and the system commits similar total proportions of cells as do normally developing embryos. Transplantation of donor somite to the ventral side of a host causes a reduction in the proportion of host somite developed. A modified reaction-diffusion system governing embryo development is proposed. Developmental simulations consistent with experimental observations are presented and analyzed. The results suggest that the degree of somite inhibition is positively correlated with the size of the somite transplant. Further predictions are that sufficiently large somite transplants would induce ectopic, ventral pronephros to form and ventral pronephros transplants would inhibit host pronephros development.

Serum cholesterol and coronary heart disease: Auckland general practitioners' attitudes and practices in 1986

The relationship between elevated serum cholesterol and coronary heart disease, is now generally accepted as being causal. To examine current attitudes and practices regarding the treatment of high serum cholesterol, questionnaires were sent to a randomly selected sample of general practitioners in the Takapuna health district during 1986. The response rate among the 92 doctors in general practice at the time of the study was 80%. The majority of general practitioners (82.5%) believed that there was a casual relationship between high serum cholesterol and coronary heart disease and that reducing levels would help prevent coronary heart disease. Almost all general practitioners (96%) were screening some groups of patients for high serum cholesterol, with most screening those with symptomatic coronary heart disease or associated risk factors, and 15% screening all patients. Although almost 90% of general practitioners had patients on diet therapy and one third had patients on drug treatment, there was wide variation in attitudes regarding the serum cholesterol levels meriting dietary or drug treatment. This suggests that there is still considerable confusion as to when and how to treat high cholesterol levels and that specific national guidelines for the detection and management of high serum cholesterol are required as part of a comprehensive programme to prevent coronary heart disease.

Kinetics of the Nitrosation of Pyrrolidine and Proline

The kinetics of the nitrosation of pyrrolidine and proline have been investigated in buffer solutions of mildly acidic pH's in the temperature range 40–100 °C. The rate constants were determined and the enthalpy and the entropy of activation were calculated for both reactions. Examples are presented in which are estimated the maximum amounts of nitroso compounds formed under conditions relevant to meat processing.