Incidence of drug-drug interactions of QT-prolonging drugs in an onco-hematological outpatient

Background

Oral anticancer therapy is increasingly integrated into the care of patients (pts) with cancer. Recognition and management of pharmacodynamic drug-drug interactions is critical to provide efficacious and safe anticancer treatment.

Purpose

We aimed to gain insight into the real-world prevalence of potentially significant drug-drug interactions of QT-prolonging with oral antineoplastic agents used in an Oncohematological Hospital

Methods

We performed a prospective observational study in an oncohematological hospital between October 2020 and June 2021. Consecutive pts diagnosed with an oncohematological neoplasia and who were evaluated before start treatment with an oral anticancer drug or suport treatment (antibiotics, antivirals) were included. Cancer treatment data were obtained from our prescription software System. Demographic data and concomitant medication were obtained from our electronic medical record software. Micromedex was used to find potencial QT-prolonging interactions between anticancer drugs and chronic medication, and were classified as major or moderate.

Results

Oncohematological treatment was started in 1.217 pts during the study period. A total of 266 potential drug-drug interactions were detected in 171 patients (14.5%). A total of 46 drug-drug interactions of QT-prolonging (17.3%) were detected in 37 pts (21.6%), 22 men and 15 women, with a median age of 66.6 (range 40.9–87.3). Twenty-one (45.7%) and 25 (56.3%) drug interactions of QT-prolonging were classified as major and moderate, respectively, with a median interaction per pts 1.24 (1–3). The 3 most common cancers were: Renal carcinoma in 12 pts (32.4%), non-small cell lung carcinoma in 9 pts (24.7%) and prostate carcinoma in 4 pts (10.8%). The most commonly detected interacting drugs were sunitinib 12 pts (26.1%), osimertinib 10 pts (21.7%), and cabozantinib 5 pts (10.9%) among oncohematological drugs, and citalopram 8 (17.4%), quetiapine 6 (13%) and tramadol 5 (10.8%) among concomitant drugs.

Conclusion

Drug-drug interactions can play a significant role in drugs' cardiac safety in oncohematological pts, specially in renal, lung and prostate cancers, with more than one potential interacting drug or at least one major interaction. Cardiac monitorizacion should be considered when potential drug drug interaction is detected.

Funding Acknowledgement

Type of funding sources: None.

Attempts to use breeding approaches in Aedes aegypti to create lines with distinct and stable relative Wolbachia densities

Wolbachia is an insect endosymbiont being used for biological control in the mosquito Aedes aegypti because it causes cytoplasmic incompatibility (CI) and limits viral replication of dengue, chikungunya, and Zika viruses. While the genetic mechanism of pathogen blocking (PB) is not fully understood, the strength of both CI and PB are positively correlated with Wolbachia densities in the host. Wolbachia densities are determined by a combination of Wolbachia strain and insect genotype, as well as interactions with the environment. We employed both artificial selection and inbreeding with the goal of creating lines of Ae. aegypti with heritable and distinct Wolbachia densities so that we might better dissect the mechanism underlying PB. We were unable to shift the mean relative Wolbachia density in Ae. aegypti lines by either strategy, with relative densities instead tending to cycle over a narrow range. In lieu of this, we used Wolbachia densities in mosquito legs as predictors of relative densities in the remaining individual's carcass. Because we worked with outbred mosquitoes, our findings indicate either a lack of genetic variation in the mosquito for controlling relative density, natural selection against extreme densities, or a predominance of environmental factors affecting densities. Our study reveals that there are moderating forces acting on relative Wolbachia densities that may help to stabilize density phenotypes post field release. We also show a means to accurately bin vector carcasses into high and low categories for non-DNA omics-based studies of Wolbachia-mediated traits.

Acid pH Increases SARS-CoV-2 Infection and the Risk of Death by COVID-19

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can infect a broad range of human tissues by using the host receptor angiotensin-converting enzyme 2 (ACE2). Individuals with comorbidities associated with severe COVID-19 display higher levels of ACE2 in the lungs compared to those without comorbidities, and conditions such as cell stress, elevated glucose levels and hypoxia may also increase the expression of ACE2. Here, we showed that patients with Barrett's esophagus (BE) have a higher expression of ACE2 in BE tissues compared to normal squamous esophagus, and that the lower pH associated with BE may drive this increase in expression. Human primary monocytes cultured in reduced pH displayed increased ACE2 expression and higher viral load upon SARS-CoV-2 infection. We also showed in two independent cohorts of 1,357 COVID-19 patients that previous use of proton pump inhibitors is associated with 2- to 3-fold higher risk of death compared to those not using the drugs. Our work suggests that pH has a great influence on SARS-CoV-2 Infection and COVID-19 severity.

Kdm6b Regulates the Generation of Effector CD8+ T Cells by Inducing Chromatin Accessibility in Effector-Associated Genes

The transcriptional and epigenetic regulation of CD8⁺ T cell differentiation is critical for balancing pathogen eradication and long-term immunity by effector and memory CTLs, respectively. In this study, we demonstrate that the lysine demethylase 6b (Kdm6b) is essential for the proper generation and function of effector CD8⁺ T cells during acute infection and tumor eradication. We found that cells lacking Kdm6b (by either T cell-specific knockout mice or knockdown using short hairpin RNA strategies) show an enhanced generation of memory precursor and early effector cells upon acute viral infection in a cell-intrinsic manner. We also demonstrate that Kdm6b is indispensable for proper effector functions and tumor protection, and that memory CD8⁺ T cells lacking Kdm6b displayed a defective recall response. Mechanistically, we identified that Kdm6b, through induction of chromatin accessibility in key effector-associated gene loci, allows for the proper generation of effector CTLs. Our results pinpoint the essential function of Kdm6b in allowing chromatin accessibility in effector-associated genes, and identify Kdm6b as a potential target for therapeutics in diseases with dysregulated effector responses.

Kdm6b regulates the generation of effector CD8+ T cells by inducing chromatin accessibility in effector-associated genes

The transcriptional and epigenetic regulation of CD8+ T cell differentiation is critical for balancing pathogen eradication and long-term immunity by effector and memory CTLs respectively. Here, we demonstrate that the Lysine Demethylase 6b (Kdm6b) is essential for the proper generation and function of effector CD8+ T cells during acute infection and tumor eradication. We found that cells lacking Kdm6b (by either T cell-specific KO mice or knockdown utilizing shRNA strategies) show an enhanced generation of memory precursor and early effector cells upon acute viral infection in a cell-intrinsic manner. We also demonstrate that Kdm6b is indispensable for proper effector functions and tumor protection, and that memory CD8+ T cells lacking Kdm6b displayed a defective recall response. Mechanistically, we identified that Kdm6b, through induction of chromatin accessibility in key effector-associated gene loci, allows for the proper generation of effector CTLs. Our results pinpoint the essential function of Kdm6b in allowing chromatin accessibility in effector-associated genes, and identify Kdm6b as a potential target for therapeutics in diseases with dysregulated effector responses.

ACE2 Expression Is Increased in the Lungs of Patients With Comorbidities Associated With Severe COVID-19

Patients who died from COVID-19 often had comorbidities, such as hypertension, diabetes, and chronic obstructive lung disease. Although angiotensin-converting enzyme 2 (ACE2) is crucial for SARS-CoV2 to bind and enter host cells, no study has systematically assessed the ACE2 expression in the lungs of patients with these diseases. Here, we analyzed over 700 lung transcriptome samples of patients with comorbidities associated with severe COVID-19 and found that ACE2 was highly expressed in these patients, compared to control individuals. This finding suggests that patients with such comorbidities may have higher chances of developing severe COVID-19. Correlation and network analyses revealed many potential regulators of ACE2 in the human lung, including genes related to histone modifications, such as HAT1, HDAC2, and KDM5B. Our systems biology approach offers a possible explanation for increase of COVID-19 severity in patients with certain comorbidities.

1143 Wake-up Stroke In Hispanic Veterans: Clinical Characteristics

Introduction

Wake-up stroke (WUS) is a stroke that occurs during sleep and accounts for 14-29.6% of all acute ischemic stroke (AIS) cases. The use of intravenous alteplase, the therapeutic standard, requires identifying time of stroke onset. Recent studies suggest that obstructive sleep apnea (OSA) is an independent risk factor for WUS. This study aims to describe a population of Puerto Rican Veterans with WUS and to evaluate clinical differences between patients WUS and non-WUS (NWUS).

Methods

The study was a cross-sectional analysis of all patient records with AIS from April 2018 to July 2019. One hundred forty records were reviewed. Patients who woke up with new AIS symptoms were labeled as WUS. Study variables included demographics, comorbidities, medications, sleep disorders, prior stroke, administration of alteplase and the National Institute of Health Stroke Scale (NIHSS).

Results

Among 140 participants predominantly male (98.6%), 27.1% had WUS. The mean age was 75 (range 21-89). NIHSS mean was 5.9. Comorbidities for WUS vs NWUS were as follows: overweight or obese (60% vs 62.6% p=0.667), hypertension (100% vs 95.1% p=0.323), hyperlipidemia (95% vs 93% p=0.999), diabetes mellitus (55.3% vs 67% p=0.212), atrial fibrillation (26.3% vs 24.5% p=0.826), anxiety (36.8% vs 33.3% p=0.697), depression (55.3% vs 51.0% p=0.652), non-smokers (89.% vs 89%), smokers (10.5% vs 11.1%), and prior stroke (34.2% vs 35.3% p=0.905). Insomnia was observed in 42% vs 40% (p= 0.838) and 24% vs 23% (p=0.955) had OSA.

Conclusion

There were no significant differences in clinical characteristics between patients with WUS and NWUS in this sample of Puerto Rican Veterans. OSA was less prevalent than previously reported. Lack of recognition of OSA as a risk factor for stroke and under-diagnosis of OSA might explain the study results.

Support

 

ACE2 Expression is Increased in the Lungs of Patients with Comorbidities Associated with Severe COVID-19

The pandemic caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has resulted in several thousand deaths worldwide in just a few months. Patients who died from Coronavirus disease 2019 (COVID-19) often had comorbidities, such as hypertension, diabetes, and chronic obstructive lung disease. The angiotensin-converting enzyme 2 (ACE2) was identified as a crucial factor that facilitates SARS-CoV2 to bind and enter host cells. To date, no study has assessed the ACE2 expression in the lungs of patients with these diseases. Here, we analyzed over 700 lung transcriptome samples of patients with comorbidities associated with severe COVID-19 and found that ACE2 was highly expressed in these patients, compared to control individuals. This finding suggests that patients with such comorbidities may have higher chances of developing severe COVID-19. We also found other genes, such as RAB1A, that can be important for SARS-CoV-2 infection in the lung. Correlation and network analyses revealed many potential regulators of ACE2 in the human lung, including genes related to histone modifications, such as HAT1, HDAC2, and KDM5B. In fact, epigenetic marks found in ACE2 locus were compatible to with those promoted by KDM5B. Our systems biology approach offers a possible explanation for increase of COVID-19 severity in patients with certain comorbidities.

IRE1α-XBP1 signaling in leukocytes controls prostaglandin biosynthesis and pain

Inositol-requiring enzyme 1[α] (IRE1[α])-X-box binding protein spliced (XBP1) signaling maintains endoplasmic reticulum (ER) homeostasis while controlling immunometabolic processes. Yet, the physiological consequences of IRE1α-XBP1 activation in leukocytes remain unexplored. We found that induction of prostaglandin-endoperoxide synthase 2 (Ptgs2/Cox-2) and prostaglandin E synthase (Ptges/mPGES-1) was compromised in IRE1α-deficient myeloid cells undergoing ER stress or stimulated through pattern recognition receptors. Inducible biosynthesis of prostaglandins, including the pro-algesic mediator prostaglandin E2 (PGE₂), was decreased in myeloid cells that lack IRE1α or XBP1 but not other ER stress sensors. Functional XBP1 transactivated the human PTGS2 and PTGES genes to enable optimal PGE₂ production. Mice that lack IRE1α-XBP1 in leukocytes, or that were treated with IRE1α inhibitors, demonstrated reduced pain behaviors in PGE₂-dependent models of pain. Thus, IRE1α-XBP1 is a mediator of prostaglandin biosynthesis and a potential target to control pain.

Gene Expression and DNA Methylation Alterations in the Glycine N-Methyltransferase Gene in Diet-Induced Nonalcoholic Fatty Liver Disease-Associated Carcinogenesis

Nonalcoholic fatty liver disease (NAFLD) is becoming a major etiological risk factor for hepatocellular carcinoma (HCC) in the United States and other Western countries. In this study, we investigated the role of gene-specific promoter cytosine DNA methylation and gene expression alterations in the development of NAFLD-associated HCC in mice using (1) a diet-induced animal model of NAFLD, (2) a Stelic Animal Model of nonalcoholic steatohepatitis-derived HCC, and (3) a choline- and folate-deficient (CFD) diet (CFD model). We found that the development of NAFLD and its progression to HCC was characterized by down-regulation of glycine N-methyltransferase (Gnmt) and this was mediated by progressive Gnmt promoter cytosine DNA hypermethylation. Using a panel of genetically diverse inbred mice, we observed that Gnmt down-regulation was an early event in the pathogenesis of NAFLD and correlated with the extent of the NAFLD-like liver injury. Reduced GNMT expression was also found in human HCC tissue and liver cancer cell lines. In in vitro experiments, we demonstrated that one of the consequences of GNMT inhibition was an increase in genome methylation facilitated by an elevated level of S-adenosyl-L-methionine. Overall, our findings suggest that reduced Gnmt expression caused by promoter hypermethylation is one of the key molecular events in the development of NAFLD-derived HCC and that assessing Gnmt methylation level may be useful for disease stratification.

Contrasting thermal strategies of montane Neotropical bats at high elevations

In the Neotropics, captive vespertilionid bats substantially reduce their metabolic rate at low ambient temperatures, similar to their temperate counterparts, whereas the ability of phyllostomids to lower metabolic rate seems to be more limited, even in mountain species. Nevertheless, field data on the thermal behaviour of syntopic individuals from these two families is lacking. Consequently, we aimed to test whether torpor was more common and deeper in vesper bats compared to leaf-nosed bats by studying skin temperature (Tsk) variation in individuals experiencing the same environmental conditions at a mountain area. Bats experienced ambient temperatures below 15 °C. Average Tsk was 10 °C in Myotis oxyotus gardneri (Vespertilionidae) during the day, while Sturnira burtonlimi (Phyllostomidae) regulated diurnal Tsk above 30 °C. Constant food availability may explain why diurnal Sturnira burtonlimi pay the high energetic cost required to remain normothermic and to defend a wide Ta-Tsk gap but further studies are needed to elucidate additional strategies that may be employed by these bats to reduce the energetic demands of normothermy. Our study shows that the contrasting thermal strategies and torpor use adopted by vespertilionid insectivores and phyllostomid frugivores in captive settings also occur in free-ranging conditions, thus providing a basis to develop further studies with predictions more accurately rooted in field data.

Epigenetically mediated inhibition of S-adenosylhomocysteine hydrolase and the associated dysregulation of 1-carbon metabolism in nonalcoholic steatohepatitis and hepatocellular carcinoma

The substantial rise in the prevalence of nonalcoholic steatohepatitis (NASH), an advanced form of nonalcoholic fatty liver disease, and the strong association between NASH and the development of hepatocellular carcinoma indicate the urgent need for a better understanding of the underlying mechanisms. In the present study, by using the Stelic animal model of NASH and NASH-derived liver carcinogenesis, we investigated the role of the folate-dependent 1-carbon metabolism in the pathogenesis of NASH. We demonstrated that advanced NASH and NASH-related liver carcinogenesis are characterized by a significant dysregulation of 1-carbon homeostasis, with diminished expression of key 1-carbon metabolism genes, especially a marked inhibition of the S-adenosylhomocysteine hydrolase ( Ahcy) gene and an increased level of S-adenosyl-l-homocysteine (SAH). The reduction in Ahcy expression was associated with gene-specific cytosine DNA hypermethylation and enrichment of the gene promoter by trimethylated histone H3 lysine 27 and deacetylated histone H4 lysine 16, 2 main transcription-inhibiting markers. These results indicate that epigenetically mediated inhibition of Ahcy expression may be a driving force in causing SAH elevation and subsequent downstream disturbances in transsulfuration and transmethylation pathways during the development and progression of NASH.-Pogribny, I. P., Dreval, K., Kindrat, I., Melnyk, S., Jimenez, L., de Conti, A., Tryndyak, V., Pogribna, M., Ortega, J. F., James, S. J., Rusyn, I., Beland, F. A. Epigenetically mediated inhibition of S-adenosylhomocysteine hydrolase and the associated dysregulation of 1-carbon metabolism in nonalcoholic steatohepatitis and hepatocellular carcinoma.

Abstract A01: Development and application of DNA Repair Dysregulation Score in predicting response to neoadjuvant therapy in patients with rectal cancer

Purpose/Background: Neoadjuvant chemoradiation (nCRT) may lead to complete tumor regression in a proportion of patients and may offer the opportunity for organ-preserving strategies. Pretreatment prediction of tumor response to nCRT would allow identification of ideal candidates for this alternative treatment, avoiding the unnecessary detrimental effects of radiation for patients unlikely to develop complete response (CR). Dysregulation of DNA repair pathways is involved in several carcinogenetic processes of human cancers, including colorectal malignancies. The purpose of this study was to develop and test the performance of DNA Repair Dysregulation Score (DS) in the prediction of tumor response to neoadjuvant CRT by comparing gene expression profiles of patients with CR and incomplete response (IR) to nCRT.

Methods/Interventions: 46 patients with T2-3N0-1M0 distal rectal cancer underwent pretreatment biopsy collection prior to nCRT. All patients underwent radiation and 5FU-based chemotherapy. Patients were divided in two groups: a training group composed of 25 patients (9 patients with CR and 16 patients with IR) and a validation group composed of 21 patients (8 patients CR and 13 patients with IR). We performed global gene expression analysis using RNA-seq in the training group to search for differentially expressed genes according to tumor response. To develop the DS, RNA-seq expression values in RPKM of upregulated genes among CR patients were multiplied by +1. Expression values for downregulated genes among IR patients were multiplied by -1. The sum of all expression values for all genes was used to determine individual DS for each patient. Average DS values between CR and IR were compared using Mann-Whitney test and ROC curve was used to estimate the predictive value of the score. To assess the predictive value of our DS, in an independent set of patients, we used qRT-PCR to evaluate gene expression of dysregulated DNA repair genes. Relative expression for dysregulated genes was calculated by ∆∆Ct method. Expression values for upregulated genes among CR patients were multiplied by +1 and expression values for downregulated genes among IR patients were multiplied by -1. The sum of all relative expression values for all genes was performed to determine individual score. Average DS values between CR and IR in this independent group were also compared using Mann-Whitney test and ROC curve was used to estimate the predictive value of the score.

Results/Outcome: Using RNA-seq we identified 7 differentially expressed genes between CR and IR patients to develop the DS (XPA, XRCC3, ATRIP, UBE2A, NEIL2, XRCC4). The average DS value in the training group was 27 RPKM for CR and 14 for IR (p<0.001). The ROC curve resulted in an AUC of 0.94 with high sensitivity (87%) and specificity (100%) to predict response to nCRT using a cutoff of >19.5 for the prediction of response. The average DS score in the validation set was 11.5 for CR and 9.2 for IR (p<0.006). The ROC curve resulted in an AUC 0.85 with high sensitivity (62.5%) and specificity (92.3%) to predict response using a cutoff of >10.7 for the prediction or response.

Conclusions: Our DS may provide accurate prediction of tumor response to nCRT and may be useful in clinical practice to optimized nCRT stratification and adopt organ-preserving strategies for selected patients.

Citation Format: Leandro Jimenez, Fernanda Koyama, Jennifer DeVecchio, Mathew Kalady, Angelita Habr-Gama, Rodrigo Perez, Anamaria Camargo. Development and application of DNA Repair Dysregulation Score in predicting response to neoadjuvant therapy in patients with rectal cancer [abstract]. In: Proceedings of the AACR International Conference held in cooperation with the Latin American Cooperative Oncology Group (LACOG) on Translational Cancer Medicine; May 4-6, 2017; São Paulo, Brazil. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(1_Suppl):Abstract nr A01.

Comprehensive cancer-gene panels can be used to estimate mutational load and predict clinical benefit to PD-1 blockade in clinical practice

Cancer gene panels (CGPs) are already used in clinical practice to match tumor's genetic profile with available targeted therapies. We aimed to determine if CGPs could also be applied to estimate tumor mutational load and predict clinical benefit to PD-1 and CTLA-4 checkpoint blockade therapy. Whole-exome sequencing (WES) mutation data obtained from melanoma and non-small cell lung cancer (NSCLC) patients published by Snyder et al. 2014 and Rizvi et al. 2015, respectively, were used to select nonsynonymous somatic mutations occurring in genes included in the Foundation Medicine Panel (FM-CGP) and in our own Institutional Panel (HSL-CGP). CGP-mutational load was calculated for each patient using both panels and was associated with clinical outcomes as defined and reported in the original articles. Higher CGP-mutational load was observed in NSCLC patients presenting durable clinical benefit (DCB) to PD-1 blockade (FM-CGP P=0.03, HSL-CGP P=0.01). We also observed that 69% of patients with high CGP-mutational load experienced DCB to PD-1 blockade, as compared to 20% of patients with low CGP-mutational load (FM-CGP and HSL-CGP P=0.01). Noteworthy, predictive accuracy of CGP-mutational load for DCB was not statistically different from that estimated by WES sequencing (P=0.73). Moreover, a high CGP-mutational load was significantly associated with progression-free survival (PFS) in patients treated with PD-1 blockade (FM-CGP P=0.005, HR 0.27, 95% IC 0.105 to 0.669; HSL-CGP P=0.008, HR 0.29, 95% IC 0.116 to 0.719). Similar associations between CGP-mutational load and clinical benefit to CTLA-4 blockade were not observed. In summary, our data reveals that CGPs can be used to estimate mutational load and to predict clinical benefit to PD-1 blockade, with similar accuracy to that reported using WES.

Equivalence of afternoon spot and 24-h urinary hydration biomarkers in free-living healthy adults

Background/Objectives:

Urinary biomarkers of hydration (urine osmolality, U_Osm; urine specific gravity, U_SG) follow circadian variations. For individuals, researchers and health-care professionals, there is value in identifying time frames during which spot values of U_Osm and U_SG are representative of 24-h values in healthy young adults.

Subjects/Methods:

Eighty-two free-living adults (22.3±2.9 years, 22.2±1.5 kg/m²) collected individual urine voids over a 24-h period. U_Osm and U_SG were measured on each void and on the pooled 24-h sample. To determine the time of day when a spot sample was likely to be equivalent to the 24-h value, daytime voids were binned by time and equivalence was tested for each 2-h window. Equivalence was a priori defined as being within 100 mOsm/kg (U_Osm) and within 0.003 units (U_SG) of 24-h values.

Results:

For both U_Osm and U_SG, voids between 1400 and 2000 hours produced values that were equivalent to the 24-h sample, whereas earlier voids tended to overestimate 24-h U_Osm and U_SG. For windows 1401–1600 hours, 1601–1800 hours and 1801–2000 hours, the mean difference (95% confidence interval) between spot and 24-h U_Osm (mOsm/kg) was −25 (−72; 22), 28 (−35; 92) and 12 (−41; 66), respectively, whereas for U_SG the difference was 0.0014 (−0.0028; −0.0001), 0.0001 (−0.0017; 0.0019) and 0.0005 (−0.0018; 0.0009), respectively.

Conclusions:

In free-living healthy French adults, 24-h urine concentration can be approximated from a mid- to late-afternoon spot urine sample. This finding suggests that an afternoon sample may be an accurate and practical tool for hydration monitoring, useful to individuals and health-care practitioners.

Factors influencing mortality in neutropenic patients with haematologic malignancies or solid tumours with bloodstream infection

The purpose of this study was to identify factors influencing mortality in neutropenic patients with haematologic malignancies or solid tumours with bloodstream infection (BSI). All episodes of BSI occurring in adult neutropenic patients with haematologic malignancies or solid tumours were prospectively recorded from January 2006 to December 2013. We analysed the factors influencing mortality in both groups of patients. We documented 602 consecutive episodes of BSI; 510 occurred in patients with haematologic malignancies and 92 in patients with solid tumours. The overall case-fatality rates were 12% and 36%, respectively. Independent risk factors associated with a higher case-fatality rate in patients with haematologic malignancies were: intensive care unit admission (odds ratio (OR), 15.2; 95% confidence interval (CI), 5.4-42.7), advanced neoplasm (OR, 8.7; 95% CI, 2.9-25.7), corticosteroid therapy (OR, 7.0; 95% CI, 3-16.4), multidrug-resistant Gram-negative BSI (OR, 3.8; 95% CI, 1.2-11.8) and a Multinational Association for Supportive Care in Cancer risk score of <21 (OR, 3.1; 95% CI, 1.3-7.4). By contrast, coagulase-negative staphylococci BSI (OR, 0.04; 95% CI, 0.004-0.5) and empirical antibiotic combination therapy (OR, 0.1; 95% CI, 0.05-0.3) were found to be protective. Independent risk factors for overall case-fatality rate in patients with solid tumours were: shock at presentation (OR, 14.3; 95% CI, 3.2-63.8), corticosteroid therapy (OR, 10; 95% CI, 2.3-44) and advanced neoplasm (OR, 7.8; 95% CI, 1.4-41.4). Prognostic factors identified in this study may help to detect those patients at higher risk of death in each group. Medical intervention addressing some of these factors might improve the outcome of BSI in neutropenic patients with haematologic malignancies or solid tumours.

{Beta}2-adrenergic receptor agonists inhibit the proliferation of 1321N1 astrocytoma cells

Astrocytomas and glioblastomas have been particularly difficult to treat and refractory to chemotherapy. However, significant evidence has been presented that demonstrates a decrease in astrocytoma cell proliferation subsequent to an increase in cAMP levels. The 1321N1 astrocytoma cell line, as well as other astrocytomas and glioblastomas, expresses β(2)-adrenergic receptors (β(2)-ARs) that are coupled to G(s) activation and consequent cAMP production. Experiments were conducted to determine whether the β(2)-AR agonist (R,R')-fenoterol and other β(2)-AR agonists could attenuate mitogenesis and, if so, by what mechanism. Receptor binding studies were conducted to characterize β(2)-AR found in 1321N1 and U118 cell membranes. In addition, cells were incubated with (R,R')-fenoterol and analogs to determine their ability to stimulate intracellular cAMP accumulation and inhibit [(3)H]thymidine incorporation into the cells. 1321N1 cells contain significant levels of β(2)-AR as determined by receptor binding. (R,R')-fenoterol and other β(2)-AR agonists, as well as forskolin, stimulated cAMP accumulation in a dose-dependent manner. Accumulation of cAMP induced a decrease in [(3)H]thymidine incorporation. There was a correlation between concentration required to stimulate cAMP accumulation and inhibit [(3)H]thymidine incorporation. U118 cells have a reduced number of β(2)-ARs and a concomitant reduction in the ability of β(2)-AR agonists to inhibit cell proliferation. These studies demonstrate the efficacy of β(2)-AR agonists for inhibition of growth of the astrocytoma cell lines. Because a significant portion of brain tumors contain β(2)-ARs to a greater extent than whole brain, (R,R')-fenoterol, or some analog, may be useful in the treatment of brain tumors after biopsy to determine β(2)-AR expression.

Bone marrow cells can give rise to ameloblast-like cells

Post-eruptive loss of ameloblasts requires identification of alternative sources for these cells to realize tooth-tissue-engineering strategies. Recent reports showed that bone-marrow-derived cells can give rise to different types of epithelial cells, suggesting their potential to serve as a source for ameloblasts. To investigate this potential, we mixed c-Kit(+)-enriched bone marrow cells with embryonic dental epithelial cells and cultured them in re-association with dental mesenchyme. Non-dividing, polarized, and secretory ameloblast-like cells were achieved without cell fusion. Before basement membrane reconstitution, some bone marrow cells migrated to the mesenchyme, where they exhibited morphological, molecular, and functional characteristics of odontoblasts. These results show, for the first time, that bone-marrow-derived cells can be reprogrammed to give rise to ameloblast-like cells, offering novel possibilities for tooth-tissue engineering and the study of the simultaneous differentiation of one bone marrow cell subpopulation into cells of two different embryonic lineages.

In vitro detection of differential and cell-specific hepatobiliary toxicity induced by geldanamycin and 17-allylaminogeldanamycin in rats

The differential toxicity of two anticancer agents is described using the in vitro rat liver slice culture model. Liver slices from F-344 rats were cultured for 5 days in Waymouth's-based medium with exposure to a range of geldanamycin (GEL) or 17-allylaminogeldanamycin (17-AAG) concentrations. GEL induced concentration-dependent reduction of alkaline phosphatase and of gamma-glutamyl transferase levels, which are indicators of biliary epithelial cell(s) (BEC) viability, and exhibited hepatocellular toxicity at higher concentrations. Histologically, BEC cell injury was evident at the lowest GEL concentration (0.1 microM) and progressed to overt bile duct necrosis at 5 microM, a level at which hepatocellular damage was also more prominent. Slices exposed to the same concentrations were more sensitive to toxic effects of GEL than of 17-AAG. 17-AAG at the lowest concentration had more slice biomarker retention than GEL, and histological analysis revealed minimal toxic effect on BEC. With increasing concentration, BEC were progressively lost, and BEC proliferation was completely inhibited at 5 microM 17-AAG. Hepatocellular injury was evident only at high dose exposures. This is believed to be the first use of an in vitro liver tissue model to accurately predict the differential and concentration-dependent toxicities of these compounds.

Contribution of NTRK2 to the genetic susceptibility to anorexia nervosa, harm avoidance and minimum body mass index

Anorexia nervosa (AN) and bulimia nervosa (BN) are eating disorders (ED) with complex genetic and environmental components. Genetic studies and animal models support the participation of brain-derived neurotrophic factor (BDNF) in the vulnerability to AN and BN. We investigated the genetic contribution of the BDNF-specific receptor neurotrophic tyrosine kinase receptor type 2 (NTRK2) to the susceptibility to ED. We have screened the entire NTRK2 gene in 91 patients with ED and have identified 14 single-nucleotide polymorphisms (SNPs). A population-based association study with six SNPs from the NTRK2 locus was performed in 164 ED patients and 121 controls. Significant evidence of association for markers -69C>G and IVS13+40G>A was detected. We also observed a strong association between the C-A-insC haplotype (-69/IVS13+40/2784-2785) and binge-eating/purging AN (ANP, P=0.006; OR=2.27), and a reduced frequency of haplotype G-A-delCl in BN patients (P=0.034; OR=0.6). The analysis of ED-related phenotypes revealed a clear association between NTRK2, high scores of Harm avoidance measured by the temperament and character inventory (TCI-R; P=0.003) and minimum body mass index (minBMI; P<0.001). Our data support a contribution of NTRK2 to the genetic susceptibility of ED, mainly ANP, and ED-related phenotypic traits, such as Harm avoidance and minBMI.

PCR detection of Salmonella typhimurium in pharmaceutical raw materials and products contaminated with a mixed bacterial culture using the BAX system

The BAX system, a PCR-based assay, was evaluated for detecting Salmonella typhimurium in pharmaceutical raw materials and products contaminated with mixed bacterial cultures of Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Salmonella typhimurium. Artificially contaminated samples were preenriched in lactose broth with and without Tween 20. After preenrichment, samples were analyzed by PCR and standard methods. Ten of 25 samples did not show presence of the specific Salmonella spp. 740-base pair DNA fragment. However, S. typhimurium was isolated and identified by standard methods from all 25 samples. To optimize S. typhimurium detection in PCR negative samples, lactose broth was replaced by buffered peptone water (BPW) as the preenrichment broth. When BPW was used, all 10 samples were PCR positive. BPW enrichments increased S. typhimurium growth resulting in rapid PCR detection. The presence of non-Salmonella bacteria influenced the performance of the PCR-based assay. Optimization of S. typhimurium PCR detection in mixed culture required the use of different preenrichment broths. However, the BAX system detected S. typhimurium within 27 hours while standard methods required 5-7 days.

Rapid methods for the microbiological surveillance of pharmaceuticals

The use of rapid microbiological methods in pharmaceutical laboratories has improved the quality control analysis of water, products, raw materials, and enhanced the antimicrobial effectiveness testing of pharmaceutical finished products. Rapid release of samples has resulted in the optimization of manufacturing, product testing, and release allowing high throughput and simultaneous analysis of pharmaceutical formulations. ATP Bioluminescence, Impedance, Direct Viable Counts, and Flow Cytometry determine the total microbial content in a given pharmaceutical sample while PCR and Immunoassays detect the presence or absence of specific microbial species. Rapid methods provide reliable and cost effective analysis for the microbiological evaluation of pharmaceutical environments. The dramatic reduction in detection times and analysis, e.g., from 30 hours to 90 minutes, by using rapid methods will ultimately lead the pharmaceutical industry closer to real time monitoring of processes and samples.

Molecular diagnosis of microbial contamination in cosmetic and pharmaceutical products: a review

Molecular methodologies such as adenosine triphosphate (ATP) bioluminescence and polymerase chain reaction (PCR)-based assays provide rapid quality control analysis of cosmetic and pharmaceutical finished products and raw materials. Using a single enrichment broth for bacteria, yeast, and mold, ATP bioluminescence detected microbial contamination within 27 h. Samples were automatically lysed to release microbial ATP and light production was quantitated using the Celsis Optocomp. However, to maintain the detection time to within 27 h, different enrichment broths were required for neutralization of antimicrobial ingredients in finished products and to provide specific nutrients for growth optimization. To perform the PCR reaction, bacterial DNA was extracted using a Tris-EDTA-Tween 20-proteinase K buffer at 35 degrees C while yeast and mold DNA were extracted using a Tris-EDTA-SDS buffer at 95 degrees C. Extracted microbial DNA was added to Ready-To-Go PCR beads and specific DNA primers. The primers were targeted to amplify specific regions within Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhimurium, Burkholderia cepacia, Candida albicans, and Aspergillus niger. Furthermore, conserved bacterial ribosomal DNA sequences have also been used for sterility testing of samples. The results from these studies indicate that both ATP bioluminescence and PCR assays provide rapid, reliable, and cost effective methods for quality evaluation. This will ultimately result in faster product release and production optimization.

Exercise does not induce oxidative stress in trained heart transplant recipients

PURPOSE

The objectives of this study were twofold: 1) to determine the effect of incremental exercise to volitional fatigue on plasma levels of lipid peroxidation (malondialdehyde) in heart transplant recipients (HRT) and 2) to examine blood antioxidant capacity in HTR by assessment of antioxidant enzyme activities and vitamin E levels.

METHODS

Seven endurance-trained HTR (mean +/- SD; age 39.7 +/- 12.8 yr) and seven endurance-trained healthy, age-matched control subjects (HC) (mean age 40.6 +/- 10.7 yr) performed a symptom-limited incremental exercise test on a cycle ergometer. Venous blood samples were obtained at rest, exercise, and during recovery and analyzed for plasma levels of malondialdehyde (MDA) as well as markers of blood antioxidant capacity. After exercise and during recovery, all dependent measures were corrected for plasma volume changes induced by exercise. Significance was established at (P < 0.05).

RESULTS

No group differences existed in plasma levels of MDA at rest. Further, graded exercise did not alter plasma levels of MDA in either group. Resting erythrocyte glutathione peroxidase (GPX) activity was significantly lower and erythrocyte superoxide dismutase (SOD) activity was higher in HTR compared with HC. Finally, at rest, no group differences existed in plasma GPX activity or vitamin E levels.

CONCLUSIONS

Graded exercise to fatigue does not promote an increase in oxidative stress in blood of exercise trained HTR. Therefore, physical exercise does not appear to pose an oxidative-stress risk for these patients.

Use of PCR analysis for detecting low levels of bacteria and mold contamination in pharmaceutical samples

PCR assays were developed and compared to standard methods for quality evaluation of pharmaceutical raw materials and finished products with low levels of microbial contamination. Samples were artificially contaminated with less than 10 CFU of Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Aspergillus niger. Bacterial DNA was extracted from each enrichment broth by mild lysis in Tris-EDTA-Tween 20 buffer containing proteinase K while mold DNA was extracted by boiling samples in Tris-EDTA-SDS buffer for 1 h. A 10-microl aliquot of extracted DNA was added to Ready-To-Go PCR beads and specific primers for E. coli, S. aureus, and P. aeruginosa. However, 50-microl aliquots of extracted mold DNA were used for amplification of specific A. niger DNA sequences. Standard methods required 6-8 days while PCR detection of all microorganisms was completed within 27 h. Low levels of microbial contamination were detected in all raw materials and products using PCR assays. Rapid quality evaluation of pharmaceutical samples resulted in optimization of product manufacturing, quality control, and release of finished products.

Molecular detection of Burkholderia cepacia in toiletry, cosmetic, and pharmaceutical raw materials and finished products

A polymerase chain reaction (PCR) assay was developed and compared with standard methods for rapid detection of Burkholderia cepacia, a major industrial contaminant, in cosmetic and pharmaceutical raw materials and finished products. Artificially contaminated samples were incubated for 24 h in trypticase soy broth containing 4% Tween 20 and 0.5% soy lecithin. DNA was extracted from each sample using a proteinase K-tris-EDTA-Tween 20 treatment at 35 degrees C. The extracted DNA was added to Ready-To-Go PCR beads and specific DNA primers for B. cepacia. The B. cepacia DNA primers coded for a 209-base pair (bp) fragment of the 16S rRNA ribosomal gene. No DNA amplification was observed in samples that were not spiked with B. cepacia. However, all contaminated samples showed the specific 209-bp fragment for B. cepacia. There was a 100% correlation between standard methods and the PCR assay. Standard microbiological methods required 5-6 days for isolation and identification of spiked microorganisms, whereas PCR detection and identification was completed in 27 h. PCR detection of B. cepacia allows for rapid quality evaluation of cosmetic and pharmaceutical raw materials and finished products.