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Positron emission tomography (PET) reporter genes allow noninvasive whole-body imaging of transplanted cells by detection with radiolabeled probes. We used a human deoxycytidine kinase containing three amino acid substitutions within the active site (hdCK3mut) as a reporter gene in combination with the PET probe [(18)F]-L-FMAU (1-(2-deoxy-2-(18)fluoro-β-L-arabinofuranosyl)-5-methyluracil) to monitor models of mouse and human hematopoietic stem cell (HSC) transplantation. These mutations in hdCK3mut expanded the substrate capacity allowing for reporter-specific detection with a thymidine analog probe. Measurements of long-term engrafted cells (up to 32 wk) demonstrated that hdCK3mut expression is maintained in vivo with no counter selection against reporter-labeled cells. Reporter cells retained equivalent engraftment and differentiation capacity being detected in all major hematopoietic lineages and tissues. This reporter gene and probe should be applicable to noninvasively monitor therapeutic cell transplants in multiple tissues.

Unlabelled: Unlike many cancers that exhibit glycolytic metabolism, high-grade liposarcomas often exhibit low 2[18F]fluoro-2-deoxy-D-glucose uptake by positron emission tomography (PET), despite rapid tumor growth. Here, we used liquid chromatography tandem mass spectrometry to identify carbon sources taken up by liposarcoma cell lines derived from xenograft tumors in patients. Interestingly, we found that liposarcoma cell lines consume nucleosides from culture media, suggesting nucleoside salvage pathway activity. The nucleoside salvage pathway is dependent on deoxycytidine kinase (dCK) and can be imaged in vivo by PET with 1-(2'-deoxy-2'-[18F]fluoroarabinofuranosyl) cytosine (FAC). We found that liposarcoma cell lines and xenograft tumors exhibit dCK activity and dCK-dependent FAC uptake in vitro and in vivo. In addition, liposarcoma cell lines and xenograft tumors are sensitive to treatment with the nucleoside analogue prodrug gemcitabine, and gemcitabine sensitivity is dependent on dCK expression. Elevated dCK activity is evident in 7 of 68 clinical liposarcoma samples analyzed. These data suggest that a subpopulation of liposarcoma patients have tumors with nucleoside salvage pathway activity that can be identified noninvasively using [18F]-FAC-PET and targeted using gemcitabine., Significance: Patients with high-grade liposarcoma have poor prognoses and often fail to respond to chemotherapy. This report identifies elevated nucleoside salvage activity in a subset of liposarcomas that are identifiable using noninvasive PET imaging with FAC and that are sensitive to gemcitabine. Thus, we suggest a new treatment paradigm for liposarcoma patients that uses [18F]-FAC-PET in the clinic to delineate gemcitabine responders from nonresponders., (©2012 AACR.)

The steroid hormone signaling axis is thought to play a central role in initiation and progression of many hormonally regulated epithelial tumors. It is unclear whether all cancer-initiating signals depend on an intact hormone receptor signaling machinery. To ascertain whether cell autonomous androgen receptor (AR) is essential for initiation of prostate intraepithelial neoplasia (PIN), the response of AR-null prostate epithelia to paracrine and cell autonomous oncogenic signals was assessed in vivo by using the prostate regeneration model system. Epithelial-specific loss of AR blocked paracrine FGF10-induced PIN, whereas the add back of exogenous AR restored this response. In contrast, PIN initiated by cell-autonomous, chronic-activated AKT developed independent of epithelial AR signaling. Our findings demonstrate a selective role for AR in the initiation of PIN, dependent on the signaling pathways driving tumor formation. Insights into the role of hormone receptor signaling in the initiation of epithelial tumors may help define this axis as a target for chemoprevention of carcinomas.

Clinical tools that measure changes in immune cell metabolism would improve the diagnosis and treatment of immune dysfunction. PET, utilizing probes for specific metabolic processes, detects regions of immune activation in vivo. In this study we investigated the immune cell specificity of PET probes for two different metabolic pathways: [18F]-2-fluorodeoxyglucose ([18F]-FDG) for glycolysis and [18F]-2-fluoro-D-(arabinofuranosyl)cytosine ([18F]-FAC) for deoxycytidine salvage. We isolated innate and adaptive immune cells from tissues of mice challenged with a retrovirus-induced sarcoma and measured their ability to accumulate FDG and FAC. We determined that the two probes had distinct patterns of accumulation: FDG accumulated to the highest levels in innate immune cells, while FAC accumulated predominantly in CD8+ T cells in a manner that correlated with cellular proliferation. This study demonstrates that innate and adaptive cell types differ in glycolytic and deoxycytidine salvage demands during an immune response and that these differential metabolic requirements can be detected with specific PET probes. Our findings have implications for the interpretation of clinical PET scans that use [18F]-FDG or [18F]-FAC to assess immune function in vivo and suggest potential applications of metabolic PET to monitor the effects of targeted immune modulation.

Background & Aims: Uptake of [18F]1-(2'-deoxy-2'-arabinofuranosyl)cytosine (D-FAC) is a trait of activated lymphocytes; its biodistribution predominates in the spleen, thymus, and bone marrow. In addition, D-FAC is taken up at high levels by the intestine. We analyzed the regional specificity of uptake and cell types that mediate it., Methods: In mice, 3-dimensional isocontour regions of interest were drawn based on computed tomographic images to quantify intestinal signals from micro-positron emission tomography scans. To ascertain the cell type responsible, intestinal epithelium and immune cells were isolated and D-FAC uptake was analyzed in vitro. Mice deficient in mucosal homing (beta7 integrin-/-), enteric microbiota (germ-free), or active for immune colitis (G alpha i2-/- CD3+ transferred into Rag-/- recipients) were studied., Results: Strong uptake of D-FAC was detected throughout the intestine, with greatest signal per region of interest in the duodenum. Fractionation of intestinal cell types after in vivo uptake revealed that the signal was almost entirely from epithelial cells. Among resident immune cell types, CD4+ T cells showed the greatest per-cell and total uptake. D-FAC uptake increased in both intestinal and systemic lymphoid sites during colitis. Compared with fluorodeoxyglucose, increased uptake of D-FAC in the small and large intestine occurred at an earlier stage of disease development., Conclusions: Uptake of D-FAC is a prominent trait of normal mouse intestinal epithelial cells, which is useful for their noninvasive visualization by positron emission tomography. Increased uptake of D-FAC reflects the activity of the epithelium and lymphocytes, providing a unique early marker of intestinal inflammation., (2010 AGA Institute. Published by Elsevier Inc. All rights reserved.)

T-cell death-associated gene 8 (TDAG8) is a G-protein-coupled receptor transcriptionally upregulated by glucocorticoids (GCs) and implicated by overexpression studies in psychosine-mediated inhibition of cytokinesis and in GC-induced apoptosis. To examine the physiological function of TDAG8, we generated knockout (KO) mice by homologous recombination. An enhanced green fluorescent protein reporter was knocked into the disrupted tdag8 locus to allow the analysis of TDAG8 expression in living cells. Interestingly, we found that during thymocyte development, TDAG8 expression resembled the dynamic regulation described for known modulators of GC-induced apoptosis, including Bcl-2, Notch1, and GC receptor. TDAG8 was expressed in double-negative cells, was downregulated at the double-positive transition, and was upregulated in single-positive thymocytes. However, despite this striking expression pattern, maturation and selection of thymocytes, as well as major immune functions, were not affected in TDAG8 KO mice. In contrast to previous overexpression results, TDAG8 was dispensable for psychosine-induced formation of multinucleated cells. Furthermore, TDAG8 KO thymocytes showed normal apoptosis following in vivo and in vitro GC treatment. These results, while establishing a useful reporter strain to study T-lymphocyte maturation, argue against a critical role for TDAG8 in immune development, psychosine-mediated inhibition of cytokinesis, and GC-induced cell death.

Intracellular trafficking and spatial dynamics of membrane receptors critically regulate receptor function. Using microscopic and subcellular fractionation analysis, we studied the localization of the murine G protein-coupled receptor G2A (muG2A). Evaluating green fluorescent protein-tagged, exogenously expressed as well as the endogenous muG2A, we observed that this receptor was spontaneously internalized and accumulated in endosomal compartments, whereas its surface expression was enhanced and stabilized by lysophosphatidylcholine (LPC) treatment. Monensin, a general inhibitor of recycling pathways, blocked LPC-regulated surface localization of muG2A as well as muG2A-dependent extracellular signal-regulated kinase (ERK) activation and cell migration induced by LPC treatment. Mutation of the conserved DRY motif (R-->A) enhanced the surface expression of muG2A, resulting in its resistance to monensin inhibition of ERK activation. Our data suggest that intracellular sequestration and surface expression regulated by LPC, rather than direct agonistic activity control the signaling responses of murine G2A toward LPC.

Neurofibromatosis type 1 (NF1) is often mentioned among the heritable connective tissue disorders associated with intracranial aneurysms, but the association has not been firmly established. We therefore reviewed a contemporary series of hospitalized patients with NF1, many of whom underwent brain magnetic resonance imaging (MRI). We identified patients with NF1 who were hospitalized at Cedars-Sinai Medical Center, Los Angeles, California, between January 1, 1997 and December 31, 2001 through the hospital's centralized medical records system using DRG codes. The mean age of the 39 patients was 30.4 years, and 22 patients had undergone MRI of the brain for the evaluation of symptoms due to the presence of central or peripheral nervous system tumors. Incidental intracranial aneurysms were detected in 2 (5%) of the 39 patients. Limiting the patient population to the 22 patients who had undergone MRI examination, the detection rate was 9%. This was significantly (P < 0.005) higher than the aneurysm detection rate in a control population (0/526 [0%]) of patients hospitalized for primary or secondary brain tumors, all of whom had undergone MRI examination. Our study suggests that patients with NF1 are at an increased risk of developing intracranial aneurysms.

G2A is a G-protein-coupled receptor (GPCR) involved in immune regulation. Previous studies have shown that lysophosphatidylcholine (LPC), a bioactive lipid associated with atherosclerosis and autoimmunity, acts through G2A to induce diverse biologic effects. Production of LPC during cell apoptosis serves as a chemotactic signal for macrophage recruitment. Here we demonstrate that macrophage chemotaxis to LPC is dependent on G2A function. Wild-type but not G2A-deficient mouse peritoneal macrophages migrated toward LPC. RNAi-mediated knockdown of G2A in J774A.1 macrophages abolished LPC-induced chemotaxis, whereas overexpression of G2A significantly enhanced this process. Mutation of the conserved DRY motif of G2A resulted in loss of chemotaxis to LPC, suggesting a requirement for G-protein signaling. Unlike most GPCRs, including the chemokine receptors, coupling to G(i) is not required for LPC/G2A-mediated chemotaxis, but coupling to G(q/11) and G(12/13) is necessary as judged by inhibition with dominant negative forms of these alpha subunits or with regulators of G-protein signaling (RGS) constructs. Collectively, these data establish that pertussis toxin-insensitive G2A signaling regulates macrophage chemotaxis to LPC. Defects in this signaling pathway may be related to the pathogenesis of systemic autoimmune disease.

We examined the racial distribution of subarachnoid hemorrhage (SAH) mortality in a unique multiracial community. Mortality rates for SAH among the residents of Los Angeles County were calculated from death certificate data (1985-1998). Residential postal zones were classified into three strata as a measure of socioeconomic status. The number of SAH deaths was 2,897. The age-adjusted SAH mortality rate was 1.9 in whites, 2.7 in Hispanics, 3.0 in Asians and 3.7 in blacks. In those younger than 70 years of age, the SAH mortality rate among blacks was 2.2 times that of whites and 1.8 times that of Hispanics and Asians. The SAH mortality rate declines after age 70 in blacks. The SAH mortality rate was higher in women than in men in all races and it was highest in elderly Asian women (23.5 per 100,000). An inverse relationship was observed between income and SAH mortality rates in all racial groups except whites., (2004 S. Karger AG, Basel)

Loss of function of Bruton's tyrosine kinase (Btk) causes X-linked agammaglobulinemia (XLA) in humans and X-linked immunodeficiency in mice (xid). By using MS analysis and phosphopeptide-specific antibodies, we identified a tyrosine phosphorylation site (Y617) near the carboxyl terminus of the Btk domain from Btk expressed in 293T as well as DT-40 cells. Y617 is conserved in all Tec family kinases except murine Tec. Replacement of Y617 with a negatively charged glutamic acid (E) suppressed Btk-mediated phospholipase Cgamma2 activation and calcium response in DT-40 cells, whereas Akt activation was not affected. The Btk Y617E mutant could partially restore conventional B cell development and proliferation in Btk(-)/Tec(-) mice but failed to rescue CD5(+) B-1 cell development and the TI-II immune response to 2,4,6,-trinitrophenyl-Ficoll. These data suggest that Y617 phosphorylation or a negative charge at this site may down-regulate the function of Btk by selectively suppressing the B cell calcium signaling pathway.

G2A is an immunoregulatory G protein-coupled receptor predominantly expressed in lymphocytes and macrophages. Ectopic overexpression studies have implicated G2A as a receptor for the bioactive lysophospholipid, lysophosphatidylcholine (LPC). However, the functional consequences of LPC-G2A interaction at physiological levels of receptor expression, and in a cellular context relevant to its immunological role, remain largely unknown. Here, we show impaired chemotaxis to LPC of a T lymphoid cell line in which G2A expression was chronically down-regulated by RNA interference technology. Rescuing this phenotype by reconstitution of the physiological level of receptor expression further supports a functional connection between LPC-G2A interaction and cellular motility. Overexpression of G2A in the T lymphoid cell line significantly enhanced chemotaxis to LPC. It also modified migration toward the LPC-related molecule, lysophosphatidic acid, indicating the possibility of crosstalk between G2A and endogenous lysophosphatidic acid receptors. The role of G2A in LPC-mediated cell migration may be relevant to the autoimmune syndrome associated with genetic inactivation of this G protein-coupled receptor in mice. The experimental system described here can be useful for understanding the structural requirements for LPC recognition by G2A and the signaling pathways regulated by this ligand-receptor pair.

Object: Intracranial hypotension due to a spontaneous spinal cerebrospinal fluid (CSF) leak is an increasingly recognized cause of postural headaches, but reliable follow-up data are lacking. The authors undertook a study to determine the risk of a recurrent spontaneous spinal CSF leak., Methods: The patient population consisted of a consecutive group of 18 patients who had been evaluated for consideration of surgical repair of a spontaneous spinal CSF leak. The mean age of the 15 women and three men was 38 years (range 22-55 years). The mean duration of follow up was 36 months (range 6-132 months). The total follow-up time was 654 months. A recurrent spinal CSF leak was defined on the basis of computerized tomography myelography evidence of a CSF leak in a previously visualized but unaffected spinal location. Five patients (28%) developed a recurrent spinal CSF leak; the mean age of these four women and one man was 36 years. A recurrent CSF leak developed in five (38%) of 13 patients who had undergone surgical CSF leak repair, compared with none (0%) of five patients who had been treated non-surgically (p = 0.249). The recurrent leak occurred between 10 and 77 months after the initial CSF leak, but within 2 or 3 months of successful surgical repair of the leak in all patients., Conclusions: Recurrent spontaneous spinal CSF leaks are not rare, and the recent successful repair of such a leak at another site may be an important risk factor.

Differential gene expression in tumors often involves growth factors and extracellular matrix/basement membrane components. Here, 11,000- gene microarray was used to identify gene expression profiles in brain tumors including high-grade gliomas [glioblastoma multiforme (GBM) and anaplastic astrocytoma], low-grade astrocytomas, or benign extra-axial brain tumors (meningioma) in comparison with normal brain tissue. Histologically normal tissues adjacent to GBMs were also studied. All GBMs studied overexpressed 14 known genes compared with normal human brain tissue. Overexpressed genes belonged to two broad groups: (a) growth factor-related genes; and (b) structural/extracellular matrix-related genes. For most of these 14 genes, expression levels were lower in low-grade astrocytoma than in GBM and were barely detectable in normal brain. Despite normal-appearing histology, gene expression patterns of tissues immediately adjacent to GBM were similar to those of their respective primary GBMs. Two genes were consistently up-regulated in both high-grade and low-grade gliomas, as well as in histologically normal tissues adjacent to GBMs. These genes coded for the epidermal growth factor receptor (previously reported to be overexpressed in gliomas) and for the alpha4 chain of laminin, a major blood vessel basement membrane component. Changes in expression of this laminin chain have not been previously associated with malignant tumors. Overexpression of laminin alpha4 chain in GBM and astrocytoma grade II by gene microarray analysis was confirmed by semiquantitive reverse transcription-PCR and immunohistochemistry. Importantly, an alpha4 chain-containing laminin isoform, laminin-8 (alpha4beta1gamma1), was expressed mainly in blood vessel walls of GBMs and histologically normal tissues adjacent to GBMs, whereas another alpha4 chain-containing laminin isoform, laminin-9 (alpha4beta2gamma1), was expressed mainly in blood vessel walls of low-grade tumors and normal brain. GBMs that overexpressed laminin-8 had a shorter mean time to tumor recurrence (4.3 months) than GBMs with overexpression of laminin-9 (9.7 months, P = 0.0007). Up-regulation of alpha4 chain-containing laminins could be important for the development of glioma-induced neovascularization and glial tumor progression. Overexpression of laminin-8 may be predictive of glioma recurrence.

Objective: The purpose of this study was to evaluate gender differences in quality of life (QOL) in a large sample of age-matched and ejection fraction (EF)-matched patients with heart failure., Design: Matched comparisons of secondary data were used., Setting: The setting consisted of multicenter Studies of Left Ventricular Dysfunction trials., Sample: The sample included 1382 patients (691 men and 691 women) who were age-matched and EF-matched., Outcome Measures: Global QOL and the QOL dimensions of physical function, emotional distress, social health, and general health were measured using the Ladder of Life, items from the Profile of Mood States Inventory, the Functional Status Questionnaire, the beta-Blocker Heart Attack Trial instrument, and an item from the RAND Medical Outcomes Study instrument., Results: Women had significantly worse general life satisfaction, physical function, and social and general health scores than men. There were no significant differences found between gender groups for current life situation or emotional distress. After controlling for New York Heart Association classification, women still had significantly worse ratings for intermediate activities of daily living (a sub-dimension of physical functioning) and social activity., Conclusions: Despite controlling for age, EF, and New York Heart Association classification, women had worse QOL ratings than did men for intermediate activities of daily living and social activity. Research should focus on identifying why differences exist and developing measures to improve QOL, particularly physical functioning, in women with heart failure.

Novel genes specific for human oligodendroglioma and glioblastoma multiforme (GBM) were detected using the gene array analysis [18,376 genes Gene Discovery Array (GDA) from Incyte Genomics, Inc.]. Eleven genes were chosen based on the highest ratios of differential expression identified by GDA between histologically normal adjacent tissue and brain tumor tissue. The differential expression of those 11 genes was verified by semiquantitative RT-PCR and Northern analysis on 22 samples of glial and other tumors of the brain, as well as of normal embryonic and adult brain tissue. Gene no. 5 (an EST) was more expressed by GDA analysis in histologically normal adjacent brain tissue than in the corresponding oligodendroglioma. By RT-PCR, this gene was expressed in a number of brain tumors but not in normal adult and embryonic brain. By GDA analysis, gene no. 7 (oligophrenin-1) gave the highest ratio compared to other genes in brain tissue adjacent to the GBM vs. GBM. By RT-PCR, oligophrenin-1 was expressed in tumors and tumor-adjacent tissue, whereas meningioma and corpus callosum were negative. Gene no. 11 (an EST) was expressed only in brain tumors but not in normal brain by Northern analysis (message size 1.5 kb) and RT-PCR. GDA analysis successfully identified genes preferentially expressed in brain tumors, which was confirmed by Northern analysis and semiquantitative RT-PCR. The validity of gene arrays for tumor-specific gene discovery is discussed. Study of differential gene expression in glial tumors should help identify the mechanism/s of transformation of normal glial cells to malignant.

In this Phase I trial, patients' peripheral blood dendritic cells were pulsed with peptides eluted from the surface of autologous glioma cells. Three biweekly intradermal vaccinations of peptide-pulsed dendritic cells were administered to seven patients with glioblastoma multiforme and two patients with anaplastic astrocytoma. Dendritic cell vaccination elicited systemic cytotoxicity in four of seven tested patients. Robust intratumoral cytotoxic and memory T-cell infiltration was detected in two of four patients who underwent reoperation after vaccination. This Phase I study demonstrated the feasibility, safety, and bioactivity of an autologous peptide-pulsed dendritic cell vaccine for patients with malignant glioma.

Rationale: Although clinical guidelines have become increasingly popular as a means to reduce variation in care, increase efficiency, and improve patient outcomes, little is known about their effectiveness when they are transported outside their original setting, or about the factors that influence their successful translation into clinical practice. This study assessed whether a clinical guideline for low-risk chest pain patients, implemented with a standardized protocol, could be effectively transported to five hospital settings., Methods: In a prospective, interventional trial, a standardized protocol for low-risk chest pain was implemented at each site. A total of 553 consecutively hospitalized low-risk patients with chest pain were enrolled during a 3-month baseline period followed by a standardized 6-month intervention period. During the intervention period, each patient's physician was contacted about eligibility for discharge within the specified 2-day guideline period. Guideline adherence (discharged within 48 hours) and postdischarge patient outcomes were measured. Local guideline champions were interviewed about their implementation experience., Results: Guideline adherence during the intervention period ranged from 61% to 100%, with only two sites achieving significant increases of > or = 10% from the baseline values. Guideline implementation did not affect clinical outcomes or patient satisfaction. Implementation factors such as preexisting hospital environment, implementation team staffing, and the rapid identification and resolution of barriers may influence the successful translation of guidelines into practice., Conclusions: Even with a standardized implementation protocol, consistent results across institutions were not obtained when a clinical guideline for chest pain was implemented beyond its original setting. These findings demonstrate the importance of understanding the local factors that influence guideline implementation.

Background: Two and one half million women have heart failure (HF). Yet little is known about quality of life (QOL) in this population and the factors influencing it. Given the importance of QOL as an outcome of care, we conducted a study to evaluate predictors of QOL in women with HF., Methods: Using baseline QOL data collected in the Studies of Left Ventricular Dysfunction (SOLVD) trials, we studied predictors of QOL in 691 women with HF. Univariate, bivariate, and multiple regression analyses were used. Potential predictors included age, education, tobacco use, social isolation, life stresses, comorbidity index, New York Heart Association (NYHA) class, HF symptoms, etiology, and medications. We measured global QOL and QOL dimensions of physical function, emotional distress, and social and general health., Results: Women were older (61+/-10.5 years), predominantly Caucasian (75%), and their mean ejection fraction was 0.27 (+/-6.51). Variables with the strongest relationship to QOL included dyspnea, NYHA class, and life stresses. As dyspnea, life stresses, and NYHA class increased, QOL decreased. Additionally, smoking behavior and vasodilator use was associated with decreased QOL. Heart failure etiology of ischemic origin was associated with decreased social life satisfaction, and use of digitalis was predictive of increased social life satisfaction. Finally, increasing age was related to an increase in general life satisfaction., Conclusion: Symptom amelioration, which may improve functional ability, has the greatest potential for increasing QOL in women with HF. Programs to increase physical activity in women with HF should be developed and tested. Finally, clinicians may need to optimize HF medications in women.

We report here that CD40- but not lipopolysaccharide (LPS)-activated murine dendritic cells (DC) express OX40-ligand (OX40L) as has been reported in humans. To understand how OX40 ligation affects differentiation of CD4 T cells at the time of priming, we constitutively expressed OX40L on DC using the DC-specific promoter of CD11c. Transgenic mice showed greatly increased numbers of CD4 but not CD8 T cells in their B cell areas. This effect was to a great extent immunization dependent, as spleen and lymphoid tissue with no germinal center reactions from mice which had not been deliberately immunized did not show marked CD4 T cell accumulation. The increased numbers of CD4+ CD62low cells in transgenic mice suggest that it is activated CD4 T cells that accumulate within B cell follicles. These data are consistent with the notion that physiological engagement of OX40 (CD134) on activated CD4 T cells either initiates their migration into or causes them to be retained in B follicles. In contrast, LPS-treated CD did not up-regulate OX40L expression. This dichotomy provides a molecular explanation of how DC might integrate environmental and accessory signals to control cytokine differentiation and migration in CD4 effector cells.

Objective: To study the effect of a length of stay practice guideline on patient outcomes., Design: A prospective, nonrandomized, interventional trial., Setting: Six geographically distributed hospitals., Patients: Two hundred forty-two consecutively hospitalized "low-risk" patients with pneumonia., Measurements and Results: One hundred fifty-two patients (63%) completed the mailed postdischarge survey and were included in the analysis. Data were prospectively collected for 85 patients from the baseline observation period (B) and 67 patients from the intervention period (I). During the I, case managers provided physicians with patient risk information based on guideline recommendations. There was no significant change in guideline compliance (B vs I: 76.5% vs 83.6%; p=0.32) or length of stay (B vs I: 3.5 days [95% confidence interval, 3.2 to 3.8] vs 3.6 days [95% confidence interval, 3.3 to 4.0]). Also, there were no statistically significant effects of the intervention on patient outcomes, care following hospital discharge, and patient satisfaction scores., Conclusion: Patients in this study often had shorter lengths of stay than recommended by the practice guideline. This suggests that the external environment may have had a greater effect on physician behavior and length of stay than the practice guideline itself. Moreover, it demonstrates the importance of continuous assessment of physician practices immediately prior to, during, and after application of the clinical practice guideline.

Background: Although practice guidelines about appropriate lengths of stay have been widely promulgated, their effects on patient outcomes are not clear. Our objective was to study the effects of length of stay practice guidelines on patient outcomes., Patients and Methods: We performed a prospective, nonrandomized, interventional trial in six geographically distributed hospitals, among consecutively hospitalized "low-risk" patients with total hip replacement, hip fracture, or knee replacement. Case managers provided physicians with patient risk information based on guideline recommendations. We measured length of stay, compliance with recommended guideline length of stay, health status, hospital readmission rates, return to emergency department, return to work and recreation, and patient satisfaction., Results: A total of 560 patients were included in the study. For patients with knee replacement, there was a statistically significant increase in practice guideline compliance (27% baseline versus 53% intervention, P <0.0001) and reduction in length of stay (5.2 days versus 4.6 days, P <0.001) when compared with the baseline period. For hip replacement patients, there similarly was an increase in practice guideline compliance (66% baseline versus 82% intervention, P = 0.01) and reduction in length of stay (5.1 days versus 4.8 days, P = 0.03). Significant reductions in length of stay were not observed for patients recovering after hip fracture despite a significant increase in guideline compliance. There were few statistically significant changes in patient outcomes related to reductions in lengths of stay, including health status, hospital readmission rates, return to emergency department, return to work and recreation, and patient satisfaction. For patients undergoing hip replacement, very short lengths of stay (shorter than the guideline recommendation) were associated with an increased rate of discharging patients to nursing homes and rehabilitation facilities (21% versus 7%, P = 0.01), and hip fracture patients with very short lengths of stay required more visits to the doctor after discharge (56% versus 25%, P = 0.04)., Conclusion: Reductions in lengths of stay were most often associated with no significant change in patient outcomes. However, very short lengths of stay were associated with increased intensity of care following discharge for patients undergoing hip surgery, indicating possible cost shifting (the cost incurred by transferring patients to rehabilitation facilities may have been greater than had the patients remained in the acute care hospital for an additional 1 or 2 days and been sent directly home). These results emphasize the importance of monitoring the effects of cost containment and other systematic efforts to change patient care at the local level.

It is well established that lymphoid dendritic cells (DC) play an important role in the immune system. Beside their role as potent inducers of primary T cell responses, DC seem to play a crucial part as major histocompatibility complex (MHC) class II+ "interdigitating cells" in the thymus during thymocyte development. Thymic DC have been implicated in tolerance induction and also by some authors in inducing major histocompatibility complex restriction of thymocytes. Most of our knowledge about thymic DC was obtained using highly invasive and manipulatory experimental protocols such as thymus reaggregation cultures, suspension cultures, thymus grafting, and bone marrow reconstitution experiments. The DC used in those studies had to go through extensive isolation procedures or were cultured with recombinant growth factors. Since the functions of DC after these in vitro manipulations have been reported to be not identical to those of DC in vivo, we intended to establish a system that would allow us to investigate DC function avoiding artificial interferences due to handling. Here we present a transgenic mouse model in which we targeted gene expression specifically to DC. Using the CD 11c promoter we expressed MHC class II I-E molecules specifically on DC of all tissues, but not on other cell types. We report that I-E expression on thymic DC is sufficient to negatively select I-E reactive CD4+ T cells, and to a less complete extent, CD8+ T cells. In contrast, it only DC expressed I-E in a class II-deficient background, positive selection of CD4+ T cells could not be observed. Thus negative, but not positive, selection events can be induced by DC in vivo.

We show that a chimeric T cell receptor (TCR) beta chain consisting of a single-chain Fv portion derived from a monoclonal antibody and the full TCR beta chain is able to assemble functionally with endogenous TCR/CD3 components and transfer the antibody specificity as well as the TCR specificity into TCR beta- as well as into TCR beta+ T cells. This allows the incorporation new non-major histocompatibility complex-restricted ligand specificities into the intact TCR/CD3 complex which can exploit the full range of biological activities of the endogenous TCR signaling machinery. This approach can provide wider opportunities to redirect T cells to virus or tumor antigen-bearing cells.

The potential safety and effectiveness of a practice guideline recommending a 5-day postoperative stay in the acute care hospital for hip surgery patients without clinical findings predictive of a complicated hospital course was studied retrospectively in 230 patients hospitalized for total hip replacement, total hip replacement with osteotomy, or hip hemiarthroplasty. Seventy percent of total hip replacement and hip hemiarthroplasty patients were classified as being at "low risk" for complications by the guideline (161 patients, or 73% of patients who remained hospitalized). Use of the guideline could have reduced the hospital length of stay from 8.4 days (standard deviation 3.3) to 5.9 days for these selected low-risk patients. Moreover, physicians' implicit review determined that 0% of patients (95% confidence interval, 0% to 2.3%) had a complication that would have benefited from continued stay in an acute care hospital after the fifth postoperative day. Our practice guideline may have the potential to safely reduce acute care hospital length of stay for patients recovering after total hip replacement and hip hemiarthroplasty. The guideline will require further study in a prospective clinical trial before it can be recommended for widespread use.

Purpose: Few available data exist to define either the medically necessary duration of parenteral antimicrobial therapy or length of stay for hospitalized patients with pneumonia. Therefore, we investigated the potential safety and effectiveness of a practice guideline recommending early conversion of low-risk patients with pneumonia from parenteral to oral antimicrobial therapy and early hospital discharge., Patients and Methods: The practice guideline was studied retrospectively in 503 hospitalized patients with pneumonia at a teaching community hospital., Results: Thirty-three percent of patients with pneumonia were classified as at low risk for complications and potentially suitable for early conversion to oral antimicrobial therapy according to the guideline. Were the guideline to have been used to guide patient discharge decisions, 619 additional bed-days would have been made available to accommodate incoming patients. A consensus among physician reviewers led to the judgment that quality of care would not have worsened for 98.2 percent of low-risk patients had they been switched to oral antimicrobial therapy on the third hospital day, nor would quality of care have been worsened for 93.4 percent of low-risk patients had they been discharged on the fourth hospital day., Conclusion: The practice guideline that we studied has the potential to safely reduce the duration of parenteral antimicrobial therapy and length of hospital stay for selected low-risk patients with pneumonia. The guideline should be studied in a prospective clinical trial.

Our ongoing efforts in health services research have resulted in outcome-validated medical practice guidelines for common medical conditions. These practice guidelines have been shown to substantially reduce health care costs while maintaining quality of care. We have developed a computerized expert system from our practice guidelines which enhances the ease in which they can be implemented by Utilization Management (UM) Coordinators, physicians, nurses and other health care providers.

Although there is currently much enthusiasm for practice guidelines, far more energy and resources have been expended on their development than on their implementation. A prospective interventional trial was performed using a previously validated explicit practice guideline (decision aid) to decrease the hospital length of stay for selected "low-risk" patients with chest pain. Utilization management (UM) coordinators (RNs) and physicians were chosen to implement the guideline since these resource people are available in most hospitals, allowing for generalization of the experience. With explicit review criteria used for 624 patients, it was found that when the guideline was applied by UM coordinators, it had a sensitivity of 0.85, a specificity of 0.90, a positive predictive value of 0.76, and a negative predictive value of 0.94. The attending physicians failed to override falsely classified low-risk patient recommendations 51% of the time. Implicit review judged that outcome might have theoretically been worsened in two of these patients. Follow-up at 30 days after admission, however, revealed no untoward sequelae in falsely categorized patients discharged according to the guideline. Utilization management appears to be a promising mechanism for guideline implementation that is available in most institutions. However, the accuracy with which UM coordinators implement guidelines should be assessed rigorously. Guidelines should be implemented in an environment of checks and balances in which physicians have the ultimate responsibility for their patients' care.

Objectives: Recent concern about escalating healthcare expenditures has prompted healthcare payers and hospitals to identify physicians whose hospital resource consumption exceeds expected norms. The goals of this study were to determine whether analyses of practice patterns in this manner may a) systematically identify older physicians as big resource "spenders," and b) provide misleading information caused by the failure to adjust utilization data for severity of illness., Design: A prospective, observational study., Setting: The coronary care and intermediate care unit in an 1,100-bed community hospital., Patients: A total of 217 patients hospitalized for chest pain cared for by noncardiologists., Interventions: None., Measurements and Main Results: On initial inspection, it appeared that the patients of older physicians had longer lengths of stay and greater charge expenditures than the patients of younger physicians. However, further evaluation demonstrated that older physicians cared for older (76 vs. 67 yrs old, p = .0001) and more severely ill patients (judged by risk of complications, risk of acute ischemic heart disease, and disease staging). Older physicians cared for more severely ill myocardial infarction patients than did younger physicians (Killip Classification 2.0 vs. 1.1, p less than .00003). After adjusting for severity of illness, there were fewer differences in hospital charges and consultant use between older and younger physicians, although the patients of older physicians remained hospitalized longer., Conclusions: There is little difference in resource utilization between patients cared for by older and younger internists after controlling for severity of illness. This investigation highlights the potential hazards of ignoring severity of illness when judging physician efficiency in the coronary care unit.

Left ventricular dysfunction has been implicated in the pathogenesis of septic shock, but little is known about its natural history, cause, and prognostic significance. Left ventricular performance was assessed by serial radionuclide and hemodynamic studies in 35 patients with culture-proven septic shock. The mean age (+/- S.D.) of the group was 64 +/- 18 years; 16 of the subjects were women, and 15 had antecedent heart disease. On the first study, the left ventricular stroke work index was depressed in 33 (94%) patients, and nineteen (54%) had a left ventricular ejection fraction less than 0.48. Twenty-two (63%) of the patients had segmental and four had generalized wall motion abnormalities. Conventional hemodynamic parameters were of no value in predicting the patients who had a depressed left ventricular ejection fraction or segmental abnormalities. Patients with underlying heart disease had a much higher frequency (87%) of segmental dysfunction than those without underlying heart disease (45%; p = 0.016), but no differences were noted in the left ventricular ejection fraction or left ventricular stroke work index of these two groups. Segmental abnormalities and low ejection fractions were seen more often in patients with a large left ventricular end-diastolic volume index. Only five subjects had a systemic vascular resistance index greater than 2580 dynes X sec X cm-5 per m2, and the correlation between systemic vascular resistance index and left ventricular ejection fraction was poor. No difference was found in the mean coronary perfusion pressure of those with segmental abnormalities and those with normal wall motion.(ABSTRACT TRUNCATED AT 250 WORDS)

Various techniques for reading pulmonary artery and pulmonary capillary wedge pressures have been described. We feel that the most easily obtained and accurate method for reading pressures with respiratory variations should be with reference to end expiration. This is a relatively constant period of intrathoracic pressure and allows for a stable pressure waveform, which can be measured easily. No matter which technique is utilized, a standard procedure should be adopted by those reading the pressures and understood by those who must interpret them. Consistency in the method of pressure waveform reading is important to ensure meaningful measurements and subsequent appropriate treatment of the patient.

Twenty-five patients with septic shock underwent simultaneous radionuclide ventriculography and right heart catheterization to clarify the role of the right ventricle in this syndrome. A depressed right ventricular ejection fraction (less than 38%) was present in 13 patients and was found in patients with elevated cardiac output (4 of 6 patients) and with normal or low cardiac output (9 of 19 patients). Right ventricular dysfunction was seen with or without acute respiratory failure. In eight patients, a depressed right ventricular ejection fraction was seen in combination with an abnormal left ventricular ejection fraction (less than 48%), but in five patients, right ventricular ejection fraction impairment occurred with normal left ventricular ejection fraction. There was no significant correlation between abnormal right ventricular afterload and depressed right ventricular ejection fraction. No clinical or hemodynamic finding could be used to identify patients with diminished right ventricular ejection fraction. On follow-up study in 17 surviving patients, right ventricular ejection fraction improved in 6 and was unchanged in 11. Improvement in right ventricular ejection fraction occurred more frequently in patients without pulmonary hypertension or respiratory distress. The results suggest that right ventricular dysfunction in septic shock may be more common than previously suspected. It may be caused by abnormalities in right ventricular afterload in some patients and depressed myocardial contractility in others. The findings are of therapeutic importance since interventions that diminish right ventricular afterload and increase right ventricular contractility would be appropriate in patients with septic shock and right ventricular dysfunction.

The Immunization Practices Advisory Committee (ACIP) recommends that health care providers who contact high-risk patients receive influenza immunization annually. There are few available data on hospital employees' acceptance of these recommendations or their attitudes about influenza immunization. In a hospital where no formal influenza immunization program was in place, a survey of 193 nursing personnel and physicians showed that only 2.1% received the 1986-1987 trivalent influenza vaccine and 3.2% the monovalent A/Taiwan/1/86 vaccine before the 1986-1987 influenza season. An influenza-like illness developed in a total of 35.3% of hospital employees during the influenza season, and 76.6% of them cared for patients while ill. Fear of adverse reactions, avoidance of medications, and the inconvenience of vaccine administration were frequently cited reasons for declining immunization. Hospital employees would be more inclined to receive future influenza immunization if vaccine administration were more accessible and if they were informed that immunization were a national health care policy. During the influenza season, nurses and physicians should be considered a uniformly susceptible reservoir of infection capable of transmitting influenza to patients. Moreover, ACIP guidelines alone probably will not lead to acceptable immunization rates among health care providers; organized institutional efforts to promote immunization of health care providers may be required.

The total body water can be assayed by the measurement of the diffusion space of heavy water. A well reproducible and inexpensive method is the infrared spectrometry, using two differential comparisons.

Hypertensive emergencies are a diverse group of disorders characterized by a marked elevation of systemic arterial pressure that is associated with acute end-organ dysfunction. The efficacy and safety of sublingual nifedipine were evaluated in 16 men and 14 women (mean age 65 +/- 14 years) who had hypertensive emergencies. Before treatment, mean systolic blood pressure was 224 +/- 23 mm Hg, mean diastolic blood pressure was 125 +/- 18 mm Hg, and the average mean arterial pressure was 158 +/- 16 mm Hg. Administration of 10 or 20 mg of sublingual nifedipine initiated a smooth and predictable decline in blood pressure values within five minutes and produced a peak effect between 30 and 60 minutes. At 30 minutes, the decreases in the systolic blood pressure, diastolic blood pressure, and mean arterial pressure for the group were 49 +/- 24 mm Hg, 31 +/- 17 mm Hg, and 39 +/- 20 mm Hg, respectively, all of which were highly significant (p less than 0.001). By 60 minutes, nifedipine had decreased the diastolic blood pressure to less than 120 mm Hg in 97 percent of patients, less than 110 mm Hg in 93 percent, and less than 100 mm Hg in 67 percent. Fourteen patients required other antihypertensive medications within the first 12 hours for the antihypertensive effect to be maintained. In this group, the systolic, diastolic, and mean arterial pressures were significantly lower than baseline values (p less than 0.001) at the time that the other drugs were started (which occurred at a mean of 4.3 +/- 3.2 hours after entry into the study). The response to nifedipine correlated with the blood pressure value prior to treatment, but did not correlate with age, gender, value prior to treatment, but did not correlate with age, gender, or the type of hypertensive emergency. Twenty mg of nifedipine produced a significantly greater antihypertensive effect than did 10 mg during the first 20 minutes (176 +/- 15 mm Hg versus 201 +/- 18 mm Hg systolic; p = 0.009) and appeared to be more efficacious clinically. In only two of 30 patients (7 percent) was the blood pressure response considered inadequate, and all 10 patients with pulmonary edema or myocardial ischemia showed clinical improvement within 60 minutes of treatment. In one patient, flushing and another symptom suggestive of transient symptomatic hypotension developed after treatment with nifedipine. These results suggest that sublingual nifedipine is a safe, effective, and practical agent for treating patients with hypertensive emergencies.

Purpose: During an observational study, we investigated the potential benefits and risks of the use of admission and early transfer triage rules in 498 patients hospitalized with chest pain., Patients and Methods: Appropriateness of triage decisions was measured using explicit and implicit judgments., Results: Application of an admission triage rule (partially based on the Brush electrocardiographic criteria) would have increased coronary care unit (CCU) admissions by 3%, whereas application of a triage rule 24 hours after admission would have reduced bed utilization by 860 intermediate care and 82 CCU bed-days per year when compared with actual patient triage. Although 9.5% of patients who underwent triage according to the early transfer triage rule would have experienced a minor complication after transfer, the medical care of none would have been adversely affected., Conclusion: Our results show that application of a triage rule 24 hours after admission may have the potential to shorten length of stay in the CCU and intermediate care unit without significantly compromising patient care. However, use of the admission triage rule would have increased CCU bed utilization. The failure of the admission triage rule to improve bed utilization illustrates the potential hazards of ignoring patient complications, interventions, and co-morbidity when predicting the efficacy of a triage rule.

Neutropenia is a rare complication of procainamide therapy. However, over a period of 20 months, 8 patients developed severe neutropenia while taking a sustained-release preparation of the drug. Seven patients presented with fever and constitutional symptoms and one patient was asymptomatic. Bone marrow examinations showed myeloid aplasia or maturation arrest in 5 patients and myeloid hyperplasia in 1. Neutropenia resolved within 30 days of drug withdrawal, and all patients survived. A case-control study showed a significant association between sustained-release procainamide therapy and severe neutropenia in 5 of 114 patients (4.4%) recovering from open-heart surgery (Mantel-Haenszel chi square = 13.84; p less than 0.001). Thus, life-threatening neutropenia may be common with sustained-release procainamide preparations.

The cost-effectiveness of nifedipine for the control of acute hypertension is analyzed. The study compares routine hospital utilization of a set of patients who were administered nifedipine (the experimental group) with a set of patients who were given nitroprusside (the control group). The experimental group consists of a set of 32 patients who presented to the emergency department with acute hypertension and were treated with nifedipine. The control group is a set of 14 patients who presented with acute hypertension to the emergency departments of two other hospitals. Both experimental and control groups were seen and treated in 1983 and 1984. The patients in the control group were matched/paired with the experimental group patients. Hospital utilization was measured at four times: one, two, three, and four days after admission. For each time, utilization is classified as intensive, intermediate, or routine. In addition, intensive care is further classified according to nursing/patient ratios. Differences in both utilization levels and total costs are compared for the matched control and experimental groups.

Cachexia is a common manifestation of advanced cancer and frequently contributes to physical disability and mortality. An increased metabolic rate has been suggested to be one of the causes of cancer-induced cachexia, although the mechanisms producing this hypermetabolism remain unclear. The presence and activation of brown adipose tissue, a highly thermogenic tissue, may result in a hypermetabolic state and be partially responsible for weight loss in cancer patients. To investigate this hypothesis, we examined necropsy samples of peri-adrenal tissues using light microscopy to identify the prevalence of brown adipose tissue in 25 cachectic patients who died from cancer and 15 age-matched subjects who died from other illnesses. Brown adipose tissue was observed in 20 of the cancer patients (80%) compared to 2 of the age-matched subjects (13%). Therefore, our preliminary results indicate that a high prevalence of brown adipose tissue is associated with cancer-induced cachexia and may reflect an abnormal mechanism responsible for profound energy expenditure and weight loss.