Abstract 4342: Predictive precision medicine platform accurately predicts individual patient response to AML treatments to maximize outcomes

Introduction: Offering the optimal frontline treatment to a patient with acute myeloid leukemia (AML) requires trading off expected benefit and risk. Typical standard of care intensive induction chemotherapy (e.g., cytarabine plus idarubicin (7+3)) results in high clinical response rates. However, many patients receive a less intensive regimen (e.g., venetoclax plus decitabine (VenDec)) because their individual toxicity risk is high based on lack of medical fitness. Predicting an individual patient’s clinical response prior to treatment has the potential to increase the benefit/risk ratio (therapeutic index) for some patients and optimize their treatment selection. Here, we demonstrate the ability of an automated high-throughput, multi-color flow cytometry predictive precision medicine platform (PPMP) to predict response to 7+3 or VenDec.

Methods: To assess correlation between PPMP-predicted and actual clinical response to 7+3 or VenDec in clinical trial NCT04263181, pre-induction blood samples were collected from 31 patients of which 18 received 7+3 (all newly diagnosed (ND) AML) and 13 VenDec (7 ND AML, 5 secondary AML, 1 MDS). We measured drug effects on leukemic blasts by applying a cutoff at the total blast count that optimizes separation between predicted responders and non-responders (“conventional approach”) or by a machine learning (ML) approach considering multiple cell populations. For the former approach, training sets represented 13 patients for 7+3 and 8 for VenDec. Both 7+3 and VenDec models were validated with 5 patients. For the ML approach, the model was trained on all 13 VenDec patients and monitored using leave-one-out cross-validation.

Results: For the conventional approach, predicted and true clinical responses were highly correlated for 7+3 (AUC = 0.91) and VenDec (AUC = 0.81), with 100% precision (positive predictive values (PPV)) for both, i.e., all predicted responders were true clinical responders. Some true clinical responders were not identified (negative predictive value (NPV) = 67% for 7+3 and 57% for VenDec), resulting in an accuracy of 94% (7+3) and 77% (VenDec). To maximize NPV and accuracy for predicting VenDec clinical outcomes, we applied a novel ML-based algorithm to integrate the behavior of malignant and non-malignant cell populations, yielding a model with 100% accuracy (100% PPV and NPV). Additional outcome data, including overall survival, are under evaluation.

Summary: Total blast-based predictions yielded accuracies of 94% for 7+3 and 77% for VenDec. An ML algorithm for VenDec considering additional cell populations increased the accuracy to 100%. Further studies will expand patient numbers. We plan to use this platform to inform our frontline decision making with the goal to maximize the therapeutic benefit/risk ratio and ensure that the most appropriate frontline therapy is used for each individual patient.

Citation Format: Meagan A. Jacoby, John S. Welch, Peter Westervelt, Matthew Christopher, Geoffrey L. Uy, Ravi Vij, Keith E. Stockerl-Goldstein, Brad S. Kahl, Iskra Pusic, John F. DiPersio, Mark A. Schroeder, Miriam Y. Kim, Todd A. Fehniger, Armin Ghobadi, Christine J. Gu, Wade Anderson, Kathryn Vanderlaag, Kamran Ali, Camille Pataki, Markus D. Lacher. Predictive precision medicine platform accurately predicts individual patient response to AML treatments to maximize outcomes. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4342.

Discovery of : an Efficient Inhibitor of the HDM2-p53 Protein-Protein Interaction

Identification of low-dose, low-molecular-weight, drug-like inhibitors of protein-protein interactions (PPIs) is a challenging area of research. Despite the challenges, the therapeutic potential of PPI inhibition has driven significant efforts toward this goal. Adding to recent success in this area, we describe herein our efforts to optimize a novel purine carboxylic acid-derived inhibitor of the HDM2-p53 PPI into a series of low-projected dose inhibitors with overall favorable pharmacokinetic and physical properties. Ultimately, a strategy focused on leveraging known binding hot spots coupled with biostructural information to guide the design of conformationally constrained analogs and a focus on efficiency metrics led to the discovery of MK-4688 (compound 56), a highly potent, selective, and low-molecular-weight inhibitor suitable for clinical investigation.

Projected Dose Optimization of Amino- and Hydroxypyrrolidine Purine PI3Kδ Immunomodulators

The approvals of idelalisib and duvelisib have validated PI3Kδ inhibitors for the treatment for hematological malignancies driven by the PI3K/AKT pathway. Our program led to the identification of structurally distinct heterocycloalkyl purine inhibitors with excellent isoform and kinome selectivity; however, they had high projected human doses. Improved ligand contacts gave potency enhancements, while replacement of metabolic liabilities led to extended half-lives in preclinical species, affording PI3Kδ inhibitors with low once-daily predicted human doses. Treatment of C57BL/6-Foxp3-GDL reporter mice with 30 and 100 mg/kg/day of 3c (MSD-496486311) led to a 70% reduction in Foxp3-expressing regulatory T cells as observed through bioluminescence imaging with luciferin, consistent with the role of PI3K/AKT signaling in Treg cell proliferation. As a model for allergic rhinitis and asthma, treatment of ovalbumin-challenged Brown Norway rats with 0.3 to 30 mg/kg/day of 3c gave a dose-dependent reduction in pulmonary bronchoalveolar lavage inflammation eosinophil cell count.

Optimization of Versatile Oxindoles as Selective PI3Kδ Inhibitors

The 3,3-disubstituted oxindole moiety is a versatile and rigid three-dimensionally shaped scaffold. When engineered with a purine hinge-binding core, exceptionally selective PI3Kδ kinase inhibitors were discovered by exploiting small differences in isoform selectivity pockets. Crystal structures of early lead 2f bound to PI3Kδ and PI3Kα helped rationalize the high selectivity observed with 2f. By attenuating the lypophilicity and metabolic liabilities of an oxindole moiety, we improved the preclinical species PK and solubility and reduced adenosine uptake activity. The excellent potency and kinome selectivity of 7-azaoxindole 4d and spirooxindole 5d, together with a low plasma clearance and good half-life in rat and dog, supported a low once-daily predicted human dose.

Extranodal lymphoma of the tongue, a very rare entity-report of two cases with literature review

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The extranodal lymphoma of the base of the tongue is extremely rare.

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Among the lymphoma of the tongue; B cell lymphoma is more common than T cell lymphoma.

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It should be included in the differentials in patients with tumors arising from this site.

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Early detection and treatment can often result in a complete cure and a better long-term survival.

Background

Lymphomas are malignant neoplasms of the lymphocyte cell lines affecting the lymph nodes, spleen and other nonhemopoietic tissues. Of the extranodal lymphomas found in the head and neck region, 3–5% of malignant lymphomas arise in the oral and paraoral region, mainly from Waldeyer's ring. The involvement of the base of the tongue is extremely rare.

Summarised Case

Case 1: 64 year old female who presented initially with an enlarged occipital lymph node which gradually became generalized cervical lymphadenopathy with initial histology confirmed reactive lymphoid hyperplasia. Biopsy of left postero-lateral tongue lesion eventually showed high grade T cell lymphoma.

Case 2: 85 year old male presented with history of dysphagia for one year who was found to have a lesion extending from his base of tongue into the nasopharynx. Histology showed a diffuse B cell lymphoma.

Discussion

Both patients were noted to have lesion of the tongue, but tongue lesions are noted in the literature to be extremely rare. When tongue lymphomas do occur, most are of B-cell origin; the diffuse large-cell variety is the most common. Extranodal lymphomas of the T cell phenotype tend more to be sinonasal in origin than of the tongue, with T cell lymphomas of the tongue being even rarer than B cell lymphomas.

Conclusion

With regards to tumours arising in the tongue, squamous cell carcinomas are still classified as the most common. Lymphomas however, should still be kept in consideration as a differential diagnosis with regards to lesions arising from this site.

Abstract PR03: Genomic approaches for risk assessment in acute myeloid leukemia

Acute myeloid leukemia is heterogeneous with respect to clinical outcome and molecular pathogenesis. Approximately 20% of AML cases are refractory to induction chemotherapy, and about 50% of patients ultimately relapse within a time interval that ranges from months to years. At the molecular level, diverse chromosomal abnormalities and genetic mutations have been observed across patients1. Although several clinical factors (age, white blood cell count), cytogenetic aberrations (t[15;17] translocation, loss of chromosome 5) 2-4, and genetic mutations (DNMT3A, FLT3) have been associated with differences in survival 5,6, these factors are of limited prognostic utility. Moreover, few studies have integrated sequence data with clinical and cytogentic factors to build predictive models of patient outcome.

Here, we sought to identify genomic predictors of refractory disease or early relapse. We used whole genome and exome sequencing to analyze the genomes of 71 adult de novo AML patients treated with anthracycline and cytarabine-based induction chemotherapy. Of these, 34 had refractory disease or relapsed within 6 months, 12 relapsed in 6-12 months, and 25 had a long first remission (>12 months). We also developed an enhanced exome sequencing (EES) approach to identify and follow leukemia-associated variants over time. In 12 additional patients that achieved morphologic remission after induction chemotherapy, we used EES to identify and track variants at time of diagnosis, time of morphologic remission (roughly 30 days later), and a final time point corresponding to eventual relapse (n=8) or extended remission (n=4).

No novel coding or non-coding variants present at the time of diagnosis were found to be predictive of refractory disease or early relapse. Using EES, however, we were able to detect leukemia-associated variants in the initial remission bone marrow in all eight patients who eventually relapsed. One persistent leukemia-associated variant was also detected in one patient still in remission, but all other variants in that patient were eliminated. We also detected 64 somatic variants that became enriched following chemotherapy, but were not detected in the original leukemic cells. These may represent relapse-specific variants or oligoclonal hematopoiesis after bone marrow recovery. Overall, our data suggest that the persistence of leukemia-associated variants after bone marrow recovery from cytotoxic therapy is strongly correlated with relapse, and may be used to complement more traditional, morphologic measures of leukemic cell clearance.

1. Cancer Genome Atlas Research N. Genomic and epigenomic landscapes of adult de novo acute myeloid leukemia. The New England Journal of Medicine 2013;368:2059-74.

2. Byrd JC, Mrozek K, Dodge RK, et al. Pretreatment cytogenetic abnormalities are predictive of induction success, cumulative incidence of relapse, and overall survival in adult patients with de novo acute myeloid leukemia: results from Cancer and Leukemia Group B (CALGB 8461). Blood 2002;100:4325-36.

3. Grimwade D, Hills RK, Moorman AV, et al. Refinement of cytogenetic classification in acute myeloid leukemia: determination of prognostic significance of rare recurring chromosomal abnormalities among 5876 younger adult patients treated in the United Kingdom Medical Research Council trials. Blood 2010;116:354-65.

4. Schlenk RF, Dohner K, Krauter J, et al. Mutations and treatment outcome in cytogenetically normal acute myeloid leukemia. The New England Journal of Medicine 2008;358:1909-18.

5. Kihara R, Nagata Y, Kiyoi H, et al. Comprehensive analysis of genetic alterations and their prognostic impacts in adult acute myeloid leukemia patients. Leukemia 2014;28:1586-95.

6. Ley TJ, Ding L, Walter MJ, et al. DNMT3A mutations in acute myeloid leukemia. The New England Journal of Medicine 2010;363:2424-33.

This abstract is also presented as a poster at the Translation of the Cancer Genome conference.

Citation Format: Jeffery M. Klco, Christopher A. Miller, Malachi Griffith, Allegra Petti, David H. Spencer, Shamika Ketkar-Kulkarni, Lukas D. Wartman, Matthew Christopher, Tamara L. Lamprecht, Jacqueline E. Payton, Jack Baty, Sharon E. Heath, Obi L. Griffith, Dong Shen, Jasreet Hundal, Gue Su Chang, Robert S. Fulton, Michelle O'laughlin, Catrina Fronick, Vincent Magrini, Ryan Demeter, David E. Larson, Shashikant Kulkarni, Bradley A. Ozenberger, John S. Welch, Matthew J. Walker, Timothy A. Graubert, Peter Westervelt, Jerald P. Radich, Daniel C. Link, Elaine R. Mardis, John F. DiPersio, Richard K. Wilson. Genomic approaches for risk assessment in acute myeloid leukemia. [abstract]. In: Proceedings of the AACR Special Conference on Computational and Systems Biology of Cancer; Feb 8-11 2015; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2015;75(22 Suppl 2):Abstract nr PR03.

Abstract PR11: Genomic approaches for risk assessment in acute myeloid leukemia

Acute myeloid leukemia is heterogeneous with respect to clinical outcome and molecular pathogenesis. Approximately 20% of AML cases are refractory to induction chemotherapy, and about 50% of patients ultimately relapse within a time interval that ranges from months to years. At the molecular level, diverse chromosomal abnormalities and genetic mutations have been observed across patients1. Although several clinical factors (age, white blood cell count), cytogenetic aberrations (t[15;17] translocation, loss of chromosome 5) 2-4, and genetic mutations (DNMT3A, FLT3) have been associated with differences in survival 5,6, these factors are of limited prognostic utility. Moreover, few studies have integrated sequence data with clinical and cytogentic factors to build predictive models of patient outcome.

Here, we sought to identify genomic predictors of refractory disease or early relapse. We used whole genome and exome sequencing to analyze the genomes of 71 adult de novo AML patients treated with anthracycline and cytarabine-based induction chemotherapy. Of these, 34 had refractory disease or relapsed within 6 months, 12 relapsed in 6-12 months, and 25 had a long first remission (>12 months). We also developed an enhanced exome sequencing (EES) approach to identify and follow leukemia-associated variants over time. In 12 additional patients that achieved morphologic remission after induction chemotherapy, we used EES to identify and track variants at time of diagnosis, time of morphologic remission (roughly 30 days later), and a final time point corresponding to eventual relapse (n=8) or extended remission (n=4).

No novel coding or non-coding variants present at the time of diagnosis were found to be predictive of refractory disease or early relapse. Using EES, however, we were able to detect leukemia-associated variants in the initial remission bone marrow in all eight patients who eventually relapsed. One persistent leukemia-associated variant was also detected in one patient still in remission, but all other variants in that patient were eliminated. We also detected 64 somatic variants that became enriched following chemotherapy, but were not detected in the original leukemic cells. These may represent relapse-specific variants or oligoclonal hematopoiesis after bone marrow recovery. Overall, our data suggest that the persistence of leukemia-associated variants after bone marrow recovery from cytotoxic therapy is strongly correlated with relapse, and may be used to complement more traditional, morphologic measures of leukemic cell clearance.

1. Cancer Genome Atlas Research N. Genomic and epigenomic landscapes of adult de novo acute myeloid leukemia. The New England Journal of Medicine 2013;368:2059-74.

2. Byrd JC, Mrozek K, Dodge RK, et al. Pretreatment cytogenetic abnormalities are predictive of induction success, cumulative incidence of relapse, and overall survival in adult patients with de novo acute myeloid leukemia: results from Cancer and Leukemia Group B (CALGB 8461). Blood 2002;100:4325-36.

3. Grimwade D, Hills RK, Moorman AV, et al. Refinement of cytogenetic classification in acute myeloid leukemia: determination of prognostic significance of rare recurring chromosomal abnormalities among 5876 younger adult patients treated in the United Kingdom Medical Research Council trials. Blood 2010;116:354-65.

4. Schlenk RF, Dohner K, Krauter J, et al. Mutations and treatment outcome in cytogenetically normal acute myeloid leukemia. The New England Journal of Medicine 2008;358:1909-18.

5. Kihara R, Nagata Y, Kiyoi H, et al. Comprehensive analysis of genetic alterations and their prognostic impacts in adult acute myeloid leukemia patients. Leukemia 2014;28:1586-95.

6. Ley TJ, Ding L, Walter MJ, et al. DNMT3A mutations in acute myeloid leukemia. The New England Journal of Medicine 2010;363:2424-33.

Citation Format: Jeffery M. Klco, Christopher A. Miller, Malachi Griffith, Allegra Petti, David H. Spencer, Shamika Ketkar-Kulkarni, Lukas D. Wartman, Matthew Christopher, Tamara L. Lamprecht, Jacqueline E. Payton, Jack Baty, Sharon E. Heath, Obi L. Griffith, Dong Shen, Jasreet Hundal, Gue Su Chang, Robert S. Fulton, Michelle O'laughlin, Catrina Fronick, Vincent Magrini, Ryan Demeter, David E. Larson, Shashikant Kulkarni, Bradley A. Ozenberger, John S. Welch, Matthew J. Walker, Timothy A. Graubert, Peter Westervelt, Jerald P. Radich, Daniel C. Link, Elaine R. Mardis, John F. DiPersio, Richard K. Wilson. Genomic approaches for risk assessment in acute myeloid leukemia. [abstract]. In: Proceedings of the AACR Special Conference on Translation of the Cancer Genome; Feb 7-9, 2015; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2015;75(22 Suppl 1):Abstract nr PR11.

Association Between Mutation Clearance After Induction Therapy and Outcomes in Acute Myeloid Leukemia

IMPORTANCE

Tests that predict outcomes for patients with acute myeloid leukemia (AML) are imprecise, especially for those with intermediate risk AML.

OBJECTIVES

To determine whether genomic approaches can provide novel prognostic information for adult patients with de novo AML.

DESIGN, SETTING, AND PARTICIPANTS

Whole-genome or exome sequencing was performed on samples obtained at disease presentation from 71 patients with AML (mean age, 50.8 years) treated with standard induction chemotherapy at a single site starting in March 2002, with follow-up through January 2015. In addition, deep digital sequencing was performed on paired diagnosis and remission samples from 50 patients (including 32 with intermediate-risk AML), approximately 30 days after successful induction therapy. Twenty-five of the 50 were from the cohort of 71 patients, and 25 were new, additional cases.

EXPOSURES

Whole-genome or exome sequencing and targeted deep sequencing. Risk of identification based on genetic data.

MAIN OUTCOMES AND MEASURES

Mutation patterns (including clearance of leukemia-associated variants after chemotherapy) and their association with event-free survival and overall survival.

RESULTS

Analysis of comprehensive genomic data from the 71 patients did not improve outcome assessment over current standard-of-care metrics. In an analysis of 50 patients with both presentation and documented remission samples, 24 (48%) had persistent leukemia-associated mutations in at least 5% of bone marrow cells at remission. The 24 with persistent mutations had significantly reduced event-free and overall survival vs the 26 who cleared all mutations. Patients with intermediate cytogenetic risk profiles had similar findings. [table: see text].

CONCLUSIONS AND RELEVANCE

The detection of persistent leukemia-associated mutations in at least 5% of bone marrow cells in day 30 remission samples was associated with a significantly increased risk of relapse, and reduced overall survival. These data suggest that this genomic approach may improve risk stratification for patients with AML.

A validated cadaveric model of trochlear dysplasia

PURPOSE

Despite the high prevalence of trochlear dysplasia among patients with patellar instability, it is not well studied and is infrequently addressed surgically. The lack of a validated cadaveric model of trochlear dysplasia may be a contributing factor. The goal of this study was to develop a simple, reproducible, and realistic cadaveric model of trochlear dysplasia by surgically modifying cadaveric femora with normal anatomy and then to validate this model through the use of mechanical and fluoroscopic measurements.

METHODS

The floor of the trochlear groove was surgically elevated using an inflatable bone tamp in eight cadaveric femora. The trochlear depth (TD) was measured with a custom-designed measuring device, and radiographic markers of dysplasia (sulcus angle, crossing sign, and prominence) were assessed before and after surgical modification.

RESULTS

The average TD was 3.6±1.4, 4.6±1.1, and 5.1±1.0 mm prior to reverse trochleoplasty (RT) and 1.0±1.8, 2.3±1.3, and 3.3±2.5 mm following RT at 0°, 20°, and 40° of flexion, respectively. These direct measurements of TD were confirmed with fluoroscopy. The sulcus angle averaged 141° prior to RT and 157° after RT. The average prominence across all specimens was 3.3±0.7 mm before RT, and 5.5±1.5 mm after RT. Finally, the crossing sign was found to be absent in all knees prior to RT and present in 7 of the 8 after RT.

CONCLUSIONS

The results of this study show that elevation of the trochlear floor with an inflatable bone tamp can reproducibly create a simulated dysplastic trochlea. This model may be useful in biomechanical studies of treatments for patellofemoral instability.

Is abdominal aortic calcification score a cost-effective screening tool to predict atherosclerotic carotid plaque and cardiac valvular calcification in patients with end-stage renal disease?

Abdominal aortic calcification (AAC), cardiac valvular calcification (CVC), and atherosclerotic carotid plaque (CP) are known cardiovascular risk factors. The accuracy of the AAC score in predicting CP and CVC in patients with end-stage renal disease (ESRD) is assessed in this study. Twenty-two consecutive prevalent dialysis patients (group 1) and 26 consecutive nondialysis stage V chronic kidney disease patients (group 2) were assessed for their demographic and laboratory variables. Lateral radiograph of the lumbosacral spine was used to assess the AAC score. CP and CVC were assessed using carotid sonography and echocardiogram, respectively. Prevalence of AAC, CP, and CVC in groups 1 and 2 was, respectively, 72.7%, 81.8%, and 72.7% and 76.9%, 80.8%, and 57.7%. AAC was strongly associated with CP and CVC in both groups (P < 0.001). Tests of accuracy for the AAC score as a predictor of CP and CVC showed sensitivity, specificity, positive predictive value, negative predictive value, likelihood ratio of a positive test, and likelihood ratio of a negative test, respectively, in group 1: 83%, 75%, 93%, 50%, 3.32, and 0.23 and 85%, 77%, 87%, 70%, 4.5, and 0.29, and in group 2: 90%, 95%, 83%, 69%, 3.9, 0.41, and 82%, 91%, 77%, 71%, 4.1, and 0.21. Reproducibility of the AAC score among observers was acceptable. The AAC score can predict CP and CVC with moderate accuracy in ESRD patients. However, as our study was underpowered, the findings need validation in larger, adequately powered studies.

Use of Toll-Like Receptor 3 Agonists Against Respiratory Viral Infections

Respiratory RNA viruses are constantly evolving, thus requiring development of additional prophylactic and therapeutic strategies. Harnessing the innate immune system to non-specifically respond to viral infection has the advantage of being able to circumvent viral mutations that render the virus resistant to a particular therapeutic agent. Viruses are recognized by various cellular receptors, including Toll-like receptor (TLR) 3 which recognizes double-stranded (ds)RNA produced during the viral replication cycle. TLR3 agonists include synthetic dsRNA such as poly (IC), poly (ICLC) and poly (AU). These agents have been evaluated and found to be effective against a number of viral agents. One major limitation has been the toxicity associated with administration of these drugs. Significant time and effort have been spent to develop alternatives/modifications that will minimize these adverse effects. This review will focus on the TLR3 agonist, poly (IC)/(ICLC) with respect to its use in treatment/prevention of respiratory viral infections.

Contrasting effects of exercise, AICAR, and increased fatty acid supply on in vivo and skeletal muscle glucose metabolism

The increased energy required for acute moderate exercise by skeletal muscle (SkM) is derived equally from enhanced fatty acid (FA) oxidation and glucose oxidation. Availability of FA also influences contracting SkM metabolic responses. Whole body glucose turnover and SkM glucose metabolic responses were determined in paired dog studies during 1) a 30-min moderate exercise (maximal oxygen consumption of approximately 60%) test vs. a 60-min low-dose 5-aminoimidazole-4-carboxamide-1-beta-d-ribofuranoside (AICAR) infusion, 2) a 150-min AICAR infusion vs. modest elevation of FA induced by a 150-min combined intralipid-heparin (IL/hep) infusion, and 3) an acute exercise test performed with vs. without IL/hep. The exercise responses differed from those observed with AICAR: plasma FA and glycerol rose sharply with exercise, whereas FA fell and glycerol was unchanged with AICAR; glucose turnover and glycolytic flux doubled with exercise but rose only by 50% with AICAR; SkM glucose-6-phosphate rose and glycogen content decreased with exercise, whereas no changes occurred with AICAR. The metabolic responses to AICAR vs. IL/hep differed: glycolytic flux was stimulated by AICAR but suppressed by IL/hep, and no changes in glucose turnover occurred with IL/hep. Glucose turnover responses to exercise were similar in the IL/hep and non-IL/hep, but SkM lactate and glycogen concentrations rose with IL/hep vs. that shown with exercise alone. In conclusion, the metabolic responses to acute exercise are not mimicked by a single dose of AICAR or altered by short-term enhancement of fatty acid supply.

Effects of different aspirin formulations on platelet aggregation times and on plasma salicylate concentrations

BACKGROUND

Early aspirin treatment is widely used to inhibit platelet activity and to reduce morbidity and mortality in patients presenting with an acute myocardial infarction or a stroke. A number of different aspirin formulations have been used for this purpose; however, a comparison of their effectiveness in inhibiting early platelet aggregation has not been determined.

METHODS

In this study, we determined plasma salicylate concentrations and platelet inhibitory activities at various times after ingestion of three commonly used aspirin formulations: soluble aspirin (Alka-Seltzer), 325 mg, chewed baby aspirin, 324 mg, and whole compressed non-enteric coated aspirin, 324 mg. Twenty-four healthy volunteers, 18-39 years of age, participated in the prospective single-blinded triple-crossover study. Plasma salicylate concentrations and inhibition of arachidonic acid-induced platelet aggregation were determined on post-dose blood samples collected at 2.5, 5.0, 7.5, 10, 15, 20, 25, 30, and 40 min. All subjects crossed over to the other two formulations with at least 2 weeks between ingestions.

RESULTS

The median platelet inhibition times for the chewed, soluble, and whole aspirin formulations were 7.5, 7.5, and 10.0 min, respectively. Soluble and chewed aspirin were found to inhibit platelet aggregation faster than whole aspirin (p<0.001); however, there were no significant differences in platelet aggregation times between the soluble and chewed formulations (p<0.163). Inhibition of platelet aggregation was found to occur at an average plasma salicylate concentration of 2.46 microg/mL, regardless of method of ingestion.

CONCLUSION

The results indicate that soluble and chewed aspirin inhibit platelet aggregation in a shorter period of time than does whole aspirin. The results suggest that chewing baby aspirin or taking soluble buffered aspirin may be the preferred route of administration for early platelet inhibition.

Leptospirosis--an overview

One of the important causes of acute febrile illness in a country where malaria, typhoid and dengue are also not uncommon, leptospirosis, a zoonotic disease spread by rodents, is endemic in Tamil Nadu, Kerala and Andamans; and is now being increasingly reported from other parts of India, perhaps with better facility to diagnose the disease. Disease of profound importance in view of its grave outcome, in its icteric form (Weil's disease), may have a mortality of as high as 40%. Worst prognosticator is the presence of multi-organ failure (MOF), as in any other septicemia. Andaman hemorrhagic fever (AHF), a type peculiar to Andamans, is now being described elsewhere in the country also. IgM ELISA, Dot-ELISA, dip-stick method and slide agglutination test (SAT) are newer screening methods for diagnosis of leptospirosis, but are only genus-specific. Identifying specific serovar is possible by Micro-agglutination test (MAT) and culture method only. Anicteric type of disease, however, is easily treatable with penicillin and has a good prognosis. Oral doxycycline can be used for prophylaxis during the risk of exposure.

An evolutionary approach to the architecture of effective healthcare delivery systems

PURPOSE

Aims to show that material flow concepts developed and successfully applied to commercial products and services can form equally well the architectural infrastructure of effective healthcare delivery systems.

DESIGN/METHODOLOGY/APPROACH

The methodology is based on the "power of analogy" which demonstrates that healthcare pipelines may be classified via the Time-Space Matrix.

FINDINGS

A small number (circa 4) of substantially different healthcare delivery pipelines will cover the vast majority of patient needs and simultaneously create adequate added value from their perspective.

RESEARCH LIMITATIONS/IMPLICATIONS

The emphasis is firmly placed on total process mapping and analysis via established identification techniques. Healthcare delivery pipelines must be properly engineered and matched to life cycle phase if the service is to be effective.

PRACTICAL IMPLICATIONS

This small family of healthcare delivery pipelines needs to be designed via adherence to very specific-to-purpose principles. These vary from "lean production" through to "agile delivery".

ORIGINALITY/VALUE

The proposition for a strategic approach to healthcare delivery pipeline design is novel and positions much currently isolated research into a comprehensive organisational framework. It therefore provides a synthesis of the needs of global healthcare.

Learning from different cultures--a cultural diversity project in end-of-life care

In January 1997, Midwest Bioethics Center (MBC) launched PATHWAYS to Improve End-of-Life Care, a three-year multifaceted community initiative to improve care of the dying in the Kansas City metropolitan area. Pathways focused on professional education and development, institutional reform, and public engagement, using thirteen different strategies to accomplish dozens of projects. Ultimately, more than 2,000 professionals and other community leaders were involved and more than 600 organizations participated. This article describes a cultural diversity project on end-of-life care that developed from this program.

Methylation and mutational analysis of p27(kip1) in prostate carcinoma

BACKGROUND

We have previously identified 12p12-13 as a region of frequent genetic loss in prostate carcinoma. A candidate tumor suppressor gene at this locus is the cyclin dependent kinase inhibitor p27(kip1), which has been implicated as a marker of aggressive prostate carcinoma. Herein, we examine metastatic prostate tumors, xenografts, and cell lines for gene inactivation via mutational inactivation or promoter hypermethylation.

METHODS

Mutation analysis was performed on metastatic prostate tumors of 18 patients, eight prostate carcinoma cell lines, and 18 xenografts by PCR amplification of the entire open reading frame of p27(kip1). PCR products were sequenced directly using internal primers. Methylation analysis was performed on four cell lines and nine xenografts using direct sequencing of cloned PCR products of bisulfite treated DNA. Presence of a CpG was consistent with methylation of that cytosine in the original sample.

RESULTS

With the exception of the previously reported homozygous deletion, no additional mutations were identified. Methylated CpG residues were identified in three xenografts (LuCAP23, LuCAP35, and PC82) and the methylated residues clustered at six sites; the cytosines 69, 149, 191, 286, 349, and 487 base pairs 5' of the ATG start codon. However, no sample demonstrated promotor methylation in all sequenced clones and the number of methylated base pairs ranged from seven to three, not the level usually associated with gene silencing.

CONCLUSIONS

Mutational inactivation of p27(kip1) is a rare event in metastatic prostate carcinoma. While CpG methylation does occur, it is an infrequent event and does not appear to be the mechanism of p27(kip1) down regulation in prostate carcinoma.

Role of Ethics Committees, Ethics Networks, and Ethics Centers in Improving End-of-Life Care

This article chronicles the work of Midwest Bioethics Center, several community-state partnerships, and other local and national initiatives to determine their proper role and appropriate contribution. Professional education and development, institutional reform, and community engagement are areas of concern because ethics committees, networks, and centers sponsor workshops and conferences on palliative care for healthcare professionals, hold public forums, develop advance care planning projects, and provide expertise to legislators and other policymakers. The leading edge of the work being done by ethics committees, networks, and centers appears to be using continuous quality improvement methods, specifically the development of quality indicators, to promote accountability in end-of-life care reform efforts. This work is something that ethics committees can and should take on.

Insulin secretion in growth hormone-deficient adults: effects of 24 months' therapy and five days' acute withdrawal of recombinant human growth hormone

Beta-cell function in growth hormone (GH)-deficient (GHD) adults is poorly documented. Beta-cell function was therefore studied in 10 GHD adults (age, 40+/-3 years; weight, 79.3+/-4.8 kg; body mass index [BMI], 27.5+/-1.3 kg x m(-2)) before and after 6- and 24-month recombinant human GH (rhGH) therapy (0.24 IU x kg(-1) x wk(-1)) compared with 10 age-, sex-, weight-, and BMI-matched control subjects. With rhGH therapy, fat-free mass (FFM) increased (48.2+/-4.9, 52.5+/-4.8, and 59+/-6.8 kg, respectively) and fat mass (FM) decreased (33.8%+/-2.8%, 28.0%+/-3.0%, and 29.4%+/-2.5%, respectively), as did serum cholesterol. Oral glucose tolerance initially deteriorated at 6 months, but improved toward the control value by 24 months. Fasting insulin (FI) increased significantly, as did the acute insulin response to oral glucose (deltaAIR(OGTT)/deltaG) at 30 minutes (FI: pretreatment 9.8+/-0.8, 6 months, 14.0+/-1.8, 24 months 12.5+/-1.6 v control 11.4+/-1.9 mU x L(-1); deltaAIR(OGTT)/deltaG: pretreatment 201+/-24, 6 months 356+/-41, 24 months 382+/-86 v control 280+/-47 mU x mmol(-1)). However, the acute insulin response to intravenous (IV) glucose (AIR(G)) and IV glucagon at euglycemia and hyperglycemia did not change with rhGH therapy and were similar to the control group values. Importantly, the expected reciprocal relationships (as observed for the control group) between the various insulin secretory parameters and insulin sensitivity (SI) either were not present or were statistically weak in GHD subjects, despite the 35% decrease in SI by 24 months of rhGH therapy. In particular, over time, there was an attenuation of insulin secretion with respect to the ongoing insulin resistance with rhGH therapy, particularly for AIR(G) at 24 months. After 5 days of rhGH withdrawal, insulin secretion decreased and SI improved in GHD subjects. It is concluded that the current long-term rhGH treatment regimens appear to impact on insulin secretion such that the normal relationships between insulin secretion and SI are altered despite the favorable impact on body composition and serum lipid profiles.

My mother's gift--the link between honesty and hope

Doctors and other care providers often refuse to be direct and straightforward with patients needing end-of-life care because they do not want to take away hope. But the resiliency of hope is not linked with continuing life. Using introspection, a review of the literature, and a sampling of opinions gleaned from members and friends of the Midwest Bioethics Center, the author of this article concludes that all patients should be given full and forthright knowledge about the prognoses--not in spite of the patient's need for hope, but in hope's service.

PATHWAYS to improve end-of-life care--a community approach

Midwest Bioethics Center responded to the SUPPORT study with a strategic initiative called PATHWAYS to Improve End-of-Life Care: A Community Approach. This article introduces that initiative and reviews its substantial contributions in the broad sense. The effects of this program, although its evaluation has yet to be completed, are far-reaching because PATHWAYS tackled the problem of dying, not as a medical problem, but as a problem for the community as a whole.

Defects of insulin action and skeletal muscle glucose metabolism in growth hormone-deficient adults persist after 24 months of recombinant human growth hormone therapy

We have previously reported that GH-deficient (GHD) adults are severely insulin resistant. In the present study, we determined the effects of 6 months (n = 7) and 24 months (long-term; n = 11) of recombinant human GH (rhGH) therapy (approximately 0.22 IU/kg.week) on body composition and fasting biochemical (including lipid) parameters, and baseline and insulin-stimulated: 1) rates of hepatic glucose production, total glucose disposal (Rd), total glycolysis (GF) and glucose storage (GS); and 2) skeletal muscle glucose processing [using the euglycemic-hyperinsulinemic (approximately 60 mU/L) clamp technique with tritiated glucose infusion coupled with skeletal muscle biopsies]. To allow baseline comparison, these measurements were also obtained from 10 control subjects matched to the pretreated GHD adults for age, sex, and body mass index. Long-term rhGH therapy in GHD adults induced significant improvements in fat mass, abdominal fat mass and fat free mass, and reductions in fasting cholesterol and low-density lipoprotein-cholesterol levels (P < 0.05-0.01 vs. pretreatment values). However, there was a significant increase in fasting insulin (13.1 +/- 0.9 vs. 8.6 +/- 1.1 mU/L; P < 0.01) and connecting peptide (0.56 +/- 0.05 vs. 0.41 +/- 0.06 nmol/L; P < 0.05). Although rates of baseline hepatic glucose production, GF, and GS were unchanged, the insulin-stimulated increment (delta) in Rd, GF, and GS remained markedly attenuated in the long-term rhGH-treated GHD adults [pretreatment: delta Rd 16.6 +/- 3.4, delta GF 3.0 +/- 1.2, delta GS 13.6 +/- 3.0 vs. 24 months of rhGH: delta Rd 17.2 +/- 3.3, delta GF 3.1 +/- 0.9, delta GS 14.1 +/- 2.5 vs. controls: delta Rd 42.6 +/- 4.3, delta GF 9.2 +/- 1.9, delta GS 35.9 +/- 4.5 mumol/kg fat free mass.min; P < 0.05-0.01 vs. controls]. Additionally, there was a sustained reduction in the insulin-stimulated skeletal muscle glycogen synthase fractional velocity (pretreatment: 0.29 +/- 0.03 vs. 24 months of rhGH: 0.24 +/- 0.03 vs. controls: 0.48 +/- 0.04; both P < 0.05 vs. controls), which was accompanied by a sustained 44% decrease in baseline glycogen content and a 70% increase in baseline im glucose concentrations in the presence of low-to-normal glucose 6-phosphate levels and persisting euglycemia. Stepwise regression analysis revealed that body weight and fasting free fatty acid and high-density lipoprotein (HDL)-cholesterol accounted for 82% of the variance in the insulin sensitivity index in long-term rhGH-treated adults, and that the 24-month fasting insulin-like growth factor 1 was a negative predictor of the change in insulin sensitivity (r = -0.82; P < 0.01). In conclusion, despite improvements in body composition and lipid profiles, the severe defects of in vivo insulin sensitivity and skeletal muscle intracellular glucose phosphorylation and glycogen synthase activity, which are associated with modestly elevated insulin-like growth factor 1 levels, normal free fatty acid levels, and the development of hyperinsulinemia, persist with long-term rhGH therapy.

Peritoneal fluid analysis in peripartum mares

OBJECTIVE

To characterize, in mares, changes in peritoneal fluid that occurred within the first 7 days after routine foaling.

DESIGN

Prospective observational trial.

ANIMALS

15 mares.

PROCEDURE

Abdominocentesis was performed within 10 days before foaling and again 12 hours, 3 days, and 7 days after each horse foaled. Data recorded for each sample included total nucleated cell count, differential cell count, specific gravity, fibrinogen concentration, and total protein concentration. Smears of each sample were examined by a single clinical pathologist.

RESULTS

There were not any significant differences over time in specific gravity, total protein concentration, fibrinogen concentration, total nucleated cell count, or number of small mononuclear cells. Mean numbers of neutrophils and large mononuclear cells in samples collected after foaling were significantly higher than mean numbers in samples collected before foaling. For 11 of 14 horses, all samples were characterized cytologically as transudates without cytologic abnormalities.

CLINICAL IMPLICATIONS

Results of analysis of peritoneal fluid from peripartum mares suggest that nucleated cell count, protein concentration, and specific gravity of peritoneal fluid from mares that have recently foaled should be normal. Thus, peritoneal fluid abnormalities detected in mares within a week after foaling should usually be attributed to a systemic or gastrointestinal problem and not to the foaling process itself.

Insulin resistance in growth hormone-deficient adults: defects in glucose utilization and glycogen synthase activity

Fourteen GH-deficient (GHD) adults were compared with 12 age-, sex-, and body mass index-matched control subjects using a baseline tritiated glucose equilibration period and euglycemic-hyperinsulinemic (approximately 55 mU/L) clamp in conjunction with paired muscle biopsies for measurement of glycogen synthase fractional velocity (FV0.1). Despite similar basal rates of total glucose disposal (Rd), there was a 64% reduction in the insulin-stimulated rise (delta) in Rd in the GHD adults compared to that in controls [16.6 +/- 2.8 vs. 44.7 +/- 6.0 mumol/kg fat free mass (FFM)/min; P < 0.001], which was mainly due to a decreased glucose storage (GS) rate (delta GS, 12.6 +/- 2.9 vs. 39.5 +/- 7.5 mumol/kg FFM/min; P < 0.01). Furthermore, the insulin sensitivity indexes of Rd (0.39 +/- 0.07 vs. 0.85 +/- 0.11; P < 0.05) and GS (0.25 +/- 0.07 vs. 0.72 +/- 0.13 mumol/kg FFM/min per mU/L; P < 0.02) were reduced in GHD adults compared to the control values. The insulin sensitivity of the glycolytic pathway was also reduced by approximately 50% in GHD adults (P = 0.07 vs. controls). Insulin-stimulated FV0.1 was decreased in GHD adults (0.31 +/- 0.02 vs. 0.47 +/- 0.03; P < 0.005) despite similar basal FV0.1. Using multiple and stepwise regression analysis, duration of GH deficiency, fasting triglycerides and fasting insulin accounted for 67% of the variance in the insulin sensitivity index of Rd. In conclusion, the severe insulin resistance in GHD adults is mainly due to the inhibition of the GS pathway and glycogen synthase activity in peripheral tissues, which is related to the duration of GH deficiency, fasting triglycerides, and fasting insulin.

Multiple defects of both hepatic and peripheral intracellular glucose processing contribute to the hyperglycaemia of NIDDM

Non-insulin-dependent diabetic (NIDDM) patients were studied during a modified euglycaemic state when fasting hyperglycaemia was normalized by a prior (-210 to -150 min)--and later withdrawn (-150-0 min)--intravenous insulin infusion. Glucose metabolism was assessed in NIDDM patients (n = 10) and matched control subjects (n = 10) using tritiated glucose turnover rates, indirect calorimetry and skeletal muscle glycogen synthase activity determinations. Total and non-oxidative exogenous glycolytic flux rates were measured using appearance rates of tritiated water. A + 180 min euglycaemic hyperinsulinaemic (40 mU.m-2.min-1) clamp was performed to determine the insulin responsiveness of the various metabolic pathways. Plasma glucose concentration increased spontaneously during baseline measurements in the NIDDM patients (-120 to 0 min: 4.8 +/- 0.3 to 7.0 +/- 0.3 mmol/l; p < 0.01), and was primarily due to an elevated rate of hepatic glucose production (3.16 +/- 0.13 vs 2.51 +/- 0.16 mg.kg FFM-1.min-1; p < 0.01). In the NIDDM subjects baseline glucose oxidation was decreased (0.92 +/- 0.17 vs 1.33 +/- 0.14 mg.kg FFM-1.min-1; p < 0.01) in the presence of a normal rate of total exogenous glycolytic flux and skeletal muscle glycogen synthase activity. The simultaneous finding of an increased lipid oxidation rate (1.95 +/- 0.13 vs 1.61 +/- 0.07 mg.kg FFM-1.min-1; p = 0.05) and increased plasma lactate concentrations (0.86 +/- 0.05 vs 0.66 +/- 0.03 mmol/l; p = 0.01) are consistent with a role for both the glucose-fatty acid cycle and the Cori cycle in the maintenance and development of fasting hyperglycaemia in NIDDM during decompensation. Insulin resistance was demonstrated during the hyperinsulinaemic clamp in the NIDDM patients with a decrease in the major peripheral pathways of intracellular glucose metabolism (oxidation, storage and muscle glycogen synthase activity), but not in the pathway of non-oxidative glycolytic flux which was not completely suppressed during insulin infusion in the NIDDM patients (0.55 +/- 0.15 mg.kg FFM-1.min-1; p < 0.05 vs 0; control subjects: 0.17 +/- 0.29; NS vs 0). Thus, these data also indicate that the defect(s) of peripheral (skeletal muscle) glucose processing in NIDDM goes beyond the site of glucose transport across the cell membrane.

Implementation strategies for a do-not-resuscitate program in the prehospital setting

Implementation of a do-not-resuscitate (DNR) program in the prehospital setting in the greater Kansas City area using a standardized form created by a consortium of ethics committees began in January of 1989. This paper describes the strategies for implementation of the program.

Atypical appearance of lipomatous tumors on MR images: high signal intensity with fat-suppression STIR sequences

Lipomatous tumors generally have signal characteristics that allow them to be diagnosed with great accuracy by means of magnetic resonance imaging. These tumors usually have signal intensities similar to those of subcutaneous fat on both T1- and T2-weighted spin-echo images. Previous reports have not, to the authors' knowledge, described the appearance of lipomatous tumors on images obtained with a short-inversion-time inversion-recovery (STIR) sequence, which can be used to suppress signal from fat. Three lipomatous tumors (two liposarcomas and one lipoma) with signal characteristics unlike those of normal subcutaneous fat at all pulse sequences are presented.

Natural course of the human bite wound: incidence of infection and complications in 434 bites and 803 lacerations in the same group of patients

Human bites and common lacerations are frequent in certain residential groups in institutions for the care of developmentally disabled individuals. We screened the records of such an institution and studied the course and outcome of 434 human bite wounds and 803 lacerations in the same group of clients. Infection developed in 13.4% of the lacerations, and 17.7% of the bite wounds (chi 2 = 3.474; p greater than 0.06). Prophylactic antibiotics were administered after 14.0% of the bite wounds, and 3.2% of the lacerations. Infection supervened after prophylactic antibiotics in 29.5% of the bites and 34.6% of the lacerations. No patient with a bite wound required debridement, initial or subsequent surgical intervention other than wound closure, admission to hospital, or intravenous antibiotics. There is no recorded instance of a bite wound complication other than immediate loss of tissue. These data substantiate a higher incidence of infection in human bite wounds, but they are scant support for admonition that such wounds are indication for routine antimicrobial prophylaxis or aggressive surgical intervention.

Quantitative study of motor endplates in muscle fibres dissociated by a simple procedure

Large numbers of single muscle fibres can be obtained reproducibly from glutaraldehyde-fixed skeletal muscle by the method described here. With suitable modifications, one can estimate acetylcholine receptor number (alpha-bungarotoxin binding sites) and endplate area in parallel portions produced from the same muscle sample, so that small differences (e.g. with growth or between muscle types) become detectable. Microdissection further increases the precision of evaluation of junctional, perijunctional and extrajunctional binding sites. Other applications are illustrated.